Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/26/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
925 PM MST SAT NOV 23 2013
.SYNOPSIS...LOW PRESSURE OVER SOUTHEASTERN CALIFORNIA AND SOUTHWEST
ARIZONA THIS EVENING WILL MOVE NORTHEAST ACROSS ARIZONA TONIGHT INTO
SUNDAY. THIS SYSTEM WILL CONTINUE TO BRING PERIODS OF VALLEY RAIN
AND MOUNTAIN SNOW THROUGH TONIGHT. RAIN AND MOUNTAIN SNOW WILL
DECREASE FROM WEST TO EAST SUNDAY FOLLOWED BY A FEW LINGERING SNOW
SHOWERS ACROSS THE WHITE MOUNTAINS MONDAY. DRY CONDITIONS WILL THEN
PREVAIL MONDAY NIGHT THROUGH FRIDAY. A GRADUAL WARMING TREND
EXPECTED DURING THE UPCOMING WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY SHOWS THE UPPER LOW SPINNING
ACROSS EXTREME SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. RADAR
MOSAIC SHOWS ISOLATED SHOWERS OCCURRING OVER MAINLY CENTRAL AND
EASTERN PORTIONS OF THE FORECAST AREA AT THIS TIME. HRRR MODEL SHOWS
GENERALLY ISOLATED TO LOW END SCATTERED ACTIVITY...BUT REDEVELOPMENT
OCCURS AFTER MIDNIGHT OVER THE EASTERN ZONES THROUGH THE EARLY
MORNING HOURS. THAT SAID...THE WINTER STORM WARNING AND ADVISORIES
FOR THE REMAINDER OF THE NIGHT AND INTO EARLY SUNDAY CONTINUE TO
LOOK GOOD. DAY SHIFT MAY BE ABLE TO CANCEL THESE PRODUCTS EARLIER IF
THE SHOWERS EXIT AS EARLY AS THE HRRR IS INDICATING.
LOW TEMPERATURES EXPECTED TO DROP INTO THE MID 30S TO MID 40S ACROSS
SOME OF THE CENTRAL DESERTS AND EASTERN VALLEYS. WITH CURRENT
DEWPOINT READINGS IN THE MID 30S TO MID 40S WE COULD SEE SOME FOG...
ESPECIALLY FOR AREAS EAST OF TUCSON TOWARD VAIL AND THEN TO THE
SOUTH TOWARD SONOITA...SIMILAR TO WHAT OCCURRED YESTERDAY EVENING AT
ABOUT THIS TIME. THIS IS AN AREA THAT RECEIVED SIGNIFICANT RAINS IN
THE PAST COUPLE OF DAYS...AND WITH COOLER AIR ADVECTING IN FROM THE
EAST SOME FOG MAY DEVELOP ONCE AGAIN. WILL ADD A MENTION OF PATCHY
FOG IN THE FORECAST FOR THE REMAINDER OF TONIGHT.
AS OF 04Z (9 PM MST)...TEMPERATURES RANGED FROM THE LOWER 40S TO THE
MID 50S AND THESE READINGS ARE MOSTLY ON TRACK WITH EXPECTED
OVERNIGHT LOW TEMPERATURES...SO NO CHANGES ARE PLANNED...BUT WILL
CONTINUE TO MONITOR.
DETAILS REGARDING THE FORECAST BEYOND TONIGHT ARE BELOW IN THE
PREVIOUS DISCUSSION SECTION.
&&
.AVIATION...EAST OF KTUS-KOLS LINE...WIDESPREAD RAIN AND HIGHER
ELEVATION SNOW WILL SHIFT EAST ACROSS SE AZ THROUGH TONIGHT INTO
SUNDAY MORNING WITH WIDESPREAD MVFR CIGS/VSBYS/MT OBSCURATIONS AND
OCCASIONAL IFR CIGS/VSBYS FORECAST. WEST OF KTUS-KOLS...A FEW RAIN
AND HIGH ELEVATION SNOW SHOWERS WILL LINGER THROUGH TONIGHT. IFR
VSBYS IN FOG AND MT OBSCURATIONS PSBL WEST OF THIS LINE OVERNIGHT.
SURFACE WINDS WILL GENERALLY BE ELY/SELY 8-15 KTS WITH GUSTS TO 20
KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...LOW PRESSURE WILL MOVE NORTHEAST ACROSS AZ THE
REMAINDER OF THE WEEKEND. OVER SE AZ...RAIN AND MOUNTAIN SNOW WILL
SHIFT EAST TONIGHT AND END SUNDAY NIGHT IN THE WHITE MOUNTAINS.
DRY CONDITIONS WILL PREVAIL DURING THE COMING WORK WEEK WITH COOLER
THAN AVERAGE TEMPERATURES RETURNING TO NEAR NORMAL BY THANKSGIVING.
WINDS ARE NOT EXPECTED TO BE OVERLY STRONG THROUGH THE PERIOD
ALTHOUGH EASTERLY WINDS COULD GET GUSTY TUESDAY NIGHT INTO EARLY
WEDNESDAY THROUGH MOUNTAIN GAPS AND PASSES.
&&
.CLIMATE...TODAYS RAINFALL AT THE TUCSON INTERNATIONAL AIRPORT AS OF
2 PM STOOD AT 1.22" WHICH BRINGS THE 3 DAY STORM TOTAL TO 2.11". THE
2.11" RANKS AS THE 3RD WETTEST NOVEMBER THREE DAY RAIN EVENT IN
TUCSON. THE TOP TWO ARE 2.83" IN 1895 AND 2.39" IN 1900. THE MONTH
TOTAL OF 2.23" RANKS AS THE 7TH WETTEST NOVEMBER ON RECORD. TODAYS
TOTAL OF 1.22" RANKS AS THE 8TH WETTEST NOVEMBER DAY ON RECORD.
&&
.PREVIOUS DISCUSSION...AS THE LOW MOVES THROUGH THE STATE ON
SUNDAY...IT WILL SLOWLY FILL BUT STILL PLENTY OF MOISTURE AROUND
ALONG WITH COLD POOL ALOFT TO KEEP SCATTERED SHOWERS IN THE
FORECAST. SYSTEM EAST OF THE AREA ON MONDAY WITH MUCH COLDER
OVERNIGHT LOWS TUESDAY INTO WEDNESDAY. ADDING FROST TO THE FORECAST
FOR PORTIONS OF THE EASTERN ZONES.
WARMING TREND STARTING MONDAY AND CONTINUING INTO TURKEY DAY WHERE
HIGHS WILL BE AT OR SLIGHTLY ABOVE NORMAL. MODELS HINTING AS ANOTHER
PACIFIC STORM HEADED FOR THE DESERT SW NEXT SUNDAY WHICH IS JUST
OUTSIDE OF OUR 7 DAY FORECAST. SOMETHING TO WATCH THOUGH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM MST SUNDAY FOR AZZ510-511.
WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR AZZ512-514.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
242 PM MST SUN NOV 24 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
...SNOW WINDING DOWN ON MONDAY...
UPPER LOW IS NOW NOW MOVING EASTWARD ALONG THE CO NM BORDER. COLDER CLOUD
TOPS HAVE SHIFTED TO THE NE PORTION OF CO...WHERE SEVERAL BANDS OF
SNOW ARE ROTATING NORTHWESTWARD ALONG THE NRN I-25 CORRIDOR. THE LOW HAS
DEFINITELY TAKEN A MORE NRN TRACK AS THE NAM AND ESPECIALLY THE
ECMWF HAD FORECAST IT TO DO. HOWEVER...NOT A LOT OF MOISTURE LEFT
WITH THE SYSTEM...AND ACCUMS TONIGHT INTO MON MORNING PROBABLY WILL
NOT BE ALL THAT IMPRESSIVE. MAIN FOCUS FOR HEAVIER ACCUMS WILL BE
DUE TO N-NE WINDS INCREASING TONIGHT AS THE LOW CONTINUES TO MOVE
AWAY. LATEST RUC SHOWING H7 WINDS INCREASING TO 30-40 KTS AFTER
ABOUT 04Z TONIGHT. THIS WILL LEAD TO SOME DECENT OROGRAPHIC ACCUMS
OVER THE HIGHER ELEVATIONS OF THE ERN MT RANGES OVERNIGHT...AND
FAVORED SPOTS LIKE CUCHARA COULD SEE SOME RESPECTABLE SNOWFALL.
LATEST HI RES MODELS REALLY SHOWING THIS POTENTIAL OVER THE WETS AND
NRN SANGRES...SO WILL ADD THE WETS TO THE CURRENT SUITE OF
ADVISORIES WE HAVE OUT THROUGH 12Z MONDAY. ELSEWHERE...BEST BET OF
SNOW OVER THE PLAINS WILL BE ALONG AND WEST OF I-25...AND ESPECIALLY
SOUTH OF HIGHWAY 50. COULD SEE SOME LIGHT ACCUMS OVER THE HIGHER
TRRN BUT NOT EXPECTING ANYTHING SIGNIFICANT. INHERITED LOW POPS FOR
THE PLAINS STILL LOOK ON TARGET SO HAVE NOT MADE ANY EXTENSIVE
CHANGES THERE.
SHOULD SEE SNOW TAPER OFF FROM N TO S ESPECIALLY AFTER MID-MORNING
ON MONDAY. JUST A FEW LINGERING SHOWERS OVER THE SRN MTS AND FAR
SERN PLAINS BY MON AFTERNOON. BREEZY CONDITIONS WILL PERSIST IN THE
WAKE OF THE LOW...ESPECIALLY OVER BACA COUNTY WHICH COULD SEE SOME
GUSTS IN THE 30-40 KT RANGE FOR THE LATE MORNING TO EARLY AFTERNOON
PERIOD. TEMPS ALOFT WILL ACTUALLY BE FALLING SIGNIFICANTLY THROUGH
MONDAY MORNING...DOWN TO AROUND MINUS 7 OR 8 C AT H7...BUT WITH GOOD
MIXING IN THE LOW TO MID LEVELS...SHOULD SEE TEMPS TOP OUT HIGHER
THAN THE TEMPS THIS AFTERNOON. HAVE CUT BACK TEMPS A BIT BELOW
GUIDANCE HOWEVER...SINCE EVEN WITH GOOD ADIABATIC MIXING THE TEMPS
ALOFT WILL PROBABLY ONLY SUPPORT 40 DEGREES OR SO AT BEST BY THE
AFTERNOON. SO...IT WILL BE A RAW DAY DESPITE THE LOWERED POPS.
ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
MONDAY NIGHT...UPPER LOW OVER WEST TEXAS FORECAST BY MODELS TO SLIDE
SOUTHEAST...BUT SOME MOISTURE IN NORTHERLY FLOW ALOFT WILL PERSIST
THROUGH PART OF THE NIGHT. INHERITED ISOLATED POPS AT MOST OVER THE
EASTERN MOUNTAINS THROUGH MIDNIGHT...AND THAT LOOKS GOOD. SNOW
ACCUMULATIONS WILL BE WELL UNDER AN INCH. LOW TEMPERATURES WILL BE
IN THE LOWER SINGLE DIGITS ACROSS THE SAN LUIS VALLEY...WITH SNOW
COVER AND RADIATIONAL COOLING. ELSEWHERE...TEMPERATURES SHOULD DIP
INTO THE TEENS ACROSS THE PLAINS AND OTHER HIGH VALLEYS...WITH
SINGLE DIGITS ACROSS THE HIGHEST ELEVATIONS.
FOR THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND...THE WEATHER
LOOKS TO BE FAIRLY TRANQUIL...AS AN UPPER LEVEL RIDGE GETS
ESTABLISHED OVER THE GREAT BASIN AND ROCKIES. A WEAK FRONT MAY
BRIEFLY AFFECT THE EASTERN PLAIN THANKSGIVING DAY...BUT WITH NO
PRECIPITATION. A COUPLE MORE SHORTWAVES IN THE NORTHERN
STREAM...WILL BRING SOME CLOUDS...WITH THE SECOND ONE...DURING THE
WEEKEND...BRINGING A CHANCE FOR SOME HIGHER ELEVATION SNOW SHOWERS.
-TLM-
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY AFTERNOON)
ISSUED AT 241 PM MST SUN NOV 24 2013
SNOW SHOWERS LINGERING OVER NRN EL PASO COUNTY SHOULD CONTINUE TO
MOVE OFF TO THE NW LATE THIS AFTERNOON. NO SIGNIFICANT ACCUMULATIONS
ARE EXPECTED WITH THIS ACTIVITY. KCOS COULD SEE ANOTHER ROUND OF
INTERMITTENT LIGHT SN LATER THIS EVE...BUT IT SHOULD NOT LAST LONG
AND SHOULD NOT LINGER MUCH BEYOND 12Z MON. KPUB WILL SEE CHANCES OF
SNOW LINGER A BIT LONGER INTO MON MORNING...BUT NOT EXPECTING MUCH
IN THE WAY OF ACCUMULATIONS THERE EITHER. IT CURRENTLY LOOKS LIKE
MOST OF THE HEAVIER SNOWFALL OVERNIGHT WILL STAY SOUTH OF HIGHWAY 50.
KALS WILL SEE A GOOD CHANCE OF LIGHT SNOW THROUGH THIS EVE AND
OVERNIGHT...WITH LIGHT ACCUMS OF A COUPLE INCHES POSSIBLE BY EARLY
MONDAY. SHOULD SEE CONDITIONS IMPROVE FROM NW TO SE THROUGH
MONDAY...WITH JUST SOME LINGERING SHOWERS OVER THE HYR TRRN. MAIN
STORY TOMORROW WILL BE THE INCREASED N-NE WINDS...WHICH WILL REMAIN
GUSTY OVER THE PLAINS THROUGH THE EARLY AFTERNOON BEFORE QUIETING
DOWN LATER IN THE DAY. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ060-066-
073>075-080.
WINTER STORM WARNING UNTIL 5 AM MST MONDAY FOR COZ068.
&&
$$
SHORT TERM...ROSE
LONG TERM...TM
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1030 PM MST SAT NOV 23 2013
.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 311 PM MST SAT NOV 23 2013
COMPLEX PATTERN TODAY AS COLDER AIR MOVED INTO SOUTHEAST UTAH...
LOWERING THE SNOW LEVELS TO THE VALLEY FLOORS. BUT SOUTHWEST
COLORADO HAS STAYED IN THE WARM SECTOR WITH THE SNOW LEVEL AROUND
8000 FEET. TELLURIDE AWOS OBSERVED LIGHT RAIN EARLIER TODAY.
SOUTHWEST COLORADO HAS BEEN A CHALLENGE WITH RESPECT TO
PRECIPITATION TYPE DURING THE PAST DAY OR TWO. CONFIDENCE IS
INCREASING THAT SNOW LEVELS WILL LOWER TO THE VALLEY FLOORS
(EXCEPT SOUTH OF CORTEZ) AS THE MOIST CONVEYOR BELT OVER ERN
ARIZONA SHIFTS INTO NWRN NEW MEXICO AND EXTREME SWRN COLORADO.
MID LEVEL TEMPS IN THE CONVEYOR BELT ARE COLDER AND DIABATIC
COOLING PROCESSES WILL RESULT IN RAIN CHANGING OVER TO SNOW. WITH
SOUTHEAST LOW LEVEL FLOW...THE RAP AND DOWNSCALED 5KM NAM SHOW THE
QPF BULLSEYE ALONG THE MONTEZUMA/LA PLATA COUNTY LINE AND
MONTICELLO UTAH WITH AREAS EXCEEDING 1 INCH OF PCPN DURING THE
NEXT 12 HOURS. THIS EQUATES TO A SNOW ACCUMULATION OF 6-12 INCHES
OF "SIERRA CEMENT" (HEAVY WET SNOW) FOR THE THIS AREA OVERNIGHT.
FOR EAST CENTRAL UTAH AND THE UNCOMPAHGRE/GRAND VALLEY...SOUTHEAST
FLOW WILL A WARMING EFFECT THAT ERODES THE COLDER SURFACE AIR.
THIS ELIMINATES THE CHANCE OF A REPEAT PERFORMANCE OF HEAVY SNOW
FROM CANYONLANDS NATIONAL PARK TO DEBEQUE CANYON. THE OVERRUNNING
PATTERN WILL NO LONGER EXIST AND THE AREAL EXTENT OF PRECIPITATION
WILL HAVE LESSENED. FARTHER NORTH...MOSTLY DRY ALTHOUGH SOME
DISSIPATING BANDS OF LIGHT SNOW MAY GENERATE FLURRIES OVER NE
UTAH/NW COLORADO.
SUNDAY AND SUNDAY NIGHT...THE CLOSED UPPER LOW WILL BE WEAKENING
AS IT MOVES INTO NWRN NEW MEXICO. ACTIVE WEATHER WILL STILL EXIST
BENEATH THE UPPER LOW SO ACCUMULATING SNOW CONTINUES ACROSS SW
COLORADO. THE MOISTURE FIELD OVER ERN UTAH AND NORTHWEST COLORADO
WILL BE ERODING. AS THE LOW CONTINUES TO TRACK ACROSS NEW
MEXICO...LOW LEVEL FLOW BECOMES NORTHWEST WHICH FAVORS THE NWRN SAN
JUANS AND THE SRN UNCOMPAHGRE PLATEAU (DALLAS DIVIDE/RIDGWAY AND
OURAY). HOWEVER...SNOW RATES WILL BE DIMINISHING AS THE UPPER LOW
WILL BE MOVING DOWNSTREAM. BY THE TIME THE UPPER LOW DOES DEPART
THE REGION LATE SUNDAY NIGHT...STORM TOTAL QPF AND SNOWFALL WILL
BE QUITE IMPRESSIVE FOR THE SRN PORTION OF THE FORECAST AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 311 PM MST SAT NOV 23 2013
THE UPPER LOW WILL HAVE TRANSLATED EAST OF THE ROCKIES TO NEAR THE
TEXAS PANHANDLE BY SUNRISE ON MONDAY...THEN BE FORCED SOUTHWARD BY
A STRONG DIP IN THE NORTHERN STREAM ACROSS THE UPPER MISSISSIPPI
VALLEY. LINGERING WRAP AROUND MOISTURE WILL BE EXITING THE FAR
SOUTHERN CWA BY LATE MORNING AS THE UPPER LOW BEGINS TO BE FORCED
SOUTHWARD. THE RETREATING MOISTURE WILL BE REPLACED BY ANOTHER
BATCH OF HIGH LEVEL MOISTURE BEING TRANSPORTED IN ON THE NORTHERLY
STREAM. NAM/GFS DIFFERING A BIT WITH THE GFS SATURATING THE UPPER
END OF THE DENDRITIC LAYER NEAR 500MB. THE NAM A BIT MORE
AGGRESSIVE WITH SATURATION DOWN TO THE TOP OF THE NORTHERN DIVIDE
MOUNTAINS THROUGH A LARGER PORTION OF THE DENDRITIC LAYER. ASCENT
IS WEAK WITH OROGRAPHICS THE MAIN DRIVER IN THE NORTH FLOW SO
WOULD EXPECT ANY ACCUMULATIONS TO BE ON THE LIGHT SIDE. FOR NOW
WILL KEEP JUST SOME SMALL POPS IN PLACE THROUGH THE AFTERNOON
UNTIL MODEL AGREEMENT ALIGNS BETTER. TEMPERATURES ARE SURE TO BE
AFFECTED BY THE SNOW COVER ESPECIALLY OVER SOUTHEAST UTAH INTO
SOUTHWEST COLORADO SO UNDERCUT GUIDANCE NUMBERS IN MANY AREAS.
THERE SHOULD BE SLOW WARM-UP GOING INTO THE MID TO LATE WEEK PERIOD
THOUGH THE STRONG NORTHERN STREAM FLOW JUST OFF TO OUR NORTHEAST
WILL CONTINUE TO REINFORCE THE COLD AIR ALOFT. VALLEY INVERSIONS
STRENGTHENED BY SNOW PACK WILL CONTINUE TO PUT A DAMPER ON WARMING
SO AGAIN TEMPERATURES FROM BLENDED MODELS WERE LOWERED. A WEAK
WAVE PASSAGE ON THURSDAY MAY BRING A BIT OF PASSING HIGH CLOUDINESS
BUT IS NOT LIKELY TO ADD MUCH TO MIXING. OUT WEST...THE EASTERN
PACIFIC TROF WILL BE SPLITTING WITH ONE BATCH CATCHING THE
WESTERLIES ACROSS THE NORTHERN CONUS BORDER. THE OTHER MAIN BATCH
WILL CLOSE OFF ANOTHER LOW ALONG THE CALIFORNIA COASTLINE. SOME OF
THIS SOUTHERN ENERGY SHEARS OUT OF THE LOW AND PROGRESSES ACROSS
THE CENTRAL ROCKIES PULLING MOISTURE WITH IT. FOR NOW IT SEEMS
THIS WILL BE MAINLY IN THE FORM OF HIGH CLOUDINESS THROUGH THE
LATE WEEK PERIOD. SO FOR NOW A MAINLY DRY FORECAST LOOKS ON TRACK
FOR HOLIDAY TRAVEL WITH TEMPERATURES GRADUALLY WARMING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1022 PM MST SAT NOV 23 2013
VERY SIMILAR SCENARIO TO LAST NIGHT...AN AREA OF ENERGY AND
MOISTURE LIFTING ACROSS WESTERN COLORADO AND EASTERN UTAH TONIGHT
WITH A SOUTHERN EDGE OF MODERATE RAIN CURRENTLY NEAR KAIB.
ANOTHER BATCH OF PRECIP IS BEING PUSHED UP AGAINST THE SAN JUANS
IN THE FORM OF SNOW. EXPECT DETERIORATING FLIGHT CONDITIONS OVER MANY
OF THE TAF SITES OVERNIGHT WITH THE BIGGEST IMPACTS OVER KDRO AND
KTEX. RAIN SHOULD CHANGE OVER TO SNOW BY MORNING AT ALL SITES. MOUNTAIN
OBSCURATION WILL BE PROMINENT OVER MANY AREAS THROUGH SUNDAY NIGHT
BEFORE SOME DRYING BEGINS TO PUSH IN FROM THE NORTH.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER STORM WARNING UNTIL 3 AM MST MONDAY FOR COZ018-019.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR COZ021.
WINTER STORM WARNING UNTIL NOON MST SUNDAY FOR COZ022-023.
UT...WINTER STORM WARNING UNTIL 3 AM MST MONDAY FOR UTZ028.
WINTER WEATHER ADVISORY UNTIL NOON MST SUNDAY FOR UTZ029.
&&
$$
SHORT TERM...PF
LONG TERM...15
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS ALBANY NY
345 PM EST SUN NOV 24 2013
.SYNOPSIS...
THE CENTER OF THIS ARCTIC AIRMASS WILL MOVE ACROSS THE REGION TONIGHT.
WHILE SOME LAKE EFFECT CLOUDS AND SNOW SHOWERS ARE
POSSIBLE...THE SURFACE HIGH WILL BUILD INTO THE REGION FOR SKIES
TO BECOME MAINLY CLEAR OVERNIGHT. WINDS WILL SUBSIDE AND
TEMPERATURES WILL FALL TO THE LOWEST LEVELS THIS SEASON THUS FAR.
AS THIS HIGH MOVES OFFSHORE...WE TURN OUR ATTENTION TO A
DEVELOPING COASTAL STORM THAT WILL IMPACT THE REGION HEADING INTO
THE THANKSGIVING HOLIDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CENTER OF THIS ARCTIC AIRMASS WILL SETTLE ACROSS THE REGION
TONIGHT. THOSE H850 TEMPS PER THE RUC13 BOTTOM OUT NEAR -20C THIS
EVENING. THIS WILL KEEP LAKE EFFECT ACTIVITY GOING FOR MOST OF THE
NIGHT...HOWEVER...INVERSION LEVELS WILL DROP AS THAT SURFACE AND
LOW LEVEL RIDGE AXIS CREST OVER THE REGION. LOW LEVEL WINDS
CURRENTLY AROUND 330-350 DEGREES ARE EXPECTED TO BACK TOWARD
310-330 DURING TONIGHT THEN GRADUALLY TOWARD 270 DEGREES TOWARD
SUNRISE. WE WILL RETAIN SLIGHT CHANCE TO CHANCE POPS FOR SNOW
SHOWERS FOR PORTIONS OF THE CATSKILLS...SCHOHARIE VALLEY AND
EVENTUALLY INTO THE MOHAWK VALLEY AND ADIRONDACKS THROUGH THE
OVERNIGHT.
CLOUDS TOO WILL BE PROBLEMATIC AND MOST OF THE REGION SHOULD
BECOME MOSTLY CLEAR OVERNIGHT. LAKE CLOUDS WILL HANG ON CLOSER TO
THE LAKES WHERE THE AFOREMENTIONED AREAS WHERE LAKE EFFECT SNOW
SHOWERS ARE EXPECTED. TEMPERATURES WILL DROP BACK AT OR BELOW
ZERO FOR THE ADIRONDACKS TO SINGLE DIGITS AND AROUND 10 DEGREES
ELSEWHERE.
AS FOR THE WINDS...WE WILL RETAIN THE ADVISORY THROUGH THE EVENING
HOURS BUT EXPECTATIONS ARE FOR THE BOUNDARY LAYER TO DECOUPLE AND/OR
FOR THE RIDGE TO BUILD IN TO ALLOW THE WIND GUSTS TO SUBSIDE BELOW
ADVISORY LEVEL.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
...POTENT COASTAL STORM IS EXPECTED TO IMPACT THE REGION TUESDAY
INTO THURSDAY...
MOST OF THE ATTENTION ON THIS FORECAST HAS BEEN ON THE DEVELOPING
COASTAL STORM SET TO IMPACT HOLIDAY TRAVEL LEADING INTO
THANKSGIVING. LATEST TRENDS IN THE NCEP MODEL SUITE ALONG WITH
INTERNATIONAL GLOBAL MODELS ARE TRENDING A LITTLE FURTHER WEST
/THE GFS IS QUICKLY TRENDING IN THIS DIRECTION ALONG WITH THE MOST
OF THE ENSEMBLE MEMBERS/. THIS WOULD SUGGEST THAT THE BULK OF THE
PRECIPITATION WILL FALL IN THE FORM OF RAIN FROM THE HUDSON RIVER
VALLEY AND POINTS SOUTH AND EAST THROUGH THE HEART OF THE EVENT.
HOWEVER...WITH A FAIRLY TIGHT BAROCLINIC ZONE AND ANY SLIGHT
DEVIATION TO THIS TRACK WILL HAVE SIGNIFICANT IMPACTS TO PRECIP
TYPE ACROSS THE REGION. PER THE LOW LEVEL U/V COMPONENT FROM THE
GEFS...AT THIS TIME THE WARM AIR SHOULD ERODE THE COLDER AIR FOR
THE EASTERN 2/3RD OF THE CWFA AS WE WILL TREND IN THIS DIRECTION
FOR THE FORECAST.
MONDAY...
SURFACE HIGH CRESTS OVER THE REGION WITH LAKE EFFECT ACTIVITY
IMPACTING PORTIONS OF THE DACKS IN THE MORNING AS THE LOW LEVEL
FLOW CONTINUES TO BACK THROUGH THE DAY. OTHERWISE...MOST OF THE
DAY SHOULD REMAIN DRY AS TEMPERATURES REBOUND INTO THE 20S AND
SOME LOWER 30S AS THE H850 TEMPS "WARM" INTO THE NEGATIVE SINGLE
DIGITS TO AROUND -10C DURING THE AFTERNOON. WITHIN THIS WARM
ADVECTION...SOME INCREASE IN HIGH AND MID LEVEL CLOUD COVER IS
ANTICIPATED.
MONDAY NIGHT...
A RATHER FAST MOVING CLIPPER TYPE SYSTEM TRACKING IN-BETWEEN THE
GREAT LAKES REGION AND JAMES BAY WILL BRING A COLD FRONT ACROSS
THE REGION. THIS MAY TOUCH OFF SOME SNOW SHOWERS...ESPECIALLY
DOWNWIND OF LAKE ONTARIO...WITH ACCUMULATIONS 1-2 INCHES IN
PERSISTENT SNOW SHOWERS WILL GENERALLY ONE INCH OR LESS FOR THE
CWFA.
TUESDAY INTO WEDNESDAY...
AS SEEN IN THE H2O VAPOR LOOP...CUT OFF UPPER LOW OVER THE FOUR
CORNERS REGION AND A COUPLE OF STRONG PV IMPULSES APPROACHING LAKE
WINNIPEG ARE EXPECTED TO CARVE OUT A RATHER SIGNIFICANT TROUGH
OVER THE EASTERN THIRD OF THE CONUS DURING THIS TIME STEP OF THE
FORECAST. THESE WAVES ARE EXPECTED TO PHASE WITH CYCLOGENESIS
EVOLVING OVER THE SOUTHEAST-MID ATLANTIC REGION DURING WEDNESDAY.
A PRONOUNCED AGEOSTROPHIC RESPONSE WILL DEVELOP AS THE LOW LEVEL
WARM ADVECTION RAPIDLY INCREASES UP THE EASTERN SEABOARD. PWAT
ANOMALIES OF 1-3 STANDARD DEVIATIONS ABOVE NORMAL ARE EXPECTED FOR
MOST OF THE REGION WITH THE LOW LEVEL JET APPROACHING 4 STANDARD
DEVIATIONS ABOVE NORMAL. THE NAM IS THE OUTLIER WITH ITS
EXCEPTIONALLY HIGH QPF WITH THE GLOBAL MODELS MUCH MORE TAME AND
IN CLOSE AGREEMENT WITH 1-2 INCHES OF RAIN/WATER-EQUIVALENT FOR
THE EVENT. PRECIPITATION FROM THIS EVOLVING SYSTEM IS EXPECTED TO
DEVELOP SOUTH TO NORTH DURING TUESDAY AND OVERSPREAD THE REGION
TUESDAY NIGHT. AT THIS TIME...WITH A SLIGHTLY FURTHER WEST
SOLUTION...WE UTILIZED A BLENDED PARTIAL THICKNESS SCHEME FROM THE
GLOBAL MODELS WHICH SUGGESTS A LITTLE LIGHT SNOW INITIALLY THEN
QUICKLY CHANGING OVER TO A MIX LATE TUESDAY THEN CONTINUING TO
WARM TUESDAY NIGHT FROM AT LEAST THE HUDSON RIVER VALLEY AND
POINTS SOUTH AND EAST. TO THE WEST OF THIS LINE...A POTENTIALLY
PROLONGED PERIOD OF WINTRY MIX IS EXPECTED AS THIS MAY PROVE TO TO
BE VERY CHALLENGING ASPECT TO THIS FORECAST. IN COLLABORATION WITH
WPC-WWD...A SIGNIFICANT AMOUNT OF SNOW/SLEET/FREEZING RAIN IS
POSSIBLE FOR PORTIONS OF THE DACKS...WESTERN MOHAWK VALLEY AND
PERHAPS INTO THE SCHOHARIE VALLEY. WE WILL CONTINUE TO HIGHLIGHT
IN THE HWO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WEDNESDAY NIGHT THROUGH THURSDAY...THE 12Z MODELS AND GUIDANCE
CONTINUE TO SHOW A COASTAL STORM MOVE UP THE ATLANTIC COASTLINE.
THERE IS STILL A LARGE DISAGREEMENT IN TERMS WHAT THE
PRECIPITATION TYPE AND THE AMOUNT OF QPF THAT WILL ACCUMULATE
BETWEEN THE FORECAST MODELS. AS WE GO INTO LATE WEDNESDAY
NIGHT...SOME NEW 12Z MODEL DATA SHOWS A SECONDARY SURFACE LOW
PRESSURE SYSTEM DEVELOPING ACROSS CENTRAL NEW ENGLAND WITHIN A
FAVORABLE SYNOPTIC UPPER LEVEL DIVERGENCE REGION EMBEDDED IN A
STRONG VERTICALLY ORIENTED UPPER LEVEL JET...ACCOMPANIED BY A
DEVELOPING NEGATIVE TILTED UPPER LEVEL TROUGH MOVING EAST FROM
LAKE ERIE OVER CENTRAL PENNSYLVANIA. IF THIS MODEL RUN WERE TO
VERIFY...COLD NORTH TO NORTHWESTERLY FLOW ON THE BACKSIDE OF THE
DEPARTING LOW PRESSURE SYSTEM WILL ANCHOR IN ENOUGH COLD AIR FOR
THIS SYSTEM TO END AS SNOW AS THE MAIN LOW PRESSURE FEATURE MOVES
NORTHEAST OVER NEW BRUNSWICK. THE POSSIBILITY OF A COUPLE INCHES
OF SNOW...ESPECIALLY FROM THE SARATOGA REGION POINTS NORTH AND
WEST IS POSSIBLE AS T850 AND T925 WILL BE WELL BELOW 0C ACROSS THE
REGION AS WE GO PAST 00Z THURSDAY. ONE GENERAL CONSENSUS AS OF NOW
BETWEEN THE MODELS IS THAT THE BEST BAROCLINICITY AND Q-VECTOR
FORCING APPEARS TO BE JUST OFF THE SOUTHERN COAST OF LONG ISLAND
WHERE THE MOST CONCENTRATED QPF AMOUNTS WILL BE AS THE MAIN AREA
OF LOW PRESSURE MOVING NORTHEAST UP THE COASTLINE ALONG AN UPPER
LEVEL WAVE OF LOW PRESSURE. THEREFORE...FOR THE START OF THE LONG
TERM SECTION...VARIATIONS TO THE BAROCLINIC POSITION WITH
THICKNESSES WELL ABOVE 540 DAM AT 500 HPA AHEAD OF A SECONDARY
UPPER LEVEL LOW PRESSURE WAVE MOVING EAST FROM THE GREAT LAKES MAY
DELAY THE CHANGEOVER FROM RAIN TO WINTRY MIX AND SNOW UNTIL MID
THURSDAY MORNING. AT THIS TIME HOWEVER...THERE ARE STILL MANY
VARIATIONS IN PRECIPITATION TYPES AND EVEN TEMPERATURE OUTLOOKS
DURING THE EVENT SO FURTHER UPDATES WILL BE NEEDED AS WE GET
CLOSER TO THE EVENT.
THURSDAY NIGHT THROUGH SUNDAY...AS THE MAIN LOW PRESSURE SYSTEM
EXITS THE ATLANTIC COASTLINE WELL INTO CANADA...LARGE AREA OF
SUBSIDENCE WILL MOVE INTO THE REGION GIVING TRANQUIL WEATHER
CONDITIONS. WITH A NORTHWESTERLY FLOW MODERATING TO A MORE WESTERLY
FLOW BY SUNDAY...TEMPERATURES WILL STILL REMAIN BELOW NORMAL WITH
TEMPERATURES RANGING FROM THE MID 20S TO LOWER 30S FOR FRIDAY AND
SATURDAY WITH TEMPERATURES MODERATING FROM THE UPPER 20S TO MID 30S
BY SUNDAY ACROSS THE ENTIRE REGION.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE 24 HOUR PERIOD
ENDING 18Z MONDAY...WITH A COLD AND DRY NORTHWEST FLOW ACROSS THE
AREA AS HIGH PRESSURE BUILDS IN FROM THE WEST.
THE MAIN AVIATION CONCERN CONTINUES TO BE STRONG NORTHWEST WINDS
THIS AFTERNOON INTO THIS EVENING. SUSTAINED WINDS OF GENERALLY 17
TO 22 KT ARE EXPECTED...WITH GUSTS TO AROUND 30 TO 40 KTS. THE
STRONGEST WINDS WILL OCCUR AT KALB AND KPSF. AFTER SUNSET WINDS
SPEEDS WILL SLOWLY SUBSIDE...BUT GUSTS OF 15 TO 20 KTS WILL
CONTINUE UNTIL LATE EVENING OR MIDNIGHT. WINDS WILL DECREASE
FURTHER SHORTLY BEFORE SUNRISE MONDAY.
OUTLOOK...
MONDAY THROUGH MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: LOW OPERATIONAL IMPACT. CHANCE OF RA.
TUESDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN...IP.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. LIKELY RA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...SHSN.
THANKSGIVING DAY: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
&&
.HYDROLOGY...
NO HYDROLOGY PROBLEMS THROUGH EARLY THIS WEEK AS ICE WILL BE
BUILDING DUE TO SUB FREEZING TEMPERATURES INTO EARLY NEXT WEEK.
THEREAFTER...A POTENT COASTAL STORM WILL IMPACT THE REGION WITH
MODERATE TO POTENTIALLY SIGNIFICANT AMOUNTS OF WATER EQUIVALENT.
THE TIME FRAME WILL BE FROM TUESDAY AFTERNOON INTO WEDNESDAY
EVENING AS A COASTAL STORM COULD BRING 1.5 TO 2.5 INCHES OF LIQUID
EQUIVALENT PRECIPITATION TO THE REGION /LOCALLY HIGHER IS
POSSIBLE/. IT WILL BEGIN AS SNOW AND COULD LINGER AS SNOW IN THE
NORTHERN MOUNTAINS...HOWEVER IN MUCH OF THE REGION IT IS EXPECTED
TO CHANGE TO RAIN...RESULTING IN SIGNIFICANT WITHIN BANK RISES. IN
THIS STORMS WAKE IT WILL TURN SHARPLY COLDER AGAIN WEDNESDAY
NIGHT...WITH ICE FORMATION LIKELY TO BEGIN ANEW.
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...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR CTZ001-013.
NY...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ032-033-
038>043-047>054-058>061-063>066-082>084.
MA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MAZ001-025.
VT...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...LFM
AVIATION...JPV
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
958 PM EST MON NOV 25 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC COAST WILL MOVE EAST
AS A WEATHER SYSTEM DEVELOPS ALONG THE GULF COAST OF LOUISIANA.
LOWER CLOUDS NOW BLANKETING THE ENTIRE FA.
WATER VAPOR IMAGERY AND MSAS ANALYSIS SHOWING A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE HAS NOW DEVELOPED ALONG
THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC LIFT
AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING THE
FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR PLUS
SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL HOLD
OFF UNTIL THE OVERNIGHT HOURS. THE MODELS INDICATE ENOUGH WARMING
SHOULD OCCUR FOR ALL LIQUID PRECIPITATION. ALL SREF MEMBERS KEEP
THE SURFACE TEMPERATURE ABOVE FREEZING LATE TONIGHT...EVEN IN THE
NORTH PART. FREEZING RAIN IS NOT IMPOSSIBLE IN THE EXTREME NORTH
SECTION...BUT BELIEVE PRECIPITATION WILL BE LIGHT AT THE ONSET
LIMITING WET-BULB COOLING. ALSO...THE NAM AND GFS SHOW SURFACE
WET-BULB TEMPERATURES RISING ABOVE FREEZING BEFORE SIGNIFICANT
PRECIPITATION REACHES THE AREA LATE TONIGHT. DESPITE THE MODEL
GUIDANCE...THERE MAY BE LAYERS OF DRY AIR ALOFT WITH WET-BULB
COOLING WHICH COULD SUPPORT SLEET...MAINLY IN THE EXTREME NW
PORTIONS OF THE FA. BELIEVE ANY SLEET WOULD BE LIGHT AND WITH
SURFACE TEMPERATURES ABOVE FREEZING...SO NO ACCUMULATION SHOULD
OCCUR.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
MVFR CONDITIONS THROUGH MOST OF THE OVERNIGHT PERIOD THEN
DETERIORATING TO IFR BY 12Z.
HIGH PRESSURE WILL CONTINUE TO WEAKEN AND SHIFT EAST INTO THE
ATLANTIC AS LOW PRESSURE ALONG THE GULF COAST PUSHES NORTHEASTWARD.
DUE TO MOISTURE FLUX INTO THE AREA AHEAD OF THE APPROACHING
WEATHER SYSTEM...CEILINGS HAVE LOWERED TO MVFR AT ALL TAF SITES.
LIGHT RAIN SHOULD SPREAD INTO THE AREA AROUND 08Z AND CONTINUE
SPREADING TOWARD THE NORTHEAST AS THE SURFACE LOW APPROACHES. BY
12Z...WIDESPREAD RAINFALL IS EXPECTED AND CONDITIONS SHOULD
DETERIORATE RAPIDLY TO IFR. MAINLY MODERATE RAIN ON TUESDAY BUT
CANNOT RULE OUT SOME HEAVY RAIN AT TIMES PARTICULARLY AT CAE/CUB.
MODEL SOUNDINGS AND LOCAL SCHEME SHOWING WIND SHEAR DEVELOPING
TUESDAY MORNING. INTRODUCED WIND SHEAR OF 35 KNOTS FROM 12Z TO
18Z. ALSO WITH INCREASING INSTABILITY ALOFT...A FEW ELEVATED
THUNDERSTORMS ARE POSSIBLE BUT CONFIDENCE WAS TOO LOW TO INCLUDE
IN THIS TAF PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT AS A LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE
SOUTHEASTERN STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
707 PM EST MON NOV 25 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC COAST WILL MOVE EAST
AS A WEATHER SYSTEM DEVELOPS ALONG THE GULF COAST OF TEXAS AND
LOUISIANA. LOWER CLOUDS ALREADY ENTERING THE FA FROM THE WEST. STILL
COOL AND DRY CONDITIONS IN THE LOWER LAYERS.
WATER VAPOR IMAGERY AND MSAS ANALYSIS SHOWING A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE IS DEVELOPING
ALONG THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC
LIFT AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING
THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR
PLUS SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL
HOLD OFF UNTIL LATE TONIGHT. THE 1600 GMT HRRR INDICATED AREAS OF
LIGHT PRECIPITATION DEVELOPING IN THE WEST PART OF THE FORECAST
AREA AROUND MIDNIGHT...WITH THE BULK OF THE PRECIPITATION ABOUT TO
MOVE INTO THE WEST PART OF THE AREA AT 200 AM. USED THIS GUIDANCE
FOR THE TIMING.
THE MODELS INDICATE ENOUGH WARMING SHOULD OCCUR FOR ALL LIQUID
PRECIPITATION. ALL SREF MEMBERS KEEP THE SURFACE TEMPERATURE ABOVE
FREEZING LATE TONIGHT...EVEN IN THE NORTH PART. FREEZING RAIN IS
NOT IMPOSSIBLE IN THE EXTREME NORTH SECTION...BUT BELIEVE
PRECIPITATION WILL BE LIGHT AT THE ONSET LIMITING WET-BULB
COOLING. ALSO...THE NAM AND GFS SHOW SURFACE WET-BULB TEMPERATURES
RISING ABOVE FREEZING BEFORE SIGNIFICANT PRECIPITATION REACHES THE
AREA LATE TONIGHT. DESPITE THE MODEL GUIDANCE...THERE MAY BE
LAYERS OF DRY AIR ALOFT WITH WET-BULB COOLING WHICH COULD SUPPORT
SLEET. WE BELIEVE ANY SLEET WOULD BE LIGHT AND WITH SURFACE
TEMPERATURES JUST ABOVE FREEZING...NO ACCUMULATION SHOULD OCCUR.
WE USED THE COOLER TEMPERATURE GUIDANCE TONIGHT BECAUSE OF THE
DRY AIR IN PLACE AND EVAPORATIVE COOLING ASSOCIATED WITH THE
MOISTURE INCREASE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
MVFR CONDITIONS THROUGH MOST OF TONIGHT THEN DETERIORATING TO IFR
BY 09Z.
HIGH PRESSURE WILL CONTINUE TO WEAKEN AND SHIFT EAST INTO THE
ATLANTIC AS LOW PRESSURE ALONG THE GULF COAST PUSHES
NORTHEASTWARD. DUE TO MOISTURE FLUX INTO THE AREA AHEAD OF THE
APPROACHING WEATHER SYSTEM...CEILINGS HAVE LOWERED AND HAVE
ALREADY DROPPED TO MVFR AT OGB/AGS/DNL. LIGHT RAIN SHOULD SPREAD
INTO THE AREA AROUND 07Z-09Z AND CONTINUE SPREADING TOWARD THE
NORTHEAST AS THE SURFACE LOW APPROACHES. BY 12Z-14Z...WIDESPREAD
RAINFALL IS EXPECTED AND CONDITIONS SHOULD DETERIORATE RAPIDLY TO
IFR. MAINLY MODERATE RAIN ON TUESDAY BUT CANNOT RULE OUT SOME
HEAVY RAIN AT TIMES PARTICULARLY AT CAE/CUB. MODEL SOUNDINGS AND
LOCAL SCHEME SHOWING WIND SHEAR DEVELOPING TUESDAY MORNING.
INTRODUCED WIND SHEAR OF 35 KNOTS THROUGH 18Z. ALSO WITH
INCREASING INSTABILITY ALOFT...A FEW ELEVATED THUNDERSTORMS ARE
POSSIBLE BUT CONFIDENCE WAS TOO LOW TO INCLUDE IN THIS TAF
PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT AS A LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE
SOUTHEASTERN STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
748 PM EST MON NOV 25 2013
.SYNOPSIS...
ISSUED AT 340 PM EST MON NOV 25 2013
A CLIPPER SYSTEM WILL BRING LIGHT SNOW OR FLURRIES TO THE AREA
THROUGH THIS EVENING...WITH ONLY MINOR ACCUMULATIONS POSSIBLE. A
REINFORCING SHOT OF COLD AIR WILL SET THE STAGE FOR A POTENTIAL
HEAVY LAKE EFFECT SNOW EVENT TUESDAY NIGHT THROUGH WEDNESDAY
ACROSS FAR SOUTHWEST LOWER MICHIGAN AND PORTIONS OF NORTHWEST AND
NORTH CENTRAL INDIANA.
&&
.UPDATE...
ISSUED AT 700 PM EST MON NOV 25 2013
LEAD SHORTWAVE APPEARS TO BE QUITE SHEARED IN NATURE STRETCHING
FROM SOUTHERN LOWER MICHIGAN BACK INTO CENTRAL ILLINOIS THIS
EVENING. THIS WAVE WILL CONTINUE TO SLIDE EAST THROUGH THE AREA
THROUGH THE LATE EVENING. THE COMBINATION OF WEAK DPVA WITH THIS
FEATURE AND ASSOCIATED DOWNSTREAM WEAK 750-650 HPA FRONTOGENESIS
WILL SUPPORT AREA OF -SN OVERSPREADING MUCH OF EASTERN AND
SOUTHEAST PORTIONS OF THE AREA THROUGH MIDNIGHT. DRY NATURE TO AIR
MASS AND ELEVATED NATURE OF FORCING WILL ONLY LEAD TO A FEW TENTHS
OF SNOW ACCUMULATION FOR MOST LOCATIONS HOWEVER. MUCH DRIER MID
LEVEL AIR ADVECTING IN BEHIND THIS LEAD SHORT WAVE HAS CUT OFF
PRECIP ACROSS THE FAR NORTH EARLY THIS EVENING. WATER VAPOR
IMAGERY/21Z RAP INITIALIZATION DO SUGGEST PRESENCE OF NEXT
UPSTREAM VORT ACROSS SOUTHERN MINNESOTA WHICH WILL SLIDE INTO THE
WESTERN GREAT LAKES LATE TONIGHT. NOT COMPLETELY OUT OF THE
QUESTION THAT SOME PATCHY FREEZING DRIZZLE COULD ACCOMPANY THIS
WEAK FORCING...BUT GIVEN EXPECTED VERY LIGHT NATURE TO THE DRIZZLE
IF IT OCCURS WOULD EXPECT MINIMAL TO NO IMPACT SO WILL CONTINUE TO
OMIT FROM THE FORECAST. ONLY TWEAK TO PREVIOUS FORECAST WAS TO
INCREASE POPS SLIGHTLY ACROSS CENTRAL PORTIONS OF THE AREA WHERE
IT APPEARS SOME VERY WEAK ELEVATED FGEN RESPONSE HAS OCCURRED OVER
THE PAST HOUR OR TWO. EVEN ACROSS THESE LOCATIONS...ACCUMULATIONS
SHOULD ONLY TOTAL A TENTH OR TWO. ANOTHER WEAK WAVE FROM SOUTHERN
STREAM ACROSS CENTRAL ILLINOIS EVIDENT ON WATER VAPOR IMAGERY MAY
CLIP SOUTHERN PORTIONS OF FORECAST THROUGH EARLY PORTIONS OF THE
OVERNIGHT THAT COULD LEAD TO BRIEF ENHANCEMENT OF WEAK ELEVATED
FGEN...BUT LITTLE OR NO ACCUMULATION IS EXPECTED. TREND OF
DIMINISHING POPS FROM NORTHWEST TO SOUTHEAST STILL APPEARS
REASONABLE AND NO OTHER CHANGES MADE TO PREVIOUS FORECAST AT THIS
TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM EST MON NOV 25 2013
LEAD NORTHERN STREAM S/W CURRENTLY DIVING SOUTHEAST ACROSS UPPER
GREAT LAKES. WEAK SMALLER SCALE WAVES STREAMING NORTHEAST TOWARD THE
LOWER GREAT LAKES NOTED ON W/V IMAGERY THIS AFTN...EMANATING FROM
STRONG SOUTHERN LOW ACROSS PANHANDLE REGION. THE PHASING OF THESE
WEAKER P/V ANOMALIES ACROSS THE AREA...COMBINED WITH COMPACT
CORRIDOR OF DECENT ISENTROPIC LIFT...PROVIDING WIDESPREAD
PRECIPITATION ACROSS THE REGION PER RADAR. THESE SNOW SHOWERS HAVE
BEEN STRUGGLING TO REACH THE GROUND ALL DAY PER UPSTREAM SFC
OBS...GIVEN STOUT DRY BOUNDARY LAYER AND SFC DEWPOINT DEPRESSIONS ON
THE ORDER OF 10-15F. CONTINUED WITH PREVIOUS FCST TREND...MENTIONING
LIGHT SNOW WORDING/FLURRIES...ALONG WITH LIGHT ACCUMULATIONS ACROSS
THE AREA. CONFIDENCE HAS WANED FOR ANY ACCUMULATIONS GIVEN RADAR
TRENDS...HOWEVER STREAM OF MID LVL MOISTURE ADVECTING NE INTO THE
AREA NOTED ON W/V MAY LEND TO ENHANCE THESE RETURNS AND HELP TOP DOWN
SATURATION OF THE LAYER...COINCIDENT WITH THE CORRIDOR OF ISENTROPIC
LIFT.
CORRIDOR OF LIFT STRETCHES OFF TO THE EAST AFTER MIDNIGHT...WITH
DIMINISHING POPS REFLECTED IN THE GRIDS. STRONGER NORTHERN STREAM
P/V ANOMALY WILL SURGE SOUTHEAST THROUGH THE REGION ON TUESDAY...AND
WILL ATTEMPT TO PHASE WITH SOUTHERN STREAM P/V ANOMALY LATE TOMORROW
AND WEDNESDAY WELL SOUTHEAST OF THE REGION. ATLANTIC COAST SFC
CYCLONE WILL DEVELOP IN RESPONSE TO THESE FEATURES...AND BRING
WIDESPREAD PRECIP TO MUCH OF THE EASTERN US. HOWEVER...BEST
ISENTROPIC UPGLIDE SHOULD KEEP SNOWFALL SOUTH AND EAST OF THE AREA
THROUGH TUESDAY...ESPECIALLY GIVEN THE AGGRESSIVE NATURE OF THE
NORTHERN STREAM ENERGY SURGING SOUTHEAST THROUGH THE AREA.
THEREFORE...HAVE KEPT POPS OUT OF THE TUESDAY PERIOD ACROSS THE
SOUTHEAST PORTION OF THE AREA...BUT HEDGED WITH A CHANCE FLURRIES
MENTION CLOSE TO THE EDGE OF THE BEST MOISTURE/LIFT GRADIENTS. NO
MAJOR CHANCES TO TEMPS TONIGHT/TUESDAY.
ACCOMPANYING THIS STRONG NORTHERN P/V ANOMALY IS ANOTHER EARLY
SEASON SURGE OF ARCTIC AIR. THIS WILL PUSH THROUGH THE AREA TUESDAY
AFTERNOON. KEPT WITH A FLURRY MENTION ACROSS THE AREA IN THE
AFTERNOON IN THE WAKE OF THE ARCTIC FRONT. LAKE RESPONSE SHOULD
ACTIVATE TUESDAY AFTERNOON AS 850MB TEMPS CRASH TO -12C TO -13C BY
21Z TUESDAY. SHOULD BE RATHER DISORGANIZED BEFORE 00Z...AS LOW LVL
NORTHWEST FLOW SHOULD KEEP BANDING TO A MINIMUM DURING THIS PERIOD.
WENT WITH A FEW TENTHS OF SNOW ACCUMULATION ACROSS FAR SW LWR MI
FROM 18Z TO 00Z...BEFORE FLOW VEERS NORTHERLY INTO THE
OVERNIGHT...LEADING TO A SIGNIFICANT SINGLE BAND EVENT IN THE LONG
TERM PERIOD.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM EST MON NOV 25 2013
...SIGNIFICANT LAKE EFFECT SNOW EXPECTED TUE NIGHT-WED...
FCST THIS AFTN PREDICATED ON SHARPER H5 SOLUTIONS ALOFT INCLUDING
NAM/GEM/EC AND VARIOUS HIGHRES GUIDANCE AS POTENT SRN STREAM SW
PHASES W/SECONDARY NRN STREAM DROPPING SWD THROUGH NRN SK THIS AFTN.
VIGOROUS/SHARP LL CAA BURST XPCD TUE NIGHT W/DEEP NRLY LONG AXIS
FETCH DVLPG. CLEAR INDICATIONS OF LK SP CONNECTION WHICH WILL MOST
CERTAINLY AID IN BREATH OF LATENT MSTR FLUX AND MODULATE SNOWBAND
INTENSITY HIGHER. 30-35KT MEAN CLD BEARING LYR FLW SHLD ALSO YIELD A
FURTHER INLAND PENETRATION OF SNOWBANDS BUT WHERE REMAINS A BIG QN.
TYPICAL W-E SPREAD NOTED THIS AFTN ALTHOUGH A DECIDED CONSENSUS LIES
W/ERN CLUSTER OF SOLUTIONS INCLUDING MOST HIGHRES RENDITIONS ALG
W/GEM AND 4KM NAM. AT THIS POINT GIVEN HOLIDAY TRAVEL CONCERNS WILL
BROAD BRUSH A WATCH FOR LT TUE NIGHT-WED EVE ACRS MUCH OF THE WRN
CORNER. HWVR IMPACTS WILL LIKELY EXTEND FARTHER DOWNSTREAM AND WILL
ADDRESS IN HWO UPDATE.
FVRBL DGZ LOCATION WITHIN LVL OF NON DVRG NOTED IN XSCTNS ALG
W/MAXIMIZED RH AND STG ASCENT WOULD PORTEND A PD OF 1-2 INCH SNOWFALL
RATES LIKELY VRY LT TUE NIGHT INTO WED AFTN BFR WKNG. CONSERVATIVE
AGGREGATED QPF YIELDS A BROAD 6-10 INCH SNOW PLUME W/OBVIOUS HEAVIER
ACCUMS TIED TO PLACEMENT OF LK SP CONNECTED PLUME AND LESSOR ACCUMS
TIED TO WHERE WEAKER WRN DIPOLE DVLPS. BAND XPCD TO BREAKUP RAPIDLY
WED EVE IN RESPONSE TO QUICK FLATTEN OF FLW ALOFT AS EAST COAST
STORM LIFTS OUT AND AHD OF NXT UPSTREAM DISTURBANCE. TEMPS THROUGH
THE PD CONT COLD BUT MODERATION ON TAP THIS WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 700 PM EST MON NOV 25 2013
A WEAK LEAD SHORT WAVE AND VERY WEAK MID LEVEL FRONTOGENESIS
FORCING HAS ALLOWED FOR AN AREA OF LIGHT SNOW TO AFFECT NORTHERN
INDIANA THIS EVENING. VSBYS/CIGS GENERALLY SHOULD REMAIN MVFR WITH
PERHAPS A BRIEF PERIOD OF IFR VSBYS AT KFWA THROUGH 03Z...BUT
CONFIDENCE IN OCCURRENCE IS TOO LOW FOR TAF INCLUSION AT THIS
TIME. OVERALL CONFIDENCE IN CIG FORECAST IS ALSO RELATIVELY LOW
OVERNIGHT GIVEN SHALLOW MOISTURE TRAPPED BENEATH DRYING MID LEVEL
PROFILES...BUT DID CARRY HIGHER END MVFR CIGS AT KSBN THROUGH
DAYBREAK. A MORE VIGOROUS UPPER TROUGH WILL DROP INTO THE GREAT
LAKES REGION ON TUESDAY WITH AN ASSOCIATED COLD FRONTAL PASSAGE.
THIS WILL RESULT IN A WIND SHIFT TO THE NORTHWEST TUESDAY WITH
SOME GUSTS TO 15 TO 20 KNOTS POSSIBLE AT KSBN DURING THE
AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...LAKE EFFECT SNOW WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
EVENING FOR INZ003-004-012>015.
MI...LAKE EFFECT SNOW WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY
EVENING FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LMZ043-046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...NG
SHORT TERM...NG
LONG TERM...T
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1251 AM EST SUN NOV 24 2013
.SYNOPSIS...
ISSUED AT 724 PM EST SAT NOV 23 2013
A RIDGE OF HIGH PRESSURE ACCOMPANIED BY AN ARCTIC AIR MASS WILL
CONTINUE TO AFFECT THE REGION THROUGH SUNDAY. THIS COLD AIR OVER
THE WARMER LAKE MICHIGAN WATERS WILL RESULT IN CONTINUED LAKE
EFFECT SNOW SHOWERS ACROSS SOUTHWEST LOWER MICHIGAN AND NORTH
CENTRAL INDIANA THROUGH SUNDAY MORNING BEFORE DIMINISHING. SOME
MORE LIGHT SNOW IS POSSIBLE MONDAY AS AN UPPER LEVEL DISTURBANCE
TRACKS ACROSS THE GREAT LAKES.
&&
.UPDATE...
ISSUED AT 724 PM EST SAT NOV 23 2013
MULTI-BAND LAKE EFFECT WITH CELLULAR NATURE CONTINUES TO IMPACT
SOUTHWEST LOWER MICHIGAN AND NORTH CENTRAL INDIANA THIS EVENING.
FETCH CONSIDERATIONS AND EASTERN LAKE SHORE LAKE AGGREGATE
TROUGHING HAVE RESULTED IN PRIMARY AREA OF CONCERN FROM EXTREME
NORTHERN BERRIEN COUNTY EXTENDING SOUTHEASTWARD THROUGH SOUTHERN
CASS...ELKHART...AND NORTHEAST KOSCIUSKO COUNTIES. BOUNDARY LAYER
INSTABILITY AND STRENGTH OF LOW LEVEL FLOW HAS ALLOWED THESE BANDS
TO PENETRATE WELL INLAND WITH BRIEF PERIODS OF 1 TO 2 INCH PER
HOUR SNOWFALL RATES WITH MOST INTENSE BANDING. SUSTAINING THESE
TYPE OF SNOWFALL RATES HAS BEEN PROBLEMATIC HOWEVER DUE TO MORE
BROKEN...CELLULAR NATURE. OUTSIDE OF THIS MAIN BAND/STRONGEST LOW
LEVEL CONVERGENCE ZONE...GENERALLY ONLY A DUSTING TO A FEW TENTHS
OF AN INCH OF SNOW HAS BEEN REPORTED. ORGANIZATION HAS BEEN
SOMEWHAT LOOSE OVER PAST FEW HOURS POSSIBLY TIED SOMEWHAT INTO
PASSAGE OF UPPER LEVEL VORT MAX LATE AFTERNOON/EARLY EVENING. SOME
SYNOPTIC CONTRIBUTION EXPECTED OVERNIGHT HOWEVER...AS WEAK SHEARED
VORT MAX DOWNSTREAM OF APPROACHING RIDGE AXIS TRACKS INTO THE
WESTERN GREAT LAKES. THUS...WILL NEED TO WATCH FOR SOME BETTER
ORGANIZATION AS WE GET INTO THE LATE EVENING HOURS.
IT STILL APPEARS AS THOUGH MAIN LIMITING FACTOR FOG SIGNIFICANT
ACCUMULATIONS OVERNIGHT WILL CONTINUE TO BE VERY DRY NATURE TO THE
AIRMASS. NAM/RAP BUFFER SOUNDINGS SUGGEST PEAK LAKE INDUCED
INSTABILITY AROUND THE 06Z TIMEFRAME WITH FAVORABLE JUXTAPOSITION
OF STRONGEST LOW LEVEL VERTICAL MOTION WITH DGZ THROUGH THE
OVERNIGHT. HOWEVER...GRADUAL LOWERING OF INVERSION TOWARD MORNING
MAY TAKE STRONGEST VERTICAL MOTIONS JUST BELOW CORE OF DGZ BY 12Z.
GIVEN ABOVE FACTORS AND LIMITING FACTOR OF DRY LARGE SCALE AIR
MASS...STILL FEEL THAT PREVIOUS FORECAST IS IN GOOD SHAPE WITH
ADVISORY LEVEL ACCUMULATIONS. CONFIDENCE IN REACHING WARNING TYPE
ACCUMS GIVEN CELLULAR NATURE AND GRADUAL LOWERING INVERSION
HEIGHTS OVERNIGHT STILL QUITE LOW AND WILL NOT MAKE ANY CHANGES TO
GOING HEADLINES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 400 PM EST SAT NOV 23 2013
ARCTIC AIRMASS ASSOCIATED WITH 1050MB SURFACE HIGH IS CURRENTLY
ENGULFING THE REGION...LEADING TO FALLING TEMPS AND A DECENT LAKE
RESPONSE. 850MB TEMPS CONTINUE TO FALL INTO THE UPPER TEENS BELOW
ZERO AND 700MB DELTA-T`S ARE AT OR ABOVE 30C. CERTAINLY PLENTY OF
LAKE INDUCED INSTABILITY BUT DEGREE OF UPSTREAM DRY AIR AND LOW
LEVEL FLOW TRAJECTORIES REMAIN A LIMITING FACTOR. AS PREVIOUSLY
MENTIONED...SURFACE DEWPOINTS OVER WISCONSIN ARE HOVERING AT OR
BELOW ZERO. 330 DEGREE SURFACE WINDS GIVE A DECENT FETCH ALONG LAKE
MICHIGAN BUT MOISTURE AND SENSIBLE/LATENT HEAT FLUX CAN ONLY DO SO
MUCH...ESPECIALLY GIVEN STRONG GRADIENT AND MARGINAL UPSTREAM
PRECONDITIONING FROM WESTERN LAKE SUPERIOR. THIS IS BORNE OUT BY
RELATIVELY DRY NEAR SURFACE PROFILES ON FORECAST SOUNDINGS AND
CEILINGS GENERALLY ABOVE 3 KFT DURING THE DAY TODAY. DRY AIR ALOFT
IS ALSO PREVENTING CONVECTIVE DEPTHS FROM GETTING MUCH ABOVE 7
KFT...PER NAM AND RAP FORECAST SOUNDINGS. APPEARS TO BE SOME
SEMBLANCE OF FRICTIONAL CONVERGENCE OR THERMALLY-INDUCED PRESSURE
TROUGHING ALONG THE EASTERN SHORE OF LAKE MICHIGAN BUT STRONG
NORTHWEST GRADIENT IS DISRUPTING THE FORMATION OF A SINGLE DOMINANT
BAND AND HEAVIER SNOW SHOWERS HAVE BEEN FAIRLY SPORADIC AND
DISORGANIZED THROUGHOUT THE DAY. 12Z HI-RES GUIDANCE SUGGESTS BANDS
MAY BECOME A LITTLE BETTER ORGANIZED OVERNIGHT BUT THE
AFOREMENTIONED LIMITING FACTORS WILL REMAIN LARGELY IN PLACE THROUGH
THE MORNING WITH A STIFF NORTHWEST WIND...PERSISTENT SYNOPTIC-SCALE
DRY AIR ADVECTION...AND A WELL MIXED BOUNDARY LAYER. STRONG
INSTABILITY...LONG DURATION...AND NEARLY IDEAL DGZ PLACEMENT WILL
CONTINUE TO AT LEAST PARTIALLY OFFSET THOSE NEGATIVE FACTORS THOUGH
AND WILL CONTINUE TO SEE SPURTS OF HEAVIER SNOW SHOWERS THROUGH
TOMORROW MORNING THAT COULD EVENTUALLY ADD UP TO 3-5 INCHES IN THE
ADVISORY AREA. STILL DONT EXPECT WARNING CRITERIA SNOWFALL. THE ONLY
POSSIBLE EXCEPTION MAY BE IN CASS COUNTY MI WHERE 5-8 INCHES MAY BE
POSSIBLE IF A MORE ORGANIZED/FOCUSED BAND DEVELOPS BUT CONFIDENCE IN
THIS OCCURRING IS TOO LOW TO WARRANT AN UPGRADE AT THIS POINT.
BACKING LOW LEVEL WINDS AND PERSISTENT SUBSIDENCE/DRY AIR ADVECTION
WILL BRING AN END TO LAKE AFFECT SNOW SHOWERS AROUND MIDDAY TOMORROW.
OTHER MAIN STORY DURING THIS SHORT TERM PERIOD WILL BE THE VERY COLD
TEMPERATURES. STRONG GRADIENT AND LAKE INDUCED CLOUD COVER WILL
PREVENT ANY DECOUPLING OR RADIATIVE COOLING OVERNIGHT FOR MOST OF
OUR CWA BUT VERY COLD THERMAL PROFILES ADVECTING INTO THE AREA WILL
STILL SUPPORT LOWS GENERALLY IN THE MID TEENS. COMBINED WITH THE
WIND...IT WILL FEEL LIKE THE LOW SINGLE DIGITS IN SOME AREAS. HIGHS
TOMORROW WILL STRUGGLE TO GET OUT OF THE MID 20S GIVEN 925MB TEMPS
STILL AROUND -11C. MODELS CONTINUE TO STRUGGLE WITH THE MAGNITUDE OF
THIS COLD AIRMASS AND HAVE CONTINUED TO LEAN ON THE COOLER SIDE OF
GUIDANCE.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 PM EST SAT NOV 23 2013
PREFERENCE THIS AFTN LIES W/SHARPER H5 EVOLUTION ALOFT MID PD IN
RESPONSE TO EWD EJECTION OF STG SRN STREAM SW UNDERNEATH AMPLIFYING
NRN STREAM ACRS THE WRN LAKES WHICH PROVIDES A PATHWAY FOR SOME XPCD
PHASING ALOFT. AS SUCH AND IN TANDEM W/GEM/NAM/EC TRENDS...BUMPED
POPS CONSIDERABLY WED-THU FOR WHAT SHLD BE A SIG LK EFFECT SNOW
EVENT AS YET ANOTHER SURGE OF COLD CANADIAN AIR FUNNELS SWD ACRS THE
LAKES.
STEEP NW FLW ALOFT CONTS THROUGH THE END OF THE PD W/PROMISE OF
CONTD WELL BLO NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1243 AM EST SUN NOV 24 2013
PRIMARY LES BAND SHOULD REMAIN JUST N-E OF KSBN AIRFIELD FOR
REMNDR OF AM HOURS. LESSER ORGANIZED BAND TO WEST WITH LWR 30 DBZ
RETURNS TO SLIDE INTO KSBN OFF/ON NEXT FEW HOURS. THEREAFTER
DERISION OF DRY AIRMASS FM BENEATH AND LOWERING SUBSIDENCE
INVERSION LEADING TO THINNING MSTR LAYER WITH POTNL FOR FUEL ALT
CONDS BECOMING TOO LOW FOR MENTION BYND 09 UTC. WEAKENING RETURNS
ON SOUTHERN PERIPHERY OF PRIMARY BAND SHOULD LEAD TO OCNL MINOR
VSBY REDUCTIONS AT KFWA AS WELL...THOUGH INLAND SUSTENANCE SUCH
THAT VFR MET CONDS EXPECTED TO DOMINATE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
INZ004>006.
MI...LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
MIZ077>079.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LMZ043-046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...AGD
LONG TERM...T
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1136 AM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 1132 AM MST SUN NOV 24 2013
AXIS OF STRONG WINDS HAS DEVELOPED A BIT FARTHER SOUTH THAN
PREVIOUSLY EXPECTED...WITH BREAK IN CLOUDS ALLOWING DEEPER MIXING
TO OCCUR AS FAR SOUTH AS TRB RESULTING IN WINDS QUICKLY
APPROACHING ADVISORY LEVELS AND HAVE EXPANDED ADVISORY TO THE
SOUTH IN RESPONSE.
UPDATE ISSUED AT 904 AM MST SUN NOV 24 2013
WIND GUSTS OF 38 KTS AT LAA AND 41 KTS AT ITR IN THE LAST HOUR
INDICATE BOUNDARY LAYER BEGINNING TO TAP INTO STRONG JET OF LOW
LEVEL WINDS AS PER LATEST RAP AND KGLD VWP. AM A LITTLE CONCERNED
ABOUT AREA OF 50KTS OVER EASTERN COLORADO AT 1 KM AGL...BUT THAT
IS EXPECTED TO WEAKEN OVER THE NEXT 2 HOURS SO DO NOT ANTICIPATE
THE NEED FOR A HIGH WIND WARNING. A WIND ADVISORY DOES APPEAR
NECESSARY AND HAVE ISSUED ONE BASICALLY FOLLOWING EXPECTED CORE OF
STRONGEST 1 KM AGL WINDS THE NEXT FEW HOURS...WITH WINDS EXPECTED
TO DIMINISH IN THE AFTERNOON. MAY SEE SNOW SHOWERS MAKE IT INTO
THIS AREA OF STRONG WINDS...BUT THINK INTENSITY AND DURATION DOES
NOT WARRANT ANY KIND OF PREDOMINANT BLOWING SNOW ADVISORY.
&&
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE UPPER LEVEL LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
FORECAST AREA WILL MOVE SLOWLY ACROSS THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...LIGHT SNOW WILL
SPREAD NORTHWARD OUT OF EASTERN NEW MEXICO AND THE PANHANDLE
REGION OF TEXAS AND OKLAHOMA INTO PORTIONS OF EASTERN COLORADO AND
WESTERN KANSAS. THE BEST CHANCE OF ACCUMULATING SNOWFALL WILL BE
THIS MORNING MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE AN INCH
OR LESS OF TOTAL ACCUMULATION IS POSSIBLE.
THE UPPER LOW CENTER WILL PHASE INTO THE MAIN UPPER TROUGH THAT
DEEPENS OVER THE GREAT LAKES AND MISSISSIPPI VALLEY REGION
TONIGHT. THE LOW WILL THEN BEGIN TO MOVE SOUTHEASTWARD OVER TEXAS
WITH DRYER AIR ALOFT AND SUBSIDENCE MOVING OVER THE CENTRAL HIGH
PLAINS REGION TONIGHT. THE UPPER RIDGE AMPLIFYING OVER THE WESTERN
UNITED STATES MOVES OVER THE INTERMOUNTAIN REGION MONDAY NIGHT AND
TUESDAY AND BEGINS TO MOVE OVER THE ROCKIES ON TUESDAY NIGHT.
ALTHOUGH TEMPERATURES WILL BE GRADUALLY INCREASING THROUGH THE
FIRST PART OF THE WORK WEEK AS HIGH PRESSURE MOVES INTO THE
REGION...MODEL TRENDS HAVE BEEN CONSISTENTLY LOWERING TEMPERATURES
WITH EACH SUBSEQUENT MODEL RUN OVER THE PAST FEW DAYS. TEMPERATURES
WILL REMAIN COLDER THAN AVERAGE WITH DRY CONDITIONS EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE LARGE SCALE PATTERN SHOWS A LONGWAVE TROUGH OVER THE EASTERN
PORTION OF THE U.S. WITH AN UPPER RIDGE OVER THE ROCKIES.
THROUGHOUT THE EXTENDED...SEVERAL SHORTWAVE TROUGHS IN THE
NORTHWEST/WESTERLY FLOW ALOFT MOVE THROUGH THE NORTHERN
PLAINS...SENDING A FEW WEAK COLD FRONTS THROUGH THE CWA. THE COLD
AIR BEHIND THE FIRST FRONT IS KEPT WELL TO THE NORTH...SO
TEMPERATURES ARE NOT EXPECTED TO FLUCTUATE MUCH BEHIND THE FRONTAL
PASSAGE. THE FIRST FRONT MOVES THROUGH WEDNESDAY NIGHT INTO
THURSDAY AND THE NEXT FRONT...ASSOCIATED WITH WESTERLY/SOUTHWEST
FLOW ALOFT...MOVES THROUGH FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WITH THE NEXT FRONTAL PASSAGE ALSO ARE NOT EXPECTED
TO FLUCTUATE MUCH SINCE HIGHS SHOULD RECOVER AS THE SURFACE HIGH
QUICKLY PUSHES EAST BY SATURDAY AFTERNOON. FRONTAL PASSAGES WILL
ALSO REMAIN DRY AS THE MAIN FORCING WITH THESE WAVES ALSO REMAINS
NORTH OF THE CWA. TOWARDS THE END OF THE PERIOD...THE LARGE SCALE
PATTERN SHIFTS EAST WITH THE RIDGE FLATTENING AND MOVING OVER THE
CWA THURSDAY THROUGH SATURDAY...WHILE A CLOSED UPPER LOW REMAINS
OVER SOUTHERN CALIFORNIA AND SLOWLY MOVES EAST/SOUTHEAST WITH THE
SOUTHERN STREAM JET MOVING OVER THE CWA ON SATURDAY.
AS PREVIOUSLY MENTIONED...THE EXTENDED PERIOD SHOULD REMAIN
DRY...WITH INCREASING MID TO HIGH CLOUDS WITH FRONTAL PASSAGES.
TEMPERATURES SHOULD REMAIN SEASONABLE...WITH HIGHS IN THE MID 40S TO
LOW 50S AND LOWS IN THE 20S. ONCE EXCEPTION FOR HIGH TEMPERATURES
WILL BE WEDNESDAY...AS SURFACE HIGH PRESSURE OVER EASTERN KANSAS
EXTENDS INTO THE EASTERN PORTION OF THE CWA...FROM RED WILLOW TO
GOVE COUNTY AND EASTWARD...HIGHS COULD ONLY REACH THE UPPER 30S TO
LOW 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1034 AM MST SUN NOV 24 2013
VFR CONDITIONS EXPECTED FOR THE PERIOD WITH MAIN CONCERN BEING
STRONG SOUTHERLY WINDS ALONG THE KS AND CO BORDER. GLD WILL
CONTINUE TO SEE SUSTAINED WINDS BETWEEN 22 AND 27 KTS WITH GUSTS TO
4O KTS THROUGH THE NEXT FEW HOURS BEFORE WINDS GRADUALLY DIMINISH.
MCK MAY SEE A BRIEF PERIOD OF GUSTY WINDS...BUT THAT IS EXPECTED
TO BE SHORT LIVED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 4 PM MST /5 PM CST/ THIS AFTERNOON FOR
KSZ001-013-027-041.
CO...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR COZ090>092.
NE...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR NEZ079.
&&
$$
UPDATE...JRM
SHORT TERM...LOCKHART
LONG TERM...ALW
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1039 AM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 904 AM MST SUN NOV 24 2013
WIND GUSTS OF 38 KTS AT LAA AND 41 KTS AT ITR IN THE LAST HOUR
INDICATE BOUNDARY LAYER BEGINNING TO TAP INTO STRONG JET OF LOW
LEVEL WINDS AS PER LATEST RAP AND KGLD VWP. AM A LITTLE CONCERNED
ABOUT AREA OF 50KTS OVER EASTERN COLORADO AT 1 KM AGL...BUT THAT
IS EXPECTED TO WEAKEN OVER THE NEXT 2 HOURS SO DO NOT ANTICIPATE
THE NEED FOR A HIGH WIND WARNING. A WIND ADVISORY DOES APPEAR
NECESSARY AND HAVE ISSUED ONE BASICALLY FOLLOWING EXPECTED CORE OF
STRONGEST 1 KM AGL WINDS THE NEXT FEW HOURS...WITH WINDS EXPECTED
TO DIMINISH IN THE AFTERNOON. MAY SEE SNOW SHOWERS MAKE IT INTO
THIS AREA OF STRONG WINDS...BUT THINK INTENSITY AND DURATION DOES
NOT WARRANT ANY KIND OF PREDOMINANT BLOWING SNOW ADVISORY.
&&
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE UPPER LEVEL LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
FORECAST AREA WILL MOVE SLOWLY ACROSS THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...LIGHT SNOW WILL
SPREAD NORTHWARD OUT OF EASTERN NEW MEXICO AND THE PANHANDLE
REGION OF TEXAS AND OKLAHOMA INTO PORTIONS OF EASTERN COLORADO AND
WESTERN KANSAS. THE BEST CHANCE OF ACCUMULATING SNOWFALL WILL BE
THIS MORNING MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE AN INCH
OR LESS OF TOTAL ACCUMULATION IS POSSIBLE.
THE UPPER LOW CENTER WILL PHASE INTO THE MAIN UPPER TROUGH THAT
DEEPENS OVER THE GREAT LAKES AND MISSISSIPPI VALLEY REGION
TONIGHT. THE LOW WILL THEN BEGIN TO MOVE SOUTHEASTWARD OVER TEXAS
WITH DRYER AIR ALOFT AND SUBSIDENCE MOVING OVER THE CENTRAL HIGH
PLAINS REGION TONIGHT. THE UPPER RIDGE AMPLIFYING OVER THE WESTERN
UNITED STATES MOVES OVER THE INTERMOUNTAIN REGION MONDAY NIGHT AND
TUESDAY AND BEGINS TO MOVE OVER THE ROCKIES ON TUESDAY NIGHT.
ALTHOUGH TEMPERATURES WILL BE GRADUALLY INCREASING THROUGH THE
FIRST PART OF THE WORK WEEK AS HIGH PRESSURE MOVES INTO THE
REGION...MODEL TRENDS HAVE BEEN CONSISTENTLY LOWERING TEMPERATURES
WITH EACH SUBSEQUENT MODEL RUN OVER THE PAST FEW DAYS. TEMPERATURES
WILL REMAIN COLDER THAN AVERAGE WITH DRY CONDITIONS EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE LARGE SCALE PATTERN SHOWS A LONGWAVE TROUGH OVER THE EASTERN
PORTION OF THE U.S. WITH AN UPPER RIDGE OVER THE ROCKIES.
THROUGHOUT THE EXTENDED...SEVERAL SHORTWAVE TROUGHS IN THE
NORTHWEST/WESTERLY FLOW ALOFT MOVE THROUGH THE NORTHERN
PLAINS...SENDING A FEW WEAK COLD FRONTS THROUGH THE CWA. THE COLD
AIR BEHIND THE FIRST FRONT IS KEPT WELL TO THE NORTH...SO
TEMPERATURES ARE NOT EXPECTED TO FLUCTUATE MUCH BEHIND THE FRONTAL
PASSAGE. THE FIRST FRONT MOVES THROUGH WEDNESDAY NIGHT INTO
THURSDAY AND THE NEXT FRONT...ASSOCIATED WITH WESTERLY/SOUTHWEST
FLOW ALOFT...MOVES THROUGH FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WITH THE NEXT FRONTAL PASSAGE ALSO ARE NOT EXPECTED
TO FLUCTUATE MUCH SINCE HIGHS SHOULD RECOVER AS THE SURFACE HIGH
QUICKLY PUSHES EAST BY SATURDAY AFTERNOON. FRONTAL PASSAGES WILL
ALSO REMAIN DRY AS THE MAIN FORCING WITH THESE WAVES ALSO REMAINS
NORTH OF THE CWA. TOWARDS THE END OF THE PERIOD...THE LARGE SCALE
PATTERN SHIFTS EAST WITH THE RIDGE FLATTENING AND MOVING OVER THE
CWA THURSDAY THROUGH SATURDAY...WHILE A CLOSED UPPER LOW REMAINS
OVER SOUTHERN CALIFORNIA AND SLOWLY MOVES EAST/SOUTHEAST WITH THE
SOUTHERN STREAM JET MOVING OVER THE CWA ON SATURDAY.
AS PREVIOUSLY MENTIONED...THE EXTENDED PERIOD SHOULD REMAIN
DRY...WITH INCREASING MID TO HIGH CLOUDS WITH FRONTAL PASSAGES.
TEMPERATURES SHOULD REMAIN SEASONABLE...WITH HIGHS IN THE MID 40S TO
LOW 50S AND LOWS IN THE 20S. ONCE EXCEPTION FOR HIGH TEMPERATURES
WILL BE WEDNESDAY...AS SURFACE HIGH PRESSURE OVER EASTERN KANSAS
EXTENDS INTO THE EASTERN PORTION OF THE CWA...FROM RED WILLOW TO
GOVE COUNTY AND EASTWARD...HIGHS COULD ONLY REACH THE UPPER 30S TO
LOW 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1034 AM MST SUN NOV 24 2013
VFR CONDITIONS EXPECTED FOR THE PERIOD WITH MAIN CONCERN BEING
STRONG SOUTHERLY WINDS ALONG THE KS AND CO BORDER. GLD WILL
CONTINUE TO SEE SUSTAINED WINDS BETWEEN 22 AND 27 KTS WITH GUSTS TO
4O KTS THROUGH THE NEXT FEW HOURS BEFORE WINDS GRADUALLY DIMINISH.
MCK MAY SEE A BRIEF PERIOD OF GUSTY WINDS...BUT THAT IS EXPECTED
TO BE SHORT LIVED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 4 PM MST /5 PM CST/ THIS AFTERNOON FOR
KSZ001-013.
CO...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR COZ090>092.
NE...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR NEZ079.
&&
$$
UPDATE...JRM
SHORT TERM...LOCKHART
LONG TERM...ALW
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
909 AM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 904 AM MST SUN NOV 24 2013
WIND GUSTS OF 38 KTS AT LAA AND 41 KTS AT ITR IN THE LAST HOUR
INDICATE BOUNDARY LAYER BEGINNING TO TAP INTO STRONG JET OF LOW
LEVEL WINDS AS PER LATEST RAP AND KGLD VWP. AM A LITTLE CONCERNED
ABOUT AREA OF 50KTS OVER EASTERN COLORADO AT 1 KM AGL...BUT THAT
IS EXPECTED TO WEAKEN OVER THE NEXT 2 HOURS SO DO NOT ANTICIPATE
THE NEED FOR A HIGH WIND WARNING. A WIND ADVISORY DOES APPEAR
NECESSARY AND HAVE ISSUED ONE BASICALLY FOLLOWING EXPECTED CORE OF
STRONGEST 1 KM AGL WINDS THE NEXT FEW HOURS...WITH WINDS EXPECTED
TO DIMINISH IN THE AFTERNOON. MAY SEE SNOW SHOWERS MAKE IT INTO
THIS AREA OF STRONG WINDS...BUT THINK INTENSITY AND DURATION DOES
NOT WARRANT ANY KIND OF PREDOMINANT BLOWING SNOW ADVISORY.
&&
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE UPPER LEVEL LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
FORECAST AREA WILL MOVE SLOWLY ACROSS THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...LIGHT SNOW WILL
SPREAD NORTHWARD OUT OF EASTERN NEW MEXICO AND THE PANHANDLE
REGION OF TEXAS AND OKLAHOMA INTO PORTIONS OF EASTERN COLORADO AND
WESTERN KANSAS. THE BEST CHANCE OF ACCUMULATING SNOWFALL WILL BE
THIS MORNING MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE AN INCH
OR LESS OF TOTAL ACCUMULATION IS POSSIBLE.
THE UPPER LOW CENTER WILL PHASE INTO THE MAIN UPPER TROUGH THAT
DEEPENS OVER THE GREAT LAKES AND MISSISSIPPI VALLEY REGION
TONIGHT. THE LOW WILL THEN BEGIN TO MOVE SOUTHEASTWARD OVER TEXAS
WITH DRYER AIR ALOFT AND SUBSIDENCE MOVING OVER THE CENTRAL HIGH
PLAINS REGION TONIGHT. THE UPPER RIDGE AMPLIFYING OVER THE WESTERN
UNITED STATES MOVES OVER THE INTERMOUNTAIN REGION MONDAY NIGHT AND
TUESDAY AND BEGINS TO MOVE OVER THE ROCKIES ON TUESDAY NIGHT.
ALTHOUGH TEMPERATURES WILL BE GRADUALLY INCREASING THROUGH THE
FIRST PART OF THE WORK WEEK AS HIGH PRESSURE MOVES INTO THE
REGION...MODEL TRENDS HAVE BEEN CONSISTENTLY LOWERING TEMPERATURES
WITH EACH SUBSEQUENT MODEL RUN OVER THE PAST FEW DAYS. TEMPERATURES
WILL REMAIN COLDER THAN AVERAGE WITH DRY CONDITIONS EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE LARGE SCALE PATTERN SHOWS A LONGWAVE TROUGH OVER THE EASTERN
PORTION OF THE U.S. WITH AN UPPER RIDGE OVER THE ROCKIES.
THROUGHOUT THE EXTENDED...SEVERAL SHORTWAVE TROUGHS IN THE
NORTHWEST/WESTERLY FLOW ALOFT MOVE THROUGH THE NORTHERN
PLAINS...SENDING A FEW WEAK COLD FRONTS THROUGH THE CWA. THE COLD
AIR BEHIND THE FIRST FRONT IS KEPT WELL TO THE NORTH...SO
TEMPERATURES ARE NOT EXPECTED TO FLUCTUATE MUCH BEHIND THE FRONTAL
PASSAGE. THE FIRST FRONT MOVES THROUGH WEDNESDAY NIGHT INTO
THURSDAY AND THE NEXT FRONT...ASSOCIATED WITH WESTERLY/SOUTHWEST
FLOW ALOFT...MOVES THROUGH FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WITH THE NEXT FRONTAL PASSAGE ALSO ARE NOT EXPECTED
TO FLUCTUATE MUCH SINCE HIGHS SHOULD RECOVER AS THE SURFACE HIGH
QUICKLY PUSHES EAST BY SATURDAY AFTERNOON. FRONTAL PASSAGES WILL
ALSO REMAIN DRY AS THE MAIN FORCING WITH THESE WAVES ALSO REMAINS
NORTH OF THE CWA. TOWARDS THE END OF THE PERIOD...THE LARGE SCALE
PATTERN SHIFTS EAST WITH THE RIDGE FLATTENING AND MOVING OVER THE
CWA THURSDAY THROUGH SATURDAY...WHILE A CLOSED UPPER LOW REMAINS
OVER SOUTHERN CALIFORNIA AND SLOWLY MOVES EAST/SOUTHEAST WITH THE
SOUTHERN STREAM JET MOVING OVER THE CWA ON SATURDAY.
AS PREVIOUSLY MENTIONED...THE EXTENDED PERIOD SHOULD REMAIN
DRY...WITH INCREASING MID TO HIGH CLOUDS WITH FRONTAL PASSAGES.
TEMPERATURES SHOULD REMAIN SEASONABLE...WITH HIGHS IN THE MID 40S TO
LOW 50S AND LOWS IN THE 20S. ONCE EXCEPTION FOR HIGH TEMPERATURES
WILL BE WEDNESDAY...AS SURFACE HIGH PRESSURE OVER EASTERN KANSAS
EXTENDS INTO THE EASTERN PORTION OF THE CWA...FROM RED WILLOW TO
GOVE COUNTY AND EASTWARD...HIGHS COULD ONLY REACH THE UPPER 30S TO
LOW 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 440 AM MST SUN NOV 24 2013
CURRENTLY IT LOOKS LIKE VFR CONDITIONS WILL PREVAIL THROUGH THE
TAF PERIOD. CEILINGS AT KGLD ONLY REDUCED TO BKN060 IN THE LAST
FEW HOURS AS THE FIRST WEAK BAND OF LIGHT SNOW MOVED OVER THE TAF
SITE. SOUNDINGS EARLIER THIS MORNING INDICATED POSSIBLY LOWER
CEILINGS WITH A CONTINUING CHANCE OF LIGHT SNOW LATER THIS
MORNING. AFTER VIEWING RAP SOUNDINGS...IT APPEARS THAT THIS IS NO
LONGER THE CASE. GUIDANCE ALSO DID NOT INCLUDE LOWERED CEILINGS
BEYOND VFR. LOW CONFIDENCE IN THE FORECAST AS OF RIGHT NOW...WILL
MAKE ANY AMMENDMENTS IF AND WHEN NECESSARY. SOUTHERLY WINDS WILL
PICK UP TODAY TO AROUND 15 TO 25 KTS GUSTING FROM 25 TO 35 KTS.
WIND GUSTS SHOULD DIMINISH OVERNIGHT WITH A WIND SHIFT TO THE
NORTHWEST. OVERCAST AND BROKEN CEILINGS SHOULD BECOME SCATTERED
OVERNIGHT AS THE THE STORM SYSTEM SOUTH OF THE AREA MOVES
NORTH/NORTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY UNTIL 4 PM MST /5 PM CST/ THIS AFTERNOON FOR
KSZ001-013.
CO...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR COZ090>092.
NE...WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR NEZ079.
&&
$$
UPDATE...JRM
SHORT TERM...LOCKHART
LONG TERM...ALW
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
451 AM MST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE UPPER LEVEL LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
FORECAST AREA WILL MOVE SLOWLY ACROSS THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...LIGHT SNOW WILL
SPREAD NORTHWARD OUT OF EASTERN NEW MEXICO AND THE PANHANDLE
REGION OF TEXAS AND OKLAHOMA INTO PORTIONS OF EASTERN COLORADO AND
WESTERN KANSAS. THE BEST CHANCE OF ACCUMULATING SNOWFALL WILL BE
THIS MORNING MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE AN INCH
OR LESS OF TOTAL ACCUMULATION IS POSSIBLE.
THE UPPER LOW CENTER WILL PHASE INTO THE MAIN UPPER TROUGH THAT
DEEPENS OVER THE GREAT LAKES AND MISSISSIPPI VALLEY REGION
TONIGHT. THE LOW WILL THEN BEGIN TO MOVE SOUTHEASTWARD OVER TEXAS
WITH DRYER AIR ALOFT AND SUBSIDENCE MOVING OVER THE CENTRAL HIGH
PLAINS REGION TONIGHT. THE UPPER RIDGE AMPLIFYING OVER THE WESTERN
UNITED STATES MOVES OVER THE INTERMOUNTAIN REGION MONDAY NIGHT AND
TUESDAY AND BEGINS TO MOVE OVER THE ROCKIES ON TUESDAY NIGHT.
ALTHOUGH TEMPERATURES WILL BE GRADUALLY INCREASING THROUGH THE
FIRST PART OF THE WORK WEEK AS HIGH PRESSURE MOVES INTO THE
REGION...MODEL TRENDS HAVE BEEN CONSISTENTLY LOWERING TEMPERATURES
WITH EACH SUBSEQUENT MODEL RUN OVER THE PAST FEW DAYS. TEMPERATURES
WILL REMAIN COLDER THAN AVERAGE WITH DRY CONDITIONS EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE LARGE SCALE PATTERN SHOWS A LONGWAVE TROUGH OVER THE EASTERN
PORTION OF THE U.S. WITH AN UPPER RIDGE OVER THE ROCKIES.
THROUGHOUT THE EXTENDED...SEVERAL SHORTWAVE TROUGHS IN THE
NORTHWEST/WESTERLY FLOW ALOFT MOVE THROUGH THE NORTHERN
PLAINS...SENDING A FEW WEAK COLD FRONTS THROUGH THE CWA. THE COLD
AIR BEHIND THE FIRST FRONT IS KEPT WELL TO THE NORTH...SO
TEMPERATURES ARE NOT EXPECTED TO FLUCTUATE MUCH BEHIND THE FRONTAL
PASSAGE. THE FIRST FRONT MOVES THROUGH WEDNESDAY NIGHT INTO
THURSDAY AND THE NEXT FRONT...ASSOCIATED WITH WESTERLY/SOUTHWEST
FLOW ALOFT...MOVES THROUGH FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WITH THE NEXT FRONTAL PASSAGE ALSO ARE NOT EXPECTED
TO FLUCTUATE MUCH SINCE HIGHS SHOULD RECOVER AS THE SURFACE HIGH
QUICKLY PUSHES EAST BY SATURDAY AFTERNOON. FRONTAL PASSAGES WILL
ALSO REMAIN DRY AS THE MAIN FORCING WITH THESE WAVES ALSO REMAINS
NORTH OF THE CWA. TOWARDS THE END OF THE PERIOD...THE LARGE SCALE
PATTERN SHIFTS EAST WITH THE RIDGE FLATTENING AND MOVING OVER THE
CWA THURSDAY THROUGH SATURDAY...WHILE A CLOSED UPPER LOW REMAINS
OVER SOUTHERN CALIFORNIA AND SLOWLY MOVES EAST/SOUTHEAST WITH THE
SOUTHERN STREAM JET MOVING OVER THE CWA ON SATURDAY.
AS PREVIOUSLY MENTIONED...THE EXTENDED PERIOD SHOULD REMAIN
DRY...WITH INCREASING MID TO HIGH CLOUDS WITH FRONTAL PASSAGES.
TEMPERATURES SHOULD REMAIN SEASONABLE...WITH HIGHS IN THE MID 40S TO
LOW 50S AND LOWS IN THE 20S. ONCE EXCEPTION FOR HIGH TEMPERATURES
WILL BE WEDNESDAY...AS SURFACE HIGH PRESSURE OVER EASTERN KANSAS
EXTENDS INTO THE EASTERN PORTION OF THE CWA...FROM RED WILLOW TO
GOVE COUNTY AND EASTWARD...HIGHS COULD ONLY REACH THE UPPER 30S TO
LOW 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 440 AM MST SUN NOV 24 2013
CURRENTLY IT LOOKS LIKE VFR CONDITIONS WILL PREVAIL THROUGH THE
TAF PERIOD. CEILINGS AT KGLD ONLY REDUCED TO BKN060 IN THE LAST
FEW HOURS AS THE FIRST WEAK BAND OF LIGHT SNOW MOVED OVER THE TAF
SITE. SOUNDINGS EARLIER THIS MORNING INDICATED POSSIBLY LOWER
CEILINGS WITH A CONTINUING CHANCE OF LIGHT SNOW LATER THIS
MORNING. AFTER VIEWING RAP SOUNDINGS...IT APPEARS THAT THIS IS NO
LONGER THE CASE. GUIDANCE ALSO DID NOT INCLUDE LOWERED CEILINGS
BEYOND VFR. LOW CONFIDENCE IN THE FORECAST AS OF RIGHT NOW...WILL
MAKE ANY AMMENDMENTS IF AND WHEN NECESSARY. SOUTHERLY WINDS WILL
PICK UP TODAY TO AROUND 15 TO 25 KTS GUSTING FROM 25 TO 35 KTS.
WIND GUSTS SHOULD DIMINISH OVERNIGHT WITH A WIND SHIFT TO THE
NORTHWEST. OVERCAST AND BROKEN CEILINGS SHOULD BECOME SCATTERED
OVERNIGHT AS THE THE STORM SYSTEM SOUTH OF THE AREA MOVES
NORTH/NORTHEAST.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...ALW
AVIATION...ALW
AREA FORECAST DISCUSSION
NWS GOODLAND KS
222 AM MST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TUESDAY NIGHT)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE UPPER LEVEL LOW PRESSURE SYSTEM EXPECTED TO AFFECT THE
FORECAST AREA WILL MOVE SLOWLY ACROSS THE DESERT SOUTHWEST AND
SOUTHERN ROCKIES TODAY. AHEAD OF THIS SYSTEM...LIGHT SNOW WILL
SPREAD NORTHWARD OUT OF EASTERN NEW MEXICO AND THE PANHANDLE
REGION OF TEXAS AND OKLAHOMA INTO PORTIONS OF EASTERN COLORADO AND
WESTERN KANSAS. THE BEST CHANCE OF ACCUMULATING SNOWFALL WILL BE
THIS MORNING MAINLY ALONG AND SOUTH OF INTERSTATE 70 WHERE AN INCH
OR LESS OF TOTAL ACCUMULATION IS POSSIBLE.
THE UPPER LOW CENTER WILL PHASE INTO THE MAIN UPPER TROUGH THAT
DEEPENS OVER THE GREAT LAKES AND MISSISSIPPI VALLEY REGION
TONIGHT. THE LOW WILL THEN BEGIN TO MOVE SOUTHEASTWARD OVER TEXAS
WITH DRYER AIR ALOFT AND SUBSIDENCE MOVING OVER THE CENTRAL HIGH
PLAINS REGION TONIGHT. THE UPPER RIDGE AMPLIFYING OVER THE WESTERN
UNITED STATES MOVES OVER THE INTERMOUNTAIN REGION MONDAY NIGHT AND
TUESDAY AND BEGINS TO MOVE OVER THE ROCKIES ON TUESDAY NIGHT.
ALTHOUGH TEMPERATURES WILL BE GRADUALLY INCREASING THROUGH THE
FIRST PART OF THE WORK WEEK AS HIGH PRESSURE MOVES INTO THE
REGION...MODEL TRENDS HAVE BEEN CONSISTENTLY LOWERING TEMPERATURES
WITH EACH SUBSEQUENT MODEL RUN OVER THE PAST FEW DAYS. TEMPERATURES
WILL REMAIN COLDER THAN AVERAGE WITH DRY CONDITIONS EXPECTED.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 149 AM MST SUN NOV 24 2013
THE LARGE SCALE PATTERN SHOWS A LONGWAVE TROUGH OVER THE EASTERN
PORTION OF THE U.S. WITH AN UPPER RIDGE OVER THE ROCKIES.
THROUGHOUT THE EXTENDED...SEVERAL SHORTWAVE TROUGHS IN THE
NORTHWEST/WESTERLY FLOW ALOFT MOVE THROUGH THE NORTHERN
PLAINS...SENDING A FEW WEAK COLD FRONTS THROUGH THE CWA. THE COLD
AIR BEHIND THE FIRST FRONT IS KEPT WELL TO THE NORTH...SO
TEMPERATURES ARE NOT EXPECTED TO FLUCTUATE MUCH BEHIND THE FRONTAL
PASSAGE. THE FIRST FRONT MOVES THROUGH WEDNESDAY NIGHT INTO
THURSDAY AND THE NEXT FRONT...ASSOCIATED WITH WESTERLY/SOUTHWEST
FLOW ALOFT...MOVES THROUGH FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WITH THE NEXT FRONTAL PASSAGE ALSO ARE NOT EXPECTED
TO FLUCTUATE MUCH SINCE HIGHS SHOULD RECOVER AS THE SURFACE HIGH
QUICKLY PUSHES EAST BY SATURDAY AFTERNOON. FRONTAL PASSAGES WILL
ALSO REMAIN DRY AS THE MAIN FORCING WITH THESE WAVES ALSO REMAINS
NORTH OF THE CWA. TOWARDS THE END OF THE PERIOD...THE LARGE SCALE
PATTERN SHIFTS EAST WITH THE RIDGE FLATTENING AND MOVING OVER THE
CWA THURSDAY THROUGH SATURDAY...WHILE A CLOSED UPPER LOW REMAINS
OVER SOUTHERN CALIFORNIA AND SLOWLY MOVES EAST/SOUTHEAST WITH THE
SOUTHERN STREAM JET MOVING OVER THE CWA ON SATURDAY.
AS PREVIOUSLY MENTIONED...THE EXTENDED PERIOD SHOULD REMAIN
DRY...WITH INCREASING MID TO HIGH CLOUDS WITH FRONTAL PASSAGES.
TEMPERATURES SHOULD REMAIN SEASONABLE...WITH HIGHS IN THE MID 40S TO
LOW 50S AND LOWS IN THE 20S. ONCE EXCEPTION FOR HIGH TEMPERATURES
WILL BE WEDNESDAY...AS SURFACE HIGH PRESSURE OVER EASTERN KANSAS
EXTENDS INTO THE EASTERN PORTION OF THE CWA...FROM RED WILLOW TO
GOVE COUNTY AND EASTWARD...HIGHS COULD ONLY REACH THE UPPER 30S TO
LOW 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1041 PM MST SAT NOV 23 2013
MODELS DIVERGING ON HOW FAST AND HOW FAR NORTH TO BRING PRECIPITATION
AND RICHER LOWER LEVEL MOISTURE. AT THIS TIME IT WOULD SEEM THAT
THE NAM AND RUC ARE OVERDOING IT PER LATEST OBSERVATIONS. BOTH MODELS
ESPECIALLY THE NAM HAVE BEEN OVERDOING IT HERE RECENTLY. AT THIS
TIME IT LOOKS LIKE PRECIPITATION AND LOWER CEILINGS WILL NOT MOVE
IN UNTIL NEAR 12Z AT KGLD. WILL HAVE MVFR CEILINGS THERE UNTIL 18Z
WITH VERY LIGHT SNOW...ABOVE MVFR...AS WELL. EXPECT VFR CONDITIONS
AT KMCK THROUGH THE ENTIRE PERIOD. SOUTH WINDS WILL INCREASE FIRST
AT KGLD BETWEEN 06Z AND 12Z AND THEN KMCK BY LATE MORNING. THE
STRONGEST GUSTS WILL BE AT KGLD. GUSTS WILL STOP BY 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...LOCKHART
LONG TERM...ALW
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
157 AM CST Sun Nov 24 2013
...Updated long term section...
