Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/16/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1228 PM MST MON DEC 14 2015
.SYNOPSIS...
A FAST MOVING WEATHER SYSTEM THAT BROUGHT DESERT RAIN AND MOUNTAIN
SNOW TO ARIZONA TODAY WILL RAPIDLY MOVE OUT OF THE AREA TONIGHT.
BEHIND THIS SYSTEM VERY COLD AIR WILL SETTLE OVER THE REGION...WITH
WELL BELOW NORMAL HIGH TEMPERATURES AND SUB-FREEZING LOW
TEMPERATURES LIKELY FOR MUCH OF THIS WEEK. DRY AND COLD WEATHER WILL
PERSIST INTO THE WEEKEND.
&&
.DISCUSSION...
UPPER LOW CONTINUES TO SLOWLY CIRCULATE ACROSS NEVADA/UTAH THIS
AFTERNOON ALTHOUGH THE MAIN TROUGH AXIS HAS SHIFTED EAST. THE MAIN
BAND OF PRECIPITATION HAS MIGRATED EAST OF PHOENIX AND IS NOW A
RAIN/SNOW MIX ABOVE 4500 FEET /WITH SOME LOCALIZED LIGHT SNOW
POSSIBLE DOWN TO 3500 FEET/. ALSO STARTING TO SEE SOME VERY ISOLATED
INSTABILITY SHOWERS ACROSS THE WESTERN FORECAST AREA AS A SECONDARY
SHORTWAVE TROUGH IS MAKING ITS WAY SOUTHWARD. THIS TROUGH IS ALSO
ENTERING AN AIRMASS WHERE DEWPOINTS HAVE DROPPED CONSIDERABLY INTO
THE TEENS AND 20S. THUS FAR THERE HAVEN`T BEEN ANY ADDITIONAL
RAINFALL REPORTS ACROSS SOUTHEAST CALIFORNIA OR SOUTHWEST
ARIZONA...BUT IT CERTAINLY WARRANTS SOME SORT OF MENTION IN THE
FORECAST NONETHELESS. MEANWHILE...TEMPS CONTINUE TO STRUGGLE TODAY.
MID DAY READINGS IN THE UPPER 40S TO LOWER 50S ARE COMMON ACROSS THE
DESERTS AND THIS WILL BE PAR FOR THE COURSE THE NEXT FEW DAYS.
IN THE VERY SHORT TERM...PRECIP WILL GRADUALLY TAPER OFF THIS EVENING
AND OVERNIGHT. GIVEN THE RELATIVELY WIDESPREAD RAINFALL OF 0.1-0.3
INCHES ACROSS THE AREA...FOG IS A BIT OF A CONCERN. ALWAYS TOUGH TO
DETERMINE IF DRY ADVECTION FROM THE NORTHWEST AND ELEVATED MIXING
WILL WIN THE BATTLE VS. LINGERING LOW LEVEL MOISTURE. ALSO OF CONCERN
IS THE POSSIBILITY OF SOME HIGH CLOUDS MOVING INTO THE AREA LATE
TONIGHT WHICH COULD MITIGATE THE FOG THREAT. GIVEN QUITE A FEW MODELS
SUGGESTING ELEVATED DEWPOINTS THROUGH 12Z...I`M GOING TO INTRODUCE A
RELATIVELY LARGE AREA OF PATCHY FOG FOR MARICOPA AND NW PINAL
COUNTIES /GENERALLY THE ONLY AREAS THAT SAW APPRECIABLE RAINFALL/.
SOUTHERN GILA COUNTY WILL LIKELY STAY CLOUDY OVERNIGHT BUT COULD SEE
SOME VALLEY FOG IN SOME SPOTS.
TEMPERATURES...COLD TO SAY THE LEAST. TONIGHT WILL SEE THE BEGINNING
OF AT LEAST 2 OR 3 NIGHTS WHERE TEMPS APPROACH OR DROP BELOW FREEZING
IN THE OUTLYING DESERT AREAS. LATEST BLENDED RAW GUIDANCE MAINTAINS
TEMPS IN THE MID 30S ACROSS THE OVERWHELMING MAJORITY OF THE LOWER
DESERT LOCALES ALTHOUGH THE TYPICAL COLD SPOTS IN NORTHWEST PINAL
COUNTY COULD FALL INTO THE UPPER 20S. SHOULD NOT SEE WIDESPREAD
FREEZES LATE TONIGHT. CERTAINLY A DIFFERENT STORY WEDNESDAY AND
THURSDAY MORNINGS AS THE COLDEST TEMPS OF THE SEASON THUS FAR ARE
EXPECTED. WITH THE NORMALLY WARM AREAS OF DOWNTOWN PHOENIX FORECAST
TO DROP INTO THE MID 30S...LOW TO MID 20S SEEMS LIKE A LOCK FOR THE
OUTLYING DESERTS...THUS WE ISSUED A FREEZE WATCH WEDNESDAY MORNING
AND THURSDAY MORNING. ELECTED NOT TO INCLUDE YUMA OR SOUTHEAST
CALIFORNIA AS WINDS SHOULD STAY ELEVATED AND THE BULK OF THE VERY
COLD AIR LOOKS POISED TO REMAIN CONFINED TO ARIZONA. SOME WARMING IS
FORECAST LATE IN THE WEEK AS WEAK UPPER LEVEL SHORTWAVE RIDGING
BEGINS TO TAKE HOLD OVER THE AREA.
FRIDAY INTO THE FIRST PART OF THE WEEKEND...HIGH PRESSURE ALOFT WILL
BUILD ACROSS THE DESERT SOUTHWEST LEADING TO DRY CONDITIONS AND
WARMER HIGH TEMPERATURES. HIGHS FRIDAY WILL REACH INTO THE MID 60S
OVER MOST OF THE DESERTS...AND THEY WILL CLIMB FURTHER AND INTO THE
UPPER 60S TO AROUND 70 ON SATURDAY. INCREASING HIGH CLOUDS ARE
EXPECTED SATURDAY FOR PARTLY SUNNY SKIES.
ANOTHER CHANGE IN THE WEATHER PATTERN IS EXPECTED STARTING SUNDAY AS
ANOTHER PACIFIC LOW PRESSURE SYSTEM IS FORECAST TO MOVE INTO THE
DESERT SOUTHWEST BRINGING INCREASING CLOUDS...MOISTURE AND A SLIGHT
CHANCE FOR SHOWERS OVER SERN CA AND SOUTHWEST AZ BY SUNDAY
AFTERNOON. THIS IS SUPPORTED BY NAEFS ENSEMBLE GUIDANCE AS WELL AS
LATEST GFS AND ECMWF OPERATIONAL RUNS. COOLER...WET AND UNSETTLED
CONDITIONS WILL PERSIST INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND
KSDL...
THROUGH 19Z MON...COLD FRONTAL PASSAGE ARND 16Z MON. BKN CLDS 4-6
THSD AGL WITH SCT RAIN SHWRS. SE WIND 6 TO 10 KNOTS...SHIFTING TO
THE WEST 15 TO 25 KNOTS WI FRONTAL PASSAGE. FROM 19Z MON TO 02Z
TUE...CLDS LIFTING TO BKN 6-7 THSD AGL WITH ISOLD R SHWR. WEST WIND
15 TO 25 KNOTS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
THROUGH 16Z MON...COLD FRONTAL PASSAGE. BKN CLDS 6-8 THSD AGL WITH
ISOLATED R SHWR. WEST WIND 15 TO 25 KNOTS. FROM 16Z MON TO 02Z
TUE...SCT CLDS 6 TO 8 THSD AGL. NW WND 15 TO 20 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRY WEST TO NORTHWEST FLOW ALOFT. PARTLY CLOUDY AT TIMES. LIGHT
NORTHEAST WIND 5 TO 10 MPH. MINIMUM RELATIVE HUMIDITY GENERALLY FROM
20 TO 30 PERCENT. BELOW NORMAL TEMPERATURES WEDNESDAY AND THURSDAY...
WARMING TO NEAR NORMAL FRIDAY AND THE WEEKEND.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR
AZZ020>023-026>028.
FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
AZZ020>023-026>028.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/CB
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ
Area Forecast Discussion
National Weather Service Sacramento CA
1034 AM PST MON DEC 14 2015
.SYNOPSIS...
Pacific storm has exited the region. Mostly dry weather with
seasonal temperatures today through Wednesday. Wet pattern returns
Thursday into next week.
&&
.DISCUSSION...
Only made some minor changes to today`s forecast. The HRRR shows
lingering showers this morning, but mainly over the NorCal
coastline so have reduced the mention of showers in our CWA.
Expect dry & mild weather into midweek with a wet pattern
returning by the end of the week. JBB
.Previous Discussion...
Other than some early morning patchy frost in the valley, and a
few lingering snow showers in the mountains today, rather benign
weather is expected the next several days across the region. Cool
overnight temperatures are expected, but daytime temperatures will
be close to average for mid-December. Breezy northerly winds will
develop today across the Central Valley and continue into Tuesday
before diminishing on Wednesday.
Moisture moving over the eastern Pacific may begin to spill into
far northern California as early as Wednesday night bringing an
increase in clouds to the region along with a chance for light
precipitation across the northern mountains and northern
Sacramento Valley heading into Thursday.
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
Overrunning precip may bring some rain across much of the area
Friday. Models agree that the trough tries to cutoff as the
access reaches 125W over the weekend; however, the GFS is about
12 hours quicker. Both depict a decent shot of precipitation and
lowering snow levels, but as good as if the system doesn`t cut
off. Slightly cyclonic northwest flow behind the main trough
brings a better chance for precipitation Monday. JClapp
&&
.AVIATION...
VFR conditions through the period for TAF sites. Breezy northerly
winds across the Sac and San Joaquin valleys through the evening
hours with gusts 25-30 kts possible.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS RENO NV
1005 PM PST SUN DEC 13 2015
.UPDATE...
MOST BANDED PRECIPITATION HAS DIMINISHED ACROSS THE TAHOE BASIN
THROUGH PORTIONS OF WESTERN NEVADA. AS SUCH HAVE ALLOWED THE
WINTER STORM WARNING TO EXPIRE ACROSS THE TAHOE BASIN AND HAVE
CANCELLED THE WINTER WEATHER ADVISORY FOR THE GREATER RENO-CARSON
CITY-MINDEN REGION. A FEW LINGERING LIGHT SNOW SHOWERS WILL BE
POSSIBLE OVER THE NEXT FEW HOURS SOUTH OF HWY 50 THROUGH THE TAHOE
BASIN AND ALSO SOUTH OF MINDEN. FUENTES
&&
.PREVIOUS DISCUSSION... /ISSUED 710 PM PST SUN DEC 13 2015/
UPDATE...
JUST A QUICK UPDATE TO ALLOW THE WINTER STORM WARNING AND WINTER
WEATHER ADVISORY TO EXPIRE FOR PORTIONS OF NORTHEAST CALIFORNIA
INCLUDING LASSEN COUNTY AND THE SURPRISE VALLEY. SNOWFALL HAS
DIMINISHED ACROSS THESE AREAS BUT A FEW SNOW SHOWERS ARE POSSIBLE
OVER THE NEXT FEW HOURS THROUGH THE SIERRA VALLEY WITH AN
ADDITIONAL INCH OF ACCUMULATION POSSIBLE.
ELSEWHERE, A NW-SE ORIENTED BAND OF SNOWFALL CONTINUES FROM ABOUT
PORTOLA THROUGH SOUTH RENO AND TO JUST NORTH OF WALKER LAKE. THIS
BAND WILL CONTINUE TO TRACK SOUTH TONIGHT WITH AN ADDITIONAL 1-2
INCHES OF ACCUMULATION POSSIBLE IN HEAVIER PORTIONS OF THE BAND.
MOTORISTS SHOULD STAY CAUTIOUS OF ICE FORMING ON UNTREATED ROAD
SURFACE TONIGHT ESPECIALLY IN THE RENO AREA. NDOT ROAD CAMS
INDICATE THAT THE LIGHT SNOWFALL WE RECEIVED EARLIER HAS MELTED.
THIS PRESENTS A THREAT TO FORM ICE ON ROADS TONIGHT AS
TEMPERATURES DIP BELOW FREEZING. FUENTES
PREVIOUS DISCUSSION... /ISSUED 110 PM PST SUN DEC 13 2015/
SYNOPSIS...
A FAST MOVING STORM WILL BRING MODERATE TO HEAVY SNOW SOUTH OF
HIGHWAY 50 TONIGHT THEN EXIT TO THE EAST BY MONDAY MORNING.
SIGNIFICANT TRAVEL IMPACTS AND DELAYS ARE EXPECTED FOR THE SIERRA
THROUGH TONIGHT, WITH SLICK ROADS ALSO POSSIBLE TONIGHT IN WESTERN
NEVADA. A DRYING TREND WILL FOLLOW WITH COLD TEMPERATURES THROUGH
MIDWEEK. A POTENTIAL FOR A WINTER STORM NEXT WEEKEND EXISTS BUT
THERE IS LOW FORECAST CERTAINTY.
SHORT TERM...
SO THIS STORM HAS TAKEN ON A DIFFERENT CHARACTERISTIC THIS
AFTERNOON AS THE SFC FRONT HAS SPED UP FAR MORE THAN THE MOST
RECENT NUMERICAL MODEL GUIDANCE WOULD SUGGEST. THIS HAS RESULTED
IN HEAVY PRECIPITATION MAKING ITS WAY INTO WESTERN NEVADA WELL
AHEAD OF THE COLDEST AIR AND CAUSING PCPN INTENSITY TO SLOW IN THE
NORTHERN SIERRA EARLIER THAN FORECAST. ALL OF THIS CAN SEVERELY
IMPACT THE AMOUNT OF QPF AND SNOW THAT WE RECEIVE IN THIS STORM.
THERE IS A GLIMMER OF HOPE THAT MANY AREAS...ESPECIALLY EAST OF
THE SIERRA...COULD STILL PICK UP APPRECIABLE SNOW THIS EVENING AND
OVERNIGHT. MOST OF THE MODELS PERSIST IN DEVELOPING A BAND OF SNOW
OVER WESTERN NEVADA AND THE NORTHERN SIERRA LATER THIS EVENING AS
A SECONDARY WAVE MOVES THROUGH THE WEST NORTHWEST FLOW IN THE COLD
SECTOR OF THE UPPER TROUGH. THIS WAS THE REASON FOR EXTENDING THE
ADVISORIES FOR MONO COUNTY AND THE SIERRA FRONT AND ADDING AND
ADVISORY TO SOUTHERN LYON AND MINERAL COUNTIES. WE HAVE TO
CAUTION...HOWEVER...THAT CONFIDENCE IN THIS SOLUTION AND SNOW
AMOUNTS REMAINS QUITE LOW. WE DO THIS TO GIVE TRAVELERS A HEADS
UP THAT ROAD CONDITIONS EAST OF THE SIERRA COULD DETERIORATE
THROUGH THE EVENING.
GUSTY WINDS WERE AN ISSUE EARLIER IN THE DAY...BUT THESE HAVE
DECREASED AND ALL OF THE WIND ADVISORIES AND THE WARNING WILL BE
DROPPED.
AS THE UPPER LOW MOVES EAST MONDAY AND MONDAY NIGHT WRAP AROUND
SHOWERS ARE POSSIBLE...BUT SHOULD PRODUCE LIMITED SNOW AMOUNTS.
THE BIGGER STORY EARLY IN THE WEEK WILL BE MUCH COLDER
TEMPERATURES WITH HIGHS GENERALLY IN THE 30S IN THE VALLEYS AND
THE UPPER 20S TO NEAR 30 IN THE SIERRA. BY WEDNESDAY THESE
TEMPERATURES BEGIN TO WARM BUT WE ALSO SEE THE SIGNS OF WEAK OVER
RUNNING PCPN TRYING TO DEVELOP NEAR THE OREGON BORDER WEDNESDAY
NIGHT. 20
LONG TERM...(THURSDAY-SUNDAY)...
SO EVEN THOUGH ON THE BIG PICTURE THE LONG RANGE GUIDANCE HAS A
SIMILAR FLOW PATTERN OVER THE WESTERN US, THERE ARE SIGNIFICANT
DIFFERENCES IN STORM POTENTIAL LEADING TO FAIRLY LOW FORECAST
CONFIDENCE.
THURSDAY INTO THURSDAY NIGHT - STRONG WARM ADVECTION SCENARIO OVER
THE REGION LEADING TO INCREASED CHANCES OF PRECIP NORTH OF I-80. GFS
IS MUCH MORE ROBUST WITH QPF COMPARED TO ECMWF, SO HAVE MAINTAINED
MODERATE CHANCE POPS. IF GFS SCENARIO PANS OUT, FORECAST SOUNDINGS
AND INTENSITY OF WARM ADVECTION SUPPORT HEAVY SNOWS ACROSS MODOC
COUNTY INTO NW NEVADA. DEFINITELY WORTH WATCHING NOT ONLY FOR THIS
OUTCOME BUT ALSO POTENTIAL FOR PRECIP TO DROP FURTHER SOUTH THAN
CURRENTLY PROJECTED.
SATURDAY-MONDAY - WILL MAINTAIN LOW CHANCES FOR RAIN/SNOW MAINLY IN
THE SIERRA FOR THIS PERIOD AS THERE ARE MAJOR DIFFERENCES IN THE
GUIDANCE. GFS WOULD YIELD 2-3 BACK TO BACK MODERATE WINTER STORMS
WITHIN A PROGRESSIVE NW FLOW ALOFT, WHILE ECMWF DIGS THE STORM TRACK
FURTHER SOUTH INTO SOCAL SAT/SUN BUT STILL HAS A STORM INTO OUR
REGION MONDAY. EITHER WAY, THIS PATTERN BEARS WATCHING SINCE NEXT
WEEKEND WE`LL BE GETTING INTO THE PEAK PRE-CHRISTMAS TRAVEL PERIOD
WITH ENHANCED IMPACT POTENTIAL. CS
AVIATION...
TRICKY FORECAST WITH ONGOING WINTER STORM AND RAIN/SNOW TRANSITION
IN THE WESTERN NV VALLEYS (RNO/CXP). OVERALL FORECAST CONFIDENCE IN
THE TAFS IS ONLY LOW TO MEDIUM.
LATEST HRRR GUIDANCE AND UPSTREAM RADAR IMAGERY SUGGESTS CONTINUED
+SN IN THE SIERRA (TVL/TRK) THROUGH ~23Z BEFORE TRANSITIONING TO
SNOW SHOWERS. STRONG WIND AND SNOW AT MMH RIGHT NOW, EXPECTED TO
CONTINUE THROUGH ~3Z BEFORE FADING TO SNOW SHOWERS. NO DOUBT THERE
WILL BE SNOW ACCUMULATION IMPACTS TO RUNWAYS IN THE SIERRA, WITH
IFR/LIFR CONDITIONS.
IN WESTERN NV (RNO/CXP) STRONG S/SW WINDS WITH WIND SHEAR ON
APPROACH AND TURBULENCE ALOFT CONTINUE ~0Z BEFORE SWITCHING TO THE
W/NW AS COLD FRONT MOVES INTO THE REGION. RAIN WILL SWITCH TO
RAIN/SNOW MIX OR PERHAPS ALL WET SNOW BY 22Z BUT RUNWAY
ACCUMULATIONS HIGHLY UNLIKELY DUE TO WARM/WET GROUND AND A QUICK
TRANSITION TO SHOWERS. THIS EVENING, NAM/GFS GUIDANCE SHOW A
SECONDARY BAND OF SNOW DEVELOPING MAINLY SOUTH OF RNO THAT COULD PUT
DOWN 1-2" ACCUMULATIONS AT CXP AND NEARBY AIRFIELDS SUCH AS
NFL/HTH/YERINGTON. CONFIDENCE IN THIS FEATURE FORMING IS ONLY
LOW-MEDIUM, SO THERE`S A CHANCE IT MAY NOT HAPPEN AT ALL BUT
ENOUGH OF A RISK TO WARRANT MENTION. THE BAND OF SNOW COULD FORM
FAR ENOUGH NORTH TO AFFECT RNO BUT UNCERTAIN.
FOR MONDAY, COLD AIR OVERSPREADS THE REGION WITH NORTHERLY FLOW
ALOFT. STRONG GUSTY WINDS LIKELY IN FAVORED AREAS FOR NORTH FLOW
SUCH AS HTH/BIH/TPH. SCT-BKN VFR TO MVFR CEILINGS POSSIBLE
THROUGHOUT THE DAY WITH A FEW LIGHT SNOW SHOWERS IN THE SIERRA. CS
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING NVZ005.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM PST
MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING CAZ070.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 8 AM PST MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 8 AM PST MONDAY NVZ001.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
315 PM EST MON DEC 14 2015
.DISCUSSION...
TONIGHT-TUESDAY...
A WELL DVLPD STORM SYSTEM OVER THE MIDWEST/GREAT LAKES REGION WILL RACE
INTO THE CANADIAN MARITIMES...PULLED BY A 150-170KT JET OVER NEW
ENGLAND/ERN CANADA...AND PUSHED BY AN 80-100KT JET STREAK THAT SPANS THE
OH RIVER VALLEY TO THE DESERT SW. WHILE THIS LOW WILL DRAG A COLD FRONT
INTO THE ERN CONUS...IT WILL STEADILY OUTRUN THE SRN PORTION OF THE
FRONTAL TROF AS THE LATTER PLOWS INTO THE WRN FLANK OF A DEEP LYR RIDGE
CENTERED BTWN BERMUDA AND THE BAHAMAS. THE FRONT WILL HAVE ENOUGH FORWARD
MOMENTUM TO PUSH INTO THE BIG BEND/CAROLINA COAST...BUT WILL STALL WELL
N OF THE I-4 CORRIDOR.
THE SE CONUS RADAR MOSAIC REFLECTS A RAPIDLY DETERIORATING FRONTAL
RAINBAND OVER THE FL PANHANDLE AND THE DEEP SOUTH. RAP ANALYSIS
SHOWS MID LVL VORTICITY/UPR LVL DIVERGENCE AHEAD OF THE FRONT IS
WEAK AT BEST...WITH H50 TEMPS BTWN -3/-4C AND LAPSE RATES BLO
5.0C/KM THRU THE H85-H50 LYR. H85-H70 LAPSE RATES DO STEEPEN TO
6.0-6.5C/KM IMMEDIATELY AHEAD OF THE FRONT...BUT THESE ARE STILL
BACK OVER THE CENTRAL GOMEX AND WILL MODIFY AS THEY MIX IN WITH THE
TEPID MID LVL OVERHEAD. DEEP MOISTURE POOLING WITHIN THE FRONTAL
TROF WILL WORK ITS WAY INTO CENTRAL FL AS THE FRONT STALLS TO THE
N...BUT WILL DO SO IN A "TOP DOWN" MANNER THAT RARELY RESULTS IN
ANYTHING MORE THAN A LOW COVERAGE SHRA REGIME WITH LIMITED POTENTIAL
FOR DEEP CONVECTION.
FOG/LOW STRATUS POTENTIAL WILL BE HIGH OVERNIGHT AS FL REMAINS IN
THE WARM SECTOR OF THE STALLING FRONTAL BOUNDARY...LCL DENSE FOG
PSBL ALONG AND N OF THE I-4 CORRIDOR IN THE PREDAWN HRS. TUE PRECIP
WILL BE LIMITED TO A CHC OF SHRAS ALONG AND N OF THE I-4 CORRIDOR...
SLGT CHC S OF I-4. S/SW FLOW REGIME AND INCREASING CLOUDS WILL KEEP
MIN TEMPS TONIGHT IN THE M/U60S...ARND 15F ABV AVG. HIGHER CLOUD AND
PRECIP POTENTIAL ALONG AND N OF I-4 WILL KEEP MAX TEMPS TUE IN THE
M/U70S...S OF I-4 MAX TEMPS IN THE L/M80S...STILL 5-10F ABV AVG
AREAWIDE.
WED...
AFTER MORNING FOG AND STRATUS BURNS OFF SHOULD SEE ANOTHER WARM
AFTERNOON WITH NEAR RECORD HIGH TEMPERATURES INTO THE MID 80S WITH
CONTINUED SOUTHERLY FLOW. SFC WARM FRONT WILL LIFT INTO S GA AS SFC
LOW BEGINS TO DEVELOP ACROSS SRN LA AHEAD OF PLAINS MID LVL TROUGH.
WILL KEEP DIURNAL SHOWER CHANCES IN THE 20-30 PCT RANGE...WITH
HIGHER CHANCES ACROSS NRN AREAS IN THE AFTERNOON.
THU...
DEEPENING L/W TROUGH ACROSS THE ERN CONUS AND STRENGTHENING 140 KT
JET FROM S TX INTO THE TN VALLEY WILL INDUCE CYCLOGENESIS N GA THU
MORNING WHICH WILL MOVE QUICKLY NE THROUGH THE DAY. LOW LVL
SOUTHERLY FLOW WILL VEER TO SW INTO LATE AFTERNOON WITH DEEPENING
PREFRONTAL MOISTURE AHEAD OF THE FRONT MOVING TWD THE FL BIG BEND.
WILL FCST HIGHS INTO THE MID 80S ALL AREAS WITH A LOW CHANCE FOR
PREFRONTAL SHOWERS IN THE 20-30 PCT RANGE.
THU NIGHT AND FRIDAY...
DEEPER CONVECTION IS EXPECTED JUST AHEAD OF THE SFC COLD FRONT WHICH
WILL MOVE TOWARD THE AREA LATE THU NIGHT AND ACROSS E CENTRAL FL ON
FRIDAY. ATMOSPHERE SHOULD SUPPORT THUNDER THREAT WITH STRONG JET
INDUCED LIFT AND FRONTAL FORCING THU NIGHT INTO FRI. WILL KEEP POPS
IN THE LIKELY RANGE FRIDAY AS THE FRONT MOVES THROUGH WITH NUMEROUS
SHOWERS AND A SLIGHT CHANCE FOR STORMS. ECM APPEARS TO HAVE SPED UP
THE FRONTAL PUSH INTO THE PENINSULA...AND IS NOW MORE IN LINE WITH
THE GFS.
FRIDAY NIGHT THROUGH MONDAY...
FRONT WILL CLEAR THE AREA BY FRIDAY EVENING WITH SOME OF THE COOLEST
AIR OF THE SEASON ARRIVING FOR THE FIRST HALF OF THE WEEKEND.
NORTHERLY WINDS WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 40S
TO LOWER 50S ACROSS NRN SECTIONS FRIDAY NIGHT TO THE UPPER 50S TO
LOWER 60S S CSTL FRIDAY NIGHT AND THEN REMAIN COOL IN THE MID TO
UPPER 60S FOR HIGHS OVER MUCH OF E CENTRAL FL ON SATURDAY. SKIES
WILL BE MOSTLY SUNNY FRIDAY WITH HIGH PRESSURE BUILDING IN ACROSS
THE SE STATES. THE SFC HIGH WILL MOVE TOWARD THE CAROLINA COAST
SUNDAY INTO MONDAY WITH WINDS GRADUALLY VEERING TO ONSHORE. AFTER
ONE MORE COOL NIGHT SATURDAY NIGHT IN THE 40S INLAND TO 50S NEAR THE
COAST...LOWS WILL MODERATE INTO EARLY NEXT WEEK WITH DEVELOPING
ONSHORE FLOW. HIGHS SUNDAY AROUND 70 WILL WARM INTO THE MID TO UPPER
70S BY MONDAY OF NEXT WEEK.
&&
.AVIATION...THRU 15/18Z
SFC WNDS: THRU 14/22Z...S/SW 9-13KTS WITH OCNL G20KTS. BTWN 14/22Z-
15/02Z...BCMG S/SW 2-4KTS. AFT 15/14Z...S OF KMLB-KGIF BCMG S/SE
8-12KTS...N OF KMLB-KGIF BCMG S/SW 6-10KTS.
VSBY/WX/CIGS: THRU 15/06Z...PREVAILING VFR WITH LCL MVFR CIGS BTWN
FL020-030...BRIEF MVFR VSBYS IN ISOLD SHRAS S OF KISM-KTIX THRU
15/00Z. BTWN 15/06Z-15/14Z...INTERIOR SITES PREVAILING IFR CIGS WITH
AREAS LIFR CIGS/VSBYS IN BR/FG...COASTAL SITES PREVAILING VFR CIGS
BTWN FL040-060 WITH PTCHY MVFR CIGS/VSBYS IN BR. AFT 15/14Z...CHC
MVFR SHRAS N OF KISM-KTIX...SLGT CHC S OF KISM-KTIX.
&&
.MARINE...
TONIGHT-TUESDAY...LCL PGRAD WILL CONT TO SLACKEN OVERNIGHT AS THE
FRONTAL BNDRY PUSHING ACRS THE DEEP SOUTH/NE GOMEX STALLS ACRS THE
BIG BEND/CAROLINA COAST. GENTLE TO MODERATE SRLY BREEZE BCMG A LIGHT
TO GENTLE S/SW BREEZE OVERNIGHT...CONTG THRU THE DAY TUE. SEAS 3-4FT
NEARSHORE AND 4-5FT OFFSHORE...SUBSIDING TO 2-3FT NEARSHORE AND
3-4FT OFFSHORE.
TUE NIGHT-SAT...S/SE WINDS TUE NIGHT-WED WILL GENERALLY BE AROUND 10
KNOTS OR LESS WITH SEAS 3-4 FT TUE DECREASING TO 2-3 FT WED.
SOUTHERLY WINDS WILL INCREASE THU TO SCEC LEVELS OFFSHORE...AND
BECOME SW THU NIGHT. A STRONG COLD FRONT WILL MOVE ACROSS THE LCL
WATERS FRIDAY WITH INCREASING NW-N WINDS LATE IN THE DAY. ADVISORY
CONDITIONS EXPECTED FRI NIGHT INTO SATURDAY WITH NORTHERLY WINDS
INCREASING TO 20-25 KNOTS AND GUSTY.
&&
.PRELIMINARY POINT TEMPS...
DAB 66 75 67 81 / 10 30 20 30
MCO 66 81 68 84 / 10 20 20 30
MLB 67 81 69 82 / 10 20 20 20
VRB 67 82 69 83 / 10 20 20 20
LEE 68 78 67 82 / 10 30 20 30
SFB 66 79 68 83 / 10 30 20 30
ORL 66 80 68 83 / 10 30 20 30
FPR 68 82 69 83 / 10 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
257 PM EST MON DEC 14 2015
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND
LIFTS UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE
ZONAL PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE
NORTHERN STREAM FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY
PIVOTING TO THE NORTHEAST INTO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS
LIFTING THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL
THE WAY SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A
DEEP SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS
FRONT AND INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER
ONGOING FROM THE GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE
FLORIDA BIG BEND REGION.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA...HOWEVER A GLANCE AT THE 12Z KTBW SOUNDING
PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED SINCE SUNDAY. THE
SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL BIG BEND REGION AND
NORTHEAST GULF.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT. EVEN WITH PLENTY OF CLOUDS...THERE ARE ALSO
PLENTY OF SUNNY BREAKS RESULTING IN ANOTHER WELL ABOVE AVERAGE
DAY IN TERMS OF TEMPERATURE. THE LOW LEVEL POTENTIAL OF THE
ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH 850MB
TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR MID-
DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C TEMPERATURE
AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW JUST HOW
ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE 12Z KTBW
SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL OVER THE
90TH PERCENTILE FOR MID- DECEMBER)...AND THE 500MB TEMPERATURE WAS
MEASURED AT -3.1C. THIS VALUE TIES THE SECOND WARMEST EVER 500MB
TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER TIME...-2.1C WAS
OBSERVED ON DECEMBER 7TH. VERY IMPRESSIVE VALUES INDEED.
TEMPERATURES ARE CURRENTLY PEAKING IN THE LOW/MID 80S AWAY FROM
THE IMMEDIATE COAST. WIND HAVE COME AROUND TO THE SOUTH...WITH A
SLIGHT ONSHORE COMPONENT AT THE COAST..AND THIS ONSHORE COMPONENT
OFF THE "RELATIVELY" COOLER SHELF WATERS SHOULD CONTINUE TO KEEP
TEMPS AT THE BEACHES DOWN IN THE MID/UPPER 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...A FEW WDLY SCT SHOWERS WILL
BE POSSIBLE THROUGH EARLY EVENING ACROSS MAINLY THE INTERIOR
ZONES THIS LATE AFTERNOON/EARLY EVENING...BUT COVERAGE WILL BE
SPARSE AT BEST AND BARELY WORTH MENTION IN THE FORECAST. WE DO
HAVE A BAND OF SHOWERS APPROACHING THE NATURE COAST FROM THE
WEST...BUT PROGRESS IS VERY SLOW AS THE FRONTAL MOVEMENT SLOWS.
ALSO...ALL THE SYNOPTIC FORCING FOR LIFT ASSOCIATED WITH THE
PARENT SYSTEM HAS EXITED WELL NORTH OF THE REGION. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED SHOWER
ACTIVITY AS THE FRONT MOVES EAST THIS EVENING.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE
FLORIDA BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING.
THIS IS A FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING
NORTHWARD AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM
THE WARMTH AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW
TEMPERATURES TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER
60S FOR THE COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST
HOLDING IN THE LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND
THE FRONT SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. FORECAST WILL SHOW CHANCE/LIKELY POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THE NATURE COAST ZONES...WITH
ISOLATED SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY
DAWN.
LAST FEW RUNS OF THE SREF MEMBERS CONTINUE TO POINT TO A HIGHER
POTENTIAL FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT
INTO TUESDAY MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD
BETTER CHANCES FOR A LOW IFR STRATUS EVENT...BUT LIKELY TO SEE
SOME DENSE FOG IN A FEW SPOTS...ESPECIALLY SOUTH OF ANY SHOWER
ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. OVER
THE SOUTHERN INTERIOR ZONES...ENOUGH DIURNAL INSTABILITY WILL
LIKELY EXIST TO FORCE A FEW ISOLATED SHOWERS AFTER 18Z...BUT WILL
KEEP RAIN CHANCES AT 20% OR LESS.
DUE TO MORE CLOUDS AND OCCASIONAL SHOWERS...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST...SO A FEW TICKS OF LIGHTNING CAN NOT
BE RULED OUT...AND HAVE ADDED ISOLATED STORMS TO THE GRIDS.
&&
.LONG TERM (TUESDAY NIGHT-MONDAY)...
FOR THE MIDDLE PART OF NEXT WEEK...AN UPPER-LEVEL LOW WILL SHIFT
EASTWARD THROUGH THE CENTRAL PART OF THE COUNTRY WITH THE UPPER
RIDGE OVER THE ATLANTIC AND FLORIDA BEING SUPPRESSED FURTHER. AT THE
SURFACE...A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY ACROSS THE
NORTHERN PART OF THE PENINSULA AND WILL SHIFT NORTHWARD AS A WARM
FRONT ON WEDNESDAY. THIS SETUP WILL KEEP THE BEST RAIN CHANCES
GENERALLY NORTH OF THE TAMPA BAY AREA.
A SURFACE LOW WILL DEVELOP ALONG THE NORTHERN GULF COAST REGION
WEDNESDAY NIGHT AND SHIFT NORTHEASTWARD THROUGH THURSDAY...WITH A
STRONGER COLD FRONT APPROACHING THE BIG BEND REGION BY THE END OF
THE DAY. RAIN CHANCES WILL REALLY BEGIN TO INCREASE FOR THE NORTHERN
HALF OF THE FORECAST AREA THURSDAY AFTERNOON. THIS FRONT WILL BE
ABLE TO CLEAR THE AREA BY THE END OF THE DAY ON FRIDAY AS THE UPPER
TROUGH AXIS SWINGS TOWARD THE EAST COAST. THE FORECAST CURRENTLY
CALLS FOR LIKELY POPS FOR THE AREA THURSDAY NIGHT AND THROUGH FRIDAY
AS THE FRONT SHIFTS SOUTHWARD WITH CONDITIONS CLEARING OUT RATHER
QUICKLY FRIDAY NIGHT. HIGH PRESSURE WILL BEGIN TO BUILD OVER THE
SOUTHEAST AND REMAIN IN PLACE THROUGH THE WEEKEND. A MUCH COOLER AND
DRIER AIR MASS WILL FILTER INTO THE REGION FOR THIS PERIOD...WITH
TEMPERATURES FALLING WELL BELOW NORMAL FOR SATURDAY ESPECIALLY. THE
SURFACE HIGH WILL SHIFT EASTWARD INTO THE BEGINNING OF NEXT
WEEK...WITH A FAIRLY QUICK AIR MASS MODIFICATION GIVING US HIGHS
BACK TO AROUND NORMAL.
&&
.AVIATION...
GENERAL VFR CONDITIONS OR HIGH END MVFR OBSERVED ACROSS WEST-
CENTRAL AND SOUTHWEST FLORIDA THIS AFTERNOON AND EARLY EVENING.
POTENTIAL CONTINUE TO LOOK HIGH FOR ANOTHER WIDESPREAD LOWER
STRATUS/PATCHY FOG EVENT FOR THE SECOND HALF OF TONIGHT THROUGH
MID TUESDAY MORNING. HAVE INCLUDED LOW END MVFR MENTION AFTER 06Z
FOR ALL TAF SITES...AND MAY NEED TO DECREASE TO IFR FOR SOME SITES
WITH FUTURE TAF UPDATES. SHOULD SEE A RETURN TO GENERAL VFR OR
HIGH END MVFR CONDITIONS BY MIDDAY ON TUESDAY.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION THIS EVENING
AND STALL ACROSS THE NORTHEAST GULF OF MEXICO LATE TONIGHT AND
TUESDAY. WINDS WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF
THIS FRONT...BUT MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE
LEVY/CITRUS COUNTY COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT
BACK NORTH ON WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW
ACROSS THE EASTERN GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY
REMAIN BELOW HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.FIRE WEATHER...
A WEAK FRONT WILL STALL ACROSS THE NORTHERN FLORIDA PENINSULA
TUESDAY AND THEN LIFT BACK NORTH INTO GEORGIA DURING WEDNESDAY.
SCATTERED SHOWERS ARE EXPECTED WITH THIS FRONT ON TUESDAY...MAINLY
ALONG AND NORTH OF THE I-4 CORRIDOR. ABUNDANT LOW LEVEL MOISTURE
WILL KEEP RELATIVE HUMIDITY WELL ABOVE CRITICAL LEVELS THE NEXT
SEVERAL DAYS...AND NO SIGNIFICANT FIRE WEATHER CONCERNS ARE
ANTICIPATED. A STRONGER COLD FRONT IS EXPECTED TO CROSS THE REGION
DURING FRIDAY WITH A MUCH COOLER AND DRIER AIRMASS ARRIVING FOR
THE UPCOMING WEEKEND.
FOG POTENTIAL...WIDESPREAD LOW CLOUDS AND AREAS OF FOG ARE
ANTICIPATED TO DEVELOP OVERNIGHT...LINGERING THROUGH THE MIDDLE OF
THE MORNING TUESDAY. PATCHY GROUND FOG IS POSSIBLE LATE TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 77 68 81 / 10 30 20 20
FMY 69 83 69 85 / 10 10 10 10
GIF 67 80 67 83 / 10 30 10 30
SRQ 68 77 67 80 / 10 20 10 10
BKV 68 78 66 83 / 30 50 20 20
SPG 70 78 69 81 / 10 30 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR
COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
945 AM EST MON DEC 14 2015
.DISCUSSION...
...NEAR RECORD WARMTH FOR TODAY...
MORNING RAOBS/USAF PROFILER DATA SHOWING A BRISK SRLY FLOW THRU THE
H100-H70 LYR AHEAD OF A COLD FRONT NOSING ITS WAY THRU THE DEEP
SOUTH. WINDS WILL GRADUALLY VEER TO THE SW THRU THE DAY AS THE FRONT
CONTINUES ITS SLOW ADVANCE...THOUGH A DEEP HI PRES RIDGE CENTERED SW
OF BERMUDA WILL FORCE THE FRONT TO STALL AS IT WORKS ITS WAY INTO
THE BIG BEND REGION. RAP ANALYSIS SHOWS MINIMAL MID LVL VORTICITY
AND UPR LVL DIVERGENCE AHEAD OF THE FRONT...H50 TEMPS BTWN -3/-4C
WITH MID LVL LAPSE RATES RUNNING BLO 5.0C/KM. MOISTURE IS SOMEWHAT
LIMITED WITH PWAT VALUES ARND 1.5" AT KTBW/KXMR...DECREASING TO
ARND 1.3" AT KMFL. RAP ANALYSIS CONFIRMS THIS WITH MEAN RH VALUES
AOB 70PCT THRU THE H100-H70 LYR ACRS CENTRAL/S FL.
THE DVLPG SW FLOW REGIME IS ONE OF THE WARMEST FOR EAST CENTRAL FL.
MAX TEMPS SUN AFTN WERE IN THE L80S AREAWIDE...AND WHILE INCREASING
UPR LVL CLOUDS AHEAD OF THE FRONT MAY IMPEDE SFC HEATING...NEAR
RECORD TEMPS ARE EXPECTED THIS AFTN WITH READINGS ARND 15F ABV AVG.
GIVEN THE DECREASING MOISTURE TO THE SOUTH...THE TEPID MID LVL
TEMPS...AND LIMITED DYNAMIC SUPPORT...WILL KEEP POPS AOB 20PCT.
&&
.AVIATION...THRU 15/12Z
SFC WNDS: THRU 14/22Z...S/SW 9-13KTS WITH OCNL G20KTS. BTWN 14/22Z-
15/02Z...BCMG S/SW 2-4KTS.
VSBY/WX/CIGS: THRU 15/06Z...PREVAILING VFR WITH CIGS BTWN FL040-
060...BRIEF ISOLD MVFR SHRAS S OF KISM-KDAB. AFT 15/06Z...N OF KISM-
KTIX MVFR CIGS BTWN FL010-020 LCL LIFR CIGS BLO FL006 WITH VSBYS BLO
1SM IN BR/FG. S OF KISM-KTIX CIGS AOA FL120 AREAS MVFR VSBYS IN
BR.
&&
.MARINE...
LATEST SFC/OCEAN OBS SHOW A SIGNIFICANT DECREASE IN WINDS ACRS THE
REGION OVER THE PAST 12HRS...EVEN AS RAOB/PROFILER DATA DISPLAY A
SOLID 20-25KTS OF SRLY FLOW THRU 10KFT. SEAS AT BUOY009 HAVE
SUBSIDED TO ARND 6FT...MAINLY IN AN ERLY SWELL. BUOY010 IS HOLDING
15-20KTS...BUT ALSO SHOWING A DIMINISHING SEA TREND OVER THE PAST
SVRL HRS.
GENTLE TO MODERATE WINDS EXPECTED TO VEER TO SW THRU THE AFTN AS THE
FRONTAL TROF BEGINS TO STALL OVER THE PANHANDLE. WHILE CONDITIONS
ARE EXPECTED TO IMPROVE...THE OPPOSING WRLY WIND/ERLY SWELL
COMPONENTS MAY GENERATE POCKETS OF ROUGH SEAS. WILL ALLOW THE SCA TO
EXPIRE AT 15Z BUT WILL MAINTAIN CAUTIONARY STATEMENTS FOR THE
GULFSTREAM WATERS.
&&
.CLIMATE...
NEAR RECORD/RECORD HIGHS POSSIBLE TODAY...
LOC DATE HI-MAX
DAB 14-DEC 85 1991...FORECAST 84
MCO 14-DEC 86 1972...FORECAST 85
MLB 14-DEC 85 1961...FORECAST 84
VRB 14-DEC 85 1991...FORECAST 84
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
931 AM EST MON DEC 14 2015
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND LIFTS
UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE ZONAL
PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE NORTHERN STREAM
FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY PIVOTING TO THE
NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS LIFTING
THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL THE WAY
SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A DEEP
SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS FRONT AND
INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER ONGOING FROM THE
GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE FLORIDA PANHANDLE.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA FOR TODAY...HOWEVER A GLANCE AT THE 12Z KTBW
SOUNDING PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED IN THE PAST 24 HOURS.
THE SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL PANHANDLE/NORTH-CENTRAL
GULF. THE SOUTHERLY FLOW AND ABUNDANT LOW LEVEL MOISTURE KEPT
TEMPERATURES EARLY THIS MORNING WELL ABOVE NORMAL...STARTING THE DAY
OUT WITH MOST LOCATIONS IN THE 70S! QUITE A BIT OF LOW STRATUS
DEVELOPMENT EARLY THIS MORNING WITH ALL THE AVAILABLE MOISTURE UNDER
THE UPPER RIDGE. WILL SEE MOSTLY CLOUDY SKIES WITH BREAKS OF SUN
GIVE WAY TO A MIX OF SUN AND CLOUDS THROUGH MIDDAY. REGIONAL RADARS
ARE QUIET AROUND THE PENINSULA...WITH THE NEAREST ORGANIZED
RAINFALL LOCATED ALONG THE FRONT OVER THE FL PANHANDLE.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT THROUGHOUT THE DAY. EVEN WITH PLENTY OF CLOUDS
TODAY...LOOKING FOR ENOUGH SUNNY BREAKS TO RESULT IN ANOTHER WELL
ABOVE AVERAGE DAY IN TERMS OF TEMPERATURE AND HUMIDITY. NOT HARD
TO ACCOMPLISH THAT WHEN YOUR 8AM TEMPERATURES ARE ALREADY
SURPASSING YOUR NORMAL HIGHS FOR THE DATE. THE LOW LEVEL POTENTIAL
OF THE ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH
850MB TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR
MID- DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C
TEMPERATURE AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW
JUST HOW ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE
12Z KTBW SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL
OVER THE 90TH PERCENTILE FOR MID-DECEMBER)...AND THE 500MB
TEMPERATURE WAS MEASURED AT -3.1C. THIS VALUE TIES THE SECOND
WARMEST EVER 500MB TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER
TIME...-2.1C WAS OBSERVED ON DECEMBER 7TH. VERY IMPRESSIVE VALUES
INDEED. GIVEN HOW WARM THE COLUMN IS...EVEN BRIEF PEAKS OF THE SUN
WILL QUICKLY BOOST OUR TEMPERATURES INTO THE LOW/MID 80S AWAY FROM
THE IMMEDIATE COAST. WIND HAVE ALREADY COME AROUND TO THE
SOUTH...AND SHOULD DEVELOP AN ONSHORE COMPONENT DURING THE
AFTERNOON. THIS ONSHORE COMPONENT OFF THE "RELATIVELY" COOLER SHELF
WATERS SHOULD HELP KEEP TEMPS AT THE BEACHES DOWN IN THE 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...AN ISOLATED SHOWER OR TWO IS
POSSIBLE ACROSS MAINLY THE INTERIOR ZONES THIS AFTERNOON/EARLY
EVENING...BUT COVERAGE WILL BE SPARSE AT BEST AND BARELY WORTH
MENTION IN THE FORECAST. WE DO HAVE A BAND OF SHOWERS APPROACHING
THE NATURE COAST FROM THE WEST...BUT PROGRESS IS VERY SLOW AS THE
FRONTAL MOVEMENT SLOWS. ALSO...ALL THE SYNOPTIC FORCING FOR LIFT
ASSOCIATED WITH THE PARENT SYSTEM IS QUICKLY EXITING WELL NORTH OF
THE REGION AND WILL BE COMPLETELY GONE BY LATER TODAY. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED AND
LESS COVERAGE OF SHOWERS AS THE FRONT MOVES EAST LATER TODAY. ONLY
HAVE A 20% POP OVER LEVY COUNTY LATE THIS AFTERNOON INTO THE
EVENING FOR THESE REASONS.
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE FLORIDA
BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING. THIS IS A
FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING NORTHWARD
AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM THE WARMTH
AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW TEMPERATURES
TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER 60S FOR THE
COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST HOLDING IN THE
LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND THE FRONT
SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. WOULD EXPECT TO KEEP AT LEAST CHANCE POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THESE NORTHERN ZONES...WITH ISOLATED
SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY DAWN.
LAST FEW RUNS OF THE SREF MEMBERS HAVE POINTED TO A HIGH POTENTIAL
FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT INTO TUESDAY
MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD BETTER CHANCES FOR A
LOW IFR STRATUS EVENT...BUT LIKELY TO SEE SOME DENSE FOG IN A FEW
SPOTS...ESPECIALLY SOUTH OF ANY SHOWER ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. WITH
MORE CLOUDS AND OCCASIONAL SHOWER POTENTIAL...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST TOMORROW...SO A FEW TICKS OF LIGHTNING
CAN NOT BE RULED OUT...AND WILL ADD ISOLATED STORMS TO THE GRIDS.
&&
.AVIATION...
QUITE A BIT OF LOWER STRATUS AND RESULTING IFR/MVFR CONDITIONS
ACROSS THE REGION THIS MORNING. THE STRATUS IS FAIRLY THIN...SO
SHOULD BEGIN TO SEE IMPROVEMENT AFTER 15-16Z...WITH GENERAL VFR
CONDITIONS OR HIGH END MVFR THROUGH THE AFTERNOON/EVENING.
POTENTIAL FOR ANOTHER WIDESPREAD LOWER STRATUS/FOG EVENT IS
INCREASING FOR THE SECOND HALF OF TONIGHT AND TUESDAY MORNING.
WILL CONTINUE TO MONITOR GUIDANCE TRENDS...BUT LIKELY AT LEAST
MVFR RESTRICTIONS WILL BE ADDED TO THE 18Z TAFS AFTER 06Z TUESDAY
MORNING.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION TODAY AND STALL
ACROSS THE NORTHEAST GULF OF MEXICO TONIGHT AND TUESDAY. WINDS
WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF THIS FRONT...BUT
MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE LEVY/CITRUS COUNTY
COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT BACK NORTH ON
WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW ACROSS THE EASTERN
GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 80 69 80 67 / 10 20 30 10
FMY 83 69 84 69 / 10 10 20 10
GIF 83 67 82 68 / 10 10 20 10
SRQ 79 68 80 68 / 10 10 20 10
BKV 82 67 80 66 / 10 20 50 20
SPG 79 69 79 69 / 10 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
917 AM EST MON DEC 14 2015
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND LIFTS
UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE ZONAL
PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE NORTHERN STREAM
FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY PIVOTING TO THE
NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS LIFTING
THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL THE WAY
SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A DEEP
SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS FRONT AND
INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER ONGOING FROM THE
GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE FLORIDA PANHANDLE.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA FOR TODAY...HOWEVER A GLANCE AT THE 12Z KTBW
SOUNDING PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED IN THE PAST 24 HOURS.
THE SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL PANHANDLE/NORTH-CENTRAL
GULF. THE SOUTHERLY FLOW AND ABUNDANT LOW LEVEL MOISTURE KEPT
TEMPERATURES EARLY THIS MORNING WELL ABOVE NORMAL...STARTING THE DAY
OUT WITH MOST LOCATIONS IN THE 70S! QUITE A BIT OF LOW STRATUS
DEVELOPMENT EARLY THIS MORNING WITH ALL THE AVAILABLE MOISTURE UNDER
THE UPPER RIDGE. WILL SEE MOSTLY CLOUDY SKIES WITH BREAKS OF SUN
GIVE WAY TO A MIX OF SUN AND CLOUDS THROUGH MIDDAY. REGIONAL RADARS
ARE QUIET AROUND THE PENINSULA...WITH THE NEAREST ORGANIZED
RAINFALL LOCATED ALONG THE FRONT OVER THE FL PANHANDLE.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT THROUGHOUT THE DAY. EVEN WITH PLENTY OF CLOUDS
TODAY...LOOKING FOR ENOUGH SUNNY BREAKS TO RESULT IN ANOTHER WELL
ABOVE AVERAGE DAY IN TERMS OF TEMPERATURE AND HUMIDITY. NOT HARD
TO ACCOMPLISH THAT WHEN YOUR 8AM TEMPERATURES ARE ALREADY
SURPASSING YOUR NORMAL HIGHS FOR THE DATE. THE LOW LEVEL POTENTIAL
OF THE ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH
850MB TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR
MID- DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C
TEMPERATURE AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW
JUST HOW ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE
12Z KTBW SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL
OVER THE 90TH PERCENTILE FOR MID-DECEMBER)...AND THE 500MB
TEMPERATURE WAS MEASURED AT -3.1C. THIS VALUE TIES THE WARMEST
EVER 500MB TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER
TIME...-3.1C WAS OBSERVED ON DECEMBER 7TH...MAKING THIS THE LATEST
SUCH A VALUE HAS EVEN OCCURRED. VERY IMPRESSIVE INDEED. GIVEN HOW
WARM THE COLUMN IS...EVEN BRIEF PEAKS OF THE SUN WILL QUICKLY
BOOST OUR TEMPERATURES INTO THE LOW/MID 80S AWAY FROM THE
IMMEDIATE COAST. WIND HAVE ALREADY COME AROUND TO THE SOUTH...AND
SHOULD DEVELOP AN ONSHORE COMPONENT DURING THE AFTERNOON. THIS
ONSHORE COMPONENT OFF THE "RELATIVELY" COOLER SHELF WATERS SHOULD
HELP KEEP TEMPS AT THE BEACHES DOWN IN THE 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...AN ISOLATED SHOWER OR TWO IS
POSSIBLE ACROSS MAINLY THE INTERIOR ZONES THIS AFTERNOON/EARLY
EVENING...BUT COVERAGE WILL BE SPARSE AT BEST AND BARELY WORTH
MENTION IN THE FORECAST. WE DO HAVE A BAND OF SHOWERS APPROACHING
THE NATURE COAST FROM THE WEST...BUT PROGRESS IS VERY SLOW AS THE
FRONTAL MOVEMENT SLOWS. ALSO...ALL THE SYNOPTIC FORCING FOR LIFT
ASSOCIATED WITH THE PARENT SYSTEM IS QUICKLY EXITING WELL NORTH OF
THE REGION AND WILL BE COMPLETELY GONE BY LATER TODAY. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED AND
LESS COVERAGE OF SHOWERS AS THE FRONT MOVES EAST LATER TODAY. ONLY
HAVE A 20% POP OVER LEVY COUNTY LATE THIS AFTERNOON INTO THE
EVENING FOR THESE REASONS.
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE FLORIDA
BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING. THIS IS A
FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING NORTHWARD
AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM THE WARMTH
AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW TEMPERATURES
TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER 60S FOR THE
COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST HOLDING IN THE
LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND THE FRONT
SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. WOULD EXPECT TO KEEP AT LEAST CHANCE POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THESE NORTHERN ZONES...WITH ISOLATED
SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY DAWN.
LAST FEW RUNS OF THE SREF MEMBERS HAVE POINTED TO A HIGH POTENTIAL
FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT INTO TUESDAY
MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD BETTER CHANCES FOR A
LOW IFR STRATUS EVENT...BUT LIKELY TO SEE SOME DENSE FOG IN A FEW
SPOTS...ESPECIALLY SOUTH OF ANY SHOWER ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. WITH
MORE CLOUDS AND OCCASIONAL SHOWER POTENTIAL...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST TOMORROW...SO A FEW TICKS OF LIGHTNING
CAN NOT BE RULED OUT...AND WILL ADD ISOLATED STORMS TO THE GRIDS.
&&
.AVIATION...
QUITE A BIT OF LOWER STRATUS AND RESULTING IFR/MVFR CONDITIONS
ACROSS THE REGION THIS MORNING. THE STRATUS IS FAIRLY THIN...SO
SHOULD BEGIN TO SEE IMPROVEMENT AFTER 15-16Z...WITH GENERAL VFR
CONDITIONS OR HIGH END MVFR THROUGH THE AFTERNOON/EVENING.
POTENTIAL FOR ANOTHER WIDESPREAD LOWER STRATUS/FOG EVENT IS
INCREASING FOR THE SECOND HALF OF TONIGHT AND TUESDAY MORNING.
WILL CONTINUE TO MONITOR GUIDANCE TRENDS...BUT LIKELY AT LEAST
MVFR RESTRICTIONS WILL BE ADDED TO THE 18Z TAFS AFTER 06Z TUESDAY
MORNING.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION TODAY AND STALL
ACROSS THE NORTHEAST GULF OF MEXICO TONIGHT AND TUESDAY. WINDS
WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF THIS FRONT...BUT
MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE LEVY/CITRUS COUNTY
COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT BACK NORTH ON
WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW ACROSS THE EASTERN
GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 80 69 80 67 / 10 20 30 10
FMY 83 69 84 69 / 10 10 20 10
GIF 83 67 82 68 / 10 10 20 10
SRQ 79 68 80 68 / 10 10 20 10
BKV 82 67 80 66 / 10 20 50 20
SPG 79 69 79 69 / 10 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1042 PM EST TUE DEC 15 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE AREA INTO EARLY WEDNESDAY.
A SLOW MOVING FRONTAL SYSTEM WILL IMPACT THE AREA LATE WEDNESDAY
THROUGH EARLY FRIDAY. COLD HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION
TONIGHT AS IT SHIFTS ACROSS THE CENTRAL APPALACHIANS AND INTO THE
MID-ATLANTIC REGION. AS THIS OCCURS...RIDGING WILL CONTINUE TO
STRENGTHEN ALOFT.
TEMPERATURES CONTINUE TO FALL QUICKLY UNDER CLEAR SKIES AND A
DECOUPLED ATMOSPHERE. EXCELLENT RADIATIONAL COOLING SHOULD
CONTINUE THROUGH MUCH OF THE NIGHT ACROSS A LARGE PORTION OF THE
AREA. THE EXCEPTION IS ACROSS PARTS OF FAR SOUTHEAST GEORGIA
WHERE WEAK ISENTROPIC ASCENT ATOP A STATIONARY FRONT NOT TOO FAR
OFFSHORE COULD ALLOW SOME LATE NIGHT STRATOCUMULUS TO DEVELOP AND
SLOW THE DOWNWARD TEMPERATURE PROGRESSION. OVERALL...EXPECT A
RATHER LARGE NW-SE TEMPERATURE GRADIENT...WITH LOWS RANGING FROM
THE LOWER AND MIDDLE 40S NORTH AND WEST TO LOWER-MIDDLE 50S AT
AND NEAR THE COAST...INCLUDING DOWNTOWN CHARLESTON.
RADIATION FOG SEEMS MORE PROBABLE OVERNIGHT WITH FOG STABILITY
INDICES IN THE SINGLE DIGITS AND TEENS...AND WITH SOME HIGHER
RESOLUTION MESOSCALE MODELS SUCH AS THE RAP AND HRRR INDICATING
THE POTENTIAL FOR REDUCED VISIBILITIES AS WELL. HOWEVER...GIVEN
THAT THE LOWEST CONDENSATION PRESSURE DEFICITS REMAIN JUST TO OUR
NORTH/NW IT SHOULDN/T BE TOO WIDESPREAD AND/OR DENSE. WILL
MAINTAIN PATCHY FOG IN THE FORECAST FOR NOW.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEAK SURFACE HIGH PRESSURE WILL PERSIST ON WEDNESDAY WHILE THE
FLOW ALOFT GRADUALLY BACKS AND STRENGTHENS IN RESPONSE TO A
DIGGING UPPER TROUGH TO THE WEST. WEAK MOIST ISENTROPIC ASCENT
WILL DEVELOP DURING THE AFTERNOON...RESULTING IN A GRADUAL
INCREASE IN CLOUD COVER FROM SOUTH TO NORTH AND LOW-END CHANCES OF
RAIN LATE IN THE DAY. FAIRLY GOOD INSOLATION IN ADVANCE OF THE
CLOUDS AND A WARM AIRMASS WILL SUPPORT HIGH TEMPS IN THE MIDDLE
70S.
A STRENGTHENING SOUTHERLY LOW-LEVEL JET WEDNESDAY NIGHT INTO
THURSDAY WILL ALLOW A WARM FRONT TO LIFT NORTH THROUGH THE AREA
AND SPREAD A MOIST AIRMASS INTO THE SOUTHEAST STATES AHEAD OF THE
COLD FRONT. PWATS EXPECTED TO RANGE FROM 1.75" TO 2" BY MIDDAY
THURSDAY. THERE SHOULD BE A FEW RAIN SHOWERS MOVING THROUGH IN
ASSOCIATION WITH THE WARM FRONT...BUT THE BEST FORCING ARRIVES
LATER ON THURSDAY. FRONTAL FORCING COMBINED WITH MODEST UPPER JET
DIVERGENCE IN CONCERT WITH SIGNIFICANTLY ABOVE-NORMAL PWATS SHOULD
ALLOW FOR WIDESPREAD SHOWERS TO DEVELOP THURSDAY INTO THURSDAY
NIGHT. SURFACE-BASED CAPES OF 500-1000 J/KG AND LIFTED INDICES -2
TO -4C THURSDAY AFTERNOON INDICATE AT LEAST ISOLATED THUNDERSTORM
POTENTIAL. LOW-LEVEL WINDS WILL BE QUITE STRONG ON THURSDAY WITH
925 MB WINDS AROUND 40 KT FROM THE SSW. POCKETS OF MODERATE
INSTABILITY AND STRONG WIND FIELDS MAY SUPPORT AN ISOLATED RISK
FOR A STRONG/SEVERE STORM LATER IN THE DAY. AT A MINIMUM WE EXPECT
BREEZY CONDITIONS AND HIGH TEMPS IN THE MID TO UPPER 70S.
MODELS HAVE SLOWED DOWN THE FRONTAL PROGRESSION SLIGHTLY...KEEPING
A FAIRLY GOOD COVERAGE OF SHOWERS OVER THE AREA THROUGH THURSDAY
NIGHT. IMPROVING CONDITIONS ANTICIPATED FRIDAY WITH CLEARING SKIES
BY AFTERNOON. LATE DAY COLD ADVECTION WILL KEEP TEMPS IN THE UPPER
50S FAR INLAND BUT WE BUMPED HIGHS INTO THE MID 60S NEAR THE COAST
WHERE THE WARM ADVECTION WILL PERSIST THE LONGEST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SURFACE HIGH PRESSURE ACROSS THE CENTRAL U.S. FRIDAY NIGHT WILL MOVE
OVER OR JUST NORTH OF OUR AREA SUNDAY...THEN MOVE OUT TO SEA ON
MONDAY. COLD NORTHWEST FLOW RESULTING FROM THIS HIGH WILL LEAD TO
MUCH COLDER TEMPERATURES THAN THE AREA HAS BEEN EXPERIENCING.
SATURDAY HIGHS WILL BE IN THE MID 50S WHILE SUNDAY MORNING LOWS WILL
BE IN THE LOW TO MID 30S...ABOUT 5 DEGREES BELOW NORMAL.
TEMPERATURES SHOULD BEGIN MODERATING SUNDAY AND MONDAY AS HEIGHTS
BUILD AND FLOW TURNS SOUTHWESTERLY. BUT A COASTAL TROUGH MAY ALSO
DEVELOP BOTH DAYS...LEADING TO POSSIBLY SOME SHOWERS ALONG THE
IMMEDIATE COAST.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THERE IS A POTENTIAL FOR MAINLY PATCHY SHALLOW GROUND FOG TO
DEVELOP IN THE 07-13Z TIME FRAME AND AS A RESULT VISIBILITIES
RESTRICTIONS ARE POSSIBLE. THERE APPEARS TO BE A SLIGHTLY GREATER
POTENTIAL FOR FOG AT KCHS SO HAVE INDICATED MVFR VISIBILITIES
THERE...BUT HELD VISIBILITIES TO 6SM AT KSAV FOR THE TIME BEING.
OTHERWISE...VFR CONDITIONS WILL PREVAIL AT THE TERMINALS.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS EXPECTED
WEDNESDAY THROUGH FRIDAY MORNING AS A FRONTAL SYSTEM AFFECTS THE
AREA.
&&
.MARINE...
TONIGHT...A WEAK PRESSURE PATTERN WILL INFLUENCE CONDITIONS
ACROSS THE ATLANTIC AND IN THE CHARLESTON AND SAVANNAH HARBORS.
WINDS WILL STEADILY CLOCK AROUND TO THE WEST AT LESS THAN 5 OR 10
KT TONIGHT. THE NOSE OF HIGH PRESSURE ARRIVING FROM THE NORTH LATE
WILL CAUSE WINDS TO VEER FURTHER TO THE NORTH/NE BY DAYBREAK. NOT
MUCH WAVE ACTION IN GENERAL...ALTHOUGH BUOY SITES IN AND NEAR THE
LOCAL WATERS SHOWING A VERY SMALL 12-14 SECOND SWELL FROM THE
EAST/NE THAT WILL CONTINUE.
WEDNESDAY AND WEDNESDAY NIGHT WILL FEATURE FAIRLY LIGHTLY WINDS
AND MARGINAL SEAS DUE TO HIGH PRESSURE IN PLACE. A STRONG LOW-
LEVEL JET DEVELOPS ON THURSDAY AHEAD OF A COLD FRONT. WE COULD SEE
GUSTS APPROACHING SMALL CRAFT CRITERIA OVER THE OUTER WATERS OR
PERHAPS IN CHARLESTON HARBOR. A BETTER CHANCE FOR SMALL CRAFT
CONDITIONS WILL SETUP FRIDAY INTO FRIDAY NIGHT AS STRONG COLD
ADVECTION BLOWS OVER THE WATERS BEHIND THE COLD FRONT. BROAD HIGH
PRESSURE OVER THE WEEKEND WILL YIELD DIMINISHING WIND AND SEA
CONDITIONS.
SEA FOG...THERE IS AGAIN THE POTENTIAL FOR SEA FOG LATE WEDNESDAY
NIGHT THROUGH THURSDAY EVENING AS A WARM AND HUMID AIR MASS MOVES
IN OVER THE COOLER SHELF WATERS.
&&
.CLIMATE...
THERE IS A GOOD CHANCE THAT RAINFALL AT THE END OF THIS WEEK WILL
PUSH THE YEARLY RAINFALL TOTAL AT THE CHARLESTON INTERNATIONAL
AIRPORT /KCHS/ ABOVE THE ALL TIME YEARLY PRECIPITATION RECORD. THE
CURRENT RECORD IS 72.99 INCHES THAT WAS SET IN 1964. RECORDS FOR
THE CHARLESTON INTERNATIONAL AIRPORT DATE BACK TO 1938.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JAQ
SHORT TERM...JRL
LONG TERM...
AVIATION...JAQ
MARINE...JAQ/JRL
CLIMATE...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1001 PM EST TUE DEC 15 2015
.SYNOPSIS...
DRY HIGH PRESSURE WILL BE OVER THE REGION THROUGH WEDNESDAY
AFTERNOON. A STRONG COLD FRONT WILL CROSS THE AREA THURSDAY
BRINGING RAIN TO THE AREA. MUCH COOLER HIGH PRESSURE WILL
OVERSPREAD THE REGION BEHIND THE FRONT FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
RIDGING AT THE SURFACE AND ALOFT WILL REMAIN IN CONTROL THROUGH
TONIGHT. SATELLITE TRENDS SUPPORT CLEAR SKIES. STRONG NET
RADIATIONAL COOLING WILL OCCUR. WE LEANED TOWARD THE LOWER
TEMPERATURE GUIDANCE. THE COOLING AND LOW-LEVEL MOISTURE SHOULD
HELP SUPPORT FOG AS INDICATED BY THE CROSSOVER TEMPERATURES AND
SOME OF THE NAM AND GFS MOS. THE HRRR ALSO INDICATED SCATTERED
AREAS OF FOG. THE FOG WILL LIKELY BE MAINLY CONFINED TO AREAS
NEAR BODIES OF WATER BECAUSE OF THE DRY AIR MASS. WE FORECASTED
PATCHY FOG DURING THE EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
THE UPPER-LEVEL RIDGE ALONG THE EAST COAST EARLY WEDNESDAY WILL
SHIFT EAST DURING THE AFTERNOON AS DEEP/SURFACE UPPER-LEVEL LOW
MOVES FROM THE NORTHERN PLAINS INTO THE GREAT LAKES/SOUTHERN
CANADA. THIS WILL RESULT IN INCREASING DEEP SOUTH/SOUTHWEST FLOW
ACROSS THE REGION LATE WEDNESDAY THROUGH THURSDAY. MOST OF
WEDNESDAY SHOULD BE DRY AS THE FOCUS FOR SHOWERS REMAINS SOUTH OF
THE AREA NEAR THE WARM FRONT IN GEORGIA AND MOISTURE REMAINS
SHALLOW. PRECIPITABLE WATER INCREASING WEDNESDAY NIGHT HOWEVER AS
WARM FRONT LIFTS NORTH AND ISENTROPIC LIFT INCREASES. EXPECT
MAINLY LIGHT RAIN SPREADING NORTHEAST MAINLY AFTER MIDNIGHT.
PRECIPITABLE WATER RISING TO WELL ABOVE NORMAL VALUES...1.5 TO
POSSIBLY 2 INCHES BY THURSDAY AS SOUTHERN PLAINS H5 SHORTWAVE
TROUGH MOVES NORTHEAST THROUGH THE MISSISSIPPI VALLEY. MODELS
SUGGEST WEAK SURFACE LOW OVER THE GULF COAST WILL LIFT TO THE
NORTHEAST AND SPREAD NUMEROUS SHOWERS/WITH CATEGORICAL POPS BY
AFTERNOON...INTO THE CAROLINAS/GEORGIA AS ISENTROPIC LIFT/MOISTURE
FLUX INCREASES...AIDED BY STRONG LOW-LEVEL JET. SREF SHOWS LARGE
SPREAD IN THE QPF GUIDANCE...ALTHOUGH MEAN NEAR 1 INCH FOR THE
CWA. SO SOME UNCERTAINTY IN PRECIPITATION AMOUNTS. NAM MODEL QPF
HIGHER THAN GFS. WITH WEAK INSTABILITY AND AREA IN WARM
SECTOR...SOME POTENTIAL FOR EMBEDDED THUNDERSTORMS...WHICH COULD
RESULT IN ENHANCED LOCAL RAINFALL GIVEN THE FACT THAT H85 SOUTHWEST
JET WILL BE NEAR 50 KTS. BUT MODELS SUGGEST HIGHER QPF IN THE
UPSTATE AND CAROLINA MOUNTAINS WHERE UPPER-LEVEL ENERGY SHOULD BE
STRONGER. THE COLD FRONT IS FORECAST TO MOVE THROUGH THE AREA
THURSDAY NIGHT...MAINLY AFTER 06Z. SREF A LITTLE SLOWER SO WILL
HANG ON TO A LOW POP EARLY FRIDAY BUT EXPECT RAPIDLY IMPROVING
CONDITIONS AS COLD ADVECTION DEVELOPS.
TEMPERATURES DURING THIS PERIOD WILL REMAIN MILD AND ABOVE
NORMAL...ESPECIALLY WEDNESDAY NIGHT INTO THURSDAY AS LOWS
WEDNESDAY NIGHT ARE EXPECTED TO BE 20-25 DEGREES ABOVE NORMAL IN
THE UPPER 50S TO NEAR 60 DEGREES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
A COOLER AND DRIER AIR MASS WILL BUILD INTO THE REGION FRIDAY IN
THE WAKE OF THE COLD FRONT WITH GENERALLY WESTERLY WINDS AND SOME
SUNSHINE AS THE DEEP MOISTURE WILL HAVE SHIFTED EAST OF THE
FORECAST AREA. BREEZY CONDITIONS ARE EXPECTED FRIDAY WITH 25-30
KNOT H85 WINDS MIXING DOWN TOWARD THE SURFACE WITH DEEP MIXING
TAKING PLACE. THE UPPER-LEVEL TROUGH AXIS WILL STILL BE TO THE
WEST BUT WITH LITTLE MOISTURE TO WORK WITH DO NOT EXPECT ANY
ADDITIONAL PRECIPITATION OVER THE AREA FRIDAY.
THE TROUGH AXIS WILL CROSS THE AREA FRIDAY NIGHT AND THIS WILL
COINCIDE WITH THE COLDEST H85 TEMPERATURES AS A SECONDARY SURGE
OF COLD AIR MOVES INTO THE AREA. H85 TEMPS FALL TO AROUND -5C BY
SATURDAY MORNING AND WILL SUPPORT LOWS WELL INTO THE 30S FRIDAY
NIGHT. THE WEEKEND FEATURES MUCH COOLER WEATHER WITH TEMPERATURES
BELOW NORMAL AND MORE LIKE WHAT WE WOULD EXPECT FOR MID DECEMBER
WITH HIGHS IN THE LOWER TO MID 50S AND LOWS IN THE 20S TO LOWER
30S SATURDAY NIGHT AND SLIGHTLY WARMER SUNDAY NIGHT. A VERY DRY
AIR MASS AND STRONG SUBSIDENCE INVERSION NOTED ON FORECAST
SOUNDINGS WILL SUPPORT MOSTLY CLEAR SKIES AND RAIN-FREE
CONDITIONS THROUGH SUNDAY NIGHT.
A QUICK MOVING H5 SHORTWAVE TROUGH TRACKING NORTHEAST FROM THE
CENTRAL PLAINS TO THE GREAT LAKES WILL INDUCE WEAK SURFACE LOW
DEVELOPMENT OVER THE UPPER MIDWEST. LOW-LEVEL MOISTURE RETURN
FLOW AROUND THE SURFACE HIGH MOVING OFF THE CAROLINA COAST WILL
BRING INCREASED MOISTURE AND SOME RAINFALL TO THE TENNESSEE VALLEY
MONDAY WHICH WILL SHIFT EASTWARD. A DRY ATMOSPHERE IN PLACE WILL
BE TOO MUCH TO OVERCOME OVER THE FORECAST AREA SO WILL KEEP A DRY
FORECAST FOR MONDAY BUT HAVE A SLIGHT CHANCE OF SHOWERS TUESDAY.
EXPECT SLIGHTLY WARMING TEMPERATURES BECAUSE OF SOUTHERLY LOW-
LEVEL FLOW.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED TONIGHT WITH RESTRICTIONS POSSIBLE IN
EARLY MORNING FOG WEDNESDAY.
VFR CONDITIONS WILL CONTINUE TONIGHT WITH WEAK HIGH PRESSURE AND
A DRY ATMOSPHERE IN PLACE. MOSTLY CLEAR SKIES AND LIGHT WINDS
TONIGHT MAY PROVIDE A FOG THREAT FOR EARLY WEDNESDAY MORNING. THE
LOCAL RADIATION FOG SCHEME SHOWS POTENTIAL FOR FOG WHICH HAS
INCREASED CONFIDENCE. HAVE ADDED A TEMPO GROUP AT AGS FOR IFR
VISIBILITIES AND CONTINUED TO MENTION MVFR FOG AT AGS/OGB. HAVE
KEPT THE OTHER SITES VFR WITH 6SM FOR NOW...BUT WILL UPDATE AS
CONFIDENCE IMPROVES. HIGH CLOUDS WILL INCREASE AFTER 14Z WEDNESDAY.
MOISTURE WILL INCREASE FROM THE SOUTHWEST LATE WEDNESDAY BUT RAIN
CHANCES WILL BE TOO LOW TO MENTION THROUGH THE END OF THE VALID
TAF PERIOD.
EXTENDED AVIATION OUTLOOK...RAIN...WITH MVFR TO IFR
RESTRICTIONS...WEDNESDAY NIGHT THROUGH EARLY FRIDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
718 PM EST TUE DEC 15 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE AREA INTO EARLY WEDNESDAY.
A SLOW MOVING FRONTAL SYSTEM WILL IMPACT THE AREA LATE WEDNESDAY
THROUGH EARLY FRIDAY. COLD HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A WEAK MESO-HIGH ACROSS THE AREA THIS EVENING BECOMES ABSORBED BY
A LITTLE STRONGER HIGH THAT BUILDS FROM THE NORTH LATE TONIGHT.
THIS OCCURS SIMULTANEOUSLY WITH A RIDGE THAT BUILDS ALOFT.
TEMPERATURES HAVE ALREADY BEGUN TO PLUNGE QUICKLY WITH SUNSET
UNDER CLEAR SKIES AND A DECOUPLED ATMOSPHERE...SETTING THE STAGE
FOR EXCELLENT RADIATIONAL COOLING FOR THE VAST MAJORITY OF THE
LOCAL AREA. THE EXCEPTION MIGHT BE PARTS OF FAR SE GA NEAR DARIEN
AND LUDOWICI WHERE THERE IS ISENTROPIC ASCENT ON THE 295K SURFACE
LATE ATOP THE STATIONARY FRONT NOT FAR TO THE SOUTH/SE. THIS COULD
ALLOW FOR SOME LATE NIGHT STRATOCUMULUS TO PUT A CAP ON THE
FALLING TEMPS IN THOSE LOCATIONS AFTER 3 OR 4 AM. FOR MOST OF US
THOUGH IT/LL BE RATHER COOL/CHILLY WITH A LARGE NW-SE TEMPERATURE GRADIENT...
RANGING FROM THE LOWER AND MIDDLE 40S N AND WEST TO LOWER-MIDDLE
50S AT AND NEAR THE COAST...INCLUDING DOWNTOWN CHARLESTON.
RADIATION FOG SEEMS POSSIBLE OVERNIGHT WITH FOG STABILITY INDICES
IN THE SINGLE DIGITS AND TEENS...AND WITH SOME HIGHER RESOLUTION
MESOSCALE MODELS SUCH AS THE RAP AND HRRR INDICATING THE POTENTIAL
FOR REDUCED VISIBILITIES AS WELL. HOWEVER...GIVEN THAT THE LOWEST
CONDENSATION PRESSURE DEFICITS REMAIN JUST TO OUR NORTH/NW IT
SHOULDN/T BE TOO WIDESPREAD AND/OR DENSE. PROBABLY MORE LIKELY
JUST GROUND FOG.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEAK SURFACE HIGH PRESSURE WILL PERSIST ON WEDNESDAY WHILE THE
FLOW ALOFT GRADUALLY BACKS AND STRENGTHENS IN RESPONSE TO A
DIGGING UPPER TROUGH TO THE WEST. WEAK MOIST ISENTROPIC ASCENT
WILL DEVELOP DURING THE AFTERNOON...RESULTING IN A GRADUAL
INCREASE IN CLOUD COVER FROM SOUTH TO NORTH AND LOW-END CHANCES OF
RAIN LATE IN THE DAY. FAIRLY GOOD INSOLATION IN ADVANCE OF THE
CLOUDS AND A WARM AIRMASS WILL SUPPORT HIGH TEMPS IN THE MIDDLE
70S.
A STRENGTHENING SOUTHERLY LOW-LEVEL JET WEDNESDAY NIGHT INTO
THURSDAY WILL ALLOW A WARM FRONT TO LIFT NORTH THROUGH THE AREA
AND SPREAD A MOIST AIRMASS INTO THE SOUTHEAST STATES AHEAD OF THE
COLD FRONT. PWATS EXPECTED TO RANGE FROM 1.75" TO 2" BY MIDDAY
THURSDAY. THERE SHOULD BE A FEW RAIN SHOWERS MOVING THROUGH IN
ASSOCIATION WITH THE WARM FRONT...BUT THE BEST FORCING ARRIVES
LATER ON THURSDAY. FRONTAL FORCING COMBINED WITH MODEST UPPER JET
DIVERGENCE IN CONCERT WITH SIGNIFICANTLY ABOVE-NORMAL PWATS SHOULD
ALLOW FOR WIDESPREAD SHOWERS TO DEVELOP THURSDAY INTO THURSDAY
NIGHT. SURFACE-BASED CAPES OF 500-1000 J/KG AND LIFTED INDICES -2
TO -4C THURSDAY AFTERNOON INDICATE AT LEAST ISOLATED THUNDERSTORM
POTENTIAL. LOW-LEVEL WINDS WILL BE QUITE STRONG ON THURSDAY WITH
925 MB WINDS AROUND 40 KT FROM THE SSW. POCKETS OF MODERATE
INSTABILITY AND STRONG WIND FIELDS MAY SUPPORT AN ISOLATED RISK
FOR A STRONG/SEVERE STORM LATER IN THE DAY. AT A MINIMUM WE EXPECT
BREEZY CONDITIONS AND HIGH TEMPS IN THE MID TO UPPER 70S.
MODELS HAVE SLOWED DOWN THE FRONTAL PROGRESSION SLIGHTLY...KEEPING
A FAIRLY GOOD COVERAGE OF SHOWERS OVER THE AREA THROUGH THURSDAY
NIGHT. IMPROVING CONDITIONS ANTICIPATED FRIDAY WITH CLEARING SKIES
BY AFTERNOON. LATE DAY COLD ADVECTION WILL KEEP TEMPS IN THE UPPER
50S FAR INLAND BUT WE BUMPED HIGHS INTO THE MID 60S NEAR THE COAST
WHERE THE WARM ADVECTION WILL PERSIST THE LONGEST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SURFACE HIGH PRESSURE ACROSS THE CENTRAL U.S. FRIDAY NIGHT WILL MOVE
OVER OR JUST NORTH OF OUR AREA SUNDAY...THEN MOVE OUT TO SEA ON
MONDAY. COLD NORTHWEST FLOW RESULTING FROM THIS HIGH WILL LEAD TO
MUCH COLDER TEMPERATURES THAN THE AREA HAS BEEN EXPERIENCING.
SATURDAY HIGHS WILL BE IN THE MID 50S WHILE SUNDAY MORNING LOWS WILL
BE IN THE LOW TO MID 30S...ABOUT 5 DEGREES BELOW NORMAL.
TEMPERATURES SHOULD BEGIN MODERATING SUNDAY AND MONDAY AS HEIGHTS
BUILD AND FLOW TURNS SOUTHWESTERLY. BUT A COASTAL TROUGH MAY ALSO
DEVELOP BOTH DAYS...LEADING TO POSSIBLY SOME SHOWERS ALONG THE
IMMEDIATE COAST.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THERE IS A POTENTIAL FOR MAINLY PATCHY SHALLOW GROUND FOG TO
DEVELOP IN THE 07-13Z TIME FRAME AND AS A RESULT VISIBILITIES
RESTRICTIONS ARE POSSIBLE. THERE APPEARS TO BE A SLIGHTLY GREATER
POTENTIAL FOR FOG AT KCHS SO HAVE INDICATED MVFR VISIBILITIES
THERE...BUT HELD VISIBILITIES TO 6SM AT KSAV FOR THE TIME BEING.
OTHERWISE...VFR CONDITIONS WILL PREVAIL AT THE TERMINALS.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS EXPECTED
WEDNESDAY THROUGH FRIDAY MORNING AS A FRONTAL SYSTEM AFFECTS THE
AREA.
&&
.MARINE...
TONIGHT...A WEAK PRESSURE PATTERN WILL INFLUENCE CONDITIONS
ACROSS THE ATLANTIC AND IN THE CHARLESTON AND SAVANNAH HARBORS.
SEA BREEZE CIRCULATIONS LESS THAN 10 OR 15 KT WILL FADE THIS
EVENING...AND WINDS WILL STEADILY CLOCK AROUND TO THE WEST AT LESS
THAN 5 OR 10 KT TONIGHT. THE NOSE OF HIGH PRESSURE ARRIVING FROM
THE NORTH LATE WILL CAUSE WINDS TO VEER FURTHER TO THE NORTH/NE
BY DAYBREAK. NOT MUCH WAVE ACTION IN GENERAL...ALTHOUGH BUOY SITES
IN AND NEAR THE LOCAL WATERS SHOWING A VERY SMALL 12-14 SECOND
SWELL FROM THE EAST/NE THAT WILL CONTINUE.
