Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/13/13
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
725 PM EST TUE NOV 12 2013
.UPDATE (TONIGHT AND WEDNESDAY)...
13/00Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NOW HIGHLY AMPLIFIED
UPPER LEVEL PATTERN ACROSS THE CONUS HIGHLIGHTED BY RIDGING OVER THE
INTER-MOUNTAIN WEST AND DOWNSTREAM PROGRESSIVE TROUGHING OVER THE
EASTERN HALF OF THE NATION. THIS EASTERN UNITED STATES TROUGH HAS
BEEN WELL HANDLED BY THE NUMERICAL MODELS THE PAST 48 HOURS AND IS
CURRENTLY DELIVERING THE COLDEST AIRMASS OF THE SEASON TO MUCH OF
THE EASTERN UNITED STATES (EVEN THE FIRST SNOWFLAKES FOR SOME). THE
AXIS OF THIS SHARP TROUGH IS CURRENTLY ALIGNED FROM EASTERN QUEBEC
DOWN THE SPINE OF THE APPALACHIANS TO THE NORTH-CENTRAL GULF OF
MEXICO. HOWEVER...AS MENTIONED ABOVE...THE TROUGH IS QUITE
PROGRESSIVE...ESPECIALLY A POTENT SHORTWAVE AT ITS BASE THAT WILL
QUICKLY TRANSLATE ACROSS THE SOUTHEASTERN STATES AND OFF THE
SOUTHEAST COAST DURING THE NEXT 12-18 HOURS.
WV IMAGERY SHOWS ABUNDANT MID/HIGH LEVEL MOISTURE STREAMING NORTH
AND NORTHEAST ACROSS THE GULF OF MEXICO AND FL PENINSULA THIS
EVENING AHEAD OF THE APPROACHING TROUGH AXIS. AT THE SAME TIME...A
SWATH OF DRY AIR/SUBSIDENCE IS NOTED DROPPING SOUTH OUT OF THE TN
VALLEY ALONG AND BEHIND THE TROUGH AXIS ASSOCIATED WITH A
SIGNIFICANT TROP FOLD AND DEEP INTRUSION OF STRATOSPHERIC AIR.
AT THE SURFACE...COLD FRONT ASSOCIATED WITH THE UPPER TROUGH IS
CURRENTLY DROPPING QUICKLY SOUTHWARD INTO THE FL PENINSULA AND WILL
PASS THROUGH THE REGION OVERNIGHT. QUITE A DIFFERENCE IN AIRMASS
ALREADY NOTED ACROSS THE STATE ON EITHER SIDE OF THIS BOUNDARY.
DEWPOINTS ALONG THE I-4 CORRIDOR AND SOUTH ARE STILL IN THE MID
60S...WHILE THE PANHANDLE IS ALREADY SEEING DEWPOINTS IN THE UPPER
30S TO 40S. SOME OF THIS DRIER AIR IS ON ITS WAY SOUTH FOR OUR
WEDNESDAY.
THE BEST HEIGHT FALLS AND SYNOPTIC FORCING FOR ASCENT ARE PASSING TO
OUR NORTH THIS EVENING WHERE COLUMN MOISTURE IS MUCH MORE LACKING.
HOWEVER...SOME WEAK QG FORCING ALONG WITH DIVERGENCE ALOFT OVER THE
EASTERN GULF WITHIN THE RRQ OF A STRENGTHENING UPPER JET STREAK IS
PROVIDING ENOUGH LIFT WITHIN THE GULF MOISTURE PLUME TO SUPPORT AN
EXPANDING AREA OF SHOWERS/SPRINKLES. THESE SHOWERS (SOME OF WHICH
ARE LIKELY EVAPORATING BEFORE REACHING THE GROUND) WILL BE CROSSING
OVER THE PENINSULA OVERNIGHT. THE WEAK FORCING FOR ASCENT AND DRYING
OF THE LOWER LEVELS WITH TIME SHOULD ONLY SUPPORT PERIODIC LIGHT
SHOWERS AND NOT AMOUNT TO MUCH. BEST CHANCES FOR LIGHT MEASURABLE
PRECIP WILL BE TO THE SOUTH OF TAMPA BAY. ANY SHOWERS SHOULD END
NORTH OF I-4 BY MIDNIGHT WITH THE FRONTAL PASSAGE...AND END BEFORE
DAWN FOR THE SOUTHERN ZONES.
IT WILL BE NOTICEABLY COOLER AND DRIER (COMPARED TO PREVIOUS
MORNINGS) BY SUNRISE FOR MUCH OF THE AREA...ESPECIALLY OVER THE
NATURE COAST. TEMPERATURES BY SUNRISE WILL BE IN THE UPPER 40S TO
MID 50S NORTH OF TAMPA BAY AND UPPER 50S TO LOWER 60S FURTHER SOUTH.
WEDNESDAY...
A FALL-FEEL WILL BE IN THE AIR. HIGH TEMPERATURES IN THE AFTERNOON
WILL RANGE FROM THE LOWER 60S OVER LEVY COUNTY...TO AROUND 70 FOR
THE I-4 CORRIDOR AND LOWER 70/MID 70S FURTHER SOUTH. COMBINE THESE
COOLER TEMPS WITH THE MUCH LOWER DEWPOINTS AND A GUSTY N/NE WIND AND
SOME MIGHT FAVOR A LIGHT JACKET FOR OUTDOOR ACTIVITIES. THIS WILL
ESPECIALLY BE TRUE AS THE SUN ANGLE DECREASES LATE IN THE DAY.
OTHERWISE...EXPECT A RAIN-FREE DAY. MOST SUN IS EXPECTED FROM TAMPA
BAY NORTHWARD WITH MORE IN THE WAY OF HIGH CLOUDS DOWN TOWARD FORT
MYERS.
&&
.AVIATION...
13/00Z-14/00Z...VFR CONDITIONS UNDER BKN-OVC MID AND HIGH CLOUDS
THAT BECOME SCT WED - ALONG WITH SOME STRATO-CU. COLD FRONT MOVES
THROUGH TONIGHT...FOR THE MOST PART DRY. CAN/T RULE OUT ISOLD -SHRA
BUT WITH LITTLE THREAT FOR THE TERMINALS. MAIN IMPACT OF THE FRONT
WILL BE INCREASING WINDS...NORTHERLY OVER NIGHT THEN NE AND GUSTY
WED.
&&
.MARINE...
HAZARDOUS BOATING CONDITIONS WILL BE DEVELOPING QUICKLY FROM NORTH
TO SOUTH OVER THE NEXT SEVERAL HOURS AS A STRONG COLD FRONT CROSSES
THE EASTERN GULF OF MEXICO. BUFKIT PROFILES OVER THE EASTERN GULF
ALL INDICATE THAT SOLID ADVISORY LEVEL WINDS FROM THE NORTH WILL
OVERSPREAD THE FORECAST WATERS WITH GUSTS TO GALE FORCE LIKELY OVER
THE NORTHERN AND OFFSHORE WATERS. THOSE AREAS NOT CURRENTLY UNDER A
GALE WARNING WILL STILL LIKELY SEE A FEW GUSTS APPROACH GALE FORCE.
EVEN THE MORE PROTECTED WATERS OF TAMPA BAY ARE FORECAST TO
EXPERIENCE SOLID ADVISORY LEVEL WINDS TONIGHT INTO WEDNESDAY. WITH
THE NORTHEAST FLOW DEVELOPING...SEAS WILL RAPIDLY BUILD AS ONE HEADS
OFFSHORE. LOCAL HI-RES WAVE MODELS INCREASE WAVES TO 6 TO 8 FEET ON
WEDNESDAY OVER THE OFFSHORE WATERS. ALTHOUGH GALE POTENTIAL SHOULD
DIMINISH WEDNESDAY NIGHT...ADVISORY LEVEL WINDS AND SEAS ARE LIKELY
TO LINGER THROUGH THE NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 56 70 52 77 / 20 0 10 10
FMY 65 75 58 79 / 30 0 10 10
GIF 57 71 52 77 / 20 10 10 10
SRQ 61 73 54 79 / 30 0 10 10
BKV 51 66 46 76 / 20 0 10 10
SPG 61 69 58 76 / 20 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...SMALL CRAFT ADVISORY FROM 1 PM WEDNESDAY TO 7 AM EST
THURSDAY FOR 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.
GALE WARNING UNTIL 1 PM EST WEDNESDAY FOR 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 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.
SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR TAMPA BAY
WATERS.
&&
$$
UPDATE/MARINE...MROCZKA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
916 PM EST TUE NOV 12 2013
.SYNOPSIS...
AN ARCTIC FRONT WILL PROGRESS THROUGH THE REGION THIS EVENING.
COLD HIGH PRESSURE WILL BUILD INTO THE AREA WEDNESDAY AND PERSIST
THROUGH LATE WEEK WHILE GRADUALLY LIFTING NORTHEAST. GULF MOISTURE
AND A COASTAL TROUGH WILL RESULT IN UNSETTLED WEATHER THIS
WEEKEND...WITH A POSSIBLE STORM SYSTEM AFFECTING THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE ARCTIC FRONT IS MOVING RAPIDLY THROUGH THE AREA THIS EVENING
BEING AIDED BY ISALLOBARIC PRESSURE RISES ON THE ORDER OF
7-8MB/3HRS. WINDS ARE CORRESPONDINGLY INCREASING WITH GUSTS TO 40+
MPH NOW COMMON ACROSS PARTS OF THE CHARLESTON TRI-COUNTY AREA.
BASED ON CURRENT TRENDS...HAVE EXPANDED THE WIND ADVISORY SOUTH TO
INCLUDE THE REMAINDER OF SOUTHEAST SOUTH CAROLINA AND A FEW
COUNTIES ALONG THE SAVANNAH RIVER IN SOUTHEAST GEORGIA.
TEMPERATURES HAVE BEEN SLOW TO FALL THIS EVENING...BUT WILL
ACCELERATE OVER THE NEXT FEW HOURS AS INTENSE COLD AIR ADVECTION
ENSUES IN THE WAKE OF THE FRONT. LOWS FROM THE LOWER 30S INLAND
TO THE UPPER 30S/LOWER 40S AT THE BEACHES LOOK ON TRACK. STILL
CAN NOT COMPLETELY RULE OUT A BRIEF FREEZE IN SOME AREAS FAR
INLAND...BUT THE SITUATION LOOKS TOO MARGINAL FOR A FREEZE
WARNING.
IMPRESSIVE DYNAMICS ASSOCIATED WITH A STRONG OF TROUGH OF LOW
PRESSURE HAVE BEEN GENERATING QUITE A BIT OF LIGHT PRECIPITATION
ACROSS THE NORTH CAROLINA AND SOUTH CAROLINA PIEDMONT THIS
EVENING. IT APPEARS THE SOUTHERN EDGE OF THIS AREA OF
PRECIPITATION WILL BRUSH THE CHARLESTON TRI-COUNTY AREA OVER THE
NEXT FEW HOURS. INCREASED POPS TO 40 PERCENT TO ACCOUNT FOR THIS.
RAP THERMAL PROFILES STILL INDICATE LIGHT RAIN MAY BRIEFLY MIX
WITH VERY LIGHT SLEET FOR AN HOUR OR TWO BEFORE ENDING. ALSO...
DESPITE MOISTURE BEING SCOURED OUT OF THE DENDRITIC GROWTH
ZONE...UPSTREAM OBSERVATIONS INDICATE SOME LIGHT SNOW HAS BEEN
ABLE TO MIX IN WITH THE LIGHT RAIN AT TIMES WITHIN CORRIDORS OF
MORE INTENSE PRECIPITATION. HAVE THEREFORE ADDED A SLIGHT CHANCE
OF LIGHT SNOW TO THE GRIDS...MAINLY ALONG AND NORTH OF I-26.
AGAIN...THIS SHOULD BE NON-ISSUE FOR TRAVEL AND MOSTLY A NOVELTY.
THE REMAINDER OF THE FORECAST AREA SHOULD REMAIN DRY FOR THE
OVERNIGHT HOURS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A STRONG CANADIAN HIGH PRESSURE WILL BLAST UNSEASONABLY
COLD AIR ACROSS THE REGION...POSSIBLY RESULTING IN AFTERNOON HIGHS
TO BE 20 PLUS DEGREES BELOW SEASONAL NORMALS. DESPITE SUNNY
SKIES...COLD AIR ADVECTION WILL ONLY ALLOW TEMPERATURES TO CLIMB
INTO THE UPPER 40S TO LOWER 50S. IN ADDITION...WINDY CONDITIONS WILL
LINGER...ESPECIALLY ALONG THE COAST AND NEAR LAKE MOULTRIE.
THEREFORE...HAVE EXTENDED THE WIND ADVISORY FOR BERKELEY AND
COASTAL COUNTIES FROM TUESDAY NIGHT INTO LATE WEDNESDAY MORNING AS
THE LOW LEVEL JET SLOWLY PULLS FURTHER OFFSHORE.
WEDNESDAY NIGHT...THE ABNORMALLY COLD TREND WILL CONTINUE AS A
WIDESPREAD FREEZE EVENT DEVELOPS. COLD ADVECTION WILL INITIALLY
PERSIST EARLY WEDNESDAY EVENING...BUT AS HIGH PRESSURE SHIFTS
EASTWARD AND SETTLES OVER THE AREA...BOUNDARY LAYER WINDS WILL
QUICKLY DIMINISH. THIS SETUP WILL ALLOW WINDS TO DECOUPLE AND
TEMPERATURES TO QUICKLY DROP UNDER MAINLY CLEAR SKIES. TEMPERATURES
WILL BOTTOM OUT IN THE MID TO UPPER 20S ACROSS MOST AREAS...WITH
LOWER TO MIDDLE 30S EXPECTED ALONG THE COAST. HAVE ISSUED A FREEZE
WATCH FOR ALL AREAS EXCEPT COASTAL GEORGIA.
THURSDAY THROUGH FRIDAY...ALTHOUGH TEMPERATURES WILL CONTINUE TO
UNDERCUT SEASONAL NORMALS...A SLOW WARMING TREND WILL DEVELOP AS THE
SURFACE HIGH PRESSURE SHIFTS NORTHEASTWARD UP THE MID-ATLANTIC
STATES AND LOW/MID LEVEL MOISTURE ACROSS THE GULF STATES SPREADS
NORTHWARD. THURSDAY TEMPERATURES WILL CLIMB INTO THE UPPER 50S TO
LOWER 60S UNDER MAINLY CLEAR SKIES. A DECENT TEMPERATURE GRADIENT
COULD DEVELOP THURSDAY NIGHT AS INCREASING CLOUDS FROM THE SOUTHWEST
PROVIDE SOME INSULATION ACROSS SOUTHEAST GEORGIA AND CLEARER SKIES
PERSIST ACROSS TO THE NORTH. THEREFORE...SHOWCASE THIS TEMPERATURE
TREND WITH LOWS IN THE UPPER 30S ACROSS NORTHERN AND INLAND LOCATIONS
AND UPPER 40S TO NEAR 50 DEGREES FURTHER SOUTH AND ALONG THE COAST.
ON FRIDAY...HIGH PRESSURE WEDGE WILL BUILD IN FROM THE NORTH AS
CLOUDS CONTINUE TO INCREASE FROM THE SOUTH. IN ADDITION...A COASTAL
TROUGH WILL DEVELOP JUST OFF THE COAST WHICH COULD SUPPORT ISOLATED
RAIN SHOWERS ALONG COASTAL AREAS. FRIDAY TEMPERATURES WILL CONTINUE
TO NUDGE WARMER WITH HIGHS IN THE MID TO UPPER 60S AND LOWS DIPPING
INTO THE UPPER 40S INLAND AND UPPER 50S ALONG THE COAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A HIGHLY UNSETTLED PATTERN IS EXPECTED IN THE LONGER RANGE DUE TO A
BROAD UPPER TROUGH SETTING UP SHOP TO OUR WEST WITH A SERIES OF
VORTS MOVING THROUGH. THE SURFACE HIGH WILL GRADUALLY SHIFT
NORTHEAST TO A POSITION OFF THE MID-ATLANTIC COAST WHICH IS A
TYPICAL COLD AIR DAMMING SCENARIO FOR US. WE EXPECT SOMEWHAT COOL
NORTHEAST FLOW TO REMAIN IN PLACE FRIDAY NIGHT THROUGH SUNDAY WITH
GULF MOISTURE MOVING IN ALOFT. AT A MINIMUM WE ARE LOOKING AT
PROLONGED CLOUDY CONDITIONS. A COASTAL TROUGH WILL PROVIDE LIFT FOR
AT LEAST SCATTERED SHOWERS OVER THE COASTAL WATERS THOUGH MODELS ARE
SPITTING OUT SCATTERED SHOWERS OVER LAND FROM TIME TO TIME. WE
BUMPED UP POPS A TAD THOUGH ARE NOT GOING WHOLE HOG UNTIL THERE IS
MORE MODEL CONSISTENCY SINCE THE TIMING OF THE BEST RAIN CHANCES IS
UNCLEAR AT THIS TIME. A STRONG WARM FRONT IS PROGGED TO LIFT NORTH
ON MONDAY WITH A COLD FRONT POTENTIALLY MOVING THROUGH MONDAY NIGHT
OR TUESDAY.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
THE COLD FRONT HAS CLEARED KCHS AND WILL MOVE THROUGH KSAV
SHORTLY. WINDS WILL INCREASE DRAMATICALLY BY 02Z AT KCHS AND 04Z
AT KSAV WITH GUSTS NEARING 30 KT. CIGS WILL LOWER SUBSTANTIALLY
WITH MARGINAL MVFR CIGS POSSIBLE BRIEFLY FROM 04-07Z AT KCHS AS AN
AREA OF LIGHT PRECIPITATION PIVOTS NORTH OF THE TERMINAL. WILL SEE
SIGNIFICANT CLEARING PRIOR TO SUNRISE WITH GUSTY WINDS LINGERING
THROUGH THE DAY WEDNESDAY.
EXTENDED AVIATION OUTLOOK...CEILING AND/OR VISIBILITY RESTRICTIONS
WILL BECOME INCREASINGLY LIKELY LATE FRIDAY THROUGH THE WEEKEND DUE
TO A COASTAL TROUGH DEVELOPING.
&&
.MARINE...
TONIGHT...UPGRADED THE GALE WARNING TO A STORM WARNING FOR THE
GEORGIA OFFSHORE WATERS...MAINLY ACROSS THE EASTERN HALF OF THAT
ZONE WHERE THE WEST WALL OF THE GULF STREAM RESIDES. UPSTREAM
OBSERVATIONS ACROSS NORTH CAROLINA AND NORTHEAST SOUTH CAROLINA
ALREADY SHOW WINDS GUSTING NEAR 45 KNOTS...AND THESE OBSERVATIONS ARE
LOCATED WITHIN THE COOLER NEARSHORE WATERS. RAP MIXING PROFILES
SHOW WINDS OF 45-50 KT WITHIN THE MIXED LAYER OCCURRING OVER THE
WESTERN WALL OF THE GULF STREAM TONIGHT...WHICH SHOULD EASILY MIX
TO THE SURFACE WHERE WATER TEMPERATURES ARE IN THE MID 70S WITHIN
THE WEST WALL. THIS SHOULD SUPPORT FREQUENT GUSTS TO STORM FORCE--
48 KT. ELSEWHERE...SOLID GALES ARE IMMINENT WITH WINDS 30-35 KT
WITH GUSTS TO 45 KT.
WEDNESDAY...HAZARDOUS MARINE CONDITIONS WITH GALE FORCE WINDS AND
DANGEROUS SEAS WILL PERSIST ACROSS THE COASTAL WATERS. THE LOW LEVEL
JET WILL SLOWLY NUDGE FURTHER OFFSHORE WEDNESDAY...ALLOWING GALES TO
END IN THE CHARLESTON HARBOR BY LATE MORNING. HOWEVER...GALES ACROSS
THE COASTAL WATERS OUTSIDE OF THE HARBOR WILL EASILY LINGER THROUGH THE
AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...MARINE CONDITIONS WILL STEADILY
IMPROVE WEDNESDAY NIGHT THROUGH THE END OF THE WEEK...AS HIGH
PRESSURE SETTLES OVER THE AREA BEFORE SLIPPING OFF THE MID ATLANTIC
COASTLINE. SMALL CRAFT ADVISORY SEAS COULD STILL PERSIST THROUGH AT
LEAST THURSDAY FOR THE OUTER GEORGIA WATERS GIVEN THE PERSISTENT
NORTHEAST FLOW.
&&
.CLIMATE...
ARCTIC HIGH PRESSURE WILL DELIVER UNSEASONABLY COLD AIR TO THE
REGION. SOME RECORD LOW MAXIMUM TEMPERATURE RECORDS COULD BE IN
JEOPARDY WEDNESDAY. IN ADDITION...EARLY THURSDAY MORNING
TEMPERATURES COULD END UP WITHIN A FEW DEGREES OF RECORD LOW FOR
THE DATE. A SUMMARY OF MIDWEEK RECORDS FOLLOWS.
WEDNESDAY NOVEMBER 13 RECORD LOW MAXIMUM TEMPERATURES...
CHS 52F...1977
SAV 50F...1920
DOWNTOWN CHARLESTON 49F...1920
THURSDAY NOVEMBER 14 RECORD LOW TEMPERATURES...
CHS 27F...1981
SAV 28F...1968
DOWNTOWN CHARLESTON 36F...1963
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR GAZ087-088-099>101-114>116-118-137-138-140.
WIND ADVISORY UNTIL 10 AM EST WEDNESDAY FOR GAZ117-119-139-141.
WIND ADVISORY UNTIL 5 AM EST WEDNESDAY FOR GAZ088-101-118.
SC...FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR SCZ040-042>045-047>052.
WIND ADVISORY UNTIL 10 AM EST WEDNESDAY FOR SCZ045-048>052.
WIND ADVISORY UNTIL 5 AM EST WEDNESDAY FOR SCZ040-042>044-047.
MARINE...GALE WARNING UNTIL 7 PM EST WEDNESDAY FOR AMZ350-352-354.
STORM WARNING UNTIL 5 AM EST WEDNESDAY FOR AMZ374.
GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR AMZ330.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
724 PM EST TUE NOV 12 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL PUSH EAST OF THE FORECAST AREA TONIGHT.
DRIER AND COLDER AIR WILL RETURN IN FORCE BEHIND THE FRONT. THIS
COLDER AIR WILL REMAIN THROUGH THURSDAY...THEN EXPECT A WARM UP
AS WE ENTER INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE STRONG COLD FRONT WILL PUSH THROUGH THE FORECAST AREA THIS
EVENING. THE COLDEST AIR OF THE SEASON SO FAR IS BEHIND THIS
FRONT. WINDY CONDITIONS WILL MAKE IT FEEL COLDER. THE LATEST
OBSERVATIONS SHOW WIND GUSTS NEAR 30 KNOTS BEHIND THE FRONT. WE
HAVE POSTED A LAKE WIND ADVISORY. THE LOW-LEVEL WESTERLY FLOW
AHEAD OF THE FRONT HAS LIMITED MOISTURE RECOVERY AHEAD OF THE
FRONT AND PRECIPITATION ASSOCIATED WITH THE FRONT WILL BE LIGHT.
RADAR TRENDS INDICATE SHOWERS WILL AFFECT MAINLY THE NORTHERN
SECTION OF THE FORECAST AREA THIS EVENING. THE HRRR SHOWS SHOWERS
ENDING FROM WEST TO EAST BY MIDNIGHT. ENOUGH COLD AIR HAS GOTTEN
INTO THE NORTH PART TO ALLOW SNOW TO MIX WITH THE RAIN. A RAIN
SNOW MIX MAY OCCUR NORTH OF COLUMBIA DURING THE EVENING. IT SHOULD
REMAIN TOO WARM FOR ANY ACCUMULATION. ROAD AND SOIL TEMPERATURES
ARE RELATIVELY WARM AND WITH THE STRONG WINDS EXPECT DRYING OF
ROADWAYS WILL LIKELY OCCUR BEFORE THE TEMPERATURES DIP BELOW
FREEZING IN THE NORTH PART DURING THE EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY THROUGH THURSDAY...COLD AND DRY HIGH PRESSURE WILL
BUILD INTO THE REGION THROUGH THE PERIOD. HIGHS ON WEDNESDAY WILL
STRUGGLE TO GET OUT OF THE 40S...EVEN WITH PLENTY OF SUNSHINE.
WINDS WILL BE STRONG AND GUSTY THROUGH THE EARLY AFTERNOON
HOURS...THEN THE PRESSURE GRADIENT BEGINS TO WEAKEN...ALLOWING THE
WINDS TO DIMINISH SLIGHTLY DURING THE AFTERNOON. THE COLDEST NIGHT
OF THE SEASON IS SET TO OCCUR WEDNESDAY NIGHT AND THURSDAY
MORNING. GUIDANCE CONTINUES TO TREND COLDER WITH EACH RUN...WITH
OVERNIGHT LOWS IN THE 20 TO 25 DEGREE RANGE QUITE LIKELY FOR MANY
AREAS. THIS WILL BE THE FIRST HARD FREEZE OF THE SEASON. THURSDAY
AND FRIDAY WILL START TO SHOW A SLOW WARMING TREND AS THE CENTER
OF THE SURFACE HIGH MOVES THROUGH AND THEN EAST OF THE CWA. HIGHS
ON THURSDAY WILL CLIMB INTO THE 50S. OVERNIGHT LOWS THURSDAY NIGHT
WILL NOT BE AS COLD...BUT READINGS WILL STILL FALL INTO THE LOWER
TO MIDDLE 30S. FRIDAY CONTINUES WITH THE WARMING TREND AS READINGS
CLIMB TO AROUND 60. AS FOR POPS...DRY WEATHER THROUGH THURSDAY
NIGHT. THEN INTRODUCE A SLIGHT CHANCE FOR RAIN BACK INTO THE
FORECAST ON FRIDAY AS SOUTHERLY RETURN FLOW BRINGS SOME MOISTURE
BACK INTO THE REGION. MODELS HINTING AS SOME WEAK ACTIVITY MOVING
ONSHORE AND TOWARDS THE CWA THROUGH THE DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LONG TERM MODELS BEGIN TO SHOW A MORE PROGRESSIVE PATTERN WITH
SOUTHWEST FLOW ALOFT ACROSS THE FORECAST AREA THIS WEEKEND.
RIDGING OVER THE ATLANTIC COAST WILL EVENTUALLY SHIFT EAST AS A
LONGWAVE TROF APPROACHES FROM THE CENTRAL US. ISENTROPIC LIFT
COULD BE STRONG ENOUGH TO GENERATE SHOWER ACTIVITY ESPECIALLY LATE
IN THE PERIOD BEFORE A COLD FRONT MOVES ACROSS THE AREA EARLY NEXT
WEEK. BROAD BRUSH OF SLIGHT CHANCE TO CHANCE POPS LOOKS GOOD THROUGH
THE PERIOD...CAN ADJUST TIMING OF ANY PRECIP AS WE GET CLOSER TO THE
WEEKEND.
TEMPERATURES BELOW NORMAL FRIDAY NIGHT...BUT WILL MODERATE THIS WEEKEND
INTO MONDAY AHEAD OF THE NEXT FRONTAL SYSTEM.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.
STRONG COLD FRONT CURRENTLY PUSHING THROUGH THE TAF SITES WILL
RESULT IN STRONG AND GUSTY WINDS THROUGH MUCH OF THE TAF PERIOD.
WSR-88D IMAGERY SHOWS SHOWERS REMAINING NORTH OF THE AREA WITH
WINDS VEERING TO NORTHERLY AND INCREASING. BY 13/00Z SUSTAINED
WINDS WILL BE AROUND 17 KNOTS WITH GUSTS TO 28 KNOTS WITH SPEEDS
SLOWING AROUND 13/07Z TO AROUND 11 KNOTS WITH GUSTS TO 18 KNOTS
THROUGH THE REMAINDER OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...EXPECT DECREASING WINDS WED MID DAY.
A SERIES OF SYSTEMS WILL CROSS THE AREA FRIDAY THROUGH
SUNDAY...LOW CONFIDENCE IN CIG/VSBY RESTRICTIONS FRIDAY AND
SATURDAY WITH HIGHER CONFIDENCE FOR SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 4 AM EST WEDNESDAY FOR SCZ015-016-018-
020>022-025>031-035>038-041.
GA...LAKE WIND ADVISORY UNTIL 4 AM EST WEDNESDAY FOR GAZ040-063>065-
077.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
632 PM EST TUE NOV 12 2013
.SYNOPSIS...
AN ARCTIC FRONT WILL PROGRESS THROUGH THE REGION THIS EVENING.
COLD HIGH PRESSURE WILL BUILD INTO THE AREA WEDNESDAY AND PERSIST
THROUGH LATE WEEK WHILE GRADUALLY LIFTING NORTHEAST. GULF MOISTURE
AND A COASTAL TROUGH WILL RESULT IN UNSETTLED WEATHER THIS
WEEKEND...WITH A POSSIBLE STORM SYSTEM AFFECTING THE AREA EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE ARCTIC FRONT IS MOVING THROUGH SOUTH CAROLINA AND GEORGIA IN
PIECES...A TYPICAL CHARACTERISTIC AS COLD AIR MASSES INTERACT
WITH THE HIGHEST HIGHER TERRAIN OF THE SOUTHERN APPALACHIANS. THE
WIND SHIFT IS MOVING STEADILY SOUTH AND HAS CLEARED THE CHARLESTON
TRI-COUNTY AREA AS OF 12/23Z WHILE THE INITIAL PUSH OF COLD...
ARCTIC AIR IS RUNNING ABOUT 1-2 HOURS BEHIND. THERMAL DECLINES
WILL BEGIN TO ACCELERATE THIS EVENING AS THE FRONT PUSHES THROUGH
AND INTENSE COLD AIR ADVECTION INITIATES. ALREADY SEEING
IMPRESSIVE ISALLOBARIC RISES IN EXCESS OF 5MB/3HRS OVER NORTH
CAROLINA--A TESTAMENT TO THE POTENCY OF THE POST FRONTAL COLD AIR
ADVECTION. OTHER THAN SOME MINOR ADJUSTMENTS TO HOURLY
TEMPERATURES...THE TEMPERATURE FORECAST IS ON TRACK WITH LOWS
RANGING FROM THE LOWER 30S WELL INLAND TO THE UPPER 30S/LOWER 40S
AT THE BEACHES. THERE ARE SOME HINTS THAT A BRIEF FREEZE COULD
OCCUR ACROSS FAR INLAND AREAS MUCH AS NORTHERN BERKELEY COUNTY AS
WELL AS PARTS OF JENKINS-SCREVEN AND ALLENDALE COUNTIES...BUT
CONFIDENCE IS NOT HIGH ENOUGH AT THIS POINT TO HOIST A FREEZE
WARNING FOR THESE LOCATIONS. TRENDS WILL BE MONITORED THROUGHOUT
THE EVENING...HOWEVER.
A VERY STRONG UPPER TROUGH WILL PIVOT THROUGH THE AREA TONIGHT.
IMPRESSIVE DYNAMICS AHEAD OF THE TROUGH ARE SUPPORTING A BROAD
AREA OF LIGHT PRECIPITATION ACROSS CENTRAL NORTH CAROLINA AND
PARTS THE NORTHERN MIDLANDS. HIGH RESOLUTION MODELS PUSH THIS
ACTIVITY STEADILY SOUTH AND SOUTHEAST...MAINLY IMPACTING AREAS
NORTH OF I-26 FOR A FEW HOURS EITHER SIDE OF MIDNIGHT. RAP THERMAL
PROFILES SUGGEST SOME LIGHT SLEET COULD MIX IN WITH THE RAIN FROM
ROUGHLY 03-06Z...BUT THIS REALLY SHOULD NOT AMOUNT TO TOO MUCH
SHOULD IT OCCUR. THE RAIN HAS MIXED WITH LIGHT SNOW WEST OF
RALEIGH/DURHAM THIS EVENING WITHIN CORRIDORS OF ENHANCED
PRECIPITATION RATES...BUT IT LOOKS LIKE ANY MEANINGFUL MOISTURE THE
MAIN DENDRITIC GROWTH ZONE WILL SCOUR OUT THIS FAR SOUTH SO LIGHT
RAIN/DRIZZLE WITH A LITTLE SLEET MIXED IN IS FAVORED OVER A
RAIN/SNOW MIX. WILL INCLUDE A SLIGHT CHANCE OF LIGHT SLEET FOR
AREAS NORTH OF I-26 WITH THE EARLY EVENING UPDATE. POPS WILL BE
CAPPED AT 20 PERCENT.
WINDS WILL INCREASE DRAMATICALLY OVER THE NEXT FEW HOURS. THE
GOING WIND ADVISORY LOOKS FINE FOR THE COASTAL COUNTIES AS WELL AS
BERKELEY COUNTY WHERE NORTH WINDS OF 20-30 MPH WITH GUSTS TO 40-45
MPH ARE LIKELY.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...A STRONG CANADIAN HIGH PRESSURE WILL BLAST UNSEASONABLY
COLD AIR ACROSS THE REGION...POSSIBLY RESULTING IN AFTERNOON HIGHS
TO BE 20 PLUS DEGREES BELOW SEASONAL NORMALS. DESPITE SUNNY
SKIES...COLD AIR ADVECTION WILL ONLY ALLOW TEMPERATURES TO CLIMB
INTO THE UPPER 40S TO LOWER 50S. IN ADDITION...WINDY CONDITIONS WILL
LINGER...ESPECIALLY ALONG THE COAST AND NEAR LAKE MOULTRIE.
THEREFORE...HAVE EXTENDED THE WIND ADVISORY FOR BERKELEY AND
COASTAL COUNTIES FROM TUESDAY NIGHT INTO LATE WEDNESDAY MORNING AS
THE LOW LEVEL JET SLOWLY PULLS FURTHER OFFSHORE.
WEDNESDAY NIGHT...THE ABNORMALLY COLD TREND WILL CONTINUE AS A
WIDESPREAD FREEZE EVENT DEVELOPS. COLD ADVECTION WILL INITIALLY
PERSIST EARLY WEDNESDAY EVENING...BUT AS HIGH PRESSURE SHIFTS
EASTWARD AND SETTLES OVER THE AREA...BOUNDARY LAYER WINDS WILL
QUICKLY DIMINISH. THIS SETUP WILL ALLOW WINDS TO DECOUPLE AND
TEMPERATURES TO QUICKLY DROP UNDER MAINLY CLEAR SKIES. TEMPERATURES
WILL BOTTOM OUT IN THE MID TO UPPER 20S ACROSS MOST AREAS...WITH
LOWER TO MIDDLE 30S EXPECTED ALONG THE COAST. HAVE ISSUED A FREEZE
WATCH FOR ALL AREAS EXCEPT COASTAL GEORGIA.
THURSDAY THROUGH FRIDAY...ALTHOUGH TEMPERATURES WILL CONTINUE TO
UNDERCUT SEASONAL NORMALS...A SLOW WARMING TREND WILL DEVELOP AS THE
SURFACE HIGH PRESSURE SHIFTS NORTHEASTWARD UP THE MID-ATLANTIC
STATES AND LOW/MID LEVEL MOISTURE ACROSS THE GULF STATES SPREADS
NORTHWARD. THURSDAY TEMPERATURES WILL CLIMB INTO THE UPPER 50S TO
LOWER 60S UNDER MAINLY CLEAR SKIES. A DECENT TEMPERATURE GRADIENT
COULD DEVELOP THURSDAY NIGHT AS INCREASING CLOUDS FROM THE SOUTHWEST
PROVIDE SOME INSULATION ACROSS SOUTHEAST GEORGIA AND CLEARER SKIES
PERSIST ACROSS TO THE NORTH. THEREFORE...SHOWCASE THIS TEMPERATURE
TREND WITH LOWS IN THE UPPER 30S ACROSS NORTHERN AND INLAND LOCATIONS
AND UPPER 40S TO NEAR 50 DEGREES FURTHER SOUTH AND ALONG THE COAST.
ON FRIDAY...HIGH PRESSURE WEDGE WILL BUILD IN FROM THE NORTH AS
CLOUDS CONTINUE TO INCREASE FROM THE SOUTH. IN ADDITION...A COASTAL
TROUGH WILL DEVELOP JUST OFF THE COAST WHICH COULD SUPPORT ISOLATED
RAIN SHOWERS ALONG COASTAL AREAS. FRIDAY TEMPERATURES WILL CONTINUE
TO NUDGE WARMER WITH HIGHS IN THE MID TO UPPER 60S AND LOWS DIPPING
INTO THE UPPER 40S INLAND AND UPPER 50S ALONG THE COAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A HIGHLY UNSETTLED PATTERN IS EXPECTED IN THE LONGER RANGE DUE TO A
BROAD UPPER TROUGH SETTING UP SHOP TO OUR WEST WITH A SERIES OF
VORTS MOVING THROUGH. THE SURFACE HIGH WILL GRADUALLY SHIFT
NORTHEAST TO A POSITION OFF THE MID-ATLANTIC COAST WHICH IS A
TYPICAL COLD AIR DAMMING SCENARIO FOR US. WE EXPECT SOMEWHAT COOL
NORTHEAST FLOW TO REMAIN IN PLACE FRIDAY NIGHT THROUGH SUNDAY WITH
GULF MOISTURE MOVING IN ALOFT. AT A MINIMUM WE ARE LOOKING AT
PROLONGED CLOUDY CONDITIONS. A COASTAL TROUGH WILL PROVIDE LIFT FOR
AT LEAST SCATTERED SHOWERS OVER THE COASTAL WATERS THOUGH MODELS ARE
SPITTING OUT SCATTERED SHOWERS OVER LAND FROM TIME TO TIME. WE
BUMPED UP POPS A TAD THOUGH ARE NOT GOING WHOLE HOG UNTIL THERE IS
MORE MODEL CONSISTENCY SINCE THE TIMING OF THE BEST RAIN CHANCES IS
UNCLEAR AT THIS TIME. A STRONG WARM FRONT IS PROGGED TO LIFT NORTH
ON MONDAY WITH A COLD FRONT POTENTIALLY MOVING THROUGH MONDAY NIGHT
OR TUESDAY.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
THE COLD FRONT HAS CLEARED KCHS AND WILL MOVE THROUGH KSAV
SHORTLY. WINDS WILL INCREASE DRAMATICALLY BY 02Z AT KCHS AND 04Z
AT KSAV WITH GUSTS NEARING 30 KT. CIGS WILL LOWER SUBSTANTIALLY
WITH MARGINAL MVFR CIGS POSSIBLE BRIEFLY FROM 04-07Z AT KCHS AS AN
AREA OF LIGHT PRECIPITATION PIVOTS NORTH OF THE TERMINAL. WILL SEE
SIGNIFICANT CLEARING PRIOR TO SUNRISE WITH GUSTY WINDS LINGERING
THROUGH THE DAY WEDNESDAY.
EXTENDED AVIATION OUTLOOK...CEILING AND/OR VISIBILITY RESTRICTIONS
WILL BECOME INCREASINGLY LIKELY LATE FRIDAY THROUGH THE WEEKEND DUE
TO A COASTAL TROUGH DEVELOPING.
&&
.MARINE...
TONIGHT...CONDITIONS ARE SET FOR A DANGEROUS AND WIDESPREAD GALE
EVENT. WINDS WILL INCREASE QUICKLY THIS EVENING AS THE ARCTIC
FRONT PUSHES OFFSHORE AND STRONG COLD AIR ADVECTION ENSUES. SOLID
GALES APPEAR LIKELY FOR ALL MARINE LEGS WITH WINDS TOPPING 30-35
KT WITH GUSTS 40-45 KT NEARSHORE WATERS AND 35-40 KT WITH GUSTS TO
45 KT OVER THE GEORGIA OFFSHORE LEG. ALREADY SEEING WINDS GUSTING
OVER 40 KT OFF THE NORTH CAROLINA OUTER BANKS. GALE WARNINGS ARE
IN PLACE FOR ALL WATERS AND WILL WILL BE MAINTAINED. THERE IS
CONCERN THAT FREQUENT GUSTS TO STORM FORCE COULD OCCUR ALONG THE
EASTERN PORTIONS OF THE GEORGIA OFFSHORE WATERS WHERE 1KM MODIS
SEA SURFACE TEMPERATURE DATA SHOWED THE WESTERN WALL STREAM IS
LURKING. RAP SOUNDINGS SUGGEST AS MUCH AS 45-50 KT OF WIND WILL
RESIDE WITHIN THE MIXED LAYER AND GIVEN THE COUNTER FLOW
CONDITIONS THAT WILL DEVELOP WITHIN THE GULF STREAM...MUCH OF THIS
WIND COULD MIX DOWN TO THE SURFACE. HAVE OPTED TO HOLD OFF ON
ISSUING A STORM WARNING FOR THIS CYCLE. PREFER TO MONITOR UPSTREAM
OBSERVATIONS OFF NORTH CAROLINA THAT RESIDE WITHIN/NEAR THE
WESTERN WALL TO SEE HOW WINDS RESPOND OVER THE NEXT FEW HOURS.
WEDNESDAY...HAZARDOUS MARINE CONDITIONS WITH GALE FORCE WINDS AND
DANGEROUS SEAS WILL PERSIST ACROSS THE COASTAL WATERS. THE LOW LEVEL
JET WILL SLOWLY NUDGE FURTHER OFFSHORE WEDNESDAY...ALLOWING GALES TO
END IN THE CHARLESTON HARBOR BY LATE MORNING. HOWEVER...GALES ACROSS
THE COASTAL WATERS OUTSIDE OF THE HARBOR WILL EASILY LINGER THROUGH THE
AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...MARINE CONDITIONS WILL STEADILY
IMPROVE WEDNESDAY NIGHT THROUGH THE END OF THE WEEK...AS HIGH
PRESSURE SETTLES OVER THE AREA BEFORE SLIPPING OFF THE MID ATLANTIC
COASTLINE. SMALL CRAFT ADVISORY SEAS COULD STILL PERSIST THROUGH AT
LEAST THURSDAY FOR THE OUTER GEORGIA WATERS GIVEN THE PERSISTENT
NORTHEAST FLOW.
&&
.CLIMATE...
ARCTIC HIGH PRESSURE WILL DELIVER UNSEASONABLY COLD AIR TO THE
REGION. SOME RECORD LOW MAXIMUM TEMPERATURE RECORDS COULD BE IN
JEOPARDY WEDNESDAY. IN ADDITION...EARLY THURSDAY MORNING
TEMPERATURES COULD END UP WITHIN A FEW DEGREES OF RECORD LOW FOR
THE DATE. A SUMMARY OF MIDWEEK RECORDS FOLLOWS.
WEDNESDAY NOVEMBER 13 RECORD LOW MAXIMUM TEMPERATURES...
CHS 52F...1977
SAV 50F...1920
DOWNTOWN CHARLESTON 49F...1920
THURSDAY NOVEMBER 14 RECORD LOW TEMPERATURES...
CHS 27F...1981
SAV 28F...1968
DOWNTOWN CHARLESTON 36F...1963
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR GAZ087-088-099>101-114>116-118-137-138-140.
WIND ADVISORY UNTIL 10 AM EST WEDNESDAY FOR GAZ117-119-139-141.
SC...FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING
FOR SCZ040-042>045-047>052.
WIND ADVISORY UNTIL 10 AM EST WEDNESDAY FOR SCZ045-048>052.
MARINE...GALE WARNING UNTIL 7 PM EST WEDNESDAY FOR AMZ350-352-354.
GALE WARNING UNTIL 1 AM EST THURSDAY FOR AMZ374.
GALE WARNING UNTIL 10 AM EST WEDNESDAY FOR AMZ330.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
327 AM EST MON NOV 11 2013
.SYNOPSIS...
DRY HIGH PRESSURE WILL DOMINATE THROUGH MONDAY. A STRONG COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...A DRY COLD FRONT IS IN THE PROCESS OF MOVING
THROUGH THE SOUTHERN PART OF THE FA AND THE CSRA EARLY THIS MORNING.
THE FRONT WILL CONTINUE MOVING SOUTHWARD POSSIBLY MOVING SOUTH OF
THE AREA BY DAYBREAK, INCREASED MIXING ASSOCIATED WITH RELATIVELY
WARM WATER TEMPERATURES WILL RESULT IN BREEZY CONDITIONS BEHIND
THE FRONT ON AREA LAKES. THE HRRR SHOWS LAKE WINDS CURRENTLY ABOUT
15 KNOTS WELL BELOW THE LAKE WIND ADVISORY CRITERIA. VWP SHOWS 1
KFT WINDS 35 KT AND THE RUC13 FORECAST SOUNDING ALSO SHOWS 1500
FOOT WINDS NE 33 KT AT 09Z WHILE NAM BUFR SOUNDING GIVE 1500 FOOT
WINDS NE AT 28 KT. SO IF WINDS MIX DOWN ON LAKE MARION...THERE
COULD BE SOME WIND GUSTS IN THE 20-25 KT RANGE. SOUNDINGS INDICATE
A LOW LEVEL INVERSION BUT HRRR TEMPERATURES OVER LAKE MARION ARE
50-55 DEGREES. SO THE WINDS MAY MIX DOWN. SURFACE TEMPERATURES ARE
IN THE 40S. WILL CONTINUE TO MONITOR FOR THE NEXT FEW HOURS.
MONDAY...HIGH PRESSURE WILL CONTINUE TO BUILD SOUTHWARD INTO THE
REGION WITH DRIER AIR AND TEMPERATURES COOLER THAN YESTERDAY.
A DECREASING PRESSURE GRADIENT SHOULD ALLOW WINDS TO DROP OFF
LATER THIS MORNING. RIGHT NOW WILL CONTINUE LAKE WIND ADVISORY
FOR LAKE MARION UNTIL 11 AM BUT WINDS MAY DROP OFF 2-3 HOURS
EARLY. WILL CONTINUE TO MONITOR. HIGH TEMPERATURES LOWER 60S
NORTH TO UPPER 60S SOUTH STILL LOOK OK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
MODELS IN GOOD AGREEMENT WITH PATTERN CHANGE TUESDAY AS HIGHLY
AMPLIFIED POSITIVELY TILTED UPPER-LEVEL TROUGH DEVELOPS IN THE
EASTERN STATES...RIDGE OUT WEST. THIS TROUGH WILL TRANSPORT VERY
COLD AIR FOR THIS TIME OF YEAR INTO THE SOUTHEAST...ARCTIC AIR
MASS ORIGIN. LATEST MODELS RUN SUGGEST MORE CLOUDINESS BY EARLY
AFTERNOON AS FRONT APPROACHES SO CUT TEMPERATURES FROM PREVIOUS
FORECAST AND INCREASED WINDS BEHIND THE FRONT AS STRONG COLD
ADVECTION DEVELOPS. THE FRONT SHOULD PUSH THROUGH THE AREA BY LATE
TUESDAY.
THE COLDEST AIR OF THE SEASON WILL SPREAD ACROSS THE REGION
TUESDAY NIGHT. PRECIPITATION MAY MOVE THROUGH THE AREA...ALTHOUGH
QPF EXPECTED TO BE QUITE LOW. MODELS APPEAR TO BE COMING MORE INTO
ALIGNMENT WITH THE UPCOMING WEATHER EVENT. MODELS ARE TRENDING
LESS AGGRESSIVE IN BRINGING IN ANY SORT OF BRIEF WINTRY MIX THAN
PREVIOUS RUNS. IN FACT...LATEST GFS AND NAM KEEP PRECIPITATION ALL
LIQUID FOR LATE TUESDAY NIGHT. NAM AND GFS BUFKIT INDICATING
RELATIVELY SHALLOW MOISTURE WELL BELOW THE SNOW GROWTH ZONE. BEST
SYNOPTIC LIFT WILL BE MAINLY OVER THE NC MOUNTAINS. POPS AND QPFS
REMAIN LOW. OVERNIGHT LOWS SHOULD DIP INTO THE LOWER TO MIDDLE
30S EARLY WEDNESDAY MORNING...BUT THE BULK OF THE MOISTURE WILL
HAVE MOVED EAST OF THE AREA BY THE TIME THE COLDEST TEMPERATURES
ARRIVE AROUND SUNRISE WEDNESDAY. HIGHS WEDNESDAY WILL RANGE FROM
THE MID 40S NORTH TO THE LOWER 50S SOUTH. WITH A DEVELOPING TIGHT
PRESSURE GRADIENT...IT WILL BECOME RATHER BREEZY TUESDAY NIGHT
INTO WEDNESDAY WITH SUSTAINED WIND SPEEDS OF 15 TO 25 MPH FROM THE
NORTH AND NORTHEAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WINDS WILL SUBSIDE BY LATE WEDNESDAY AS HIGH PRESSURE BUILDS IN
FROM THE WEST. HIGH PRESSURE EXPECTED TO CONTINUE INTO FRIDAY. THE
GFS AND ECMWF SHOW A DEVELOPING WARM FRONT WITH WEAK ISENTROPIC
LIFT SUPPORTING LOW CHANCE POPS SATURDAY AND SUNDAY.
TEMPERATURES BELOW NORMAL THROUGH FRIDAY...MUCH BELOW WEDNESDAY
AND THURSDAY. TEMPERATURES WILL MODERATE SATURDAY AND SUNDAY AHEAD
OF THE NEXT FRONTAL SYSTEM.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
A DRY FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE REGION
OVERNIGHT/EARLY THIS MORNING. INFLUX OF DRIER AIR ALONG WITH SOME
WIND IS EXPECTED TO PRECLUDE FOG FORMATION. HIGH PRESSURE CENTER
WILL BUILD IN THIS AFTERNOON...LEADING TO DECREASING WIND SPEEDS.
EXTENDED AVIATION OUTLOOK...A COLD FRONT AND UPPER LEVEL TROUGH WILL
MOVE THROUGH THE REGION TUESDAY NIGHT INTO EARLY
WEDNESDAY...PROVIDING A SLIGHT CHANCE OF LIGHT PRECIPITATION...AND
ASSOCIATED RESTRICTIONS. BREEZY CONDITIONS WILL BE POSSIBLE AS WELL
TUE NT/WED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR SCZ031-
036>038.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
146 AM EST MON NOV 11 2013
.SYNOPSIS...
DRY HIGH PRESSURE WILL DOMINATE THROUGH MONDAY. A STRONG COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A DRY COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TONIGHT.
INCREASED MIXING ASSOCIATED WITH RELATIVELY WARM WATER
TEMPERATURES WILL RESULT IN BREEZY CONDITIONS BEHIND THE FRONT ON
AREA LAKES. THE HRRR SHOWS LAKE WINDS CURRENTLY ABOUT 15 KNOTS
WELL BELOW THE LAKE WIND ADVISORY CRITERIA. VWP SHOWS 1 KFT WINDS
30 KT AND THE RUC13 FORECAST SOUNDING ALSO SHOWS 1500 FOOT WINDS
NE 33 KT AT 09Z WHILE NAM BUFR SOUNDING GIVE 1500 FOOT WINDS NE
AT 28 KT. SO IF WINDS MIX DOWN ON LAKE MARION...THERE COULD BE
SOME WIND GUSTS IN THE 20-25 KT RANGE. SOUNDINGS INDICATE A LOW
LEVEL INVERSION BUT HRRR TEMPERATURES OVER LAKE MARION ARE 50-55
DEGREES. SO THE WINDS MAY MIX DOWN. SURFACE TEMPERATURES ARE IN
THE 40S. WILL CONTINUE TO MONITOR FOR THE NEXT FEW HOURS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
DRY HIGH PRESSURE DOMINATES THROUGH MONDAY. MODELS IN GOOD
AGREEMENT WITH PATTERN CHANGE TUESDAY AS HIGHLY AMPLIFIED
POSITIVELY TILTED UPPER-LEVEL TROUGH DEVELOPS IN THE EASTERN
STATES...RIDGE OUT WEST. THIS TROUGH WILL TRANSPORT VERY COLD AIR
FOR THIS TIME OF YEAR INTO THE SOUTHEAST...ARCTIC AIR MASS ORIGIN.
LATEST MODELS RUN SUGGEST MORE CLOUDINESS BY EARLY AFTERNOON AS
FRONT APPROACHES SO CUT TEMPERATURES FROM PREVIOUS FORECAST AND
INCREASED WINDS BEHIND THE FRONT AS STRONG COLD ADVECTION
DEVELOPS. THE FRONT SHOULD PUSH THROUGH THE AREA BY LATE TUESDAY.
THE COLDEST AIR OF THE SEASON WILL SPREAD ACROSS THE REGION
TUESDAY NIGHT. PRECIPITATION MAY MOVE THROUGH THE AREA...ALTHOUGH
QPF EXPECTED TO BE QUITE LOW. MODELS APPEAR TO BE COMING MORE INTO
ALIGNMENT WITH THE UPCOMING WEATHER EVENT. MODELS ARE TRENDING
LESS AGGRESSIVE IN BRINGING IN ANY SORT OF BRIEF WINTRY MIX THAN
PREVIOUS RUNS. IN FACT...LATEST GFS AND NAM KEEP PRECIPITATION ALL
LIQUID FOR LATE TUESDAY NIGHT. NAM AND GFS BUFKIT INDICATING
RELATIVELY SHALLOW MOISTURE WELL BELOW THE SNOW GROWTH ZONE. BEST
SYNOPTIC LIFT WILL BE MAINLY OVER THE NC MOUNTAINS. POPS AND QPFS
REMAIN LOW. OVERNIGHT LOWS SHOULD DIP INTO THE LOWER TO MIDDLE
30S EARLY WEDNESDAY MORNING...BUT THE BULK OF THE MOISTURE WILL
HAVE MOVED EAST OF THE AREA BY THE TIME THE COLDEST TEMPERATURES
ARRIVE AROUND SUNRISE WEDNESDAY. HIGHS WEDNESDAY WILL RANGE FROM
THE MID 40S NORTH TO THE LOWER 50S SOUTH. WITH A DEVELOPING TIGHT
PRESSURE GRADIENT...IT WILL BECOME RATHER BREEZY TUESDAY NIGHT
INTO WEDNESDAY WITH SUSTAINED WIND SPEEDS OF 15 TO 25 MPH FROM THE
NORTH AND NORTHEAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WINDS WILL SUBSIDE BY LATE WEDNESDAY AS HIGH PRESSURE BUILDS IN
FROM THE WEST. HIGH PRESSURE EXPECTED TO CONTINUE INTO FRIDAY. THE
GFS AND ECMWF SHOW A DEVELOPING WARM FRONT WITH WEAK ISENTROPIC
LIFT SUPPORTING LOW CHANCE POPS SATURDAY AND SUNDAY.
TEMPERATURES BELOW NORMAL THROUGH FRIDAY...MUCH BELOW WEDNESDAY
AND THURSDAY. TEMPERATURES WILL MODERATE SATURDAY AND SUNDAY AHEAD
OF THE NEXT FRONTAL SYSTEM.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
A DRY FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE REGION
OVERNIGHT/EARLY THIS MORNING. INFLUX OF DRIER AIR ALONG WITH SOME
WIND IS EXPECTED TO PRECLUDE FOG FORMATION. HIGH PRESSURE CENTER
WILL BUILD IN THIS AFTERNOON...LEADING TO DECREASING WIND SPEEDS.
EXTENDED AVIATION OUTLOOK...A COLD FRONT AND UPPER LEVEL TROUGH WILL
MOVE THROUGH THE REGION TUESDAY NIGHT INTO EARLY
WEDNESDAY...PROVIDING A SLIGHT CHANCE OF LIGHT PRECIPITATION...AND
ASSOCIATED RESTRICTIONS. BREEZY CONDITIONS WILL BE POSSIBLE AS WELL
TUE NT/WED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR SCZ031-
036>038.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1237 AM EST MON NOV 11 2013
.SYNOPSIS...
DRY HIGH PRESSURE WILL DOMINATE THROUGH MONDAY. A STRONG COLD
FRONT WILL MOVE THROUGH THE FORECAST AREA LATE TUESDAY OR EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A DRY COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TONIGHT.
INCREASED MIXING ASSOCIATED WITH RELATIVELY WARM WATER
TEMPERATURES WILL RESULT IN BREEZY CONDITIONS BEHIND THE FRONT ON
AREA LAKES. THE HRRR INDICATES LAKE WIND ADVISORY CRITERIA ON LAKE
MARION. THE PRESSURE GRADIENT APPEARS A LITTLE LESS FARTHER WEST.
SATELLITE TRENDS SUPPORT MOSTLY CLEAR SKIES. MIXING SHOULD HELP
HOLD UP TEMPERATURES. WE LEANED TOWARD THE WARMER TEMPERATURE
GUIDANCE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
DRY HIGH PRESSURE DOMINATES THROUGH MONDAY. MODELS IN GOOD
AGREEMENT WITH PATTERN CHANGE TUESDAY AS HIGHLY AMPLIFIED
POSITIVELY TILTED UPPER-LEVEL TROUGH DEVELOPS IN THE EASTERN
STATES...RIDGE OUT WEST. THIS TROUGH WILL TRANSPORT VERY COLD AIR
FOR THIS TIME OF YEAR INTO THE SOUTHEAST...ARCTIC AIR MASS ORIGIN.
LATEST MODELS RUN SUGGEST MORE CLOUDINESS BY EARLY AFTERNOON AS
FRONT APPROACHES SO CUT TEMPERATURES FROM PREVIOUS FORECAST AND
INCREASED WINDS BEHIND THE FRONT AS STRONG COLD ADVECTION
DEVELOPS. THE FRONT SHOULD PUSH THROUGH THE AREA BY LATE TUESDAY.
THE COLDEST AIR OF THE SEASON WILL SPREAD ACROSS THE REGION
TUESDAY NIGHT. PRECIPITATION MAY MOVE THROUGH THE AREA...ALTHOUGH
QPF EXPECTED TO BE QUITE LOW. MODELS APPEAR TO BE COMING MORE INTO
ALIGNMENT WITH THE UPCOMING WEATHER EVENT. MODELS ARE TRENDING
LESS AGGRESSIVE IN BRINGING IN ANY SORT OF BRIEF WINTRY MIX THAN
PREVIOUS RUNS. IN FACT...LATEST GFS AND NAM KEEP PRECIPITATION ALL
LIQUID FOR LATE TUESDAY NIGHT. NAM AND GFS BUFKIT INDICATING
RELATIVELY SHALLOW MOISTURE WELL BELOW THE SNOW GROWTH ZONE. BEST
SYNOPTIC LIFT WILL BE MAINLY OVER THE NC MOUNTAINS. POPS AND QPFS
REMAIN LOW. OVERNIGHT LOWS SHOULD DIP INTO THE LOWER TO MIDDLE
30S EARLY WEDNESDAY MORNING...BUT THE BULK OF THE MOISTURE WILL
HAVE MOVED EAST OF THE AREA BY THE TIME THE COLDEST TEMPERATURES
ARRIVE AROUND SUNRISE WEDNESDAY. HIGHS WEDNESDAY WILL RANGE FROM
THE MID 40S NORTH TO THE LOWER 50S SOUTH. WITH A DEVELOPING TIGHT
PRESSURE GRADIENT...IT WILL BECOME RATHER BREEZY TUESDAY NIGHT
INTO WEDNESDAY WITH SUSTAINED WIND SPEEDS OF 15 TO 25 MPH FROM THE
NORTH AND NORTHEAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WINDS WILL SUBSIDE BY LATE WEDNESDAY AS HIGH PRESSURE BUILDS IN
FROM THE WEST. HIGH PRESSURE EXPECTED TO CONTINUE INTO FRIDAY. THE
GFS AND ECMWF SHOW A DEVELOPING WARM FRONT WITH WEAK ISENTROPIC
LIFT SUPPORTING LOW CHANCE POPS SATURDAY AND SUNDAY.
