Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/29/13
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1254 AM EST WED NOV 27 2013
.SYNOPSIS...
LOW PRESSURE WILL INTENSIFY AND MOVE NORTH-NORTHEAST THROUGH THE
MID ATLANTIC STATES OVERNIGHT...THEN PASS OVER THE AREA ON
WEDNESDAY...AND THEN ON 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 THIS MORNING/...
WILL LET WINTER WEATHER ADVISORY EXPIRE AT 1AM IN ORANGE
COUNTY...MESONET OBS ONLY SHOW AT MOST A POCKET OR TWO OF
TEMPERATURES AT 32 WITH EVERYPLACE OUT 33+ SO AREAL COVERAGE DOES
NOT JUSTIFY AN EXTENSION.
ON THE WHOLE ONLY MADE MINOR ADJUSTMENTS BASED ON LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE.
ELSEWHERE...RAIN WILL INCREASE IN INTENSITY OVERNIGHT 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 DIFFLUENT UPPER JET STREAK APPROACHING FROM THE WEST AS A
NORTHERN/SOUTHERN STREAMS PHASE ALOFT. THIS IS EVIDENT IN RAPID
PRESSURE FALLS THIS EVENING ACROSS THE DC AREA.
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 FLOOD WATCH CONTINUES FOR
THE POTENTIAL FOR AREAL/URBAN FLOODING AND FLOODING OF SMALL
STREAMS. SEE HYDROLOGY SECTIONS FOR MORE DETAILS.
THE LOW LEVEL JET ALSO LOOKS STRONG ENOUGH TO SUPPORT STRONG SE-S
WINDS ALONG THE COAST...SO THE WIND ADVISORY CONTINUES. VERY
STRONG NAM LOW LEVEL JET 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.
SEE TIDES AND COASTAL FLOODING SECTIONS FOR MINOR COASTAL FLOODING
AND BEACH EROSION CONCERNS.
TEMPS WILL BE ON THE RISE TONIGHT...REACHING THE MID AND UPPER 50S
BY MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
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 ADVISORY EARLIER
THAN ORIGINALLY FCST SINCE THE LOW TRACK SHOULD BE SLIGHTLY
FARTHER EAST...WITH THE LOW LEVEL JET ALSO PASSING TO THE EAST SOONER.
RAIN SHOULD LESSEN IN INTENSITY AS WELL AS AS THE LOW LEVEL JET 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 ADVISORY 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 NIGHT 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 /06Z WEDNESDAY THROUGH SUNDAY/...
**HIGH IMPACT AVIATION WEATHER EVENT FOR TONIGHT AND WEDNESDAY**
DETERIORATING CONDITIONS REST OF TONIGHT WITH AN APPROACHING LOW
PRESSURE SYSTEM. VARYING IFR/LIFR CONDITIONS THROUGH THE
MORNING...WITH GRADUAL IMPROVEMENT THIS AFTERNOON INTO TONIGHT.
WINDS INCREASING...WITH OCNL GUSTS THROUGH 07Z...AND MORE
PERSISTENT THEREAFTER QUICKLY INCREASING TO BETWEEN 20 AND 30 KT.
WIND SHEAR BECOMES AN ISSUE NYC TERMINALS AND EAST 08Z-14Z
TODAY...WITH SLY WINDS UP TO 70 KT AT 2000 FT. WINDS GRADUALLY
DIMINISH AND SHIFT TO THE SW THEN NW BY THIS AFTERNOON. TIMING OF
WIND SHIFTS MAY BE 1-2 HOURS. GUSTS WILL REMAIN ACROSS THE ENTIRE
AREA INTO TONIGHT...THOUGH A BRIEF LULL AS WINDS SHIFT FROM S TO
NW IS POSSIBLE.
EXPECT IFR AND LIFR CIGS AS HEAVIER PRECIPITATION MOVES IN THE
REST OF THE NIGHT. BEST CHANCE FOR LIFR WILL BE BETWEEN 07Z AND
15Z. PRECIPITATION LINGERS DURING THE DAY...WITH GRADUALLY
IMPROVING CIGS AFTER 15Z. PRECIPITATION SHOULD REMAIN ALL RAIN
FROM HERE ON OUT.
.OUTLOOK FOR 06Z THURSDAY THROUGH MONDAY...
.WED NIGHT. VFR. W-NW WINDS 20-25G35KT.
.THU...VFR. NW WINDS 20-25G30-35KT EARLY SLOWLY DIMINISHING TO
G20KT BY EVENING.
.THU NIGHT-SAT...VFR.
.SUN AND MON...MVFR CEILINGS. -DZ / -RA. SE SFC FLOW 10-15 KT.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
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 TO 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. ADDITIONALLY...LOW-LYING
COASTAL AREAS MAY EXPERIENCE EXACERBATED ROAD FLOODING DURING
TIMES OF HIGH TIDE WEDNESDAY MORNING.
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 THROUGH THIS AFTERNOON FOR CTZ005>012.
WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR CTZ008-011-012.
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR CTZ007-009-010.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST THIS MORNING FOR
CTZ009-010.
NY...FLOOD WATCH THROUGH THIS AFTERNOON FOR NYZ067>075-078>081-
176>179.
WIND ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR NYZ078>081-177-
179.
COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR NYZ079-
081.
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR NYZ071>075-176-
178.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST THIS MORNING FOR
NYZ071-073.
HIGH SURF ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ080-081-
178-179.
NJ...FLOOD WATCH THROUGH THIS AFTERNOON FOR NJZ002-004-006-103>108.
WIND ADVISORY UNTIL 9 AM EST THIS MORNING FOR NJZ006.
MARINE...GALE WARNING UNTIL 6 AM EST THURSDAY FOR ANZ330-335-338-340-
345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/MET
NEAR TERM...GOODMAN/MALOIT/NV
SHORT TERM...GOODMAN
LONG TERM...MET
AVIATION...SEARS
MARINE...GOODMAN/MALOIT/MET
HYDROLOGY...GOODMAN/MET
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
320 PM EST WED NOV 27 2013
...CHILLY TEMPERATURES TONIGHT THROUGH EARLY THURSDAY MORNING...
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A HIGHLY AMPLIFIED UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS...HIGHLIGHTED BY LONGWAVE
RIDGING OVER THE INTER-MOUNTAIN WEST AND A DEEP/SHARP LONGWAVE
TROUGH OVER THE EASTERN HALF OF THE NATION. THE TROUGH AXIS EXTENDS
FROM THE EASTERN GREAT LAKES TO THE SOUTHEAST COAST. THE STRONG
SOUTHERN STREAM IMPULSE WHICH BROUGHT THE SHOWERS AND STORMS TO THE
AREA LAST NIGHT IS NOW QUICKLY PIVOTING AWAY FROM OUR REGION UP THE
EASTERN SEABOARD. WV IMAGERY SHOWS A BROAD EXPANSE OF IMPRESSIVE
SUBSIDENCE/DRYING IN THE MID/UPPER LEVELS BEHIND THIS SHORTWAVE
COVERING THE ENTIRE PENINSULA.
AT THE SURFACE...COLD FRONT HAS PASSED WELL OFF TO THE EAST OF THE
PENINSULA WITH GUSTY NORTHWEST WINDS IN ITS WAKE. DEWPOINTS HAVE
BECOME MUCH MORE COMFORTABLE...DROPPING INTO THE MIDDLE 40S NORTH
AND MIDDLE 50S SOUTH. EXPECT THESE VALUES TO CONTINUE TO DROP
THROUGH THE EVENING HOURS. A LONG CAA FETCH OVER THE RELATIVELY WARM
GULF WATERS IS PRODUCING SCT-BKN STRATOCU WITHING THE NW FLOW.
PERIODS OF THESE SCT-BKN CLOUDS SHOULD CONTINUE TO ROLL ASHORE UNTIL
THE WINDS VEER AROUND MORE TO THE NORTH LATER THIS EVENING.
TEMPERATURES HAVE REACHED THEIR MAXIMUMS FOR THE DAY AND ARE NOW
BEGINNING TO FALL WITH THE CONTINUED CAA AND LESSENING SUN ANGLE.
THIS EVENING WILL BECOME CHILLY QUICKLY WITH THE SETTING OF THE SUN.
&&
.SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
THE COLDEST NIGHT OF THE SEASON SO FAR IN STORE FOR MANY LOCATIONS.
THE FREEZE WATCH HAS BEEN UPGRADED TO A FREEZE WARNING FOR CITRUS
AND LEVY COUNTY FOR LATE TONIGHT AND EARLY THURSDAY MORNING. MUCH OF
LEVY COUNTY IS EXPECTED TO DROP BELOW FREEZING FOR A FEW HOURS AWAY
FROM THE IMMEDIATE COAST WITH MAINLY NORTHERN INLAND AREAS OF CITRUS
COUNTY. THE FREEZE WATCH WAS CANCELLED FOR SUMTER AND HERNANDO
COUNTIES AS TEMPERATURES ARE NO LONGER EXPECTED TO REACH THE
FREEZING POINT FOR 2 OR MORE HOURS. HOWEVER...NORMALLY COLDER AND
SHELTERED LOCATIONS WITHIN SUMTER AND HERNANDO COUNTIES MAY STILL
BRIEFLY TOUCH FREEZING AROUND SUNRISE. EVEN OUTSIDE OF THESE MORE
NORTHERN ZONES...TEMPERATURES WILL BECOME QUITE CHILLY BY SUNRISE
WITH WIDESPREAD MID 30S TO LOWER 40S. TEMPERATURES ALONG THE
IMMEDIATE COAST FROM PINELLAS COUNTY SOUTHWARD SHOULD REMAIN IN THE
40S WITH MORE INFLUENCE FROM THE WATER. THESE LOW TEMPERATURES
REGION-WIDE REPRESENT A 25-30 DEGREE DECREASE FROM THE LOW
TEMPERATURES ON WEDNESDAY MORNING. WINDS WILL DIMINISH FROM THE
GUSTY NATURE THIS AFTERNOON...BUT WITH THE HIGH WELL TO OUR
NORTH...DO NOT ANTICIPATE A DECOUPLING OF THE BOUNDARY LAYER AND
WINDS GOING CALM. THEREFORE AT LEAST SOME MOMENTUM WILL PUSH WIND
CHILLS AROUND SUNRISE DOWN INTO THE LOWER/MID 30S FOR ALL BUT THE
FAR SOUTHERN ZONES. FROM HERNANDO/SUMTER COUNTY NORTHWARD...WIND
CHILLS ARE FORECAST TO BRIEFLY DROP INTO THE 20S. SO EITHER WAY...IT
WILL BE CHILLY MORNING FOR ANYONE WITH OUTDOOR ACTIVITIES WITHIN A
FEW HOURS EITHER SIDE OF SUNRISE.
THANKSGIVING DAY / NIGHT...
A PLEASANT/FAIR DAY IN STORE AFTER THE CHILLY START. A DEEP DRY
ATMOSPHERIC COLUMN WITHIN ZONAL FLOW ALOFT WILL KEEP OUR FORECAST
RAIN FREE WITH A NORTHEAST WIND SOUTH OF A RIDGE AXIS OVER THE
CAROLINAS. THIS NORTHEAST FLOW WILL BRING SOME LOW LEVEL MOISTURE IN
FROM THE ATLANTIC BY THE AFTERNOON. THEREFORE LOOKING FOR MOSTLY
SUNNY SKIES IN THE MORNING AND THEN A MIX OF SUN AND CLOUDS UNDER A
SCT CU FIELD FOR THE AFTERNOON. HIGH TEMPERATURES WILL RECOVER FROM
THE COOL MORNING TO AROUND 60 FOR LEVY COUNTY...RANGING TO THE
MIDDLE/UPPER 60S ALONG THE I-4 CORRIDOR AND AROUND 70 DOWN TOWARD FT
MYERS. THURSDAY NIGHT WILL BE ANOTHER COOL NIGHT...BUT DO NOT
ANTICIPATE ANY FREEZE CONCERNS. LOW TEMPS WILL RANGE FROM THE
MID/UPPER 30S OVER LEVY COUNTY TO THE MID/UPPER 40S FOR MOST OTHER
LOCATIONS. PORTIONS OF SOUTHERN PINELLAS AND COASTAL AREA AROUND
CHARLOTTE COUNTY WILL ALSO BE WARMER.
FRIDAY/FRIDAY NIGHT...
ANOTHER FAIR...PLEASANT...AND DRY DAY ON TAP WITH A WARMING TREND
BEGINNING. HIGH TEMPERATURES RECOVER TO THE LOWER 70S NORTH...TO MID
70S ALONG THE I-4 CORRIDOR...AND UPPER 70S FURTHER SOUTH. LOW
TEMPERATURES FRIDAY NIGHT STAYING IN THE 50S FOR ALL AREAS EXPECT
THE FAR NORTHERN NATURE COAST ZONES.
SAFE TRAVELS FOR THE REST OF THE AFTERNOON AND EARLY EVENING ON THIS
BUSIEST TRAVEL DAY OF THE YEAR. THOSE TRAVELING ON THE I-4 AND
FLORIDA I-75 CORRIDORS THE REMAINDER OF THE DAY CAN EXPECT DRY
CONDITIONS...BUT RATHER GUSTY WINDS OUT OF THE NORTHWEST. WINDS
SHOULD BECOME LESS GUSTY THROUGH THE EVENING HOURS.
&&
.LONG TERM (SATURDAY - NEXT TUESDAY)...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT THROUGH THE LONG TERM
PERIOD. HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE
OVER THE WEEKEND WITH RAIN FREE CONDITIONS EXPECTED. MODEL
SOLUTIONS THEN SHOW A WAVE OF LOW PRESSURE TRACKING ACROSS THE
STATE IN THE SUNDAY NIGHT THROUGH MONDAY NIGHT TIME FRAME. THERE
ARE SOME DIFFERENCES IN STRENGTH AND TIMING OF THIS WAVE OF LOW
PRESSURE...SO WON/T TRY TO PIN DOWN THE EXACT DETAILS AT THIS
TIME...AND WILL CARRY SLIGHT CHANCE/LOW CHANCE POPS. HIGH PRESSURE
THEN BUILDS BACK IN BEHIND THE EXITING WAVE THROUGH THE MIDDLE OF
NEXT WEEK...SO WILL KEEP THE FORECAST FREE FROM RAIN. TEMPERATURES
THROUGH THE LONG TERM PERIODS WILL RUN NEAR TO SLIGHTLY ABOVE
NORMAL.
&&
.AVIATION...
BKN MAINLY VFR CIGS...BUT OCNL MVFR...THROUGH THE AFTERNOON. SCT
THIS EVENING THEN SKC THROUGH THU MORNING. GUSTY W-NW WINDS DIMINISH
IN THE EVENING AND VEER TO NORTHERLY.
&&
.MARINE...
SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH THURSDAY MORNING.
STRONG NORTHWEST WINDS IN THE WAKE OF A COLD FRONT ARE AT HIGH END
ADVISORY CRITERIA. WAVE HEIGHTS HAVE ALSO INCREASE TO BETWEEN 9-11
FEET OFFSHORE. WINDS WILL SHIFT NORTH OVERNIGHT AND THEN NORTHEAST
ON THURSDAY MORNING WITH SOME IMPROVEMENT IN CONDITIONS THROUGH THE
DAY...ALTHOUGH PERIODS OF CAUTIONARY LEVEL WINDS ARE LIKELY TO
LINGER THROUGH THE END OF THE WEEK.
&&
.FIRE WEATHER...
HIGH PRESSURE SETTLES IN OVER THE GULF COAST TONIGHT WITH A COOL TO
COLD DRY NORTHERLY FLOW. THE HIGH CONTINUES THURSDAY AND PROVIDES
ROBUST TRANSPORT WINDS THE RESULT IN SOME HIGH DISPERSION
INDICES...ESPECIALLY INLAND...ALONG WITH AFTERNOON RELATIVE HUMIDITY
VALUES THAT APPROACH BUT DO NOT REACH CRITICAL LEVELS. THE HIGH MOVES
EASTWARD THROUGH THE WEEKEND WITH BOTH TEMPERATURES AND HUMIDITY
MODERATING AS THE LOW LEVEL FLOW BECOMES NORTHEASTERLY. A WEAK WAVE
OF LOWER PRESSURE TRACKS ACROSS FLORIDA MONDAY WITH A SLIGHT CHANCE
TO A CHANCE OF SHOWERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 38 66 51 74 / 0 0 0 10
FMY 44 71 55 79 / 0 0 10 10
GIF 39 68 49 74 / 0 0 10 10
SRQ 42 69 52 76 / 0 0 0 10
BKV 32 65 44 73 / 0 0 0 10
SPG 46 66 56 73 / 0 0 0 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR
CHARLOTTE-CITRUS-DESOTO-HARDEE-HERNANDO-HIGHLANDS-
HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-PINELLAS-POLK-
SARASOTA-SUMTER.
FREEZE WARNING FROM 3 AM TO 9 AM EST THURSDAY FOR CITRUS-
LEVY.
RIP CURRENT RISK THROUGH THURSDAY AFTERNOON FOR CHARLOTTE-
HILLSBOROUGH-LEE-MANATEE-PINELLAS-SARASOTA.
HIGH SURF ADVISORY UNTIL 7 AM EST THURSDAY FOR CHARLOTTE-
HILLSBOROUGH-LEE-MANATEE-PINELLAS-SARASOTA.
GULF WATERS...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR
BONITA BEACH TO ENGLEWOOD OUT 20 NM-ENGLEWOOD TO TARPON
SPRINGS OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER
OUT 20 NM-TARPON SPRINGS TO SUWANNEE RIVER OUT 20 TO
60 NM.
SMALL CRAFT ADVISORY UNTIL 1 PM EST THURSDAY FOR BONITA
BEACH TO ENGLEWOOD OUT 20 TO 60 NM-ENGLEWOOD TO
TARPON SPRINGS OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
TAMPA BAY WATERS.
&&
$$
SYNOPSIS/SHORT TERM/MARINE...MROCZKA
AVIATION/FIRE WEATHER...RUDE
LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1015 AM EST WED NOV 27 2013
.UPDATE (TODAY THROUGH THANKSGIVING DAY)...
15Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A HIGHLY AMPLIFIED UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS...HIGHLIGHTED BY LONGWAVE
RIDGING OVER THE INTER-MOUNTAIN WEST AND A DEEP/SHARP LONGWAVE
TROUGH OVER THE EASTERN HALF OF THE NATION. THE TROUGH AXIS EXTENDS
FROM THE EASTERN GREAT LAKES TO THE SOUTHEAST COAST. THE STRONG
SOUTHERN STREAM IMPULSE WHICH BROUGHT THE SHOWERS AND STORMS TO THE
AREA LAST NIGHT IS NOW PIVOTING OVERHEAD AND WILL QUICKLY BE EXITING
TO OUR NORTHEAST AND UP THE EASTERN SEABOARD DURING THE AFTERNOON
HOURS. WV IMAGERY SHOWS A BROAD EXPANSE OF SUBSIDENCE/DRYING IN THE
MID/UPPER LEVELS BEHIND THIS SHORTWAVE AND QUICKLY SPREADING OVER
OUR HEADS. THIS IS ONE OF THOSE SITUATIONS WHERE THE 12Z KTBW
SOUNDING PROFILE WAS UNREPRESENTATIVE OF OUR ATMOSPHERIC COLUMN
WITHIN A VERY SHORT TIME...AS ITS RELEASE WAS RIGHT BEFORE THE
PASSING OF THE SHORTWAVE AXIS. ALTHOUGH NO DOUBT NOT AN EXACT
REPRESENTATION...THE KTLH SOUNDING PROFILE IS LIKELY A CLOSER
MATCH TO WHAT WE SEE OVERHEAD LATE THIS MORNING IN TERMS OF
MOISTURE.
AT THE SURFACE...COLD FRONT HAS PASSED OFF TO THE EAST OF THE
PENINSULA WITH GUSTY NORTHWEST WINDS IN ITS WAKE. DEWPOINTS HAVE
BECOME MORE COMFORTABLE IN THE PAST SEVERAL HOURS...DROPPING FROM
THE MID 60S DOWN INTO THE 50S. THE LAST RESIDUAL SYNOPTIC LIFT
(EXITING NOW) ALONG WITH A LONG CAA FETCH OVER THE RELATIVELY WARM
GULF WATERS IS PRODUCING SCT-BKN STRATOCU WITHING THE NW FLOW...AND
THE LOW LEVEL LAPSE RATES ALONG WITH THE LAST LARGE SCALE FORCING IS
JUST ENOUGH FOR A FEW RAINDROP/SPRINKLES MOVING ASHORE. DO NOT
EXPECT ANY MEASURABLE PRECIP OUT OF ANY OF THESE SPRINKLES FROM THIS
POINT ON...AND THE BUILDING DRY AIR IN THE LOWER LEVELS ALONG WITH
LOSS OF FORCING SHOULD END ANY LEFTOVER SPRINKLES BY THE AFTERNOON
HOURS. PERIODS OF SCT-BKN CLOUDS MAY HOWEVER CONTINUE TO ROLL ASHORE
UNTIL THE WINDS VEER AROUND MORE TO THE NORTH THIS EVENING.
TEMPERATURES THROUGH EARLY TO MID AFTERNOON WILL NOT CHANGE MORE
THAN A FEW DEGREES AT MOST LOCATIONS AND THEN BEGIN TO FALL DURING
THE LATER AFTERNOON HOURS AS THE SUN ANGLE LESSENS AND CAA
CONTINUES.
THE COLDEST NIGHT OF THE SEASON SO FAR IN STORE FOR MOST LOCATIONS.
A FREEZE WATCH REMAINS IN EFFECT FOR THE LATE NIGHT HOURS FOR
HERNANDO...SUMTER...CITRUS...AND LEVY COUNTIES. THE TEMPERATURES
WILL BE RE-EVALUATED ONE LAST TIME WITH THE 12Z GUIDANCE PACKAGE AND
DECISIONS WILL BE MADE BY MID-AFTERNOON ON WHETHER TO UPGRADE ANY OF
THESE ZONES TO A FREEZE WARNING. EVEN OUTSIDE OF THESE ZONES...
TEMPERATURES WILL BECOME QUITE CHILLY BY SUNRISE WITH WIDESPREAD MID
30S TO LOWER 40S. TEMPERATURES ALONG THE IMMEDIATE COAST FROM
PINELLAS COUNTY SOUTHWARD SHOULD REMAIN IN THE 40S WITH MORE
INFLUENCE FROM THE WATER. WINDS WILL DIMINISH FROM THE GUSTY NATURE
TODAY...BUT WITH THE HIGH WELL TO OUR NORTH...DO NOT ANTICIPATE A
DECOUPLING OF THE BOUNDARY LAYER AND WINDS GOING CALM. THEREFORE AT
LEAST SOME MOMENTUM WILL PUSH WIND CHILLS AROUND SUNRISE DOWN INTO
THE LOWER/MID 30S FOR ALL BUT THE FAR SOUTHERN ZONES. FROM
HERNANDO/SUMTER COUNTY NORTHWARD...WIND CHILLS ARE FORECAST TO
BRIEFLY DROP INTO THE 20S. SO EITHER WAY...IT WILL BE CHILLY MORNING
FOR ANYONE WITH OUTDOOR ACTIVITIES WITHIN A FEW HOURS EITHER SIDE OF
SUNRISE.
THANKSGIVING DAY...
A PLEASANT/FAIR DAY IN STORE AFTER THE CHILLY START. A DEEP DRY
ATMOSPHERIC COLUMN WITHIN ZONAL FLOW ALOFT WILL KEEP OUR FORECAST
RAIN FREE WITH A NORTHEAST WIND SOUTH OF A RIDGE AXIS OVER THE
CAROLINAS. THIS NORTHEAST FLOW WILL BRING SOME LOW LEVEL MOISTURE IN
FROM THE ATLANTIC BY THE AFTERNOON. THEREFORE LOOKING FOR MOSTLY
SUNNY SKIES IN THE MORNING AND THEN A MIX OF SUN AND CLOUDS UNDER A
SCT CU FIELD FOR THE AFTERNOON.
SAFE TRAVELS FOR THE BUSIEST TRAVEL DAY OF THE YEAR. THOSE TRAVELING
ON THE I-4 AND FLORIDA I-75 CORRIDORS THE REMAINDER OF THE DAY CAN
EXPECT DRY CONDITIONS...BUT RATHER GUSTY WINDS (UP TO 25-30 MPH AT
TIMES) OUT OF THE NORTHWEST. ENJOY!
&&
.AVIATION...
BKN MAINLY VFR CIGS...BUT WITH OCNL MVFR CIGS IN VCSH...THROUGH
MID-MORNING. BECOMING SCT DURING THE DAY THEN SKC AROUND SUNSET.
GUSTY W-NW WINDS DIMINISH IN THE EVENING AND BEGIN TO VEER TO
NORTHERLY.
&&
.MARINE...
SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH EARLY THURSDAY
MORNING. WINDS HAVE BECOME NORTHWEST IN THE WAKE OF A COLD FRONT AND
ARE AT HIGH END ADVISORY CRITERIA...WITH SOME NEAR GALE FORCE GUSTS
FOR THE NEXT SEVERAL HOURS. WAVE HEIGHTS HAVE ALSO INCREASE TO
BETWEEN 8-11 FEET. WINDS WILL SHIFT NORTH TONIGHT AND THEN NORTHEAST
ON THURSDAY WITH SOME IMPROVEMENT IN CONDITIONS...ALTHOUGH PERIODS
OF CAUTIONARY LEVEL WINDS ARE LIKELY TO LINGER THROUGH THE END OF
THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 68 41 65 52 / 10 0 0 0
FMY 73 46 70 55 / 10 0 0 10
GIF 70 40 67 52 / 10 0 0 10
SRQ 69 43 68 53 / 10 0 0 0
BKV 65 34 63 44 / 10 0 0 0
SPG 68 47 65 56 / 10 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING
FOR CITRUS-HERNANDO-LEVY-SUMTER.
LAKE WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS
EVENING FOR CHARLOTTE-CITRUS-DESOTO-HARDEE-HERNANDO-
HIGHLANDS-HILLSBOROUGH-LEE-LEVY-MANATEE-PASCO-
PINELLAS-POLK-SARASOTA-SUMTER.
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.
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 THIS EVENING FOR
TAMPA BAY WATERS.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
923 PM CST THU NOV 28 2013
.UPDATE...
ISSUED AT 917 PM CST THU NOV 28 2013
AN UPDATE WAS JUST SENT TO LOWER TEMPERATURES 2 OR 3 DEGREES OVER
THE NORTHERN HALF OF THE FORECAST AREA. AT 03Z OBSERVED TEMPS WERE
WITHIN A FEW DEGREES OF FORECAST MINS AT SEVERAL SITES NORTH OF I80.
LIGHT AND VARIABLE WINDS AND CLEAR SKIES THE REST OF THE NIGHT
WILL ALLOW TEMPS TO CONTINUE COOLING...REACHING THE SINGLE DIGITS
TO AROUND 10 BY SUNRISE.
&&
.SYNOPSIS...
ISSUED AT 218 PM CST THU NOV 28 2013
A WEAK SURFACE LOW MOVED EASTWARD INTO SOUTHERN LAKE MICHIGAN
DURING THE DAY ON THURSDAY WITH A COLD FRONT STRETCHING SOUTHWESTWARD
TO KSTL TO KJLN IN SOUTHWEST MISSOURI. SURFACE HIGH SAT OVER
EASTERN NORTH DAKOTA. STRATUS ALONG THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE HAS SLOWLY DISSIPATED THROUGH THE DAY. TEMPERATURES
WERE IN THE UPPER 20S IN NORTHWEST ILLINOIS TO THE LOWER 40S IN
WEST CENTRAL ILLINOIS.
A CHANGE IN THE 500 HPA PATTERN WILL OCCUR OVER
THE NEXT SEVEN DAYS AS WE GO FROM THE CURRENT NORTHWEST FLOW ALOFT
TO A MORE ZONAL FLOW WHICH WILL CONTINUE INTO EARLY NEXT WEEK.
THIS WILL RESULT IN SLOWLY MODERATING TEMPERATURES AS THE COLD AIR
OF THE LAST WEEK RETREATS NORTHWARD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE NAM/RAP BEING AN
OUTLIER WITH LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION. THE
MAIN FORECAST CONCERNS WILL BE THE POTENTIAL FOR CLOUD COVER
OVERNIGHT INTO FRIDAY AS WELL AS TEMPERATURES ON FRIDAY.
HIGH PRESSURE IS FORECAST TO BUILD SOUTHEASTWARD OVERNIGHT AND BE
CENTERED ALONG THE IOWA AND ILLINOIS BORDER BY 12 UTC ON FRIDAY. AN
EXTENSIVE STRATUS DECK DEVELOPED ON THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE THIS MORNING WITH A STRONG INVERSION IN PLACE
ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS. THE 12 UTC SOUNDINGS
AT KBIS AND KABR SHOWED EXTENSIVE LOW LEVEL MOISTURE IN PLACE. THE
ECMWF...GFS... AND GEM CONTINUE TO SHOW A DRIER INVERSION IN PLACE
ACROSS THE REGION OVERNIGHT WHILE THE NAM AND RAP SHOW MORE
MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE BUT NOT TO THE
EXTENT THAT EXISTED AT KBIS AND KABR THIS MORNING. THEREFORE I AM
NOT ANTICIPATING THE FORMATION OF NEW STRATUS TONIGHT SO GOING
WITH CLEAR SKIES TONIGHT. A GOOD RADIATIONAL COOLING NIGHT AND
EXPECT TEMPERATURES TO FALL QUICKLY THIS EVENING.
HIGH PRESSURE IS FORECAST TO SHIFT EASTWARD DURING THE DAY ON
FRIDAY WITH WINDS VEERING TO THE SOUTHEAST DURING THE AFTERNOON HOURS.
850 HPA TEMPERATURES WARM FROM -4 TO -10*C TODAY TO 0 TO -4*C ON
FRIDAY. HAVE WARMED TEMPERATURES UP BY A COUPLE OF DEGREES BUT MID
LEVEL CLOUDINESS WILL BE ON THE INCREASE TOMORROW AHEAD OF ANOTHER
WAVE THAT WILL ARRIVE ON SATURDAY. THE INCREASING CLOUDS MAY HELP
TO KEEP TEMPERATURES FROM WARMING AS THEY DID TODAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
FRIDAY NIGHT...WEAK NORTHERN STREAM CLIPPER WILL CONTINUE MOVING TO
GREAT LAKES BY SATURDAY MORNING. OVERNIGHT LOW TEMPERATURES WILL BE
IN THE 20S.
SATURDAY AND SUNDAY...TEMPERATURES WILL RANGE NEAR OR SLIGHTLY ABOVE
NORMAL ON SATURDAY BEFORE A WEAK SURFACE TROF CROSSES THE AREA
SWITCHING THE WIND TO THE WEST NORTHWEST LATE IN THE DAY. WITH
LIMITED MOISTURE THIS TROF PASSAGE WILL BE DRY. ON SUNDAY...WEAK
COLD AIR ADVECTION BEHIND THE TROF PASSAGE WILL PRODUCE LOW
TEMPERATURES IN THE IN 20S ON SATURDAY NIGHT WITH HIGHS IN THE MID
30S ACROSS THE NORTHERN THIRD OF THE FORECAST AREA WITH HIGHS IN THE
40S OVER THE SOUTH.
MONDAY THROUGH WEDNESDAY...LATEST MEDIUM RANGE MODEL SOLUTIONS
CONTINUE TO DIVERGE BUT THERE IS OVERALL AGREEMENT IN DEVELOPING A
DEEP TROF ACROSS THE WESTERN UNITED STATES BY MID WEEK. THE ENERGETIC
SYSTEM CURRENTLY DIVING SOUTH ALONG THE WEST COAST WILL BEGIN A
PERIOD OF ACTIVE WEATHER FOR THE MIDWEST. THE 12Z GFS KEEPS THE
FORECAST AREA MAINLY DRY THROUGH TUESDAY. HOWEVER...THE 12Z ECMWF IS
FASTER AND BRINGS PRECIPITATION INTO THE REGION ON MONDAY. IN EITHER
CASE MOISTURE ADVECTION FROM THE GULF OF MEXICO AHEAD OF THE SURFACE
LOW WILL BREAK OUT PRECIPITATION EITHER MONDAY OR TUESDAY. THE
PRECIPITATION COULD FALL AS A MIXTURE OF RAIN AND SNOW.
THURSDAY AND FRIDAY...CONFIDENCE IS LOW AS MODEL SOLUTIONS SHOW
MAJOR DISCREPANCIES. THE 12Z RUN OF THE ECMWF PROGS A SURFACE
LOW TO DEVELOP OVER THE CENTRAL ROCKIES AND TRACK NORTHWEST OF IOWA
ON THURSDAY. IF THIS TRACK IS CORRECT WARM AIR ADVECTION AHEAD OF
THIS LOW WOULD PRODUCE A RAIN OR RAIN/SNOW MIX TURNING TO ALL RAIN
WITH A SNOW STORM OCCURRING OVER WESTERN IOWA AND THE NORTHERN
PLAINS. ON THE OTHER HAND THE 12Z RUN OF THE GFS TRACKS THE SURFACE
LOW FURTHER SOUTHEAST AND PROGS IT TO MOVE ACROSS MISSOURI INTO
NORTHERN ILLINOIS/INDIANA BY FRIDAY. IF THE GFS SOLUTION IS CORRECT
THERMAL PROFILES WOULD SUPPORT AN ALL SNOW EVENT LATE NEXT WEEK.
HOWEVER I MUST STRONGLY REITERATE FORECAST CONFIDENCE IS LOW.&&
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 528 PM CST THU NOV 28 2013
SCATTERED TO BROKEN CLOUDS BASES AROUND 4KFT OVER WI AND EASTERN
MN MAY BRUSH NORTHWEST IL AND NEARBY AREAS OF EAST CENTRAL IOWA
THIS EVENING. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY
AFTERNOON AS WEAK HIGH PRESSURE MOVES THROUGH LATE TONIGHT AND
PULLS EAST OF THE FORECAST AREA FRIDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...DLF
SYNOPSIS...COUSINS
SHORT TERM...COUSINS
LONG TERM...KUHL
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
534 PM CST THU NOV 28 2013
.SYNOPSIS...
ISSUED AT 218 PM CST THU NOV 28 2013
A WEAK SURFACE LOW MOVED EASTWARD INTO SOUTHERN LAKE MICHIGAN
DURING THE DAY ON THURSDAY WITH A COLD FRONT STRETCHING SOUTHWESTWARD
TO KSTL TO KJLN IN SOUTHWEST MISSOURI. SURFACE HIGH SAT OVER
EASTERN NORTH DAKOTA. STRATUS ALONG THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE HAS SLOWLY DISSIPATED THROUGH THE DAY. TEMPERATURES
WERE IN THE UPPER 20S IN NORTHWEST ILLINOIS TO THE LOWER 40S IN
WEST CENTRAL ILLINOIS.
A CHANGE IN THE 500 HPA PATTERN WILL OCCUR OVER
THE NEXT SEVEN DAYS AS WE GO FROM THE CURRENT NORTHWEST FLOW ALOFT
TO A MORE ZONAL FLOW WHICH WILL CONTINUE INTO EARLY NEXT WEEK.
THIS WILL RESULT IN SLOWLY MODERATING TEMPERATURES AS THE COLD AIR
OF THE LAST WEEK RETREATS NORTHWARD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE NAM/RAP BEING AN
OUTLIER WITH LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION. THE
MAIN FORECAST CONCERNS WILL BE THE POTENTIAL FOR CLOUD COVER
OVERNIGHT INTO FRIDAY AS WELL AS TEMPERATURES ON FRIDAY.
HIGH PRESSURE IS FORECAST TO BUILD SOUTHEASTWARD OVERNIGHT AND BE
CENTERED ALONG THE IOWA AND ILLINOIS BORDER BY 12 UTC ON FRIDAY. AN
EXTENSIVE STRATUS DECK DEVELOPED ON THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE THIS MORNING WITH A STRONG INVERSION IN PLACE
ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS. THE 12 UTC SOUNDINGS
AT KBIS AND KABR SHOWED EXTENSIVE LOW LEVEL MOISTURE IN PLACE. THE
ECMWF...GFS... AND GEM CONTINUE TO SHOW A DRIER INVERSION IN PLACE
ACROSS THE REGION OVERNIGHT WHILE THE NAM AND RAP SHOW MORE
MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE BUT NOT TO THE
EXTENT THAT EXISTED AT KBIS AND KABR THIS MORNING. THEREFORE I AM
NOT ANTICIPATING THE FORMATION OF NEW STRATUS TONIGHT SO GOING
WITH CLEAR SKIES TONIGHT. A GOOD RADIATIONAL COOLING NIGHT AND
EXPECT TEMPERATURES TO FALL QUICKLY THIS EVENING.