WEDNESDAY AND WEDNESDAY NIGHT WILL FEATURE FAIRLY LIGHTLY WINDS
AND MARGINAL SEAS DUE TO HIGH PRESSURE IN PLACE. A STRONG LOW-
LEVEL JET DEVELOPS ON THURSDAY AHEAD OF A COLD FRONT. WE COULD SEE
GUSTS APPROACHING SMALL CRAFT CRITERIA OVER THE OUTER WATERS OR
PERHAPS IN CHARLESTON HARBOR. A BETTER CHANCE FOR SMALL CRAFT
CONDITIONS WILL SETUP FRIDAY INTO FRIDAY NIGHT AS STRONG COLD
ADVECTION BLOWS OVER THE WATERS BEHIND THE COLD FRONT. BROAD HIGH
PRESSURE OVER THE WEEKEND WILL YIELD DIMINISHING WIND AND SEA
CONDITIONS.
SEA FOG...THERE IS AGAIN THE POTENTIAL FOR SEA FOG LATE WEDNESDAY
NIGHT THROUGH THURSDAY EVENING AS A WARM AND HUMID AIR MASS MOVES
IN OVER THE COOLER SHELF WATERS.
&&
.CLIMATE...
THERE IS A GOOD CHANCE THAT RAINFALL AT THE END OF THIS WEEK WILL
PUSH THE YEARLY RAINFALL TOTAL AT THE CHARLESTON INTERNATIONAL
AIRPORT /KCHS/ ABOVE THE ALL TIME YEARLY PRECIPITATION RECORD. THE
CURRENT RECORD IS 72.99 INCHES THAT WAS SET IN 1964. RECORDS FOR
THE CHARLESTON INTERNATIONAL AIRPORT DATE BACK TO 1938.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JAQ
SHORT TERM...JRL
LONG TERM...
AVIATION...JAQ
MARINE.../JRL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
121 PM EST MON DEC 14 2015
...UPDATED DUE TO AVIATION DISCUSSION...
.SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION...
18Z UPDATE...
FRONTAL SYSTEM MOVING THROUGH THE AREA WITH VFR AND MVFR CEILINGS
AND VSBYS. THE BACK EDGE OF THE PRECIP IS GOING TO MOVE THROUGH
THE ATL AREA OVER THE NEXT 2 HOURS WITH CEILINGS SCATTERING AND
THEN CLEARING OUT SHORTLY BEHIND IT. VSBYS HAVE BEEN UP AND DOWN
ALL MORNING BUT WILL FOLLOW THE LEAD OF THE CEILINGS AND STAY VFR
AS PRECIP MOVES OUT. WINDS ARE OUT OF THE SW AROUND 10KT WITH
SOME GUST TO 20KT ACROSS THE CWA. THESE WINDS WILL START TO LOOSE
THERE GUST AS THE FRONT MOVES EAST AND WILL TURN TO THE NW THROUGH
TUE MORNING.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 47 69 42 / 70 5 0 0
ATLANTA 69 47 68 45 / 100 0 0 0
BLAIRSVILLE 65 42 66 39 / 100 0 0 0
CARTERSVILLE 68 44 66 40 / 100 0 0 0
COLUMBUS 70 46 71 46 / 100 0 0 0
GAINESVILLE 67 47 67 44 / 100 0 0 0
MACON 74 45 72 43 / 50 5 0 0
ROME 67 42 66 39 / 100 0 0 0
PEACHTREE CITY 69 43 69 39 / 100 0 0 0
VIDALIA 78 53 73 51 / 30 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....17
AVIATION...01
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
648 AM EST MON DEC 14 2015
.UPDATE...
A LITTLE FINE TUNING OF POP AND WX...NOT MUCH ELSE. VERY LOW
TOPPED AND NARROW LINE OF CONVECTION. STILL NO CG OR TOTAL
LIGHTNING DETECTED THAT WE KNOW OF. CLEARING WILL TAKE PLACE
QUICKLY THIS AFTERNOON.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 343 AM EST MON DEC 14 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION...
12Z UPDATE...
PERIODS OF VERY LIGHT SHRA OR DZ LIKELY BEFORE LINE MOVES IN.
SHOULD REACH KATL AROUND 15Z. WINDS SHOULD REMAIN JUST EAST OF DUE
SOUTH WITH GUSTS TO 25KTS UNTIL LINE/FRONT MOVES THROUGH THEN
WEST THEN SW WITH DECREASING SPEEDS THROUGH THE DAY.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 47 69 42 / 70 5 0 0
ATLANTA 69 47 68 45 / 100 0 0 0
BLAIRSVILLE 65 42 66 39 / 100 0 0 0
CARTERSVILLE 68 44 66 40 / 100 0 0 0
COLUMBUS 70 46 71 46 / 100 0 0 0
GAINESVILLE 67 47 67 44 / 100 0 0 0
MACON 74 45 72 43 / 50 5 0 0
ROME 67 42 66 39 / 100 0 0 0
PEACHTREE CITY 69 43 69 39 / 100 0 0 0
VIDALIA 78 53 73 51 / 30 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...FANNIN...FLOYD...GILMER...
GORDON...LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
SHORT TERM...SNELSON
LONG TERM....DEESE
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
343 AM EST MON DEC 14 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION... 06Z UPDATE... PRIMARY CONCERNS ARE TIMING OF IFR
CIGS NEXT FEW HOURS AND SHRA LATER THIS MORNING. WITH THICK
CIRRUS...AGAIN LOW STRATUS SLOW TO FORM. AS LINE OF SHRA
APPROACHES...SHOULD SEE STRATUS FILL IN QUICKLY. SHRA EXPECTED
14-17Z AT ATL METRO AIRPORTS. COVERAGE OF SHRA EXPECTED TO
DECREASE STEADILY DURING THE DAY...SO TEMPO USED AT KMCN. SFC
WINDS WILL SWITCH TO SW AS LINE PASSES. GUSTS TO 20-22KTS POSSIBLE
ALONG AND AHEAD OF SHRA.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON IFR CIGS DEVELOPING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 69 48 70 44 / 90 0 0 5
ATLANTA 69 48 69 47 / 80 0 0 5
BLAIRSVILLE 64 43 66 38 / 80 0 0 5
CARTERSVILLE 68 44 67 41 / 90 0 0 5
COLUMBUS 70 46 72 50 / 80 0 0 5
GAINESVILLE 67 48 67 45 / 80 0 0 5
MACON 73 46 72 47 / 80 10 0 5
ROME 66 42 67 40 / 90 0 0 5
PEACHTREE CITY 69 44 70 43 / 80 0 0 5
VIDALIA 76 54 74 54 / 50 10 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...FANNIN...FLOYD...GILMER...
GORDON...LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
SHORT TERM...SNELSON
LONG TERM....DEESE
AVIATION...SNELSON
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
252 PM CST MON DEC 14 2015
.SHORT TERM...(Tonight)
ISSUED AT 252 PM CST MON DEC 14 2015
Main forecast challenge in the short term will be the extent of
lingering scattered showers and the spread of drizzle this evening,
and the extent of cloud cover overnight.
The latest surface analysis at 20Z (2 pm cst) indicated an area of
low pressure in northeast IA with a trough extending southwest into
extreme northwest MO. A short wave trough axis extended from an
upper low in northeast IL into west central IL. This was producing
scattered showers in western and central IL this afternoon. These
showers are expected to shift into NE-east central IL early this
evening as the trough axis rotates through the area. Lingering low
level moisture and weak lift should produce some patchy drizzle
during the evening mainly north of a Macomb-Bloomington-Danville
line.
The short range models are in a bit of a disagreement regarding the
amount of any breaks/clearing in the cloud cover overnight. The NAM,
SREF and HRRR indicate that the clouds shouldn`t start breaking up
until later Tuesday morning, while the GFS and RAP are trying to
clear things up around or just before daybreak. Prefer the slower
solutions of keeping the cloud cover over the forecast area into the
morning. Even if the quicker clearing models verify, the saturated
ground and lighter surface winds should allow for stratus and fog to
develop quickly. With the clouds and gradually decreasing westerly
winds, temperatures overnight will only drop slowly into the 36-40
degree range.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 252 PM CST MON DEC 14 2015
After a dry period tomorrow, another weather system is forecast to
move out of the southern Rockies and northeast across the plains and
into the western Great Lakes region. A cold front associated with
this system will slide across the CWA on Wednesday. Ahead of the
front, tomorrow into tomorrow night, limited low level moisture will
be advected northward into the area. Based on this and limited
dynamics, showers will be possible late tomorrow night through
Wednesday, across the CWA. By Wed evening, the front will have
pushed east of the area and the pcpn will have ended, leaving Wed
night and Thur dry.
Temps will remain mild/above normal through Wed, but then fall to
around normal for Thursday, behind this brief system. Model guidance
looks good through the period.
The remainder of the week and into the weekend will be dry as a
large mid level trough tracks across the US. This trough and
associated sfc high pressure area will bring dry weather and colder
temps. Northwest flow will be temporary for Sat and then transition
back to southwest flow for Sunday and Monday. The southwest flow
will allow southerly winds to return on the sfc, bringing above
normal temps back to the area for Sun and Mon. Along with the warmer
temps, pcpn will return for Sunday night and Mon as another weather
system moves toward and through the area.
Temps will be around or just below normal for Fri and Sat, but then
with southerly winds returning, temps will return to above normal
levels for Sun and Mon.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CST MON DEC 14 2015
A few breaks in the MVFR conditions are being noted just before
18z in parts of central and western IL behind a shortwave that is
rotating around an upper low in NE Iowa. This will be short lived
as generally MVFR ceilings upstream move into the region. In
addition, VFR ceilings and light rain in eastern IL along the
shortwave trough axis will eventually be dropping into the MVFR
category during the afternoon.
The upper low is expected to lift to western MI by early this
evening, and then rapidly across southern Ontario. At the lower
levels and the surface, central and eastern IL will remain in the
cyclonic flow up until daybreak. This should keep enough low level
moisture in place for MVFR ceilings through the night. As we
approach the pre-dawn hours, surface winds will decrease which
should allow visibilities to drop to 3-5 miles with IFR ceilings.
The NAM and RAP models are both showing this scenario, with the
GFS model seeming to clear us out too quickly. However, even if
the GFS verifies, the light wind and saturated ground would cause
stratus and fog to develop rather quickly. Am expecting the
ceilings to improve to at least MVFR by late morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Miller
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1200 PM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 1104 AM CST MON DEC 14 2015
Made minor adjustments to the forecast based on current radar and
satellite trends. The back end of the last band of showers
associated with a shortwave, rotating around the upper low near
Dubuque, is moving through east central IL late this morning. This
will be accompanied by light to moderate rain and wind gusts of
30-40 mph into the Noon hour before it moves out of the region.
Scattered showers will move back into/develop in the forecast
area this afternoon as the upper low lifts toward western MI. The
presence of clouds and periods of light showers will keep
temperatures nearly steady early this afternoon with a slow
downward trend toward late afternoon as winds veer from the west.
Gusty winds will continue through the afternoon as the surface
gradient stays strong and low level winds mix down with the
showers.
A few showers may linger in extreme eastern IL early this
evening, otherwise the rest of the forecast area will dry out with
mostly cloudy conditions hanging around for much of the night.
&&
.SHORT TERM...(Today)
ISSUED AT 325 AM CST MON DEC 14 2015
Strong low pressure, currently centered over eastern Iowa, will
continue to impact central and southeast Illinois today. The cold
front associated with the system currently extends southeast across
northern Illinois, and has already cleared entire forecast area.
Post frontal cold air advection is actually spreading across the
region from the southwest, a somewhat unusual occurrence. The strong
cold advection will prevent much of a temperature rise today, with
temperatures expected to be steady or slowly falling for the most
part. That being said, daytime highs will still be well above
normal, in the lower 50s, for the middle of December. The winds
bringing in this colder air are expected to remain quite gusty
today, with gusts to 35 mph likely for much of the day.
The more widespread/heavier rainfall associated with this storm
system will be north/east of the forecast area to start the day.
However, the upper low/cold pool driving the surface system is still
centered near the KS/MO border area. The upper circulation is
expected to lift into the Great Lakes by this evening, and scattered
showers are expected until the circulation clears the Midwest.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 325 AM CST MON DEC 14 2015
Ending the precip this evening is the first issue for the forecast.
Previous runs have been pretty persistent in drying out much of
Central Illinois by late this afternoon. The 06Z NAM is the hold
out, lingering some precip in the north and east as the system pulls
away. Have kept the forecast dry after 00z for now, but will see if
the NAM remains the outlier. Next issue for the forecast through
the overnight is to watch the potential for fog development yet
again. At this point, forecast has too many clouds for efficient
radiational cooling, and the winds stay up a bit more as well.
Weaker wind field just to the SW however. Crossover temps this
afternoon will be key, but just not enough to go with a fog mention
in the forecast just yet. Tonight and tomorrow mainly dry. Models
bringing the second low through the region quickly for tomorrow
night and Wednesday. Models are more consistent with the precip
along the boundary now, so chance pops progress across the CWA
through that time frame. Some cooler air moves into the region
behind Wednesdays front, and Friday and Saturday are the coolest
days in the forecast with highs only reaching into the 30s. Saturday
night however, the winds pick back up out of the SW and another warm
up starts to wrap up the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CST MON DEC 14 2015
A few breaks in the MVFR conditions are being noted just before
18z in parts of central and western IL behind a shortwave that is
rotating around an upper low in NE Iowa. This will be short lived
as generally MVFR ceilings upstream move into the region. In
addition, VFR ceilings and light rain in eastern IL along the
shortwave trough axis will eventually be dropping into the MVFR
category during the afternoon.
The upper low is expected to lift to western MI by early this
evening, and then rapidly across southern Ontario. At the lower
levels and the surface, central and eastern IL will remain in the
cyclonic flow up until daybreak. This should keep enough low level
moisture in place for MVFR ceilings through the night. As we
approach the pre-dawn hours, surface winds will decrease which
should allow visibilities to drop to 3-5 miles with IFR ceilings.
The NAM and RAP models are both showing this scenario, with the
GFS model seeming to clear us out too quickly. However, even if
the GFS verifies, the light wind and saturated ground would cause
stratus and fog to develop rather quickly. Am expecting the
ceilings to improve to at least MVFR by late morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Miller
SHORT TERM...BAK
LONG TERM...HJS
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
217 AM EST MON DEC 14 2015
.SYNOPSIS...
ISSUED AT 153 AM EST MON DEC 14 2015
RAIN WILL OVERSPREAD THE AREA EARLY TODAY AS A STRONG SYSTEM
APPROACHES AND MOVES INTO THE UPPER GREAT LAKES REGION.
TEMPERATURES WILL BE FALLING TODAY AS COOLER AIR SPREADS OVER THE
AREA BEHIND A COLD FRONT. HOWEVER...TEMPERATURES WILL STILL BE
MILD UNTIL THURSDAY WHEN A STRONGER COLD FRONT PASSES. LOWS WILL
DROP WELL BELOW FREEZING BY FRIDAY MORNING.
&&
.UPDATE...
ISSUED AT 714 PM EST SUN DEC 13 2015
MODEST UPDATE TO CUT BACK/SLOW DOWN POPS FOR THE OVERNIGHT
PERIOD...MAINLY IN OUR SOUTHEAST HALF. INITIAL WING OF 295K
ISENTROPIC ASCENT CURRENTLY LIFTING NORTH AND EXPECT A RELATIVE
LULL IN STEADIER PRECIP FOR MOST OF OUR AREA THROUGH MUCH OF
TONIGHT AS THIS ACTIVITY LIFTS NORTH. A FEW LINGERING SHOWERS
POSSIBLE IN OUR NW HALF AS SUGGESTED BY LATEST HRRR BUT SE HALF
WILL LIKELY REMAIN DRY THROUGH 06-09Z. COLD FRONT WILL THEN SWEEP
FROM WEST TO EAST EARLY MONDAY MORNING WITH WIDESPREAD SHOWERS.
REST OF THE FORECAST REMAINS IN GOOD SHAPE. UPDATED ZFP WILL BE
OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
SOLID/DEEP NATURE OF CLOUD COVER HELD LINE ON TEMPS...DESPITE
RECORD/NEAR RECORD AT THIS TIME WITH TEMPS INTO MID 60S SERN
CWA/LWR 60S ELSEWHERE. STILL POTENTIAL FOR DEGREE/TWO RISE NEXT
HOUR AND CERTAINLY POTENTIAL FOR HIGHER EXISTED FOR A TIME.
PRIMARY FOCUS ONTO UPSTREAM STRONGLY DYNAMIC MID TROPOSPHERIC
SYSTEM OVER CENTRAL OKLAHOMA AS IT BEGINS ASSERTIVE NORTHEASTWARD
LIFTOUT. PRESENT ELEVATED COLD CONVEYOR BELT/OCCLUSION ASSOCIATED
RAIN SHIELD WITH EMBEDDED/SHALLOW CONVECTIVE ELEMENTS WILL
PRIMARILY LIFT NORTHWARD WITH FAR EASTERN PERIPHERY TO LIFT
THROUGH WESTERN THIRD OF CWA THIS EVENING. LATER TONIGHT
PSUEDO/SECONDARY COLD FRONT ASSOCIATED WITH FRONTAL WAVE
/PRESENTLY DEVELOPING OVER SOUTHERN MISSOURI/ TO PRESS NEWD INTO
CWA. CORE OF RICH THETA-E/MIXING RATIOS WITH PLUS 9 G/KG IN
1000-850MB LAYER TO SUPPORT SECOND ROUND OF SHRA PRESSING FARTHER
EAST INTO CWA AS EXTREME 70-75 KT 8H JET AXIS ROTATES CCW INTO
INDIANA. BEST FORCED LIFT APPEARS IN 060-09 UTC WINDOW.
THEREAFTER...SUSPECT OVERALL DIMINISHMENT IN COVERAGE/INTENSITY
BEYOND 12 UTC...THOUGH INFLUENCE OF EXTREME/250-300M/12 HR HEIGHT
FALL CENTROID OVER NERN IL MIDDAY ALONG WITH CWA POISED WITHIN
FAVORABLE EXIT REGION OF 120-130 KT JET CORE OVER WEST CENTRAL
OHIO SHOULD AID IN CONVECTIVE MAINTENANCE MONDAY MORNING. MOISTURE
DEPTH/PWAT LOWER REMARKABLY AS DEPTH OF MOISTURE/MID LEVEL DRY
SLOTTING OVERSPREADS W-E THROUGH AFTERNOON LIMITING AMOUNTS
THEREAFTER. PROGRESSIVE NATURE OF SYSTEM ASSURED WITH PRESS OF YET
ANOTHER STRONG UPSTREAM SYSTEM INTO GREAT BASIN BY 00 UTC TUE.
THIS AND DISJOINTED NATURE OF RAFL EPISODES TO LIMIT TOTAL QPF TO
AMOUNTS EASILY HANDLED BY BASIN DRAINAGE SYSTEM. TEMPERATURES NON
DIURNAL WITH EXTREMELY WARM OVERNIGHT LOWS IN WELL MIXED
HOMOGENEOUS BOUNDARY LAYER AND FALLING THROUGH DAY/EARLY HIGHS
MON.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
QUICK RECOVERY IN MID/UPPER LEVEL HEIGHTS IN WAKE OF EXITING
UPPER LOW WILL ALLOW TEMPS TO REMAIN ABOVE NORMAL INTO TUESDAY AND
WEDNESDAY AS WARM ADVECTION RESUMES IN ADVANCE OF THE NEXT UPPER
LOW/SFC REFLECTION TO EJECT NORTHEAST THROUGH THE UPPER MIDWEST.
THIS PROCESS WILL BRING AN END TO ANY PCPN MONDAY NIGHT THROUGH
TUESDAY NIGHT...ALTHOUGH SUBSIDENCE/DRYING NOT ALL THAT IMPRESSIVE
WITH WARMING OVER INVERSION LIKELY LOCKING IN LOW CLOUDS LONGER
THAN CURRENTLY MODELED. LIGHT RAIN SHOWER CHANCES THEN RETURN
WEDNESDAY INTO WEDNESDAY EVENING ALONG A COLD FRONT. KEPT POPS IN
LOW-MID CHANCE RANGE...HIGHEST ACROSS NW IN/SW MI...GIVEN LACKING
MOISTURE QUALITY/RETURN.
SOLID MODEL AGREEMENT REMAINS FOR A SHOT OF COLDER/SEASONABLE AIR
THURSDAY THROUGH SATURDAY AS LONGWAVE TROUGH PROGRESSES EAST
THROUGH EASTERN NOAM. THIS COLD FLOW OVER WARMER LAKE MI WATER
SUPPORTS LOW- MID CHANCE POPS FOR LAKE EFFECT SNOW SHOWERS IN
FAVORED WEST FLOW LE ZONES. WARMER AIR WILL THEN FILTER BACK INTO
THE REGION SUNDAY INTO EARLY NEXT WEEK AS HEIGHT FIELD RELAXES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 146 AM EST MON DEC 14 2015
A LARGE DEEP LOW WAS OVER EASTERN KANSAS EARLY TODAY WITH THE
COLD AIR WRAPPING AROUND THE LOW ACROSS MISSOURI. THE COLD FRONT
WILL RACE EAST TODAY AND MOVE ACROSS NORTHERN INDIANA. THERE
SHOULD BE A FEW TO SEVERAL HOURS OF RAIN GIVEN A VERY MOIST FETCH
WITH THE LOW LEVEL CONVEYOR BELT. THE DRY SLOT WILL SPREAD OVER
THE AREA THIS AFTERNOON...BUT SOME SHOWERS ARE STILL POSSIBLE
GIVEN THE VERY COLD TEMPERATURES ALOFT. KEPT SLEET OUT OF THE TAFS
FOR NOW GIVEN EXPECTED RELATIVELY WARM BOUNDARY LEVEL TEMPS.
INCREASED WINDS FROM THE ONGOING TAFS TO COME MORE IN LINE WITH
THE LATEST NCEP/WPC HIGH RES GUIDANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LMZ043-046.
&&
$$
UPDATE...AGD
SYNOPSIS...MURPHY/SKIPPER
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...SKIPPER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
517 PM CST TUE DEC 15 2015
...Updated Aviation discussion...
.SHORT TERM...(THIS AFTERNOON THROUGH Wednesday)
ISSUED AT 1047 AM CST TUE DEC 15 2015
Late this morning, fairly strong cold advection was occurring in the
800-700mb layer, but below this layer the cold advection was being
masked by downslope given the fairly strong cross-terrain component
as the mid level cyclone tracks north of southwest KS. Temperatures
at the surface will likely plateau or very slowly crawl through the
upper 30s to around 40 for a high. The exception will be across far
south central Kansas where places like Kiowa in Barber County may
touch the mid 50s ahead of the front. We will have to watch for
possible very light snow up in western/northern Trego County later
this evening as the southern tip of wrap-around TROWAL could clip
the I-70 corridor. The probability of any accumulating snow would be
extremely low, however. Winds will be out of the west-northwest
tonight in the wake of the storm system. With the colder airmass in
place, though, we should see lows bottom out in the lower to mid 20s
for most locations and upper teens across far southwest and west
central KS.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 338 PM CST TUE DEC 15 2015
The primary meteorological feature of interest that will have some
influence on sensible weather is a quick-moving disturbance moving
southeast through the Rockies and adjacent High Plains late
Wednesday Night into Thursday. All the models (global spectral and
limited area hi-res) suggest strong mid level cold advection and
attendant deep tropospheric lift moving into southwest KS in the
09-18z time frame Thursday. There will not be any influx of
moisture out ahead of this wave, but there will be enough lift in
the 800-600mb layer to saturate, and given much lower altitude of
the dendritic growth zone (-12 to -18C) vs. the big storm on
Sunday, we should see more classical dendrite snow which
accumulates easier vs. the clumping aggregate snow we had with the
Sunday storm. It will be a light QPF event, but there is higher
enough confidence in the light QPF event to warrant some Chance
POPs, mainly across the far southwest KS zones. In the grids, QPF
for this event will be in the 0.01 to 0.05 inch range -- again
emphasis on very light. This would support a few tenths of an inch
of snow and perhaps a shade above a half inch in some spots.
We will quickly revert to a downslope warming pattern for Friday
and into the weekend with a gradual warm up reaching a crescendo
Sunday before the next (weak) Pacific storm system zips across and
brings a front through. We will remain in a fairly high zonal
index large scale patter through mid next week, but there are
hints of amplification of the Gulf of Alaska ridge toward the end
of this period which could foster development of a deep downstream
trough out west in the 25-26 December time frame.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Wednesday EVENING)
ISSUED AT 512 PM CST TUE DEC 15 2015
Gusty west to northwest winds can be expected behind a cold front
that will cross southwest Kansas early tonight. These gusty
northwest winds at around 20 knots will decrease to around 15
knots after 04z as a surface ridge axis begins to slowly build
into far western Kansas. Winds will fall back into the 10 to 15
knot range early Wednesday morning. A period of MVFR conditions
will also be possible early tonight behind this cold front with
the latest RAP and HRRR suggesting that this will be most likely
in the Hays area. Elsewhere just scattered clouds are expected
through 03z in the 1000 to 3000 foot AGL range.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 23 37 20 32 / 0 0 10 20
GCK 19 37 18 33 / 0 0 20 30
EHA 16 37 19 32 / 0 0 20 30
LBL 21 38 19 34 / 0 0 20 30
HYS 25 37 19 32 / 20 10 10 10
P28 28 43 23 39 / 0 0 10 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Burgert
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
334 PM CST MON DEC 14 2015
.SHORT TERM...(This Evening through Tuesday)
Issued at 329 PM CST MON DEC 14 2015
Upper ridge building in between the old upper system nearing the
Great Lakes and the next deep system developing over the Central
Rockies. Surface pressure rises rather strong just to the northeast,
though considerable falls occurring in eastern Colorado. Northwest
winds decreasing in eastern Kansas, with east winds already
developing in western portions of the state. Stratus, rather thin in
spots, was making only slow progress east on latest satellite loop
with local dewpoint depressions in the 3-10F range.
Main concerns into Tuesday are at the very low levels, unfortunately
where model skill is at its lowest. The next system crosses the
Rockies tonight with surface low entering Kansas. Winds will be
quite light between these systems much of the evening though pick up
toward dawn. With a very wet ground and wet boundary layer, a
favorable setup for radiational fog is in place...if clearing can
occur. So far, guidance has shown very poor skill in handling the
very slow clearing and where it is and is not occurring. Even 19 and
20Z RAP and 15Z SREF data is quite poor in its initial few hours of
progs. Skies could easily remain rather cloudy for especially
northern areas through the night, but think at least enough patches
of clearing are possible for some fog formation. Have kept any
mention limited to the late evening through 12Z as winds/mixing
increase late in the night. Guidance that is more pessimistic with
the stratus suggests some light drizzle could also occur, but the
thin nature of the cloud and little if any lift in it should keep it
from being notable, and temps/ground temps largely warm enough to
keep slick road issues at bay if it were to form. Have kept Tuesday
rather warm given temps in south central Kansas in the low-mid 50s
today. Moisture in the mid and upper levels is rather hard to come
by with the system this far southeast, but will keep a small PoP in
the far northwest nearer the better moisture.
.LONG TERM...(Tuesday Night through Monday)
Issued at 329 PM CST MON DEC 14 2015
Dry cold front moves through the forecast area Tuesday night, as
the next upper low moves across Nebraska and to the north
northeast dragging the front behind. Additional waves moving
through this upper trof keep the Central Plains in the colder air
through Friday. Highs drop to the upper 30s to near 40, with lows
falling into the 20s. Still on track to warm up a bit for the
weekend as upper ridge moves across the state and highs rise back
into the 40s and 50s. Next chance for rain starts Monday but wave
is low amplitude and part of a larger upper system that approaches
the Central Plains later in the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1143 AM CST MON DEC 14 2015
Currently, MVFR ceilings are in place across much of northeast
Kansas. These ceilings are expected to scatter out to VFR later
this afternoon as the low continues to move north. Confidence is
lower toward the end of the period as there is a chance for reduced
visibilities and ceilings again tomorrow morning. Winds appear to
stay high enough to prevent any fog formation at this time and have
left any MVFR conditions out of this TAF issuance.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Heller
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
841 PM CST TUE DEC 15 2015
.UPDATE...
Issued at 842 PM CST TUE DEC 15 2015
The primary issues this evening are wind trends and their impact
on temperatures. Winds are expected to veer to southeast and
increase by morning, but many sites, especially in the east, may
go calm for awhile this evening. Radiational cooling could take
readings into the 30s, but once a more persistent breeze becomes
established, temperatures are likely to increase. Over western
portions of southeast Missouri, clouds will begin to increase in
the next few hours, and winds are expected to be more persistent.
Temperatures there may not drop much below 50 except in more
sheltered areas. Have updated twice to try and account for these
difficult trends, and will continue to monitor and adjust as
needed for the remainder of the evening.
UPDATE Issued at 546 PM CST TUE DEC 15 2015
The AVIATION section has been updated for the 00Z TAF issuance.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 257 PM CST TUE DEC 15 2015
The region will remain be under the influence of surface high
pressure located over the upper Ohio Valley this evening. However,
A vigorous upper level low pressure system lifting northeast from
the Plain into the Midwest overnight will push a cold front into
the region on Wednesday. Though the mid level trof looks
formidable, little chc for deep moisture return and weak
convergence in the lower levels will likely limit and any precip
to areas of light rain. Most locations should see less than a
tenth of an inch rain totals from this frontal passage, though
some locations could see slightly higher amounts if the more
robust ECMWF comes to fruition.
Models do differ to some degree on how quickly the front moves
through Wed night, with the ECMWF/NAM lagging the quicker 12z
operational GFS. Therefore, will need to keep some chcy POPs in
the southern Pennyrile through Wednesday evening in case the front
does indeed slow down as another piece of energy ejects east from
the Plains and a surface low moves northeast into the TN River
Valley. A short lived transition to more seasonal conditions will
begin on Thursday as chilly high pressure begins to build in from
the west.
.LONG TERM...(Thursday night through Tuesday)
Issued at 257 PM CST TUE DEC 15 2015
urface high pressure will be centered over southwest Texas at 12z
Friday, moving east over the east coast of North Carolina coast by
12z Sunday. As the high moves south of our region, winds will
gradually shift from westerly on Friday to southerly by late
Saturday into Sunday. This will give us our coolest period of the
forecast Friday into Friday night, with temperatures two to five
degrees below seasonal normals. Temperatures will rebound to near
seasonal for Saturday, then increasing south winds ahead of our next
system will bring warmer air into the region.
On Sunday, clouds will increase from the west as a cold front
approaches from the west. Models spread showers across the PAH
forecast area Sunday night, with GFS being most aggressive with more
significant QPF amounts. Leaned more toward the ECMWF amounts due
to limited initial moisture return. Chances will increase on Monday
as the front moves across our area, but the front will hang up over
our southeast counties. This will linger precipitation chances into
Monday night, then another surge of moisture is expected Tuesday as
another surface low moves into the middle Mississippi valley. Models
show some instability across western portions of our forecast area
Monday, and kept slight chances of thunderstorms in southeast
Missouri and portions of west Kentucky and southern Illinois. A
little better instability will accompany the Tuesday surface low, so
included slight chances of thunderstorms for all but our far
northern counties.
&&
.AVIATION...
Issued at 546 PM CST TUE DEC 15 2015
A fast moving storm system will bring a quick return to south
winds by morning, and rapid development of clouds and possibly a
few showers during the day. The primary band of clouds/showers
will pass quickly eastward through the TAF sites. Not confident
at all in impactful precipitation, so left the VCSHs going at all
sites. Not sure if MVFR ceilings will accompany the initial surge
of cloud cover/showers, but they are likely fill in at all sites
through the afternoon.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MEFFERT
LONG TERM...RST
AVIATION...DRS
[top]
Area Forecast Discussion
National Weather Service Louisville KY
930 PM EST TUE DEC 15 2015
...Forecast Update...
Updated 925 PM EST Tue Dec 15 2015
Made a few minor forecast changes this evening. First of all, temps
have dropped across southern Indiana and northern Kentucky a little
bit more than previously forecast so will lower mins for tonight in
that area. Overall mins should range from the lower 30s to lower
40s.
Also added an area of patchy dense fog just before sunrise over the
Lake Cumberland region. Both the NAM and HRRR are picking up on
better conditions for some patchy dense fog in that region
especially in the valley locations.
.SHORT TERM (Now through Wednesday)...
Issued at 245 PM EST Tue Dec 15 2015
Cloud trends this evening, fog potential overnight and shower
chances Wednesday are the main forecast challenges in the short
term.
As of mid-afternoon, water vapor imagery and 500 mb heights showed
the lower Ohio Valley under a weak ridge, between two closed lows
over the CONUS. At the surface, high pressure axis was from north FL
through lower MI. A 50-100 mb thick stratus deck trapped around 2-3
kft has been slowly eroding and lifting northward thanks to
increasing south winds and daytime mixing. Temperatures were in the
50s.
Using visible satellite trends and the HRRR cloud fields, expecting
back edge of the cloud deck to continue work its way northward,
reaching our southern Indiana counties by sunset. The limited mixing
today coupled with light winds right at the surface and high
pressure overhead will promote patchy to areas of fog to develop
across the area overnight through early morning hours. The SREF
probabilities and hi-res model visibility plots show the highest
threat to be across the Lake Cumberland to Bluegrass regions,
especially in the river valleys and other typical fog prone areas.
The main limiting factor for dense fog looks to be increasing
south/southwest winds just off the deck overnight that could keep
the boundary layer mixed enough. Otherwise, plan on lows in the
upper 30s to mid 40s.
A surface low will track from the central Plains to the Upper
Midwest overnight into Wednesday. A moisture-limited cold front will
cross the forecast area late tomorrow morning into the afternoon
hours. Dynamics aren`t impressive and moisture transport is narrow
as it crosses the region, so continued to keep shower chances in the
20-40 percent range, mostly in the afternoon hours. We should warm
up nicely ahead of this system, topping out in the low to mid 60s
with steady south winds 10-20 mph.
.LONG TERM (Wednesday Night through Monday)...
Issued at 250 PM EST Tue Dec 15 2015
Wednesday Night - Thursday
The cold front will slow down Wednesday night as it crosses the
region, stalling somewhat over eastern Kentucky while a southern
stream impulse lifts more moisture back to the north. More
widespread rain will then overspread east of I-65, especially along
the I-75 corridor through the Thursday morning commute. Plan on lows
to range from the mid 30s west of I-65, to the low/mid 40s along the
I-75 corridor under deeper clouds and rain. Precipitation should
quickly end west to east Thursday morning.
A digging upper trough will bring seasonably cold air into the
region, as seen by crashing 850 mb temperatures throughout the day.
Temperatures won`t rise too much or even remain steady, especially
in our northwest. Highs in the mid 40s to low 50s.
Friday - Friday Night
The bulk of the cold airmass will be overhead during this time frame
as the upper trough axis swings through the lower Great Lakes into
the mid-Atlantic regions. A quick moving shortwave will round the
base of the trough. As the case with these clippers, moisture is
limited but some of that moisture does lie within the dendritic
growth zone /-10 to -15C/. A flurry or sprinkle, depending on
boundary layer temps, is possible across the northern forecast area,
say from Louisville metro and points east/north. Plan on highs in
the mid 30s to low 40s, and lows Friday night solidly in the 20s.
Saturday - Sunday
A dry and seasonable weekend is expected over the region. After a
slow start, temperatures will warm to the low and mid 40s on
Saturday under sunny skies. Surface high pressure moves east by
Saturday night, with light southerly flow returning.
This sets up our typical ridge/valley split nights where eastern
decoupled valleys stay in the low and mid 20s. Elsewhere, mixed
locations will see upper 20s to around 30. Milder conditions return
for Sunday under a steady south flow. Look for highs in the lower
50s.
Monday - Tuesday
A more active weather pattern is looking increasingly likely over
the area next week as a series of impulses lift out of the Plains to
the Great Lakes. Synoptically, a trough out west with ridging over
the east will favor above normal temperatures and chances of rain.
&&
.AVIATION (00Z TAF Update)...
Updated at 615 PM EST Tue Dec 15 2015
A mostly VFR TAF is expected as we sit in between weather systems
for much of the TAF period. We`ll see an increase in upper level
clouds late tonight with a brief period of MVFR br possible at BWG
toward sunrise. For tomorrow, southerly winds will pick up ahead of
a cold front gusting into the 18-22 kt range especially during the
afternoon hrs. Some light showery activity along the front will
affect the BWG/SDF sites near the end of this TAF period. Behind
the front, MVFR cigs are possible for tomorrow night with winds
veering to the west.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........AMS
Short Term.....ZT
Long Term......ZT
Aviation.......AMS
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
546 PM CST TUE DEC 15 2015
.UPDATE...
Issued at 546 PM CST TUE DEC 15 2015
The AVIATION section has been updated for the 00Z TAF issuance.
&&
.SHORT TERM...(This evening through Thursday)
Issued at 257 PM CST TUE DEC 15 2015
The region will remain be under the influence of surface high
pressure located over the upper Ohio Valley this evening. However,
A vigorous upper level low pressure system lifting northeast from
the Plain into the Midwest overnight will push a cold front into
the region on Wednesday. Though the mid level trof looks
formidable, little chc for deep moisture return and weak
convergence in the lower levels will likely limit and any precip
to areas of light rain. Most locations should see less than a
tenth of an inch rain totals from this frontal passage, though
some locations could see slightly higher amounts if the more
robust ECMWF comes to fruition.
Models do differ to some degree on how quickly the front moves
through Wed night, with the ECMWF/NAM lagging the quicker 12z
operational GFS. Therefore, will need to keep some chcy POPs in
the southern Pennyrile through Wednesday evening in case the front
does indeed slow down as another piece of energy ejects east from
the Plains and a surface low moves northeast into the TN River
Valley. A short lived transition to more seasonal conditions will
begin on Thursday as chilly high pressure begins to build in from
the west.
.LONG TERM...(Thursday night through Tuesday)
Issued at 257 PM CST TUE DEC 15 2015
urface high pressure will be centered over southwest Texas at 12z
Friday, moving east over the east coast of North Carolina coast by
12z Sunday. As the high moves south of our region, winds will
gradually shift from westerly on Friday to southerly by late
Saturday into Sunday. This will give us our coolest period of the
forecast Friday into Friday night, with temperatures two to five
degrees below seasonal normals. Temperatures will rebound to near
seasonal for Saturday, then increasing south winds ahead of our next
system will bring warmer air into the region.
On Sunday, clouds will increase from the west as a cold front
approaches from the west. Models spread showers across the PAH
forecast area Sunday night, with GFS being most aggressive with more
significant QPF amounts. Leaned more toward the ECMWF amounts due
to limited initial moisture return. Chances will increase on Monday
as the front moves across our area, but the front will hang up over
our southeast counties. This will linger precipitation chances into
Monday night, then another surge of moisture is expected Tuesday as
another surface low moves into the middle Mississippi valley. Models
show some instability across western portions of our forecast area
Monday, and kept slight chances of thunderstorms in southeast
Missouri and portions of west Kentucky and southern Illinois. A
little better instability will accompany the Tuesday surface low, so
included slight chances of thunderstorms for all but our far
northern counties.
&&
.AVIATION...
Issued at 546 PM CST TUE DEC 15 2015
A fast moving storm system will bring a quick return to south
winds by morning, and rapid development of clouds and possibly a
few showers during the day. The primary band of clouds/showers
will pass quickly eastward through the TAF sites. Not confident
at all in impactful precipitation, so left the VCSHs going at all
sites. Not sure if MVFR ceilings will accompany the initial surge
of cloud cover/showers, but they are likely fill in at all sites
through the afternoon.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...MEFFERT
LONG TERM...RST
AVIATION...DRS
Area Forecast Discussion
National Weather Service Louisville KY
616 PM EST TUE DEC 15 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Wednesday)...
Issued at 245 PM EST Tue Dec 15 2015
Cloud trends this evening, fog potential overnight and shower
chances Wednesday are the main forecast challenges in the short
term.
As of mid-afternoon, water vapor imagery and 500 mb heights showed
the lower Ohio Valley under a weak ridge, between two closed lows
over the CONUS. At the surface, high pressure axis was from north FL
through lower MI. A 50-100 mb thick stratus deck trapped around 2-3
kft has been slowly eroding and lifting northward thanks to
increasing south winds and daytime mixing. Temperatures were in the
50s.
Using visible satellite trends and the HRRR cloud fields, expecting
back edge of the cloud deck to continue work its way northward,
reaching our southern Indiana counties by sunset. The limited mixing
today coupled with light winds right at the surface and high
pressure overhead will promote patchy to areas of fog to develop
across the area overnight through early morning hours. The SREF
probabilities and hi-res model visibility plots show the highest
threat to be across the Lake Cumberland to Bluegrass regions,
especially in the river valleys and other typical fog prone areas.
The main limiting factor for dense fog looks to be increasing
south/southwest winds just off the deck overnight that could keep
the boundary layer mixed enough. Otherwise, plan on lows in the
upper 30s to mid 40s.
A surface low will track from the central Plains to the Upper
Midwest overnight into Wednesday. A moisture-limited cold front will
cross the forecast area late tomorrow morning into the afternoon
hours. Dynamics aren`t impressive and moisture transport is narrow
as it crosses the region, so continued to keep shower chances in the
20-40 percent range, mostly in the afternoon hours. We should warm
up nicely ahead of this system, topping out in the low to mid 60s
with steady south winds 10-20 mph.
.LONG TERM (Wednesday Night through Monday)...
Issued at 250 PM EST Tue Dec 15 2015
Wednesday Night - Thursday
The cold front will slow down Wednesday night as it crosses the
region, stalling somewhat over eastern Kentucky while a southern
stream impulse lifts more moisture back to the north. More
widespread rain will then overspread east of I-65, especially along
the I-75 corridor through the Thursday morning commute. Plan on lows
to range from the mid 30s west of I-65, to the low/mid 40s along the
I-75 corridor under deeper clouds and rain. Precipitation should
quickly end west to east Thursday morning.
A digging upper trough will bring seasonably cold air into the
region, as seen by crashing 850 mb temperatures throughout the day.
Temperatures won`t rise too much or even remain steady, especially
in our northwest. Highs in the mid 40s to low 50s.
Friday - Friday Night
The bulk of the cold airmass will be overhead during this time frame
as the upper trough axis swings through the lower Great Lakes into
the mid-Atlantic regions. A quick moving shortwave will round the
base of the trough. As the case with these clippers, moisture is
limited but some of that moisture does lie within the dendritic
growth zone /-10 to -15C/. A flurry or sprinkle, depending on
boundary layer temps, is possible across the northern forecast area,
say from Louisville metro and points east/north. Plan on highs in
the mid 30s to low 40s, and lows Friday night solidly in the 20s.
Saturday - Sunday
A dry and seasonable weekend is expected over the region. After a
slow start, temperatures will warm to the low and mid 40s on
Saturday under sunny skies. Surface high pressure moves east by
Saturday night, with light southerly flow returning.
This sets up our typical ridge/valley split nights where eastern
decoupled valleys stay in the low and mid 20s. Elsewhere, mixed
locations will see upper 20s to around 30. Milder conditions return
for Sunday under a steady south flow. Look for highs in the lower
50s.
Monday - Tuesday
A more active weather pattern is looking increasingly likely over
the area next week as a series of impulses lift out of the Plains to
the Great Lakes. Synoptically, a trough out west with ridging over
the east will favor above normal temperatures and chances of rain.
&&
.AVIATION (00Z TAF Update)...
Updated at 615 PM EST Tue Dec 15 2015
A mostly VFR TAF is expected as we sit in between weather systems
for much of the TAF period. We`ll see an increase in upper level
clouds late tonight with a brief period of MVFR br possible at BWG
toward sunrise. For tomorrow, southerly winds will pick up ahead of
a cold front gusting into the 18-22 kt range especially during the
afternoon hrs. Some light showery activity along the front will
affect the BWG/SDF sites near the end of this TAF period. Behind
the front, MVFR cigs are possible for tomorrow night with winds
veering to the west.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Short Term........ZT
Long Term.........ZT
Aviation..........AMS
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1147 AM CST MON DEC 14 2015
.UPDATE...
Issued at 1142 AM CST MON DEC 14 2015
For aviation section only.&&
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 1142 AM CST MON DEC 14 2015
MVFR cigs 2k-3kft will gradually raise to VFR during the
afternoon..then skies should clear this evening. Gusty ssw winds
20-30 KTS will gradually diminish late in the day.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...GM
SHORT TERM...DB
LONG TERM...JP
AVIATION...GM
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
634 AM CST MON DEC 14 2015
.UPDATE...
Issued at 634 AM CST MON DEC 14 2015
Updated aviation discussion only.
&&
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 634 AM CST MON DEC 14 2015
Southwesterly winds are expected to kick up above 30 kts in gusts
for a few hours during the daylight hours today, first in the west
by mid morning, then in the east by early afternoon. Winds will
diminish to below 10 kts after midnight. Expect MVFR cigs through
mid afternoon, with some intervals of VFR cigs possible, after which
cigs will rise to VFR or just under. Though there are still some
scattered light showers possible through mid afternoon, they are not
expected to reduce vsbys significantly.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DB
LONG TERM...JP
AVIATION...DB
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
411 AM CST MON DEC 14 2015
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 410 AM CST MON DEC 14 2015
Aside from strong southwesterly winds during the daylight hours
today, expect MVFR cigs through mid afternoon, after which cigs
will rise to VFR. MVFR vsbys in rain are still possible through
sunrise in the east. Though there are still some scattered showers
possible through mid afternoon, they are not expected to reduce
vsbys significantly.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DB
LONG TERM...JP
AVIATION...DB
AREA FORECAST DISCUSSION
NWS JACKSON KY
400 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
THIS MORNING WE ARE TRACKING A LINE OF SHOWERS AND GUSTY WINDS
ACROSS WESTERN KY AND THIS WILL BE THE PRIMARY WEATHER MAKER FOR
THE SHORT TERM PERIOD. THIS IS ASSOCIATED WITH A COLD FRONT THAT
IS STRETCHED FROM SE IA...WESTERN KY...TO THE GULF OF MEXICO AT
06Z. THAT SAID WINDS LOOK TO BE THE MAIN CONCERN OVERALL WITH THIS
SYSTEM AND THESE SHOWERS HAVE THE ABILITY TO MIX DOWN STRONGER JET
ALOFT. VAD WIND PROFILE THIS MORNING INDICATING 40 KNOTS AT 4000
FT ABOVE THE RADAR THIS MORNING. ALL THIS SAID NOT CONFIDENT WE
WILL MIX DOWN WIND ADVISORY CRITERIA AREA WIDE...BUT MORE
CONFIDENT WE COULD 35 GUSTS PARTICULARLY ALONG THE MAIN LINE OF
SHOWERS. THEREFORE WILL ISSUE A LAKE WIND ADVISORY 12Z TO 00Z
TODAY. WHILE THE MORE WIND SPREAD GUSTS OF 35 MPH WILL OCCUR RIGHT
ALONG THE FRONT...THINK WE COULD STILL SEE GUSTY WINDS LATER IN
THE DAY. MATTER OF FACT BUFKIT SOUNDINGS AT EKQ ARE MIXING THE
DEEPEST AND THEREFORE HAVE GUSTS CERTAINLY POTENTIALLY MEETING OR
EXCEEDING LAKE WIND CRITERIA THIS AFTERNOON MAINLY ACROSS THE
BLUEGRASS AND LAKE CUMBERLAND REGIONS. OVERALL MESO MODELS TREND
THIS LINE OF SHOWERS DOWN AS IS MOVES INTO THE REGION THIS
MORNING...BUT KEPT CLOSE TO THE PREVIOUS WITH MINOR ADJUSTMENTS TO
TIMING SINCE THINKING ALL PORTIONS WILL MEASURE. AMOUNTS ARE STILL
EXPECTED TO REMAIN GENERALLY LESS THAN A HALF OF A INCH.
NOW TONIGHT THE BIGGEST CONCERN THAT REMAINS IS HOW MUCH CLOUD
COVER WE WILL SEE. SOME OF THE MODEL SOUNDINGS WOULD SUGGEST WE
BUILD DOWN SOME STRATUS LATER TONIGHT. KEPT THE BETTER COVERAGE
ACROSS THE NORTH CLOSER TO THE SURFACE LOW. THIS WILL HAVE
IMPLICATIONS ON LOWS...BUT EITHER WAY A SHIFT TO MORE WESTERLY
WIND DIRECTION SHOULD INTRODUCE MUCH COOLER AIR THAN WE HAVE SEEN
THE PAST FEW NIGHTS. THAT SAID LOWS LOOK TO DROP INTO THE MID TO
UPPER 40S. NOW LOOKS LIKE WE WILL SEE CLEARING SKIES ON TUESDAY
AS BROAD SURFACE HIGH BUILDS EAST. WHILE WE SEE COOLER AIR BEHIND
THIS SYSTEM THE MORE WINTER SEASON AIR REMAINS LOCKED UP WELL
NORTH OF THE REGION. HIGHS ON TUESDAY ARE EXPECTED TO CLIMB INTO
THE UPPER 50S TO LOWER 60S WITH AROUND 10 PLUS DEGREES HIGHER THAN
NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 AM EST MON DEC 14 2015
MODELS ARE IN GOOD AGREEMENT FOR THE OVERALL PICTURE DURING THE
PERIOD. HIGH PRESSURE WILL MOVE AWAY TO OUR EAST TUESDAY NIGHT AND
WEDNESDAY...WITH A BRIEF WARM-UP OCCURRING. A COLD FRONT WILL MOVE
THROUGH FROM WEST TO EAST LATE WEDNESDAY NIGHT AND EARLY THURSDAY.
IT WILL BE ASSOCIATED WITH A SIGNIFICANT PROGRESSIVE LONGWAVE
TROUGH. A WAVE SHOULD DEVELOP ON THE FRONT NEAR THE GULF COAST AND
MOVE NORTHEAST ON THE EAST SIDE OF THE APPALACHIANS. RAIN FROM THIS
WAVE IS EXPECTED TO MAKE IT AS FAR NORTHWEST AS KY LATE WEDNESDAY
NIGHT INTO THURSDAY...BUT EXACTLY HOW FAR NORTHWEST AND HOW HEAVY
ARE BOTH STILL IN QUESTION. COLD AIR WILL CONTINUE TO POUR INTO THE
REGION AS THE WAVE AND FRONT DEPART. THE UPPER LEVEL TROUGH AXIS IS
FORECAST TO PASS OVER ON FRIDAY. SNOW OR RAIN SHOWERS MAY DEVELOP
UNDER THE TROUGH...AIDED BY UPSLOPE COLD AIR ADVECTION. HAVE CARRIED
A 20 PERCENT POP IN OUR EASTERN AND SOUTHEASTERN COUNTIES. DRYING
THEN ARRIVES FOR THE WEEKEND. COMPARED TO RECENT CONDITIONS...VERY
COLD AIR WILL BE IN PLACE BY THE WEEKEND...WITH TEMPERATURES
FORECAST IN THE TEENS IN VALLEYS BY SUNDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS
EVENING FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-
106>120.
&&
$$
SHORT TERM...DJ
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
322 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
THIS MORNING WE ARE TRACKING A LINE OF SHOWERS AND GUSTY WINDS
ACROSS WESTERN KY AND THIS WILL BE THE PRIMARY WEATHER MAKER FOR
THE SHORT TERM PERIOD. THIS IS ASSOCIATED WITH A COLD FRONT THAT
IS STRETCHED FROM SE IA...WESTERN KY...TO THE GULF OF MEXICO AT
06Z. THAT SAID WINDS LOOK TO BE THE MAIN CONCERN OVERALL WITH THIS
SYSTEM AND THESE SHOWERS HAVE THE ABILITY TO MIX DOWN STRONGER JET
ALOFT. VAD WIND PROFILE THIS MORNING INDICATING 40 KNOTS AT 4000
FT ABOVE THE RADAR THIS MORNING. ALL THIS SAID NOT CONFIDENT WE
WILL MIX DOWN WIND ADVISORY CRITERIA AREA WIDE...BUT MORE
CONFIDENT WE COULD 35 GUSTS PARTICULARLY ALONG THE MAIN LINE OF
SHOWERS. THEREFORE WILL ISSUE A LAKE WIND ADVISORY 12Z TO 00Z
TODAY. WHILE THE MORE WIND SPREAD GUSTS OF 35 MPH WILL OCCUR RIGHT
ALONG THE FRONT...THINK WE COULD STILL SEE GUSTY WINDS LATER IN
THE DAY. MATTER OF FACT BUFKIT SOUNDINGS AT EKQ ARE MIXING THE
DEEPEST AND THEREFORE HAVE GUSTS CERTAINLY POTENTIALLY MEETING OR
EXCEEDING LAKE WIND CRITERIA THIS AFTERNOON MAINLY ACROSS THE
BLUEGRASS AND LAKE CUMBERLAND REGIONS. OVERALL MESO MODELS TREND
THIS LINE OF SHOWERS DOWN AS IS MOVES INTO THE REGION THIS
MORNING...BUT KEPT CLOSE TO THE PREVIOUS WITH MINOR ADJUSTMENTS TO
TIMING SINCE THINKING ALL PORTIONS WILL MEASURE. AMOUNTS ARE STILL
EXPECTED TO REMAIN GENERALLY LESS THAN A HALF OF A INCH.
NOW TONIGHT THE BIGGEST CONCERN THAT REMAINS IS HOW MUCH CLOUD
COVER WE WILL SEE. SOME OF THE MODEL SOUNDINGS WOULD SUGGEST WE
BUILD DOWN SOME STRATUS LATER TONIGHT. KEPT THE BETTER COVERAGE
ACROSS THE NORTH CLOSER TO THE SURFACE LOW. THIS WILL HAVE
IMPLICATIONS ON LOWS...BUT EITHER WAY A SHIFT TO MORE WESTERLY
WIND DIRECTION SHOULD INTRODUCE MUCH COOLER AIR THAN WE HAVE SEEN
THE PAST FEW NIGHTS. THAT SAID LOWS LOOK TO DROP INTO THE MID TO
UPPER 40S. NOW LOOKS LIKE WE WILL SEE CLEARING SKIES ON TUESDAY
AS BROAD SURFACE HIGH BUILDS EAST. WHILE WE SEE COOLER AIR BEHIND
THIS SYSTEM THE MORE WINTER SEASON AIR REMAINS LOCKED UP WELL
NORTH OF THE REGION. HIGHS ON TUESDAY ARE EXPECTED TO CLIMB INTO
THE UPPER 50S TO LOWER 60S WITH AROUND 10 PLUS DEGREES HIGHER THAN
NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
AVAILABLE SHORTLY...
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1256 AM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 1256 AM EST MON DEC 14 2015
SEEING QUITE THE TEMP SLITS ACROSS THE REGION THIS EVENING WITH
MANY OF THE VALLEY LOCATIONS ABLE TO DECOUPLE. RIGHT NOW JKL IS
SITTING AT 63 DEGREES...MEAN WHILE DOWN THE VALLEY AT QUICKSAND
MESONET WE ARE SEEING 47 DEGREES. WHILE WINDS HAVE BEGUN TO COME
UP THE ONLY AREAS REALLY RESPONDING THIS HOUR ARE DORT AND BLK MTN
WHICH ARE OUR HIGHER LOCATIONS AND TYPICAL WINDY SPOTS. RIGHT NOW
WILL KEEP WITH SPS HIGHLIGHTING THE WINDS AND LOOK AT THIS DEEPER
WITH PACKAGE UPDATE.
UPDATE ISSUED AT 946 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE INCREASING WINDS ALOFT
AND EXTENSIVE CLOUD COVER AS THE FRONT APPROACHES THE AREA. THE
OVERALL FORECAST LOOKS TO BE ON TRACK AND THE ONLY TWEAK NEEDED IS
TO UPDATE HOURLY TEMPS AND DEW POINTS.
UPDATE ISSUED AT 730 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE CLOUD COVER ON
THE INCREASE AS A COLD FRONT DEVELOPS AND MOVES EAST. THIS HAS
RESULTED IN AN INCREASE IN SOUTHERLY FLOW AS THE GRADIENT
INCREASES. IN FACT...40 KNOT WINDS ARE ALREADY OVERHEAD AS THE
SYSTEM APPROACHES. HAVE INCREASED CLOUD COVER OVER THE AREA AS
MID AND UPPER LEVEL CLOUD COVER IS ON THE INCREASE. IN
ADDITION...WITH A BIT MORE INDICATION OF 30 KNOT WINDS MAKING IT
TO THE SURFACE...HAVE ISSUED AN SPS TO HIGHLIGHT THE WIND THREAT.
STILL AS IS USUALLY THE CASE...THIS FRONT WILL WEAKEN AS IT MOVES
INTO THE AREA AND THE 40 KNOT WINDS MAKING IT TO THE SURFACE OUT
WEST WILL NOT BE THE CASE HERE IN EAST KENTUCKY. HI RES
MODELS...INDICATE A WEAKENING TREND TO THE LINE OF SHOWERS SO THE
STRONGER WIND GUSTS ARE NOT EXPECTED. THE REST OF THE FORECAST
REMAINS ON TRACK BUT WILL ISSUE A NEW ZFP FOR THESE CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 223 PM EST SUN DEC 13 2015
HIGH CLOUDS HAVE REALLY KEPT TEMPERATURES FROM WARMING AS MUCH AS
THEY COULD HAVE...BUT TEMPERATURES HAVE STILL MANAGED TO REACH
RECORD LEVELS WITH MOST AREAS TOPPING OUT RIGHT AROUND 70.
FORECAST CONCERNS FOR THE SHORT TERM WILL FOCUS ON WIND AND RAIN
POTENTIAL AS A COLD FRONT PUSHES ON THROUGH FROM AROUND DAYBREAK
MONDAY INTO MIDDAY MONDAY.
A SHORTWAVE TROUGH WILL PUSH INTO THE GREAT LAKES BY MONDAY
MORNING...SENDING THE COLD FRONT ACROSS KENTUCKY. THE BETTER
FORCING AND DYNAMICS ARE EXPECTED TO SLIDE TO THE NORTH...BUT
STILL EXPECTING A BAND OF SHOWERS TO PUSH ON THROUGH EASTERN
KENTUCKY WITH THE FRONT. SHOWERS MAY BE WEAKENING AS THEY CROSS
THE AREA AND ENCOUNTER A MORE HOSTILE ENVIRONMENT WITH DOWNSLOPING
WINDS OFF THE HIGHER TERRAIN. REGARDLESS...IT APPEARS MOST AREAS
SHOULD SEE SOME RAINFALL FROM THIS FRONT...SO WILL MAINTAIN THE
CATEGORICAL POPS. HAVE CONTINUED TO SLOW DOWN THE BEST POPS AS
MOST OF THE RAIN SHOULD COME IN OUR AREA AFTER 12Z. ANOTHER
DIFFICULT TEMPERATURE FORECAST TONIGHT...AS SOME OF THE DEEPER
EASTERN VALLEYS COULD BRIEFLY DECOUPLE AND SEND THEIR TEMPERATURES
DOWN WELL INTO THE 50S...WHILE RIDGES AND AREAS THAT STAY MIXED
COULD STAY IN THE 60S. REGARDLESS...EXPECT QUITE A SPREAD IN
TEMPERATURES OVERNIGHT...BUT STILL VERY MILD FOR THIS TIME OF
YEAR. CLOUD COVER AND RAIN SHOULD KEEP TEMPERATURES FROM RISING
MUCH ON MONDAY...BUT WE COULD SEE A BRIEF UPTICK IN TEMPERATURES
LATE IN THE DAY AS CLOUDS TRY TO BREAK UP. THERE IS A SECONDARY
WAVE THAT WILL CROSS THE OHIO RIVER VALLEY THROUGH THE EVENING
HOURS AND COULD SPIT OUT A FEW SPRINKLES...BUT SHOULD NOT BE A BIG
DEAL.
MAIN CONCERN ON MONDAY WILL BE AROUND THE WIND POTENTIAL. 12 MODELS
HAVE TRENDED UP SLIGHTLY WITH THE WIND POTENTIAL FROM THE 00Z
RUN...BUT ONLY SLIGHTLY. 12Z NAM/GFS BUFKIT SOUNDINGS SUPPORT WIND
GUSTS REACHING 30 TO 35 MPH...WHICH IS BORDERLINE LAKE WIND
ADVISORY CRITERIA FOR EASTERN KENTUCKY. THE STRONGEST WINDS SHOULD
ARRIVE POST FRONTAL...BUT CONFIDENCE STILL REMAINS LOW ON EXACTLY
HOW MUCH WIND CAN MIX DOWN BEHIND THE FRONT. GIVEN ITS STILL THE
SECOND PERIOD...OPTING TO HOLD OFF ON ANY HEADLINES AND LET
EVENING OR MIDNIGHT SHIFT REEVALUATE THE NEED FOR ANY HEADLINES.
WILL CARRY SOME GUSTY WIND POTENTIAL IN THE HWO FOR MONDAY.
STILL LOTS OF UNCERTAINTY REGARDING CLOUD COVER FOR MONDAY
NIGHT. 12Z NAM IS FAIRLY AGGRESSIVE IN KEEPING CLOUDS AROUND
OVERNIGHT...WHILE GFS AND ECMWF HAVE MUCH LESS CLOUD COVER. OPTING
TO CONTINUE TO GO PARTLY TO MOSTLY CLOUDY FOR NOW...BUT ITS VERY
POSSIBLE IT EITHER ENDS UP OVERCAST OR MOSTLY CLEAR. LOWS MONDAY
NIGHT WILL BE MUCH COOLER WITH READINGS SETTLING BACK INTO THE
40S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN DEC 13 2015
THE EXTENDED PERIOD WILL START OUT DRY WITH AN UPPER LEVEL RIDGE
SITUATED OVER KENTUCKY TUESDAY AND WEDNESDAY. BY WEDNESDAY
EVENING...A DEEP UPPER LEVEL TROUGH WILL REACH THE WESTERN GREAT
LAKES. THIS SYSTEM WILL DRIVE A COLD FRONT THROUGH THE OHIO VALLEY
EARLY THURSDAY BUT WILL HAVE A TOUGH TIME TAPPING INTO MOISTURE.
THERE ARE STILL SOME DIFFERENCES BETWEEN THE GFS AND ECMWF WITH
TIMING AND AMOUNT OF PRECIP WHICH STEM FROM THE UPPER LEVEL TROUGH
AMPLIFICATION DIFFERENCES. HOWEVER...IT IS LIKELY THAT WE WILL
SEE SOME SHOWERS THURSDAY MORNING BUT MAY NOT AMOUNT TO MUCH OR BE
WIDESPREAD. THAT BEING SAID...WILL STICK CLOSE TO THE CR
SUPERBLEND AND KEEP CHANCE POPS IN THE FORECAST.
BROAD UPPER LEVEL TROUGHINESS WILL LINGER OVER THE EASTERN CONUS
THROUGH SUNDAY MORNING KEEPING THINGS MAINLY DRY WITH SOME CLOUDS.
THE ONLY EXCEPTION IS FOR SOME LIGHT QPF IN THE FORM OF RAIN/SNOW
SHOWERS ALONG THE KY/VA BORDER EARLY SATURDAY. THIS IS DUE TO A
STRONG UPPER LEVEL DISTURBANCE SWINGING THROUGH THE TROUGH. UNLIKE
THE MODEL RUNS YESTERDAY...BOTH THE GFS AND 00Z ECMWF NOW SUPPORT
THIS QPF SO HAVE DECIDED TO INCLUDE BRIEF SLIGHT CHANCE POPS.
HIGH PRESSURE BUILDS BACK INTO THE REGION ON SUNDAY.
ABOVE NORMAL TEMPERATURES ARE EXPECTED AT THE START OF THE PERIOD
BUT WILL DROP INTO THE 40S BY FRIDAY. THE WEEKEND LOOKS EVEN COLDER
AS HIGHS MAY STRUGGLE TO GET OUT OF THE 30S ON SATURDAY AND THEN
WILL BEGIN TO REBOUND LEADING INTO THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1244 AM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 946 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE INCREASING WINDS ALOFT
AND EXTENSIVE CLOUD COVER AS THE FRONT APPROACHES THE AREA. THE
OVERALL FORECAST LOOKS TO BE ON TRACK AND THE ONLY TWEAK NEEDED IS
TO UPDATE HOURLY TEMPS AND DEW POINTS.
UPDATE ISSUED AT 730 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE CLOUD COVER ON
THE INCREASE AS A COLD FRONT DEVELOPS AND MOVES EAST. THIS HAS
RESULTED IN AN INCREASE IN SOUTHERLY FLOW AS THE GRADIENT
INCREASES. IN FACT...40 KNOT WINDS ARE ALREADY OVERHEAD AS THE
SYSTEM APPROACHES. HAVE INCREASED CLOUD COVER OVER THE AREA AS
MID AND UPPER LEVEL CLOUD COVER IS ON THE INCREASE. IN
ADDITION...WITH A BIT MORE INDICATION OF 30 KNOT WINDS MAKING IT
TO THE SURFACE...HAVE ISSUED AN SPS TO HIGHLIGHT THE WIND THREAT.
STILL AS IS USUALLY THE CASE...THIS FRONT WILL WEAKEN AS IT MOVES
INTO THE AREA AND THE 40 KNOT WINDS MAKING IT TO THE SURFACE OUT
WEST WILL NOT BE THE CASE HERE IN EAST KENTUCKY. HI RES
MODELS...INDICATE A WEAKENING TREND TO THE LINE OF SHOWERS SO THE
STRONGER WIND GUSTS ARE NOT EXPECTED. THE REST OF THE FORECAST
REMAINS ON TRACK BUT WILL ISSUE A NEW ZFP FOR THESE CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 223 PM EST SUN DEC 13 2015
HIGH CLOUDS HAVE REALLY KEPT TEMPERATURES FROM WARMING AS MUCH AS
THEY COULD HAVE...BUT TEMPERATURES HAVE STILL MANAGED TO REACH
RECORD LEVELS WITH MOST AREAS TOPPING OUT RIGHT AROUND 70.
FORECAST CONCERNS FOR THE SHORT TERM WILL FOCUS ON WIND AND RAIN
POTENTIAL AS A COLD FRONT PUSHES ON THROUGH FROM AROUND DAYBREAK
MONDAY INTO MIDDAY MONDAY.
A SHORTWAVE TROUGH WILL PUSH INTO THE GREAT LAKES BY MONDAY
MORNING...SENDING THE COLD FRONT ACROSS KENTUCKY. THE BETTER
FORCING AND DYNAMICS ARE EXPECTED TO SLIDE TO THE NORTH...BUT
STILL EXPECTING A BAND OF SHOWERS TO PUSH ON THROUGH EASTERN
KENTUCKY WITH THE FRONT. SHOWERS MAY BE WEAKENING AS THEY CROSS
THE AREA AND ENCOUNTER A MORE HOSTILE ENVIRONMENT WITH DOWNSLOPING
WINDS OFF THE HIGHER TERRAIN. REGARDLESS...IT APPEARS MOST AREAS
SHOULD SEE SOME RAINFALL FROM THIS FRONT...SO WILL MAINTAIN THE
CATEGORICAL POPS. HAVE CONTINUED TO SLOW DOWN THE BEST POPS AS
MOST OF THE RAIN SHOULD COME IN OUR AREA AFTER 12Z. ANOTHER
DIFFICULT TEMPERATURE FORECAST TONIGHT...AS SOME OF THE DEEPER
EASTERN VALLEYS COULD BRIEFLY DECOUPLE AND SEND THEIR TEMPERATURES
DOWN WELL INTO THE 50S...WHILE RIDGES AND AREAS THAT STAY MIXED
COULD STAY IN THE 60S. REGARDLESS...EXPECT QUITE A SPREAD IN
TEMPERATURES OVERNIGHT...BUT STILL VERY MILD FOR THIS TIME OF
YEAR. CLOUD COVER AND RAIN SHOULD KEEP TEMPERATURES FROM RISING
MUCH ON MONDAY...BUT WE COULD SEE A BRIEF UPTICK IN TEMPERATURES
LATE IN THE DAY AS CLOUDS TRY TO BREAK UP. THERE IS A SECONDARY
WAVE THAT WILL CROSS THE OHIO RIVER VALLEY THROUGH THE EVENING
HOURS AND COULD SPIT OUT A FEW SPRINKLES...BUT SHOULD NOT BE A BIG
DEAL.
MAIN CONCERN ON MONDAY WILL BE AROUND THE WIND POTENTIAL. 12 MODELS
HAVE TRENDED UP SLIGHTLY WITH THE WIND POTENTIAL FROM THE 00Z
RUN...BUT ONLY SLIGHTLY. 12Z NAM/GFS BUFKIT SOUNDINGS SUPPORT WIND
GUSTS REACHING 30 TO 35 MPH...WHICH IS BORDERLINE LAKE WIND
ADVISORY CRITERIA FOR EASTERN KENTUCKY. THE STRONGEST WINDS SHOULD
ARRIVE POST FRONTAL...BUT CONFIDENCE STILL REMAINS LOW ON EXACTLY
HOW MUCH WIND CAN MIX DOWN BEHIND THE FRONT. GIVEN ITS STILL THE
SECOND PERIOD...OPTING TO HOLD OFF ON ANY HEADLINES AND LET
EVENING OR MIDNIGHT SHIFT REEVALUATE THE NEED FOR ANY HEADLINES.
WILL CARRY SOME GUSTY WIND POTENTIAL IN THE HWO FOR MONDAY.
STILL LOTS OF UNCERTAINTY REGARDING CLOUD COVER FOR MONDAY
NIGHT. 12Z NAM IS FAIRLY AGGRESSIVE IN KEEPING CLOUDS AROUND
OVERNIGHT...WHILE GFS AND ECMWF HAVE MUCH LESS CLOUD COVER. OPTING
TO CONTINUE TO GO PARTLY TO MOSTLY CLOUDY FOR NOW...BUT ITS VERY
POSSIBLE IT EITHER ENDS UP OVERCAST OR MOSTLY CLEAR. LOWS MONDAY
NIGHT WILL BE MUCH COOLER WITH READINGS SETTLING BACK INTO THE
40S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN DEC 13 2015
THE EXTENDED PERIOD WILL START OUT DRY WITH AN UPPER LEVEL RIDGE
SITUATED OVER KENTUCKY TUESDAY AND WEDNESDAY. BY WEDNESDAY
EVENING...A DEEP UPPER LEVEL TROUGH WILL REACH THE WESTERN GREAT
LAKES. THIS SYSTEM WILL DRIVE A COLD FRONT THROUGH THE OHIO VALLEY
EARLY THURSDAY BUT WILL HAVE A TOUGH TIME TAPPING INTO MOISTURE.
THERE ARE STILL SOME DIFFERENCES BETWEEN THE GFS AND ECMWF WITH
TIMING AND AMOUNT OF PRECIP WHICH STEM FROM THE UPPER LEVEL TROUGH
AMPLIFICATION DIFFERENCES. HOWEVER...IT IS LIKELY THAT WE WILL
SEE SOME SHOWERS THURSDAY MORNING BUT MAY NOT AMOUNT TO MUCH OR BE
WIDESPREAD. THAT BEING SAID...WILL STICK CLOSE TO THE CR
SUPERBLEND AND KEEP CHANCE POPS IN THE FORECAST.
BROAD UPPER LEVEL TROUGHINESS WILL LINGER OVER THE EASTERN CONUS
THROUGH SUNDAY MORNING KEEPING THINGS MAINLY DRY WITH SOME CLOUDS.
THE ONLY EXCEPTION IS FOR SOME LIGHT QPF IN THE FORM OF RAIN/SNOW
SHOWERS ALONG THE KY/VA BORDER EARLY SATURDAY. THIS IS DUE TO A
STRONG UPPER LEVEL DISTURBANCE SWINGING THROUGH THE TROUGH. UNLIKE
THE MODEL RUNS YESTERDAY...BOTH THE GFS AND 00Z ECMWF NOW SUPPORT
THIS QPF SO HAVE DECIDED TO INCLUDE BRIEF SLIGHT CHANCE POPS.
HIGH PRESSURE BUILDS BACK INTO THE REGION ON SUNDAY.
ABOVE NORMAL TEMPERATURES ARE EXPECTED AT THE START OF THE PERIOD
BUT WILL DROP INTO THE 40S BY FRIDAY. THE WEEKEND LOOKS EVEN COLDER
AS HIGHS MAY STRUGGLE TO GET OUT OF THE 30S ON SATURDAY AND THEN
WILL BEGIN TO REBOUND LEADING INTO THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...KAS
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1049 PM EST TUE DEC 15 2015
.UPDATE...
ISSUED AT 1043 PM EST TUE DEC 15 2015
UPPER LOW OVER NEB CAUSING SNOW FM THE DAKOTAS INTO WESTERN NEB. SFC
LOW IS OVER SCNTRL NEB. SE UPSLOPE FLOW AHEAD OF THE LOW IS LEADING
TO LGT SNOW/FLURRIES OVER HIGHER TERRAIN OF CNTRL UPR MICHIGAN ATTM.
MAY SEE DZ/FZDZ LATER TONIGHT OVER INTERIOR WEST HALF THOUGH WITH
SNOW PTYPE ATTM WITH TEMPS IN MOIST LAYER ONLY FCST TO BE AROUND
-5C...MIGHT JUST END UP SNOW OVER UPSLOPE AREAS OF CNTRL UPR MICHIGAN
IMT TO NEGAUNEE.
MAIN CONCERN IS PTYPE LATE TONIGHT OVER WEST CWA VCNTY OF KIWD.
ISENTROPIC ASCENT AHEAD OF LOW SHOULD LEAD TO LGT PRECIP SPREADING
IN FM SW. SEEING INITIAL SIGNS OF THIS DEVELOPMENT OVER WESTERN IA TO
CNTRL MN. SHOULD BE MORE OF A DZ/FZDZ INITIALLY BUT AS LIFT INCREASES
PER INCREASING DEEP LAYER Q-VECTOR CONVERGENCE THERE WILL BE ENOUGH
DEEP MOISTURE TO INTRO ICE ALOFT...LEADING TO STEADIER PRECIP. RAP
AND NAM INDICATE WARM NOSE AT H85 AS WARM AS +4C WHICH MAKES SENSE
BASED ON SHARP WARMING IN H85 LAYER SEEN ON 00Z MPX SOUNDING.
THUS...EXPECT PTYPE TO BE LIQUID OR POSSIBLY SLEET LATE TONIGHT AT
KIWD DUE TO COOLING BLO THE WARM NOSE TO THE SFC. AS BLYR WINDS TURN
MORE SE...EXPECT AIRMASS CURRENTLY OVER LK MICHIGAN/EASTERN WI/LOWER
MICHIGAN TO ADVECT IN...PUSHING SFC TEMPS ABOVE FREEZING. ALL MODELS
SHOWING THIS AND ONLY TIME WILL TELL IF THEY ARE ON RIGHT TRACK. IF
COOLING IS SLOWER TO DEVELOP...COULD BE A BRIEF PERIOD OF MAINLY FZRA
AT KIWD LATE TONIGHT. EVEN IF AIR TEMPS RISE TO 33-35...ROAD TEMPS CLEAR
OF SNOW MAY BE MORE AROUND 30 BASED ON LATEST READINGS FM MDOT. SHARPEST
WARM AIR INTRUSION IS PRETTY ISOLATED TO WESTERN UPR MICHIGAN THOUGH
AND DO NOT HAVE TO GO MUCH FARTHER NORTH OR EAST FOR STEADIER PRECIP
IN THE MORNING TO LIKELY START AS SNOW/SLEET BEFORE IT CHANGES OVER
TO RAIN BY LATE MORNING.
WAY TOO MUCH UNCERTAINTY IN BOTH EXTENT OF PRECIP AND PTYPE TO ISSUE
A WINTER WEATHER ADVY HEADLINE ATTM. MORE OF A NEAR TERM FORECAST
ISSUE THAT MID SHIFT WILL BE MONITORING. DID RE ISSUE THE SPECIAL
WEATHER STATEMENT AND ALSO HIT UP SOCIAL MEDIA MENTIONING SLIPPERY
CONDITIONS POSSIBLE FOR THE MORNING COMMUTE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE DEC 15 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITHA
A TROUGH IN THE WRN CONUS THROUGH THE ROCKIES INTO THE PLAINS AND A
RIDGE FROM THE SE INTO THE GREAT LAKES. THE MAIN UPSTREAM FEATURE IS
THE MID LEVEL LOW OVER SW NEBRASKA. AT THE SFC...ERLY FLOW PREVAILED
BTWN HIGH PRES OVER NRN ONTARIO AND THE SFC LOW OVER NW KS. DRIER
AIR FROM EAST OF LAKE SUPERIOR HAS HELPED SCOUR OUT THE LOWER CLOUDS
OVER THE ERN CWA AND HAS HELPED BRING AN END TO THE UPSLOPE LES INTO
N CNTRL UPPER MI.
TONIGHT...AS THE CNTRL PLAINS LOW LIFTS NE TO NEAR NW IA...SE LOW
LEVEL FLOW WILL INCREASE ACROSS THE CWA. THE COMBINATION OF 285K-
290K ISENTROPIC LIFT AND LOW LEVEL MOIST FLOW OFF OF LAKE MI WILL
SUPPORT INCREASING PCPN CHANCES LATE TONIGHT. WITH THE MOIST LAYER
EXTENDING ONLY TO AROUND -5C...MAINLY DZ/FZDZ IS EXPECTED. TEMPS
CLIMBING ABOVE FREEZING LATE TONIGHT SHOULD HELP MINIMIZE POTENTIAL
FOR FREEZING PCPN.
WEDNESDAY...AS THE MID LEVEL MOVES THROUGH CNTRL MN...A PERIOD OF
MODERATE TO STRONG 700-300 MB QVECTOR CONV WITH A BAND OF DEEPER
MOISTURE WILL SUPPORT LIKELY POPS ACROSS THROUGH THE AREA BTWN 15Z-
21Z. TEMPS IN THE ANTECDENT MID LEVEL DRY LAYER WILL DROP ENOUGH
WITH EVAPORATIVE COOLING TO SUPPORT SNOW. HOWEVER...EXPECT A DEEP
ENOUGH SFC WARM LAYER FOR MAINLY RAIN OVER MOST OF THE CWA EXCEPT
THE HIGHER TERRAIN IN THE WEST HALF. EVEN WITH QPF IN THE 0.15 TO
0.25 INCH RANGE...THE WARM SFC CONDITIONS IN THE MID 30S SHOULD
LIMIT ANY ACCUMULATIONS TO LESS THAN AN INCH. THE PCPN MAY REVERT
BACK TO DRIZZLE AS THE DEEPER MOISTURE MOVES OUT FROM WEST TO EAST
LATER IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 539 PM EST TUE DEC 15 2015
AT 00Z THU...A ROUGHLY 990MB SFC LOW AND CO-LOCATED UPPER LOW WILL
BE OVER WRN LAKE SUPERIOR OR JUST NW OF THE CWA. COLD AIR WILL BE
ADVECTING INTO THE AREA FROM THE SW...WITH 850MB TEMPS NEAR OR BELOW
0C BY 00Z THU AND WELL UNDER 0C BY 06Z THU. THE DRY SLOT WILL KEEP
SIGNIFICANT SNOWFALL AMOUNTS FROM OCCURING WED NIGHT...BUT WILL SEE
AN INCREASE IN LES IN WSW-W WIND SNOWBELTS LATE WED NIGHT THROUGH
THU...BECOMING LIKELY BY THU AFTERNOON AS 850MB TEMPS DROP BELOW
-10C. LES WILL PEAK THU NIGHT INTO FRI AS AN UPPER TROUGH MOVES
THROUGH AND 850MB TEMPS DROP TO AOB -15C. THIS WILL LEAD TO
INVERSION HEIGHTS AROUND 9-10KFT AND LIFT FAVORABLY LOCATED IN THE
DGZ...PROMOTING MODERATE TO POTENTIALLY HEAVY LES. LOW LEVEL WIND
DIRECTIONS REMAIN IN QUESTION...WITH MODEL SOLUTIONS BETWEEN WSW AND
WNW...WHICH MAKES LES POTENTIAL UNCERTAIN FOR EASTERN LES AREAS OF
ERN ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES. ALL MODELS DO SHOW
WINDS TURNING WNW-NW BY LATE FRI EVENING AND LASTING THROUGH MUCH OF
SAT BEFORE A SFC RIDGE MOVES THROUGH. STILL SEEMS THAT 1-2 SNOWFALL
AMOUNTS OF 8 PLUS INCHES IS LIKELY OVER THE W WIND SNOWBELTS. WILL
LIKELY NEED AN ADVISORY FOR THE KEWEENAW PENINSULA AREA AND WILL
CONTINUE TO HIGHLIGHT THE POTENTIAL FOR PLOW-ABLE SNOW IN THE HWO.
THE SNOW IS EXPECTED TO DIMINISH LATE SAT INTO SAT NIGHT AS DRY AIR
WITH A SURFACE RIDGE MOVES INTO THE AREA.
TEMPS LOOK TO WARM AGAIN EARLY TO MIDDLE OF NEXT WEEK...BUT WILL LET
CONSENSUS GUIDANCE POPULATE THAT PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 653 PM EST TUE DEC 15 2015
EAST TO SOUTHEAST WINDS BETWEEN A LOW PRESSURE SYSTEM MOVING FM THE
PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY AND HIGH PRESSURE OVER
HUDSON BAY WILL BRING STEADY STATE MVFR CIGS TONIGHT. CIGS LOWER
LATE TONIGHT INTO WED AS THE LOW REACHES MINNESOTA. A LIGHT WINTRY
MIX OF DRIZZLE AND SNOW WILL AFFECT THE TAF SITES LATE TONIGHT INTO
WED MORNING. EVENTUALLY ENOUGH WARM AIR MOVES IN TO CHANGE ANY MIXED
PRECIP TO RAIN BY THE AFTN. OVERALL FOR WED...EXPECT IFR CIGS AND
VSBY. LIFR CIGS BLO 500 FT SHOULD OCCUR AT KSAW LATER WED AFTN DUE
TO PERSISTENT UPSLOPE SE WINDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE DEC 15 2015
ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP AND SLIDE THROUGH THE UPPER
GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST GALES ARE EXPECTED
OVER THE WEST HALF THIS EVENING INTO WED MORNING AND SOUTHEAST WINDS
WILL REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE
LOW LATE TONIGHT THROUGH WEDNESDAY FOLLOWED BY WESTERLY WINDS
APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON THURSDAY
INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLA
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
654 PM EST TUE DEC 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE DEC 15 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITHA
A TROUGH IN THE WRN CONUS THROUGH THE ROCKIES INTO THE PLAINS AND A
RIDGE FROM THE SE INTO THE GREAT LAKES. THE MAIN UPSTREAM FEATURE IS
THE MID LEVEL LOW OVER SW NEBRASKA. AT THE SFC...ERLY FLOW PREVAILED
BTWN HIGH PRES OVER NRN ONTARIO AND THE SFC LOW OVER NW KS. DRIER
AIR FROM EAST OF LAKE SUPERIOR HAS HELPED SCOUR OUT THE LOWER CLOUDS
OVER THE ERN CWA AND HAS HELPED BRING AN END TO THE UPSLOPE LES INTO
N CNTRL UPPER MI.