TEMPERATURES BELOW NORMAL THROUGH FRIDAY...MUCH BELOW WEDNESDAY
AND THURSDAY. TEMPERATURES WILL MODERATE SATURDAY AND SUNDAY AHEAD
OF THE NEXT FRONTAL SYSTEM.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF PERIOD.
A DRY FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE REGION
OVERNIGHT/EARLY THIS MORNING. INFLUX OF DRIER AIR ALONG WITH SOME
WIND IS EXPECTED TO PRECLUDE FOG FORMATION. HIGH PRESSURE CENTER
WILL BUILD IN THIS AFTERNOON...LEADING TO DECREASING WIND SPEEDS.
EXTENDED AVIATION OUTLOOK...A COLD FRONT AND UPPER LEVEL TROUGH WILL
MOVE THROUGH THE REGION TUESDAY NIGHT INTO EARLY
WEDNESDAY...PROVIDING A SLIGHT CHANCE OF LIGHT PRECIPITATION...AND
ASSOCIATED RESTRICTIONS. BREEZY CONDITIONS WILL BE POSSIBLE AS WELL
TUE NT/WED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...LAKE WIND ADVISORY UNTIL 11 AM EST THIS MORNING FOR SCZ031-
036>038.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST MON NOV 11 2013
.DISCUSSION...
259 PM CST
SEVERAL NEAR TERM FORECAST CONCERNS AND CHALLENGES WITH
PRECIPITATION ENDING FROM NORTH TO SOUTH INTO THE EVENING...WITH
LAKE EFFECT SNOW DEVELOPING THROUGH THE EVENING IMPACTING PORTIONS
OF NORTHWEST INDIANA TO SOME DEGREE THROUGH THE OVERNIGHT. AFTERNOON
WATER VAPOR IMAGERY SHOWS A DEEP UPPER LOW SPINNING OVER SOUTHERN
JAMES BAY AS PART OF A BROAD UPPER TROUGH SPREADING ACROSS THE
EASTERN HALF OF THE COUNTRY. RIDGING IS BUILDING OVER THE PACIFIC
NORTHWEST AND BRITISH COLUMBIA AS ANOTHER UPPER LOW SPINS OVER THE
WEST COAST WITH YET ANOTHER TROUGH JUST TO ITS WEST. AT THE
SURFACE...LOW PRESSURE ASSOCIATED WITH THE JAMES BAY UPPER LOW IS
MOVING INTO NORTHERN QUEBEC WITH A COLD FRONT TRAILING IT TO THE
SOUTHWEST AND HAVING EXITED THE SOUTHERN CWA. STRONG HIGH PRESSURE
IS SETTLING SOUTHWARD INTO THE PLAINS AND WESTERN GREAT LAKES.
THIS EVENING...CURRENT POST FRONTAL BAND OF PRECIPITATION CONTINUES
TO GRADUALLY WORK SOUTHWARD ACROSS THE CENTRAL AND SOUTHERN CWA.
THIS BAND WILL CONTINUE SOUTHWARD THROUGH EARLY EVENING BEFORE
ENDING ACROSS THE SOUTHERN CWA BY MID EVENING OR SO. FAIRLY INTENSE
SNOWFALL PRODUCING VISIBILITY UNDER A MILE AT TIMES WILL CONTINUE AS
THE COLDER AIR SPREAD SOUTH...WITH AREAS THAT ARE CURRENTLY RAIN
CHANGING OVER. HAVE HAD REPORTS OF AROUND A HALF INCH OF
ACCUMULATION ON GRASSY AND OTHER NON PAVED SURFACES AND EXPECT THAT
THIS WILL CONTINUE TO BE THE TREND UNTIL THE SNOW WINDS DOWN. THE
MAIN CONCERN WITH THIS WILL BE TEMPS FALLING BELOW FREEZING ACROSS
AREAS THAT HAVE NOT ALREADY DONE SO THROUGH SUNSET. PRECIP MAY END
BEFORE THIS OCCURS IN SOME AREAS BUT THIS WILL SET UP POTENTIAL FOR
RESIDUAL MOISTURE ON VARIOUS SURFACES TO FREEZE BEFORE DRYING SO
MOTORISTS AND PEDESTRIANS SHOULD BE ALERT.
TONIGHT AND TUESDAY...THE FOCUS WILL BE ON LAKE EFFECT SNOW
PLACEMENT TONIGHT THROUGH TUESDAY MORNING. THE UPPER LOW WILL
CONTINUE EASTWARD TO THE GULF OF ST. LAWRENCE BY TUESDAY MORNING
WITH AN ASSOCIATED TROUGH AXIS CROSSING THE LOCAL AREA. NORTHERLY
LOW AND MID LEVEL FLOW WILL BE IN PLACE ACROSS LAKE MICHIGAN THIS
EVENING AND OVERNIGHT WITH CONTINUED COLD ADVECTION BRINGING H85
TEMPS DOWN TO AROUND -12 C CREATING LAKE TO H85 DELTA-TS OF 20+C.
GENERATING LAKE EFFECT WILL NOT BE A PROBLEM...ITS THE PLACEMENT
THAT IS THE MAIN CHALLENGE. MEAN LOW LEVEL FLOW THIS EVENING WILL
START OUT NORTHWESTERLY ACROSS NORTHERN PORTIONS OF THE LAKE AND
NORTHERLY SOUTH AS THE COLDER AIR CONTINUES TO ADVECT IN. WITH
TIME...THE MEAN FLOW WILL GAIN MORE OF A WEST COMPONENT/THOUGH STILL
REMAINING NORTHWESTERLY OVERALL/ INTO TUESDAY MORNING. THE INITIAL
CONVERGENCE LOOKS TO SET UP ACROSS NORTHERN SECTIONS OF THE LAKE
CLOSER TO THE MICHIGAN SHORE BASED ON THE NORTHWEST DIRECTION AND
FAIRLY STRONG SPEEDS FOCUSING FRICTIONAL CONVERGENCE CLOSER TO SHORE.
THE BAND MAY ARC SOUTH OR SOUTHWEST AS IT DEVELOPS SOUTHWARD AS THE
FLOW TURNS MORE NORTHERLY...BUT MAY STILL REMAIN FAIRLY CLOSE TO THE
MICHIGAN SHORELINE. AM CONCERNED BY THE NEARLY DUE NORTH DIRECTION
THIS EVENING BUT DEVELOPMENT OF MORE ORGANIZED BANDS MAY HOLD OFF
UNTIL CLOSER TO MIDNIGHT. THIS MAY RESULT IN PORTER COUNTY AND EVEN
PORTIONS OF JASPER COUNTY SEEING A PERIOD OF DECENT SNOWFALL LATER
THIS EVENING AND EARLY TONIGHT BEFORE WINDS TURN SLIGHTLY NORTHWEST
PUSHING THE BAND FURTHER EAST TOWARD DAYBREAK. MOST OF THE HIGH RES
GUIDANCE HAS BEEN BULLISH ON KEEPING THE BAND CLOSER TO THE MICHIGAN
SHORE AND INTO LAPORTE AND BERRIEN COUNTIES AND EVEN POINTS FURTHER
EAST...WITH MUCH LESS ACTIVITY IN PORTER/JASPER. AM WONDERING IF
THEY ARE A LITTLE TOO BULLISH ON HOW FAR EAST THE FOCUS BECOMES.
WITH A STRONG NORTH COMPONENT HAVE A HARD TIME SEEING THE BAND
DEVELOPING ALL THE WAY ON THE EAST SIDE OF THE LAKE AND MORE OR LESS
STAYING THERE UNLESS TIMING OF ACTUAL PLUME DEVELOPMENT IS DELAYED
UNTIL WINDS START TO TURN MORE NORTHWEST. INTERESTINGLY...SOME OF
THE LATEST RAP GUIDANCE FALLS MORE IN LINE WITH THIS THOUGHT
PROCESS. WHILE THERE IS SIGNIFICANT BUST POTENTIAL HERE...WILL GO
AHEAD AND ISSUE A LAKE EFFECT SNOW ADVISORY FOR PORTER AND JASPER
HIGHLIGHTING THE LATE EVENING AND OVERNIGHT HOURS AS THE PERIOD OF
BEST HEAVY SNOW POTENTIAL ACROSS MAINLY THE EAST HALF OF EACH
COUNTY. SNOWFALL RATES MAY BE QUITE INTENSE ON THE ORDER OF SEVERAL
INCHES PER HOUR BUT THE DURATION IS STILL A QUESTION MARK. COMBINE
THIS WITH GUSTY WINDS FAIRLY ROUGH CONDITIONS MAY DEVELOP ASSUMING
THE BAND AFFECTS THESE AREAS. STILL CANNOT RULE OUT WARNING LEVEL
SNOWS OVER 6 INCHES BUT WITH A FAIR AMOUNT OF SUPPORT FOR LESSER
AMOUNTS HAVE A HARD TIME GOING WITH A WARNING AT THIS POINT.
FOLLOWING THE IDEA THAT THE BAND WILL INITIALLY IMPACT PORTER/JASPER
THEN SHIFT EASTWARD FEEL A BIT MORE COMFORTABLE GOING WITH AN
ADVISORY THAN JUST KEEPING THE WATCH. THE EVENING SHIFT WILL NEED TO
MONITOR CLOSELY. BEYOND THAT...LOWS WILL FALL INTO THE LOW TO MID
20S TONIGHT WITH READINGS CLOSER TO 30 NEAR AND DOWNWIND OF THE
LAKE. DRY CONDITIONS WILL PERSIST ACROSS THE MAJORITY OF THE AREA
WITH LAKE EFFECT SHOWERS ENDING EAST TUESDAY. HIGHS WILL ONLY MAKE
IT INTO LOW TO MID 30S.
WEDNESDAY AND BEYOND...DID NOT HAVE A WHOLE LOT OF TIME TO LOOK
FURTHER AHEAD IN THE FORECAST PERIOD BUT HIGH PRESSURE WILL BE
SETTLING INTO THE LOWER OHIO VALLEY WEDNESDAY AS THE WESTERN UPPER
RIDGE IS SHUNTED EASTWARD. THIS WILL ALLOW MODEST WARM ADVECTION TO
DEVELOP IN THE MID LEVELS WITH A STEADY SOUTHWEST WIND AT THE
SURFACE AS THE HIGH SHIFTS EASTWARD. MAY BE A LITTLE TOO
CONSERVATIVE WITH UPPER 30S HIGHS WITH ANY SNOWPACK IN NW INDIANA
LIKELY KEEPING THINGS IN THE 30S REGARDLESS. THE UPPER RIDGE WILL BE
BROKEN DOWN AS IT TRANSLATES EASTWARD AS A FAIRLY BROAD LONGWAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS THURSDAY. A WEAK
SURFACE TROUGH IS EXPECTED TO ACCOMPANY THIS AND BRING A WEAK COOL
FRONT ACROSS THE AREA THURSDAY NIGHT OR FRIDAY WITH A LOW CHANCE FOR
RAIN/SNOW AT NIGHT AND SHOWERS DURING THE DAY. LOW AMPLITUDE FLOW WILL
THEN MOVE ACROSS THE AREA SATURDAY WITH AN AMPLIFYING TROUGH
SPREADING IN LATER IN THE WEEKEND AND EARLY NEXT WEEK. A SURFACE LOW
IS FORECAST TO DEEPEN AS THE TROUGH AMPLIFIES BUT ECMWF/GFS ARE AT
ODDS ON HOW QUICKLY THIS OCCURS. A WARMUP SHOULD OCCUR IN THE
SOUTHERLY FLOW AHEAD OF THE LOW BUT THIS MAY BE BRIEF IF A FASTER
SOLUTION PANS OUT. EITHER WAY MOIST SOUTHERLY FLOW POINTS TOWARD
INCREASING PRECIP CHANCES SUNDAY WHICH MAY CONTINUE THROUGH MONDAY
IF THE SLOWER SOLUTION PANS OUT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SNOW ENDING AROUND 23Z AT ORD...00Z AT MDW.
* IFR CIGS QUICKLY LIFTING THROUGH MVFR AFTER SNOW ENDS...WITH VFR
CIGS BY 2330Z AT ORD...0030Z AT MDW.
* STRONG/GUSTY NORTH/NORTHEAST WINDS SLOWLY TURNING BACK NORTH/
NORTHWEST BETWEEN 23Z-01Z.
* GUSTY NORTH/NORTHWEST WINDS THROUGH THE PERIOD. CMS
//DISCUSSION...UPDATED 22Z...
BACK EDGE OF THE SNOW IS STEADILY MOVING SOUTH ACROSS NORTHERN IL
WITH RAPID IMPROVEMENT AFTER THE SNOW ENDS. A LAKE ENHANCED
BOUNDARY MOVED THROUGH THE TERMINALS A FEW HOURS AGO SHIFTING
WINDS NORTH/NORTHEAST. WINDS STILL FROM 010 ON THE ONE MINUTE DATA
AT ORD/MDW. EXPECT WIND DIRECTIONS TO SLOWLY SHIFT BACK TO NORTH/
NORTHWEST AFTER THE SNOW ENDS. SOME POTENTIAL FOR WINDS TO REMAIN
GUSTY INTO THIS EVENING...BUT OBSERVATIONS ACROSS FAR NORTHERN IL
AND SOUTHERN WI SHOW GUSTS DIMINISHING...THUS GUSTS COULD BECOME
LESS PREVAILING INTO EARLY THIS EVENING. CMS
PREVIOUS 18Z DISCUSSION...
DETERIORATING CONDITIONS ONGOING ACROSS THE TERMINALS EARLY THIS
AFTERNOON...ESPECIALLY NEAR RFD WHERE THE RAIN/SNOW MIX QUICKLY
TRANSITIONED OVER TO ALL SNOW. THIS TREND WILL CONTINUE WITH THE
REMAINING TERMINALS OVER THE NEXT 1-2 HOURS...AND GYY BY THE 21Z
TIME FRAME. VISIBILITY OF 3-5 MILES IN THIS RAIN/SNOW MIX WILL
LIKELY BE OBSERVED BUT WITH VISIBILITY EXPECTED TO FALL TO 1-2
MILES IN THE SNOW. BRIEF BURSTS OF HEAVIER SNOW CANT BE RULED OUT
THIS AFTERNOON...BUT ONCE AGAIN PREVAILING VIS STAYING AROUND 1-2
MILES. THIS SNOW SHOULD TAPER OFF BY AROUND 23Z...BUT LINGER OVER
THE GYY TERMINAL INTO THE EVENING AS LAKE EFFECT SNOW SHOWERS
COULD COME RATHER CLOSE TO THE TERMINAL. ANY HEAVIER LAKE EFFECT
SNOW SHOWERS SHOULD REMAIN TO THE EAST OF GYY...BUT WILL NEED TO
CONTINUE TO MONITOR THE POSSIBILITY FOR A BRIEF/STRAY SNOW SHOWER
TO INCH CLOSE TO THE TERMINAL. CEILINGS HAVE BEEN RAPIDLY DROPPING
AT THIS HOUR AS WELL...WITH MVFR CEILINGS IN PLACE. DO EXPECT A
CONTINUED DOWNWARD TREND IN CEILINGS WILL IFR CEILINGS LIKELY
LATER THIS AFTERNOON. WITH THE DEPARTING PRECIP LATE THIS
AFTERNOON...EXPECT CEILINGS TO SLOWLY IMPROVE BUT THEN IMPROVE
SIGNIFICANTLY BY EARLY EVENING. NORTH NORTHWEST WINDS HAVE BEEN
SLOW TO INCREASE TODAY...BUT WITH INCREASED SPEEDS/GUSTS STILL
EXPECTED INTO THE AFTERNOON AND EARLY EVENING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH FOR SNOW/VIS/CIG AND IMPROVEMENT TRENDS LATE THIS AFTERNOON
AND EARLY THIS EVENING.
* MEDIUM FOR WIND SPEEDS/DIRECTIONS/GUSTS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR. JUST EAST OF TERMINALS MVFR CIGS AND
PSBL LAKE EFFECT CLOUDS.
WEDNESDAY THROUGH THURSDAY...VFR.
FRIDAY...MVFR POSSIBLE WITH CHC OF LIGHT RAIN/SNOW BEFORE
DAYBREAK. THEN CHC OF LIGHT RAIN AFT DAYBREAK.
SATURDAY...CHC OF RAIN AND MVFR CIGS.
SUNDAY...PSBL MVFR CIGS WITH CHC OF RAIN.
BEACHLER
&&
.MARINE...
338 PM CST
A COLD FRONT PUSHED DOWN THE LENGTH OF LAKE MI DURING LATE
OVERNIGHT AND THIS MORNING WITH WINDS SHIFTING TO OUT OF THE
NW AND N WITH 35 KT GALES. WINDS HAD FALLEN TO A BIT BELOW GALE
FORCE ON THE N AND CENTRAL PORTIONS OF THE LAKE AT MID
AFTERNOON...AND ARE EXPECTED TO DO SO ON THE S PORTION LATE THIS
AFTERNOON. HOWEVER...A SECOND SURGE OF COLD AIR MOVING ACROSS
NORTHERN WI AND THE U.P. OF MI WILL QUICKLY MOVE S DOWN THE LAKE
LATE THIS AFTERNOON AND EARLY THIS EVENING WITH WINDS EXPECTED TO
INCREASE BACK TO 35 KT GALES BEFORE GRADUALLY DIMINISHING
OVERNIGHT AND CONTINUING TO DO SO DURING TUESDAY. WINDS BACK TO
W TUE NIGHT AND SW WED...INCREASING TO 35-40 KT GALES AS A LARGE
HIGH MOVES EAST-SOUTHEAST FROM THE CENTRAL PLAINS ACROSS THE MID
MISSISSIPPI VALLEY AND REACHING THE SOUTHERN APPALACHIANS BY
THU. SW GALES WILL CONTINUE THROUGH WED NIGHT INTO THU MORNING
AS LOW PRESSURE THAT DEVELOPED OVER ALBERTA TUE DEEPENS AS IT
MOVES QUICKLY E TO JAMES BAY BY THU MORNING.
WINDS AND WAVES MEETING OR EXCEEDING OF SMALL CRAFT ADVISORY
CRITERIA WILL ALONG THE IL SHORE UNTIL LATE TUE EVENING...AND
INTO OVERNIGHT TUE. WINDS WILL LIKELY INCREASE BACK TO ABOVE
SMALL CRAFT CRITERIA BY WED AFTERNOON.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...LAKE EFFECT SNOW ADVISORY...INZ002-INZ011...9 PM MONDAY TO NOON
TUESDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 AM
TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN
UNTIL 9 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 AM TUESDAY TO 3 AM
WEDNESDAY.
&&
$$
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
400 PM CST MON NOV 11 2013
.DISCUSSION...
259 PM CST
SEVERAL NEAR TERM FORECAST CONCERNS AND CHALLENGES WITH
PRECIPITATION ENDING FROM NORTH TO SOUTH INTO THE EVENING...WITH
LAKE EFFECT SNOW DEVELOPING THROUGH THE EVENING IMPACTING PORTIONS
OF NORTHWEST INDIANA TO SOME DEGREE THROUGH THE OVERNIGHT. AFTERNOON
WATER VAPOR IMAGERY SHOWS A DEEP UPPER LOW SPINNING OVER SOUTHERN
JAMES BAY AS PART OF A BROAD UPPER TROUGH SPREADING ACROSS THE
EASTERN HALF OF THE COUNTRY. RIDGING IS BUILDING OVER THE PACIFIC
NORTHWEST AND BRITISH COLUMBIA AS ANOTHER UPPER LOW SPINS OVER THE
WEST COAST WITH YET ANOTHER TROUGH JUST TO ITS WEST. AT THE
SURFACE...LOW PRESSURE ASSOCIATED WITH THE JAMES BAY UPPER LOW IS
MOVING INTO NORTHERN QUEBEC WITH A COLD FRONT TRAILING IT TO THE
SOUTHWEST AND HAVING EXITED THE SOUTHERN CWA. STRONG HIGH PRESSURE
IS SETTLING SOUTHWARD INTO THE PLAINS AND WESTERN GREAT LAKES.
THIS EVENING...CURRENT POST FRONTAL BAND OF PRECIPITATION CONTINUES
TO GRADUALLY WORK SOUTHWARD ACROSS THE CENTRAL AND SOUTHERN CWA.
THIS BAND WILL CONTINUE SOUTHWARD THROUGH EARLY EVENING BEFORE
ENDING ACROSS THE SOUTHERN CWA BY MID EVENING OR SO. FAIRLY INTENSE
SNOWFALL PRODUCING VISIBILITY UNDER A MILE AT TIMES WILL CONTINUE AS
THE COLDER AIR SPREAD SOUTH...WITH AREAS THAT ARE CURRENTLY RAIN
CHANGING OVER. HAVE HAD REPORTS OF AROUND A HALF INCH OF
ACCUMULATION ON GRASSY AND OTHER NON PAVED SURFACES AND EXPECT THAT
THIS WILL CONTINUE TO BE THE TREND UNTIL THE SNOW WINDS DOWN. THE
MAIN CONCERN WITH THIS WILL BE TEMPS FALLING BELOW FREEZING ACROSS
AREAS THAT HAVE NOT ALREADY DONE SO THROUGH SUNSET. PRECIP MAY END
BEFORE THIS OCCURS IN SOME AREAS BUT THIS WILL SET UP POTENTIAL FOR
RESIDUAL MOISTURE ON VARIOUS SURFACES TO FREEZE BEFORE DRYING SO
MOTORISTS AND PEDESTRIANS SHOULD BE ALERT.
TONIGHT AND TUESDAY...THE FOCUS WILL BE ON LAKE EFFECT SNOW
PLACEMENT TONIGHT THROUGH TUESDAY MORNING. THE UPPER LOW WILL
CONTINUE EASTWARD TO THE GULF OF ST. LAWRENCE BY TUESDAY MORNING
WITH AN ASSOCIATED TROUGH AXIS CROSSING THE LOCAL AREA. NORTHERLY
LOW AND MID LEVEL FLOW WILL BE IN PLACE ACROSS LAKE MICHIGAN THIS
EVENING AND OVERNIGHT WITH CONTINUED COLD ADVECTION BRINGING H85
TEMPS DOWN TO AROUND -12 C CREATING LAKE TO H85 DELTA-TS OF 20+C.
GENERATING LAKE EFFECT WILL NOT BE A PROBLEM...ITS THE PLACEMENT
THAT IS THE MAIN CHALLENGE. MEAN LOW LEVEL FLOW THIS EVENING WILL
START OUT NORTHWESTERLY ACROSS NORTHERN PORTIONS OF THE LAKE AND
NORTHERLY SOUTH AS THE COLDER AIR CONTINUES TO ADVECT IN. WITH
TIME...THE MEAN FLOW WILL GAIN MORE OF A WEST COMPONENT/THOUGH STILL
REMAINING NORTHWESTERLY OVERALL/ INTO TUESDAY MORNING. THE INITIAL
CONVERGENCE LOOKS TO SET UP ACROSS NORTHERN SECTIONS OF THE LAKE
CLOSER TO THE MICHIGAN SHORE BASED ON THE NORTHWEST DIRECTION AND
FAIRLY STRONG SPEEDS FOCUSING FRICTIONAL CONVERGENCE CLOSER TO SHORE.
THE BAND MAY ARC SOUTH OR SOUTHWEST AS IT DEVELOPS SOUTHWARD AS THE
FLOW TURNS MORE NORTHERLY...BUT MAY STILL REMAIN FAIRLY CLOSE TO THE
MICHIGAN SHORELINE. AM CONCERNED BY THE NEARLY DUE NORTH DIRECTION
THIS EVENING BUT DEVELOPMENT OF MORE ORGANIZED BANDS MAY HOLD OFF
UNTIL CLOSER TO MIDNIGHT. THIS MAY RESULT IN PORTER COUNTY AND EVEN
PORTIONS OF JASPER COUNTY SEEING A PERIOD OF DECENT SNOWFALL LATER
THIS EVENING AND EARLY TONIGHT BEFORE WINDS TURN SLIGHTLY NORTHWEST
PUSHING THE BAND FURTHER EAST TOWARD DAYBREAK. MOST OF THE HIGH RES
GUIDANCE HAS BEEN BULLISH ON KEEPING THE BAND CLOSER TO THE MICHIGAN
SHORE AND INTO LAPORTE AND BERRIEN COUNTIES AND EVEN POINTS FURTHER
EAST...WITH MUCH LESS ACTIVITY IN PORTER/JASPER. AM WONDERING IF
THEY ARE A LITTLE TOO BULLISH ON HOW FAR EAST THE FOCUS BECOMES.
WITH A STRONG NORTH COMPONENT HAVE A HARD TIME SEEING THE BAND
DEVELOPING ALL THE WAY ON THE EAST SIDE OF THE LAKE AND MORE OR LESS
STAYING THERE UNLESS TIMING OF ACTUAL PLUME DEVELOPMENT IS DELAYED
UNTIL WINDS START TO TURN MORE NORTHWEST. INTERESTINGLY...SOME OF
THE LATEST RAP GUIDANCE FALLS MORE IN LINE WITH THIS THOUGHT
PROCESS. WHILE THERE IS SIGNIFICANT BUST POTENTIAL HERE...WILL GO
AHEAD AND ISSUE A LAKE EFFECT SNOW ADVISORY FOR PORTER AND JASPER
HIGHLIGHTING THE LATE EVENING AND OVERNIGHT HOURS AS THE PERIOD OF
BEST HEAVY SNOW POTENTIAL ACROSS MAINLY THE EAST HALF OF EACH
COUNTY. SNOWFALL RATES MAY BE QUITE INTENSE ON THE ORDER OF SEVERAL
INCHES PER HOUR BUT THE DURATION IS STILL A QUESTION MARK. COMBINE
THIS WITH GUSTY WINDS FAIRLY ROUGH CONDITIONS MAY DEVELOP ASSUMING
THE BAND AFFECTS THESE AREAS. STILL CANNOT RULE OUT WARNING LEVEL
SNOWS OVER 6 INCHES BUT WITH A FAIR AMOUNT OF SUPPORT FOR LESSER
AMOUNTS HAVE A HARD TIME GOING WITH A WARNING AT THIS POINT.
FOLLOWING THE IDEA THAT THE BAND WILL INITIALLY IMPACT PORTER/JASPER
THEN SHIFT EASTWARD FEEL A BIT MORE COMFORTABLE GOING WITH AN
ADVISORY THAN JUST KEEPING THE WATCH. THE EVENING SHIFT WILL NEED TO
MONITOR CLOSELY. BEYOND THAT...LOWS WILL FALL INTO THE LOW TO MID
20S TONIGHT WITH READINGS CLOSER TO 30 NEAR AND DOWNWIND OF THE
LAKE. DRY CONDITIONS WILL PERSIST ACROSS THE MAJORITY OF THE AREA
WITH LAKE EFFECT SHOWERS ENDING EAST TUESDAY. HIGHS WILL ONLY MAKE
IT INTO LOW TO MID 30S.
WEDNESDAY AND BEYOND...DID NOT HAVE A WHOLE LOT OF TIME TO LOOK
FURTHER AHEAD IN THE FORECAST PERIOD BUT HIGH PRESSURE WILL BE
SETTLING INTO THE LOWER OHIO VALLEY WEDNESDAY AS THE WESTERN UPPER
RIDGE IS SHUNTED EASTWARD. THIS WILL ALLOW MODEST WARM ADVECTION TO
DEVELOP IN THE MID LEVELS WITH A STEADY SOUTHWEST WIND AT THE
SURFACE AS THE HIGH SHIFTS EASTWARD. MAY BE A LITTLE TOO
CONSERVATIVE WITH UPPER 30S HIGHS WITH ANY SNOWPACK IN NW INDIANA
LIKELY KEEPING THINGS IN THE 30S REGARDLESS. THE UPPER RIDGE WILL BE
BROKEN DOWN AS IT TRANSLATES EASTWARD AS A FAIRLY BROAD LONGWAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS THURSDAY. A WEAK
SURFACE TROUGH IS EXPECTED TO ACCOMPANY THIS AND BRING A WEAK COOL
FRONT ACROSS THE AREA THURSDAY NIGHT OR FRIDAY WITH A LOW CHANCE FOR
RAIN/SNOW AT NIGHT AND SHOWERS DURING THE DAY. LOW AMPLITUDE FLOW WILL
THEN MOVE ACROSS THE AREA SATURDAY WITH AN AMPLIFYING TROUGH
SPREADING IN LATER IN THE WEEKEND AND EARLY NEXT WEEK. A SURFACE LOW
IS FORECAST TO DEEPEN AS THE TROUGH AMPLIFIES BUT ECMWF/GFS ARE AT
ODDS ON HOW QUICKLY THIS OCCURS. A WARMUP SHOULD OCCUR IN THE
SOUTHERLY FLOW AHEAD OF THE LOW BUT THIS MAY BE BRIEF IF A FASTER
SOLUTION PANS OUT. EITHER WAY MOIST SOUTHERLY FLOW POINTS TOWARD
INCREASING PRECIP CHANCES SUNDAY WHICH MAY CONTINUE THROUGH MONDAY
IF THE SLOWER SOLUTION PANS OUT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* RAIN/SNOW MIX QUICKLY TRANSITIONING OVER TO ALL SNOW OVER THE
NEXT HOUR...WITH VISIBILITY DROPPING TO AROUND 1 MILE AT TIMES.
* IFR CEILINGS THIS AFTERNOON.
* NNW WINDS INCREASING WITH GUSTS AROUND 20KT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
DETERIORATING CONDITIONS ONGOING ACROSS THE TERMINALS EARLY THIS
AFTERNOON...ESPECIALLY NEAR RFD WHERE THE RAIN/SNOW MIX QUICKLY
TRANSITIONED OVER TO ALL SNOW. THIS TREND WILL CONTINUE WITH THE
REMAINING TERMINALS OVER THE NEXT 1-2 HOURS...AND GYY BY THE 21Z
TIME FRAME. VISIBILITY OF 3-5 MILES IN THIS RAIN/SNOW MIX WILL
LIKELY BE OBSERVED BUT WITH VISIBILITY EXPECTED TO FALL TO 1-2
MILES IN THE SNOW. BRIEF BURSTS OF HEAVIER SNOW CANT BE RULED OUT
THIS AFTERNOON...BUT ONCE AGAIN PREVAILING VIS STAYING AROUND 1-2
MILES. THIS SNOW SHOULD TAPER OFF BY AROUND 23Z...BUT LINGER OVER
THE GYY TERMINAL INTO THE EVENING AS LAKE EFFECT SNOW SHOWERS
COULD COME RATHER CLOSE TO THE TERMINAL. ANY HEAVIER LAKE EFFECT
SNOW SHOWERS SHOULD REMAIN TO THE EAST OF GYY...BUT WILL NEED TO
CONTINUE TO MONITOR THE POSSIBILITY FOR A BRIEF/STRAY SNOW SHOWER
TO INCH CLOSE TO THE TERMINAL. CEILINGS HAVE BEEN RAPIDLY DROPPING
AT THIS HOUR AS WELL...WITH MVFR CEILINGS IN PLACE. DO EXPECT A
CONTINUED DOWNWARD TREND IN CEILINGS WILL IFR CEILINGS LIKELY
LATER THIS AFTERNOON. WITH THE DEPARTING PRECIP LATE THIS
AFTERNOON...EXPECT CEILINGS TO SLOWLY IMPROVE BUT THEN IMPROVE
SIGNIFICANTLY BY EARLY EVENING. NORTH NORTHWEST WINDS HAVE BEEN
SLOW TO INCREASE TODAY...BUT WITH INCREASED SPEEDS/GUSTS STILL
EXPECTED INTO THE AFTERNOON AND EARLY EVENING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM HIGH CONFIDENCE WITH PRECIP TRENDS/TIMING THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR. JUST EAST OF TERMINALS MVFR CIGS AND
PSBL LAKE EFFECT CLOUDS.
WEDNESDAY THROUGH THURSDAY...VFR.
FRIDAY...MVFR POSSIBLE WITH CHC OF LIGHT RAIN/SNOW BEFORE
DAYBREAK. THEN CHC OF LIGHT RAIN AFT DAYBREAK.
SATURDAY...CHC OF RAIN AND MVFR CIGS.
SUNDAY...PSBL MVFR CIGS WITH CHC OF RAIN.
BEACHLER
&&
.MARINE...
338 PM CST
A COLD FRONT PUSHED DOWN THE LENGTH OF LAKE MI DURING LATE
OVERNIGHT AND THIS MORNING WITH WINDS SHIFTING TO OUT OF THE
NW AND N WITH 35 KT GALES. WINDS HAD FALLEN TO A BIT BELOW GALE
FORCE ON THE N AND CENTRAL PORTIONS OF THE LAKE AT MID
AFTERNOON...AND ARE EXPECTED TO DO SO ON THE S PORTION LATE THIS
AFTERNOON. HOWEVER...A SECOND SURGE OF COLD AIR MOVING ACROSS
NORTHERN WI AND THE U.P. OF MI WILL QUICKLY MOVE S DOWN THE LAKE
LATE THIS AFTERNOON AND EARLY THIS EVENING WITH WINDS EXPECTED TO
INCREASE BACK TO 35 KT GALES BEFORE GRADUALLY DIMINISHING
OVERNIGHT AND CONTINUING TO DO SO DURING TUESDAY. WINDS BACK TO
W TUE NIGHT AND SW WED...INCREASING TO 35-40 KT GALES AS A LARGE
HIGH MOVES EAST-SOUTHEAST FROM THE CENTRAL PLAINS ACROSS THE MID
MISSISSIPPI VALLEY AND REACHING THE SOUTHERN APPALACHIANS BY
THU. SW GALES WILL CONTINUE THROUGH WED NIGHT INTO THU MORNING
AS LOW PRESSURE THAT DEVELOPED OVER ALBERTA TUE DEEPENS AS IT
MOVES QUICKLY E TO JAMES BAY BY THU MORNING.
WINDS AND WAVES MEETING OR EXCEEDING OF SMALL CRAFT ADVISORY
CRITERIA WILL ALONG THE IL SHORE UNTIL LATE TUE EVENING...AND
INTO OVERNIGHT TUE. WINDS WILL LIKELY INCREASE BACK TO ABOVE
SMALL CRAFT CRITERIA BY WED AFTERNOON.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...LAKE EFFECT SNOW ADVISORY...INZ002-INZ011...9 PM MONDAY TO NOON
TUESDAY.
LM...GALE WARNING...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ744-LMZ745-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 3 AM
TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 9 PM
TUESDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...3 AM TUESDAY TO 3 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
301 PM CST MON NOV 11 2013
.DISCUSSION...
ISSUED 300 PM CST MON NOV 11 2013
MUCH COLDER AIR WILL ARRIVE TONIGHT AND MODIFY ONLY SLIGHTLY
THROUGH WEDNESDAY MORNING. A WARMING TREND STILL LOOKS LIKELY
LATER THIS WEEK AS THE MID WEEK UPPER RIDGE SHIFTS EAST OF IL AND
A SOUTHWEST FLOW DEVELOPS ALOFT. THE WARMING WILL BECOME MORE
NOTICEABLE NEXT WEEKEND AS HIGHS RETURN TO THE 50S ON SATURDAY AND
AROUND 60 ON SUNDAY. RAINY CONDITIONS ARE FORECAST FOR AT LEAST
THE LAST HALF OF NEXT WEEKEND, AS A LONG WAVE TROUGH DIGS INTO THE
PLAINS. THE TIMING OF THAT SYSTEM IS STILL UNCERTAIN, BUT ANOTHER
COLD PUSH OF AIR IS PROJECTED BEHIND THAT UPPER TROUGH FOR EITHER
MONDAY (GFS) OR TUESDAY (ECMWF).
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE STRONG COLD FRONT WILL QUICKLY DEPART TO THE SOUTHEAST BY
EVENING, WITH POST-FRONTAL RAIN QUICKLY CHANGING TO SNOW. MOST
UPSTREAM REPORTS HAVE INDICATED THE SNOW MELTED AS IT FELL, BUT
SLIPPERY CONDITIONS DEVELOPED AS AIR TEMPS PLUMMETED BELOW
FREEZING. SOME ACCIDENTS HAVE BEEN REPORTED DUE TO ICY SPOTS ON
ROADS. THE BAND OF SNOW SEEMS TO BE EXPANDING IN DEPTH BETWEEN
19Z-20Z, AND THAT COULD KEEP SNOW FLYING FOR UP TO 4 HOURS OR SO
ONCE IT DEVELOPS. HOWEVER, MEASURABLE SNOW IS NOT REALLY EXPECTED
FOR MORE THAN A FEW MINUTES UNLESS A SNOW BURST OVERCOMES THE WARM
GROUND FOR A WHILE. VISIBILITIES HAVE DIPPED TO 1/4 MILE IN SNOW AT
TIMES UPSTREAM IN IOWA/WISCONSIN, MAINLY DUE TO WINDY CONDITIONS
DURING THE SNOWFALL AND NOT DUE TO THE HEAVY NATURE OF THE SNOWFALL.
THE MAIN AXIS OF PRECIPITATION SEEMS WELL CORRELATED TO THE 850MB
FRONTOGENESIS. RADAR IMAGES SHOW A MORE PRONOUNCED BAND OF
PRECIPITATION CORRELATING TO THE CHANGE-OVER TO SNOW, JUST
PASSING OVER DVN AT 20Z. LAPS SOUNDINGS SHOW THE CHANGE-OVER ALSO
CORRELATING TO A 925MB TEMP OF -2C. TIMING THOSE CONDITIONS AND
THAT BAND INTO OUR AREA WOULD PUT THE CHANGE TO SNOW IN GBG AROUND
330 PM, PIA AT 430 PM, BMI BY 515 PM, LINCOLN AT 6 PM, CMI/SPI AT
630 PM, EFFINGHAM AROUND 9 PM, AND LAWRENCEVILLE AROUND 1015 PM.
DEPENDING ON THE PROGRESSION OF 850MB FGEN, SNOW WILL GENERALLY
LAST FROM 2 TO 4 HOURS AFTER THOSE TIMES. AREAS SOUTHWEST OF A
LINE FROM RUSHVILLE TO EFFINGHAM WILL SEE WEAKER FORCING, BASED ON
THE LATEST RAP OUTPUT, SO PRECIP AMOUNTS SHOULD BE LOWER IN THOSE
AREAS.
SUBSIDENCE AND DRY AIR SHOULD HELP TO SHUT DOWN THE PRECIPTATION
IN OUR SOUTHEASTERN AREAS BETWEEN 2-3 AM. SKIES SHOULD BEGIN TO
CLEAR ABOUT 4 TO 5 HOURS AFTER THE PRECIPITATION ENDS, BASED ON
SATELLITE TRENDS AND FORECAST RH IN THE LOW TO MID LEVELS. LOWS
WILL HAVE A CHANCE TO DROP INTO THE UPPER TEENS W OF I-55, WITH
LOW TO MID 20S ELSEWHERE.
DRY AND UNSEASONABLY COLD AIR WILL LIMIT HIGHS ON TUESDAY TO THE
LOW 30S NEAR GBG AND UPPER 30S NEAR LWV. CLEAR SKIES AND LIGHT
WINDS UNDER THE SURFACE RIDGE AXIS ON TUESDAY NIGHT SHOULD ALLOW
ALL AREAS TO DROP INTO THE TEENS FOR LOWS. SOME WARMING IN THE
850MB LAYER SHOULD HELP TO TEMPER LOWS FROM DROPPING INTO THE
10-15 DEG RANGE. A COUPLE OF TRADITIONAL COLD SPOTS MAY END UP
THAT COLD.
WEDNESDAY WILL SEE THE SURFACE RIDGE SLIDE EAST OF IL AND RISING
HEIGHTS ALOFT AIDING IN WARMING THROUGH A DEEP COLUMN. THE AIR
TEMPS NEAR THE GROUND WILL BE SLOW TO REBOUND, BUT A STEADY RISE
BY 5 DEGREES FOR HIGHS IS EXPECTED WED AND THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY.
NORTHERN AND SOUTHERN STREAM JET INTERACTIONS WILL AID IN CARVING
A TROUGH IN THE ROCKIES AND WESTERN PLAINS ON THURSDAY. INCREASING
SOUTHWEST FLOW IN THE LEE OF THE TROUGH WILL PUSH MOISTURE AND CLOUDS
INTO ILLINOIS THURSDAY NIGHT. WE COULD SEE ENOUGH RISING MOTION
FROM WARM ADVECTION TO GENERATE A FEW RAIN SHOWERS WEST OF I-55.
CHANCE POPS WERE ONLY INCLUDED WEST OF RUSHVILLE TO LACON IN THE
NW. THE RAIN MAY CHANGE TO SNOW NORTH OF PEORIA LATE THUR NIGHT,
BUT PRECIP AMOUNTS WILL BE LIGHT AND NO ACCUMULATION IS EXPECTED.
A 500MB SHORTWAVE AND THE CORRESPONDING SURFACE TROUGH WILL PASS
ACROSS IL ON FRIDAY, WITH ADDITIONAL RAIN SHOWERS POSSIBLE. WE
ONLY USED SLIGHT CHANCE POPS FOR FRIDAY AS THE SYSTEM WILL BE
WEAKENING AS IT PUSHES INTO A RIDGE OVER THE EASTERN STATES.
THE UPPER TROUGH ACROSS THE WESTERN HALF OF THE LOWER 48 IS
EXPECTED TO AMPLIFY NEXT WEEKEND, INCREASING THE MOISTURE RETURN
INTO IL. A LOW LEVEL JET IS EXPECTED TO INTENSIFY BY SUNDAY
MORNING AND NOSE INTO IL, TRIGGERING MORE WIDESPREAD SHOWERS
STARTING AS EARLY AS SATURDAY NIGHT. SHOWERS MAY LINGER THROUGH
MONDAY PER THE GFS, OR THROUGH TUES IF THE SLOWER ECMWF VERIFIES.
SHIMON
&&
.AVIATION...
ISSUED 1120 AM CST MON NOV 11 2013
INITIAL WIND SHIFT ASSOCIATED WITH FRONTAL BOUNDARY JUST STARTING
TO COME THROUGH KBMI/KSPI, AND SHOULD GO THROUGH KDEC/KCMI OVER
THE NEXT COUPLE HOURS. WILL SEE NORTHWEST WINDS START TO PICK UP
SIGNIFICANTLY OVER THE NEXT FEW HOURS BEHIND THE FRONT, AS THE
COLDER AIR RUSHES INTO THE AREA, WITH GUSTS TO AROUND 25 KNOTS
LIKELY. LIGHT RAIN SHOULD START SPREADING IN FROM THE NORTH OVER
THE NEXT COUPLE HOURS. FORECAST SOUNDINGS START TO SUPPORT A
RAIN/SNOW MIX AROUND KPIA/KBMI BETWEEN 21-24Z AND FROM KSPI-KCMI
AROUND 00Z BEFORE SWITCHING OVER TO ALL SNOW. CEILINGS EXPECTED TO
DROP TO AROUND 1000-1500 FEET WITH THE PRECIPITATION, ALTHOUGH MAY
DIP BELOW 1000 FEET IN THE HEAVIER SNOW SHOWERS. THE GUSTY WINDS
WILL DIMINISH LATE EVENING, BUT GENERALLY REMAIN ABOVE 10 KNOTS
THE REMAINDER OF THE FORECAST PERIOD.
RATHER SHARP CLEARING LINE, CURRENTLY EVIDENT FROM NORTH DAKOTA TO
NORTHERN WISCONSIN, SHOULD COME THROUGH THE TAF SITES LATE THIS
EVENING, WITH MAINLY CLEAR SKIES INTO TUESDAY MORNING. HAVE KEPT
SOME CLOUDINESS CONTINUING LATER NEAR KCMI, WHICH WILL LIKELY BE
ON THE PERIPHERY OF LAKE EFFECT SNOWS THAT WILL AFFECT NORTHWEST
INDIANA.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...CORRECTED
NWS LINCOLN IL
305 PM CST MON NOV 11 2013
.DISCUSSION...
ISSUED 300 PM CST MON NOV 11 2013
MUCH COLDER AIR WILL ARRIVE TONIGHT AND MODIFY ONLY SLIGHTLY
THROUGH WEDNESDAY MORNING. A WARMING TREND STILL LOOKS LIKELY
LATER THIS WEEK AS THE MID WEEK UPPER RIDGE SHIFTS EAST OF IL AND
A SOUTHWEST FLOW DEVELOPS ALOFT. THE WARMING WILL BECOME MORE
NOTICEABLE NEXT WEEKEND AS HIGHS RETURN TO THE 50S ON SATURDAY AND
AROUND 60 ON SUNDAY. RAINY CONDITIONS ARE FORECAST FOR AT LEAST
THE LAST HALF OF NEXT WEEKEND, AS A LONG WAVE TROUGH DIGS INTO THE
PLAINS. THE TIMING OF THAT SYSTEM IS STILL UNCERTAIN, BUT ANOTHER
COLD PUSH OF AIR IS PROJECTED BEHIND THAT UPPER TROUGH FOR EITHER
MONDAY (GFS) OR TUESDAY (ECMWF).
SHORT TERM...TONIGHT THROUGH THURSDAY.
THE STRONG COLD FRONT WILL QUICKLY DEPART TO THE SOUTHEAST BY
EVENING, WITH POST-FRONTAL RAIN QUICKLY CHANGING TO SNOW. MOST
UPSTREAM REPORTS HAVE INDICATED THE SNOW MELTED AS IT FELL, BUT
SLIPPERY CONDITIONS DEVELOPED AS AIR TEMPS PLUMMETED BELOW
FREEZING. SOME ACCIDENTS HAVE BEEN REPORTED DUE TO ICY SPOTS ON
ROADS. THE BAND OF SNOW SEEMS TO BE EXPANDING IN DEPTH BETWEEN
19Z-20Z, AND THAT COULD KEEP SNOW FLYING FOR UP TO 4 HOURS OR SO
ONCE IT DEVELOPS. HOWEVER, MEASURABLE SNOW IS NOT REALLY EXPECTED
FOR MORE THAN A FEW MINUTES UNLESS A SNOW BURST OVERCOMES THE WARM
GROUND FOR A WHILE. VISIBILITIES HAVE DIPPED TO 1/4 MILE IN SNOW
AT TIMES UPSTREAM IN IOWA/WISCONSIN, MAINLY DUE TO WINDY
CONDITIONS DURING THE SNOWFALL AND NOT DUE TO THE HEAVY NATURE OF
THE SNOWFALL.
THE MAIN AXIS OF PRECIPITATION SEEMS WELL CORRELATED TO THE 850MB
FRONTOGENESIS. RADAR IMAGES SHOW A MORE PRONOUNCED BAND OF
PRECIPITATION CORRELATING TO THE CHANGE-OVER TO SNOW, JUST
PASSING OVER DVN AT 20Z. LAPS SOUNDINGS SHOW THE CHANGE-OVER ALSO
CORRELATING TO A 925MB TEMP OF -2C. TIMING THOSE CONDITIONS AND
THAT BAND INTO OUR AREA WOULD PUT THE CHANGE TO SNOW IN GBG AROUND
330 PM, PIA AT 430 PM, BMI BY 515 PM, LINCOLN AT 6 PM, CMI/SPI AT
630 PM, EFFINGHAM AROUND 9 PM, AND LAWRENCEVILLE AROUND 1015 PM.
DEPENDING ON THE PROGRESSION OF 850MB FGEN, SNOW WILL GENERALLY
LAST FROM 2 TO 4 HOURS AFTER THOSE CHANGE-OVER TIMES. AREAS
SOUTHWEST OF A LINE FROM RUSHVILLE TO EFFINGHAM WILL SEE WEAKER
FORCING, BASED ON THE LATEST RAP OUTPUT, SO PRECIP AMOUNTS SHOULD
BE LOWER IN THOSE AREAS.
SUBSIDENCE AND DRY AIR SHOULD HELP TO SHUT DOWN THE PRECIPTATION
IN OUR SOUTHEASTERN AREAS BETWEEN 2-3 AM. SKIES SHOULD BEGIN TO
CLEAR ABOUT 4 TO 5 HOURS AFTER THE PRECIPITATION ENDS, BASED ON
SATELLITE TRENDS AND FORECAST RH IN THE LOW TO MID LEVELS. LOW
TEMPS WILL HAVE A CHANCE TO DROP INTO THE UPPER TEENS W OF I-55,
WITH LOW TO MID 20S ELSEWHERE.
DRY AND UNSEASONABLY COLD AIR WILL LIMIT HIGHS ON TUESDAY TO THE
LOW 30S NEAR GBG AND UPPER 30S NEAR LWV. CLEAR SKIES AND LIGHT
WINDS UNDER THE SURFACE RIDGE AXIS ON TUESDAY NIGHT SHOULD ALLOW
ALL AREAS TO DROP INTO THE TEENS FOR LOWS. SOME WARMING IN THE
850MB LAYER SHOULD HELP TO TEMPER LOWS FROM DROPPING INTO THE
10-15 DEG RANGE. A COUPLE OF TRADITIONAL COLD SPOTS MAY END UP
THAT COLD.
WEDNESDAY WILL SEE THE SURFACE RIDGE SLIDE EAST OF IL AND RISING
HEIGHTS ALOFT AIDING IN WARMING THROUGH A DEEP COLUMN. THE AIR
TEMPS NEAR THE GROUND WILL BE SLOW TO REBOUND, BUT A STEADY RISE
BY 5 DEGREES FOR HIGHS IS EXPECTED WED AND THURSDAY.
LONG TERM...THURSDAY NIGHT THROUGH MONDAY.
NORTHERN AND SOUTHERN STREAM JET INTERACTIONS WILL AID IN CARVING
A TROUGH IN THE ROCKIES AND WESTERN PLAINS ON THURSDAY. INCREASING
SOUTHWEST FLOW IN THE LEE OF THE TROUGH WILL PUSH MOISTURE AND CLOUDS
INTO ILLINOIS THURSDAY NIGHT. WE COULD SEE ENOUGH RISING MOTION
FROM WARM ADVECTION TO GENERATE A FEW RAIN SHOWERS WEST OF I-55.
CHANCE POPS WERE ONLY INCLUDED WEST OF RUSHVILLE TO LACON IN THE
NW. THE RAIN MAY CHANGE TO SNOW NORTH OF PEORIA LATE THUR NIGHT,
BUT PRECIP AMOUNTS WILL BE LIGHT AND NO ACCUMULATION IS EXPECTED.
A 500MB SHORTWAVE AND THE CORRESPONDING SURFACE TROUGH WILL PASS
ACROSS IL ON FRIDAY, WITH ADDITIONAL RAIN SHOWERS POSSIBLE. WE
ONLY USED SLIGHT CHANCE POPS FOR FRIDAY AS THE SYSTEM WILL BE
WEAKENING AS IT PUSHES INTO A RIDGE OVER THE EASTERN STATES.
THE UPPER TROUGH ACROSS THE WESTERN HALF OF THE LOWER 48 IS
EXPECTED TO AMPLIFY NEXT WEEKEND, INCREASING THE MOISTURE RETURN
INTO IL. A LOW LEVEL JET IS EXPECTED TO INTENSIFY BY SUNDAY
MORNING AND NOSE INTO IL, TRIGGERING MORE WIDESPREAD SHOWERS
STARTING AS EARLY AS SATURDAY NIGHT. SHOWERS MAY LINGER THROUGH
MONDAY PER THE GFS, OR THROUGH TUES IF THE SLOWER ECMWF VERIFIES.
SHIMON
&&
.AVIATION...
ISSUED 1120 AM CST MON NOV 11 2013
INITIAL WIND SHIFT ASSOCIATED WITH FRONTAL BOUNDARY JUST STARTING
TO COME THROUGH KBMI/KSPI, AND SHOULD GO THROUGH KDEC/KCMI OVER
THE NEXT COUPLE HOURS. WILL SEE NORTHWEST WINDS START TO PICK UP
SIGNIFICANTLY OVER THE NEXT FEW HOURS BEHIND THE FRONT, AS THE
COLDER AIR RUSHES INTO THE AREA, WITH GUSTS TO AROUND 25 KNOTS
LIKELY. LIGHT RAIN SHOULD START SPREADING IN FROM THE NORTH OVER
THE NEXT COUPLE HOURS. FORECAST SOUNDINGS START TO SUPPORT A
RAIN/SNOW MIX AROUND KPIA/KBMI BETWEEN 21-24Z AND FROM KSPI-KCMI
AROUND 00Z BEFORE SWITCHING OVER TO ALL SNOW. CEILINGS EXPECTED TO
DROP TO AROUND 1000-1500 FEET WITH THE PRECIPITATION, ALTHOUGH MAY
DIP BELOW 1000 FEET IN THE HEAVIER SNOW SHOWERS. THE GUSTY WINDS
WILL DIMINISH LATE EVENING, BUT GENERALLY REMAIN ABOVE 10 KNOTS
THE REMAINDER OF THE FORECAST PERIOD.
RATHER SHARP CLEARING LINE, CURRENTLY EVIDENT FROM NORTH DAKOTA TO
NORTHERN WISCONSIN, SHOULD COME THROUGH THE TAF SITES LATE THIS
EVENING, WITH MAINLY CLEAR SKIES INTO TUESDAY MORNING. HAVE KEPT
SOME CLOUDINESS CONTINUING LATER NEAR KCMI, WHICH WILL LIKELY BE
ON THE PERIPHERY OF LAKE EFFECT SNOWS THAT WILL AFFECT NORTHWEST
INDIANA.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 PM CST MON NOV 11 2013
.DISCUSSION...
259 PM CST
SEVERAL NEAR TERM FORECAST CONCERNS AND CHALLENGES WITH
PRECIPITATION ENDING FROM NORTH TO SOUTH INTO THE EVENING...WITH
LAKE EFFECT SNOW DEVELOPING THROUGH THE EVENING IMPACTING PORTIONS
OF NORTHWEST INDIANA TO SOME DEGREE THROUGH THE OVERNIGHT. AFTERNOON
WATER VAPOR IMAGERY SHOWS A DEEP UPPER LOW SPINNING OVER SOUTHERN
JAMES BAY AS PART OF A BROAD UPPER TROUGH SPREADING ACROSS THE
EASTERN HALF OF THE COUNTRY. RIDGING IS BUILDING OVER THE PACIFIC
NORTHWEST AND BRITISH COLUMBIA AS ANOTHER UPPER LOW SPINS OVER THE
WEST COAST WITH YET ANOTHER TROUGH JUST TO ITS WEST. AT THE
SURFACE...LOW PRESSURE ASSOCIATED WITH THE JAMES BAY UPPER LOW IS
MOVING INTO NORTHERN QUEBEC WITH A COLD FRONT TRAILING IT TO THE
SOUTHWEST AND HAVING EXITED THE SOUTHERN CWA. STRONG HIGH PRESSURE
IS SETTLING SOUTHWARD INTO THE PLAINS AND WESTERN GREAT LAKES.
THIS EVENING...CURRENT POST FRONTAL BAND OF PRECIPITATION CONTINUES
TO GRADUALLY WORK SOUTHWARD ACROSS THE CENTRAL AND SOUTHERN CWA.
THIS BAND WILL CONTINUE SOUTHWARD THROUGH EARLY EVENING BEFORE
ENDING ACROSS THE SOUTHERN CWA BY MID EVENING OR SO. FAIRLY INTENSE
SNOWFALL PRODUCING VISIBILITY UNDER A MILE AT TIMES WILL CONTINUE AS
THE COLDER AIR SPREAD SOUTH...WITH AREAS THAT ARE CURRENTLY RAIN
CHANGING OVER. HAVE HAD REPORTS OF AROUND A HALF INCH OF
ACCUMULATION ON GRASSY AND OTHER NON PAVED SURFACES AND EXPECT THAT
THIS WILL CONTINUE TO BE THE TREND UNTIL THE SNOW WINDS DOWN. THE
MAIN CONCERN WITH THIS WILL BE TEMPS FALLING BELOW FREEZING ACROSS
AREAS THAT HAVE NOT ALREADY DONE SO THROUGH SUNSET. PRECIP MAY END
BEFORE THIS OCCURS IN SOME AREAS BUT THIS WILL SET UP POTENTIAL FOR
RESIDUAL MOISTURE ON VARIOUS SURFACES TO FREEZE BEFORE DRYING SO
MOTORISTS AND PEDESTRIANS SHOULD BE ALERT.
TONIGHT AND TUESDAY...THE FOCUS WILL BE ON LAKE EFFECT SNOW
PLACEMENT TONIGHT THROUGH TUESDAY MORNING. THE UPPER LOW WILL
CONTINUE EASTWARD TO THE GULF OF ST. LAWRENCE BY TUESDAY MORNING
WITH AN ASSOCIATED TROUGH AXIS CROSSING THE LOCAL AREA. NORTHERLY
LOW AND MID LEVEL FLOW WILL BE IN PLACE ACROSS LAKE MICHIGAN THIS
EVENING AND OVERNIGHT WITH CONTINUED COLD ADVECTION BRINGING H85
TEMPS DOWN TO AROUND -12 C CREATING LAKE TO H85 DELTA-TS OF 20+C.
GENERATING LAKE EFFECT WILL NOT BE A PROBLEM...ITS THE PLACEMENT
THAT IS THE MAIN CHALLENGE. MEAN LOW LEVEL FLOW THIS EVENING WILL
START OUT NORTHWESTERLY ACROSS NORTHERN PORTIONS OF THE LAKE AND
NORTHERLY SOUTH AS THE COLDER AIR CONTINUES TO ADVECT IN. WITH
TIME...THE MEAN FLOW WILL GAIN MORE OF A WEST COMPONENT/THOUGH STILL
REMAINING NORTHWESTERLY OVERALL/ INTO TUESDAY MORNING. THE INITIAL
CONVERGENCE LOOKS TO SET UP ACROSS NORTHERN SECTIONS OF THE LAKE
CLOSER TO THE MICHIGAN SHORE BASED ON THE NORTHWEST DIRECTION AND
FAIRLY STRONG SPEEDS FOCUSING FRICTIONAL CONVERGENCE CLOSER TO SHORE.