HIGH PRESSURE IS FORECAST TO SHIFT EASTWARD DURING THE DAY ON
FRIDAY WITH WINDS VEERING TO THE SOUTHEAST DURING THE AFTERNOON HOURS.
850 HPA TEMPERATURES WARM FROM -4 TO -10*C TODAY TO 0 TO -4*C ON
FRIDAY. HAVE WARMED TEMPERATURES UP BY A COUPLE OF DEGREES BUT MID
LEVEL CLOUDINESS WILL BE ON THE INCREASE TOMORROW AHEAD OF ANOTHER
WAVE THAT WILL ARRIVE ON SATURDAY. THE INCREASING CLOUDS MAY HELP
TO KEEP TEMPERATURES FROM WARMING AS THEY DID TODAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
FRIDAY NIGHT...WEAK NORTHERN STREAM CLIPPER WILL CONTINUE MOVING TO
GREAT LAKES BY SATURDAY MORNING. OVERNIGHT LOW TEMPERATURES WILL BE
IN THE 20S.
SATURDAY AND SUNDAY...TEMPERATURES WILL RANGE NEAR OR SLIGHTLY ABOVE
NORMAL ON SATURDAY BEFORE A WEAK SURFACE TROF CROSSES THE AREA
SWITCHING THE WIND TO THE WEST NORTHWEST LATE IN THE DAY. WITH
LIMITED MOISTURE THIS TROF PASSAGE WILL BE DRY. ON SUNDAY...WEAK
COLD AIR ADVECTION BEHIND THE TROF PASSAGE WILL PRODUCE LOW
TEMPERATURES IN THE IN 20S ON SATURDAY NIGHT WITH HIGHS IN THE MID
30S ACROSS THE NORTHERN THIRD OF THE FORECAST AREA WITH HIGHS IN THE
40S OVER THE SOUTH.
MONDAY THROUGH WEDNESDAY...LATEST MEDIUM RANGE MODEL SOLUTIONS
CONTINUE TO DIVERGE BUT THERE IS OVERALL AGREEMENT IN DEVELOPING A
DEEP TROF ACROSS THE WESTERN UNITED STATES BY MID WEEK. THE ENERGETIC
SYSTEM CURRENTLY DIVING SOUTH ALONG THE WEST COAST WILL BEGIN A
PERIOD OF ACTIVE WEATHER FOR THE MIDWEST. THE 12Z GFS KEEPS THE
FORECAST AREA MAINLY DRY THROUGH TUESDAY. HOWEVER...THE 12Z ECMWF IS
FASTER AND BRINGS PRECIPITATION INTO THE REGION ON MONDAY. IN EITHER
CASE MOISTURE ADVECTION FROM THE GULF OF MEXICO AHEAD OF THE SURFACE
LOW WILL BREAK OUT PRECIPITATION EITHER MONDAY OR TUESDAY. THE
PRECIPITATION COULD FALL AS A MIXTURE OF RAIN AND SNOW.
THURSDAY AND FRIDAY...CONFIDENCE IS LOW AS MODEL SOLUTIONS SHOW
MAJOR DISCREPANCIES. THE 12Z RUN OF THE ECMWF PROGS A SURFACE
LOW TO DEVELOP OVER THE CENTRAL ROCKIES AND TRACK NORTHWEST OF IOWA
ON THURSDAY. IF THIS TRACK IS CORRECT WARM AIR ADVECTION AHEAD OF
THIS LOW WOULD PRODUCE A RAIN OR RAIN/SNOW MIX TURNING TO ALL RAIN
WITH A SNOW STORM OCCURRING OVER WESTERN IOWA AND THE NORTHERN
PLAINS. ON THE OTHER HAND THE 12Z RUN OF THE GFS TRACKS THE SURFACE
LOW FURTHER SOUTHEAST AND PROGS IT TO MOVE ACROSS MISSOURI INTO
NORTHERN ILLINOIS/INDIANA BY FRIDAY. IF THE GFS SOLUTION IS CORRECT
THERMAL PROFILES WOULD SUPPORT AN ALL SNOW EVENT LATE NEXT WEEK.
HOWEVER I MUST STRONGLY REITERATE FORECAST CONFIDENCE IS LOW.&&
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 528 PM CST THU NOV 28 2013
SCATTERED TO BROKEN CLOUDS BASES AROUND 4KFT OVER WI AND EASTERN
MN MAY BRUSH NORTHWEST IL AND NEARBY AREAS OF EAST CENTRAL IOWA
THIS EVENING. OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH FRIDAY
AFTERNOON AS WEAK HIGH PRESSURE MOVES THROUGH LATE TONIGHT AND
PULLS EAST OF THE FORECAST AREA FRIDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...COUSINS
SHORT TERM...COUSINS
LONG TERM...KUHL
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS JACKSON KY
137 AM EST WED NOV 27 2013
.UPDATE...
ISSUED AT 1035 PM EST TUE NOV 26 2013
IT LOOKS LIKE THE BULK OF THIS FIRST ROUND OF SNOW WILL WIND DOWN
AFTER 06Z BEFORE UPSLOPE KICKS IN AND RENEWS THE MOISTURE AND SNOW
SHOWERS WEDNESDAY MORNING. THE MODELS CONTINUE TO PLAY CATCH-UP WITH
REALITY AS THE LATEST NAM12 AT 00Z IS STILL INSISTING ON A DECENT 1
TO 2 INCH BAND OF SNOW OVER MUCH OF THE AREA BETWEEN NOW AND
MIDNIGHT. OTHER THAN THAT...THE REST OF THE EVENT WILL LIKELY BE MORE
ELEVATIONALLY AND UPSLOPE DRIVEN. ACCORDINGLY HAVE LOWERED AMOUNTS
FOR ALL BUT THE HIGHER ELEVATIONS IN THE EAST WITH THIS UPDATE. WILL
HOLD ON TO THE CURRENT ARRANGEMENT OF ADVISORIES AND WARNINGS...
THOUGH. REPORTS OF A PILE UP ON INTERSTATE 75 IN WHITLEY COUNTY
POINTS OUT THAT IT DOESN/T TAKE MUCH SNOW OR SLEET TO BE VERY
DANGEROUS. HOWEVER...WILL UPDATE THE WSW AND ZONES TO REFLECT A
GREATER SPREAD IN THE AMOUNTS BASED ON TERRAIN...LIMITING THE VALLEY
AMOUNTS. LOOK FOR THESE UPDATES OVER THE NEXT 15 MINUTES OR SO.
UPDATED GRIDS AND SNOW TOTAL GRAPHICS HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
UPDATE ISSUED AT 650 PM EST TUE NOV 26 2013
23Z SFC ANALYSIS SHOWS A DEEPENING LOW PRESSURE CENTER OVER SOUTHEAST
GEORGIA. THIS SYSTEM IS NOW WRAPPING THE COLD AIR INTO EAST KENTUCKY
AND AS A RESULT THE WESTERN PARTS OF ITS COMMA HEAD OF PCPN IS
TRANSITIONING TO SNOW...HEAVY AT TIMES. ON WV SATELLITE...THE
SOUTHERN SHORT WAVE SHOWS UP WELL AS IT PUNCHES INTO THE REGION. THIS
WILL QUICKLY RENEW THE PCPN RETURNS THROUGH THIS PART OF KENTUCKY AND
THE EASTERN TENNESSEE VALLEY AS THE FIRST WAVE MOVES OUT. PER THE
LATEST HRRR AND 18Z NAM12 HAVE INCORPORATED THIS INTO THE FORECAST
AND FINE TUNED SNOW AMOUNTS AND TIMING OF THIS WINTER EVENT THROUGH
THE NIGHT...GENERALLY A BIT MORE SNOW TO THE NORTHEAST AND A ONE TO
TWO HOUR FASTER CHANGEOVER HEADING EAST. THE LATEST TWEETS AND OBS
INDICATE THAT THE SNOW LINE IS MOVING DEEPER INTO OUR NORTHWESTERN
COUNTIES WITH ENHANCEMENTS ON RADAR SUGGESTING A QUICK INCH POSSIBLE
AS THIS BAND MOVES EAST. THE UPDATED FORECAST HAS BEEN SENT TO THE
NDFD AND WEB SERVERS. A ZFP UPDATE WILL FOLLOW SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 256 PM EST TUE NOV 26 2013
THE MODELS CONTINUE TO BE IN PRETTY GOOD AGREEMENT WITH THE
PROGRESSION OF THE SYSTEM. SOME HEAVY RAIN HAS PROMPTED AN AREAL FLOOD
ADVISORY FOR WHITLEY KNOX AND BELL COUNTIES. THE RAIN SHOULD BEGIN TO
TAPER OFF A LITTLE IN THE NEXT FEW HOURS. PUT A SLIDE ON THE INTERNET
TO SHOW THE PROGRESSION OF THE CHANGEOVER THIS EVENING FROM RAIN TO
SNOW. FOR THE SNOW AMOUNTS...THE NEW MODEL RUNS HAD LITTLE CHANGE.
THE DIFFERENCES IN THE NEW SNOW AMOUNT FORECAST WERE NOT VERY
SIGNIFICANT. FEEL LIKE THE FORECAST HAS CAPTURED THE UPPER END OF THE
SNOW FORECAST. ONE CONCERN IS THE COMBINATION OF THE SNOW AND THE
WIND FOR TOMORROW AND TOMORROW EVENING. THIS HAS THE POTENTIAL FOR
CREATING NEAR BLIZZARD CONDITIONS WITH LOW VISIBILITY DUE TO THE
BLOWING SNOW. IT WILL ALSO CAUSE THE WIND CHILLS TO DIP DOWN PRETTY
LOW. ANYONE TRAVELING ON WEDNESDAY NEED TO HAVE BLANKETS AND WARM
COATS IN THE CAR. WITH THE NORTHERLY WINDS BEHIND THE SYSTEM...
UPSLOPE WILL BE A FACTOR AT UPPER ELEVATIONS ALONG THE VIRGINIA AND
TENNESSEE BORDERS. THE UPPER ELEVATIONS ABOVE 2000 FEET HAVE A POTENTIAL
TO SEE SOME PRETTY SUBSTANTIAL SNOW AMOUNTS. WILL UPDATE THE CHANGE
OVER FORECAST SLIDE ON THE INTERNET WITH THE FORECAST CHANGEOVER
TIMES IF THE FORECAST CHANGES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 256 PM EST TUE NOV 26 2013
UPPER LEVEL TROUGH WILL LINGER THROUGH THANKSGIVING DAY WITH A TREND
TOWARDS ZONAL FLOW AS WE HEAD INTO THE WEEKEND. THIS WILL YIELD A
COLD THANKSGIVING DAY...WITH A SLOW WARMING TREND INTO THE WEEKEND.
HIGH PRESSURE WILL SKIRT ACROSS THE AREA FROM THURSDAY THROUGH
SATURDAY...PROVIDING A QUIET STRETCH OF WEATHER FOR A GOOD CHUNK OF
THE HOLIDAY WEEKEND. A FAST MOVING SHORTWAVE WILL PUSH EAST ACROSS
THE AREA LATE IN THE WEEKEND...PRODUCING A SMALL CHANCE FOR RAIN. A
STRONGER SOUTHERN STREAM WAVE WILL PUSH SOUTH OF THE AREA MONDAY INTO
MONDAY NIGHT...PRODUCING A BETTER CHANCE FOR SOME RAIN.
OVERALL...MODELS ARE IN PRETTY DECENT AGREEMENT...SO CONFIDENCE IS
DECENT WELL INTO THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 137 AM EST WED NOV 27 2013
INITIAL CONDITIONS WERE A MIX OF IFR AND LOW END MVFR OVER MOST OF
THE AREA. LIGHT SNOW WAS ALSO FALLING IN MOST PLACES. THE LIGHT SNOW
WILL EASE UP FROM WEST TO EAST OVERNIGHT AND EARLY WEDNESDAY...BUT
MIXED IFR AND MVFR CEILINGS WILL LINGER UNTIL PAST SUNRISE BEFORE
IMPROVEMENT TO MOSTLY MVFR TAKES PLACE DURING THE MORNING.
REDEVELOPMENT OF SNOW SHOWERS IS FORECAST AROUND MIDDAY. THEY MAY
BRING LOCALIZED SHARP REDUCTIONS IN VISIBILITY DURING THE AFTERNOON.
THE SNOW SHOWERS WILL TAPER OFF FROM WEST TO EAST LATE IN THE
AFTERNOON AND EARLY IN THE EVENING...WITH CEILINGS BREAKING UP AT THE
SAME TIME...LEAVING VFR TO FINISH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR KYZ044-
050>052-058>060-069-080-085-086-104-106>109-111-112-114-116.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ068-
079-083-084.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR KYZ087-088-
110-113-115-117>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...KAS
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1249 PM EST WED NOV 27 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 AM EST WED NOV 27 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TODAY MAINLY WEST OF U.S.
131. ADDITIONAL ACCUMULATIONS OF ONE TO FOUR INCHES CAN BE EXPECTED
BEFORE THE PRECIPITATION DWINDLES THIS EVENING. MEANWHILE AREAS
EAST OF U.S. 131 WILL SEE LITTLE TO NO ACCUMULATION.
AFTER A QUIET PERIOD TONIGHT...ANOTHER CLIPPER SYSTEM WILL BRING
ANOTHER ROUND OF SNOW TO ALL OF SOUTHWEST MICHIGAN STARTING TOWARD
DAYBREAK THANKSGIVING DAY. THE SNOW WILL BE ENHANCED BY LAKE
MICHIGAN AND PORTIONS OF WEST CENTRAL LOWER MICHIGAN SHOULD SEE
THREE TO FIVE INCHES OF SNOW. MEANWHILE AREAS SOUTH AND EAST OF
GRAND RAPIDS SHOULD GENERALLY SEE AN INCH OR TWO.
THE ACTIVE WEATHER LOOKS TO FINALLY CALM DOWN BY FRIDAY AND INTO
EARLY NEXT WEEK. TEMPERATURES WILL ALSO BECOME A BIT MILDER WITH
DAYTIME HIGHS MAINLY 35 TO 40 FROM FRIDAY INTO EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1120 AM EST WED NOV 27 2013 WORKING ON DROPPING ALLEGAN
FROM LAKE EFFECT ADVISORY FOR THE AFTERNOON. HRRR AND 12Z NSSL WRF
SUPPORT SHOW MAIN SNOW BAND WILL STAY OFFSHORE OF ALLEGAN COUNTY
THROUGH THE AFTERNOON BEFORE POTENTIALLY MOVING BACK ONSHORE
BEFORE BREAKING UP THIS EVENING. LOOKS LIKE BAND WILL MAINLY
AFFECT THE SOUTHERN HALF OF VAN BUREN THROUGH THE AFTERNOON WITH
LOCAL SNOWFALL EXCEEDING AN INCH PER HOUR. THAT SHOULD RESULT IN A
SWATH OF LOCALLY 5 TO 9 INCH EVENT TOTALS FROM SOUTH HAVEN
SOUTHWARD TOWARDS BENTON HARBOR. ADVISORY FOR MASON/OCEANA
COUNTIES LOOK GOOD WITH ADDITIONAL LOCAL ACCUMULATIONS OF 1 TO 3
INCHES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED NOV 27 2013
ACTIVE SHORT TERM WILL CONTINUE FOR ANOTHER 48 HOURS...THEN WE
FINALLY SEE A PATTERN CHANGE.
WILL KEEP HEADLINES AS IS FOR NOW. HOWEVER IT APPEARS THIS EVENT
MAY UNDER PERFORM SOMEWHAT FROM WHAT WAS EARLIER FORECASTED. IN
LARGE PART THIS SEEMS TO BE DUE TO MOISTURE DEPTH AS INVERSION
HEIGHTS WHERE ONLY 6-7K FT. ANOTHER FACTOR THAT SHOULD COME INTO
PLAY TOWARD MID DAY WILL BE 35 KNOTS WINDS NEAR THE CLOUD TOPS
SHOULD MAY INTRODUCE AN ELEMENT OF SHEAR...NOT ALLOWING THE BANDS TO
BECOME TOO ORGANIZED. DESPITE THIS...IT WILL STILL BE SNOWING WEST
OF U.S. 131 WITH A 335-340 FLOW DOMINATING THROUGH THE DAY. THIS
WILL GIVE THE COASTAL AREAS THE HIGHEST SNOW POTENTIAL WHERE TWO TO
FOUR INCHES OF ADDITIONAL ACCUMS IS LIKELY TODAY. HOWEVER THERE
SHOULD BE A DIMINISHING TREND THROUGH THE AFTERNOON WITH THE
INCREASED SHEAR AND WITH THE FLOW APPEARING TO GO ANTICYCLONIC
QUICKER. WE MAY BE ABLE TO CANCEL THE ADVISORY EARLY...PERHAPS BY
MID AFTERNOON.
THE NEXT SYSTEM WILL BE RIGHT ON OUR HEELS BY DAYBREAK THURSDAY.
THIS WILL BE ANOTHER CLIPPER...WITH THE SHORT WAVE SEEN OF WATER
VAPOR THIS MORNING NW OF LAKE WINNIPEG. THIS SYSTEM CONTINUES TO
LOOK MORE INTERESTING AS IT SHOULD HAVE A SW FLOW LAKE ENHANCEMENT
ELEMENT TO IT. MOISTURE DEPTH IS PROGGED TO BE EVEN BETTER THEN
THIS MORNING/S EVENT. THE FLOW THEN TURNS WNW THURSDAY EVENING...
WITH DECENT MOISTURE DEPTH LINGERING. HAVE DUMPED UP POPS AND
ACCUMS WITH THIS SYSTEM...ESPECIALLY FOR AREAS FROM GRR NORTH AND
WEST. WE MAY NEED ANOTHER ADVISORY TO COVER THIS EVENT...
CONSIDERING THE IMPACT TO HOLIDAY TRAVELERS.
THE PROGRESSIVE PATTERN SHOULD LEAD TO ANOTHER PERIOD OF
ANTICYCLONIC FLOW TOWARD DAYBREAK FRIDAY...SO ANY LAKE EFFECT SHOULD
DIMINISH LATE THURSDAY NIGHT. SURFACE HIGH PRESSURE BUILDS IN BY
FRIDAY ALONG WITH MORE OF A ZONAL FLOW. LOOKS LIKE QUIET WEATHER
FOR BLACK FRIDAY WITH SOME SUN COMING THROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED NOV 27 2013
THE LONG TERM PERIOD LOOKS RATHER UNEVENTFUL AS THE POLAR JET AND
COLD AIR RETREATS FOR AWHILE. TEMPERATURES WILL UNDERGO A MODERATING
TREND WITH HIGHS RECOVERING TO CLOSER TO NORMAL VALUES FOR THIS TIME
OF YEAR...NEAR 40. NO MAJOR STORMS ARE EXPECTED AND NO BIG COOL
DOWNS OR WARM UPS WILL OCCUR. ONLY OCCASIONAL LOW PROBABILITIES FOR
LIGHT SNOW OR MIXED LIGHT RAIN AND SNOW ARE FORECAST.
SEVERAL WEAK SHORTWAVES MOVING THROUGH A RELATIVELY FLAT/ZONAL ALOFT
WILL BRING THE OCCASIONAL LOW CHANCES OF LIGHT PRECIPITATION. ONE
WAVE AND ASSOCIATED SFC TROUGH/COLD FRONT ARRIVES SATURDAY NIGHT
THEN EXITS EARLY SUNDAY. AFTER THAT THE TIMING OF THESE WEAK
FEATURES BECOMES QUITE SKETCHY AND RESULTS IN LOW /20-30 PCT/ POPS
IN SEVERAL CONSECUTIVE FCST PERIODS.
IT IS VERY POSSIBLE THAT WE WILL BE ABLE TO REMOVE CHANCES OF PRECIP
ENTIRELY FOR SUNDAY NIGHT THROUGH TUESDAY IN LATER FORECASTS. MODELS
ARE HINTING AT A SFC HIGH BECOMING ESTABLISHED TO OUR NORTH OVER
ONTARIO WITH A RIDGE EXTENDING SOUTH ACROSS THE GRTLKS REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1248 PM EST WED NOV 27 2013
MAIN ISSUES FOR THE 18Z FCSTS WILL BE LAKE EFFECT TRENDS AND THEN
SNOW TRENDS FOR THU AS THE NEXT WAVE OF LOW PRESSURE MOVES THROUGH.
BAND OF LAKE EFFECT HAS MOVED WEST OF ALL THE TERMINALS AND OVER
THE ERN PORTION OF LAKE MICHIGAN WITH A FLOW FROM NORTH. SOME
DIURNAL CLOUD COVER HAS FORMED OVER INLAND AREAS...MORE CONCENTRATED
EAST OF U.S.-131. THIS WAVE A MIX OF VFR AND MVFR...WHICH HAS NOW
LIFTED TO MAINLY ALL VFR NOW. WE EXPECT THIS WILL NOT BE AN ISSUE.
FLOW WILL TRANSITION TO MORE FROM THE NW THIS EVENING...AND
EVENTUALLY FROM THE SW OVERNIGHT TONIGHT. THIS WILL SHIFT THE LAKE
SNOW BAND INLAND. THIS WILL BRING A BRIEF YET MODERATE BURST OF
SNOW TO THE AREA FROM WEST TO EAST LATE TONIGHT AND INTO THU
MORNING WITH THE HIGHER IMPACT AT WRN TERMINALS. SOME IFR WILL BE
POSSIBLE IN THIS BURST ESPECIALLY WEST BEFORE IT BREAKS UP.
SNOW WILL DEVELOP THEN AT KMKG AND KGRR AND AREAS NORTH THU
MORNING AS A WAVE OF LOW PRESSURE MOVES THROUGH. LAKE MICHIGAN
WILL HELP TO ENHANCE THIS SNOW. THIS SHOULD BRING SOLID IFR
CONDITIONS AND LOWER TO KMKG AND AREAS NORTH INTO EARLY THU
AFTERNOON. CONDITIONS SHOULD START TO IMPROVE AFTER 18Z THU AS THE
SNOW BEGINS TO MOVE OUT.
&&
.MARINE...
ISSUED AT 326 AM EST WED NOV 27 2013
SCA WILL BE MAINTAINED THROUGH TONIGHT. WE MAY NEED TO EXTEND IT
INTO THURSDAY...BUT CONDITIONS BY THEN LOOK FAIRLY MARGINAL AND
WILL EVALUATE WITH FURTHER FORECAST PACKAGES. THURSDAY NIGHT AND
FRIDAY LOOKS CALMER WITH HIGH PRESSURE BUILDING IN.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST WED NOV 27 2013
ALL PCPN IN THE SHORT TERM SHOULD BE SNOW AND NO HYDRO IMPACTS ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST THURSDAY FOR MIZ037-043-
071.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...COBB
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...NJJ
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1118 AM EST WED NOV 27 2013
LATEST UPDATE...
.SYNOPSIS...
ISSUED AT 326 AM EST WED NOV 27 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE TODAY MAINLY WEST OF U.S.
131. ADDITIONAL ACCUMULATIONS OF ONE TO FOUR INCHES CAN BE EXPECTED
BEFORE THE PRECIPITATION DWINDLES THIS EVENING. MEANWHILE AREAS
EAST OF U.S. 131 WILL SEE LITTLE TO NO ACCUMULATION.
AFTER A QUIET PERIOD TONIGHT...ANOTHER CLIPPER SYSTEM WILL BRING
ANOTHER ROUND OF SNOW TO ALL OF SOUTHWEST MICHIGAN STARTING TOWARD
DAYBREAK THANKSGIVING DAY. THE SNOW WILL BE ENHANCED BY LAKE
MICHIGAN AND PORTIONS OF WEST CENTRAL LOWER MICHIGAN SHOULD SEE
THREE TO FIVE INCHES OF SNOW. MEANWHILE AREAS SOUTH AND EAST OF
GRAND RAPIDS SHOULD GENERALLY SEE AN INCH OR TWO.
THE ACTIVE WEATHER LOOKS TO FINALLY CALM DOWN BY FRIDAY AND INTO
EARLY NEXT WEEK. TEMPERATURES WILL ALSO BECOME A BIT MILDER WITH
DAYTIME HIGHS MAINLY 35 TO 40 FROM FRIDAY INTO EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1120 AM EST WED NOV 27 2013 WORKING ON DROPPING ALLEGAN
FROM LAKE EFFECT ADVISORY FOR THE AFTERNOON. HRRR AND 12Z NSSL WRF
SUPPORT SHOW MAIN SNOW BAND WILL STAY OFFSHORE OF ALLEGAN COUNTY
THROUGH THE AFTERNOON BEFORE POTENTIALLY MOVING BACK ONSHORE
BEFORE BREAKING UP THIS EVENING. LOOKS LIKE BAND WILL MAINLY
AFFECT THE SOUTHERN HALF OF VAN BUREN THROGH THE AFTERNOON WITH
LOCAL SNOWFALL EXCEEDING AN INCH PER HOUR. THAT SHOULD RESULT IN A
SWATH OF LOCALLY 5 TO 9 INCHE EVENT TOTALS FROM SOUTH HAVEN
SOUTHWARD TOWARDS BENTON HARBOR. ADVISORY FOR MASON/OCEANA
COUNTIES LOOK GOOD WITH ADDITIONAL LOCAL ACCUMULATIONS OF 1 TO 3
INCHES.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 326 AM EST WED NOV 27 2013
ACTIVE SHORT TERM WILL CONTINUE FOR ANOTHER 48 HOURS...THEN WE
FINALLY SEE A PATTERN CHANGE.
WILL KEEP HEADLINES AS IS FOR NOW. HOWEVER IT APPEARS THIS EVENT
MAY UNDER PERFORM SOMEWHAT FROM WHAT WAS EARLIER FORECASTED. IN
LARGE PART THIS SEEMS TO BE DUE TO MOISTURE DEPTH AS INVERSION
HEIGHTS WHERE ONLY 6-7K FT. ANOTHER FACTOR THAT SHOULD COME INTO
PLAY TOWARD MID DAY WILL BE 35 KNOTS WINDS NEAR THE CLOUD TOPS
SHOULD MAY INTRODUCE AN ELEMENT OF SHEAR...NOT ALLOWING THE BANDS TO
BECOME TOO ORGANIZED. DESPITE THIS...IT WILL STILL BE SNOWING WEST
OF U.S. 131 WITH A 335-340 FLOW DOMINATING THROUGH THE DAY. THIS
WILL GIVE THE COASTAL AREAS THE HIGHEST SNOW POTENTIAL WHERE TWO TO
FOUR INCHES OF ADDITIONAL ACCUMS IS LIKELY TODAY. HOWEVER THERE
SHOULD BE A DIMINISHING TREND THROUGH THE AFTERNOON WITH THE
INCREASED SHEAR AND WITH THE FLOW APPEARING TO GO ANTICYCLONIC
QUICKER. WE MAY BE ABLE TO CANCEL THE ADVISORY EARLY...PERHAPS BY
MID AFTERNOON.
THE NEXT SYSTEM WILL BE RIGHT ON OUR HEELS BY DAYBREAK THURSDAY.
THIS WILL BE ANOTHER CLIPPER...WITH THE SHORT WAVE SEEN OF WATER
VAPOR THIS MORNING NW OF LAKE WINNIPEG. THIS SYSTEM CONTINUES TO
LOOK MORE INTERESTING AS IT SHOULD HAVE A SW FLOW LAKE ENHANCEMENT
ELEMENT TO IT. MOISTURE DEPTH IS PROGGED TO BE EVEN BETTER THEN
THIS MORNING/S EVENT. THE FLOW THEN TURNS WNW THURSDAY EVENING...
WITH DECENT MOISTURE DEPTH LINGERING. HAVE DUMPED UP POPS AND
ACCUMS WITH THIS SYSTEM...ESPECIALLY FOR AREAS FROM GRR NORTH AND
WEST. WE MAY NEED ANOTHER ADVISORY TO COVER THIS EVENT...
CONSIDERING THE IMPACT TO HOLIDAY TRAVELERS.
THE PROGRESSIVE PATTERN SHOULD LEAD TO ANOTHER PERIOD OF
ANTICYCLONIC FLOW TOWARD DAYBREAK FRIDAY...SO ANY LAKE EFFECT SHOULD
DIMINISH LATE THURSDAY NIGHT. SURFACE HIGH PRESSURE BUILDS IN BY
FRIDAY ALONG WITH MORE OF A ZONAL FLOW. LOOKS LIKE QUIET WEATHER
FOR BLACK FRIDAY WITH SOME SUN COMING THROUGH.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 AM EST WED NOV 27 2013
THE LONG TERM PERIOD LOOKS RATHER UNEVENTFUL AS THE POLAR JET AND
COLD AIR RETREATS FOR AWHILE. TEMPERATURES WILL UNDERGO A MODERATING
TREND WITH HIGHS RECOVERING TO CLOSER TO NORMAL VALUES FOR THIS TIME
OF YEAR...NEAR 40. NO MAJOR STORMS ARE EXPECTED AND NO BIG COOL
DOWNS OR WARM UPS WILL OCCUR. ONLY OCCASIONAL LOW PROBABILITIES FOR
LIGHT SNOW OR MIXED LIGHT RAIN AND SNOW ARE FORECAST.
SEVERAL WEAK SHORTWAVES MOVING THROUGH A RELATIVELY FLAT/ZONAL ALOFT
WILL BRING THE OCCASIONAL LOW CHANCES OF LIGHT PRECIPITATION. ONE
WAVE AND ASSOCIATED SFC TROUGH/COLD FRONT ARRIVES SATURDAY NIGHT
THEN EXITS EARLY SUNDAY. AFTER THAT THE TIMING OF THESE WEAK
FEATURES BECOMES QUITE SKETCHY AND RESULTS IN LOW /20-30 PCT/ POPS
IN SEVERAL CONSECUTIVE FCST PERIODS.
IT IS VERY POSSIBLE THAT WE WILL BE ABLE TO REMOVE CHANCES OF PRECIP
ENTIRELY FOR SUNDAY NIGHT THROUGH TUESDAY IN LATER FORECASTS. MODELS
ARE HINTING AT A SFC HIGH BECOMING ESTABLISHED TO OUR NORTH OVER
ONTARIO WITH A RIDGE EXTENDING SOUTH ACROSS THE GRTLKS REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 657 AM EST WED NOV 27 2013
PREDOMINATELY VFR CONDITIONS EXPECTED TODAY AND TONIGHT AT MOST OF
THE TERMINALS AS LAKE EFFECT SNOW BANDS CONTINUE TO HUG THE
COASTLINE. KMKG COULD SEE OCNL MVFR CIGS/VSBYS IN SNOW SHOWERS.
NORTHWEST SFC WINDS WILL INCREASE BY MID MORNING AND BECOME GUSTY
TO 25 KTS. THE WINDS WILL DIMINISH BELOW 10 KTS AFTER 00Z TONIGHT.
WIDESPREAD LIGHT SNOW OR FLURRIES WILL DEVELOP AFTER 09Z MAINLY
WEST OF LAN AND JXN AS WINDS SWING AROUND TO THE SOUTHWEST. WE
COULD SEE SOME IFR VSBYS IN SNOW DEVELOPING AT KMKG BY 12Z.
&&
.MARINE...
ISSUED AT 326 AM EST WED NOV 27 2013
SCA WILL BE MAINTAINED THROUGH TONIGHT. WE MAY NEED TO EXTEND IT
INTO THURSDAY...BUT CONDITIONS BY THEN LOOK FAIRLY MARGINAL AND
WILL EVALUATE WITH FURTHER FORECAST PACKAGES. THURSDAY NIGHT AND
FRIDAY LOOKS CALMER WITH HIGH PRESSURE BUILDING IN.
&&
.HYDROLOGY...
ISSUED AT 326 AM EST WED NOV 27 2013
ALL PCPN IN THE SHORT TERM SHOULD BE SNOW AND NO HYDRO IMPACTS ARE
EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...LAKE EFFECT SNOW ADVISORY UNTIL 1 AM EST THURSDAY FOR MIZ037-043-
064-071.
LM...SMALL CRAFT ADVISORY UNTIL 7 AM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...COBB
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EST WED NOV 27 2013
.UPDATE...
ISSUED AT 1034 PM EST TUE NOV 26 2013
MAIN FCST CONCERNS OVERNIGHT ARE HEADLINES AND LES TRENDS. WITH KDLH
RADAR SHOWING LES BANDS STREAMING INTO FAR WRN UPPER MI TOWARD THE
KIWD AREA...SNOW LIKELY HAS HAS BEEN FAIRLY HVY IN THAT AREA THIS
EVENING. BANDS HAVE BEEN MOVING THOUGH...PREVENTING MORE SUBSTANTIAL
ACCUMULATION. OVER ERN LAKE SUPERIOR...LES HAS BECOME MORE
WIDESPREAD WITH A GENERAL UPTICK IN INTENSITY UNDER STRONGER
LOW-LEVEL CONVERGENCE ALONG SOUTHWARD MOVING SFC TROF. HOWEVER...
WITH SHORTWAVE TROF NOW SLIPPING E OF LAKE SUPERIOR PER WATER VAPOR
IMAGERY...HAVE CONCERN THAT SNOW ACCUMULATIONS NEED TO BE TONED DOWN
ACROSS THE BOARD OVERNIGHT/WED MORNING AS MODEL GUIDANCE SHOWS
RATHER HEALTHY LARGE SCALE QVECTOR DIVERGENCE DOMINATING THRU WED
MORNING BEHIND WAVE. SO...APART FROM LOCALIZED LOW-LEVEL
CONVERGENCE/UPSLOPE TERRAIN ENHANCEMENT...LES MAY MOSTLY BE ON THE
LIGHTER SIDE. ON THE PLUS SIDES...DGZ SHOULD BE FAIRLY WELL CENTERED
WITHIN THE UPWARD MOTION ZONE TO FLUFF UP SNOW ACCUMULATIONS...AND
UPSTREAM 00Z CWPL SOUNDING SHOWED A DEEP MOISTURE PROFILE THRU ABOUT
11KFT OR SO. HOWEVER...GIVEN THE LARGE SCALE NEGATIVES...GENERALLY
LOWERED SNOW ACCUMULATIONS FROM THIS POINT FORWARD. THE WARNING FOR
MARQUETTE COUNTY MAY BE TOUGH TO ACHIEVE. IF ANY PLACE DOES REACH
WARNING CRITERIA...IT WILL PROBABLY BE THE HIGHER TERRAIN N AND NW
OF NEGAUNEE WHERE UPSLOPE IS MAXIMIZED. ADVY IS PRETTY MARGINAL FOR
THE KEWEENAW OVERNIGHT WITH WINDS BECOMING A LESS FAVORABLE
NORTHERLY DIRECTION. STILL MAY SEE A FEW HEAVIER SNOW BANDS TRAVERSE
THE KEWEENAW...AND GUSTY WINDS...MAINLY ALONG THE LAKE...WILL LEAD
TO BLSN. OVER THE FAR W...PRECONDITIONING FROM LAKE NIPIGON MAY
STILL FAVOR MORE PERSISTENT HEAVIER SNOW...MAINLY FROM THE PORCUPINE
MTNS TO KIWD VCNTY AS THE NIGHT WEARS ON.