TONIGHT...AS THE CNTRL PLAINS LOW LIFTS NE TO NEAR NW IA...SE LOW
LEVEL FLOW WILL INCREASE ACROSS THE CWA. THE COMBINATION OF 285K-
290K ISENTROPIC LIFT AND LOW LEVEL MOIST FLOW OFF OF LAKE MI WILL
SUPPORT INCREASING PCPN CHANCES LATE TONIGHT. WITH THE MOIST LAYER
EXTENDING ONLY TO AROUND -5C...MAINLY DZ/FZDZ IS EXPECTED. TEMPS
CLIMBING ABOVE FREEZING LATE TONIGHT SHOULD HELP MINIMIZE POTENTIAL
FOR FREEZING PCPN.
WEDNESDAY...AS THE MID LEVEL MOVES THROUGH CNTRL MN...A PERIOD OF
MODERATE TO STRONG 700-300 MB QVECTOR CONV WITH A BAND OF DEEPER
MOISTURE WILL SUPPORT LIKELY POPS ACROSS THROUGH THE AREA BTWN 15Z-
21Z. TEMPS IN THE ANTECDENT MID LEVEL DRY LAYER WILL DROP ENOUGH
WITH EVAPORATIVE COOLING TO SUPPORT SNOW. HOWEVER...EXPECT A DEEP
ENOUGH SFC WARM LAYER FOR MAINLY RAIN OVER MOST OF THE CWA EXCEPT
THE HIGHER TERRAIN IN THE WEST HALF. EVEN WITH QPF IN THE 0.15 TO
0.25 INCH RANGE...THE WARM SFC CONDITIONS IN THE MID 30S SHOULD
LIMIT ANY ACCUMULATIONS TO LESS THAN AN INCH. THE PCPN MAY REVERT
BACK TO DRIZZLE AS THE DEEPER MOISTURE MOVES OUT FROM WEST TO EAST
LATER IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 539 PM EST TUE DEC 15 2015
AT 00Z THU...A ROUGHLY 990MB SFC LOW AND CO-LOCATED UPPER LOW WILL
BE OVER WRN LAKE SUPERIOR OR JUST NW OF THE CWA. COLD AIR WILL BE
ADVECTING INTO THE AREA FROM THE SW...WITH 850MB TEMPS NEAR OR BELOW
0C BY 00Z THU AND WELL UNDER 0C BY 06Z THU. THE DRY SLOT WILL KEEP
SIGNIFICANT SNOWFALL AMOUNTS FROM OCCURING WED NIGHT...BUT WILL SEE
AN INCREASE IN LES IN WSW-W WIND SNOWBELTS LATE WED NIGHT THROUGH
THU...BECOMING LIKELY BY THU AFTERNOON AS 850MB TEMPS DROP BELOW
-10C. LES WILL PEAK THU NIGHT INTO FRI AS AN UPPER TROUGH MOVES
THROUGH AND 850MB TEMPS DROP TO AOB -15C. THIS WILL LEAD TO
INVERSION HEIGHTS AROUND 9-10KFT AND LIFT FAVORABLY LOCATED IN THE
DGZ...PROMOTING MODERATE TO POTENTIALLY HEAVY LES. LOW LEVEL WIND
DIRECTIONS REMAIN IN QUESTION...WITH MODEL SOLUTIONS BETWEEN WSW AND
WNW...WHICH MAKES LES POTENTIAL UNCERTAIN FOR EASTERN LES AREAS OF
ERN ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES. ALL MODELS DO SHOW
WINDS TURNING WNW-NW BY LATE FRI EVENING AND LASTING THROUGH MUCH OF
SAT BEFORE A SFC RIDGE MOVES THROUGH. STILL SEEMS THAT 1-2 SNOWFALL
AMOUNTS OF 8 PLUS INCHES IS LIKELY OVER THE W WIND SNOWBELTS. WILL
LIKELY NEED AN ADVISORY FOR THE KEWEENAW PENINSULA AREA AND WILL
CONTINUE TO HIGHLIGHT THE POTENTIAL FOR PLOW-ABLE SNOW IN THE HWO.
THE SNOW IS EXPECTED TO DIMINISH LATE SAT INTO SAT NIGHT AS DRY AIR
WITH A SURFACE RIDGE MOVES INTO THE AREA.
TEMPS LOOK TO WARM AGAIN EARLY TO MIDDLE OF NEXT WEEK...BUT WILL LET
CONSENSUS GUIDANCE POPULATE THAT PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 653 PM EST TUE DEC 15 2015
EAST TO SOUTHEAST WINDS BETWEEN A LOW PRESSURE SYSTEM MOVING FM THE
PLAINS TO THE UPPER MISSISSIPPI RIVER VALLEY AND HIGH PRESSURE OVER
HUDSON BAY WILL BRING STEADY STATE MVFR CIGS TONIGHT. CIGS LOWER
LATE TONIGHT INTO WED AS THE LOW REACHES MINNESOTA. A LIGHT WINTRY
MIX OF DRIZZLE AND SNOW WILL AFFECT THE TAF SITES LATE TONIGHT INTO
WED MORNING. EVENTUALLY ENOUGH WARM AIR MOVES IN TO CHANGE ANY MIXED
PRECIP TO RAIN BY THE AFTN. OVERALL FOR WED...EXPECT IFR CIGS AND
VSBY. LIFR CIGS BLO 500 FT SHOULD OCCUR AT KSAW LATER WED AFTN DUE
TO PERSISTENT UPSLOPE SE WINDS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE DEC 15 2015
ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP AND SLIDE THROUGH THE UPPER
GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST GALES ARE EXPECTED
OVER THE WEST HALF THIS EVENING INTO WED MORNING AND SOUTHEAST WINDS
WILL REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE
LOW LATE TONIGHT THROUGH WEDNESDAY FOLLOWED BY WESTERLY WINDS
APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON THURSDAY
INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLA
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
550 PM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 547 PM EST MON DEC 14 2015
EXPANDED WINTER WEATHER ADVISORY ACROSS REST OF WESTERN UPR MICHIGAN
THIS EVENING AS REPORTS ARE INDICATING MAINLY SLEET IS OCCURRING IN
DEFORMATION BAND OF WINTRY PRECIP ON WEST SIDE OF SFC LOW VCNTY OF
KISQ AS OF 5 PM. 21Z RAP PEGGING LOCATION OF DEFORMATION BAND WELL
THOUGH SOUNDINGS ARE A BIT TOO COLD ALOFT COMPARED TO REALITY. RAP
SHOWS DEFORMATION BAND WITH QPF AMOUNTS TO 0.15 INCHES THROUGH 00Z
THEN BEGINS TO TAPER. GIVEN MOST OF THE PRECIP IS FALLING AS SLEET
WHICH IS REALLY LEADING TO ROUGH ROAD CONDITIONS PER REPORTS FM
SPOTTERS IN ONTONAGON COUNTY AND SHERIFF IN BARAGA COUNTY...EXPANDED
THE ADVY. A COLD RAIN FARTHER EAST...WITH NWS OFFICE SITTING AT 32-33
AS OF 530 PM. FOR NOW SPS IS OUT FOR IRON/DICKINSON/MARQUETTE AND
THAT PROBABLY WILL HOLD UNLESS HEAVIER DEFORMATION PRECIP SLIDES
FARTHER EAST. WILL KEEP MONITORING THIS. HIGHEST SNOW/SLEET TOTAL WAS
AROUND 2 INCHES FAR WEST...BUT ALREADY SEEING 1-2 INCHES HIGHER
TERRAIN BETWEEN ONTONAGON AND HOUGHTON AND MOST RECENTLY NEAR HERMAN
IN HIGHER TERRAIN OF BARAGA COUNTY. ALL AREAS CURRENTLY SEEING THE
SNOW/SLEET MAY SEE ADDITIONAL 1-2 INCHES BEFORE THE EVENING IS OUT SO
ROADS WILL CONTINUE TO BE IN ROUGH SHAPE.
CURRENT WINTER WEATHER ADVISORIES GO UNTIL 06Z. MAYBE A BIT
LONG...BUT CAN EVALUATE THAT LATER THIS EVENING. COULD SEE THIS
WHOLE WINTRY MIX CHANGE TO DRIZZLE/FREEZING DRIZZLE LATER TONIGHT.
OVERALL A MESSY NIGHT...ESPECIALLY FOR THE HIGHLANDS OF WESTERN UPR
MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EST MON DEC 14 2015
TRICKY FORECAST WITH PRECIPITATION TYPE LATE THIS AFTERNOON INTO
THIS EVENING. WINTER WEATHER ADVISORY IN EFFECT THROUGH 06Z/15FOR
GOGEBIC AND ONTONAGON COUNTIES.
RADAR IMAGERY CONTINUES TO SHOW A WIDE SWATH OF PRECIPITATION ACROSS
THE U.P. STRETCHING BACK INTO THROUGH PORTIONS OF NORTHERN AND
WESTERN WI. SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER ACROSS THE
UPPER GREAT LAKES. WV IMAGERY SHOWS THE UPPER LEVEL LOW CENTERED
OVER SOUTHERN WI THIS AFTERNOON WITH PLENTY OF MOISTURE TO THE NORTH
AND WEST OF THE LOW. THE DRY SLOT ASSOCIATED WITH THE LOW IS WORKING
IN ACROSS SOUTHERN LOWER MI AND THE OHIO VALLEY. SURFACE
OBSERVATIONS...OBSERVERS AND WEBCAMS HAVE BEEN SHOWING A MIX OF
FREEZING RAIN...SLEET AND SNOW ACROSS FAR WESTERN PORTIONS OF THE
U.P. SPECIFICALLY AROUND GOGEBIC AND ONTONAGON COUNTIES.
LATE THIS AFTERNOON THROUGH TONIGHT...THE FAIRLY STRONG SURFACE LOW
SLIDING THROUGH THE U.P. THIS AFTERNOON WILL CONTINUE TO PRODUCE
WIDESPREAD RAINFALL ACROSS THE NORTH HALF OF THE U.P. THESE AREAS
COULD SEE AN ADDITIONAL 0.5 INCH TO 0.75 INCH OF QPF DURING THE MID
TO LATE AFTERNOON HOURS. THE DEEP LAYER FORCING ASSOCIATED WITH THE
LOW WILL LINGER BETWEEN 18Z/14 AND 00Z/15 BEFORE EXITING TO THE
NORTH AND EAST OF THE AREA DURING THE EVENING AND OVERNIGHT HOURS.
THIS CAN BE SEEN BY ANALYZING THE DEEP LAYER QCONV ALONG WITH 1000-
500MB RH. THE BIG ISSUE...HOWEVER...IS PRECIPITATION TYPE. MODELS
HAVE A WARM NOSE ALOFT BETWEEN 800MB AND 850MB...AND A COLDER LAYER
BELOW WHICH HAS LED TO A MIXED BAG OF PRECIPITATION OVER THE FAR
WESTERN U.P. THIS HAS RESULTED IN MAINLY SLEET...HOWEVER...SOME
FREEZING RAIN HAS BEEN REPORTED ACROSS THE FAR WEST AREA AS SURFACE
TEMPERATURES HOVER AROUND 32F.
TIMING OF TRANSITION ACROSS THE U.P. WILL BE A BIT TRICKY...BUT
LATEST MODEL DATA SUGGESTS THAT RAIN WILL MIX WITH SLEET OVER
CENTRAL PORTIONS OF THE U.P. BY 21Z-22Z AND THEN OVER TO SNOW LATER
IN THE EVENING. OVER THE EAST HALF OF THE UPPER
PENINSULA...TEMPERATURES SHOULD REMAIN WARM ENOUGH TO KEEP THE
PRECIPITATION IN THE FORM OF RAIN UNTIL LATE EVENING...WHEN THE
DEEPER MOISTURE PULLS AWAY FROM THE REGION. THE HEAVIEST SLEET/SNOW
TOTALS WILL LIKELY REMAIN CONFINED TO THE GOGEBIC AND ONTONAGON
AREAS AND UP THROUGH THE KEEWEENAW PENINSULA...WHERE THE DEFORMATION
BAND HAS SET UP UNDER THE COMMA HEAD OF THE LOW PRESSURE SYSTEM THIS
AFTERNOON. THIS DEFORMATION BAND IS ON A PIVOT POINT AS THE SURFACE
LOW TAKES ON A MORE EAST TO EAST-NORTHEASTERLY TRACK...HELPING TO
CONCENTRATE THE SNOW/SLEET TOTALS IN THAT AREA. THE FORCING IN THAT
AREA IS ACTUALLY PROVIDING ENOUGH LIFT THIS AFTERNOON TO MIX SOME
SNOWFALL IN WITH THE SLEET. AS FAR AS TOTALS...BY THE TIME THE
DEEPER MOISTURE LEAVE THIS EVENING...WILL BE AROUND 2 TO 4 INCHES IN
ONTONAGON AND GOGEBIC COUNTIES. FARTHER NORTH IN THE KEWEENAW LOOKS
LIKE AROUND 1 TO 2 INCHES...WHILE CENTRAL AREAS WILL LIKELY SEE AN
INCH OR LESS AS THE DEFORMATION SLIDES THROUGH AT A FASTER PACE IN
THOSE AREAS. ONCE THE DEEPER MOISTURE DEPARTS TONIGHT...EXPECT MOST
OF THE PRECIPITATION TO TRANSITION TO DRIZZLE OR FREEZING
DRIZZLE...BUT SNOW WILL ALSO MIX IN OVER THE HIGHER TERRAIN OF THE
WEST...ESPECIALLY ALONG LAKE SUPERIOR WHERE UPSLOPE COULD PROVIDE
ENOUGH LIFT TO INTRODUCE ICE CRYSTALS INTO THE LAYER.
TUESDAY...A MUCH QUIETER WEATHER DAY CAN BE EXPECTED ACROSS THE U.P.
AS THE SURFACE LOW AND UPPER LEVEL LOW PRESSURE SLIDE INTO SOUTHERN
QUEBEC. HIGH PRESSURE AND UPPER LEVEL RIDGING WILL SLIDE IN BEHIND
THE LOW. THIS WILL ALLOW FOR DRIER CONDITIONS ACROSS UPPER
MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY WITH
CONTINUED LOW LEVEL MOISTURE TRAPPED BELOW THE INVERSION IN PLACE
FROM THE UPPER LEVEL RIDGING SLIDING INTO THE AREA. TEMPERATURESWILL
BE MUCH COOLER...ESPECIALLY OVER THE EAST HALF WITH HIGHS ONLY
REACHING INTO THE LOW TO MID 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 503 PM EST MON DEC 14 2015
MODELS SUGGEST THAT A PROGRESSIVE PATTERN WILL CONTINUE TO PREVAIL
WITH A TRANSITION TOWARD COLDER CONDITIONS TOWARD THE END OF THE
WEEK IN THE WAKE OF A MID LEVEL AND SFC LOW LIFTING FROM THE UPPER
MS VALLEY INTO NRN ONTARIO. AS A TROUGH MOVES INTO THE WEST
COAST...A RIDGE WILL BUILD INTO THE CNTRL CONUS BY SUN WITH
MODERATING TEMPS OVER THE WRN LAKES. ANOTHER BATCH OF PCPN MAY BE
POSSIBLE BY MON AS WAA INCREASES AHEAD OF A LOW MOVING IN FROM THE
PLAINS.
TUE NIGHT...ABUNDANT LOW LEVEL MOISTURE BELOW A 900 MB INVERSION
ALONG WITH ERLY FLOW MAY SUPPORT DZ/FZDZ OVER N CNTRL UPPER
MI...ESPECIALLY WHERE UPSLOPE FLOW PREVAILS. OTHERWISE...THE THICK
CLOUD COVER WILL KEEP TEMPS FROM FALLING BELOW THE UPPER 20S.
WED...THE MODELS WERE IN GOOD AGREEMENT WITH THE LOW TRACK FROM SRN
MN AT 12Z TO THE MN ARROWHEAD BY 00Z/THU. FAVORABLE DYNAMICS WITH
MODERATE TO STRONG 700-300 MB QVECTOR CONV AND AN AREA OF 290K-295K
ISENTROPIC LIFT SUPPORT MENTION OF LIKELY POPS OVER THE CNTRL AND
WEST IN THE MORNING INTO THE EAST DURING THE AFTERNOON. PCPN TYPE
WILL AGAIN BE A CONCERN GIVEN DIFFERENCES AND THE TEMP PROFILE
DETAILS. THE NAM SUGGESTS THE STRONGER LIFT WILL BRING ENOUGH LAYER
COOLING TO CHANCE THE PCPN TO MAINLY SNOW DURING THE PERIOD OF
HIGHER QPF...WHILE THE GFS BRINGS GREATER WARMING BY 18Z. FOR
NOW...THE FORECAST EMPHASIZES MAINLY SNOW OVER THE CENTRAL AND WEST
WITH A MIX AND CHANGE TO RAIN ONCE THE STRONGER DYNAMICS MOVE OFF TO
THE EAST. WITH A GREATER WARM AIR INFLUX INTO THE EAST...RAIN SHOULD
PREDOMINATE. ANY SNOWFALL AMOUNTS WOULD BE MINIMAL...MAINLY LESS
THAN AN INCH.
WED NIGHT...WRLY SFC-850 MB CAA ALONG WITH SOME WRAP-AROUND MOISTURE
WILL BRING A CHANGEOVER TO SHSN FROM WEST TO EAST. ANY LES OR LAKE
ENHANCED SNOW WILL BE LIGHT WITH 850 MB TO AROUND -9C LATE WITH A SW
TO WSW LOW LEVEL FLOW PREVAILING.
THU-SAT...COLDER AIR ARRIVES ALONG WITH A SECONDARY MID LEVEL TROUGH
AND LOW. WITH 850 MB TEMPS FALLING TO AROUND -15C AND DEEP MOISTURE
ACROSS THE AREA...LES WILL INCREASE FOR LOCATIONS FAVORED BY W TO
WNW FLOW. ACCUMULATING SNOW OVER THE KEWEENAW WILL BE LIKELY AND BY
FRIDAY NEAR LAKE SUPERIOR EAST OF MUNISING AS THE WINDS VEER
SLIGHTLY. THE LES SHOULD DIMINISH SAT INTO SAT NIGHT AS THE 850 MB
THERMAL TROUGH SLIDES OFF TO THE EAST.
SUN-MON...THERE IS MUCH GREATER UNCERTAINTY WITH THE DETAILS ON THE
STRENGTH/TIMING OF ANY SHORTWAVES LIFTING TOWARD THE UPPER MS VALLEY
AND WRN LAKES. THE OVERALL PATTERN WILL FAVOR A MODERATING TREND
WITH POTENTIAL FOR PCPN AGAIN BY MON. THE PROXIMITY OF THE WARM AIR
AND POTENTIAL FOR A LOW TRACK TO THE WEST OF UPPER MI WILL AGAIN
BRING THE POTENTIAL FOR MIXED PCPN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1232 PM EST MON DEC 14 2015
A STRONG LOW PRESSURE SYSTEM MOVING SOUTH OF THE AREA TODAY WILL
CONTINUE TO BRING LOW CIGS/VIS...WITH SOME IMPROVEMENT STARTING
TUESDAY MORNING. MOST UNCERTAINTY IN THE FIRST 12 HOURS IS WITH
PRECIP TYPE AT KIWD AND KCMX WHERE MODELS ARE NOT HANDLING THERMAL
PROFILES WELL AND A MUCH EARLIER THAN EXPECTED TRANSITION TO
SNOW/MIXED PRECIP HAS OCCURRED. LATER TONIGHT AND TOMORROW THE MOST
UNCERTAINTY IS WITH CIG/VIS MAGNITUDE AND HOW FAST ANY IMPROVEMENT
MAY OCCUR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EST MON DEC 14 2015
AS LOW PRESSURE SLIDES ACROSS THE EASTERN UP THIS AFTERNOON INTO
TONIGHT...NORTHEAST GALES WILL TRANSITION TO NORTH GALES ACROSS LAKE
SUPERIOR AS COLDER AIR FILTERS ACROSS THE LAKE. THERE IS A POTENTIAL
FOR A FEW STORM FORCE GUSTS LATE THIS AFTERNOON INTO THE EARLY
EVENING HOURS...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW.
WINDS WILL SUBSIDE TEMPORARILY ON TUESDAY MORNING BEFORE ANOTHER LOW
PRESSURE SYSTEM DEVELOPS AND SLIDES THROUGH THE UPPER GREAT LAKES
WEDNESDAY INTO THURSDAY. NORTHEAST WINDS WILL INCREASE TO GALES OVER
THE WEST HALF LATE TUE INTO WED MORNING AND SOUTHEAST WINDS SHOULD
REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE LOW
ON WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THECOLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY
FOR MIZ001>004-009-084.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KEC
LONG TERM...JLB
AVIATION...TITUS
MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1234 PM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1232 PM EST MON DEC 14 2015
A STRONG LOW PRESSURE SYSTEM MOVING SOUTH OF THE AREA TODAY WILL
CONTINUE TO BRING LOW CIGS/VIS...WITH SOME IMPROVEMENT STARTING
TUESDAY MORNING. MOST UNCERTAINTY IN THE FIRST 12 HOURS IS WITH
PRECIP TYPE AT KIWD AND KCMX WHERE MODELS ARE NOT HANDLING THERMAL
PROFILES WELL AND A MUCH EARLIER THAN EXPECTED TRANSITION TO
SNOW/MIXED PRECIP HAS OCCURRED. LATER TONIGHT AND TOMORROW THE MOST
UNCERTAINTY IS WITH CIG/VIS MAGNITUDE AND HOW FAST ANY IMPROVEMENT
MAY OCCUR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY
FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...MRD
AVIATION...TITUS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 625 AM EST MON DEC 14 2015
IFR/LIFR CIGS AND VSBYS CONTINUE THROUGH THE FORECAST. NORTHEAST WINDS
WILL BE GUSTY AT ALL THREE TAF SITES AS THE PRESSURE GRADIENT
TIGHTENS UP WITH THE APPROACH OF THE SFC LOW OUT OF THE CENTRAL
MISSISSIPPI VALLEY. THE STRONGEST GUSTS ARE EXPECTED TODAY INTO THE
EVENING HOURS WITH OCCASIONAL GUSTS UP TO AROUND 25 KNOTS
POSSIBLE. THE NEXT CONCERN IS THE PHASE CHANGE FROM RAIN TO SNOW AS
COLDER AIR GET PULLED INTO THE AREA WITH THE SYSTEM EXITING TO THE
EAST. EXPECT RAIN TO CHANGE TO SNOW AT KIWD AROUND 21Z...AT KCMX AFT
00Z AND KSAW AROUND 06Z. SOME DRIZZLE IS ALSO POSSIBLE TONIGHT WITH
FREEZING DRIZZLE POSSIBLE OVER THE WESTERN TAF SITES AS MID-LEVELS
DRY OUT BUT LOW-LEVEL MOISTURE REMAINS. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...VOSS
LONG TERM...- NONE -
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EST MON DEC 14 2015
IFR/LIFR CIGS AND VSBYS CONTINUE THROUGH THE FORECAST. EXPECT WINDS
TO BECOME GUSTY AT ALL THREE TAF SITES AS THE PRESSURE GRADIENT
TIGHTENS UP WITH THE APPROACH OF THE SFC LOW OUT OF THE CENTRAL
MISSISSIPPI VALLEY. THE STRONGEST GUSTS ARE EXPECTED DURING THE
AFTERNOON AND EARLY EVENING HOURS WITH OCCASIONAL GUSTS UP TO AROUND
30 KNOTS POSSIBLE..ESPECIALLY AT KCMX AND KSAW. THE NEXT CONCERN IS
THE PHASE CHANCE FROM RAIN TO SNOW. LATEST NAM MODEL RUN ATTEMPTING
TO MIX PRECIPITATION EARLIER IN THE DAY...BUT WITH THE ABUNDANCE OF
WARM AIR STILL ADVECTING INTO THE REGION THROUGH MUCH OF THE DAY
HAVE PUSHED BACK THE CHANGEOVER TO ALL SNOW CLOSER TO 0Z AT KCMX AND
KIWD...ALTHOUGH THERE WILL BE A MIX OF RAIN AND SNOW IN THE
AFTERNOON. KSAW WILL START TO SEE SNOW MIX IN WITH THE RAIN IN THE
LATE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...VOSS
LONG TERM...- NONE -
AVIATION...RJT
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
406 PM CST MON DEC 14 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 406 PM CST MON DEC 14 2015
LOW THAT PASSED ACROSS THE SE TIP OF MN EARLIER TODAY IS NOW OVER
GREEN BAY. AS THE LOW HAS MOVED OFF TO THE EAST...WE HAVE SEEN A
DRASTIC DECREASE IN DEFORMATION FORCING...WITH A SIGNIFICANT AMOUNT
OF CLOUD TOP WARMING NOTED ON IR...WHICH HAS COINCIDED WITH A
RAPID DIMINISHING IN RADAR RETURNS. FORCING WITHIN THIS BAND WAS
ENOUGH TO COOL THE ATMOSPHERIC COLUMN DOWN WHERE THE HEAVIEST
RATES WERE SEEN TO CHANGE PRECIP OVER TO SNOW. HEAVIEST SNOW WAS
SEEN IN THE EAU CLAIRE AREA...WHICH PICKED UP AROUND AN INCH OF
SNOW. THE BIGGER STORY FOR EAU CLAIRE THOUGH IS THAT THE 1.85" OF
LIQUID PICKED UP THROUGH 3 PM TODAY NOT ONLY SET A NEW RECORD FOR
FOR THE DATE...BUT ALSO BROKE RECORDS FOR THE MOST PRECIP RECEIVED
IN A CALENDAR DAY FOR THE MONTH OF DECEMBER AND ANY CALENDAR DAY
DURING THE METEOROLOGICAL WINTER.
THE GOOD NEWS IS THIS PRECIP WILL BE DEPARTING THE ERN MPX CWA
AROUND 00Z AND WE WILL GET A SHORT BREAK FROM THE PRECIP. LOOKING
OUT WEST...YOU CAN SEE OUR NEXT STORM SYSTEM ACROSS UTAH AND THIS
WILL BE IMPACTING OUR AREA BEGINNING LATE TUESDAY
AFTERNOON...THOUGH THE BRUNT OF IT LOOKS TO COME TUESDAY NIGHT
INTO WEDNESDAY. THERE IS STILL A GOOD DEAL OF SPREAD IN THE
MODELS WITH WHEN PRECIP GETS HERE ON TUESDAY. GFS/NAM AND MOST OF
THE CAMS KEEP PRECIP OUT OF THE MPX CWA THROUGH 6 PM TUESDAY. THE
REASON FOR THIS CAN BE SEEN WHEN LOOKING AT 290-300K ISENTROPIC
SURFACES ON THE GFS/NAM...WHICH KEEP THE WAA BAND OF PRECIP SW OF
THE MPX AREA UNTIL AFTER 6 PM TUESDAY. DESPITE ALL OF THIS...THE
ECMWF AND SREF PROBS SHOW PRECIP SPREADING INTO WRN MN BETWEEN 21Z
AND 00Z. FOR POPS...REMOVED POPS BEFORE NOON...AND DELAYED THE
ARRIVAL OF CHANCE/LIKELY POPS UNTIL 3PM AND LATER.
LASTLY...RH TIME-HEIGHT PROFILES FROM THE GFS SUGGEST WE WILL NOT
GET A GLIMPSE OF CLOUD LESS SKIES UNTIL THIS WEEKEND...THIS WILL
ENSURE WE GET YET ANOTHER DAY WITH A VERY MINIMAL DIURNAL
TEMPERATURE RANGE...WITH LOWS IN THE LOW 30S AND HIGHS IN THE
MID/UPPER 30S ON TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM CST MON DEC 14 2015
THE MAIN WEATHER CONCERN IN THE LONGER TERM REMAINS THE SNOW
POTENTIAL DEVELOPING TUESDAY NIGHT INTO WEDNESDAY.
MODELS ARE IN GENERAL AGREEMENT OF LIFTING A DEEPENING AREA OF LOW
PRESSURE FROM COLORADO/WESTERN KANSAS REGION TUESDAY MORNING...TO
CENTRAL MN BY MIDDAY WEDNESDAY AND THEN NORTHEAST OVER LAKE
SUPERIOR BY WEDNESDAY NIGHT. TRACK OF THE SURFACE LOW AND VARIOUS
BOUNDARY LAYER TEMPERATURE/THICKNESS CONCERNS SHOW MOST OF THE
PRECIPITATION WILL REMAIN LIQUID OVER THE SOUTHEAST HALF OF THE
CWA FOR THIS EVENT. BEST ISENTROPIC LIFT ARRIVES TOWARD 12Z WED
INTO CENTRAL AREAS AND LIFTS NORTHEAST DURING THE MORNING. THIS IS
WHEN THE WARMER AIR LIFTS OUT WITH THE SURFACE LOW SO WE COULD
POSSIBLY SEE A BIT OF SLEET AND OR SNOW DURING THE MORNING COMMUTE
AS IT LIFTS OUT. THE HEAVIER SNOWS WILL FALL OVER THE NORTHWEST
CWA...WITH A 6 INCH SNOW TOTAL POSSIBLE OUT TOWARD KAXN-KMOX
REGION IN ABOUT 18 HOURS IN MORE FAVORABLE DEFORMATION AREA. THE
LATEST HOPWRF TIME SHIFTED 4KM INDICATES 4-5 INCHES CLIPPING THE
FAR NORTHWEST CWA...AND THE 12Z CIPS ANALOG HAZARD GUIDANCE WAS
SHOWING MAYBE 6 INCHES UP IN THE FAR NORTHWEST CORNER AS WELL. WE
WILL FORGO WINTER STORM WATCH FOR THE EVENT WITH THE HIGH
LIKELIHOOD OF AN ADVISORY BEING ISSUED FOR A PORTION OF THE
NORTHWEST CWA. NORTHWEST WINDS ARE EXPECTED TO INCREASE WEDNESDAY
MORNING/AFTERNOON BUT THE HEAVIER SNOW WILL LIKELY HAVE ENDED
BEFORE THE STRONGEST WINDS ARRIVE. THE HEAVIER/WET NATURE OF THE
SNOW SHOULD LIMIT SIGNIFICANT BLOWING/DRIFTING SNOW.
CLOUDS AND WIND WILL REMAIN INTO THURSDAY BEFORE DIMINISHING.
EXPECT SOME CLEARING INTO THURSDAY NIGHT OVER THE WEST AS THE
SURFACE RIDGE MOVES EAST. THIS SHOULD PROVIDE SINGLE DIGITS LOWS
OVER MOST OF THE WEST WITH THE FRESH SNOW COVER FORECAST. FLURRIES
OR SNOW SHOWERS WILL BE POSSIBLE OVER THE NORTHERN CWA THURSDAY AS
WELL AS THE UPPER TROUGH MOVES EAST AND STRONGER CAA DEVELOPS.
MODELS SHOW SLOW TEMPERATURE MODERATION INTO THE WEEKEND WITH THE
12Z ECMWF SHOWING ANOTHER POTENTIAL WAVE DEVELOPING NEXT MONDAY.
THE GFS IS NOT AS FAST IN DEVELOPING THE ENERGY TO THE EAST THAT
QUICKLY. LARGE MODEL SPREAD PRECLUDES MENTION OF ANYTHING FOR THIS
PERIOD AT THE MOMENT. WE`LL CONTINUE A DRY FORECAST FOR FRI-MON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON DEC 14 2015
CLOUD TOP TEMPERATURES BEGAN COOLING AT ABOUT 16Z OVER THE AREA
AND REFLECTIVITY IS NOW QUICKLY FOLLOWING THIS WEAKENING TREND WITH
THE BAND OF PRECIP ACROSS ERN MN AND WRN WI. HOWEVER...LIFT WAS
STRONG AND PERSISTENT ENOUGH TO COOL DOWN THE ATMOSPHERE ENOUGH TO
FORCE PRECIP OVER TO A RA/PL/SN MIX. THIS MIX WILL REMAIN UNTIL
PRECIP ENDS AT EACH LOCATION. THIS PRECIP IS DIMINISHING QUITE
QUICKLY THOUGH...SO FOLLOWED THE HRRR IDEA WITH THIS PRECIP BEING
LARGELY DOWN BY 22Z. FOR THE REST OF TONIGHT...STRATUS WILL REMAIN
IN PLACE...THOUGH EXPECT IT TO REMAIN MVFR. HOWEVER...WE WILL SEE
IFR CIGS OVER THE DAKOTAS WORK EAST WITH TIME...EVENTUALLY WORKING
INTO AXN/RWF AND POSSIBLY STC TONIGHT.
KMSP...PRECIP IS QUICKLY WINDING DOWN AND AS THE RATE
DECREASES...WE WILL SE P-TYPE GO BACK FROM SLEET TO RAIN. 21Z IS
LIKELY A LITTLE LONG TO RUN WITH PRECIP BASED ON CURRENT RADAR
TRENDS. FOR TONIGHT...FORECAST SOUNDING SUPPORT THE LAMP WITH
KEEPING CIGS MVFR...SO REMOVED IFR CIG MENTION 21Z TAFS HAD.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR. LIKELY -RA CHANGING TO -SN LATE. WINDS SE BCMG W
10-15 KTS.
THU...MVFR. SLIGHT CHC -SN. WINDS NW 15G25KTS.
FRI...MVFR CIGS. WINDS NW 15G26KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1215 PM CST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST MON DEC 14 2015
THE DEFORMATION AXIS OF PRECIPITATION ASSOCIATED WITH THE CLOSED LOW
CENTER LIFTING FROM THE MID MO/MS RIVER VALLEYS TO THE GREAT LAKES
HAS SOLIDIFIED OVER THE SOUTHEASTERN THIRD OF THE FORECAST AREA
EARLY THIS MORNING. QUITE AN ATYPICAL SCENARIO FOR MID DECEMBER...AS
THUS FAR THE PRECIP TYPE HAS BEEN ALL RAIN. THIS PRECIPITATION
SHIELD WILL CONTINUE TO GRADUALLY BACK WESTWARD THIS
MORNING...ULTIMATELY REACHING A REDWOOD FALLS TO MORA LINE. DO
EXPECT TO SEE SOME LIGHT SNOW MIX IN PRIOR TO THE PRECIPITATION
ENDING...WITH 14.06Z NAM AND SEVERAL HI-RES SOLUTIONS INDICATING 0-
6KM LAYER MAX WET BULB TEMPS TO DECREASE TO AROUND OR SLIGHTLY BELOW
ZERO FOR A SHORT TIME EARLY THIS AFTERNOON ALONG THE INTERSTATE 35
CORRIDOR NORTHEAST INTO WEST CENTRAL WI IN CONJUNCTION WITH THE
ARRIVAL OF THE STRONGER LIFT. NOT EXACTLY A FAVORABLE TIME FOR
LIQUID PRECIP TO TRANSITION TO SNOW AND ACCUMULATE...SO LIKELIHOOD
IS LOW ACCUMULATIONS WILL BE HIGHER THAN A COUPLE TENTHS OF AN INCH.
THE OTHER NOTABLE FACTOR TODAY IS THAT WINDS WILL CONTINUE TO PICK
UP AS THE RELATED SURFACE TROUGH INCHES INTO SOUTHEAST MN/CENTRAL
WI. SPEEDS WILL BE APPROACHING WIND ADVISORY CRITERIA
/30 MPH SUSTAINED/ WITH GUSTS TO AROUND OR JUST ABOVE 40 KTS. WILL
NOT ISSUE AN ADVISORY AT THIS POINT GIVEN ANTICIPATED SPEEDS ARE
BORDERLINE...AND THE ANTICIPATED DURATION OF THE HIGHEST WINDS IS
ONLY A FEW HOURS.
TEMPERATURES WILL REMAIN PRETTY STABLE OVER THE NEXT 24 HOURS GIVEN
THE EXTENSIVE CLOUD COVER. HIGHS WILL RANGE FROM THE LOWER 30S TO
LOWER 40S...AND LOWS TONIGHT IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CST MON DEC 14 2015
MAIN FORECAST CONCERN DEALS WITH SNOWFALL POTENTIAL LATE TUESDAY
AFTERNOON...THRU WEDNESDAY MORNING BEFORE TAPERING OFF WEDNESDAY
AFTERNO0N AND EVENING.
MODELS CONTINUED TO ADVERTISE A POTENT WEATHER SYSTEM MOVING OUT
OF THE NORTHERN ROCKIES AND INTO THE PLAINS/UPPER MIDWEST TUESDAY
NIGHT/WEDNESDAY. BASED ON THE MOVEMENT/LOCATION OF THE SFC LOW AND
UPPER LEVEL FEATURES...PRECIPITATION WILL BEGIN IN WC/SW MN
TUESDAY EVENING AND SPREAD NE ACROSS SOUTHERN/CENTRAL MN.
THICKNESS VALUES/SFC WET BULB TEMPERATURES AND THE DEPTH OF THE
WARM LAYER MOVING BACK NORTHWARD ACROSS SOUTHERN/EASTERN MN AND
INTO WC WI TUESDAY NIGHT/WEDNESDAY...THE BULK OF ACCUMULATING
SNOWFALL WILL OCCUR FROM WC TO CENTRAL MN. HOWEVER...INITIALLY A
MIXTURE OF RAIN/SNOW OR ALL SNOW WILL OCCUR OVER SOUTHERN MN WHERE
CRITICAL TEMPERATURES IN THE FIRST 3K LAYER ARE COOL ENOUGH TO
SUPPORT SNOW. BUT AS WARMER AIR WRAPS NORTHWARD INTO THIS
SYSTEM LATE TUESDAY NIGHT/WEDNESDAY MORNING...THE SNOW WILL
CHANGE OVER TO RAIN/SNOW...THEN ALL RAIN BY WEDNESDAY MORNING AS
THE SFC LOW MOVES FROM NE IOWA...NORTHWARD INTO CENTRAL MN. ONCE
THE SFC LOW MOVES NE INTO NORTHERN WI/LAKE SUPERIOR...THE
PRECIPITATION WILL CHANGE BACK OVER TO SNOW. HOWEVER...BUT THE
TIME COLDER AIR ARRIVES...MOST OF THE PRECIPITATION WILL HAVE
ENDED. AGAIN...BASED ON TIMING/SFC TEMPS AND SNOWFALL RATIOS WHICH
WILL BE INITIALLY LOW...A BAND OF 4 TO 6 INCHES WILL FALL NE OF A
LINE FROM MADISON/APPLETON CITY...NE TO LITTLE FALLS. LOCALLY
HIGHER AMTS WILL BE POSSIBLE FURTHER NW INTO NW MN WHERE THE DEPTH
OF THE COLDER AIR IS GREATER. A WINTER STORM WATCH HAS BEEN ISSUED
FOR THIS AREA DUE TO THE POSSIBILITY OF 6-8 INCHES OF SNOW.
FURTHER TO THE SE...THE COMBINATION OF WARMER SFC TEMPS...MOSTLY
RAIN DURING THE BULK OF THE EVENT...AND LIMITED TIME FOR SNOWFALL
...LOCALLY ONE INCH WILL FALL. ANYWHERE FROM SOUTH CENTRAL TO
EAST CENTRAL MN...INCLUDING THE TWIN CITIES...SNOWFALL WILL BE
LESS THAN AN INCH.
ALTHOUGH THIS SYSTEM WILL NOT BRING LOTS OF SNOWFALL TO MPX
CWA...IT WILL BRING AN ABRUPT END TO THE MILD TEMPERATURES WE
HAVE BEEN EXPERIENCING. SOME LEFTOVER SNOW/SNOW SHOWERS WILL BE
POSSIBLE WEDNESDAY NIGHT/THURSDAY AS THIS SYSTEM SLOWLY WEAKENS
AND MOVES OFF INTO CANADA.
THE OVERALL PATTERN WILL AGAIN BUCKET BY THIS WEEKEND...WITH A
RETURN TO MODERATING TEMPERATURES. THERE IS ANOTHER STORM SYSTEM
THAT IS EXPECTED TO IMPACT THE UPPER MIDWEST AROUND THE 22/23TH OF
DECEMBER. LIKE WITH PREVIOUS SYSTEMS IN THE PAST MONTH...MILDER AIR
WORKING BACK NORTHWARD WILL AGAIN LEAD TO PRECIPITATION TYPE
CONCERNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON DEC 14 2015
CLOUD TOP TEMPERATURES BEGAN COOLING AT ABOUT 16Z OVER THE AREA
AND REFLECTIVITY IS NOW QUICKLY FOLLOWING THIS WEAKENING TREND WITH
THE BAND OF PRECIP ACROSS ERN MN AND WRN WI. HOWEVER...LIFT WAS
STRONG AND PERSISTENT ENOUGH TO COOL DOWN THE ATMOSPHERE ENOUGH TO
FORCE PRECIP OVER TO A RA/PL/SN MIX. THIS MIX WILL REMAIN UNTIL
PRECIP ENDS AT EACH LOCATION. THIS PRECIP IS DIMINISHING QUITE
QUICKLY THOUGH...SO FOLLOWED THE HRRR IDEA WITH THIS PRECIP BEING
LARGELY DOWN BY 22Z. FOR THE REST OF TONIGHT...STRATUS WILL REMAIN
IN PLACE...THOUGH EXPECT IT TO REMAIN MVFR. HOWEVER...WE WILL SEE
IFR CIGS OVER THE DAKOTAS WORK EAST WITH TIME...EVENTUALLY WORKING
INTO AXN/RWF AND POSSIBLY STC TONIGHT.
KMSP...PRECIP IS QUICKLY WINDING DOWN AND AS THE RATE
DECREASES...WE WILL SE P-TYPE GO BACK FROM SLEET TO RAIN. 21Z IS
LIKELY A LITTLE LONG TO RUN WITH PRECIP BASED ON CURRENT RADAR
TRENDS. FOR TONIGHT...FORECAST SOUNDING SUPPORT THE LAMP WITH
KEEPING CIGS MVFR...SO REMOVED IFR CIG MENTION 21Z TAFS HAD.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR. LIKELY -RA CHANGING TO -SN LATE. WINDS SE BCMG W
10-15 KTS.
THU...MVFR. SLIGHT CHC -SN. WINDS NW 15G25KTS.
FRI...MVFR CIGS. WINDS NW 15G26KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
156 PM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
least -10C progged into the area by Friday morning. This cool
down should bring the CWA its first real taste of winter
temperatures with highs in the 30s to low 40s by Friday...first
time temps have been near or below their daily averages since
early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quickly during this transition, and the main question is
how fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and
50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 148 PM CST Mon Dec 14 2015
Looking at short range models, mvfr cigs to persist through the
night at taf sites. So kept everyone overcast til mid morning on
Tuesday then begin scattering out. Some concern about fog chances
as there is plenty of low level moisture, light winds and a
decent inversion. If clouds remain over region, fog would be less
likely, but will need to keep an eye out. As for winds, gusty
southwest to west winds to persist til 01z-02z Tuesday, then
diminish and become light and variable towards daybreak. On
Tuesday, surface ridge moves off to the east allowing winds to
become southeasterly and pickup to near 10 kts.
Specifics for KSTL:
Looking at short range models, mvfr cigs to persist through the
night in metro area. So kept overcast til 15z Tuesday then begin
scattering out. Some concern about fog chances as there is plenty
of low level moisture, light winds and a decent inversion. If
clouds remain over region, fog would be less likely, but will
need to keep an eye out. As for winds, gusty southwest to west
winds to persist til 01z Tuesday, then diminish and become light
and variable around 09z Tuesday. On Tuesday, surface ridge moves
off to the east allowing winds to become southeasterly and pickup
to near 10 kts.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
553 AM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
least -10C progged into the area by Friday morning. This cool
down should bring the CWA its first real taste of winter
temperatures with highs in the 30s to low 40s by Friday...first
time temps have been near or below their daily averages since
early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quickly during this transition, and the main question is
how fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and
50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 530 AM CST Mon Dec 14 2015
Scattered showers will continue this morning until an upper level
low pressure center has lifted northeast of the area. Brief
downpours have been observed with some of the showers, temporarily
reducing vsbys below 2 miles. Gusty southwest winds are expected
for most of the day with gusts reaching 20-30 kts. Winds should
decrease after 15/00z. Ceilings were highly variable overnight,
but a general improvement is expected for the first part of the
day until wrap-around clouds with MVFR bases arrive later this
morning and into the afternoon. There is some uncertainty on how
quickly these clouds will clear out tonight. Any areas which
experience partial clearing tonight should see patchy fog
development after due to light winds and moist ground conditions.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 AM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
leaast -10C progged into the area by Friday morning. This cool down
should bring the CWA its first real taste of winter temperatures
with highs in the 30s to low 40s by Friday...first time temps have
been near or below their daily averages since early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quicky during this transition, and the main question is how
fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and 50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 554 PM CST Sun Dec 13 2015
Expect RA to continue thru the night. After the RA shield passes
NE of the terminal, expect an area of SHRA to move thru the region
late tonight and into Mon morning. Expect mainly low MVFR
conditions within the main RA shield, but some pockets of IFR are
possible. With sunset, these pockets may expand, but will need to
monitor trends. Also expect winds to pick up late tonight and thru
Mon morning. Going wind forecast may not be high enuf, but will
wait for more guidance tonight. Expect MVFR cigs to persist thru
Mon, perhaps becoming VFR Mon evening.
Tilly
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 54 41 56 48 / 70 5 5 40
Quincy 50 37 50 43 / 60 5 5 20
Columbia 48 38 57 42 / 50 5 5 20
Jefferson City 50 38 59 43 / 50 5 5 20
Salem 54 42 55 47 / 40 5 5 20
Farmington 52 39 57 48 / 30 5 5 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
337 PM MST MON DEC 14 2015
.SHORT TERM...VALID FOR TUE AND WED...
WSR88D RADAR REFLECTIVITY DEPICTING FAIRLY HEAVY SNOWBANDS
CENTERED DIRECTLY OVER BILLINGS AT 330PM. AROUND 3 INCHES HAS
FALLEN AT THE NWS OFFICE SINCE NOON AND IT CONTINUES TO COME DOWN
STEADILY.
THE HRRR DID A VERY GOOD JOB OF KEEPING THE SNOW CONFINED FROM
BILLINGS WEST UNTIL 1100AM DUE TO THE CONTINUAL PUSH OF DRYER AIR
FROM THE EAST. IT ALSO DID A GREAT JOB IN TIMING THE LOWERING
VISIBILITIES AT ALL THE TAF SITES.
ON THE LARGER SCALE...THE WESTERN US CONTINUES TO BE UNDER THE
INFLUENCE OF A LONG WAVE TROUGH. A MID LEVEL LOW CIRCULATION IS
PROGGED TO MOVE OVER WESTERN KANSAS AND CENTRAL NEBRASKA BY EARLY
WEDNESDAY. THE MOISTURE FETCH IS QUITE IMPRESSIVE FOR THIS TIME OF
YEAR...KEEPING QPF VALUES VERY HIGH OVER THE NORTHERN ROCKIES. THE
INTERESTING THING TO NOTE IS THERE IS A LACK OF STRONG UPPER LEVEL
DYNAMIC FORCING WITH THIS SYSTEM. SO PRODUCING THESE TYPES OF SNOW
AMOUNTS IS QUITE IMPRESSIVE.
WITH RESPECT TO THE ONGOING HIGHLIGHTS...THE TIMING ON THE WINTER
WEATHER WARNINGS ARE IN GOOD SHAPE. WITH THIS FORECAST
PACKAGE...DECIDED TO TREND THE SNOWFALL AMOUNTS FOR AREAS FROM
BILLINGS EAST DOWN EVER SO SLIGHTLY. AREAS WEST OF BILLINGS HAVE
BEEN REPORTING ONGOING SNOW TOTALS ON THE ORDER OF 5 TO 6 INCHES.
ALSO...WENT AHEAD AND UPGRADED THE WINTER STORM WATCH TO AN
ADVISORY FOR BOTH FALLON AND CARTER COUNTIES IN EASTERN MONTANA IN
COORDINATION WITH SURROUNDING WFOS. THE SNOW WILL START LATER
THERE AND LAST UNTIL EARLY WEDNESDAY MORNING. EXPECTING THE SNOW
TO END OVER SOUTH CENTRAL MONTANA TO END TUESDAY MORNING.
ROAD CONDITIONS WILL BE THE MAIN IMPACT AND THREAT THIS EVENING.
A FEW VEHICLE SLIDE OFFS HAVE BEEN REPORTED ON INTERSTATE 90 NEAR
BILLINGS AND HIGHWAY 212 NEAR JOLIET. EARLIER SNOWFALL MAY HAVE
MELTED AND REFROZE UNDER A LAYER OF NEW SNOWFALL. ROADS WILL
REMAIN SLICK AND SOMEWHAT SNOWPACKED THROUGH TOMORROW. SINGER
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
UPPER-LEVEL RIDGE APPROACHING FROM THE WEST AND ASSOCIATED
SUBSIDENCE BRING DRY WX TO MUCH OF THE REGION THU AND FRI. WESTERN
ZONES GET UNDER MORE OF A CYCLONIC FLOW LATE FRI AND
SAT...ALLOWING FOR CHANCE OF RAIN/SNOW SHOWERS THERE. SHORTWAVE
TROUGH THEN CROSSES THE REGION ALLOWING FOR LOW-CHANCE POPS LATE
SAT NIGHT AND SUN. THEN FOR MON...GFS BRINGS ANOTHER SHORTWAVE
ACROSS THE REGION WITH ADDITIONAL PRECIP BUT EURO KEEPS REGION
UNDER MORE OF A WEAK SHORTWAVE RIDGING SCENARIO WITH PRECIP
CONFINED TO SW MOUNTAINS. FOR NOW WILL LEAVE OUT PRECIP FOR MOST
OF CWA ON MON.
EXPECT THE COLDEST TEMPERATURES OF THE WEEK ON THURSDAY WITH
READINGS 10-20 DEGREES BELOW NORMAL. THEN AS THE FLOW BECOMES
WESTERLY/SOUTHWESTERLY ON FRIDAY TEMPERATURES MODERATE AND WINDS
WILL INCREASE ESPECIALLY FOR THE GAP FLOW AREAS. COULD BE SOME
AREAS OF BLOWING SNOW BUT IT SEEMS LIKE A SHORT WINDOW GIVEN HOW
QUICKLY TEMPERATURES WANT TO CLIMB ABOVE FREEZING. SATURDAY WILL
BE EVEN WARMER WITH NEAR FREEZING LOWS CONTRIBUTING STRONGLY TO
SNOW MELT. A SLOW COOLING TREND EXPECTED FOR SUNDAY AND MONDAY.
RMS/SINGER
&&
.AVIATION...
MODERATE TO HEAVY SNOW IS ONGOING ACROSS THE FORECAST AREA AND
MOST TERMINALS ARE IN LIFR AND IFR CIGS AND VIS. TWO EXCEPTIONS
ARE KSHR...WITH MVFR...AND KMLS WITH VFR CONDITIONS. MODERATE IFR
SNOW BANDS WILL HOLD OFF UNTIL LATER THIS EVENING AT THESE
TERMINALS WITH KSHR LIKELY SEEING HEAVIER SNOW AFTER 00Z AND KMLS
SEEING THESE CONDITIONS AFTER 03Z. FOR KBIL AND KLVM IFR AND LIFR
CONDITIONS WILL PERSIST THROUGH AT LEAST 06Z TONIGHT BEFORE THE
HEAVIEST SNOW BANDS PUSH EAST AND SOUTHEAST OF THESE TERMINALS.
DOBBS
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 021/026 014/026 005/016 006/038 030/043 030/040 024/040
+6/S 23/J 21/B 11/E 11/B 12/J 11/B
LVM 014/026 012/023 001/017 017/043 035/042 034/035 024/038
+4/S 33/J 31/B 12/J 11/N 32/J 13/J
HDN 020/030 010/028 000/022 905/038 017/044 026/045 014/044
+7/S 34/J 21/B 11/B 11/B 12/J 11/B
MLS 022/029 011/026 003/017 902/032 016/039 020/042 015/039
97/S 42/J 21/B 11/B 11/B 12/J 11/B
4BQ 022/029 013/025 009/018 004/036 021/043 025/044 017/042
99/S 62/J 21/B 11/B 11/B 12/J 11/B
BHK 019/028 013/023 006/017 903/028 015/040 018/040 014/037
77/S 53/J 21/B 11/B 11/B 12/J 01/B
SHR 018/027 013/027 006/022 006/041 022/047 023/041 016/045
++/S 62/J 22/J 11/B 11/B 12/J 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST TUESDAY FOR
ZONES 28-29-34-35-39>42-56-63>68.
WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 30>32-36-38-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO
5 AM MST WEDNESDAY FOR ZONES 33-37.
WY...WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
956 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 938 PM CST TUE DEC 15 2015
OTHER THAN CONVECTION THAT FIRED IN EASTERN NEBRASKA AND SOUTHWEST
IOWA EARLIER THIS EVENING...PRECIPITATION HAS BEEN SLOW TO GET
GOING IN ADVISORY AREA OF NORTHEAST NEBRASKA. HOWEVER THAT IS
CHANGING AT LATE EVENING AS CORE OF LOW PRESSURE SYSTEM SPINS FROM
SOUTH CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. STARTING TO SEE
CELLULAR RADAR RETURNS AHEAD OF THE LOW NORTHWEST OF GRAND ISLAND.
SURFACE PRESSURE FALLS...AND RAP FORECASTS...SUGGEST LOW WILL
TRACK NORTHEAST ALONG AN ALBION TO WAYNE LINE BETWEEN 06Z AND 10Z.
STRONG ISENTROPIC UPGLIDE JUST AHEAD OF LOW COMBINED WITH
INSTABILITY UNDER COLD CORE POINTS TO A NARROW BUT POTENT BAND OF
PRECIPITATION JUST TO THE NORTHWEST OF LOW TRACK. WHILE SURFACE
TEMPERATURES REMAIN AT OR ABOVE FREEZING NOW...AND WILL LIKELY
REMAIN NEAR FREEZING THROUGH THE NIGHT...DYNAMIC COOLING IN COLUMN
SHOULD LEAD TO MODERATE BURSTS OF SNOW FROM TIME TO TIME...AND
WILL OVERCOME MELTING TENDENCY AT THE SURFACE. SOME SNOW RATES TO
OUR WEST HAVE BEEN AT OR ABOVE AN INCH PER HOUR...AND COULD SEE
THESE RATES HERE AS WELL. HOWEVER AS SYSTEM BEGINS ACCELERATING TO
THE NORTHEAST...WOULD NOT EXPECT THAT TO OCCUR FOR LONG. THUS OUR
CURRENT TOTALS IN THE 2 TO 4 INCH RANGE STILL SEEM TO BE ON TRACK.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
FORECAST CONCERNS THROUGH WEDNESDAY WILL BE HOW FAR NORTH THE
DRYSLOT MAKES IT...PRECIPITATION TYPE ACROSS THE FORECAST
AREA...ALONG WITH EXTENT OF FREEZING PRECIPITATION...SNOW
ACCUMULATIONS AND GUSTY WINDS RELATED TO THE STORM SYSTEM MOVING
THROUGH THE HIGH PLAINS.
SURFACE LOW PRESSURE WAS LOCATED OVER EASTERN COLORADO THIS MORNING
WITH EASTERLY FLOW...FOG...AND DRIZZLE ACROSS THE FORECAST AREA.
SURFACE TEMPERATURES WERE MOSTLY AT OR ABOVE FREEZING. ON THE EDGE
OF THE PRECIPITATION SHIELD NEAR NELIGH AND ROYAL...THEY PICKED UP A
HALF AN INCH TO 1 INCH OF WET SNOW BETWEEN 4AM AND 7AM...BUT HAD
SWITCHED OVER THE DRIZZLE/FREEZING DRIZZLE.
THE 12Z OAX SOUNDING WAS SATURATED IN THE LOWEST 2500FT WITH 0.36
PWAT. SURFACE TEMPERATURES WERE ABOVE FREEZING...HOWEVER ABOVE
800FT...TEMPERATURES WERE BELOW FREEZING.
THIS AFTERNOON...THERE IS A 45KT H85 WIND MAX MOVING THROUGH WITH
STRONG WARM ADVECTION THIS SHOULD LIFT ONE AREA OF PRECIPITATION
INTO SOUTH DAKOTA.
BY 00Z THIS EVENING...THE SURFACE LOW PRESSURE SYSTEM IS FORECAST TO
BE NEAR THE KANSAS/NEBRASKA BORDER WITH THE CLOSED H5 LOW OVER
CENTRAL NEBRASKA. THE FORECAST AREA THERMAL PROFILE IS STILL
MILD...HOWEVER THE COLD AIR IS PRESENT IN NORTHEAST NEBRASKA. THE
H85 TEMPERATURES ARE FORECAST TO VARY FROM 0 TO -4C IN NORTHEAST
NEBRASKA...WITH MILDER 0 TO +4 DEG C FARTHER SOUTHEAST. THE
-10 DEG C H7 TEMPERATURES ARE PROGRESSING EASTWARD. MEANWHILE...A
DRY SLOT IF WORKING FROM SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
THROUGH 06Z...LAPSE RATES STEEPEN...FRONTOGENESIS INCREASES OVER
NORTHEAST NEBRASKA...AND THE COLD POCKET RESIDES OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA...ALONG WITH THIS AREA
BEING SATURATED...THESE CONDITIONS CONTINUE THROUGH 12Z FOR
NORTHEAST NEBRASKA AS THE STORM SYSTEM/SURFACE LOW TRACKS ACROSS
EAST CENTRAL/NORTHEAST NEBRASKA INTO SOUTHERN MINNESOTA. SPECIFIC
HUMIDITY VALUES ARE 2 TO 3 G/KG...WITH 3 TO 6 HRS FAVORABLE
LIFT/DEEP SATURATION. THE HRRR EXP SHOWS THAT THE SNOW INCREASES
IN NORTHEAST NEBRASKA AFTER 04Z...AND LASTS INTO WEDNESDAY
MORNING. THE RAP IS SUPPORTIVE IN TYING IN DECENT H85 TRANSPORT OF
MOISTURE FROM THE GULF...ACROSS MISSOURI...INTO IOWA...AND IN A
BAND INTO NORTHEAST NEBRASKA. THIS PATTERN SETS THE STAGE FOR A
FRONTOGENETIC BAND OF SNOW TO DEVELOP IN NORTHEAST NEBRASKA
OVERNIGHT.
THE NORTHEAST PART OF THE FORECAST SHOULD BEGIN TO SEE SNOW
DEVELOP WITH LIGHT RAIN...DRIZZLE...FOG FOR THE REST OF THE AREA.
AS THE SURFACE LOW TRACKS NORTHEAST...SHOULD SEE SNOW CONTINUE
ACROSS PARTS OF NORTHEAST NEBRASKA AND MAY BE HEAVY FOR A COUPLE
OF HOURS WITH THE STRONGER FRONTOGENETIC FORCING. THE SNOW
CONTINUES TO WRAP AROUND THE SYSTEM AFTER 09Z AS THE NORTHWEST
WINDS INCREASE...HOWEVER THE STORM QUICKLY LIFTS NORTHEAST.
WILL NEED TO MONITOR THE DEVELOPMENT OF THIS ENHANCED BAND OF SNOW
AS IT MOVES ACROSS CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. DO
INCLUDE 2 TO 4 INCHES OF SNOW IN NORTHEAST NEBRASKA AND HAVE A
WINTER WEATHER ADVISORY FOR THE SNOW AND BLOWING SNOW WITH THE
GUSTY WINDS. DID DISCUSS WITH WWD ABOUT POTENTIAL 6 INCH AMOUNTS.
TOUGH TO PIN DOWN...HOWEVER 4KM WRF/NAM AND OTHER MODELS SHOW
POTENTIAL FOR AN ENHANCED AREA.
TEMPERATURES WILL BE COLD ALOFT...THUS SOME LIGHT SNOW AND
FLURRIES WHEREVER CLOUDS ARE SUPPORTED AS THE COLD AIR ADVECTION
CONTINUES WEDNESDAY AFTERNOON. NORTHWEST WINDS 15 TO 30 MPH...WITH
THE STRONGEST WINDS IN NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
HIGHS IN THE UPPER 20S TO LOWER 30S WEDNESDAY.
CYCLONIC FLOW WITH SOME ADDITIONAL FLURRIES POSSIBLE INTO THURSDAY
DEPENDING ON CLOUD COVER. HIGHS THURSDAY AND FRIDAY SIMILAR TO
WEDNESDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
THE RIDGE OVER THE ROCKIES SHIFTS INTO THE PLAINS FOR SATURDAY.
SUNDAY...A H5 TROUGH OVER THE ROCKIES BREAKS THE RIDGE DOWN...WITH
A FRONT MOVING ACROSS THE FORECAST AREA INTO SUNDAY NIGHT. EC/GFS
ARE MAINLY DRY...HOWEVER THE GFS IS COLDER WITH A LITTLE LIGHT
SNOW POSSIBLE SUNDAY AFTERNOON/SUNDAY NIGHT IN NORTHEAST NEBRASKA.
THE GFS WASHES OUT THE NEXT FRONT MONDAY NIGHT...HOWEVER A FRONT
IN THE AREA COULD GENERATE SOME SHOWERS IN WESTERN IOWA TUESDAY.
TEMPERATURES SATURDAY THROUGH TUESDAY REMAIN ABOVE NORMAL.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 522 PM CST TUE DEC 15 2015
VARIABLE IFR TO MVFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF
CYCLE. KOFK WILL SEE THE WORST CONDITIONS AS LOW PRESSURE MOVES
THROUGH THE REGION. DRIZZLE WILL CONTINUE THROUGH THE EVENING
HOURS WITH SNOW EXPECTED TO BEGIN OVERNIGHT...BUT SHOULD END BY
MID MORNING. BEHIND THIS...GUSTY NORTHWEST WINDS COULD CREATE
BLOWING SNOW ISSUES. FOR KOMA AND KLNK...PERIODS OF PATCHY DRIZZLE
WILL CONTINUE INTO THE OVERNIGHT HOURS. CLOUDS MAY CLEAR OUT FOR A
FEW HOURS OVERNIGHT...BUT SHOULD MOVE BACK IN WITHIN A FEW HOURS
AS THE LOW PASSES NEARBY. GUSTY NORTHWEST WINDS EXPECTED FOR
WEDNESDAY ON THE BACKSIDE OF THE LOW BUT CEILINGS/VISIBILITIES
SHOULD BEGIN TO IMPROVE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR NEZ011-016.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR NEZ012-017.
IA...NONE.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
527 PM CST TUE DEC 15 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
FORECAST CONCERNS THROUGH WEDNESDAY WILL BE HOW FAR NORTH THE
DRYSLOT MAKES IT...PRECIPITATION TYPE ACROSS THE FORECAST
AREA...ALONG WITH EXTENT OF FREEZING PRECIPITATION...SNOW
ACCUMULATIONS AND GUSTY WINDS RELATED TO THE STORM SYSTEM MOVING
THROUGH THE HIGH PLAINS.
SURFACE LOW PRESSURE WAS LOCATED OVER EASTERN COLORADO THIS MORNING
WITH EASTERLY FLOW...FOG...AND DRIZZLE ACROSS THE FORECAST AREA.
SURFACE TEMPERATURES WERE MOSTLY AT OR ABOVE FREEZING. ON THE EDGE
OF THE PRECIPITATION SHIELD NEAR NELIGH AND ROYAL...THEY PICKED UP A
HALF AN INCH TO 1 INCH OF WET SNOW BETWEEN 4AM AND 7AM...BUT HAD
SWITCHED OVER THE DRIZZLE/FREEZING DRIZZLE.
THE 12Z OAX SOUNDING WAS SATURATED IN THE LOWEST 2500FT WITH 0.36
PWAT. SURFACE TEMPERATURES WERE ABOVE FREEZING...HOWEVER ABOVE
800FT...TEMPERATURES WERE BELOW FREEZING.
THIS AFTERNOON...THERE IS A 45KT H85 WIND MAX MOVING THROUGH WITH
STRONG WARM ADVECTION THIS SHOULD LIFT ONE AREA OF PRECIPITATION
INTO SOUTH DAKOTA.
BY 00Z THIS EVENING...THE SURFACE LOW PRESSURE SYSTEM IS FORECAST TO
BE NEAR THE KANSAS/NEBRASKA BORDER WITH THE CLOSED H5 LOW OVER
CENTRAL NEBRASKA. THE FORECAST AREA THERMAL PROFILE IS STILL
MILD...HOWEVER THE COLD AIR IS PRESENT IN NORTHEAST NEBRASKA. THE
H85 TEMPERATURES ARE FORECAST TO VARY FROM 0 TO -4C IN NORTHEAST
NEBRASKA...WITH MILDER 0 TO +4 DEG C FARTHER SOUTHEAST. THE
-10 DEG C H7 TEMPERATURES ARE PROGRESSING EASTWARD. MEANWHILE...A
DRY SLOT IF WORKING FROM SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
THROUGH 06Z...LAPSE RATES STEEPEN...FRONTOGENESIS INCREASES OVER
NORTHEAST NEBRASKA...AND THE COLD POCKET RESIDES OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA...ALONG WITH THIS AREA
BEING SATURATED...THESE CONDITIONS CONTINUE THROUGH 12Z FOR
NORTHEAST NEBRASKA AS THE STORM SYSTEM/SURFACE LOW TRACKS ACROSS
EAST CENTRAL/NORTHEAST NEBRASKA INTO SOUTHERN MINNESOTA. SPECIFIC
HUMIDITY VALUES ARE 2 TO 3 G/KG...WITH 3 TO 6 HRS FAVORABLE
LIFT/DEEP SATURATION. THE HRRR EXP SHOWS THAT THE SNOW INCREASES
IN NORTHEAST NEBRASKA AFTER 04Z...AND LASTS INTO WEDNESDAY
MORNING. THE RAP IS SUPPORTIVE IN TYING IN DECENT H85 TRANSPORT OF
MOISTURE FROM THE GULF...ACROSS MISSOURI...INTO IOWA...AND IN A
BAND INTO NORTHEAST NEBRASKA. THIS PATTERN SETS THE STAGE FOR A
FRONTOGENETIC BAND OF SNOW TO DEVELOP IN NORTHEAST NEBRASKA
OVERNIGHT.
THE NORTHEAST PART OF THE FORECAST SHOULD BEGIN TO SEE SNOW
DEVELOP WITH LIGHT RAIN...DRIZZLE...FOG FOR THE REST OF THE AREA.
AS THE SURFACE LOW TRACKS NORTHEAST...SHOULD SEE SNOW CONTINUE
ACROSS PARTS OF NORTHEAST NEBRASKA AND MAY BE HEAVY FOR A COUPLE
OF HOURS WITH THE STRONGER FRONTOGENETIC FORCING. THE SNOW
CONTINUES TO WRAP AROUND THE SYSTEM AFTER 09Z AS THE NORTHWEST
WINDS INCREASE...HOWEVER THE STORM QUICKLY LIFTS NORTHEAST.
WILL NEED TO MONITOR THE DEVELOPMENT OF THIS ENHANCED BAND OF SNOW
AS IT MOVES ACROSS CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. DO
INCLUDE 2 TO 4 INCHES OF SNOW IN NORTHEAST NEBRASKA AND HAVE A
WINTER WEATHER ADVISORY FOR THE SNOW AND BLOWING SNOW WITH THE
GUSTY WINDS. DID DISCUSS WITH WWD ABOUT POTENTIAL 6 INCH AMOUNTS.
TOUGH TO PIN DOWN...HOWEVER 4KM WRF/NAM AND OTHER MODELS SHOW
POTENTIAL FOR AN ENHANCED AREA.
TEMPERATURES WILL BE COLD ALOFT...THUS SOME LIGHT SNOW AND
FLURRIES WHEREVER CLOUDS ARE SUPPORTED AS THE COLD AIR ADVECTION
CONTINUES WEDNESDAY AFTERNOON. NORTHWEST WINDS 15 TO 30 MPH...WITH
THE STRONGEST WINDS IN NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
HIGHS IN THE UPPER 20S TO LOWER 30S WEDNESDAY.
CYCLONIC FLOW WITH SOME ADDITIONAL FLURRIES POSSIBLE INTO THURSDAY
DEPENDING ON CLOUD COVER. HIGHS THURSDAY AND FRIDAY SIMILAR TO
WEDNESDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
THE RIDGE OVER THE ROCKIES SHIFTS INTO THE PLAINS FOR SATURDAY.
SUNDAY...A H5 TROUGH OVER THE ROCKIES BREAKS THE RIDGE DOWN...WITH
A FRONT MOVING ACROSS THE FORECAST AREA INTO SUNDAY NIGHT. EC/GFS
ARE MAINLY DRY...HOWEVER THE GFS IS COLDER WITH A LITTLE LIGHT
SNOW POSSIBLE SUNDAY AFTERNOON/SUNDAY NIGHT IN NORTHEAST NEBRASKA.
THE GFS WASHES OUT THE NEXT FRONT MONDAY NIGHT...HOWEVER A FRONT
IN THE AREA COULD GENERATE SOME SHOWERS IN WESTERN IOWA TUESDAY.
TEMPERATURES SATURDAY THROUGH TUESDAY REMAIN ABOVE NORMAL.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 522 PM CST TUE DEC 15 2015
VARIABLE IFR TO MVFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF
CYCLE. KOFK WILL SEE THE WORST CONDITIONS AS LOW PRESSURE MOVES
THROUGH THE REGION. DRIZZLE WILL CONTINUE THROUGH THE EVENING
HOURS WITH SNOW EXPECTED TO BEGIN OVERNIGHT...BUT SHOULD END BY
MID MORNING. BEHIND THIS...GUSTY NORTHWEST WINDS COULD CREATE
BLOWING SNOW ISSUES. FOR KOMA AND KLNK...PERIODS OF PATCHY DRIZZLE
WILL CONTINUE INTO THE OVERNIGHT HOURS. CLOUDS MAY CLEAR OUT FOR A
FEW HOURS OVERNIGHT...BUT SHOULD MOVE BACK IN WITHIN A FEW HOURS
AS THE LOW PASSES NEARBY. GUSTY NORTHWEST WINDS EXPECTED FOR
WEDNESDAY ON THE BACKSIDE OF THE LOW BUT CEILINGS/VISIBILITIES
SHOULD BEGIN TO IMPROVE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR NEZ011-016.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO NOON CST
WEDNESDAY FOR NEZ012-017.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KERN
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1045 PM MST SUN DEC 13 2015
.AVIATION...
06Z TAF CYCLE
BAND OF MID TO HIGH CLOUDS WILL CROSS NM FROM WEST TO EAST IN
ADVANCE OF INCOMING STORM SYSTEM CURRENTLY DIGGING INTO THE GREAT
BASIN. LOCALLY GUSTY WESTERLY WINDS POSSIBLE THRU 15Z ALONG THE
CENTRAL MT CHAIN DUE TO SFC LEE TROF. STILL NOT ANTICIPATING
WIDESPREAD LOW CLOUDS OR FOG BEFORE 13Z ALTHOUGH SOME LOCALIZED
MVFR TO IFR CIGS/VSBYS IN BR COULD DEVELOP ALONG THE CENTRAL MT
CHAIN AND NW NM. DETERIORATING CONDITIONS EXPECTED AFT 17Z WEST OF
THE CONTDVD AS THE STORM SYSTEM BEGINS TO AFFECT NM.
&&
.PREV DISCUSSION...636 PM MST SUN DEC 13 2015...
.UPDATE...
SNOW AND THE STRONGER WINDS HAVE ABATED IN UNION COUNTY THIS
EVENING...SO THE WINTER STORM WARNING WILL BE CANCELLED FOR THIS
LAST REMAINING ZONE. THE WATCH WILL CONTINUE FOR THE NORTHERN
MOUNTAINS FOR LATE MONDAY INTO TUESDAY WHEN THE NEXT STORM SYSTEM
WILL QUICKLY ARRIVE.
FOR TONIGHT...THERE IS STILL SOME CONCERN THAT PATCHES OF
FREEZING FOG COULD DEVELOP. THE HRRR AND RAP MODELS INDICATE THE
MIDDLE RIO GRANDE VALLEY AND SOME OF THE SHELTERED AND RELATIVELY
LOWER ELEVATIONS IN THE NORTH CENTRAL TO NORTHWEST PARTS OF NM
MIGHT BE FAVORED FOR NEAR-SURFACE SATURATION. DEWPOINTS DID NOT
SURGE UP AS HIGH AS MIGHT BE EXPECTED IN THIS REGION CONSIDERING
THIS AFTERNOON`S INSOLATION AND MELTING SNOW...SO CONFIDENCE IN
FOG DEVELOPMENT IS NOT ALL THAT HIGH. THUS...ONLY A MINIMAL
EXPANSION OF FOG WAS DRAWN IN FOR THESE AREAS. THESE ALTERATIONS
WILL NOT BE REFLECTED IN THE ZONE FORECAST PACKAGE...BUT ONLY IN
THE POINT AND CLICK WEB BASED FORECAST. THUS NO NEW UPDATED ZONE
FORECAST PACKAGE WILL BE SENT AT THIS TIME.
52
&&
.PREV DISCUSSION...311 PM MST SUN DEC 13 2015...
.SYNOPSIS...
ANOTHER STORM WILL MOVE OVER NEW MEXICO MONDAY THROUGH TUESDAY. VERY
COLD AIR AND BREEZY CONDITIONS WILL FORCE WIND CHILL VALUES INTO THE
SINGLE DIGITS AND TEENS THROUGH WEDNESDAY. OVERNIGHT LOWS WILL BE
THE COLDEST OF THE SEASON WITH READINGS NEAR ZERO IN NORTHERN AND
WESTERN VALLEYS BY TUESDAY AND WEDNESDAY NIGHT. A HEAVY DOSE OF
DRY FLUFFY SNOWFALL IS POSSIBLE ON WEST FACING SLOPES OF THE
SANGRE DE CRISTO MOUNTAINS AND THE SAN JUANS MONDAY NIGHT AND
TUESDAY. HIGH TEMPERATURES WILL REMAIN VERY COLD THROUGH THURSDAY
BEFORE A SLOW WARMING TREND BEGINS LATE IN THE WEEK.
&&
.DISCUSSION...
BLIZZARD CONDITIONS ARE SLOWLY WINDING DOWN OVER UNION COUNTY WHERE
SEVERAL ROAD CLOSURES HAVE OCCURRED. VSBYS NEAR ONE QUARTER MILE FOR
MOST OF THE DAY WITH STRONG WINDS HAS LED TO EXTREMELY DANGEROUS
TRAVEL. THE ONE SAVING GRACE IS TEMPS ARE HOVERING NEAR FREEZING...
MAKING THE SNOWFALL AT LEAST A LITTLE STICKIER. NONETHELESS...WILL
STILL HIGHLIGHT BLOWING SNOW THROUGH TONIGHT AND POSSIBLY EXTEND
WARNING THROUGH THE EVENING...OR REPLACE WITH BLOWING SNOW ADVISORY.
THE BIG STORY OVER THE COMING DAYS WILL BE VERY COLD AIR SETTLING
INTO THE STATE BEHIND THE NEXT SYSTEM ARRIVING FROM THE NORTHWEST...
AS WELL AS A POTENTIALLY IMPRESSIVE WEST SLOPE SNOW EVENT FOR THE
SANGRE DE CRISTOS AND SAN JUANS. THE PACIFIC FRONT WILL ARRIVE FROM
WEST TO EAST MONDAY AND ALLOW ANY RAIN TO CHANGE TO SNOW WHILE TEMPS
TUMBLE. WINDS WILL ALSO BE GUSTY ALONG AND BEHIND THE FRONT. STRONG
COLD ADVECTION ON MOIST UNSTABLE WESTERLY FLOW WILL FORCE AN IDEAL
DENDRITIC GROWTH ZONE SMACK DAB OVER THE HIGH TERRAIN MONDAY NIGHT
TO TUESDAY. THE SPC HI RES WRF...THE LOCAL 5KM WRF...AND NAM218 ARE
SQUEEZING OUT GENEROUS QPF FOR SUCH A COLD LAYER...LEADING TO VERY
HIGH SNOW RATIOS AROUND 20:1. WILL HOIST A WATCH FOR THESE AREAS.
MAY ALSO SEE A FEW ADVISORIES IN ADJACENT LOWER TERRAIN AREAS.
OVERNIGHT LOWS BEHIND THIS SYSTEM WILL BE THE COLDEST OF THE SEASON
WITH LOTS OF NEAR ZERO TO LOW TEENS FOR CENTRAL AND WESTERN NM.
WINDS WILL ALSO MAKE IT FEEL BRUTAL. ONE MORE FAST MOVING WAVE IN NW
FLOW IS SHOWN TO MOVE OVER THE STATE THURSDAY BEFORE A SLOW WARMING
TREND DEVELOPS OVER THE WEEKEND.
GUYER
&&
.FIRE WEATHER...
AS THE FIRST IN A ONE TWO PUNCH OF UPPER LEVEL LOW PRESSURE SYSTEMS
EXITS THE AREA TO THE NE...STRONG WINDS WILL GRADUALLY WEAKEN ACROSS
NE NM THIS EVENING. HOWEVER...BREEZY TO WINDY CONDITIONS ARE
EXPECTED THROUGH TONIGHT ACROSS THE HIGH TERRAIN OF NORTHERN AND
CENTRAL NM...AS WELL AS THE REGION FROM CLINES CORNERS TO VAUGHN.
THERE WILL A BRIEF WEAKENING OF WINDS ALOFT THIS EVENING...BUT
SPEEDS WILL STRENGTHEN AGAIN TONIGHT THROUGH MONDAY AS ANOTHER JET
STREAK MOVES OVER THE AREA AROUND THE BASE OF OUR NEXT UPPER LEVEL
TROUGH. WITH ALL THE SNOW ON THE GROUND VERTICAL MIXING WILL BE
LIMITED MONDAY...RELEGATING STRONGER SOUTHWEST WINDS TO THE HIGH
TERRAIN. IT WILL BE LESS WINDY BUT STILL GUSTY AT LOWER
ELEVATIONS...ESPECIALLY FROM CLINES CORNERS TO GRAN QUIVIRA AND
BOSQUE DEL APACHE.
THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM IS FORECAST TO TRACK
EASTWARD ACROSS S CO MONDAY NIGHT AND TUESDAY. MODELS DEPICT A
DECENT TAP OF MOISTURE OFF THE PACIFIC WITH THIS STORM. AND...IT
WILL BE A COLD SYSTEM WHICH WILL SPREAD SNOW ACROSS MUCH OF
WESTERN...NORTHERN AND CENTRAL NM MONDAY AND MONDAY NIGHT.
THEN...DRIER VARIETY SNOW WILL PERSIST THROUGH AT LEAST TUESDAY IN
THE NORTHERN MOUNTAINS WITH SIGNIFICANT ACCUMULATION POSSIBLE THERE.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST MONDAY NIGHT SHIFTING
WINDS OUT OF THE W BY TUESDAY. A DECENT SURFACE PRESSURE GRADIENT
AROUND THE BASE OF A SURFACE LOW EXITING COLORADO...AND THE TAIL END
OF THE AFOREMENTIONED JET STREAK...SHOULD SET UP EASTERN AREAS FOR A
WINDY DAY ON TUESDAY WITH GUSTS IN THE 40 TO PERHAPS 50 MPH RANGE
AROUND AND S OF I-40.
NW FLOW ALOFT WILL TRACK AN ADDITIONAL UPPER LEVEL TROUGH ACROSS NE
NM THURSDAY...WITH LIGHT ADDITIONAL PRECIP POSSIBLE ACROSS THE
NORTHERN MOUNTAINS AND NE.
TEMPERATURE-WISE...AFTER A BRIEF REBOUND OF HIGHS ON
MONDAY...READINGS WILL PLUMMET AROUND 10 TO 19 DEGREES BELOW NORMAL
TUESDAY THROUGH THURSDAY. WIDESPREAD POOR VENTILATION IS EXPECTED
FROM THE RIO GRANDE VALLEY EASTWARD MONDAY...BUT WESTERN AREAS
SHOULD HAVE STRONG VENTILATION AS WINDS ALOFT STRENGTHEN FROM THE
WEST. THE PASSING UPPER LOW AND UPPER TROUGH WILL LEAD TO
VENTILATION IMPROVEMENT AREAWIDE TUESDAY AND THURSDAY...BUT
WIDESPREAD POOR VENTILATION IS EXPECTED IN THE WAKE OF COLD FRONTS
WEDNESDAY AND FRIDAY.
TEMPERATURES SHOULD REBOUND NICELY AS A RIDGE OF HIGH PRESSURE
CROSSES AT THE END OF THE WEEK...BUT TEMPERATURE INVERSIONS SHOULD
KEEP VENTILATION POOR FOR MANY AREAS INTO NEXT WEEKEND.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON
FOR THE FOLLOWING ZONES... NMZ510-512>514.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1032 PM EST TUE DEC 15 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT AND SLIDE
OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL APPROACH FROM THE
WEST THURSDAY AND CROSS THE AREA FRIDAY. HIGH PRESSURE WILL BUILD
IN FROM THE WEST THIS WEEKEND THEN SLIDE OFFSHORE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 930 PM TUESDAY...TEMPS HAVE RAPIDLY DROPPED THIS EVENING
WITH EXCELLENT RADIATIONAL COOLING. LOWERED INIT TEMPS BUT FCST
LOWS LOOK GOOD WITH LOWER 40S INLAND TO LOWER 50S MOST BEACHES.
DEWPTS HAVE HELD UP AND NOW HAVE MINIMAL TEMP/DEWPT SPREAD. ADDED
SOME PATCHY FOG ESPCLY SRN TIER WHERE HRRR SHOWS BEST FOG THREAT.
LATE TONIGHT EXPECT A LIGHT NE BREEZE TO DEVELOP AS HIGH PRES
BUILDS IN FROM THE NW AND THAT SHLD HELP DISSIPATE FOG ESPCLY NRN
HALF OF REGION.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 230 PM WEDNESDAY...NORTH TO SOUTH ORIENTED HIGH PRESSURE
WILL CONTINUE TO INFLUENCE THE WEATHER WHILE MOVING OFFSHORE.
CLEAR SKIES EXPECTED MOST OF THE DAY WITH INCREASING CLOUDS IN
ADVANCE OF THE NEXT FRONT EXPECTED LATE IN THE DAY. HIGHS WILL
CONTINUE ABOVE NORMAL WITH READINGS IN THE MIDDLE TO UPPER 60S
MOST LOCATIONS WITH A FEW OF THE NORMALLY WARMER LOCATIONS LIKELY
REACHING 70 DEGREES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 333 PM TUESDAY...
