Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/27/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
133 AM MST MON NOV 25 2013
.UPDATE...
ISSUED AT 129 AM MST MON NOV 25 2013
ISSUED WINTER WEATHER ADVISORY FOR SOUTHERN I-25 CORRIDOR AS BAND
OF VERY HEAVY SNOW CONTINUES ALONG AND JUST WEST OF THE
INTERSTATE. HAD HOPED ONSET OF NORTH WINDS WOULD BOOST TEMPS ABOVE
FREEZING AND LIMIT ACCUMS...BUT LATEST OBS HAVE FALLEN BACK
SLIGHTLY AS HEAVIER PRECIP DRIVES TEMPS DOWNWARD. HAVE ALREADY
RECEIVED REPORTS OF 6 INCHES AROUND WALSENBURG. OTHER CHANGE TO
FORECAST WAS TO EXTEND ADVISORY UNTIL 16Z FOR THE WETS AND
SOUTHERN SANGRES AS SNOWFALL WILL BE SLIGHTLY SLOWER TO END.
UPDATE ISSUED AT 611 PM MST SUN NOV 24 2013
UPDATED SNOW GRIDS TO INCREASE AMOUNTS. BAND HAS BEEN PRODUCING A
QUICK 1 TO 4 INCHES ACROSS EL PASO AND PUEBLO COUNTIES. WITH
TRAJECTORY OF SNOW ENHANCEMENT HEADED TOWARDS THE WET
MOUNTAINS...ADDED THE LOWER ELEVATIONS OF THE WETS AND THE LOWER
ELEVATIONS OF THE SANGRES TO THE WINTER WEATHER ADVISORY. HAVE AN
SPS OUT FOR EL PASO AND PUEBLO COUNTIES FOR NOW. ITS POSSIBLE THAT
THESE AREAS MAY NEED TO BE UPGRADED TO AN ADVISORY...BUT THE VAST SPATIAL
VARIABILITY BETWEEN THE HEAVY SNOW AND WHERE THERE IS NO SNOW
ACROSS THESE ZONES MAKES THIS A LESS FAVORABLE OPTION FOR
NOW...BUT WILL CONTINUE TO MONITOR AND REASSESS AS NEEDED. -KT
UPDATE ISSUED AT 459 PM MST SUN NOV 24 2013
QUICK UPDATE TO BUMP UP POPS ACROSS EL PASO AND NORTHWEST PUEBLO
COUNTIES WHERE DEFORMATION BAND HAS SET UP. GETTING REPORTS OF MODERATE
SNOW WITHIN THIS BAND AND SUSPECT A QUICK INCH OR TWO WILL BE
POSSIBLE WITHIN THE NEXT HOUR OR TWO. BASED ON SHORT RANGE HIGH RES
MODELS...FOCUS FOR HEAVIER SNOWFALL WILL SHIFT INTO THE NORTHEAST
FACING SLOPES OF THE SOUTHEAST MOUNTAINS AND FREMONT COUNTY AS THE
EVENING PROGRESSES. HOWEVER MODELS ARE NOT RESOLVING THE CURRENT
SNOW BAND VERY WELL...SO EXPECT A HIGHLY EVOLVING FORECAST TONIGHT
AS THESE DETAILS GET RESOLVED. FOR NOW...HAVE BUMPED UP POPS INTO
THE LIKELY CATEGORY FOR EL PASO...FREMONT...AND WESTERN PUEBLO
COUNTIES THROUGH 06Z. IF BAND STALLS OVER ANY PARTICULAR
AREA...SOME LOCAL ACCUMULATIONS OF UP TO 4 INCHES WILL BE POSSIBLE
OVER THE LOWER ELEVATIONS. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
...SNOW WINDING DOWN ON MONDAY...
UPPER LOW IS NOW NOW MOVING EASTWARD ALONG THE CO NM BORDER. COLDER CLOUD
TOPS HAVE SHIFTED TO THE NE PORTION OF CO...WHERE SEVERAL BANDS OF
SNOW ARE ROTATING NORTHWESTWARD ALONG THE NRN I-25 CORRIDOR. THE LOW HAS
DEFINITELY TAKEN A MORE NRN TRACK AS THE NAM AND ESPECIALLY THE
ECMWF HAD FORECAST IT TO DO. HOWEVER...NOT A LOT OF MOISTURE LEFT
WITH THE SYSTEM...AND ACCUMS TONIGHT INTO MON MORNING PROBABLY WILL
NOT BE ALL THAT IMPRESSIVE. MAIN FOCUS FOR HEAVIER ACCUMS WILL BE
DUE TO N-NE WINDS INCREASING TONIGHT AS THE LOW CONTINUES TO MOVE
AWAY. LATEST RUC SHOWING H7 WINDS INCREASING TO 30-40 KTS AFTER
ABOUT 04Z TONIGHT. THIS WILL LEAD TO SOME DECENT OROGRAPHIC ACCUMS
OVER THE HIGHER ELEVATIONS OF THE ERN MT RANGES OVERNIGHT...AND
FAVORED SPOTS LIKE CUCHARA COULD SEE SOME RESPECTABLE SNOWFALL.
LATEST HI RES MODELS REALLY SHOWING THIS POTENTIAL OVER THE WETS AND
NRN SANGRES...SO WILL ADD THE WETS TO THE CURRENT SUITE OF
ADVISORIES WE HAVE OUT THROUGH 12Z MONDAY. ELSEWHERE...BEST BET OF
SNOW OVER THE PLAINS WILL BE ALONG AND WEST OF I-25...AND ESPECIALLY
SOUTH OF HIGHWAY 50. COULD SEE SOME LIGHT ACCUMS OVER THE HIGHER
TRRN BUT NOT EXPECTING ANYTHING SIGNIFICANT. INHERITED LOW POPS FOR
THE PLAINS STILL LOOK ON TARGET SO HAVE NOT MADE ANY EXTENSIVE
CHANGES THERE.
SHOULD SEE SNOW TAPER OFF FROM N TO S ESPECIALLY AFTER MID-MORNING
ON MONDAY. JUST A FEW LINGERING SHOWERS OVER THE SRN MTS AND FAR
SERN PLAINS BY MON AFTERNOON. BREEZY CONDITIONS WILL PERSIST IN THE
WAKE OF THE LOW...ESPECIALLY OVER BACA COUNTY WHICH COULD SEE SOME
GUSTS IN THE 30-40 KT RANGE FOR THE LATE MORNING TO EARLY AFTERNOON
PERIOD. TEMPS ALOFT WILL ACTUALLY BE FALLING SIGNIFICANTLY THROUGH
MONDAY MORNING...DOWN TO AROUND MINUS 7 OR 8 C AT H7...BUT WITH GOOD
MIXING IN THE LOW TO MID LEVELS...SHOULD SEE TEMPS TOP OUT HIGHER
THAN THE TEMPS THIS AFTERNOON. HAVE CUT BACK TEMPS A BIT BELOW
GUIDANCE HOWEVER...SINCE EVEN WITH GOOD ADIABATIC MIXING THE TEMPS
ALOFT WILL PROBABLY ONLY SUPPORT 40 DEGREES OR SO AT BEST BY THE
AFTERNOON. SO...IT WILL BE A RAW DAY DESPITE THE LOWERED POPS.
ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
MONDAY NIGHT...UPPER LOW OVER WEST TEXAS FORECAST BY MODELS TO SLIDE
SOUTHEAST...BUT SOME MOISTURE IN NORTHERLY FLOW ALOFT WILL PERSIST
THROUGH PART OF THE NIGHT. INHERITED ISOLATED POPS AT MOST OVER THE
EASTERN MOUNTAINS THROUGH MIDNIGHT...AND THAT LOOKS GOOD. SNOW
ACCUMULATIONS WILL BE WELL UNDER AN INCH. LOW TEMPERATURES WILL BE
IN THE LOWER SINGLE DIGITS ACROSS THE SAN LUIS VALLEY...WITH SNOW
COVER AND RADIATIONAL COOLING. ELSEWHERE...TEMPERATURES SHOULD DIP
INTO THE TEENS ACROSS THE PLAINS AND OTHER HIGH VALLEYS...WITH
SINGLE DIGITS ACROSS THE HIGHEST ELEVATIONS.
FOR THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND...THE WEATHER
LOOKS TO BE FAIRLY TRANQUIL...AS AN UPPER LEVEL RIDGE GETS
ESTABLISHED OVER THE GREAT BASIN AND ROCKIES. A WEAK FRONT MAY
BRIEFLY AFFECT THE EASTERN PLAIN THANKSGIVING DAY...BUT WITH NO
PRECIPITATION. A COUPLE MORE SHORTWAVES IN THE NORTHERN
STREAM...WILL BRING SOME CLOUDS...WITH THE SECOND ONE...DURING THE
WEEKEND...BRINGING A CHANCE FOR SOME HIGHER ELEVATION SNOW SHOWERS.
-TLM-
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1030 PM MST SUN NOV 24 2013
THE UPPER LOW TRACKING ACROSS NORTHERN NM WAS CONTINUING TO DRAW
MOISTURE AND SFC FLOW OUT OF THE N-NE. SNOWFALL BLOSSOMED UNDER
THIS FLOW AROUND 4 PM THIS EVE AND HAS CONTINUED THROUGHOUT THE
NIGHT...WITH THE HEAVIEST BAND INITIALLY OVER SOUTHERN EL PASO
COUNTY GRADUALLY SAGGING TO THE SOUTH. HEAVIEST HIT AREAS HAVE
BEEN THE WET MT VALLEY...EASTERN MTS...AND LOCALIZED AREAS ON THE
BACKSIDE OF THE SANGRES WHERE SNOW HAS SEEMINGLY SPILLED OVER THE
RIDGE. THE HEAVIER SNOWFALL HAS NOW DROPPED SOUTH...WHERE IFR TO
LIFR CONDITIONS ARE AFFECTING KALS AND KTAD. FURTHER NORTH...KPUB
REPORTED MVFR TO IFR CONDITIONS...AND KCOS HAS NOW CLEARED OUT OF
THE SNOW WITH VFR CONDITIONS.
THE UPPER LOW WILL CONTINUE EAST OVERNIGHT AND THROUGH
TOMORROW...AND SNOW IS EXPECTED TO DIMINISH OVERNIGHT ACROSS THE
SOUTHERN TIER BETWEEN 08Z AND 10Z. STRONG AND GUSTY NORTHERLY
WINDS WILL SETTLE IN ACROSS THE AREA ON THE BACK SIDE OF THE
DEPARTING LOW...LASTING UNTIL AROUND 15Z. MOORE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ060-066-072-073.
WINTER STORM WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR
COZ068.
WINTER WEATHER ADVISORY UNTIL 9 AM MST THIS MORNING FOR COZ074-
075-079-080-087-088.
&&
$$
UPDATE...PETERSEN
SHORT TERM...ROSE
LONG TERM...TM
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1041 PM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 611 PM MST SUN NOV 24 2013
UPDATED SNOW GRIDS TO INCREASE AMOUNTS. BAND HAS BEEN PRODUCING A
QUICK 1 TO 4 INCHES ACROSS EL PASO AND PUEBLO COUNTIES. WITH
TRAJECTORY OF SNOW ENHANCEMENT HEADED TOWARDS THE WET
MOUNTAINS...ADDED THE LOWER ELEVATIONS OF THE WETS AND THE LOWER
ELEVATIONS OF THE SANGRES TO THE WINTER WEATHER ADVISORY. HAVE AN
SPS OUT FOR EL PASO AND PUEBLO COUNTIES FOR NOW. ITS POSSIBLE THAT
THESE AREAS MAY NEED TO BE UPGRADED TO AN ADVISORY...BUT THE VAST SPATIAL
VARIABILITY BETWEEN THE HEAVY SNOW AND WHERE THERE IS NO SNOW
ACROSS THESE ZONES MAKES THIS A LESS FAVORABLE OPTION FOR
NOW...BUT WILL CONTINUE TO MONITOR AND REASSESS AS NEEDED. -KT
UPDATE ISSUED AT 459 PM MST SUN NOV 24 2013
QUICK UPDATE TO BUMP UP POPS ACROSS EL PASO AND NORTHWEST PUEBLO
COUNTIES WHERE DEFORMATION BAND HAS SET UP. GETTING REPORTS OF MODERATE
SNOW WITHIN THIS BAND AND SUSPECT A QUICK INCH OR TWO WILL BE
POSSIBLE WITHIN THE NEXT HOUR OR TWO. BASED ON SHORT RANGE HIGH RES
MODELS...FOCUS FOR HEAVIER SNOWFALL WILL SHIFT INTO THE NORTHEAST
FACING SLOPES OF THE SOUTHEAST MOUNTAINS AND FREMONT COUNTY AS THE
EVENING PROGRESSES. HOWEVER MODELS ARE NOT RESOLVING THE CURRENT
SNOW BAND VERY WELL...SO EXPECT A HIGHLY EVOLVING FORECAST TONIGHT
AS THESE DETAILS GET RESOLVED. FOR NOW...HAVE BUMPED UP POPS INTO
THE LIKELY CATEGORY FOR EL PASO...FREMONT...AND WESTERN PUEBLO
COUNTIES THROUGH 06Z. IF BAND STALLS OVER ANY PARTICULAR
AREA...SOME LOCAL ACCUMULATIONS OF UP TO 4 INCHES WILL BE POSSIBLE
OVER THE LOWER ELEVATIONS. -KT
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
...SNOW WINDING DOWN ON MONDAY...
UPPER LOW IS NOW NOW MOVING EASTWARD ALONG THE CO NM BORDER. COLDER CLOUD
TOPS HAVE SHIFTED TO THE NE PORTION OF CO...WHERE SEVERAL BANDS OF
SNOW ARE ROTATING NORTHWESTWARD ALONG THE NRN I-25 CORRIDOR. THE LOW HAS
DEFINITELY TAKEN A MORE NRN TRACK AS THE NAM AND ESPECIALLY THE
ECMWF HAD FORECAST IT TO DO. HOWEVER...NOT A LOT OF MOISTURE LEFT
WITH THE SYSTEM...AND ACCUMS TONIGHT INTO MON MORNING PROBABLY WILL
NOT BE ALL THAT IMPRESSIVE. MAIN FOCUS FOR HEAVIER ACCUMS WILL BE
DUE TO N-NE WINDS INCREASING TONIGHT AS THE LOW CONTINUES TO MOVE
AWAY. LATEST RUC SHOWING H7 WINDS INCREASING TO 30-40 KTS AFTER
ABOUT 04Z TONIGHT. THIS WILL LEAD TO SOME DECENT OROGRAPHIC ACCUMS
OVER THE HIGHER ELEVATIONS OF THE ERN MT RANGES OVERNIGHT...AND
FAVORED SPOTS LIKE CUCHARA COULD SEE SOME RESPECTABLE SNOWFALL.
LATEST HI RES MODELS REALLY SHOWING THIS POTENTIAL OVER THE WETS AND
NRN SANGRES...SO WILL ADD THE WETS TO THE CURRENT SUITE OF
ADVISORIES WE HAVE OUT THROUGH 12Z MONDAY. ELSEWHERE...BEST BET OF
SNOW OVER THE PLAINS WILL BE ALONG AND WEST OF I-25...AND ESPECIALLY
SOUTH OF HIGHWAY 50. COULD SEE SOME LIGHT ACCUMS OVER THE HIGHER
TRRN BUT NOT EXPECTING ANYTHING SIGNIFICANT. INHERITED LOW POPS FOR
THE PLAINS STILL LOOK ON TARGET SO HAVE NOT MADE ANY EXTENSIVE
CHANGES THERE.
SHOULD SEE SNOW TAPER OFF FROM N TO S ESPECIALLY AFTER MID-MORNING
ON MONDAY. JUST A FEW LINGERING SHOWERS OVER THE SRN MTS AND FAR
SERN PLAINS BY MON AFTERNOON. BREEZY CONDITIONS WILL PERSIST IN THE
WAKE OF THE LOW...ESPECIALLY OVER BACA COUNTY WHICH COULD SEE SOME
GUSTS IN THE 30-40 KT RANGE FOR THE LATE MORNING TO EARLY AFTERNOON
PERIOD. TEMPS ALOFT WILL ACTUALLY BE FALLING SIGNIFICANTLY THROUGH
MONDAY MORNING...DOWN TO AROUND MINUS 7 OR 8 C AT H7...BUT WITH GOOD
MIXING IN THE LOW TO MID LEVELS...SHOULD SEE TEMPS TOP OUT HIGHER
THAN THE TEMPS THIS AFTERNOON. HAVE CUT BACK TEMPS A BIT BELOW
GUIDANCE HOWEVER...SINCE EVEN WITH GOOD ADIABATIC MIXING THE TEMPS
ALOFT WILL PROBABLY ONLY SUPPORT 40 DEGREES OR SO AT BEST BY THE
AFTERNOON. SO...IT WILL BE A RAW DAY DESPITE THE LOWERED POPS.
ROSE
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 241 PM MST SUN NOV 24 2013
MONDAY NIGHT...UPPER LOW OVER WEST TEXAS FORECAST BY MODELS TO SLIDE
SOUTHEAST...BUT SOME MOISTURE IN NORTHERLY FLOW ALOFT WILL PERSIST
THROUGH PART OF THE NIGHT. INHERITED ISOLATED POPS AT MOST OVER THE
EASTERN MOUNTAINS THROUGH MIDNIGHT...AND THAT LOOKS GOOD. SNOW
ACCUMULATIONS WILL BE WELL UNDER AN INCH. LOW TEMPERATURES WILL BE
IN THE LOWER SINGLE DIGITS ACROSS THE SAN LUIS VALLEY...WITH SNOW
COVER AND RADIATIONAL COOLING. ELSEWHERE...TEMPERATURES SHOULD DIP
INTO THE TEENS ACROSS THE PLAINS AND OTHER HIGH VALLEYS...WITH
SINGLE DIGITS ACROSS THE HIGHEST ELEVATIONS.
FOR THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND...THE WEATHER
LOOKS TO BE FAIRLY TRANQUIL...AS AN UPPER LEVEL RIDGE GETS
ESTABLISHED OVER THE GREAT BASIN AND ROCKIES. A WEAK FRONT MAY
BRIEFLY AFFECT THE EASTERN PLAIN THANKSGIVING DAY...BUT WITH NO
PRECIPITATION. A COUPLE MORE SHORTWAVES IN THE NORTHERN
STREAM...WILL BRING SOME CLOUDS...WITH THE SECOND ONE...DURING THE
WEEKEND...BRINGING A CHANCE FOR SOME HIGHER ELEVATION SNOW SHOWERS.
-TLM-
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1030 PM MST SUN NOV 24 2013
THE UPPER LOW TRACKING ACROSS NORTHERN NM WAS CONTINUING TO DRAW
MOISTURE AND SFC FLOW OUT OF THE N-NE. SNOWFALL BLOSSOMED UNDER
THIS FLOW AROUND 4 PM THIS EVE AND HAS CONTINUED THROUGHOUT THE
NIGHT...WITH THE HEAVIEST BAND INITIALLY OVER SOUTHERN EL PASO
COUNTY GRADUALLY SAGGING TO THE SOUTH. HEAVIEST HIT AREAS HAVE
BEEN THE WET MT VALLEY...EASTERN MTS...AND LOCALIZED AREAS ON THE
BACKSIDE OF THE SANGRES WHERE SNOW HAS SEEMINGLY SPILLED OVER THE
RIDGE. THE HEAVIER SNOWFALL HAS NOW DROPPED SOUTH...WHERE IFR TO
LIFR CONDITIONS ARE AFFECTING KALS AND KTAD. FURTHER NORTH...KPUB
REPORTED MVFR TO IFR CONDITIONS...AND KCOS HAS NOW CLEARED OUT OF
THE SNOW WITH VFR CONDITIONS.
THE UPPER LOW WILL CONTINUE EAST OVERNIGHT AND THROUGH
TOMORROW...AND SNOW IS EXPECTED TO DIMINISH OVERNIGHT ACROSS THE
SOUTHERN TIER BETWEEN 08Z AND 10Z. STRONG AND GUSTY NORTHERLY
WINDS WILL SETTLE IN ACROSS THE AREA ON THE BACK SIDE OF THE
DEPARTING LOW...LASTING UNTIL AROUND 15Z. MOORE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM MST MONDAY FOR COZ060-066-
072>075-079-080.
WINTER STORM WARNING UNTIL 5 AM MST MONDAY FOR COZ068.
&&
$$
UPDATE...KT
SHORT TERM...ROSE
LONG TERM...TM
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1007 PM EST TUE NOV 26 2013
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHEAST STATES WILL INTENSIFY AND MOVE UP
THE COAST TONIGHT...PASSING OVER THE AREA ON WEDNESDAY AND THEN
HEADING INTO EASTERN CANADA WEDNESDAY NIGHT. HIGH PRESSURE WILL
THEN BUILDS IN FROM THURSDAY THROUGH SATURDAY...AND MOVE OFF THE
NEW ENGLAND COAST ON SUNDAY. A COASTAL FRONT WILL DEVELOP ON
SUNDAY AND REMAIN INTO MONDAY. LOW PRESSURE WILL DEVELOP ON THE
FRONT AND MOVE ALONG THE COAST ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
FORECAST MAINLY ON TRACK...WITH MAIN ADJUSTMENT TO T/TDS. HAVE
EXTENDED WINTER WEATHER ADVISORY FOR ORANGE COUNTY UNTIL 1 AM.
WINDS HAVE BACKED TO THE NORTH ACROSS MAINLY THE EASTERN HALF OF
ORANGE COUNTY...ALLOWING TEMPS TO HOLD AROUND FREEZING. THIS WILL
RESULT IN POCKETS OF FREEZING RAIN AND ICY TRAVEL UNTIL AROUND
MIDNIGHT. MARGINAL TEMPS SHOULD CONTINUE TO CREEP HIGHER AS STRONG
WAA ENSUES TOWARDS MIDNIGHT...CHANGING PRECIP TO ALL RAIN AFTER
MIDNIGHT.
ELSEWHERE...RAIN WILL INCREASE IN INTENSITY TONIGHT 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 LLJ ALSO LOOKS STRONG ENOUGH TO SUPPORT STRONG SE-S WINDS
ALONG THE COAST...SO THE WIND ADVY CONTINUES. VERY STRONG NAM LLJ
WITH 85-95 KT AT H8 MAY LOOK LIKE AN OUTLIER COMPARED TO
WEAKER/FARTHER EAST GFS/ECMWF...BUT LATEST RUNS OF THE RAP DO LEND
IT SUPPORT SO AM NOT WILLING TO DISCOUNT IT. SFC-H8 INVERSION
SHOULD PREVENT THE STRONGEST OF THESE WINDS FROM MIXING DOWN.
HOWEVER HAVE A NAGGING CONCERN THAT DUCTED GRAVITY WAVES COULD
AID IN DOWNWARD MOMENTUM TRANSPORT TOWARD MORNING PER AKQ
RESEARCH...AS WEAK INSTABILITY MOVES IN ALOFT JUST NORTH OF AN
APPROACHING WARM FRONT...AND AS THE UPPER JET STREAK APPROACHES
THE DOWNSTREAM INFLECTION POINT BETWEEN THE UPPER TROUGH TO THE
WEST AND OFFSHORE RIDGING...SO POTENTIAL FOR 60+ MPH WIND GUSTS
ACROSS LONG ISLAND AND COASTAL SE CT WILL HAVE TO BE WATCHED. MOST
LIKELY SCENARIO WILL BE FOR SUSTAINED WINDS 25-35 MPH WITH GUSTS
45-50 MPH...MAINLY IN/NEAR NYC AND ALONG THE COAST BEGINNING LATE
TONIGHT.
THERE COULD BE A FEW RUMBLES OF THUNDER LATE AS ELEVATED
INSTABILITY MOVES OVER THE AREA.
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 WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE LOW WILL BE MOVING ACROSS THE REGION WED MORNING INTO EARLY
AFTERNOON...THEN RE-CONSOLIDATING TO THE NORTH IN THE AFTERNOON.
HEAVY RAIN...STRONG SOUTHERLY WINDS AND ISOLD RUMBLES OF THUNDER
WILL STILL BE ONGOING INITIALLY...THEN SHOULD SHIFT TO THE EAST
ACROSS ERN LONG ISLAND/CT DURING LATE MORNING AND LIFT UP INTO NEW
ENGLAND BY AFTERNOON AS THIS TAKES PLACE. ENDED WIND ADVY EARLIER
THAN ORIGINALLY FCST SINCE THE LOW TRACK SHOULD BE SLIGHTLY
FARTHER EAST...WITH THE LLJ ALSO PASSING TO THE EAST SOONER.
RAIN SHOULD LESSEN IN INTENSITY AS WELL AS AS THE LLJ PASSES TO
THE EAST.
AS THE LOW MOVES OVER THE AREA...THERE SHOULD BE A RELATIVE LULL
IN WINDS FROM LATE MORNING INTO EARLY AFTERNOON...THEN STRONG NW
WINDS WILL REDEVELOP BY EVENING AS THE LOW CONTINUES TO INTENSIFY
AND SHOULD CONTINUE INTO THE NIGHT...SUSTAINED AT 20-30 MPH WITH
GUSTS UP TO 40 MPH...POSSIBLY STRONGER IN NYC METRO AND LONG
ISLAND WHERE ANOTHER WIND ADVY MAY BE NEEDED. STILL EXPECT SCT
SHOWERS IN THE EVENING AS THE UPPER TROUGH MOVES ACROSS...AND LOW
LEVEL CAA SHOULD CHANGE ANY PRECIP OVER TO SNOW FROM NYC
NORTH/WEST. SOME INTERIOR AREAS COULD SEE A LIGHT COATING OF
ACCUMULATION OF SNOW BEFORE ALL PRECIP ENDS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
VIGOROUS SHORTWAVE IS ROTATING EAST OF THE REGION EARLY THURSDAY
MORNING AS BROAD UPPER TROUGH REMAINS ACROSS THE NORTHEAST. ANOTHER
SHORTWAVE ROTATES THROUGH THE TROUGH LATE THURSDAY INTO THURSDAY
NIGHT. MEANWHILE AT THE SURFACE LOW PRESSURE WILL BE NORTH AND EAST
OF THE AREA AND CONTINUING TO MOVE NORTH DURING THE DAY INTO
THURSDAY NIGHT AS HIGH PRESSURE BUILDS TO THE WEST. INCREASING
SUBSIDENCE BEHIND THE LOW WILL KEEP AREA PRECIPITATION FREE
THURSDAY...ALTHOUGH CLOUDS WILL LINGER EARLY IN THE DAY. UPPER FLOW
BECOMES MORE ZONAL FRIDAY AND INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS OVER THE REGION. WARM ADVECTION SETS UP LATE
SATURDAY NIGHT AND INTO SUNDAY AS HIGH PRESSURE MOVES EAST AND NEXT
SHORTWAVE APPROACHES FROM THE GREAT LAKES. LIFT IS RATHER WEAK AT
THIS TIME AND MOISTURE LIMITED HOWEVER...THERE IS A VERY LOW
PROBABILITY OF LIGHT PRECIPITATION LATE SATURDAY NIGHT. SUNDAY WILL
BE A BETTER CHANCE AS ADVECTION CONTINUES AND GULF MOISTURE MOVES
INTO THE AREA. AS THE HIGH RETREATS TO THE NORTHEAST SATURDAY NIGHT
INTO SUNDAY...COLD AIR DAMNING IS POSSIBLE AND MIXED PRECIPITATION
WILL BE POSSIBLE INLAND AS COASTAL AREAS WARM IN THE SOUTHERLY FLOW.
A COASTAL FRONT DEVELOPS SUNDAY INTO MONDAY AS A WEAK SOUTHERN
STREAM SHORTWAVE MOVES OUT OF THE SOUTHWEST AND INTO THE GULF COAST
REGION. THIS WAVE WILL DEVELOP A LOW ALONG THE COASTAL FRONT MONDAY
INTO TUESDAY. STILL SOME UNCERTAINTY WITH THE TRACK OF LOW WITH THE
ECMWF CLOSER TO THE COAST AND THE GFS MOVING THE LOW FARTHER OFF THE
SOUTHEASTERN COAST AND KEEPING THE REGION ON THE NORTHWESTERN EDGE
OF THE PRECIPITATION TUESDAY.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
**HIGH IMPACT AVIATION WEATHER EVENT FOR TONIGHT AND WEDNESDAY**
DETERIORATING CONDITIONS OVERNIGHT WITH AN APPROACHING LOW
PRESSURE SYSTEM. VARYING IFR/LIFR CONDITIONS THROUGH THE
NIGHT AND TOMORROW MORNING...WITH GRADUAL IMPROVEMENT TOMORROW AFTN
INTO TOMORROW NIGHT.
WINDS ELY 5-10 KTS THIS EVENING..BCMG ESE AROUND 10 KTS...WITH
GUSTS INTO THE 20S/30S BY 05Z. WIND SHEAR BECOMES AN ISSUE NYC
TERMINALS AND EAST 08Z-14Z TOMORROW...WITH SLY WINDS UP TO 70 KTS
AT 2000 FT. WINDS GRADUALLY DIMINISH AND SHIFT TO THE SW THEN NW
BY TOMORROW AFTN. TIMING OF WIND SHIFTS MAY BE 1-2 HOURS. GUSTS
WILL REMAIN ACROSS THE ENTIRE INTO TOMORROW NIGHT.
EXPECT IFR AND LIFR CIGS AS HEAVIER PCPN MOVES IN AFTER 03Z. BEST
CHC FOR LIFR WILL BE BETWEEN 07Z AND 15Z. PCPN LINGERS DURING THE
DAY TOMORROW...WITH GRADUALLY IMPROVING CIGS AFTER 15Z. PCPN
SHOULD REMAIN ALL RAIN FROM HERE ON OUT.
.OUTLOOK FOR 03Z THURSDAY THROUGH MONDAY...
.WED NGT. MVFR EARLY...BECOMING VFR. CHC -SHSNRA. W-NW WINDS
20-25G35KT.
.THU...VFR. NW WINDS 20-25G30-35KT EARLY SLOWLY DIMINISHING TO G20KT
BY EVENING.
.THU NGT-SAT...VFR.
.SUN AND MON...MVFR CIG. -DZ / -RA. SE SFC FLOW 10-15 KT.
&&
.MARINE...
THE PRESSURE GRADIENT WILL QUICKLY TIGHTEN TONIGHT AHEAD OF AN
ADVANCING STORM SYSTEM TRACKING FROM THE SOUTHEASTERN TO COASTAL
MID ATLANTIC STATES TONIGHT...WITH WIND GUSTS TO GALE LEVELS
DEVELOPING AFTER MIDNIGHT. A FEW GUSTS TO STORM FORCE MAY BE
POSSIBLE TOWARD MORNING...MAINLY ON THE ERN OCEAN WATERS...BUT
THESE SHOULD BE BRIEF AT BEST AND SO DID NOT UPGRADE ANY AREAS TO
A STORM WARNING. WILL USE SPECIAL MARINE WARNINGS TO ADDRESS ANY
WIND GUSTS OF 48 KT OR HIGHER IN ISOLATED STRONGER CONVECTION.
SEAS COULD BUILD AS HIGH AS 16 FT ON THE ERN OCEAN WATERS WITH THE
STRONGEST SOUTHERLY WINDS.
THERE COULD BE A LULL IN WINDS FROM LATE WED MORNING INTO THE
AFTERNOON...BUT THEN NW GALES ARE EXPECTED WED NIGHT INTO
THU MORNING...WITH SEAS UP TO 15 FT EXPECTED WED NIGHT ON THE
OCEAN AND AS HIGH AS 7 FT ON LONG ISLAND SOUND AS THE SURFACE LOW
CONTINUES TO TRACK TO THE NORTH THROUGH CANADA AND HIGH PRESSURE
BUILDS TO THE WEST. THE WIND WILL BE DIMINISHING THROUGH THE DAY
THURSDAY...SUBSIDING BELOW GALE FORCE DURING THE AFTERNOON...AND
THEN QUICKLY FALLING BELOW 25 KT DURING THURSDAY EVENING.
VERY ROUGH SEAS ON THE OCEAN WATERS SUBSIDE DURING THURSDAY IN THE
WEST TO NORTHWEST FLOW. BY LATE THURSDAY NIGHT SEAS ARE EXPECTED TO
FALL BELOW 5 FT AS THE WESTERLY FLOW DIMINISHES.
WIND AND SEAS REMAIN BELOW ADVISORY LEVELS FRIDAY INTO SUNDAY.
DEPENDING ON THE STRENGTH OF THE WIND AROUND A DEPARTING HIGH AND A
DEVELOPING TROUGH ALONG THE COAST...SEAS ON THE OCEAN WATERS MAY
BUILD BACK UP TO SMALL CRAFT LEVELS LATE SUNDAY INTO SUNDAY
NIGHT.
&&
.HYDROLOGY...
WIDESPREAD RAINFALL TOTALS FORECAST RANGE BETWEEN 2 AND 3 INCHES
WITH LOCAL AMOUNTS UP TO 4 INCHES. DUE 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 WEDNESDAY AFTERNOON FOR CTZ005>012.
WIND ADVISORY UNTIL 2 PM EST WEDNESDAY FOR CTZ008-011-012.
WIND ADVISORY UNTIL 9 AM EST WEDNESDAY FOR CTZ007-009-010.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
CTZ009-010.
NY...FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR NYZ067>075-078>081-
176>179.
WIND ADVISORY UNTIL 2 PM EST WEDNESDAY FOR NYZ078>081-177-179.
COASTAL FLOOD ADVISORY FROM 3 AM TO 9 AM EST WEDNESDAY FOR
NYZ079-081.
WIND ADVISORY UNTIL 9 AM EST WEDNESDAY FOR NYZ071>075-176-178.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
NYZ071-073.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ067.
HIGH SURF ADVISORY UNTIL MIDNIGHT EST WEDNESDAY NIGHT FOR
NYZ080-081-178-179.
NJ...FLOOD WATCH THROUGH WEDNESDAY AFTERNOON FOR NJZ002-004-006-
103>108.
WIND ADVISORY UNTIL 9 AM EST WEDNESDAY 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/NV
SHORT TERM...GOODMAN
LONG TERM...MET
AVIATION...SEARS
MARINE...GOODMAN/MET/NV
HYDROLOGY...GOODMAN/MET
TIDES/COASTAL FLOODING...NV
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
723 PM EST TUE NOV 26 2013
.SYNOPSIS...
LOW PRESSURE OVER THE SOUTHEAST STATES WILL INTENSIFY AND MOVE UP
THE COAST TONIGHT...PASSING OVER THE AREA ON WEDNESDAY AND THEN
HEADING INTO EASTERN CANADA WEDNESDAY NIGHT. HIGH PRESSURE WILL
THEN BUILDS IN FROM THURSDAY THROUGH SATURDAY...AND MOVE OFF THE
NEW ENGLAND COAST ON SUNDAY. A COASTAL FRONT WILL DEVELOP ON
SUNDAY AND REMAIN INTO MONDAY. LOW PRESSURE WILL DEVELOP ON THE
FRONT AND MOVE ALONG THE COAST ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
FORECAST ON TRACK...WITH OVERUNNING PRECIP EXPECTED TO CONTINUE TO
INCREASE IN INTENSITY THROUGH THE EVENING...AS LOW PRESSURE OVER
THE SOUTHEAST US INTENSIFIES AND TRACKS NE TOWARDS THE REGION.
IMPENDING STORM WILL BRING A VARIETY OF WEATHER HAZARDS BEGINNING
TONIGHT. WILL ALLOW WINTER WX ADVISORY TO CONTIUE FOR A MIX OF
RAIN AND SLEET AND POCKETS OF FZRA OVER ORANGE COUNTY. EXPECTATION
WITH MARGINAL TEMPS CONTINUE TO CREEP HIGHER AND INCREASING
WAA...TEMPS SHOULD CONTINUE TO RISE AND CHANGE PRECIP TO ALL RAIN
BY LATE EVENING.
ELSEWHERE...RAIN WILL INCREASE IN INTENSITY FROM LATE EVENING ON
AS PRIMARY LOW PRESSURE WEAKENS ALONG A LOW LEVEL BAROCLINIC ZONE
ALONG THE COASTAL PLAIN...AND GIVES WAY TO A SECONDARY LOW OVER
THE MID ATLANTIC FORMING UNDER THE STRENGTHENING RIGHT ENTRANCE
REGION OF A DIFLUENT UPPER JET STREAK APPROACHING FROM THE WEST AS
A NORTHERN/SOUTHERN STREAMS PHASE ALOFT. A S-SE LOW LEVEL JET WILL
INTENSIFY EAST OF THE LOW OVERNIGHT... TRANSPORTING ATLANTIC/GULF
MOISTURE INTO THE REGION AND PROVIDING AMPLE LOW LEVEL
CONVERGENCE/LIFT FOR HEAVY RAIN. OROGRAPHIC LIFT WILL ALSO COME
INTO PLAY NORTH/WEST OF NYC GIVEN THE LOW LEVEL SE FLOW TO START.
GIVEN THESE FACTORS THE POTENTIAL FOR AREAL/URBAN FLOODING AND
FLOODING OF SMALL STREAMS NOW LOOKS GREAT ENOUGH TO WARRANT A
FLOOD WATCH.
THE LLJ ALSO LOOKS STRONG ENOUGH TO SUPPORT STRONG SE-S WINDS
ALONG THE COAST...SO THE WIND ADVY CONTINUES. VERY STRONG NAM LLJ
WITH 85-95 KT AT H8 MAY LOOK LIKE AN OUTLIER COMPARED TO
WEAKER/FARTHER EAST GFS/ECMWF...BUT LATEST RUNS OF THE RAP DO LEND
IT SUPPORT SO AM NOT WILLING TO DISCOUNT IT. SFC-H8 INVERSION
SHOULD PREVENT THE STRONGEST OF THESE WINDS FROM MIXING DOWN.
HOWEVER HAVE A NAGGING CONCERN THAT DUCTED GRAVITY WAVES COULD
AID IN DOWNWARD MOMENTUM TRANSPORT TOWARD MORNING PER AKQ
RESEARCH...AS WEAK INSTABILITY MOVES IN ALOFT JUST NORTH OF AN
APPROACHING WARM FRONT...AND AS THE UPPER JET STREAK APPROACHES
THE DOWNSTREAM INFLECTION POINT BETWEEN THE UPPER TROUGH TO THE
WEST AND OFFSHORE RIDGING...SO POTENTIAL FOR 60+ MPH WIND GUSTS
ACROSS LONG ISLAND AND COASTAL SE CT WILL HAVE TO BE WATCHED. MOST
LIKELY SCENARIO WILL BE FOR SUSTAINED WINDS 25-35 MPH WITH GUSTS
45-50 MPH...MAINLY IN/NEAR NYC AND ALONG THE COAST BEGINNING LATE
TONIGHT.
THERE COULD BE A FEW RUMBLES OF THUNDER LATE AS ELEVATED
INSTABILITY MOVES OVER THE AREA.
TEMPS WILL BE ON THE RISE TONIGHT...REACHING THE MID AND UPPER 50S
BY MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE LOW WILL BE MOVING ACROSS THE REGION WED MORNING INTO EARLY
AFTERNOON...THEN RE-CONSOLIDATING TO THE NORTH IN THE AFTERNOON.
HEAVY RAIN...STRONG SOUTHERLY WINDS AND ISOLD RUMBLES OF THUNDER
WILL STILL BE ONGOING INITIALLY...THEN SHOULD SHIFT TO THE EAST
ACROSS ERN LONG ISLAND/CT DURING LATE MORNING AND LIFT UP INTO NEW
ENGLAND BY AFTERNOON AS THIS TAKES PLACE. ENDED WIND ADVY EARLIER
THAN ORIGINALLY FCST SINCE THE LOW TRACK SHOULD BE SLIGHTLY
FARTHER EAST...WITH THE LLJ ALSO PASSING TO THE EAST SOONER.
RAIN SHOULD LESSEN IN INTENSITY AS WELL AS AS THE LLJ PASSES TO
THE EAST.
AS THE LOW MOVES OVER THE AREA...THERE SHOULD BE A RELATIVE LULL
IN WINDS FROM LATE MORNING INTO EARLY AFTERNOON...THEN STRONG NW
WINDS WILL REDEVELOP BY EVENING AS THE LOW CONTINUES TO INTENSIFY
AND SHOULD CONTINUE INTO THE NIGHT...SUSTAINED AT 20-30 MPH WITH
GUSTS UP TO 40 MPH...POSSIBLY STRONGER IN NYC METRO AND LONG
ISLAND WHERE ANOTHER WIND ADVY MAY BE NEEDED. STILL EXPECT SCT
SHOWERS IN THE EVENING AS THE UPPER TROUGH MOVES ACROSS...AND LOW
LEVEL CAA SHOULD CHANGE ANY PRECIP OVER TO SNOW FROM NYC
NORTH/WEST. SOME INTERIOR AREAS COULD SEE A LIGHT COATING OF
ACCUMULATION OF SNOW BEFORE ALL PRECIP ENDS.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
VIGOROUS SHORTWAVE IS ROTATING EAST OF THE REGION EARLY THURSDAY
MORNING AS BROAD UPPER TROUGH REMAINS ACROSS THE NORTHEAST. ANOTHER
SHORTWAVE ROTATES THROUGH THE TROUGH LATE THURSDAY INTO THURSDAY
NIGHT. MEANWHILE AT THE SURFACE LOW PRESSURE WILL BE NORTH AND EAST
OF THE AREA AND CONTINUING TO MOVE NORTH DURING THE DAY INTO
THURSDAY NIGHT AS HIGH PRESSURE BUILDS TO THE WEST. INCREASING
SUBSIDENCE BEHIND THE LOW WILL KEEP AREA PRECIPITATION FREE
THURSDAY...ALTHOUGH CLOUDS WILL LINGER EARLY IN THE DAY. UPPER FLOW
BECOMES MORE ZONAL FRIDAY AND INTO THE WEEKEND AS SURFACE HIGH
PRESSURE BUILDS OVER THE REGION. WARM ADVECTION SETS UP LATE
SATURDAY NIGHT AND INTO SUNDAY AS HIGH PRESSURE MOVES EAST AND NEXT
SHORTWAVE APPROACHES FROM THE GREAT LAKES. LIFT IS RATHER WEAK AT
THIS TIME AND MOISTURE LIMITED HOWEVER...THERE IS A VERY LOW
PROBABILITY OF LIGHT PRECIPITATION LATE SATURDAY NIGHT. SUNDAY WILL
BE A BETTER CHANCE AS ADVECTION CONTINUES AND GULF MOISTURE MOVES
INTO THE AREA. AS THE HIGH RETREATS TO THE NORTHEAST SATURDAY NIGHT
INTO SUNDAY...COLD AIR DAMNING IS POSSIBLE AND MIXED PRECIPITATION
WILL BE POSSIBLE INLAND AS COASTAL AREAS WARM IN THE SOUTHERLY FLOW.
A COASTAL FRONT DEVELOPS SUNDAY INTO MONDAY AS A WEAK SOUTHERN
STREAM SHORTWAVE MOVES OUT OF THE SOUTHWEST AND INTO THE GULF COAST
REGION. THIS WAVE WILL DEVELOP A LOW ALONG THE COASTAL FRONT MONDAY
INTO TUESDAY. STILL SOME UNCERTAINTY WITH THE TRACK OF LOW WITH THE
ECMWF CLOSER TO THE COAST AND THE GFS MOVING THE LOW FARTHER OFF THE
SOUTHEASTERN COAST AND KEEPING THE REGION ON THE NORTHWESTERN EDGE
OF THE PRECIPITATION TUESDAY.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
**HIGH IMPACT AVIATION WEATHER EVENT FOR TONIGHT AND WEDNESDAY**
DETERIORATING CONDITIONS THIS EVENING AND OVERNIGHT WITH AN
APPROACHING LOW PRESSURE SYSTEM. BRIEF PERIOD OF VFR THROUGH 01Z
WILL GIVE WAY QUICKLY TO IFR CIGS/VIS.
WINDS ELY 5-10 KTS THIS EVENING..BCMG ESE AROUND 10 KTS...WITH
GUSTS INTO THE 20S/30S BY 06Z. WIND SHEAR BECOMES AN ISSUE NYC
TERMINALS AND EAST 08Z-14Z TOMORROW...WITH SLY WINDS UP TO 70 KTS
AT 2000 FT. WINDS GRADUALLY DIMINISH AND SHIFT TO THE SW THEN NW
BY TOMORROW AFTN. TIMING OF WIND SHIFTS MAY BE 1-2 HOURS.
EXPECT IFR AND PSBL PERIOD OF LIFR CIGS AS HEAVIER PCPN MOVES IN
AFTER 02Z. BEST CHC FOR LIFR WILL BE BETWEEN 07Z AND 15Z. PCPN
LINGERS DURING THE DAY TOMORROW...WITH GRADUALLY IMPROVING CIGS
AFTER 15Z.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: MOD CONFIDENCE FORECAST. START TIME OF
GUSTS MAY BE +1-2 HRS. CIGS MAY LINGER AT VFR THROUGH 02Z.
KLGA FCSTER COMMENTS: MOD CONFIDENCE FORECAST. BRIEF PERIOD OF
IFR CIGS PRIOR TO 06Z. START TIME OF GUSTS MAY BE +1-2 HOURS.
KEWR FCSTER COMMENTS: MOD CONFIDENCE FORECAST. START TIME OF
GUSTS MAY BE +1-2 HOURS. IFR CONDITIONS MAY START 1 HOUR LATER.
KTEB FCSTER COMMENTS: MOD CONFIDENCE FORECAST. START TIME OF
GUSTS MAY BE +1-2 HOURS. IFR CONDITIONS MAY START 1 HOUR LATER.
KHPN FCSTER COMMENTS: MOD CONFIDENCE FORECAST.