&&
.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...(THURSDAY THROUGH TUESDAY)
ISSUED AT 517 AM EST WED NOV 27 2013
THURSDAY...MODELS WERE IN GOOD AGREEMENT...SHOWING A CLIPPER
SHORTWAVE TROUGH WITH MODERATE TO STRONG 700-300 MB QVECTOR CONV
SLIDING THROUGH THE NRN GREAT LAKES. THIS WILL SUPPORT A CHANCE OF
LIGHT SNOW ACROSS THE CWA BUT WITH SNOWFALL AMOUNTS OF A HALF INCH
OR LESS. WITH A WEAK WIND FIELD ACROSS THE AREA AS THE SFC LOW MOVES
THROUGH THE CWA...THE HIGH RES MODELS HAVE BEEN CONSISTENT IN
DEPICTING A MESO-LOW OVER WRN LAKE SUPERIOR WITH A TROUGH AND
ASSOCIATED AREA OF STRONG LOW LEVEL CONV THROUGH THE NRN KEWEENAW
PENINSULA. CONFIDENCE IS MODERATE TO HIGH THAT SOME TYPE OF ENHANCED
MESO-SCALE SNOWBAND WILL DEVELOP BUT IS MUCH LOWER ON WHERE IT WILL
BE LOCATED. WITH DEEP MOISTURE...850 MB TEMPS TO AROUND
-15C...INVERSION HEIGHTS TO 10K FT AND FAVORABLE POSITION OF THE
DGZ...SNOWFALL RATES OF SEVERAL INCHES PER HOUR WOULD BE POSSIBLE
WITH THIS FEATURE. SINCE CONSIDERABLE UNCERTAINTY REMAINS WITH THE
POSITION ANY NARROW SNOWBAND...MORE GENERAL 2 TO 5 INCH SNOW AMOUNTS
ACROSS KEWEENAW COUNTY WERE INCLUDED IN THE FCST. THERE MAY BE THE
POTENTIAL FOR AMOUNTS OF A NARROW BAND OF 8 INCHES OR MORE. DUE TO
ONGOING HEADLINES...AND THE UNCERTAINTY MENTIONED ABOVE...NO
ADDITIONAL HEADLINES WERE ADDED AT THIS TIME BUT THE SNOW POTENTIAL
WILL BE HIGHLIGHTED IN THE HWO.
THURSDAY NIGHT...AS THE SFC LOW AND TROUGH SWING THROUGH THE WRN CWA
IN THE WAKE OF THE SHRTWV...A BRIEF PERIOD OF HEAVIER LAKE ENHANCED
SNOW MAY ALSO MOVE THROUGH THE WEST BEFORE THE STRONGER LOW LEVEL
CONV WEAKENS. THE MODELS SHOW GREATER DIFFERENCES IN HANDLING THE
POSITION OF THE LOW AND LOW LEVEL WINDS AS THE GFS/ECMWF SHOW MAINLY
LIGHT OR OFFSHORE WINDS OVER THE NORTH WHILE THE NAM PUSHES NORTH WINDS
INTO N CNTRL UPPER MI AS A MORE PROMINENT LAKE INDUCED LOW DEVELOPS
OVER SE LAKE SUPERIOR. SO...ONLY CHANCE POPS WERE MENTIONED FOR
AREAS AWAY FROM THE KEWEENAW.
FRIDAY...THERE MAY BE SOME LINGERING LES OVER THE NORTH EARLY BEFORE
WINDS BACK TO THE SW. 850 MB WAA WILL THEN STRENGTHEN AS WEAK MID
LEVEL RIDGING MOVES IN AND THE SFC HIGH PRES BUILDS INTO THE ERN
LAKES. HOWEVER...SFC TEMPS WILL ONLY REBOUND INTO THE MID AND UPPER
20S.
SAT...GFS/ECMWF/GEM SUGGEST ANOTHER CLIPSER SHORTWAVE TROUGH WILL
SLIDE THROUGH THE NRN GREAT LAKES BRINGING A CHANCE OF LIGHT SNOW.
HOWEVER...THE STRONGER FORCING AND SNOW POTENTIAL IS EXPECTED TO
REMAIN NORTH OF LAKE SUPERIOR.
SUN-TUE...A RELATIVELY QUIET PERIOD IS EXPECTED WITH WEAK A WEAK SFC
RIDGE AND INCREASING MID LEVEL RIDGING PREVAILING. MAX READINGS WILL
CLIMB INTO THE LOWER TO MID 30S WITH LOWS GENERALLY IN THE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1152 PM EST TUE NOV 26 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE AT KIWD/KCMX/KSAW THRU MUCH
IF NOT ALL OF THIS FCST PERIOD. AS IS TYPICAL FOR LAKE EFFECT...
CONDITIONS WILL VARY CONSIDERABLY FROM VFR TO AS LOW AS IFR OR EVEN
BRIEF LIFR. LOWEST CONDITIONS WILL BE MORE COMMON AT KIWD/KSAW
DUE TO UPSLOPING NORTHERLY WIND. CONDITIONS WILL GENERALLY VARY BTWN
MVFR AND IFR THRU THE MORNING...WITH LIFR POSSIBLE AT TIMES...
ESPECIALLY AT KSAW EARLY ON IN THE FCST PERIOD. AT KCMX...NORTHERLY
WINDS ARE GENERALLY NOT AS FAVORABLE FOR MORE PERSISTENT LOW
CONDITIONS. CONDITIONS SHOULD GENERALLY BE MVFR WITH BRIEF PERIODS
OF IFR OVERNIGHT...BUT PERIODS OF VFR ARE ALSO LIKELY. ARRIVAL OF
DRIER AIR AND MORE ANTICYCLONIC FLOW LATE MORNING THRU THE AFTN WILL
RESULT IN PREVAILING MVFR AT ALL TERMINALS BY AFTN. SOME PERIODS OF
VFR ARE ALSO POSSIBLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 517 AM EST WED NOV 27 2013
GALES ACROSS THE ERN HALF OF LAKE SUPERIOR WILL DIMINISH BY THIS
AFTERNOON AS THE SFC RIDGE FROM NW ONTARIO INTO MN BUILDS TO THE
EAST AND PRES GRADIENT WEAKENS. 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...ARE EXPECTED SATURDAY OVER MAINLY ERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST THIS EVENING FOR MIZ005.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THIS
AFTERNOON FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ004-006.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LSZ265.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...VOSS
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1152 PM EST TUE NOV 26 2013
.UPDATE...
ISSUED AT 1034 PM EST TUE NOV 26 2013
MAIN FCST CONCERNS OVERNIGHT ARE HEADLINES AND LES TRENDS. WITH KDLH
RADAR SHOWING LES BANDS STREAMING INTO FAR WRN UPPER MI TOWARD THE
KIWD AREA...SNOW LIKELY HAS HAS BEEN FAIRLY HVY IN THAT AREA THIS
EVENING. BANDS HAVE BEEN MOVING THOUGH...PREVENTING MORE SUBSTANTIAL
ACCUMULATION. OVER ERN LAKE SUPERIOR...LES HAS BECOME MORE
WIDESPREAD WITH A GENERAL UPTICK IN INTENSITY UNDER STRONGER
LOW-LEVEL CONVERGENCE ALONG SOUTHWARD MOVING SFC TROF. HOWEVER...
WITH SHORTWAVE TROF NOW SLIPPING E OF LAKE SUPERIOR PER WATER VAPOR
IMAGERY...HAVE CONCERN THAT SNOW ACCUMULATIONS NEED TO BE TONED DOWN
ACROSS THE BOARD OVERNIGHT/WED MORNING AS MODEL GUIDANCE SHOWS
RATHER HEALTHY LARGE SCALE QVECTOR DIVERGENCE DOMINATING THRU WED
MORNING BEHIND WAVE. SO...APART FROM LOCALIZED LOW-LEVEL
CONVERGENCE/UPSLOPE TERRAIN ENHANCEMENT...LES MAY MOSTLY BE ON THE
LIGHTER SIDE. ON THE PLUS SIDES...DGZ SHOULD BE FAIRLY WELL CENTERED
WITHIN THE UPWARD MOTION ZONE TO FLUFF UP SNOW ACCUMULATIONS...AND
UPSTREAM 00Z CWPL SOUNDING SHOWED A DEEP MOISTURE PROFILE THRU ABOUT
11KFT OR SO. HOWEVER...GIVEN THE LARGE SCALE NEGATIVES...GENERALLY
LOWERED SNOW ACCUMULATIONS FROM THIS POINT FORWARD. THE WARNING FOR
MARQUETTE COUNTY MAY BE TOUGH TO ACHIEVE. IF ANY PLACE DOES REACH
WARNING CRITERIA...IT WILL PROBABLY BE THE HIGHER TERRAIN N AND NW
OF NEGAUNEE WHERE UPSLOPE IS MAXIMIZED. ADVY IS PRETTY MARGINAL FOR
THE KEWEENAW OVERNIGHT WITH WINDS BECOMING A LESS FAVORABLE
NORTHERLY DIRECTION. STILL MAY SEE A FEW HEAVIER SNOW BANDS TRAVERSE
THE KEWEENAW...AND GUSTY WINDS...MAINLY ALONG THE LAKE...WILL LEAD
TO BLSN. OVER THE FAR W...PRECONDITIONING FROM LAKE NIPIGON MAY
STILL FAVOR MORE PERSISTENT HEAVIER SNOW...MAINLY FROM THE PORCUPINE
MTNS TO KIWD VCNTY AS THE NIGHT WEARS ON.
&&
.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 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1152 PM EST TUE NOV 26 2013
LAKE EFFECT SNOW SHOWERS WILL CONTINUE AT KIWD/KCMX/KSAW THRU MUCH
IF NOT ALL OF THIS FCST PERIOD. AS IS TYPICAL FOR LAKE EFFECT...
CONDITIONS WILL VARY CONSIDERABLY FROM VFR TO AS LOW AS IFR OR EVEN
BRIEF LIFR. LOWEST CONDITIONS WILL BE MORE COMMON AT KIWD/KSAW
DUE TO UPSLOPING NORTHERLY WIND. CONDITIONS WILL GENERALLY VARY BTWN
MVFR AND IFR THRU THE MORNING...WITH LIFR POSSIBLE AT TIMES...
ESPECIALLY AT KSAW EARLY ON IN THE FCST PERIOD. AT KCMX...NORTHERLY
WINDS ARE GENERALLY NOT AS FAVORABLE FOR MORE PERSISTENT LOW
CONDITIONS. CONDITIONS SHOULD GENERALLY BE MVFR WITH BRIEF PERIODS
OF IFR OVERNIGHT...BUT PERIODS OF VFR ARE ALSO LIKELY. ARRIVAL OF
DRIER AIR AND MORE ANTICYCLONIC FLOW LATE MORNING THRU THE AFTN WILL
RESULT IN PREVAILING MVFR AT ALL TERMINALS BY AFTN. SOME PERIODS OF
VFR ARE ALSO POSSIBLE.
&&
.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 SUPERIOR...
GALE WARNING UNTIL 1 PM EST WEDNESDAY FOR LSZ266-267.
GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR LSZ265.
GALE WARNING UNTIL 5 AM EST WEDNESDAY FOR LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...ROLFSON
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
229 PM CST WED NOV 27 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 215 PM CST WED NOV 27 2013
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH GFS 27.12 HEIGHTS
AND WINDS IMMEDIATELY IDENTIFIED A LONG WAVE TROUGH ACROSS THE
EASTERN CONUS...WITH A CYCLONE DOWNSTREAM OF THIS TROUGH AXIS.
NORTHWEST FLOW PREVAILED ACROSS THE CENTRAL CONUS UPSTREAM OF THE
TROUGH AXIS. A WEAK SHORTWAVE ALONG THE ND/MN BORDER WAS EMBEDDED IN
THIS NORTHWEST FLOW. WARM AIR ADVECTION AHEAD IF THIS SHORTWAVE
TOGETHER WITH THE UPPER LEVEL DYNAMICS ASSOCIATED WITH THE 5M/HR
HEIGHT FALLS WERE THE DRIVING FORCE BEHIND AN AREA OF SNOW ACROSS
NORTHERN MINNESOTA.
THIS EVENING THE FORCING WILL WEAKEN...BUT SNOW SHOULD CONTINUE TO
SPREAD SOUTHEASTWARD INTO NORTHERN WISCONSIN. THE NORTHEASTERN
COUNTIES IN THE CWA WILL BE RIGHT ON THE EDGE OF THIS SNOW...BUT
FORECAST SOUNDINGS FOR EAU CLAIRE AND NEW RICHMOND WOULD SUPPORT AT
LEAST A FEW HOURS OF SNOW. THE LOW LEVEL DRY AIR WILL DELAY THE
ONSET UNTIL CLOSER TO 00Z THIS EVENING. SNOW TOTALS WILL BE LESS
THAN AN INCH...AND SHOULD TAPER OFF TO FLURRIES BY THURSDAY MORNING.
THE CHALLENGE FOR THURSDAYS FORECAST WAS THE CLOUD COVER. INCREASED
IT SLIGHTLY BASED OFF THE 0-1RH FROM BOTH THE NAM AND RAP WHICH SEEM
TO HAVE A GOOD HANDLE ON THE STRATUS CURRENTLY ENTERING NORTHERN
NORTH DAKOTA. ALSO LOWERED HIGH TEMPS A COUPLE OF DEGREES BECAUSE OF
THE INCREASED CLOUD COVER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 215 PM CST WED NOV 27 2013
BIG CHGS ARE EXPECTED NEXT WEEK AS A SIGNIFICANT ARCTIC AIR MASS
SURGES SOUTHWARD ACROSS THE WESTERN CONUS...AND EVENTUALLY TAKING
HOLD OF MOST OF THE U.S...WITH THE EXCEPTION IN THE DEEP SE.
CURRENT LONG WAVE PATTERN REMAINS FROM THE NW ACROSS THE UPPER
MIDWEST ALONG WITH A SPLIT FLOW REGIME FOR THE REMAINDER OF THE
CONUS. THE SOUTHERN STREAM HAS BEEN THE MOST ACTIVE IN RECENT
WEEKS...TAKING THE BULK OF THE SIGNIFICANT WX TRACKS SOUTH AND
EAST OF THE UPPER MIDWEST. ALTHOUGH SOME TIMING AND STRENGTH
PARAMETERS REMAIN UNCLEAR IN THE DETERMINISTIC RUNS FROM BOTH THE
EC/GFS...THERE REMAINS ONE THEME...A SIGNIFICANT COLD AIR MASS
WILL INVADE MOST OF THE U.S. STARTING THIS WEEKEND IN THE PACIFIC
NW...AND EVENTUALLY THE ROCKIES/PLAINS/GREAT LAKES BY THE
FOLLOWING WEEKEND.
USUALLY MODELS ARE TOO FAST ON PATTERN CHGS...AND THIS IS EVIDENT
WITH EACH MODEL RUN. ALTHOUGH THE EC HAS BEEN THE STRONGEST ON THE
DEEP TROUGH DEVELOPING ACROSS MOST OF THE WESTERN/CENTRAL PART OF
THE U.S. BY LATE NEXT WEEK...THE ENSEMBLE MEANS /EC & GFS/ HAVE
CONTINUED TO KEEP A MORE PROGRESSIVE WX PATTERN. EVEN THE LATEST
EC 12Z/27 RUN HAS A MORE PRONOUNCED DEEP TROUGH ACROSS THE
NORTHERN ROCKIES BY THE END OF NEXT WEEK COMPARED TO THE 50H
ENSEMBLE MEAN.
BASICALLY WITH THE STRONGER AND DEEPER TROUGH...STORM SYSTEMS WILL
LIKELY BE SLOWER ON THE ONSET OF SFC LOW /BOMBS/ DEVELOPING ACROSS
THE PLAINS. OVER THE PAST 3-5 RUNS OF THE EC...THE SFC LOW AND
ASSOCIATED ARCTIC BOUNDARY KEEPS GETTING PUSHED BACK IN TIME ON
THE EVOLUTION OF A STRONG STORM SYSTEM IN THE PLAINS. THIS WILL
LIKELY KEEP OUR REGION UNEVENTFUL UNTIL LATE IN THE PERIOD...AND
POSSIBLY OUTSIDE OUR 7 DAY FORECAST IF THE TROUGH IN THE WEST
CONTINUES TO DEEPEN. IN ADDITION TO THE SLOWER PACE OF THE STORM
SYSTEM MOVING OUT INTO THE PLAINS...THE LARGE AREA OF ARCTIC HIGH
PRESSURE CIRCULATING FROM THE EASTERN CANADA...AND ACROSS THE
GREAT LAKES /EAST & NE FLOW IN THE BOUNDARY LAYER/...KEEPS OUR
REGION RELATIVELY DRY. THEREFORE...I AM NOT CONFIDENT ON ANY CHC
OF PRECIPITATION NEXT WEEK UNTIL THIS SYSTEM MOVES OUT INTO THE
PLAINS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1115 AM CST WED NOV 27 2013
AREA OF SNOW ACROSS NORTHERN MINNESOTA WILL WEAKEN AS IT MOVES
SOUTHEAST...AND COULD GRAZE KRNH/KEAU WITH REDUCED VSBYS LATER
THIS AFTERNOON. HOWEVER CONFIDENCE IS LOW...SO NARROWED THE TIMING
WINDOW. ONCE THIS MOVES THROUGH WINDS WILL BECOME
NORTHWESTERLY...AND THIS COULD BRING LOW STRATUS BY THURSDAY
MORNING. FOR NOW WENT WITH A SCATTERED DECK...BUT MAY HAVE TO
INCREASE TO BROKEN BASED ON THE UPSTREAM OBS AND FORECAST
SOUNDINGS FROM THE NAM AND RAP.
KMSP...
NO BIG DIFFERENCES FROM GENERALLY AVIATION DISCUSSION. SNOW SHOULD
REMAIN EAST OF THE METRO...WITH THE MAIN CONCERN BEING MVFR CIGS
THURSDAY. FOR NOW JUST WENT WITH SCATTERED DECK...BUT AS ALLUDED
TO ABOVE MAY HAVE TO INCREASE THIS TO BROKEN. IF CIGS DO
DEVELOP...THEY SHOULD REMAIN ABOVE 1700FT.
/OUTLOOK FOR KMSP/
FRI...VFR. WINDS SE AT 5-10KTS.
SAT...VFR. WINDS SW AT 5-10KTS.
SUN...VFR WITH MVFR AND -SN POSSIBLE. WINDS NE AT 5-10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...JLT
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
627 PM EST THU NOV 28 2013
.SYNOPSIS...
A BROAD UPPER TROUGH OVER THE NORTHEAST WILL CONTINUE TO BRING
PARTLY CLOUDY SKIES TO THE NORTH COUNTRY TONIGHT...BEFORE SURFACE HIGH
PRESSURE OVER THE GREAT LAKES BUILDS EASTWARD FRIDAY. DRY
WEATHER IS EXPECTED THROUGH SATURDAY AS THE HIGH DRIFTS OVER THE
REGION...BEFORE A WEAK UPPER DISTURBANCE RENEWS CHANCES FOR LIGHT
SNOW SATURDAY NIGHT INTO SUNDAY. CHILLY TEMPERATURES WILL PERSIST
THROUGH SATURDAY...RUNNING ABOUT 15 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR...BEFORE A WARM-UP BACK TO NEAR NORMAL SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 615 PM EST THURSDAY...CURRENT FORECAST REMAINS IN GOOD SHAPE
WITH SKIES BEGINNING TO CLEAR AREAWIDE. HAVE REMOVED MENTION OF
SNOW SHOWERS IN THE NORTHERN GREENS AS MOISTURE THROUGH THE COLUMN
IS DRYING OUT. THOUGH I DIDN`T MAKE ANY CHANGES TO LOW
TEMPERATURES...I AM WATCHING AN AREA OF CLOUDINESS SPREAD INTO THE
EASTERN GREAT LAKES ASSOCIATED WITH A CLIPPER-TYPE LOW OVER
MICHIGAN. RAP MODEL 925-700 MB RH RESOLVES THIS CLOUDINESS WELL
AND THE NORTHERN FRINGE OF HIGHER RH BRUSHES THE ADIRONDACKS AND
RUTLAND/WINDSOR COUNTIES AFTER MIDNIGHT. THE MAIN EFFECT THESE
CLOUDS MAY HAVE IS ON HOW COLD LOWS GET IN THE ADIRONDACKS.
THERE`S ALSO SOME PRETTY SIGNIFICANT DIFFERENCES IN MOS GUIDANCE
LOWS TONIGHT WITH THE LAV SHOWING LOWS ABOVE ZERO AT SLK WHILE THE
MAV AND MET LOWS ARE ALL BELOW ZERO. I`LL WAIT TO SEE HOW THE NEXT
COUPLE OF HOURS PLAYS OUT BEFORE MAKING ANY ADJUSTMENTS TO LOWS.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 225 PM EDT FOLLOWS...
STILL DEALING WITH A FEW LIGHT SNOW SHOWERS ACROSS NORTHEAST
VERMONT THIS AFTERNOON...BUT THE GENERAL TREND WILL CONTINUE TO BE
TOWARDS DRIER WEATHER AS SURFACE HIGH PRESSURE BUILDS EASTWARD
FROM THE GREAT LAKES TONIGHT. A BROAD UPPER TROUGH STILL PERSISTS
ALOFT THOUGH AND WITH SHORTWAVE ENERGY PASSING TO OUR SOUTH
TONIGHT...THE MID LEVEL FLOW TURNS SOUTHWESTERLY ALLOWING SOME LOW
LEVEL MOISTURE TO RETURN TO THE NORTH COUNTRY TONIGHT.
THUS...WHILE CURRENT CLOUD COVER WILL LIKELY DISSIPATE TOWARDS 00Z
THIS EVENING...CLOUDS WILL FILL BACK IN FROM THE SOUTHWEST
OVERNIGHT. MID AND UPPER LEVELS ARE REALLY DRY SO FEEL DESPITE THE
LOW LEVEL CLOUDS...CONTINUED CAA ACROSS THE REGION WILL DROP TEMPS
INTO THE SINGLE DIGITS ABOVE ZERO FOR THE MAJORITY OF THE
REGION...WITH SOME BELOW ZERO READINGS POSSIBLE IN THE COLDER
HOLLOWS OF THE NORTHERN ADIRONDACKS AND NORTHEAST KINGDOM.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 225 PM EST THURSDAY...FOR FRIDAY...SURFACE HIGH PRESSURE
BUILDS INTO THE REGION WITH THE AFOREMENTIONED UPPER TROUGH
SLOWLY EXITING TO OUR EAST. MORNING CLOUD COVER WILL GENERALLY
DISSIPATE THROUGH THE DAY...BECOMING CLEAR BY FRIDAY NIGHT. IT`LL
REMAIN PRETTY COLD FOR LATE NOVEMBER WITH HIGHS ONLY A FEW
DEGREES WARMER THAN THURSDAY IN THE UPPER TEENS TO MID 20S...AND
LOWS COLDER FRIDAY NIGHT IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO UNDER CLEAR SKIES AND LIGHT WINDS.
SATURDAY...HIGH PRESSURE SHIFTS OFFSHORE WITH SOUTHERLY RETURN
FLOW DEVELOPING WHICH WILL ALLOW TEMPS TO BEGIN TO MODERATE A
BIT. DRY CONDITIONS CONTINUE WITH PARTLY CLOUDY SKIES AND HIGHS
IN THE 20S EXPECTED. NEXT SYSTEM APPROACHES THE REGION LATE
SATURDAY NIGHT AS A WEAK UPPER TROUGH AND ASSOCIATED SHORTWAVE
ENERGY DROPS SOUTHEASTWARD OUT OF CENTRAL MANITOBA AND THROUGH
THE NORTHERN GREAT LAKES. LOOKS LIKE WE`RE IN FOR A CLASSIC HIGH
POP...LOW QPF SNOW EVENT AS THE SYSTEM LACKS ANY REAL DEEP
MOISTURE...AND WILL CARRY SOME MID-LEVEL 40-50% POPS AFTER
MIDNIGHT FOR SOME LIGHT SNOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 222 PM EST THURSDAY...UPPER LEVEL TROUGH MOVES OVER OR JUST
NORTH OF THE NORTH COUNTRY...BRINGING THREAT OF SNOW SHOWERS
THROUGH SUNDAY NIGHT. THIS WILL BE FOLLOWED BY RIDGE OF HIGH
PRESSURE AT THE SFC...THROUGH EARLY TUESDAY. SOUTHERLY STREAM
ENERGY IN BASE OF UPPER LVL TROUGH WILL DEVELOP INTO COASTAL
SYSTEM AT THE SFC. MODELS DIVERGE ON TRACK OF THIS SYSTEM...SO
HAVE KEPT LOW CHC POPS OVER THE REGION TUESDAY AND TUESDAY NIGHT
AS ECMWF KEEPS MOISTURE WRAPPING IN FROM THE ATLANTIC WITH SFC
LOW TRACKING OFF COAST OF CAPE COD. GFS SHOWING MORE RUN TO RUT
MODEL CONSISTENCY IN KEEPING THE LOW FAR OFF INTO THE ATLANTIC
WITH NORTH COUNTRY STAYING DRY. BEST CHCS FOR PRECIP WILL BE SRN
AND ERN VT. COASTAL LOW MOVES FURTHER OUT TO SEA ON
WEDNESDAY...RESULTING IN DRYING TREND BEFORE ANOTHER SYSTEM
APPROACHES FROM THE WEST. TEMPERATURES WILL BE BELOW NORMAL
THROUGHOUT THE PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THROUGH 00Z SATURDAY...VFR CONDITIONS EXPECTED THROUGHOUT THE TAF
PERIOD WITH JUST SOME SCATTERED LOW AND MID CLOUDS. WINDS BECOMING
LIGHT AND VARIABLE THIS EVENING...AND THEN WEST TO NORTHWEST 5 TO
10 KTS DURING FRIDAY.
OUTLOOK 00Z SATURDAY THROUGH TUESDAY...
00Z SATURDAY THROUGH 12Z SUNDAY...MAINLY VFR AS HIGH PRESSURE
MOVES ACROSS REGION.
12Z SUNDAY THROUGH 12Z MONDAY...VFR/MVFR IN SCATTERED SNOW
SHOWERS.
12Z MONDAY ONWARD...MAINLY VFR WITH RIDGE OF HIGH PRESSURE OVER THE
AREA. SLIGHT CHANCE SNOW SHOWERS OVER EASTERN VERMONT TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...LAHIFF/LOCONTO
SHORT TERM...LAHIFF
LONG TERM...KGM
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
615 PM EST THU NOV 28 2013
.SYNOPSIS...
A BROAD UPPER TROUGH OVER THE NORTHEAST WILL CONTINUE TO BRING
PARTLY CLOUDY SKIES TO THE NORTH COUNTRY TONIGHT...BEFORE SURFACE HIGH
PRESSURE OVER THE GREAT LAKES BUILDS EASTWARD FRIDAY. DRY
WEATHER IS EXPECTED THROUGH SATURDAY AS THE HIGH DRIFTS OVER THE
REGION...BEFORE A WEAK UPPER DISTURBANCE RENEWS CHANCES FOR LIGHT
SNOW SATURDAY NIGHT INTO SUNDAY. CHILLY TEMPERATURES WILL PERSIST
THROUGH SATURDAY...RUNNING ABOUT 15 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR...BEFORE A WARM-UP BACK TO NEAR NORMAL SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 615 PM EST THURSDAY...CURRENT FORECAST REMAINS IN GOOD SHAPE
WITH SKIES BEGINNING TO CLEAR AREAWIDE. HAVE REMOVED MENTION OF
SNOW SHOWERS IN THE NORTHERN GREENS AS MOISTURE THROUGH THE COLUMN
IS DRYING OUT. THOUGH I DIDN`T MAKE ANY CHANGES TO LOW
TEMPERATURES...I AM WATCHING AN AREA OF CLOUDINESS SPREAD INTO THE
EASTERN GREAT LAKES ASSOCIATED WITH A CLIPPER-TYPE LOW OVER
MICHIGAN. RAP MODEL 925-700 MB RH RESOLVES THIS CLOUDINESS WELL
AND THE NORTHERN FRINGE OF HIGHER RH BRUSHES THE ADIRONDACKS AND
RUTLAND/WINDSOR COUNTIES AFTER MIDNIGHT. THE MAIN EFFECT THESE
CLOUDS MAY HAVE IS ON HOW COLD LOWS GET IN THE ADIRONDACKS.
THERE`S ALSO SOME PRETTY SIGNIFICANT DIFFERENCES IN MOS GUIDANCE
LOWS TONIGHT WITH THE LAV SHOWING LOWS ABOVE ZERO AT SLK WHILE THE
MAV AND MET LOWS ARE ALL BELOW ZERO. I`LL WAIT TO SEE HOW THE NEXT
COUPLE OF HOURS PLAYS OUT BEFORE MAKING ANY ADJUSTMENTS TO LOWS.
PREVIOUS NEAR-TERM DISCUSSION ISSUED AT 225 PM EDT FOLLOWS...
STILL DEALING WITH A FEW LIGHT SNOW SHOWERS ACROSS NORTHEAST
VERMONT THIS AFTERNOON...BUT THE GENERAL TREND WILL CONTINUE TO BE
TOWARDS DRIER WEATHER AS SURFACE HIGH PRESSURE BUILDS EASTWARD
FROM THE GREAT LAKES TONIGHT. A BROAD UPPER TROUGH STILL PERSISTS
ALOFT THOUGH AND WITH SHORTWAVE ENERGY PASSING TO OUR SOUTH
TONIGHT...THE MID LEVEL FLOW TURNS SOUTHWESTERLY ALLOWING SOME LOW
LEVEL MOISTURE TO RETURN TO THE NORTH COUNTRY TONIGHT.
THUS...WHILE CURRENT CLOUD COVER WILL LIKELY DISSIPATE TOWARDS 00Z
THIS EVENING...CLOUDS WILL FILL BACK IN FROM THE SOUTHWEST
OVERNIGHT. MID AND UPPER LEVELS ARE REALLY DRY SO FEEL DESPITE THE
LOW LEVEL CLOUDS...CONTINUED CAA ACROSS THE REGION WILL DROP TEMPS
INTO THE SINGLE DIGITS ABOVE ZERO FOR THE MAJORITY OF THE
REGION...WITH SOME BELOW ZERO READINGS POSSIBLE IN THE COLDER
HOLLOWS OF THE NORTHERN ADIRONDACKS AND NORTHEAST KINGDOM.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 225 PM EST THURSDAY...FOR FRIDAY...SURFACE HIGH PRESSURE
BUILDS INTO THE REGION WITH THE AFOREMENTIONED UPPER TROUGH
SLOWLY EXITING TO OUR EAST. MORNING CLOUD COVER WILL GENERALLY
DISSIPATE THROUGH THE DAY...BECOMING CLEAR BY FRIDAY NIGHT. IT`LL
REMAIN PRETTY COLD FOR LATE NOVEMBER WITH HIGHS ONLY A FEW
DEGREES WARMER THAN THURSDAY IN THE UPPER TEENS TO MID 20S...AND
LOWS COLDER FRIDAY NIGHT IN THE SINGLE DIGITS ABOVE AND BELOW
ZERO UNDER CLEAR SKIES AND LIGHT WINDS.
SATURDAY...HIGH PRESSURE SHIFTS OFFSHORE WITH SOUTHERLY RETURN
FLOW DEVELOPING WHICH WILL ALLOW TEMPS TO BEGIN TO MODERATE A
BIT. DRY CONDITIONS CONTINUE WITH PARTLY CLOUDY SKIES AND HIGHS
IN THE 20S EXPECTED. NEXT SYSTEM APPROACHES THE REGION LATE
SATURDAY NIGHT AS A WEAK UPPER TROUGH AND ASSOCIATED SHORTWAVE
ENERGY DROPS SOUTHEASTWARD OUT OF CENTRAL MANITOBA AND THROUGH
THE NORTHERN GREAT LAKES. LOOKS LIKE WE`RE IN FOR A CLASSIC HIGH
POP...LOW QPF SNOW EVENT AS THE SYSTEM LACKS ANY REAL DEEP
MOISTURE...AND WILL CARRY SOME MID-LEVEL 40-50% POPS AFTER
MIDNIGHT FOR SOME LIGHT SNOW.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 222 PM EST THURSDAY...UPPER LEVEL TROUGH MOVES OVER OR JUST
NORTH OF THE NORTH COUNTRY...BRINGING THREAT OF SNOW SHOWERS
THROUGH SUNDAY NIGHT. THIS WILL BE FOLLOWED BY RIDGE OF HIGH
PRESSURE AT THE SFC...THROUGH EARLY TUESDAY. SOUTHERLY STREAM
ENERGY IN BASE OF UPPER LVL TROUGH WILL DEVELOP INTO COASTAL
SYSTEM AT THE SFC. MODELS DIVERGE ON TRACK OF THIS SYSTEM...SO
HAVE KEPT LOW CHC POPS OVER THE REGION TUESDAY AND TUESDAY NIGHT
AS ECMWF KEEPS MOISTURE WRAPPING IN FROM THE ATLANTIC WITH SFC
LOW TRACKING OFF COAST OF CAPE COD. GFS SHOWING MORE RUN TO RUT
MODEL CONSISTENCY IN KEEPING THE LOW FAR OFF INTO THE ATLANTIC
WITH NORTH COUNTRY STAYING DRY. BEST CHCS FOR PRECIP WILL BE SRN
AND ERN VT. COASTAL LOW MOVES FURTHER OUT TO SEA ON
WEDNESDAY...RESULTING IN DRYING TREND BEFORE ANOTHER SYSTEM
APPROACHES FROM THE WEST. TEMPERATURES WILL BE BELOW NORMAL
THROUGHOUT THE PERIOD.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THROUGH 18Z FRIDAY...GENERALLY VFR CONDITIONS THROUGHOUT THE TAF
PERIOD...EXCEPT MVFR IN MOUNTAIN SNOW SHOWERS WHICH WILL BE
TAPERING OFF THIS AFTERNOON. KSLK AND AT TIMES KMPV STILL BEING
IMPACTED WITH SNOW SHOWERS AND MVFR CONDITIONS. EXPECT VFR
CONDITIONS THROUGHOUT THE NORTH COUNTRY AFTER 22Z. HEAVE KEPT
SOME VCSH AT KSLK THROUGHOUT THE EVENING AS SNOW SHOWERS ARE SLOW
TO ERODE. OTHERWISE...CLEARING SKIES THROUGH LATE FRIDAY MORNING.
SOME SCT MID LVL CLOUDS MAY MOVE OVER THE AREA OVERNIGHT WITH NO
IMPACTS.
GUSTY WNW WINDS WILL CONTINUE THIS AFTN WITH GUSTS UP TO ABOUT 25
KTS. GUSTS SUBSIDING AFTER 22Z-00Z WITH SUSTAINED WINDS OF 6-12
KTS. WINDS WILL CONTINUE TO SUBSIDE TO 5 KTS OR LESS OVERNIGHT.
WINDS PICKING UP AT 5-10KTS OUT OF THE NW MID TO LATE FRIDAY
MORNING.
OUTLOOK 18Z FRIDAY THROUGH TUESDAY...
18Z FRIDAY THROUGH 12Z SUNDAY...MAINLY VFR AS HIGH PRESSURE MOVES
ACROSS REGION.
12Z SUNDAY THROUGH 12Z MONDAY...VFR/MVFR IN SCATTERED SNOW
SHOWERS.
12Z MONDAY ONWARD...MAINLY VFR WITH RIDGE OF SFC HIGH PRESSURE
OVER THE AREA. SLGT CHC OF SHOWERS FOR SERN VT LATE TUESDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...LAHIFF/LOCONTO
SHORT TERM...LAHIFF
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
305 AM EST WED NOV 27 2013
.SYNOPSIS...
A STORM SYSTEM WILL MOVE THROUGH THE REGION TONIGHT THROUGH
WEDNESDAY NIGHT WITH A VARIETY OF MIXED...WINTRY PRECIPITATION.
THIS SYSTEM WILL LIKELY CAUSE DIFFICULT TO LOCALLY HAZARDOUS
TRAVEL ACROSS THE REGION. BEHIND THIS SYSTEM A RETURN TO COLD AND
MAINLY DRY CONDITIONS ARE EXPECTED BY FRIDAY AND INTO THE
UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1153 PM EST TUESDAY...GOING FORECAST IN REAL GOOD SHAPE AND
SEE NO REASON TO CHANGE ANYTHING AT THIS TIME. WARNINGS AND
ADVISORIES REMAIN IN PLACE.
.PREVIOUS FORECAST...