WEDNESDAY NIGHT...THE SURFACE RIDGE OVER THE MID-ATLANTIC WILL
SHIFT EAST OVER NEW ENGLAND WHILE A WARM FRONT LIFTS NORTH
OVERNIGHT. VEERING FLOW ALOFT AND MOISTENING WILL SPELL FOR
INCREASING SHOWER CHANCES OVERNIGHT WITH THE ISENTROPIC LIFT
INCREASING THROUGH THE NIGHT. FIRST PART OF THE EVENING WILL BE
DRY WITH JUST AN INCREASE IN CLOUDS...THEN INCREASING POP TREND
LATE. LIKELY POPS CONFINED TO FAR SOUTHEASTERN AREAS BY SUNRISE.
LOW TEMPS WILL LIKELY BE REALIZED PRIOR TO MIDNIGHT...BEFORE
STEADILY RISING THEREAFTER AS THE WARM FRONT LIFTS NORTH.
THURSDAY THROUGH FRIDAY...A DEEP BROAD UPPER TROUGH AND COLD
FRONT WILL PUSH INTO THE TN VALLEY ON THUR. OUT AHEAD OF IT...RICH
GULF MOISTURE WILL SURGE IN ON STRENGTHENING SRLY LOW LEVEL FLOW.
PW`S INC THROUGH THE DAY TO 1.75-2.00 INCHES BY THUR AFTERNOON...
ABOVE THE CLIMATOLOGICAL MAX FOR MID DECEMBER. LARGE SCALE LIFT
CONTINUES TO INCREASE WITH WIDESPREAD RAIN SHOWERS ESP FOR THE
SECOND HALF OF THE DAY AND ACROSS THE COASTAL PLAIN COUNTIES.
ECM CONTINUES TO BE SLIGHTLY SLOWER AND HAS SUPPORT FROM THE
CMC/NAM SOLN...WITH THE GFS A SLIGHTLY FASTER OUTLIER. CONTINUED
THE BEST CHANCE FOR RAIN THUR NIGHT THEN A SLOW DECREASING TREND
ON FRIDAY. MOST AREAS WILL DRY AFTER NOON ON FRIDAY WITH JUST A
CHANCE REMAINING ON THE OBX. WILL HAVE TO MONITOR FLOOD POTENTIAL
ESP THUR NIGHT DUE TO ANOMALOUSLY HIGH PWATS...DEEP WARM CLOUD
LAYER...AND RELATIVELY SLOW FRONTAL PASSAGE. CONTINUED MENTION OF
THUNDERSTORMS THURSDAY AS MODEST INSTABILITY WITH SLIGHTLY BACKED
SURFACE WINDS WILL BE PRESENT. TEMPS WILL REMAIN VERY WARM AHEAD
OF FRONT AND DESPITE THE CLOUDS AND RAIN WITH HIGHS THURSDAY IN
THE 70S PER MODEL THICKNESSES 1385-1395 METERS.
FRIDAY NIGHT THROUGH MONDAY...STRONG COLD AIR ADVECTION DEVELOPS
BEHIND THE FRONT FRIDAY NIGHT INTO SATURDAY WITH BELOW NORMAL
TEMPS. SW WINDS WILL VEER NW AND STRENGTHEN FRI NIGHT...WITH STRONGEST
WINDS EXPECTED TO OCCUR SATURDAY COINCIDENT TO THE UPPER TROUGH
AXIS MOVING ACROSS THE REGION. LOWS FRIDAY NIGHT NEAR CLIMO IN THE
30S. HIGHS SATURDAY IN THE UPPER 40S/LOWER 50S. SATURDAY NIGHT
SHOULD BE COLDEST NIGHT OF THE PERIOD WITH UPPER 20S/LOW 30S
(MID/UPR 30S OBX). THE COOL SNAP WILL BE SHORT LIVED DUE TO
PROGRESSIVE TROUGH MOVING QUICKLY EAST WITH BUILDING
HEIGHTS/THICKNESSES SUNDAY AND MONDAY. MAX TEMPS BACK TO AROUND
CLIMO WITH MID/UPPER 50S SUNDAY THEN ABOVE CLIMO AGAIN BY MONDAY
WITH 60S.
TUESDAY...THE BEGINNING OF ANOTHER VERY WARM DECEMBER `HEAT` WAVE
BEGINS NEXT WEEK WITH DEEP TROUGH DIGGING ACROSS THE INTERMOUNTAIN
WEST AND LARGE RIDGE AMPLIFYING ACROSS THE EASTERN HALF OF THE
CONUS. 500 MB HT ANOMOLIES PER CMC/ECM/GFS ENSEMBLE MEAN ALL
INDICATING WELL ABOVE NORMAL HTS. DEEP MOISTURE FEED FROM THE GULF
WILL BE PRESENT AS WELL AND COULD BE THE BEGINNING OF A WET
PATTERN ACROSS E NC.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 530 PM TUESDAY...PRED VFR CONDITIONS EXPECTED THROUGH THE
TAF PERIOD WITH HIGH PRESSURE IN CONTROL PRODUCING MAINLY CLR
SKIES. LIGHT WINDS TONIGHT WILL ALLOW TEMPS TO APPROACH DEWPTS
BUT THINK ANY FOG WILL BE QUITE PATCHY...MAY ADD TEMPO MVFR VBSY
LATE ESPCLY PGV WHERE SEEM MOST SUSCEPTIBLE TO DITCH FOG.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 333 PM TUESDAY...INCREASING CLOUDS AND SHOWER CHANCES WED
NIGHT WITH LOWERING CIGS TO POSSIBLY SUB VFR BY LATE EVENING.
BETTER CHANCES OF SUB- VFR THURSDAY INTO FIRST PART OF FRIDAY
WITH GOOD COVERAGE OF SHOWERS EXPECTED AHEAD OF A STRONG COLD
FRONT. WINDS WILL BE QUITE GUSTY OUT OF THE SOUTH THUR AFTERNOON.
GRADUALLY IMPROVING CONDITIONS EXPECTED FRIDAY AS DEEP MOISTURE
MOVES OFFSHORE AND DRY AIR SURGES IN ON NW WINDS BY FRI AFTERNOON.
VFR SKC EXPECTED SATURDAY AND SUNDAY AS STRONG HIGH PRESSURE
SHIFTS THROUGH THE CAROLINAS.
&&
.MARINE...
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 930 PM TUESDAY...NO CHANGES WITH LIGHT WINDS CURRENTLY
EXPECTED TO BECOME NNE 10 TO 15 KTS LATE AS HIGH PRES BUILDS IN
FROM NW. SEAS 2 TO 4 FEET OVERNIGHT.
PREV DISC...MODERATE WESTERLY FLOW 15 TO 20 KT CURRENTLY BEING
OBSERVED AT THE BUOYS IN WAKE OF COLD FRONTAL PASSAGE AND BUILDING
HIGH PRESSURE WILL BEGIN TO DIMINISH SLIGHTLY LATE TODAY AND
ESPECIALLY TONIGHT TO 10 TO 15 KT WHILE VEERING TO NORTH AND
NORTHEAST. SEAS OVER THE OUTER CENTRAL WATERS CONTINUE AT 6 FT
THIS AFTERNOON AND MAY HAVE TO EXTEND THE SCA THERE FOR ANOTHER
COUPLE OF HOURS INTO THE EARLY EVENING HOURS OTHERWISE SEAS WILL
BE SUBSIDING TO TO 2 TO 4 FT TONIGHT.
WINDS ARE FORECAST TO CONTINUE TO VEER FROM NORTHERLY TO EASTERLY
10 TO 15 KT AS HIGH PRESSURE MOVES OFF OF THE COAST. SEAS ARE
FORECAST TO REMAIN 2-4 FT.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 333 PM TUESDAY...SEAS 2-3 FEET WEDNESDAY NIGHT...WITH
EASTERLY WINDS 5-10 KT IN THE EVENING VEERING SOUTHEAST AND INC
10-15 KT LATE AS A WARM FRONT LIFTS THROUGH THE WATERS. SOUTHERLY
GRADIENT INCREASES ON THURSDAY WITH WINDS INC TO 15-25
KT...HIGHEST ON THE OUTER SOUTHERN/CENTRAL WATERS. A SCA WILL
LIKELY BE NEEDED...POSSIBLY FOR THE NORTHERN WATERS AND PAMLICO
SOUND AS WELL. A SLIGHT DECREASE IN WINDS/SEAS EXPECTED EARLY
FRIDAY AND MAY SEE CONDITIONS BRIEFLY DROP BELOW SCA CRITERIA.
COLD FRONT WILL PASS THROUGH THE WATERS FRI AFTERNOON WITH WINDS
VEERING NW. STRONG CAA FRI NIGHT INTO FIRST PART OF SAT WITH WINDS
INC TO 20-30 KT. SCA WILL LIKELY BE NEEDED FOR ALL WATERS AS WELL
AS THE SOUNDS. HIGH PRES BUILDS IN SAT NIGHT AND SHIFTS OFFSHORE
SUNDAY WITH WINDS/SEAS DIMINISHING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...RF
SHORT TERM...JME
LONG TERM...TL
AVIATION...RF/TL/LEP
MARINE...RF/JME/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
714 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA FRIDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 7 AM MONDAY...MID AND HIGH CLOUDS CONTINUE TO INCREASE AND
COUPLED WITH 4-6 KNOT SOUTHERLY WINDS...THE PATCHY FOG HAS
DISSIPATED ACROSS THE REGION. LOW-LEVEL MOISTURE WILL CONTINUE TO
STEADILY INCREASE THROUGH THE DAY AHEAD OF COLD FRONT AS
PRECIPITABLE WATER VALUES FROM THE HRRR MODEL SURGES TO NEAR 2
INCHES BY LATE AFTERNOON. RADAR REFLECTIVITY PROGS FROM HRRR/RAP
AND 4KM NAM DO NOT SHOW MUCH IN THE WAY OF PRECIPITATION BEFORE
ABOUT 18Z WITH SHOWERS MOVING IN AFTER THAT AND CONTINUING INTO
THE EVENING. PER FORECAST SOUNDINGS...INSTABILITY IS LIMITED BUT
WITH WARM HIGH TEMPERATURES WELL INTO THE 70S...CONTINUED THE
MENTION OF A SMALL THREAT OF THUNDER TODAY. WOULD EXPECT THE
HEAVIEST OF ANY RAIN THAT FALLS TODAY TO BE NEAR THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 320 AM MONDAY...RAIN WILL LINGER NEAR THE COAST THROUGH
ABOUT MIDNIGHT BEFORE RAPID CLEARING OCCURS BETWEEN 06Z AND 12Z
WITH DOWNSLOPING FLOW AND LOWERING DEWPOINTS. LOWS TONIGHT WILL BE
IN THE 50S AREA-WIDE...EXCEPT LOWER 60S ALONG THE OUTER BANKS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 3 AM MON...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER THIS WEEKEND.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS IN THE UPR 60S TO LOW 70S TUE AND LOWS MID 40S INLAND
TO LOWER 50S CST. A FEW DEGREES COOLER FOR WED WITH LOW LEVEL NE/E
FLOW...HIGHS 60-70 DEG.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT...AS WARM FRONT LIFTS THROUGH THE AREA...AHEAD OF DEEP
BROAD UPPER TROF AND COLD FRONT TO THE W. COULD SEE NON-DIURNAL
TEMP CURVE AS SLY FLOW DEVELOPS. CHC POPS PROGGED TO DEVELOP
LATER WED NIGHT DEEP INLAND AND ALONG THE SOUTHERN COAST. PRECIP
CONTINUES OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING
PLENTY OF MOISTURE AND QPF. WILL CONTINUE LIKELY POPS THU AND THU
NIGHT. PERIODS OF HEAVY RAIN WILL BE POSSIBLE...WITH FORECAST
SOUNDINGS SHOWING PWAT VALUES INCREASING TO AROUND 1.75". DID ADD
ISO TSTM MENTION THU...WITH GFS SHOWING SOME MODEST INSTABILITY
DEVELOPING. MODEL DIFFERENCES CONTINUE WITH JUST HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE MOVES OFFSHORE
LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING ALOFT AND THE UPPER
TROF AXIS REMAINING W OF THE REGION. ULTIMATELY IT WILL DEPEND ON
THE TIMING OF AN EMBEDDED SHORTWAVE MOVING THROUGH THE SW FLOW
ALOFT. 00Z MODELS CONTINUE TO TREND SLOWER PUSHING THE FRONT
THROUGH AND DEEPER MOISTURE OFFSHORE AND WILL CONTINUE CHC POPS
FRI MORNING WITH GRADUAL CLEARING FROM THE WEST THROUGH THE
AFTERNOON/EVENING. IT WILL REMAIN MILD AHEAD OF FRONT WITH HIGHS
THU IN THE UPPER 60S TO LOW 70S...AND LOWS THU NIGHT IN THE 50S. A
FEW DEGREES COOLER FOR FRI...THOUGH WILL DEPEND ON HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA.
FRIDAY NIGHT THROUGH SUNDAY...STRONG CAA DEVELOPS BEHIND THE
FRONT THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING
INTO THE REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT
AFTERNOON THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS
MOVING ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE
AREA THIS WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S
INLAND TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING
TEMPS EXPECTED INLAND. HIGHS SAT AND SUN IN THE UPPER 40S/50
DEGREES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 715 AM MONDAY...LIGHT SOUTHERLY WINDS AND INCREASED MID/HIGH
CLOUDS HAS HELPED DISSIPATE THE PATCHY FOG AND VFR CONDITIONS
SHOULD PREVAIL FOR THE BALANCE OF THE MORNING. HAVE INCLUDED
VICINITY SHOWERS DURING THE AFTERNOON FOLLOWED BY A PERIOD OF MVFR
CEILINGS BEFORE DOWNSLOPING FLOW AND ADVECTION OF DRIER AIR LEADS
TO RAPID CLEARING TOWARD MORNING ON TUESDAY. S/SW WINDS WILL
INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY THIS
AFTERNOON.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...PRED VFR TUE THRU WED AS HIGH PRES BUILDS INTO
THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT WINDS
AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO FRI
WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING UPR
TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE MOVES OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 715 AM MONDAY...NO REAL CHANGES TO MARINE FORECAST. S/SW
WINDS CONTINUE AT 10 KNOTS OR LESS WITH HIGHER GUSTS AROUND
DIAMOND BUOY. THIS IS DRIVING SEAS OF 2 TO 4 FEET WITH 12-14
SECOND WAVE PERIODS. AS THE COLD FRONT APPROACHES...WINDS WILL
INCREASE TO 20-25 KNOTS OVER THE COASTAL WATERS BY EARLY AFTERNOON
WITH FREQUENT GUSTS TO 25 KNOTS LIKELY ON PAMLICO SOUND THROUGH
TONIGHT. SEAS BUILD TO 5-8 FEET CENTRAL AND NORTHERN WATERS WITH
4-6 FEET SOUTHERN WATERS THIS AFTERNOON THROUGH TONIGHT.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...GUSTY WESTERLY WINDS AND ELEVATED SEAS WILL START
OFF THE PERIOD TUE MORNING. SCA CONDITIONS WILL CONTINUE ACROSS
THE WATERS SOUTH OF OREGON INLET INTO TUESDAY AFTERNOON...GRADUALLY
IMPROVING THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE
WEST INTO WED. WINDS GRADUALLY DIMINISHING TO BELOW 15 KT TUE
AFTERNOON. SEAS WILL SUBSIDE TO 2 TO 4 FEET LATE TUE AND BY WED
SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD FRONT WILL BE
APPROACHING FROM THE W THU WITH S WINDS INCREASING TO 15 TO 25
KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS BUILDING TO 4-8
FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE CENTRAL AND
SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT DECREASE IN
WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE CONDITIONS
BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES CONTINUE
WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT STRONG
CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA PROBABLE FOR
MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
.CLIMATE...
RECORD MAX TEMPS FOR 12/14 TODAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 1 PM EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...SK/CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
324 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA FRIDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 315 AM MONDAY...LOW-LEVEL MOISTURE WILL CONTINUE TO STEADILY
INCREASE THROUGH THE DAY AHEAD OF COLD FRONT AS PRECIPITABLE WATER
VALUES FROM THE HRRR MODEL SURGES TO NEAR 2 INCHES BY LATE
AFTERNOON. RADAR REFLECTIVITY PROGS FROM HRRR/RAP AND 4KM NAM DO
NOT SHOW MUCH IN THE WAY OF PRECIPITATION BEFORE ABOUT 18Z WITH
SHOWERS MOVING IN AFTER THAT AND CONTINUING INTO THE EVENING. PER
FORECAST SOUNDINGS...INSTABILITY IS LIMITED BUT WITH WARM HIGH
TEMPERATURES WELL INTO THE 70S...CONTINUED THE MENTION OF A SMALL
THREAT OF THUNDER TODAY. WOULD EXPECT THE HEAVIEST OF ANY RAIN
THAT FALLS TODAY TO BE NEAR THE COAST.
&&
.SHORT TERM /TONIGHT/...
AS OF 320 AM MONDAY...RAIN WILL LINGER NEAR THE COAST THROUGH
ABOUT MIDNIGHT BEFORE RAPID CLEARING OCCURS BETWEEN 06Z AND 12Z
WITH DOWNSLOPING FLOW AND LOWERING DEWPOINTS. LOWS TONIGHT WILL BE
IN THE 50S AREA-WIDE...EXCEPT LOWER 60S ALONG THE OUTER BANKS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 3 AM MON...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER THIS WEEKEND.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS IN THE UPR 60S TO LOW 70S TUE AND LOWS MID 40S INLAND
TO LOWER 50S CST. A FEW DEGREES COOLER FOR WED WITH LOW LEVEL NE/E
FLOW...HIGHS 60-70 DEG.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT...AS WARM FRONT LIFTS THROUGH THE AREA...AHEAD OF DEEP
BROAD UPPER TROF AND COLD FRONT TO THE W. COULD SEE NON-DIURNAL
TEMP CURVE AS SLY FLOW DEVELOPS. CHC POPS PROGGED TO DEVELOP
LATER WED NIGHT DEEP INLAND AND ALONG THE SOUTHERN COAST. PRECIP
CONTINUES OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING
PLENTY OF MOISTURE AND QPF. WILL CONTINUE LIKELY POPS THU AND THU
NIGHT. PERIODS OF HEAVY RAIN WILL BE POSSIBLE...WITH FORECAST
SOUNDINGS SHOWING PWAT VALUES INCREASING TO AROUND 1.75". DID ADD
ISO TSTM MENTION THU...WITH GFS SHOWING SOME MODEST INSTABILITY
DEVELOPING. MODEL DIFFERENCES CONTINUE WITH JUST HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE MOVES OFFSHORE
LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING ALOFT AND THE UPPER
TROF AXIS REMAINING W OF THE REGION. ULTIMATELY IT WILL DEPEND ON
THE TIMING OF AN EMBEDDED SHORTWAVE MOVING THROUGH THE SW FLOW
ALOFT. 00Z MODELS CONTINUE TO TREND SLOWER PUSHING THE FRONT
THROUGH AND DEEPER MOISTURE OFFSHORE AND WILL CONTINUE CHC POPS
FRI MORNING WITH GRADUAL CLEARING FROM THE WEST THROUGH THE
AFTERNOON/EVENING. IT WILL REMAIN MILD AHEAD OF FRONT WITH HIGHS
THU IN THE UPPER 60S TO LOW 70S...AND LOWS THU NIGHT IN THE 50S. A
FEW DEGREES COOLER FOR FRI...THOUGH WILL DEPEND ON HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA.
FRIDAY NIGHT THROUGH SUNDAY...STRONG CAA DEVELOPS BEHIND THE
FRONT THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING
INTO THE REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT
AFTERNOON THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS
MOVING ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE
AREA THIS WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S
INLAND TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING
TEMPS EXPECTED INLAND. HIGHS SAT AND SUN IN THE UPPER 40S/50
DEGREES.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 1 AM MONDAY...DECK OF CLOUDS AROUND 5K FEET CONTINUES BUT
WITH A FEW BREAKS IN THAT DECK...MAY STILL SEE SOME PATCHES OF
MVFR AND PERHAPS IFR FOG THROUGH THE EARLY MORNING HOURS...BUT
OVERALL CLOUD COVER WILL INHIBIT THE FOG A BIT. EXPECT MOSTLY VFR
CONDITIONS THROUGH THE DAY MONDAY UNTIL 06Z MONDAY NIGHT WITH JUST
A FEW SHOWERS IN THE VICINITY OF THE TAF SITES...BUT PROBABLY NOT
HEAVY ENOUGH TO PRODUCE MANY REDUCTIONS IN CEILINGS OR VSBY. S/SW
WINDS WILL INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY
THIS AFTERNOON.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...PRED VFR TUE THRU WED AS HIGH PRES BUILDS INTO
THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT WINDS
AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO FRI
WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING UPR
TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE MOVES OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 320 AM MONDAY...S/SW WINDS ARE RUNNING 10 KNOTS OR LESS THIS
MORNING EXCEPT GUSTING INTO THE UPPER TEENS AT DIAMOND BUOY. THIS
IS DRIVING SEAS OF 2 TO 4 FEET WITH 12-14 SECOND WAVE PERIODS. AS
THE COLD FRONT APPROACHES...WINDS WILL INCREASE TO 20-25 KNOTS
OVER THE COASTAL WATERS BY EARLY AFTERNOON WITH FREQUENT GUSTS TO
25 KNOTS LIKELY ON PAMLICO SOUND THROUGH TONIGHT. SEAS BUILD TO
5-8 FEET CENTRAL AND NORTHERN WATERS WITH 4-6 FEET SOUTHERN WATERS
THIS AFTERNOON THROUGH TONIGHT.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...GUSTY WESTERLY WINDS AND ELEVATED SEAS WILL START
OFF THE PERIOD TUE MORNING. SCA CONDITIONS WILL CONTINUE ACROSS
THE WATERS SOUTH OF OREGON INLET INTO TUESDAY AFTERNOON...GRADUALLY
IMPROVING THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE
WEST INTO WED. WINDS GRADUALLY DIMINISHING TO BELOW 15 KT TUE
AFTERNOON. SEAS WILL SUBSIDE TO 2 TO 4 FEET LATE TUE AND BY WED
SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD FRONT WILL BE
APPROACHING FROM THE W THU WITH S WINDS INCREASING TO 15 TO 25
KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS BUILDING TO 4-8
FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE CENTRAL AND
SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT DECREASE IN
WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE CONDITIONS
BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES CONTINUE
WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT STRONG
CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA PROBABLE FOR
MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
.CLIMATE...
RECORD MAX TEMPS FOR 12/14 TODAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 1 PM EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...SK/CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
105 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA LATE THURSDAY
NIGHT OR FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM MONDAY...CLOUDINESS CONTINUES TO INCREASE FROM THE SW/W
EARLY THIS MORNING. SOME PATCHES OF FOG ARE POSSIBLE BUT SHOULD BE
INHIBITED A BIT BY THE CLOUD COVER. LATEST RUNS OF THE 3KM HRRR
AND RAP MODELS SHOW NO PRECIPITATION INTO OUR CWA UNTIL AFTER 18Z
TODAY...SO HAVE TWEAKED POPS TO REFLECT THIS. OTHERWISE NO MAJOR
CHANGES NEEDED TO CURRENT FORECAST. LIGHT S/SW WINDS WILL KEEP LOW
TEMPERATURES IN THE UPPER 50S TO LOWER 60S AREA-WIDE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
AS OF 230 PM SUNDAY...WEAK COLD FRONT WILL APPROACH FROM THE W
WITH MOISTURE GRAD INCREASING OVER THE AREA. MDLS CONT TO SLOW
ARRIVAL OF SCT SHRA SO DROPPED ALL PRECIP THRU MORN. GIVEN WARM
START AND POSS SOME SUN THRU MORN EXPECT ANOTHER VERY WARM DAY
WITH HIGHS WELL INTO THE 70S. STILL DOESNT LOOK LIKE MUCH PRECIP
WITH THIS SYSTEM SO CONT CHC POPS. WEAK INSTAB STILL DVLPS SO CONT
ISOLD TSRA MENTION. SSW WINDS WILL BECOME GUSTY ESPCLY CST.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 315 PM SUN...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER NEXT WEEKEND.
MONDAY NIGHT...PRECIP WILL TAPER OFF FROM WEST TO EAST MONDAY
EVENING WITH A WEAK COLD FRONT MOVING THROUGH AFTER MIDNIGHT AND
CLEARING SKIES LATE. LIMITED CAA BEHIND FRONT WILL KEEP LOWS
MILD WITH MID 50S INLAND TO UPR 50S CST.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS UPR 60S TO LOW 70S AND LOWS MID 40S INLAND TO LOWER
50S CST.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT AHEAD OF DEEP BROAD UPPER TROF AND COLD FRONT TO THE W.
CHC POPS PROGGED TO DEVELOP LATER WED NIGHT ESPCLY INLAND. PRECIP
CONT OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING PLENTY
OF MOISTURE AND QPF. MODEL DIFFERENCES CONTINUE WITH JUST HOW
QUICKLY THE FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE
MOVES OFFSHORE LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING
ALOFT AND THE UPPER TROF AXIS REMAINING W OF THE REGION.
ULTIMATELY IT WILL DEPEND ON THE TIMING OF AN EMBEDDED SHORTWAVE
MOVING THROUGH THE SW FLOW ALOFT. 12Z MODELS ARE A BIT SLOWER
PUSHING THE FRONT THROUGH AND DEEPER MOISTURE OFFSHORE AND HAVE
CONTINUED CHC POPS FRI MORNING WITH GRADUAL CLEARING FROM THE WEST
THROUGH THE AFTERNOON. IT WILL REMAIN MILD AHEAD OF FRONT WITH
HIGHS THU AGAIN MAINLY 65 TO 70 AND LOWS WED NIGHT AND THU NIGHT
IN THE 50S.
FRIDAY NIGHT THRU SUNDAY...STRONG CAA DEVELOPS BEHIND THE FRONT
THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING INTO THE
REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT AFTERNOON
THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS MOVING
ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE AREA
FOR THE WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S INLAND
TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING TEMPS
EXPECTED INLAND. HIGHS SAT EXPECTED TO BE AROUND 50 WITH MID TO
UPPER 40S ON SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 1 AM MONDAY...DECK OF CLOUDS AROUND 5K FEET CONTINUES BUT
WITH A FEW BREAKS IN THAT DECK...MAY STILL SEE SOME PATCHES OF
MVFR AND PERHAPS IFR FOG THROUGH THE EARLY MORNING HOURS...BUT
OVERALL CLOUD COVER WILL INHIBIT THE FOG A BIT. EXPECT MOSTLY VFR
CONDITIONS THROUGH THE DAY MONDAY UNTIL 06Z MONDAY NIGHT WITH JUST
A FEW SHOWERS IN THE VICINITY OF THE TAF SITES...BUT PROBABLY NOT
HEAVY ENOUGH TO PRODUCE MANY REDUCTIONS IN CEILINGS OR VSBY. S/SW
WINDS WILL INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY
THIS AFTERNOON.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM SUN...PERIODS OF SUB-VFR CIGS WITH A FEW SHOWERS MAY
LINGER INTO MONDAY EVENING BUT GENERALLY EXPECT CLEARING
CONDITIONS OVERNIGHT. PRED VFR TUE THRU WED AS HIGH PRES BUILDS
INTO THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT
WINDS AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO
EARLY FRI WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING
UPR TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH MON/...
AS OF 105 AM MONDAY...LIGHT S/SW WINDS CONTINUE AT 10 KNOTS OR
LESS EXCEPT WITH GUSTS TO AROUND 15 KNOTS AT DIAMOND BUOY. SEAS
ARE IN THE 2 TO 4 FOOT RANGE WITH STILL SOME 11-13 SECOND
SWELLS...ESPECIALLY CENTRAL AND NORTHERN WATERS. NO BIG CHANGES TO
THE FORECAST AS WINDS GRADUALLY INCREASE ON MONDAY AS A COLD FRONT
APPROACHES...WITH 20 TO 25 KTS MOST WTRS BY MONDAY AFTERNOON. SEAS
SHOULD BUILD THRU THE DAY REACHING 6 TO 8 FEET OUTER WTRS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM SUN...SCA CONDITIONS EXPECTED TO CONTINUE ACROSS
PORTIONS OF THE WATERS MON NIGHT THROUGH TUE MORNING. SSW WINDS
AROUND 15-25 KT VEER TO SW MON EVENING...THEN TO W AFTER FROPA
LATE MON NIGHT...THEN GRADUALLY DIMINISH THROUGH THE DAY TUE. SEAS
EXPECTED TO PEAK AROUND 5-8 FT MON NIGHT...THE SUBSIDE TO BLO 6 FT
TUE AFTERNOON.
HIGH PRES WILL BUILD ACROSS THE WATERS LATE TUE THROUGH WED WITH
WINDS DIMINISHING TO BELOW 15 KT. SEAS WILL SUBSIDE TO 2 TO 4
FEET LATE TUE AND BY WED SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD
FRONT WILL BE APPROACHING FROM THE W THU WITH S WINDS INCREASING
TO 15 TO 25 KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS
BUILDING TO 4-7 FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE
CENTRAL AND SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT
DECREASE IN WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE
CONDITIONS BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES
CONTINUE WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT
STRONG CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA
PROBABLE MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
RECORD MAX TEMPS FOR 12/14 MONDAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO NOON EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF/JBM
LONG TERM...SK/CQD
AVIATION...CTC/JBM
MARINE...CTC/JBM/SK
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
943 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 943 PM CST TUE DEC 15 2015
SNOW IS RAPIDLY FILLING IN OVER SOUTH CENTRAL ND AND THE JAMES
RIVER VALLEY AS OF 03 UTC AS DEFORMATION INCREASES IN ADVANCE OF
THE NORTHWARD-ADVANCING DRY SLOT OBSERVED OVER EASTER SD. THE 00
UTC NAM AND ALL OF THE HRRR/RAP AND ESRL HRRR SIMULATIONS SINCE
LATE AFTERNOON HAVE SUGGESTED THE AXIS OF HEAVIEST MOISTURE WILL
BE SLIGHTLY WEST OF EARLIER EXPECTATIONS BY ABOUT A COUNTY OR SO.
THAT IS PLAUSIBLE BASED ON UPSTREAM OBSERVATIONS OF THE DRY SLOT.
THEREFORE...WE ADJUSTED TOTAL SNOWFALL AMOUNTS SLIGHTLY WITH THIS
UPDATE TO ADVERTISE THE HEAVIEST AMOUNTS OF 6 TO 10 INCHES IN THE
LINTON...ASHLEY AND STEELE AREAS...WITH A BIT LOWER AMOUNTS FROM
5 TO 8 INCHES IN THE JAMES RIVER VALLEY. MODEL-FORECAST SOUNDINGS
SUGGEST THAT OMEGA WILL BE MAXIMIZED IN THE DENDRITIC GROWTH ZONE
WITHIN THE BAND OF HEAVIEST SNOW...POSSIBLY CAUSING SNOW-TO-LIQUID
RATIOS TO EXCEED 20 TO 1 FOR A TIME IN SPOTS.
WE ARE NOT MAKING ANY CHANGES TO THE ADVISORY/WARNING LAYOUT WITH
THIS UPDATE. HOWEVER...SNOW TOTALS IN BISMARCK COULD VERY WELL BE
ON THE HIGH END OF THE ADVERTISED 4 TO 6 INCH RANGE FOR THE CITY.
MOREOVER...EASTERN PARTS OF BURLEIGH COUNTY WILL LIKELY HAVE MORE
SNOWFALL...AS PLACES LIKE STERLING MAY WIND UP IN THE AXIS OF THE
HEAVIEST SNOW. SINCE THE PRIMARY POPULATION CENTER IS CURRENTLY
EXPECTED TO BE JUST BELOW OR NEAR LOW-END WARNING CRITERIA OF 6
INCHES OF SNOW IN 12 HOURS...WE CHOSE TO LEAVE BURLEIGH COUNTY IN
A WINTER WEATHER ADVISORY FOR NOW...BUT WILL CONTINUE MONITORING
TRENDS.
UPDATE ISSUED AT 642 PM CST TUE DEC 15 2015
WE MADE ANOTHER MINOR UPDATE TO FURTHER REFINE/SLIGHTLY SLOW DOWN
THE RAMP-UP IN THE HOURLY CHANCE OF SNOW ACROSS THE JAMES RIVER
VALLEY IN A COLLABORATIVE EFFORT WITH THE NWS OFFICE IN GRAND
FORKS.
UPDATE ISSUED AT 549 PM CST TUE DEC 15 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE CYCLE OTHER THAN TO USE A
TIME-LAGGED ENSEMBLE OF RECENT HRRR AND WRF-ARW/WRF-NMM MODEL RUNS
TO SLOW THE ADVANCE OF SNOW INTO THE AREA SLIGHTLY. REGARDLESS...A
LARGE AREA OF MODERATE TO HEAVY SNOW IN SD IS LIFTING NORTH AND IS
ON TRACK TO ENTER SOUTHERN ND BY MID TO LATE EVENING. WE DO SEE A
SUBTLE TREND WESTWARD IN THE MOST RECENT HRRR/RAP SIMULATIONS WITH
RESPECT TO THE POSITION OF THE DEFORMATION BAND AND THUS HEAVIEST
SNOW WITH THE INCOMING SYSTEM...WHICH WILL REQUIRE MONITORING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
MAIN ISSUE IN THE SHORT TERM IS THE WINTER STORM. LATEST MODEL
GUIDANCE NOW PLACES THE HEAVIEST SNOW THROUGH THE JAMES RIVER
VALLEY BEGINNING THIS EVENING THROUGH WEDNESDAY. MODEL SOUNDINGS
SUGGEST THIS AREA WILL HAVE A DEEP DENDRITIC GROWTH ZONE OF -10 TO
-20C WITH THE HEAVIEST SNOW IS EXPECTED ROUGHLY BETWEEN MIDNIGHT
NOON WEDNESDAY.
MODELS ALSO SHOW A DEFORMATION ZONE SHOULD FOCUS DEEP LIFT AND
FOCUS THE HEAVIEST SNOW IN THE JAMES RIVER VALLEY.
WINDS WILL NOT BE SUFFICIENT TO CREATE BLOWING/DRIFTING SNOW AS
EXPECT THE CHARACTER OF THE SNOW TO BE A BIT WETTISH.
LIGHT SNOW WITH LITTLE ACCUMULATION IS EXPECTED NORTH CENTRAL AND
NORTHWEST WITH THE SOUTHWEST IN A LOW END ADVISORY AROUND 3 OR 4
INCHES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
SOME SCATTERED LIGHT SNOW WILL LINGER WEDNESDAY NIGHT...THEN COLD
AIR ARRIVES THURSDAY AND FRIDAY.
HIGH PRESSURE AND COLD AIR ADVECTION WILL PUSH INTO NORTH DAKOTA
THURSDAY AND FRIDAY. TEMPERATURES AROUND ZERO ARE EXPECTED FOR
OVERNIGHT LOWS FRIDAY WITH TEMPERATURES IN THE TEENS FOR HIGHS.
WARM AIR ADVECTION KICKS IN THIS WEEKEND AS LOW PRESSURE DEVELOPS
IN MONTANA AND WINDS SHIFT OUT OF THE SOUTH. TEMPERATURES WILL
LIKELY REBOUND INTO THE 30S ACROSS LOCATIONS WITH MINOR SNOWPACK.
MORE ACTIVE WEATHER IS POSSIBLE NEXT WEEK WITH SEVERAL WAVES
INDICATED BY THE LONG TERM MODELS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 943 PM CST TUE DEC 15 2015
WIDESPREAD IFR TO LIFR CONDITIONS WITH LOW CEILINGS AND/OR REDUCED
VISIBILITY IN SNOW ARE EXPECTED AT MOST LOCATIONS ACROSS WESTERN
AND CENTRAL ND TONIGHT INTO WEDNESDAY. SNOW WILL BE HEAVIEST OVER
PARTS OF SOUTH CENTRAL ND INTO THE JAMES RIVER VALLEY. NORTHWEST
WINDS WILL INCREASE BY WEDNESDAY TOO WITH GUSTS TO AROUND 25 KT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR NDZ023-025-036-
037-045>048-050-051.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ WEDNESDAY FOR
NDZ005-013-022-034-035-040>044.
&&
$$
UPDATE...CJS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
642 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 642 PM CST TUE DEC 15 2015
WE MADE ANOTHER MINOR UPDATE TO FURTHER REFINE/SLIGHTLY SLOW DOWN
THE RAMP-UP IN THE HOURLY CHANCE OF SNOW ACROSS THE JAMES RIVER
VALLEY IN A COLLABORATIVE EFFORT WITH THE NWS OFFICE IN GRAND
FORKS.
UPDATE ISSUED AT 549 PM CST TUE DEC 15 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE CYCLE OTHER THAN TO USE A
TIME-LAGGED ENSEMBLE OF RECENT HRRR AND WRF-ARW/WRF-NMM MODEL RUNS
TO SLOW THE ADVANCE OF SNOW INTO THE AREA SLIGHTLY. REGARDLESS...A
LARGE AREA OF MODERATE TO HEAVY SNOW IN SD IS LIFTING NORTH AND IS
ON TRACK TO ENTER SOUTHERN ND BY MID TO LATE EVENING. WE DO SEE A
SUBTLE TREND WESTWARD IN THE MOST RECENT HRRR/RAP SIMULATIONS WITH
RESPECT TO THE POSITION OF THE DEFORMATION BAND AND THUS HEAVIEST
SNOW WITH THE INCOMING SYSTEM...WHICH WILL REQUIRE MONITORING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
MAIN ISSUE IN THE SHORT TERM IS THE WINTER STORM. LATEST MODEL
GUIDANCE NOW PLACES THE HEAVIEST SNOW THROUGH THE JAMES RIVER
VALLEY BEGINNING THIS EVENING THROUGH WEDNESDAY. MODEL SOUNDINGS
SUGGEST THIS AREA WILL HAVE A DEEP DENDRITIC GROWTH ZONE OF -10 TO
-20C WITH THE HEAVIEST SNOW IS EXPECTED ROUGHLY BETWEEN MIDNIGHT
NOON WEDNESDAY.
MODELS ALSO SHOW A DEFORMATION ZONE SHOULD FOCUS DEEP LIFT AND
FOCUS THE HEAVIEST SNOW IN THE JAMES RIVER VALLEY.
WINDS WILL NOT BE SUFFICIENT TO CREATE BLOWING/DRIFTING SNOW AS
EXPECT THE CHARACTER OF THE SNOW TO BE A BIT WETTISH.
LIGHT SNOW WITH LITTLE ACCUMULATION IS EXPECTED NORTH CENTRAL AND
NORTHWEST WITH THE SOUTHWEST IN A LOW END ADVISORY AROUND 3 OR 4
INCHES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
SOME SCATTERED LIGHT SNOW WILL LINGER WEDNESDAY NIGHT...THEN COLD
AIR ARRIVES THURSDAY AND FRIDAY.
HIGH PRESSURE AND COLD AIR ADVECTION WILL PUSH INTO NORTH DAKOTA
THURSDAY AND FRIDAY. TEMPERATURES AROUND ZERO ARE EXPECTED FOR
OVERNIGHT LOWS FRIDAY WITH TEMPERATURES IN THE TEENS FOR HIGHS.
WARM AIR ADVECTION KICKS IN THIS WEEKEND AS LOW PRESSURE DEVELOPS
IN MONTANA AND WINDS SHIFT OUT OF THE SOUTH. TEMPERATURES WILL
LIKELY REBOUND INTO THE 30S ACROSS LOCATIONS WITH MINOR SNOWPACK.
MORE ACTIVE WEATHER IS POSSIBLE NEXT WEEK WITH SEVERAL WAVES
INDICATED BY THE LONG TERM MODELS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 549 PM CST TUE DEC 15 2015
WIDESPREAD IFR TO LIFR CONDITIONS WITH LOW CEILINGS AND/OR REDUCED
VISIBILITY IN SNOW ARE EXPECTED AT MOST LOCATIONS ACROSS WESTERN
AND CENTRAL ND TONIGHT INTO WEDNESDAY. SNOW WILL BE HEAVIEST OVER
PARTS OF SOUTH CENTRAL ND INTO THE JAMES RIVER VALLEY. NORTHWEST
WINDS WILL INCREASE BY WEDNESDAY TOO WITH GUSTS TO AROUND 25 KT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR NDZ023-025-036-
037-045>048-050-051.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ WEDNESDAY FOR
NDZ005-013-022-034-035-040>044.
&&
$$
UPDATE...CJS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
549 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 549 PM CST TUE DEC 15 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE CYCLE OTHER THAN TO USE A
TIME-LAGGED ENSEMBLE OF RECENT HRRR AND WRF-ARW/WRF-NMM MODEL RUNS
TO SLOW THE ADVANCE OF SNOW INTO THE AREA SLIGHTLY. REGARDLESS...A
LARGE AREA OF MODERATE TO HEAVY SNOW IN SD IS LIFTING NORTH AND IS
ON TRACK TO ENTER SOUTHERN ND BY MID TO LATE EVENING. WE DO SEE A
SUBTLE TREND WESTWARD IN THE MOST RECENT HRRR/RAP SIMULATIONS WITH
RESPECT TO THE POSITION OF THE DEFORMATION BAND AND THUS HEAVIEST
SNOW WITH THE INCOMING SYSTEM...WHICH WILL REQUIRE MONITORING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
MAIN ISSUE IN THE SHORT TERM IS THE WINTER STORM. LATEST MODEL
GUIDANCE NOW PLACES THE HEAVIEST SNOW THROUGH THE JAMES RIVER
VALLEY BEGINNING THIS EVENING THROUGH WEDNESDAY. MODEL SOUNDINGS
SUGGEST THIS AREA WILL HAVE A DEEP DENDRITIC GROWTH ZONE OF -10 TO
-20C WITH THE HEAVIEST SNOW IS EXPECTED ROUGHLY BETWEEN MIDNIGHT
NOON WEDNESDAY.
MODELS ALSO SHOW A DEFORMATION ZONE SHOULD FOCUS DEEP LIFT AND
FOCUS THE HEAVIEST SNOW IN THE JAMES RIVER VALLEY.
WINDS WILL NOT BE SUFFICIENT TO CREATE BLOWING/DRIFTING SNOW AS
EXPECT THE CHARACTER OF THE SNOW TO BE A BIT WETTISH.
LIGHT SNOW WITH LITTLE ACCUMULATION IS EXPECTED NORTH CENTRAL AND
NORTHWEST WITH THE SOUTHWEST IN A LOW END ADVISORY AROUND 3 OR 4
INCHES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
SOME SCATTERED LIGHT SNOW WILL LINGER WEDNESDAY NIGHT...THEN COLD
AIR ARRIVES THURSDAY AND FRIDAY.
HIGH PRESSURE AND COLD AIR ADVECTION WILL PUSH INTO NORTH DAKOTA
THURSDAY AND FRIDAY. TEMPERATURES AROUND ZERO ARE EXPECTED FOR
OVERNIGHT LOWS FRIDAY WITH TEMPERATURES IN THE TEENS FOR HIGHS.
WARM AIR ADVECTION KICKS IN THIS WEEKEND AS LOW PRESSURE DEVELOPS
IN MONTANA AND WINDS SHIFT OUT OF THE SOUTH. TEMPERATURES WILL
LIKELY REBOUND INTO THE 30S ACROSS LOCATIONS WITH MINOR SNOWPACK.
MORE ACTIVE WEATHER IS POSSIBLE NEXT WEEK WITH SEVERAL WAVES
INDICATED BY THE LONG TERM MODELS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 549 PM CST TUE DEC 15 2015
WIDESPREAD IFR TO LIFR CONDITIONS WITH LOW CEILINGS AND/OR REDUCED
VISIBILITY IN SNOW ARE EXPECTED AT MOST LOCATIONS ACROSS WESTERN
AND CENTRAL ND TONIGHT INTO WEDNESDAY. SNOW WILL BE HEAVIEST OVER
PARTS OF SOUTH CENTRAL ND INTO THE JAMES RIVER VALLEY. NORTHWEST
WINDS WILL INCREASE BY WEDNESDAY TOO WITH GUSTS TO AROUND 25 KT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR NDZ045>048-050-
051.
WINTER WEATHER ADVISORY UNTIL 5 PM MST WEDNESDAY FOR NDZ040-041-
043-044.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ WEDNESDAY FOR
NDZ005-013-022-034-035-042.
WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR NDZ023-025-036-
037.
&&
$$
UPDATE...CJS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
922 AM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 921 AM CST MON DEC 14 2015
THIS UPDATE TO TRIM THE DENSE FOG ADVISORY ACROSS THE JAMES RIVER
VALLEY WEST TO THE MISSOURI RIVER VALLEY. ALSO FAR SOUT5HWEST
NORTH DAKOTA HAVE SEEN VSBYS IMPROVE.
UPDATE ISSUED AT 655 AM CST MON DEC 14 2015
LATEST SENSIBLE WEATHER OBSERVATIONS FROM ACROSS THE REGION SHOW
IMPROVEMENT IN VISIBILITIES. HOWEVER...AREA WEBCAMS ARE STILL
SHOWING SOME FOG. WILL WAIT UNTIL AFTER SUNRISE TO SEE IF WE CAN
CANCEL AT LEAST A PORTION OF THE DENSE FOG ADVISORY.
SOME LIGHT REFLECTIVITIES LIFTING FROM NORTHEAST MONTANA INTO
NORTHWEST NORTH DAKOTA BUT AS OF YET NO GROUND TRUTH TO INDICATE
ANYTHING FALLING FROM THESE MID LEVEL REFLECTIVITIES. DO HAVE SOME
SLIGHT CHANCE POPS STARTING HERE THIS AFTERNOON...AND WILL LEAVE
THE MENTION OUT THIS MORNING FOR NOW.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY.
A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS ALL TERMINALS
EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK IN PLACE. CIGS/VSBYS WILL
IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z MONDAY...HOWEVER IFR
CIGS EXPECTED THROUGH THE TAF PERIOD WITH AREAS OF FOG RETURNING
AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-011>013-019>023-033-034-041-042-044-045.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
732 AM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 655 AM CST MON DEC 14 2015
LATEST SENSIBLE WEATHER OBSERVATIONS FROM ACROSS THE REGION SHOW
IMPROVEMENT IN VISIBILITIES. HOWEVER...AREA WEBCAMS ARE STILL
SHOWING SOME FOG. WILL WAIT UNTIL AFTER SUNRISE TO SEE IF WE CAN
CANCEL AT LEAST A PORTION OF THE DENSE FOG ADVISORY.
SOME LIGHT REFLECTIVITIES LIFTING FROM NORTHEAST MONTANA INTO
NORTHWEST NORTH DAKOTA BUT AS OF YET NO GROUND TRUTH TO INDICATE
ANYTHING FALLING FROM THESE MID LEVEL REFLECTIVITIES. DO HAVE SOME
SLIGHT CHANCE POPS STARTING HERE THIS AFTERNOON...AND WILL LEAVE
THE MENTION OUT THIS MORNING FOR NOW.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY.
A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS ALL TERMINALS
EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK IN PLACE. CIGS/VSBYS WILL
IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z MONDAY...HOWEVER IFR
CIGS EXPECTED THROUGH THE TAF PERIOD WITH AREAS OF FOG RETURNING
AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
404 AM CST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 352 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY. A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS
ALL TERMINALS EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING
DRIZZLE POSSIBLE AT ANYTIME WITH THE STRATUS AND FOG DECK IN
PLACE. CIGS/VSBYS WILL IMPROVE SOMEWHAT AT MOST TERMINALS AFTER
18Z MONDAY...HOWEVER IFR CIGS EXPECTED THROUGH THE TAF PERIOD WITH
AREAS OF FOG RETURNING AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1158 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 1158 PM CST SUN DEC 13 2015
LATEST SUITE OF SATELLITE IMAGERY AND SURFACE OBSERVATIONS IN
CONJUNCTION WITH THE HRRR CEILING AND VISIBILITY FORECAST IS ON
TRACK FOR THE OVERNIGHT PERIOD INTO MONDAY MORNING. EXPECTING THE
FAR NORTHWEST...WHICH INCLUDES WILLISTON...TO SUCCUMB TO THE
STRATUS AND FOG BY 10-11Z. NO CHANGES TO THE ONGOING DENSE FOG
ADVISORY.
UPDATE ISSUED AT 920 PM CST SUN DEC 13 2015
THE FORECAST FOR THE OVERNIGHT REMAINS ON TRACK AND BLENDED TO
OBSERVED TRENDS THROUGH 02-03 UTC. TEMPERATURES ACROSS THE TURTLE
MOUNTAINS INTO THE FAR UPPER JAMES RIVER BASIN HAVE LOCALLY
DROPPED INTO THE 10 TO 20 DEGREE RANGE. HOWEVER...THEY ARE
EXPECTED TO SLOWLY RISE THROUGH THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 603 PM CST SUN DEC 13 2015
DID ADD A PATCHY FREEZING DRIZZLE MENTION FOR MOST AREAS WITH
SATURATION WARMER THAN -10C...AND FAVORABLE WEAK EASTERLY UPSLOPE
FLOW. OTHERWISE...NO CHANGES NEEDED AS THE 20-22 UTC HRRR
ITERATIONS SUPPORT THE DENSE FOG CONTINUING THROUGH MONDAY
MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 325 PM CST SUN DEC 13 2015
MAIN CONCERNS CONTINUE TO BE DENSE FOG. PERSISTENCE SOUTHEAST LOW
LEVEL FLOW CONTINUES TO BE PORTRAYED BY NAM/GFS. EXPECT FOG WILL
REMAIN OR RETURN TO NEARLY ALL OF WEST AND CENTRAL NORTH DAKOTA
BY THIS EVENING AND OVERNIGHT.
HAVE ISSUED A DENSE FOG ADVISORY FOR ALL BUT THE FAR NORTHWEST
WHERE THE COOL MOIST BOUNDARY LAYER MAY NOT QUITE GET PUSHED INTO
THE AREA.
GOT A REPORT LIGHT DRIZZLE IN THE BISMARCK AREA AND WITH UPPER 70S
DEFINED AN AREA ACROSS CENTRAL NORTH DAKOTA WHERE VSBYS WILL BE
LOWEST THIS EVENING AND ADDED PATCHY FREEZING DRIZZLE. EVEN
WITHOUT THE FREEZING DRIZZLE FEEL THERE WOULD BE SUFFICIENT RIME
FOR SLIPPERY ROAD AS WELL.
MESO MODELS...HRRR/NAMNEST...SHOWING SOME VERY LIGHT QPF WEST
CENTRAL THIS EVENING. ADDED A SLIGHT CHANCE FOR FREEZING RAIN FAR
WEST CENTRAL TONIGHT THAT MATCHES UP WITH GLASGOW.
THE FOG WILL PERSIST INTO MONDAY WITH LITTLE CHANGE IN
TEMPERATURES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 PM CST SUN DEC 13 2015
THE HIGHLIGHT IN THE LONG TERM IS A STRONG STORM SYSTEM OVER THE
WEST COAST TODAY THAT IS EXPECTED TO CONTINUE TO DEVELOP...AND BRING
A STRONG STORM SYSTEM TO MUCH OF THE US THROUGH THE UPCOMING WEEK.
THIS SYSTEM WILL AFFECT WESTERN AND CENTRAL NORTH DAKOTA FROM MONDAY
NIGHT THROUGH WEDNESDAY NIGHT.
MONDAY NIGHT THE STRATUS AND LOW CLOUDS THAT HAVE PLAGUED THE AREA
THIS WEEKEND WILL STILL LINGER OVER CENTRAL NORTH DAKOTA. THE MODELS
ARE INDICATING SOME VERY LIGHT PRECIPITATION POSSIBLE AHEAD OF THE
ANTICIPATED STORM SYSTEM. THERE IS WEAK UPWARD MOTION IN THE
MODELS...AND WITH THE LACK OF MID LEVEL CLOUDS ALOFT AND BELOW
FREEZING TEMPERATURE PROFILES...EXPECT A LOWER LEVEL SUPERCOOLED
LAYER WITHIN THE STRATUS. BUFKIT SOUNDINGS SUPPORT THIS AND THUS
HAVE A MENTION OF AREAS OF FOG AND PATCHY FREEZING DRIZZLE MONDAY
NIGHT INTO TUESDAY MORNING FOR CENTRAL NORTH DAKOTA.
MONDAY NIGHT THE UPPER LEVEL TROUGH MOVES THROUGH THE SOUTHERN
ROCKIES WITH A SURFACE LOW DEVELOPING IN THE LEE OF THE COLORADO
ROCKIES. DETERMINISTIC MODELS ARE IN PRETTY GOOD AGREEMENT AT 12 UTC
TUESDAY WITH THE SURFACE AND 50H LOWS OVER THE PLAINS OF EASTERN
COLORADO. THE LOW TRACK MOVES NORTHEAST TO THE BORDER OF SD/MN/IA BY
DAYBREAK WEDNESDAY...AND ACROSS LAKE SUPERIOR INTO ONTARIO BY
DAYBREAK THURSDAY.
THE BEST FRONTOGENETICAL FORCING MOVES THROUGH THE FAR SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY AND DEVILS LAKE BASIN TUESDAY NIGHT
THROUGH WEDNESDAY MORNING...WITH THE DEFORMATION ZONE THEN SLOWLY
FADING FROM WEST TO EAST DURING THE DAY WEDNESDAY. WINDS WILL ALSO
PICK-UP ON THE BACK SIDE OF THE SURFACE SYSTEM ON WEDNESDAY BRINGING
A POSSIBILITY OF SOME BLOWING AND DRIFTING SNOW.
THE LATEST PRECIPITATION CONSENSUS WOULD BRING SNOW AMOUNTS IN THE
SOUTHWEST OF 3 TO 5 INCHES...OVER A PERIOD FROM MONDAY NIGHT THROUGH
WEDNESDAY - A 36-HOUR PERIOD OR SO. IN SOUTH CENTRAL NORTH
DAKOTA...HEAVIER SNOW TOTAL AMOUNTS OF 4 TO 7 INCHES ARE POSSIBLE IN
FROM A 36-HOUR PERIOD FROM TUESDAY THROUGH WEDNESDAY AFTERNOON. WILL
ISSUE A SPECIAL WEATHER STATEMENT REGARDING THE POTENTIAL WINTER-
TYPE PRECIPITATION/HAZARDS THAT MAY AFFECT MAINLY THE SOUTHERN HALF
OF OUR WESTERN/CENTRAL NORTH DAKOTA FORECAST AREA.
BEYOND THE MONDAY NIGHT-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO
THE REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20
ABOVE RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE
MOVE TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE
SHOULD BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1158 PM CST SUN DEC 13 2015
ALL TERMINALS EXCEPT KISN WILL CONTINUE TO HAVE LIFR/VLIFR CIGS
AND VSBYS RANGING BETWEEN IFR TO VLIFR THROUGH 18Z MONDAY. A
DENSE FOG ADVISORY IS IN EFFECT WHICH COVERS ALL TERMINALS EXCEPT
KISN AT THIS TIME. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK. CONDITIONS AT KISN WILL
DETERIORATE BY 10-11Z MONDAY...WITH LIFR CIGS AND MVFR VSBYS.
CIGS/VSBYS WILL IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z
MONDAY WITH IFR CIGS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ MONDAY FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1145 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 1145 PM CST SUN DEC 13 2015
ADDED FREEZING DRIZZLE POTENTIAL TO AREAS IN DENSE FOG ADVISORY
AFTER RECEIVING REPORT. INCLUDED IN BOTH THE GRIDS AND MENTIONED
IN THE DENSE FOG ADVISORY PRODUCT.
UPDATE ISSUED AT 917 PM CST SUN DEC 13 2015
TRIMMED DENSE FOG ADVISORY...LEAVING THE AREA OF GWINNER TO
LANGDON AND WEST BASICALLY. NOT SEEING MUCH EVIDENCE OF EASTWARD
EXPANSION...SO BELIEVE THAT TREND WILL CONTINUE AS PRESSURES FALL.
MOST FAVORABLE AREA FOR FOG WILL BE IN THE DEVILS LAKE BASIN WHERE
HIGH EXISTS AND WILL BE RETREATING NORTHWARD. DRIZZLE HAS BEEN
REPORTED ALSO IN PARTS OF THE RED RIVER VALLEY...WILL BE
MONITORING FOR FREEZING POTENTIAL.
UPDATE ISSUED AT 712 PM CST SUN DEC 13 2015
FORECAST LARGELY UNCHANGED WITH THIS UPDATE. ADDED PATCHY FREEZING
DRIZZLE TO FAR SE ND BASED ON REPORT. OTHERWISE...MAIN CONCERN
WILL BE EXTENT OF FOG OVER THE NEXT SEVERAL HOURS. OBSERVATIONS
HAVE INDICATED VISIBILITIES HAVE IMPROVED ACROSS THE I-29
CORRIDOR OVER THE PAST FEW HOURS. LATEST HRRR HAS AREA OF FOG
EXPANDING EASTWARD AGAIN. HOWEVER...WITH HIGH PRESSURE RIDGE AXIS
OVER DEVILS LAKE TO JAMESTOWN AND LOW PRESSURE MOVING INTO THE
AREA...THE GENERAL TREND OVER THE NEXT 12-18 HRS SHOULD BE FOR
IMPROVING CONDITIONS. SO WILL MONITOR TRENDS AND LATEST MODEL RUNS
AND CONSIDER TRIMMING ADVISORY IN THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM CST SUN DEC 13 2015
MAIN FORECAST CHALLENGE IN THE VERY NEAR TERM WILL BE THE THICKER
FOG THAT CONTINUES OVER PORTIONS OF THE FA. HAVE A DENSE FOG
ADVISORY OUT FOR PORTIONS OF THE FA AND WILL LIKELY HAVE TO
CONTINUE IT INTO TONIGHT AS WELL. TEMP/DEW POINT SPREADS REMAIN
VERY TIGHT AND WINDS LOOK TO REMAIN LOW. HIGH TEMPS GET UP RIGHT
AROUND 32F AGAIN ON MONDAY. THIS TIME WIND SPEEDS MAY BE HIGH
ENOUGH TO MIX OUT THE FOG. HOWEVER AT THIS POINT DID LEAVE PATCHY
FOG MENTIONED. THESE WINDS DO LIGHTEN UP AGAIN MON NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 PM CST SUN DEC 13 2015
NEXT SYSTEM BEGINS TO MOVE TOWARD THE FA ON TUE...BUT WILL ONLY
MAINTAIN PCPN CHANCES INTO THE SW. SFC LOW TRACKS FROM SW MN ON
12Z WED TO WESTERN LAKE SUPERIOR BY 00Z THU. MODELS SEEM FAIRLY
CONSISTENT ON PUSHING A DECENT SWATH OF SNOW THROUGH MOST OF THE
FA DURING THIS TIME FRAME...WITH THE LEAST WEST OF THE KDVL
REGION. WIND SPEEDS ALSO LOOK PRETTY GUSTY AS WELL. THE STEADIER
SNOW LIFTS NORTH AND EAST OF THE FA WED NIGHT INTO THU NIGHT BUT
SOME GUSTY WINDS WILL REMAIN. THIS SHOULD LEAD TO SOME BLOWING AND
DRIFTING SNOW. WILL ISSUE A SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THIS SYSTEM AND WILL WATCH AND SEE WHAT LATER RUNS HAVE
IN STORE.
FOR WED NIGHT THROUGH SUNDAY...THE POTENTIAL WINTER STORM WILL BE
WINDING DOWN WED NIGHT/THU. THE GFS MOVES THE STORM THROUGH A BIT
FASTER AND MOST OF THE ACCUMULATION WOULD BE DONE BY WED
NIGHT...WITH THE ECMWF A BIT SLOWER. WILL CONTINUE WITH THE ALLBLEND
SOLUTION. TEMPS WILL BE MUCH COOLER FOR FRI/SAT AND SHOULD BE BELOW
ZERO AT NIGHT GIVEN COLD AIRMASS AND FRESH SNOW. TEMPS SHOULD START
TO WARM BACK UP ABOVE NORMAL SUNDAY WITH UPPER RIDGING AND 850MB
TEMPS ABOVE 0C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CST SUN DEC 13 2015
CIGS WILL FLUCTUATE BETWEEN MVFR AND VLIFR AT MOST TAF SITES
TONIGHT. BELIEVE KDVL WILL STAY DOWN THOUGH...AND MAY SEE SOME
BRIEF -FZDZ YET TONIGHT. VIS WILL LIKELY STAY UP AT ALL BUT KDVL
AS PER LATEST GUIDANCE. MODELS POINT TOWARD CIGS IMPROVING TO
MVFR TODAY..MAINLY THIS AFTERNOON. HOWEVER...POTENTIAL WILL EXIST
FOR IFR CONDITIONS ONCE AGAIN MONDAY NIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR NDZ006-007-014-015-
024-026-028-029-038-049-052-054.
MN...NONE.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
627 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SLOWED PRECIP MOVEMENT SLIGHTLY. ALSO NEAR TERM HOURLY
TEMPS.
ORIGINAL...DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE
ENE ACROSS THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH
THE LOW WILL MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY
ABOUT 18Z AND EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN
MOVING INTO THE WESTERN COUNTIES AROUND 12Z...SPREADING EAST
ACROSS THE AREA THROUGH THE MORNING AND REACHING INTO NWRN PA
AROUND NOON. WILL CONTINUE WITH CAT POPS FOR THE REGION TODAY.
850MB JET INCREASES TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY
THROUGH THE DAY. WINDS SHOULD GET GUSTY LATE MORNING AND AFTERNOON
IN THE COLD ADVECTION. EXPECTING GUSTS INTO THE 30 TO 40 KNOT
RANGE BUT SHOULD REMAIN BELOW ADVISORY CRITERIA. HIGHS IN THE 60S
WITH FALLING TEMPS WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TODAY. WINDS ARE
EXPECTED TO SHIFT TO A SOUTHWESTERLY DIRECTION AFTER THE PASSAGE
OF THE FRONT. SHOWERS ASSOCIATED WITH THE FRONT COULD CAUSE SOME
BRIEF WIND GUSTS TO 35 KNOTS AT TOLEDO AND FINDLAY.
OTHERWISE...SHOWERS CAN BE EXPECTED ALL AREAS AS THE DAY
PROGRESSES. CEILINGS WILL BE DROPPING WITH TIME THROUGH THE DAY TO
MVFR AND POSSIBLY IFR. EXPECTING VCSH SHOWERS TOWARD THE END OF
THE PERIOD.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA. NON VFR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY IN
LAKE EFFECT SNOW.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SLOWED PRECIP MOVEMENT SLIGHTLY. ALSO NEAR TERM HOURLY
TEMPS.
ORIGINAL...DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE
ENE ACROSS THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH
THE LOW WILL MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY
ABOUT 18Z AND EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN
MOVING INTO THE WESTERN COUNTIES AROUND 12Z...SPREADING EAST
ACROSS THE AREA THROUGH THE MORNING AND REACHING INTO NWRN PA
AROUND NOON. WILL CONTINUE WITH CAT POPS FOR THE REGION TODAY.
850MB JET INCREASES TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY
THROUGH THE DAY. WINDS SHOULD GET GUSTY LATE MORNING AND AFTERNOON
IN THE COLD ADVECTION. EXPECTING GUSTS INTO THE 30 TO 40 KNOT
RANGE BUT SHOULD REMAIN BELOW ADVISORY CRITERIA. HIGHS IN THE 60S
WITH FALLING TEMPS WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VSBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...KEC
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
307 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE ENE ACROSS
THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH THE LOW WILL
MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY ABOUT 18Z AND
EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN MOVING INTO THE
WESTERN COUNTIES AROUND 12Z...SPREADING EAST ACROSS THE AREA
THROUGH THE MORNING AND REACHING INTO NWRN PA AROUND NOON. WILL
CONTINUE WITH CAT POPS FOR THE REGION TODAY. 850MB JET INCREASES
TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY THROUGH THE DAY. WINDS
SHOULD GET GUSTY LATE MORNING AND AFTERNOON IN THE COLD ADVECTION.
EXPECTING GUSTS INTO THE 30 TO 40 KNOT RANGE BUT SHOULD REMAIN
BELOW ADVISORY CRITERIA. HIGHS IN THE 60S WITH FALLING TEMPS
WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VSBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...KEC
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1159 PM EST SUN DEC 13 2015
.SYNOPSIS...
A COLD FRONT NEAR THE MISSISSIPPI RIVER WILL CROSS THE
REGION ON MONDAY AS STRONG LOW PRESSURE MOVES ACROSS THE CENTRAL
GREAT LAKES. HIGH PRESSURE WILL BUILD OVER THE AREA FROM THE SOUTH
TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE
REGION ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CLOUDS ARE HELPING TO KEEP THE TEMPS FROM DROPPING TOO MUCH.
STILL SOME PLACES HAVE ALREADY GOTTEN WITHING A DEGREE OR TWO OF
THE FORECAST LOW. WILL INCH THESE SPOTS DOWN ANOTHER DEGREE OR SO
TO ADD MORE OF A BUFFER.
A SPRINKLE COULD CLIP THE NW COUNTIES BUT THE HRRR AND RAP ARE
KEEPING MEASURABLE PRECIP OUT OF THE CWA THRU 12Z. BORDERING POPS
ARE SO HIGH...DON`T HAVE MUCH TO WORK WITH SO WILL RELUCTANTLY LEAVE
POP AS IS. AS THE LOW LEVEL JET INCREASES...WINDS WILL START TO PICK
UP TOWARD THE END OF THE NIGHT AND MAY BE GUSTING 20 TO 25 MPH IN
PARTS OF THE WEST AND ALONG THE LAKESHORE BY DAYBREAK.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AS
FAR AS THE MAIN SYNOPTIC FEATURES ARE CONCERNED. RAIN IS EXPECTED
TO RAPIDLY SPREAD ACROSS THE FORECAST AREA TOMORROW MORNING AHEAD
OF THE FRONT. THE FRONT WILL BE EAST OF THE AREA BY MID AFTERNOON.
A DRY SLOT BEHIND WILL SWING INTO THE AREA FROM THE SOUTHWEST
DURING THE AFTERNOON SO THERE MAY BE A DRY PERIOD FOR A FEW HOURS.
WRAP AROUND MOISTURE WILL INCREASE LATER IN THE DAY AND SOME MORE
LIGHT PRECIP IS POSSIBLE DURING THE EVENING BEFORE THE RAIN ENDS
ALTOGETHER OVERNIGHT. HIGH PRESSURE WILL RETURN FOR TUESDAY AND
TUESDAY NIGHT. IT WILL BE TOUGH TO SCOUR OUT THE LOW LEVEL
MOISTURE BUT AT LEAST SOME PARTIAL SUNSHINE IS LIKELY ALL AREAS.
HAVE CONTINUED THE TREND OF SLOWING DOWN THE NEXT SYSTEM AS WELL.
PRECIP CHANCES SHOULD HOLD OFF TILL LATE WEDNESDAY IN THE WEST AND
WEDNESDAY NIGHT ELSEWHERE. MOISTURE LOOKS SOMEWHAT LIMITED SO NO
MORE THAN CHANCE POPS NEEDED. THE SURFACE COLD FRONT RESPONSIBLE
FOR THE PRECIP WILL OVER THE AREA AT 12Z THURSDAY. UNBELIEVABLY
THERE WILL BE NO PRECIP TYPE CONCERNS WITH ALL RAIN EXPECTED.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST. NEXT STRONG COLD FRONT
MOVES ACROSS THE FORECAST AREA THURSDAY MORNING...USHERING MORE
SEASONAL CONDITIONS. MODELS ARE SIMILAR BUT GFS CONTINUES TO BE A
LITTLE FASTER THAN THE ECMWF. PROBABLY A BREAK IN THE PRECIP
THURSDAY AFTERNOON AND EVENING. COULD SEE A LITTLE LAKE EFFECT IN
THE EAST FRIDAY AS THE 850MB TEMPS DIP TO -10C. BEST CHANCE FOR
LAKE ENHANCED SNOW SHOWERS FRIDAY EVENING INTO THE OVERNIGHT WITH
SECONDARY SHOT OF COLD AIR. BY 12Z SATURDAY THE 850MB TEMPS
PLUNGE TO -12C TO -14C. SO FAR OUT WILL JUST GO WITH CHANCE POPS
HOWEVER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VISBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
SOUTH FLOW OVER THE LAKE WILL INCREASE OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. A SMALL CRAFT ADVISORY WILL BE NEEDED MONDAY AS A
STRONG COLD PUSHES ACROSS THE LAKE. THERE STILL IS A SMALL CHANCE
OF A PERIOD OF SUSTAINED GALE FORCE WINDS BUT NOT ENOUGH TO RAISE A
GALE WATCH. WINDS DIMINISH FROM THE WEST TUESDAY AFTERNOON AS HIGH
PRESSURE MOVES ACROSS THE LOWER LAKES. WINDS BACK TO THE SOUTH
WEDNESDAY AHEAD OF NEXT SYSTEM THAT WILL MOVE ACROSS THE LAKE ON
THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ADAMS/KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...KEC
MARINE...DJB
AREA FORECAST DISCUSSION
NWS MEDFORD OR
910 AM PST MON DEC 14 2015
.DISCUSSION...THE UPPER TROUGH HAS PUSHED SOUTHEAST INTO CENTRAL
NEVADA. ON THE BACKSIDE IS A MOIST NORTH TO NORTHWEST FLOW AND ONE
MORE DISTURBANCE WILL MOVE THROUGH THIS AFTERNOON BRINGING A NET
INCREASE IN SHOWER ACTIVITY MAINLY WEST OF THE CASCADES THIS
AFTERNOON. SNOW LEVELS SHOULD COME UP TO AROUND 2000 FEET THIS
AFTERNOON AND ROAD SURFACE WILL WARM UP TO LIMIT ANY ROAD SNOW
IMPACTS. THERE WON`T BE ENOUGH SNOW TO WARRANT A NEW ADVISORY AT
HIGHER ELEVATION SPOTS LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY
BE HAZARDOUS OVER THE PASS. PREVIOUS FORECAST FOR THIS MORNING IS
ON TRACK AND NO CHANGES ARE NEEDED.
ONE ITEM OF CONCERN FROM ABOUT MID WEEK INTO NEXT WEEKEND WILL BE
THE POTENTIAL FOR FLOODING. THE MODELS YESTERDAY AND SO FAR THIS
MORNING ARE HINTING AT ANOTHER SIGNIFICANT RAIN EVENT WITH HIGHER
SNOW LEVELS. WITH THE GROUND ALREADY SATURATED, MELTING SNOWPACK
AND HEAVY RAIN COULD VERY WELL RESULT IN RENEWED FLOODING
CONCERNS. -PETRUCELLI
&&
.AVIATION...FOR THE 14/12Z TAF CYCLE...NUMEROUS TO WIDESPREAD RAIN
AND SNOW SHOWERS FROM THE CASCADES WESTWARD ARE EXPECTED THROUGH
THIS AFTERNOON...THEN SHOWERS WILL BECOME SCATTERED DURING THE
EVENING. FROM THE CASCADES WEST...THIS WILL CREATE A MIX OF IFR AND
MVFR CIGS WITH PERIODS OF MOUNTAIN OBSCURATIONS THROUGH THIS
EVENING. EAST OF THE CASCADES...CONDITIONS WILL BE MAINLY VFR WITH
ISOLATED SNOW SHOWERS AND MVFR CEILINGS. SHOWERS WILL TAPER OFF
OVERNIGHT WITH VFR CONDITIONS DEVELOPING EXCEPT FOR IFR/MVFR VALLEY
LOW CLOUDS AND FOG FORMING WEST OF THE CASCADES AND POSSIBLY IN THE
KLAMATH BASIN. /CC
&&
.MARINE...UPDATED 800 AM PST MONDAY 14 DEC 2015...GUSTY NORTHWEST
WINDS WILL BRIEFLY LOWER LATE THIS MORNING THEN INCREASE AGAIN THIS
AFTERNOON THROUGH THIS EVENING. VERY STEEP SEAS WILL CONTINUE TODAY
INTO THIS EVENING. SEAS WILL GRADUALLY LOWER BUT WILL REMAIN STEEP
THROUGH TUESDAY MORNING. HIGH AND VERY LONG PERIOD SWELL IS EXPECTED
TO BUILD INTO THE WATERS WEDNESDAY MORNING. A SERIES OF FRONTS WILL
MOVE INTO THE AREA LATER HIS WEEK...WITH PERIODS OF STRONG GUSTY
SOUTH WINDS AND STEEP TO VERY STEEP SEAS EXPECTED. -BPN/CC
&&
.PREV DISCUSSION... /ISSUED 402 AM PST MON DEC 14 2015/
DISCUSSION...IN THE WAKE OF YESTERDAY`S STORM...WE ARE NOW IN
A COLD NORTH TO NORTHWEST FLOW ALOFT. THERE ARE STILL A COUPLE OF
DISTURBANCES THAT WILL MOVE THROUGH ON THE BACK SIDE OF AN UPPER
LEVEL TROUGH, THE AXIS OF WHICH IS CENTERED OVER IDAHO AND NEVADA
EARLY THIS MORNING.
THE FIRST DISTURBANCE IS MOVING THROUGH NOW WITH NUMEROUS SHOWERS
OCCURRING FROM THE CASCADES AND SISKIYOUS NORTH AND WEST. SNOW
LEVELS ARE RUNNING ABOUT 1500 TO 2000 FEET...THOUGH THEY COULD BE
LOCALLY DOWN AS LOW AS 1000 FEET IN HEAVIER SHOWERS. SOME SHOWERS
MAY ALSO MAKE IT SOUTH AND EAST OF THE MOUNTAINS, BUT THESE WILL
BE SCATTERED AT BEST. A WINTER WEATHER ADVISORY AT WSWMFR REMAINS
IN EFFECT THIS MORNING OVER THE WEST SIDE. THE BEST CHANCE FOR AN
INCH OR TWO OF NEW SNOW WILL BE ON THE NORTH AND WEST FACING
SLOPES OF JACKSON AND JOSEPHINE COUNTIES AS WELL AS THE UMPQUA
DIVIDE, MAINLY ABOVE 1500 FEET. THE MAIN PASSES ON INTERSTATE 5 IN
OREGON COULD BE IMPACTED BY THESE HEAVIER SNOW SHOWERS.
THE LATEST HRRR IS SHOWING ANOTHER DISTURBANCE MOVING IN THIS
AFTERNOON, WHICH WILL KEEP SHOWERS GOING INTO THE EVENING HOURS,
BUT SNOW LEVELS SHOULD RISE TO NEAR 2000 FEET WEST OF THE CASCADES
AND ROAD SURFACE TEMPERATURES SHOULD WARM ENOUGH TO PRECLUDE
SIGNIFICANT SNOW IMPACTS AT THE LOWER ELEVATIONS. THERE WON`T BE
ENOUGH SNOW TO WARRANT A NEW ADVISORY AT HIGHER ELEVATION SPOTS
LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY BE HAZARDOUS OVER THE
PASS.
AN UPPER RIDGE OFFSHORE WILL BEGIN TO BUILD INTO THE AREA TONIGHT.
PARTIAL CLEARING IN THE EVENING WEST OF THE CASCADES WILL ALLOW
AREAS OF LOW CLOUDS AND FOG TO DEVELOP IN THE VALLEYS. TUESDAY
WILL BE A DRY DAY FOR MOST AREAS, THOUGH THERE MAY BE SOME LIGHT
RAIN OVER THE COASTAL WATERS AND NEAR REEDSPORT AND FLORENCE.
THE NEXT SIGNIFICANT WEATHER SYSTEM WILL APPROACH THE AREA
WEDNESDAY SENDING A WET WARM FRONT THROUGH THE AREA WEDNESDAY
NIGHT. THE 00Z GFS20 BRINGS PRECIPITATION ONSHORE WEDNESDAY
AFTERNOON AND IS ABOUT 6 HOURS FASTER THAN 00Z ECMWF. EITHER WAY,
SIGNIFICANT RAINFALL IS EXPECTED ACROSS MOST OF THE AREA WITH THE
FRONT WEDNESDAY NIGHT. SNOW LEVELS WILL BE A BIT HIGHER WITH THIS
SYSTEM STARTING NEAR 3500 FEET WEDNESDAY EVENING, THEN SURGING TO
AROUND 7000-7500 FEET BY THURSDAY EVENING. SNOW IMPACTS SHOULD BE
RESERVED FOR THE HIGHEST ELEVATIONS. SIMILAR TO THE MOST RECENT
STORM, THE WARM FRONT WILL BE FOLLOWED BY ANOTHER WET COLD FRONT
THAT WILL PUSH VERY SLOWLY THROUGH THE AREA THURSDAY THROUGH
FRIDAY NIGHT, BRINGING A RENEWED THREAT OF SIGNIFICANT RAINFALL ON
ALREADY SATURATED SOILS. SINCE RIVERS, CREEKS AND STREAMS WILL
STILL BE RUNNING RELATIVELY HIGH AND LOWER ELEVATION SNOW WILL
LIKELY MELT, WE EXPECT HYDROLOGY ISSUES ONCE AGAIN. THE UPPER
TROUGH WITH THIS SYSTEM WILL LIKELY SPLIT AS IT MOVES OVER THE
AREA SATURDAY AND PRECIPITATION WILL GRADUALLY TAPER OFF SOUTH AND
EAST OF THE CASCADES AND END SATURDAY NIGHT. THERE WON`T BE MUCH
OF A BREAK THOUGH...SINCE THE NEXT SYSTEM IS EXPECTED TO MOVE IN
SUNDAY. SPILDE
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ024.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1500
FEET FOR FOR ORZ026.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS EVENING
TO 10 AM PST TUESDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR
PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
859 AM PST MON DEC 14 2015
.SYNOPSIS...SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS PERSIST AS A
COOL UPPER LEVEL TROUGH MOVES THROUGH THE PAC NW TODAY. WEAK LOW
PRESSURE OFF THE WA COAST WILL DROP SOUTHEAST TODAY...BRINGING A
BATCH OF STEADIER PRECIPITATION TO THE OREGON COAST AND COAST RANGE.
SNOW LEVELS WILL BE 1500-2000 FEET IN THE COAST RANGE AS THIS OCCURS
FOR SOME ACCUMULATING SNOW THIS MORNING. HIGH PRESSURE WILL TAKE OVER
TONIGHT...AND CLEARING SKIES COULD LEAD TO SOME VALLEY FOG AND A
LITTLE BLACK ICE IN THE COLDER SPOTS TONIGHT AND TUE MORNING. HIGH
PRESSURE SHOULD KEEP TUESDAY MOSTLY DRY...THEN RAIN CHANCES INCREASE
AGAIN TUESDAY NIGHT AND WEDNESDAY AS WEAK FRONT CLIPS THROUGH
WASHINGTON AND NORTHERN OREGON. THE NEXT STRONG FRONTAL SYSTEM WILL
LIKELY BRING HEAVIER RAIN BACK TO THE REGION LATER WEDNESDAY THROUGH
THURSDAY...WITH SNOW IN THE CASCADES. ENOUGH COLD AIR MAY LINGER FOR
WINTRY PRECIPITATION IN THE HOOD RIVER VALLEY WITH THIS SYSTEM. COOL
AND UNSETTLED WEATHER IS EXPECTED TO FOLLOW INTO THE WEEKEND...WITH
ADDITIONAL SNOW POSSIBLE FOR THE CASCADES.
&&
.UPDATE...RADAR SHOWS A BATCH OF SHOWERS MOVING THROUGH THE COAST
RANGE AND ACROSS THE VALLEY. FROM OBSERVATIONS IN THE COAST RANGE
THE SNOW LEVEL MAY BE DOWN TO 1500 FEET BUT MAY BE MORE OF A MIX OF
RAIN AND SNOW. 2000 FEET AND ABOVE APPEARS WHERE SNOW ACCUMULATION
IS OCCURRING. SNOW ADVISORY FOR THE COAST RANGE LOOKS GOOD AND WILL
KEEP IT GOING...BUT IT MAY BE EXPIRED SOONER THAN THE CURRENT TIMING
DEPENDING ON THE SPEED OF THE SYSTEM. THIS BATCH OF SHOWERS WILL
MOVE SOUTH AND EAST AND WEAKEN TODAY. MAY EVEN SEE SOME SUNSHINE
FOR THE FAR NORTHERN ZONES LATER TODAY.
&&
.PREV DISCUSSION... /ISSUED 306 AM PST MON DEC 14 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY...UNSETTLED WEATHER CONTINUES
THIS MORNING WITH SCATTERED SHOWERS ACROSS SW WASHINGTON AND NW
OREGON...MAINLY DUE TO AN UPPER TROUGH MOVING THROUGH THE PAC NW.
SOME STEADIER ECHOES ARE STARTING TO SHOW UP ON KLGX NWS DOPPLER
RADAR...ASSOCIATED WITH WEAK LOW PRESSURE OFF THE WA COAST. AS THE
LOW MOVES S-SE...EXPECT STEADIER PRECIP TO MOVE ONSHORE SOUTH OF
ABOUT TILLAMOOK THIS MORNING. PAST FEW HRRR RUNS HAVE SHOWN A SWATH
OF MODERATE PRECIP MOVING INTO THE CENTRAL COAST AND COAST RANGE OF
OREGON AROUND 7 AM...CONTINUING UNTIL ABOUT NOON AS A 1019 MB LOW
MOVES THROUGH THE AREA. OTHERWISE...SHALLOW INSTABILITY WILL PROBABLY
KEEP SCATTERED SHOWERS AROUND WELL INTO THE DAY. HIGHER PRESSURE BOTH
AT THE SURFACE AND ALOFT WILL LIKELY CAUSE SUBSIDENCE AND DRYING
LATER THIS AFTERNOON AND EVENING...WITH WARMER AIR ALOFT INCREASINGLY
CAPPING ANY SHALLOW CONVECTION AND BRINGING SHOWER ACTIVITY TO AN
END.
SKIES MAY CLEAR A BIT TONIGHT AS HIGH PRESSURE BUILDS IN AND
NORTHERLY FLOW DEVELOPS. THE NORTHERLY FLOW SHOULD KEEP THE BOUNDARY
LAYER BARELY MIXED ENOUGH TO PREVENT WIDESPREAD FOG...BUT SOME
PATCHES WILL PROBABLY DEVELOP IN THE MORE FOG-PRONE SHELTERED VALLEYS
DUE TO THE VERY WET GROUND. MOS TEMPS ARE BELOW FREEZING TONIGHT IN
THE COOLER VALLEY SPOTS...SO THERE MAY BE SOME BLACK ICE TONIGHT/
EARLY TUE MORNING WHERE ROADS REMAIN WET FROM ALL THE RECENT
RAIN WE HAVE HAD.