.SYNOPSIS...
ISSUED AT 1109 AM CST SAT NOV 23 2013
At 12z Saturday a -25c 500mb low was located over southern
California. A 300mb +100kt jet streak extended from the based of
this upper low northeast into the four corners region. A 700mb to
500mb deformation zone was located from Wyoming, across Colorado,
into Oklahoma and a 700mb baroclinic zone extended from southern
Colorado into northern Oklahoma. Along and south of this
baroclinic zone was also where the better 850mb to 500mb moisture
appears to be located based on upper air analysis. A surface to
850mb ridge axis extended from northeast New Mexico into southern
Nebraska. An area of high pressure at the surface at 12z was
located over the eastern Dakotas. The Dodge City sounding this
morning indicated a of drier air was located in the 900mb to 750mb
layer, however the Amarillo sounding indicated a deep layer of
moisture extending from the surface to the 700mb layer.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 218 PM CST SAT NOV 23 2013
Models this morning were all in decent agreement with the
southern California upper low slowly moving east across the
southwest United States over the next 24 hours. Ahead of this
upper trough, isentropic lift and moisture on the I290 and I295
surfaces will improve across southwest Kansas. As this moisture
and lift improves the clouds will thicken and lower with even some
light snow becoming possible across far southwest Kansas after 03z
based on the NAM. The latest HRRR was even a bit more aggressive
with the precipitation spreading into southwest Kansas after 00z
Sunday, and currently given the precipitation that was already
occurring near Amarillo as of 19z will begin to trend toward this
slightly quicker solution. This area of light snow will then
spread north and east through the overnight period but the better
moisture return and isentropic lift still appears to be confined
near and south of the Oklahoma border overnight. As a result not
expected much in the way of accumulation until the 300mb jet,
which was located over Arizona at 12z, begins to approach
southwest Kansas after 06z. Possible exception to this will be
extreme southwest Kansas near Elkhart.
Steady light snow will spread across southwest Kansas after 06z
Sunday as synoptic scale lift improves. Given that the moisture
and low level isentropic lift will already be in place am
currently leaning towards the NAM in snowfall amounts from roughly
06z to 18z Sunday. As a result snow amounts ranging from one to
around two inches still appear reasonable south of a Ulysses to
Dodge City to Pratt line. The higher 2 inch amounts will be mainly
confined near the Oklahoma border on Sunday. Given snow amounts of
around 2 inches being possible near the Oklahoma border was
considering a winter weather advisory, however at this time given
that this is expected to be only a marginal event over a small
area have decided to hold off with any type of headlines. Snow
accumulations of less than one inch is likely further north given
the late timing of the isentropic lift and depth of dry air
forecast in the lower levels.
.LONG TERM...(Monday through Saturday)
ISSUED AT 156 AM CST SUN NOV 24 2013
Upper level ridging will build across the Rockies early this
week...but will weaken as it moves across the western plains with
predominantly westerly mid level flow across the central and
southern plains for much of the remainder of the week. This should
keep much of the cold Canadian air to the northeast with
temperatures moderating back to seasonal averages across
southwestern Kansas. There will be one more arctic high push south
Tuesday and Wednesday. Wednesday highs are most uncertain given the
strength of this next arctic push...and the latest ECMWF suggests
temperatures remaining in the lower 30s much of the day. Wednesday
highs may need to be further lowered should this trend continue in
the models. Even if Wednesday is colder than currently forecast, it
will likely warm right back up Thursday as downslope moment really
takes over allowing temperatures to warm well into the 40s, if not a
bit warmer. The general zonal nature to the hemispheric pattern
does not favor mid-latitude cyclone development through the end of
the week, thus precipitation will not be in the forecast.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1211 AM CST SUN NOV 24 2013
CIGS will lower to MVFR/IFR today as warm advection brings plenty
of low level moisture northward from the panhandles. Some snow is
possible after 12z, especially at KGCK and eventually at KDDC
after 15Z. Winds will increase from the south today to 10-14 kts
as a surface trough develops in the lee of the Rockies.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 23 38 22 / 60 10 10 10
GCK 30 21 39 22 / 70 10 10 10
EHA 29 23 35 21 / 90 10 10 10
LBL 30 22 34 22 / 90 10 10 10
HYS 31 20 40 22 / 30 10 10 0
P28 28 24 38 23 / 50 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 4 PM CST /3 PM MST/ this afternoon
FOR KSZ061>063-074>078-084>088.
&&
$$
SHORT TERM...Burgert
LONG TERM...Umscheid
AVIATION...Finch
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1219 AM CST Sun Nov 24 2013
...Updated for aviation discussion...
.SYNOPSIS...
ISSUED AT 1109 AM CST SAT NOV 23 2013
At 12z Saturday a -25c 500mb low was located over southern
California. A 300mb +100kt jet streak extended from the based of
this upper low northeast into the four corners region. A 700mb to
500mb deformation zone was located from Wyoming, across Colorado,
into Oklahoma and a 700mb baroclinic zone extended from southern
Colorado into northern Oklahoma. Along and south of this
baroclinic zone was also where the better 850mb to 500mb moisture
appears to be located based on upper air analysis. A surface to
850mb ridge axis extended from northeast New Mexico into southern
Nebraska. An area of high pressure at the surface at 12z was
located over the eastern Dakotas. The Dodge City sounding this
morning indicated a of drier air was located in the 900mb to 750mb
layer, however the Amarillo sounding indicated a deep layer of
moisture extending from the surface to the 700mb layer.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 218 PM CST SAT NOV 23 2013
Models this morning were all in decent agreement with the
southern California upper low slowly moving east across the
southwest United States over the next 24 hours. Ahead of this
upper trough, isentropic lift and moisture on the I290 and I295
surfaces will improve across southwest Kansas. As this moisture
and lift improves the clouds will thicken and lower with even some
light snow becoming possible across far southwest Kansas after 03z
based on the NAM. The latest HRRR was even a bit more aggressive
with the precipitation spreading into southwest Kansas after 00z
Sunday, and currently given the precipitation that was already
occurring near Amarillo as of 19z will begin to trend toward this
slightly quicker solution. This area of light snow will then
spread north and east through the overnight period but the better
moisture return and isentropic lift still appears to be confined
near and south of the Oklahoma border overnight. As a result not
expected much in the way of accumulation until the 300mb jet,
which was located over Arizona at 12z, begins to approach
southwest Kansas after 06z. Possible exception to this will be
extreme southwest Kansas near Elkhart.
Steady light snow will spread across southwest Kansas after 06z
Sunday as synoptic scale lift improves. Given that the moisture
and low level isentropic lift will already be in place am
currently leaning towards the NAM in snowfall amounts from roughly
06z to 18z Sunday. As a result snow amounts ranging from one to
around two inches still appear reasonable south of a Ulysses to
Dodge City to Pratt line. The higher 2 inch amounts will be mainly
confined near the Oklahoma border on Sunday. Given snow amounts of
around 2 inches being possible near the Oklahoma border was
considering a winter weather advisory, however at this time given
that this is expected to be only a marginal event over a small
area have decided to hold off with any type of headlines. Snow
accumulations of less than one inch is likely further north given
the late timing of the isentropic lift and depth of dry air
forecast in the lower levels.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 150 PM CST SAT NOV 23 2013
Moderation of temperatures is expected in the extended period.
Values will start below normal Monday and end up around normal by
next Saturday. No precipitation is expected during the period as
moisture will remain well southeast of the area. A series of weak
front will move across the region next week with the main impact in
the form of wind shifts.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1211 AM CST SUN NOV 24 2013
CIGS will lower to MVFR/IFR today as warm advection brings plenty
of low level moisture northward from the panhandles. Some snow is
possible after 12z, especially at KGCK and eventually at KDDC
after 15Z. Winds will increase from the south today to 10-14 kts
as a surface trough develops in the lee of the Rockies.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 29 23 37 23 / 30 10 10 10
GCK 30 21 38 23 / 30 10 10 10
EHA 29 23 35 22 / 60 10 10 10
LBL 30 22 34 23 / 70 10 10 10
HYS 31 20 39 23 / 20 10 10 0
P28 28 24 36 24 / 50 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Finch
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1046 PM MST SAT NOV 23 2013
.UPDATE...
ISSUED AT 837 PM MST SAT NOV 23 2013
JUST COMPLETED AN UPDATE. CLOUDS HAVE INCREASED THROUGH THE
EVENING WITH THE SOUTHERLY WINDS BEGINNING THEIR INCREASE. MANY
LOCATIONS IN THE WESTERN AND CENTRAL PORTION OF THE FORECAST AREA
MAY HAVE ALREADY REACHED THEIR MINS WITH MUCH HIGHER WINDS
EXPECTED IN THE LATER HALF OF THE NIGHT. NAM HAS CAUGHT ON THIS
AND USED THIS COMBINED WITH REALITY TO ADJUST THE MINS AND DIURNAL
TREND.
IN REGARDS TO THE WINDS INCREASED THEM EARLIER...BEGINNING BETWEEN
06Z AND 12Z. AREA SOUNDINGS CONFIRMING WHAT MODEL DATA IS SHOWING
IN REGARDS TO PRECIPITATION CHANCES. STILL A LOT OF DRY AIR IN THE
LOW LEVELS AND WILL TAKE A WHILE TO SATURATE. THAT LOOKS TO HAPPEN
BETWEEN 06Z AND 12Z WITH HIGHER POPS LATER TONIGHT INTO TOMORROW.
SO REMOVED PRECIPITATION CHANCES AND STARTED THE INCREASE AFTER
06Z A LITTLE SLOWER THAN PREVIOUSLY DEPICTED. ALSO RAMPED UP THE
SKY COVER AS WELL PER SATELLITE AND LATEST GUIDANCE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 105 PM MST SAT NOV 23 2013
19Z WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED LARGE CLOSED LOW
CIRCULATION OVER THE EXTREME SOUTHWESTERN CONUS WITH SHORTWAVE
RIDGING IN PLACE ACROSS THE CWA. AT THE SFC...1047MB SFC RIDGE
AXIS WAS NOSING INTO EASTERN KANSAS WITH CWA ON WESTERN PERIPHERY
OF THIS FEATURE.
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE PRECIPITATION
CHANCES OVERNIGHT TONIGHT INTO TOMORROW. WHILE STORM SYSTEM IN THE
SOUTH WILL GENERALLY REMAIN WELL TO THE SOUTH OF THE CWA...PERIOD
OF ASCENT/MOISTURE ADVECTION EXPECTED TO DEVELOP TONIGHT WHICH MAY
BRING A PERIOD OF LIGHT SNOW TO AREA BTWN 09 AND 18Z. LOOKING AT
VARIOUS MODEL ISENTROPIC/STABILITY FIELDS...APPEARS THAT OVERALL
FORCING PRETTY WEAK WITH MAIN DIFFERENCE BETWEEN DRY/WET MODELS
ARE THE DEGREE OF POTENTIAL INSTABILITY PRESENT. NOT REAL
CONFIDENT IN MORE UNSTABLE SOLUTIONS SO FOR THE TIME BEING PLAN ON
TEMPERING POPS IN THE 20-40 PERCENT RANGE AND SNOW AMOUNTS. COULD
POSSIBLY SEE A FEW SPOTS OF 2-3 INCHES IN THE SOUTHWEST...BUT
THINK MOST LIKELY SCENARIO WILL BE AROUND AN INCH SOUTH OF
INTERSTATE. OTHERWISE...WINDS WILL SHIFT TO THE SOUTH AND INCREASE
LATE TONIGHT THROUGH SUNDAY INCREASING TO 20 TO 30 MPH DURING THE DAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 227 PM MST SAT NOV 23 2013
THE LARGE UPPER LOW OVER THE SOUTHWEST U.S. WILL LIFT NORTHEAST TO
THE CO-NM BORDER SUNDAY NIGHT BEFORE HEADING BACK SOUTHEAST ACROSS
THE GULF BY TUESDAY. WEAK ASCENT AHEAD OF THE UPPER LOW AND ITS
CLOSE PROXIMITY WILL RESULT IN A BRIEF PERIOD OF LIGHT
SNOW/FLURRIES AS SHOWN ON THE SREF. ANY SNOW AMOUNTS WILL BE
LIGHT AND CONFINED TO THE SOUTHERN HALF OF THE AREA.
THE REST OF THE EXTENDED PERIOD WILL BE UNDER THE INFLUENCE OF AN
UPPER RIDGE TUESDAY-WEDNESDAY WHICH WILL ULTIMATELY FLATTEN OUT
DURING THE WEEK. NO PRECIPITATION IS EXPECTED FOR THE REMAINDER OF
THE WEEK AS A RESULT.
AT THE SURFACE...A WEAK COLD FRONT WILL PUSH THROUGH MONDAY
FOLLOWED BY A REINFORCING CANADIAN AIR MASS WHICH DOMINATES
TUESDAY-WEDNESDAY. THIS WILL KEEP TEMPERATURES BELOW NORMAL THROUGH
AT LEAST MID-WEEK WITH HIGHS IN THE 30S MONDAY WARMING TO THE 40S
BY WEDNESDAY. THE LAST HALF OF THE WEEK WILL SEE A RETURN TO
NORMAL TEMPERATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1041 PM MST SAT NOV 23 2013
MODELS DIVERGING ON HOW FAST AND HOW FAR NORTH TO BRING PRECIPITATION
AND RICHER LOWER LEVEL MOISTURE. AT THIS TIME IT WOULD SEEM THAT
THE NAM AND RUC ARE OVERDOING IT PER LATEST OBSERVATIONS. BOTH MODELS
ESPECIALLY THE NAM HAVE BEEN OVERDOING IT HERE RECENTLY. AT THIS
TIME IT LOOKS LIKE PRECIPITATION AND LOWER CEILINGS WILL NOT MOVE
IN UNTIL NEAR 12Z AT KGLD. WILL HAVE MVFR CEILINGS THERE UNTIL 18Z
WITH VERY LIGHT SNOW...ABOVE MVFR...AS WELL. EXPECT VFR CONDITIONS
AT KMCK THROUGH THE ENTIRE PERIOD. SOUTH WINDS WILL INCREASE FIRST
AT KGLD BETWEEN 06Z AND 12Z AND THEN KMCK BY LATE MORNING. THE
STRONGEST GUSTS WILL BE AT KGLD. GUSTS WILL STOP BY 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...JRM
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
742 PM CST Mon Nov 25 2013
.UPDATE...
ISSUED AT 742 PM CST MON NOV 25 2013
A slightly more modest change in precipitation chances and other
sensible weather elements (weather, temperature, dewpoint, wind,
etc) for tonight and Tuesday morning, mainly over West Kentucky.
The current wave of precipitation and sub-synoptic lift is moving
out of the area, creating a small droplet size area of rain/mist,
as well as snow over the eastern 1/3 of the WFO PAH County warning
area.
Regional radar mosaic still showing 0 to 15/20 dBZ returns over
Central Arkansas, Southeast Misouri, Southeast Illinois, and into
Northwest Kentucky and Southwest Indiana shortly after 01z (7 pm
CST) this evening. This is coincident with the southern edge of a
differential deformation zone/moisture gradient on the 7.0 micron
(sensitive near 700 mb) and 7.4 micron (sensitive near 850 mb)
GOES Sounder Water Vapor channels. On the 11-3.9 micron GOES IR
difference channel, the aforementioned radar echoes are centered
within the mean plume of ice clouds, serving as seeder-feeder
source region.
The GEM (Canadian), SREF (Short Range Ensemble Forecast),
deterministic 18z GFS numerical guidance are similar to the high
resolution 3km HRRR model guidance for this evening and overnight.
We should see a resurgence of PoPs/Weather from the southwest into
the Missouri Bootheel and Southwest Kentucky after midnight (06z).
A sharp northern PoP/Weather gradient should develop over West
Kentucky after midnight, slowly working east-northeast through 8
am CST Tuesday, then continue to shift east during the day on
Tuesday. By 9 am CST Tuesday, most areas should remain above freezing
over the entire WFO PAH CWA, eliminating any travel concern.
For now, the most concentrated area for travel concerns between 11
pm Monday and 8 am Tuesday will be from Paducah KY (KPAH) and
Owensboro KY (KOWB) southward 25 to 30 miles through 5 am CST,
working slightly more southward another 10 to 15 miles between 5
am - 8 am CST. The combination and duration of temperatures
slightly below freezing, PoPs above 40%, and differential lift may
lead some slight glazing on elevated surface and some roadways.
For now, will issue a longer term Special Weather Statement to
address this area of travel concern, as well as post a Weather
Story graphic on the NWS Paducah web page and social media
outlets. May also highlight in the Hazardous Weather Outlook as well.
Given the marginal nature of the precipitation amounts (between
0.04" - 0.07") it will be a judgement call whether an advisory
will be needed overnight, since critical temperatures will focused
in areas where total precipitation will be less than 0.05" between
11 pm and 8 am CST. Given the effectiveness of de-icing agents
(salt, etc...) most roads should remain in good shape. The only
areas of concern will be any untreated roadways.
&&
.SHORT TERM...(This Evening through Tuesday night)
ISSUED AT 239 PM CST MON NOV 25 2013
Models were obviously too slow with precip onset with this
initial wave. Not an uncommon error. Light sleet, light rain
light snow mix across the area. Most notable precip has been
over west KY and southeast MO, near the TN state line over to
the MO bootheel region. We will maintain our SPS (Special Weather
Statement) approach vs. an advisory. A few slick spots certainly
possible though not getting really any reports of that.
Temperatures per KY mesonet into SEMO at or above freezing even
where precip has occurred. Site near Hickman is down to 32F.
Overall, still not a big deal event.
This lead wave will push the afternoon activity on to the east.
The question then becomes, how much more will we see overnight
into early Tuesday. Will maintain slight better chances overnight
south and east and taper off low chance PoPs NW overnight, and
continue with our SE 1/3 of the area PoPs Tuesday as the
southern and northern stream systems interact and draw moisture
into this area. Should be dry over the remainder of the region
Tuesday. A minimal mix precip type possible tonight into early
Tuesday a.m. Then precip should transition to mainly light
rain. Tuesday night will be dry and colder as arctic high
pressure builds south into the area.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 239 PM CST MON NOV 25 2013
With precipitation having moved east of the PAH forecast area,
Wednesday will see clearing skies as chilly and breezy conditions
persist through the day. With highs only in the lower 30s, wind
chill readings in the morning will start out in the single digits to
around 10 degrees, only improving to the lower 20s by afternoon.
The coldest period of the extended will continue into Wednesday
night, with lows in the middle to upper teens. Northwest winds at 5
to 10 mph in the evening will decrease and gradually turn back to
the southwest by daybreak.
High pressure over the central plains Wednesday will slide east of
the PAH fa by Thursday morning, thus the winds becoming southwest.
Southwest flow will lead to a gradual warm up through the weekend,
though readings will remain below normal. High temperatures on
Thanksgiving will only reach the middle to upper 30s, moderating to
the upper 40s to around 50 degrees Saturday and Sunday. Lows
Saturday night are expected to stay above freezing, which will be
the first night with above freezing temperatures since last
weekend.
ECMWF brings a surface low into the Great Lakes region by 12z
Sunday, dragging a cold front into the Mississippi River valley.
GFS is about 12 hours slower than the ECMWF. ECMWF spreads rain
across much of the PAH fa Saturday night, while GFS holds off until
late Sunday into Sunday night. Went with a compromise, keeping
Saturday night dry then including slight to low chance pops for
mainly southern Illinois and southeast Missouri on Sunday. Went
with chance pops across the entire area Sunday night into Monday.
Fortunately, temperatures look to be warm enough through the event
to keep precip all liquid.
&&
.AVIATION...
ISSUED AT 602 PM CST MON NOV 25 2013
A light wintry mix of precipitation will continue through the
evening over much of the area. Added a TEMPO group for MVFR ceilings
with light snow at KPAH and KOWB where a few periods of pure snow
will be possible.
The latest guidance hints at some seeder/feeder potential
straddling 12Z at KPAH, and throughout Tuesday morning at KOWB.
It looks like there may be enough warming aloft to create a
rain/snow mix with some potential for FZRA. Will stick with the
-RASN with MVFR ceilings at KPAH and KOWB for now. Would not be
surprised to see the wintry mix continue at least intermittently
through the night at KPAH and KOWB.
Light and variable winds will be the rule until Tuesday morning,
when light north winds are expected to develop. As surface high
pressure builds eastward across the area in the afternoon, gusts
up to 20kts will be possible. The gustiness will mostly be
confined to KCGI before Tuesday evening.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...Smith
AVIATION...DRS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
925 PM EST MON NOV 25 2013
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL PUSH OFFSHORE OVERNIGHT. LOW
PRESSURE WILL MOVE NORTHEAST OUT OF THE GULF OF MEXICO AND UP THE
EAST COAST ON TUESDAY AND WILL REACH THE VICINITY OF LONG ISLAND
BY WEDNESDAY MORNING. LOW PRESSURE WILL CONTINUE NORTHEAST THROUGH
THE REGION ON WEDNESDAY AND WILL SHIFT INTO THE MARITIMES
WEDNESDAY NIGHT. A STRONG NORTHWEST FLOW WILL SET UP BEHIND THE
STORM LATE WEDNESDAY NIGHT INTO THURSDAY. HIGH PRESSURE WILL
GRADUALLY BUILD IN FROM THE WEST THURSDAY NIGHT THROUGH FRIDAY.
HIGH PRESSURE WILL HOLD OVER THE REGION ON SATURDAY AND WILL SHIFT
OFFSHORE ON SUNDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
UPDATE...HAVE DELAYED THE TIMING OF PCPN INTO THE AREA...AS DEW
POINTS REMAIN IN THE SINGLE DIGITS. PLENTY OF VIRGA OUT THERE
RIGHT NOW...WITH LITTLE IN THE WAY OF SN IN METAR OBS. HI-RES
GUIDANCE LIKE THE RAP AND HRRR INDICATE A NARROW BAND OF
FRONTOGENESIS TO MOVE INTO NH AND WRN ME NEAR DAWN. COULD SEE A
STRIPE OF NEAR A HALF INCH ACCUM FROM ROUGHLY KLEB TO KIZG IF THIS
COMES TO FRUITION. THIS ACTUALLY CORRESPONDS FAIRLY WELL TO
UPSTREAM SATELLITE OBS...SO SEE NO REASON WHY THE MODELS MAY BE IN
ERROR. THE MAIN QUESTION WILL BE WHETHER THE COLUMN CAN SATURATE
ENOUGH FOR AN ACCUMULATING SNFL.
PREVIOUS DISCUSSION...WEAK OVER-RUNNING WILL SHIFT IN FROM THE
WEST OVERNIGHT AS LOW PRESSURE MEANDERS OVER SOUTHWEST QUEBEC.
WILL SEE INCREASING CLOUDS DURING THE EVENING HOURS WITH A CHANCE
OF SNOW SHOWERS EDGING INTO NORTHERN ZONES. HAVE GENERALLY GONE
WITH LOW CHANCE POPS FROM THE GFS AS LIFT RATHER WEAK. COULD SEE A
FEW STRAY SNOW SHOWERS DRIFTING INTO SOUTHERN ZONES AROUND
DAYBREAK BUT THESE WILL BE LIGHT AND SPOTTY WITH LITTLE OR NO
IMPACT. WILL BE ANOTHER COLD NIGHT DESPITE THE CLOUDS WITH LOWER
TO MID TEENS IN THE NORTH AND UPPER TEENS TO MID 20S IN THE SOUTH.
&&
.SHORT TERM /TUESDAY NIGHT/...
UPDATE...AFTER EXAMINING THE LATEST AVAILABLE DATE HAVE MADE A FEW
TWEAKS TO THE TUE FORECAST. ANY MIXED PCPN SHOULD BE LIMITED TO
NRN VALLEYS AND HIGH TERRAIN. ALONG THE COAST AND COASTAL PLAIN
ANY SNFL SHOULD QUICKLY CHANGE TO RA AS WAA INCREASES. DEEPER COLD
AIR IN THE MTNS SHOULD SUPPORT 1-3 INCHES SNFL BEFORE A FLIP TO A
BRIEF MIX THEN RA.
PREVIOUS DISCUSSION...WEAK OVER-RUNNING WILL SHIFT EAST OF THE
REGION ON TUESDAY. MAY CATCH A FEW SUNNY BREAKS BEFORE CLOUDS
INCREASE FROM THE SOUTH IN THE AFTERNOON. APPEARS ANY PRECIP
ASSOCIATED WITH LOW PRESSURE MOVING UP THE COAST WILL HOLD OFF
UNTIL AFTER SUNSET TUESDAY EVENING BUT HAVE INCLUDED SOME LOW
CHANCE POPS FOR SOUTHERN NEW HAMPSHIRE FOR THE EARLY EVENING. WILL
SEE HIGHS MUCH CLOSER TO NORMAL ON TUESDAY WITH MOST OF THE REGION
RANGING THROUGH THE 30S.
EXPECT MIXED PRECIPITATION TO BREAK OUT ACROSS SOUTHERN ZONES
DURING THE EVENING HOURS WITH NORTHERN ZONES SEEING SNOW AT THE
ONSET. WARMER AIR WILL QUICKLY FLOOD IN FROM THE SOUTH TUESDAY
EVENING SO ANY MIXED PRECIP IN SOUTHERN INTERIOR SECTIONS WILL
LIKELY GO OVER TO RAIN BY MIDNIGHT OR SHORTLY AFTER...BECOMING
HEAVY AT TIMES AFTER MIDNIGHT. IN THE FOOTHILLS AND MOUNTAINS WILL
SEE SNOW GOING OVER TO SLEET AND FREEZING RAIN AFTER MIDNIGHT WITH
SOME ICE ACCUMULATIONS LIKELY. AT THIS POINT IN TIME WINTER
WEATHER ADVISORIES SHOULD COVER THE SITUATION IN CENTRAL AND
NORTHERN AREAS. EXPECT SNOW ACCUMULATIONS OF 3 TO 5 INCHES BEFORE
THE CHANGE TO SLEET AND FREEZING RAIN IN FAR NORTHERN ZONES. ICE
ACCUMULATIONS ON TOP OF THE SNOW WILL BE IN THE .1 TO.3 INCH RANGE.
EXPECT TEMPS TO RISE THROUGH THE NIGHT AND HAVE GONE WITH A NON-
DIURNAL TEMP CURVE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
UPDATE...STRONG PRES FALLS TO THE S WILL SUPPORT A NLY COMPONENT
OF THE WIND. THIS SHOULD HELP COOLER AIR STAY LOCKED IN THE
INTERIOR LONGER. MAIN EFFECT WAS TO BRING HIGH TEMPS DOWN IN THE
INTERIOR...AS EFFECT ON SENSIBLE WX WILL JUST BE A COLDER RNFL.
VERY STRONG LLJ IN PLACE...HOWEVER DEGREE OF WAA ALOFT WILL CREATE
A STOUT TEMP INVERSION. WILL BE TOUGH TO FULLY MIX DOWN STRONGEST
WINDS...ALTHOUGH TURBULENT MIXING SHOULD STILL BE ENOUGH TO SEE
40-45 MPH GUSTS ALONG THE COAST. THE INTERIOR WILL HAVE MORE
TROUBLE MIXING DOWN THE WINDS...AS LLVL COOLER AIR WILL BE TOUGHER
TO FLUSH OUT.
NWP CONTINUES TO ADVERTISE A HEAVY RNFL EVENT WED INTO THU. WITH
STRONG SELY UPSLOPE COMPONENT TO THE WIND...MAX RNFL TOTALS MAY
PUSH 5 INCHES IN SPOTS. WILL MENTION THIS IN THE HWO...ALONG WITH
WINDS...AS THESE SEEM TO BE THE MAIN IMPACTS ATTM.
AS RAPIDLY DEEPENING LOW PRES PULLS THRU AND N OF THE AREA...PRES
WILL SHARPLY RISE BEHIND IT. THIS RISE/FALL COUPLET IS FORECAST TO
MORE OR LESS TRACK RIGHT OVER THE HEART OF THE CWFA. THIS WILL
SUPPORT ANOTHER ROUND OF STRONG WIND GUSTS...THIS TIME FROM A WLY
DIRECTION...FOR THE ENTIRE REGION.
PREVIOUS DISCUSSION...MODELS SHOWING A POTENTIAL HEAVY RAIN EVENT
FOR WEDNESDAY WITH 2-3 INCH QPF STORM TOTAL POSSIBLE OVER MUCH OF
THE FCST AREA. MODELS ALSO SHOWING MAX AMOUNTS MAY APPROACH 3.5
INCHES. IT HAS BEEN QUITE DRY OCT THRU NOV BUT STILL THIS MUCH QPF
WILL CREATE SHARP RISES ON STREAMS AND SMALLER RIVERS. ANY MIXED
PRCP PRIOR TO WEDNESDAY SHOULD QUICKLY TRANSITION TO RAIN EARLY
WEDNESDAY. WINDS PICK UP...MAINLY ALONG THE COAST AND HIGHER/MORE
EXPOSED TERRAIN WITH STRONG LOW LVL SOUTHERLY FLOW SETTING UP
AHEAD OF THE DEEPENING SFC LOW.
THE LOW AND A TRAILING COLD FRONT MOVE THRU WEDNESDAY EVENING WITH
RAIN AND ANY STRONG SOUTHERLY WINDS COMING TO AN END. BEHIND THE
SYSTEM MUCH COLDER AIR MOVES IN QUICKLY ON INCREASINGLY STRONG AND
GUSTY NW WINDS. PRCP LIKELY TO FALL ACROSS N/MT ZONES WITH ANY MIXED
QUICKLY CHANGING TO SHSN...WITH ACCUMULATIONS LIKELY AS AN UPPER
LEVEL SHORT WAVE MOVES THRU AND UPSLOPE NW FLOW TAKES OVER. SOME
-SHSN WILL FIND THEIR WAY TO THE COAST UNDER THE VIGOROUS UPR LVL
SYSTEM BUT DOWNSLOPE FLOW WILL HELP OFFSET INTENSITY.
THE UPR LVL TROF MOVES TO THE E THURSDAY MORNING BRINGING AN END TO
MOST -SHSN ACTIVITY THOUGH THE CONTINUED COLD UPSLOPE NW FLOW WILL
KEEP SOME -SHSN GOING ACROSS THE N/MT ZONES. A VERY COLD BLUSTERY
DAY ON THURSDAY FOR THE FCST AREA AS STRONG SFC PRES GRADIENT FROM
THE STRONG LOW PRES SYSTEM MOVING THRU THE MARITIMES SETS UP THE NW
FLOW WHICH LINES UP SFC AND ALOFT...THOUGH THE FLOW BECOMES MORE
WESTERLY AT 700 MB AND HIGHER.
HIGH PRES BUILDS IN FROM THE WEST THURSDAY NGT THRU FRIDAY NGT AS
VERY COLD AIR DOMINATES. THE STRONG GUSTY NW FLOW SLOWLY LETS UP
DURING THE PERIOD OF TIME. THE HIGH SETTLES OVER THE REGION
SATURDAY WITH FAIR BUT COOL WX. THE HIGH MOVES TO THE E ON SUNDAY AS
WARMER AIR BEGINS TO MOVE IN ON SW FLOW ALOFT. MOSTLY LIKELY TO STAY
DRY AS THE HIGH STILL HAS INFLUENCE OVER OUR WX. AN UPR LVL SYSTEM
AND INCREASING WARM AIR ADVECTION AND MOISTURE ADVECTION FROM THE
SW MAY BRING SOME LGT PRCP SUNDAY NGT AND MONDAY.
USED A BLEND OF MODELS AND MOS GUIDANCE ALONG WITH HPC QPF FOR
PERIODS 4 AND 5...THEN USED A SUPER BLEND OF VARIOUS MODELS AND MOS
GUIDANCE ...ALONG WITH BIAS CORRECTED GUIDANCE AND THE PREVIOUS
FORECAST FOR DAYS 4 THRU 8...EXCEPT INCREASED WINDS ON THURSDAY
OVER THE SUPER BLEND DUE TO STRONG PRES GRADIENT LINING UP SFC TO
FLOW ALOFT AND STRONG COLD AIR ADVECTION TO SUPPORT VERY STRONG
GUSTY NW WINDS.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...VFR TONIGHT THROUGH TUESDAY. IFR/LIFR CEILINGS/VSBY
DEVELOPING TUESDAY NIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...IFR/LIFR IN HEAVY RAIN
WEDNESDAY. GUSTY SOUTHERLY WINDS...WITH LLWS POSSIBLE IN THOSE
AREAS THAT DON`T SEE THE STRONG LOW LVL WIND FIELD MIX DOWN TO THE
SFC. SHSN WEDNESDAY NGT INTO THURSDAY...MOSTLY AFFECTING THE N/MT
AREAS WITH MVFR/IFR POSSIBLE. STRONG NW FLOW DEVELOPING WEDNESDAY
NGT AND BECOMING STRONGEST ON THURSDAY...BEFORE EASING UP FRIDAY.
&&
.MARINE...
SHORT TERM...DROPPING SCA`S FOR WESTERN AND CENTRAL
WATERS...INCLUDING CASCO BAY. CONTINUING SCA`S FOR WINDS AND SEAS
IN FAR EASTERN WATERS AND PENOBSCOT BAY TIL 00Z.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...STRONG SOUTHERLY FLOW ON
WEDNESDAY. MODELS SHOW A LOW LVL JET UPWARDS OF 90 KT AT 2K FT AND
SFC WINDS UP TO 40 KT. WINDS SHOULD MIX DOWN TO CREATE STORM FORCE
GUSTS. WILL ISSUE A MARINE STORM WATCH FOR WEDNESDAY. WILL ALSO
INCREASE WIND AND WAVE HEIGHT FORECASTS OVER GUIDANCE.
WINDS SHIFT TO NW AS THE SYSTEM GOES BY WEDNESDAY EVE. GUSTY NW FLOW
INCREASES WEDNESDAY NGT AND BECOMES STRONGEST ON THURSDAY WHEN GALES
MAY BE NEEDED. NW FLOW SLOWLY EASES UP FRIDAY THRU SATURDAY AS HIGH
PRES BUILDS IN FROM THE W. SEAS WILL CONT VERY CHOPPY BUT THE TREND
WILL BE FOR THEM TO SLOWLY SUBSIDE STARTING WEDNESDAY NGT...BUT MAY
NOT DROP BELOW SCA LEVELS UNTIL FRIDAY MORNING.
&&
.TIDES/COASTAL FLOODING...
WEDNESDAY...STRONG ONSHORE FLOW WILL CREATE A STORM SURGE THAT COULD
REACH 2 OR EVEN 3 FT. TIDE AT PWM PREDICTED TO BE AROUND 8 1/2 FT SO
SHOULD STAY BELOW THE 12 FT TIDAL FLOOD STAGE AT PORTLAND.
HOWEVER... THE STRONG ONSHORE FLOW WILL GENERATE VERY SIGNIFICANT
WAVE HEIGHTS WHICH MAY LEAD TO SPLASHOVER/BEACH EROSION ALONG THE
COAST.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...STORM WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY AFTERNOON
FOR ANZ150>154.
&&
$$
NEAR TERM...LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
1234 AM EST SUN NOV 24 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT WITH A STRONG NORTHWEST
FLOW SETTING UP BEHIND IT. HIGH PRESSURE WILL BUILD SOUTH OF NEW
ENGLAND SUNDAY THROUGH MONDAY. A COLD FRONT WILL SLOWLY APPROACH
FROM THE WEST MONDAY NIGHT AND TUESDAY AND WILL CROSS THE REGION
TUESDAY NIGHT. LOW PRESSURE WILL MOVE UP THE EAST COAST ON
WEDNESDAY. HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST
THURSDAY THROUGH FRIDAY. HIGH PRESSURE WILL CREST OVER THE REGION
ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1225 AM...A MINOR ESTF TO ADJUST 1ST PERIOD GRIDS TO REFLECT
MESONET. WINDS HAVE COME UP QUICKER ON THE WATERS AND THE GALE
WILL BE STARTED AS OF 05Z.
PREV DISC...
UPDATE...HAVE UPDATED POP ONCE AGAIN TO TRACK THE LATEST
BATCH OF SN SQUALLS CROSSING THE WHITE MTNS ATTM. THE 24/00Z HRRR
ACTUALLY HAS A VERY GOOD HANDLE ON THE CURRENT SPEED AND FAIR
ESTIMATE ON LOCATION OF THE SQUALL. SO HAVE BLENDED THE PREVIOUS
FORECAST WITH THIS LATEST GUIDANCE TO BRING THE OFFICIAL FORECAST
IN THAT DIRECTION FOR THE NEXT SEVERAL HOURS. WILL CONTINUE HEAVY
SNFL WORDING WITH THIS PCPN...AS EVEN THOUGH THE DURATION WILL BE
SHORT LIVED...THE INTENSITY WILL BE ENOUGH TO CAUSE TROUBLE.
PREVIOUS DISCUSSION...ARCTIC COLD FNT MAKING QUICK PROGRESS
TOWARDS THE CWFA ATTM. SHSN AND SQUALLS WILL BECOME MORE NUMEROUS
AS IT APPROACHES THIS EVENING. STRONG CAA IS DESTABILIZING THE
LLVLS...ALLOWING SHSN TO BECOME QUITE INTENSE AT TIMES. LOOKING AT
UPSTREAM OBS AND WEBCAMS...VSBYS WILL DROP TO 1/4SM OR LESS AT
TIMES. HAVE ADDED HEAVY SN WORDING TO SRN NH AND ADJACENT SWRN ME
FOR THE NEXT SEVERAL HOURS AS SQUALLS TRACK OVER THESE AREAS.
ADDITIONALLY...ABOVE FREEZING TEMPS TODAY WILL MEAN ROAD TEMPS
WILL BE WARM ENOUGH TO MELT SNFL INITIALLY. HOWEVER...RAPIDLY
FALLING TEMPS WILL MEAN THIS WILL REFREEZE...CREATING VERY ICY
ROADWAYS. SEEING AS THESE SHSN WILL BE CROSSING INTERSTATES
89...93...AND 95 THIS IS A CONCERN. USED A BLEND OF THE LATEST RAP
AND HRRR TO TREND POP OVER THE NEXT FEW HOURS. OTHERWISE FORECAST
LOOKS ON TRACK AS BITTER COLD HEADS TOWARDS THE REGION.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM MONDAY/...
FOR SUNDAY WE HAVE ISSUED A WIND ADVISORY. LOOKING AT BUFKIT DATA
SHOWS WINDS TO 40 TO 50 KTS DOWN TO 2K FEET WITH STEEP LAPSE
RATES. THE STRONGEST WINDS ARE LIKELY TO BE IN THE 18Z TO 03Z TIME
FRAME. WINDS GUSTS TO 45 TO 50 MPH ARE CERTAINLY POSSIBLE. EXPECT
THERE WILL BE POWER OUTAGES AS THE DAY GOES ON. TEMPERATURES WILL
RISE ABOUT 5 TO 10 DEGREES TOMORROW WHICH WILL PUT HIGH TEMPS IN
THE 20S MOST EVERYWHERE WITH SOME UPPER TEENS IN THE MOUNTAINS.
THIS IS A GOOD 20 DEGREES BELOW NORMAL. SNOW SHOWERS WILL BE
LIKELY IN THE MOUNTAINS WITH 1 TO 3 INCHES POSSIBLE. FOR SUNDAY
NIGHT WINDS WILL ABATE SOMEWHAT AFTER MIDNIGHT BUT TEMPS WILL
PLUNGE. EXPECT AROUND ZERO IN THE MOUNTAINS AND NEAR 10 AT THE
COAST. RECORD LOW FOR PORTLAND MONDAY IS 9 DEGREES. WILL BE CLOSE
TO THIS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
RIDGE OF HIGH PRESSURE WILL CREST OVER THE REGION MONDAY BEFORE
SHIFTING OFFSHORE. EXPECT A SUNNY START TO THE DAY BEFORE HIGH
CLOUDS SPILL IN FROM THE WEST IN THE AFTERNOON. WILL BE ANOTHER COLD
ONE WITH HIGHS ONLY REACHING THE UPPER TEENS TO LOWER 20S NORTH AND
MID 20S TO NEAR 30 SOUTH.
AREA OF WEAK OVER-RUNNING AHEAD LOW PRESSURE MOVING THROUGH SOUTHERN
CANADA WILL PUSH IN FROM THE WEST MONDAY NIGHT BRINGING SOME LIGHT
SNOW TO THE REGION. BEST CHANCES OF PRECIP WILL BE IN NORTHERN ZONES
WHERE AN INCH OR TWO OF ACCUMULATION WILL BE POSSIBLE. ELSEWHERE
JUST LOOKING FOR A LIGHT DUSTING. LOOKING FOR LOWS IN THE MID TEENS
TO LOWER 20S.
CLOUDS AND LINGERING FLURRIES WILL GIVE WAY TO PARTLY SUNNY SKIES ON
TUESDAY. COLD FRONT APPROACHING FROM THE WEST MAY BRING SNOW SHOWERS
TO THE MOUNTAINS BY LATE IN THE DAY. SHOULD SEE A MUCH WARMER DAY
WITH TEMPS RANGING THROUGH THE 30S.
COLD FRONT WILL SWING THROUGH THE REGION TUESDAY NIGHT BRINGING A
CHANCE OF SNOW SHOWERS IN THE NORTH AND VARIABLE CLOUDS ACROSS
SOUTHERN AREAS. OVERNIGHT LOWS WILL RANGE THROUGH THE 20S.
MODELS STILL FAR APART ON WEDNESDAY WITH THE ECMWF BRINGING LOW
PRESSURE UP THE EAST COAST AND GFS TAKING THE SAME SYSTEM WELL
OFFSHORE. AT THIS POINT SUPER BLEND GIVING LIKELY POPS WITH A MIX OF
RAIN AND SNOW IN THE SOUTH AND SNOW IN THE FOOTHILLS AND NORTH. SO
POTENTIAL IS STILL THERE FOR SIGNIFICANT SNOW IN THE NORTH AND A
MESSY MIX IN THE SOUTH. HIGH TEMPS WILL RANGE THOUGH THE 30S TO
NEAR 40.
HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE WEST THURSDAY
THROUGH FRIDAY. EXPECT TEMPS ONCE AGAIN BELOW NORMAL THURSDAY AS
COLD CANADIAN AIR FLOODS IN ON A STRONG NORTHERLY WINDS. WILL SEE
TEMPS MODERATE SOMEWHAT ON FRIDAY AS HIGH PRESSURE CRESTS OVER THE
REGION.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...EXPECT MOSTLY VFR. BRIEF MVFR/IFR PSBL LATE TONIGHT
IN SNOW SHOWERS. HIE WILL SEE MOSTLY MVFR.
LONG TERM...VFR MONDAY THROUGH TUESDAY. IFR/LIFR CEILINGS AND VSBY
DEVELOPING ON WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
SHORT TERM...GALE WARNING HAS BEEN ISSUED.
LONG TERM...GALES POSSIBLE ON WEDNESDAY.
&&
.CLIMATE...
SIGNIFICANT OUTBREAK OF EARLY SEASON COLD AIR WILL CHALLENGE SOME
LOCAL RECORDS OVER THE NEXT COUPLE OF DAYS. AT KPWM THE RECORD
COLD MAXIMUM TEMP FOR 11/24 IS 28 SET IN 1989. THE TEMP AROUND
MIDNIGHT TONIGHT WILL LIKELY BE THE WARMEST KPWM GETS ALL
DAY...AND WILL BE VERY CLOSE TO 28 DEG. ON 11/25 KPWM HAS A RECORD
COLD MAXIMUM TEMP OF 29 SET IN 1993. THE CURRENT FORECAST IS FOR A
HIGH TEMP AROUND 30. FOR LOW TEMP ON 11/25...KPWM SET A RECORD IN
2000 OF 9 DEG. THE CURRENT FORECAST IS FOR 11/25 IS A LOW TEMP
AROUND 10 DEG.
A LITTLE COOLER BUT SIMILARLY FOR KCON...THE RECORD COLD MAXIMUM
TEMP FOR 11/24 IS 24 SET IN 1921. WHILE IN 1938 THE RECORD COLD
MAXIMUM TEMP FOR 11/25 WAS SET AT 21. THE RECORD LOW TEMP FOR
11/25 IS 5 DEG SET IN 1956 AND 2000.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR MEZ007>009-012>014-
018>028.
NH...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR NHZ001>010-013-014.
MARINE...GALE WARNING UNTIL 7 AM EST MONDAY FOR ANZ150>154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1211 PM EST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST SUN NOV 24 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE NRN GREAT LAKES WITH GRADUALLY RISING HEIGHTS AS THE
TROUGH OVER THE NE CONUS SLIDES TO THE EAST AND MID LEVEL RIDGING
BUILDS TOWARD THE AREA FROM SOUTH CENTRAL CANADA. AT THE SFC...A
RIDGE WAS BUILDING FROM NW WI AND WRN LAKE SUPERIOR INTO FAR W UPPER
MI WHILE LAKE INDUCED TROUGHING PREVAILED THROUGH ERN LAKE SUPERIOR.
SATELLITE AND RADAR INDICATED NW-SE ALIGNED WIND PARALLEL LES BANDS
HAD SHIFTED INTO LOCATIONS E OF MARQUETTE COUNTY. THE BANDS HAD
ALSO BECOME MORE CELLULAR WITH GRADUALLY DECREASING INTENSITY
OVERNIGHT. SFC OBS STILL INDICATED INTO W UPPER MI WITH CMX SHOWING
VSBY IN THE 1-3SM RANGE. HOWEVER...WEBCAMS FROM HOUGHTON AND CALUMET
SHOWED LITTLE SNOW OR VSBY REDUCTION.
THIS MORNING...
DESPITE 850 MB TEMPS AROUND -20C...INVERSION HEIGHTS DROPPING BELOW
5K FT AND VERY DRY AIR UPSTREAM WILL CONTINUE TO LIMIT LES
INTENSITY...ESPECIALLY OVER THE WEST. DIMINISHING WINDS WITH AN
INCREASED LAND BREEZE INFLUENCE AND A BACKING TREND WITH THE
APPROACHING RIDGE WILL RESULT IN A PERIOD OF ENHANCED CONVERGENCE
FROM ERN LAKE SUPERIOR INTO UPPER MI BETWEEN MUNISING AND NEWBERRY
WHERE ADDITIONAL SNOW AMOUNTS IN THE 1 TO 3 INCH RANGE ARE EXPECTED
THROUGH THE MORNING. THE BACKING WINDS SHOULD PUSH THE REMAINING LES
OFFSHORE IN THE AFTERNOON.
THIS AFTERNOON AND TONIGHT...
DEVELOPING WAA WITH STRONG 280K-295K PRES ADV BUT ONLY WEAK TO
MODERATE NET LIFT AHEAD OF A SHRTWV AND SFC LOW MOVING INTO CNTRL
MANITOBA MAY LEAD TO AN AREA OF LIGHT SNOW STREAKING SE INTO THE
NORTH AND EAST PORTIONS OF UPPER MI LATE THIS AFTERNOON AND EVENING.
HOWEVER...WITH THE DRY LOW LEVELS...LITTLE IF ANY SNOW ACCUMULATION
IS EXPECTED WITH ONLY SLIGHT CHANCE POPS INCLUDED. SNOW CHANCES WILL
INCREASE OVERNIGHT AS 700-300 MB QVECTOR CONV AHEAD OF THE SHORTWAVE
MOVES IN BUT SNOW AMOUNTS SHOULD REMAIN LESS THAN A HALF INCH. SW
FLOW LAKE ENHANCEMENT IS LIKELY TO DEVELOP OFF OF LAKE MICHIGAN BUT
THE LOW LEVEL WINDS VEER ENOUGH TO KEEP THE HIGHER SNOW
CHANCES/AMOUNTS TO THE SOUTH AND EAST OF SCHOOLCRAFT AND LUCE
COUNTIES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 440 AM EST SUN NOV 24 2013
NORTHERN STREAM REMAINS ACTIVE THROUGH THE WEEK KEEPING THE COLD
ACROSS THE GREAT LAKES. NEXT CHARGE OF ARCTIC AIR ARRIVES LATER
MONDAY NIGHT INTO TUESDAY. LK EFFECT SNOW INCREASES MONDAY NIGHT
THROUGH TUESDAY NIGHT. AFTER HIGH PRESSURE RIDGE/SUBSIDENCE BRINGS
DIMINISHING TREND TO LK EFFECT LATER WEDNESDAY...ANOTHER SHORTWAVE
DROPPING THROUGH MAY BRING SOME LGT SNOW FOR THANKSGIVING DAY.
AGREEMENT FALLS OFF BY NEXT WEEKEND WITH THE ECMWF KEEPING A NW FLOW
ALOFT ACROSS GREAT LAKES AND BRINGING ANOTHER CLIPPER THROUGH ON
SATURDAY. GFS IS SLOWER AND MORE DEVELOPED BUT FARTHER NORTH WITH
NEXT TROUGH DROPPING THROUGH BY LATE IN THE WEEKEND.
MODELS IN OKAY AGREEMENT THROUGH 12Z TUESDAY THEN THEY BEGIN TO SHOW
DIFFERENCES. OVERALL THOUGH EVEN THE DISAGREEMENT...SPEED OF INITIAL
SHORTWAVE MOVING THROUGH UPR LAKES...DOES NOT HAVE HUGE IMPACTS ON
THE OVERALL THEME OF FORECAST. GFS ENDS UP BEING QUICKER THAN
ECMWF/NAM AND GEM-NH WITH HANDLING OF INITIAL SHORTWAVE. PLAN IS
THAT ON MONDAY MORNING SHORTWAVE WILL BE NORTH OF LK SUPERIOR WITH
TROUGH AXIS DROPPING ACROSS UPR LAKES. SFC LOW/H85 LOW AND SFC
TROUGH SWINGS ACROSS WESTERN UPR MICHIGAN BY MIDDAY AND INTO THE
EASTERN CWA BY EVENING. MAY SEE LGT LK EFFECT WITH MARGINAL TEMPS
AT INVERSION TOP MOST OF THE DAY OVER THE WEST...BETTER CHANCES WILL
BE LATER ON THOUGH. HINT THAT WEAK WAVE IN THE SOUTHERN STREAM
SLIDES WSW-ENE ACROSS MAINLY SOUTHERN SECTIONS OF WESTERN GREAT
LAKES AND INTERACTS WITH H8-H7 FRONTOGENESIS AND RIGHT ENTRANCE
REGION OF JET FM CNTRL GREAT LAKES TO SOUTHERN QUEBEC MONDAY MORNING
THROUGH MID MONDAY AFTN. SOME LGT SYNOPTIC SNOW MAY SCRAPE LK
MICHIGAN ZONES AND FAR EAST. IF THERE IS ENOUGH LOW-LEVEL MOISTURE
TO START THE DAY...COULD EVEN SEE A BIT OF FZDZ ALONG WI BORDER AS
DEEPER MOISTURE HEADS EAST. LAKE ENHANCEMENT EXPECTED OFF LK
MICHIGAN WITH SW FLOW AS H85 TEMPS ARE AROUND -8C. SHOULD STAY
EAST OF CWA THOUGH AS WINDS ARE FM SW INSTEAD OF SSW OR S. FARTHER
WEST...LK EFFECT SHOULD INCREASE LATER AFTN OVER WESTERN THIRD OF
CWA AS SYNOPTIC LIFT /-DIV-Q AT H7-H5/ FM APPROACHING SHORTWAVE
COMBINES WITH WNW WINDS THROUGH H85 AND TEMPS AT H85 OF -8C YIELDING
DELTA T/S UP TO 12C. INSTABILITY IS MARGINAL AND THUS EXPECT ONLY
MINOR SNOW ACCUMS THROUGH 00Z TUESDAY IN THE WEST.
MONDAY NIGHT INTO TUESDAY HOLDS GREATEST CHANCE FOR MODERATE TO
HEAVY LK EFFECT SNOW SHOWERS. OVERALL EXPECT MOST SNOW TO OCCUR FOR
AREAS FAVORED BY NNW WINDS THROUGH TUESDAY AND THEN SHIFT TO AREAS
FAVORED BY N OR NE WINDS ON TUESDAY NIGHT. UNLIKE THIS LAST EVENT
WHERE SNOWFALL AMOUNTS ENDED UP ON THE LOWER END OF FCST FOR MOST
AREAS...SHORTWAVE/ADDITIONAL SYNOPTIC MOISTURE IS FCST TO IMPACT UPR
LAKES DURING THE TIME OF THE LAKE EFFECT...ESPECIALLY THROUGH
TUESDAY. AT THE LEAST...EXPECT ADVY TYPE SNOWS WILL OCCUR FOR MAINLY
NNW-NW FLOW AREAS MONDAY NIGHT INTO TUESDAY. LACK OF PERSISTENT
UNIDIRECTIONAL FLOW IN LAKE EFFECT CONVECTIVE LAYER WILL LIMIT SNOW
AMOUNTS THOUGH THIS WILL PROBABLY BE OFFSET BY THE SHORTWAVE/DEEPER
MOISTURE. SEEMS LIKE HIGHER TERRAIN FROM IRONWOOD TO ROCKLAND TO
PAINESDALE AND ATLANTIC MINE WILL SEE THE MOST SNOW OVER THE WEST
WHILE FAVORED SNOWBELTS FROM EAST OF MARQUETTE TO NEWBERRY...
INCLUDING MOST OF ALGER COUNTY AND ALONG AND NORTH OF THE SENEY
STRETCH IN SCHOOLCRAFT COUNTY...WILL SEE THE MOST SNOW OVER THE CNTRL
AND EASTERN CWA. UNLIKE THIS LAST EVENT...WINDS SEEM MORE CERTAIN TO
VEER ENOUGH NORTHERLY TO ALLOW FOR LK EFFECT SNOWS TO IMPACT NCNTRL
UPR MICHIGAN /HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES/ LATER
TUESDAY INTO TUESDAY NIGHT AND PERHAPS LINGERING INTO MOST OF
WEDNESDAY. INVERSIONS LOWERING BLO 5KFT AND WINDS BECOMING VARIABLE
WILL DIMINISH SNOW OVER FAR WEST BY WEDNESDAY AFTN. A LIGHT BUT
PERSISTENT N-NE WIND MAY KEEP WEAKENING SNOW SHOWERS GOING THROUGH
MOST OF THE NIGHT BTWN MQT AND MUNISING. LIGHTER WINDS PROBABLY WILL
KEEP MOST OF SNOW SHOWERS RIGHT ALONG IMMEDIATE SHORE WITH SKIES
TRYING TO CLEAR OUT INLAND.
SHORTWAVE AND ARC OF WARM AIR ADVECTION/MOISTURE ADVECTION COULD
SPUR ON BATCH OF LGT SNOW ACROSS MAINLY NORTHERN CWA DURING THE DAY
ON THANKSGIVING. LIMITED MOISTURE WITH PWATS LESS THAN 100 PCT OF
NORMAL AND FOCUS OF STRONGER LIFT FM SHORTWAVE STAYING NORTH OF LK
SUPERIOR SHOULD LIMIT SNOW AMOUNTS. TROUGH SWINGING ACROSS NORTHERN
UPR MICHIGAN MAY KICK OFF SOME SNOW SHOWERS ACROSS KEWEENAW LATER
THURSDAY NIGHT INTO FRIDAY. CONSENSUS GIVES LOW CHANCE POPS BEYOND
FRIDAY WHICH IS FINE GIVEN DIFFERENCES IN TRACK OF SHORTWAVE/SFC
SYSTEM THAT GFS/ECMWF INDICATE MOVES THROUGH THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1210 PM EST SUN NOV 24 2013
VFR CONDITIONS WILL CONTINUE THROUGH MOST OF TONIGHT AT ALL SITES AS
HIGH PRESSURE IS OVER THE AREA. THE PRESSURE GRADIENT OVER THE AREA
WILL TIGHTEN THIS AFTERNOON AND EVENING...SO EXPECT A GUSTY WIND TO
DEVELOP AT THE MORE EXPOSED IWD AND SAW LOCATIONS. MVFR CONDITIONS
WILL RETURN LATE TONIGHT AS LOW LEVEL MOISTURE INCREASES AHEAD OF A
TROUGH APPROACHING THE AREA AT CMX AND IWD AND WILL RETURN MON
MORNING AT SAW. DID PUT IN SOME LLWS AT IWD TONIGHT WITH STRONG
WINDS OFF THE SURFACE. WILL GET QUITE GUSTY AT CMX WITH FAVORABLE
WEST WINDS MONDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EST SUN NOV 24 2013
NW WINDS TO 25 KTS DIMINISH THIS MORNING THEN SHIFT TO THE SW AND
INCREASE TO 30 KTS THIS EVENING. GALES EXPECTED OVR SUPERIOR ZONE
263 TONIGHT DUE TO CHANNELED FLOW BTWN KEWEENAW AND ISLE ROYALE.
WINDS TURN TO NORTHWEST ON MONDAY INTO TUESDAY AND REMAIN UP TO 30
KTS. FREEZING SPRAY MAY OCCUR LATER MONDAY INTO TUESDAY AS ANOTHER
PUSH OF COLDER AIR CROSSES LK SUPERIOR. GALE GUSTS POSSIBLE AS THE
COLDER AIR FIRST ARRIVES. EVENTUALLY WINDS BECOME NORTHERLY TUESDAY
NIGHT INTO WEDNESDAY THEN DIMINISH TO LESS THAN 20 KTS THROUGH THE
REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 8 AM EST MONDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
659 AM EST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST SUN NOV 24 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE NRN GREAT LAKES WITH GRADUALLY RISING HEIGHTS AS THE
TROUGH OVER THE NE CONUS SLIDES TO THE EAST AND MID LEVEL RIDGING
BUILDS TOWARD THE AREA FROM SOUTH CENTRAL CANADA. AT THE SFC...A
RIDGE WAS BUILDING FROM NW WI AND WRN LAKE SUPERIOR INTO FAR W UPPER
MI WHILE LAKE INDUCED TROUGHING PREVAILED THROUGH ERN LAKE SUPERIOR.
SATELLITE AND RADAR INDICATED NW-SE ALIGNED WIND PARALLEL LES BANDS
HAD SHIFTED INTO LOCATIONS E OF MARQUETTE COUNTY. THE BANDS HAD
ALSO BECOME MORE CELLULAR WITH GRADUALLY DECREASING INTENSITY
OVERNIGHT. SFC OBS STILL INDICATED INTO W UPPER MI WITH CMX SHOWING
VSBY IN THE 1-3SM RANGE. HOWEVER...WEBCAMS FROM HOUGHTON AND CALUMET
SHOWED LITTLE SNOW OR VSBY REDUCTION.
THIS MORNING...
DESPITE 850 MB TEMPS AROUND -20C...INVERSION HEIGHTS DROPPING BELOW
5K FT AND VERY DRY AIR UPSTREAM WILL CONTINUE TO LIMIT LES
INTENSITY...ESPECIALLY OVER THE WEST. DIMINISHING WINDS WITH AN
INCREASED LAND BREEZE INFLUENCE AND A BACKING TREND WITH THE
APPROACHING RIDGE WILL RESULT IN A PERIOD OF ENHANCED CONVERGENCE
FROM ERN LAKE SUPERIOR INTO UPPER MI BETWEEN MUNISING AND NEWBERRY
WHERE ADDITIONAL SNOW AMOUNTS IN THE 1 TO 3 INCH RANGE ARE EXPECTED
THROUGH THE MORNING. THE BACKING WINDS SHOULD PUSH THE REMAINING LES
OFFSHORE IN THE AFTERNOON.
THIS AFTERNOON AND TONIGHT...
DEVELOPING WAA WITH STRONG 280K-295K PRES ADV BUT ONLY WEAK TO
MODERATE NET LIFT AHEAD OF A SHRTWV AND SFC LOW MOVING INTO CNTRL
MANITOBA MAY LEAD TO AN AREA OF LIGHT SNOW STREAKING SE INTO THE
NORTH AND EAST PORTIONS OF UPPER MI LATE THIS AFTERNOON AND EVENING.
HOWEVER...WITH THE DRY LOW LEVELS...LITTLE IF ANY SNOW ACCUMULATION
IS EXPECTED WITH ONLY SLIGHT CHANCE POPS INCLUDED. SNOW CHANCES WILL
INCREASE OVERNIGHT AS 700-300 MB QVECTOR CONV AHEAD OF THE SHORTWAVE
MOVES IN BUT SNOW AMOUNTS SHOULD REMAIN LESS THAN A HALF INCH. SW
FLOW LAKE ENHANCEMENT IS LIKELY TO DEVELOP OFF OF LAKE MICHIGAN BUT
THE LOW LEVEL WINDS VEER ENOUGH TO KEEP THE HIGHER SNOW
CHANCES/AMOUNTS TO THE SOUTH AND EAST OF SCHOOLCRAFT AND LUCE
COUNTIES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 440 AM EST SUN NOV 24 2013
NORTHERN STREAM REMAINS ACTIVE THROUGH THE WEEK KEEPING THE COLD
ACROSS THE GREAT LAKES. NEXT CHARGE OF ARCTIC AIR ARRIVES LATER
MONDAY NIGHT INTO TUESDAY. LK EFFECT SNOW INCREASES MONDAY NIGHT
THROUGH TUESDAY NIGHT. AFTER HIGH PRESSURE RIDGE/SUBSIDENCE BRINGS
DIMINISHING TREND TO LK EFFECT LATER WEDNESDAY...ANOTHER SHORTWAVE
DROPPING THROUGH MAY BRING SOME LGT SNOW FOR THANKSGIVING DAY.
AGREEMENT FALLS OFF BY NEXT WEEKEND WITH THE ECMWF KEEPING A NW FLOW
ALOFT ACROSS GREAT LAKES AND BRINGING ANOTHER CLIPPER THROUGH ON
SATURDAY. GFS IS SLOWER AND MORE DEVELOPED BUT FARTHER NORTH WITH
NEXT TROUGH DROPPING THROUGH BY LATE IN THE WEEKEND.
MODELS IN OKAY AGREEMENT THROUGH 12Z TUESDAY THEN THEY BEGIN TO SHOW
DIFFERENCES. OVERALL THOUGH EVEN THE DISAGREEMENT...SPEED OF INITIAL
SHORTWAVE MOVING THROUGH UPR LAKES...DOES NOT HAVE HUGE IMPACTS ON
THE OVERALL THEME OF FORECAST. GFS ENDS UP BEING QUICKER THAN
ECMWF/NAM AND GEM-NH WITH HANDLING OF INITIAL SHORTWAVE. PLAN IS
THAT ON MONDAY MORNING SHORTWAVE WILL BE NORTH OF LK SUPERIOR WITH
TROUGH AXIS DROPPING ACROSS UPR LAKES. SFC LOW/H85 LOW AND SFC
TROUGH SWINGS ACROSS WESTERN UPR MICHIGAN BY MIDDAY AND INTO THE
EASTERN CWA BY EVENING. MAY SEE LGT LK EFFECT WITH MARGINAL TEMPS
AT INVERSION TOP MOST OF THE DAY OVER THE WEST...BETTER CHANCES WILL
BE LATER ON THOUGH. HINT THAT WEAK WAVE IN THE SOUTHERN STREAM
SLIDES WSW-ENE ACROSS MAINLY SOUTHERN SECTIONS OF WESTERN GREAT
LAKES AND INTERACTS WITH H8-H7 FRONTOGENESIS AND RIGHT ENTRANCE
REGION OF JET FM CNTRL GREAT LAKES TO SOUTHERN QUEBEC MONDAY MORNING
THROUGH MID MONDAY AFTN. SOME LGT SYNOPTIC SNOW MAY SCRAPE LK
MICHIGAN ZONES AND FAR EAST. IF THERE IS ENOUGH LOW-LEVEL MOISTURE
TO START THE DAY...COULD EVEN SEE A BIT OF FZDZ ALONG WI BORDER AS
DEEPER MOISTURE HEADS EAST. LAKE ENHANCEMENT EXPECTED OFF LK
MICHIGAN WITH SW FLOW AS H85 TEMPS ARE AROUND -8C. SHOULD STAY
EAST OF CWA THOUGH AS WINDS ARE FM SW INSTEAD OF SSW OR S. FARTHER
WEST...LK EFFECT SHOULD INCREASE LATER AFTN OVER WESTERN THIRD OF
CWA AS SYNOPTIC LIFT /-DIV-Q AT H7-H5/ FM APPROACHING SHORTWAVE
COMBINES WITH WNW WINDS THROUGH H85 AND TEMPS AT H85 OF -8C YIELDING
DELTA T/S UP TO 12C. INSTABILITY IS MARGINAL AND THUS EXPECT ONLY
MINOR SNOW ACCUMS THROUGH 00Z TUESDAY IN THE WEST.
MONDAY NIGHT INTO TUESDAY HOLDS GREATEST CHANCE FOR MODERATE TO
HEAVY LK EFFECT SNOW SHOWERS. OVERALL EXPECT MOST SNOW TO OCCUR FOR
AREAS FAVORED BY NNW WINDS THROUGH TUESDAY AND THEN SHIFT TO AREAS
FAVORED BY N OR NE WINDS ON TUESDAY NIGHT. UNLIKE THIS LAST EVENT
WHERE SNOWFALL AMOUNTS ENDED UP ON THE LOWER END OF FCST FOR MOST
AREAS...SHORTWAVE/ADDITIONAL SYNOPTIC MOISTURE IS FCST TO IMPACT UPR
LAKES DURING THE TIME OF THE LAKE EFFECT...ESPECIALLY THROUGH
TUESDAY. AT THE LEAST...EXPECT ADVY TYPE SNOWS WILL OCCUR FOR MAINLY
NNW-NW FLOW AREAS MONDAY NIGHT INTO TUESDAY. LACK OF PERSISTENT
UNIDIRECTIONAL FLOW IN LAKE EFFECT CONVECTIVE LAYER WILL LIMIT SNOW
AMOUNTS THOUGH THIS WILL PROBABLY BE OFFSET BY THE SHORTWAVE/DEEPER
MOISTURE. SEEMS LIKE HIGHER TERRAIN FROM IRONWOOD TO ROCKLAND TO
PAINESDALE AND ATLANTIC MINE WILL SEE THE MOST SNOW OVER THE WEST
WHILE FAVORED SNOWBELTS FROM EAST OF MARQUETTE TO NEWBERRY...
INCLUDING MOST OF ALGER COUNTY AND ALONG AND NORTH OF THE SENEY
STRETCH IN SCHOOLCRAFT COUNTY...WILL SEE THE MOST SNOW OVER THE CNTRL
AND EASTERN CWA. UNLIKE THIS LAST EVENT...WINDS SEEM MORE CERTAIN TO
VEER ENOUGH NORTHERLY TO ALLOW FOR LK EFFECT SNOWS TO IMPACT NCNTRL
UPR MICHIGAN /HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES/ LATER
TUESDAY INTO TUESDAY NIGHT AND PERHAPS LINGERING INTO MOST OF
WEDNESDAY. INVERSIONS LOWERING BLO 5KFT AND WINDS BECOMING VARIABLE
WILL DIMINISH SNOW OVER FAR WEST BY WEDNESDAY AFTN. A LIGHT BUT
PERSISTENT N-NE WIND MAY KEEP WEAKENING SNOW SHOWERS GOING THROUGH
MOST OF THE NIGHT BTWN MQT AND MUNISING. LIGHTER WINDS PROBABLY WILL
KEEP MOST OF SNOW SHOWERS RIGHT ALONG IMMEDIATE SHORE WITH SKIES
TRYING TO CLEAR OUT INLAND.
SHORTWAVE AND ARC OF WARM AIR ADVECTION/MOISTURE ADVECTION COULD
SPUR ON BATCH OF LGT SNOW ACROSS MAINLY NORTHERN CWA DURING THE DAY
ON THANKSGIVING. LIMITED MOISTURE WITH PWATS LESS THAN 100 PCT OF
NORMAL AND FOCUS OF STRONGER LIFT FM SHORTWAVE STAYING NORTH OF LK
SUPERIOR SHOULD LIMIT SNOW AMOUNTS. TROUGH SWINGING ACROSS NORTHERN
UPR MICHIGAN MAY KICK OFF SOME SNOW SHOWERS ACROSS KEWEENAW LATER
THURSDAY NIGHT INTO FRIDAY. CONSENSUS GIVES LOW CHANCE POPS BEYOND
FRIDAY WHICH IS FINE GIVEN DIFFERENCES IN TRACK OF SHORTWAVE/SFC
SYSTEM THAT GFS/ECMWF INDICATE MOVES THROUGH THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 658 AM EST SUN NOV 24 2013
AS HIGH PRES OVER NRN MO SHIFTS TO THE SE...EXPECT LOW LEVEL
WINDS TO BACK FROM THETHE W-NW EARLY THIS MORNING TO THE SW THIS
AFTERNOON. SINCE THIS FLOW DOWNSLOPES INTO SAW...VFR CONDITIONS
SHOULD PREDOMINATE. THE BEST CHC FOR MORE PERSISTENT MVFR CONDITIONS
WILL BE AT CMX AS THE NW TO W WIND WL UPSLOPE AFTER A LONGER
FETCH/MORE MOISTENING OVER LAKE SUPERIOR. BUT AS THE WIND SHIFTS TO
THE SW...VFR WX WILL TAKE OVER AT CMX EVEN THOUGH SOME FLURRIES/-SN
MAY FALL FROM A THICKENING MID CLOUD DECK RELATED TO THE RETURN OF
WARMER AIR. THE PRES GRADIENT OVER WRN UPPER MI WILL SHARPEN THIS
AFTERNOON AND EVENING...SO EXPECT A GUSTY WIND TO DEVEOP AT THE MORE
EXPOSED IWD AND SAW LOCATIONS. MVFR CONDITIONS MAY RETURN LATE
TONIGHT AS LOW LEVEL MOISTURE INCREASES AHEAD OF A TROUGH
APPROACHING THE AREA.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EST SUN NOV 24 2013
NW WINDS TO 25 KTS DIMINISH THIS MORNING THEN SHIFT TO THE SW AND
INCREASE TO 30 KTS THIS EVENING. GALES EXPECTED OVR SUPERIOR ZONE
263 TONIGHT DUE TO CHANNELED FLOW BTWN KEWEENAW AND ISLE ROYALE.
WINDS TURN TO NORTHWEST ON MONDAY INTO TUESDAY AND REMAIN UP TO 30
KTS. FREEZING SPRAY MAY OCCUR LATER MONDAY INTO TUESDAY AS ANOTHER
PUSH OF COLDER AIR CROSSES LK SUPERIOR. GALE GUSTS POSSIBLE AS THE
COLDER AIR FIRST ARRIVES. EVENTUALLY WINDS BECOME NORTHERLY TUESDAY
NIGHT INTO WEDNESDAY THEN DIMINISH TO LESS THAN 20 KTS THROUGH THE
REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL NOON EST TODAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MIZ001>003.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 8 AM EST MONDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
530 AM EST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 526 AM EST SUN NOV 24 2013
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW
THROUGH THE NRN GREAT LAKES WITH GRADUALLY RISING HEIGHTS AS THE
TROUGH OVER THE NE CONUS SLIDES TO THE EAST AND MID LEVEL RIDGING
BUILDS TOWARD THE AREA FROM SOUTH CENTRAL CANADA. AT THE SFC...A
RIDGE WAS BUILDING FROM NW WI AND WRN LAKE SUPERIOR INTO FAR W UPPER
MI WHILE LAKE INDUCED TROUGHING PREVAILED THROUGH ERN LAKE SUPERIOR.
SATELLITE AND RADAR INDICATED NW-SE ALIGNED WIND PARALLEL LES BANDS
HAD SHIFTED INTO LOCATIONS E OF MARQUETTE COUNTY. THE BANDS HAD
ALSO BECOME MORE CELLULAR WITH GRADUALLY DECREASING INTENSITY
OVERNIGHT. SFC OBS STILL INDICATED INTO W UPPER MI WITH CMX SHOWING
VSBY IN THE 1-3SM RANGE. HOWEVER...WEBCAMS FROM HOUGHTON AND CALUMET
SHOWED LITTLE SNOW OR VSBY REDUCTION.
THIS MORNING...
DESPITE 850 MB TEMPS AROUND -20C...INVERSION HEIGHTS DROPPING BELOW
5K FT AND VERY DRY AIR UPSTREAM WILL CONTINUE TO LIMIT LES
INTENSITY...ESPECIALLY OVER THE WEST. DIMINISHING WINDS WITH AN
INCREASED LAND BREEZE INFLUENCE AND A BACKING TREND WITH THE
APPROACHING RIDGE WILL RESULT IN A PERIOD OF ENHANCED CONVERGENCE
FROM ERN LAKE SUPERIOR INTO UPPER MI BETWEEN MUNISING AND NEWBERRY
WHERE ADDITIONAL SNOW AMOUNTS IN THE 1 TO 3 INCH RANGE ARE EXPECTED
THROUGH THE MORNING. THE BACKING WINDS SHOULD PUSH THE REMAINING LES
OFFSHORE IN THE AFTERNOON.
THIS AFTERNOON AND TONIGHT...
DEVELOPING WAA WITH STRONG 280K-295K PRES ADV BUT ONLY WEAK TO
MODERATE NET LIFT AHEAD OF A SHRTWV AND SFC LOW MOVING INTO CNTRL
MANITOBA MAY LEAD TO AN AREA OF LIGHT SNOW STREAKING SE INTO THE
NORTH AND EAST PORTIONS OF UPPER MI LATE THIS AFTERNOON AND EVENING.
HOWEVER...WITH THE DRY LOW LEVELS...LITTLE IF ANY SNOW ACCUMULATION
IS EXPECTED WITH ONLY SLIGHT CHANCE POPS INCLUDED. SNOW CHANCES WILL
INCREASE OVERNIGHT AS 700-300 MB QVECTOR CONV AHEAD OF THE SHORTWAVE
MOVES IN BUT SNOW AMOUNTS SHOULD REMAIN LESS THAN A HALF INCH. SW
FLOW LAKE ENHANCEMENT IS LIKELY TO DEVELOP OFF OF LAKE MICHIGAN BUT
THE LOW LEVEL WINDS VEER ENOUGH TO KEEP THE HIGHER SNOW
CHANCES/AMOUNTS TO THE SOUTH AND EAST OF SCHOOLCRAFT AND LUCE
COUNTIES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 440 AM EST SUN NOV 24 2013
NORTHERN STREAM REMAINS ACTIVE THROUGH THE WEEK KEEPING THE COLD
ACROSS THE GREAT LAKES. NEXT CHARGE OF ARCTIC AIR ARRIVES LATER
MONDAY NIGHT INTO TUESDAY. LK EFFECT SNOW INCREASES MONDAY NIGHT
THROUGH TUESDAY NIGHT. AFTER HIGH PRESSURE RIDGE/SUBSIDENCE BRINGS
DIMINISHING TREND TO LK EFFECT LATER WEDNESDAY...ANOTHER SHORTWAVE
DROPPING THROUGH MAY BRING SOME LGT SNOW FOR THANKSGIVING DAY.
AGREEMENT FALLS OFF BY NEXT WEEKEND WITH THE ECMWF KEEPING A NW FLOW
ALOFT ACROSS GREAT LAKES AND BRINGING ANOTHER CLIPPER THROUGH ON
SATURDAY. GFS IS SLOWER AND MORE DEVELOPED BUT FARTHER NORTH WITH
NEXT TROUGH DROPPING THROUGH BY LATE IN THE WEEKEND.
MODELS IN OKAY AGREEMENT THROUGH 12Z TUESDAY THEN THEY BEGIN TO SHOW
DIFFERENCES. OVERALL THOUGH EVEN THE DISAGREEMENT...SPEED OF INITIAL
SHORTWAVE MOVING THROUGH UPR LAKES...DOES NOT HAVE HUGE IMPACTS ON
THE OVERALL THEME OF FORECAST. GFS ENDS UP BEING QUICKER THAN
ECMWF/NAM AND GEM-NH WITH HANDLING OF INITIAL SHORTWAVE. PLAN IS
THAT ON MONDAY MORNING SHORTWAVE WILL BE NORTH OF LK SUPERIOR WITH
TROUGH AXIS DROPPING ACROSS UPR LAKES. SFC LOW/H85 LOW AND SFC
TROUGH SWINGS ACROSS WESTERN UPR MICHIGAN BY MIDDAY AND INTO THE
EASTERN CWA BY EVENING. MAY SEE LGT LK EFFECT WITH MARGINAL TEMPS
AT INVERSION TOP MOST OF THE DAY OVER THE WEST...BETTER CHANCES WILL
BE LATER ON THOUGH. HINT THAT WEAK WAVE IN THE SOUTHERN STREAM
SLIDES WSW-ENE ACROSS MAINLY SOUTHERN SECTIONS OF WESTERN GREAT
LAKES AND INTERACTS WITH H8-H7 FRONTOGENESIS AND RIGHT ENTRANCE
REGION OF JET FM CNTRL GREAT LAKES TO SOUTHERN QUEBEC MONDAY MORNING
THROUGH MID MONDAY AFTN. SOME LGT SYNOPTIC SNOW MAY SCRAPE LK
MICHIGAN ZONES AND FAR EAST. IF THERE IS ENOUGH LOW-LEVEL MOISTURE
TO START THE DAY...COULD EVEN SEE A BIT OF FZDZ ALONG WI BORDER AS
DEEPER MOISTURE HEADS EAST. LAKE ENHANCEMENT EXPECTED OFF LK
MICHIGAN WITH SW FLOW AS H85 TEMPS ARE AROUND -8C. SHOULD STAY
EAST OF CWA THOUGH AS WINDS ARE FM SW INSTEAD OF SSW OR S. FARTHER
WEST...LK EFFECT SHOULD INCREASE LATER AFTN OVER WESTERN THIRD OF
CWA AS SYNOPTIC LIFT /-DIV-Q AT H7-H5/ FM APPROACHING SHORTWAVE
COMBINES WITH WNW WINDS THROUGH H85 AND TEMPS AT H85 OF -8C YIELDING
DELTA T/S UP TO 12C. INSTABILITY IS MARGINAL AND THUS EXPECT ONLY
MINOR SNOW ACCUMS THROUGH 00Z TUESDAY IN THE WEST.
MONDAY NIGHT INTO TUESDAY HOLDS GREATEST CHANCE FOR MODERATE TO
HEAVY LK EFFECT SNOW SHOWERS. OVERALL EXPECT MOST SNOW TO OCCUR FOR
AREAS FAVORED BY NNW WINDS THROUGH TUESDAY AND THEN SHIFT TO AREAS
FAVORED BY N OR NE WINDS ON TUESDAY NIGHT. UNLIKE THIS LAST EVENT
WHERE SNOWFALL AMOUNTS ENDED UP ON THE LOWER END OF FCST FOR MOST
AREAS...SHORTWAVE/ADDITIONAL SYNOPTIC MOISTURE IS FCST TO IMPACT UPR
LAKES DURING THE TIME OF THE LAKE EFFECT...ESPECIALLY THROUGH
TUESDAY. AT THE LEAST...EXPECT ADVY TYPE SNOWS WILL OCCUR FOR MAINLY
NNW-NW FLOW AREAS MONDAY NIGHT INTO TUESDAY. LACK OF PERSISTENT
UNIDIRECTIONAL FLOW IN LAKE EFFECT CONVECTIVE LAYER WILL LIMIT SNOW
AMOUNTS THOUGH THIS WILL PROBABLY BE OFFSET BY THE SHORTWAVE/DEEPER
MOISTURE. SEEMS LIKE HIGHER TERRAIN FROM IRONWOOD TO ROCKLAND TO
PAINESDALE AND ATLANTIC MINE WILL SEE THE MOST SNOW OVER THE WEST
WHILE FAVORED SNOWBELTS FROM EAST OF MARQUETTE TO NEWBERRY...
INCLUDING MOST OF ALGER COUNTY AND ALONG AND NORTH OF THE SENEY
STRETCH IN SCHOOLCRAFT COUNTY...WILL SEE THE MOST SNOW OVER THE CNTRL
AND EASTERN CWA. UNLIKE THIS LAST EVENT...WINDS SEEM MORE CERTAIN TO
VEER ENOUGH NORTHERLY TO ALLOW FOR LK EFFECT SNOWS TO IMPACT NCNTRL
UPR MICHIGAN /HIGHER TERRAIN OF BARAGA AND MARQUETTE COUNTIES/ LATER
TUESDAY INTO TUESDAY NIGHT AND PERHAPS LINGERING INTO MOST OF
WEDNESDAY. INVERSIONS LOWERING BLO 5KFT AND WINDS BECOMING VARIABLE
WILL DIMINISH SNOW OVER FAR WEST BY WEDNESDAY AFTN. A LIGHT BUT
PERSISTENT N-NE WIND MAY KEEP WEAKENING SNOW SHOWERS GOING THROUGH
MOST OF THE NIGHT BTWN MQT AND MUNISING. LIGHTER WINDS PROBABLY WILL
KEEP MOST OF SNOW SHOWERS RIGHT ALONG IMMEDIATE SHORE WITH SKIES
TRYING TO CLEAR OUT INLAND.
SHORTWAVE AND ARC OF WARM AIR ADVECTION/MOISTURE ADVECTION COULD
SPUR ON BATCH OF LGT SNOW ACROSS MAINLY NORTHERN CWA DURING THE DAY
ON THANKSGIVING. LIMITED MOISTURE WITH PWATS LESS THAN 100 PCT OF
NORMAL AND FOCUS OF STRONGER LIFT FM SHORTWAVE STAYING NORTH OF LK
SUPERIOR SHOULD LIMIT SNOW AMOUNTS. TROUGH SWINGING ACROSS NORTHERN
UPR MICHIGAN MAY KICK OFF SOME SNOW SHOWERS ACROSS KEWEENAW LATER
THURSDAY NIGHT INTO FRIDAY. CONSENSUS GIVES LOW CHANCE POPS BEYOND
FRIDAY WHICH IS FINE GIVEN DIFFERENCES IN TRACK OF SHORTWAVE/SFC
SYSTEM THAT GFS/ECMWF INDICATE MOVES THROUGH THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1239 AM EST SUN NOV 24 2013
AS HI PRES OVER IOWA SHIFTS STEADILY TO THE SE DURING THIS PERIOD...
EXPECT LLVL WINDS TO BACK FM THE W-NW EARLY THIS MRNG TO THE SW BY
THIS AFTN. ALTHOUGH SOME LINGERING LES MAY BRING MVFR CONDITIONS TO
IWD EARLY IN THE PERIOD UNDER LINGERING WNW FLOW...MINIMAL LK SUP
MOISTENING OF THE DRY ARCTIC AIRMASS WL ENSURE PREDOMINANT VFR
CONDITIONS FOR THAT LOCATION. SINCE THIS FLOW DOWNSLOPES INTO
SAW...VFR CONDITIONS SHOULD PREDOMINATE THERE AS WELL. THE BEST CHC
FOR MORE PERSISTENT MVFR TO PERHAPS IFR CONDITIONS WL BE AT CMX THRU
SUNRISE AS THE NW TO W WIND WL UPSLOPE AFT A LONGER FETCH/MORE
MOISTENING OVER LK SUP. BUT AS THE WIND SHIFTS TO THE SW ON SUN...
VFR WX WL THE RULE AT CMX AS WELL EVEN THOUGH SOME FLURRIES/-SN MAY
FALL FM A THICKENING MID CLD DECK RELATED TO THE RETURN OF WARMER
AIR. THE PRES GRADIENT OVER WRN UPR MI WL SHARPEN ON SUN AFTN/
EVNG...SO EXPECT A GUSTY WIND TO DVLP AT THE MORE EXPOSED IWD AND
SAW LOCATIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 AM EST SUN NOV 24 2013
NW WINDS TO 25 KTS DIMINISH THIS MORNING THEN SHIFT TO THE SW AND
INCREASE TO 30 KTS THIS EVENING. GALES EXPECTED OVR SUPERIOR ZONE
263 TONIGHT DUE TO CHANNELED FLOW BTWN KEWEENAW AND ISLE ROYALE.
WINDS TURN TO NORTHWEST ON MONDAY INTO TUESDAY AND REMAIN UP TO 30
KTS. FREEZING SPRAY MAY OCCUR LATER MONDAY INTO TUESDAY AS ANOTHER
PUSH OF COLDER AIR CROSSES LK SUPERIOR. GALE GUSTS POSSIBLE AS THE
COLDER AIR FIRST ARRIVES. EVENTUALLY WINDS BECOME NORTHERLY TUESDAY
NIGHT INTO WEDNESDAY THEN DIMINISH TO LESS THAN 20 KTS THROUGH THE
REST OF THE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL NOON EST TODAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR
MIZ001>003.
LAKE SUPERIOR...
GALE WARNING FROM 5 PM THIS AFTERNOON TO 8 AM EST MONDAY FOR
LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS DULUTH MN
903 AM CST SUN NOV 24 2013
.UPDATE...
ISSUED AT 902 AM CST SUN NOV 24 2013
MADE SOME ADJUSTMENTS TO REMOVE THE MENTION OF FLURRIES THIS
AFTERNOON. RH IN THE 1000MB-500MB RANGE IS LESS THAN 50 PERCENT
IN ALL AREAS EXCEPT WHERE THERE IS A MENTION OF ISOLD/SCT SNOW
SHOWERS NEAR THE INTERNATIONAL BORDER AND OVER THE ARROWHEAD. REST
OF THE FORECAST ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 400 AM CST SUN NOV 24 2013
A STRONG PUSH OF WARM AIR ADVECTION WILL OVERTAKE THE REGION TODAY
AS A LOW LEVEL TROUGH SWEEPS ACROSS THE DAKOTAS. LATEST MODELS IN
GOOD AGREEMENT THAT H85 TEMPS INCREASE ON THE ODER OF >10 C THROUGH
THE DAY AS A LOW LEVEL JET STREAK OF 40-50 KT WLY WINDS ADVECT
ACROSS CENTRAL MN. AFTERNOON TEMPERATURES WILL RETURN TO MORE
SEASONAL VALUES TODAY...IN THE MID TO UPPER 20S.
A FAST MOVING VORT MAX WILL SLIDE ALONG THE INTERNATIONAL BORDER
THIS MORNING...REACHING THE MN ARROWHEAD ZONES THIS AFTERNOON. THE
COMBINATION OF MID LEVEL OMEGA IN THE DENDRITIC GROWTH ZONE...AND
LAKE EFFECT/ENHANCEMENT FROM THE STRONG S/SW BOUNDARY LAYER WINDS
WILL PRODUCE A QUICK INCH OR SO ALONG THE NORTH SHORE OF LAKE
SUPERIOR TODAY. THE MAIN CORRIDOR OF SNOW ACCUMULATION WILL BE
ALONG HIGHWAY 61 FROM SILVER BAY...TO LUTSEN...GRAND MARAIS AND
GRAND PORTAGE. LOCATIONS IN THE ELEVATED TERRAIN OF COOK
COUNTY...A FEW MILES INLAND FROM LAKE SUPERIOR...CAN EXPECT
LOCALLY HIGHER AMOUNTS AROUND 2 INCHES DUE TO ENHANCED OROGRAPHIC
LIFT.
FOCUS TURNS TO THREAT FOR FREEZING DRIZZLE OVERNIGHT AHEAD OF
FRONTAL PASSAGE. LATEST NAM BUFR SOUNDINGS ACROSS MUCH THE
NORTHLAND SHOW PROFILES WITH A DEEP SATURATED LAYER...AND CLOUD
TOP TEMPERATURES IN THE SINGLE DIGITS BELOW ZERO LATE THIS EVENING
AS THE REGION REMAINS IN THE WARM SECTOR AHEAD OF THE TROUGH. THE
BEST FORCING OVERNIGHT...AND MAIN THREAT FOR FZDZ...WILL BE OVER
THE NRN WIS/EC MN AREAS WHERE H70-H85 OMEGA AND UPPER LVL JET
DIVERGENCE WILL BE GREATEST. THERE IS HIGHER UNCERTAINTY IN THE
PROBABILITY OF FZDZ OVER THE MN ZONES TONIGHT AS DRIER AIR RETURNS
ONCE THE TROUGH PASSES.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN NOV 24 2013
THE UPPER PATTERN WILL START OUT WITH A RIDGE EXTENDING ALONG THE
WESTERN CONUS COAST INTO BC...WITH A TROUGH COVER MUCH OF THE
CENTRAL CONUS. THE NORTHLAND WILL BE IN NORTHWEST FLOW ALOFT. THE
PATTERN WILL CHANGE LATE IN THE PERIOD AS AN UPPER LOW SETTLES IN
JUST OFF THE SOUTHWEST CALIFORNIA COAST BY SATURDAY. OUR FLOW WILL
TURN MORE WNW. SEVERAL SHORTWAVES WILL BE MOVING THROUGH THE
NORTHWEST FLOW BRINGING A PERIOD OR TWO OF LIGHT SNOW/FLURRIES TO
THE NORTHLAND. A SIGNIFICANT LAKE EFFECT SNOW EVENT WILL BE POSSIBLE
TUESDAY INTO WEDNESDAY ALONG PORTIONS OF THE SOUTH SHORE.
TIMING DIFFERENCES AMONG THE MODELS SHOW UP EARLY IN THE
PERIOD...WITH THE GFS A BIT FASTER WITH A SHORTWAVE MONDAY NIGHT AND
TUESDAY AS WELL BEING FASTER PUSHING AN AREA OF HIGH PRESSURE
THROUGH THE AREA TUESDAY NIGHT/WEDNESDAY. WE FOLLOWED CLOSER TO A
BLEND OF THE ECMWF/NAM/GEM ON TIMING THESE FEATURES WHICH WERE ALL
SLOWER THAN THE GFS. SNOW SHOWERS WILL BE POSSIBLE MONDAY NIGHT AS
THE SHORTWAVE MOVES THROUGH AND ANOTHER SHOT OF COLDER AIR PUSHES
THROUGH. SNOW ACCUMULATIONS WILL BE LIGHT...WITH SOME AREAS PERHAPS
GETTING AROUND AN INCH...MAINLY FAR NORTH. LOW LEVEL WINDS LOOK TOO
WEST OF NORTH MONDAY NIGHT FOR LAKE EFFECT SNOW DESPITE THE COLD
AIR...-15C TO -17C OVER LAKE SUPERIOR AT 850MB.
EMPHASIS WILL SHIFT TO LAKE EFFECT SNOW ALONG THE SNOWBELT REGION OF
ASHLAND/IRON COUNTIES TUESDAY INTO WEDNESDAY AS LITTLE SNOW WILL
FALL OUTSIDE OF THIS AREA. WINDS VEER TO NORTHERLY TUESDAY WITH
850MB TEMPS AROUND -18C TO -20C. A LONG FETCH/LOW
STABILITY/INVERSION HEIGHTS WILL BE QUITE FAVORABLE FOR LES.
MOISTURE DEPTH ALSO LOOKS BETTER WITH THIS EVENT VERSUS THE RECENT
LES FRIDAY NIGHT/SATURDAY. THE LOW LEVEL WINDS ARE FORECAST TO VEER
TO MORE NORTHEAST TUESDAY NIGHT AND CONTINUE TO BE NNE ON WEDNESDAY.
THIS SHOULD SHIFT THE SNOW BANDS FURTHER WEST MORE INTO NORTHWEST
IRON INTO ASHLAND COUNTIES. CONDITIONS WILL GRADUALLY BECOME LESS
FAVORABLE FOR LES LATE TUESDAY NIGHT INTO WEDNESDAY AS BOTH THE
NAM AND ECMWF SHOW DRIER AIR MOVING OVER LAKE SUPERIOR ALONG WITH A
RIDGE OF HIGH PRESSURE. THE FETCH WILL BE MORE FAVORABLE THOUGH WITH
LONGER RESIDENCE TIME OVER THE LAKE. THE TUESDAY-WEDNESDAY MORNING
PERIOD BEARS A CLOSE WATCH AS A HEADLINE FOR SIGNIFICANT SNOW WILL
LIKELY BE NEEDED IF THESE FORECAST CONDITIONS CONTINUE.
A SHORTWAVE WEDNESDAY NIGHT/THURSDAY MAY BRING SOME LIGHT SNOW TO
NORTHERN PORTIONS OF THE REGION...WITH A BRIEF PERIOD OF LAKE
ENHANCED SNOW POSSIBLE ALONG COASTAL COOK COUNTY. ANOTHER SYSTEM
LATE IN THE PERIOD WILL BRING A CHANCE FOR SNOW...BUT SIGNIFICANT
SNOWFALL LOOKS UNLIKELY AT THIS POINT OUTSIDE OF THE LES CHANCES
MENTIONED ABOVE.
EXPECT HIGH TEMPERATURES TUESDAY TO BE IN THE TEENS TO AROUND 20
WITH THEM ONLY MODERATING SLIGHTLY THROUGH THE PERIOD TO 25
TO 30 BY NEXT SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 540 AM CST SUN NOV 24 2013
STRONG WAA OVER THE NORTHLAND WILL CAUSE MID-HIGH LEVEL CLOUDS TO
MOVE THROUGH THE AREA TODAY...WITH A CHANCE FOR LIGHT SNOW AND LOWER
CEILINGS ACROSS NORTHERN MINNESOTA. A COLD FRONT WILL THEN MOVE
INTO THE AREA TONIGHT. SOUNDINGS SUGGEST IF SOME PRECIPITATION
DOES OCCUR TONIGHT...FREEZING DRIZZLE WILL BE POSSIBLE. AT THIS
TIME...CONFIDENCE IN PRECIP COVERAGE IS LOW AND WE MENTION SOME
LIGHT SNOW THIS MORNING AT KINL...AND SOME FZDZ AT KHIB/KDLH/KHYR
LATER TONIGHT. KHYR HAS THE BEST CHANCE AT SEEING THE FZDZ. CEILINGS
TONIGHT WILL ALSO BE A QUESTION MARK...WITH THE RAP/NAM SHOWING
LOWER CEILINGS MOVING IN OR DEVELOPING. THE RAP HAS SLOWED THE
MOVEMENT OF LOWER CEILINGS ACROSS THE FAR NORTH WITH IT`S MOST
RECENT UPDATE. WE FEEL MOST CONFIDENT KINL AND KHYR WILL HAVE MVFR
CEILINGS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 20 31 11 / 10 20 10 20
INL 26 20 25 8 / 20 20 30 40
BRD 27 24 31 12 / 0 10 10 20
HYR 24 20 33 16 / 10 20 20 20
ASX 27 23 34 17 / 10 20 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM NOON TODAY TO 10 AM CST WEDNESDAY FOR
LSZ121-146>148.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 4 PM CST MONDAY FOR
LSZ140>145.
&&
$$
UPDATE...GSF
SHORT TERM...GRANING
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
547 AM CST SUN NOV 24 2013
.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 400 AM CST SUN NOV 24 2013
A STRONG PUSH OF WARM AIR ADVECTION WILL OVERTAKE THE REGION TODAY
AS A LOW LEVEL TROUGH SWEEPS ACROSS THE DAKOTAS. LATEST MODELS IN
GOOD AGREEMENT THAT H85 TEMPS INCREASE ON THE ODER OF >10 C THROUGH
THE DAY AS A LOW LEVEL JET STREAK OF 40-50 KT WRLY WINDS ADVECT
ACROSS CENTRAL MN. AFTERNOON TEMPERATURES WILL RETURN TO MORE
SEASONAL VALUES TODAY...IN THE MID TO UPPER 20S.
A FAST MOVING VORT MAX WILL SLIDE ALONG THE INTERNATIONAL BORDER
THIS MORNING...REACHING THE MN ARROWHEAD ZONES THIS AFTERNOON. THE
COMBINATION OF MID LEVEL OMEGA IN THE DENDRITIC GROWTH ZONE...AND
LAKE EFFECT/ENHANCEMENT FROM THE STRONG S/SW BOUNDARY LAYER WINDS
WILL PRODUCE A QUICK INCH OR SO ALONG THE NORTH SHORE OF LAKE
SUPERIOR TODAY. THE MAIN CORRIDOR OF SNOW ACCUMULATION WILL BE
ALONG HIGHWAY 61 FROM SILVER BAY...TO LUTSEN...GRAND MARAIS AND
GRAND PORTAGE. LOCATIONS IN THE ELEVATED TERRAIN OF COOK
COUNTY...A FEW MILES INLAND FROM LAKE SUPERIOR...CAN EXPECT
LOCALLY HIGHER AMOUNTS AROUND 2 INCHES DUE TO ENHANCED OROGRAPHIC
LIFT.
FOCUS TURNS TO THREAT FOR FREEZING DRIZZLE OVERNIGHT AHEAD OF
FRONTAL PASSAGE. LATEST NAM BUFR SOUNDINGS ACROSS MUCH THE
NORTHLAND SHOW PROFILES WITH A DEEP SATURATED LAYER...AND CLOUD
TOP TEMPERATURES IN THE SINGLE DIGITS BELOW ZERO LATE THIS EVENING
AS THE REGION REMAINS IN THE WARM SECTOR AHEAD OF THE TROUGH. THE
BEST FORCING OVERNIGHT...AND MAIN THREAT FOR FZDZ...WILL BE OVER
THE NRN WIS/EC MN AREAS WHERE H70-H85 OMEGA AND UPPER LVL JET
DIVERGENCE WILL BE GREATEST. THERE IS HIGHER UNCERTAINTY IN THE
PROBABILITY OF FZDZ OVER THE MN ZONES TONIGHT AS DRIER AIR RETURNS
ONCE THE TROUGH PASSES.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 400 AM CST SUN NOV 24 2013
THE UPPER PATTERN WILL START OUT WITH A RIDGE EXTENDING ALONG THE
WESTERN CONUS COAST INTO BC...WITH A TROUGH COVER MUCH OF THE
CENTRAL CONUS. THE NORTHLAND WILL BE IN NORTHWEST FLOW ALOFT. THE
PATTERN WILL CHANGE LATE IN THE PERIOD AS AN UPPER LOW SETTLES IN
JUST OFF THE SOUTHWEST CALIFORNIA COAST BY SATURDAY. OUR FLOW WILL
TURN MORE WNW. SEVERAL SHORTWAVES WILL BE MOVING THROUGH THE
NORTHWEST FLOW BRINGING A PERIOD OR TWO OF LIGHT SNOW/FLURRIES TO
THE NORTHLAND. A SIGNIFICANT LAKE EFFECT SNOW EVENT WILL BE POSSIBLE
TUESDAY INTO WEDNESDAY ALONG PORTIONS OF THE SOUTH SHORE.
TIMING DIFFERENCES AMONG THE MODELS SHOW UP EARLY IN THE
PERIOD...WITH THE GFS A BIT FASTER WITH A SHORTWAVE MONDAY NIGHT AND
TUESDAY AS WELL BEING FASTER PUSHING AN AREA OF HIGH PRESSURE
THROUGH THE AREA TUESDAY NIGHT/WEDNESDAY. WE FOLLOWED CLOSER TO A
BLEND OF THE ECMWF/NAM/GEM ON TIMING THESE FEATURES WHICH WERE ALL
SLOWER THAN THE GFS. SNOW SHOWERS WILL BE POSSIBLE MONDAY NIGHT AS
THE SHORTWAVE MOVES THROUGH AND ANOTHER SHOT OF COLDER AIR PUSHES
THROUGH. SNOW ACCUMULATIONS WILL BE LIGHT...WITH SOME AREAS PERHAPS
GETTING AROUND AN INCH...MAINLY FAR NORTH. LOW LEVEL WINDS LOOK TOO
WEST OF NORTH MONDAY NIGHT FOR LAKE EFFECT SNOW DESPITE THE COLD
AIR...-15C TO -17C OVER LAKE SUPERIOR AT 850MB.
EMPHASIS WILL SHIFT TO LAKE EFFECT SNOW ALONG THE SNOWBELT REGION OF
ASHLAND/IRON COUNTIES TUESDAY INTO WEDNESDAY AS LITTLE SNOW WILL
FALL OUTSIDE OF THIS AREA. WINDS VEER TO NORTHERLY TUESDAY WITH
850MB TEMPS AROUND -18C TO -20C. A LONG FETCH/LOW
STABILITY/INVERSION HEIGHTS WILL BE QUITE FAVORABLE FOR LES.