THE BAND MAY ARC SOUTH OR SOUTHWEST AS IT DEVELOPS SOUTHWARD AS THE
FLOW TURNS MORE NORTHERLY...BUT MAY STILL REMAIN FAIRLY CLOSE TO THE
MICHIGAN SHORELINE. AM CONCERNED BY THE NEARLY DUE NORTH DIRECTION
THIS EVENING BUT DEVELOPMENT OF MORE ORGANIZED BANDS MAY HOLD OFF
UNTIL CLOSER TO MIDNIGHT. THIS MAY RESULT IN PORTER COUNTY AND EVEN
PORTIONS OF JASPER COUNTY SEEING A PERIOD OF DECENT SNOWFALL LATER
THIS EVENING AND EARLY TONIGHT BEFORE WINDS TURN SLIGHTLY NORTHWEST
PUSHING THE BAND FURTHER EAST TOWARD DAYBREAK. MOST OF THE HIGH RES
GUIDANCE HAS BEEN BULLISH ON KEEPING THE BAND CLOSER TO THE MICHIGAN
SHORE AND INTO LAPORTE AND BERRIEN COUNTIES AND EVEN POINTS FURTHER
EAST...WITH MUCH LESS ACTIVITY IN PORTER/JASPER. AM WONDERING IF
THEY ARE A LITTLE TOO BULLISH ON HOW FAR EAST THE FOCUS BECOMES.
WITH A STRONG NORTH COMPONENT HAVE A HARD TIME SEEING THE BAND
DEVELOPING ALL THE WAY ON THE EAST SIDE OF THE LAKE AND MORE OR LESS
STAYING THERE UNLESS TIMING OF ACTUAL PLUME DEVELOPMENT IS DELAYED
UNTIL WINDS START TO TURN MORE NORTHWEST. INTERESTINGLY...SOME OF
THE LATEST RAP GUIDANCE FALLS MORE IN LINE WITH THIS THOUGHT
PROCESS. WHILE THERE IS SIGNIFICANT BUST POTENTIAL HERE...WILL GO
AHEAD AND ISSUE A LAKE EFFECT SNOW ADVISORY FOR PORTER AND JASPER
HIGHLIGHTING THE LATE EVENING AND OVERNIGHT HOURS AS THE PERIOD OF
BEST HEAVY SNOW POTENTIAL ACROSS MAINLY THE EAST HALF OF EACH
COUNTY. SNOWFALL RATES MAY BE QUITE INTENSE ON THE ORDER OF SEVERAL
INCHES PER HOUR BUT THE DURATION IS STILL A QUESTION MARK. COMBINE
THIS WITH GUSTY WINDS FAIRLY ROUGH CONDITIONS MAY DEVELOP ASSUMING
THE BAND AFFECTS THESE AREAS. STILL CANNOT RULE OUT WARNING LEVEL
SNOWS OVER 6 INCHES BUT WITH A FAIR AMOUNT OF SUPPORT FOR LESSER
AMOUNTS HAVE A HARD TIME GOING WITH A WARNING AT THIS POINT.
FOLLOWING THE IDEA THAT THE BAND WILL INITIALLY IMPACT PORTER/JASPER
THEN SHIFT EASTWARD FEEL A BIT MORE COMFORTABLE GOING WITH AN
ADVISORY THAN JUST KEEPING THE WATCH. THE EVENING SHIFT WILL NEED TO
MONITOR CLOSELY. BEYOND THAT...LOWS WILL FALL INTO THE LOW TO MID
20S TONIGHT WITH READINGS CLOSER TO 30 NEAR AND DOWNWIND OF THE
LAKE. DRY CONDITIONS WILL PERSIST ACROSS THE MAJORITY OF THE AREA
WITH LAKE EFFECT SHOWERS ENDING EAST TUESDAY. HIGHS WILL ONLY MAKE
IT INTO LOW TO MID 30S.
WEDNESDAY AND BEYOND...DID NOT HAVE A WHOLE LOT OF TIME TO LOOK
FURTHER AHEAD IN THE FORECAST PERIOD BUT HIGH PRESSURE WILL BE
SETTLING INTO THE LOWER OHIO VALLEY WEDNESDAY AS THE WESTERN UPPER
RIDGE IS SHUNTED EASTWARD. THIS WILL ALLOW MODEST WARM ADVECTION TO
DEVELOP IN THE MID LEVELS WITH A STEADY SOUTHWEST WIND AT THE
SURFACE AS THE HIGH SHIFTS EASTWARD. MAY BE A LITTLE TOO
CONSERVATIVE WITH UPPER 30S HIGHS WITH ANY SNOWPACK IN NW INDIANA
LIKELY KEEPING THINGS IN THE 30S REGARDLESS. THE UPPER RIDGE WILL BE
BROKEN DOWN AS IT TRANSLATES EASTWARD AS A FAIRLY BROAD LONGWAVE
TROUGH MOVES ACROSS THE ROCKIES AND INTO THE PLAINS THURSDAY. A WEAK
SURFACE TROUGH IS EXPECTED TO ACCOMPANY THIS AND BRING A WEAK COOL
FRONT ACROSS THE AREA THURSDAY NIGHT OR FRIDAY WITH A LOW CHANCE FOR
RAIN/SNOW AT NIGHT AND SHOWERS DURING THE DAY. LOW AMPLITUDE FLOW WILL
THEN MOVE ACROSS THE AREA SATURDAY WITH AN AMPLIFYING TROUGH
SPREADING IN LATER IN THE WEEKEND AND EARLY NEXT WEEK. A SURFACE LOW
IS FORECAST TO DEEPEN AS THE TROUGH AMPLIFIES BUT ECMWF/GFS ARE AT
ODDS ON HOW QUICKLY THIS OCCURS. A WARMUP SHOULD OCCUR IN THE
SOUTHERLY FLOW AHEAD OF THE LOW BUT THIS MAY BE BRIEF IF A FASTER
SOLUTION PANS OUT. EITHER WAY MOIST SOUTHERLY FLOW POINTS TOWARD
INCREASING PRECIP CHANCES SUNDAY WHICH MAY CONTINUE THROUGH MONDAY
IF THE SLOWER SOLUTION PANS OUT.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* RAIN/SNOW MIX QUICKLY TRANSITIONING OVER TO ALL SNOW OVER THE
NEXT HOUR...WITH VISIBILITY DROPPING TO AROUND 1 MILE AT TIMES.
* IFR CEILINGS THIS AFTERNOON.
* NNW WINDS INCREASING WITH GUSTS AROUND 20KT.
RODRIGUEZ
//DISCUSSION...UPDATED 18Z...
DETERIORATING CONDITIONS ONGOING ACROSS THE TERMINALS EARLY THIS
AFTERNOON...ESPECIALLY NEAR RFD WHERE THE RAIN/SNOW MIX QUICKLY
TRANSITIONED OVER TO ALL SNOW. THIS TREND WILL CONTINUE WITH THE
REMAINING TERMINALS OVER THE NEXT 1-2 HOURS...AND GYY BY THE 21Z
TIME FRAME. VISIBILITY OF 3-5 MILES IN THIS RAIN/SNOW MIX WILL
LIKELY BE OBSERVED BUT WITH VISIBILITY EXPECTED TO FALL TO 1-2
MILES IN THE SNOW. BRIEF BURSTS OF HEAVIER SNOW CANT BE RULED OUT
THIS AFTERNOON...BUT ONCE AGAIN PREVAILING VIS STAYING AROUND 1-2
MILES. THIS SNOW SHOULD TAPER OFF BY AROUND 23Z...BUT LINGER OVER
THE GYY TERMINAL INTO THE EVENING AS LAKE EFFECT SNOW SHOWERS
COULD COME RATHER CLOSE TO THE TERMINAL. ANY HEAVIER LAKE EFFECT
SNOW SHOWERS SHOULD REMAIN TO THE EAST OF GYY...BUT WILL NEED TO
CONTINUE TO MONITOR THE POSSIBILITY FOR A BRIEF/STRAY SNOW SHOWER
TO INCH CLOSE TO THE TERMINAL. CEILINGS HAVE BEEN RAPIDLY DROPPING
AT THIS HOUR AS WELL...WITH MVFR CEILINGS IN PLACE. DO EXPECT A
CONTINUED DOWNWARD TREND IN CEILINGS WILL IFR CEILINGS LIKELY
LATER THIS AFTERNOON. WITH THE DEPARTING PRECIP LATE THIS
AFTERNOON...EXPECT CEILINGS TO SLOWLY IMPROVE BUT THEN IMPROVE
SIGNIFICANTLY BY EARLY EVENING. NORTH NORTHWEST WINDS HAVE BEEN
SLOW TO INCREASE TODAY...BUT WITH INCREASED SPEEDS/GUSTS STILL
EXPECTED INTO THE AFTERNOON AND EARLY EVENING.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM HIGH CONFIDENCE WITH PRECIP TRENDS/TIMING THIS AFTERNOON.
* MEDIUM HIGH CONFIDENCE WITH CEILING TRENDS.
* HIGH CONFIDENCE WITH WIND SPEED AND DIRECTION.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...MAINLY VFR. JUST EAST OF TERMINALS MVFR CIGS AND
PSBL LAKE EFFECT CLOUDS.
WEDNESDAY THROUGH THURSDAY...VFR.
FRIDAY...MVFR POSSIBLE WITH CHC OF LIGHT RAIN/SNOW BEFORE
DAYBREAK. THEN CHC OF LIGHT RAIN AFT DAYBREAK.
SATURDAY...CHC OF RAIN AND MVFR CIGS.
SUNDAY...PSBL MVFR CIGS WITH CHC OF RAIN.
BEACHLER
&&
.MARINE...
201 AM CST
MARINE CONCERNS...
GALES DEVELOPING THIS MORNING ACROSS THE NORTHERN HALF OF THE
LAKE...THEN OVERSPREADING THE REMAINDER OF THE LAKE.
FOR MOST OF THE ILLINOIS AND FAR WESTERN INDIANA NEARSHORE WATERS
WINDS SHOULD REMAIN UNDER GALES...WHILE EAST OF GARY GALES WILL
DEVELOP LATER TODAY.
GALES COME TO AN END MID-MORNING TUE...ALTHOUGH FOR THE NEARSHORE
WATERS HAZARDOUS WAVES WILL LIKELY PERSIST INTO TUE EVENING WITH
THE VERY COLD AIR SLIDING ACROSS THE LAKE AND PERSISTING NORTHWEST
WINDS.
STRONG COLD FRONT WILL SLIDE SOUTHEAST ACROSS THE LAKE THIS
MORNING...WITH WINDS QUICKLY FLIPPING FROM SOUTHWEST TO NORTHWEST
THEN NORTH BEHIND THE FRONT. IN ADDITION A VERY TIGHT PRESSURE
GRADIENT WILL BE ASSOCIATED WITH THE BOUNDARY...RESULTING IN GALES
TO 40 KT. COULD SEE ACROSS THE NORTHERN HALF OF THE LAKE A PERIOD
OF GALES TO 45 KT THIS AFTN. FURTHER SOUTH THE GRADIENT IS
SLIGHTLY LESS THIS AFTN/EVE...SO HAVE GALES BETWEEN 35-40KT.
STRONG CANADIAN HIGH PRESSURE SLIDES SOUTH INTO THE CENTRAL PLAINS
TONIGHT...WHICH WILL MAINTAIN THE NORTH FLOW ACROSS THE LAKE
TONIGHT INTO TUESDAY. THEN HIGH PRESSURE BEGINS TO PROVIDE AN
INFLUENCE ON THE GRADIENT AND ALLOWS THE WINDS TO DIMINISH.
HIGH PRESSURE THEN DRIFTS SOUTHEAST OF THE GREAT LAKES...WITH FLOW
TURNING WEST THEN SOUTHWESTERLY WED. ANOTHER TROUGH OF LOW
PRESSURE IS FORECAST TO DEVELOP OVER THE UPPER MIDWEST...WHICH
WILL LIKELY RESULT IN A TIGHTENING GRADIENT AND GALES FOR THE OPEN
WATERS WED NIGHT INTO THUR.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...LAKE EFFECT SNOW WATCH...INZ002...9 PM MONDAY TO 6 PM TUESDAY.
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 AM TUESDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 9 PM
TUESDAY.
GALE WARNING...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 10 PM MONDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...10 PM MONDAY TO 3 AM
WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 PM EST TUE NOV 12 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE FROM AZ/UT TO SASK AND A TROUGH OVER THE ERN
CONUS RESULTING IN NRLY FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WINDS WERE BACKING WRLY OVER UPPER MI AS THE LARGE HIGH PRES
SETTLES THROUGH ERN KS. LES INTO THE NE PORTION OF THE CWA
WAS QUICKLY DIMINISHING AS WINDS SHIFTED TO THE WEST AND VERY DRY
AIR WITH LOWERING INVERSION HEIGHTS MOVE ACROSS LAKE SUPERIOR.
TONIGHT...ANY LINGERING LES WILL END BY LATE THIS EVENING AS WINDS
BECOME OFFSHORE. RADIATIONAL COOLING WILL HELP TEMPS DROP INTO THE
TEENS OVER INLAND LOCATIONS. HOWEVER...INCREASING MID HIGH CLOUDS
SUPPORTED BY WAA WITH 300K-305K ISENTROPIC LIFT SPREADING ACROSS
UPPER MI AND INCREASING SW WINDS WILL LIMIT COOLING OVERNIGHT.
WED...THE PRES GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN THE HIGH
SINKING INTO THE SRN CONUS AND LOW PRES MOVING TOWARD JAMES BAY.
HOWVER...STRONG 925-850 MB WAA WILL INCREASE STABILITY ENOUGH TO
LIMIT SFC WIND GUSTS. NAM BUFKIT MOMENTUM TRANSFER SUGGESTS WINDS
COULD STILL GUST INTO THE 25-30 KT RANGE OVER MUCH OF THE CWA. THE
STABILITY AND INCREASING STRONG/LOW INVERSION HEIGHT WILL KEEP TEMPS
IN THE UPPER 30S AND LOWER 40S EVEN AS 925/850 MB TEMPS CLIMB INTO
THE 8C-10C RANGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
UPPER RIDGE OVER THE AREA ON WEDNESDAY WILL FLATTEN AND SHIFT EAST
AS A SHORTWAVE DIVES EAST-SOUTHEAST ACROSS CENTRAL CANADA. A LOW
ASSOCIATED WITH THIS WAVE WILL BE OVER JAMES BAY AT THE START OF THE
PERIOD AND THEN SHIFT EAST ACROSS QUEBEC ON THURSDAY. AS THIS
OCCURS...IT WILL SLOWLY DRAG A COLD FRONT ACROSS UPPER MICHIGAN
WEDNESDAY NIGHT AND THURSDAY. MOISTURE (DRY AIR BETWEEN 850-700MB)
AND FORCING STILL LOOK TO BE VERY LIMITED WEDNESDAY NIGHT AND INTO
MUCH OF THURSDAY. BUT AS A SECONDARY SHORTWAVE MOVES OUT OF THE
NORTHERN PLAINS ON THURSDAY AFTERNOON AND NIGHT (AND PROVIDES
ADDITIONAL MOISTURE)...THINK THERE SHOULD BE SOME EXPANSION OF THE
SHOWERS OVER THE AREA. THE TRACK OF THE SHORTWAVE AND SUBSEQUENT
WEAK LOW DEVELOPMENT WILL DETERMINE THE LOCATION OF THE
SHOWERS...BUT MOST OF THE MODELS INDICATE THE TRACK BEING ACROSS THE
NORTHERN HALF OF UPPER MICHIGAN OR LAKE SUPERIOR. WILL HAVE THE
HIGHEST POPS FOR THAT AREA. THERE AREA ALSO DIFFERENCES ON THE
AMOUNT OF COLD AIR AVAILABLE WITH THE WESTERLY WINDS ACROSS LAKE
SUPERIOR...SO NOT OVERLY CONFIDENT ON THE POTENTIAL FOR LAKE
ENHANCEMENT FOR THE KEWEENAW ON FRIDAY...BUT FEEL HAVING CHANCE POPS
IS REASONABLE. HAVE KEPT P-TYPE MAINLY RAIN THROUGH THAT
PERIOD...FIRST DUE TO THE WARM LAYER AROUND 850MB WED NIGHT INTO
THURSDAY AND THEN DUE TO QUESTIONS ON AMOUNT OF COLD AIR AND ICE
PRESENT IN THE CLOUDS FOR THURS NIGHT INTO FRIDAY. HIGHS LOOK TO BE
AROUND 40 DURING THAT PERIOD AND LOWS AROUND 30.
WILL DEFINITELY NEED TO KEEP AN EYE ON THE FORECAST FOR THE END OF
THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A STRONG SHORTWAVE
DIVING SOUTH FROM ALASKA WILL AMPLIFY THE POLAR JET OVER THE
ROCKIES AT THE START OF THE WEEKEND. BROAD SOUTHWESTERLY FLOW AHEAD
OF THIS AMPLIFYING TROUGH WILL LIKELY LEAD TO A PERIOD OF RAIN
LATER SATURDAY INTO SUNDAY UNDER THE WARM AIR ADVECTION AHEAD OF A
SURFACE TROUGH STRETCHING FROM THE NORTHERN PLAINS TO HUDSON BAY.
THEN...AS THE SHORTWAVE ROUNDS THE TROUGH AND EJECTS INTO THE GREAT
LAKES REGION SUNDAY NIGHT INTO MONDAY...IT APPEARS THAT THE REGION
WILL SEE A LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. AT THIS FAR
OUT...THERE IS STILL A LOT OF UNCERTAINTY...BUT THE POTENTIAL IS
THERE AT THIS POINT FOR MEASURABLE SNOW OVER THE WESTERN HALF OF
UPPER MICHIGAN. COLDER AIR MOVING IN BEHIND THE LOW FOR TUESDAY
(AROUND -15C AT 850MB) WOULD SUPPORT LAKE EFFECT SNOW IN THE
NORTHWEST WIND BELTS AND DID TREND POPS UP SOME FOR THE FAVORED
LOCATIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 636 PM EST TUE NOV 12 2013
WITH DRY AIR MASS DOMINATING...VFR CONDITIONS WILL BE THE RULE AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD. AS PRES GRADIENT TIGHTENS...
WINDS WILL STRENGTHEN ABOVE SFC BASED INVERSION...RESULTING IN LLWS
AT KIWD AND KSAW TONIGHT. GUSTY WRLY WINDS WILL CONTINUE AT KCMX.
GUSTY WINDS TO 25-30KT ARE EXPECTED AT ALL TERMINALS WED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST TUE NOV 12 2013
EXPECT GALE FORCE WINDS FROM LATE WED MORNING THROUGH WED EVENING
OVER WRN LAKE SUPERIOR AS A STRONG HIGH PRESSURE SYSTEM TO THE SOUTH
CREATES A TIGHT PRESSURE GRADIENT WITH A TROUGH PASSING BY TO THE
NORTH IN ONTARIO. WINDS NEAR GALE STRENGTH ARE ALSO POSSIBLE OVER
CNTRL LAKE SUPERIOR BUT SHOULD DIMINISH OVERNIGHT AS THE GRADIENT
WEAKENS. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 9 AM TO 11 PM EST WEDNESDAY FOR LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1246 PM EST MON NOV 11 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 343 AM EST MON NOV 11 2013
MUCH COLDER AIR WILL BE PUSHING INTO THE REGION TODAY AS A COLD
FRONT MOVES THROUGH. RAIN IS EXPECTED THIS MORNING...WHICH WILL
CHANGE OVER TO SNOW FROM NORTH TO SOUTH THIS AFTERNOON. MOST AREAS
WILL SEE LITTLE OR NO SNOW ACCUMULATION...BUT AREAS NEAR HIGHWAY 10
COULD SEE AN INCH OR TWO BY THIS AFTERNOON. TEMPERATURES WILL FALL
THROUGH THE 30S THIS AFTERNOON AND INTO THE 20S TONIGHT.
LAKE EFFECT SNOW WILL INCREASE INTO TONIGHT AND ADDITIONAL SNOW
ACCUMULATIONS ARE LIKELY MAINLY WEST OF U.S. 131. ONE TO LOCALLY
FOUR INCHES WILL BE POSSIBLE TONIGHT THROUGH NOON TUESDAY.
QUIETER WEATHER IS EXPECTED BY MID WEEK AND TOWARD THE WEEKEND.
TEMPERATES WILL WARM TO MAINLY 45 TO 50.
&&
.UPDATE...
ISSUED AT 1115 AM EST MON NOV 11 2013
SO FAR (11 AM) THE FORECAST IS ON TRACK. THE RAIN TO SNOW LINE IS
JUST BEHIND THE COLD FRONT BUT THE BELOW FREEZING TEMPERATURES
REMAIN NORTH OF ROUTE 10 YET. THE RAIN TO SNOW LINE IS NEAR ROUTE
20. I EXPECT THE THE MAIN AREA OF RAIN ASSOCIATED WITH RR QUAD OF
TO CONTINUE PROGRESS SOUTH WITH TIME. THE BACK EDGE OF THE
PRECIPITATION SHOULD BE MOVING SOUTH THROUGH THE CWA AFTER 2 PM
AND REACH THE I-96 AREA BY 4 PM AND I-96 BY 6 PM.
AS FOR THE SNOW...THE RAIN/SNOW LINE SHOULD REACH THE GRR AREA
BETWEEN 2 PM AND 3 PM... SO MAYBE AN HOUR OR TWO OF WET SNOW
BEFORE IT END. I DO NOT SEE MUCH ACCUMULATION OUTSIDE OUR ADVISORY
AREA. UP THERE...SINCE UP TO 3 INCHES HAS ALREADY FALLEN... AND
THERE SEEMS TO BE A LAKE ENHANCED AREA OF SNOW MOVING SOUTH OVER
NORTHERN LOWER MICHIGAN...THEY COULD SEE ANOTHER 1 TO 2 INCHES
BRINGING THE STORM TOTAL TO 5 INCHES.
I MAY NEED SOME SORT OF LAKE EFFECT SNOW ADVISORY FOR VAN BUREN
AND POSSIBLY EXTREME WESTERN ALLEGAN COUNTY AS LATE MODEL RUNS
SUGGEST THE SNOW BAND MAY MOVE ON SHORE OVERNIGHT. ALSO THE SNOW
BAND OFF LAKE SUPERIOR IS SHOWN BY SEVERAL HIGH RES MODELS TO
REACH WELL INTO OUR NORTHERN CWA NEAR US-131 SO I MAY NEED AN
ADVISORY UP THERE TOO FOR THE AFTERNOON FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
A COLD FRONT WAS PUSHING SOUTHEAST ACROSS THE GREEN BAY REGION EARLY
THIS MORNING. IT WILL SLIDE ACROSS THE GRR CWA BETWEEN 12Z AND
18Z. TEMPS WILL BE WARM ENOUGH FOR ALL RAIN AHEAD OF THE
FRONT...THEN AN HOUR OR TWO AFTER IT PASSES WE SHOULD WET BULB DOWN
TO SWITCH OVER THE ALL SNOW.
HAVE DECIDED TO POST A WINTER WEATHER ADVISORY FOR LAKE...OSCEOLA
AND CLARE COUNTIES. SNOWFALL RATES LATER THIS MORNING INTO EARLY
THIS AFTERNOON COULD PRODUCE SLUSHY/SNOW COVERED ROADS THERE...AND
BEING THE FIRST SNOW...THERE WILL BE SOME IMPACTS TO ADVISORY
DRIVERS. WILL RUN IT THROUGH 3 PM AS IT APPEARS THERE WILL BE A
LULL BETWEEN THE END OF THE SYNOPTIC PCPN AND THE BEGINNING OF THE
LAKE EFFECT THAT KICKS IN TONIGHT.
SHALLOW MOISTURE PROFILES ARE INDICATED BEHIND THE FRONT EARLY THIS
EVENING...THEN DEEPER MOISTURE ARRIVES AS A SHORT WAVE SWINGS
THROUGH OVERNIGHT. THE LAKE EFFECT SHOULD BEGIN TO RAMP UP AFTER
ABOUT 03Z AND SHOULD CONTINUE THE REST OF THE NIGHT AND INTO TUESDAY
MORNING. THE MEAN FLOW IS 340-355 THROUGH THIS PERIOD...SO THIS
FAVORS AREAS WEST OF U.S. 131. THERE SHOULD BE A DOMINATE BAND SET
UP AND DEPENDING ON IT/S EXACT ORIENTATION SOME AREAS NEAR THE
POINTS AND WESTERN ALLEGAN AND VAN BUREN COUNTIES COULD GET A DECENT
SNOW. I HAVE ONE TO FOUR INCHES INDICATED FOR NOW. WILL NOT ISSUE
ANY HEADLINES FOR THE LAKE EFFECT PORTION OF THIS EVENT AS IT SHOULD
BE MAINLY TOWARD MIDNIGHT INTO THE OVERNIGHT HOURS AND WE HAVE TIME
TO FINE TUNE THINGS.
THE SNOWS WILL DIMINISH TUESDAY AFTERNOON AS THE SHORT WAVE PASSES
AND THE MOISTURE BECOMES INCREASINGLY SHALLOW. QUIET WEATHER IS
EXPECTED FOR TUESDAY NIGHT AND WEDNESDAY WITH SURFACE AND UPPER
RIDGING BUILDING IN. TEMPS WILL WARM TO THE LOW AND MID 40S FOR WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
THE LONG TERM PERIOD WILL FEATURE TEMPERATURES MODERATING ABOVE
NORMAL AS A SOUTHWEST FLOW ALOFT DEVELOPS AHEAD OF AN EVOLVING
LONGWAVE TROUGH OVER THE WESTERN UNITED STATES.
PREDOMINATELY DRY WEATHER WILL PREVAIL THROUGH SATURDAY AS A LARGE
DRY SURFACE HIGH BECOMES PARKED OVER THE EASTERN HALF OF THE NATION.
THERE IS A LOW CHANCE OF RAIN OR MIXED RAIN AND SNOW SHOWERS WITH
THE PASSAGE OF A WEAK FRONTAL BOUNDARY THURSDAY NIGHT AND FRIDAY BUT
ONLY VERY LIGHT PRECIP AMOUNTS EXPECTED DUE TO THE OVERALL LACK OF
MOISTURE ALONG THE FRONT.
A BIG NORTHWARD SURGE OF MOISTURE FROM THE GULF OF MEXICO GETS
UNDERWAY SATURDAY NIGHT AND SUNDAY... SO INCREASING CHANCES FOR RAIN
EXPECTED ALONG WITH MILD TEMPS IN THE 50S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1246 PM EST MON NOV 11 2013
BIGGEST ITEMS OF INTEREST WITH THE 18Z FCSTS WILL BE CIG/VSBY
TRENDS ALONG WITH PCPN TYPE FOR THE FIRST FEW HOURS...THEN CLOUD
AND LAKE EFFECT TRENDS FOR THE REMAINDER OF THE PERIOD.
RAIN IS ONGOING OVER MOST OF THE TERMINALS AS OF 1730Z WITH KMKG
JUST CHANGING TO SNOW AT 17Z. IFR CONDITIONS ARE BEING FOUND ALONG
THE PCPN CHANGEOVER LINE THAT SHOULD MOVE THROUGH KGRR JUST AFTER
18Z. WE EXPECT CONDITIONS TO LOWER TO IFR ACROSS THE I-94
TERMINALS THROUGH 21Z AND A CHANGE OVER TO SNOW SHORTLY
THEREAFTER. WINDS WILL CHANGE TO COME FROM DUE NORTH ALSO AND
GUST A BIT TO AROUND 20 KNOTS OR SO.
THE BACK EDGE OF THE WIDESPREAD PCPN IS JUST COMING INTO KLDM AS OF
1740Z. WE EXPECT THIS TO ADVANCE SOUTH THROUGH THE AREA AND CLEAR
THE KJXN AREA LAST AROUND 23Z THIS EVENING. CONDITIONS SHOULD
IMPROVE TO MVFR AND EVENTUALLY VFR AS THE PCPN ENDS.
A LAKE EFFECT BAND OF MODERATE TO INTENSE SNOW SHOWERS SHOULD
DEVELOP OVER THE LAKE JUST OFFSHORE THIS EVENING AND TONIGHT AS
THE MEAN FLOW SHOULD BE FROM THE NORTH. INLAND LOCATIONS WILL NOT
BE AFFECTED...AND IT SHOULD REMAIN JUST WEST OF KMKG. THIS COULD
IMPACT ANY FLIGHTS TAKING OFF OR COMING INTO KMKG FROM THE WEST.
OTHERWISE...A BKN STRATOCU DECK BASED AROUND 3500 FT SHOULD RULE
FOR MOST OTHER AREAS TONIGHT AND THROUGH 18Z TUE.
&&
.MARINE...
ISSUED AT 831 AM EST MON NOV 11 2013
I UPDATED THE GRIDS TO SHOW GALES IN THE NEAR SHORE FORECAST THIS
AFTERNOON AND TONIGHT. CURRENTLY (830 AM) ONLY ONE STATION NEAR
GREEN BAY HAS GUSTS TO GALE FORCE BUT GIVEN THE STRENGTH OF THE
COLD ADVECTION OVER A RELATIVELY WARM LAKE MICHIGAN (50 DEGREE) IT
WOULD SEEM WE SHOULD SEE THE GALES THIS AFTERNOON AND THIS
EVENING.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON NOV 11 2013
NO ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ038>040.
LM...GALE WARNING UNTIL 8 AM EST TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...NJJ
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION...CORRECTED
NWS GRAND RAPIDS MI
1217 PM EST MON NOV 11 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 343 AM EST MON NOV 11 2013
MUCH COLDER AIR WILL BE PUSHING INTO THE REGION TODAY AS A COLD
FRONT MOVES THROUGH. RAIN IS EXPECTED THIS MORNING...WHICH WILL
CHANGE OVER TO SNOW FROM NORTH TO SOUTH THIS AFTERNOON. MOST AREAS
WILL SEE LITTLE OR NO SNOW ACCUMULATION...BUT AREAS NEAR HIGHWAY 10
COULD SEE AN INCH OR TWO BY THIS AFTERNOON. TEMPERATURES WILL FALL
THROUGH THE 30S THIS AFTERNOON AND INTO THE 20S TONIGHT.
LAKE EFFECT SNOW WILL INCREASE INTO TONIGHT AND ADDITIONAL SNOW
ACCUMULATIONS ARE LIKELY MAINLY WEST OF U.S. 131. ONE TO LOCALLY
FOUR INCHES WILL BE POSSIBLE TONIGHT THROUGH NOON TUESDAY.
QUIETER WEATHER IS EXPECTED BY MID WEEK AND TOWARD THE WEEKEND.
TEMPERATES WILL WARM TO MAINLY 45 TO 50.
&&
.UPDATE...
ISSUED AT 1115 AM EST MON NOV 11 2013
SO FAR (11 AM) THE FORECAST IS ON TRACK. THE RAIN TO SNOW LINE IS
JUST BEHIND THE COLD FRONT BUT THE BELOW FREEZING TEMPERATURES
REMAIN NORTH OF ROUTE 10 YET. THE RAIN TO SNOW LINE IS NEAR ROUTE
20. I EXPECT THE THE MAIN AREA OF RAIN ASSOCIATED WITH RR QUAD OF
TO CONTINUE PROGRESS SOUTH WITH TIME. THE BACK EDGE OF THE
PRECIPITATION SHOULD BE MOVING SOUTH THROUGH THE CWA AFTER 2 PM
AND REACH THE I-96 AREA BY 4 PM AND I-96 BY 6 PM.
AS FOR THE SNOW...THE RAIN/SNOW LINE SHOULD REACH THE GRR AREA
BETWEEN 2 PM AND 3 PM... SO MAYBE AN HOUR OR TWO OF WET SNOW
BEFORE IT END. I DO NOT SEE MUCH ACCUMULATION OUTSIDE OUR ADVISORY
AREA. UP THERE...SINCE UP TO 3 INCHES HAS ALREADY FALLEN... AND
THERE SEEMS TO BE A LAKE ENHANCED AREA OF SNOW MOVING SOUTH OVER
NORTHERN LOWER MICHIGAN...THEY COULD SEE ANOTHER 1 TO 2 INCHES
BRINGING THE STORM TOTAL TO 5 INCHES.
I MAY NEED SOME SORT OF LAKE EFFECT SNOW ADVISORY FOR VAN BUREN
AND POSSIBLY EXTREME WESTERN ALLEGAN COUNTY AS LATE MODEL RUNS
SUGGEST THE SNOW BAND MAY MOVE ON SHORE OVERNIGHT. ALSO THE SNOW
BAND OFF LAKE SUPERIOR IS SHOWN BY SEVERAL HIGH RES MODELS TO
REACH WELL INTO OUR NORTHERN CWA NEAR US-131 SO I MAY NEED AN
ADVISORY UP THERE TOO FOR THE AFTERNOON FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
A COLD FRONT WAS PUSHING SOUTHEAST ACROSS THE GREEN BAY REGION EARLY
THIS MORNING. IT WILL SLIDE ACROSS THE GRR CWA BETWEEN 12Z AND
18Z. TEMPS WILL BE WARM ENOUGH FOR ALL RAIN AHEAD OF THE
FRONT...THEN AN HOUR OR TWO AFTER IT PASSES WE SHOULD WET BULB DOWN
TO SWITCH OVER THE ALL SNOW.
HAVE DECIDED TO POST A WINTER WEATHER ADVISORY FOR LAKE...OSCEOLA
AND CLARE COUNTIES. SNOWFALL RATES LATER THIS MORNING INTO EARLY
THIS AFTERNOON COULD PRODUCE SLUSHY/SNOW COVERED ROADS THERE...AND
BEING THE FIRST SNOW...THERE WILL BE SOME IMPACTS TO ADVISORY
DRIVERS. WILL RUN IT THROUGH 3 PM AS IT APPEARS THERE WILL BE A
LULL BETWEEN THE END OF THE SYNOPTIC PCPN AND THE BEGINNING OF THE
LAKE EFFECT THAT KICKS IN TONIGHT.
SHALLOW MOISTURE PROFILES ARE INDICATED BEHIND THE FRONT EARLY THIS
EVENING...THEN DEEPER MOISTURE ARRIVES AS A SHORT WAVE SWINGS
THROUGH OVERNIGHT. THE LAKE EFFECT SHOULD BEGIN TO RAMP UP AFTER
ABOUT 03Z AND SHOULD CONTINUE THE REST OF THE NIGHT AND INTO TUESDAY
MORNING. THE MEAN FLOW IS 340-355 THROUGH THIS PERIOD...SO THIS
FAVORS AREAS WEST OF U.S. 131. THERE SHOULD BE A DOMINATE BAND SET
UP AND DEPENDING ON IT/S EXACT ORIENTATION SOME AREAS NEAR THE
POINTS AND WESTERN ALLEGAN AND VAN BUREN COUNTIES COULD GET A DECENT
SNOW. I HAVE ONE TO FOUR INCHES INDICATED FOR NOW. WILL NOT ISSUE
ANY HEADLINES FOR THE LAKE EFFECT PORTION OF THIS EVENT AS IT SHOULD
BE MAINLY TOWARD MIDNIGHT INTO THE OVERNIGHT HOURS AND WE HAVE TIME
TO FINE TUNE THINGS.
THE SNOWS WILL DIMINISH TUESDAY AFTERNOON AS THE SHORT WAVE PASSES
AND THE MOISTURE BECOMES INCREASINGLY SHALLOW. QUIET WEATHER IS
EXPECTED FOR TUESDAY NIGHT AND WEDNESDAY WITH SURFACE AND UPPER
RIDGING BUILDING IN. TEMPS WILL WARM TO THE LOW AND MID 40S FOR WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
THE LONG TERM PERIOD WILL FEATURE TEMPERATURES MODERATING ABOVE
NORMAL AS A SOUTHWEST FLOW ALOFT DEVELOPS AHEAD OF AN EVOLVING
LONGWAVE TROUGH OVER THE WESTERN UNITED STATES.
PREDOMINATELY DRY WEATHER WILL PREVAIL THROUGH SATURDAY AS A LARGE
DRY SURFACE HIGH BECOMES PARKED OVER THE EASTERN HALF OF THE NATION.
THERE IS A LOW CHANCE OF RAIN OR MIXED RAIN AND SNOW SHOWERS WITH
THE PASSAGE OF A WEAK FRONTAL BOUNDARY THURSDAY NIGHT AND FRIDAY BUT
ONLY VERY LIGHT PRECIP AMOUNTS EXPECTED DUE TO THE OVERALL LACK OF
MOISTURE ALONG THE FRONT.
A BIG NORTHWARD SURGE OF MOISTURE FROM THE GULF OF MEXICO GETS
UNDERWAY SATURDAY NIGHT AND SUNDAY... SO INCREASING CHANCES FOR RAIN
EXPECTED ALONG WITH MILD TEMPS IN THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 708 AM EST MON NOV 11 2013
VFR CONDITIONS WILL TREND QUICKLY TOWARD MVFR FROM NORTH TO SOUTH
THIS MORNING AS RAIN DEVELOPS. THE RAIN WILL CHANGE OVER TO A 1-2
HOUR PERIOD OF SNOW WHICH MAY LOWER THE VSBYS INTO IFR CATEGORY
FOR A BRIEF TIME THIS AFTERNOON BEFORE ENDING.
ICING IN THE CLOUDS IS LIKELY TODAY AS THIS BAND OF RAIN AND SNOW
MOVES THROUGH. FREEZING LEVELS DESCENDING FROM 4000-6000 FT AT
12Z... TO AROUND 2500 FT AT 15Z... TO 1000 FT OR LESS AFTER 18Z.
CONDITIONS WILL RETURN TO VFR TONIGHT BEHIND THE COLD FRONT...
ALTHOUGH LAKE EFFECT SNOW SHOWERS MAY RESULT IN PERIODS OF
MVFR/IFR VSBYS ALONG THE LK MI SHORELINE INCLUDING MKG.
SFC WINDS WILL INCREASE TO 12 TO 22 KTS FROM THE WEST THIS MORNING
THEN SHIFT TO THE NORTH AND REMAIN RATHER STRONG/GUSTY THIS
AFTERNOON BEHIND THE COLD FRONT.
&&
.MARINE...
ISSUED AT 831 AM EST MON NOV 11 2013
I UPDATED THE GRIDS TO SHOW GALES IN THE NEAR SHORE FORECAST THIS
AFTERNOON AND TONIGHT. CURRENTLY (830 AM) ONLY ONE STATION NEAR
GREEN BAY HAS GUSTS TO GALE FORCE BUT GIVEN THE STRENGHT OF THE
COLD ADVECTION OVER A RELATIVELY WARM LAKE MICHIGAN (50 DEGREE) IT
WOULD SEEM WE SHOULD SEE THE GALES THIS AFTERNOON AND THIS
EVENING.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON NOV 11 2013
NO ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ038>040.
LM...GALE WARNING UNTIL 8 AM EST TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1115 AM EST MON NOV 11 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 343 AM EST MON NOV 11 2013
MUCH COLDER AIR WILL BE PUSHING INTO THE REGION TODAY AS A COLD
FRONT MOVES THROUGH. RAIN IS EXPECTED THIS MORNING...WHICH WILL
CHANGE OVER TO SNOW FROM NORTH TO SOUTH THIS AFTERNOON. MOST AREAS
WILL SEE LITTLE OR NO SNOW ACCUMULATION...BUT AREAS NEAR HIGHWAY 10
COULD SEE AN INCH OR TWO BY THIS AFTERNOON. TEMPERATURES WILL FALL
THROUGH THE 30S THIS AFTERNOON AND INTO THE 20S TONIGHT.
LAKE EFFECT SNOW WILL INCREASE INTO TONIGHT AND ADDITIONAL SNOW
ACCUMULATIONS ARE LIKELY MAINLY WEST OF U.S. 131. ONE TO LOCALLY
FOUR INCHES WILL BE POSSIBLE TONIGHT THROUGH NOON TUESDAY.
QUIETER WEATHER IS EXPECTED BY MID WEEK AND TOWARD THE WEEKEND.
TEMPERATES WILL WARM TO MAINLY 45 TO 50.
&&
.UPDATE...
ISSUED AT 11115 AM EST MON NOV 11 2013
SO FAR (11 AM) THE FORECAST IS ON TRACK. THE RAIN TO SNOW LINE IS
JUST BEHIND THE COLD FRONT BUT THE BELOW FREEZING TEMPERATURES
REMAIN NORTH OF ROUTE 10 YET. THE RAIN TO SNOW LINE IS NEAR ROUTE
20. I EXPECT THE THE MAIN AREA OF RAIN ASSOCIATED WITH RR QUAD OF
TO CONTINUE PROGRESS SOUTH WITH TIME. THE BACK EDGE OF THE
PRECIPITATION SHOULD BE MOVING SOUTH THROUGH THE CWA AFTER 2 PM
AND REACH THE I-96 AREA BY 4 PM AND I-96 BY 6 PM.
AS FOR THE SNOW...THE RAIN/SNOW LINE SHOULD REACH THE GRR AREA
BETWEEN 2 PM AND 3 PM... SO MAYBE AN HOUR OR TWO OF WET SNOW
BEFORE IT END. I DO NOT SEE MUCH ACCUMULATION OUTSIDE OUR ADVISORY
AREA. UP THERE...SINCE UP TO 3 INCHES HAS ALREADY FALLEN... AND
THERE SEEMS TO BE A LAKE ENHANCED AREA OF SNOW MOVING SOUTH OVER
NORTHERN LOWER MICHIGAN...THEY COULD SEE ANOTHER 1 TO 2 INCHES
BRINGING THE STORM TOTAL TO 5 INCHES.
I MAY NEED SOME SORT OF LAKE EFFECT SNOW ADVISORY FOR VAN BUREN
AND POSSIBLY EXTREME WESTERN ALLEGAN COUNTY AS LATE MODEL RUNS
SUGGEST THE SNOW BAND MAY MOVE ON SHORE OVERNIGHT. ALSO THE SNOW
BAND OFF LAKE SUPERIOR IS SHOWN BY SEVERAL HIGH RES MODELS TO
REACH WELL INTO OUR NORTHERN CWA NEAR US-131 SO I MAY NEED AN
ADVISORY UP THERE TOO FOR THE AFTERNOON FORECAST PACKAGE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
A COLD FRONT WAS PUSHING SOUTHEAST ACROSS THE GREEN BAY REGION EARLY
THIS MORNING. IT WILL SLIDE ACROSS THE GRR CWA BETWEEN 12Z AND
18Z. TEMPS WILL BE WARM ENOUGH FOR ALL RAIN AHEAD OF THE
FRONT...THEN AN HOUR OR TWO AFTER IT PASSES WE SHOULD WET BULB DOWN
TO SWITCH OVER THE ALL SNOW.
HAVE DECIDED TO POST A WINTER WEATHER ADVISORY FOR LAKE...OSCEOLA
AND CLARE COUNTIES. SNOWFALL RATES LATER THIS MORNING INTO EARLY
THIS AFTERNOON COULD PRODUCE SLUSHY/SNOW COVERED ROADS THERE...AND
BEING THE FIRST SNOW...THERE WILL BE SOME IMPACTS TO ADVISORY
DRIVERS. WILL RUN IT THROUGH 3 PM AS IT APPEARS THERE WILL BE A
LULL BETWEEN THE END OF THE SYNOPTIC PCPN AND THE BEGINNING OF THE
LAKE EFFECT THAT KICKS IN TONIGHT.
SHALLOW MOISTURE PROFILES ARE INDICATED BEHIND THE FRONT EARLY THIS
EVENING...THEN DEEPER MOISTURE ARRIVES AS A SHORT WAVE SWINGS
THROUGH OVERNIGHT. THE LAKE EFFECT SHOULD BEGIN TO RAMP UP AFTER
ABOUT 03Z AND SHOULD CONTINUE THE REST OF THE NIGHT AND INTO TUESDAY
MORNING. THE MEAN FLOW IS 340-355 THROUGH THIS PERIOD...SO THIS
FAVORS AREAS WEST OF U.S. 131. THERE SHOULD BE A DOMINATE BAND SET
UP AND DEPENDING ON IT/S EXACT ORIENTATION SOME AREAS NEAR THE
POINTS AND WESTERN ALLEGAN AND VAN BUREN COUNTIES COULD GET A DECENT
SNOW. I HAVE ONE TO FOUR INCHES INDICATED FOR NOW. WILL NOT ISSUE
ANY HEADLINES FOR THE LAKE EFFECT PORTION OF THIS EVENT AS IT SHOULD
BE MAINLY TOWARD MIDNIGHT INTO THE OVERNIGHT HOURS AND WE HAVE TIME
TO FINE TUNE THINGS.
THE SNOWS WILL DIMINISH TUESDAY AFTERNOON AS THE SHORT WAVE PASSES
AND THE MOISTURE BECOMES INCREASINGLY SHALLOW. QUIET WEATHER IS
EXPECTED FOR TUESDAY NIGHT AND WEDNESDAY WITH SURFACE AND UPPER
RIDGING BUILDING IN. TEMPS WILL WARM TO THE LOW AND MID 40S FOR WED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 AM EST MON NOV 11 2013
THE LONG TERM PERIOD WILL FEATURE TEMPERATURES MODERATING ABOVE
NORMAL AS A SOUTHWEST FLOW ALOFT DEVELOPS AHEAD OF AN EVOLVING
LONGWAVE TROUGH OVER THE WESTERN UNITED STATES.
PREDOMINATELY DRY WEATHER WILL PREVAIL THROUGH SATURDAY AS A LARGE
DRY SURFACE HIGH BECOMES PARKED OVER THE EASTERN HALF OF THE NATION.
THERE IS A LOW CHANCE OF RAIN OR MIXED RAIN AND SNOW SHOWERS WITH
THE PASSAGE OF A WEAK FRONTAL BOUNDARY THURSDAY NIGHT AND FRIDAY BUT
ONLY VERY LIGHT PRECIP AMOUNTS EXPECTED DUE TO THE OVERALL LACK OF
MOISTURE ALONG THE FRONT.
A BIG NORTHWARD SURGE OF MOISTURE FROM THE GULF OF MEXICO GETS
UNDERWAY SATURDAY NIGHT AND SUNDAY... SO INCREASING CHANCES FOR RAIN
EXPECTED ALONG WITH MILD TEMPS IN THE 50S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 708 AM EST MON NOV 11 2013
VFR CONDITIONS WILL TREND QUICKLY TOWARD MVFR FROM NORTH TO SOUTH
THIS MORNING AS RAIN DEVELOPS. THE RAIN WILL CHANGE OVER TO A 1-2
HOUR PERIOD OF SNOW WHICH MAY LOWER THE VSBYS INTO IFR CATEGORY
FOR A BRIEF TIME THIS AFTERNOON BEFORE ENDING.
ICING IN THE CLOUDS IS LIKELY TODAY AS THIS BAND OF RAIN AND SNOW
MOVES THROUGH. FREEZING LEVELS DESCENDING FROM 4000-6000 FT AT
12Z... TO AROUND 2500 FT AT 15Z... TO 1000 FT OR LESS AFTER 18Z.
CONDITIONS WILL RETURN TO VFR TONIGHT BEHIND THE COLD FRONT...
ALTHOUGH LAKE EFFECT SNOW SHOWERS MAY RESULT IN PERIODS OF
MVFR/IFR VSBYS ALONG THE LK MI SHORELINE INCLUDING MKG.
SFC WINDS WILL INCREASE TO 12 TO 22 KTS FROM THE WEST THIS MORNING
THEN SHIFT TO THE NORTH AND REMAIN RATHER STRONG/GUSTY THIS
AFTERNOON BEHIND THE COLD FRONT.
&&
.MARINE...
ISSUED AT 831 AM EST MON NOV 11 2013
I UPDATED THE GRIDS TO SHOW GALES IN THE NEAR SHORE FORECAST THIS
AFTERNOON AND TONIGHT. CURRENTLY (830 AM) ONLY ONE STATION NEAR
GREEN BAY HAS GUSTS TO GALE FORCE BUT GIVEN THE STRENGHT OF THE
COLD ADVECTION OVER A RELATIVELY WARM LAKE MICHIGAN (50 DEGREE) IT
WOULD SEEM WE SHOULD SEE THE GALES THIS AFTERNOON AND THIS
EVENING.
&&
.HYDROLOGY...
ISSUED AT 343 AM EST MON NOV 11 2013
NO ISSUES EXPECTED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MIZ038>040.
LM...GALE WARNING UNTIL 8 AM EST TUESDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JK
MARINE...WDM
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1241 PM CST MON NOV 11 2013
.UPDATE...
ISSUED AT 1235 PM CST MON NOV 11 2013
UPDATED THE FORECAST TO INDICATE FALLING TEMPERATURES THROUGHOUT
THE AFTERNOON AND MAINTAIN ISOLATED FLURRIES FOR THE AFTERNOON.
STRATUS SHOULD BREAK UP BY THIS EVENING WITH INCREASING SUBSIDENCE
FROM BUILDING HIGH PRESSURE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST MON NOV 11 2013
MAIN FORECAST CONCERNS WILL BE TEMPERATURES AND FOG EARLY THIS
MORNING.
SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS CENTRAL NEBRASKA AT
THIS TIME THAT HAS BEEN STEADILY MOVING TO THE SOUTH ACROSS
NORTHERN NEBRASKA EARLY THIS MORNING. SATELLITE SHOWS SOME CLOUDS
A WAYS BEHIND THE COLD FRONT. SURFACE OBSERVATIONS HAVE SOME
SPOTTY FOG THAT HAS BEEN REDUCING VISIBILITIES TO LESS THAN A MILE
AT TIMES.
DEW POINTS ACROSS THE AREA ARE FAIRLY HIGH...IN THE UPPER 30S TO
MID 40S. AS TEMPERATURES FALL OFF THE VISIBILITY DROPS IN FOG.
EXPECT THAT WITH THE LIGHT WINDS AHEAD OF THE FRONT AND THE MOIST
AIR THERE WILL BE SOME FOG ACROSS THE AREA EARLY THIS MORNING. AS
THE COLD FRONT MOVES SOUTH THE WINDS WILL TURN TO THE NORTH AND
START TO INCREASE. THIS SHOULD BRING AN END TO THE FOG THIS
MORNING. THE MAIN QUESTION WILL BE HOW WIDESPREAD THE FOG WILL BE
AND HOW LOW THE VISIBILITIES WILL DROP. THE HRRR AND SREF BOTH
REDUCE VISIBILITIES TO LESS THAN A MILE. WILL START WITH THAT AND
WATCH.
THE COLD FRONT IS EXPECTED TO BE MOST...IF NOT ALL...OF THE WAY
THROUGH THE FORECAST AREA BY SUNRISE THIS MORNING. BEHIND THIS COLD
FRONT THERE IS VERY COLD AIR THAT WILL BE PUSHING INTO THE FORECAST
AREA. TEMPERATURES ARE NOT LIKELY TO WARM VERY MUCH AT ALL TODAY AND
WILL PROBABLY FALL THROUGHOUT THE DAY. CLOUDS WILL PUSH INTO THE
FORECAST AREA DURING THE DAY. THERE IS A FAIRLY TIGHT PRESSURE
GRADIENT BEHIND THE COLD FRONT AS WELL. WINDS ALOFT REMAIN MAINLY 10
TO 20 KNOTS SO THE WIND SHOULD BE BREEZY WITH 10 TO 20 MPH AND GUSTS
TO AROUND 25 MPH OR SO.
A COLD HIGH PRESSURE SYSTEM WILL BUILD INTO THE FORECAST AREA
TONIGHT. WITH THIS THE WINDS WILL BE LIGHT...SKIES WILL CLEAR OUT
AND TEMPERATURES WILL CONTINUE TO DROP THROUGH THE NIGHT. LOW
TEMPERATURES IN THE MORNING WILL BE IN THE 5 TO 15 DEGREE RANGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CST MON NOV 11 2013
A STRONG SURFACE HIGH PRESSURE SYSTEM WILL BE NEARLY CENTERED
OVER THE FORECAST AREA TO START THE EXTENDED PERIODS...AND IS
EXPECTED TO DRIFT SLOWLY SOUTHWEST DURING THE DAY TUESDAY.
THEREFORE...WHILE WINDS WILL BE GENERALLY LIGHT AND SHIFTING OUT
OF THE OF THE SOUTH DURING THE AFTERNOON HOURS...TEMPERATURES WILL
BE ON THE COLD SIDE...AS THE HEART OF THE APPROACHING COLD AIRMASS
WILL ENCOMPASS THE ENTIRE FORECAST AREA. AS A RESULT...EXPECTED
HIGH TEMPERATURES TUESDAY TO STRUGGLE TO REACH THE MIDDLE 30S
ACROSS THE ENTIRE AREA...OR ALMOST 20 DEGREES BELOW NORMAL.
TEMPERATURES WILL CONTINUE TO BE THE FOCUS TUESDAY NIGHT...ALBEIT
THE AIRMASS WILL HAVE MODIFIED SOME SINCE MONDAY NIGHT THANKS TO
SOUTHWESTERLY RETURN FLOW...AND EXPECT TEMPERATURES TO BOTTOM OUT IN
THE UPPER TEENS TO LOWER 20S...OR ABOUT 10 DEGREES BELOW NORMAL MID
NOVEMBER LOWS.
THEREAFTER...THE UPPER LEVEL PATTERN WILL BECOME MORE WESTERLY TO
NORTHWESTERLY...WITH MULTIPLE WEAK UPPER LEVEL DISTURBANCES AND
ASSOCIATED FRONTS TRAVERSING THE LOCAL AREA THROUGH NEXT WEEKEND.
WHILE SOME VERY LIGHT PRECIPITATION CANNOT BE RULED OUT FOR TIME TO
TIME...ESPECIALLY THURSDAY AND AGAIN SATURDAY THROUGH SUNDAY...NO
SIGNIFICANT PRECIPITATION ACCUMULATIONS ARE EXPECTED AS THERE WILL
BE LIMITED MOISTURE TO WORK WITH. THE MAIN PIECE OF GOOD NEWS IS
THAT WITH THE MORE WESTERLY FLOW PATTERN...TEMPERATURES SHOULD
MODIFY CLOSER TO...OR EVEN ABOVE...SEASONAL NORMS WEDNESDAY
AFTERNOON ONWARD...AND ANY PRECIPITATION THAT DOES MANAGE TO FORM
WILL BE IN THE FORM OF LIGHT RAIN OR EVEN JUST SPRINKLES.
LATE IN THE UPCOMING WEEKEND AND JUST BEYOND...MODEL DISCREPANCY
GROWS AND THE 00Z EC CONTINUES TO BRING A VERY STRONG ARCTIC FRONT
ACROSS THE LOCAL AREA...WITH 850MB TEMPS DROPPING TO -16C ACROSS THE
LOCAL AREA...WHILE THE GFS MAINTAINS A MUCH MILDER AIRMASS ACROSS
THE LOCAL AREA...KEEPING THE COLDER AIRMASS FURTHER EAST. GIVEN THAT
THE EC APPEARS TO BE AN OUTLIER AT THIS POINT...WITH THE UPPER LEVEL
PATTERNS OF THE GFS ENSEMBLES...UKMET AND GEM LOOKING MORE SIMILAR
TO THE GFS...PLENTY OF UNCERTAINTY REMAINS...SO WILL NEED TO
CONTINUE TO MONITOR THIS TIME PERIOD AS A RETURN TO UNSEASONABLY
COLD TEMPERATURES IS POSSIBLE JUST BEYOND THE CURRENT SCOPE OF THE
EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM CST MON NOV 11 2013
CEILINGS SHOULD GRADUALLY RISE BEFORE SCATTERING OUT TONIGHT WITH
HIGH PRESSURE CREATING QUITE A BIT OF SUBSIDENCE. WIND SPEEDS OUT
OF THE NORTH SHOULD ALSO DIMINISH AS THE SURFACE PRESSURE GRADIENT
RELAXES AND HIGH PRESSURE BUILDS IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...JCB
LONG TERM...SAR
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1200 PM CST MON NOV 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST MON NOV 11 2013
MAIN FORECAST CONCERNS WILL BE TEMPERATURES AND FOG EARLY THIS
MORNING.
SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS CENTRAL NEBRASKA AT
THIS TIME THAT HAS BEEN STEADILY MOVING TO THE SOUTH ACROSS
NORTHERN NEBRASKA EARLY THIS MORNING. SATELLITE SHOWS SOME CLOUDS
A WAYS BEHIND THE COLD FRONT. SURFACE OBSERVATIONS HAVE SOME
SPOTTY FOG THAT HAS BEEN REDUCING VISIBILITIES TO LESS THAN A MILE
AT TIMES.
DEW POINTS ACROSS THE AREA ARE FAIRLY HIGH...IN THE UPPER 30S TO
MID 40S. AS TEMPERATURES FALL OFF THE VISIBILITY DROPS IN FOG.
EXPECT THAT WITH THE LIGHT WINDS AHEAD OF THE FRONT AND THE MOIST
AIR THERE WILL BE SOME FOG ACROSS THE AREA EARLY THIS MORNING. AS
THE COLD FRONT MOVES SOUTH THE WINDS WILL TURN TO THE NORTH AND
START TO INCREASE. THIS SHOULD BRING AN END TO THE FOG THIS
MORNING. THE MAIN QUESTION WILL BE HOW WIDESPREAD THE FOG WILL BE
AND HOW LOW THE VISIBILITIES WILL DROP. THE HRRR AND SREF BOTH
REDUCE VISIBILITIES TO LESS THAN A MILE. WILL START WITH THAT AND
WATCH.
THE COLD FRONT IS EXPECTED TO BE MOST...IF NOT ALL...OF THE WAY
THROUGH THE FORECAST AREA BY SUNRISE THIS MORNING. BEHIND THIS COLD
FRONT THERE IS VERY COLD AIR THAT WILL BE PUSHING INTO THE FORECAST
AREA. TEMPERATURES ARE NOT LIKELY TO WARM VERY MUCH AT ALL TODAY AND
WILL PROBABLY FALL THROUGHOUT THE DAY. CLOUDS WILL PUSH INTO THE
FORECAST AREA DURING THE DAY. THERE IS A FAIRLY TIGHT PRESSURE
GRADIENT BEHIND THE COLD FRONT AS WELL. WINDS ALOFT REMAIN MAINLY 10
TO 20 KNOTS SO THE WIND SHOULD BE BREEZY WITH 10 TO 20 MPH AND GUSTS
TO AROUND 25 MPH OR SO.