SUNDAY DECEMBER 13 WAS THE 13TH DAY IN A ROW WITH MORE THAN A QUARTER
INCH OF RAIN AT KPDX...BREAKING THE PREVIOUS RECORD OF 11 DAYS SET
JANUARY 16-26 1970. THERE IS A DECENT CHANCE THAT TODAY WILL BREAK
THAT STREAK. IF NOT TODAY...TUESDAY SHOULD BREAK THE STREAK AND MAY
ACTUALLY BE TOTALLY DRY FOR MUCH OF THE FORECAST AREA AS HIGH
PRESSURE BRIEFLY BUILDS INTO THE PAC NW. THIS IS BY NO MEANS A
CERTAINTY...AS A WEAK COLD FRONT IS FCST TO CLIP WA/N OR TUE NIGHT
INTO WED AND MAY BRING SOME SHOWERS BACK TO OUR NORTHERN ZONES.
THE TUE NIGHT/EARLY WED COLD FRONT IS FAIRLY IMPORTANT...AS IT MAY
RECHARGE THE COLD AIR EAST OF THE CASCADES AND SET UP A WEAK
BAROCLINIC ZONE OVER NORTHWEST OF WEST-CENTRAL OREGON. IF THIS COLD
AIR GETS INTO THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY...IT
MAY END UP STUCK THERE AS A MUCH STRONGER AND WETTER SYSTEM ARRIVES
WED NIGHT/THU. THE BAROCLINIC ZONE WOULD ALSO PROVIDE AN OVERRUNNING
SURFACE FOR THE MOIST AND RELATIVELY WARM ATMOSPHERIC RIVER ARRIVES
LATE WED. THE RESULTING ISENTROPIC LIFT COULD YIELD ANOTHER ROUND OF
HEAVY RAIN FOR MUCH OF THE FORECAST AREA LATE WED INTO THU. PREFER
THE 00Z GFS SOLUTION...AS THE RELATIVELY DRIER/SLOWER 12Z/00Z ECMWF
HAS BEEN A BIT OF AN OUTLIER AMONGST ITS OWN ENSEMBLE MEMBERS. IF THE
GFS QPF VERIFIES...THERE MAY BE ANOTHER ROUND OF HYDROLOGIC PROBLEMS
ACROSS MUCH OF OUR FORECAST AREA WED NIGHT/THU...IN ADDITION TO HEAVY
SNOW AND/OR ICE IN THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY.
WHILE CONFIDENCE IS INCREASING THAT THIS WEEK WILL BE ANOTHER ACTIVE
ONE WITH A VARIETY OF WEATHER CONCERNS...DETAILS MAY STILL CHANGE AS
FUTURE MODEL RUNS COME IN. STAY TUNED.WEAGLE
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE IS GROWING
THAT YET ANOTHER ATMOSPHERIC RIVER EVENT WILL HAMMER THE PAC NW WITH
HEAVY RAIN WED NIGHT AND THURSDAY...POSSIBLY LINGERING INTO FRIDAY.
THIS IS NOT AN OPPORTUNE TIME FOR THIS TO OCCUR AS RIVERS WILL STILL
BE HIGH AND THE GROUND SATURATED FROM LAST WEEK. THE 00Z 4 KM UW
WRF-GFS ALREADY HAS 2-5 INCHES OF QPF FROM THIS SYSTEM IN THE HIGHER
TERRAIN BY THE END OF THE RUN AT 12Z THU...WITH ABOUT AN INCH IN THE
LOWLANDS. THE 12Z/00Z ECMWF HAVE BEEN NOTABLY SLOWER/DRIER THAN THE
U.S. MODELS...BUT AT LEAST THE 00Z ECMWF IS SOMEWHAT OF AN OUTLIER
AMONGST ITS ENSEMBLE MEMBERS WITH MOST ENSEMBLES BRINGING RAIN IN
AROUND THE SAME TIME AS THE 00Z GFS. THE 06Z GFS DOES NOT TAKE ITS
FOOT OFF THE ACCELERATOR...REMAINING CONSISTENT WITH PREVIOUS RUNS.
AFTER COORDINATION WITH WPC AND OUR SURROUNDING OFFICES...DECIDED TO
DISREGARD THE DRIER ECMWF RUNS AND OUR FORECAST BRINGS IN SIGNIFICANT
QPF BY WED NIGHT. WILL HOLD OFF ON ISSUING A HYDROLOGIC STATEMENT FOR
NOW...BUT IF THE 12Z ECMWF COMES IN LINE WITH THE WETTER U.S. MODELS
FUTURE SHIFTS MAY WANT TO DO SO. IF THE 00Z GFS IS TO BE BELIEVED...
THE HIGHER TERRAIN MAY SEE ANOTHER 5-10 INCHES OF RAIN LATE WED-
FRI...WITH ANOTHER 2-4 INCHES IN THE INTERIOR LOWLANDS INCLUDING THE
HOOD RIVER VALLEY.
WITH COLD AIR POSSIBLY TRAPPED IN THE HOOD RIVER VALLEY AND EASTERN
SKAMANIA COUNTY...THERE IS THE POTENTIAL FOR HEAVY SNOW OR ICE AT
LEAST IN THE HIGHER PORTIONS OF THOSE VALLEYS. WHILE SNOW LEVELS
WILL BE RISING IN GENERAL...THEY MAY BE MORE STUBBORN NORTH OF
SANTIAM PASS. THIS COULD LEAD TO A DECENT AMOUNT OF SNOW FOR MOUNTS
HOOD AND ADAMS...WHILE MOUNT ST. HELENS AND THE LANE COUNTY CASCADES
SEE MAINLY RAIN OR MIXED RAIN/SNOW. STILL TOO EARLY TO SORT OUT THESE
DETAILS PRECISELY AND MUCH MAY CHANGE BETWEEN NOW AND THURSDAY.
THE BAROCLINIC ZONE WILL LIKELY SHIFT SOUTHWARD FRIDAY...PUSHING THE
HEAVIEST RAIN SOUTH TOWARD THE OR/CA BORDER. MODELS SHOW DECENT
AGREEMENT THAT ANOTHER COOL UPPER TROUGH WILL MOVE ACROSS THE PAC NW
BEHIND THIS...FOR MORE SHOWERS FRI/SAT. THE NEXT FRONT MAY ARRIVE AS
EARLY AS SAT NIGHT/SUN FOR MORE RAIN AND MOUNTAIN SNOW. BOTTOM LINE
IS...THERE IS NO END IN SIGHT TO OUR VERY ACTIVE DECEMBER WEATHER...
AT LEAST NOT FOR THE NEXT 7-10 DAYS. WEAGLE
&&
.AVIATION...A SHOWERY UNSTABLE AIRMASS WILL LEAD TO PRIMARILY VFR
CONDITIONS TODAY WITH OCCASIONAL MVFR CONDITIONS BETWEEN 17Z AND
21Z MONDAY. THE PRIMARY EXCEPTION TO THIS WILL LIKELY BE AT KONP
AND POSSIBLY KEUG WHERE WEAK WARM FRONTAL LIFT MAY PRODUCE A MORE
EXTENDED PERIOD OF MVFR AND HIGH END IFR CONDITIONS. THE EXTENT OF
CLEARING THIS EVENING REMAINS SOMEWHAT UNCERTAIN...BUT CURRENT
THINKING IS THAT THERE SHOULD BE ENOUGH THAT MOST LOCATIONS SHOULD
DETERIORATE SOLIDLY INTO A MIX OF AT LEAST MVFR AND IFR
CONDITIONS BETWEEN 06Z AND 18Z TUESDAY. THERE IS GOOD CHANCE LIFR
CONDITIONS WILL IMPACT MOST TERMINALS DURING THIS TIME.
KPDX AND APPROACHES...A SHOWERY UNSTABLE AIRMASS WILL LEAD TO
PRIMARILY VFR CONDITIONS WITH OCCASIONAL MVFR CONDITIONS BETWEEN
17Z AND 21Z MONDAY. A STABILIZING LOWER ATMOSPHERE SHOULD RESULT
IN MVFR/IFR FLIGHT RESTRICTIONS DEVELOPING TOWARDS 06Z TUESDAY AND
CONTINUING THROUGH 18Z TUESDAY. THERE APPEARS TO BE A GOOD CHANCE
LIFR CONDITIONS WILL DEVELOP DURING THIS PERIOD. /NEUMAN
&&
.MARINE...A WEAK LOW PRESSURE WILL MOVE SOUTHWARD NEAR THE COAST
TODAY...REINFORCING GUSTY NORTHWEST WINDS OF 20 TO 30 KT ACROSS
THE WATERS. THESE WINDS SHOULD GRADUALLY SUBSIDE THIS EVENING AS
PRESSURE GRADIENTS RELAX. WITH NO MAJOR STORM SYSTEMS IN THE
EASTERN PACIFIC...THE LARGE SEAS CURRENTLY FOUND IN THE WATERS
WILL ALSO SUBSIDE DURING THIS TIME...LIKELY FALLING INTO THE LOW
TEENS BY THIS EVENING AND BELOW 10 FT BY TUESDAY MORNING.
THE NEXT STORM SYSTEM...IN THE FORM OF A WARM FRONT...WILL SPREAD
INTO THE WATERS ON WEDNESDAY NIGHT...WHICH SHOULD RESULT IN HIGH
END SMALL CRAFT TO LOW END GALE FORCE WIND GUSTS OF 30 TO 35 KT
SPREADING INTO THE WATERS. A LOW PRESSURE MAY POSSIBLY DEVELOPING
ALONG THE TRAILING COLD FRONT...WHICH COULD RESULT IN HIGHER WINDS
AND SEAS TOWARDS THURSDAY...BUT CONFIDENCE IN DETAILS REMAINS LOW
GIVEN MODELS CONTINUE IN THEIR DEPICTION OF THIS STORM SYSTEM. A
WEAK FRONT OR TWO MAY MOVE INTO THE WATERS FRIDAY/SATURDAY TIME
FRAME...BEFORE ANOTHER STRONGER FRONTAL STORM SYSTEM POSSIBLY
MOVES INTO THE WATERS LATE SATURDAY/SUNDAY. /NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 11 AM PST THIS MORNING FOR COAST
RANGE OF NORTHWEST OREGON.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COAST RANGE OF WESTERN OREGON.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PST TUESDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM
PST TUESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
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 MEDFORD OR
402 AM PST MON DEC 14 2015
.DISCUSSION...IN THE WAKE OF YESTERDAY`S STORM...WE ARE NOW IN
A COLD NORTH TO NORTHWEST FLOW ALOFT. THERE ARE STILL A COUPLE OF
DISTURBANCES THAT WILL MOVE THROUGH ON THE BACK SIDE OF AN UPPER
LEVEL TROUGH, THE AXIS OF WHICH IS CENTERED OVER IDAHO AND NEVADA
EARLY THIS MORNING.
THE FIRST DISTURBANCE IS MOVING THROUGH NOW WITH NUMEROUS SHOWERS
OCCURRING FROM THE CASCADES AND SISKIYOUS NORTH AND WEST. SNOW
LEVELS ARE RUNNING ABOUT 1500 TO 2000 FEET...THOUGH THEY COULD BE
LOCALLY DOWN AS LOW AS 1000 FEET IN HEAVIER SHOWERS. SOME SHOWERS
MAY ALSO MAKE IT SOUTH AND EAST OF THE MOUNTAINS, BUT THESE WILL
BE SCATTERED AT BEST. A WINTER WEATHER ADVISORY AT WSWMFR REMAINS
IN EFFECT THIS MORNING OVER THE WEST SIDE. THE BEST CHANCE FOR AN
INCH OR TWO OF NEW SNOW WILL BE ON THE NORTH AND WEST FACING
SLOPES OF JACKSON AND JOSEPHINE COUNTIES AS WELL AS THE UMPQUA
DIVIDE, MAINLY ABOVE 1500 FEET. THE MAIN PASSES ON INTERSTATE 5 IN
OREGON COULD BE IMPACTED BY THESE HEAVIER SNOW SHOWERS.
THE LATEST HRRR IS SHOWING ANOTHER DISTURBANCE MOVING IN THIS
AFTERNOON, WHICH WILL KEEP SHOWERS GOING INTO THE EVENING HOURS,
BUT SNOW LEVELS SHOULD RISE TO NEAR 2000 FEET WEST OF THE CASCADES
AND ROAD SURFACE TEMPERATURES SHOULD WARM ENOUGH TO PRECLUDE
SIGNIFICANT SNOW IMPACTS AT THE LOWER ELEVATIONS. THERE WON`T BE
ENOUGH SNOW TO WARRANT A NEW ADVISORY AT HIGHER ELEVATION SPOTS
LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY BE HAZARDOUS OVER THE
PASS.
AN UPPER RIDGE OFFSHORE WILL BEGIN TO BUILD INTO THE AREA TONIGHT.
PARTIAL CLEARING IN THE EVENING WEST OF THE CASCADES WILL ALLOW
AREAS OF LOW CLOUDS AND FOG TO DEVELOP IN THE VALLEYS. TUESDAY
WILL BE A DRY DAY FOR MOST AREAS, THOUGH THERE MAY BE SOME LIGHT
RAIN OVER THE COASTAL WATERS AND NEAR REEDSPORT AND FLORENCE.
THE NEXT SIGNIFICANT WEATHER SYSTEM WILL APPROACH THE AREA
WEDNESDAY SENDING A WET WARM FRONT THROUGH THE AREA WEDNESDAY
NIGHT. THE 00Z GFS20 BRINGS PRECIPITATION ONSHORE WEDNESDAY
AFTERNOON AND IS ABOUT 6 HOURS FASTER THAN 00Z ECMWF. EITHER WAY,
SIGNIFICANT RAINFALL IS EXPECTED ACROSS MOST OF THE AREA WITH THE
FRONT WEDNESDAY NIGHT. SNOW LEVELS WILL BE A BIT HIGHER WITH THIS
SYSTEM STARTING NEAR 3500 FEET WEDNESDAY EVENING, THEN SURGING TO
AROUND 7000-7500 FEET BY THURSDAY EVENING. SNOW IMPACTS SHOULD BE
RESERVED FOR THE HIGHEST ELEVATIONS. SIMILAR TO THE MOST RECENT
STORM, THE WARM FRONT WILL BE FOLLOWED BY ANOTHER WET COLD FRONT
THAT WILL PUSH VERY SLOWLY THROUGH THE AREA THURSDAY THROUGH
FRIDAY NIGHT, BRINGING A RENEWED THREAT OF SIGNIFICANT RAINFALL ON
ALREADY SATURATED SOILS. SINCE RIVERS, CREEKS AND STREAMS WILL
STILL BE RUNNING RELATIVELY HIGH AND LOWER ELEVATION SNOW WILL
LIKELY MELT, WE EXPECT HYDROLOGY ISSUES ONCE AGAIN. THE UPPER
TROUGH WITH THIS SYSTEM WILL LIKELY SPLIT AS IT MOVES OVER THE
AREA SATURDAY AND PRECIPITATION WILL GRADUALLY TAPER OFF SOUTH AND
EAST OF THE CASCADES AND END SATURDAY NIGHT. THERE WON`T BE MUCH
OF A BREAK THOUGH...SINCE THE NEXT SYSTEM IS EXPECTED TO MOVE IN
SUNDAY. SPILDE
&&
.AVIATION...FOR THE 14/12Z TAF CYCLE...NUMEROUS TO WIDESPREAD RAIN
AND SNOW SHOWERS FROM THE CASCADES WESTWARD ARE EXPECTED THROUGH
THIS AFTERNOON...THEN SHOWERS WILL BECOME SCATTERED DURING THE
EVENING. FROM THE CASCADES WEST...THIS WILL CREATE A MIX OF IFR AND
MVFR CIGS WITH PERIODS OF MOUNTAIN OBSCURATIONS THROUGH THIS
EVENING. EAST OF THE CASCADES...CONDITIONS WILL BE MAINLY VFR WITH
ISOLATED SNOW SHOWERS AND MVFR CEILINGS. SHOWERS WILL TAPER OFF
OVERNIGHT WITH VFR CONDITIONS DEVELOPING EXCEPT FOR IFR/MVFR VALLEY
LOW CLOUDS AND FOG FORMING WEST OF THE CASCADES AND POSSIBLY IN THE
KLAMATH BASIN. /CC
&&
.MARINE...UPDATED 300 AM PST MONDAY 14 DEC 2015....GUSTY NORTHWEST
WINDS MAY BRIEFLY LOWER LATE THIS MORNING THEN INCREASE AGAIN THIS
AFTERNOON THROUGH THIS EVENING. VERY STEEP SEAS WILL CONTINUE TODAY
INTO THIS EVENING. SEAS WILL GRADUALLY LOWER BUT WILL REMAIN STEEP
THROUGH TUESDAY MORNING. HIGH AND VERY LONG PERIOD SWELL IS EXPECTED
TO MOVE INTO THE WATERS WEDNESDAY MORNING. A COUPLE FRONTS WILL MOVE
INTO THE AREA WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THIS IS
EXPECTED TO BRING PERIODS OF STRONG GUSTY SOUTH WINDS AS WELL AS
STEEP TO VERY STEEP SEAS. GALES ARE POSSIBLE WITH THE FRONT ON
THURSDAY NIGHT. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ024.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1500
FEET FOR FOR ORZ026.
WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING FOR
ORZ027-028.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING ABOVE
2000 FEET FOR FOR CAZ080.
WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING FOR
CAZ081.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM
10 PM THIS EVENING TO 10 AM PST TUESDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR
PZZ350-356-370-376.
$$
MAS/CC/DW
AREA FORECAST DISCUSSION
NWS PORTLAND OR
306 AM PST MON DEC 14 2015
.SYNOPSIS...SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS PERSIST AS A
COOL UPPER LEVEL TROUGH MOVES THROUGH THE PAC NW. WEAK LOW PRESSURE
OFF THE WA COAST WILL DROP SOUTHEAST TODAY...BRINGING A BATCH OF
STEADIER PRECIPITATION TO THE OREGON COAST AND COAST RANGE. SNOW
LEVELS WILL BE 1500-2000 FEET IN THE COAST RANGE AS THIS OCCURS...SO
SOME ACCUMULATING SNOW IS LIKELY THIS MORNING IN THE HIGHER
ELEVATIONS OF POLK/LINCOLN COUNTIES SOUTHWARD. HIGH PRESSURE WILL
TAKE OVER TONIGHT...AND CLEARING SKIES COULD LEAD TO SOME VALLEY FOG
AND A LITTLE BLACK ICE IN THE COLDER SPOTS TONIGHT AND TUE MORNING.
HIGH PRESSURE SHOULD KEEP TUESDAY MOSTLY DRY...THEN RAIN CHANCES
INCREASE AGAIN TUESDAY NIGHT AND WEDNESDAY AS WEAK FRONT CLIPS
THROUGH WASHINGTON AND NORTHERN OREGON. THE NEXT STRONG FRONTAL
SYSTEM WILL LIKELY BRING HEAVIER RAIN BACK TO THE REGION LATER
WEDNESDAY THROUGH THURSDAY...WITH SNOW IN THE CASCADES. ENOUGH COLD
AIR MAY LINGER FOR WINTRY PRECIPITATION IN THE HOOD RIVER VALLEY WITH
THIS SYSTEM. COOL AND UNSETTLED WEATHER IS EXPECTED TO FOLLOW INTO
THE WEEKEND...WITH ADDITIONAL SNOW POSSIBLE FOR THE CASCADES.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...UNSETTLED WEATHER CONTINUES
THIS MORNING WITH SCATTERED SHOWERS ACROSS SW WASHINGTON AND NW
OREGON...MAINLY DUE TO AN UPPER TROUGH MOVING THROUGH THE PAC NW.
SOME STEADIER ECHOES ARE STARTING TO SHOW UP ON KLGX NWS DOPPLER
RADAR...ASSOCIATED WITH WEAK LOW PRESSURE OFF THE WA COAST. AS THE
LOW MOVES S-SE...EXPECT STEADIER PRECIP TO MOVE ONSHORE SOUTH OF
ABOUT TILLAMOOK THIS MORNING. PAST FEW HRRR RUNS HAVE SHOWN A SWATH
OF MODERATE PRECIP MOVING INTO THE CENTRAL COAST AND COAST RANGE OF
OREGON AROUND 7 AM...CONTINUING UNTIL ABOUT NOON AS A 1019 MB LOW
MOVES THROUGH THE AREA. OTHERWISE...SHALLOW INSTABILITY WILL PROBABLY
KEEP SCATTERED SHOWERS AROUND WELL INTO THE DAY. HIGHER PRESSURE BOTH
AT THE SURFACE AND ALOFT WILL LIKELY CAUSE SUBSIDENCE AND DRYING
LATER THIS AFTERNOON AND EVENING...WITH WARMER AIR ALOFT INCREASINGLY
CAPPING ANY SHALLOW CONVECTION AND BRINGING SHOWER ACTIVITY TO AN
END.
SKIES MAY CLEAR A BIT TONIGHT AS HIGH PRESSURE BUILDS IN AND
NORTHERLY FLOW DEVELOPS. THE NORTHERLY FLOW SHOULD KEEP THE BOUNDARY
LAYER BARELY MIXED ENOUGH TO PREVENT WIDESPREAD FOG...BUT SOME
PATCHES WILL PROBABLY DEVELOP IN THE MORE FOG-PRONE SHELTERED VALLEYS
DUE TO THE VERY WET GROUND. MOS TEMPS ARE BELOW FREEZING TONIGHT IN
THE COOLER VALLEY SPOTS...SO THERE MAY BE SOME BLACK ICE TONIGHT/
EARLY TUE MORNING WHERE ROADS REMAIN WET FROM ALL THE RECENT
RAIN WE HAVE HAD.
SUNDAY DECEMBER 13 WAS THE 13TH DAY IN A ROW WITH MORE THAN A QUARTER
INCH OF RAIN AT KPDX...BREAKING THE PREVIOUS RECORD OF 11 DAYS SET
JANUARY 16-26 1970. THERE IS A DECENT CHANCE THAT TODAY WILL BREAK
THAT STREAK. IF NOT TODAY...TUESDAY SHOULD BREAK THE STREAK AND MAY
ACTUALLY BE TOTALLY DRY FOR MUCH OF THE FORECAST AREA AS HIGH
PRESSURE BRIEFLY BUILDS INTO THE PAC NW. THIS IS BY NO MEANS A
CERTAINTY...AS A WEAK COLD FRONT IS FCST TO CLIP WA/N OR TUE NIGHT
INTO WED AND MAY BRING SOME SHOWERS BACK TO OUR NORTHERN ZONES.
THE TUE NIGHT/EARLY WED COLD FRONT IS FAIRLY IMPORTANT...AS IT MAY
RECHARGE THE COLD AIR EAST OF THE CASCADES AND SET UP A WEAK
BAROCLINIC ZONE OVER NORTHWEST OF WEST-CENTRAL OREGON. IF THIS COLD
AIR GETS INTO THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY...IT
MAY END UP STUCK THERE AS A MUCH STRONGER AND WETTER SYSTEM ARRIVES
WED NIGHT/THU. THE BAROCLINIC ZONE WOULD ALSO PROVIDE AN OVERRUNNING
SURFACE FOR THE MOIST AND RELATIVELY WARM ATMOSPHERIC RIVER ARRIVES
LATE WED. THE RESULTING ISENTROPIC LIFT COULD YIELD ANOTHER ROUND OF
HEAVY RAIN FOR MUCH OF THE FORECAST AREA LATE WED INTO THU. PREFER
THE 00Z GFS SOLUTION...AS THE RELATIVELY DRIER/SLOWER 12Z/00Z ECMWF
HAS BEEN A BIT OF AN OUTLIER AMONGST ITS OWN ENSEMBLE MEMBERS. IF THE
GFS QPF VERIFIES...THERE MAY BE ANOTHER ROUND OF HYDROLOGIC PROBLEMS
ACROSS MUCH OF OUR FORECAST AREA WED NIGHT/THU...IN ADDITION TO HEAVY
SNOW AND/OR ICE IN THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY.
WHILE CONFIDENCE IS INCREASING THAT THIS WEEK WILL BE ANOTHER ACTIVE
ONE WITH A VARIETY OF WEATHER CONCERNS...DETAILS MAY STILL CHANGE AS
FUTURE MODEL RUNS COME IN. STAY TUNED.WEAGLE
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE IS GROWING
THAT YET ANOTHER ATMOSPHERIC RIVER EVENT WILL HAMMER THE PAC NW WITH
HEAVY RAIN WED NIGHT AND THURSDAY...POSSIBLY LINGERING INTO FRIDAY.
THIS IS NOT AN OPPORTUNE TIME FOR THIS TO OCCUR AS RIVERS WILL STILL
BE HIGH AND THE GROUND SATURATED FROM LAST WEEK. THE 00Z 4 KM UW
WRF-GFS ALREADY HAS 2-5 INCHES OF QPF FROM THIS SYSTEM IN THE HIGHER
TERRAIN BY THE END OF THE RUN AT 12Z THU...WITH ABOUT AN INCH IN THE
LOWLANDS. THE 12Z/00Z ECMWF HAVE BEEN NOTABLY SLOWER/DRIER THAN THE
U.S. MODELS...BUT AT LEAST THE 00Z ECMWF IS SOMEWHAT OF AN OUTLIER
AMONGST ITS ENSEMBLE MEMBERS WITH MOST ENSEMBLES BRINGING RAIN IN
AROUND THE SAME TIME AS THE 00Z GFS. THE 06Z GFS DOES NOT TAKE ITS
FOOT OFF THE ACCELERATOR...REMAINING CONSISTENT WITH PREVIOUS RUNS.
AFTER COORDINATION WITH WPC AND OUR SURROUNDING OFFICES...DECIDED TO
DISREGARD THE DRIER ECMWF RUNS AND OUR FORECAST BRINGS IN SIGNIFICANT
QPF BY WED NIGHT. WILL HOLD OFF ON ISSUING A HYDROLOGIC STATEMENT FOR
NOW...BUT IF THE 12Z ECMWF COMES IN LINE WITH THE WETTER U.S. MODELS
FUTURE SHIFTS MAY WANT TO DO SO. IF THE 00Z GFS IS TO BE BELIEVED...
THE HIGHER TERRAIN MAY SEE ANOTHER 5-10 INCHES OF RAIN LATE WED-
FRI...WITH ANOTHER 2-4 INCHES IN THE INTERIOR LOWLANDS INCLUDING THE
HOOD RIVER VALLEY.
WITH COLD AIR POSSIBLY TRAPPED IN THE HOOD RIVER VALLEY AND EASTERN
SKAMANIA COUNTY...THERE IS THE POTENTIAL FOR HEAVY SNOW OR ICE AT
LEAST IN THE HIGHER PORTIONS OF THOSE VALLEYS. WHILE SNOW LEVELS
WILL BE RISING IN GENERAL...THEY MAY BE MORE STUBBORN NORTH OF
SANTIAM PASS. THIS COULD LEAD TO A DECENT AMOUNT OF SNOW FOR MOUNTS
HOOD AND ADAMS...WHILE MOUNT ST. HELENS AND THE LANE COUNTY CASCADES
SEE MAINLY RAIN OR MIXED RAIN/SNOW. STILL TOO EARLY TO SORT OUT THESE
DETAILS PRECISELY AND MUCH MAY CHANGE BETWEEN NOW AND THURSDAY.
THE BAROCLINIC ZONE WILL LIKELY SHIFT SOUTHWARD FRIDAY...PUSHING THE
HEAVIEST RAIN SOUTH TOWARD THE OR/CA BORDER. MODELS SHOW DECENT
AGREEMENT THAT ANOTHER COOL UPPER TROUGH WILL MOVE ACROSS THE PAC NW
BEHIND THIS...FOR MORE SHOWERS FRI/SAT. THE NEXT FRONT MAY ARRIVE AS
EARLY AS SAT NIGHT/SUN FOR MORE RAIN AND MOUNTAIN SNOW. BOTTOM LINE
IS...THERE IS NO END IN SIGHT TO OUR VERY ACTIVE DECEMBER WEATHER...
AT LEAST NOT FOR THE NEXT 7-10 DAYS. WEAGLE
&&
.AVIATION...VFR ACROSS REGION THIS AM...WITH POCKETS OF MVFR
CONDITIONS UNDER THE SCATTERED SHOWERS. WILL SEE MVFR CIGS
INCREASE FROM NW TO SE ACROSS REGION AFTER 12Z AS WEAK LOW PRES
ARRIVES FROM THE NW. THE WEAK LOW WILL ALSO INCREASE SHOWERS. MAY
HAVE PERIODS OF IFR ALONG THE COAST...BUT STILL THINK THIS WOULD
BE PATCHY IN NATURE TO S OF KAST. CONDITIONS WILL GRADUALLY
IMPROVE BACK TO LOW VFR AFTER 03Z AS SYSTEMS MOVES ON INTO SW
OREGON AND WEAK HIGH PRES BUILDS OVER NW OREGON.
KPDX AND APPROACHES...SHOWERS INCREASING AFTER 16Z. PREDOMINATELY
VFR CONDITIONS TODAY INTO THIS EVENING...BUT WILL SEE CIGS FLIRT
WITH HIGH END MVFR AT TIMES BETWEEN 17Z AND 23Z.
&&
.MARINE...GUSTY NW WINDS ARE PERSISTING THIS AM...MAINLY DUE TO
TIGHTER GRADIENT ON THE S AND SW SIDE OF THE LOW PRES THAT IS
APPROACHING FROM THE NW. AS THE LOW DROPS INTO THE REGION LATER
THIS AM...THE WINDS WILL EASE BACK TO 20 KT OR LESS. BUT THIS NOT
LIKELY UNTIL 5 OR 6 AM. SO WILL MAINTAIN GALE WARNING ON ALL
WATERS THROUGH 6 AM TODAY.
SEAS ALSO SLOW TO SUBSIDE. GENERALLY RUNNING AT 20 TO 23 FT...
THOUGH HAVE SEEN SEAS S OF CASCADE HEAD STARTING TO LOWER BACK A
TAD. THESE WAVES MORE DEPENDENT ON THE WINDS...SO AS THE WINDS
EASE THIS AM...SO WILL THE SEAS. STILL LOOKS AS THOUGH SEAS WILL
DROP BACK UNDER 20 FT BY 8 AM... WITH SEAS SUBSIDING BACK TO 14 TO
16 FT BY AFTERNOON.
BREAK IN THE WEATHER FOR LATER TONIGHT THROUGH TUE NIGHT...WITH
WINDS 15 KT OR LESS AND SEAS AROUND 10 FT. BUT...ANOTHER SYSTEM
WILL APPROACH FROM THE W WED. THIS WILL BRING WINDS BACK ABOVE 25
KT...WITH SEAS BUILDING BACK INTO THE 12 TO 15 FT RANGE. MORE
FRONT WILL ARRIVE LATER THIS WEEK...WITH CONTINUED GUSTY WINDS AND
HIGHER SEAS AT TIMES.ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH SURF ADVISORY UNTIL 8 AM TODAY FOR COAST OF NORTH AND
WEST CENTRAL OREGON.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM PST THIS
AFTERNOON FOR CENTRAL COAST RANGE OF WESTERN OREGON.
WA...HIGH SURF ADVISORY UNTIL 8 AM TODAY FOR S WASHINGTON COAST.
PZ...GALE WARNING UNTIL 6 AM TODAY ON ALL COASTAL WATERS.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS TODAY
AND THIS EVENING.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
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 STATE COLLEGE PA
1036 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION LATE TODAY.
TEMPERATURES WILL BE WARM AGAIN TODAY...COOLING A BIT FOR MIDWEEK.
ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. SEASONAL TEMPERATURES ARE IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
SHOWERS ALMOST TO KCLE AND KZZV. COLD FRONT IS ON THE OH/IN
BORDER. ARRIVAL TIME PER LATEST HRRR/RAP/NAM/GFS ENSEMBLE IS
SPOT ON AROUND 19Z IN THE WESTERN ZONES...WITH CFROPA NOT UNTIL
ABOUT 4 HRS AFTER. THE SUN IS BREAKING THRU THE MULTI-LAYERED
CLOUDS...AND TEMPS SHOULD GET INTO THE 60S BEFORE THE CLOUDS ROLL
IN FROM THE WEST. MAXES EXPECTED TO AGAIN BE NEAR-RECORD LEVEL.
SHOWERS ARE PRETTY LIGHT.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE FRONT SHOULD BE THRU THE EASTERN ZONES BY MIDNIGHT. THE
GHUIDANCE DOES BREAK THE SHOWERS INTO A SERIES OF LINES...SO THE
100 POPS MAY BE FAR TOO HIGH FOR EXPECTED COVERAGE - BUT THE FAST
MOVEMENT OF THE SHOWERS AND EXTREMELY HIGH UNCERTAINTY FOR PRECIP
O/O OF 0.25 INCHES BEFORE 00Z IN THE W AND BY 04Z IN THE EAST
MEANS THE 100 POPS ARE THE WAY TO GO. A STRAY RUMBLE OF THUNDER
IS POSS IN THE SE IN CONJUNCTION WITH SPC TSTM AREA AND SEEM IN
LINE WITH HIGH DEWPOINTS AND A FRONT MOVING THRU. BUT LI/S ARE
NOT IMPRESSIVE AT ANY POINT. WINDS WILL BECOME GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE WEST TONIGHT WITH LOW
TEMPERATURES ABOUT 10F ABOVE NORMAL MAXES FOR THIS TIME OF YEAR.
TUESDAY SHOULD ALSO BE MILD FOR THIS TIME OF YEAR...WITH ONLY A
STRAY SHOWER OR TWO IN THE WRN HIGHLANDS. COLD ADVECTION WILL KEEP
TEMPS STEADY OR ONLY RISING A FEW DEGS FROM TUESDAY MORNING TEMPS.
GUSTY WINDS WILL BE THE STORY ON TUESDAY...BUT GUSTS SHOULD STAY
WELL BELOW 30 KTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT. THE VSBY CONDITIONS WILL CONTINUE THROUGH
MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS MORNING...EARLY
THIS AFTERNOON. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO
THE WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES
AFTER 21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER
ACROSS THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR
CIGS WITH IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY
MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...DANGELO/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
850 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION TODAY.
TEMPERATURES WILL BE WARM AGAIN TODAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. SEASONAL TEMPERATURES ARE IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS INTO KDAY AND MOVING QUICKLY EASTWARD. THE COLD FRONT IS
BACK CLOSER TO KIND. ARRIVAL TIME PER LATEST HRRR/RAP/NAM/GFS
ENSEMBLE IS SPOT ON AROUND 19Z IN THE WESTERN ZONES...WITH CFROPA
NOT UNTIL ANOTHER 4 HRS AFTER. WITH SOME SUN BREAKING THRU THE
MULTI-LAYERED CLOUDS...TEMPS SHOULD RISE VERY QUICKLY THIS
MORNING. SHALLOW COOLER AIR IN THE EASTERN VALLEYS - BUT
WIND/MIXING SHOULD HELP THEM GET MILD...TOO. REST OF THE AREA IS
ALREADY IN THE 50S AND KIPT THE WARMEST SPOT /GASP/ AT 60F. MAXES
EXPECTED TO AGAIN BE NEAR-RECORD LEVEL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
HIGHEST POPS WILL BE THRU 02Z...BUT THE FRONT WILL TAKE ANOTHER
COUPLE HRS TO GO THRU...AND WILL LINGER ISOLD SHRA INTO THE EARLY
NIGHT. A STRAY RUMBLE OF THUNDER IS POSS IN THE SE IN CONJUNCTION
WITH SPC TSTM AREA. WINDS WILL BE GUSTY BEHIND THE FRONT AND SOME
SHOWERS ARE EXPECTED IN THE WEST MONDAY NIGHT WITH LOW
TEMPERATURES STILL SLIGHTLY ABOVE NORMAL. TUESDAY SHOULD ALSO BE
MILD FOR THIS TIME OF YEAR...WITH ONLY A STRAY SHOWER OR TWO IN
THE WRN HIGHLANDS. GUSTY WINDS WILL BE THE STORY ON TUESDAY...BUT
GUSTS SHOULD STAY WELL BELOW ADVY THRESHOLD OF 40KTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT. THE VSBY CONDITIONS WILL CONTINUE THROUGH
MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS MORNING...EARLY
THIS AFTERNOON. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO
THE WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES
AFTER 21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER
ACROSS THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR
CIGS WITH IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY
MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/TYBURSKI
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
641 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LEFT A MENTION OF PATCHY FOG THROUGH THE MORNING HOURS OVER THE
SOUTHEAST FORECAST AREA AS VISIBILITIES HAVE BEEN JUMPING ABOVE
AND BELOW 3/4SM THROUGH THE MORNING.
STEADY RAIN NOW MOVING INTO INDIANA WITH A FEW SHOWERS AHEAD IN
OHIO. THIS AREA WILL PROGRESS EASTWARD THROUGH THE EARLY MORNING
BUT WEST OF THE AREA THROUGH SUNRISE. SOME DRIZZLE IS POSSIBLE
OVER THE EASTERN AREAS WHERE EAST FLOW AND DEWPOINTS IN THE LOW TO
MID 50S PERSIST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
EVEN WITH CLOUDS AND SCATTERED SHOWERS AHEAD OF THE APPROACHING
FRONT...ROBUST SOUTHERLY FLOW WILL ALLOW TEMPERATURES TO CLIMB
INTO THE 60S IN ALL LOCATIONS THROUGH MID DAY.
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE...BUT THE TIGHTENING PRES GRADIENT WILL LIKELY
MIX THEM OUT BY AFTN.
COLD FRONT WILL BE APPROACHING THE FORECAST AREA BY MID
AFTN. KEPT THE HIGHEST POPS BETWEEN 18Z- 00Z...STEADILY MOVING
THEM W-E. A STRAY RUMBLE OF THUNDER IS POSS IN THE SE IN
CONJUNCTION WITH SPC TSTM AREA...HOWEVER...THE COOLER START TO
THE DAY IN THE NE SHOULD PRECLUDE THEM FROM HEARING THUNDER. WINDS
WILL BE GUSTY BEHIND THE FRONT AND SOME SHOWERS ARE EXPECTED IN
THE WEST MONDAY NIGHT WITH LOW TEMPERATURES STILL SLIGHTLY ABOVE
NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT...AND MVFR AT IPT. THE VSBY CONDITIONS WILL
CONTINUE THROUGH MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS
MORNING...EARLY THIS AFTERNOON. THE LOW CIGS WILL CONTINUE OUT
AHEAD OF AN APPROACHING FRONT SO EXPECT THE MVFR CIGS TO
CONTINUE. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO THE
WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES AFTER
21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER ACROSS
THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR CIGS WITH
IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
250 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LOWER STRATUS AND PATCHY FOG BEGINNING TO MOVE INTO MY FAR EASTERN
CWA ON A LIGHT EAST FLOW AND DEWPOINTS IN THE LOWER TO MID 50S. A
MID DECK CONTINUES TO OVERSPREAD THE REGION AHEAD OF APPROACHING
FRONT. THIS MAY LIMIT ANY WIDESPREAD LOWERING OF THE FOG BUT WILL
MONITOR FOR POTENTIAL ADVSYS.
WILL HOLD ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS
OF 1SM FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL
AND TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD
DAYBREAK...THE LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF
MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
A SOUTHERLY BREEZE HAS KEPT ANY FOG PROBLEMS FROM KBFD SOUTH THRU
THE WESTERN AND CENTRAL TAF SITES AT BAY. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH PERIODS OF IFR/LIFR
CONDS FROM KIPT SOUTHWARD THRU KMDT/KLNS OVERNIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1243 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LOWER STRATUS AND PATCHY FOG BEGINNING TO MOVE INTO MY FAR EASTERN
CWA ON A LIGHT EAST FLOW AND DEWPOINTS IN THE LOWER TO MID 50S. A
MID DECK CONTINUES TO OVERSPREAD THE REGION AHEAD OF APPROACHING
FRONT. THIS MAY LIMIT ANY WIDESPREAD LOWERING OF THE FOG BUT WILL
MONITOR FOR POTENTIAL ADVSYS.
WILL HOLD ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS
OF 1SM FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL
AND TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD
DAYBREAK...THE LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF
MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ALONG THE EAST COAST SHOULD ENSURE DRY WEATHER
ACROSS CENTRAL PA OVERNIGHT. MAIN AVIATION CONCERN WILL BE THE
POTENTIAL OF LOW CIGS/FOG DEVELOPING LATE TONIGHT ACROSS THE
EASTERN HALF OF THE STATE. A SOUTHERLY BREEZE SHOULD PRECLUDE FOG
PROBLEMS FROM KBFD SOUTH THRU KJST/KAOO. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH IFR/LIFR CONDS
QUITE POSSIBLE FROM KIPT SOUTHWARD THRU KMDT/KLNS LATE TONIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1127 PM EST SUN DEC 13 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
PLENTY OF HIGH CLOUDS COVERED THE STATE LATE THIS EVENING WITH
JUST A SCATTERING OF MID CLOUDS. A SHIELD OF THICKER MID LEVEL
CLOUDS OVER SWRN PENN WILL ADVANCE TO THE ENE ACROSS MUCH OF THE
FCST AREA OVER THE NEXT SEVERAL HOURS. THIS WILL KEEP TEMPS
UNSEASONABLY MILD.
LOWER STRATUS MAY ADVECT WWD/DEVELOP OVER THE WESTERN POCONOS AND
PORTIONS OF THE SUSQ VALLEY VERY LATE TONIGHT...THANKS TO A
GENERALLY WEAK LLVL EAST TO SERLY FLOW OFF THE ATLANTIC. WILL HOLD
ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS OF 1SM
FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL AND
TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD DAYBREAK...THE
LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ALONG THE EAST COAST SHOULD ENSURE DRY WEATHER
ACROSS CENTRAL PA OVERNIGHT. MAIN AVIATION CONCERN WILL BE THE
POTENTIAL OF LOW CIGS/FOG DEVELOPING LATE TONIGHT ACROSS THE
EASTERN HALF OF THE STATE. A SOUTHERLY BREEZE SHOULD PRECLUDE FOG
PROBLEMS FROM KBFD SOUTH THRU KJST/KAOO. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH IFR/LIFR CONDS
QUITE POSSIBLE FROM KIPT SOUTHWARD THRU KMDT/KLNS LATE TONIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
940 PM EST TUE DEC 15 2015
.DISCUSSION...
WINDS HAVE DROPPED TO CALM IN MOST LOCATIONS...AND DEWPOINT
DEPRESSIONS ARE LESS THAN 5 DEGREES F ALREADY IN MANY SPOTS. LATEST
LAMP GUIDANCE POINTS TOWARD FOG DEVELOPING LATER TONIGHT...AND THE
NAM IS ALSO AGRESSIVE WITH FOG...AND THE LATEST HRRR RUNS ARE
TRENDING IN THAT DIRECTION. THE UPDATE WILL INCREASE THE MENTION OF
FOG...BUT CONFIDENCE IS NOT HIGH ENOUGH YET TO GO WITH A DENSE FOG
ADVISORY AS WINDS MAY PROVIDE A LITTLE MIXING TO PREVENT WIDESPREAD
QUARTER MILE VISIBILITIES. ALL OTHER FORECAST ELEMENTS APPEAR ON
TRACK.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
846 PM CST TUE DEC 15 2015
.UPDATE...
THE COLD FRONT IS CURRENTLY ALONG A BURNET TO KERRVILLE TO EAGLE
PASS LINE AND IS SLOWLY PUSHING OFF TO THE SOUTHEAST. THE
PROGRESSION OF THE FRONT IS SLOWER THAN ANY OF THE SYNOPTIC
MODELS FROM EARLIER IN THE DAY...BUT THE RECENT RUNS OF THE HRRR
ARE MORE IN LINE WITH THE CURRENT LOCATION AND SPEED OF THE FRONT.
HAVE TRENDED THE HOURLY TEMP AND DEW POINTS TOWARDS A HRRR
SOLUTION. IN ADDITION HAVE ADDED FOG TO THE SOUTHEAST COASTAL
PLAINS EAST OF A GONZALES TO KENEDY LINE AND SOUTH OF INTERSTATE
10. MOISTURE IS POOLED HERE AHEAD OF THE FRONT AND VISIBILITY IS
ALREADY DOWN TO 5 MILES AT VICTORIA. THE FOG THAT DOES FORM WILL
BE CLEARED OUT BY THE FRONT AS IT MOVES THROUGH JUST BEFORE
SUNRISE. ONGOING SLIGHT POPS WERE KEPT ACROSS AREAS EAST OF I-35
WHERE ISOLATED SHOWERS HAVE BEEN SEEN ON RADAR THROUGH THE
AFTERNOON AND EVENING HOURS.
REMAINDER OF THE FORECAST IS ON TRACK WITH THE FRONT CLEARING OUR
EASTERN COUNTIES AROUND DAYBREAK. COOLER TEMPERATURES...ABOUT 10
DEGREES COOLER THAN TODAY...AND CLEAR SKIES ARE FORECAST FOR THE
DAY ON WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 600 PM CST TUE DEC 15 2015/
UPDATE...00Z AVIATION UPDATE BELOW.
AVIATION...AT 00Z PRE-FRONTAL TROUGH ORIENTED NEAR A GTU-BAZ-HBV
LINE WITH ACTUAL FRONT JUST SOUTH OF A JCT-DRT LINE. BKN MVFR
STRATACU AND ISOLATED -SHRAS PERSISTING EAST OF THE PRE-FRONTAL
TROUGH ACROSS SOUTH-CENTRAL TEXAS. COULD SEE SOME FOG DEVELOPMENT
LATER IN THE EVENING ACROSS THIS AREA AS WELL. AT THIS TIME THINK
VFR CONDITIONS WILL PERSIST ALONG I-35 TAF SITES OF AUS/SAT...BUT
WILL MONITOR TRENDS THROUGH THE EVENING (BKN CEILINGS AROUND
2500-3000 FT MAY WORK BACK INTO AUS PRIOR TO FRONT). FOLLOWED
SLIGHTLY CLOSER TO LATEST HRRR ON FRONTAL TIMING THROUGH
AUS/SAT...AROUND 06Z-08Z WITH A NORTH WIND AROUND 10 KTS
DEVELOPING BEHIND IT. A FEW HIGHER GUSTS 15-20 KTS POSSIBLE.
OTHERWISE VFR CONDITIONS AT AT ALL TAF SITES.
PREV DISCUSSION... /ISSUED 246 PM CST TUE DEC 15 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
LOW-END LIGHT RAIN CHANCES ARE ONGOING THIS AFTERNOON AND WILL
PERSIST THROUGH THE EARLY MORNING HOURS WEDNESDAY FOR EASTERN
ZONES AS A FRONT SLOWLY MOVES THROUGH THE AREA. OUTSIDE OF THIS
WEATHER...QUIET CONDITIONS ARE EXPECTED THROUGH TOMORROW.
A COLD FRONT IS LOCATED ACROSS THE HILL COUNTRY MOVING SOUTHEAST
THIS AFTERNOON. GIVEN THE FRONTAL MOVEMENT DURING PEAK HEATING AND
CLOUDS BREAKING UP...THE DIURNAL TEMPERATURE RISE IS MASKING THE
TEMPERATURE EFFECTS FROM THE FRONT. CLOUDS CONTINUE TO SLOWLY
CLEAR ALONG AND AHEAD OF THE FRONT WITH TEMPERATURES RISING INTO
THE MID 60S FOR THE HILL COUNTRY TO LOW AND EVEN SOME UPPER 70S
ACROSS THE I-35 CORRIDOR TO THE COASTAL PLAINS. AS A RESULT OF
THIS BETTER HEATING AND WHERE HIGHER MOISTURE CONTENT RESIDES...
SOME LIGHT RAIN SHOWERS ARE OCCURRING OVER THE COASTAL PLAINS
NORTH TOWARDS TEMPLE. THE SCATTERED SHOWERS WILL PERSIST THROUGH
THE AFTERNOON AND EVENING AHEAD OF THE FRONT MAINLY ACROSS EASTERN
LOCATIONS INTO FAYETTE...LEE...AND LAVACA COUNTIES. SHOWERS WILL
END FROM WEST TO EAST BY DAWN WEDNESDAY AS THE FRONT PUSHES
THROUGH.
EXPECT A SUNNY DAY WEDNESDAY BUT TEMPERATURES WILL BE NOTICEABLY COOLER
AS 925MB TEMPS FALL FROM NEAR 16-18C TODAY DOWN TO 10-12C
TOMORROW. BUFR SOUNDINGS ALSO INDICATE SHALLOWER MIXING HEIGHTS
AND THIS WILL RESULT IN ABOUT A 10F DEGREE COOL-OFF FROM TODAYS
HIGHS.
LONG TERM (THURSDAY THROUGH TUESDAY)...
NO HAZARDS EXPECTED MINUS A FEW FREEZING TEMPERATURES IN THE HILL
COUNTRY AS QUIET CONDITIONS PERSIST THROUGH THE LATE WEEK AND
WEEKEND. A MORE UNSETTLED PATTERN MAY TAKE FORM EARLY NEXT WEEK
BUT LONG RANGE MODELS HAVE NOT QUITE LOCKED ON TO AN AGREED UPON
SOLUTION.
THURSDAY AND FRIDAY MORNING WILL BE THE COOLEST OF THE WEEK AS THE
DRY AIR BEHIND THE FRONT TODAY AND A REINFORCING SHOT OF COOLER
DRIER AIR OCCURS THURSDAY NIGHT. LOCATIONS ACROSS THE HILL COUNTRY
AND SELECT SPOTS ALONG THE I-35 CORRIDOR WILL DROP BELOW TO NEAR
FREEZING. PWATS WILL REMAIN LOW THROUGH THIS TIME FRAME WITH ONLY
0.3" OR LESS. WITH SUCH LITTLE MOISTURE IN PLACE...THE FRONT THAT
MOVES THROUGH LATE THURSDAY WILL BE DRY. 925MB TEMPS FRIDAY WILL
ONLY BE 5-10C EAST TO WEST THAT WILL RESULT IN HIGHS LIKELY ONLY
REACHING THE MID AND UPPER 50S WITH SOME 60S IN THE FAR SOUTH
TOWARDS COTULLA.
SURFACE AND H5 HEIGHT RIDGING WILL OCCUR INTO THE WEEKEND AND
ALLOW FOR THE AIRMASS TO WARM WITH NEAR TO ABOVE NORMAL
TEMPERATURES. RAIN CHANCES REMAIN LOW OVER THE WEEKEND AS THE
SURFACE HIGH SLOWLY SHIFTS TO US EAST COAST AND GENERAL FLOW
OCCURS AHEAD OF DAMPENED SHORTWAVE TROUGH OVER THE FOUR CORNERS.
THIS WEAK SHORTWAVE AND ATTENDANT SURFACE LOW WILL ATTEMPTED TO
BRING A SURFACE FRONT TOWARDS THE REGION LATE SUNDAY INTO MONDAY
BUT IT MAY GET HUNG UP JUST NORTH OR EAST WITH LIMITED FORCING AND
LOW-LVL CONVERGENCE UNDER THE NEARLY PARALLEL SOUTHWEST FLOW. ONE
THING THIS PATTERN WILL HELP WITH IS MODERATING TEMPS AND MOISTURE
WITH PWATS RISING TO 1.3-1.4" BY LATE SUNDAY. HAVE KEPT RAIN
CHANCES LOW MONDAY INTO TUESDAY FOR NOW GIVEN THIS WEAKLY FORCED
SET-UP. MODELS DIVERGE STARTING TUESDAY WITH EC DEPICTING A
SLIGHTLY STRONGER/DEEPER LONGWAVE TROUGH OVER THE CENTRAL CONUS
AND THE PLACEMENT OF AN EJECTING SHORTWAVE IMPULSE. THIS IS A
WETTER SOLUTION THAN THE GFS PRESENTS WHICH KEEPS THE SHORTWAVE
IMPULSE FARTHER SOUTH. THIS FEATURE WILL NEED TO BE WATCHED
CLOSELY AS WE WILL BE ABOVE NORMAL IN TEMPERATURES AND MOISTURE
AND HEAVY RAINS COULD POTENTIALLY RESULT IN THIS ENVIRONMENT IF
THE LIFTING MECHANISMS LINE UP CORRECTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 74 49 62 37 63 / 30 20 - 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 49 63 33 63 / 30 20 - 0 0
NEW BRAUNFELS MUNI AIRPORT 74 49 63 36 65 / 20 20 - 0 0
BURNET MUNI AIRPORT 70 44 60 33 61 / 20 10 0 0 0
DEL RIO INTL AIRPORT 73 42 65 34 65 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 73 46 61 33 62 / 30 10 - 0 0
HONDO MUNI AIRPORT 71 47 66 33 66 / 20 10 0 0 0
SAN MARCOS MUNI AIRPORT 74 49 62 36 63 / 30 20 - 0 0
LA GRANGE - FAYETTE REGIONAL 74 52 64 38 63 / 30 40 10 - 0
SAN ANTONIO INTL AIRPORT 74 52 65 37 66 / 20 10 - 0 0
STINSON MUNI AIRPORT 75 53 66 38 66 / 20 20 - 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
600 PM CST TUE DEC 15 2015
.UPDATE...00Z AVIATION UPDATE BELOW.
&&
.AVIATION...AT 00Z PRE-FRONTAL TROUGH ORIENTED NEAR A GTU-BAZ-HBV
LINE WITH ACTUAL FRONT JUST SOUTH OF A JCT-DRT LINE. BKN MVFR
STRATACU AND ISOLATED -SHRAS PERSISTING EAST OF THE PRE-FRONTAL
TROUGH ACROSS SOUTH-CENTRAL TEXAS. COULD SEE SOME FOG DEVELOPMENT
LATER IN THE EVENING ACROSS THIS AREA AS WELL. AT THIS TIME THINK
VFR CONDITIONS WILL PERSIST ALONG I-35 TAF SITES OF AUS/SAT...BUT
WILL MONITOR TRENDS THROUGH THE EVENING (BKN CEILINGS AROUND
2500-3000 FT MAY WORK BACK INTO AUS PRIOR TO FRONT). FOLLOWED
SLIGHTLY CLOSER TO LATEST HRRR ON FRONTAL TIMING THROUGH
AUS/SAT...AROUND 06Z-08Z WITH A NORTH WIND AROUND 10 KTS
DEVELOPING BEHIND IT. A FEW HIGHER GUSTS 15-20 KTS POSSIBLE.
OTHERWISE VFR CONDITIONS AT AT ALL TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 246 PM CST TUE DEC 15 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
LOW-END LIGHT RAIN CHANCES ARE ONGOING THIS AFTERNOON AND WILL
PERSIST THROUGH THE EARLY MORNING HOURS WEDNESDAY FOR EASTERN
ZONES AS A FRONT SLOWLY MOVES THROUGH THE AREA. OUTSIDE OF THIS
WEATHER...QUIET CONDITIONS ARE EXPECTED THROUGH TOMORROW.
A COLD FRONT IS LOCATED ACROSS THE HILL COUNTRY MOVING SOUTHEAST
THIS AFTERNOON. GIVEN THE FRONTAL MOVEMENT DURING PEAK HEATING AND
CLOUDS BREAKING UP...THE DIURNAL TEMPERATURE RISE IS MASKING THE
TEMPERATURE EFFECTS FROM THE FRONT. CLOUDS CONTINUE TO SLOWLY
CLEAR ALONG AND AHEAD OF THE FRONT WITH TEMPERATURES RISING INTO
THE MID 60S FOR THE HILL COUNTRY TO LOW AND EVEN SOME UPPER 70S
ACROSS THE I-35 CORRIDOR TO THE COASTAL PLAINS. AS A RESULT OF
THIS BETTER HEATING AND WHERE HIGHER MOISTURE CONTENT RESIDES...
SOME LIGHT RAIN SHOWERS ARE OCCURRING OVER THE COASTAL PLAINS
NORTH TOWARDS TEMPLE. THE SCATTERED SHOWERS WILL PERSIST THROUGH
THE AFTERNOON AND EVENING AHEAD OF THE FRONT MAINLY ACROSS EASTERN
LOCATIONS INTO FAYETTE...LEE...AND LAVACA COUNTIES. SHOWERS WILL
END FROM WEST TO EAST BY DAWN WEDNESDAY AS THE FRONT PUSHES
THROUGH.
EXPECT A SUNNY DAY WEDNESDAY BUT TEMPERATURES WILL BE NOTICEABLY COOLER
AS 925MB TEMPS FALL FROM NEAR 16-18C TODAY DOWN TO 10-12C
TOMORROW. BUFR SOUNDINGS ALSO INDICATE SHALLOWER MIXING HEIGHTS
AND THIS WILL RESULT IN ABOUT A 10F DEGREE COOL-OFF FROM TODAYS
HIGHS.
LONG TERM (THURSDAY THROUGH TUESDAY)...
NO HAZARDS EXPECTED MINUS A FEW FREEZING TEMPERATURES IN THE HILL
COUNTRY AS QUIET CONDITIONS PERSIST THROUGH THE LATE WEEK AND
WEEKEND. A MORE UNSETTLED PATTERN MAY TAKE FORM EARLY NEXT WEEK
BUT LONG RANGE MODELS HAVE NOT QUITE LOCKED ON TO AN AGREED UPON
SOLUTION.
THURSDAY AND FRIDAY MORNING WILL BE THE COOLEST OF THE WEEK AS THE
DRY AIR BEHIND THE FRONT TODAY AND A REINFORCING SHOT OF COOLER
DRIER AIR OCCURS THURSDAY NIGHT. LOCATIONS ACROSS THE HILL COUNTRY
AND SELECT SPOTS ALONG THE I-35 CORRIDOR WILL DROP BELOW TO NEAR
FREEZING. PWATS WILL REMAIN LOW THROUGH THIS TIME FRAME WITH ONLY
0.3" OR LESS. WITH SUCH LITTLE MOISTURE IN PLACE...THE FRONT THAT
MOVES THROUGH LATE THURSDAY WILL BE DRY. 925MB TEMPS FRIDAY WILL
ONLY BE 5-10C EAST TO WEST THAT WILL RESULT IN HIGHS LIKELY ONLY
REACHING THE MID AND UPPER 50S WITH SOME 60S IN THE FAR SOUTH
TOWARDS COTULLA.
SURFACE AND H5 HEIGHT RIDGING WILL OCCUR INTO THE WEEKEND AND
ALLOW FOR THE AIRMASS TO WARM WITH NEAR TO ABOVE NORMAL
TEMPERATURES. RAIN CHANCES REMAIN LOW OVER THE WEEKEND AS THE
SURFACE HIGH SLOWLY SHIFTS TO US EAST COAST AND GENERAL FLOW
OCCURS AHEAD OF DAMPENED SHORTWAVE TROUGH OVER THE FOUR CORNERS.
THIS WEAK SHORTWAVE AND ATTENDANT SURFACE LOW WILL ATTEMPTED TO
BRING A SURFACE FRONT TOWARDS THE REGION LATE SUNDAY INTO MONDAY
BUT IT MAY GET HUNG UP JUST NORTH OR EAST WITH LIMITED FORCING AND
LOW-LVL CONVERGENCE UNDER THE NEARLY PARALLEL SOUTHWEST FLOW. ONE
THING THIS PATTERN WILL HELP WITH IS MODERATING TEMPS AND MOISTURE
WITH PWATS RISING TO 1.3-1.4" BY LATE SUNDAY. HAVE KEPT RAIN
CHANCES LOW MONDAY INTO TUESDAY FOR NOW GIVEN THIS WEAKLY FORCED
SET-UP. MODELS DIVERGE STARTING TUESDAY WITH EC DEPICTING A
SLIGHTLY STRONGER/DEEPER LONGWAVE TROUGH OVER THE CENTRAL CONUS
AND THE PLACEMENT OF AN EJECTING SHORTWAVE IMPULSE. THIS IS A
WETTER SOLUTION THAN THE GFS PRESENTS WHICH KEEPS THE SHORTWAVE
IMPULSE FARTHER SOUTH. THIS FEATURE WILL NEED TO BE WATCHED
CLOSELY AS WE WILL BE ABOVE NORMAL IN TEMPERATURES AND MOISTURE
AND HEAVY RAINS COULD POTENTIALLY RESULT IN THIS ENVIRONMENT IF
THE LIFTING MECHANISMS LINE UP CORRECTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 48 62 37 63 37 / 20 - 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 47 63 33 63 33 / 20 - 0 0 0
NEW BRAUNFELS MUNI AIRPORT 48 63 36 65 34 / 20 - 0 0 0
BURNET MUNI AIRPORT 43 60 33 61 33 / 10 0 0 0 0
DEL RIO INTL AIRPORT 41 65 34 65 33 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 45 61 33 62 33 / 10 - 0 0 0
HONDO MUNI AIRPORT 45 66 33 66 32 / 10 0 0 0 0
SAN MARCOS MUNI AIRPORT 48 62 36 63 35 / 20 - 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 64 38 63 37 / 40 10 - 0 0
SAN ANTONIO INTL AIRPORT 50 65 37 66 36 / 10 - 0 0 0
STINSON MUNI AIRPORT 51 66 38 66 35 / 20 - 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...TREADWAY
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
537 PM CST TUE DEC 15 2015
.AVIATION...
COLD FRONT STILL ON SCHEDULE TO MOVE INTO SOUTHEAST TEXAS OVERNIGHT
AND MOVE OFF THE COAST AFTER SUNRISE TOMORROW MORNING. MAINLY MVFR
CEILINGS AND SOME SHRA ARE EXPECTED AHEAD OF THE FRONT. COULD SEE
SOME TSRA...BUT NOT CONFIDENT ENOUGH TO INCLUDE IN THE TAFS. WINDS
WILL SHIFT TO THE NORTHWEST BEHIND THE FRONT WITH GRADUALLY LIFTING
CEILINGS DURING THE MORNING AND AFTERNOON HOURS. 42
&&
.PREV DISCUSSION... /ISSUED 311 PM CST TUE DEC 15 2015/
DISCUSSION...
WEAK SHOWERS CONTINUE TO INCREASE IN COVERAGE AHEAD OF COLD FRONT
PUSHING ACROSS CENTRAL TX LATE THIS AFTERNOON. LOW LEVEL MOISTURE
CONTINUES TO INCREASE OFF THE GULF AHEAD OF THE FRONT AND SHOULD
ALLOW THESE SHOWERS TO EXPAND/STRENGTHEN THROUGH THE EVENING.
HOWEVER...WV IMAGERY INDICATES MID LEVELS REMAIN QUITE DRY AND
SHOULD INHIBIT RAINFALL TO SOME DEGREE. HIGH RESOLUTION MODELS
SUPPORT THIS TREND ACROSS SERN TX GENERALLY SPREADING FROM NW TO
SE THROUGH THE NIGHT WITH SCATTERED SHOWERS. MOST SITES HAVE
ABOUT A 50-50 CHANCE TO SEE MEASURABLE RAINFALL. AS FRONT PUSHES
OFFSHORE TOMORROW MORNING...RAIN CHANCES WILL BE SHUNTED AWAY FROM
THE AREA AND USHER IN COOLER AND DRIER AIR. MAX TEMPS WEDNESDAY
WILL BE 5-10 DEGREES COOLER THAN TODAY. A REINFORCING COOL FRONT
WILL MOVE THROUGH THE AREA THURSDAY AND BRING COLDER AIR FOR THE
END OF THE WEEK. OVERNIGHT LOWS WILL DIP INTO THE UPPER 30S
INLAND THURSDAY AND FRIDAY MORNING...WITH AFTERNOON HIGHS FRIDAY
HOLDING IN THE 50S. FRIDAY NIGHT/SATURDAY MORNING SHOULD BE OUR
COLDEST MORNING OF THE WEEK WITH TEMPS IN THE LOWER TO MID 30S TO
START THE DAY SATURDAY.
THE AREA SHOULD SEE A WARMER TREND BEGIN THIS WEEKEND AND CONTINUE
INTO NEXT WEEK. SOME DIFFERENCES IN THE ECMWF AND GFS FOR NEXT
WEEK...HOWEVER BOTH HINT AT A MORE UNSETTLED WEATHER BY MID WEEK
WITH RAIN CHANCES RETURNING TO THE FORECAST.
48
MARINE...
SEEING SE WINDS AROUND 15 KTS WELL OFFSHORE THIS AFT WITH 4 FT
SEAS. WILL SEE SCT SHOWERS DEVELOP AHEAD OF AND IN THE VICINITY OF
THE COLD FRONT TONIGHT. EXPECT THE FRONT TO MOVE OFF THE COAST IN
THE 10-12Z WINDOW TOMORROW MORNING. ISOLATED TSRA ARE POSSIBLE.
WINDS IN THE WAKE OF THE FRONT WILL LIKELY SUPPORT SCEC FOR THE
GULF WATERS ON WEDNESDAY. WILL BE A CLOSE CALL ON AN SCA FOR
THE 20-60 NM WATERS WED NIGHT. MODERATE OFFSHORE FLOW WILL PERSIST
THU AND FRI THEN BECOME ONSHORE AND INCREASE ON SAT AND SUN. SHOULD
SEE AT LEAST SCEC CONDITIONS OFFSHORE BY SUNDAY WITH THE MODERATE
TO STRONG ONSHORE FLOW.
33
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 51 62 39 60 37 / 50 10 10 0 0
HOUSTON (IAH) 60 67 43 61 39 / 50 10 10 0 0
GALVESTON (GLS) 64 67 50 61 47 / 50 30 10 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...14
AVIATION/MARINE...42
[top]
Area Forecast Discussion
National Weather Service Midland/Odessa TX
532 PM CST TUE DEC 15 2015
.DISCUSSION...
See 00z aviation discussion below.
&&
.AVIATION...
VFR conditions are expected for the next 24 hours. Winds will
decrease in strength over the next few hours and will remain light
out of a generally westerly direction.
&&
.PREV DISCUSSION... /issued 245 PM CST TUE DEC 15 2015/
DISCUSSION...
WV imagery shows the upper trough ejecting into the upper Midwest,
trailing a Pac front which sfc analysis places in central Texas at
18Z. This has resulted in a brisk day across West Texas and
Southeast New Mexico, w/temps most locations struggling to get out
of the 50s. Out in the Guadalupes, west winds are right at high
wind warning criteria, and the HWW for this afternoon looks good.
HRRR, NAM, and RAP soundings for KGDP all stay mixed to H7 or so
this afternoon, then rapidly decouple after 23Z. Therefore, we have
no problem letting the HWW expire as planned.
Overnight, under clear skies and relaxing pressure gradients, the
first significant freeze for December is in store for much of the
FA, w/the NW half having a hard freeze. Model performance and
reality the past couple of days suggest guidance temps--especially
the MET--may be too cold. Indeed, NAM H85 temps are colder than
both the GFS and ECMWF in the short term, and so we`ve opted to stay
toward the warmer end of guidance.
That said, temps will still stay below normal thru Friday, as
another trough Thursday send a reinforcing shot of cold air our way.
Upper-lvl ridging follows the trough, allowing temps into next week
to climb into the 60s most locations. A series of dry trough will
pass to the north beginning Sunday, but the net result of these attm
just looking to be windy days and maybe a fire wx concern,
especially Sunday.
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...High Wind Warning until 5 PM MST this afternoon FOR THE
FOLLOWING ZONES... Guadalupe Mountains NP/Lincoln NF/LNZ...
Guadalupe Mountains of Eddy County.
TX...High Wind Warning until 5 PM MST this afternoon FOR THE
FOLLOWING ZONES... Guadalupe Mountains.
&&
$$
99
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
253 PM CST MON DEC 14 2015
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
FOCUS FOR THE SHORT TERM WILL CENTER AROUND A FRONTAL PASSAGE
TOMORROW INTO EARLY WEDNESDAY THAT WILL HELP GENERATE ISOLATED TO
SCATTERED (20-40% CHANCE) LIGHT RAIN SHOWERS FOR CENTRAL AND
MAINLY EASTERN LOCATIONS.
WATER VAPOR AND RAP ANALYSIS DEPICT AN EXITING SHORTWAVE TROUGH
OVER THE GREAT LAKES REGION AND AN INCOMING LONGWAVE TROUGH OVER
THE WESTERN BASIN. THIS WESTERN BASIN TROUGH IS NOT NEARLY AS
STRONG OR AS DEEP EQUATORWARD AS THE PREVIOUS SYSTEM BUT IT WILL
SEND A COLD FRONT THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING. FOR TODAY HOWEVER...DRIER AIR IS IN PLACE WITH A NICE
WARM UP OCCURRING. TEMPERATURES ARE IN THE LOW TO MID 70S AREAWIDE
WITH SOME LOCATIONS IN THE UPPER 70S ACROSS THE RIO GRANDE. EXPECT
ANOTHER 2-3F DEGREES FROM CURRENT READINGS WITH THE AMPLE SUN.
HAVE INCREASED MAX HIGHS FOR THIS AFTERNOON IN CONCERT WITH THESE
TRENDS.
OVERNIGHT AND INTO TUESDAY...MOISTURE IS SLATED TO RETURN BACK
INTO THE REGION FROM THE SOUTH BUT VALUES WILL BE SUBDUED.
CURRENT PWATS NEAR 0.3" WILL ONLY RECOVER TO 0.8" BY TUESDAY
AFTERNOON BEFORE THE FRONT ARRIVES. TUESDAY MORNING WILL BE WARMER
GIVEN A BLANKETING CLOUD COVER THAT WILL ALSO HELP GENERATE SOME
LIGHT PATCHY DRIZZLE. THIS LIGHT DRIZZLE AND LIGHT RAIN WILL
PERSIST INTO THE AFTERNOON ALONG AND AHEAD OF THE FRONT THAT MOVES
THROUGH LATE TUESDAY INTO WEDNESDAY MORNING. OVERALL RAINFALL
AMOUNTS ARE EXPECTED TO BE LIGHT WITH AT OR LESS THAN ONE QUARTER
OF AN INCH EXPECTED. CLOUDS LOOK TO HANG ON MOST OF THE DAY
TUESDAY SO LOWER HIGH TEMPERATURES ARE EXPECTED GIVEN NAM/GFS BUFR
SOUNDING OUTPUT.
&&
.LONG TERM (WEDNESDAY THROUGH MONDAY)...
A GENERALLY QUIET AND NEAR NORMAL TEMPERATURE REGIME WILL BE IN
STORE FOR THE REGION THROUGH THE END OF THE WEEK. CLOUDS WILL
RETURN OVER THE WEEKEND WITH A LOW-END RAIN CHANCE BY MONDAY WITH
THE PASSAGE OF ANOTHER DISTURBANCE IN THE CENTRAL PLAINS.
MID TO LATE WEEK WILL BE PLEASANT WITH SUNNY SKIES AND NEAR NORMAL
TEMPERATURES WITH LOWS IN THE LOWER TO MID 40S AND HIGHS IN THE
MID 60S. FRIDAY WILL BE SLIGHTLY COOLER AS RESIDUAL COOL AIR
ADVECTION CONTINUES JUST BEFORE WINDS TURN BACK OUT OF THE SOUTH.
PWATS WILL REMAIN QUITE LOW /0.15-0.3"/ THROUGH FRIDAY BEFORE
INCREASING TO 0.6-0.7" ON SATURDAY. SOUTH WINDS WILL AID THIS PWAT
INCREASE AS A H5 SHORTWAVE TROUGH AND ASSOCIATED SURFACE TROUGH
HELP GENERATE SOUTH FLOW OVER THE REGION. THE EC IS SLIGHTLY
DRIER AS IT DEPICTS ENERGY FARTHER NORTH VS. THE GFS. HAVE HELD
OFF ON INTRODUCING RAIN CHANCES FOR SATURDAY AND SUNDAY AT THIS
TIME BUT DID PLACE A LOW-END 20% FOR MONDAY WHERE BETTER MODEL
AGREEMENT OCCURS. AT THIS PARTICULAR STAGE...PWATS MAY REACH
UPWARDS OF 1.3-1.5" IN THE FAR EAST BEFORE THIS FRONT MOVES
THROUGH MONDAY AND THIS WOULD LIKELY SUPPORT SOME SHOWER ACTIVITY
DESPITE THE SIDESWIPE OF THE TROUGH ENERGY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 72 49 64 38 / 0 30 20 - -
AUSTIN BERGSTROM INTL AIRPORT 47 73 48 64 35 / 0 30 20 10 -
NEW BRAUNFELS MUNI AIRPORT 48 73 50 64 37 / 0 30 20 10 -
BURNET MUNI AIRPORT 49 68 43 60 35 / 0 20 10 - -
DEL RIO INTL AIRPORT 46 66 41 65 36 / 0 - 0 0 0
GEORGETOWN MUNI AIRPORT 50 71 45 61 35 / 0 30 10 - -
HONDO MUNI AIRPORT 48 71 48 66 35 / 0 20 10 - 0
SAN MARCOS MUNI AIRPORT 49 72 49 64 36 / 0 30 20 10 -
LA GRANGE - FAYETTE REGIONAL 51 77 54 64 39 / 0 30 40 10 -
SAN ANTONIO INTL AIRPORT 50 73 51 65 38 / 0 20 10 - -
STINSON MUNI AIRPORT 50 75 53 66 39 / 0 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1248 PM EST MON DEC 14 2015
.SYNOPSIS...
A DEEP LOW PRESSURE AREA WILL MOVE RAPIDLY FROM THE SOUTHERN
PLAINS TOWARD THE GREAT LAKES TODAY...PUSHING A COLD FRONT THROUGH
THE MID-ATLANTIC. WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION
FOR TUESDAY AND WEDNESDAY. LOW PRESSURE WILL THEN DEVELOP ACROSS
THE SOUTHEAST U.S. THURSDAY...PULLING A STRONGER COLD FRONT
THROUGH OUR REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 919 AM EST MONDAY...
MODIFIED TEMPERATURES WITH LATEST OBS AND RAISED HIGH TEMPERATURES
IN SEVERAL LOCATIONS...ESPECIALLY IN THE WEST. SHAPED POPS THIS
MORNING INTO THIS AFTERNOON TOWARDS A HRRR AND HIRESW-ARW BLEND.
WITH KFCX WSR-88D LOOP SHOWING LIGHT MOISTURE SPREADING NORTHEAST
ALONG THE BLUE RIDGE...EXPANDED LIGHT POPS FURTHER EAST THIS
MORNING INTO THIS AFTERNOON. THE 12Z RNK SOUNDING DID SHOWED A
SOUTHWEST 50 KNOT JET AROUND 800 MB WITH A PWAT AT 0.63 INCHES.
WILL HOLD WITH CURRENT WIND ADVISORY UNTIL 7 PM ACROSS HIGHER
TERRAIN WITH THE LOW LEVEL JET ROTATING NORTHEAST THIS MORNING
INTO THIS AFTERNOON. POSTED SPS FOR FOG AND LOW CLOUDS ALONG
INTERSTATE 77 FOR THIS MORNING. MORE CHANGES LATER THIS MORNING...
AS OF 415 AM EST MONDAY...
AWAITING THE LONG ADVERTISED COLD FRONT THIS PERIOD.
COMBINATION OF SYNOPTIC SCALE...GFS/ECMWF/NAM...AND SHORT RANGE
MESOSCALE MODELS...HRRR/RNK-WRF/NCEP-WRF...SHOW CONTINUED SLOWER
PROGRESSION AND WEAKENING OF THE CURRENTLY IMPRESSIVE SYSTEM
ACROSS THE WESTERN TENNESSEE VALLEY. JUST A FEW RUNS BACK OF THE
SYNOPTIC SCALE MODELS WOULD HAVE HAD THE ASSOCIATED LINE OF
CONVECTIVE SHOWERS IN OUR CWA AT 12Z THIS MORNING. INSTEAD...THIS
LINE IS SEVERAL HUNDRED MILES STILL WEST OF THE CWA. LATEST
PROJECTIONS DO NOT SHOW THIS LINE OF CONVECTION REACHING THE
WESTERN PARTS OF THE CWA UNTIL LATE MORNING...THEN SPREADING EAST
DURING THE AFTERNOON/EARLY EVENING. CONSIDERABLE WEAKENING IS ALSO
INDICATED AS THE ACTIVITY ATTEMPTS TO PUSH EAST OF THE BLUE RIDGE
AND THE PARENT UPPER LOW TRACKS NORTH-NORTHEAST TOWARD THE GREAT
LAKES. THIS HAS RESULTED IN SLOWER TIMING OF THE HIGHER POPS INTO
THE CWA AND REDUCED POPS ACROSS EASTERN AREAS.
MEANWHILE...A WARM ADVECTION WING HAS DEVELOPED ACROSS THE
SOUTHEAST PART OF THE CWA INTO CENTRAL NC/SC...AIDED BY
INCREASINGLY MOIST SOUTHERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. AS
A RESULT...SCATTERED SPRINKLES/LIGHT RAIN SHOWERS/DRIZZLE EVIDENT
IN THESE AREAS. MESOSCALE MODELS SHOW THIS HOLDING STEADFAST AND
TRACKING NORTHEAST INTO THE SHENANDOAH VALLEY BY EARLY AFTERNOON
AS THE LINE OF SHOWERS APPROACHES FROM THE WEST. STILL WILL HAVE
CATEGORICAL TO LIKELY POPS ACROSS MOST OF THE CWA THROUGH THE DAY
FROM WEST-EAST AS FEEL MOST LOCATIONS WILL AT LEAST SEE 0.01 INCH.
WITH RESPECT TO THE WIND CONCERN...THE STRONGEST 850MB WINDS ARE
PROGGED TO REACH THE WESTERN BORDER AROUND 12Z...THEN TRANSLATE
NNE WITH THE PARENT UPPER LOW. WINDS DO NOT REALLY SHIFT
APPRECIABLY TO THE WEST/NORTHWEST UNTIL EVENING. CURRENT WIND
ADVISORY IN EFFECT FOR THE HIGHER TERRAIN UNTIL 00Z TUE. WILL
LEAVE AS IS...BUT MAIN CONCERN REMAINS THAT OF WINDS AHEAD OF THE
SHOWERS AND ASSOCIATED WITH THE MORNING LLJ...NOT WINDS BEHIND THE
SHOWERS/TROUGH. MOMENTUM TRANSFER INDICATED VIA BUFKIT IS
POOR...BUT AM OBSERVING WINDS GUSTS IN THE 35-45 MPH RANGE ACROSS
MERCER/TAZEWELL AND ALLEGHANY NC COUNTIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE
PERIOD...BUT NOT AS WARM AS PREVIOUS DAYS THANKS TO CLOUDS AND
PRECIPITATION. STARTING OUT UNSEASONABLY MILD THIS MORNING WITH
MANY AREAS IN THE LOWER TO MIDDLE 60S. TUESDAY MORNING SHOULD BE A
TAD COOLER WITH CLEARING...SLIGHTLY DRIER AIR...HIGH
PRESSURE...AND LESS WIND...BUT NONETHELESS STILL WELL ABOVE NORMAL
WITH NO FREEZING TEMPERATURES INDICATED UNTIL LATE IN THE WEEK.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 236 AM EST MONDAY...
AFTER A BREEZY MORNING TUESDAY...A WEAK AREA OF HIGH PRESSURE WILL
BUILD EAST UNDER SHORT WAVE RIDGING. DESPITE COOLER AIR WORKING INTO
THE REGION...TUESDAY`S AFTERNOON HIGHS WILL REMAIN WARMER THAN
NORMAL WITH UPPER 50S WEST AND MID TO UPPER 60S EAST. THIS AREA OF
HIGH PRESSURE WILL MOVE OVER THE MID ATLANTIC REGION...WEDGING SOUTH
INTO THE CAROLINAS TUESDAY NIGHT. LIGHT SOUTHEASTERLY LOW LEVEL FLOW
AND INCREASING CLOUDS COVER FROM THE SOUTH WILL PRODUCE UNIFORM
TEMPERATURES IN THE UPPER 50S TO LOWER 60S WEDNESDAY. A DISTURBANCE
WILL MOVE OUT OF THE GULF ON WEDNESDAY AND TRACK ALONG THE SOUTHERN
APPALACHIANS WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM WILL BRING
ABOUT AN INCH OF RAIN TO AREAS ALONG AND EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1249 PM EST MONDAY...
MVFR CONDITIONS WITH AREAS OF IFR AND LIFR IN LOW CLOUDS...RAIN
AND FOG WILL CONTINUE THIS AFTERNOON INTO TONIGHT. STRONG
GUSTY SOUTH TO SOUTHWEST WINDS WILL HINDER AVIATION OPERATIONS.
THE STRONGEST LLJ WILL MOVE ACROSS WESTERN PORTIONS OF THE CWA
THIS AFTERNOON...THEN LIFT NORTH TO NORTHEAST TONIGHT TOWARD
WESTERN PENNSYLVANIA. PATCHES OF LIGHT RAIN...DRIZZLE AND FOG
CONTINUE TO LIFT NORTH ACROSS FORECAST AREA THIS AFTERNOON
AHEAD OF THE MAIN BAND OF SHOWERS ASSOCIATED WITH THE FRONT.
WOULD EXPECT MVFR-IFR CIGS WITH SHOWERS...THEN IMPROVING TO VFR
AFT 00Z EAST OF THE BLUE RIDGE WITH INCREASING DOWNSLOPE
WINDS...BUT REMAINING MVFR TO THE WEST. VISIBILITIES SHOULD
GENERALLY REMAIN MVFR OR BETTER WITH MOST OF RAIN SHOWERS EXPECTED
TO BE LIGHT. WINDS BEHIND THE FRONT WILL BECOME WSW-W WITH SPEEDS
MOSTLY BETWEEN 8-10KTS AND LOW END GUSTS UP UNTIL ABOUT 04Z.
SOME MVFR CONDITIONS EXPECTED IN THE WESTERN UPSLOPE REGION OF
SOUTHEAST WEST VIRGINIA TUESDAY. VFR CONDITIONS EXPECTED
ACROSS REST OF TAF LOCATIONS.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984 |
BLUEFIELD | 68 IN 1984 |
DANVILLE | 74 IN 1948 |
LYNCHBURG | 70 IN 1948 |
ROANOKE | 73 IN 1927 |
RECORD HIGH MINIMUM TEMPERATURES FOR....
BLACKSBURG | 49 IN 1991 |
BLUEFIELD | 53 IN 1984 |
DANVILLE | 53 IN 1991 |
LYNCHBURG | 55 IN 1901 |
ROANOKE | 60 IN 1927 |
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007-009-010-
015.
NC...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ042.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...CF
AVIATION...KK/RAB
CLIMATE...CF/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
919 AM EST MON DEC 14 2015
.SYNOPSIS...
A DEEP LOW PRESSURE AREA WILL MOVE RAPIDLY FROM THE SOUTHERN
PLAINS TOWARD THE GREAT LAKES TODAY...PUSHING A COLD FRONT THROUGH
THE MID-ATLANTIC. WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION
FOR TUESDAY AND WEDNESDAY. LOW PRESSURE WILL THEN DEVELOP ACROSS
THE SOUTHEAST U.S. THURSDAY...PULLING A STRONGER COLD FRONT
THROUGH OUR REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 919 AM EST MONDAY...