MOISTURE DEPTH ALSO LOOKS BETTER WITH THIS EVENT VERSUS THE RECENT
LES FRIDAY NIGHT/SATURDAY. THE LOW LEVEL WINDS ARE FORECAST TO VEER
TO MORE NORTHEAST TUESDAY NIGHT AND CONTINUE TO BE NNE ON WEDNESDAY.
THIS SHOULD SHIFT THE SNOWBANDS FURTHER WEST MORE INTO NORTHWEST
IRON INTO ASHLAND COUNTIES. CONDITIONS WILL GRADUALLY BECOME LESS
FAVORABLE FOR LES LATE TUESDAY NIGHT INTO WEDNESDAY AS BOTH THE
NAM AND ECMWF SHOW DRIER AIR MOVING OVER LAKE SUPERIOR ALONG WITH A
RIDGE OF HIGH PRESSURE. THE FETCH WILL BE MORE FAVORABLE THOUGH WITH
LONGER RESIDENCE TIME OVER THE LAKE. THE TUESDAY-WEDNESDAY MORNING
PERIOD BEARS A CLOSE WATCH AS A HEADLINE FOR SIGNIFICANT SNOW WILL
LIKELY BE NEEDED IF THESE FORECAST CONDITIONS CONTINUE.
A SHORTWAVE WEDNESDAY NIGHT/THURSDAY MAY BRING SOME LIGHT SNOW TO
NORTHERN PORTIONS OF THE REGION...WITH A BRIEF PERIOD OF LAKE
ENHANCED SNOW POSSIBLE ALONG COASTAL COOK COUNTY. ANOTHER SYSTEM
LATE IN THE PERIOD WILL BRING A CHANCE FOR SNOW...BUT SIGNIFICANT
SNOWFALL LOOKS UNLIKELY AT THIS POINT OUTSIDE OF THE LES CHANCES
MENTIONED ABOVE.
EXPECT HIGH TEMPERATURES TUESDAY TO BE IN THE TEENS TO AROUND 20
WITH THEM ONLY MODERATING SLIGHTLY THROUGH THE PERIOD TO 25
TO 30 BY NEXT SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 540 AM CST SUN NOV 24 2013
STRONG WAA OVER THE NORTHLAND WILL CAUSE MID-HIGH LEVEL CLOUDS TO
MOVE THROUGH THE AREA TODAY...WITH A CHANCE FOR LIGHT SNOW AND LOWER
CEILINGS ACROSS NORTHERN MINNESOTA. A COLD FRONT WILL THEN MOVE
INTO THE AREA TONIGHT. SOUNDINGS SUGGEST IF SOME PRECIPITATION
DOES OCCURN TONIGHT...FREEZING DRIZZLE WILL BE POSSIBLE. AT THIS
TIME...CONFIDENCE IN PRECIP COVERAGE IS LOW AND WE MENTION SOME
LIGHT SNOW THIS MORNING AT KINL...AND SOME FZDZ AT KHIB/KDLH/KHYR
LATER TONIGHT. KHYR HAS THE BEST CHANCE AT SEEING THE FZDZ. CEILINGS
TONIGHT WILL ALSO BE A QUESTION MARK...WITH THE RAP/NAM SHOWING
LOWER CEILINGS MOVING IN OR DEVELOPING. THE RAP HAS SLOWED THE
MOVEMENT OF LOWER CEILINGS ACROSS THE FAR NORTH WITH IT`S MOST
RECENT UPDATE. WE FEEL MOST CONFIDENT KINL AND KHYR WILL HAVE MVFR
CEILINGS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 26 20 31 11 / 10 20 10 20
INL 26 20 25 8 / 20 20 30 40
BRD 27 24 31 12 / 0 10 10 20
HYR 24 20 33 16 / 10 20 20 20
ASX 27 23 34 17 / 10 20 20 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY FROM NOON TODAY TO 10 AM CST WEDNESDAY FOR
LSZ121-146>148.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 4 PM CST MONDAY FOR
LSZ140>145.
&&
$$
SHORT TERM...GRANING
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
236 PM CST SUN NOV 24 2013
.SYNOPSIS...
ISSUED AT 235 PM CST SUN NOV 24 2013
AN UPPER LOW SPUN OVER THE FOUR CORNERS ON SUNDAY AFTERNOON...WHICH
PUSHED SOME MID AND HIGH LEVEL CLOUDS INTO SOUTHERN NEBRASKA. WITH
THE UPPER LOW TO THE SOUTH...WESTERLY FLOW ALOFT HAS ALLOWED FOR A
THERMAL RIDGE TO MOVE INTO THE NORTHERN PLAINS TODAY WHERE 850MB
TEMPERATURES WERE GENERALLY 5C TO 10C AS OF 12Z THIS MORNING
COMPARED TO 0C TO-5C ACROSS NEBRASKA. LOOKING AT WATER VAPOR...COULD
MAKE OUT THE NEXT LOW PRESSURE SYSTEM IN LINE IN THE NORTHWEST FLOW
OVER SASKATCHEWAN...WITH ANOTHER BATCH OF COLD ARCTIC AIR BEHIND IT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 235 PM CST SUN NOV 24 2013
THE UPPER LEVEL LOW OVER THE FOUR CORNERS IS EXPECTED TO START
GETTING INFLUENCED BY THE MEAN NORTHWEST FLOW AND START TO PUSH INTO
TEXAS BY THE END OF THE DAY MONDAY. THIS SHOULD ALLOW FOR THE MID
AND HIGH CLOUDS THAT HAVE BEEN SPINNING AROUND THIS SYSTEM INTO THE
SOUTHERN PART OF THE FORECAST AREA FOR THE PAST SEVERAL DAYS TO GET
PULLED SOUTHWARD AND AWAY FROM THE LOCAL AREA TONIGHT AND MONDAY
MORNING. IT WILL ALSO ALLOW FOR SOME OF THE COLDER AIR ASSOCIATED
WITH THAT SYSTEM TO GET PUSHED AWAY FROM THE AREA. MEANWHILE...THE
LOW PRESSURE SYSTEM OVER SASKATCHEWAN WILL MOVE INTO ONTARIO WHICH
WILL DRAG A COLD FRONT ACROSS NEBRASKA TONIGHT AND MONDAY MORNING.
ALTHOUGH TEMPERATURES BEHIND THE FRONT WON/T BE MUCH COLDER FOR THE
LOCAL AREA. WINDS WILL SWITCH TO THE NORTH-NORTHWEST BEHIND THE
FRONT. FORECAST SOUNDINGS ARE SHOWING MINIMAL MIXING MONDAY
AFTERNOON...BUT WINDS JUST ABOVE THE SURFACE ARE ABOUT 25KTS SO
COULD SEE SOME 20KT WINDS AT GROUND LEVEL DURING THE AFTERNOON.
ONE CONCERN WITH THE FORECAST WILL BE THE POTENTIAL FOR THE
DEVELOPMENT OF SHALLOW STRATUS THIS EVENING AND TONIGHT FROM
SOUTHWEST INTO CENTRAL NEBRASKA. LOW LEVEL MOISTURE ADVECTION IS
BEING INDICATED INTO THE AREA AHEAD OF THE FRONT BY SEVERAL FORECAST
MODELS...WITH THE NAM BEING THE MOST ROBUST SPREADING STRATUS ACROSS
THE ENTIRE FORECAST AREA. DISCOUNTING THAT MODEL AND LOOKING CLOSER
TO THE RAP WHICH HAS BEEN HOLDING OFF THE LOW LEVEL MOISTURE FROM
MOVING INTO NEBRASKA THROUGH THE DAY TODAY. ALTHOUGH IT HAS KEPT
THIS MOISTURE SOUTH TODAY...IT DOES CONTINUE TO PUSH IT INTO
NEBRASKA THIS EVENING...WITH CLOUDS REMAINING UNTIL THE FRONT PUSHES
THROUGH LATE TONIGHT AND MONDAY MORNING. WATCHING THE STRATUS
STRUGGLE TO DEVELOP IN UPSTREAM AREAS TODAY...AND WITH THE RAP
CONTINUOUSLY BACKING OFF ON THE TIMING OF BRINGING IT NORTH...JUST
DON/T HAVE THE CONFIDENCE THAT THE CLOUDS WILL GET INTO THE LOCAL
AREA TONIGHT AND THE FORECAST TAKES THAT INTO ACCOUNT. IF THE
STRATUS DOES MOVE IN...MAY HAVE TO TAKE A LOOK AT LOW TEMPERATURES
TONIGHT...ALTHOUGH THEY SHOULDN/T HAVE AN IMPACT ON HIGHS MONDAY AS
THEY WOULD BE PUSHED OUT OF THE AREA BEFORE PEAK HEATING.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SUN NOV 24 2013
A REINFORCING SHOT OF ARCTIC AIR WILL MOVE THROUGH THE DAKOTAS
INTO NEBRASKA MONDAY NIGHT AND TUESDAY. THIS WILL BRING A GLANCING
BLOW OF COLDER AIR...WHICH IS ACTUALLY NOT AS COLD AS THE PREVIOUS
ONE SATURDAY. WENT A FEW DEGREES ABOVE GUIDANCE LOWS MONDAY NIGHT
WITH MID/UPPER TEENS. WEAK COLD AIR ADVECTION TUESDAY WITH H85
TEMPS AS LOW AS -15C PER NAM MODEL. THIS LOOK TOO COLD AND FAVORED
THE GFS -11C. USING CONSALL INTO A BLEND HIGHS NEAR 25 AT ONL TO
36 AT IML. TEMPERATURES THEN WARMUP FOR WEDNESDAY. AS SURFACE HIGH
SLIDES EAST...A RETURN SOUTH TO SOUTHWEST FLOW DEVELOPS. WHILE
HIGHS TO BE LIMITED TO NEAR 30 AT BBW AND ONL...THE WESTERN TIER
OF COUNTIES TO WARM TO 40-43 DEGREES. DRY CONDITIONS TO ALSO PREVAIL.
FOR THANKSGIVING DAY THROUGH THE WEEKEND...DRY AND SEASONAL
TEMPERATURES ARE FORECAST. THE UPPER FLOW WILL REMAIN FAIRLY
ZONAL. THIS HIGHLIGHTED BY AN UPPER TROUGH DIGGING FROM BRITISH
COLUMBIA INTO THE NORTHERN PLAINS AND A CLOSED LOW REMAINING OFF
THE CALIF. COAST. ONLY A WEAK COLD FRONT INDICATED FRIDAY
NIGHT...WHICH SHOULD HAVE MINIMAL IMPACT TO HIGHS SATURDAY AND
SUNDAY. ONLY VERY MINOR CHANGES TO HIGHS THROUGH THIS WEEKEND WITH
MAINLY UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CST SUN NOV 24 2013
WINDS WILL BE BREEZY FROM THE SOUTH-SOUTHWEST THROUGH THE
AFTERNOON. WINDS WILL DIMINISH BY 00Z...THEN WILL SWITCH TO THE
NORTHWEST OVERNIGHT AS A WEAK FRONT MOVES ACROSS WESTERN
NEBRASKA. LOOK FOR THE WINDS TO INCREASE THEN BY LATE MONDAY
MORNING...WHERE GUSTS COULD REACH 20KTS INTO THE AFTERNOON. THERE
CONTINUES TO BE INDICATION OF STRATUS DEVELOPMENT INTO SOUTHWEST
NEBRASKA TONIGHT /PRIMARILY IMPACTING KLBF/ AS MODELS ARE SHOWING A
SHALLOW LAYER OF MOISTURE IN THE BOUNDARY LAYER MOVING INTO THE
AREA. THE MODELS HAVE BEEN HAVING SOME PROBLEMS HANDLING THIS LOW
LEVEL MOISTURE OVER THE LAST SEVERAL DAYS SO DON/T HAVE MUCH
CONFIDENCE IN THAT SOLUTION AND LEFT THE MVFR CEILINGS OUT OF THE
FORECAST FOR NOW. WILL KEEP A WATCH ON THIS THROUGH THE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...ROBERG
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1225 PM CST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SUN NOV 24 2013
1045 MB ARCTIC HIGH PRESSURE CENTERED NEAR KANSAS CITY WILL MOVE
RAPIDLY EAST THROUGH THE MIDSOUTH TODAY AND BE LOCATED OVER NORTH
CAROLINA BY MONDAY MORNING.
THE MODELS INSIST STRATUS WILL FORM IN THE RETURN FLOW SETTING
ACROSS SWRN NEB. AT 08Z THE NEAREST STRATUS WAS OVER NW TEX...ABOUT
500 MILES SOUTH OF THE FORECAST POSITION OF THE MODEL CONSENSUS. NO
STRATUS IS EXPECTED TO DEVELOP AT THIS TIME BUT MID LEVEL CLOUDS
ACROSS ERN COLO/WRN KS ARE EXPECTED TO LIFT NORTH PART WAY THROUGH
THE FCST AREA AND THEN GET SHUNTED EAST WITH THE APPROACH OF A NRN
STREAM SHORTWAVE THIS EVENING. TEMPERATURES ARE EXPECTED TO RISE
INTO THE 30S TO AROUND 40. WARMER GUIDANCE WAS USED FOR THE FORECAST
OWING TO THE CONTAMINATION IN THE SKY COVER SHOWN BY MOST MODELS.
FOR TONIGHT A COLD FRONT WILL BE MOVING SOUTH THROUGH THE NRN HIGH
PLAINS. A THERMAL RIDGE WILL BE RUNNING OUT AHEAD OF THE COLD FRONT
WHICH WILL LIKELY PRODUCE THE COOLEST LOWS IN THE SOUTH BEFORE THE
WIND SHIFT DEVELOPS LATE TONIGHT. THUS LOWS IN THE TEENS ARE
EXPECTED SOUTH WITH 20S NORTH.
SOUTH AND SOUTHWEST WINDS TODAY INCREASE TO 15 TO 25 MPH. LOW
PRESSURE CURRENTLY ACROSS GREAT SLAVE LAKE WILL DIVE SOUTHEAST
TOWARD LAKE SUPERIOR TODAY AND TONIGHT. THE 500M AGL WINDS IN THE
NAM AND RAP MODELS INCREASE TO NEAR 30 MPH AT THE SFC EAST OF
HIGHWAY 183. THIS WOULD SUPPORT GUSTS TO 35 MPH BUT LIMITED VERTICAL
MIXING IN COOL RETURN FLOW SHOULD LIMIT SUSTAINED WIND SPEEDS TO 25
MPH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM CST SUN NOV 24 2013
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL MIGRATE FROM
ARIZONA TO WEST TEXAS BY MONDAY. MEANWHILE ANOTHER POTENT
SHORTWAVE TROUGH WILL DIVE SOUTHEAST THROUGH CENTRAL
CANADA...REACHING THE GREAT LAKES BY TUESDAY EVENING. THE
SOUTHERN PLAINS LOW AND GREAT LAKES TROUGH WILL EVENTUALLY
PHASE TO OUR EAST...AND BRING HEAVY PRECIPITATION ALONG THE EAST
COAST WEDNESDAY AND WEDNESDAY NIGHT. AS MENTIONED...THE MAJORITY
OF THE WEATHER WITH THESE SYSTEMS REMAINS TO OUR EAST...BUT A COLD
FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY. THIS WILL BRING
ANOTHER REINFORCING SHOT OF ARCTIC AIR TO THE REGION. THE BRUNT OF
THE ARCTIC AIR WILL BE FELT ACROSS THE MISSOURI RIVER
VALLEY...WHERE HIGHS IN THE 20S ARE EXPECTED. FARTHER WEST ACROSS
THE HIGH PLAINS OF WESTERN NEBRASKA AND EASTERN COLORADO...THE
COLD FRONT WILL HAVE LITTLE IMPACT...WITH A PACIFIC AIRMASS AND
HIGHS IN THE 40S REMAINING IN PLACE.
BY MID TO LATE WEEK...UPPER LEVEL RIDGING WILL BUILD EAST ACROSS
THE CENTRAL CONUS. WARMER PACIFIC AIR WILL ALSO SPREAD EAST...WITH
HIGHS IN THE UPPER 30S TO MID 40S REGION WIDE. LITTLE
PRECIPITATION IS EXPECTED...AS ATMOSPHERIC MOISTURE REMAINS
LIMITED THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CST SUN NOV 24 2013
WINDS WILL BE BREEZY FROM THE SOUTH-SOUTHWEST THROUGH THE
AFTERNOON. WINDS WILL DIMINISH BY 00Z...THEN WILL SWITCH TO THE
NORTHWEST OVERNIGHT AS A WEAK FRONT MOVES ACROSS WESTERN
NEBRASKA. LOOK FOR THE WINDS TO INCREASE THEN BY LATE MONDAY
MORNING...WHERE GUSTS COULD REACH 20KTS INTO THE AFTERNOON. THERE
CONTINUES TO BE INDICATION OF STRATUS DEVELOPMENT INTO SOUTHWEST
NEBRASKA TONIGHT /PRIMARILY IMPACTING KLBF/ AS MODELS ARE SHOWING A
SHALLOW LAYER OF MOISTURE IN THE BOUNDARY LAYER MOVING INTO THE
AREA. THE MODELS HAVE BEEN HAVING SOME PROBLEMS HANDLING THIS LOW
LEVEL MOISTURE OVER THE LAST SEVERAL DAYS SO DON/T HAVE MUCH
CONFIDENCE IN THAT SOLUTION AND LEFT THE MVFR CEILINGS OUT OF THE
FORECAST FOR NOW. WILL KEEP A WATCH ON THIS THROUGH THE AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
524 AM CST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SUN NOV 24 2013
1045 MB ARCTIC HIGH PRESSURE CENTERED NEAR KANSAS CITY WILL MOVE
RAPIDLY EAST THROUGH THE MIDSOUTH TODAY AND BE LOCATED OVER NORTH
CAROLINA BY MONDAY MORNING.
THE MODELS INSIST STRATUS WILL FORM IN THE RETURN FLOW SETTING
ACROSS SWRN NEB. AT 08Z THE NEAREST STRATUS WAS OVER NW TEX...ABOUT
500 MILES SOUTH OF THE FORECAST POSITION OF THE MODEL CONSENSUS. NO
STRATUS IS EXPECTED TO DEVELOP AT THIS TIME BUT MID LEVEL CLOUDS
ACROSS ERN COLO/WRN KS ARE EXPECTED TO LIFT NORTH PART WAY THROUGH
THE FCST AREA AND THEN GET SHUNTED EAST WITH THE APPROACH OF A NRN
STREAM SHORTWAVE THIS EVENING. TEMPERATURES ARE EXPECTED TO RISE
INTO THE 30S TO AROUND 40. WARMER GUIDANCE WAS USED FOR THE FORECAST
OWING TO THE CONTAMINATION IN THE SKY COVER SHOWN BY MOST MODELS.
FOR TONIGHT A COLD FRONT WILL BE MOVING SOUTH THROUGH THE NRN HIGH
PLAINS. A THERMAL RIDGE WILL BE RUNNING OUT AHEAD OF THE COLD FRONT
WHICH WILL LIKELY PRODUCE THE COOLEST LOWS IN THE SOUTH BEFORE THE
WIND SHIFT DEVELOPS LATE TONIGHT. THUS LOWS IN THE TEENS ARE
EXPECTED SOUTH WITH 20S NORTH.
SOUTH AND SOUTHWEST WINDS TODAY INCREASE TO 15 TO 25 MPH. LOW
PRESSURE CURRENTLY ACROSS GREAT SLAVE LAKE WILL DIVE SOUTHEAST
TOWARD LAKE SUPERIOR TODAY AND TONIGHT. THE 500M AGL WINDS IN THE
NAM AND RAP MODELS INCREASE TO NEAR 30 MPH AT THE SFC EAST OF
HIGHWAY 183. THIS WOULD SUPPORT GUSTS TO 35 MPH BUT LIMITED VERTICAL
MIXING IN COOL RETURN FLOW SHOULD LIMIT SUSTAINED WIND SPEEDS TO 25
MPH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM CST SUN NOV 24 2013
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL MIGRATE FROM
ARIZONA TO WEST TEXAS BY MONDAY. MEANWHILE ANOTHER POTENT
SHORTWAVE TROUGH WILL DIVE SOUTHEAST THROUGH CENTRAL
CANADA...REACHING THE GREAT LAKES BY TUESDAY EVENING. THE
SOUTHERN PLAINS LOW AND GREAT LAKES TROUGH WILL EVENTUALLY
PHASE TO OUR EAST...AND BRING HEAVY PRECIPITATION ALONG THE EAST
COAST WEDNESDAY AND WEDNESDAY NIGHT. AS MENTIONED...THE MAJORITY
OF THE WEATHER WITH THESE SYSTEMS REMAINS TO OUR EAST...BUT A COLD
FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY. THIS WILL BRING
ANOTHER REINFORCING SHOT OF ARCTIC AIR TO THE REGION. THE BRUNT OF
THE ARCTIC AIR WILL BE FELT ACROSS THE MISSOURI RIVER
VALLEY...WHERE HIGHS IN THE 20S ARE EXPECTED. FARTHER WEST ACROSS
THE HIGH PLAINS OF WESTERN NEBRASKA AND EASTERN COLORADO...THE
COLD FRONT WILL HAVE LITTLE IMPACT...WITH A PACIFIC AIRMASS AND
HIGHS IN THE 40S REMAINING IN PLACE.
BY MID TO LATE WEEK...UPPER LEVEL RIDGING WILL BUILD EAST ACROSS
THE CENTRAL CONUS. WARMER PACIFIC AIR WILL ALSO SPREAD EAST...WITH
HIGHS IN THE UPPER 30S TO MID 40S REGION WIDE. LITTLE
PRECIPITATION IS EXPECTED...AS ATMOSPHERIC MOISTURE REMAINS
LIMITED THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 523 AM CST SUN NOV 24 2013
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT. MIDLEVEL CLOUD SHIELD
ACROSS NERN COLO/SWRN NEB/NWRN KS WILL MOVE NORTH TO NEAR KTIF AND
THEN GET SHUNTED EAST AS AN UPPER LEVEL DISTURBANCE...CURRENTLY
NEAR GREAT SLAVE LAKE...DROPS SOUTH INTO SRN CANADA. A COLD FRONT
WILL MOVE THROUGH THE FCST AREA TONIGHT PRODUCING A WIND SHIFT
WITH NW WINDS DEVELOPING.
NOTE THE MODELS DEVELOP LOW CLOUDS/MVFR CIGS THIS MORNING ACROSS
SRN NEB AND EXPAND THESE CLOUDS NORTH TONIGHT BUT THIS FCST HAS
NOT VERIFIED SINCE 00Z LAST NIGHT SO WE ARE SETTING THAT FCST
ASIDE AND WAITING ON SFC OBS TO SHOW THIS DEVELOPMENT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
343 AM CST SUN NOV 24 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 323 AM CST SUN NOV 24 2013
1045 MB ARCTIC HIGH PRESSURE CENTERED NEAR KANSAS CITY WILL MOVE
RAPIDLY EAST THROUGH THE MIDSOUTH TODAY AND BE LOCATED OVER NORTH
CAROLINA BY MONDAY MORNING.
THE MODELS INSIST STRATUS WILL FORM IN THE RETURN FLOW SETTING
ACROSS SWRN NEB. AT 08Z THE NEAREST STRATUS WAS OVER NW TEX...ABOUT
500 MILES SOUTH OF THE FORECAST POSITION OF THE MODEL CONSENSUS. NO
STRATUS IS EXPECTED TO DEVELOP AT THIS TIME BUT MID LEVEL CLOUDS
ACROSS ERN COLO/WRN KS ARE EXPECTED TO LIFT NORTH PART WAY THROUGH
THE FCST AREA AND THEN GET SHUNTED EAST WITH THE APPROACH OF A NRN
STREAM SHORTWAVE THIS EVENING. TEMPERATURES ARE EXPECTED TO RISE
INTO THE 30S TO AROUND 40. WARMER GUIDANCE WAS USED FOR THE FORECAST
OWING TO THE CONTAMINATION IN THE SKY COVER SHOWN BY MOST MODELS.
FOR TONIGHT A COLD FRONT WILL BE MOVING SOUTH THROUGH THE NRN HIGH
PLAINS. A THERMAL RIDGE WILL BE RUNNING OUT AHEAD OF THE COLD FRONT
WHICH WILL LIKELY PRODUCE THE COOLEST LOWS IN THE SOUTH BEFORE THE
WIND SHIFT DEVELOPS LATE TONIGHT. THUS LOWS IN THE TEENS ARE
EXPECTED SOUTH WITH 20S NORTH.
SOUTH AND SOUTHWEST WINDS TODAY INCREASE TO 15 TO 25 MPH. LOW
PRESSURE CURRENTLY ACROSS GREAT SLAVE LAKE WILL DIVE SOUTHEAST
TOWARD LAKE SUPERIOR TODAY AND TONIGHT. THE 500M AGL WINDS IN THE
NAM AND RAP MODELS INCREASE TO NEAR 30 MPH AT THE SFC EAST OF
HIGHWAY 183. THIS WOULD SUPPORT GUSTS TO 35 MPH BUT LIMITED VERTICAL
MIXING IN COOL RETURN FLOW SHOULD LIMIT SUSTAINED WIND SPEEDS TO 25
MPH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 323 AM CST SUN NOV 24 2013
A SLOW MOVING UPPER LEVEL LOW PRESSURE SYSTEM WILL MIGRATE FROM
ARIZONA TO WEST TEXAS BY MONDAY. MEANWHILE ANOTHER POTENT
SHORTWAVE TROUGH WILL DIVE SOUTHEAST THROUGH CENTRAL
CANADA...REACHING THE GREAT LAKES BY TUESDAY EVENING. THE
SOUTHERN PLAINS LOW AND GREAT LAKES TROUGH WILL EVENTUALLY
PHASE TO OUR EAST...AND BRING HEAVY PRECIPITATION ALONG THE EAST
COAST WEDNESDAY AND WEDNESDAY NIGHT. AS MENTIONED...THE MAJORITY
OF THE WEATHER WITH THESE SYSTEMS REMAINS TO OUR EAST...BUT A COLD
FRONT WILL DROP SOUTH THROUGH THE AREA TUESDAY. THIS WILL BRING
ANOTHER REINFORCING SHOT OF ARCTIC AIR TO THE REGION. THE BRUNT OF
THE ARCTIC AIR WILL BE FELT ACROSS THE MISSOURI RIVER
VALLEY...WHERE HIGHS IN THE 20S ARE EXPECTED. FARTHER WEST ACROSS
THE HIGH PLAINS OF WESTERN NEBRASKA AND EASTERN COLORADO...THE
COLD FRONT WILL HAVE LITTLE IMPACT...WITH A PACIFIC AIRMASS AND
HIGHS IN THE 40S REMAINING IN PLACE.
BY MID TO LATE WEEK...UPPER LEVEL RIDGING WILL BUILD EAST ACROSS
THE CENTRAL CONUS. WARMER PACIFIC AIR WILL ALSO SPREAD EAST...WITH
HIGHS IN THE UPPER 30S TO MID 40S REGION WIDE. LITTLE
PRECIPITATION IS EXPECTED...AS ATMOSPHERIC MOISTURE REMAINS
LIMITED THROUGH THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1147 PM CST SAT NOV 23 2013
UPPER LEVEL LOW PRESSURE WILL TRACK ACROSS THE SOUTHERN ROCKIES
INTO THE SOUTHERN PLAINS OVER THE NEXT 24 HOURS. THIS FEATURE WILL
SPREAD ABUNDANT HIGH CLOUDS INTO SOUTHERN NEBRASKA
TONIGHT...FOLLOWED BY SOME LOW LEVEL CLOUDINESS ON SUNDAY. AT THIS
TIME...LOW LEVEL CLOUDINESS WITH CIGS BETWEEN 3000 AND 5000 FT AGL
WILL BE POSSIBLE AT THE KLBF TERMINAL SUNDAY MORNING THROUGH
SUNDAY EVENING. AT THE KVTN TERMINAL...SKIES WILL BE CLEAR TONIGHT
WITH SOME SCATTERED TO BROKEN HIGH CLOUDS AON 25000 FT AGL
POSSIBLE AFTER 16Z SUNDAY. WINDS WILL BE FROM THE SOUTH AT 5 TO 10
KTS TONIGHT...INCREASING TO 15 TO 25 KTS SUNDAY...DIMINISHING BACK
TO AROUND 10 KTS SUNDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1105 AM PST SUN NOV 24 2013
.SYNOPSIS...A SLOW MOVING LOW PRESSURE WILL FINALLY PULL AWAY FROM
THE AREA TODAY RESULTING IN DRIER CONDITIONS. FURTHER WARMING IS
EXPECTED ACROSS THE AREA MONDAY THROUGH WEDNESDAY. ANOTHER AREA OF
LOW PRESSURE DROPPING SOUTH NEAR THE CALIFORNIA COAST MAY BRING A
FEW SHOWERS MAINLY TO WESTERN PORTIONS OF THE AREA FOR THANKSGIVING
DAY AND FRIDAY.
&&
.UPDATE...UPPER LOW EXITING THE REGION TODAY WITH A FEW SHOWERS
STILL POSSIBLE IN MOHAVE COUNTY AND FAR EASTERN LINCOLN COUNTY.
CLOUDS HAD CLEARED OUT A BIT MORE THAN PREVIOUSLY FORECAST AND THE
SKY COVER GRID WAS ADJUSTED TO REDUCE SKY COVER OVER A GOOD PORTION
OF THE FORECAST AREA. NO OTHER UPDATES NEEDED.
&&
.AVIATION...FOR MCCARRAN...SOME DRYING OF THE LOWER LEVELS OF THE
ATMOSPHERE IS TAKING PLACE...AND THE LOWEST CLOUD BASES HAVE
SCATTERED OUT LEAVING CIGS GENERALLY AROUND 10K FEET. CLEARING
BEGINS TONIGHT WITH MAINLY CLEAR SKIES EXPECTED MONDAY. WINDS WILL
FAVOR MORE TYPICAL DIURNAL TRENDS THROUGH TONIGHT AT SPEEDS MAINLY
LESS THAN 6 KTS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS SHOULD BE CONFINED TO EASTERN MOHAVE COUNTY
THROUGH AROUND 21Z. CIGS BTWN 5K-8K FEET IN THIS AREA OTHERWISE
SCT-BKN AROUND 10K FEET. WINDS OVERALL SHOULD FAVOR TYPICAL DIURNAL
TRENDS AT 10 KTS OR LESS. MAINLY CLEAR CONDITIONS MONDAY EXPECT FOR
PATCHY FG/BR POSSIBLE EARLY IN THE MORNING.
&&
.PREV DISCUSSION...
254 AM PST SUN NOV 24 2013
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
WELL AFTER 3 DAYS OF CLOUDS AND RAIN WE ARE FINALLY IN FOR A CHANGE
TODAY IN VEGAS WITH THE POTENTIAL OF SEEING SOME SUNSHINE AS A SLOW
MOVING UPPER LEVEL LOW FINALLY HEADS OUT OF THE AREA. THE LATEST
WATER VAPOR IMAGERY SHOWS THE CENTER OF THE LOW NEAR PARKER, ARIZONA
AS OF EARLY THIS MORNING WITH MOISTURE STILL WRAPPING AROUND THE
BACK SIDE OF THE LOW. THE MAIN ISSUE FOR TODAY, ESPECIALLY FOR THIS
MORNING, WILL BE HOW QUICKLY WE ARE ABLE TO DRY THINGS OUT ACROSS
THE AREA WHICH WILL DETERMINE WHEN SHOWERS COME TO AN END AND HOW
QUICKLY ANY LOW AND MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED.
THE LATEST RADAR IMAGES FROM KESX SHOW MAINLY LIGHT RETURNS ACROSS
THE EASTERN PORTIONS OF THE AREA AND IT IS LIKELY THE RADAR IS
OVERSHOOTING SOME OF THE PRECIPITATION. BASED ON THE HRRR AND THE
00Z REGIONAL WRF, THE BEST POTENTIAL FOR ANY SHOWERS THIS MORNING
WILL BE ACROSS NORTHERN AND CENTRAL MOHAVE COUNTY, LINCOLN COUNTY
AND THE MOUNTAINS OF CLARK COUNTY AND I HAVE KEPT IN 20-30 POPS WITH
SOME NEAR 40 POP VALUES (IN THE HIGHEST TERRAIN) OVER THESE AREAS.
AS THE LOW LEVELS START TO DRY OUT, WE SHOULD SEE THE LOWER AND
MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED IN COVERAGE BY EARLY
THIS AFTERNOON ESPECIALLY FROM LINCOLN AND CLARK COUNTIES ON EAST.
THERE COULD BE A LITTLE FOG AROUND, MAINLY ALONG THE INTERFACES OF
THE HIGHER TERRAIN WHERE THEY HIT THE CLOUD BASES. OUTSIDE OF THE
COLORADO CITY AREA WHERE FOG WAS REPORTED EARLIER THIS MORNING, NO
OTHER FOG WILL BE PLACED IN THE GRIDS AS THE COVERAGE LOOKS TOO
SMALL. WITH THE COLD POOL DEPARTING THE AREA ASSOCIATED WITH THE
LOW, A LOT OF WARMING ALOFT WILL TAKE PLACE TODAY. THIS COMBINED
WITH SOME SUN WILL MAKE FOR A BIG BOOST IN TEMPS, HOWEVER, HIGHS
SHOULD STILL BE ABOUT 10 DEGREES BELOW NORMAL ACROSS THE AREA AND I
DID CHOP A FEW DEGREES OFF THE PREVIOUS FORECAST BASED ON THE LATEST
GUIDANCE.
FOR TONIGHT, SOME LOW AND MID-LEVEL CLOUDS MAY LINGER EARLY ON,
OTHERWISE EXPECT A CLEAR SKY. TEMPS SHOULD BE A LITTLE COLDER WITH
LESS CLOUD COVER. ONE CONCERN WILL BE IN THE WESTERN PORTIONS OF THE
MOJAVE DESERT, MAINLY ACROSS NW SAN BERNARDINO COUNTY AND FAR SW
INYO COUNTY, WHERE PATCHY FOG MAY BE POSSIBLE. STATISTICAL GUIDANCE
SHOWS NEARLY SATURATED OR SATURATED SFC CONDITIONS TONIGHT
(ESPECIALLY THE COLDER MET GUIDANCE) AND BUFKIT SOUNDINGS FROM THE
NAM SHOW THE VERY LOW-LEVELS MOISTENING AROUND OR JUST AFTER
SUNRISE. I WILL GO AHEAD AND ADD PATCHY FOG IN HERE GIVEN THE WET
GROUND FROM THE RECENT RAINS, LIGHT WINDS AND CLEAR SKY EXPECTED
INITIALLY TONIGHT, HOWEVER CONFIDENCE IS NOT THE BEST WITH THIS.
RIDGING ALOFT IS FORECAST TO SLIDE EAST ACROSS THE AREA FROM MONDAY
INTO TUESDAY. THIS WILL RESULT IN FURTHER WARMING WITH HIGHS ABOUT
4-6 DEGREES BELOW NORMAL. AS THE RIDGE AXIS SLIDES EAST ON TUESDAY
AND A TROUGH OFFSHORE STARTS TO APPROACH HIGH LEVEL MOISTURE SHOULD
START TO SPILL IN FROM THE WEST AND COULD BRING A DECENT AMOUNT OF
CIRRUS TO THE AREA FOR TUESDAY NIGHT.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...THE PACIFIC SYSTEM THAT IS
FORECAST TO APPROACH THE WEST COAST BY LATE WEDNESDAY DOES NOT
APPEAR TO HAVE THE MAKINGS OF A SIGNIFICANT STORM FOR OUR FORECAST
AREA. THE LATEST MEDIUM RANGE MODELS ARE NOW IN BETTER AGREEMENT
WITH THE TRACK OF THE SYSTEM....BRINGING THE CENTER OF THE CLOSED
LOW ALONG THE CENTRAL CALIFORNIA COAST THANKSGIVING DAY THEN
INDICATING IT WILL TRANSFORM INTO A WEAKER AND ELONGATED POSITIVE
TILT TROUGH AS IT SAGS OFF THE SOUTHERN CALIFORNIA COAST FRIDAY AND
CONTINUES WORKING TOWARD NORTHERN BAJA SATURDAY. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE SOUTHERN SIERRA AND THE INYO COUNTY
MOUNTAINS THANKSGIVING DAY INTO THURSDAY NIGHT AS A SHORTWAVE EJECTS
OUT OF THE COASTAL LOW ACROSS SOUTHEAST CALIFORNIA AND SOUTHERN
NEVADA. SNOW WILL BE LIKELY IN THE HIGH SIERRA WITH LESSER CHANCES
FOR LIGHT SNOW SHOWERS ACROSS THE REST OF THE INYO COUNTY MOUNTAINS
AND THE MOUNTAINS OF SOUTHERN NEVADA. PRECIPITATION CHANCES THEN
DIMINISH CONSIDERABLY FRIDAY INTO SATURDAY. CONSIDERING THE SEED FOR
THIS SYSTEM IS CURRENTLY A BARELY NOTICEABLE PACIFIC SHORTWAVE NEAR
40N AND THE DATELINE...THERE ARE SURE TO BE SOME CHANGES DURING ITS
EVOLUTION. IT BEARS WATCHING BUT DOES NOT LOOK THAT IMPRESSIVE FOR
NOW.
&&
.CLIMATE...WE HAVE HAD OUR FILL OF CLOUDS IN THE SKY HERE IN VEGAS
THE LAST FEW DAYS BUT WHEN IS THE LAST TIME WE HAD 3 DAYS WITH THIS
MUCH CLOUD COVER AROUND? BASED ON SUNRISE TO SUNSET CLOUD COVER, THE
LAST TIME WE HAD BACK-TO-BACK DAYS WITH A 10 (WHICH MEANS AS CLOUDY
AS IT GETS) WAS ON DECEMBER 20TH AND 21ST OF 2010. THOSE AROUND THEN
HERE WILL REMEMBER THAT AS A PERIOD WHEN A BARRAGE OF STORMS CAME IN
FROM THE PACIFIC. THIS WAS ALSO THE ONLY SUCH PERIOD LOOKING BACK
THROUGH SKY COVER RECORDS FOR THE LAST 5 YEARS TO NOVEMBER 2008.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
UPDATE...HARRISON
AVIATION...SALMEN
PREV DISCUSSION...STACHELSKI/ADAIR
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
254 AM PST SUN NOV 24 2013
.SYNOPSIS...A SLOW MOVING LOW PRESSURE WILL FINALLY PULL AWAY FROM
THE AREA TODAY RESULTING IN DRIER CONDITIONS. FURTHER WARMING IS
EXPECTED ACROSS THE AREA MONDAY THROUGH WEDNESDAY. ANOTHER AREA OF
LOW PRESSURE DROPPING SOUTH NEAR THE CALIFORNIA COAST MAY BRING A
FEW SHOWERS MAINLY TO WESTERN PORTIONS OF THE AREA FOR THANKSGIVING
DAY AND FRIDAY.
&&
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
WELL AFTER 3 DAYS OF CLOUDS AND RAIN WE ARE FINALLY IN FOR A CHANGE
TODAY IN VEGAS WITH THE POTENTIAL OF SEEING SOME SUNSHINE AS A SLOW
MOVING UPPER LEVEL LOW FINALLY HEADS OUT OF THE AREA. THE LATEST
WATER VAPOR IMAGERY SHOWS THE CENTER OF THE LOW NEAR PARKER, ARIZONA
AS OF EARLY THIS MORNING WITH MOISTURE STILL WRAPPING AROUND THE
BACK SIDE OF THE LOW. THE MAIN ISSUE FOR TODAY, ESPECIALLY FOR THIS
MORNING, WILL BE HOW QUICKLY WE ARE ABLE TO DRY THINGS OUT ACROSS
THE AREA WHICH WILL DETERMINE WHEN SHOWERS COME TO AN END AND HOW
QUICKLY ANY LOW AND MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED.
THE LATEST RADAR IMAGES FROM KESX SHOW MAINLY LIGHT RETURNS ACROSS
THE EASTERN PORTIONS OF THE AREA AND IT IS LIKELY THE RADAR IS
OVERSHOOTING SOME OF THE PRECIPITATION. BASED ON THE HRRR AND THE
00Z REGIONAL WRF, THE BEST POTENTIAL FOR ANY SHOWERS THIS MORNING
WILL BE ACROSS NORTHERN AND CENTRAL MOHAVE COUNTY, LINCOLN COUNTY
AND THE MOUNTAINS OF CLARK COUNTY AND I HAVE KEPT IN 20-30 POPS WITH
SOME NEAR 40 POP VALUES (IN THE HIGHEST TERRAIN) OVER THESE AREAS.
AS THE LOW LEVELS START TO DRY OUT, WE SHOULD SEE THE LOWER AND
MID-LEVEL CLOUDS START TO BECOME MORE SCATTERED IN COVERAGE BY EARLY
THIS AFTERNOON ESPECIALLY FROM LINCOLN AND CLARK COUNTIES ON EAST.
THERE COULD BE A LITTLE FOG AROUND, MAINLY ALONG THE INTERFACES OF
THE HIGHER TERRAIN WHERE THEY HIT THE CLOUD BASES. OUTSIDE OF THE
COLORADO CITY AREA WHERE FOG WAS REPORTED EARLIER THIS MORNING, NO
OTHER FOG WILL BE PLACED IN THE GRIDS AS THE COVERAGE LOOKS TOO
SMALL. WITH THE COLD POOL DEPARTING THE AREA ASSOCIATED WITH THE
LOW, A LOT OF WARMING ALOFT WILL TAKE PLACE TODAY. THIS COMBINED
WITH SOME SUN WILL MAKE FOR A BIG BOOST IN TEMPS, HOWEVER, HIGHS
SHOULD STILL BE ABOUT 10 DEGREES BELOW NORMAL ACROSS THE AREA AND I
DID CHOP A FEW DEGREES OFF THE PREVIOUS FORECAST BASED ON THE LATEST
GUIDANCE.
FOR TONIGHT, SOME LOW AND MID-LEVEL CLOUDS MAY LINGER EARLY ON,
OTHERWISE EXPECT A CLEAR SKY. TEMPS SHOULD BE A LITTLE COLDER WITH
LESS CLOUD COVER. ONE CONCERN WILL BE IN THE WESTERN PORTIONS OF THE
MOJAVE DESERT, MAINLY ACROSS NW SAN BERNARDINO COUNTY AND FAR SW
INYO COUNTY, WHERE PATCHY FOG MAY BE POSSIBLE. STATISTICAL GUIDANCE
SHOWS NEARLY SATURATED OR SATURATED SFC CONDITIONS TONIGHT
(ESPECIALLY THE COLDER MET GUIDANCE) AND BUFKIT SOUNDINGS FROM THE
NAM SHOW THE VERY LOW-LEVELS MOISTENING AROUND OR JUST AFTER
SUNRISE. I WILL GO AHEAD AND ADD PATCHY FOG IN HERE GIVEN THE WET
GROUND FROM THE RECENT RAINS, LIGHT WINDS AND CLEAR SKY EXPECTED
INITIALLY TONIGHT, HOWEVER CONFIDENCE IS NOT THE BEST WITH THIS.
RIDGING ALOFT IS FORECAST TO SLIDE EAST ACROSS THE AREA FROM MONDAY
INTO TUESDAY. THIS WILL RESULT IN FURTHER WARMING WITH HIGHS ABOUT
4-6 DEGREES BELOW NORMAL. AS THE RIDGE AXIS SLIDES EAST ON TUESDAY
AND A TROUGH OFFSHORE STARTS TO APPROACH HIGH LEVEL MOISTURE SHOULD
START TO SPILL IN FROM THE WEST AND COULD BRING A DECENT AMOUNT OF
CIRRUS TO THE AREA FOR TUESDAY NIGHT.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...THE PACIFIC SYSTEM THAT IS
FORECAST TO APPROACH THE WEST COAST BY LATE WEDNESDAY DOES NOT
APPEAR TO HAVE THE MAKINGS OF A SIGNIFICANT STORM FOR OUR FORECAST
AREA. THE LATEST MEDIUM RANGE MODELS ARE NOW IN BETTER AGREEMENT
WITH THE TRACK OF THE SYSTEM....BRINGING THE CENTER OF THE CLOSED
LOW ALONG THE CENTRAL CALIFORNIA COAST THANKSGIVING DAY THEN
INDICATING IT WILL TRANSFORM INTO A WEAKER AND ELONGATED POSITIVE
TILT TROUGH AS IT SAGS OFF THE SOUTHERN CALIFORNIA COAST FRIDAY AND
CONTINUES WORKING TOWARD NORTHERN BAJA SATURDAY. THE BEST CHANCE FOR
PRECIPITATION WILL BE ACROSS THE SOUTHERN SIERRA AND THE INYO COUNTY
MOUNTAINS THANKSGIVING DAY INTO THURSDAY NIGHT AS A SHORTWAVE EJECTS
OUT OF THE COASTAL LOW ACROSS SOUTHEAST CALIFORNIA AND SOUTHERN
NEVADA. SNOW WILL BE LIKELY IN THE HIGH SIERRA WITH LESSER CHANCES
FOR LIGHT SNOW SHOWERS ACROSS THE REST OF THE INYO COUNTY MOUNTAINS
AND THE MOUNTAINS OF SOUTHERN NEVADA. PRECIPITATION CHANCES THEN
DIMINISH CONSIDERABLY FRIDAY INTO SATURDAY. CONSIDERING THE SEED FOR
THIS SYSTEM IS CURRENTLY A BARELY NOTICEABLE PACIFIC SHORTWAVE NEAR
40N AND THE DATELINE...THERE ARE SURE TO BE SOME CHANGES DURING ITS
EVOLUTION. IT BEARS WATCHING BUT DOES NOT LOOK THAT IMPRESSIVE FOR
NOW.
&&
.AVIATION...FOR MCCARRAN...THE MAIN ISSUE THIS MORNING WILL BE WITH
CIGS. CIGS INITIALLY SHOULD BE AROUND 4K FEET OR SO...BUT SOME
DRYING OF THE LOWER LEVELS OF THE ATMOSPHERE TAKES PLACE...LOWER
CLOUD BASES SHOULD BECOME MORE IN THE SCT-BKN RANGE WITH CLOUDS
BASES MAINLY AOA 5-8K FEET. CLOUDS SHOULD BE EXTENSIVE ALONG THE
EDGES OF THE VALLEY WITH MOUNTAIN OBSCURATIONS LIKELY THROUGH 18Z OR
SO TODAY. BY 00Z CLOUDS SHOULD BECOME MORE FEW-SCT AOA 5-8K FEET
WITH A CLEAR SKY EXPECTED TONIGHT. WINDS SHOULD FAVOR TYPICAL
DIURNAL TRENDS THROUGH TONIGHT AT SPEEDS OF 5 KTS OR LESS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS SHOULD DECREASE IN COVERAGE THIS MORNING AND BE
DONE ACROSS ALL AREAS EXCEPT EASTERN MOHAVE COUNTY BY 18Z TODAY AND
ANY LINGERING SHOWERS THERE SHOULD END BY 21Z TODAY OR SO. SCT-BKN
CLOUDS AOA 5K-8K FEET OTHERWISE TODAY WITH VFR VSBY EXCEPT NEAR ANY
FOG THIS MORNING. WINDS OVERALL SHOULD BE 10 KTS OR LESS WITH SPEEDS
TRENDING TOWARDS TYPICAL DIURNAL COMPONENTS OR A NORTHERLY
DIRECTION. FOR TONIGHT A CLEAR SKY IS EXPECTED WITH WINDS FAVORING
DIURNAL TRENDS. PATCHY FG/BR POSSIBLE IN AND AROUND KDAG AND
ELSEWHERE IN NW SAN BERNARDINO COUNTY WITH VSBY POTENTIALLY DROPPING
TO AT LEAST MVFR.
&&
.CLIMATE...WE HAVE HAD OUR FILL OF CLOUDS IN THE SKY HERE IN VEGAS
THE LAST FEW DAYS BUT WHEN IS THE LAST TIME WE HAD 3 DAYS WITH THIS
MUCH CLOUD COVER AROUND? BASED ON SUNRISE TO SUNSET CLOUD COVER, THE
LAST TIME WE HAD BACK-TO-BACK DAYS WITH A 10 (WHICH MEANS AS CLOUDY
AS IT GETS) WAS ON DECEMBER 20TH AND 21ST OF 2010. THOSE AROUND THEN
HERE WILL REMEMBER THAT AS A PERIOD WHEN A BARRAGE OF STORMS CAME IN
FROM THE PACIFIC. THIS WAS ALSO THE ONLY SUCH PERIOD LOOKING BACK
THROUGH SKY COVER RECORDS FOR THE LAST 5 YEARS TO NOVEMBER 2008.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
SHORT TERM/AVIATION/CLIMATE...STACHELSKI
LONG TERM...ADAIR
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
910 PM PST SAT NOV 23 2013
.SYNOPSIS...RAIN AND SNOW SHOWERS WILL CONTINUE TONIGHT AS A LOW
PRESSURE SYSTEM MOVES EAST ACROSS FAR SOUTHERN CALIFORNIA. GRADUAL
CLEARING IS EXPECTED FROM WEST TO EAST SUNDAY AS THE STORM SYSTEM
TRACKS INTO WESTERN NEW MEXICO. DRY AND WARMER CONDITIONS CAN BE
EXPECTED MONDAY THROUGH WEDNESDAY AS HIGH PRESSURE TRAVERSES THE
REGION. THE NEXT STORM SYSTEM MAY BRING A CHANCE OF SHOWERS TO
PORTIONS OF THE AREA FROM LATE THANKSGIVING DAY INTO FRIDAY.
&&
.UPDATE...OVERALL RADAR RETURNS ARE ON A DOWNWARD TREND THIS EVENING
ALTHOUGH SOME ACTIVITY IS PROBABLY BEING OVERSHOT BY THE RADAR.
BASED ON THE LATEST RADAR AS WELL AS THE LATEST HRRR MODEL AND 00Z
REGIONAL WRF, I HAVE GONE AHEAD AND MADE SOME MINOR ADJUSTMENTS TO
POPS TO FIT THE LATEST TRENDS SUGGESTED BY THESE TOOLS. THE MAIN
ISSUE FOR LAS VEGAS FOR THE REST OF TONIGHT WILL BE HOW MUCH
MOISTURE WRAPPING AROUND THE BACK SIDE OF THE UPPER LOW IS ABLE TO
SQUEEZE OUT ANY ADDITIONAL SHOWER ACTIVITY. IT APPEARS BY MIDNIGHT
WE SHOULD BE DONE WITH ANY SHOWERS FOR THE MOST PART AS FORECAST
SOUNDINGS FROM THE RAP AND WRF ALL SHOW THE LOWER-LEVELS STARTING TO
DRY OUT. I WILL LEAVE ANY WINTER WEATHER PRODUCTS OUT AS THESE AREAS
MAY SEE ANOTHER INCH OR TWO OF SNOW AND DEAL WITH THEM WITH THE
MORNING PACKAGE BASED ON HOW THINGS TREND.
AS FOR FOG TONIGHT, THERE MAY BE SOME IN THE HIGHER ELEVATIONS ALONG
THE SLOPES WHERE THE CLOUD BASES ARE AT GROUND LEVEL, BUT IT LOOKS
UNLIKELY IN THE LOWER ELEVATIONS AS THE LOW LEVELS HAVE EITHER
REALLY DRIED OUT (AS IN BISHOP WHERE DEWPOINTS HAVE DROPPED TO 11F)
OR ENOUGH STRATUS REMAINS RIGHT NOW THAT THINGS DO NOT APPEAR THEY
WILL CLEAR OUT TO ALLOW ANY FOG TO DEVELOP. FORECAST SOUNDINGS FOR
BISHOP AND DAGGETT FROM THE RAP AND WRF BOTH CONFIRM THIS AND ANY
FOG WAS YANKED FROM THE GRIDS WITH THIS UPDATE. OTHERWISE THE
FORECAST LOOKS IN GOOD SHAPE AS WE LOOK TOWARD A DRIER AND NOT AS
DAMP SUNDAY FOR THE AREA.
&&
.AVIATION...FOR MCCARRAN...THE MAIN ISSUE OVERNIGHT WILL BE WITH
CIGS AS OVERALL RADAR TRENDS WOULD ONLY SUPPORT A FEW LIGHT RAIN
SHOWERS IN AND AROUND THE LAS VEGAS VALLEY THROUGH 08Z SUNDAY OR SO.
CIGS INITIALLY SHOULD BE AROUND 4K FEET OR SO...BUT AS SHOWER
ACTIVITY ENDS AND SOME SLIGHT DRYING OF THE LOWER LEVELS OF THE
ATMOSPHERE TAKES PLACE...LOWER CLOUD BASES SHOULD BECOME MORE IN THE
SCT-BKN RANGE AND ANY BKN-OVC CLOUD BASES SHOULD BE MORE IN THE
15-20K FOOT RANGE FOR THE DURATION OF TONIGHT. FURTHER DRYING SHOULD
TAKE PLACE ON SUNDAY WITH MAINLY SCT-BKN CLOUDS AOA 5K-8K FEET.
CLOUDS SHOULD BE EXTENSIVE ALONG THE EDGES OF THE VALLEY WITH
MOUNTAIN OBSCURATIONS LIKELY OVERNIGHT THROUGH 18Z OR SO SUNDAY.
WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS ON SUNDAY AT SPEEDS OF 5
KTS OR LESS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...MAINLY MVFR CIGS TONIGHT WHERE ANY THICKER CLOUD
COVERAGE EXISTS WITH VSBY MAINLY IN THE VFR RANGE AWAY FROM ANY
SHOWERS. LOWER VSBY EXPECTED IN ANY SNOW SHOWERS. SHOWERS SHOULD
DECREASE IN COVERAGE OVERNIGHT AND BE DONE ACROSS ALL AREAS EXCEPT
EASTERN MOHAVE COUNTY BY 18Z SUNDAY AND ANY LINGERING SHOWERS THERE
SHOULD END BY 21Z SUNDAY OR SO. SCT-BKN CLOUDS AOA 5K-8K FEET
OTHERWISE ON SUNDAY WITH VFR VSBY. WINDS OVERALL SHOULD BE 10 KTS OR
LESS WITH SPEEDS TRENDING TOWARDS TYPICAL DIURNAL COMPONENTS OR A
NORTHERLY DIRECTION.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 240 PM PST SAT NOV 23 2013
.DISCUSSION...RAIN AND SNOW CONTINUED ACROSS THE AREA THIS
AFTERNOON AS THE STRONG UPPER LOW WAS MOVING INLAND ALONG THE MEXICO
BORDER. SIX HOUR RAINFALL AMOUNTS ENDING AT 220 PM HAVE BEEN
GENERALLY FROM A TENTH TO A QUARTER OF AN INCH ACROSS CLARK AND
MOHAVE COUNTIES WITH SOMEWHAT LIGHTER AMOUNTS IN MOST OTHER AREAS.
WEB CAMS SHOWED CLOUDS AND SNOWFALL LIFTING IN INYO COUNTY AND THE
WINTER WEATHER ADVISORY WILL BE ALLOWED TO EXPIRE AT 4 PM. THE
ADVISORIES FOR THE SPRING MOUNTAINS AND SHEEP RANGE AND FOR HIGHER
ELEVATIONS OF SOUTHERN MOHAVE COUNTY REMAINS IN EFFECT UNTIL 10 AM
SUNDAY. THE UPPER LOW WILL MOVE INTO ARIZONA LATE TONIGHT WITH
PRECIPITATION CHANCES ENDING IN THE WESTERN PART OF THE FORECAST
AREA WHILE CONTINUING IN THE EAST. I KEPT A MENTION OF FOG IN THE
FORECAST TONIGHT IN SOME AREAS BUT IF CLOUDS DO NOT CLEAR OUT SOME
THE FOG MAY NOT DEVELOP. THE MOST LIKELY PLACES FOR FOG FORMATION
TONIGHT WILL BE IN THE VALLEYS OF INYO COUNTY AND IN WESTERN SAN
BERNARDINO COUNTY. AS THE LOW CENTER MOVES JUST INTO WESTERN NEW
MEXICO LATE SUNDAY...SOME CLEARING WILL DEVELOP WITH PRECIPITATION
ENDING BY THE AFTERNOON EXCEPT FOR PERHAPS MOHAVE COUNTY.
THE MODELS ARE STILL IN GOOD AGREEMENT WITH A RIDGE OF HIGH PRESSURE
TRAVERSING THE AREA MONDAY THROUGH WEDNESDAY LEADING TO DRY
CONDITIONS AND A WARMING TREND. THE MODELS STILL DIFFER IN THE
HANDLING OF THE NEXT UPPER LOW. AT THIS TIME IT LOOKS LIKE IT WILL
PROBABLY MOVE ROUGHLY TO THE CENTRAL CALIFORNIA COAST LATE THURSDAY
WITH PRECIPITATION CHANCES SPREADING ACROSS MAINLY INYO COUNTY.
THERE IS POTENTIAL FOR THE LOW TO MOVE FARTHER INLAND FRIDAY AND I
KEPT A SLIGHT CHANCE OF SHOWERS OVER MOST OF THE FORECAST AREA
EXCEPT MOHAVE COUNTY. CONFIDENCE IS LOW AS THE ECMWF REMAINS MUCH
LESS PROGRESSIVE WITH THE LOW. BY FRIDAY THE LOW MAY HAVE EITHER
WEAKENED SIGNIFICANTLY OR DROPPED OFF SHORE LEADING TO DRY
CONDITIONS OVER OUR FORECAST AREA. AGAIN...CONFIDENCE IS LOW.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 AM PST SUNDAY FOR NVZ018-019.
AZ...WINTER WEATHER ADVISORY UNTIL 11 AM MST SUNDAY FOR AZZ003.
CA...NONE.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...HARRISON
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
917 PM EST MON NOV 25 2013
.SYNOPSIS...
PARTLY TO MOSTLY CLOUDY SKIES ALONG WITH A FEW FLURRIES OR LIGHT
SNOW SHOWERS ARE EXPECTED TONIGHT INTO THE FIRST HALF OF TUESDAY AS
WEAK ENERGY PASSES TO THE NORTH ACROSS SOUTHERN CANADA. A
SIGNIFICANT STORM SYSTEM WILL THEN AFFECT THE AREA TUESDAY NIGHT
INTO THURSDAY MORNING WITH WIDESPREAD...AND POSSIBLY HEAVY MIXED
PRECIPITATION. THIS WILL LIKELY PROVE PROBLEMATIC FOR HOLIDAY TRAVEL
INTERESTS DURING THE PERIOD. SEASONABLY COLD AND MAINLY DRY WEATHER
IS THEN EXPECTED BY FRIDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 915 PM EST MONDAY...FORECAST REMAINS ON TRACK...NO
SIGNIFICANT CHANGES MADE.
PREVIOUS DISCUSSION FROM 652 PM MONDAY...
GOING FORECAST IN GOOD SHAPE. LOW PRESSURE SYSTEM CONTINUES TO
PASS WELL NORTH OF THE AREA...WITH SECONDARY MOISTURE PLUME
PASSING SOUTH. A FEW SNOW SHOWERS REMAIN POSSIBLE
OVERNIGHT...ESPECIALLY ACROSS THE HIGHER TERRAIN. LOCAL WRF MODELS
AND HRRR ALSO HINTING AT A WEAK LAKE EFFECT BAND COMING OFF LAKE
ONTARIO AFTER MIDNIGHT. ANY SNOW ACCUMULATIONS WILL BE LIGHT...A
DUSTING TO ONE INCH. OTHERWISE...CLOUDS AND SOUTHWEST FLOW SHOULD
KEEP TEMPERATURES FAIRLY STEADY FOR THE REMAINDER OF THE
NIGHT...WITH 20S FOR MOST...EXCEPT SOME TEENS IN THE NORTHEAST
KINGDOM.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 345 PM EST MONDAY...BY TOMORROW FOCUS TURNS TO DEEPENING LOW
PRESSURE RIDING NORTHEAST FROM THE SOUTHEASTERN STATES. MODELS
CONTINUE TO SHOW GOOD PHASING OF THIS SYSTEM WITH DIGGING NRN
STREAM UPPER TROUGH AND SEE NO REASON TO DISCOUNT THE IDEA OF A
WIDESPREAD MIXED/WINTRY PCPN EVENT AFFECTING OUR AREA TOMORROW
EVENING INTO WED/WED NT. FIRST SURGE OF WAA-DRIVEN PRECIP SHOULD
FALL IN THE FORM OF MIXED SN/PL/FZRA DEPENDING ON LOCALE TUESDAY
NIGHT AS INITIAL LOWER TO MID LEVEL THERMAL PROFILES ARE AT OR
SLIGHTLY BELOW FREEZING. THE DEVIL IS ALWAYS IN THE DETAILS
HOWEVER AND AS WE PROGRESS INTO WEDNESDAY CONFIDENCE IS HIGH THAT
THERE WILL BE A SUBSTANTIAL WARM AIR SURGE ALONG AND TO THE
IMMEDIATE EAST OF THE PRIMARY LOW TRACK. AT THIS TIME IT APPEARS
THAT THIS WILL BE FROM NYC NNE THROUGH VT AND AS MEAN 925-850 MB
THERMAL PROFILES SURGE INTO THE +5C TO +10C RANGE MUCH OF THE PCPN
SHOULD TRANSITION TO ALL RAIN ACROSS VERMONT DURING THE DAYLIGHT
HOURS ON WEDNESDAY. FURTHER WEST ACROSS THE ADIRONDACKS INTO THE
SLV...COLDER AIR REMAINS MORE OR LESS ENTRENCHED SO CONSIDERABLY
HIGHER CONFIDENCE IN BETTER SNOW/PL ACCUMULATIONS HERE. OTHER
CONCERNS INCLUDE A POTENTIAL SIGNIFICANT HYDRO RESPONSE ACROSS
SOME OF OUR EASTERN VERMONT RIVERS ON WEDNESDAY. MORE OF THAT
BELOW IN THE HYDRO SECTIONS. GIVEN AFOREMENTIONED TIGHT THERMAL
GRADIENTS AND MESOSCALE EFFECTS OF COLDER NEAR-SFC LAYERS ETC HAVE
LEANED HEAVILY ON THE RAW 4KM WRF 2M TEMPS WHICH APPEAR TO CAPTURE
TRENDS THE BEST. SAFE TO SAY QUITE THE NON-DIURNAL TREND IN THOSE
TEMPERATURES THROUGH TIME AS THE LOW TRACKS TOWARD...ATOP...AND
AWAY FROM THE REGION.
BY WEDNESDAY NIGHT...THERMAL PROFILES CRASH SHARPLY AS LOW PULLS
AWAY AND DECENT DEFORMATION AXIS PULLS THROUGH THE AREA...ESP NRN
NY. THUS CONTINUED ACCUMULATING SNOWS IN NY TO SLOWLY TAPER OFF
LATE...AND RAIN TO TRANSITION BACK TO SNOW/SHSN IN VERMONT. OVERALL
HOLIDAY TRAVEL IMPACTS LIKELY WITH THIS EVENT. FOR VERMONT THIS
WOULD LIKELY OCCUR TUE NT WITH INITIAL WINTRY MIX...THEN AGAIN WED
NT AS RAIN TRANSITIONS BACK TO LIGHT/MODERATE ACCUMULATING SNOWS.
IN NY..ESP DACKS/SLV...A HIGHER IMPACT EVENT EXPECTED WITH
SIGNIFICANT WINTRY MIX/ACCUM SNOWS EXPECTED THROUGH THE PERIOD. AS
RESULT OF THE ABOVE THINKING...HAVE UPGRADED WINTER STORM WATCHES
TO WINTER WX ADVISORIES FOR OUR CHAMPLAIN VALLEY AND VT
COUNTIES...AND WINTER STORM WARNINGS FOR OUR ADIRONDACKS/SLV.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 239 PM EST MONDAY...THANKSGIVING...BIG STORM DEPARTED WITH WITH
SOME LEFTOVER MTN -SHSN...BRISK AND COLD WITH WINDS DIMINISHING AS
THE DAY PROGRESSES.
THEREAFTER...RATHER QUIET AS PERSISTENT TROF OF THE PAST WEEK/TWO
GRADUALLY TRANSITIONS INTO ZONAL FLOW. BIG SFC HIGH BUILDS FRI AND
CONTS TO DOMINATE THROUGH THE WEEKEND THEN EXITING LATE SUNDAY AND
MON WITH RETURN FLOW.
IT WILL BE COLD AT THE START WITH A MODERATING TREND WEEKEND AND
BEYOND. PCPN WILL BE SPARSE...WITH SOME SNOW OR SNOW/RAIN SHOWERS
AS A MID LVL DISTURBANCE MOVES THRU MON...OTHERWISE BACK END OF
HOLIDAY TRAVEL SHOULD BE MUCH SMOOTHER THAN THE FRONT END.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
THROUGH 00Z WEDNESDAY...VFR CONDITIONS EXPECTED FOR MOST OF THE
PERIOD BUT VFR CEILINGS WILL GRADUALLY LOWER TONIGHT WITH SOME
SCATTERED SNOW SHOWERS ACROSS NORTHERN NEW YORK AND KRUT.
STEADIER SNOW WITH MVFR CONDITIONS ARRIVES KRUT/KSLK AFTER 22Z
TUESDAY BUT NOT TILL AFTER 00Z WEDNESDAY AT REST OF SITES.
WINDS SOUTH TO SOUTHWEST WITH SPEEDS AROUND 10 KNOTS AND SOME
GUSTS TO 20 KNOTS AT KMSS/KBTV OVERNIGHT INTO TUESDAY MORNING.
OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY...
00Z WEDNESDAY THROUGH 18Z THURSDAY...CONDITIONS LOWER INTO THE
MVFR AND IFR CATEGORIES TUESDAY NIGHT AND CONTINUE INTO THANKSGIVING
MORNING. SNOW DEVELOPS TUESDAY EVENING...WITH MIXED PRECIPITATION
LATE TUESDAY NIGHT CHANGING TO RAIN WEDNESDAY AT ALL TERMINALS
EXCEPT KMSS/KSLK. PRECIPITATION CHANGES BACK TO SNOW WEDNESDAY NIGHT
AND TAPERS TO SNOW SHOWERS THURSDAY MORNING. CEILINGS AND
VISIBILITIES WILL MOVE BACK INTO THE MVFR AND VFR CATEGORIES
BY 18Z THURSDAY AS SNOW SHOWERS COME TO AN END.
18Z THURSDAY ONWARD...MAINLY VFR AS HIGH PRESSURE BUILD INTO REGION.
&&
.HYDROLOGY...
AS OF 345 PM EST MONDAY...SREF MEAN AND PLUME OUTPUT ALONG WITH
GLOBAL BLENDED SOLUTIONS ALL SUGGEST A DECENT QPF EVENT ACROSS OUR
AREA. HEAVIEST PCPN SHOULD FALL ACROSS OUR EASTERN AND SOUTHERN VT
COUNTIES WHERE WIDESPREAD 24-HOUR TOTALS SHOULD RANGE FROM 1.5 TO
2.5 INCHES. WHILE SOME OF THIS WILL OCCUR IN THE FROZEN
FORM...MUCH WILL FALL AS LIQUID WITH WATERSHEDS RECEIVING SOME
ADDITIONAL INPUT FROM MODEST HIGHER ELEVATION SNOWMELT. AS A
RESULT...SUBSTANTIAL WITHIN BANK RISES ARE LIKELY ACROSS MANY
EASTERN/SOUTHERN VT WATERSHEDS INCLUDING THE PASSUMPSIC...WELLS
AND THE WHITE. IF TRENDS CONTINUE...FLOOD WATCHES MAY BE NEEDED
FOR PORTIONS OF THIS AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.MARINE...
AS OF 318 PM EST MONDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT FOR
TONIGHT THROUGH TUESDAY MORNING. SOUTHERLY WINDS ON THE BROAD LAKE
HAVE BEEN STEADILY INCREASING THROUGH THE DAY...AND WILL CONTINUE TO
INCREASE ABOVE ADVISORY LIMITS THIS EVENING AND OVERNIGHT. GENERAL
WIND SPEEDS OF 15 TO 25 KNOTS ARE EXPECTED THROUGH TUESDAY MORNING
WITH PEAK WINDS OF 20 TO 35 KNOTS LIKELY DURING A 3 HOUR WINDOW
AROUND 8 PM THIS EVENING. WINDS SPEEDS OF THIS MAGNITUDE WILL
RESULT IN GENERAL WAVE HEIGHTS OF 2 TO 4 FEET...WITH SOME 3 TO 5
FOOTERS POSSIBLE DURING THE PEAK WINDS. WINDS DECREASE BELOW 20
KNOTS TUESDAY AFTERNOON AS PRECIPITATION IN THE FORM OF RAIN AND
SNOW MOVES IN FROM THE SOUTH/SOUTHWEST.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY FROM 5 PM TUESDAY TO 7 AM EST
WEDNESDAY FOR VTZ001>012-016>019.
NY...WINTER STORM WARNING FROM 5 PM TUESDAY TO 7 AM EST THURSDAY
FOR NYZ026-027-029>031-034-087.
WINTER WEATHER ADVISORY FROM 5 PM TUESDAY TO 7 AM EST
WEDNESDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...MUCCILLI
SHORT TERM...JMG
LONG TERM...SLW
AVIATION...RJS
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
658 PM EST MON NOV 25 2013
.SYNOPSIS...
PARTLY TO MOSTLY CLOUDY SKIES ALONG WITH A FEW FLURRIES OR LIGHT
SNOW SHOWERS ARE EXPECTED TONIGHT INTO THE FIRST HALF OF TUESDAY AS
WEAK ENERGY PASSES TO THE NORTH ACROSS SOUTHERN CANADA. A
SIGNIFICANT STORM SYSTEM WILL THEN AFFECT THE AREA TUESDAY NIGHT
INTO THURSDAY MORNING WITH WIDESPREAD...AND POSSIBLY HEAVY MIXED
PRECIPITATION. THIS WILL LIKELY PROVE PROBLEMATIC FOR HOLIDAY TRAVEL
INTERESTS DURING THE PERIOD. SEASONABLY COLD AND MAINLY DRY WEATHER
IS THEN EXPECTED BY FRIDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 652 PM EST MONDAY...GOING FORECAST IN GOOD SHAPE. LOW
PRESSURE SYSTEM CONTINUES TO PASS WELL NORTH OF THE AREA...WITH
SECONDARY MOISTURE PLUME PASSING SOUTH. A FEW SNOW SHOWERS REMAIN
POSSIBLE OVERNIGHT...ESPECIALLY ACROSS THE HIGHER TERRAIN. LOCAL
WRF MODELS AND HRRR ALSO HINTING AT A WEAK LAKE EFFECT BAND COMING
OFF LAKE ONTARIO AFTER MIDNIGHT. ANY SNOW ACCUMULATIONS WILL BE
LIGHT...A DUSTING TO ONE INCH. OTHERWISE...CLOUDS AND SOUTHWEST
FLOW SHOULD KEEP TEMPERATURES FAIRLY STEADY FOR THE REMAINDER OF
THE NIGHT...WITH 20S FOR MOST...EXCEPT TEENS IN THE NORTHEAST
KINGDOM.
PREVIOUS DISCUSSION FROM 345 PM MONDAY...
FORECAST REMAINS ON TRACK AS WE HEAD INTO THE EVENING AND
OVERNIGHT HOURS AND ONLY SMALL ADJUSTMENTS WERE NEEDED FOR THE
FIRST 12 HOURS OF THE FORECAST...MAINLY TO INCORPORATE MOST RECENT
MODEL TRENDS IN SKY COVER AND TEMPERATURES. SOLUTIONS PAINT A
SIMILAR STORY...SHOWING NORTHERN STREAM CLIPPER ENERGY PASSING
WELL NORTH OF OUR REGION OVERNIGHT. THIS SYSTEM WILL SPREAD PLENTY
OF MID TO UPPER LEVEL CLOUD COVER ACROSS THE AREA OVER TIME...BUT
DYNAMICAL FORCING FOR PRECIPITATION IS FAIRLY WEAK AND WITH SUCH
DRY LOWER LEVELS...IT`S HARD TO SEE MUCH IN THE WAY OF ORGANIZED
ACTIVITY OCCURRING WITH THIS SYSTEM. THUS WILL CONTINUE THE IDEA
OF A FEW/SCT FLURRIES AND/OR SHSN OVERNIGHT THOUGH MAINLY ACROSS
NRN NY/NRN MTN LOCALES. ACCUMULATIONS LIGHT AT BEST...PERHAPS A
LOCALIZED INCH OR TWO ABOVE 1500 FEET IN FAVORED LOCALES.
CHAMPLAIN/CT RVR VALLEYS MAINLY DRY. WITH DEEPENING SOUTH TO
SOUTHWESTERLY FLOW TEMPERATURES WILL EXHIBIT CLASSIC NON-DIURNAL
TRENDS...ESPECIALLY FROM THE CHAMPLAIN VALLEY WESTWARD WHICH IS
TYPICAL UNDER NOCTURNAL RETURN FLOW EVENTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 345 PM EST MONDAY...BY TOMORROW FOCUS TURNS TO DEEPENING LOW
PRESSURE RIDING NORTHEAST FROM THE SOUTHEASTERN STATES. MODELS
CONTINUE TO SHOW GOOD PHASING OF THIS SYSTEM WITH DIGGING NRN
STREAM UPPER TROUGH AND SEE NO REASON TO DISCOUNT THE IDEA OF A
WIDESPREAD MIXED/WINTRY PCPN EVENT AFFECTING OUR AREA TOMORROW
EVENING INTO WED/WED NT. FIRST SURGE OF WAA-DRIVEN PRECIP SHOULD
FALL IN THE FORM OF MIXED SN/PL/FZRA DEPENDING ON LOCALE TUESDAY
NIGHT AS INITIAL LOWER TO MID LEVEL THERMAL PROFILES ARE AT OR
SLIGHTLY BELOW FREEZING. THE DEVIL IS ALWAYS IN THE DETAILS
HOWEVER AND AS WE PROGRESS INTO WEDNESDAY CONFIDENCE IS HIGH THAT
THERE WILL BE A SUBSTANTIAL WARM AIR SURGE ALONG AND TO THE
IMMEDIATE EAST OF THE PRIMARY LOW TRACK. AT THIS TIME IT APPEARS
THAT THIS WILL BE FROM NYC NNE THROUGH VT AND AS MEAN 925-850 MB
THERMAL PROFILES SURGE INTO THE +5C TO +10C RANGE MUCH OF THE PCPN
SHOULD TRANSITION TO ALL RAIN ACROSS VERMONT DURING THE DAYLIGHT
HOURS ON WEDNESDAY. FURTHER WEST ACROSS THE ADIRONDACKS INTO THE
SLV...COLDER AIR REMAINS MORE OR LESS ENTRENCHED SO CONSIDERABLY
HIGHER CONFIDENCE IN BETTER SNOW/PL ACCUMULATIONS HERE. OTHER
CONCERNS INCLUDE A POTENTIAL SIGNIFICANT HYDRO RESPONSE ACROSS
SOME OF OUR EASTERN VERMONT RIVERS ON WEDNESDAY. MORE OF THAT
BELOW IN THE HYDRO SECTIONS. GIVEN AFOREMENTIONED TIGHT THERMAL
GRADIENTS AND MESOSCALE EFFECTS OF COLDER NEAR-SFC LAYERS ETC HAVE
LEANED HEAVILY ON THE RAW 4KM WRF 2M TEMPS WHICH APPEAR TO CAPTURE
TRENDS THE BEST. SAFE TO SAY QUITE THE NON-DIURNAL TREND IN THOSE
TEMPERATURES THROUGH TIME AS THE LOW TRACKS TOWARD...ATOP...AND
AWAY FROM THE REGION.
BY WEDNESDAY NIGHT...THERMAL PROFILES CRASH SHARPLY AS LOW PULLS
AWAY AND DECENT DEFORMATION AXIS PULLS THROUGH THE AREA...ESP NRN
NY. THUS CONTINUED ACCUMULATING SNOWS IN NY TO SLOWLY TAPER OFF
LATE...AND RAIN TO TRANSITION BACK TO SNOW/SHSN IN VERMONT. OVERALL
HOLIDAY TRAVEL IMPACTS LIKELY WITH THIS EVENT. FOR VERMONT THIS
WOULD LIKELY OCCUR TUE NT WITH INITIAL WINTRY MIX...THEN AGAIN WED
NT AS RAIN TRANSITIONS BACK TO LIGHT/MODERATE ACCUMULATING SNOWS.
IN NY..ESP DACKS/SLV...A HIGHER IMPACT EVENT EXPECTED WITH
SIGNIFICANT WINTRY MIX/ACCUM SNOWS EXPECTED THROUGH THE PERIOD. AS
RESULT OF THE ABOVE THINKING...HAVE UPGRADED WINTER STORM WATCHES
TO WINTER WX ADVISORIES FOR OUR CHAMPLAIN VALLEY AND VT
COUNTIES...AND WINTER STORM WARNINGS FOR OUR ADIRONDACKS/SLV.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 239 PM EST MONDAY...THANKSGIVING...BIG STORM DEPARTED WITH WITH
SOME LEFTOVER MTN -SHSN...BRISK AND COLD WITH WINDS DIMINISHING AS
THE DAY PROGRESSES.
THEREAFTER...RATHER QUIET AS PERSISTENT TROF OF THE PAST WEEK/TWO
GRADUALLY TRANSITIONS INTO ZONAL FLOW. BIG SFC HIGH BUILDS FRI AND
CONTS TO DOMINATE THROUGH THE WEEKEND THEN EXITING LATE SUNDAY AND
MON WITH RETURN FLOW.
IT WILL BE COLD AT THE START WITH A MODERATING TREND WEEKEND AND
BEYOND. PCPN WILL BE SPARSE...WITH SOME SNOW OR SNOW/RAIN SHOWERS
AS A MID LVL DISTURBANCE MOVES THRU MON...OTHERWISE BACK END OF
HOLIDAY TRAVEL SHOULD BE MUCH SMOOTHER THAN THE FRONT END.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THROUGH 00Z WEDNESDAY...VFR CONDITIONS EXPECTED FOR MOST OF THE
PERIOD BUT VFR CEILINGS WILL GRADUALLY LOWER TONIGHT WITH SOME
SCATTERED SNOW SHOWERS ACROSS NORTHERN NEW YORK AND KRUT.
STEADIER SNOW WITH MVFR CONDITIONS ARRIVES KRUT/KSLK AFTER 22Z
TUESDAY BUT NOT TILL AFTER 00Z WEDNESDAY AT REST OF SITES.
WINDS SOUTH TO SOUTHWEST WITH SPEEDS AROUND 10 KNOTS AND SOME
GUSTS TO 20 KNOTS AT KMSS/KBTV OVERNIGHT INTO TUESDAY MORNING.
OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY...
00Z WEDNESDAY THROUGH 18Z THURSDAY...CONDITIONS LOWER INTO THE
MVFR AND IFR CATEGORIES TUESDAY NIGHT AND CONTINUE INTO THANKSGIVING
MORNING. SNOW DEVELOPS TUESDAY EVENING...WITH MIXED PRECIPITATION
LATE TUESDAY NIGHT CHANGING TO RAIN WEDNESDAY AT ALL TERMINALS
EXCEPT KMSS/KSLK. PRECIPITATION CHANGES BACK TO SNOW WEDNESDAY NIGHT
AND TAPERS TO SNOW SHOWERS THURSDAY MORNING. CEILINGS AND
VISIBILITIES WILL MOVE BACK INTO THE MVFR AND VFR CATEGORIES
BY 18Z THURSDAY AS SNOW SHOWERS COME TO AN END.
18Z THURSDAY ONWARD...MAINLY VFR AS HIGH PRESSURE BUILD INTO REGION.
&&
.HYDROLOGY...
AS OF 345 PM EST MONDAY...SREF MEAN AND PLUME OUTPUT ALONG WITH
GLOBAL BLENDED SOLUTIONS ALL SUGGEST A DECENT QPF EVENT ACROSS OUR
AREA. HEAVIEST PCPN SHOULD FALL ACROSS OUR EASTERN AND SOUTHERN VT
COUNTIES WHERE WIDESPREAD 24-HOUR TOTALS SHOULD RANGE FROM 1.5 TO
2.5 INCHES. WHILE SOME OF THIS WILL OCCUR IN THE FROZEN
FORM...MUCH WILL FALL AS LIQUID WITH WATERSHEDS RECEIVING SOME
ADDITIONAL INPUT FROM MODEST HIGHER ELEVATION SNOWMELT. AS A
RESULT...SUBSTANTIAL WITHIN BANK RISES ARE LIKELY ACROSS MANY
EASTERN/SOUTHERN VT WATERSHEDS INCLUDING THE PASSUMPSIC...WELLS
AND THE WHITE. IF TRENDS CONTINUE...FLOOD WATCHES MAY BE NEEDED
FOR PORTIONS OF THIS AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.MARINE...
AS OF 318 PM EST MONDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT FOR
TONIGHT THROUGH TUESDAY MORNING. SOUTHERLY WINDS ON THE BROAD LAKE
HAVE BEEN STEADILY INCREASING THROUGH THE DAY...AND WILL CONTINUE TO
INCREASE ABOVE ADVISORY LIMITS THIS EVENING AND OVERNIGHT. GENERAL
WIND SPEEDS OF 15 TO 25 KNOTS ARE EXPECTED THROUGH TUESDAY MORNING
WITH PEAK WINDS OF 20 TO 35 KNOTS LIKELY DURING A 3 HOUR WINDOW
AROUND 8 PM THIS EVENING. WINDS SPEEDS OF THIS MAGNITUDE WILL
RESULT IN GENERAL WAVE HEIGHTS OF 2 TO 4 FEET...WITH SOME 3 TO 5
FOOTERS POSSIBLE DURING THE PEAK WINDS. WINDS DECREASE BELOW 20
KNOTS TUESDAY AFTERNOON AS PRECIPITATION IN THE FORM OF RAIN AND
SNOW MOVES IN FROM THE SOUTH/SOUTHWEST.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY FROM 5 PM TUESDAY TO 7 AM EST
WEDNESDAY FOR VTZ001>012-016>019.
NY...WINTER STORM WARNING FROM 5 PM TUESDAY TO 7 AM EST THURSDAY
FOR NYZ026-027-029>031-034-087.
WINTER WEATHER ADVISORY FROM 5 PM TUESDAY TO 7 AM EST
WEDNESDAY FOR NYZ028-035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/MUCCILLI
SHORT TERM...JMG
LONG TERM...SLW
AVIATION...RJS
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
211 PM EST SUN NOV 24 2013
.SYNOPSIS...
THE NORTH COUNTRY WILL REMAIN UNDER COLD NORTHWESTERLY FLOW FOR
TODAY AND TONIGHT...AS LOW PRESSURE REMAINS TO OUR EAST AND HIGH
PRESSURE OFF TO OUR WEST. THAT AREA OF HIGH PRESSURE WILL SHIFT
EAST OVER THE REGION LATER TONIGHT...FOLLOWED BY ANOTHER LOW FOR
MONDAY AFTERNOON INTO TUESDAY. THERE IS THE POTENTIAL FOR A WINTER
STORM TO AFFECT THE REGION STARTING LATE TUESDAY NIGHT AND INTO
WEDNESDAY NIGHT. HIGH PRESSURE SLOWLY RETURNS FOR THURSDAY INTO
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 931 AM EST SUNDAY...HAVE UPDATED THE FORECAST TO RAISE POPS
ACROSS MUCH OF NC/NE VT THROUGH THE DAY...AND TO INTRODUCE AREAS
OF BLOWING SNOW IN THESE AREAS. ALSO LOWERED HOURLY AND MAX
TEMPERATURES BY A FEW DEGREES BASED OFF CURRENT OBSERVATIONAL DATA
AND LATEST LAMP GUIDANCE NUMBERS. COLD DAY ON TAP WITH STRONG AND
GUSTY NORTHWESTERLY FLOW CONTINUING. THUS WIND ADVISORIES REMAIN
IN PLACE...ESP ACROSS THE HIGHER TERRAIN AND DOWNSLOPE LOCATIONS
ALONG THE EASTERN SLOPES OF THE DACKS/GREENS. STRONGEST GUSTS
LIKELY THIS AFTERNOON WHEN SECONDARY PRESSURE SURGE PUSHES SOUTH
INTO THE REGION. GUSTS IN ADVISORY LOCATIONS IN THE 35 TO 45 MPH
RANGE WITH LOCALLY HIGHER GUSTS...SLIGHTLY LESS ELSEWHERE. WHILE
MOISTURE CONTINUES TO SLOWLY THIN...LINGERING WRAP- AROUND
OROGRAPHICALLY ENHANCED SHSN CONTINUE ACROSS THE NRN MTNS WHERE
SOME MINOR ADDITIONAL ACCUMULATIONS WILL BE POSSIBLE TODAY. THIS
IS IN CLOSE AGREEMENT WITH LATEST 12/13Z RAP PROGS WHICH HAVE A
GOOD HANDLE ON THE CURRENT SITUATION. THUS WILL LEAN IN ITS
DIRECTION ACCORDINGLY. WITH DEEPLY MIXED PBL...FROUDE NUMBERS
QUITE HIGH SO BEST COVERAGE OF SHSN/ACCUMS FROM THE GREEN MTN
SPINE EASTWARD. TEMPERATURES REALLY GOING NOWHERE WITH SUCH STRONG
CAA IN PLACE...SO READINGS HOLDING MORE OR LESS STEADY...PERHAPS
CLIMBING A DEGREE OR TWO WILL BE ALL WE GET TODAY. WITH THE
AFORMENTIONED WINDS THE APPARENT TEMPS SHOULD RANGE IN THE -10F TO
+5F RANGE...COLDER TO NEAR -20F AT THE SUMMITS. DEFINITELY A DAY
TO WEAR THE FULL WINTER CLOTHING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
AS OF 352 AM EST SUNDAY...TONIGHT WITH RIDGE APPROACHING AND WINDS
ABATING...TEMPS WILL DROP SHARPLY TO LOWEST OF THE SEASON SO FAR
WITH LOWS RANGING FROM -5 TO 10F IN DACKS TO SINGLE NUMBERS
ELSEWHERE. WIND ADVISORY REMAINS IN AFFECT THRU TNGT AS TIGHT
GRADIENT CREATING STEADY 15-30 MPH WINDS WITH GUSTS
40-50MPH...HIGHEST OVER DACKS AND E VT. BY 00Z MONDAY...GRADIENT
WILL SLACKEN AND TAPER OFF BY MIDNGT WITH ARRIVAL OF SFC RIDGE.
WIND CHILL ISSUES POSSIBLE IN RANGE OF 0F TO -10F.
COLD CHILLY MORNING ON MONDAY W/ RIDGE CRESTING OVER THE AREA AND
SLIDING S AND E DURING THE DAY. THIS WILL ALLOW WAA ON SSW FLOW TO
SETUP OVER THE AREA...AND PROVIDE A NICE REBOUND IN TEMPS FROM THE
COLD WEEKEND. WAA WILL BRING HIGHS MONDAY INTO THE 20S FOR ALL
SITES. INCR CLDS THOUGH OVER N NY AS NORTHERN STREAM SYSTEM COMES
OUT OF THE GREAT LKS REGION AND INTO QUEBEC MON AFTNOON/TUESDAY
MORNING. BLOCKING RIDGE TO OUR SOUTH WILL PUT BEST POP FOCUS OVER
N NY TAPERING DOWN TO SE VT. ADDITIONAL LIGHT SNOWFALL WILL OCCUR
BRINGING AROUND AN INCH OF NEW SNOW TAPERING OFF TO A POTENTIAL
DUSTING IN SOUTHERN ZONES. CLD COVER KEEPS TEMPS FROM DROPPING TOO
MUCH ALONG WITH GRADIENT STAYING SW. LOOKING FOR LOWS IN THE TEENS
TO L20S. GOING INTO TUESDAY SW GRADIENT STAYS INTACT FOR THE DAY
AS NORTHERN SYSTEM...THAT COULD BRING STORM NEAR
THANKSGIVING...SWINGS THRU THE GREAT LKS. CLDS/MOISTURE FEED WILL
ALLOW FOR SL CHANCE OF -SW WITH FOCUS OVER SOUTHERN ZONES. OVERALL
INCH OR LESS EXPECTED...WITH HIGHS IN THE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 209 PM EST SUNDAY...INALLY SOME CONSENSUS IN ALL MAJOR
MODELS WITH THE 12Z GFS BEING THE LATECOMER TO THE PARTY FOR THIS
MID WEEK...HOLIDAY TRAVEL STORM.
THE SHORT TERM DISCUSSION TOUCHES UPON ALOT OF THE EVOLVING SYSTEM
BUT THE CURRENT WED FCST IS BASED ON A GFS/ECMWF/NAM TRACK OF
NYC-ORH-CON. CNDN GEM IS MORE HUDSON/CHAMPLAIN VLY BUT ERRING TO A
SLIGHTLY COLDER...MORE PROBLEMATIC SOLUTION.
IN GENERAL...A SNOW/MIXED START WITH GRADUAL CHANGEOVER TO
MIXED/RAIN IN VT AND CHMPL VLY NY WITH SOME POSSIBLE ACCUMULATING
SNOW AND A FLASH FREEZE MARCHING FROM WEST TO EAST AFT SFC LOW
PASSAGE WED EVE/WED NGT. ADRNDKS/ST LWRNC VLY IN THE POTENTIAL
SWEET-SPOT FOR HEAVY SNOWFALL ALONG WITH SOME MIXING.
QPF AMOUNTS OF 1-2 INCHES ACROSS MUCH OF THE FA...LIGHTER SIDE ACRS
ST LWRNC VLY WHERE IT WILL STAY COLDEST. WPC WINTER WX GRAPHIC
PLACES 6-12 INCHES IN ADRNDKS/ST LWRNC VLY AND QUITE POSSIBLE. LLVL
NNE JET ACRS ST LWRNV VLY WILL ADD PROBLEMS WITH CONSIDERABLE
BLOWING SNOW.
LLVL TEMP PROFILES AND SHARP GRADIENT LEADS TO CONCERNS OF ICING IN
INTERIOR VT AND CT RVR VLY DUE TO STG INVERSIONS. IN ADDITION...A
NNE LLVL FLOW IN ST LWRNC VLY THAT MAY ADVECT LLVL COLD AIR TOWARD
NRN CHAMPL VLY FOR A WINTRY MIX.
AGAIN...LATE WED/WED NGT AS SFC LOW DEPARTS STG CAA AND WRAPARD PCPN
CHANGING TO SNOW AND FALLING TMPS WILL LIKELY RESULT IN A FLASH
FREEZE SITUATION ON ROADS...TREES AND UTILITY LINES AND WITH NNW
WINDS INCREASING TO 20-30KTS PSBLY BLOWING SNOW AND POWER OUTAGES.
THANKSGIVING...BLUSTERY AND LEFTOVER MTN SNOW SHOWERS BUT COLD
THROUGHOUT THE DAY.
THEREAFTER...CONTINUED BELOW NORMAL TEMPERATURES (10-15 DEGS BLO)
CONTINUE THROUGH THE WEEKEND WITH REINFORCING SHOTS OF COLD AIR AND
CHC OF FLURRIES.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...STRONG W-NW WINDS WILL CONTINUE INTO THIS
EVENING. SNOW SHOWER ACTIVITY IS GRADUALLY DECREASING WITH DRIER
AIR MOVING IN...BUT PERIODS OF IFR AT KMPV DUE TO BLOWING SNOW.
ELSEWHERE...VFR WITH CLRG SKIES BY AND DURING THE EVENING.
KBTV/KMPV WILL SEE WNW WINDS 20G35KTS THRU 00Z MON...ELSEWHERE
WILL BE 15-18G28KTS ALL DIMINISHING AFT 04Z.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...DRY AND MOSTLY CLEAR VFR WITH
HIGH PRESSURE IN PLACE MONDAY. THERE WILL BE A CHANCE FOR MVFR
CIGS/VIS IN SNOW SHOWERS MONDAY NIGHT AND TUESDAY AS WEAK UPPER
LEVEL TROUGH MOVES ACROSS THE NORTH COUNTRY. MODERATE TO HIGH PREDICTABILITY
FOR WEDNESDAY WITH INCREASING CONFIDENCE OF STORM TRACK WITHIN 50
MILES OF A KLGA-KBDL-KORH-KCON LINE. POSSIBILITY EXISTS FOR IFR
CONDITIONS WITH ACCUMULATING SNOWFALL AND MIXED WEDNESDAY BUT DETAILS
ARE UNCERTAIN. THURSDAY...MODERATE N-NW WINDS WITH ISOLD -SHSN
POSSIBLE...MAINLY VCNTY MTNS. TAF LOCATIONS SHOULD BE MAINLY VFR
FOR THURSDAY.
&&
.MARINE...
AS OF 352 AM EST SUNDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
AND WILL LIKELY REMAIN SO THROUGH TONIGHT. WINDS NORTHWEST 20 TO
30 KNOTS...TAPERING TO 15 TO 25 KNOTS TONIGHT. WAVES WILL BUILD TO
3-5 FEET IMPACTING NORTH-FACING EXPOSURES.
&&
.CLIMATE...
THE COLD TEMPERATURES SUNDAY 11/24 INTO MONDAY 11/25 MAY APPROACH
RECORD LEVELS. THE RECORDS ARE LISTED BELOW:
RECORD LOW AND RECORD LOW MAXIMUMS SUNDAY 11/24:
BURLINGTON (BTV)- 2 (1956), 19 (1938)
MONTPELIER (MPV)- -4 (1989), 20 (2000)
MASSENA (MSS)- -8 (2000), 19 (1996)
SAINT JOHNSBURY (SJBV1)- -6 (1989), 20 (1921)
RECORD LOW AND RECORD LOW MAXIMUMS MONDAY 11/25:
BURLINGTON (BTV)- -1 (1938), 14 (1938)
MONTPELIER (MPV)- 4 (1997,1993), 24 (1993,1971)
MASSENA (MSS)- 5 (2005), 23 (1993)
SAINT JOHNSBURY (SJBV1)- 0 (1956), 19 (1938)
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR VTZ003-004-
006>008-010-012-016>019.
NY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ028-031-034-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...SLW
AVIATION...BANACOS/SLW
MARINE...LOCONTO
CLIMATE...MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1232 PM EST SUN NOV 24 2013
.SYNOPSIS...
THE NORTH COUNTRY WILL REMAIN UNDER COLD NORTHWESTERLY FLOW FOR
TODAY AND TONIGHT...AS LOW PRESSURE REMAINS TO OUR EAST AND HIGH
PRESSURE OFF TO OUR WEST. THAT AREA OF HIGH PRESSURE WILL SHIFT
EAST OVER THE REGION LATER TONIGHT...FOLLOWED BY ANOTHER LOW FOR
MONDAY AFTERNOON INTO TUESDAY. THERE IS THE POTENTIAL FOR A WINTER
STORM TO AFFECT THE REGION STARTING LATE TUESDAY NIGHT AND INTO
WEDNESDAY NIGHT. HIGH PRESSURE SLOWLY RETURNS FOR THURSDAY INTO
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 931 AM EST SUNDAY...HAVE UPDATED THE FORECAST TO RAISE POPS
ACROSS MUCH OF NC/NE VT THROUGH THE DAY...AND TO INTRODUCE AREAS
OF BLOWING SNOW IN THESE AREAS. ALSO LOWERED HOURLY AND MAX
TEMPERATURES BY A FEW DEGREES BASED OFF CURRENT OBSERVATIONAL DATA
AND LATEST LAMP GUIDANCE NUMBERS. COLD DAY ON TAP WITH STRONG AND
GUSTY NORTHWESTERLY FLOW CONTINUING. THUS WIND ADVISORIES REMAIN
IN PLACE...ESP ACROSS THE HIGHER TERRAIN AND DOWNSLOPE LOCATIONS
ALONG THE EASTERN SLOPES OF THE DACKS/GREENS. STRONGEST GUSTS
LIKELY THIS AFTERNOON WHEN SECONDARY PRESSURE SURGE PUSHES SOUTH
INTO THE REGION. GUSTS IN ADVISORY LOCATIONS IN THE 35 TO 45 MPH
RANGE WITH LOCALLY HIGHER GUSTS...SLIGHTLY LESS ELSEWHERE. WHILE
MOISTURE CONTINUES TO SLOWLY THIN...LINGERING WRAP- AROUND
OROGRAPHICALLY ENHANCED SHSN CONTINUE ACROSS THE NRN MTNS WHERE
SOME MINOR ADDITIONAL ACCUMULATIONS WILL BE POSSIBLE TODAY. THIS
IS IN CLOSE AGREEMENT WITH LATEST 12/13Z RAP PROGS WHICH HAVE A
GOOD HANDLE ON THE CURRENT SITUATION. THUS WILL LEAN IN ITS
DIRECTION ACCORDINGLY. WITH DEEPLY MIXED PBL...FROUDE NUMBERS
QUITE HIGH SO BEST COVERAGE OF SHSN/ACCUMS FROM THE GREEN MTN
SPINE EASTWARD. TEMPERATURES REALLY GOING NOWHERE WITH SUCH STRONG
CAA IN PLACE...SO READINGS HOLDING MORE OR LESS STEADY...PERHAPS
CLIMBING A DEGREE OR TWO WILL BE ALL WE GET TODAY. WITH THE
AFORMENTIONED WINDS THE APPARENT TEMPS SHOULD RANGE IN THE -10F TO
+5F RANGE...COLDER TO NEAR -20F AT THE SUMMITS. DEFINITELY A DAY
TO WEAR THE FULL WINTER CLOTHING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 352 AM EST SUNDAY...TONIGHT WITH RIDGE APPROACHING AND WINDS
ABATING...TEMPS WILL DROP SHARPLY TO LOWEST OF THE SEASON SO FAR
WITH LOWS RANGING FROM -5 TO 10F IN DACKS TO SINGLE NUMBERS
ELSEWHERE. WIND ADVISORY REMAINS IN AFFECT THRU TNGT AS TIGHT
GRADIENT CREATING STEADY 15-30 MPH WINDS WITH GUSTS
40-50MPH...HIGHEST OVER DACKS AND E VT. BY 00Z MONDAY...GRADIENT
WILL SLACKEN AND TAPER OFF BY MIDNGT WITH ARRIVAL OF SFC RIDGE.
WIND CHILL ISSUES POSSIBLE IN RANGE OF 0F TO -10F.
COLD CHILLY MORNING ON MONDAY W/ RIDGE CRESTING OVER THE AREA AND
SLIDING S AND E DURING THE DAY. THIS WILL ALLOW WAA ON SSW FLOW TO
SETUP OVER THE AREA...AND PROVIDE A NICE REBOUND IN TEMPS FROM THE
COLD WEEKEND. WAA WILL BRING HIGHS MONDAY INTO THE 20S FOR ALL
SITES. INCR CLDS THOUGH OVER N NY AS NORTHERN STREAM SYSTEM COMES
OUT OF THE GREAT LKS REGION AND INTO QUEBEC MON AFTNOON/TUESDAY
MORNING. BLOCKING RIDGE TO OUR SOUTH WILL PUT BEST POP FOCUS OVER
N NY TAPERING DOWN TO SE VT. ADDITIONAL LIGHT SNOWFALL WILL OCCUR
BRINGING AROUND AN INCH OF NEW SNOW TAPERING OFF TO A POTENTIAL
DUSTING IN SOUTHERN ZONES. CLD COVER KEEPS TEMPS FROM DROPPING TOO
MUCH ALONG WITH GRADIENT STAYING SW. LOOKING FOR LOWS IN THE TEENS
TO L20S. GOING INTO TUESDAY SW GRADIENT STAYS INTACT FOR THE DAY
AS NORTHERN SYSTEM...THAT COULD BRING STORM NEAR
THANKSGIVING...SWINGS THRU THE GREAT LKS. CLDS/MOISTURE FEED WILL
ALLOW FOR SL CHANCE OF -SW WITH FOCUS OVER SOUTHERN ZONES. OVERALL
INCH OR LESS EXPECTED...WITH HIGHS IN THE 30S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 640 AM EST SUNDAY...STILL CONSIDERABLE MODEL DIFFERENCES
CONCERNING MOISTURE-LADEN SYNOPTIC LOW EXPECTED TO AFFECT THE
NORTH COUNTRY TUESDAY NIGHT INTO WEDNESDAY...WHICH UNFORTUNATELY
COINCIDES WITH ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR. THE 00Z
NWP DIFFERENCES CONTINUE TO SURROUND INTERACTION BETWEEN VIGOROUS
BUT DISTINCT NRN AND SRN STREAM SHORTWAVE TROUGHS AS SYSTEMS CROSS
THE OHIO VALLEY AND SERN STATES...RESPECTIVELY. THE DEEPER AND
MORE PHASED SOLN OFFERED BY THE 00Z ECMWF TAKES THE LOW INLAND UP
THE EAST COAST AND ULTIMATELY TRACKS A 986MB LOW ACROSS VT BETWEEN
18Z WED AND 00Z THU. THIS IS A WARMER SOLN WITH 850MB TEMPS
REACHING +8C ACROSS VT AT 18Z WEDNESDAY. ANY SNOW AT THE ONSET TUESDAY
NIGHT WOULD SWITCH OVER TO MAINLY RAIN ACROSS THE REGION.