FORECAST REMAINS MORE OR LESS ON TRACK. SNOW CONTINUES ACROSS
MUCH OF THE REGION WITH ACCUMULATIONS SO FAR IN THE TRACE-2"
RANGE. RAP 850/925 MB 0C LINES STILL DOING QUITE WELL DEPICTING
THE CHANGEOVER FROM SNOW TO ICE/RAIN. AS OF 10PM...IT HAS
PROGRESSED TO NEAR WHITE RIVER JUNCTION VERMONT WESTWARD TO GLENS
FALLS AND STILL MOVING NORTHWARD. CHANGEOVER ACROSS THE REST OF
THE AREA EXCEPT THE SAINT LAWRENCE VALLEY BETWEEN NOW AND 07Z
FROM SOUTH TO NORTH. EXPECTING THE SAINT LAWRENCE VALLEY TO
REMAIN PRIMARILY SNOW. 1 TO 3" FOR MUCH OF CHAMPLAIN VALLEY AND
VERMONT BEFORE CHANGEOVER STILL LOOKS GOOD...WITH 2 TO 5" IN THE
ADIRONDACKS...AND 4 TO 8" IN THE SAINT LAWRENCE VALLEY BY
MORNING. ICE ACCRUAL OF UP TO A QUARTER OF AN INCH ALSO STILL
LOOKS GOOD FOR PORTIONS OF THE ADIRONDACKS AND EASTERN VERMONT.
OTHER CONCERN WILL BE SOME GUSTY SOUTHEAST DOWNSLOPE WINDS IN THE
SOUTHERN GREENS...WHERE GUSTS UP TO 40 MPH ARE POSSIBLE
OVERNIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH FRIDAY/...
AS OF 315 PM EST TUESDAY...MODESTLY DEEP SFC LOW THEN TRACKS ATOP
OR JUST EAST OF THE FORECAST AREA DURING WEDNESDAY. THUS
EXPECTING MAINLY A WIDESPREAD RAIN EVENT ACROSS VT AND CONTINUED
ACCUMULATING WINTRY PCPN FROM THE DACKS INTO THE SLV AS MEAN
925/850 MB 0C LINE BACKS WESTWARD. COPIOUS MOISTURE FEED...ESP
ALONG AND EAST OF THE LOW TRACK SEEMS A GOOD BET WITH MEAN MODEL
PWAT ANOMALIES RANGING FROM 200-300% OF NORMAL OCCURRING ACROSS
THE ERN HALF OF VERMONT DURING THE DAYLIGHT HOURS. THIS WILL
CREATE SOME MODEST HYDROLOGICAL CONCERNS IN THESE AREAS WITH
ADDITIONAL SUPPORT COMING FROM TIGHT BAROCLINICITY AND DEEP
FRONTOGENETICAL FORCING (SEE HYDRO SECTION BELOW). TEMPERATURES
ALL OVER THE PLACE...WITH NRN NY COUNTIES HOLDING MAINLY IN THE
LOWER TO MID 30S WHILE AREAS ACROSS FAR EASTERN VERMONT SHOULD
EASILY MAKE IT INTO THE LOWER AND MID 40S WITH A SPOT 50 NOT OUT
OF THE QUESTION FROM WHITE RIVER JCT SOUTH.
AS THE LOW SWINGS BY WEDNESDAY EVENING/NIGHT...THE LOWER TO MID
LEVEL 0C LINE WILL BEGIN TO ADVANCE RAPIDLY EASTWARD SUCH THAT
PCPN WILL RATHER QUICKLY TRANSITION BACK TO SNOW FROM EAST TO
WEST DURING THE 00-06Z TIME FRAME. THUS ADDITIONAL SNOW
ACCUMULATIONS EXPECTED IN ALL AREAS...ESP NORTHERN MTNS WHERE
TYPICAL OROGRAPHICAL EFFECTS WILL ENHANCE LOCAL RATES.
TEMPERATURES CRASHING SHARPLY DURING THE PERIOD AS WELL SO SOME
QUICK FREEZE-UP OF AREA ROADS CERTAINLY POSSIBLE...SIMILAR TO A
FEW NIGHTS BACK. READINGS BY MORNING GENERALLY FROM 10 TO 20 WITH
A GUSTY WNW WIND.
BY THURSDAY LINGERING NRN MTN SHSN SLOWLY WANE THROUGH THE DAY AS
HIGH PRESSURE NOSES EASTWARD AND SUNSHINE BECOMES MORE AND MORE
PREVALENT. QUITE A COLD/BLUSTERY DAY HOWEVER AS TEMPERATURES HOLD
MORE OR LESS STEADY FROM 15 TO 25 UNDER STRONG COLD THERMAL
ADVECTION AND CONTINUED GUSTY WNW FLOW.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 304 AM EST WEDNESDAY...MAINLY WENT WITH THE SUPERBLEND FOR
THE EXTENDED PORTION OF THE FORECAST THIS MORNING SO THAT MORE
FOCUS COULD BE ON THE NEAR/SHORT TERM PORTIONS OF THE FORECAST.
FRIDAY NIGHT AND SATURDAY WILL BE DRY WITH RIDGE OF SURFACE HIGH
PRESSURE OVER THE AREA AND THEN SLOWLY SLIDING EAST. FROM
SATURDAY NIGHT THROUGH SUNDAY NIGHT A WEAK LOW PRESSURE SYSTEM
WILL PASS EITHER JUST NORTH OF OUR AREA OR ACROSS OUR FORECAST
AREA BRINGING SNOW SHOWERS TO THE NORTH COUNTRY. MONDAY AND
MONDAY NIGHT WILL GENERALLY BE DRY. A LOW PRESSURE SYSTEM TRACKS
ALONG THE EAST COAST IN THE TUESDAY THROUGH WEDNESDAY TIMEFRAME.
GFS AND ECMWF STILL QUITE DIFFERENT WITH TRACK AND TIMING OF THIS
STORM...BUT STILL FAR OUT TO DETERMINE THOSE DETAILS. AT THIS
TIME LOOKS LIKE SOME PRECIP WILL AFFECT OUR FORECAST AREA TUESDAY
AND TUESDAY NIGHT...THEN WINDING DOWN EARLY WEDNESDAY. RIGHT NOW
IT LOOKS LIKE RAIN...BUT AGAIN...LOTS OF UNCERTAINTY AT THIS
POINT AND AS WE GET CLOSER TO NEXT WEEK THE DETAILS WILL BECOME
MORE CLEAR AND OF COURSE THE MODELS SHOULD COME MORE INTO LINE.
TEMPERATURES WILL INITIALLY BE BELOW NORMAL BUT THEN TREND BACK
TOWARDS NORMAL LATER IN THE PERIOD.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...WIDESPREAD IFR WITH AREAS OF MVFR EXPECTED
THROUGH THE PERIOD. SNOW HAS BEGUN TO TRANSITION TO RAIN OVER THE
LAST HOUR OR TWO AT ALL SITES EXCEPT KMSS AND KSLK. ALMOST ALL
TERMINALS IN VT REPORTING RAIN AT THIS TIME...AS WELL AS PBG. MIX
CONTINUES AT KSLK WITH SNOW AT KMSS...WHICH MAY BE HEAVY AT
TIMES. PRECIPITATION THEN TRANSITIONS BACK TO SNOW FROM WEST TO
EAST ACROSS THE AREA WEDNESDAY AFTERNOON.
STRONG LOW LVL JET WILL APPROACH EASTERN VT...CREATING LLWS OF
40-50KTS FOR KRUT AND KMPV BETWEEN 08Z-14Z. AT THE SFC...WINDS
WILL BE LESS THAN 10 KTS TONIGHT AT ALL SITES EXCEPT KRUT WHICH
WILL SEE SOUTHEAST WINDS GUSTING 20-25 KTS. WINDS BECOMING
NORTHERLY 8-15 KTS ACROSS THE REGION ON WEDNESDAY AS SFC LOW
TRACKS FROM NEAR NYC WEDNESDAY MORNING INTO EASTERN NEW ENGLAND.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
06Z THURSDAY THROUGH 18Z THURSDAY...MVFR AND IFR CATEGORIES
CONTINUE INTO THANKSGIVING MORNING. SNOW WEDNESDAY EVENING 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 THROUGH 12Z SUNDAY...MAINLY VFR AS HIGH PRESSURE
MOVES ACROSS REGION.
12Z SUNDAY ONWARD...VFR/MVFR IN SCATTERED SNOW SHOWERS.
&&
.HYDROLOGY...
AS OF 315 PM EST TUESDAY...SREF MEAN AND PLUME OUTPUT ALONG WITH
GLOBAL BLENDED SOLUTIONS CONTINUE TO SUGGEST A DECENT QPF EVENT
ACROSS OUR AREA. HEAVIEST PCPN SHOULD FALL ACROSS OUR EASTERN AND
SOUTHERN VT COUNTIES WHERE A SOLID 1.5 TO 2.5 QPF EVENT IS
LIKELY. PROBLEMATIC WILL BE AT LEAST SOME FRONT END FROZEN PCPN
TONIGHT AND TYPICAL SHADOWING EFFECTS DEPENDING ON LOCALE DURING
WEDNESDAY. HOWEVER SSHP OUTPUT USING FORECAST QPF FROM 06Z-00Z
WED AND INCORPORATING A MODEST 0.15 TO 0.25 SWE MELT SHOW SEVERAL
EASTERN/SOUTHERN VT WATERSHEDS NEARING BANKFULL LATER WED/WED
NIGHT. THIS IS IN CLOSE AGREEMENT WITH COORDINATED NERFC/AHPS
FORECASTS AND GIVEN ANOMALOUS 12-HR PWAT SURGE NOTED ABOVE...HAVE
OPTED TO ISSUE A FLOOD WATCH FOR MUCH OF THIS AREA ACCORDINGLY.
THIS IS NOT A HIGH END EVENT...BUT SOME MINOR/NUISANCE FLOODING
ALONG BOTH HEADWATER AND MAINSTEM RIVERS WILL BE POSSIBLE LATER
WED/WED NT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
VTZ001>012-016>019.
FLOOD WATCH FROM 7 AM EST THIS MORNING THROUGH LATE TONIGHT
FOR VTZ004-007-008-010>012-018-019.
NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ026-027-
029>031-034-087.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...EVENSON/MUCCILLI
SHORT TERM...JMG
LONG TERM...NEILES
AVIATION...NEILES
HYDROLOGY...JMG
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1238 AM EST WED NOV 27 2013
.SYNOPSIS...
A STORM SYSTEM WILL MOVE THROUGH THE REGION TONIGHT THROUGH
WEDNESDAY NIGHT WITH A VARIETY OF MIXED...WINTRY PRECIPITATION.
THIS SYSTEM WILL LIKELY CAUSE DIFFICULT TO LOCALLY HAZARDOUS
TRAVEL ACROSS THE REGION. BEHIND THIS SYSTEM A RETURN TO COLD AND
MAINLY DRY CONDITIONS ARE EXPECTED BY FRIDAY AND INTO THE
UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1153 PM EST TUESDAY...GOING FORECAST IN REAL GOOD SHAPE AND
SEE NO REASON TO CHANGE ANYTHING AT THIS TIME. WARNINGS AND
ADVISORIES REMAIN IN PLACE.
.PREVIOUS FORECAST...
FORECAST REMAINS MORE OR LESS ON TRACK. SNOW CONTINUES ACROSS
MUCH OF THE REGION WITH ACCUMULATIONS SO FAR IN THE TRACE-2"
RANGE. RAP 850/925 MB 0C LINES STILL DOING QUITE WELL DEPICTING
THE CHANGEOVER FROM SNOW TO ICE/RAIN. AS OF 10PM...IT HAS
PROGRESSED TO NEAR WHITE RIVER JUNCTION VERMONT WESTWARD TO GLENS
FALLS AND STILL MOVING NORTHWARD. CHANGEOVER ACROSS THE REST OF
THE AREA EXCEPT THE SAINT LAWRENCE VALLEY BETWEEN NOW AND 07Z
FROM SOUTH TO NORTH. EXPECTING THE SAINT LAWRENCE VALLEY TO
REMAIN PRIMARILY SNOW. 1 TO 3" FOR MUCH OF CHAMPLAIN VALLEY AND
VERMONT BEFORE CHANGEOVER STILL LOOKS GOOD...WITH 2 TO 5" IN THE
ADIRONDACKS...AND 4 TO 8" IN THE SAINT LAWRENCE VALLEY BY
MORNING. ICE ACCRUAL OF UP TO A QUARTER OF AN INCH ALSO STILL
LOOKS GOOD FOR PORTIONS OF THE ADIRONDACKS AND EASTERN VERMONT.
OTHER CONCERN WILL BE SOME GUSTY SOUTHEAST DOWNSLOPE WINDS IN THE
SOUTHERN GREENS...WHERE GUSTS UP TO 40 MPH ARE POSSIBLE
OVERNIGHT.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 315 PM EST TUESDAY...MODESTLY DEEP SFC LOW THEN TRACKS ATOP
OR JUST EAST OF THE FORECAST AREA DURING WEDNESDAY. THUS
EXPECTING MAINLY A WIDESPREAD RAIN EVENT ACROSS VT AND CONTINUED
ACCUMULATING WINTRY PCPN FROM THE DACKS INTO THE SLV AS MEAN
925/850 MB 0C LINE BACKS WESTWARD. COPIOUS MOISTURE FEED...ESP
ALONG AND EAST OF THE LOW TRACK SEEMS A GOOD BET WITH MEAN MODEL
PWAT ANOMALIES RANGING FROM 200-300% OF NORMAL OCCURRING ACROSS
THE ERN HALF OF VERMONT DURING THE DAYLIGHT HOURS. THIS WILL
CREATE SOME MODEST HYDROLOGICAL CONCERNS IN THESE AREAS WITH
ADDITIONAL SUPPORT COMING FROM TIGHT BAROCLINICITY AND DEEP
FRONTOGENETICAL FORCING (SEE HYDRO SECTION BELOW). TEMPERATURES
ALL OVER THE PLACE...WITH NRN NY COUNTIES HOLDING MAINLY IN THE
LOWER TO MID 30S WHILE AREAS ACROSS FAR EASTERN VERMONT SHOULD
EASILY MAKE IT INTO THE LOWER AND MID 40S WITH A SPOT 50 NOT OUT
OF THE QUESTION FROM WHITE RIVER JCT SOUTH.
AS THE LOW SWINGS BY WEDNESDAY EVENING/NIGHT...THE LOWER TO MID
LEVEL 0C LINE WILL BEGIN TO ADVANCE RAPIDLY EASTWARD SUCH THAT
PCPN WILL RATHER QUICKLY TRANSITION BACK TO SNOW FROM EAST TO
WEST DURING THE 00-06Z TIME FRAME. THUS ADDITIONAL SNOW
ACCUMULATIONS EXPECTED IN ALL AREAS...ESP NORTHERN MTNS WHERE
TYPICAL OROGRAPHICAL EFFECTS WILL ENHANCE LOCAL RATES.
TEMPERATURES CRASHING SHARPLY DURING THE PERIOD AS WELL SO SOME
QUICK FREEZE-UP OF AREA ROADS CERTAINLY POSSIBLE...SIMILAR TO A
FEW NIGHTS BACK. READINGS BY MORNING GENERALLY FROM 10 TO 20 WITH
A GUSTY WNW WIND.
BY THURSDAY LINGERING NRN MTN SHSN SLOWLY WANE THROUGH THE DAY AS
HIGH PRESSURE NOSES EASTWARD AND SUNSHINE BECOMES MORE AND MORE
PREVALENT. QUITE A COLD/BLUSTERY DAY HOWEVER AS TEMPERATURES HOLD
MORE OR LESS STEADY FROM 15 TO 25 UNDER STRONG COLD THERMAL
ADVECTION AND CONTINUED GUSTY WNW FLOW.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 246 PM EST TUESDAY...SFC HIGH PRESSURE WITH GRADUALLY CLEAR
SKIES AS AN UPPER LVL TROUGH EXITS EAST ON FRIDAY. RIDGING AT THE
SFC...AND SLGT RIDGING ALOFT WILL KEEP DRY AIR OVER THE REGION
THROUGH EARLY SUNDAY. COLD TEMPERATURES FRIDAY AND FRIDAY NIGHT
WILL BE MODERATED BY RETURN FLOW ON SATURDAY AS THE SFC HIGH
SHIFTS EWD TOWARD NOVA SCOTIA. MAX TEMPS IN THE TEENS AND 20S ON
FRIDAY WITH MIN TEMPS IN THE SINGLE DIGITS...AND NEGATIVE SINGLE
DIGITS WILL WARM INTO THE TEENS SATURDAY NT AND 20S-M30S ON
SUNDAY.
UPPER LVL SHORTWAVE WILL BRING CLOUDS AND CHC FOR SNOW SUNDAY
INTO EARLY MONDAY WITH THE POSSIBILITY OF A COASTAL STORM
DEVELOPING MONDAY NT INTO TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...WIDESPREAD IFR WITH AREAS OF MVFR EXPECTED
THROUGH THE PERIOD. SNOW HAS BEGUN TO TRANSITION TO RAIN OVER THE
LAST HOUR OR TWO AT ALL SITES EXCEPT KMSS AND KSLK. ALMOST ALL
TERMINALS IN VT REPORTING RAIN AT THIS TIME...AS WELL AS PBG. MIX
CONTINUES AT KSLK WITH SNOW AT KMSS...WHICH MAY BE HEAVY AT
TIMES. PRECIPITATION THEN TRANSITIONS BACK TO SNOW FROM WEST TO
EAST ACROSS THE AREA WEDNESDAY AFTERNOON.
STRONG LOW LVL JET WILL APPROACH EASTERN VT...CREATING LLWS OF
40-50KTS FOR KRUT AND KMPV BETWEEN 08Z-14Z. AT THE SFC...WINDS
WILL BE LESS THAN 10 KTS TONIGHT AT ALL SITES EXCEPT KRUT WHICH
WILL SEE SOUTHEAST WINDS GUSTING 20-25 KTS. WINDS BECOMING
NORTHERLY 8-15 KTS ACROSS THE REGION ON WEDNESDAY AS SFC LOW
TRACKS FROM NEAR NYC WEDNESDAY MORNING INTO EASTERN NEW ENGLAND.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
06Z THURSDAY THROUGH 18Z THURSDAY...MVFR AND IFR CATEGORIES
CONTINUE INTO THANKSGIVING MORNING. SNOW WEDNESDAY EVENING 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 THROUGH 12Z SUNDAY...MAINLY VFR AS HIGH PRESSURE
MOVES ACROSS REGION.
12Z SUNDAY ONWARD...VFR/MVFR IN SCATTERED SNOW SHOWERS.
&&
.HYDROLOGY...
AS OF 315 PM EST TUESDAY...SREF MEAN AND PLUME OUTPUT ALONG WITH
GLOBAL BLENDED SOLUTIONS CONTINUE TO SUGGEST A DECENT QPF EVENT
ACROSS OUR AREA. HEAVIEST PCPN SHOULD FALL ACROSS OUR EASTERN AND
SOUTHERN VT COUNTIES WHERE A SOLID 1.5 TO 2.5 QPF EVENT IS
LIKELY. PROBLEMATIC WILL BE AT LEAST SOME FRONT END FROZEN PCPN
TONIGHT AND TYPICAL SHADOWING EFFECTS DEPENDING ON LOCALE DURING
WEDNESDAY. HOWEVER SSHP OUTPUT USING FORECAST QPF FROM 06Z-00Z
WED AND INCORPORATING A MODEST 0.15 TO 0.25 SWE MELT SHOW SEVERAL
EASTERN/SOUTHERN VT WATERSHEDS NEARING BANKFULL LATER WED/WED
NIGHT. THIS IS IN CLOSE AGREEMENT WITH COORDINATED NERFC/AHPS
FORECASTS AND GIVEN ANOMALOUS 12-HR PWAT SURGE NOTED ABOVE...HAVE
OPTED TO ISSUE A FLOOD WATCH FOR MUCH OF THIS AREA ACCORDINGLY.
THIS IS NOT A HIGH END EVENT...BUT SOME MINOR/NUISANCE FLOODING
ALONG BOTH HEADWATER AND MAINSTEM RIVERS WILL BE POSSIBLE LATER
WED/WED NT.
&&
.MARINE...
AS OF 1030 PM EST TUESDAY...A LAKE WIND ADVISORY IS NO LONGER IN
EFFECT AS WINDS HAVE DROPPED BELOW ADVISORY CRITERIA. FOR THE
REST OF TONIGHT WINDS WILL BE SOUTH AT 10 TO 20 KNOTS...BECOMING
EAST TO NORTHEAST AT 5 TO 15 KNOTS TOWARDS MORNING. THE LULL IN
THE WINDS WILL BE BRIEF HOWEVER. A COLD FRONT WILL PASS THROUGH
THE REGION WEDNESDAY AFTERNOON AND WINDS WILL SHIFT TO THE
NORTHWEST AND BECOME STRONG AGAIN AT 25-35 KNOTS WEDNESDAY
EVENING...WITH WAVES BUILDING TO 4 TO 6 FEET WEDNESDAY NIGHT.
ANOTHER ADVISORY WILL LIKELY BE NEEDED FOR WEDNESDAY NIGHT INTO
THANKSGIVING DAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR
VTZ001>012-016>019.
FLOOD WATCH FROM 7 AM EST THIS MORNING THROUGH LATE TONIGHT
FOR VTZ004-007-008-010>012-018-019.
NY...WINTER STORM WARNING UNTIL 7 AM EST THURSDAY FOR NYZ026-027-
029>031-034-087.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR NYZ028-
035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...EVENSON/MUCCILLI
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...RJS/NEILES
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
909 PM CST THU NOV 28 2013
.UPDATE...
ISSUED AT 851 PM CST THU NOV 28 2013
CLOUDS AND TEMPERATURES CONTINUE TO BE THE MAIN ISSUES TONIGHT.
COOL HIGH PRESSURE ACROSS MINNESOTA WITH A WARM FRONTAL BOUNDARY
ACROSS MONTANA. THE TREND HAS BEEN CLEARING SKIES BUT LATEST
SATELLITE PICTURES SUGGEST CLOUDS MAYBE REFORMING ACROSS CENTRAL
NORTH DAKOTA NORTH OF LAKE SAKAKAWEA. NOW WILL BE TRENDING THE
CLOUDS BACK INTO THE PICTURE TONIGHT. ALSO TEMPERATURES MAY HIT
THEIR LOWS LATE THIS EVENING OR EARLY AFTER MIDNIGHT THEN BECOME
STEADY OR RISE A BIT BY MORNING...ESPECIALLY JAMES RIVER VALLEY
NORTH TO THE DEVILS LAKE BASIN. DO NOT SEE ANY PRECIP IN THE
FORECAST FOR TONIGHT AS THE FLURRIES FROM THURSDAY AFTERNOON HAVE
ENDED.
UPDATE ISSUED AT 541 PM CST THU NOV 28 2013
AT 5 PM CST...SURFACE HIGH PRESSURE EXTENDED ACROSS THE EASTERN
DAKOTAS. A SURFACE TROUGH AND ASSOCIATED WARM FRONT EXTENDED
THROUGH CENTRAL MONTANA. THE THIN LAYER OF STRATUS HAS ERODED
IN WEAK LOW LEVEL WARM ADVECTION...LEAVING NARROW BANDS OF CLOUDS
ACROSS CENTRAL NORTH DAKOTA WITH THE WEST GENERALLY MOSTLY CLEAR.
CURRENT THINKING IS THE CLOUDS WILL EVENTUALLY BACK FILL IN WITH
SHALLOW COOL AIR IN PLACE AS THE WARM FRONT MOVES EAST. SOME
UNCERTAINTY HERE ALSO...AS LOW LEVEL WARM ADVECTION AT H850 MAY
SUPPRESS CLOUDS LATER TONIGHT. BUT WENT WITH AN INCREASE IN CLOUDS
THROUGH MIDNIGHT....THEN CLOUDY AFTER MIDNIGHT. CURRENT
TEMPERATURES AND WINDS SEEM OK FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE SKY COVER
TONIGHT AND IMPACT ON TEMPERATURES.
PORTIONS OF THE STRATUS DECK HAVE ERODED ACROSS THE FORECAST AREA
THIS AFTERNOON. RAP 925MB RELATIVE HUMIDITY HAS THIS MODELED
RELATIVELY WELL AND SUGGEST THAT STRATUS SHOULD FILL BACK IN THIS
EVENING AND OVERNIGHT. TEMPERATURES WILL LIKELY DROP QUICKLY THIS
EVENING IN CLOUD FREE AREAS...BEFORE THE STRONGER SE WINDS
DEVELOP. THE STRONGER GRADIENT WILL BE LOCATED OVER THE WEST AND
HAVE KEPT OVERNIGHT LOWS RELATIVELY MILD...IN THE TEENS TO LOWER
20S. EAST/NORTHEAST PORTIONS OF THE FORECAST AREA...FROM THE
TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...SHOULD BE ABLE
TO GET INTO THE SINGLE DIGITS. HOURLY TRENDS WILL LIKELY NEED TO
BE UPDATED THIS EVENING.
ON FRIDAY...STRONGER WARM AIR ADVECTION WILL KICK IN...WITH HIGHS
IN THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE RETURN OF ARCTIC AIR
AND THE POTENTIAL FOR WIDESPREAD ACCUMULATING SNOW NEXT WEEK.
THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON A SIGNIFICANT
UPPER LEVEL LOW COMING ONSHORE TO THE PACIFIC NORTHWEST ON MONDAY.
THEREAFTER...UNCERTAINTY INCREASES IN REGARDS TO THE EVOLUTION AND
PROPAGATION OF THIS LOW ACROSS THE INTERMOUNTAIN WEST AND
POTENTIALLY INTO THE NORTHERN PLAINS LATE TUESDAY AND INTO
WEDNESDAY. THE 12 UTC ECMWF CONTINUES THE TREND OF ITS PREVIOUS
RUNS OVER THE PAST 24 HOURS OF THE DEEPEST LOW YIELDING
SIGNIFICANT QPF AND SNOW ACROSS THE NORTHERN PLAINS TUESDAY INTO
WEDNESDAY. THE 12 UTC GFS HAS TRENDED MORE TOWARDS THE
ECMWF...HOWEVER...IS NOT AS DEEP WITH LESSER QPF...MUCH LIKE THE
12 UTC GEM. THE ECMWF HAS BEEN THE MOST CONSISTENT AND IS
SUPPORTED BY THE GEFS MEAN...AND FAVORED BY WPC. THUS...WILL
CONTINUE TO MONITOR THE POTENTIAL FOR ACCUMULATING SNOW NEXT WEEK.
NO MATTER THE MODEL...ARCTIC AIR IS FORECAST TO OVERTAKE THE
NORTHERN PLAINS ONCE AGAIN TUESDAY THROUGH THE END OF NEXT WEEK
WITH A PATTERN SHIFT TO BROAD WESTERN AND CENTRAL CONUS UPPER
LEVEL TROUGHING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 851 PM CST THU NOV 28 2013
THIS TAF PERIOD IS COMPLICATED BECAUSE OF UNCERTAINTY CONCERNING THE
CEILING FORECAST. SO FAR THIS THURSDAY EVENING...THE TREND HAS
BEEN CLEARING SKIES AND VFR CONDITIONS THROUGHOUT WEST AND CENTRAL
NORTH DAKOTA. HOWEVER...WITH SHALLOW COOL AIR IN PLACE...A WARM
FRONT IN MONTANA THAT WILL BRING OVER RUNNING WARM AIR OVER THE
COOL AIR IN NORTH DAKOTA...SHOULD SUPPORT THE REDEVELOPMENT OF CLOUDS
AND MVFR CEILINGS ACROSS WEST AND CENTRAL NORTH DAKOTA AROUND OR
SHORTLY AFTER 06Z. TIMING AND THE EXTEND OF THE CLOUDS ARE
SOMEWHAT UNCERTAIN...BUT EXPECT WIDESPREAD MVFR CEILINGS TO
DEVELOP FROM KISN-KDIK-KBIS-KMOT-KJMS BETWEEN 06-10Z. CONDITIONS
WILL GENERALLY IMPROVE TO VFR AGAIN FRIDAY AFTER 16-18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
LONG TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
600 PM CST THU NOV 28 2013
.UPDATE...
ISSUED AT 541 PM CST THU NOV 28 2013
AT 5 PM CST...SURFACE HIGH PRESSURE EXTENDED ACROSS THE EASTERN
DAKOTAS. A SURFACE TROUGH AND ASSOCIATED WARM FRONT EXTENDED
THROUGH CENTRAL MONTANA. THE THIN LAYER OF STRATUS HAS ERODED
IN WEAK LOW LEVEL WARM ADVECTION...LEAVING NARROW BANDS OF CLOUDS
ACROSS CENTRAL NORTH DAKOTA WITH THE WEST GENERALLY MOSTLY CLEAR.
CURRENT THINKING IS THE CLOUDS WILL EVENTUALLY BACK FILL IN WITH
SHALLOW COOL AIR IN PLACE AS THE WARM FRONT MOVES EAST. SOME
UNCERTAINTY HERE ALSO...AS LOW LEVEL WARM ADVECTION AT H850 MAY
SUPPRESS CLOUDS LATER TONIGHT. BUT WENT WITH AN INCREASE IN CLOUDS
THROUGH MIDNIGHT....THEN CLOUDY AFTER MIDNIGHT. CURRENT
TEMPERATURES AND WINDS SEEM OK FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE SKY COVER
TONIGHT AND IMPACT ON TEMPERATURES.
PORTIONS OF THE STRATUS DECK HAVE ERODED ACROSS THE FORECAST AREA
THIS AFTERNOON. RAP 925MB RELATIVE HUMIDITY HAS THIS MODELED
RELATIVELY WELL AND SUGGEST THAT STRATUS SHOULD FILL BACK IN THIS
EVENING AND OVERNIGHT. TEMPERATURES WILL LIKELY DROP QUICKLY THIS
EVENING IN CLOUD FREE AREAS...BEFORE THE STRONGER SE WINDS
DEVELOP. THE STRONGER GRADIENT WILL BE LOCATED OVER THE WEST AND
HAVE KEPT OVERNIGHT LOWS RELATIVELY MILD...IN THE TEENS TO LOWER
20S. EAST/NORTHEAST PORTIONS OF THE FORECAST AREA...FROM THE
TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...SHOULD BE ABLE
TO GET INTO THE SINGLE DIGITS. HOURLY TRENDS WILL LIKELY NEED TO
BE UPDATED THIS EVENING.
ON FRIDAY...STRONGER WARM AIR ADVECTION WILL KICK IN...WITH HIGHS
IN THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE RETURN OF ARCTIC AIR
AND THE POTENTIAL FOR WIDESPREAD ACCUMULATING SNOW NEXT WEEK.
THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON A SIGNIFICANT
UPPER LEVEL LOW COMING ONSHORE TO THE PACIFIC NORTHWEST ON MONDAY.
THEREAFTER...UNCERTAINTY INCREASES IN REGARDS TO THE EVOLUTION AND
PROPAGATION OF THIS LOW ACROSS THE INTERMOUNTAIN WEST AND
POTENTIALLY INTO THE NORTHERN PLAINS LATE TUESDAY AND INTO
WEDNESDAY. THE 12 UTC ECMWF CONTINUES THE TREND OF ITS PREVIOUS
RUNS OVER THE PAST 24 HOURS OF THE DEEPEST LOW YIELDING
SIGNIFICANT QPF AND SNOW ACROSS THE NORTHERN PLAINS TUESDAY INTO
WEDNESDAY. THE 12 UTC GFS HAS TRENDED MORE TOWARDS THE
ECMWF...HOWEVER...IS NOT AS DEEP WITH LESSER QPF...MUCH LIKE THE
12 UTC GEM. THE ECMWF HAS BEEN THE MOST CONSISTENT AND IS
SUPPORTED BY THE GEFS MEAN...AND FAVORED BY WPC. THUS...WILL
CONTINUE TO MONITOR THE POTENTIAL FOR ACCUMULATING SNOW NEXT WEEK.
NO MATTER THE MODEL...ARCTIC AIR IS FORECAST TO OVERTAKE THE
NORTHERN PLAINS ONCE AGAIN TUESDAY THROUGH THE END OF NEXT WEEK
WITH A PATTERN SHIFT TO BROAD WESTERN AND CENTRAL CONUS UPPER
LEVEL TROUGHING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 541 PM CST THU NOV 28 2013
COMPLEX CEILING FORECAST TONIGHT WITH SOME UNCERTAINTY. AT 5 PM
CST...HIGH PRESSURE REMAINED ACROSS THE EASTERN DAKOTAS WITH A
WARM FRONTAL BOUNDARY IN MONTANA SLOWLY MOVING EAST TONIGHT.
LATEST CLOUD TRENDS HAVE CLOUDS THINNING AND CLEARING G OVER
WESTERN NORTH DAKOTA...WITH A BAND OF MVFR CEILINGS THROUGH
CENTRAL NORTH DAKOTA IMPACTING KBIS-KMOT-KJMS THIS EVENING.
BELIEVER MVFR CLOUDS WILL RETURN TO ALL OF WEST AND CENTRAL NORTH
DAKOTA BETWEEN 03Z-06Z...RESULTING IN MAINLY MVFR CEILINGS ACROSS
THE REGION. CONDITIONS SLOWLY IMPROVING TO VFR AFTER 16Z
FRIDAY...ALTHOUGH THEY MAY LINGER LONGER IN KMOT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
LONG TERM...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
109 PM CST WED NOV 27 2013
.UPDATE...
ISSUED AT 1241 PM CST WED NOV 27 2013
MADE SOME ADJUSTMENTS TO MIDDAY TEMPS AND SKY COVER. STRATUS WILL
CONTINUE TO MOVE SOUTH INTO THE FORECAST AREA THIS AFTERNOON WITH
A FEW FLURRIES. WIND TRAJECTORIES SUGGEST LAKE ENHANCED MOISTURE
MAY ALSO CONTRIBUTE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST WED NOV 27 2013
CURRENTLY...SURFACE LOW PRESSURE WAS CENTERED OVER SOUTHWESTERN
SASKATCHEWAN/NORTH CENTRAL MONTANA. SOUTH WINDS AHEAD OF THE SYSTEM
HAD DEVELOPED OVER WESTERN AND CENTRAL NORTH DAKOTA DURING THE
EVENING HOURS...AND STRONG WARM ADVECTION CONTINUED OVER THE WESTERN
HALF OF NORTH DAKOTA AHEAD OF THIS SYSTEM. REGARDING
TEMPERATURES...READINGS HAD RISEN INTO THE LOWER 20S ACROSS FAR
WESTERN NORTH DAKOTA...AND INTO THE TEENS OVER WESTERN PORTIONS OF
CENTRAL NORTH DAKOTA. THIS TREND OF RISING TEMPERATURES SHOULD
CONTINUE EASTWARD THROUGH SUNRISE.
ALONG WITH THE WARM ADVECTION...IT APPEARS THAT THE RUC MODEL HAS A
VERY GOOD HANDLE ON H850 TO H700 LIFTING OCCURRING OVER SOUTHEASTERN
SASKATCHEWAN/SOUTHWEST MANITOBA/NORTHERN NORTH DAKOTA. THIS MODEL
WAS DEPICTING LIGHT PRECIPITATION OVER THIS SAME AREA AROUND
MIDNIGHT...AND IT CONTINUES/ADVECTS IT EASTWARD DURING THE REST OF
THE NIGHTTIME HOURS. CURRENT RADAR LOOPS VALIDATING AT LEAST SOME
ENHANCED CLOUDS AND/OR LIFT OCCURRING...SO WILL KEEP A MENTION OF
FLURRIES FOR THIS TIME PERIOD OVER NORTH CENTRAL TO THE JAMESTOWN
AREA THROUGH SUNRISE.
THE 06Z NAM AS WELL AS THE 00Z ECMWF AND GFS MODELS ARE NOW
DEPICTING LIGHT PRECIPITATION OVER NORTHEASTERN NORTH DAKOTA FROM 6
AM TO NOON TIME FRAME. THIS APPEARS TO BE THE RESULT OF BOTH WARM
ADVECTION LIFTING AT H850/H700 AS WELL AS REINFORCEMENT FROM AN
UPPER LEVEL SHORTWAVE MOVING SOUTHEAST OUT OF MANITOBA. ADDED A
MENTION OF CHANCE OF LIGHT SNOW THIS MORNING IN THE BOTTINEAU/TURTLE
MOUNTAIN/HARVEY AREA.