KISP FCSTER COMMENTS: MOD CONFIDENCE FORECAST. LOWER CIGS MAY MOVE
IN 1 HOUR SOONER.
.OUTLOOK FOR 00Z THURSDAY THROUGH MONDAY...
.WED NGT. MVFR...BECOMING VFR. CHC -SHSNRA. W/NW WINDS 20-25G35KT.
.THU...VFR. NW WINDS 20-25G30-35KT EARLY SLOWLY DIMINISHING TO G20KT
BY EVENING.
.THU NGT-SAT...VFR.
.SUN AND MON...MVFR CIG. -DZ / -RA. SE SFC FLOW 10-15 KT.
&&
.MARINE...
THE PRESSURE GRADIENT WILL QUICKLY TIGHTEN TONIGHT AHEAD OF AN
ADVANCING STORM SYSTEM TRACKING FROM THE SOUTHEASTERN TO COASTAL
MID ATLANTIC STATES TONIGHT...WITH WIND GUSTS TO GALE LEVELS
DEVELOPING AFTER MIDNIGHT. A FEW GUSTS TO STORM FORCE MAY BE
POSSIBLE TOWARD MORNING...MAINLY ON THE ERN OCEAN WATERS...BUT
THESE SHOULD BE BRIEF AT BEST AND SO DID NOT UPGRADE ANY AREAS TO
A STORM WARNING. WILL USE SPECIAL MARINE WARNINGS TO ADDRESS ANY
WIND GUSTS OF 48 KT OR HIGHER IN ISOLATED STRONGER CONVECTION.
SEAS COULD BUILD AS HIGH AS 16 FT ON THE ERN OCEAN WATERS WITH THE
STRONGEST SOUTHERLY WINDS.
THERE COULD BE A LULL IN WINDS FROM LATE WED MORNING INTO THE
AFTERNOON...BUT THEN NW GALES ARE EXPECTED WED NIGHT INTO
THU MORNING...WITH SEAS UP TO 15 FT EXPECTED WED NIGHT ON THE
OCEAN AND AS HIGH AS 7 FT ON LONG ISLAND SOUND AS THE SURFACE LOW
CONTINUES TO TRACK TO THE NORTH THROUGH CANADA AND HIGH PRESSURE
BUILDS TO THE WEST. THE WIND WILL BE DIMINISHING THROUGH THE DAY
THURSDAY...SUBSIDING BELOW GALE FORCE DURING THE AFTERNOON...AND
THEN QUICKLY FALLING BELOW 25 KT DURING THURSDAY EVENING.
VERY ROUGH SEAS ON THE OCEAN WATERS SUBSIDE DURING THURSDAY IN THE
WEST TO NORTHWEST FLOW. BY LATE THURSDAY NIGHT SEAS ARE EXPECTED TO
FALL BELOW 5 FT AS THE WESTERLY FLOW DIMINISHES.
WIND AND SEAS REMAIN BELOW ADVISORY LEVELS FRIDAY INTO SUNDAY.
DEPENDING ON THE STRENGTH OF THE WIND AROUND A DEPARTING HIGH AND A
DEVELOPING TROUGH ALONG THE COAST...SEAS ON THE OCEAN WATERS MAY
BUILD BACK UP TO SMALL CRAFT LEVELS LATE SUNDAY INTO SUNDAY
NIGHT.
&&
.HYDROLOGY...
WIDESPREAD RAINFALL TOTALS FORECAST RANGE BETWEEN 2 AND 3 INCHES
WITH LOCAL AMOUNTS UP TO 4 INCHES. DUE RECENT PROLONGED DRY
CONDITIONS...MAIN STEM RIVER FLOODING IS NOT EXPECTED.
HOWEVER...THERE IS ENOUGH CHANCE OF URBAN/AREAL/SMALL STREAM
FLOODING...ESPECIALLY WHERE STORM DRAINS ARE CLOGGED BY LEAVES
AND ESSENTIALLY WHERE THERE IS MORE RUNOFF....TO WARRANT A FLOOD
WATCH FROM LATE TONIGHT INTO WED AFTERNOON.
LIGHT PRECIPITATION IS POSSIBLE SUNDAY INTO TUESDAY...WITH A TOTAL
OF UP TO A HALF INCH EXPECTED AT THIS TIME.
&&
.TIDES/COASTAL FLOODING...
A GALE FORCE SE FLOW WILL RAPIDLY DEVELOP AHEAD OF DEEPENING LOW
PRESSURE LATE TONIGHT...BEFORE VEERING TO THE S WEDNESDAY MORNING. A
STORM SURGE OF 2 TO 2 1/2 FT...LOCALLY 3 FT IS EXPECTED. THE PEAK
SURGE COINCIDES BEST WITH THE TIMING OF THE MORNING HIGH TIDE CYCLE
IN WESTERN LONG ISLAND SOUND AND PECONIC BAY. AN ADVISORY HAS BEEN
ISSUED IN THESE LOCATIONS WITH COMBINED THREAT OF STORM TIDE...WAVE
SPLASH-OVER...AND HEAVY RAIN CAUSING WIDESPREAD MINOR IMPACTS.
ELSEWHERE...TIMING OF PEAK SURGE AND HIGH TIDE APPEARS TO BE
OFFSET...WITH ONLY LOCALIZED ISSUES EXPECTED WITH WEDNESDAY MORNING
HIGH TIDE DUE TO STORM TIDE AND HEAVY RAIN. A COASTAL FLOOD
STATEMENT HAS BEEN ISSUED TO ADDRESS THIS THREAT.
FOR THE LATE AFTERNOON/EVENING HIGH TIDE CYCLE...WITH FLOW
EXPECTED TO BEGIN TURN OFFSHORE WOULD EXPECT SURGE VALUES TO BEGIN
TO FALL RAPIDLY FROM AFTERNOON ON. THE ONLY AREA TO MONITOR WOULD BE
THE SOUTH SHORE BACK BAYS WITH HIGH SURF LIMITING TIDAL DRAINAGE.
HIGH SURF AND MINOR EROSION ISSUES ARE EXPECTED LATE TONIGHT THROUGH
LATE WEDNESDAY NIGHT FROM BATTERING SURF OF 7-11 FT. MAIN CONCERN
WILL BE THE VULNERABLE DUNES AND BREACH LOCATIONS POST SANDY. A HIGH
SURF ADVISORY HAS BEEN ISSUED TO ADDRESS THIS THREAT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR CTZ005>012.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EST WEDNESDAY FOR
CTZ008-011-012.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
CTZ007-009-010.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
CTZ009-010.
NY...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR NYZ067>075-078>081-176>179.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EST WEDNESDAY FOR
NYZ078>081-177-179.
COASTAL FLOOD ADVISORY FROM 6 AM TO 9 AM EST WEDNESDAY FOR
NYZ079-081.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
NYZ071>075-176-178.
COASTAL FLOOD ADVISORY FROM 5 AM TO 8 AM EST WEDNESDAY FOR
NYZ071-073.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ067.
HIGH SURF ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EST
WEDNESDAY NIGHT FOR NYZ080-081-178-179.
NJ...FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR NJZ002-004-006-103>108.
WIND ADVISORY FROM MIDNIGHT TONIGHT TO 9 AM EST WEDNESDAY FOR
NJZ006.
MARINE...GALE WARNING FROM MIDNIGHT TONIGHT TO 6 AM EST THURSDAY FOR
ANZ330-335-338-340-345-350-353-355.
&&
$$
SYNOPSIS...GOODMAN/MET
NEAR TERM...GOODMAN/NV
SHORT TERM...GOODMAN
LONG TERM...MET
AVIATION...SEARS
MARINE...GOODMAN/MET
HYDROLOGY...GOODMAN/MET
TIDES/COASTAL FLOODING...NV
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
452 PM EST MON NOV 25 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC COAST WILL MOVE EAST
AS A WEATHER SYSTEM DEVELOPS ALONG THE GULF COAST OF TEXAS AND
LOUISIANA. LOWER CLOUDS ALREADY ENTERING THE FA FROM THE WEST. STILL
COOL AND DRY CONDITIONS IN THE LOWER LAYERS.
WATER VAPOR IMAGERY AND MSAS ANALYSIS SHOWING A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE IS DEVELOPING
ALONG THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC
LIFT AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING
THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR
PLUS SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL
HOLD OFF UNTIL LATE TONIGHT. THE 1600 GMT HRRR INDICATED AREAS OF
LIGHT PRECIPITATION DEVELOPING IN THE WEST PART OF THE FORECAST
AREA AROUND MIDNIGHT...WITH THE BULK OF THE PRECIPITATION ABOUT TO
MOVE INTO THE WEST PART OF THE AREA AT 200 AM. USED THIS GUIDANCE
FOR THE TIMING.
THE MODELS INDICATE ENOUGH WARMING SHOULD OCCUR FOR ALL LIQUID
PRECIPITATION. ALL SREF MEMBERS KEEP THE SURFACE TEMPERATURE ABOVE
FREEZING LATE TONIGHT...EVEN IN THE NORTH PART. FREEZING RAIN IS
NOT IMPOSSIBLE IN THE EXTREME NORTH SECTION...BUT BELIEVE
PRECIPITATION WILL BE LIGHT AT THE ONSET LIMITING WET-BULB
COOLING. ALSO...THE NAM AND GFS SHOW SURFACE WET-BULB TEMPERATURES
RISING ABOVE FREEZING BEFORE SIGNIFICANT PRECIPITATION REACHES THE
AREA LATE TONIGHT. DESPITE THE MODEL GUIDANCE...THERE MAY BE
LAYERS OF DRY AIR ALOFT WITH WET-BULB COOLING WHICH COULD SUPPORT
SLEET. WE BELIEVE ANY SLEET WOULD BE LIGHT AND WITH SURFACE
TEMPERATURES JUST ABOVE FREEZING...NO ACCUMULATION SHOULD OCCUR.
WE USED THE COOLER TEMPERATURE GUIDANCE TONIGHT BECAUSE OF THE
DRY AIR IN PLACE AND EVAPORATIVE COOLING ASSOCIATED WITH THE
MOISTURE INCREASE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS THROUGH MOST OF TONIGHT THEN DETERIORATING TO IFR
BY 09Z.
HIGH PRESSURE ACROSS THE REGION WILL WEAKEN AND SHIFT INTO THE
ATLANTIC AS LOW PRESSURE ALONG THE NORTHWEST GULF COAST SHIFTS
NORTHEASTWARD. DUE TO MOISTURE FLUX INTO THE AREA AHEAD OF THE
APPROACHING WEATHER SYSTEM...CEILINGS HAVE ALREADY LOWERED TO
AROUND 3500 FT. LIGHT RAIN SHOULD SPREAD INTO THE AREA AROUND 08Z-
09Z AND CONTINUE SPREADING TOWARD THE NORTHEAST AS THE SURFACE LOW
APPROACHES. BY 10Z-12Z...WIDESPREAD RAINFALL IS EXPECTED AND
CONDITIONS SHOULD DETERIORATE RAPIDLY TO IFR. AT THE MORE
NORTHEAST TAF SITES LIKE CAE AND CUB...IFR CONDITIONS MAY BE
DELAYED AS LONG AS 14Z BUT CONDITIONS WILL ALSO DETERIORATE
RAPIDLY AT THOSE LOCATIONS WHEN THE RAIN MOVES IN. MAINLY
MODERATE RAIN ON TUESDAY BUT DUE TO INCREASING ISENTROPIC
LIFT...CANNOT RULE OUT SOME HEAVY RAIN ESPECIALLY AT THE WESTERN
TAF SITES. ALSO WITH INCREASING INSTABILITY ALOFT...A FEW ELEVATED
THUNDERSTORMS ARE POSSIBLE BUT CONFIDENCE WAS TOO LOW TO INCLUDE
IN THIS TAF PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT AS A LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE
SOUTHEASTERN STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
420 PM EST MON NOV 25 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...HIGH PRESSURE WILL WEAKEN THIS AFTERNOON AS A
WEATHER SYSTEM DEVELOPS IN THE WESTERN GULF COAST STATES OF TEXAS
AND LOUISIANA. THE UPPER RIDGE AXIS OVER THE FA WILL SHIFT EAST
AND ALLOW HIGH AND MID LEVEL CLOUDS TO ENTER THE REGION FROM
THE WEST. STILL COOL AND DRY CONDITIONS IN THE LOWER LAYERS.
AFTERNOON HIGHS MAINLY IN THE MID TO UPPER 40S. A BIT WARMER
IN THE CSRA AND AGS MAY HIT 51 OR 52. LIGHT MAINLY EASTERLY
WINDS ARE EXPECTED. DEWPOINTS IN THE SINGLE DIGITS EARLY THIS
AFTERNOON SHOULD INCREASE TO 10-15 DEGREES BY LATE AFTERNOON
AS MOISTURE BEGINS TO ENTER AREA.
TONIGHT...THE LATEST WATER VAPOR IMAGERY SHOWED A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE IS DEVELOPING
ALONG THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC
LIFT AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING
THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR
PLUS SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL HOLD
OFF UNTIL LATE TONIGHT. THE 1600 GMT HRRR INDICATED AREAS OF LIGHT
PRECIPITATION DEVELOPING IN THE WEST PART OF THE FORECAST AREA
AROUND MIDNIGHT...WITH THE BULK OF THE PRECIPITATION ABOUT TO MOVE
INTO THE WEST PART OF THE AREA AT 200 AM. USED THIS GUIDANCE FOR
THE TIMING.
THE MODELS INDICATE ENOUGH WARMING SHOULD OCCUR FOR ALL LIQUID
PRECIPITATION. ALL SREF MEMBERS KEEP THE SURFACE TEMPERATURE ABOVE
FREEZING LATE TONIGHT...EVEN IN THE NORTH PART. FREEZING RAIN IS
NOT IMPOSSIBLE IN THE EXTREME NORTH SECTION...BUT BELIEVE
PRECIPITATION WILL BE LIGHT AT THE ONSET LIMITING WET-BULB
COOLING. ALSO...THE NAM AND GFS SHOW SURFACE WET-BULB TEMPERATURES
RISING ABOVE FREEZING BEFORE SIGNIFICANT PRECIPITATION REACHES THE
AREA LATE TONIGHT. DESPITE THE MODEL GUIDANCE...THERE MAY BE
LAYERS OF DRY AIR ALOFT WITH WET-BULB COOLING WHICH COULD SUPPORT
SLEET. WE BELIEVE ANY SLEET WOULD BE LIGHT AND WITH SURFACE
TEMPERATURES JUST ABOVE FREEZING...NO ACCUMULATION SHOULD OCCUR.
WE USED THE COOLER TEMPERATURE GUIDANCE TONIGHT BECAUSE OF THE
DRY AIR IN PLACE AND EVAPORATIVE COOLING ASSOCIATED WITH THE
MOISTURE INCREASE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS THROUGH MOST OF THE OVERNIGHT PERIOD THEN
DETERIORATING TO IFR AROUND 09Z.
HIGH PRESSURE ACROSS THE REGION WILL WEAKEN AND SHIFT INTO THE
ATLANTIC AS LOW PRESSURE ALONG THE NORTHWEST GULF COAST SHIFTS
NORTHEASTWARD. SCATTERED MID-HIGH LEVEL CLOUDS WILL BEGIN TO
LOWER TO 10-12 KFT AND THICKEN BY 00Z THIS EVENING. WITH MOISTURE
FLUX TO THE AREA AHEAD OF APPROACHING WEATHER SYSTEM
TONIGHT...CEILINGS WILL CONTINUE TO LOWER TO 3-4 KFT BY 04Z-06Z
TIME FRAME. LIGHT RAIN SHOULD SPREAD INTO THE AREA AROUND 08Z-09Z
AND CONTINUE SPREADING TOWARD THE NORTHEAST AS THE SURFACE LOW
APPROACHES. BY 10Z-12Z...WIDESPREAD RAINFALL IS EXPECTED AND
CONDITIONS SHOULD DETERIORATE RAPIDLY TO IFR. AT THE MORE
NORTHEAST TAF SITES LIKE CAE AND CUB...IFR CONDITIONS MAY BE
DELAYED AS LONG AS 14Z BUT CONDITIONS WILL ALSO DETERIORATE
RAPIDLY AT THOSE LOCATIONS WHEN THE RAIN MOVES IN. AFTER
14Z...WIDESPREAD IFR CONDITIONS AND VSBYS AT WESTERN TAF SITES OF
AGS AND DNL MAY LOWER TO BELOW 1 MILE IN RAIN AT TIMES. MAINLY
MODERATE RAIN ON TUESDAY BUT DUE TO INCREASING ISENTROPIC
LIFT...CANNOT RULE OUT SOME HEAVY RAIN ESPECIALLY AT THE WESTERN
TAF SITES. ALSO WITH INCREASING INSTABILITY ALOFT...A FEW ELEVATED
THUNDERSTORMS ARE POSSIBLE BUT CONFIDENCE WAS TOO LOW TO INCLUDE
IN THIS TAF PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT AS A LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE
SOUTHEASTERN STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
218 PM EST MON NOV 25 2013
.SYNOPSIS...
MOISTURE WILL OVERSPREAD THE FORECAST AREA TONIGHT AHEAD OF LOW
PRESSURE DEVELOPING ALONG THE GULF COAST. THE LOW WILL MOVE
NORTHEAST ACROSS THE OUR AREA TUESDAY AND TUESDAY NIGHT...BRINGING
WIDESPREAD RAIN. THE LOW WILL LIFT NORTHEAST OF THE REGION
WEDNESDAY WITH COLD AND DRY HIGH PRESSURE RETURNING THANKSGIVING
DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...HIGH PRESSURE WILL WEAKEN THIS AFTERNOON AS A
WEATHER SYSTEM DEVELOPS IN THE WESTERN GULF COAST STATES OF TEXAS
AND LOUISIANA. THE UPPER RIDGE AXIS OVER THE FA WILL SHIFT EAST
AND ALLOW HIGH AND MID LEVEL CLOUDS TO ENTER THE REGION FROM
THE WEST. STILL COOL AND DRY CONDITIONS IN THE LOWER LAYERS.
AFTERNOON HIGHS MAINLY IN THE MID TO UPPER 40S. A BIT WARMER
IN THE CSRA AND AGS MAY HIT 51 OR 52. LIGHT MAINLY EASTERLY
WINDS ARE EXPECTED. DEWPOINTS IN THE SINGLE DIGITS EARLY THIS
AFTERNOON SHOULD INCREASE TO 10-15 DEGREES BY LATE AFTERNOON
AS MOISTURE BEGINS TO ENTER AREA.
TONIGHT...THE LATEST WATER VAPOR IMAGERY SHOWED A DIFLUENT PATTERN
OVER THE WESTERN GULF OF MEXICO AND LOW PRESSURE IS DEVELOPING
ALONG THE GULF COAST. ALL MODELS INDICATE INCREASING ISENTROPIC
LIFT AHEAD OF THIS LOW WILL RESULT IN PRECIPITATION OVERSPREADING
THE FORECAST AREA FROM SOUTHWEST TO NORTHEAST TONIGHT. THE HRRR
PLUS SATELLITE AND RADAR TRENDS INDICATE THE PRECIPITATION WILL HOLD
OFF UNTIL LATE TONIGHT. THE 1600 GMT HRRR INDICATED AREAS OF LIGHT
PRECIPITATION DEVELOPING IN THE WEST PART OF THE FORECAST AREA
AROUND MIDNIGHT...WITH THE BULK OF THE PRECIPITATION ABOUT TO MOVE
INTO THE WEST PART OF THE AREA AT 200 AM. USED THIS GUIDANCE FOR
THE TIMING.
THE MODELS INDICATE ENOUGH WARMING SHOULD OCCUR FOR ALL LIQUID
PRECIPITATION. ALL SREF MEMBERS KEEP THE SURFACE TEMPERATURE ABOVE
FREEZING LATE TONIGHT...EVEN IN THE NORTH PART. FREEZING RAIN IS
NOT IMPOSSIBLE IN THE EXTREME NORTH SECTION...BUT BELIEVE
PRECIPITATION WILL BE LIGHT AT THE ONSET LIMITING WET-BULB
COOLING. ALSO...THE NAM AND GFS SHOW SURFACE WET-BULB TEMPERATURES
RISING ABOVE FREEZING BEFORE SIGNIFICANT PRECIPITATION REACHES THE
AREA LATE TONIGHT. DESPITE THE MODEL GUIDANCE...THERE MAY BE
LAYERS OF DRY AIR ALOFT WITH WET-BULB COOLING WHICH COULD SUPPORT
SLEET. WE BELIEVE ANY SLEET WOULD BE LIGHT AND WITH SURFACE
TEMPERATURES JUST ABOVE FREEZING...NO ACCUMULATION SHOULD OCCUR.
WE USED THE COOLER TEMPERATURE GUIDANCE TONIGHT BECAUSE OF THE
DRY AIR IN PLACE AND EVAPORATIVE COOLING ASSOCIATED WITH THE
MOISTURE INCREASE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
TUESDAY THROUGH WEDNESDAY...THE NAM AND GFS INDICATE THE BULK OF
THE RAINFALL WILL OCCUR DURING THE TUESDAY AND TUESDAY NIGHT TIME
FRAME WITH STRONG ISENTROPIC LIFT AND APPROACHING H5 SHORTWAVE
TROUGH. THE NAM...GFS AND SREF MEAN SUPPORT TOTAL RAINFALL FROM
1.5 TO AROUND 2.0 INCHES. THE NAM SHOWS CROSS TOTALS NEAR 25
TUESDAY AND TUESDAY NIGHT...SO A FEW ELEVATED THUNDERSTORMS MAY
OCCUR. THE SURFACE LOW WILL BE NORTHEAST OF THE AREA WITH THE
UPPER TROUGH OVERHEAD WEDNESDAY. WE MAY HAVE LINGERING MORNING
RAIN. STRONG COLD ADVECTION AND DRY AIR WILL POUR INTO THE AREA
WEDNESDAY AFTERNOON.
THE NAM LI-PATTERN INDICATES A WEDGE-TYPE PATTERN TUESDAY. WE
LEANED TOWARD THE IN-HOUSE WEDGE SCHEME FOR THE HIGH TEMPERATURE
FORECAST. EXPECT A NEAR STEADY TEMPERATURE TUESDAY NIGHT. USED
THE COLDER TEMPERATURE GUIDANCE WEDNESDAY BECAUSE OF LINGERING
CLOUDINESS AND A SHARP UPPER TROUGH OVER OUR AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GFS AND ECMWF ARE IN GOOD AGREEMENT SHOWING DRY HIGH PRESSURE
DOMINATING DURING MUCH OF THE THE MEDIUM-RANGE PERIOD. AN ONSHORE
FLOW AND WARM FRONT MAY SUPPORT RAIN MONDAY. BELOW NORMAL
TEMPERATURES SHOULD CONTINUE THROUGH SUNDAY. THE GFS...ECMWF...EKD MOS
PLUS GFS ENSEMBLE MEAN SUPPORT TEMPERATURES AROUND 10 DEGREES
BELOW NORMAL THROUGH SUNDAY WITH NORMAL TEMPERATURES MONDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
HIGH PRESSURE ACROSS THE REGION WILL WEAKEN THIS AFTERNOON
AS LOW PRESSURE DEVELOPS ALONG THE NORTHWEST GULF COAST THIS
EVENING. VFR CONDITIONS THIS AFTERNOON THROUGH MOST OF THE
OVERNIGHT PERIOD. SCATTERED MID-HIGH LEVEL CLOUDS THIS AFTERNOON
WILL BEGIN TO LOWER AND THICKEN BY 00Z THIS EVENING. CEILINGS
LOWERING TO 10-12 KFT. WITH MOISTURE FLUX TO THE AREA AHEAD OF
APPROACHING WEATHER SYSTEM TONIGHT...CEILINGS TO CONTINUE LOWER
TO 3-4 KFT BY 04Z-06Z TIME FRAME. LIGHT RAIN SHOULD SPREAD INTO
THE AREA AROUND 08Z-09Z AND CONTINUE SPREADING TOWARD THE
NORTHEAST AS THE SURFACE LOW APPROACHES. BY 10Z-12Z...WIDESPREAD
RAINFALL IS EXPECTED AND CONDITIONS SHOULD DETERIORATE RAPIDLY TO
IFR. AT THE MORE NORTHEAST TAF SITES LIKE CAE AND CUB...IFR
CONDITIONS MAY BE DELAYED AS LONG AS 14Z BUT CONDITIONS WILL ALSO
DETERIORATE RAPIDLY AS THOSE LOCATIONS WHEN THE RAIN MOVES IN.
AFTER 14Z...WIDESPREAD IFR CONDITIONS AND VSBYS AT WESTERN TAF
SITES OF AGS AND DNL MAY LOWER TO BELOW 1 MILE IN RAIN AT TIMES.
MAINLY MODERATE RAIN ON TUESDAY BUT DUE TO INCREASING ISENTROPIC
LIFT...CANNOT RULE OUT SOME HEAVY RAIN ESPECIALLY AT THE WESTERN
TAF SITES. ALSO WITH INCREASING INSTABILITY ALOFT...A FEW ELEVATED
THUNDERSTORMS ARE POSSIBLE BUT CONFIDENCE WAS TOO LOW TO INCLUDE
IN THIS TAF PACKAGE.
EXTENDED AVIATION OUTLOOK...AN EXTENDED PERIOD OF CIG/VSBY
RESTRICTIONS ARE POSSIBLE TUESDAY AFTERNOON THROUGH WEDNESDAY
NIGHT AS A LOW PRESSURE SYSTEM FROM THE GULF OF MEX CROSSES THE
SOUTHEASTERN STATES.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
208 PM CST MON NOV 25 2013
.DISCUSSION...
1040 AM CST
FOR MORNING UPDATE...
HAVE BUMPED SNOWFALL AMOUNTS JUST A BIT...TO AROUND 1 INCH...ALONG
THE WI/IL STATE LINE. OTHERWISE...ONLY MINOR TWEAKS TO NEAR TERM OF
GOING FORECAST.
MORNING WATER VAPOR IMAGERY AND 12Z UPPER AIR ANALYSIS DEPICT FAIRLY
STRONG MID-LEVEL SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER
MIDWEST AND NORTHERN GREAT LAKES REGION. MAIN AREA OF SURFACE LOW
PRESSURE WAS NORTH OF LAKE SUPERIOR...WHILE AN AREA OF ENHANCED LOW
LEVEL WARM ADVECTION WAS OCCURRING ACROSS IOWA...SOUTHEAST
MINNESOTA...WISCONSIN AND FAR NORTH/NORTHWEST ILLINOIS. ISENTROPIC
ASCENT AND MOISTURE ADVECTION WAS PRODUCING TOP-DOWN SATURATION IN A
NARROW CORRIDOR FROM DSM-DBQ-MKE...WITH LIGHT SNOW LOWERING
VISIBILITY TO 1/2 MILE IN SOME SPOTS ACROSS FAR SOUTHERN WI.
CONSIDERABLE DRY AIR BELOW 800-700 MB IN DVN AND ILX 12Z...WHICH
INDICATES FORCING WILL HAVE TO WORK TO SATURATE LOWER LEVELS ACROSS
IL/IN TODAY. WITH STRONGEST WARM ADVECTION AND JET DYNAMICS EXPECTED
TO PROVIDE THE BEST FORCING THIS MORNING...BAND OF SNOW SHOULD HAVE
A HARDER TIME PRODUCING MODERATE SNOW FARTHER SOUTHEAST INTO IL AND
NORTHWEST IN.
A FEW REPORTS FROM NORTHEAST IA OF 3-5 INCH SNOWFALL AMOUNTS WITH
INITIAL STRONG BANDING EARLY THIS MORNING...THOUGH WITH FORCING
WEAKENING SOMEWHAT WITH TIME AND DRY LOW-LEVELS TO OVERCOME WOULD
EXPECT AMOUNTS TO TAPER QUICKLY INTO THE LOT CWA. BASED ON RADAR
TRENDS THROUGH THE MORNING...AND SOME WEB CAM IMAGERY FROM AREAS
ALONG AND NORTH OF RFD-UGN WHERE A FEW TENTHS OF ACCUM ALREADY HAS
OCCURRED...HAVE BUMPED SNOWFALL AMOUNTS A BIT TO AROUND AN INCH
ACROSS NORTHERN PARTS OF THE NORTHERN TIER COUNTIES...TO LESS THAN A
HALF INCH FROM ROUGHLY I-88 SOUTH.
RATZER
//PREV DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY SOUTHWEST WINDS THROUGH LATE AFTERNOON.
* PERIODS OF LIGHT SNOW THROUGH LATE AFTERNOON TO EARLY EVENING
WITH PERIODS OF 3-4SM VIS.
* OCNL SMALL AREAS OF HEAVIER SNOW WILL RIPPLE THROUGH THE GENERAL
SNOW BAND DROPPING VIS TO 1-2SM FOR THE NEXT 2 HRS.
* MVFR CIGS TO PERSIST UNTIL LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON
IMPACTS OF LIGHT SNOW AS WELL AS GUSTY SWLY WINDS.
AT THE CURRENT TIME...A BAND OF LIGHT WARM ADVECTION SNOW IS
SAGGING SWD THROUGH NRN IL AND WILL SOON MOVE INTO NWRN INDIANA.
SOUTH OF THE BAND...SCT UNORGANIZED AREAS OF LIGHT SNOW ARE ALSO
MOVING THROUGH THE AREA. THE LATEST RADAR TRENDS INDICATE THAT THE
SNOW BAND IS BECOMING A LITTLE LESS ORGANIZED AS IT SAGS TO THE
SOUTH...BUT STILL EXPECT A PERIOD OF SNOW TO IMPACT THE TERMINALS.
WHILE THE SNOW IS RELATIVELY LIGHT AND ACCUMULATIONS GENERALLY NOT
A MAJOR CONCERN AT THE TERMINALS...THE BIGGEST IMPACT WILL BE ON
VISIBILITY DUE TO THE STRONG...GUSTY WINDS. SO...EXPECT A PERIOD
OF ABOUT 2 HRS WHERE THE SNOWFALL RATE SILL BE HIGH
ENOUGH...COMBINED WITH THE STRONG WINDS TO REDUCE VISIBILITY TO
1-2SM. AND THE MAIN BAND OF SNOW SAGS SOUTH OF THE TERMINALS INTO
CNTRL IL/IN...THERE SHOULD STILL BE SOME LIGHT SNOW FALLING...BUT
GENERALLY VISIBILITY SHOULD RETURN TO VFR LEVELS. HOWEVER...MVFR
CIGS SHOULD PERSIST WELL INTO THE EVENING AND LATE NIGHT HOURS AS
COOLER AIR WRAPS AROUND A DEEP LOW PRESSURE SYSTEM TRACKING
THROUGH THE UPPER GREAT LAKES. WITH THE AREA BETWEEN AN
APPROACHING COLD FRONT ASSOCIATED WITH THE LOW TO THE NORTH AND
HIGH PRESSURE SITTING OVER THE MID ATLANTIC REGION...A SWLY
GRADIENT WILL REMAIN IN PLACE UNTIL THE FRONT SWEEPS THROUGH THE
REGION. LATEST MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL MOVE
THROUGH NRN IL/IN BY LATE TOMORROW MORNING...AT WHICH TIME WINDS
WILL QUICKLY SHIFT FROM SWLY TO NWLY.
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE DURATION OF MVFR AND IFR VIS ASSOCIATED
WITH WIND DRIVEN SNOW.
* MEDIUM CONFIDENCE IN CIG TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
208 PM...LOW PRESSURE OVER EASTERN ONTARIO WILL MOVE INTO QUEBEC
TONIGHT AS IT SLOWLY WEAKENS...ALLOWING THE GRADIENT OVER LAKE
MICHIGAN TO SLOWLY RELAX WITH GALES STILL POSSIBLE EARLY THIS
EVENING. SPEEDS WILL DIMINISH INTO THE 15-20KT RANGE LATER TONIGHT
INTO TUESDAY MORNING. A TRAILING COLD FRONT FROM THE LOW MOVING
INTO QUEBEC WILL MOVE ACROSS THE LAKE TUESDAY AFTERNOON...WITH
ANOTHER WEAKER LOW DEVELOPING ALONG THE FRONT OVER LAKE SUPERIOR
TONIGHT. ONCE THIS FRONT PASSES EAST OF THE LAKE...WINDS WILL
SHIFT TO THE NORTHWEST AND STEADILY INCREASE AS THE GRADIENT
TIGHTENS IN RESPONSE TO STRONG HIGH PRESSURE MOVE SOUTH ACROSS
THE PLAINS TUESDAY AFTERNOON INTO TUESDAY NIGHT...COMBINED WITH A
STRONG LOW MOVING NORTH ACROSS THE EASTERN SEABOARD. ITS POSSIBLE
FOR A SHORTER PERIOD OF GALES ON THE NORTH HALF OF THE LAKE LATE
TUESDAY AFTERNOON INTO TUESDAY EVENING...BUT A MORE PROLONGED
PERIOD OF LOW END GALES APPEARS POSSIBLE OVER THE SOUTH HALF OF
THE LAKE TUESDAY NIGHT INTO WEDNESDAY MORNING WHEN THE GRADIENT
SHOULD BE THE TIGHTEST. THE LOW MOVING UP THE EAST COAST WILL
CONTINUE TO DEEPEN AS IT MOVES INTO QUEBEC WEDNESDAY NIGHT WITH
THE HIGH SPREADING SOUTH INTO THE SOUTHERN PLAINS AND GULF COAST
STATES. A WEAKER RIDGE WILL PASS ACROSS THE LAKE WITH SPEEDS
SLOWLY DIMINISHING WEDNESDAY AFTERNOON THROUGH THURSDAY MORNING.
THE HIGH WILL BECOME SPRAWLING ACROSS THE EASTERN HALF OR TWO
THIRDS OF THE U.S. THURSDAY NIGHT INTO FRIDAY WITH PRIMARILY
WESTERLY FLOW FLOPPING AROUND SOUTHEAST FRIDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
145 PM CST MON NOV 25 2013
.DISCUSSION...
1040 AM CST
FOR MORNING UPDATE...
HAVE BUMPED SNOWFALL AMOUNTS JUST A BIT...TO AROUND 1 INCH...ALONG
THE WI/IL STATE LINE. OTHERWISE...ONLY MINOR TWEAKS TO NEAR TERM OF
GOING FORECAST.
MORNING WATER VAPOR IMAGERY AND 12Z UPPER AIR ANALYSIS DEPICT FAIRLY
STRONG MID-LEVEL SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER
MIDWEST AND NORTHERN GREAT LAKES REGION. MAIN AREA OF SURFACE LOW
PRESSURE WAS NORTH OF LAKE SUPERIOR...WHILE AN AREA OF ENHANCED LOW
LEVEL WARM ADVECTION WAS OCCURRING ACROSS IOWA...SOUTHEAST
MINNESOTA...WISCONSIN AND FAR NORTH/NORTHWEST ILLINOIS. ISENTROPIC
ASCENT AND MOISTURE ADVECTION WAS PRODUCING TOP-DOWN SATURATION IN A
NARROW CORRIDOR FROM DSM-DBQ-MKE...WITH LIGHT SNOW LOWERING
VISIBILITY TO 1/2 MILE IN SOME SPOTS ACROSS FAR SOUTHERN WI.
CONSIDERABLE DRY AIR BELOW 800-700 MB IN DVN AND ILX 12Z...WHICH
INDICATES FORCING WILL HAVE TO WORK TO SATURATE LOWER LEVELS ACROSS
IL/IN TODAY. WITH STRONGEST WARM ADVECTION AND JET DYNAMICS EXPECTED
TO PROVIDE THE BEST FORCING THIS MORNING...BAND OF SNOW SHOULD HAVE
A HARDER TIME PRODUCING MODERATE SNOW FARTHER SOUTHEAST INTO IL AND
NORTHWEST IN.
A FEW REPORTS FROM NORTHEAST IA OF 3-5 INCH SNOWFALL AMOUNTS WITH
INITIAL STRONG BANDING EARLY THIS MORNING...THOUGH WITH FORCING
WEAKENING SOMEWHAT WITH TIME AND DRY LOW-LEVELS TO OVERCOME WOULD
EXPECT AMOUNTS TO TAPER QUICKLY INTO THE LOT CWA. BASED ON RADAR
TRENDS THROUGH THE MORNING...AND SOME WEB CAM IMAGERY FROM AREAS
ALONG AND NORTH OF RFD-UGN WHERE A FEW TENTHS OF ACCUM ALREADY HAS
OCCURRED...HAVE BUMPED SNOWFALL AMOUNTS A BIT TO AROUND AN INCH
ACROSS NORTHERN PARTS OF THE NORTHERN TIER COUNTIES...TO LESS THAN A
HALF INCH FROM ROUGHLY I-88 SOUTH.
RATZER
//PREV DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* GUSTY SOUTHWEST WINDS THROUGH LATE AFTERNOON.
* PERIODS OF LIGHT SNOW THROUGH LATE AFTERNOON TO EARLY EVENING
WITH PERIODS OF 3-4SM VIS.
* OCNL SMALL AREAS OF HEAVIER SNOW WILL RIPPLE THROUGH THE GENERAL
SNOW BAND DROPPING VIS TO 1-2SM FOR THE NEXT 2 HRS.
* MVFR CIGS TO PERSIST UNTIL LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON
IMPACTS OF LIGHT SNOW AS WELL AS GUSTY SWLY WINDS.
AT THE CURRENT TIME...A BAND OF LIGHT WARM ADVECTION SNOW IS
SAGGING SWD THROUGH NRN IL AND WILL SOON MOVE INTO NWRN INDIANA.
SOUTH OF THE BAND...SCT UNORGANIZED AREAS OF LIGHT SNOW ARE ALSO
MOVING THROUGH THE AREA. THE LATEST RADAR TRENDS INDICATE THAT THE
SNOW BAND IS BECOMING A LITTLE LESS ORGANIZED AS IT SAGS TO THE
SOUTH...BUT STILL EXPECT A PERIOD OF SNOW TO IMPACT THE TERMINALS.
WHILE THE SNOW IS RELATIVELY LIGHT AND ACCUMULATIONS GENERALLY NOT
A MAJOR CONCERN AT THE TERMINALS...THE BIGGEST IMPACT WILL BE ON
VISIBILITY DUE TO THE STRONG...GUSTY WINDS. SO...EXPECT A PERIOD
OF ABOUT 2 HRS WHERE THE SNOWFALL RATE SILL BE HIGH
ENOUGH...COMBINED WITH THE STRONG WINDS TO REDUCE VISIBILITY TO
1-2SM. AND THE MAIN BAND OF SNOW SAGS SOUTH OF THE TERMINALS INTO
CNTRL IL/IN...THERE SHOULD STILL BE SOME LIGHT SNOW FALLING...BUT
GENERALLY VISIBILITY SHOULD RETURN TO VFR LEVELS. HOWEVER...MVFR
CIGS SHOULD PERSIST WELL INTO THE EVENING AND LATE NIGHT HOURS AS
COOLER AIR WRAPS AROUND A DEEP LOW PRESSURE SYSTEM TRACKING
THROUGH THE UPPER GREAT LAKES. WITH THE AREA BETWEEN AN
APPROACHING COLD FRONT ASSOCIATED WITH THE LOW TO THE NORTH AND
HIGH PRESSURE SITTING OVER THE MID ATLANTIC REGION...A SWLY
GRADIENT WILL REMAIN IN PLACE UNTIL THE FRONT SWEEPS THROUGH THE
REGION. LATEST MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL MOVE
THROUGH NRN IL/IN BY LATE TOMORROW MORNING...AT WHICH TIME WINDS
WILL QUICKLY SHIFT FROM SWLY TO NWLY.
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* LOW TO MEDIUM CONFIDENCE DURATION OF MVFR AND IFR VIS ASSOCIATED
WITH WIND DRIVEN SNOW.
* MEDIUM CONFIDENCE IN CIG TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1142 AM CST MON NOV 25 2013
.DISCUSSION...
1040 AM CST
FOR MORNING UPDATE...
HAVE BUMPED SNOWFALL AMOUNTS JUST A BIT...TO AROUND 1 INCH...ALONG
THE WI/IL STATE LINE. OTHERWISE...ONLY MINOR TWEAKS TO NEAR TERM OF
GOING FORECAST.
MORNING WATER VAPOR IMAGERY AND 12Z UPPER AIR ANALYSIS DEPICT FAIRLY
STRONG MID-LEVEL SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER
MIDWEST AND NORTHERN GREAT LAKES REGION. MAIN AREA OF SURFACE LOW
PRESSURE WAS NORTH OF LAKE SUPERIOR...WHILE AN AREA OF ENHANCED LOW
LEVEL WARM ADVECTION WAS OCCURRING ACROSS IOWA...SOUTHEAST
MINNESOTA...WISCONSIN AND FAR NORTH/NORTHWEST ILLINOIS. ISENTROPIC
ASCENT AND MOISTURE ADVECTION WAS PRODUCING TOP-DOWN SATURATION IN A
NARROW CORRIDOR FROM DSM-DBQ-MKE...WITH LIGHT SNOW LOWERING
VISIBILITY TO 1/2 MILE IN SOME SPOTS ACROSS FAR SOUTHERN WI.
CONSIDERABLE DRY AIR BELOW 800-700 MB IN DVN AND ILX 12Z...WHICH
INDICATES FORCING WILL HAVE TO WORK TO SATURATE LOWER LEVELS ACROSS
IL/IN TODAY. WITH STRONGEST WARM ADVECTION AND JET DYNAMICS EXPECTED
TO PROVIDE THE BEST FORCING THIS MORNING...BAND OF SNOW SHOULD HAVE
A HARDER TIME PRODUCING MODERATE SNOW FARTHER SOUTHEAST INTO IL AND
NORTHWEST IN.
A FEW REPORTS FROM NORTHEAST IA OF 3-5 INCH SNOWFALL AMOUNTS WITH
INITIAL STRONG BANDING EARLY THIS MORNING...THOUGH WITH FORCING
WEAKENING SOMEWHAT WITH TIME AND DRY LOW-LEVELS TO OVERCOME WOULD
EXPECT AMOUNTS TO TAPER QUICKLY INTO THE LOT CWA. BASED ON RADAR
TRENDS THROUGH THE MORNING...AND SOME WEB CAM IMAGERY FROM AREAS
ALONG AND NORTH OF RFD-UGN WHERE A FEW TENTHS OF ACCUM ALREADY HAS
OCCURRED...HAVE BUMPED SNOWFALL AMOUNTS A BIT TO AROUND AN INCH
ACROSS NORTHERN PARTS OF THE NORTHERN TIER COUNTIES...TO LESS THAN A
HALF INCH FROM ROUGHLY I-88 SOUTH.
RATZER
//PREV DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* GUSTY SOUTHWEST WINDS THROUGH LATE AFTERNOON.
* PERIODS OF LIGHT SNOW THROUGH MID TO LATE AFTERNOON WITH
PERIODS OF MVFR TO IFR VIS AND MVFR CIGS LIKELY.
* MVFR CIGS TO PERSIST UNTIL LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERNS FOR THE REMAINDER OF THE AFTERNOON WILL FOCUS ON
IMPACTS OF LIGHT SNOW AS WELL AS GUSTY SWLY WINDS.
AT THE CURRENT TIME...A BAND OF LIGHT WARM ADVECTION SNOW IS
SAGGING SWD THROUGH NRN IL AND WILL SOON MOVE INTO NWRN INDIANA.
SOUTH OF THE BAND...SCT UNORGANIZED AREAS OF LIGHT SNOW ARE ALSO
MOVING THROUGH THE AREA. THE LATEST RADAR TRENDS INDICATE THAT THE
SNOW BAND IS BECOMING A LITTLE LESS ORGANIZED AS IT SAGS TO THE
SOUTH...BUT STILL EXPECT A PERIOD OF SNOW TO IMPACT THE TERMINALS.
WHILE THE SNOW IS RELATIVELY LIGHT AND ACCUMULATIONS GENERALLY NOT
A MAJOR CONCERN AT THE TERMINALS...THE BIGGEST IMPACT WILL BE ON
VISIBILITY DUE TO THE STRONG...GUSTY WINDS. SO...EXPECT A PERIOD
OF ABOUT 2 HRS WHERE THE SNOWFALL RATE SILL BE HIGH
ENOUGH...COMBINED WITH THE STRONG WINDS TO REDUCE VISIBILITY TO
1-2SM. AND THE MAIN BAND OF SNOW SAGS SOUTH OF THE TERMINALS INTO
CNTRL IL/IN...THERE SHOULD STILL BE SOME LIGHT SNOW FALLING...BUT
GENERALLY VISIBILITY SHOULD RETURN TO VFR LEVELS. HOWEVER...MVFR
CIGS SHOULD PERSIST WELL INTO THE EVENING AND LATE NIGHT HOURS AS
COOLER AIR WRAPS AROUND A DEEP LOW PRESSURE SYSTEM TRACKING
THROUGH THE UPPER GREAT LAKES. WITH THE AREA BETWEEN AN
APPROACHING COLD FRONT ASSOCIATED WITH THE LOW TO THE NORTH AND
HIGH PRESSURE SITTING OVER THE MID ATLANTIC REGION...A SWLY
GRADIENT WILL REMAIN IN PLACE UNTIL THE FRONT SWEEPS THROUGH THE
REGION. LATEST MODEL GUIDANCE SUGGESTS THAT THE FRONT WILL MOVE
THROUGH NRN IL/IN BY LATE TOMORROW MORNING...AT WHICH TIME WINDS
WILL QUICKLY SHIFT FROM SWLY TO NWLY.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN WIND TRENDS.
* MEDIUM CONFIDENCE DURATION OF MVFR AND IFR VIS ASSOCIATED WITH
WIND DRIVEN SNOW.
* MEDIUM TO HIGH CONFIDENCE IN CIG TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1040 AM CST MON NOV 25 2013
.DISCUSSION...