MEANWHILE...THE 00Z GFS CONTINUES THAT MODEL/S TENDENCY TO KEEP A
FASTER MOVING SYSTEM OFFSHORE BETWEEN THE 40N 70W BENCHMARK AND
CAPE COD WITH A 994MB LOW MOVING THROUGH AT 18Z WEDNESDAY. THIS IS
A MUCH COLDER SOLN...WITH POTENTIAL ACCUMULATING SNOW ACROSS VT
AND LESS PRECIPITATION IMPACT FOR NRN NY. HAVE INCREASED POPS TO
70-80 PERCENT LATE TUESDAY THROUGH WEDNESDAY ASSOCIATED WITH THIS
SYSTEM WITH QPF ON THE ORDER OF 1"...BUT IT REMAINS TOO SOON TO
DETERMINE P-TYPE DETAILS GIVEN UNCERTAIN EVOLUTION/PHASING OF NRN
AND SRN STREAMS. THOSE WITH TRAVEL PLANS WEDNESDAY SHOULD CONSIDER
PROSPECT FOR WINTER TRAVEL CONDITIONS ACROSS THE NORTH
COUNTRY...BUT THAT IS BY NO MEANS A SURE THING AT THIS POINT.
WE/LL MAINTAIN MENTION OF THIS SYSTEM IN THE HAZARDOUS WEATHER
OUTLOOK.
CONDITIONS WILL TREND COLDER AND DRIER FOR THANKSGIVING DAY AS
SYNOPTIC LOW DEPARTS NEWD THRU QUEBEC/CANADIAN MARITIMES. NWLY
WINDS AT 10-20 MPH WITH A FEW FLURRIES IN THE NRN GREENS INTO NERN
VT. LOWS WEDNESDAY NIGHT WILL BE IN THE UPR TEENS TO LOWER
20S...FOLLOWED BY HIGHS MAINLY IN THE 20S FOR THANKSGIVING DAY.
HIGH PRESSURE SHOULD BRING DRY AND SEASONABLY COLD CONDITIONS
FRIDAY AND SATURDAY. HIGH TEMPS GENERALLY REMAIN IN THE 20S THRU
THE END OF THE FORECAST PERIOD SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...STRONG W-NW WINDS WILL CONTINUE INTO THIS
EVENING. SNOW SHOWER ACTIVITY IS GRADUALLY DECREASING WITH DRIER
AIR MOVING IN...BUT PERIODS OF IFR AT KMPV DUE TO BLOWING SNOW.
ELSEWHERE...VFR WITH CLRG SKIES BY AND DURING THE EVENING.
KBTV/KMPV WILL SEE WNW WINDS 20G35KTS THRU 00Z MON...ELSEWHERE
WILL BE 15-18G28KTS ALL DIMINISHING AFT 04Z.
OUTLOOK 18Z MONDAY THROUGH THURSDAY...DRY AND MOSTLY CLEAR VFR WITH
HIGH PRESSURE IN PLACE MONDAY. THERE WILL BE A CHANCE FOR MVFR
CIGS/VIS IN SNOW SHOWERS MONDAY NIGHT AND TUESDAY AS WEAK UPPER
LEVEL TROUGH MOVES ACROSS THE NORTH COUNTRY. MODERATE TO HIGH PREDICTABILITY
FOR WEDNESDAY WITH INCREASING CONFIDENCE OF STORM TRACK WITHIN 50
MILES OF A KLGA-KBDL-KORH-KCON LINE. POSSIBILITY EXISTS FOR IFR
CONDITIONS WITH ACCUMULATING SNOWFALL AND MIXED WEDNESDAY BUT DETAILS
ARE UNCERTAIN. THURSDAY...MODERATE N-NW WINDS WITH ISOLD -SHSN
POSSIBLE...MAINLY VCNTY MTNS. TAF LOCATIONS SHOULD BE MAINLY VFR
FOR THURSDAY.
&&
.MARINE...
AS OF 352 AM EST SUNDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
AND WILL LIKELY REMAIN SO THROUGH TONIGHT. WINDS NORTHWEST 20 TO
30 KNOTS...TAPERING TO 15 TO 25 KNOTS TONIGHT. WAVES WILL BUILD TO
3-5 FEET IMPACTING NORTH-FACING EXPOSURES.
&&
.CLIMATE...
THE COLD TEMPERATURES SUNDAY 11/24 INTO MONDAY 11/25 MAY APPROACH
RECORD LEVELS. THE RECORDS ARE LISTED BELOW:
RECORD LOW AND RECORD LOW MAXIMUMS SUNDAY 11/24:
BURLINGTON (BTV)- 2 (1956), 19 (1938)
MONTPELIER (MPV)- -4 (1989), 20 (2000)
MASSENA (MSS)- -8 (2000), 19 (1996)
SAINT JOHNSBURY (SJBV1)- -6 (1989), 20 (1921)
RECORD LOW AND RECORD LOW MAXIMUMS MONDAY 11/25:
BURLINGTON (BTV)- -1 (1938), 14 (1938)
MONTPELIER (MPV)- 4 (1997,1993), 24 (1993,1971)
MASSENA (MSS)- 5 (2005), 23 (1993)
SAINT JOHNSBURY (SJBV1)- 0 (1956), 19 (1938)
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR VTZ003-004-
006>008-010-012-016>019.
NY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ028-031-034-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS/SLW
MARINE...LOCONTO
CLIMATE...MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
931 AM EST SUN NOV 24 2013
.SYNOPSIS...
THE NORTH COUNTRY WILL REMAIN UNDER COLD NORTHWESTERLY FLOW FOR
TODAY AND TONIGHT...AS LOW PRESSURE REMAINS TO OUR EAST AND HIGH
PRESSURE OFF TO OUR WEST. THAT AREA OF HIGH PRESSURE WILL SHIFT
EAST OVER THE REGION LATER TONIGHT...FOLLOWED BY ANOTHER LOW FOR
MONDAY AFTERNOON INTO TUESDAY. THERE IS THE POTENTIAL FOR A WINTER
STORM TO AFFECT THE REGION STARTING LATE TUESDAY NIGHT AND INTO
WEDNESDAY NIGHT. HIGH PRESSURE SLOWLY RETURNS FOR THURSDAY INTO
FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 931 AM EST SUNDAY...HAVE UPDATED THE FORECAST TO RAISE POPS
ACROSS MUCH OF NC/NE VT THROUGH THE DAY...AND TO INTRODUCE AREAS
OF BLOWING SNOW IN THESE AREAS. ALSO LOWERED HOURLY AND MAX
TEMPERATURES BY A FEW DEGREES BASED OFF CURRENT OBSERVATIONAL DATA
AND LATEST LAMP GUIDANCE NUMBERS. COLD DAY ON TAP WITH STRONG AND
GUSTY NORTHWESTERLY FLOW CONTINUING. THUS WIND ADVISORIES REMAIN
IN PLACE...ESP ACROSS THE HIGHER TERRAIN AND DOWNSLOPE LOCATIONS
ALONG THE EASTERN SLOPES OF THE DACKS/GREENS. STRONGEST GUSTS
LIKELY THIS AFTERNOON WHEN SECONDARY PRESSURE SURGE PUSHES SOUTH
INTO THE REGION. GUSTS IN ADVISORY LOCATIONS IN THE 35 TO 45 MPH
RANGE WITH LOCALLY HIGHER GUSTS...SLIGHTLY LESS ELSEWHERE. WHILE
MOISTURE CONTINUES TO SLOWLY THIN...LINGERING WRAP- AROUND
OROGRAPHICALLY ENHANCED SHSN CONTINUE ACROSS THE NRN MTNS WHERE
SOME MINOR ADDITIONAL ACCUMULATIONS WILL BE POSSIBLE TODAY. THIS
IS IN CLOSE AGREEMENT WITH LATEST 12/13Z RAP PROGS WHICH HAVE A
GOOD HANDLE ON THE CURRENT SITUATION. THUS WILL LEAN IN ITS
DIRECTION ACCORDINGLY. WITH DEEPLY MIXED PBL...FROUDE NUMBERS
QUITE HIGH SO BEST COVERAGE OF SHSN/ACCUMS FROM THE GREEN MTN
SPINE EASTWARD. TEMPERATURES REALLY GOING NOWHERE WITH SUCH STRONG
CAA IN PLACE...SO READINGS HOLDING MORE OR LESS STEADY...PERHAPS
CLIMBING A DEGREE OR TWO WILL BE ALL WE GET TODAY. WITH THE
AFORMENTIONED WINDS THE APPARENT TEMPS SHOULD RANGE IN THE -10F TO
+5F RANGE...COLDER TO NEAR -20F AT THE SUMMITS. DEFINITELY A DAY
TO WEAR THE FULL WINTER CLOTHING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 352 AM EST SUNDAY...TONIGHT WITH RIDGE APPROACHING AND WINDS
ABATING...TEMPS WILL DROP SHARPLY TO LOWEST OF THE SEASON SO FAR
WITH LOWS RANGING FROM -5 TO 10F IN DACKS TO SINGLE NUMBERS
ELSEWHERE. WIND ADVISORY REMAINS IN AFFECT THRU TNGT AS TIGHT
GRADIENT CREATING STEADY 15-30 MPH WINDS WITH GUSTS
40-50MPH...HIGHEST OVER DACKS AND E VT. BY 00Z MONDAY...GRADIENT
WILL SLACKEN AND TAPER OFF BY MIDNGT WITH ARRIVAL OF SFC RIDGE.
WIND CHILL ISSUES POSSIBLE IN RANGE OF 0F TO -10F.
COLD CHILLY MORNING ON MONDAY W/ RIDGE CRESTING OVER THE AREA AND
SLIDING S AND E DURING THE DAY. THIS WILL ALLOW WAA ON SSW FLOW TO
SETUP OVER THE AREA...AND PROVIDE A NICE REBOUND IN TEMPS FROM THE
COLD WEEKEND. WAA WILL BRING HIGHS MONDAY INTO THE 20S FOR ALL
SITES. INCR CLDS THOUGH OVER N NY AS NORTHERN STREAM SYSTEM COMES
OUT OF THE GREAT LKS REGION AND INTO QUEBEC MON AFTNOON/TUESDAY
MORNING. BLOCKING RIDGE TO OUR SOUTH WILL PUT BEST POP FOCUS OVER
N NY TAPERING DOWN TO SE VT. ADDITIONAL LIGHT SNOWFALL WILL OCCUR
BRINGING AROUND AN INCH OF NEW SNOW TAPERING OFF TO A POTENTIAL
DUSTING IN SOUTHERN ZONES. CLD COVER KEEPS TEMPS FROM DROPPING TOO
MUCH ALONG WITH GRADIENT STAYING SW. LOOKING FOR LOWS IN THE TEENS
TO L20S. GOING INTO TUESDAY SW GRADIENT STAYS INTACT FOR THE DAY
AS NORTHERN SYSTEM...THAT COULD BRING STORM NEAR
THANKSGIVING...SWINGS THRU THE GREAT LKS. CLDS/MOISTURE FEED WILL
ALLOW FOR SL CHANCE OF -SW WITH FOCUS OVER SOUTHERN ZONES. OVERALL
INCH OR LESS EXPECTED...WITH HIGHS IN THE 30S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 640 AM EST SUNDAY...STILL CONSIDERABLE MODEL DIFFERENCES
CONCERNING MOISTURE-LADEN SYNOPTIC LOW EXPECTED TO AFFECT THE
NORTH COUNTRY TUESDAY NIGHT INTO WEDNESDAY...WHICH UNFORTUNATELY
COINCIDES WITH ONE OF THE BUSIEST TRAVEL DAYS OF THE YEAR. THE 00Z
NWP DIFFERENCES CONTINUE TO SURROUND INTERACTION BETWEEN VIGOROUS
BUT DISTINCT NRN AND SRN STREAM SHORTWAVE TROUGHS AS SYSTEMS CROSS
THE OHIO VALLEY AND SERN STATES...RESPECTIVELY. THE DEEPER AND
MORE PHASED SOLN OFFERED BY THE 00Z ECMWF TAKES THE LOW INLAND UP
THE EAST COAST AND ULTIMATELY TRACKS A 986MB LOW ACROSS VT BETWEEN
18Z WED AND 00Z THU. THIS IS A WARMER SOLN WITH 850MB TEMPS
REACHING +8C ACROSS VT AT 18Z WEDNESDAY. ANY SNOW AT THE ONSET TUESDAY
NIGHT WOULD SWITCH OVER TO MAINLY RAIN ACROSS THE REGION.
MEANWHILE...THE 00Z GFS CONTINUES THAT MODEL/S TENDENCY TO KEEP A
FASTER MOVING SYSTEM OFFSHORE BETWEEN THE 40N 70W BENCHMARK AND
CAPE COD WITH A 994MB LOW MOVING THROUGH AT 18Z WEDNESDAY. THIS IS
A MUCH COLDER SOLN...WITH POTENTIAL ACCUMULATING SNOW ACROSS VT
AND LESS PRECIPITATION IMPACT FOR NRN NY. HAVE INCREASED POPS TO
70-80 PERCENT LATE TUESDAY THROUGH WEDNESDAY ASSOCIATED WITH THIS
SYSTEM WITH QPF ON THE ORDER OF 1"...BUT IT REMAINS TOO SOON TO
DETERMINE P-TYPE DETAILS GIVEN UNCERTAIN EVOLUTION/PHASING OF NRN
AND SRN STREAMS. THOSE WITH TRAVEL PLANS WEDNESDAY SHOULD CONSIDER
PROSPECT FOR WINTER TRAVEL CONDITIONS ACROSS THE NORTH
COUNTRY...BUT THAT IS BY NO MEANS A SURE THING AT THIS POINT.
WE/LL MAINTAIN MENTION OF THIS SYSTEM IN THE HAZARDOUS WEATHER
OUTLOOK.
CONDITIONS WILL TREND COLDER AND DRIER FOR THANKSGIVING DAY AS
SYNOPTIC LOW DEPARTS NEWD THRU QUEBEC/CANADIAN MARITIMES. NWLY
WINDS AT 10-20 MPH WITH A FEW FLURRIES IN THE NRN GREENS INTO NERN
VT. LOWS WEDNESDAY NIGHT WILL BE IN THE UPR TEENS TO LOWER
20S...FOLLOWED BY HIGHS MAINLY IN THE 20S FOR THANKSGIVING DAY.
HIGH PRESSURE SHOULD BRING DRY AND SEASONABLY COLD CONDITIONS
FRIDAY AND SATURDAY. HIGH TEMPS GENERALLY REMAIN IN THE 20S THRU
THE END OF THE FORECAST PERIOD SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...ARCTIC FRONT HAS PUSHED EAST OF THE REGION AND
STRONG W-NW WINDS WILL CONTINUE IN ITS WAKE AT ALL TAF SITES TODAY
AND INTO THIS EVENING. SNOW SHOWER ACTIVITY IS GRADUALLY
DECREASING WITH DRIER AIR MOVING IN...BUT PERIODS OF IFR SNOW MAY
CONTINUE AT MPV/SLK THRU 16Z. AT BTV...NW WINDS 15-20KTS WITH
GUSTS TO 28KTS ARE EXPECTED THROUGH 15Z...INCREASING TO 20G34KT
DURING THE AFTN HOURS. CEILINGS MAINLY MVFR AREAWIDE...IMPROVING
TO VFR LATE TODAY WITH CLEARING AND DIMINISHING WINDS TONIGHT.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...DRY AND MOSTLY CLEAR VFR
WITH HIGH PRESSURE IN PLACE MONDAY. THERE WILL BE A CHANCE FOR
MVFR CIGS/VIS IN SNOW SHOWERS MONDAY NIGHT AND TUESDAY AS WEAK
UPPER LEVEL TROUGH MOVES ACROSS THE NORTH COUNTRY. LOW
PREDICTABILITY FOR WEDNESDAY WITH UNCERTAIN TRACK OF COASTAL LOW
PASSING SE-E OF CAPE COD. POSSIBILITY EXISTS FOR IFR CONDITIONS
AND ACCUMULATING SNOWFALL WEDNESDAY BUT DETAILS ARE UNCERTAIN.
THURSDAY...MODERATE N-NW WINDS WITH ISOLD -SHSN POSSIBLE...MAINLY
VCNTY MTNS. TAF LOCATIONS SHOULD BE MAINLY VFR FOR THURSDAY.
&&
.MARINE...
AS OF 352 AM EST SUNDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
AND WILL LIKELY REMAIN SO THROUGH TONIGHT. WINDS NORTHWEST 20 TO
30 KNOTS...TAPERING TO 15 TO 25 KNOTS TONIGHT. WAVES WILL BUILD TO
3-5 FEET IMPACTING NORTH-FACING EXPOSURES.
&&
.CLIMATE...
THE COLD TEMPERATURES SUNDAY 11/24 INTO MONDAY 11/25 MAY APPROACH
RECORD LEVELS. THE RECORDS ARE LISTED BELOW:
RECORD LOW AND RECORD LOW MAXIMUMS SUNDAY 11/24:
BURLINGTON (BTV)- 2 (1956), 19 (1938)
MONTPELIER (MPV)- -4 (1989), 20 (2000)
MASSENA (MSS)- -8 (2000), 19 (1996)
SAINT JOHNSBURY (SJBV1)- -6 (1989), 20 (1921)
RECORD LOW AND RECORD LOW MAXIMUMS MONDAY 11/25:
BURLINGTON (BTV)- -1 (1938), 14 (1938)
MONTPELIER (MPV)- 4 (1997,1993), 24 (1993,1971)
MASSENA (MSS)- 5 (2005), 23 (1993)
SAINT JOHNSBURY (SJBV1)- 0 (1956), 19 (1938)
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR VTZ003-004-
006>008-010-012-016>019.
NY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR NYZ028-031-034-
035.
&&
$$
SYNOPSIS...JN
NEAR TERM...JMG
SHORT TERM...JN
LONG TERM...BANACOS
AVIATION...BANACOS
MARINE...LOCONTO
CLIMATE...MUCCILLI
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1055 PM EST MON NOV 25 2013
.SYNOPSIS... A LOW PRESSURE SYSTEM WILL DEVELOP IN THE GULF OF
MEXICO TONIGHT...THEN INTENSIFY AND TRACK NORTHEAST ALONG THE
CAROLINA AND MID ATLANTIC COAST LATE TUESDAY THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM MONDAY...
TONIGHT: SURFACE HIGH PRESSURE IS CURRENTLY SHIFTING OFF THE NORTH
CAROLINA COAST. HOWEVER... THE LOW LEVELS REMAIN QUITE DRY ACROSS
THE AREA IN THE WAKE OF THE DEPARTING ARCTIC HIGH PRESSURE. ALOFT...
MID AND UPPER LEVEL MOISTURE IS BEGINNING TO STREAM INTO THE AREA IN
ASSOCIATION WITH A STRENGTHENING LOW PRESSURE SYSTEM OVER THE GULF
COAST STATES. THIS SYSTEM WILL QUICKLY APPROACH THE AREA
OVERNIGHT... SPREADING OVERCAST SKIES AND EVENTUALLY PRECIP INTO THE
WEST/NORTHWEST PIEDMONT AFTER MIDNIGHT... THEN SPREADING EASTWARD
ACROSS THE REST OF THE AREA AFTER DAYBREAK. IN FACT WE ARE ALREADY
SEEING SOME RETURNS ON RADAR THIS EVENING. CANT RULE OUT A FEW
SPRINKLES OR SLEET PELLETS LATE THIS EVENING WITH THE BEST
RETURNS... BUT THE AMOUNT OF DRY AIR IN THE LOW LEVEL (AS EVIDENT BY
THE 00Z KGSO SOUNDING ALONG WITH RAP MODELS SOUNDING FOR THE WESTERN
PIEDMONT) SUGGEST ANY PRECIP WILL HAVE A HARD TIME REACHING THE
GROUND OVER THE COURSE OF THE REST OF THE EVENING HOURS. HOWEVER...
WITH LOW LEVEL SOUTHERLY FLOW (925-850 MB) RAMPING UP BELOW THE COLD
DRY SURFACE ALONG WITH INCREASING UPPER DIVERGENCE EXPECT WE WILL
SEE A MOISTENING OF THE LOW LEVELS AND PRECIP BEGINNING TO FALL
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT AFTER MIDNIGHT TONIGHT.
TIMING WISE... THE HRRR IS SHOWING PRECIP MOVING INTO OUR FAR
NORTHWEST PIEDMONT FIRST AROUND 07-09Z... THE MOVING INTO THE REST
OF OUR NORTHWEST PIEDMONT AND WESTERN PIEDMONT COUNTIES BY 12Z...
WITH THE MEASURABLE PRECIP EXPECTED TO BE NEAR RALEIGH BY AROUND
DAYBREAK.
AS THE PRECIP MOVES INTO THE AREA EXPECT WE WILL LIKELY SEE A BRIEF
PERIOD OF SLEET THANKS TO THE DRY LOW LEVEL AIRMASS THE INITIAL
PRECIP WILL FALL THROUGH. THEN... WE WILL NEED TO TAKE A LOOK AT OUR
SURFACE WET-BULB TEMPS AND THE POTENTIAL FOR FREEZING RAIN... AS THE
WARM NOES IS FORECAST TO BE IN EXCESS OF 5 DEGREES C. AND SHOULD
KEEP ANY PRECIP IN THE FORM OF RAIN/FREEZING RAIN AFTER THE INITIAL
LOW LEVEL AIRMASS IS SATURATED. CURRENT SURFACE TEMPS HAVE LEVELED
OFF/INCREASED A BIT WITH THE CLOUD COVER MOVING INTO THE AREA... IN
THE MID TO UPPER 30S. HOWEVER... SURFACE DEWPOINTS ACROSS THE AREA
IN THE SINGLE DIGITS/TEENS WILL ALLOW FOR THE POTENTIAL TO
EVAPORATIVELY COOL OUR TEMPS TO BELOW FREEZING ACROSS PORTIONS OF
OUR NORTHWEST/NORTHERN PIEDMONT EARLY TUESDAY MORNING THROUGH AROUND
15Z OR SO. THE BELOW FREEZING SURFACE WET-BULB TEMPS WHEN SUFFICIENT
PRECIP MOVES INTO THE AREA IN THE 09-12Z TIME FRAME WILL LOWER TEMPS
TO FREEZING OR JUST BELOW FREEZING ACROSS THE COUNTIES LISTED IN OUR
WINTER WEATHER ADVISORY. WILL NOT EXPAND THE ADVISORY AT THIS
TIME... AS CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME. IF ANY
COUNTIES WOULD NEED TO BE ADDED IT WOULD BE GRANVILLE AND VANCE...
WITH PERHAPS NORTHERN PORTIONS OF DURHAM COUNTY AND NORTHWESTERN
PORTIONS OF CHATHAM COUNTY POSSIBLY CAUSING THE INCLUSION OF THESE
COUNTIES. THE REASON FOR NOT ADDING THESE COUNTIES NOW IS WE WILL
NEED HEAVY ENOUGH PRECIP TO BE ABLE TO EVAPORATIVELY COOL DOWN TO
THE WET-BULB TEMPS. GIVEN THESE AREAS ARE ON THE FRINGE OF
SUFFICIENT PRECIP AND SUB-FREEZING WET-BULB TEMPS WILL HOLD OFF FOR
NOW. EXPECT ANY FREEZING RAIN THREAT SHOULD END BY MID MORNING AS
THE SUPPLY OF COLD DRY AIR AT THE SURFACE WILL BE LIMITED THANKS TO
THE SURFACE HIGH PRESSURE CENTER MOVING OFFSHORE... CREATING AN IN-
SITU DAMMING EVENT. THUS... MAKING THE FREEZING RAIN EVENT A SELF-
LIMITING PROCESS THANKS TO THE LATENT HEATING FROM PHASE CHANGE. ANY
ICE ACCRUAL IS EXPECTED TO BE GENERALLY LIMITED TO A TENTH OF AN
INCH OR LESS... WITH THE HIGHEST AMOUNTS EXPECTED IN NORTHWEST
FORSYTH COUNTY.
LOW TEMPS FOR THIS PERIOD HAVE ALREADY OCCURRED ACROSS MOST OF THE
COASTAL PLAIN COUNTIES... IN THE MID TO UPPER 20S. TEMPS ACROSS
THESE LOCATIONS HAVE RISEN AS CLOUD COVER HAS MOVED INTO THE AREA
THIS EVENING... NOW IN THE MID 30S IN GENERAL. LOWS ACROSS THE
WESTERN AND NORTHERN PIEDMONT SHOULD OCCUR AS THE PRECIP MOVES INTO
THE AREA... WITH LOCATIONS IN THE MIDDLE OF THE CWA GENERALLY
REMAINING NEAR STEADY TONIGHT (MID TO UPPER 30S).
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
TUESDAY... PRECIP WILL BECOME WIDESPREAD ACROSS CENTRAL NC DURING
THE FIRST HALF OF THE MORNING. EXPECT WINTRY PRECIP IN THE NW
PIEDMONT TO TRANSITION TO MAINLY A COLD RAIN IN THE LATE MORNING.
POTENTIAL FOR THE ADVISORY TO BE CANCELED PRIOR TO NOON EXPIRATION
IF WARMING OCCURS SOONER OR IS STRONGER THAN EXPECTED. INCREASING
DIVERGENCE ALOFT COUPLED WITH INCREASING CONVERGENCE AS A SFC WARM
FRONT MIGRATES INLAND FROM THE COAST WILL INCREASE THE LIFT THROUGH
THE ENTIRE COLUMN. CONVERGENCE LONG THIS BOUNDARY WILL LEAD TO
ENHANCE PRECIP...LEADING TO LOCALLY HEAVY RAINFALL. BEST SHOT OF
AXIS OF HEAVY RAIN APPEARS TO EXIST IN VICINITY OF THE HIGHWAY 1
CORRIDOR. EXPECT STORM TOTALS AMOUNTS 1-2 INCHES WITH LOCALIZED
AMOUNTS AROUND 2.5 INCHES.
TEMPERATURE-WISE...COLD RAIN WILL ENTRENCH THE TRIAD IN AN IN-SITU
DAMMING EVENT AS TEMPS WILL STRUGGLE THROUGH THE 30S. THE INLAND
ADVANCING WARM FRONT WILL LIKELY CREATE A WIDE TEMP VARIANCE BETWEEN
THE TRIANGLE AND THE COASTAL PLAIN. EXPECT TEMPS TO VARY AS MUCH AS
15-20 DEGREES...RANGING THE 40S-50 IN THE TRIANGLE TO THE LOWER 60S
EAST OF I-95. LATEST MODEL GUIDANCE HAS COME MORE INLAND WITH HE SFC
LOW. IF THIS VERIFIES...POTENTIAL FOR A TEMPERATURE BUST IN VICINITY
OF THE TRIANGLE WHERE A TEMPERATURE SWING OF 10-12 DEGREES MAY
OCCUR. BASED ON LATEST GUIDANCE...MAY ADJUST TEMPS UP 4-7 DEGREES
FROM PREVIOUS FORECAST.
TUESDAY NIGHT... FORECAST STILL CHALLENGING THIS PERIOD...DEPENDENT
UPON EXTENT OF AVAILABLE SFC BASED INSTABILITY AND EVENTUAL TRACK OF
SFC LOW. WIDESPREAD RAIN OR SHOWERS WILL CONTINUE. INCREASING LOW
LEVEL JET (AS HIGH AS 60-65KTS OFF THE NAM)WIL PROVIDE INCREDIBLE
SHEAR AND STORM RELATIVE HELICITY. FORECAST MODEL SOUNDINGS MAINTAIN
A CONDITIONALLY STABLE AIR MASS WITH BEST INSTABILITY ALOFT.
EXCEPTION IS THE NAM WHICH SUGGEST THAT SFC BASED INSTABILITY MAY
OCCUR OVER OUR FAR SE COUNTIES FOR A FEW HOURS LATE TUESDAY NIGHT
(10 PM - 4 AM). BASED ON THE MODEL TREND OF A SFC LOW TRACK A LITTLE
FARTHER INLAND...SOME POTENTIAL FOR A SFC BASED THUNDERSTORM TO
OCCUR WITH A SMALL THREAT FOR A SEVERE STORM WITH DAMAGING WIND
GUSTS OR A BRIEF TORNADO THE MAIN SEVERE WEATHER THREAT.
TEMPS TUESDAY NIGHT WILL HOLD STEADY OR SLOWLY RISE ACROSS MOST
LOCATION EXCLUDING THE NW PIEDMONT WHERE TEMPS WILL HOLD STEADY.
TEMPS IN THE SANDHILLS AND COASTAL PLAIN MAY RISE OR HOLD STEADY IN
THE LOW-MID 60S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 325 PM MONDAY...
FOR WED/WED NIGHT: MODELS ARE IN GOOD AGREEMENT ON PLACING THE
PRIMARY SURFACE LOW NEAR NYC WED MORNING AND THE SECONDARY WEAKER
LOW OVER THE VA TIDEWATER... WHICH BOTH CONSOLIDATE INTO A SINGLE
LOW OVER MAINE BY DAY`S END. THE SOUTHERN STREAM PORTION OF THE
STORM SYSTEM WILL BE WEAKENING AS IT LIFT NORTHEASTWARD THROUGH NC
FROM MID MORNING THROUGH EARLY AFTERNOON... BUT IT WILL STILL BE
QUITE POTENT INDUCING STRONG FORCING FOR ASCENT AS IT MAINTAINS A
NEGATIVE TILT. THE MID-UPPER LEVELS ACCORDING TO FORECAST SOUNDINGS
WILL DRY OUT QUITE A BIT IN THE MORNING AS A DRY SLOT PUNCHES IN
FROM THE SOUTH... SUGGESTING A TRANSITION TO PATCHY DRIZZLE (OR
PERHAPS A LITTLE FREEZING DRIZZLE IN THE FAR NW CWA WHERE SURFACE
WET BULB TEMPS WILL BE DROPPING TO AROUND 32F) AS THE COLDER AIR
ARRIVES POST-FRONT... WITH THE LOWEST 4 KM OR SO STAYING SATURATED.
A SLUG OF DPVA ASSOCIATED WITH THE NORTHERN STREAM PORTION OF THE
MID LEVEL LONGWAVE TROUGH SWINGS THROUGH NW NC WED AFTERNOON
ATTENDING A DEFORMATION ZONE ALOFT... HOWEVER THESE TOO SHOULD BE
WEAKENING AND DON`T APPEAR TO PROVIDE ENOUGH DEEP LAYER LIFT TO RE-
SATURATE THE AIR ABOVE -10C. AS SUCH... BELIEVE THAT A FEW WET
FLAKES WILL BE POSSIBLE ACROSS THE NW AND FAR NRN PIEDMONT WED
AFTERNOON AS THE COLUMN COOLS... BUT IT SHOULD BE INCONSEQUENTIAL
GIVEN THE BRIEF WINDOW OF OPPORTUNITY AND LIMITED MOISTURE ALOFT.
PASSAGE OF A WEAK POST-FRONTAL SURFACE TROUGH WED AFTERNOON WILL
SWING WINDS AROUND TO A UNIFORMLY NW DIRECTION... YIELDING CLEARING
SKIES BY EARLY EVENING AS DOWNSLOPE FLOW AND DRY AIR ADVECTION TAKES
OVER. WITH A TIGHTENING MSLP GRADIENT DUE TO THE STRENGTHENING
DEPARTING SURFACE LOW... THESE BRISK NW WINDS DURING THE DAY ARE
EXPECTED TO TOP OUT AT 15-20 MPH SUSTAINED WITH GUSTS OVER 30 MPH
POSSIBLE AS STRONG 925 MB WINDS NEAR 35 KT MIX DOWN TO THE SURFACE.
WED HIGHS ARE APT TO BE VERY CLOSE TO THE MORNING LOWS... WITH
PLUNGING THICKNESSES THROUGH THE DAY WITH STEADY COLD AIR ADVECTION
CAUSING TEMPS TO FALL SLOWLY THROUGH THE DAY. EARLY DAY HIGHS FROM
THE UPPER 30S NW TO LOWER 60S IN THE EASTERN COASTAL PLAIN...
FALLING TO THE MID 30S NW TO MID 40S EAST BY LATE AFTERNOON. DEW
POINTS WILL FALL INTO THE TEENS TO LOWER 20S OVERNIGHT WITH CLEARING
SKIES... BUT THE CONTINUED LOW LEVEL MIXING WILL KEEP TEMPS FROM
FALLING TOO LOW... BUT STILL CHILLY WITH LOWS 22-28. LATE DAY WIND
CHILLS ARE EXPECTED TO FALL INTO THE 20S OVER THE PIEDMONT... AND
INTO THE TEENS TO AROUND 20 AREAWIDE WED NIGHT WITH DIMINISHING
WINDS.
FOR THU/THU NIGHT: THE CORE OF THE MID LEVEL TROUGH WILL BE WELL TO
OUR NE BY THU MORNING... ALTHOUGH BROAD FLAT TROUGHING WILL PERSIST
OVER THE EASTERN CONUS AS A VORTEX SPINS OFF CA WITH WEAK LONGWAVE
RIDGING IN BETWEEN. SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA
FROM THE WSW AND DRIFT OVER THE SRN/CENTRAL APPALACHIANS AND MID-
ATLANTIC THROUGH THU NIGHT. EXPECT A DRY AND SUBSIDING COLUMN WITH
JUST A FEW HIGH CLOUDS AS ONE LAST WEAK PERTURBATION SWEEPS OVER THE
REGION. MAX TEMPS SHOULD BE COMPARABLE TO YESTERDAY GIVEN A SIMILAR
AIR MASS WITH SIMILAR (PERHAPS A BIT HIGHER) PREDICTED THICKNESSES.
HIGHS 38-45. MOSTLY CLEAR AND CONTINUED COLD THU NIGHT. LOWS 22-27
LOOK GOOD.
FOR FRI THROUGH MON: THE SRN STREAM PORTION OF THE SURFACE HIGH WILL
MERGE WITH THE POLAR HIGH TO BE CENTERED OVER MAINE/SW QUEBEC AND
NOSE TO THE SSW THROUGH CENTRAL NC FRI THROUGH SAT... AS THE MID
LEVEL FLOW OVER THE CENTRAL/ERN CONUS FLATTENS. AN INVERTED TROUGH
IS EXPECTED TO FORM ALONG THE SOUTHEAST COAST OVER THE WEEKEND...
AND THE ENHANCED ONSHORE-DIRECTED LOW LEVEL FLOW SHOULD PULL
INCREASING LOW LEVEL ATLANTIC MOISTURE INTO NC... RESULTING IN
INCREASING CLOUDS AS WE HEAD THROUGH SUNDAY. THE MID LEVEL LOW OFF
CA LATE IN THE WEEK OPENS UP AND WEAKENS THEN HEADS EASTWARD... AND
AS THIS BROAD TROUGH APPROACHES NC FROM THE WEST LATE SUN THROUGH
MON... EXPECT A TREND TO MOSTLY CLOUDY SKIES AND A CHANCE OF RAIN AS
THE OLD FRONT HEADS NORTHWARD TOWARD NC AS A WARM FRONT. EXPECT A
GRADUAL RECOVERY IN TEMPS THROUGH THIS PERIOD... STAYING BELOW
NORMAL HOWEVER. HIGHS IN THE 40S TO NEAR 50 FRI/SAT... CLIMBING TO
THE 50S TO NEAR 60 FOR SUN/MON. -GIH
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 630 PM MONDAY...
POOR AVIATION CONDITIONS TO DEVELOP LATE TONIGHT AND PERSIST INTO
WEDNESDAY.
HIGH CLOUDS ARE STARTING TO OVERSPREAD THE AREA FROM THE
SOUTHWEST...AND THERE ARE SOME INDICATIONS THAT SOME LOW-LEVEL
MOISTURE AROUND 3K FT IS ALREADY REACHING AREAS SOUTH AND WEST OF
CHARLOTTE. THIS WOULD BE A COUPLE HOUR QUICKER THAN MODEL
FORECASTS. THIS TRENDING IN LOW-LEVEL MOISTENING WILL CONTINUE
OVERNIGHT WHILE A LOW PRESSURE SYSTEM BEGINS TO TAKE SHAPE OVER THE
NORTHERN GULF OF MEXICO. PRECIP SHOULD BEGIN SPREADING ACROSS
WESTERN NC AFTER MIDNIGHT...AND A PERIOD OF FREEZING RAIN WILL BE
POSSIBLE AT KGSO AND KINT...MAINLY BETWEEN 09Z AND 14Z...BEFORE
CHANGING OVER TO ALL RAIN BY MID-MORNING. ELSEWHERE...ALL RAIN IS
EXPECTED. CEILINGS WILL ULTIMATELY REACH IFR EVERYWHERE...AND
LIKELY LIFR AT KGSO AND KINT AS HEAVIER RAIN MOVES ACROSS THE AREA
BY TUESDAY AFTERNOON. LOW CEILINGS WILL PERSIST THROUGH TUESDAY
NIGHT FOR MOST AREAS...THOUGH CONFIDENCE IS LOWER AT KFAY AND
KRWI...AS A WARM FRONT IS EXPECTED TO MOVED INLAND...WHICH MAY
SCATTER SOME OF THE LOW CLOUDS AND INCREASE THE CHANCE OF
THUNDERSTORMS OVERNIGHT. LOW-LEVEL WINDSHEAR WILL BE A CONCERN FOR
MOST OF THE DAY ON TUESDAY AS WELL.
OUTLOOK... MVFR AND IFR CEILINGS WILL LINGER INTO WEDNESDAY BEFORE
IMPROVING WEDNESDAY NIGHT AND THURSDAY AS A COLD FRONT SWINGS
ACROSS THE AREA ON THE HEELS OF A DEPARTING LOW PRESSURE SYSTEM. A
DRIER AND MORE STABLE AIR MASS WILL PERSIST ACROSS THE REGION INTO
THE WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...WSS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
958 PM CST MON NOV 25 2013
.UPDATE...
ISSUED AT 958 PM CST MON NOV 25 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 707 PM CST MON NOV 25 2013
LOW CLOUDS WILL CONTINUE PRIMARILY ALONG AND EAST OF THE MISSOURI
RIVER TONIGHT. FURTHERMORE...BOUNDARY LAYER WINDS ARE
FORECAST TO REMAIN AROUND 30 KNOTS EAST OF HIGHWAY 83 THROUGH 12Z
TUESDAY. GIVEN THE COMBINATION OF LOW CLOUDS AND TURBULENT
BOUNDARY LAYER FLOW...ADJUSTED OVERNIGHT LOWS UP BY TWO
CATEGORIES...MAINLY EAST OF HIGHWAY 83. HIGH PRESSURE NOSING INTO
WESTERN NORTH DAKOTA WILL LIKELY CLEAR OUT THE CLOUDS WEST AFTER
MIDNIGHT AND ALLOW TEMPERATURES TO RADIATE INTO THE SINGLE DIGITS
WEST OF HIGHWAY 85 BY TUESDAY MORNING.
THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
A STRONGER SURGE OF COLD AIR ADVECTION WILL PUSH SOUTH INTO NORTH
DAKOTA OVERNIGHT. AFTERNOON OBS AND REFLECTIVITY NEAR ROLLA...AND
LIGHT QPF SCATTERED ALONG THE EASTERN FRINGES OF THE FORECAST AREA
IN SOME SHORT RANGE MODELS...HAVE PROMPTED INCLUSION OF FLURRIES
FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY TONIGHT.
A FEW AFTERNOON OBS AT MINOT AND TIOGA...SUGGESTIVE OF FREEZING
DRIZZLE/UNKNOWN PRECIP...ARE ACTUALLY THE RESULT OF EXISTING SNOW
BEING BLOWN NEAR THE WEATHER SENSOR.
HAVE INCREASED OVERNIGHT CLOUD COVER BASED ON AFTERNOON TRENDS AND
ROBUST LOW LEVEL RH EVIDENT ON THE RAP MODEL. LOWS SHOULD BE IN THE
SINGLE DIGITS TO AROUND 10 DEGREES SOUTH. TUESDAY WILL BE THE
COLDEST DAY OF THE COMING WEEK...WITH HIGHS IN THE TEENS TO LOWER
20S SOUTHWEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
LATEST EXTENDED SUITE CONTINUES TO SHOW AN ACTIVE PERIOD IN TERMS
OF SUCCESSIVE DRY FRONTAL SYSTEMS SLIDING THROUGH. THE NEXT
POTENTIALLY SIGNIFICANT SYSTEM MAY OCCUR MONDAY AND BEYOND.
A PROGRESSIVE PATTERN BEGINS THE LONG TERM WITH A WAVERING
BAROCLINIC ZONE SHIFTING FROM WEST TO EAST TUESDAY NIGHT AS WARM AIR
ADVECTION COMMENCES. A WEAK COLD FRONT FOLLOWS FOR WEDNESDAY/
WEDNESDAY NIGHT WITH A RETURN TO COLD AIR ADVECTION INTO EARLY
THURSDAY. NEUTRAL ADVECTION TO WEAK WARM AIR ADVECTION RESUMES
FRIDAY INTO SATURDAY. THE ONLY SUFFICIENT LIFT FOR MEASURABLE
PRECIPITATION DURING THIS TIME WOULD BE CONFINED TO THE TURTLE
MOUNTAINS WEDNESDAY AND FRIDAY NIGHT. HAVE COLLABORATED WITH OUR
EASTERN OFFICE AND INCORPORATED A SLIGHT CHC OF SNOW IN THE FAR
NORTHEAST. ANY SNOW ACCUMULATION WOULD BE MINIMAL AT BEST.
THE NEXT SYSTEM TO AFFECT WESTERN AND CENTRAL NORTH DAKOTA SHOWS
SIGNS OF LIGHT PRECIPITATION BREAKING OUT VIA WARM AIR ADVECTION
PROCESSES SUNDAY AFTERNOON INTO SUNDAY NIGHT. HOWEVER IT APPEARS
THE BULK OF PRECIPITATION WOULD BE IN THE FORM OF SNOW MONDAY INTO
MONDAY NIGHT. A DRY SLOT MAY FOLLOW FOR TUESDAY. STILL A LOT OF
UNCERTAINTY THIS FAR OUT AND WILL CONTINUE TO MONITOR FUTURE
MODELS RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 707 PM CST MON NOV 25 2013
MVFR CIGS WILL CONTINUE GENERALLY ALONG AND EAST OF A LINE FROM
KISN-KBIS TONIGHT. CONDITIONS WILL GRADUALLY IMPROVE TO VFR FROM
WEST TO EAST TUESDAY MORNING. VFR CONDITIONS ARE FORECAST OVER
WESTERN AND CENTRAL NORTH DAKOTA BY TUESDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
708 PM CST MON NOV 25 2013
.UPDATE...
ISSUED AT 707 PM CST MON NOV 25 2013
LOW CLOUDS WILL CONTINUE PRIMARILY ALONG AND EAST OF THE MISSOURI
RIVER TONIGHT. FURTHERMORE...BOUNDARY LAYER WINDS ARE
FORECAST TO REMAIN AROUND 30 KNOTS EAST OF HIGHWAY 83 THROUGH 12Z
TUESDAY. GIVEN THE COMBINATION OF LOW CLOUDS AND TURBULENT
BOUNDARY LAYER FLOW...ADJUSTED OVERNIGHT LOWS UP BY TWO
CATEGORIES...MAINLY EAST OF HIGHWAY 83. HIGH PRESSURE NOSING INTO
WESTERN NORTH DAKOTA WILL LIKELY CLEAR OUT THE CLOUDS WEST AFTER
MIDNIGHT AND ALLOW TEMPERATURES TO RADIATE INTO THE SINGLE DIGITS
WEST OF HIGHWAY 85 BY TUESDAY MORNING.
THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
A STRONGER SURGE OF COLD AIR ADVECTION WILL PUSH SOUTH INTO NORTH
DAKOTA OVERNIGHT. AFTERNOON OBS AND REFLECTIVITY NEAR ROLLA...AND
LIGHT QPF SCATTERED ALONG THE EASTERN FRINGES OF THE FORECAST AREA
IN SOME SHORT RANGE MODELS...HAVE PROMPTED INCLUSION OF FLURRIES
FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY TONIGHT.
A FEW AFTERNOON OBS AT MINOT AND TIOGA...SUGGESTIVE OF FREEZING
DRIZZLE/UNKNOWN PRECIP...ARE ACTUALLY THE RESULT OF EXISTING SNOW
BEING BLOWN NEAR THE WEATHER SENSOR.
HAVE INCREASED OVERNIGHT CLOUD COVER BASED ON AFTERNOON TRENDS AND
ROBUST LOW LEVEL RH EVIDENT ON THE RAP MODEL. LOWS SHOULD BE IN THE
SINGLE DIGITS TO AROUND 10 DEGREES SOUTH. TUESDAY WILL BE THE
COLDEST DAY OF THE COMING WEEK...WITH HIGHS IN THE TEENS TO LOWER
20S SOUTHWEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
LATEST EXTENDED SUITE CONTINUES TO SHOW AN ACTIVE PERIOD IN TERMS
OF SUCCESSIVE DRY FRONTAL SYSTEMS SLIDING THROUGH. THE NEXT
POTENTIALLY SIGNIFICANT SYSTEM MAY OCCUR MONDAY AND BEYOND.
A PROGRESSIVE PATTERN BEGINS THE LONG TERM WITH A WAVERING
BAROCLINIC ZONE SHIFTING FROM WEST TO EAST TUESDAY NIGHT AS WARM AIR
ADVECTION COMMENCES. A WEAK COLD FRONT FOLLOWS FOR WEDNESDAY/
WEDNESDAY NIGHT WITH A RETURN TO COLD AIR ADVECTION INTO EARLY
THURSDAY. NEUTRAL ADVECTION TO WEAK WARM AIR ADVECTION RESUMES
FRIDAY INTO SATURDAY. THE ONLY SUFFICIENT LIFT FOR MEASURABLE
PRECIPITATION DURING THIS TIME WOULD BE CONFINED TO THE TURTLE
MOUNTAINS WEDNESDAY AND FRIDAY NIGHT. HAVE COLLABORATED WITH OUR
EASTERN OFFICE AND INCORPORATED A SLIGHT CHC OF SNOW IN THE FAR
NORTHEAST. ANY SNOW ACCUMULATION WOULD BE MINIMAL AT BEST.
THE NEXT SYSTEM TO AFFECT WESTERN AND CENTRAL NORTH DAKOTA SHOWS
SIGNS OF LIGHT PRECIPITATION BREAKING OUT VIA WARM AIR ADVECTION
PROCESSES SUNDAY AFTERNOON INTO SUNDAY NIGHT. HOWEVER IT APPEARS
THE BULK OF PRECIPITATION WOULD BE IN THE FORM OF SNOW MONDAY INTO
MONDAY NIGHT. A DRY SLOT MAY FOLLOW FOR TUESDAY. STILL A LOT OF
UNCERTAINTY THIS FAR OUT AND WILL CONTINUE TO MONITOR FUTURE
MODELS RUNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 707 PM CST MON NOV 25 2013
MVFR CIGS WILL CONTINUE GENERALLY ALONG AND EAST OF A LINE FROM
KISN-KBIS TONIGHT. CONDITIONS WILL GRADUALLY IMPROVE TO VFR FROM
WEST TO EAST TUESDAY MORNING. VFR CONDITIONS ARE FORECAST OVER
WESTERN AND CENTRAL NORTH DAKOTA BY TUESDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...TM
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
642 AM CST SUN NOV 24 2013
.UPDATE...
ISSUED AT 642 AM CST SUN NOV 24 2013
NO MAJOR CHANGES THIS MORNING. THE RAP AND HRRR CONTINUE TO TRY
AND BRING SOME PRECIP IN FROM THE NORTHWEST BY THIS AFTERNOON.
HOWEVER...ACTUAL SOUNDINGS AT KBIS AND KINL SHOW VERY DRY AIR
BELOW 700MB WHICH FITS WITH THE NAM AND GFS MODELS. THE RAP ALSO
SEEMS TO BE OVERDOING PRECIP CURRENTLY OVER CANADA COMPARING MODEL
OUTPUT TO SFC OBS. AND EVEN THE RAP HAS THE SHOWERS WEAKENING AS
THEY MOVE INTO THE CWA. THINK THAT WE WILL SEE SOME INCREASED
CLOUD COVER AND SOME VIRGA WITH THE FRONTAL BOUNDARY...BUT NOTHING
REACHING THE GROUND. MADE A FEW MINOR TWEAKS TO TEMPS BUT NO MAJOR
CHANGES.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 303 AM CST SUN NOV 24 2013
PRECIP CHANCES AND TEMPERATURES WILL BE THE MAIN FORECAST
CHALLENGE THROUGH THE PERIOD.
SFC TROUGH DEVELOPING OVER SASK HAS ALLOWED WINDS TO SHIFT BACK TO
THE SOUTH AND BECOMING QUITE BREEZY. THE WINDS HAVE HELPED TEMPS
CLIMB BACK INTO THE POSITIVE DIGITS...AND SHOULD HELP TEMPS CLIMB
INTO THE UPPER 20S TO LOW 30S THIS AFTERNOON. HOWEVER...AN
APPROACHING SHORTWAVE CAN BE SEEN ON WV LOOP COMING TOWARDS THE
REGION. CANADIAN RADAR SHOWS SOME ACTIVITY OVER CENTRAL
MANITOBA...AND MODELS HAVE SOME OF THIS PRECIP CLIPPING THE LAKE
OF THE WOODS AREA NEAR 12Z. IT IS UNCERTAIN HOW MUCH IS REACHING
THE GROUND AT THIS POINT...BUT WILL KEEP SOME LOW POPS GOING THIS
MORNING FOR OUR FAR NORTHEAST.
THE MAIN SHORTWAVE WILL DIG FURTHER SOUTH INTO MANITOBA
TODAY...AND INTO ONTARIO TONIGHT. THE UPPER SYSTEM SHOULD HELP
PUSH THE SFC TROUGH EASTWARD...WITH ANOTHER COLD FRONT MOVING INTO
THE REGION THIS EVENING. A FEW OF THE SHORT RANGE MODELS HAVE SOME
PRECIP DEVELOPING AHEAD OF THE FRONT THIS AFTERNOON...MAINLY OVER
THE NORTHERN CWA. HOWEVER...THERE IS QUITE A BIT OF DRY AIR AT LOW
LEVELS...AND AT THIS POINT IT SEEMS LIKE NOTHING WILL REACH THE
GROUND. THE LARGER SCALE MODELS ALL KEEP US DRY. WILL LEAVE A
MENTION OUT FOR NOW BUT KEEP A CLOSE EYE...AS MODEL THERMAL
PROFILES SHOW THAT FZRA COULD BE POSSIBLE IF ANYTHING DOES REACH
THE GROUND.
ANOTHER...STRONGER SHORTWAVE WILL MOVE INTO SOUTHERN MANITOBA FOR
MONDAY. PLENTY OF COLD AIR WILL BE MOVING BACK IN BEHIND THE
DEPARTING SFC LOW...KEEPING TEMPS IN THE TEENS SUNDAY NIGHT AND
THE 20S INTO MONDAY. THE APPROACHING SHORTWAVE WILL BRING AN
INCREASING CHANCE FOR SNOW SHOWERS TO OUR NORTHEASTERN CWA DURING
THE DAY ON MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 303 AM CST SUN NOV 24 2013
MONDAY NIGHT...THE SHORTWAVE OVER MANITOBA WILL DIG INTO THE GREAT
LAKES...BRINGING A CONTINUED CHANCE FOR SNOW OVER LAKE OF THE
WOODS AND DRAGGING ANOTHER SURGE OF COLD AIR BEHIND IT. THE AIR
MASS WILL BE QUITE COLD ALTHOUGH WITH CLOUDS AT NIGHT THINK WE
WILL NOT BE AS COLD AS SATURDAY MORNING. KEPT LOWS IN THE SINGLE
DIGITS AND HIGHS IN THE TEENS.
WEDNESDAY THROUGH SATURDAY NIGHT..NORTHWEST FLOW ALOFT CONTINUES
WITH CANADIAN SHORT-WAVE PASSING THROUGH THE NORTHERN PLAINS
WEDNESDAY AND FRIDAY NIGHT INTO SATURDAY. THE FIRST OF THESE IS
EXPECTED TO BE DRY WITH THE BEST MOISTURE/LIFT NORTH OF THE
INTERNATIONAL BORDER. THE SECOND MAY BRING A LOW CHANCE FOR LIGHT
SNOW FRIDAY NIGHT INTO SATURDAY...ALTHOUGH THERE ARE SOME MAJOR
DIFFERENCES BETWEEN THE 00 UTC GFS/ECMWF IN FRONTAL ORIENTATION/
LOCATION/TIMING. WILL FOLLOW ALL BLEND 20 POPS FOR NOW. WEDNESDAY
WILL BE THE COOLEST DAY OF THE PERIOD WITH A GRADUAL WARMING TREND
INTO THE WEEKEND. EVEN SO...DAILY HIGHS LIKELY TO REMAIN BELOW
FREEZING AND MAINLY IN THE 20S. OVERNIGHT LOWS WILL DROP INTO THE
TEENS EACH MORNING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 642 AM CST SUN NOV 24 2013
CONDITIONS WILL REMAIN VFR WITH INCREASING HIGH AND MID LEVEL
CLOUDS TODAY. CIGS SHOULD BE AT 10000 AT THE LOWEST DURING THE
AFTERNOON AS A COLD FRONT MOVES IN. SOUTH WINDS TODAY WILL BE
QUITE BREEZY AHEAD OF THE FRONT WITH GUSTS ABOVE 20 KTS BUT WILL
SHIFT TO THE WEST BY AFTERNOON AND THE NORTHWEST TONIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/ROGERS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1139 PM EST SAT NOV 23 2013
.SYNOPSIS...
LAKE EFFECT SHOWERS WILL INITIATE IN THE WAKE OF THE COLD FRONT
TONIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA FROM THE EAST
ON SUNDAY AND PERSIST THROUGH MONDAY. A COLD FRONT WILL MOVE
ACROSS THE AREA LATE MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
I WILL CONTINUE WITH THE CURRENT FORECAST TREND. THE HRRR MODEL
SEEMS TO BE HANDLING THE CURRENT LAKE EFFECT SITUATION WELL. IT
SHOWS TWO MAIN BANDS...ONE OVER NW PA AND ONE JUST EAST OF CLE.
THE RADAR SHOWS THIS TREND. THE MODEL SHOWS THE BAND EAST OF CLE
WEAKENING AFTER 06Z WITH THE BANDS OVER NW PA BECOMING DOMINATE.
THE WARNED AREA LOOKS GOOD. I AM A LITTLE UNEASY ABOUT
LAKE...GEAUGA...EASTERN CUYAHOGA AND THE NORTHERN SECTIONS OF
PORTAGE AND SUMMIT. CURRENT FORECAST OF 2 TO 4 INCHES LOOKS
REASONABLE BUT VALUES COULD CLIMB TO NEAR LAKE EFFECT ADVISORY
LEVELS IF THE BAND EAST OF CLEVELAND PERSISTS. I WILL CONTINUE
TO MONITOR BUT AN ADVISORY WILL NOT BE ISSUED WITH THIS UPDATE.
PREVIOUS DISCUSSION...
THE COLD FRONT IS CURRENTLY SOUTHEAST OF THE AREA. TEMPERATURES
WILL CONTINUE TO DROP STEADILY BEHIND THE FRONT DUE TO STRONG COLD
AIR ADVECTION. COLDER TEMPERATURES WILL LEAD TO EXTREME
INSTABILITY OVER LAKE ERIE...INITIATING LAKE EFFECT SNOW. THERE IS
STILL SOME QUESTION AS TO HOW STRONG THE LAKE EFFECT SNOW WILL
BECOME. 850 MB TEMPERATURES AROUND 25C WILL PROVIDE ENOUGH
INSTABILITY TO PRODUCE HEAVY SNOW...BUT MOISTURE WILL BE LIMITED
DUE TO SHORT FETCH WITH NORTHWEST WINDS. ONE WAY TO GET ADDED
MOISTURE IS FOR THE LAKE EFFECT TO DEVELOP A CONNECTION TO ANOTHER
LAKE. MODELS ARE HINTING AT A LAKE HURON CONNECTION WITH THIS
EVENT AND IF THAT OCCURS WE MAY GET THE ADDED MOISTURE NECESSARY
TO REALLY GET THINGS GOING.
SNOW ACCUMULATIONS ARE ALSO A BIT TRICKY AND DEPEND ON WHETHER OR
NOT WE GET THAT LAKE HURON CONNECTION. ASSUMING WE GET THE
CONNECTION...WE COULD SEE ANYWHERE FROM SIX INCHES TO OVER A FOOT
OF SNOW OVER EXTREME NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA. THE
AREAS MOST LIKELY TO SEE OVER A FOOT OF SNOW ARE THE IN THE HIGHER
TERRAIN OF NORTHWEST PENNSYLVANIA WHERE UPSLOPE FLOW WILL ENHANCE
THE LAKE EFFECT SNOW. SEVERAL SECONDARY BANDS MAY DEVELOP TO THE
WEST OF THE PRIMARY BAND. THE SECONDARY BANDS DO NOT LOOK LIKE THEY
WILL PRODUCE ENOUGH SNOW TO REACH ADVISORY CRITERIA. THE EVENING
SHIFT WILL CONTINUE TO MONITOR THE SITUATION AS IT EVOLVES AND ISSUE
AN ADVISORY IF THEY BELIEVE IT TO BE NECESSARY.
AS FOR TEMPERATURES TONIGHT...COLD AIR ADVECTION WILL CONTINUE
OVERNIGHT WITH OVERNIGHT LOWS REACHING INTO THE TEENS FOR MANY
LOCATIONS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
HIGH PRESSURE WILL MOVE EAST INTO THE AREA ON SUNDAY...HELPING TO
TAPER THE LAKE EFFECT SNOW SUNDAY EVENING. WE WILL GET A BRIEF
RESPITE FROM THE SNOW ON MONDAY AS THE HIGH PRESSURE SLIDES EAST.
A COLD FRONT WILL CROSS THE AREA LATE MONDAY NIGHT INTO TUESDAY
MORNING. NOT EXPECTING MUCH IN THE WAY OF SNOW WITH THE FRONTAL
PASSAGE. FOR NOW...GOING WITH A CHANCE OF SNOW SHOWERS FOR MOST OF
THE FORECAST AREA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
COLD AND MAINLY QUIET WEATHER IS EXPECTED DURING THE LONG TERM
PERIOD. SOME LAKE EFFECT IS POSSIBLE TUESDAY NIGHT INTO WEDNESDAY
BUT WINDS QUICKLY BECOME UNFAVORABLE ON WEDNESDAY EVENING. IT
APPEARS THAT MOST OF THE LAKE EFFECT WILL BE NUISANCE TYPE
ACTIVITY AND AM NOT ANTICIPATING ANY HEADLINES. THURSDAY THROUGH
SATURDAY LOOK TO BE DRY. HIGH TEMPS DURING THE PERIOD WILL
CONTINUE TO BE 10 TO 15 DEGREES BELOW NORMAL.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
LIMITED LAKE EFFECT WITH REALLY DRY AIR WORKING INTO THE AREA.
DEWPOINTS ARE IN THE SINGLE DIGITS. ERIE AND VICINITY WILL HAVE
THE HEAVIEST LAKE EFFECT AS A LAKE EFFECT SNOW BAND WITH
CONNECTIONS TO LAKE HURON WOBBLES BETWEEN THE OH/PA BORDER AND
ERI. THIS WILL PRODUCE PREDOMINATELY IFR CONDITIONS. OUTSIDE OF
THIS BAND SNOW SHOWERS ARE HIT OR MISS AND WITH NON VFR CONDITIONS
BRIEF AND TEMPORARY. GUSTS FROM CLE/CAK EASTWARD WILL CONTINUE
OVERNIGHT TO BE AROUND 25 KTS TO OCCASIONALLY 30 KNOTS. FOR SUNDAY
HIGH PRESSURE BEGINS TO BUILD INTO THE OHIO VALLEY...TAPERING THE
LAKE EFFECT FURTHER AND DIMINISHING WINDS AND BRINGING THEM AROUND
TO THE WEST. FAR EASTERN SITES WILL SEE THIS TAKE PLACE NEAR OR
AFTER 00Z MON. LARGELY VFR SUNDAY...WITH THE EXCEPTION OF THE
LIMITED LAKE EFFECT ACROSS FAR NE OH/NW PA.
OUTLOOK...NON VFR MAINLY OVER NE OH AND NW PA SUNDAY NIGHT
BECAUSE OF LAKE EFFECT. MORE WIDESPREAD SYNOPTIC SNOW EXPECTED
LATE MONDAY NIGHT INTO TUESDAY AND CONTINUING ACROSS NE OH/NW PA
ON WEDNESDAY IN LAKE EFFECT SHSN...AND THEREFORE NON-VFR
CONDITIONS.
&&
.MARINE...
HAVE ISSUED THE GALE WARNING FOR THE CENTRAL AND EASTERN PORTIONS
OF LAKE ERIE. WINDS QUICKLY RAMPED UP ABOVE 30 KNOTS AND HAVE BEEN
GALE FORCE. THE OUTLOOK FOR THE REMAINDER OF THE NIGHT IS LOW END
GALES...DIMINISHING SUNDAY MORNING. THE FLOW WILL FINALLY BECOME
WEST SUNDAY EVENING AND THEN SW BY DAYBREAK MONDAY AS HIGH
PRESSURE BUILDS IN FROM THE SOUTH. SOUTHWEST FLOW IS EXPECTED TO
CONTINUE TILL ANOTHER COLD FRONT CROSSES THE LAKE ON TUESDAY. THIS
WILL BRING MORE CHANCES FOR PRECIP AND NW FLOW BACK TO THE LAKE.
WINDS WILL BECOME NORTHERLY ON WEDNESDAY AND NE ON THURSDAY S
ARCTIC HIGH PRESSURE BUILDS IN FROM THE NORTH.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW WARNING UNTIL MIDNIGHT EST SUNDAY NIGHT FOR
OHZ014-089.
PA...LAKE EFFECT SNOW WARNING UNTIL MIDNIGHT EST SUNDAY NIGHT FOR
PAZ001>003.
MARINE...GALE WARNING UNTIL 4 AM EST SUNDAY FOR LEZ061-146>149-166>169.
SMALL CRAFT ADVISORY UNTIL 11 AM EST TUESDAY FOR LEZ142>145.
&&
$$
SYNOPSIS...SCHEPEL
NEAR TERM...GARNET
SHORT TERM...SCHEPEL
LONG TERM...KUBINA
AVIATION...OUDEMAN
MARINE...KUBINA/OUDEMAN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
850 PM CST MON NOV 25 2013
.UPDATE...
STRATUS SHIELD CONTS TO SLIDE SE ACROSS NERN PART OF SOUTH DAKOTA
OVERNIGHT...CREATING A DIFFICULT FORECAST FOR OVERNIGHT LOWS.
TEMPS UNDER THE CLOUD SHIELD HAVE NOT FALLEN OFF GREATLY FROM THE
AFTERNOON READINGS...WITH TEMPS AOA 30 DEGREES AND HOLDING STEADY.
FURTHER SW...CLEAR SKIES ARE ENABLING TEMPS IN THE FAR SW CWA TO
FALL...ALBEIT SLOWLY...BUT FALLING NONE THE LESS. THE PROBLEM
ARISES WHEN TRYING TO TIME THE BACK EDGE OF THE CLOUD SHIELD AS IT
HAS PUSHED INTO NRN ND ATTM WITH TEMPS ACROSS SRN CANADA IN THE
SINGLE DIGITS ABOVE ZERO. SENT OUT EARLIER UPDATE TO SLOW THE TEMP
FALL ACROSS THE CWA...AND RAISE LOWS ABOUT A CATEGORY ACROSS THE
NE. ALSO MANUALLY ADJUSTED THE HOURLY TEMP GRIDS...KEEPING TEMPS
UP THROUGH 10Z OR SO...THEN IN ANTICIPATION OF CLEARING
LINE...ALLOWED TEMPS TO FALL TO FORECAST LOWS AROUND 13Z TO 14Z.
ISOLD FLURRIES ARE STILL BEING REPORTED ACROSS ERN SECTIONS OF
ND...AND STILL SEEMS PRUDENT TO KEEP THEM IN ONGOING FCST. ALSO
TWEAKED SKY GRIDS TO BETTER MATCH CURRENT CLOUD SHIELD LOCATION
AND WINDS ARE ALSO STAYING UP JUST A BIT. UPDATED ZONE FORECAST
SENT OUT EARLIER.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
LEADING EDGE OF THE STRATUS/STRATOCUMULUS DECK IS FIRMLY IN PLACE
ACROSS THE EASTERN CWA...WITH A MASSIVE EXPANSION BACK TO THE
NORTH INTO CANADA. MAIN FORECAST ISSUES OVERNIGHT WILL BE CLOUD
COVER AND THE ONSET OF STRONGER COLD AIR ADVECTION. RUC13 900-850
MB RH HAS A VERY GOOD HANDLE ON CURRENT STRATUS OVER THE REGION SO
USED THAT AS A FORECAST FOR THE OVERNIGHT PERIOD. IT BASICALLY
SHOWS THE STRATUS SLOWLY OOZING SOUTHWEST ACROSS SOUTH DAKOTA
THROUGH 12Z TUESDAY. HAVE INCREASED SKY COVER FROM PREVIOUS
FORECAST AND MAY NEED TO BE BEEFED UP MORE FOR EVENING UPDATES.
WITH ADDITIONAL WEAK SHORTWAVE ENERGY MOVING SOUTH OVER THE AREA
LATE TONIGHT AND THE STRONGER COLD AIR ADVECTION...SEE NO REASON
WHY CLOUDS WOULD BREAK UP OR CEASE TO MOVE ANY FURTHER
SOUTH/SOUTHWEST INTO TUESDAY MORNING. LEFT IN THE MENTION OF
FLURRIES FOR THE EASTERN CWA LATE TONIGHT THROUGH TUESDAY MORNING
IN ASSOCIATION WITH THE WEAK SHORTWAVE ENERGY. CURRENT OBS ACROSS
NORTHEAST ND AND SOUTHERN CANADA SHOW -SN WITH VSBYS GENERALLY
ABOVE 6SM IN ASSOCIATION WITH THE WEAK WAVE. WITH THE ONSET OF
COLDER AIR ALOFT ON TUESDAY...WILL SEE HIGH TEMPS SEVERAL DEGREES
COLDER THAN MONDAY. READINGS WILL BE IN THE TEENS TO MID 20S
ACROSS THE CWA. SURFACE HIGH THEN MOVES THROUGH THE AREA TUESDAY
NIGHT WHICH SHOULD CLEAR THE SKIES AND PROVIDE FOR A PERIOD OF
LIGHT WINDS. ALTHOUGH THE RIDGE AXIS IS PRETTY NARROW AND A QUICK
MOVER...SO BY 12Z WEDNESDAY MUCH OF THE CWA IS ALREADY UNDER
SOUTHERLY SFC WIND FLOW. NOT AN IDEAL RADIATIONAL COOLING
SETUP...BUT WILL STILL GET PRETTY COLD NONETHELESS. WILL BE AROUND
0 DEGREES ACROSS THE EASTERN CWA WITH FAVORED COLD SPOTS PERHAPS
SNEAKING BELOW ZERO. HIGHS ON WEDNESDAY WILL REBOUND SOMEWHAT AS
925MB TEMPS BEGIN TO WARM ON THE BACKSIDE OF THE RETREATING SFC
HIGH. BREEZY WINDS WILL DEVELOP SO THERE WILL BE DECENT MIXING.
HIGHS WILL REMAIN BELOW NORMAL THOUGH AS THE OVERALL PATTERN
REMAINS COLD.
.LONG TERM...THURSDAY THROUGH SUNDAY
NORTHWEST FLOW ALOFT WILL BE THE PREDOMINATE UPPER PATTERN
THROUGH MOST OF THE LONG TERM PERIOD...BUT A PATTERN CHANGE
DOES SEEM TO BE ON THE HORIZON. A SHORTWAVE TROUGH DROPPING OUT
OF CANADA WILL INFLUENCE THE REGION FOR THE FRIDAY/SATURDAY TIME
FRAME...HOWEVER MOST OF THE FORCING APPEARS TO REMAIN NORTH OF OUR
CWA...AND MODEL MOISTURE PROFILES REMAIN FAIRLY DRY AT THIS POINT.
DECENT WARM AIR ADVECTION AHEAD OF THAT WAVE COULD CAUSE SOME
PTYPE ISSUES IF PRECIPITATION WERE TO MATERIALIZE OVER OUR CWA
SATURDAY. ALTHOUGH MODELS VARY ON THE STRENGTH OF THE WARM
PUSH...850 MB TEMPERATURES DO RISE ABOVE 0 C...WITH THE GFS
ADVERTISING AS HIGH AS 6 OR 7 C ACROSS OUR SOUTHERN CWA.
EITHER WAY...CONTINUED WITH THE DRY ALLBLEND FORECAST FOR NOW. BY
SUNDAY WEAK RIDING APPEARS TO BE OVER THE NORTHERN PLAINS...BUT
IT ONLY PRECEDES A MORE SIGNIFICANT UPPER LOW MOVING INTO THE
PACIFIC NORTHWEST.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR/LOW VFR STRATUS CONTS TO MOVE SOUTHEAST THROUGH THE NERN PART
OF SOUTH DAKOTA. WITH NAM12 SHOWING WEAK 500HPA VORT MAX COMING
DOWN BACKSIDE OF WRN CONUS RIDGE...EXPECT DECK TO HOLD FIRM
THROUGH 12Z FOR THE KABR/KATY TERMINALS. UPSTREAM OBS SHOW ISOLD
AREAS OF LIGHT SNOW/FLURRIES...AND ALTHOUGH CANT RULE OUT ANY
LIGHT SNOW OCCURRING...IMPACT WILL BE MINIMAL WITH NO REDUCTION TO
VSBYS EXPECTED...SO HAVE LEFT ANY MENTION OUT. KPIR IS EXPECTED TO
BE VFR THROUGH VALID FORECAST PERIOD...WHILE KMBG WILL BE SCT-BKN
MVFR/LOW VFR THROUGH 12Z AS THEY RESIDE ON EDGE OF SAGGING STRATUS
DECK.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...HINTZ
SHORT TERM...TMT
LONG TERM...SERR
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
542 PM CST MON NOV 25 2013
.UPDATE...
00Z AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
LEADING EDGE OF THE STRATUS/STRATOCUMULUS DECK IS FIRMLY IN PLACE
ACROSS THE EASTERN CWA...WITH A MASSIVE EXPANSION BACK TO THE
NORTH INTO CANADA. MAIN FORECAST ISSUES OVERNIGHT WILL BE CLOUD
COVER AND THE ONSET OF STRONGER COLD AIR ADVECTION. RUC13 900-850
MB RH HAS A VERY GOOD HANDLE ON CURRENT STRATUS OVER THE REGION SO
USED THAT AS A FORECAST FOR THE OVERNIGHT PERIOD. IT BASICALLY
SHOWS THE STRATUS SLOWLY OOZING SOUTHWEST ACROSS SOUTH DAKOTA
THROUGH 12Z TUESDAY. HAVE INCREASED SKY COVER FROM PREVIOUS
FORECAST AND MAY NEED TO BE BEEFED UP MORE FOR EVENING UPDATES.
WITH ADDITIONAL WEAK SHORTWAVE ENERGY MOVING SOUTH OVER THE AREA
LATE TONIGHT AND THE STRONGER COLD AIR ADVECTION...SEE NO REASON
WHY CLOUDS WOULD BREAK UP OR CEASE TO MOVE ANY FURTHER
SOUTH/SOUTHWEST INTO TUESDAY MORNING. LEFT IN THE MENTION OF
FLURRIES FOR THE EASTERN CWA LATE TONIGHT THROUGH TUESDAY MORNING
IN ASSOCIATION WITH THE WEAK SHORTWAVE ENERGY. CURRENT OBS ACROSS
NORTHEAST ND AND SOUTHERN CANADA SHOW -SN WITH VSBYS GENERALLY
ABOVE 6SM IN ASSOCIATION WITH THE WEAK WAVE. WITH THE ONSET OF
COLDER AIR ALOFT ON TUESDAY...WILL SEE HIGH TEMPS SEVERAL DEGREES
COLDER THAN MONDAY. READINGS WILL BE IN THE TEENS TO MID 20S
ACROSS THE CWA. SURFACE HIGH THEN MOVES THROUGH THE AREA TUESDAY
NIGHT WHICH SHOULD CLEAR THE SKIES AND PROVIDE FOR A PERIOD OF
LIGHT WINDS. ALTHOUGH THE RIDGE AXIS IS PRETTY NARROW AND A QUICK
MOVER...SO BY 12Z WEDNESDAY MUCH OF THE CWA IS ALREADY UNDER
SOUTHERLY SFC WIND FLOW. NOT AN IDEAL RADIATIONAL COOLING
SETUP...BUT WILL STILL GET PRETTY COLD NONETHELESS. WILL BE AROUND
0 DEGREES ACROSS THE EASTERN CWA WITH FAVORED COLD SPOTS PERHAPS
SNEAKING BELOW ZERO. HIGHS ON WEDNESDAY WILL REBOUND SOMEWHAT AS
925MB TEMPS BEGIN TO WARM ON THE BACKSIDE OF THE RETREATING SFC
HIGH. BREEZY WINDS WILL DEVELOP SO THERE WILL BE DECENT MIXING.
HIGHS WILL REMAIN BELOW NORMAL THOUGH AS THE OVERALL PATTERN
REMAINS COLD.
.LONG TERM...THURSDAY THROUGH SUNDAY
NORTHWEST FLOW ALOFT WILL BE THE PREDOMINATE UPPER PATTERN
THROUGH MOST OF THE LONG TERM PERIOD...BUT A PATTERN CHANGE
DOES SEEM TO BE ON THE HORIZON. A SHORTWAVE TROUGH DROPPING OUT
OF CANADA WILL INFLUENCE THE REGION FOR THE FRIDAY/SATURDAY TIME
FRAME...HOWEVER MOST OF THE FORCING APPEARS TO REMAIN NORTH OF OUR
CWA...AND MODEL MOISTURE PROFILES REMAIN FAIRLY DRY AT THIS POINT.
DECENT WARM AIR ADVECTION AHEAD OF THAT WAVE COULD CAUSE SOME
PTYPE ISSUES IF PRECIPITATION WERE TO MATERIALIZE OVER OUR CWA
SATURDAY. ALTHOUGH MODELS VARY ON THE STRENGTH OF THE WARM
PUSH...850 MB TEMPERATURES DO RISE ABOVE 0 C...WITH THE GFS
ADVERTISING AS HIGH AS 6 OR 7 C ACROSS OUR SOUTHERN CWA.
EITHER WAY...CONTINUED WITH THE DRY ALLBLEND FORECAST FOR NOW. BY
SUNDAY WEAK RIDING APPEARS TO BE OVER THE NORTHERN PLAINS...BUT
IT ONLY PRECEDES A MORE SIGNIFICANT UPPER LOW MOVING INTO THE
PACIFIC NORTHWEST.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR/LOW VFR STRATUS CONTS TO MOVE SOUTHEAST THROUGH THE NERN PART
OF SOUTH DAKOTA. WITH NAM12 SHOWING WEAK 500HPA VORT MAX COMING
DOWN BACKSIDE OF WRN CONUS RIDGE...EXPECT DECK TO HOLD FIRM
THROUGH 12Z FOR THE KABR/KATY TERMINALS. UPSTREAM OBS SHOW ISOLD
AREAS OF LIGHT SNOW/FLURRIES...AND ALTHOUGH CANT RULE OUT ANY
LIGHT SNOW OCCURRING...IMPACT WILL BE MINIMAL WITH NO REDUCTION TO
VSBYS EXPECTED...SO HAVE LEFT ANY MENTION OUT. KPIR IS EXPECTED TO
BE VFR THROUGH VALID FORECAST PERIOD...WHILE KMBG WILL BE SCT-BKN
MVFR/LOW VFR THROUGH 12Z AS THEY RESIDE ON EDGE OF SAGGING STRATUS
DECK.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...HINTZ
SHORT TERM...TMT
LONG TERM...SERR
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
701 PM CST MON NOV 25 2013
.UPDATE...
ISSUED A WINTER WEATHER ADVISORY THROUGH THE EVENING AS AN AREA OF
LIGHT FREEZING DRIZZLE AND FOG WAS SPREADING SOUTHWARD THROUGH
MOST OF THE AREA. ALSO EXPECT FLURRIES. MOST SOLUTIONS DIMINISH
THE SHALLOW LIFT AND THIN THE NEAR-SURFACE MOIST LAYER AROUND
MIDNIGHT. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 547 PM CST MON NOV 25 2013/
AVIATION...
A LOW STRATUS LAYER BEHIND THIS AFTERNOONS COLD FRONT WAS EDGING
SOUTHWARD TOWARDS KLBB EARLY THIS EVENING AND SHOULD MAKE IT INTO
KLBB VERY SHORTLY AFTER 00Z. LATEST RAP SOUNDINGS STEADILY LOWER
CEILING AT KLBB TO LIFR LEVELS EARLY THIS EVENING...THOUGH THE
HRRR RUN REVEALS LESS CERTAINTY. WE HAVE CONTINUED PREVIOUS IDEA
OF AN LIFR LAYER THIS EVENING INTO KLBB...AND EVEN ADDED TEMP
LIGHT FOG AND FREEZING DRIZZLE BASED ON UPSTREAM REPORTS. THERE IS
ALSO A LOW RISK OF A HARD DROP IN VISIBILITY AS THIS IS EMANATING
OFF THE HEAVY SNOW FIELD...THOUGH NOT EXPLICIT FOR KLBB IN ANY
GUIDANCE AT THE MOMENT. FOR KCDS...THE CURRENT IFR/LIFR CIG SHOULD
HOLD FOR SEVERAL HOURS BEFORE BREAKING...AT LEAST BASED ON SHORT
RANGE MODEL TRENDS. UNCERTAIN FOR KCDS IS IF FOG COULD REDEVELOP
LATER TONIGHT PER RAP SURFACE HUMIDITY PROGS. WILL STUDY FURTHER
FOR 06Z CYCLE. CONDITIONS EXPECTED TO BE ALL VFR TUESDAY. RMCQUEEN
PREV DISCUSSION... /ISSUED 300 PM CST MON NOV 25 2013/
SHORT TERM...
UPPER LEVEL LOW WHICH HELPED FEED MOISTURE IN FOR THE WEEKEND WINTER
WEATHER STORM WAS OVER THE PANHANDLE AT MID DAY. THE LOW CENTER
WILL MAKE AN INTERESTING TRAJECTORY DIGGING SOUTHWARD THIS EVENING
AND MAKING IT INTO THE TX HILL COUNTRY BY TUESDAY MORNING BEFORE
EJECTING NORTHEASTWARD AS IT PHASES WITH A MAIN STREAM DIVING
THROUGH MANITOBA THIS AFTERNOON. THIS WILL RESULT IN NORTHERLY FLOW
AND MUCH DRIER CONDITIONS SETTING IN. LOWS TONIGHT WILL BE TRICKY
AS SKIES ARE EXPECTED TO CLEAR NW TO SE AROUND SUNRISE TUESDAY
MORNING. GIVEN THE PROXIMITY OF THE UPPER LOW...WE MAY SEE A FEW
FLURRIES OVERNIGHT WINDS SHOULD REMAIN UP AROUND 10 KTS AND THOUGH
WIDESPREAD SNOWFALL REMAINS ON THE GROUND...COMBINATION OF SPEEDS
AND DOWNSLOPE TRAJECTORY SHOULD KEEP FOG THREAT TO A MINIMUM THOUGH
GIVEN THE SNOW-PACK...WILL GO AHEAD AND MENTION PATCHY FOG NORTHWEST.
SUNNY AND MUCH WARMER TUESDAY.
LONG TERM...
HIGH AMPLITUDE RIDGE IN PLACE ACROSS THE ROCKIES TO BEGIN THE
EXTENDED PERIOD TUESDAY NIGHT AND WEDNESDAY. SHOULD BE RATHER COLD
AGAIN OVER DEEPER SNOW-PACK SRN PANHANDLE WITH TEMPS AGAIN IN THE
TEENS. IF WINDS ARE LIGHT ENOUGH...COULD SEE SOME SINGLE DIGITS.
40S AREAWIDE FOR HIGHS WEDNESDAY...AND THEN 50S ON THURSDAY AS
FLAT UPPER RIDGE AXIS MOVES EAST OVER THE CENTRAL AND SOUTHERN PLAINS.
MAY BE PUSHING 55-60 DEGREES SOUTH BY FRIDAY AS SURFACE LEE TROUGH
DEEPENS FROM ERN CO INTO NERN NM AND WEST TEXAS. NEXT SYSTEM OF
INTEREST IS POS TILTED OPEN WAVE THAT WILL APPROACH THE AREA OVER
THE WEEKEND. SHOULD BEGIN TO SEE SOME MOISTURE RETURN LATE FRIDAY
AND SATURDAY AS SOUTHERLY WINDS INCREASE...LIKELY SOME LOW CLOUDS
CENTRAL AND EAST SECTIONS. GFS FOR NOW KEEPS SHOWERS EAST OF THE
AREA. MAY SEE FRONT INTO AREA ON SUNDAY. PROGRESSIVE NATURE OF
SYSTEM LIKELY MEANS A DRY FRONT...AND ONLY SLIGHT COOL-DOWN.
BOTH GFS AND PREV ECMWF ADVERTISING BIG PATTERN CHANGE WEDNESDAY OF
NEXT WEEK (DEC. 4) WITH CRASHING HEIGHTS OVER THE WESTERN CONUS. IF
SOME SEMBLANCE OF THIS PATTERN IS REALIZED...COULD TURN MUCH COLDER
AROUND THIS TIME...WITH WINTER WEATHER POSSIBLY MAKING A RETURN.
DOES BEAR WATCHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 14 36 17 39 23 / 10 0 0 0 0
TULIA 19 38 18 39 23 / 10 0 0 0 0
PLAINVIEW 22 41 20 44 25 / 10 0 0 0 0
LEVELLAND 21 45 20 44 25 / 10 0 0 0 0
LUBBOCK 23 45 22 48 27 / 10 0 0 0 0
DENVER CITY 23 46 23 48 25 / 10 0 0 0 0
BROWNFIELD 23 46 22 48 25 / 10 0 0 0 0
CHILDRESS 23 47 24 45 26 / 10 0 0 0 0
SPUR 26 48 22 48 27 / 10 0 0 0 0
ASPERMONT 25 49 26 48 29 / 10 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE
FOLLOWING ZONES: TXZ021>037-039>042.
&&
$$
05/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
547 PM CST MON NOV 25 2013
.AVIATION...
A LOW STRATUS LAYER BEHIND THIS AFTERNOONS COLD FRONT WAS EDGING
SOUTHWARD TOWARDS KLBB EARLY THIS EVENING AND SHOULD MAKE IT INTO
KLBB VERY SHORTLY AFTER 00Z. LATEST RAP SOUNDINGS STEADILY LOWER
CEILING AT KLBB TO LIFR LEVELS EARLY THIS EVENING...THOUGH THE
HRRR RUN REVEALS LESS CERTAINTY. WE HAVE CONTINUED PREVIOUS IDEA
OF AN LIFR LAYER THIS EVENING INTO KLBB...AND EVEN ADDED TEMP
LIGHT FOG AND FREEZING DRIZZLE BASED ON UPSTREAM REPORTS. THERE IS
ALSO A LOW RISK OF A HARD DROP IN VISIBILITY AS THIS IS EMANATING
OFF THE HEAVY SNOW FIELD...THOUGH NOT EXPLICIT FOR KLBB IN ANY
GUIDANCE AT THE MOMENT. FOR KCDS...THE CURRENT IFR/LIFR CIG SHOULD
HOLD FOR SEVERAL HOURS BEFORE BREAKING...AT LEAST BASED ON SHORT
RANGE MODEL TRENDS. UNCERTAIN FOR KCDS IS IF FOG COULD REDEVELOP
LATER TONIGHT PER RAP SURFACE HUMIDITY PROGS. WILL STUDY FURTHER
FOR 06Z CYCLE. CONDITIONS EXPECTED TO BE ALL VFR TUESDAY. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 300 PM CST MON NOV 25 2013/
SHORT TERM...
UPPER LEVEL LOW WHICH HELPED FEED MOISTURE IN FOR THE WEEKEND WINTER
WEATHER STORM WAS OVER THE PANHANDLE AT MID DAY. THE LOW CENTER
WILL MAKE AN INTERESTING TRAJECTORY DIGGING SOUTHWARD THIS EVENING
AND MAKING IT INTO THE TX HILL COUNTRY BY TUESDAY MORNING BEFORE
EJECTING NORTHEASTWARD AS IT PHASES WITH A MAIN STREAM DIVING
THROUGH MANITOBA THIS AFTERNOON. THIS WILL RESULT IN NORTHERLY FLOW
AND MUCH DRIER CONDITIONS SETTING IN. LOWS TONIGHT WILL BE TRICKY
AS SKIES ARE EXPECTED TO CLEAR NW TO SE AROUND SUNRISE TUESDAY
MORNING. GIVEN THE PROXIMITY OF THE UPPER LOW...WE MAY SEE A FEW
FLURRIES OVERNIGHT WINDS SHOULD REMAIN UP AROUND 10 KTS AND THOUGH
WIDESPREAD SNOWFALL REMAINS ON THE GROUND...COMBINATION OF SPEEDS
AND DOWNSLOPE TRAJECTORY SHOULD KEEP FOG THREAT TO A MINIMUM THOUGH
GIVEN THE SNOW-PACK...WILL GO AHEAD AND MENTION PATCHY FOG NORTHWEST.
SUNNY AND MUCH WARMER TUESDAY.
LONG TERM...
HIGH AMPLITUDE RIDGE IN PLACE ACROSS THE ROCKIES TO BEGIN THE
EXTENDED PERIOD TUESDAY NIGHT AND WEDNESDAY. SHOULD BE RATHER COLD
AGAIN OVER DEEPER SNOW-PACK SRN PANHANDLE WITH TEMPS AGAIN IN THE
TEENS. IF WINDS ARE LIGHT ENOUGH...COULD SEE SOME SINGLE DIGITS.
40S AREAWIDE FOR HIGHS WEDNESDAY...AND THEN 50S ON THURSDAY AS
FLAT UPPER RIDGE AXIS MOVES EAST OVER THE CENTRAL AND SOUTHERN PLAINS.
MAY BE PUSHING 55-60 DEGREES SOUTH BY FRIDAY AS SURFACE LEE TROUGH
DEEPENS FROM ERN CO INTO NERN NM AND WEST TEXAS. NEXT SYSTEM OF
INTEREST IS POS TILTED OPEN WAVE THAT WILL APPROACH THE AREA OVER
THE WEEKEND. SHOULD BEGIN TO SEE SOME MOISTURE RETURN LATE FRIDAY
AND SATURDAY AS SOUTHERLY WINDS INCREASE...LIKELY SOME LOW CLOUDS
CENTRAL AND EAST SECTIONS. GFS FOR NOW KEEPS SHOWERS EAST OF THE
AREA. MAY SEE FRONT INTO AREA ON SUNDAY. PROGRESSIVE NATURE OF
SYSTEM LIKELY MEANS A DRY FRONT...AND ONLY SLIGHT COOL-DOWN.
BOTH GFS AND PREV ECMWF ADVERTISING BIG PATTERN CHANGE WEDNESDAY OF
NEXT WEEK (DEC. 4) WITH CRASHING HEIGHTS OVER THE WESTERN CONUS. IF
SOME SEMBLANCE OF THIS PATTERN IS REALIZED...COULD TURN MUCH COLDER
AROUND THIS TIME...WITH WINTER WEATHER POSSIBLY MAKING A RETURN.
DOES BEAR WATCHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 18 43 17 39 23 / 10 0 0 0 0
TULIA 21 42 18 39 23 / 10 0 0 0 0
PLAINVIEW 22 43 20 44 25 / 10 0 0 0 0
LEVELLAND 21 45 20 44 25 / 10 0 0 0 0
LUBBOCK 23 45 22 48 27 / 10 0 0 0 0
DENVER CITY 23 46 23 48 25 / 10 0 0 0 0
BROWNFIELD 23 46 22 48 25 / 10 0 0 0 0
CHILDRESS 23 47 24 45 26 / 10 0 0 0 0
SPUR 26 48 22 48 27 / 10 0 0 0 0
ASPERMONT 25 49 26 48 29 / 10 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1235 PM CST SUN NOV 24 2013
.DISCUSSION...
18Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
AN APPROACHING WEAK SHORTWAVE DISTURBANCE IS THE IMPETUS TO A
LIGHT RAIN SHIELD THAT WILL BE AFFECTING THE MORE NORTHERN TERMINALS
THROUGH 21Z THIS AFTERNOON. VFR OVERCAST THROUGH THE AFTERNOON...
LOWERING CEILINGS THIS EVENING INTO MVFR CAT/BORDERLINE IFR FROM
25/09Z INTO SUNRISE. NORTHERN COUNTY MODEL PROFILES ARE TRENDING
WARMER...WITH A THIN FREEZING OFF-THE-SURFACE LAYER EARLY MONDAY
MORNING. THUS...NO MENTION OF FROZEN PRECIP MIX IN KCLL AND KUTS
TAFS AT THIS TIME. A BROAD UPPER LOW OVER ARIZONA WILL ADVANCE
INTO THE TEXAS PANHANDLE OVER THE NEXT 24 HOURS. AHEAD OF THIS
FEATURE...A DEVELOPING CENTRAL TEXAS SURFACE TROUGH WITH WARMER
MOIST MID-LEVEL AIR OVERUNNING COOLER SFC AIR WILL AID IN INITIATING
NORTH-TO-SOUTH RAINFALL AS EARLY AS THE PRE-DAWN HOURS. MID-LATE
MONDAY MORNING INTO EARLY AFTERNOON IS TIMED TO BE WHEN MANY HUBS
EXPERIENCE HIGH IFR/LOW MVFR CONDITIONS WITHIN HEAVIER RAIN EPISODES.
31
&&
.PREV DISCUSSION... /ISSUED 1118 AM CST SUN NOV 24 2013/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
12Z UPPER AIR DATA SHOWS GREATER SATURATION AT 850 MB AND 700 MB
THAT YESTERDAY. A WELL DEFINED S/WV IS ALSO NOTED AT BOTH 850 MB
AND 700 MB. THE RAP 13 SHOWS AN AREA OF PRECIP MOVING INTO THE
REGION THIS AFTN INTO THIS EVENING BUT THERE IS LAYER OF VERY DRY
AIR NEAR THE SURFACE THAT WILL NEED TO BE OVERCOME. THINK CHANCE
POPS ARE THE WAY TO GO AND WILL TAPER HIGHER POPS WEST AND LOWER
POPS EAST. WINDS HAVE DROPPED OFF AND ALLOWED THE WIND ADVISORY TO
EXPIRE. 43
&&
PREV DISCUSSION... /ISSUED 454 AM CST SUN NOV 24 2013/
DISCUSSION...
COLDER AIRMASS CONTINUES TO DEEPEN OVER SE TX FROM NE TO SW.
AIRMASS IS BECOMING DRIER AND PERHAPS DRIER THAN PREVIOUSLY
FORECASTED BY SHORT RANGE MODELS. MIDNIGHT SFC ANALYSIS HAS 1042MB
SFC HIGH OVER THE C PLAINS HEADED INTO THE MIDWEST. DUE TO THE
DRIER BOUNDARY LAYER...NOT EXPECTING MUCH IN THE WAY OF PRECIP
TODAY WITH LOW/MID LEVEL CLOUD DECK. COLD ADVECTION AND CLOUD
COVER WILL KEEP MAX TEMPS IN THE 40S TODAY.
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY SHOW CLOSED UPPER LOW
OVER THE DESERT SW. SEEMS THE LOW HAS WEAKEN A TOUCH WITH 500MB
HEIGHTS A BIT HIGHER THAN 24 HRS AGO. THAT SAID...LEAD JET STREAK
AND SHORT WAVE ARE CAUSING FROZEN PRECIP OVER W TX INTO C TX THIS
MORNING. THIS LEAD SHORT WAVE DOES NOT SEEM QUITE AS STRONG AS
PREVIOUS MODEL RUNS HAD INDICATED. SEEMS THAT PRECIP OVERNIGHT MAY
NOT QUITE AS GREAT AND LARGE SCALE LIFT IS NOT AS STRONG. AS SUCH
IT WILL TAKE LONGER FOR THE BOUNDARY LAYER TO MOISTEN THROUGH WET
BULB THERMODYNAMICS. DO NOT THINK THE THREAT FOR RAIN/SLEET OR
FREEZING RAIN MIX WILL BE THAT HIGH MONDAY MORNING. MODEL
SOUNDINGS FROM NAM/GFS STILL SUPPORT MIXED PRECIP TYPE FROM
COLLEGE STATION TO CROCKETT BUT THAT MAY BE A BIT MORE OF A
STRETCH. LIKELY HAVE ALL RAIN IN THESE AREAS. MIN TEMPS WILL BE
TRICKY AS WELL. WILL STICK CLOSER TO COLDER GFS MOS NUMBERS IN
FORECAST BUT MAY NEED SOME THERMODYNAMICS TO HELP GET THAT COLD
AT THE SURFACE. IF THAT HAPPENS WHILE NO ACCUMULATION IS
EXPECTED...IMPACTS WILL BE FOR ELEVATED BRIDGES/OVERPASSES WITH A
LIGHT GLAZE IF ANYTHING.
ON MONDAY MAIN UPPER LEVEL JET AND UPPER LEVEL LOW BEGIN TO MOVE
INTO THE AREA. LARGE SCALE ASCENT WILL ONLY INCREASE WITH LARGE
OMEGA AND QUITE A BIT OF Q-VECTOR CONVERGENCE SPREADING OVER THE
AREA. ISENTROPIC LIFT OVER STALLED FRONT IN THE GULF WILL ONLY
INCREASE DUE TO THE STRONG FORCING. NAM/ECMWF STILL KEEP COASTAL
LOW CLOSER TO THE COAST THAN THE GFS. NOTICED SEVERAL ENHANCED
RAIN BANDS THAT SET UP OVER THE AREA. CROSS-SECTIONS DO SHOW SOME
FRONTOGENETIC FORCING CO-LOCATED WITH AREAS OF POSSIBLE CSI. HI-
RES WRF-ARW SHOWS SOME VERY SIMILAR BANDED FEATURES AND WOULD NOT
BE SURPRISED IF THERE WERE SOME AREAS OF ENHANCED PRECIP DUE TO
BANDING. FORECAST WILL STICK WITH 80/90 POPS ON MONDAY. PRECIP
TOTALS AGAIN LOOK TO BE IN THE 1-2 INCH RANGE FOR MONDAY. FEEL
MOST AREAS SHOULD BE ABLE TO HANDLE THIS MUCH PRECIP ESPECIALLY
OVER 6-12 HRS. THE COASTAL LOW WILL ALSO SUPPORT EASTERLY WINDS TO
THE NORTH OF IT WHICH COULD INCREASE TIDE LEVELS. WILL AGAIN NEED
TO MONITOR FOR THE POSSIBILITY OF COASTAL FLOODING MON/TUE.
FORECASTING WINTER PRECIP FOR THE AREA ON TUESDAY IS NOT VERY
STRAIGHT FORWARD. ALL OF THE MODELS STILL HAVE THE UPPER LOW
TRACKING DIRECTLY OVER THE AREA. IF ANYTHING MAYBE TRACK A BIT
FARTHER SOUTH AS A VORT MAX OVER MEXICO HELPS PULL THE LOW SOUTH
MONDAY NIGHT. THE UPPER LOW MAY NOW EVEN BE ABOUT 6 HRS SLOWER
TRACKING ACROSS THE AREA. DO THINK THAT UPWARD VERTICAL MOTION
WILL BE LARGE OVER THE AREA BUT NOT SURE IF THERE WILL BE ENOUGH
MOISTURE FOR THE SYSTEM TO WORK WITH AND IF TEMPS IN THE LOW
LEVELS WILL BE COLD ENOUGH FOR FROZEN PRECIP. RIGHT NOW THINK
NORTHERN AREAS COULD SEE A RAIN/SLEET MIX FROM BASICALLY COLLEGE
STATION TO HUNTSVILLE TO LIVINGSTON. NAM/GFS/ECMWF JUST DO NOT
SEEM TO COOL 925/850MB TEMPS ENOUGH TO STRICTLY SUPPORT FROZEN
PRECIP LIKE RAIN/SLEET/SNOW MIX. BY 18Z TUE TO 00Z WED THE
MID/UPPER LEVELS OF THE ATMOSPHERE DRY OUT ENOUGH SO THAT ONLY
PRECIP WILL BE RAIN THAT MAY HAPPEN TO FALL THROUGH A SUB-FREEZING
LAYER THICK ENOUGH TO FREEZE. WITH THAT SAID...DO NOT WANT TO
UNDER-ESTIMATE THE EFFECTS OF DYNAMICAL LIFT FROM THE UPPER LOW
AND ANY WET BULBING THAT MAY OCCUR UNDER THE LOW. MAY NEED TO
MONITOR FURTHER BUT COULD SEE THE FROZEN PRECIP LINE DROP FARTHER
SOUTH ESPECIALLY IF THERE IS MORE MOISTURE TO WORK WITH AND IT
LOOKS LIKE TEMPS MAY BE COLD ENOUGH. OVERALL THINK ANY FROZEN
PRECIP WILL BE LIGHT AND SHOULD NOT ACCUMULATE. MAIN ISSUES MAY
STILL BE ELEVATED SURFACES LIKE OVERPASSES.
ATMOSPHERE REALLY DRIES OUT 00Z-12Z WED WITH NEXT FRONT PUSHING
THROUGH. HIGH PRESSURE THEN BUILDS INTO THE OZARKS WED NIGHT INTO
THUR. SHOULD HAVE CLEAR SKIES AND MUCH CALMER WINDS. LOOKS LIKE
THANKSGIVING DAY COULD START OUT WITH AN AREA WIDE FREEZE. EVEN
FRIDAY MORNING MAY HAVE SOME SPOTS WITH FREEZING TEMPS. BELOW
NORMAL TEMPS SHOULD CONTINUE INTO THE WEEKEND WITH RETURN FLOW
FINALLY SETTING UP NEXT SATURDAY INTO SUNDAY. 39
&&
MARINE...
STRONG NORTHEAST WINDS CONTINUE THIS MORNING ACROSS THE COASTAL
WATERS THIS MORNING AND ADVISORIES WILL CONTINUE FOR ALL WATERS
THROUGH MID MORNING. WINDS ALONG THE IMMEDIATE COAST WILL BEGIN TO
WEAKEN AND THE BAYS ARE EXPECTED TO FALL BELOW ADVISORY CRITERIA.
WINDS ACROSS THE COASTAL WATERS WILL REMAIN ABOVE ADVISORY
CRITERIA THROUGH THE DAY TODAY AND ADVISORIES WILL LIKELY NEED TO
BE CARRIED EVEN LONGER...PARTICULARLY FOR THE OFFSHORE WATERS
WHERE ADVISORY CONDITIONS ARE EXPECTED THROUGH MID WEEK. FORECAST
MODELS CONTINUE TO BRING THE UPPER LEVEL LOW FURTHER SOUTH WHICH
WILL SHIFT THE COASTAL LOW SOUTH OF OUR MARINE ZONES AND ALLOW FOR
NORTHEAST WINDS THROUGH TUESDAY WHICH WILL BECOME NORTHWESTERLY AS
THE UPPER LOW MOVES OFF TO OUR EAST. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 32 38 34 45 31 / 60 90 60 30 10
HOUSTON (IAH) 36 42 36 45 34 / 40 90 70 50 10
GALVESTON (GLS) 43 48 41 48 38 / 40 80 80 60 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH MONDAY AFTERNOON FOR
THE FOLLOWING ZONES: MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: GALVESTON BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM 6 PM CST THIS EVENING
THROUGH MONDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1118 AM CST SUN NOV 24 2013
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
12Z UPPER AIR DATA SHOWS GREATER SATURATION AT 850 MB AND 700 MB
THAT YESTERDAY. A WELL DEFINED S/WV IS ALSO NOTED AT BOTH 850 MB
AND 700 MB. THE RAP 13 SHOWS AN AREA OF PRECIP MOVING INTO THE
REGION THIS AFTN INTO THIS EVENING BUT THERE IS LAYER OF VERY DRY
AIR NEAR THE SURFACE THAT WILL NEED TO BE OVERCOME. THINK CHANCE
POPS ARE THE WAY TO GO AND WILL TAPER HIGHER POPS WEST AND LOWER
POPS EAST. WINDS HAVE DROPPED OFF AND ALLOWED THE WIND ADVISORY TO
EXPIRE. 43
&&
.PREV DISCUSSION... /ISSUED 538 AM CST SUN NOV 24 2013/
DISCUSSION...