MODIFIED TEMPERATURES WITH LATEST OBS AND RAISED HIGH TEMPERATURES
IN SEVERAL LOCATIONS...ESPECIALLY IN THE WEST. SHAPED POPS THIS
MORNING INTO THIS AFTERNOON TOWARDS A HRRR AND HIRESW-ARW BLEND.
WITH KFCX WSR-88D LOOP SHOWING LIGHT MOISTURE SPREADING NORTHEAST
ALONG THE BLUE RIDGE...EXPANDED LIGHT POPS FURTHER EAST THIS
MORNING INTO THIS AFTERNOON. THE 12Z RNK SOUNDING DID SHOWED A
SOUTHWEST 50 KNOT JET AROUND 800 MB WITH A PWAT AT 0.63 INCHES.
WILL HOLD WITH CURRENT WIND ADVISORY UNTIL 7 PM ACROSS HIGHER
TERRAIN WITH THE LOW LEVEL JET ROTATING NORTHEAST THIS MORNING
INTO THIS AFTERNOON. POSTED SPS FOR FOG AND LOW CLOUDS ALONG
INTERSTATE 77 FOR THIS MORNING. MORE CHANGES LATER THIS MORNING...
AS OF 415 AM EST MONDAY...
AWAITING THE LONG ADVERTISED COLD FRONT THIS PERIOD.
COMBINATION OF SYNOPTIC SCALE...GFS/ECMWF/NAM...AND SHORT RANGE
MESOSCALE MODELS...HRRR/RNK-WRF/NCEP-WRF...SHOW CONTINUED SLOWER
PROGRESSION AND WEAKENING OF THE CURRENTLY IMPRESSIVE SYSTEM
ACROSS THE WESTERN TENNESSEE VALLEY. JUST A FEW RUNS BACK OF THE
SYNOPTIC SCALE MODELS WOULD HAVE HAD THE ASSOCIATED LINE OF
CONVECTIVE SHOWERS IN OUR CWA AT 12Z THIS MORNING. INSTEAD...THIS
LINE IS SEVERAL HUNDRED MILES STILL WEST OF THE CWA. LATEST
PROJECTIONS DO NOT SHOW THIS LINE OF CONVECTION REACHING THE
WESTERN PARTS OF THE CWA UNTIL LATE MORNING...THEN SPREADING EAST
DURING THE AFTERNOON/EARLY EVENING. CONSIDERABLE WEAKENING IS ALSO
INDICATED AS THE ACTIVITY ATTEMPTS TO PUSH EAST OF THE BLUE RIDGE
AND THE PARENT UPPER LOW TRACKS NORTH-NORTHEAST TOWARD THE GREAT
LAKES. THIS HAS RESULTED IN SLOWER TIMING OF THE HIGHER POPS INTO
THE CWA AND REDUCED POPS ACROSS EASTERN AREAS.
MEANWHILE...A WARM ADVECTION WING HAS DEVELOPED ACROSS THE
SOUTHEAST PART OF THE CWA INTO CENTRAL NC/SC...AIDED BY
INCREASINGLY MOIST SOUTHERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. AS
A RESULT...SCATTERED SPRINKLES/LIGHT RAIN SHOWERS/DRIZZLE EVIDENT
IN THESE AREAS. MESOSCALE MODELS SHOW THIS HOLDING STEADFAST AND
TRACKING NORTHEAST INTO THE SHENANDOAH VALLEY BY EARLY AFTERNOON
AS THE LINE OF SHOWERS APPROACHES FROM THE WEST. STILL WILL HAVE
CATEGORICAL TO LIKELY POPS ACROSS MOST OF THE CWA THROUGH THE DAY
FROM WEST-EAST AS FEEL MOST LOCATIONS WILL AT LEAST SEE 0.01 INCH.
WITH RESPECT TO THE WIND CONCERN...THE STRONGEST 850MB WINDS ARE
PROGGED TO REACH THE WESTERN BORDER AROUND 12Z...THEN TRANSLATE
NNE WITH THE PARENT UPPER LOW. WINDS DO NOT REALLY SHIFT
APPRECIABLY TO THE WEST/NORTHWEST UNTIL EVENING. CURRENT WIND
ADVISORY IN EFFECT FOR THE HIGHER TERRAIN UNTIL 00Z TUE. WILL
LEAVE AS IS...BUT MAIN CONCERN REMAINS THAT OF WINDS AHEAD OF THE
SHOWERS AND ASSOCIATED WITH THE MORNING LLJ...NOT WINDS BEHIND THE
SHOWERS/TROUGH. MOMENTUM TRANSFER INDICATED VIA BUFKIT IS
POOR...BUT AM OBSERVING WINDS GUSTS IN THE 35-45 MPH RANGE ACROSS
MERCER/TAZEWELL AND ALLEGHANY NC COUNTIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE
PERIOD...BUT NOT AS WARM AS PREVIOUS DAYS THANKS TO CLOUDS AND
PRECIPITATION. STARTING OUT UNSEASONABLY MILD THIS MORNING WITH
MANY AREAS IN THE LOWER TO MIDDLE 60S. TUESDAY MORNING SHOULD BE A
TAD COOLER WITH CLEARING...SLIGHTLY DRIER AIR...HIGH
PRESSURE...AND LESS WIND...BUT NONETHELESS STILL WELL ABOVE NORMAL
WITH NO FREEZING TEMPERATURES INDICATED UNTIL LATE IN THE WEEK.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 236 AM EST MONDAY...
AFTER A BREEZY MORNING TUESDAY...A WEAK AREA OF HIGH PRESSURE WILL
BUILD EAST UNDER SHORT WAVE RIDGING. DESPITE COOLER AIR WORKING INTO
THE REGION...TUESDAY`S AFTERNOON HIGHS WILL REMAIN WARMER THAN
NORMAL WITH UPPER 50S WEST AND MID TO UPPER 60S EAST. THIS AREA OF
HIGH PRESSURE WILL MOVE OVER THE MID ATLANTIC REGION...WEDGING SOUTH
INTO THE CAROLINAS TUESDAY NIGHT. LIGHT SOUTHEASTERLY LOW LEVEL FLOW
AND INCREASING CLOUDS COVER FROM THE SOUTH WILL PRODUCE UNIFORM
TEMPERATURES IN THE UPPER 50S TO LOWER 60S WEDNESDAY. A DISTURBANCE
WILL MOVE OUT OF THE GULF ON WEDNESDAY AND TRACK ALONG THE SOUTHERN
APPALACHIANS WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM WILL BRING
ABOUT AN INCH OF RAIN TO AREAS ALONG AND EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 645 AM EST MONDAY...
MOISTURE ADVECTION AHEAD OF THE STRONG WEATHER SYSTEM TO OUR WEST
HAS RESULTED IN LOWERING CIGS OVERNIGHT...ESPECIALLY ALONG AND
SOUTHEAST OF THE BLUE RIDGE. WIDESPREAD MVFR-IFR CIGS FROM NORTHWEST
NC NORTHEAST TOWARD KLYH. THESE CEILINGS HAVE STILL NOTE QUITE
SPREAD TO THE NORTHWEST YET...BUT KBLF IS ON THE EDGE OF BECOMING
MVFR/IFR...AS IS KLWB. DECOUPLING EARLIER ACROSS PARTS OF THE
PIEDMONT AND THE GREENBRIER VALLEY ALLOWED FOR BRIEF IFR-LIFR BR
AND ASSOCIATED CIGS. HOWEVER...THIS HAS DISPERSED NOW WITH
STRONGER SOUTHERLY FLOW AND CLOUDS IN ADVANCE OF THE SYNOPTIC
SCALE SYSTEM TO THE WEST.
WINDS HAVE BEGUN TO BACK TO THE SSE AS THE UPPER TROUGH/FRONT
APPROACH. AS EXPECTED...KBLF HAS BEEN GUSTING INTO THE 20-28KT
RANGE MUCH OF THE NIGHT. STRONGEST LLJ WILL APPROACH THE WESTERN
BORDER OF THE CWA DURING THE MID-MORNING...THEN LIFT NNE TOWARD
THE OH VALLEY/WESTERN PA. LOW END GUSTS ARE POSSIBLE FURTHER
EAST...BUT PROBABILITY FOR THIS APPEARS TO BE LOW. WILL CONTINUE
WITH THE LLWS FOR KLWB/KBCB WHERE WINDS HAVE DECOUPLED AND THERE
IS A RAPID INCREASE IN SPEED JUST OFF THE SURFACE. MORNING
SOUNDING FROM KRNK SHOWED AN ALMOST 50KT INCREASE IN WINDS BETWEEN
THE SURFACE AND 850MB.
MODELS HAVE CONTINUED TO SLOW DOWN THE ARRIVAL OF THE SYNOPTIC
SYSTEM AND ASSOCIATED NARROW LINE OF SHOWERS. WHILE SOME -SHRA OR
-DZ HAS BEEN NOTED ALONG THE SOUTHWEST PARTS OF THE BLUE RIDGE
INTO SOUTHWEST VA...BONAFIDE -SHRA WILL LIKELY NOT REACH THE
WESTERN PART OF THE CWA UNTIL MID OR LATE MORNING. MOST MODELS
ALSO SHOW A DISSIPATION OF ACTIVITY AS IT ATTEMPTS TO SPREAD
FURTHER EAST. WOULD EXPECT MVFR-IFR CIGS TO HOLD MUCH OF THE DAY
UNTIL THE SHOWERS ARRIVE...IMPROVING TO VFR AFT 00Z EAST OF THE
BLUE RIDGE WITH INCREASING DOWNSLOPE WINDS...BUT REMAINING MVFR TO
THE WEST. VISIBILITIES SHOULD GENERALLY REMAIN MVFR OR BETTER
THROUGH THE DAY AS RAIN SHOWERS ARE EXPECTED TO BE LIGHT. WINDS
BEHIND THE FRONT WILL BECOME WSW-W WITH SPEEDS MOSTLY BETWEEN
8-10KTS AND LOW END GUSTS UP UNTIL ABOUT 04Z.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984 |
BLUEFIELD | 68 IN 1984 |
DANVILLE | 74 IN 1948 |
LYNCHBURG | 70 IN 1948 |
ROANOKE | 73 IN 1927 |
RECORD HIGH MINIMUM TEMPERATURES FOR....
BLACKSBURG | 49 IN 1991 |
BLUEFIELD | 53 IN 1984 |
DANVILLE | 53 IN 1991 |
LYNCHBURG | 55 IN 1901 |
ROANOKE | 60 IN 1927 |
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007-009-010-
015.
NC...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ042.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...CF
AVIATION...JH/KK/RAB
CLIMATE...CF/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1130 PM EST SUN DEC 13 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL SLOWLY WEAKEN AND PUSH
OFFSHORE OVERNIGHT ALLOWING A RETURN SOUTHERLY FLOW OF LOW LEVEL
MOISTURE TO TAKE PLACE BY EARLY MONDAY. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY BEFORE SLIDING THROUGH THE AREA MONDAY NIGHT.
WEAK HIGH PRESSURE FOLLOWS THE FRONT BRINGING DRIER WEATHER AND
CONTINUED WARM TEMPERATURES INTO MID WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 815 PM EST SUNDAY...
WARMTH CONTINUES TO ROLL ON IN MID DECEMBER WITH ADDED RECORDS
ESTABLISHED THIS AFTERNOON PER THE CLIMATE SECTION BELOW WITH
ANOTHER MILD OVERNIGHT TO FOLLOW. LATEST EVENING SOUNDINGS SHOW
CONTINUED VERY DRY AIR ALOFT THIS EVENING AHEAD OF THE STRONG
UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT JUST WEST OF THE
MISSISSIPPI RIVER. HOWEVER SEEING PLENTY OF MID/HIGH CLOUDS SPILL
EAST FROM THE CONVECTION TO THE WEST AND THIS TREND LOOKS TO
PREVAIL OVERNIGHT GIVEN THE STRONG WESTERLY FLOW ALOFT. APPEARS
THIS CANOPY LIKELY TO KEEP THE LID ON WIDESPREAD FOG GIVEN LIMITED
RADIATIVE COOLING AND SUPPORTED BY UNFAVORABLE FORECAST FOG
STABILITY VALUES OFF SOUNDINGS TOWARD DAYBREAK MONDAY. LOOKS LIKE
BEST CHANCE AT FOG WILL BE OVER THE SOUTH AND EAST WHERE CLOUDS
MAY THIN MORE SO KEEPING BETTER COVERAGE THERE.
OTRW EXPECT LOW LEVEL MOISTURE TO GRADUALLY INCREASE OVER THE SW
ONCE THE FLOW TURNS A LITTLE MORE SE LATER ALLOWING SOME PATCHY
LIGHT SHOWERS TO DEVELOP WITHIN A WEAK ISENTROPIC/UPSLOPE REGIME.
LATEST HRRR HOLDS MOST COVERAGE OFF UNTIL AFTER MIDNIGHT AND ONLY
HAS SPOTTY SHOWERS DEVELOPING AT BEST. THUS DELAYING ONSET A BIT
PER DRYNESS AND TRIMMING BACK ON HIGH POPS UNTIL EARLY MONDAY.
LITTLE CHANGE AS WELL TO THE GOING WIND ADVISORY AS APPEARS THE
BEST LOW LEVEL JET ALSO WONT ARRIVE OUT WEST UNTIL AROUND DAYBREAK
WITH STRONGER WINDS POSSIBLE ON THE RIDGES INTO MIDDAY MONDAY.
TEMPS TO STAY MILD UNDER MAINLY CLOUDY SKIES OVERNIGHT WITH MOST
LINGERING IN THE 50S. HOWEVER DO EXPECT THE VALLEYS AND OUTLYING
EASTERN LOCATIONS TO DIP INTO THE 40S BEFORE LIKELY RISING LATE AS
CLOUDS THICKEN MORE AND MIXING PICKS UP.
PREVIOUS DISCUSSION AS OF 345 PM EST SUNDAY...
MAINTAINING THE PATTERN OF BROAD UPPER LEVEL RIDGING ACROSS THE
EASTERN HALF OF THE NATION THIS AFTERNOON...WHILE A DEEP UPPER
LEVEL LOW TRACKS NORTHEAST NEAR THE TEXAS PANHANDLE. IN THE LOW
LEVELS... HIGH PRESSURE IS CENTERED OFF THE CAROLINA COAST...WITH
SOUTH- WESTERLY WINDS ON THE BACKSIDE OF THE HIGH DRAWING WARM
GULF MOISTURE NORTHWARD ACROSS THE OUR AREA. DESPITE THICKENING
HIGH CLOUDS MOVING IN FROM THE WEST AS THE UPPER LOW APPROACHES...
TEMPERATURES ACROSS THE AREA WERE ABLE TO REBOUND AFTER
WIDESPREAD FOG LINGERED INTO LATE MORNING...REACHING INTO THE MID
60S TO THE LOW 70S.
WIND SPEEDS WILL INCREASE FROM WEST TO EAST HEADING INTO LATE
EVENING AS THE COLD FRONT ASSOCIATED WITH THE UPPER LEVEL LOW
APPROACHES FROM THE WEST...CAUSING THE PRESSURE GRADIENT ACROSS
THE REGION TO TIGHTEN. WEATHER FORECAST MODELS ARE IN DECENT
AGREEMENT THAT THE LOW LEVEL JET WILL RAMP UP TO AROUND 60 MPH
TOWARD DAWN MONDAY ACROSS THE MOUNTAINS. WITH SOUTHERLY WINDFLOW
IN PLACE...DOWNSLOPING ON THE WEST SIDE OF THE RIDGES FROM THE
HIGHLANDS OF NORTH CAROLINA INTO EXTREME SOUTHEAST WEST VIRGINIA
WILL BRING SOME OF THE STRONGER JET WINDS TO THE SURFACE. AS
SUCH...WILL CONTINUE WITH THE WIND ADVISORY IN EFFECT FROM MIDNIGHT
TONIGHT THROUGH 7 PM MONDAY.
BELIEVE THIS WILL BE ONE OF THOSE NIGHTS WHERE OVERNIGHT LOWS
OCCUR EARLIER IN THE NIGHT...AND THEN COOLING WILL SLOW/STOP AS THE
WINDSPEEDS INCREASE TOWARD DAWN. WHERE FOG WAS WIDESPREAD
THIS MORNING...BELIEVE IT WILL BE MORE SPOTTY IN NATURE LATE
TONIGHT DUE TO INCREASED CLOUDS...FOUND MORE SO ACROSS THE
SOUTHSIDE WHERE WINDSPEEDS WILL REMAIN LOWER. INSTEAD...EXPECT LOW
CLOUDS TO INCREASE ACROSS THE MOUNTAINS/FOOTHILLS AFTER
MIDNIGHT...WITH ONLY POCKETS OF LIGHT RAIN OR DRIZZLE POSSIBLE
ALONG THE RIDGES. OVERNIGHT LOWS WILL FALL INTO THE UPPER 40S TO
THE MID 50S.
SHOWER ACTIVITY WILL INCREASE AFTER SUNRISE AS THE COLD FRONT PASSES
EAST OF THE MISSISSIPPI RIVER TOWARD THE APPALACHIANS. EXPECT MAINLY
SHOWER ACTIVITY THROUGH LATE MORNING...WHEN THE MAIN UPPER LEVEL
SUPPORT WILL ARRIVE ALONG OUR WESTERN BORDER...TRIGGERING A SOLID
LINE OF RAIN SHOWERS. DO NOT SEE MUCH INSTABILITY TO SUPPORT THE
POTENTIAL FOR THUNDER WITH THIS LINE...ALTHOUGH IT CANNOT BE
ENTIRELY RULED OUT. HOWEVER...LOW LEVEL SHEAR/HELICITY WILL BE
STRONG ENOUGH THAT SOME OF THE STRONGER SHOWERS WILL STILL BE
CAPABLE OF PRODUCING LOCALLY STRONG WIND GUSTS. THE COLD FRONT WILL
FINALLY ENTER OUR SOUTHEAST WEST VIRGINIA/MOUNTAIN EMPIRE COUNTIES
DURING EARLY AFTERNOON...AND WILL EXIT OUR AREA TO THE EAST SHORTLY
BEFORE MIDNIGHT. FRONTAL PASSAGE WILL BRING WITH IT A WESTERLY WIND
SHIFT THAT WILL BRING ONLY SLIGHTLY COOLER AIR.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 236 PM EST SUNDAY...
NOT TOO MUCH CHANGE FROM PREVIOUS FORECAST THIS PERIOD. HAVE
INCREASED WIND GUSTS FOR LATE MONDAY NIGHT/EARLY TUESDAY MORNING AS
ANOTHER PIECE OF HIGHER WINDS AT 8H MOVING ACROSS THE AREA...WITH
6HR PRESSURE RISES OF 4-7MB. THINK AT THIS POINT THAT WIND ADVISORY
LEVELS WILL BE LIMITED TO A FEW HIGHER RIDGES LIKE MT ROGERS...SO
NOT GOING TO EXTEND THE WIND ADVISORY CURRENTLY IN EFFECT...WHICH IS
MAINLY FOR THE STRONG WINDS AHEAD OF THE FRONT.
WE SHOULD SEE THE FRONT CLEAR THE PIEDMONT BY MIDNIGHT....WITH
DRYING TAKING PLACE PRIOR TO THIS. THERE IS NO SUBSTANTIAL AIRMASS
CHANGE BEHIND IT...CONTINENTAL...SO LOWS TUESDAY MORNING WILL STILL
BE ABOVE NORMAL...FROM THE LOWER TO MID 40S MOUNTAINS...TO NEAR 50
EAST.
TUESDAY...SHORTWAVE RIDGE PUSHES ACROSS THE SOUTHEAST TO THE
MIDWEST. FAST FLOW ALOFT MAY BRING SOME CIRRUS TO OUR AREA...WITH
LINGERING STRATOCU IN THE WV MTNS. WINDS WILL BE GUSTY EARLY...THEN
WEAKENING BY DUSK. A MILD DAY WITH HIGHS FROM THE MID TO UPPER 50S
WEST...TO THE MID 60S EAST.
HIGH PRESSURE BUILDS OVERHEAD TUESDAY NIGH ALLOWING FOR FALLING
TEMPERATURES IN THE VALLEYS...WITH RETURN FLOW KICKING IN LATE OVER
THE WRN RIDGES. WITH MAINLY CLEAR SKIES TEMPS SHOULD FALL TO THE
LOWER TO MID 30S IN THE VALLEYS...WITH UPPER 30S/NEAR 40 ELSEWHERE.
WEDNESDAY...HIGH PRESSURE SHIFTS OFFSHORE WITH SW FLOW INCREASING
ALOFT. SHOULD SEE INCREASING CLOUDS LATE IN THE DAY...BUT ANY
SHOWERS WILL HOLD OFF UNTIL WEDNESDAY NIGHT...WITH BEST CONVERGENCE
OF MOISTURE SHIFTING FROM THE SOUTHERN APPALACHIANS AT MIDNIGHT TO
THE VIRGINIA PIEDMONT BY 12Z THU. BEFORE THE CLOUDS MOVE IN
WEDNESDAY WE SHOULD SEE TEMPS WARM INTO UPPER 50S TO MID 60S. WITH
THE HIGH OVER THE NORTHEAST TO MID ATLANTIC...THE SF FLOW WILL BE
MORE OUT OF THE SE WHICH MAY KEEP THINGS COOLER. POTENTIAL DOES
EXIST THAT IF THE FLOW CAN TURN AROUND MORE TO THE SOUTH OR
SOUTHWEST BEFORE THE CLOUDS ENTER THE PICTURE...TEMPS MAY RISE MORE
INTO THE MID 60S OUT EAST.
WEDNESDAY NIGHT LOOKS SOMEWHAT MILD WITH CLOUDS BUT RAIN SHOWERS
SHOULD LOWER READINGS TO THE DEWPOINTS...WITH MOST LOCATIONS HAVING
LOWS IN THE MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 1115 PM EST SUNDAY...
VFR CONDITIONS WILL CONTINUE TO LINGER A FEW MORE HOURS INTO THE
OVERNIGHT UNDER HIGH/MID CLOUDS BEFORE PATCHY FOG STARTS TO
DEVELOP AND LOW LEVEL MOISTURE INCREASES. THIS AHEAD OF A COLD
FRONT THAT WILL APPROACH FROM THE WEST OVERNIGHT INTO
MONDAY...CAUSING THE PRESSURE GRADIENT TO TIGHTEN AND SOUTHERLY
WINDS TO INCREASE...ESPECIALLY ACROSS THE HIGHER WESTERN RIDGES.
THE LOW LEVEL JET WILL RAMP UP TO AROUND 50 KTS NEAR KBLF...AND
DOWNSLOPING IN THE NEARBY TERRAIN MAY RESULT IN OCCASIONAL 25 TO
35 KT GUSTS AT THE AIRPORT TOWARD DAWN. PILOTS SHOULD WATCH FOR
LOW LEVEL WINDS SHEAR LATE TONIGHT INTO MONDAY MORNING ESPECIALLY
OVER THE MOUNTAIN LOCATIONS WHERE SURFACE WINDS WILL BE LIGHTER
SUCH AS AT KLWB/KBCB.
EXPECT A RETURN OF MVFR/IFR CONDITIONS LATE TONIGHT AS STRATUS
DEVELOPS ACROSS MUCH OF THE AREA...STARTING PRIOR TO DAWN ON
MONDAY. THE TAF SITE WITH THE BEST CHANCE FOR IFR CONDITIONS IS
KDAN WITH LOW CLOUDS/FOG GIVEN LIGHT WINDS AND LOW LEVEL MOISTURE
MOVING UP FROM THE SOUTH. EXPANDING LOW LEVEL MOISTURE WILL LIFT
NORTHWARD FROM SOUTHWEST TO NORTHEAST LATER TONIGHT INTO MONDAY
MORNING. ALONG THE SOUTHERN BLUE RIDGE WILL HAVE THE GREATEST
OPPORTUNITY FOR SHOWERS AND LIGHT RAIN OVERNIGHT INTO EARLY
MONDAY.
AS THE COLD FRONT ENTERS EASTERN KENTUCKY AND TENNESSEE MONDAY
MORNING...LOW MVFR/IFR CONDITIONS WILL DEVELOP ACROSS ALL OF THE
REGION. LOW MVFR/IFR CONDITIONS WILL REMAIN ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON AS RAIN SHOWERS PASS ACROSS AHEAD OF THE
APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE EAST MONDAY INTO
MONDAY NIGHT...REACHING THE ATLANTIC COAST TUESDAY MORNING. BRIEF
BURSTS OF HEAVIER SHOWERS MAY RESULT IN MVFR TO OCNL IFR VSBYS
ESPECIALLY WHERE FOG MIXES IN THROUGH MONDAY. IN ADDITION... CAN
NOT RULE OUT GUSTY WINDS WITH THE STRONGER SHOWERS. STRONG WEST TO
NORTHWEST WINDS ARE POSSIBLE BEHIND THE COLD FRONT MONDAY AND
MONDAY NIGHT AS DRIER AIR SWINGS IN FROM THE WEST. THIS SHOULD
SHUT OFF MOST SHOWERS BY MIDNIGHT MONDAY NIGHT BUT STILL EXPECT
OVERALL MVFR CIGS DURING THE EVENING WITH IMPROVING CONDITIONS
OVERNIGHT.
MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984
BLUEFIELD | 68 IN 1984
DANVILLE | 74 IN 1948
LYNCHBURG | 70 IN 1948
ROANOKE | 73 IN 1927
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR VAZ007-009-010-015.
NC...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...WP
LONG TERM...CF
AVIATION...JH/KK/NF
CLIMATE...CF/DS/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1254 AM EST WED DEC 16 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL PREVAIL ACROSS THE AREA INTO EARLY WEDNESDAY.
A SLOW MOVING FRONTAL SYSTEM WILL IMPACT THE AREA LATE WEDNESDAY
THROUGH EARLY FRIDAY. COLD HIGH PRESSURE RETURNS FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
OVERNIGHT...TEMPERATURES CONTINUE TO FALL UNDER CLEAR SKIES AND A
DECOUPLED ATMOSPHERE. EXCELLENT RADIATIONAL COOLING SHOULD
CONTINUE THROUGH MUCH OF THE NIGHT ACROSS A LARGE PORTION OF THE
AREA. THE EXCEPTION IS ACROSS PARTS OF FAR SOUTHEAST GEORGIA WHERE
WEAK ISENTROPIC ASCENT ATOP A STATIONARY FRONT NOT TOO FAR
OFFSHORE COULD ALLOW SOME LATE NIGHT STRATOCUMULUS TO DEVELOP AND
SLOW THE DOWNWARD TEMPERATURE PROGRESSION. OVERALL...EXPECT A
RATHER LARGE NW-SE TEMPERATURE GRADIENT...WITH LOWS RANGING FROM
THE LOWER AND MIDDLE 40S NORTH AND WEST TO LOWER-MIDDLE 50S AT AND
NEAR THE COAST...INCLUDING DOWNTOWN CHARLESTON.
RADIATION FOG IS LIKELY OVERNIGHT WITH FOG STABILITY INDICES IN
THE SINGLE DIGITS AND TEENS...AND WITH SOME HIGHER RESOLUTION
MESOSCALE MODELS SUCH AS THE RAP AND HRRR INDICATING THE POTENTIAL
FOR REDUCED VISIBILITIES AS WELL. HOWEVER...GIVEN THAT THE LOWEST
CONDENSATION PRESSURE DEFICITS REMAIN JUST TO OUR NORTH/NW IT
SHOULDN/T BE TOO WIDESPREAD AND/OR DENSE. WILL MAINTAIN PATCHY FOG
IN THE FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
WEAK SURFACE HIGH PRESSURE WILL PERSIST ON WEDNESDAY WHILE THE
FLOW ALOFT GRADUALLY BACKS AND STRENGTHENS IN RESPONSE TO A
DIGGING UPPER TROUGH TO THE WEST. WEAK MOIST ISENTROPIC ASCENT
WILL DEVELOP DURING THE AFTERNOON...RESULTING IN A GRADUAL
INCREASE IN CLOUD COVER FROM SOUTH TO NORTH AND LOW-END CHANCES OF
RAIN LATE IN THE DAY. FAIRLY GOOD INSOLATION IN ADVANCE OF THE
CLOUDS AND A WARM AIRMASS WILL SUPPORT HIGH TEMPS IN THE MIDDLE
70S.
A STRENGTHENING SOUTHERLY LOW-LEVEL JET WEDNESDAY NIGHT INTO
THURSDAY WILL ALLOW A WARM FRONT TO LIFT NORTH THROUGH THE AREA
AND SPREAD A MOIST AIRMASS INTO THE SOUTHEAST STATES AHEAD OF THE
COLD FRONT. PWATS EXPECTED TO RANGE FROM 1.75" TO 2" BY MIDDAY
THURSDAY. THERE SHOULD BE A FEW RAIN SHOWERS MOVING THROUGH IN
ASSOCIATION WITH THE WARM FRONT...BUT THE BEST FORCING ARRIVES
LATER ON THURSDAY. FRONTAL FORCING COMBINED WITH MODEST UPPER JET
DIVERGENCE IN CONCERT WITH SIGNIFICANTLY ABOVE-NORMAL PWATS SHOULD
ALLOW FOR WIDESPREAD SHOWERS TO DEVELOP THURSDAY INTO THURSDAY
NIGHT. SURFACE-BASED CAPES OF 500-1000 J/KG AND LIFTED INDICES -2
TO -4C THURSDAY AFTERNOON INDICATE AT LEAST ISOLATED THUNDERSTORM
POTENTIAL. LOW-LEVEL WINDS WILL BE QUITE STRONG ON THURSDAY WITH
925 MB WINDS AROUND 40 KT FROM THE SSW. POCKETS OF MODERATE
INSTABILITY AND STRONG WIND FIELDS MAY SUPPORT AN ISOLATED RISK
FOR A STRONG/SEVERE STORM LATER IN THE DAY. AT A MINIMUM WE EXPECT
BREEZY CONDITIONS AND HIGH TEMPS IN THE MID TO UPPER 70S.
MODELS HAVE SLOWED DOWN THE FRONTAL PROGRESSION SLIGHTLY...KEEPING
A FAIRLY GOOD COVERAGE OF SHOWERS OVER THE AREA THROUGH THURSDAY
NIGHT. IMPROVING CONDITIONS ANTICIPATED FRIDAY WITH CLEARING SKIES
BY AFTERNOON. LATE DAY COLD ADVECTION WILL KEEP TEMPS IN THE UPPER
50S FAR INLAND BUT WE BUMPED HIGHS INTO THE MID 60S NEAR THE COAST
WHERE THE WARM ADVECTION WILL PERSIST THE LONGEST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SURFACE HIGH PRESSURE ACROSS THE CENTRAL U.S. FRIDAY NIGHT WILL MOVE
OVER OR JUST NORTH OF OUR AREA SUNDAY...THEN MOVE OUT TO SEA ON
MONDAY. COLD NORTHWEST FLOW RESULTING FROM THIS HIGH WILL LEAD TO
MUCH COLDER TEMPERATURES THAN THE AREA HAS BEEN EXPERIENCING.
SATURDAY HIGHS WILL BE IN THE MID 50S WHILE SUNDAY MORNING LOWS WILL
BE IN THE LOW TO MID 30S...ABOUT 5 DEGREES BELOW NORMAL.
TEMPERATURES SHOULD BEGIN MODERATING SUNDAY AND MONDAY AS HEIGHTS
BUILD AND FLOW TURNS SOUTHWESTERLY. BUT A COASTAL TROUGH MAY ALSO
DEVELOP BOTH DAYS...LEADING TO POSSIBLY SOME SHOWERS ALONG THE
IMMEDIATE COAST.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THERE IS A POTENTIAL FOR MAINLY PATCHY SHALLOW GROUND FOG TO
DEVELOP OVERNIGHT RESULTING IN POSSIBLE VISIBILITIES RESTRICTIONS.
THERE APPEARS TO BE A SLIGHTLY GREATER POTENTIAL FOR FOG AT KCHS
SO HAVE INDICATED MVFR/IFR VISIBILITIES THERE...BUT HELD VSBYS TO
6SM AT KSAV FOR THE TIME BEING. OTHERWISE...VFR CONDITIONS WILL
PREVAIL AT THE TERMINALS.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS EXPECTED
LATER TONIGHT THROUGH FRIDAY MORNING AS A FRONTAL SYSTEM AFFECTS
THE AREA.
&&
.MARINE...
OVERNIGHT...A WEAK PRESSURE PATTERN WILL INFLUENCE CONDITIONS
ACROSS THE ATLANTIC AND IN THE CHARLESTON AND SAVANNAH HARBORS.
WINDS WILL STEADILY CLOCK AROUND TO THE WEST AT LESS THAN 5 OR 10
KT TONIGHT. THE NOSE OF HIGH PRESSURE ARRIVING FROM THE NORTH LATE
WILL CAUSE WINDS TO VEER FURTHER TO THE NORTH/NE BY DAYBREAK. NOT
MUCH WAVE ACTION IN GENERAL...ALTHOUGH BUOY SITES IN AND NEAR THE
LOCAL WATERS SHOWING A VERY SMALL 12-14 SECOND SWELL FROM THE
EAST/NE THAT WILL CONTINUE.
WEDNESDAY AND WEDNESDAY NIGHT WILL FEATURE FAIRLY LIGHTLY WINDS
AND MARGINAL SEAS DUE TO HIGH PRESSURE IN PLACE. A STRONG LOW-
LEVEL JET DEVELOPS ON THURSDAY AHEAD OF A COLD FRONT. WE COULD SEE
GUSTS APPROACHING SMALL CRAFT CRITERIA OVER THE OUTER WATERS OR
PERHAPS IN CHARLESTON HARBOR. A BETTER CHANCE FOR SMALL CRAFT
CONDITIONS WILL SETUP FRIDAY INTO FRIDAY NIGHT AS STRONG COLD
ADVECTION BLOWS OVER THE WATERS BEHIND THE COLD FRONT. BROAD HIGH
PRESSURE OVER THE WEEKEND WILL YIELD DIMINISHING WIND AND SEA
CONDITIONS.
SEA FOG...THERE IS AGAIN THE POTENTIAL FOR SEA FOG LATE WEDNESDAY
NIGHT THROUGH THURSDAY EVENING AS A WARM AND HUMID AIR MASS MOVES
IN OVER THE COOLER SHELF WATERS.
&&
.CLIMATE...
THERE IS A GOOD CHANCE THAT RAINFALL AT THE END OF THIS WEEK WILL
PUSH THE YEARLY RAINFALL TOTAL AT THE CHARLESTON INTERNATIONAL
AIRPORT /KCHS/ ABOVE THE ALL TIME YEARLY PRECIPITATION RECORD. THE
CURRENT RECORD IS 72.99 INCHES THAT WAS SET IN 1964. RECORDS FOR
THE CHARLESTON INTERNATIONAL AIRPORT DATE BACK TO 1938.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
CLIMATE...
AREA FORECAST DISCUSSION
NWS JACKSON KY
1221 AM EST WED DEC 16 2015
.UPDATE...
ISSUED AT 1000 PM EST TUE DEC 15 2015
SURFACE HIGH PRESSURE ACROSS THE EASTERN OHIO VALLEY AND UPPER
LEVEL RIDGING ALOFT IS PROVIDING CLEAR SKIES ACROSS THE
COMMONWEALTH. THE COLDER VALLEY LOCATIONS HAVE ALREADY DROPPED OFF
INTO THE UPPER 30S...WHILE BROADER VALLEYS REMAIN IN THE LOW TO
MID 40S...AND RIDGES MILDER STILL IN THE UPPER 40S. THE FORECAST
REMAINS ON TRACK...WITH AREAS OF DENSE VALLEY FOG LIKELY TO FORM
THROUGH THE OVERNIGHT. GIVEN THAT THE SURFACE HIGH WILL BE
SHIFTING FURTHER TO THE EAST TONIGHT...ALLOWING WINDS TO VEER
AROUND MORE TO THE SOUTHEAST...WILL MAINTAIN KEEPING THE DENSE
FOG ALONG THE DEEPER RIVER VALLEYS. DID MAKE A FEW TWEAKS TO THE
LOW TEMPERATURES BASED ON THE CURRENT TRENDS IN THE OBSERVATIONS.
UPDATES WILL BE OUT SHORTLY.
UPDATE ISSUED AT 713 PM EST TUE DEC 15 2015
SHELTERED VALLEYS HAVE DROPPED OFF INTO THE LOWER TO MID 40S THUS
FAR TONIGHT. THIS IS ON TRACK WITH THE CURRENT FORECAST LOWS IN
THE LOW TO MID 30S...WITH SOME AREAS OF DENSE FORMING. MAINLY
ADJUSTED THE HOURLY TEMPERATURES TO GET THEM BACK IN LINE WITH THE
DROP OFF THROUGH THE EVENING...OTHERWISE NO OTHER UPDATES ARE
PLANNED AT THIS TIME.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 247 PM EST TUE DEC 15 2015
LAST OF THE CLOUDS NOW BREAKING UP NORTH OF I-64...SETTING UP
CLEAR SKIES FOR TONIGHT. THIS CLEARING AND A RIDGE SPREADING IN
OVERHEAD SHOULD ALLOW FOR EXCELLENT RADIATIONAL COOLING TONIGHT
WITH VALLEYS FALLING INTO THE LOW TO MID 30S TONIGHT. WITH CROSS
OVER TEMPERATURES SITTING AROUND 40...THIS SETS UP A GOOD
POTENTIAL FOR DENSE VALLEY FOG TONIGHT. THUS...WILL GO AHEAD AND
GO WITH A SPECIAL WEATHER STATEMENT TO COVER THE FOG THREAT LATE
TONIGHT THROUGH WEDNESDAY MORNING. FOG WON`T BE QUICK TO BURN OFF
WITH THE LOWER SUN ANGLE THIS TIME OF YEAR...SO PLAN TO LINGER FOG
IN THE VALLEYS UNTIL AT LEAST 10 AM. SOME FOG COULD LINGER EVEN
PAST 10. AFTER FOG DOES BURN OFF...WE SHOULD SEE ANOTHER MILD DAY
WITH HIGHS BACK INTO THE 60S. WENT CLOSER TO THE MET GUIDANCE IN
THE MID 60S FOR HIGHS AS THE LOW SUN ANGLE AND EARLY MORNING FOG
WILL MAKE IT HARD TO REACH THE MAV NUMBERS CLOSER TO 70. THIS WILL
ALSO MAKE IT DIFFICULT TO REACH OUR RECORD HIGHS TOMORROW...BUT
STILL NOT OUT OF THE QUESTION.
TOMORROW NIGHT...A COLD FRONT WILL PUSH INTO THE OHIO RIVER
VALLEY...AS A POTENT SHORTWAVE PUSHES NORTH OUT OF THE DEEP SOUTH.
THIS WAVE WILL BRING GULF MOISTURE NORTHWARD...LEADING TO
WIDESPREAD SHOWER ACTIVITY THROUGH MUCH OF THE NIGHT. IT APPEARS
RAINFALL WILL HOLD OFF UNTIL WELL AFTER SUNSET. WILL MAINTAIN AND
EXPAND THE CATEGORICAL RAIN CHANCES BACK THE NORTHWEST AS MOST
AREAS WILL SEE RAINFALL FROM THIS SYSTEM. THERE IS A SLIGHT CHANCE
A THUNDERSTORM COULD MAKE IT CLOSE TO THE VIRGINIA/KENTUCKY STATE
LINE...BUT OPTED TO LEAVE THE THUNDER OUT OF THE FORECAST. AS FAR
AS RAINFALL GOES...LOOKS LIKE ABOUT A HALF INCH IN THE SOUTHEAST
TO JUST UNDER A QUARTER OF AN INCH IN THE NORTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 PM EST TUE DEC 15 2015
THE PERIOD IS EXPECTED TO BEGIN WITH RIDGING OVER THE ATLANTIC AND
A RIDGE EXTENDING INTO THE DESERT SOUTHWEST AND PARTS OF THE
EASTERN CONUS WITH A TROUGH EXTENDING SOUTH FROM CENTRAL CANADA
INTO THE PLAINS. A LEAD SHORTWAVE WORKING THROUGH THIS TROUGH IS
EXPECTED TO BE MOVING INTO THE OH VALLEY TO START THE PERIOD. AT
THE SFC...AN AREA OF LOW PRESSURE IS EXPECTED TO BE MOVING THROUGH
ONTARIO WITH A COLD FRONT BECOMING STATIONARY TO A WAVE OF LOW
PRESSURE OVER THE SOUTHERN APPALACHIANS.
FROM THURSDAY INTO FRIDAY...THE LEAD SHORTWAVE WILL WORK ACROSS
THE AREA EARLY IN THE PERIOD ON THURSDAY WITH THE SFC WAVE
TRACKING INTO THE NORTHEAST WITH THE TRAILING COLD FRONT SWEEPING
TO THE EASTERN SEABOARD. MEANWHILE...THE MAIN TROUGH AXIS WILL
MOVE INTO THE EASTERN CONS ON THU NIGHT AND THEN MOVE ACROSS
COMMONWEALTH FRI INTO FRIDAY NIGHT. THIS TROUGH WILL USHER IN AN
AIR MASS AS COLD IF NOT SLIGHTLY COLDER THAN THE ONE THAT
AFFECTED THE AREA AROUND NOVEMBER 22ND TO 23RD. HOWEVER...THIS
COLDER AIR MASS WILL BE SHORT LIVED AS HEIGHTS WILL RISE OVER THE
WEEKEND AS RIDGING BUILDS FROM THE GULF OF MEXICO TOWARD BERMUDA
AND ACROSS THE SOUTHEAST. AT THE SAME TIME...A BROAD TROUGH WILL
SPREAD ACROSS MUCH OF THE WESTERN US TO THE PLAINS. THIS SHOULD
BRING MODERATING TEMPERATURES OVER THE WEEKEND...WITH ABOVE NORMAL
TEMPERATURES RETURNING ON SUNDAY. BY THE END OF THE PERIOD... THE
AXIS OF A BROAD TROUGH IS EXPECTED TO EXTEND THROUGH THE PLAINS
WITH A RIDGE CENTERED NEAR BERMUDA AND ANOTHER RIDGE OVER THE
PACIFIC. AS THE TROUGH MOVES EAST TO END THE WEEKEND AND EARLY
NEXT WEEK...A CORRESPONDING SFC LOW SHOULD TRACK TO THE NORTHWEST
OF THE AREA... WHILE RETURN MOISTURE SPREADS NORTH INTO THE MS AND
OH VALLEYS. THIS MILD AND MOIST SOUTHWEST FLOW PATTERN SHOULD
LINGER INTO THE MIDDLE OF NEXT WEEK.
AN AREA OF SHOWERS SHOULD LINGER INTO THE START OF THE LONG TERM
PERIOD ACROSS THE SOUTHEASTERN PART OF THE AREA ESPECIALLY. THEN
AS A SHORTWAVE MOVES IN FROM THE WEST AND 850 MB TEMPS COOL
LEADING TO INCREASING LAPSE RATES...ISOLATED TO POSSIBLY
SCATTERED SNOW SHOWERS AND FLURRIES WILL BE POSSIBLE MAINLY ON
FRIDAY. THERE REMAINS SOME MODEL DIFFERENCES IN WHEN CHANCES OF
THIS WILL BE BEST THOUGH SOME OF THE GUIDANCE POINTS TOWARD MIDDAY
INTO THE AFTERNOON WHICH WOULD ALSO CORRESPOND TO PEAK HEATING.
WITH COLD ADVECTION ANTICIPATED...THE NEW 12Z EC BASED MOS
GUIDANCE APPEAR MORE REASONABLE THAN THE 12Z MEX MOS OR SUPERBLEND
HIGHS FOR FRIDAY. FOR FRIDAY...HELD MAX T IN THE 30S. EVEN WITH
SFC TEMPERATURES POSSIBLY ABOVE FREEZING...FORECAST NEARLY DRY
ADIABATIC LAPSE RATES AND RATHER DRY SUB CLOUD LAYER SHOULD LEAD
TO ANYTHING THAT DOES FALL ON FRIDAY TO FALL AS SNOW.
THE COLDEST NIGHT OF THE LONG TERM PERIOD SHOULD BE ON SAT NIGHT
AS SFC AND UPPER LEVEL RIDGING BUILD ACROSS THE AREA. FOR THIS
PERIOD WE HAVE OPTED TO UNDERCUT THE SUPERBLEND GUIDANCE AND WENT
MORE IN LINE WITH COOP MOS GUIDANCE FOR LOWS IN VALLEYS ON SAT
NIGHT...WHERE TEENS WILL BE POSSIBLE. ABOVE NORMAL TEMPERATURES
ARE EXPECTED BY THE END OF THE WEEKEND AND CONTINUING INTO THE
FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1221 PM EST TUE DEC 15 2015
LOOKS LIKE THE GENERALLY BROAD AND WEAK HIGH IS CENTERED ACROSS
WEST VA TONIGHT. MOST OF THE VALLEY LOCATIONS HAVE
DECOUPLED...PARTICULARLY THE DEEPER ONES. WHILE THE RIDGE LIKE
LOCATIONS REMAIN WELL MIXED AT THIS POINT. THAT SAID THE BEST
CHANCES OF SEEING DENSE FOG WILL CONTINUE TO BE IN VALLEY LOCALES
AND SITE SME STANDS TO HAVE THE BEST CHANCE OF RESTRICTIONS DUE TO
FOG. RIGHT NOW WILL KEEP WITH PREVIOUS FORECAST OF MVFR BASED OFF
LAMP GUIDANCE AND LAMP PROBABILITIES. OTHER SITES SHOULD REMAIN
VFR THROUGH THE NIGHT...BUT WILL MONITOR FOR POTENTIAL ADVECTION
INTO SOME OF THE SITES FROM FROM THE VALLEYS. DID BRING A STRATUS
DECK TOWARD THE END OF THE PERIOD AS ANOTHER COLD FRONT AND UPPER
LEVEL DISTURBANCE APPROACH. WINDS WILL REMAIN LIGHT THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...KAS
LONG TERM...JP
AVIATION...DJ
Area Forecast Discussion
National Weather Service Louisville KY
1219 AM EST WED DEC 16 2015
...Updated Aviation Discussion...
...Forecast Update...
Updated 925 PM EST Tue Dec 15 2015
Made a few minor forecast changes this evening. First of all, temps
have dropped across southern Indiana and northern Kentucky a little
bit more than previously forecast so will lower mins for tonight in
that area. Overall mins should range from the lower 30s to lower
40s.
Also added an area of patchy dense fog just before sunrise over the
Lake Cumberland region. Both the NAM and HRRR are picking up on
better conditions for some patchy dense fog in that region
especially in the valley locations.
.SHORT TERM (Now through Wednesday Night)...
Issued at 245 PM EST Tue Dec 15 2015
Cloud trends this evening, fog potential overnight and shower
chances Wednesday are the main forecast challenges in the short
term.
As of mid-afternoon, water vapor imagery and 500 mb heights showed
the lower Ohio Valley under a weak ridge, between two closed lows
over the CONUS. At the surface, high pressure axis was from north FL
through lower MI. A 50-100 mb thick stratus deck trapped around 2-3
kft has been slowly eroding and lifting northward thanks to
increasing south winds and daytime mixing. Temperatures were in the
50s.
Using visible satellite trends and the HRRR cloud fields, expecting
back edge of the cloud deck to continue work its way northward,
reaching our southern Indiana counties by sunset. The limited mixing
today coupled with light winds right at the surface and high
pressure overhead will promote patchy to areas of fog to develop
across the area overnight through early morning hours. The SREF
probabilities and hi-res model visibility plots show the highest
threat to be across the Lake Cumberland to Bluegrass regions,
especially in the river valleys and other typical fog prone areas.
The main limiting factor for dense fog looks to be increasing
south/southwest winds just off the deck overnight that could keep
the boundary layer mixed enough. Otherwise, plan on lows in the
upper 30s to mid 40s.
A surface low will track from the central Plains to the Upper
Midwest overnight into Wednesday. A moisture-limited cold front will
cross the forecast area late tomorrow morning into the afternoon
hours. Dynamics aren`t impressive and moisture transport is narrow
as it crosses the region, so continued to keep shower chances in the
20-40 percent range, mostly in the afternoon hours. We should warm
up nicely ahead of this system, topping out in the low to mid 60s
with steady south winds 10-20 mph.
.LONG TERM (Thursday through Tuesday)...
Issued at 250 PM EST Tue Dec 15 2015
Wednesday Night - Thursday
The cold front will slow down Wednesday night as it crosses the
region, stalling somewhat over eastern Kentucky while a southern
stream impulse lifts more moisture back to the north. More
widespread rain will then overspread east of I-65, especially along
the I-75 corridor through the Thursday morning commute. Plan on lows
to range from the mid 30s west of I-65, to the low/mid 40s along the
I-75 corridor under deeper clouds and rain. Precipitation should
quickly end west to east Thursday morning.
A digging upper trough will bring seasonably cold air into the
region, as seen by crashing 850 mb temperatures throughout the day.
Temperatures won`t rise too much or even remain steady, especially
in our northwest. Highs in the mid 40s to low 50s.
Friday - Friday Night
The bulk of the cold airmass will be overhead during this time frame
as the upper trough axis swings through the lower Great Lakes into
the mid-Atlantic regions. A quick moving shortwave will round the
base of the trough. As the case with these clippers, moisture is
limited but some of that moisture does lie within the dendritic
growth zone /-10 to -15C/. A flurry or sprinkle, depending on
boundary layer temps, is possible across the northern forecast area,
say from Louisville metro and points east/north. Plan on highs in
the mid 30s to low 40s, and lows Friday night solidly in the 20s.
Saturday - Sunday
A dry and seasonable weekend is expected over the region. After a
slow start, temperatures will warm to the low and mid 40s on
Saturday under sunny skies. Surface high pressure moves east by
Saturday night, with light southerly flow returning.
This sets up our typical ridge/valley split nights where eastern
decoupled valleys stay in the low and mid 20s. Elsewhere, mixed
locations will see upper 20s to around 30. Milder conditions return
for Sunday under a steady south flow. Look for highs in the lower
50s.
Monday - Tuesday
A more active weather pattern is looking increasingly likely over
the area next week as a series of impulses lift out of the Plains to
the Great Lakes. Synoptically, a trough out west with ridging over
the east will favor above normal temperatures and chances of rain.
&&
.AVIATION (06Z TAF Update)...
Updated at 1218 AM EST Wed Dec 16 2015
Main forecast concern for the overnight period will be potential for
visibility restrictions in fog at the TAF sites. BWG has already
dropped into the MVFR, and briefly IFR, range. However, near surface
winds are expected to increase through the overnight hours and may
be enough to limit fog from getting too heavy/widespread due to
mixing. So, will mention a period of MVFR/IFR vis, but improve
toward dawn at BWG. LEX will stand the best shot at seeing some
restrictions through sunrise as the stronger near surface winds stay
mainly West.
Otherwise, expect a south wind to increase in magnitude later this
morning, with some gusts up around 20 kts through the afternoon.
Upper sky cover and then eventual lower clouds will filter in this
evening ahead of a cold front. Some rain chances along with
potential for MVFR ceilings will be around later this evening,
although will only mention VCSH at this time.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........AMS
Short Term.....ZT
Long Term......ZT
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1126 PM CST TUE DEC 15 2015
.AVIATION...
VFR CONDITIONS AT THE ONSET WILL BE STEADILY DETERIORATING FROM
SOUTH TO NORTH AS WARM AIR ADVECTION GETS UNDERWAY TO BRING MARINE
LAYER CLOUD DECK AT LOW END MVFR TO IFR LEVELS. ISENTROPIC LIFT
PROCESS RAINFALL TO BECOME RATHER WIDESPREAD AND PERSISTENT FOR
PREVAILING SHRA INCLUSION FOR BETTER PART OF THE TAF VALID PERIOD
ONCE ONSET. 24/RR
&&
.PREV DISCUSSION... /ISSUED 323 PM CST TUE DEC 15 2015/
DISCUSSION...CLEAR SKIES AND LOW RELATIVELY HUMIDITY VALUES TODAY
CAN BE VERY DECEIVING AS WEATHER CONDITIONS 24 HOURS FROM NOW WILL
BE QUITE DIFFERENT. A DEEP TROUGH HAS DROPPED SOUTHEAST FROM THE
PACIFIC NW WITH AN EMBEDDED CLOSED LOW RACING NORTHEAST ACROSS THE
CENTRAL PLAINS. MOISTURE LEVELS WILL BEGIN TO RISE ON OVERNIGHT AS
SFC RIDGE TO THE NORTHEAST BRINGS HAS ALLOWED WINDS BRING THE RETURN
OF ONSHORE FLOW. MODEL SOUNDS INDICATE PRECIP WATER VALUES RISING
FROM BARELY A QUARTER OF AN INCH TODAY TO WELL OVER 1.5 INCHES
MIDDAY WED. A COLD FRONT ASSOCIATED WITH THE UPPER LOW WILL BE
APPROACHING THE TX/LA BORDER EARLY WEDNESDAY MORNING. SHOWERS WILL
BEGIN TO DEVELOP OUT AHEAD OF THE SYSTEM BUT NOT UNTIL EARLY WED
MORNING. THE HRRR SHOWS LIGHT SHOWERS CLOSING IN ON THE CWA FROM THE
WEST AND GULF MAINLY AFTER 06Z TONIGHT...SO HAVE ADJUSTED POPS
ACCORDINGLY WITH SLIGHT CHANCE TO CHANCE ALONG THE COASTAL AREAS AND
LESS THAN ISOLATED FURTHER INLAND. MODELS IN GOOD AGREEMENT THAT THE
FRONT WILL REACH WESTERN PORTIONS OF THE CWA AROUND NOON WEDNESDAY.
NO SIGNIFICANT CHANGES MADE TO POPS FOR WEDNESDAY. PLUME OF MOISTURE
SATURATE THE COLUMN AND LIFT ALONG THE BOUNDARY COMBINED WITH
PRESSURE FALLS WILL PROMOTE WIDESPREAD SHOWER DEVELOPMENT. MODEL
SOUNDINGS SHOWING SLIGHTLY MORE INSTABILITY THAN PREVIOUS RUNS BUT
STILL FAIRLY MEAGER AND ALL ELEVATED. THE INSTABILITY WILL BE
GREATEST ALONG THE COAST IN THE "WARM SECTOR". IF THERE ARE ANY
STRONGER STORMS...IT WILL BE IN THIS REGION. MAIN THREAT WILL BE
STRONG DOWNDRAFT WINDS. THINKING IT WILL BE MORE OF AN SPS DAY
RATHER THAN SVR ONE IF ANY STORMS INTENSIFY.
BACK SIDE OF THE RAIN TO BE COMING ACROSS THE CWA THURSDAY MORNING.
ALTHOUGH THERE MAY STILL BE SHOWERS IMPACTING COASTAL PARISHES AND
COUNTIES OF LA AND MS....THIS ACTIVITY SHOULD BE OFFSHORE BY AROUND
NOON. STRONG HIGH PRESSURE WILL THEN BUILD IN THROUGH THE REST OF
THE WEEK AND MOST OF THE WEEKEND. A MORE SUBSTANTIAL DROP IN TEMPS
EXPECTED WITH THIS BOUNDARY AS THIS TROUGH WILL TRANSFER MORE
CONTINENTAL AIRMASS THAN PREVIOUS. LOOKING LIKE HIGHS IN THE UPPER
50S AND LOWER TO MID 30S FOR NIGHTTIME LOWS ALONG AND NORTH OF I-12
FOR A COUPLE DAYS BEFORE GRADUALLY MODERATING BACK TO CLIMO NORMS
LATE WEEKEND/EARLY NEXT WEEK.
MEFFER
AVIATION...VFR STATUS EXPECTED TO CONTINUE THROUGH 6Z AT ALL
TERMINALS. AFTER THAT LL MOISTURE WILL BEGIN TO INCREASE AND
INCREASE QUICKLY. BY 8/9Z MOST TERMINALS WILL BEGIN TO BE IMPACTED
BY STRATUS WITH CIGS GENERALLY B/T 1200-2500 FT. ALL TERMINALS WILL
BE IN MVFR STATUS DUE TO LOW CIGS BEFORE SUNRISE. IN ADDITION TO THE
LOW CIGS SOME PATCHY LIGHT FOG COULD ALSO DEVELOP IN A FEW LOCATIONS
THOUGH LL WINDS MAY BE JUST STRONG ENOUGH TO KEEP FOG FROM REALLY
DEVELOPING. /CAB/
MARINE... ERLY FLOW IS ALREADY DEVELOPING OVER THE COASTAL WATERS A
LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVERNIGHT TONIGHT AND EARLY
TOMORROW IN THE NWRN GULF. THE SFC LOW WILL TRAVERSE ACROSS THE CWA
TOMORROW AND TOMORROW EVENING BEFORE PUSHING INTO AL OVERNIGHT WED.
AF THAT A COLD FRONT WILL MOVE THROUGH. AHEAD OF THE LOW MODERATE TO
BRIEF STRONG ONSHORE FLOW WILL DEVELOP BUT THE STRONGEST WINDS (20-
25KTS W/HIGHER GUSTS) AND HIGHEST SEAS(5-8FT) WILL BE POST FRONTAL
THU AND ESPECIALLY THU NIGHT AS THE STRONGEST CAA TAKES PLACE. SCY
ADV WILL BE NEEDED BEHIND THE COLD FRONT BUT EXERCISE CAUTION
HEADLINES MAY ONLY BE NEEDED AHEAD OF THE FRONT TOMORROW. /CAB/
DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 53 70 49 62 / 10 80 70 10
BTR 57 72 51 63 / 10 80 60 10
ASD 58 72 58 63 / 20 80 70 10
MSY 62 74 59 63 / 10 80 70 10
GPT 59 70 61 65 / 20 80 80 20
PQL 58 72 63 66 / 20 80 90 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
447 AM EST WED DEC 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 447 AM EST WED DEC 16 2015
WINDS HAVE TURNED SOUTHEASTERLY THROUGH THE LATE EVENING YESTERDAY
AND EARLY MORNING HOURS TODAY AND THAT HAS STARTED TO WARM THE LOWER
LEVELS AS MID 30 DEGREE TEMPERATURES ADVECT INTO THE AREA.
TEMPERATURES AT 4AM ARE ABOVE OUR NORMAL HIGHS FOR THIS TIME OF THE
YEAR AND RANGE FROM THE UPPER 30S ALONG THE LAKE MICHIGAN SHORELINE
TO THE UPPER 20S OVER THE HIGHER TERRAIN OF THE WEST. ABUNDANT
MOISTURE BELOW 875MB ON THE 00Z KAPX SOUNDING AND REMAINING OVER THE
AREA FROM THE MOISTURE OVER THE LAST 24 HOURS HAS CONTINUED TO
PRODUCE CEILINGS BETWEEN 1-2KFT OVER THE AREA. POCKETS OF BETTER
MOISTURE AND AIDED BY 890MB TEMPS OF -5C MOVING OVER THE 8C NORTHERN
LAKE MICHIGAN WATERS HAVE LED TO SOME AREAS OF LAKE ENHANCED SNOW
SHOWERS OVER NORTH CENTRAL AND EASTERN UPPER MICHIGAN LATE YESTERDAY
EVENING AND THROUGH THE MORNING HOURS. WITH THE INDICATED CLOUDS
TEMPS FROM RAP SOUNDINGS...AM A LITTLE SURPRISED THE PRECIP HAS
LARGELY BEEN SNOW ON THE OBS...BUT DID RECEIVE A REPORT FROM
MARQUETTE THAT IT WAS MIXING WITH RAIN/DRIZZLE. WITH MDOT ROAD
SENSORS STILL INDICATING ROAD SURFACE TEMPERATURES IN THE 29 TO 35
DEGREE RANGE...ANY DRIZZLE THAT MIXES IN WILL FREEZE AND COULD LEAD
TO SOME PATCHY SLICK SPOTS ON AREA ROADWAYS.
THE SOUTHEASTERLY WINDS WILL INCREASE THROUGH THE MORNING HOURS AS A
995MB LOW...LOCATED IN NORTHWEST IOWA AT 4AM...LIFTS NORTHEAST
THROUGH EASTERN MINNESOTA THROUGH THE DAY AND REACHES FAR WESTERN
LAKE SUPERIOR EARLY THIS EVENING. THIS LOW WILL CONTINUE NORTH-
NORTHEAST INTO NORTHERN ONTARIO TONIGHT. THE FIRST WAVE OF
PRECIPITATION WILL BE TIED TO FORCING ASSOCIATED WITH THE STRONG
ISENTROPIC ASCENT ON THE 280-290K ISENTROPIC SURFACES. DO SEE A
MARKED THINNING OF THE FORCING ABOVE 290K AND TIED TO THE MID LEVEL
DRY AIR...WHICH WILL LIKELY CUT OUT ICE CRYSTALS OUTSIDE THE MAIN
PRECIP BAND. THUS...EXPECT A VERY BRIEF PERIOD (GENERALLY 2-4 HOURS)
OF STRONGER PRECIPITATION WITH THE FORCING BEFORE THE DEEPER
MOISTURE CUTS BACK OUT AND THE AREA TRANSITIONS BACK TO LOW CLOUDS
AND POSSIBLY DRIZZLE OR RAIN SHOWERS DUE TO THE LACK OF ICE CRYSTALS
(CLOUD WARMER THAN -5C). AS FOR THE PRECIP IN THE MAIN BAND...THERE
IS A WARM NOSE INITIALLY (AROUND 800MB)...BUT MODELS SHOW THIS
COOLING WITH EVAPORATIVE COOLING THIS MORNING. THAT LEADS TO A
NEARLY ISOTHERMAL LAYER AROUND OR JUST ABOVE 0C FROM 800MB TO JUST
ABOVE THE SURFACE (WARMING ABOVE FREEZING WITH SOUTHEASTERLY FLOW)
OVER PORTIONS OF THE CENTRAL CWA.
UNFORTUNATELY...SLIGHT SHIFTS IN THE TEMPERATURES WILL MAKE A HUGE
DIFFERENCE IN THE P-TYPE AND WITH DIFFERENT MODELS SHOWING SOME OF
THOSE SUBTLE DIFFERENCES...CONFIDENCE STILL REMAINS LOW ON THE EXACT
SOLUTION. THUS...HAVE FOLLOWED THE FOLLOWING IDEA. SHOWED A
TRANSITION FROM SNOW AND DRIZZLE EARLY THIS MORNING TO A MIX OF
RAIN/SNOW WITH THE BAND OVER THE CENTRAL U.P. AND INCLUDED SOME
SLEET OVER THE FAR WEST AND NORTH CENTRAL BASED OFF LINGERING COLD
AIR IN THE LOWER LEVELS. ALSO INCLUDED SOME SNOW MENTION FOR THE
COUPLE HOUR PERIOD OVER THE WEST AND KEWEENAW WITHIN THE BAND. AS
THE MAIN PRECIP BAND SLIDES OVER THE EASTERN U.P....EXPECT THERE TO
BE ENOUGH LOW LEVEL WARM AIR TO MELT ANY SNOWFLAKES AND HAVE RAIN
THERE. WITH SURFACE TEMPERATURES WARMING...THINK SNOW ACCUMULATION
WILL BE LIMITED BUT DID SHOW SOME AREAS OVER THE HIGHER TERRAIN IN
THE WEST-CENTRAL U.P. SEEING UP TO A HALF INCH OF SNOW. IF THE
PRECIP ENDS UP BEING ALL SNOW...WON/T BE SURPRISED TO SEE A QUICK 1-
2 INCHES OF SNOW. AS FOR LIQUID EQUIVALENT...HAVE INCREASED AMOUNTS
TOWARDS THE HIGHER RESOLUTION RUNS WHICH SHOW MOST AREAS SEEING
BETWEEN 0.15 AND 0.33 INCH...WITH SLIGHTLY HIGHER AMOUNTS OVER THE
SOUTH CENTRAL. AS FOR TIMING...EXPECT A VERY BRIEF PERIOD OF
STRONGER PRECIP OVER THE FAR WEST BETWEEN 13-16Z...WITH A TRANSITION
TO THE BETTER PRECIP OVER THE CENTRAL FROM 14-18Z AND THE EAST FROM
17-22Z. FINALLY...ALTHOUGH ROAD TEMPERATURES START OFF COLD...MODELS
CONSISTENT ON LOW LEVEL WARM AIR MOVING INTO THE AREA UNDER THE
STRONG LOW LEVEL SOUTHEASTERLY FLOW. THAT SHOULD HELP WARM THE LOWER
LEVELS AND LIMIT THE CONCERNS FOR ANY FREEZING RAIN/DRIZZLE AFTER
MID-LATE MORNING.
BEHIND THAT PRIMARY PRECIP BAND...EXPECT A BRIEF TRANSITION TO VERY
LIGHT RAIN OR DRIZZLE BEFORE ANOTHER PERIOD OF SHOWERS OCCUR IN THE
AFTERNOON AS THE ENERGY WITH THE 500MB LOW SWEEPS NORTH-NORTHEAST
THROUGH THE AREA. WITH LIMITED ICE CRYSTALS IN THE CLOUDS...WOULD
EXPECT THIS PRECIP TO FALL AS RAIN BUT COULD SEE SOME MIXING WITH
SNOW AS COLDER AIR ARRIVES TOWARDS EVENING. THAT TIES INTO THE
FORECAST FOR TONIGHT...WITH THE BEST PRECIP CHANCES OVER THE WESTERN
THIRD OF THE CWA WHERE THE DEEPER MOISTURE IS LOCATED ON THE BACK
SIDE OF THE LOW. THIS PRECIP WILL BE AIDED LATE TONIGHT BY A
SHORTWAVE WRAPPING AROUND THE BACKSIDE OF THE 500MB LOW AND
IMPACTING THE WESTERN U.P.. A LOW LEVEL TROUGH WILL ALSO BE MOVING
THROUGH THE WESTERN U.P. AT THAT TIME...SWITCHING THE LOW LEVEL
WINDS A LITTLE MORE WESTERLY AND ALSO USHERING IN COLDER AIR THAT
WILL PERSIST THROUGH THE START OF THE WEEKEND. WITH THE LATE ARRIVAL
OF THE COLD AIR FOR THE SHORT TERM FORECAST...DON/T EXPECT TOO MUCH
LAKE ENHANCEMENT OVER THE WEST UNTIL VERY LATE IN THE PERIOD AND
MORE INTO THE THURSDAY TIME-FRAME.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 539 PM EST TUE DEC 15 2015
AT 00Z THU...A ROUGHLY 990MB SFC LOW AND CO-LOCATED UPPER LOW WILL
BE OVER WRN LAKE SUPERIOR OR JUST NW OF THE CWA. COLD AIR WILL BE
ADVECTING INTO THE AREA FROM THE SW...WITH 850MB TEMPS NEAR OR BELOW
0C BY 00Z THU AND WELL UNDER 0C BY 06Z THU. THE DRY SLOT WILL KEEP
SIGNIFICANT SNOWFALL AMOUNTS FROM OCCURING WED NIGHT...BUT WILL SEE
AN INCREASE IN LES IN WSW-W WIND SNOWBELTS LATE WED NIGHT THROUGH
THU...BECOMING LIKELY BY THU AFTERNOON AS 850MB TEMPS DROP BELOW
-10C. LES WILL PEAK THU NIGHT INTO FRI AS AN UPPER TROUGH MOVES
THROUGH AND 850MB TEMPS DROP TO AOB -15C. THIS WILL LEAD TO
INVERSION HEIGHTS AROUND 9-10KFT AND LIFT FAVORABLY LOCATED IN THE
DGZ...PROMOTING MODERATE TO POTENTIALLY HEAVY LES. LOW LEVEL WIND
DIRECTIONS REMAIN IN QUESTION...WITH MODEL SOLUTIONS BETWEEN WSW AND
WNW...WHICH MAKES LES POTENTIAL UNCERTAIN FOR EASTERN LES AREAS OF
ERN ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES. ALL MODELS DO SHOW
WINDS TURNING WNW-NW BY LATE FRI EVENING AND LASTING THROUGH MUCH OF
SAT BEFORE A SFC RIDGE MOVES THROUGH. STILL SEEMS THAT 1-2 SNOWFALL
AMOUNTS OF 8 PLUS INCHES IS LIKELY OVER THE W WIND SNOWBELTS. WILL
LIKELY NEED AN ADVISORY FOR THE KEWEENAW PENINSULA AREA AND WILL
CONTINUE TO HIGHLIGHT THE POTENTIAL FOR PLOW-ABLE SNOW IN THE HWO.
THE SNOW IS EXPECTED TO DIMINISH LATE SAT INTO SAT NIGHT AS DRY AIR
WITH A SURFACE RIDGE MOVES INTO THE AREA.
TEMPS LOOK TO WARM AGAIN EARLY TO MIDDLE OF NEXT WEEK...BUT WILL LET
CONSENSUS GUIDANCE POPULATE THAT PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1227 AM EST WED DEC 16 2015
SOUTHEAST WINDS BETWEEN A LOW PRESSURE SYSTEM MOVING FM THE PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY AND HIGH PRESSURE OVER HUDSON
BAY WILL RESULT IN MAINLY MVFR CIGS UNTIL DAYBREAK WITH LGT SNOW OR
POSSIBLE FZDZ. CIGS LOWER TOWARD DAYBREAK...ESPECIALLY AT KSAW...AS
THE LOW REACHES MINNESOTA. A WINTRY MIX OF FZRA...RAIN...AND SLEET
IS EXPECTED AT KIWD LATE TONIGHT INTO WED MORNING WHILE MAINLY
RAIN/SNOW SHOULD OCCUR AT KCMX AND KSAW. EVENTUALLY ENOUGH WARM AIR
MOVES IN TO CHANGE ANY MIXED PRECIP TO RAIN BY THE AFTN. OVERALL FOR
WED...EXPECT IFR TO LOW MVFR CIGS AND VSBY. LIFR CIGS BLO 500 FT
SHOULD OCCUR AT KSAW LATER WED AFTN DUE TO PERSISTENT UPSLOPE SE
WINDS. CONDITIONS SLOWLY IMPROVE ON WED EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EST WED DEC 16 2015
A LOW PRESSURE SYSTEM LIFTING FROM NORTHWEST IOWA TO FAR WESTERN
LAKE SUPERIOR TODAY WILL LEAD TO SOUTHEASTERLY GALES TO 35-40KTS
OVER PORTIONS OF LAKE SUPERIOR TODAY. WINDS WILL QUICKLY SHIFT TO
THE SOUTHWEST THIS EVENING AS THE LOW LIFTS TO THE NORTHEAST OF THE
AREA AND EXPECT ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE
SOUTHWESTERN HALF OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING.
HAVE MADE SOME ADJUSTMENTS TO THE GALE WARNINGS TO EXTEND THEM INTO
THURSDAY NIGHT. ALTHOUGH THERE WILL BE A BRIEF LULL THIS
EVENING...FELT IT WAS BETTER TO KEEP THEM GOING SINCE IT WILL BE A
PROLONGED LOW END GALE EVENT. AS THE LOW BECOMES NEARLY
STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS OF
25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
GALE WARNING FROM 10 AM THIS MORNING TO 9 PM EST THIS EVENING
FOR LSZ251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...TITUS
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1228 AM EST WED DEC 16 2015
.UPDATE...
ISSUED AT 1043 PM EST TUE DEC 15 2015
UPPER LOW OVER NEB CAUSING SNOW FM THE DAKOTAS INTO WESTERN NEB. SFC
LOW IS OVER SCNTRL NEB. SE UPSLOPE FLOW AHEAD OF THE LOW IS LEADING
TO LGT SNOW/FLURRIES OVER HIGHER TERRAIN OF CNTRL UPR MICHIGAN ATTM.
MAY SEE DZ/FZDZ LATER TONIGHT OVER INTERIOR WEST HALF THOUGH WITH
SNOW PTYPE ATTM WITH TEMPS IN MOIST LAYER ONLY FCST TO BE AROUND
-5C...MIGHT JUST END UP SNOW OVER UPSLOPE AREAS OF CNTRL UPR MICHIGAN
IMT TO NEGAUNEE.
MAIN CONCERN IS PTYPE LATE TONIGHT OVER WEST CWA VCNTY OF KIWD.
ISENTROPIC ASCENT AHEAD OF LOW SHOULD LEAD TO LGT PRECIP SPREADING
IN FM SW. SEEING INITIAL SIGNS OF THIS DEVELOPMENT OVER WESTERN IA TO
CNTRL MN. SHOULD BE MORE OF A DZ/FZDZ INITIALLY BUT AS LIFT INCREASES
PER INCREASING DEEP LAYER Q-VECTOR CONVERGENCE THERE WILL BE ENOUGH
DEEP MOISTURE TO INTRO ICE ALOFT...LEADING TO STEADIER PRECIP. RAP
AND NAM INDICATE WARM NOSE AT H85 AS WARM AS +4C WHICH MAKES SENSE
BASED ON SHARP WARMING IN H85 LAYER SEEN ON 00Z MPX SOUNDING.
THUS...EXPECT PTYPE TO BE LIQUID OR POSSIBLY SLEET LATE TONIGHT AT
KIWD DUE TO COOLING BLO THE WARM NOSE TO THE SFC. AS BLYR WINDS TURN
MORE SE...EXPECT AIRMASS CURRENTLY OVER LK MICHIGAN/EASTERN WI/LOWER
MICHIGAN TO ADVECT IN...PUSHING SFC TEMPS ABOVE FREEZING. ALL MODELS
SHOWING THIS AND ONLY TIME WILL TELL IF THEY ARE ON RIGHT TRACK. IF
COOLING IS SLOWER TO DEVELOP...COULD BE A BRIEF PERIOD OF MAINLY FZRA
AT KIWD LATE TONIGHT. EVEN IF AIR TEMPS RISE TO 33-35...ROAD TEMPS CLEAR
OF SNOW MAY BE MORE AROUND 30 BASED ON LATEST READINGS FM MDOT. SHARPEST
WARM AIR INTRUSION IS PRETTY ISOLATED TO WESTERN UPR MICHIGAN THOUGH
AND DO NOT HAVE TO GO MUCH FARTHER NORTH OR EAST FOR STEADIER PRECIP
IN THE MORNING TO LIKELY START AS SNOW/SLEET BEFORE IT CHANGES OVER
TO RAIN BY LATE MORNING.
WAY TOO MUCH UNCERTAINTY IN BOTH EXTENT OF PRECIP AND PTYPE TO ISSUE
A WINTER WEATHER ADVY HEADLINE ATTM. MORE OF A NEAR TERM FORECAST
ISSUE THAT MID SHIFT WILL BE MONITORING. DID RE ISSUE THE SPECIAL
WEATHER STATEMENT AND ALSO HIT UP SOCIAL MEDIA MENTIONING SLIPPERY
CONDITIONS POSSIBLE FOR THE MORNING COMMUTE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE DEC 15 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITHA
A TROUGH IN THE WRN CONUS THROUGH THE ROCKIES INTO THE PLAINS AND A
RIDGE FROM THE SE INTO THE GREAT LAKES. THE MAIN UPSTREAM FEATURE IS
THE MID LEVEL LOW OVER SW NEBRASKA. AT THE SFC...ERLY FLOW PREVAILED
BTWN HIGH PRES OVER NRN ONTARIO AND THE SFC LOW OVER NW KS. DRIER
AIR FROM EAST OF LAKE SUPERIOR HAS HELPED SCOUR OUT THE LOWER CLOUDS
OVER THE ERN CWA AND HAS HELPED BRING AN END TO THE UPSLOPE LES INTO
N CNTRL UPPER MI.
TONIGHT...AS THE CNTRL PLAINS LOW LIFTS NE TO NEAR NW IA...SE LOW
LEVEL FLOW WILL INCREASE ACROSS THE CWA. THE COMBINATION OF 285K-
290K ISENTROPIC LIFT AND LOW LEVEL MOIST FLOW OFF OF LAKE MI WILL
SUPPORT INCREASING PCPN CHANCES LATE TONIGHT. WITH THE MOIST LAYER
EXTENDING ONLY TO AROUND -5C...MAINLY DZ/FZDZ IS EXPECTED. TEMPS
CLIMBING ABOVE FREEZING LATE TONIGHT SHOULD HELP MINIMIZE POTENTIAL
FOR FREEZING PCPN.
WEDNESDAY...AS THE MID LEVEL MOVES THROUGH CNTRL MN...A PERIOD OF
MODERATE TO STRONG 700-300 MB QVECTOR CONV WITH A BAND OF DEEPER
MOISTURE WILL SUPPORT LIKELY POPS ACROSS THROUGH THE AREA BTWN 15Z-
21Z. TEMPS IN THE ANTECDENT MID LEVEL DRY LAYER WILL DROP ENOUGH
WITH EVAPORATIVE COOLING TO SUPPORT SNOW. HOWEVER...EXPECT A DEEP
ENOUGH SFC WARM LAYER FOR MAINLY RAIN OVER MOST OF THE CWA EXCEPT
THE HIGHER TERRAIN IN THE WEST HALF. EVEN WITH QPF IN THE 0.15 TO
0.25 INCH RANGE...THE WARM SFC CONDITIONS IN THE MID 30S SHOULD
LIMIT ANY ACCUMULATIONS TO LESS THAN AN INCH. THE PCPN MAY REVERT
BACK TO DRIZZLE AS THE DEEPER MOISTURE MOVES OUT FROM WEST TO EAST
LATER IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 539 PM EST TUE DEC 15 2015
AT 00Z THU...A ROUGHLY 990MB SFC LOW AND CO-LOCATED UPPER LOW WILL
BE OVER WRN LAKE SUPERIOR OR JUST NW OF THE CWA. COLD AIR WILL BE
ADVECTING INTO THE AREA FROM THE SW...WITH 850MB TEMPS NEAR OR BELOW
0C BY 00Z THU AND WELL UNDER 0C BY 06Z THU. THE DRY SLOT WILL KEEP
SIGNIFICANT SNOWFALL AMOUNTS FROM OCCURING WED NIGHT...BUT WILL SEE
AN INCREASE IN LES IN WSW-W WIND SNOWBELTS LATE WED NIGHT THROUGH
THU...BECOMING LIKELY BY THU AFTERNOON AS 850MB TEMPS DROP BELOW
-10C. LES WILL PEAK THU NIGHT INTO FRI AS AN UPPER TROUGH MOVES
THROUGH AND 850MB TEMPS DROP TO AOB -15C. THIS WILL LEAD TO
INVERSION HEIGHTS AROUND 9-10KFT AND LIFT FAVORABLY LOCATED IN THE
DGZ...PROMOTING MODERATE TO POTENTIALLY HEAVY LES. LOW LEVEL WIND
DIRECTIONS REMAIN IN QUESTION...WITH MODEL SOLUTIONS BETWEEN WSW AND
WNW...WHICH MAKES LES POTENTIAL UNCERTAIN FOR EASTERN LES AREAS OF
ERN ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES. ALL MODELS DO SHOW
WINDS TURNING WNW-NW BY LATE FRI EVENING AND LASTING THROUGH MUCH OF
SAT BEFORE A SFC RIDGE MOVES THROUGH. STILL SEEMS THAT 1-2 SNOWFALL
AMOUNTS OF 8 PLUS INCHES IS LIKELY OVER THE W WIND SNOWBELTS. WILL
LIKELY NEED AN ADVISORY FOR THE KEWEENAW PENINSULA AREA AND WILL
CONTINUE TO HIGHLIGHT THE POTENTIAL FOR PLOW-ABLE SNOW IN THE HWO.
THE SNOW IS EXPECTED TO DIMINISH LATE SAT INTO SAT NIGHT AS DRY AIR
WITH A SURFACE RIDGE MOVES INTO THE AREA.
TEMPS LOOK TO WARM AGAIN EARLY TO MIDDLE OF NEXT WEEK...BUT WILL LET
CONSENSUS GUIDANCE POPULATE THAT PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1227 AM EST WED DEC 16 2015
SOUTHEAST WINDS BETWEEN A LOW PRESSURE SYSTEM MOVING FM THE PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY AND HIGH PRESSURE OVER HUDSON
BAY WILL RESULT IN MAINLY MVFR CIGS UNTIL DAYBREAK WITH LGT SNOW OR
POSSIBLE FZDZ. CIGS LOWER TOWARD DAYBREAK...ESPECIALLY AT KSAW...AS
THE LOW REACHES MINNESOTA. A WINTRY MIX OF FZRA...RAIN...AND SLEET
IS EXPECTED AT KIWD LATE TONIGHT INTO WED MORNING WHILE MAINLY
RAIN/SNOW SHOULD OCCUR AT KCMX AND KSAW. EVENTUALLY ENOUGH WARM AIR
MOVES IN TO CHANGE ANY MIXED PRECIP TO RAIN BY THE AFTN. OVERALL FOR
WED...EXPECT IFR TO LOW MVFR CIGS AND VSBY. LIFR CIGS BLO 500 FT
SHOULD OCCUR AT KSAW LATER WED AFTN DUE TO PERSISTENT UPSLOPE SE
WINDS. CONDITIONS SLOWLY IMPROVE ON WED EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE DEC 15 2015
ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP AND SLIDE THROUGH THE UPPER
GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST GALES ARE EXPECTED
OVER THE WEST HALF THIS EVENING INTO WED MORNING AND SOUTHEAST WINDS
WILL REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE
LOW LATE TONIGHT THROUGH WEDNESDAY FOLLOWED BY WESTERLY WINDS
APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON THURSDAY
INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM THIS MORNING TO 9 PM EST THIS EVENING FOR
LSZ267.
GALE WARNING FROM 4 AM EARLY THIS MORNING TO 6 PM EST THIS
EVENING FOR LSZ263>266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ THIS MORNING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLA
MARINE...JLB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1140 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 938 PM CST TUE DEC 15 2015
OTHER THAN CONVECTION THAT FIRED IN EASTERN NEBRASKA AND SOUTHWEST
IOWA EARLIER THIS EVENING...PRECIPITATION HAS BEEN SLOW TO GET
GOING IN ADVISORY AREA OF NORTHEAST NEBRASKA. HOWEVER THAT IS
CHANGING AT LATE EVENING AS CORE OF LOW PRESSURE SYSTEM SPINS FROM
SOUTH CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. STARTING TO SEE
CELLULAR RADAR RETURNS AHEAD OF THE LOW NORTHWEST OF GRAND ISLAND.
SURFACE PRESSURE FALLS...AND RAP FORECASTS...SUGGEST LOW WILL
TRACK NORTHEAST ALONG AN ALBION TO WAYNE LINE BETWEEN 06Z AND 10Z.