1040 AM CST
FOR MORNING UPDATE...
HAVE BUMPED SNOWFALL AMOUNTS JUST A BIT...TO AROUND 1 INCH...ALONG
THE WI/IL STATE LINE. OTHERWISE...ONLY MINOR TWEAKS TO NEAR TERM OF
GOING FORECAST.
MORNING WATER VAPOR IMAGERY AND 12Z UPPER AIR ANALYSIS DEPICT FAIRLY
STRONG MID-LEVEL SHORT WAVE TROUGH PROPAGATING ACROSS THE UPPER
MIDWEST AND NORTHERN GREAT LAKES REGION. MAIN AREA OF SURFACE LOW
PRESSURE WAS NORTH OF LAKE SUPERIOR...WHILE AN AREA OF ENHANCED LOW
LEVEL WARM ADVECTION WAS OCCURRING ACROSS IOWA...SOUTHEAST
MINNESOTA...WISCONSIN AND FAR NORTH/NORTHWEST ILLINOIS. ISENTROPIC
ASCENT AND MOISTURE ADVECTION WAS PRODUCING TOP-DOWN SATURATION IN A
NARROW CORRIDOR FROM DSM-DBQ-MKE...WITH LIGHT SNOW LOWERING
VISIBILITY TO 1/2 MILE IN SOME SPOTS ACROSS FAR SOUTHERN WI.
CONSIDERABLE DRY AIR BELOW 800-700 MB IN DVN AND ILX 12Z...WHICH
INDICATES FORCING WILL HAVE TO WORK TO SATURATE LOWER LEVELS ACROSS
IL/IN TODAY. WITH STRONGEST WARM ADVECTION AND JET DYNAMICS EXPECTED
TO PROVIDE THE BEST FORCING THIS MORNING...BAND OF SNOW SHOULD HAVE
A HARDER TIME PRODUCING MODERATE SNOW FARTHER SOUTHEAST INTO IL AND
NORTHWEST IN.
A FEW REPORTS FROM NORTHEAST IA OF 3-5 INCH SNOWFALL AMOUNTS WITH
INITIAL STRONG BANDING EARLY THIS MORNING...THOUGH WITH FORCING
WEAKENING SOMEWHAT WITH TIME AND DRY LOW-LEVELS TO OVERCOME WOULD
EXPECT AMOUNTS TO TAPER QUICKLY INTO THE LOT CWA. BASED ON RADAR
TRENDS THROUGH THE MORNING...AND SOME WEB CAM IMAGERY FROM AREAS
ALONG AND NORTH OF RFD-UGN WHERE A FEW TENTHS OF ACCUM ALREADY HAS
OCCURRED...HAVE BUMPED SNOWFALL AMOUNTS A BIT TO AROUND AN INCH
ACROSS NORTHERN PARTS OF THE NORTHERN TIER COUNTIES...TO LESS THAN A
HALF INCH FROM ROUGHLY I-88 SOUTH.
RATZER
&&
.PREV DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY SOUTHWEST WINDS TODAY.
* PERIODS OF LIGHT SNOW LIKELY BEGINNING EARLY AFTERNOON THROUGH
MID TO LATE AFTERNOON WITH PERIODS OF MVFR TO IFR VIS AND MVFR
CIGS POSSIBLE.
* HAVE PUSHED BACK TIMING OF SNOW ONSET BY AN HOUR IN THE TAFS.
KREIN
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS THIS MORNING CONTINUE TO REVOLVE AROUND
THE LIGHT SNOW EXPECTED ACROSS THE TERMINALS TODAY...ALONG WITH
THE STRONG SOUTHWESTERLY WINDS.
A STRONG PRESSURE GRADIENT IS SETTING UP ACROSS THE AREA EARLY THIS
MORNING IN ASSOCIATION WITH LOW PRESSURE ACROSS SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. THIS WILL CONTINUE TO
SUPPORT GUSTY WINDS THROUGH THE DAY. OVERALL WINDS STILL APPEAR TO
BE SOUTHWESTERLY AROUND 15 TO 17 KT WITH GUSTS UP TO 25 TO 28 KT.
THE OTHER CONCERN IS THAT FOR LIGHT SNOW. SNOW IS BEGINNING TO FALL
ACROSS PORTIONS OF IOWA AND INTO NORTHWESTERN ILLINOIS THIS
MORNING. THIS ACTIVITY WILL TAKE SOME TIME TO MOVE ACROSS
NORTHEASTERN ILLINOIS AS THE LOWER LEVELS ARE STILL FAIRLY DRY.
HOWEVER...WITH TIME THIS MORNING THE LOWER LEVELS WILL MOISTEN TO
ALLOW SNOW TO START AFTER 16 UTC AT THE EASTERN TERMINALS AND A
COUPLE HOURS SOONER AT KRFD. OVERALL...THIS WILL NOT BE A BIG
SNOW MAKER. THERE WILL BE ABOUT A 4 TO 6 HOUR WINDOW FOR SOME
LIGHT SNOW. VISIBILITIES IN THE SNOW COULD DROP DOWN AROUND 2
MILES FOR A PERIOD AND SOME LIGHT ACCUMULATIONS UP TO A HALF INCH
ARE POSSIBLE...ESPECIALLY AT KRFD. THE SNOW CHANCES WILL END QUICKLY
BY MID TO LATE AFTERNOON AS DRYER AIR FILTERS IN ACROSS THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WINDS.
* MEDIUM CONFIDENCE IN PERIODS OF LIGHT SNOW WITH MVFR TO IFR VIS
AND MVFR CIGS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 AM CST MON NOV 25 2013
.DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY SOUTHWEST WINDS TODAY.
* PERIODS OF LIGHT SNOW LIKELY BEGINNING EARLY AFTERNOON THROUGH
MID TO LATE AFTERNOON WITH PERIODS OF MVFR TO IFR VIS AND MVFR
CIGS POSSIBLE.
* HAVE PUSHED BACK TIMING OF SNOW ONSET BY AN HOUR IN THE TAFS.
KREIN
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS THIS MORNING CONTINUE TO REVOLVE AROUND
THE LIGHT SNOW EXPECTED ACROSS THE TERMINALS TODAY...ALONG WITH
THE STRONG SOUTHWESTERLY WINDS.
A STRONG PRESSURE GRADIENT IS SETTING UP ACROSS THE AREA EARLY THIS
MORNING IN ASSOCIATION WITH LOW PRESSURE ACROSS SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. THIS WILL CONTINUE TO
SUPPORT GUSTY WINDS THROUGH THE DAY. OVERALL WINDS STILL APPEAR TO
BE SOUTHWESTERLY AROUND 15 TO 17 KT WITH GUSTS UP TO 25 TO 28 KT.
THE OTHER CONCERN IS THAT FOR LIGHT SNOW. SNOW IS BEGINNING TO FALL
ACROSS PORTIONS OF IOWA AND INTO NORTHWESTERN ILLINOIS THIS
MORNING. THIS ACTIVITY WILL TAKE SOME TIME TO MOVE ACROSS
NORTHEASTERN ILLINOIS AS THE LOWER LEVELS ARE STILL FAIRLY DRY.
HOWEVER...WITH TIME THIS MORNING THE LOWER LEVELS WILL MOISTEN TO
ALLOW SNOW TO START AFTER 16 UTC AT THE EASTERN TERMINALS AND A
COUPLE HOURS SOONER AT KRFD. OVERALL...THIS WILL NOT BE A BIG
SNOW MAKER. THERE WILL BE ABOUT A 4 TO 6 HOUR WINDOW FOR SOME
LIGHT SNOW. VISIBILITIES IN THE SNOW COULD DROP DOWN AROUND 2
MILES FOR A PERIOD AND SOME LIGHT ACCUMULATIONS UP TO A HALF INCH
ARE POSSIBLE...ESPECIALLY AT KRFD. THE SNOW CHANCES WILL END QUICKLY
BY MID TO LATE AFTERNOON AS DRYER AIR FILTERS IN ACROSS THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WINDS.
* MEDIUM CONFIDENCE IN PERIODS OF LIGHT SNOW WITH MVFR TO IFR VIS
AND MVFR CIGS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
804 AM CST MON NOV 25 2013
.DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* GUSTY SOUTHWEST WINDS TODAY.
* PERIODS OF LIGHT SNOW LIKELY BEGINNING ARND 17 UTC THROUGH MID
AFTERNOON...PERIODS OF MVFR TO IFR VIS AND MVFR CIGS POSSIBLE.
KREIN
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS THIS MORNING CONTINUE TO REVOLVE AROUND
THE LIGHT SNOW EXPECTED ACROSS THE TERMINALS TODAY...ALONG WITH
THE STRONG SOUTHWESTERLY WINDS.
A STRONG PRESSURE GRADIENT IS SETTING UP ACROSS THE AREA EARLY THIS
MORNING IN ASSOCIATION WITH LOW PRESSURE ACROSS SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. THIS WILL CONTINUE TO
SUPPORT GUSTY WINDS THROUGH THE DAY. OVERALL WINDS STILL APPEAR TO
BE SOUTHWESTERLY AROUND 15 TO 17 KT WITH GUSTS UP TO 25 TO 28 KT.
THE OTHER CONCERN IS THAT FOR LIGHT SNOW. SNOW IS BEGINNING TO FALL
ACROSS PORTIONS OF IOWA AND INTO NORTHWESTERN ILLINOIS THIS
MORNING. THIS ACTIVITY WILL TAKE SOME TIME TO MOVE ACROSS
NORTHEASTERN ILLINOIS AS THE LOWER LEVELS ARE STILL FAIRLY DRY.
HOWEVER...WITH TIME THIS MORNING THE LOWER LEVELS WILL MOISTEN TO
ALLOW SNOW TO START AFTER 16 UTC AT THE EASTERN TERMINALS AND A
COUPLE HOURS SOONER AT KRFD. OVERALL...THIS WILL NOT BE A BIG
SNOW MAKER. THERE WILL BE ABOUT A 4 TO 6 HOUR WINDOW FOR SOME
LIGHT SNOW. VISIBILITIES IN THE SNOW COULD DROP DOWN AROUND 2
MILES FOR A PERIOD AND SOME LIGHT ACCUMULATIONS UP TO A HALF INCH
ARE POSSIBLE...ESPECIALLY AT KRFD. THE SNOW CHANCES WILL END QUICKLY
BY MID TO LATE AFTERNOON AS DRYER AIR FILTERS IN ACROSS THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN WINDS.
* MEDIUM TO HIGH CONFIDENCE IN PERIODS OF LIGHT SNOW WITH MVFR TO
IFR VIS AND MVFR CIGS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
545 AM CST MON NOV 25 2013
.DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* GUSTY SOUTHWEST WINDS TODAY.
* PERIODS OF LIGHT SNOW LIKELY AFTER 16-17 UTC THROUGH MID
AFTERNOON...PERIODS OF MVFR TO IFR VIS POSSIBLE.
KJB
//DISCUSSION...UPDATED 12Z...
THE MAIN FORECAST CONCERNS THIS MORNING CONTINUE TO REVOLVE AROUND
THE LIGHT SNOW EXPECTED ACROSS THE TERMINALS TODAY...ALONG WITH
THE STRONG SOUTHWESTERLY WINDS.
A STRONG PRESSURE GRADIENT IS SETTING UP ACROSS THE AREA EARLY THIS
MORNING IN ASSOCIATION WITH LOW PRESSURE ACROSS SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. THIS WILL CONTINUE TO
SUPPORT GUSTY WINDS THROUGH THE DAY. OVERALL WINDS STILL APPEAR TO
BE SOUTHWESTERLY AROUND 15 TO 17 KT WITH GUSTS UP TO 25 TO 28 KT.
THE OTHER CONCERN IS THAT FOR LIGHT SNOW. SNOW IS BEGINNING TO FALL
ACROSS PORTIONS OF IOWA AND INTO NORTHWESTERN ILLINOIS THIS
MORNING. THIS ACTIVITY WILL TAKE SOME TIME TO MOVE ACROSS
NORTHEASTERN ILLINOIS AS THE LOWER LEVELS ARE STILL FAIRLY DRY.
HOWEVER...WITH TIME THIS MORNING THE LOWER LEVELS WILL MOISTEN TO
ALLOW SNOW TO START AFTER 16 UTC AT THE EASTERN TERMINALS AND A
COUPLE HOURS SOONER AT KRFD. OVERALL...THIS WILL NOT BE A BIG
SNOW MAKER. THERE WILL BE ABOUT A 4 TO 6 HOUR WINDOW FOR SOME
LIGHT SNOW. VISIBILITIES IN THE SNOW COULD DROP DOWN AROUND 2
MILES FOR A PERIOD AND SOME LIGHT ACCUMULATIONS UP TO A HALF INCH
ARE POSSIBLE...ESPECIALLY AT KRFD. THE SNOW CHANCES WILL END QUICKLY
BY MID TO LATE AFTERNOON AS DRYER AIR FILTERS IN ACROSS THE AREA.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN WINDS.
* MEDIUM-HIGH CONFIDENCE IN PERIODS OF LIGHT SNOW WITH MVFR TO IFR VIS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...FLURRIES IN THE EVENING WITH MVFR CIGS LIFTING TO
VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
SUNDAY...MVFR CIGS PSBL
KJB
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
323 AM CST MON NOV 25 2013
.DISCUSSION...
323 AM CST
WITH NOVEMBER LOOKING TO FINISH WITH CONTINUED BELOW NORMAL
TEMPERATURES DURING ITS FINAL WEEK WITH LITTLE IN THE WAY OF SHARP
THERMAL CHANGES...THE PRIMARY FOCUS OF THE FORECAST WAS ON THE LIGHT
SNOW EVENT TODAY AND THEN THE LAKE EFFECT SNOW POTENTIAL INTO
NORTHWEST INDIANA TUESDAY NIGHT AND WEDNESDAY.
SOMEWHAT SPLIT UPPER FLOW IS IN PLACE ACROSS THE CENTRAL U.S. THIS
MONDAY WITH A QUICKLY-MOVING TROUGH ACROSS ONTARIO DIVING INTO THE
GREAT LAKES BY AFTERNOON...AND A CLOSED LOW ACROSS THE TEXAS
PANHANDLE BRINGING RARE NOVEMBER WINTER WEATHER HEADLINES TO THE
SOUTHERN PLAINS. OUR FORECAST AREA BASICALLY FALLS BETWEEN THESE TWO
SYSTEMS TODAY AND AS A RESULT THERE IS A VOID OF ANY OVERLY STRONG
FORCING OVERHEAD. ISENTROPIC ASCENT AND SATURATION WITHIN THE WSW
FLOW ALOFT THIS MORNING LOOKS TO BE THE PRIMARY CONTRIBUTOR TO
PRECIPITATION GENERATION...ALTHOUGH DRY LOW-LEVELS MAY KEEP IT
FLURRIES THROUGH MID TO LATE MORNING OVER CHICAGO. AN AXIS OF
FRONTOGENESIS CENTERED TO THE NORTHWEST OF THE AREA FROM EASTERN IA
INTO SOUTHERN WI THROUGH ~10 AM ON THE RAP AND LOCAL ARW MAY RESULT
IN BETTER SNOWFALL CLIPPING THE ROCKFORD AREA THIS MORNING...AND
CONCEIVABLY COULD SEE AN INCH BECAUSE OF THAT BUT THAT WOULD SEEM
THE MAXIMUM. AS THE SUBTLE FORCING AND MID-LEVEL SATURATION EVOLVES
EAST INTO THE AFTERNOON...PERIODS OF LIGHT SNOW WILL LIKELY RESULT
IN ONE HALF INCH OR LESS FOR MOST COMMUNITIES...AND NAMELY NORTH OF
I-80. WHILE NOT THE MOST IDEAL SYNOPTIC SETUP FOR FREEZING
DRIZZLE...THERE ARE SOME SIGNS ON GUIDANCE THAT AS ICE INTRODUCTION
IS LOST DURING THE MID TO LATE AFTERNOON THAT THERE MAY BE A BRIEF
WINDOW FOR THIS. ASCENT LOOKS WEAK AND CLOUD BASES LOOK HIGH FOR
THAT TO OCCUR THOUGH...SO CONTINUE TO NOT MENTION IN FORECAST.
THE AMOUNT OF CLOUD COVER TODAY WILL ONLY ALLOW TEMPERATURES TO RISE
BY ADVECTION...AND THAT WILL BE MEAGER AT THE SURFACE. SO MAINTAIN
HIGHS MAINLY IN THE LOWER 30S...WHICH WOULD RESULT IN THE THIRD
STRAIGHT DAY OF DOUBLE DIGIT DEPARTURES BELOW NORMAL.
A SECOND MORE ROBUST NORTHERN STREAM WAVE...THAT ACTUALLY LOOKS TO
BE A CLOSED SUB 520DM H5 LOW...WILL DROP INTO THE GREAT LAKES ON
TUESDAY. A FAIRLY DEEP PV ANOMALY IS SEEN WITH THIS ALONG WITH H5
TEMPS DOWN TO NEAR -30C...WHICH COME BARRELING INTO THE FORECAST
AREA BY LATE AFTERNOON INTO THE EVE TUESDAY ON THE GUIDANCE SUITE.
AN ASSOCIATED SURFACE COLD FRONT LOOKS TO STEEPEN LAPSE RATES AND
COULD SUPPORT SOME SNOW SHOWERS. CERTAINLY SOME FLURRIES LOOK TO BE
PRESENT INTO TUESDAY NIGHT. LOWS THAT NIGHT LOOK TO RETURN TO THE
MID AND POSSIBLY EVEN LOWER TEENS IN OUTLYING LOCATIONS.
MORE OF A CONCERN IS TURNING TO A POTENTIAL PLOWABLE SNOW FROM LAKE
EFFECT GENERATION INTO NORTHWEST INDIANA TUESDAY NIGHT INTO THE
BUSIEST TRAVEL DAY OF THE YEAR ON WEDNESDAY. THERE REMAINS MODEL
DIFFERENCES ON HOW QUICKLY THE AFOREMENTIONED SOUTHERN PLAINS UPPER
LOW AND THIS GREAT LAKES LOW PHASE. BUT OVERALL THE FLOW ACROSS LAKE
MI SHOULD BECOME STIFF AND NORTHERLY BY LATER TUESDAY NIGHT. THERE
ARE EVEN SIGNS ON SOME HIGH RESOLUTION MODELS...INCLUDING OUR LOCAL
ARW...OF MESO-LOW DEVELOPMENT TRANSLATING SOUTH ACROSS THE LAKE ON
TUESDAY NIGHT. CONFIDENCE ON SUCH A FEATURE IS LOW AT THIS
POINT...AS IS WHETHER THERE WILL EXIST A FOCUSED BAND OR JUST
WIDESPREAD SHOWERS OFF THE LAKE. BUT CONFIDENCE IS HIGH THERE WILL
BE AT LEAST SNOW SHOWERS INTO NORTHWEST INDIANA GIVE THE FORECAST
TRAJECTORIES...STEEP LOW-LEVEL LAPSE RATES...LAKE-INDUCED CAPE OF
AROUND 500 J/KG...AND EQUILIBRIUM LEVELS FORECAST AROUND 9000 FT.
THESE INDICES ACTUALLY INDICATE SOMEWHERE COULD GET A ROBUST SNOW
EVENT WITH HEAVY RATES WHICH WOULD IMPACT WEDNESDAY TRAVEL. IN
ADDITION...USING THE CIPS ANALOGS INDICATES A FAIRLY STRONG
CORRELATED EVENT FOR 850MB TEMPERATURES AND LOW-LEVEL WIND FLOW ON
11/21/08 AND THAT PRODUCED OVER 8 INCHES JUST EAST OF THE AREA. AT
THIS TIME HAVE CONTINUED THE TREND OF PREVIOUS SHIFT IN INCREASING
POPS ACROSS PORTER AND EASTERN LAKE COUNTIES.
BEYOND THERE WAS LITTLE CHANGE TO THE FORECAST AS THE HOLIDAY ITSELF
LOOKS QUIET ACROSS THE AREA WITH GRADUALLY BUILDING HEIGHTS AND
SURFACE HIGH PRESSURE. A QUASI-ZONAL PATTERN IS FAVORED ON LONG
RANGE DETERMINISTIC MODELS AND ENSEMBLES...WHICH WOULD FAVOR A
GRADUAL MODERATION TO NEAR NORMAL FOR THE FIRST DAY OF
METEOROLOGICAL WINTER ON SUNDAY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* GUSTY SOUTHWEST WINDS TODAY.
* PERIODS OF LIGHT SNOW LIKELY AFTER 17 UTC THROUGH MID
AFTERNOON...PERIODS OF MVFR TO IFR VIS POSSIBLE.
KJB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERNS THIS MORNING REVOLVE AROUND THE LIGHT
SNOW EXPECTED ACROSS THE TERMINALS TODAY...ALONG WITH THE STRONG
SOUTHWESTERLY WINDS.
A STRONG PRESSURE GRADIENT IS SETTING UP ACROSS THE AREA EARLY THIS
MORNING IN ASSOCIATION WITH LOW PRESSURE ACROSS SOUTHERN ONTARIO AND
HIGH PRESSURE ACROSS THE SOUTHEASTERN CONUS. THIS WILL SUPPORT SOME
GUSTY WINDS TODAY. IN FACT...WINDS ARE ALREADY BEGINNING TO GUST UP
AROUND 20 KT AT ORD EARLY THIS MORNING. OVERALL EXPECTED
SOUTHWESTERLY WINDS AROUND 15 TO 17 KT WITH GUSTS UP TO 25 TO 28 KT
AFTER DAYBREAK TODAY.
THE OTHER CONCERN IS THAT FOR LIGHT SNOW. THESE STRONG SOUTHWEST
WINDS ARE EXPECTED TO TRANSPORT JUST ENOUGH MOISTURE ACROSS THE AREA
TO LEAD TO SOME LIGHT SNOW AS AN UPPER LEVEL DISTURBANCE TRACKS
ACROSS SOUTHERN WISCONSIN TODAY. OVERALL...THIS WILL NOT BE A BIG
SYSTEM...BUT LIGHT SNOW WILL LIKELY ONSET BY EARLY TO MID MORNING AR
KRFD AND BY MID MORNING ACROSS THE EASTERN TAF SITES. ONCE IT BEGINS
THERE WILL BE ABOUT A 4 TO 6 HOUR WINDOW FOR SOME LIGHT SNOW.
VISIBILITIES IN THE SNOW COULD DROP DOWN AROUND 2 MILES FOR A PERIOD
AND SOME LIGHT ACCUMULATIONS AROUND A HALF INCH ARE POSSIBLE. THE
SNOW CHANCES WILL END QUICKLY BY MID TO LATE AFTERNOON AS DRYER AIR
FILTERS IN ACROSS THE AREA. I HAVE OPTED TO REMOVE THE MENTION OF
-FZDZ AS IT APPEARS THAT ALTHOUGH THE MOISTURE WILL BE VOID IN THE
FAVORABLE AREAS FOR SNOW GROWTH...IT ALSO APPEARS THAT CIGS WILL BE
TOO HIGH TO SUPPORT ANY PRECIP ONCE THE SNOW ENDS.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE IN WINDS.
* MEDIUM-HIGH CONFIDENCE IN PERIODS OF LIGHT SNOW WITH MVFR TO IFR VIS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...FLURRIES WITH MVFR CIGS LIFTING TO VFR.
WEDNESDAY...LAKE EFFECT MVFR CIGS PSBL.
THURSDAY AND FRIDAY...VFR.
SATURDAY...MVFR CIGS PSBL OVERNIGHT.
JEE
&&
.MARINE...
206 AM CST
A VERY ACTIVE WEATHER PATTERN WILL CONTINUE ACROSS THE GREAT LAKES
THROUGH MID WEEK. THE CURRENT GALE EVENT IS WELL UNDERWAY WITH
SEVERAL REPORTS OF 40+ KT WINDS...ESPECIALLY ACROSS THE NORTHERN
HALF OF THE LAKE. THESE GALES WILL CONTINUE THROUGH AT LEAST THE MID
AFTERNOON HOURS TODAY AS A AN AREA OF LOW PRESSURE TRACKS EASTWARD
ACROSS SOUTHERN ONTARIO. THE WINDS WILL GRADUALLY ABATE INTO THIS
EVENING. THE CURRENT GALE HEADLINE MAY BE ALOUD TO EXPIRE A FEW
HOURS EARLIER THAN THE CURRENT 9 PM DEADLINE. HOWEVER...AT THIS
POINT I WILL LEAVE THE HEADLINE TIMING ALONE.
THE NEXT ISSUE WILL BE LATER TUESDAY THROUGH MUCH OF WEDNESDAY. A
STRONG STORM SYSTEM IS EXPECTED TO MOVE UP THE EAST COAST DURING
THIS TIME...AND AS HIGH PRESSURE BUILDS IN ACROSS THE MISSOURI
VALLEY CONDITIONS WILL BECOME FAVORABLE FOR A PERIOD OF NORTHERLY
GALES UP TO 35 TO 40 KT. THIS LOOKS TO BE THE MOST PRONOUNCED ACROSS
SOUTHERN LAKE MICHIGAN...AND ANY LAKE EFFECT BANDS OF SNOW THAT
DEVELOP DURING THIS TIME COULD LEAD ALSO EVEN LEAD TO SOME LOCALLY
HIGH WINDS IN EXCESS OF 40 KT. IT APPEARS TO BE A GOOD BET THAT A
GALE HEADLINE WILL BE NEEDED DURING THIS TIME. I THREW AROUND THE
IDEA OF HOSTING A GALE WATCH FOR THIS PERIOD...BUT DUE TO THE FACT
IT IS STILL FAR ENOUGH OUT...I HAVE DECIDED TO LET THE CURRENT
GALE HEADLINES END PRIOR TO THE ISSUANCE OF A NEW HEADLINE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 9 PM MONDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1024 PM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 952 PM MST SUN NOV 24 2013
STRATUS ERODING FROM THE WEST DESPITE NO CHANGE TO WIND DIRECTION.
SO EARLIER REASONING PER WHAT WAS THOUGHT CONSISTENT GUIDANCE WITH
REALITY IS NOT PANNING OUT. LOVE THIS GUIDANCE.
UPDATE ISSUED AT 734 PM MST SUN NOV 24 2013
JUST COMPLETED AN UPDATE. MODEL OUTPUT STILL PLAYING CATCHUP. FINALLY
LOOKS LIKE TONIGHT WILL HAVE STRATUS FOR MOST IF NOT ENTIRE NIGHT
ESPECIALLY EAST OF THE COLORADO BORDER. THE RUC AND GFS HAVE CAUGHT
THIS IDEA VERY WELL. COMBINED THAT WITH THE HIGHER DEWPOINTS COMING
IN WILL MAKE FOR MUCH WARMER MINS THAN CURRENTLY DEPICTED. NWP IS
WOEFULLY TOO COOL. NEW MINS BASED ON THE RUC AND ARE WARMER. ALSO
BASED ON THE RUC...INCREASED THE SKY COVER.
PER AREA 00Z SOUNDINGS AND THE RUC/NAM/GFS FORECAST SOUNDINGS DECIDED
TO ADD PATCHY FREEZING FOG AND DRIZZLE. MADE IT FOR THE ENTIRE NIGHT
BUT LOOKS LIKE THE BEST CHANCE FOR THIS LOOKS TO BE AFTER 06Z WHEN
THE WARM LAYER ALOFT BECOMES MORE ESTABLISHED. CONTINUED THE FZDZ
AND FZFG THROUGH MID MORNING IN THE EAST. ADJUSTED WIND FIELD BASED
ON LATEST RUC AND ADJUSTED DEWPOINTS UP PER LATEST GFS.
UPDATE ISSUED AT 441 PM MST SUN NOV 24 2013
UPDATED FORECAST DUE TO EXPIRED WIND ADVISORY. ALSO PER DIMINISHED
RADAR RETURNS REMOVED POPS FROM THE EASTERN PORTION OF THE FORECAST
AREA. ALSO ADJUSTED SKY COVER PER RECENT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 104 PM MST SUN NOV 24 2013
WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED LARGE CLOSED H5 TROUGH
NEARING THE FOUR CORNERS AREA. AT THE SFC...STRONG PRESSURE
GRADIENT WAS IN PLACE ACROSS THE CWA WITH LOW DEEPENING OVER
COLORADO AND STRONG SFC RIDGE OVER EASTERN KS AND MO. NARROW AREA
OF STRONG WIND GUSTS IN EXCESS OF 40KTS...BETWEEN ITR AND GLD WAS
SLOWLY DIMINISHING.
WINDS SHOULD CONTINUE TO DECREASE AND FALL BELOW ADVISORY LEVELS
BEFORE SUNSET AS SFC COOLING ALLOWS BOUNDARY LAYER TO DECOUPLE. A
FEW LINGERING SNOW SHOWERS...WHICH LOOK LIKE THEY ARE BEING DRIVEN
BY ELEVATED CI WILL MOVE OUT OF THE AREA BY EARLY EVENING AS
POCKET OF DRY AIR SETTLES OVER THE AREA. UPPER LOW WILL NEAR THE
AREA TONIGHT AND WITH WEAK LIFT AND LOW STABILITY COULD SEE A
SHOWER OR TWO REDEVELOP AS IT PASSES. PROBABILITIES FROM ENSEMBLES
ARE VERY LOW AND GIVEN MUCH DRIER AIR MOVING INTO THE
AREA...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ATTM. WINDS WILL
DECREASE AND BECOME LIGHT TONIGHT PRIOR TO FRONTAL PASSAGE THAT
WILL BRING A PERIOD OF GUSTY NORTHERLY WINDS. WINDS ARE NOT
EXPECTED TO BE AS STRONG AS TODAY THOUGH. WITH A PERIOD OF LIGHT
WINDS AND SOME POTENTIAL THINNING OF THE HIGH CLOUDS HAVE LOWERED
MIN TEMPS SEVERAL DEGREES...ESPECIALLY ACROSS SOUTHERN CWA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 140 PM MST SUN NOV 24 2013
THE LARGE UPPER LOW OVER THE SOUTHWESTERN STATES WILL FINALLY
MOVE AWAY FROM THE FORECAST AREA BY THE START OF THE EXTENDED
PERIOD. NUMERICAL GUIDANCE INDICATES A FAST NORTHWEST FLOW ALOFT
WILL SET UP OVER THE N-C PLAINS STATES IN THE TUE-WED TIME FRAME...
GRADUALLY TRANSITIONING TO A BROAD RIDGE THU-FRI...AND FINALLY TO
A WSW FLOW SAT-SUN.
SEVERAL FAST-MOVING SHORT WAVE TROUGHS WILL MOVE THROUGH THE
NORTHWEST FLOW EARLY IN THE PERIOD...IMPACTING MAINLY THE NORTHERN
PLAINS AND GREAT LAKES. THE FORECAST AREA WILL EXPERIENCE SEVERAL
COLD FRONTAL PASSAGES ASSOCIATED WITH THESE UPPER TROUGHS...BUT
NO PRECIPITATION AND LITTLE IN THE WAY OF CLOUDS IS ANTICIPATED.
THE FIRST COLD FRONT WILL MOVE THROUGH THE AREA MONDAY WHICH WILL
BRING DOWN A FAIRLY COLD CANADIAN AIR MASS TUESDAY WHICH MOVES OUT
WEDNESDAY. AFTERNOON TEMPERATURES WILL BE 8-12 DEGREES BELOW
NORMAL AS A RESULT TUE-WED WITH HIGHS 35-45F. PREFERRED AN SREF
SOLUTION FOR TEMPS DURING THIS PERIOD. A SECOND WEAKER COLD FRONT
WILL BRUSH THE AREA EARLY THURSDAY WITH MINIMAL IMPACT.
AS THE UPPER FLOW TRANSITIONS TO A BROAD RIDGE LATER IN THE
WEEK...HIGH TEMPERATURES WILL RETURN TO NORMAL WITH MID 40S-
LOWER 50S FORECAST FOR THU-SUN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1021 PM MST SUN NOV 24 2013
STRATUS IS ERODING FROM THE WEST AND HAS MOVED EAST OF BOTH TAF
SITES. SO EXPECT TREND TO CONTINUE AND VFR CONDITIONS THROUGH THE
PERIOD. FRONT WILL MOVE THROUGH TOMORROW DURING THE MIDDLE OF THE
DAY AND EXPECT WINDS TO BECOME GUSTY UNTIL LATE IN THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...JRM
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
955 PM MST SUN NOV 24 2013
.UPDATE...
ISSUED AT 952 PM MST SUN NOV 24 2013
STRATUS ERODING FROM THE WEST DESPITE NO CHANGE TO WIND DIRECTION.
SO EARLIER REASONING PER WHAT WAS THOUGHT CONSISTENT GUIDANCE WITH
REALITY IS NOT PANNING OUT. LOVE THIS GUIDANCE.
UPDATE ISSUED AT 734 PM MST SUN NOV 24 2013
JUST COMPLETED AN UPDATE. MODEL OUTPUT STILL PLAYING CATCHUP. FINALLY
LOOKS LIKE TONIGHT WILL HAVE STRATUS FOR MOST IF NOT ENTIRE NIGHT
ESPECIALLY EAST OF THE COLORADO BORDER. THE RUC AND GFS HAVE CAUGHT
THIS IDEA VERY WELL. COMBINED THAT WITH THE HIGHER DEWPOINTS COMING
IN WILL MAKE FOR MUCH WARMER MINS THAN CURRENTLY DEPICTED. NWP IS
WOEFULLY TOO COOL. NEW MINS BASED ON THE RUC AND ARE WARMER. ALSO
BASED ON THE RUC...INCREASED THE SKY COVER.
PER AREA 00Z SOUNDINGS AND THE RUC/NAM/GFS FORECAST SOUNDINGS DECIDED
TO ADD PATCHY FREEZING FOG AND DRIZZLE. MADE IT FOR THE ENTIRE NIGHT
BUT LOOKS LIKE THE BEST CHANCE FOR THIS LOOKS TO BE AFTER 06Z WHEN
THE WARM LAYER ALOFT BECOMES MORE ESTABLISHED. CONTINUED THE FZDZ
AND FZFG THROUGH MID MORNING IN THE EAST. ADJUSTED WIND FIELD BASED
ON LATEST RUC AND ADJUSTED DEWPOINTS UP PER LATEST GFS.
UPDATE ISSUED AT 441 PM MST SUN NOV 24 2013
UPDATED FORECAST DUE TO EXPIRED WIND ADVISORY. ALSO PER DIMINISHED
RADAR RETURNS REMOVED POPS FROM THE EASTERN PORTION OF THE FORECAST
AREA. ALSO ADJUSTED SKY COVER PER RECENT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 104 PM MST SUN NOV 24 2013
WATER VAPOR IMAGERY/RUC ANALYSIS INDICATED LARGE CLOSED H5 TROUGH
NEARING THE FOUR CORNERS AREA. AT THE SFC...STRONG PRESSURE
GRADIENT WAS IN PLACE ACROSS THE CWA WITH LOW DEEPENING OVER
COLORADO AND STRONG SFC RIDGE OVER EASTERN KS AND MO. NARROW AREA
OF STRONG WIND GUSTS IN EXCESS OF 40KTS...BETWEEN ITR AND GLD WAS
SLOWLY DIMINISHING.
WINDS SHOULD CONTINUE TO DECREASE AND FALL BELOW ADVISORY LEVELS
BEFORE SUNSET AS SFC COOLING ALLOWS BOUNDARY LAYER TO DECOUPLE. A
FEW LINGERING SNOW SHOWERS...WHICH LOOK LIKE THEY ARE BEING DRIVEN
BY ELEVATED CI WILL MOVE OUT OF THE AREA BY EARLY EVENING AS
POCKET OF DRY AIR SETTLES OVER THE AREA. UPPER LOW WILL NEAR THE
AREA TONIGHT AND WITH WEAK LIFT AND LOW STABILITY COULD SEE A
SHOWER OR TWO REDEVELOP AS IT PASSES. PROBABILITIES FROM ENSEMBLES
ARE VERY LOW AND GIVEN MUCH DRIER AIR MOVING INTO THE
AREA...CONFIDENCE NOT HIGH ENOUGH TO INCLUDE ATTM. WINDS WILL
DECREASE AND BECOME LIGHT TONIGHT PRIOR TO FRONTAL PASSAGE THAT
WILL BRING A PERIOD OF GUSTY NORTHERLY WINDS. WINDS ARE NOT
EXPECTED TO BE AS STRONG AS TODAY THOUGH. WITH A PERIOD OF LIGHT
WINDS AND SOME POTENTIAL THINNING OF THE HIGH CLOUDS HAVE LOWERED
MIN TEMPS SEVERAL DEGREES...ESPECIALLY ACROSS SOUTHERN CWA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 140 PM MST SUN NOV 24 2013
THE LARGE UPPER LOW OVER THE SOUTHWESTERN STATES WILL FINALLY
MOVE AWAY FROM THE FORECAST AREA BY THE START OF THE EXTENDED
PERIOD. NUMERICAL GUIDANCE INDICATES A FAST NORTHWEST FLOW ALOFT
WILL SET UP OVER THE N-C PLAINS STATES IN THE TUE-WED TIME FRAME...
GRADUALLY TRANSITIONING TO A BROAD RIDGE THU-FRI...AND FINALLY TO
A WSW FLOW SAT-SUN.
SEVERAL FAST-MOVING SHORT WAVE TROUGHS WILL MOVE THROUGH THE
NORTHWEST FLOW EARLY IN THE PERIOD...IMPACTING MAINLY THE NORTHERN
PLAINS AND GREAT LAKES. THE FORECAST AREA WILL EXPERIENCE SEVERAL
COLD FRONTAL PASSAGES ASSOCIATED WITH THESE UPPER TROUGHS...BUT
NO PRECIPITATION AND LITTLE IN THE WAY OF CLOUDS IS ANTICIPATED.
THE FIRST COLD FRONT WILL MOVE THROUGH THE AREA MONDAY WHICH WILL
BRING DOWN A FAIRLY COLD CANADIAN AIR MASS TUESDAY WHICH MOVES OUT
WEDNESDAY. AFTERNOON TEMPERATURES WILL BE 8-12 DEGREES BELOW
NORMAL AS A RESULT TUE-WED WITH HIGHS 35-45F. PREFERRED AN SREF
SOLUTION FOR TEMPS DURING THIS PERIOD. A SECOND WEAKER COLD FRONT
WILL BRUSH THE AREA EARLY THURSDAY WITH MINIMAL IMPACT.
AS THE UPPER FLOW TRANSITIONS TO A BROAD RIDGE LATER IN THE
WEEK...HIGH TEMPERATURES WILL RETURN TO NORMAL WITH MID 40S-
LOWER 50S FORECAST FOR THU-SUN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 441 PM MST SUN NOV 24 2013
MODEL PROBLEMS RESOLVING THE SNOW FIELD/BOUNDARY LAYER MOISTURE
MAKE THIS A LITTLE TRICKY TAF FORECAST. CURRENTLY AT KGLD WE ARE
HAVING MVFR CEILINGS AND LOOKING UPSTREAM THESE COULD CONTINUE FOR
A WHILE. CURRENT CONDITIONS ARE BETWEEN THE MORE PESSIMISTIC NAM
AND THE MAV WHICH IS SHOWING NOTHING. RUC IS RATHER AGGRESSIVE IN
RETURNING BOUNDARY LAYER MOISTURE THIS EVENING. NAM AND RUC HAVE
BEEN THE MOST AGGRESSIVE AND WRONG MODELS THE LAST FEW DAYS WITH
THE GFS BETTER BUT ALSO OVERDOING IT SOME.
SO FOR KGLD WILL GO WITH A PERSISTENCE FORECAST THROUGH THE
EVENING WITH THE MVFR CONDITIONS AND WATCH THE TRENDS. WILL KEEP
VFR AT KMCK FOR NOW THROUGH THE PERIOD. IF MORE MOIST MODELS ARE
RIGHT WILL NEED MORE STRATUS AND MAYBE SOME FOG. SOUTH WINDS WILL
LOSE THEIR GUSTINESS IN THE NEXT HOUR OR TWO. THEN WILL BE LIGHT
AND VARIABLE UNTIL A PREFRONTAL TROUGH/COLD FRONT MOVE THROUGH
LATER TONIGHT INTO TOMORROW WHICH WILL MAKE FOR STRONG AND GUSTY
WINDS DURING THE DAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...JRM
LONG TERM...DLF
AVIATION...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1035 PM EST TUE NOV 26 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 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 700 PM EST TUE NOV 26 2013
EXPECT WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES THROUGH MOST OF
THE PERIOD...AS A STRONG STORM SYSTEM SPREADS RAIN AND THEN SNOW
ACROSS THE AREA. RAIN WILL CHANGE OVER TO SNOW FROM NORTHWEST TO
SOUTHEAST THIS EVENING...WITH SNOW CONTINUING INTO WEDNESDAY.
CONDITIONS WILL IMPROVE AFTER 12Z FOR MOST SITES AS THE SYSTEM MOVES
OUT TO THE EAST. HOWEVER...EASTERN LOCATIONS LIKE JKL AND SJS WILL
CONTINUE TO SEE LOWER VIS AND CIGS THROUGH THE DAY WEDNESDAY AS THE
SNOW BECOMES MORE UPSLOPE DRIVEN. WINDS WILL BE BRISK OUT OF THE
NORTHWEST AT 10 TO 20 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST WEDNESDAY FOR KYZ044-
050>052-058>060-069-080-085-086-104-106>109-111-112-114-116.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR KYZ068-079-
083-084.
WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR KYZ087-088-110-
113-115-117>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
700 PM EST TUE NOV 26 2013
.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 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 700 PM EST TUE NOV 26 2013
EXPECT WIDESPREAD IFR/LIFR CEILINGS AND VISIBILITIES THROUGH MOST OF
THE PERIOD...AS A STRONG STORM SYSTEM SPREADS RAIN AND THEN SNOW
ACROSS THE AREA. RAIN WILL CHANGE OVER TO SNOW FROM NORTHWEST TO
SOUTHEAST THIS EVENING...WITH SNOW CONTINUING INTO WEDNESDAY.
CONDITIONS WILL IMPROVE AFTER 12Z FOR MOST SITES AS THE SYSTEM MOVES
OUT TO THE EAST. HOWEVER...EASTERN LOCATIONS LIKE JKL AND SJS WILL
CONTINUE TO SEE LOWER VIS AND CIGS THROUGH THE DAY WEDNESDAY AS THE
SNOW BECOMES MORE UPSLOPE DRIVEN. WINDS WILL BE BRISK OUT OF THE
NORTHWEST AT 10 TO 20 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM EST WEDNESDAY FOR KYZ044-
050>052-058>060-069-080-085-086-104-106>109-111-112-114-116.
WINTER WEATHER ADVISORY UNTIL 1 PM EST WEDNESDAY FOR KYZ068-079-
083-084.
WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR KYZ087-088-110-
113-115-117>120.
&&
$$
UPDATE...GREIF
SHORT TERM...JJ
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1034 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 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 642 PM EST TUE NOV 26 2013
PASSAGE OF A DISTURBANCE AND ASSOCIATED SFC TROF WILL BRING LAKE
EFFECT SNOW SHOWERS TO KIWD/KCMX/KSAW THRU MUCH IF NOT ALL OF THIS
FCST PERIOD. AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL LIKELY
VARY CONSIDERABLY (FROM VFR TO AS LOW AS LIFR) AT ALL TERMINALS
TONIGHT/WED MORNING. AT KIWD...ENHANCED LOW-LEVEL CONVERGENCE SHOULD
GENERALLY RESULT IN IFR CONDITIONS FALLING TO LIFR THIS EVENING.
ARRIVAL OF DRIER AIR AND MORE ANTICYCLONIC FLOW LATE WED
MORNING/AFTN WILL RESULT IN IMPROVING CONDITIONS TO IFR THEN MVFR.
AT KCMX... DEVELOPING NRLY FLOW BEHIND TROF WILL NOT BE AS FAVORABLE
FOR PERSISTENT LOW CONDITIONS. MUCH OF THE NIGHT SHOULD SEE
CONDITIONS VARYING BTWN IFR AND MVFR WITH MVFR PROBABLY PREVAILING
WED. AT KSAW...INITIAL VFR CONDITIONS WILL DROP RAPIDLY TO IFR AS
WINDS SHIFT NORTHERLY AND HEAVIER SNOW SHOWERS ARRIVE 04-06Z.
IMPROVEMENT TO IFR THEN MVFR WILL OCCUR WED AFTN.
&&
.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 MARQUETTE MI
643 PM EST TUE NOV 26 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 505 PM EST TUE NOV 26 2013
WV IMAGERY AND RUC ANALYSIS REVEALS A WELL-DEFINED MID/UPPER LEVEL
SHORTWAVE ROTATING EAST ACROSS THE UPPER GREAT LAKES THIS AFTERNOON.
AT THE SFC...LOW PRES WAS LOCATED OVER NRN LAKE HURON WITH A COLD
FRONT EXTENDING SE THROUGH LOWER MI AND A TROUGH STRETCHING TO THE
NORTHWEST OVER NRN ONTARIO. 700-300 QVECTOR CONV OUT AHEAD
OF THE SHRTWV SUPPORTED AN AREA OF SHSN ACROSS WEST AND CNTRL UPPER
MI EARLIER TODAY WITH SOME HEAVIER LES REPORTED ALONG AND BEHIND
INITIAL FRONTAL PASSAGE. SOME AREAS NEAR WAKEFIELD/BESSEMER REPORTED
8-9 INCHES OF LAKE ENHANCED SNOW ALREADY FROM THE SNOW THAT STARTED
EARLY THIS MORNING WHILE MODERATE TO HEAVY LES WAS ALSO REPORTED
OVER PORTIONS OF HOUGHTON...NW MQT AND WRN ALGER COUNTIES.