SEE AVIATION FOR 12Z TAF DISCUSSION.
AVIATION...
VFR CONDITIONS AREAWIDE THIS MORNING AND THESE SHOULD PERSIST
THROUGH MUCH OF THE DAY WITH MID LEVEL OVERCAST. A SHORTWAVE
DISTURBANCE APPROACHING FROM THE SOUTHWEST WILL ALLOW FOR A FEW
LIGHT SHOWERS ACROSS THE AREA WITH SOME VIRGA DUE TO VERY DRY AIR
AT LOW LEVELS. CIGS WILL BEGIN TO FALL OVERNIGHT WITH LIGHT RAIN
MOVING IN AS THE MAIN UPPER LEVEL SYSTEM BEGINS TO APPROACH. MODEL
SOUNDINGS SUPPORT A POTENTIAL RA/PL MIX FOR CLL EARLY MONDAY
MORNING BUT FEEL THIS IS OVERDONE AND PRECIP SHOULD REMAIN AS
RAIN. CHANCES FOR WINTRY MIX AT CLL/UTS LOOK BETTER FOR TUESDAY.
38
PREV DISCUSSION... /ISSUED 454 AM CST SUN NOV 24 2013/
DISCUSSION...
COLDER AIRMASS CONTINUES TO DEEPEN OVER SE TX FROM NE TO SW.
AIRMASS IS BECOMING DRIER AND PERHAPS DRIER THAN PREVIOUSLY
FORECASTED BY SHORT RANGE MODELS. MIDNIGHT SFC ANALYSIS HAS 1042MB
SFC HIGH OVER THE C PLAINS HEADED INTO THE MIDWEST. DUE TO THE
DRIER BOUNDARY LAYER...NOT EXPECTING MUCH IN THE WAY OF PRECIP
TODAY WITH LOW/MID LEVEL CLOUD DECK. COLD ADVECTION AND CLOUD
COVER WILL KEEP MAX TEMPS IN THE 40S TODAY.
UPPER AIR ANALYSIS AND WATER VAPOR IMAGERY SHOW CLOSED UPPER LOW
OVER THE DESERT SW. SEEMS THE LOW HAS WEAKEN A TOUCH WITH 500MB
HEIGHTS A BIT HIGHER THAN 24 HRS AGO. THAT SAID...LEAD JET STREAK
AND SHORT WAVE ARE CAUSING FROZEN PRECIP OVER W TX INTO C TX THIS
MORNING. THIS LEAD SHORT WAVE DOES NOT SEEM QUITE AS STRONG AS
PREVIOUS MODEL RUNS HAD INDICATED. SEEMS THAT PRECIP OVERNIGHT MAY
NOT QUITE AS GREAT AND LARGE SCALE LIFT IS NOT AS STRONG. AS SUCH
IT WILL TAKE LONGER FOR THE BOUNDARY LAYER TO MOISTEN THROUGH WET
BULB THERMODYNAMICS. DO NOT THINK THE THREAT FOR RAIN/SLEET OR
FREEZING RAIN MIX WILL BE THAT HIGH MONDAY MORNING. MODEL
SOUNDINGS FROM NAM/GFS STILL SUPPORT MIXED PRECIP TYPE FROM
COLLEGE STATION TO CROCKETT BUT THAT MAY BE A BIT MORE OF A
STRETCH. LIKELY HAVE ALL RAIN IN THESE AREAS. MIN TEMPS WILL BE
TRICKY AS WELL. WILL STICK CLOSER TO COLDER GFS MOS NUMBERS IN
FORECAST BUT MAY NEED SOME THERMODYNAMICS TO HELP GET THAT COLD
AT THE SURFACE. IF THAT HAPPENS WHILE NO ACCUMULATION IS
EXPECTED...IMPACTS WILL BE FOR ELEVATED BRIDGES/OVERPASSES WITH A
LIGHT GLAZE IF ANYTHING.
ON MONDAY MAIN UPPER LEVEL JET AND UPPER LEVEL LOW BEGIN TO MOVE
INTO THE AREA. LARGE SCALE ASCENT WILL ONLY INCREASE WITH LARGE
OMEGA AND QUITE A BIT OF Q-VECTOR CONVERGENCE SPREADING OVER THE
AREA. ISENTROPIC LIFT OVER STALLED FRONT IN THE GULF WILL ONLY
INCREASE DUE TO THE STRONG FORCING. NAM/ECMWF STILL KEEP COASTAL
LOW CLOSER TO THE COAST THAN THE GFS. NOTICED SEVERAL ENHANCED
RAIN BANDS THAT SET UP OVER THE AREA. CROSS-SECTIONS DO SHOW SOME
FRONTOGENETIC FORCING CO-LOCATED WITH AREAS OF POSSIBLE CSI. HI-
RES WRF-ARW SHOWS SOME VERY SIMILAR BANDED FEATURES AND WOULD NOT
BE SURPRISED IF THERE WERE SOME AREAS OF ENHANCED PRECIP DUE TO
BANDING. FORECAST WILL STICK WITH 80/90 POPS ON MONDAY. PRECIP
TOTALS AGAIN LOOK TO BE IN THE 1-2 INCH RANGE FOR MONDAY. FEEL
MOST AREAS SHOULD BE ABLE TO HANDLE THIS MUCH PRECIP ESPECIALLY
OVER 6-12 HRS. THE COASTAL LOW WILL ALSO SUPPORT EASTERLY WINDS TO
THE NORTH OF IT WHICH COULD INCREASE TIDE LEVELS. WILL AGAIN NEED
TO MONITOR FOR THE POSSIBILITY OF COASTAL FLOODING MON/TUE.
FORECASTING WINTER PRECIP FOR THE AREA ON TUESDAY IS NOT VERY
STRAIGHT FORWARD. ALL OF THE MODELS STILL HAVE THE UPPER LOW
TRACKING DIRECTLY OVER THE AREA. IF ANYTHING MAYBE TRACK A BIT
FARTHER SOUTH AS A VORT MAX OVER MEXICO HELPS PULL THE LOW SOUTH
MONDAY NIGHT. THE UPPER LOW MAY NOW EVEN BE ABOUT 6 HRS SLOWER
TRACKING ACROSS THE AREA. DO THINK THAT UPWARD VERTICAL MOTION
WILL BE LARGE OVER THE AREA BUT NOT SURE IF THERE WILL BE ENOUGH
MOISTURE FOR THE SYSTEM TO WORK WITH AND IF TEMPS IN THE LOW
LEVELS WILL BE COLD ENOUGH FOR FROZEN PRECIP. RIGHT NOW THINK
NORTHERN AREAS COULD SEE A RAIN/SLEET MIX FROM BASICALLY COLLEGE
STATION TO HUNTSVILLE TO LIVINGSTON. NAM/GFS/ECMWF JUST DO NOT
SEEM TO COOL 925/850MB TEMPS ENOUGH TO STRICTLY SUPPORT FROZEN
PRECIP LIKE RAIN/SLEET/SNOW MIX. BY 18Z TUE TO 00Z WED THE
MID/UPPER LEVELS OF THE ATMOSPHERE DRY OUT ENOUGH SO THAT ONLY
PRECIP WILL BE RAIN THAT MAY HAPPEN TO FALL THROUGH A SUB-FREEZING
LAYER THICK ENOUGH TO FREEZE. WITH THAT SAID...DO NOT WANT TO
UNDER-ESTIMATE THE EFFECTS OF DYNAMICAL LIFT FROM THE UPPER LOW
AND ANY WET BULBING THAT MAY OCCUR UNDER THE LOW. MAY NEED TO
MONITOR FURTHER BUT COULD SEE THE FROZEN PRECIP LINE DROP FARTHER
SOUTH ESPECIALLY IF THERE IS MORE MOISTURE TO WORK WITH AND IT
LOOKS LIKE TEMPS MAY BE COLD ENOUGH. OVERALL THINK ANY FROZEN
PRECIP WILL BE LIGHT AND SHOULD NOT ACCUMULATE. MAIN ISSUES MAY
STILL BE ELEVATED SURFACES LIKE OVERPASSES.
ATMOSPHERE REALLY DRIES OUT 00Z-12Z WED WITH NEXT FRONT PUSHING
THROUGH. HIGH PRESSURE THEN BUILDS INTO THE OZARKS WED NIGHT INTO
THUR. SHOULD HAVE CLEAR SKIES AND MUCH CALMER WINDS. LOOKS LIKE
THANKSGIVING DAY COULD START OUT WITH AN AREA WIDE FREEZE. EVEN
FRIDAY MORNING MAY HAVE SOME SPOTS WITH FREEZING TEMPS. BELOW
NORMAL TEMPS SHOULD CONTINUE INTO THE WEEKEND WITH RETURN FLOW
FINALLY SETTING UP NEXT SATURDAY INTO SUNDAY.
39
MARINE...
STRONG NORTHEAST WINDS CONTINUE THIS MORNING ACROSS THE COASTAL
WATERS THIS MORNING AND ADVISORIES WILL CONTINUE FOR ALL WATERS
THROUGH MID MORNING. WINDS ALONG THE IMMEDIATE COAST WILL BEGIN TO
WEAKEN AND THE BAYS ARE EXPECTED TO FALL BELOW ADVISORY CRITERIA.
WINDS ACROSS THE COASTAL WATERS WILL REMAIN ABOVE ADVISORY
CRITERIA THROUGH THE DAY TODAY AND ADVISORIES WILL LIKELY NEED TO
BE CARRIED EVEN LONGER...PARTICULARLY FOR THE OFFSHORE WATERS
WHERE ADVISORY CONDITIONS ARE EXPECTED THROUGH MID WEEK. FORECAST
MODELS CONTINUE TO BRING THE UPPER LEVEL LOW FURTHER SOUTH WHICH
WILL SHIFT THE COASTAL LOW SOUTH OF OUR MARINE ZONES AND ALLOW FOR
NORTHEAST WINDS THROUGH TUESDAY WHICH WILL BECOME NORTHWESTERLY AS
THE UPPER LOW MOVES OFF TO OUR EAST. 38
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 32 38 34 45 / 40 60 90 60 30
HOUSTON (IAH) 47 36 42 36 45 / 20 40 90 70 50
GALVESTON (GLS) 52 43 48 41 48 / 20 40 80 80 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION THROUGH MONDAY AFTERNOON FOR
THE FOLLOWING ZONES: MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: GALVESTON BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM 6 PM CST THIS EVENING
THROUGH MONDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST MONDAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
1049 PM EST MON NOV 25 2013
.SYNOPSIS...
STORM SYSTEM WILL MOVE FROM THE GULF COAST TONIGHT INTO EASTERN
NC/VA BY WEDNESDAY MORNING...AND FINALLY NORTH INTO QUEBEC BY WED
NIGHT. THIS SYSTEM WILL BRING A POTPOURRI OF WEATHER THROUGH WED
NIGHT. HIGH PRESSURE ENTERS FROM THE SOUTHWEST BY THURSDAY...AND
STICKS AROUND INTO SATURDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1045 PM EST MONDAY...
QUICK UPDATE TO START THE ADVISORY RIGHT NOW OVER THE WEST SINCE
GETTING REPORTS OF SNOW ACCUMULATING ON ROADS ACROSS THE FAR SW.
LEAVING THE REMAINDER FROM ALONG THE BLUE RIDGE EAST STARTING AT 2
AM.
AS OF 825 PM EST MONDAY...
MID/LOW LEVEL DRY AIR PER EVENING SOUNDINGS AND LATEST OBS HAS
CONTINUED TO KEEP PRECIP FARTHER TO THE WEST THIS EVENING WITH
MOST PRECIP ON RADAR ALOFT AND JUST GOING TO SLOWLY MOISTEN THE
COLUMN ATTM. IN ADDITION THE LOW LEVEL FLOW REMAINS RATHER WEAK
AND SW JUST ABOVE THE SURFACE MAKING FOR LIMITED ISENTROPIC LIFT
AS THE BEST JET SUPPORT INCLUDING AXIS OF HIGHER DEWPOINTS LINGERS
ACROSS THE TN VALLEY. BOTH THE LATEST RAP AND HRRR HAVE DELAYED
THE ONSET OF SIGNIFICANT PRECIP UNTIL AFTER MIDNIGHT FOR THE MOST
PART WEST AND UNTIL THE EARLY MORNING HOURS OUT EAST. SINCE THIS
LOOKS IN LINE WITH THE LATEST TRENDS...HAVE DELAYED ONSET OF POPS
ACROSS THE REGION FOR COUPLE HOURS BEFORE THINGS REALLY MOISTEN
AND PRECIP QUICKLY INCREASES ESPCLY BLUE RIDGE AND ACROSS THE
SOUTH AFTER MIDNIGHT. EVENING RAOBS AND SURFACE OBS INDICATE STILL
LOTS OF ROOM FOR WET BULB COOLING ALTHOUGH TREND OUT WEST HAS BEEN
FOR DEWPOINTS TO RISE WITHOUT MUCH COOLING AS PRECIP EVAPORATES
BEFORE REACHING THE SURFACE. THIS SUPPORTS KEEPING A MIXED BAG BUT
A LITTLE MORE SNOW WEST AT THE ONSET WITH SOME CHANCE OF
SNOW/SLEET EAST THEN MOSTLY FZRA/SLEET. ADJUSTED TEMPS DOWN SOME
FOR CURRENT READINGS WITH MOST LIKELY NOT DROPPING TOO MUCH MORE
UNTIL HEAVIER PRECIP ARRIVES.
MAIN ADJUST TO HEADLINES WAS TO EXTEND THE GOING ADVISORY LONGER
INTO THE AFTERNOON ON TUESDAY FOR AMHERST/BOTETOURT COUNTIES
GIVEN FORECAST SOUNDINGS SHOWING TEMPS UNABLE TO GET MUCH ABOVE
FREEZING UNTIL LATE IN THE DAY. THIS MAY ALSO BE THE CASE ON THE
NORTH SIDE OF HIGHWAY 460 IN ROANOKE AND MONTGOMERY COUNTIES BUT
HELD THOSE AREAS AT A NOON EXPIRATION FOR NOW GIVEN POTENTIAL FOR
THAT AREA TO SEE WARMING FROM HEAVIER RAINFALL THROUGH THE WARM
LAYER SOONER.
PREVIOUS DISCUSSION AS OF 250 PM EST MONDAY...
DURING THIS TIME PERIOD WILL BE DEALING WITH NUISANCE WINTER WX
WHERE PRECIP ARRIVES INTO THE NC MTNS/FAR SW VA BEFORE MIDNIGHT
OVERSPREADING THE REGION BY DAWN. SUNSHINE CAME OUT TODAY OVER MOST
OF THE AREA ALLOWING TEMPS TO CLIMB ABOVE FREEZING AND AROUND 40 IN
SOUTHSIDE VA/FAR SW VA. DEWPOINTS HOWEVER ARE TANKED IN THE SINGLE
DIGITS. HENCE LIES THE PROBLEM TONIGHT. UPSTREAM CLOUDS ALREADY
POURING BACK IN AND THIS MAY HELP IN TERMS OF NOT ALLOWING TEMPS TO
DROP TOO FAR AFTER SUNSET AS CLOUDS ACT AS A BLANKET. THEN...AS THE
PRECIP ARRIVES...GIVEN THE DRY AIR IT MAY TAKE AN HOUR OR TWO TO
SATURATE THE LOW LVLS BUT ONCE IT DOES...THE TEMP/DEWPOINT PROFILE
WILL HEAD TOWARD CRITICAL LEVELS FOR WINTER PRECIP. AT THE ONSET THE
TEMPS SHOULD BE COLD ENOUGH FOR SLEET OR SNOW THEN CHANGE QUICKLY TO
FREEZING RAIN AS STRONG SOUTH TO SOUTHWEST FLOW BRINGS A WARM NOSE
INTO THE MTNS AFTER MIDNIGHT AND REACHING OUR NRN CWA BY MID
MORNING. WITH INSITU WEDGE AND SFC WET BULBING TO AT OR BELOW ZERO
WITH WARM NOSE...FREEZING RAIN WILL BECOME AN ISSUE. GROUND HAS
TURNED COLDER AS EVIDENCE BY SOIL TEMPS IN THE LOWER TO MID 30S.
THERE WILL BE A LIGHT ACCUMULATION OF SLEET OR SNOW AT THE
ONSET...LESS THAN AN INCH...THEN QUICKLY CHANGING TO FZRA WITH
GLAZING EXPECTED ALONG TREE/POWERLINES AND METAL OBJECTS FIRST THEN
BRIDGES/OVERPASSES. BASED ON RAINFALL RATE AND WARM AIR ALOFT THE
ACCRETION OF ICE WILL BE IN A 2-4 HOUR WINDOW AS THE BETTER LIFT
TAKES PLACE AFTER 12Z...ALLOWING THE RATES TO INCREASE AND DRAG DOWN
WARMER AIR. MODERATE TO HEAVIER RAINFALL USUALLY DOES NOT STICK TO
ROADS VERY WELL WHEN SFC TEMPS ARE EXPECTED TO BE NEAR FREEZING.
NEED MORE LIKE MID TO UPPER 20S OR LOWER.
STILL THERE SEEMS TO BE ENOUGH EVIDENCE THAT MOST OF OUR CWA WILL
GET AT LEAST A TRACE OF ICE WITH HIGHER AMOUNTS ALONG THE BLUE RIDGE
FROM BOONE/BLOWING ROCK NORTH TO BUENA VISTA/AMHERST. ALSO THE
ALLEGHANY HIGHLAND SHOULD SEE UP TO 2/10S. IT ONLY TAKES A TRACE OF
ICE TO CAUSE TRAVEL PROBLEMS. BASED ON THIS AND COLLABORATION WITH
SURROUNDING NWS OFFICES...WE HAVE A WINTER WX ADVISORY OUT FOR THE
ENTIRE CWA FOR TONIGHT-MIDDAY/AFTERNOON TUESDAY...ENDING EARLIER
IN THE SOUTH.
TEMPS THIS EVENING WILL START FALLING SLOWLY THEN DROP A LITTLE MORE
ONCE PRECIP ARRIVES ALOFT LEADING TO EVAP COOLING. LOOKING AT LOWS
FROM THE UPPER 20S TO AROUND 30...THEN WARMING GRADUALLY TO ABOVE
FREEZING DURING THE DAY TUESDAY...FIRST IN THE FAR SW VA/SRN WV AREA
OUTSIDE THE WEDGE AND INTO WRN NC MTNS ALONG THE TN BORDER...THEN
SOUTHSIDE VA/NW NC PIEDMONT EXPANDING NORTHWARD BY AFTERNOON TO THE
NRN BLUE RIDGE. COULD BE A DEAL WHERE SOME VALLEYS ACROSS
BATH/ROCKBRIDGE/AMHERST TAKE INTO TUE EVENING...BUT THINK THE WARMER
RAIN AND HIGHER RATES TO BRING IT UP. FOR MOST OF US...THE ICE WILL
BE MELTED AND GONE BY MIDDAY/EARLY AFTERNOON WITH HIGHS EXPECTED TO
BE IN THE MID TO UPPER 30S SOUTH...TO LOWER 30S NORTH. BUT WILL BE
DEALING WITH MODERATE TO HEAVY AT TIMES COLD NOVEMBER RAINS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 340 PM EST MONDAY...
GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE NORTHERN AND SOUTHERN
BEGINNING TO PHASE TUESDAY NIGHT AND BECOME ONE SYSTEM WEDNESDAY.
THE UPPER LEVEL LOW TRACKING ALONG THE GULF COAST WILL OPEN OVER THE
TENNESSEE VALLEY AND MERGE WITH THE NORTHERN STREAM TROUGH ENTERING
THE OHIO VALLEY BY WEDNESDAY MORNING. THE SURFACE LOW PRESSURE OVER
GEORGIA ON TUESDAY EVENING WILL TRACK NORTHEAST ALONG THE LEE SIDE
OF THE APPALACHIAN MOUNTAINS EARLY WEDNESDAY MORNING. AS THE
NORTHERN STREAM TROUGH BECOMES DOMINATE...A SECONDARY SURFACE LOW IS
EXPECTED TO DEVELOP OVER THE VIRGINIA PIEDMONT TUESDAY NIGHT...THEN
LIFT TO NEW ENGLAND ON WEDNESDAY. BY WEDNESDAY EVENING...THE SFC LOW
WILL BE LOCATED OVER MAINE WITH TRAILING COLD FRONT PUSHING INTO THE
ATLANTIC OCEAN. HIGH PRESSURE WILL BE BUILDING ACROSS OUR REGION
WEDNESDAY NIGHT INTO THURSDAY.
THE RAIN MAY BE HEAVY AT TIMES TUESDAY AFTERNOON INTO WEDNESDAY
MORNING. JET DYNAMICS AND LIFT ASSOCIATED WITH PASSING SURFACE AND
SHORTWAVES WILL BRING HIGH RAINFALL RATES TO THE AREA. COLDER AIR
WILL PUSH INTO OUR REGION TUESDAY NIGHT INTO WEDNESDAY MORNING. RAIN
WILL TRANSITION TO SNOW STARTING ALONG THE HIGHER ELEVATION THEN
ACROSS THE REST ON WEDNESDAY. MOISTURE WILL PULL OUT OF MOST OF THE
AREA WEDNESDAY EVENING INTO WEDNESDAY NIGHT. NORTHWEST UPSLOPE SNOW
SHOWERS AND SNOW FLURRIES WILL CONTINUE INTO WEDNESDAY NIGHT INTO
THURSDAY. POTENTIAL STORM TOTAL SNOW FOR THE MOUNTAINS WILL LIKELY
RANGE FROM 1-4 INCHES TUESDAY NIGHT INTO WEDNESDAY...WITH UPWARDS OF
4 TO 6 INCHES ON WESTERN SLOPES TUESDAY NIGHT INTO WEDNESDAY NIGHT.
LIGHTER AMOUNTS OF SNOW EXPECTED GENERALLY LESS THAN INCH IN THE
EAST. INCREASING WINDS WILL ACCOMPANY THE UPSLOPE SNOW SHOWERS.
STRONG PRESSURE RISES AND COLD AIR ADVECTION ALONG WITH A 45-55KT
CROSS BARRIER JET WILL BRING SUSTAIN WINDS OF 20-30 MPH GUSTING TO
AROUND 50 MPH FOR COUNTIES ALONG THE BLUE RIDGE...PARTICULARLY THE
NORTH CAROLINA HIGH COUNTY AND GRAYSON HIGHLANDS. WIND SPEED WILL BE
CLOSE TO ADVISORY LEVELS. WILL HOLD OFF ON ISSUING HEADLINES FOR
SNOW AND WINDS FOR NOW TO AVOID CONFUSION WITH ONGOING EVENT. ONE
SET OF HEADLINES WILL BE REPLACED BY ANOTHER SET EVERY 6-12 HOURS.
PLAN TO HIGHLIGHT THE POTENTIAL IN HWO. AS THIS SYSTEM DEVELOPS AND
MATURES OVER THE REGION...EVERYONE SHOULD BE PREPARED FOR RAPIDLY
CHANGING CONDITIONS...ESPECIALLY IF YOU ARE TRAVELING ALONG THE EAST
COAST THIS WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 1245 PM EDT MONDAY...
LARGE SCALE PATTERN TRANSITIONS TO ZONAL FLOW WITH SURFACE HIGH
PRESSURE IN CONTROL THROUGH THE WEEKEND. THIS RESULTS IN SLOWLY
MODERATING TEMPERATURES...YET SHOULD REMAIN BELOW SEASONABLE
AVERAGES EVEN BY SUNDAY. ALSO THINKING HIGHER CLOUDS WILL BECOME
MORE PREVALENT BY SUNDAY WHICH WOULD KEEP HIGHS DOWN SOMEWHAT. LONG
TERM MODELS GENERALLY IN AGREEMENT THAT NEXT WEATHER SYSTEM WILL
MATERIALIZE IN THE SOUTHERN PLAINS LATE SUNDAY AND THEN QUICKLY
APPROACHING THE SOUTHERN APPALACHIANS FROM THE SOUTHWEST ON MONDAY.
RIGHT NOW THE 00Z ECWMF IS A LITTLE FASTER THAN THE 12Z GFS AND
GIVEN THE GENERALLY ZONAL FLOW PATTERN THIS FASTER IDEA IS
FAVORED...ESPECIALLY AS A STRONGER SYSTEM DIGS INTO THE WESTERN U.S.
AND EJECTS THIS WAVE OUT ACROSS THE PLAINS AND TOWARDS THE
APPALACHIANS. THE HIGH PRESSURE WILL BE WEAKENING AND RETREATING AS
THIS SYSTEM APPROACHES BY EARLY MONDAY BUT AIRMASS APPEARS THAT IT
WILL MODERATE ENOUGH SO THAT PRECIP TYPE REMAINS JUST RAIN. HOWEVER
IT WILL BE WORTH KEEPING AN EYE ON THE TIMING OF PRECIP ARRIVAL AND
STRENGTH OF LINGERING HIGH...AS WELL AS HOW LOW INITIAL WET BULB
TEMPERATURES ARE WHEN PRECIP ARRIVES. CANT RULE OUT SOME POCKETS OF
FREEZING RAIN IF THIS COMES IN OVERNIGHT...BUT AT THIS POINT STILL A
LONG WAY OFF.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
AS OF 545 PM EST MONDAY...
VFR CONDITIONS THIS EVENING TO LOWER TO MVFR/IFR TONIGHT AS
MIXED PRECIP MOVES IN FROM THE SW. THUS LOOKING AT DETERIORATING
FLYING WEATHER LATER THIS EVENING WITH WIDESPREAD LOW CIGS AND AT
LEAST MVFR VSBYS OVER THE WEST BY DAYBREAK TUESDAY. SOME
SNOW/SLEET POSSIBLE AT THE ONSET AT BLF/ROA/BCB/LWB SHOULD CHANGE
QUICKLY TO FZRA...WHILE LYH STARTS AS FZRA WITH PERHAPS A BIT OF
PL. DAN WILL BE BORDERLINE ON FZRA BUT TEMPS SHOULD BE HUGGING
32-33F AT THE SFC SO INCLUDED A HOUR OR TWO OF -FZRA THERE EARLY
TUESDAY. WARM NOSE ALOFT TO CHANGE FZRA TO RAIN AT ALL SITES
TUESDAY AFTERNOON ALTHOUGH SPOTS LIKE KLWB/KLYH MAY KEEP -FZRA
INTO MID OR LATE AFTERNOON. RAIN BECOMES HEAVY AT TIMES TUESDAY
AFTERNOON ESPECIALLY AT BCB/ROA/LYH/DAN. WILL EXPECT TO SEE
FLUCTUATIONS IN CIGS/VSBYS BASED ON RAINFALL RATES BUT OVERALL
SHOULD BE IFR TO LIFR WITH MOUNTAIN OBSCURATIONS LIKELY. WITH THE
STRONG SE FLOW ABOVE THE SURFACE WILL ALSO BE SEEING LLWS
POTENTIAL AT ALL LOCATIONS THROUGH THE DAY TUESDAY AS LATEST
SOUNDINGS INDICATE 35-45 KTS JUST ABOVE THE SURFACE ESPCLY IN THE
AFTERNOON. THEREFORE INCLUDED LLWS AT MOST SPOTS FOR STRONG SOUTH
TO SE FLOW DEVELOPING RIGHT AFTER SUNRISE ON TUESDAY.
MODERATE TO HEAVY RAINFALL CONTINUES TUESDAY NIGHT WITH LOCATIONS
ACROSS SE WVA TRANSITIONING BACK TO SNOW BY EARLY WEDNESDAY. THIS
WILL KEEP LOW IFR/LIFR CIGS AND MVFR TO IFR VSBYS GOING TUESDAY
NIGHT AS THE CORE OF THE LOW PRESSURE SYSTEM TRACKS ACROSS THE
AREA.
RAIN CHANGES TO A SIGNIFICANT UPSLOPE EVENT BY WED WITH PERHAPS A
TRAILING DEFORMATION BAND OF SNOW WORKING EAST TOWARD THE BLUE
RIDGE WED MORNING. THIS MAY RESULT IN A FEW INCHES OF SNOW
ACCUMULATION AROUND KBLF/KLWB AND POSSIBLY A LIGHT AMOUNT EAST TO
KBCB. WIND WILL ALSO BECOME AN ISSUE ACROSS THE MOUNTAINS WITH NW
WIND GUSTS TO 45 KTS OR MORE WED WITH A SIGNIFICANT COASTAL LOW
MOVING ACROSS COASTAL NEW ENGLAND.
RAPID IMPROVEMENT WILL OCCUR ON THURSDAY AS THE STORM SYSTEM
PULLS AWAY AND DRIER AIR WORKS IN...RESULTING IN WIDESPREAD VFR
CONDITIONS. VFR THEN CONTINUES UNDER HIGH PRESSURE FOR FRIDAY
THROUGH SATURDAY.
&&
.HYDROLOGY...
AS OF NOON EST MONDAY...
MODEL CONSENSUS AND HPC GUIDANCE GENERALLY IN THE 2 TO 3 INCH RANGE
OF LIQUID QPF FOR THE IMPENDING STORM EVENT ALTHOUGH SOME SREF
ENSEMBLE MEMBERS SHOWING OVER 4 INCHES BY ABOUT 12Z WEDNESDAY THE
27TH. QUESTION IS WHAT IMPACT THE RUNOFF FROM THIS WILL HAVE ON AREA
STREAMS AND RIVERS. POINT ONE IS THAT RIVERS ARE STARTING OFF AT
VERY LOW LEVELS ESPECIALLY ACROSS THE LOWER PORTIONS OF OUR RIVER
BASINS...ACROSS THE PIEDMONT. USGS DAILY STREAMFLOW PERCENTILES AS
OF THIS MORNING ARE SHOWING NEARLY ALL PIEDMONT RIVER AND STREAM
LOCATIONS RUNNING AT FLOWS BELOW THE 25TH PERCENTILE FOR THE DATE
AND SOME BELOW THE 10TH PERCENTILE. THIS ALSO HOLDS TRUE FOR MUCH OF
THE UPPER JAMES RIVER BASIN. 60-DAY RAINFALL DEFICITS HAVE BECOME
QUITE SIGNIFICANT...REACHING 4 TO 6 INCHES IN MANY OF THESE BASINS
OR AROUND 25 PERCENT OF NORMAL. DETERMINISTIC RIVER FORECASTS ISSUED
THIS MORNING BY THE FOUR RFCS SERVING THE BLACKSBURG HYDRO SERVICE
AREA INCLUDE 48 HOURS OF QPF THROUGH 12Z WEDNESDAY OF GENERALLY 2 TO
2.5 INCHES. AT OF THIS PACKAGE NO RIVERS ARE FORECAST TO REACH FLOOD
STAGE OR EVEN ACTION STAGE (GENERALLY A FEW FEET BELOW FLOOD STAGE)
ALTHOUGH SEVERAL COME CLOSE...INCLUDING THE NORTH FORK HOLSTON RIVER
AT SALTVILLE AND GREENBRIER RIVER AT ALDERSON. THAT SAID HYDROLOGIC
MODELS TEND TO HAVE SOME DIFFICULTY AFTER EXTENDED DRY PERIODS IN
HANDLING RUNOFF WHICH IS GENERALLY MUCH MORE EFFICIENT IN THE COOL
SEASON. HENCE...THE RESPONSE ON RIVERS REMAINS SOMEWHAT UNCERTAIN
BUT NOT ENOUGH CONFIDENCE TO ISSUE A FLOOD WATCH. NOT EXPECTING MUCH
IF ANY CONVECTION WITH THIS STORM SO RAINFALL RATES SHOULD REMAIN
MODEST..IN THE 0.10 TO 0.25 INCH PER HOUR RANGE. BUT HIGHER RAINFALL
RATES IN ANY ELEVATED STORMS THAT ARE ABLE TO DEVELOP COULD LEAD TO
LOCALIZED RUNOFF PROBLEMS. THESE COULD BE HANDLED WITH SHORT-FUSE
HYDROLOGIC PRODUCTS..FLOOD ADVISORIES OR EVEN FLASH FLOOD WARNINGS
BUT THE LIKELIHOOD AT THIS POINT IS QUITE LOW FOR THIS TO OCCUR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM EST TUESDAY FOR
VAZ018>020-023-024-035.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ007-
009>017.
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR
VAZ022-032>034-043>047-058-059.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR NCZ001-002-
018.
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR
NCZ003>006-019-020.
WV...WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM EST TUESDAY FOR
WVZ045.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR WVZ042>044.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...JH/WP
SHORT TERM...KK
LONG TERM...SK
AVIATION...JH/RAB/WP
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
905 PM EST MON NOV 25 2013
.SYNOPSIS...
STORM SYSTEM WILL MOVE FROM THE GULF COAST TONIGHT INTO EASTERN
NC/VA BY WEDNESDAY MORNING...AND FINALLY NORTH INTO QUEBEC BY WED
NIGHT. THIS SYSTEM WILL BRING A POTPOURRI OF WEATHER THROUGH WED
NIGHT. HIGH PRESSURE ENTERS FROM THE SOUTHWEST BY THURSDAY...AND
STICKS AROUND INTO SATURDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 825 PM EST MONDAY...
MID/LOW LEVEL DRY AIR PER EVENING SOUNDINGS AND LATEST OBS HAS
CONTINUED TO KEEP PRECIP FARTHER TO THE WEST THIS EVENING WITH
MOST PRECIP ON RADAR ALOFT AND JUST GOING TO SLOWLY MOISTEN THE
COLUMN ATTM. IN ADDITION THE LOW LEVEL FLOW REMAINS RATHER WEAK
AND SW JUST ABOVE THE SURFACE MAKING FOR LIMITED ISENTROPIC LIFT
AS THE BEST JET SUPPORT INCLUDING AXIS OF HIGHER DEWPOINTS LINGERS
ACROSS THE TN VALLEY. BOTH THE LATEST RAP AND HRRR HAVE DELAYED
THE ONSET OF SIGNIFICANT PRECIP UNTIL AFTER MIDNIGHT FOR THE MOST
PART WEST AND UNTIL THE EARLY MORNING HOURS OUT EAST. SINCE THIS
LOOKS IN LINE WITH THE LATEST TRENDS...HAVE DELAYED ONSET OF POPS
ACROSS THE REGION FOR COUPLE HOURS BEFORE THINGS REALLY MOISTEN
AND PRECIP QUICKLY INCREASES ESPCLY BLUE RIDGE AND ACROSS THE
SOUTH AFTER MIDNIGHT. EVENING RAOBS AND SURFACE OBS INDICATE STILL
LOTS OF ROOM FOR WET BULB COOLING ALTHOUGH TREND OUT WEST HAS BEEN
FOR DEWPOINTS TO RISE WITHOUT MUCH COOLING AS PRECIP EVAPORATES
BEFORE REACHING THE SURFACE. THIS SUPPORTS KEEPING A MIXED BAG BUT
A LITTLE MORE SNOW WEST AT THE ONSET WITH SOME CHANCE OF
SNOW/SLEET EAST THEN MOSTLY FZRA/SLEET. ADJUSTED TEMPS DOWN SOME
FOR CURRENT READINGS WITH MOST LIKELY NOT DROPPING TOO MUCH MORE
UNTIL HEAVIER PRECIP ARRIVES.
MAIN ADJUST TO HEADLINES WAS TO EXTEND THE GOING ADVISORY LONGER
INTO THE AFTERNOON ON TUESDAY FOR AMHERST/BOTETOURT COUNTIES
GIVEN FORECAST SOUNDINGS SHOWING TEMPS UNABLE TO GET MUCH ABOVE
FREEZING UNTIL LATE IN THE DAY. THIS MAY ALSO BE THE CASE ON THE
NORTH SIDE OF HIGHWAY 460 IN ROANOKE AND MONTGOMERY COUNTIES BUT
HELD THOSE AREAS AT A NOON EXPIRATION FOR NOW GIVEN POTENTIAL FOR
THAT AREA TO SEE WARMING FROM HEAVIER RAINFALL THROUGH THE WARM
LAYER SOONER.
PREVIOUS DISCUSSION AS OF 250 PM EST MONDAY...
DURING THIS TIME PERIOD WILL BE DEALING WITH NUISANCE WINTER WX
WHERE PRECIP ARRIVES INTO THE NC MTNS/FAR SW VA BEFORE MIDNIGHT
OVERSPREADING THE REGION BY DAWN. SUNSHINE CAME OUT TODAY OVER MOST
OF THE AREA ALLOWING TEMPS TO CLIMB ABOVE FREEZING AND AROUND 40 IN
SOUTHSIDE VA/FAR SW VA. DEWPOINTS HOWEVER ARE TANKED IN THE SINGLE
DIGITS. HENCE LIES THE PROBLEM TONIGHT. UPSTREAM CLOUDS ALREADY
POURING BACK IN AND THIS MAY HELP IN TERMS OF NOT ALLOWING TEMPS TO
DROP TOO FAR AFTER SUNSET AS CLOUDS ACT AS A BLANKET. THEN...AS THE
PRECIP ARRIVES...GIVEN THE DRY AIR IT MAY TAKE AN HOUR OR TWO TO
SATURATE THE LOW LVLS BUT ONCE IT DOES...THE TEMP/DEWPOINT PROFILE
WILL HEAD TOWARD CRITICAL LEVELS FOR WINTER PRECIP. AT THE ONSET THE
TEMPS SHOULD BE COLD ENOUGH FOR SLEET OR SNOW THEN CHANGE QUICKLY TO
FREEZING RAIN AS STRONG SOUTH TO SOUTHWEST FLOW BRINGS A WARM NOSE
INTO THE MTNS AFTER MIDNIGHT AND REACHING OUR NRN CWA BY MID
MORNING. WITH INSITU WEDGE AND SFC WET BULBING TO AT OR BELOW ZERO
WITH WARM NOSE...FREEZING RAIN WILL BECOME AN ISSUE. GROUND HAS
TURNED COLDER AS EVIDENCE BY SOIL TEMPS IN THE LOWER TO MID 30S.
THERE WILL BE A LIGHT ACCUMULATION OF SLEET OR SNOW AT THE
ONSET...LESS THAN AN INCH...THEN QUICKLY CHANGING TO FZRA WITH
GLAZING EXPECTED ALONG TREE/POWERLINES AND METAL OBJECTS FIRST THEN
BRIDGES/OVERPASSES. BASED ON RAINFALL RATE AND WARM AIR ALOFT THE
ACCRETION OF ICE WILL BE IN A 2-4 HOUR WINDOW AS THE BETTER LIFT
TAKES PLACE AFTER 12Z...ALLOWING THE RATES TO INCREASE AND DRAG DOWN
WARMER AIR. MODERATE TO HEAVIER RAINFALL USUALLY DOES NOT STICK TO
ROADS VERY WELL WHEN SFC TEMPS ARE EXPECTED TO BE NEAR FREEZING.
NEED MORE LIKE MID TO UPPER 20S OR LOWER.
STILL THERE SEEMS TO BE ENOUGH EVIDENCE THAT MOST OF OUR CWA WILL
GET AT LEAST A TRACE OF ICE WITH HIGHER AMOUNTS ALONG THE BLUE RIDGE
FROM BOONE/BLOWING ROCK NORTH TO BUENA VISTA/AMHERST. ALSO THE
ALLEGHANY HIGHLAND SHOULD SEE UP TO 2/10S. IT ONLY TAKES A TRACE OF
ICE TO CAUSE TRAVEL PROBLEMS. BASED ON THIS AND COLLABORATION WITH
SURROUNDING NWS OFFICES...WE HAVE A WINTER WX ADVISORY OUT FOR THE
ENTIRE CWA FOR TONIGHT-MIDDAY/AFTERNOON TUESDAY...ENDING EARLIER
IN THE SOUTH.
TEMPS THIS EVENING WILL START FALLING SLOWLY THEN DROP A LITTLE MORE
ONCE PRECIP ARRIVES ALOFT LEADING TO EVAP COOLING. LOOKING AT LOWS
FROM THE UPPER 20S TO AROUND 30...THEN WARMING GRADUALLY TO ABOVE
FREEZING DURING THE DAY TUESDAY...FIRST IN THE FAR SW VA/SRN WV AREA
OUTSIDE THE WEDGE AND INTO WRN NC MTNS ALONG THE TN BORDER...THEN
SOUTHSIDE VA/NW NC PIEDMONT EXPANDING NORTHWARD BY AFTERNOON TO THE
NRN BLUE RIDGE. COULD BE A DEAL WHERE SOME VALLEYS ACROSS
BATH/ROCKBRIDGE/AMHERST TAKE INTO TUE EVENING...BUT THINK THE WARMER
RAIN AND HIGHER RATES TO BRING IT UP. FOR MOST OF US...THE ICE WILL
BE MELTED AND GONE BY MIDDAY/EARLY AFTERNOON WITH HIGHS EXPECTED TO
BE IN THE MID TO UPPER 30S SOUTH...TO LOWER 30S NORTH. BUT WILL BE
DEALING WITH MODERATE TO HEAVY AT TIMES COLD NOVEMBER RAINS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 340 PM EST MONDAY...
GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE NORTHERN AND SOUTHERN
BEGINNING TO PHASE TUESDAY NIGHT AND BECOME ONE SYSTEM WEDNESDAY.
THE UPPER LEVEL LOW TRACKING ALONG THE GULF COAST WILL OPEN OVER THE
TENNESSEE VALLEY AND MERGE WITH THE NORTHERN STREAM TROUGH ENTERING
THE OHIO VALLEY BY WEDNESDAY MORNING. THE SURFACE LOW PRESSURE OVER
GEORGIA ON TUESDAY EVENING WILL TRACK NORTHEAST ALONG THE LEE SIDE
OF THE APPALACHIAN MOUNTAINS EARLY WEDNESDAY MORNING. AS THE
NORTHERN STREAM TROUGH BECOMES DOMINATE...A SECONDARY SURFACE LOW IS
EXPECTED TO DEVELOP OVER THE VIRGINIA PIEDMONT TUESDAY NIGHT...THEN
LIFT TO NEW ENGLAND ON WEDNESDAY. BY WEDNESDAY EVENING...THE SFC LOW
WILL BE LOCATED OVER MAINE WITH TRAILING COLD FRONT PUSHING INTO THE
ATLANTIC OCEAN. HIGH PRESSURE WILL BE BUILDING ACROSS OUR REGION
WEDNESDAY NIGHT INTO THURSDAY.
THE RAIN MAY BE HEAVY AT TIMES TUESDAY AFTERNOON INTO WEDNESDAY
MORNING. JET DYNAMICS AND LIFT ASSOCIATED WITH PASSING SURFACE AND
SHORTWAVES WILL BRING HIGH RAINFALL RATES TO THE AREA. COLDER AIR
WILL PUSH INTO OUR REGION TUESDAY NIGHT INTO WEDNESDAY MORNING. RAIN
WILL TRANSITION TO SNOW STARTING ALONG THE HIGHER ELEVATION THEN
ACROSS THE REST ON WEDNESDAY. MOISTURE WILL PULL OUT OF MOST OF THE
AREA WEDNESDAY EVENING INTO WEDNESDAY NIGHT. NORTHWEST UPSLOPE SNOW
SHOWERS AND SNOW FLURRIES WILL CONTINUE INTO WEDNESDAY NIGHT INTO
THURSDAY. POTENTIAL STORM TOTAL SNOW FOR THE MOUNTAINS WILL LIKELY
RANGE FROM 1-4 INCHES TUESDAY NIGHT INTO WEDNESDAY...WITH UPWARDS OF
4 TO 6 INCHES ON WESTERN SLOPES TUESDAY NIGHT INTO WEDNESDAY NIGHT.
LIGHTER AMOUNTS OF SNOW EXPECTED GENERALLY LESS THAN INCH IN THE
EAST. INCREASING WINDS WILL ACCOMPANY THE UPSLOPE SNOW SHOWERS.
STRONG PRESSURE RISES AND COLD AIR ADVECTION ALONG WITH A 45-55KT
CROSS BARRIER JET WILL BRING SUSTAIN WINDS OF 20-30 MPH GUSTING TO
AROUND 50 MPH FOR COUNTIES ALONG THE BLUE RIDGE...PARTICULARLY THE
NORTH CAROLINA HIGH COUNTY AND GRAYSON HIGHLANDS. WIND SPEED WILL BE
CLOSE TO ADVISORY LEVELS. WILL HOLD OFF ON ISSUING HEADLINES FOR
SNOW AND WINDS FOR NOW TO AVOID CONFUSION WITH ONGOING EVENT. ONE
SET OF HEADLINES WILL BE REPLACED BY ANOTHER SET EVERY 6-12 HOURS.
PLAN TO HIGHLIGHT THE POTENTIAL IN HWO. AS THIS SYSTEM DEVELOPS AND
MATURES OVER THE REGION...EVERYONE SHOULD BE PREPARED FOR RAPIDLY
CHANGING CONDITIONS...ESPECIALLY IF YOU ARE TRAVELING ALONG THE EAST
COAST THIS WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 1245 PM EDT MONDAY...
LARGE SCALE PATTERN TRANSITIONS TO ZONAL FLOW WITH SURFACE HIGH
PRESSURE IN CONTROL THROUGH THE WEEKEND. THIS RESULTS IN SLOWLY
MODERATING TEMPERATURES...YET SHOULD REMAIN BELOW SEASONABLE
AVERAGES EVEN BY SUNDAY. ALSO THINKING HIGHER CLOUDS WILL BECOME
MORE PREVALENT BY SUNDAY WHICH WOULD KEEP HIGHS DOWN SOMEWHAT. LONG
TERM MODELS GENERALLY IN AGREEMENT THAT NEXT WEATHER SYSTEM WILL
MATERIALIZE IN THE SOUTHERN PLAINS LATE SUNDAY AND THEN QUICKLY
APPROACHING THE SOUTHERN APPALACHIANS FROM THE SOUTHWEST ON MONDAY.
RIGHT NOW THE 00Z ECWMF IS A LITTLE FASTER THAN THE 12Z GFS AND
GIVEN THE GENERALLY ZONAL FLOW PATTERN THIS FASTER IDEA IS
FAVORED...ESPECIALLY AS A STRONGER SYSTEM DIGS INTO THE WESTERN U.S.
AND EJECTS THIS WAVE OUT ACROSS THE PLAINS AND TOWARDS THE
APPALACHIANS. THE HIGH PRESSURE WILL BE WEAKENING AND RETREATING AS
THIS SYSTEM APPROACHES BY EARLY MONDAY BUT AIRMASS APPEARS THAT IT
WILL MODERATE ENOUGH SO THAT PRECIP TYPE REMAINS JUST RAIN. HOWEVER
IT WILL BE WORTH KEEPING AN EYE ON THE TIMING OF PRECIP ARRIVAL AND
STRENGTH OF LINGERING HIGH...AS WELL AS HOW LOW INITIAL WET BULB
TEMPERATURES ARE WHEN PRECIP ARRIVES. CANT RULE OUT SOME POCKETS OF
FREEZING RAIN IF THIS COMES IN OVERNIGHT...BUT AT THIS POINT STILL A
LONG WAY OFF.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
AS OF 545 PM EST MONDAY...
VFR CONDITIONS THIS EVENING TO LOWER TO MVFR/IFR TONIGHT AS
MIXED PRECIP MOVES IN FROM THE SW. THUS LOOKING AT DETERIORATING
FLYING WEATHER LATER THIS EVENING WITH WIDESPREAD LOW CIGS AND AT
LEAST MVFR VSBYS OVER THE WEST BY DAYBREAK TUESDAY. SOME
SNOW/SLEET POSSIBLE AT THE ONSET AT BLF/ROA/BCB/LWB SHOULD CHANGE
QUICKLY TO FZRA...WHILE LYH STARTS AS FZRA WITH PERHAPS A BIT OF
PL. DAN WILL BE BORDERLINE ON FZRA BUT TEMPS SHOULD BE HUGGING
32-33F AT THE SFC SO INCLUDED A HOUR OR TWO OF -FZRA THERE EARLY
TUESDAY. WARM NOSE ALOFT TO CHANGE FZRA TO RAIN AT ALL SITES
TUESDAY AFTERNOON ALTHOUGH SPOTS LIKE KLWB/KLYH MAY KEEP -FZRA
INTO MID OR LATE AFTERNOON. RAIN BECOMES HEAVY AT TIMES TUESDAY
AFTERNOON ESPECIALLY AT BCB/ROA/LYH/DAN. WILL EXPECT TO SEE
FLUCTUATIONS IN CIGS/VSBYS BASED ON RAINFALL RATES BUT OVERALL
SHOULD BE IFR TO LIFR WITH MOUNTAIN OBSCURATIONS LIKELY. WITH THE
STRONG SE FLOW ABOVE THE SURFACE WILL ALSO BE SEEING LLWS
POTENTIAL AT ALL LOCATIONS THROUGH THE DAY TUESDAY AS LATEST
SOUNDINGS INDICATE 35-45 KTS JUST ABOVE THE SURFACE ESPCLY IN THE
AFTERNOON. THEREFORE INCLUDED LLWS AT MOST SPOTS FOR STRONG SOUTH
TO SE FLOW DEVELOPING RIGHT AFTER SUNRISE ON TUESDAY.
MODERATE TO HEAVY RAINFALL CONTINUES TUESDAY NIGHT WITH LOCATIONS
ACROSS SE WVA TRANSITIONING BACK TO SNOW BY EARLY WEDNESDAY. THIS
WILL KEEP LOW IFR/LIFR CIGS AND MVFR TO IFR VSBYS GOING TUESDAY
NIGHT AS THE CORE OF THE LOW PRESSURE SYSTEM TRACKS ACROSS THE
AREA.
RAIN CHANGES TO A SIGNIFICANT UPSLOPE EVENT BY WED WITH PERHAPS A
TRAILING DEFORMATION BAND OF SNOW WORKING EAST TOWARD THE BLUE
RIDGE WED MORNING. THIS MAY RESULT IN A FEW INCHES OF SNOW
ACCUMULATION AROUND KBLF/KLWB AND POSSIBLY A LIGHT AMOUNT EAST TO
KBCB. WIND WILL ALSO BECOME AN ISSUE ACROSS THE MOUNTAINS WITH NW
WIND GUSTS TO 45 KTS OR MORE WED WITH A SIGNIFICANT COASTAL LOW
MOVING ACROSS COASTAL NEW ENGLAND.
RAPID IMPROVEMENT WILL OCCUR ON THURSDAY AS THE STORM SYSTEM
PULLS AWAY AND DRIER AIR WORKS IN...RESULTING IN WIDESPREAD VFR
CONDITIONS. VFR THEN CONTINUES UNDER HIGH PRESSURE FOR FRIDAY
THROUGH SATURDAY.
&&
.HYDROLOGY...
AS OF NOON EST MONDAY...
MODEL CONSENSUS AND HPC GUIDANCE GENERALLY IN THE 2 TO 3 INCH RANGE
OF LIQUID QPF FOR THE IMPENDING STORM EVENT ALTHOUGH SOME SREF
ENSEMBLE MEMBERS SHOWING OVER 4 INCHES BY ABOUT 12Z WEDNESDAY THE
27TH. QUESTION IS WHAT IMPACT THE RUNOFF FROM THIS WILL HAVE ON AREA
STREAMS AND RIVERS. POINT ONE IS THAT RIVERS ARE STARTING OFF AT
VERY LOW LEVELS ESPECIALLY ACROSS THE LOWER PORTIONS OF OUR RIVER
BASINS...ACROSS THE PIEDMONT. USGS DAILY STREAMFLOW PERCENTILES AS
OF THIS MORNING ARE SHOWING NEARLY ALL PIEDMONT RIVER AND STREAM
LOCATIONS RUNNING AT FLOWS BELOW THE 25TH PERCENTILE FOR THE DATE
AND SOME BELOW THE 10TH PERCENTILE. THIS ALSO HOLDS TRUE FOR MUCH OF
THE UPPER JAMES RIVER BASIN. 60-DAY RAINFALL DEFICITS HAVE BECOME
QUITE SIGNIFICANT...REACHING 4 TO 6 INCHES IN MANY OF THESE BASINS
OR AROUND 25 PERCENT OF NORMAL. DETERMINISTIC RIVER FORECASTS ISSUED
THIS MORNING BY THE FOUR RFCS SERVING THE BLACKSBURG HYDRO SERVICE
AREA INCLUDE 48 HOURS OF QPF THROUGH 12Z WEDNESDAY OF GENERALLY 2 TO
2.5 INCHES. AT OF THIS PACKAGE NO RIVERS ARE FORECAST TO REACH FLOOD
STAGE OR EVEN ACTION STAGE (GENERALLY A FEW FEET BELOW FLOOD STAGE)
ALTHOUGH SEVERAL COME CLOSE...INCLUDING THE NORTH FORK HOLSTON RIVER
AT SALTVILLE AND GREENBRIER RIVER AT ALDERSON. THAT SAID HYDROLOGIC
MODELS TEND TO HAVE SOME DIFFICULTY AFTER EXTENDED DRY PERIODS IN
HANDLING RUNOFF WHICH IS GENERALLY MUCH MORE EFFICIENT IN THE COOL
SEASON. HENCE...THE RESPONSE ON RIVERS REMAINS SOMEWHAT UNCERTAIN
BUT NOT ENOUGH CONFIDENCE TO ISSUE A FLOOD WATCH. NOT EXPECTING MUCH
IF ANY CONVECTION WITH THIS STORM SO RAINFALL RATES SHOULD REMAIN
MODEST..IN THE 0.10 TO 0.25 INCH PER HOUR RANGE. BUT HIGHER RAINFALL
RATES IN ANY ELEVATED STORMS THAT ARE ABLE TO DEVELOP COULD LEAD TO
LOCALIZED RUNOFF PROBLEMS. THESE COULD BE HANDLED WITH SHORT-FUSE
HYDROLOGIC PRODUCTS..FLOOD ADVISORIES OR EVEN FLASH FLOOD WARNINGS
BUT THE LIKELIHOOD AT THIS POINT IS QUITE LOW FOR THIS TO OCCUR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM EST TUESDAY FOR
VAZ018>020-023-024-035.
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR
VAZ007-009>017-022-032>034-043>047-058-059.
NC...WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR
NCZ001>006-018>020.
WV...WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM EST TUESDAY FOR
WVZ045.
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR
WVZ042>044.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...JH/WP
SHORT TERM...KK
LONG TERM...SK
AVIATION...JH/RAB/WP
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
201 PM CST SUN NOV 24 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 201 PM CST SUN NOV 24 2013
MAIN SHORT TERM FORECAST CONCERN IS ON PRECIPITATION CHANCES LATER
TONIGHT...ALONG WITH HOW MUCH AND POTENTIAL FOR FREEZING DRIZZLE.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF NORTH AMERICA...SUBTROPICAL
STREAM TROUGH OVER ARIZONA...AND NORTHERN STREAM TROUGHING FROM
CENTRAL CANADA INTO NEW ENGLAND. WITHIN THIS TROUGHING...A FAIRLY
POTENT SHORTWAVE WAS SEEN DIVING SOUTHEAST THROUGH SASKATCHEWAN.
AHEAD OF THIS TROUGH...VAD WIND PROFILES DEPICT 30-45 KT 925MB WINDS
ACROSS THE EASTERN DAKOTAS AND MINNESOTA. THESE WINDS HAVE BEEN
ADVECTING WARMER AIR TOWARDS THE FORECAST AREA...WITH 925MB TEMPS
NOW PER RAP ANALYSIS AT -7 TO -12C...COMPARED TO -12 TO -14C AT 12Z.
AIRMASS REMAINS RELATIVELY DRY...THOUGH...WITH PRECIPITABLE WATER
VALUES JUST BELOW 0.25 INCH ACROSS THE UPPER MIDWEST. UPSTREAM IN
THE WAKE OF THE SHORTWAVE...ANOTHER ARCTIC AIR SURGE WAS BREWING
ACROSS THE NORTHWEST TERRITORIES WHERE TEMPERATURES ARE SITTING IN
THE SINGLE DIGITS AND TEENS ABOVE ZERO.
MODELS ARE IN GOOD AGREEMENT SLIDING THE POTENT SHORTWAVE OVER
SASKATCHEWAN SOUTHEAST INTO NORTHERN PORTIONS OF MN...WI AND MI
MONDAY MORNING...THEN HEADING OFF TO EASTERN ONTARIO DURING THE
AFTERNOON. AS THE SHORTWAVE APPROACHES TONIGHT...SFC/925/850MB WINDS
ALL INCREASE OVER THE FORECAST AREA...SETTING UP FOR A MUCH WARMER
NIGHT. IN ADDITION...THESE WINDS WILL ADVECT IN A TONGUE OF
RELATIVELY HIGHER MOISTURE FROM WESTERN KS AND EASTERN COLORADO...AS
WELL AS FROM UP IN SOUTHERN MANITOBA...NOTED BY PRECIPITABLE WATER
CLIMBING TO AROUND 0.5 INCH. THE HIGHEST PRECIPITABLE WATER IS
CONFINED TO NORTHEAST IOWA AND SOUTHERN WI WHICH WOULD THEREFORE BE
THE GREATEST CONCERN FOR PRECIPITATION. ALBEIT...THE GENERAL LOW
AMOUNT OF PRECIPITABLE WATER WILL LIKELY LIMIT THE AMOUNT OF
PRECIPITATION. REGARDING LIFT...280-290K ISENTROPIC SURFACES DEPICT
AN INCREASE OF NET ADIABATIC OMEGA ACROSS THE FORECAST AREA BETWEEN
06 AND 12Z...THEN SLIDES OFF TO THE SOUTHEAST. GENERAL MODEL
CONSENSUS HAS BEEN HOLDING STEADY SUGGESTING PRECIPITATION BREAKING
OUT ACROSS NORTHEAST IOWA LATE TONIGHT...THEN SPREADING INTO
SOUTHERN AND PERHAPS CENTRAL WISCONSIN MONDAY MORNING. SINCE
SATURATION OCCURS FROM THE LOW TO MID LEVELS OF THE ATMOSPHERE...THE
PRECIPITATION TYPE SHOULD BE MOSTLY SNOW...BUT CANNOT RULE OUT SOME
FREEZING DRIZZLE POSSIBLE EITHER AT THE ONSET OR ON THE NORTH SIDE
OF THE DEEPER MOISTURE. ANOTHER CONCERN IS PRECIPITATION BREAKING
OUT ALONG THE POTENT SHORTWAVES WARM FRONT. 24.12Z GFS/HIRESARW AND
24.15Z SREF ALL SUGGEST THAT AS THE FRONT RUNS INTO LOW LEVEL
STRATUS WHICH DEVELOPED LATE TONIGHT AHEAD OF IT...VERTICAL MOTION
WITH THE FRONT CAN PRODUCE LIGHT PRECIPITATION. THIS WOULD APPEAR TO
BE THE BEST CHANCE TO SEE FREEZING DRIZZLE. MUCH OF THE FORECAST
AREA WOULD HAVE A CONCERN FOR THIS DEVELOPING...INCLUDING NORTHEAST
IA AND SOUTHERN WI WHEN THE SNOW THERE DEPARTS.
GIVEN THAT THE PROBABILITY OF FREEZING DRIZZLE IS LOW AT THIS
TIME...ON THE ORDER OF 20 TO MAYBE 30 PERCENT...HAVE NOT ISSUED ANY
WINTER WEATHER ADVISORIES. FURTHER SHIFTS MAY NEED TO ISSUE
THEM...THOUGH...IF FREEZING DRIZZLE LOOKS MORE LIKELY TO OCCUR.
TEMPERATURE WISE...WE SHOULD SEE TEMPERATURES HOLD EITHER NEARLY
STEADY AND LIKELY RISE AFTER MIDNIGHT AS THE BREEZY SOUTH WINDS
BRING IN WARMER AIR AT THE SURFACE. THERE IS POTENTIAL FOR SOME
CLEARING MONDAY AFTERNOON...WHICH WITH 925MB TEMPS WARMING TO -2 TO -
4C IN THE AFTERNOON...HIGHS SHOULD CLIMB INTO THE 30S IN MOST
LOCATIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 201 PM CST SUN NOV 24 2013
FOCUS OF THE LONG TERM PERIOD IS ON AN ARCTIC COOL SHOT SLATED FOR
TUESDAY INTO WEDNESDAY...AND ANY POSSIBLE PRECIPITATION THURSDAY
INTO THE WEEKEND.
MODELS DEPICT ANOTHER POTENT SHORTWAVE DROPPING OUT OF THE NORTHWEST
TERRITORIES AND DOWN INTO THE FORECAST AREA ON TUESDAY. THIS POTENT
SHORTWAVE REALLY HELPS TO BRING DOWN THE ARCTIC AIR OBSERVED UP
THERE. AT THE SAME TIME...WITH THE ARCTIC COLD FRONTAL PASSAGE
OCCURRING IN THE MORNING...LOW LEVEL MOISTURE GETS TRAPPED. THIS
MOISTURE COMBINED WITH DAYTIME HEATING WILL MANIFEST ITSELF INTO A
FAIRLY WIDESPREAD STRATUS DECK. STEEP LOW LEVEL LAPSE RATES ALONG
WITH THE STRATUS DECK BEING IN THE DENDRITIC GROWTH ZONE IS LIKELY
TO LEAD TO FLURRIES AT A MINIMUM...AND WOULD NOT BE SURPRISED IF
SOME LOW CHANCES OF PRECIPITATION WILL NEED TO BE ADDED.
WITH THE ARCTIC COLD FRONTAL PASSAGE TUESDAY MORNING...EXPECT
TEMPERATURES TO NOT RISE MUCH AND IF ANYTHING WILL LIKELY FALL
DURING THE AFTERNOON HOURS. 925MB TEMPS FALL TO -12C BY 00Z
WEDNESDAY AND TO AROUND -14C BY 12Z WEDNESDAY. THERE IS A CONTINUING
NORTHWEST BREEZE THROUGH THIS PERIOD WHICH WILL TEMPER A BIT ON HOW
COLD WE GET TUESDAY NIGHT...AND LEANED MORE TOWARDS THE MET GUIDANCE
FOR LOWS. ON THE FLIP SIDE...EXPECT COLDER WIND CHILLS BECAUSE OF
THE BREEZE. SOME MODERATION TAKES PLACE IN 925MB TEMPS ON WEDNESDAY
WITH SUN SO THAT TEMPERATURES CAN CLIMB BACK INTO THE LOW TO MID
20S.
THE UPPER FLOW FROM THANKSGIVING AND BEYOND LOOKS TO CHANGE...GOING
FROM THE NORTHWESTERLY PATTERN WE HAVE BEEN IN RECENTLY TOWARDS MORE
ZONAL. THERE ARE EVEN HINTS IN THE 24.12Z ECMWF OF THE FLOW BACKING
SOUTHWESTERLY EARLY NEXT WEEK. THIS PATTERN CHANGE WILL HELP
DISLODGE SOME OF THE COLD AIR...THUS FOLLOWED A CONSENSUS FORECAST
DEPICTING A GRADUAL MODERATING TREND FOR TEMPERATURES. REGARDING
PRECIPITATION CHANCES...DURING THE PATTERN CHANGE...THERE ARE
SHORTWAVE TROUGHS TRAVERSING ACROSS NORTHERN MN INTO UPPER MI ON
THANKSGIVING AND ON SATURDAY. RIGHT NOW BASED ON THE TRACK WOULD
SUGGEST THE BETTER CHANCES FOR PRECIPITATION WOULD STAY NORTH OF THE
FORECAST AREA. HOWEVER...THAT SATURDAY SHORTWAVE TROUGH APPEARS TO
TAKE A BIT FARTHER SOUTH TRACK COMPARED TO THE ONE ON
THANKSGIVING...THUS 20 PERCENT CHANCES OF SNOW ARE IN THE
FORECAST FOR BOTH SATURDAY AND SATURDAY NIGHT. FRIDAY AND SUNDAY
APPEAR DRY AT THIS TIME BETWEEN SHORTWAVE TROUGHS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1157 AM CST SUN NOV 24 2013
CHALLENGING FORECAST PERIOD WITH RAPID AIR MASS CHANGE AND A
COUPLE OF WEATHER SYSTEMS AFFECTING THE TAFS. A WEATHER SYSTEM
WILL MOVE THROUGH THE REGION DURING THE SECOND PORTION OF THE TAF
PERIOD FROM 25.06-18Z AND IS DISJOINTED. SOME MOISTURE RETURN IN
THE LOW LEVELS WILL OCCUR ON VERY STRONG SOUTHWEST FLOW AHEAD OF A
SYSTEM APPROACHING FROM CANADA. THIS MOISTURE HAS THE POTENTIAL
FOR AN IFR OR LOW MVFR CIG AT THE TAF SITES. BECAUSE THE MOISTURE
IS STILL QUITE FAR WEST /COLORADO/...AND SO MUCH MUST COME
TOGETHER...THE CONFIDENCE IS LOWER ON THE EXACT HEIGHT THAT THE
CIGS WILL COME IN AROUND SUNRISE. WITH LIFT ALSO IN THE
AREA...SHOULD ENOUGH SATURATION OCCUR...FREEZING DRIZZLE WOULD BE
POSSIBLE DURING THE MONDAY MORNING PERIOD. AT THIS TIME THE
FEELING IS THAT THE MOISTURE IS NOT DEEP ENOUGH TO GROW DROPS
LARGE ENOUGH TO FALL OUT AS FZDZ. HOWEVER...THE POTENTIAL IS
THERE.
THE SYSTEM WILL PRODUCE VERY STRONG LOW LEVEL WINDS IN THE LOWEST
FEW THOUSAND FEET AGL...AND THUS LLWS WAS CONTINUED OVERNIGHT.
THIS LLWS FORECAST IS OF HIGHER CONFIDENCE.
THE PERIOD ENDS WITH A COLD FRONT PASSAGE...WINDS BECOMING
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1229 AM EST TUE NOV 26 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC COAST WILL MOVE EAST
AS A WEATHER SYSTEM DEVELOPS ALONG THE GULF COAST OF LOUISIANA.
LOWER CLOUDS NOW BLANKETING THE ENTIRE FA.
WATER VAPOR IMAGERY AND MSAS ANALYSIS SHOWING A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE HAS NOW DEVELOPED ALONG
THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC LIFT
AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING THE
FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR PLUS
SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL HOLD
OFF UNTIL THE OVERNIGHT HOURS. THE MODELS INDICATE ENOUGH WARMING
SHOULD OCCUR FOR ALL LIQUID PRECIPITATION. ALL SREF MEMBERS KEEP
THE SURFACE TEMPERATURE ABOVE FREEZING LATE TONIGHT...EVEN IN THE
NORTH PART. FREEZING RAIN IS NOT IMPOSSIBLE IN THE EXTREME NORTH
SECTION...BUT BELIEVE PRECIPITATION WILL BE LIGHT AT THE ONSET
LIMITING WET-BULB COOLING. ALSO...THE NAM AND GFS SHOW SURFACE
WET-BULB TEMPERATURES RISING ABOVE FREEZING BEFORE SIGNIFICANT
PRECIPITATION REACHES THE AREA LATE TONIGHT. DESPITE THE MODEL
GUIDANCE...THERE MAY BE LAYERS OF DRY AIR ALOFT WITH WET-BULB
COOLING WHICH COULD SUPPORT SLEET...MAINLY IN THE EXTREME NW
PORTIONS OF THE FA. BELIEVE ANY SLEET WOULD BE LIGHT AND WITH
SURFACE TEMPERATURES ABOVE FREEZING...SO NO ACCUMULATION SHOULD
OCCUR.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SUNDAY/...
MVFR CONDITIONS THROUGH MOST OF THE OVERNIGHT PERIOD THEN
DETERIORATING TO IFR BY 12Z.
HIGH PRESSURE WILL CONTINUE TO WEAKEN AND SHIFT EAST INTO THE
ATLANTIC AS LOW PRESSURE ALONG THE GULF COAST PUSHES NORTHEASTWARD.
DUE TO MOISTURE FLUX INTO THE AREA AHEAD OF THE APPROACHING
WEATHER SYSTEM...CEILINGS HAVE LOWERED TO MVFR AT ALL TAF SITES.
LIGHT RAIN SHOULD SPREAD INTO THE AREA BETWEEN 08Z AND 10Z AND
CONTINUE SPREADING TOWARD THE NORTHEAST AS THE SURFACE LOW
APPROACHES. BY 12Z...WIDESPREAD RAINFALL IS EXPECTED AND CONDITIONS
SHOULD DETERIORATE RAPIDLY TO IFR. MAINLY MODERATE RAIN ON TUESDAY
BUT CANNOT RULE OUT SOME HEAVY RAIN AT TIMES. MODEL SOUNDINGS AND
LOCAL SCHEME SHOWING WIND SHEAR DEVELOPING TUESDAY MORNING.
INTRODUCED WIND SHEAR OF 35 KNOTS FROM 12Z TO 24Z. ALSO WITH
INCREASING INSTABILITY ALOFT...A FEW ELEVATED THUNDERSTORMS ARE
POSSIBLE...ESPECIALLY ACROSS THE EASTERN MIDLANDS TAF SITE OGB...BUT
CONFIDENCE WAS TOO LOW TO INCLUDE IN THIS TAF PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY NIGHT AS A
LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE SOUTHEASTERN
STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
156 AM EST TUE NOV 26 2013
.SYNOPSIS...
ISSUED AT 154 AM EST TUE NOV 26 2013
A REINFORCING SHOT OF COLD AIR WILL SET THE STAGE FOR A POTENTIAL
HEAVY LAKE EFFECT SNOW EVENT TUESDAY NIGHT THROUGH WEDNESDAY
ACROSS FAR SOUTHWEST LOWER MICHIGAN AND PORTIONS OF NORTHWEST AND
NORTH CENTRAL INDIANA.
&&
.UPDATE...
ISSUED AT 700 PM EST MON NOV 25 2013
LEAD SHORTWAVE APPEARS TO BE QUITE SHEARED IN NATURE STRETCHING
FROM SOUTHERN LOWER MICHIGAN BACK INTO CENTRAL ILLINOIS THIS
EVENING. THIS WAVE WILL CONTINUE TO SLIDE EAST THROUGH THE AREA
THROUGH THE LATE EVENING. THE COMBINATION OF WEAK DPVA WITH THIS
FEATURE AND ASSOCIATED DOWNSTREAM WEAK 750-650 HPA FRONTOGENESIS
WILL SUPPORT AREA OF -SN OVERSPREADING MUCH OF EASTERN AND
SOUTHEAST PORTIONS OF THE AREA THROUGH MIDNIGHT. DRY NATURE TO AIR
MASS AND ELEVATED NATURE OF FORCING WILL ONLY LEAD TO A FEW TENTHS
OF SNOW ACCUMULATION FOR MOST LOCATIONS HOWEVER. MUCH DRIER MID
LEVEL AIR ADVECTING IN BEHIND THIS LEAD SHORT WAVE HAS CUT OFF
PRECIP ACROSS THE FAR NORTH EARLY THIS EVENING. WATER VAPOR
IMAGERY/21Z RAP INITIALIZATION DO SUGGEST PRESENCE OF NEXT
UPSTREAM VORT ACROSS SOUTHERN MINNESOTA WHICH WILL SLIDE INTO THE
WESTERN GREAT LAKES LATE TONIGHT. NOT COMPLETELY OUT OF THE
QUESTION THAT SOME PATCHY FREEZING DRIZZLE COULD ACCOMPANY THIS
WEAK FORCING...BUT GIVEN EXPECTED VERY LIGHT NATURE TO THE DRIZZLE
IF IT OCCURS WOULD EXPECT MINIMAL TO NO IMPACT SO WILL CONTINUE TO
OMIT FROM THE FORECAST. ONLY TWEAK TO PREVIOUS FORECAST WAS TO
INCREASE POPS SLIGHTLY ACROSS CENTRAL PORTIONS OF THE AREA WHERE
IT APPEARS SOME VERY WEAK ELEVATED FGEN RESPONSE HAS OCCURRED OVER
THE PAST HOUR OR TWO. EVEN ACROSS THESE LOCATIONS...ACCUMULATIONS
SHOULD ONLY TOTAL A TENTH OR TWO. ANOTHER WEAK WAVE FROM SOUTHERN
STREAM ACROSS CENTRAL ILLINOIS EVIDENT ON WATER VAPOR IMAGERY MAY
CLIP SOUTHERN PORTIONS OF FORECAST THROUGH EARLY PORTIONS OF THE
OVERNIGHT THAT COULD LEAD TO BRIEF ENHANCEMENT OF WEAK ELEVATED
FGEN...BUT LITTLE OR NO ACCUMULATION IS EXPECTED. TREND OF
DIMINISHING POPS FROM NORTHWEST TO SOUTHEAST STILL APPEARS
REASONABLE AND NO OTHER CHANGES MADE TO PREVIOUS FORECAST AT THIS
TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 340 PM EST MON NOV 25 2013
LEAD NORTHERN STREAM S/W CURRENTLY DIVING SOUTHEAST ACROSS UPPER
GREAT LAKES. WEAK SMALLER SCALE WAVES STREAMING NORTHEAST TOWARD THE
LOWER GREAT LAKES NOTED ON W/V IMAGERY THIS AFTN...EMANATING FROM
STRONG SOUTHERN LOW ACROSS PANHANDLE REGION. THE PHASING OF THESE
WEAKER P/V ANOMALIES ACROSS THE AREA...COMBINED WITH COMPACT
CORRIDOR OF DECENT ISENTROPIC LIFT...PROVIDING WIDESPREAD
PRECIPITATION ACROSS THE REGION PER RADAR. THESE SNOW SHOWERS HAVE
BEEN STRUGGLING TO REACH THE GROUND ALL DAY PER UPSTREAM SFC
OBS...GIVEN STOUT DRY BOUNDARY LAYER AND SFC DEWPOINT DEPRESSIONS ON
THE ORDER OF 10-15F. CONTINUED WITH PREVIOUS FCST TREND...MENTIONING
LIGHT SNOW WORDING/FLURRIES...ALONG WITH LIGHT ACCUMULATIONS ACROSS
THE AREA. CONFIDENCE HAS WANED FOR ANY ACCUMULATIONS GIVEN RADAR
TRENDS...HOWEVER STREAM OF MID LVL MOISTURE ADVECTING NE INTO THE
AREA NOTED ON W/V MAY LEND TO ENHANCE THESE RETURNS AND HELP TOP DOWN
SATURATION OF THE LAYER...COINCIDENT WITH THE CORRIDOR OF ISENTROPIC
LIFT.
CORRIDOR OF LIFT STRETCHES OFF TO THE EAST AFTER MIDNIGHT...WITH
DIMINISHING POPS REFLECTED IN THE GRIDS. STRONGER NORTHERN STREAM
P/V ANOMALY WILL SURGE SOUTHEAST THROUGH THE REGION ON TUESDAY...AND
WILL ATTEMPT TO PHASE WITH SOUTHERN STREAM P/V ANOMALY LATE TOMORROW
AND WEDNESDAY WELL SOUTHEAST OF THE REGION. ATLANTIC COAST SFC
CYCLONE WILL DEVELOP IN RESPONSE TO THESE FEATURES...AND BRING
WIDESPREAD PRECIP TO MUCH OF THE EASTERN US. HOWEVER...BEST
ISENTROPIC UPGLIDE SHOULD KEEP SNOWFALL SOUTH AND EAST OF THE AREA
THROUGH TUESDAY...ESPECIALLY GIVEN THE AGGRESSIVE NATURE OF THE
NORTHERN STREAM ENERGY SURGING SOUTHEAST THROUGH THE AREA.
THEREFORE...HAVE KEPT POPS OUT OF THE TUESDAY PERIOD ACROSS THE
SOUTHEAST PORTION OF THE AREA...BUT HEDGED WITH A CHANCE FLURRIES
MENTION CLOSE TO THE EDGE OF THE BEST MOISTURE/LIFT GRADIENTS. NO
MAJOR CHANCES TO TEMPS TONIGHT/TUESDAY.
ACCOMPANYING THIS STRONG NORTHERN P/V ANOMALY IS ANOTHER EARLY
SEASON SURGE OF ARCTIC AIR. THIS WILL PUSH THROUGH THE AREA TUESDAY
AFTERNOON. KEPT WITH A FLURRY MENTION ACROSS THE AREA IN THE
AFTERNOON IN THE WAKE OF THE ARCTIC FRONT. LAKE RESPONSE SHOULD
ACTIVATE TUESDAY AFTERNOON AS 850MB TEMPS CRASH TO -12C TO -13C BY
21Z TUESDAY. SHOULD BE RATHER DISORGANIZED BEFORE 00Z...AS LOW LVL
NORTHWEST FLOW SHOULD KEEP BANDING TO A MINIMUM DURING THIS PERIOD.
WENT WITH A FEW TENTHS OF SNOW ACCUMULATION ACROSS FAR SW LWR MI
FROM 18Z TO 00Z...BEFORE FLOW VEERS NORTHERLY INTO THE
OVERNIGHT...LEADING TO A SIGNIFICANT SINGLE BAND EVENT IN THE LONG
TERM PERIOD.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 340 PM EST MON NOV 25 2013
...SIGNIFICANT LAKE EFFECT SNOW EXPECTED TUE NIGHT-WED...
FCST THIS AFTN PREDICATED ON SHARPER H5 SOLUTIONS ALOFT INCLUDING
NAM/GEM/EC AND VARIOUS HIGHRES GUIDANCE AS POTENT SRN STREAM SW
PHASES W/SECONDARY NRN STREAM DROPPING SWD THROUGH NRN SK THIS AFTN.
VIGOROUS/SHARP LL CAA BURST XPCD TUE NIGHT W/DEEP NRLY LONG AXIS
FETCH DVLPG. CLEAR INDICATIONS OF LK SP CONNECTION WHICH WILL MOST
CERTAINLY AID IN BREATH OF LATENT MSTR FLUX AND MODULATE SNOWBAND
INTENSITY HIGHER. 30-35KT MEAN CLD BEARING LYR FLW SHLD ALSO YIELD A
FURTHER INLAND PENETRATION OF SNOWBANDS BUT WHERE REMAINS A BIG QN.
TYPICAL W-E SPREAD NOTED THIS AFTN ALTHOUGH A DECIDED CONSENSUS LIES
W/ERN CLUSTER OF SOLUTIONS INCLUDING MOST HIGHRES RENDITIONS ALG
W/GEM AND 4KM NAM. AT THIS POINT GIVEN HOLIDAY TRAVEL CONCERNS WILL
BROAD BRUSH A WATCH FOR LT TUE NIGHT-WED EVE ACRS MUCH OF THE WRN
CORNER. HWVR IMPACTS WILL LIKELY EXTEND FARTHER DOWNSTREAM AND WILL
ADDRESS IN HWO UPDATE.
FVRBL DGZ LOCATION WITHIN LVL OF NON DVRG NOTED IN XSCTNS ALG
W/MAXIMIZED RH AND STG ASCENT WOULD PORTEND A PD OF 1-2 INCH SNOWFALL
RATES LIKELY VRY LT TUE NIGHT INTO WED AFTN BFR WKNG. CONSERVATIVE
AGGREGATED QPF YIELDS A BROAD 6-10 INCH SNOW PLUME W/OBVIOUS HEAVIER
ACCUMS TIED TO PLACEMENT OF LK SP CONNECTED PLUME AND LESSOR ACCUMS
TIED TO WHERE WEAKER WRN DIPOLE DVLPS. BAND XPCD TO BREAKUP RAPIDLY
WED EVE IN RESPONSE TO QUICK FLATTEN OF FLW ALOFT AS EAST COAST
STORM LIFTS OUT AND AHD OF NXT UPSTREAM DISTURBANCE. TEMPS THROUGH
THE PD CONT COLD BUT MODERATION ON TAP THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 153 AM EST TUE NOV 26 2013
HIGH END MVFR TO VFR MET CONDS PREVAIL OVERNIGHT ACRS NRN IN WITH
FLURRIES COMING TO END AT KFWA SHORTLY. OTHERWISE FOCUS ON
DEVELOPMENT OF SIG LAKE EFFECT SNOWFALL FOR KSBN AREA LATE IN
FORECAST PD. TEMPO FUELING REQUIREMENTS THERE WITH HIGH LIKELIHOOD
OF FURTHER DEGRADATION INTO IFR RANGE IN HEAVIER SNOW
SQUALLS...ESPECIALLY JUST BYND CURRENT FCST PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH WEDNESDAY
EVENING FOR INZ003-004-012>015.
MI...LAKE EFFECT SNOW WATCH FROM LATE TONIGHT THROUGH WEDNESDAY
EVENING FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
LMZ043-046.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MURPHY
SHORT TERM...NG
LONG TERM...T
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1157 PM CST Mon Nov 25 2013
.UPDATE...
ISSUED AT 1157 PM CST MON NOV 25 2013
The AVIATION section has been updated for the 06Z TAF issuance.
UPDATE ISSUED AT 742 PM CST MON NOV 25 2013
A slightly more modest change in precipitation chances and other
sensible weather elements (weather, temperature, dewpoint, wind,
etc) for tonight and Tuesday morning, mainly over West Kentucky.
The current wave of precipitation and sub-synoptic lift is moving
out of the area, creating a small droplet size area of rain/mist,
as well as snow over the eastern 1/3 of the WFO PAH County warning
area.
Regional radar mosaic still showing 0 to 15/20 dBZ returns over
Central Arkansas, Southeast Misouri, Southeast Illinois, and into
Northwest Kentucky and Southwest Indiana shortly after 01z (7 pm
CST) this evening. This is coincident with the southern edge of a
differential deformation zone/moisture gradient on the 7.0 micron
(sensitive near 700 mb) and 7.4 micron (sensitive near 850 mb)
GOES Sounder Water Vapor channels. On the 11-3.9 micron GOES IR
difference channel, the aforementioned radar echoes are centered
within the mean plume of ice clouds, serving as seeder-feeder
source region.
The GEM (Canadian), SREF (Short Range Ensemble Forecast),
deterministic 18z GFS numerical guidance are similar to the high
resolution 3km HRRR model guidance for this evening and overnight.
We should see a resurgence of PoPs/Weather from the southwest into
the Missouri Bootheel and Southwest Kentucky after midnight (06z).
A sharp northern PoP/Weather gradient should develop over West
Kentucky after midnight, slowly working east-northeast through 8
am CST Tuesday, then continue to shift east during the day on
Tuesday. By 9 am CST Tuesday, most areas should remain above freezing
over the entire WFO PAH CWA, eliminating any travel concern.
For now, the most concentrated area for travel concerns between 11
pm Monday and 8 am Tuesday will be from Paducah KY (KPAH) and
Owensboro KY (KOWB) southward 25 to 30 miles through 5 am CST,
working slightly more southward another 10 to 15 miles between 5
am - 8 am CST. The combination and duration of temperatures
slightly below freezing, PoPs above 40%, and differential lift may
lead some slight glazing on elevated surface and some roadways.
For now, will issue a longer term Special Weather Statement to
address this area of travel concern, as well as post a Weather
Story graphic on the NWS Paducah web page and social media
outlets. May also highlight in the Hazardous Weather Outlook as well.
Given the marginal nature of the precipitation amounts (between
0.04" - 0.07") it will be a judgement call whether an advisory
will be needed overnight, since critical temperatures will focused
in areas where total precipitation will be less than 0.05" between
11 pm and 8 am CST. Given the effectiveness of de-icing agents
(salt, etc...) most roads should remain in good shape. The only
areas of concern will be any untreated roadways.
&&
.SHORT TERM...(This Evening through Tuesday night)
ISSUED AT 239 PM CST MON NOV 25 2013
Models were obviously too slow with precip onset with this
initial wave. Not an uncommon error. Light sleet, light rain
light snow mix across the area. Most notable precip has been
over west KY and southeast MO, near the TN state line over to
the MO bootheel region. We will maintain our SPS (Special Weather
Statement) approach vs. an advisory. A few slick spots certainly
possible though not getting really any reports of that.
Temperatures per KY mesonet into SEMO at or above freezing even
where precip has occurred. Site near Hickman is down to 32F.
Overall, still not a big deal event.
This lead wave will push the afternoon activity on to the east.
The question then becomes, how much more will we see overnight
into early Tuesday. Will maintain slight better chances overnight
south and east and taper off low chance PoPs NW overnight, and
continue with our SE 1/3 of the area PoPs Tuesday as the
southern and northern stream systems interact and draw moisture
into this area. Should be dry over the remainder of the region
Tuesday. A minimal mix precip type possible tonight into early
Tuesday a.m. Then precip should transition to mainly light
rain. Tuesday night will be dry and colder as arctic high
pressure builds south into the area.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 239 PM CST MON NOV 25 2013
With precipitation having moved east of the PAH forecast area,
Wednesday will see clearing skies as chilly and breezy conditions
persist through the day. With highs only in the lower 30s, wind
chill readings in the morning will start out in the single digits to
around 10 degrees, only improving to the lower 20s by afternoon.
The coldest period of the extended will continue into Wednesday
night, with lows in the middle to upper teens. Northwest winds at 5
to 10 mph in the evening will decrease and gradually turn back to
the southwest by daybreak.
High pressure over the central plains Wednesday will slide east of
the PAH fa by Thursday morning, thus the winds becoming southwest.
Southwest flow will lead to a gradual warm up through the weekend,
though readings will remain below normal. High temperatures on
Thanksgiving will only reach the middle to upper 30s, moderating to
the upper 40s to around 50 degrees Saturday and Sunday. Lows
Saturday night are expected to stay above freezing, which will be
the first night with above freezing temperatures since last
weekend.
ECMWF brings a surface low into the Great Lakes region by 12z
Sunday, dragging a cold front into the Mississippi River valley.
GFS is about 12 hours slower than the ECMWF. ECMWF spreads rain
across much of the PAH fa Saturday night, while GFS holds off until
late Sunday into Sunday night. Went with a compromise, keeping
Saturday night dry then including slight to low chance pops for
mainly southern Illinois and southeast Missouri on Sunday. Went
with chance pops across the entire area Sunday night into Monday.
Fortunately, temperatures look to be warm enough through the event
to keep precip all liquid.
&&
.AVIATION...
ISSUED AT 1157 PM CST MON NOV 25 2013
The upper-level storm system over Texas will shift east and phase
with a northern stream system diving over the Mississippi River by
06Z Wednesday. Lots of moisture will be drawn northward over west
Kentucky tonight, as temperatures reach saturation near the
freezing mark. Most of the precipitation will be in the very low-
levels, so drizzle or freezing drizzle would be the main
precipitation type. Most guidance is indicating a brief window
toward 12Z where deeper saturation may occur. Guidance also
indicates some warming aloft by then, so any snow aloft would likely
melt. Rain or sleet would be the main precipitation type. Will
assume temperatures stay just above freezing, so will keep
rain/sleet combination and not mention freezing rain/drizzle.
Ceilings will likely drop to IFR levels in the east and possibly
at all sites straddling 12Z. Ceilings should lift considerably by
mid-morning. Surface high pressure will build east across the area
through the afternoon, so gusty north winds will spread eastward
across the area. The gustiness will pick up during the evening
throughout the area. Some strato cu ceilings are likely later in
the evening. MVFR levels cannot be ruled out.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
328 AM EST TUE NOV 26 2013
.SYNOPSIS...
AS LOW PRESSURE MOVES UP THE EAST COAST...A WINTRY MIX WILL ENTER
THE REGION BEFORE CHANGING TO ALL SNOW AFTER MIDNIGHT. SNOW WILL
DIMINISH WEDNESDAY INTO THURSDAY...WITH DRY WEATHER UNTIL AT LEAST
SUNDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A SHORTWAVE MOVING ACROSS OHIO INTO NORTHWESTERN PENNSYLVANIA HAS
ALLOWED FOR A PRECURSOR ROUND OF SNOW IN ADVANCE OF THE MAJOR SYSTEM
ARRIVING THIS MORNING. AN INCH OF SNOW HAS FALLEN AT OUR
OFFICE...AND AREA WEBCAMS SHOW SOME LIGHT ACCUMULATIONS GENERALLY ON
GRASSY SURFACES...ALTHOUGH AREA ROADWAYS STILL APPEAR TO BE MOSTLY
WET. THIS LIGHT SNOW SHOULD CONTINUE THROUGH SUNRISE.
NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS ARE BOTH STARTING THEIR
TREK TO THE EAST...WITH THEIR INTERACTION ABOUT TO AFFECT THE ENTIRE
EAST COAST. SO FAR THE PRECIPITATION SHIELD FROM THE SOUTHERN SYSTEM
IS CONTAINED TO SOUTHERN KENTUCKY AND VIRGINIA...WITH PRECIPITATION
MOVING TO THE NORTHEAST. TRICKIEST PORTION OF THE FORECAST REMAINS
WHAT WILL HAPPEN WITH LOW LEVEL TEMPERATURE PROFILES. ENOUGH WARM
AIR IS EXPECTED TO MOVE IN ALOFT THAT A MIX OF SNOW AND FREEZING
RAIN IS POSSIBLE GENERALLY SOUTH AND EAST OF A LINE FROM ZANESVILLE
TO PITTSBURGH TO DUBOIS DURING THE DAYTIME. IN ADDITION...SURFACE
TEMPERATURES WILL BE CRITICAL...AS PRECIP MAY ACTUALLY FALL AS RAIN
FOR A SEVERAL HOUR PERIOD. LATEST RUNS OF THE RAP STILL SHOW ABOVE
FREEZING TEMPERATURES REACHING ALL THE WAY INTO INDIANA COUNTY NEAR
THE SURFACE. THE RAP CAME IN AS THE WARMEST MODEL FOR SURFACE
TEMPERATURES...BUT IT ALSO USUALLY HANDLES THESE SITUATIONS WELL.
THE HIGHER ELEVATIONS IN THE RIDGES WILL LIKELY HAVE A WINTRY MIX
THROUGH MUCH OF THIS TIME PERIOD WITH AN EXTENDED PERIOD OF FREEZING
RAIN POSSIBLE. NORTH AND WEST OF THE ZZV/PIT/DUJ LINE...SOME SLEET
MAY MIX IN BY THE AFTERNOON...BUT SNOW IS EXPECTED TO BE THE
DOMINANT PRECIPITATION TYPE.
BY EVENING THE TWO SYSTEMS ARE EXPECTED TO BE IN ENOUGH PROXIMITY TO
EACH OTHER TO DEVELOP A COUPLED JET...AND CONSEQUENTLY SHOULD BE THE
TIME PERIOD WHEN THE HIGHEST PRECIPITATION RATES OCCUR. IN THE
RIDGES...FREEZING RAIN WILL CONTINUE THROUGH THE EVENING.
TEMPERATURES WILL LIKELY STILL BE WARM ENOUGH SOUTH AND EAST OF
PITTSBURGH OUTSIDE OF THE HIGHEST ELEVATIONS TO PERSIST WITH RAIN
FOR A FEW HOURS. HOWEVER...WITH ALL SNOW FALLING TO THE WEST OF
PITTSBURGH...SNOW RATES COULD BE QUITE IMPRESSIVE DURING THE EVENING
HOURS FROM ZANESVILLE TO NEW CASTLE AND FRANKLIN. AFTER MIDNIGHT
NEARLY ALL LOCATIONS WILL CHANGEOVER TO SNOW...WITH RATES BEGINNING
TO DIMINISH SLIGHTLY. IF THE WARM LAYER ALOFT PERSISTS...WHICH
LATEST MODELS RUNS HAVE BEEN INDICATING IS POSSIBLE...FREEZING
RAIN MAY HOLD ON FOR A FEW MORE HOURS IN THE RIDGES.
ALTHOUGH ALL LOCATIONS WILL CONTINUE TO RECEIVE SNOW WEDNESDAY
MORNING...THE WIDESPREAD PRECIPITATION SHIELD WILL BE MOVING OFF TO
THE EAST. ALTHOUGH WINDS WILL INITIALLY BE OUT OF THE
NORTH-NORTHWEST...LESS FAVORABLE FOR UPSLOPE/LAKE EFFECT...WINDS
WILL BACK TO THE NORTHWEST BY THE AFTERNOON AND ALLOW THE LAKE
EFFECT MACHINE TO START UP.
ALL IN ALL...ONLY MINOR CHANGES WERE MADE TO THE FORECAST THROUGH
THIS TIME PERIOD. THE AXIS OF HEAVIEST SNOWFALL WAS PUSHED SLIGHTLY
FARTHER TO THE WEST TO ALIGN WITH DEFORMATION ZONE AND THE CHANCES
FOR FREEZING RAIN WERE HELD ONTO LONGER TONIGHT IN THE RIDGES...BUT
OTHERWISE THE INHERITED FORECAST WAS IN GOOD SHAPE. NO CHANGES WERE
NEEDED TO ANY OF THE ADVISORIES OR WARNINGS.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
UPSLOPE AND LAKE EFFECT SNOW WILL CONTINUE WEDNESDAY NIGHT. MODELS
ARE SUGGESTING THAT A DOUBLE LAKE CONNECTION BETWEEN HURON-ERIE IS
POSSIBLE...WHICH COULD RESULT IN SOME LOCALLY HIGHER TOTALS IF A
SINGLE DOMINANT BAND DEVELOP SIMILAR TO WHAT HAPPENED THIS
PREVIOUS SATURDAY. THE RETURN OF WEST-NORTHWESTERLY FLOW WILL
BRING LOWS DOWN INTO THE UPPER TEENS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
DRYING TREND CAN BE ANTICIPATED INTO THE WEEKEND AS THE UPR FLOW
FLATTENS...ALTHOUGH SUB AVG TEMPS WL CONT UNTIL WARM ADVCTN
INTENSIFIES WITH THE ADVN OF LOW PRES EARLY NXT WEEK. PASSAGE OF
THAT TROF IS GFS AND ECMWF FORECAST TO SPREAD RAIN...OR SNOW OVR
THE UPPER OH VALLEY REGION ON MONDAY AND TUESDAY. CHC POPS WERE
THUS INCLUDED FOR THAT TIME FRAME...BUT RESOLUTION OF PCPN TYPE WL
HAVE TO WAIT UNTIL THE SITUATION FURTHER MATURES.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
GRADUAL DETERIORATION TO GENL IFR CAN BE EXPECTED TODAY AS LGT
SN...THEN A MIXTURE OF WINTRY PCPN SPREADS OVR THE REGION AS LOW
PRES EMERGES FM THE GULF COAST AREA. IFR CONDITIONS WL THEN
PREVAIL THROUGH TNGT WITH COLD ADVCNT CHANGING PCPN TO ALL SNOW.
.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
WDSPRD RSTRNS WL CONT THRU WED NGT AS COLD ADVCTN INTENSIFIES IN
THE WAKE OF EXITING LOW PRES. VFR IS EXPD TO RTN LTR THU WITH BLDG
HIGH PRES AND PERSIST FOR THE RMNDR OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING FROM 7 AM THIS MORNING TO 4 AM EST
THURSDAY FOR MDZ001.
OH...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR OHZ039>041-048>050-057-058.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR OHZ059-068-069.
PA...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR PAZ013>016-020>022.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR PAZ023-029.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
WEDNESDAY FOR PAZ031-073-075.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO 4 AM EST
THURSDAY FOR PAZ074-076.
WINTER STORM WARNING FROM NOON TODAY TO 4 AM EST THURSDAY FOR
PAZ007>009.
WV...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR WVZ001-002.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR WVZ003-004.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
WEDNESDAY FOR WVZ012-021-022.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 4 AM EST
THURSDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
354 AM EST TUE NOV 26 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEASTWARD THROUGH THE
CAROLINAS AND MIDDLE ATLANTIC STATES TODAY AND TONIGHT. ARCTIC HIGH
PRESSURE WILL BUILD EAST OF THE APPALACHIANS WEDNESDAY AND WEDNESDAY
NIGHT...THEN LINGER THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM TUESDAY...
PRECIPITATION HAS BEEN A LITTLE SLOWER THAN EXPECTED TO SPREAD IN TO
CENTRAL NC THIS MORNING...WITH ONLY KINT HAVING REPORTED A LITTLE
MIX OF SLEET AND RAIN THUS FAR. ISENTROPIC UPGLIDE DRIVEN BY A
STRENGHTNEING AND EASTWARD-EXPANDING H85 LLJ OF 35-40 KTS WILL
NONETHELESS SUPPORT FURTHER LIFT AND MOISTENING TO ALLOW INCREASING
RADAR RETURNS PER KGSP RADAR TO OVERSPREAD THE NORTHWEST PIEDMONT
BETWEEN 5 AND 8 AM...PER RECENT RUNS OF THE HRRR AND RAP. THE
SPECIAL RELEASE 06Z KGSO RAOB INDICATED THIS MOISTENING PROCESS WAS
WELL UNDERWAY...WITH JUST A COUPLE OF SHALLOW...BUT STOUT DRY LAYERS
AROUND 10 THOUSAND...AND THE LOWEST 3 THOUSAND...FT REMAINING. THE
FORECAST WET BULB FREEZING LINE IS STILL FORECAST TO RETREAT ACROSS
THE PIEDMONT THROUGH 10-11 AM...A LITTLE MORE SLOWLY THAN EARLIER
PROGGED...AND STILL PROBABLY LINGERING OVER FORSYTH AND PERSON
COUNTIES UNTIL AROUND NOON OR SO. IT WILL TAKE SOME TIME FOR THE
PRECIPITATION TO EDGE INTO THE TRIANGLE - BETWEEN 8-11 AM - AND THE
COASTAL PLAIN DURING THE MIDDAY HOURS. THERE WILL CONSEQUENTLY BE
LITTLE OPPORTUNITY FOR ANYTHING BUT A CHILLY RAIN IN THOSE AREAS...
WITH THE EXCEPTION OF THE FAR NORTHERN REACHES OF NORTHERN DURHAM
COUNTY FOR AN HOUR OR TWO. THE PRECIPITATION AMOUNTS DURING THAT
TIME WILL BE SO LIGHT THAT ANY VERY LIGHT FREEZING RAIN WOULD HAVE
LITTLE TO NO IMPACT. THE BETTER CHANCE OF SEEING SEVERAL
HUNDREDTHS...TO AROUND A TENTH OF AN INCH OVER THE FAR NW
PIEDMONT...WILL OCCUR IN THE CURRENT ADVISORY AREA.
THE OTHER NOTABLE TREND IN GUIDANCE HAS BEEN FOR A MORE INLAND TRACK
OF THE SURFACE LOW TAKING SHAPE OVER THE NORTHERN GULF OF MEXICO...
AND ANOTHER PRECEDING LOW FORECAST TO DEVELOP OVER NC AND VA THIS
EVENING...AS THE FORCING FOR ASCENT ATTENDANT THE NORTHERN STREAM
OVERSPREADS THE LOW LEVEL FRONTAL ZONE. WHILE IT IS STILL LIKELY THE
MODELS ARE TOO AGGRESIVE ERRADICATING THE WEDGE AND BAREELING THE
WARM SECTOR ALL THE WAY INTO THE TRIAD THIS EVENING...IT IS HARD TO
IGNORE THIS MORE INLAND TREND EVEN IN THE HI-RES NMM AND ARW CORES
THAT TEND TO BETTER RESOLVE AND RESPECT CAD. EVEN THEY DRIVE THE
FRONTAL ZONE TO NEAR OR JUST EAST OF HWY 1...AND THIS SOLUTION SEEMS
ACCEPTABLE. BIG TEMPERATURE BUSTS REMAIN LIKELY INVOF THE
FRONT...WHICH WILL LIKELY BE CHARACTERIZED BY A 25-30 DEGREE
TEMPERATURE GRADIENT ACROSS SINGLE COUNTIES...WITH 30S IN THE
RESIUDAL IN-SITU WEDGE OVER THE WESTERN PIEDMONT...AND 60S IN THE
WARM SECTOR. TEMPERATURES WILL CHANGE LITTLE OVERNIGHT...WITH SOME
GRADUAL RISES INTO THE 60S IN THE WARM SECTOR THE MOST LIKELY CHANGE
FROM AFTERNOON TEMPS.