CONTINUED WARM ADVECTION THROUGH THE DAY UNTIL A COLD FRONT DIVES
SOUTHEAST OUT OF SASKATCHEWAN THIS AFTERNOON SWEEPING ACROSS THE
STATE AND REACHING THE JAMES RIVER VALLEY LATE AFTERNOON/EVENING.
SOUTH WINDS AHEAD OF THE FRONT WILL BECOME NORTHWEST AT AROUND 15
MPH. EXPECTING HIGH TEMPERATURES TO REACH INTO THE 20S OVER
NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THROUGH THE JAMES RIVER
VALLEY...WITH TEMPERATURES IN THE 30S MAINLY SOUTH AND WEST OF THE
MISSOURI RIVER. THE FAR SOUTHWEST MAY SEE TEMPERATURES REACH INTO
THE LOWER 40S.
THE COLD FRONT WILL BE FOLLOWED BY ANOTHER ARCTIC HIGH PRESSURE
SYSTEM...AND EXPECTING LOWS TONIGHT FROM THE SINGLE DIGITS NORTH TO
LOWER TEENS SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 350 AM CST WED NOV 27 2013
FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BY MAINLY DRY
CONDITIONS THROUGH SATURDAY NIGHT...FOLLOWED BY A POSSIBLE VERY
ACTIVE WEATHER PERIOD SOMETIME FROM SUNDAY INTO THE MIDDLE
PORTIONS OF NEXT WEEK.
THE EXTENDED PERIOD BEGINS THURSDAY MORNING WITH STRONG NORTHWEST
FLOW ALOFT OVER THE NORTHERN PLAINS AND A SFC RIDGE OF HIGH
PRESSURE EXTENDING FROM NORTH OF MANITOBA SOUTH THROUGH THE
DAKOTAS. BOTH THE 00Z NAM/GFS CONTINUE TO INDICATE LOW STRATUS
FROM WEDNESDAY NIGHT PERSISTING INTO THURSDAY MORNING ACROSS MUCH
OF WEST AND CENTRAL NORTH DAKOTA WITH THE SFC RIDGE. COUPLED WITH
SUBTLE MID/UPPER LEVEL SUPPORT...OPTED TO CONTINUE THE ISOLATED
FLURRY MENTION FROM WED NIGHT INTO MID MORNING THURSDAY.
WILL SEE A PATTERN CHANGE STARTING ON FRIDAY AS UPPER LEVEL LOW
PRESSURE OVER EASTERN CANADA THURSDAY LIFTS MORE NORTHEAST TOWARDS
WESTERN GREENLAND FRI-SAT. THIS TRANSITIONS OUR FLOW ALOFT FROM
STRONG NORTHWESTERLY TO A WEAKER NORTHWESTERLY BY SATURDAY...AND
EVENTUALLY QUASI-ZONAL BY SUNDAY. WILL MAINTAIN DRY CONDITIONS AND
A SLOW WARM-UP UNDER THIS FLOW PATTERN THROUGH SAT NIGHT. AS THIS
CHANGE IS OCCURRING...STRONG UPPER LOW OVER ALASKA ON THURSDAY
WILL MOVE SLOWLY SOUTHEAST ALONG THE CANADIAN PACIFIC SHORE
SATURDAY NIGHT INTO SUNDAY...THEN INTO THE PACIFIC NORTHWEST BY
EARLY MONDAY. LEAD EMBEDDED IMPULSES WITHIN THIS FEATURE MAY BRING
PRECIPITATION TO THE DAKOTAS AS EARLY AS SUNDAY DAYTIME (00Z
ECMWF)...OR MAY HOLD OFF UNTIL MONDAY (00Z GFS). THUS MODELS STILL
SHOWING LOTS OF UNCERTAINTY ONLY 4-5 DAYS OUT. WAA AHEAD OF THIS
SYSTEM WOULD SUPPORT A VARIETY OF PRECIPITATION TYPES...DEPENDING
WHETHER WE SEE PRECIP AT NIGHT OR IN THE DAYTIME.
UNCERTAINTY COMPOUNDS AS WE GO FORWARD INTO THE EARLY TO MIDDLE
PORTIONS OF NEXT WEEK AS THE UPPER LOW EVOLVES. THE LATEST GFS
PRODUCES SPLIT FLOW DEVELOPING MONDAY NIGHT INTO TUESDAY...WITH
THE BULK OF ASSOCIATED PRECIPITATION OFF TO OUR NORTH IN CANADA.
THE LATEST 00Z ECMWF (MUCH SLOWER THAN THE 12Z ECMWF) MAINTAINS A
CLOSED SYSTEM AND DOES IMPACT WEST AND NORTH CENTRAL PARTS OF THE
STATE WITH WINTER WEATHER. ALL SOLUTIONS BRING IN MUCH COLDER AIR
SOMETIME TUESDAY OR WEDNESDAY. WILL CONTINUE TO MONITOR IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1241 PM CST WED NOV 27 2013
MVFR STRATUS WILL CONTINUE TO DROP SOUTH FROM CANADA...IMPACTING
TAF SITES FROM 19Z AT KISN TO 01Z THIS EVENING AT KJMS. A FEW
FLURRIES MAY ACCOMPANY THE LOW CLOUDS...WITH POSSIBLE
CONTRIBUTIONS FROM LAKE ENHANCED MOISTURE. W/SW WINDS WILL BECOME
NORTHWEST THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...JV
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1040 AM CST WED NOV 27 2013
.UPDATE...
ISSUED AT 1004 AM CST WED NOV 27 2013
LOW CLOUDS CONTINUE TO MAKE QUICK PROGRESS AND WILL SPREAD INTO
NORTHERN NORTH DAKOTA BY MIDDAY. ISOLATED FLURRIES STILL EXPECTED
WITH STRATUS DECK. ALSO RAISED TEMPERATURES SLIGHTLY IN THE
SOUTHWEST AFTER FAST WARMING THROUGH LATE MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST WED NOV 27 2013
CURRENTLY...SURFACE LOW PRESSURE WAS CENTERED OVER SOUTHWESTERN
SASKATCHEWAN/NORTH CENTRAL MONTANA. SOUTH WINDS AHEAD OF THE SYSTEM
HAD DEVELOPED OVER WESTERN AND CENTRAL NORTH DAKOTA DURING THE
EVENING HOURS...AND STRONG WARM ADVECTION CONTINUED OVER THE WESTERN
HALF OF NORTH DAKOTA AHEAD OF THIS SYSTEM. REGARDING
TEMPERATURES...READINGS HAD RISEN INTO THE LOWER 20S ACROSS FAR
WESTERN NORTH DAKOTA...AND INTO THE TEENS OVER WESTERN PORTIONS OF
CENTRAL NORTH DAKOTA. THIS TREND OF RISING TEMPERATURES SHOULD
CONTINUE EASTWARD THROUGH SUNRISE.
ALONG WITH THE WARM ADVECTION...IT APPEARS THAT THE RUC MODEL HAS A
VERY GOOD HANDLE ON H850 TO H700 LIFTING OCCURRING OVER SOUTHEASTERN
SASKATCHEWAN/SOUTHWEST MANITOBA/NORTHERN NORTH DAKOTA. THIS MODEL
WAS DEPICTING LIGHT PRECIPITATION OVER THIS SAME AREA AROUND
MIDNIGHT...AND IT CONTINUES/ADVECTS IT EASTWARD DURING THE REST OF
THE NIGHTTIME HOURS. CURRENT RADAR LOOPS VALIDATING AT LEAST SOME
ENHANCED CLOUDS AND/OR LIFT OCCURRING...SO WILL KEEP A MENTION OF
FLURRIES FOR THIS TIME PERIOD OVER NORTH CENTRAL TO THE JAMESTOWN
AREA THROUGH SUNRISE.
THE 06Z NAM AS WELL AS THE 00Z ECMWF AND GFS MODELS ARE NOW
DEPICTING LIGHT PRECIPITATION OVER NORTHEASTERN NORTH DAKOTA FROM 6
AM TO NOON TIME FRAME. THIS APPEARS TO BE THE RESULT OF BOTH WARM
ADVECTION LIFTING AT H850/H700 AS WELL AS REINFORCEMENT FROM AN
UPPER LEVEL SHORTWAVE MOVING SOUTHEAST OUT OF MANITOBA. ADDED A
MENTION OF CHANCE OF LIGHT SNOW THIS MORNING IN THE BOTTINEAU/TURTLE
MOUNTAIN/HARVEY AREA.
CONTINUED WARM ADVECTION THROUGH THE DAY UNTIL A COLD FRONT DIVES
SOUTHEAST OUT OF SASKATCHEWAN THIS AFTERNOON SWEEPING ACROSS THE
STATE AND REACHING THE JAMES RIVER VALLEY LATE AFTERNOON/EVENING.
SOUTH WINDS AHEAD OF THE FRONT WILL BECOME NORTHWEST AT AROUND 15
MPH. EXPECTING HIGH TEMPERATURES TO REACH INTO THE 20S OVER
NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THROUGH THE JAMES RIVER
VALLEY...WITH TEMPERATURES IN THE 30S MAINLY SOUTH AND WEST OF THE
MISSOURI RIVER. THE FAR SOUTHWEST MAY SEE TEMPERATURES REACH INTO
THE LOWER 40S.
THE COLD FRONT WILL BE FOLLOWED BY ANOTHER ARCTIC HIGH PRESSURE
SYSTEM...AND EXPECTING LOWS TONIGHT FROM THE SINGLE DIGITS NORTH TO
LOWER TEENS SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 350 AM CST WED NOV 27 2013
FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BY MAINLY DRY
CONDITIONS THROUGH SATURDAY NIGHT...FOLLOWED BY A POSSIBLE VERY
ACTIVE WEATHER PERIOD SOMETIME FROM SUNDAY INTO THE MIDDLE
PORTIONS OF NEXT WEEK.
THE EXTENDED PERIOD BEGINS THURSDAY MORNING WITH STRONG NORTHWEST
FLOW ALOFT OVER THE NORTHERN PLAINS AND A SFC RIDGE OF HIGH
PRESSURE EXTENDING FROM NORTH OF MANITOBA SOUTH THROUGH THE
DAKOTAS. BOTH THE 00Z NAM/GFS CONTINUE TO INDICATE LOW STRATUS
FROM WEDNESDAY NIGHT PERSISTING INTO THURSDAY MORNING ACROSS MUCH
OF WEST AND CENTRAL NORTH DAKOTA WITH THE SFC RIDGE. COUPLED WITH
SUBTLE MID/UPPER LEVEL SUPPORT...OPTED TO CONTINUE THE ISOLATED
FLURRY MENTION FROM WED NIGHT INTO MID MORNING THURSDAY.
WILL SEE A PATTERN CHANGE STARTING ON FRIDAY AS UPPER LEVEL LOW
PRESSURE OVER EASTERN CANADA THURSDAY LIFTS MORE NORTHEAST TOWARDS
WESTERN GREENLAND FRI-SAT. THIS TRANSITIONS OUR FLOW ALOFT FROM
STRONG NORTHWESTERLY TO A WEAKER NORTHWESTERLY BY SATURDAY...AND
EVENTUALLY QUASI-ZONAL BY SUNDAY. WILL MAINTAIN DRY CONDITIONS AND
A SLOW WARM-UP UNDER THIS FLOW PATTERN THROUGH SAT NIGHT. AS THIS
CHANGE IS OCCURRING...STRONG UPPER LOW OVER ALASKA ON THURSDAY
WILL MOVE SLOWLY SOUTHEAST ALONG THE CANADIAN PACIFIC SHORE
SATURDAY NIGHT INTO SUNDAY...THEN INTO THE PACIFIC NORTHWEST BY
EARLY MONDAY. LEAD EMBEDDED IMPULSES WITHIN THIS FEATURE MAY BRING
PRECIPITATION TO THE DAKOTAS AS EARLY AS SUNDAY DAYTIME (00Z
ECMWF)...OR MAY HOLD OFF UNTIL MONDAY (00Z GFS). THUS MODELS STILL
SHOWING LOTS OF UNCERTAINTY ONLY 4-5 DAYS OUT. WAA AHEAD OF THIS
SYSTEM WOULD SUPPORT A VARIETY OF PRECIPITATION TYPES...DEPENDING
WHETHER WE SEE PRECIP AT NIGHT OR IN THE DAYTIME.
UNCERTAINTY COMPOUNDS AS WE GO FORWARD INTO THE EARLY TO MIDDLE
PORTIONS OF NEXT WEEK AS THE UPPER LOW EVOLVES. THE LATEST GFS
PRODUCES SPLIT FLOW DEVELOPING MONDAY NIGHT INTO TUESDAY...WITH
THE BULK OF ASSOCIATED PRECIPITATION OFF TO OUR NORTH IN CANADA.
THE LATEST 00Z ECMWF (MUCH SLOWER THAN THE 12Z ECMWF) MAINTAINS A
CLOSED SYSTEM AND DOES IMPACT WEST AND NORTH CENTRAL PARTS OF THE
STATE WITH WINTER WEATHER. ALL SOLUTIONS BRING IN MUCH COLDER AIR
SOMETIME TUESDAY OR WEDNESDAY. WILL CONTINUE TO MONITOR IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1004 AM CST WED NOV 27 2013
MVFR STRATUS WILL CONTINUE TO PUSH SOUTH...INITIALLY IMPACTING
KISN AROUND 18Z...AND FINALLY KJMS AROUND 23Z. A FEW FLURRIES WILL
ACCOMPANY THE LOW CLOUDS...MAINLY AT KMOT. W/SW WINDS WILL BECOME
NORTHWEST THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...JV
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
632 AM CST WED NOV 27 2013
.UPDATE...
ISSUED AT 632 AM CST WED NOV 27 2013
WITH STRATUS MOVING IN THIS AFTERNOON...ADDED ISOLD FLURRIES
21-00Z IN ADDITION TO WHAT WAS IN THE FORECAST AFTER 00Z.
OTHERWISE...INHERITED FORECAST REMAINS VALID...THUS CHANGES WERE
ONLY TO INCORPORATE LATEST OBS AND NEAR TERM MODEL GUIDANCE. SEE
SHORT TERM DISCUSSION BELOW FOR DETAILS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST WED NOV 27 2013
CURRENTLY...SURFACE LOW PRESSURE WAS CENTERED OVER SOUTHWESTERN
SASKATCHEWAN/NORTH CENTRAL MONTANA. SOUTH WINDS AHEAD OF THE SYSTEM
HAD DEVELOPED OVER WESTERN AND CENTRAL NORTH DAKOTA DURING THE
EVENING HOURS...AND STRONG WARM ADVECTION CONTINUED OVER THE WESTERN
HALF OF NORTH DAKOTA AHEAD OF THIS SYSTEM. REGARDING
TEMPERATURES...READINGS HAD RISEN INTO THE LOWER 20S ACROSS FAR
WESTERN NORTH DAKOTA...AND INTO THE TEENS OVER WESTERN PORTIONS OF
CENTRAL NORTH DAKOTA. THIS TREND OF RISING TEMPERATURES SHOULD
CONTINUE EASTWARD THROUGH SUNRISE.
ALONG WITH THE WARM ADVECTION...IT APPEARS THAT THE RUC MODEL HAS A
VERY GOOD HANDLE ON H850 TO H700 LIFTING OCCURRING OVER SOUTHEASTERN
SASKATCHEWAN/SOUTHWEST MANITOBA/NORTHERN NORTH DAKOTA. THIS MODEL
WAS DEPICTING LIGHT PRECIPITATION OVER THIS SAME AREA AROUND
MIDNIGHT...AND IT CONTINUES/ADVECTS IT EASTWARD DURING THE REST OF
THE NIGHTTIME HOURS. CURRENT RADAR LOOPS VALIDATING AT LEAST SOME
ENHANCED CLOUDS AND/OR LIFT OCCURRING...SO WILL KEEP A MENTION OF
FLURRIES FOR THIS TIME PERIOD OVER NORTH CENTRAL TO THE JAMESTOWN
AREA THROUGH SUNRISE.
THE 06Z NAM AS WELL AS THE 00Z ECMWF AND GFS MODELS ARE NOW
DEPICTING LIGHT PRECIPITATION OVER NORTHEASTERN NORTH DAKOTA FROM 6
AM TO NOON TIME FRAME. THIS APPEARS TO BE THE RESULT OF BOTH WARM
ADVECTION LIFTING AT H850/H700 AS WELL AS REINFORCEMENT FROM AN
UPPER LEVEL SHORTWAVE MOVING SOUTHEAST OUT OF MANITOBA. ADDED A
MENTION OF CHANCE OF LIGHT SNOW THIS MORNING IN THE BOTTINEAU/TURTLE
MOUNTAIN/HARVEY AREA.
CONTINUED WARM ADVECTION THROUGH THE DAY UNTIL A COLD FRONT DIVES
SOUTHEAST OUT OF SASKATCHEWAN THIS AFTERNOON SWEEPING ACROSS THE
STATE AND REACHING THE JAMES RIVER VALLEY LATE AFTERNOON/EVENING.
SOUTH WINDS AHEAD OF THE FRONT WILL BECOME NORTHWEST AT AROUND 15
MPH. EXPECTING HIGH TEMPERATURES TO REACH INTO THE 20S OVER
NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THROUGH THE JAMES RIVER
VALLEY...WITH TEMPERATURES IN THE 30S MAINLY SOUTH AND WEST OF THE
MISSOURI RIVER. THE FAR SOUTHWEST MAY SEE TEMPERATURES REACH INTO
THE LOWER 40S.
THE COLD FRONT WILL BE FOLLOWED BY ANOTHER ARCTIC HIGH PRESSURE
SYSTEM...AND EXPECTING LOWS TONIGHT FROM THE SINGLE DIGITS NORTH TO
LOWER TEENS SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 350 AM CST WED NOV 27 2013
FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BY MAINLY DRY
CONDITIONS THROUGH SATURDAY NIGHT...FOLLOWED BY A POSSIBLE VERY
ACTIVE WEATHER PERIOD SOMETIME FROM SUNDAY INTO THE MIDDLE
PORTIONS OF NEXT WEEK.
THE EXTENDED PERIOD BEGINS THURSDAY MORNING WITH STRONG NORTHWEST
FLOW ALOFT OVER THE NORTHERN PLAINS AND A SFC RIDGE OF HIGH
PRESSURE EXTENDING FROM NORTH OF MANITOBA SOUTH THROUGH THE
DAKOTAS. BOTH THE 00Z NAM/GFS CONTINUE TO INDICATE LOW STRATUS
FROM WEDNESDAY NIGHT PERSISTING INTO THURSDAY MORNING ACROSS MUCH
OF WEST AND CENTRAL NORTH DAKOTA WITH THE SFC RIDGE. COUPLED WITH
SUBTLE MID/UPPER LEVEL SUPPORT...OPTED TO CONTINUE THE ISOLATED
FLURRY MENTION FROM WED NIGHT INTO MID MORNING THURSDAY.
WILL SEE A PATTERN CHANGE STARTING ON FRIDAY AS UPPER LEVEL LOW
PRESSURE OVER EASTERN CANADA THURSDAY LIFTS MORE NORTHEAST TOWARDS
WESTERN GREENLAND FRI-SAT. THIS TRANSITIONS OUR FLOW ALOFT FROM
STRONG NORTHWESTERLY TO A WEAKER NORTHWESTERLY BY SATURDAY...AND
EVENTUALLY QUASI-ZONAL BY SUNDAY. WILL MAINTAIN DRY CONDITIONS AND
A SLOW WARM-UP UNDER THIS FLOW PATTERN THROUGH SAT NIGHT. AS THIS
CHANGE IS OCCURRING...STRONG UPPER LOW OVER ALASKA ON THURSDAY
WILL MOVE SLOWLY SOUTHEAST ALONG THE CANADIAN PACIFIC SHORE
SATURDAY NIGHT INTO SUNDAY...THEN INTO THE PACIFIC NORTHWEST BY
EARLY MONDAY. LEAD EMBEDDED IMPULSES WITHIN THIS FEATURE MAY BRING
PRECIPITATION TO THE DAKOTAS AS EARLY AS SUNDAY DAYTIME (00Z
ECMWF)...OR MAY HOLD OFF UNTIL MONDAY (00Z GFS). THUS MODELS STILL
SHOWING LOTS OF UNCERTAINTY ONLY 4-5 DAYS OUT. WAA AHEAD OF THIS
SYSTEM WOULD SUPPORT A VARIETY OF PRECIPITATION TYPES...DEPENDING
WHETHER WE SEE PRECIP AT NIGHT OR IN THE DAYTIME.
UNCERTAINTY COMPOUNDS AS WE GO FORWARD INTO THE EARLY TO MIDDLE
PORTIONS OF NEXT WEEK AS THE UPPER LOW EVOLVES. THE LATEST GFS
PRODUCES SPLIT FLOW DEVELOPING MONDAY NIGHT INTO TUESDAY...WITH
THE BULK OF ASSOCIATED PRECIPITATION OFF TO OUR NORTH IN CANADA.
THE LATEST 00Z ECMWF (MUCH SLOWER THAN THE 12Z ECMWF) MAINTAINS A
CLOSED SYSTEM AND DOES IMPACT WEST AND NORTH CENTRAL PARTS OF THE
STATE WITH WINTER WEATHER. ALL SOLUTIONS BRING IN MUCH COLDER AIR
SOMETIME TUESDAY OR WEDNESDAY. WILL CONTINUE TO MONITOR IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 632 AM CST WED NOV 27 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
THIS MORNING. A WARM FRONT WILL MOVE EAST ACROSS THE STATE TODAY.
THIS WILL BE FOLLOWED BY A COLD FRONT THAT WILL MOVE SOUTHEAST
ACROSS THE STATE. SOUTH WINDS WITH SCT-BKN MID AND HIGH CLOUDS
AHEAD OF THE WARM FRONT...FOLLOWED BY SOUTHWEST WINDS FOR A BRIEF
PERIOD...THEN A NORTHWESTERLY WIND SHIFT WITH THE COLD FRONT. MVFR
CIGS NORTH AND WEST (KISN-KMOT-KDIK) AFTER 18Z AND REACHING KBIS
WEDNESDAY MID-AFTERNOON. LOW CONFIDENCE IN TIMING OF MVFR CIGS
REACHING TAF SITES AFTER WINDS SHIFT TO NORTHWEST. WIND SHIFT AND
MVFR CIGS NOT EXPECTED TO REACH KJMS UNTIL LATE AFTERNOON OR
EVENING. MVFR CIGS EXPECTED TO PERSIST BEYOND THE END OF THE TAF
PERIOD (12Z THU).
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
350 AM CST WED NOV 27 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST WED NOV 27 2013
CURRENTLY...SURFACE LOW PRESSURE WAS CENTERED OVER SOUTHWESTERN
SASKATCHEWAN/NORTH CENTRAL MONTANA. SOUTH WINDS AHEAD OF THE SYSTEM
HAD DEVELOPED OVER WESTERN AND CENTRAL NORTH DAKOTA DURING THE
EVENING HOURS...AND STRONG WARM ADVECTION CONTINUED OVER THE WESTERN
HALF OF NORTH DAKOTA AHEAD OF THIS SYSTEM. REGARDING
TEMPERATURES...READINGS HAD RISEN INTO THE LOWER 20S ACROSS FAR
WESTERN NORTH DAKOTA...AND INTO THE TEENS OVER WESTERN PORTIONS OF
CENTRAL NORTH DAKOTA. THIS TREND OF RISING TEMPERATURES SHOULD
CONTINUE EASTWARD THROUGH SUNRISE.
ALONG WITH THE WARM ADVECTION...IT APPEARS THAT THE RUC MODEL HAS A
VERY GOOD HANDLE ON H850 TO H700 LIFTING OCCURRING OVER SOUTHEASTERN
SASKATCHEWAN/SOUTHWEST MANITOBA/NORTHERN NORTH DAKOTA. THIS MODEL
WAS DEPICTING LIGHT PRECIPITATION OVER THIS SAME AREA AROUND
MIDNIGHT...AND IT CONTINUES/ADVECTS IT EASTWARD DURING THE REST OF
THE NIGHTTIME HOURS. CURRENT RADAR LOOPS VALIDATING AT LEAST SOME
ENHANCED CLOUDS AND/OR LIFT OCCURRING...SO WILL KEEP A MENTION OF
FLURRIES FOR THIS TIME PERIOD OVER NORTH CENTRAL TO THE JAMESTOWN
AREA THROUGH SUNRISE.
THE 06Z NAM AS WELL AS THE 00Z ECMWF AND GFS MODELS ARE NOW
DEPICTING LIGHT PRECIPITATION OVER NORTHEASTERN NORTH DAKOTA FROM 6
AM TO NOON TIME FRAME. THIS APPEARS TO BE THE RESULT OF BOTH WARM
ADVECTION LIFTING AT H850/H700 AS WELL AS REINFORCEMENT FROM AN
UPPER LEVEL SHORTWAVE MOVING SOUTHEAST OUT OF MANITOBA. ADDED A
MENTION OF CHANCE OF LIGHT SNOW THIS MORNING IN THE BOTTINEAU/TURTLE
MOUNTAIN/HARVEY AREA.
CONTINUED WARM ADVECTION THROUGH THE DAY UNTIL A COLD FRONT DIVES
SOUTHEAST OUT OF SASKATCHEWAN THIS AFTERNOON SWEEPING ACROSS THE
STATE AND REACHING THE JAMES RIVER VALLEY LATE AFTERNOON/EVENING.
SOUTH WINDS AHEAD OF THE FRONT WILL BECOME NORTHWEST AT AROUND 15
MPH. EXPECTING HIGH TEMPERATURES TO REACH INTO THE 20S OVER
NORTHWEST AND NORTH CENTRAL NORTH DAKOTA THROUGH THE JAMES RIVER
VALLEY...WITH TEMPERATURES IN THE 30S MAINLY SOUTH AND WEST OF THE
MISSOURI RIVER. THE FAR SOUTHWEST MAY SEE TEMPERATURES REACH INTO
THE LOWER 40S.
THE COLD FRONT WILL BE FOLLOWED BY ANOTHER ARCTIC HIGH PRESSURE
SYSTEM...AND EXPECTING LOWS TONIGHT FROM THE SINGLE DIGITS NORTH TO
LOWER TEENS SOUTH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 350 AM CST WED NOV 27 2013
FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BY MAINLY DRY
CONDITIONS THROUGH SATURDAY NIGHT...FOLLOWED BY A POSSIBLE VERY
ACTIVE WEATHER PERIOD SOMETIME FROM SUNDAY INTO THE MIDDLE
PORTIONS OF NEXT WEEK.
THE EXTENDED PERIOD BEGINS THURSDAY MORNING WITH STRONG NORTHWEST
FLOW ALOFT OVER THE NORTHERN PLAINS AND A SFC RIDGE OF HIGH
PRESSURE EXTENDING FROM NORTH OF MANITOBA SOUTH THROUGH THE
DAKOTAS. BOTH THE 00Z NAM/GFS CONTINUE TO INDICATE LOW STRATUS
FROM WEDNESDAY NIGHT PERSISTING INTO THURSDAY MORNING ACROSS MUCH
OF WEST AND CENTRAL NORTH DAKOTA WITH THE SFC RIDGE. COUPLED WITH
SUBTLE MID/UPPER LEVEL SUPPORT...OPTED TO CONTINUE THE ISOLATED
FLURRY MENTION FROM WED NIGHT INTO MID MORNING THURSDAY.
WILL SEE A PATTERN CHANGE STARTING ON FRIDAY AS UPPER LEVEL LOW
PRESSURE OVER EASTERN CANADA THURSDAY LIFTS MORE NORTHEAST TOWARDS
WESTERN GREENLAND FRI-SAT. THIS TRANSITIONS OUR FLOW ALOFT FROM
STRONG NORTHWESTERLY TO A WEAKER NORTHWESTERLY BY SATURDAY...AND
EVENTUALLY QUASI-ZONAL BY SUNDAY. WILL MAINTAIN DRY CONDITIONS AND
A SLOW WARM-UP UNDER THIS FLOW PATTERN THROUGH SAT NIGHT. AS THIS
CHANGE IS OCCURRING...STRONG UPPER LOW OVER ALASKA ON THURSDAY
WILL MOVE SLOWLY SOUTHEAST ALONG THE CANADIAN PACIFIC SHORE
SATURDAY NIGHT INTO SUNDAY...THEN INTO THE PACIFIC NORTHWEST BY
EARLY MONDAY. LEAD EMBEDDED IMPULSES WITHIN THIS FEATURE MAY BRING
PRECIPITATION TO THE DAKOTAS AS EARLY AS SUNDAY DAYTIME (00Z
ECMWF)...OR MAY HOLD OFF UNTIL MONDAY (00Z GFS). THUS MODELS STILL
SHOWING LOTS OF UNCERTAINTY ONLY 4-5 DAYS OUT. WAA AHEAD OF THIS
SYSTEM WOULD SUPPORT A VARIETY OF PRECIPITATION TYPES...DEPENDING
WHETHER WE SEE PRECIP AT NIGHT OR IN THE DAYTIME.
UNCERTAINTY COMPOUNDS AS WE GO FORWARD INTO THE EARLY TO MIDDLE
PORTIONS OF NEXT WEEK AS THE UPPER LOW EVOLVES. THE LATEST GFS
PRODUCES SPLIT FLOW DEVELOPING MONDAY NIGHT INTO TUESDAY...WITH
THE BULK OF ASSOCIATED PRECIPITATION OFF TO OUR NORTH IN CANADA.
THE LATEST 00Z ECMWF (MUCH SLOWER THAN THE 12Z ECMWF) MAINTAINS A
CLOSED SYSTEM AND DOES IMPACT WEST AND NORTH CENTRAL PARTS OF THE
STATE WITH WINTER WEATHER. ALL SOLUTIONS BRING IN MUCH COLDER AIR
SOMETIME TUESDAY OR WEDNESDAY. WILL CONTINUE TO MONITOR IN THE
COMING DAYS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1244 AM CST WED NOV 27 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT. A PACIFIC FRONT WILL PUSH THROUGH THE STATE WEDNESDAY
GENERATING A NORTHWESTERLY WIND SHIFT AND MVFR CIGS NORTH AND WEST
(KISN-KMOT-KDIK) AFTER 18Z AND REACHING KBIS WEDNESDAY
MID-AFTERNOON. LOW CONFIDENCE IN TIMING OF MVFR CIGS REACHING TAF
SITES AFTER WINDS SHIFT TO NORTHWEST. WIND SHIFT AND MVFR CIGS NOT
EXPECTED TO REACH KJMS UNTIL LATE AFTERNOON OR EVENING. MVFR CIGS
EXPECTED TO PERSIST BEYOND THE END OF THE TAF PERIOD (06Z THU).
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 AM CST WED NOV 27 2013
.UPDATE...
ISSUED AT 1244 AM CST WED NOV 27 2013
SURFACE LOW PRESSURE WAS CENTERED OVER SOUTHWESTERN
SASKATCHEWAN/NORTH CENTRAL MONTANA. SOUTH WINDS AHEAD OF THE SYSTEM
HAD DEVELOPED OVER WESTERN AND CENTRAL NORTH DAKOTA DURING THE
EVENING HOURS. STRONG WARM ADVECTION OCCURRING OVER THE WESTERN HALF
OF THE STATE AHEAD OF THIS SYSTEM. REGARDING TEMPERATURES...READINGS
HAVE RISEN INTO THE LOWER 20S ALREADY ACROSS FAR WESTERN NORTH
DAKOTA...AND INTO THE TEENS OVER WESTERN PORTIONS OF CENTRAL NORTH
DAKOTA. THIS TREND OF RISING TEMPERATURES SHOULD CONTINUE EASTWARD
DURING THE OVERNIGHT HOURS...THUS STEADY OR RISING TEMPERATURES IS
FORECAST FOR THE REST OF TONIGHT.
ALONG WITH THE WARM ADVECTION...IT APPEARS THAT THE RUC MODEL HAS A
VERY GOOD HANDLE ON H850 TO H700 LIFTING OCCURRING OVER SOUTHEASTERN
SASKATCHEWAN/SOUTHWEST MANITOBA/NORTHERN NORTH DAKOTA. THIS MODEL
WAS DEPICTING LIGHT PRECIPITATION OVER THIS SAME AREA AROUND
MIDNIGHT...AND IT CONTINUES/ADVECTS IT EASTWARD DURING THE REST OF
THE NIGHTTIME HOURS. CURRENT RADAR LOOPS VALIDATING AT LEAST SOME
ENHANCED CLOUDS AND/OR LIFT OCCURRING...SO ADDED A MENTION OF
FLURRIES FOR THIS TIME PERIOD OVER NORTH CENTRAL TO THE JAMESTOWN
AREA FOR THE REST OF TONIGHT.
UPDATE ISSUED AT 939 PM CST TUE NOV 26 2013
TEMPERATURES HAVE RADIATED TO THE LOW SINGLE DIGITS ALONG THE CENTER
OF THE SURFACE HIGH PRESSURE RIDGE AXIS EXTENDING FROM THE TURTLE
MOUNTAINS INTO THE JAMES RIVER VALLEY. AS OF 9 PM CST...HARVEY
REPORTED A TEMPERATURE OF ONE DEGREE ABOVE ZERO. GIVEN THE CURRENT
OBS/TRENDS...ADJUSTED OVERNIGHT LOWS DOWN A CATEGORY...ESPECIALLY
OVER AREAS EAST OF HIGHWAY 83 PROXIMATE TO THE SURFACE RIDGE AXIS.
OTHERWISE...THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE
UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 644 PM CST TUE NOV 26 2013
SURFACE HIGH PRESSURE HAS CRESTED ACROSS WESTERN AND CENTRAL NORTH
DAKOTA THIS EVENING AND WILL CONTINUE TO PUSH EAST TONIGHT. AS A
RESULT...RETURN FLOW WILL DEVELOP AS LOW PRESSURE MOVES INTO
SOUTHERN SASKATCHEWAN. TEMPERATURES SHOULD CONTINUE TO DROP IN
AREAS OF LIGHT WIND THIS EVENING...THEN HOLD STEADY OR EVEN
INCREASE IN SOME SPOTS AS SOUTHERLY FLOW DEVELOPS AFTER MIDNIGHT.
THE CURRENT FORECAST CAPTURES THIS SCENARIO SO ONLY MADE MINOR
ADJUSTMENTS TO THE SENSIBLE WEATHER GRIDS FOR THIS UPDATE. THE
UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 240 PM CST TUE NOV 26 2013
SURFACE HIGH PRESSURE WILL DRIFT EAST OVERNIGHT AS WEAK RETURN
FLOW BECOMES ESTABLISHED IN WESTERN NORTH DAKOTA. EARLY MORNING
LOWS SHOULD BE HELD UP IN THE TEENS SOUTHWEST...BUT DROP INTO THE
SINGLE DIGITS ELSEWHERE. A FRONTAL BOUNDARY AND ASSOCIATED WEAK 500MB
WAVE WILL SKIRT NORTHEAST NORTH DAKOTA WEDNESDAY MORNING. HAVE
KEPT SLIGHT CHANCE POPS IN PLACE FOR THE TURTLE MOUNTAINS AREA
DURING THE MORNING HOURS. MILDER PACIFIC AIR WILL SPREAD INTO
WESTERN AND CENTRAL PORTIONS OF THE FORECAST AREA ON WEDNESDAY AND
BOOST AFTERNOON TEMPERATURES INTO THE 30S SOUTH AND EAST OF THE
MISSOURI RIVER. READINGS IN THE 20S ARE FORECAST NORTH AND EAST OF
THE RIVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 240 PM CST TUE NOV 26 2013
A PROGRESSIVE FLOW REMAINS ON TRACK THROUGH THE EXTENDED WITH NO
ORGANIZED PRECIPITATION AREAS UNTIL LATE IN THE PERIOD...WITH THOSE
DETAILS REMAINING UNCERTAIN IN REGARDS TO SNOW PLACEMENT AND DURATION.
HOWEVER THE POTENTIAL FOR UNSETTLED WEATHER STILL LOOKS TO OCCUR IN
THE SUNDAY THROUGH TUESDAY TIME FRAME...WITH MUCH COLDER AIR BY
MIDWEEK NEXT WEEK.