EXPECT LES TO CONTINUE MODERATE TO HEAVY AT TIMES TONIGHT INTO
WEDNESDAY AS THE TROUGH JUST NORTH OF LAKE SUPERIOR MOVES SOUTH
ACROSS THE AREA LATE THIS EVENING AND SHIFTS WINDS FROM NW TO MORE
NNE DIRECTION OVER LAKE SUPERIOR. THIS WILL PUSH HEAVIER LES BANDS
INTO MARQUETTE COUNTY AND WRN ALGER COUNTY WITH ANOTHER DOMINANT
BAND LIKELY SETTING UP OVER THE PORCUPINE MTNS/IRONWOOD AREA. MOST
OF THE MODELS SUGGEST THAT THIS WILL OCCUR JUST AFT 00Z WHEN THE MID
LEVEL TROUGH AXIS MOVES INTO ERN UPPER MI. EXPECT THE GREATEST
SNOWFALL RATES NEAR MARQUETTE LATE THIS EVENING SHIFTING INTO THE
HIGHER TERRAIN WEST OF MARQUETTE OVERNIGHT INTO WEDNESDAY AS THE
UPSLOPE COMPONENT STRENGTHENS. OVER THE WEST...THE STRONGEST LOW
LEVEL CONV IS EXPECTED INTO IRONWOOD/WAKEFIELD/BERGLAND/PORCUPINE
MTNS WITH SNOWBANDS ORIGINATING NEAR THUNDER BAY AND PERHAPS
CONNECTING WITH LAKE NIPIGON IN STRONG MOIST CYCLONIC NNE FLOW. WITH
BUFR SNDGS INDICATING THE STRONGER UPWARD MOTION IN THE DGZ FOR MUCH
OF THE EVENT...EXPECT SLR VALUES IN THE 25/1 RANGE ARE EXPECTED.
THERE MAY ALSO BE SOME GUSTY WINDS ALONG THE LAKESHORE TONIGHT WHERE
WINDS MAY GUST TO AROUND 30 MPH. THE SNOW AND BLOWING SNOW WILL MAKE
ROADS HAZARDOUS AND TRAVEL DIFFICULT TONIGHT INTO WEDNESDAY.
THE GREATEST SNOWFALL AMOUNTS TONIGHT SHOULD ALSO BE IN THE 3 TO 7
INCH RANGE OVER THE HIGHER TERRAIN OF WRN MQT COUNTY AND FROM WHITE
PINE TO BERGLAND WEST TO IRONWOOD. WEDNESDAY....EXPECT ANOTHER 2-4
OF SNOW OVER GOGEBIC-ONTONAGON COUNTIES WITH ANOTHER 3-6 INCHES OVER
THE HIGHER TERRAIN OF WRN MQT COUNTY. GIVEN EXPECTED AMOUNTS AND
BLOWING SNOW POTENTIAL HAVE DECIDED TO UPGRADE GOGEBIC-ONTONAGON TO
AN LES WARNING THROUGH 18Z WED WHILE I ALSO UPGRADED MQT TO LES
WARNING FOR TONIGHT THROUGH WEDNESDAY.
FOR NOW LEFT LES ADVISORIES GOING FOR KEWEENAW-NRN HOUGHTON INTO
TONIGHT AND FOR BARAGA COUNTIES AND ALGER COUNITES INTO WED
AFTERNOON. WRN ALGER WILL NEED TO BE CLOSELY MONITORED TONIGHT AS
HEAVIER LES BANDS COULD PUSH AMOUNTS NEAR WARNING CRITERIA.
INFLUZ OF DRIER AIR AND WEAKENING NNE FLOW SHOULD ALLOW LES TO TAPER
OFF WED AFTERNOON FROM WEST TO EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 416 PM EST TUE NOV 26 2013
UPPER MICHIGAN WILL REMAIN UNDER THE INFLUENCE OF THE MAIN LOW NEAR
HUDSON BAY THROUGH EARLY FRIDAY...WITH DISTURBANCES CONTINUING TO
SWING ACROSS THE REGION. THE THERMOMETERS OUTSIDE WILL BE BELOW
TURKEY THAWING CONDITIONS...BOTTOMING OUT IN THE TEENS FOR MOST
LOCATIONS.
THOSE WHO ENJOY SNOW WILL BE THANKFUL FOR MORE SNOW SHOWERS
THURSDAY. THE SFC LOW ACROSS SD AT 00Z THURSDAY WILL WEAKEN OVER MN
AND IA WEDNESDAY NIGHT...BEFORE SLOWLY CROSSING UPPER MI AND LAKE MI
THURSDAY INTO FRIDAY. CURRENT THINKING IS FOR THE BEST BANDS OF SNOW
TO BE OFF-SHORE OVER W LAKE SUPERIOR...STRETCHING THROUGH KEWEENAW
COUNTY AND TROUGH S CENTRAL LAKE SUPERIOR. COULD HAVE 2-5IN OF LAKE
EFFECT SNOW FOR KEWEENAW COUNTY. THE NAM AND OTHER SMALLER SCALE
MODELS ARE A LITTLE MORE BULLISH ON THE SNOW/QPF ACCUMULATION OVER
THE TIP OF THE KEWEENAW PENINSULA. MAY NEED AN ADVISORY IF CURRENT
THINKING REMAINS.
OTHERWISE...FRIDAY WILL BE MARKED BY WAA. LEFTOVER POCKETS OF COLD
AIR FRIDAY WILL KEEP TEMPERATURES MAXING OUT IN THE MID TO UPPER
20S. 850MB TEMPS SHOULD RISE INTO THE -7 TO -13C RANGE BY 00Z
SATURDAY. THE 500MB RIDGE BUILDING IN FRIDAY AFTERNOON AND EVENING
WILL BE SHORT LIVED. THE NEXT TROUGH SET UP FROM MANITOBA THROUGH
THE N PLAINS AT 06Z SATURDAY SHOULD SLOWLY EDGE ACROSS MANITOBA AND
THE UPPER GREAT LAKES SATURDAY THROUGH EARLY SUNDAY. WHILE POPS WILL
INCREASE BACK TO CHANCES AGAIN SATURDAY INTO SATURDAY NIGHT THERE
LOOKS TO BE LITTLE MOISTURE TO WORK WITH...GIVEN THE ORIGIN OF THE
DISTURBANCE.
EXPECT BREEZY CONDITIONS E ON SATURDAY...WITH WINDS JUST ABOVE THE
SFC OUT OF THE SSW AROUND 40-45KTS. SFC TEMPS SHOULD RETURN TO THE
30S CWA WIDE FOR THE 1ST TIME SINCE MONDAY. THE NEXT CLIPPER-LIKE
SYSTEM SHOULD BE SWINGING IN FROM THE NW SATURDAY AFTERNOON. TIMING
IS STILL A CONCERN...WITH THE 12Z RUNS OF THE ECMWF AND GFS
DIFFERING BY 350MI AT 18Z SATURDAY. THE ECMWF HAS IT ACROSS S
CENTRAL ONTARIO...WHILE THE LOW OFF THE GFS IS NEAR THE
MANITOBA/ONTARIO BORDER. OF MORE OF A CONCERN IS THEIR HANDLING OF
THE NEXT...MORE SIGNIFICANT LOOKING SYSTEM...IN THE FORM OF A 500MB
LOW SINKING ACROSS THE PACIFIC NW MONDAY. STILL...THE IMPACTS OF
THAT ONE WILL NOT REALLY BE NOTICED UNTIL CLOSER TO MID WEEK...WITH
THE ASSOCIATED SFC LOW PUSHING ACROSS THE PLAINS STATES TUESDAY AS
THE 500MB LOW SLIDES ACROSS MT. WILL HAVE TO WAIT TO SEE WHAT SORT
OF IMPACTS THIS ONE WILL HAVE ACROSS THE UPPER GREAT LAKES OVER THE
NEXT FEW DAYS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 642 PM EST TUE NOV 26 2013
PASSAGE OF A DISTURBANCE AND ASSOCIATED SFC TROF WILL BRING LAKE
EFFECT SNOW SHOWERS TO KIWD/KCMX/KSAW THRU MUCH IF NOT ALL OF THIS
FCST PERIOD. AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL LIKELY
VARY CONSIDERABLY (FROM VFR TO AS LOW AS LIFR) AT ALL TERMINALS
TONIGHT/WED MORNING. AT KIWD...ENHANCED LOW-LEVEL CONVERGENCE SHOULD
GENERALLY RESULT IN IFR CONDITIONS FALLING TO LIFR THIS EVENING.
ARRIVAL OF DRIER AIR AND MORE ANTICYCLONIC FLOW LATE WED
MORNING/AFTN WILL RESULT IN IMPROVING CONDITIONS TO IFR THEN MVFR.
AT KCMX... DEVELOPING NRLY FLOW BEHIND TROF WILL NOT BE AS FAVORABLE
FOR PERSISTENT LOW CONDITIONS. MUCH OF THE NIGHT SHOULD SEE
CONDITIONS VARYING BTWN IFR AND MVFR WITH MVFR PROBABLY PREVAILING
WED. AT KSAW...INITIAL VFR CONDITIONS WILL DROP RAPIDLY TO IFR AS
WINDS SHIFT NORTHERLY AND HEAVIER SNOW SHOWERS ARRIVE 04-06Z.
IMPROVEMENT TO IFR THEN MVFR WILL OCCUR WED AFTN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST TUE NOV 26 2013
WEAK LOW PRESSURE OVER S ONTARIO WILL MOVE E OVERNIGHT AS HIGH
PRESSURE OVER THE N PLAINS TONIGHT SLIDES INTO THE GREAT LAKES
REGION...WEAKENING SLIGHTLY BY WEDNESDAY AFTERNOON. IN BETWEEN THESE
2 SYSTEMS...N GALES TO 35KTS ARE EXPECTED OVER MAINLY CENTRAL AND E
LAKE SUPERIOR TONIGHT...CONTINUING WITH MAINLY GALE FORCE GUSTS
WEDNESDAY OVER E PORTIONS OF LAKE SUPERIOR.
LOW PRESSURE OVER THE SE U.S. TONIGHT WILL MOVE NORTHEASTWARD INTO
THE NEW ENGLAND STATES BY WEDNESDAY EVENING WHILE DEEPENING...WHICH
WILL KEEP A TROUGH OVER THE LOWER LAKES. FOR THURSDAY INTO
FRIDAY...ANOTHER WEAK TROUGH SHOULD CROSS LAKE SUPERIOR...MERGING
WITH A HIGH OVER LAKE ONTARIO BY FRIDAY EVENING. AS THE HIGH MOVES E
TOWARDS THE ATLANTIC SATURDAY AFTERNOON INTO SUNDAY...ANOTHER WEAK
TROUGH WILL CROSS LAKE SUPERIOR. ANOTHER PERIOD OF STRONGER
WINDS...OUT OF THE S NEAR 30KTS...WILL BE POSSIBLE SATURDAY OVER
MAINLY E LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ WEDNESDAY FOR
MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR MIZ001-
003.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST WEDNESDAY FOR MIZ004-
006.
LAKE EFFECT SNOW WARNING UNTIL 7 PM EST WEDNESDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ084.
LAKE SUPERIOR...
GALE WARNING FROM MIDNIGHT TONIGHT TO 1 PM EST WEDNESDAY FOR
LSZ266-267.
GALE WARNING FROM MIDNIGHT TONIGHT TO 10 AM EST WEDNESDAY FOR
LSZ265.
GALE WARNING FROM MIDNIGHT TONIGHT TO 5 AM EST WEDNESDAY FOR
LSZ264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1257 PM EST MON NOV 25 2013
.SYNOPSIS...
ISSUED AT 449 AM EST MON NOV 25 2013
WINTRY CONDITIONS WILL BE PREVALENT ACROSS NORTHERN MICHIGAN THROUGH
THE THANKSGIVING HOLIDAY WEEK...WITH SEVERAL WEAKER WEATHER SYSTEMS
DELIVERING REPEATED SHOTS OF BOTH SYSTEM AND LAKE EFFECT SNOW. THE
FIRST WILL ARRIVE THIS MORNING...AS LOW PRESSURE TRACKS NEAR JAMES
BAY...BRINGING A ROUND OF SNOW TO MUCH OF NORTHWEST LOWER AND
EASTERN UPPER. A COLD FRONT WILL GRADUALLY WORK THROUGH THE REGION
LATER TUESDAY...BRINGING RENEWED COLD CONDITIONS ALONG WITH MORE
LAKE EFFECT SNOW. THAT GENERAL TREND WILL CONTINUE INTO THANKSGIVING
DAY...BEFORE QUIET WEATHER MAKES A RETURN TOWARD NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 1239 PM EST MON NOV 25 2013
AS EARLIER ANTICIPATED...DEEPER MOISTURE IS IN THE PROCESS OF
EXITING THE AREA...AND THIS HAS CAUSED SNOW SHOWER ACTIVITY TO
DIMINISH QUITE RAPIDLY PAST 1-2 HRS. IN GENERAL...1-3 INCHES OF
SNOW HAS FALLEN THUS FAR ACROSS NW LOWER AND PARTS OF ERN UPPER.
GIVEN MODEST OVER-WATER INSTABILITY...DON/T EXPECT MUCH MORE THAN
SCATTERED SNOW SHOWERS /WITH LITTLE NEW ACCUMULATION/ UNTIL
MOISTURE DEEPENS BACK UP A BIT EARLY THIS EVENING. WILL UPDATE
FORECAST TO REFLECT THIS TREND.
SOME CONCERN THAT SHALLOWING MOISTURE PROFILE (TO WARMER THAN
ABOUT -8C) MAY SUPPORT SOME DRIZZLE OR FREEZING DRIZZLE THIS
AFTERNOON (DEPENDING ON LOCATION AND SURFACE TEMPERATURE). SOME
OBS ALONG THE LAKE MICHIGAN SHORELINE ARE SHOWING MVFR VSBYS
WITHOUT SNOW BEING REPORTED. 88D ALSO SHOWING A BROADENING AREA OF
WEAK RADAR RETURNS - POSSIBLY INDICATIVE OF DRIZZLE. WILL MONITOR
FOR THIS POTENTIAL WEATHER/HAZARD.
UPDATE ISSUED AT 930 AM EST MON NOV 25 2013
QUICK SHOT OF LAKE ENHANCED SNOW CONTINUES TO IMPACT EAST UPPER
AND NW LOWER THIS MORNING...AS SHORT WAVE AND ASSOCIATED DEEP MOISTURE
SWINGS THROUGH THE REGION. OVERALL LAKE CONTRIBUTION NOT
GREAT...WITH WATER TEMPS NEAR +8C AND 850 MB TEMPS AROUND -6C
(IDEA FURTHER SUPPORTED BY 12Z APX/GRB SOUNDINGS).
THAT SAID...COMBINATION OF ONGOING SNOW BURST AND CONTINUED GUSTY
WINDS WILL STILL RESULT IN NEAR-ADVISORY CONDITIONS NEXT SEVERAL
HOURS WITH LOCALLY DIFFICULT TRAVEL. HOWEVER...AS DEEPER MOISTURE
DEPARTS AND ONLY MARGINAL LAKE CONTRIBUTIONS LINGER...SUSPECT A
MARKED DECREASE IN SNOW SHOWER INTENSITY EARLY THIS AFTERNOON. FOR
THIS REASON...EXPECT 2-4 INCH SNOW AMOUNTS /MAINLY NW LOWER/ TO
HOLD FOR THE DAY.
UPDATE ISSUED AT 629 AM EST MON NOV 25 2013
DEEP MOISTURE OUT AHEAD OF AN ADVANCING COLD FRONT IS STARTING TO
DEVELOP SNOWS ACROSS FAR NRN LAKE MICHIGAN AND THROUGH THE STRAITS
REGION. STILL DEFINITELY EXPECTING A RAPID PRODUCTION AND
INTENSIFICATION OF SNOWS IN A SW TO NE ORIENTED BAND...COMBINED
WITH VERY STRONG SW WIND GUSTS TO 50 MPH. THIS WILL BRING A PERIOD
OF MODERATE TO HEAVY SNOWS ACROSS MUCH OF NW LOWER AND EASTERN
SECTIONS OF CHIP/MACK COUNTIES THIS MORNING. ALREADY ISSUED THE
INITIAL SPS ALERTING OF RAPIDLY DEVELOPING HAZARDOUS DRIVING
CONDITIONS. FOLKS...PLEASE ALLOW EXTRA TIME TO REACH YOUR
DESTINATION. DID INCREASE SNOWFALL ACROSS AN AREAS SURROUNDING
LEELANAU COUNTY...WHERE A LONGER PERIOD OF SNOWS ARE EXPECTED THIS
MORNING. OTHERWISE...THE FORECAST IS IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 449 AM EST MON NOV 25 2013
WELL...THAT WAS A NICE 12-ISH HOUR RESPITE FROM THE ACTIVE WEATHER.
NOW IT`S GAME ON ONCE AGAIN...WITH THE MAIN FORECAST ISSUES BEING OF
THE LAKE EFFECT/ENHANCEMENT VARIETY...ALONG WITH WIND ISSUES THROUGH
THE DAY TODAY. EARLY MORNING ANALYSIS PLACES VERY WEAK SHORTWAVE
RIDGE AXIS JUST TO THE EAST OF NORTHERN MICHIGAN...WITH DEEP AND
QUITE STRONG SOUTHWESTERLY FLOW WELL RAMPED UP ACROSS THE NORTHERN
LAKES IN ADVANCE OF ANOTHER STRONG UPPER WAVE QUICKLY AMPLIFYING
THROUGH SOUTHERN MANITOBA. INITIAL PUSH OF THAT WARM ADVECTION
EARLIER LED TO A BRIEF AXIS OF LIGHT SNOW MARCHING THROUGH
NORTHERN/EASTERN AREAS...WITH SECONDARY SURGE OF MUCH DEEPER AND
STRONGER ASCENT GOING INTO GRADUAL TOP-DOWN SATURATION OFF TO OUR
WEST AT THE MOMENT...AS EVIDENCED BY CEILINGS FALLING 5-8KFT OVER
THE PAST FEW HOURS. MEANWHILE...QUITE THE WINDY CONDITIONS HAVE
SHOWN UP RECENTLY AS CORE OF RATHER IMPRESSIVE 45-55 KNOT FLOW IS
ROLLING OVERHEAD...COMBINING WITH A REMNANT UNSTABLE AIRMASS ACROSS
THE LAKES TO PRODUCE SOME RATHER BEEFY WIND GUSTS PUSHING 50 MPH
ALONG THE LAKE MICHIGAN SHORE.
THE ABOVE MENTIONED WARM ADVECTION WILL BE IMPORTANT FOR OUR AREA
THIS MORNING...AS THE ADDED MOISTURE (FROM AN INITIALLY QUITE DRY
AIRMASS) GIVES A BIG BOOST OVER LAKE MICHIGAN. ALREADY SEEING THE
FIRST HINTS OF THIS RIGHT NOW...BUT THE THOUGHT IS THAT DEEPER
MOISTURE OVERRIDING THE LAKE WILL GO INTO THE RAPID PRODUCTION OF A
SOUTHWEST FLOW LAKE BAND THE NEXT FEW HOURS...WHICH WILL ULTIMATELY
GET PUNTED ONSHORE AS THE SHARP UPPER WAVE OVER MANITOBA WORKS
TOWARD OUR AREA. THESE TYPES OF SETUPS ALWAYS HAVE TROUBLE WRITTEN
ALL OVER THEM FROM AN IMPACT STANDPOINT...AS THERE SHOULD BE A
COUPLE HOUR WINDOW FOR SOME HEAVY SNOW TO FALL UP AND DOWN THE LAKE
MICHIGAN SHORELINE COUNTIES...AND PROBABLY EVEN FARTHER INLAND INTO
THE HIGHER TERRAIN WHERE UPSLOPE TYPICALLY WORKS ITS MAGIC IN SUCH A
SETUP. GIVEN WARMING THERMAL PROFILES...SNOW TO LIQUID RATIOS SHOULD
BE RATHER LOW...AS EVIDENCED BY A QUITE DEEP ISOTHERMAL LAYER AROUND
-6C PER FORECAST RAOBS...MAKING FOR MORE OF A GREASY/SLIPPERY SNOW.
THROW IN SOME QUITE GUSTY WINDS AND THE STAGE IS PROBABLY SET FOR A
PERIOD OF SLOPPY TRAVEL/LOW VSBYS ACROSS PRIMARILY NORTHWEST
LOWER...WITH A QUICK 2-3" OF SNOW EXPECTED TO FALL. LOCAL 4/12KM APX
WRF AND RECENT HRRR RUNS ARE EVEN MORE IMPRESSIVE...PAINTING AN AXIS
OF 0.4" OF LIQUID UP TOWARD CHARLEVOIX/EMMET/CHEBOYGAN/OTSEGO/ANTRIM
COUNTIES...WITH A SECONDARY MAXIMUM NEAR CADILLAC. GIVEN THE
EXPECTED LOWER RATIOS...SHOULDN`T SEE ACCUMULATION GET OUT OF
HAND...EVEN IF THE HIGHER QPF FORECASTS VERIFY. NOT SURE THIS WILL
BE WORTHY OF A WINTER WEATHER HEADLINE - PROBABLY MORE LIKE AN
SPS...ESPECIALLY CONSIDERING THE WORST CONDITIONS SHOULD OCCUR JUST
AFTER THE MORNING COMMUTE (MAINLY 9AM-1PM).
WINDS WILL SUBSIDE HEADING INTO THE AFTERNOON AS THE CORE OF
STRONGEST 950-900MB FLOW EXITS EAST...ALL WHILE DEEPER MOISTURE ALSO
STRIPS OUT. THAT LEAVES US IN MORE OF A LIGHT SNOW SHOWERS/SNIZZLE
REGIME FOR MUCH OF THE AFTERNOON AS SOUTHWEST FLOW CONTINUES BUT
WHILE CLOUD TOP TEMPS HOVER ONLY AROUND -8C. PROBABLY NOT LOOKING AT
MUCH ADDITIONAL ACCUMULATION FOR MOST AREAS THROUGH LATE AFTERNOON.
HOWEVER...MORE ISSUES SHOW UP BY EARLY EVENING WITH PERSISTENT HINTS
OF A STRONGER FRONTAL SNOW BAND BEING BROUGHT ASHORE INTO EASTERN
UPPER AS LOW PRESSURE NEARS THE SOUTHERN TIP OF JAMES BAY AND SWINGS
A COLD FRONT THROUGH THE EASTERN U.P. THAT FEATURE WILL IN ALL
LIKELIHOOD BECOME ABSORBED INTO THE LAKE AGGREGATE TROUGH OVER
EASTERN LAKE SUPERIOR...WITH PERHAPS EVEN A WEAK CIRCULATION CENTER
DEVELOPING IN RESPONSE TO YET ANOTHER STRONG UPPER WAVE ENTERING THE
ARROWHEAD OF MINNESOTA. THAT SETUP COULD LEAD TO ALL KINDS OF
MESOSCALE GARBAGE...BUT THE CLEAR SIGNAL IS FOR AN ENHANCED
CONVERGENCE BAND TO SKIRT FAR NORTHERN CHIPPEWA COUNTY...MAINLY
TOWARD PARADISE/WHITEFISH POINT...WITH MAYBE A COUPLE INCHES
POSSIBLE. FARTHER SOUTH...LOOKING LIKE PERSISTENT MORE NEBULOUS SNOW
SHOWERS WILL CONTINUE OVERNIGHT FOR SOUTHWEST FLOW AREAS ACROSS
NORTHWEST LOWER UP TOWARD DRUMMOND ISLAND. WAS A LITTLE CONCERNED
ABOUT SOME DRIZZLE POSSIBILITIES GIVEN INITIALLY SHALLOW NATURE OF
MOISTURE...BUT GRADUAL INTRUSION OF COLDER AIR ALOFT SHOULD FAVOR
ICE IN THE CLOUDS AS CLOUD TOP TEMPS END UP AROUND -12C BY 06Z. NO
MAJOR ACCUMULATION FORESEEN FOR NORTHERN LOWER OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 449 AM EST MON NOV 25 2013
A VERY ACTIVE AND RAPIDLY CHANGING WEATHER PATTERN WILL REMAIN
LOCKED IN ACROSS THE GREAT LAKES THROUGH THE THANKSGIVING HOLIDAY
WITH A SERIES OF SHORTWAVES AND SHOTS OF COLDER CANADIAN AIR
RESULTING IN A COUPLE OF ROUNDS OF LAKE EFFECT AND LAKE ENHANCED
SNOWFALL. THIS WILL ALSO PREVENT US FROM ANY SIGNIFICANT WARMING FOR
THE NEXT SEVERAL DAYS. A FAIRLY QUIET PERIOD OF WEATHER IS THEN
ANTICIPATED FOR FRIDAY THROUGH THE WEEKEND.
TUESDAY THROUGH WEDNESDAY NIGHT...A SIMILAR SET UP LIKE TODAY...IS
EXPECTED FOR TUESDAY WITH NEXT VIGOROUS SHORTWAVE...COLD FRONT AND
DEEPER MOISTURE ANTICIPATED TO MOVE IN ACROSS NRN MICHIGAN. THIS
TIME AROUND...WE WILL HAVE A BIT DEEPER INSTABILITY BUT LESS WIND.
WEST/WSW FLOW AHEAD OF THIS FRONT...H8 TEMPS COLDER IN THE -10C TO
-11C RANGE AND INVERSION HEIGHTS TO 7KFT WILL INCREASE TO NEAR 9KFT
WITH COLD ADVECTION THROUGH THE DAY...BUT A DRAMATIC SHIFT IN WINDS
TO OUT OF THE NNW INTO TUESDAY EVENING. THE MOST IMPRESSIVE LES
PARAMETERS ARE REALLY FOCUSED TUESDAY EVENING AFTER THE FLOW TURNS
NORTHERLY WITH DEEPEST INSTABILITY WITH PASSAGE OF UPPER TROUGH
AXIS/COLD AIR ALOFT. THIS WILL FOCUS THE BEST ACCUMULATION
POTENTIAL ACROSS THE GTV BAY REGION AND AREAS SOUTH...WHERE
ALSO...GUSTY WINDS COULD LEAD TO BLOWING AND DRIFTING ISSUES. A
CONSERVATIVE 3-6 INCHES OF SNOW WILL BE POSSIBLE IN THIS REGION
TUESDAY-TUESDAY NIGHT...LEADING TO THE MOST HAZARDOUS DRIVING
CONDITIONS EXPECTED IN THE LONG TERM PORTION OF THE FORECAST. THE
AIR MASS DRIES WITH LOWERING INVERSION HEIGHTS INTO
WEDNESDAY...HOWEVER CONTINUED COLD ADVECTION AND BEST FETCH INTO
GTV BAY WILL LEAD TO ANOTHER 1-2 INCHES OF SNOW THERE...WHILE
AMOUNTS ARE LESS IMPRESSIVE ELSEWHERE. FAR NE LOWER NEAR ROGERS
CITY/ALPENA AND OSCODA WILL SEE A SMATTERING OF 1 TO MAYBE 3 INCH
LOCAL AMOUNTS TUESDAY NIGHT INTO WEDNESDAY. WEDNESDAY
NIGHT...INVADING HIGHER PRESSURE AND LIGHTER WINDS FOR A LESSER
THREAT TO ANYTHING SIGNIFICANT IN THE SNOW DEPARTMENT.
HOWEVER...WILL HAVE TO KEEP AN EYE ON NEXT INCOMING SHORTWAVE AND
WARM ADVECTION OVER THE TOP OF THE REMAINING
INSTABILITY...ALTHOUGH MOST AREAS...LOOK TO HAVE A DISCONNECT FROM
THE MOISTURE AND ENHANCEMENT SEEDED FROM ALOFT. SLOWLY BACKING LOW
LEVEL WINDS WILL FOCUS ANY EMERGING THREAT OF RENEWED SNOW IN AND
AROUND LAKE MICHIGAN.
THANKSGIVING DAY AND NIGHT...THIS INCOMING WAVE IS RATHER WEAK
COMPARED TO IT`S PREDECESSORS....ALTHOUGH THE WARM ADVECTION/SEEDING
ALOFT DOES LOOK TO STILL HAVE SOME SORT OF ENHANCEMENT TO THE LAKE
EFFECT THROUGH THE HOLIDAY AND THURSDAY NIGHT. WINDS ARE EXPECTED TO
BE FAIRLY LIGHT...AND NOW SHIFTING ALL AROUND TO THE SW AS THIS
ENHANCEMENT PROCESS IN UNDERWAY...SPREADING SNOWS AROUND LAKE
MICHIGAN WITH LESS INLAND PENETRATION. THESE FINER DETAILS WILL
REALLY HAVE TO BE EXAMINED FURTHER OVER THE NEXT COUPLE OF DAYS TO
PROVIDE A MORE DETAILED HOLIDAY FORECAST. WIND DIRECTIONS AND SPEEDS
BEING THE MOST CRUCIAL...WHICH HAS A BIT OF UNCERTAINTY.
FRIDAY THROUGH SUNDAY...THIS WEAKER WAVE EXITS FRIDAY WITH SHALLOW
MID LEVEL RIDGING...AHEAD OF NEXT ADVERTISED SHORTWAVE ARRIVING
SATURDAY. A WEAK COLD FRONT LAYS ACROSS/WASHES OUT OVER NRN
MICHIGAN. COULD BE ONE LAST HOORAH OF SOME WEAKER LAKE EFFECT...BUT
THIS APPEARS TO BE THE LEAST OF CONCERN IN THE SERIES OF LAKE EFFECT
EVENTS. THIS MAINLY DUE TO THE CONTINUED LOW LEVEL WARM ADVECTION
AND GRADUAL EROSION OF THE OVERLAKE INSTABILITY. WILL HAVE RATHER
SMALL CHANCES FOR SNOW IN AND AROUND LAKE MICHIGAN IN THE SW FLOW
THAT PERSISTS INTO SUNDAY. TEMPERATURES WILL MODERATE BACK INTO THE
LOWER HALF OF THE 30S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM EST MON NOV 25 2013
LOW LEVEL MOISTURE WILL REMAIN WIDESPREAD THROUGH TUESDAY...WITH
PRIMARILY MVFR CEILINGS ACROSS NW LOWER MI (TVC/PLN/MBL)...AND VFR
CEILINGS NE LOWER MI (APN). THERE MAY BE A BRIEF PERIOD OF HIGHER
(VFR) CEILINGS TONIGHT...BUT NOT A HIGH CONFIDENCE OCCURRENCE.
OTHERWISE...SCATTERED SNOW SHOWERS WILL PERSIST DOWNWIND OF LAKE
MICHIGAN THROUGH TUESDAY. THE NEXT INCREASE IN LAKE SNOW IS
EXPECTED MIDDAY TUESDAY...AS COLDER AIR SWEEPS EWD ACROSS LAKE
MICHIGAN. WINDS WILL REMAIN BRISK FROM THE SOUTHWEST.
&&
.MARINE...
ISSUED AT 449 AM EST MON NOV 25 2013
A WINDY ONE OUT THERE TO START...WITH GALES FOR MOST OF THE WATERS.
THOSE WINDS WILL SUBSIDE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING...THOUGH WILL REMAIN A BIT GUSTY IN THE 20-25 KNOT RANGE AS
IS TYPICAL FOR LATE NOVEMBER. WINDS WILL GRADUALLY COME AROUND TO
THE NORTHWEST ON TUESDAY AND THEN NORTH TUESDAY NIGHT AND
WEDNESDAY...WITH CONTINUED GUSTS OF 25-30 KNOTS EXPECTED. COULD SEE
A PERIOD OF GALES ON MAINLY LAKE MICHIGAN SOMETIME TUESDAY NIGHT...
BUT CONFIDENCE IN THAT IS LOW AT THIS TIME. HIGH PRESSURE WILL
FINALLY WIN THE BATTLE BY THURSDAY...WITH A RETURN TO A BRIEF PERIOD
OF MUCH LIGHTER WINDS OF THE 15 KNOTS OF LESS VARIETY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ015-016-019-
020-025-031.
LH...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...BS
SYNOPSIS...DL
SHORT TERM...DL
LONG TERM...SD
AVIATION...BS
MARINE...DL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1200 PM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1200 PM EST MON NOV 25 2013
AS A STRONG DISTURBANCE OVER ONTARIO AND ITS ATTENDANT SFC COLD
FRONT DIGS SE INTO THE AREA...EXPECT MVFR CIGS AT IWD AND CMX
THROUGH THIS PERIOD WITH LAKE EFFECT SNOW SHOWERS CONTINUING. AS
WINDS GET MORE NORTHERLY WITH TIME...BOTH SITES WILL GO TO IFR VIS
IN THE HEAVIER SNOW SHOWERS STARTING FIRST AT CMX BY THIS EVENING
AND BY TUE MORNING AT IWD. AT SAW...MVFR CIGS WILL MOVE OUT THIS
AFTERNOON WITH A DOWNSLOPE WIND HELPING TO RAISE CIGS TO LOW VFR.
WITH A WEST WIND AT SAW THIS EVENING THROUGH TUE MORNING...MVFR
CONDITIONS WILL SET UP WITH SOME SNOW SHOWERS MOVING IN THIS
EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 533 AM EST MON NOV 25 2013
SW TO W GALES OVER LAKE SUPERIOR THIS MORNING ARE EXPECTED TO
DIMINISH BY LATE MORNING OVER THE WEST AND MID AFTERNOON OVER THE
EAST. THE PRES GRADIENT WILL WEAKEN AS A TROUGH MOVES THROUGH THE
LAKE AND LOW PRESSURE NORTH OF LAKE SUPERIOR MOVES TOWARD JAMES BAY.
NORTHWEST WINDS TO 25 KTS SHIFT TO THE NORTH TO 30 KTS LATER TUESDAY
AND TUESDAY NIGHT. MAY GET CLOSE TO GALES THOUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING. WINDS DIMINISH TO LESS THAN 25 KTS THURSDAY INTO
FRIDAY AS PRESSURE GRADIENT RELAXES. NEXT PERIOD OF STRONGER WINDS
WILL BE SATURDAY AS SOUTH WINDS INCREASE TO 30 KTS OVER THE EASTERN
LAKE AHEAD OF STRONGER LOW PRESSURE SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
942 AM EST MON NOV 25 2013
.SYNOPSIS...
ISSUED AT 449 AM EST MON NOV 25 2013
WINTRY CONDITIONS WILL BE PREVALENT ACROSS NORTHERN MICHIGAN THROUGH
THE THANKSGIVING HOLIDAY WEEK...WITH SEVERAL WEAKER WEATHER SYSTEMS
DELIVERING REPEATED SHOTS OF BOTH SYSTEM AND LAKE EFFECT SNOW. THE
FIRST WILL ARRIVE THIS MORNING...AS LOW PRESSURE TRACKS NEAR JAMES
BAY...BRINGING A ROUND OF SNOW TO MUCH OF NORTHWEST LOWER AND
EASTERN UPPER. A COLD FRONT WILL GRADUALLY WORK THROUGH THE REGION
LATER TUESDAY...BRINGING RENEWED COLD CONDITIONS ALONG WITH MORE
LAKE EFFECT SNOW. THAT GENERAL TREND WILL CONTINUE INTO THANKSGIVING
DAY...BEFORE QUIET WEATHER MAKES A RETURN TOWARD NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 930 AM EST MON NOV 25 2013
QUICK SHOT OF LAKE ENHANCED SNOW CONTINUES TO IMPACT EAST UPPER
AND NW LOWER THIS MORNING...AS SHORT WAVE AND ASSOCIATED DEEP MOISTURE
SWINGS THROUGH THE REGION. OVERALL LAKE CONTRIBUTION NOT
GREAT...WITH WATER TEMPS NEAR +8C AND 850 MB TEMPS AROUND -6C
(IDEA FURTHER SUPPORTED BY 12Z APX/GRB SOUNDINGS).
THAT SAID...COMBINATION OF ONGOING SNOW BURST AND CONTINUED GUSTY
WINDS WILL STILL RESULT IN NEAR-ADVISORY CONDITIONS NEXT SEVERAL
HOURS WITH LOCALLY DIFFICULT TRAVEL. HOWEVER...AS DEEPER MOISTURE
DEPARTS AND ONLY MARGINAL LAKE CONTRIBUTIONS LINGER...SUSPECT A
MARKED DECREASE IN SNOW SHOWER INTENSITY EARLY THIS AFTERNOON. FOR
THIS REASON...EXPECT 2-4 INCH SNOW AMOUNTS /MAINLY NW LOWER/ TO
HOLD FOR THE DAY.
UPDATE ISSUED AT 629 AM EST MON NOV 25 2013
DEEP MOISTURE OUT AHEAD OF AN ADVANCING COLD FRONT IS STARTING TO
DEVELOP SNOWS ACROSS FAR NRN LAKE MICHIGAN AND THROUGH THE STRAITS
REGION. STILL DEFINITELY EXPECTING A RAPID PRODUCTION AND
INTENSIFICATION OF SNOWS IN A SW TO NE ORIENTED BAND...COMBINED
WITH VERY STRONG SW WIND GUSTS TO 50 MPH. THIS WILL BRING A PERIOD
OF MODERATE TO HEAVY SNOWS ACROSS MUCH OF NW LOWER AND EASTERN
SECTIONS OF CHIP/MACK COUNTIES THIS MORNING. ALREADY ISSUED THE
INITIAL SPS ALERTING OF RAPIDLY DEVELOPING HAZARDOUS DRIVING
CONDITIONS. FOLKS...PLEASE ALLOW EXTRA TIME TO REACH YOUR
DESTINATION. DID INCREASE SNOWFALL ACROSS AN AREAS SURROUNDING
LEELANAU COUNTY...WHERE A LONGER PERIOD OF SNOWS ARE EXPECTED THIS
MORNING. OTHERWISE...THE FORECAST IS IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 449 AM EST MON NOV 25 2013
WELL...THAT WAS A NICE 12-ISH HOUR RESPITE FROM THE ACTIVE WEATHER.
NOW IT`S GAME ON ONCE AGAIN...WITH THE MAIN FORECAST ISSUES BEING OF
THE LAKE EFFECT/ENHANCEMENT VARIETY...ALONG WITH WIND ISSUES THROUGH
THE DAY TODAY. EARLY MORNING ANALYSIS PLACES VERY WEAK SHORTWAVE
RIDGE AXIS JUST TO THE EAST OF NORTHERN MICHIGAN...WITH DEEP AND
QUITE STRONG SOUTHWESTERLY FLOW WELL RAMPED UP ACROSS THE NORTHERN
LAKES IN ADVANCE OF ANOTHER STRONG UPPER WAVE QUICKLY AMPLIFYING
THROUGH SOUTHERN MANITOBA. INITIAL PUSH OF THAT WARM ADVECTION
EARLIER LED TO A BRIEF AXIS OF LIGHT SNOW MARCHING THROUGH
NORTHERN/EASTERN AREAS...WITH SECONDARY SURGE OF MUCH DEEPER AND
STRONGER ASCENT GOING INTO GRADUAL TOP-DOWN SATURATION OFF TO OUR
WEST AT THE MOMENT...AS EVIDENCED BY CEILINGS FALLING 5-8KFT OVER
THE PAST FEW HOURS. MEANWHILE...QUITE THE WINDY CONDITIONS HAVE
SHOWN UP RECENTLY AS CORE OF RATHER IMPRESSIVE 45-55 KNOT FLOW IS
ROLLING OVERHEAD...COMBINING WITH A REMNANT UNSTABLE AIRMASS ACROSS
THE LAKES TO PRODUCE SOME RATHER BEEFY WIND GUSTS PUSHING 50 MPH
ALONG THE LAKE MICHIGAN SHORE.
THE ABOVE MENTIONED WARM ADVECTION WILL BE IMPORTANT FOR OUR AREA
THIS MORNING...AS THE ADDED MOISTURE (FROM AN INITIALLY QUITE DRY
AIRMASS) GIVES A BIG BOOST OVER LAKE MICHIGAN. ALREADY SEEING THE
FIRST HINTS OF THIS RIGHT NOW...BUT THE THOUGHT IS THAT DEEPER
MOISTURE OVERRIDING THE LAKE WILL GO INTO THE RAPID PRODUCTION OF A
SOUTHWEST FLOW LAKE BAND THE NEXT FEW HOURS...WHICH WILL ULTIMATELY
GET PUNTED ONSHORE AS THE SHARP UPPER WAVE OVER MANITOBA WORKS
TOWARD OUR AREA. THESE TYPES OF SETUPS ALWAYS HAVE TROUBLE WRITTEN
ALL OVER THEM FROM AN IMPACT STANDPOINT...AS THERE SHOULD BE A
COUPLE HOUR WINDOW FOR SOME HEAVY SNOW TO FALL UP AND DOWN THE LAKE
MICHIGAN SHORELINE COUNTIES...AND PROBABLY EVEN FARTHER INLAND INTO
THE HIGHER TERRAIN WHERE UPSLOPE TYPICALLY WORKS ITS MAGIC IN SUCH A
SETUP. GIVEN WARMING THERMAL PROFILES...SNOW TO LIQUID RATIOS SHOULD
BE RATHER LOW...AS EVIDENCED BY A QUITE DEEP ISOTHERMAL LAYER AROUND
-6C PER FORECAST RAOBS...MAKING FOR MORE OF A GREASY/SLIPPERY SNOW.
THROW IN SOME QUITE GUSTY WINDS AND THE STAGE IS PROBABLY SET FOR A
PERIOD OF SLOPPY TRAVEL/LOW VSBYS ACROSS PRIMARILY NORTHWEST
LOWER...WITH A QUICK 2-3" OF SNOW EXPECTED TO FALL. LOCAL 4/12KM APX
WRF AND RECENT HRRR RUNS ARE EVEN MORE IMPRESSIVE...PAINTING AN AXIS
OF 0.4" OF LIQUID UP TOWARD CHARLEVOIX/EMMET/CHEBOYGAN/OTSEGO/ANTRIM
COUNTIES...WITH A SECONDARY MAXIMUM NEAR CADILLAC. GIVEN THE
EXPECTED LOWER RATIOS...SHOULDN`T SEE ACCUMULATION GET OUT OF
HAND...EVEN IF THE HIGHER QPF FORECASTS VERIFY. NOT SURE THIS WILL
BE WORTHY OF A WINTER WEATHER HEADLINE - PROBABLY MORE LIKE AN
SPS...ESPECIALLY CONSIDERING THE WORST CONDITIONS SHOULD OCCUR JUST
AFTER THE MORNING COMMUTE (MAINLY 9AM-1PM).
WINDS WILL SUBSIDE HEADING INTO THE AFTERNOON AS THE CORE OF
STRONGEST 950-900MB FLOW EXITS EAST...ALL WHILE DEEPER MOISTURE ALSO
STRIPS OUT. THAT LEAVES US IN MORE OF A LIGHT SNOW SHOWERS/SNIZZLE
REGIME FOR MUCH OF THE AFTERNOON AS SOUTHWEST FLOW CONTINUES BUT
WHILE CLOUD TOP TEMPS HOVER ONLY AROUND -8C. PROBABLY NOT LOOKING AT
MUCH ADDITIONAL ACCUMULATION FOR MOST AREAS THROUGH LATE AFTERNOON.
HOWEVER...MORE ISSUES SHOW UP BY EARLY EVENING WITH PERSISTENT HINTS
OF A STRONGER FRONTAL SNOW BAND BEING BROUGHT ASHORE INTO EASTERN
UPPER AS LOW PRESSURE NEARS THE SOUTHERN TIP OF JAMES BAY AND SWINGS
A COLD FRONT THROUGH THE EASTERN U.P. THAT FEATURE WILL IN ALL
LIKELIHOOD BECOME ABSORBED INTO THE LAKE AGGREGATE TROUGH OVER
EASTERN LAKE SUPERIOR...WITH PERHAPS EVEN A WEAK CIRCULATION CENTER
DEVELOPING IN RESPONSE TO YET ANOTHER STRONG UPPER WAVE ENTERING THE
ARROWHEAD OF MINNESOTA. THAT SETUP COULD LEAD TO ALL KINDS OF
MESOSCALE GARBAGE...BUT THE CLEAR SIGNAL IS FOR AN ENHANCED
CONVERGENCE BAND TO SKIRT FAR NORTHERN CHIPPEWA COUNTY...MAINLY
TOWARD PARADISE/WHITEFISH POINT...WITH MAYBE A COUPLE INCHES
POSSIBLE. FARTHER SOUTH...LOOKING LIKE PERSISTENT MORE NEBULOUS SNOW
SHOWERS WILL CONTINUE OVERNIGHT FOR SOUTHWEST FLOW AREAS ACROSS
NORTHWEST LOWER UP TOWARD DRUMMOND ISLAND. WAS A LITTLE CONCERNED
ABOUT SOME DRIZZLE POSSIBILITIES GIVEN INITIALLY SHALLOW NATURE OF
MOISTURE...BUT GRADUAL INTRUSION OF COLDER AIR ALOFT SHOULD FAVOR
ICE IN THE CLOUDS AS CLOUD TOP TEMPS END UP AROUND -12C BY 06Z. NO
MAJOR ACCUMULATION FORESEEN FOR NORTHERN LOWER OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 449 AM EST MON NOV 25 2013
A VERY ACTIVE AND RAPIDLY CHANGING WEATHER PATTERN WILL REMAIN
LOCKED IN ACROSS THE GREAT LAKES THROUGH THE THANKSGIVING HOLIDAY
WITH A SERIES OF SHORTWAVES AND SHOTS OF COLDER CANADIAN AIR
RESULTING IN A COUPLE OF ROUNDS OF LAKE EFFECT AND LAKE ENHANCED
SNOWFALL. THIS WILL ALSO PREVENT US FROM ANY SIGNIFICANT WARMING FOR
THE NEXT SEVERAL DAYS. A FAIRLY QUIET PERIOD OF WEATHER IS THEN
ANTICIPATED FOR FRIDAY THROUGH THE WEEKEND.