THE MORE INLAND WARM SECTOR PENERTATION ALSO RAISES CONCERN FOR THE
POTENTIAL FOR STRONG TO SEVERE CONVECTION...GIVEN THE EXTREME LOW
AND DEEP SHEAR PROFILES ATTENDING THE RAPIDLY DEEPENING LOW PRESSURE
SYSTEM AND INCREASINGLY-PHASED AND NEGATIVELY-TILTED TROUGH AXES
ALOFT. THIS THREAT WOULD BE HIGHEST OVER THE COASTAL PLAIN AND FAR
EASTERN SANDHILLS AND PIEDMONT AS THE NOSE OF THE LLJ ACCELERATES
ACROSS EAST-CENTRAL NC AND SUPPORTS SCATTERED SURFACE-BASED...OR
NEARLY SO...CONVECTION BETWEEN 7 PM AND 2 AM. FORECST BUFR SOUNDINGS
SUGGEST CONVECTION OF THE ELEVATED VARIETY COULD OCCUR IN THE CAD
REGIME AS WELL...WITH UP TO A FEW HUNDRED J/KG OF MUCAPE INDICATED
ACROSS ALL OF CENTRAL NC FOR SEVERAL HOURS THIS EVENING-EARLY
TONIGHT. A MID LEVEL DRY SLOT MAY LARGELY END PRECIPITATION FOR A
TIME OVERNIGHT...AFTER THE RAIN BECOMES HEAVY AT TIMES DURING THE
AFTERNOON AND EVENING HOURS. THE BULK OF THE PREVIOUSLY FORECAST ONE
TO TWO INCHES OF SOAKING RAIN (WELL BELOW FLASH FLOOD GUIDANCE)...
HIGHEST WEST...WILL HAVE FALLEN BY THAT TIME. THE LEADING EDGE OF
CONCENTRATED DCVA ATTENDING THE POTENT SOUTHERN STREAM SHORTWAVE
TROUGH OVER WEST TX SHOULD THEN RESULT IN THE REDEVELOPMENT OF
RAIN...PERHAPS IN THE FORM OF A BAND OF SHALLOW ELEVATED
CONVECTION...LATE TONIGHT INTO EARLY WEDNESDAY. AREAS OF FOG...
INCLUDING SOME DENSE OVER THE WESTERN PIEDMONT...WILL ALSO BE
PROBABLE ON THE COOL SIDE OF THE BOUNDARY TONIGHT.
&&
.SHORT TERM /WEDNESDAY/...
AS OF 345 AM TUESDAY...
GUIDANCE REMAINS CONSISTENT THAT THE DEPTH OF THE SATURATED LAYER
WILL STRUGGLE TO REACH THE MINUS 10 LEVEL...AS THE STRONGEST HEIGHT
FALLS/DYNAMICS ALOFT PIVOT NORTHEASTWARD. THE EXCEPTION WILL BE OVER
THE WESTERN AND NORTHERN PIEDMONT...WHERE BRIEF DEEPENING TO NEAR
MINUS 12...IN BAND OF LAST GASP DEFORMATION PRECIPITATION...IS
FORECAST TO OCCUR IN THE SEVERAL HOURS CENTERED AROUND 18Z. A FEW
WET FLAKES MAY CONSEQUENTLY MIX WITH THE RAIN AS THE PRECIPITATION
COMES TO AND END DURING THE AFTERNOON. AREAS OUTSIDE OF THE
DEFORMATION BAND...NAMELY OVER THE COASTAL COLAN AND PERHAPS
SANDHILLS...WILL LIKELY RECEIVE LITTLE TO NO ADDIITIONAL RAIN...WITH
JUST A PARTLY CLOUDY SKY IN THE DRY SLOT. ALL AREAS WILL EXPERIENCE
STRONG CAA...HOWVEER...WITH TEMPERATURES TUMBLING INTO THE 40S...
AND 30S OVER THE WESTERN PIEDMONT...DURING THE LATE MORNING TO EARLY
AFTERNOON HOURS. BLUSTERY NW WINDS WILL ALSO GUST TO BETWEEN 30 AND
35 MPH AS THE FRESH ARCTIC AIR MASS SURGES ACROSS THE STATE BEHIND
THE RAPIDLY DEPEENING LOW BOUND FOR NEW ENGLAND AND EASTERN
CANADA...WHICH WILL YIELD WIND CHILL VALUES ABOUT 15 DEGREES COOLER
THAN THE AFORMENTIONED AIR TEMPS IN THE 30S-40S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 250 AM TUESDAY...
WEDNESDAY NIGHT THROUGH SUNDAY: AS THE COLD FRONT MOVES FARTHER OFF
THE CAROLINA COAST AND THE LOW MOVES NE AWAY FROM THE AREA...SKIES
WILL BEGIN TO CLEAR AND LOW TEMPS FOR WEDNESDAY NIGHT WILL DROP INTO
THE LOW 20S NW TO UPPER 20S EAST. WINDS WILL REMAIN BREEZY OVERNIGHT
UNTIL THE PRESSURE GRADIENT RELAXES AND SURFACE HIGH PRESSURE MOVES
OVER THE APPALACHIANS ON THURSDAY. WITH THE COLD HIGH PRESSURE IN
PLACE...EXPECT HIGHS ON THURSDAY IN THE UPPER 30S TO LOW 40 AND
OVERNIGHT LOWS SIMILAR TO THE PREVIOUS NIGHT...LOW TO UPPER 20S. THE
SURFACE HIGH SHOULD MIGRATE OVER THE GREAT LAKES AND INTO THE
NORTHEAST BY FRIDAY WITH THE RIDGE EXTENDING SOUTHWEST INTO CENTRAL
NC WHERE IT WILL REMAIN THROUGH SUNDAY. THE RESULT WILL BE A DRY
FORECAST...MAINLY CLEAR SKIES AND COLD TEMPERATURES...WITH HIGHS
FRIDAY IN THE MID TO UPPER 40S. HIGHS SATURDAY AND SUNDAY WILL BE
DEPENDENT ON THE EASTWARD EXTENT OF THE WEDGE...BUT FOR NOW EXPECT
GRADUALLY INCREASING HIGHS IN THE EAST INTO THE MID 50S BY SUNDAY...
AND A SLOWER INCREASE IN THE NW...UPPER 40S SUNDAY. EXPECT A SIMILAR
TREND IN OVERNIGHT LOWS...MID 20S TO NEAR 30 DEGREES FRIDAY NIGHT
INCREASING SLIGHTLY INTO THE MID 20S TO LOW 30S FOR SATURDAY NIGHT.
SUNDAY NIGHT THROUGH MONDAY NIGHT: THERE ARE DIFFERENCES BETWEEN THE
MODELS WITH RESPECT TO UPPER LEVEL TROUGH AND PRECIP DEVELOPMENT FOR
THIS PART OF THE FORECAST...BUT THEY INDICATE THE RIDGE WEAKENING
AND CLOUD COVER INCREASING SUNDAY NIGHT AND MONDAY. EXPECT THE
COLUMN TO MOISTEN AND CHANCES FOR PRECIP TO INCREASE...HOWEVER
NAILING DOWN ANY TIMING IS DIFFICULT AT THIS TIME. FOR NOW WILL
GRADUALLY INCREASE PRECIP CHANCES SUNDAY NIGHT THROUGH MONDAY NIGHT.
SHOULD SEE HIGH TEMPS MODERATE A BIT...MID 50S TO LOW 60S FOR
MONDAY. OVERNIGHT LOWS GENERALLY IN THE MID 30S TO LOW 40S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24 HOUR TAF PERIOD:
THE MOST TREACHEROUS CONDITIONS FOR THE TAFS WILL BE IN THE TRIAD AS
A POTENT STORM SYSTEM MOVES IN FROM THE SOUTHWEST. NO RAIN OBSERVED
YET AT KINT AND KGSO DESPITE RADAR RETURNS ON THE 0.5 DEGREE
ELEVATION ANGLE. THIS IS OWING TO VERY DRY AIR IN THE LOWER LEVELS
WHICH WILL TAKE A WHILE TO OVERCOME BEFORE PRECIPITATION BEGINS IN
THE TRIAD. AS EVAPORATIVE COOLING OCCURS IN THE LOW LEVELS
TEMPERATURES WILL COOL TO NEAR FREEZING AND A PERIOD OF FREEZING
RAIN IS POSSIBLE AT KINT AND KGSO BEGINNING AROUND 9Z THROUGH 14Z OR
SO BEFORE WARM AIR ADVECTION CAUSES TEMPERATURES TO RECOVER. AT THIS
TIME FREEZING RAIN IS EXPECTED TO GIVE WAY TO AN EXTENDED PERIOD OF
LIGHT TO MODERATE RAIN...WITH POCKETS OF HEAVIER PRECIPITATION
THROUGH THE END OF THE TAF PERIOD. ALREADY MVFR CONDITIONS IN THE
TRIAD ARE EXPECTED TO FURTHER DETERIORATE TO IFR/LIFR AND MOST
LIKELY WILL REMAIN IN THE TANK THROUGH THE PERIOD WITH CEILINGS LESS
THAN 1000 FEET AND VISIBILITIES MAINLY IN THE MVFR RANGE.
CONDITIONS AT THE REMAINING TAF SITES WILL BE SIMILAR BUT WITHOUT
THE PERIOD OF FREEZING RAIN AT THE ONSET AS TEMPERATURES ARE
EXPECTED TO REMAIN ABOVE FREEZING THROUGH THE PERIOD. ANOTHER
CONCERN AT ALL TAF LOCATIONS WILL BE LOW LEVEL WIND SHEAR THAT IS
EXPECTED TO PICK UP JUST AFTER SUNRISE...NEAR 14Z. LIGHT EAST OR
NORTHEASTERLY WINDS IN THE LOW LEVELS WILL RAPIDLY INCREASE TO 35 TO
40 KNOTS OUT OF THE SOUTHEAST NEAR 2 KFT. WHILE THE SEVERITY OF THE
LLWS WILL DECREASE AFTER 00Z WEDNESDAY...LLWS WILL STILL BE A
CONCERN THROUGH THE END OF THE TAF PERIOD WITH THE EXCEPTION OF KRWI
WHERE THE THREAT WILL END EARLIER AS SURFACE WINDS SHOULD BE
STRONGER AND NEAR UNIDIRECTIONAL TO HELP MITIGATE SHEAR POTENTIAL.
LONG TERM: A SECOND STORM SYSTEM WILL FOLLOW RIGHT BEHIND THE FIRST
WHICH WILL CARRY INTO WEDNESDAY BEFORE CLEARING OUT WEDNESDAY NIGHT.
CONDITIONS SHOULD BE PREDOMINATELY VFR THEREAFTER UNTIL EARLY NEXT
WEEK WHEN THE NEXT SYSTEM APPROACHES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...KC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
335 AM EST TUE NOV 26 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEASTWARD THROUGH THE
CAROLINAS AND MIDDLE ATLANTIC STATES TODAY AND TONIGHT. ARCTIC HIGH
PRESSURE WILL BUILD EAST OF THE APPALACHIANS WEDNESDAY AND WEDNESDAY
NIGHT...THEN LINGER THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM TUESDAY...
PRECIPITATION HAS BEEN A LITTLE SLOWER THAN EXPECTED TO SPREAD IN TO
CENTRAL NC THIS MORNING...WITH ONLY KINT HAVING REPORTED A LITTLE
MIX OF SLEET AND RAIN THUS FAR. ISENTROPIC UPGLIDE DRIVEN BY A
STRENGHTNEING AND EASTWARD-EXPANDING H85 LLJ OF 35-40 KTS WILL
NONETHELESS SUPPORT FURTHER LIFT AND MOISTENING TO ALLOW INCREASING
RADAR RETURNS PER KGSP RADAR TO OVERSPREAD THE NORTHWEST PIEDMONT
BETWEEN 5 AND 8 AM...PER RECENT RUNS OF THE HRRR AND RAP. THE
SPECIAL RELEASE 06Z KGSO RAOB INDICATED THIS MOISTENING PROCESS WAS
WELL UNDERWAY...WITH JUST A COUPLE OF SHALLOW...BUT STOUT DRY LAYERS
AROUND 10 THOUSAND...AND THE LOWEST 3 THOUSAND...FT REMAINING. THE
FORECAST WET BULB FREEZING LINE IS STILL FORECAST TO RETREAT ACROSS
THE PIEDMONT THROUGH 10-11 AM...A LITTLE MORE SLOWLY THAN EARLIER
PROGGED...AND STILL PROBABLY LINGERING OVER FORSYTH AND PERSON
COUNTIES UNTIL AROUND NOON OR SO. IT WILL TAKE SOME TIME FOR THE
PRECIPITATION TO EDGE INTO THE TRIANGLE - BETWEEN 8-11 AM - AND THE
COASTAL PLAIN DURING THE MIDDAY HOURS. THERE WILL CONSEQUENTLY BE
LITTLE OPPORTUNITY FOR ANYTHING BUT A CHILLY RAIN IN THOSE AREAS...
WITH THE EXCEPTION OF THE FAR NORTHERN REACHES OF NORTHERN DURHAM
COUNTY FOR AN HOUR OR TWO. THE PRECIPITATION AMOUNTS DURING THAT
TIME WILL BE SO LIGHT THAT ANY VERY LIGHT FREEZING RAIN WOULD HAVE
LITTLE TO NO IMPACT. THE BETTER CHANCE OF SEEING SEVERAL
HUNDREDTHS...TO AROUND A TENTH OF AN INCH OVER THE FAR NW
PIEDMONT...WILL OCCUR IN THE CURRENT ADVISORY AREA.
THE OTHER NOTABLE TREND IN GUIDANCE HAS BEEN FOR A MORE INLAND TRACK
OF THE SURFACE LOW TAKING SHAPE OVER THE NORTHERN GULF OF MEXICO...
AND ANOTHER PRECEDING LOW FORECAST TO DEVELOP OVER NC AND VA THIS
EVENING...AS THE FORCING FOR ASCENT ATTENDANT THE NORTHERN STREAM
OVERSPREADS THE LOW LEVEL FRONTAL ZONE. WHILE IT IS STILL LIKELY THE
MODELS ARE TOO AGGRESIVE ERRADICATING THE WEDGE AND BAREELING THE
WARM SECTOR ALL THE WAY INTO THE TRIAD THIS EVENING...IT IS HARD TO
IGNORE THIS MORE INLAND TREND EVEN IN THE HI-RES NMM AND ARW CORES
THAT TEND TO BETTER RESOLVE AND RESPECT CAD. EVEN THEY DRIVE THE
FRONTAL ZONE TO NEAR OR JUST EAST OF HWY 1...AND THIS SOLUTION SEEMS
ACCEPTABLE. BIG TEMPERATURE BUSTS REMAIN LIKELY INVOF THE
FRONT...WHICH WILL LIKELY BE CHARACTERIZED BY A 25-30 DEGREE
TEMPERATURE GRADIENT ACROSS SINGLE COUNTIES...WITH 30S IN THE
RESIUDAL IN-SITU WEDGE OVER THE WESTERN PIEDMONT...AND 60S IN THE
WARM SECTOR. TEMPERATURES WILL CHANGE LITTLE OVERNIGHT...WITH SOME
GRADUAL RISES INTO THE 60S IN THE WARM SECTOR THE MOST LIKELY CHANGE
FROM AFTERNOON TEMPS.
THE MORE INLAND WARM SECTOR PENERTATION ALSO RAISES CONCERN FOR THE
POTENTIAL FOR STRONG TO SEVERE CONVECTION...GIVEN THE EXTREME LOW
AND DEEP SHEAR PROFILES ATTENDING THE RAPIDLY DEEPENING LOW PRESSURE
SYSTEM AND INCREASINGLY-PHASED AND NEGATIVELY-TILTED TROUGH AXES
ALOFT. THIS THREAT WOULD BE HIGHEST OVER THE COASTAL PLAIN AND FAR
EASTERN SANDHILLS AND PIEDMONT AS THE NOSE OF THE LLJ ACCELERATES
ACROSS EAST-CENTRAL NC AND SUPPORTS SCATTERED SURFACE-BASED...OR
NEARLY SO...CONVECTION BETWEEN 7 PM AND 2 AM. FORECST BUFR SOUNDINGS
SUGGEST CONVECTION OF THE ELEVATED VARIETY COULD OCCUR IN THE CAD
REGIME AS WELL...WITH UP TO A FEW HUNDRED J/KG OF MUCAPE INDICATED
ACROSS ALL OF CENTRAL NC FOR SEVERAL HOURS THIS EVENING-EARLY
TONIGHT. A MID LEVEL DRY SLOT MAY LARGELY END PRECIPITATION FOR A
TIME OVERNIGHT...AFTER THE RAIN BECOMES HEAVY AT TIMES DURING THE
AFTERNOON AND EVENING HOURS. THE BULK OF THE PREVIOUSLY FORECAST ONE
TO TWO INCHES OF SOAKING RAIN (WELL BELOW FLASH FLOOD GUIDANCE)...
HIGHEST WEST...WILL HAVE FALLEN BY THAT TIME. THE LEADING EDGE OF
CONCENTRATED DCVA ATTENDING THE POTENT SOUTHERN STREAM SHORTWAVE
TROUGH OVER WEST TX SHOULD THEN RESULT IN THE REDEVELOPMENT OF
RAIN...PERHAPS IN THE FORM OF A BAND OF SHALLOW ELEVATED
CONVECTION...LATE TONIGHT INTO EARLY WEDNESDAY. AREAS OF FOG...
INCLUDING SOME DENSE OVER THE WESTERN PIEDMONT...WILL ALSO BE
PROBABLE ON THE COOL SIDE OF THE BOUNDARY TONIGHT.
&&
.SHORT TERM /WEDNESDAY/...
AS OF 320 PM MONDAY...
FOR WED/WED NIGHT: MODELS ARE IN GOOD AGREEMENT ON PLACING THE
PRIMARY SURFACE LOW NEAR NYC WED MORNING AND THE SECONDARY WEAKER
LOW OVER THE VA TIDEWATER... WHICH BOTH CONSOLIDATE INTO A SINGLE
LOW OVER MAINE BY DAY`S END. THE SOUTHERN STREAM PORTION OF THE
STORM SYSTEM WILL BE WEAKENING AS IT LIFT NORTHEASTWARD THROUGH NC
FROM MID MORNING THROUGH EARLY AFTERNOON... BUT IT WILL STILL BE
QUITE POTENT INDUCING STRONG FORCING FOR ASCENT AS IT MAINTAINS A
NEGATIVE TILT. THE MID-UPPER LEVELS ACCORDING TO FORECAST SOUNDINGS
WILL DRY OUT QUITE A BIT IN THE MORNING AS A DRY SLOT PUNCHES IN
FROM THE SOUTH... SUGGESTING A TRANSITION TO PATCHY DRIZZLE (OR
PERHAPS A LITTLE FREEZING DRIZZLE IN THE FAR NW CWA WHERE SURFACE
WET BULB TEMPS WILL BE DROPPING TO AROUND 32F) AS THE COLDER AIR
ARRIVES POST-FRONT... WITH THE LOWEST 4 KM OR SO STAYING SATURATED.
A SLUG OF DPVA ASSOCIATED WITH THE NORTHERN STREAM PORTION OF THE
MID LEVEL LONGWAVE TROUGH SWINGS THROUGH NW NC WED AFTERNOON
ATTENDING A DEFORMATION ZONE ALOFT... HOWEVER THESE TOO SHOULD BE
WEAKENING AND DON`T APPEAR TO PROVIDE ENOUGH DEEP LAYER LIFT TO RE-
SATURATE THE AIR ABOVE -10C. AS SUCH... BELIEVE THAT A FEW WET
FLAKES WILL BE POSSIBLE ACROSS THE NW AND FAR NRN PIEDMONT WED
AFTERNOON AS THE COLUMN COOLS... BUT IT SHOULD BE INCONSEQUENTIAL
GIVEN THE BRIEF WINDOW OF OPPORTUNITY AND LIMITED MOISTURE ALOFT.
PASSAGE OF A WEAK POST-FRONTAL SURFACE TROUGH WED AFTERNOON WILL
SWING WINDS AROUND TO A UNIFORMLY NW DIRECTION... YIELDING CLEARING
SKIES BY EARLY EVENING AS DOWNSLOPE FLOW AND DRY AIR ADVECTION TAKES
OVER. WITH A TIGHTENING MSLP GRADIENT DUE TO THE STRENGTHENING
DEPARTING SURFACE LOW... THESE BRISK NW WINDS DURING THE DAY ARE
EXPECTED TO TOP OUT AT 15-20 MPH SUSTAINED WITH GUSTS OVER 30 MPH
POSSIBLE AS STRONG 925 MB WINDS NEAR 35 KT MIX DOWN TO THE SURFACE.
WED HIGHS ARE APT TO BE VERY CLOSE TO THE MORNING LOWS... WITH
PLUNGING THICKNESSES THROUGH THE DAY WITH STEADY COLD AIR ADVECTION
CAUSING TEMPS TO FALL SLOWLY THROUGH THE DAY. EARLY DAY HIGHS FROM
THE UPPER 30S NW TO LOWER 60S IN THE EASTERN COASTAL PLAIN...
FALLING TO THE MID 30S NW TO MID 40S EAST BY LATE AFTERNOON.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 250 AM TUESDAY...
WEDNESDAY NIGHT THROUGH SUNDAY: AS THE COLD FRONT MOVES FARTHER OFF
THE CAROLINA COAST AND THE LOW MOVES NE AWAY FROM THE AREA...SKIES
WILL BEGIN TO CLEAR AND LOW TEMPS FOR WEDNESDAY NIGHT WILL DROP INTO
THE LOW 20S NW TO UPPER 20S EAST. WINDS WILL REMAIN BREEZY OVERNIGHT
UNTIL THE PRESSURE GRADIENT RELAXES AND SURFACE HIGH PRESSURE MOVES
OVER THE APPALACHIANS ON THURSDAY. WITH THE COLD HIGH PRESSURE IN
PLACE...EXPECT HIGHS ON THURSDAY IN THE UPPER 30S TO LOW 40 AND
OVERNIGHT LOWS SIMILAR TO THE PREVIOUS NIGHT...LOW TO UPPER 20S. THE
SURFACE HIGH SHOULD MIGRATE OVER THE GREAT LAKES AND INTO THE
NORTHEAST BY FRIDAY WITH THE RIDGE EXTENDING SOUTHWEST INTO CENTRAL
NC WHERE IT WILL REMAIN THROUGH SUNDAY. THE RESULT WILL BE A DRY
FORECAST...MAINLY CLEAR SKIES AND COLD TEMPERATURES...WITH HIGHS
FRIDAY IN THE MID TO UPPER 40S. HIGHS SATURDAY AND SUNDAY WILL BE
DEPENDENT ON THE EASTWARD EXTENT OF THE WEDGE...BUT FOR NOW EXPECT
GRADUALLY INCREASING HIGHS IN THE EAST INTO THE MID 50S BY SUNDAY...
AND A SLOWER INCREASE IN THE NW...UPPER 40S SUNDAY. EXPECT A SIMILAR
TREND IN OVERNIGHT LOWS...MID 20S TO NEAR 30 DEGREES FRIDAY NIGHT
INCREASING SLIGHTLY INTO THE MID 20S TO LOW 30S FOR SATURDAY NIGHT.
SUNDAY NIGHT THROUGH MONDAY NIGHT: THERE ARE DIFFERENCES BETWEEN THE
MODELS WITH RESPECT TO UPPER LEVEL TROUGH AND PRECIP DEVELOPMENT FOR
THIS PART OF THE FORECAST...BUT THEY INDICATE THE RIDGE WEAKENING
AND CLOUD COVER INCREASING SUNDAY NIGHT AND MONDAY. EXPECT THE
COLUMN TO MOISTEN AND CHANCES FOR PRECIP TO INCREASE...HOWEVER
NAILING DOWN ANY TIMING IS DIFFICULT AT THIS TIME. FOR NOW WILL
GRADUALLY INCREASE PRECIP CHANCES SUNDAY NIGHT THROUGH MONDAY NIGHT.
SHOULD SEE HIGH TEMPS MODERATE A BIT...MID 50S TO LOW 60S FOR
MONDAY. OVERNIGHT LOWS GENERALLY IN THE MID 30S TO LOW 40S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24 HOUR TAF PERIOD:
THE MOST TREACHEROUS CONDITIONS FOR THE TAFS WILL BE IN THE TRIAD AS
A POTENT STORM SYSTEM MOVES IN FROM THE SOUTHWEST. NO RAIN OBSERVED
YET AT KINT AND KGSO DESPITE RADAR RETURNS ON THE 0.5 DEGREE
ELEVATION ANGLE. THIS IS OWING TO VERY DRY AIR IN THE LOWER LEVELS
WHICH WILL TAKE A WHILE TO OVERCOME BEFORE PRECIPITATION BEGINS IN
THE TRIAD. AS EVAPORATIVE COOLING OCCURS IN THE LOW LEVELS
TEMPERATURES WILL COOL TO NEAR FREEZING AND A PERIOD OF FREEZING
RAIN IS POSSIBLE AT KINT AND KGSO BEGINNING AROUND 9Z THROUGH 14Z OR
SO BEFORE WARM AIR ADVECTION CAUSES TEMPERATURES TO RECOVER. AT THIS
TIME FREEZING RAIN IS EXPECTED TO GIVE WAY TO AN EXTENDED PERIOD OF
LIGHT TO MODERATE RAIN...WITH POCKETS OF HEAVIER PRECIPITATION
THROUGH THE END OF THE TAF PERIOD. ALREADY MVFR CONDITIONS IN THE
TRIAD ARE EXPECTED TO FURTHER DETERIORATE TO IFR/LIFR AND MOST
LIKELY WILL REMAIN IN THE TANK THROUGH THE PERIOD WITH CEILINGS LESS
THAN 1000 FEET AND VISIBILITIES MAINLY IN THE MVFR RANGE.
CONDITIONS AT THE REMAINING TAF SITES WILL BE SIMILAR BUT WITHOUT
THE PERIOD OF FREEZING RAIN AT THE ONSET AS TEMPERATURES ARE
EXPECTED TO REMAIN ABOVE FREEZING THROUGH THE PERIOD. ANOTHER
CONCERN AT ALL TAF LOCATIONS WILL BE LOW LEVEL WIND SHEAR THAT IS
EXPECTED TO PICK UP JUST AFTER SUNRISE...NEAR 14Z. LIGHT EAST OR
NORTHEASTERLY WINDS IN THE LOW LEVELS WILL RAPIDLY INCREASE TO 35 TO
40 KNOTS OUT OF THE SOUTHEAST NEAR 2 KFT. WHILE THE SEVERITY OF THE
LLWS WILL DECREASE AFTER 00Z WEDNESDAY...LLWS WILL STILL BE A
CONCERN THROUGH THE END OF THE TAF PERIOD WITH THE EXCEPTION OF KRWI
WHERE THE THREAT WILL END EARLIER AS SURFACE WINDS SHOULD BE
STRONGER AND NEAR UNIDIRECTIONAL TO HELP MITIGATE SHEAR POTENTIAL.
LONG TERM: A SECOND STORM SYSTEM WILL FOLLOW RIGHT BEHIND THE FIRST
WHICH WILL CARRY INTO WEDNESDAY BEFORE CLEARING OUT WEDNESDAY NIGHT.
CONDITIONS SHOULD BE PREDOMINATELY VFR THEREAFTER UNTIL EARLY NEXT
WEEK WHEN THE NEXT SYSTEM APPROACHES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...GIH
LONG TERM...KC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
252 AM EST TUE NOV 26 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEASTWARD THROUGH THE
CAROLINAS AND MIDDLE ATLANTIC STATES TODAY AND TONIGHT. ARCTIC HIGH
PRESSURE WILL BUILD EAST OF THE APPALACHIANS WEDNESDAY AND WEDNESDAY
NIGHT...THEN LINGER THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM MONDAY...
TONIGHT: SURFACE HIGH PRESSURE IS CURRENTLY SHIFTING OFF THE NORTH
CAROLINA COAST. HOWEVER... THE LOW LEVELS REMAIN QUITE DRY ACROSS
THE AREA IN THE WAKE OF THE DEPARTING ARCTIC HIGH PRESSURE. ALOFT...
MID AND UPPER LEVEL MOISTURE IS BEGINNING TO STREAM INTO THE AREA IN
ASSOCIATION WITH A STRENGTHENING LOW PRESSURE SYSTEM OVER THE GULF
COAST STATES. THIS SYSTEM WILL QUICKLY APPROACH THE AREA
OVERNIGHT... SPREADING OVERCAST SKIES AND EVENTUALLY PRECIP INTO THE
WEST/NORTHWEST PIEDMONT AFTER MIDNIGHT... THEN SPREADING EASTWARD
ACROSS THE REST OF THE AREA AFTER DAYBREAK. IN FACT WE ARE ALREADY
SEEING SOME RETURNS ON RADAR THIS EVENING. CANT RULE OUT A FEW
SPRINKLES OR SLEET PELLETS LATE THIS EVENING WITH THE BEST
RETURNS... BUT THE AMOUNT OF DRY AIR IN THE LOW LEVEL (AS EVIDENT BY
THE 00Z KGSO SOUNDING ALONG WITH RAP MODELS SOUNDING FOR THE WESTERN
PIEDMONT) SUGGEST ANY PRECIP WILL HAVE A HARD TIME REACHING THE
GROUND OVER THE COURSE OF THE REST OF THE EVENING HOURS. HOWEVER...
WITH LOW LEVEL SOUTHERLY FLOW (925-850 MB) RAMPING UP BELOW THE COLD
DRY SURFACE ALONG WITH INCREASING UPPER DIVERGENCE EXPECT WE WILL
SEE A MOISTENING OF THE LOW LEVELS AND PRECIP BEGINNING TO FALL
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT AFTER MIDNIGHT TONIGHT.
TIMING WISE... THE HRRR IS SHOWING PRECIP MOVING INTO OUR FAR
NORTHWEST PIEDMONT FIRST AROUND 07-09Z... THE MOVING INTO THE REST
OF OUR NORTHWEST PIEDMONT AND WESTERN PIEDMONT COUNTIES BY 12Z...
WITH THE MEASURABLE PRECIP EXPECTED TO BE NEAR RALEIGH BY AROUND
DAYBREAK.
AS THE PRECIP MOVES INTO THE AREA EXPECT WE WILL LIKELY SEE A BRIEF
PERIOD OF SLEET THANKS TO THE DRY LOW LEVEL AIRMASS THE INITIAL
PRECIP WILL FALL THROUGH. THEN... WE WILL NEED TO TAKE A LOOK AT OUR
SURFACE WET-BULB TEMPS AND THE POTENTIAL FOR FREEZING RAIN... AS THE
WARM NOES IS FORECAST TO BE IN EXCESS OF 5 DEGREES C. AND SHOULD
KEEP ANY PRECIP IN THE FORM OF RAIN/FREEZING RAIN AFTER THE INITIAL
LOW LEVEL AIRMASS IS SATURATED. CURRENT SURFACE TEMPS HAVE LEVELED
OFF/INCREASED A BIT WITH THE CLOUD COVER MOVING INTO THE AREA... IN
THE MID TO UPPER 30S. HOWEVER... SURFACE DEWPOINTS ACROSS THE AREA
IN THE SINGLE DIGITS/TEENS WILL ALLOW FOR THE POTENTIAL TO
EVAPORATIVELY COOL OUR TEMPS TO BELOW FREEZING ACROSS PORTIONS OF
OUR NORTHWEST/NORTHERN PIEDMONT EARLY TUESDAY MORNING THROUGH AROUND
15Z OR SO. THE BELOW FREEZING SURFACE WET-BULB TEMPS WHEN SUFFICIENT
PRECIP MOVES INTO THE AREA IN THE 09-12Z TIME FRAME WILL LOWER TEMPS
TO FREEZING OR JUST BELOW FREEZING ACROSS THE COUNTIES LISTED IN OUR
WINTER WEATHER ADVISORY. WILL NOT EXPAND THE ADVISORY AT THIS
TIME... AS CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME. IF ANY
COUNTIES WOULD NEED TO BE ADDED IT WOULD BE GRANVILLE AND VANCE...
WITH PERHAPS NORTHERN PORTIONS OF DURHAM COUNTY AND NORTHWESTERN
PORTIONS OF CHATHAM COUNTY POSSIBLY CAUSING THE INCLUSION OF THESE
COUNTIES. THE REASON FOR NOT ADDING THESE COUNTIES NOW IS WE WILL
NEED HEAVY ENOUGH PRECIP TO BE ABLE TO EVAPORATIVELY COOL DOWN TO
THE WET-BULB TEMPS. GIVEN THESE AREAS ARE ON THE FRINGE OF
SUFFICIENT PRECIP AND SUB-FREEZING WET-BULB TEMPS WILL HOLD OFF FOR
NOW. EXPECT ANY FREEZING RAIN THREAT SHOULD END BY MID MORNING AS
THE SUPPLY OF COLD DRY AIR AT THE SURFACE WILL BE LIMITED THANKS TO
THE SURFACE HIGH PRESSURE CENTER MOVING OFFSHORE... CREATING AN IN-
SITU DAMMING EVENT. THUS... MAKING THE FREEZING RAIN EVENT A SELF-
LIMITING PROCESS THANKS TO THE LATENT HEATING FROM PHASE CHANGE. ANY
ICE ACCRUAL IS EXPECTED TO BE GENERALLY LIMITED TO A TENTH OF AN
INCH OR LESS... WITH THE HIGHEST AMOUNTS EXPECTED IN NORTHWEST
FORSYTH COUNTY.
LOW TEMPS FOR THIS PERIOD HAVE ALREADY OCCURRED ACROSS MOST OF THE
COASTAL PLAIN COUNTIES... IN THE MID TO UPPER 20S. TEMPS ACROSS
THESE LOCATIONS HAVE RISEN AS CLOUD COVER HAS MOVED INTO THE AREA
THIS EVENING... NOW IN THE MID 30S IN GENERAL. LOWS ACROSS THE
WESTERN AND NORTHERN PIEDMONT SHOULD OCCUR AS THE PRECIP MOVES INTO
THE AREA... WITH LOCATIONS IN THE MIDDLE OF THE CWA GENERALLY
REMAINING NEAR STEADY TONIGHT (MID TO UPPER 30S).
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
TUESDAY... PRECIP WILL BECOME WIDESPREAD ACROSS CENTRAL NC DURING
THE FIRST HALF OF THE MORNING. EXPECT WINTRY PRECIP IN THE NW
PIEDMONT TO TRANSITION TO MAINLY A COLD RAIN IN THE LATE MORNING.
POTENTIAL FOR THE ADVISORY TO BE CANCELED PRIOR TO NOON EXPIRATION
IF WARMING OCCURS SOONER OR IS STRONGER THAN EXPECTED. INCREASING
DIVERGENCE ALOFT COUPLED WITH INCREASING CONVERGENCE AS A SFC WARM
FRONT MIGRATES INLAND FROM THE COAST WILL INCREASE THE LIFT THROUGH
THE ENTIRE COLUMN. CONVERGENCE LONG THIS BOUNDARY WILL LEAD TO
ENHANCE PRECIP...LEADING TO LOCALLY HEAVY RAINFALL. BEST SHOT OF
AXIS OF HEAVY RAIN APPEARS TO EXIST IN VICINITY OF THE HIGHWAY 1
CORRIDOR. EXPECT STORM TOTALS AMOUNTS 1-2 INCHES WITH LOCALIZED
AMOUNTS AROUND 2.5 INCHES.
TEMPERATURE-WISE...COLD RAIN WILL ENTRENCH THE TRIAD IN AN IN-SITU
DAMMING EVENT AS TEMPS WILL STRUGGLE THROUGH THE 30S. THE INLAND
ADVANCING WARM FRONT WILL LIKELY CREATE A WIDE TEMP VARIANCE BETWEEN
THE TRIANGLE AND THE COASTAL PLAIN. EXPECT TEMPS TO VARY AS MUCH AS
15-20 DEGREES...RANGING THE 40S-50 IN THE TRIANGLE TO THE LOWER 60S
EAST OF I-95. LATEST MODEL GUIDANCE HAS COME MORE INLAND WITH HE SFC
LOW. IF THIS VERIFIES...POTENTIAL FOR A TEMPERATURE BUST IN VICINITY
OF THE TRIANGLE WHERE A TEMPERATURE SWING OF 10-12 DEGREES MAY
OCCUR. BASED ON LATEST GUIDANCE...MAY ADJUST TEMPS UP 4-7 DEGREES
FROM PREVIOUS FORECAST.
TUESDAY NIGHT... FORECAST STILL CHALLENGING THIS PERIOD...DEPENDENT
UPON EXTENT OF AVAILABLE SFC BASED INSTABILITY AND EVENTUAL TRACK OF
SFC LOW. WIDESPREAD RAIN OR SHOWERS WILL CONTINUE. INCREASING LOW
LEVEL JET (AS HIGH AS 60-65KTS OFF THE NAM)WIL PROVIDE INCREDIBLE
SHEAR AND STORM RELATIVE HELICITY. FORECAST MODEL SOUNDINGS MAINTAIN
A CONDITIONALLY STABLE AIR MASS WITH BEST INSTABILITY ALOFT.
EXCEPTION IS THE NAM WHICH SUGGEST THAT SFC BASED INSTABILITY MAY
OCCUR OVER OUR FAR SE COUNTIES FOR A FEW HOURS LATE TUESDAY NIGHT
(10 PM - 4 AM). BASED ON THE MODEL TREND OF A SFC LOW TRACK A LITTLE
FARTHER INLAND...SOME POTENTIAL FOR A SFC BASED THUNDERSTORM TO
OCCUR WITH A SMALL THREAT FOR A SEVERE STORM WITH DAMAGING WIND
GUSTS OR A BRIEF TORNADO THE MAIN SEVERE WEATHER THREAT.
TEMPS TUESDAY NIGHT WILL HOLD STEADY OR SLOWLY RISE ACROSS MOST
LOCATION EXCLUDING THE NW PIEDMONT WHERE TEMPS WILL HOLD STEADY.
TEMPS IN THE SANDHILLS AND COASTAL PLAIN MAY RISE OR HOLD STEADY IN
THE LOW-MID 60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 250 AM TUESDAY...
WEDNESDAY NIGHT THROUGH SUNDAY: AS THE COLD FRONT MOVES FARTHER OFF
THE CAROLINA COAST AND THE LOW MOVES NE AWAY FROM THE AREA...SKIES
WILL BEGIN TO CLEAR AND LOW TEMPS FOR WEDNESDAY NIGHT WILL DROP INTO
THE LOW 20S NW TO UPPER 20S EAST. WINDS WILL REMAIN BREEZY OVERNIGHT
UNTIL THE PRESSURE GRADIENT RELAXES AND SURFACE HIGH PRESSURE MOVES
OVER THE APPALACHIANS ON THURSDAY. WITH THE COLD HIGH PRESSURE IN
PLACE...EXPECT HIGHS ON THURSDAY IN THE UPPER 30S TO LOW 40 AND
OVERNIGHT LOWS SIMILAR TO THE PREVIOUS NIGHT...LOW TO UPPER 20S. THE
SURFACE HIGH SHOULD MIGRATE OVER THE GREAT LAKES AND INTO THE
NORTHEAST BY FRIDAY WITH THE RIDGE EXTENDING SOUTHWEST INTO CENTRAL
NC WHERE IT WILL REMAIN THROUGH SUNDAY. THE RESULT WILL BE A DRY
FORECAST...MAINLY CLEAR SKIES AND COLD TEMPERATURES...WITH HIGHS
FRIDAY IN THE MID TO UPPER 40S. HIGHS SATURDAY AND SUNDAY WILL BE
DEPENDENT ON THE EASTWARD EXTENT OF THE WEDGE...BUT FOR NOW EXPECT
GRADUALLY INCREASING HIGHS IN THE EAST INTO THE MID 50S BY SUNDAY...
AND A SLOWER INCREASE IN THE NW...UPPER 40S SUNDAY. EXPECT A SIMILAR
TREND IN OVERNIGHT LOWS...MID 20S TO NEAR 30 DEGREES FRIDAY NIGHT
INCREASING SLIGHTLY INTO THE MID 20S TO LOW 30S FOR SATURDAY NIGHT.
SUNDAY NIGHT THROUGH MONDAY NIGHT: THERE ARE DIFFERENCES BETWEEN THE
MODELS WITH RESPECT TO UPPER LEVEL TROUGH AND PRECIP DEVELOPMENT FOR
THIS PART OF THE FORECAST...BUT THEY INDICATE THE RIDGE WEAKENING
AND CLOUD COVER INCREASING SUNDAY NIGHT AND MONDAY. EXPECT THE
COLUMN TO MOISTEN AND CHANCES FOR PRECIP TO INCREASE...HOWEVER
NAILING DOWN ANY TIMING IS DIFFICULT AT THIS TIME. FOR NOW WILL
GRADUALLY INCREASE PRECIP CHANCES SUNDAY NIGHT THROUGH MONDAY NIGHT.
SHOULD SEE HIGH TEMPS MODERATE A BIT...MID 50S TO LOW 60S FOR
MONDAY. OVERNIGHT LOWS GENERALLY IN THE MID 30S TO LOW 40S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24 HOUR TAF PERIOD:
THE MOST TREACHEROUS CONDITIONS FOR THE TAFS WILL BE IN THE TRIAD AS
A POTENT STORM SYSTEM MOVES IN FROM THE SOUTHWEST. NO RAIN OBSERVED
YET AT KINT AND KGSO DESPITE RADAR RETURNS ON THE 0.5 DEGREE
ELEVATION ANGLE. THIS IS OWING TO VERY DRY AIR IN THE LOWER LEVELS
WHICH WILL TAKE A WHILE TO OVERCOME BEFORE PRECIPITATION BEGINS IN
THE TRIAD. AS EVAPORATIVE COOLING OCCURS IN THE LOW LEVELS
TEMPERATURES WILL COOL TO NEAR FREEZING AND A PERIOD OF FREEZING
RAIN IS POSSIBLE AT KINT AND KGSO BEGINNING AROUND 9Z THROUGH 14Z OR
SO BEFORE WARM AIR ADVECTION CAUSES TEMPERATURES TO RECOVER. AT THIS
TIME FREEZING RAIN IS EXPECTED TO GIVE WAY TO AN EXTENDED PERIOD OF
LIGHT TO MODERATE RAIN...WITH POCKETS OF HEAVIER PRECIPITATION
THROUGH THE END OF THE TAF PERIOD. ALREADY MVFR CONDITIONS IN THE
TRIAD ARE EXPECTED TO FURTHER DETERIORATE TO IFR/LIFR AND MOST
LIKELY WILL REMAIN IN THE TANK THROUGH THE PERIOD WITH CEILINGS LESS
THAN 1000 FEET AND VISIBILITIES MAINLY IN THE MVFR RANGE.
CONDITIONS AT THE REMAINING TAF SITES WILL BE SIMILAR BUT WITHOUT
THE PERIOD OF FREEZING RAIN AT THE ONSET AS TEMPERATURES ARE
EXPECTED TO REMAIN ABOVE FREEZING THROUGH THE PERIOD. ANOTHER
CONCERN AT ALL TAF LOCATIONS WILL BE LOW LEVEL WIND SHEAR THAT IS
EXPECTED TO PICK UP JUST AFTER SUNRISE...NEAR 14Z. LIGHT EAST OR
NORTHEASTERLY WINDS IN THE LOW LEVELS WILL RAPIDLY INCREASE TO 35 TO
40 KNOTS OUT OF THE SOUTHEAST NEAR 2 KFT. WHILE THE SEVERITY OF THE
LLWS WILL DECREASE AFTER 00Z WEDNESDAY...LLWS WILL STILL BE A
CONCERN THROUGH THE END OF THE TAF PERIOD WITH THE EXCEPTION OF KRWI
WHERE THE THREAT WILL END EARLIER AS SURFACE WINDS SHOULD BE
STRONGER AND NEAR UNIDIRECTIONAL TO HELP MITIGATE SHEAR POTENTIAL.
LONG TERM: A SECOND STORM SYSTEM WILL FOLLOW RIGHT BEHIND THE FIRST
WHICH WILL CARRY INTO WEDNESDAY BEFORE CLEARING OUT WEDNESDAY NIGHT.
CONDITIONS SHOULD BE PREDOMINATELY VFR THEREAFTER UNTIL EARLY NEXT
WEEK WHEN THE NEXT SYSTEM APPROACHES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...KC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
251 AM EST TUE NOV 26 2013
.SYNOPSIS...A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEASTWARD THROUGH THE
CAROLINAS AND MIDDLE ATLANTIC STATES TODAY AND TONIGHT. ARCTIC HIGH
PRESSURE WILL BUILD EAST OF THE APPALACHIANS WEDNESDAY AND WEDNESDAY
NIGHT...THEN LINGER THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM MONDAY...
TONIGHT: SURFACE HIGH PRESSURE IS CURRENTLY SHIFTING OFF THE NORTH
CAROLINA COAST. HOWEVER... THE LOW LEVELS REMAIN QUITE DRY ACROSS
THE AREA IN THE WAKE OF THE DEPARTING ARCTIC HIGH PRESSURE. ALOFT...
MID AND UPPER LEVEL MOISTURE IS BEGINNING TO STREAM INTO THE AREA IN
ASSOCIATION WITH A STRENGTHENING LOW PRESSURE SYSTEM OVER THE GULF
COAST STATES. THIS SYSTEM WILL QUICKLY APPROACH THE AREA
OVERNIGHT... SPREADING OVERCAST SKIES AND EVENTUALLY PRECIP INTO THE
WEST/NORTHWEST PIEDMONT AFTER MIDNIGHT... THEN SPREADING EASTWARD
ACROSS THE REST OF THE AREA AFTER DAYBREAK. IN FACT WE ARE ALREADY
SEEING SOME RETURNS ON RADAR THIS EVENING. CANT RULE OUT A FEW
SPRINKLES OR SLEET PELLETS LATE THIS EVENING WITH THE BEST
RETURNS... BUT THE AMOUNT OF DRY AIR IN THE LOW LEVEL (AS EVIDENT BY
THE 00Z KGSO SOUNDING ALONG WITH RAP MODELS SOUNDING FOR THE WESTERN
PIEDMONT) SUGGEST ANY PRECIP WILL HAVE A HARD TIME REACHING THE
GROUND OVER THE COURSE OF THE REST OF THE EVENING HOURS. HOWEVER...
WITH LOW LEVEL SOUTHERLY FLOW (925-850 MB) RAMPING UP BELOW THE COLD
DRY SURFACE ALONG WITH INCREASING UPPER DIVERGENCE EXPECT WE WILL
SEE A MOISTENING OF THE LOW LEVELS AND PRECIP BEGINNING TO FALL
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT AFTER MIDNIGHT TONIGHT.
TIMING WISE... THE HRRR IS SHOWING PRECIP MOVING INTO OUR FAR
NORTHWEST PIEDMONT FIRST AROUND 07-09Z... THE MOVING INTO THE REST
OF OUR NORTHWEST PIEDMONT AND WESTERN PIEDMONT COUNTIES BY 12Z...
WITH THE MEASURABLE PRECIP EXPECTED TO BE NEAR RALEIGH BY AROUND
DAYBREAK.
AS THE PRECIP MOVES INTO THE AREA EXPECT WE WILL LIKELY SEE A BRIEF
PERIOD OF SLEET THANKS TO THE DRY LOW LEVEL AIRMASS THE INITIAL
PRECIP WILL FALL THROUGH. THEN... WE WILL NEED TO TAKE A LOOK AT OUR
SURFACE WET-BULB TEMPS AND THE POTENTIAL FOR FREEZING RAIN... AS THE
WARM NOES IS FORECAST TO BE IN EXCESS OF 5 DEGREES C. AND SHOULD
KEEP ANY PRECIP IN THE FORM OF RAIN/FREEZING RAIN AFTER THE INITIAL
LOW LEVEL AIRMASS IS SATURATED. CURRENT SURFACE TEMPS HAVE LEVELED
OFF/INCREASED A BIT WITH THE CLOUD COVER MOVING INTO THE AREA... IN
THE MID TO UPPER 30S. HOWEVER... SURFACE DEWPOINTS ACROSS THE AREA
IN THE SINGLE DIGITS/TEENS WILL ALLOW FOR THE POTENTIAL TO
EVAPORATIVELY COOL OUR TEMPS TO BELOW FREEZING ACROSS PORTIONS OF
OUR NORTHWEST/NORTHERN PIEDMONT EARLY TUESDAY MORNING THROUGH AROUND
15Z OR SO. THE BELOW FREEZING SURFACE WET-BULB TEMPS WHEN SUFFICIENT
PRECIP MOVES INTO THE AREA IN THE 09-12Z TIME FRAME WILL LOWER TEMPS
TO FREEZING OR JUST BELOW FREEZING ACROSS THE COUNTIES LISTED IN OUR
WINTER WEATHER ADVISORY. WILL NOT EXPAND THE ADVISORY AT THIS
TIME... AS CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME. IF ANY
COUNTIES WOULD NEED TO BE ADDED IT WOULD BE GRANVILLE AND VANCE...
WITH PERHAPS NORTHERN PORTIONS OF DURHAM COUNTY AND NORTHWESTERN
PORTIONS OF CHATHAM COUNTY POSSIBLY CAUSING THE INCLUSION OF THESE
COUNTIES. THE REASON FOR NOT ADDING THESE COUNTIES NOW IS WE WILL
NEED HEAVY ENOUGH PRECIP TO BE ABLE TO EVAPORATIVELY COOL DOWN TO
THE WET-BULB TEMPS. GIVEN THESE AREAS ARE ON THE FRINGE OF
SUFFICIENT PRECIP AND SUB-FREEZING WET-BULB TEMPS WILL HOLD OFF FOR
NOW. EXPECT ANY FREEZING RAIN THREAT SHOULD END BY MID MORNING AS
THE SUPPLY OF COLD DRY AIR AT THE SURFACE WILL BE LIMITED THANKS TO
THE SURFACE HIGH PRESSURE CENTER MOVING OFFSHORE... CREATING AN IN-
SITU DAMMING EVENT. THUS... MAKING THE FREEZING RAIN EVENT A SELF-
LIMITING PROCESS THANKS TO THE LATENT HEATING FROM PHASE CHANGE. ANY
ICE ACCRUAL IS EXPECTED TO BE GENERALLY LIMITED TO A TENTH OF AN
INCH OR LESS... WITH THE HIGHEST AMOUNTS EXPECTED IN NORTHWEST
FORSYTH COUNTY.
LOW TEMPS FOR THIS PERIOD HAVE ALREADY OCCURRED ACROSS MOST OF THE
COASTAL PLAIN COUNTIES... IN THE MID TO UPPER 20S. TEMPS ACROSS
THESE LOCATIONS HAVE RISEN AS CLOUD COVER HAS MOVED INTO THE AREA
THIS EVENING... NOW IN THE MID 30S IN GENERAL. LOWS ACROSS THE
WESTERN AND NORTHERN PIEDMONT SHOULD OCCUR AS THE PRECIP MOVES INTO
THE AREA... WITH LOCATIONS IN THE MIDDLE OF THE CWA GENERALLY
REMAINING NEAR STEADY TONIGHT (MID TO UPPER 30S).
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
TUESDAY... PRECIP WILL BECOME WIDESPREAD ACROSS CENTRAL NC DURING
THE FIRST HALF OF THE MORNING. EXPECT WINTRY PRECIP IN THE NW
PIEDMONT TO TRANSITION TO MAINLY A COLD RAIN IN THE LATE MORNING.
POTENTIAL FOR THE ADVISORY TO BE CANCELED PRIOR TO NOON EXPIRATION
IF WARMING OCCURS SOONER OR IS STRONGER THAN EXPECTED. INCREASING
DIVERGENCE ALOFT COUPLED WITH INCREASING CONVERGENCE AS A SFC WARM
FRONT MIGRATES INLAND FROM THE COAST WILL INCREASE THE LIFT THROUGH
THE ENTIRE COLUMN. CONVERGENCE LONG THIS BOUNDARY WILL LEAD TO
ENHANCE PRECIP...LEADING TO LOCALLY HEAVY RAINFALL. BEST SHOT OF
AXIS OF HEAVY RAIN APPEARS TO EXIST IN VICINITY OF THE HIGHWAY 1
CORRIDOR. EXPECT STORM TOTALS AMOUNTS 1-2 INCHES WITH LOCALIZED
AMOUNTS AROUND 2.5 INCHES.
TEMPERATURE-WISE...COLD RAIN WILL ENTRENCH THE TRIAD IN AN IN-SITU
DAMMING EVENT AS TEMPS WILL STRUGGLE THROUGH THE 30S. THE INLAND
ADVANCING WARM FRONT WILL LIKELY CREATE A WIDE TEMP VARIANCE BETWEEN
THE TRIANGLE AND THE COASTAL PLAIN. EXPECT TEMPS TO VARY AS MUCH AS
15-20 DEGREES...RANGING THE 40S-50 IN THE TRIANGLE TO THE LOWER 60S
EAST OF I-95. LATEST MODEL GUIDANCE HAS COME MORE INLAND WITH HE SFC
LOW. IF THIS VERIFIES...POTENTIAL FOR A TEMPERATURE BUST IN VICINITY
OF THE TRIANGLE WHERE A TEMPERATURE SWING OF 10-12 DEGREES MAY
OCCUR. BASED ON LATEST GUIDANCE...MAY ADJUST TEMPS UP 4-7 DEGREES
FROM PREVIOUS FORECAST.
TUESDAY NIGHT... FORECAST STILL CHALLENGING THIS PERIOD...DEPENDENT
UPON EXTENT OF AVAILABLE SFC BASED INSTABILITY AND EVENTUAL TRACK OF
SFC LOW. WIDESPREAD RAIN OR SHOWERS WILL CONTINUE. INCREASING LOW
LEVEL JET (AS HIGH AS 60-65KTS OFF THE NAM)WIL PROVIDE INCREDIBLE
SHEAR AND STORM RELATIVE HELICITY. FORECAST MODEL SOUNDINGS MAINTAIN
A CONDITIONALLY STABLE AIR MASS WITH BEST INSTABILITY ALOFT.
EXCEPTION IS THE NAM WHICH SUGGEST THAT SFC BASED INSTABILITY MAY
OCCUR OVER OUR FAR SE COUNTIES FOR A FEW HOURS LATE TUESDAY NIGHT
(10 PM - 4 AM). BASED ON THE MODEL TREND OF A SFC LOW TRACK A LITTLE
FARTHER INLAND...SOME POTENTIAL FOR A SFC BASED THUNDERSTORM TO
OCCUR WITH A SMALL THREAT FOR A SEVERE STORM WITH DAMAGING WIND
GUSTS OR A BRIEF TORNADO THE MAIN SEVERE WEATHER THREAT.
TEMPS TUESDAY NIGHT WILL HOLD STEADY OR SLOWLY RISE ACROSS MOST
LOCATION EXCLUDING THE NW PIEDMONT WHERE TEMPS WILL HOLD STEADY.
TEMPS IN THE SANDHILLS AND COASTAL PLAIN MAY RISE OR HOLD STEADY IN
THE LOW-MID 60S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY NIGHT/... AS OF 250 AM
TUESDAY...
WEDNESDAY NIGHT THROUGH SUNDAY: AS THE COLD FRONT MOVES FARTHER OFF
THE CAROLINA COAST AND THE LOW MOVES NE AWAY FROM THE AREA...SKIES
WILL BEGIN TO CLEAR AND LOW TEMPS FOR WEDNESDAY NIGHT WILL DROP INTO
THE LOW 20S NW TO UPPER 20S EAST. WINDS WILL REMAIN BREEZY OVERNIGHT
UNTIL THE PRESSURE GRADIENT RELAXES AND SURFACE HIGH PRESSURE MOVES
OVER THE APPALACHIANS ON THURSDAY. WITH THE COLD HIGH PRESSURE IN
PLACE...EXPECT HIGHS ON THURSDAY IN THE UPPER 30S TO LOW 40 AND
OVERNIGHT LOWS SIMILAR TO THE PREVIOUS NIGHT...LOW TO UPPER 20S. THE
SURFACE HIGH SHOULD MIGRATE OVER THE GREAT LAKES AND INTO THE
NORTHEAST BY FRIDAY WITH THE RIDGE EXTENDING SOUTHWEST INTO CENTRAL
NC WHERE IT WILL REMAIN THROUGH SUNDAY. THE RESULT WILL BE A DRY
FORECAST...MAINLY CLEAR SKIES AND COLD TEMPERATURES...WITH HIGHS
FRIDAY IN THE MID TO UPPER 40S. HIGHS SATURDAY AND SUNDAY WILL BE
DEPENDENT ON THE EASTWARD EXTENT OF THE WEDGE...BUT FOR NOW EXPECT
GRADUALLY INCREASING HIGHS IN THE EAST INTO THE MID 50S BY SUNDAY...
AND A SLOWER INCREASE IN THE NW...UPPER 40S SUNDAY. EXPECT A SIMILAR
TREND IN OVERNIGHT LOWS...MID 20S TO NEAR 30 DEGREES FRIDAY NIGHT
INCREASING SLIGHTLY INTO THE MID 20S TO LOW 30S FOR SATURDAY NIGHT.
SUNDAY NIGHT THROUGH MONDAY NIGHT: THERE ARE DIFFERENCES BETWEEN THE
MODELS WITH RESPECT TO UPPER LEVEL TROUGH AND PRECIP DEVELOPMENT FOR
THIS PART OF THE FORECAST...BUT THEY INDICATE THE RIDGE WEAKENING
AND CLOUD COVER INCREASING SUNDAY NIGHT AND MONDAY. EXPECT THE
COLUMN TO MOISTEN AND CHANCES FOR PRECIP TO INCREASE...HOWEVER
NAILING DOWN ANY TIMING IS DIFFICULT AT THIS TIME. FOR NOW WILL
GRADUALLY INCREASE PRECIP CHANCES SUNDAY NIGHT THROUGH MONDAY NIGHT.
SHOULD SEE HIGH TEMPS MODERATE A BIT...MID 50S TO LOW 60S FOR
MONDAY. OVERNIGHT LOWS GENERALLY IN THE MID 30S TO LOW 40S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24 HOUR TAF PERIOD:
THE MOST TREACHEROUS CONDITIONS FOR THE TAFS WILL BE IN THE TRIAD AS
A POTENT STORM SYSTEM MOVES IN FROM THE SOUTHWEST. NO RAIN OBSERVED
YET AT KINT AND KGSO DESPITE RADAR RETURNS ON THE 0.5 DEGREE
ELEVATION ANGLE. THIS IS OWING TO VERY DRY AIR IN THE LOWER LEVELS
WHICH WILL TAKE A WHILE TO OVERCOME BEFORE PRECIPITATION BEGINS IN
THE TRIAD. AS EVAPORATIVE COOLING OCCURS IN THE LOW LEVELS
TEMPERATURES WILL COOL TO NEAR FREEZING AND A PERIOD OF FREEZING
RAIN IS POSSIBLE AT KINT AND KGSO BEGINNING AROUND 9Z THROUGH 14Z OR
SO BEFORE WARM AIR ADVECTION CAUSES TEMPERATURES TO RECOVER. AT THIS
TIME FREEZING RAIN IS EXPECTED TO GIVE WAY TO AN EXTENDED PERIOD OF
LIGHT TO MODERATE RAIN...WITH POCKETS OF HEAVIER PRECIPITATION
THROUGH THE END OF THE TAF PERIOD. ALREADY MVFR CONDITIONS IN THE
TRIAD ARE EXPECTED TO FURTHER DETERIORATE TO IFR/LIFR AND MOST
LIKELY WILL REMAIN IN THE TANK THROUGH THE PERIOD WITH CEILINGS LESS
THAN 1000 FEET AND VISIBILITIES MAINLY IN THE MVFR RANGE.
CONDITIONS AT THE REMAINING TAF SITES WILL BE SIMILAR BUT WITHOUT
THE PERIOD OF FREEZING RAIN AT THE ONSET AS TEMPERATURES ARE
EXPECTED TO REMAIN ABOVE FREEZING THROUGH THE PERIOD. ANOTHER
CONCERN AT ALL TAF LOCATIONS WILL BE LOW LEVEL WIND SHEAR THAT IS
EXPECTED TO PICK UP JUST AFTER SUNRISE...NEAR 14Z. LIGHT EAST OR
NORTHEASTERLY WINDS IN THE LOW LEVELS WILL RAPIDLY INCREASE TO 35 TO
40 KNOTS OUT OF THE SOUTHEAST NEAR 2 KFT. WHILE THE SEVERITY OF THE
LLWS WILL DECREASE AFTER 00Z WEDNESDAY...LLWS WILL STILL BE A
CONCERN THROUGH THE END OF THE TAF PERIOD WITH THE EXCEPTION OF KRWI
WHERE THE THREAT WILL END EARLIER AS SURFACE WINDS SHOULD BE
STRONGER AND NEAR UNIDIRECTIONAL TO HELP MITIGATE SHEAR POTENTIAL.
LONG TERM: A SECOND STORM SYSTEM WILL FOLLOW RIGHT BEHIND THE FIRST
WHICH WILL CARRY INTO WEDNESDAY BEFORE CLEARING OUT WEDNESDAY NIGHT.
CONDITIONS SHOULD BE PREDOMINATELY VFR THEREAFTER UNTIL EARLY NEXT
WEEK WHEN THE NEXT SYSTEM APPROACHES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...MWS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...KC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
114 AM EST TUE NOV 26 2013
.SYNOPSIS... A LOW PRESSURE SYSTEM WILL DEVELOP IN THE GULF OF
MEXICO TONIGHT...THEN INTENSIFY AND TRACK NORTHEAST ALONG THE
CAROLINA AND MID ATLANTIC COAST LATE TUESDAY THROUGH WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1045 PM MONDAY...
TONIGHT: SURFACE HIGH PRESSURE IS CURRENTLY SHIFTING OFF THE NORTH
CAROLINA COAST. HOWEVER... THE LOW LEVELS REMAIN QUITE DRY ACROSS
THE AREA IN THE WAKE OF THE DEPARTING ARCTIC HIGH PRESSURE. ALOFT...
MID AND UPPER LEVEL MOISTURE IS BEGINNING TO STREAM INTO THE AREA IN
ASSOCIATION WITH A STRENGTHENING LOW PRESSURE SYSTEM OVER THE GULF
COAST STATES. THIS SYSTEM WILL QUICKLY APPROACH THE AREA
OVERNIGHT... SPREADING OVERCAST SKIES AND EVENTUALLY PRECIP INTO THE
WEST/NORTHWEST PIEDMONT AFTER MIDNIGHT... THEN SPREADING EASTWARD
ACROSS THE REST OF THE AREA AFTER DAYBREAK. IN FACT WE ARE ALREADY
SEEING SOME RETURNS ON RADAR THIS EVENING. CANT RULE OUT A FEW
SPRINKLES OR SLEET PELLETS LATE THIS EVENING WITH THE BEST
RETURNS... BUT THE AMOUNT OF DRY AIR IN THE LOW LEVEL (AS EVIDENT BY
THE 00Z KGSO SOUNDING ALONG WITH RAP MODELS SOUNDING FOR THE WESTERN
PIEDMONT) SUGGEST ANY PRECIP WILL HAVE A HARD TIME REACHING THE
GROUND OVER THE COURSE OF THE REST OF THE EVENING HOURS. HOWEVER...
WITH LOW LEVEL SOUTHERLY FLOW (925-850 MB) RAMPING UP BELOW THE COLD
DRY SURFACE ALONG WITH INCREASING UPPER DIVERGENCE EXPECT WE WILL
SEE A MOISTENING OF THE LOW LEVELS AND PRECIP BEGINNING TO FALL
ACROSS THE WESTERN/NORTHWESTERN PIEDMONT AFTER MIDNIGHT TONIGHT.
TIMING WISE... THE HRRR IS SHOWING PRECIP MOVING INTO OUR FAR
NORTHWEST PIEDMONT FIRST AROUND 07-09Z... THE MOVING INTO THE REST
OF OUR NORTHWEST PIEDMONT AND WESTERN PIEDMONT COUNTIES BY 12Z...
WITH THE MEASURABLE PRECIP EXPECTED TO BE NEAR RALEIGH BY AROUND
DAYBREAK.
AS THE PRECIP MOVES INTO THE AREA EXPECT WE WILL LIKELY SEE A BRIEF
PERIOD OF SLEET THANKS TO THE DRY LOW LEVEL AIRMASS THE INITIAL
PRECIP WILL FALL THROUGH. THEN... WE WILL NEED TO TAKE A LOOK AT OUR
SURFACE WET-BULB TEMPS AND THE POTENTIAL FOR FREEZING RAIN... AS THE
WARM NOES IS FORECAST TO BE IN EXCESS OF 5 DEGREES C. AND SHOULD
KEEP ANY PRECIP IN THE FORM OF RAIN/FREEZING RAIN AFTER THE INITIAL
LOW LEVEL AIRMASS IS SATURATED. CURRENT SURFACE TEMPS HAVE LEVELED
OFF/INCREASED A BIT WITH THE CLOUD COVER MOVING INTO THE AREA... IN
THE MID TO UPPER 30S. HOWEVER... SURFACE DEWPOINTS ACROSS THE AREA
IN THE SINGLE DIGITS/TEENS WILL ALLOW FOR THE POTENTIAL TO
EVAPORATIVELY COOL OUR TEMPS TO BELOW FREEZING ACROSS PORTIONS OF
OUR NORTHWEST/NORTHERN PIEDMONT EARLY TUESDAY MORNING THROUGH AROUND
15Z OR SO. THE BELOW FREEZING SURFACE WET-BULB TEMPS WHEN SUFFICIENT
PRECIP MOVES INTO THE AREA IN THE 09-12Z TIME FRAME WILL LOWER TEMPS
TO FREEZING OR JUST BELOW FREEZING ACROSS THE COUNTIES LISTED IN OUR
WINTER WEATHER ADVISORY. WILL NOT EXPAND THE ADVISORY AT THIS
TIME... AS CONFIDENCE IS NOT HIGH ENOUGH AT THIS TIME. IF ANY
COUNTIES WOULD NEED TO BE ADDED IT WOULD BE GRANVILLE AND VANCE...
WITH PERHAPS NORTHERN PORTIONS OF DURHAM COUNTY AND NORTHWESTERN
PORTIONS OF CHATHAM COUNTY POSSIBLY CAUSING THE INCLUSION OF THESE
COUNTIES. THE REASON FOR NOT ADDING THESE COUNTIES NOW IS WE WILL
NEED HEAVY ENOUGH PRECIP TO BE ABLE TO EVAPORATIVELY COOL DOWN TO
THE WET-BULB TEMPS. GIVEN THESE AREAS ARE ON THE FRINGE OF
SUFFICIENT PRECIP AND SUB-FREEZING WET-BULB TEMPS WILL HOLD OFF FOR
NOW. EXPECT ANY FREEZING RAIN THREAT SHOULD END BY MID MORNING AS
THE SUPPLY OF COLD DRY AIR AT THE SURFACE WILL BE LIMITED THANKS TO
THE SURFACE HIGH PRESSURE CENTER MOVING OFFSHORE... CREATING AN IN-
SITU DAMMING EVENT. THUS... MAKING THE FREEZING RAIN EVENT A SELF-
LIMITING PROCESS THANKS TO THE LATENT HEATING FROM PHASE CHANGE. ANY
ICE ACCRUAL IS EXPECTED TO BE GENERALLY LIMITED TO A TENTH OF AN
INCH OR LESS... WITH THE HIGHEST AMOUNTS EXPECTED IN NORTHWEST
FORSYTH COUNTY.
LOW TEMPS FOR THIS PERIOD HAVE ALREADY OCCURRED ACROSS MOST OF THE
COASTAL PLAIN COUNTIES... IN THE MID TO UPPER 20S. TEMPS ACROSS
THESE LOCATIONS HAVE RISEN AS CLOUD COVER HAS MOVED INTO THE AREA
THIS EVENING... NOW IN THE MID 30S IN GENERAL. LOWS ACROSS THE
WESTERN AND NORTHERN PIEDMONT SHOULD OCCUR AS THE PRECIP MOVES INTO
THE AREA... WITH LOCATIONS IN THE MIDDLE OF THE CWA GENERALLY
REMAINING NEAR STEADY TONIGHT (MID TO UPPER 30S).
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
TUESDAY... PRECIP WILL BECOME WIDESPREAD ACROSS CENTRAL NC DURING
THE FIRST HALF OF THE MORNING. EXPECT WINTRY PRECIP IN THE NW
PIEDMONT TO TRANSITION TO MAINLY A COLD RAIN IN THE LATE MORNING.
POTENTIAL FOR THE ADVISORY TO BE CANCELED PRIOR TO NOON EXPIRATION
IF WARMING OCCURS SOONER OR IS STRONGER THAN EXPECTED. INCREASING
DIVERGENCE ALOFT COUPLED WITH INCREASING CONVERGENCE AS A SFC WARM
FRONT MIGRATES INLAND FROM THE COAST WILL INCREASE THE LIFT THROUGH
THE ENTIRE COLUMN. CONVERGENCE LONG THIS BOUNDARY WILL LEAD TO
ENHANCE PRECIP...LEADING TO LOCALLY HEAVY RAINFALL. BEST SHOT OF
AXIS OF HEAVY RAIN APPEARS TO EXIST IN VICINITY OF THE HIGHWAY 1
CORRIDOR. EXPECT STORM TOTALS AMOUNTS 1-2 INCHES WITH LOCALIZED
AMOUNTS AROUND 2.5 INCHES.
TEMPERATURE-WISE...COLD RAIN WILL ENTRENCH THE TRIAD IN AN IN-SITU
DAMMING EVENT AS TEMPS WILL STRUGGLE THROUGH THE 30S. THE INLAND
ADVANCING WARM FRONT WILL LIKELY CREATE A WIDE TEMP VARIANCE BETWEEN
THE TRIANGLE AND THE COASTAL PLAIN. EXPECT TEMPS TO VARY AS MUCH AS
15-20 DEGREES...RANGING THE 40S-50 IN THE TRIANGLE TO THE LOWER 60S
EAST OF I-95. LATEST MODEL GUIDANCE HAS COME MORE INLAND WITH HE SFC
LOW. IF THIS VERIFIES...POTENTIAL FOR A TEMPERATURE BUST IN VICINITY
OF THE TRIANGLE WHERE A TEMPERATURE SWING OF 10-12 DEGREES MAY
OCCUR. BASED ON LATEST GUIDANCE...MAY ADJUST TEMPS UP 4-7 DEGREES
FROM PREVIOUS FORECAST.
TUESDAY NIGHT... FORECAST STILL CHALLENGING THIS PERIOD...DEPENDENT
UPON EXTENT OF AVAILABLE SFC BASED INSTABILITY AND EVENTUAL TRACK OF
SFC LOW. WIDESPREAD RAIN OR SHOWERS WILL CONTINUE. INCREASING LOW
LEVEL JET (AS HIGH AS 60-65KTS OFF THE NAM)WIL PROVIDE INCREDIBLE
SHEAR AND STORM RELATIVE HELICITY. FORECAST MODEL SOUNDINGS MAINTAIN
A CONDITIONALLY STABLE AIR MASS WITH BEST INSTABILITY ALOFT.
EXCEPTION IS THE NAM WHICH SUGGEST THAT SFC BASED INSTABILITY MAY
OCCUR OVER OUR FAR SE COUNTIES FOR A FEW HOURS LATE TUESDAY NIGHT
(10 PM - 4 AM). BASED ON THE MODEL TREND OF A SFC LOW TRACK A LITTLE
FARTHER INLAND...SOME POTENTIAL FOR A SFC BASED THUNDERSTORM TO
OCCUR WITH A SMALL THREAT FOR A SEVERE STORM WITH DAMAGING WIND
GUSTS OR A BRIEF TORNADO THE MAIN SEVERE WEATHER THREAT.
TEMPS TUESDAY NIGHT WILL HOLD STEADY OR SLOWLY RISE ACROSS MOST
LOCATION EXCLUDING THE NW PIEDMONT WHERE TEMPS WILL HOLD STEADY.
TEMPS IN THE SANDHILLS AND COASTAL PLAIN MAY RISE OR HOLD STEADY IN
THE LOW-MID 60S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 325 PM MONDAY...
FOR WED/WED NIGHT: MODELS ARE IN GOOD AGREEMENT ON PLACING THE
PRIMARY SURFACE LOW NEAR NYC WED MORNING AND THE SECONDARY WEAKER
LOW OVER THE VA TIDEWATER... WHICH BOTH CONSOLIDATE INTO A SINGLE
LOW OVER MAINE BY DAY`S END. THE SOUTHERN STREAM PORTION OF THE
STORM SYSTEM WILL BE WEAKENING AS IT LIFT NORTHEASTWARD THROUGH NC
FROM MID MORNING THROUGH EARLY AFTERNOON... BUT IT WILL STILL BE
QUITE POTENT INDUCING STRONG FORCING FOR ASCENT AS IT MAINTAINS A
NEGATIVE TILT. THE MID-UPPER LEVELS ACCORDING TO FORECAST SOUNDINGS
WILL DRY OUT QUITE A BIT IN THE MORNING AS A DRY SLOT PUNCHES IN
FROM THE SOUTH... SUGGESTING A TRANSITION TO PATCHY DRIZZLE (OR
PERHAPS A LITTLE FREEZING DRIZZLE IN THE FAR NW CWA WHERE SURFACE
WET BULB TEMPS WILL BE DROPPING TO AROUND 32F) AS THE COLDER AIR
ARRIVES POST-FRONT... WITH THE LOWEST 4 KM OR SO STAYING SATURATED.
A SLUG OF DPVA ASSOCIATED WITH THE NORTHERN STREAM PORTION OF THE
MID LEVEL LONGWAVE TROUGH SWINGS THROUGH NW NC WED AFTERNOON
ATTENDING A DEFORMATION ZONE ALOFT... HOWEVER THESE TOO SHOULD BE
WEAKENING AND DON`T APPEAR TO PROVIDE ENOUGH DEEP LAYER LIFT TO RE-
SATURATE THE AIR ABOVE -10C. AS SUCH... BELIEVE THAT A FEW WET
FLAKES WILL BE POSSIBLE ACROSS THE NW AND FAR NRN PIEDMONT WED
AFTERNOON AS THE COLUMN COOLS... BUT IT SHOULD BE INCONSEQUENTIAL
GIVEN THE BRIEF WINDOW OF OPPORTUNITY AND LIMITED MOISTURE ALOFT.
PASSAGE OF A WEAK POST-FRONTAL SURFACE TROUGH WED AFTERNOON WILL
SWING WINDS AROUND TO A UNIFORMLY NW DIRECTION... YIELDING CLEARING
SKIES BY EARLY EVENING AS DOWNSLOPE FLOW AND DRY AIR ADVECTION TAKES
OVER. WITH A TIGHTENING MSLP GRADIENT DUE TO THE STRENGTHENING
DEPARTING SURFACE LOW... THESE BRISK NW WINDS DURING THE DAY ARE
EXPECTED TO TOP OUT AT 15-20 MPH SUSTAINED WITH GUSTS OVER 30 MPH
POSSIBLE AS STRONG 925 MB WINDS NEAR 35 KT MIX DOWN TO THE SURFACE.
WED HIGHS ARE APT TO BE VERY CLOSE TO THE MORNING LOWS... WITH
PLUNGING THICKNESSES THROUGH THE DAY WITH STEADY COLD AIR ADVECTION
CAUSING TEMPS TO FALL SLOWLY THROUGH THE DAY. EARLY DAY HIGHS FROM
THE UPPER 30S NW TO LOWER 60S IN THE EASTERN COASTAL PLAIN...
FALLING TO THE MID 30S NW TO MID 40S EAST BY LATE AFTERNOON. DEW
POINTS WILL FALL INTO THE TEENS TO LOWER 20S OVERNIGHT WITH CLEARING
SKIES... BUT THE CONTINUED LOW LEVEL MIXING WILL KEEP TEMPS FROM
FALLING TOO LOW... BUT STILL CHILLY WITH LOWS 22-28. LATE DAY WIND
CHILLS ARE EXPECTED TO FALL INTO THE 20S OVER THE PIEDMONT... AND
INTO THE TEENS TO AROUND 20 AREAWIDE WED NIGHT WITH DIMINISHING
WINDS.
FOR THU/THU NIGHT: THE CORE OF THE MID LEVEL TROUGH WILL BE WELL TO
OUR NE BY THU MORNING... ALTHOUGH BROAD FLAT TROUGHING WILL PERSIST
OVER THE EASTERN CONUS AS A VORTEX SPINS OFF CA WITH WEAK LONGWAVE
RIDGING IN BETWEEN. SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA
FROM THE WSW AND DRIFT OVER THE SRN/CENTRAL APPALACHIANS AND MID-
ATLANTIC THROUGH THU NIGHT. EXPECT A DRY AND SUBSIDING COLUMN WITH
JUST A FEW HIGH CLOUDS AS ONE LAST WEAK PERTURBATION SWEEPS OVER THE
REGION. MAX TEMPS SHOULD BE COMPARABLE TO YESTERDAY GIVEN A SIMILAR
AIR MASS WITH SIMILAR (PERHAPS A BIT HIGHER) PREDICTED THICKNESSES.
HIGHS 38-45. MOSTLY CLEAR AND CONTINUED COLD THU NIGHT. LOWS 22-27
LOOK GOOD.
FOR FRI THROUGH MON: THE SRN STREAM PORTION OF THE SURFACE HIGH WILL
MERGE WITH THE POLAR HIGH TO BE CENTERED OVER MAINE/SW QUEBEC AND
NOSE TO THE SSW THROUGH CENTRAL NC FRI THROUGH SAT... AS THE MID
LEVEL FLOW OVER THE CENTRAL/ERN CONUS FLATTENS. AN INVERTED TROUGH
IS EXPECTED TO FORM ALONG THE SOUTHEAST COAST OVER THE WEEKEND...
AND THE ENHANCED ONSHORE-DIRECTED LOW LEVEL FLOW SHOULD PULL
INCREASING LOW LEVEL ATLANTIC MOISTURE INTO NC... RESULTING IN
INCREASING CLOUDS AS WE HEAD THROUGH SUNDAY. THE MID LEVEL LOW OFF
CA LATE IN THE WEEK OPENS UP AND WEAKENS THEN HEADS EASTWARD... AND
AS THIS BROAD TROUGH APPROACHES NC FROM THE WEST LATE SUN THROUGH
MON... EXPECT A TREND TO MOSTLY CLOUDY SKIES AND A CHANCE OF RAIN AS
THE OLD FRONT HEADS NORTHWARD TOWARD NC AS A WARM FRONT. EXPECT A
GRADUAL RECOVERY IN TEMPS THROUGH THIS PERIOD... STAYING BELOW
NORMAL HOWEVER. HIGHS IN THE 40S TO NEAR 50 FRI/SAT... CLIMBING TO
THE 50S TO NEAR 60 FOR SUN/MON. -GIH
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 115 AM TUESDAY...
24 HOUR TAF PERIOD:
THE MOST TREACHEROUS CONDITIONS FOR THE TAFS WILL BE IN THE TRIAD AS
A POTENT STORM SYSTEM MOVES IN FROM THE SOUTHWEST. NO RAIN OBSERVED
YET AT KINT AND KGSO DESPITE RADAR RETURNS ON THE 0.5 DEGREE
ELEVATION ANGLE. THIS IS OWING TO VERY DRY AIR IN THE LOWER LEVELS
WHICH WILL TAKE A WHILE TO OVERCOME BEFORE PRECIPITATION BEGINS IN
THE TRIAD. AS EVAPORATIVE COOLING OCCURS IN THE LOW LEVELS
TEMPERATURES WILL COOL TO NEAR FREEZING AND A PERIOD OF FREEZING
RAIN IS POSSIBLE AT KINT AND KGSO BEGINNING AROUND 9Z THROUGH 14Z OR
SO BEFORE WARM AIR ADVECTION CAUSES TEMPERATURES TO RECOVER. AT THIS
TIME FREEZING RAIN IS EXPECTED TO GIVE WAY TO AN EXTENDED PERIOD OF
LIGHT TO MODERATE RAIN...WITH POCKETS OF HEAVIER PRECIPITATION
THROUGH THE END OF THE TAF PERIOD. ALREADY MVFR CONDITIONS IN THE
TRIAD ARE EXPECTED TO FURTHER DETERIORATE TO IFR/LIFR AND MOST
LIKELY WILL REMAIN IN THE TANK THROUGH THE PERIOD WITH CEILINGS LESS
THAN 1000 FEET AND VISIBILITIES MAINLY IN THE MVFR RANGE.
CONDITIONS AT THE REMAINING TAF SITES WILL BE SIMILAR BUT WITHOUT
THE PERIOD OF FREEZING RAIN AT THE ONSET AS TEMPERATURES ARE
EXPECTED TO REMAIN ABOVE FREEZING THROUGH THE PERIOD. ANOTHER
CONCERN AT ALL TAF LOCATIONS WILL BE LOW LEVEL WIND SHEAR THAT IS
EXPECTED TO PICK UP JUST AFTER SUNRISE...NEAR 14Z. LIGHT EAST OR
NORTHEASTERLY WINDS IN THE LOW LEVELS WILL RAPIDLY INCREASE TO 35 TO
40 KNOTS OUT OF THE SOUTHEAST NEAR 2 KFT. WHILE THE SEVERITY OF THE
LLWS WILL DECREASE AFTER 00Z WEDNESDAY...LLWS WILL STILL BE A
CONCERN THROUGH THE END OF THE TAF PERIOD WITH THE EXCEPTION OF KRWI
WHERE THE THREAT WILL END EARLIER AS SURFACE WINDS SHOULD BE
STRONGER AND NEAR UNIDIRECTIONAL TO HELP MITIGATE SHEAR POTENTIAL.
LONG TERM: A SECOND STORM SYSTEM WILL FOLLOW RIGHT BEHIND THE FIRST
WHICH WILL CARRY INTO WEDNESDAY BEFORE CLEARING OUT WEDNESDAY NIGHT.
CONDITIONS SHOULD BE PREDOMINATELY VFR THEREAFTER UNTIL EARLY NEXT
WEEK WHEN THE NEXT SYSTEM APPROACHES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 2 AM TO NOON EST TUESDAY FOR NCZ007-
021>024-038-039.
&&
$$
SYNOPSIS...WSS
NEAR TERM...BSD
SHORT TERM...WSS
LONG TERM...HARTFIELD
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1240 AM CST TUE NOV 26 2013
.UPDATE...
ISSUED AT 1240 AM CST TUE NOV 26 2013
NO MAJOR UPDATES REQUIRED TO THE FORECAST FOR THE OVERNIGHT HOURS.
ADDED A MENTION OF FLURRIES WESTWARD TO INCLUDE NEARLY ALL OF
CENTRAL NORTH DAKOTA TO THE JAMES RIVER BASIN FOR THE OVERNIGHT
HOURS. MINIMUM TEMPERATURES WILL DEPEND GREATLY ON SKY COVER WITH
CLEAR SKIES ALLOWING RADIATIONAL COOLING AND CLOUD COVER KEEPING
TEMPERATURES STEADY OR PERHAPS RISING A TAD. EXPECTING VARIABLE
CLOUDINESS OVERNIGHT...AND SOME AREAS INDICATED NEARLY REACHING
THE FORECAST MIN TEMPERATURES IN CLEAR SKIES. LOWERED MIN TEMPS
JUST A TAD TO ACCOUNT FOR PATCHY CLOUDS/CLEARING.
UPDATE ISSUED AT 958 PM CST MON NOV 25 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ONLY
ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 707 PM CST MON NOV 25 2013
LOW CLOUDS WILL CONTINUE PRIMARILY ALONG AND EAST OF THE MISSOURI
RIVER TONIGHT. FURTHERMORE...BOUNDARY LAYER WINDS ARE
FORECAST TO REMAIN AROUND 30 KNOTS EAST OF HIGHWAY 83 THROUGH 12Z
TUESDAY. GIVEN THE COMBINATION OF LOW CLOUDS AND TURBULENT
BOUNDARY LAYER FLOW...ADJUSTED OVERNIGHT LOWS UP BY TWO
CATEGORIES...MAINLY EAST OF HIGHWAY 83. HIGH PRESSURE NOSING INTO
WESTERN NORTH DAKOTA WILL LIKELY CLEAR OUT THE CLOUDS WEST AFTER
MIDNIGHT AND ALLOW TEMPERATURES TO RADIATE INTO THE SINGLE DIGITS
WEST OF HIGHWAY 85 BY TUESDAY MORNING.
THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE UPDATED
PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
A STRONGER SURGE OF COLD AIR ADVECTION WILL PUSH SOUTH INTO NORTH
DAKOTA OVERNIGHT. AFTERNOON OBS AND REFLECTIVITY NEAR ROLLA...AND
LIGHT QPF SCATTERED ALONG THE EASTERN FRINGES OF THE FORECAST AREA
IN SOME SHORT RANGE MODELS...HAVE PROMPTED INCLUSION OF FLURRIES
FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY TONIGHT.
A FEW AFTERNOON OBS AT MINOT AND TIOGA...SUGGESTIVE OF FREEZING
DRIZZLE/UNKNOWN PRECIP...ARE ACTUALLY THE RESULT OF EXISTING SNOW
BEING BLOWN NEAR THE WEATHER SENSOR.
HAVE INCREASED OVERNIGHT CLOUD COVER BASED ON AFTERNOON TRENDS AND
ROBUST LOW LEVEL RH EVIDENT ON THE RAP MODEL. LOWS SHOULD BE IN THE
SINGLE DIGITS TO AROUND 10 DEGREES SOUTH. TUESDAY WILL BE THE
COLDEST DAY OF THE COMING WEEK...WITH HIGHS IN THE TEENS TO LOWER
20S SOUTHWEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
LATEST EXTENDED SUITE CONTINUES TO SHOW AN ACTIVE PERIOD IN TERMS
OF SUCCESSIVE DRY FRONTAL SYSTEMS SLIDING THROUGH. THE NEXT
POTENTIALLY SIGNIFICANT SYSTEM MAY OCCUR MONDAY AND BEYOND.
A PROGRESSIVE PATTERN BEGINS THE LONG TERM WITH A WAVERING
BAROCLINIC ZONE SHIFTING FROM WEST TO EAST TUESDAY NIGHT AS WARM AIR
ADVECTION COMMENCES. A WEAK COLD FRONT FOLLOWS FOR WEDNESDAY/
WEDNESDAY NIGHT WITH A RETURN TO COLD AIR ADVECTION INTO EARLY
THURSDAY. NEUTRAL ADVECTION TO WEAK WARM AIR ADVECTION RESUMES
FRIDAY INTO SATURDAY. THE ONLY SUFFICIENT LIFT FOR MEASURABLE
PRECIPITATION DURING THIS TIME WOULD BE CONFINED TO THE TURTLE
MOUNTAINS WEDNESDAY AND FRIDAY NIGHT. HAVE COLLABORATED WITH OUR
EASTERN OFFICE AND INCORPORATED A SLIGHT CHC OF SNOW IN THE FAR
NORTHEAST. ANY SNOW ACCUMULATION WOULD BE MINIMAL AT BEST.
THE NEXT SYSTEM TO AFFECT WESTERN AND CENTRAL NORTH DAKOTA SHOWS
SIGNS OF LIGHT PRECIPITATION BREAKING OUT VIA WARM AIR ADVECTION
PROCESSES SUNDAY AFTERNOON INTO SUNDAY NIGHT. HOWEVER IT APPEARS
THE BULK OF PRECIPITATION WOULD BE IN THE FORM OF SNOW MONDAY INTO
MONDAY NIGHT. A DRY SLOT MAY FOLLOW FOR TUESDAY. STILL A LOT OF
UNCERTAINTY THIS FAR OUT AND WILL CONTINUE TO MONITOR FUTURE
MODELS RUNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1240 AM CST TUE NOV 26 2013
MVFR CIGS WILL CONTINUE GENERALLY ALONG AND EAST OF A LINE FROM
KISN-KBIS TONIGHT. CONDITIONS WILL GRADUALLY IMPROVE TO VFR FROM
WEST TO EAST TUESDAY MORNING. VFR CONDITIONS ARE FORECAST OVER
KISN/KDIK/KMOT/KBIS BY TUESDAY AFTERNOON...AND AT KJMS LATE
AFTERNOON. NORTHWEST WINDS WILL CONTINUE THROUGH TUESDAY
AFTERNOON...THEN BECOME LIGHT AND TURN TO THE SOUTHEAST BY/DURING
TUESDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1121 PM CST MON NOV 25 2013
.UPDATE...
06Z AVIATION DISCUSSION BELOW.
.PREVIOUS UPDATE DISCUSSION...
STRATUS SHIELD CONTS TO SLIDE SE ACROSS NERN PART OF SOUTH DAKOTA
OVERNIGHT...CREATING A DIFFICULT FORECAST FOR OVERNIGHT LOWS.
TEMPS UNDER THE CLOUD SHIELD HAVE NOT FALLEN OFF GREATLY FROM THE
AFTERNOON READINGS...WITH TEMPS AOA 30 DEGREES AND HOLDING STEADY.
FURTHER SW...CLEAR SKIES ARE ENABLING TEMPS IN THE FAR SW CWA TO
FALL...ALBEIT SLOWLY...BUT FALLING NONE THE LESS. THE PROBLEM
ARISES WHEN TRYING TO TIME THE BACK EDGE OF THE CLOUD SHIELD AS IT
HAS PUSHED INTO NRN ND ATTM WITH TEMPS ACROSS SRN CANADA IN THE
SINGLE DIGITS ABOVE ZERO. SENT OUT EARLIER UPDATE TO SLOW THE TEMP
FALL ACROSS THE CWA...AND RAISE LOWS ABOUT A CATEGORY ACROSS THE
NE. ALSO MANUALLY ADJUSTED THE HOURLY TEMP GRIDS...KEEPING TEMPS
UP THROUGH 10Z OR SO...THEN IN ANTICIPATION OF CLEARING
LINE...ALLOWED TEMPS TO FALL TO FORECAST LOWS AROUND 13Z TO 14Z.
ISOLD FLURRIES ARE STILL BEING REPORTED ACROSS ERN SECTIONS OF
ND...AND STILL SEEMS PRUDENT TO KEEP THEM IN ONGOING FCST. ALSO
TWEAKED SKY GRIDS TO BETTER MATCH CURRENT CLOUD SHIELD LOCATION
AND WINDS ARE ALSO STAYING UP JUST A BIT. UPDATED ZONE FORECAST
SENT OUT EARLIER.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
LEADING EDGE OF THE STRATUS/STRATOCUMULUS DECK IS FIRMLY IN PLACE
ACROSS THE EASTERN CWA...WITH A MASSIVE EXPANSION BACK TO THE
NORTH INTO CANADA. MAIN FORECAST ISSUES OVERNIGHT WILL BE CLOUD
COVER AND THE ONSET OF STRONGER COLD AIR ADVECTION. RUC13 900-850
MB RH HAS A VERY GOOD HANDLE ON CURRENT STRATUS OVER THE REGION SO
USED THAT AS A FORECAST FOR THE OVERNIGHT PERIOD. IT BASICALLY
SHOWS THE STRATUS SLOWLY OOZING SOUTHWEST ACROSS SOUTH DAKOTA
THROUGH 12Z TUESDAY. HAVE INCREASED SKY COVER FROM PREVIOUS
FORECAST AND MAY NEED TO BE BEEFED UP MORE FOR EVENING UPDATES.
WITH ADDITIONAL WEAK SHORTWAVE ENERGY MOVING SOUTH OVER THE AREA
LATE TONIGHT AND THE STRONGER COLD AIR ADVECTION...SEE NO REASON
WHY CLOUDS WOULD BREAK UP OR CEASE TO MOVE ANY FURTHER
SOUTH/SOUTHWEST INTO TUESDAY MORNING. LEFT IN THE MENTION OF
FLURRIES FOR THE EASTERN CWA LATE TONIGHT THROUGH TUESDAY MORNING
IN ASSOCIATION WITH THE WEAK SHORTWAVE ENERGY. CURRENT OBS ACROSS
NORTHEAST ND AND SOUTHERN CANADA SHOW -SN WITH VSBYS GENERALLY
ABOVE 6SM IN ASSOCIATION WITH THE WEAK WAVE. WITH THE ONSET OF
COLDER AIR ALOFT ON TUESDAY...WILL SEE HIGH TEMPS SEVERAL DEGREES
COLDER THAN MONDAY. READINGS WILL BE IN THE TEENS TO MID 20S
ACROSS THE CWA. SURFACE HIGH THEN MOVES THROUGH THE AREA TUESDAY
NIGHT WHICH SHOULD CLEAR THE SKIES AND PROVIDE FOR A PERIOD OF
LIGHT WINDS. ALTHOUGH THE RIDGE AXIS IS PRETTY NARROW AND A QUICK
MOVER...SO BY 12Z WEDNESDAY MUCH OF THE CWA IS ALREADY UNDER
SOUTHERLY SFC WIND FLOW. NOT AN IDEAL RADIATIONAL COOLING
SETUP...BUT WILL STILL GET PRETTY COLD NONETHELESS. WILL BE AROUND
0 DEGREES ACROSS THE EASTERN CWA WITH FAVORED COLD SPOTS PERHAPS
SNEAKING BELOW ZERO. HIGHS ON WEDNESDAY WILL REBOUND SOMEWHAT AS
925MB TEMPS BEGIN TO WARM ON THE BACKSIDE OF THE RETREATING SFC
HIGH. BREEZY WINDS WILL DEVELOP SO THERE WILL BE DECENT MIXING.
HIGHS WILL REMAIN BELOW NORMAL THOUGH AS THE OVERALL PATTERN
REMAINS COLD.
.LONG TERM...THURSDAY THROUGH SUNDAY
NORTHWEST FLOW ALOFT WILL BE THE PREDOMINATE UPPER PATTERN
THROUGH MOST OF THE LONG TERM PERIOD...BUT A PATTERN CHANGE
DOES SEEM TO BE ON THE HORIZON. A SHORTWAVE TROUGH DROPPING OUT
OF CANADA WILL INFLUENCE THE REGION FOR THE FRIDAY/SATURDAY TIME
FRAME...HOWEVER MOST OF THE FORCING APPEARS TO REMAIN NORTH OF OUR
CWA...AND MODEL MOISTURE PROFILES REMAIN FAIRLY DRY AT THIS POINT.
DECENT WARM AIR ADVECTION AHEAD OF THAT WAVE COULD CAUSE SOME
PTYPE ISSUES IF PRECIPITATION WERE TO MATERIALIZE OVER OUR CWA
SATURDAY. ALTHOUGH MODELS VARY ON THE STRENGTH OF THE WARM
PUSH...850 MB TEMPERATURES DO RISE ABOVE 0 C...WITH THE GFS
ADVERTISING AS HIGH AS 6 OR 7 C ACROSS OUR SOUTHERN CWA.
EITHER WAY...CONTINUED WITH THE DRY ALLBLEND FORECAST FOR NOW. BY
SUNDAY WEAK RIDING APPEARS TO BE OVER THE NORTHERN PLAINS...BUT
IT ONLY PRECEDES A MORE SIGNIFICANT UPPER LOW MOVING INTO THE
PACIFIC NORTHWEST.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR STRATUS DECK CONTS TO RESIDE OVER THE NERN PART OF THE
CWA...WITH KMBG/KABR/KATY ALL REPORTING OVC CONDS. LOOK FOR THE
EDGE OF THE SHIELD TO CREATE SCT-BKN CONDS FOR THE KPIR TERMINAL
BY 08Z. BACK EDGE OF CLOUD DECK LOOKS TO MOVE INTO THE NRN
TERMINAL LOCATIONS AOA 13Z...AND INTO KATY BY 15Z. GUSTY NW WINDS
WILL WILL AFFECT ALL TERMINAL LOCATIONS THROUGH 14Z BEFORE
BEGINNING TO DIMINISH. ONCE SKIES CLEAR...LOOK FOR GOOD VFR CONDS
THROUGH THE REMAINDER OF THE VALID FORECAST PERIOD.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...HINTZ
SHORT TERM...TMT
LONG TERM...SERR
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1144 PM CST MON NOV 25 2013
.AVIATION...
THE BACK EDGE OF THE LOW CLOUD DECK WAS EDGING SOUTHWARD AT 20 MPH
AND SHOULD PASS BOTH KLBB AND KCDS NEAR 08Z TONIGHT. UNTIL
THEN...KLBB WILL HAVE THE BIGGEST CHANCE OF IFR AND MAYBE EVEN
LIFR CONDITIONS WHILE KCDS APPEARS TO HAVE SLOWLY INCREASING MVFR
CEILINGS ALREADY. KLBB ALSO WILL STILL EXPERIENCE LIGHT FREEZING
DRIZZLE AND PROBABLY AT MOST A LIGHT FOG UNTIL ABOUT 08Z. THERE
STILL WILL BE A NON-ZERO RISK FOR SURFACE OBSCURATION FROM FOG
LATER TONIGHT AT KCDS MAINLY BUT TRENDS DO NOT APPEAR TO SUPPORT
THIS TO ANY AMOUNT LARGE ENOUGH FOR TAF INCLUSION. OTHERWISE...
TREND TOWARDS VFR ON TUESDAY ARE CLEAR. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 701 PM CST MON NOV 25 2013/
UPDATE...
ISSUED A WINTER WEATHER ADVISORY THROUGH THE EVENING AS AN AREA OF
LIGHT FREEZING DRIZZLE AND FOG WAS SPREADING SOUTHWARD THROUGH
MOST OF THE AREA. ALSO EXPECT FLURRIES. MOST SOLUTIONS DIMINISH
THE SHALLOW LIFT AND THIN THE NEAR-SURFACE MOIST LAYER AROUND
MIDNIGHT. RMCQUEEN
PREV DISCUSSION... /ISSUED 547 PM CST MON NOV 25 2013/
AVIATION...
A LOW STRATUS LAYER BEHIND THIS AFTERNOONS COLD FRONT WAS EDGING
SOUTHWARD TOWARDS KLBB EARLY THIS EVENING AND SHOULD MAKE IT INTO
KLBB VERY SHORTLY AFTER 00Z. LATEST RAP SOUNDINGS STEADILY LOWER
CEILING AT KLBB TO LIFR LEVELS EARLY THIS EVENING...THOUGH THE
HRRR RUN REVEALS LESS CERTAINTY. WE HAVE CONTINUED PREVIOUS IDEA
OF AN LIFR LAYER THIS EVENING INTO KLBB...AND EVEN ADDED TEMP
LIGHT FOG AND FREEZING DRIZZLE BASED ON UPSTREAM REPORTS. THERE IS
ALSO A LOW RISK OF A HARD DROP IN VISIBILITY AS THIS IS EMANATING
OFF THE HEAVY SNOW FIELD...THOUGH NOT EXPLICIT FOR KLBB IN ANY
GUIDANCE AT THE MOMENT. FOR KCDS...THE CURRENT IFR/LIFR CIG SHOULD
HOLD FOR SEVERAL HOURS BEFORE BREAKING...AT LEAST BASED ON SHORT
RANGE MODEL TRENDS. UNCERTAIN FOR KCDS IS IF FOG COULD REDEVELOP
LATER TONIGHT PER RAP SURFACE HUMIDITY PROGS. WILL STUDY FURTHER
FOR 06Z CYCLE. CONDITIONS EXPECTED TO BE ALL VFR TUESDAY. RMCQUEEN
PREV DISCUSSION... /ISSUED 300 PM CST MON NOV 25 2013/
SHORT TERM...
UPPER LEVEL LOW WHICH HELPED FEED MOISTURE IN FOR THE WEEKEND WINTER
WEATHER STORM WAS OVER THE PANHANDLE AT MID DAY. THE LOW CENTER
WILL MAKE AN INTERESTING TRAJECTORY DIGGING SOUTHWARD THIS EVENING
AND MAKING IT INTO THE TX HILL COUNTRY BY TUESDAY MORNING BEFORE
EJECTING NORTHEASTWARD AS IT PHASES WITH A MAIN STREAM DIVING
THROUGH MANITOBA THIS AFTERNOON. THIS WILL RESULT IN NORTHERLY FLOW
AND MUCH DRIER CONDITIONS SETTING IN. LOWS TONIGHT WILL BE TRICKY
AS SKIES ARE EXPECTED TO CLEAR NW TO SE AROUND SUNRISE TUESDAY
MORNING. GIVEN THE PROXIMITY OF THE UPPER LOW...WE MAY SEE A FEW
FLURRIES OVERNIGHT WINDS SHOULD REMAIN UP AROUND 10 KTS AND THOUGH
WIDESPREAD SNOWFALL REMAINS ON THE GROUND...COMBINATION OF SPEEDS
AND DOWNSLOPE TRAJECTORY SHOULD KEEP FOG THREAT TO A MINIMUM THOUGH
GIVEN THE SNOW-PACK...WILL GO AHEAD AND MENTION PATCHY FOG NORTHWEST.