WEDNESDAY NIGHT THROUGH SATURDAY...AN H85 COLD POCKET OF AIR AND
ASSOCIATED SWATH OF STRATUS IS FORECAST TO INFILTRATE NORTHERN NORTH
DAKOTA WEDNESDAY EVENING AND FILTER SOUTH WEDNESDAY NIGHT. THERE
COULD BE SOME FLURRIES GENERATED WITHIN THE STRATUS LAYER WITH
FORECAST 925-850MB LAPSE RATES BETWEEN 6C AND 7C/KM WEDNESDAY NIGHT
AND THUS HAVE INCLUDED ISOLATED FLURRIES IN THE GRIDS. OVERALL HAVE
CONTINUED WITH THE PREVIOUS FORECAST THINKING WITH HIGHER SKY GRID
NUMBERS WEDNESDAY NIGHT AS THE 12Z NAM/GFS 925MB RH FIELD ALSO
REMAIN CONSISTENT WITH THIS IDEA. FOR THURSDAY INTO SATURDAY...WEAK
WARM AIR ADVECTION WILL YIELD A SLIGHT WARMUP UNDER DRY CONDITIONS.
HIGH TEMPERATURES THANKSGIVING WILL RANGE FROM 15F TO 25F...WITH
HIGHS RISING TO BETWEEN 25F TO 40F SATURDAY.
SUNDAY THROUGH TUESDAY...STRONG UPPER LOW DROPPING INTO BRITISH
COLUMBIA WITH THE AIRMASS ORIGINALLY ROOTED IN EASTERN RUSSIA. LARGE
POCKET OF H85 TEMPS BETWEEN -25C TO -30C WILL HOVER OVER BRITISH
COLUMBIA AND ALBERTA EARLY NEXT WEEK WITH SUCCESSIVE CHUNKS BREAKING
OFF AND PUSHING TOWARD NORTH DAKOTA LATE IN THE LONG TERM PERIOD.
THIS WILL YIELD MUCH COLDER AIR BY MID TO LATE WEEK. IN TERMS OF
SNOWFALL POTENTIAL...A CHANCE OF SNOW REMAINS IN THE FORECAST
BEGINNING SUNDAY...BUT MORE SO MONDAY AND TUESDAY. THE GFS AND ECMWF
REMAIN AT ODDS WITH A DRY SLOT LOCATION AND HENCE IT IS DIFFICULT TO
HAVE CONFIDENCE ON THE DURATION AND PLACEMENT OF THE SNOW. WILL NOT
MAKE ANY CHANGES TO THE ALLBLEND SOLUTION WHICH BASICALLY HAS A
WIDESPREAD CHANCE OF SNOW MONDAY AND TUESDAY. A SLIGHT CHANCE OF
SNOW CONTINUES FOR SUNDAY...WITH POPS INCREASING THEREAFTER. WILL
CONTINUE TO KEEP THE MENTION GOING IN THE HAZARDOUS WEATHER OUTLOOK
FOR NOW WITH MORE DETAILS TO FOLLOW AS WE GET CLOSER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1244 AM CST WED NOV 27 2013
VFR CONDITIONS WILL PREVAIL OVER WESTERN AND CENTRAL NORTH DAKOTA
TONIGHT. A PACIFIC FRONT WILL PUSH THROUGH THE STATE WEDNESDAY
GENERATING A NORTHWESTERLY WIND SHIFT AND MVFR CIGS NORTH AND WEST
(KISN-KMOT-KDIK) AFTER 18Z AND REACHING KBIS WEDNESDAY
MID-AFTERNOON. LOW CONFIDENCE IN TIMING OF MVFR CIGS REACHING TAF
SITES AFTER WINDS SHIFT TO NORTHWEST. WIND SHIFT AND MVFR CIGS NOT
EXPECTED TO REACH KJMS UNTIL LATE AFTERNOON OR EVENING. MVFR CIGS
EXPECTED TO PERSIST BEYOND THE END OF THE TAF PERIOD (06Z THU).
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1228 PM EST WED NOV 27 2013
.SYNOPSIS...
WINTER STORM CONTINUES TO LIFT TO THE NORTHEAST WITH UPSLOPE SNOW
TONIGHT. HIGH PRESSURE BUILDING IN ON THANKSGIVING DAY AND
LINGERING FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
BULK OF PRECIPITATION STARTING TO SHIFT EASTWARD ACROSS THE CWA
ALONG WITH WEAK BOUNDARY. EXPECTING A TRANSITION TO NORTHWEST
UPSLOPE SNOW SHOWERS LATER THIS MORNING INTO EARLY AFTERNOON.
COULD SEE ANOTHER INCH OR SO ACROSS PARTS OF THE WV LOWLANDS THIS
AFTERNOON/EVENING PARTICULARLY IF A DECENT BAND IS ABLE TO SET UP
ACROSS THE LAKES...WITH STILL SEVERAL INCHES POSSIBLE ACROSS THE
HIGHER TERRAIN COUNTIES...PARTICULARLY ON WEST/NORTHWEST FACING
SLOPES.
FOR NOW...WILL LEAVE HEADLINES AS IS...SOME OF THE LOWLAND
COUNTIES MAY BE ABLE TO BE CANCELLED EARLY...BUT WILL MONITOR FOR
NOW.
PREVIOUS DISCUSSION...
GENERALLY FOLLOWING THE HRRR MODEL IN REGARDS TO THE EVOLUTION OF
THE SYNOPTIC SNOW OVER THE NEXT FEW HOURS INTO THE DAWN HOURS.
DEFORMATION ZONE PROVIDING THE MAIN FORCING OF THE SNOW AT THIS
POINT WILL DRIFT TO THE EAST THROUGH 12Z TODAY...AND CARRY THE
BETTER CHANCES FOR SNOW WITH IT. THERE WAS A PATCH OF DRIER AIR TO
CONTEND WITH A FEW HOURS AGO DURING THE TEMPERATURE TRANSITION TO
BELOW FREEZING VALUES...AND HAVE GOTTEN OFF TO A SLOW START IN TERMS
OF ACCUMULATIONS. THIS SPARKS A FEW CONCERNS ABOUT MEETING THE
PREVIOUSLY FORECASTED AMOUNTS...BUT WILL NOT GIVE UP ON IT JUST YET
AS WE STILL HAVE A FEW HOURS TO GET SOME ACCUMULATIONS OUT OF THIS.
AS THE MAIN SYNOPTIC FORCING FOR THIS EVENT DEPARTS WITH THE
DEFORMATION ZONES PUSHING EAST OF THE MOUNTAINS AND THE 500MB TROUGH
AXIS PASSING LATER TODAY...THE SET UP LOOKS FAIRLY DECENT TO HAVE
CONVECTIVE SNOW FOR THE FIRST PART OF TODAY. LOOKING AT A CROSS
SECTION ORIENTED TO THE MEAN LOW LEVEL WIND SHOWS GOOD SATURATION
INTO THE CRYSTAL GROWTH LAYER...FED BY NORTHWEST FLOW THROUGH THE
LOW LEVELS. FIGURE THE NATURE OF THE SNOW WILL BE OFF AND ON AT THIS
POINT...BUT A QUICK INCH HERE AND THERE WILL BE POSSIBLE THROUGH 18Z
OR 20Z TODAY FOR THE LOWLANDS. THIS POTENTIAL INCREASED IN THE
MOUNTAINS IN THE BETTER UPSLOPE CONDITIONS. AFTER THAT...IT WILL
MAINLY BE A MOUNTAIN EVENT ONLY THAT WILL SLOWLY FADE DURING THE
OVERNIGHT PERIOD.
WINDS WILL BE ON THE INCREASE OUT OF THE NORTHWEST TODAY...WITH
GUSTS UP TO 30KTS AT TIMES. BLOWING SNOW OVER THE HIGHEST RIDGES IS
LIKELY LATER TODAY AND TONIGHT.
DID NOT GET CUTE WITH THE TEMPERATURES TODAY. MAX TEMPERATURES MAY
BE RIGHT AT DAWN AS THE COLDER AIR COMES IN...AND THEN WILL CHILL A
COUPLE DEGREES...BUT COULD MAKE A DEGREE OR TWO RECOVERY THROUGH THE
AFTERNOON TOWARDS THE MORNING VALUES. IN THE END...HIGHS AROUND 30F
WILL RULE FOR MUCH OF THE AREA...AND GETTING COLDER FOR THE
MOUNTAINS BY EVENING. OVERNIGHT...HAVE SNOWSHOE IN THE SINGLE
DIGITS...WITH OTHER LOCATIONS FALLING INTO THE TEENS TO LOWER 20S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
UPPER PATTERN ACROSS THE UNITED STATES RETURNS TO A ZONAL FLOW
THROUGH THE EARLY WEEKEND. THIS WILL KEEP THE COLDEST AIR WITH
CANADIAN HIGH PRESSURE CENTERS UP IN CANADA. EVEN THOUGH UPPER
IMPULSES WILL TRACK EASTWARD THROUGH THE FLOW...THEY WILL BE WEAK.
THIS..IN COMBINATION WITH GULF OF MEXICO MOISTURE BEING CONFINED
ACROSS THE SOUTHERN STATES...WILL BRING DRY CONDITIONS AND A DAY
TIME WARMING TREND. HIGH TEMPERATURES IN THE 30S THURSDAY WILL REACH
WELL INTO THE 40S FRIDAY AND SATURDAY. HOWEVER...THE DRY AIR ALONG
WITH LACK OF CLOUDS...WILL ALLOW FOR COLD NIGHT TIME READINGS WELL
BELOW FREEZING. THUS...LOOK FOR DRY WEATHER AND A LARGE RANGE IN
DIURNAL TEMPERATURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
A RATHER TRANQUIL ZONAL FLOW WITH SOME WEAK TROUGH APPROACHING LATE
IN THE WEEKEND. WILL CONTINUE BRINGING BACK SOME CHANCE POPS FOR
LIGHT RAIN SUNDAY NIGHT AND BECOMING MORE WIDESPREAD MONDAY BEFORE
DIMINISHING POPS MONDAY NIGHT. NOT ANY STRONG FEATURES OR
FRONTS EXPECTED DURING THIS PERIOD.
NO BIG DEVIATIONS FROM HPC MEDIUM RANGE GROUP TEMPERATURES.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
18Z WEDNESDAY THROUGH 18Z THURSDAY...
WIDESPREAD MVFR AND LOCAL IFR CONDITIONS CONTINUE. LIGHT SNOW
SHOWER ACTIVITY ACROSS SOUTHEAST OHIO...EASTERN KY...AND WV
LOWLANDS THROUGH MAINLY 06Z THURSDAY...WITH CONTINUED UPSLOPE SNOW
SHOWERS THROUGH 15Z THURSDAY ACROSS HIGHER TERRAIN COUNTIES.
EXPECT GRADUAL LIFTING/CLEARING TO VFR ACROSS LOWLANDS AFTER 03Z-
06Z AND ACROSS HIGHER TERRAIN COUNTIES AFTER 12Z.
OTHERWISE...GUSTY NORTHWESTERLY WINDS...WITH GUSTS OF UP TO 26 KTS
ACROSS THE LOWLANDS THROUGH 05Z...AND UP TO 40 KTS ACROSS HIGHER
TERRAIN AREAS THROUGH 12Z THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z
THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: VSBY AND CEILING CATEGORIES COULD VARY FROM
FORECAST. LIFTING TO VFR MAY NOT OCCUR AS SOON AS FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY
OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL
INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT
ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH
MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE
MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY L L H H H H H M L L L H
HTS CONSISTENCY L H H H H H H H H H H H
BKW CONSISTENCY M L L L L L L L L L L L
EKN CONSISTENCY L L L L L L L L L L L L
PKB CONSISTENCY H H H H H M M M H H M H
CKB CONSISTENCY L L L H L L L L L L L L
AFTER 18Z THURSDAY...
NO WIDESPREAD IFR EXPECTED AFTER 12Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR WVZ035>037.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ008>011-013>020-024>034-039-040.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR WVZ038-046-
047.
OH...NONE.
KY...NONE.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ003-
004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...SL/26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...SL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
930 AM EST WED NOV 27 2013
.SYNOPSIS...
WINTER STORM SYSTEM LIFTS TO THE NORTHEAST. UPSLOPE SNOW TODAY AND
TONIGHT. HIGH PRESSURE BUILDING IN ON THANKSGIVING DAY AND
LINGERING FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
BULK OF PRECIPITATION STARTING TO SHIFT EASTWARD ACROSS THE CWA
ALONG WITH WEAK BOUNDARY. EXPECTING A TRANSITION TO NORTHWEST
UPSLOPE SNOW SHOWERS LATER THIS MORNING INTO EARLY AFTERNOON.
COULD SEE ANOTHER INCH OR SO ACROSS PARTS OF THE WV LOWLANDS THIS
AFTERNOON/EVENING PARTICULARLY IF A DECENT BAND IS ABLE TO SET UP
ACROSS THE LAKES...WITH STILL SEVERAL INCHES POSSIBLE ACROSS THE
HIGHER TERRAIN COUNTIES...PARTICULARLY ON WEST/NORTHWEST FACING
SLOPES.
FOR NOW...WILL LEAVE HEADLINES AS IS...SOME OF THE LOWLAND
COUNTIES MAY BE ABLE TO BE CANCELLED EARLY...BUT WILL MONITOR FOR
NOW.
PREVIOUS DISCUSSION...
GENERALLY FOLLOWING THE HRRR MODEL IN REGARDS TO THE EVOLUTION OF
THE SYNOPTIC SNOW OVER THE NEXT FEW HOURS INTO THE DAWN HOURS.
DEFORMATION ZONE PROVIDING THE MAIN FORCING OF THE SNOW AT THIS
POINT WILL DRIFT TO THE EAST THROUGH 12Z TODAY...AND CARRY THE
BETTER CHANCES FOR SNOW WITH IT. THERE WAS A PATCH OF DRIER AIR TO
CONTEND WITH A FEW HOURS AGO DURING THE TEMPERATURE TRANSITION TO
BELOW FREEZING VALUES...AND HAVE GOTTEN OFF TO A SLOW START IN TERMS
OF ACCUMULATIONS. THIS SPARKS A FEW CONCERNS ABOUT MEETING THE
PREVIOUSLY FORECASTED AMOUNTS...BUT WILL NOT GIVE UP ON IT JUST YET
AS WE STILL HAVE A FEW HOURS TO GET SOME ACCUMULATIONS OUT OF THIS.
AS THE MAIN SYNOPTIC FORCING FOR THIS EVENT DEPARTS WITH THE
DEFORMATION ZONES PUSHING EAST OF THE MOUNTAINS AND THE 500MB TROUGH
AXIS PASSING LATER TODAY...THE SET UP LOOKS FAIRLY DECENT TO HAVE
CONVECTIVE SNOW FOR THE FIRST PART OF TODAY. LOOKING AT A CROSS
SECTION ORIENTED TO THE MEAN LOW LEVEL WIND SHOWS GOOD SATURATION
INTO THE CRYSTAL GROWTH LAYER...FED BY NORTHWEST FLOW THROUGH THE
LOW LEVELS. FIGURE THE NATURE OF THE SNOW WILL BE OFF AND ON AT THIS
POINT...BUT A QUICK INCH HERE AND THERE WILL BE POSSIBLE THROUGH 18Z
OR 20Z TODAY FOR THE LOWLANDS. THIS POTENTIAL INCREASED IN THE
MOUNTAINS IN THE BETTER UPSLOPE CONDITIONS. AFTER THAT...IT WILL
MAINLY BE A MOUNTAIN EVENT ONLY THAT WILL SLOWLY FADE DURING THE
OVERNIGHT PERIOD.
WINDS WILL BE ON THE INCREASE OUT OF THE NORTHWEST TODAY...WITH
GUSTS UP TO 30KTS AT TIMES. BLOWING SNOW OVER THE HIGHEST RIDGES IS
LIKELY LATER TODAY AND TONIGHT.
DID NOT GET CUTE WITH THE TEMPERATURES TODAY. MAX TEMPERATURES MAY
BE RIGHT AT DAWN AS THE COLDER AIR COMES IN...AND THEN WILL CHILL A
COUPLE DEGREES...BUT COULD MAKE A DEGREE OR TWO RECOVERY THROUGH THE
AFTERNOON TOWARDS THE MORNING VALUES. IN THE END...HIGHS AROUND 30F
WILL RULE FOR MUCH OF THE AREA...AND GETTING COLDER FOR THE
MOUNTAINS BY EVENING. OVERNIGHT...HAVE SNOWSHOE IN THE SINGLE
DIGITS...WITH OTHER LOCATIONS FALLING INTO THE TEENS TO LOWER 20S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
UPPER PATTERN ACROSS THE UNITED STATES RETURNS TO A ZONAL FLOW
THROUGH THE EARLY WEEKEND. THIS WILL KEEP THE COLDEST AIR WITH
CANADIAN HIGH PRESSURE CENTERS UP IN CANADA. EVEN THOUGH UPPER
IMPULSES WILL TRACK EASTWARD THROUGH THE FLOW...THEY WILL BE WEAK.
THIS..IN COMBINATION WITH GULF OF MEXICO MOISTURE BEING CONFINED
ACROSS THE SOUTHERN STATES...WILL BRING DRY CONDITIONS AND A DAY
TIME WARMING TREND. HIGH TEMPERATURES IN THE 30S THURSDAY WILL REACH
WELL INTO THE 40S FRIDAY AND SATURDAY. HOWEVER...THE DRY AIR ALONG
WITH LACK OF CLOUDS...WILL ALLOW FOR COLD NIGHT TIME READINGS WELL
BELOW FREEZING. THUS...LOOK FOR DRY WEATHER AND A LARGE RANGE IN
DIURNAL TEMPERATURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
A RATHER TRANQUIL ZONAL FLOW WITH SOME WEAK TROUGH APPROACHING LATE
IN THE WEEKEND. WILL CONTINUE BRINGING BACK SOME CHANCE POPS FOR
LIGHT RAIN SUNDAY NIGHT AND BECOMING MORE WIDESPREAD MONDAY BEFORE
DIMINISHING POPS MONDAY NIGHT. NOT ANY STRONG FEATURES OR
FRONTS EXPECTED DURING THIS PERIOD.
NO BIG DEVIATIONS FROM HPC MEDIUM RANGE GROUP TEMPERATURES.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
IFR FOR TERMINALS SOUTH AND EAST OF THE OHIO RIVER...SO EXPECT PKB
TO COME UP TO MVFR IN THE NEXT COUPLE OF HOURS FOR A SHORT PERIOD
OF TIME. HTS IS ALREADY THERE. AS THE BAND OF SNOW OVER THE WEST
VIRGINIA LOWLANDS SLOWLY RETREATS TO THE EAST...COULD GET SOME
BRIEF MVFR AND IFR IN THE TRANSITION TO UPSLOPE SNOW IN NORTHWEST
FLOW. WILL BE IN AND OUT OF SNOW SHOWERS FOR THE BULK OF THE
DAY...WITH MORE PERSISTENT SNOW FOR CKB...EKN..AND BKW.
OBSERVATIONS ARE EXPECTED TO BOUNCE...SO TEMPO GROUPS ARE THE TICKET
TODAY FOR THE OSCILLATING CONDITIONS.
WINDS TURN NORTHWESTERLY THIS MORNING...AND WILL INCREASE THROUGH
THE DAY. BY AFTERNOON HOURS...GUSTS 25-30KTS ARE NOT OUT OF THE
QUESTION...AND MAY SEE 35KTS OVER THE HIGHEST RIDGES. WINDS FALL
BACK DOWN TO THE 10-15KTS BY 12Z THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: VISIBILITY RESTRICTIONS COULD VARY WITH SNOW.
CEILINGS WILL DROP SLIGHTLY IN HEAVIER SNOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EST 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
CRW CONSISTENCY M H L L L L L L M L L L
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY L L L L L L L L L L L L
EKN CONSISTENCY M M M L L L L L L L L L
PKB CONSISTENCY L H L L L H M L L L L L
CKB CONSISTENCY H H H L L L L L L L L L
AFTER 12Z THURSDAY...
NO WIDESPREAD IFR EXPECTED AFTER 12Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR WVZ035>037.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ008>011-013>020-024>034-039-040.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR WVZ038-046-
047.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ005>007.
OH...NONE.
KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
KYZ105.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ003-
004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...SL/26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
541 AM EST WED NOV 27 2013
.SYNOPSIS...
WINTER STORM SYSTEM LIFTS TO THE NORTHEAST. UPSLOPE SNOW TODAY AND
TONIGHT. HIGH PRESSURE BUILDING IN ON THANKSGIVING DAY AND
LINGERING FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
DEFORMATION ZONE HAS SET UP OVER THE WEST VIRGINIA LOWLANDS AND
HAS LITTLE EASTWARD MOTION TO IT. THIS MAY PROLONG THE DURATION OF
THE SYNOPTIC SNOW JUST A BIT FOR THE KANAWHA VALLEY AND I-79
CORRIDOR AND CONTRIBUTE TO MORE ACCUMULATION BEFORE THE TRANSITION
TO NORTHWEST FLOW SNOWFALL.
PREVIOUS DISCUSSION...
GENERALLY FOLLOWING THE HRRR MODEL IN REGARDS TO THE EVOLUTION OF
THE SYNOPTIC SNOW OVER THE NEXT FEW HOURS INTO THE DAWN HOURS.
DEFORMATION ZONE PROVIDING THE MAIN FORCING OF THE SNOW AT THIS
POINT WILL DRIFT TO THE EAST THROUGH 12Z TODAY...AND CARRY THE
BETTER CHANCES FOR SNOW WITH IT. THERE WAS A PATCH OF DRIER AIR TO
CONTEND WITH A FEW HOURS AGO DURING THE TEMPERATURE TRANSITION TO
BELOW FREEZING VALUES...AND HAVE GOTTEN OFF TO A SLOW START IN TERMS
OF ACCUMULATIONS. THIS SPARKS A FEW CONCERNS ABOUT MEETING THE
PREVIOUSLY FORECASTED AMOUNTS...BUT WILL NOT GIVE UP ON IT JUST YET
AS WE STILL HAVE A FEW HOURS TO GET SOME ACCUMULATIONS OUT OF THIS.
AS THE MAIN SYNOPTIC FORCING FOR THIS EVENT DEPARTS WITH THE
DEFORMATION ZONES PUSHING EAST OF THE MOUNTAINS AND THE 500MB TROUGH
AXIS PASSING LATER TODAY...THE SET UP LOOKS FAIRLY DECENT TO HAVE
CONVECTIVE SNOW FOR THE FIRST PART OF TODAY. LOOKING AT A CROSS
SECTION ORIENTED TO THE MEAN LOW LEVEL WIND SHOWS GOOD SATURATION
INTO THE CRYSTAL GROWTH LAYER...FED BY NORTHWEST FLOW THROUGH THE
LOW LEVELS. FIGURE THE NATURE OF THE SNOW WILL BE OFF AND ON AT THIS
POINT...BUT A QUICK INCH HERE AND THERE WILL BE POSSIBLE THROUGH 18Z
OR 20Z TODAY FOR THE LOWLANDS. THIS POTENTIAL INCREASED IN THE
MOUNTAINS IN THE BETTER UPSLOPE CONDITIONS. AFTER THAT...IT WILL
MAINLY BE A MOUNTAIN EVENT ONLY THAT WILL SLOWLY FADE DURING THE
OVERNIGHT PERIOD.
WINDS WILL BE ON THE INCREASE OUT OF THE NORTHWEST TODAY...WITH
GUSTS UP TO 30KTS AT TIMES. BLOWING SNOW OVER THE HIGHEST RIDGES IS
LIKELY LATER TODAY AND TONIGHT.
DID NOT GET CUTE WITH THE TEMPERATURES TODAY. MAX TEMPERATURES MAY
BE RIGHT AT DAWN AS THE COLDER AIR COMES IN...AND THEN WILL CHILL A
COUPLE DEGREES...BUT COULD MAKE A DEGREE OR TWO RECOVERY THROUGH THE
AFTERNOON TOWARDS THE MORNING VALUES. IN THE END...HIGHS AROUND 30F
WILL RULE FOR MUCH OF THE AREA...AND GETTING COLDER FOR THE
MOUNTAINS BY EVENING. OVERNIGHT...HAVE SNOWSHOE IN THE SINGLE
DIGITS...WITH OTHER LOCATIONS FALLING INTO THE TEENS TO LOWER 20S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
UPPER PATTERN ACROSS THE UNITED STATES RETURNS TO A ZONAL FLOW
THROUGH THE EARLY WEEKEND. THIS WILL KEEP THE COLDEST AIR WITH
CANADIAN HIGH PRESSURE CENTERS UP IN CANADA. EVEN THOUGH UPPER
IMPULSES WILL TRACK EASTWARD THROUGH THE FLOW...THEY WILL BE WEAK.
THIS..IN COMBINATION WITH GULF OF MEXICO MOISTURE BEING CONFINED
ACROSS THE SOUTHERN STATES...WILL BRING DRY CONDITIONS AND A DAY
TIME WARMING TREND. HIGH TEMPERATURES IN THE 30S THURSDAY WILL REACH
WELL INTO THE 40S FRIDAY AND SATURDAY. HOWEVER...THE DRY AIR ALONG
WITH LACK OF CLOUDS...WILL ALLOW FOR COLD NIGHT TIME READINGS WELL
BELOW FREEZING. THUS...LOOK FOR DRY WEATHER AND A LARGE RANGE IN
DIURNAL TEMPERATURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
A RATHER TRANQUIL ZONAL FLOW WITH SOME WEAK TROUGH APPROACHING LATE
IN THE WEEKEND. WILL CONTINUE BRINGING BACK SOME CHANCE POPS FOR
LIGHT RAIN SUNDAY NIGHT AND BECOMING MORE WIDESPREAD MONDAY BEFORE
DIMINISHING POPS MONDAY NIGHT. NOT ANY STRONG FEATURES OR
FRONTS EXPECTED DURING THIS PERIOD.
NO BIG DEVIATIONS FROM HPC MEDIUM RANGE GROUP TEMPERATURES.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
IFR FOR TERMINALS SOUTH AND EAST OF THE OHIO RIVER...SO EXPECT PKB
TO COME UP TO MVFR IN THE NEXT COUPLE OF HOURS FOR A SHORT PERIOD
OF TIME. HTS IS ALREADY THERE. AS THE BAND OF SNOW OVER THE WEST
VIRGINIA LOWLANDS SLOWLY RETREATS TO THE EAST...COULD GET SOME
BRIEF MVFR AND IFR IN THE TRANSITION TO UPSLOPE SNOW IN NORTHWEST
FLOW. WILL BE IN AND OUT OF SNOW SHOWERS FOR THE BULK OF THE
DAY...WITH MORE PERSISTENT SNOW FOR CKB...EKN..AND BKW.
OBSERVATIONS ARE EXPECTED TO BOUNCE...SO TEMPO GROUPS ARE THE TICKET
TODAY FOR THE OSCILLATING CONDITIONS.
WINDS TURN NORTHWESTERLY THIS MORNING...AND WILL INCREASE THROUGH
THE DAY. BY AFTERNOON HOURS...GUSTS 25-30KTS ARE NOT OUT OF THE
QUESTION...AND MAY SEE 35KTS OVER THE HIGHEST RIDGES. WINDS FALL
BACK DOWN TO THE 10-15KTS BY 12Z THURSDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: VISIBILITY RESTRICTIONS COULD VARY WITH SNOW.
CEILINGS WILL DROP SLIGHTLY IN HEAVIER SNOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY M H H H M L L L L L L M
HTS CONSISTENCY H H L M H H H M H H H H
BKW CONSISTENCY H H L L L L L L L L L L
EKN CONSISTENCY M M M M M M L L L L L L
PKB CONSISTENCY H H H L H L L L H M L L
CKB CONSISTENCY M M M H H M L L L L L L
AFTER 12Z THURSDAY...
NO WIDESPREAD IFR EXPECTED AFTER 12Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR WVZ035>037.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ008>011-013>020-024>034-039-040.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR WVZ038-046-
047.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ005>007.
OH...NONE.
KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
KYZ105.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ003-
004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
408 AM EST WED NOV 27 2013
.SYNOPSIS...
WINTER STORM SYSTEM LIFTS TO THE NORTHEAST. UPSLOPE SNOW TODAY AND
TONIGHT. HIGH PRESSURE BUILDING IN ON THANKSGIVING DAY AND
LINGERING FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
GENERALLY FOLLOWING THE HRRR MODEL IN REGARDS TO THE EVOLUTION OF
THE SYNOPTIC SNOW OVER THE NEXT FEW HOURS INTO THE DAWN HOURS.
DEFORMATION ZONE PROVIDING THE MAIN FORCING OF THE SNOW AT THIS
POINT WILL DRIFT TO THE EAST THROUGH 12Z TODAY...AND CARRY THE
BETTER CHANCES FOR SNOW WITH IT. THERE WAS A PATCH OF DRIER AIR TO
CONTEND WITH A FEW HOURS AGO DURING THE TEMPERATURE TRANSITION TO
BELOW FREEZING VALUES...AND HAVE GOTTEN OFF TO A SLOW START IN TERMS
OF ACCUMULATIONS. THIS SPARKS A FEW CONCERNS ABOUT MEETING THE
PREVIOUSLY FORECASTED AMOUNTS...BUT WILL NOT GIVE UP ON IT JUST YET
AS WE STILL HAVE A FEW HOURS TO GET SOME ACCUMULATIONS OUT OF THIS.
AS THE MAIN SYNOPTIC FORCING FOR THIS EVENT DEPARTS WITH THE
DEFORMATION ZONES PUSHING EAST OF THE MOUNTAINS AND THE 500MB TROUGH
AXIS PASSING LATER TODAY...THE SET UP LOOKS FAIRLY DECENT TO HAVE
CONVECTIVE SNOW FOR THE FIRST PART OF TODAY. LOOKING AT A CROSS
SECTION ORIENTED TO THE MEAN LOW LEVEL WIND SHOWS GOOD SATURATION
INTO THE CRYSTAL GROWTH LAYER...FED BY NORTHWEST FLOW THROUGH THE
LOW LEVELS. FIGURE THE NATURE OF THE SNOW WILL BE OFF AND ON AT THIS
POINT...BUT A QUICK INCH HERE AND THERE WILL BE POSSIBLE THROUGH 18Z
OR 20Z TODAY FOR THE LOWLANDS. THIS POTENTIAL INCREASED IN THE
MOUNTAINS IN THE BETTER UPSLOPE CONDITIONS. AFTER THAT...IT WILL
MAINLY BE A MOUNTAIN EVENT ONLY THAT WILL SLOWLY FADE DURING THE
OVERNIGHT PERIOD.
WINDS WILL BE ON THE INCREASE OUT OF THE NORTHWEST TODAY...WITH
GUSTS UP TO 30KTS AT TIMES. BLOWING SNOW OVER THE HIGHEST RIDGES IS
LIKELY LATER TODAY AND TONIGHT.
DID NOT GET CUTE WITH THE TEMPERATURES TODAY. MAX TEMPERATURES MAY
BE RIGHT AT DAWN AS THE COLDER AIR COMES IN...AND THEN WILL CHILL A
COUPLE DEGREES...BUT COULD MAKE A DEGREE OR TWO RECOVERY THROUGH THE
AFTERNOON TOWARDS THE MORNING VALUES. IN THE END...HIGHS AROUND 30F
WILL RULE FOR MUCH OF THE AREA...AND GETTING COLDER FOR THE
MOUNTAINS BY EVENING. OVERNIGHT...HAVE SNOWSHOE IN THE SINGLE
DIGITS...WITH OTHER LOCATIONS FALLING INTO THE TEENS TO LOWER 20S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
UPPER PATTERN ACROSS THE UNITED STATES RETURNS TO A ZONAL FLOW
THROUGH THE EARLY WEEKEND. THIS WILL KEEP THE COLDEST AIR WITH
CANADIAN HIGH PRESSURE CENTERS UP IN CANADA. EVEN THOUGH UPPER
IMPULSES WILL TRACK EASTWARD THROUGH THE FLOW...THEY WILL BE WEAK.
THIS..IN COMBINATION WITH GULF OF MEXICO MOISTURE BEING CONFINED
ACROSS THE SOUTHERN STATES...WILL BRING DRY CONDITIONS AND A DAY
TIME WARMING TREND. HIGH TEMPERATURES IN THE 30S THURSDAY WILL REACH
WELL INTO THE 40S FRIDAY AND SATURDAY. HOWEVER...THE DRY AIR ALONG
WITH LACK OF CLOUDS...WILL ALLOW FOR COLD NIGHT TIME READINGS WELL
BELOW FREEZING. THUS...LOOK FOR DRY WEATHER AND A LARGE RANGE IN
DIURNAL TEMPERATURE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
A RATHER TRANQUIL ZONAL FLOW WITH SOME WEAK TROUGH APPROACHING LATE
IN THE WEEKEND. WILL CONTINUE BRINGING BACK SOME CHANCE POPS FOR
LIGHT RAIN SUNDAY NIGHT AND BECOMING MORE WIDESPREAD MONDAY BEFORE
DIMINISHING POPS MONDAY NIGHT. NOT ANY STRONG FEATURES OR
FRONTS EXPECTED DURING THIS PERIOD.
NO BIG DEVIATIONS FROM HPC MEDIUM RANGE GROUP TEMPERATURES.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
IFR CONDITIONS DOMINATE THE FRONT END OF THE TAFS WITH THE RAIN
FINALLY CHANGING OVER TO SNOW. THERE COULD BE SOME BOUNCING OF THE
OBSERVATIONS IN AND OUT OF THE HEAVIER BATCHES OF SNOW PUSHING
THROUGH. BKW TO LIKELY STAY LIFR OVER THE NEXT FEW HOURS. ALL
LOCATIONS SHOULD BENEFIT FROM CEILING RISES AS THE WINDS BECOME
GUSTY OUT OF THE NORTHWEST. WILL STILL HAVE TROUBLE GETTING OUT OF
THE IFR CATEGORY...BUT SHOULD HAPPEN LATER TODAY.
AFTER SUNRISE TODAY...MUCH OF THE SYNOPTIC SCALE SNOW WILL HAVE
MOVED OUT AS WE LOSE THE BULK OF THE DEEPER MOISTURE.
HOWEVER...CONVECTIVE SNOW SQUALLS ARE POSSIBLE THROUGH 20Z
TODAY...WHICH SUPPORTS THE EXTENSION OF THE IFR VISIBILITIES.
HOWEVER...THESE WILL OFF AND ON IN NATURE...AND WILL LIKELY NEED
WIDE TEMPOS TO COVER FOR PERIODS WHEN THE SNOW STOPS.
VFR CONDITIONS CREEP IN LATER THIS EVENING FOR
HTS...EKN...PKB...AND BKW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: VISIBILITY RESTRICTIONS COULD VARY WITH SNOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 11/27/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY M H H H H M M M L L L L
HTS CONSISTENCY H H H M M L H H H H M H
BKW CONSISTENCY M M M H H L L L L L L L
EKN CONSISTENCY M M M M M M M M M L L L
PKB CONSISTENCY M M M M M M L L L L L H
CKB CONSISTENCY H H H H H M M M M L L L
AFTER 06Z THURSDAY...
IFR CONDITIONS EXPECTED WEDNESDAY NIGHT IN SNOW DUE TO A LINGERING
WINTER STORM SYSTEM...PARTICULARLY ACROSS THE MOUNTAINS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 1 AM EST THURSDAY FOR WVZ035>037.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
WVZ008>011-013>020-024>034-039-040.
WINTER STORM WARNING UNTIL 4 AM EST THURSDAY FOR WVZ038-046-
047.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ005>007.
OH...NONE.
KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
KYZ105.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ003-
004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...KTB
AVIATION...26
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
857 AM CST WED NOV 27 2013
.UPDATE...
SNOW FALLING IN EASTERN AREAS OF MID STATE WITH SOME ACCUMULATION
ALONG THE PLATEAU. HAVE UPDATED GRIDS AND ZONES TO INCLUDE UP TO
AN INCH OF SNOW MAINLY UPPER CUMBERLAND AREAS WITH AROUND HALF
INCH WEST OF PLATEAU AS FAR BACK AS MACON...SMITH AND MAYBE
DEKALB.
700 MBAR TROUGH AXIS NORTH TO SOUTH JUST EAST OF INTERSTATE 65 WITH A
SHOT OF WARM ADVECTION AT 850 MBAR SHOWING UP IN RUC NOSING IN
ACROSS NORTHEAST MIDDLE TENNESSEE INTO UPPER CUMBERLAND. WITH THIS
SETUP THINK UPPER CUMBERLAND WILL SEE AT LEAST 1 INCH OF ACCUMULATION
AND MAYBE A LITTLE MORE BEFORE ENDING. WILL HOLD OFF ON ADVISORY
FOR NOW BUT NOT SURE HOW LONG I CAN.