TUESDAY THROUGH WEDNESDAY NIGHT...A SIMILAR SET UP LIKE TODAY...IS
EXPECTED FOR TUESDAY WITH NEXT VIGOROUS SHORTWAVE...COLD FRONT AND
DEEPER MOISTURE ANTICIPATED TO MOVE IN ACROSS NRN MICHIGAN. THIS
TIME AROUND...WE WILL HAVE A BIT DEEPER INSTABILITY BUT LESS WIND.
WEST/WSW FLOW AHEAD OF THIS FRONT...H8 TEMPS COLDER IN THE -10C TO
-11C RANGE AND INVERSION HEIGHTS TO 7KFT WILL INCREASE TO NEAR 9KFT
WITH COLD ADVECTION THROUGH THE DAY...BUT A DRAMATIC SHIFT IN WINDS
TO OUT OF THE NNW INTO TUESDAY EVENING. MOISTURE IN THE LOWEST
LEVELS ARE STARTING TO LOOK A BIT MORE MOISTURE...MORE SO ON THIS
RUN OF THE BUFR SOUNDINGS. THE MOST IMPRESSIVE LES PARAMETERS ARE
REALLY FOCUSED TUESDAY EVENING AFTER THE FLOW TURNS NORTHERLY WITH
DEEPEST INSTABILITY WITH PASSAGE OF UPPER TROUGH AXIS/COLD AIR
ALOFT. THIS WILL FOCUS THE BEST ACCUMULATION POTENTIAL ACROSS THE
GTV BAY REGION AND AREAS SOUTH...WHERE ALSO...GUSTY WINDS COULD
LEAD TO BLOWING AND DRIFTING ISSUES. A CONSERVATIVE 3-6 INCHES OF
SNOW WILL BE POSSIBLE IN THIS REGION TUESDAY-TUESDAY NIGHT...LEADING
TO THE MOST HAZARDOUS DRIVING CONDITIONS EXPECTED IN THE LONG TERM
PORTION OF THE FORECAST. THE AIR MASS DRIES WITH LOWERING INVERSION
HEIGHTS INTO WEDNESDAY...HOWEVER CONTINUED COLD ADVECTION AND BEST
FETCH INTO GTV BAY WILL LEAD TO ANOTHER 1-2 INCHES OF SNOW
THERE...WHILE AMOUNTS ARE LESS IMPRESSIVE ELSEWHERE. FAR NE LOWER
NEAR ROGERS CITY/ALPENA AND OSCODA WILL SEE A SMATTERING OF 1 TO
MAYBE 3 INCH LOCAL AMOUNTS TUESDAY NIGHT INTO WEDNESDAY. WEDNESDAY
NIGHT...INVADING HIGHER PRESSURE AND LIGHTER WINDS FOR A LESSER
THREAT TO ANYTHING SIGNIFICANT IN THE SNOW DEPARTMENT.
HOWEVER...WILL HAVE TO KEEP AN EYE ON NEXT INCOMING SHORTWAVE AND
WARM ADVECTION OVER THE TOP OF THE REMAINING INSTABILITY...ALTHOUGH
MOST AREAS...LOOK TO HAVE A DISCONNECT FROM THE MOISTURE AND
ENHANCEMENT SEEDED FROM ALOFT. SLOWLY BACKING LOW LEVEL WINDS WILL
FOCUS ANY EMERGING THREAT OF RENEWED SNOW IN AND AROUND LAKE
MICHIGAN.
THANKSGIVING DAY AND NIGHT...THIS INCOMING WAVE IS RATHER WEAK
COMPARED TO IT`S PREDECESSORS....ALTHOUGH THE WARM ADVECTION/SEEDING
ALOFT DOES LOOK TO STILL HAVE SOME SORT OF ENHANCEMENT TO THE LAKE
EFFECT THROUGH THE HOLIDAY AND THURSDAY NIGHT. WINDS ARE EXPECTED TO
BE FAIRLY LIGHT...AND NOW SHIFTING ALL AROUND TO THE SW AS THIS
ENHANCEMENT PROCESS IN UNDERWAY...SPREADING SNOWS AROUND LAKE
MICHIGAN WITH LESS INLAND PENETRATION. THESE FINER DETAILS WILL
REALLY HAVE TO BE EXAMINED FURTHER OVER THE NEXT COUPLE OF DAYS TO
PROVIDE A MORE DETAILED HOLIDAY FORECAST. WIND DIRECTIONS AND SPEEDS
BEING THE MOST CRUCIAL...WHICH HAS A BIT OF UNCERTAINTY.
FRIDAY THROUGH SUNDAY...THIS WEAKER WAVE EXITS FRIDAY WITH SHALLOW
MID LEVEL RIDGING...AHEAD OF NEXT ADVERTISED SHORTWAVE ARRIVING
SATURDAY. A WEAK COLD FRONT LAYS ACROSS/WASHES OUT OVER NRN
MICHIGAN. COULD BE ONE LAST HOORAH OF SOME WEAKER LAKE EFFECT...BUT
THIS APPEARS TO BE THE LEAST OF CONCERN IN THE SERIES OF LAKE EFFECT
EVENTS. THIS MAINLY DUE TO THE CONTINUED LOW LEVEL WARM ADVECTION
AND GRADUAL EROSION OF THE OVERLAKE INSTABILITY. WILL HAVE RATHER
SMALL CHANCES FOR SNOW IN AND AROUND LAKE MICHIGAN IN THE SW FLOW
THAT PERSISTS INTO SUNDAY. TEMPERATURES WILL MODERATE BACK INTO THE
LOWER HALF OF THE 30S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 629 AM EST MON NOV 25 2013
HIGH LEVEL OF CONCERN THIS MORNING FOR THE AVIATION COMMUNITY. A
BAND OF MODERATE TO HEAVY SNOWFALL WILL ENTER INTO THE NW LOWER
AIRPORTS STARTING WITH PLN AT THE START OF THE TAF PERIOD...AND
REACHING TVC/MBL A FEW HOURS LATER. THIS BAND OF SNOW WILL RAPIDLY
INTENSIFY AND INCREASE IN COVERAGE THIS MORNING...AND COMBINE WITH
VERY STRONG WIND GUSTS OUT OF THE SW...MAXING OUT AT 40-50
MPH...ESPECIALLY AT MBL. THESE WINDS HAVE ALREADY SUBSTANTIALLY
MIXED DOWN TO THE SFC...AND THIS MECHANICAL MIXING IS STRONG
ENOUGH TO ELIMINATE ALL MENTION OF LLWS...BUT IT`S STILL BLOWING
VERY HARD ALOFT. WILL BRING IN A PERIOD OF IFR AT ALL AIRPORTS
EXCEPT APN...WHICH WILL LIKELY JUST SEE SOME MVFR CONDITION LATER
THIS MORNING/MIDDAY.
LAKE EFFECT SNOWS WILL CONTINUE THROUGH THE DAY AND NIGHT IN
DEVELOPING MORE WESTERLY FLOW...WHICH DOES DECREASE THROUGH
THE LATTER HALF OF THE DAY AN NIGHT. THIS PRIMARILY AFFECTS PLN
WHERE MVFR CONDITIONS WILL BE THE RULE. PERIODS OF MVFR CIGS/VSBYS
FOR TVC...TO A LESSER DEGREE AT MBL. SNOWS NOT GOING TO REACH APN.
A QUICK 1-3 INCHES OF SNOW IS DEFINITELY POSSIBLE THIS MORNING
WITH LIQUID TO SNOW RATIOS ON THE LOW END AT AROUND 10:1.
OVERALL CONFIDENCE IS HIGH FOR THE EVOLUTION OF THE DESCRIBED
WEATHER.
&&
.MARINE...
ISSUED AT 449 AM EST MON NOV 25 2013
A WINDY ONE OUT THERE TO START...WITH GALES FOR MOST OF THE WATERS.
THOSE WINDS WILL SUBSIDE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING...THOUGH WILL REMAIN A BIT GUSTY IN THE 20-25 KNOT RANGE AS
IS TYPICAL FOR LATE NOVEMBER. WINDS WILL GRADUALLY COME AROUND TO
THE NORTHWEST ON TUESDAY AND THEN NORTH TUESDAY NIGHT AND
WEDNESDAY...WITH CONTINUED GUSTS OF 25-30 KNOTS EXPECTED. COULD SEE
A PERIOD OF GALES ON MAINLY LAKE MICHIGAN SOMETIME TUESDAY NIGHT...
BUT CONFIDENCE IN THAT IS LOW AT THIS TIME. HIGH PRESSURE WILL
FINALLY WIN THE BATTLE BY THURSDAY...WITH A RETURN TO A BRIEF PERIOD
OF MUCH LIGHTER WINDS OF THE 15 KNOTS OF LESS VARIETY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ015-016-019-
020-025-031.
LH...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...BS
SYNOPSIS...DL
SHORT TERM...DL
LONG TERM...SD
AVIATION...SD
MARINE...DL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
645 AM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM EST MON NOV 25 2013
AS A STRONG DISTURBANCE OVER NW ONTARIO AND ITS ATTENDANT SFC COLD
FRONT DIGS SE INTO THE NRN GREAT LAKES...EXPECT MVFR CIGS TO
DEVELOP OVER THE W AT IWD AND CMX THIS MORNING. WITH A STRONG
UPSLOPE W WIND...THE FROPA WILL ALSO BRING MVFR VSBY FOR A COUPLE
HOURS AT CMX THIS MORNING. ALTHOUGH SOME MVFR CIGS MAY OCCUR AT SAW
WITH THE FROPA...DOWNSLOPE NATURE OF THE FLOW INDICATES THIS
CONDITION WL BE MARGINAL AND MAY REMAIN VFR. THE BEST CHANCE OF MORE
PERSISTENT MVFR WX WILL BE AT CMX WITH A MORE PRONOUNCED UPSLOPE W
WIND...WHICH WILL GUST AS HIGH AS 30 KTS WITH A SLOW INFLUX
OF COLDER AIR/MORE DESTABILIZATION. THE APPROACH OF ANOTHER
DISTURBANCE AND LOW PRES TROF MAY BRING ANOTHER ROUND OF HEAVIER
LES TO CMX THIS EVENING...SO FCST IFR VSBYS AT THIS SITE THEN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 533 AM EST MON NOV 25 2013
SW TO W GALES OVER LAKE SUPERIOR THIS MORNING ARE EXPECTED TO
DIMINISH BY LATE MORNING OVER THE WEST AND MID AFTERNOON OVER THE
EAST. THE PRES GRADIENT WILL WEAKEN AS A TROUGH MOVES THROUGH THE
LAKE AND LOW PRESSURE NORTH OF LAKE SUPERIOR MOVES TOWARD JAMES BAY.
NORTHWEST WINDS TO 25 KTS SHIFT TO THE NORTH TO 30 KTS LATER TUESDAY
AND TUESDAY NIGHT. MAY GET CLOSE TO GALES THOUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING. WINDS DIMINISH TO LESS THAN 25 KTS THURSDAY INTO
FRIDAY AS PRESSURE GRADIENT RELAXES. NEXT PERIOD OF STRONGER WINDS
WILL BE SATURDAY AS SOUTH WINDS INCREASE TO 30 KTS OVER THE EASTERN
LAKE AHEAD OF STRONGER LOW PRESSURE SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ013-014.
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL NOON EST TODAY FOR LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 644 AM EST MON NOV 25 2013
AS A STRONG DISTURBANCE OVER NW ONTARIO AND ITS ATTENDANT SFC COLD
FRONT DIGS SE INTO THE NRN GREAT LAKES...EXPECT MVFR CIGS TO
DEVELOP OVER THE W AT IWD AND CMX THIS MORNING. WITH A STRONG
UPSLOPE W WIND...THE FROPA WILL ALSO BRING MVFR VSBY FOR A COUPLE
HOURS AT CMX THISMORNING. ALTHOUGH SOME MVFR CIGS MAY OCCUR AT SAW
WITH THE FROPA...DOWNSLOPE NATURE OF THE FLOW INDICATES THIS
CONDITION WL BE MARGINAL AND MAY REMAIN VFR. THE BEST CHANCE OF MORE
PERSISTENT MVFR WX WILL BE AT CMX WITH A MORE PRONOUNCED UPSLOPE W
WIND...WHICH WILL GUST AS HIGH AS 30 KTS WITH A SLOW INFLUX
OF COLDER AIR/MORE DESTABILIZATION. THE APPROACH OF ANOTHER
DISTURBANCE AND LOW PRES TROF MAY BRING ANOTHER ROUND OF HEAVIER
LES TO CMX THIS EVENING...SO FCST IFR VSBYS AT THIS SITE THEN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 533 AM EST MON NOV 25 2013
SW TO W GALES OVER LAKE SUPERIOR THIS MORNING ARE EXPECTED TO
DIMINISH BY LATE MORNING OVER THE WEST AND MID AFTERNOON OVER THE
EAST. THE PRES GRADIENT WILL WEAKEN AS A TROUGH MOVES THROUGH THE
LAKE AND LOW PRESSURE NORTH OF LAKE SUPERIOR MOVES TOWARD JAMES BAY.
NORTHWEST WINDS TO 25 KTS SHIFT TO THE NORTH TO 30 KTS LATER TUESDAY
AND TUESDAY NIGHT. MAY GET CLOSE TO GALES THOUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING. WINDS DIMINISH TO LESS THAN 25 KTS THURSDAY INTO
FRIDAY AS PRESSURE GRADIENT RELAXES. NEXT PERIOD OF STRONGER WINDS
WILL BE SATURDAY AS SOUTH WINDS INCREASE TO 30 KTS OVER THE EASTERN
LAKE AHEAD OF STRONGER LOW PRESSURE SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ013-014.
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL NOON EST TODAY FOR LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GAYLORD MI
630 AM EST MON NOV 25 2013
.SYNOPSIS...
ISSUED AT 449 AM EST MON NOV 25 2013
WINTRY CONDITIONS WILL BE PREVALENT ACROSS NORTHERN MICHIGAN THROUGH
THE THANKSGIVING HOLIDAY WEEK...WITH SEVERAL WEAKER WEATHER SYSTEMS
DELIVERING REPEATED SHOTS OF BOTH SYSTEM AND LAKE EFFECT SNOW. THE
FIRST WILL ARRIVE THIS MORNING...AS LOW PRESSURE TRACKS NEAR JAMES
BAY...BRINGING A ROUND OF SNOW TO MUCH OF NORTHWEST LOWER AND
EASTERN UPPER. A COLD FRONT WILL GRADUALLY WORK THROUGH THE REGION
LATER TUESDAY...BRINGING RENEWED COLD CONDITIONS ALONG WITH MORE
LAKE EFFECT SNOW. THAT GENERAL TREND WILL CONTINUE INTO THANKSGIVING
DAY...BEFORE QUIET WEATHER MAKES A RETURN TOWARD NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 629 AM EST MON NOV 25 2013
DEEP MOISTURE OUT AHEAD OF AN ADVANCING COLD FRONT IS STARTING TO
DEVELOP SNOWS ACROSS FAR NRN LAKE MICHIGAN AND THROUGH THE STRAITS
REGION. STILL DEFINITELY EXPECTING A RAPID PRODUCTION AND
INTENSIFICATION OF SNOWS IN A SW TO NE ORIENTED BAND...COMBINED
WITH VERY STRONG SW WIND GUSTS TO 50 MPH. THIS WILL BRING A PERIOD
OF MODERATE TO HEAVY SNOWS ACROSS MUCH OF NW LOWER AND EASTERN
SECTIONS OF CHIP/MACK COUNTIES THIS MORNING. ALREADY ISSUED THE
INITIAL SPS ALERTING OF RAPIDLY DEVELOPING HAZARDOUS DRIVING
CONDITIONS. FOLKS...PLEASE ALLOW EXTRA TIME TO REACH YOUR
DESTINATION. HIGH PROFILE VEHICLES WILL HAVE AN EXTRA BOOST TO THE
HAZARD DUE TO THE STRONG WINDS. DID INCREASE SNOWFALL ACROSS AN
AREAS SURROUNDING LEELANAU COUNTY...WHERE A LONGER PERIOD OF SNOWS
ARE EXPECTED THIS MORNING. OTHERWISE...THE FORECAST IS IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 449 AM EST MON NOV 25 2013
WELL...THAT WAS A NICE 12-ISH HOUR RESPITE FROM THE ACTIVE WEATHER.
NOW IT`S GAME ON ONCE AGAIN...WITH THE MAIN FORECAST ISSUES BEING OF
THE LAKE EFFECT/ENHANCEMENT VARIETY...ALONG WITH WIND ISSUES THROUGH
THE DAY TODAY. EARLY MORNING ANALYSIS PLACES VERY WEAK SHORTWAVE
RIDGE AXIS JUST TO THE EAST OF NORTHERN MICHIGAN...WITH DEEP AND
QUITE STRONG SOUTHWESTERLY FLOW WELL RAMPED UP ACROSS THE NORTHERN
LAKES IN ADVANCE OF ANOTHER STRONG UPPER WAVE QUICKLY AMPLIFYING
THROUGH SOUTHERN MANITOBA. INITIAL PUSH OF THAT WARM ADVECTION
EARLIER LED TO A BRIEF AXIS OF LIGHT SNOW MARCHING THROUGH
NORTHERN/EASTERN AREAS...WITH SECONDARY SURGE OF MUCH DEEPER AND
STRONGER ASCENT GOING INTO GRADUAL TOP-DOWN SATURATION OFF TO OUR
WEST AT THE MOMENT...AS EVIDENCED BY CEILINGS FALLING 5-8KFT OVER
THE PAST FEW HOURS. MEANWHILE...QUITE THE WINDY CONDITIONS HAVE
SHOWN UP RECENTLY AS CORE OF RATHER IMPRESSIVE 45-55 KNOT FLOW IS
ROLLING OVERHEAD...COMBINING WITH A REMNANT UNSTABLE AIRMASS ACROSS
THE LAKES TO PRODUCE SOME RATHER BEEFY WIND GUSTS PUSHING 50 MPH
ALONG THE LAKE MICHIGAN SHORE.
THE ABOVE MENTIONED WARM ADVECTION WILL BE IMPORTANT FOR OUR AREA
THIS MORNING...AS THE ADDED MOISTURE (FROM AN INITIALLY QUITE DRY
AIRMASS) GIVES A BIG BOOST OVER LAKE MICHIGAN. ALREADY SEEING THE
FIRST HINTS OF THIS RIGHT NOW...BUT THE THOUGHT IS THAT DEEPER
MOISTURE OVERRIDING THE LAKE WILL GO INTO THE RAPID PRODUCTION OF A
SOUTHWEST FLOW LAKE BAND THE NEXT FEW HOURS...WHICH WILL ULTIMATELY
GET PUNTED ONSHORE AS THE SHARP UPPER WAVE OVER MANITOBA WORKS
TOWARD OUR AREA. THESE TYPES OF SETUPS ALWAYS HAVE TROUBLE WRITTEN
ALL OVER THEM FROM AN IMPACT STANDPOINT...AS THERE SHOULD BE A
COUPLE HOUR WINDOW FOR SOME HEAVY SNOW TO FALL UP AND DOWN THE LAKE
MICHIGAN SHORELINE COUNTIES...AND PROBABLY EVEN FARTHER INLAND INTO
THE HIGHER TERRAIN WHERE UPSLOPE TYPICALLY WORKS ITS MAGIC IN SUCH A
SETUP. GIVEN WARMING THERMAL PROFILES...SNOW TO LIQUID RATIOS SHOULD
BE RATHER LOW...AS EVIDENCED BY A QUITE DEEP ISOTHERMAL LAYER AROUND
-6C PER FORECAST RAOBS...MAKING FOR MORE OF A GREASY/SLIPPERY SNOW.
THROW IN SOME QUITE GUSTY WINDS AND THE STAGE IS PROBABLY SET FOR A
PERIOD OF SLOPPY TRAVEL/LOW VSBYS ACROSS PRIMARILY NORTHWEST
LOWER...WITH A QUICK 2-3" OF SNOW EXPECTED TO FALL. LOCAL 4/12KM APX
WRF AND RECENT HRRR RUNS ARE EVEN MORE IMPRESSIVE...PAINTING AN AXIS
OF 0.4" OF LIQUID UP TOWARD CHARLEVOIX/EMMET/CHEBOYGAN/OTSEGO/ANTRIM
COUNTIES...WITH A SECONDARY MAXIMUM NEAR CADILLAC. GIVEN THE
EXPECTED LOWER RATIOS...SHOULDN`T SEE ACCUMULATION GET OUT OF
HAND...EVEN IF THE HIGHER QPF FORECASTS VERIFY. NOT SURE THIS WILL
BE WORTHY OF A WINTER WEATHER HEADLINE - PROBABLY MORE LIKE AN
SPS...ESPECIALLY CONSIDERING THE WORST CONDITIONS SHOULD OCCUR JUST
AFTER THE MORNING COMMUTE (MAINLY 9AM-1PM).
WINDS WILL SUBSIDE HEADING INTO THE AFTERNOON AS THE CORE OF
STRONGEST 950-900MB FLOW EXITS EAST...ALL WHILE DEEPER MOISTURE ALSO
STRIPS OUT. THAT LEAVES US IN MORE OF A LIGHT SNOW SHOWERS/SNIZZLE
REGIME FOR MUCH OF THE AFTERNOON AS SOUTHWEST FLOW CONTINUES BUT
WHILE CLOUD TOP TEMPS HOVER ONLY AROUND -8C. PROBABLY NOT LOOKING AT
MUCH ADDITIONAL ACCUMULATION FOR MOST AREAS THROUGH LATE AFTERNOON.
HOWEVER...MORE ISSUES SHOW UP BY EARLY EVENING WITH PERSISTENT HINTS
OF A STRONGER FRONTAL SNOW BAND BEING BROUGHT ASHORE INTO EASTERN
UPPER AS LOW PRESSURE NEARS THE SOUTHERN TIP OF JAMES BAY AND SWINGS
A COLD FRONT THROUGH THE EASTERN U.P. THAT FEATURE WILL IN ALL
LIKELIHOOD BECOME ABSORBED INTO THE LAKE AGGREGATE TROUGH OVER
EASTERN LAKE SUPERIOR...WITH PERHAPS EVEN A WEAK CIRCULATION CENTER
DEVELOPING IN RESPONSE TO YET ANOTHER STRONG UPPER WAVE ENTERING THE
ARROWHEAD OF MINNESOTA. THAT SETUP COULD LEAD TO ALL KINDS OF
MESOSCALE GARBAGE...BUT THE CLEAR SIGNAL IS FOR AN ENHANCED
CONVERGENCE BAND TO SKIRT FAR NORTHERN CHIPPEWA COUNTY...MAINLY
TOWARD PARADISE/WHITEFISH POINT...WITH MAYBE A COUPLE INCHES
POSSIBLE. FARTHER SOUTH...LOOKING LIKE PERSISTENT MORE NEBULOUS SNOW
SHOWERS WILL CONTINUE OVERNIGHT FOR SOUTHWEST FLOW AREAS ACROSS
NORTHWEST LOWER UP TOWARD DRUMMOND ISLAND. WAS A LITTLE CONCERNED
ABOUT SOME DRIZZLE POSSIBILITIES GIVEN INITIALLY SHALLOW NATURE OF
MOISTURE...BUT GRADUAL INTRUSION OF COLDER AIR ALOFT SHOULD FAVOR
ICE IN THE CLOUDS AS CLOUD TOP TEMPS END UP AROUND -12C BY 06Z. NO
MAJOR ACCUMULATION FORESEEN FOR NORTHERN LOWER OVERNIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 449 AM EST MON NOV 25 2013
A VERY ACTIVE AND RAPIDLY CHANGING WEATHER PATTERN WILL REMAIN
LOCKED IN ACROSS THE GREAT LAKES THROUGH THE THANKSGIVING HOLIDAY
WITH A SERIES OF SHORTWAVES AND SHOTS OF COLDER CANADIAN AIR
RESULTING IN A COUPLE OF ROUNDS OF LAKE EFFECT AND LAKE ENHANCED
SNOWFALL. THIS WILL ALSO PREVENT US FROM ANY SIGNIFICANT WARMING FOR
THE NEXT SEVERAL DAYS. A FAIRLY QUIET PERIOD OF WEATHER IS THEN
ANTICIPATED FOR FRIDAY THROUGH THE WEEKEND.
TUESDAY THROUGH WEDNESDAY NIGHT...A SIMILAR SET UP LIKE TODAY...IS
EXPECTED FOR TUESDAY WITH NEXT VIGOROUS SHORTWAVE...COLD FRONT AND
DEEPER MOISTURE ANTICIPATED TO MOVE IN ACROSS NRN MICHIGAN. THIS
TIME AROUND...WE WILL HAVE A BIT DEEPER INSTABILITY BUT LESS WIND.
WEST/WSW FLOW AHEAD OF THIS FRONT...H8 TEMPS COLDER IN THE -10C TO
-11C RANGE AND INVERSION HEIGHTS TO 7KFT WILL INCREASE TO NEAR 9KFT
WITH COLD ADVECTION THROUGH THE DAY...BUT A DRAMATIC SHIFT IN WINDS
TO OUT OF THE NNW INTO TUESDAY EVENING. MOISTURE IN THE LOWEST
LEVELS ARE STARTING TO LOOK A BIT MORE MOISTURE...MORE SO ON THIS
RUN OF THE BUFR SOUNDINGS. THE MOST IMPRESSIVE LES PARAMETERS ARE
REALLY FOCUSED TUESDAY EVENING AFTER THE FLOW TURNS NORTHERLY WITH
DEEPEST INSTABILITY WITH PASSAGE OF UPPER TROUGH AXIS/COLD AIR
ALOFT. THIS WILL FOCUS THE BEST ACCUMULATION POTENTIAL ACROSS THE
GTV BAY REGION AND AREAS SOUTH...WHERE ALSO...GUSTY WINDS COULD
LEAD TO BLOWING AND DRIFTING ISSUES. A CONSERVATIVE 3-6 INCHES OF
SNOW WILL BE POSSIBLE IN THIS REGION TUESDAY-TUESDAY NIGHT...LEADING
TO THE MOST HAZARDOUS DRIVING CONDITIONS EXPECTED IN THE LONG TERM
PORTION OF THE FORECAST. THE AIR MASS DRIES WITH LOWERING INVERSION
HEIGHTS INTO WEDNESDAY...HOWEVER CONTINUED COLD ADVECTION AND BEST
FETCH INTO GTV BAY WILL LEAD TO ANOTHER 1-2 INCHES OF SNOW
THERE...WHILE AMOUNTS ARE LESS IMPRESSIVE ELSEWHERE. FAR NE LOWER
NEAR ROGERS CITY/ALPENA AND OSCODA WILL SEE A SMATTERING OF 1 TO
MAYBE 3 INCH LOCAL AMOUNTS TUESDAY NIGHT INTO WEDNESDAY. WEDNESDAY
NIGHT...INVADING HIGHER PRESSURE AND LIGHTER WINDS FOR A LESSER
THREAT TO ANYTHING SIGNIFICANT IN THE SNOW DEPARTMENT.
HOWEVER...WILL HAVE TO KEEP AN EYE ON NEXT INCOMING SHORTWAVE AND
WARM ADVECTION OVER THE TOP OF THE REMAINING INSTABILITY...ALTHOUGH
MOST AREAS...LOOK TO HAVE A DISCONNECT FROM THE MOISTURE AND
ENHANCEMENT SEEDED FROM ALOFT. SLOWLY BACKING LOW LEVEL WINDS WILL
FOCUS ANY EMERGING THREAT OF RENEWED SNOW IN AND AROUND LAKE
MICHIGAN.
THANKSGIVING DAY AND NIGHT...THIS INCOMING WAVE IS RATHER WEAK
COMPARED TO IT`S PREDECESSORS....ALTHOUGH THE WARM ADVECTION/SEEDING
ALOFT DOES LOOK TO STILL HAVE SOME SORT OF ENHANCEMENT TO THE LAKE
EFFECT THROUGH THE HOLIDAY AND THURSDAY NIGHT. WINDS ARE EXPECTED TO
BE FAIRLY LIGHT...AND NOW SHIFTING ALL AROUND TO THE SW AS THIS
ENHANCEMENT PROCESS IN UNDERWAY...SPREADING SNOWS AROUND LAKE
MICHIGAN WITH LESS INLAND PENETRATION. THESE FINER DETAILS WILL
REALLY HAVE TO BE EXAMINED FURTHER OVER THE NEXT COUPLE OF DAYS TO
PROVIDE A MORE DETAILED HOLIDAY FORECAST. WIND DIRECTIONS AND SPEEDS
BEING THE MOST CRUCIAL...WHICH HAS A BIT OF UNCERTAINTY.
FRIDAY THROUGH SUNDAY...THIS WEAKER WAVE EXITS FRIDAY WITH SHALLOW
MID LEVEL RIDGING...AHEAD OF NEXT ADVERTISED SHORTWAVE ARRIVING
SATURDAY. A WEAK COLD FRONT LAYS ACROSS/WASHES OUT OVER NRN
MICHIGAN. COULD BE ONE LAST HOORAH OF SOME WEAKER LAKE EFFECT...BUT
THIS APPEARS TO BE THE LEAST OF CONCERN IN THE SERIES OF LAKE EFFECT
EVENTS. THIS MAINLY DUE TO THE CONTINUED LOW LEVEL WARM ADVECTION
AND GRADUAL EROSION OF THE OVERLAKE INSTABILITY. WILL HAVE RATHER
SMALL CHANCES FOR SNOW IN AND AROUND LAKE MICHIGAN IN THE SW FLOW
THAT PERSISTS INTO SUNDAY. TEMPERATURES WILL MODERATE BACK INTO THE
LOWER HALF OF THE 30S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 629 AM EST MON NOV 25 2013
HIGH LEVEL OF CONCERN THIS MORNING FOR THE AVIATION COMMUNITY. A
BAND OF MODERATE TO HEAVY SNOWFALL WILL ENTER INTO THE NW LOWER
AIRPORTS STARTING WITH PLN AT THE START OF THE TAF PERIOD...AND
REACHING TVC/MBL A FEW HOURS LATER. THIS BAND OF SNOW WILL RAPIDLY
INTENSIFY AND INCREASE IN COVERAGE THIS MORNING...AND COMBINE WITH
VERY STRONG WIND GUSTS OUT OF THE SW...MAXING OUT AT 40-50
MPH...ESPECIALLY AT MBL. THESE WINDS HAVE ALREADY SUBSTANTIALLY
MIXED DOWN TO THE SFC...AND THIS MECHANICAL MIXING IS STRONG
ENOUGH TO ELIMINATE ALL MENTION OF LLWS...BUT IT`S STILL BLOWING
VERY HARD ALOFT. WILL BRING IN A PERIOD OF IFR AT ALL AIRPORTS
EXCEPT APN...WHICH WILL LIKELY JUST SEE SOME MVFR CONDITION LATER
THIS MORNING/MIDDAY.
LAKE EFFECT SNOWS WILL CONTINUE THROUGH THE DAY AND NIGHT IN
DEVELOPING MORE WESTERLY FLOW...WHICH DOES DECREASE THROUGH
THE LATTER HALF OF THE DAY AN NIGHT. THIS PRIMARILY AFFECTS PLN
WHERE MVFR CONDITIONS WILL BE THE RULE. PERIODS OF MVFR CIGS/VSBYS
FOR TVC...TO A LESSER DEGREE AT MBL. SNOWS NOT GOING TO REACH APN.
A QUICK 1-3 INCHES OF SNOW IS DEFINITELY POSSIBLE THIS MORNING
WITH LIQUID TO SNOW RATIOS ON THE LOW END AT AROUND 10:1.
OVERALL CONFIDENCE IS HIGH FOR THE EVOLUTION OF THE DESCRIBED
WEATHER.
&&
.MARINE...
ISSUED AT 449 AM EST MON NOV 25 2013
A WINDY ONE OUT THERE TO START...WITH GALES FOR MOST OF THE WATERS.
THOSE WINDS WILL SUBSIDE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING...THOUGH WILL REMAIN A BIT GUSTY IN THE 20-25 KNOT RANGE AS
IS TYPICAL FOR LATE NOVEMBER. WINDS WILL GRADUALLY COME AROUND TO
THE NORTHWEST ON TUESDAY AND THEN NORTH TUESDAY NIGHT AND
WEDNESDAY...WITH CONTINUED GUSTS OF 25-30 KNOTS EXPECTED. COULD SEE
A PERIOD OF GALES ON MAINLY LAKE MICHIGAN SOMETIME TUESDAY NIGHT...
BUT CONFIDENCE IN THAT IS LOW AT THIS TIME. HIGH PRESSURE WILL
FINALLY WIN THE BATTLE BY THURSDAY...WITH A RETURN TO A BRIEF PERIOD
OF MUCH LIGHTER WINDS OF THE 15 KNOTS OF LESS VARIETY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ015-016-019-
020-025-031.
LH...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LSZ321-322.
&&
$$
UPDATE...SD
SYNOPSIS...DL
SHORT TERM...DL
LONG TERM...SD
AVIATION...SD
MARINE...DL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
533 AM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY MORNING) ISSUED AT
520 AM EST MON NOV 25 2013
A GUSTY SW WIND APRCHG 30 KTS AT IWD WL ADVECT LLVL DRY AIR INTO UPR
MI EARLY THIS MRNG...SO EXPECT VFR CONDITIONS DESPITE QUITE A BIT OF
MID CLD COVER. BUT AS A STRONG DISTURBANCE NOW NEAR LK WINNIPEG AND
ITS ATTENDANT SFC COLD FNT DIG SEWD TOWARD THE UPR LKS...EXPECT MVFR
CONDITIONS TO DVLP OVER THE W AT IWD AND CMX BY SUNRISE. WITH A
STRONG UPSLOPE W WIND...THE FROPA WL BRING IFR CONDITIONS FOR A
COUPLE HRS AT CMX DURING THE MRNG. ALTHOUGH SOME MVFR CIGS MAY OCCUR
AT SAW WITH THE FROPA...DOWNSLOPE NATURE OF THE FLOW INDICATES THIS
CONDITION WL BE MARGINAL AND MAY REMAIN VFR. THE BEST CHC OF MORE
PERSISTENT MVFR WX ON MON WL BE AT CMX WITH A MORE PRONOUNCED
UPSLOPE W WIND...WHICH WL GUST AS HI AS 30 KTS AT THIS EXPOSED
LOCATION WITH A SLOW INFLUX OF COLDER AIR/MORE DESTABILIZATION. THE
APRCH OF ANOTHER DISTURBANCE/LO PRES TROF MAY BRING ANOTHER ROUND OF
HEAVIER LES TO CMX THIS EVNG...SO FCST IFR VSBYS AT THIS SITE THEN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 533 AM EST MON NOV 25 2013
SW TO W GALES OVER LAKE SUPERIOR THIS MORNING ARE EXPECTED TO
DIMINISH BY LATE MORNING OVER THE WEST AND MID AFTERNOON OVER THE
EAST. THE PRES GRADIENT WILL WEAKEN AS A TROUGH MOVES THROUGH THE
LAKE AND LOW PRESSURE NORTH OF LAKE SUPERIOR MOVES TOWARD JAMES BAY.
NORTHWEST WINDS TO 25 KTS SHIFT TO THE NORTH TO 30 KTS LATER TUESDAY
AND TUESDAY NIGHT. MAY GET CLOSE TO GALES THOUGH TUESDAY NIGHT INTO
WEDNESDAY MORNING. WINDS DIMINISH TO LESS THAN 25 KTS THURSDAY INTO
FRIDAY AS PRESSURE GRADIENT RELAXES. NEXT PERIOD OF STRONGER WINDS
WILL BE SATURDAY AS SOUTH WINDS INCREASE TO 30 KTS OVER THE EASTERN
LAKE AHEAD OF STRONGER LOW PRESSURE SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ013-014.
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL NOON EST TODAY FOR LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY MORNING) ISSUED AT
520 AM EST MON NOV 25 2013
A GUSTY SW WIND APRCHG 30 KTS AT IWD WL ADVECT LLVL DRY AIR INTO UPR
MI EARLY THIS MRNG...SO EXPECT VFR CONDITIONS DESPITE QUITE A BIT OF
MID CLD COVER. BUT AS A STRONG DISTURBANCE NOW NEAR LK WINNIPEG AND
ITS ATTENDANT SFC COLD FNT DIG SEWD TOWARD THE UPR LKS...EXPECT MVFR
CONDITIONS TO DVLP OVER THE W AT IWD AND CMX BY SUNRISE. WITH A
STRONG UPSLOPE W WIND...THE FROPA WL BRING IFR CONDITIONS FOR A
COUPLE HRS AT CMX DURING THE MRNG. ALTHOUGH SOME MVFR CIGS MAY OCCUR
AT SAW WITH THE FROPA...DOWNSLOPE NATURE OF THE FLOW INDICATES THIS
CONDITION WL BE MARGINAL AND MAY REMAIN VFR. THE BEST CHC OF MORE
PERSISTENT MVFR WX ON MON WL BE AT CMX WITH A MORE PRONOUNCED
UPSLOPE W WIND...WHICH WL GUST AS HI AS 30 KTS AT THIS EXPOSED
LOCATION WITH A SLOW INFLUX OF COLDER AIR/MORE DESTABILIZATION. THE
APRCH OF ANOTHER DISTURBANCE/LO PRES TROF MAY BRING ANOTHER ROUND OF
HEAVIER LES TO CMX THIS EVNG...SO FCST IFR VSBYS AT THIS SITE THEN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 252 PM EST SUN NOV 24 2013
SW GALES EXPECTED OVER NORTH CENTRAL LAKE SUPERIOR AND THE NORTHERN
LAKE MICHIGAN ZONES TONIGHT INTO MON MORNING AND WILL CONTINUE THE
GALE WARNING IN LAKE SUPERIOR DUE TO CHANNELED FLOW BETWEEN THE
KEWEENAW AND ISLE ROYALE. WINDS TURN TO NORTHWEST ON MONDAY INTO
TUESDAY AND REMAIN UP TO 30 KTS. GETS CLOSE TO GALES ON LAKE
SUPERIOR AGAIN TUE NIGHT INTO WED AND WILL HAVE TO WATCH THIS EVENT
FOR NOW. WINDS THEN STAY BELOW 20 KNOTS FOR THE REST OF THE FORECAST
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ013-014.
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL NOON EST TODAY FOR LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
517 AM EST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM EST MON NOV 25 2013
WV IMAGERY AND RUC ANALYSIS INDICATED WNW MID/UPPER LEVEL FLOW FROM
CNTRL CANADA THROUGH THE GREAT LAKES WITH ONE SHORTWAVE TROUGH FROM
NW ONTARIO INTO NW MN AND ANOTHER WELL TO THE NORTH MOVING INTO NRN
SASK. AT THE SFC...A TIGHT PRES GRADIENT PREVAILED ACROSS THE WRN
GREAT LAKES BTWN A 1000 MB LOW LOCATED JUST NORTH OF THUNDER BAY
ONTARIO AND A 1036 MB RIDGE OVER THE OH VALLEY. WITH THE STRONGEST
PRES FALLS MOVING TO THE NE OF LAKE SUPERIOR...VERY STRONG SW WINDS
PERSISTED ACROSS WRN LAKE SUPERIOR AND NRN LAKE MICHIGAN. WAA
LEADING TO INCREASING STABILITY HAS LIMITED MIXING OF 45-50 KNOT
925-850 MB WINDS TOWARD THE SFC EXCEPT OVER THE RELATIVELY WARM LAKE
MICHIGAN WATERS. GUSTS IN THE 35-40 KT RANGE PERSISTED FROM FAIRPORT
TO PORT INLAND WHERE A WIND ADVISORY WAS IN EFFECT. WINDS OVER
INLAND LOCATIONS AT ESC AND ISQ WERE ONLY GUSTING TO AROUND 25
KNOTS. RADAR INDICATED WEAK RETURNS...MAINLY OVER THE ERN CWA...WITH
SOME PATCHY LIGHT SNOW OR FLURRIES SUPPORTED BY 700-300 QVECTOR CONV
AND ISENTROPIC LIFT AHEAD OF THE UPSTREAM SHRTWV.
TODAY...EXPECT WINDS TO SUBSIDE BY THE 15Z WIND ADVISORY EXPIRATION
TIME AS THE CORE OF THE STRONGEST 925-850 MB WINDS SHIFTS OFF TO THE
EAST. AS THE AREA OF LIGHT SNOW MOVES TO THE EAST...SOME LAKE
ENHANCEMENT MAY BE POSSIBLE WITH THE SW FLOW OFF OF LAKE MICHIGAN
BUT SHOULD REMAIN MAINLY TO THE SOUTH AND EAST OF THE CWA. OVER THE
KEWEENAW...AN AREA OF LOW LEVEL CONV AS WINDS VEER FROM SW TO W MAY
BRING A BRIEF PERIOD OF LAKE ENHANCED SNOW. HOWEVER...MID LEVEL
DRYING WITH THE DRY SLOT AND MARGINAL INSTABILITY WITH 850 MB TEMPS
AROUND -7C (LAKE SFC NEAR 4C) SUPPORTS ONLY CHANCE POPS WITH ANY
ACCUMULATIONS ONLY AMOUNTING TO A HALF INCH OR LESS. INCREASING
850-700 MB MOISTURE AND AND 850/700 MB TEMPS DROPPING TO -10C/-17C
WITH THE APPROACH OF THE SHRTWV WILL ALSO BRING AN INCREASE IN LAKE
ENHANCED SNOW INTO THE WEST AND THE ERN SHORELINE FROM PICTURED
ROCKS TO GRAND MARAIS.
TONIGHT...STRONGER CAA DROPPING 850 MB TEMPS TO AROUND -18C BOOSTING
LAKE INDUCED CAPES TO NEAR 700 J/KG ALONG WITH STRENGTHENING
CYCLONIC NW FLOW WILL BRING A FURTHER INCREASE IN LES INTO THE WEST.
THE HIGH RES MODELS OFFER A VARIETY OF SOLUTIONS AS TO WHERE THE
HEAVIER SNOW BANDS WILL FOCUS AND DELAY THE STRONGER VEERING WIND
SHIFT AND LOW LEVEL CONV BAND MOVING IN TIL AFT 12Z. ALTHOUGH
SEVERAL INDICATE THE GREATER SNOW POTENTIAL INTO THE KEWEENAW AND
IRONWOOD AREAS...CONFIDENCE IN IN HIGHLIGHTING ANY PARTICULAR
LOCATION IS LIMITED. SO...A GENERAL 2 TO 5 INCH FCST WAS INCLUDED
FOR MOST OF THE NW TO WNW FLOW SNOWBELTS IN THE WEST AS WELL AS
LOCATIONS NORTH OF M-28 EAST OF MUNISING.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 437 AM EST MON NOV 25 2013
EXTENT OF LAKE EFFECT SNOW AND SNOW AMOUNTS ALONG WITH THE NEED FOR
ANY ADVISORIES OR WARNINGS TUESDAY/TUESDAY NIGHT IS PRIMARY FOCUS.
IN LARGE SCALE...STRONG SHORTWAVE IN NORTHERN STREAM CURRENTLY OVER
NORTHERN MANTIOBA WILL BE CROSSING UPR MICHIGAN AND LK SUPERIOR ON
TUESDAY. NAM/GFS/ECMWF DECENT AGREEMENT WITH TIMING OF LARGER SCALE
IMPACTS AS THEY ALL SHOW H7-H5/H5-H3 Q-VECTOR CONVERGENCE INTO WESTERN
UPR MICHIGAN BEFORE 12Z TUESDAY SPREADING TO CNTRL CWA BY 18Z AND
EXITING EASTERN CWA BY 00Z WEDNESDAY. MAY SEE MINOR LGT SNOW EVEN
INTO SOUTH AS THE SHORTWAVE CROSSES THE REGION. BIGGEST IMPACT
THOUGH WILL BE ON LK EFFECT THAT BEGINS LATE TONIGHT. NAM AND GFS
FORECAST SOUNDINGS SHOW GOOD RESPONSE FM THE WAVE WITH INVERSION
HEIGHTS RISING ABOVE 5KFT LATE TONIGHT AND SPIKING UP TO 8-10KFT BY
MIDDAY TUESDAY. LAKE EQUILIBRIUM LEVELS INCREASE TO 13KFT AND LAKE
INDUCED CAPE VALUES CLIMB OVER 700J/KG AS H85 TEMPS FALL TO -17C TO
-20C BY TUESDAY NIGHT. SOUNDINGS ALSO INDICATE INCREASING MOISTURE
QUALITY TUESDAY INTO MOST OF TUESDAY NIGHT. SO...INSTABILITY AND
MOISTURE NOT THE ISSUE FOR MODERATE TO HEAVY SNOW. BOTH PARAMETERS
ARE THERE NO DOUBT. MAIN STICKING POINT FOR THE FORECAST ARE
LOW-LEVEL WIND FIELDS AND MORE SPECIFICALLY THE WIND DIRECTION WHICH
IS ALL SO CRITICAL FOR PEGGING WHERE HEAVIEST LK EFFECT WILL OCCUR.
UNFORTUNATELY...NOTEABLE DIFFERENCES EXIST BTWN THE NAM/NCEP HIGH
RES RUNS AND THE COARSER ECMWF/GFS AND ALSO THE GEM. MAIN ISSUE IS
HOW QUICKLY SOUTH TO BRING LOW-LEVEL WIND SHIFT PASSAGE ON TUESDAY.