STRONG ISENTROPIC UPGLIDE JUST AHEAD OF LOW COMBINED WITH
INSTABILITY UNDER COLD CORE POINTS TO A NARROW BUT POTENT BAND OF
PRECIPITATION JUST TO THE NORTHWEST OF LOW TRACK. WHILE SURFACE
TEMPERATURES REMAIN AT OR ABOVE FREEZING NOW...AND WILL LIKELY
REMAIN NEAR FREEZING THROUGH THE NIGHT...DYNAMIC COOLING IN COLUMN
SHOULD LEAD TO MODERATE BURSTS OF SNOW FROM TIME TO TIME...AND
WILL OVERCOME MELTING TENDENCY AT THE SURFACE. SOME SNOW RATES TO
OUR WEST HAVE BEEN AT OR ABOVE AN INCH PER HOUR...AND COULD SEE
THESE RATES HERE AS WELL. HOWEVER AS SYSTEM BEGINS ACCELERATING TO
THE NORTHEAST...WOULD NOT EXPECT THAT TO OCCUR FOR LONG. THUS OUR
CURRENT TOTALS IN THE 2 TO 4 INCH RANGE STILL SEEM TO BE ON TRACK.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
FORECAST CONCERNS THROUGH WEDNESDAY WILL BE HOW FAR NORTH THE
DRYSLOT MAKES IT...PRECIPITATION TYPE ACROSS THE FORECAST
AREA...ALONG WITH EXTENT OF FREEZING PRECIPITATION...SNOW
ACCUMULATIONS AND GUSTY WINDS RELATED TO THE STORM SYSTEM MOVING
THROUGH THE HIGH PLAINS.
SURFACE LOW PRESSURE WAS LOCATED OVER EASTERN COLORADO THIS MORNING
WITH EASTERLY FLOW...FOG...AND DRIZZLE ACROSS THE FORECAST AREA.
SURFACE TEMPERATURES WERE MOSTLY AT OR ABOVE FREEZING. ON THE EDGE
OF THE PRECIPITATION SHIELD NEAR NELIGH AND ROYAL...THEY PICKED UP A
HALF AN INCH TO 1 INCH OF WET SNOW BETWEEN 4AM AND 7AM...BUT HAD
SWITCHED OVER THE DRIZZLE/FREEZING DRIZZLE.
THE 12Z OAX SOUNDING WAS SATURATED IN THE LOWEST 2500FT WITH 0.36
PWAT. SURFACE TEMPERATURES WERE ABOVE FREEZING...HOWEVER ABOVE
800FT...TEMPERATURES WERE BELOW FREEZING.
THIS AFTERNOON...THERE IS A 45KT H85 WIND MAX MOVING THROUGH WITH
STRONG WARM ADVECTION THIS SHOULD LIFT ONE AREA OF PRECIPITATION
INTO SOUTH DAKOTA.
BY 00Z THIS EVENING...THE SURFACE LOW PRESSURE SYSTEM IS FORECAST TO
BE NEAR THE KANSAS/NEBRASKA BORDER WITH THE CLOSED H5 LOW OVER
CENTRAL NEBRASKA. THE FORECAST AREA THERMAL PROFILE IS STILL
MILD...HOWEVER THE COLD AIR IS PRESENT IN NORTHEAST NEBRASKA. THE
H85 TEMPERATURES ARE FORECAST TO VARY FROM 0 TO -4C IN NORTHEAST
NEBRASKA...WITH MILDER 0 TO +4 DEG C FARTHER SOUTHEAST. THE
-10 DEG C H7 TEMPERATURES ARE PROGRESSING EASTWARD. MEANWHILE...A
DRY SLOT IF WORKING FROM SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
THROUGH 06Z...LAPSE RATES STEEPEN...FRONTOGENESIS INCREASES OVER
NORTHEAST NEBRASKA...AND THE COLD POCKET RESIDES OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA...ALONG WITH THIS AREA
BEING SATURATED...THESE CONDITIONS CONTINUE THROUGH 12Z FOR
NORTHEAST NEBRASKA AS THE STORM SYSTEM/SURFACE LOW TRACKS ACROSS
EAST CENTRAL/NORTHEAST NEBRASKA INTO SOUTHERN MINNESOTA. SPECIFIC
HUMIDITY VALUES ARE 2 TO 3 G/KG...WITH 3 TO 6 HRS FAVORABLE
LIFT/DEEP SATURATION. THE HRRR EXP SHOWS THAT THE SNOW INCREASES
IN NORTHEAST NEBRASKA AFTER 04Z...AND LASTS INTO WEDNESDAY
MORNING. THE RAP IS SUPPORTIVE IN TYING IN DECENT H85 TRANSPORT OF
MOISTURE FROM THE GULF...ACROSS MISSOURI...INTO IOWA...AND IN A
BAND INTO NORTHEAST NEBRASKA. THIS PATTERN SETS THE STAGE FOR A
FRONTOGENETIC BAND OF SNOW TO DEVELOP IN NORTHEAST NEBRASKA
OVERNIGHT.
THE NORTHEAST PART OF THE FORECAST SHOULD BEGIN TO SEE SNOW
DEVELOP WITH LIGHT RAIN...DRIZZLE...FOG FOR THE REST OF THE AREA.
AS THE SURFACE LOW TRACKS NORTHEAST...SHOULD SEE SNOW CONTINUE
ACROSS PARTS OF NORTHEAST NEBRASKA AND MAY BE HEAVY FOR A COUPLE
OF HOURS WITH THE STRONGER FRONTOGENETIC FORCING. THE SNOW
CONTINUES TO WRAP AROUND THE SYSTEM AFTER 09Z AS THE NORTHWEST
WINDS INCREASE...HOWEVER THE STORM QUICKLY LIFTS NORTHEAST.
WILL NEED TO MONITOR THE DEVELOPMENT OF THIS ENHANCED BAND OF SNOW
AS IT MOVES ACROSS CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. DO
INCLUDE 2 TO 4 INCHES OF SNOW IN NORTHEAST NEBRASKA AND HAVE A
WINTER WEATHER ADVISORY FOR THE SNOW AND BLOWING SNOW WITH THE
GUSTY WINDS. DID DISCUSS WITH WWD ABOUT POTENTIAL 6 INCH AMOUNTS.
TOUGH TO PIN DOWN...HOWEVER 4KM WRF/NAM AND OTHER MODELS SHOW
POTENTIAL FOR AN ENHANCED AREA.
TEMPERATURES WILL BE COLD ALOFT...THUS SOME LIGHT SNOW AND
FLURRIES WHEREVER CLOUDS ARE SUPPORTED AS THE COLD AIR ADVECTION
CONTINUES WEDNESDAY AFTERNOON. NORTHWEST WINDS 15 TO 30 MPH...WITH
THE STRONGEST WINDS IN NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
HIGHS IN THE UPPER 20S TO LOWER 30S WEDNESDAY.
CYCLONIC FLOW WITH SOME ADDITIONAL FLURRIES POSSIBLE INTO THURSDAY
DEPENDING ON CLOUD COVER. HIGHS THURSDAY AND FRIDAY SIMILAR TO
WEDNESDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
THE RIDGE OVER THE ROCKIES SHIFTS INTO THE PLAINS FOR SATURDAY.
SUNDAY...A H5 TROUGH OVER THE ROCKIES BREAKS THE RIDGE DOWN...WITH
A FRONT MOVING ACROSS THE FORECAST AREA INTO SUNDAY NIGHT. EC/GFS
ARE MAINLY DRY...HOWEVER THE GFS IS COLDER WITH A LITTLE LIGHT
SNOW POSSIBLE SUNDAY AFTERNOON/SUNDAY NIGHT IN NORTHEAST NEBRASKA.
THE GFS WASHES OUT THE NEXT FRONT MONDAY NIGHT...HOWEVER A FRONT
IN THE AREA COULD GENERATE SOME SHOWERS IN WESTERN IOWA TUESDAY.
TEMPERATURES SATURDAY THROUGH TUESDAY REMAIN ABOVE NORMAL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CST TUE DEC 15 2015
KLNK AND KOMA WERE TEMPORARILY VFR BUT WILL AGAIN DROP INTO THE
MVFR CATEGORY THROUGH THE OVERNIGHT AS A LARGE SFC LOW MOVES
NORTHEAST THROUGH THE AREA. A FEW FLURRIES/LIGHT SNOW IS POSSIBLE
AT KOMA IN AND AROUND 12Z SO DID ADD A BRIEF TEMPO GROUP FOR THIS.
OTHERWISE...SOUTHERLY WINDS WILL BECOME WEST/SOUTHWEST BEFORE
BECOMING NORTHWEST LATE IN THE PERIOD. AT KOFK...SITUATION IS A
BIT MORE COMPLEX WITH IFR TO NEAR LIFR CONDITIONS. PRECIPITATION
WILL BE HEAVIEST THERE OVERNIGHT WITH RAIN CHANGING OVER TO SNOW.
NORTHWEST WINDS WILL GUST TO NEAR 35KTS ON WEDNESDAY AS AREA OF
LOW PRESSURE PASSES BY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR NEZ011-012-
016-017.
IA...NONE.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
221 AM EST WED DEC 16 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TONIGHT AND SLIDE
OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL APPROACH FROM THE
WEST THURSDAY AND CROSS THE AREA FRIDAY. HIGH PRESSURE WILL BUILD
IN FROM THE WEST THIS WEEKEND THEN SLIDE OFFSHORE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 2 AM WEDNESDAY...MAINLY CLEAR SKIES RESULTING WITH
EXCELLENT RADIATIONAL COOLING. STILL EXPECTING OVERNIGHT TEMPS TO
RANGE IN THE LOWER 40S INLAND TO LOWER 50S MOST BEACHES. AS
OVERNIGHT LOWS REACHES DEWPT TEMPS...THE AREA CAN EXPECT PATCHY
FOG TO DEVELOP ESPCLY SRN TIER WHERE HRRR SHOWS BEST FOG THREAT. A
LIGHT NE BREEZE WILL DEVELOP AS HIGH PRES BUILDS IN FROM THE NW
AND THAT SHLD HELP DISSIPATE FOG ESPCLY NRN HALF OF REGION.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
AS OF 230 PM WEDNESDAY...NORTH TO SOUTH ORIENTED HIGH PRESSURE
WILL CONTINUE TO INFLUENCE THE WEATHER WHILE MOVING OFFSHORE.
CLEAR SKIES EXPECTED MOST OF THE DAY WITH INCREASING CLOUDS IN
ADVANCE OF THE NEXT FRONT EXPECTED LATE IN THE DAY. HIGHS WILL
CONTINUE ABOVE NORMAL WITH READINGS IN THE MIDDLE TO UPPER 60S
MOST LOCATIONS WITH A FEW OF THE NORMALLY WARMER LOCATIONS LIKELY
REACHING 70 DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
AS OF 333 PM TUESDAY...
WEDNESDAY NIGHT...THE SURFACE RIDGE OVER THE MID-ATLANTIC WILL
SHIFT EAST OVER NEW ENGLAND WHILE A WARM FRONT LIFTS NORTH
OVERNIGHT. VEERING FLOW ALOFT AND MOISTENING WILL SPELL FOR
INCREASING SHOWER CHANCES OVERNIGHT WITH THE ISENTROPIC LIFT
INCREASING THROUGH THE NIGHT. FIRST PART OF THE EVENING WILL BE
DRY WITH JUST AN INCREASE IN CLOUDS...THEN INCREASING POP TREND
LATE. LIKELY POPS CONFINED TO FAR SOUTHEASTERN AREAS BY SUNRISE.
LOW TEMPS WILL LIKELY BE REALIZED PRIOR TO MIDNIGHT...BEFORE
STEADILY RISING THEREAFTER AS THE WARM FRONT LIFTS NORTH.
THURSDAY THROUGH FRIDAY...A DEEP BROAD UPPER TROUGH AND COLD
FRONT WILL PUSH INTO THE TN VALLEY ON THUR. OUT AHEAD OF IT...RICH
GULF MOISTURE WILL SURGE IN ON STRENGTHENING SRLY LOW LEVEL FLOW.
PW`S INC THROUGH THE DAY TO 1.75-2.00 INCHES BY THUR AFTERNOON...
ABOVE THE CLIMATOLOGICAL MAX FOR MID DECEMBER. LARGE SCALE LIFT
CONTINUES TO INCREASE WITH WIDESPREAD RAIN SHOWERS ESP FOR THE
SECOND HALF OF THE DAY AND ACROSS THE COASTAL PLAIN COUNTIES.
ECM CONTINUES TO BE SLIGHTLY SLOWER AND HAS SUPPORT FROM THE
CMC/NAM SOLN...WITH THE GFS A SLIGHTLY FASTER OUTLIER. CONTINUED
THE BEST CHANCE FOR RAIN THUR NIGHT THEN A SLOW DECREASING TREND
ON FRIDAY. MOST AREAS WILL DRY AFTER NOON ON FRIDAY WITH JUST A
CHANCE REMAINING ON THE OBX. WILL HAVE TO MONITOR FLOOD POTENTIAL
ESP THUR NIGHT DUE TO ANOMALOUSLY HIGH PWATS...DEEP WARM CLOUD
LAYER...AND RELATIVELY SLOW FRONTAL PASSAGE. CONTINUED MENTION OF
THUNDERSTORMS THURSDAY AS MODEST INSTABILITY WITH SLIGHTLY BACKED
SURFACE WINDS WILL BE PRESENT. TEMPS WILL REMAIN VERY WARM AHEAD
OF FRONT AND DESPITE THE CLOUDS AND RAIN WITH HIGHS THURSDAY IN
THE 70S PER MODEL THICKNESSES 1385-1395 METERS.
FRIDAY NIGHT THROUGH MONDAY...STRONG COLD AIR ADVECTION DEVELOPS
BEHIND THE FRONT FRIDAY NIGHT INTO SATURDAY WITH BELOW NORMAL
TEMPS. SW WINDS WILL VEER NW AND STRENGTHEN FRI NIGHT...WITH STRONGEST
WINDS EXPECTED TO OCCUR SATURDAY COINCIDENT TO THE UPPER TROUGH
AXIS MOVING ACROSS THE REGION. LOWS FRIDAY NIGHT NEAR CLIMO IN THE
30S. HIGHS SATURDAY IN THE UPPER 40S/LOWER 50S. SATURDAY NIGHT
SHOULD BE COLDEST NIGHT OF THE PERIOD WITH UPPER 20S/LOW 30S
(MID/UPR 30S OBX). THE COOL SNAP WILL BE SHORT LIVED DUE TO
PROGRESSIVE TROUGH MOVING QUICKLY EAST WITH BUILDING
HEIGHTS/THICKNESSES SUNDAY AND MONDAY. MAX TEMPS BACK TO AROUND
CLIMO WITH MID/UPPER 50S SUNDAY THEN ABOVE CLIMO AGAIN BY MONDAY
WITH 60S.
TUESDAY...THE BEGINNING OF ANOTHER VERY WARM DECEMBER `HEAT` WAVE
BEGINS NEXT WEEK WITH DEEP TROUGH DIGGING ACROSS THE INTERMOUNTAIN
WEST AND LARGE RIDGE AMPLIFYING ACROSS THE EASTERN HALF OF THE
CONUS. 500 MB HT ANOMOLIES PER CMC/ECM/GFS ENSEMBLE MEAN ALL
INDICATING WELL ABOVE NORMAL HTS. DEEP MOISTURE FEED FROM THE GULF
WILL BE PRESENT AS WELL AND COULD BE THE BEGINNING OF A WET
PATTERN ACROSS E NC.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 1240 AM WEDNESDAY...VFR CONDITIONS WILL PREVAIL MOST OF THE
TAF PERIOD...EXCEPT FOR THE NEXT SIX HOURS AS PATCHY FOG IS
EXPECTED TO DEVELOP AS DEWPOINT DEPRESSION NARROW DOWN. HIGH
PRESSURE REMAINS IN CONTROL PRODUCING MAINLY CLEAR SKIES AND CALM
WINDS. THIS WILL ALLOW TEMPS TO APPROACH DEWPTS BUT THINK ANY FOG
WILL BE QUITE PATCHY...ADDED TEMPO IFR (KPGV/KISO) FOR INLAND TAF
SITES AND MVFR FOR COASTAL SITES (KEWN/KOAJ).
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 333 PM TUESDAY...INCREASING CLOUDS AND SHOWER CHANCES WED
NIGHT WITH LOWERING CIGS TO POSSIBLY SUB VFR BY LATE EVENING.
BETTER CHANCES OF SUB- VFR THURSDAY INTO FIRST PART OF FRIDAY
WITH GOOD COVERAGE OF SHOWERS EXPECTED AHEAD OF A STRONG COLD
FRONT. WINDS WILL BE QUITE GUSTY OUT OF THE SOUTH THUR AFTERNOON.
GRADUALLY IMPROVING CONDITIONS EXPECTED FRIDAY AS DEEP MOISTURE
MOVES OFFSHORE AND DRY AIR SURGES IN ON NW WINDS BY FRI AFTERNOON.
VFR SKC EXPECTED SATURDAY AND SUNDAY AS STRONG HIGH PRESSURE
SHIFTS THROUGH THE CAROLINAS.
&&
.MARINE...
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 2 AM WEDNESDAY...NO CHANGE NEEDED AT THIS AS WINDS ARE
BEGINNING TO INCREASE OVER THE NORTHERN WATERS. EXPECTED TO
BECOME NNE 10 TO 15 KTS LATE AS HIGH PRES BUILDS IN FROM NW. SEAS
2 TO 4 FEET OVERNIGHT.
PREV DISC...MODERATE WESTERLY FLOW 15 TO 20 KT CURRENTLY BEING
OBSERVED AT THE BUOYS IN WAKE OF COLD FRONTAL PASSAGE AND BUILDING
HIGH PRESSURE WILL BEGIN TO DIMINISH SLIGHTLY LATE TODAY AND
ESPECIALLY TONIGHT TO 10 TO 15 KT WHILE VEERING TO NORTH AND
NORTHEAST. SEAS OVER THE OUTER CENTRAL WATERS CONTINUE AT 6 FT
THIS AFTERNOON AND MAY HAVE TO EXTEND THE SCA THERE FOR ANOTHER
COUPLE OF HOURS INTO THE EARLY EVENING HOURS OTHERWISE SEAS WILL
BE SUBSIDING TO TO 2 TO 4 FT TONIGHT.
WINDS ARE FORECAST TO CONTINUE TO VEER FROM NORTHERLY TO EASTERLY
10 TO 15 KT AS HIGH PRESSURE MOVES OFF OF THE COAST. SEAS ARE
FORECAST TO REMAIN 2-4 FT.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 333 PM TUESDAY...SEAS 2-3 FEET WEDNESDAY NIGHT...WITH
EASTERLY WINDS 5-10 KT IN THE EVENING VEERING SOUTHEAST AND INC
10-15 KT LATE AS A WARM FRONT LIFTS THROUGH THE WATERS. SOUTHERLY
GRADIENT INCREASES ON THURSDAY WITH WINDS INC TO 15-25
KT...HIGHEST ON THE OUTER SOUTHERN/CENTRAL WATERS. A SCA WILL
LIKELY BE NEEDED...POSSIBLY FOR THE NORTHERN WATERS AND PAMLICO
SOUND AS WELL. A SLIGHT DECREASE IN WINDS/SEAS EXPECTED EARLY
FRIDAY AND MAY SEE CONDITIONS BRIEFLY DROP BELOW SCA CRITERIA.
COLD FRONT WILL PASS THROUGH THE WATERS FRI AFTERNOON WITH WINDS
VEERING NW. STRONG CAA FRI NIGHT INTO FIRST PART OF SAT WITH WINDS
INC TO 20-30 KT. SCA WILL LIKELY BE NEEDED FOR ALL WATERS AS WELL
AS THE SOUNDS. HIGH PRES BUILDS IN SAT NIGHT AND SHIFTS OFFSHORE
SUNDAY WITH WINDS/SEAS DIMINISHING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JME
NEAR TERM...RF/BM
SHORT TERM...JME
LONG TERM...TL
AVIATION...TL/BM
MARINE...RF/JME/TL/BM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1148 PM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 1148 PM CST TUE DEC 15 2015
LATEST LOCAL RADAR SHOWING FINGERS/BANDS OF MODERATE TO HEAVY
SNOW ASSOCIATED WITH THE TROWAL IN CONCERT WITH STRONG
FRONTOGENETICAL FORCING/MAXIMUM ASCENT WITHIN THE DENDRITIC
GROWTH ZONE ACROSS SOUTH CENTRAL NORTH DAKOTA. THE RAP13 HEAVY
BANDED SNOW DEPICTS THIS AND BRINGS THE STRONGEST BAND THROUGH
BISMARCK BETWEEN 09Z-10Z. LATEST INDICATIONS ARE THAT THE H7-H5
THETA-E RIDGE AXIS/TROWAL FEATURE WILL BEGIN TO SHIFT EAST OF
BISMARCK INTO THE JAMES RIVER VALLEY BETWEEN 15Z-18Z WEDNESDAY.
THUS THE IDEA OF SNOW DIMINISHING THROUGH THE MORNING FROM WEST TO
EAST STILL LOOKS ON TRACK.
UPDATE ISSUED AT 943 PM CST TUE DEC 15 2015
SNOW IS RAPIDLY FILLING IN OVER SOUTH CENTRAL ND AND THE JAMES
RIVER VALLEY AS OF 03 UTC AS DEFORMATION INCREASES IN ADVANCE OF
THE NORTHWARD-ADVANCING DRY SLOT OBSERVED OVER EASTER SD. THE 00
UTC NAM AND ALL OF THE HRRR/RAP AND ESRL HRRR SIMULATIONS SINCE
LATE AFTERNOON HAVE SUGGESTED THE AXIS OF HEAVIEST MOISTURE WILL
BE SLIGHTLY WEST OF EARLIER EXPECTATIONS BY ABOUT A COUNTY OR SO.
THAT IS PLAUSIBLE BASED ON UPSTREAM OBSERVATIONS OF THE DRY SLOT.
THEREFORE...WE ADJUSTED TOTAL SNOWFALL AMOUNTS SLIGHTLY WITH THIS
UPDATE TO ADVERTISE THE HEAVIEST AMOUNTS OF 6 TO 10 INCHES IN THE
LINTON...ASHLEY AND STEELE AREAS...WITH A BIT LOWER AMOUNTS FROM
5 TO 8 INCHES IN THE JAMES RIVER VALLEY. MODEL-FORECAST SOUNDINGS
SUGGEST THAT OMEGA WILL BE MAXIMIZED IN THE DENDRITIC GROWTH ZONE
WITHIN THE BAND OF HEAVIEST SNOW...POSSIBLY CAUSING SNOW-TO-LIQUID
RATIOS TO EXCEED 20 TO 1 FOR A TIME IN SPOTS.
WE ARE NOT MAKING ANY CHANGES TO THE ADVISORY/WARNING LAYOUT WITH
THIS UPDATE. HOWEVER...SNOW TOTALS IN BISMARCK COULD VERY WELL BE
ON THE HIGH END OF THE ADVERTISED 4 TO 6 INCH RANGE FOR THE CITY.
MOREOVER...EASTERN PARTS OF BURLEIGH COUNTY WILL LIKELY HAVE MORE
SNOWFALL...AS PLACES LIKE STERLING MAY WIND UP IN THE AXIS OF THE
HEAVIEST SNOW. SINCE THE PRIMARY POPULATION CENTER IS CURRENTLY
EXPECTED TO BE JUST BELOW OR NEAR LOW-END WARNING CRITERIA OF 6
INCHES OF SNOW IN 12 HOURS...WE CHOSE TO LEAVE BURLEIGH COUNTY IN
A WINTER WEATHER ADVISORY FOR NOW...BUT WILL CONTINUE MONITORING
TRENDS.
UPDATE ISSUED AT 642 PM CST TUE DEC 15 2015
WE MADE ANOTHER MINOR UPDATE TO FURTHER REFINE/SLIGHTLY SLOW DOWN
THE RAMP-UP IN THE HOURLY CHANCE OF SNOW ACROSS THE JAMES RIVER
VALLEY IN A COLLABORATIVE EFFORT WITH THE NWS OFFICE IN GRAND
FORKS.
UPDATE ISSUED AT 549 PM CST TUE DEC 15 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE CYCLE OTHER THAN TO USE A
TIME-LAGGED ENSEMBLE OF RECENT HRRR AND WRF-ARW/WRF-NMM MODEL RUNS
TO SLOW THE ADVANCE OF SNOW INTO THE AREA SLIGHTLY. REGARDLESS...A
LARGE AREA OF MODERATE TO HEAVY SNOW IN SD IS LIFTING NORTH AND IS
ON TRACK TO ENTER SOUTHERN ND BY MID TO LATE EVENING. WE DO SEE A
SUBTLE TREND WESTWARD IN THE MOST RECENT HRRR/RAP SIMULATIONS WITH
RESPECT TO THE POSITION OF THE DEFORMATION BAND AND THUS HEAVIEST
SNOW WITH THE INCOMING SYSTEM...WHICH WILL REQUIRE MONITORING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
MAIN ISSUE IN THE SHORT TERM IS THE WINTER STORM. LATEST MODEL
GUIDANCE NOW PLACES THE HEAVIEST SNOW THROUGH THE JAMES RIVER
VALLEY BEGINNING THIS EVENING THROUGH WEDNESDAY. MODEL SOUNDINGS
SUGGEST THIS AREA WILL HAVE A DEEP DENDRITIC GROWTH ZONE OF -10 TO
-20C WITH THE HEAVIEST SNOW IS EXPECTED ROUGHLY BETWEEN MIDNIGHT
NOON WEDNESDAY.
MODELS ALSO SHOW A DEFORMATION ZONE SHOULD FOCUS DEEP LIFT AND
FOCUS THE HEAVIEST SNOW IN THE JAMES RIVER VALLEY.
WINDS WILL NOT BE SUFFICIENT TO CREATE BLOWING/DRIFTING SNOW AS
EXPECT THE CHARACTER OF THE SNOW TO BE A BIT WETTISH.
LIGHT SNOW WITH LITTLE ACCUMULATION IS EXPECTED NORTH CENTRAL AND
NORTHWEST WITH THE SOUTHWEST IN A LOW END ADVISORY AROUND 3 OR 4
INCHES.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 220 PM CST TUE DEC 15 2015
SOME SCATTERED LIGHT SNOW WILL LINGER WEDNESDAY NIGHT...THEN COLD
AIR ARRIVES THURSDAY AND FRIDAY.
HIGH PRESSURE AND COLD AIR ADVECTION WILL PUSH INTO NORTH DAKOTA
THURSDAY AND FRIDAY. TEMPERATURES AROUND ZERO ARE EXPECTED FOR
OVERNIGHT LOWS FRIDAY WITH TEMPERATURES IN THE TEENS FOR HIGHS.
WARM AIR ADVECTION KICKS IN THIS WEEKEND AS LOW PRESSURE DEVELOPS
IN MONTANA AND WINDS SHIFT OUT OF THE SOUTH. TEMPERATURES WILL
LIKELY REBOUND INTO THE 30S ACROSS LOCATIONS WITH MINOR SNOWPACK.
MORE ACTIVE WEATHER IS POSSIBLE NEXT WEEK WITH SEVERAL WAVES
INDICATED BY THE LONG TERM MODELS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1148 PM CST TUE DEC 15 2015
MODERATE TO HEAVY SNOW AT TIMES FOR KBIS/KJMS WITH LIFR/VLIFR
CIGS/VSBYS THROUGH 14Z WEDNESDAY. IFR/MVFR CIGS EXPECTED ELSEWHERE
WITH -SN AT ALL REMAINING TERMINALS EXCEPT KISN. SNOW WILL TAPER
OFF AFTER 18Z KBIS/KMOT/KJMS WITH MVFR CIGS CONTINUING THROUGH THE
REST OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST WEDNESDAY FOR NDZ023-025-036-
037-045>048-050-051.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ WEDNESDAY FOR
NDZ005-013-022-034-035-040>044.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
953 AM CST WED DEC 16 2015
.UPDATE...
ISSUED AT 952 AM CST WED DEC 16 2015
Last of the rain generally confined to areas about I-57 eastward
late this morning. Had a couple stray lightning strikes southwest
of Mattoon around 9 am as well. Guidance from the RAP and HRRR
shows this lingering through about 1 pm, however the latest NAM
Nest tries to fire up a few showers immediately along the front by
mid afternoon. The front is just coming into west central Illinois
with a thin enhanced band of clouds immediately along it. The
front is affiliated with a surface low centered over south
central Minnesota, and should reach I-57 by 2-3 pm. Temperatures
will start falling as early as midday around Galesburg, but will
be slipping in most of the forecast area by 3 pm. A short period
of clearing will take place, but low clouds wrapping around the
low will spread back into the northwestern CWA by mid afternoon.
Updated zones/grids sent to reflect the latest trends.
&&
.SHORT TERM...(Today)
ISSUED AT 326 AM CST WED DEC 16 2015
09z/3am surface map shows 996mb low over northeast Nebraska...with
strong cold front extending southward into Texas. Showers are
currently developing within a channel of warm/moist air well ahead
of the boundary, particularly from eastern Texas northward into
west-central Illinois. Latest radar imagery shows the showers
mainly along/west of the I-55 corridor. There have even been a
few lightning strikes with a few of the showers in the St. Louis
metro area over the past hour. Models continue to show the
showers spreading northeastward this morning, with the entire area
of precip gradually shifting eastward as the front approaches.
Given current radar trends, have bumped PoPs into the likely
category west of I-57 this morning. HRRR/NAM/GFS all show the
showers pushing further east into mainly the eastern KILX CWA by
midday...then into Indiana by mid-afternoon. Once front passes,
skies will become partly to mostly sunny during the afternoon and
temperatures will begin to fall due to strong CAA. Highs in the
lower to middle 50s will be achieved by around midday, followed by
readings dropping back into the 40s across the western CWA during
the afternoon.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 326 AM CST WED DEC 16 2015
Once cold front departs, a period of more typical mid-December
weather will develop from Thursday through Saturday as an upper-
level trough spins over southern Canada into the Great Lakes. A
short-wave currently evident on water vapor imagery over British
Columbia will remain well W/SW of Illinois as it tracks
southeastward into Oklahoma by Thursday evening. As a result, am
expecting cool but dry conditions through the period. Highs will be
in the 30s with overnight lows dropping into the lower to middle
20s. Coldest night will be Friday night when overnight lows dip
into the teens in a few locations.
Once the upper trough passes, a return to a southwesterly flow
pattern will lead to rising temperatures and increasing precip
chances next week. While models are still not in perfect agreement,
it is beginning to look like the best rain chances will materialize
by Tuesday into Wednesday as a slow-moving storm system approaches
from the southwest. As a result, have limited PoP mention to Sunday
night when a weak cold front passes...then again Tuesday/Tuesday
night when the more significant system arrives. Aside from the rain
chances, main weather story will be the warmer conditions with highs
climbing back into the 50s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 533 AM CST WED DEC 16 2015
Band of showers working its way across central Illinois this
morning. The risk of showers should be completely east of the
terminal area by early afternoon. While VFR conditions are
expected for the bulk of the 12Z TAF valid time, brief MVFR or
even IFR conditions are possible under a heavier shower today.
Gusty southerly winds will trend southwesterly from midday into
early afternoon as a strong cold front pushes through the area.
The wind gusts will die off this evening, and some wrap around
cloud cover will begin to spread into the area. At this point,
expect the bulk of these clouds to be VFR, although MVFR CIGs
can`t be ruled out.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
635 AM EST WED DEC 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 447 AM EST WED DEC 16 2015
WINDS HAVE TURNED SOUTHEASTERLY THROUGH THE LATE EVENING YESTERDAY
AND EARLY MORNING HOURS TODAY AND THAT HAS STARTED TO WARM THE LOWER
LEVELS AS MID 30 DEGREE TEMPERATURES ADVECT INTO THE AREA.
TEMPERATURES AT 4AM ARE ABOVE OUR NORMAL HIGHS FOR THIS TIME OF THE
YEAR AND RANGE FROM THE UPPER 30S ALONG THE LAKE MICHIGAN SHORELINE
TO THE UPPER 20S OVER THE HIGHER TERRAIN OF THE WEST. ABUNDANT
MOISTURE BELOW 875MB ON THE 00Z KAPX SOUNDING AND REMAINING OVER THE
AREA FROM THE MOISTURE OVER THE LAST 24 HOURS HAS CONTINUED TO
PRODUCE CEILINGS BETWEEN 1-2KFT OVER THE AREA. POCKETS OF BETTER
MOISTURE AND AIDED BY 890MB TEMPS OF -5C MOVING OVER THE 8C NORTHERN
LAKE MICHIGAN WATERS HAVE LED TO SOME AREAS OF LAKE ENHANCED SNOW
SHOWERS OVER NORTH CENTRAL AND EASTERN UPPER MICHIGAN LATE YESTERDAY
EVENING AND THROUGH THE MORNING HOURS. WITH THE INDICATED CLOUDS
TEMPS FROM RAP SOUNDINGS...AM A LITTLE SURPRISED THE PRECIP HAS
LARGELY BEEN SNOW ON THE OBS...BUT DID RECEIVE A REPORT FROM
MARQUETTE THAT IT WAS MIXING WITH RAIN/DRIZZLE. WITH MDOT ROAD
SENSORS STILL INDICATING ROAD SURFACE TEMPERATURES IN THE 29 TO 35
DEGREE RANGE...ANY DRIZZLE THAT MIXES IN WILL FREEZE AND COULD LEAD
TO SOME PATCHY SLICK SPOTS ON AREA ROADWAYS.
THE SOUTHEASTERLY WINDS WILL INCREASE THROUGH THE MORNING HOURS AS A
995MB LOW...LOCATED IN NORTHWEST IOWA AT 4AM...LIFTS NORTHEAST
THROUGH EASTERN MINNESOTA THROUGH THE DAY AND REACHES FAR WESTERN
LAKE SUPERIOR EARLY THIS EVENING. THIS LOW WILL CONTINUE NORTH-
NORTHEAST INTO NORTHERN ONTARIO TONIGHT. THE FIRST WAVE OF
PRECIPITATION WILL BE TIED TO FORCING ASSOCIATED WITH THE STRONG
ISENTROPIC ASCENT ON THE 280-290K ISENTROPIC SURFACES. DO SEE A
MARKED THINNING OF THE FORCING ABOVE 290K AND TIED TO THE MID LEVEL
DRY AIR...WHICH WILL LIKELY CUT OUT ICE CRYSTALS OUTSIDE THE MAIN
PRECIP BAND. THUS...EXPECT A VERY BRIEF PERIOD (GENERALLY 2-4 HOURS)
OF STRONGER PRECIPITATION WITH THE FORCING BEFORE THE DEEPER
MOISTURE CUTS BACK OUT AND THE AREA TRANSITIONS BACK TO LOW CLOUDS
AND POSSIBLY DRIZZLE OR RAIN SHOWERS DUE TO THE LACK OF ICE CRYSTALS
(CLOUD WARMER THAN -5C). AS FOR THE PRECIP IN THE MAIN BAND...THERE
IS A WARM NOSE INITIALLY (AROUND 800MB)...BUT MODELS SHOW THIS
COOLING WITH EVAPORATIVE COOLING THIS MORNING. THAT LEADS TO A
NEARLY ISOTHERMAL LAYER AROUND OR JUST ABOVE 0C FROM 800MB TO JUST
ABOVE THE SURFACE (WARMING ABOVE FREEZING WITH SOUTHEASTERLY FLOW)
OVER PORTIONS OF THE CENTRAL CWA.
UNFORTUNATELY...SLIGHT SHIFTS IN THE TEMPERATURES WILL MAKE A HUGE
DIFFERENCE IN THE P-TYPE AND WITH DIFFERENT MODELS SHOWING SOME OF
THOSE SUBTLE DIFFERENCES...CONFIDENCE STILL REMAINS LOW ON THE EXACT
SOLUTION. THUS...HAVE FOLLOWED THE FOLLOWING IDEA. SHOWED A
TRANSITION FROM SNOW AND DRIZZLE EARLY THIS MORNING TO A MIX OF
RAIN/SNOW WITH THE BAND OVER THE CENTRAL U.P. AND INCLUDED SOME
SLEET OVER THE FAR WEST AND NORTH CENTRAL BASED OFF LINGERING COLD
AIR IN THE LOWER LEVELS. ALSO INCLUDED SOME SNOW MENTION FOR THE
COUPLE HOUR PERIOD OVER THE WEST AND KEWEENAW WITHIN THE BAND. AS
THE MAIN PRECIP BAND SLIDES OVER THE EASTERN U.P....EXPECT THERE TO
BE ENOUGH LOW LEVEL WARM AIR TO MELT ANY SNOWFLAKES AND HAVE RAIN
THERE. WITH SURFACE TEMPERATURES WARMING...THINK SNOW ACCUMULATION
WILL BE LIMITED BUT DID SHOW SOME AREAS OVER THE HIGHER TERRAIN IN
THE WEST-CENTRAL U.P. SEEING UP TO A HALF INCH OF SNOW. IF THE
PRECIP ENDS UP BEING ALL SNOW...WON/T BE SURPRISED TO SEE A QUICK 1-
2 INCHES OF SNOW. AS FOR LIQUID EQUIVALENT...HAVE INCREASED AMOUNTS
TOWARDS THE HIGHER RESOLUTION RUNS WHICH SHOW MOST AREAS SEEING
BETWEEN 0.15 AND 0.33 INCH...WITH SLIGHTLY HIGHER AMOUNTS OVER THE
SOUTH CENTRAL. AS FOR TIMING...EXPECT A VERY BRIEF PERIOD OF
STRONGER PRECIP OVER THE FAR WEST BETWEEN 13-16Z...WITH A TRANSITION
TO THE BETTER PRECIP OVER THE CENTRAL FROM 14-18Z AND THE EAST FROM
17-22Z. FINALLY...ALTHOUGH ROAD TEMPERATURES START OFF COLD...MODELS
CONSISTENT ON LOW LEVEL WARM AIR MOVING INTO THE AREA UNDER THE
STRONG LOW LEVEL SOUTHEASTERLY FLOW. THAT SHOULD HELP WARM THE LOWER
LEVELS AND LIMIT THE CONCERNS FOR ANY FREEZING RAIN/DRIZZLE AFTER
MID-LATE MORNING.
BEHIND THAT PRIMARY PRECIP BAND...EXPECT A BRIEF TRANSITION TO VERY
LIGHT RAIN OR DRIZZLE BEFORE ANOTHER PERIOD OF SHOWERS OCCUR IN THE
AFTERNOON AS THE ENERGY WITH THE 500MB LOW SWEEPS NORTH-NORTHEAST
THROUGH THE AREA. WITH LIMITED ICE CRYSTALS IN THE CLOUDS...WOULD
EXPECT THIS PRECIP TO FALL AS RAIN BUT COULD SEE SOME MIXING WITH
SNOW AS COLDER AIR ARRIVES TOWARDS EVENING. THAT TIES INTO THE
FORECAST FOR TONIGHT...WITH THE BEST PRECIP CHANCES OVER THE WESTERN
THIRD OF THE CWA WHERE THE DEEPER MOISTURE IS LOCATED ON THE BACK
SIDE OF THE LOW. THIS PRECIP WILL BE AIDED LATE TONIGHT BY A
SHORTWAVE WRAPPING AROUND THE BACKSIDE OF THE 500MB LOW AND
IMPACTING THE WESTERN U.P.. A LOW LEVEL TROUGH WILL ALSO BE MOVING
THROUGH THE WESTERN U.P. AT THAT TIME...SWITCHING THE LOW LEVEL
WINDS A LITTLE MORE WESTERLY AND ALSO USHERING IN COLDER AIR THAT
WILL PERSIST THROUGH THE START OF THE WEEKEND. WITH THE LATE ARRIVAL
OF THE COLD AIR FOR THE SHORT TERM FORECAST...DON/T EXPECT TOO MUCH
LAKE ENHANCEMENT OVER THE WEST UNTIL VERY LATE IN THE PERIOD AND
MORE INTO THE THURSDAY TIME-FRAME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM EST WED DEC 16 2015
CONCERNS FOCUS ON POTENTIAL FOR HEAVY LAKE EFFECT SNOW OVER THE
KEWEENAW PENINSULA THU NIGHT INTO FRI EVENING.
FAIRLY PROGRESSIVE PATTERN FOR LONG TERM WILL START OUT WITH CENTRAL
PLAINS STORM SYSTEM LIFTING NORTH OF LAKE SUPERIOR ON THU AND
LEAVING THE UPPER GREAT LAKES IN A COLD ADVECTION PATTERN WHICH
COULD GENERATE PERIODS OF MODERATE TO POSSIBLY HEAVY LES OVER W-NW
SNOWBELTS OF LAKE SUPERIOR INTO FRI NIGHT. BROAD MID-LVL RIDGING
BUILDING ACROSS THE CENTRAL CONUS WILL THEN LEAD TO BRIEF PERIOD OF
MILD AND GENERALLY QUIET WEATHER FOR THE WEEKEND BEFORE ANOTHER IN A
SERIES OF PLAINS SYSTEMS BRING A CHANCE OF MORE PRECIPITATION FOR
EARLY NEXT WEEK.
THU INTO FRI NIGHT...PER 00Z MODEL CONSENSUS...COLD ADVECTION IN THE
WAKE OF PLAINS SYSTEM LIFTING NORTH OF LAKE SUPERIOR WILL LOWER 850
MB TEMPS DOWN TO AROUND -12C BY THU EVENING...AND TO -16 TO -17C FRI
AFTERNOON AND FRI NIGHT.
MODEL SOUNDINGS SUGGEST A NUMBER OF FACTORS COMING TOGETHER FOR THE
POTENTIAL OF HEAVY LAKE EFFECT SNOWFALL OVER THE KEWEENAW
PENINSULA...ESPECIALLY BEGINNING LATE THU NIGHT AND CONTINUING INTO
FRI EVENING. FIRST OFF...THE HEART OF THE COLDEST 850 MB TEMPS WILL
BE MOVING ACROSS LAKE SUPERIOR AT THIS TIME WHICH WILL GREATLY
INCREASE INSTABILITY. SECONDLY...MODELS HINT THAT A COUPLE OF
SHORTWAVES WILL BE MOVING DOWN FROM SOUTH CENTRAL CANADA WHICH
DEEPEN MOISTURE TO NEAR 350 MB PER FORECAST SOUNDING PROFILES WHILE
LIFTING INVERSIONS AND PROVIDING AN OPPORTUNITY FOR ENHANCEMENT TO
LAKE EFFECT. PLUGGING IN A WESTERN LAKE SUPERIOR TEMP OF 42F YIELDS
IMPRESSIVE LAKE INDUCED CAPE VALUES IN THE 500-600 J/KG RANGE BY
FRIDAY WITH LAKE INDUCED EQUILIBRIUM HEIGHTS OF 10-11 KFT. BEST
MODEL OMEGA/LIFT INTERSECTS DGZ ON FRIDAY WHICH WILL ALSO CONTRIBUTE
TO FAVORABLE SNOW GROWTH. MODELS ALSO INDICATE LAKE INDUCED
TROUGHING WILL ENHANCE LOW-LEVEL CONVERGENCE IN WESTERLY FLOW IN
RESPONSE TO COLDER AIR MOVING ACROSS THE REGION. GIVEN ALL THE
FAVORABLE FACTORS AND GOOD MODEL AGREEMENT HAVE DECIDED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR THU NIGHT INTO FRI EVENING. FEEL FAIRLY
CONFIDENT THAT TOTAL LES ACCUMULATION WILL EXCEED A FOOT IN MANY
PLACES OVER THE KEWEENAW PENINSULA AND POSSIBLY APPROACH 18 INCHES
AT A FEW SPOTS. THE WESTERLY WINDS GUSTING NEAR 35 MPH WILL ALSO
CAUSE CONSIDERABLE BLOWING SNOW AND OCCASIONAL WHITEOUT CONDITIONS
AT TIMES.
WINDS BACKING WSW OVER ERN LAKE SUPERIOR FROM LAKE INDUCED TROUGH
MAY KEEP ANY DOMINANT W-E LES BAND THAT FORMS OFFSHORE OF ERN
COUNTIES OF CWA UNTIL AT LEAST LATE FRI. PASSAGE OF SFC TROUGH LATE
FRI INTO FRI EVENING WILL BEGIN TO VEER WINDS AROUND MORE WNW AND
COULD BRING MODERATE TO HEAVY LES INTO PORTIONS OF ERN ALGER-LUCE
AND POSSIBLY NRN SCHOOLCRAFT AND FOR WEST INTO NORTHERN
ONTONAGON...SRN HOUGHTON AND BARAGA COUNTIES FRI NIGHT INTO EARLY
SAT.
THIS WEEKEND...LINGERING WNW LES SHOULD BEGIN TO WIND DOWN FROM WEST
TO EAST ON SATURDAY AS COLDEST AIR MOVES WELL EAST IN THE AFTERNOON
AND THE HIGH PRESSURE RIDGE BUILDING IN FROM WEST BEGINS TO BACK
WINDS FROM WNW TO WSW LATE IN DAY. SOUNDINGS SHOW THAT INCREASING
SUBSIDENCE AND DRIER AIR WILL BRING INVERSION HEIGHTS BACK DOWN BLO
4KFT LATE IN THE DAY. EXPECT QUIETER/DRIER WEATHER SAT NIGHT INTO
SUNDAY WITH BROAD MID-LVL RIDGE MOVING ACROSS OVER THE AREA.
SUNDAY NIGHT INTO TUESDAY...WEATHER LOOKS TO BECOME MORE ACTIVE
AGAIN FOR SUN NIGHT INTO MONDAY. THE ECMWF HAS BEEN PRETTY
CONSISTENT THE LAST FEW RUNS BRINGING A NEG-TILT MID-LVL TROUGH
ACROSS THE GREAT LAKES REGION. ECMWF INDICATES SFC LOW ORGANIZING
OVER THE CENTRAL PLAINS ON SUNDAY AND THEN LIFTING NE ACROSS NRN
LAKE MI TO THE MACKINAC STRAITS LATE SUN NIGHT INTO MONDAY. THIS
SOLUTION AND FAVORABLE TRACK WOULD LIKELY BRING WIDESPREAD SNOW TO
UPPER MI LATE SUN NIGHT INTO MONDAY WITH THE POTENTIAL FOR POSSIBLE
LAKE ENHANCED SNOW INTO ERN COUNTIES MON MORNING. THE 00Z GFS
MEANWHILE SHOWS A WEAKER SHORTWAVE MOVING THROUGH THE AREA WITH
ASSOC WEAKER SFC LOW TRACKING MORE INTO WEST OR CENTRAL UPPER MI
WHICH WOULD SUGGEST A LIGHTER MIXED PCPN EVENT. THE 00Z CANADIAN
MODEL IS TRENDING TOWARD THE DEEPER ECMWF SOLUTION AND IS ALSO
TRENDING FARTHER EAST WITH SFC LOW ALTHOUGH ITS SFC LOW TRACK
THROUGH SCNTRL AND EASTERN UPPER MI WOULD PROBABLY YIELD RAIN OR A
MIX OF RAIN/SNOW OVER THE EAST HALF. GIVEN THAT THE CANADIAN IS
TRENDING DEEPER AND FARTHER EAST BELIEVE THIS LENDS MORE CREEDENCE
TO THE MORE CONSISTENT ECMWF SOLUTION SO WILL LEAN THAT WAY WITH THE
FORECAST AND TREND TOWARD MOSTLY SNOW WITH A POSSIBLY MIX OF
RAIN/SNOW NEAR LAKE MI AND FAR EASTERN CWA. WOULD EXPECT DRIER
CONDITIONS MONDAY NIGHT INTO TUESDAY AS SYSTEM LIFTS NE OF THE GREAT
LAKES AND WEAK RIDGING BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 635 AM EST WED DEC 16 2015
SOUTHEAST WINDS AHEAD OF A LOW PRESSURE SYSTEM LIFTING NORTHEAST
OUT OF NORTHWESTERN IOWA WILL CONTINUE TO BRING IFR TO LOW END MVFR
CEILINGS THROUGH MUCH OF THE DAY TODAY. INITIALLY THIS
MORNING...THE SOUTHEAST WINDS HAS LED TO UPSLOPE FOG AND LAKE
EFFECT SNOW SHOWERS OFF LAKE MICHIGAN FOR KSAW AND SOME OF THOSE
SHOWERS HAVE OCCASIONALLY MADE IT TO KCMX. EXPECT THAT TO CONTINUE
FOR THE NEXT COUPLE OF HOURS...BUT A MUCH STRONGER WAVE OF
PRECIPITATION WILL MOVE NORTH-NORTHEAST THROUGH THE AREA THIS
MORNING AND EARLY AFTERNOON. EXPECT A MIX OF RAIN/SNOW AND EVEN
SLEET TO OCCUR WITHIN THE BAND. LOWERED VISIBILITIES TO IFR AT
KCMX/KSAW WHERE THERE IS A BETTER CHANCE FOR MORE SNOW AND ALSO FOG
HELP. ONCE THE BAND MOVES THROUGH...WINDS WILL SHIFT AROUND TO THE
SOUTH AND THEN SOUTHWEST THIS EVENING...LEADING TO CEILINGS RISING
INTO THE MVFR CATEGORY. SOME SNOW SHOWERS ARE EXPECTED AT KCMX/KIWD
TONIGHT...WITH LAKE ENHANCEMENT INCREASING THE SNOW INTENSITY LATE
AT KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EST WED DEC 16 2015
A LOW PRESSURE SYSTEM LIFTING FROM NORTHWEST IOWA TO FAR WESTERN
LAKE SUPERIOR TODAY WILL LEAD TO SOUTHEASTERLY GALES TO 35-40KTS
OVER PORTIONS OF LAKE SUPERIOR TODAY. WINDS WILL QUICKLY SHIFT TO
THE SOUTHWEST THIS EVENING AS THE LOW LIFTS TO THE NORTHEAST OF THE
AREA AND EXPECT ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE
SOUTHWESTERN HALF OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING.
HAVE MADE SOME ADJUSTMENTS TO THE GALE WARNINGS TO EXTEND THEM INTO
THURSDAY NIGHT. ALTHOUGH THERE WILL BE A BRIEF LULL THIS
EVENING...FELT IT WAS BETTER TO KEEP THEM GOING SINCE IT WILL BE A
PROLONGED LOW END GALE EVENT. AS THE LOW BECOMES NEARLY
STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS OF
25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
GALE WARNING FROM 10 AM THIS MORNING TO 9 PM EST THIS EVENING
FOR LSZ251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
513 AM EST WED DEC 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 447 AM EST WED DEC 16 2015
WINDS HAVE TURNED SOUTHEASTERLY THROUGH THE LATE EVENING YESTERDAY
AND EARLY MORNING HOURS TODAY AND THAT HAS STARTED TO WARM THE LOWER
LEVELS AS MID 30 DEGREE TEMPERATURES ADVECT INTO THE AREA.
TEMPERATURES AT 4AM ARE ABOVE OUR NORMAL HIGHS FOR THIS TIME OF THE
YEAR AND RANGE FROM THE UPPER 30S ALONG THE LAKE MICHIGAN SHORELINE
TO THE UPPER 20S OVER THE HIGHER TERRAIN OF THE WEST. ABUNDANT
MOISTURE BELOW 875MB ON THE 00Z KAPX SOUNDING AND REMAINING OVER THE
AREA FROM THE MOISTURE OVER THE LAST 24 HOURS HAS CONTINUED TO
PRODUCE CEILINGS BETWEEN 1-2KFT OVER THE AREA. POCKETS OF BETTER
MOISTURE AND AIDED BY 890MB TEMPS OF -5C MOVING OVER THE 8C NORTHERN
LAKE MICHIGAN WATERS HAVE LED TO SOME AREAS OF LAKE ENHANCED SNOW
SHOWERS OVER NORTH CENTRAL AND EASTERN UPPER MICHIGAN LATE YESTERDAY
EVENING AND THROUGH THE MORNING HOURS. WITH THE INDICATED CLOUDS
TEMPS FROM RAP SOUNDINGS...AM A LITTLE SURPRISED THE PRECIP HAS
LARGELY BEEN SNOW ON THE OBS...BUT DID RECEIVE A REPORT FROM
MARQUETTE THAT IT WAS MIXING WITH RAIN/DRIZZLE. WITH MDOT ROAD
SENSORS STILL INDICATING ROAD SURFACE TEMPERATURES IN THE 29 TO 35
DEGREE RANGE...ANY DRIZZLE THAT MIXES IN WILL FREEZE AND COULD LEAD
TO SOME PATCHY SLICK SPOTS ON AREA ROADWAYS.
THE SOUTHEASTERLY WINDS WILL INCREASE THROUGH THE MORNING HOURS AS A
995MB LOW...LOCATED IN NORTHWEST IOWA AT 4AM...LIFTS NORTHEAST
THROUGH EASTERN MINNESOTA THROUGH THE DAY AND REACHES FAR WESTERN
LAKE SUPERIOR EARLY THIS EVENING. THIS LOW WILL CONTINUE NORTH-
NORTHEAST INTO NORTHERN ONTARIO TONIGHT. THE FIRST WAVE OF
PRECIPITATION WILL BE TIED TO FORCING ASSOCIATED WITH THE STRONG
ISENTROPIC ASCENT ON THE 280-290K ISENTROPIC SURFACES. DO SEE A
MARKED THINNING OF THE FORCING ABOVE 290K AND TIED TO THE MID LEVEL
DRY AIR...WHICH WILL LIKELY CUT OUT ICE CRYSTALS OUTSIDE THE MAIN
PRECIP BAND. THUS...EXPECT A VERY BRIEF PERIOD (GENERALLY 2-4 HOURS)
OF STRONGER PRECIPITATION WITH THE FORCING BEFORE THE DEEPER
MOISTURE CUTS BACK OUT AND THE AREA TRANSITIONS BACK TO LOW CLOUDS
AND POSSIBLY DRIZZLE OR RAIN SHOWERS DUE TO THE LACK OF ICE CRYSTALS
(CLOUD WARMER THAN -5C). AS FOR THE PRECIP IN THE MAIN BAND...THERE
IS A WARM NOSE INITIALLY (AROUND 800MB)...BUT MODELS SHOW THIS
COOLING WITH EVAPORATIVE COOLING THIS MORNING. THAT LEADS TO A
NEARLY ISOTHERMAL LAYER AROUND OR JUST ABOVE 0C FROM 800MB TO JUST
ABOVE THE SURFACE (WARMING ABOVE FREEZING WITH SOUTHEASTERLY FLOW)
OVER PORTIONS OF THE CENTRAL CWA.
UNFORTUNATELY...SLIGHT SHIFTS IN THE TEMPERATURES WILL MAKE A HUGE
DIFFERENCE IN THE P-TYPE AND WITH DIFFERENT MODELS SHOWING SOME OF
THOSE SUBTLE DIFFERENCES...CONFIDENCE STILL REMAINS LOW ON THE EXACT
SOLUTION. THUS...HAVE FOLLOWED THE FOLLOWING IDEA. SHOWED A
TRANSITION FROM SNOW AND DRIZZLE EARLY THIS MORNING TO A MIX OF
RAIN/SNOW WITH THE BAND OVER THE CENTRAL U.P. AND INCLUDED SOME
SLEET OVER THE FAR WEST AND NORTH CENTRAL BASED OFF LINGERING COLD
AIR IN THE LOWER LEVELS. ALSO INCLUDED SOME SNOW MENTION FOR THE
COUPLE HOUR PERIOD OVER THE WEST AND KEWEENAW WITHIN THE BAND. AS
THE MAIN PRECIP BAND SLIDES OVER THE EASTERN U.P....EXPECT THERE TO
BE ENOUGH LOW LEVEL WARM AIR TO MELT ANY SNOWFLAKES AND HAVE RAIN
THERE. WITH SURFACE TEMPERATURES WARMING...THINK SNOW ACCUMULATION
WILL BE LIMITED BUT DID SHOW SOME AREAS OVER THE HIGHER TERRAIN IN
THE WEST-CENTRAL U.P. SEEING UP TO A HALF INCH OF SNOW. IF THE
PRECIP ENDS UP BEING ALL SNOW...WON/T BE SURPRISED TO SEE A QUICK 1-
2 INCHES OF SNOW. AS FOR LIQUID EQUIVALENT...HAVE INCREASED AMOUNTS
TOWARDS THE HIGHER RESOLUTION RUNS WHICH SHOW MOST AREAS SEEING
BETWEEN 0.15 AND 0.33 INCH...WITH SLIGHTLY HIGHER AMOUNTS OVER THE
SOUTH CENTRAL. AS FOR TIMING...EXPECT A VERY BRIEF PERIOD OF
STRONGER PRECIP OVER THE FAR WEST BETWEEN 13-16Z...WITH A TRANSITION
TO THE BETTER PRECIP OVER THE CENTRAL FROM 14-18Z AND THE EAST FROM
17-22Z. FINALLY...ALTHOUGH ROAD TEMPERATURES START OFF COLD...MODELS
CONSISTENT ON LOW LEVEL WARM AIR MOVING INTO THE AREA UNDER THE
STRONG LOW LEVEL SOUTHEASTERLY FLOW. THAT SHOULD HELP WARM THE LOWER
LEVELS AND LIMIT THE CONCERNS FOR ANY FREEZING RAIN/DRIZZLE AFTER
MID-LATE MORNING.
BEHIND THAT PRIMARY PRECIP BAND...EXPECT A BRIEF TRANSITION TO VERY
LIGHT RAIN OR DRIZZLE BEFORE ANOTHER PERIOD OF SHOWERS OCCUR IN THE
AFTERNOON AS THE ENERGY WITH THE 500MB LOW SWEEPS NORTH-NORTHEAST
THROUGH THE AREA. WITH LIMITED ICE CRYSTALS IN THE CLOUDS...WOULD
EXPECT THIS PRECIP TO FALL AS RAIN BUT COULD SEE SOME MIXING WITH
SNOW AS COLDER AIR ARRIVES TOWARDS EVENING. THAT TIES INTO THE
FORECAST FOR TONIGHT...WITH THE BEST PRECIP CHANCES OVER THE WESTERN
THIRD OF THE CWA WHERE THE DEEPER MOISTURE IS LOCATED ON THE BACK
SIDE OF THE LOW. THIS PRECIP WILL BE AIDED LATE TONIGHT BY A
SHORTWAVE WRAPPING AROUND THE BACKSIDE OF THE 500MB LOW AND
IMPACTING THE WESTERN U.P.. A LOW LEVEL TROUGH WILL ALSO BE MOVING
THROUGH THE WESTERN U.P. AT THAT TIME...SWITCHING THE LOW LEVEL
WINDS A LITTLE MORE WESTERLY AND ALSO USHERING IN COLDER AIR THAT
WILL PERSIST THROUGH THE START OF THE WEEKEND. WITH THE LATE ARRIVAL
OF THE COLD AIR FOR THE SHORT TERM FORECAST...DON/T EXPECT TOO MUCH
LAKE ENHANCEMENT OVER THE WEST UNTIL VERY LATE IN THE PERIOD AND
MORE INTO THE THURSDAY TIME-FRAME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM EST WED DEC 16 2015
CONCERNS FOCUS ON POTENTIAL FOR HEAVY LAKE EFFECT SNOW OVER THE
KEWEENAW PENINSULA THU NIGHT INTO FRI EVENING.
FAIRLY PROGRESSIVE PATTERN FOR LONG TERM WILL START OUT WITH CENTRAL
PLAINS STORM SYSTEM LIFTING NORTH OF LAKE SUPERIOR ON THU AND
LEAVING THE UPPER GREAT LAKES IN A COLD ADVECTION PATTERN WHICH
COULD GENERATE PERIODS OF MODERATE TO POSSIBLY HEAVY LES OVER W-NW
SNOWBELTS OF LAKE SUPERIOR INTO FRI NIGHT. BROAD MID-LVL RIDGING
BUILDING ACROSS THE CENTRAL CONUS WILL THEN LEAD TO BRIEF PERIOD OF
MILD AND GENERALLY QUIET WEATHER FOR THE WEEKEND BEFORE ANOTHER IN A
SERIES OF PLAINS SYSTEMS BRING A CHANCE OF MORE PRECIPITATION FOR
EARLY NEXT WEEK.
THU INTO FRI NIGHT...PER 00Z MODEL CONSENSUS...COLD ADVECTION IN THE
WAKE OF PLAINS SYSTEM LIFTING NORTH OF LAKE SUPERIOR WILL LOWER 850
MB TEMPS DOWN TO AROUND -12C BY THU EVENING...AND TO -16 TO -17C FRI
AFTERNOON AND FRI NIGHT.
MODEL SOUNDINGS SUGGEST A NUMBER OF FACTORS COMING TOGETHER FOR THE
POTENTIAL OF HEAVY LAKE EFFECT SNOWFALL OVER THE KEWEENAW
PENINSULA...ESPECIALLY BEGINNING LATE THU NIGHT AND CONTINUING INTO
FRI EVENING. FIRST OFF...THE HEART OF THE COLDEST 850 MB TEMPS WILL
BE MOVING ACROSS LAKE SUPERIOR AT THIS TIME WHICH WILL GREATLY
INCREASE INSTABILITY. SECONDLY...MODELS HINT THAT A COUPLE OF
SHORTWAVES WILL BE MOVING DOWN FROM SOUTH CENTRAL CANADA WHICH
DEEPEN MOISTURE TO NEAR 350 MB PER FORECAST SOUNDING PROFILES WHILE
LIFTING INVERSIONS AND PROVIDING AN OPPORTUNITY FOR ENHANCEMENT TO
LAKE EFFECT. PLUGGING IN A WESTERN LAKE SUPERIOR TEMP OF 42F YIELDS
IMPRESSIVE LAKE INDUCED CAPE VALUES IN THE 500-600 J/KG RANGE BY
FRIDAY WITH LAKE INDUCED EQUILIBRIUM HEIGHTS OF 10-11 KFT. BEST
MODEL OMEGA/LIFT INTERSECTS DGZ ON FRIDAY WHICH WILL ALSO CONTRIBUTE
TO FAVORABLE SNOW GROWTH. MODELS ALSO INDICATE LAKE INDUCED
TROUGHING WILL ENHANCE LOW-LEVEL CONVERGENCE IN WESTERLY FLOW IN
RESPONSE TO COLDER AIR MOVING ACROSS THE REGION. GIVEN ALL THE
FAVORABLE FACTORS AND GOOD MODEL AGREEMENT HAVE DECIDED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR THU NIGHT INTO FRI EVENING. FEEL FAIRLY
CONFIDENT THAT TOTAL LES ACCUMULATION WILL EXCEED A FOOT IN MANY
PLACES OVER THE KEWEENAW PENINSULA AND POSSIBLY APPROACH 18 INCHES
AT A FEW SPOTS. THE WESTERLY WINDS GUSTING NEAR 35 MPH WILL ALSO
CAUSE CONSIDERABLE BLOWING SNOW AND OCCASIONAL WHITEOUT CONDITIONS
AT TIMES.
WINDS BACKING WSW OVER ERN LAKE SUPERIOR FROM LAKE INDUCED TROUGH
MAY KEEP ANY DOMINANT W-E LES BAND THAT FORMS OFFSHORE OF ERN
COUNTIES OF CWA UNTIL AT LEAST LATE FRI. PASSAGE OF SFC TROUGH LATE
FRI INTO FRI EVENING WILL BEGIN TO VEER WINDS AROUND MORE WNW AND
COULD BRING MODERATE TO HEAVY LES INTO PORTIONS OF ERN ALGER-LUCE
AND POSSIBLY NRN SCHOOLCRAFT AND FOR WEST INTO NORTHERN
ONTONAGON...SRN HOUGHTON AND BARAGA COUNTIES FRI NIGHT INTO EARLY
SAT.
THIS WEEKEND...LINGERING WNW LES SHOULD BEGIN TO WIND DOWN FROM WEST
TO EAST ON SATURDAY AS COLDEST AIR MOVES WELL EAST IN THE AFTERNOON
AND THE HIGH PRESSURE RIDGE BUILDING IN FROM WEST BEGINS TO BACK
WINDS FROM WNW TO WSW LATE IN DAY. SOUNDINGS SHOW THAT INCREASING
SUBSIDENCE AND DRIER AIR WILL BRING INVERSION HEIGHTS BACK DOWN BLO
4KFT LATE IN THE DAY. EXPECT QUIETER/DRIER WEATHER SAT NIGHT INTO
SUNDAY WITH BROAD MID-LVL RIDGE MOVING ACROSS OVER THE AREA.
SUNDAY NIGHT INTO TUESDAY...WEATHER LOOKS TO BECOME MORE ACTIVE
AGAIN FOR SUN NIGHT INTO MONDAY. THE ECMWF HAS BEEN PRETTY
CONSISTENT THE LAST FEW RUNS BRINGING A NEG-TILT MID-LVL TROUGH
ACROSS THE GREAT LAKES REGION. ECMWF INDICATES SFC LOW ORGANIZING
OVER THE CENTRAL PLAINS ON SUNDAY AND THEN LIFTING NE ACROSS NRN
LAKE MI TO THE MACKINAC STRAITS LATE SUN NIGHT INTO MONDAY. THIS
SOLUTION AND FAVORABLE TRACK WOULD LIKELY BRING WIDESPREAD SNOW TO
UPPER MI LATE SUN NIGHT INTO MONDAY WITH THE POTENTIAL FOR POSSIBLE
LAKE ENHANCED SNOW INTO ERN COUNTIES MON MORNING. THE 00Z GFS
MEANWHILE SHOWS A WEAKER SHORTWAVE MOVING THROUGH THE AREA WITH
ASSOC WEAKER SFC LOW TRACKING MORE INTO WEST OR CENTRAL UPPER MI
WHICH WOULD SUGGEST A LIGHTER MIXED PCPN EVENT. THE 00Z CANADIAN
MODEL IS TRENDING TOWARD THE DEEPER ECMWF SOLUTION AND IS ALSO
TRENDING FARTHER EAST WITH SFC LOW ALTHOUGH ITS SFC LOW TRACK
THROUGH SCNTRL AND EASTERN UPPER MI WOULD PROBABLY YIELD RAIN OR A
MIX OF RAIN/SNOW OVER THE EAST HALF. GIVEN THAT THE CANADIAN IS
TRENDING DEEPER AND FARTHER EAST BELIEVE THIS LENDS MORE CREEDENCE
TO THE MORE CONSISTENT ECMWF SOLUTION SO WILL LEAN THAT WAY WITH THE
FORECAST AND TREND TOWARD MOSTLY SNOW WITH A POSSIBLY MIX OF
RAIN/SNOW NEAR LAKE MI AND FAR EASTERN CWA. WOULD EXPECT DRIER
CONDITIONS MONDAY NIGHT INTO TUESDAY AS SYSTEM LIFTS NE OF THE GREAT
LAKES AND WEAK RIDGING BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1227 AM EST WED DEC 16 2015
SOUTHEAST WINDS BETWEEN A LOW PRESSURE SYSTEM MOVING FM THE PLAINS
TO THE UPPER MISSISSIPPI RIVER VALLEY AND HIGH PRESSURE OVER HUDSON
BAY WILL RESULT IN MAINLY MVFR CIGS UNTIL DAYBREAK WITH LGT SNOW OR
POSSIBLE FZDZ. CIGS LOWER TOWARD DAYBREAK...ESPECIALLY AT KSAW...AS
THE LOW REACHES MINNESOTA. A WINTRY MIX OF FZRA...RAIN...AND SLEET
IS EXPECTED AT KIWD LATE TONIGHT INTO WED MORNING WHILE MAINLY
RAIN/SNOW SHOULD OCCUR AT KCMX AND KSAW. EVENTUALLY ENOUGH WARM AIR
MOVES IN TO CHANGE ANY MIXED PRECIP TO RAIN BY THE AFTN. OVERALL FOR
WED...EXPECT IFR TO LOW MVFR CIGS AND VSBY. LIFR CIGS BLO 500 FT
SHOULD OCCUR AT KSAW LATER WED AFTN DUE TO PERSISTENT UPSLOPE SE
WINDS. CONDITIONS SLOWLY IMPROVE ON WED EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EST WED DEC 16 2015
A LOW PRESSURE SYSTEM LIFTING FROM NORTHWEST IOWA TO FAR WESTERN
LAKE SUPERIOR TODAY WILL LEAD TO SOUTHEASTERLY GALES TO 35-40KTS
OVER PORTIONS OF LAKE SUPERIOR TODAY. WINDS WILL QUICKLY SHIFT TO
THE SOUTHWEST THIS EVENING AS THE LOW LIFTS TO THE NORTHEAST OF THE
AREA AND EXPECT ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE
SOUTHWESTERN HALF OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING.
HAVE MADE SOME ADJUSTMENTS TO THE GALE WARNINGS TO EXTEND THEM INTO
THURSDAY NIGHT. ALTHOUGH THERE WILL BE A BRIEF LULL THIS
EVENING...FELT IT WAS BETTER TO KEEP THEM GOING SINCE IT WILL BE A
PROLONGED LOW END GALE EVENT. AS THE LOW BECOMES NEARLY
STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS OF
25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
GALE WARNING FROM 10 AM THIS MORNING TO 9 PM EST THIS EVENING
FOR LSZ251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS JACKSON MS
757 AM CST WED DEC 16 2015
.UPDATE...MADE AN UPDATE TO ADD FOG AND MENTION OF POSSIBLE DENSE FOG
IN THE HWO/GRAPHICS FOR THIS MORNING. THICK FOG HAS BEEN ADVECTING
NORTHWARD IN THE STRONG WARM ADVECTION REGIME AND VISIBILITIES ARE
DOWN TO A QUARTER MILE AT TIMES WITH THE LATEST HRRR SUGGESTING THIS
WILL LAST THROUGH MID MORNING. BELIEVE THERE SHOULD BE JUST ENOUGH
MIXING WITH HEATING TO KEEP THIS FROM BEING A DENSE FOG EVENT WORTHY
OF AN ADVISORY. /EC/
&&
.PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 16 2015/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...THE PRIMARY FORECAST
CONCERN WILL BE OUR WEATHER TODAY AND THIS EVENING. CURRENT RADARS
SHOW A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING THROUGH
CENTRAL LOUISIANA THIS MORNING ALONG WITH SOME DISCRETE STORMS AHEAD
OF THE LINE. THIS IS LOCATED ALONG/JUST AHEAD OF A COLD FRONT THAT
WILL MOVE THROUGH OUR REGION TODAY. THIS IS IN ASSOCIATION WITH A
LARGE UPPER LOW AND DEEP SFC LOW THAT WILL BOTH TRACK ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY TODAY TOWARD THE GREAT LAKES REGION.
THE COLD FRONT WILL MOVE THROUGH DURING TEH AFTERNOON. MUCH OF THIS
ACTIVITY ENTERING THE DELTA THIS MORNING WILL REMAIN ELEVATED AS
BOUNDARY LAYER REMAINS STABLE WITH NO SFC BASED CAPE AVAILABLE. MID
LEVEL LAPSE RATES ARE DECENT ENOUGH TO WHERE SOME SMALL HAIL COULD
BE POSSIBLE WITH THESE MORNING STORMS BUT OVERALL SHOULD NOT BE A
BIG DEAL OTHER THAN SOME RAIN AND LIGHTNING.
AS THE FRONT CROSSES THE REGION TODAY...MODELS CONTINUE TO AGREE
THAT A WEAK SFC LOW WILL DEVELOP ALONG THE SOUTHERN END. THIS LOW
WILL TRACK NORTHEAST INTO THE GULF COAST...ACROSS MY SOUTHEASTERN
COUNTIES...AND EVENTUALLY INTO ALABAMA. THE OVERALL THINKING REMAINS
THE SAME REGARDING OUR POTENTIAL FOR A FEW STRONG TO SEVERE STORMS.
THE BETTER CHANCES FOR THIS WILL BE IN THE PINE BELT REGION OR
SLIGHTLY NORTH OF THERE LATER THIS AFTERNOON INTO THIS EVENING. HI-
RES MODELS SHOW MORE CELLULAR STORMS DEVELOPING/MOVING NORTH ACROSS
THIS REGION LATE THIS AFTERNOON BEFORE COVERAGE INCREASES AFTER 00Z
TONIGHT. LOW LEVEL SHEAR IS MARGINAL AROUND 20KTS WITH BETTER DEEP
LAYER SHEAR(AROUND 40-50KTS). MORE INSTABILITY IS FORECAST WITH THIS
SYSTEM THAN WAS FORECAST WITH THE LAST SO THIS SHOULD NOT BE AN
ISSUE AS A WARM FRONT MOVES NORTH ACROSS THE AREA...LEAVING THE
SOUTHEAST IN THE WARM SECTOR. JUST HOW FAR NORTH IT GETS WILL BE THE
QUESTION AS TO HOW MUCH OF THE AREA HAS POTENTIAL FOR STRONG TO
SEVERE STORMS. TEMPERATURES IN THE SOUTHEAST SHOULD REACH THE LOWER
70S AHEAD OF THE FRONT DESPITE INCREASING CLOUD COVER. MOST UNSTABLE
CAPE IS BEING ADVERTISED AROUND 700 J/KG WITH THE NAM SHOWING VALUES
OVER 1000J/KG. THE SOUTHEAST IS ALSO WHERE SFC BASED CAPE IS
FORECAST TO BE AROUND 800-1000 J/KG. WILL CONTINUE WITH THE MENTION
OF DAMAGING WIND GUSTS AND A NON-ZERO RISK FOR A TORNADO AS
INGREDIENTS MAY BE JUST ENOUGH...ALONG WITH THE PROXIMITY OF THE
BOUNDARY...FOR THIS TO BE CONSIDERED.
RAIN WILL TAPER OFF FROM WEST TO EAST THROUGH THE NIGHT AND BE CLEAR
OF THE ARKLAMISS BY THURSDAY MORNING. COOLER AIR WILL FILTER INTO
THE REGION BEHIND THE FRONT WITH HIGHS ON THURSDAY IN THE 50S.
OVERNIGHT LOWS FRIDAY MORNING WILL DIP INTO THE 30S AS THE UPPER
TROUGH SWINGS ACROSS THE REGION AND HIGH PRESSURE AT THE SFC BEGINS
TO SLIDE IN. /28/
LONG TERM...FRIDAY THROUGH NEXT TUESDAY...A COOL SEASONABLE AIRMASS
WILL BE OVER THE REGION IN THE WAKE OF THE COLD FRONT WITH AROUND
SEASONABLE TEMPERATURES WITH HIGHS IN THE 50S ON FRIDAY. HIGHS WILL
SLOWLY MODERATE INTO THE LOWER TO MIDDLE 60S BY SUNDAY AFTERNOON.
THIS WILL BE DUE TO SOME BROAD FLAT UPPER RIDGING COMING IN FROM THE
WEST WITH LOW LEVEL RETURN FLOW. AS WE PUSH INTO THE EARLY PART OF
THE WORK WEEK HIGHS WILL BE WELL ABOVE NORMAL WITH READINGS REACHING
THE LOWER 70S. LOWS WILL MODERATE FROM THE LOWER 30S FRIDAY NIGHT TO
THE 40S AND 50S BY SUNDAY NIGHT...THEN WILL WARM INTO THE UPPER 50S
TO AROUND 60S EARLY NEXT WEEK...WHICH IS ALSO WELL ABOVE NORMAL. OUR
CHANCES OF RAIN WILL COME BACK FOR SUNDAY NIGHT INTO EARLY NEXT WEEK.
THIS WILL BE DUE TO A SERIES OF WEAK SHORTWAVES IN SOUTHWEST FLOW
AHEAD OF A STATIONARY FRONT TO THE WEST. INSTABILITY WILL BE RATHER
WEAK.
AS WE LOOK INTO THE REMAINDER OF THE WORK WEEK A BROAD UPPER TROUGH
WILL PUSH A STORM SYSTEM TOWARD THE REGION AS WE NEAR CHRISTMAS
EVE./17/
AVIATION...VFR CATEGORIES WILL CONTINUE AT MOST TAF SITES THIS
MORNING BUT CLOUDS ARE ON THE INCREASE AS MOISTURE INCREASES AHEAD
OF A COLD FRONT. THIS FRONT WILL BRING SHOWERS AND STORMS TO THE AREA
TODAY. KGLH SHOULD SEE STORMS BEFORE 18Z WHILE OTHER SITES MAYBE
LATER...ESPECIALLY KPIB/KHBG/KMEI. LOW STRATUS AND/OR PATCHY FOG IS
MOVING INTO SOUTHERN MISSISSIPPI AS OF 10Z AND WILL LIKELY REDUCE
CEILINGS TO MVFR CATEGORIES THROUGH 15Z. EXPECT FURTHER FLIGHT CAT
DETERIORATION IN A MAJORITY OF THE REGION THROUGH MID TO LATE
MORNING AS SHOWERS AND EMBEDDED STORMS INCREASE. WINDS WILL BE OUT OF
THE SOUTH...LIGHT TO CALM EARLY THIS MORNING BEFORE INCREASING TO
AROUND 10KTS(HIGHER IN THUNDERSTORMS). /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 72 48 56 34 / 62 96 13 3
MERIDIAN 70 49 58 33 / 73 99 13 5
VICKSBURG 70 48 55 35 / 59 49 9 2
HATTIESBURG 75 53 62 36 / 74 94 13 3
NATCHEZ 73 48 57 36 / 63 54 10 2
GREENVILLE 65 40 54 33 / 80 21 4 3
GREENWOOD 66 42 54 32 / 76 46 11 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
JAN/JAN
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1127 AM CST WED DEC 16 2015
.UPDATE...
ISSUED AT 952 AM CST WED DEC 16 2015
Last of the rain generally confined to areas about I-57 eastward
late this morning. Had a couple stray lightning strikes southwest
of Mattoon around 9 am as well. Guidance from the RAP and HRRR
shows this lingering through about 1 pm, however the latest NAM
Nest tries to fire up a few showers immediately along the front by
mid afternoon. The front is just coming into west central Illinois
with a thin enhanced band of clouds immediately along it. The
front is affiliated with a surface low centered over south
central Minnesota, and should reach I-57 by 2-3 pm. Temperatures
will start falling as early as midday around Galesburg, but will
be slipping in most of the forecast area by 3 pm. A short period
of clearing will take place, but low clouds wrapping around the
low will spread back into the northwestern CWA by mid afternoon.
Updated zones/grids sent to reflect the latest trends.
&&
.SHORT TERM...(Today)
ISSUED AT 326 AM CST WED DEC 16 2015
09z/3am surface map shows 996mb low over northeast Nebraska...with
strong cold front extending southward into Texas. Showers are
currently developing within a channel of warm/moist air well ahead
of the boundary, particularly from eastern Texas northward into
west-central Illinois. Latest radar imagery shows the showers
mainly along/west of the I-55 corridor. There have even been a
few lightning strikes with a few of the showers in the St. Louis
metro area over the past hour. Models continue to show the
showers spreading northeastward this morning, with the entire area
of precip gradually shifting eastward as the front approaches.
Given current radar trends, have bumped PoPs into the likely
category west of I-57 this morning. HRRR/NAM/GFS all show the
showers pushing further east into mainly the eastern KILX CWA by
midday...then into Indiana by mid-afternoon. Once front passes,
skies will become partly to mostly sunny during the afternoon and
temperatures will begin to fall due to strong CAA. Highs in the
lower to middle 50s will be achieved by around midday, followed by
readings dropping back into the 40s across the western CWA during
the afternoon.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 326 AM CST WED DEC 16 2015
Once cold front departs, a period of more typical mid-December
weather will develop from Thursday through Saturday as an upper-
level trough spins over southern Canada into the Great Lakes. A
short-wave currently evident on water vapor imagery over British
Columbia will remain well W/SW of Illinois as it tracks
southeastward into Oklahoma by Thursday evening. As a result, am
expecting cool but dry conditions through the period. Highs will be
in the 30s with overnight lows dropping into the lower to middle
20s. Coldest night will be Friday night when overnight lows dip
into the teens in a few locations.
Once the upper trough passes, a return to a southwesterly flow
pattern will lead to rising temperatures and increasing precip
chances next week. While models are still not in perfect agreement,
it is beginning to look like the best rain chances will materialize
by Tuesday into Wednesday as a slow-moving storm system approaches
from the southwest. As a result, have limited PoP mention to Sunday
night when a weak cold front passes...then again Tuesday/Tuesday
night when the more significant system arrives. Aside from the rain
chances, main weather story will be the warmer conditions with highs
climbing back into the 50s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1127 AM CST WED DEC 16 2015
Cold front about to move into KPIA/KSPI, and should reach KCMI
around 21Z. Main effect will initially be a period of gusty
west/southwest winds of 25-30 knots. However, a large shield of
MVFR clouds of 1500-2000 feet is poised to cross the Iowa/Illinois
border shortly. Low level relative humidity plots off the RAP
model suggest a period of several hours of MVFR ceilings at most
central Illinois TAF sites through the evening, but areas as far
east as KCMI are more questionable at this time. However, will
include a TEMPO period of lower ceilings there as well. The parent
low pressure causing the MVFR conditions will be lifting
northeast, so ceilings are expected to rise later in the night.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 PM EST WED DEC 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 357 PM EST WED DEC 16 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE PLAINS INTO THE WRN LAKES. A VIGOROUS SHORTWAVE LIFTING
THROUGH NW WI SUPPORTED A BAND OF SHOWERS NEAR THE WI BORDER INTO
ERN WI. INSTABILITY ASSOCIATED WITH THIS FEATURE WAS GREAT ENOUGH TO
SUPPORT SOME ISOLD TSRA. AT THE SFC...A 991 MB LOW OVER FAR NW WI
WITH AN OCCLUDED FRONT INTO CNTRL WI WAS LIFTING TO THE NORTHEAST.
TEMPS REMAINED IN THE MID 30S WITH MAINLY LIGHT RAIN BEHIND THE
FRONT OVER WRN WI. COLDER AIR WITH PCPN CHANGING TO SNOW HAD MOVED
TO NEAR KMSP.
TONIGHT...EXPECT THE SCT SHOWERS TO LIFT INTO UPPER MI LATE THIS
AFTERNOON. A RUMBLE OF THUNDER MAY ALSO BE POSSIBLE OVER THE WEST.
AS THE LOW LIFTS TO THE NE...ENOUGH COLDER AIR WILL SWEEP IN FROM
THE SW TO CHANGE THE PCPN OVER TO SNOW THIS EVENING. OTHERWISE...WITH
ONLY WEAK UPWARD MOTION WITH THE WRAP-AROUND MOISTURE MOVING
IN...ONLY CHANCE POPS WERE MENTIONED OVER THE WEST. AS WINDS VEER
FROM THE SW TO WSW AFT 06Z AND 850 MB TEMPS DROP TO NEAR -10C...LOW
LEVEL CONV WILL BE MORE FAVORABLE FOR LES OR LAKE ENHANCED SNOW INTO
THE W AND N PORTIONS OF THE KEWEENAW PENINSUSLA WHERE SNOWFALL
AMOUNTS AROUND AN INCH ARE POSSIBLE.