BOYD
&&
.PREV DISCUSSION... /ISSUED 532 AM CST WED NOV 27 2013/
UPDATE...FOR AVIATION.
AVIATION...
BNA AND CKV 12Z TAFS...VFR WX IS EXPECTED TODAY WITH GUSTY NNW
WINDS TO 25KT AT TIMES. BKN STRATO CU WILL BECOME SKC THROUGH THE
DAY. FOR TONIGHT...WINDS WILL BECOME LIGHT NW WITH SKC UNDER COLD
HIGH PRESSURE.
CSV...MVFR CIGS WILL PERSIST THROUGH 18Z...THEN IMPROVE IN THE
AFTERNOON. GUSTY NNW WINDS TO 25KT EARLY TODAY WILL BECOME LIGHT
BY 28/00Z.
13
PREV DISCUSSION... /ISSUED 412 AM CST WED NOV 27 2013/
DISCUSSION...
FORECAST REASONING WILL LEAN TOWARD A CONSENSUS MODEL SOLUTION
COMPROMISE FOR THE FORECAST PERIOD UNLESS OTHERWISE NOTED.
FORECAST QUANDARIES...TEMPS...WX PATTERN FIRST PART OF NEXT WEEK.
JUST WENT AHEAD AND ISSUED THE SUITE OF FORECAST PRODUCTS FOR TODAY
AS THE POTENTIAL FOR ACCUMULATING SNOWFALL HAS ENDED ACROSS THE
UPPER CUMBERLAND REGION...WITH POSSIBLY SOME ISO FLURRIES THRU THE
MID MORNING HRS. OTHERWISE...BUILDING SFC RIDGING INFLUENCES WILL BE
THE MAJOR WX PLAYER THRU THE REST OF THE WEEK AND INTO AT LEAST THE
FIRST PART OF THE WEEKEND. A STRONG SFC PRESSURE GRADIENT HAS BEEN
ESTABLISHED ACROSS THE MID STATE THIS MORNING WITH NWLY SUSTAINED
WINDS GENERALLY 10 TO 20 MPH WITH SOME GUST APPROACHING 30 MPH.
BELIEVE THAT ON WHOLE THIS TYPE OF RANGE OF WIND SPEEDS EXPECTED
AT LEAST THRU THE EARLY AFTERNOON HRS TODAY UNTIL SFC RIDGING INFLUENCES
BUILD CLOSER. ALSO EXPECTING DECREASING CLOUDINESS W TO E AS THE
DAY PROGRESSES WITH DRY NW FLOW PATTERN ALOFT CONTINUING AT LEAST THRU
TONIGHT AFTER THIS MORNING EXPECTED UPPER LEVEL TROUGH PASSAGE. THIS
BUILDING HIGH PRESSURE SYSTEM WILL USHER AN ADDITIONAL SHOT OF COLD AIR
TO THE MID STATE...WITH HIGHS TODAY IN RANGE OF CURRENT 10Z VALUES..
I.E. MAINLY IN THE LOWER 30S. A DEGREE OR TWO DIFFERENCES HERE OR THERE
BETWEEN 00Z NAM/GFS/EURO MOS WITH A GENERAL LEAN TOWARD THE MORE MIDDLE
OF THE ROAD GFS MOS VALUES FOR EXPECTED HIGH TEMPS FOR TODAY TAKEN.
AS OF THIS TIME...ACTUALLY FORECASTING A HIGH FOR NASHVILLE OF 33 DEGREES...
A COUPLE OF DEGREES WARMER THAN THE RECORD LOW MIN HIGH OF 31 DEGREES SET
FOR THIS DATE IN 1938. HOWEVER...WITH THE ABOVE WINDS SPEEDS EXPECTED...
WIND CHILL VALUES WILL GENERALLY AVERAGE IN THE UPPER TEENS DURING THE
DAY ACROSS THE MID STATE. WITH WINDS GENERALLY BECOMING LIGHT...LOWS
TONIGHT ARE EXPECTED TO MAINLY BE IN THE MID TO UPPER TEENS.
EXPECTING A GENERALLY WARMING TREND TOWARD MORE SEASONAL VALUES WITH DRY
CONDITIONS DUE TO SFC RIDGING INFLUENCES WITH UPPER LEVEL FLOW BECOMING
MORE ZONALLY ALIGNED ALLOWING FOR SOME PASSING MID TO UPPER LEVEL
CLOUDINESS...BUT GENERALLY MOCLR SKIES EXPECTED...FOR THE REST OF THE
WEEK AND INTO AT LEAST THE FIRST PART OF THE WEEKEND. HIGHS ON THANKSGIVING
DAY SHOULD GENERALLY BE IN LOWER 40S...WITH LOWS THURSDAY NIGHT MAINLY IN
THE LOWER 20S. HIGHS ON FRI ARE EXPECTED TO BE AROUND 50 DEGREES WITH LOWS
FRI NIGHT GENERALLY IN THE MID TO UPPER 20S. HIGHS ON SAT WILL GET EVEN
CLOSER TO SEASONABLE NORMAL VALUES WITH HIGHS MAINLY IN THE LOWER 50S AND
LOWS SAT NIGHT BACK CLOSE TO SEASONABLE NORMAL VALUES MAINLY IN THE LOWER 30S.
LOOKS LIKE THE NEXT BEST CHANCE OF RAINFALL WILL BE ON SUN AS A WEAK SFC
FRONT MOVES CLOSER TO THE MID STATE. SOME TIMING DIFFERENCES IN MODELS FOR
THE FIRST PART OF NEXT WEEK...BUT GENERALLY EXPECTING WEAK DISTURBANCES IN
UPPER LEVEL FLOW ALOFT...ALONG WITH A MORE PRONOUNCED UPPER LEVEL TROUGH
PASSAGE BY LATE ON MON...ALONG ALSO WITH SLY SFC FLOW...TO ALL COMBINE TO
GIVE US A CHANCE OF RAIN SUN NIGHT INTO MON...WITH TEMPS NEAR SEASONABLE
NORMS. RIDGING INFLUENCES SHOULD AGAIN BUILD ACROSS THE MID STATE BY THE
MID PORTION OF NEXT WEEK ALSO.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS SPOKANE WA
224 PM PST Wed Nov 27 2013
.SYNOPSIS...
Little change in the weather is expected through Friday, but big
changes are coming this weekend and continuing into next week.
This air-mass change will bring gusty winds, increased chances for
precipitation and much, much colder temperatures.
&&
.DISCUSSION...
Tonight and Thanksgiving Day...A stale and persistent weather
pattern will continue through the next 24 hours. Aloft...the
deep trough off the coast will pinch off into a closed low far to
the south...promoting a transition to westerly flow aloft over the
forecast area...but this high altitude flow transition will do
nothing to impact the boundary layer which will remain locked
under an inversion lid. Thus...forecast for tonight will resemble
what occurred last night...and the forecast for tomorrow will
resemble what happened today...and yesterday...and the day before.
Morning fog and stratus in valley locations...eventual break out
into partly sunny conditions...cool temperatures and light winds.
After coordination with air quality authorities it was decided to
extend the Air Stagnation Advisory until Saturday afternoon when
confidence is increasing for an erosion of the stubborn inversion.
/Fugazzi
Thursday night to Saturday night: Precipitation chances increase
as the upper ridge breakdown continues and a strong system starts
to drop along the B.C. coast. Through the period the Inland
Northwest remains in west-northwest flow. The jet axis remains
just north of the region. Two upper disturbances slip by ahead of
that developing system. These will bring some precipitation
chances.
The first threat comes to the Cascades and Canadian border
Thursday night. The threat expands throughout all but the deeper
Columbia Basin between Friday and Saturday, as isentropic ascent
strengthens and moisture deepens. Based on condensation pressure
deficits (CPD), the best moisture and highest precipitation comes
to the northern mountain by early Friday, then expands across the
eastern third of WA and the central ID Panhandle by late Friday
afternoon and evening. It lingers here through Saturday and
Saturday night. The threat of precipitation will only be enhanced
Saturday night, especially near the Cascades at the strong system
comes to our doorstep.
Precipitation-type is expected to be mainly valley rain and
mountain snow during the daylight hours. A mix may reach valley
floors, especially across the north, at night. Overall
precipitation amounts are expected to be light, owning to the fact
high pressure lingers in the low levels and that lift is generally
not too deep. A quick inch of snow is possible over the mountains
late Friday/Friday night, especially toward the Panhandle and some
accumulation is possible again starting Saturday night especially
near the Cascades. However precise snow levels around the Cascades
may just above pass level. Stay tuned.
Surface high pressure will continue to limit mixing and allow
stagnant air conditions to persist, at least until that stronger
system approaches. I also kept some patchy fog in the forecast for
Thursday night and Friday morning in areas which has seen in the
past few days, including the sheltered northeast valleys and L-C
Valley. /J. Cote`
...A VERY COLD WINTER STORM TO IMPACT THE REGION OVER THE HOLIDAY
WEEKEND...
Sunday through Wednesday: Models remain in strong agreement that
a deep, cold low pressure system will drop into the region over
the weekend. A 140-160kt northerly jet off the Western Canadian
Coast will deliver the system to the Pac NW and continue to feed
very cold air southward setting up what looks to be the coolest
week we have experienced in some time. Initially (Sunday), A
warm moisture conveyor belt of subtropical moisture ahead of the
wave will bring mainly valley rain and mountain snow with a brief
upward trend in snow levels. However, snow levels will quickly
drop to valley floors behind a cold front Sunday night into Monday
morning bringing the potential for valley snowfall. Cold conditions
will remain in place through much of the week.
* Model uncertainty: Several differences noted in the models
yesterday or today continue to keep some uncertainty with the
forecast. First off, the timing of the initial cold front is now
more agreed upon and looks to favor the Euro`s Sunday night
time-frame. What is still in question is the exact track of the
upper-level low, the orientation of the jet streak rounding the
base of the low, and where the low sets up. This is leading to
large uncertainty with the wind gust potential and snow levels
on Sunday then amount of valley snow Monday. Until these
features can be determined, the forecast will continue to carry
a modest amount of uncertainty.
* Snow/Rain: Good agreement that moist isentropic ascent will
bring widespread precipitation Sunday and Sunday night until
the cold front passage. the exception is in the immediate lee of
the Cascades where some shadowing will take place. We are fairly
certain all valleys south of Hwy 2 to Spokane and south of I-90
will be rain or transition from wet snow to rain. Models suggest
the Methow and Okanogan Valleys will also be rain but given the
terrain resolution of the GFS/Euro, we are not sold completely
yet. The Euro, which has more of a northwest jet
streak...maintains enough cold air over far NE WA and Nrn ID to
support snow levels around 2300-2500` between Sandpoint and
Bonners Ferry while the GFS surges levels near 6000`. If it was
to fall as snow, it could be the heavy wet variety. Aside from
Snoqualmie Pass, all other passes will experience snow on Sunday
and Sunday night but a mix with rain will be possible for a
period of time at Stevens and Lookout, pending which model`s
snow level verifies. The cold front will slide through Sunday
night and should be into northern Oregon by Monday morning. Any
precipitation from that point onward will be all snow no matter
what elevation. If the Euro track was to pan out, several waves
pivoting within the mean low will lead to valley snow for just
about any location from the Cascades to the MT border. The GFS
suite on the other hand would keep any valley snow confined
mainly to the ID Panhandle and portions of SE WA.
* Wind: Gusty south to southwest winds will develop Sunday within
the warm sector. A low-level jet with winds of 45-60kts will
bring strong gusts to the ridgetops but is not expected to mix
to the valley floors. Following the orientation of the Euro`s
jet which is nw to se across the Cascades, there is a potential
for strong wind gusts in the form of breaking mountain waves.
Otherwise, there is threat for a brief period of strong winds
just about every location as the actual cold front pushes
through. As the arctic air bleeds into the region, breezy to
gusty north winds will setup down the narrow channels of the
Okanogan Valley and spill into the Western Basin while northeast
winds channel down the Purcell Trench into the Eastern Basin.
Winds of 15 to 30 mph with gusts in excess of 40 mph will be
possible with each of these gradient driven winds.
* Temperatures: Temperatures will be quite mild for November`s
standards Sunday with the region in the warm sector. These
temperatures will come crashing down on Monday and continue to
cool for Tuesday and Wednesday when the true arctic air arrives.
850mb temperatures will be cooling from 0 to +4 Sunday toward
-6C on Monday toward -12C on Wednesday. This will equate to high
temperatures from the 30`s and 40`s Sunday to 10`s and 20`s
Tues/Wed. Lows will be much more of a wildcard without knowing
if snow will be present on valley floors. The air mass itself
would suggest single digits to teens but any new snow in the
valleys could easily bring negative single or double digit
readings to the table. /sb
&&
.AVIATION...
18Z TAFS: Fg and stratus extending from Bonners Ferry to Spokane and
along most rivers/lakes should begin breaking btwn 20-21z. Until
then...LIFR/IFR cigs/vis will impact operations at
GEG/SFF/COE/LWS. Once the low clouds break...VFR conditions can be
expected with sct-bkn cigs btwn 10-20K AGL. High pressure remains
in control aloft and should deliver a near persistent fcst tonight
leading to fg and stratus redeveloping through the evening and
overnight hours. Confidence is generally lowest regarding the
timing of the fog breakup this morning and timing of redevelopment
tonight. Fcst favored guidance from the HRRR with a nod to
climatology. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 25 37 26 40 30 40 / 0 0 0 20 20 20
Coeur d`Alene 27 39 28 40 32 40 / 0 0 0 20 40 30
Pullman 27 45 28 42 32 43 / 0 0 0 10 30 20
Lewiston 27 40 29 45 34 46 / 0 0 0 10 20 20
Colville 24 37 26 38 28 39 / 0 0 0 30 30 40
Sandpoint 22 37 26 38 31 38 / 0 0 10 20 40 30
Kellogg 28 43 29 40 33 38 / 0 0 10 20 50 40
Moses Lake 19 38 22 42 27 43 / 0 0 0 10 10 10
Wenatchee 23 39 28 41 31 42 / 0 0 0 10 10 10
Omak 19 35 25 40 28 40 / 0 0 0 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until 4 PM PST Saturday for Central
Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis
and Southern Nez Perce Counties-Lewiston Area-Northern
Panhandle.
WA...Air Stagnation Advisory until 4 PM PST Saturday for East Slopes
Northern Cascades-Lower Garfield and Asotin Counties-Moses
Lake Area-Northeast Mountains-Okanogan Highlands-Okanogan
Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1057 AM PST Wed Nov 27 2013
.SYNOPSIS...
Little change in the weather is expected today and tomorrow,
but big changes are coming this weekend and continuing into next
week. This air-mass change will bring gusty winds, increased chances
for precipitation and much, much colder temperatures.
&&
.DISCUSSION...
Rest of Today...No significant changes to the inherited forecast
fro today`s weather...except to extend the longevity of fog and
low clouds into the afternoon for the northern valleys and minor
tweaks to expected high temperatures...only some stations and
only a degree or two based on current observations and trends.
The other issue is the Air Stagnation Advisory. After coordination
with state and county air quality authorities it has been decided
to extend the ASA until 4 pm Saturday given the weak likelihood
that the precursor systems to Sunday`s big change will dent the
inversion prior to at least Saturday. Otherwise...no significant
weather issues with another day of cool and stale conditions. /Fugazzi
&&
.AVIATION...
18Z TAFS: Fg and stratus extending from Bonners Ferry to Spokane and
along most rivers/lakes should begin breaking btwn 20-21z. Until
then...LIFR/IFR cigs/vis will impact operations at
GEG/SFF/COE/LWS. Once the low clouds break...VFR conditions can be
expected with sct-bkn cigs btwn 10-20K AGL. High pressure remains
in control aloft and should deliver a near persistent fcst tonight
leading to fg and stratus redeveloping through the evening and
overnight hours. Confidence is generally lowest regarding the
timing of the fog breakup this morning and timing of redevelopment
tonight. Fcst favored guidance from the HRRR with a nod to
climatology. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 25 39 26 40 30 / 0 0 0 0 0 20
Coeur d`Alene 39 25 40 27 41 31 / 0 0 0 0 0 30
Pullman 45 25 44 28 43 32 / 0 0 0 0 0 20
Lewiston 40 28 42 30 46 34 / 0 0 0 0 0 20
Colville 37 23 38 25 39 28 / 0 0 0 0 30 30
Sandpoint 37 22 38 25 39 30 / 0 0 0 10 20 30
Kellogg 43 26 43 29 39 32 / 0 0 0 10 10 40
Moses Lake 38 21 39 23 43 28 / 0 0 0 0 0 0
Wenatchee 39 26 39 28 41 30 / 0 0 0 0 0 0
Omak 35 21 36 24 40 28 / 0 0 0 0 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until 4 PM PST Saturday for Central
Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis
and Southern Nez Perce Counties-Lewiston Area-Northern
Panhandle.
WA...Air Stagnation Advisory until 4 PM PST Saturday for East Slopes
Northern Cascades-Lower Garfield and Asotin Counties-Moses
Lake Area-Northeast Mountains-Okanogan Highlands-Okanogan
Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
915 AM PST Wed Nov 27 2013
.SYNOPSIS...
Little change in the weather is expected today and tomorrow,
but big changes are coming this weekend and continuing into next
week. This air-mass change will bring gusty winds, increased chances
for precipitation and much, much colder temperatures.
&&
.DISCUSSION...
Today...There really isn`t much more to say than what we have
been saying the last several days. The ridge of high pressure that
has anchored itself will continue to get nudged to the east. More
of the same weather-wise today and tonight, but the first hints of
a change will come on....
Thanksgiving Day...A shift from the dominant ridge of high pressure
to a more westerly or west-northwesterly flow will commence late
Thanksgiving day. A very minor shortwave will traverse the Inland
Northwest Thursday afternoon. Much of the affects associated with
this shortwave remain well north, and only minor pops were
included for the northern Cascades. Weak mixing will continue, so
we don`t expect much of an air-mass change....yet. This wave will
be the beginning of a much more active pattern continuing into
next week. ty
Friday through Saturday...The high amplitude ridge which has blanketed
the Inland Northwest for the past week will finally give way to a
increasingly zonal or westerly flow pattern. This will transition
our dry and cool air mass to a warmer and more moisture laden one.
This transition will be accompanied by an increasing chance of
precipitation, but the question is when will it arrive. Models in
decent agreement that the first chances of precipitation will
impact the northern third of the forecast area on Friday as a weak
warm front brushes the Canadian Border. That means locations
generally north of the Highway 2/I90 corridor will see a chance of
light precipitation especially during the afternoon. Precipitation
type is a little tricky as the models are generally insistent that
wet bulb temperatures would support valley rain and mountain snow.
However mixing potential is not great ahead of the warm front so
it possible the valleys could hold onto snow or a rain/snow mix
through the day. In either case, the precipitation amounts will be
light so the impacts will be slight.
Through Friday night...the front will continued to droop to the
south...which should spread the precipitation chances across the
remainder of the Inland Northwest. Again precipitation amounts
will be light...but snow levels could remain tricky as warming
above the ground will likely outpace the warming near the ground.
By Saturday the warming will likely overcome any sub-freezing air
trapped near the ground as a more robust 850 mb low tracks through
central BC. This will enhance the mixing potential and increase
the moisture even further. Precipitation chances will likely be at
their highest during this period...but given the predominant
westerly flow...most of the Basin will be skipped over. Meanwhile
the Cascades should see relatively highs chances of measurable
precipitation as will the Idaho Panhandle. Precipitation amounts
will remain light. fx
...A VERY COLD WINTER STORM TO IMPACT THE REGION OVER THE HOLIDAY
WEEKEND...
Saturday night through Wednesday: The longwave pressure pattern
will take a dramatic shift during this period. An upper level
ridge of higher pressure will build over the eastern Pacific into
Alaska as a strong upper level low pressure system carves its way
down western Canada into the Northwest. Between these two upper
level pressure systems will be a 160 kt northwest to southeast
oriented jet directed toward Washington State. A moisture plume
with P-wats of around 0.75 inches will ride this jet into the
Inland Northwest. The low pressure system will also be accompanied
by a strong cold front that will sag southward out of BC. This
front will interact with this moisture off of the Pacific to
produce a band of precip that sags from north to south beginning
Saturday and continuing into Sunday. This is where models are in
fairly good agreement. Models begin to diverge as the upper level
low begins to enter the region out of BC. The 00Z ECMWF and
Canadian model guidance shows the upper level low taking a more
westerly track across western WA and is more consolidated as it
does so. The 00Z and 06Z GFS model runs are more muddled with the
track of the low. It is far less consolidated and has a more broad
ahead of low pressure from western WA into central MT. The best
dynamics off the GFS runs tracks further east into MT. Considering
that the GFS has been less consistent and has generally been
catching up to ECMWF and Canadian, I would not be surprised if the
GFS trends more toward the ECMWF and Canadian solutions. If the
ECMWF/Canadian solution pans out, then we will be looking at a
better potential for heavier valley snowfall for Sunday night into
Monday.
* Precipitation: Strong warm air advection ahead of the cold front
Saturday into Sunday will result in primarily valley rain and
mountain snow. Strong westerly flow will also likely produce a
noticeable rain shadow directly east of the Cascade Mtns. This
will result in the heaviest precip occurring along the Cascade
crest and in the ID Panhandle. Heavy mountain snow can be
expected with snow levels starting out around 3,500 feet and
increasing to up around 5,000 feet on Sunday. The exception will
be across the northern mtns and vlys where colder air may hold
out. A rain/snow mix will be possible across these northern
valleys at onset, but should become all rain as snow levels
surge up on Sunday. Cold arctic air will then funnel in Sunday
night into Monday with snow level crashing to valley floors.
This will be the best chance for valley snowfall, especially if
the wetter more westward track of the upper level low verifies.
* Winds: A strong low level jet is expected in the warm sector of
this system on Sunday with 850 mb winds at around 40-50 kts.
This will likely create breezy conditions across the basin, but
the strongest winds will likely be reserved for the mountains;
ridge top winds are expected to gust upwards of 50 mph. Better
mixing potential will be possible with the cold front Sunday
evening/night where some higher wind gusts will be possible.
* Temperatures: Frigid temperatures are expected as cold arctic
air pushes into the region from Canada. Temperatures will drop
dramatically from Sunday into Monday with a 10-20 degree drop
expected in high temperatures. Temperatures will only continue
to get colder into early next week as the upper level low
continues to dig across the western U.S. Low temperatures will
have the potential to dip into the single digits. Some negative
temperatures will be possible by Tuesday night and Wednesday
night. Northerly winds down the Okanogan Valley and through the
Purcell Trench may also result in some very cold wind chill
values, especially Monday night through Tuesday night. /SVH
&&
.AVIATION...
18Z TAFS: Fg and stratus extending from Bonners Ferry to Spokane and
along most rivers/lakes should begin breaking btwn 20-21z. Until
then...VIFR/IFR cigs/vis will impact operations at GEG/SFF/COE/LWS.
Once the low clouds break...VFR conditions can be expected with
sct-bkn cigs btwn 10-20K AGL. High pressure remains in control
aloft and should deliver a near persistent fcst tonight leading to
fg and stratus redeveloping through the evening and overnight
hours. Confidence is generally lowest regarding the timing of the
fog breakup this morning and timing of redevelopment tonight. Fcst
favored guidance from the HRRR with a nod to climatology. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 38 25 39 26 40 30 / 0 0 0 0 0 20
Coeur d`Alene 40 25 40 27 41 31 / 0 0 0 0 0 30
Pullman 44 25 44 28 43 32 / 0 0 0 0 0 20
Lewiston 40 28 42 30 46 34 / 0 0 0 0 0 20
Colville 37 23 38 25 39 28 / 0 0 0 0 30 30
Sandpoint 37 22 38 25 39 30 / 0 0 0 10 20 30
Kellogg 43 26 43 29 39 32 / 0 0 0 10 10 40
Moses Lake 38 21 39 23 43 28 / 0 0 0 0 0 0
Wenatchee 38 26 39 28 41 30 / 0 0 0 0 0 0
Omak 35 21 36 24 40 28 / 0 0 0 0 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until 10 AM PST Friday for Central
Panhandle Mountains-Coeur d`Alene Area-Idaho Palouse-Lewis
and Southern Nez Perce Counties-Lewiston Area-Northern
Panhandle.
WA...Air Stagnation Advisory until 10 AM PST Friday for East Slopes
Northern Cascades-Lower Garfield and Asotin Counties-Moses
Lake Area-Northeast Mountains-Okanogan Highlands-Okanogan
Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-
Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
530 PM CST THU NOV 28 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
AT 3 PM...A LAKE INDUCED VORTICITY WAS LOCATED OVER THE APOSTLE
ISLANDS IN WESTERN LAKE SUPERIOR. MEANWHILE A SURFACE LOW WAS
LOCATED OVER EASTERN UPPER MICHIGAN. THIS LOW WAS PRODUCING WEAK
CYCLONIC FLOW ACROSS ACROSS WISCONSIN AND EAST CENTRAL MINNESOTA.
THIS CYCLONIC FLOW ALONG WITH STEEP 950-900 MB LAPSE RATES
/ASSOCIATED WITH A THERMAL TROUGH LOCATED FROM NORTHERN MINNESOTA
SOUTHEAST INTO EASTERN WISCONSIN/ IS HELPING MAINTAIN THESE
CLOUDS. THE 28.19Z RAP HAS A VERY GOOD HANDLE ON THESE CLOUDS AND
THEY SHOW THAT THEY WILL CONTINUE TO MOVE SOUTHEAST ACROSS MAINLY
OUR WISCONSIN COUNTIES AND THEN QUICKLY DISSIPATES THEM BETWEEN
28.01Z AND 28.03Z AS THE FLOW STARTS TO BECOME ANTICYCLONIC AND
THE 950-900 MB LAPSE RATES DECREASE.
FROM LATE TONIGHT INTO FRIDAY...THE 28.12Z MODELS CONTINUE TO
SHOW THAT WEAK WARM AIR ADVECTION WILL DEVELOP ABOVE 600 MB AS A
WEAK SHORT WAVE TROUGH APPROACHES THE REGION FROM THE CENTRAL
PLAINS. THIS WILL RESULT IN SOME MID TO HIGH CLOUDS ACROSS THE
AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
ON FRIDAY NIGHT...THE 28.12Z MODELS CONTINUE TO SHOW THAT A STRONG
SHORT WAVE TROUGH WILL MOVE SOUTHEAST ACROSS SOUTHWEST ONTARIO.
MUCH OF THE PV ADVECTION ASSOCIATED WITH THIS SYSTEM STAYS WILL
NORTH OF THE FORECAST AREA. THERE IS WEAK TO MODERATE 285 TO 300K
ISENTROPIC LIFT ACROSS NORTHERN AND EASTERN WISCONSIN. THIS LOWERS
THE CONDENSATION PRESSURE DEFICITS TO LESS 40 MB. MEANWHILE AT THE
285 AND 290K ISENTROPIC SURFACES YOU STILL NEED 100 TO 200 MB
OF LIFT FOR SATURATION. AS A RESULT...IT IS NOT LOOKING PROMISING
FOR ANY PRECIPITATION ACROSS TAYLOR AND NORTHERN CLARK COUNTY IN
NORTH CENTRAL WISCONSIN. HOWEVER WITH THE ECMWF...GEM...AND NAM
STILL INDICATING A POSSIBILITY. JUST KEPT A SLIGHT CHANCE /LESS
THAN 20 PERCENT/ ACROSS THIS AREA. BUFKIT SOUNDINGS CONTINUE TO
SHOW NO ICE...SO IF PRECIPITATION DOES INDEED OCCURS IT WOULD BE
IN THE FORM OF FREEZING DRIZZLE.
ON SATURDAY NIGHT...WEAK TO MODERATE WARM AIR ADVECTION AND STRONG
290 TO 300K ISENTROPIC LIFT DEVELOP ACROSS THE AREA AS A STRONG
SHORT WAVE TROUGH MOVES ACROSS THE REGION. THE 290-300K ISENTROPIC
CONDENSATION PRESSURE DEFICITS DROP TO LESS THAN 30 MB...SO WE
WILL LIKELY SEE CLOUDS WITH THIS WAVE. HOWEVER...THE 285K
CONDENSATION DEFICITS REMAIN IN THE 100 TO 200 MB RANGE...SO NOT
EXPECTING ANY PRECIPITATION WITH THIS WAVE.
FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE
WITH THE TIMING OF A SHORT WAVE TROUGH COMING OUT AHEAD OF THE
DEVELOPING LONG WAVE TROUGH IN THE WESTERN UNITED STATE. BOTH THE
GEM AND ECMWF BRING A WAVE AHEAD OF THIS SYSTEM. MEANWHILE THE GFS
DOES NOT. AS AS RESULT...THE GEM AND ECMWF PRODUCES SOME LIGHT
PRECIPITATION ACROSS THE AREA. MEANWHILE THE GFS KEEPS THE AREA
DRY. SINCE THE MODELS HAVE BEEN CONSISTENT...JUST STAYED WITH THE
SLIGHT CHANCES THAT THE ALL BLEND PROVIDED.
FROM MONDAY NIGHT THROUGH THURSDAY...THE MODELS CONTINUE TO
STRUGGLE WITH THE EVOLUTION OF A LONG WAVE TROUGH OVER THE WESTERN
UNITED STATES. DUE TO THIS...THERE HAS BEEN A VARIETY OF DIFFERENT
LOW PRESSURE TRACKS FROM THE NORTHERN PLAINS EAST INTO THE GREAT
LAKES. THIS SYSTEM HAS THE POTENTIAL OF PRODUCING A WINTER STORM
SOMEWHERE ACROSS THE REGION...BUT WHERE IS VERY UNCERTAIN...SO
JUST STAYED WITH THE ALL BLEND FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 530 PM CST THU NOV 28 2013
BANK OF VFR/MVFR STILL LINGERING ACROSS MUCH OF WI EARLY THIS
EVENING...BUT HAS BEEN SHOWING SOME DIMINISHING TREND/MOVEMENT EAST
PER LATEST FOG/STRATUS SATELLITE IMAGERY. EXPECT THIS TREND TO
CONTINUE...WITH SKC/SCT CONDITIONS AT KLSE BY 03Z.
LIGHT TO VRB WINDS DURING THE NIGHT TIME HOURS. WINDS WILL INCREASE
AND SHIFT TO THE SOUTH/SOUTHEAST A FEW HOURS AFTER DAYBREAK FRIDAY
AS HIGH PRESSURE EXITS OVER THE EASTERN GREAT LAKES. SHOULD SEE SOME
HIGH/MID LEVEL CLOUDS BY THIS TIME...MOSTLY IN THE 150-250 KFT
RANGE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 PM CST WED NOV 27 2013
.SHORT TERM...(THIS EVENING THROUGH THANKSGIVING)
ISSUED AT 310 PM CST WED NOV 27 2013
OVERALL A QUIET WEATHER PERIOD THROUGH THE WEEKEND...AFTER SOME
LIGHT SNOW ACROSS THE NORTH TONIGHT.
HAVE BEEN MONITORING SHORTWAVE TROUGH 1 MOVING INTO MINNESOTA
THIS AFTERNOON WITH LIGHT SNOW IN THE 1-2SM VISIBILITY
RANGE...WITH A BIT LOWER FURTHER NORTHWEST ALONG THE MN/CANADA
BORDER. ECHO IS INCREASING IN NW WI...BUT THE PRECIPITATION IS
WORKING ON SATURATION AND NOT MAKING IT TO THE SURFACE. THE UPPER
TROPOSPHERIC SHORTWAVE TROUGH IS LOCATED IN NWRN MN AT 20Z PER
GOES WATER VAPOR IMAGERY...WITH SHORTWAVE TROUGH 2 ON ITS HEALS
JUST NORTHWEST OF LAKE WINNIPEG. MORNING RAOB AT KMPX WAS DEEPLY
DRY BUT THE FORCING WITH THE SHORTWAVE TROUGH IS WORKING PRETTY
RAPIDLY TO SATURATE THE COLUMN AND PRODUCE SNOW....ON THE ORDER OF
A COUPLE HOURS. PER THE LATEST RAP...THIS FORCING IS A
CONTRIBUTION FROM WARM ADVECTION IN THE LOW LEVELS / AND 700MB
FRONTOGENESIS/ AND MID-UPPER LEVEL QG CONVERGENCE.
THE FIRST SHORTWAVE WILL TRACK TOWARD THE NORTHERN FORECAST AREA THIS
AFTERNOON AND ARRIVE AROUND 6-7 PM IN CLARK AND TAYLOR COUNTIES
PER RAP FORECASTS AND TRACKING. THIS FIRST SHORTWAVE TROUGH
WEAKENS AS IT MOVES IN PER THE CONSENSUS MODEL GUIDANCE AS THE
SECOND WAVE INTENSIFIES AND DEEPENS. HOWEVER...THERE IS GUIDANCE
/HRRR/ SOLUTIONS DIMINISHING THE WEATHER AS IT MOVES SOUTHEAST
AND DRY AIR IN PLACE WILL DOMINATE. WITH CONSENSUS FORCING SWIPING
A BAND OF SNOW IN THE EVENING AND CURRENT CONDITIONS...HAVE
FORECAST THE SNOW TO MOVE IN DURING THE EVENING AND ACCUMULATE...MAINLY
I-94 AND NORTH. THIS IS NOT A BIG CHANGE TO ONGOING FORECAST..BUT
HIGHER CONFIDENCE. WILL LIKELY HIT THIS A BIT IN THE SOCIAL MEDIA
AND SPECIAL WEATHER STATEMENTS WITH MORE TRAVEL THIS EVENING
HAPPENING.
SOME DIFFICULTY IN TRYING TO FIGURE OUT THE REMAINDER OF THE
NIGHT AFTER MIDNIGHT...AHEAD OF THE SECOND SHORT WAVE TROUGH. IT
APPEARS THE FRONTOGENESIS NEAR 700MB WILL BE STRONGER THAN THE
FIRST SHORTWAVE AND WITH THE UPPER QG FORCING MAINLY OVER NRN WI
/MODEL CONSENSUS/...SNOW SEEMS TO BE A GIVEN. BUT AS SHORTWAVE
TROUGH 2 DEEPENS...THE FORCING SHIFTS INTO NORTHERN WI AND MAY
SPREAD ITS SNOW NORTH OF TAYLOR COUNTY. FEEL FAIRLY CONFIDENT SNOW
WILL OCCUR OVERNIGHT...BUT HAVE DECIDED TO MOVE IT NORTH WITH TIME
AND LEAVE FLURRIES SOUTH TO I-94. THE SNOW RATIOS COULD BE QUITE
HIGH WITH THIS SNOW WITH MOST OF THE SATURATED COLUMN IN THE
DENDRITE GROWTH ZONE -12 TO -18C...THUS LOW QPF COULD PRODUCE AN
INCH PRETTY EASY.
MAINLY FLURRIES SHOULD REMAIN DURING THE EARLY MORNING THURSDAY WITH
ROADS CLEANING UP FOR TRAVEL. SUN IS EXPECTED BY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 310 PM CST WED NOV 27 2013
A PERIOD OF QUIET WEATHER WITH SOME MODERATION IN TEMPERATURES
BEGINNING FRIDAY...BUT A COLD START THAT MORNING UNDER HIGH
PRESSURE AND CLEAR SKIES. IF A BIT MORE SNOW FALLS IN TAYLOR
COUNTY TONIGHT ACROSS TAYLOR COUNTY...FRIDAY MORNING COULD BE NEAR
ZERO.
NEXT WEATHER SYSTEM SHIFTS ACROSS NORTHERN GREAT LAKES FRIDAY
NIGHT AND SATURDAY WITH THE MORE FAVORABLE FORCING NORTH OF THE
AREA. MAYBE SOME CLOUDS AND FLURRIES IN TAYLOR COUNTY BUT HAVE
KEPT DRY FORECAST INTACT.