PASSAGE OF THE TROUGH ESSENTIALLY KICKS LK EFFECT FM WNW/NW FLOW
AREAS TO AREAS FAVORED BY N/NNE WINDS. USUALLY LIKE THE NAM WITH
HIGHER RESOLUTION DETAILS...BUT SUCH A QUICK TROUGH PASSAGE AT
15Z-18Z ON TUESDAY IN THE NORTH SEEMS QUESTIONABLE AS SHORTWAVE
TROUGH AXIS IS STILL OVER CNTRL UPR MICHIGAN AT 18Z. WOULD EXPECT
THE TROUGH PASSAGE TO OCCUR TUESDAY EVENING IN THE WAKE OF THE
SHORTWAVE TROUGH CROSSING THE AREA. OVERALL...PREFERRED SOLUTION
IS PROBABLY MOST CLOSEST TO GFS/LOCAL REGIONAL WRF AND ECMWF.
WHAT THIS MEANS IN TERMS OF LK EFFECT SNOW IS EXPECT A PROLONGED
PERIOD OF LK EFFECT FOR WNW/NW FLOW AREAS LATE TONIGHT THROUGH LATE
TUESDAY AFTN /WHITE PINE TO ROCKLAND/TWIN LAKES AND MAYBE AS FAR
NORTH AS HOUGHTON/ AND ALSO OVER NORTHERN PARTS OF ALGER AND LUCE
COUNTIES. HEAVIER LK EFFECT THEN SHIFTS TO GOGEBIC/WESTERN ONTONAGON
AND MARQUETTE COUNTIES BY TUESDAY EVENING. BASED ON EXPECTED SLR/S
NEARING 20:1 OR EVEN ABOVE 20:1 AND QPF WHICH WAS BLEND OF REGIONAL
WRF AND EVENTUALLY THE WETTER NAM DNG LATER TUESDAY...SEEMS LIKE A
SOLID ADVY EVENT IS IN STORE WITH SNOW AMOUNTS OF 4-6/5-8 INCHES IN
THE 12 HOUR PERIOD FOR TUESDAY AND AGAIN ON TUESDAY NIGHT...THOUGH
THE LOCATIONS OF HEAVIEST SNOW SHOULD SHIFT AROUND AS WINDS IN THE
LAKE CONVECTIVE LAYER SO SOME SHEAR AND DO NOT STAY LOCKED IN THE
SAME DIRECTION FOR VERY LONG PERIOD OF TIME. SOME LOCATIONS IN THE
FAR WESTERN CWA /VCNTY OF IWD TO BERGLAND AND WHITE PINE/ MAY COME
CLOSER TO WARNING CRITERIA TUESDAY AFTN INTO TUESDAY NIGHT BUT SINCE
THE LARGER SCALE FORCING IS DIMINISHING WHEN WIND DIRECTION BECOMES
A MORE FAVORABLE N-NNE TO INCREASE CONVERGENCE IN THESE AREAS...WILL
OPT TO ISSUE THE ADVY AND LET FUTURE SHIFTS UPGRADE TO WARNING IF IT
IS NEEDED. SNOW WILL BE THE MAIN ISSUE WITH THIS EVENT. WINDS WILL
BE GUSTY 25-35 MPH...BUT STRONGEST WINDS AND BLSN/VSBY IMPACTS WILL
BE MORE OVER THE NORTHERN PARTS OF THE KEWEENAW ON TUESDAY AND
PERHAPS INTO NCNTRL UPR MICHIGAN ON TUESDAY NIGHT. NOT EXPECTING
WIDESPREAD BLSN AS THE EVENT THIS LAST WEEKEND HAD.
FOR NOW...COORDINATED WITH SHORT TERM FORECASTER AND PUT OUT LAKE
EFFECT SNOW ADVISORIES FOR WESTERN TIER. ADDITIONAL HEADLINES WILL
LIKELY BE ISSUED OVER NCNTRL AND POSSIBLY NORTHEAST CWA LATER TODAY
OR TONIGHT...BUT SINCE THE MORE SIGNIFICANT SNOW WILL NOT OCCUR IN
THESE AREAS UNTIL LATER TUESDAY OR EVEN AS LATE AS TUESDAY NIGHT IF
GFS IS COMPLETELY CORRECT...WILL NOT ISSUE THOSE HEADLINES NOW. NOT
ENOUGH CONFIDENCE THAT THESE AREAS WOULD SEE WARNING AMOUNTS SO DID
NOT WANT TO PUT A WATCH OUT EITHER.
SNOW SHOWERS PERSIST FOR N FLOW AREAS ON WEDNESDAY...BUT INTENSITY
WILL BE ON THE WANE WITH LOWERING INVERSION HEIGHTS TO AT OR BLO
5KFT. EVEN AS SNOW DIMINISHES...THE DGZ WILL BE IN THE HEART OF THE
LAKE CONVECTIVE LAYER SO WHAT SNOW SHOWERS ARE LEFTOVER ON WEDNESDAY
WILL BE THE EFFECIENT FLUFFY TYPE. WINDS WILL BE ON THE DECREASE AS
WELL...AS WILL BLSN/ASSOCIATED VSBY ISSUES. SINCE THE FLOW REMAINS
LGT NORTH ALL DAY AND INSTABILITY IS MORE THAN SUFFICIENT...SNOW
SHOWERS PROBABLY WILL NOT END COMPLETELY FOR FAR WEST OR NCNTRL BUT
THEY MAY BECOME PINNED CLOSER TO THE SHORELINES ON WEDNESDAY NIGHT
AS MESOSCALE EFFECTS/LAND BREEZES START TO DRIVE THE LOW-LEVEL
CONVERGENCE.
STILL COULD SEE SOME LGT SNOW ON THANKSGIVING. NO BIG IMPACT TO
TRAVEL EXPECTED THOUGH. BEST CHANCE OVER THE NORTHERN TIER. WEAK
TROUGH WORKS THROUGH THURSDAY NIGHT INTO FRIDAY. COULD SEE SOME SNOW
SHOWERS ACROSS KEWEENAW IN WNW FLOW ON FRIDAY. WEEKEND WILL FEATURE
MODEST WARMING TREND WITH SOME AREAS SLIGHTLY ABOVE FREEZING FOR
DAYTIME HIGHS. LGT SNOW MAY ACCOMPANY THIS WARM AIR ADVECTION BUT
LOOKS LIKE BETTER CHANCE FOR ANY SNOW ACCUMULATION WILL REMAIN TO
NORTH OF CWA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 628 PM EST SUN NOV 24 2013
A GUSTY SW WIND APRCHG 30 KTS AT IWD WL ADVECT LLVL DRY AIR INTO UPR
MI INTO THE EARLY MRNG HRS ON MON...SO EXPECT VFR CONDITIONS DESPITE
QUITE A BIT OF MID CLD COVER. BUT AS A STRONG DISTURBANCE NOW NEAR
LK WINNIPEG AND ITS ATTENDANT SFC COLD FNT DIG SEWD TOWARD THE UPR
LKS...EXPECT MVFR CONDITIONS TO DVLP OVER THE W AT IWD AND CMX BY
SUNRISE. WITH A STRONG UPSLOPE W WIND...THE FROPA WL BRING IFR
CONDITIONS FOR A COUPLE HRS AT CMX DURING THE MRNG. ALTHOUGH SOME
MVFR CIGS MAY OCCUR AT SAW WITH THE FROPA...DOWNSLOPE NATURE OF THE
FLOW INDICATES THIS CONDITION WL BE MARGINAL. THE BEST CHC OF MORE
PERSISTENT MVFR WX ON MON WL BE AT CMX WITH A MORE PRONOUNCED
UPSLOPE W WIND...WHICH WL GUST AS HI AS 30 KTS AT THIS EXPOSED
LOCATION WITH A SLOW INFLUX OF COLDER AIR/DESTABILIZATION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 252 PM EST SUN NOV 24 2013
SW GALES EXPECTED OVER NORTH CENTRAL LAKE SUPERIOR AND THE NORTHERN
LAKE MICHIGAN ZONES TONIGHT INTO MON MORNING AND WILL CONTINUE THE
GALE WARNING IN LAKE SUPERIOR DUE TO CHANNELED FLOW BETWEEN THE
KEWEENAW AND ISLE ROYALE. WINDS TURN TO NORTHWEST ON MONDAY INTO
TUESDAY AND REMAIN UP TO 30 KTS. GETS CLOSE TO GALES ON LAKE
SUPERIOR AGAIN TUE NIGHT INTO WED AND WILL HAVE TO WATCH THIS EVENT
FOR NOW. WINDS THEN STAY BELOW 20 KNOTS FOR THE REST OF THE FORECAST
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR MIZ001-003.
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ013-014.
LAKE EFFECT SNOW ADVISORY FROM 10 PM EST /9 PM CST/ THIS EVENING
TO NOON EST /11 AM CST/ WEDNESDAY FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING UNTIL NOON EST TODAY FOR LMZ248-250.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ221.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...KC
MARINE...07
AREA FORECAST DISCUSSION
NWS GAYLORD MI
450 AM EST MON NOV 25 2013
.SYNOPSIS...
ISSUED AT 449 AM EST MON NOV 25 2013
WINTRY CONDITIONS WILL BE PREVALENT ACROSS NORTHERN MICHIGAN THROUGH
THE THANKSGIVING HOLIDAY WEEK...WITH SEVERAL WEAKER WEATHER SYSTEMS
DELIVERING REPEATED SHOTS OF BOTH SYSTEM AND LAKE EFFECT SNOW. THE
FIRST WILL ARRIVE THIS MORNING...AS LOW PRESSURE TRACKS NEAR JAMES
BAY...BRINGING A ROUND OF SNOW TO MUCH OF NORTHWEST LOWER AND
EASTERN UPPER. A COLD FRONT WILL GRADUALLY WORK THROUGH THE REGION
LATER TUESDAY...BRINGING RENEWED COLD CONDITIONS ALONG WITH MORE
LAKE EFFECT SNOW. THAT GENERAL TREND WILL CONTINUE INTO THANKSGIVING
DAY...BEFORE QUIET WEATHER MAKES A RETURN TOWARD NEXT WEEKEND.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 449 AM EST MON NOV 25 2013
WELL...THAT WAS A NICE 12-ISH HOUR RESPITE FROM THE ACTIVE WEATHER.
NOW IT`S GAME ON ONCE AGAIN...WITH THE MAIN FORECAST ISSUES BEING OF
THE LAKE EFFECT/ENHANCEMENT VARIETY...ALONG WITH WIND ISSUES THROUGH
THE DAY TODAY. EARLY MORNING ANALYSIS PLACES VERY WEAK SHORTWAVE
RIDGE AXIS JUST TO THE EAST OF NORTHERN MICHIGAN...WITH DEEP AND
QUITE STRONG SOUTHWESTERLY FLOW WELL RAMPED UP ACROSS THE NORTHERN
LAKES IN ADVANCE OF ANOTHER STRONG UPPER WAVE QUICKLY AMPLIFYING
THROUGH SOUTHERN MANITOBA. INITIAL PUSH OF THAT WARM ADVECTION
EARLIER LED TO A BRIEF AXIS OF LIGHT SNOW MARCHING THROUGH
NORTHERN/EASTERN AREAS...WITH SECONDARY SURGE OF MUCH DEEPER AND
STRONGER ASCENT GOING INTO GRADUAL TOP-DOWN SATURATION OFF TO OUR
WEST AT THE MOMENT...AS EVIDENCED BY CEILINGS FALLING 5-8KFT OVER
THE PAST FEW HOURS. MEANWHILE...QUITE THE WINDY CONDITIONS HAVE
SHOWN UP RECENTLY AS CORE OF RATHER IMPRESSIVE 45-55 KNOT FLOW IS
ROLLING OVERHEAD...COMBINING WITH A REMNANT UNSTABLE AIRMASS ACROSS
THE LAKES TO PRODUCE SOME RATHER BEEFY WIND GUSTS PUSHING 50 MPH
ALONG THE LAKE MICHIGAN SHORE.
THE ABOVE MENTIONED WARM ADVECTION WILL BE IMPORTANT FOR OUR AREA
THIS MORNING...AS THE ADDED MOISTURE (FROM AN INITIALLY QUITE DRY
AIRMASS) GIVES A BIG BOOST OVER LAKE MICHIGAN. ALREADY SEEING THE
FIRST HINTS OF THIS RIGHT NOW...BUT THE THOUGHT IS THAT DEEPER
MOISTURE OVERRIDING THE LAKE WILL GO INTO THE RAPID PRODUCTION OF A
SOUTHWEST FLOW LAKE BAND THE NEXT FEW HOURS...WHICH WILL ULTIMATELY
GET PUNTED ONSHORE AS THE SHARP UPPER WAVE OVER MANITOBA WORKS
TOWARD OUR AREA. THESE TYPES OF SETUPS ALWAYS HAVE TROUBLE WRITTEN
ALL OVER THEM FROM AN IMPACT STANDPOINT...AS THERE SHOULD BE A
COUPLE HOUR WINDOW FOR SOME HEAVY SNOW TO FALL UP AND DOWN THE LAKE
MICHIGAN SHORELINE COUNTIES...AND PROBABLY EVEN FARTHER INLAND INTO
THE HIGHER TERRAIN WHERE UPSLOPE TYPICALLY WORKS ITS MAGIC IN SUCH A
SETUP. GIVEN WARMING THERMAL PROFILES...SNOW TO LIQUID RATIOS SHOULD
BE RATHER LOW...AS EVIDENCED BY A QUITE DEEP ISOTHERMAL LAYER AROUND
-6C PER FORECAST RAOBS...MAKING FOR MORE OF A GREASY/SLIPPERY SNOW.
THROW IN SOME QUITE GUSTY WINDS AND THE STAGE IS PROBABLY SET FOR A
PERIOD OF SLOPPY TRAVEL/LOW VSBYS ACROSS PRIMARILY NORTHWEST
LOWER...WITH A QUICK 2-3" OF SNOW EXPECTED TO FALL. LOCAL 4/12KM APX
WRF AND RECENT HRRR RUNS ARE EVEN MORE IMPRESSIVE...PAINTING AN AXIS
OF 0.4" OF LIQUID UP TOWARD CHARLEVOIX/EMMET/CHEBOYGAN/OTSEGO/ANTRIM
COUNTIES...WITH A SECONDARY MAXIMUM NEAR CADILLAC. GIVEN THE
EXPECTED LOWER RATIOS...SHOULDN`T SEE ACCUMULATION GET OUT OF
HAND...EVEN IF THE HIGHER QPF FORECASTS VERIFY. NOT SURE THIS WILL
BE WORTHY OF A WINTER WEATHER HEADLINE - PROBABLY MORE LIKE AN
SPS...ESPECIALLY CONSIDERING THE WORST CONDITIONS SHOULD OCCUR JUST
AFTER THE MORNING COMMUTE (MAINLY 9AM-1PM).
WINDS WILL SUBSIDE HEADING INTO THE AFTERNOON AS THE CORE OF
STRONGEST 950-900MB FLOW EXITS EAST...ALL WHILE DEEPER MOISTURE ALSO
STRIPS OUT. THAT LEAVES US IN MORE OF A LIGHT SNOW SHOWERS/SNIZZLE
REGIME FOR MUCH OF THE AFTERNOON AS SOUTHWEST FLOW CONTINUES BUT
WHILE CLOUD TOP TEMPS HOVER ONLY AROUND -8C. PROBABLY NOT LOOKING AT
MUCH ADDITIONAL ACCUMULATION FOR MOST AREAS THROUGH LATE AFTERNOON.
HOWEVER...MORE ISSUES SHOW UP BY EARLY EVENING WITH PERSISTENT HINTS
OF A STRONGER FRONTAL SNOW BAND BEING BROUGHT ASHORE INTO EASTERN
UPPER AS LOW PRESSURE NEARS THE SOUTHERN TIP OF JAMES BAY AND SWINGS
A COLD FRONT THROUGH THE EASTERN U.P. THAT FEATURE WILL IN ALL
LIKELIHOOD BECOME ABSORBED INTO THE LAKE AGGREGATE TROUGH OVER
EASTERN LAKE SUPERIOR...WITH PERHAPS EVEN A WEAK CIRCULATION CENTER
DEVELOPING IN RESPONSE TO YET ANOTHER STRONG UPPER WAVE ENTERING THE
ARROWHEAD OF MINNESOTA. THAT SETUP COULD LEAD TO ALL KINDS OF
MESOSCALE GARBAGE...BUT THE CLEAR SIGNAL IS FOR AN ENHANCED
CONVERGENCE BAND TO SKIRT FAR NORTHERN CHIPPEWA COUNTY...MAINLY
TOWARD PARADISE/WHITEFISH POINT...WITH MAYBE A COUPLE INCHES
POSSIBLE. FARTHER SOUTH...LOOKING LIKE PERSISTENT MORE NEBULOUS SNOW
SHOWERS WILL CONTINUE OVERNIGHT FOR SOUTHWEST FLOW AREAS ACROSS
NORTHWEST LOWER UP TOWARD DRUMMOND ISLAND. WAS A LITTLE CONCERNED
ABOUT SOME DRIZZLE POSSIBILITIES GIVEN INITIALLY SHALLOW NATURE OF
MOISTURE...BUT GRADUAL INTRUSION OF COLDER AIR ALOFT SHOULD FAVOR
ICE IN THE CLOUDS AS CLOUD TOP TEMPS END UP AROUND -12C BY 06Z. NO
MAJOR ACCUMULATION FORESEEN FOR NORTHERN LOWER OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 449 AM EST MON NOV 25 2013
A VERY ACTIVE AND RAPIDLY CHANGING WEATHER PATTERN WILL REMAIN
LOCKED IN ACROSS THE GREAT LAKES THROUGH THE THANKSGIVING HOLIDAY
WITH A SERIES OF SHORTWAVES AND SHOTS OF COLDER CANADIAN AIR
RESULTING IN A COUPLE OF ROUNDS OF LAKE EFFECT AND LAKE ENHANCED
SNOWFALL. THIS WILL ALSO PREVENT US FROM ANY SIGNIFICANT WARMING FOR
THE NEXT SEVERAL DAYS. A FAIRLY QUIET PERIOD OF WEATHER IS THEN
ANTICIPATED FOR FRIDAY THROUGH THE WEEKEND.
TUESDAY THROUGH WEDNESDAY NIGHT...A SIMILAR SET UP LIKE TODAY...IS
EXPECTED FOR TUESDAY WITH NEXT VIGOROUS SHORTWAVE...COLD FRONT AND
DEEPER MOISTURE ANTICIPATED TO MOVE IN ACROSS NRN MICHIGAN. THIS
TIME AROUND...WE WILL HAVE A BIT DEEPER INSTABILITY BUT LESS WIND.
WEST/WSW FLOW AHEAD OF THIS FRONT...H8 TEMPS COLDER IN THE -10C TO
-11C RANGE AND INVERSION HEIGHTS TO 7KFT WILL INCREASE TO NEAR 9KFT
WITH COLD ADVECTION THROUGH THE DAY...BUT A DRAMATIC SHIFT IN WINDS
TO OUT OF THE NNW INTO TUESDAY EVENING. MOISTURE IN THE LOWEST
LEVELS ARE STARTING TO LOOK A BIT MORE MOISTURE...MORE SO ON THIS
RUN OF THE BUFR SOUNDINGS. THE MOST IMPRESSIVE LES PARAMETERS ARE
REALLY FOCUSED TUESDAY EVENING AFTER THE FLOW TURNS NORTHERLY WITH
DEEPEST INSTABILITY WITH PASSAGE OF UPPER TROUGH AXIS/COLD AIR
ALOFT. THIS WILL FOCUS THE BEST ACCUMULATION POTENTIAL ACROSS THE
GTV BAY REGION AND AREAS SOUTH...WHERE ALSO...GUSTY WINDS COULD
LEAD TO BLOWING AND DRIFTING ISSUES. A CONSERVATIVE 3-6 INCHES OF
SNOW WILL BE POSSIBLE IN THIS REGION TUESDAY-TUESDAY NIGHT...LEADING
TO THE MOST HAZARDOUS DRIVING CONDITIONS EXPECTED IN THE LONG TERM
PORTION OF THE FORECAST. THE AIR MASS DRIES WITH LOWERING INVERSION
HEIGHTS INTO WEDNESDAY...HOWEVER CONTINUED COLD ADVECTION AND BEST
FETCH INTO GTV BAY WILL LEAD TO ANOTHER 1-2 INCHES OF SNOW
THERE...WHILE AMOUNTS ARE LESS IMPRESSIVE ELSEWHERE. FAR NE LOWER
NEAR ROGERS CITY/ALPENA AND OSCODA WILL SEE A SMATTERING OF 1 TO
MAYBE 3 INCH LOCAL AMOUNTS TUESDAY NIGHT INTO WEDNESDAY. WEDNESDAY
NIGHT...INVADING HIGHER PRESSURE AND LIGHTER WINDS FOR A LESSER
THREAT TO ANYTHING SIGNIFICANT IN THE SNOW DEPARTMENT.
HOWEVER...WILL HAVE TO KEEP AN EYE ON NEXT INCOMING SHORTWAVE AND
WARM ADVECTION OVER THE TOP OF THE REMAINING INSTABILITY...ALTHOUGH
MOST AREAS...LOOK TO HAVE A DISCONNECT FROM THE MOISTURE AND
ENHANCEMENT SEEDED FROM ALOFT. SLOWLY BACKING LOW LEVEL WINDS WILL
FOCUS ANY EMERGING THREAT OF RENEWED SNOW IN AND AROUND LAKE
MICHIGAN.
THANKSGIVING DAY AND NIGHT...THIS INCOMING WAVE IS RATHER WEAK
COMPARED TO IT`S PREDECESSORS....ALTHOUGH THE WARM ADVECTION/SEEDING
ALOFT DOES LOOK TO STILL HAVE SOME SORT OF ENHANCEMENT TO THE LAKE
EFFECT THROUGH THE HOLIDAY AND THURSDAY NIGHT. WINDS ARE EXPECTED TO
BE FAIRLY LIGHT...AND NOW SHIFTING ALL AROUND TO THE SW AS THIS
ENHANCEMENT PROCESS IN UNDERWAY...SPREADING SNOWS AROUND LAKE
MICHIGAN WITH LESS INLAND PENETRATION. THESE FINER DETAILS WILL
REALLY HAVE TO BE EXAMINED FURTHER OVER THE NEXT COUPLE OF DAYS TO
PROVIDE A MORE DETAILED HOLIDAY FORECAST. WIND DIRECTIONS AND SPEEDS
BEING THE MOST CRUCIAL...WHICH HAS A BIT OF UNCERTAINTY.
FRIDAY THROUGH SUNDAY...THIS WEAKER WAVE EXITS FRIDAY WITH SHALLOW
MID LEVEL RIDGING...AHEAD OF NEXT ADVERTISED SHORTWAVE ARRIVING
SATURDAY. A WEAK COLD FRONT LAYS ACROSS/WASHES OUT OVER NRN
MICHIGAN. COULD BE ONE LAST HOORAH OF SOME WEAKER LAKE EFFECT...BUT
THIS APPEARS TO BE THE LEAST OF CONCERN IN THE SERIES OF LAKE EFFECT
EVENTS. THIS MAINLY DUE TO THE CONTINUED LOW LEVEL WARM ADVECTION
AND GRADUAL EROSION OF THE OVERLAKE INSTABILITY. WILL HAVE RATHER
SMALL CHANCES FOR SNOW IN AND AROUND LAKE MICHIGAN IN THE SW FLOW
THAT PERSISTS INTO SUNDAY. TEMPERATURES WILL MODERATE BACK INTO THE
LOWER HALF OF THE 30S OVER THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1159 PM EST SUN NOV 24 2013
MAINLY VFR UNTIL MONDAY MORNING...THOUGH WITH LLWS AND/OR GUSTY
SW WINDS. CIGS/VSBY RESTRICTIONS ARRIVE IN -SHSN FROM NORTH TO
SOUTH MONDAY MORNING.
LOW PRESSURE NOW ALONG MANITOBA/ONTARIO BORDER WILL PASS JUST NORTH OF
SUPERIOR ON MONDAY. SW WINDS ARE INCREASING JUST OFF THE DECK
AHEAD OF THE LOW...RESULTING IN LLWS AT ALL TAF SITES
OVERNIGHT (GIVING WAY TO GUSTY SW WINDS BEFORE DAWN PLN/MBL).
SNOW WILL RE-DEVELOP MONDAY MORNING...1ST AT PLN...EVENTUALLY
IMPACTING ALL TAF SITES. MVFR TO IFR CONDITIONS EXPECTED AT TIMES
IN SHSN/BLSN...THOUGH WITH CONSIDERABLE VARIABILITY.
GUSTY SW WINDS ALL DAY MONDAY...LIGHTENING UP AND VEERING A BIT TO
THE WEST TOWARD EVENING.
&&
.MARINE...
ISSUED AT 449 AM EST MON NOV 25 2013
A WINDY ONE OUT THERE TO START...WITH GALES FOR MOST OF THE WATERS.
THOSE WINDS WILL SUBSIDE LATER THIS AFTERNOON AND ESPECIALLY THIS
EVENING...THOUGH WILL REMAIN A BIT GUSTY IN THE 20-25 KNOT RANGE AS
IS TYPICAL FOR LATE NOVEMBER. WINDS WILL GRADUALLY COME AROUND TO
THE NORTHWEST ON TUESDAY AND THEN NORTH TUESDAY NIGHT AND
WEDNESDAY...WITH CONTINUED GUSTS OF 25-30 KNOTS EXPECTED. COULD SEE
A PERIOD OF GALES ON MAINLY LAKE MICHIGAN SOMETIME TUESDAY NIGHT...
BUT CONFIDENCE IN THAT IS LOW AT THIS TIME. HIGH PRESSURE WILL
FINALLY WIN THE BATTLE BY THURSDAY...WITH A RETURN TO A BRIEF PERIOD
OF MUCH LIGHTER WINDS OF THE 15 KNOTS OF LESS VARIETY.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ015-016-019-
020-025-031.
LH...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LHZ345>349.
LM...GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ323-341-342-
344>346.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR LSZ321-322.
&&
$$
SYNOPSIS...DL
SHORT TERM...DL
LONG TERM...SD
AVIATION...JZ
MARINE...DL
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1145 AM CST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CST MON NOV 25 2013
A WEAK COLD FRONT CURRENTLY MOVING THROUGH SRN SOUTH DAKOTA
SHOULD CLEAR THE FORECAST AREA BY 21Z. A STRONG THERMAL RIDGE IS
RUNNING OUT AHEAD OF THE COLD FRONT WITH SFC TEMPS RISING INTO THE
UPPER 30S. THIS SHOULD MIX OUT THE ATMOSPHERE AND GIVE A HEAD
START TO MAX TEMPS IN THE 40S. THIS IS CLOSE TO THE RAP MODEL
WHICH WAS THE WARMEST SOLN NEXT TO THE ECM GUIDANCE FORECASTING
HIGHS IN THE MID AND UPPER 40S. SOME MID LEVEL CLOUDINESS
ASSOCIATED WITH THE COLD FRONT WOULD SUGGEST USING A FCST SLIGHTLY
COOLER THAN THE VERY WARM ECM GUIDANCE.
FOR TONIGHT...A REINFORCING ARCTIC FRONT...CURRENTLY ACROSS NRN
SASKATCHEWAN WILL BE MOVING THROUGH SD WITH A WEAK THERMAL RIDGE
RUNNING OUT AHEAD OF THIS FRONT. THE MODEL CONSENSUS SUGGESTED LOWS
IN THE TEENS WHICH MIGHT BE TOO COLD. THE MODELS APPEAR TO BE
PUSHING THIS FRONT INTO THE FCST AREA AROUND 06Z TONIGHT WITH H850
MB WINDS INCREASING TO 35 TO 40 KT WHICH WOULD SUPPORT MIXING
AND WARMER LOWS.
NO STRATUS IS EXPECTED WITH EITHER FRONT TODAY OR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM CST MON NOV 25 2013
THE SOUTHERN PLAINS UPPER LEVEL LOW WILL PHASE TUESDAY WITH A
STRONG SHORTWAVE DROPPING SOUTHEAST THROUGH CANADA INTO THE GREAT
LAKES REGION. THIS WILL BRING HEAVY PRECIPITATION TO THE EAST
COAST WEDNESDAY. ACROSS OUR AREA...ANOTHER SHOT OF ARCTIC AIR
WILL PLUMMET SOUTH TUESDAY ON THE BACK SIDE OF THE DEVELOPING
EASTERN CONUS STORM. THIS WILL KEEP HIGHS IN THE 20S ONCE AGAIN
ACROSS PORTIONS OF NORTHERN NEBRASKA...WITH LOWER TO MID 30S
ACROSS THE PANHANDLE INTO SOUTHWEST NEBRASKA. THIS COLD AIR WILL
BE SHORT LIVED...AS UPPER LEVEL RIDGING AND A PACIFIC AIRMASS
SPREAD EAST THROUGH THE PLAINS STARTING WEDNESDAY. THE ECMWF HAS
BEEN ADVERTISING A CHINOOK EVENT WEDNESDAY...AND THIS SHOULD HELP
SCOUR OUT THE ARCTIC AIR. SHOULD SEE HIGHS INTO THE 40S ACROSS
WESTERN NEBRASKA...WITH LOWER 30S FARTHER EAST WHERE THE ARCTIC
AIR WILL BE MORE DENSE AND TAKE LONGER TO MIX OUT.
THE UPPER RIDGE BECOMES DOMINATE THANKSGIVING AND FRIDAY...WITH
DRY AND MILD CONDITIONS AREA WIDE. BY THE WEEKEND...THE UPPER
RIDGE WILL BEGIN TO FLATTEN...BUT IT REMAINS MILD AND DRY. MORE
COLD ARCTIC AIR IS POSSIBLE BEYOND THE FORECAST PERIOD AS WE HEAD
INTO NEXT WEEK...AS LARGE GULF OF ALASKA UPPER LEVEL LOW COULD
DROP SOUTHEAST INTO THE PACIFIC NORTHWEST. STAY TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1144 AM CST MON NOV 25 2013
VFR CONDITIONS ARE EXPECTED TO PREVAIL FOR THE NEXT 24 HOURS
ACROSS WESTERN AND NORTH CENTRAL NEBRASKA. WINDS REMAIN OUT OF THE
NORTHWEST THROUGH 18Z TUESDAY. SCT TO BKN CLOUD DECK WILL HAVE
CIGS WELL ABOVE IFR LEVELS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
522 AM CST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CST MON NOV 25 2013
A WEAK COLD FRONT CURRENTLY MOVING THROUGH SRN SOUTH DAKOTA
SHOULD CLEAR THE FORECAST AREA BY 21Z. A STRONG THERMAL RIDGE IS
RUNNING OUT AHEAD OF THE COLD FRONT WITH SFC TEMPS RISING INTO THE
UPPER 30S. THIS SHOULD MIX OUT THE ATMOSPHERE AND GIVE A HEAD
START TO MAX TEMPS IN THE 40S. THIS IS CLOSE TO THE RAP MODEL
WHICH WAS THE WARMEST SOLN NEXT TO THE ECM GUIDANCE FORECASTING
HIGHS IN THE MID AND UPPER 40S. SOME MID LEVEL CLOUDINESS
ASSOCIATED WITH THE COLD FRONT WOULD SUGGEST USING A FCST SLIGHTLY
COOLER THAN THE VERY WARM ECM GUIDANCE.
FOR TONIGHT...A REINFORCING ARCTIC FRONT...CURRENTLY ACROSS NRN
SASKATCHEWAN WILL BE MOVING THROUGH SD WITH A WEAK THERMAL RIDGE
RUNNING OUT AHEAD OF THIS FRONT. THE MODEL CONSENSUS SUGGESTED LOWS
IN THE TEENS WHICH MIGHT BE TOO COLD. THE MODELS APPEAR TO BE
PUSHING THIS FRONT INTO THE FCST AREA AROUND 06Z TONIGHT WITH H850
MB WINDS INCREASING TO 35 TO 40 KT WHICH WOULD SUPPORT MIXING
AND WARMER LOWS.
NO STRATUS IS EXPECTED WITH EITHER FRONT TODAY OR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM CST MON NOV 25 2013
THE SOUTHERN PLAINS UPPER LEVEL LOW WILL PHASE TUESDAY WITH A
STRONG SHORTWAVE DROPPING SOUTHEAST THROUGH CANADA INTO THE GREAT
LAKES REGION. THIS WILL BRING HEAVY PRECIPITATION TO THE EAST
COAST WEDNESDAY. ACROSS OUR AREA...ANOTHER SHOT OF ARCTIC AIR
WILL PLUMMET SOUTH TUESDAY ON THE BACK SIDE OF THE DEVELOPING
EASTERN CONUS STORM. THIS WILL KEEP HIGHS IN THE 20S ONCE AGAIN
ACROSS PORTIONS OF NORTHERN NEBRASKA...WITH LOWER TO MID 30S
ACROSS THE PANHANDLE INTO SOUTHWEST NEBRASKA. THIS COLD AIR WILL
BE SHORT LIVED...AS UPPER LEVEL RIDGING AND A PACIFIC AIRMASS
SPREAD EAST THROUGH THE PLAINS STARTING WEDNESDAY. THE ECMWF HAS
BEEN ADVERTISING A CHINOOK EVENT WEDNESDAY...AND THIS SHOULD HELP
SCOUR OUT THE ARCTIC AIR. SHOULD SEE HIGHS INTO THE 40S ACROSS
WESTERN NEBRASKA...WITH LOWER 30S FARTHER EAST WHERE THE ARCTIC
AIR WILL BE MORE DENSE AND TAKE LONGER TO MIX OUT.
THE UPPER RIDGE BECOMES DOMINATE THANKSGIVING AND FRIDAY...WITH
DRY AND MILD CONDITIONS AREA WIDE. BY THE WEEKEND...THE UPPER
RIDGE WILL BEGIN TO FLATTEN...BUT IT REMAINS MILD AND DRY. MORE
COLD ARCTIC AIR IS POSSIBLE BEYOND THE FORECAST PERIOD AS WE HEAD
INTO NEXT WEEK...AS LARGE GULF OF ALASKA UPPER LEVEL LOW COULD
DROP SOUTHEAST INTO THE PACIFIC NORTHWEST. STAY TUNED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 522 AM CST MON NOV 25 2013
VFR IS EXPECTED TODAY AND TONIGHT. IFR/MVFR ACROSS SCNTL NEB WILL
MOVE EAST THIS MORNING...AWAY FROM THE FCST AREA. A WEAK COLD
FRONT WILL MOVE THROUGH THE FCST AREA THIS MORNING FOLLOWED BY A
SECOND STRONGER FRONT LATE TONIGHT. VFR CIGS ARE EXPECTED TO
PREVAIL WITH BOTH FRONTAL PASSAGES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
345 AM CST MON NOV 25 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CST MON NOV 25 2013
A WEAK COLD FRONT CURRENTLY MOVING THROUGH SRN SOUTH DAKOTA
SHOULD CLEAR THE FORECAST AREA BY 21Z. A STRONG THERMAL RIDGE IS
RUNNING OUT AHEAD OF THE COLD FRONT WITH SFC TEMPS RISING INTO THE
UPPER 30S. THIS SHOULD MIX OUT THE ATMOSPHERE AND GIVE A HEAD
START TO MAX TEMPS IN THE 40S. THIS IS CLOSE TO THE RAP MODEL
WHICH WAS THE WARMEST SOLN NEXT TO THE ECM GUIDANCE FORECASTING
HIGHS IN THE MID AND UPPER 40S. SOME MID LEVEL CLOUDINESS
ASSOCIATED WITH THE COLD FRONT WOULD SUGGEST USING A FCST SLIGHTLY
COOLER THAN THE VERY WARM ECM GUIDANCE.
FOR TONIGHT...A REINFORCING ARCTIC FRONT...CURRENTLY ACROSS NRN
SASKATCHEWAN WILL BE MOVING THROUGH SD WITH A WEAK THERMAL RIDGE
RUNNING OUT AHEAD OF THIS FRONT. THE MODEL CONSENSUS SUGGESTED LOWS
IN THE TEENS WHICH MIGHT BE TOO COLD. THE MODELS APPEAR TO BE
PUSHING THIS FRONT INTO THE FCST AREA AROUND 06Z TONIGHT WITH H850
MB WINDS INCREASING TO 35 TO 40 KT WHICH WOULD SUPPORT MIXING
AND WARMER LOWS.
NO STRATUS IS EXPECTED WITH EITHER FRONT TODAY OR TONIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 327 AM CST MON NOV 25 2013
THE SOUTHERN PLAINS UPPER LEVEL LOW WILL PHASE TUESDAY WITH A
STRONG SHORTWAVE DROPPING SOUTHEAST THROUGH CANADA INTO THE GREAT
LAKES REGION. THIS WILL BRING HEAVY PRECIPITATION TO THE EAST
COAST WEDNESDAY. ACROSS OUR AREA...ANOTHER SHOT OF ARCTIC AIR
WILL PLUMMET SOUTH TUESDAY ON THE BACK SIDE OF THE DEVELOPING
EASTERN CONUS STORM. THIS WILL KEEP HIGHS IN THE 20S ONCE AGAIN
ACROSS PORTIONS OF NORTHERN NEBRASKA...WITH LOWER TO MID 30S
ACROSS THE PANHANDLE INTO SOUTHWEST NEBRASKA. THIS COLD AIR WILL
BE SHORT LIVED...AS UPPER LEVEL RIDGING AND A PACIFIC AIRMASS
SPREAD EAST THROUGH THE PLAINS STARTING WEDNESDAY. THE ECMWF HAS
BEEN ADVERTISING A CHINOOK EVENT WEDNESDAY...AND THIS SHOULD HELP
SCOUR OUT THE ARCTIC AIR. SHOULD SEE HIGHS INTO THE 40S ACROSS
WESTERN NEBRASKA...WITH LOWER 30S FARTHER EAST WHERE THE ARCTIC
AIR WILL BE MORE DENSE AND TAKE LONGER TO MIX OUT.
THE UPPER RIDGE BECOMES DOMINATE THANKSGIVING AND FRIDAY...WITH
DRY AND MILD CONDITIONS AREA WIDE. BY THE WEEKEND...THE UPPER
RIDGE WILL BEGIN TO FLATTEN...BUT IT REMAINS MILD AND DRY. MORE
COLD ARCTIC AIR IS POSSIBLE BEYOND THE FORECAST PERIOD AS WE HEAD
INTO NEXT WEEK...AS LARGE GULF OF ALASKA UPPER LEVEL LOW COULD
DROP SOUTHEAST INTO THE PACIFIC NORTHWEST. STAY TUNED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1130 PM CST SUN NOV 24 2013
OVER THE NEXT 24 HOURS...EXPECT SCATTERED HIGH CLOUDINESS ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA IN ASSOCIATION WITH AN UPPER
LEVEL TROUGH OF LOW PRESSURE TO THE NORTH AND A CLOSED LOW TO THE
SOUTH. CIGS WILL RANGE FROM 20000 TO 25000 FT AGL AT BOTH THE KVTN
AND KLBF TERMINALS. WINDS OVERNIGHT TONIGHT WILL BE FROM THE WEST OR
SOUTHWEST AT UNDER 10 KTS. WINDS WILL SHIFT TO THE NORTH MONDAY
MORNING INCREASING TO 10 TO 20 KTS MONDAY AFTERNOON...THEN
DECREASING TO UNDER 10 KTS MONDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...TAYLOR
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1130 PM CST SUN NOV 24 2013
.SYNOPSIS...
ISSUED AT 235 PM CST SUN NOV 24 2013
AN UPPER LOW SPUN OVER THE FOUR CORNERS ON SUNDAY AFTERNOON...WHICH
PUSHED SOME MID AND HIGH LEVEL CLOUDS INTO SOUTHERN NEBRASKA. WITH
THE UPPER LOW TO THE SOUTH...WESTERLY FLOW ALOFT HAS ALLOWED FOR A
THERMAL RIDGE TO MOVE INTO THE NORTHERN PLAINS TODAY WHERE 850MB
TEMPERATURES WERE GENERALLY 5C TO 10C AS OF 12Z THIS MORNING
COMPARED TO 0C TO-5C ACROSS NEBRASKA. LOOKING AT WATER VAPOR...COULD
MAKE OUT THE NEXT LOW PRESSURE SYSTEM IN LINE IN THE NORTHWEST FLOW
OVER SASKATCHEWAN...WITH ANOTHER BATCH OF COLD ARCTIC AIR BEHIND IT.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 235 PM CST SUN NOV 24 2013
THE UPPER LEVEL LOW OVER THE FOUR CORNERS IS EXPECTED TO START
GETTING INFLUENCED BY THE MEAN NORTHWEST FLOW AND START TO PUSH INTO
TEXAS BY THE END OF THE DAY MONDAY. THIS SHOULD ALLOW FOR THE MID
AND HIGH CLOUDS THAT HAVE BEEN SPINNING AROUND THIS SYSTEM INTO THE
SOUTHERN PART OF THE FORECAST AREA FOR THE PAST SEVERAL DAYS TO GET
PULLED SOUTHWARD AND AWAY FROM THE LOCAL AREA TONIGHT AND MONDAY
MORNING. IT WILL ALSO ALLOW FOR SOME OF THE COLDER AIR ASSOCIATED
WITH THAT SYSTEM TO GET PUSHED AWAY FROM THE AREA. MEANWHILE...THE
LOW PRESSURE SYSTEM OVER SASKATCHEWAN WILL MOVE INTO ONTARIO WHICH
WILL DRAG A COLD FRONT ACROSS NEBRASKA TONIGHT AND MONDAY MORNING.
ALTHOUGH TEMPERATURES BEHIND THE FRONT WON/T BE MUCH COLDER FOR THE
LOCAL AREA. WINDS WILL SWITCH TO THE NORTH-NORTHWEST BEHIND THE
FRONT. FORECAST SOUNDINGS ARE SHOWING MINIMAL MIXING MONDAY
AFTERNOON...BUT WINDS JUST ABOVE THE SURFACE ARE ABOUT 25KTS SO
COULD SEE SOME 20KT WINDS AT GROUND LEVEL DURING THE AFTERNOON.
ONE CONCERN WITH THE FORECAST WILL BE THE POTENTIAL FOR THE
DEVELOPMENT OF SHALLOW STRATUS THIS EVENING AND TONIGHT FROM
SOUTHWEST INTO CENTRAL NEBRASKA. LOW LEVEL MOISTURE ADVECTION IS
BEING INDICATED INTO THE AREA AHEAD OF THE FRONT BY SEVERAL FORECAST
MODELS...WITH THE NAM BEING THE MOST ROBUST SPREADING STRATUS ACROSS
THE ENTIRE FORECAST AREA. DISCOUNTING THAT MODEL AND LOOKING CLOSER
TO THE RAP WHICH HAS BEEN HOLDING OFF THE LOW LEVEL MOISTURE FROM
MOVING INTO NEBRASKA THROUGH THE DAY TODAY. ALTHOUGH IT HAS KEPT
THIS MOISTURE SOUTH TODAY...IT DOES CONTINUE TO PUSH IT INTO
NEBRASKA THIS EVENING...WITH CLOUDS REMAINING UNTIL THE FRONT PUSHES
THROUGH LATE TONIGHT AND MONDAY MORNING. WATCHING THE STRATUS
STRUGGLE TO DEVELOP IN UPSTREAM AREAS TODAY...AND WITH THE RAP
CONTINUOUSLY BACKING OFF ON THE TIMING OF BRINGING IT NORTH...JUST
DON/T HAVE THE CONFIDENCE THAT THE CLOUDS WILL GET INTO THE LOCAL
AREA TONIGHT AND THE FORECAST TAKES THAT INTO ACCOUNT. IF THE
STRATUS DOES MOVE IN...MAY HAVE TO TAKE A LOOK AT LOW TEMPERATURES
TONIGHT...ALTHOUGH THEY SHOULDN/T HAVE AN IMPACT ON HIGHS MONDAY AS
THEY WOULD BE PUSHED OUT OF THE AREA BEFORE PEAK HEATING.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SUN NOV 24 2013
A REINFORCING SHOT OF ARCTIC AIR WILL MOVE THROUGH THE DAKOTAS
INTO NEBRASKA MONDAY NIGHT AND TUESDAY. THIS WILL BRING A GLANCING
BLOW OF COLDER AIR...WHICH IS ACTUALLY NOT AS COLD AS THE PREVIOUS
ONE SATURDAY. WENT A FEW DEGREES ABOVE GUIDANCE LOWS MONDAY NIGHT
WITH MID/UPPER TEENS. WEAK COLD AIR ADVECTION TUESDAY WITH H85
TEMPS AS LOW AS -15C PER NAM MODEL. THIS LOOK TOO COLD AND FAVORED
THE GFS -11C. USING CONSALL INTO A BLEND HIGHS NEAR 25 AT ONL TO
36 AT IML. TEMPERATURES THEN WARMUP FOR WEDNESDAY. AS SURFACE HIGH
SLIDES EAST...A RETURN SOUTH TO SOUTHWEST FLOW DEVELOPS. WHILE
HIGHS TO BE LIMITED TO NEAR 30 AT BBW AND ONL...THE WESTERN TIER
OF COUNTIES TO WARM TO 40-43 DEGREES. DRY CONDITIONS TO ALSO PREVAIL.