SUNNY AND MUCH WARMER TUESDAY.
LONG TERM...
HIGH AMPLITUDE RIDGE IN PLACE ACROSS THE ROCKIES TO BEGIN THE
EXTENDED PERIOD TUESDAY NIGHT AND WEDNESDAY. SHOULD BE RATHER COLD
AGAIN OVER DEEPER SNOW-PACK SRN PANHANDLE WITH TEMPS AGAIN IN THE
TEENS. IF WINDS ARE LIGHT ENOUGH...COULD SEE SOME SINGLE DIGITS.
40S AREAWIDE FOR HIGHS WEDNESDAY...AND THEN 50S ON THURSDAY AS
FLAT UPPER RIDGE AXIS MOVES EAST OVER THE CENTRAL AND SOUTHERN PLAINS.
MAY BE PUSHING 55-60 DEGREES SOUTH BY FRIDAY AS SURFACE LEE TROUGH
DEEPENS FROM ERN CO INTO NERN NM AND WEST TEXAS. NEXT SYSTEM OF
INTEREST IS POS TILTED OPEN WAVE THAT WILL APPROACH THE AREA OVER
THE WEEKEND. SHOULD BEGIN TO SEE SOME MOISTURE RETURN LATE FRIDAY
AND SATURDAY AS SOUTHERLY WINDS INCREASE...LIKELY SOME LOW CLOUDS
CENTRAL AND EAST SECTIONS. GFS FOR NOW KEEPS SHOWERS EAST OF THE
AREA. MAY SEE FRONT INTO AREA ON SUNDAY. PROGRESSIVE NATURE OF
SYSTEM LIKELY MEANS A DRY FRONT...AND ONLY SLIGHT COOL-DOWN.
BOTH GFS AND PREV ECMWF ADVERTISING BIG PATTERN CHANGE WEDNESDAY OF
NEXT WEEK (DEC. 4) WITH CRASHING HEIGHTS OVER THE WESTERN CONUS. IF
SOME SEMBLANCE OF THIS PATTERN IS REALIZED...COULD TURN MUCH COLDER
AROUND THIS TIME...WITH WINTER WEATHER POSSIBLY MAKING A RETURN.
DOES BEAR WATCHING.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 14 36 17 39 23 / 10 0 0 0 0
TULIA 19 38 18 39 23 / 10 0 0 0 0
PLAINVIEW 22 41 20 44 25 / 10 0 0 0 0
LEVELLAND 21 45 20 44 25 / 10 0 0 0 0
LUBBOCK 23 45 22 48 27 / 10 0 0 0 0
DENVER CITY 23 46 23 48 25 / 10 0 0 0 0
BROWNFIELD 23 46 22 48 25 / 10 0 0 0 0
CHILDRESS 23 47 24 45 26 / 10 0 0 0 0
SPUR 26 48 22 48 27 / 10 0 0 0 0
ASPERMONT 25 49 26 48 29 / 10 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE
FOLLOWING ZONES: TXZ021>037-039>042.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1135 PM EST MON NOV 25 2013
.SYNOPSIS...
STORM SYSTEM WILL MOVE FROM THE GULF COAST TONIGHT INTO EASTERN
NC/VA BY WEDNESDAY MORNING...AND FINALLY NORTH INTO QUEBEC BY WED
NIGHT. THIS SYSTEM WILL BRING A POTPOURRI OF WEATHER THROUGH WED
NIGHT. HIGH PRESSURE ENTERS FROM THE SOUTHWEST BY THURSDAY...AND
STICKS AROUND INTO SATURDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1045 PM EST MONDAY...
QUICK UPDATE TO START THE ADVISORY RIGHT NOW OVER THE WEST SINCE
GETTING REPORTS OF SNOW ACCUMULATING ON ROADS ACROSS THE FAR SW.
LEAVING THE REMAINDER FROM ALONG THE BLUE RIDGE EAST STARTING AT 2
AM.
AS OF 825 PM EST MONDAY...
MID/LOW LEVEL DRY AIR PER EVENING SOUNDINGS AND LATEST OBS HAS
CONTINUED TO KEEP PRECIP FARTHER TO THE WEST THIS EVENING WITH
MOST PRECIP ON RADAR ALOFT AND JUST GOING TO SLOWLY MOISTEN THE
COLUMN ATTM. IN ADDITION THE LOW LEVEL FLOW REMAINS RATHER WEAK
AND SW JUST ABOVE THE SURFACE MAKING FOR LIMITED ISENTROPIC LIFT
AS THE BEST JET SUPPORT INCLUDING AXIS OF HIGHER DEWPOINTS LINGERS
ACROSS THE TN VALLEY. BOTH THE LATEST RAP AND HRRR HAVE DELAYED
THE ONSET OF SIGNIFICANT PRECIP UNTIL AFTER MIDNIGHT FOR THE MOST
PART WEST AND UNTIL THE EARLY MORNING HOURS OUT EAST. SINCE THIS
LOOKS IN LINE WITH THE LATEST TRENDS...HAVE DELAYED ONSET OF POPS
ACROSS THE REGION FOR COUPLE HOURS BEFORE THINGS REALLY MOISTEN
AND PRECIP QUICKLY INCREASES ESPCLY BLUE RIDGE AND ACROSS THE
SOUTH AFTER MIDNIGHT. EVENING RAOBS AND SURFACE OBS INDICATE STILL
LOTS OF ROOM FOR WET BULB COOLING ALTHOUGH TREND OUT WEST HAS BEEN
FOR DEWPOINTS TO RISE WITHOUT MUCH COOLING AS PRECIP EVAPORATES
BEFORE REACHING THE SURFACE. THIS SUPPORTS KEEPING A MIXED BAG BUT
A LITTLE MORE SNOW WEST AT THE ONSET WITH SOME CHANCE OF
SNOW/SLEET EAST THEN MOSTLY FZRA/SLEET. ADJUSTED TEMPS DOWN SOME
FOR CURRENT READINGS WITH MOST LIKELY NOT DROPPING TOO MUCH MORE
UNTIL HEAVIER PRECIP ARRIVES.
MAIN ADJUST TO HEADLINES WAS TO EXTEND THE GOING ADVISORY LONGER
INTO THE AFTERNOON ON TUESDAY FOR AMHERST/BOTETOURT COUNTIES
GIVEN FORECAST SOUNDINGS SHOWING TEMPS UNABLE TO GET MUCH ABOVE
FREEZING UNTIL LATE IN THE DAY. THIS MAY ALSO BE THE CASE ON THE
NORTH SIDE OF HIGHWAY 460 IN ROANOKE AND MONTGOMERY COUNTIES BUT
HELD THOSE AREAS AT A NOON EXPIRATION FOR NOW GIVEN POTENTIAL FOR
THAT AREA TO SEE WARMING FROM HEAVIER RAINFALL THROUGH THE WARM
LAYER SOONER.
PREVIOUS DISCUSSION AS OF 250 PM EST MONDAY...
DURING THIS TIME PERIOD WILL BE DEALING WITH NUISANCE WINTER WX
WHERE PRECIP ARRIVES INTO THE NC MTNS/FAR SW VA BEFORE MIDNIGHT
OVERSPREADING THE REGION BY DAWN. SUNSHINE CAME OUT TODAY OVER MOST
OF THE AREA ALLOWING TEMPS TO CLIMB ABOVE FREEZING AND AROUND 40 IN
SOUTHSIDE VA/FAR SW VA. DEWPOINTS HOWEVER ARE TANKED IN THE SINGLE
DIGITS. HENCE LIES THE PROBLEM TONIGHT. UPSTREAM CLOUDS ALREADY
POURING BACK IN AND THIS MAY HELP IN TERMS OF NOT ALLOWING TEMPS TO
DROP TOO FAR AFTER SUNSET AS CLOUDS ACT AS A BLANKET. THEN...AS THE
PRECIP ARRIVES...GIVEN THE DRY AIR IT MAY TAKE AN HOUR OR TWO TO
SATURATE THE LOW LVLS BUT ONCE IT DOES...THE TEMP/DEWPOINT PROFILE
WILL HEAD TOWARD CRITICAL LEVELS FOR WINTER PRECIP. AT THE ONSET THE
TEMPS SHOULD BE COLD ENOUGH FOR SLEET OR SNOW THEN CHANGE QUICKLY TO
FREEZING RAIN AS STRONG SOUTH TO SOUTHWEST FLOW BRINGS A WARM NOSE
INTO THE MTNS AFTER MIDNIGHT AND REACHING OUR NRN CWA BY MID
MORNING. WITH INSITU WEDGE AND SFC WET BULBING TO AT OR BELOW ZERO
WITH WARM NOSE...FREEZING RAIN WILL BECOME AN ISSUE. GROUND HAS
TURNED COLDER AS EVIDENCE BY SOIL TEMPS IN THE LOWER TO MID 30S.
THERE WILL BE A LIGHT ACCUMULATION OF SLEET OR SNOW AT THE
ONSET...LESS THAN AN INCH...THEN QUICKLY CHANGING TO FZRA WITH
GLAZING EXPECTED ALONG TREE/POWERLINES AND METAL OBJECTS FIRST THEN
BRIDGES/OVERPASSES. BASED ON RAINFALL RATE AND WARM AIR ALOFT THE
ACCRETION OF ICE WILL BE IN A 2-4 HOUR WINDOW AS THE BETTER LIFT
TAKES PLACE AFTER 12Z...ALLOWING THE RATES TO INCREASE AND DRAG DOWN
WARMER AIR. MODERATE TO HEAVIER RAINFALL USUALLY DOES NOT STICK TO
ROADS VERY WELL WHEN SFC TEMPS ARE EXPECTED TO BE NEAR FREEZING.
NEED MORE LIKE MID TO UPPER 20S OR LOWER.
STILL THERE SEEMS TO BE ENOUGH EVIDENCE THAT MOST OF OUR CWA WILL
GET AT LEAST A TRACE OF ICE WITH HIGHER AMOUNTS ALONG THE BLUE RIDGE
FROM BOONE/BLOWING ROCK NORTH TO BUENA VISTA/AMHERST. ALSO THE
ALLEGHANY HIGHLAND SHOULD SEE UP TO 2/10S. IT ONLY TAKES A TRACE OF
ICE TO CAUSE TRAVEL PROBLEMS. BASED ON THIS AND COLLABORATION WITH
SURROUNDING NWS OFFICES...WE HAVE A WINTER WX ADVISORY OUT FOR THE
ENTIRE CWA FOR TONIGHT-MIDDAY/AFTERNOON TUESDAY...ENDING EARLIER
IN THE SOUTH.
TEMPS THIS EVENING WILL START FALLING SLOWLY THEN DROP A LITTLE MORE
ONCE PRECIP ARRIVES ALOFT LEADING TO EVAP COOLING. LOOKING AT LOWS
FROM THE UPPER 20S TO AROUND 30...THEN WARMING GRADUALLY TO ABOVE
FREEZING DURING THE DAY TUESDAY...FIRST IN THE FAR SW VA/SRN WV AREA
OUTSIDE THE WEDGE AND INTO WRN NC MTNS ALONG THE TN BORDER...THEN
SOUTHSIDE VA/NW NC PIEDMONT EXPANDING NORTHWARD BY AFTERNOON TO THE
NRN BLUE RIDGE. COULD BE A DEAL WHERE SOME VALLEYS ACROSS
BATH/ROCKBRIDGE/AMHERST TAKE INTO TUE EVENING...BUT THINK THE WARMER
RAIN AND HIGHER RATES TO BRING IT UP. FOR MOST OF US...THE ICE WILL
BE MELTED AND GONE BY MIDDAY/EARLY AFTERNOON WITH HIGHS EXPECTED TO
BE IN THE MID TO UPPER 30S SOUTH...TO LOWER 30S NORTH. BUT WILL BE
DEALING WITH MODERATE TO HEAVY AT TIMES COLD NOVEMBER RAINS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 340 PM EST MONDAY...
GFS AND ECMWF ARE IN GOOD AGREEMENT WITH THE NORTHERN AND SOUTHERN
BEGINNING TO PHASE TUESDAY NIGHT AND BECOME ONE SYSTEM WEDNESDAY.
THE UPPER LEVEL LOW TRACKING ALONG THE GULF COAST WILL OPEN OVER THE
TENNESSEE VALLEY AND MERGE WITH THE NORTHERN STREAM TROUGH ENTERING
THE OHIO VALLEY BY WEDNESDAY MORNING. THE SURFACE LOW PRESSURE OVER
GEORGIA ON TUESDAY EVENING WILL TRACK NORTHEAST ALONG THE LEE SIDE
OF THE APPALACHIAN MOUNTAINS EARLY WEDNESDAY MORNING. AS THE
NORTHERN STREAM TROUGH BECOMES DOMINATE...A SECONDARY SURFACE LOW IS
EXPECTED TO DEVELOP OVER THE VIRGINIA PIEDMONT TUESDAY NIGHT...THEN
LIFT TO NEW ENGLAND ON WEDNESDAY. BY WEDNESDAY EVENING...THE SFC LOW
WILL BE LOCATED OVER MAINE WITH TRAILING COLD FRONT PUSHING INTO THE
ATLANTIC OCEAN. HIGH PRESSURE WILL BE BUILDING ACROSS OUR REGION
WEDNESDAY NIGHT INTO THURSDAY.
THE RAIN MAY BE HEAVY AT TIMES TUESDAY AFTERNOON INTO WEDNESDAY
MORNING. JET DYNAMICS AND LIFT ASSOCIATED WITH PASSING SURFACE AND
SHORTWAVES WILL BRING HIGH RAINFALL RATES TO THE AREA. COLDER AIR
WILL PUSH INTO OUR REGION TUESDAY NIGHT INTO WEDNESDAY MORNING. RAIN
WILL TRANSITION TO SNOW STARTING ALONG THE HIGHER ELEVATION THEN
ACROSS THE REST ON WEDNESDAY. MOISTURE WILL PULL OUT OF MOST OF THE
AREA WEDNESDAY EVENING INTO WEDNESDAY NIGHT. NORTHWEST UPSLOPE SNOW
SHOWERS AND SNOW FLURRIES WILL CONTINUE INTO WEDNESDAY NIGHT INTO
THURSDAY. POTENTIAL STORM TOTAL SNOW FOR THE MOUNTAINS WILL LIKELY
RANGE FROM 1-4 INCHES TUESDAY NIGHT INTO WEDNESDAY...WITH UPWARDS OF
4 TO 6 INCHES ON WESTERN SLOPES TUESDAY NIGHT INTO WEDNESDAY NIGHT.
LIGHTER AMOUNTS OF SNOW EXPECTED GENERALLY LESS THAN INCH IN THE
EAST. INCREASING WINDS WILL ACCOMPANY THE UPSLOPE SNOW SHOWERS.
STRONG PRESSURE RISES AND COLD AIR ADVECTION ALONG WITH A 45-55KT
CROSS BARRIER JET WILL BRING SUSTAIN WINDS OF 20-30 MPH GUSTING TO
AROUND 50 MPH FOR COUNTIES ALONG THE BLUE RIDGE...PARTICULARLY THE
NORTH CAROLINA HIGH COUNTY AND GRAYSON HIGHLANDS. WIND SPEED WILL BE
CLOSE TO ADVISORY LEVELS. WILL HOLD OFF ON ISSUING HEADLINES FOR
SNOW AND WINDS FOR NOW TO AVOID CONFUSION WITH ONGOING EVENT. ONE
SET OF HEADLINES WILL BE REPLACED BY ANOTHER SET EVERY 6-12 HOURS.
PLAN TO HIGHLIGHT THE POTENTIAL IN HWO. AS THIS SYSTEM DEVELOPS AND
MATURES OVER THE REGION...EVERYONE SHOULD BE PREPARED FOR RAPIDLY
CHANGING CONDITIONS...ESPECIALLY IF YOU ARE TRAVELING ALONG THE EAST
COAST THIS WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 1245 PM EDT MONDAY...
LARGE SCALE PATTERN TRANSITIONS TO ZONAL FLOW WITH SURFACE HIGH
PRESSURE IN CONTROL THROUGH THE WEEKEND. THIS RESULTS IN SLOWLY
MODERATING TEMPERATURES...YET SHOULD REMAIN BELOW SEASONABLE
AVERAGES EVEN BY SUNDAY. ALSO THINKING HIGHER CLOUDS WILL BECOME
MORE PREVALENT BY SUNDAY WHICH WOULD KEEP HIGHS DOWN SOMEWHAT. LONG
TERM MODELS GENERALLY IN AGREEMENT THAT NEXT WEATHER SYSTEM WILL
MATERIALIZE IN THE SOUTHERN PLAINS LATE SUNDAY AND THEN QUICKLY
APPROACHING THE SOUTHERN APPALACHIANS FROM THE SOUTHWEST ON MONDAY.
RIGHT NOW THE 00Z ECWMF IS A LITTLE FASTER THAN THE 12Z GFS AND
GIVEN THE GENERALLY ZONAL FLOW PATTERN THIS FASTER IDEA IS
FAVORED...ESPECIALLY AS A STRONGER SYSTEM DIGS INTO THE WESTERN U.S.
AND EJECTS THIS WAVE OUT ACROSS THE PLAINS AND TOWARDS THE
APPALACHIANS. THE HIGH PRESSURE WILL BE WEAKENING AND RETREATING AS
THIS SYSTEM APPROACHES BY EARLY MONDAY BUT AIRMASS APPEARS THAT IT
WILL MODERATE ENOUGH SO THAT PRECIP TYPE REMAINS JUST RAIN. HOWEVER
IT WILL BE WORTH KEEPING AN EYE ON THE TIMING OF PRECIP ARRIVAL AND
STRENGTH OF LINGERING HIGH...AS WELL AS HOW LOW INITIAL WET BULB
TEMPERATURES ARE WHEN PRECIP ARRIVES. CANT RULE OUT SOME POCKETS OF
FREEZING RAIN IF THIS COMES IN OVERNIGHT...BUT AT THIS POINT STILL A
LONG WAY OFF.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
AS OF 1130 PM EST MONDAY...
BAND OF MIXED SNOW AND SLEET CONTINUES TO PUSH EAST TOWARD THE
BLUE RIDGE AND SHOULD BRING SOME -SN TO KBCB/ROA OVER THE NEXT HOUR
OR TWO BEFORE COVERAGE BRIEFLY FADES. THIS WILL RESULT IN LOWERING
CIGS TO MVFR OVER THE WEST BEFORE MORE SIGNIFICANT MIXED PRECIP
ARRIVES WELL AFTER MIDNIGHT. THUS LOOKING AT DETERIORATING FLYING
WEATHER AS THE NIGHT WEARS ON WITH WIDESPREAD LOW CIGS AND AT
LEAST MVFR VSBYS OVER THE WEST BY DAYBREAK TUESDAY WHEN PRECIP
SHOULD TAKE THE FORM OF FREEZING RAIN. FARTHER EAST EXPECTING LYH
TO START AS FZRA WITH PERHAPS A BIT OF SN/PL WITH THE INITIAL
BATCH. DAN WILL BE BORDERLINE ON FZRA BUT TEMPS SHOULD BE HUGGING
32-33F AT THE SFC SO INCLUDED A HOUR OR TWO OF -FZRA THERE EARLY
TUESDAY. WARM NOSE ALOFT TO CHANGE FZRA TO RAIN AT ALL SITES
AROUND MIDDAY TUESDAY ALTHOUGH SPOTS LIKE KLWB/KLYH MAY KEEP -FZRA
INTO MID OR LATE AFTERNOON. RAIN BECOMES HEAVY AT TIMES TUESDAY
AFTERNOON ESPECIALLY AT BCB/ROA/LYH/DAN. WILL EXPECT TO SEE
FLUCTUATIONS IN CIGS/VSBYS BASED ON RAINFALL RATES BUT OVERALL
SHOULD BE IFR TO LIFR WITH MOUNTAIN OBSCURATIONS LIKELY. WITH THE
STRONG SE FLOW ABOVE THE SURFACE WILL ALSO BE SEEING LLWS
POTENTIAL AT ALL LOCATIONS THROUGH THE DAY TUESDAY AS LATEST
SOUNDINGS INDICATE 35-45 KTS JUST ABOVE THE SURFACE ESPCLY IN THE
AFTERNOON. THEREFORE INCLUDED LLWS AT MOST SPOTS FOR STRONG SOUTH
TO SE FLOW DEVELOPING RIGHT AFTER SUNRISE ON TUESDAY.
MODERATE TO HEAVY RAINFALL CONTINUES TUESDAY NIGHT WITH LOCATIONS
ACROSS SE WVA TRANSITIONING BACK TO SNOW BY EARLY WEDNESDAY. THIS
WILL KEEP LOW IFR/LIFR CIGS AND MVFR TO IFR VSBYS GOING TUESDAY
NIGHT AS THE CORE OF THE LOW PRESSURE SYSTEM TRACKS ACROSS THE
AREA.
RAIN CHANGES TO A SIGNIFICANT UPSLOPE EVENT BY WED WITH PERHAPS A
TRAILING DEFORMATION BAND OF SNOW WORKING EAST TOWARD THE BLUE
RIDGE WED MORNING. THIS MAY RESULT IN A FEW INCHES OF SNOW
ACCUMULATION AROUND KBLF/KLWB AND POSSIBLY A LIGHT AMOUNT EAST TO
KBCB. WIND WILL ALSO BECOME AN ISSUE ACROSS THE MOUNTAINS WITH NW
WIND GUSTS TO 45 KTS OR MORE WED WITH A SIGNIFICANT COASTAL LOW
MOVING ACROSS COASTAL NEW ENGLAND.
RAPID IMPROVEMENT WILL OCCUR ON THURSDAY AS THE STORM SYSTEM
PULLS AWAY AND DRIER AIR WORKS IN...RESULTING IN WIDESPREAD VFR
CONDITIONS. VFR THEN CONTINUES UNDER HIGH PRESSURE FOR FRIDAY
THROUGH SATURDAY.
&&
.HYDROLOGY...
AS OF NOON EST MONDAY...
MODEL CONSENSUS AND HPC GUIDANCE GENERALLY IN THE 2 TO 3 INCH RANGE
OF LIQUID QPF FOR THE IMPENDING STORM EVENT ALTHOUGH SOME SREF
ENSEMBLE MEMBERS SHOWING OVER 4 INCHES BY ABOUT 12Z WEDNESDAY THE
27TH. QUESTION IS WHAT IMPACT THE RUNOFF FROM THIS WILL HAVE ON AREA
STREAMS AND RIVERS. POINT ONE IS THAT RIVERS ARE STARTING OFF AT
VERY LOW LEVELS ESPECIALLY ACROSS THE LOWER PORTIONS OF OUR RIVER
BASINS...ACROSS THE PIEDMONT. USGS DAILY STREAMFLOW PERCENTILES AS
OF THIS MORNING ARE SHOWING NEARLY ALL PIEDMONT RIVER AND STREAM
LOCATIONS RUNNING AT FLOWS BELOW THE 25TH PERCENTILE FOR THE DATE
AND SOME BELOW THE 10TH PERCENTILE. THIS ALSO HOLDS TRUE FOR MUCH OF
THE UPPER JAMES RIVER BASIN. 60-DAY RAINFALL DEFICITS HAVE BECOME
QUITE SIGNIFICANT...REACHING 4 TO 6 INCHES IN MANY OF THESE BASINS
OR AROUND 25 PERCENT OF NORMAL. DETERMINISTIC RIVER FORECASTS ISSUED
THIS MORNING BY THE FOUR RFCS SERVING THE BLACKSBURG HYDRO SERVICE
AREA INCLUDE 48 HOURS OF QPF THROUGH 12Z WEDNESDAY OF GENERALLY 2 TO
2.5 INCHES. AT OF THIS PACKAGE NO RIVERS ARE FORECAST TO REACH FLOOD
STAGE OR EVEN ACTION STAGE (GENERALLY A FEW FEET BELOW FLOOD STAGE)
ALTHOUGH SEVERAL COME CLOSE...INCLUDING THE NORTH FORK HOLSTON RIVER
AT SALTVILLE AND GREENBRIER RIVER AT ALDERSON. THAT SAID HYDROLOGIC
MODELS TEND TO HAVE SOME DIFFICULTY AFTER EXTENDED DRY PERIODS IN
HANDLING RUNOFF WHICH IS GENERALLY MUCH MORE EFFICIENT IN THE COOL
SEASON. HENCE...THE RESPONSE ON RIVERS REMAINS SOMEWHAT UNCERTAIN
BUT NOT ENOUGH CONFIDENCE TO ISSUE A FLOOD WATCH. NOT EXPECTING MUCH
IF ANY CONVECTION WITH THIS STORM SO RAINFALL RATES SHOULD REMAIN
MODEST..IN THE 0.10 TO 0.25 INCH PER HOUR RANGE. BUT HIGHER RAINFALL
RATES IN ANY ELEVATED STORMS THAT ARE ABLE TO DEVELOP COULD LEAD TO
LOCALIZED RUNOFF PROBLEMS. THESE COULD BE HANDLED WITH SHORT-FUSE
HYDROLOGIC PRODUCTS..FLOOD ADVISORIES OR EVEN FLASH FLOOD WARNINGS
BUT THE LIKELIHOOD AT THIS POINT IS QUITE LOW FOR THIS TO OCCUR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR VAZ018>020-
023-024-035.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ007-
009>017.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR VAZ022-
032>034-043>047-058-059.
NC...WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR NCZ001-002-
018.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR NCZ003>006-
019-020.
WV...WINTER WEATHER ADVISORY UNTIL 4 PM EST TUESDAY FOR WVZ045.
WINTER WEATHER ADVISORY UNTIL NOON EST TUESDAY FOR WVZ042>044.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...JH/WP
SHORT TERM...KK
LONG TERM...SK
AVIATION...JH/RAB/WP
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
925 AM EST TUE NOV 26 2013
...ISOLATED SEVERE WEATHER POSSIBLE THIS EVENING AND OVERNIGHT...
.UPDATE (REST OF TODAY THROUGH WEDNESDAY MORNING)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN AMPLIFIED AND HIGHLY
ENERGETIC UPPER LEVEL PATTERN EVOLVING ACROSS THE CONUS. FLOW RIDGES
SHARPLY OVER THE PACIFIC COAST AND INTER-MOUNTAIN WEST BEFORE DIVING
BACK SOUTH INTO DEEP LONGWAVE TROUGHING COVERING THE REMAINDER OF
THE NATION. THIS LONGWAVE TROUGH IS RATHER COMPLEX WITH BOTH A
STRONG NORTHERN STREAM AND SOUTHERN STREAM IMPULSE EMBEDDED WITHIN.
THE NORTHERN STREAM ENERGY IS DROPPING QUICKLY SOUTHEASTWARD OVER
THE UPPER MIDWEST/GREAT LAKES WHILE THE SOUTHERN STREAM IMPULSE IS
CURRENTLY EJECTING EASTWARD OVER THE WESTERN GULF OF MEXICO FROM THE
SOUTHERN PLAINS.
IT IS THIS POTENT SOUTHERN STREAM IMPULSE WHICH WILL BE THE BIG
PLAYER IN OUR WEATHER OVER THE NEXT 24 HOURS AS IT SWINGS EASTWARD
ALONG THE NORTHERN GULF COAST.
CURRENTLY AT THE SURFACE...THE FLORIDA PENINSULA RESIDES WITH A ZONE
OF MODERATE SOUTHEASTERLY FLOW TO THE SOUTH OF A EAST-WEST ORIENTED
WARM FRONT ALIGNED NEAR THE I-10 CORRIDOR. THIS WARM FRONT TRAILS
BACK TO AN AREA OF LOW PRESSURE NEAR AL COAST. FROM THIS LOW...A
COLD FRONT TRAILS SOUTHWARD ACROSS THE CENTRAL GULF OF MEXICO AND
WILL MOVE QUICKLY EASTWARD TO CROSS OUR FORECAST AREA TONIGHT.
REGIONAL RADARS SHOWING WIDESPREAD SHOWERS/RAIN ASSOCIATED WITH THE
UPGLIDE OVER THE WARM FRONT LIFTING QUICKLY NORTHWARD. MUCH OF THE
FORECAST AREA IS NOW LEFT IN A ZONE OF WEAKER LIFT AS WE AWAIT THE
SYNOPTIC FORCING ASSOCIATED WITH THE APPROACHING IMPULSE/TROUGH
LATER TODAY AND TONIGHT. THEREFORE...FOR A MAJORITY OF THE DAY...THE
SHOWER ACTIVITY WILL BE MORE SCATTERED "OFF AND ON" TYPE OF REGIME
AS OPPOSED TO THE STEADIER PRECIP THAT THE CENTRAL AND NORTHERN
ZONES SAW EARLIER IN THE MORNING. SKIES ARE MOSTLY CLOUDY TO CLOUDY
REGION-WIDE AND ZONES FROM TAMPA NORTHWARD ARE LIKELY TO REMAIN
MOSTLY CLOUDY THROUGH THE DAY. FARTHER SOUTH FROM THE WARM FRONT
OVER OUR SOUTHERN ZONES...WILL NOT BE SURPRISED TO SEE AT LEAST SOME
SUNNY BREAKS EVENTUALLY DEVELOP. ALTHOUGH...THE ADDED INSTABILITY
FROM ANY INSOLATION WOULD LIKELY RESULT IN MORE SCATTERED SHOWERS.
THE POTENTIALLY MORE SIGNIFICANT WEATHER WILL BEGIN TO APPROACH
FROM THE EASTERN GULF OF MEXICO LATE THIS AFTERNOON/EARLY EVENING.
AS WE HEAD THROUGH THE LATER AFTERNOON AND ESPECIALLY THE EVENING
HOURS...LARGE SCALE FORCING FOR ASCENT ASSOCIATED WITH DCVA/HEIGHT
FALLS WILL OVERSPREAD THE AREA. GFS/ECMWF BOTH SHOW A BROAD EXPANSE
OF DEEP LAYER QG FORCING IN PLACE THIS EVENING. THIS IS ONE OF THE
MORE POTENT MID/UPPER LEVEL IMPULSES THAT WE HAVE SEEN MOVE ACROSS
THE NE GULF IN SOME TIME. UPPER LEVEL PV ANOMALY ASSOCIATED WITH
THIS IMPULSE IS VERY IMPRESSIVE WITH THE DYNAMIC TROPOPAUSE FOLDED
DOWN ALMOST TO 600MB RESULTING IN AN EQUALLY IMPRESSIVE MID/UPPER
LEVEL JET STRUCTURE. SURFACE LOW REFLECTION AS A RESULT SHOULD
CONTINUE TO DEEPEN THROUGH THE DAY/EVENING AHEAD OF THIS FEATURE AS
IT CROSSES INTO SOUTHERN GA. THE COLD FRONT WILL ALSO
INTENSIFY/SHARPEN WITH TIME ADDING A LOWER LEVEL CONVERGENCE FOCUS.
ALL THAT BEING SAID...WOULD EXPECT MOST (IF NOT ALL) LOCATIONS TO
SEE A SECONDARY ROUND OR 2 OF SHOWERS/STORMS BEGINNING LATE THIS
AFTERNOON INTO THE EVENING AND THEN ENDING QUICKLY FROM WEST TO
EAST DURING THE OVERNIGHT AS THE COLD FRONT SWEEPS ACROSS. RAIN
CHANCES ARE CATEGORICAL 80% OR HIGHER FOR JUST ABOUT ALL ZONES THIS
EVENING/OVERNIGHT...BUT TAPER QUICKLY AFTER 2AM...AND HAVE REMOVED
ALL RAIN CHANCES (EVEN FOR OUR FAR EASTERN ZONES) BY SUNRISE
TOMORROW MORNING. THE CONVECTIVE START AND END TIMES AGREE WELL WITH
THE ENSEMBLE SUITE OF LOCAL/NATIONAL HIGH RESOLUTION MODELS AND ALSO
THE HOPWRF ENSEMBLES BEING RUN OVER THE SE CONUS TODAY.
SEVERE THREAT...DESPITE THE EXPECTED WIDESPREAD COVERAGE OF SHOWER
AND STORMS DUE TO THE FORCING...THE OVERALL SEVERE THREAT SHOULD BE
ISOLATED IN NATURE. THE STORM PREDICTION CENTER HAS OUTLOOKED MUCH
OF OUR AREA IN A SLIGHT RISK FOR SEVERE WEATHER AND AGREE WITH THIS
ASSESSMENT. DEEP LAYER 0-6KM BULK SHEAR (35-40KTS) AND MLCAPE
(250-500 J/KG) IS NOT OVERLY IMPRESSIVE FOR OUR ZONES...BUT
SUFFICIENT FOR ORGANIZED CONVECTION. MID-LEVEL LAPSE RATES ARE POOR
FOR MUCH OF THE EVENT...HOWEVER THE LACK OF OVERALL BUOYANCY COULD
BE OFFSET SOMEWHAT BY THE TENDENCY FOR THE UPDRAFTS TO ROTATE. LOW
LEVEL JET WILL BE STRONGEST 40-50KTS OVER THE NATURE COAST
ZONES...AND THEN WEAKEN WITH SOUTHWARD EXTENSION. ALL THIS BEING
SAID...THE POTENTIAL CERTAINLY EXISTS FOR ISOLATED SEVERE WEATHER.
THE MAIN THREAT WILL BE FOR DAMAGING STRAIGHT-LINE WINDS. AN
ISOLATED TORNADO IS POSSIBLE AS WELL. THE BEST SETUP FOR AN ISOLATED
TORNADO LOOKS TO EXIST OVER THE NATURE COAST ZONES WHERE THE MORE
PRONOUNCED LOW LEVEL JET EXISTS RESULTING IN 0-1KM SHEAR OF AROUND
30KTS.
UPPER SHORTWAVE TAKES ON AN INCREASINGLY NEGATIVE TILT AND ROTATES
TO THE NORTHEAST OF THE AREA DURING WEDNESDAY MORNING. RAIN WILL BE
OVER WITH THE COLD FRONT OFF TO OUR EAST BY SUNRISE. DEEP LAYER
MOISTURE WILL ALSO QUICKLY EXIT ALLOWING FOR GENERALLY CLEARING
SKIES. HOWEVER...CAA IN THE WAKE OF THE FRONT OVER THE GULF WILL
LIKELY PRODUCE SOME COLD AIR STRATOCU THAT MAY MIGRATE ONSHORE FROM
TIME TO TIME (ESPECIALLY FROM PINELLAS COUNTY SOUTHWARD). THOSE
TRAVELING FOR THE THANKSGIVING HOLIDAY ON WEDNESDAY ALONG I-4 OR
FLORIDA I-75 CORRIDORS SHOULD EXPERIENCE FAIR WEATHER WITH A GUSTY
NW WIND. HIGH TEMPERATURES WILL BE COOLER WITH MAINLY 60S FROM TAMPA
BAY NORTHWARD AND AROUND 70 FURTHER SOUTH.
&&
.AVIATION...
BKN CIGS...OCNL MVFR/IFR...WITH SHRA OR -RA THROUGH MID MORNING. AN
ADVANCING FRONTAL SYSTEM WILL BRING VCTS BEGINNING AROUND 8-20Z WITH
TSRA STARTING BETWEEN 00-04Z...WITH TEMPO MVFR/IFR EXPECTED. GUSTY
WINDS SHIFT TO WEST AND NW AS THE FRONT MOVES ACROSS TONIGHT.
&&
.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR ALL COASTAL WATERS
THROUGH WEDNESDAY EVENING...BUT THIS WILL LIKELY BE EXTENDED. SOME
AREAS COULD SEE WINDS THAT DROP BELOW ADVISORY LEVELS FOR A BRIEF
TIME...ESPECIALLY LATER THIS MORNING BETWEEN THE WARM AND COLD
FRONTAL PASSAGES...BUT THEY WILL INCREASE RAPIDLY AGAIN WITH THE
COLD FRONT OVERNIGHT INTO WEDNESDAY MORNING. BUFKIT SOUNDING
PROFILES SHOWING IMPRESSIVE LOW LEVEL LAPSE RATES OVER THE WATER
BEHIND THE FRONT WHICH WILL ALLOW FOR HIGHLY EFFICIENT MIXING OF
DOWNWARD MOMENTUM AND LIKELY AT LEAST A PERIOD OF HIGH END
ADVISORY WINDS WEDNESDAY MORNING. SEAS WILL REACH UP TO 10 FEET OR
SO OFFSHORE BY EARLY WEDNESDAY MORNING. CONDITIONS WILL IMPROVE
TOWARD THE END OF THE WEEK...BUT WE COULD STILL SEE WIND SPEEDS
CLOSE TO CAUTIONARY OR ADVISORY LEVELS THROUGH SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 81 64 68 39 / 70 100 10 10
FMY 82 69 73 44 / 50 90 10 10
GIF 79 63 69 39 / 90 90 10 10
SRQ 82 67 70 43 / 60 90 10 10
BKV 79 62 65 32 / 90 100 10 10
SPG 80 65 67 47 / 70 100 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK FROM 1 PM EST THIS AFTERNOON THROUGH
WEDNESDAY EVENING FOR CHARLOTTE-HILLSBOROUGH-LEE-
MANATEE-PINELLAS-SARASOTA.
HIGH SURF ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
WEDNESDAY FOR CHARLOTTE-HILLSBOROUGH-LEE-MANATEE-
PINELLAS-SARASOTA.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR
BONITA BEACH TO ENGLEWOOD OUT 20 NM-BONITA BEACH TO
ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS
OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-
TAMPA BAY WATERS-TARPON SPRINGS TO SUWANNEE RIVER OUT
20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO 60
NM.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
747 AM EST TUE NOV 26 2013
.SYNOPSIS...
EAST COAST BOUND LOW PRESSURE WILL SPREAD A WINTRY MIX OF
PRECIPITATION OVER THE REGION TODAY. THAT PRECIPITATION WILL
CHANGE TO ALL SNOW TONIGHT.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
CONFLUENT FLOW AS WELL AS A TIGHT BAND OF FRONTOGENESIS THAT WAS
WELL SAMPLED ON THE NAM BETWEEN 500 AND 300 MB...WHICH IS ROUGHLY
COINCIDENT WITH THE DENDRITIC GROWTH ZONE HAS RESULTED IN A BAND
OF FAIRLY STEADY SNOWFALL THAT HAS PUSHED SLOWLY FROM SOUTH TO
NORTH ALREADY THIS MORNING FROM ZANESVILLE TO WHEELING TO
PITTSBURGH TO LATROBE. AMOUNTS TO THIS POINT OUT OF THIS BAND HAVE
BEEN ROUGHLY 1.5 TO 3.5 INCHES...HOWEVER RECENT RADAR TRENDS AS
WELL AS MODEL TRENDS SUGGEST THIS BAND IS LIKELY TO STRENGTHEN AS
A WARMER PUSH OF AIR ALOFT IS SET TO ADVANCE NORTHWARD THROUGH THE
MORNING HOURS AS IT SLOWLY MEANDERS NORTHWARD. QPF AND SNOW
AMOUNTS WERE BUMPED UPWARD SUBSTANTIALLY IN THIS BAND THROUGH THE
MORNING HOURS...WITH IMPRESSIVE 20:1 RATIOS NOTED AT THE NWS
OFFICE THIS MORNING. WHILE THESE RATIOS ARE UNLIKELY TO LAST AFTER
SUN UP...IT STILL SEEMS REASONABLE TO ANTICIPATE THAT AT LEAST
10:1 WOULD PERSIST BEYOND SUNRISE.
THE REST OF THE FORECAST STILL LOOKS GOOD FOR TRANSITIONS TO
RAIN/SLEET/FREEZING RAIN IN PORTIONS OF THE AREA. THE DETAILS OF
THE RATIONALE OF THAT PORTION OF THE FORECAST ARE CONTAINED BELOW.
FRIES
PREVIOUS...
A SHORTWAVE MOVING ACROSS OHIO INTO NORTHWESTERN PENNSYLVANIA HAS
ALLOWED FOR A PRECURSOR ROUND OF SNOW IN ADVANCE OF THE MAJOR SYSTEM
ARRIVING THIS MORNING. AN INCH OF SNOW HAS FALLEN AT OUR
OFFICE...AND AREA WEBCAMS SHOW SOME LIGHT ACCUMULATIONS GENERALLY ON
GRASSY SURFACES...ALTHOUGH AREA ROADWAYS STILL APPEAR TO BE MOSTLY
WET. THIS LIGHT SNOW SHOULD CONTINUE THROUGH SUNRISE.
NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS ARE BOTH STARTING THEIR
TREK TO THE EAST...WITH THEIR INTERACTION ABOUT TO AFFECT THE ENTIRE
EAST COAST. SO FAR THE PRECIPITATION SHIELD FROM THE SOUTHERN SYSTEM
IS CONTAINED TO SOUTHERN KENTUCKY AND VIRGINIA...WITH PRECIPITATION
MOVING TO THE NORTHEAST. TRICKIEST PORTION OF THE FORECAST REMAINS
WHAT WILL HAPPEN WITH LOW LEVEL TEMPERATURE PROFILES. ENOUGH WARM
AIR IS EXPECTED TO MOVE IN ALOFT THAT A MIX OF SNOW AND FREEZING
RAIN IS POSSIBLE GENERALLY SOUTH AND EAST OF A LINE FROM ZANESVILLE
TO PITTSBURGH TO DUBOIS DURING THE DAYTIME. IN ADDITION...SURFACE
TEMPERATURES WILL BE CRITICAL...AS PRECIP MAY ACTUALLY FALL AS RAIN
FOR A SEVERAL HOUR PERIOD. LATEST RUNS OF THE RAP STILL SHOW ABOVE
FREEZING TEMPERATURES REACHING ALL THE WAY INTO INDIANA COUNTY NEAR
THE SURFACE. THE RAP CAME IN AS THE WARMEST MODEL FOR SURFACE
TEMPERATURES...BUT IT ALSO USUALLY HANDLES THESE SITUATIONS WELL.
THE HIGHER ELEVATIONS IN THE RIDGES WILL LIKELY HAVE A WINTRY MIX
THROUGH MUCH OF THIS TIME PERIOD WITH AN EXTENDED PERIOD OF FREEZING
RAIN POSSIBLE. NORTH AND WEST OF THE ZZV/PIT/DUJ LINE...SOME SLEET
MAY MIX IN BY THE AFTERNOON...BUT SNOW IS EXPECTED TO BE THE
DOMINANT PRECIPITATION TYPE.
BY EVENING THE TWO SYSTEMS ARE EXPECTED TO BE IN ENOUGH PROXIMITY TO
EACH OTHER TO DEVELOP A COUPLED JET...AND CONSEQUENTLY SHOULD BE THE
TIME PERIOD WHEN THE HIGHEST PRECIPITATION RATES OCCUR. IN THE
RIDGES...FREEZING RAIN WILL CONTINUE THROUGH THE EVENING.
TEMPERATURES WILL LIKELY STILL BE WARM ENOUGH SOUTH AND EAST OF
PITTSBURGH OUTSIDE OF THE HIGHEST ELEVATIONS TO PERSIST WITH RAIN
FOR A FEW HOURS. HOWEVER...WITH ALL SNOW FALLING TO THE WEST OF
PITTSBURGH...SNOW RATES COULD BE QUITE IMPRESSIVE DURING THE EVENING
HOURS FROM ZANESVILLE TO NEW CASTLE AND FRANKLIN. AFTER MIDNIGHT
NEARLY ALL LOCATIONS WILL CHANGEOVER TO SNOW...WITH RATES BEGINNING
TO DIMINISH SLIGHTLY. IF THE WARM LAYER ALOFT PERSISTS...WHICH
LATEST MODELS RUNS HAVE BEEN INDICATING IS POSSIBLE...FREEZING
RAIN MAY HOLD ON FOR A FEW MORE HOURS IN THE RIDGES.
ALTHOUGH ALL LOCATIONS WILL CONTINUE TO RECEIVE SNOW WEDNESDAY
MORNING...THE WIDESPREAD PRECIPITATION SHIELD WILL BE MOVING OFF TO
THE EAST. ALTHOUGH WINDS WILL INITIALLY BE OUT OF THE
NORTH-NORTHWEST...LESS FAVORABLE FOR UPSLOPE/LAKE EFFECT...WINDS
WILL BACK TO THE NORTHWEST BY THE AFTERNOON AND ALLOW THE LAKE
EFFECT MACHINE TO START UP.
ALL IN ALL...ONLY MINOR CHANGES WERE MADE TO THE FORECAST THROUGH
THIS TIME PERIOD. THE AXIS OF HEAVIEST SNOWFALL WAS PUSHED SLIGHTLY
FARTHER TO THE WEST TO ALIGN WITH DEFORMATION ZONE AND THE CHANCES
FOR FREEZING RAIN WERE HELD ONTO LONGER TONIGHT IN THE RIDGES...BUT
OTHERWISE THE INHERITED FORECAST WAS IN GOOD SHAPE. NO CHANGES WERE
NEEDED TO ANY OF THE ADVISORIES OR WARNINGS.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
UPSLOPE AND LAKE EFFECT SNOW WILL CONTINUE WEDNESDAY NIGHT. MODELS
ARE SUGGESTING THAT A DOUBLE LAKE CONNECTION BETWEEN HURON-ERIE IS
POSSIBLE...WHICH COULD RESULT IN SOME LOCALLY HIGHER TOTALS IF A
SINGLE DOMINANT BAND DEVELOP SIMILAR TO WHAT HAPPENED THIS
PREVIOUS SATURDAY. THE RETURN OF WEST-NORTHWESTERLY FLOW WILL
BRING LOWS DOWN INTO THE UPPER TEENS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
DRYING TREND CAN BE ANTICIPATED INTO THE WEEKEND AS THE UPR FLOW
FLATTENS...ALTHOUGH SUB AVG TEMPS WL CONT UNTIL WARM ADVCTN
INTENSIFIES WITH THE ADVN OF LOW PRES EARLY NXT WEEK. PASSAGE OF
THAT TROF IS GFS AND ECMWF FORECAST TO SPREAD RAIN...OR SNOW OVR
THE UPPER OH VALLEY REGION ON MONDAY AND TUESDAY. CHC POPS WERE
THUS INCLUDED FOR THAT TIME FRAME...BUT RESOLUTION OF PCPN TYPE WL
HAVE TO WAIT UNTIL THE SITUATION FURTHER MATURES.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
DETERIORATION TO GENL IFR WL CONT TDA AS LGT SN...THEN A MIXTURE
OF WINTRY PCPN SPREADS OVR THE REGION WITH LOW PRES EMERGING FM
THE GULF COAST AREA. IFR CONDITIONS WL THEN PREVAIL THROUGH TNGT
WITH COLD ADVCNT CHANGING PCPN TO ALL SNOW.
.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
WDSPRD RSTRNS WL CONT THRU WED NGT AS COLD ADVCTN INTENSIFIES IN
THE WAKE OF EXITING LOW PRES. VFR IS EXPD TO RTN LTR THU WITH BLDG
HIGH PRES AND PERSIST FOR THE RMNDR OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR MDZ001.
OH...WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR OHZ039>041-
048>050-057-058.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR OHZ059-
068-069.
PA...WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR PAZ013>016-
020>022.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ023-
029.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR PAZ031-
073-075.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR PAZ074-076.
WINTER STORM WARNING FROM NOON TODAY TO 4 AM EST THURSDAY FOR
PAZ007>009.
WV...WINTER STORM WARNING UNTIL 1 PM EST WEDNESDAY FOR WVZ001-002.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR WVZ003-
004.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
WEDNESDAY FOR WVZ012-021-022.
WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
625 AM EST TUE NOV 26 2013
.SYNOPSIS...
EAST COAST BOUND LOW PRESSURE WILL SPREAD A WINTRY MIX OF
PRECIPITATION OVER THE REGION TODAY. THAT PRECIPITATION WILL
CHANGE TO ALL SNOW TONIGHT.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
ONLY CHANGES FOR THE NR DAWN UPDATE WERE TWEAKS TO HOURLY TRENDS
OF TEMP...PCPN TYPE...AND NR TERM SNOW AMOUNTS OVR AREAS EAST OF PIT.
PREVIOUS...
A SHORTWAVE MOVING ACROSS OHIO INTO NORTHWESTERN PENNSYLVANIA HAS
ALLOWED FOR A PRECURSOR ROUND OF SNOW IN ADVANCE OF THE MAJOR SYSTEM
ARRIVING THIS MORNING. AN INCH OF SNOW HAS FALLEN AT OUR
OFFICE...AND AREA WEBCAMS SHOW SOME LIGHT ACCUMULATIONS GENERALLY ON
GRASSY SURFACES...ALTHOUGH AREA ROADWAYS STILL APPEAR TO BE MOSTLY
WET. THIS LIGHT SNOW SHOULD CONTINUE THROUGH SUNRISE.
NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS ARE BOTH STARTING THEIR
TREK TO THE EAST...WITH THEIR INTERACTION ABOUT TO AFFECT THE ENTIRE
EAST COAST. SO FAR THE PRECIPITATION SHIELD FROM THE SOUTHERN SYSTEM
IS CONTAINED TO SOUTHERN KENTUCKY AND VIRGINIA...WITH PRECIPITATION
MOVING TO THE NORTHEAST. TRICKIEST PORTION OF THE FORECAST REMAINS
WHAT WILL HAPPEN WITH LOW LEVEL TEMPERATURE PROFILES. ENOUGH WARM
AIR IS EXPECTED TO MOVE IN ALOFT THAT A MIX OF SNOW AND FREEZING
RAIN IS POSSIBLE GENERALLY SOUTH AND EAST OF A LINE FROM ZANESVILLE
TO PITTSBURGH TO DUBOIS DURING THE DAYTIME. IN ADDITION...SURFACE
TEMPERATURES WILL BE CRITICAL...AS PRECIP MAY ACTUALLY FALL AS RAIN
FOR A SEVERAL HOUR PERIOD. LATEST RUNS OF THE RAP STILL SHOW ABOVE
FREEZING TEMPERATURES REACHING ALL THE WAY INTO INDIANA COUNTY NEAR
THE SURFACE. THE RAP CAME IN AS THE WARMEST MODEL FOR SURFACE
TEMPERATURES...BUT IT ALSO USUALLY HANDLES THESE SITUATIONS WELL.
THE HIGHER ELEVATIONS IN THE RIDGES WILL LIKELY HAVE A WINTRY MIX
THROUGH MUCH OF THIS TIME PERIOD WITH AN EXTENDED PERIOD OF FREEZING
RAIN POSSIBLE. NORTH AND WEST OF THE ZZV/PIT/DUJ LINE...SOME SLEET
MAY MIX IN BY THE AFTERNOON...BUT SNOW IS EXPECTED TO BE THE
DOMINANT PRECIPITATION TYPE.
BY EVENING THE TWO SYSTEMS ARE EXPECTED TO BE IN ENOUGH PROXIMITY TO
EACH OTHER TO DEVELOP A COUPLED JET...AND CONSEQUENTLY SHOULD BE THE
TIME PERIOD WHEN THE HIGHEST PRECIPITATION RATES OCCUR. IN THE
RIDGES...FREEZING RAIN WILL CONTINUE THROUGH THE EVENING.
TEMPERATURES WILL LIKELY STILL BE WARM ENOUGH SOUTH AND EAST OF
PITTSBURGH OUTSIDE OF THE HIGHEST ELEVATIONS TO PERSIST WITH RAIN
FOR A FEW HOURS. HOWEVER...WITH ALL SNOW FALLING TO THE WEST OF
PITTSBURGH...SNOW RATES COULD BE QUITE IMPRESSIVE DURING THE EVENING
HOURS FROM ZANESVILLE TO NEW CASTLE AND FRANKLIN. AFTER MIDNIGHT
NEARLY ALL LOCATIONS WILL CHANGEOVER TO SNOW...WITH RATES BEGINNING
TO DIMINISH SLIGHTLY. IF THE WARM LAYER ALOFT PERSISTS...WHICH
LATEST MODELS RUNS HAVE BEEN INDICATING IS POSSIBLE...FREEZING
RAIN MAY HOLD ON FOR A FEW MORE HOURS IN THE RIDGES.
ALTHOUGH ALL LOCATIONS WILL CONTINUE TO RECEIVE SNOW WEDNESDAY
MORNING...THE WIDESPREAD PRECIPITATION SHIELD WILL BE MOVING OFF TO
THE EAST. ALTHOUGH WINDS WILL INITIALLY BE OUT OF THE
NORTH-NORTHWEST...LESS FAVORABLE FOR UPSLOPE/LAKE EFFECT...WINDS
WILL BACK TO THE NORTHWEST BY THE AFTERNOON AND ALLOW THE LAKE
EFFECT MACHINE TO START UP.
ALL IN ALL...ONLY MINOR CHANGES WERE MADE TO THE FORECAST THROUGH
THIS TIME PERIOD. THE AXIS OF HEAVIEST SNOWFALL WAS PUSHED SLIGHTLY
FARTHER TO THE WEST TO ALIGN WITH DEFORMATION ZONE AND THE CHANCES
FOR FREEZING RAIN WERE HELD ONTO LONGER TONIGHT IN THE RIDGES...BUT
OTHERWISE THE INHERITED FORECAST WAS IN GOOD SHAPE. NO CHANGES WERE
NEEDED TO ANY OF THE ADVISORIES OR WARNINGS.
&&
.SHORT TERM /WEDNESDAY NIGHT/...
UPSLOPE AND LAKE EFFECT SNOW WILL CONTINUE WEDNESDAY NIGHT. MODELS
ARE SUGGESTING THAT A DOUBLE LAKE CONNECTION BETWEEN HURON-ERIE IS
POSSIBLE...WHICH COULD RESULT IN SOME LOCALLY HIGHER TOTALS IF A
SINGLE DOMINANT BAND DEVELOP SIMILAR TO WHAT HAPPENED THIS
PREVIOUS SATURDAY. THE RETURN OF WEST-NORTHWESTERLY FLOW WILL
BRING LOWS DOWN INTO THE UPPER TEENS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
DRYING TREND CAN BE ANTICIPATED INTO THE WEEKEND AS THE UPR FLOW
FLATTENS...ALTHOUGH SUB AVG TEMPS WL CONT UNTIL WARM ADVCTN
INTENSIFIES WITH THE ADVN OF LOW PRES EARLY NXT WEEK. PASSAGE OF
THAT TROF IS GFS AND ECMWF FORECAST TO SPREAD RAIN...OR SNOW OVR
THE UPPER OH VALLEY REGION ON MONDAY AND TUESDAY. CHC POPS WERE
THUS INCLUDED FOR THAT TIME FRAME...BUT RESOLUTION OF PCPN TYPE WL
HAVE TO WAIT UNTIL THE SITUATION FURTHER MATURES.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
DETERIORATION TO GENL IFR WL CONT TDA AS LGT SN...THEN A MIXTURE
OF WINTRY PCPN SPREADS OVR THE REGION WITH LOW PRES EMERGING FM
THE GULF COAST AREA. IFR CONDITIONS WL THEN PREVAIL THROUGH TNGT
WITH COLD ADVCNT CHANGING PCPN TO ALL SNOW.
.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
WDSPRD RSTRNS WL CONT THRU WED NGT AS COLD ADVCTN INTENSIFIES IN
THE WAKE OF EXITING LOW PRES. VFR IS EXPD TO RTN LTR THU WITH BLDG
HIGH PRES AND PERSIST FOR THE RMNDR OF THE WEEK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR MDZ001.
OH...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR OHZ039>041-048>050-057-058.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR OHZ059-068-069.
PA...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR PAZ013>016-020>022.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR PAZ023-029.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
WEDNESDAY FOR PAZ031-073-075.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR PAZ074-076.
WINTER STORM WARNING FROM NOON TODAY TO 4 AM EST THURSDAY FOR
PAZ007>009.
WV...WINTER STORM WARNING FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR WVZ001-002.
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 1 PM EST
WEDNESDAY FOR WVZ003-004.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST
WEDNESDAY FOR WVZ012-021-022.
WINTER WEATHER ADVISORY UNTIL 4 AM EST THURSDAY FOR WVZ023-041.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
701 AM EST TUE NOV 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A WELL DEFINED UPSTREAM
MID/UPPER LEVEL LOW/SHORTWAVE TROUGH FROM NW OF LAKE SUPERIOR INTO
NW MN. AT THE SFC...LOW PRES WAS LOCATED NE OF LAKE SUPERIOR(NEAR
WAWA ONTARIO) WITH A COLD FRONT EXTENDING THROUGH WHITEFISH BAY INTO
NW LOWER MI AND A TROUGH STRETCHING TO THE WEST. 700-300 QVECTOR
CONV AHEAD OF THE SHRTWV SUPPORTED SCT -SHSN/FLURRIES FROM NE MN
INTO CNTRL UPPER MI. RADAR ALSO INDICATED AN INCREASE IN LES FROM
FROM NEAR BIG BAY EASTWARD ALIGNED WITH 280-290 LOW LEVEL FLOW.
HOWEVER...WEBCAMS AND SFC OBS OVER WRN UPPER MI DID NOT SHOW A
SIGNFICANT INCREASE IN SNOW INTENSITY OVERNIGHT.
TODAY...EXPECT LES TO INCREASE THIS MORNING OVER THE WEST AS THE MID
LEVEL LOW SLIDES TO THE SOUTHEAST WITH 850/700 MB TEMPS DROPPING TO
-17C/-25C...INCREASING 850-700 MOISTURE AND CLIMBING INVERSION
HEIGHTS. THE HIGHER RES MODELS SUGGEST THAT THE MOST FAVORABLE LOW
LEVEL CONV AND HIGHER LES POTENTIAL IN THE VEERING WIND PATTERN WILL
SET UP BETWEEN TWIN LAKES AND IRONWOOD BEFORE WINDS BEOMCE MORE NNW
LATER IN THE AFTERNOON. HIGHER TERRAIN LOCATIONS SHOULD SEE SNOW
AMOUNTS IN THE 3 TO 6 INCH RANGE WITH SOME LOCALLY HIGHER AMOUNTS
POSSIBLE. OVER THE EAST...THE WNW FLOW SHOULD CONFINE THE STRONGER
LES BANDS TO AREAS NEAR THE LAKE EAST OF MUNISING.
TONIGHT...THERE IS STILL UNCERTAINTY WITH HOW QUICKLY WINDS WILL
VEER OVER THE CNTRL AND EAST WHICH WILL PUSH THE STRONGER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY. MOST OF THE MODELS SUGGEST
THAT THIS WILL OCCUR AT OR LATER THAN 00Z WHEN THE MID LEVEL TROUGH
AXIS MOVES INTO ERN UPPER MI. THE NNW WINDS ARE EXPECTED TO GRADUALLY
VEER TO THE NNE TONIGHT. SO...THE GREATEST SNOWFALL RATES NEAR
MARQUETTE ARE EXPECTED LATE THIS EVENING AND THEN WILL SHIFT INTO THE
HIGHER TERRAIN TO THE WEST AS THE UPSLOPE COMPONENT STRENGTHENS. OVER
THE WEST...THE STRONGEST LOW LEVEL CONV IS EXPECTED INTO
IRONWOOD/WAKEFIELD/BERGLANDWITH SNOWBANDS ORIGINATING NEAR THUNDER
BAY. THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO
6 INCH RANGE.
WITH THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH OF THE
EVENT...SLR VALUES IN THE 20-25/1 RANGE ARE EXPECTED. THERE MAY ALSO
BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE WINDS MAY GUST
TO AROUND 30 MPH. ALTHOUGH THE SNOW MAY SLOW TRAVEL AND MAKE ROADS
HAZARDOUS BUT OVERALL IMPACTS ARE NOT EXPECTED TO BE SEVERE.
SO...GOING LES ADVISORY LEVEL HEADLINES FOR THE NORTHERN CWA IS ON
TRACK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 443 AM EST TUE NOV 26 2013
LK EFFECT COVERAGE AND INTENSITY THROUGH THANKSGIVING IS THE MAIN
FORECAST FOCUS.
IN THE LARGER SCALE TO START WEDNESDAY...SHORTWAVE TROUGH THAT
HELPED TO IGNITE LATEST ROUND OF LAKE EFFECT WILL BE CROSSING LOWER
GREAT LAKES. TROUGH EVENTUALLY MEETS UP WITH PAIR OF SHORTWAVES
PUSHING OUT OF CNTRL AND SOUTHEAST CONUS TO HELP GIN UP STRONG
LOW PRESSURE SYSTEM OVER THE MID ATLANTIC STATES. THAT SYSTEM AND
ITS RAIN/SNOW AND WIND IMPACTS WILL BE PRIME FOCUS FOR THE WEATHER
ACROSS THE CONUS.
BACK ACROSS UPR MICHIGAN...MODERATE LK EFFECT WILL BE ONGOING FOR
NORTH FLOW AREAS. THOUGH THERE IS GRADUAL LOWERING OF INVERSIONS
THROUGH THE DAY ON WEDNESDAY...NORTH WINDS PERSIST IN THE LAKE
CONVECTIVE LAYER AND IT REMAINS PLENTY COLD ENOUGH WITH TEMPS AT
INVERSION TOP OF 5-7KFT STAYING IN THAT IDEAL RANGE OF -15C TO
-20C. BUFKIT COBB OUTPUT SUGGESTS SLR/S AT IWD AND MQT POINTS
NEARING 30:1. CUT THESE SLIGHTLY THOUGH DUE TO SOME FRACTURING OF
SNOWFLAKES WITH WINDS AOA 20 KTS BLO CLOUD BASE. LK EFFECT ADVYS IN
THE SHORT TERM WILL CARRY THROUGH MIDDAY WEDNESDAY IN THE FAR WEST
AND INTO LATE AFTN FOR MARQUETTE COUNTY INTO WESTERN ALGER COUNTY.
EXPECT ADDITIONAL DAYTIME SNOW ACCUMS UP TO 5 INCHES...GREATEST
FOR THE HIGHER TERRAIN OF WESTERN MARQUETTE COUNTY WITH EXPECTED
NNE WINDS BLO 5KFT. AS AFTN WEARS ON...INTENSITY OF SNOW SHOWERS
SHOULD START TO RELAX AS H85-H7 MOISTURE THINS OUT AND LOW-LEVEL
WINDS BECOME MORE ANTICYLONIC...ESPECIALLY FOR FAR WESTERN CWA. AWAY
FM LK EFFECT SHOULD BE GENERALLY CLOUDY DAY AS SOUNDINGS SHOW H85-H8
MOISTURE DUE TO WINDS FLOWING OFF LK SUPERIOR...STAYS TRAPPED
BENEATH LARGER SCALE SUBSIDENCE WHICH IS PRETTY TYPICAL FOR THIS
TIME OF YEAR GIVEN THE LOW SUN ANGLE. TEMPS WILL BE IN THE 20S
ACROSS THE AREA.
WEAKENING LOW-LEVEL FLOW ALLOWS MESOSCALE TO BECOME MAIN DRIVER FOR
CONVERGENCE/LK EFFECT AREAS ON WEDNESDAY NIGHT. LEANED ON THE NAM AS
OUTPUT MADE A LOT OF SENSE WITH EXPECTED SFC PATTERN AND WINDS AT H9
WHICH WILL BE IN THE LAKE CLOUD-BEARING LAYER. AS RETURN FLOW TRIES
TO GET GOING AND ALSO DUE TO LAND BREEZE...MESOLOW PROBABLY FORMS BY
WED EVENING JUST ALONG SHORE FM SAXON HARBOR TO SILVER CITY. AS H9
WINDS BECOME MORE SW...EXPECT SNOW SHOWERS TO LIFT TOWARD KEWEENAW
LATE. MODERATE SNOWS MAY BE ONGOING...BUT IMPACT WOULD BE LIMITED TO
FAR WESTERN SHORE OF KEWEENAW PENINSULA. FARTHER EAST...EXPECT
SIMILAR SETUP IN THE MARQUETTE AREA. WINDS SLOWLY BACKING NRLY IN
THE EVENING LIKELY WILL PUSH SNOW SHOWERS OFF THE HIGHLANDS OF
WESTERN MARQUETTE COUNTY AND TOWARD THE LK SUPERIOR SHORE AND INTO
EASTERN PORTIONS OF MARQUETTE COUNTY. LAND BREEZE MAY ALLOW FOR
DECENT CONVERGENT BAND SOMEWHERE BTWN MARQUETTE/HARVEY AND AU TRAIN.
MINIMAL CHANGE IN H925-H85 TEMPS AND INVERSION HEIGHTS ON WEDNESDAY
NIGHT WOULD ALLOW FOR AT LEAST MODERATE SNOW ACCUMS WITHIN THIS
CONVERGENT AREA. THIS MAY POSE SOME PROBLEM FOR THE ENDING OF THE
HEADLINE ON WEDNESDAY AFTN...BUT WILL LET LATER SHIFTS EXTEND THE
ADVY IF IT IS NEEDED AS DO NOT KNOW EXACTLY WHERE THE HEAVIER SNOW
WOULD END UP. POSSIBLE THAT BAND OF SNOW WILL STILL BE AROUND FOR
DAYBREAK ON THANKSGIVING...BUT THINK THAT THE RETURN FLOW OVER THE
WEST WILL MAKE ITS WAY EAST AND KICK THE MAIN SNOW SHOWERS OUT
ACROSS LK SUPERIOR. SOUNDINGS SHOW INCREASE IN MID-LEVEL MOISTURE
LATE WEDNESDAY NIGHT AS ANOTHER SHORTWAVE DROPS ACROSS UPR LAKES IN
NW FLOW. SMALL POPS AWAY FM LK EFFECT AREAS LATE IN THE WEST TO
ACCOUNT FOR THE SHORTWAVE.
SHORTWAVE CROSSES THE AREA ON THANKSGIVING...MAINLY THROUGH MID AFTN.
ALSO A BIT OF A WEAK SFC TROUGH TOO. SOUNDINGS SHOW DECENT LIFT
OCCURRING FM H9-H7 WHICH IS FIRMLY WHERE THE DGZ RESIDES. EVEN WITH
A BIT OF DRY AIR BLO H85...THINK THE LIFT AND MOISTENING FM ABOVE
WILL BE ENOUGH TO PRODUCE LGT SNOW OVER MUCH OF THE CWA...EXCEPT
MAYBE THE FAR SCNTRL. AMOUNTS WILL BE LESS THAN AN INCH. ONE
EXCEPTION TO THAT COULD BE OVER THE KEWEENAW WHERE ONSHORE
FLOW/CONVERGENCE COULD BOOST SNOW AMOUNTS ALONG TIP OF THE KEWEENAW.
NOT EXPECTING ANY HEADLINE AMOUNTS THOUGH AS WIND FIELDS ARE PRETTY
VARIABLE INDICATING SNOW SHOWERS WILL NOT REMAIN IN ANY ONE LOCATION
VERY LONG. LATEST RUNS SHOW ENOUGH OF SW PUSH IN AFTN TO ADVECT SNOW
SHOWERS OUT OVER NCNTRL LK SUPERIOR. GFS/ECMWF INDICATE LOW PRESSURE
TROUGH THAT IS LEFT BEHIND IN WAKE OF SHORTWAVE SHOULD SINK BACK INTO
AT LEAST NORTHWEST CWA LATER THURSDAY NIGHT. CHANCE POPS FOR SNOW
SHOWERS WERE CARRIED FOR THAT TIME AND INTO FRIDAY AS WELL. EXPECTED
N FLOW IN WAKE OF TROUGH ALSO RESULTED IN LOWER CHANCES LINGERING
INTO NCNTRL CWA. TROUGH AND ANY LINGERING SNOW SHOWERS DISSIPATE BY
FRIDAY EVENING AS PRESSURE GRADIENT REGROUPS AHEAD OF DEVELOPING
TROUGH OVR SCNTRL CANADA.
SHORTWAVE AND SFC TROUGH STAY MAINLY TO THE NORTH OF UPR LAKES FOR
THE UPCOMING WEEKEND. BEST SHOT OF LGT SNOW WILL BE OVR LK SUPERIOR
ON SATURDAY CLOSER TO THE SHORTWAVE/Q-VECTOR CONVERGENCE AND MORE
SATURATED LOW-LEVELS. A LOT OF CLOUD COVER OVER REST OF CWA ALONG
WITH BREEZY SOUTH WIND THAT WILL BRING A RETURN OF SLIGHTLY ABOVE
FREEZING TEMPS OVER MUCH OF CWA. RAN WITH CONSENSUS BEYOND SATURDAY
WITH DIFFERENCES SHOWING UP IN HOW QUICK TO BRING NEXT SHORTWAVE AND
SFC TROUGH/PRECIP INTO UPR LAKES. DOES LOOK LIKE TEMPS WILL STAY
RELATIVELY WARMER /HIGHS IN THE 30S COMPARED TO TEENS OR 20S/ BEFORE
ANOTHER PUSH OF COLDER AIR ARRIVES JUST BEYOND THE SCOPE OF THE LONG
TERM TIME RANGE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 700 AM EST TUE NOV 26 2013
THE PASSAGE OF A LOW PRES TROUGH WILL BRING INCREASING LES INTENSITY
AT IWD/CMX THIS MORNING WITH OCNL IFR CONDITIONS LIKELY. AFTER
ANOTHER LOW PRES TROUGH TRACKS THROUGH THE AREA IN THE EVENING...A
WIND SHIFT TO A MORE N DIRECTION WILL NOT FAVOR CMX...SO MVFR
CONDITIONS ARE EXPECTED THERE. ON THE OTHER HAND...THE WIND SHIFT
WILL FAVOR IWD...SO IFR CONDITIONS SHOULD PREVAIL THERE LATE IN THE
FCST PERIOD. EXPECT VFR WX AT SAW TO PREDOMINATE INTO THIS EVENING WITH
A DOWNSLOPE WIND COMPONENT. BUT CONDITIONS THERE ARE LIKELY TO
DETERIORATE QUICKLY LATE IN THE PERIOD WITH THE WIND SHIFT TO A
FAVORABLE UPSLOPE N DIRECTION FOLLOWING THE LOW PRES TROUGH PASSAGE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EST TUE NOV 26 2013
NW WINDS TO 30 KTS TODAY AS WE ARE IN THE WAKE OF COLD FRONT THAT
MOVED THROUGH MONDAY EVENING. ANOTHER TROUGH DROPS SOUTH ACROSS LK
SUPERIOR LATE TODAY AND THIS EVENING RESULTING IN WINDS SHIFTING TO
NORTH OR NORTHEAST. GALES LOOK LIKELY OVER MAINLY EAST HALF SO GALE
WARNING HAS BEEN POSTED. GALES LINGER INTO WEDNESDAY BEFORE WINDS
QUICKLY DIMINISH TO LESS THAN 20 KTS AS WEAK PRESSURE GRADIENT
DEVELOPS FOR THANKSGIVING. WINDS STAY LIGHT UNTIL SATURDAY WHEN
SOUTH WINDS INCREASE AHEAD OF LOW PRESSURE SYSTEM CROSSING SCNTRL
CANADA. WINDS MAY REACH 30 KTS OVER EASTERN SECTIONS INTO SATURDAY
EVENING. MORE LIGHT WINDS TO END THE WEEKEND AS PRESSURE GRADIENT
RELAXES AGAIN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 3 PM EST
WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL NOON EST /11 AM CST/ WEDNESDAY
FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ004-
084.
LAKE EFFECT SNOW ADVISORY FROM 3 PM THIS AFTERNOON TO 3 PM EST
WEDNESDAY FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 1 PM EST WEDNESDAY FOR LSZ266-267.
GALE WARNING FROM 1 AM TO 10 AM EST WEDNESDAY FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 AM EST TUE NOV 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A WELL DEFINED UPSTREAM
MID/UPPER LEVEL LOW/SHORTWAVE TROUGH FROM NW OF LAKE SUPERIOR INTO
NW MN. AT THE SFC...LOW PRES WAS LOCATED NE OF LAKE SUPERIOR(NEAR
WAWA ONTARIO) WITH A COLD FRONT EXTENDING THROUGH WHITEFISH BAY INTO
NW LOWER MI AND A TROUGH STRETCHING TO THE WEST. 700-300 QVECTOR
CONV AHEAD OF THE SHRTWV SUPPORTED SCT -SHSN/FLURRIES FROM NE MN
INTO CNTRL UPPER MI. RADAR ALSO INDICATED AN INCREASE IN LES FROM
FROM NEAR BIG BAY EASTWARD ALIGNED WITH 280-290 LOW LEVEL FLOW.
HOWEVER...WEBCAMS AND SFC OBS OVER WRN UPPER MI DID NOT SHOW A
SIGNFICANT INCREASE IN SNOW INTENSITY OVERNIGHT.
TODAY...EXPECT LES TO INCREASE THIS MORNING OVER THE WEST AS THE MID
LEVEL LOW SLIDES TO THE SOUTHEAST WITH 850/700 MB TEMPS DROPPING TO
-17C/-25C...INCREASING 850-700 MOISTURE AND CLIMBING INVERSION
HEIGHTS. THE HIGHER RES MODELS SUGGEST THAT THE MOST FAVORABLE LOW
LEVEL CONV AND HIGHER LES POTENTIAL IN THE VEERING WIND PATTERN WILL
SET UP BETWEEN TWIN LAKES AND IRONWOOD BEFORE WINDS BEOMCE MORE NNW
LATER IN THE AFTERNOON. HIGHER TERRAIN LOCATIONS SHOULD SEE SNOW
AMOUNTS IN THE 3 TO 6 INCH RANGE WITH SOME LOCALLY HIGHER AMOUNTS
POSSIBLE. OVER THE EAST...THE WNW FLOW SHOULD CONFINE THE STRONGER
LES BANDS TO AREAS NEAR THE LAKE EAST OF MUNISING.
TONIGHT...THERE IS STILL UNCERTAINTY WITH HOW QUICKLY WINDS WILL
VEER OVER THE CNTRL AND EAST WHICH WILL PUSH THE STRONGER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY. MOST OF THE MODELS SUGGEST
THAT THIS WILL OCCUR AT OR LATER THAN 00Z WHEN THE MID LEVEL TROUGH
AXIS MOVES INTO ERN UPPER MI. THE NNW WINDS ARE EXPECTED TO GRADUALLY
VEER TO THE NNE TONIGHT. SO...THE GREATEST SNOWFALL RATES NEAR
MARQUETTE ARE EXPECTED LATE THIS EVENING AND THEN WILL SHIFT INTO THE
HIGHER TERRAIN TO THE WEST AS THE UPSLOPE COMPONENT STRENGTHENS. OVER
THE WEST...THE STRONGEST LOW LEVEL CONV IS EXPECTED INTO
IRONWOOD/WAKEFIELD/BERGLANDWITH SNOWBANDS ORIGINATING NEAR THUNDER
BAY. THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO
6 INCH RANGE.
WITH THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH OF THE
EVENT...SLR VALUES IN THE 20-25/1 RANGE ARE EXPECTED. THERE MAY ALSO
BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE WINDS MAY GUST
TO AROUND 30 MPH. ALTHOUGH THE SNOW MAY SLOW TRAVEL AND MAKE ROADS
HAZARDOUS BUT OVERALL IMPACTS ARE NOT EXPECTED TO BE SEVERE.
SO...GOING LES ADVISORY LEVEL HEADLINES FOR THE NORTHERN CWA IS ON
TRACK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 443 AM EST TUE NOV 26 2013
LK EFFECT COVERAGE AND INTENSITY THROUGH THANKSGIVING IS THE MAIN
FORECAST FOCUS.
IN THE LARGER SCALE TO START WEDNESDAY...SHORTWAVE TROUGH THAT
HELPED TO IGNITE LATEST ROUND OF LAKE EFFECT WILL BE CROSSING LOWER
GREAT LAKES. TROUGH EVENTUALLY MEETS UP WITH PAIR OF SHORTWAVES
PUSHING OUT OF CNTRL AND SOUTHEAST CONUS TO HELP GIN UP STRONG
LOW PRESSURE SYSTEM OVER THE MID ATLANTIC STATES. THAT SYSTEM AND
ITS RAIN/SNOW AND WIND IMPACTS WILL BE PRIME FOCUS FOR THE WEATHER
ACROSS THE CONUS.
BACK ACROSS UPR MICHIGAN...MODERATE LK EFFECT WILL BE ONGOING FOR
NORTH FLOW AREAS. THOUGH THERE IS GRADUAL LOWERING OF INVERSIONS
THROUGH THE DAY ON WEDNESDAY...NORTH WINDS PERSIST IN THE LAKE
CONVECTIVE LAYER AND IT REMAINS PLENTY COLD ENOUGH WITH TEMPS AT
INVERSION TOP OF 5-7KFT STAYING IN THAT IDEAL RANGE OF -15C TO
-20C. BUFKIT COBB OUTPUT SUGGESTS SLR/S AT IWD AND MQT POINTS
NEARING 30:1. CUT THESE SLIGHTLY THOUGH DUE TO SOME FRACTURING OF
SNOWFLAKES WITH WINDS AOA 20 KTS BLO CLOUD BASE. LK EFFECT ADVYS IN
THE SHORT TERM WILL CARRY THROUGH MIDDAY WEDNESDAY IN THE FAR WEST
AND INTO LATE AFTN FOR MARQUETTE COUNTY INTO WESTERN ALGER COUNTY.
EXPECT ADDITIONAL DAYTIME SNOW ACCUMS UP TO 5 INCHES...GREATEST
FOR THE HIGHER TERRAIN OF WESTERN MARQUETTE COUNTY WITH EXPECTED
NNE WINDS BLO 5KFT. AS AFTN WEARS ON...INTENSITY OF SNOW SHOWERS
SHOULD START TO RELAX AS H85-H7 MOISTURE THINS OUT AND LOW-LEVEL
WINDS BECOME MORE ANTICYLONIC...ESPECIALLY FOR FAR WESTERN CWA. AWAY
FM LK EFFECT SHOULD BE GENERALLY CLOUDY DAY AS SOUNDINGS SHOW H85-H8
MOISTURE DUE TO WINDS FLOWING OFF LK SUPERIOR...STAYS TRAPPED
BENEATH LARGER SCALE SUBSIDENCE WHICH IS PRETTY TYPICAL FOR THIS
TIME OF YEAR GIVEN THE LOW SUN ANGLE. TEMPS WILL BE IN THE 20S
ACROSS THE AREA.
WEAKENING LOW-LEVEL FLOW ALLOWS MESOSCALE TO BECOME MAIN DRIVER FOR
CONVERGENCE/LK EFFECT AREAS ON WEDNESDAY NIGHT. LEANED ON THE NAM AS
OUTPUT MADE A LOT OF SENSE WITH EXPECTED SFC PATTERN AND WINDS AT H9
WHICH WILL BE IN THE LAKE CLOUD-BEARING LAYER. AS RETURN FLOW TRIES
TO GET GOING AND ALSO DUE TO LAND BREEZE...MESOLOW PROBABLY FORMS BY
WED EVENING JUST ALONG SHORE FM SAXON HARBOR TO SILVER CITY. AS H9
WINDS BECOME MORE SW...EXPECT SNOW SHOWERS TO LIFT TOWARD KEWEENAW
LATE. MODERATE SNOWS MAY BE ONGOING...BUT IMPACT WOULD BE LIMITED TO
FAR WESTERN SHORE OF KEWEENAW PENINSULA. FARTHER EAST...EXPECT
SIMILAR SETUP IN THE MARQUETTE AREA. WINDS SLOWLY BACKING NRLY IN
THE EVENING LIKELY WILL PUSH SNOW SHOWERS OFF THE HIGHLANDS OF
WESTERN MARQUETTE COUNTY AND TOWARD THE LK SUPERIOR SHORE AND INTO
EASTERN PORTIONS OF MARQUETTE COUNTY. LAND BREEZE MAY ALLOW FOR
DECENT CONVERGENT BAND SOMEWHERE BTWN MARQUETTE/HARVEY AND AU TRAIN.
MINIMAL CHANGE IN H925-H85 TEMPS AND INVERSION HEIGHTS ON WEDNESDAY
NIGHT WOULD ALLOW FOR AT LEAST MODERATE SNOW ACCUMS WITHIN THIS
CONVERGENT AREA. THIS MAY POSE SOME PROBLEM FOR THE ENDING OF THE
HEADLINE ON WEDNESDAY AFTN...BUT WILL LET LATER SHIFTS EXTEND THE
ADVY IF IT IS NEEDED AS DO NOT KNOW EXACTLY WHERE THE HEAVIER SNOW
WOULD END UP. POSSIBLE THAT BAND OF SNOW WILL STILL BE AROUND FOR
DAYBREAK ON THANKSGIVING...BUT THINK THAT THE RETURN FLOW OVER THE
WEST WILL MAKE ITS WAY EAST AND KICK THE MAIN SNOW SHOWERS OUT
ACROSS LK SUPERIOR. SOUNDINGS SHOW INCREASE IN MID-LEVEL MOISTURE
LATE WEDNESDAY NIGHT AS ANOTHER SHORTWAVE DROPS ACROSS UPR LAKES IN
NW FLOW. SMALL POPS AWAY FM LK EFFECT AREAS LATE IN THE WEST TO
ACCOUNT FOR THE SHORTWAVE.
SHORTWAVE CROSSES THE AREA ON THANKSGIVING...MAINLY THROUGH MID AFTN.
ALSO A BIT OF A WEAK SFC TROUGH TOO. SOUNDINGS SHOW DECENT LIFT
OCCURRING FM H9-H7 WHICH IS FIRMLY WHERE THE DGZ RESIDES. EVEN WITH
A BIT OF DRY AIR BLO H85...THINK THE LIFT AND MOISTENING FM ABOVE
WILL BE ENOUGH TO PRODUCE LGT SNOW OVER MUCH OF THE CWA...EXCEPT
MAYBE THE FAR SCNTRL. AMOUNTS WILL BE LESS THAN AN INCH. ONE
EXCEPTION TO THAT COULD BE OVER THE KEWEENAW WHERE ONSHORE
FLOW/CONVERGENCE COULD BOOST SNOW AMOUNTS ALONG TIP OF THE KEWEENAW.
NOT EXPECTING ANY HEADLINE AMOUNTS THOUGH AS WIND FIELDS ARE PRETTY
VARIABLE INDICATING SNOW SHOWERS WILL NOT REMAIN IN ANY ONE LOCATION
VERY LONG. LATEST RUNS SHOW ENOUGH OF SW PUSH IN AFTN TO ADVECT SNOW
SHOWERS OUT OVER NCNTRL LK SUPERIOR. GFS/ECMWF INDICATE LOW PRESSURE
TROUGH THAT IS LEFT BEHIND IN WAKE OF SHORTWAVE SHOULD SINK BACK INTO
AT LEAST NORTHWEST CWA LATER THURSDAY NIGHT. CHANCE POPS FOR SNOW
SHOWERS WERE CARRIED FOR THAT TIME AND INTO FRIDAY AS WELL. EXPECTED
N FLOW IN WAKE OF TROUGH ALSO RESULTED IN LOWER CHANCES LINGERING
INTO NCNTRL CWA. TROUGH AND ANY LINGERING SNOW SHOWERS DISSIPATE BY
FRIDAY EVENING AS PRESSURE GRADIENT REGROUPS AHEAD OF DEVELOPING
TROUGH OVR SCNTRL CANADA.
SHORTWAVE AND SFC TROUGH STAY MAINLY TO THE NORTH OF UPR LAKES FOR
THE UPCOMING WEEKEND. BEST SHOT OF LGT SNOW WILL BE OVR LK SUPERIOR
ON SATURDAY CLOSER TO THE SHORTWAVE/Q-VECTOR CONVERGENCE AND MORE
SATURATED LOW-LEVELS. A LOT OF CLOUD COVER OVER REST OF CWA ALONG
WITH BREEZY SOUTH WIND THAT WILL BRING A RETURN OF SLIGHTLY ABOVE
FREEZING TEMPS OVER MUCH OF CWA. RAN WITH CONSENSUS BEYOND SATURDAY
WITH DIFFERENCES SHOWING UP IN HOW QUICK TO BRING NEXT SHORTWAVE AND
SFC TROUGH/PRECIP INTO UPR LAKES. DOES LOOK LIKE TEMPS WILL STAY
RELATIVELY WARMER /HIGHS IN THE 30S COMPARED TO TEENS OR 20S/ BEFORE
ANOTHER PUSH OF COLDER AIR ARRIVES JUST BEYOND THE SCOPE OF THE LONG
TERM TIME RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1242 AM EST TUE NOV 26 2013
A WEAK HI PRES RDG/FAIRLY DRY LLVL AIR SHOWN ON THE 00Z INL RAOB WL
BRING A LULL IN THE LES EARLY THIS MRNG...WITH NO WORSE THAN MVFR
CONDITIONS PREDOMINATING EVEN WITH AN UPSLOPE WNW FLOW AT IWD AND
CMX. BUT THE PASSAGE OF A LO PRES TROF ARND SUNRISE WL LIKELY
REINTENSIFY THE SHSN AT THESE LOCATIONS AND CAUSE SOME IFR VSBYS.
ALTHOUGH ANOTHER LO PRES TROF WL TRACK THRU THE AREA IN THE EVNG...
A WSHFT TO A MORE N DIRECTION WL NOT FAVOR CMX...SO FCST MVFR
CONDITIONS HERE. ON THE OTHER HAND...THIS WSHFT WL FAVOR IWD...SO
IFR CONDITIONS SHOULD PREVAIL THERE LATE IN THE FCST PERIOD. EXPECT
VFR WX AT SAW TO PREDOMINATE INTO THIS EVNG WITH A DOWNSLOPE WIND
COMPONENT. BUT CONDITIONS THERE ARE LIKELY TO DETERIORATE QUICKLY
LATE IN THE PERIOD WITH THE WSHFT TO A FVRBL UPSLOPE N DIRECTION
FOLLOWING THE LO PRES TROF PASSAGE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EST TUE NOV 26 2013
NW WINDS TO 30 KTS TODAY AS WE ARE IN THE WAKE OF COLD FRONT THAT
MOVED THROUGH MONDAY EVENING. ANOTHER TROUGH DROPS SOUTH ACROSS LK
SUPERIOR LATE TODAY AND THIS EVENING RESULTING IN WINDS SHIFTING TO
NORTH OR NORTHEAST. GALES LOOK LIKELY OVER MAINLY EAST HALF SO GALE
WARNING HAS BEEN POSTED. GALES LINGER INTO WEDNESDAY BEFORE WINDS
QUICKLY DIMINISH TO LESS THAN 20 KTS AS WEAK PRESSURE GRADIENT
DEVELOPS FOR THANKSGIVING. WINDS STAY LIGHT UNTIL SATURDAY WHEN
SOUTH WINDS INCREASE AHEAD OF LOW PRESSURE SYSTEM CROSSING SCNTRL
CANADA. WINDS MAY REACH 30 KTS OVER EASTERN SECTIONS INTO SATURDAY
EVENING. MORE LIGHT WINDS TO END THE WEEKEND AS PRESSURE GRADIENT
RELAXES AGAIN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 3 PM EST
WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL NOON EST /11 AM CST/ WEDNESDAY
FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ004-
084.
LAKE EFFECT SNOW ADVISORY FROM 3 PM THIS AFTERNOON TO 3 PM EST
WEDNESDAY FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 1 PM EST WEDNESDAY FOR LSZ266-267.
GALE WARNING FROM 1 AM TO 10 AM EST WEDNESDAY FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
648 AM EST TUE NOV 26 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM OVER THE NORTHERN GULF OF MEXICO
WILL RAPIDLY INTENSIFY AS IT LIFTS NORTHEASTWARD THROUGH THE
CAROLINAS AND MIDDLE ATLANTIC STATES TODAY AND TONIGHT. ARCTIC HIGH
PRESSURE WILL BUILD EAST OF THE APPALACHIANS WEDNESDAY AND WEDNESDAY
NIGHT...THEN LINGER THROUGH THE END OF THE WEEK.
&&
UPDATED TO ADD GRANVILLE...VANCE...AND STANLY COUNTIES TO THE
WINTER WEATHER ADVISORY.
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM TUESDAY...
PRECIPITATION HAS BEEN A LITTLE SLOWER THAN EXPECTED TO SPREAD IN TO
CENTRAL NC THIS MORNING...WITH ONLY KINT HAVING REPORTED A LITTLE
MIX OF SLEET AND RAIN THUS FAR. ISENTROPIC UPGLIDE DRIVEN BY A
STRENGTHENING AND EASTWARD-EXPANDING H85 LLJ OF 35-40 KTS WILL
NONETHELESS SUPPORT FURTHER LIFT AND MOISTENING TO ALLOW INCREASING
RADAR RETURNS PER KGSP RADAR TO OVERSPREAD THE NORTHWEST PIEDMONT
BETWEEN 5 AND 8 AM...PER RECENT RUNS OF THE HRRR AND RAP. THE
SPECIAL RELEASE 06Z KGSO RAOB INDICATED THIS MOISTENING PROCESS WAS
WELL UNDERWAY...WITH JUST A COUPLE OF SHALLOW...BUT STOUT DRY LAYERS
AROUND 10 THOUSAND...AND THE LOWEST 3 THOUSAND...FT REMAINING. THE
FORECAST WET BULB FREEZING LINE IS STILL FORECAST TO RETREAT ACROSS
THE PIEDMONT THROUGH 10-11 AM...A LITTLE MORE SLOWLY THAN EARLIER
PROGGED...AND STILL PROBABLY LINGERING OVER FORSYTH AND PERSON
COUNTIES UNTIL AROUND NOON OR SO. IT WILL TAKE SOME TIME FOR THE
PRECIPITATION TO EDGE INTO THE TRIANGLE - BETWEEN 8-11 AM - AND THE
COASTAL PLAIN DURING THE MIDDAY HOURS. THERE WILL CONSEQUENTLY BE
LITTLE OPPORTUNITY FOR ANYTHING BUT A CHILLY RAIN IN THOSE AREAS...
WITH THE EXCEPTION OF THE FAR NORTHERN REACHES OF NORTHERN DURHAM
COUNTY FOR AN HOUR OR TWO. THE PRECIPITATION AMOUNTS DURING THAT
TIME WILL BE SO LIGHT THAT ANY VERY LIGHT FREEZING RAIN WOULD HAVE
LITTLE TO NO IMPACT. THE BETTER CHANCE OF SEEING SEVERAL
HUNDREDTHS...TO AROUND A TENTH OF AN INCH OVER THE FAR NW
PIEDMONT...WILL OCCUR IN THE CURRENT ADVISORY AREA.
THE OTHER NOTABLE TREND IN GUIDANCE HAS BEEN FOR A MORE INLAND TRACK
OF THE SURFACE LOW TAKING SHAPE OVER THE NORTHERN GULF OF MEXICO...
AND ANOTHER PRECEDING LOW FORECAST TO DEVELOP OVER NC AND VA THIS
EVENING...AS THE FORCING FOR ASCENT ATTENDANT THE NORTHERN STREAM
OVERSPREADS THE LOW LEVEL FRONTAL ZONE. WHILE IT IS STILL LIKELY THE
MODELS ARE TOO AGGRESSIVE ERADICATING THE WEDGE AND BARRELING THE
WARM SECTOR ALL THE WAY INTO THE TRIAD THIS EVENING...IT IS HARD
TO IGNORE THIS MORE INLAND TREND EVEN IN THE HI-RES NMM AND ARW
CORES THAT TEND TO BETTER RESOLVE AND RESPECT CAD. EVEN THEY DRIVE
THE FRONTAL ZONE TO NEAR OR JUST EAST OF HWY 1...AND THIS SOLUTION
SEEMS ACCEPTABLE. BIG TEMPERATURE BUSTS REMAIN LIKELY INVOF THE
FRONT...WHICH WILL LIKELY BE CHARACTERIZED BY A 25-30 DEGREE
TEMPERATURE GRADIENT ACROSS SINGLE COUNTIES...WITH 30S IN THE
RESIDUAL IN-SITU WEDGE OVER THE WESTERN PIEDMONT...AND 60S IN THE
WARM SECTOR. TEMPERATURES WILL CHANGE LITTLE OVERNIGHT...WITH SOME
GRADUAL RISES INTO THE 60S IN THE WARM SECTOR THE MOST LIKELY
CHANGE FROM AFTERNOON TEMPS.
THE MORE INLAND WARM SECTOR PENETRATION ALSO RAISES CONCERN FOR
THE POTENTIAL FOR STRONG TO SEVERE CONVECTION...GIVEN THE EXTREME
LOW AND DEEP SHEAR PROFILES ATTENDING THE RAPIDLY DEEPENING LOW
PRESSURE SYSTEM AND INCREASINGLY-PHASED AND NEGATIVELY-TILTED
TROUGH AXES ALOFT. THIS THREAT WOULD BE HIGHEST OVER THE COASTAL
PLAIN AND FAR EASTERN SANDHILLS AND PIEDMONT AS THE NOSE OF THE
LLJ ACCELERATES ACROSS EAST-CENTRAL NC AND SUPPORTS SCATTERED
SURFACE-BASED...OR NEARLY SO...CONVECTION BETWEEN 7 PM AND 2 AM.
FORECAST BUFR SOUNDINGS SUGGEST CONVECTION OF THE ELEVATED
VARIETY COULD OCCUR IN THE CAD REGIME AS WELL...WITH UP TO A FEW
HUNDRED J/KG OF MUCAPE INDICATED ACROSS ALL OF CENTRAL NC FOR
SEVERAL HOURS THIS EVENING-EARLY TONIGHT. A MID LEVEL DRY SLOT MAY
LARGELY END PRECIPITATION FOR A TIME OVERNIGHT...AFTER THE RAIN
BECOMES HEAVY AT TIMES DURING THE AFTERNOON AND EVENING HOURS. THE
BULK OF THE PREVIOUSLY FORECAST ONE TO TWO INCHES OF SOAKING RAIN
(WELL BELOW FLASH FLOOD GUIDANCE)... HIGHEST WEST...WILL HAVE
FALLEN BY THAT TIME. THE LEADING EDGE OF CONCENTRATED DCVA
ATTENDING THE POTENT SOUTHERN STREAM SHORTWAVE TROUGH OVER WEST TX
SHOULD THEN RESULT IN THE REDEVELOPMENT OF RAIN...PERHAPS IN THE
FORM OF A BAND OF SHALLOW ELEVATED CONVECTION...LATE TONIGHT INTO
EARLY WEDNESDAY. AREAS OF FOG... INCLUDING SOME DENSE OVER THE
WESTERN PIEDMONT...WILL ALSO BE PROBABLE ON THE COOL SIDE OF THE
BOUNDARY TONIGHT.
&&
.SHORT TERM /WEDNESDAY/...
AS OF 345 AM TUESDAY...
GUIDANCE REMAINS CONSISTENT THAT THE DEPTH OF THE SATURATED LAYER
WILL STRUGGLE TO REACH THE MINUS 10 LEVEL...AS THE STRONGEST HEIGHT
FALLS/DYNAMICS ALOFT PIVOT NORTHEASTWARD. THE EXCEPTION WILL BE OVER
THE WESTERN AND NORTHERN PIEDMONT...WHERE BRIEF DEEPENING TO NEAR
MINUS 12...IN BAND OF LAST GASP DEFORMATION PRECIPITATION...IS
FORECAST TO OCCUR IN THE SEVERAL HOURS CENTERED AROUND 18Z. A FEW
WET FLAKES MAY CONSEQUENTLY MIX WITH THE RAIN AS THE PRECIPITATION
COMES TO AND END DURING THE AFTERNOON. AREAS OUTSIDE OF THE
DEFORMATION BAND...NAMELY OVER THE COASTAL COLAN AND PERHAPS
SANDHILLS...WILL LIKELY RECEIVE LITTLE TO NO ADDITIONAL RAIN...WITH
JUST A PARTLY CLOUDY SKY IN THE DRY SLOT. ALL AREAS WILL
EXPERIENCE STRONG CAA...HOWEVER...WITH TEMPERATURES TUMBLING INTO
THE 40S... AND 30S OVER THE WESTERN PIEDMONT...DURING THE LATE
MORNING TO EARLY AFTERNOON HOURS. BLUSTERY NW WINDS WILL ALSO GUST
TO BETWEEN 30 AND 35 MPH AS THE FRESH ARCTIC AIR MASS SURGES
ACROSS THE STATE BEHIND THE RAPIDLY DEEPENING LOW BOUND FOR NEW
ENGLAND AND EASTERN CANADA...WHICH WILL YIELD WIND CHILL VALUES
ABOUT 15 DEGREES COOLER THAN THE AFOREMENTIONED AIR TEMPS IN THE
30S-40S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AS OF 250 AM TUESDAY...
WEDNESDAY NIGHT THROUGH SUNDAY: AS THE COLD FRONT MOVES FARTHER OFF
THE CAROLINA COAST AND THE LOW MOVES NE AWAY FROM THE AREA...SKIES
WILL BEGIN TO CLEAR AND LOW TEMPS FOR WEDNESDAY NIGHT WILL DROP INTO
THE LOW 20S NW TO UPPER 20S EAST. WINDS WILL REMAIN BREEZY OVERNIGHT
UNTIL THE PRESSURE GRADIENT RELAXES AND SURFACE HIGH PRESSURE MOVES
OVER THE APPALACHIANS ON THURSDAY. WITH THE COLD HIGH PRESSURE IN
PLACE...EXPECT HIGHS ON THURSDAY IN THE UPPER 30S TO LOW 40 AND
OVERNIGHT LOWS SIMILAR TO THE PREVIOUS NIGHT...LOW TO UPPER 20S. THE
SURFACE HIGH SHOULD MIGRATE OVER THE GREAT LAKES AND INTO THE
NORTHEAST BY FRIDAY WITH THE RIDGE EXTENDING SOUTHWEST INTO CENTRAL
NC WHERE IT WILL REMAIN THROUGH SUNDAY. THE RESULT WILL BE A DRY
FORECAST...MAINLY CLEAR SKIES AND COLD TEMPERATURES...WITH HIGHS
FRIDAY IN THE MID TO UPPER 40S. HIGHS SATURDAY AND SUNDAY WILL BE
DEPENDENT ON THE EASTWARD EXTENT OF THE WEDGE...BUT FOR NOW EXPECT
GRADUALLY INCREASING HIGHS IN THE EAST INTO THE MID 50S BY SUNDAY...
AND A SLOWER INCREASE IN THE NW...UPPER 40S SUNDAY. EXPECT A SIMILAR
TREND IN OVERNIGHT LOWS...MID 20S TO NEAR 30 DEGREES FRIDAY NIGHT
INCREASING SLIGHTLY INTO THE MID 20S TO LOW 30S FOR SATURDAY NIGHT.
SUNDAY NIGHT THROUGH MONDAY NIGHT: THERE ARE DIFFERENCES BETWEEN THE
MODELS WITH RESPECT TO UPPER LEVEL TROUGH AND PRECIP DEVELOPMENT FOR
THIS PART OF THE FORECAST...BUT THEY INDICATE THE RIDGE WEAKENING
AND CLOUD COVER INCREASING SUNDAY NIGHT AND MONDAY. EXPECT THE
COLUMN TO MOISTEN AND CHANCES FOR PRECIP TO INCREASE...HOWEVER
NAILING DOWN ANY TIMING IS DIFFICULT AT THIS TIME. FOR NOW WILL
GRADUALLY INCREASE PRECIP CHANCES SUNDAY NIGHT THROUGH MONDAY NIGHT.
SHOULD SEE HIGH TEMPS MODERATE A BIT...MID 50S TO LOW 60S FOR
MONDAY. OVERNIGHT LOWS GENERALLY IN THE MID 30S TO LOW 40S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 645 AM TUESDAY...
24 HOUR TAF PERIOD: FREEZING RAIN HAS BEEN REPORTED THIS HOUR AT
KGSO WITH UNKNOWN PRECIPITATION OCCURRING AT KINT. TEMPERATURES IN
BOTH LOCATIONS ARE AT 32 DEGREES AND EXPECTED TO REMAIN THERE FOR
THE NEXT COUPLE OF HOURS. RADAR SHOWS STEADY LIGHT RAIN OVER THE
TRIAD BUT PERHAPS A BREAK IN THE RAIN COMING UP IN THE NEXT HOUR.
AFTER 14Z EXPECT TEMPERATURES TO RISE BACK ABOVE FREEZING AND
MODERATE RAIN WILL BE THE MAIN FORM OF PRECIPITATION FOR THE REST OF
THE DAY. TO THE EAST NO THREAT OF FREEZING RAIN BUT MODERATE RAIN
EXPECTED LATER TODAY.
A GRAB BAG OF AVIATION CONDITIONS OUT THERE THIS MORNING WITH SOME
IFR CEILINGS IN THE SOUTH...MAINLY MVFR IN THE NORTHWEST AND VFR
HANGING ON IN THE EAST BUT NOT FOR LONG AS THEY WILL DIP TO MVFR
AFTER THE ONSET OF PRECIPITATION LATER THIS MORNING.
WINDS TO DAY WILL BE MAINLY NORTHEASTERLY NEAR 10 KNOTS WITH FASTER
WIND SPEEDS IN THE SOUTHEAST. LATER TODAY AS THE LOW APPROACHES
WINDS IN THE NORTHWEST WILL BE NORTHWESTERLY AND WINDS IN THE EAST
WILL BE MORE SOUTHEASTERLY. OFF THE DECK...LOW LEVEL WIND SHEAR WILL
BE A CONCERN NEAR THE 2000 FT LEVEL WITH 35-40 KNOT SOUTHEASTERLY
SHEAR. THE GREATEST CONCERN FOR LLWS WILL BE IN THE TRIAD CONTINUING
THROUGH TODAY TO THE EARLY MORNING HOURS WEDNESDAY. LIKELIHOOD OF
LLWS DECREASES FOR EASTERN TERMINAL BUT WILL STILL BE PRESENT AT
LEAST THROUGH TUESDAY AFTERNOON/EARLY EVENING.
LONG TERM: RAIN WITH THIS SYSTEM WILL CONTINUE INTO WEDNESDAY AND
WIND SPEEDS ARE EXPECTED TO INCREASE WEDNESDAY AFTERNOON WITH GUSTS
UP TO 30 MPH POSSIBLE. THURSDAY THROUGH THE END OF THE WEEK SHOULD
SEE A RETURN TO VFR CONDITIONS UNTIL THE NEXT STORM SYSTEM
APPROACHES EARLY NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NCZ007-
021>024-038-039.
WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR
NCZ008-009-073.
&&
$$
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...MWS
LONG TERM...KC
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
454 PM EST TUE NOV 26 2013
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHEAST STATES LATE THIS AFTERNOON WILL
INTENSIFY AND MOVE UP THE COAST TONIGHT...PASSING OVER THE AREA ON
WEDNESDAY AND THEN HEADING INTO EASTERN CANADA WEDNESDAY NIGHT.
HIGH PRESSURE WILL THEN BUILDS IN FROM THURSDAY THROUGH
SATURDAY...AND MOVE OFF THE NEW ENGLAND COAST ON SUNDAY. A COASTAL
FRONT WILL DEVELOP ON SUNDAY AND REMAIN INTO MONDAY. LOW PRESSURE
WILL DEVELOP ON THE FRONT AND MOVE ALONG THE COAST ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
IMPENDING STORM WILL BRING A VARIETY OF WEATHER HAZARDS BEGINNING
TONIGHT. FIRST...SFC TEMPS HAVE BARELY BUDGED THIS AFTERNOON IN
MOST OF ORANGE COUNTY WHILE TEMPS CONTINUE TO WARM ALOFT...WITH
PRECIP CHANGING TO LIGHT FREEZING RAIN. HAVE THEREFORE CONTINUED
THE WINTER WX ADVISORY THERE INTO THIS EVENING. TEMPS SHOULD
EVENTUALLY RISE LATER THIS EVENING AS LOW LEVEL WARM ADVECTION
CONTINUES...CHANGING PRECIP THERE TO ALL RAIN BY LATE EVENING.
ELSEWHERE...RAIN WILL CONTINUE TONIGHT AND PICK UP IN INTENSITY
FROM LATE EVENING ON AS PRIMARY LOW PRESSURE WEAKENS ALONG A LOW
LEVEL BAROCLINIC ZONE ALONG THE COASTAL PLAIN...AND GIVES WAY TO A
SECONDARY LOW OVER THE MID ATLANTIC FORMING UNDER THE STRENGTHENING
RIGHT ENTRANCE REGION OF A DIFLUENT UPPER JET STREAK APPROACHING
FROM THE WEST AS A NORTHERN/SOUTHERN STREAMS PHASE ALOFT. A S-SE
LOW LEVEL JET WILL INTENSIFY EAST OF THE LOW OVERNIGHT...
TRANSPORTING ATLANTIC/GULF MOISTURE INTO THE REGION AND PROVIDING
AMPLE LOW LEVEL CONVERGENCE/LIFT FOR HEAVY RAIN. OROGRAPHIC LIFT
WILL ALSO COME INTO PLAY NORTH/WEST OF NYC GIVEN THE LOW LEVEL
SE FLOW TO START. GIVEN THESE FACTORS THE POTENTIAL FOR
AREAL/URBAN FLOODING AND FLOODING OF SMALL STREAMS NOW LOOKS
GREAT ENOUGH TO WARRANT A FLOOD WATCH.
THE LLJ ALSO LOOKS STRONG ENOUGH TO SUPPORT STRONG SE-S WINDS
ALONG THE COAST...SO THE WIND ADVY CONTINUES. VERY STRONG NAM LLJ
WITH 85-95 KT AT H8 MAY LOOK LIKE AN OUTLIER COMPARED TO
WEAKER/FARTHER EAST GFS/ECMWF...BUT LATEST RUNS OF THE RAP DO LEND
IT SUPPORT SO AM NOT WILLING TO DISCOUNT IT. SFC-H8 INVERSION
SHOULD PREVENT THE STRONGEST OF THESE WINDS FROM MIXING DOWN.
HOWEVER HAVE A NAGGING CONCERN THAT DUCTED GRAVITY WAVES COULD
AID IN DOWNWARD MOMENTUM TRANSPORT TOWARD MORNING PER AKQ
RESEARCH...AS WEAK INSTABILITY MOVES IN ALOFT JUST NORTH OF AN
APPROACHING WARM FRONT...AND AS THE UPPER JET STREAK APPROACHES
THE DOWNSTREAM INFLECTION POINT BETWEEN THE UPPER TROUGH TO THE
WEST AND OFFSHORE RIDGING...SO POTENTIAL FOR 60+ MPH WIND GUSTS
ACROSS LONG ISLAND AND COASTAL SE CT WILL HAVE TO BE WATCHED. MOST
LIKELY SCENARIO WILL BE FOR SUSTAINED WINDS 25-35 MPH WITH GUSTS
45-50 MPH...MAINLY IN/NEAR NYC AND ALONG THE COAST BEGINNING LATE
TONIGHT.
THERE COULD BE A FEW RUMBLES OF THUNDER LATE AS ELEVATED
INSTABILITY MOVES OVER THE AREA.
TEMPS WILL BE ON THE RISE TONIGHT...REACHING THE MID AND UPPER 50S
BY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE LOW WILL BE MOVING ACROSS THE REGION WED MORNING INTO EARLY
AFTERNOON...THEN RE-CONSOLIDATING TO THE NORTH IN THE AFTERNOON.
HEAVY RAIN...STRONG SOUTHERLY WINDS AND ISOLD RUMBLES OF THUNDER
WILL STILL BE ONGOING INITIALLY...THEN SHOULD SHIFT TO THE EAST
ACROSS ERN LONG ISLAND/CT DURING LATE MORNING AND LIFT UP INTO NEW
ENGLAND BY AFTERNOON AS THIS TAKES PLACE. ENDED WIND ADVY EARLIER
THAN ORIGINALLY FCST SINCE THE LOW TRACK SHOULD BE SLIGHTLY
FARTHER EAST...WITH THE LLJ ALSO PASSING TO THE EAST SOONER.
RAIN SHOULD LESSEN IN INTENSITY AS WELL AS AS THE LLJ PASSES TO
THE EAST.
AS THE LOW MOVES OVER THE AREA...THERE SHOULD BE A RELATIVE LULL
IN WINDS FROM LATE MORNING INTO EARLY AFTERNOON...THEN STRONG NW
WINDS WILL REDEVELOP BY EVENING AS THE LOW CONTINUES TO INTENSIFY
AND SHOULD CONTINUE INTO THE NIGHT...SUSTAINED AT 20-30 MPH WITH
GUSTS UP TO 40 MPH...POSSIBLY STRONGER IN NYC METRO AND LONG
ISLAND WHERE ANOTHER WIND ADVY MAY BE NEEDED. STILL EXPECT SCT
SHOWERS IN THE EVENING AS THE UPPER TROUGH MOVES ACROSS...AND LOW
LEVEL CAA SHOULD CHANGE ANY PRECIP OVER TO SNOW FROM NYC
NORTH/WEST. SOME INTERIOR AREAS COULD SEE A LIGHT COATING OF
ACCUMULATION OF SNOW BEFORE ALL PRECIP ENDS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
VIGOROUS SHORTWAVE IS ROTATING EAST OF THE REGION EARLY THURSDAY
MORNING AS BROAD UPPER TROUGH REMAINS ACROSS THE NORTHEAST. ANOTHER
SHORTWAVE ROTATES THROUGH THE TROUGH LATE THURSDAY INTO THURSDAY
NIGHT. MEANWHILE AT THE SURFACE LOW PRESSURE WILL BE NORTH AND EAST
OF THE AREA AND CONTINUING TO MOVE NORTH DURING THE DAY INTO
THURSDAY NIGHT AS HIGH PRESSURE BUILDS TO THE WEST. INCREASING
SUBSIDENCE BEHIND THE LOW WILL KEEP AREA PRECIPITATION FREE
THURSDAY...ALTHOUGH CLOUDS WILL LINGER EARLY IN THE DAY. UPPER FLOW
BECOMES MORE ZONAL FRIDAY AND INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS OVER THE REGION. WARM ADVECTION SETS UP LATE
SATURDAY NIGHT AND INTO SUNDAY AS HIGH PRESSURE MOVES EAST AND NEXT
SHORTWAVE APPROACHES FROM THE GREAT LAKES. LIFT IS RATHER WEAK AT
THIS TIME AND MOISTURE LIMITED HOWEVER...THERE IS A VERY LOW
PROBABILITY OF LIGHT PRECIPITATION LATE SATURDAY NIGHT. SUNDAY WILL
BE A BETTER CHANCE AS ADVECTION CONTINUES AND GULF MOISTURE MOVES
INTO THE AREA. AS THE HIGH RETREATS TO THE NORTHEAST SATURDAY NIGHT
INTO SUNDAY...COLD AIR DAMNING IS POSSIBLE AND MIXED PRECIPITATION
WILL BE POSSIBLE INLAND AS COASTAL AREAS WARM IN THE SOUTHERLY FLOW.
A COASTAL FRONT DEVELOPS SUNDAY INTO MONDAY AS A WEAK SOUTHERN
STREAM SHORTWAVE MOVES OUT OF THE SOUTHWEST AND INTO THE GULF COAST
REGION. THIS WAVE WILL DEVELOP A LOW ALONG THE COASTAL FRONT MONDAY
INTO TUESDAY. STILL SOME UNCERTAINTY WITH THE TRACK OF LOW WITH THE
ECMWF CLOSER TO THE COAST AND THE GFS MOVING THE LOW FARTHER OFF THE
SOUTHEASTERN COAST AND KEEPING THE REGION ON THE NORTHWESTERN EDGE
OF THE PRECIPITATION TUESDAY.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
HIGH IMPACT AVIATION WEATHER EVENT FOR TONIGHT AND WEDNESDAY.
CONDITIONS DIMINISHING QUICKLY THIS EVENING.
THIS EVENING...WINDS LIGHT SE 5-12 KT WITH LOWERING CEILINGS AND
LIGHT RAIN MOVING ACROSS ENTIRE TERMINAL AREA.
AFTER 00Z...CIGS AND VSBYS LOWER TO IFR OR LESS AND RAIN WILL
BECOME MODERATE TO HEAVY AT TIMES. WINDS AND GUSTS INCREASE AFTER
05Z ESPECIALLY ACROSS THE NYC TERMINALS AND POINTS EAST. BY
08-09Z...GUSTS WILL REACH 35-40 KT. CAN NOT RULE OUT SOME ISOLATED
GUSTS TO 45 KT IN CONVECTIVE ELEMENTS. IN ADDITION...A STRONG LOW LEVEL
JET WILL RESULT IN WIND SHEAR SO HAVE INCLUDED IN THE
TAFS AFTER 08Z. SPEEDS AT 2000 FT COULD APPROACH 70 KT...MAINLY
EASTERN TERMINALS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
KLGA FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
KEWR FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
KTEB FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
KHPN FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
KISP FCSTER COMMENTS: MODERATE TO HIGH CONFIDENCE FORECAST. AMENDMENTS
MAY BE NEEDED TO FINE TUNE ANY WIND SHIFTS AND TIMING OF LOWER
CIGS AND PRECIPITATION THIS EVENING.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH MONDAY...
.WED...LIFR...IMPROVING WEST TO EAST DURING THE AFTERNOON. +RA
THROUGH MID MORNING. STRONG S/SE SURFACE WIND...HIGHEST NY METRO
AND EAST...25-35G40-45KT EARLY AM. WIND LIGHTENS MIDDAY AS LOW
PASSES JUST WEST OF NY METRO. WIND VEERS SW/W LATE AND INCREASES
AGAIN. LLWS AND COMPRESSION LIKELY WITH 70+ KT AT FL020 IN THE
EARLY AM.
.WED NGT. MVFR...BECOMING VFR. CHC -SHSNRA. W/NW WINDS 20-25G35KT.
.THU...VFR. NW WINDS 20-25G30-35KT EARLY SLOWLY DIMINISHING TO G20KT
BY EVENING.
.THU NGT-SAT...VFR.
.SUN AND MON...MVFR CIG. -DZ / -RA. SE SFC FLOW 10-15 KT.
&&
.MARINE...
THE PRESSURE GRADIENT WILL QUICKLY TIGHTEN TONIGHT AHEAD OF AN
ADVANCING STORM SYSTEM TRACKING FROM THE SOUTHEASTERN TO COASTAL
MID ATLANTIC STATES TONIGHT...WITH WIND GUSTS TO GALE LEVELS
DEVELOPING AFTER MIDNIGHT. A FEW GUSTS TO STORM FORCE MAY BE
POSSIBLE TOWARD MORNING...MAINLY ON THE ERN OCEAN WATERS...BUT
THESE SHOULD BE BRIEF AT BEST AND SO DID NOT UPGRADE ANY AREAS TO
A STORM WARNING. WILL USE SPECIAL MARINE WARNINGS TO ADDRESS ANY
WIND GUSTS OF 48 KT OR HIGHER IN ISOLATED STRONGER CONVECTION.
SEAS COULD BUILD AS HIGH AS 16 FT ON THE ERN OCEAN WATERS WITH THE
STRONGEST SOUTHERLY WINDS.
THERE COULD BE A LULL IN WINDS FROM LATE WED MORNING INTO THE
AFTERNOON...BUT THEN NW GALES ARE EXPECTED WED NIGHT INTO
THU MORNING...WITH SEAS UP TO 15 FT EXPECTED WED NIGHT ON THE
OCEAN AND AS HIGH AS 7 FT ON LONG ISLAND SOUND AS THE SURFACE LOW
CONTINUES TO TRACK TO THE NORTH THROUGH CANADA AND HIGH PRESSURE
BUILDS TO THE WEST. THE WIND WILL BE DIMINISHING THROUGH THE DAY
THURSDAY...SUBSIDING BELOW GALE FORCE DURING THE AFTERNOON...AND
THEN QUICKLY FALLING BELOW 25 KT DURING THURSDAY EVENING.
VERY ROUGH SEAS ON THE OCEAN WATERS SUBSIDE DURING THURSDAY IN THE
WEST TO NORTHWEST FLOW. BY LATE THURSDAY NIGHT SEAS ARE EXPECTED TO
FALL BELOW 5 FT AS THE WESTERLY FLOW DIMINISHES.
WIND AND SEAS REMAIN BELOW ADVISORY LEVELS FRIDAY INTO SUNDAY.
DEPENDING ON THE STRENGTH OF THE WIND AROUND A DEPARTING HIGH AND A
DEVELOPING TROUGH ALONG THE COAST...SEAS ON THE OCEAN WATERS MAY
BUILD BACK UP TO SMALL CRAFT LEVELS LATE SUNDAY INTO SUNDAY
NIGHT.
&&
.HYDROLOGY...
WIDESPREAD RAINFALL TOTALS FORECAST RANGE BETWEEN 2 AND 3 INCHES
WITH LOCAL AMOUNTS UP TO 4 INCHES. DUE RECENT PROLONGED DRY
CONDITIONS...MAIN STEM RIVER FLOODING IS NOT EXPECTED.
HOWEVER...THERE IS ENOUGH CHANCE OF URBAN/AREAL/SMALL STREAM
FLOODING...ESPECIALLY WHERE STORM DRAINS ARE CLOGGED BY LEAVES
AND ESSENTIALLY WHERE THERE IS MORE RUNOFF....TO WARRANT A FLOOD
WATCH FROM LATE TONIGHT INTO WED AFTERNOON.
LIGHT PRECIPITATION IS POSSIBLE SUNDAY INTO TUESDAY...WITH A TOTAL
OF UP TO A HALF INCH EXPECTED AT THIS TIME.
&&
.TIDES/COASTAL FLOODING...
A GALE FORCE SE FLOW WILL RAPIDLY DEVELOP AHEAD OF DEEPENING LOW
PRESSURE LATE TONIGHT...BEFORE VEERING TO THE S WEDNESDAY MORNING. A
STORM SURGE OF 2 TO 2 1/2 FT...LOCALLY 3 FT IS EXPECTED. THE PEAK
SURGE COINCIDES BEST WITH THE TIMING OF THE MORNING HIGH TIDE CYCLE
IN WESTERN LONG ISLAND SOUND AND PECONIC BAY. AN ADVISORY HAS BEEN
ISSUED IN THESE LOCATIONS WITH COMBINED THREAT OF STORM TIDE...WAVE
SPLASH-OVER...AND HEAVY RAIN CAUSING WIDESPREAD MINOR IMPACTS.
ELSEWHERE...TIMING OF PEAK SURGE AND HIGH TIDE APPEARS TO BE
OFFSET...WITH ONLY LOCALIZED ISSUES EXPECTED WITH WEDNESDAY MORNING
HIGH TIDE DUE TO STORM TIDE AND HEAVY RAIN. A COASTAL FLOOD
STATEMENT HAS BEEN ISSUED TO ADDRESS THIS THREAT.
FOR THE LATE AFTERNOON/EVENING HIGH TIDE CYCLE...WITH FLOW
EXPECTED TO BEGIN TURN OFFSHORE WOULD EXPECT SURGE VALUES TO BEGIN
TO FALL RAPIDLY FROM AFTERNOON ON. THE ONLY AREA TO MONITOR WOULD BE
THE SOUTH SHORE BACK BAYS WITH HIGH SURF LIMITING TIDAL DRAINAGE.
HIGH SURF AND MINOR EROSION ISSUES ARE EXPECTED LATE TONIGHT THROUGH
LATE WEDNESDAY NIGHT FROM BATTERING SURF OF 7-11 FT. MAIN CONCERN
WILL BE THE VULNERABLE DUNES AND BREACH LOCATIONS POST SANDY. A HIGH
SURF ADVISORY HAS BEEN ISSUED TO ADDRESS THIS THREAT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR CTZ005>012.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EST WEDNESDAY FOR
CTZ008-011-012.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
CTZ007-009-010.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
CTZ009-010.
NY...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR NYZ067>075-078>081-176>179.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EST WEDNESDAY FOR
NYZ078>081-177-179.
COASTAL FLOOD ADVISORY FROM 6 AM TO 9 AM EST WEDNESDAY FOR
NYZ079-081.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
NYZ071>075-176-178.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
NYZ071-073.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ067.
HIGH SURF ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EST
WEDNESDAY NIGHT FOR NYZ080-081-178-179.
NJ...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR NJZ002-004-006-103>108.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
NJZ006.
MARINE...GALE WARNING FROM MIDNIGHT TONIGHT TO 6 AM EST THURSDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/MET
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...MET
AVIATION...IRD
MARINE...GOODMAN/MET
HYDROLOGY...GOODMAN/MET
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
415 PM EST TUE NOV 26 2013
.DISCUSSION...
...STRONG THUNDERSTORMS POSSIBLE AFTER SUNSET TONIGHT...
...TURNING MUCH COLDER WEDNESDAY NIGHT INTO THANKSGIVING MORNING...
CURRENTLY/TONIGHT...
CENTRAL FL REMAINS WELL INSIDE THE WARM SECTOR OF THE DVLPG GOMEX
SYSTEM AS AFTN SFC DEWPOINTS REMAIN IN THE U60S/L70S...SFC TEMPS IN
THE U70S/L80S. PREFRONTAL SQUALL LINE HAS DVLPD OVER THE ERN GOMEX
PER LATEST SAT PICS/KTBW RADAR IMAGERY. RUC ANALYSIS SHOWS A POCKET
OF ENHANCED H85-H50 VORTICITY DUE W OF TAMPA CONCURRENT WITH THE
SQUALL LINE...AS WELL AS MODERATE TO STRONG UPR LVL DIVERGENCE
AREAWIDE. H85-H50 STEERING FLOW INDICATES THE CORE ENERGY WILL TRACK
N OF THE I-4 CORRIDOR LATER THIS EVENING...THOUGH LATEST KTBW
TRAJECTORY SHOWS THE BULK OF THE RAINFALL WITH THE CONVECTIVE LINE
LIFTING MORE TOWARD THE BIG BEND.
OUTSIDE OF THE VORT MAX...MID LVL DYNAMIC SUPPORT IS QUITE WEAK WITH
LITTLE IN THE WAY OF DEEP MID LYR VORTICITY OR OMEGA LIFT. MID LVL
LAPSE RATES UNIMPRESSIVE AS WELL...LARGELY BTWN 5.5-6.0C/KM OVER THE
SRN CWA...BLO 5.5C/KM NRN CWA. DESPITE SOME THINNING OF THE MID/UPR
LVL CLOUD DECKS...KMLB/TMCO/KPBI RADARS INDICATE CONVECTION HAS
STRUGGLED TO DVLP WITHIN THIS LCL ENERGY MINIMUM.
DEEP MOISTURE REMAINS IN THE VCNTY OF THE SQUALL LINE WITH H100-H85
AND H85-H50 MEAN RH VALUES AOA 90PCT. MID LVL MOISTURE DIMINISHES A
BIT OVER S FL THOUGH H85-H50 RH STILL BTWN 60-70PCT. MAX 0-3KM
HELICITY VALUES BTWN 300-350 FROM OSCEOLA/BREVARD CO NWD...BUT
EMBEDDED WITHIN A 30-40KT H85-H70 S/SW FLOW THAT WILL CARRY THE BULK
OF IT OUT OF THE CWA BEFORE ANY SIG DESTABILIZATION CAN OCCUR.
ON THE SYNOPTIC SCALE...THE NRN AND SRN STREAM SHORT WAVE TROFS HAVE
MERGED...FORMING A FULL LATITUDE H85-H50 TROF EXTENDING FROM HUDSON
BAY TO THE BAY OF CAMPECHE. THIS TROF WILL DIG STEADILY EWD
OVERNIGHT...PULLING BOTH A STRONG COLD FRONT INTO THE FL PENINSULA.
THE PREFRONTAL CONVECTIVE LINE WILL PUSH INTO CENTRAL FL THRU MID
EVNG WITH AN INITIAL ROUND OF CONVECTION EXPECTED N OF SEBASTIAN
INLET/LAKE KISSIMMEE THRU MIDNIGHT...THEN A SECOND ROUND TO THE S
AFT 3AM. WHILE SVR WX THREAT HAS DIMINISHED...CANNOT RULE OUT HEAVY
RAIN AND LCL STRONG WIND GUSTS AS TSRAS BLOW THROUGH.
BULK OF THE COLD AIR ADVECTION WILL NOT OCCUR UNTIL AFT SUNRISE.
DENSE CLOUD COVER AND STEADY S/SWRLY WINDS OVERNIGHT WILL KEEP MIN
TEMPS 10-15F ABV CLIMO AVG...THE L/M60S N OF I-4...U60S/L70S TO THE
SOUTH.
WED-WED NIGHT...(MODIFIED PREV DISC)
TIMING OF THE SYSTEM SHOULD CARRY THE BULK OF ITS CONVECTION CLEAR
THE CWA BY DAYBREAK AS THE DEEPENING PARENT LOW RACES UP THE ERN
SEABOARD. THE 500MB TROUGH WILL SWING THROUGH BY LATE MORNING...
EFFECTIVELY ENDING ANY PRECIP FOR THE REGION BY MIDDAY. STRONG COLD
AIR ADVECTION WILL COMMENCE QUICKLY BEHIND THE FRONT...BRINGING AN
ARCTIC AIRMASS INTO CENTRAL FL. ITS LIKELY THAT A LAKE WIND ADVISORY
WILL BE NEEDED FOR AT LEAST PART OF THE REGION...MAKING IT THE
FOURTH DAY IN A ROW FOR SOME PLACES.
THE COLD AIR ADVECTION AND LINGERING CLOUD COVER THROUGH LATE
MORNING WILL PREVENT MAX TEMPS FROM RISING MUCH MORE THAN 5F ABOVE
THE MORNING MINS. HIGH IN THE M/U60S ALONG AND N OF I-4...U60S/L70S
TO THE S. MUCH OF THE AREA WILL REACH MAX TEMPS BEFORE NOON THEN
HOLD STEADY OR DROP THRU THE AFTN.
CLEARING SKIES AND STRONG COLD/DRY AIR ADVECTION WILL DROP OVERNIGHT
MINS INTO THE U30S/L40S MOST OF THE CWA W OF I-95. OCEAN INFLUENCE
SHOULD KEEP AREAS E OF I-95 IN THE M/U40S THRU DAYBREAK THU...STILL
A SOLID 20-25F DEG COLDER THAN WED MORNING MINS.
THANKSGIVING DAY-SUNDAY...(PREV DISC)
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT...QUICKLY SPREADING OUT
ACROSS THE DEEP SOUTH AND MID-ATLANTIC BY FRIDAY...BEFORE BEING
REINFORCED BY A SECONDARY HIGH ACROSS NEW ENGLAND INTO THE WEEKEND.
BREEZY NORTH TO NORTH-NORTHEAST FLOW WILL START OFF THE THANKSGIVING
HOLIDAY BEFORE RETURNING TO WHAT HAS BECOME THE DEFAULT PATTERN OF
LATE...BREEZY EAST-NORTHEAST FLOW INTO THE WEEKEND. THE NORTHEAST
WIND SURGE AS THE HIGH BEGINS TO BUILD INTO THE ATLANTIC LATE ON
THURSDAY WILL REINTRODUCE ISOLATED LOW TOPPED ATLANTIC SHOWERS INTO
THE FORECAST THURSDAY NIGHT...AFFECTING COASTAL AREAS FROM FRIDAY
ONWARDS
THANKSGIVING DAY WILL BE COOL AND BLUSTERY WITH HIGHS IN THE MID 60S
IN MOST LOCATIONS. AS THE FLOW REGAINS ITS ONSHORE
COMPONENT...TEMPERATURES WILL MODERATE INTO THE WEEKEND WITH HIGHS
IN THE MID-UPPER 70S AND LOWS IN THE LOW-MID 50S INLAND/MID-UPPER
60S BREVARD/TREASURE COAST BY SATURDAY AND SUNDAY.
&&
.AVIATION...
THRU 27/00Z...S/SE SFC WIND ARND 15KTS WITH G20-25KTS...PREVAILING
VFR VSBYS WITH BRIEF PDS BTWN 3-5SM IN ISOLD SHRAS...VRBL CIGS ALL
SITES PREVAILING BTWN FL080-100 WITH OCNL PDS BTWN FL020-030 IN -RA.
BTWN 27/00Z-27/04Z...WINDS S/SW 10-15KTS WITH 30-35KT SW LLWS PSBL
ALL SITES...SCT NMRS MVFR SHRAS/SCT IFR TSRAS W OF KMLB-KOBE....SCT
MVFR SHRAS/ISOLD IFR TSRAS E OF KMLB-KOBE.
BTWN 27/04Z-27/12Z...SQLN WILL PUSH THRU E CENT FL WITH 35-40KT W/SW
LLWS PSBL ALL SITES. STRONG WIND GUSTS ABOVE 35 KNOTS AND +RA
REDUCING VSBYS/CIGS TO IFR/LIFR CONDS WITH THE PASSAGE OF THE LINE.
&&
.MARINE...
TONIGHT...SCA CONDITIONS TO CONTINUE. LCL DATA BUOY/C-MAN STATIONS
INDICATE SFC/BNDRY LYR WINDS HAVE SHIFTED TO THE S...STILL HOLDING
ARND 20KTS WITH GUSTS ARND 30KTS. LITTLE CHANGE TO SEAS...6-8FT
NEARSHORE AND 8-10FT OFFSHORE WITH DOMINANT PDS AOB 8SEC. STORM
SYSTEM LIFTING INTO THE DEEP SOUTH WILL FORCE SFC/BNDRY LYR WINDS TO
VEER SW OVERNIGHT...INCREASING TO GALE/NEAR GALE FORCE N OF THE CAPE
AFT SUNSET. SCA/GALE WARNING TIMING AND CONFIGURATION LOOK GOOD.
WED-WED NIGHT...(PREV DISC)
DEEPENING LOW PRESSURE SYSTEM WILL MOVE ACROSS N FLORIDA AND UP THE
EASTERN SEABOARD EARLY ON WEDNESDAY WITH A COLD FRONT SWEEPING
THROUGH THE STATE BEFORE MIDDAY. SOUTHWEST-WEST WINDS WILL BE
STRONGEST EARLY IN THE DAY WITH THE LOW AT ITS CLOSEST APPROACH WITH
SPEEDS 25-30KTS NORTH OF THE CAPE AND 20-25KTS SOUTH. WITH FREQUENT
GUSTS TO GALE FORCE EXPECTED...A GALE WARNING WILL BE HOISTED FOR
THE OFFSHORE WATERS NORTH OF SEBASTIAN INLET THROUGH MIDDAY. WINDS
SLOWLY DECREASE THROUGH THE AFTERNOON BECOMING NW 15-20KTS BY THE
EVENING...AND NORTH OVERNIGHT.
SEAS 4-6FT NEARSHORE AND 7-9FT OFFSHORE EARLY...SLOWLY DIMINISHING
TO 4-7FT BY LATE NIGHT. THE PREVAILING OFFSHORE WIND COMPONENT WILL
GENERATE ROUGH AND HAZARDOUS SHORT PERIOD SEAS OVER THE OPEN ATLC
WITHIN A FEW MILES OF SHORE. ROUGH CONDITIONS WILL CONTINUE
OVERNIGHT DUE TO THE OPPOSING DIRECTIONS OF THE NRLY WIND AND THE
SRLY GULF STREAM.
THU-SUN...(PREV DISC)
SURFACE HIGH BUILDING ACROSS THE DEEP SOUTH BEHIND THE FRONT WILL BE
DOMINANT FEATURE THROUGH THE END OF THE WEEK INTO THE WEEKEND. NORTH
WINDS EARLY ON THURS BECOME NORTHEAST BY THE AFTERNOON...BEFORE
VEERING TO THE EAST-NORTHEAST FRI-SUNDAY. SPEEDS GENERALLY
15-20KTS.
INCREASING ONSHORE COMPONENT TO THE FLOW WILL PUSH A STEADY SWELL
INTO THE COAST WITH SEAS 4-6FT ON FRIDAY BUILDING TO 8-9FT OFFSHORE
BY SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 64 67 40 64 / 90 20 0 10
MCO 65 69 40 66 / 90 10 0 0
MLB 68 71 46 68 / 90 30 0 10
VRB 71 73 46 69 / 80 40 0 10
LEE 61 66 36 64 / 90 10 0 0
SFB 65 68 38 65 / 90 10 0 0
ORL 64 68 40 66 / 90 10 0 0
FPR 71 73 46 69 / 80 40 0 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR COASTAL
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20
NM-COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO SEBASTIAN
INLET OUT 20 NM-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20
TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60
NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FROM 1 PM TO 7 PM EST WEDNESDAY FOR WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60
NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST WEDNESDAY FOR
WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20
TO 60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE
TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
345 PM EST TUE NOV 26 2013
...ISOLATED SEVERE WEATHER POSSIBLE THIS EVENING...
...HAZARDOUS BOATING CONDITIONS THROUGH WEDNESDAY NIGHT...
...HIGH RISK OF RIP CURRENTS ALONG AREA BEACHES THROUGH WEDNESDAY...
...FREEZE WATCH FOR PORTIONS OF THE NATURE COAST WEDNESDAY NIGHT...
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN AMPLIFIED AND
HIGHLY ENERGETIC UPPER LEVEL PATTERN EVOLVING ACROSS THE CONUS. FLOW
RIDGES SHARPLY OVER THE PACIFIC COAST AND INTER-MOUNTAIN WEST BEFORE
DIVING BACK SOUTH INTO DEEP LONGWAVE TROUGHING COVERING THE
REMAINDER OF THE NATION. THIS LONGWAVE TROUGH IS RATHER COMPLEX WITH
BOTH A STRONG NORTHERN STREAM AND SOUTHERN STREAM IMPULSE EMBEDDED
WITHIN. THE NORTHERN STREAM ENERGY IS DROPPING QUICKLY SOUTHEASTWARD
OVER THE UPPER MIDWEST/GREAT LAKES WHILE THE SOUTHERN STREAM IMPULSE
IS CURRENTLY EJECTING EASTWARD ALONG THE NORTHERN GULF COAST.
IT IS THIS POTENT SOUTHERN STREAM IMPULSE WHICH WILL BE THE BIG
PLAYER IN OUR WEATHER OVER THE NEXT 12-24.
CURRENTLY AT THE SURFACE...THE FLORIDA PENINSULA RESIDES WITH A ZONE
OF MODERATE SOUTHEASTERLY TO SOUTHERLY FLOW WITHIN A DEFINED WARM
SECTOR SOUTH AND EAST OF A DEEPENING AREA OF LOW PRESSURE OVER
SOUTHERN AL/GA. FROM THIS LOW...A COLD FRONT TRAILS SOUTHWARD ACROSS
THE CENTRAL GULF OF MEXICO AND WILL MOVE QUICKLY EASTWARD TO CROSS
OUR FORECAST AREA LATER THIS EVENING AND EARLY MORNING HOURS.
REGIONAL RADARS SHOWING WIDESPREAD SHOWERS/THUNDERSTORMS PUSHING
TOWARD THE FLORIDA WEST COAST WITHIN THE ZONE OF IMPRESSIVE SYNOPTIC
ASCENT AHEAD OF THE APPROACHING SOUTHERN STREAM IMPULSE AND SURFACE
FOCUS AHEAD OF THE COLD FRONT. SAW SOME SUNNY BREAKS TODAY WHICH
ALLOWED DECENT SURFACE HEATING AND THE DEVELOPMENT OF SURFACE BASED
INSTABILITY. THIS INSTABILITY IS BEING REALIZED WITH A SCATTERING OF
MAINLY SHOWERS OVER THE LAND AREAS...HOWEVER THE REAL SHOW IN TERMS
OF RAIN/THUNDER IS STILL OVER THE WATER AND SCHEDULED TO REACH THE
COAST BY EARLY EVENING.
&&
.SHORT TERM (EARLY EVENING THROUGH THURSDAY NIGHT)...THE POTENTIALLY
MORE SIGNIFICANT WEATHER IS BEGINNING TO APPROACH FROM THE EASTERN
GULF OF MEXICO. AS WE HEAD INTO THE EVENING HOURS...LARGE SCALE
FORCING FOR ASCENT ASSOCIATED WITH DCVA/HEIGHT FALLS WILL OVERSPREAD
THE AREA. GFS/ECMWF BOTH SHOW A BROAD EXPANSE OF DEEP LAYER QG
FORCING IN PLACE THIS EVENING. THIS IS ONE OF THE MORE POTENT
MID/UPPER LEVEL IMPULSES THAT WE HAVE SEEN MOVE ACROSS THE NE GULF
IN SOME TIME. UPPER LEVEL PV ANOMALY ASSOCIATED WITH THIS IMPULSE IS
VERY IMPRESSIVE WITH THE DYNAMIC TROPOPAUSE FOLDED DOWN ALMOST TO
600MB RESULTING IN AN EQUALLY IMPRESSIVE MID/UPPER LEVEL JET
STRUCTURE. SURFACE LOW REFLECTION AS A RESULT SHOULD CONTINUE TO
DEEPEN THROUGH THE EVENING AHEAD OF THIS FEATURE AS IT CROSSES
INTO SOUTHERN GA. THE COLD FRONT WILL ALSO INTENSIFY/SHARPEN WITH
TIME ADDING ADDITIONAL LOWER LEVEL CONVERGENCE FOCUS. ALL THAT BEING
SAID...RAIN CHANCES ARE CATEGORICAL 80% OR HIGHER FOR JUST ABOUT ALL
COASTAL ZONES THIS EVENING AND INLAND ZONES LATE THIS EVENING INTO
THE EARLY MORNING HOURS. RAIN CHANCES WILL TAPER OFF QUICKLY WITH
THE PASSAGE OF THE COLD FRONT FROM WEST TO EAST DURING THE SECOND
HALF OF THE NIGHT AND HAVE ALL RAIN CHANCES (EVEN FOR OUR FAR
EASTERN ZONES) REMOVED BY SUNRISE TOMORROW MORNING. THE CONVECTIVE
START AND END TIMES AGREE WELL WITH THE ENSEMBLE SUITE OF
LOCAL/NATIONAL HIGH RESOLUTION MODELS AND ALSO THE HOPWRF ENSEMBLES
BEING RUN OVER THE SE CONUS TODAY.
SEVERE THREAT...DESPITE THE EXPECTED WIDESPREAD COVERAGE OF SHOWER
AND STORMS DUE TO THE STRONG SYNOPTIC FORCING...THE OVERALL SEVERE
THREAT SHOULD BE ISOLATED IN NATURE. THE STORM PREDICTION CENTER HAS
OUTLOOKED MUCH OF OUR AREA IN A SLIGHT RISK FOR SEVERE WEATHER AND
AGREE WITH THIS ASSESSMENT. A NEW TORNADO WATCH HAS JUST BEEN ISSUED
TO INCLUDE SARASOTA...MANATEE...PINELLAS...HILLSBOROUGH...POLK...
PASCO...HERNANDO...SUMTER...CITRUS...AND LEVY COUNTIES. DEEP LAYER
0-6KM BULK SHEAR (35-40KTS) AND MLCAPE ARE NOT OVERLY IMPRESSIVE...
BUT CERTAINLY SUFFICIENT FOR ORGANIZED CONVECTION. MID-LEVEL LAPSE
RATES ARE ON THE POOR SIDE FOR MUCH OF THE EVENT...HOWEVER THE LACK
OF OVERALL BUOYANCY COULD BE OFFSET SOMEWHAT BY THE TENDENCY FOR THE
UPDRAFTS TO ROTATE. LOW LEVEL JET WILL BE STRONGEST 40-50KTS OVER
THE NATURE COAST ZONES...AND THEN WEAKEN WITH SOUTHWARD EXTENSION.
ALL THAT BEING SAID...THE POTENTIAL CERTAINLY EXISTS FOR ISOLATED
SEVERE WEATHER. THE MAIN THREAT WILL BE FOR DAMAGING STRAIGHT-LINE
WINDS. AN ISOLATED TORNADO IS POSSIBLE AS WELL. THE BEST SETUP FOR
AN ISOLATED TORNADO LOOKS TO EXIST ALONG THE I-4 CORRIDOR AND
NORTHWARD THROUGH THE NATURE COAST ZONES WHERE THE MORE PRONOUNCED
LOW LEVEL JET EXISTS...RESULTING IN 0-1KM SHEAR OF 25-30KTS.
WEDNESDAY...UPPER SHORTWAVE TAKES ON AN INCREASINGLY NEGATIVE TILT
AND ROTATES TO THE NORTHEAST OF THE AREA DURING THE MORNING HOURS.
RAIN WILL BE OVER WITH THE COLD FRONT OFF TO OUR EAST BY SUNRISE.
DEEP LAYER MOISTURE WILL ALSO QUICKLY EXIT ALLOWING FOR GENERALLY
CLEARING SKIES. HOWEVER...CAA IN THE WAKE OF THE FRONT OVER THE GULF
WILL LIKELY PRODUCE SOME COLD AIR STRATOCU THAT MAY MIGRATE ONSHORE
FROM TIME TO TIME (ESPECIALLY FROM PINELLAS COUNTY SOUTHWARD). THOSE
TRAVELING FOR THE THANKSGIVING HOLIDAY ON WEDNESDAY ALONG I-4 OR
FLORIDA I-75 CORRIDORS SHOULD EXPERIENCE FAIR WEATHER WITH A GUSTY
NW WIND. HIGH TEMPERATURES WILL BE COOLER WITH MAINLY 60S FROM TAMPA
BAY NORTHWARD AND AROUND 70 FURTHER SOUTH. ALONG AREA BEACHES THE
STRONG ONSHORE FLOW WILL PRODUCE LARGE BREAKING WAVES AND A HIGH
RISK OF RIP CURRENTS THROUGH THE DAY.
WEDNESDAY NIGHT...
LIKELY THE COLDEST NIGHT OF THE SEASON SO FAR ON THE WAY. A VERY DRY
AIRMASS AND NORTHERLY FLOW DRAINING DOWN THE PENINSULA WILL ALLOW
FOR TEMPERATURES TO STEADILY FALL THROUGH THE NIGHT. BY DAWN ON
THANKSGIVING MORNING THE CURRENT FORECAST SHOWS WIDESPREAD LOW TEMPS
IN THE MID/UPPER 30S TO LOW 40S. COLDER LOCATIONS OF HILLSBOROUGH...
POLK...AND PASCO COUNTY MAY BRIEFLY REACH THE LOWER 30S...AND EVEN
BETTER CHANCES FOR A PERIOD OF SUB-FREEZING (UPPER 20S/LOW 30S)
FURTHER NORTH ALONG THE NATURE COAST. THE CURRENT FORECAST
TEMPERATURES ARE SEVERAL DEGREES ABOVE THE MAV GUIDANCE AS
EXPERIENCE SHOWS A COLD BIAS TO THE STATISTICAL GUIDANCE WITH
REGARDS TO ADVECTION EVENTS. EVEN WITH THIS BIAS ADJUSTMENT...A
FREEZE WATCH IS APPROPRIATE...AND HAS BEEN ISSUED FOR HERNANDO...
SUMTER...CITRUS...AND LEVY DURING THE EARLY MORNING HOURS OF
THURSDAY (THANKSGIVING MORNING).
THANKSGIVING DAY/NIGHT...
A COLD START...BUT OTHERWISE A PLEASANT HOLIDAY UPCOMING. THE
SYNOPTIC PATTERN LOOKS BENIGN WITH ZONAL FLOW ALOFT AND A NORTHEAST
LOW LEVEL FLOW ON THE SOUTH SIDE OF SURFACE RIDGING. PLENTY OF SUN
IN THE MORNING WILL GIVE WAY TO A MIX OF SUN AND CLOUDS FOR THE
AFTERNOON AND TEMPERATURES RISING INTO THE 60S FOR MOST SPOTS
(PERHAPS NEAR 70 AROUND FORT MYERS). INCREASING LOW LEVEL MOISTURE
OFF THE ATLANTIC BY THURSDAY NIGHT SHOULD PREVENT ANY FREEZE
CONCERNS AS TEMPERATURES LOOK TO BE A GOOD 5-10+ DEGREES WARMER FOR
LOWS THAN ON THURSDAY MORNING.
&&
.LONG TERM (FRIDAY-MONDAY)...
SYNOPTIC MID LEVEL PATTERN THROUGH THE WEEKEND SHOWS A ZONAL FLOW
IN PLACE FRIDAY WITH A WEAK SHORT WAVE SHIFTING THROUGH THE
PENINSULA ON SATURDAY. ECMWF IS SHOWING A MORE AMPLIFIED TROUGH
DIGGING SOUTH THROUGH THE SOUTHEAST US ON MONDAY WITH THE GFS
DEPICTING A MUCH WEAKER WAVE. AT THE SURFACE...MODELS ARE IN GOOD
AGREEMENT THROUGH SUNDAY SHOWING HIGH PRESSURE STRETCHED ACROSS
THE EAST COAST BEFORE BEING FORCED EASTWARD BY THE NEXT
APPROACHING COLD FRONT.
DRY PATTERN EXPECTED TO SETTLE IN THROUGH SUNDAY MORNING WHICH WILL
LIMIT RAIN CHANCES. EVEN WITH A MID LEVEL SHORT WAVE SHIFTING
THROUGH THE STATE ON SATURDAY STRONG SURFACE RIDGING AND LACK OF
MOISTURE WILL HELP DIMINISH CONVECTION. RIDGE BEGINS TO WEAKEN ON
SUNDAY AND MONDAY WITH THE RETURN OF A MORE SOUTHEASTERLY FLOW. AS
MOISTURE BEGINS TO ADVECT OVER THE STATE WE WILL SEE RAIN CHANCES
BEGIN TO SLIGHTLY INCREASE AT THE TAIL END OF THE LONG TERM PERIOD.
TEMPS WILL GRADUALLY INCREASE TO MORE SEASONAL VALUES THROUGH
WEEKEND.
&&
.AVIATION...
BKN CIGS WITH VCNTY SHRA OR TSRA THIS AFTERNOON GIVE WAY TO MVFR IN
TSRA BEGINNING 00Z-04Z...WITH OCNL IFR...AND ENDING 06Z-08Z. VCNTY
SHRA OR -RA BECOME JUST BKN VFR CIGS AFTER 12Z. GUSTY SOUTHERLY
WINDS GRADUALLY SHIFT TO WESTERLY BY SUNRISE.
&&
.MARINE...
LOW PRESSURE WILL PASS TO OUR NORTH ACROSS SOUTHERN ALABAMA AND
GEORGIA THIS EVENING...AND TO THE MID ATLANTIC STATES BY WEDNESDAY.
A STRONG COLD FRONT TRAILING FROM THIS LOW WILL MOVE ACROSS THE
EASTERN GULF OF MEXICO THIS EVENING AND OVERNIGHT. WINDS WILL SHIFT
NORTHWEST IN THE WAKE OF THE FRONT WITH GUSTS TO GALE FORCE POSSIBLE
AFTER MIDNIGHT THROUGH WEDNESDAY MORNING. HIGH PRESSURE WILL ALSO
BUILD NORTH OF THE AREA IN THE WAKE OF THE FRONT AND REMAIN IN PLACE
THROUGH FRIDAY. WINDS AND SEAS WILL REMAIN NEAR ADVISORY CONDITIONS
THROUGH FRIDAY DUE TO A TIGHT PRESSURE GRADIENT TO THE SOUTH OF THE
HIGH CENTER.
&&
.FIRE WEATHER...
A STRONG COLD FRONT WILL CROSS THE REGION OVERNIGHT WITH A MUCH
COOLER AND DRIER AIRMASS ARRIVING DURING THE DAY ON WEDNESDAY. WINDS
WILL BE QUITE GUSTY FROM THE NORTHWEST DURING WEDNESDAY RESULTING IN
HIGH DISPERSION INDICES ACROSS THE FORECAST AREA. HOWEVER...AT THIS
TIME...NO CRITICAL LEVELS OF RELATIVE HUMIDITY ARE ANTICIPATED.
WINDS WILL BECOME LESS GUSTY FROM THE NORTHEAST ON THURSDAY AND A
BRIEF PERIOD OF RELATIVE HUMIDITY BELOW 35 PERCENT IS POSSIBLE
DURING THE AFTERNOON...ESPECIALLY TO THE NORTH OF THE I-4 CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 66 69 39 67 / 100 10 0 0
FMY 70 74 43 71 / 90 10 0 0
GIF 63 69 37 68 / 90 10 0 0
SRQ 66 71 42 67 / 90 10 0 0
BKV 62 67 34 66 / 100 10 0 0
SPG 66 69 46 66 / 100 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THURSDAY MORNING FOR CHARLOTTE-
HILLSBOROUGH-LEE-MANATEE-PINELLAS-SARASOTA.
HIGH SURF ADVISORY UNTIL 7 AM EST THURSDAY FOR CHARLOTTE-
HILLSBOROUGH-LEE-MANATEE-PINELLAS-SARASOTA.
FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
MORNING FOR CITRUS-HERNANDO-LEVY-SUMTER.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR BONITA
BEACH TO ENGLEWOOD OUT 20 NM-BONITA BEACH TO
ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO TARPON SPRINGS
OUT 20 NM-ENGLEWOOD TO TARPON SPRINGS OUT 20 TO 60 NM-
TARPON SPRINGS TO SUWANNEE RIVER OUT 20 NM-TARPON
SPRINGS TO SUWANNEE RIVER OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 10 PM EST WEDNESDAY FOR TAMPA
BAY WATERS.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...RUDE
LONG TERM...BARRON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 PM EST TUE NOV 26 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 505 PM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS REVEALS A WELL-DEFINED MID/UPPER LEVEL
SHORTWAVE ROTATING EAST ACROSS THE UPPER GREAT LAKES THIS AFTERNOON.
AT THE SFC...LOW PRES WAS LOCATED OVER NRN LAKE HURON WITH A COLD
FRONT EXTENDING SE THROUGH LOWER MI AND A TROUGH STRETCHING TO THE
NORTHWEST OVER NRN ONTARIO. 700-300 QVECTOR CONV OUT AHEAD
OF THE SHRTWV SUPPORTED AN AREA OF SHSN ACROSS WEST AND CNTRL UPPER
MI EARLIER TODAY WITH SOME HEAVIER LES REPORTED ALONG AND BEHIND
INITIAL FRONTAL PASSAGE. SOME AREAS NEAR WAKEFIELD/BESSEMER REPORTED
8-9 INCHES OF LAKE ENHANCED SNOW ALREADY FROM THE SNOW THAT STARTED
EARLY THIS MORNING WHILE MODERATE TO HEAVY LES WAS ALSO REPORTED
OVER PORTIONS OF HOUGHTON...NW MQT AND WRN ALGER COUNTIES.
EXPECT LES TO CONTINUE MODERATE TO HEAVY AT TIMES TONIGHT INTO
WEDNESDAY AS THE TROUGH JUST NORTH OF LAKE SUPERIOR MOVES SOUTH
ACROSS THE AREA LATE THIS EVENING AND SHIFTS WINDS FROM NW TO MORE
NNE DIRECTION OVER LAKE SUPERIOR. THIS WILL PUSH HEAVIER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY WITH ANOTHER DOMINANT
BAND LIKELY SETTING UP OVER THE PORCUPINE MTNS/IRONWOOD AREA. MOST
OF THE MODELS SUGGEST THAT THIS WILL OCCUR JUST AFT 00Z WHEN THE MID
LEVEL TROUGH AXIS MOVES INTO ERN UPPER MI. EXPECT THE GREATEST
SNOWFALL RATES NEAR MARQUETTE LATE THIS EVENING SHIFTING INTO THE
HIGHER TERRAIN WEST OF MARQUETTE OVERNIGHT INTO WEDNESDAY AS THE
UPSLOPE COMPONENT STRENGTHENS. OVER THE WEST...THE STRONGEST LOW
LEVEL CONV IS EXPECTED INTO IRONWOOD/WAKEFIELD/BERGLAND/PORCUPINE
MTNS WITH SNOWBANDS ORIGINATING NEAR THUNDER BAY AND PERHAPS
CONNECTING WITH LAKE NIPIGON IN STRONG MOIST CYCLONIC NNE FLOW. WITH
BUFR SNDGS INDICATING THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH
OF THE EVENT...EXPECT SLR VALUES IN THE 25/1 RANGE ARE EXPECTED.
THERE MAY ALSO BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE
WINDS MAY GUST TO AROUND 30 MPH. THE SNOW AND BLOWING SNOW WILL MAKE
ROADS HAZARDOUS AND TRAVEL DIFFICULT TONIGHT INTO WEDNESDAY.
THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO 7
INCH RANGE OVER THE HIGHER TERRAIN OF WRN MQT COUNTY AND FROM WHITE
PINE TO BERGLAND WEST TO IRONWOOD. WEDNESDAY....EXPECT ANOTHER 2-4
OF SNOW OVER GOGEBIC-ONTONAGON COUNTIES WITH ANOTHER 3-6 INCHES OVER
THE HIGHER TERRAIN OF WRN MQT COUNTY. GIVEN EXPECTED AMOUNTS AND
BLOWING SNOW POTENTIAL HAVE DECIDED TO UPGRADE GOGEBIC-ONTONAGON TO
AN LES WARNING THROUGH 18Z WED WHILE I ALSO UPGRADED MQT TO LES
WARNING FOR TONIGHT THROUGH WEDNESDAY.
FOR NOW LEFT LES ADVISORIES GOING FOR KEWEENAW-NRN HOUGHTON INTO
TONIGHT AND FOR BARAGA COUNTIES AND ALGER COUNITES INTO WED
AFTERNOON. WRN ALGER WILL NEED TO BE CLOSELY MONITORED TONIGHT AS
HEAVIER LES BANDS COULD PUSH AMOUNTS NEAR WARNING CRITERIA.
INFLUZ OF DRIER AIR AND WEAKENING NNE FLOW SHOULD ALLOW LES TO TAPER
OFF WED AFTERNOON FROM WEST TO EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 416 PM EST TUE NOV 26 2013
UPPER MICHIGAN WILL REMAIN UNDER THE INFLUENCE OF THE MAIN LOW NEAR
HUDSON BAY THROUGH EARLY FRIDAY...WITH DISTURBANCES CONTINUING TO
SWING ACROSS THE REGION. THE THERMOMETERS OUTSIDE WILL BE BELOW
TURKEY THAWING CONDITIONS...BOTTOMING OUT IN THE TEENS FOR MOST
LOCATIONS.
THOSE WHO ENJOY SNOW WILL BE THANKFUL FOR MORE SNOW SHOWERS
THURSDAY. THE SFC LOW ACROSS SD AT 00Z THURSDAY WILL WEAKEN OVER MN
AND IA WEDNESDAY NIGHT...BEFORE SLOWLY CROSSING UPPER MI AND LAKE MI
THURSDAY INTO FRIDAY. CURRENT THINKING IS FOR THE BEST BANDS OF SNOW
TO BE OFF-SHORE OVER W LAKE SUPERIOR...STRETCHING THROUGH KEWEENAW
COUNTY AND TROUGH S CENTRAL LAKE SUPERIOR. COULD HAVE 2-5IN OF LAKE
EFFECT SNOW FOR KEWEENAW COUNTY. THE NAM AND OTHER SMALLER SCALE
MODELS ARE A LITTLE MORE BULLISH ON THE SNOW/QPF ACCUMULATION OVER
THE TIP OF THE KEWEENAW PENINSULA. MAY NEED AN ADVISORY IF CURRENT
THINKING REMAINS.
OTHERWISE...FRIDAY WILL BE MARKED BY WAA. LEFTOVER POCKETS OF COLD
AIR FRIDAY WILL KEEP TEMPERATURES MAXING OUT IN THE MID TO UPPER
20S. 850MB TEMPS SHOULD RISE INTO THE -7 TO -13C RANGE BY 00Z
SATURDAY. THE 500MB RIDGE BUILDING IN FRIDAY AFTERNOON AND EVENING
WILL BE SHORT LIVED. THE NEXT TROUGH SET UP FROM MANITOBA THROUGH
THE N PLAINS AT 06Z SATURDAY SHOULD SLOWLY EDGE ACROSS MANITOBA AND
THE UPPER GREAT LAKES SATURDAY THROUGH EARLY SUNDAY. WHILE POPS WILL
INCREASE BACK TO CHANCES AGAIN SATURDAY INTO SATURDAY NIGHT THERE
LOOKS TO BE LITTLE MOISTURE TO WORK WITH...GIVEN THE ORIGIN OF THE
DISTURBANCE.
EXPECT BREEZY CONDITIONS E ON SATURDAY...WITH WINDS JUST ABOVE THE
SFC OUT OF THE SSW AROUND 40-45KTS. SFC TEMPS SHOULD RETURN TO THE
30S CWA WIDE FOR THE 1ST TIME SINCE MONDAY. THE NEXT CLIPPER-LIKE
SYSTEM SHOULD BE SWINGING IN FROM THE NW SATURDAY AFTERNOON. TIMING
IS STILL A CONCERN...WITH THE 12Z RUNS OF THE ECMWF AND GFS
DIFFERING BY 350MI AT 18Z SATURDAY. THE ECMWF HAS IT ACROSS S
CENTRAL ONTARIO...WHILE THE LOW OFF THE GFS IS NEAR THE
MANITOBA/ONTARIO BORDER. OF MORE OF A CONCERN IS THEIR HANDLING OF
THE NEXT...MORE SIGNIFICANT LOOKING SYSTEM...IN THE FORM OF A 500MB
LOW SINKING ACROSS THE PACIFIC NW MONDAY. STILL...THE IMPACTS OF
THAT ONE WILL NOT REALLY BE NOTICED UNTIL CLOSER TO MID WEEK...WITH
THE ASSOCIATED SFC LOW PUSHING ACROSS THE PLAINS STATES TUESDAY AS
THE 500MB LOW SLIDES ACROSS MT. WILL HAVE TO WAIT TO SEE WHAT SORT
OF IMPACTS THIS ONE WILL HAVE ACROSS THE UPPER GREAT LAKES OVER THE
NEXT FEW DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE NOV 26 2013
KCMX...EXPECT IFR CONDITIONS THROUGH MUCH OF THE PERIOD IN LAKE
EFFECT SNOW AND SOME BLOWING OF SNOW DUE TO WINDS GUSTING NEAR 25
MPH. WINDS WILL SHIFT FROM NW TO N LATER THIS EVENING CONTINUING INTO
WEDNESDAY.
KIWD...EXPECT MVFR CONDITIONS TO OCCASIONAL IFR CONDITIONS TODAY IN
NW FLOW LAKE EFFECT. CONDITIONS WILL DETERIORATE TO LIFR LATER THIS
EVENING AS WINDS SHIFT NORTHERLY AND LAKE EFFECT SNOW INCREASES.
KSAW....MVFR CONDITIONS IN SCT LAKE EFFECT SNOW WILL DETERIORATE TO
IFR AND PERHAPS EVEN OCCASIONALLY LIFR LATE TONIGHT INTO WEDNESDAY AS
WINDS SHIFT FROM NW TO N AS LAKE EFFECT SNOW INCREASES IN INTENSITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE NOV 26 2013
WEAK LOW PRESSURE OVER S ONTARIO WILL MOVE E OVERNIGHT AS HIGH
PRESSURE OVER THE N PLAINS TONIGHT SLIDES INTO THE GREAT LAKES
REGION...WEAKENING SLIGHTLY BY WEDNESDAY AFTERNOON. IN BETWEEN THESE
2 SYSTEMS...N GALES TO 35KTS ARE EXPECTED OVER MAINLY CENTRAL AND E
LAKE SUPERIOR TONIGHT...CONTINUING WITH MAINLY GALE FORCE GUSTS
WEDNESDAY OVER E PORTIONS OF LAKE SUPERIOR.
LOW PRESSURE OVER THE SE U.S. TONIGHT WILL MOVE NORTHEASTWARD INTO
THE NEW ENGLAND STATES BY WEDNESDAY EVENING WHILE DEEPENING...WHICH
WILL KEEP A TROUGH OVER THE LOWER LAKES. FOR THURSDAY INTO
FRIDAY...ANOTHER WEAK TROUGH SHOULD CROSS LAKE SUPERIOR...MERGING
WITH A HIGH OVER LAKE ONTARIO BY FRIDAY EVENING. AS THE HIGH MOVES E
TOWARDS THE ATLANTIC SATURDAY AFTERNOON INTO SUNDAY...ANOTHER WEAK
TROUGH WILL CROSS LAKE SUPERIOR. ANOTHER PERIOD OF STRONGER
WINDS...OUT OF THE S NEAR 30KTS...WILL BE POSSIBLE SATURDAY OVER
MAINLY E LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ WEDNESDAY FOR
MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST WEDNESDAY FOR MIZ004-
006.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING FROM MIDNIGHT TONIGHT TO 1 PM EST WEDNESDAY FOR
LSZ266-267.
GALE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM MIDNIGHT TONIGHT TO 5 AM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 PM EST TUE NOV 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A WELL DEFINED UPSTREAM
MID/UPPER LEVEL LOW/SHORTWAVE TROUGH FROM NW OF LAKE SUPERIOR INTO
NW MN. AT THE SFC...LOW PRES WAS LOCATED NE OF LAKE SUPERIOR(NEAR
WAWA ONTARIO) WITH A COLD FRONT EXTENDING THROUGH WHITEFISH BAY INTO
NW LOWER MI AND A TROUGH STRETCHING TO THE WEST. 700-300 QVECTOR
CONV AHEAD OF THE SHRTWV SUPPORTED SCT -SHSN/FLURRIES FROM NE MN
INTO CNTRL UPPER MI. RADAR ALSO INDICATED AN INCREASE IN LES FROM
FROM NEAR BIG BAY EASTWARD ALIGNED WITH 280-290 LOW LEVEL FLOW.
HOWEVER...WEBCAMS AND SFC OBS OVER WRN UPPER MI DID NOT SHOW A
SIGNFICANT INCREASE IN SNOW INTENSITY OVERNIGHT.
TODAY...EXPECT LES TO INCREASE THIS MORNING OVER THE WEST AS THE MID
LEVEL LOW SLIDES TO THE SOUTHEAST WITH 850/700 MB TEMPS DROPPING TO
-17C/-25C...INCREASING 850-700 MOISTURE AND CLIMBING INVERSION
HEIGHTS. THE HIGHER RES MODELS SUGGEST THAT THE MOST FAVORABLE LOW
LEVEL CONV AND HIGHER LES POTENTIAL IN THE VEERING WIND PATTERN WILL
SET UP BETWEEN TWIN LAKES AND IRONWOOD BEFORE WINDS BEOMCE MORE NNW
LATER IN THE AFTERNOON. HIGHER TERRAIN LOCATIONS SHOULD SEE SNOW
AMOUNTS IN THE 3 TO 6 INCH RANGE WITH SOME LOCALLY HIGHER AMOUNTS
POSSIBLE. OVER THE EAST...THE WNW FLOW SHOULD CONFINE THE STRONGER
LES BANDS TO AREAS NEAR THE LAKE EAST OF MUNISING.
TONIGHT...THERE IS STILL UNCERTAINTY WITH HOW QUICKLY WINDS WILL
VEER OVER THE CNTRL AND EAST WHICH WILL PUSH THE STRONGER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY. MOST OF THE MODELS SUGGEST
THAT THIS WILL OCCUR AT OR LATER THAN 00Z WHEN THE MID LEVEL TROUGH
AXIS MOVES INTO ERN UPPER MI. THE NNW WINDS ARE EXPECTED TO GRADUALLY
VEER TO THE NNE TONIGHT. SO...THE GREATEST SNOWFALL RATES NEAR
MARQUETTE ARE EXPECTED LATE THIS EVENING AND THEN WILL SHIFT INTO THE
HIGHER TERRAIN TO THE WEST AS THE UPSLOPE COMPONENT STRENGTHENS. OVER
THE WEST...THE STRONGEST LOW LEVEL CONV IS EXPECTED INTO
IRONWOOD/WAKEFIELD/BERGLANDWITH SNOWBANDS ORIGINATING NEAR THUNDER
BAY. THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO
6 INCH RANGE.
WITH THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH OF THE
EVENT...SLR VALUES IN THE 20-25/1 RANGE ARE EXPECTED. THERE MAY ALSO
BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE WINDS MAY GUST
TO AROUND 30 MPH. ALTHOUGH THE SNOW MAY SLOW TRAVEL AND MAKE ROADS
HAZARDOUS BUT OVERALL IMPACTS ARE NOT EXPECTED TO BE SEVERE.
SO...GOING LES ADVISORY LEVEL HEADLINES FOR THE NORTHERN CWA IS ON
TRACK.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 416 PM EST TUE NOV 26 2013
UPPER MICHIGAN WILL REMAIN UNDER THE INFLUENCE OF THE MAIN LOW NEAR
HUDSON BAY THROUGH EARLY FRIDAY...WITH DISTURBANCES CONTINUING TO
SWING ACROSS THE REGION. THE THERMOMETERS OUTSIDE WILL BE BELOW
TURKEY THAWING CONDITIONS...BOTTOMING OUT IN THE TEENS FOR MOST
LOCATIONS.
THOSE WHO ENJOY SNOW WILL BE THANKFUL FOR MORE SNOW SHOWERS
THURSDAY. THE SFC LOW ACROSS SD AT 00Z THURSDAY WILL WEAKEN OVER MN
AND IA WEDNESDAY NIGHT...BEFORE SLOWLY CROSSING UPPER MI AND LAKE MI
THURSDAY INTO FRIDAY. CURRENT THINKING IS FOR THE BEST BANDS OF SNOW
TO BE OFF-SHORE OVER W LAKE SUPERIOR...STRETCHING THROUGH KEWEENAW
COUNTY AND TROUGH S CENTRAL LAKE SUPERIOR. COULD HAVE 2-5IN OF LAKE
EFFECT SNOW FOR KEWEENAW COUNTY. THE NAM AND OTHER SMALLER SCALE
MODELS ARE A LITTLE MORE BULLISH ON THE SNOW/QPF ACCUMULATION OVER
THE TIP OF THE KEWEENAW PENINSULA. MAY NEED AN ADVISORY IF CURRENT
THINKING REMAINS.
OTHERWISE...FRIDAY WILL BE MARKED BY WAA. LEFTOVER POCKETS OF COLD
AIR FRIDAY WILL KEEP TEMPERATURES MAXING OUT IN THE MID TO UPPER
20S. 850MB TEMPS SHOULD RISE INTO THE -7 TO -13C RANGE BY 00Z
SATURDAY. THE 500MB RIDGE BUILDING IN FRIDAY AFTERNOON AND EVENING
WILL BE SHORT LIVED. THE NEXT TROUGH SET UP FROM MANITOBA THROUGH
THE N PLAINS AT 06Z SATURDAY SHOULD SLOWLY EDGE ACROSS MANITOBA AND
THE UPPER GREAT LAKES SATURDAY THROUGH EARLY SUNDAY. WHILE POPS WILL
INCREASE BACK TO CHANCES AGAIN SATURDAY INTO SATURDAY NIGHT THERE
LOOKS TO BE LITTLE MOISTURE TO WORK WITH...GIVEN THE ORIGIN OF THE
DISTURBANCE.
EXPECT BREEZY CONDITIONS E ON SATURDAY...WITH WINDS JUST ABOVE THE
SFC OUT OF THE SSW AROUND 40-45KTS. SFC TEMPS SHOULD RETURN TO THE
30S CWA WIDE FOR THE 1ST TIME SINCE MONDAY. THE NEXT CLIPPER-LIKE
SYSTEM SHOULD BE SWINGING IN FROM THE NW SATURDAY AFTERNOON. TIMING
IS STILL A CONCERN...WITH THE 12Z RUNS OF THE ECMWF AND GFS
DIFFERING BY 350MI AT 18Z SATURDAY. THE ECMWF HAS IT ACROSS S
CENTRAL ONTARIO...WHILE THE LOW OFF THE GFS IS NEAR THE
MANITOBA/ONTARIO BORDER. OF MORE OF A CONCERN IS THEIR HANDLING OF
THE NEXT...MORE SIGNIFICANT LOOKING SYSTEM...IN THE FORM OF A 500MB
LOW SINKING ACROSS THE PACIFIC NW MONDAY. STILL...THE IMPACTS OF
THAT ONE WILL NOT REALLY BE NOTICED UNTIL CLOSER TO MID WEEK...WITH
THE ASSOCIATED SFC LOW PUSHING ACROSS THE PLAINS STATES TUESDAY AS
THE 500MB LOW SLIDES ACROSS MT. WILL HAVE TO WAIT TO SEE WHAT SORT
OF IMPACTS THIS ONE WILL HAVE ACROSS THE UPPER GREAT LAKES OVER THE
NEXT FEW DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE NOV 26 2013
KCMX...EXPECT IFR CONDITIONS THROUGH MUCH OF THE PERIOD IN LAKE
EFFECT SNOW AND SOME BLOWING OF SNOW DUE TO WINDS GUSTING NEAR 25
MPH. WINDS WILL SHIFT FROM NW TO N LATER THIS EVENING CONTINUING INTO
WEDNESDAY.
KIWD...EXPECT MVFR CONDITIONS TO OCCASIONAL IFR CONDITIONS TODAY IN
NW FLOW LAKE EFFECT. CONDITIONS WILL DETERIORATE TO LIFR LATER THIS
EVENING AS WINDS SHIFT NORTHERLY AND LAKE EFFECT SNOW INCREASES.
KSAW....MVFR CONDITIONS IN SCT LAKE EFFECT SNOW WILL DETERIORATE TO
IFR AND PERHAPS EVEN OCCASIONALLY LIFR LATE TONIGHT INTO WEDNESDAY AS
WINDS SHIFT FROM NW TO N AS LAKE EFFECT SNOW INCREASES IN INTENSITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE NOV 26 2013
WEAK LOW PRESSURE OVER S ONTARIO WILL MOVE E OVERNIGHT AS HIGH
PRESSURE OVER THE N PLAINS TONIGHT SLIDES INTO THE GREAT LAKES
REGION...WEAKENING SLIGHTLY BY WEDNESDAY AFTERNOON. IN BETWEEN THESE
2 SYSTEMS...N GALES TO 35KTS ARE EXPECTED OVER MAINLY CENTRAL AND E
LAKE SUPERIOR TONIGHT...CONTINUING WITH MAINLY GALE FORCE GUSTS
WEDNESDAY OVER E PORTIONS OF LAKE SUPERIOR.
LOW PRESSURE OVER THE SE U.S. TONIGHT WILL MOVE NORTHEASTWARD INTO
THE NEW ENGLAND STATES BY WEDNESDAY EVENING WHILE DEEPENING...WHICH
WILL KEEP A TROUGH OVER THE LOWER LAKES. FOR THURSDAY INTO
FRIDAY...ANOTHER WEAK TROUGH SHOULD CROSS LAKE SUPERIOR...MERGING
WITH A HIGH OVER LAKE ONTARIO BY FRIDAY EVENING. AS THE HIGH MOVES E
TOWARDS THE ATLANTIC SATURDAY AFTERNOON INTO SUNDAY...ANOTHER WEAK
TROUGH WILL CROSS LAKE SUPERIOR. ANOTHER PERIOD OF STRONGER
WINDS...OUT OF THE S NEAR 30KTS...WILL BE POSSIBLE SATURDAY OVER
MAINLY E LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ WEDNESDAY FOR
MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST WEDNESDAY FOR MIZ004-
006.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING FROM MIDNIGHT TONIGHT TO 1 PM EST WEDNESDAY FOR
LSZ266-267.
GALE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM MIDNIGHT TONIGHT TO 5 AM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
108 PM EST TUE NOV 26 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A WELL DEFINED UPSTREAM
MID/UPPER LEVEL LOW/SHORTWAVE TROUGH FROM NW OF LAKE SUPERIOR INTO
NW MN. AT THE SFC...LOW PRES WAS LOCATED NE OF LAKE SUPERIOR(NEAR
WAWA ONTARIO) WITH A COLD FRONT EXTENDING THROUGH WHITEFISH BAY INTO
NW LOWER MI AND A TROUGH STRETCHING TO THE WEST. 700-300 QVECTOR
CONV AHEAD OF THE SHRTWV SUPPORTED SCT -SHSN/FLURRIES FROM NE MN
INTO CNTRL UPPER MI. RADAR ALSO INDICATED AN INCREASE IN LES FROM
FROM NEAR BIG BAY EASTWARD ALIGNED WITH 280-290 LOW LEVEL FLOW.
HOWEVER...WEBCAMS AND SFC OBS OVER WRN UPPER MI DID NOT SHOW A
SIGNFICANT INCREASE IN SNOW INTENSITY OVERNIGHT.
TODAY...EXPECT LES TO INCREASE THIS MORNING OVER THE WEST AS THE MID
LEVEL LOW SLIDES TO THE SOUTHEAST WITH 850/700 MB TEMPS DROPPING TO
-17C/-25C...INCREASING 850-700 MOISTURE AND CLIMBING INVERSION
HEIGHTS. THE HIGHER RES MODELS SUGGEST THAT THE MOST FAVORABLE LOW
LEVEL CONV AND HIGHER LES POTENTIAL IN THE VEERING WIND PATTERN WILL
SET UP BETWEEN TWIN LAKES AND IRONWOOD BEFORE WINDS BEOMCE MORE NNW
LATER IN THE AFTERNOON. HIGHER TERRAIN LOCATIONS SHOULD SEE SNOW
AMOUNTS IN THE 3 TO 6 INCH RANGE WITH SOME LOCALLY HIGHER AMOUNTS
POSSIBLE. OVER THE EAST...THE WNW FLOW SHOULD CONFINE THE STRONGER
LES BANDS TO AREAS NEAR THE LAKE EAST OF MUNISING.
TONIGHT...THERE IS STILL UNCERTAINTY WITH HOW QUICKLY WINDS WILL
VEER OVER THE CNTRL AND EAST WHICH WILL PUSH THE STRONGER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY. MOST OF THE MODELS SUGGEST
THAT THIS WILL OCCUR AT OR LATER THAN 00Z WHEN THE MID LEVEL TROUGH
AXIS MOVES INTO ERN UPPER MI. THE NNW WINDS ARE EXPECTED TO GRADUALLY
VEER TO THE NNE TONIGHT. SO...THE GREATEST SNOWFALL RATES NEAR
MARQUETTE ARE EXPECTED LATE THIS EVENING AND THEN WILL SHIFT INTO THE
HIGHER TERRAIN TO THE WEST AS THE UPSLOPE COMPONENT STRENGTHENS. OVER
THE WEST...THE STRONGEST LOW LEVEL CONV IS EXPECTED INTO
IRONWOOD/WAKEFIELD/BERGLANDWITH SNOWBANDS ORIGINATING NEAR THUNDER
BAY. THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO
6 INCH RANGE.
WITH THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH OF THE
EVENT...SLR VALUES IN THE 20-25/1 RANGE ARE EXPECTED. THERE MAY ALSO
BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE WINDS MAY GUST
TO AROUND 30 MPH. ALTHOUGH THE SNOW MAY SLOW TRAVEL AND MAKE ROADS
HAZARDOUS BUT OVERALL IMPACTS ARE NOT EXPECTED TO BE SEVERE.
SO...GOING LES ADVISORY LEVEL HEADLINES FOR THE NORTHERN CWA IS ON
TRACK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 443 AM EST TUE NOV 26 2013
LK EFFECT COVERAGE AND INTENSITY THROUGH THANKSGIVING IS THE MAIN
FORECAST FOCUS.
IN THE LARGER SCALE TO START WEDNESDAY...SHORTWAVE TROUGH THAT
HELPED TO IGNITE LATEST ROUND OF LAKE EFFECT WILL BE CROSSING LOWER
GREAT LAKES. TROUGH EVENTUALLY MEETS UP WITH PAIR OF SHORTWAVES
PUSHING OUT OF CNTRL AND SOUTHEAST CONUS TO HELP GIN UP STRONG
LOW PRESSURE SYSTEM OVER THE MID ATLANTIC STATES. THAT SYSTEM AND
ITS RAIN/SNOW AND WIND IMPACTS WILL BE PRIME FOCUS FOR THE WEATHER
ACROSS THE CONUS.
BACK ACROSS UPR MICHIGAN...MODERATE LK EFFECT WILL BE ONGOING FOR
NORTH FLOW AREAS. THOUGH THERE IS GRADUAL LOWERING OF INVERSIONS
THROUGH THE DAY ON WEDNESDAY...NORTH WINDS PERSIST IN THE LAKE
CONVECTIVE LAYER AND IT REMAINS PLENTY COLD ENOUGH WITH TEMPS AT
INVERSION TOP OF 5-7KFT STAYING IN THAT IDEAL RANGE OF -15C TO
-20C. BUFKIT COBB OUTPUT SUGGESTS SLR/S AT IWD AND MQT POINTS
NEARING 30:1. CUT THESE SLIGHTLY THOUGH DUE TO SOME FRACTURING OF
SNOWFLAKES WITH WINDS AOA 20 KTS BLO CLOUD BASE. LK EFFECT ADVYS IN
THE SHORT TERM WILL CARRY THROUGH MIDDAY WEDNESDAY IN THE FAR WEST
AND INTO LATE AFTN FOR MARQUETTE COUNTY INTO WESTERN ALGER COUNTY.
EXPECT ADDITIONAL DAYTIME SNOW ACCUMS UP TO 5 INCHES...GREATEST
FOR THE HIGHER TERRAIN OF WESTERN MARQUETTE COUNTY WITH EXPECTED
NNE WINDS BLO 5KFT. AS AFTN WEARS ON...INTENSITY OF SNOW SHOWERS
SHOULD START TO RELAX AS H85-H7 MOISTURE THINS OUT AND LOW-LEVEL
WINDS BECOME MORE ANTICYLONIC...ESPECIALLY FOR FAR WESTERN CWA. AWAY
FM LK EFFECT SHOULD BE GENERALLY CLOUDY DAY AS SOUNDINGS SHOW H85-H8
MOISTURE DUE TO WINDS FLOWING OFF LK SUPERIOR...STAYS TRAPPED
BENEATH LARGER SCALE SUBSIDENCE WHICH IS PRETTY TYPICAL FOR THIS
TIME OF YEAR GIVEN THE LOW SUN ANGLE. TEMPS WILL BE IN THE 20S
ACROSS THE AREA.
WEAKENING LOW-LEVEL FLOW ALLOWS MESOSCALE TO BECOME MAIN DRIVER FOR
CONVERGENCE/LK EFFECT AREAS ON WEDNESDAY NIGHT. LEANED ON THE NAM AS
OUTPUT MADE A LOT OF SENSE WITH EXPECTED SFC PATTERN AND WINDS AT H9
WHICH WILL BE IN THE LAKE CLOUD-BEARING LAYER. AS RETURN FLOW TRIES
TO GET GOING AND ALSO DUE TO LAND BREEZE...MESOLOW PROBABLY FORMS BY
WED EVENING JUST ALONG SHORE FM SAXON HARBOR TO SILVER CITY. AS H9
WINDS BECOME MORE SW...EXPECT SNOW SHOWERS TO LIFT TOWARD KEWEENAW
LATE. MODERATE SNOWS MAY BE ONGOING...BUT IMPACT WOULD BE LIMITED TO
FAR WESTERN SHORE OF KEWEENAW PENINSULA. FARTHER EAST...EXPECT
SIMILAR SETUP IN THE MARQUETTE AREA. WINDS SLOWLY BACKING NRLY IN
THE EVENING LIKELY WILL PUSH SNOW SHOWERS OFF THE HIGHLANDS OF
WESTERN MARQUETTE COUNTY AND TOWARD THE LK SUPERIOR SHORE AND INTO
EASTERN PORTIONS OF MARQUETTE COUNTY. LAND BREEZE MAY ALLOW FOR
DECENT CONVERGENT BAND SOMEWHERE BTWN MARQUETTE/HARVEY AND AU TRAIN.
MINIMAL CHANGE IN H925-H85 TEMPS AND INVERSION HEIGHTS ON WEDNESDAY
NIGHT WOULD ALLOW FOR AT LEAST MODERATE SNOW ACCUMS WITHIN THIS
CONVERGENT AREA. THIS MAY POSE SOME PROBLEM FOR THE ENDING OF THE
HEADLINE ON WEDNESDAY AFTN...BUT WILL LET LATER SHIFTS EXTEND THE
ADVY IF IT IS NEEDED AS DO NOT KNOW EXACTLY WHERE THE HEAVIER SNOW
WOULD END UP. POSSIBLE THAT BAND OF SNOW WILL STILL BE AROUND FOR
DAYBREAK ON THANKSGIVING...BUT THINK THAT THE RETURN FLOW OVER THE
WEST WILL MAKE ITS WAY EAST AND KICK THE MAIN SNOW SHOWERS OUT
ACROSS LK SUPERIOR. SOUNDINGS SHOW INCREASE IN MID-LEVEL MOISTURE
LATE WEDNESDAY NIGHT AS ANOTHER SHORTWAVE DROPS ACROSS UPR LAKES IN
NW FLOW. SMALL POPS AWAY FM LK EFFECT AREAS LATE IN THE WEST TO
ACCOUNT FOR THE SHORTWAVE.
SHORTWAVE CROSSES THE AREA ON THANKSGIVING...MAINLY THROUGH MID AFTN.
ALSO A BIT OF A WEAK SFC TROUGH TOO. SOUNDINGS SHOW DECENT LIFT
OCCURRING FM H9-H7 WHICH IS FIRMLY WHERE THE DGZ RESIDES. EVEN WITH
A BIT OF DRY AIR BLO H85...THINK THE LIFT AND MOISTENING FM ABOVE
WILL BE ENOUGH TO PRODUCE LGT SNOW OVER MUCH OF THE CWA...EXCEPT
MAYBE THE FAR SCNTRL. AMOUNTS WILL BE LESS THAN AN INCH. ONE
EXCEPTION TO THAT COULD BE OVER THE KEWEENAW WHERE ONSHORE
FLOW/CONVERGENCE COULD BOOST SNOW AMOUNTS ALONG TIP OF THE KEWEENAW.
NOT EXPECTING ANY HEADLINE AMOUNTS THOUGH AS WIND FIELDS ARE PRETTY
VARIABLE INDICATING SNOW SHOWERS WILL NOT REMAIN IN ANY ONE LOCATION
VERY LONG. LATEST RUNS SHOW ENOUGH OF SW PUSH IN AFTN TO ADVECT SNOW
SHOWERS OUT OVER NCNTRL LK SUPERIOR. GFS/ECMWF INDICATE LOW PRESSURE
TROUGH THAT IS LEFT BEHIND IN WAKE OF SHORTWAVE SHOULD SINK BACK INTO
AT LEAST NORTHWEST CWA LATER THURSDAY NIGHT. CHANCE POPS FOR SNOW
SHOWERS WERE CARRIED FOR THAT TIME AND INTO FRIDAY AS WELL. EXPECTED
N FLOW IN WAKE OF TROUGH ALSO RESULTED IN LOWER CHANCES LINGERING
INTO NCNTRL CWA. TROUGH AND ANY LINGERING SNOW SHOWERS DISSIPATE BY
FRIDAY EVENING AS PRESSURE GRADIENT REGROUPS AHEAD OF DEVELOPING
TROUGH OVR SCNTRL CANADA.
SHORTWAVE AND SFC TROUGH STAY MAINLY TO THE NORTH OF UPR LAKES FOR
THE UPCOMING WEEKEND. BEST SHOT OF LGT SNOW WILL BE OVR LK SUPERIOR
ON SATURDAY CLOSER TO THE SHORTWAVE/Q-VECTOR CONVERGENCE AND MORE
SATURATED LOW-LEVELS. A LOT OF CLOUD COVER OVER REST OF CWA ALONG
WITH BREEZY SOUTH WIND THAT WILL BRING A RETURN OF SLIGHTLY ABOVE
FREEZING TEMPS OVER MUCH OF CWA. RAN WITH CONSENSUS BEYOND SATURDAY
WITH DIFFERENCES SHOWING UP IN HOW QUICK TO BRING NEXT SHORTWAVE AND
SFC TROUGH/PRECIP INTO UPR LAKES. DOES LOOK LIKE TEMPS WILL STAY
RELATIVELY WARMER /HIGHS IN THE 30S COMPARED TO TEENS OR 20S/ BEFORE
ANOTHER PUSH OF COLDER AIR ARRIVES JUST BEYOND THE SCOPE OF THE LONG
TERM TIME RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1242 PM EST TUE NOV 26 2013
KCMX...EXPECT IFR CONDITIONS THROUGH MUCH OF THE PERIOD IN LAKE
EFFECT SNOW AND SOME BLOWING OF SNOW DUE TO WINDS GUSTING NEAR 25
MPH. WINDS WILL SHIFT FROM NW TO N LATER THIS EVENING CONTINUING INTO
WEDNESDAY.
KIWD...EXPECT MVFR CONDITIONS TO OCCASIONAL IFR CONDITIONS TODAY IN
NW FLOW LAKE EFFECT. CONDITIONS WILL DETERIORATE TO LIFR LATER THIS
EVENING AS WINDS SHIFT NORTHERLY AND LAKE EFFECT SNOW INCREASES.
KSAW....MVFR CONDITIONS IN SCT LAKE EFFECT SNOW WILL DETERIORATE TO
IFR AND PERHAPS EVEN OCCASIONALLY LIFR LATE TONIGHT INTO WEDNESDAY AS
WINDS SHIFT FROM NW TO N AS LAKE EFFECT SNOW INCREASES IN INTENSITY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EST TUE NOV 26 2013
NW WINDS TO 30 KTS TODAY AS WE ARE IN THE WAKE OF COLD FRONT THAT
MOVED THROUGH MONDAY EVENING. ANOTHER TROUGH DROPS SOUTH ACROSS LK
SUPERIOR LATE TODAY AND THIS EVENING RESULTING IN WINDS SHIFTING TO
NORTH OR NORTHEAST. GALES LOOK LIKELY OVER MAINLY EAST HALF SO GALE
WARNING HAS BEEN POSTED. GALES LINGER INTO WEDNESDAY BEFORE WINDS
QUICKLY DIMINISH TO LESS THAN 20 KTS AS WEAK PRESSURE GRADIENT
DEVELOPS FOR THANKSGIVING. WINDS STAY LIGHT UNTIL SATURDAY WHEN
SOUTH WINDS INCREASE AHEAD OF LOW PRESSURE SYSTEM CROSSING SCNTRL
CANADA. WINDS MAY REACH 30 KTS OVER EASTERN SECTIONS INTO SATURDAY
EVENING. MORE LIGHT WINDS TO END THE WEEKEND AS PRESSURE GRADIENT
RELAXES AGAIN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 3 PM EST
WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL NOON EST /11 AM CST/ WEDNESDAY
FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ004-
084.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST WEDNESDAY FOR MIZ006.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 1 PM EST WEDNESDAY FOR LSZ266-267.
GALE WARNING FROM 1 AM TO 10 AM EST WEDNESDAY FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...VOSS
MARINE...JLA
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1215 PM CST TUE NOV 26 2013
.DISCUSSION...
18Z AVIATION DISCUSSION.
&&
.AVIATION...
INTERESTING FORECAST THIS MORNING AS A COLD UPPER LOW DIGS DOWN
OVER THE EASTERN TEXAS/COASTAL BEND THROUGH THE DAY. THE ATMOSPHERIC
COLUMN BEGINS TO DRY THROUGH LATE AFTERNOON/EARLY EVENING...BUT
THAT WINDOW BETWEEN WHERE THERE IS JUST ENOUGH MOISTURE (OR ICE
CRYSTAL NUCLEI) IN TANDEM WITHIN ANY SUB-FREEZING LAYER OF ANY
SIGNIFICANT THICKNESS...WILL BE THE DETERMINING FACTOR AS TO
WHETHER NORTHERN HUB RECEIVE A RAIN-SNOW MIXTURE THROUGH THE
EARLY AFTERNOON. AS OF NOW...THE THERMODYNAMIC NATURE OF THE
PROGGED PROFILES OVER THE FAR NORTHERN HUBS COULD SUPPORT THIS
SCENARIO AS THE UPPER LOW PASSES BY. THE BEST CHANCE FOR ANY
FROZEN PRECIPITATION FOR SUCH HUBS AS KUTS OR KCXO WILL BE BY LATE
AFTERNOON AND WOULD BE IN MIXED FORM...LIGHT RAIN OR DRIZZLE WITH
EITHER SNOW OR ICE PELLETS. THIS COULD TEMPORARILY TURN OVER TO
ALL SNOW OVER THE EXTREME NORTHERN TERMINALS (KUTS). A LOW FREEZING
LINE...AND A FAIRLY-SATURATED BELOW FREEZING COLUMN UP THROUGH
THE UPPER ATMOSPHERE DUE TO WRAP-AROUND MOISTURE...MAKES FOR A
HIGHER POTENTIAL FOR AIRCRAFT ICE RIMING THROUGH THIS EVENING.
AS THE UPPER LOW EXITS EAST...DECKS WILL GRADUALLY LIFT TO MVFR
THROUGH EARLY EVENING TO MAINLY SKY CLEAR/SCT250 BY MIDNIGHT. A
VERY TIGHT OFFSHORE PRESSURE GRADIENT WILL MAKE FOR MODERATE
NORTHWESTERN INTERIOR WINDS...STRONG ALONG THE IMMEDIATE COAST
THROUGH THE PERIOD. 31
&&
.PREV DISCUSSION... /ISSUED 1006 AM CST TUE NOV 26 2013/
UPDATE...
SEE MORNING UPDATE.
DISCUSSION...
12Z DATA SHOWS THE UPPER LEVEL TROUGH AXIS STILL TO THE WEST WITH
SOME WEAK DIVERGENCE NOTED OVER EAST TEXAS. MOISTURE STILL LOOKS
RATHER PLENTIFUL AT 850 AND 700 MB. THE FREEZING LINE AT 850 MB
EXTENDS ACROSS THE WESTERN HALF OF SE TX. SHORT TERM GUIDANCE
SUGGESTS THAT MSTR WILL LINGER A BIT LONGER THAN EXPECTED
YESTERDAY AND FORCING FROM THE UPPER TROUGH SHOULD CONTINUE TO
FOSTER PERIODS OF LIGHT RAIN THROUGH EARLY AFTN. WILL BUMP POPS TO
HIGH END CHANCE FOR THE EASTERN HALF OF THE CWA. RAP AND 12Z NAM
12 SOUNDINGS SUGGEST SOME POTENTIAL FOR WINTER PRECIP OVER THE NE
QUARTER OF THE CWA. SOUNDINGS LOOK COLD ENOUGH FOR SNOW AROUND 18Z
FROM CROCKETT TO LIVINGSTON. NOT SURE HOW COLD MID LEVEL AIR WILL
BE BUT ADDED A RAIN/SNOW MIX FOR THE NE PART OF THE AREA. SURFACE
TEMPS WILL REMAIN TOO WARM FOR ANYTHING TO ACCUMULATE. NEW ZONES
OUT BY 1030 AM. 43
&&
PREV DISCUSSION... /ISSUED 434 AM CST TUE NOV 26 2013/
DISCUSSION...
THE LARGE AREA OF PRECIPITATION THAT HAS LINGERED ACROSS SOUTHEAST
TEXAS SINCE EARLY MONDAY IS BEGINNING TO SHIFT OFF TO THE EAST
WITH THE APPROACH OF THE MAIN UPPER LEVEL LOW. THIS SYSTEM IS
DIGGING SOUTHWARD ACROSS THE SOUTH PLAINS AND APPROACHING THE HILL
COUNTRY THIS MORNING. OF GREATEST CONCERN THIS MORNING IS THE
POTENTIAL FOR SOME WINTRY PRECIPITATION TO MIX IN WITH THE RAIN AS
THE LOW BRINGS COOLER TEMPERATURES ALOFT INTO THE REGION. A 09Z
SOUNDING FROM COLLEGE STATION SHOWS A WARM NOSE AT 800MB WITH A
WARM LAYER OF APPROXIMATELY 3KFT. BELOW THIS LAYER TEMPERATURES
FALL BACK BELOW FREEZING FOR 3KFT BEFORE RISING ABOVE FREEZING
AGAIN IN THE LAST 800 FEET. THIS SUPPORTS THE CURRENT FORECAST
REASONING WHICH IS FOR RAIN WITH SOME SLIGHT CHANCE FOR SLEET
MIXED IN ALONG AND NORTH OF A LINE FROM CALDWELL TO LIVINGSTON.
WITH SURFACE TEMPERATURES IN THE UPPER 30S NO ACCUMULATION IS
EXPECTED ACROSS THIS AREA. FURTHER SOUTH...PRECIPITATION WILL
REMAIN AS RAIN. AS THE MAIN UPPER LOW APPROACHES WE COULD BRIEFLY
SEE THE POTENTIAL FOR A FEW SNOW FLURRIES TO MIX IN WITH THE RAIN
AS TEMPERATURES ALOFT BEGIN TO COOL...BUT THIS IS NOT LIKELY TO
OCCUR BEFORE THE MOISTURE SHIFTS OFF TO OUR EAST AND PRECIPITATION
ENDS ACROSS THE REGION.
THE UPPER LOW WILL CROSS THE REGION TODAY BRINGING DRIER AND
COOLER AIR IN ITS WAKE. UNSEASONABLY COLD TEMPERATURES ARE
EXPECTED WEDNESDAY AND THURSDAY MORNINGS WITH A LIGHT FREEZE
EXPECTED ACROSS THE NORTHERN HALF OF THE REGION. A SLOW WARMING
TREND WILL BEGIN LATE IN THE WEEK THROUGH THE WEEKEND AS HIGH
PRESSURE EXITS THE REGION AND ONSHORE FLOW RESUMES. NEXT CHANCE
FOR RAIN WILL BE LATE THIS WEEKEND AS A WEAK DISTURBANCE MOVES
ACROSS THE REGION. 38
&&
MARINE...
STRONG NORTH TO NORTHWEST WINDS AND ROUGH SEAS WILL CONTINUE THROUGH
TONIGHT AS AN INTENSE UPPER LEVEL LOW PRESSURE SYSTEM MOVES THROUGH
THE UPPER TEXAS COASTAL WATERS. SMALL CRAFT ADVISORIES REMAIN IN
EFFECT...AND WIND GUSTS TO GALE FORCE WILL BE POSSIBLE. CONDITIONS
WILL BEGIN TO IMPROVE ON WEDNESDAY AS SURFACE HIGH PRESSURE BUILDS
INTO THE AREA...WINDS TURN TO THE NORTHEAST...AND SEAS COME DOWN.
LIGHT TO MODERATE NORTHEAST TO EAST WINDS ARE ANTICIPATED BEGINNING
ON THURSDAY AND CONTINUING INTO EARLY SATURDAY. A STRENGTHENING
ONSHORE FLOW IS IN THE FORECAST FOR THE END OF THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 30 48 29 54 35 / 10 0 0 0 0
HOUSTON (IAH) 32 51 30 57 37 / 10 0 0 0 0
GALVESTON (GLS) 42 50 42 57 50 / 10 0 0 0 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...JACKSON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1006 AM CST TUE NOV 26 2013
.UPDATE...
SEE MORNING UPDATE.
&&
.DISCUSSION...
12Z DATA SHOWS THE UPPER LEVEL TROUGH AXIS STILL TO THE WEST WITH
SOME WEAK DIVERGENCE NOTED OVER EAST TEXAS. MOISTURE STILL LOOKS
RATHER PLENTIFUL AT 850 AND 700 MB. THE FREEZING LINE AT 850 MB
EXTENDS ACROSS THE WESTERN HALF OF SE TX. SHORT TERM GUIDANCE
SUGGESTS THAT MSTR WILL LINGER A BIT LONGER THAN EXPECTED
YESTERDAY AND FORCING FROM THE UPPER TROUGH SHOULD CONTINUE TO
FOSTER PERIODS OF LIGHT RAIN THROUGH EARLY AFTN. WILL BUMP POPS TO
HIGH END CHANCE FOR THE EASTERN HALF OF THE CWA. RAP AND 12Z NAM
12 SOUNDINGS SUGGEST SOME POTENTIAL FOR WINTER PRECIP OVER THE NE
QUARTER OF THE CWA. SOUNDINGS LOOK COLD ENOUGH FOR SNOW AROUND 18Z
FROM CROCKETT TO LIVINGSTON. NOT SURE HOW COLD MID LEVEL AIR WILL
BE BUT ADDED A RAIN/SNOW MIX FOR THE NE PART OF THE AREA. SURFACE
TEMPS WILL REMAIN TOO WARM FOR ANYTHING TO ACCUMULATE. NEW ZONES
OUT BY 1030 AM. 43
&&
.PREV DISCUSSION... /ISSUED 555 AM CST TUE NOV 26 2013/
AVIATION...
CURRENT BATCH OF -RA/RA WILL BE EAST OF OUR TAF SITES BY AROUND 14Z.
AS THE UPPER LOW CENTER MOVES ACROSS THE AREA LATER THIS MORNING THROUGH
THIS AFTERNOON...SOME HIGH RES MODELS ARE INDICATING POSSIBLE ADDITIONAL
DEVELOPMENT...ESPECIALLY BETWEEN IAH AND GLS. WILL COVER THIS CHANCE
WITH TEMPO FOR IAH AND PREVAILING FURTHER TO THE SOUTH. MVFR/IFR CEILINGS
THIS MORNING WILL BEGIN TO LIFT LATER THIS AFTERNOON WITH VFR CONDITIONS
ANTICIPATED THIS EVENING. WINDS WILL REMAIN ELEVATED FOR MUCH OF THE
DAY...ESPECIALLY NEAR THE COAST...THEN COME DOWN THIS EVENING UNDER
A RELAXING PRESSURE GRADIENT.
42
PREV DISCUSSION... /ISSUED 434 AM CST TUE NOV 26 2013/
DISCUSSION...
THE LARGE AREA OF PRECIPITATION THAT HAS LINGERED ACROSS SOUTHEAST
TEXAS SINCE EARLY MONDAY IS BEGINNING TO SHIFT OFF TO THE EAST
WITH THE APPROACH OF THE MAIN UPPER LEVEL LOW. THIS SYSTEM IS
DIGGING SOUTHWARD ACROSS THE SOUTH PLAINS AND APPROACHING THE HILL
COUNTRY THIS MORNING. OF GREATEST CONCERN THIS MORNING IS THE
POTENTIAL FOR SOME WINTRY PRECIPITATION TO MIX IN WITH THE RAIN AS
THE LOW BRINGS COOLER TEMPERATURES ALOFT INTO THE REGION. A 09Z
SOUNDING FROM COLLEGE STATION SHOWS A WARM NOSE AT 800MB WITH A
WARM LAYER OF APPROXIMATELY 3KFT. BELOW THIS LAYER TEMPERATURES
FALL BACK BELOW FREEZING FOR 3KFT BEFORE RISING ABOVE FREEZING
AGAIN IN THE LAST 800 FEET. THIS SUPPORTS THE CURRENT FORECAST
REASONING WHICH IS FOR RAIN WITH SOME SLIGHT CHANCE FOR SLEET
MIXED IN ALONG AND NORTH OF A LINE FROM CALDWELL TO LIVINGSTON.
WITH SURFACE TEMPERATURES IN THE UPPER 30S NO ACCUMULATION IS
EXPECTED ACROSS THIS AREA. FURTHER SOUTH...PRECIPITATION WILL
REMAIN AS RAIN. AS THE MAIN UPPER LOW APPROACHES WE COULD BRIEFLY
SEE THE POTENTIAL FOR A FEW SNOW FLURRIES TO MIX IN WITH THE RAIN
AS TEMPERATURES ALOFT BEGIN TO COOL...BUT THIS IS NOT LIKELY TO
OCCUR BEFORE THE MOISTURE SHIFTS OFF TO OUR EAST AND PRECIPITATION
ENDS ACROSS THE REGION.
THE UPPER LOW WILL CROSS THE REGION TODAY BRINGING DRIER AND
COOLER AIR IN ITS WAKE. UNSEASONABLY COLD TEMPERATURES ARE
EXPECTED WEDNESDAY AND THURSDAY MORNINGS WITH A LIGHT FREEZE
EXPECTED ACROSS THE NORTHERN HALF OF THE REGION. A SLOW WARMING
TREND WILL BEGIN LATE IN THE WEEK THROUGH THE WEEKEND AS HIGH
PRESSURE EXITS THE REGION AND ONSHORE FLOW RESUMES. NEXT CHANCE
FOR RAIN WILL BE LATE THIS WEEKEND AS A WEAK DISTURBANCE MOVES
ACROSS THE REGION. 38
MARINE...
STRONG NORTH TO NORTHWEST WINDS AND ROUGH SEAS WILL CONTINUE THROUGH
TONIGHT AS AN INTENSE UPPER LEVEL LOW PRESSURE SYSTEM MOVES THROUGH
THE UPPER TEXAS COASTAL WATERS. SMALL CRAFT ADVISORIES REMAIN IN
EFFECT...AND WIND GUSTS TO GALE FORCE WILL BE POSSIBLE. CONDITIONS
WILL BEGIN TO IMPROVE ON WEDNESDAY AS SURFACE HIGH PRESSURE BUILDS
INTO THE AREA...WINDS TURN TO THE NORTHEAST...AND SEAS COME DOWN.
LIGHT TO MODERATE NORTHEAST TO EAST WINDS ARE ANTICIPATED BEGINNING
ON THURSDAY AND CONTINUING INTO EARLY SATURDAY. A STRENGTHENING
ONSHORE FLOW IS IN THE FORECAST FOR THE END OF THE WEEKEND. 42
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 30 48 29 54 / 20 10 0 0 0
HOUSTON (IAH) 43 32 51 30 57 / 50 10 0 0 0
GALVESTON (GLS) 46 42 50 42 57 / 50 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...JACKSON...
MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43