SUNDAY THROUGH WEDNESDAY...LOW CONFIDENCE IN THIS PERIOD AS THE
MODEL GUIDANCE HAS DIFFERENT EVOLUTIONS AND TIMING TO THE MAJOR
READJUSTMENT OF THE LARGE SCALE PATTERN OVER NORTH AMERICA. MAJOR
TROUGH AND COLD POOL OF AIR INVADE THE WESTERN CONUS WITH AN
ASTOUNDING -3.5 TO -4 STANDARD DEVIATION BELOW NORMAL 850 MB TEMP
IN THE WESTERN CONUS. BECAUSE OF THE SPREAD IN THE MODELS AND HOW
ENERGY EJECTS OUT OF THE TROUGH...THE FORECAST HAS SMALL
PRECIPITATION CHANCES MONDAY TO WEDNESDAY. THIS COULD BE A DRY
PERIOD SHOULD THE 27.12Z ECMWF SOLUTION OCCUR...WHICH THE 27.12Z
GFS TRENDED TOWARD...WITH MORE WEATHER LATER IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1137 AM CST WED NOV 27 2013
AN 8 TO 10K DECK AHEAD ON APPROACHING SHORT WAVE TROUGH WILL MOVE
INTO KRST AROUND 27.20Z AND KLSE AROUND 27.21Z. AS THE 285K
ISENTROPIC LIFT AND WARM AIR ADVECTION INCREASES AHEAD OF THIS
WAVE...THE CEILINGS WILL DESCEND INTO THE 3 TO 5K RANGE AFTER
28.03Z AND THEN REMAIN THERE THROUGH 28.12Z AT KRST AND 28.14Z AT
KLSE. SUBSIDENCE BEHIND A SECOND SHORT WAVE TROUGH WILL THEN CLEAR
SKIES ACROSS THE AREA.
THERE APPEARS TO BE A SMALL WINDOW FOR SOME VERY LIGHT SNOW AT
KLSE BETWEEN 28.06Z AND 28.08Z. VISIBILITIES SHOULD REMAIN ABOVE
6SM.
WINDS WILL BE BETWEEN 4 AND 8 KNOTS. THEY WILL BECOME SOUTHERLY
THIS AFTERNOON AND THEN SHIFT TO NORTHWEST BETWEEN 28.12Z AND
28.16Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1135 PM CST THU NOV 28 2013
.UPDATE...
ISSUED AT 917 PM CST THU NOV 28 2013
AN UPDATE WAS JUST SENT TO LOWER TEMPERATURES 2 OR 3 DEGREES OVER
THE NORTHERN HALF OF THE FORECAST AREA. AT 03Z OBSERVED TEMPS WERE
WITHIN A FEW DEGREES OF FORECAST MINS AT SEVERAL SITES NORTH OF I80.
LIGHT AND VARIABLE WINDS AND CLEAR SKIES THE REST OF THE NIGHT
WILL ALLOW TEMPS TO CONTINUE COOLING...REACHING THE SINGLE DIGITS
TO AROUND 10 BY SUNRISE.
&&
.SYNOPSIS...
ISSUED AT 218 PM CST THU NOV 28 2013
A WEAK SURFACE LOW MOVED EASTWARD INTO SOUTHERN LAKE MICHIGAN
DURING THE DAY ON THURSDAY WITH A COLD FRONT STRETCHING SOUTHWESTWARD
TO KSTL TO KJLN IN SOUTHWEST MISSOURI. SURFACE HIGH SAT OVER
EASTERN NORTH DAKOTA. STRATUS ALONG THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE HAS SLOWLY DISSIPATED THROUGH THE DAY. TEMPERATURES
WERE IN THE UPPER 20S IN NORTHWEST ILLINOIS TO THE LOWER 40S IN
WEST CENTRAL ILLINOIS.
A CHANGE IN THE 500 HPA PATTERN WILL OCCUR OVER
THE NEXT SEVEN DAYS AS WE GO FROM THE CURRENT NORTHWEST FLOW ALOFT
TO A MORE ZONAL FLOW WHICH WILL CONTINUE INTO EARLY NEXT WEEK.
THIS WILL RESULT IN SLOWLY MODERATING TEMPERATURES AS THE COLD AIR
OF THE LAST WEEK RETREATS NORTHWARD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE NAM/RAP BEING AN
OUTLIER WITH LOW LEVEL MOISTURE IN PLACE ACROSS THE REGION. THE
MAIN FORECAST CONCERNS WILL BE THE POTENTIAL FOR CLOUD COVER
OVERNIGHT INTO FRIDAY AS WELL AS TEMPERATURES ON FRIDAY.
HIGH PRESSURE IS FORECAST TO BUILD SOUTHEASTWARD OVERNIGHT AND BE
CENTERED ALONG THE IOWA AND ILLINOIS BORDER BY 12 UTC ON FRIDAY. AN
EXTENSIVE STRATUS DECK DEVELOPED ON THE SOUTH AND WEST SIDES OF
THE HIGH PRESSURE THIS MORNING WITH A STRONG INVERSION IN PLACE
ACROSS THE UPPER MIDWEST AND NORTHERN PLAINS. THE 12 UTC SOUNDINGS
AT KBIS AND KABR SHOWED EXTENSIVE LOW LEVEL MOISTURE IN PLACE. THE
ECMWF...GFS... AND GEM CONTINUE TO SHOW A DRIER INVERSION IN PLACE
ACROSS THE REGION OVERNIGHT WHILE THE NAM AND RAP SHOW MORE
MOISTURE IN THE LOWER LEVELS OF THE ATMOSPHERE BUT NOT TO THE
EXTENT THAT EXISTED AT KBIS AND KABR THIS MORNING. THEREFORE I AM
NOT ANTICIPATING THE FORMATION OF NEW STRATUS TONIGHT SO GOING
WITH CLEAR SKIES TONIGHT. A GOOD RADIATIONAL COOLING NIGHT AND
EXPECT TEMPERATURES TO FALL QUICKLY THIS EVENING.
HIGH PRESSURE IS FORECAST TO SHIFT EASTWARD DURING THE DAY ON
FRIDAY WITH WINDS VEERING TO THE SOUTHEAST DURING THE AFTERNOON HOURS.
850 HPA TEMPERATURES WARM FROM -4 TO -10*C TODAY TO 0 TO -4*C ON
FRIDAY. HAVE WARMED TEMPERATURES UP BY A COUPLE OF DEGREES BUT MID
LEVEL CLOUDINESS WILL BE ON THE INCREASE TOMORROW AHEAD OF ANOTHER
WAVE THAT WILL ARRIVE ON SATURDAY. THE INCREASING CLOUDS MAY HELP
TO KEEP TEMPERATURES FROM WARMING AS THEY DID TODAY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 218 PM CST THU NOV 28 2013
FRIDAY NIGHT...WEAK NORTHERN STREAM CLIPPER WILL CONTINUE MOVING TO
GREAT LAKES BY SATURDAY MORNING. OVERNIGHT LOW TEMPERATURES WILL BE
IN THE 20S.
SATURDAY AND SUNDAY...TEMPERATURES WILL RANGE NEAR OR SLIGHTLY ABOVE
NORMAL ON SATURDAY BEFORE A WEAK SURFACE TROF CROSSES THE AREA
SWITCHING THE WIND TO THE WEST NORTHWEST LATE IN THE DAY. WITH
LIMITED MOISTURE THIS TROF PASSAGE WILL BE DRY. ON SUNDAY...WEAK
COLD AIR ADVECTION BEHIND THE TROF PASSAGE WILL PRODUCE LOW
TEMPERATURES IN THE IN 20S ON SATURDAY NIGHT WITH HIGHS IN THE MID
30S ACROSS THE NORTHERN THIRD OF THE FORECAST AREA WITH HIGHS IN THE
40S OVER THE SOUTH.
MONDAY THROUGH WEDNESDAY...LATEST MEDIUM RANGE MODEL SOLUTIONS
CONTINUE TO DIVERGE BUT THERE IS OVERALL AGREEMENT IN DEVELOPING A
DEEP TROF ACROSS THE WESTERN UNITED STATES BY MID WEEK. THE ENERGETIC
SYSTEM CURRENTLY DIVING SOUTH ALONG THE WEST COAST WILL BEGIN A
PERIOD OF ACTIVE WEATHER FOR THE MIDWEST. THE 12Z GFS KEEPS THE
FORECAST AREA MAINLY DRY THROUGH TUESDAY. HOWEVER...THE 12Z ECMWF IS
FASTER AND BRINGS PRECIPITATION INTO THE REGION ON MONDAY. IN EITHER
CASE MOISTURE ADVECTION FROM THE GULF OF MEXICO AHEAD OF THE SURFACE
LOW WILL BREAK OUT PRECIPITATION EITHER MONDAY OR TUESDAY. THE
PRECIPITATION COULD FALL AS A MIXTURE OF RAIN AND SNOW.
THURSDAY AND FRIDAY...CONFIDENCE IS LOW AS MODEL SOLUTIONS SHOW
MAJOR DISCREPANCIES. THE 12Z RUN OF THE ECMWF PROGS A SURFACE
LOW TO DEVELOP OVER THE CENTRAL ROCKIES AND TRACK NORTHWEST OF IOWA
ON THURSDAY. IF THIS TRACK IS CORRECT WARM AIR ADVECTION AHEAD OF
THIS LOW WOULD PRODUCE A RAIN OR RAIN/SNOW MIX TURNING TO ALL RAIN
WITH A SNOW STORM OCCURRING OVER WESTERN IOWA AND THE NORTHERN
PLAINS. ON THE OTHER HAND THE 12Z RUN OF THE GFS TRACKS THE SURFACE
LOW FURTHER SOUTHEAST AND PROGS IT TO MOVE ACROSS MISSOURI INTO
NORTHERN ILLINOIS/INDIANA BY FRIDAY. IF THE GFS SOLUTION IS CORRECT
THERMAL PROFILES WOULD SUPPORT AN ALL SNOW EVENT LATE NEXT WEEK.
HOWEVER I MUST STRONGLY REITERATE FORECAST CONFIDENCE IS LOW.&&
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1128 PM CST THU NOV 28 2013
VFR CONDITIONS WILL PREVAIL THROUGH FRIDAY EVENING. CLEAR SKIES
AND LIGHT WINDS WILL REMAIN OVER THE AREA TONIGHT AS HIGH PRESSURE
DRIFTS EAST THROUGH THE REGION. FRIDAY...WITH THE HIGH TO THE
EAST...WINDS WILL PICKUP OUT OF THE SOUTHEAST WITH HIGH CLOUDS
OVER SPREADING THE AREA DURING THE AFTERNOON AND EVENING.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...DLF
SYNOPSIS...COUSINS
SHORT TERM...COUSINS
LONG TERM...KUHL
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
401 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY.
BLDG HIGH PRES WL SPPRT LTR IN THE DAY AND FOR THE RMNDR OF THE TAF
PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
108 AM CST FRI NOV 29 2013
.UPDATE...
ISSUED AT 100 AM CST FRI NOV 29 2013
DECREASED CLOUDS A BIT COMPARED TO WHAT WAS IN THE FORECAST FOR
THE REST OF THE OVERNIGHT. WITH WARM AIR ADVECTION OVERNIGHT JUST
OFF THE SURFACE...AHEAD OF THE SURFACE WARM FRONT...THERE IS A
CHANCE THAT LOWER CLOUDS COULD FORM...AND SOME MODEL GUIDANCE
SHOWS THIS. HOWEVER...THE TREND OVER THE PAST FEW HOURS HAS BEEN
FOR THE LOW CLOUDS TO DECREASE...NOT INCREASE.
MID CLOUD IS ALSO WORKING ITS WAY THROUGH NORTHEAST MONTANA AND
INTO NORTHWEST NORTH DAKOTA. BASICALLY VARIABLE CLOUDS
OVERNIGHT...PARTLY CLOUDY AND TIMES...MOSTLY CLOUDY AT OTHER
TIMES.
BASED ON TEMPERATURE TRENDS...AND WITH SOUTHEAST SURFACE WIND 5 TO
15 MPH...MAYBE MORE LIKE 10 TO 15 MPH...WILL NOT EXPECT
TEMPERATURES TO FALL MUCH FROM WHERE THEY ARE AS OF THIS
WRITING. WIND WILL MAKE IT FEEL 5 TO 10 DEGREES LOWER THAN WHAT
THE THERMOMETER SHOWS.
NO CHANGES TO THE REST OF THE SHORT TERM FOR NOW.
UPDATE ISSUED AT 851 PM CST THU NOV 28 2013
CLOUDS AND TEMPERATURES CONTINUE TO BE THE MAIN ISSUES TONIGHT.
COOL HIGH PRESSURE ACROSS MINNESOTA WITH A WARM FRONTAL BOUNDARY
ACROSS MONTANA. THE TREND HAS BEEN CLEARING SKIES BUT LATEST
SATELLITE PICTURES SUGGEST CLOUDS MAYBE REFORMING ACROSS CENTRAL
NORTH DAKOTA NORTH OF LAKE SAKAKAWEA. NOW WILL BE TRENDING THE
CLOUDS BACK INTO THE PICTURE TONIGHT. ALSO TEMPERATURES MAY HIT
THEIR LOWS LATE THIS EVENING OR EARLY AFTER MIDNIGHT THEN BECOME
STEADY OR RISE A BIT BY MORNING...ESPECIALLY JAMES RIVER VALLEY
NORTH TO THE DEVILS LAKE BASIN. DO NOT SEE ANY PRECIP IN THE
FORECAST FOR TONIGHT AS THE FLURRIES FROM THURSDAY AFTERNOON HAVE
ENDED.
UPDATE ISSUED AT 541 PM CST THU NOV 28 2013
AT 5 PM CST...SURFACE HIGH PRESSURE EXTENDED ACROSS THE EASTERN
DAKOTAS. A SURFACE TROUGH AND ASSOCIATED WARM FRONT EXTENDED
THROUGH CENTRAL MONTANA. THE THIN LAYER OF STRATUS HAS ERODED
IN WEAK LOW LEVEL WARM ADVECTION...LEAVING NARROW BANDS OF CLOUDS
ACROSS CENTRAL NORTH DAKOTA WITH THE WEST GENERALLY MOSTLY CLEAR.
CURRENT THINKING IS THE CLOUDS WILL EVENTUALLY BACK FILL IN WITH
SHALLOW COOL AIR IN PLACE AS THE WARM FRONT MOVES EAST. SOME
UNCERTAINTY HERE ALSO...AS LOW LEVEL WARM ADVECTION AT H850 MAY
SUPPRESS CLOUDS LATER TONIGHT. BUT WENT WITH AN INCREASE IN CLOUDS
THROUGH MIDNIGHT....THEN CLOUDY AFTER MIDNIGHT. CURRENT
TEMPERATURES AND WINDS SEEM OK FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE SKY COVER
TONIGHT AND IMPACT ON TEMPERATURES.
PORTIONS OF THE STRATUS DECK HAVE ERODED ACROSS THE FORECAST AREA
THIS AFTERNOON. RAP 925MB RELATIVE HUMIDITY HAS THIS MODELED
RELATIVELY WELL AND SUGGEST THAT STRATUS SHOULD FILL BACK IN THIS
EVENING AND OVERNIGHT. TEMPERATURES WILL LIKELY DROP QUICKLY THIS
EVENING IN CLOUD FREE AREAS...BEFORE THE STRONGER SE WINDS
DEVELOP. THE STRONGER GRADIENT WILL BE LOCATED OVER THE WEST AND
HAVE KEPT OVERNIGHT LOWS RELATIVELY MILD...IN THE TEENS TO LOWER
20S. EAST/NORTHEAST PORTIONS OF THE FORECAST AREA...FROM THE
TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY...SHOULD BE ABLE
TO GET INTO THE SINGLE DIGITS. HOURLY TRENDS WILL LIKELY NEED TO
BE UPDATED THIS EVENING.
ON FRIDAY...STRONGER WARM AIR ADVECTION WILL KICK IN...WITH HIGHS
IN THE MID 20S NORTHEAST TO LOWER 40S SOUTHWEST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 306 PM CST THU NOV 28 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE RETURN OF ARCTIC AIR
AND THE POTENTIAL FOR WIDESPREAD ACCUMULATING SNOW NEXT WEEK.
THE 12 UTC GUIDANCE SUITE IS IN GOOD AGREEMENT ON A SIGNIFICANT
UPPER LEVEL LOW COMING ONSHORE TO THE PACIFIC NORTHWEST ON MONDAY.
THEREAFTER...UNCERTAINTY INCREASES IN REGARDS TO THE EVOLUTION AND
PROPAGATION OF THIS LOW ACROSS THE INTERMOUNTAIN WEST AND
POTENTIALLY INTO THE NORTHERN PLAINS LATE TUESDAY AND INTO
WEDNESDAY. THE 12 UTC ECMWF CONTINUES THE TREND OF ITS PREVIOUS
RUNS OVER THE PAST 24 HOURS OF THE DEEPEST LOW YIELDING
SIGNIFICANT QPF AND SNOW ACROSS THE NORTHERN PLAINS TUESDAY INTO
WEDNESDAY. THE 12 UTC GFS HAS TRENDED MORE TOWARDS THE
ECMWF...HOWEVER...IS NOT AS DEEP WITH LESSER QPF...MUCH LIKE THE
12 UTC GEM. THE ECMWF HAS BEEN THE MOST CONSISTENT AND IS
SUPPORTED BY THE GEFS MEAN...AND FAVORED BY WPC. THUS...WILL
CONTINUE TO MONITOR THE POTENTIAL FOR ACCUMULATING SNOW NEXT WEEK.
NO MATTER THE MODEL...ARCTIC AIR IS FORECAST TO OVERTAKE THE
NORTHERN PLAINS ONCE AGAIN TUESDAY THROUGH THE END OF NEXT WEEK
WITH A PATTERN SHIFT TO BROAD WESTERN AND CENTRAL CONUS UPPER
LEVEL TROUGHING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT) ISSUED AT
100 AM CST FRI NOV 29 2013
THE FIRST HALF OF THIS TAF FORECAST PERIOD IS COMPLICATED BECAUSE
OF UNCERTAINTY CONCERNING THE CEILING FORECAST.
THERE HAVE BEEN PATCHES OF MVFR CIGS ALONG THE MONTANA BORDER...
MOVING NORTHWEST IN SOUTHEAST SURFACE FLOW...AND MVFR CIGS FROM
SOUTHEAST OF KMOT THROUGH THE KJMS AREA. THE TREND HAS BEEN FOR
THEM TO BE DECREASING RATHER THAN INCREASING IN COVERAGE.
HOWEVER...WITH SHALLOW COLD AIR IN PLACE...A SURFACE WARM FRONT IN
EASTERN MONTANA...AND WARM AIR ADVECTION JUST OFF THE DECK...WITH
AN INVERSION EXPECTED OVER MOST OF THE AREA BY DAYBREAK FRIDAY...
THE EXPECTATION THAT MVFR CIGS WILL REDEVELOP IS SUPPORTED. TIMING
AND THE EXTENT OF THE CLOUDS ARE UNCERTAIN. CURRENT TAFS USED
TEMPO GROUPS TO ACCOUNT FOR THE REFORMATION OF LOWER CLOUDS.
CONDITIONS WILL IMPROVE TO VFR AGAIN FRIDAY AFTER 16-18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
LONG TERM...AYD
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 PM CST THU NOV 28 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
AT 3 PM...A LAKE INDUCED VORTICITY WAS LOCATED OVER THE APOSTLE
ISLANDS IN WESTERN LAKE SUPERIOR. MEANWHILE A SURFACE LOW WAS
LOCATED OVER EASTERN UPPER MICHIGAN. THIS LOW WAS PRODUCING WEAK
CYCLONIC FLOW ACROSS ACROSS WISCONSIN AND EAST CENTRAL MINNESOTA.
THIS CYCLONIC FLOW ALONG WITH STEEP 950-900 MB LAPSE RATES
/ASSOCIATED WITH A THERMAL TROUGH LOCATED FROM NORTHERN MINNESOTA
SOUTHEAST INTO EASTERN WISCONSIN/ IS HELPING MAINTAIN THESE
CLOUDS. THE 28.19Z RAP HAS A VERY GOOD HANDLE ON THESE CLOUDS AND
THEY SHOW THAT THEY WILL CONTINUE TO MOVE SOUTHEAST ACROSS MAINLY
OUR WISCONSIN COUNTIES AND THEN QUICKLY DISSIPATES THEM BETWEEN
28.01Z AND 28.03Z AS THE FLOW STARTS TO BECOME ANTICYCLONIC AND
THE 950-900 MB LAPSE RATES DECREASE.
FROM LATE TONIGHT INTO FRIDAY...THE 28.12Z MODELS CONTINUE TO
SHOW THAT WEAK WARM AIR ADVECTION WILL DEVELOP ABOVE 600 MB AS A
WEAK SHORT WAVE TROUGH APPROACHES THE REGION FROM THE CENTRAL
PLAINS. THIS WILL RESULT IN SOME MID TO HIGH CLOUDS ACROSS THE
AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 325 PM CST THU NOV 28 2013
ON FRIDAY NIGHT...THE 28.12Z MODELS CONTINUE TO SHOW THAT A STRONG
SHORT WAVE TROUGH WILL MOVE SOUTHEAST ACROSS SOUTHWEST ONTARIO.
MUCH OF THE PV ADVECTION ASSOCIATED WITH THIS SYSTEM STAYS WILL
NORTH OF THE FORECAST AREA. THERE IS WEAK TO MODERATE 285 TO 300K
ISENTROPIC LIFT ACROSS NORTHERN AND EASTERN WISCONSIN. THIS LOWERS
THE CONDENSATION PRESSURE DEFICITS TO LESS 40 MB. MEANWHILE AT THE
285 AND 290K ISENTROPIC SURFACES YOU STILL NEED 100 TO 200 MB
OF LIFT FOR SATURATION. AS A RESULT...IT IS NOT LOOKING PROMISING
FOR ANY PRECIPITATION ACROSS TAYLOR AND NORTHERN CLARK COUNTY IN
NORTH CENTRAL WISCONSIN. HOWEVER WITH THE ECMWF...GEM...AND NAM
STILL INDICATING A POSSIBILITY. JUST KEPT A SLIGHT CHANCE /LESS
THAN 20 PERCENT/ ACROSS THIS AREA. BUFKIT SOUNDINGS CONTINUE TO
SHOW NO ICE...SO IF PRECIPITATION DOES INDEED OCCURS IT WOULD BE
IN THE FORM OF FREEZING DRIZZLE.
ON SATURDAY NIGHT...WEAK TO MODERATE WARM AIR ADVECTION AND STRONG
290 TO 300K ISENTROPIC LIFT DEVELOP ACROSS THE AREA AS A STRONG
SHORT WAVE TROUGH MOVES ACROSS THE REGION. THE 290-300K ISENTROPIC
CONDENSATION PRESSURE DEFICITS DROP TO LESS THAN 30 MB...SO WE
WILL LIKELY SEE CLOUDS WITH THIS WAVE. HOWEVER...THE 285K
CONDENSATION DEFICITS REMAIN IN THE 100 TO 200 MB RANGE...SO NOT
EXPECTING ANY PRECIPITATION WITH THIS WAVE.
FROM SUNDAY NIGHT INTO MONDAY...THE MODELS CONTINUE TO STRUGGLE
WITH THE TIMING OF A SHORT WAVE TROUGH COMING OUT AHEAD OF THE
DEVELOPING LONG WAVE TROUGH IN THE WESTERN UNITED STATE. BOTH THE
GEM AND ECMWF BRING A WAVE AHEAD OF THIS SYSTEM. MEANWHILE THE GFS
DOES NOT. AS AS RESULT...THE GEM AND ECMWF PRODUCES SOME LIGHT
PRECIPITATION ACROSS THE AREA. MEANWHILE THE GFS KEEPS THE AREA
DRY. SINCE THE MODELS HAVE BEEN CONSISTENT...JUST STAYED WITH THE
SLIGHT CHANCES THAT THE ALL BLEND PROVIDED.
FROM MONDAY NIGHT THROUGH THURSDAY...THE MODELS CONTINUE TO
STRUGGLE WITH THE EVOLUTION OF A LONG WAVE TROUGH OVER THE WESTERN
UNITED STATES. DUE TO THIS...THERE HAS BEEN A VARIETY OF DIFFERENT
LOW PRESSURE TRACKS FROM THE NORTHERN PLAINS EAST INTO THE GREAT
LAKES. THIS SYSTEM HAS THE POTENTIAL OF PRODUCING A WINTER STORM
SOMEWHERE ACROSS THE REGION...BUT WHERE IS VERY UNCERTAIN...SO
JUST STAYED WITH THE ALL BLEND FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 1125 PM CST THU NOV 28 2013
CLOUDS HAVE FINALLY DIMINISHED...AND EXPECT SKC/SCT CONDITIONS FOR THE
REST OF THE NIGHTTIME HOURS WITH LIGHT TO VRB WINDS. WINDS WILL
INCREASE AND SHIFT TO THE SOUTH/SOUTHEAST A FEW HOURS AFTER DAYBREAK
FRIDAY AS HIGH PRESSURE EXITS OVER THE EASTERN GREAT LAKES. SHOULD
SEE SOME HIGH/MID LEVEL CLOUDS BY THIS TIME...MOSTLY IN THE 150-250
KFT RANGE.
A COUPLE FORECAST CONCERNS FOR FRIDAY NIGHT. FIRST IS THE POTENTIAL
FOR MVFR CIGS AT KLSE. NAM SUGGESTS LOW LEVEL MOISTURE WILL BE ON
THE INCREASE IN THE EVENING...LIKELY RESULTING IN A 1500-2500 FT
DECK. THE GFS IS DRIER IN THE LOW LAYERS...AND STAYS VFR. THERE WAS
A LARGE SWATH OF MVFR CIGS ACROSS THE DAKOTAS THU MORNING...IN A
REGION OF GOOD LOW LEVEL ISENTROPIC UPGLIDE...WHICH WILL BE SHIFTING
ACROSS THE LOCAL AREA FRIDAY NIGHT. HOWEVER...THE PRESSURE GRADIENT
WAS ALSO WEEK ACROSS THE DAKOTAS...WHILE LOCALLY THE PRESSURE
GRADIENT WILL STAY RELATIVELY TIGHT...WITH WINDS AROUND 10 KTS.
STILL...WITH INCREASING MOISTURE/TRANSPORT UNDER AN
INVERSION...WOULD SEEM TO BE A DECENT SETUP FOR SOME LOW STRATUS
FORMATION. CONFIDENCE SHAKY AT THE MOMENT...BUT ENOUGH TO GO ON TO
ADD A MENTION FOR KLSE. THE OTHER CONCERN IS THE POTENTIAL FOR LLWS
FRIDAY NIGHT. BUFKIT SOUNDINGS SUGGESTING AROUND 40 KTS BY 2 KFT
FRIDAY EVENING...AND SFC WINDS DEPENDING...LLWS CRITERIA COULD BE
MET. WILL LEAVE OUT OF THE FORECAST FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
915 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY CHANGES NEEDED FOR THE MID MORNING UPDATE WERE TWEAKS TO HOURLY
TRENDS OF CLDS AND TEMPS.
PREVIOUS...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
632 AM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY CHANGES NEEDED FOR THE NR DAWN UPDATE WERE TWEAKS TO HOURLY
TRENDS OF CLDS AND TEMPS.
PREVIOUS...
COLD AIR REMAINS OVER THE AREA TODAY. LATEST MODEL SOUNDINGS AND
HIRES SOLUTIONS ARE SHOWING CLOUDS DECREASING THIS MORNING FROM
SOUTHWEST TO NORTHEAST...AS ATMOSPHERE TEMPORALLY DRIES OUT.
HOWEVER ANOTHER PUSH OF COLDER AIR THIS AFTERNOON WILL PROMOTE
CLOUD REDEVELOPMENT.
TEMPS AGAIN...WELL BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WAA WILL BE ON THE INCREASE TONIGHT AND SATURDAY WHICH WILL
RESULT IN A WARMING TREND IN TEMPERATURES SATURDAY. CLOUD
COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS SATURDAY IN
ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/22
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
339 PM EST FRI NOV 29 2013
.SYNOPSIS...
A GRADUAL WARMING TREND THE COMING DAYS BACK TO NORMAL LEVELS. THE
NEXT FRONT CROSSES SUNDAY...WITH ANY RAIN OR SNOW CONFINE TO
AREAS ALONG AND NORTH OF INTERSTATE 80. LOTS OF CLOUDS ARE
FORECASTED FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AFTER A BRIEF CLEARING...MID LEVEL CLOUD COVERAGE WILL INCREASE
THROUGH THE AFTERNOON AS FLOW ALOFT TURNS NORTHWEST BEHIND THE
SHORTWAVE THAT PASSED OVER THIS MORNING. HAVE ADJUSTED
TEMPERATURES SLIGHTLY UPWARDS BASED ON LATEST OBS
TRENDS...HOWEVER...DAYTIME MAX HIGHS ARE STILL EXPECTED TO BE
APPROXIMATELY 10 DEGREES BELOW CLIMO NORMS TODAY. TONIGHT WINDS
WILL TURN SOUTHWESTERLY...AND THE INCREASED WAA WILL INITIATE A
WARMING TREND IN TEMPERATURES THROUGH THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
HIGH PRESSURE CONTINUES TO RETREAT INTO NEW ENGLAND SAT
NGT...HOWEVER RETURN FLOW ALLOWS FOR A WARMER NIGHT WITH SWRLY
WINDS OUT AHEAD. OVERALL MODELS ARE IN GOOD AGREEMENT WITH THE
NEXT WEATHER SYSTEM SUN - MON NIGHT. BOTH DEPICT A FULL LATITUDE
TROUGH ACROSS THE EASTERN CONUS...BUT LITTLE IN THE WAY OF ANY
BAROCLINICTY AT THE SFC. ALL OF THE ENERGY RESIDES WITH THE
CYCLONE TRACKING OFF THE ERN SEABOARD. UPSTAIRS THERE ARE PASSING
S/W TROUGHS DURING THIS PERIOD THAT WILL YIELD LIGHT QPF. H5
TROUGH BECOMES NEGATIVELY TILED AS IT SWEEPS THROUGH MONDAY
NIGHT...BUT WITH THE LACK OF AGEOSTROPHIC DIVERGENCE AT H2 AND
5-10KTS OF LLVL CONV...ONLY LIGHT PCPN EXPECTED. CONTINUED THEME
OF HIGHLIGHTING AREAS ALONG AND N OF I-80 FOR MEASURABLE QPF
SUNDAY INTO SUNDAY NIGHT. THERMAL PROFILES ILLUSTRATE POTENTIAL
FOR A RA/SN MIX. HIGH PROBABILITY OF ALL SNOW THE CLOSER TO LAKE
ERIE AS COLUMN IS COLDER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HIGHLIGHTS:
- SLOW WARMING TREND CONTINUES
- ABOVE NORMAL TEMPS BY THE END OF NEXT WEEK
- STRONG LOW PRESSURE PASSES THUR - FRI
FORECAST CONFIDENCE IS ABOVE AVERAGE FOR THE FIRST TWO DAYS OF
THE LONG RANGE THEN LOWERS. TRANSITORY MID LVL RIDGE CROSSES MID WEEK
ALLOWING TEMPS TO WARM INTO THE 40S MELTING ANY LEFTOVER SNOW
PACK.
LATTER PART OF THE WEEK BOTH OPERATIONAL RUNS OF ECMWF AND GFS
SHOW A GOOD SHOT AT RAIN WITH LOW PRESSURE TRAVELING ALONG THE
MTNS. THIS TRACK WHICH IS FURTHER SUPPORTED BY THEIR RESPECTIVE
ENSEMBLE MEANS PLACE US ON THE WARM SIDE OF THE SYSTEM. THE
CHALLENGE IS TIMING AND IF A SECOND WAVE RIDES ALONG THE BOUNDARY
AS MID LVL FLOW BECOMES PARALLEL TO THE FRONT. STRONG ISENTROPIC
UPGLIDE ON 290-300K WITH WINDS INTERESTING THETA SFCS AT RIGHT
ANGLES. SPECIFIC HUMIDITY VALUES PUSH 4-5 GKG-1 WHICH IS ABOVE
NORMAL THIS TIME OF YEAR. GEFS PLUME DIAGRAMS SHOW POTENTIAL FOR
0.50 TO 1.25 INCHES OF RAIN WITH VERY LITTLE SNOW ON THE BACK
SIDE. THIS IS NOTHING THAT WOULD LEAD TO HIGH WATER DUE TO ALL THE
SNOW HAS MELTED AND WE WILL BE DRY THE DAYS LEADING UP.
A LOT OF SPREAD EXISTS AFTER THE COLD FRONT COMES THROUGH. ECMWF IS
STRONGER WITH UPSTREAM RIDGE AXIS THEREBY HAVING ANOTHER WAVE OF
LOW PRESSURE PASSING FRIDAY W OF THE MTNS. GFS IS WEAKER WITH RIDGE
THUS HAVING LOW PRESSURE PASS TO OUR SE. GIVEN GUIDANCE SPREAD
FROM MOS IS WELL INTO THE 60S ROLLED WITH LKLY POPS NEXT THUR AND
FRI.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
NO WIDESPREAD AREAS OF IFR WEATHER EXPECTED. BRIEF MVFR
RESTRICTIONS ARE POSSIBLE WITH THE NEXT WEATHER SYSTEM SUNDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
SYNOPSIS...98
NEAR TERM...88
SHORT TERM...98
LONG TERM...98
AVIATION...88/98
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1226 PM EST FRI NOV 29 2013
.SYNOPSIS...
ANOTHER COLD DAY...BUT TEMPERATURES WILL BEGIN TO MODERATE
SATURDAY. THE NEXT COLD FRONT CROSSES ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AFTER A BRIEF CLEARING...MID LEVEL CLOUD COVERAGE WILL INCREASE
THROUGH THE AFTERNOON AS FLOW ALOFT TURNS NORTHWEST BEHIND THE
SHORTWAVE THAT PASSED OVER THIS MORNING. HAVE ADJUSTED
TEMPERATURES SLIGHTLY UPWARDS BASED ON LATEST OBS
TRENDS...HOWEVER...DAYTIME MAX HIGHS ARE STILL EXPECTED TO BE
APPROXIMATELY 10 DEGREES BELOW CLIMO NORMS TODAY. TONIGHT WINDS
WILL TURN SOUTHWESTERLY...AND THE INCREASED WAA WILL INITIATE A
WARMING TREND IN TEMPERATURES THROUGH THE REMAINDER OF THE WEEKEND.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
CLOUD COVERAGE WILL GRADUALLY INCREASE IN THE UPPER LEVELS
SATURDAY IN ADVANCE OF A WEAK SHORTWAVE TO BRUSH THE AREA ON
SUNDAY.
WEAK COLD FRONT ATTEMPTS TO CROSS THE AREA LATE SUNDAY. FRONT HAS
ALMOST NO UPPER LEVEL SUPPORT AND MOISTURE WILL REMAIN TO THE
NORTH OF THE BOUNDARY. HAVE KEPT POPS ACROSS THE NORTH SUNDAY IN
THE AREA OF DEEPEST MOISTURE. TEMPS ON SUNDAY VERY CLOSE TO
SATURDAY`S EXPECTED READINGS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WILL CONTINUE WITH A DRY LONG TERM...ALTHOUGH UNCERTAINTIES ARISE
TUESDAY IN RELATION TO THE AFFECT FROM THE PASSAGE OF A WEAK WARM
FRONT.
TEMPS BELOW NORMAL TO BEGIN THE WORK WEEK...WITH SOME MODERATION
BY THE END OF THE PERIOD.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
STRATOCU ARE EXPD TO CONT TO PLAGUE UPR OH VALLEY PORTS TDA AS A
WEAK FRONT SAGS ACRS THE REGION IN THE WAKE OF AN EXITING UPR
DISTURBANCE. GIVEN LOW CONVECTIVE THRESHOLDS UNDR A LOWERING
INVERSION...HAVE ELECTED TO FOLLOW A MORE PESSIMISTIC HRRR PROGNOSIS
OF MVFR CIGS FOR MUCH OF THE DAY FOR PORTS N OF I 70.
BLDG HIGH PRES WL SPPRT VFR LTR IN THE DAY AND FOR THE RMNDR OF
THE TAF PD.
.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
THE NXT CHC FOR RESTRICTIONS WL COME WITH A SUNDAY CDFNT...ALTHOUGH
PCPN MAY BE SPARSE.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$