FOR THANKSGIVING DAY THROUGH THE WEEKEND...DRY AND SEASONAL
TEMPERATURES ARE FORECAST. THE UPPER FLOW WILL REMAIN FAIRLY
ZONAL. THIS HIGHLIGHTED BY AN UPPER TROUGH DIGGING FROM BRITISH
COLUMBIA INTO THE NORTHERN PLAINS AND A CLOSED LOW REMAINING OFF
THE CALIF. COAST. ONLY A WEAK COLD FRONT INDICATED FRIDAY
NIGHT...WHICH SHOULD HAVE MINIMAL IMPACT TO HIGHS SATURDAY AND
SUNDAY. ONLY VERY MINOR CHANGES TO HIGHS THROUGH THIS WEEKEND WITH
MAINLY UPPER 30S TO MID 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1130 PM CST SUN NOV 24 2013
OVER THE NEXT 24 HOURS...EXPECT SCATTERED HIGH CLOUDINESS ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA IN ASSOCIATION WITH AN UPPER
LEVEL TROUGH OF LOW PRESSURE TO THE NORTH AND A CLOSED LOW TO THE
SOUTH. CIGS WILL RANGE FROM 20000 TO 25000 FT AGL AT BOTH THE KVTN
AND KLBF TERMINALS. WINDS OVERNIGHT TONIGHT WILL BE FROM THE WEST OR
SOUTHWEST AT UNDER 10 KTS. WINDS WILL SHIFT TO THE NORTH MONDAY
MORNING INCREASING TO 10 TO 20 KTS MONDAY AFTERNOON...THEN
DECREASING TO UNDER 10 KTS MONDAY EVENING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...ROBERG
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1001 PM EST TUE NOV 26 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 WEDNESDAY MORNING/...
AS OF 950 PM EST TUESDAY...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 WEDNESDAY 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 /03Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...SNOW HAS OVERSPREAD MOST OF FORECAST AREA
WITH VSBYS LOWERING QUICKLY TO IFR AND CIGS TO MVFR. WIDESPREAD
IFR WITH AREAS OF MVFR EXPECTED THROUGH THE PERIOD. SNOW WILL
TRANSITION TO RAIN OVERNIGHT AT ALL SITES EXCEPT KMSS AND KSLK.
LOOK FOR SNOW TO MIX WITH SLEET AND POSSIBLY FREEZING RAIN BY 02Z
AT KRUT...AND BETWEEN 04-06Z AT KMPV/KBTV/KPBG/KSLK. MIX WILL THEN
CHANGE TO RAIN AT KRUT BY 04Z AND BETWEEN 06Z-10Z AT KMPV/KBTV/KPBG.
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 00Z THURSDAY THROUGH SUNDAY...
00Z THURSDAY THROUGH 18Z THURSDAY...MVFR AND IFR CATEGORIES
CONTINUE INTO THANKSGIVING MORNING. ANY MIXED PRECIPITATION
CHANGES TO ALL SNOW WEDNESDAY EVENING AND THEN AND TAPERS TO SNOW
SHOWERS THURSDAY MORNING. CEILINGS AND VISIBILITIES WILL MOVE BACK
INTO THE MVFR AND VFR CATEGORIES BY 18Z THURSDAY AS SNOW SHOWERS
COME TO AN END.
18Z THURSDAY 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 FORCAST 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 258 PM EST TUESDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
THROUGH AT LEAST MIDNIGHT. WHILE WINDS HAVE DROPPED OFF A LITTLE BIT
FROM THIS MORNING...THEY ARE STILL HOVERING AROUND 25 KNOTS AT
COLCHESTER REEF THIS AFTERNOON. A SLIGHT LULL MAY OCCUR EARLY THIS
EVENING BEFORE WINDS PICK UP AGAIN THROUGH MIDNIGHT. AFTER MIDNIGHT
THOUGH...WINDS SHIFT TO THE NORTH BY WEDNESDAY MORNING AND DECREASE
BELOW ADVISORY LEVELS. THIS LULL WILL BE BRIEF THOUGH AS A COLD
FRONT PASSES THROUGH THE REGION WEDNESDAY EVENING...WINDS WILL
SHIFT TO THE NORTHWEST AND BECOME STRONG AGAIN AT 25-35 KNOTS...WITH
WAVES BUILDING TO 4 TO 6 FEET. ANOTHER ADVISORY WILL LIKELY BE
NEEDED IN THE FUTURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
VTZ001>012-016>019.
FLOOD WATCH FROM 7 AM EST WEDNESDAY THROUGH LATE WEDNESDAY
NIGHT 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 WEDNESDAY FOR NYZ028-
035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...MUCCILLI
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...RJS
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
706 PM EST TUE NOV 26 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 WEDNESDAY MORNING/...
AS OF 623 PM EST TUESDAY...GOING FORECAST REMAINS IN PRETTY GOOD
SHAPE. LIGHT SNOW HAS OVERSPREAD MUCH OF THE REGION THIS EVENING
AND WILL CONTINUE WORKING NORTHWARD AS LOW PRESSURE LOCATED IN THE
SOUTHEASTERN US MOVES NORTHEASTWARD. PRECIPITATION-TYPE REMAINS
THE MOST CHALLENGING ASPECT OF THIS SYSTEM. RAP 850/925 MB 0C
LINES DOING FAIRLY WELL SO FAR THIS EVENING DELINEATING BETWEEN
SNOW AND SLEET/FREEZING RAIN...THUS LEANED TOWARDS IT AND THE HRRR FOR
NEXT SEVERAL HOURS. CHANGEOVER AT RUTLAND AND PORTIONS OF SOUTHERN
VT TO MIXED PRECIP OR RAIN AROUND 02Z...AND MUCH OF THE REST OF THE
AREA EXCEPT THE SAINT LAWRENCE VALLEY 04-07Z. 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 THIRD 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.
PREVIOUS DISCUSSION FROM 315 PM TUESDAY...
FORECAST REMAINS MORE OR LESS ON TRACK AS WE HEAD INTO THE EVENING
AND OVERNIGHT HOURS AS LOW PRESSURE AND ASSOCIATED PRECIPITATION
ADVANCE STEADILY NORTHEAST INTO THE REGION. BOTH GLOBAL AND
MESOSCALE MODELS CONTINUE TO SHOW VERY GOOD AGREEMENT ON TRACK OF
SFC LOW AND DEPICTION/EVOLUTION OF THE MEAN 925/850/700 MB 0C LINE
ADVANCING NORTH/NORTHWESTWARD INTO THE AREA. THUS PRIOR IDEA OF A
WIDESPREAD WINTRY MIX OVERSPREADING OUR AREA STILL LOOKS RIGHT ON
TRACK. SOME LIGHT TO MODEST SNOW ACCUMULATIONS POSSIBLE DURING
THIS PERIOD...ESPECIALLY ACROSS OUR NRN NY COUNTIES WHICH WILL BE
DEEPER WITHIN THE MARGINALLY COLD AIRMASS. FURTHER EAST INTO
VT...LIKELY A MIX TRANSITIONING SLOWLY TO MAINLY AN ALL RAIN
SCENARIO AS THE DAY DAWNS ON WEDNESDAY. MOST PROBLEMATIC WILL BE
THE POTENTIAL FOR SOME LOCALIZED/SCATTERED AREAS OF LIGHT ICING
(ESP ERN VT) DURING THE FIRST HALF OF THE NIGHT AS INITIAL SFC
EVAPORATIVE EFFECTS AND MARGINALLY COLD PAVEMENT TEMPERATURES
PROMOTE SOME LIGHT ACCUMULATIONS. MODELS CONSISTENT IN SHOWING
THIS...WITH MOST PRONOUNCED THREAT OF LIGHT ICING ACTUALLY
OCCURRING ON MID-SLOPE TERRAIN FROM 500-1500 FT ACROSS THE ERN
HALF OF VT. WITH VARIABILITY IN WIND FLOW AND PRONOUNCED WARM
THERMAL ADVECTION ALOFT...TEMPERATURES WILL REMAIN NEARLY STEADY
OR SLOWLY RISE OVERNIGHT...ESP ACROSS VT. THUS HAVE LEANED HEAVILY
ON THE RAW HOURLY WRF MODEL OUTPUT WHICH CAPTURES THESE TRENDS
BEST.
&&
.SHORT TERM /8 AM WEDNESDAY 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 /00Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 00Z THURSDAY...SNOW HAS OVERSPREAD MOST OF FORECAST AREA
WITH VSBYS LOWERING QUICKLY TO IFR AND CIGS TO MVFR. WIDESPREAD
IFR WITH AREAS OF MVFR EXPECTED THROUGH THE PERIOD. SNOW WILL
TRANSITION TO RAIN OVERNIGHT AT ALL SITES EXCEPT KMSS AND KSLK.
LOOK FOR SNOW TO MIX WITH SLEET AND POSSIBLY FREEZING RAIN BY 02Z
AT KRUT...AND BETWEEN 04-06Z AT KMPV/KBTV/KPBG/KSLK. MIX WILL THEN
CHANGE TO RAIN AT KRUT BY 04Z AND BETWEEN 06Z-10Z AT KMPV/KBTV/KPBG.
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 00Z THURSDAY THROUGH SUNDAY...
00Z THURSDAY THROUGH 18Z THURSDAY...MVFR AND IFR CATEGORIES
CONTINUE INTO THANKSGIVING MORNING. ANY MIXED PRECIPITATION
CHANGES TO ALL SNOW WEDNESDAY EVENING AND THEN AND TAPERS TO SNOW
SHOWERS THURSDAY MORNING. CEILINGS AND VISIBILITIES WILL MOVE BACK
INTO THE MVFR AND VFR CATEGORIES BY 18Z THURSDAY AS SNOW SHOWERS
COME TO AN END.
18Z THURSDAY 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 FORCAST 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 258 PM EST TUESDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
THROUGH AT LEAST MIDNIGHT. WHILE WINDS HAVE DROPPED OFF A LITTLE BIT
FROM THIS MORNING...THEY ARE STILL HOVERING AROUND 25 KNOTS AT
COLCHESTER REEF THIS AFTERNOON. A SLIGHT LULL MAY OCCUR EARLY THIS
EVENING BEFORE WINDS PICK UP AGAIN THROUGH MIDNIGHT. AFTER MIDNIGHT
THOUGH...WINDS SHIFT TO THE NORTH BY WEDNESDAY MORNING AND DECREASE
BELOW ADVISORY LEVELS. THIS LULL WILL BE BRIEF THOUGH AS A COLD
FRONT PASSES THROUGH THE REGION WEDNESDAY EVENING...WINDS WILL
SHIFT TO THE NORTHWEST AND BECOME STRONG AGAIN AT 25-35 KNOTS...WITH
WAVES BUILDING TO 4 TO 6 FEET. ANOTHER ADVISORY WILL LIKELY BE
NEEDED IN THE FUTURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
VTZ001>012-016>019.
FLOOD WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT 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 WEDNESDAY FOR NYZ028-
035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/MUCCILLI
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...RJS
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
635 PM EST TUE NOV 26 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 WEDNESDAY MORNING/...
AS OF 623 PM EST TUESDAY...GOING FORECAST REMAINS IN PRETTY GOOD
SHAPE. LIGHT SNOW HAS OVERSPREAD MUCH OF THE REGION THIS EVENING
AND WILL CONTINUE WORKING NORTHWARD AS LOW PRESSURE LOCATED IN THE
SOUTHEASTERN US MOVES NORTHEASTWARD. PRECIPITATION-TYPE REMAINS
THE MOST CHALLENGING ASPECT OF THIS SYSTEM. RAP 850/925 MB 0C
LINES DOING FAIRLY WELL SO FAR THIS EVENING DELINEATING BETWEEN
SNOW AND SLEET/FREEZING RAIN...THUS LEANED TOWARDS IT AND THE HRRR FOR
NEXT SEVERAL HOURS. CHANGEOVER AT RUTLAND AND PORTIONS OF SOUTHERN
VT TO MIXED PRECIP OR RAIN AROUND 02Z...AND MUCH OF THE REST OF THE
AREA EXCEPT THE SAINT LAWRENCE VALLEY 04-07Z. 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 THIRD 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.
PREVIOUS DISCUSSION FROM 315 PM TUESDAY...
FORECAST REMAINS MORE OR LESS ON TRACK AS WE HEAD INTO THE EVENING
AND OVERNIGHT HOURS AS LOW PRESSURE AND ASSOCIATED PRECIPITATION
ADVANCE STEADILY NORTHEAST INTO THE REGION. BOTH GLOBAL AND
MESOSCALE MODELS CONTINUE TO SHOW VERY GOOD AGREEMENT ON TRACK OF
SFC LOW AND DEPICTION/EVOLUTION OF THE MEAN 925/850/700 MB 0C LINE
ADVANCING NORTH/NORTHWESTWARD INTO THE AREA. THUS PRIOR IDEA OF A
WIDESPREAD WINTRY MIX OVERSPREADING OUR AREA STILL LOOKS RIGHT ON
TRACK. SOME LIGHT TO MODEST SNOW ACCUMULATIONS POSSIBLE DURING
THIS PERIOD...ESPECIALLY ACROSS OUR NRN NY COUNTIES WHICH WILL BE
DEEPER WITHIN THE MARGINALLY COLD AIRMASS. FURTHER EAST INTO
VT...LIKELY A MIX TRANSITIONING SLOWLY TO MAINLY AN ALL RAIN
SCENARIO AS THE DAY DAWNS ON WEDNESDAY. MOST PROBLEMATIC WILL BE
THE POTENTIAL FOR SOME LOCALIZED/SCATTERED AREAS OF LIGHT ICING
(ESP ERN VT) DURING THE FIRST HALF OF THE NIGHT AS INITIAL SFC
EVAPORATIVE EFFECTS AND MARGINALLY COLD PAVEMENT TEMPERATURES
PROMOTE SOME LIGHT ACCUMULATIONS. MODELS CONSISTENT IN SHOWING
THIS...WITH MOST PRONOUNCED THREAT OF LIGHT ICING ACTUALLY
OCCURRING ON MID-SLOPE TERRAIN FROM 500-1500 FT ACROSS THE ERN
HALF OF VT. WITH VARIABILITY IN WIND FLOW AND PRONOUNCED WARM
THERMAL ADVECTION ALOFT...TEMPERATURES WILL REMAIN NEARLY STEADY
OR SLOWLY RISE OVERNIGHT...ESP ACROSS VT. THUS HAVE LEANED HEAVILY
ON THE RAW HOURLY WRF MODEL OUTPUT WHICH CAPTURES THESE TRENDS
BEST.
&&
.SHORT TERM /8 AM WEDNESDAY 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 /00Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 18Z WEDNESDAY...VFR CONDITIONS ACROSS MOST OF THE
AREA...WITH KSLK AND KRUT EXPERIENCING MVFR CIGS. STEADY SNOW
WITH MVFR CONDITIONS ARRIVES BTWN 23Z AND 01Z AT ALL SITES.
OVERNIGHT...-SN WILL TRANSITION TO -RA...WITH MIX OF -SN AND -PL
AT VT TERMINALS AND KPBG AFTER 05Z. EXPECT ABOUT 2-3 HOURS OF
PSBL MIX THROUGHOUT VT AND KPBG...BEFORE TRANSITIONING TO -RA
BTWN 08Z AND 10Z. PRECIP SHOULD REMAIN -SN AT KMSS AND KSLK.
HEAVIER PRECIP TRIES TO MOVE IN DURING THIS PTYPE
TRANSITION...PSBLY BRINGING IFR/LIFR CONDITIONS. PRECIP DOES NOT
LOOK TO LIGHTEN TIL LATE WEDNESDAY MORNING...MAINLY ACROSS
PORTIONS OF NY.
STRONG LOW LVL JET WILL APPROACH ERN VT...CREATING LLWS OF
40-50KTS FOR KRUT AND KMPV AFTER 08Z. AT THE SFC...SOUTHERLY
WINDS AT 5-15KTS WILL CONTINUE THIS AFTN WITH SOME GUSTS NEAR
20KTS AT KBTV/KMSS. AS SFC LOW TRACKS TOWARD NYC EARLY WEDNESDAY
MORNING...WINDS WILL SHIFT OUT OF THE NORTH AT 5-10KTS.
OUTLOOK 18Z WEDNESDAY THROUGH SUNDAY...
18Z WEDNESDAY THROUGH 18Z THURSDAY...MVFR AND IFR CATEGORIES
CONTINUE INTO THANKSGIVING MORNING. PRECIPITATION CHANGES BACK TO
SNOW WEDNESDAY NIGHT AND TAPERS TO SNOW SHOWERS THURSDAY MORNING.
CEILINGS AND VISIBILITIES WILL MOVE BACK INTO THE MVFR AND VFR
CATEGORIES BY 18Z THURSDAY AS SNOW SHOWERS COME TO AN END.
18Z THURSDAY ONWARD...MAINLY VFR AS HIGH PRESSURE BUILD INTO
REGION.
&&
.HYDROLOGY...
AS OF 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 FORCAST 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 258 PM EST TUESDAY...A LAKE WIND ADVISORY REMAINS IN EFFECT
THROUGH AT LEAST MIDNIGHT. WHILE WINDS HAVE DROPPED OFF A LITTLE BIT
FROM THIS MORNING...THEY ARE STILL HOVERING AROUND 25 KNOTS AT
COLCHESTER REEF THIS AFTERNOON. A SLIGHT LULL MAY OCCUR EARLY THIS
EVENING BEFORE WINDS PICK UP AGAIN THROUGH MIDNIGHT. AFTER MIDNIGHT
THOUGH...WINDS SHIFT TO THE NORTH BY WEDNESDAY MORNING AND DECREASE
BELOW ADVISORY LEVELS. THIS LULL WILL BE BRIEF THOUGH AS A COLD
FRONT PASSES THROUGH THE REGION WEDNESDAY EVENING...WINDS WILL
SHIFT TO THE NORTHWEST AND BECOME STRONG AGAIN AT 25-35 KNOTS...WITH
WAVES BUILDING TO 4 TO 6 FEET. ANOTHER ADVISORY WILL LIKELY BE
NEEDED IN THE FUTURE.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
VTZ001>012-016>019.
FLOOD WATCH FROM WEDNESDAY MORNING THROUGH LATE WEDNESDAY
NIGHT 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 WEDNESDAY FOR NYZ028-
035.
&&
$$
SYNOPSIS...JMG
NEAR TERM...JMG/MUCCILLI
SHORT TERM...JMG
LONG TERM...KGM
AVIATION...KGM
HYDROLOGY...JMG
MARINE...LAHIFF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
321 PM CST MON NOV 25 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
A STRONGER SURGE OF COLD AIR ADVECTION WILL PUSH SOUTH INTO NORTH
DAKOTA OVERNIGHT. AFTERNOON OBS AND REFLECTIVITY NEAR ROLLA...AND
LIGHT QPF SCATTERED ALONG THE EASTERN FRINGES OF THE FORECAST AREA
IN SOME SHORT RANGE MODELS...HAVE PROMPTED INCLUSION OF FLURRIES
FROM THE TURTLE MOUNTAINS THROUGH THE JAMES RIVER VALLEY TONIGHT.
A FEW AFTERNOON OBS AT MINOT AND TIOGA...SUGGESTIVE OF FREEZING
DRIZZLE/UNKNOWN PRECIP...ARE ACTUALLY THE RESULT OF EXISTING SNOW
BEING BLOWN NEAR THE WEATHER SENSOR.
HAVE INCREASED OVERNIGHT CLOUD COVER BASED ON AFTERNOON TRENDS AND
ROBUST LOW LEVEL RH EVIDENT ON THE RAP MODEL. LOWS SHOULD BE IN THE
SINGLE DIGITS TO AROUND 10 DEGREES SOUTH. TUESDAY WILL BE THE
COLDEST DAY OF THE COMING WEEK...WITH HIGHS IN THE TEENS TO LOWER
20S SOUTHWEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM CST MON NOV 25 2013
LATEST EXTENDED SUITE CONTINUES TO SHOW AN ACTIVE PERIOD IN TERMS
OF SUCCESSIVE DRY FRONTAL SYSTEMS SLIDING THROUGH. THE NEXT
POTENTIALLY SIGNIFICANT SYSTEM MAY OCCUR MONDAY AND BEYOND.
A PROGRESSIVE PATTERN BEGINS THE LONG TERM WITH A WAVERING
BAROCLINIC ZONE SHIFTING FROM WEST TO EAST TUESDAY NIGHT AS WARM AIR
ADVECTION COMMENCES. A WEAK COLD FRONT FOLLOWS FOR WEDNESDAY/
WEDNESDAY NIGHT WITH A RETURN TO COLD AIR ADVECTION INTO EARLY
THURSDAY. NEUTRAL ADVECTION TO WEAK WARM AIR ADVECTION RESUMES
FRIDAY INTO SATURDAY. THE ONLY SUFFICIENT LIFT FOR MEASURABLE
PRECIPITATION DURING THIS TIME WOULD BE CONFINED TO THE TURTLE
MOUNTAINS WEDNESDAY AND FRIDAY NIGHT. HAVE COLLABORATED WITH OUR
EASTERN OFFICE AND INCORPORATED A SLIGHT CHC OF SNOW IN THE FAR
NORTHEAST. ANY SNOW ACCUMULATION WOULD BE MINIMAL AT BEST.
THE NEXT SYSTEM TO AFFECT WESTERN AND CENTRAL NORTH DAKOTA SHOWS
SIGNS OF LIGHT PRECIPITATION BREAKING OUT VIA WARM AIR ADVECTION
PROCESSES SUNDAY AFTERNOON INTO SUNDAY NIGHT. HOWEVER IT APPEARS
THE BULK OF PRECIPITATION WOULD BE IN THE FORM OF SNOW MONDAY INTO
MONDAY NIGHT. A DRY SLOT MAY FOLLOW FOR TUESDAY. STILL A LOT OF
UNCERTAINTY THIS FAR OUT AND WILL CONTINUE TO MONITOR FUTURE
MODELS RUNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 320 PM CST MON NOV 25 2013
EXPECT CONTINUED MAINLY MVFR CEILINGS AT KISN/KMOT/KBIS/KJMS. A
NW WIND WILL GUST BETWEEN 20 AND 30 KTS THROUGH THE AFTERNOON...WITH
THE GUSTINESS DIMINISHING THIS EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION...RP KINNEY
LONG TERM...KS
AREA FORECAST DISCUSSION
NWS TULSA OK
1117 PM CST SUN NOV 24 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
NEXT ROUND OF WINTER PRECIPITATION DEVELOPING OVER NORTH TEXAS
WILL SPREAD NE OVERNIGHT INTO SE OKLAHOMA AND EVENTUALLY NW
ARKANSAS BY 12Z WITH WIDESPREAD MVFR CONDITIONS DEVELOPING.
TEMPERATURE PROFILES CONTINUE TO SUPPORT MIX OF SLEET/SNOW WHICH
WILL EVENTUALLY TRANSITION TO LIQUID BEFORE ENDING IN THE
AFTERNOON. NE OKLAHOMA SITES SHOULD SEE SOME IMPROVEMENT IN
CEILINGS LATE IN THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 924 PM CST SUN NOV 24 2013/
..UPDATE...
DISCUSSION...
INITIAL WAVE OF MIXED WINTRY PRECIP HAS EXITED
THE FORECAST AREA...WITH SEVERAL EARLIER REPORTS
OF SLICK SPOTS/SLIDE-OFFS ACROSS SE OK/WCNTRL AR.
NEXT ROUND OF WINTER PRECIP IS CURRENTLY ORGANIZING
ACROSS NRN TX...AND PRECIP WILL BEGIN TO EXPAND
TO THE ENE OVERNIGHT AS ISENTROPIC LIFT (MOST NOTABLY
ALONG 300K SFC ATOP DRY LAYER) INCREASES. SFC TEMPS
ACROSS THE ADVISORY AREA ARE CURRENTLY RUNNING AROUND
28-32F...ALTHOUGH T/TD SPREADS SUGGEST SOME WET-BULBING
IS LIKELY ONCE PRECIP INCREASES IN COVERAGE/INTENSITY.
CURRENT FORECAST IS IN REASONABLE ENOUGH SHAPE...BUT
HAVE BUMPED UP POPS ACROSS THE SE AFTER 09Z...MORE
IN-LINE WITH LATEST HRRR OUTPUT. PRECIP MAY START AS
RAIN/SLEET ACROSS FAR SE OK...WITH A CHANGEOVER TO
SLEET...FREEZING RAIN AND POSSIBLY SOME SNOW LATER
TONIGHT. TRAVEL IMPACTS WILL MAINLY BE ON ELEVATED
ROAD SURFACES...BUT WILL NEED TO CLOSELY MONITOR SE OK.
UPDATED PRODUCTS OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 27 36 26 43 / 40 30 10 0
FSM 29 35 30 44 / 60 60 20 10
MLC 28 35 27 42 / 60 60 20 10
BVO 26 37 24 42 / 20 30 10 0
FYV 26 34 25 40 / 40 50 20 10
BYV 26 34 25 39 / 10 30 20 10
MKO 27 35 26 42 / 50 50 10 10
MIO 27 36 24 41 / 10 20 10 0
F10 26 35 26 41 / 60 40 10 10
HHW 29 35 31 43 / 80 90 40 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL NOON MONDAY FOR OKZ049-OKZ053-
OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL NOON MONDAY FOR ARZ019-ARZ020-
ARZ029.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...14
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
325 PM CST MON NOV 25 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
LEADING EDGE OF THE STRATUS/STRATOCUMULUS DECK IS FIRMLY IN PLACE
ACROSS THE EASTERN CWA...WITH A MASSIVE EXPANSION BACK TO THE
NORTH INTO CANADA. MAIN FORECAST ISSUES OVERNIGHT WILL BE CLOUD
COVER AND THE ONSET OF STRONGER COLD AIR ADVECTION. RUC13 900-850
MB RH HAS A VERY GOOD HANDLE ON CURRENT STRATUS OVER THE REGION SO
USED THAT AS A FORECAST FOR THE OVERNIGHT PERIOD. IT BASICALLY
SHOWS THE STRATUS SLOWLY OOZING SOUTHWEST ACROSS SOUTH DAKOTA
THROUGH 12Z TUESDAY. HAVE INCREASED SKY COVER FROM PREVIOUS
FORECAST AND MAY NEED TO BE BEEFED UP MORE FOR EVENING UPDATES.
WITH ADDITIONAL WEAK SHORTWAVE ENERGY MOVING SOUTH OVER THE AREA
LATE TONIGHT AND THE STRONGER COLD AIR ADVECTION...SEE NO REASON
WHY CLOUDS WOULD BREAK UP OR CEASE TO MOVE ANY FURTHER
SOUTH/SOUTHWEST INTO TUESDAY MORNING. LEFT IN THE MENTION OF
FLURRIES FOR THE EASTERN CWA LATE TONIGHT THROUGH TUESDAY MORNING
IN ASSOCIATION WITH THE WEAK SHORTWAVE ENERGY. CURRENT OBS ACROSS
NORTHEAST ND AND SOUTHERN CANADA SHOW -SN WITH VSBYS GENERALLY
ABOVE 6SM IN ASSOCIATION WITH THE WEAK WAVE. WITH THE ONSET OF
COLDER AIR ALOFT ON TUESDAY...WILL SEE HIGH TEMPS SEVERAL DEGREES
COLDER THAN MONDAY. READINGS WILL BE IN THE TEENS TO MID 20S
ACROSS THE CWA. SURFACE HIGH THEN MOVES THROUGH THE AREA TUESDAY
NIGHT WHICH SHOULD CLEAR THE SKIES AND PROVIDE FOR A PERIOD OF
LIGHT WINDS. ALTHOUGH THE RIDGE AXIS IS PRETTY NARROW AND A QUICK
MOVER...SO BY 12Z WEDNESDAY MUCH OF THE CWA IS ALREADY UNDER
SOUTHERLY SFC WIND FLOW. NOT AN IDEAL RADIATIONAL COOLING
SETUP...BUT WILL STILL GET PRETTY COLD NONETHELESS. WILL BE AROUND
0 DEGREES ACROSS THE EASTERN CWA WITH FAVORED COLD SPOTS PERHAPS
SNEAKING BELOW ZERO. HIGHS ON WEDNESDAY WILL REBOUND SOMEWHAT AS
925MB TEMPS BEGIN TO WARM ON THE BACKSIDE OF THE RETREATING SFC
HIGH. BREEZY WINDS WILL DEVELOP SO THERE WILL BE DECENT MIXING.
HIGHS WILL REMAIN BELOW NORMAL THOUGH AS THE OVERALL PATTERN
REMAINS COLD.
.LONG TERM...THURSDAY THROUGH SUNDAY
NORTHWEST FLOW ALOFT WILL BE THE PREDOMINATE UPPER PATTERN
THROUGH MOST OF THE LONG TERM PERIOD...BUT A PATTERN CHANGE
DOES SEEM TO BE ON THE HORIZON. A SHORTWAVE TROUGH DROPPING OUT
OF CANADA WILL INFLUENCE THE REGION FOR THE FRIDAY/SATURDAY TIME
FRAME...HOWEVER MOST OF THE FORCING APPEARS TO REMAIN NORTH OF OUR
CWA...AND MODEL MOISTURE PROFILES REMAIN FAIRLY DRY AT THIS POINT.
DECENT WARM AIR ADVECTION AHEAD OF THAT WAVE COULD CAUSE SOME
PTYPE ISSUES IF PRECIPITATION WERE TO MATERIALIZE OVER OUR CWA
SATURDAY. ALTHOUGH MODELS VARY ON THE STRENGTH OF THE WARM
PUSH...850 MB TEMPERATURES DO RISE ABOVE 0 C...WITH THE GFS
ADVERTISING AS HIGH AS 6 OR 7 C ACROSS OUR SOUTHERN CWA.
EITHER WAY...CONTINUED WITH THE DRY ALLBLEND FORECAST FOR NOW. BY
SUNDAY WEAK RIDING APPEARS TO BE OVER THE NORTHERN PLAINS...BUT
IT ONLY PRECEDES A MORE SIGNIFICANT UPPER LOW MOVING INTO THE
PACIFIC NORTHWEST.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A STRATUS DECK CONTINUES TO MOVE SOUTHEAST OUT OF NORTH DAKOTA AND
ACROSS NORTHEAST SOUTH DAKOTA. CIGS ARE CURRENTLY IN THE VFR
CATEGORY AT KABR AND KATY...ALTHOUGH MVFR CIGS ARE FORECAST FOR
KATY OVERNIGHT. FLURRIES ARE ALSO POSSIBLE AT KABR AND KATY
OVERNIGHT...HOWEVER DUE TO LOW AREAL COVERAGE AND LITTLE OR NO
VSBY RESTRICTIONS...DID NOT ADD LIGHT SNOW INTO THE TAF FORECAST
FOR NOW. GUSTY NORTHWEST WINDS THIS AFTERNOON WILL DECREASE TO THE
10 TO 15 KT RANGE OVERNIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TMT
LONG TERM...SERR
AVIATION...SERR
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
802 PM EST TUE NOV 26 2013
.SYNOPSIS...
A DEEP AREA OF LOW PRESSURE WILL TRACK ACROSS THE CAROLINAS
TONIGHT AND INTO NEW ENGLAND BY LATE WEDNESDAY...BRINGING HEAVY
RAINFALL AHEAD OF IT...WITH A STRONG COLD PUSH AND CHANGE OVER TO
SNOW ON THE BACK SIDE BY LATE TONIGHT AND INTO WEDNESDAY AND
WEDNESDAY EVENING. STRONG WINDS WILL CAUSE SOME BLOWING OF SNOW
LATER WEDNESDAY...ESPECIALLY AT THE HIGHER ELEVATIONS. CHILLY
TEMPERATURES WILL FOLLOW THIS WEATHER SYSTEM FOR THURSDAY AND INTO
FRIDAY. BY THE WEEKEND...HIGH PRESSURE WILL BUILD INTO THE REGION
WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 755 PM EST TUESDAY...
UPDATE TO DROP THE HIGH WIND WARNING FOR THE HIGHEST ELEVATIONS
ALONG THE BLUE RIDGE THIS EVENING. THIS BASED ON CURRENT OBS WHICH
SHOW THE WEDGE COOL POOL STILL HOLDING WITH BOTH THE VAD PROFILE
AND EVENING SOUNDING INDICATING STRONG SOUTH WINDS UP ABOVE 6K
FEET WHERE THE WARM NOSE RESIDES. LATEST MODELS KEEP THIS SETUP IN
PLACE THIS EVENING SO DROPPING THE WARNING ESPCLY GIVEN MOST SITES
ALONG THE PARKWAY SHOWING LIGHT NW-NE WINDS FOR THE MOST PART. MAY
BE ABLE TO ALSO CUT THE FLOOD WATCH SOON AS SEEING A LARGE DRY
SLOT INVADE THE AREA CURRENTLY WITH THE LATEST HRRR ONLY BRINGING
BACK SOME SHOWERS ALONG THE BLUE RIDGE AFTER MIDNIGHT JUST AHEAD
OF THE BOUNDARY TO THE WEST.
PREVIOUS DISCUSSION AS OF 415 PM EST TUESDAY...
DEEPENING LOW PRESSURE TO SLIDE UP ACROSS THE CENTRAL CAROLINAS
OVERNIGHT WITH STRONG 850 SOUTHERLY JET TO CONTINUE TO ENHANCE
UPSLOPE PRECIP ALONG BLUE RIDGE BEFORE DRY SLOT COMES IN LATER
THIS EVENING. THIS COULD ALSO RESULT IN SOME VERY STRONG WINDS AT
HIGHER ELEVATIONS ALONG BLUE RIDGE...BUT WONT LAST LONG. CONCERN
IS TREES BEING UPROOTED EVEN IF WINDS DO NOT REACH WARNING
CRITERIA...AND WOULD ONLY BE THE HIGHEST RIDGES...BUT DECIDED TO
PUT A HIGH WIND WARNING OUT THROUGH THIS EVENING JUST IN CASE.
RAINFALL AMOUNTS HAVE BEEN ANYWHERE FROM AN INCH TO 3 AND A HALF
INCHES SO FAR...BUT NO REPORTS OF FLOODING. ANOTHER INCH OR SO
POSSIBLE THROUGH THIS EVENING BEFORE DRY SLOT COMES IN...AND RATES
AFTER THAT LATE TONIGHT NOT LIKELY TO CAUSE ADDITIONAL
PROBLEMS...BUT HAVE CONTINUED FLOOD WATCH FOR FLOODING OF SMALL
STREAMS AND CREEKS THROUGH 6AM...BUT WILL LIKELY BE ABLE TO DROP
THAT EARLY.
BY THE TIME THE DEEPER COLD AIR WRAPS IN AROUND BEHIND THE EXITING
LOW WELL AFTER MIDNIGHT AND INTO WED MORNING...THE HEAVIER PRECIP
WILL BE WELL OFF TO THE EAST AND CONCERNS ABOUT ANY DEFORMATION
BANDING ARE LESS...SO SNOWFALL IN THE MOUNTAINS SHOULD BE
PRIMARILY IN UPSLOPE REGIONS...BUT SOME SPILL OVER UP TO THE BLUE
RIDGE IS LIKELY...YET MINIMAL AMOUNTS. ALSO MODELS CONTINUE TO
INDICATE THAT COLD AIR FIRST COMES IN A SHALLOW LAYER...WHICH
MIGHT ACTUALLY CHANGE THE RAIN TO SLEET BRIEFLY BEFORE THE
CHANGEOVER TO SNOW. THIS MAY LIMIT ACCUMULATIONS SOMEWHAT.
THEREFORE...ONLY WENT WITH WARNING CRITERIA SNOW FOR FAR WESTERN
UPSLOPE AREAS...BUT DECIDED TO INCLUDE THOSE ENTIRE COUNTIES IN
THE WARNING DUE TO THE WINDS ALSO BLOWING THE SNOW...AND THE
IMPACT DUE TO HIGH TRAVEL DAY AND MUCH OF IT STARTING IN THE
MORNING. WENT WITH ADVISORIES UP TO THE BLUE RIDGE AND EVEN
ROANOKE AND SHENANDOAH VALLEYS FOR SAME REASON...DESPITE EXPECTED
AMOUNTS BEING BELOW CRITERIA FOR ADVISORY. JUST AN INCH OR SO OF
SNOW ON THE INTERSTATES THIS PARTICULAR DAY...SO EARLY IN THE
SEASON...AND ALSO WITH WIND WHICH MAY BLOW SOME OF THE DRIER SNOW
LATER IN THE DAY AROUND...MAY RESULT IN MUCH GREATER IMPACT THAN
MIGHT OTHERWISE BE EXPECTED.
SOME NW WINDS ON HIGHER RIDGES COULD REACH WARNING CRITERIA ON WED BUT
DECIDED TO LEAVE THOSE JUST BELOW CRITERIA AND INCLUDED WITH
WINTER WEATHER PRODUCTS RATHER THAN SEPARATE WIND WARNINGS OR WIND
ADVISORIES...EXCEPT FOR FOOTHILLS WHERE THERE ARE NO WINTER
HEADLINES. AGAIN...BLOWING SNOW WILL NOT BE AN ISSUE UNTIL MID TO
LATE IN THE DAY WHEN SNOW BECOMES DRIER AS COLDER AIR CONTINUES TO
FILTER IN AND WINDS PICK UP. SNOW AMOUNTS EAST OF THE UPSLOPE
AREAS OF FAR WEST MAY END UP A LITTLE LESS THAN CURRENT FORECAST...
BUT AM STILL CONCERNED ABOUT IMPACT WITH EVEN A LITTLE SNOW AND
ALL THE TRAVELERS...WITH THE ADDITIONAL POTENTIAL FOR TREES TO GO
DOWN WITH ALL THE WET GROUND RESULTING POWER OUTAGES AND COLD
TEMPERATURES BEHIND THIS SYSTEM.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 230 PM EST TUESDAY...
WEDNESDAY NIGHT...THE AXIS OF THE MAIN UPPER TROUGH WILL MOVE
THROUGH THE AREA. ON THE BACKSIDE OF THE TROUGH...A STRONG PRESSURE
GRADIENT WILL CONTINUE INTO THE EVENING HOURS. WE ARE LOOKING AT
ABOUT A 9.5 MB PRESSURE GRADIENT ACROSS THE FORECAST AREA DURING THE
EVENING ALONG WITH 850 MB WINDS RANGING FROM 45 TO 55 KT FROM THE
NORTHWEST. AS THE NIGHT PROGRESSES...THE PRESSURE GRADIENT WILL
SLACKEN...BUT WE ARE STILL EXPECTING A HEALTHY 30 TO 40 KTS AT 850
MB AND A 5 MB PRESSURE GRADIENT ACROSS THE REGION AT DAYBREAK
THANKSGIVING MORNING. THE RESULT SHOULD BE WIND GUSTS ACROSS THE
MOUNTAINS WEDNESDAY EVENING IN AT LEAST WIND ADVISORY CRITERIA
LEVELS WITH HIGH WIND WARNING CRITERIA POSSIBLE AT ELEVATIONS AT OR
ABOVE 3500 FEET MSL. BY SUNRISE THANKSGIVING MORNING...GUSTS AT
HIGHER ELEVATIONS WILL HAVE DECREASED TO AROUND 30 TO 35 MPH. ACROSS
THE PIEDMONT...WIND SPEEDS WILL BE WEAKER THAN IN MOUNTAINS.
WEDNESDAY EVENING GUSTS AROUND 25 MPH WILL BE COMMON. SPEEDS WILL
DECREASE THROUGH THE NIGHT AND BE LIGHT FROM THE NORTHWEST
THANKSGIVING MORNING.
WITH SUCH STRONG NORTHWEST WINDS...THE UPSLOPE SNOW MACHINE WILL BE
IN FULL OPERATION WEDNESDAY NIGHT. THE PREFERRED UPSLOPE REGIONS OF
SOUTHEAST WEST VIRGINIA AND THE NORTHERN MOUNTAINS OF NORTH CAROLINA
SHOULD SEE A LITTLE BE MORE MEASURABLE SNOW. UP TO AN ADDITIONAL TWO
INCHES WILL BE POSSIBLE IN THESE AREAS. COVERAGE AND INTENSITY WILL
GRADUALLY DECREASE THROUGHOUT THE NIGHT. ADDITIONAL SCATTERED SNOW
SHOWERS WILL BE POSSIBLE BETWEEN THESE TWO REGIONS...AND FLURRIES
WILL BE POSSIBLE EAST TO THE CREST OF THE BLUE RIDGE...ESPECIALLY
DURING THE EVENING HOURS. EAST OF THE CREST OF THE BLUE RIDGE...THE
STRONG NORTHWEST FLOW WILL HAVE A DOWNSLOPING IMPACT WHICH WILL HELP
TO GREATLY LIMIT THE AMOUNT OF CLOUD COVER.
LOW TEMPERATURES WILL RANGE FROM 10 TO 20 ACROSS THE MOUNTAINS WITH
LOWER 20S EAST OF THE BLUE RIDGE. WITH THESE LOW TEMPERATURES AND
THE GUSTY WINDS...WIND CHILLS ACROSS THE MOUNTAINS WILL FALL INTO
THE SINGLE DIGITS WITH TEENS ACROSS THE PIEDMONT. THE HIGHER
TERRAINS OF SOUTHEAST WEST VIRGINIA MAY SEE WIND CHILLS AROUND WIND
CHILL ADVISORY LEVELS...FIVE BELOW ZERO.
FOR THANKSGIVING DAY...THE PRESSURE GRADIENT WILL CONTINUE TO WEAKEN
AND THE WIND DIRECTION BECOMES LESS FAVORABLE FOR UPSLOPE SNOW
SHOWERS. LOOK FOR UPSLOPE SNOW SHOWERS TO END BY NOON...AND WINDS IN
GENERAL BECOME WEAKER. EARLY MORNING WIND CHILLS WILL BE COMPARABLE
TO THOSE OF LATE WEDNESDAY NIGHT...BUT SHOULD RISE QUICKLY BOTH AS
WIND SPEEDS DECREASE AND TEMPERATURES RISE. HIGH TEMPERATURES WILL
RANGE FROM AROUND 30 TO THE MID 30S IN THE MOUNTAINS WITH UPPER 30S
TO LOWER 40S ACROSS THE PIEDMONT. CLOUD COVER WILL GRADUALLY DECREASE
ACROSS THE MOUNTAINS THROUGHOUT THE DAY.
THURSDAY NIGHT THROUGH FRIDAY NIGHT...HIGH PRESSURE WILL BUILD OVER
THE REGION...AND ALOFT...AND UPPER RIDGE WILL START TO BUILD OVER
THE MISSISSIPPI RIVER VALLEY. FOR OUR AREA THIS WILL YIELD A
PRECIPITATION FREE FORECAST. TEMPERATURES WILL BEGIN TO MODERATE ON
FRIDAY AS THE CENTER OF THE HIGH STARTS SHIFTING EAST OF THE AREA
AND HEIGHTS START TO RISE WITH THE RIDGE BUILDING TO OUR WEST.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 300 PM EST TUESDAY...
LOOKING AT RELATIVELY ZONAL FLOW IN THE UPPER LEVELS THROUGH THE
WEEKEND...WITH WEAK DISTURBANCES EMBEDDED WITHIN THE PATTERN TO PASS
ACROSS OUR AREA. HIGH PRESSURE WILL BECOME FIRMLY WEDGED AGAINST THE
EASTERN FACE OF THE BLUE RIDGE SATURDAY MORNING...PROVIDING A LIGHT
NORTH TO NORTHEASTERLY WIND ACROSS THE PIEDMONTS...WHILE THE
MOUNTAINS CAN EXPECT SOUTHEASTERLY UPSLOPE FLOW. EXPECT DRY
CONDITIONS WITH MOSTLY CLEAR SKIES FOR SATURDAY...WITH AFTERNOON
HIGHS CLIMBING INTO THE UPPER 30S WEST TO THE LOW 40S EAST.
FOR SUNDAY...THE ECMWF MODEL DEVELOPS A LOW PRESSURE SYSTEM ACROSS
THE CAROLINAS AS A WEAK UPPER TROUGH MOVES ACROSS THE CENTRAL
APPALACHIANS...BRINGING LIGHT RAIN INTO OUR AREA. THE GFS MODEL ON
THE OTHER HAND IS SLOWER AND LESS BULLISH WITH THIS DISTURBANCE...
AND IS INDICATING LITTLE TO NO RAIN. TRENDING MORE TOWARD THE GFS
SOLUTION FOR NOW...BUT WILL NOT TOTALLY DISCOUNT THE ECMWF AND WILL
LEAVE MENTION OF A SLIGHT CHANCE OF RAIN FOR THE FORECAST.
ON MONDAY...BOTH MODELS DEVELOP A DEEPER LOW OFF THE MID ATLANTIC
COAST AS AN UPPER LEVEL TROUGH APPROACHES FROM THE WEST...HOWEVER
BOTH MODELS ALSO KEEP MOST PRECIPITATION OFF THE COAST. WILL HOLD ON
TO A CHANCE FOR RAIN FOR NOW TO GIVE THE MODELS TIME TO GAIN BETTER
FOCUS ON THIS SYSTEM. AS THE UPPER TROUGH DOES NOT APPEAR
PARTICULARLY DEEP AND TEMPERATURES WITHIN THE LOWEST FEW THOUSAND
FEET OF THE SURFACE APPEAR TO BE SLIGHTLY ABOVE FREEZING...WITH CALL
FOR MAINLY RAIN FOR NOW.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
AS OF 700 PM EST TUESDAY...
RADAR INDICATES THE RAIN SHIELD WHICH HAS AFFECTED THE FORECAST
REGION THROUGH THE DAY IS SHIFTING NORTH OF THE AREA THIS
EVENING...WITH DRIER AIR WORKING ITS WAY IN FROM THE WEST. EXPECT
RAIN TO DIMINISH ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
THROUGH THE EVENING.
LOW PRESSURE WILL MOVE RAPIDLY NORTH ALONG THE COAST PLAIN
THROUGH THE NIGHT...WITH WINDS AT ALL TAF SITES SHIFTING
NORTHWESTERLY BY AROUND 04Z AS THIS OCCURS...DRAWING COLDER AIR
INTO THE AREA. THIS WILL CAUSE RAIN TO TURN TO SNOW THROUGH THE
NIGHT...POSSIBLY WITH A BRIEF PERIOD OF FREEZING RAIN OR SLEET.
MOST AFFECTED WILL BE LWB AND BLF...WHERE SNOW SHOWERS WILL LIMIT
VISIBILITY AT TIMES TO A MILE OR LESS. SNOW SHOWER ACTIVITY WILL
DIMINISH IN INTENSITY FURTHER EAST...BUT MAY SEE STREAMERS OF SNOW
OFF THE WESTERN RIDGES MAKE IT AS FAR AS ROA AND LYH...BRINGING
VISIBILITIES AT THESE TAF SITES TO IFR AS WELL. REGARDLESS...WITH
THE WIND SHIFT...EXPECT CEILINGS TO REMAIN BELOW 1 KFT THROUGH 12Z
AT ALL TAF SITES...WITH GRADUAL IMPROVEMENT FROM EAST TO WEST
THEREAFTER. BY 21Z...CEILINGS AT MOST TAF SITES ARE EXPECTED TO
IMPROVE TO LOW END VFR OR HIGH MVFR EXCEPT BLF...WHICH IS EXPECTED
TO REMAIN IFR INTO THURSDAY DUE TO STRONG UPSLOPE FLOW IN THE
LOCAL TERRAIN.
THE OTHER MAIN CONCERN WILL BE STRONG NORTHWEST WINDS AS THE
SYSTEM PASSES UP THE COAST. BY 12Z...THE PRESSURE GRADIENT IS
EXPECTED TO TIGHTEN TO AROUND 9MB ACROSS THE REGION...SUPPORTING
SURFACE WIND GUSTS IN THE 25KT TO 30KT RANGE THROUGH THE
DAY...POSSIBLY AS HIGH AS 35KT AT ROA. CROSS BARRIER FLOW WILL
ALSO RESULT IN MODERATE TO SEVERE LOW LEVEL TURBULENCE ACROSS THE
AREA. WIND SPEEDS WILL GRADUALLY DIMINISH AFTER 21Z...AS HIGH
PRESSURE APPROACHES FROM THE WEST.
HIGH PRESSURE WILL SETTLE ACROSS THE AREA FOR THANKSGIVING
DAY...BECOMING WEDGED AGAINST THE EASTERN FACE OF THE APPALACHIANS
INTO THE WEEKEND...RESULTING IN A PROLONGED PERIOD OF VFR
CONDITIONS.
&&
.HYDROLOGY...
AS OF 1130 AM EST TUESDAY...
STILL IN THE OPENING STAGES OF WHAT LOOKS TO BE A FAIRLY COMPLEX
HYDRO EVENT. 24-HOUR LIQUID AMOUNTS THROUGH 12Z WERE QUITE
MODEST...GENERALLY 0.25 TO 0.50 INCHES ACROSS THE SOUTHERN HALF OF
THE CWA. THE NEXT 24 HOURS WILL FEATURE HEAVY RAINFALL..THAT MUCH
SEEMS ASSURED WITH ONGOING RAINFALL AND TREMENDOUS MOISTURE
TRANSPORT FORECAST ACROSS THE BLUE RIDGE AND FOOTHILLS. MOISTURE
TRANSPORT ANOMALIES UP TO 5 STANDARD DEVIATIONS SHOWN BY THE NAM
DURING PORTIONS OF THE NEXT 24 HOURS WHICH RAISES SOME ALARMS.
BUFKIT FORECAST SOUNDING SHOW PWAT 1.4 TO 1.6 AT KGSO BY 00Z THIS
EVENING WHICH IS CLOSE TO 99TH PERCENTILE OF BUNKERS CLIMO FOR PWAT
THERE. SO TOTAL QPF IN THE 2 TO 4 INCH RANGE STILL SEEMS QUITE
LIKELY BY TONIGHT WITH HIGHER AMOUNTS FOCUSED ALONG THE FAVORED
UPSLOPE AREAS OF THE BLUE RIDGE.
HOWEVER THIS DOES NOT APPEAR TO BE MAINSTEM RIVER FLOOD PROBLEM AT
THIS POINT GIVEN THE RIVER FORECAST CENTER GUIDANCE FROM ALL OF THE
FOUR RFCS AS OF 12Z THIS MORNING. NONE OF OUR FORECAST POINTS FROM
ANY RFC ARE DRIVEN TO FLOOD STAGE WITH THE CURRENT QPF WHICH RANGES
FROM 2 TO 3 INCHES ACROSS NEARLY ALL THE BASINS BY 18Z TOMORROW
11/27 WHICH WILL COMPRISE THE PERIOD OF HYDROLOGICALLY SIGNIFICANT
RAINFALL. RIVERS WILL OBVIOUSLY BE ON THE RISE AND A FEW MAY
APPROACH BANKFULL OR ACTION STAGE (GENERALLY A FEW FEET BELOW FLOOD
STAGE). BUT THE EXTREMELY DRY ANTECEDENT CONDITIONS OF THE PAST 2
MONTHS ARE CLEARLY A MITIGATING FACTOR IN THE RIVER FLOOD FORECASTS.
STILL WILL HAVE TO CLOSELY MONITOR RIVER TRENDS VERSUS THE FORECAST
ONCE RIVERS BEGIN TO RESPOND AS HYDROLOGIC MODELS OFTEN STRUGGLE IN
HANDLING THE RUNOFF OF HEAVY RAINFALL AFTER AN EXTENDED DRY PERIOD
SUCH AS WE HAVE EXPERIENCED.
YET HYDROLOGIC ISSUES ON SMALLER BASINS MAY STILL OCCUR DUE TO
SEVERAL FACTORS. ALTHOUGH RAINFALL RATES WILL NOT BE PARTICULARLY
HIGH THEY WILL GENERALLY RANGE FROM 0.10 TO 0.25 INCHES PER HOUR FOR
AN EXTENDED DURATION AND THERE IS SOME POSSIBILITY OF ELEVATED
CONVECTION (ALTHOUGH MAINLY EAST OF CWA) WHICH COULD BUMP RATES UP
CLOSER TO 1 INCH PER HOUR. IT MAY BE DIFFICULT TO EXCEED FFG VALUES
IN THE 1-HR AND 3-HR TIME FRAMES BUT 6-HR FFG RANGES FROM 2.5 TO 3.5
INCHES AND COULD BE LOCALLY EXCEEDED IN SOME AREAS. THIS FALLING ON
TOP OF WHAT MAY BE A SATURATED SURFACE LAYER COULD EASILY LEAD TO
POCKETS OF AT LEAST MINOR FLOODING. FALL DEBRIS CAN BE QUITE
EFFECTIVE IN PRODUCING CULVERT BLOCKAGES WHICH CAN ALSO CAUSE MINOR
FLOODING ON ROADWAYS WHERE RUNOFF IS BLOCKED. FOR THESE REASONS A
FLOOD WATCH WILL BE ISSUED THROUGH 6AM BUT MORE FOR SMALL STREAM AND
ROADWAY FLOODING THAN FOR RIVER FLOODING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR
VAZ010>014-016>020-022>024.
FLOOD WATCH UNTIL 6 AM EST WEDNESDAY FOR VAZ014>017-022>024-
032>035-043.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST
WEDNESDAY FOR VAZ007-009-015.
WIND ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR VAZ032>035.
NC...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR
NCZ002.
FLOOD WATCH UNTIL 6 AM EST WEDNESDAY FOR NCZ001>004-018>020.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST
WEDNESDAY FOR NCZ001-018.
WIND ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR NCZ003-019.
WV...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM EST WEDNESDAY FOR
WVZ044.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 1 AM EST
THURSDAY FOR WVZ042-043-045.
&&
$$
SYNOPSIS...RAB/SK
NEAR TERM...JH/SK
SHORT TERM...DS
LONG TERM...NF
AVIATION...JC/NF
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1110 AM CST MON NOV 25 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 406 AM CST MON NOV 25 2013
PRIMARY FOCUS OF SHORT-TERM FORECAST WILL BE LIGHT PRECIPITATION
ASSOCIATED WITH A COUPLE RATHER POTENT NORTHERN STREAM SHORTWAVE
DISTURBANCES DIVING SOUTHEAST ACROSS THE WESTERN GREAT LAKES...AND
INCREASING LES POTENTIAL ACROSS THE LAKE SUPERIOR SNOWBELT.
WATER VAPOR IMAGERY SHOWS FIRST SHORTWAVE DISTURBANCE HEADING
SOUTHEAST TOWARD LAKE SUPERIOR EARLY THIS MORNING. PRIMARY
SYNOPTIC FORCING WITH THIS FEATURE TO REMAIN NORTH OF THE FORECAST
AREA TODAY. FORCING RATHER LACKLUSTER FURTHER SOUTH ASSOCIATED
WITH WEAK SURFACE TROUGH HEADING SOUTHEAST ACROSS MINNESOTA. 00Z
SOUNDINGS AT MPX...GRB AND ILX ONCE AGAIN SUGGEST RATHER PALTRY
DEEP LAYER MOISTURE TO WORK WITH AHEAD OF THIS SYSTEM. THUS AS
INDICATED IN LATEST RADAR DATA...HAVE ONLY BEEN ABLE TO GENERATE
BAND OF VERY WEAK RADAR RETURNS EXTENDING FROM NORTH CENTRAL
WISCONSIN TO SOUTHWEST MINNESOTA. LITTLE OR NO PRECIPITATION
ASSOCIATED WITH THIS FEATURE THUS FAR WITH JUST FLURRIES BEING
REPORTED.
MEANWHILE FURTHER SOUTH...WHERE ANOTHER VERY WEAK IMPULSE...WEAK
FRONTOGENETIC FORCING AND SLIGHTLY DEEPER MOISTURE EXIST...SCATTERED
TO BROKEN SNOW SHOWER ACTIVITY HAS BROKEN OUT OVER EASTERN IOWA.
SHORT RANGE MODEL GUIDANCE SUGGEST THAT THIS ACTIVITY WILL MOVE
ENE AND AFFECT MAINLY THE SOUTHERN THIRD OF THE FORECAST AREA THIS
MORNING. BASED ON LATEST OBSERVATIONS APPEARS MOISTURE IS DEEP
ENOUGH TO GENERATE ICE CRYSTALS RESULTING IN MAINLY SNOW RATHER
THAN FREEZING DRIZZLE. GIVEN THE POORLY ORGANIZED AND WEAK
FORCING...AND UNCERTAINTY IN AVAILABLE MOISTURE OVER THE FORECAST
AREA THIS MORNING...OPTED TO KEEP A MIX OF VERY LIGHT SNOW AND/OR
FREEZING DRIZZLE GOING FOR THE ENTIRE FORECAST AREA THROUGH ABOUT
17Z. GIVEN LATEST RADAR TRENDS AND HRRR FORECAST...APPEARS BEST
CHANCE FOR LIGHT MEASURABLE PRECIPITATION WILL BE OVER THE FOX
VALLEY THIS MORNING...THUS KEPT HIGHEST POPS THERE. WILL CONTINUE TO
MONITOR RADAR TRENDS AND SURFACE OBSERVATIONS ACROSS THIS AREA AS
THERE STILL IS POTENTIAL FOR SUFFICIENT LIGHT SNOW OR LIGHT FREEZING
DRIZZLE TO CREATE A FEW SLICK SPOTS DURING THE MORNING COMMUTE. IF
THIS DOES OCCUR...WILL HANDLE WITH SPS.
GUIDANCE ALSO SUGGESTS THAT SURFACE PRESSURE GRADIENT WILL BE
STRONGEST BETWEEN NOW AND ABOUT 15Z...AND WILL BEGIN TO RELAX
THEREAFTER AS SURFACE TROUGH SWINGS THROUGH THE AREA AROUND
MIDDAY. THUS EXPECT RATHER STRONG SOUTHWEST WINDS TO CONTINUE TO
GUST INTO THE 30-35 MPG RANGE THROUGH MID-MORNING AND DIMINISH
SOMEWHAT THEREAFTER.
NEXT AND SOMEWHAT MORE POTENT SHORTWAVE THEN IMPINGES ON THE
FORECAST AREA TOWARD DAYBREAK TUESDAY. FEEL LARGE-SCALE FORCING
WILL BE A BIT MORE ROBUST SUCH THAT MAY SEE MORE WIDESPREAD SNOW
SHOWER ACTIVITY ESPECIALLY ACROSS NORTH-CENTRAL WISCONSIN TUESDAY.
MORE IMPORTANTLY...AS THIS SYSTEM MOVES ACROSS NORTHERN WISCONSIN
TUESDAY MORNING...BOUNDARY LAYER WINDS WILL VEER TO FAVORABLE 340
DEGREE DIRECTION OVER WESTERN LAKE SUPERIOR TO INITIATE LES BANDS
ONCE AGAIN. GIVEN RATHER IMPRESSIVE SHORTWAVE PASSING THROUGH THIS
AREA...FAVORABLE FETCH AND OVER WATER INSTABILITY...ACCUMULATING
SNOWS SEEM LIKELY ACROSS NORTHWEST VILAS COUNTY STARTING AROUND
18Z TUESDAY AND CONTINUING INTO TUESDAY NIGHT. HOWEVER MODELS DO
SUGGEST BOUNDARY LAYER WINDS WILL VEER TO A LESS FAVORABLE 360
DEGREES BY 06Z WEDNESDAY. WILL LET DAY-SHIFT TAKE A CLOSER LOOK AT
THE LES POTENTIAL FOR LATER TUESDAY INTO TUESDAY NIGHT...BUT WOULD
NOT BE SURPRISED TO SEE ADVISORY HOISTED AT SOME POINT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 406 AM CST MON NOV 25 2013
UPPER LEVEL FLOW ACROSS THE NORTHERN CONUS IS FORECAST TO BECOME
LESS AMPLIFIED/MORE ZONAL BY THE END OF THE WEEK. THIS WILL RESULT
IN THE THERMAL TROUGH...THAT SHOULD BE OVER THE AREA TUESDAY
NIGHT...SHIFTING EAST OF WISCONSIN. WARM ADVECTION LATER DURING
THE WEEK WILL BRING NEAR NORMAL HIGH TEMPERATURES BY THE WEEKEND.
LAKE EFFECT SHOULD COME TO AN END IN THE FORECAST AREA BY
WEDNESDAY AFTERNOON AS A SURFACE RIDGE REACHES THE STATE. SNOW
WITH THE NEXT CLIPPER SYSTEM SHOULD REMAIN NORTH OF THE STATE...SO
ONLY SOME SLIGHT CHANCES FOR SNOW IN THE FAR NORTH ON THURSDAY.
THE NEXT SYSTEM AFTER THAT IS EXPECTED TO PUSH FARTHER SOUTH AND
BRING A CHANCE FOR SNOW SHOWERS TO NORTHERN WISCONSIN ON SATURDAY.
LITTLE MOISTURE WILL ACCOMPANY THESE SYSTEMS SO ANY ACCUMULATION
SHOULD BE MINOR.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1055 AM CST MON NOV 25 2013
FIRST BAND OF LIGHT SNOW SHIFTED EAST OF THE AREA THIS MORNING WITH
MVFR CIGS LINGERING ACROSS THE AREA. CIGS SHOULD RISE INTO THE VFR
CATEGORY LATER THIS AFTERNOON AND THIS EVENING. ATTENTION THEN TURNS
TO REINFORCING SHOT OF COLD AIR WITH ARCTIC COLD FRONT THAT WILL
SWEEP ACROSS THE AREA LATER TONIGHT INTO TUESDAY MORNING. EXPECT A
BAND OF LIGHT SNOW OR FLURRIES / MVFR CIGS ALONG THE FRONT...AS
NOTED ACROSS THE NORTHERN PLAINS LATE THIS MORNING. HAVE TRIED TO
TIME THE LIGHT SNOW IN THE 18Z TAFS. VISIBILITIES FOR A BRIEF
PERIOD OF TIME MAY BE EVEN LOWER THAN WHAT IS IN THE FORECAST AT
EACH TAF SITE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......MG
AVIATION.......ECKBERG
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
613 AM CST MON NOV 25 2013
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 406 AM CST MON NOV 25 2013
PRIMARY FOCUS OF SHORT-TERM FORECAST WILL BE LIGHT PRECIPITATION
ASSOCIATED WITH A COUPLE RATHER POTENT NORTHERN STREAM SHORTWAVE
DISTURBANCES DIVING SOUTHEAST ACROSS THE WESTERN GREAT LAKES...AND
INCREASING LES POTENTIAL ACROSS THE LAKE SUPERIOR SNOWBELT.
WATER VAPOR IMAGERY SHOWS FIRST SHORTWAVE DISTURBANCE HEADING
SOUTHEAST TOWARD LAKE SUPERIOR EARLY THIS MORNING. PRIMARY
SYNOPTIC FORCING WITH THIS FEATURE TO REMAIN NORTH OF THE FORECAST
AREA TODAY. FORCING RATHER LACKLUSTER FURTHER SOUTH ASSOCIATED
WITH WEAK SURFACE TROUGH HEADING SOUTHEAST ACROSS MINNESOTA. 00Z
SOUNDINGS AT MPX...GRB AND ILX ONCE AGAIN SUGGEST RATHER PALTRY
DEEP LAYER MOISTURE TO WORK WITH AHEAD OF THIS SYSTEM. THUS AS
INDICATED IN LATEST RADAR DATA...HAVE ONLY BEEN ABLE TO GENERATE
BAND OF VERY WEAK RADAR RETURNS EXTENDING FROM NORTHCENTRAL
WISCONSIN TO SOUTHWEST MINNESOTA. LITTLE OR NO PRECIPITATION
ASSOCIATED WITH THIS FEATURE THUS FAR WITH JUST FLURRIES BEING
REPORTED.
MEANWHILE FURTHER SOUTH...WHERE ANOTHER VERY WEAK IMPULSE...WEAK
FRONTOGENETIC FORCING AND SLIGHTLY DEEPER MOISTURE EXIST...SCATTERED
TO BROKEN SNOW SHOWER ACTIVITY HAS BROKEN OUT OVER EASTERN IOWA.
SHORT RANGE MODEL GUIDANCE SUGGEST THAT THIS ACTIVITY WILL MOVE
ENE AND AFFECT MAINLY THE SOUTHERN THIRD OF THE FORECAST AREA THIS
MORNING. BASED ON LATEST OBSERVATIONS APPEARS MOISTURE IS DEEP
ENOUGH TO GENERATE ICE CRYSTALS RESULTING IN MAINLY SNOW RATHER
THAN FREEZING DRIZZLE. GIVEN THE POORLY ORGANIZED AND WEAK
FORCING...AND UNCERTAINTY IN AVAILABLE MOISTURE OVER THE FORECAST
AREA THIS MORNING...OPTED TO KEEP A MIX OF VERY LIGHT SNOW AND/OR
FREEZING DRIZZLE GOING FOR THE ENTIRE FORECAST AREA THROUGH ABOUT
17Z. GIVEN LATEST RADAR TRENDS AND HRRR FORECAST...APPEARS BEST
CHANCE FOR LIGHT MEASURABLE PRECIPITATION WILL BE OVER THE FOX
VALLEY THIS MORNING...THUS KEPT HIGHEST POPS THERE. WILL CONTINUE TO
MONITOR RADAR TRENDS AND SURFACE OBSERVATIONS ACROSS THIS AREA AS
THERE STILL IS POTENTIAL FOR SUFFICIENT LIGHT SNOW OR LIGHT FREEZING
DRIZZLE TO CREATE A FEW SLICK SPOTS DURING THE MORNING COMMUTE. IF
THIS DOES OCCUR...WILL HANDLE WITH SPS.
GUIDANCE ALSO SUGGESTS THAT SURFACE PRESSURE GRADIENT WILL BE
STRONGEST BETWEEN NOW AND ABOUT 15Z...AND WILL BEGIN TO RELAX
THEREAFTER AS SURFACE TROUGH SWINGS THROUGH THE AREA AROUND
MIDDAY. THUS EXPECT RATHER STRONG SOUTHWEST WINDS TO CONTINUE TO
GUST INTO THE 30-35 MPG RANGE THROUGH MID-MORNING AND DIMINISH
SOMEWHAT THEREAFTER.
NEXT AND SOMEWHAT MORE POTENT SHORTWAVE THEN IMPINGES ON THE
FORECAST AREA TOWARD DAYBREAK TUESDAY. FEEL LARGE-SCALE FORCING
WILL BE A BIT MORE ROBUST SUCH THAT MAY SEE MORE WIDESPREAD SNOW
SHOWER ACTIVITY ESPECIALLY ACROSS NORTHCENTRAL WISCONSIN TUESDAY.
MORE IMPORTANTLY...AS THIS SYSTEM MOVES ACROSS NORTHERN WISCONSIN
TUESDAY MORNING...BOUNDARY LAYER WINDS WILL VEER TO FAVORABLE 340
DEGREE DIRECTION OVER WESTERN LAKE SUPERIOR TO INITIATE LES BANDS
ONCE AGAIN. GIVEN RATHER IMPRESSIVE SHORTWAVE PASSING THROUGH THIS
AREA...FAVORABLE FETCH AND OVER WATER INSTABILITY...ACCUMULATING
SNOWS SEEM LIKELY ACROSS NORTHWEST VILAS COUNTY STARTING AROUND
18Z TUESDAY AND CONTINUING INTO TUESDAY NIGHT. HOWEVER MODELS DO
SUGGEST BOUNDARY LAYER WINDS WILL VEER TO A LESS FAVORABLE 360
DEGREES BY 06Z WEDNESDAY. WILL LET DAY-SHIFT TAKE A CLOSER LOOK AT
THE LES POTENTIAL FOR LATER TUESDAY INTO TUESDAY NIGHT...BUT WOULD
NOT BE SURPRISED TO SEE ADVISORY HOISTED AT SOME POINT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 406 AM CST MON NOV 25 2013
UPPER LEVEL FLOW ACROSS THE NORTHERN CONUS IS FORECAST TO BECOME
LESS AMPLIFIED/MORE ZONAL BY THE END OF THE WEEK. THIS WILL RESULT
IN THE THERMAL TROUGH...THAT SHOULD BE OVER THE AREA TUESDAY
NIGHT...SHIFTING EAST OF WISCONSIN. WARM ADVECTION LATER DURING
THE WEEK WILL BRING NEAR NORMAL HIGH TEMPERATURES BY THE WEEKEND.
LAKE EFFECT SHOULD COME TO AN END IN THE FORECAST AREA BY
WEDNESDAY AFTERNOON AS A SURFACE RIDGE REACHES THE STATE. SNOW
WITH THE NEXT CLIPPER SYSTEM SHOULD REMAIN NORTH OF THE STATE...SO
ONLY SOME SLIGHT CHANCES FOR SNOW IN THE FAR NORTH ON THURSDAY.
THE NEXT SYSTEM AFTER THAT IS EXPECTED TO PUSH FARTHER SOUTH AND
BRING A CHANCE FOR SNOW SHOWERS TO NORTHERN WISCONSIN ON SATURDAY.
LITTLE MOISTURE WILL ACCOMPANY THESE SYSTEMS SO ANY ACCUMULATION
SHOULD BE MINOR.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 611 AM CST MON NOV 25 2013
AN UPPER-LEVEL DISTURBANCE AND ASSOCIATED SURFACE TROUGH WILL
GENERATE A BRIEF PERIOD OF LIGHT SNOW POSSIBLY MIXED WITH SOME
LIGHT FREEZING DRIZZLE THROUGH ABOUT 14Z AT GRB AND ATW TAF SITES.
MAINLY MVFR CIGS AND VSBYS EXPECTED IN THE HEAVIER SNOW SHOWERS.
PRECIPITATION SHOULD EXIT THE FOX VALLEY BY 15Z...AND WILL BE
FOLLOWED BY AREAS OF MVFR CIGS THROUGH ABOUT 20Z. STRONG SOUTHWEST
WINDS GUSTING TO 30KTS AND LLWS SHOULD DIMINISH AFTER 15Z AS PRESSURE
GRADIENT RELAXES WITH APPROACHING SURFACE TROUGH. GENERALLY VFR
CONDITIONS OVERNIGHT...EXCEPT ACROSS NORTHERN WISCONSIN WHERE MVFR
CIGS AND VSBYS ARE POSSIBLE AS ANOTHER UPPER-LEVEL DISTURBANCE
APPROACHES IN CONCERT WITH INCREASING LAKE EFFECT SNOW BANDS OFF
LAKE SUPERIOR. THE SNOW SHOWER ACTIVITY WILL BE MOST NUMEROUS OVER
VILAS COUNTY AFTER MIDNIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......MG
AVIATION.......ESB
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 406 AM CST MON NOV 25 2013
PRIMARY FOCUS OF SHORT-TERM FORECAST WILL BE LIGHT PRECIPITATION
ASSOCIATED WITH A COUPLE RATHER POTENT NORTHERN STREAM SHORTWAVE
DISTURBANCES DIVING SOUTHEAST ACROSS THE WESTERN GREAT LAKES...AND
INCREASING LES POTENTIAL ACROSS THE LAKE SUPERIOR SNOWBELT.
WATER VAPOR IMAGERY SHOWS FIRST SHORTWAVE DISTURBANCE HEADING
SOUTHEAST TOWARD LAKE SUPERIOR EARLY THIS MORNING. PRIMARY
SYNOPTIC FORCING WITH THIS FEATURE TO REMAIN NORTH OF THE FORECAST
AREA TODAY. FORCING RATHER LACKLUSTER FURTHER SOUTH ASSOCIATED
WITH WEAK SURFACE TROUGH HEADING SOUTHEAST ACROSS MINNESOTA. 00Z
SOUNDINGS AT MPX...GRB AND ILX ONCE AGAIN SUGGEST RATHER PALTRY
DEEP LAYER MOISTURE TO WORK WITH AHEAD OF THIS SYSTEM. THUS AS
INDICATED IN LATEST RADAR DATA...HAVE ONLY BEEN ABLE TO GENERATE
BAND OF VERY WEAK RADAR RETURNS EXTENDING FROM NORTHCENTRAL
WISCONSIN TO SOUTHWEST MINNESOTA. LITTLE OR NO PRECIPITATION
ASSOCIATED WITH THIS FEATURE THUS FAR WITH JUST FLURRIES BEING
REPORTED.
MEANWHILE FURTHER SOUTH...WHERE ANOTHER VERY WEAK IMPULSE...WEAK
FRONTOGENETIC FORCING AND SLIGHTLY DEEPER MOISTURE EXIST...SCATTERED
TO BROKEN SNOW SHOWER ACTIVITY HAS BROKEN OUT OVER EASTERN IOWA.
SHORT RANGE MODEL GUIDANCE SUGGEST THAT THIS ACTIVITY WILL MOVE
ENE AND AFFECT MAINLY THE SOUTHERN THIRD OF THE FORECAST AREA THIS
MORNING. BASED ON LATEST OBSERVATIONS APPEARS MOISTURE IS DEEP
ENOUGH TO GENERATE ICE CRYSTALS RESULTING IN MAINLY SNOW RATHER
THAN FREEZING DRIZZLE. GIVEN THE POORLY ORGANIZED AND WEAK
FORCING...AND UNCERTAINTY IN AVAILABLE MOISTURE OVER THE FORECAST
AREA THIS MORNING...OPTED TO KEEP A MIX OF VERY LIGHT SNOW AND/OR
FREEZING DRIZZLE GOING FOR THE ENTIRE FORECAST AREA THROUGH ABOUT
17Z. GIVEN LATEST RADAR TRENDS AND HRRR FORECAST...APPEARS BEST
CHANCE FOR LIGHT MEASURABLE PRECIPITATION WILL BE OVER THE FOX
VALLEY THIS MORNING...THUS KEPT HIGHEST POPS THERE. WILL CONTINUE TO
MONITOR RADAR TRENDS AND SURFACE OBSERVATIONS ACROSS THIS AREA AS
THERE STILL IS POTENTIAL FOR SUFFICIENT LIGHT SNOW OR LIGHT FREEZING
DRIZZLE TO CREATE A FEW SLICK SPOTS DURING THE MORNING COMMUTE. IF
THIS DOES OCCUR...WILL HANDLE WITH SPS.
GUIDANCE ALSO SUGGESTS THAT SURFACE PRESSURE GRADIENT WILL BE
STRONGEST BETWEEN NOW AND ABOUT 15Z...AND WILL BEGIN TO RELAX
THEREAFTER AS SURFACE TROUGH SWINGS THROUGH THE AREA AROUND
MIDDAY. THUS EXPECT RATHER STRONG SOUTHWEST WINDS TO CONTINUE TO
GUST INTO THE 30-35 MPG RANGE THROUGH MID-MORNING AND DIMINISH
SOMEWHAT THEREAFTER.
NEXT AND SOMEWHAT MORE POTENT SHORTWAVE THEN IMPINGES ON THE
FORECAST AREA TOWARD DAYBREAK TUESDAY. FEEL LARGE-SCALE FORCING
WILL BE A BIT MORE ROBUST SUCH THAT MAY SEE MORE WIDESPREAD SNOW
SHOWER ACTIVITY ESPECIALLY ACROSS NORTHCENTRAL WISCONSIN TUESDAY.
MORE IMPORTANTLY...AS THIS SYSTEM MOVES ACROSS NORTHERN WISCONSIN
TUESDAY MORNING...BOUNDARY LAYER WINDS WILL VEER TO FAVORABLE 340
DEGREE DIRECTION OVER WESTERN LAKE SUPERIOR TO INITIATE LES BANDS
ONCE AGAIN. GIVEN RATHER IMPRESSIVE SHORTWAVE PASSING THROUGH THIS
AREA...FAVORABLE FETCH AND OVER WATER INSTABILITY...ACCUMULATING
SNOWS SEEM LIKELY ACROSS NORTHWEST VILAS COUNTY STARTING AROUND
18Z TUESDAY AND CONTINUING INTO TUESDAY NIGHT. HOWEVER MODELS DO
SUGGEST BOUNDARY LAYER WINDS WILL VEER TO A LESS FAVORABLE 360
DEGREES BY 06Z WEDNESDAY. WILL LET DAY-SHIFT TAKE A CLOSER LOOK AT
THE LES POTENTIAL FOR LATER TUESDAY INTO TUESDAY NIGHT...BUT WOULD
NOT BE SURPRISED TO SEE ADVISORY HOISTED AT SOME POINT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 406 AM CST MON NOV 25 2013
UPPER LEVEL FLOW ACROSS THE NORTHERN CONUS IS FORECAST TO BECOME
LESS AMPLIFIED/MORE ZONAL BY THE END OF THE WEEK. THIS WILL RESULT
IN THE THERMAL TROUGH...THAT SHOULD BE OVER THE AREA TUESDAY
NIGHT...SHIFTING EAST OF WISCONSIN. WARM ADVECTION LATER DURING
THE WEEK WILL BRING NEAR NORMAL HIGH TEMPERATURES BY THE WEEKEND.
LAKE EFFECT SHOULD COME TO AN END IN THE FORECAST AREA BY
WEDNESDAY AFTERNOON AS A SURFACE RIDGE REACHES THE STATE. SNOW
WITH THE NEXT CLIPPER SYSTEM SHOULD REMAIN NORTH OF THE STATE...SO
ONLY SOME SLIGHT CHANCES FOR SNOW IN THE FAR NORTH ON THURSDAY.
THE NEXT SYSTEM AFTER THAT IS EXPECTED TO PUSH FARTHER SOUTH AND
BRING A CHANCE FOR SNOW SHOWERS TO NORTHERN WISCONSIN ON SATURDAY.
LITTLE MOISTURE WILL ACCOMPANY THESE SYSTEMS SO ANY ACCUMULATION
SHOULD BE MINOR.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 406 AM CST MON NOV 25 2013
UPPER DISTURBANCE WILL GENERATE SOME VERY LIGHT SNOW OR PERHAPS
SOME LIGHT FREEZING DRIZZLE THIS MORNING. DO NOT EXPECT THIS
PRECIPITATION TO HAVE MUCH IMPACT ON VSBYS. AS WEAK SURFACE
TROUGH PASSES SOUTHEAST ACROSS THE FORECAST AREA TOWARD MID-
DAY...MVFR CIGS WILL FOLLOW. GUSTY SOUTHWEST WINDS AND LLWS SHEAR
WILL DIMINISH LATER THIS MORNING AS PRESSURE GRADIENT RELAXES WITH
APPROACH OF THE SURFACE TROUGH. SCT-BKN MVFR CIGS EXPECTED ON
TUESDAY AS MORE POTENT UPPER DISTURBANCE MOVES ACROSS THE FORECAST
AREA. PERHAPS SOME SCT IFR CIGS AND VSBYS ASSOCIATED WITH HEAVIER
SNOW SHOWER ACTIVITY MAINLY NORTH OF RHI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......MG
AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CST SUN NOV 24 2013
.UPDATE...
ISSUED AT 933 PM CST SUN NOV 24 2013
THE MAIN FOCUS TONIGHT HAS BEEN ON THE PRECIPITATION TYPE AND
CHANCES OVERNIGHT INTO TOMORROW MORNING. CURRENTLY...THERE IS ONE
LEAD MID LEVEL SHORTWAVE TROUGH DROPPING SOUTH ACROSS CENTRAL
MINNESOTA AND NORTHERN WISCONSIN WITH ANOTHER SYSTEM IN THE
CENTRAL PLAINS. RADAR RETURNS WITH THE MN/WI TROUGH DO NOT APPEAR
TO BE REACHING THE GROUND DUE TO SOME DRY LOW TO MID LEVEL AIR
THAT IS IN PLACE ACCORDING TO 25.00Z MPX/GRB/ABR RAOBS. THE RADAR
RETURNS IN SOUTHWEST IOWA ALSO DO NOT APPEAR TO BE REACHING THE
GROUND AS WELL THANKS TO THIS DRY LOW LEVEL AIR. SO...WHILE CLOUD
COVER WILL BE ON THE INCREASE...IT APPEARS THAT THE REST OF THE
EVENING WILL BE DRY.
THE MAIN CHANCES FOR ANY PRECIPITATION LOOKS TO BE BETWEEN 3AM AND
9AM TOMORROW MORNING AS THESE TWO SYSTEMS CONVERGE ON THE AREA.
HAD HOPED TO HAVE A BETTER HANDLE ON WHETHER THERE WILL BE ICE
PRESENT AS THE LIFT COMES IN...BUT THE PAST FEW RUNS OF THE RAP
HAVE GONE BACK AND FORTH ON WHETHER THERE WILL BE ANY ICE. THIS
LEADS TO CONFIDENCE NOT BEING HIGH ENOUGH TO MOVE FORWARD ON A
POTENTIAL ADVISORY FOR FREEZING DRIZZLE SINCE THE POSSIBILITY IS
THERE THAT IT WOULD JUST BE A BRIEF PERIOD OF LIGHT SNOW.
OTHERWISE...WINDS HAVE REMAINED GUSTY THROUGHOUT THE REGION AS THE
PRESSURE GRADIENT IS STILL VERY TIGHT BETWEEN THE RETREATING HIGH
OVER THE OHIO RIVER VALLEY AND THE APPROACHING TROUGH IN THE
NORTHERN PLAINS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 201 PM CST SUN NOV 24 2013
MAIN SHORT TERM FORECAST CONCERN IS ON PRECIPITATION CHANCES LATER
TONIGHT...ALONG WITH HOW MUCH AND POTENTIAL FOR FREEZING DRIZZLE.
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING ALONG THE WEST COAST OF NORTH AMERICA...SUBTROPICAL
STREAM TROUGH OVER ARIZONA...AND NORTHERN STREAM TROUGHING FROM
CENTRAL CANADA INTO NEW ENGLAND. WITHIN THIS TROUGHING...A FAIRLY
POTENT SHORTWAVE WAS SEEN DIVING SOUTHEAST THROUGH SASKATCHEWAN.
AHEAD OF THIS TROUGH...VAD WIND PROFILES DEPICT 30-45 KT 925MB WINDS
ACROSS THE EASTERN DAKOTAS AND MINNESOTA. THESE WINDS HAVE BEEN
ADVECTING WARMER AIR TOWARDS THE FORECAST AREA...WITH 925MB TEMPS
NOW PER RAP ANALYSIS AT -7 TO -12C...COMPARED TO -12 TO -14C AT 12Z.
AIRMASS REMAINS RELATIVELY DRY...THOUGH...WITH PRECIPITABLE WATER
VALUES JUST BELOW 0.25 INCH ACROSS THE UPPER MIDWEST. UPSTREAM IN
THE WAKE OF THE SHORTWAVE...ANOTHER ARCTIC AIR SURGE WAS BREWING
ACROSS THE NORTHWEST TERRITORIES WHERE TEMPERATURES ARE SITTING IN
THE SINGLE DIGITS AND TEENS ABOVE ZERO.
MODELS ARE IN GOOD AGREEMENT SLIDING THE POTENT SHORTWAVE OVER
SASKATCHEWAN SOUTHEAST INTO NORTHERN PORTIONS OF MN...WI AND MI
MONDAY MORNING...THEN HEADING OFF TO EASTERN ONTARIO DURING THE
AFTERNOON. AS THE SHORTWAVE APPROACHES TONIGHT...SFC/925/850MB WINDS
ALL INCREASE OVER THE FORECAST AREA...SETTING UP FOR A MUCH WARMER
NIGHT. IN ADDITION...THESE WINDS WILL ADVECT IN A TONGUE OF
RELATIVELY HIGHER MOISTURE FROM WESTERN KS AND EASTERN COLORADO...AS
WELL AS FROM UP IN SOUTHERN MANITOBA...NOTED BY PRECIPITABLE WATER
CLIMBING TO AROUND 0.5 INCH. THE HIGHEST PRECIPITABLE WATER IS
CONFINED TO NORTHEAST IOWA AND SOUTHERN WI WHICH WOULD THEREFORE BE
THE GREATEST CONCERN FOR PRECIPITATION. ALBEIT...THE GENERAL LOW
AMOUNT OF PRECIPITABLE WATER WILL LIKELY LIMIT THE AMOUNT OF
PRECIPITATION. REGARDING LIFT...280-290K ISENTROPIC SURFACES DEPICT
AN INCREASE OF NET ADIABATIC OMEGA ACROSS THE FORECAST AREA BETWEEN
06 AND 12Z...THEN SLIDES OFF TO THE SOUTHEAST. GENERAL MODEL
CONSENSUS HAS BEEN HOLDING STEADY SUGGESTING PRECIPITATION BREAKING
OUT ACROSS NORTHEAST IOWA LATE TONIGHT...THEN SPREADING INTO
SOUTHERN AND PERHAPS CENTRAL WISCONSIN MONDAY MORNING. SINCE
SATURATION OCCURS FROM THE LOW TO MID LEVELS OF THE ATMOSPHERE...THE
PRECIPITATION TYPE SHOULD BE MOSTLY SNOW...BUT CANNOT RULE OUT SOME
FREEZING DRIZZLE POSSIBLE EITHER AT THE ONSET OR ON THE NORTH SIDE
OF THE DEEPER MOISTURE. ANOTHER CONCERN IS PRECIPITATION BREAKING
OUT ALONG THE POTENT SHORTWAVES WARM FRONT. 24.12Z GFS/HIRESARW AND
24.15Z SREF ALL SUGGEST THAT AS THE FRONT RUNS INTO LOW LEVEL
STRATUS WHICH DEVELOPED LATE TONIGHT AHEAD OF IT...VERTICAL MOTION
WITH THE FRONT CAN PRODUCE LIGHT PRECIPITATION. THIS WOULD APPEAR TO
BE THE BEST CHANCE TO SEE FREEZING DRIZZLE. MUCH OF THE FORECAST
AREA WOULD HAVE A CONCERN FOR THIS DEVELOPING...INCLUDING NORTHEAST
IA AND SOUTHERN WI WHEN THE SNOW THERE DEPARTS.
GIVEN THAT THE PROBABILITY OF FREEZING DRIZZLE IS LOW AT THIS
TIME...ON THE ORDER OF 20 TO MAYBE 30 PERCENT...HAVE NOT ISSUED ANY
WINTER WEATHER ADVISORIES. FURTHER SHIFTS MAY NEED TO ISSUE
THEM...THOUGH...IF FREEZING DRIZZLE LOOKS MORE LIKELY TO OCCUR.
TEMPERATURE WISE...WE SHOULD SEE TEMPERATURES HOLD EITHER NEARLY
STEADY AND LIKELY RISE AFTER MIDNIGHT AS THE BREEZY SOUTH WINDS
BRING IN WARMER AIR AT THE SURFACE. THERE IS POTENTIAL FOR SOME
CLEARING MONDAY AFTERNOON...WHICH WITH 925MB TEMPS WARMING TO -2 TO -
4C IN THE AFTERNOON...HIGHS SHOULD CLIMB INTO THE 30S IN MOST
LOCATIONS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 201 PM CST SUN NOV 24 2013
FOCUS OF THE LONG TERM PERIOD IS ON AN ARCTIC COOL SHOT SLATED FOR
TUESDAY INTO WEDNESDAY...AND ANY POSSIBLE PRECIPITATION THURSDAY
INTO THE WEEKEND.
MODELS DEPICT ANOTHER POTENT SHORTWAVE DROPPING OUT OF THE NORTHWEST
TERRITORIES AND DOWN INTO THE FORECAST AREA ON TUESDAY. THIS POTENT
SHORTWAVE REALLY HELPS TO BRING DOWN THE ARCTIC AIR OBSERVED UP
THERE. AT THE SAME TIME...WITH THE ARCTIC COLD FRONTAL PASSAGE
OCCURRING IN THE MORNING...LOW LEVEL MOISTURE GETS TRAPPED. THIS
MOISTURE COMBINED WITH DAYTIME HEATING WILL MANIFEST ITSELF INTO A
FAIRLY WIDESPREAD STRATUS DECK. STEEP LOW LEVEL LAPSE RATES ALONG
WITH THE STRATUS DECK BEING IN THE DENDRITIC GROWTH ZONE IS LIKELY
TO LEAD TO FLURRIES AT A MINIMUM...AND WOULD NOT BE SURPRISED IF
SOME LOW CHANCES OF PRECIPITATION WILL NEED TO BE ADDED.
WITH THE ARCTIC COLD FRONTAL PASSAGE TUESDAY MORNING...EXPECT
TEMPERATURES TO NOT RISE MUCH AND IF ANYTHING WILL LIKELY FALL
DURING THE AFTERNOON HOURS. 925MB TEMPS FALL TO -12C BY 00Z
WEDNESDAY AND TO AROUND -14C BY 12Z WEDNESDAY. THERE IS A CONTINUING
NORTHWEST BREEZE THROUGH THIS PERIOD WHICH WILL TEMPER A BIT ON HOW
COLD WE GET TUESDAY NIGHT...AND LEANED MORE TOWARDS THE MET GUIDANCE
FOR LOWS. ON THE FLIP SIDE...EXPECT COLDER WIND CHILLS BECAUSE OF
THE BREEZE. SOME MODERATION TAKES PLACE IN 925MB TEMPS ON WEDNESDAY
WITH SUN SO THAT TEMPERATURES CAN CLIMB BACK INTO THE LOW TO MID
20S.
THE UPPER FLOW FROM THANKSGIVING AND BEYOND LOOKS TO CHANGE...GOING
FROM THE NORTHWESTERLY PATTERN WE HAVE BEEN IN RECENTLY TOWARDS MORE
ZONAL. THERE ARE EVEN HINTS IN THE 24.12Z ECMWF OF THE FLOW BACKING
SOUTHWESTERLY EARLY NEXT WEEK. THIS PATTERN CHANGE WILL HELP
DISLODGE SOME OF THE COLD AIR...THUS FOLLOWED A CONSENSUS FORECAST
DEPICTING A GRADUAL MODERATING TREND FOR TEMPERATURES. REGARDING
PRECIPITATION CHANCES...DURING THE PATTERN CHANGE...THERE ARE
SHORTWAVE TROUGHS TRAVERSING ACROSS NORTHERN MN INTO UPPER MI ON
THANKSGIVING AND ON SATURDAY. RIGHT NOW BASED ON THE TRACK WOULD
SUGGEST THE BETTER CHANCES FOR PRECIPITATION WOULD STAY NORTH OF THE
FORECAST AREA. HOWEVER...THAT SATURDAY SHORTWAVE TROUGH APPEARS TO
TAKE A BIT FARTHER SOUTH TRACK COMPARED TO THE ONE ON
THANKSGIVING...THUS 20 PERCENT CHANCES OF SNOW ARE IN THE
FORECAST FOR BOTH SATURDAY AND SATURDAY NIGHT. FRIDAY AND SUNDAY
APPEAR DRY AT THIS TIME BETWEEN SHORTWAVE TROUGHS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1137 PM CST SUN NOV 24 2013
AS TWO SYSTEMS MERGE ACROSS THE REGION OVERNIGHT INTO MONDAY
MORNING...CHANCES FOR PRECIPITATION WILL BE RISE WITH FLIGHT
CONDITIONS LOWERING. THE MAIN PERIOD OF CONCERN IS BETWEEN 6AM AND
NOON WHEN MOISTURE DEEPENS AND THE LIFT BECOMES STRONGER.
CONFIDENCE IS NOT VERY HIGH WITH WHETHER THE POTENTIAL
PRECIPITATION TYPE WILL BE SNOW OR FREEZING DRIZZLE...BUT THE
CHANCES LOOK HIGHER THAT IT WILL BE FREEZING DRIZZLE AT LSE. RST
MAY NOT SEE ANY...SO HAVE TAKEN IT OUT OF THEIR TAF. CEILINGS WILL
LIKELY DROP TO MVFR/IFR AS THIS PRECIPITATION STARTS UP MONDAY
MORNING. WINDS HAVE REMAINED GUSTY THROUGH THE REGION WITH LOW
LEVEL WIND SHEAR CRITERIA LIKELY NOT BEING MET AT RST WITH WINDS
GUSTING TO 30-40KTS AT THE SURFACE. CONDITIONS ARE EXPECTED TO
IMPROVE INTO MONDAY NIGHT AS DRIER AIR MOVES IN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
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 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 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 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
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
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 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 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 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 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 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 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 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 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 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 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 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
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