A COLD HIGH PRESSURE SYSTEM WILL BUILD INTO THE FORECAST AREA
TONIGHT. WITH THIS THE WINDS WILL BE LIGHT...SKIES WILL CLEAR OUT
AND TEMPERATURES WILL CONTINUE TO DROP THROUGH THE NIGHT. LOW
TEMPERATURES IN THE MORNING WILL BE IN THE 5 TO 15 DEGREE RANGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CST MON NOV 11 2013
A STRONG SURFACE HIGH PRESSURE SYSTEM WILL BE NEARLY CENTERED
OVER THE FORECAST AREA TO START THE EXTENDED PERIODS...AND IS
EXPECTED TO DRIFT SLOWLY SOUTHWEST DURING THE DAY TUESDAY.
THEREFORE...WHILE WINDS WILL BE GENERALLY LIGHT AND SHIFTING OUT
OF THE OF THE SOUTH DURING THE AFTERNOON HOURS...TEMPERATURES WILL
BE ON THE COLD SIDE...AS THE HEART OF THE APPROACHING COLD AIRMASS
WILL ENCOMPASS THE ENTIRE FORECAST AREA. AS A RESULT...EXPECTED
HIGH TEMPERATURES TUESDAY TO STRUGGLE TO REACH THE MIDDLE 30S
ACROSS THE ENTIRE AREA...OR ALMOST 20 DEGREES BELOW NORMAL.
TEMPERATURES WILL CONTINUE TO BE THE FOCUS TUESDAY NIGHT...ALBEIT
THE AIRMASS WILL HAVE MODIFIED SOME SINCE MONDAY NIGHT THANKS TO
SOUTHWESTERLY RETURN FLOW...AND EXPECT TEMPERATURES TO BOTTOM OUT IN
THE UPPER TEENS TO LOWER 20S...OR ABOUT 10 DEGREES BELOW NORMAL MID
NOVEMBER LOWS.
THEREAFTER...THE UPPER LEVEL PATTERN WILL BECOME MORE WESTERLY TO
NORTHWESTERLY...WITH MULTIPLE WEAK UPPER LEVEL DISTURBANCES AND
ASSOCIATED FRONTS TRAVERSING THE LOCAL AREA THROUGH NEXT WEEKEND.
WHILE SOME VERY LIGHT PRECIPITATION CANNOT BE RULED OUT FOR TIME TO
TIME...ESPECIALLY THURSDAY AND AGAIN SATURDAY THROUGH SUNDAY...NO
SIGNIFICANT PRECIPITATION ACCUMULATIONS ARE EXPECTED AS THERE WILL
BE LIMITED MOISTURE TO WORK WITH. THE MAIN PIECE OF GOOD NEWS IS
THAT WITH THE MORE WESTERLY FLOW PATTERN...TEMPERATURES SHOULD
MODIFY CLOSER TO...OR EVEN ABOVE...SEASONAL NORMS WEDNESDAY
AFTERNOON ONWARD...AND ANY PRECIPITATION THAT DOES MANAGE TO FORM
WILL BE IN THE FORM OF LIGHT RAIN OR EVEN JUST SPRINKLES.
LATE IN THE UPCOMING WEEKEND AND JUST BEYOND...MODEL DISCREPANCY
GROWS AND THE 00Z EC CONTINUES TO BRING A VERY STRONG ARCTIC FRONT
ACROSS THE LOCAL AREA...WITH 850MB TEMPS DROPPING TO -16C ACROSS THE
LOCAL AREA...WHILE THE GFS MAINTAINS A MUCH MILDER AIRMASS ACROSS
THE LOCAL AREA...KEEPING THE COLDER AIRMASS FURTHER EAST. GIVEN THAT
THE EC APPEARS TO BE AN OUTLIER AT THIS POINT...WITH THE UPPER LEVEL
PATTERNS OF THE GFS ENSEMBLES...UKMET AND GEM LOOKING MORE SIMILAR
TO THE GFS...PLENTY OF UNCERTAINTY REMAINS...SO WILL NEED TO
CONTINUE TO MONITOR THIS TIME PERIOD AS A RETURN TO UNSEASONABLY
COLD TEMPERATURES IS POSSIBLE JUST BEYOND THE CURRENT SCOPE OF THE
EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM CST MON NOV 11 2013
CEILINGS SHOULD GRADUALLY RISE BEFORE SCATTERING OUT TONIGHT WITH
HIGH PRESSURE CREATING QUITE A BIT OF SUBSIDENCE. WIND SPEEDS OUT
OF THE NORTH SHOULD ALSO DIMINISH AS THE SURFACE PRESSURE GRADIENT
RELAXES AND HIGH PRESSURE BUILDS IN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...SAR
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
523 AM CST MON NOV 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST MON NOV 11 2013
MAIN FORECAST CONCERNS WILL BE TEMPERATURES AND FOG EARLY THIS
MORNING.
SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS CENTRAL NEBRASKA AT
THIS TIME THAT HAS BEEN STEADILY MOVING TO THE SOUTH ACROSS
NORTHERN NEBRASKA EARLY THIS MORNING. SATELLITE SHOWS SOME CLOUDS
A WAYS BEHIND THE COLD FRONT. SURFACE OBSERVATIONS HAVE SOME
SPOTTY FOG THAT HAS BEEN REDUCING VISIBILITIES TO LESS THAN A MILE
AT TIMES.
DEW POINTS ACROSS THE AREA ARE FAIRLY HIGH...IN THE UPPER 30S TO
MID 40S. AS TEMPERATURES FALL OFF THE VISIBILITY DROPS IN FOG.
EXPECT THAT WITH THE LIGHT WINDS AHEAD OF THE FRONT AND THE MOIST
AIR THERE WILL BE SOME FOG ACROSS THE AREA EARLY THIS MORNING. AS
THE COLD FRONT MOVES SOUTH THE WINDS WILL TURN TO THE NORTH AND
START TO INCREASE. THIS SHOULD BRING AN END TO THE FOG THIS
MORNING. THE MAIN QUESTION WILL BE HOW WIDESPREAD THE FOG WILL BE
AND HOW LOW THE VISIBILITIES WILL DROP. THE HRRR AND SREF BOTH
REDUCE VISIBILITIES TO LESS THAN A MILE. WILL START WITH THAT AND
WATCH.
THE COLD FRONT IS EXPECTED TO BE MOST...IF NOT ALL...OF THE WAY
THROUGH THE FORECAST AREA BY SUNRISE THIS MORNING. BEHIND THIS COLD
FRONT THERE IS VERY COLD AIR THAT WILL BE PUSHING INTO THE FORECAST
AREA. TEMPERATURES ARE NOT LIKELY TO WARM VERY MUCH AT ALL TODAY AND
WILL PROBABLY FALL THROUGHOUT THE DAY. CLOUDS WILL PUSH INTO THE
FORECAST AREA DURING THE DAY. THERE IS A FAIRLY TIGHT PRESSURE
GRADIENT BEHIND THE COLD FRONT AS WELL. WINDS ALOFT REMAIN MAINLY 10
TO 20 KNOTS SO THE WIND SHOULD BE BREEZY WITH 10 TO 20 MPH AND GUSTS
TO AROUND 25 MPH OR SO.
A COLD HIGH PRESSURE SYSTEM WILL BUILD INTO THE FORECAST AREA
TONIGHT. WITH THIS THE WINDS WILL BE LIGHT...SKIES WILL CLEAR OUT
AND TEMPERATURES WILL CONTINUE TO DROP THROUGH THE NIGHT. LOW
TEMPERATURES IN THE MORNING WILL BE IN THE 5 TO 15 DEGREE RANGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CST MON NOV 11 2013
A STRONG SURFACE HIGH PRESSURE SYSTEM WILL BE NEARLY CENTERED
OVER THE FORECAST AREA TO START THE EXTENDED PERIODS...AND IS
EXPECTED TO DRIFT SLOWLY SOUTHWEST DURING THE DAY TUESDAY.
THEREFORE...WHILE WINDS WILL BE GENERALLY LIGHT AND SHIFTING OUT
OF THE OF THE SOUTH DURING THE AFTERNOON HOURS...TEMPERATURES WILL
BE ON THE COLD SIDE...AS THE HEART OF THE APPROACHING COLD AIRMASS
WILL ENCOMPASS THE ENTIRE FORECAST AREA. AS A RESULT...EXPECTED
HIGH TEMPERATURES TUESDAY TO STRUGGLE TO REACH THE MIDDLE 30S
ACROSS THE ENTIRE AREA...OR ALMOST 20 DEGREES BELOW NORMAL.
TEMPERATURES WILL CONTINUE TO BE THE FOCUS TUESDAY NIGHT...ALBEIT
THE AIRMASS WILL HAVE MODIFIED SOME SINCE MONDAY NIGHT THANKS TO
SOUTHWESTERLY RETURN FLOW...AND EXPECT TEMPERATURES TO BOTTOM OUT IN
THE UPPER TEENS TO LOWER 20S...OR ABOUT 10 DEGREES BELOW NORMAL MID
NOVEMBER LOWS.
THEREAFTER...THE UPPER LEVEL PATTERN WILL BECOME MORE WESTERLY TO
NORTHWESTERLY...WITH MULTIPLE WEAK UPPER LEVEL DISTURBANCES AND
ASSOCIATED FRONTS TRAVERSING THE LOCAL AREA THROUGH NEXT WEEKEND.
WHILE SOME VERY LIGHT PRECIPITATION CANNOT BE RULED OUT FOR TIME TO
TIME...ESPECIALLY THURSDAY AND AGAIN SATURDAY THROUGH SUNDAY...NO
SIGNIFICANT PRECIPITATION ACCUMULATIONS ARE EXPECTED AS THERE WILL
BE LIMITED MOISTURE TO WORK WITH. THE MAIN PIECE OF GOOD NEWS IS
THAT WITH THE MORE WESTERLY FLOW PATTERN...TEMPERATURES SHOULD
MODIFY CLOSER TO...OR EVEN ABOVE...SEASONAL NORMS WEDNESDAY
AFTERNOON ONWARD...AND ANY PRECIPITATION THAT DOES MANAGE TO FORM
WILL BE IN THE FORM OF LIGHT RAIN OR EVEN JUST SPRINKLES.
LATE IN THE UPCOMING WEEKEND AND JUST BEYOND...MODEL DISCREPANCY
GROWS AND THE 00Z EC CONTINUES TO BRING A VERY STRONG ARCTIC FRONT
ACROSS THE LOCAL AREA...WITH 850MB TEMPS DROPPING TO -16C ACROSS THE
LOCAL AREA...WHILE THE GFS MAINTAINS A MUCH MILDER AIRMASS ACROSS
THE LOCAL AREA...KEEPING THE COLDER AIRMASS FURTHER EAST. GIVEN THAT
THE EC APPEARS TO BE AN OUTLIER AT THIS POINT...WITH THE UPPER LEVEL
PATTERNS OF THE GFS ENSEMBLES...UKMET AND GEM LOOKING MORE SIMILAR
TO THE GFS...PLENTY OF UNCERTAINTY REMAINS...SO WILL NEED TO
CONTINUE TO MONITOR THIS TIME PERIOD AS A RETURN TO UNSEASONABLY
COLD TEMPERATURES IS POSSIBLE JUST BEYOND THE CURRENT SCOPE OF THE
EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 524 AM CST MON NOV 11 2013
THE COLD FRONT HAS MOVED THROUGH THE KGRI TERMINAL AREA ALREADY THIS
MORNING. WINDS WILL START TO INCREASE AND BECOME GUSTY LATER THIS
MORNING BEFORE DIMINISHING THIS EVENING. THERE WILL ALSO BE SOME
CLOUDS THAT WILL MOVE INTO THE AREA THIS MORNING. THERE COULD BE
SOME MVFR CEILINGS FOR A WHILE THIS AFTERNOON. THE CLOUDS WILL
DIMINISH AFTER DARK TONIGHT AS A SURFACE HIGH MOVES INTO THE AREA.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...SAR
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
352 AM CST MON NOV 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 353 AM CST MON NOV 11 2013
MAIN FORECAST CONCERNS WILL BE TEMPERATURES AND FOG EARLY THIS
MORNING.
SURFACE ANALYSIS SHOWS A COLD FRONT ACROSS CENTRAL NEBRASKA AT
THIS TIME THAT HAS BEEN STEADILY MOVING TO THE SOUTH ACROSS
NORTHERN NEBRASKA EARLY THIS MORNING. SATELLITE SHOWS SOME CLOUDS
A WAYS BEHIND THE COLD FRONT. SURFACE OBSERVATIONS HAVE SOME
SPOTTY FOG THAT HAS BEEN REDUCING VISIBILITIES TO LESS THAN A MILE
AT TIMES.
DEW POINTS ACROSS THE AREA ARE FAIRLY HIGH...IN THE UPPER 30S TO
MID 40S. AS TEMPERATURES FALL OFF THE VISIBILITY DROPS IN FOG.
EXPECT THAT WITH THE LIGHT WINDS AHEAD OF THE FRONT AND THE MOIST
AIR THERE WILL BE SOME FOG ACROSS THE AREA EARLY THIS MORNING. AS
THE COLD FRONT MOVES SOUTH THE WINDS WILL TURN TO THE NORTH AND
START TO INCREASE. THIS SHOULD BRING AN END TO THE FOG THIS
MORNING. THE MAIN QUESTION WILL BE HOW WIDESPREAD THE FOG WILL BE
AND HOW LOW THE VISIBILITIES WILL DROP. THE HRRR AND SREF BOTH
REDUCE VISIBILITIES TO LESS THAN A MILE. WILL START WITH THAT AND
WATCH.
THE COLD FRONT IS EXPECTED TO BE MOST...IF NOT ALL...OF THE WAY
THROUGH THE FORECAST AREA BY SUNRISE THIS MORNING. BEHIND THIS COLD
FRONT THERE IS VERY COLD AIR THAT WILL BE PUSHING INTO THE FORECAST
AREA. TEMPERATURES ARE NOT LIKELY TO WARM VERY MUCH AT ALL TODAY AND
WILL PROBABLY FALL THROUGHOUT THE DAY. CLOUDS WILL PUSH INTO THE
FORECAST AREA DURING THE DAY. THERE IS A FAIRLY TIGHT PRESSURE
GRADIENT BEHIND THE COLD FRONT AS WELL. WINDS ALOFT REMAIN MAINLY 10
TO 20 KNOTS SO THE WIND SHOULD BE BREEZY WITH 10 TO 20 MPH AND GUSTS
TO AROUND 25 MPH OR SO.
A COLD HIGH PRESSURE SYSTEM WILL BUILD INTO THE FORECAST AREA
TONIGHT. WITH THIS THE WINDS WILL BE LIGHT...SKIES WILL CLEAR OUT
AND TEMPERATURES WILL CONTINUE TO DROP THROUGH THE NIGHT. LOW
TEMPERATURES IN THE MORNING WILL BE IN THE 5 TO 15 DEGREE RANGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 353 AM CST MON NOV 11 2013
A STRONG SURFACE HIGH PRESSURE SYSTEM WILL BE NEARLY CENTERED
OVER THE FORECAST AREA TO START THE EXTENDED PERIODS...AND IS
EXPECTED TO DRIFT SLOWLY SOUTHWEST DURING THE DAY TUESDAY.
THEREFORE...WHILE WINDS WILL BE GENERALLY LIGHT AND SHIFTING OUT
OF THE OF THE SOUTH DURING THE AFTERNOON HOURS...TEMPERATURES WILL
BE ON THE COLD SIDE...AS THE HEART OF THE APPROACHING COLD AIRMASS
WILL ENCOMPASS THE ENTIRE FORECAST AREA. AS A RESULT...EXPECTED
HIGH TEMPERATURES TUESDAY TO STRUGGLE TO REACH THE MIDDLE 30S
ACROSS THE ENTIRE AREA...OR ALMOST 20 DEGREES BELOW NORMAL.
TEMPERATURES WILL CONTINUE TO BE THE FOCUS TUESDAY NIGHT...ALBEIT
THE AIRMASS WILL HAVE MODIFIED SOME SINCE MONDAY NIGHT THANKS TO
SOUTHWESTERLY RETURN FLOW...AND EXPECT TEMPERATURES TO BOTTOM OUT IN
THE UPPER TEENS TO LOWER 20S...OR ABOUT 10 DEGREES BELOW NORMAL MID
NOVEMBER LOWS.
THEREAFTER...THE UPPER LEVEL PATTERN WILL BECOME MORE WESTERLY TO
NORTHWESTERLY...WITH MULTIPLE WEAK UPPER LEVEL DISTURBANCES AND
ASSOCIATED FRONTS TRAVERSING THE LOCAL AREA THROUGH NEXT WEEKEND.
WHILE SOME VERY LIGHT PRECIPITATION CANNOT BE RULED OUT FOR TIME TO
TIME...ESPECIALLY THURSDAY AND AGAIN SATURDAY THROUGH SUNDAY...NO
SIGNIFICANT PRECIPITATION ACCUMULATIONS ARE EXPECTED AS THERE WILL
BE LIMITED MOISTURE TO WORK WITH. THE MAIN PIECE OF GOOD NEWS IS
THAT WITH THE MORE WESTERLY FLOW PATTERN...TEMPERATURES SHOULD
MODIFY CLOSER TO...OR EVEN ABOVE...SEASONAL NORMS WEDNESDAY
AFTERNOON ONWARD...AND ANY PRECIPITATION THAT DOES MANAGE TO FORM
WILL BE IN THE FORM OF LIGHT RAIN OR EVEN JUST SPRINKLES.
LATE IN THE UPCOMING WEEKEND AND JUST BEYOND...MODEL DISCREPANCY
GROWS AND THE 00Z EC CONTINUES TO BRING A VERY STRONG ARCTIC FRONT
ACROSS THE LOCAL AREA...WITH 850MB TEMPS DROPPING TO -16C ACROSS THE
LOCAL AREA...WHILE THE GFS MAINTAINS A MUCH MILDER AIRMASS ACROSS
THE LOCAL AREA...KEEPING THE COLDER AIRMASS FURTHER EAST. GIVEN THAT
THE EC APPEARS TO BE AN OUTLIER AT THIS POINT...WITH THE UPPER LEVEL
PATTERNS OF THE GFS ENSEMBLES...UKMET AND GEM LOOKING MORE SIMILAR
TO THE GFS...PLENTY OF UNCERTAINTY REMAINS...SO WILL NEED TO
CONTINUE TO MONITOR THIS TIME PERIOD AS A RETURN TO UNSEASONABLY
COLD TEMPERATURES IS POSSIBLE JUST BEYOND THE CURRENT SCOPE OF THE
EXTENDED FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1120 PM CST SUN NOV 10 2013
A COLD FRONT WILL MOVE THROUGH THE KGRI TERMINAL AREA JUST BEFORE
SUNRISE ON MONDAY MORNING. ALONG WITH THE COLD FRONT THERE WILL BE
SOME MVFR CEILINGS THAT WILL MOVE INTO THE AREA. GUSTY NORTH WINDS
ARE EXPECTED. BY EVENING THE WINDS WILL DIMINISH AND CEILINGS WILL
LIFT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...SAR
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
744 PM EST TUE NOV 12 2013
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL PUSH SOUTH ACROSS THE CAROLINAS THIS
AFTERNOON AND EVENING. STRONG HIGH PRESSURE WILL BUILD INTO THE
REGION LATE TONIGHT AND WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM TUESDAY...
LATEST ANALYSIS SHOWS THE ARCTIC FRONT MOVING INTO THE SOUTHERN
PIEDMONT AND SANDHILLS REGION AT 19Z. SURFACE COLD ADVECTION FINALLY
BEGINNING TO KICK IN WITH TEMPERATURES FALLING INTO THE UPPER 40S
NEAR THE VIRGINIA BORDER OUTSIDE OF ANY COOLING CONTRIBUTIONS FROM
PRECIPITATION. TEMPERATURES EARLIER TODAY CLIMBED INTO THE UPPER 50S
TO MID 60S IN MOST LOCATIONS...IT MADE IT TO 61 IN WINSTON-SALEM...
WHICH IS NOT A TYPICAL OR FAVORABLE SCENARIO FOR AN IMPENDING WINTER
EVENT. HOWEVER...LATEST REGIONAL RADAR IMAGERY SHOWS PRECIPITATION
MOSTLY ALOFT BREAKING OUT ACROSS SOUTHWESTERN VIRGINIA AND EXPANDING
INTO THE NORTHWEST PIEDMONT AND TRIAD AREA. DUAL POL RADAR ANALYSIS
FROM KRAX SHOWS THE PRECIPITATION AT 4-8KFT APPEARS TO BE ALL SNOW.
JUST NOW GETTING SOME REPORTS OF PRECIPITATION AT THE SURFACE WITH
LIGHT RAIN IN ROXBORO AND REIDSVILLE WHICH IS NOT SURPRISING GIVEN
THE GENERAL UPWARD TREND IN REFLECTIVITY VALUES NOW PEAKING AT
AROUND 25DBZ.
RECENT RAP AND HRRR RUNS...AS WELL AS MANY OF THE HIGHER RESOLUTION
CAM MODELS HAVE BEEN HIGHLIGHT RECENT RADAR TRENDS AND SUGGESTING
THAT A BAND OR AREA OF LIGHT PRECIPITATION SHOULD CONTINUE TO
DEVELOP ACROSS THE NORTHERN AND NORTHWESTERN PIEDMONT AND SHIFT
SOUTHEAST DURING THE EVENING. GUIDANCE INCLUDING THE RAP/NAM/GFS ARE
VERY CONSISTENT IN SHOWING THAT THE GREATEST PRECIPITATION AMOUNTS
ARE LIKELY TO FALL IN A CORRIDOR BETWEEN RALEIGH/FAYETTEVILLE WEST
TO GREENSBORO/ALBEMARLE WHERE AMOUNTS WILL GENERALLY RANGE BETWEEN
0.05 AND 0.10 INCHES WITH A SWEET SPOT AND LOCALLY HIGHER AMOUNTS
POTENTIALLY NEAR BURLINGTON AND ASHEBORO. WITH COOLING ALOFT AND
SATURATION EXTENDING INTO THE ICE NUCLEATION REGION...PRECIPITATION
SHOULD DEVELOP AS SNOW ALOFT WITH BOUNDARY LAYER CONDITIONS
DETERMINING WHETHER THE PRECIPITATION FALLS AS RAIN OR SNOW. WET
BULB TEMPERATURES AT 19Z WERE IN THE UPPER 30S IN THE VA BORDER
COUNTIES WITH COLD/DRY ADVECTION PUSHING SOUTH INTO CENTRAL NC. AS
COLDER AND DRIER AIR FILTERS INTO THE AREA FROM THE NORTH...EXPECT
THE RAIN TO MIX WITH SNOW AND GRADUALLY CHANGE TO A MOSTLY WET SNOW
FROM NORTH TO SOUTH BEFORE ENDING. LOCATIONS MOST LIKELY TO SEE MORE
SNOW THAN RAIN WILL BE CLOSER TO THE VA BORDER AND IN THE TRIAD
REGION WHERE COLDER AND DRIER SURFACE CONDITIONS ARE PRESENT. THE
PRECIPITATION DURATION WILL TYPICALLY LAST 2-4 HOURS LONG WITH MUCH
OF IT FALLING AS JUST RAIN. THIS SHOULD CONFINE TO ACTUAL SNOW
LIQUID QPF ON THE ORDER OF 0.05 OR LESS. THESE AMOUNTS WITH SURFACE
TEMPERATURES REMAINING AT LEAST SEVERAL DEGREES ABOVE FREEZING AND A
WARM GROUND THROUGH THE EARLY EVENING HOURS SHOULD RESULT LITTLE TO
NO ACCUMULATION WITH NO IMPACTS EXPECTED. NOTE THOUGH THAT A HEAVIER
AND MORE PERSISTENT BURST OF SNOW WHICH IS POSSIBLE IN A PATTERN
SUCH AS THIS WITH STRONG FRONTOGENESIS AND FORCING ALOFT COULD BE
SUFFICIENT TO PROVIDE A QUICK COATING OF WET SNOW BEFORE THE
ACCUMULATED SNOW MELTS ONCE THE PRECIPITATION ENDS.
ALL OF THE PRECIPITATION WILL END FROM NORTHWEST TO SOUTHEAST
BETWEEN 02-05Z WITH CLEARING SKIES QUICKLY ARRIVING AFTER THE
PRECIPITATION ENDS. SURFACE TEMPERATURES...THE AMOUNT OF
PRECIPITATION AND WETNESS ALONG WITH DRYING FROM THE NORTHERLY WINDS
WILL NEED TO BE MONITORED FOR SOME POSSIBLY ICY SPOTS BUT A WARM
GROUND SHOULD LIMIT THIS POTENTIAL. STRONG CAA SHOULD SUPPORT LOWS
IN THE 24-29 DEGREE RANGE OVERNIGHT. -BLAES
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 320 PM TUESDAY...
PROGRESSIVE TROUGH MOVES ACROSS THE MID ATLANTIC EARLY ON WEDNESDAY
AND THEN MOVES OFF THE COAST AS A STRONG 1040MB SURFACE HIGH BUILDS
INTO THE LOWER MISSISSIPPI VALLEY ON WEDNESDAY AND THEN SETTLES OVER
GA/SC ON WEDNESDAY NIGHT. MAINLY CLEAR SKIES ARE EXPECTED THROUGH
THE PERIOD WITH A DRY ATMOSPHERE AND LOTS OF SUBSIDENCE. COLD
TEMPERATURES WITH HIGHS ONLY REACHING THE MID 40S ON WEDNESDAY. LOWS
WEDNESDAY NIGHT WILL FALL INTO THE LOWER TO MID 20S... WITH
TYPICALLY COLDER SPOTS FALLING TO AROUND 20. -BLAES
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 PM TUESDAY...
THU AND THU NIGHT: THE CENTER OF THE MODIFIED ARCTIC SURFACE
RIDGE...ONE THAT PEAKED AT 1048 MB OVER KS AND NE EARLIER TODAY...
WILL DRIFT ACROSS THE CAROLINAS THU AND THU NIGHT. DEEP LAYER
DRYNESS...INCLUDING AT THE SURFACE WITH DEWPOINTS IN THE
TEENS...WILL FAVOR CONTINUED CLEAR SKIES. DRY ADIABATIC...BUT
SHALLOW MIXING TO ABOUT 2000 FEET AMIDST THE ARCTIC RIDGING...
SUPPORTS HIGHS GENERALLY IN THE MIDDLE 50S. CIRRUS ASSOCIATED WITH A
DEAMPLIFYING SHORTWAVE TROUGH IN SW FLOW ALOFT WILL INCREASE
OVERNIGHT...BUT MODEL GUIDANCE INDICATES AT THIS TIME THAT IT WILL
BE THIN ENOUGH TO NOT SIGNIFICANTLY HINDER GOOD RADIATIONAL COOLING
ONCE AGAIN...INTO THE UPPER 20S TO LOWER 30S GIVEN PROJECTED LOW
LEVEL THICKNESS VALUES AROUND 1335 METERS.
FRI THROUGH TUE: MEDIUM RANGE GUIDANCE REMAINS IN GENERAL
AGREEMENT WITH THE DEVELOPMENT OF A L/W TROUGH OVER THE ROCKIES AND
DOWNSTREAM RIDGING OVER THE CARIBBEAN THROUGH EARLY NEXT WEEK...BUT
SHORTWAVE/SYNOPTIC DIFFERENCES AND DETAILS REMAIN...AND AS SUCH...
FORECAST CONFIDENCE REMAINS ONLY AVERAGE.
THE MOST LIKELY SOLUTION IS STILL FOR A LEAD SHORTWAVE TROUGH TO
DEAMPLIFY THROUGH THE TN AND OH VALLEYS FRI AND FRI NIGHT. THE
ASSOCIATED SYNOPTIC SCALE...ALBEIT WEAK FORCING FOR ASCENT WITH THIS
FEATURE...IN CONJUNCTION WITH MOIST LOW LEVEL RETURN FLOW AROUND THE
MODIFIED SURFACE RIDGE...AND THE DEVELOPMENT OF AN INVERTED SURFACE
TROUGH INTO THE EASTERN CAROLINAS...WILL SUPPORT A 20-30 PERCENT
CHANCE OF SHOWERS LATE FRI AND ESPECIALLY FRI NIGHT. CARIBBEAN
RIDGING WILL THEN STRENGTHEN ACROSS THE SOUTHEAST US IN RESPONSE TO
UPSTREAM TROUGH AMPLIFICATION OVER THE ROCKIES...AND THIS PROCESS
MAY THEN PROMOTE GENERALLY DRY...BUT MOSTLY CLOUDY CONDITIONS
THROUGH MOST OF THE WEEKEND. WILL RETAIN A SMALL CHANCE OF SHOWERS
TO MAINTAIN FORECAST CONTINUITY SAT-SUN...HOWEVER.
THE BETTER CHANCE OF SHOWERS IN INCREASINGLY STRONG AND MOIST
SOUTHERLY FLOW FROM THE GULF OF MEXICO WILL OCCUR AHEAD OF AND ALONG
A SLOW-MOVING COLD FRONT MON-TUE. MILDER WITH HIGHS IN THE 60S...TO
LOWER 70S IN THE COASTAL PLAIN...WITH LOWS IN THE 50S.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 730 PM TUESDAY...
24-HR TAF PERIOD:
AN UPPER LEVEL DISTURBANCE IS CURRENTLY MOVING ACROSS THE REGION...
SUPPORTING AREAS OF LIGHT PRECIP (GENERALLY A MIX OF RAIN AND SNOW)
THIS EVENING ACROSS CENTRAL NC. THE LIGHT PRECIP HAS MOVED JUST TO
THE SOUTH AND EAST OF THE TRIAD TERMINALS (KINT/KGSO). EXPECT ONLY A
COUPLE MORE HOURS OR SO OF LIGHT SNOW/RAIN AT KRDU/KRWI AS THE
PRECIP SHIFTS SOUTH AND EASTWARD... GENERALLY OVER BY 03Z OR SO.
FURTHER SOUTH AT KFAY THE PRECIP MAY LINGER LONGER... GENERALLY DONE
BY 04/05Z OR SO. MVFR/IFR CIGS WILL ACCOMPANY THE THE PRECIP (ALONG
WITH MVFR/MAYBE IFR VISBYS IN THE HEAVIEST PRECIP) AS IT MOVES INTO
A GIVEN AREA... POSSIBLY LINGERING AN HOUR OR TWO AFTER THE PRECIP
ENDS. STILL THINK WE SHOULD SEE VFR CONDITIONS WITH CLEARING SKIES
AFTER 06/07Z OR SO FOR THE ENTIRE AREA. HIGH PRESSURE WILL BUILD
INTO THE AREA BEHIND THE DEPARTING SYSTEM... WITH A RETURN TO
CLEAR/SUNNY SKIES AND VFR CONDITIONS. HOWEVER... WE WILL CONTINUE TO
HAVE BREEZY NORTHWEST TO NORTHERLY WINDS ACROSS THE AREA OVERNIGHT
INTO WEDNESDAY... WITH SUSTAINED WINDS IN THE 07 TO 13 KT RANGE...
WITH GUSTS OF UP TO 15 TO 20 KTS (MAYBE A BIT WEAKER LATE
WEDNESDAY). WE SHOULDN`T SEE THE 30 TO 35 KT GUSTS AT KFAY PERSIST
MUCH LONGER WITH THE PRECIP MOVING INTO THE SOUTHERN SANDHILLS
(INVOF KFAY) ANYTIME. -BSD
LOOKING AHEAD:
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST FRIDAY NIGHT
AS SURFACE HIGH PRESSURE REMAINS IN CONTROL OVER THE AREA. THE
POTENTIAL FOR UNSETTLED WEATHER ARRIVES FOR THE WEEKEND AS THE
SURFACE HIGH RETREATS OFFSHORE AND A SOUTHWESTERLY FLOW ALOFT
TRANSPORTS MOISTURE INTO THE AREA. AREAS OR PERIODS OF SUB-VFR
CONDITIONS ARE POSSIBLE IN RAIN SHOWERS ON SATURDAY INTO SUNDAY.
-BLAES
&&
.CLIMATE...
HERE ARE THE RECORD LOW MAXIMUM TEMPERATURES FOR NOVEMBER 13TH AND
RECORD LOWS FOR NOVEMBER 14TH.
RECORD LOW MAXIMUM TEMP 11/13:
RDU: 39 (1911)
GSO: 35 (1907)
FAY: 43 (1976)
RECORD LOW 11/14:
RDU: 20 (1977)
GSO: 19 (1986)
FAY: 24 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...MWS
AVIATION...BSD/BLAES
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
940 PM CST TUE NOV 12 2013
.UPDATE...
ISSUED AT 940 PM CST TUE NOV 12 2013
NO SIGNIFICANT UPDATES TO THE LATE EVENING FORECAST. LATEST
OBSERVATIONS SHOW TEMPERATURES DROPPING CLOSE TO OVERNIGHT LOWS IN
SOME AREAS. BUT WITH A MODERATE SOUTHERLY FLOW...DO NOT THINK
TEMPERATURES WILL FALL OFF MUCH TONIGHT. DID LOWER TEMPERATURES IN
SOME AREAS WHERE TEMPERATURES WERE WITHIN A DEGREE OR SO OF
MINIMUM TEMPERATURES AS SKY COVER REMAINS MINIMAL AND WINDS COULD
DIMINISH A BIT LATER TONIGHT BEFORE SHIFTING WEST. OVERALL VERY
FEW CHANGES TO THE GOING FORECAST.
UPDATE ISSUED AT 638 PM CST TUE NOV 12 2013
MAINLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS EVENING. LATEST SATELLITE IMAGERY SHOWS A SHORTWAVE OVER
ALBERTA WHICH WILL TRACK ACROSS SASKATCHEWAN AND INTO MANITOBA BY
EARLY WEDNESDAY MORNING. THE SURFACE LOW ASSOCIATED WITH THIS
WAVE WILL BRING A WARM FRONT ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT...FOLLOWED BY A WEAK DRY COLD FRONT LATE TONIGHT
AND WEDNESDAY. MAIN FORECAST ISSUE TONIGHT WILL BE TEMPERATURES.
THE TEMPERATURE AT WILLISTON DROPPED 10 DEGREES BETWEEN 5 AND 6 PM
CST. COULD SEE A FEW OTHER LOCALES DROP QUICKLY THIS EVENING...BUT
IN GENERAL...MILD SOUTHWEST FLOW WILL KEEP TEMPERATURES MUCH
WARMER TONIGHT WITH MID 20S TO MID 30S READINGS INSTEAD OF SINGLE
DIGITS AND LOW TEENS. MID AND HIGH LEVEL CLOUDINESS WILL ALSO
INCREASE FROM WEST TO EAST LATER THIS EVENING AND OVERNIGHT. NO
SIGNIFICANT CHANGES TO THE GOING FORECAST WERE WARRANTED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
THE MAIN HIGHLIGHTS IN THE SHORT TERM WILL BE A WARM FRONTAL PASSAGE
TONIGHT...MOVING FROM EASTERN MONTANA INTO CENTRAL NORTH DAKOTA.
THIS WILL THEN BE FOLLOWED BY A COLD FRONTAL PASSAGE WEDNESDAY
MORNING. DRY WEATHER WILL ACCOMPANY BOTH FRONTS. LOW LEVEL WARM AIR
ADVECTION CONTINUES OVERNIGHT INTO WEDNESDAY MORNING. WESTERLY WINDS
DEVELOPING IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY WILL
HELP MIX DOWN WARMER TEMPS ALOFT BEFORE THE COLD AIR ADVECTION
COMPLETELY ERODES THE WARM LAYER BY 00Z THURSDAY. HIGH TEMPERATURES
WEDNESDAY WILL REACH INTO THE MID AND UPPER 40S NORTH CENTRAL INTO
EAST CENTRAL...TO AROUND 50 DEGREES SOUTH CENTRAL...AND LOWER 50S
SOUTHWEST AND FAR SOUTH.
ANOTHER CONCERN IS THE POTENTIAL FOR STRATUS ASSOCIATED WITH THE
WARM AIR ADVECTION...ALONG AND AHEAD OF THE WARM FRONT THIS
EVENING AND INTO TONIGHT. THE NAM/RAP13 925MB RH FIELDS HAVE NOT
BEEN INITIALIZING WELL AT ALL TODAY...AS THEY HAVE BEEN INDICATING
A HIGH AMOUNT OF LOW LEVEL RH THIS AFTERNOON WHERE WE HAVE A CLEAR
SKY...THUS CANNOT USE THIS DATA FOR TONIGHT. THE HRRR REMAINS
CONSISTENT IN DEVELOPING A SWATH OF LESS THAN 500FT CEILINGS
NEAR/OVER THE SNOWCOVER IN SOUTH DAKOTA PER VISIBLE SATELLITE
IMAGERY BY AROUND 00Z WEDNESDAY. THIS SEEMS REASONABLE...BUT THE
RAPID DEVELOPMENT AND EXTENSIVE AREAL EXTENT SEEMS SUSPECT AT THIS
TIME. WILL BRIEF THE INCOMING EVENING SHIFT TO MONITOR THIS. IF
IT DOES MATERIALIZE...THEN BISMARCK TO JAMESTOWN AND ALL AREAS
SOUTH WOULD BE AFFECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
MAIN FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BE THE
PASSAGE OF TWO FRONTAL SYSTEMS.
THE EXTENDED PERIOD BEGINS WEDNESDAY NIGHT WITH AN EMBEDDED MID
LEVEL WAVE PUSHING EAST-SOUTHEAST ACROSS THE NORTHERN PLAINS
WITHIN A LONG WAVE TROUGH DEVELOPING FROM THE HUDSON BAY THROUGH
OUR LOCAL AREA SOUTHWEST INTO THE CENTRAL ROCKIES. WILL MAINTAIN
THE PERCENT AND COVERAGE OF CHANCES FOR PRECIPITATION WEDNESDAY
NIGHT...AND INTO THE DAYTIME HOURS THURSDAY. BUFFER SOUNDINGS
INDICATE WE WILL EITHER SEE RAIN OR SNOW DEPENDING ON SURFACE
TEMPERATURES...WITH THE CAA ADVERTISED IN THE MID TO UPPER LEVELS
OF THE ATMOSPHERE.
WE DRY OUT THURSDAY NIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE
DAKOTAS. FLOW ALOFT TRANSITIONS TO MORE ZONAL AS A VERY BROAD
TROUGH DEVELOPS ACROSS ALL OF NORTH AMERICA. STRONG EMBEDDED
ENERGY PUSHING SOUTHEAST ALONG THE CANADIAN PACIFIC COAST WILL
AMPLIFY THE TROUGH OVER THE WESTERN ROCKIES SATURDAY INTO SATURDAY
NIGHT...WITH THE TROUGH THEN DEVELOPING EAST INTO THE GREAT PLAINS
SUNDAY INTO SUNDAY NIGHT. THIS SYSTEM WILL PUSH A STRONG COLD
FRONT ACROSS NORTH DAKOTA SUNDAY...ALONG WITH INCREASING CHANCES
FOR SNOW WITH THE FRONTAL PASSAGE FROM LATE SATURDAY NIGHT THROUGH
SUNDAY NIGHT. AT THIS TIME THE BEST UPPER LEVEL FORCING AND
ATMOSPHERIC MOISTURE LOOK TO TRACK SOUTH AND EAST OF THE NORTH
DAKOTA...SO DO NOT EXPECT MUCH SNOWFALL OVER THE SECOND HALF OF
THE WEEKEND. POSSIBLE WE COULD APPROACH ADVISORY LEVELS OF 3
INCHES...BUT AT THIS TIME AMOUNTS LOOKS TO FALL BELOW THAT MARK.
BEHIND THE COLD FRONT...ARCTIC AIR WILL SURGE SOUTH INTO THE
REGION RESULTING IN BELOW AVERAGE TEMPERATURES SUNDAY INTO EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 940 PM CST TUE NOV 12 2013
EXPECT VFR CONDITIONS AT ALL TAF SITES THROUGH THE FORECAST PERIOD
AT THIS TIME. SOUTH TO SOUTHWEST FLOW WILL BECOME WEST TO
NORTHWEST WEDNESDAY AND INCREASE WITH SUSTAINED WINDS AROUND 15 TO
20 KNOTS. DID MENTION A PERIOD OF LLWS AT KISN...KMOT AND KDIK
BEGINNING AROUND 08 UTC WITH GENERALLY LIGHT SOUTH TO SOUTHWEST
SURFACE FLOW...VEERING TO THE NORTHWEST AROUND 40 KNOTS AT 2000 FT
AGL. THIS WILL END AROUND 12-14 UTC AS SURFACE FLOW SHITS WEST AND
INCREASES. WILL KEEP AN EYE ON POSSIBLE STRATUS DEVELOPING IN AN
AREA OF INCREASED LOW LEVEL MOISTURE DUE TO MELTING SNOW IN THE
FAR SOUTHWEST AND NORTHWEST SOUTH DAKOTA AND ADVECTING NORTHWARD.
AT THIS TIME IT APPEARS MOISTURE WILL BE LIMITED AND NOTHING HAS
DEVELOPED AS OF YET. LAST FEW HRRR MODEL RUNS HAVE BACKED OFF ON
LOWER CEILINGS DEVELOPING IN THE SOUTHWEST AND LIFTING NORTHWARD.
SO STILL NO MENTION OF ANY LOWER CLOUDS AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 PM CST TUE NOV 12 2013
.UPDATE...
ISSUED AT 638 PM CST TUE NOV 12 2013
MAINLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS EVENING. LATEST SATELLITE IMAGERY SHOWS A SHORTWAVE OVER
ALBERTA WHICH WILL TRACK ACROSS SASKATCHEWAN AND INTO MANITOBA BY
EARLY WEDNESDAY MORNING. THE SURFACE LOW ASSOCIATED WITH THIS
WAVE WILL BRING A WARM FRONT ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT...FOLLOWED BY A WEAK DRY COLD FRONT LATE TONIGHT
AND WEDNESDAY. MAIN FORECAST ISSUE TONIGHT WILL BE TEMPERATURES.
THE TEMPERATURE AT WILLISTON DROPPED 10 DEGREES BETWEEN 5 AND 6 PM
CST. COULD SEE A FEW OTHER LOCALES DROP QUICKLY THIS EVENING...BUT
IN GENERAL...MILD SOUTHWEST FLOW WILL KEEP TEMPERATURES MUCH
WARMER TONIGHT WITH MID 20S TO MID 30S READINGS INSTEAD OF SINGLE
DIGITS AND LOW TEENS. MID AND HIGH LEVEL CLOUDINESS WILL ALSO
INCREASE FROM WEST TO EAST LATER THIS EVENING AND OVERNIGHT. NO
SIGNIFICANT CHANGES TO THE GOING FORECAST WERE WARRANTED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
THE MAIN HIGHLIGHTS IN THE SHORT TERM WILL BE A WARM FRONTAL PASSAGE
TONIGHT...MOVING FROM EASTERN MONTANA INTO CENTRAL NORTH DAKOTA.
THIS WILL THEN BE FOLLOWED BY A COLD FRONTAL PASSAGE WEDNESDAY
MORNING. DRY WEATHER WILL ACCOMPANY BOTH FRONTS. LOW LEVEL WARM AIR
ADVECTION CONTINUES OVERNIGHT INTO WEDNESDAY MORNING. WESTERLY WINDS
DEVELOPING IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY WILL
HELP MIX DOWN WARMER TEMPS ALOFT BEFORE THE COLD AIR ADVECTION
COMPLETELY ERODES THE WARM LAYER BY 00Z THURSDAY. HIGH TEMPERATURES
WEDNESDAY WILL REACH INTO THE MID AND UPPER 40S NORTH CENTRAL INTO
EAST CENTRAL...TO AROUND 50 DEGREES SOUTH CENTRAL...AND LOWER 50S
SOUTHWEST AND FAR SOUTH.
ANOTHER CONCERN IS THE POTENTIAL FOR STRATUS ASSOCIATED WITH THE
WARM AIR ADVECTION...ALONG AND AHEAD OF THE WARM FRONT THIS
EVENING AND INTO TONIGHT. THE NAM/RAP13 925MB RH FIELDS HAVE NOT
BEEN INITIALIZING WELL AT ALL TODAY...AS THEY HAVE BEEN INDICATING
A HIGH AMOUNT OF LOW LEVEL RH THIS AFTERNOON WHERE WE HAVE A CLEAR
SKY...THUS CANNOT USE THIS DATA FOR TONIGHT. THE HRRR REMAINS
CONSISTENT IN DEVELOPING A SWATH OF LESS THAN 500FT CEILINGS
NEAR/OVER THE SNOWCOVER IN SOUTH DAKOTA PER VISIBLE SATELLITE
IMAGERY BY AROUND 00Z WEDNESDAY. THIS SEEMS REASONABLE...BUT THE
RAPID DEVELOPMENT AND EXTENSIVE AREAL EXTENT SEEMS SUSPECT AT THIS
TIME. WILL BRIEF THE INCOMING EVENING SHIFT TO MONITOR THIS. IF
IT DOES MATERIALIZE...THEN BISMARCK TO JAMESTOWN AND ALL AREAS
SOUTH WOULD BE AFFECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
MAIN FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BE THE
PASSAGE OF TWO FRONTAL SYSTEMS.
THE EXTENDED PERIOD BEGINS WEDNESDAY NIGHT WITH AN EMBEDDED MID
LEVEL WAVE PUSHING EAST-SOUTHEAST ACROSS THE NORTHERN PLAINS
WITHIN A LONG WAVE TROUGH DEVELOPING FROM THE HUDSON BAY THROUGH
OUR LOCAL AREA SOUTHWEST INTO THE CENTRAL ROCKIES. WILL MAINTAIN
THE PERCENT AND COVERAGE OF CHANCES FOR PRECIPITATION WEDNESDAY
NIGHT...AND INTO THE DAYTIME HOURS THURSDAY. BUFFER SOUNDINGS
INDICATE WE WILL EITHER SEE RAIN OR SNOW DEPENDING ON SURFACE
TEMPERATURES...WITH THE CAA ADVERTISED IN THE MID TO UPPER LEVELS
OF THE ATMOSPHERE.
WE DRY OUT THURSDAY NIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE
DAKOTAS. FLOW ALOFT TRANSITIONS TO MORE ZONAL AS A VERY BROAD
TROUGH DEVELOPS ACROSS ALL OF NORTH AMERICA. STRONG EMBEDDED
ENERGY PUSHING SOUTHEAST ALONG THE CANADIAN PACIFIC COAST WILL
AMPLIFY THE TROUGH OVER THE WESTERN ROCKIES SATURDAY INTO SATURDAY
NIGHT...WITH THE TROUGH THEN DEVELOPING EAST INTO THE GREAT PLAINS
SUNDAY INTO SUNDAY NIGHT. THIS SYSTEM WILL PUSH A STRONG COLD
FRONT ACROSS NORTH DAKOTA SUNDAY...ALONG WITH INCREASING CHANCES
FOR SNOW WITH THE FRONTAL PASSAGE FROM LATE SATURDAY NIGHT THROUGH
SUNDAY NIGHT. AT THIS TIME THE BEST UPPER LEVEL FORCING AND
ATMOSPHERIC MOISTURE LOOK TO TRACK SOUTH AND EAST OF THE NORTH
DAKOTA...SO DO NOT EXPECT MUCH SNOWFALL OVER THE SECOND HALF OF
THE WEEKEND. POSSIBLE WE COULD APPROACH ADVISORY LEVELS OF 3
INCHES...BUT AT THIS TIME AMOUNTS LOOKS TO FALL BELOW THAT MARK.
BEHIND THE COLD FRONT...ARCTIC AIR WILL SURGE SOUTH INTO THE
REGION RESULTING IN BELOW AVERAGE TEMPERATURES SUNDAY INTO EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 638 PM CST TUE NOV 12 2013
EXPECT VFR CONDITIONS AT ALL TAF SITES THROUGH THE FORECAST PERIOD
AT THIS TIME. SOUTH TO SOUTHWEST FLOW WILL BECOME WEST TO
NORTHWEST WEDNESDAY AND INCREASE WITH SUSTAINED WINDS AROUND 15 TO
20 KNOTS. DID MENTION A PERIOD OF LLWS AT KISN...KMOT AND KDIK
BEGINNING AROUND 08 UTC WITH GENERALLY LIGHT SOUTH TO SOUTHWEST
SURFACE FLOW...VEERING TO THE NORTHWEST AROUND 40 KNOTS AT 2000 FT
AGL. THIS WILL END AROUND 12-14 UTC AS SURFACE FLOW SHITS WEST AND
INCREASES. WILL KEEP AN EYE ON POSSIBLE STRATUS DEVELOPING IN AN
AREA OF INCREASED LOW LEVEL MOISTURE DUE TO MELTING SNOW IN THE
FAR SOUTHWEST AND NORTHWEST SOUTH DAKOTA AND ADVECTING NORTHWARD.
AT THIS TIME IT APPEARS MOISTURE WILL BE LIMITED SO WILL NOT
MENTION ANY LOWER CLOUDS AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
111 PM CST MON NOV 11 2013
.UPDATE...
ISSUED AT 111 PM CST MON NOV 11 2013
LOW CLOUD STREAMERS HAVE COMBINED AND BECOME A BIT MORE CELLULAR
IN NATURE PER LATEST VISIBLE SATELLITE IMAGERY...BUT STILL BLANKET
MOST OF THE FORECAST AREA WITH OVERCAST CONDITIONS. MOST OF THE
DEVILS LAKE BASIN REMAINS SUNNY...BUT INCREASED SKY GRIDS THE REST
OF THE AFTERNOON FOR ALL OTHER AREAS. CLOUDS NOT LIKELY TO
DISSIPATE AND/OR MOVE OUT OF THE REGION UNTIL LOW-LEVEL WINDS
SHIFT OT THE WEST LATE THIS AFTERNOON AND EVENING AS HIGH PRESSURE
PUSHES EAST. REST OF THE FORECAST IN GOOD SHAPE WITH NO OTHER
CHANGES AT THIS TIME.
UPDATE ISSUED AT 1017 AM CST MON NOV 11 2013
CHALLENGES FOR THE MORNING UPDATE INCLUDE CLOUD AND TEMPERATURE
TRENDS. VISIBLE SATELLITE SHOWING TWO LARGE LOW CLOUD STREAMERS
ACROSS EASTERN NORTH DAKOTA AND NORTHWEST MN ORIGINATING FROM LAKE
MANITOBA AND LAKE WINNIPEG RESPECTIVELY. THE FAR WESTERN EDGE OF
THE DEVILS LAKE BASIN IS MOSTLY SUNNY AND THERE IS A GREATER MIX
OF SUN AND CLOUDS FROM WINNIPEG TO FERGUS FALLS IN-BETWEEN THE TWO
STREAMERS. RAP 925 HPA RH SUGGESTS THESE CLOUDS WILL HOLD TOGETHER
FOR MUCH OF THE DAY AND WITH PERSISTENT NORTH-NORTHWEST FLOW...DO
NOT EXPECT MUCH EXPANSION IN THE EAST-WEST DIRECTION. AS SUBSIDENCE
INCREASES WITH BUILDING SURFACE HIGH PRESSURE THROUGH THE DAY...
EXPECT A VERY SLOW EROSION OF THE CLOUDS. INCREASED SKY COVER
MOST AREAS IN THE GRIDS.
GIVEN WEAK COLD AIR ADVECTION FOR MUCH OF THE DAY...TEMPERATURES
WILL BE MORE DEPENDENT ON CLOUD COVER. A COLD DAY FOR SURE...BUT
CLOUDS MAY KEEP TEMPERATURES FROM RISING MUCH ABOVE CURRENT
VALUES. TWEAKED THE DIURNAL CURVE BASED ON LATEST OBSERVATIONS...
BUT DO NOT THINK AFTERNOON HIGHS WILL TOP 20 DEGREES. REST OF THE
FORECAST IN GOOD SHAPE WITH NO MAJOR CHANGES AT THIS TIME.
UPDATE ISSUED AT 620 AM CST MON NOV 11 2013
NO CHANGES PLANNED FOR THIS UPDATE...WITH FORECAST ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 325 AM CST MON NOV 11 2013
THE MAIN CHALLENGE WILL BE TEMPS AND CLOUD TRENDS...WITH ARCTIC
AIRMASS IN PLACE INITIALLY THEN A WARMING TREND. MODELS REMAIN IN
VERY GOOD AGREEMENT...AND THE NAM SEEMS TO HAVE A BETTER HANDLE ON
LOW LEVEL MOISTURE AND CLOUDS.
FOR TODAY...EXPECT A COLD DAY WITH MOST AREAS NOT GETTING OUT OF
THE TEENS. THERE WILL BE LINGERING CLOUDS MAINLY IN THE NORTH AND
EAST...WITH SOME LAKE AFFECT SNOW SHOWERS DOWNWIND OF LAKE OF THE WOODS
NEAR BAUDETTE DURING THE MORNING. THE FETCH IS A BIT TOO WESTERLY
FOR MUCH OF ANY ACCUMULATION THOUGH...BUT SOMETHING TO MONITOR IF
WINDS TURN A BIT MORE NORTHERLY.
FOR TONIGHT...ARCTIC HIGH PRESSURE AROUND 1042MB WILL MOVE FROM NW
TO SE THROUGH THE REGION. EXPECT A VERY COLD NIGHT...WITH SOME
AREAS IN NE ND A FEW DEGREES BELOW ZERO AND AROUND ZERO IN GRAND
FORKS. THE RECORD LOWS FOR TUE MORNING ARE -9 AT THE NWS IN GRAND
FORKS...-5 AT GFK AND -7 FARGO. THEREFORE...LOWS WON/T FALL TO
RECORD LEVELS...BUT -5 AT THE AIRPORT IN GFK COULD BE APPROACHED WITH
A DUSTING OF SNOW ON THE GROUND.
ON TUESDAY...AN UPPER LEVEL RIDGE WILL BUILD IN AND STRONG MID
LEVEL WAA WILL BEGIN. TEMPS WILL WARM ABOUT 10-15 DEGREES FROM
TODAYS HIGHS...WITH PLENTY OF SUNSHINE FOR MOST AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM CST MON NOV 11 2013
FOR WEDNESDAY...EVEN WARMER AIR AND WESTERLY SFC FLOW WILL MOVE
INTO THE AREA. EXPECT TEMPS TO WARM INTO THE LOW/MID 40S FOR THE
ENTIRE REGION. GIVEN THE FAVORABLE WEST SFC WINDS AND 850MB TEMPS
WARMING TO AROUND +10C BY 18Z WED...SOME AREAS COULD EVEN APPROACH
50 WITH NO SNOW COVER TO SPEAK OF.
FOR THURSDAY-SUNDAY...THE UPPER FLOW BECOMES A BIT MORE
NORTHWESTERLY ON THURSDAY AS AN UPPER SHORTWAVE TROUGH SKIRTS THE
CANADIAN BORDER. WINDS WILL SHIFT NORTHWEST BEHIND A WEAK COLD
FRONT HELPING TO KNOCK TEMPS DOWN A BIT FROM WEDNESDAY. ALTHOUGH
FORCING IS WEAK...A BIT OF VERY LIGHT PRECIP IS POSSIBLE.
MODEL DIFFERENCES SIGNIFICANTLY INCREASE LATE IN THE WEEK INTO NEXT
WEEKEND. WHILE AN UPPER TROUGH IS EXPECTED TO DEVELOP FROM THE
ROCKIES INTO THE PLAINS...THE ECMWF HAS BEEN SLOWER AND MORE
AMPLIFIED WITH ITS EVOLUTION THAN THE GFS OVER THE PAST FEW RUNS.
THIS SOLUTION WOULD RESULT IN WELL ABOVE NORMAL TEMPS FOR MUCH OF
NEXT WEEKEND BEFORE A STRONGER COLD SURGE AND BETTER PRECIP CHANCES
ARRIVE. THE 00Z GFS...ON THE OTHER HAND...BRINGS THE COLD FRONT
THROUGH ON SATURDAY...WITH GENERALLY SEASONABLE TEMPS. SIGNIFICANT
SPREAD IS EVIDENT AMONG GFS ENSEMBLE MEMBERS DURING THIS TIME.
THUS...FORECAST CONFIDENCE IS VERY LOW...AND WILL NOT DEVIATE MUCH
FROM CONTINUITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1017 AM CST MON NOV 11 2013
MVFR CIGS EMANATING FROM LAKE WINNIPEG STREAMING DOWN AND COVERING
A REGION ESSENTIALLY BOUNDED BY KDVL TO THE WEST AND KBJI TO THE
EAST. PLENTY OF COVER UPSTREAM TO KEEP MVFR IN PLACE THROUGH MID
AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...DK
LONG TERM...DK/MAKOWSKI
AVIATION...WJB
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1017 AM CST MON NOV 11 2013
.UPDATE...
ISSUED AT 1017 AM CST MON NOV 11 2013
CHALLENGES FOR THE MORNING UPDATE INCLUDE CLOUD AND TEMPERATURE
TRENDS. VISIBLE SATELLITE SHOWING TWO LARGE LOW CLOUD STREAMERS
ACROSS EASTERN NORTH DAKOTA AND NORTHWEST MN ORIGINATING FROM LAKE
MANITOBA AND LAKE WINNIPEG RESPECTIVELY. THE FAR WESTERN EDGE OF
THE DEVILS LAKE BASIN IS MOSTLY SUNNY AND THERE IS A GREATER MIX
OF SUN AND CLOUDS FROM WINNIPEG TO FERGUS FALLS IN-BETWEEN THE TWO
STREAMERS. RAP 925 HPA RH SUGGESTS THESE CLOUDS WILL HOLD TOGETHER
FOR MUCH OF THE DAY AND WITH PERSISTENT NORTH-NORTHWEST FLOW...DO
NOT EXPECT MUCH EXPANSION IN THE EAST-WEST DIRECTION. AS SUBSIDENCE
INCREASES WITH BUILDING SURFACE HIGH PRESSURE THROUGH THE DAY...
EXPECT A VERY SLOW EROSION OF THE CLOUDS. INCREASED SKY COVER
MOST AREAS IN THE GRIDS.
GIVEN WEAK COLD AIR ADVECTION FOR MUCH OF THE DAY...TEMPERATURES
WILL BE MORE DEPENDENT ON CLOUD COVER. A COLD DAY FOR SURE...BUT
CLOUDS MAY KEEP TEMPERATURES FROM RISING MUCH ABOVE CURRENT
VALUES. TWEAKED THE DIURNAL CURVE BASED ON LATEST OBSERVATIONS...
BUT DO NOT THINK AFTERNOON HIGHS WILL TOP 20 DEGREES. REST OF THE
FORECAST IN GOOD SHAPE WITH NO MAJOR CHANGES AT THIS TIME.
UPDATE ISSUED AT 620 AM CST MON NOV 11 2013
NO CHANGES PLANNED FOR THIS UPDATE...WITH FORECAST ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 325 AM CST MON NOV 11 2013
THE MAIN CHALLENGE WILL BE TEMPS AND CLOUD TRENDS...WITH ARCTIC
AIRMASS IN PLACE INITIALLY THEN A WARMING TREND. MODELS REMAIN IN
VERY GOOD AGREEMENT...AND THE NAM SEEMS TO HAVE A BETTER HANDLE ON
LOW LEVEL MOISTURE AND CLOUDS.
FOR TODAY...EXPECT A COLD DAY WITH MOST AREAS NOT GETTING OUT OF
THE TEENS. THERE WILL BE LINGERING CLOUDS MAINLY IN THE NORTH AND
EAST...WITH SOME LAKE AFFECT SNOW SHOWERS DOWNWIND OF LAKE OF THE WOODS
NEAR BAUDETTE DURING THE MORNING. THE FETCH IS A BIT TOO WESTERLY
FOR MUCH OF ANY ACCUMULATION THOUGH...BUT SOMETHING TO MONITOR IF
WINDS TURN A BIT MORE NORTHERLY.
FOR TONIGHT...ARCTIC HIGH PRESSURE AROUND 1042MB WILL MOVE FROM NW
TO SE THROUGH THE REGION. EXPECT A VERY COLD NIGHT...WITH SOME
AREAS IN NE ND A FEW DEGREES BELOW ZERO AND AROUND ZERO IN GRAND
FORKS. THE RECORD LOWS FOR TUE MORNING ARE -9 AT THE NWS IN GRAND
FORKS...-5 AT GFK AND -7 FARGO. THEREFORE...LOWS WON/T FALL TO
RECORD LEVELS...BUT -5 AT THE AIRPORT IN GFK COULD BE APPROACHED WITH
A DUSTING OF SNOW ON THE GROUND.
ON TUESDAY...AN UPPER LEVEL RIDGE WILL BUILD IN AND STRONG MID
LEVEL WAA WILL BEGIN. TEMPS WILL WARM ABOUT 10-15 DEGREES FROM
TODAYS HIGHS...WITH PLENTY OF SUNSHINE FOR MOST AREAS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 AM CST MON NOV 11 2013
FOR WEDNESDAY...EVEN WARMER AIR AND WESTERLY SFC FLOW WILL MOVE
INTO THE AREA. EXPECT TEMPS TO WARM INTO THE LOW/MID 40S FOR THE
ENTIRE REGION. GIVEN THE FAVORABLE WEST SFC WINDS AND 850MB TEMPS
WARMING TO AROUND +10C BY 18Z WED...SOME AREAS COULD EVEN APPROACH
50 WITH NO SNOW COVER TO SPEAK OF.
FOR THURSDAY-SUNDAY...THE UPPER FLOW BECOMES A BIT MORE
NORTHWESTERLY ON THURSDAY AS AN UPPER SHORTWAVE TROUGH SKIRTS THE
CANADIAN BORDER. WINDS WILL SHIFT NORTHWEST BEHIND A WEAK COLD
FRONT HELPING TO KNOCK TEMPS DOWN A BIT FROM WEDNESDAY. ALTHOUGH
FORCING IS WEAK...A BIT OF VERY LIGHT PRECIP IS POSSIBLE.
MODEL DIFFERENCES SIGNIFICANTLY INCREASE LATE IN THE WEEK INTO NEXT
WEEKEND. WHILE AN UPPER TROUGH IS EXPECTED TO DEVELOP FROM THE
ROCKIES INTO THE PLAINS...THE ECMWF HAS BEEN SLOWER AND MORE
AMPLIFIED WITH ITS EVOLUTION THAN THE GFS OVER THE PAST FEW RUNS.
THIS SOLUTION WOULD RESULT IN WELL ABOVE NORMAL TEMPS FOR MUCH OF
NEXT WEEKEND BEFORE A STRONGER COLD SURGE AND BETTER PRECIP CHANCES
ARRIVE. THE 00Z GFS...ON THE OTHER HAND...BRINGS THE COLD FRONT
THROUGH ON SATURDAY...WITH GENERALLY SEASONABLE TEMPS. SIGNIFICANT
SPREAD IS EVIDENT AMONG GFS ENSEMBLE MEMBERS DURING THIS TIME.
THUS...FORECAST CONFIDENCE IS VERY LOW...AND WILL NOT DEVIATE MUCH
FROM CONTINUITY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1017 AM CST MON NOV 11 2013
MVFR CIGS EMANATING FROM LAKE WINNIPEG STREAMING DOWN AND COVERING
A REGION ESSENTIALLY BOUNDED BY KDVL TO THE WEST AND KBJI TO THE
EAST. PLENTY OF COVER UPSTREAM TO KEEP MVFR IN PLACE THROUGH MID
AFTERNOON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...DK
LONG TERM...DK/MAKOWSKI
AVIATION...WJB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
730 PM EST TUE NOV 12 2013
.SYNOPSIS...
LINGERING SNOW SHOWERS TONIGHT IN LOW LEVEL THERMAL TROF.
STRONG HIGH PRESSURE BUILDS IN AND DOMINATES FOR WEDNESDAY INTO
THURSDAY. WARMING TREND LATE WEEK THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LINGERING SNOW SHOWERS IN THE LOW LEVEL THERMAL TROF SEEM TO BE
WEAKENING...AT LEAST IN TERMS OF THE NUMBER OF STRONGER CELLS AND
THEIR PEAK DBZ REFLECTIVITY RETURNS. YET...A LOCAL COATING OF SNOW
STILL POSSIBLE UNDER ANY OF THESE SHOWERS.
NO REASON TO ADJUST POPS MUCH...SINCE WE HAD RELATIVELY HIGH POPS
LINGERING INTO THIS EVENING.
DID HOLD ONTO SOME SLIGHT CHANCE POPS ALONG THE I-79 CORRIDOR FOR
06Z TO 08Z...AND UNTIL DAWN IN OUR CENTRAL WV MOUNTAINS.
EXTENT OF THE CLOUD COVER IS HARD TO FIGURE FOR 06Z THROUGH 14Z.
FORECAST SOUNDINGS EVEN TRY TO REFORM CLOUDS DURING THE PREDAWN.
DID INCREASE MINIMUM TEMPERATURE TONIGHT BASED ON THOSE CLOUDS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
QUIET PERIOD WITH ONLY MINOR TEMPERATURE ADJUSTMENTS MADE TO ONGOING
FORECAST PER LATEST GUIDANCE.
SHOULD BE AN ESSENTIALLY CLEAR SKY WEDNESDAY NIGHT WITH SFC HIGH
PRESSURE LOCATED TO OUR S/SW. OVERNIGHT MINS A BIT TRICKY WITH
COMPETING FORCES AT WORK. CLEAR SKIES...LOW DEWPOINTS...AND MAX
TEMPS WEDNESDAY ONLY IN THE MID/UPPER 30S LOWLANDS WOULD SUGGEST
MINS CLOSER TO COOLER GUIDANCE SUITE. A FAIRLY DECENT BOUNDARY LAYER
WIND HOWEVER ALONG WITH WARM ADVECTION AT 850MB SHOULD LIMIT MAX
COOLING POTENTIAL HOWEVER. SO QUESTION BECOMES EACH SITE/S ABILITY
TO DECOUPLE. IN THE END...DECIDED TO KEEP INHERITED MINS ACROSS
ROUGHLY THE WESTERN THIRD OF THE AREA AND LOWER MINS JUST SLIGHTLY
ACROSS THE CENTRAL AND EASTERN PARTS OF THE AREA WITH LATEST
GUIDANCE...YET STILL REMAINED ON THE WARM SIDE OF GUIDANCE ON THE
WHOLE AS WAS THE TREND WITH PREV FORECAST. EXPECT THE RIDGE TOPS AS
WELL AS THE EASTERN MOUNTAINS TO SEE A `WARMER` NIGHT WITH
AFOREMENTIONED WARM ADVECTION AT 850MB.
AREA REMAINS UNDER W/SW FLOW ALOFT WITH CONTINUED S/SW SFC WINDS AS
SFC HIGH PRESSURE MOVES OFF THE SE ATLANTIC COASTLINE. SKIES WILL
REMAIN MOSTLY SUNNY WITH MAX TEMPS REBOUNDING NICELY INTO THE UPPER
40S NORTHERN LOWLANDS AND LOWER 50S SOUTHERN LOWLANDS. WILL BE A BIT
ON THE BREEZY SIDE...MAINLY ACROSS THE NORTHERN ZONES AND EASTERN
HIGH TERRAIN. COULD BE A BIT OF ENHANCED FIRE DANGER CONCERN AS WELL
WITH LOW RH/S. ACROSS THE LOWLANDS...LOOKS LIKE THE LOWEST RH/S
DON/T OVERLAP WELL WITH THE STRONGER WINDS SO THREAT APPEARS MINIMAL
HERE. SOME VERY DRY AIR ALOFT HOWEVER MAY ALSO RESULT IN RH VALUES
DOWN AROUND THE 25-30 PERCENT RANGE OVER THE HIGH ELEVATIONS WHERE
AFOREMENTIONED GUSTS AROUND 20-25KTS ARE POSSIBLE. YET...RECENT SNOW
MAY TAPER THIS THREAT AS WELL.
THURSDAY NIGHT SHOULD BE A BIT WARMER WITH SOME INCREASE IN HIGH
LEVEL CLOUDS. VERY LITTLE CHANGE HERE WITH INHERITED MINS GENERALLY
IN THE LOWER 30S LOWLANDS. AS WITH PREVIOUS NIGHT...EXPECT A FAIRLY
GOOD TEMP GRADIENT BTWN THE HIGH PEAKS AND SHELTERED VALLEYS OF THE
EASTERN MOUNTAINS.
ANOTHER NICE DAY IN STORE FOR FRIDAY...WITH A CONTINUED WARMUP AS
WELL WITH ONLY AN INCREASE IN MAINLY HIGH CLOUDS EXPECTED. NUDGED
MAX TEMPS UP JUST SLIGHTLY PER LATEST 850MB/925MB TEMPS YET REMAINED
ON THE COOLER SIDE OF GUIDANCE. EXPECT MAX TEMPS FRIDAY INTO THE
MID/UPPER 50S FOR THE LOWLANDS...AND 40S FOR THE EASTERN MOUNTAINS.
RH VALUES ARE NOT EXPECTED TO BE QUITE AS LOW AS THURSDAY/S...NOR
WILL WIND GUST SPEEDS...SO NO FIRE WEATHER CONCERNS ARE ANTICIPATED
ON FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
DECENT AGREEMENT IN THE EXTENDED AMONGST THE MODELS WHICH FEATURES
UPR RIDGING BUILDING ACROSS SE STATES OVER THE WEEKEND WITH ANOTHER
DEEP AMPLIFICATION OF UPR TROF MOVING INTO REGION EARLY NEXT WEEK.
TRIED TO KEEP MOST DRY FOR SATURDAY GIVEN GOOD DOWNSLOPING FLOW.
SUNDAY...THINGS BECOME A LITTLE MURKIER WITH A PIECE OF ENERGY IN
INCREASINGLY DIFFLUENT FLOW. FEEL BEST CHC FOR SHRA WILL BE ALONG
AND ESPECIALLY W OF OH RVR ON SUNDAY. THUS HAVE HIGH CHC ACROSS SE
OH FOR SAID TIME WITH LOW CHC ELSEWHERE. SFC LOW TRACK THRU W LAKES
HEADING INTO MONDAY AS UPR TROF SHARPENS. THIS WILL ALLOW FOR A
STRONG COLD FRONT TO MOVE THRU MONDAY NIGHT OR EARLY TUES WITH
INCREASING CHC FOR SHRA MONDAY AND MONDAY NIGHT. BUMPED UP POPS INTO
LKLY TO FOLLOW THIS FEATURE. STRONG CAA COMMENCES LATER ON TUE WITH
ANY LINGERING SHRA CHANGING TO SHSN ACROSS THE MTNS AND PERHAPS ADJ
LOWLAND AREAS BEFORE ATMOS COLUMN DRIES OUT TUE NIGHT. SFC HIGH
BUILDS IN FOR WED AS UPR TROF LIFTS OUT.
FOR TEMPS...GENERALLY FOLLOWED HPC WITH SOME INCORPORATION OF GFS
NUMBERS TO HIT WAA NIGHTTIME HRS AND POST FRONTAL CAA BETTER.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
LINGERING SNOW SHOWERS WITH SOME LOCAL AND BRIEF VSBY 1 TO 3 MILES
MAINLY CKB TO CRW ON EAST INTO THE WV MOUNTAINS THROUGH 06Z.
MAIN ISSUE FOR THE LATE NIGHT AND EARLY MORNING HOURS...06Z TO
14Z...IS THE EXTENT AND HEIGHT OF THE CEILINGS. RAP INDICATING THE
CEILINGS COULD REFORM AND EVEN LOWER DURING THE PREDAWN.
DID HOLD ONTO SOME 2 TO 3 THSD FT CEILINGS IN THE MOUNTAIN
COUNTIES...WITH MAINLY SCATTERED CLOUDS FURTHER WEST TOWARD THE OHIO
RIVER VALLEY.
SOME 5 TO 6 MILES IN HAZE COULD FORM FOR THE 08Z TO 13Z TIME
FRAME...MAINLY NEAR URBAN AREAS.
ANY LINGERING STRATOCUMULUS SHOULD BE DISSIPATING 18Z WEDNESDAY TO
00Z AS MIXING OCCURS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: EXTENT OF CEILINGS DURING THE 06Z TO 14Z
WEDNESDAY TIME FRAME IS IN QUESTION. COULD BE MORE OR LESS THAN
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.
DATE WED
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY H H M H M H H H H M M M
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H M M M M M M M
EKN CONSISTENCY H M M M M L L L L L L L
PKB CONSISTENCY H H H H M H H H H M M M
CKB CONSISTENCY M M M M M M M M M M M M
AFTER 00Z THURSDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/ARJ
NEAR TERM...KTB
SHORT TERM...TRM
LONG TERM...50
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1147 PM CST SUN NOV 10 2013
.AVIATION...
FOR THE 06Z TAFS...MONITORING FOR THE DEVELOPMENT OF FOG THROUGH
MONDAY MORNING IS THE PRIMARY AVIATION WEATHER CONCERN OVER THE
NEXT 24 HOURS. THE TIMING OF A STRONG COLD FRONT EXPECTED TO MOVE
INTO NORTH TEXAS EARLY TUESDAY MORNING WAS PLACED AT THE END OF
THE DFW TAF.
LOW LEVEL CLOUD COVER HAD CLEARED OUT EARLIER THIS EVENING AND WAS
SHOWING NO SIGNS OF REDEVELOPMENT ACROSS THE AREA AT 0530Z. CLEAR
SKIES ALLOWED TEMPERATURES TO DROP FASTER THAN EXPECTED LATE THIS
EVENING...BRINGING 11 PM/05Z TEMPERATURES DOWN TO WITHIN A FEW
DEGREES OF OBSERVED DEW POINTS ACROSS MUCH OF NORTH TEXAS.
TEMPERATURES ARE LIKELY TO FALL CLOSE TO THIS AFTERNOONS DEW
POINTS WHICH TYPICALLY REPRESENT THE CROSSOVER TEMPERATURE WHEN
CONCERNED WITH RADIATIONAL FOG FORECASTING.
BASED ON OUR 00Z RAOB AND RAP FORECAST SOUNDINGS TONIGHT...LOW-
LEVEL MOISTURE DECREASES WITH HEIGHT...SO DO NOT EXPECT AREAS OF
DENSE FOG TO DEVELOP NEAR AREA TAF SITES THROUGH EARLY MONDAY
MORNING. REGARDLESS...SOME SHALLOW GROUND FOG IS LIKELY NEAR ALL
AREA TAF SITES...SO WENT AHEAD WITH MVFR VSBYS MENTIONED IN THE
10-15Z WINDOW FOR THE DFW AREA...AND 08 TO 15Z WINDOW FOR WACO
WITH THESE TAFS.
IT IS POSSIBLE THAT THE DECREASE IN MOISTURE WITH HEIGHT IS TOO
GREAT TO ALLOW FOR FOG TO DEVELOP...AND IF THAT IS THE CASE FOG
CAN BE REMOVED IN THE 09Z AMENDMENTS. IT IS ALSO POSSIBLE THAT
VSBYS MAY FALL TO IFR AT TIMES IF FOG DEVELOPS AS LIGHT WINDS MAY
LOCALLY INCREASE THE DEPTH OF THE SHALLOW FOG. AT THIS POINT WILL
HAVE TO MONITOR AND ADJUST THE TAFS AS NECESSARY TO GAUGE IMPACTS
TO THE MORNING FLIGHT SCHEDULE.
AS MENTIONED ABOVE...MENTIONED THE PASSAGE OF A STRONG COLD FRONT
AT THE END OF THE DFW TAF. THIS FRONT IS EXPECTED TO MOVE THROUGH
THE AREA EARLY TUESDAY MORNING...MOVING ACROSS DFW BY 10Z.
CAVANAUGH
&&
.PREV DISCUSSION... /ISSUED 311 PM CST SUN NOV 10 2013/
STRATUS CONTINUES TO SLOWLY ERODE FROM EAST TO WEST OVER THE AREA
AND MOST OF THE REGION WILL BE CLEAR BY THE EVENING HOURS. STRATUS
WILL TEND TO REDEVELOP FROM WEST TO EAST...LIKELY ENCOMPASSING THE
WESTERN ZONES BY MIDNIGHT AND REACHING THE I-35 CORRIDOR BEFORE
SUNRISE. AS A RESULT...RADIATIONAL COOLING WILL BE FAIR TO GOOD
ACROSS THE CENTRAL AND EASTERN ZONES TONIGHT WHERE LOW TEMPS WILL
DROP DOWN INTO THE LOW TO MID 40S...WITH THE EXCEPTION OF THE
URBAN HEAT ISLAND AROUND THE METROPLEX. MOISTURE DEPTH LOOKS A BIT
TOO SHALLOW FOR FOG TONIGHT...BUT WOULD NOT BE SURPRISED TO SEE
SOME GROUND FOG ACROSS THE NORTHEAST ZONES. CLOUDS SHOULD HAVE AN
EASIER TIME ERODING MONDAY WITH PARTLY SUNNY CONDITIONS EXPECTED
BY AFTERNOON. HIGHS SHOULD REACH THE LOW 70S FOR MOST AREAS.
THE STRONG COLD FRONT WILL ARRIVE EARLY TUESDAY MORNING. HOWEVER
WINDS WILL SHIFT TO THE NORTH SOME 3 TO 6 HOURS AHEAD OF THE TRUE
FRONTAL PASSAGE. TEMPERATURES WILL DROP STEADILY INTO THE 50S
DURING THE EARLY MORNING HOURS COMPLIMENTS OF RADIATIONAL COOLING
AND WEAK COLD ADVECTION. THE TRUE FRONT WILL MOVE THROUGH AROUND
OR JUST AFTER SUNRISE OVER THE NORTHERN ZONES AND AROUND MID TO
LATE MORNING IN THE SOUTHERN ZONES. TEMPERATURES BEHIND THIS FRONT
WILL DROP INTO THE 40S WITH SKIES CLOUDING OVER. LOW LEVEL
MOISTURE TRAPPED BELOW THE FRONTAL INVERSION WILL RESULT IN POST
FRONTAL CLOUDS AND SOME ISOLATED SHOWERS OR SPRINKLES TUESDAY
MORNING. SKIES SHOULD CLEAR FROM NORTH TO SOUTH DURING THE MID
AFTERNOON TO EVENING HOURS. WINDS AT 15 TO 25 MPH WILL PUT WIND
CHILLS TUESDAY AFTERNOON/EVENING IN THE 30S FOR MOST OF THE AREA.
HIGH PRESSURE WILL RAPIDLY BUILD INTO THE REGION TUESDAY NIGHT
WITH WINDS BECOMING NEARLY CALM OVER THE NORTHWEST ZONES. LOWS
THERE WILL DIP INTO THE LOW TO MID 20S. OTHERWISE EXPECT LOWS TO
RANGE FROM THE UPPER 20S TO LOWER 30S WITH ALL BUT THE FAR
SOUTHEAST ZONES EXPERIENCING THEIR FIRST FREEZE BY WEDNESDAY
MORNING. THE FREEZE WARNING WILL LIKELY BE ISSUED MONDAY
AFTERNOON. THE CORE OF THE COLD AIRMASS WILL BE OVERHEAD WEDNESDAY
AFTERNOON WITH GENERALLY LIGHT WINDS AND SOME CIRRUS CLOUD COVER
EXPECTED. HIGHS WILL STRUGGLE TO WARM...AND MOST AREAS WILL STAY
IN THE 40S. BY WEDNESDAY NIGHT THE SURFACE RIDGE WILL MOVE EAST
WITH SOUTH WINDS RETURNING AND INCREASING HIGH CLOUDS LIMITING
RADIATIONAL COOLING OVER THE WESTERN AND CENTRAL ZONES. THE
EASTERN ZONES WILL BE THE COLDEST...AND THE SOUTHEAST ZONES WILL
HAVE A SHOT AT A FIRST FREEZE IF THEY MISS OUT WEDNESDAY MORNING.
CLOUDS AND MOISTURE WILL INVADE THE AREA THURSDAY AS A SHORTWAVE
TROUGH MOVES OVER THE REGION THURSDAY NIGHT. MODEL GUIDANCE IS
SHOWING ENOUGH MOISTURE AND INSTABILITY FOR ELEVATED
SHOWERS...MUCH OF WHICH WILL BE VIRGA INITIALLY...BUT ENOUGH
COLUMN SATURATION SHOULD OCCUR BY THURSDAY AFTERNOON AND EVENING
FOR THIS TO REACH THE SURFACE. HAVE ADDED SLIGHT CHANCES OF RAIN
THURSDAY AFTERNOON AND WILL CONTINUE THESE LOW POPS INTO THURSDAY
NIGHT. THE FORECAST HIGHS THURSDAY MAY END UP BEING TOO WARM...BUT
HAVE GONE COLDER THAN ALL OF THE GUIDANCE WITH LOW TO MID 50S.
MEANWHILE...WITH CLOUDS AND SOUTHERLY FLOW CONTINUING INTO
THURSDAY NIGHT...EXPECT TEMPS TO BE NEARLY STEADY. HAVE RAISED
THESE INTO THE MID TO UPPER 40S TO ACCOUNT FOR THIS.
ANOTHER STRONGER SHORTWAVE TROUGH WILL APPROACH THE AREA FRIDAY
AND MOVE THROUGH THE REGION SATURDAY. WARM ADVECTION WILL CONTINUE
WITH SURFACE TEMPS CONTINUING TO GRADUALLY MODERATE...POSSIBLY
EVEN RISING DURING THE NIGHT FRIDAY NIGHT. THERE IS ENOUGH
INSTABILITY FOR THUNDERSTORMS BY FRIDAY NIGHT AND POPS OF 30 TO 40
PERCENT LOOK GOOD BEFORE THE SYSTEM CLEARS US FROM WEST TO EAST ON
SATURDAY. TEMPS BY SATURDAY SHOULD BE IN THE 60S OR 70S.
THE ECMWF CONTINUES TO HOLD MORE UPPER LEVEL ENERGY BACK TO THE
WEST THIS WEEKEND...WHICH WOULD RESULT IN CONTINUED CLOUD
COVER...RAIN CHANCES...AND WARM SOUTHERLY WINDS INTO SUNDAY AND
MONDAY. THE GFS SAYS IS WEAKER WITH THIS ENERGY AND IS DRIER. WILL
CONTINUE TO SIDE WITH THE ECMWF AND FEATURE LOW POPS IN THE
FORECAST AS IT HAS PROVED TO BE SUPERIOR TO THE GFS LATELY.
OTHERWISE ANOTHER STRONG COLD FRONT WITH FREEZING TEMPERATURES
LOOKS LIKELY BY MONDAY OR TUESDAY OF NEXT WEEK.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 50 71 44 51 31 / 0 0 10 10 0
WACO, TX 46 71 51 57 31 / 0 0 5 10 0
PARIS, TX 44 69 45 50 26 / 0 0 10 10 0
DENTON, TX 45 71 41 50 24 / 0 0 20 10 0
MCKINNEY, TX 42 70 43 52 26 / 0 0 10 10 0
DALLAS, TX 50 71 45 52 31 / 0 0 10 10 0
TERRELL, TX 45 71 46 53 30 / 0 0 10 10 0
CORSICANA, TX 46 72 51 55 31 / 0 0 10 10 0
TEMPLE, TX 46 72 51 59 32 / 0 0 5 10 0
MINERAL WELLS, TX 48 71 43 50 26 / 0 0 20 10 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1144 PM CST SUN NOV 10 2013
.AVIATION...
KLBB DEWPOINT DEPRESSION NEAR ZERO THIS HOUR AND VERY CLOSE TO
DEVELOPING STRATUS LAYER. WE EXPECT LIFR CONDITIONS THROUGH MUCH
OF THE NIGHT AT KLBB...LIFTING SLIGHTLY NEAR DAYBREAK...THEN
BREAKING SWIFTLY BY MID-MORNING AS DRIER SOUTHWEST COMPONENT
PREVAILS. AT KCDS...THE CLOUD LAYER JUST WEST IN THE MID TO UPPER
IFR CIG HEIGHT RANGE IS MORE LIKELY TO FILL BACK EAST TO KCDS IN
THE NEXT FEW HOURS THAN SURFACE SATURATION BASED ON PERSISTENT
TRENDS IN THE RAP THIS EVENING. CIG AT KCDS SHOULD SLOWLY LIFT
EARLY MONDAY BEFORE BREAKING UP CLOSE TO MIDDAY. NEXT ON THE
HORIZON WILL BE THE SHARP CANADIAN COLD FRONT SURGING SOUTHWARD
TIMED PER LATEST WRF/NAM TO KCDS NEAR 04Z AND KLBB NEAR 06Z. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 1008 PM CST SUN NOV 10 2013/
UPDATE...
AREAS OF DENSE FOG ARE EXPECTED TO FORM RAPIDLY LATE THIS EVENING
INTO THE EARLY MORNING HOURS. MOST FAVORED AREA INITIALLY ACROSS
THE SOUTH-CENTRAL AND SOUTHEAST PANHANDLE INTO THE NORTHERN SOUTH
PLAINS SHOULD EXPAND SOUTH-SOUTHWESTWARD BY OR SHORTLY AFTER
MIDNIGHT THROUGH MUCH OF THE SOUTH PLAINS COUNTY. DENSE FOG
ADVISORY ISSUED VALID UNTIL 9 AM MONDAY. RMCQUEEN
AVIATION...
EARLIER TAF PACKAGE CONTINUED TO INDICATE DEVELOPMENT OF AN LIFR
STRATUS LAYER AT KLBB CLOSE TO OR SHORTLY AFTER MIDNIGHT AND
LASTING UNTIL NEAR OR JUST AFTER DAYBREAK MONDAY. CONDITIONS AT
KCDS WILL REMAIN MOSTLY NEAR IFR/MVFR BREAK-OFF UNTIL LIFTING LATE
MONDAY MORNING. RMCQUEEN
PREV DISCUSSION... /ISSUED 257 PM CST SUN NOV 10 2013/
SHORT TERM...
LOW CLOUDS WERE FINALLY RETREATING NORTHWARD...THOUGH THE NORTHEAST
ZONES WILL NOT HAVE MUCH TIME TO RECEIVE INSOLATION BEFORE THE SUN
SETS. IN ADDITION...SCATTERED TO BROKEN LOW CLOUDS WERE ALREADY
FILLING IN ACROSS PORTIONS OF THE ROLLING PLAINS AND MAY CONTINUE TO
FILL IN ACROSS THE EAST INTO THIS EVENING. ELSEWHERE WE WILL SEE A
PERIOD OF CLEAR SKIES. HOWEVER...LIGHT SOUTHERLY BREEZES OVERNIGHT
WILL MAINTAIN AND EVEN INCREASE THE SHALLOW MOISTURE ALREADY IN
PLACE...AND COUPLED WITH RADIATIONAL COOLING...WE WILL SEE ANOTHER
BOUT OF LOW CLOUDS AND FOG DEVELOP ACROSS THE AREA. TOUGH TO SAY
EXACTLY HOW THICK THE FOG WILL BECOME...BUT WE COULD DEFINITELY SEE
AREAS OF DENSE FOG AROUND BY EARLY MONDAY MORNING. WITH THIS IN MIND
WE HAVE ADDED FOG TO THE WEATHER GRIDS AND ALSO THE HWO. THINK FOG
WILL DEVELOP FIRST WHERE SKIES CLEAR ACROSS THE NORTHERN ZONES
/LIKELY THE NORTH-CENTRAL ZONES/...WHERE COOLER TEMPERATURES /AND
LOWER T-TD SPREADS/WORK WITH A MAXIMIZED UPSLOPE WIND COMPONENT. FOG
COULD DEVELOP ACROSS THIS FAVORED AREA AS EARLY AS 3Z OR SO...WITH
THE REMAINDER OF THE CWA AT RISK OF FOG DEVELOPMENT AFTER
MIDNIGHT...EVEN AS SURFACE WINDS VEER TO A SOUTHWESTERLY DIRECTION.
THE MOIST CONDITIONS WILL LIMIT COOL...WITH LOWS TONIGHT MOSTLY IN
THE MID AND UPPER 40S TO LOW 50S...EXCEPT ACROSS THE FAR
NORTHWESTERN ZONES WHERE SOMEWHAT LOWER DEWPOINTS MAY ALLOW LOWS TO
DIP INTO THE 30S.
THE FOG AND STRATUS SHOULD BEGIN TO LIFT/BREAK BY MID TO LATE
MORNING ON MONDAY...WITH MUCH OF THE FA EXPECTED TO SEE A
SUBSTANTIAL AMOUNT OF SUN IN THE AFTERNOON. OBVIOUSLY THE EXACT
DURATION/COVERAGE OF THE CLOUD COVER WILL DICTATE HOW WARM WE
GET...BUT HAVE MAINTAINED HIGHS IN THE LOWER TO MIDDLE 70S AREA
WIDE. BIG CHANGES WILL FOLLOW THOUGH AS A STRONG COLD FRONT WILL
MOVE IN TOMORROW NIGHT AS THE QUASI-ZONAL FLOW ALOFT VEERS IN
ADVANCE OF A RIDGE AMPLIFYING ACROSS THE WESTERN PART OF THE
CONTINENT.
LONG TERM...
COLD AIR THAT WILL BE MOVING THROUGH THE FCST AREA MONDAY NIGHT
HAS BEEN LET LOOSE FROM THE PRAIRIE PROVINCES INTO THE NRN
PLAINS...ALMOST TO SOUTH DAKOTA AS OF 20Z. PROBABLY NOT MUCH TO
SLOW IT SO PREFER THE FASTEST OF THE MODEL SOLUTIONS. GIVEN
STRENGTH OF THIS AIR MASS WILL ALSO LEAN TOWARD COLDER END OF MOS
GUIDANCE FOR TEMPS FROM MONDAY NIGHT THROUGH TUESDAY NIGHT. UPPER
PATTERN CONTINUES TO SUGGEST MODEL QPF AND MOS POPS ARE OVERDONE.
BOTH PLAN VIEWS AND TIME-HEIGHTS SUGGEST BEST BET IS SOME DRIZZLE
BEHIND THE FRONT BEFORE DRIER AIR BEGINS TO WORK IN TUESDAY AFTN.
SO WILL LOWER POPS SOME AND CONVERT MENTION OF SHOWERS/SPRINKLES
TO DRIZZLE WITH A MENTION OF FRZG DRIZZLE ACROSS NRN HALF OF THE
FCST AREA WHERE FREEZING TEMPS TUESDAY MORNING ARE LIKELY.
HOWEVER...ATTM NO IMPACTS EXPECTED ATTM FROM THE POSSIBLE LIGHT
FREEZING PRECIP.
MODELS CONTINUE TO EVOLVE MID TO LATE WEEK WITH AN OVERALL
PROGRESSIVE PATTERN IN WHAT BECOMES A MORE ZONAL BROADSCALE
PATTERN WITH EACH RUN. THAT WOULD HAVE THE EFFECT OF INCREASING
TEMPS MORE THAN PREVIOUSLY THOUGHT WITH MEXMOS EXHIBITING THAT
TREND ON THE 00Z AND 12Z RUNS. FOR NOW WILL TREND FCST THAT
DIRECTION BUT LEAN TOWARD TEMPS OF ENSEMBLE MEAN. PRECIP CHANCES
REMAIN LOW DESPITE A SERIES OF LOW-AMPLITUDE SHORT WAVE TROUGHS.
IN PART...THE PROGRESSIVE NATURE OF THE FLOW WILL KEEP MEANINGFUL
MOISTURE RETURN FROM OCCURRING WHILE THE LOW AMPLITUDE NATURE OF
THE TROUGHS SUGGEST FORCING MAY BE LIMITED. IF PRECIP DOES FALL
MODELS CONTINUE TO POINT TO FRIDAY AND FRIDAY NIGHT. FOR NOW WILL
KEEP THAT PERIOD WITH THE HIGHEST POPS BUT KEEP THEM BELOW 15 PCT
AND THUS KEEP PRECIP MENTION OUT OF THE FCST.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 37 73 25 37 23 / 0 0 10 10 0
TULIA 43 70 27 38 22 / 0 0 10 10 0
PLAINVIEW 44 71 28 38 22 / 0 0 10 10 0
LEVELLAND 45 72 31 37 26 / 0 0 10 10 0
LUBBOCK 47 71 31 37 24 / 0 0 10 10 0
DENVER CITY 46 70 34 41 27 / 0 0 10 10 0
BROWNFIELD 46 71 33 37 26 / 0 0 10 10 0
CHILDRESS 48 75 32 41 21 / 0 0 10 10 0
SPUR 49 73 32 39 22 / 0 0 10 10 0
ASPERMONT 52 75 36 40 23 / 0 0 10 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 9 AM CST MONDAY FOR THE FOLLOWING
ZONES: TXZ021>025-027>031-033>036-039>042.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
933 PM CST TUE NOV 12 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 924 PM CST TUE NOV 12 2013
HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING ON THE
BAY AND NORTHERN LAKE. ALTHOUGH WAA WILL RESULT IN MORE STABLE
CONDITIONS AND SHALLOW MIXING ON WEDNESDAY...BUFKIT SHOWS 950 MB
WINDS INCREASING TO 35-45 KTS...SO SOME GALE FORCE GUSTS LOOK LIKE
A GOOD BET. THE WINDS AND GUSTS SHOULD BE STRONGEST ON THE BAY AND
NORTHERN LAKE...WHERE THE FETCH IS LONGER FOR A SW WIND. COASTAL
CONVERGENCE SHOULD ALSO PLAY A FACTOR ALONG THE WESTERN SHORE OF
DOOR COUNTY. THE MIDNIGHT CREW CAN DECIDE IF THE REST OF THE LAKE
MICHIGAN ZONES (FROM SUE-SBM) NEED TO BE UPGRADED AT 4 AM.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1046MB
HIGH PRESSURE SYSTEM SLIDING SOUTHEAST ACROSS THE CENTRAL PLAINS
EARLY THIS AFTERNOON. LOW CLOUDS AND FLURRIES HAVE RETREATED
NORTHEAST OVER THE CENTRAL UPPER PENINSULA...AND THE ONLY CLOUD
COVER LEFT IS AN AREA OF THIN MID-LEVEL AND HIGH CLOUDS. LOOKING
UPSTREAM...PLENTY OF MOSTLY CLEAR CONDITIONS OVER THE NORTHERN
PLAINS...AND 12Z RAOBS SHOWS A VERY DRY AIRMASS IN PLACE THROUGH
THE COLUMN. SO AS THE SURFACE HIGH MOVES AWAY FROM THE REGION AND
THE PRESSURE GRADIENT TIGHTENS...TEMPS AND WIND GUSTS ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL SHIFT SOUTH FROM THE CENTRAL TO
SOUTHERN PLAINS. WEST WINDS WILL BACK AROUND TO THE SOUTHWEST AS
THIS OCCURS...AND REMAIN BREEZY THROUGH THE NIGHT. DESPITE MID AND
HIGH CLOUDS STAYING RATHER THIN AND SCATTERED IN NATURE...TEMPS
SHOULD NOT FALL MUCH DUE TO THIS SOUTHWEST BREEZE. UPSTREAM TEMPS
OVER NORTH DAKOTA FELL INTO THE LOWER TEENS TO LOWER 20S...SO WILL
KEEP TEMPS IN THAT RANGE.
WEDNESDAY...SHORTWAVE ENERGY WILL PUSH LOW PRESSURE ACROSS NORTHERN
ONTARIO WHILE THE ARCTIC HIGH WILL STILL BE LINGERING ACROSS THE
SOUTHERN MISSISSIPPI VALLEY. BETWEEN THESE TWO SYSTEMS...THE LOW
LEVEL PRESSURE GRADIENT WILL BE TIGHTENING AND WARM ADVECTING FROM
THE WEST. A STRONG INVERSION WILL DEVELOP...WHICH WILL PREVENT THE
WARMER AIR ALOFT FROM REACHING THE SURFACE. AS A RESULT...TEMPS
WILL NOT REACH THEIR POTENTIAL FROM MIXING...AND REMAIN IN THE UPPER
30S TO LOWER 40S DESPITE AMPLE SUNSHINE. SHOULD SEE SOME WIND GUSTS
APPROACHING 30 MPH THOUGH...LOCALLY STRONGER ON THE BAY SIDE OF THE
DOOR PENINSULA WHERE COASTAL CONVERGENCE WILL OCCUR. WINDS COULD
REACH UP TO 35-40 MPH THERE...WHICH BRINGS THE POSSIBILITY OF GALES
INTO THE PICTURE. HAVE HAD A FEW POTENTIAL GALES WITH WARM
ADVECTION ALREADY THIS FALL AND THEY SEEMED TO UNDER PERFORM WHAT
MODEL GUIDANCE INDICATED. WOULDNT BE SURPRISED IF THAT OCCURRED
AGAIN...BUT THE NAM/GFS/SREF INDICATE MINOR MIXING UP TO 950MB WHICH
WOULD BE ENOUGH TO GENERATE GALE FORCE GUSTS LATE WEDNESDAY
AFTERNOON. AFTER COORDINATION...HAVE DECIDED TO GO WITH A HIGH END
SMALL CRAFT ADVISORY...AND MENTION THE POSSIBILITY OF GALES OVER THE
MIDDLE BAY AND NEARSHORE WATERS ADJACENT TO THE DOOR PENINSULA.
LATER SHIFTS CAN TAKE ANOTHER LOOK AND UPGRADE IF NECESSARY.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
MILDER WEATHER IS EXPECTED THROUGH THE END OF THE WEEK AS UPPER
FLOW FIRST BECOMES ZONAL AND THEN SOUTHWEST. A WEAK SHORTWAVE
TROUGH AND ASSOCIATED WEAK SURFACE FRONT WILL MOVE THROUGH
THURSDAY AND THURSDAY NIGHT. DRY AIR WILL PROBABLY LIMIT
PRECIPITATION TO JUST SCATTERED LIGHT RAIN OR SNOW.
THE ECMWF HAS ABANDONED THE IDEA OF A BIG SNOWSTORM EARLY NEXT
WEEK THAT IT/S 12Z RUN YESTERDAY SUGGESTED. IT IS NOW MORE LIKE THE GFS
IN BRING A WEAKER SURFACE LOW FROM SOUTHERN COLORADO TO THE WESTERN
GREAT LAKES WITH RAIN FOR AT LEAST PART OF THE WEEKEND. THERE IS
STILL A DECENT AMOUNT OF DISAGREEMENT AS FAR AS TIMING AND AMOUNTS
THOUGH PRECIPITATION TYPE LOOKS TO BE MAINLY RAIN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 524 PM CST TUE NOV 12 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD...WITH ONLY
MID/HIGH CLOUDS AFFECTING THE REGION TONIGHT AND EARLY WEDNESDAY.
THE MAIN AVIATION CONCERN IS LLWS...WHICH WILL DEVELOP LATE TONIGHT
AND CONTINUE THROUGH WEDNESDAY. WEST-SOUTHWEST WINDS OF 45-50 KTS
WILL DEVELOP WITHIN 1-2K FEET AGL. DURING THE LATE MORNING AND
AFTERNOON...SFC WINDS WILL GUST TO 20-30 KTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
529 PM CST TUE NOV 12 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1046MB
HIGH PRESSURE SYSTEM SLIDING SOUTHEAST ACROSS THE CENTRAL PLAINS
EARLY THIS AFTERNOON. LOW CLOUDS AND FLURRIES HAVE RETREATED
NORTHEAST OVER THE CENTRAL UPPER PENINSULA...AND THE ONLY CLOUD
COVER LEFT IS AN AREA OF THIN MID-LEVEL AND HIGH CLOUDS. LOOKING
UPSTREAM...PLENTY OF MOSTLY CLEAR CONDITIONS OVER THE NORTHERN
PLAINS...AND 12Z RAOBS SHOWS A VERY DRY AIRMASS IN PLACE THROUGH
THE COLUMN. SO AS THE SURFACE HIGH MOVES AWAY FROM THE REGION AND
THE PRESSURE GRADIENT TIGHTENS...TEMPS AND WIND GUSTS ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL SHIFT SOUTH FROM THE CENTRAL TO
SOUTHERN PLAINS. WEST WINDS WILL BACK AROUND TO THE SOUTHWEST AS
THIS OCCURS...AND REMAIN BREEZY THROUGH THE NIGHT. DESPITE MID AND
HIGH CLOUDS STAYING RATHER THIN AND SCATTERED IN NATURE...TEMPS
SHOULD NOT FALL MUCH DUE TO THIS SOUTHWEST BREEZE. UPSTREAM TEMPS
OVER NORTH DAKOTA FELL INTO THE LOWER TEENS TO LOWER 20S...SO WILL
KEEP TEMPS IN THAT RANGE.
WEDNESDAY...SHORTWAVE ENERGY WILL PUSH LOW PRESSURE ACROSS NORTHERN
ONTARIO WHILE THE ARCTIC HIGH WILL STILL BE LINGERING ACROSS THE
SOUTHERN MISSISSIPPI VALLEY. BETWEEN THESE TWO SYSTEMS...THE LOW
LEVEL PRESSURE GRADIENT WILL BE TIGHTENING AND WARM ADVECTING FROM
THE WEST. A STRONG INVERSION WILL DEVELOP...WHICH WILL PREVENT THE
WARMER AIR ALOFT FROM REACHING THE SURFACE. AS A RESULT...TEMPS
WILL NOT REACH THEIR POTENTIAL FROM MIXING...AND REMAIN IN THE UPPER
30S TO LOWER 40S DESPITE AMPLE SUNSHINE. SHOULD SEE SOME WIND GUSTS
APPROACHING 30 MPH THOUGH...LOCALLY STRONGER ON THE BAY SIDE OF THE
DOOR PENINSULA WHERE COASTAL CONVERGENCE WILL OCCUR. WINDS COULD
REACH UP TO 35-40 MPH THERE...WHICH BRINGS THE POSSIBILITY OF GALES
INTO THE PICTURE. HAVE HAD A FEW POTENTIAL GALES WITH WARM
ADVECTION ALREADY THIS FALL AND THEY SEEMED TO UNDER PERFORM WHAT
MODEL GUIDANCE INDICATED. WOULDNT BE SURPRISED IF THAT OCCURRED
AGAIN...BUT THE NAM/GFS/SREF INDICATE MINOR MIXING UP TO 950MB WHICH
WOULD BE ENOUGH TO GENERATE GALE FORCE GUSTS LATE WEDNESDAY
AFTERNOON. AFTER COORDINATION...HAVE DECIDED TO GO WITH A HIGH END
SMALL CRAFT ADVISORY...AND MENTION THE POSSIBILITY OF GALES OVER THE
MIDDLE BAY AND NEARSHORE WATERS ADJACENT TO THE DOOR PENINSULA.
LATER SHIFTS CAN TAKE ANOTHER LOOK AND UPGRADE IF NECESSARY.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
MILDER WEATHER IS EXPECTED THROUGH THE END OF THE WEEK AS UPPER
FLOW FIRST BECOMES ZONAL AND THEN SOUTHWEST. A WEAK SHORTWAVE
TROUGH AND ASSOCIATED WEAK SURFACE FRONT WILL MOVE THROUGH
THURSDAY AND THURSDAY NIGHT. DRY AIR WILL PROBABLY LIMIT
PRECIPITATION TO JUST SCATTERED LIGHT RAIN OR SNOW.
THE ECMWF HAS ABANDONED THE IDEA OF A BIG SNOWSTORM EARLY NEXT
WEEK THAT IT/S 12Z RUN YESTERDAY SUGGESTED. IT IS NOW MORE LIKE THE GFS
IN BRING A WEAKER SURFACE LOW FROM SOUTHERN COLORADO TO THE WESTERN
GREAT LAKES WITH RAIN FOR AT LEAST PART OF THE WEEKEND. THERE IS
STILL A DECENT AMOUNT OF DISAGREEMENT AS FAR AS TIMING AND AMOUNTS
THOUGH PRECIPITATION TYPE LOOKS TO BE MAINLY RAIN.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 524 PM CST TUE NOV 12 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD...WITH ONLY
MID/HIGH CLOUDS AFFECTING THE REGION TONIGHT AND EARLY WEDNESDAY.
THE MAIN AVIATION CONCERN IS LLWS...WHICH WILL DEVELOP LATE TONIGHT
AND CONTINUE THROUGH WEDNESDAY. WEST-SOUTHWEST WINDS OF 45-50 KTS
WILL DEVELOP WITHIN 1-2K FEET AGL. DURING THE LATE MORNING AND
AFTERNOON...SFC WINDS WILL GUST TO 20-30 KTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 248 PM CST MON NOV 11 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATE THAT THE
ARCTIC COLD FRONT HAS BLASTED INTO CENTRAL ILLINOIS AND INDIANA
WHILE A POTENT 1043MB SURFACE HIGH IS NOSING SE ACROSS THE NORTHERN
PLAINS. TRAILING EDGE OF A MID-LEVEL CLOUD DECK IS DROPPING SOUTH
ACROSS CENTRAL AND EAST-CENTRAL WISCONSIN AND LOCATIONS IN THIS AREA
ARE SEEING SOME SUNSHINE ARRIVE. MEANWHILE FARTHER NORTH...LAKE
EFFECT STREAMERS ARE GROWING A LITTLE MORE SOLID THANKS TO MID-LEVEL
MOISTURE MOVING SW ACROSS LAKE SUPERIOR. WIND TRAJECTORIES HAVE
BECOME FAVORABLE FOR ACCUMULATING LAKE EFFECT SNOW SHOWERS...BUT THE
DRY AIR HAS LIMITED THE INTENSITY TO ONLY LIGHT SNOW SHOWERS AND
FLURRIES. AS THE ARCTIC HIGH MOVES TOWARDS THE REGION...SNOW
SHOWERS AND TEMPS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL BUILD ACROSS THE NORTHERN PLAINS
TOWARDS THE WESTERN GREAT LAKES. 850MB TEMPS WILL DROP IN THE
MID TEENS BELOW ZERO...BUT WILL STILL HAVE A DECENT PRESSURE
GRADIENT TO KEEP NNW WINDS PERSISTENT THOUGH LESS GUSTY. WIND
TRAJECTORIES AND LOWERING INVERSION HEIGHTS ARE FAVORABLE FOR LAKE
EFFECT STRATO-CU TO BUILD SOUTH INTO CENTRAL WISCONSIN THIS
EVENING...SIMILAR TO THE STRATUS BEHAVIOR OVER MINNESOTA THIS
MORNING. MOISTURE MOVING SOUTH OUT OF ONTARIO ALSO SUPPORTS THIS
IDEA. SO HAVE INCREASED CLOUD COVER AND PRECIP CHANCES ACROSS
NORTHERN WISCONSIN FOR THE EVENING. STILL NOT EXPECTING MUCH
ACCUMULATION THOUGH. THE MID-LEVEL MOISTURE WILL SHIFT TO THE EAST
OVERNIGHT AS LOW LEVEL WINDS BACK AROUND SLIGHTLY. SHOULD THEREFORE
SEE THE LAKE CLOUDS/STRATUS RETREAT TOWARDS THE SNOW BELTS OF N-C
WISCONSIN LATE. BUT DESPITE CLEARING TAKING PLACE OVERNIGHT...THE
BRISK NNW WINDS WILL KEEP TEMPERATURES UP AND WILL GO WITH LOWS
RANGING FROM THE LOWER TEENS NORTH TO THE LOWER 20S SOUTH.
TUESDAY...STRONG ARCTIC HIGH PRESSURE WILL SHIFT SOUTHEAST TOWARDS
THE MID-MISSISSIPPI VALLEY. AS THIS OCCURS...LOW LEVEL WINDS WILL
BACK TO THE NORTHWEST AND THEN THE WEST-NORTHWEST...WHICH WILL CAUSE
MORNING LAKE EFFECT CLOUDS TO RETREAT NORTH TO THE UPPER PENINSULA.
SHOULD OTHERWISE SEE A MOSTLY SUNNY TO PARTLY CLOUDY DAY ACROSS THE
REGION. RATHER THIN MID AND HIGH CLOUDS WILL FILTER SOUTH AROUND
MIDDAY WHICH WILL LIKELY PARTIALLY FILTER THE SUN. HIGHS WILL
REMAIN COLD...WITH HIGHS RANGING FROM THE MIDDLE 20S NORTH TO LOWER
30S SOUTHEAST.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 248 PM CST MON NOV 11 2013
THE BRIEF COLD SNAP WILL END WEDNESDAY AS A FLAT UPPER
RIDGE ARRIVES AND LOW LEVEL FLOW BECOMES SOUTHERLY. HE UPPER FLOW
BECOMES SOUTHWEST THURSDAY THROUGH FRIDAY WITH A WEAK SURFACE
FRONT FROM THE SOUTHERN PLAINS TO THE GREAT LAKES PROVIDING SOME
SUPPORT FOR LIGHT PRECIPITATION THURSDAY AND FRIDAY. IT SHOULD BE
MOSTLY RAIN THURSDAY AND THURSDAY NIGHT AND THEN CHANGE TO LIGHT
SNOW FRIDAY AS THE FRONT EDGES EAST. THEN DRY AND MILD SATURDAY
THROUGH AT LEAST SUNDAY MORNING AS UPPER HEIGHTS RISE AND
SOUTHERLY FLOW INCREASES AT THE SURFACE. THE GFS AND ECMWF THEN
BEGIN TO DIVERGE GREATLY FOR SUNDAY NIGHT THROUGH NEXT TUESDAY.
THE GFS BRINGS A SHORTWAVE TROUGH THROUGH THE GREAT LAKES WITH TWO
SURFACE LOWS IN THE PLAINS PHASING OVER NORTHERN ILLINOIS AND
MOVING INTO MICHIGAN WITH RAIN SUNDAY AFTERNOON AND EVENING. THE
ECMWF IS MUCH SLOWER AND DEEPER WITH THE APPROACHING TROUGH
EVENTUALLY PRODUCING A CLOSED UPPER LOW OVER IOWA WHICH SLOWS AND
DEEPENS MONDAY AND TUESDAY. IT WOULD BRING RAIN AND MILD WEATHER
SUNDAY AND MONDAY AND THEN A SNOWSTORM MONDAY NIGHT THROUGH
TUESDAY NIGHT. THAT/S TOO FAR OUT TO THINK ABOUT RIGHT NOW AND IT
IS RATHER EARLY IN THE SEASON...BUT THESE TYPE OF SYSTEMS ARE THE ONES
THAT PRODUCE SOME OF THE BIGGER SNOWS IN NORTHEAST WISCONSIN.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1131 AM CST MON NOV 11 2013
BAND OF PRECIPITATION ALONG AN ARCTIC COLD FRONT HAS SHIFTED INTO
SOUTHERN WISCONSIN. ARCTIC AIRMASS IS FIRMLY ENTRENCHED ACROSS THE
REGION. THOUGH IT IS VERY DRY...NNW WINDS WILL GENERATE LAKE EFFECT
MVFR CLOUDS AND VSBYS IN OCCASIONAL SNOW SHOWERS OVER NORTH-CENTRAL
WISCONSIN...INCLUDING RHINELANDER THROUGH TONIGHT. LOCALLY IFR
VSBYS POSSIBLE WITHIN THE BEEFIER SNOW SHOWERS. SOME UNCERTAINTY
HOW FAR SOUTH THE LAKE EFFECT CLOUDS WILL REACH. SOME INDICATIONS
UPSTREAM THAT THEY COULD REACH INTO CENTRAL WISCONSIN TONIGHT...SO
ADDED A TEMPO GROUP AT AUW/CWA TO ACCOUNT FOR THIS. IMPROVING
CONDITIONS LATE TONIGHT INTO TUESDAY. LOW LEVEL WINDS WILL BACK
AROUND TO THE WEST NORTHWEST...WHICH SHOULD CAUSE THE CLOUDS TO
RETREAT TO THE NORTH. GUSTY NORTHWEST WINDS WILL SUBSIDE LATER
TONIGHT AS WELL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1131 AM CST MON NOV 11 2013
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 428 AM CST MON NOV 11 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATE STRONG
COLD FRONT NOW EXTENDING ACROSS CWA FROM NEAR IMT TO RRL. BEHIND
THE FRONT TEMPERATURES DROPPING QUICKLY INTO LOWER TO MIDDLE 20S.
NORTHWEST WINDS ALSO QUITE GUSTY BEHIND FRONT. RADAR RETURNS HAVE
FILLED IN/EXPANDED MIDNIGHT ONWARD IN RESPONSE TO STRONG FGEN
FORCING OVER NORTHERN AND CENTRAL WI. LIGHT SNOW FALLING NORTH OF
FRONT...RAIN SOUTH. NO SNOWFALL AMOUNTS REPORTED AS OF YET...THOUGH WEBCAMS
FAR NORTH LOOK LIKE GOOD INCH HAS FALLEN SO FAR.
MAIN CHANGE IN THIS FORECAST WAS TO SLOW PROGRESSION
SLIGHTLY...INCLUDING RAIN TO SNOW CHANGEOVER. FORCING EXPECTED TO
DROP SOUTH AND EAST THROUGH AREA THROUGH MID MORNING. HAVE TRIED
TO DEPICT TEMP DROP THROUGH THIS MORNING...THEN NEAR STEADY TEMPS
THROUGH THE AFTERNOON. WITH SLOWER DROP IN TEMPS OVER FOX VALLEY
THIS MORNING...WILL UPDATE SPS SENT OUT EARLIER TO HIGHLIGHT AREAS
WEST AND NORTH FOR THE MORNING COMMUTE.
HIGH PRESSURE TO DROP SOUTH INTO THE PLAINS TONIGHT AND TUE MAKING
CONDITIONS LESS FAVORABLE FOR LES OVER THE NORTH. HAVE STAYED WITH
CHANCE/SCATTERED WORDING AND PREVIOUS SNOW AMOUNTS IN THE SNOW
BELT FOR TODAY GIVEN DRY AIR AND LOWERING INVERSION HEIGHTS.
COLD TEMPS TO CONTINUE THROUGH THE PERIOD WITH APPARENT TEMPS
TODAY RUNNING IN THE SINGLE DIGITS NORTH AND TEENS SOUTH. TONIGHT
WINDS WILL MAKE IT FEEL LIKE NEAR ZERO NORTH AND SINGLE DIGITS
SOUTH. LIGHTER WINDS LATER TUE WILL BRING SOME IMPROVEMENT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 428 AM CST MON NOV 11 2013
MDLS CONT TO INDICATE THE DEVELOPMENT OF UPR RDGS OVER THE ERN
PACIFIC AND WRN ATLANTIC WITH A BROAD UPR TROF OVER THE CNTRL
CONUS. MEAN FLOW OVER THE GREAT LAKES WL SWITCH FROM NW TO SW AS
THIS UPR TROF DEVELOPS WHICH WL BRING MILDER...BUT MORE UNSETTLED
WEATHER TO NE WI TOWARD NEXT WEEKEND. MAIN FCST ISSUE WL BE TRYING
TO DETERMINE BEST PERIOD TO MENTION PCPN CHCS AS THE MDLS DIFFER
ON WHICH BRANCH OF THE JET WL BECOME MORE DOMINANT.
THE SFC RDG AXIS TO EXTEND FROM THE SRN PLAINS NEWD TO SRN
SECTIONS OF THE GREAT LAKES TUE NGT. MEANWHILE...A WEAKENING UPR
RDG WL BE PUSHING ACROSS THE UPR MS VALLEY TOWARD WI. THIS
TRANSLATES TO A QUIET WEATHER PATTERN FOR NE WI UNDER MOSTLY CLR
SKIES AND W-SW WINDS UNDER 10 MPH. WEAK WAA TO PERSIST THRU THE
NGT AND THIS WL HELP TO COUNTER THE UNSEASONABLY COOL AIR MASS
OVERHEAD. MIN TEMPS ARE EXPECTED TO BE CLOSE TO VALUES SEEN MON
NGT (GENERALLY TEENS INLAND...AROUND 20 NEAR LAKE MI). INCREASING
SW WINDS BETWEEN THE SFC HI OVER THE TN VALLEY AND A SFC LOW
MOVING INTO WRN ONTARIO ON WED WL BRING A MILDER AIR MASS INTO WI.
8H TEMPS CONT TO RISE TO ALMOST +6C BY 00Z THU AND WITH SKIES
STILL MOSTLY SUNNY...TEMPS WL BE ABLE TO RISE CLOSE TO SEASONAL
NORMS (MID 30S TO AROUND 40 DEGS).
SOME INCREASE IN CLOUDS CAN BE EXPECTED WED NGT AS A WEAK CDFNT
PUSHES TOWARD THE WRN GREAT LAKES. NO PCPN IS FCST INITIALLY DUE
TO THE VERY DRY AIR MASS OVER WI AT THE ONSET. PERSISTENT SW WINDS
COMBINED WITH THE INCREASE IN CLOUDS...WL PREVENT TEMPS FROM
FALLING AS FAR AS THE PAST TWO NGTS. LOOK FOR READINGS TO ONLY
SETTLE INTO THE MID TO UPR 20S. THIS APPROACHING CDFNT IS PROGGED
TO SLOW ITS FORWARD SPEED...WAITING FOR A TRAILING SHORTWAVE TROF
(OVER THE UPR MS VALLEY) TO CATCH UP ON THU. AS THIS OCCURS...THE
ATMOSPHERE WL CONT TO GRADUALLY SATURATE...AS WELL AS SEEING
INCREASED LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET.
CANNOT RULE OUT SOME LIGHT PCPN DEVELOPING SOMEWHERE OVER THE FCST
AREA...ESPECIALLY DURING THE AFTERNOON. TEMPS SHOULD BE ABLE TO
WARM ENUF SUCH THAT MOST OF THE PCPN WOULD FALL AS RAIN...ALTHO A
MIX IS POSSIBLE ESPECIALLY IF THE PCPN CAN REACH NRN WI.
THE WEAK CDFNT/SHORTWAVE TROF COMBINATION TO THEN PUSH ACROSS MOST
OF WI THU NGT AND BRING AT LEAST A CHC OF PCPN TO THE ENTIRE FCST
AREA. FCST ISSUE WL BE ON PCPN TYPE AS TEMPS DROP INTO THE UPR 20S
TO LWR 30S AND THE 8H 0C ISOTHERM HOVERS OVER NE WI. SINCE THE BULK
OF PCPN APPEARS TO MOVE THRU NE WI THU EVENING...ANTICIPATE PCPN TO
FALL AS LIGHT SNOW NORTH AND A RAIN/SNOW MIX OVER CNTRL AND E-CNTRL
WI. THIS SYSTEM IS FCST TO CLEAR THE REGION BY FRI...ALTHO THE LACK
OF DRY AIR AND SUBSIDENCE BEHIND THE SYSTEM MAY KEEP MORE CLOUDS
AROUND THRU THE DAY. DUE TO THE WEAK NATURE OF THE CDFNT AND WINDS
ALOFT ONLY VEERING TO THE WEST...MAX TEMPS ON FRI ARE STILL EXPECTED
TO BE NEAR NORMAL FOR MID-NOVEMBER.
LARGE MDL DIFFERENCES REMAIN NEXT WEEKEND AS THE GFS/GEM FAVOR MORE
OF A NRN STREAM SYSTEM IMPACTING NE WI SAT NGT INTO SUNDAY. ON THE
OTHER HAND...THE ECMWF CONTS TO FOCUS ON A STRONGER SRN STREAM
SYSTEM LIFTING N-NE FROM THE SRN PLAINS TO THE GREAT LAKES FROM SAT
NGT INTO SUNDAY. WHILE THE THERMAL PROFILES WOULD INDICATE RAIN AS
THE PRIMARY PCPN TYPE NO MATTER WHICH SOLUTION VERIFIES...THE ECMWF
SOLUTION WOULD TAP MORE GULF MOISTURE AND THEREBY BRINGS HEAVIER
RAINS TO NE WI. UNTIL THESE DIFFERENCES CAN BE BETTER RESOLVED...
WL KEEP POPS IN THE CHC CATEGORY FOR BOTH SAT NGT AND SUNDAY WITH
TEMPS ACTUALLY ABOVE NORMAL THRU THE WEEKEND.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1131 AM CST MON NOV 11 2013
BAND OF PRECIPITATION ALONG AN ARCTIC COLD FRONT HAS SHIFTED INTO
SOUTHERN WISCONSIN. ARCTIC AIRMASS IS FIRMLY ENTRENCHED ACROSS THE
REGION. THOUGH IT IS VERY DRY...NNW WINDS WILL GENERATE LAKE EFFECT
MVFR CLOUDS AND VSBYS IN OCCASIONAL SNOW SHOWERS OVER NORTH-CENTRAL
WISCONSIN...INCLUDING RHINELANDER THROUGH TONIGHT. LOCALLY IFR
VSBYS POSSIBLE WITHIN THE BEEFIER SNOW SHOWERS. SOME UNCERTAINTY
HOW FAR SOUTH THE LAKE EFFECT CLOUDS WILL REACH. SOME INDICATIONS
UPSTREAM THAT THEY COULD REACH INTO CENTRAL WISCONSIN TONIGHT...SO
ADDED A TEMPO GROUP AT AUW/CWA TO ACCOUNT FOR THIS. IMPROVING
CONDITIONS LATE TONIGHT INTO TUESDAY. LOW LEVEL WINDS WILL BACK
AROUND TO THE WEST NORTHWEST...WHICH SHOULD CAUSE THE CLOUDS TO
RETREAT TO THE NORTH. GUSTY NORTHWEST WINDS WILL SUBSIDE LATER
TONIGHT AS WELL.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
601 AM CST MON NOV 11 2013
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 428 AM CST MON NOV 11 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATE STRONG
COLD FRONT NOW EXTENDING ACROSS CWA FROM NEAR IMT TO RRL. BEHIND
THE FRONT TEMPERATURES DROPPING QUICKLY INTO LOWER TO MIDDLE 20S.
NORTHWEST WINDS ALSO QUITE GUSTY BEHIND FRONT. RADAR RETURNS HAVE
FILLED IN/EXPANDED MIDNIGHT ONWARD IN RESPONSE TO STRONG FGEN
FORCING OVER NORTHERN AND CENTRAL WI. LIGHT SNOW FALLING NORTH OF
FRONT...RAIN SOUTH. NO SNOWFALL AMOUNTS REPORTED AS OF YET...THOUGH WEBCAMS
FAR NORTH LOOK LIKE GOOD INCH HAS FALLEN SO FAR.
MAIN CHANGE IN THIS FORECAST WAS TO SLOW PROGRESSION
SLIGHTLY...INCLUDING RAIN TO SNOW CHANGEOVER. FORCING EXPECTED TO
DROP SOUTH AND EAST THROUGH AREA THROUGH MID MORNING. HAVE TRIED
TO DEPICT TEMP DROP THROUGH THIS MORNING...THEN NEAR STEADY TEMPS
THROUGH THE AFTERNOON. WITH SLOWER DROP IN TEMPS OVER FOX VALLEY
THIS MORNING...WILL UPDATE SPS SENT OUT EARLIER TO HIGHLIGHT AREAS
WEST AND NORTH FOR THE MORNING COMMUTE.
HIGH PRESSURE TO DROP SOUTH INTO THE PLAINS TONIGHT AND TUE MAKING
CONDITIONS LESS FAVORABLE FOR LES OVER THE NORTH. HAVE STAYED WITH
CHANCE/SCATTERED WORDING AND PREVIOUS SNOW AMOUNTS IN THE SNOW
BELT FOR TODAY GIVEN DRY AIR AND LOWERING INVERSION HEIGHTS.
COLD TEMPS TO CONTINUE THROUGH THE PERIOD WITH APPARENT TEMPS
TODAY RUNNING IN THE SINGLE DIGITS NORTH AND TEENS SOUTH. TONIGHT
WINDS WILL MAKE IT FEEL LIKE NEAR ZERO NORTH AND SINGLE DIGITS
SOUTH. LIGHTER WINDS LATER TUE WILL BRING SOME IMPROVEMENT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 428 AM CST MON NOV 11 2013
MDLS CONT TO INDICATE THE DEVELOPMENT OF UPR RDGS OVER THE ERN
PACIFIC AND WRN ATLANTIC WITH A BROAD UPR TROF OVER THE CNTRL
CONUS. MEAN FLOW OVER THE GREAT LAKES WL SWITCH FROM NW TO SW AS
THIS UPR TROF DEVELOPS WHICH WL BRING MILDER...BUT MORE UNSETTLED
WEATHER TO NE WI TOWARD NEXT WEEKEND. MAIN FCST ISSUE WL BE TRYING
TO DETERMINE BEST PERIOD TO MENTION PCPN CHCS AS THE MDLS DIFFER
ON WHICH BRANCH OF THE JET WL BECOME MORE DOMINANT.
THE SFC RDG AXIS TO EXTEND FROM THE SRN PLAINS NEWD TO SRN
SECTIONS OF THE GREAT LAKES TUE NGT. MEANWHILE...A WEAKENING UPR
RDG WL BE PUSHING ACROSS THE UPR MS VALLEY TOWARD WI. THIS
TRANSLATES TO A QUIET WEATHER PATTERN FOR NE WI UNDER MOSTLY CLR
SKIES AND W-SW WINDS UNDER 10 MPH. WEAK WAA TO PERSIST THRU THE
NGT AND THIS WL HELP TO COUNTER THE UNSEASONABLY COOL AIR MASS
OVERHEAD. MIN TEMPS ARE EXPECTED TO BE CLOSE TO VALUES SEEN MON
NGT (GENERALLY TEENS INLAND...AROUND 20 NEAR LAKE MI). INCREASING
SW WINDS BETWEEN THE SFC HI OVER THE TN VALLEY AND A SFC LOW
MOVING INTO WRN ONTARIO ON WED WL BRING A MILDER AIR MASS INTO WI.
8H TEMPS CONT TO RISE TO ALMOST +6C BY 00Z THU AND WITH SKIES
STILL MOSTLY SUNNY...TEMPS WL BE ABLE TO RISE CLOSE TO SEASONAL
NORMS (MID 30S TO AROUND 40 DEGS).
SOME INCREASE IN CLOUDS CAN BE EXPECTED WED NGT AS A WEAK CDFNT
PUSHES TOWARD THE WRN GREAT LAKES. NO PCPN IS FCST INITIALLY DUE
TO THE VERY DRY AIR MASS OVER WI AT THE ONSET. PERSISTENT SW WINDS
COMBINED WITH THE INCREASE IN CLOUDS...WL PREVENT TEMPS FROM
FALLING AS FAR AS THE PAST TWO NGTS. LOOK FOR READINGS TO ONLY
SETTLE INTO THE MID TO UPR 20S. THIS APPROACHING CDFNT IS PROGGED
TO SLOW ITS FORWARD SPEED...WAITING FOR A TRAILING SHORTWAVE TROF
(OVER THE UPR MS VALLEY) TO CATCH UP ON THU. AS THIS OCCURS...THE
ATMOSPHERE WL CONT TO GRADUALLY SATURATE...AS WELL AS SEEING
INCREASED LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET.
CANNOT RULE OUT SOME LIGHT PCPN DEVELOPING SOMEWHERE OVER THE FCST
AREA...ESPECIALLY DURING THE AFTERNOON. TEMPS SHOULD BE ABLE TO
WARM ENUF SUCH THAT MOST OF THE PCPN WOULD FALL AS RAIN...ALTHO A
MIX IS POSSIBLE ESPECIALLY IF THE PCPN CAN REACH NRN WI.
THE WEAK CDFNT/SHORTWAVE TROF COMBINATION TO THEN PUSH ACROSS MOST
OF WI THU NGT AND BRING AT LEAST A CHC OF PCPN TO THE ENTIRE FCST
AREA. FCST ISSUE WL BE ON PCPN TYPE AS TEMPS DROP INTO THE UPR 20S
TO LWR 30S AND THE 8H 0C ISOTHERM HOVERS OVER NE WI. SINCE THE BULK
OF PCPN APPEARS TO MOVE THRU NE WI THU EVENING...ANTICIPATE PCPN TO
FALL AS LIGHT SNOW NORTH AND A RAIN/SNOW MIX OVER CNTRL AND E-CNTRL
WI. THIS SYSTEM IS FCST TO CLEAR THE REGION BY FRI...ALTHO THE LACK
OF DRY AIR AND SUBSIDENCE BEHIND THE SYSTEM MAY KEEP MORE CLOUDS
AROUND THRU THE DAY. DUE TO THE WEAK NATURE OF THE CDFNT AND WINDS
ALOFT ONLY VEERING TO THE WEST...MAX TEMPS ON FRI ARE STILL EXPECTED
TO BE NEAR NORMAL FOR MID-NOVEMBER.
LARGE MDL DIFFERENCES REMAIN NEXT WEEKEND AS THE GFS/GEM FAVOR MORE
OF A NRN STREAM SYSTEM IMPACTING NE WI SAT NGT INTO SUNDAY. ON THE
OTHER HAND...THE ECMWF CONTS TO FOCUS ON A STRONGER SRN STREAM
SYSTEM LIFTING N-NE FROM THE SRN PLAINS TO THE GREAT LAKES FROM SAT
NGT INTO SUNDAY. WHILE THE THERMAL PROFILES WOULD INDICATE RAIN AS
THE PRIMARY PCPN TYPE NO MATTER WHICH SOLUTION VERIFIES...THE ECMWF
SOLUTION WOULD TAP MORE GULF MOISTURE AND THEREBY BRINGS HEAVIER
RAINS TO NE WI. UNTIL THESE DIFFERENCES CAN BE BETTER RESOLVED...
WL KEEP POPS IN THE CHC CATEGORY FOR BOTH SAT NGT AND SUNDAY WITH
TEMPS ACTUALLY ABOVE NORMAL THRU THE WEEKEND.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 543 AM CST MON NOV 11 2013
A STRONG ARCTIC COLD FRONT MOVING THROUGH THE FORECAST AREA
THIS MORNING WILL BRING GUSTY NW WINDS...FALLING TEMPS AND SOME
LIGHT RAIN OR SNOW THIS MORNING. MVFR CONDITIONS WILL OCCUR WITH THE
SNOW...LINGERING OVER THE REGION FOR A WHILE THIS MORNING. SCATTERED
LAKE-EFFECT SNOW SHOWERS AND ASSOCIATED MVFR CONDITIONS WILL
CONTINUE OVER NC WI THROUGH TONIGHT...WHILE THE REST OF THE REGION
SEES CLEARING SKIES IN THE AFTERNOON. COLD AND BREEZY CONDITIONS
EXPECTED THROUGH THE NIGHT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......TE
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 428 AM CST MON NOV 11 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY INDICATE STRONG
COLD FRONT NOW EXTENDING ACROSS CWA FROM NEAR IMT TO RRL. BEHIND
THE FRONT TEMPERATURES DROPPING QUICKLY INTO LOWER TO MIDDLE 20S.
NORTHWEST WINDS ALSO QUITE GUSTY BEHIND FRONT. RADAR RETURNS HAVE
FILLED IN/EXPANDED MIDNIGHT ONWARD IN RESPONSE TO STRONG FGEN
FORCING OVER NORTHERN AND CENTRAL WI. LIGHT SNOW FALLING NORTH OF
FRONT...RAIN SOUTH. NO SNOWFALL AMOUNTS REPORTED AS OF YET...THOUGH WEBCAMS
FAR NORTH LOOK LIKE GOOD INCH HAS FALLEN SO FAR.
MAIN CHANGE IN THIS FORECAST WAS TO SLOW PROGRESSION
SLIGHTLY...INCLUDING RAIN TO SNOW CHANGEOVER. FORCING EXPECTED TO
DROP SOUTH AND EAST THROUGH AREA THROUGH MID MORNING. HAVE TRIED
TO DEPICT TEMP DROP THROUGH THIS MORNING...THEN NEAR STEADY TEMPS
THROUGH THE AFTERNOON. WITH SLOWER DROP IN TEMPS OVER FOX VALLEY
THIS MORNING...WILL UPDATE SPS SENT OUT EARLIER TO HIGHLIGHT AREAS
WEST AND NORTH FOR THE MORNING COMMUTE.
HIGH PRESSURE TO DROP SOUTH INTO THE PLAINS TONIGHT AND TUE MAKING
CONDITIONS LESS FAVORABLE FOR LES OVER THE NORTH. HAVE STAYED WITH
CHANCE/SCATTERED WORDING AND PREVIOUS SNOW AMOUNTS IN THE SNOW
BELT FOR TODAY GIVEN DRY AIR AND LOWERING INVERSION HEIGHTS.
COLD TEMPS TO CONTINUE THROUGH THE PERIOD WITH APPARENT TEMPS
TODAY RUNNING IN THE SINGLE DIGITS NORTH AND TEENS SOUTH. TONIGHT
WINDS WILL MAKE IT FEEL LIKE NEAR ZERO NORTH AND SINGLE DIGITS
SOUTH. LIGHTER WINDS LATER TUE WILL BRING SOME IMPROVEMENT.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 428 AM CST MON NOV 11 2013
MDLS CONT TO INDICATE THE DEVELOPMENT OF UPR RDGS OVER THE ERN
PACIFIC AND WRN ATLANTIC WITH A BROAD UPR TROF OVER THE CNTRL
CONUS. MEAN FLOW OVER THE GREAT LAKES WL SWITCH FROM NW TO SW AS
THIS UPR TROF DEVELOPS WHICH WL BRING MILDER...BUT MORE UNSETTLED
WEATHER TO NE WI TOWARD NEXT WEEKEND. MAIN FCST ISSUE WL BE TRYING
TO DETERMINE BEST PERIOD TO MENTION PCPN CHCS AS THE MDLS DIFFER
ON WHICH BRANCH OF THE JET WL BECOME MORE DOMINANT.
THE SFC RDG AXIS TO EXTEND FROM THE SRN PLAINS NEWD TO SRN
SECTIONS OF THE GREAT LAKES TUE NGT. MEANWHILE...A WEAKENING UPR
RDG WL BE PUSHING ACROSS THE UPR MS VALLEY TOWARD WI. THIS
TRANSLATES TO A QUIET WEATHER PATTERN FOR NE WI UNDER MOSTLY CLR
SKIES AND W-SW WINDS UNDER 10 MPH. WEAK WAA TO PERSIST THRU THE
NGT AND THIS WL HELP TO COUNTER THE UNSEASONABLY COOL AIR MASS
OVERHEAD. MIN TEMPS ARE EXPECTED TO BE CLOSE TO VALUES SEEN MON
NGT (GENERALLY TEENS INLAND...AROUND 20 NEAR LAKE MI). INCREASING
SW WINDS BETWEEN THE SFC HI OVER THE TN VALLEY AND A SFC LOW
MOVING INTO WRN ONTARIO ON WED WL BRING A MILDER AIR MASS INTO WI.
8H TEMPS CONT TO RISE TO ALMOST +6C BY 00Z THU AND WITH SKIES
STILL MOSTLY SUNNY...TEMPS WL BE ABLE TO RISE CLOSE TO SEASONAL
NORMS (MID 30S TO AROUND 40 DEGS).
SOME INCREASE IN CLOUDS CAN BE EXPECTED WED NGT AS A WEAK CDFNT
PUSHES TOWARD THE WRN GREAT LAKES. NO PCPN IS FCST INITIALLY DUE
TO THE VERY DRY AIR MASS OVER WI AT THE ONSET. PERSISTENT SW WINDS
COMBINED WITH THE INCREASE IN CLOUDS...WL PREVENT TEMPS FROM
FALLING AS FAR AS THE PAST TWO NGTS. LOOK FOR READINGS TO ONLY
SETTLE INTO THE MID TO UPR 20S. THIS APPROACHING CDFNT IS PROGGED
TO SLOW ITS FORWARD SPEED...WAITING FOR A TRAILING SHORTWAVE TROF
(OVER THE UPR MS VALLEY) TO CATCH UP ON THU. AS THIS OCCURS...THE
ATMOSPHERE WL CONT TO GRADUALLY SATURATE...AS WELL AS SEEING
INCREASED LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET.
CANNOT RULE OUT SOME LIGHT PCPN DEVELOPING SOMEWHERE OVER THE FCST
AREA...ESPECIALLY DURING THE AFTERNOON. TEMPS SHOULD BE ABLE TO
WARM ENUF SUCH THAT MOST OF THE PCPN WOULD FALL AS RAIN...ALTHO A
MIX IS POSSIBLE ESPECIALLY IF THE PCPN CAN REACH NRN WI.
THE WEAK CDFNT/SHORTWAVE TROF COMBINATION TO THEN PUSH ACROSS MOST
OF WI THU NGT AND BRING AT LEAST A CHC OF PCPN TO THE ENTIRE FCST
AREA. FCST ISSUE WL BE ON PCPN TYPE AS TEMPS DROP INTO THE UPR 20S
TO LWR 30S AND THE 8H 0C ISOTHERM HOVERS OVER NE WI. SINCE THE BULK
OF PCPN APPEARS TO MOVE THRU NE WI THU EVENING...ANTICIPATE PCPN TO
FALL AS LIGHT SNOW NORTH AND A RAIN/SNOW MIX OVER CNTRL AND E-CNTRL
WI. THIS SYSTEM IS FCST TO CLEAR THE REGION BY FRI...ALTHO THE LACK
OF DRY AIR AND SUBSIDENCE BEHIND THE SYSTEM MAY KEEP MORE CLOUDS
AROUND THRU THE DAY. DUE TO THE WEAK NATURE OF THE CDFNT AND WINDS
ALOFT ONLY VEERING TO THE WEST...MAX TEMPS ON FRI ARE STILL EXPECTED
TO BE NEAR NORMAL FOR MID-NOVEMBER.
LARGE MDL DIFFERENCES REMAIN NEXT WEEKEND AS THE GFS/GEM FAVOR MORE
OF A NRN STREAM SYSTEM IMPACTING NE WI SAT NGT INTO SUNDAY. ON THE
OTHER HAND...THE ECMWF CONTS TO FOCUS ON A STRONGER SRN STREAM
SYSTEM LIFTING N-NE FROM THE SRN PLAINS TO THE GREAT LAKES FROM SAT
NGT INTO SUNDAY. WHILE THE THERMAL PROFILES WOULD INDICATE RAIN AS
THE PRIMARY PCPN TYPE NO MATTER WHICH SOLUTION VERIFIES...THE ECMWF
SOLUTION WOULD TAP MORE GULF MOISTURE AND THEREBY BRINGS HEAVIER
RAINS TO NE WI. UNTIL THESE DIFFERENCES CAN BE BETTER RESOLVED...
WL KEEP POPS IN THE CHC CATEGORY FOR BOTH SAT NGT AND SUNDAY WITH
TEMPS ACTUALLY ABOVE NORMAL THRU THE WEEKEND.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1119 PM CST SUN NOV 10 2013
A STRONG ARCTIC COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
OVERNIGHT INTO EARLY MONDAY...BRINGING GUSTY NW WINDS...FALLING
TEMPS AND SOME LIGHT SNOW. RAIN WILL BE POSSIBLE EARLY IN THE TAF
PERIOD AT ATW/GRB. THE SNOW WILL BE HEAVIEST WHEN THE FRONT MOVES
THROUGH...WITH VSBYS DROPPING TO AS LOW AS 1SM-2SM. MVFR/IFR
CONDITIONS WILL OCCUR WITH THE SNOW...AND SOME MVFR CIGS WILL
LINGER OVER THE REGION FOR A WHILE MONDAY MORNING. LAKE-EFFECT
SNOW SHOWERS AND ASSOCIATED MVFR CONDITIONS SHOULD CONTINUE OVER
NC WI THROUGH THE DAY...WHILE THE REST OF THE REGION SEES AN
IMPROVEMENT TO VFR CONDITIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TE
LONG TERM......KALLAS
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
306 AM CST MON NOV 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 306 AM CST MON NOV 11 2013
MAIN FORECAST CONCERNS ARE ON LIGHT SNOW TODAY AND TEMPERATURES
TONIGHT THROUGH WEDNESDAY.
LATEST SURFACE OBSERVATIONS PLACED A COLD FRONT EXTENDING FROM
EASTERN LAKE SUPERIOR SOUTHWEST THROUGH NORTH CENTRAL WISCONSIN
INTO SOUTHERN MINNESOTA THROUGH SOUTHERN SOUTH DAKOTA...PUSHING
SOUTH. AN IMPRESSIVE TEMPERATURE CHANGE BEHIND THE FRONT WITH
TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS NORTH CENTRAL
NORTH DAKOTA. RADAR SHOWED A BAND OF PRECIPITATION SETTING UP FROM
CENTRAL WISCONSIN THROUGH SOUTHERN MINNESOTA BACK INTO NORTHERN
SOUTH DAKOTA. LIGHT SNOW HAS BEEN REPORTED OVER PORTIONS OF
SOUTHERN MINNESOTA INTO SOUTH DAKOTA UNDER THIS BAND. EXPECT THIS
BAND TO PROGRESS SOUTH TODAY AND INTENSIFY AS IT APPROACHES THE
INTERSTATE 90 CORRIDOR. SNOW ACCUMULATIONS OF A FEW TENTHS TO
AROUND AN INCH ARE POSSIBLE WITH THE HIGHER ACCUMULATIONS OCCURRING
OVER NORTHEAST IOWA.
THE COLD FRONT WILL CONTINUE SLIDING SOUTH ACROSS THE AREA TODAY. A
PERIOD LIGHT SNOW IS EXPECTED AS THE FRONT SLIDES THROUGH. MODEL
CROSS SECTIONS ORIENTED NORTH/SOUTH ACROSS THE FRONT SHOW
FRONTOGENESIS EXTENDING FROM 950 MB THROUGH 700 MB WITH WEAK
NEGATIVE EPV NOTED RIGHT AROUND 700 MB. THIS SHOULD PROVIDE ENOUGH
SUPPORT FOR A BAND OF LIGHT SNOW. THE BAND WILL PUSH SOUTHWARD
ACROSS THE FORECAST AREA TODAY AND FINALLY EXIT THE AREA THIS
EVENING. SNOW ACCUMULATIONS WILL RANGE FROM AROUND A TRACE OVER
NORTH CENTRAL WISCONSIN TO AROUND ONE INCH ACROSS PORTIONS OF
NORTHEAST IOWA. ARCTIC AIR WILL INVADE THE FORECAST AREA TODAY IN
THE WAKE OF THE FRONT. 850 MB TEMPERATURES WILL PLUMMET INTO THE
-12 TO -15 C RANGE BY LATE THIS AFTERNOON INTO THIS EVENING. THIS
IS UNSEASONABLY COLD FOR THIS TIME OF YEAR...WITH 850 MB
TEMPERATURE STANDARDIZED ANOMALIES OF -2.0. BREEZY NORTHWEST WINDS
OF 15 TO 25 MPH WITH GUSTS TO AROUND 30 MPH WILL MAKE IT FEEL
RATHER CHILLY TODAY. PLAN ON TEMPERATURES FALLING THROUGH THE
DAY...INTO THE 20S BY THIS AFTERNOON THEN TUMBLING INTO THE TEENS
FOR OVERNIGHT LOWS. CANNOT RULE OUT SOME SINGLE DIGIT READINGS
OVER NORTH CENTRAL WISCONSIN EARLY TUESDAY MORNING. NORTHWEST
WINDS WILL TAPER OFF TONIGHT. HOWEVER SPEEDS OF 5 TO 10 MPH WILL
BE COMMON TONIGHT LEADING TO WIND CHILLS IN THE SINGLE DIGITS
ABOVE ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 306 AM CST MON NOV 11 2013
THE ARCTIC HIGH SLIDES ACROSS THE REGION ON TUESDAY PROVIDING SUNNY
SKIES AND UNSEASONABLY COOL HIGH TEMPERATURES. HIGH TEMPERATURES ON
TUESDAY WILL RANGE FROM THE MID 20S ACROSS NORTH CENTRAL WISCONSIN
AND SOUTHEAST MINNESOTA TO AROUND 30S ACROSS NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN. THE HIGH THEN SLIDES SOUTHEAST OF THE REGION
TUESDAY NIGHT INTO WEDNESDAY AS ZONAL FLOW ALOFT SETS UP OVER THE
AREA. TEMPERATURES MORE TYPICAL OF MID NOVEMBER WILL RETURN TO THE
REGION ON WEDNESDAY ON THE BACK SIDE OF THE DEPARTING HIGH. 850 MB
TEMPERATURES WARM TO AROUND +7 ON WEDNESDAY. HIGH TEMPERATURES ARE
EXPECTED TO RANGE FROM THE UPPER 30S TO LOWER 40S. MOISTURE IS VERY
SLOW TO RETURN ON WEDNESDAY AND WITH A TIGHT PRESSURE GRADIENT
ACROSS THE AREA THERE COULD BE SOME FIRE WEATHER CONCERNS. AFTERNOON
RELATIVE HUMIDITY VALUES ARE EXPECTED TO DROP INTO THE UPPER 20S.
THESE RELATIVE HUMIDITY VALUES COMBINED WITH SOUTHWEST WINDS OF 15
TO 25 MPH COULD LEAD TO HEIGHTENED FIRE DANGER. WILL HAVE TO KEEP A
CLOSE EYE ON THIS THE NEXT FEW MODEL RUNS.
THE NEXT CHANCE FOR PRECIPITATION WILL ARRIVE ON THURSDAY AS A WEAK
SHORTWAVE TROUGH MOVES ACROSS THE REGION. A GRADUALLY WARMING TREND
IS IN STORE FOR THE REGION FOR THE END OF THE WORK WEEK INTO THE
WEEKEND AS A TROUGH DEVELOPS OVER THE SOUTHWEST CONUS. SOUTHWEST
FLOW ALOFT LOOKS TO SET UP ACROSS THE REGION LATE SATURDAY THROUGH
SUNDAY. WARMER AIR IS EXPECTED TO ADVECT NORTHWARD INTO THE UPPER
MISSISSIPPI RIVER VALLEY FOR THE WEEKEND WITH HIGHS CLIMBING INTO
THE UPPER 40S TO LOWER 50S. EMBEDDED SHORTWAVES IN THE SOUTHWEST
FLOW ALOFT WILL BRING CHANCES FOR RAIN TO THE REGION. FORECAST
MODELS ARE SHOWING SOME DIFFERENCES IN STRENGTH AND TIMING OF
THESE FEATURES SO WILL LEAN TOWARD A MODEL CONSENSUS BLEND FOR
PRECIPITATION CHANCES NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1104 PM CST SUN NOV 10 2013
THE COLD FRONT IS MAKING GOOD PROGRESS TO THE SOUTHEAST AND
EXTENDS FROM NORTHWEST WISCONSIN INTO SOUTHWEST MINNESOTA LATE
THIS EVENING. IT LOOKS TO BE A LITTLE FASTER THAN PREVIOUSLY
THOUGHT SO HAVE MOVED THE WIND SHIFT UP AN HOUR FOR BOTH SITES.
THE QUESTION THEN BECOMES WHETHER THE LOW CLOUDS AND LIGHT SNOW
ARE GOING TO FORM BEHIND THE FRONT. STARTING TO SEE A FEW SITES
REPORTING SOME MVFR CEILINGS ACROSS NORTHERN INTO WESTERN
MINNESOTA. WITH THE 11.00Z NAM AND 11.03Z RAP CONTINUING TO SHOW
THE LOW LEVELS BECOMING SATURATED BEHIND THE FRONT...WILL CONTINUE
THE TREND OF BRINGING IN MVFR CEILINGS FOR A FEW HOURS. THE NAM
CAME IN A LITTLE STRONGER WITH THE FRONTOGENESIS IN THE 850-700
MB LAYER THAN THE 10.18Z RUN AND NOW SPITS OUT SOME LIGHT QPF
ACROSS THE AREA. THE NAM ALSO CAME IN STRONGER WITH THE PV
ADVECTION IN THE 500-300 MB LAYER WITH A STRETCHED OUT SECONDARY
SHORT WAVE TROUGH IT BRINGS ACROSS THE AREA AS THE MAIN SHORT WAVE
TROUGH AND UPPER LEVEL LOW STAYS OVER THE GREAT LAKES INTO
ONTARIO. LOOKING AT THE BUFKIT SOUNDINGS...CONCERNED THAT THIS
FORCING MAY BE TOO WEAK TO PRODUCE MUCH BEYOND FLURRIES OR SOME
VERY LIGHT SNOW. THE OMEGA IN THE LOW LEVELS IS PRETTY WEAK WITH
THE STRONGER LIFT IN THE MID LEVELS. FOR NOW...WILL MAINTAIN THE
MVFR VISIBILITY WITH SOME LIGHT SNOW WITH THE LOW CEILINGS. STEEP
LOW LEVEL LAPSE RATES DEVELOP BEHIND THE FRONT TO ALLOW GUSTY
WINDS TO SPREAD ACROSS THE AREA AND THESE THEN LOOK TO REMAIN
THROUGH ALL OF MONDAY UNTIL SUNSET WHEN THE INVERSION SHOULD
DEVELOP AND CUT OFF THE MIXING. THE CEILINGS SHOULD GO BACK UP TO
VFR BY MID MORNING AS THE BAND OF LOW LEVEL MOISTURE MOVES SOUTH
OF THE AREA. THE CLOUDS WILL LIKELY SCATTER/CLEAR OUT FASTER THAN
THE TREND IN THE FORECAST...BUT DID NOT HAVE ANY OTHER CHANGES TO
JUSTIFY ADDING A VFR CHANGE GROUP SO SHOWED THIS HAPPENING WHEN
THE WINDS DIMINISH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1130 PM CST SUN NOV 10 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 953 PM CST SUN NOV 10 2013
CONCERNED ABOUT A POSSIBLE HIGH-IMPACT SUB-ADVISORY (HISA) EVENT
LATE TONIGHT INTO EARLY MONDAY. SNOWFALL SHOULD NOT BE A SIGNIFICANT
PROBLEM...AS ACCUMS SHOULD BE AN INCH OR LESS IN MOST AREAS. HOWEVER...
ROADS THAT ARE WET FROM RAIN OR MELTING SNOW WILL QUICKLY ICE UP
AS ARCTIC AIR ARRIVES. ISSUED AN SPS AND UPDATED THE HWO TO GET THE
WORD OUT.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 230 PM CST SUN NOV 10 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE HIGH
PRESSURE MOVING SOUTHEAST ACROSS THE MID-MISSISSIPPI VALLEY AND LOW
PRESSURE DIVING SE ACROSS NORTHWEST ONTARIO. ATTACHED TO THE
SURFACE LOW IS AN ARCTIC COLD FRONT WHICH IS PUSHING INTO THE
NORTHERN PLAINS. LOW STRATO-CU ACROSS THE NORTH IS FINALLY EXITING
NORTHEAST WISCONSIN AT THE MOMENT...BUT MID AND HIGH CLOUDS ARE
ALREADY MOVING INTO THE STATE. AS A RESULT...CLOUDS WILL BE ON THE
INCREASE FOR THE REST OF THE AFTERNOON. BUT QUICKLY ATTENTION WILL
TURN TO THE ARCTIC FRONT. SNOW SHOWERS ARE OCCURRING ALONG THE
FRONT OVER SOUTHWEST ONTARIO AND FAR NORTHERN MINNESOTA...DROPPING
VSBYS TO 1 1/2SM. TEMPERATURES ARE FALLING BEHIND THE FRONT INTO
THE SINGLE DIGITS AND TEENS ACROSS MANITOBA. WITH THE FRONT
ARRIVING TONIGHT...SNOW CHANCES/ACCUMS AND TEMPERATURES TOMORROW ARE
THE MAIN FORECAST CONCERNS.
TONIGHT...A STRONG SHORTWAVE TROUGH WILL DIVE SOUTHEAST ACROSS
ONTARIO...WITH THE TAIL END OF THE VORT PASSING ACROSS LAKE SUPERIOR
AND THE UPPER PENINSULA. THIS SHORTWAVE WILL PUSH AN ARCTIC FRONT
INTO FAR NORTH-CENTRAL WISCONSIN BY 06Z AND ACROSS THE REST OF THE
FORECAST AREA OVERNIGHT. FORCING IS VERY GOOD ALONG THE
FRONT...WITH STRONG CONVERGENCE...AND DECENT MID-LEVEL FGEN AND
-DIVQ. MOISTURE TRANSPORT AND ISENTROPIC ASCENT AHEAD OF THE FRONT
IS ON THE WEAKER SIDE THOUGH...AND THINK THE NAM MAY BE A LITTLE TOO
AMBITIOUS IN GENERATING PRECIP AHEAD OF THE FRONT. BUT SHOULD SEE A
BKN BAND OF PRECIP RIGHT AHEAD OF THE FRONT THOUGH. BUFKIT
SOUNDINGS INDICATE THAT LOW WET BULB TEMPS SHOULD KEEP PTYPE AS
MOSTLY SNOW OVER CENTRAL AND NORTHEAST WISCONSIN...WHILE PRECIP WILL
LIKELY START OUT AS RAIN OVER EAST-CENTRAL WISCONSIN. THEN PRECIP
WILL CHANGE TO SNOW AS COLDER AIR FILTERS SOUTH. COULD SEE A
DUSTING OVER THE SOUTHEAST FORECAST AREA. MAX OMEGA WILL RESIDE IN
THE DENDRITIC GROWTH ZONE...WHICH SUGGESTS THAT SNOWFALL RATES MAY
BECOME BRIEFLY INTENSE WITHIN THE STRONGER SNOW SHOWERS ACROSS THE
NORTH. BECAUSE THE SNOW SHOWERS WILL LIKELY BE FAST MOVING...TOUGH
TO SEE MUCH MORE THAN AN INCH OF ACCUMULATION. LOWS FALLING INTO
THE LOWER 20S NORTH...BUT ONLY FALLING INTO THE LOWER 30S SOUTHEAST.
MONDAY...ARCTIC AIR WILL QUICKLY FLOOD SOUTHEAST ACROSS THE FORECAST
AREA DURING THE MORNING...AND TEMPS WILL NOT RISE VERY MUCH OFF THE
MORNING LOWS. MAY ACTUALLY SEE TEMPS FALL A BIT DURING THE
MORNING OVER EAST-CENTRAL WISCONSIN. THOUGH THE AIRMASS IS VERY
DRY BEHIND THE FRONT...SHOULD STILL SEE SCATTERED LAKE EFFECT SNOW
SHOWERS ACROSS N-C WISCONSIN DURING THE MORNING WHICH SHOULD NOT
AMOUNT TO MUCH ACCUMULATION. MAY SEE THE SNOW SHOWERS PARTIALLY
DIMINISH IN THE AFTERNOON AS THE DRY AIR ASSERTS ITS INFLUENCE. A
FEW LIGHT SNOW SHOWERS MAY ALSO LINGER ACROSS EAST-CENTRAL WISCONSIN
EARLY IN THE MORNING RIGHT BEHIND THE FRONT. NORTHWEST WINDS WILL
BE BREEZY...AND SHOULD LEAD TO APPARENT TEMPS FALLING INTO THE
SINGLE DIGITS AND TEENS...DESPITE SOME SUNSHINE. MORNING HIGHS IN
THE MID 20S NORTH TO MID 30S SOUTHEAST.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 230 PM CST SUN NOV 10 2013
MODELS IN GENERAL AGREEMENT ON OVERALL PATTERN CHANGE EXPECTED
DURING THIS PERIOD AS WEST UPPER RIDGE/EAST TROF TRANSITIONS TO
WESTERN TROF AND EASTERN RIDGE. OVERALL...LITTLE CHANGE TO THIS
PERIOD.
LINGERING LAKE EFFECT SNOW SHOWERS OR FLURRIES IN THE LK SUPERIOR
SNOWBELT EARLY IN PERIOD...BUT WINDS BACK QUICKLY ENDING THREAT.
WARM AIR ADVECTION ON BACKSIDE OF RETREATING ARCTIC RIDGE AT THE
SURFACE...ENHANCED BY LIFT FROM WEAK WAVE PRODUCES A PERIOD OF
LIGHT
PRECIPITATION...MAINLY RAIN...LATE THU INTO EARLY FRI.
AS RIDGE MOVES OFF EAST COAST...DEEPER MOISTURE INFLUX NOTED.
ANOTHER WAVE IN SW FLOW PRODUCES LARGER AREA OF RAIN...CLIPPING
THE EASTERN 2/3RDS OF WISCONSIN NEXT WEEKEND.
SW FLOW WILL USHER IN MILDER TEMPS AFTER TUE...WITH TEMPS ABOVE
NORMS BY END OF WEEK. TEMP FORECAST A BLEND OF BEST PERFORMING
GUIDANCE.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1119 PM CST SUN NOV 10 2013
A STRONG ARCTIC COLD FRONT WILL MOVE THROUGH THE FORECAST AREA
OVERNIGHT INTO EARLY MONDAY...BRINGING GUSTY NW WINDS...FALLING
TEMPS AND SOME LIGHT SNOW. RAIN WILL BE POSSIBLE EARLY IN THE TAF
PERIOD AT ATW/GRB. THE SNOW WILL BE HEAVIEST WHEN THE FRONT MOVES
THROUGH...WITH VSBYS DROPPING TO AS LOW AS 1SM-2SM. MVFR/IFR
CONDITIONS WILL OCCUR WITH THE SNOW...AND SOME MVFR CIGS WILL
LINGER OVER THE REGION FOR A WHILE MONDAY MORNING. LAKE-EFFECT
SNOW SHOWERS AND ASSOCIATED MVFR CONDITIONS SHOULD CONTINUE OVER
NC WI THROUGH THE DAY...WHILE THE REST OF THE REGION SEES AN
IMPROVEMENT TO VFR CONDITIONS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......JKL
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1104 PM CST SUN NOV 10 2013
.SHORT TERM...(TONIGHT AND TUESDAY)
ISSUED AT 230 PM CST SUN NOV 10 2013
AN UPPER LEVEL TROUGH WILL SWEEP EASTWARD ACROSS SOUTHEAST CANADA
TONIGHT/MONDAY. ITS ASSOCIATED COLD FRONT WILL SAG SOUTHWARD THROUGH
THE UPPER MISSISSIPPI RIVER VALLEY OVERNIGHT...ALREADY SOUTH OF THE
FORECAST AREA BY 12Z. TWO CONCERNS WITH THIS FRONT...JUST HOW COLD
IT WILL GET AND IF THERE WILL BE ANY CHANCE FOR PCPN.
FIRST...SIGNIFICANTLY COLDER AIR WILL FOLLOW IN THE WAKE OF THE
FRONT. 850 MB TEMPS PROGGED TO DROP FROM AROUND 3 C AT 00Z TONIGHT
TO -13 C BY 00Z SUN EVENING. 850 MB TEMP SREF ANOMALIES ARE AROUND
-1.5 MON-TUE. HIGHS FOR MONDAY WILL LIKELY BE THE MIDNIGHT
TEMPERATURE TONIGHT...WITH SLOWLY FALLING TO STEADY TEMPERATURES THE
REST OF THE DAY. HIGH PRESSURE DROPS ACROSS THE NORTHERN PLAINS
SUNDAY NIGHT...RESULTING IN CLEAR/PARTLY CLOUDY SKIES FOR MOST OF
THE REGION. THE FORECAST AREA IS STILL UNDER A SFC PRESSURE GRADIENT
THOUGH...KEEPING WINDS UP A BIT...AND THUS NOT AN IDEAL RADIATIONAL
COOLING NIGHT. STILL...TEMPERATURES WILL TUMBLE AND EXPECTING THE
COLDEST MORNING OF THE SEASON. TUE WILL FEEL MORE LIKE MID DECEMBER
RATHER THAN EARLY NOV.
SECOND...FOR PCPN...THE BULK OF THE UPPER LEVEL ENERGY STAYS WELL
NORTH...BUT THERE IS SOME ELONGATED PIECES OF ENERGY THAT STRETCH
WESTWARD ALONG THE LEADING EDGE OF THE TROUGH...TRAILING THE SFC
COLD FRONT. A NORTH-SOUTH RUNNING X-SECTION VIA THE GFS AND NAM SHOW
A DECENT SLOPING FRONTOGENETIC RESPONSE WITH THE FRONT...STRONGEST
POST THE FRONT BETWEEN 12-18Z. SOME SLOPING QG CONVERGENCE ALSO WITH
THE SYSTEM...WHILE ALL THE WARM AIR ADVECTION/ISENTROPIC UPGLIDE IS
AHEAD OF THE FRONT...AND THUS SOUTH OF THE FORECAST AREA BY 12Z.
SOME HINTS OF HELP WITH LIFT FROM THE 300 MB JET...MOSTLY FOR
NORTHEAST WI OVERNIGHT.
PLENTY OF LIFT FOR PCPN...BUT HOW MUCH SATURATION IT WILL HAVE TO
WORK WITH BRINGS A LOT OF QUESTION MARKS. THE NORTH-SOUTH X-SECTIONS
POINT TO A SMALL WINDOW OF DEEPER SATURATION...ALONG AND BEHIND THE
FRONT. THE COLDER/DRIER PUSH OF LOW/MID LEVEL AIR QUICKLY DRIVES
INTO THE SATURATION...LIKELY PROVIDING AN EFFECTIVE DETERRENT TO
ANYTHING REACHING THE GROUND. BUT THERE IS A 3-4 HOUR WIND WHERE
EVERYTHING COMES TOGETHER AND LIGHT/VERY LIGHT PCPN WOULD BE LIKELY.
BUFKIT SOUNDINGS SUPPORT SNOW. DON/T SEE MUCH IF ANY
ACCUMULATION...WITH MINIMAL QPF IN LATEST MODEL RUNS AND SREF
PROBABILITIES. IT COULD END UP BEING A FEW HOUR PERIOD OF
FLURRIES/VERY LIGHT SNOW WITH ONLY TRACE ACCUMULATIONS TO A TENTH OR
TWO. THE EARLY/MID MORNING TIME FRAME WOULD BE FAVORED BASED ON
CURRENT TIMING VIA THE GFS/NAM/EC.
ONE CAVEAT TO POINT OUT FOR THE PCPN CHANCES TONIGHT. SOME MESO
MODELS SUGGEST SOME LIGHT PCPN COULD COME OUT OF THE MASS OF MID
LEVEL CLOUDS MOVING IN FROM THE WEST. THIS WOULD BE TRIGGERED BY
INCREASING ISENTROPIC UPGLIDE ALONG WITH SOME 850 MB MOISTURE
TRANSPORT. CHANCES WOULD STAY MOSTLY EAST OF THE MISSISSIPPI RIVER.
CONFIDENCE LOW AT THIS TIME...SO WILL NOT ADD TO THE FORECAST. IF IT
WOULD OCCUR...PROBABLY ONLY SPRINKLES. TRENDS WILL HAVE TO BE
MONITORED.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 230 PM CST SUN NOV 10 2013
GFS/ECMWF IN GOOD AGREEMENT WITH SHIFTING THE UPPER LEVEL PATTERN TO
MORE ZONAL BY THE MIDDLE OF NEXT WEEK...WITH A MORE PERSISTENT
SOUTHWEST TO WESTERN FLOW OF AIR. TEMPERATURES WILL MODERATE BACK TO
THE SEASONABLE NORMALS...PERHAPS EVEN A FEW DEGREES ABOVE NORMAL.
THE BULK OF THE SHORTWAVE ACTIVITY IN THE FLOW WILL STAY NORTH OR
SOUTH OF THE REGION. HOWEVER...THE GFS AND EC BOTH FAVOR SWINGING A
PIECE OF UPPER LEVEL ENERGY FROM THE SOUTHERN PLAINS NORTHEAST
ACROSS THE GREAT LAKES SAT/SUN. WHILE THE BRUNT OF THE PCPN CHANCES
WITH THIS FEATURE WOULD CURRENTLY STAY SOUTH/EAST OF THE FORECAST
AREA...ITS TRACK WOULD BE CLOSE ENOUGH TO BRING AT LEAST A SMALL
THREAT FOR SOME SHOWERS. COULD BE RAIN OR SNOW DEPENDING ON TIMING.
THE GFS IS THE PERKIER OF THE MODELS. WILL STICK WITH CONSENSUS
SOLUTION FOR CHANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1104 PM CST SUN NOV 10 2013
THE COLD FRONT IS MAKING GOOD PROGRESS TO THE SOUTHEAST AND
EXTENDS FROM NORTHWEST WISCONSIN INTO SOUTHWEST MINNESOTA LATE
THIS EVENING. IT LOOKS TO BE A LITTLE FASTER THAN PREVIOUSLY
THOUGHT SO HAVE MOVED THE WIND SHIFT UP AN HOUR FOR BOTH SITES.
THE QUESTION THEN BECOMES WHETHER THE LOW CLOUDS AND LIGHT SNOW
ARE GOING TO FORM BEHIND THE FRONT. STARTING TO SEE A FEW SITES
REPORTING SOME MVFR CEILINGS ACROSS NORTHERN INTO WESTERN
MINNESOTA. WITH THE 11.00Z NAM AND 11.03Z RAP CONTINUING TO SHOW
THE LOW LEVELS BECOMING SATURATED BEHIND THE FRONT...WILL CONTINUE
THE TREND OF BRINGING IN MVFR CEILINGS FOR A FEW HOURS. THE NAM
CAME IN A LITTLE STRONGER WITH THE FRONTOGENESIS IN THE 850-700
MB LAYER THAN THE 10.18Z RUN AND NOW SPITS OUT SOME LIGHT QPF
ACROSS THE AREA. THE NAM ALSO CAME IN STRONGER WITH THE PV
ADVECTION IN THE 500-300 MB LAYER WITH A STRETCHED OUT SECONDARY
SHORT WAVE TROUGH IT BRINGS ACROSS THE AREA AS THE MAIN SHORT WAVE
TROUGH AND UPPER LEVEL LOW STAYS OVER THE GREAT LAKES INTO
ONTARIO. LOOKING AT THE BUFKIT SOUNDINGS...CONCERNED THAT THIS
FORCING MAY BE TOO WEAK TO PRODUCE MUCH BEYOND FLURRIES OR SOME
VERY LIGHT SNOW. THE OMEGA IN THE LOW LEVELS IS PRETTY WEAK WITH
THE STRONGER LIFT IN THE MID LEVELS. FOR NOW...WILL MAINTAIN THE
MVFR VISIBILITY WITH SOME LIGHT SNOW WITH THE LOW CEILINGS. STEEP
LOW LEVEL LAPSE RATES DEVELOP BEHIND THE FRONT TO ALLOW GUSTY
WINDS TO SPREAD ACROSS THE AREA AND THESE THEN LOOK TO REMAIN
THROUGH ALL OF MONDAY UNTIL SUNSET WHEN THE INVERSION SHOULD
DEVELOP AND CUT OFF THE MIXING. THE CEILINGS SHOULD GO BACK UP TO
VFR BY MID MORNING AS THE BAND OF LOW LEVEL MOISTURE MOVES SOUTH
OF THE AREA. THE CLOUDS WILL LIKELY SCATTER/CLEAR OUT FASTER THAN
THE TREND IN THE FORECAST...BUT DID NOT HAVE ANY OTHER CHANGES TO
JUSTIFY ADDING A VFR CHANGE GROUP SO SHOWED THIS HAPPENING WHEN
THE WINDS DIMINISH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS DES MOINES IA
333 AM CST WED NOV 13 2013
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
SURFACE HIGH CURRENTLY OVER SOUTH CENTRAL MISSOURI WILL CONTINUE TO
SHIFT OFF TO THE SOUTHEAST TODAY. ALOFT THE FLOW WILL BECOME
WESTERLY ACROSS THE REGION AS THE RIDGE AXIS SHIFTS EAST AND A
SHORTWAVE DEEPENS OVER THE INTERMOUNTAIN WEST AND HIGH PLAINS. THE
SHORTWAVE WILL BUCKLE THE UPPER FLOW PUTTING IOWA IN A ZONAL FLOW.
THE COMBINATION OF RETURN FLOW AT THE SURFACE AND A ZONAL FLOW ALOFT
MEANS WARMING TEMPS FOR CENTRAL IOWA. THE CAVEATS TO THIS IS THAT
THE NAM MODEL HAS A RIDICULOUS AND ERRONEOUS CALCULATION OF NEARLY
TWO INCHES OF SNOW DEPTH OVER CENTRAL IOWA THUS KEEPING TEMPS WAY
TOO COOL AND MESSING WITH WIND FIELDS AS WELL.
THE RAP AND GFS HAVE A BETTER HANDLE ON SNOW FIELDS. SOUNDINGS ARE
DRY SO IT SHOULD BE A SUNNY DAY TODAY. THERE IS A STRONG NOSE OF
WARM AIR ALOFT AND AN EQUALLY STRONG INVERSION SO WE WILL NOT
REALIZE THE AMOUNT OF WARMTH WE COULD HAVE BUT EVEN IF WE ONLY MIX
TO 925 MB WE WILL TAP SOME OF THE WARMER AIR. NEXT IS SNOW ON THE
GROUND. SATELLITE PIX STILL SHOW A SWATH OF SNOW ACROSS NORTHERN
IOWA FROM ALGONA TO JUST NORTH OF WATERLOO AND NORTH OF THAT LINE.
ANOTHER STRIPE OF SNOW FROM AUDUBON TO KNOXVILLE TO OTTUMWA WAS
EVIDENT SO WHILE THIS WILL NOT BE A SHOW STOPPER FOR A WARM
UP...HIGHS IN THOSE LOCATIONS WILL LIKELY BE A DEGREE OR TWO COLDER
THAN SURROUNDING AREA. I HAVE ADJUSTED HIGHS ACCORDINGLY IN THOSE
LOCATIONS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
ALTHOUGH THERE IS STILL A TOKEN WINDOW FOR PRECIP THU...THE PRIMARY
CONCERN THROUGH THE PERIOD REMAINS OVER THE WEEKEND AND INTO
EARLY NEXT WEEK. SKIES WILL REMAIN MOSTLY CLEAR INTO TONIGHT WITH
TEMPERATURES MODERATING BACK TO SEASONAL LEVELS. ATTENTION TURNS
TO CURRENT WA/BC SHORT WAVE WHICH SHOULD REACH THE MO VALLEY EARLY
THU. SOMEWHAT DEEP WEAK AND BRIEFLY MODERATE FORCING MOVES
THROUGH THU BUT MOISTURE IS QUITE LIMITED. THE ONLY POTENTIAL FOR
SATURATION IS ABOVE 3KM AND EVEN THAT IS SUSPECT. EXAMINATION OF
295-305K ISENT LAYERS SHOW JUST A NARROW RIBBON OF MOISTURE AND
MOISTURE TRANSPORT WHICH WILL LIKELY GENERATE AT LEAST SOME VIRGA.
PLENTY OF DRY AIR UNDERNEATH WILL DIMINISH MEASURABLE POTENTIAL
HOWEVER SO HAVE OPTED FOR A PERIOD OF SPRINKLES WORDING...MAINLY
NE.
AFTER A BRIEF BREAK INTO FRIDAY PATTERN SHIFT WILL DEVELOP WITH
PRONOUNCED WRN CONUS TROUGH...INITIALLY HELPED BY CURRENT GULF OF AK
SHORT WAVE. THIS WAVE WILL REACH THE FOUR CORNERS AREA BY LATE FRI
AND EVENTUALLY IA SAT. THIS WILL INTRODUCE POPS AS EARLY AS AFTER
MIDNIGHT SATURDAY WITH KINEMATIC FORCING AND A RATHER STRONG SURGE
OF THERMODYNAMIC FORCING/THETA-E ADVECTION. ALTHOUGH NOT INCLUDED
AS OF YET...WOULD NOT BE SURPRISED TO SEE SOME RUMBLES OF THUNDER
AS K INDICES ELEVATE AND MUCAPES REACH A FEW HUNDRED.
LONG WAVE TROUGH THEN ADVANCES INTO THE CENTRAL CONUS AND
SIGNIFICANT QUESTIONS STILL REMAIN. THE GENERAL PROGRESSION
REMAINS SOMEWHAT SIMILAR FROM ECMWF...GFS TO GEM WITH SURFACE LOW
BRUSHING SE IA FOLLOWED BY STRONG COLD ADVECTION AND WINDY
CONDITIONS. TIMING IS STILL SUSPECT HOWEVER AS RUN TO RUN CHANGES
CONTINUE TO BE FASTER WITH NO APPARENT TIMING CONSENSUS DEVELOPING
AS OF YET. PRECIP TYPE IS OBVIOUSLY A BIG CONCERN AND THESE TIMING
DIFFERENCES RESULT IN DIFFERENT SCENARIOS BUT THE MAIN TREND IS
TOWARD MORE RAIN THAN SNOW. GFS FORCING SURGE COINCIDES WITH
SOMEWHAT WARMER TEMPS AND MORE RAIN...WHILE SLOWER ECMWF WOULD
SUGGEST ONLY POTENTIAL FOR SNOW ACROSS NW HALF OF FORECAST AREA ON
THE TRAILING END OF DEFORMATION ZONE. MUCH LIKE YESTERDAY THIS LOW
CONFIDENCE HAS RESULTED IN A TIME LAGGED MODEL CONSENSUS...A BLEND
OF CURRENT AND PREVIOUS RUN TO REDUCE FORECAST CHANGES. THIS
SENSIBLE WEATHER RESULT HAS RAIN SUNDAY AND SUNDAY EVENING...WITH
A BRIEF TRANSITION TO SNOW EARLY MON. LOW END POPS STILL LINGER
INTO THE DAY MON...BUT CONSIDERING FASTER TIMING TRENDS THESE MAY
NEED TO BE REDUCED OR ELIMINATED LATER TODAY.
A FEW THINGS TO MENTION REGARDING TEMPS. 00Z NAM SNOW DEPTH
INITIALIZATION WAS HORRIBLE AS IT CURRENTLY DEPICTS 1-2 INCHES FROM
I80 TO MN BORDER AND ONLY DROPS IT TO AROUND A HALF INCH BY THU.
DOES NOT REALLY GET RID OF IT UNTIL FRI NIGHT. LAST FEW VISIBLE
SATELLITE IMAGES SHOW LINGERING NARROW BAND OF SNOW N OF
ADAIR-INDIANOLA-FAIRFIELD NEARLY GONE...AND ONLY NRN IA SNOW ALONG
AND NORTH OF SPIRIT LAKE-WAVERLY LINE. FEEL THESE EFFECTS SHOULD BE
MINIMIZED BY THU AND ARE NOT INCLUDED IN TEMPS THIS PERIOD. MARKED
DIFFERENCE IN AIRMASS WILL BE NOTED BY THE WEEKEND WITH HIGHS BACK
INTO THE 50S MOST AREAS AND DEWPOINTS WELL INTO THE 40S AND ABOVE
50 CENTRAL AND SE. MON LOOKS SHARPLY COLDER WITH 20F PLUS TEMP
DROP AND BRISK NW WINDS. TEMPS WILL BE BACK TO RECENT COOL LEVELS
BY MON NIGHT.
&&
.AVIATION...13/06Z
ISSUED AT 1117 PM CST TUE NOV 12 2013
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD. LIGHT SOUTHWEST
WINDS OVERNIGHT WILL BECOME BREEZY BY LATE MORNING WEDNESDAY. A
FEW GUSTS NEAR 30 KTS WILL BE POSSIBLE. THE GUSTS WILL DIMINISH
TOWARD SUNSET.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...SMALL
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1234 AM EST WED NOV 13 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE FROM AZ/UT TO SASK AND A TROUGH OVER THE ERN
CONUS RESULTING IN NRLY FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WINDS WERE BACKING WRLY OVER UPPER MI AS THE LARGE HIGH PRES
SETTLES THROUGH ERN KS. LES INTO THE NE PORTION OF THE CWA
WAS QUICKLY DIMINISHING AS WINDS SHIFTED TO THE WEST AND VERY DRY
AIR WITH LOWERING INVERSION HEIGHTS MOVE ACROSS LAKE SUPERIOR.
TONIGHT...ANY LINGERING LES WILL END BY LATE THIS EVENING AS WINDS
BECOME OFFSHORE. RADIATIONAL COOLING WILL HELP TEMPS DROP INTO THE
TEENS OVER INLAND LOCATIONS. HOWEVER...INCREASING MID HIGH CLOUDS
SUPPORTED BY WAA WITH 300K-305K ISENTROPIC LIFT SPREADING ACROSS
UPPER MI AND INCREASING SW WINDS WILL LIMIT COOLING OVERNIGHT.
WED...THE PRES GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN THE HIGH
SINKING INTO THE SRN CONUS AND LOW PRES MOVING TOWARD JAMES BAY.
HOWVER...STRONG 925-850 MB WAA WILL INCREASE STABILITY ENOUGH TO
LIMIT SFC WIND GUSTS. NAM BUFKIT MOMENTUM TRANSFER SUGGESTS WINDS
COULD STILL GUST INTO THE 25-30 KT RANGE OVER MUCH OF THE CWA. THE
STABILITY AND INCREASING STRONG/LOW INVERSION HEIGHT WILL KEEP TEMPS
IN THE UPPER 30S AND LOWER 40S EVEN AS 925/850 MB TEMPS CLIMB INTO
THE 8C-10C RANGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
UPPER RIDGE OVER THE AREA ON WEDNESDAY WILL FLATTEN AND SHIFT EAST
AS A SHORTWAVE DIVES EAST-SOUTHEAST ACROSS CENTRAL CANADA. A LOW
ASSOCIATED WITH THIS WAVE WILL BE OVER JAMES BAY AT THE START OF THE
PERIOD AND THEN SHIFT EAST ACROSS QUEBEC ON THURSDAY. AS THIS
OCCURS...IT WILL SLOWLY DRAG A COLD FRONT ACROSS UPPER MICHIGAN
WEDNESDAY NIGHT AND THURSDAY. MOISTURE (DRY AIR BETWEEN 850-700MB)
AND FORCING STILL LOOK TO BE VERY LIMITED WEDNESDAY NIGHT AND INTO
MUCH OF THURSDAY. BUT AS A SECONDARY SHORTWAVE MOVES OUT OF THE
NORTHERN PLAINS ON THURSDAY AFTERNOON AND NIGHT (AND PROVIDES
ADDITIONAL MOISTURE)...THINK THERE SHOULD BE SOME EXPANSION OF THE
SHOWERS OVER THE AREA. THE TRACK OF THE SHORTWAVE AND SUBSEQUENT
WEAK LOW DEVELOPMENT WILL DETERMINE THE LOCATION OF THE
SHOWERS...BUT MOST OF THE MODELS INDICATE THE TRACK BEING ACROSS THE
NORTHERN HALF OF UPPER MICHIGAN OR LAKE SUPERIOR. WILL HAVE THE
HIGHEST POPS FOR THAT AREA. THERE AREA ALSO DIFFERENCES ON THE
AMOUNT OF COLD AIR AVAILABLE WITH THE WESTERLY WINDS ACROSS LAKE
SUPERIOR...SO NOT OVERLY CONFIDENT ON THE POTENTIAL FOR LAKE
ENHANCEMENT FOR THE KEWEENAW ON FRIDAY...BUT FEEL HAVING CHANCE POPS
IS REASONABLE. HAVE KEPT P-TYPE MAINLY RAIN THROUGH THAT
PERIOD...FIRST DUE TO THE WARM LAYER AROUND 850MB WED NIGHT INTO
THURSDAY AND THEN DUE TO QUESTIONS ON AMOUNT OF COLD AIR AND ICE
PRESENT IN THE CLOUDS FOR THURS NIGHT INTO FRIDAY. HIGHS LOOK TO BE
AROUND 40 DURING THAT PERIOD AND LOWS AROUND 30.
WILL DEFINITELY NEED TO KEEP AN EYE ON THE FORECAST FOR THE END OF
THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A STRONG SHORTWAVE
DIVING SOUTH FROM ALASKA WILL AMPLIFY THE POLAR JET OVER THE
ROCKIES AT THE START OF THE WEEKEND. BROAD SOUTHWESTERLY FLOW AHEAD
OF THIS AMPLIFYING TROUGH WILL LIKELY LEAD TO A PERIOD OF RAIN
LATER SATURDAY INTO SUNDAY UNDER THE WARM AIR ADVECTION AHEAD OF A
SURFACE TROUGH STRETCHING FROM THE NORTHERN PLAINS TO HUDSON BAY.
THEN...AS THE SHORTWAVE ROUNDS THE TROUGH AND EJECTS INTO THE GREAT
LAKES REGION SUNDAY NIGHT INTO MONDAY...IT APPEARS THAT THE REGION
WILL SEE A LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. AT THIS FAR
OUT...THERE IS STILL A LOT OF UNCERTAINTY...BUT THE POTENTIAL IS
THERE AT THIS POINT FOR MEASURABLE SNOW OVER THE WESTERN HALF OF
UPPER MICHIGAN. COLDER AIR MOVING IN BEHIND THE LOW FOR TUESDAY
(AROUND -15C AT 850MB) WOULD SUPPORT LAKE EFFECT SNOW IN THE
NORTHWEST WIND BELTS AND DID TREND POPS UP SOME FOR THE FAVORED
LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1233 AM EST WED NOV 13 2013
WITH DRY AIR MASS DOMINATING...VFR CONDITIONS WILL BE THE RULE AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD. HOWEVER...SOME LOW CLOUDS/MVFR
CIGS MAY DEVELOP AT KCMX NEAR THE END OF THE FCST PERIOD AS A SFC
TROF DROPS ACROSS LAKE SUPERIOR. UNDER TIGHTENING PRES GRADIENT...
WINDS WILL STRENGTHEN ABOVE SFC BASED INVERSION...RESULTING IN LLWS
AT KIWD AND KSAW OVERNIGHT. GUSTY WRLY WINDS WILL CONTINUE AT KCMX.
GUSTY WINDS TO 25-30KT ARE EXPECTED AT ALL TERMINALS TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST TUE NOV 12 2013
EXPECT GALE FORCE WINDS FROM LATE WED MORNING THROUGH WED EVENING
OVER WRN LAKE SUPERIOR AS A STRONG HIGH PRESSURE SYSTEM TO THE SOUTH
CREATES A TIGHT PRESSURE GRADIENT WITH A TROUGH PASSING BY TO THE
NORTH IN ONTARIO. WINDS NEAR GALE STRENGTH ARE ALSO POSSIBLE OVER
CNTRL LAKE SUPERIOR BUT SHOULD DIMINISH OVERNIGHT AS THE GRADIENT
WEAKENS. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 10 AM THIS MORNING TO 11 PM EST THIS EVENING
FOR LSZ242>245-265>267.
GALE WARNING FROM 5 AM EST /4 AM CST/ EARLY THIS MORNING TO 8 PM
EST /7 PM CST/ THIS EVENING FOR LSZ162.
GALE WARNING FROM 5 AM EARLY THIS MORNING TO 11 PM EST THIS
EVENING FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING FROM 10 AM THIS MORNING TO 1 AM EST THURSDAY FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1148 PM EST TUE NOV 12 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITH
A MID/UPPER LEVEL RIDGE FROM AZ/UT TO SASK AND A TROUGH OVER THE ERN
CONUS RESULTING IN NRLY FLOW THROUGH THE WRN GREAT LAKES. AT THE
SFC...WINDS WERE BACKING WRLY OVER UPPER MI AS THE LARGE HIGH PRES
SETTLES THROUGH ERN KS. LES INTO THE NE PORTION OF THE CWA
WAS QUICKLY DIMINISHING AS WINDS SHIFTED TO THE WEST AND VERY DRY
AIR WITH LOWERING INVERSION HEIGHTS MOVE ACROSS LAKE SUPERIOR.
TONIGHT...ANY LINGERING LES WILL END BY LATE THIS EVENING AS WINDS
BECOME OFFSHORE. RADIATIONAL COOLING WILL HELP TEMPS DROP INTO THE
TEENS OVER INLAND LOCATIONS. HOWEVER...INCREASING MID HIGH CLOUDS
SUPPORTED BY WAA WITH 300K-305K ISENTROPIC LIFT SPREADING ACROSS
UPPER MI AND INCREASING SW WINDS WILL LIMIT COOLING OVERNIGHT.
WED...THE PRES GRADIENT WILL TIGHTEN SIGNIFICANTLY BETWEEN THE HIGH
SINKING INTO THE SRN CONUS AND LOW PRES MOVING TOWARD JAMES BAY.
HOWVER...STRONG 925-850 MB WAA WILL INCREASE STABILITY ENOUGH TO
LIMIT SFC WIND GUSTS. NAM BUFKIT MOMENTUM TRANSFER SUGGESTS WINDS
COULD STILL GUST INTO THE 25-30 KT RANGE OVER MUCH OF THE CWA. THE
STABILITY AND INCREASING STRONG/LOW INVERSION HEIGHT WILL KEEP TEMPS
IN THE UPPER 30S AND LOWER 40S EVEN AS 925/850 MB TEMPS CLIMB INTO
THE 8C-10C RANGE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EST TUE NOV 12 2013
UPPER RIDGE OVER THE AREA ON WEDNESDAY WILL FLATTEN AND SHIFT EAST
AS A SHORTWAVE DIVES EAST-SOUTHEAST ACROSS CENTRAL CANADA. A LOW
ASSOCIATED WITH THIS WAVE WILL BE OVER JAMES BAY AT THE START OF THE
PERIOD AND THEN SHIFT EAST ACROSS QUEBEC ON THURSDAY. AS THIS
OCCURS...IT WILL SLOWLY DRAG A COLD FRONT ACROSS UPPER MICHIGAN
WEDNESDAY NIGHT AND THURSDAY. MOISTURE (DRY AIR BETWEEN 850-700MB)
AND FORCING STILL LOOK TO BE VERY LIMITED WEDNESDAY NIGHT AND INTO
MUCH OF THURSDAY. BUT AS A SECONDARY SHORTWAVE MOVES OUT OF THE
NORTHERN PLAINS ON THURSDAY AFTERNOON AND NIGHT (AND PROVIDES
ADDITIONAL MOISTURE)...THINK THERE SHOULD BE SOME EXPANSION OF THE
SHOWERS OVER THE AREA. THE TRACK OF THE SHORTWAVE AND SUBSEQUENT
WEAK LOW DEVELOPMENT WILL DETERMINE THE LOCATION OF THE
SHOWERS...BUT MOST OF THE MODELS INDICATE THE TRACK BEING ACROSS THE
NORTHERN HALF OF UPPER MICHIGAN OR LAKE SUPERIOR. WILL HAVE THE
HIGHEST POPS FOR THAT AREA. THERE AREA ALSO DIFFERENCES ON THE
AMOUNT OF COLD AIR AVAILABLE WITH THE WESTERLY WINDS ACROSS LAKE
SUPERIOR...SO NOT OVERLY CONFIDENT ON THE POTENTIAL FOR LAKE
ENHANCEMENT FOR THE KEWEENAW ON FRIDAY...BUT FEEL HAVING CHANCE POPS
IS REASONABLE. HAVE KEPT P-TYPE MAINLY RAIN THROUGH THAT
PERIOD...FIRST DUE TO THE WARM LAYER AROUND 850MB WED NIGHT INTO
THURSDAY AND THEN DUE TO QUESTIONS ON AMOUNT OF COLD AIR AND ICE
PRESENT IN THE CLOUDS FOR THURS NIGHT INTO FRIDAY. HIGHS LOOK TO BE
AROUND 40 DURING THAT PERIOD AND LOWS AROUND 30.
WILL DEFINITELY NEED TO KEEP AN EYE ON THE FORECAST FOR THE END OF
THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A STRONG SHORTWAVE
DIVING SOUTH FROM ALASKA WILL AMPLIFY THE POLAR JET OVER THE
ROCKIES AT THE START OF THE WEEKEND. BROAD SOUTHWESTERLY FLOW AHEAD
OF THIS AMPLIFYING TROUGH WILL LIKELY LEAD TO A PERIOD OF RAIN
LATER SATURDAY INTO SUNDAY UNDER THE WARM AIR ADVECTION AHEAD OF A
SURFACE TROUGH STRETCHING FROM THE NORTHERN PLAINS TO HUDSON BAY.
THEN...AS THE SHORTWAVE ROUNDS THE TROUGH AND EJECTS INTO THE GREAT
LAKES REGION SUNDAY NIGHT INTO MONDAY...IT APPEARS THAT THE REGION
WILL SEE A LOW PRESSURE SYSTEM MOVING THROUGH THE AREA. AT THIS FAR
OUT...THERE IS STILL A LOT OF UNCERTAINTY...BUT THE POTENTIAL IS
THERE AT THIS POINT FOR MEASURABLE SNOW OVER THE WESTERN HALF OF
UPPER MICHIGAN. COLDER AIR MOVING IN BEHIND THE LOW FOR TUESDAY
(AROUND -15C AT 850MB) WOULD SUPPORT LAKE EFFECT SNOW IN THE
NORTHWEST WIND BELTS AND DID TREND POPS UP SOME FOR THE FAVORED
LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1147 PM EST TUE NOV 12 2013
WITH DRY AIR MASS DOMINATING...VFR CONDITIONS WILL BE THE RULE AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD. HOWEVER...SOME LOW CLOUDS/MVFR
CIGS MAY DEVELOP AT KCMX NEAR THE END OF THE FCST PERIOD AS A SFC
TROF DROPS ACROSS LAKE SUPERIOR. UNDER TIGHTENING PRES GRADIENT...
WINDS WILL STRENGTHEN ABOVE SFC BASED INVERSION...RESULTING IN LLWS
AT KIWD AND KSAW OVERNIGHT. GUSTY WRLY WINDS WILL CONTINUE AT KCMX.
GUSTY WINDS TO 25-30KT ARE EXPECTED AT ALL TERMINALS TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST TUE NOV 12 2013
EXPECT GALE FORCE WINDS FROM LATE WED MORNING THROUGH WED EVENING
OVER WRN LAKE SUPERIOR AS A STRONG HIGH PRESSURE SYSTEM TO THE SOUTH
CREATES A TIGHT PRESSURE GRADIENT WITH A TROUGH PASSING BY TO THE
NORTH IN ONTARIO. WINDS NEAR GALE STRENGTH ARE ALSO POSSIBLE OVER
CNTRL LAKE SUPERIOR BUT SHOULD DIMINISH OVERNIGHT AS THE GRADIENT
WEAKENS. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW 30 KNOTS
THROUGH SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 10 AM TO 11 PM EST WEDNESDAY FOR LSZ242>245-
265>267.
GALE WARNING FROM 5 AM EST /4 AM CST/ TO 8 PM EST /7 PM CST/
WEDNESDAY FOR LSZ162.
GALE WARNING FROM 5 AM TO 11 PM EST WEDNESDAY FOR LSZ263-264.
LAKE MICHIGAN...
GALE WARNING FROM 10 AM WEDNESDAY TO 1 AM EST THURSDAY FOR
LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1215 AM CST WED NOV 13 2013
.UPDATE...
ISSUED AT 1214 AM CST WED NOV 13 2013
AS OF O6 UTC...A WARM FRONT WAS LOCATED FROM APPROXIMATELY PIERRE
SOUTH DAKOTA THROUGH WILLISTON...AND WILL CONTINUE TO PROPAGATE
EAST THROUGH THE NIGHT. THIS WILL RESULT IN SLOWLY RISING
TEMPERATURES THROUGH THE NIGHT. NO CHANGES WERE NEEDED TO THE
FORECAST OTHER THAN TO BLEND TO THE 05-06 UTC OBSERVED TRENDS.
UPDATE ISSUED AT 940 PM CST TUE NOV 12 2013
NO SIGNIFICANT UPDATES TO THE LATE EVENING FORECAST. LATEST
OBSERVATIONS SHOW TEMPERATURES DROPPING CLOSE TO OVERNIGHT LOWS IN
SOME AREAS. BUT WITH A MODERATE SOUTHERLY FLOW...DO NOT THINK
TEMPERATURES WILL FALL OFF MUCH TONIGHT. DID LOWER TEMPERATURES IN
SOME AREAS WHERE TEMPERATURES WERE WITHIN A DEGREE OR SO OF
MINIMUM TEMPERATURES AS SKY COVER REMAINS MINIMAL AND WINDS COULD
DIMINISH A BIT LATER TONIGHT BEFORE SHIFTING WEST. OVERALL VERY
FEW CHANGES TO THE GOING FORECAST.
UPDATE ISSUED AT 638 PM CST TUE NOV 12 2013
MAINLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS EVENING. LATEST SATELLITE IMAGERY SHOWS A SHORTWAVE OVER
ALBERTA WHICH WILL TRACK ACROSS SASKATCHEWAN AND INTO MANITOBA BY
EARLY WEDNESDAY MORNING. THE SURFACE LOW ASSOCIATED WITH THIS
WAVE WILL BRING A WARM FRONT ACROSS WESTERN AND CENTRAL NORTH
DAKOTA TONIGHT...FOLLOWED BY A WEAK DRY COLD FRONT LATE TONIGHT
AND WEDNESDAY. MAIN FORECAST ISSUE TONIGHT WILL BE TEMPERATURES.
THE TEMPERATURE AT WILLISTON DROPPED 10 DEGREES BETWEEN 5 AND 6 PM
CST. COULD SEE A FEW OTHER LOCALES DROP QUICKLY THIS EVENING...BUT
IN GENERAL...MILD SOUTHWEST FLOW WILL KEEP TEMPERATURES MUCH
WARMER TONIGHT WITH MID 20S TO MID 30S READINGS INSTEAD OF SINGLE
DIGITS AND LOW TEENS. MID AND HIGH LEVEL CLOUDINESS WILL ALSO
INCREASE FROM WEST TO EAST LATER THIS EVENING AND OVERNIGHT. NO
SIGNIFICANT CHANGES TO THE GOING FORECAST WERE WARRANTED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
THE MAIN HIGHLIGHTS IN THE SHORT TERM WILL BE A WARM FRONTAL PASSAGE
TONIGHT...MOVING FROM EASTERN MONTANA INTO CENTRAL NORTH DAKOTA.
THIS WILL THEN BE FOLLOWED BY A COLD FRONTAL PASSAGE WEDNESDAY
MORNING. DRY WEATHER WILL ACCOMPANY BOTH FRONTS. LOW LEVEL WARM AIR
ADVECTION CONTINUES OVERNIGHT INTO WEDNESDAY MORNING. WESTERLY WINDS
DEVELOPING IN THE WAKE OF THE COLD FRONTAL PASSAGE WEDNESDAY WILL
HELP MIX DOWN WARMER TEMPS ALOFT BEFORE THE COLD AIR ADVECTION
COMPLETELY ERODES THE WARM LAYER BY 00Z THURSDAY. HIGH TEMPERATURES
WEDNESDAY WILL REACH INTO THE MID AND UPPER 40S NORTH CENTRAL INTO
EAST CENTRAL...TO AROUND 50 DEGREES SOUTH CENTRAL...AND LOWER 50S
SOUTHWEST AND FAR SOUTH.
ANOTHER CONCERN IS THE POTENTIAL FOR STRATUS ASSOCIATED WITH THE
WARM AIR ADVECTION...ALONG AND AHEAD OF THE WARM FRONT THIS
EVENING AND INTO TONIGHT. THE NAM/RAP13 925MB RH FIELDS HAVE NOT
BEEN INITIALIZING WELL AT ALL TODAY...AS THEY HAVE BEEN INDICATING
A HIGH AMOUNT OF LOW LEVEL RH THIS AFTERNOON WHERE WE HAVE A CLEAR
SKY...THUS CANNOT USE THIS DATA FOR TONIGHT. THE HRRR REMAINS
CONSISTENT IN DEVELOPING A SWATH OF LESS THAN 500FT CEILINGS
NEAR/OVER THE SNOWCOVER IN SOUTH DAKOTA PER VISIBLE SATELLITE
IMAGERY BY AROUND 00Z WEDNESDAY. THIS SEEMS REASONABLE...BUT THE
RAPID DEVELOPMENT AND EXTENSIVE AREAL EXTENT SEEMS SUSPECT AT THIS
TIME. WILL BRIEF THE INCOMING EVENING SHIFT TO MONITOR THIS. IF
IT DOES MATERIALIZE...THEN BISMARCK TO JAMESTOWN AND ALL AREAS
SOUTH WOULD BE AFFECTED.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE NOV 12 2013
MAIN FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD WILL BE THE
PASSAGE OF TWO FRONTAL SYSTEMS.
THE EXTENDED PERIOD BEGINS WEDNESDAY NIGHT WITH AN EMBEDDED MID
LEVEL WAVE PUSHING EAST-SOUTHEAST ACROSS THE NORTHERN PLAINS
WITHIN A LONG WAVE TROUGH DEVELOPING FROM THE HUDSON BAY THROUGH
OUR LOCAL AREA SOUTHWEST INTO THE CENTRAL ROCKIES. WILL MAINTAIN
THE PERCENT AND COVERAGE OF CHANCES FOR PRECIPITATION WEDNESDAY
NIGHT...AND INTO THE DAYTIME HOURS THURSDAY. BUFFER SOUNDINGS
INDICATE WE WILL EITHER SEE RAIN OR SNOW DEPENDING ON SURFACE
TEMPERATURES...WITH THE CAA ADVERTISED IN THE MID TO UPPER LEVELS
OF THE ATMOSPHERE.
WE DRY OUT THURSDAY NIGHT AS SURFACE HIGH PRESSURE BUILDS INTO THE
DAKOTAS. FLOW ALOFT TRANSITIONS TO MORE ZONAL AS A VERY BROAD
TROUGH DEVELOPS ACROSS ALL OF NORTH AMERICA. STRONG EMBEDDED
ENERGY PUSHING SOUTHEAST ALONG THE CANADIAN PACIFIC COAST WILL
AMPLIFY THE TROUGH OVER THE WESTERN ROCKIES SATURDAY INTO SATURDAY
NIGHT...WITH THE TROUGH THEN DEVELOPING EAST INTO THE GREAT PLAINS
SUNDAY INTO SUNDAY NIGHT. THIS SYSTEM WILL PUSH A STRONG COLD
FRONT ACROSS NORTH DAKOTA SUNDAY...ALONG WITH INCREASING CHANCES
FOR SNOW WITH THE FRONTAL PASSAGE FROM LATE SATURDAY NIGHT THROUGH
SUNDAY NIGHT. AT THIS TIME THE BEST UPPER LEVEL FORCING AND
ATMOSPHERIC MOISTURE LOOK TO TRACK SOUTH AND EAST OF THE NORTH
DAKOTA...SO DO NOT EXPECT MUCH SNOWFALL OVER THE SECOND HALF OF
THE WEEKEND. POSSIBLE WE COULD APPROACH ADVISORY LEVELS OF 3
INCHES...BUT AT THIS TIME AMOUNTS LOOKS TO FALL BELOW THAT MARK.
BEHIND THE COLD FRONT...ARCTIC AIR WILL SURGE SOUTH INTO THE
REGION RESULTING IN BELOW AVERAGE TEMPERATURES SUNDAY INTO EARLY
NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1214 AM CST WED NOV 13 2013
A WARM FRONT FROM KISN THROUGH KPIR WILL CONTINUE TO MOVE EAST
THROUGH THE NIGHT. LOW LEVEL WIND SHEAR IS POSSIBLE FOR MUCH OF
WESTERN AND CENTRAL NORTH DAKOTA TONIGHT WITH STRONG WINDS IN THE
WARM FRONTAL INVERSION. THE LATEST GUIDANCE SUGGESTS NORTH DAKOTA
SHOULD BE STRATUS FREE TONIGHT...HOWEVER...WILL CONTINUE TO
MONITOR AS A SIMILIAR ENVIRONMENT RESULTED IN STRATUS ACROSS
WYOMING AND SOUTH DAKOTA LAST NIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
405 AM EST WED NOV 13 2013
.SYNOPSIS...
UPSLOPE FLOW SNOW SHOWERS DIMINISH BY MID MORNING. STRONG HIGH
PRESSURE BUILDS IN TODAY AND DOMINATES INTO FRIDAY. WARMING TREND
THURSDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LIGHT SNOW SHOWERS CONTINUE FROM SUMMERSVILLE NORTHEAST THROUGH
ELKINS IN TO THE DELMARVA PENINSULA AND WILL GRADUALLY TAPER OFF
THROUGH THE MID MORNING...INCREASED POPS SLIGHTLY AND EXTENDED TO
15Z IN THE NORTHEAST ZONES TO REFLECT THIS CHANGE...OTHERWISE
TRANSIENT HIGH PRESSURE MOVING IN AS EXPECTED BRINGING DRY COOL AIR
ON THE FRONT SIDE RESULTING IN ONE MORE COLD NIGHT WED INTO THURSDAY
WITH OVERNIGHT LOWS IN THE MID 20`S...500MB HEIGHT RISES AND
SOUTHWEST SURFACE FLOW ON THE BACKSIDE OF THE TRANSIENT SURFACE HIGH
THURSDAY AM WILL BEGIN A WELCOMED WARMING TREND.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
HIGH PRESSURE OVER THE AREA THU MOVES OFF THE E COAST ON FRI...BUT
NOT THAT FAR. THIS SPELLS DRY FCST. WHILE THE HIGH ALSO KEEPS IT
RATHER CLOUD FREE THU AND THU NT...LOW LEVEL RETURN FLOW AROUND THE
BACK SIDE OF THE SLOWLY EXITING HIGH WILL INTRODUCE SOME STRATOCU
FRI AFTERNOON AND NIGHT. A S/W TROUGH IN THE SW FLOW ALOFT WILL
ALSO BRING SOME HIGH AND PERHAPS MID LEVEL CLOUD ACROSS THE AREA ON
FRI.
DIURNAL RANGES WILL BE CONSTRAINED BY LOW SUN ANGLE THIS TIME OF
YEAR...STABLE ATMOSPHERE AMID HIGH PRESSURE...AND NOCTURNAL BOUNDARY
LAYER FLOW WITH THE HIGH NOT RIGHT OVER THE AREA. DAYTIME HIGHS
WERE CLOSE TO THE ALLBLEND WHICH IS ON THE LOW END OF MOS GUIDANCE
ON ACCOUNT OF THE RAW MODEL INFLUENCE SO NO CHANGE NEEDED THERE.
LOWS WERE CLOSER TO THE HIGHER SIDE OF GUIDANCE AND THIS IDEA WAS
MAINTAINED ON ACCOUNT OF THE BOUNDARY LAYER FLOW. COULD SEE LOWS
FRI NT ENDING UP EVEN HIGHER GIVEN THE INTRODUCTION OF CLOUDS AND
LOW LEVEL WARM AIR ADVECTION.
LOWERED RH VALUES A BIT VIA LATEST MOS WITH LARGE DRY AIR MASS IN
CONTROL. THIS DROPS RH VALUES INTO THE 20S THU AND FRI AFTERNOONS.
FUELS ARE OF COURSE RATHER WET ON ACCOUNT OF THE SNOW...BUT BY FRI
THEY MAY BEGIN TO DRY AND AFTERNOON TEMPERATURES WILL BE HIGHER SO
WE WILL AGAIN HAVE TO KEEP AN EYE ON FIRE WX...A BUILDING
CONSEQUENCE OF THE DRY AUTUMN OF 2013.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
DECENT AGREEMENT IN THE EXTENDED AMONGST THE MODELS WHICH FEATURES
UPR RIDGING BUILDING ACROSS SE STATES OVER THE WEEKEND WITH ANOTHER
DEEP AMPLIFICATION OF UPR TROF MOVING INTO REGION EARLY NEXT WEEK.
TRIED TO KEEP MOST DRY FOR SATURDAY GIVEN GOOD DOWNSLOPING FLOW.
SUNDAY...THINGS BECOME A LITTLE MURKIER WITH A PIECE OF ENERGY IN
INCREASINGLY DIFFLUENT FLOW. FEEL BEST CHC FOR SHRA WILL BE ALONG
AND ESPECIALLY W OF OH RVR ON SUNDAY. THUS HAVE HIGH CHC ACROSS SE
OH FOR SAID TIME WITH LOW CHC ELSEWHERE. SFC LOW TRACK THRU W LAKES
HEADING INTO MONDAY AS UPR TROF SHARPENS. THIS WILL ALLOW FOR A
STRONG COLD FRONT TO MOVE THRU MONDAY NIGHT OR EARLY TUES WITH
INCREASING CHC FOR SHRA MONDAY AND MONDAY NIGHT. BUMPED UP POPS INTO
LKLY TO FOLLOW THIS FEATURE. STRONG CAA COMMENCES LATER ON TUE WITH
ANY LINGERING SHRA CHANGING TO SHSN ACROSS THE MTNS AND PERHAPS ADJ
LOWLAND AREAS BEFORE ATMOS COLUMN DRIES OUT TUE NIGHT. SFC HIGH
BUILDS IN FOR WED AS UPR TROF LIFTS OUT.
FOR TEMPS...GENERALLY FOLLOWED HPC WITH SOME INCORPORATION OF GFS
NUMBERS TO HIT WAA NIGHTTIME HRS AND POST FRONTAL CAA BETTER.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
MAIN ISSUE FOR THE LATE NIGHT AND EARLY MORNING HOURS IS THE
EXTENT AND HEIGHT OF THE CEILINGS. RAP INDICATING THE CEILINGS
COULD REFORM AND EVEN LOWER DURING THE PREDAWN.
DID HOLD ONTO SOME 2 TO 3 THSD FT CEILINGS IN THE MOUNTAIN
COUNTIES...WITH MAINLY SCATTERED CLOUDS FURTHER WEST TOWARD THE OHIO
RIVER VALLEY.
SOME 5 TO 6 MILES IN HAZE COULD FORM FOR THE 08Z TO 13Z TIME
FRAME...MAINLY NEAR URBAN AREAS.
ANY LINGERING STRATOCUMULUS SHOULD BE DISSIPATING 18Z WEDNESDAY TO
00Z AS MIXING OCCURS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: EXTENT OF CEILINGS DURING THE 06Z TO 14Z
WEDNESDAY TIME FRAME IS IN QUESTION. COULD BE MORE OR LESS THAN
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.
DATE WED 11/13/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H M M M M M M M H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M H M M M M H H
EKN CONSISTENCY L L L L L L L L H M M M
PKB CONSISTENCY H H H M M M M M H H H H
CKB CONSISTENCY M M M M M M M M M M M H
AFTER 06Z THURSDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/JM
NEAR TERM...JM
SHORT TERM...TRM
LONG TERM...50
AVIATION...KTB/JM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
102 AM EST WED NOV 13 2013
.SYNOPSIS...
LINGERING SNOW SHOWERS TONIGHT IN LOW LEVEL THERMAL TROF.
STRONG HIGH PRESSURE BUILDS IN AND DOMINATES FOR WEDNESDAY INTO
THURSDAY. WARMING TREND LATE WEEK THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
NO SIGNIFICANT CHANGES...A LOCAL COATING OF SNOW STILL POSSIBLE UNDER
ANY LINGERING SNOW SHOWERS...WHICH ARE MAINLY STRETCHED ACROSS
MOUNTAINOUS COUNTIES AND WILL GRADUALLY TAPER OFF BY
SUNRISE...OTHERWISE A CLEAR AND COLD NIGHT WITH TEMPS DROPPING TO
THE UPPER TEENS/LOW 20`S...WILL MONITOR MORNING CLOUD COVER PER
PREVIOUS DISCUSSION BASED ON FORECAST SOUNDINGS HINTING AT PREDAWN
DEVELOPMENT.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
QUIET PERIOD WITH ONLY MINOR TEMPERATURE ADJUSTMENTS MADE TO ONGOING
FORECAST PER LATEST GUIDANCE.
SHOULD BE AN ESSENTIALLY CLEAR SKY WEDNESDAY NIGHT WITH SFC HIGH
PRESSURE LOCATED TO OUR S/SW. OVERNIGHT MINS A BIT TRICKY WITH
COMPETING FORCES AT WORK. CLEAR SKIES...LOW DEWPOINTS...AND MAX
TEMPS WEDNESDAY ONLY IN THE MID/UPPER 30S LOWLANDS WOULD SUGGEST
MINS CLOSER TO COOLER GUIDANCE SUITE. A FAIRLY DECENT BOUNDARY LAYER
WIND HOWEVER ALONG WITH WARM ADVECTION AT 850MB SHOULD LIMIT MAX
COOLING POTENTIAL HOWEVER. SO QUESTION BECOMES EACH SITE/S ABILITY
TO DECOUPLE. IN THE END...DECIDED TO KEEP INHERITED MINS ACROSS
ROUGHLY THE WESTERN THIRD OF THE AREA AND LOWER MINS JUST SLIGHTLY
ACROSS THE CENTRAL AND EASTERN PARTS OF THE AREA WITH LATEST
GUIDANCE...YET STILL REMAINED ON THE WARM SIDE OF GUIDANCE ON THE
WHOLE AS WAS THE TREND WITH PREV FORECAST. EXPECT THE RIDGE TOPS AS
WELL AS THE EASTERN MOUNTAINS TO SEE A `WARMER` NIGHT WITH
AFOREMENTIONED WARM ADVECTION AT 850MB.
AREA REMAINS UNDER W/SW FLOW ALOFT WITH CONTINUED S/SW SFC WINDS AS
SFC HIGH PRESSURE MOVES OFF THE SE ATLANTIC COASTLINE. SKIES WILL
REMAIN MOSTLY SUNNY WITH MAX TEMPS REBOUNDING NICELY INTO THE UPPER
40S NORTHERN LOWLANDS AND LOWER 50S SOUTHERN LOWLANDS. WILL BE A BIT
ON THE BREEZY SIDE...MAINLY ACROSS THE NORTHERN ZONES AND EASTERN
HIGH TERRAIN. COULD BE A BIT OF ENHANCED FIRE DANGER CONCERN AS WELL
WITH LOW RH/S. ACROSS THE LOWLANDS...LOOKS LIKE THE LOWEST RH/S
DON/T OVERLAP WELL WITH THE STRONGER WINDS SO THREAT APPEARS MINIMAL
HERE. SOME VERY DRY AIR ALOFT HOWEVER MAY ALSO RESULT IN RH VALUES
DOWN AROUND THE 25-30 PERCENT RANGE OVER THE HIGH ELEVATIONS WHERE
AFOREMENTIONED GUSTS AROUND 20-25KTS ARE POSSIBLE. YET...RECENT SNOW
MAY TAPER THIS THREAT AS WELL.
THURSDAY NIGHT SHOULD BE A BIT WARMER WITH SOME INCREASE IN HIGH
LEVEL CLOUDS. VERY LITTLE CHANGE HERE WITH INHERITED MINS GENERALLY
IN THE LOWER 30S LOWLANDS. AS WITH PREVIOUS NIGHT...EXPECT A FAIRLY
GOOD TEMP GRADIENT BTWN THE HIGH PEAKS AND SHELTERED VALLEYS OF THE
EASTERN MOUNTAINS.
ANOTHER NICE DAY IN STORE FOR FRIDAY...WITH A CONTINUED WARMUP AS
WELL WITH ONLY AN INCREASE IN MAINLY HIGH CLOUDS EXPECTED. NUDGED
MAX TEMPS UP JUST SLIGHTLY PER LATEST 850MB/925MB TEMPS YET REMAINED
ON THE COOLER SIDE OF GUIDANCE. EXPECT MAX TEMPS FRIDAY INTO THE
MID/UPPER 50S FOR THE LOWLANDS...AND 40S FOR THE EASTERN MOUNTAINS.
RH VALUES ARE NOT EXPECTED TO BE QUITE AS LOW AS THURSDAY/S...NOR
WILL WIND GUST SPEEDS...SO NO FIRE WEATHER CONCERNS ARE ANTICIPATED
ON FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
DECENT AGREEMENT IN THE EXTENDED AMONGST THE MODELS WHICH FEATURES
UPR RIDGING BUILDING ACROSS SE STATES OVER THE WEEKEND WITH ANOTHER
DEEP AMPLIFICATION OF UPR TROF MOVING INTO REGION EARLY NEXT WEEK.
TRIED TO KEEP MOST DRY FOR SATURDAY GIVEN GOOD DOWNSLOPING FLOW.
SUNDAY...THINGS BECOME A LITTLE MURKIER WITH A PIECE OF ENERGY IN
INCREASINGLY DIFFLUENT FLOW. FEEL BEST CHC FOR SHRA WILL BE ALONG
AND ESPECIALLY W OF OH RVR ON SUNDAY. THUS HAVE HIGH CHC ACROSS SE
OH FOR SAID TIME WITH LOW CHC ELSEWHERE. SFC LOW TRACK THRU W LAKES
HEADING INTO MONDAY AS UPR TROF SHARPENS. THIS WILL ALLOW FOR A
STRONG COLD FRONT TO MOVE THRU MONDAY NIGHT OR EARLY TUES WITH
INCREASING CHC FOR SHRA MONDAY AND MONDAY NIGHT. BUMPED UP POPS INTO
LKLY TO FOLLOW THIS FEATURE. STRONG CAA COMMENCES LATER ON TUE WITH
ANY LINGERING SHRA CHANGING TO SHSN ACROSS THE MTNS AND PERHAPS ADJ
LOWLAND AREAS BEFORE ATMOS COLUMN DRIES OUT TUE NIGHT. SFC HIGH
BUILDS IN FOR WED AS UPR TROF LIFTS OUT.
FOR TEMPS...GENERALLY FOLLOWED HPC WITH SOME INCORPORATION OF GFS
NUMBERS TO HIT WAA NIGHTTIME HRS AND POST FRONTAL CAA BETTER.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MAIN ISSUE FOR THE LATE NIGHT AND EARLY MORNING HOURS IS THE
EXTENT AND HEIGHT OF THE CEILINGS. RAP INDICATING THE CEILINGS
COULD REFORM AND EVEN LOWER DURING THE PREDAWN.
DID HOLD ONTO SOME 2 TO 3 THSD FT CEILINGS IN THE MOUNTAIN
COUNTIES...WITH MAINLY SCATTERED CLOUDS FURTHER WEST TOWARD THE OHIO
RIVER VALLEY.
SOME 5 TO 6 MILES IN HAZE COULD FORM FOR THE 08Z TO 13Z TIME
FRAME...MAINLY NEAR URBAN AREAS.
ANY LINGERING STRATOCUMULUS SHOULD BE DISSIPATING 18Z WEDNESDAY TO
00Z AS MIXING OCCURS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: EXTENT OF CEILINGS DURING THE 06Z TO 14Z
WEDNESDAY TIME FRAME IS IN QUESTION. COULD BE MORE OR LESS THAN
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.
DATE WED 11/13/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H H H M M M M M M M H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H M H M H M M M M H H
EKN CONSISTENCY L L L L L L L L H M M M
PKB CONSISTENCY H H H M M M M M H H H H
CKB CONSISTENCY M M M M M M M M M M M H
AFTER 06Z THURSDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/ARJ
NEAR TERM...KTB/JM
SHORT TERM...TRM
LONG TERM...50
AVIATION...KTB/JM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1049 PM CST TUE NOV 12 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 924 PM CST TUE NOV 12 2013
HAVE UPGRADED THE SMALL CRAFT ADVISORY TO A GALE WARNING ON THE
BAY AND NORTHERN LAKE. ALTHOUGH WAA WILL RESULT IN MORE STABLE
CONDITIONS AND SHALLOW MIXING ON WEDNESDAY...BUFKIT SHOWS 950 MB
WINDS INCREASING TO 35-45 KTS...SO SOME GALE FORCE GUSTS LOOK LIKE
A GOOD BET. THE WINDS AND GUSTS SHOULD BE STRONGEST ON THE BAY AND
NORTHERN LAKE...WHERE THE FETCH IS LONGER FOR A SW WIND. COASTAL
CONVERGENCE SHOULD ALSO PLAY A FACTOR ALONG THE WESTERN SHORE OF
DOOR COUNTY. THE MIDNIGHT CREW CAN DECIDE IF THE REST OF THE LAKE
MICHIGAN ZONES (FROM SUE-SBM) NEED TO BE UPGRADED AT 4 AM.
&&
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A 1046MB
HIGH PRESSURE SYSTEM SLIDING SOUTHEAST ACROSS THE CENTRAL PLAINS
EARLY THIS AFTERNOON. LOW CLOUDS AND FLURRIES HAVE RETREATED
NORTHEAST OVER THE CENTRAL UPPER PENINSULA...AND THE ONLY CLOUD
COVER LEFT IS AN AREA OF THIN MID-LEVEL AND HIGH CLOUDS. LOOKING
UPSTREAM...PLENTY OF MOSTLY CLEAR CONDITIONS OVER THE NORTHERN
PLAINS...AND 12Z RAOBS SHOWS A VERY DRY AIRMASS IN PLACE THROUGH
THE COLUMN. SO AS THE SURFACE HIGH MOVES AWAY FROM THE REGION AND
THE PRESSURE GRADIENT TIGHTENS...TEMPS AND WIND GUSTS ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...ARCTIC HIGH PRESSURE WILL SHIFT SOUTH FROM THE CENTRAL TO
SOUTHERN PLAINS. WEST WINDS WILL BACK AROUND TO THE SOUTHWEST AS
THIS OCCURS...AND REMAIN BREEZY THROUGH THE NIGHT. DESPITE MID AND
HIGH CLOUDS STAYING RATHER THIN AND SCATTERED IN NATURE...TEMPS
SHOULD NOT FALL MUCH DUE TO THIS SOUTHWEST BREEZE. UPSTREAM TEMPS
OVER NORTH DAKOTA FELL INTO THE LOWER TEENS TO LOWER 20S...SO WILL
KEEP TEMPS IN THAT RANGE.
WEDNESDAY...SHORTWAVE ENERGY WILL PUSH LOW PRESSURE ACROSS NORTHERN
ONTARIO WHILE THE ARCTIC HIGH WILL STILL BE LINGERING ACROSS THE
SOUTHERN MISSISSIPPI VALLEY. BETWEEN THESE TWO SYSTEMS...THE LOW
LEVEL PRESSURE GRADIENT WILL BE TIGHTENING AND WARM ADVECTING FROM
THE WEST. A STRONG INVERSION WILL DEVELOP...WHICH WILL PREVENT THE
WARMER AIR ALOFT FROM REACHING THE SURFACE. AS A RESULT...TEMPS
WILL NOT REACH THEIR POTENTIAL FROM MIXING...AND REMAIN IN THE UPPER
30S TO LOWER 40S DESPITE AMPLE SUNSHINE. SHOULD SEE SOME WIND GUSTS
APPROACHING 30 MPH THOUGH...LOCALLY STRONGER ON THE BAY SIDE OF THE
DOOR PENINSULA WHERE COASTAL CONVERGENCE WILL OCCUR. WINDS COULD
REACH UP TO 35-40 MPH THERE...WHICH BRINGS THE POSSIBILITY OF GALES
INTO THE PICTURE. HAVE HAD A FEW POTENTIAL GALES WITH WARM
ADVECTION ALREADY THIS FALL AND THEY SEEMED TO UNDER PERFORM WHAT
MODEL GUIDANCE INDICATED. WOULDNT BE SURPRISED IF THAT OCCURRED
AGAIN...BUT THE NAM/GFS/SREF INDICATE MINOR MIXING UP TO 950MB WHICH
WOULD BE ENOUGH TO GENERATE GALE FORCE GUSTS LATE WEDNESDAY
AFTERNOON. AFTER COORDINATION...HAVE DECIDED TO GO WITH A HIGH END
SMALL CRAFT ADVISORY...AND MENTION THE POSSIBILITY OF GALES OVER THE
MIDDLE BAY AND NEARSHORE WATERS ADJACENT TO THE DOOR PENINSULA.
LATER SHIFTS CAN TAKE ANOTHER LOOK AND UPGRADE IF NECESSARY.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 259 PM CST TUE NOV 12 2013
MILDER WEATHER IS EXPECTED THROUGH THE END OF THE WEEK AS UPPER
FLOW FIRST BECOMES ZONAL AND THEN SOUTHWEST. A WEAK SHORTWAVE
TROUGH AND ASSOCIATED WEAK SURFACE FRONT WILL MOVE THROUGH
THURSDAY AND THURSDAY NIGHT. DRY AIR WILL PROBABLY LIMIT
PRECIPITATION TO JUST SCATTERED LIGHT RAIN OR SNOW.
THE ECMWF HAS ABANDONED THE IDEA OF A BIG SNOWSTORM EARLY NEXT
WEEK THAT IT/S 12Z RUN YESTERDAY SUGGESTED. IT IS NOW MORE LIKE THE GFS
IN BRING A WEAKER SURFACE LOW FROM SOUTHERN COLORADO TO THE WESTERN
GREAT LAKES WITH RAIN FOR AT LEAST PART OF THE WEEKEND. THERE IS
STILL A DECENT AMOUNT OF DISAGREEMENT AS FAR AS TIMING AND AMOUNTS
THOUGH PRECIPITATION TYPE LOOKS TO BE MAINLY RAIN.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1048 PM CST TUE NOV 12 2013
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD...WITH ONLY
MID/HIGH CLOUDS AFFECTING THE REGION TONIGHT AND EARLY WEDNESDAY.
THE MAIN AVIATION CONCERN IS LLWS...WHICH WILL DEVELOP LATE TONIGHT
AND CONTINUE THROUGH WEDNESDAY EVENING. WEST-SOUTHWEST WINDS OF
45-50 KTS WILL DEVELOP WITHIN 1-2K FEET AGL. DURING THE LATE
MORNING AND AFTERNOON...SFC WINDS WILL GUST TO 20-30 KTS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
547 AM CST WED NOV 13 2013
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
SURFACE HIGH CURRENTLY OVER SOUTH CENTRAL MISSOURI WILL CONTINUE TO
SHIFT OFF TO THE SOUTHEAST TODAY. ALOFT THE FLOW WILL BECOME
WESTERLY ACROSS THE REGION AS THE RIDGE AXIS SHIFTS EAST AND A
SHORTWAVE DEEPENS OVER THE INTERMOUNTAIN WEST AND HIGH PLAINS. THE
SHORTWAVE WILL BUCKLE THE UPPER FLOW PUTTING IOWA IN A ZONAL FLOW.
THE COMBINATION OF RETURN FLOW AT THE SURFACE AND A ZONAL FLOW ALOFT
MEANS WARMING TEMPS FOR CENTRAL IOWA. THE CAVEATS TO THIS IS THAT
THE NAM MODEL HAS A RIDICULOUS AND ERRONEOUS CALCULATION OF NEARLY
TWO INCHES OF SNOW DEPTH OVER CENTRAL IOWA THUS KEEPING TEMPS WAY
TOO COOL AND MESSING WITH WIND FIELDS AS WELL.
THE RAP AND GFS HAVE A BETTER HANDLE ON SNOW FIELDS. SOUNDINGS ARE
DRY SO IT SHOULD BE A SUNNY DAY TODAY. THERE IS A STRONG NOSE OF
WARM AIR ALOFT AND AN EQUALLY STRONG INVERSION SO WE WILL NOT
REALIZE THE AMOUNT OF WARMTH WE COULD HAVE BUT EVEN IF WE ONLY MIX
TO 925 MB WE WILL TAP SOME OF THE WARMER AIR. NEXT IS SNOW ON THE
GROUND. SATELLITE PIX STILL SHOW A SWATH OF SNOW ACROSS NORTHERN
IOWA FROM ALGONA TO JUST NORTH OF WATERLOO AND NORTH OF THAT LINE.
ANOTHER STRIPE OF SNOW FROM AUDUBON TO KNOXVILLE TO OTTUMWA WAS
EVIDENT SO WHILE THIS WILL NOT BE A SHOW STOPPER FOR A WARM
UP...HIGHS IN THOSE LOCATIONS WILL LIKELY BE A DEGREE OR TWO COLDER
THAN SURROUNDING AREAS. I HAVE ADJUSTED HIGHS ACCORDINGLY IN THOSE
LOCATIONS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
ALTHOUGH THERE IS STILL A TOKEN WINDOW FOR PRECIP THU...THE PRIMARY
CONCERN THROUGH THE PERIOD REMAINS OVER THE WEEKEND AND INTO
EARLY NEXT WEEK. SKIES WILL REMAIN MOSTLY CLEAR INTO TONIGHT WITH
TEMPERATURES MODERATING BACK TO SEASONAL LEVELS. ATTENTION TURNS
TO CURRENT WA/BC SHORT WAVE WHICH SHOULD REACH THE MO VALLEY EARLY
THU. SOMEWHAT DEEP WEAK AND BRIEFLY MODERATE FORCING MOVES
THROUGH THU BUT MOISTURE IS QUITE LIMITED. THE ONLY POTENTIAL FOR
SATURATION IS ABOVE 3KM AND EVEN THAT IS SUSPECT. EXAMINATION OF
295-305K ISENT LAYERS SHOW JUST A NARROW RIBBON OF MOISTURE AND
MOISTURE TRANSPORT WHICH WILL LIKELY GENERATE AT LEAST SOME VIRGA.
PLENTY OF DRY AIR UNDERNEATH WILL DIMINISH MEASURABLE POTENTIAL
HOWEVER SO HAVE OPTED FOR A PERIOD OF SPRINKLES WORDING...MAINLY
NE.
AFTER A BRIEF BREAK INTO FRIDAY PATTERN SHIFT WILL DEVELOP WITH
PRONOUNCED WRN CONUS TROUGH...INITIALLY HELPED BY CURRENT GULF OF AK
SHORT WAVE. THIS WAVE WILL REACH THE FOUR CORNERS AREA BY LATE FRI
AND EVENTUALLY IA SAT. THIS WILL INTRODUCE POPS AS EARLY AS AFTER
MIDNIGHT SATURDAY WITH KINEMATIC FORCING AND A RATHER STRONG SURGE
OF THERMODYNAMIC FORCING/THETA-E ADVECTION. ALTHOUGH NOT INCLUDED
AS OF YET...WOULD NOT BE SURPRISED TO SEE SOME RUMBLES OF THUNDER
AS K INDICES ELEVATE AND MUCAPES REACH A FEW HUNDRED.
LONG WAVE TROUGH THEN ADVANCES INTO THE CENTRAL CONUS AND
SIGNIFICANT QUESTIONS STILL REMAIN. THE GENERAL PROGRESSION
REMAINS SOMEWHAT SIMILAR FROM ECMWF...GFS TO GEM WITH SURFACE LOW
BRUSHING SE IA FOLLOWED BY STRONG COLD ADVECTION AND WINDY
CONDITIONS. TIMING IS STILL SUSPECT HOWEVER AS RUN TO RUN CHANGES
CONTINUE TO BE FASTER WITH NO APPARENT TIMING CONSENSUS DEVELOPING
AS OF YET. PRECIP TYPE IS OBVIOUSLY A BIG CONCERN AND THESE TIMING
DIFFERENCES RESULT IN DIFFERENT SCENARIOS BUT THE MAIN TREND IS
TOWARD MORE RAIN THAN SNOW. GFS FORCING SURGE COINCIDES WITH
SOMEWHAT WARMER TEMPS AND MORE RAIN...WHILE SLOWER ECMWF WOULD
SUGGEST ONLY POTENTIAL FOR SNOW ACROSS NW HALF OF FORECAST AREA ON
THE TRAILING END OF DEFORMATION ZONE. MUCH LIKE YESTERDAY THIS LOW
CONFIDENCE HAS RESULTED IN A TIME LAGGED MODEL CONSENSUS...A BLEND
OF CURRENT AND PREVIOUS RUN TO REDUCE FORECAST CHANGES. THIS
SENSIBLE WEATHER RESULT HAS RAIN SUNDAY AND SUNDAY EVENING...WITH
A BRIEF TRANSITION TO SNOW EARLY MON. LOW END POPS STILL LINGER
INTO THE DAY MON...BUT CONSIDERING FASTER TIMING TRENDS THESE MAY
NEED TO BE REDUCED OR ELIMINATED LATER TODAY.
A FEW THINGS TO MENTION REGARDING TEMPS. 00Z NAM SNOW DEPTH
INITIALIZATION WAS HORRIBLE AS IT CURRENTLY DEPICTS 1-2 INCHES FROM
I80 TO MN BORDER AND ONLY DROPS IT TO AROUND A HALF INCH BY THU.
DOES NOT REALLY GET RID OF IT UNTIL FRI NIGHT. LAST FEW VISIBLE
SATELLITE IMAGES SHOW LINGERING NARROW BAND OF SNOW N OF
ADAIR-INDIANOLA-FAIRFIELD NEARLY GONE...AND ONLY NRN IA SNOW ALONG
AND NORTH OF SPIRIT LAKE-WAVERLY LINE. FEEL THESE EFFECTS SHOULD BE
MINIMIZED BY THU AND ARE NOT INCLUDED IN TEMPS THIS PERIOD. MARKED
DIFFERENCE IN AIRMASS WILL BE NOTED BY THE WEEKEND WITH HIGHS BACK
INTO THE 50S MOST AREAS AND DEWPOINTS WELL INTO THE 40S AND ABOVE
50 CENTRAL AND SE. MON LOOKS SHARPLY COLDER WITH 20F PLUS TEMP
DROP AND BRISK NW WINDS. TEMPS WILL BE BACK TO RECENT COOL LEVELS
BY MON NIGHT.
&&
.AVIATION...13/12Z
ISSUED AT 547 AM CST WED NOV 13 2013
HIGH PRESSURE WILL CONTINUE TO SHIFT SOUTHEAST THROUGH THE FORECAST
PERIOD. WINDS WILL INCREASE TODAY AS A PUSH OF WARMER AIR MOVES
INTO THE STATE. WIND SPEEDS OF 15G30KT WILL BE COMMON AFT 13/16Z
THROUGH 14/00Z. AN UPPER LEVEL FEATURE WILL MOVE INTO THE AREA AFT
14/06Z AND INCREASE CLOUDS. LOW LEVEL RH FIELDS INDICATE LOWER
CLOUDS SHOULD AFFECT NORTHERN TAFS AND HAVE PUT A PERIOD OF THAT
INTO THE TAFS MAINLY AFT 08Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...SMALL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS PORTLAND OR
330 AM PST WED NOV 13 2013
.SYNOPSIS...HIGH PRESSURE STARTS TO BUILD OVER THE REGION TONIGHT AND
WEDNESDAY. HOWEVER A SERIES OF WEAK DISTURBANCES THROUGH THE
NORTHWEST FLOW ALOFT MAY CLIP THE REGION WITH A FEW SHOWERS AT TIMES
TONIGHT AND WEDNESDAY MORNING. A STRONGER FRONT MOVES THROUGH ON
FRIDAY NIGHT WITH A BETTER CHANCE FOR RAIN...WITH MOUNTAIN SNOW
SHOWERS INTO SATURDAY. COOL AND DRY OFFSHORE FLOW IS EXPECTED LATE
SUNDAY INTO MONDAY FOLLOWED BY A RETURN TO MILDER AND WET CONDITIONS
BY MID WEEK.
&&
.SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT...
OUR UPPER LEVEL LOW THAT WAS RESPONSIBLE FOR THE WIDESPREAD RAIN
YESTERDAY HAS PUSHED NORTH INTO CENTRAL B.C. AND IS NOW GETTING
SHOVED INLAND AS ANOTHER UPPER LOW TAKES ITS PLACE IN THE GULF
ALASKA. THE FORMER IS DRAGGING A WEAK FRONTAL BOUNDARY THROUGH
WASHINGTON STATE. REMNANTS OF THIS BOUNDARY WILL BRING A SHOWER OR
TWO TO THE NORTHERN TIER TODAY...WITH THE NORTH COAST AND ELEVATED
TERRAIN FAVORED. SURFACE HIGH PRESSURE IS ANCHORED FARTHER SOUTH AND
RESULTING IN A MIX OF FOG AND LOW CLOUDS THROUGH THE VALLEY.
WITH THE FRONT BEING RATHER BENIGN PUSHING QUICKLY TO OUR EAST
TODAY...OUR ONLY REAL NEAR TERM CONCERN IS THE FOG. ONE WOULD EXPECT
THE FOG TO BECOME DENSE WITH HIGH PRESSURE IN PLACE...BUT THE FRONT
MOVING THROUGH IS STIRRING THINGS UP A BIT. IT HAS BECOME DENSE AT
TIMES AND EXPECT WITH SUCH LOW DEWPOINT DEPRESSIONS THIS TREND WILL
CONTINUE. THE HRRR CONTINUES TO SUGGEST SFC VISIBILITY BELOW A HALF
MILE FOR MUCH OF THE VALLEY THIS MORNING...SO THERE WILL LIKELY BE
DENSE FOG IN SPOTS AND/OR WIDELY VARYING VISIBILITIES DURING THE
MORNING COMMUTE...ESPECIALLY FARHTER SOUTH. RELATIVELY LIGHT FLOW
WILL MEAN A SLOW CLEARING TODAY...WITH THE CENTRAL AND SOUTH VALLEY
STRUGGLING TO BREAK OUT AT ALL.
THE UPPER LOW NOW IN THE GULF OF ALASKA SWINGS THROUGH LATER
THURSDAY AFTERNOON AND EVENING FOR SOME SHOWERS. SNOW LEVELS WILL
BE AROUND 3500-4000 FT WITH THIS FIRST WAVE...A BIT OF A WARMUP FOR
THE NEXT FRONT ON FRIDAY...AND WILL BEGIN A PERIOD OF MOUNTAIN SNOW
FOR A FEW DAYS. WE WILL HAVE BRIEF RIDGING ON THURSDAY NIGHT THUS
JUST SOME LINGERING CASCADE SNOW SHOWERS.
A STRONGER SYSTEM CURRENTLY STILL TAKING SHAPE WEST OF ALASKA WILL
DIG SOUTH THROUGH THE REGION ON FRIDAY MAINLY DURING THE AFTERNOON
AND EVENING PERIOD. THIS SYSTEM WILL HAVE A MUCH STRONGER COLD FRONT
WITH IT...BETTER MOISTURE AVAILABILITY...AND IT WILL ALSO PACK QUITE
A BIT OF WIND. SNOW LEVELS WILL DROP TO THEIR LOWEST
LEVELS YET. THIS FRONT WILL HAVE A BIT OF WIND WITH IT AS COLDER AIR
FILTERS SOUTH INTO THE REGION. EXPECT THAT FRIDAY...ESPECIALLY THE
LATTER PORTION WILL BE RATHER WET FOR THE LOWLANDS. SNOW LEVELS START
OFF IN THE AFTERNOON IN THE 3000-3500 FT RANGE...BUT THEN THEY DROP
TO ABOUT 2000 FEET IN THE EVENING AND OVERNIGHT...POSSIBLY GETTING AS
LOW AS 1500 FEET BY EARLY SATURDAY. A STRONG UPPER LEVEL JET WILL
COME DOWN THE OFFSHORE SIDE OF THIS INSIDE SLIDER COUPLED WITH STRONG
925-850 MB FRONTOGENESIS ALONG AND BEHIND THE SURFACE FRONT...MEANING
THE FORCING WILL BE AROUND EVEN ON THE COLD SIDE OF THIS SYSTEM.
COUPLE WITH 850 WINDS IN EXCESS OF 30-35 KT AND 700 MB WINDS UPWARDS
OF 60 KT...AND THIS WILL ALLOW FOR A PERIOD OF MODERATE TO HEAVY SNOW
AND WINDY CONDITIONS IN THE MOUNTAINS FRIDAY LATER AFTERNOON OR
EVENING. BE PREPARED FOR WINTER DRIVING CONDITIONS. KMD
.LONG TERM...SATURDAY THROUGH MID WEEK...BEHIND THE FRONT
FRIDAY...THE REGION REMAINS IN CYCLONIC FLOW ON THE BACK SIDE...AND
MODERATE WESTERLY FLOW WILL CONTINUE THE SHOWERS WITH SNOW LEVELS
HANGING IN THE 2000-2500 FOOT RANGE IN THE CASCADES. HIGH PRESSURE
LOOKS TO BUILD IN FROM SOUTH TO NORTH SUNDAY THOUGH THERE MAY BE SOME
LINGERING MOUNTAIN SNOW SHOWER. COOL AND DRY OFFSHORE FLOW LOOKS TO
SET UP ON MONDAY. LONGER RANGE MODELS WANT TO BRING THE NW INTO MORE
PROGRESSIVE WESTERLY PACIFIC FLOW WHICH TENDS TO MEAN MILD AND
RELATIVELY WET CONDITIONS FOR MID WEEK. KMD
&&
.AVIATION...MVFR CIGS FOR THE COAST WITH PRIMARILY IFR CIGS INLAND
UNDER STRATUS LEFT FROM RESIDUAL LOW LEVEL MOISTURE. A WEAK
PASSING FRONT IS HELPING LIFT THE DECK A BIT WITH SURPRISINGLY GOOD
VISIBILITIES UNDERNEATH. EXPECT THAT BY DAYBREAK THE FRONT WILL
HAVE SUFFICIENTLY PASSED AND THE REGION WILL SEE THE LOW STRATUS
DROP BACK TOWARD THE SURFACE RESULTING IN AREAS OF FOG. LIGHT
NORTHERLY FLOW WILL RETURN TO THE VALLEY AND LIMIT BREAKOUT
POTENTIAL SOUTH OF THE PORTLAND METRO. MAY SEE A FEW HOURS OF
CLEARING AT THE COAST PLUS BETWEEN KUAO AND KSLE BUT FEEL THE
SOUTH VALLEY STANDS LITTLE CHANCE OF BREAKING FREE OF THE CLOUDS
TODAY. KPDX AND KTTD WILL PROBABLY BREAK FREE MID AFTERNOON AND
REMAIN SOMEWHAT FREE OF STRATUS INTO THE EARLY EVENING...BUT ONLY
HAVE MODERATE CONFIDENCE AT BEST.
KPDX AND APPROACHES...MVFR FOR THE NEXT FEW HOURS UNTIL THE WEAK
FRONT PASSES SOMETIME AROUND 14Z. THEN SEEMS MOST LIKELY TO HAVE
THE DECK DROP A FEW HUNDRED FEET AND REACH IFR FOR THE BULK OF THE
MORNING ARRIVALS. MVFR CIGS AROUND 015 FOR THE EARLY AFTERNOON
THEN CLEARING EXPECTED HEADING IN THE EVENING. NOT TERRIBLY CONFIDENT
HOW LONG THE CLEARING WILL LAST TODAY BEFORE A LOW END MVFR DECK
RETURNS OVERNIGHT. /JBONK
&&
.MARINE...FAIRLY TRANQUIL CONDITIONS FOR THE NEXT COUPLE DAYS.
WILL SEE HIGH PRESSURE BRIEFLY DOMINATE TO THE WEST WITH WEAK LOW
PRESSURE AREAS TRANSITING SOUTH OVER THE AREA. HAVE ALREADY TURNED
PRIMARY ATTENTION TO A VIGOROUS SYSTEM APPROACHING FRIDAY.
DEVELOPING LOW PRESSURE WILL SLIDE SOUTH ALONG THE B.C. COAST
BEFORE PUSHING FURTHER INLAND TOWARD NORTHEAST WASHINGTON.WILL SEE
QUITE THE DYNAMIC FETCH SET UP ON THIS TRAJECTORY. SOLID SMALL
CRAFT SW PRE-FRONTAL WINDS WILL CROSS THE WATERS FRIDAY EVENING.
STRONG COLD AIR WILL FUNNEL DOWN THE COAST AND BRING STRONGER NW
WINDS ALOFT TOWARD THE SURFACE. AM HAVING ABOVE AVERAGE CONFIDENCE
IN GALE GUSTS FOR THE REMAINDER OF FRIDAY NIGHT AND MUCH OF
SATURDAY UNDER THIS SCENARIO. FEEL WIND WAVE/FRESH SWELL DOMINATED
SEAS WILL APPROACH AT LEAST 20 FT FOR THE NORTHERN OUTER WATERS
AND EASILY REACH THE UPPER TEENS CLOSER TO SHORE EARLY SATURDAY.
CONDITIONS GRADUALLY EASE SUNDAY WITH HIGH PRESSURE BUILDING OVER
THE REGION FOR EARLY NEXT WEEK. /JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
325 PM MST WED NOV 13 2013
.SHORT TERM...WESTERLY FLOW ALOFT CURRENTLY ACROSS COLORADO WITH
UPPER LEVEL DISTURBANCE MOVING INTO THE NORTHERN GREAT BASIN. MID
AND HIGH LEVEL MOISTURE INCREASING ACROSS THE STATE...WITH NEAREST
PRECIPITATION OVER SOUTHEAST IDAHO AND WESTERN WYOMING. SURFACE
LEE TROUGH ACROSS EASTERN PLAINS WITH GUSTY WINDS IN AND NEAR
FOOTHILLS. MODELS SHOW THE DISTURBANCE MOVING INTO NORTHERN UTAH
AND WESTERN WYOMING THIS EVENING...THEN ACROSS WYOMING AND
NORTHERN COLORADO OVERNIGHT. BEST LIFT AND MID LEVEL ASCENT TO BE
NORTH OF COLORADO. MOISTURE WILL GRADUALLY DEEPEN ACROSS THE
MOUNTAINS...WITH INCREASING MID LEVEL QG ASCENT. SHOULD SEE SOME
SNOW SHOWERS DEVELOP DURING THE EVENING WITH A BETTER CHANCE
OVERNIGHT. THE BEST CHANCE FOR SNOW WILL BE ACROSS THE NORTHERN
MOUNTAINS IN AREA OF BETTER MID LEVEL ASCENT. MAY SEE SOME SNOW
SHOWERS DEVELOP AFTER MIDNIGHT ALONG THE FOOTHILLS AS THE MID
LEVEL ASCENT INCREASES. ACROSS PLAINS...LEE TROUGH WILL WEAKEN
THROUGH THE EVENING WITH DECREASING WESTERLY WINDS ALONG FOOTHILLS.
DISTURBANCE WILL PUSH A COLD FRONT ACROSS THE PLAINS AFTER MIDNIGHT
WITH WEST TO NORTHWEST WINDS BECOMING NORTHERLY. LATEST MODELS...
INCLUDING THE RAP...HAVE BEEN SHOWING A BIT MORE OF A NORTHEAST
COMPONENT BETWEEN 08Z AND 12Z WHEN THE BEST LIFT IS IN PLACE.
MODELS STILL INDICATING A LACK OF LOW LEVEL MOISTURE...THOUGH THE
LATEST RAP HAS SHOWN SOME INCREASE. WILL MAINTAIN THE LOW POPS
ALONG THE NORTHERN BORDER FOR NOW...BUT MAY NEED TO INCLUDE LOW
POPS FURTHER SOUTH TOWARD DENVER. OVERNIGHT TEMPERATURES SUGGEST A
MIX OF RAIN AND SNOW. ON THURSDAY...DISTURBANCE TO MOVE INTO
NEBRASKA DURING THE MORNING WITH SUBSIDENCE AND DECREASING
MOISTURE. FLOW ALOFT BECOMES NORTHWEST WITH IMPROVING
OROGRAPHICS...BUT WITH LESS MOISTURE AND LACK OF ASCENT...ANY
SNOW SHOWERS WILL BE ON THE DECREASE AND WILL KEEP THE SLIGHT
CHANCE OF SHOWERS GOING FOR THE MORNING. ACROSS THE PLAINS...ANY
LINGERING PRECIPITATION SHOULD END QUICKLY DURING THE EARLY
MORNING WITH DECREASING LIFT...MOISTURE AND UPSLOPE. SKIES TO
BECOME PARTLY SUNNY BY THE AFTERNOON. AIRMASS WILL BE COOLER WITH
TEMPERATURES CLOSER TO NORMAL.
.LONG TERM...WEST-NORTHWESTERLY FLOW ALOFT THURSDAY NIGHT BECOMES
WEST-SOUTHWESTERLY BY FRIDAY...THEN A WEAK UPPER TROUGH MOVES
ACROSS FRIDAY NIGHT. ON SATURDAY...STRONG WEST-SOUTHWESTERLY FLOW
ALOFT IS PROGGED WITH AN LARGE UPPER TROUGH TO MOVE INTO COLORADO
SATURDAY NIGHT/SUNDAY MORNING. WEAK SYNOPTIC SCALE UPWARD ENERGY
IS PROGGED FOR THE CWA THURSDAY NIGHT THROUGH FRIDAY EVENING. WEAK
DOWNWARD MOTION FOLLOWS...THEN UPWARD ENERGY MOVES BACK IN BY 18Z
SATURDAY. THE UPWARD MOTION IS FAIRLY STRONG SATURDAY NIGHT. THE
LOW LEVEL PRESSURE AND WINDS FIELDS SHOW TROUGHING EAST OF THE
MOUNTAINS THURSDAY NIGHT AND FRIDAY. SOUTHEASTERLIES TO
SOUTHWESTERLIES DOMINATE. BY LATE FRIDAY NIGHT...DOWNSLOPING
PREVAILS. FOR THE SUBSTANTIAL UPPER TROUGH SATURDAY NIGHT...THE
VARIOUS MODELS SET UP THE SURFACE CYCLONE OVER EAST CENTRAL
COLORADO. THERE IS AN INVERTED TROUGH AND NO REAL UPSLOPE FROM ANY
OF THE MODELS. IN FACT...MOST OF THE MODELS SHOW DECENT DRY
DOWNSLOPING OFF THE MOUNTAINS FOR THE FOOTHILLS AND WESTERN HALF
OF THE PLAINS. NOT GOOD FOR A DECENT SNOWFALL. FOR MOISTURE...
THERE IS NOT MUCH THURSDAY NIGHT INTO FRIDAY AFTERNOON ON ANY OF
THE MODELS...DEFINITELY LESS THAN PREVIOUS RUNS INDICATED.
MOISTURE INCREASES BY FRIDAY AFTERNOON OVER THE MOUNTAINS.
MOISTURE STAYS FAIRLY DEEP OVER THE MOUNTAINS FRIDAY NIGHT THROUGH
SATURDAY NIGHT. MOISTURE OVER THE PLAINS INCREASES OVER THE MID
AND UPPER LEVELS STARTING SATURDAY AFTERNOON. THE LOW LEVEL
MOISTURE OVER THE PLAINS IS POOR THROUGH 12Z SUNDAY MORNING. THE
QPF FIELDS BRING IN A TAD OF MEASURABLE PRECIPITATION TO THE
MOUNTAINS FRIDAY AFTERNOON...CONTINUING THROUGH SATURDAY
AFTERNOON. THERE IS MORE SATURDAY NIGHT...AND ALSO A TINY BIT OUT
ON THE PLAINS SATURDAY NIGHT. THE AMOUNTS OVER THE MOUNTAINS FROM
FRIDAY AFTERNOON THROUGH SUNDAY MORNING ARE NOT SIGNIFICANT.
OROGRAPHIC-WISE...THE MOUNTAIN TOP FLOW IS MAINLY SOUTHWEST FOR
OUR MOUNTAINS. SO WILL GO WITH MAINLY "CHANCES" IN THE HIGH
THERE FROM FRIDAY AFTERNOON THROUGH SUNDAY MORNING 12Z. WILL GO
WITH "SLIGHT CHANCES"S OVER THE PLAINS SATURDAY NIGHT. ALL THE
MODELS SHOW THIS STORM TO HAVE DECREASED IN SIGNIFICANCE...
ALTHOUGH YOU CAN`T DISCOUNT THE UPWARD Q-G VERTICAL VELOCITY. THE
MOISTURE IS POOR OUT ON THE PLAINS. FOR TEMPERATURES...FRIDAY`S
HIGHS ARE A TAD WARMER THAN THURSDAY`S. SATURDAY`S ARE A BIT
COOLER THAN FRIDAY`S...BUT NOT MUCH. THE COLD AIR WITH THE UPPER
TROUGH DOESN`T COME IN UNTIL SUNDAY. FOR THE LATER DAYS...SUNDAY
THROUGH WEDNESDAY...MODELS HAVE THE UPPER TROUGH AXIS EAST OF THE
CWA BY EARLY SUNDAY AFTERNOON. QUITE A CHANGE FROM THREE DAYS
AGO. THE GFS AND ECMWF ARE IN BETTER SYNC WITH THE MAJOR FEATURES
OF THE STORM. THEY BOTH ALSO DRY THINGS OUT SIGNIFICANTLY ON
SUNDAY...SO WILL ADJUST SOMEWHAT IN ENDING THINGS QUICKER. THERE
ARE STILL SEVERAL MORE MODEL RUNS UNTIL WE SEE THE STORM. THE COLD
AIR ON SUNDAY IS NOT SIGNIFICANT EITHER. UPPER RIDGING MOVES IN
MONDAY AND TUESDAY...THEN A WEAK UPPER TROUGH IS NOTED ON
WEDNESDAY.
&&
.AVIATION...VFR TO PREVAIL THROUGH THURSDAY. LIGHT EAST TO
SOUTHEAST WINDS PREVAILING AT KDEN AND KAPA WITH WESTERLY WINDS TO
AROUND 15 KTS AT KBJC. WINDS WILL GRADUALLY DECREASE AT KBJC
DURING THE EVENING THOUGH WILL REMAIN WESTERLY WHILE BECOMING
SOUTHERLY AT KDEN AND KAPA. WINDS TO THEN SHIFT TO THE NORTHWEST
ACROSS THE AREA AIRPORTS AROUND 10Z...THEN NORTHERLY AFTER 12Z AS
A COLD FRONT MOVES ACROSS THE AREA. SPEEDS TO INCREASE TO AROUND
10 KTS. INCREASING MID LEVEL MOISTURE WILL CEILINGS LOWERING TO
AROUND 9000 FEET AGL. AT THIS TIME...ANY CHANCE FOR SHOWERS WILL
BE ALONG THE NORTHERN COLORADO BORDER AND ACROSS THE FOOTHILLS.
CLOUDS TO DECREASE AFTER 16Z WITH DECREASING WINDS...BECOMING
EASTERLY DURING THE AFTERNOON.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RJK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1126 AM CST WED NOV 13 2013
.SHORT TERM /TODAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
SURFACE HIGH CURRENTLY OVER SOUTH CENTRAL MISSOURI WILL CONTINUE TO
SHIFT OFF TO THE SOUTHEAST TODAY. ALOFT THE FLOW WILL BECOME
WESTERLY ACROSS THE REGION AS THE RIDGE AXIS SHIFTS EAST AND A
SHORTWAVE DEEPENS OVER THE INTERMOUNTAIN WEST AND HIGH PLAINS. THE
SHORTWAVE WILL BUCKLE THE UPPER FLOW PUTTING IOWA IN A ZONAL FLOW.
THE COMBINATION OF RETURN FLOW AT THE SURFACE AND A ZONAL FLOW ALOFT
MEANS WARMING TEMPS FOR CENTRAL IOWA. THE CAVEATS TO THIS IS THAT
THE NAM MODEL HAS A RIDICULOUS AND ERRONEOUS CALCULATION OF NEARLY
TWO INCHES OF SNOW DEPTH OVER CENTRAL IOWA THUS KEEPING TEMPS WAY
TOO COOL AND MESSING WITH WIND FIELDS AS WELL.
THE RAP AND GFS HAVE A BETTER HANDLE ON SNOW FIELDS. SOUNDINGS ARE
DRY SO IT SHOULD BE A SUNNY DAY TODAY. THERE IS A STRONG NOSE OF
WARM AIR ALOFT AND AN EQUALLY STRONG INVERSION SO WE WILL NOT
REALIZE THE AMOUNT OF WARMTH WE COULD HAVE BUT EVEN IF WE ONLY MIX
TO 925 MB WE WILL TAP SOME OF THE WARMER AIR. NEXT IS SNOW ON THE
GROUND. SATELLITE PIX STILL SHOW A SWATH OF SNOW ACROSS NORTHERN
IOWA FROM ALGONA TO JUST NORTH OF WATERLOO AND NORTH OF THAT LINE.
ANOTHER STRIPE OF SNOW FROM AUDUBON TO KNOXVILLE TO OTTUMWA WAS
EVIDENT SO WHILE THIS WILL NOT BE A SHOW STOPPER FOR A WARM
UP...HIGHS IN THOSE LOCATIONS WILL LIKELY BE A DEGREE OR TWO COLDER
THAN SURROUNDING AREAS. I HAVE ADJUSTED HIGHS ACCORDINGLY IN THOSE
LOCATIONS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 332 AM CST WED NOV 13 2013
ALTHOUGH THERE IS STILL A TOKEN WINDOW FOR PRECIP THU...THE PRIMARY
CONCERN THROUGH THE PERIOD REMAINS OVER THE WEEKEND AND INTO
EARLY NEXT WEEK. SKIES WILL REMAIN MOSTLY CLEAR INTO TONIGHT WITH
TEMPERATURES MODERATING BACK TO SEASONAL LEVELS. ATTENTION TURNS
TO CURRENT WA/BC SHORT WAVE WHICH SHOULD REACH THE MO VALLEY EARLY
THU. SOMEWHAT DEEP WEAK AND BRIEFLY MODERATE FORCING MOVES
THROUGH THU BUT MOISTURE IS QUITE LIMITED. THE ONLY POTENTIAL FOR
SATURATION IS ABOVE 3KM AND EVEN THAT IS SUSPECT. EXAMINATION OF
295-305K ISENT LAYERS SHOW JUST A NARROW RIBBON OF MOISTURE AND
MOISTURE TRANSPORT WHICH WILL LIKELY GENERATE AT LEAST SOME VIRGA.
PLENTY OF DRY AIR UNDERNEATH WILL DIMINISH MEASURABLE POTENTIAL
HOWEVER SO HAVE OPTED FOR A PERIOD OF SPRINKLES WORDING...MAINLY
NE.
AFTER A BRIEF BREAK INTO FRIDAY PATTERN SHIFT WILL DEVELOP WITH
PRONOUNCED WRN CONUS TROUGH...INITIALLY HELPED BY CURRENT GULF OF AK
SHORT WAVE. THIS WAVE WILL REACH THE FOUR CORNERS AREA BY LATE FRI
AND EVENTUALLY IA SAT. THIS WILL INTRODUCE POPS AS EARLY AS AFTER
MIDNIGHT SATURDAY WITH KINEMATIC FORCING AND A RATHER STRONG SURGE
OF THERMODYNAMIC FORCING/THETA-E ADVECTION. ALTHOUGH NOT INCLUDED
AS OF YET...WOULD NOT BE SURPRISED TO SEE SOME RUMBLES OF THUNDER
AS K INDICES ELEVATE AND MUCAPES REACH A FEW HUNDRED.
LONG WAVE TROUGH THEN ADVANCES INTO THE CENTRAL CONUS AND
SIGNIFICANT QUESTIONS STILL REMAIN. THE GENERAL PROGRESSION
REMAINS SOMEWHAT SIMILAR FROM ECMWF...GFS TO GEM WITH SURFACE LOW
BRUSHING SE IA FOLLOWED BY STRONG COLD ADVECTION AND WINDY
CONDITIONS. TIMING IS STILL SUSPECT HOWEVER AS RUN TO RUN CHANGES
CONTINUE TO BE FASTER WITH NO APPARENT TIMING CONSENSUS DEVELOPING
AS OF YET. PRECIP TYPE IS OBVIOUSLY A BIG CONCERN AND THESE TIMING
DIFFERENCES RESULT IN DIFFERENT SCENARIOS BUT THE MAIN TREND IS
TOWARD MORE RAIN THAN SNOW. GFS FORCING SURGE COINCIDES WITH
SOMEWHAT WARMER TEMPS AND MORE RAIN...WHILE SLOWER ECMWF WOULD
SUGGEST ONLY POTENTIAL FOR SNOW ACROSS NW HALF OF FORECAST AREA ON
THE TRAILING END OF DEFORMATION ZONE. MUCH LIKE YESTERDAY THIS LOW
CONFIDENCE HAS RESULTED IN A TIME LAGGED MODEL CONSENSUS...A BLEND
OF CURRENT AND PREVIOUS RUN TO REDUCE FORECAST CHANGES. THIS
SENSIBLE WEATHER RESULT HAS RAIN SUNDAY AND SUNDAY EVENING...WITH
A BRIEF TRANSITION TO SNOW EARLY MON. LOW END POPS STILL LINGER
INTO THE DAY MON...BUT CONSIDERING FASTER TIMING TRENDS THESE MAY
NEED TO BE REDUCED OR ELIMINATED LATER TODAY.
A FEW THINGS TO MENTION REGARDING TEMPS. 00Z NAM SNOW DEPTH
INITIALIZATION WAS HORRIBLE AS IT CURRENTLY DEPICTS 1-2 INCHES FROM
I80 TO MN BORDER AND ONLY DROPS IT TO AROUND A HALF INCH BY THU.
DOES NOT REALLY GET RID OF IT UNTIL FRI NIGHT. LAST FEW VISIBLE
SATELLITE IMAGES SHOW LINGERING NARROW BAND OF SNOW N OF
ADAIR-INDIANOLA-FAIRFIELD NEARLY GONE...AND ONLY NRN IA SNOW ALONG
AND NORTH OF SPIRIT LAKE-WAVERLY LINE. FEEL THESE EFFECTS SHOULD BE
MINIMIZED BY THU AND ARE NOT INCLUDED IN TEMPS THIS PERIOD. MARKED
DIFFERENCE IN AIRMASS WILL BE NOTED BY THE WEEKEND WITH HIGHS BACK
INTO THE 50S MOST AREAS AND DEWPOINTS WELL INTO THE 40S AND ABOVE
50 CENTRAL AND SE. MON LOOKS SHARPLY COLDER WITH 20F PLUS TEMP
DROP AND BRISK NW WINDS. TEMPS WILL BE BACK TO RECENT COOL LEVELS
BY MON NIGHT.
&&
.AVIATION...13/18Z
ISSUED AT 1126 AM CST WED NOV 13 2013
VFR CONDITIONS WILL PREVAIL AT LEAST THROUGH TONIGHT WITH CLEAR
SKIES AND SOUTH SOUTHWEST WINDS DIMINISHING WITH SUNSET. ON
THURSDAY MORNING A WEAK SURFACE TROUGH WILL APPROACH FROM THE
NORTHWEST BRINGING SOME CLOUDS TOWARD THE END OF THE TAF
PERIOD...AND POSSIBLY SOME MVFR CIGS AT KFOD/KMCW AFTER 14Z OR
SO.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...FAB
LONG TERM...SMALL
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS TOPEKA KS
500 PM CST Wed Nov 13 2013
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Thursday)
Issued at 249 PM CST WED NOV 13 2013
Little in the way of significant forecast problems for tonight and
Thursday. Sig pressure gradient between high over the southern
Mississippi valley and low pressure developing in the lee of the
Rockies has lead to gusty southerly winds today. These winds
will diminish late afternoon and early evening but maintain about 10
kts overnight...keeping temperatures from falling below the upper
20s to lower 30s.
Water vapor loop overlaid with RAP analysis and national radar show
precipitation associated with low amplitude shortwave trough
crossing the northern Rockies. This trough is forecast by all
models to move east across the northern U.S., approaching the
western Great Lakes by Thursday evening. Greatest forcing aloft and
any chance of measurable precipitation with this system is forecast
to stay well north of Kansas. Trailing surface low pressure trough
along with thicker mid and high level clouds should move into north
central and northeast Kansas Thursday afternoon. Thus...afternoon
winds on Thursday should not be as strong as those occurring today.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 249 PM CST WED NOV 13 2013
Focus of the longer term remains on the evolution of the storm
system into the weekend. Sfc low development will occur Friday
night into Saturday across western KS/NE as the first of two main
waves move through the longwave trough and into the plains. WAA
and lift should aid in the development of showers and perhaps
isolated thunderstorms later Friday night and into Saturday. Low
level winds veer in wake of the initial wave later Saturday
Saturday night so precip chcs appear sct at best during Sat night.
The second and main shortwave will emerge by Sunday along with the
associated sfc low. The low will track into Wisconsin later Sunday
with the cold front forecast to sweep through the area during the day.
The second upper wave remains progressive so don`t expect much in
the way of additional precip Sunday into Sunday night although CAA
along with shallow lift could result in light rain showers/drizzle
or some snow flurries later Sunday night.
All in all the ECMWF has trended less amplified with the pattern
into next week and as a result is not as cold while GFS remains
colder. In any case, it appears colder than avg for early next
week then moderating with dry/quiet weather after Sunday night.
&&
.AVIATION...(For the 00Z TAFs through 00Z Thursday Evening)
Issued at 500 PM CST WED NOV 13 2013
Limited moisture should allow for dry weather with VFR conditions
in spite of a weak upper level wave moving overhead late tonight
and Thursday. A surface trough axis is expected to remain west of
MHK so the forecast does not anticipate a wind shift prior to 00Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Omitt
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
241 PM MST WED NOV 13 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1228 PM MST WED NOV 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE
RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH
ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH
IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN
TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV
IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS
THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE
UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE
SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN
COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY
LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES
REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO.
LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE
BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET.
THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH
THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH
ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN
PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE
BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY
MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE
FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT.
AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO
SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO
UPPER 50S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 136 PM MST WED NOV 13 2013
THE MAIN LONG TERM FORECAST CONCERN IS STILL THE POSSIBILITY OF
PRECIPITATION BETWEEN SATURDAY NIGHT AND SUNDAY NIGHT.
DRY CONDITIONS AND MID TEMPERATURES WITH PERIODIC INCREASES AND
DECREASES IN MOSTLY HIGH CLOUDS ARE EXPECTED FROM THURSDAY NIGHT
THROUGH SATURDAY AS A SERIES OF FRAGMENTED LEE TROUGHS ACCOMPANY A
SERIES OF UPPER SHORT WAVE TROUGHS ACROSS THE CENTRAL HIGH PLAINS
REGION.
BY SATURDAY NIGHT...THE MAIN UPPER TROUGH DIVES FROM THE PACIFIC
NORTHWEST INTO THE INTERMOUNTAIN REGION AND EMERGES EAST OF THE
ROCKIES ACROSS THE NORTHERN AND CENTRAL PLAINS ON SUNDAY. THE MAIN
FRONT MOVES THROUGH THE FORECAST AREA BY LATE SATURDAY WITH THE
COLDER AIR BEHIND THE FRONT TO MOVE INTO THE CENTRAL HIGH PLAINS
REGION SATURDAY NIGHT AND SUNDAY. CURRENTLY EXPECT A RAIN/SNOW MIX
TO MOVE INTO THE FORECAST AREA FROM THE NORTHWEST ON SATURDAY
NIGHT. THIS MIX WILL CHANGE OVER TO LIGHT RAIN DURING THE DAY ON
SUNDAY BEFORE CHANGING OVER TO LIGHT SNOW SUNDAY EVENING AS
PRECIPITATION ALSO BEGINS TO TAPER OFF FROM WEST TO EAST SUNDAY NIGHT.
DRY CONDITIONS ARE EXPECTED DURING THE FIRST PART OF NEXT WEEK
ALONG WITH COOLER THAN AVERAGE TEMPERATURES AS A SURFACE HIGH
PRESSURE AREA MOVES INTO THE PLAINS STATES WITH A RIDGE OF HIGHER
PRESSURE MOVING IN FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1008 AM MST WED NOV 13 2013
VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE
PERIOD. SOUTHERLY WINDS 8-12KT WILL CONTINUE THROUGH THE EARLY TAF
PERIOD AT BOTH TAF SITES WITH SW FLOW AHEAD OF SURFACE TROUGH.
SURFACE TROUGH WILL SHIFT EAST THIS EVENING WITH WINDS BECOMING
VARIABLE AROUND 3-6KT. COLD FRONT WILL DROP SOUTH IN THE 06-09Z
TIME PERIOD WITH WINDS SHIFTING TO THE NORTH-NORTHWEST AND
INCREASING TO 10-14KT RANGE THROUGH THE END OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
315 PM CST Wed Nov 13 2013
.SHORT TERM...(This Evening through Thursday)
Issued at 249 PM CST WED NOV 13 2013
Little in the way of significant forecast problems for tonight and
Thursday. Sig pressure gradient between high over the southern
Mississippi valley and low pressure developing in the lee of the
Rockies has lead to gusty southerly winds today. These winds
will diminish late afternoon and early evening but maintain about 10
kts overnight...keeping temperatures from falling below the upper
20s to lower 30s.
Water vapor loop overlaid with RAP analysis and national radar show
precipitation associated with low amplitude shortwave trough
crossing the northern Rockies. This trough is forecast by all
models to move east across the northern U.S., approaching the
western Great Lakes by Thursday evening. Greatest forcing aloft and
any chance of measurable precipitation with this system is forecast
to stay well north of Kansas. Trailing surface low pressure trough
along with thicker mid and high level clouds should move into north
central and northeast Kansas Thursday afternoon. Thus...afternoon
winds on Thursday should not be as strong as those occurring today.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 249 PM CST WED NOV 13 2013
Focus of the longer term remains on the evolution of the storm
system into the weekend. Sfc low development will occur Friday
night into Saturday across western KS/NE as the first of two main
waves move through the longwave trough and into the plains. WAA
and lift should aid in the development of showers and perhaps
isolated thunderstorms later Friday night and into Saturday. Low
level winds veer in wake of the initial wave later Saturday
Saturday night so precip chcs appear sct at best during Sat night.
The second and main shortwave will emerge by Sunday along with the
associated sfc low. The low will track into Wisconsin later Sunday
with the cold front fcst to sweep through the area during the day.
The second upper wave remains progressive so don`t expect much in
the way of additional precip Sunday into Sunday night although CAA
along with shallow lift could result in light rain showers/drizzle
or some snow flurries later Sunday night.
All in all the ECMWF has trended less amplified with the pattern
into next week and as a result is not as cold while GFS remains
colder. In any case, it appears colder than avg for early next
week then moderating with dry/quiet weather after Sunday night.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Noon)
Issued at 1148 AM CST WED NOV 13 2013
VFR conditions will continue forecast. Southerly winds will gust
to 24 to 28 kts this afternoon and then die down late
afternoon/evening. Some concern about potential for low-level wind
shear tonight as southwest winds of about 45 kts are forecast at
about 2000 ft AGL with southerly surface winds around 10 to 12
kts. Cirrus will increase Thursday morning.
GDP
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GDP
LONG TERM...Omitt
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1228 PM MST WED NOV 13 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1228 PM MST WED NOV 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS SERIES OF SHORTWAVE
RIDGES AND TOUGHS FROM MISSISSIPPI VALLEY TO PACIFIC NORTHWEST WITH
ACTIVE ZONAL PATTERN ACROSS THE CONUS. THERE IS A SHORTWAVE TROUGH
IS PLACE OVER SOUTHERN NEBRASKA EXTENDING SOUTH TO NORTHERN
TEXAS...HOWEVER THERE IS LARGE SCALE DRY AIR MASS EVIDENT ON WV
IMAGERY. A MOIST MID-UPPER LEVEL MOISTURE PLUME IS IN PACE ACROSS
THE CENTRAL ROCKIES AHEAD OF THE NEXT SHORTWAVE TROUGH IN THE
UPPER FLOW...WHICH IS CURRENTLY LOCATED ACROSS IDAHO. AT THE
SURFACE A TROUGH OF LOW PRESSURE IS IN PLACE ACROSS EASTERN
COLORADO WITH SW GRADIENT OVER CENTRAL KANSAS. TO THE WEST VERY
LOW TD VALUES HAVE MIXED TO THE SURFACE WITH -4F TO 5F TD VALUES
REPORTED ALONG THE FRONT RANGE AND EASTERN PLAINS OF COLORADO.
LUCKILY WITH GRADIENT WELL EAST AND WEAK FLOW ALOFT WINDS HAVE
BEEN LIGHT AND RFW CRITERIA IS NOT BEING MET.
THE SHORTWAVE UPSTREAM OVER THE NW US WILL MOVE EAST THROUGH
THURSDAY ACROSS THE NORTHERN PLAINS...KICKING A COLD FRONT SOUTH
ACROSS THE PLAINS AFTER MIDNIGHT TONIGHT. WITH VERY DRY AIR MASS IN
PLACE I AM ONLY ANTICIPATING THICK HIGH CLOUD COVER AND POSSIBLE
BREEZY WINDS BEHIND THE FRONT LATE TONIGHT THROUGH THURSDAY
MORNING. THESE CONDITIONS SHOULD HOLD OVERNIGHT TEMPS ABOVE
FREEZING (MID TO UPPER 30S) DESPITE DECENT CAA BEHIND COLD FRONT.
AFTER A MILD DAY TODAY WE WILL BE LOOKING AT HIGHS CLOSER TO
SEASONAL NORMALS ON THURSDAY WITH VALUES RANGING FROM THE LOW TO
UPPER 50S.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1154 PM MST TUE NOV 12 2013
MOST OF THE EXTENDED PERIOD WILL SEE A LONGWAVE TROUGH OVER THE
CENTRAL ROCKIES AND ADJACENT PLAINS WITH EMBEDDED SHORTWAVES
RESULTING IN OCCASIONAL CHANCES FOR LIGHT PRECIPITATION AND BELOW
NORMAL TEMPERATURES. BEST CHANCES FOR PRECIPITATION WILL BE WITH
THE MAIN TROUGH AXIS ON SUNDAY WITH RAIN CHANGING TO SNOW FROM THE
NORTHWEST AS COLDER AIR FILTERS INTO THE REGION. HOWEVER...ALL
MODELS NOW SHOWING AN OPEN WAVE WHICH WILL KEEP QPF/SNOW
ACCUMULATIONS ON THE LIGHT SIDE. COLDEST TEMPERATURES WILL FOLLOW
ON MONDAY THEN SLOW MODERATION THROUGH THE END OF THE PERIOD AS
UPPER RIDGING GRADUALLY REBUILDS FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1008 AM MST WED NOV 13 2013
VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE
PERIOD. SOUTHERLY WINDS 8-12KT WILL CONTINUE THROUGH THE EARLY TAF
PERIOD AT BOTH TAF SITES WITH SW FLOW AHEAD OF SURFACE TROUGH.
SURFACE TROUGH WILL SHIFT EAST THIS EVENING WITH WINDS BECOMING
VARIABLE AROUND 3-6KT. COLD FRONT WILL DROP SOUTH IN THE 06-09Z
TIME PERIOD WITH WINDS SHIFTING TO THE NORTH-NORTHWEST AND
INCREASING TO 10-14KT RANGE THROUGH THE END OF THE TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1218 PM CST WED NOV 13 2013
.UPDATE...
ISSUED AT 1218 PM CST WED NOV 13 2013
WILL AGAIN INCREASE TEMPERATURES FOR THIS AFTERNOON A FEW
DEGREES...MAINLY FOLLOWING THE HRRR GUIDANCE (WHICH IS HANDLING
THE CURRENT VALUES...DEEPER MIXING...THE BEST).
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 328 AM CST WED NOV 13 2013
850 MB THERMAL RIDGE OVER THE FCST AREA EARLY THIS MORNING. HIGHER
TERRAIN LOCATIONS ON THE WESTERN EDGE OF THE RED RIVER VALLEY QRE
IN THE MID 30S WITH SOUTHWEST WIND GUSTING TO 20 KTS AT TIMES
WHILE REST OF THE AREA MORE IN THE MID 20S. SFC TROUGH WILL PASS
THROUGH ERN ND THRU MIDDAY AND INTO MN THIS AFTERNOON. SOUTH TO
SOUTHWEST WINDS WILL TURN MORE WESTERLY. WHILE THERMAL RIDGE AT
850 MB WILL SLIDE EAST OF OUR AREA DURING THE COURSE OF THE DAY A
FAVORABLE WIND DIRECTION SHOULD ALLOW TEMPS TO REACH WELL INTO THE
40S TO AROUND 50. ONE CAVEAT IS THICKNESS OF HIGH CLOUDS. RIGHT
NOW ONE PATCH OF THIN CLOUDS OVER NE ND WHILE A BIT THICKER BATCH
ALONG TROUGH...THEN CLEARING BEHIND IT. IF WE GET A GOOD DEAL OF
SUN ALONG WITH THE WEST WIND COULD SEE RED RIVER VALLEY LOCATIONS
RISE A BIT HIGHER THAN FCST AS OFTEN TEMPS OVER PERFORM ON WEST
WIND DAYS.
WINDS TO DIMINISH EARLY THIS EVE. A SHORT WAVE CAUSING SOME LIGHT
PRECIP IN CNTRL/NRN BRITISH COLUMBIA WILL MOVE SOUTHEAST AND
LATEST MODEL RUNS ARE NOT TOO IMPRESSIVE AND ARE A BIT FARTHER
NORTH TAKING MOST PRECIP IN SRN MANITOBA AND FAR NRN ND/NW MN. DID
ADJUST LOW POPS A BIT FARTHER NORTH BUT STILL KEPT POPS LOW AS
SYSTEM IS FAST MOVING AND MOISTURE STARVED. PRECIP TIMING WOULD
HAVE LOW CHANCES INTO NE ND 06Z-12Z THU INTO NW MN 12Z-18Z THU.
WENT LIGHT SNOW TURNING TO A MIX OR LIGHT RAIN AS TEMPS WARM
THURSDAY. MINOR PRECIP EVENT SO NOT EXPECTING MUCH.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 AM CST WED NOV 13 2013
WEAK 850 MB COOLING BEHIND SYSTEM THU NIGHT THEN WINDS TURN
SOUTHERLY ON FRIDAY AND A WEAK SHORT WAVE IS PROGGED TO MOVE THRU
SE ND INTO MN LATE FRI INTO FRI NIGHT AND COORD WITH OTHER OFFICES
INTRODUCED LOW POPS FOR THIS SYSTEM. AGAIN MOISTURE STARVED SO ANY
PRECIP VERY VERY LIGHT.
FOR SATURDAY INTO EARLY NEXT WEEK...LONG WAVE UPPER AIR PATTERN
HAS SHIFTED UPPER TROUGH AXIS FROM EASTERN NORTH AMERICA TO
CENTRAL CANADA AND THE WESTERN US. GFS WAS SLIGHTLY FASTER
SOLUTION AT DAY 4 THAN THE ECMWF. BY THE END OF THE PERIOD THE
ECMWF BECOMES FASTER THAN THE GFS. WILL PREFER THE FASTER ECMWF.
WITH DIGGING TROUGH IN THE WEST MODELS HAVE BEEN SHIFTING PRECIP
NORTH LAST COUPLE MODEL RUNS. WILL REMOVE POPS NORTHERN ND FOR SAT
AND NORTHWESTERN ZONES FOR SUN AND MUCH OF THE NORTH SUN NIGHT.
PUSHED PRECIP EAST ON MON.
TEMPERATURES HAVE BEEN LOWERED BY ABOUT 2 DEGREES THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1218 PM CST WED NOV 13 2013
EXPECT VFR CIGS THIS AFTERNOON AND TONIGHT. A WEAK SYSTEM WILL
MOVE ACROSS SOUTHERN CANADA TOMORROW MORNING...AND MVFR CIGS CAN
BE EXPECTED TO MOVE INTO NORTHERN SITES (GFK...BJI AND DVL) BY
12Z. MVFR CIG COVERAGE MAY EXPAND FURTHER SOUTH LATER IN THE
MORNING. THERE IS A CHANCE FOR LIGHT SNOW AT TVF AND GFK MID
MORNING AS WELL...BUT CONFIDENCE ON EXACT TIMING STILL TOO LOW TO
MENTION IN THE TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...RIDDLE
LONG TERM...HOPPES/RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS PORTLAND OR
921 AM PST WED NOV 13 2013
.SYNOPSIS...HIGH PRESSURE WILL BRIEFLY MOVE OVER THE THE REGION
TODAY. AN UPPER LEVEL TROUGH WILL BRING LIGHT RAIN AND MOUNTAIN SNOW
TO THE AREA THURSDAY. A STRONGER SYSTEM WILL BRING MORE SUBSTANTIAL
SNOW TO THE CASCADES AS WELL AS GUSTY WINDS TO MUCH OF THE REGION
FRIDAY NIGHT INTO SATURDAY MORNING. COOL AND DRY OFFSHORE FLOW IS
EXPECTED LATE SUNDAY INTO MONDAY. A PROGRESSIVE WEATHER PATTERN WILL
CONTINUE TO BRING SERIES OF FRONTS THROUGH THE AREA NEXT WEEK
&&
.UPDATE...MADE MINOR CHANGES TO SKY...WEATHER...AND POPS IN THE SHORT
TERM WITH THE MORNING UPDATE. A VERY WEAK FRONT IS MOVING THROUGH THE
AREA...GENERATING LIGHT RAIN OVER THE TERRAIN. THE FOG AND LOW CLOUDS
WILL LINGER IN THE SOUTHERN VALLEYS THROUGH MUCH OF THE AFTERNOON
TODAY.OTHERWISE EVERYTHING LOOKS ON TRACK WITH A COUPLE OF SYSTEMS
BRINGING RAIN WITH PASS LEVEL SNOW THURSDAY EVENING AND FRIDAY NIGHT.
THE THURSDAY SYSTEM LOOKS WEAK AND BRIEF...BUT THE FRIDAY
NIGHT/SATURDAY STORM IS BACKED BY A 140+KT 250MB JET AND WILL LIKELY
HAVE BLUSTERY WINDS ACCOMPANIED WITH PERIODS OF HEAVY PRECIPITATION
THAT MAY IMPACT TRAVEL ACROSS THE CASCADES.
PREVIOUS DISCUSSION WRITTEN 330 AM...WEDNESDAY THROUGH FRIDAY
NIGHT...
OUR UPPER LEVEL LOW THAT WAS RESPONSIBLE FOR THE WIDESPREAD RAIN
YESTERDAY HAS PUSHED NORTH INTO CENTRAL B.C. AND IS NOW GETTING
SHOVED INLAND AS ANOTHER UPPER LOW TAKES ITS PLACE IN THE GULF
ALASKA. THE FORMER IS DRAGGING A WEAK FRONTAL BOUNDARY THROUGH
WASHINGTON STATE. REMNANTS OF THIS BOUNDARY WILL BRING A SHOWER OR
TWO TO THE NORTHERN TIER TODAY...WITH THE NORTH COAST AND ELEVATED
TERRAIN FAVORED. SURFACE HIGH PRESSURE IS ANCHORED FARTHER SOUTH AND
RESULTING IN A MIX OF FOG AND LOW CLOUDS THROUGH THE VALLEY.
WITH THE FRONT BEING RATHER BENIGN PUSHING QUICKLY TO OUR EAST
TODAY...OUR ONLY REAL NEAR TERM CONCERN IS THE FOG. ONE WOULD EXPECT
THE FOG TO BECOME DENSE WITH HIGH PRESSURE IN PLACE...BUT THE FRONT
MOVING THROUGH IS STIRRING THINGS UP A BIT. IT HAS BECOME DENSE AT
TIMES AND EXPECT WITH SUCH LOW DEWPOINT DEPRESSIONS THIS TREND WILL
CONTINUE. THE HRRR CONTINUES TO SUGGEST SFC VISIBILITY BELOW A HALF
MILE FOR MUCH OF THE VALLEY THIS MORNING...SO THERE WILL LIKELY BE
DENSE FOG IN SPOTS AND/OR WIDELY VARYING VISIBILITIES DURING THE
MORNING COMMUTE...ESPECIALLY FURTHER SOUTH. RELATIVELY LIGHT FLOW
WILL MEAN A SLOW CLEARING TODAY...WITH THE CENTRAL AND SOUTH VALLEY
STRUGGLING TO BREAK OUT AT ALL.
THE UPPER LOW NOW IN THE GULF OF ALASKA SWINGS THROUGH LATER
THURSDAY AFTERNOON AND EVENING FOR SOME SHOWERS. SNOW LEVELS WILL
BE AROUND 3500-4000 FT WITH THIS FIRST WAVE...A BIT OF A WARMUP FOR
THE NEXT FRONT ON FRIDAY...AND WILL BEGIN A PERIOD OF MOUNTAIN SNOW
FOR A FEW DAYS. WE WILL HAVE BRIEF RIDGING ON THURSDAY NIGHT THUS
JUST SOME LINGERING CASCADE SNOW SHOWERS.
A STRONGER SYSTEM CURRENTLY STILL TAKING SHAPE WEST OF ALASKA WILL
DIG SOUTH THROUGH THE REGION ON FRIDAY MAINLY DURING THE AFTERNOON
AND EVENING PERIOD. THIS SYSTEM WILL HAVE A MUCH STRONGER COLD FRONT
WITH IT...BETTER MOISTURE AVAILABILITY...AND IT WILL ALSO PACK QUITE
A BIT OF WIND. SNOW LEVELS WILL DROP TO THEIR LOWEST
LEVELS YET. THIS FRONT WILL HAVE A BIT OF WIND WITH IT AS COLDER AIR
FILTERS SOUTH INTO THE REGION. EXPECT THAT FRIDAY...ESPECIALLY THE
LATTER PORTION WILL BE RATHER WET FOR THE LOWLANDS. SNOW LEVELS START
OFF IN THE AFTERNOON IN THE 3000-3500 FT RANGE...BUT THEN THEY DROP
TO ABOUT 2000 FEET IN THE EVENING AND OVERNIGHT...POSSIBLY GETTING AS
LOW AS 1500 FEET BY EARLY SATURDAY. A STRONG UPPER LEVEL JET WILL
COME DOWN THE OFFSHORE SIDE OF THIS INSIDE SLIDER COUPLED WITH STRONG
925-850 MB FRONTOGENESIS ALONG AND BEHIND THE SURFACE FRONT...MEANING
THE FORCING WILL BE AROUND EVEN ON THE COLD SIDE OF THIS SYSTEM.
COUPLE WITH 850 WINDS IN EXCESS OF 30-35 KT AND 700 MB WINDS UPWARDS
OF 60 KT...AND THIS WILL ALLOW FOR A PERIOD OF MODERATE TO HEAVY SNOW
AND WINDY CONDITIONS IN THE MOUNTAINS FRIDAY LATER AFTERNOON OR
EVENING. BE PREPARED FOR WINTER DRIVING CONDITIONS. KMD
.LONG TERM...SATURDAY THROUGH MID WEEK...BEHIND THE FRONT
FRIDAY...THE REGION REMAINS IN CYCLONIC FLOW ON THE BACK SIDE...AND
MODERATE WESTERLY FLOW WILL CONTINUE THE SHOWERS WITH SNOW LEVELS
HANGING IN THE 2000-2500 FOOT RANGE IN THE CASCADES. HIGH PRESSURE
LOOKS TO BUILD IN FROM SOUTH TO NORTH SUNDAY THOUGH THERE MAY BE SOME
LINGERING MOUNTAIN SNOW SHOWER. COOL AND DRY OFFSHORE FLOW LOOKS TO
SET UP ON MONDAY. LONGER RANGE MODELS WANT TO BRING THE NW INTO MORE
PROGRESSIVE WESTERLY PACIFIC FLOW WHICH TENDS TO MEAN MILD AND
RELATIVELY WET CONDITIONS FOR MID WEEK. KMD
&&
.AVIATION...FAIRLY WIDESPREAD IFR/LIFR CONDITIONS IN THE LOWLANDS
THIS MORNING. LIGHT WINDS AND ABUNDANT LOW LEVEL MOISTURE WILL
CAUSE THESE LOW CIGS/VSBYS TO BE PERSISTENT TODAY...WITH ONLY VERY
GRADUAL IF ANY CLEARING THIS AFTERNOON. BEST CHANCE FOR A BREAKOUT
TO VFR WILL BE IN OUR NORTHERN ZONES...KSLE SOUTHWARD WILL LIKELY
STAY IFR ALL DAY AS LIGHT NORTHERLY FLOW KEEPS LOW-LEVEL MOISTURE
PACKED UP AGAINST THE CENTRAL/SOUTH WILLAMETTE VALLEY.
KPDX AND APPROACHES...IFR CIGS WITH AREAS OF LIFR IN FOG THIS
MORNING...SHOULD SLOWLY LIFT TO LOW MVFR BY 20Z-21Z. SOME CLEARING
IS POSSIBLE LATE THIS AFTERNOON...AROUND 23Z...BUT CONFIDENCE IS
LOW. WEAGLE
&&
.MARINE...FAIRLY TRANQUIL CONDITIONS FOR THE NEXT COUPLE DAYS.
WILL SEE HIGH PRESSURE BRIEFLY DOMINATE TO THE WEST WITH WEAK LOW
PRESSURE AREAS TRANSITING SOUTH OVER THE AREA. HAVE ALREADY TURNED
PRIMARY ATTENTION TO A VIGOROUS SYSTEM APPROACHING FRIDAY.
DEVELOPING LOW PRESSURE WILL SLIDE SOUTH ALONG THE B.C. COAST
BEFORE PUSHING FURTHER INLAND TOWARD NORTHEAST WASHINGTON. WILL
SEE QUITE THE DYNAMIC FETCH SET UP ON THIS TRAJECTORY. SOLID SMALL
CRAFT ADVISORY SW PRE-FRONTAL WINDS WILL CROSS THE WATERS FRIDAY
EVENING. STRONG COLD ADVECTION WILL PROVIDE EXCELLENT CONDITIONS
FOR MIXING STRONGER WINDS FROM ALOFT DOWN TO THE SURFACE...WITH
FREQUENT GALE GUSTS LOOKING LIKELY ALONG WITH AND BEHIND THE FRONT.
UNLESS SIGNIFICANT CHANGES SHOW UP IN THE NEXT ROUND OF MODEL
RUNS...WE WILL LIKELY ISSUE A GALE WATCH FOR THIS EVENT WITH THE
AFTERNOON PACKAGE. FEEL WIND WAVE/FRESH SWELL DOMINATED SEAS WILL
APPROACH AT LEAST 20 FT FOR THE NORTHERN OUTER WATERS...WITH UPPER
TEENS CLOSER TO SHORE EARLY SATURDAY. SINCE THESE WAVES WILL BE
FRESHLY GENERATED...PERIODS WILL BE SHORT AND THUS THE SEAS WILL
BE VERY STEEP AND HAZARDOUS.
CONDITIONS GRADUALLY EASE SUNDAY WITH HIGH PRESSURE BUILDING OVER
THE REGION FOR EARLY NEXT WEEK. WEAGLE/JBONK
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 251 PM CST WED NOV 13 2013
LOW PRESSURE OVER NORTHWEST ONTARIO COUPLED WITH STRONG HIGH
PRESSURE CENTERED OVER KENTUCKY HAS LEAD TO STRONG PRESSURE
GRADIENT OVER THE FORECAST AREA LATE THIS AFTERNOON. SO FAR MAX
WINDS GUSTS HAVE BEEN GENERALLY IN THE 35 TO 40 MPH RANGE ALONG
THE LAKESHORE COUNTIES FROM MANITOWOC TO DOOR COUNTY. HRRR AND RAP
SUGGEST THAT GRADIENT WILL LIKELY STRENGTHEN A BIT MORE AS WE
APPROACH THE EARLY EVENING...THEN SLACKEN SOMEWHAT AFTER MIDNIGHT.
THUS EXPECT SOUTHWESTERLY WIND GUSTS OF SIMILAR MAGNITUDE TO
CONTINUE UNTIL ABOUT 03Z THIS EVENING. OVER DOOR COUNTY MAX WIND
GUSTS EXPECTED TO BE SOMEWHAT HIGHER...CLOSER TO 45 MPH INTO EARLY
EVENING. GENERALLY FAIR SKIES OVERNIGHT TONIGHT WITH LOWS WARMER
THAN LAST NIGHT MAINLY IN THE 25 TO 30 DEGREE RANGE.
LATEST SUITE OF MODEL GUIDANCE CONTINUES TO ADVERTISE PASSAGE OF
RELATIVELY WEAK AND PROGRESSIVE SHORTWAVE DISTURBANCE THURSDAY
AFTERNOON WITHIN FLAT ZONAL FLOW. PRIMARY FORCING WITH THIS
SYSTEM MAINLY ASSOCIATED WITH RRQ OF UPPER JET AND SOME MODEST
FRONTEGENETIC FORCING. GUIDANCE HAS BEEN FAIRLY CONSISTENT IN
DEPICTING A RELATIVELY NARROW BAND OF MOISTURE AHEAD OF WEAK
SURFACE FRONT. A FEW OF THE MODELS THAT WERE PREVIOUSLY
DRY...INCLUDING THE REG GEM AND WRFARW...ARE NOW SHOWING A NARROW
BAND OF VERY LIGHT QPF TO MOVE RATHER QUICKLY ACROSS THE AREA
BEWTEEN ABOUT 18Z THURSDAY AND 00Z FRIDAY. ONLY MODIFIED POPS
UPWARD SLIGHTLY BUT REMAINED IN CHANCE CATEGORY. STILL APPEARS
THAT NORTHCENTRAL WISCONSIN WILL HAVE THE GREATEST CHANCE TO SEE
SOME VERY LIGHT AND SCATTERED RAIN SHOWER ACTIVITY. AS SYSTEM IS
VERY PROGRESSIVE WITH WEAK FORCING...DO NOT EXPECT MORE THAN SOME
WIDELY SCATTERED AMOUNTS OF MAYBE A FEW HUNDRETHS OF AN INCH. WILL
SEE A GRADUAL INCREASE IN HIGH TO MID-LEVEL CLOUDS THROUGHOUT THE
MORNING AS THE SYSTEM APPROACHES. EXPECT MAX TEMPS TO BE GENERALLY
SIMILAR TO TODAY WITH READINGS IN THE 40 TO 45 DEGREE RANGE.
BOUNDARY LAYER WINDS WILL BE CONSIDERABLY MORE MODEST ON THURSDAY
COMPARED TO TODAY AS GRADIENT BAGGIER WITH APPROACHING SURFACE
FRONT.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 251 PM CST WED NOV 13 2013
UPPER LEVEL FLOW SHIFTS DURING THE PERIOD AS A STRONG NORTH-SOUTH UPPER
JET MAX...IN EXCESS OF 160 KNOTS...ACROSS THE WEST COAST OF CANADA
HELPS TO AMPLIFY A TROUGH IN THE WESTERN CONUS. CONDITIONS SHOULD
BE RELATIVELY QUIET THROUGH THE END OF THE WORK WEEK. RAIN IS
EXPECTED TO MOVE INTO THE AREA DURING THE WEEKEND AS A SURFACE LOW
DEVELOPS IN THE PLAINS...WITH A STRONG FLOW OF WARM AND MOIST AIR AHEAD
OF IT. HIGHS WILL BE MUCH ABOVE NORMAL ON SATURDAY AND SUNDAY.
THE 12Z GEM AND 12Z GFS HAD THE FIRST OF TWO SURFACE LOWS PASSING
THROUGH NORTHWEST WI/NORTHEAST MN SATURDAY NIGHT...WITH A SECOND
LOW PASSING THROUGH SOUTHEAST WISCONSIN SOMETIME ON SUNDAY. BOTH
OF THESE MODELS SHOWED A PRETTY WIDESPREAD AREA OF QPF OVER THE
WEEKEND...WITH THE GFS INDICATING QPF AND MUCH COLDER AIR BEHIND
THE SYSTEM. THE 12Z ECMWF HAD A SINGLE...STRONGER SURFACE LOW THAT
WAS FORECAST TO PASS ACROSS NORTHWEST WI SUNDAY AFTERNOON AND
EVENING. IT ALSO HAD SOME LINGERING PRECIPITATION FORECAST BEHIND
THE DEPARTING SYSTEM. RAIN IS LIKELY FOR THE WEEKEND...AND THERE IS
A CHANCE OF PRECIPITATION SUNDAY NIGHT AND MONDAY...CHANGING FROM
RAIN TO SNOW FROM NORTHWEST TO SOUTHEAST. KEPT A CHANCE FOR SNOW
SHOWERS IN THE NORTH LINGERING INTO MONDAY NIGHT.
MUCH COLDER TEMPERATURES ARE IN STORE FOR NEXT WEEK WITH SURFACE
HIGH PRESSURE OVER THE AREA AND A SHIFT TO NORTHWEST FLOW ALOFT.
HIGHS ARE ONLY EXPECTED TO BE AROUND 30 DEGREES FOR THE MIDDLE
PART OF THE WEEK.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 251 PM CST WED NOV 13 2013
VFR CONDITONS EXPECTED TO PREVIAL THROUGH THURSDAY. SW LLWS WILL
PERSIST OVER CENTRAL WISCONSIN TAFS SITES THROUGH ABOUT 06Z AND
UNTIL ABOUT 12Z THURSDAY AT EASTERN LOCATIONS. GRADUAL INCREASE
IN HIGH TO MID-LEVEL CLOUDS THURSDAY MORNING AHEAD OF WEAK
DISTURBANCE FORECAST TO MOVE QUICKLY EASTWARD ACROSS THE FORECAST
AREA THURSDAY AFTERNOON. SYSTEM IS PROGRESSIVE WITH WEAK
FORCING...THUS EXPECT ONLY NARROW SW-NE ORIENTATED CORRIDOR OF LIGHT
SHOWER ACTIVITY WITH CIGS REMAINING MOSTLY IN THE VFR CATEGORY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......MG
AVIATION.......ESB