THURSDAY...CONDITIONS WILL GRADUALLY BECOME MORE FAVORABLE FOR LES
ACROSS THE KEWEENAW AS 850 MB TEMPS DROP TO AROUND -12C WITH THE
CONVECTIVE CLOUD LAYER IN THE DGZ. WHILE THERE IS STILL SOME
UNCERTAINTY ON WHERE THE STRONGEST LOW LEVEL CONV WILL
DEVELOP...EXPECT INCREASING LES COULD BRING 1 TO 3 INCHES. TO MAINLY
THE NRN KEWEENAW. OTHWERWISE...TEMPS WILL DROP BACK CLOSER TO NORMAL
WITH HIGHS FROM THE MID 20S WEST TO THE LOW 30S EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 506 PM EST WED DEC 16 2015
IT/S A RETURN TO WINTER...WELL AT LEAST FOR THE KEWEENAW. A LAKE
EFFECT SNOW WATCH REMAINS IN EFFECT FOR THE KEWEENAW PENINSULA
THURSDAY NIGHT THROUGH FRIDAY EVENING...AS WE HAVE PROLONGED W-NW
WINDS AND PLENTY OF MOISTURE STUCK IN THE DGZ...AND 850MB TEMPS OF -
13 TO -17C. TAKING A LOOK AT THE OVERALL PATTERN...A 500MB LOW
SPINNING ACROSS MANITOBA AND THE W HALF OF ONTARIO AT 00Z FRIDAY
WILL HAVE A TROUGH EXTENDED ALL THE WAY THROUGH TX. EXPECT THIS LOW
TO SHIFT OVER JAMES BAY FRIDAY AFTERNOON AS THE TROUGH PUSHES ACROSS
THE GREAT LAKES STATES. LOOK FOR RIDGING TO BEGIN ALOFT ON SATURDAY
AS THE LOW EXITS ACROSS QUEBEC. A PROLONGED RIDGE WILL THEN STAY
ACROSS THE UPPER GREAT LAKES THROUGH SUNDAY.
WEAKER FEATURES WILL PUSH IN FOR THE START OF THE WORK WEEK...WITH A
BROAD BUT MAINLY FLAT TROUGH SET UP ACROSS MUCH OF THE NATION. THE
TROUGH WILL DEEPEN MONDAY NIGHT THROUGH WEDNESDAY...WITH SW FLOW
OVER OUR AREA.
AS FOR THE SFC FEATURES...THE SFC LOW OVER NE MN WILL BE OVER JAMES
BAY AT 00Z FRIDAY AND WILL STAY NEARLY IN PLACE THROUGH SATURDAY.
THIS WILL BE WHEN A SECONDARY LOW RIDING UP THE COLD FRONT OVER THE
ATLANTIC COAST DEEPENS OVER NE CANADA. MOISTURE QUICKLY DIMINISHES
AND INVERSION HEIGHTS LOWER DURING THE DAY SATURDAY AS A RIDGE
TEMPORARILY BUILDS IN. THE NEXT LOW OVER THE CENTRAL PLAINS SUNDAY
MORNING HAS SOME TIMING ISSUES TO RESOLVE...BUT LOOKS TO MOVE ACROSS
THE UPPER GREAT LAKES SOMETIME BETWEEN SUNDAY NIGHT AND MONDAY
EVENING. KEPT POPS IN THE CHANCE RANGE FOR NOW...WITH MAINLY SNOW
EXPECTED EXCEPT NEAR LAKE MI WHERE RAIN MAY MIX IN FROM TIME TO
TIME. THIS OF COURSE WILL GREATLY DEPEND ON THE TRACK. LOOK FOR A
RETURN OF ABOVE NORMAL TEMPERATURES FOR SUNDAY AFTERNOON THROUGH MID
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM EST WED DEC 16 2015
SOUTHEAST WINDS AHEAD OF A LOW PRESSURE SYSTEM LIFTING NORTHEAST
OUT OF NORTHWESTERN IOWA WILL CONTINUE TO BRING IFR TO LOW END MVFR
CEILINGS THROUGH THE REST OF THE DAY. EXPECT A MIX OF RAIN/SNOW AT
THE BEGINNING OF THE TAF PERIOD AT CMX AND SAW WITH THE PCPN AND
SOME LINGERING FOG DROPPING VSBY TO IFR OR NEAR IFR. ONCE THE BAND
MOVES THROUGH...WINDS WILL SHIFT AROUND TO THE SOUTH AND THEN
SOUTHWEST THIS EVENING...LEADING TO CEILINGS RISING INTO THE MVFR
CATEGORY BY LATE TONIGHT. SOME SNOW SHOWERS ARE EXPECTED AT CMX/IWD
TONIGHT...WITH LAKE ENHANCEMENT INCREASING THE SNOW INTENSITY LATE
AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EST WED DEC 16 2015
WINDS WILL QUICKLY SHIFT TO THE SOUTHWEST THIS EVENING AS LOW
PRESSURE OVER NW WI LIFTS TO THE NORTHEAST OF THE AREA. EXPECT
ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE SOUTHWESTERN HALF
OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING. AS THE LOW BECOMES
NEARLY STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS
OF 25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ251-267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
400 PM EST WED DEC 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 357 PM EST WED DEC 16 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE PLAINS INTO THE WRN LAKES. A VIGOROUS SHORTWAVE LIFTING
THROUGH NW WI SUPPORTED A BAND OF SHOWERS NEAR THE WI BORDER INTO
ERN WI. INSTABILITY ASSOCIATED WITH THIS FEATURE WAS GREAT ENOUGH TO
SUPPORT SOME ISOLD TSRA. AT THE SFC...A 991 MB LOW OVER FAR NW WI
WITH AN OCCLUDED FRONT INTO CNTRL WI WAS LIFTING TO THE NORTHEAST.
TEMPS REMAINED IN THE MID 30S WITH MAINLY LIGHT RAIN BEHIND THE
FRONT OVER WRN WI. COLDER AIR WITH PCPN CHANGING TO SNOW HAD MOVED
TO NEAR KMSP.
TONIGHT...EXPECT THE SCT SHOWERS TO LIFT INTO UPPER MI LATE THIS
AFTERNOON. A RUMBLE OF THUNDER MAY ALSO BE POSSIBLE OVER THE WEST.
AS THE LOW LIFTS TO THE NE...ENOUGH COLDER AIR WILL SWEEP IN FROM
THE SW TO CHANGE THE PCPN OVER TO SNOW THIS EVENING. OTHERWISE...WITH
ONLY WEAK UPWARD MOTION WITH THE WRAP-AROUND MOISTURE MOVING
IN...ONLY CHANCE POPS WERE MENTIONED OVER THE WEST. AS WINDS VEER
FROM THE SW TO WSW AFT 06Z AND 850 MB TEMPS DROP TO NEAR -10C...LOW
LEVEL CONV WILL BE MORE FAVORABLE FOR LES OR LAKE ENHANCED SNOW INTO
THE W AND N PORTIONS OF THE KEWEENAW PENINSUSLA WHERE SNOWFALL
AMOUNTS AROUND AN INCH ARE POSSIBLE.
THURSDAY...CONDITIONS WILL GRADUALLY BECOME MORE FAVORABLE FOR LES
ACROSS THE KEWEENAW AS 850 MB TEMPS DROP TO AROUND -12C WITH THE
CONVECTIVE CLOUD LAYER IN THE DGZ. WHILE THERE IS STILL SOME
UNCERTAINTY ON WHERE THE STRONGEST LOW LEVEL CONV WILL
DEVELOP...EXPECT INCREASING LES COULD BRING 1 TO 3 INCHES. TO MAINLY
THE NRN KEWEENAW. OTHWERWISE...TEMPS WILL DROP BACK CLOSER TO NORMAL
WITH HIGHS FROM THE MID 20S WEST TO THE LOW 30S EAST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM EST WED DEC 16 2015
CONCERNS FOCUS ON POTENTIAL FOR HEAVY LAKE EFFECT SNOW OVER THE
KEWEENAW PENINSULA THU NIGHT INTO FRI EVENING.
FAIRLY PROGRESSIVE PATTERN FOR LONG TERM WILL START OUT WITH CENTRAL
PLAINS STORM SYSTEM LIFTING NORTH OF LAKE SUPERIOR ON THU AND
LEAVING THE UPPER GREAT LAKES IN A COLD ADVECTION PATTERN WHICH
COULD GENERATE PERIODS OF MODERATE TO POSSIBLY HEAVY LES OVER W-NW
SNOWBELTS OF LAKE SUPERIOR INTO FRI NIGHT. BROAD MID-LVL RIDGING
BUILDING ACROSS THE CENTRAL CONUS WILL THEN LEAD TO BRIEF PERIOD OF
MILD AND GENERALLY QUIET WEATHER FOR THE WEEKEND BEFORE ANOTHER IN A
SERIES OF PLAINS SYSTEMS BRING A CHANCE OF MORE PRECIPITATION FOR
EARLY NEXT WEEK.
THU INTO FRI NIGHT...PER 00Z MODEL CONSENSUS...COLD ADVECTION IN THE
WAKE OF PLAINS SYSTEM LIFTING NORTH OF LAKE SUPERIOR WILL LOWER 850
MB TEMPS DOWN TO AROUND -12C BY THU EVENING...AND TO -16 TO -17C FRI
AFTERNOON AND FRI NIGHT.
MODEL SOUNDINGS SUGGEST A NUMBER OF FACTORS COMING TOGETHER FOR THE
POTENTIAL OF HEAVY LAKE EFFECT SNOWFALL OVER THE KEWEENAW
PENINSULA...ESPECIALLY BEGINNING LATE THU NIGHT AND CONTINUING INTO
FRI EVENING. FIRST OFF...THE HEART OF THE COLDEST 850 MB TEMPS WILL
BE MOVING ACROSS LAKE SUPERIOR AT THIS TIME WHICH WILL GREATLY
INCREASE INSTABILITY. SECONDLY...MODELS HINT THAT A COUPLE OF
SHORTWAVES WILL BE MOVING DOWN FROM SOUTH CENTRAL CANADA WHICH
DEEPEN MOISTURE TO NEAR 350 MB PER FORECAST SOUNDING PROFILES WHILE
LIFTING INVERSIONS AND PROVIDING AN OPPORTUNITY FOR ENHANCEMENT TO
LAKE EFFECT. PLUGGING IN A WESTERN LAKE SUPERIOR TEMP OF 42F YIELDS
IMPRESSIVE LAKE INDUCED CAPE VALUES IN THE 500-600 J/KG RANGE BY
FRIDAY WITH LAKE INDUCED EQUILIBRIUM HEIGHTS OF 10-11 KFT. BEST
MODEL OMEGA/LIFT INTERSECTS DGZ ON FRIDAY WHICH WILL ALSO CONTRIBUTE
TO FAVORABLE SNOW GROWTH. MODELS ALSO INDICATE LAKE INDUCED
TROUGHING WILL ENHANCE LOW-LEVEL CONVERGENCE IN WESTERLY FLOW IN
RESPONSE TO COLDER AIR MOVING ACROSS THE REGION. GIVEN ALL THE
FAVORABLE FACTORS AND GOOD MODEL AGREEMENT HAVE DECIDED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR THU NIGHT INTO FRI EVENING. FEEL FAIRLY
CONFIDENT THAT TOTAL LES ACCUMULATION WILL EXCEED A FOOT IN MANY
PLACES OVER THE KEWEENAW PENINSULA AND POSSIBLY APPROACH 18 INCHES
AT A FEW SPOTS. THE WESTERLY WINDS GUSTING NEAR 35 MPH WILL ALSO
CAUSE CONSIDERABLE BLOWING SNOW AND OCCASIONAL WHITEOUT CONDITIONS
AT TIMES.
WINDS BACKING WSW OVER ERN LAKE SUPERIOR FROM LAKE INDUCED TROUGH
MAY KEEP ANY DOMINANT W-E LES BAND THAT FORMS OFFSHORE OF ERN
COUNTIES OF CWA UNTIL AT LEAST LATE FRI. PASSAGE OF SFC TROUGH LATE
FRI INTO FRI EVENING WILL BEGIN TO VEER WINDS AROUND MORE WNW AND
COULD BRING MODERATE TO HEAVY LES INTO PORTIONS OF ERN ALGER-LUCE
AND POSSIBLY NRN SCHOOLCRAFT AND FOR WEST INTO NORTHERN
ONTONAGON...SRN HOUGHTON AND BARAGA COUNTIES FRI NIGHT INTO EARLY
SAT.
THIS WEEKEND...LINGERING WNW LES SHOULD BEGIN TO WIND DOWN FROM WEST
TO EAST ON SATURDAY AS COLDEST AIR MOVES WELL EAST IN THE AFTERNOON
AND THE HIGH PRESSURE RIDGE BUILDING IN FROM WEST BEGINS TO BACK
WINDS FROM WNW TO WSW LATE IN DAY. SOUNDINGS SHOW THAT INCREASING
SUBSIDENCE AND DRIER AIR WILL BRING INVERSION HEIGHTS BACK DOWN BLO
4KFT LATE IN THE DAY. EXPECT QUIETER/DRIER WEATHER SAT NIGHT INTO
SUNDAY WITH BROAD MID-LVL RIDGE MOVING ACROSS OVER THE AREA.
SUNDAY NIGHT INTO TUESDAY...WEATHER LOOKS TO BECOME MORE ACTIVE
AGAIN FOR SUN NIGHT INTO MONDAY. THE ECMWF HAS BEEN PRETTY
CONSISTENT THE LAST FEW RUNS BRINGING A NEG-TILT MID-LVL TROUGH
ACROSS THE GREAT LAKES REGION. ECMWF INDICATES SFC LOW ORGANIZING
OVER THE CENTRAL PLAINS ON SUNDAY AND THEN LIFTING NE ACROSS NRN
LAKE MI TO THE MACKINAC STRAITS LATE SUN NIGHT INTO MONDAY. THIS
SOLUTION AND FAVORABLE TRACK WOULD LIKELY BRING WIDESPREAD SNOW TO
UPPER MI LATE SUN NIGHT INTO MONDAY WITH THE POTENTIAL FOR POSSIBLE
LAKE ENHANCED SNOW INTO ERN COUNTIES MON MORNING. THE 00Z GFS
MEANWHILE SHOWS A WEAKER SHORTWAVE MOVING THROUGH THE AREA WITH
ASSOC WEAKER SFC LOW TRACKING MORE INTO WEST OR CENTRAL UPPER MI
WHICH WOULD SUGGEST A LIGHTER MIXED PCPN EVENT. THE 00Z CANADIAN
MODEL IS TRENDING TOWARD THE DEEPER ECMWF SOLUTION AND IS ALSO
TRENDING FARTHER EAST WITH SFC LOW ALTHOUGH ITS SFC LOW TRACK
THROUGH SCNTRL AND EASTERN UPPER MI WOULD PROBABLY YIELD RAIN OR A
MIX OF RAIN/SNOW OVER THE EAST HALF. GIVEN THAT THE CANADIAN IS
TRENDING DEEPER AND FARTHER EAST BELIEVE THIS LENDS MORE CREEDENCE
TO THE MORE CONSISTENT ECMWF SOLUTION SO WILL LEAN THAT WAY WITH THE
FORECAST AND TREND TOWARD MOSTLY SNOW WITH A POSSIBLY MIX OF
RAIN/SNOW NEAR LAKE MI AND FAR EASTERN CWA. WOULD EXPECT DRIER
CONDITIONS MONDAY NIGHT INTO TUESDAY AS SYSTEM LIFTS NE OF THE GREAT
LAKES AND WEAK RIDGING BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM EST WED DEC 16 2015
SOUTHEAST WINDS AHEAD OF A LOW PRESSURE SYSTEM LIFTING NORTHEAST
OUT OF NORTHWESTERN IOWA WILL CONTINUE TO BRING IFR TO LOW END MVFR
CEILINGS THROUGH THE REST OF THE DAY. EXPECT A MIX OF RAIN/SNOW AT
THE BEGINNING OF THE TAF PERIOD AT CMX AND SAW WITH THE PCPN AND
SOME LINGERING FOG DROPPING VSBY TO IFR OR NEAR IFR. ONCE THE BAND
MOVES THROUGH...WINDS WILL SHIFT AROUND TO THE SOUTH AND THEN
SOUTHWEST THIS EVENING...LEADING TO CEILINGS RISING INTO THE MVFR
CATEGORY BY LATE TONIGHT. SOME SNOW SHOWERS ARE EXPECTED AT CMX/IWD
TONIGHT...WITH LAKE ENHANCEMENT INCREASING THE SNOW INTENSITY LATE
AT KCMX.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EST WED DEC 16 2015
WINDS WILL QUICKLY SHIFT TO THE SOUTHWEST THIS EVENING AS LOW
PRESSURE OVER NW WI LIFTS TO THE NORTHEAST OF THE AREA. EXPECT
ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE SOUTHWESTERN HALF
OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING. AS THE LOW BECOMES
NEARLY STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS
OF 25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ251-267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
100 PM EST WED DEC 16 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 447 AM EST WED DEC 16 2015
WINDS HAVE TURNED SOUTHEASTERLY THROUGH THE LATE EVENING YESTERDAY
AND EARLY MORNING HOURS TODAY AND THAT HAS STARTED TO WARM THE LOWER
LEVELS AS MID 30 DEGREE TEMPERATURES ADVECT INTO THE AREA.
TEMPERATURES AT 4AM ARE ABOVE OUR NORMAL HIGHS FOR THIS TIME OF THE
YEAR AND RANGE FROM THE UPPER 30S ALONG THE LAKE MICHIGAN SHORELINE
TO THE UPPER 20S OVER THE HIGHER TERRAIN OF THE WEST. ABUNDANT
MOISTURE BELOW 875MB ON THE 00Z KAPX SOUNDING AND REMAINING OVER THE
AREA FROM THE MOISTURE OVER THE LAST 24 HOURS HAS CONTINUED TO
PRODUCE CEILINGS BETWEEN 1-2KFT OVER THE AREA. POCKETS OF BETTER
MOISTURE AND AIDED BY 890MB TEMPS OF -5C MOVING OVER THE 8C NORTHERN
LAKE MICHIGAN WATERS HAVE LED TO SOME AREAS OF LAKE ENHANCED SNOW
SHOWERS OVER NORTH CENTRAL AND EASTERN UPPER MICHIGAN LATE YESTERDAY
EVENING AND THROUGH THE MORNING HOURS. WITH THE INDICATED CLOUDS
TEMPS FROM RAP SOUNDINGS...AM A LITTLE SURPRISED THE PRECIP HAS
LARGELY BEEN SNOW ON THE OBS...BUT DID RECEIVE A REPORT FROM
MARQUETTE THAT IT WAS MIXING WITH RAIN/DRIZZLE. WITH MDOT ROAD
SENSORS STILL INDICATING ROAD SURFACE TEMPERATURES IN THE 29 TO 35
DEGREE RANGE...ANY DRIZZLE THAT MIXES IN WILL FREEZE AND COULD LEAD
TO SOME PATCHY SLICK SPOTS ON AREA ROADWAYS.
THE SOUTHEASTERLY WINDS WILL INCREASE THROUGH THE MORNING HOURS AS A
995MB LOW...LOCATED IN NORTHWEST IOWA AT 4AM...LIFTS NORTHEAST
THROUGH EASTERN MINNESOTA THROUGH THE DAY AND REACHES FAR WESTERN
LAKE SUPERIOR EARLY THIS EVENING. THIS LOW WILL CONTINUE NORTH-
NORTHEAST INTO NORTHERN ONTARIO TONIGHT. THE FIRST WAVE OF
PRECIPITATION WILL BE TIED TO FORCING ASSOCIATED WITH THE STRONG
ISENTROPIC ASCENT ON THE 280-290K ISENTROPIC SURFACES. DO SEE A
MARKED THINNING OF THE FORCING ABOVE 290K AND TIED TO THE MID LEVEL
DRY AIR...WHICH WILL LIKELY CUT OUT ICE CRYSTALS OUTSIDE THE MAIN
PRECIP BAND. THUS...EXPECT A VERY BRIEF PERIOD (GENERALLY 2-4 HOURS)
OF STRONGER PRECIPITATION WITH THE FORCING BEFORE THE DEEPER
MOISTURE CUTS BACK OUT AND THE AREA TRANSITIONS BACK TO LOW CLOUDS
AND POSSIBLY DRIZZLE OR RAIN SHOWERS DUE TO THE LACK OF ICE CRYSTALS
(CLOUD WARMER THAN -5C). AS FOR THE PRECIP IN THE MAIN BAND...THERE
IS A WARM NOSE INITIALLY (AROUND 800MB)...BUT MODELS SHOW THIS
COOLING WITH EVAPORATIVE COOLING THIS MORNING. THAT LEADS TO A
NEARLY ISOTHERMAL LAYER AROUND OR JUST ABOVE 0C FROM 800MB TO JUST
ABOVE THE SURFACE (WARMING ABOVE FREEZING WITH SOUTHEASTERLY FLOW)
OVER PORTIONS OF THE CENTRAL CWA.
UNFORTUNATELY...SLIGHT SHIFTS IN THE TEMPERATURES WILL MAKE A HUGE
DIFFERENCE IN THE P-TYPE AND WITH DIFFERENT MODELS SHOWING SOME OF
THOSE SUBTLE DIFFERENCES...CONFIDENCE STILL REMAINS LOW ON THE EXACT
SOLUTION. THUS...HAVE FOLLOWED THE FOLLOWING IDEA. SHOWED A
TRANSITION FROM SNOW AND DRIZZLE EARLY THIS MORNING TO A MIX OF
RAIN/SNOW WITH THE BAND OVER THE CENTRAL U.P. AND INCLUDED SOME
SLEET OVER THE FAR WEST AND NORTH CENTRAL BASED OFF LINGERING COLD
AIR IN THE LOWER LEVELS. ALSO INCLUDED SOME SNOW MENTION FOR THE
COUPLE HOUR PERIOD OVER THE WEST AND KEWEENAW WITHIN THE BAND. AS
THE MAIN PRECIP BAND SLIDES OVER THE EASTERN U.P....EXPECT THERE TO
BE ENOUGH LOW LEVEL WARM AIR TO MELT ANY SNOWFLAKES AND HAVE RAIN
THERE. WITH SURFACE TEMPERATURES WARMING...THINK SNOW ACCUMULATION
WILL BE LIMITED BUT DID SHOW SOME AREAS OVER THE HIGHER TERRAIN IN
THE WEST-CENTRAL U.P. SEEING UP TO A HALF INCH OF SNOW. IF THE
PRECIP ENDS UP BEING ALL SNOW...WON/T BE SURPRISED TO SEE A QUICK 1-
2 INCHES OF SNOW. AS FOR LIQUID EQUIVALENT...HAVE INCREASED AMOUNTS
TOWARDS THE HIGHER RESOLUTION RUNS WHICH SHOW MOST AREAS SEEING
BETWEEN 0.15 AND 0.33 INCH...WITH SLIGHTLY HIGHER AMOUNTS OVER THE
SOUTH CENTRAL. AS FOR TIMING...EXPECT A VERY BRIEF PERIOD OF
STRONGER PRECIP OVER THE FAR WEST BETWEEN 13-16Z...WITH A TRANSITION
TO THE BETTER PRECIP OVER THE CENTRAL FROM 14-18Z AND THE EAST FROM
17-22Z. FINALLY...ALTHOUGH ROAD TEMPERATURES START OFF COLD...MODELS
CONSISTENT ON LOW LEVEL WARM AIR MOVING INTO THE AREA UNDER THE
STRONG LOW LEVEL SOUTHEASTERLY FLOW. THAT SHOULD HELP WARM THE LOWER
LEVELS AND LIMIT THE CONCERNS FOR ANY FREEZING RAIN/DRIZZLE AFTER
MID-LATE MORNING.
BEHIND THAT PRIMARY PRECIP BAND...EXPECT A BRIEF TRANSITION TO VERY
LIGHT RAIN OR DRIZZLE BEFORE ANOTHER PERIOD OF SHOWERS OCCUR IN THE
AFTERNOON AS THE ENERGY WITH THE 500MB LOW SWEEPS NORTH-NORTHEAST
THROUGH THE AREA. WITH LIMITED ICE CRYSTALS IN THE CLOUDS...WOULD
EXPECT THIS PRECIP TO FALL AS RAIN BUT COULD SEE SOME MIXING WITH
SNOW AS COLDER AIR ARRIVES TOWARDS EVENING. THAT TIES INTO THE
FORECAST FOR TONIGHT...WITH THE BEST PRECIP CHANCES OVER THE WESTERN
THIRD OF THE CWA WHERE THE DEEPER MOISTURE IS LOCATED ON THE BACK
SIDE OF THE LOW. THIS PRECIP WILL BE AIDED LATE TONIGHT BY A
SHORTWAVE WRAPPING AROUND THE BACKSIDE OF THE 500MB LOW AND
IMPACTING THE WESTERN U.P.. A LOW LEVEL TROUGH WILL ALSO BE MOVING
THROUGH THE WESTERN U.P. AT THAT TIME...SWITCHING THE LOW LEVEL
WINDS A LITTLE MORE WESTERLY AND ALSO USHERING IN COLDER AIR THAT
WILL PERSIST THROUGH THE START OF THE WEEKEND. WITH THE LATE ARRIVAL
OF THE COLD AIR FOR THE SHORT TERM FORECAST...DON/T EXPECT TOO MUCH
LAKE ENHANCEMENT OVER THE WEST UNTIL VERY LATE IN THE PERIOD AND
MORE INTO THE THURSDAY TIME-FRAME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 509 AM EST WED DEC 16 2015
CONCERNS FOCUS ON POTENTIAL FOR HEAVY LAKE EFFECT SNOW OVER THE
KEWEENAW PENINSULA THU NIGHT INTO FRI EVENING.
FAIRLY PROGRESSIVE PATTERN FOR LONG TERM WILL START OUT WITH CENTRAL
PLAINS STORM SYSTEM LIFTING NORTH OF LAKE SUPERIOR ON THU AND
LEAVING THE UPPER GREAT LAKES IN A COLD ADVECTION PATTERN WHICH
COULD GENERATE PERIODS OF MODERATE TO POSSIBLY HEAVY LES OVER W-NW
SNOWBELTS OF LAKE SUPERIOR INTO FRI NIGHT. BROAD MID-LVL RIDGING
BUILDING ACROSS THE CENTRAL CONUS WILL THEN LEAD TO BRIEF PERIOD OF
MILD AND GENERALLY QUIET WEATHER FOR THE WEEKEND BEFORE ANOTHER IN A
SERIES OF PLAINS SYSTEMS BRING A CHANCE OF MORE PRECIPITATION FOR
EARLY NEXT WEEK.
THU INTO FRI NIGHT...PER 00Z MODEL CONSENSUS...COLD ADVECTION IN THE
WAKE OF PLAINS SYSTEM LIFTING NORTH OF LAKE SUPERIOR WILL LOWER 850
MB TEMPS DOWN TO AROUND -12C BY THU EVENING...AND TO -16 TO -17C FRI
AFTERNOON AND FRI NIGHT.
MODEL SOUNDINGS SUGGEST A NUMBER OF FACTORS COMING TOGETHER FOR THE
POTENTIAL OF HEAVY LAKE EFFECT SNOWFALL OVER THE KEWEENAW
PENINSULA...ESPECIALLY BEGINNING LATE THU NIGHT AND CONTINUING INTO
FRI EVENING. FIRST OFF...THE HEART OF THE COLDEST 850 MB TEMPS WILL
BE MOVING ACROSS LAKE SUPERIOR AT THIS TIME WHICH WILL GREATLY
INCREASE INSTABILITY. SECONDLY...MODELS HINT THAT A COUPLE OF
SHORTWAVES WILL BE MOVING DOWN FROM SOUTH CENTRAL CANADA WHICH
DEEPEN MOISTURE TO NEAR 350 MB PER FORECAST SOUNDING PROFILES WHILE
LIFTING INVERSIONS AND PROVIDING AN OPPORTUNITY FOR ENHANCEMENT TO
LAKE EFFECT. PLUGGING IN A WESTERN LAKE SUPERIOR TEMP OF 42F YIELDS
IMPRESSIVE LAKE INDUCED CAPE VALUES IN THE 500-600 J/KG RANGE BY
FRIDAY WITH LAKE INDUCED EQUILIBRIUM HEIGHTS OF 10-11 KFT. BEST
MODEL OMEGA/LIFT INTERSECTS DGZ ON FRIDAY WHICH WILL ALSO CONTRIBUTE
TO FAVORABLE SNOW GROWTH. MODELS ALSO INDICATE LAKE INDUCED
TROUGHING WILL ENHANCE LOW-LEVEL CONVERGENCE IN WESTERLY FLOW IN
RESPONSE TO COLDER AIR MOVING ACROSS THE REGION. GIVEN ALL THE
FAVORABLE FACTORS AND GOOD MODEL AGREEMENT HAVE DECIDED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR THU NIGHT INTO FRI EVENING. FEEL FAIRLY
CONFIDENT THAT TOTAL LES ACCUMULATION WILL EXCEED A FOOT IN MANY
PLACES OVER THE KEWEENAW PENINSULA AND POSSIBLY APPROACH 18 INCHES
AT A FEW SPOTS. THE WESTERLY WINDS GUSTING NEAR 35 MPH WILL ALSO
CAUSE CONSIDERABLE BLOWING SNOW AND OCCASIONAL WHITEOUT CONDITIONS
AT TIMES.
WINDS BACKING WSW OVER ERN LAKE SUPERIOR FROM LAKE INDUCED TROUGH
MAY KEEP ANY DOMINANT W-E LES BAND THAT FORMS OFFSHORE OF ERN
COUNTIES OF CWA UNTIL AT LEAST LATE FRI. PASSAGE OF SFC TROUGH LATE
FRI INTO FRI EVENING WILL BEGIN TO VEER WINDS AROUND MORE WNW AND
COULD BRING MODERATE TO HEAVY LES INTO PORTIONS OF ERN ALGER-LUCE
AND POSSIBLY NRN SCHOOLCRAFT AND FOR WEST INTO NORTHERN
ONTONAGON...SRN HOUGHTON AND BARAGA COUNTIES FRI NIGHT INTO EARLY
SAT.
THIS WEEKEND...LINGERING WNW LES SHOULD BEGIN TO WIND DOWN FROM WEST
TO EAST ON SATURDAY AS COLDEST AIR MOVES WELL EAST IN THE AFTERNOON
AND THE HIGH PRESSURE RIDGE BUILDING IN FROM WEST BEGINS TO BACK
WINDS FROM WNW TO WSW LATE IN DAY. SOUNDINGS SHOW THAT INCREASING
SUBSIDENCE AND DRIER AIR WILL BRING INVERSION HEIGHTS BACK DOWN BLO
4KFT LATE IN THE DAY. EXPECT QUIETER/DRIER WEATHER SAT NIGHT INTO
SUNDAY WITH BROAD MID-LVL RIDGE MOVING ACROSS OVER THE AREA.
SUNDAY NIGHT INTO TUESDAY...WEATHER LOOKS TO BECOME MORE ACTIVE
AGAIN FOR SUN NIGHT INTO MONDAY. THE ECMWF HAS BEEN PRETTY
CONSISTENT THE LAST FEW RUNS BRINGING A NEG-TILT MID-LVL TROUGH
ACROSS THE GREAT LAKES REGION. ECMWF INDICATES SFC LOW ORGANIZING
OVER THE CENTRAL PLAINS ON SUNDAY AND THEN LIFTING NE ACROSS NRN
LAKE MI TO THE MACKINAC STRAITS LATE SUN NIGHT INTO MONDAY. THIS
SOLUTION AND FAVORABLE TRACK WOULD LIKELY BRING WIDESPREAD SNOW TO
UPPER MI LATE SUN NIGHT INTO MONDAY WITH THE POTENTIAL FOR POSSIBLE
LAKE ENHANCED SNOW INTO ERN COUNTIES MON MORNING. THE 00Z GFS
MEANWHILE SHOWS A WEAKER SHORTWAVE MOVING THROUGH THE AREA WITH
ASSOC WEAKER SFC LOW TRACKING MORE INTO WEST OR CENTRAL UPPER MI
WHICH WOULD SUGGEST A LIGHTER MIXED PCPN EVENT. THE 00Z CANADIAN
MODEL IS TRENDING TOWARD THE DEEPER ECMWF SOLUTION AND IS ALSO
TRENDING FARTHER EAST WITH SFC LOW ALTHOUGH ITS SFC LOW TRACK
THROUGH SCNTRL AND EASTERN UPPER MI WOULD PROBABLY YIELD RAIN OR A
MIX OF RAIN/SNOW OVER THE EAST HALF. GIVEN THAT THE CANADIAN IS
TRENDING DEEPER AND FARTHER EAST BELIEVE THIS LENDS MORE CREEDENCE
TO THE MORE CONSISTENT ECMWF SOLUTION SO WILL LEAN THAT WAY WITH THE
FORECAST AND TREND TOWARD MOSTLY SNOW WITH A POSSIBLY MIX OF
RAIN/SNOW NEAR LAKE MI AND FAR EASTERN CWA. WOULD EXPECT DRIER
CONDITIONS MONDAY NIGHT INTO TUESDAY AS SYSTEM LIFTS NE OF THE GREAT
LAKES AND WEAK RIDGING BUILDS IN FROM THE WEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1259 PM EST WED DEC 16 2015
SOUTHEAST WINDS AHEAD OF A LOW PRESSURE SYSTEM LIFTING NORTHEAST
OUT OF NORTHWESTERN IOWA WILL CONTINUE TO BRING IFR TO LOW END MVFR
CEILINGS THROUGH THE REST OF THE DAY. EXPECT A MIX OF RAIN/SNOW AT
THE BEGINNING OF THE TAF PERIOD AT CMX AND SAW WITH THE PCPN AND
SOME LINGERING FOG DROPPING VSBY TO IFR OR NEAR IFR. ONCE THE BAND
MOVES THROUGH...WINDS WILL SHIFT AROUND TO THE SOUTH AND THEN
SOUTHWEST THIS EVENING...LEADING TO CEILINGS RISING INTO THE MVFR
CATEGORY BY LATE TONIGHT. SOME SNOW SHOWERS ARE EXPECTED AT CMX/IWD
TONIGHT...WITH LAKE ENHANCEMENT INCREASING THE SNOW INTENSITY LATE
AT KCMX.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EST WED DEC 16 2015
A LOW PRESSURE SYSTEM LIFTING FROM NORTHWEST IOWA TO FAR WESTERN
LAKE SUPERIOR TODAY WILL LEAD TO SOUTHEASTERLY GALES TO 35-40KTS
OVER PORTIONS OF LAKE SUPERIOR TODAY. WINDS WILL QUICKLY SHIFT TO
THE SOUTHWEST THIS EVENING AS THE LOW LIFTS TO THE NORTHEAST OF THE
AREA AND EXPECT ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE
SOUTHWESTERN HALF OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING.
HAVE MADE SOME ADJUSTMENTS TO THE GALE WARNINGS TO EXTEND THEM INTO
THURSDAY NIGHT. ALTHOUGH THERE WILL BE A BRIEF LULL THIS
EVENING...FELT IT WAS BETTER TO KEEP THEM GOING SINCE IT WILL BE A
PROLONGED LOW END GALE EVENT. AS THE LOW BECOMES NEARLY
STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS OF
25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ251-267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS JACKSON MS
1041 AM CST WED DEC 16 2015
.UPDATE...MORNING SURFACE ANALYSIS HAD A COLD FRONT JUST EDGING INTO
OUR WESTERN ZONES AND STRETCHING SOUTH ALONG THE TEXAS COAST WHERE A
WEAK LOW WAS NOTED. A WARM FRONT WAS ALSO NOTED FROM THE SURFACE LOW
OVER THE TEXAS COAST EXTENDING UP ALONG THE LOUISIANA AND MISSISSIPPI
GULF COAST. LOCAL RADARS SHOW A BAND OF SHOWERS AND A FEW
THUNDERSTORMS JUST AHEAD OF THE COLD FRONT AND GENERALLY FROM
GRENADA TO NATCHEZ THAT HAS WEAKENED THE LAST COUPLE OF HOURS.
EARLIER THIS MORNING AHEAD OF THIS BAND OF CONVECTION AREAS OF FOG
DEVELOPED. THE FOG HAS LIFTED BUT THICK CLOUD COVER REMAINED OVER
MOST OF THE CWA. TOGETHER THESE FEATURES MAKE A TOUGH TEMPERATURE
FORECAST. THE FORECAST IS GENERALLY ON TRACK BUT HAVE REFINED POPS
AND WEATHER BASED ON LATEST RADAR TREND AND HI-RES MODELS. WAA WILL
CONTINUE TO INCREASE THIS AFTERNOON AND EVENING AHEAD OF THE
APPROACHING SURFACE LOW FOLLOWED BY THE PASSAGE OF THE COLD FRONT.
CONDITIONS LOOK LESS FAVORABLE THIS MORNING FOR SEVERE HAIL
DEVELOPMENT BUT A FEW STRONG TO SEVERE STORMS WITH DAMAGING WINDS AND
A TORNADO OR TWO LOOK POSSIBLE OVER OUR SOUTHEAST LATE THIS AFTERNOON
AND EVENING. /22/
&&
.AVIATION...THE FOG IS SLOWLY LIFTING/MIXING OUT AND EXPECT LIFR
CATEGORY STRATUS TO GRADUALLY IMPROVE TO IFR AND EVENTUALLY MVFR
CATEGORIES AS WE GO INTO THE AFTN...BUT INCREASING SHRA/TSRA WILL
MAKE FOR PERIODIC HAZARDOUS AVIATION CONDITIONS THROUGH THE AFTN AND
MOST OF TONIGHT...PARTICULARLY DURING THE LATE AFTN AND EVENING
ALONG/E OF THE JAN/HKS TO GTR CORRIDOR WHERE TSRA COVERAGE SHOULD BE
MOST PREVALENT. /EC/
&&
.PREV DISCUSSION... /ISSUED 757 AM CST WED DEC 16 2015/
UPDATE...MADE AN UPDATE TO ADD FOG AND MENTION OF POSSIBLE DENSE FOG
IN THE HWO/GRAPHICS FOR THIS MORNING. THICK FOG HAS BEEN ADVECTING
NORTHWARD IN THE STRONG WARM ADVECTION REGIME AND VISIBILITIES ARE
DOWN TO A QUARTER MILE AT TIMES WITH THE LATEST HRRR SUGGESTING THIS
WILL LAST THROUGH MID MORNING. BELIEVE THERE SHOULD BE JUST ENOUGH
MIXING WITH HEATING TO KEEP THIS FROM BEING A DENSE FOG EVENT WORTHY
OF AN ADVISORY. /EC/
PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 16 2015/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...THE PRIMARY FORECAST
CONCERN WILL BE OUR WEATHER TODAY AND THIS EVENING. CURRENT RADARS
SHOW A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS MOVING THROUGH
CENTRAL LOUISIANA THIS MORNING ALONG WITH SOME DISCRETE STORMS AHEAD
OF THE LINE. THIS IS LOCATED ALONG/JUST AHEAD OF A COLD FRONT THAT
WILL MOVE THROUGH OUR REGION TODAY. THIS IS IN ASSOCIATION WITH A
LARGE UPPER LOW AND DEEP SFC LOW THAT WILL BOTH TRACK ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY TODAY TOWARD THE GREAT LAKES REGION.
THE COLD FRONT WILL MOVE THROUGH DURING THE AFTERNOON. MUCH OF THIS
ACTIVITY ENTERING THE DELTA THIS MORNING WILL REMAIN ELEVATED AS
BOUNDARY LAYER REMAINS STABLE WITH NO SFC BASED CAPE AVAILABLE. MID
LEVEL LAPSE RATES ARE DECENT ENOUGH TO WHERE SOME SMALL HAIL COULD
BE POSSIBLE WITH THESE MORNING STORMS BUT OVERALL SHOULD NOT BE A
BIG DEAL OTHER THAN SOME RAIN AND LIGHTNING.
AS THE FRONT CROSSES THE REGION TODAY...MODELS CONTINUE TO AGREE
THAT A WEAK SFC LOW WILL DEVELOP ALONG THE SOUTHERN END. THIS LOW
WILL TRACK NORTHEAST INTO THE GULF COAST...ACROSS MY SOUTHEASTERN
COUNTIES...AND EVENTUALLY INTO ALABAMA. THE OVERALL THINKING REMAINS
THE SAME REGARDING OUR POTENTIAL FOR A FEW STRONG TO SEVERE STORMS.
THE BETTER CHANCES FOR THIS WILL BE IN THE PINE BELT REGION OR
SLIGHTLY NORTH OF THERE LATER THIS AFTERNOON INTO THIS EVENING. HI-
RES MODELS SHOW MORE CELLULAR STORMS DEVELOPING/MOVING NORTH ACROSS
THIS REGION LATE THIS AFTERNOON BEFORE COVERAGE INCREASES AFTER 00Z
TONIGHT. LOW LEVEL SHEAR IS MARGINAL AROUND 20KTS WITH BETTER DEEP
LAYER SHEAR(AROUND 40-50KTS). MORE INSTABILITY IS FORECAST WITH THIS
SYSTEM THAN WAS FORECAST WITH THE LAST SO THIS SHOULD NOT BE AN
ISSUE AS A WARM FRONT MOVES NORTH ACROSS THE AREA...LEAVING THE
SOUTHEAST IN THE WARM SECTOR. JUST HOW FAR NORTH IT GETS WILL BE THE
QUESTION AS TO HOW MUCH OF THE AREA HAS POTENTIAL FOR STRONG TO
SEVERE STORMS. TEMPERATURES IN THE SOUTHEAST SHOULD REACH THE LOWER
70S AHEAD OF THE FRONT DESPITE INCREASING CLOUD COVER. MOST UNSTABLE
CAPE IS BEING ADVERTISED AROUND 700 J/KG WITH THE NAM SHOWING VALUES
OVER 1000J/KG. THE SOUTHEAST IS ALSO WHERE SFC BASED CAPE IS
FORECAST TO BE AROUND 800-1000 J/KG. WILL CONTINUE WITH THE MENTION
OF DAMAGING WIND GUSTS AND A NON-ZERO RISK FOR A TORNADO AS
INGREDIENTS MAY BE JUST ENOUGH...ALONG WITH THE PROXIMITY OF THE
BOUNDARY...FOR THIS TO BE CONSIDERED.
RAIN WILL TAPER OFF FROM WEST TO EAST THROUGH THE NIGHT AND BE CLEAR
OF THE ARKLAMISS BY THURSDAY MORNING. COOLER AIR WILL FILTER INTO
THE REGION BEHIND THE FRONT WITH HIGHS ON THURSDAY IN THE 50S.
OVERNIGHT LOWS FRIDAY MORNING WILL DIP INTO THE 30S AS THE UPPER
TROUGH SWINGS ACROSS THE REGION AND HIGH PRESSURE AT THE SFC BEGINS
TO SLIDE IN. /28/
LONG TERM...FRIDAY THROUGH NEXT TUESDAY...A COOL SEASONABLE AIRMASS
WILL BE OVER THE REGION IN THE WAKE OF THE COLD FRONT WITH AROUND
SEASONABLE TEMPERATURES WITH HIGHS IN THE 50S ON FRIDAY. HIGHS WILL
SLOWLY MODERATE INTO THE LOWER TO MIDDLE 60S BY SUNDAY AFTERNOON.
THIS WILL BE DUE TO SOME BROAD FLAT UPPER RIDGING COMING IN FROM THE
WEST WITH LOW LEVEL RETURN FLOW. AS WE PUSH INTO THE EARLY PART OF
THE WORK WEEK HIGHS WILL BE WELL ABOVE NORMAL WITH READINGS REACHING
THE LOWER 70S. LOWS WILL MODERATE FROM THE LOWER 30S FRIDAY NIGHT TO
THE 40S AND 50S BY SUNDAY NIGHT...THEN WILL WARM INTO THE UPPER 50S
TO AROUND 60S EARLY NEXT WEEK...WHICH IS ALSO WELL ABOVE NORMAL. OUR
CHANCES OF RAIN WILL COME BACK FOR SUNDAY NIGHT INTO EARLY NEXT WEEK.
THIS WILL BE DUE TO A SERIES OF WEAK SHORTWAVES IN SOUTHWEST FLOW
AHEAD OF A STATIONARY FRONT TO THE WEST. INSTABILITY WILL BE RATHER
WEAK.
AS WE LOOK INTO THE REMAINDER OF THE WORK WEEK A BROAD UPPER TROUGH
WILL PUSH A STORM SYSTEM TOWARD THE REGION AS WE NEAR CHRISTMAS
EVE./17/
AVIATION...VFR CATEGORIES WILL CONTINUE AT MOST TAF SITES THIS
MORNING BUT CLOUDS ARE ON THE INCREASE AS MOISTURE INCREASES AHEAD
OF A COLD FRONT. THIS FRONT WILL BRING SHOWERS AND STORMS TO THE AREA
TODAY. KGLH SHOULD SEE STORMS BEFORE 18Z WHILE OTHER SITES MAYBE
LATER...ESPECIALLY KPIB/KHBG/KMEI. LOW STRATUS AND/OR PATCHY FOG IS
MOVING INTO SOUTHERN MISSISSIPPI AS OF 10Z AND WILL LIKELY REDUCE
CEILINGS TO MVFR CATEGORIES THROUGH 15Z. EXPECT FURTHER FLIGHT CAT
DETERIORATION IN A MAJORITY OF THE REGION THROUGH MID TO LATE
MORNING AS SHOWERS AND EMBEDDED STORMS INCREASE. WINDS WILL BE OUT OF
THE SOUTH...LIGHT TO CALM EARLY THIS MORNING BEFORE INCREASING TO
AROUND 10KTS(HIGHER IN THUNDERSTORMS). /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 72 48 56 34 / 71 96 13 3
MERIDIAN 70 49 58 33 / 82 99 13 5
VICKSBURG 70 48 55 35 / 86 49 9 2
HATTIESBURG 75 53 62 36 / 80 94 13 3
NATCHEZ 73 48 57 36 / 78 60 10 2
GREENVILLE 65 40 54 33 / 89 21 4 3
GREENWOOD 66 42 54 32 / 77 46 11 3
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
22/EC/28/17
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
334 PM CST WED DEC 16 2015
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Wed Dec 16 2015
(Tonight)
Surface low across north-central Minnesota will northeastward toward
the US-Canadian border tonight. Trailing occluded front will have
passed through the far eastern CWA before this evening begins with
cold advection in its wake. Stratus/stratocu deck has struggled with
its eastward progression today and expect cumulus elements to
dissipate with loss of daytime heating with stratus remaining up
across mainly portions of northeast Missouri tonight. Low
temperatures are expected to range from the mid 20s to around 30
degrees tonight and is a blend of available guidance.
Gosselin
.LONG TERM: (Thursday through Next Wednesday)
Issued at 333 PM CST Wed Dec 16 2015
Cool high pressure will continue building southeast across the Great
Plains on Thursday and into the lower Mississippi Valley on Friday.
Looks like there will be quite a bit of strato-cu on Thursday
afternoon as the the next shortwave digs into the mean long wave
pattern over the Mississippi Valley. This should help to keep
temperatures cool...so I leaned toward the cooler side of guidance
for highs Thursday. The secondary cold front associated with the
shortwave will pass through the area late Thursday, and the second
cooler shot of cold air will slide in on top of us Friday into
Saturday. Temperatures through Saturday morning will be closer to
normal (tho still a bit above) with highs in the low to mid 40s and
lows mainly in the low to mid 20s. The center of the high will move
east of the area by late Saturday bringing southerly flow and
milder temperatures back to the Mid Mississippi Valley.
Sunday through Tuesday will be mild with quasi-zonal flow aloft.
Rain chances increase Sunday into Monday as another cold front moves
through the area. Medium range guidance stalls the front over
southern Missouri/northern Arkansas Monday night. The chance for
precipitation diminishes north of the front, but never really ends.
The front moves back north Tuesday and Tuesday night with rain
chances increasing again through Wednesday. Temperatures look to
remain well above normal...mainly in the 50s and even low 60s for
highs and 30s-40s for lows.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1119 AM CST Wed Dec 16 2015
Main concern for aviation over the next 24-30 hours will be on
stratus/stratocu deck currently over northern Missouri. Relied on
the RAP through this evening as it seems to have the best handle
so far today. Believe KUIN will see at least a period of MVFR
ceilings this afternoon...timing of improvement a big unknown this
evening/overnight. Further south...appears KCOU and metro TAF
sites will be too far south except for some FEW-SCT stratocu
clouds with bases around 3000 feet. WSW winds will veer to the NW
later on tonight with gusts diminishing. For Thursday...cyclonic
flow aloft may again pose problems with stratus/stratocu which may
be MVFR but for now left SCT at each terminal due to uncertainty.
Specifics for KSTL:
Main concern for aviation over the next 24-30 hours will be on
stratus/stratocu deck currently over northern Missouri. Relied on
the RAP through this evening as it seems to have the best handle
so far today. Appears KSTL will be too far south except for some
FEW-SCT stratocu clouds with bases around 3000 feet. WSW winds
will veer to the NW later on tonight with gusts diminishing. For
Thursday...cyclonic flow aloft may again pose problems with
stratus/stratocu which may be MVFR but for now left SCT at each
terminal due to uncertainty.
Gosselin
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 32 40 28 42 / 0 5 5 5
Quincy 30 37 25 37 / 5 0 0 5
Columbia 28 39 25 39 / 0 5 5 0
Jefferson City 27 41 24 40 / 0 5 5 0
Salem 31 40 29 39 / 5 5 5 5
Farmington 28 42 25 40 / 0 5 5 5
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1128 AM CST WED DEC 16 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 337 AM CST Wed Dec 16 2015
NNE-SSW oriented band of showers rapidly developed from the
eastern Ozarks into central Illinois over the past few hours.
This precip is associated with narrow tongue of low level
moisture streaming north ahead of approaching cold front/dry
line, and being lifted through a combination of weak isentropic
ascent and larger scale lift associated with upper level trof
pushing northeast from the Plains.
This band of precip should work east during the morning and
diminish in coverage due to weakening of the low level forcing.
However, I have held onto some mention of showers until the
passage of the cold front/dry line, as some of the hi-res
solutions do indicate spotty along the boundary, and in the wake
of the ongoing showers.
The passage of the surface boundary will mean the onset of cold
advection, but temperature forecast is quite tricky due to the
fact that 1-many areas will be starting out fairly mild, 2-strong
gradient will allow for deep mixing, and 3-there will be a good
deal of sunshine after fropa and before cold air SC sweeps into
northern sections of the CWA during the afternoon hours.
Afternoon highs should once again exhibit a wide range, from the
lower 40s over our extreme northwest counties, to perhaps 60 in a
few locations over the southeast half of the CWA.
Truett
.LONG TERM: (Tonight through Tuesday)
Issued at 337 AM CST Wed Dec 16 2015
The aforementioned cdfnt will have cleared the CWA by early
evening. A vort max located over southern AZ early this morning
will have reached TX by 00z tonight, then continue on to the
MO/AR border by 12z Thu. No impacts are currently expected from
this feature. Overnight lows in the upper 20s to near 30 degrees
will be much closer to seasonal normals than what has been
observed lately.
A vort max which will be located near the BC/WA border at 12z Wed
will quickly dive sewd into the southern plains by 12z Thu and
reinforce the trough over the central CONUS. A couple of vorticity
maxima are expected to move through the trough before it shifts
eastward on Fri night, but no pcpn is expected attm due to
limited moisture through the column. Attm it appears the primary
effect of these features will be to increase cloudiness across
the region towards the end of the work week. High and low
temperatures will remain near seasonal normals through Fri night.
Sfc high pressure center shifts ewd on Sat night and winds become
southerly to southwesterly, and a non-diurnal temperature trend
may eventually be needed for Sat night to capture the initial
drop-off followed by steady or slowly rising temps associated with
southerly winds. Temperatures will be noticeably warmer on Sat
across central MO and the eastern Ozarks. A significant warm-up
is then anticipated on Sunday for the entire CWA. These warmer
temperatures could last into the early part of next week depending
on the speed and track of a low pressure system which is forecast
to move across the central part of the country late this weekend
and early next week, bringing a chance of rain to the region.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1119 AM CST Wed Dec 16 2015
Main concern for aviation over the next 24-30 hours will be on
stratus/stratocu deck currently over northern Missouri. Relied on
the RAP through this evening as it seems to have the best handle
so far today. Believe KUIN will see at least a period of MVFR
ceilings this afternoon...timing of improvement a big unknown this
evening/overnight. Further south...appears KCOU and metro TAF
sites will be too far south except for some FEW-SCT stratocu
clouds with bases around 3000 feet. WSW winds will veer to the NW
later on tonight with gusts diminishing. For Thursday...cyclonic
flow aloft may again pose problems with stratus/stratocu which may
be MVFR but for now left SCT at each terminal due to uncertainty.
Specifics for KSTL:
Main concern for aviation over the next 24-30 hours will be on
stratus/stratocu deck currently over northern Missouri. Relied on
the RAP through this evening as it seems to have the best handle
so far today. Appears KSTL will be too far south except for some
FEW-SCT stratocu clouds with bases around 3000 feet. WSW winds
will veer to the NW later on tonight with gusts diminishing. For
Thursday...cyclonic flow aloft may again pose problems with
stratus/stratocu which may be MVFR but for now left SCT at each
terminal due to uncertainty.
Gosselin
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
944 AM MST WED DEC 16 2015
.UPDATE...
STRONG SHORTWAVE EMBEDDED IN THE MEAN NORTHWEST FLOW WILL
CONTINUE TO PUSH SOUTH AND SOUTHEAST THIS MORNING. GOOD
DIFFLUENCE ALOFT COMBINED WITH MODERATE LAPSE RATES WILL ALLOW THE
FOOTHILLS OF THE BEARTOOTH-ABSAROKA MOUNTAINS NEAR RED LODGE TO
SEE THE MOST OUT OF THIS SYSTEM. RADAR RETURNS WERE INCREASING
UPSTREAM NEAR GREAT FALLS AT THIS HOUR AND THESE WILL MOVE SOUTH
THROUGH THE DAY.
ONLY MAJOR CHANGES TO THE FORECAST WERE TO LOWER POPS OUT EAST AS
PRIMARY SHORTWAVE LOOKS TOO FAR TO THE WEST FOR ANY APPRECIABLE
POPS OUT EAST. HRRR LOOKS TO BE HANDLING THE SITUATION WELL AND IT
WAS NOT VERY CONFIDENT ABOUT POPS EAST OF POWDER RIVER AND CUSTER
COUNTIES. DOBBS
&&
.SHORT TERM...VALID FOR TDY AND THU...
CLIPPER SYSTEM LOCATED NEAR PRINCE GEORGE BC AROUND MIDNIGHT WILL
TRACK ACROSS THE SOUTHWEST PORTION OF THE AREA TODAY AND BRING A
BURST OF MAINLY MOUNTAIN AND FOOTHILL SNOW. MIDLEVEL LAPSE RATES
AROUND 7.5 C/KM AND UPSLOPE SHOULD SUPPORT A 6 HOUR WINDOW OF
GOOD SNOW SHOWERS AND AM RAISING ACCUMULATIONS AS SNOW GROWTH
REGION IS IN A FAVORABLE AREA. PATTERN IS SIMILAR TO OTHER CASES
WHERE RED LODGE DOES BEST WITH ACCUMULATIONS AND WILL ISSUE A
WINTER WEATHER ADVISORY FROM NOON TO MIDNIGHT. WILL LIKELY SEE
SOME 2-3 INCH AMOUNTS IN THE PARADISE VALLEY AND THE STILLWATER
VALLEY BUT RED LODGE FOOTHILLS ALONG WITH THE MOUNTAINS SHOULD SEE
4 TO 6 INCH AMOUNTS.
PLAINS WILL SEE SOME LIGHT SNOWFALL OUT OF THIS SYSTEM BUT WEAKER
UPSLOPE WILL KEEP AMOUNTS CLOSER TO THE 1 TO 2 INCH RANGE SOUTH
AND WEST OF A HARLOWTON TO BILLINGS LINE. NORTH AND EAST OF THIS
LINE IT SHOULD JUST BE SNOW SHOWERS. FOOTHILLS WILL ALSO HOLD ONTO
THE SNOW LONGER WHEREAS THE PLAINS WILL SEE SNOW END EARLY
EVENING. TEMPERATURES WILL MOSTLY BE IN THE 20S AS CLOUDS HAVE
MOVED INTO THE AREA WHICH SLOWED OVERNIGHT COOLING BUT WILL LIMIT
SUNSHINE TODAY.
DRYING ARRIVES ON THURSDAY AS AN UPPER LEVEL RIDGE BUILDS INTO
WESTERN MONTANA. WILL BE A COLD NIGHT ACROSS THE WESTERN ZONES AS
SKIES WILL BE CLEARER FOR A LONGER PERIOD OVERNIGHT. EASTERN AREAS
MAY NOT BE AS COLD AS WINDS INCREASE WITH A CLIPPER SYSTEM MOVING
INTO THE DAKOTAS. THIS SETS THE STAGE FOR MOST PLACES TO STRUGGLE
TO REACH THE 20S FOR DAYTIME HIGHS THURSDAY AND COULD BE A RAW
DAY AS WINDS WILL BE STRONGER DUE TO THE CLIPPER BEFORE
DECREASING IN THE AFTERNOON. CLOUDS AND FALLING SURFACE PRESSURES
ARRIVE THURSDAY NIGHT FOR THE WESTERN ZONES TO MODERATE OVERNIGHT
LOWS BUT EASTERN MONTANA WILL SEE CLEARER SKIES AND LIGHTER WINDS
AND BELOW ZERO TEMPS ARE POSSIBLE. BORSUM
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
AN UPPER RIDGE BUILDS INTO THE NORTHERN ROCKIES ON FRIDAY. THIS
WILL PRODUCE WARMER TEMPERATURES FRIDAY AND SATURDAY. THE FLOW
BACKS AND THIS WILL CAUSE AN INCREASE IN SNOW CHANCES FOR THE
MOUNTAINS. A SPLITTING TROUGH MOVES ACROSS THE AREA SATURDAY AND
THIS WILL SPREAD THE CHANCE OF SNOW SHOWERS INTO THE PLAINS. THE
SYSTEM WAS WEAK...BUT CONTAINS A DECENT SLUG OF MOISTURE...SO
RAISED POPS FOR THIS. THIS EVENT WILL START THE HEIGHT LOWERING
PROCESS INTO NEXT WEEK...WHICH WILL LEAD TO COLDER TEMPERATURES.
LOOKS LIKE THE MUCH COLDER AIR HOLDS OFF UNTIL LATE NEXT WEEK WHEN
A DEEP TROUGH DIGS OVER THE WEST COAST AND PULLS SOME -10C AIR
INTO MONTANA. UNTIL THAT OCCURS...SHOULD HAVE SEASONAL TO SLIGHTLY
BELOW SEASONAL TEMPERATURES THROUGH MOST OF NEXT WEEK.
ALSO...COULD HAVE STRONG WINDS DEVELOP AT LIVINGSTON AND NYE
SATURDAY NIGHT INTO SUNDAY. BUMPED WINDS UP FOR THAT PERIOD. TWH
&&
.AVIATION...
MVFR CEILINGS WILL HANG OVER KBHK AND KMLS THIS MORNING...BUT
SHOULD LIFT BY LATE MORNING AS WEST TO NORTHWEST WINDS PICK UP.
LIGHT SNOW CONTINUES TO FALL AT KSHR AND MAY CONTINUE THROUGH THE
REST OF THE MORNING...KEEPING VISIBILITIES DOWN DUE TO BLOWING
SNOW. THE REST OF THE AREA WILL HAVE VFR FLYING CONDITIONS.
SOUTHWEST WINDS WILL GUST TO 25KTS AT KBIL AND KLVM. A FAST MOVING
SYSTEM FROM CANADA WILL PRODUCE AN INCREASING CHANCE OF SNOW
SHOWERS FOR LOCATIONS FROM KBIL WESTWARD THIS AFTERNOON AND
EVENING. THE BEST CHANCE OF SNOW SHOWERS WILL BE ALONG THE
FOOTHILLS AND OVER THE SOUTHWEST MOUNTAINS...WHERE CONDITIONS WILL
DROP TO LIFR WITH MOUNTAINS BECOMING OBSCURED. THE SNOW WILL TAPER
OFF OVERNIGHT. TWH/SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 027 007/022 010/035 027/040 023/035 022/034 016/029
4/J 41/N 11/E 11/E 32/J 12/J 12/J
LVM 025 001/021 017/041 035/041 023/034 025/033 016/030
7/J 70/N 22/W 12/W 32/J 23/J 22/J
HDN 030 005/024 902/034 022/041 022/034 016/035 012/028
6/J 31/B 00/E 11/E 32/J 12/J 12/J
MLS 027 008/022 902/025 019/040 020/036 017/034 015/027
2/J 11/B 00/B 11/E 32/J 12/J 12/J
4BQ 026 009/023 002/029 021/041 021/034 017/036 016/030
2/J 21/B 00/B 11/B 22/J 12/J 12/J
BHK 024 007/022 901/023 015/040 018/034 014/033 015/026
1/N 11/B 10/B 11/B 22/J 11/E 11/B
SHR 028 005/024 007/036 022/041 020/035 016/035 014/030
4/J 50/B 11/E 11/B 32/J 12/J 22/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL MIDNIGHT MST TONIGHT
FOR ZONE 56.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
413 PM EST WED DEC 16 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL APPROACH THE CAROLINAS FROM THE WEST
TONIGHT AS MOISTURE OVERSPREADS THE REGION. THE FRONT WILL CROSS THE
REGION THURSDAY WITH MUCH COLDER AIR SETTLING IN BEHIND THE SYSTEM
FOR FRIDAY AND LINGERING THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 400 PM EST WEDNESDAY...REALLY NO SIG CHANGES NEEDED TO THE
FCST GIVEN THE RECENT PACKAGE ISSUANCE AS CONDITIONS REMAIN IN
LINE. THAT SAID...DID SEE THE NEED TO TWEAK WINDS A BIT OVER THE
NC/SC PIEDMONT WHERE FLOW HAS VEERED SOUTH OF EAST THEREFORE BLENDED
IN THE LATEST RAP WHICH COMPLIMENTED WELL. OTHERWISE...LOW/MID VFR
STRATUS CONTINUES TO INFILTRATE THE NC HIGH TERRAIN ASSOCIATED
WITH PRIMARY FRONTAL AXIS TO THE WEST OVER THE MS VALLEY...WHILE
TEMPS REMAIN IN THE UPPER 60S TO LOWER 70S REGIONWIDE.
PREVIOUS DISCUSSION...
AS OF 230 PM...STILL REMARKABLY CLEAR ACROSS THE WESTERN CAROLINAS
AT MID-AFTERNOON...BUT AN AREA OF PRECIP CONTINUES TO APPROACH
FROM SOUTHEAST AL/SOUTHWEST GA. CLOUDS WILL INCREASE QUICKLY FROM
THE SW LATE THIS AFTERNOON...BUT THE LEADING EDGE WILL ONLY REACH
NEAR THE SAVANNAH RIVER BY SUNSET.
BIG CHANGES ARE IN STORE OVERNIGHT AS THE COLD FRONT CURRENTLY
RUNNING ALONG THE MS RIVER MAKES STEADY PROGRESS EASTWARD. MOISTURE
WILL SURGE NWD FROM THE GULF THIS EVENING AS A WEAK WARM FRONT MOVES
INLAND. LOW LEVEL ISENTROPIC UPGLIDE WILL INCREASE QUICKLY AFTER 06Z
AS A SERIES OF SHORT WAVES LIFT NE FROM THE UPPER TROF OVER THE SRN
PLAINS. THIS SHOULD AID IN THE DEVELOPMENT OF PRECIP FROM SW TO NE
ACROSS NEARLY THE ENTIRE FCST AREA BY 12Z THURSDAY. PRECIP CHANCES
INCREASE FROM THE SW IN KIND MAINLY AFTER MIDNIGHT AS THE BETTER
LOW LEVEL FORCING DEVELOPS...TO THE POINT WHERE A CATEGORICAL POP IS
A GOOD BET. PEOPLE WILL WAKE UP THURSDAY MORNING TO MUCH DIFFERENT
LOOKING WEATHER COMPARED TO TODAY...ALTHO TEMPS WILL STILL BE MILD.
ON THURSDAY...THE OPERATIONAL MODELS SHOW A SURFACE WAVE (OR WAVES)
LIFTING NE ALONG THE EWD MOVING COLD FRONT...WITH THE PRIMARY LOW
MOVING E OF THE MTNS. THIS BRINGS TO MIND A NUMBER OF POTENTIAL
PROBLEMS. A LOW LEVEL JET WILL STRENGTHEN FROM THE SW DURING THE DAY
E OF THE MTNS. THE ORIENTATION NOT-QUITE NORMAL TO THE BLUE RIDGE
MIGHT CUT DOWN ON SOME PRECIP POTENTIAL. THE QPF...TAKEN FROM WPC...
LOOKS DECENT...BUT SHOULD NOT BE QUITE ENOUGH TO CAUSE SIGNIFICANT
FLOODING NOW THAT STREAM FLOWS HAVE RETURNED CLOSE TO NORMAL AND FFG
HAS ALSO IMPROVED. A FLOOD WATCH WILL NOT BE ISSUED AT THIS TIME.
THE MODELS DO NOT INDICATE THE WEAK HIGH TO THE NE AS BEING STRONG
ENOUGH TO MAINTAIN ANY COOL POOL E OF THE MTNS OUTSIDE OF PERHAPS
THE NRN FOOTHILLS. THE SURFACE BOUNDARY LIFTS WELL INTO THE WESTERN
CAROLINAS IN THE AFTERNON...AT LEAST TO I-85 OR SO...MEANING WE MAY
BE ABLE TO DESTABILIZE SUFFICIENTLY TO CONSIDER THUNDERSTORMS. THE
ENVIRONMENT WILL HAVE CONSIDERABLE SHEAR WHICH WILL HELP TO ORGANIZE
STORMS. THE TREND IN THE NAM IS FOR GREATER BUOYANCY...UPWARDS OF
500 J/KG REACHING THE SE FRINGE...MORE THAN ENOUGH TO WORRY ABOUT
CONVECTIVE LINES THAT WOULD PRODUCE WIND DAMAGE AND/OR BRIEF WEAK
TORNADOES. MEANWHILE...THE GFS HAS ALMOST NO BUOYANCY. HOWEVER...THE
LIMITING FACTOR MIGHT BE THAT WE LACK A STRONG ADVECTIVE VORT CENTER
AND STRONG MID-LEVEL DRYING AS HAS BEEN NOTED IN OTHER SIMILAR
SITUATIONS THAT PRODUCED SEVERE WEATHER. THE DAY2 OUTLOOK FEATURES
A MARGINAL RISK PLACED TO THE SE...WHICH LOOKS GOOD FOR THE TIME
BEING. THIS WILL HAVE TO BE MONITORED CLOSELY ON THURSDAY AFTERNOON.
TEMPS WILL BE ABOVE NORMAL AGAIN.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
AS OF 215 PM...CHANCES FOR CONVECTION WILL LINGER ACROSS THE
SOUTHEAST ZONES FOR ABOUT THE FIRST COUPLE OF HOURS OF THE FORECAST
PERIOD. COLD AND DRY AIR ADVECTION WILL END THE PRECIP CHANCES
THROUGHOUT THE OVERNIGHT HOURS THU NIGHT/EARLY FRI ACROSS MUCH OF
THE AREA. SOME TOKEN SMALL POPS WILL BE CARRIED ALONG THE TENN
BORDER DURING THIS TIME...BUT IT APPEARS MOISTURE WILL QUICKLY
BECOME TOO SHALLOW FOR UPSLOPE SHOWER GENERATION...AT LEAST UNTIL
LATER IN THE DAY FRIDAY.
SPEAKING OF WHICH...THE INGREDIENTS LOOK QUITE A BIT MORE PROMISING
FOR ACCUMULATING NW FLOW SNOWFALL LATE FRIDAY INTO FRI NIGHT...IN
ADVANCE OF SECONDARY SHORT WAVE TROUGH DIGGING INTO THE AREA FROM
THE OHIO VALLEY. DURING THAT TIME...THE DEPTH OF THE MOIST LAYER
INCREASES TO ABOVE 800 HPA. THE THERMAL STRUCTURE IS ALSO QUITE
IMPRESSIVE...AS COLD AS -12C AT THE TOP OF THE MOIST LAYER. THIS IS
CERTAINLY FAVORABLE FOR ACCUMULATING SNOW SHOWERS. HOWEVER...THE BIG
LIMITING FACTOR IS THE BACKED NATURE OF THE LOW LEVEL FLOW DEPICTED
IN GUIDANCE...MORE W/NW IN NATURE THAN A PURE NW FLOW.
ADDITIONALLY...THE INGREDIENTS ARE NOT IN PLACE VERY LONG...ONLY FOR
6 HOURS OR SO. ALL TOLD...THIS PROBABLY DOESN/T EVEN QUALIFY AS AN
ADVISORY-LEVEL EVENT...ALTHOUGH SOME OF THE HIGHER NORTHERN MTN
PEAKS ALONG THE TENN BORDER WILL PROBABLY SEE A COUPLE OF INCHES.
THE REMAINDER OF THE SHORT TERM PERIOD WILL BE DOMINATED BY THE
EFFECTS OF A COOL LONG WAVE TROUGH AND UPSTREAM CANADIAN SURFACE
HIGH...YIELDING BELOW NORMAL TEMPS AND A VERY DRY AIR MASS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...NORTHWEST FLOW WILL BE IN PLACE AT
THE START OF THE EXTENDED WITH A LOW-AMPLITUDE WAVETRAIN OVER
THE EASTERN 2/3 OF THE COUNTRY...IN THE WAKE OF THE EARLIER
FRONT. SURFACE HIGH PRESSURE WILL DOMINATE THE SOUTHEAST AS RIDGING
BEGINS TO INCREASE DURING THE DAY ON SUNDAY. EXPECT NEAR TO JUST
SLIGHTLY BELOW NORMAL TEMPERATURES WITH NO POPS AND NOT MUCH IN
THE WAY OF CLOUDS TO START THE PERIOD.
AS THE SURFACE HIGH PRESSURE LIFTS NORTHEAST...WINDS WILL SWING
BACK AROUND TO THE SOUTH AND SOUTHWEST...BRINGING A RETURN OF
MOISTURE TO THE AREA. SHORTWAVE CROSSING THE NORTHERN TIER OF THE
COUNTRY WILL TAKE A SURFACE LOW ACROSS THE GREAT LAKES...WITH A
COLD FRONT SWEEPING THROUGH THE MISSISSIPPI VALLEY AND APPROACHING
THE SOUTHERN APPALACHIANS EARLY MONDAY. GFS IS A LITTLE MORE ROBUST
WITH THE FRONT /ECMWF IS MORE OCCLUDED/ BUT GOOD ENOUGH AGREEMENT
IN SENSIBLE WEATHER IMPACTS BETWEEN THE TWO. CLOUDS WILL INCREASE
FROM THE WEST SUNDAY NIGHT INTO EARLY MONDAY...WITH PRECIPITATION
ENTERING THE MOUNTAINS BY AROUND 12Z MONDAY. TIMING OF INCOMING
CLOUD COVER VS OVERNIGHT LOWS WILL BE TRICKY FOR SURE...FOR NOW
THINK THAT CLOUDS WILL INCREASE EARLY ENOUGH TO KEEP TEMPS JUST
ABOVE FREEZING SO AM NOT INCLUDING ANY WINTRY PRECIP AT THIS
TIME...BUT WILL NEED TO KEEP A CLOSE EYE ON SUBSEQUENT RUNS AND
TIMING OF INCOMING MOISTURE OVER THE NEXT COUPLE OF DAYS.
THIS INITIAL WAVE WILL PUSH THROUGH DURING THE DAY ON SUNDAY...WITH
A SECONDARY SHORTWAVE DIVING OUT OF CANADA MONDAY NIGHT INTO
EARLY TUESDAY. A SLUG OF MOISTURE COMING OUT OF THE GULF WITH THE
SOUTHWEST FLOW ALOFT WILL OVERSPREAD THE DEEP SOUTH AND SOUTHEAST
DURING THE DAY ON TUESDAY...WITH ALL GUIDANCE POINTING TO THE
POTENTIAL FOR WIDESPREAD RAIN. GIVEN HOW FAR OUT THIS IS...HAVE
GONE HIGH CHANCE TO LOW LIKELY POPS DESPITE BLENDS INDICATING
CATEGORICAL. TROUGH DEEPENS OVER THE PLAINS TUESDAY NIGHT INTO
WEDNESDAY WITH CONTINUED MOISTURE FETCH FROM THE GULF OVER THE
SOUTHEAST.
AFTER WEDNESDAY...OPERATIONAL MODELS DIVERGE WITH ECMWF PUSHING
THE FRONT THROUGH BY THURSDAY 00Z AND THE GFS WITH A REINFORCING
SHORTWAVE COMING AROUND THE TROUGH...AND NOT CLEARING THE AREA
OUT UNTIL CLOSER TO 00Z FRIDAY. HOWEVER...THE CONCERN WITH BOTH
MODELS IS THE AMOUNT OF WAA AND INCREASING CAPE AHEAD OF THE FRONTAL
PASSAGE. AS ALREADY STATED...TIMING IS PRETTY DIFFERENT ON THE TWO
MODELS WHICH CERTAINLY DOESN`T LEND MUCH CONFIDENCE BUT THE OVERALL
PATTERN IS ACTUALLY PRETTY SIMILAR. TAKING THE GFS FOR EXAMPLE AT
12Z THURSDAY /VERY END OF THE NEW DAY 7/ GFS HAS BETWEEN 200-500
J/KG SBCAPE WITH 50-80KT 0-6KM SHEAR. DEFINITELY TOO EARLY TO TRY
TO PIN DOWN ANY SIGNIFICANT TO SEVERE WEATHER POTENTIAL BUT HAVE
INTRODUCED THUNDER INTO THE GRIDS...AND WILL CONTINUE TO REFINE
THIS IN SUBSEQUENT RUNS.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...VFR THROUGH THE EVENING HOURS...WITH A LIGHT ENE WIND
BECOMING ESE PROBABLY CLOSER TO MIDNIGHT. THINGS WILL GO QUICKLY
DOWNHILL FROM THERE. BEST INDICATIONS ARE THAT LOW CLOUDS SEEN ON
SATELLITE IMAGERY OVER S AL/SW GA WILL LIFT NE ACROSS THE NC
PIEDMONT BY LATE TONIGHT...FOLLOWED BY PRECIP ARRIVAL IN SHORT
ORDER. VISIBILITY MAY DROP FIRST WITH FOG DEVELOPMENT AS LOW LEVEL
MOISTURE INCREASES...BUT ONCE PRECIP MOVES IN THE CEILING WILL DROP
THROUGH MVFR AND INTO IFR RANGE IN THE 09Z TO 15Z TIME FRAME. ALTHO
THE LAMP AND NAM SHOW THIS...IT IS BY NO MEANS CERTAIN...BUT STILL
THE MOST LIKELY OUTCOME AND THUS INCLUDED AS THE PREVAILING
CONDITION...IFR AFTER 15Z. WIND WILL VEER MORE TOWARD THE SE AND LOW
LEVEL WIND SHEAR WILL INCREASE AS A LOW LEVEL JET AXIS MOVES IN FROM
THE W. THUNDERSTORM CHANCES INCREASE AFTER 18Z.
ELSEWHERE...ESSENTIALLY THE SAME PROGRESSION AS KCLT...BUT EARLIER
AS THE CLOUDS/PRECIP SPREAD UP FROM THE SW. CONFIDENCE ALSO LOW AS
MODEL GUIDANCE SHOWS QUITE A BIT OF SPREAD IN TERMS OF CEILING/VIS.
MOST LIKELY OUTCOME WILL BE FOR A PERIOD OF IFR WITH LOW MVFR HOLES
FROM 13Z ONWARD. COULD HAVE LLWS AT ALL TAF SITES AS THE LOW LEVEL
JET STREAK MOVES OVERHEAD FROM SUNRISE ONWARD.
OUTLOOK...FLIGHT RESTRICTIONS WILL CONTINUE THROUGH THE AFTERNOON
AND INTO THE EARLY EVENING THURSDAY. DRY AIR WILL RETURN THURSDAY
NIGHT. CONDITIONS SHOULD BE VFR THRU THE WEEKEND COURTESY OF
SURFACE HIGH PRESSURE.
CONFIDENCE TABLE...
21-03Z 03-09Z 09-15Z 15-18Z
KCLT HIGH 100% HIGH 100% MED 77% HIGH 87%
KGSP HIGH 100% HIGH 100% MED 71% HIGH 84%
KAVL HIGH 100% HIGH 85% HIGH 86% HIGH 84%
KHKY HIGH 100% MED 77% HIGH 85% HIGH 89%
KGMU HIGH 100% HIGH 100% MED 75% HIGH 84%
KAND HIGH 100% HIGH 100% HIGH 94% HIGH 87%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...CDG/PM
SHORT TERM...JDL
LONG TERM...TDP
AVIATION...PM
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
305 PM EST WED DEC 16 2015
.SHORT TERM (TONIGHT THROUGH TOMORROW)...
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A
NEGATIVELY TILTED UPPER LEVEL LOW ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY WITH A RIDGE ALONG THE ATLANTIC SEABOARD. FURTHER TO THE
WEST...A POSITIVELY TILTED TROUGH IS PIVOTING ACROSS THE DESERT
SOUTHWEST. AT THE SURFACE...A COLD FRONT IS CURRENTLY ALONG THE
MISSISSIPPI RIVER WITH A SECONDARY WARM FRONT ALONG THE GULF COAST.
TEMPERATURES TODAY HAVE BEEN MUCH WARMER THAN NORMAL WITH HIGHER
HEIGHTS ALOFT AND CONTINUED SOUTHERLY TO SOUTHWESTERLY FLOW
THROUGHOUT THE ATMOSPHERE. IN FACT...KTRI JUST REACHED 70
DEGREES...WHICH IS 2 DEGREES ABOVE THE RECORD HIGH FOR TODAY.
PW VALUES WILL CONTINUE TO RISE WITH VALUES CLIMBING UP INTO THE 1.3-
1.5 INCH RANGE LATER TONIGHT...WHICH IS NEAR THE MAXIMUM VALUES
OBSERVED FOR MID-DECEMBER. CURRENT RADAR IMAGERY INDICATES THAT THE
AREA OF PRECIPITATION MOVING INTO NASHVILLE IS BREAKING APART AS IT
MOVES OUT WELL AHEAD OF THE FRONT. HOWEVER...HI-RES MODELS INDICATE
THAT LATER TONIGHT THE LOW LEVEL JET WILL INCREASE TO 35-45 KTS
BRINGING IN THE HIGH PW AIR IN AS THE FRONT MOVES EASTWARD ACROSS
THE TENNESSE VALLEY. A SECONDARY LOW IS FORECAST TO DEVELOP LATER
THIS AFTERNOON AND EVENING ALONG THE WARM FRONT TO THE SOUTH. THIS
LOW WILL RACE TO THE NORTHEAST OVERNIGHT INTO TOMORROW ACROSS
ALABAMA AND GEORGIA BUT SHOULD STAY TO THE SOUTH OF THE FORECAST
AREA. REGARDLESS...STRONG ISENTROPIC LIFT TO THE NORTH OF THIS WARM
FRONT WILL AID IN PRECIPITATION DEVELOPMENT AFTER MIDNIGHT. MODEL
SOUNDINGS ALSO INDICATE AN INVERSION JUST ABOVE THE SURFACE. LAPSE
RATES ABOVE THIS INVERSION ARE STEEP ENOUGH TO SUPPORT MUCAPE
VALUES IN THE 100-200 J/KG RANGE. DUE TO THIS...WENT AHEAD AND
MENTIONED THUNDER IN THE FORECAST OVERNIGHT MAINLY FOR THE SOUTHERN
HALF OF THE AREA. GENERALLY LOOKING AT RAINFALL AMOUNTS OF 1-2
INCHES WITH THE POSSIBILITY OF SOME LOCALLY HIGHER AMOUNTS. EXPECT
THE HIGHEST VALUES WILL BE ACROSS EXTREME SOUTHWEST NORTH CAROLINA
AND SOUTHEAST TENNESSEE. IN THESE LOCATIONS...SOME MINOR FLOODING
WILL BE POSSIBLE DURING THE OVERNIGHT HOURS INTO TOMORROW. IT
APPEARS THAT STREAM AND RIVER LEVELS HAVE RETURNED TO NORMAL FLOW
AFTER THE RAINS EARLY THIS WEEK. FOR NOW...WILL FORGO ISSUING A
FLOOD WATCH AND CONTINUE THE MENTION OF LOCALIZED FLOODING IN THE
HWO BUT WILL HAVE TO REEVALUATE THINGS LATER THIS EVENING.
THE COLD FRONT WILL MOVE THROUGH THE AREA QUICKLY TOMORROW WITH RAIN
CHANCES COMING TO AN END FROM WEST TO EAST. TEMPERATURES WILL HOLD
IN THE 50S FOR MUCH OF THE DAY FALLING INTO THE 40S BY THE
AFTERNOON.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...
EXTENDED FORECAST LOOKS GOOD WITH A BRIEF PERIOD OF COLDER AIR
WITH TEMPERATURES ACTUALLY A FEW DEGREES BELOW NORMAL FOR MID
DECEMBER. A TRAILING SHORT WAVE BUILDS ACROSS THE MIDWEST WITH SOME
ASSOCIATED MOISTURE. THERE MAY BE JUST ENOUGH MOISTURE ALONG WITH
SUB-FREEZING AIR FOR A FEW SNOW SHOWERS IN THE HIGHER TERRAIN OF
SOUTHWEST VIRGINIA AND NORTHEAST TENNESSEE...MAINLY ABOVE THREE
THOUSAND FEET...LATE THURSDAY NIGHT THROUGH FRIDAY. I DON`T EXPECT
MUCH IN THE WAY OF ACCUMULATION WITH A TENTH OF AN INCH COMMON MOST
HIGHER ELEVATION SPOTS...UP TO MAYBE A HALF AN INCH AT LECONTE. THE
COLD AIR HANGS AROUND FOR FRIDAY AND SATURDAY BUT MORE BEAUTIFUL
AMPLIFICATION DEVELOPS OVER THE NATION DURING THE WEEKEND WITH MORE
WESTERN U.S. TROUGHING COMBINED WITH EASTERN STATES RIDGING. THE
PREVAILING SOUTHWEST FLOW BRINGS MILDER AIR WITH HIGHS BACK IN THE
50S SUNDAY AND MONDAY ALONG WITH TOASTY LOWER AND MIDDLE 60S DEGREE
MAX TEMPS POSSIBLE TUESDAY AND WEDNESDAY. THE WARM SOUTHERLY FLOW
EVENTUALLY PULLS ENOUGH MOIST AIR INTO THE REGION WITH AT LEAST A
COUPLE RIPPLES OF SHORT WAVE ENERGY FOR THE PRODUCTION OF SHOWERS
DURING THE FIRST HALF OF THE WORK WEEK. SUPER BLEND APPLIES
INCREASING PROBABILITY OF PRECIPITATION TUESDAY INTO WEDNESDAY AS A
COLD FRONT APPROACHES THROUGH THE MISSISSIPPI VALLEY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 52 56 34 48 / 100 80 10 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 52 54 34 44 / 100 100 10 10
OAK RIDGE, TN 51 54 33 45 / 100 100 10 10
TRI CITIES AIRPORT, TN 50 54 35 41 / 100 100 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA