Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/15/16
AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
1022 PM PST FRI FEB 12 2016
.SYNOPSIS...
A WEAK UPPER LEVEL TROUGH PASSING TO THE NORTH WILL PROVIDE A BRIEF
BREAK FROM THE RECORD HEAT THIS WEEKEND. A BUILDING RIDGE ALOFT
AND GUSTY OFFSHORE WINDS BRING A RETURN OF RECORD HEAT EARLY NEXT
WEEK. A SECOND UPPER LEVEL LOW WILL SUPPORT MUCH COOLER CONDITIONS
WITH THE CHANCE OF RAIN LATE WEDNESDAY INTO THURSDAY.
&&
.SHORT TERM...(FRI-MON)
UPPER LEVEL TROUGH MOVING INTO NORTHERN CALIFORNIA TONIGHT WITH
RIDGE AXIS SLIDING WELL EAST OF OUR AREA. THIS HAS RESULTED IN
SLIGHT ONSHORE TRENDS THIS EVENING...WITH CURRENT LAX-DAGGETT
GRADIENT AT -1.9 MB. SATELLITE IMAGERY SHOWING AREAS OF LOW
CLOUDS AND DENSE FOG ACROSS PORTIONS OF THE COASTAL WATERS
(WHICH WAS HIGHLIGHTED WITH A MARINE WEATHER STATEMENT)...LOCALLY
EXTENDING INTO THE CENTRAL COAST THIS EVENING. MOST OF THE FOG
OFFSHORE OF LOS ANGELES COUNTY IS FORMING NEAR CATALINA ISLAND
AND THE SAN PEDRO CHANNEL. BUT CONDITIONS ARE COMING TOGETHER FOR
SOME PATCHY DENSE FOG JUST ABOUT ANYWHERE ALONG THE IMMEDIATE
COAST TONIGHT...AND HAVE INCLUDED THAT IN ZONE UPDATE. COMBINATION
OF SHALLOW/STRONG MARINE INVERSION...WEAKENING PRESSURE
GRADIENTS...AND COASTAL DEWPOINTS RISING INTO THE MID 50S IS
REASONING FOR POTENTIAL DENSE FOG ALONG IMMEDIATE COAST.
AS THE TROUGH MOVES INLAND ON SATURDAY...THERE IS SOME INCREASING
NORTHERLY FLOW SETTING UP ACROSS THE FORECAST AREA...ESPECIALLY
TOMORROW NIGHT. INLAND AREAS NOT SHOWING A WHOLE LOT OF COOLING
ON SATURDAY AT 950 MB LEVEL...SO BUMPED UP MOST VALLEY
TEMPERATURES A FEW DEGREES IN EVENING UPDATE. TAKING A GLANCE
AT THE 00Z NAM MODEL...SEEING ANOTHER RESURGENCE OF OFFSHORE
FLOW FROM SUNDAY THROUGH TUESDAY WITH UPPER LEVEL RIDGE REBUILDING
OVER THE AREA. STILL LOOKING LIKE STRONGEST OFFSHORE WIND PUSH
WILL BE SUNDAY NIGHT INTO MONDAY WITH WIDESPREAD ADVISORIES
LIKELY ACROSS VENTURA AND LOS ANGELES COUNTIES. WITH PROJECTED
LAX-DAGGETT GRADIENT APPROACHING -7 MB ON SUNDAY MORNING AND
SOME UPPER LEVEL WIND/THERMAL SUPPORT...COULD SEE SOME ISOLATED
WIND GUSTS UP TO 60 MPH IN THE FAVORED MOUNTAIN AREAS. THE
OFFSHORE WINDS WITH LOW HUMIDITIES AND WARM TEMPERATURES WILL
BRING ANOTHER ROUND OF ELEVATED FIRE DANGER SUNDAY THROUGH
TUESDAY. THE OTHER BIG STORY WILL CONTINUE TO BE THE UNUSUALLY
HOT TEMPERATURES EXPECTED SUNDAY THROUGH TUESDAY...WITH MANY
COASTAL/VALLEY AREAS EXPECTED TO CLIMB WELL INTO THE 80S AND LOWER
90S. ON SUNDAY...COULD SEE A COUPLE OF RECORDS BROKEN THEN
EVEN BETTER CHANCE OF RECORDS BEING SET ON MONDAY AND TUESDAY.
.LONG TERM...(TUE-FRI)
FOR THE EXTENDED...12Z MODELS START OUT IN DECENT SYNOPTIC
AGREEMENT...BUT DIVERGE LATER IN THE PERIOD. AT UPPER LEVELS
RIDGE WILL LINGER ON TUESDAY THEN A TROUGH WILL APPROACH AND MOVES
ACROSS THE WEST COAST WEDNESDAY THROUGH FRIDAY. NEAR THE SURFACE
WEAK OFFSHORE FLOW WILL PREVAIL ON TUESDAY THEN SHIFT TO ONSHORE
WEDNESDAY THROUGH FRIDAY.
FORECAST-WISE...TUESDAY WILL BE AN UNREMARKABLE DAY WITH CLEAR
SKIES...LIGHT OFFSHORE BREEZES AND HIGH TEMPERATURES WELL ABOVE
NORMAL. FOR WEDNESDAY AND THURSDAY...THE MODELS DIVERGE NOTICEABLY
LEADING TO A LOW CONFIDENCE FORECAST. THE ECMWF MOVES A TROUGH
ACROSS THE AREA WEDNESDAY/THURSDAY AND GENERATES A DECENT RAIN
EVENT FOR THE AREA. CONVERSELY...THE GFS IS MUCH LESS BULLISH WITH
THIS TROUGH...HARDLY SPITTING OUT ANY PRECIPITATION. WITH SUCH
MODELS DIFFERENCES...WILL NOT DEVIATE FROM PREVIOUS FORECAST
THINKING WHICH INCLUDED CHANCE/SLIGHT CHANCE POPS FOR THE AREA
WEDNESDAY AND THURSDAY. HOPEFULLY...MODELS WILL COME INTO SOME
BETTER AGREEMENT OVER THE NEXT COUPLE OF DAYS. BY THURSDAY NIGHT
AND FRIDAY...BOTH MODELS PUSH TROUGH EAST OF THE AREA AND INDICATE
DRY CONDITIONS.
&&
.AVIATION...13/0600Z.
AT 0530Z...AT KLAX...THERE WAS A SURFACE BASED INVERSION LAYER TO
1700 FEET WITH A TEMP OF 24 DEG C.
FOR COASTAL TAF SITES INCLUDING KSMX & KPRB...LOW CONFIDENCE IN
THE 06Z TAFS THROUGH 16Z DUE THE POSSIBILITY OF FOG/LOW CLOUDS.
EXPECT IFR TO LIFR WITH LOCALIZED VLIFR IN AREAS WHERE FOG/LOW
CLOUDS DO DEVELOP. MODERATE TO HIGH CONFIDENCE FOR THE REMAINDER
OF THE TAF PERIOD.
INLAND TAF SITES...HIGH CONFIDENCE IN 06Z CAVU TAFS.
KLAX...LOW CONFIDENCE IN 06Z TAF THROUGH 16Z DUE TO THE
POSSIBILITY OF LOW FOG AND LOW CLOUDS. THERE IS A 40 PERCENT
CHANCE OF LIFR TO VLIFR CIGS/VSBYS DUE TO FOG/LOW CLOUDS THROUGH
16Z. MODERATE CONFIDENCE IN THE REMAINDER OF THE TAF PERIOD.
KBUR...HIGH CONFIDENCE IN 06Z CAVU TAF.
&&
.MARINE...12/800 PM...
A MARINE WEATHER STATEMENT WAS ISSUED THIS EVENING FOR THE
POSSIBILITY OF DENSE FOG FOR ALL AREAS THROUGH SATURDAY MORNING.
PLEASE SEE MWSLOX FOR DETAILS.
FOR THE OUTER WATERS...THERE IS HIGH CONFIDENCE IN SMALL CRAFT
ADVISORY (SCA) CONDITIONS THROUGH LATE SUNDAY NIGHT DUE TO EITHER
SCA WINDS OR A 10-13 FT...LONG PERIOD W-NW SWELL. THE STRONGEST
N-NW WINDS ACROSS THE OUTER WATERS ARE EXPECTED SATURDAY AFTERNOON
AND NIGHT...WHEN THERE COULD BE SOME LOCAL GALE FORCE WINDS. SCA
WINDS COULD LINGER INTO MONDAY...BUT SHOULD WEAKEN CONSIDERABLY BY
TUESDAY.
FOR THE INNER WATERS N OF PT CONCEPTION...THERE IS HIGH
CONFIDENCE IN SCA CONDITIONS FOR HAZARDOUS SEAS THROUGH SUNDAY
EVENING. THIS IS DUE TO THE 10-13 FT...LONG PERIOD W-NW SWELL.
WINDS WILL GENERALLY REMAIN BELOW SCA CRITERIA...THROUGH THE
FORECAST PERIOD...BUT THERE COULD BE SOME LOCAL N-NE GUSTS TO 25
KT SATURDAY EVENING THROUGH MONDAY EVENING.
FOR THE INNER WATERS S OF PT CONCEPTION...THERE IS GOOD CONFIDENCE
THAT WINDS AND SEAS WILL REMAIN BELOW SCA CRITERIA THROUGH SUNDAY
AFTERNOON. HOWEVER...SOME 10 FT SEAS ARE POSSIBLE IN WESTERN
PORTIONS OF THE SANTA BARBARA CHANNEL THROUGH SATURDAY
AFTERNOON...DUE TO THE LONG PERIOD SWELL. THERE IS ALSO A CHANCE
FOR SOME ISOLATED NE WIND GUSTS TO 25 KT ON SUNDAY MORNING BETWEEN
SANTA MONICA AND VENTURA. STRONGER NE WINDS ARE EXPECTED LATE
SUNDAY NIGHT INTO MONDAY...WHEN A SCA MAY BE NEEDED.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH SURF ADVISORY IN EFFECT UNTIL 9 AM PST SUNDAY FOR ZONES
34-35. (SEE LAXCFWLOX).
BEACH HAZARDS STATEMENT IN EFFECT THROUGH SUNDAY MORNING FOR
ZONE 39. (SEE LAXCFWLOX).
HIGH SURF ADVISORY IN EFFECT UNTIL NOON PST SUNDAY FOR ZONES
40-41-87. (SEE LAXCFWLOX).
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IN EFFECT UNTIL 9 PM
PST SUNDAY FOR ZONE 645. (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST MONDAY FOR
ZONES 670-673-676. (SEE LAXMWWLOX).
&&
$$
PUBLIC...GOMBERG
AVIATION...MUNROE/DB
MARINE...SUKUP
SYNOPSIS...MUNROE
WEATHER.GOV/LOSANGELES
Area Forecast Discussion
National Weather Service Sacramento CA
1015 PM PST FRI FEB 12 2016
.SYNOPSIS...
Dry and mild weather through early next week with well above
normal temperatures. Wetter and cooler weather pattern expected
middle to latter portion of next week.
&&
.DISCUSSION...
Upper trof moving through Norcal with weakening surface front. CI/CS
streaming into Interior NorCal is now sagging SEwd with upper trof.
Moisture profiles from BUFKIT show high cloudiness eroding/
dissipating around 12z at the TAF sites in the Srn Sac/Nrn SJV with
winds turning NW. This should limit/preclude widespread fog
production. Subjective analysis is the HRRR is likely hitting the )
VSBYS too hard in the Vly Sat morning...and believe the fog will not
be as dense or cover as much area as forecast. The patchy fog
wording currently in the zones should suffice. JHM
Heights and thicknesses progged to increase over the weekend as
upper ridge amplifies off the West Coast. High temperatures
forecast mainly in the lower 70s Saturday for the Central Valley,
which is upwards of 10 to 12 degrees above normal and at record
values for KSAC/KSCK. Some short lived patchy morning valley fog
will continue to be possible over the weekend from Sacramento
southward.
Another weak weather system rides over the ridge Sunday with some
light overrunning precip possible into far northern portions of
CA. However associated precip continues to be modeled north of
our forecast area. Surface high pressure building through Oregon
into the Great Basin will result in some locally breezy northerly
wind from Sunday afternoon into Monday. High temps expected to
slowly trend up over the weekend into Monday. Max Ts in the
Central Valley expected in the mid to upper 70s Sun/Mon with
readings continuing right around record values for the Sacramento
and Stockton areas.
PCH
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
Conditions will remain dry through Tuesday. On Wednesday, NorCal
transitions into a wet pattern as a trough impacts the west coast.
Both the GFS & ECMWF models agree that this storm will start
impacting our region by Wednesday evening. However, the challenge
with this system is that the models disagree on the details. The
GFS shows a quickly moving trough that weakens by Thursday
morning and puts our region back into a dry, ridging pattern by
Thursday afternoon/evening. The ECMWF indicates a stronger,
wetter trough that keeps a threat of precipitation in our CWA
through Thursday evening. Have medium confidence that interior
NorCal will get light to moderate rain/snow Wednesday evening into
Thursday afternoon with snow levels around 5000 ft.
The models continue to diverge on Friday with the GFS maintaining
a dry ridge while the ECMWF brings in another wave of
precipitation that impacts area north of Interstate 80. Confidence
is lower, but have kept lingering chances of precipitation
through Friday until models come into better agreement.
JBB
&&
.AVIATION...
SWly flow alf vrg to NWly Sat. Vrbl clds AOA FL120 for Intr NorCal
nxt 24 hrs with VFR conds exc isold MVFR/IFR/LIFR poss in Srn
Sac/Nrn San Joaquin vlys in BR/FG btwn 10z-18z Sat.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
652 PM MST SUN FEB 14 2016
.UPDATE...
ISSUED AT 652 PM MST SUN FEB 14 2016
UPSTREAM IN SOUTHWESTERN WYOMING SNOWED HAS STOPPED FOR NOW AS
THE BULK OF ENERGY HAS MOVED DOWNSTREAM ALONG THE CONTINENTAL
DIVIDE AREAS OF CENTRAL COLORADO. ALLOWED WINTER WEATHER
ADVISORIES TO CONTINUE THROUGH TOMORROW DESPITE THE OBVIOUS BREAK
IN SNOWFALL...WHICH HAS ALREADY BEGUN AROUND THE STEAMBOAT SPRINGS
AREA AND WILL SOON BEGIN IN THE FLATTOPS. THE SHORT TERM MODELS
ARE INDICATING THE BREAK TO LAST THROUGHOUT THE NEXT 6 TO 12
HOURS...BUT SNOW PICKING UP TOWARD DAYBREAK FROM THE NORTHWEST
AGAIN. TOMORROW/S SNOW IS STILL LOOKING MORE OROGRAPHICALLY
DRIVEN AS OPPOSED TO TODAY/S DISTURBANCE WHICH ALLOWED SNOWFALL
ALONG THE LOWER ELEVATIONS OF NORTHWEST COLORADO ALONG THE
FOOTHILLS OF THE MOUNTAINS.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 306 PM MST SUN FEB 14 2016
A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS
AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM
IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED
INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS
EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION
THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF
THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND
INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM
GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON.
BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT
BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE
PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS
EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL
LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND
ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH
THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL
PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL
LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70
CORRIDOR...AND ROARING FORK VALLEY.
UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED
WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP
NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW
IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING
SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS
AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE
THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH
ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE
NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE
GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS
AND PULL DOWN EARLY IF NEEDED.
THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS
SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE
SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 306 PM MST SUN FEB 14 2016
BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES
INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN
CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS
MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE
THEIR WARM TREND FOR A NICE START TO THE WORK WEEK.
STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF
LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP
TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW
FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE
EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS
THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS
THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED
WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS
SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE
DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO
EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL
MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET
ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER
PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE
MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM.
AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY
BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS
EASTWARD.
EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS
THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO
REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 417 PM MST SUN FEB 14 2016
SNOW SHOWERS CONTINUE TO IMPACT AREAS OF WESTERN COLORADO FROM
RABBIT EARS PASS SOUTH TO VAIL PASS. ANOTHER AREA OF SNOW WILL
IMPACT KEGE AND KASE THROUGH ABOUT 04Z. CONDITIONS WILL IMPROVE
BY 06Z AT MANY LOCATIONS...STRONG NW WINDS AT AND ABOVE MTN TOP
LEVEL WILL CONTINUE THROUGH ABOUT 12Z. AFTER 12Z SNOW WILL BE
LIMITED TO THE MTNS ALONG AND NORTH OF VAIL PASS INTO WYOMING.
BREEZY CONDITIONS WITH GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE
DAY MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR
COZ004-005-013.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...JOE/TGR
LONG TERM...TGR
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
430 PM MST SUN FEB 14 2016
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 306 PM MST SUN FEB 14 2016
A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS
AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM
IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED
INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS
EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION
THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF
THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND
INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM
GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON.
BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT
BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE
PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS
EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL
LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND
ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH
THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL
PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL
LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70
CORRIDOR...AND ROARING FORK VALLEY.
UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED
WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP
NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW
IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING
SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS
AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE
THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH
ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE
NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE
GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS
AND PULL DOWN EARLY IF NEEDED.
THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS
SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE
SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 306 PM MST SUN FEB 14 2016
BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES
INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN
CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS
MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE
THEIR WARM TREND FOR A NICE START TO THE WORK WEEK.
STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF
LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP
TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW
FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE
EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS
THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS
THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED
WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS
SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE
DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO
EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL
MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET
ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER
PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE
MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM.
AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY
BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS
EASTWARD.
EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS
THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO
REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 417 PM MST SUN FEB 14 2016
SNOW SHOWERS CONTINUE TO IMPACT AREAS OF WESTERN COLORADO FROM
RABBIT EARS PASS SOUTH TO VAIL PASS. ANOTHER AREA OF SNOW WILL
IMPACT KEGE AND KASE THROUGH ABOUT 04Z. CONDITIONS WILL IMPROVE
BY 06Z AT MANY LOCATIONS...STRONG NW WINDS AT AND ABOVE MTN TOP
LEVEL WILL CONTINUE THROUGH ABOUT 12Z. AFTER 12Z SNOW WILL BE
LIMITED TO THE MTNS ALONG AND NORTH OF VAIL PASS INTO WYOMING.
BREEZY CONDITIONS WITH GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE
DAY MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR
COZ004-005-013.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010.
UT...NONE.
&&
$$
SHORT TERM...JOE/TGR
LONG TERM...TGR
AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 AM EST SAT FEB 13 2016
.SYNOPSIS...
AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION OVERNIGHT WITH
ISOLATED TO SCATTERED SNOW SHOWERS AHEAD OF IT. BEHIND THE ARCTIC
COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS
THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND
WIND CHILLS. A STORM SYSTEM MAY IMPACT THE REGION MONDAY INTO THE
MID WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1235 AM EST...AN ARCTIC COLD FRONT WAS POSITIONED JUST
NORTH AND WEST OF THE FORECAST AREA AND POISED TO MOVE SOUTHWARD
THROUGH THE OVERNIGHT HOURS. THE FRONT WILL BE MOVING THROUGH THE
REGION BETWEEN 1 AM AND 6 AM FROM NW TO SE. AHEAD OF THIS FRONTAL
BOUNDARY THERE WILL BE ISOLATED TO SCATTERED SNOW
SHOWERS...ALTHOUGH THE INTENSITY AND COVERAGE OF SNOW SHOWERS HAS
DECREASED OVER THE PAST FEW HOURS REMOVED FROM THE MOISTURE SOURCE
/LAKE ONTARIO/. THE LATEST 3-KM HRRR SHOWS SNOW SHOWERS WEAKENING
AS THEY TRACK SOUTHEASTWARD THROUGH THE AREA ASSOCIATED WITH THE
BOUNDARY. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE
WITH GENERALLY A DUSTING TO 2 INCHES. THE HIGHER TOTALS WILL BE
OVER THE WRN DACKS.
IT WILL BE ANOTHER VERY COLD NIGHT...BUT NOT AS COLD AS
TEMPERATURES WILL BE LATER IN THE WEEKEND. LOWS OVERNIGHT WILL
RANGE FROM 10 BELOW ZERO NORTHWEST AREAS TO 15 ABOVE ZERO
SOUTHEAST TOWARDS NW CT AND THE MID HUDSON RIVER VALLEY. WINDS
WILL ALSO INCREASE OVERNIGHT ACROSS THE FCST AREA WITH A WIND
CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN
ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND
SOUTHERN VERMONT. THE JAIL BREAK OF ARCTIC AIR KICKS IN...AS THE
WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO
20 MPH WITH GUSTS TO 30-40 MPH.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL
OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND.
THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND
IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE
SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34
DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON-
DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND
THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING
ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO
15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE
ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE
FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH
WITH GUSTS 30 TO 40 MPH.
SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE
EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL
VALUES 25 BELOW TO NEAR 50 BELOW ZERO.
SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION
ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS
WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING
LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE
ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10
BELOW AND 5 ABOVE ZERO.
MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO
TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE
ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S
SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA
LATE IN THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE
EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE
AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS
EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY
NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT
THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS
PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS
THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE
TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA
THROUGH ALBANY.
BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO
GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL
LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY
OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW
TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT
ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT
NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY.
BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE
DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR
MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR
WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS
HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE
EXPECTING THIS WEEKEND.
HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE
UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON
WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY.
FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT
WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN
THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM
THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE
HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND
THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW
SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN
THE MID HUDSON VALLEY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A CLIPPER LOW WILL PASS NORTH OF THE REGION THROUGH THE EARLY
MORNING HOURS...AS THE ASSOCIATED ARCTIC COLD FRONT TRACKS THROUGH.
A NW FLOW OF ARCTIC AIR WILL IMPACT THE REGION THROUGH THE DAY INTO
THE NIGHT PERIOD WITH GUSTY WINDS.
THE ARCTIC FRONT WILL FOCUS SOME ISOLATED TO SCATTERED SNOW SHOWERS
OR A SQUALL FROM THE CAPITAL REGION NORTH...IMPACTING KGFL/KALB/KPSF
BETWEEN 04Z-09Z. THE SNOW SHOWERS WILL BE FAIRLY ISOLATED TO
SCATTERED IN COVERAGE DUE TO VERY LIMITED LOW-LEVEL MOISTURE. A VCSH
WAS USED AT KALB/KPSF/KGFL THROUGH ABOUT 10-11Z.
VFR CONDITIONS WILL BE DOMINATE...ASIDE FOR SOME MVFR CIGS/VSBYS
WITH ANY SNOW SHOWERS/ISOLD SQUALLS ESPECIALLY AT KPSF/KGFL. CIGS
WILL BE MAINLY IN THE 4-9 KFT AGL RANGE. IN THE WAKE OF THE FRONT
AFTER DAYBREAK...SOME LINGERING STRATOCUMULUS OR MID LEVEL CLOUDS
WILL LINGER. OVERALL...VFR CONDITIONS WILL CONTINUE IN THE FRIGID
NORTHWEST FLOW THROUGH THE PM.
THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO
THE FRONTAL PASSAGE BEFORE DAYBREAK...THEN VEER TO THE W TO NW AT 6-
12 KTS WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE
WAKE OF THE ARCTIC FRONT LATE IN THE MORNING INTO THE AFTERNOON AT
12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF.
WINDS WILL SLOWLY DIMINISH DURING THE EVENING BUT WILL STILL BE
GUSTY.
THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO
MIDNIGHT...THEN VEER TO THE W TO NW AT 6-12 KTS BEFORE DAYBREAK
WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE
OF THE ARCTIC FRONT LATE TOMORROW MORNING INTO THE AFTERNOON AT
12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF.
OUTLOOK...
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN.
WASHINGTONS BIRTHDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN.
MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES
WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A
FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS
WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE.
HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO
IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE
REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF
PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE
EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL
GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT
COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF
THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON
RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY
FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF.
DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY
FOR CTZ001-013.
NY...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR NYZ032-033-038-
042-047-051-058-063-082.
WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY
FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083-
084.
MA...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY
FOR MAZ001-025.
VT...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...IRL/WASULA
NEAR TERM...11/JPV/WASULA
SHORT TERM...11
LONG TERM...ELH
AVIATION...NAS
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
635 AM EST SAT FEB 13 2016
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED
UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE
NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER
EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE
INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE
PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION
RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN
LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS
EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS
DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO
THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH
OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR
TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY.
THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC
MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE
FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED
BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG
DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL
MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY
RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL
NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF
DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE
REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON
HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT
THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY
DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH
TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S
FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S
SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY
FOR THE MAJORITY OF THE DAY.
THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR
THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE
NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES
AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR
IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE
RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER
THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE
OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE
FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR
EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL
FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW
INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE
KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S
OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4
CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH.
LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES
OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF
WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE
CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO
THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS
COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY
DROP INTO THE 20S.
HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING
SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A
SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM
THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN
TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE
MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA
EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT
COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY
LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES
AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY
SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR
ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER
FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF
MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES
TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID-
ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF
MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW
MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD
SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO
SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH
MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT
THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR
SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE
AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND
STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST
DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA.
FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN
UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES
ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE
BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE
ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE
TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER
MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND
TUE AHEAD OF THE FRONT.
&&
.AVIATION (THROUGH 12Z SUNDAY)...
A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH THE
REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT. THIS FRONT
IS CURRENTLY CROSSING THE I-4 CORRIDOR THROUGH KTPA/KPIE/KLAL...AND
WILL CONTINUE SOUTH OF KFMY/KRSW BY MIDDAY. MVFR CIGS AND PATCHY DENSE
FOG THROUGH THE I-4 TERMINALS WILL IMPROVE SHORTLY AFTER SUNRISE WITH
THE FRONTAL PASSAGE. WINDS SHIFT NORTHERLY BEHIND THE FRONT...AND THEN
NORTHEASTERLY TONIGHT. PREVAILING VFR CONDITIONS ARE FORECAST THROUGH
12Z SUNDAY FOR ALL TERMINALS AFTER THE PASSAGE OF THE FRONT THIS MORNING.
&&
.MARINE...
A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS
MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING
CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH
PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO
THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF
CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH
BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD
FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY
TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE
CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF
WEDNESDAY.
&&
.FIRE WEATHER...
A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE
WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY
VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS
THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS
COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS
EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE
DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN
AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW
LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY
FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS
AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED
THROUGH THE EARLY PORTION OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 43 68 54 / 0 0 0 0
FMY 73 47 72 55 / 0 0 0 0
GIF 69 43 66 53 / 0 0 10 10
SRQ 67 44 68 54 / 0 0 0 0
BKV 65 38 67 49 / 0 0 0 0
SPG 65 48 67 56 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
349 AM EST SAT FEB 13 2016
.DISCUSSION...
...POOR TO HAZARDOUS BOATING CONDITIONS THIS WEEKEND...
TODAY-TONIGHT...
LATEST ANALYSIS SHOWS A DRY COLD FRONT PUSHING INTO THE PANHANDLE...
A LITTLE SLOWER THAN ANTICIPATED. THE 00Z KJAX/KTAE RAOBS INDICATE
PWATS ONLY ARND 0.75"...WHILE LATEST SAT PICS SHOW A FEW CLOUD BANDS
DVLPG AHEAD OF THE FRONT IN TANDEM WITH A BAND OF H100-H85 DEWPOINT
DEPRESSIONS BTWN 3-5C OVER THE NRN PENINSULA. AHEAD OF THE FRONT...
HOWEVER...A DRY/STABLE AIRMASS REMAINS IN PLACE. THE 00Z RAOBS AT
KXMR/KTBW/KMFL MEASURED PWAT VALUES ARND 0.50"...WHILE RAP ANALYSIS
INDICATES H100-H85 DEWPOINT DEPRESSIONS BTWN 5-7C ALONG THE I-4
CORRIDOR...ARND 15C OVER LAKE OKEECHOBEE AND THE TREASURE COAST.
AS EXPECTED...THE APPROACHING FRONTAL TROF HAS ERODED THE H100-H70
RIDGE/ANTICYCLONE AXIS THAT WAS IN PLACE OVER THE FL PENINSULA ON
FRI. THE RIDGE HAS EFFECTIVELY SPLIT IN TWO WITH THE WRN HALF
RETROGRADING INTO THE WRN GOMEX...THE ERN HALF PUSHING WELL E OF THE
BAHAMA BANK TO MERGE WITH THE ATLC SUBTROPICAL RIDGE. THIS WILL
LEAVE THE FRONT WITH LITTLE IMPEDANCE TO SLOW ITS FORWARD MOTION...
ESPECIALLY GIVEN THE RAP40 INDICATES AVG H100-H70 FLOW BEHIND IT IS
NW AT 25-30KTS.
ANOTHER QUIET WX DAY IN STORE AS FRONTAL MOISTURE IS SIMPLY TOO LOW
TO SUPPORT THE FORMATION OF ANYTHING MORE THAN A LOW LVL CLOUD
DECK...MEAN RH VALUES THRU THE H100-H85 LYR ARE AOB 80PCT.
FURTHERMORE...RAOBS SHOW A LINGERING SUBSIDENCE INVERSION IN THE
H90-H80 LYR THAT WILL PANCAKE ANY CLOUD DECK BLO 5KFT.
TEMPS WILL BE A BIT ON THE COOL SIDE FROM BREVARD/OSCEOLA CO NWD
ONCE THE FRONT PUSHES THRU AS NWRLY FLOW DVLPS...KEEPING AFTN
READINGS IN THE L/M60S DESPITE NEAR FULL SUN. TREASURE COAST/LAKE
OKEECHOBEE AREAS WELL HAVE TIME TO WARM INTO THE L70S BEFORE THE
FROPA...BUT EVEN THESE WILL BE 3-5F BLO AVG. TIGHTENING PGRAD BEHIND
THE FRONT WILL ALLOW NRLY WINDS TO PERSIST OVERNIGHT...RESULTING IN
A COOL AIR ADVECTION PATTERN THAT WILL ALLOW MIN TEMPS TO FALL INTO
THE L/M40S W OF I-95. MARINE INFLUENCE WILL KEEP COASTAL TEMPS A FEW
DEGS WARMER...GENERALLY U40S/L50S.
SUNDAY...
A HIGH PRESSURE RIDGE ALONG THE EASTERN SEABOARD WILL SHIFT
OFFSHORE. AN EARLY MORNING COASTAL TROUGH WILL EXIST THEN
DISSIPATE...GIVING WAY TO AN EASTERLY WIND FLOW IN THE AFTERNOON.
THE AIR MASS WILL INITIALLY BE VERY DRY SO COASTAL RAIN CHANCES
LOOK TO BE 10-15 PERCENT. WILL LEAVE SMALL POPS ALONG THE IMMEDIATE
COAST THROUGH SUNDAY NIGHT. FORECAST SOUNDINGS ARE STILL SUPPORTIVE
OF STRATOCUMULUS SPREADING INLAND FROM THE ATLANTIC. SO DESPITE
THE MORE MILD EAST WIND FLOW...THIS CLOUDINESS SHOULD KEEP DAYTIME
HIGHS A LITTLE BELOW THOSE FROM TODAY...MAINLY MID 60S NORTH AND
UPPER 60S SOUTH. ONSHORE LOW LEVEL WINDS WILL KEEP OVERNIGHT LOWS
MORE MILD...LOWER 50S NORTH INTERIOR AND UPPER 50S SOUTH COAST.
MON INTO EARLY TUE...
THIS PERIOD IS THE MAIN ITEM OF INTEREST FOR THE UPCOMING WEEK. A
SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE SOUTHERN STATES
AND SPIN UP A SURFACE LOW. THE 00Z GFS SHOWS A WEAKER SYSTEM FARTHER
NORTH THAN 24 HOURS AGO. HENCE THE LOCAL LOW LEVEL WIND FIELDS ARE
FORECAST TO BE WEAKER. PRECIPITABLE WATER IS STILL SHOWN TO ONLY
RECOVER TO ABOUT 1.3 INCHES WITH SURFACE DEW POINTS IN THE UPPER
50S TO LOWER 60S. MOS POPS HAVE BACKED OFF TO 30-40 PERCENT FOR
MON NIGHT. THE ECMWF ALSO SHOWS A WEAKER SYSTEM BUT THE POP VALUES
ARE A LOT HIGHER THAN THE GFS.
DO NOT WANT TO MAKE SIGNIFICANT CHANGES TO THE FORECAST JUST YET
AS THE SUBTROPICAL JET CORE WILL BE NEARBY AND TEMPS ALOFT WILL
BE QUITE COLD...SO EXPECT THAT THERE COULD BE ENOUGH SUPPORT FOR
CONVECTION OVER THE GULF OF MEXICO TO SPREAD WELL INLAND. HAVE
TRIMMED POPS BACK TO 50 PERCENT FOR MON NIGHT BUT KEPT SLIGHT
CHANCE FOR THUNDER. RECENT WEAKER MODEL SOLUTIONS FOR THIS SYSTEM
SUGGEST SOME SHOWER CHANCES MAY LINGER INTO TUE.
REST OF WEEK...
COLD FRONT IS FORECAST TO PUSH EAST OF THE AREA TUE OR TUE NIGHT...
BRINGING DRYING AND WEAK COLD AIR ADVECTION. A SURFACE HIGH
PRESSURE RIDGE WILL THEN BUILD FROM THE MIDWEST TO OFF THE
ATLANTIC SEABOARD BY SAT...WITH A RIDGE AXIS SETTLING INTO THE
LOCAL AREA. TEMPS LOOK CLOSE TO NORMAL. LATE WEEK ONSHORE FLOW
SHOULD PUSH A FEW SHOWERS TOWARDS THE COAST...BUT POPS ARE TOO LOW
TO MENTION. OTHERWISE IT LOOKS DRY.
&&
.AVIATION...THRU 14/12Z
SFC WINDS: THRU 13/12Z...W/SW 4-8KTS. BTWN 13/12Z-13/15Z BCMG N/NW
8-12KTS. BTWN 13/15Z-13/23Z...N/NW 12-15KTS OCNL G18-22KTS. BTWN
13/23Z-14/02Z...BCMG N 4-7KTS.
VSBY/WX/CIGS: VFR ALL SITES.
&&
.MARINE...
TODAY-TONIGHT...POOR BOATING CONDITIONS AS A DRY COLD FRONT PUSHES
THRU THE LCL ATLC WATERS. A MODERATE TO FRESH WRLY BREEZE THRU
DAYBREAK WILL VEER TO N/NW BY MIDDAY AS THE FRONT PUSHES THRU. ROUGH
SEAS AS WINDS MAKE THE SHIFT FROM AN OFFSHORE COMPONENT TO A NRLY
COMPONENT THAT WILL BLOW OPPOSITE TO THE GULF STREAM CURRENT.
PREVAILING WAVE HEIGHTS INCREASING FROM 2-4FT TO 4-6FT NEARSHORE...
AND FROM 4-6FT TO 5-7FT OFFSHORE. STEEP WAVES WITH DOMINANT PDS BTWN
5-7SEC. CURRENT ADVISORY/CAUTION ORIENTATION LOOKS FINE FOR NOW...
BUT MAY NEED TO EXPAND THE ADVISORY TO INCLUDE NEARSHORE TREASURE
COAST WATERS BY LATE AFTN DUE TO THE GULF STREAM`S CLOSER PROXIMITY
TO THE COAST.
SUN-MON...BREEZY NORTHEAST/EAST WINDS SUN WILL VEER TO SOUTHEAST
ON MON. THIS WILL KEEP CONDITIONS POOR FOR SMALL CRAFT OPERATION.
MON NIGHT-WED...BREEZY SOUTH FLOW IS INDICATED FOR MON NIGHT. THIS
WILL TRANSPORT MOISTURE NORTHWARD AND BRING A CHANCE OF SHOWERS
AND A SLIGHT CHANCE FOR STORMS. MODELS DIFFER A BIT ON THE TUE-
WED WINDS BUT OVERALL THE TREND IS FOR A WEAKER FRONTAL PASSAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 60 45 63 54 / 0 0 20 20
MCO 68 44 67 54 / 0 0 10 10
MLB 67 50 65 58 / 0 0 20 20
VRB 69 51 68 58 / 0 0 20 20
LEE 65 41 66 52 / 0 0 10 10
SFB 65 43 66 53 / 0 0 10 10
ORL 67 44 66 53 / 0 0 10 10
FPR 69 52 68 58 / 0 0 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR SEBASTIAN INLET
TO JUPITER INLET 20-60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR FLAGLER BEACH TO
VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-BREVARD COUNTY
LINE TO SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
316 AM EST SAT FEB 13 2016
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED
UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE
NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER
EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE
INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE
PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION
RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN
LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS
EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS
DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO
THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH
OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR
TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY.
THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC
MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE
FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED
BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG
DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL
MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY
RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL
NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF
DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE
REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON
HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT
THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY
DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH
TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S
FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S
SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY
FOR THE MAJORITY OF THE DAY.
THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR
THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE
NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES
AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR
IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE
RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER
THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE
OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE
FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR
EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL
FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW
INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE
KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S
OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4
CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH.
LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES
OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF
WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE
CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO
THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS
COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY
DROP INTO THE 20S.
HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING
SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A
SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM
THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN
TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE
MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA
EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT
COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY
LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES
AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY
SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR
ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER
FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON.
&&
.LONG TERM (MONDAY THROUGH NEXT FRIDAY)...
AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF
MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES
TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID-
ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF
MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW
MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD
SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO
SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH
MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT
THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR
SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE
AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND
STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST
DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA.
FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN
UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES
ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE
BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE
ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE
TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER
MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND
TUE AHEAD OF THE FRONT.
&&
.AVIATION...
A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH
THE REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT.
THIS FRONT WILL CROSS THE TAMPA BAY AREA AROUND SUNRISE...AND THEN
PASS SOUTH OF KFMY/KRSW LATER IN THE MORNING. WINDS SHIFT
NORTHERLY BEHIND THIS FRONT...AND THE NORTHEASTERLY TONIGHT. A
BRIEF PERIOD OF MVFR CIGS IS POSSIBLE AHEAD OF THE FRONT...WITH
PATCHY FOG ALSO DEVELOPING BEFORE DAWN. A PERIOD OF IFR/MVFR VIS
IS ALSO POSSIBLE THROUGH 13Z...WITH KLAL/KPGD MOST LIKELY TO SEE
THE VIS RESTRICTIONS. PREVAILING VFR CONDITIONS ARE THEN FORECAST
THROUGH 12Z SUNDAY.
&&
.MARINE...
A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS
MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING
CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH
PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO
THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF
CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH
BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD
FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY
TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE
CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF
WEDNESDAY.
&&
.FIRE WEATHER...
A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE
WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY
VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS
THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS
COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS
EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE
DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN
AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW
LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY
FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS
AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED
THROUGH THE EARLY PORTION OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 65 43 68 54 / 0 0 0 0
FMY 73 47 72 55 / 0 0 0 0
GIF 69 43 66 53 / 0 0 10 10
SRQ 67 44 68 54 / 0 0 0 0
BKV 65 38 67 49 / 0 0 0 0
SPG 65 48 67 56 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL
CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1005 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE
COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST
AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA
MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE
REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO
RIDGE INTO THE SOUTHEASTERN STATES. CLOUDS EXPECTED TO CONTINUE
TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE
SOUTHEASTERLY OFF THE ATLANTIC...AND WEAK ISENTROPIC UPGLIDE
OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE CLOUD
COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY
OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN
SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD
AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN
THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE
SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY
LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY
PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING
THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND.
POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND
SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING
RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT
FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM
MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME
BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST
TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING
SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE
ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION
WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY
FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK
IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED
SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION
OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE.
CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE
UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT
INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM
MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO
CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS
STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE
TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED
THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN
HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY
NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER
INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE
UPPER TROUGH TAKES A NEGATIVE TILT.
NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE
AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD
OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN
PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY
MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA
EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE
QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON
TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING
AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW
MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL
SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US
BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE
END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN
CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE
AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE
NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO
60S AND LOWS IN THE 30S AND 40S.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF
THE TAF PERIOD.
MVFR CIGS ACROSS THE TAF SITES AT 03Z WITH EASTERLY WINDS 5 TO 10 KNOTS.
THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR
12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET.
HOWEVER...ALL MODELS INDICATE IFR/LIFR CONDITIONS DEVELOPING BY 16/00Z.
THE NAM MODEL CONTINUES TO INDICATE THE POSSIBILITY OF LLWS AFTER 06Z
AS A 30 TO 35 KNOT LOW LEVEL JET MOVES INTO THE AREA. NO FOG EXPECTED TO
DEVELOP TONIGHT DUE TO WIND AND CLOUDS.
MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT AS
WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT AGS/DNL/OGB
AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE DAYBREAK
MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE MORNING
HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF ANY
FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE TO
LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY
NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM
CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT
INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY UNTIL NOON EST MONDAY FOR SCZ015-016.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
658 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE
COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST
AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA
MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE
REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO
RIDGE INTO THE SOUTHEASTERN STATES. CLOUDS EXPECTED TO CONTINUE
TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE
SOUTHEASTERLY OFF THE ATLANTIC...AND WEAK ISENTROPIC UPGLIDE
OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE CLOUD
COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY
OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN
SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD
AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN
THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE
SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY
LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY
PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING
THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND.
POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND
SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING
RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT
FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM
MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME
BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST
TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING
SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE
ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION
WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY
FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK
IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED
SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION
OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE.
CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE
UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT
INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM
MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO
CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS
STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE
TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED
THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN
HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY
NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER
INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE
UPPER TROUGH TAKES A NEGATIVE TILT.
NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE
AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD
OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN
PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY
MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA
EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE
QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON
TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING
AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW
MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL
SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US
BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE
END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN
CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE
AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE
NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO
60S AND LOWS IN THE 30S AND 40S.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MVFR CIGS DEVELOPING ACROSS THE TAF SITES THIS EVENING.
MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT
AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT
AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE
DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE
MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF
ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP
DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY
IMPACTS.
CIGS LOWERING TO MVFR IN THE 02Z-06Z TIME-FRAME. THE HRRR AND GFS
MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN
LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. WINDS WILL BE
EASTERLY 10 KNOTS OR LESS. NO FOG EXPECTED TO DEVELOP TONIGHT DUE
TO WIND AND CLOUDS. THE NAM MODEL DOES INDICATE THE POSSIBILITY OF
LLWS AFTER 06Z AS A 30 TO 40 KNOT LOW LEVEL JET MOVES INTO THE
AREA.
EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY
NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM
CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT
INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015-
016.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
631 PM EST SUN FEB 14 2016
.SYNOPSIS...
A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE
COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST
AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA
MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE
REGION LATE MONDAY NIGHT AND EARLY TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO
RIDGE INTO THE SOUTHEASTERN STATES WITH DEWPOINTS IN THE SINGLE
DIGITS ACROSS THE FORECAST AREA. CLOUDS EXPECTED TO CONTINUE TO
INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE
SOUTHEASTERLY OFF THE ATLANTIC AFTER 00Z AND WEAK ISENTROPIC
UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE
CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY
OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN
SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD
AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN
THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE
SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY
LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY
PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING
THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND.
POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND
SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING
RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT
FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM
MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME
BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST
TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING
SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE
ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION
WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY
FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK
IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED
SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION
OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE.
CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE
UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT
INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM
MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO
CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS
STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE
TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED
THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN
HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY
NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER
INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE
UPPER TROUGH TAKES A NEGATIVE TILT.
NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE
AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD
OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN
PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY
MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA
EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE
QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON
TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING
AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW
MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL
SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY
NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US
BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE
END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN
CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE
AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE
NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO
60S AND LOWS IN THE 30S AND 40S.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MVFR CIGS DEVELOPING ACROSS THE TAF SITES THIS EVENING.
MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT
AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT
AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE
DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE
MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF
ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP
DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY
IMPACTS.
CIGS LOWERING TO MVFR IN THE 02Z-06Z TIME-FRAME. THE HRRR AND GFS
MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN
LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. WINDS WILL BE
EASTERLY 10 KNOTS OR LESS. NO FOG EXPECTED TO DEVELOP TONIGHT DUE
TO WIND AND CLOUDS. THE NAM MODEL DOES INDICATE THE POSSIBILITY OF
LLWS AFTER 06Z AS A 30 TO 40 KNOT LOW LEVEL JET MOVES INTO THE
AREA.
EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY
NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM
CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT
INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015-
016.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1128 PM CST FRI FEB 12 2016
.UPDATE...
ISSUED AT 859 PM CST FRI FEB 12 2016
Skies have become clear this evening and should remain that way
the rest of the night. Any additional clouds will be very late
tonight or early tomorrow morning and be cirrus clouds. Winds
remain gusty and am expecting this to continue as forecast as
well. Gusty winds will keep air mixed, but dewpoints are in the
single digits over most of the area, so still think temps by
morning will be in the single digits to just below zero in the
northwest. Only change needed is to adjust cloud cover to better
reflect current conditions. Update will be out shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 255 PM CST FRI FEB 12 2016
A weak clipper system will exit southeast of central IL late this
afternoon, with its diminishing area of very light snow/flurries
se of the IL river ending soon, with best light snow chances east
of IL over central IN. MVFR clouds already scattering nw of the IL
river like at PIA and HRRR model handling this clearing well.
These clouds to decrease se of the IL river during late
afternoon/early evening, and over southeast IL by mid evening.
Brisk NW winds of 15-25 mph and gusts to 30 mph will gradually
diminish during the night, reaching 5-15 mph later tonight. Strong
1046 mb polar high pressure west of Lake Winnipeg Canada to settle
se into MN/IA by sunrise Sat and bring a frigid night to the
region. Lows by early Saturday morning range from around zero
north of I-72 to 4-8F in southeast IL from I-70 southeast. Wind
chills by dawn will range from 5-15 below zero with a few spots
from I-74 north dipping to 15-17 below zero like at Bloomington,
Galesburg and Champaign. Will hold off on a wind chill advisory
overnight into mid Sat morning, but will issue SPS to address
these bitter cold wind chills especially in our northern CWA.
.LONG TERM...(Saturday through Friday)
ISSUED AT 255 PM CST FRI FEB 12 2016
Very cold conditions expected to start the day Saturday across
central and southeast Illinois as Arctic high pressure builds across
the area. The relatively slight pressure gradient that will
accompany the surface high should keep Wind Chill values warmer than
advisory criteria for the most part, but high temperatures should
only top out in the teens.
Beyond the initially cold conditions, our attention turns to an
approaching clipper system, which is likely to be the most
significant weather system to impact the area over the next week.
This clipper has trended faster in recent model runs, with snow now
expected to start breaking locally after midnight Saturday
night/Sunday morning. The system will be pushing into a very dry
airmass which should limit the snow accumulation to some degree.
However, fairly strong isentropic ascent and mixing ratios of 2-3
G/KG over at least a 12 hour period should be able to produce 2"=4"
snow totals. In fact, would not be surprised if we need to boost
accumulations further once the exact track of the system is more
clear (it has trended s bit south in the latest runs). One other
thing that will need to be monitored is that the moisture depth is
progged to be rather shallow during the period of potential snow.
This fact is also a reason to limit snow accumulations for now, and
we also need to monitor the threat for freezing drizzle due to a
potential lack of ice crystals.
The faster trend of the clipper system should now have Monday ending
up dry. Another weak clipper system may impact the area Tuesday into
Tuesday night, but it does not appear significant at this time.
After that, the next chance for precipitation should not occur
before the end of the week. However, model agreement in the details
of the late week system is weak at best. Temperatures should
gradually be trending warmer next week, with well above normal
temperatures likely by the end of the week (near 50 degrees for
highs). If these trends hold, the late week system, if/when it
impacts the area, should be a rain producer.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1128 PM CST FRI FEB 12 2016
VFR conditions will continue at all TAF sites next 24hrs. Clear
skies will continue overnight and through the afternoon. Models
bring in some high cirrus late tomorrow afternoon/early evening in
advance of the next weather system. The cirrus will thicken during
the evening hours, followed by some mid clouds around 12kft
reaching SPI and DEC later in the evening. Winds still a tad gusty
but not too bad so will not have any gusts in this forecast. Winds
will become lighter through the morning hours and then become
light and variable during the early evening. Later in the evening
winds will increase in speed some, but only reaching around
4-5kts. Wind direction will continue to be northwest through the
night but then switch so southeast during the evening after the
ridge goes by.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Auten
SHORT TERM...07
LONG TERM...BAK
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1241 AM EST SAT FEB 13 2016
.SYNOPSIS...
ISSUED AT 1235 AM EST SAT FEB 13 2016
THIS WEEKEND WILL FEATURE COLD TEMPERATURES WITH HIGHS INTO THE
MID TEENS TODAY AND NEAR 20 ON SUNDAY. LOWS TONIGHT WILL LIKELY
FALL TO NEAR ZERO DEGREES. LAKE EFFECT SNOW SHOWERS AND AREAS OF
BLOWING SNOW WILL CONTINUE TO IMPACT AREAS ACROSS FAR NORTHERN
INDIANA AND SOUTHWEST LOWER MICHIGAN TODAY...WITH LIGHTER
FLURRIES AND SNOW SHOWERS POSSIBLE ELSEWHERE. HIGH PRESSURE
BRIEFLY BUILDS IN FOR TONIGHT AND SUNDAY MORNING BEFORE SNOW
CHANCES RETURN LATER SUNDAY INTO EARLY MONDAY. TEMPERATURES WILL
MODERATE CLOSER TO NORMAL NEXT WEEK WITH SEVERAL CHANCES FOR LIGHT
PRECIPITATION.
&&
.UPDATE...
ISSUED AT 734 PM EST FRI FEB 12 2016
POST FNTL SHSN WITHIN EMERGING ARCTIC AIRMASS QUITE INTENSE IN
SPOTS YET THIS EVENING BUT WILL CONT TO DIMINISH AS UNSTABLE SFC
BASED LAPSE RATES DECAY W/SUNSET. REGARDLESS GROWING QUITE CONCERNED
W/UPSTREAM LAKE RESPONSE WITHIN EVOLVING/INTENSIFYING LL THERMAL
TROUGH. GENERAL CONSOLIDATION IN BANDING NOTED OVR THE LAST 3 HOURS
ALG A MUSKEGON TO ALLEGAN LINE...MIMICKING RECENT RAP MODEL
INDICATIONS AS LL FLW VEERS CONSIDERABLY W/UPSTREAM EXTENT. THIS
PRIMARY PLUME XPCD/MODELED TO INTENSIFY AS IT COMES SOUTH THROUGH
LT EVENING BFR LOCKING IN WITHIN ROUGHLY ALG A SOUTH
HAVEN...CASSOPOLIS...ELKHART...WARSAW LINE. BASED ON OBSVD RADAR
TRENDS...SUSPECT NR 1" PER HOUR PEAK SNOWFALL RATES WHICH MAY
REQUIRE SOME FORM OF HEADLINE ADJUSTMENT. WILL ATTM FOLLOW
EVOLUTION OF THIS BAND THROUGH MID EVENING AND MAKE A DECISION IF
NEEDED WELL BFR 11 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 306 PM EST FRI FEB 12 2016
CDFNT MOVG RAPIDLY E-SE ACROSS THE CWA THIS AFTN ACCOMPANIED BY A
BAND OF SNOW SHOWERS. LAKE EFFECT SNOW SHOWERS DVLPG BEHIND THE
FRONT SHOULD GRDLY INTENSIFY THIS EVE AS CAA CONTS AND WINDS VEER
FROM AROUND 300 DEGREES TO 340 DEGREES AS A SECONDARY CDFNT
CURRENTLY OVER NRN LWR MI MOVES THROUGH OUR AREA. INVERSION BASE
FORECAST TO PEAK LATE THIS EVE AROUND 6500FT WITH SIGNIFICANT LAKE
INDUCED INSTABILITY (0-2KM THETA-E LAPSE RATES OVER THE LAKE
AROUND -2.5C/KM). CONVECTION ALLOWING MODELS SUGGEST A DOMINANT
BAND OR TWO WILL SET UP AROUND THIS TIME IMPACTING NORTHWEST
PORTION OF OUR CWA. HWVR, THESE OPTIMAL CONDITIONS FOR LES SHOULD
BE SHORT LIVED AS INVERSION FCST TO LOWER/LAKE INDUCED INSTABILITY
DECREASE LATE TONIGHT AND THROUGH THE DAY SATURDAY. DGZ WILL ALSO
BE VERY LOW GIVEN ARCTIC AIRMASS MOVG IN WHICH SHOULD LIMIT ACCUMS
BLO WHAT OTRWS MIGHT BE EXPECTED. ONLY MINOR CHANGE MADE TO
PREVIOUS FCST ACCUMS WITH TOTALS TONIGHT AND SATURDAY EXPECTED TO
BE IN THE 3-6" RANGE IN THE ADVISORY AREA WITH 1-3" IN COUNTIES
SURROUNDING ADVISORY AND <1" OVER THE REST OF THE CWA. LOCALLY
HIGHER AMOUNTS PSBL IF DOMINANT BAND PERSISTS OVER ANY GIVEN AREA
VERY LONG THIS EVENING. BOUNDARY LAYER WINDS FCST 15-25KT TONIGHT
WHICH SHOULD CAUSE CONSIDERABLE BLOWING DRIFTING OF THE POWDERY
LES, MAINLY IN THE NW ADVISORY AREA. LITTLE CHANGE MADE TO TEMPS
WITH LOWS TONIGHT IN THE 0-5 RANGE NE AND SW WHERE SOME PARTIAL
CLEARING EXPECTED AND 5-10 UNDER THE LAKE EFFECT CLOUD PLUME OVER
MOST OF THE REST OF THE CWA, WITH HIGHS SATURDAY ONLY 12-16.
MINIMUM WIND CHILLS TONIGHT AND SATURDAY MORNING EXPECTED TO BE IN
THE -5 TO -15 RANGE.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI FEB 12 2016
LAKE EFFECT SNOW WILL TAPER OFF SATURDAY EVENING AS LOW LEVEL RIDGE
AXIS SHIFTS OVERHEAD AND INVERSION HEIGHTS LOWER. DGZ REMAINS ACTIVE
IN THE 00-06Z TIMEFRAME SO SOME LIGHT FLURRIES/SNOW SHOWERS EXPECTED
BUT ANY ADDITIONAL ACCUMULATION WILL BE VERY LIGHT. MAIN STORY FOR
SATURDAY NIGHT WILL BE VERY COLD TEMPS. LIGHT WINDS...PARTIALLY
CLEAR SKIES...AND FRESH SNOW WILL SUPPORT GOOD RADIATIONAL COOLING
POTENTIAL IN SPOTS. GRADIENT WIND/WAA AND CLOUDS BEGIN TO INCREASE
TOWARD 12Z BUT SHOULD STILL BE ENOUGH TIME FOR TEMPS TO DROP. KEPT
CLOSE TO INHERITED FORECAST...WHICH IS ON THE COLD SIDE OF
GUIDANCE...WITH LOWS AROUND ZERO. WILL LIKELY BE A HIGH DEGREE OF
VARIANCE IN FINAL NUMBERS THOUGH...DEPENDING ON EXACT CLOUD TRENDS.
CHANCE FOR LIGHT SNOW THEN QUICKLY RETURNS LATE SUNDAY AS NEXT
SHORTWAVE ROTATES THROUGH THE REGION. CONFLUENT FLOW OVER THE
EASTERN CONUS WILL INCREASINGLY SHEAR OUT AND WEAKEN THIS WAVE. CVA
BECOMES NEGLIGIBLE BY SUNDAY NIGHT WITH JUST SOME BROAD/WEAK 280-
285K ISENTROPIC ASCENT. DO SEE A DECENT MOISTURE SURGE THOUGH WITH
MIXING RATIOS OVER 2 G/KG. GIVEN STEADY...ALBEIT WEAK...ASCENT AND
POTENTIAL FOR HIGHER THAN CLIMO SNOW RATIOS...COULD CHURN OUT 1-2"
BY LATE MONDAY MORNING. BEST CHANCES FOR HIGHER AMOUNTS WILL BE IN
OUR SOUTHWEST WHERE BETTER MOISTURE AND FORCING RESIDE.
AFTER A BRIEF BREAK MONDAY NIGHT...THERE IS ANOTHER CHANCE FOR SNOW
TUESDAY/TUESDAY NIGHT AS POTENT NORTHERN STREAM SHORTWAVE DIVES
SOUTHEAST AND STRENGTHENS EAST COAST LOW. MODELS HAVE BEEN KEEPING
PRECIP SHIELD OF PRIMARY LOW JUST EAST OF OUR CWA BUT CONTINUE TO
STRUGGLE IMMENSELY WITH EXACT TRACK OF SECONDARY VORT MAX.
CONFIDENCE IN SNOW CHANCES REMAINS LOW AT THIS POINT WITH PARENT JET
ENERGY STILL WELL OUT OVER THE DATA-SPARSE NORTH PACIFIC. WILL
CONTINUE TO WATCH THIS PERIOD AND ADJUST AS MODELS GET A BETTER
HANDLE ON SITUATION. SOME MINOR LAKE EFFECT THEN POSSIBLE WEDNESDAY
WITH MUCH WARMER TEMPS (AND POTENTIAL FOR RAIN) STILL EXPECTED BY
THE END OF THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1235 AM EST SAT FEB 13 2016
NW FLOW LAKE EFFECT EVENT WILL CONTINUE TO PROVIDE VARIABLE
FLIGHT CONDITIONS AT KSBN THROUGH THE MORNING (VIS MAINLY IFR
WITH TIMES OF MVFR/LIFR)...WITH GRADUAL IMPROVEMENT ANTICIPATED
THIS AFTERNOON AS FLOW BACKS ALLOWING FOR DRY AIR ENTRAINMENT INTO
SHRINKING BOUNDARY LAYER. KFWA LIKELY TO GET CLIPPED BY PRIMARY
LAKE EFFECT BAND THROUGH 07Z WITH MVFR/IFR CONDITIONS ANTICIPATED.
IMPROVEMENT TO VFR/LIGHTER WINDS THEN EXPECTED FOR THE REMAINDER
OF THE NIGHT AT KFWA...WITH SCT SHSN/FLURRIES FILLING BACK IN
DURING THE DAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON
FOR INZ003>005.
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ077>079.
OH...NONE.
LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LMZ043-046.
GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ043-046.
&&
$$
UPDATE...T
SYNOPSIS...STEINWEDEL
SHORT TERM...JT
LONG TERM...AGD
AVIATION...STEINWEDEL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
405 AM CST SAT FEB 13 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CST SAT FEB 13 2016
Areal expansion of stratus will be the main forecast challenge
heading through the morning hours, and should have a significant
impact of temperature trends through the day across the far north.
Some southeastward development of freezing fog is not out of the
question this morning, however the probability for freezing drizzle
in these areas of stratus is not looking quite as probable at this
time. A large temperatures gradient is expected this afternoon in
excess of 30 degrees from the Elkhart area which should be in the
60s...to Hays where highs will not likely exceed the 30s. A
shortwave now moving into the northern Rockies will affect the
northern and central high plains region by the overnight, having
very little impact on western Kansas other than pushing a cold
front/wind shift across the region before Sunday morning.
.LONG TERM...(Sunday THROUGH Friday)
ISSUED AT 348 AM CST SAT FEB 13 2016
Models
have been consistent with a followup/secondary vort lobe rotating
through a bit farther south about 24 hours later which will
improve chances for rain or snow late Sunday night into very early
Monday morning. The remainder of the forecast period will see
rising thicknesses and more northwest flow aloft, resulting in a
warming trend through at least Thursday. Could not rule out
another 80 degree reading by Thursday as a warm dry downslope
pattern once again develops and possibly critical fire weather
conditions.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT)
ISSUED AT 1209 AM CST SAT FEB 13 2016
The HRRR model develops/spreads near IFR stratus farther south
across the area over the next few hours and maintains it through
the mid to late moring hours. Freezing fog is not a given at any
of the terminals this morning, as the HRRR indicates the best
signal on the higher terrain in northeast CO, however we will
monitor trend going foreward incase it develops farther east.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 30 56 31 / 0 0 0 10
GCK 52 29 57 30 / 10 0 0 10
EHA 65 36 58 32 / 0 0 0 10
LBL 57 32 58 30 / 0 0 0 10
HYS 36 27 51 31 / 10 0 10 20
P28 43 31 58 33 / 0 10 0 10
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1226 AM CST SAT FEB 13 2016
...UPDATED AVIATION SECTION...
.SYNOPSIS...
ISSUED AT 213 PM CST FRI FEB 12 2016
An upper level ridge of high pressure is located over the Rockies
with a long wave trough over the east coast. This places the
Central High Plains under northwest flow aloft. High to mid levels
of the atmosphere over western Kansas are fairly dry leaving only
a few high clouds visible across western Nebraska and northwest
Kansas. Some of these clouds may make it into portions of west and
west central Kansas this afternoon. As we head to the surface, low
levels of the atmosphere are saturated across portions of central
and western Kansas leading to a deck of low stratus extending
north and east of a line from Colby to Kingman. This deck of
clouds is slowly shifting southeast, however, these clouds are
expected to dissipate over the next couple of hours. An area of
low pressure with associated stationary front is sprawled out
across eastern Colorado with a dome of high pressure filtering
into the Northern Plains. This will lead to winds backing from the
northeast this afternoon to more of an easterly direction this
evening.
&&
.SHORT TERM...(THIS EVENING THROUGH Saturday)
ISSUED AT 1245 PM CST FRI FEB 12 2016
Low clouds are expected to form once again over north, west
central, and north central Kansas tonight with mostly clear skies
expected elsewhere. This deck of clouds may be thick enough for
light freezing drizzle to fall, mainly north of Highway 96. Winds
look to back form an easterly direction this evening, then
shifting southeast by midnight. Low clouds are expected to extend
into Oklahoma by sunrise tomorrow but then slowly dissipate by mid
afternoon like we saw today. Winds take more of a southerly
direction with an increase in speed tomorrow as the area of low
pressure mentioned in the synopsis intensifies and slides into
southeastern Colorado. The dome of high pressure will continue to
build across Northern and Central Plains. As for temperatures,
lows tonight look to range from the upper teens across north
central Kansas to upper 20s across far southwestern Kansas. Highs
tomorrow are anticipated to range from the mid 30s across north
central Kansas to mid 60s across far southwestern Kansas.
.LONG TERM...(Saturday NIGHT THROUGH Friday)
ISSUED AT 213 PM CST FRI FEB 12 2016
The upper level ridge in mentioned in the short term gets pushed
south Friday night into the weekend as a shortwave moves into the
Intermountain West Saturday then Northern Plains Saturday night
into Sunday. Cloudiness will increase in coverage as this system
moves into the Plains Saturday night with decreasing cloudiness on
Sunday. No precipitation is expected with this system due to lake
of moisture. This system will also help push a cold front through
the area shifting winds to more of a northerly direction. A second
shortwave is progged to move through the area Sunday night into
Monday once again increasing cloud cover across western Kansas.
There may be enough low to mid level moisture to squeeze out some
light rain or snow Sunday night but most likely we will stay dry.
An upper level ridge builds into the western Untied States early
into the mid part of next week. This will allow warmer
temperatures to build back into the area but with the sacrifice of
no measurable precipitation expected. Models then suggest another
system moving into the area late next week but that being so far
out it is hard to tell the exact track. As for temperatures, highs
in the 50s are expected Sunday, then reaching to around 60 degrees
Monday. Lows Saturday night will start out around 30 degrees, with
lower 30s Sunday night and mid 30s Monday night. A warming trend
continues through the week with highs starting out Tuesday ranging
from upper 50s north to mid 60s south ending Thursday with highs
ranging from the upper 60s north to around 80 degrees across far
southwestern Kansas. Lows during this time frame start out in the
mid 50s Tuesday night ranging from the upper 30s to mid 40s
Thursday night.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT)
ISSUED AT 1209 AM CST SAT FEB 13 2016
The HRRR model develops/spreads near IFR stratus farther south
across the area over the next few hours and maintains it through
the mid to late moring hours. Freezing fog is not a given at any
of the terminals this morning, as the HRRR indicates the best
signal on the higher terrain in northeast CO, however we will
monitor trend going foreward incase it develops farther east.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 30 56 32 / 0 0 10 20
GCK 52 30 57 31 / 10 0 10 20
EHA 64 37 58 33 / 0 0 10 10
LBL 57 32 58 32 / 0 0 10 10
HYS 36 27 52 31 / 10 0 10 20
P28 43 32 58 33 / 0 10 10 20
&&
.DDC Watches/Warnings/Advisories...NONE.
&&
$$
SYNOPSIS...Hovorka_42
SHORT TERM...Hovorka_42
LONG TERM...Hovorka_42
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 PM EST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 419 PM EST SUN FEB 14 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW DEAMPLIFYING FLOW ACROSS N
AMERICA. DEEP TROF THAT WAS OVER SE CANADA/NE CONUS 24HRS AGO IS
LIFTING NE...LEAVING BEHIND A BROAD TROF OVER THE CNTRL AND ERN
CONUS DOWNSTREAM OF A BROAD RIDGE CENTERED JUST OFF THE W COAST. A
VIGOROUS LOOKING SHORTWAVE IS TRACKING ACROSS NRN IL. ASSOCIATED
SHIELD OF SNOW HAS PASSED S OF THE AREA TODAY. UPSTREAM...SHORTWAVE
TROF OVER MANITOBA/WRN MN WILL BE THE NEXT FEATURE OF INTEREST
DURING THE SHORT TERM. MEANWHILE...INCREASING SOUTHERLY FLOW ON THE
BACKSIDE OF HIGH PRES NOW OVER THE LOWER LAKES/MID ATLANTIC STATES
IS BRINGING LES NORTHWARD OFF LAKE MI UNDER 850MB TEMPS AROUND -16C
ACROSS THE N HALF OF THE LAKE PER LATEST RAP ANALYSIS. SATELLITE AND
RADAR IMAGERY INDICATE LES HAS NOT BEEN WELL ORGANIZED AS IT LIFTED
N INTO THE SE FCST AREA THIS AFTN. THE HEAVIER SNOW HAS IMPACTED
MENOMINEE COUNTY...BUT WEB CAMS SUGGEST SNOW ACCUMULATIONS HAVE BEEN
UNDER 1 INCH.
AFOREMENTIONED SHORTWAVE TROF ACROSS WRN MN WILL SHIFT E...REACHING
CNTRL LAKE SUPERIOR/CNTRL UPPER MI AROUND 12Z MON. MODELS ARE IN
GOOD AGREEMENT SHOWING A PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND A CORRESPONDING INCREASE IN DEEPER MOISTURE AHEAD OF FEATURE.
THIS SHOULD YIELD AT LEAST SOME AREAS OF -SN MOVING ACROSS THE FCST
AREA TONIGHT. OF MORE INTEREST IS WHAT HAPPENS DOWNWIND OF LAKE MI.
WITH 850MB TEMPS OF -13/-14C ACROSS NRN LAKE MI...SYNOPTIC
FORCING/DEEPER MOSITURE WILL LEAD TO A PERIOD OF LAKE ENHANCEMENT.
IN ADDITION...AS WEAK SFC TROF ASSOCIATED WITH SHORTWAVE MOVES
ACROSS THE AREA...THE CONVERGENCE ALONG THE TROF SHARPENS UP AS IT
REACHES LAKE MI...LEADING TO A FOCUSING OF THE LAKE ENHANCED SNOW.
FCST SOUNDINGS SHOW THE DGZ ENCOMPASSING A VERY DEEP LAYER 9-10FT
THICK. WHILE MODELS DON`T SHOW MUCH UPWARD MOTION IN THAT LAYER DUE
TO THE OVERALL WEAK SYNOPTIC FORCING...IT WILL STILL HELP FLUFF UP
SNOW ACCUMULATIONS. SFC TROF STEADILY CROSSES NRN LAKE MI/SE FCST
AREA ROUGHLY DURING THE 09Z-21Z TIME FRAME. STEADY PROGRESSION WILL
LIMIT SNOW ACCUMULATIONS...BUT POTENTIAL IS THERE FOR SEVERAL INCHES
OF SNOW. FOR NOW...FCST WILL SHOW TOTAL SNOW ACCUMULATION
TONIGHT/MON OF 2-3 INCHES WITH LOCAL 4 INCH AMOUNTS FROM MENOMINEE
COUNTY INTO LUCE COUNTY...SUB ADVY AMOUNTS. HOWEVER...WILL NEED TO
MONITOR THE INCREASE IN ENHANCEMENT ALONG/JUST AHEAD OF THE SFC
TROF. SINCE MUCH OF THE SNOW ACCUMULATION WILL OCCUR WITH THIS
FEATURE AND OVER A RELATIVELY SHORT PERIOD OF TIME...THE HIGHER
SNOWFALL RATES MAY REQUIRE ISSUANCE OF AN ADVY LATER. ELSEWHERE...
SNOW ACCMULATIONS SHOULD BE UNDER 1 INCH. WITH PASSAGE OF SFC
TROF...-SN WILL END.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM EST SUN FEB 14 2016
FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS
TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY
LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE
SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS
WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE
SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS
THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z
THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN
BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT
BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW-
NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED
MORNING).
ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW
A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH
RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL
IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND
CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY
LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE
A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO
SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD
SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL
FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW
FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE
FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5
INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM
HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES
INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE
THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL
POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR
SIGNIFICANT LAKE EFFECT.
VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES
LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH
POTENTIAL FOR SOME DISTURBANCES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 646 PM EST SUN FEB 14 2016
AS A DISTURBANCE APPROACHES FROM THE WEST EXPECT CONDITIONS TO FALL
TO MVFR IN -SN AT ALL TERMINALS THIS EVENING INTO THE OVERNIGHT
HOURS. VSBY COULD OCCASIONALLY FALL TO IFR AT KSAW... WHICH WILL BE
MORE INFLUENCED BY MOISTURE ADVECTING N OFF LAKE MI. WITH A DOWNSLOPE
S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD IS LEAST LIKELY TO SEE
ANY -SN. MVFR CONDITIONS WILL PERSIST THROUGH MON.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST SUN FEB 14 2016
TIGHTENING PRES GRADIENT BETWEEN HIGH PRES NEAR THE E COAST AND A
LOW PRES TROF APPROACHING FROM THE W WILL RESULT IN SOUTHERLY WINDS
OF 20-30KT TONIGHT. THE STRONGEST WINDS WILL OCCUR OVER THE E HALF
OF THE LAKE WHERE THERE MAY BE A FEW GALE FORCE GUSTS TO 35KT. WINDS
WILL DIMINISH MON AS PRES GRADIENT WEAKENS. AFTER A PERIOD OF
RELATIVELY LIGHT WINDS UNDER 20KT MON NIGHT/TUE MORNING...PASSAGE OF
A COLD FRONT TUE WILL BRING A PERIOD OF STRONGER NORTHERLY WINDS OF
20-30KT. THERE MAY BE A PERIOD OF GALES OVER THE CNTRL PORTION OF
THE LAKE TUE NIGHT IN ADDITION TO HEAVY FREEZING SPRAY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED WITH ARRIVAL OF ANOTHER HIGH PRES
RIDGE. STRONGER SSE WIND UP TO 30 KTS WILL ARRIVE ON THU UNDER A
TIGHTENING PRES GRADIENT BETWEEN THIS HIGH SHIFTING TO THE E AND
ANOTHER APPROACHING LOW PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST SAT FEB 13 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 401 PM EST SAT FEB 13 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA
INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE
NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN
ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB
TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E...
LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE...
INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT...
BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL
SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY
SUNNY DAY OVER SCNTRL UPPER MI.
LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES
RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS
RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE
LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW
ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE...
MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE
WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E
OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE
REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF
SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS
WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING
CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE
LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES
TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER
PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN
TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST
SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO
0F.
ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE
WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC
ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH
FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A
RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH
THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN
UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF
DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND
-14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE
ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF
LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES
MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS
MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN
THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR
NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE
QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE
CONVERGENCE ZONE IS STRONG.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM EST SAT FEB 13 2016
LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN
THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO
QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER
OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET
ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT
REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE
WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE
ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT
LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK
BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE.
AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS
MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO
COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE
COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2
TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS.
MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE
MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE
WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS.
SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS
WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB
TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE
MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING
SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND
QUICK ENTRANCE OF THE RIDGE.
COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE
POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE
EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS
VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS
LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN
NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF
PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT FEB 13 2016
WITH WINDS BACKING AS HIGH PRES MOVES E...CROSSING UPPER MI
TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS AFFECTING KCMX WILL END
TONIGHT. UNTIL THEN...EXPECT IFR VIS TO PREVAIL THIS AFTN.
HOWEVER...AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE QUITE
VARIABLE AT TIMES...RANGING FROM BRIEF LIFR TO BRIEF MVFR. EXPECT
IMPROVEMENT TO MVFR AT KCMX THIS EVENING...THEN VFR OVERNIGHT. AT
KIWD...LAST OF THE STRATOCU/MVFR CIGS OFF THE LAKE SHOULD EXIT
WITHIN THE NEXT HR OR SO...LEAVING VFR CONDITIONS TO PREVAIL THRU
THE REMAINDER OF THE FCST PERIOD. AT KSAW...THERE MAY BE OCNL MVFR
CIGS THIS AFTN. OTHERWISE...VFR CONDITIONS WILL BE THE RULE THRU THE
FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EST SAT FEB 13 2016
AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL
DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH
SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO
MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING
HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE
A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE.
ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW
WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL
PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE
GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH
PRES RIDGE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR
LSZ265>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
958 PM CST SUN FEB 14 2016
.UPDATE:
Issued at 957 PM CST Sun Feb 14 2016
There may be some patchy freezing drizzle still over parts over
south central Illinois this evening. Recent radar trends have been
showing returns over this area that as it moves east, and recent
runs of the RAP are showing a drying trend at and above 925mb
after 06Z, so will carry patchy freezing drizzle until midnight.
Otherwise, have been seeing an increase in lowering visibilities
over the southern and eastern counties this evening, so went ahead
and introduced areas of fog for the rest of the the night.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 219 PM CST Sun Feb 14 2016
Most of the snow has shifted east of our forecast area this
afternoon as the shortwave was moving eastward into northwest IL.
Will keep the winter weather advisory going for parts of west
central and southwest IL until 6 pm due to patchy freezing
drizzle. The threat for patchy freezing drizzle should end later
this evening as the low level stratus cloud deck shifts east of
the area. Mid-high level cloudiness will spread back into the area
late tonight as another shortwave dives southeastward through the
Plains. Went a little colder than MOS temperature guidance for
tonight due to the new snow cover over much of the area. Rest of
the forecast still looks on track.
GKS
.LONG TERM: (Monday through Next Sunday)
Issued at 219 PM CST Sun Feb 14 2016
A shortwave and an associated surface low will pass south of our
area on Monday. Precipitation with this feature should remain
south of the forecast area, but the GFS model does generate a few
areas of light QPF over our region on Monday. Could not rule out
some patchy light rain/snow over our area on Monday. Temperatures
will be noticeably warmer on Monday, finally getting well above
the freezing mark for much of the area after a cold weekend. A
strong northwest flow shortwave and associated weak surface low will
be dropping southeastward through our area late Monday night and
Tuesday bringing another shot of rain/snow to the area. The NAM
and GFS models are similar in generating most of their QPF across
northeast MO and west central and southwest IL, but the ECMWF
model continues to have a more southwest track to the weather
system and has most of its QPF west of the Mississippi River. For
now will lean toward the NAM and GFS model solutions and put my
highest pops over northeast MO and west central and southwest IL.
Although temperatures will be fairly warm again on Tuesday there
will be the potential for a little accumulating snow late Monday
night and Tuesday morning across northeast MO and west central IL.
The models continue to depict unseasonably warm and windy
conditions for the end of the work week as an upper level ridge
moves over the region on Thursday, along with strong south-
southwesterly winds due to a tight surface pressure gradient over
our area ahead of a low pressure system moving eastward through the
northern Plains. Our next chance of measurable rain should occur
mainly Saturday night as a weak low pressure system moves
eastward through southern portions of MO and IL.
GKS
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 544 PM CST Sun Feb 14 2016
Expect mainly dry conditions through the period. VFR ceilings
currently moving in over west central Missouri will likely move
into KCOU and the St. Louis area terminals during the evening
hours. MVFR or IFR ceilings will likely persist at KUIN most of
the evening and overnight hours. Some MVFR visibilities in BR will
likely redevelop late tonight and early monday morning before VFR
conditions prevail by late Monday morning. Generally light winds
are expected.
Specifics for KSTL: Expect mainly dry conditions through the
period. MVFR ceilings are expected to lift to VFR during the
overnight hours though some MVFR BR is expected to develop late
tonight and early on Monday. VFR conditions are then expected to
prevail by mid-late morning.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
328 PM CST SAT FEB 13 2016
.DISCUSSION...
Issued at 327 PM CST SAT FEB 13 2016
Main forecast challenges deal with weather type and headlines. The
forecast area is really being split by wintry weather, both
spatially and temporally, with snowfall in our northeast and light
freezing drizzle in our south. The snowfall will likely start earlier
(late this evening) than the freezing drizzle, which may hold off
unto closer to sunrise. Strong isentropic ascent will eventually
saturate the lowest several thousand feet of the atmosphere in north
central to northeastern Missouri. Have delayed onset of snow several
hours based on forecast soundings,the large temperature/ dewpoint
depressions on surface observations and the relatively high cloud
bases. Forecast soundings for the Kirksville area saturate around
midnight or perhaps a little later. Have waited until then to
increase PoPs into the likely range. Snow amounts in our northeastern
zones are still expected to be in the 1" to as much as 3" range in
Schuyler County. After coordination with neighbors, have issued a
winter weather advisory for our extreme northeastern counties,
including the Kirksville area.
The other aspect of this wintry episode is the potential for
freezing drizzle in the southern half of the forecast area.
Confidence in this is quite a bit lower than with the snowfall in
the northeast. First, the lowest several thousand feet never really
saturate. Second, by the time saturation begins to lower, the warm
front lifts through, warms the surface above freezing and desaturates
the sounding aloft. So there really only looks like a marginal
potential for several hours when lift is maximized coincident with
the greatest amount of saturation. This seems to be around the 12Z
time frame +/- an hour or two. However, freezing drizzle can have a
major impact on travel as it can be deceptive in it`s ability to
slicken roads. So it`ll be important for people who have to travel
Sunday morning to understand that roads may be slick. But for now,
confidence just isn`t high enough to issue an advisory at this time.
Another clipper system will move through Monday night/ Tuesday
morning. Forecast soundings show the lowest several thousand feet to
be above freezing, even all the way into the northeastern portions of
the forecast area. So for snow, the wave should have little impact
with regards to wintry weather in the forecast area and we should see
just rain or perhaps a rain/snow mix in our northern zones.
The rest of the forecast looks quiet regarding precipitation. An
upper level ridge will spread east with low level flow out of the
south. This will help temperatures soar to well above normal levels
by Thursday into Friday. Highs may be in the 70s in parts of the
forecast area Thursday and potentially into Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1118 AM CST SAT FEB 13 2016
VFR conditions with ceilings between 5 and 8 thousand feet are
expected through the rest of the afternoon and into the overnight.
Late tonight, ceilings are expected to lower to MVFR and possibly
into the 1500 to 2000 ft range. There is also a chance for light
freezing drizzle across eastern Kansas and western Missouri late
tonight and early tomorrow morning. The most likely timing for this
seems to be centered around 12Z give or take a few hours.
Temperatures are expected to warm above freezing late Sunday morning
with lower levels drying out, ending the potential for freezing
drizzle.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...Winter Weather Advisory from 9 PM this evening to 6 PM CST
Sunday for MOZ008-017-025-033.
&&
$$
DISCUSSION...CDB
AVIATION...CDB
Area Forecast Discussion
National Weather Service SPRINGFIELD MO
244 PM CST SAT FEB 13 2016
...A Light Wintry Mix Late Tonight into Early on Sunday...Much
Warmer Weather Returns Next Week...
.SHORT TERM...(This Evening through Sunday)
Issued at 0217 PM CST SAT FEB 13 2016
Cold and dry air has invaded much of the Missouri Ozarks region this
afternoon. There are some areas across central Missouri that has
barely reached 20 degrees. The main story for tonight into early
tomorrow will be the threat of a light wintry mix and freezing
drizzle. The latest Hi-Res forecast models all indicate very light
precip to begin to develop between midnight and 3 am across
western and southern Missouri. The latest RUC and HRRR even shows
some convective like precip which indicates pockets of sleet possible.
The overall message for late tonight into tomorrow morning is we
are expecting only very light amounts of a light wintry mix but
could be impacts on roads and travel in the morning. Ground and
road temperatures have had time to cool down over the past 24
hours. The freezing line will settle somewhere near the Missouri
and Kansas border tonight before it begins to retreat eastward
during the morning hours. There will be very light precip falling
across the Missouri Ozarks with the better potential for higher
amounts across the eastern Ozarks. Freezing drizzle and some light
sleet is expected across the western half of the area and a wintry
mix with some light snow is expected across the eastern half of
the area early on. This will slowly transition to just a cold
light rain or drizzle late tomorrow morning into the early
afternoon from west to east.
We will issue a winter weather advisory for light amounts and
possible travel impacts in the morning. Like what we saw a few
weeks ago...it does not take much freezing drizzle to cause big
travel problems in the Ozarks region. All areas in the advisory
area can expect a very light glaze of ice possible. A dusting of
light sleet or light snow can be expected east of Highway 65 with
up to an inch of snow possible from the Highway 63 corridor and
eastward. Most area will warm up above freezing by Sunday
afternoon with some areas out across far western Missouri near 50.
.LONG TERM...(Sunday Night through Saturday)
Issued at 0217 PM CST SAT FEB 13 2016
There may be some fog developing late Sunday night into Monday
morning. This will need to be watched because temperatures again
may be around or slightly below freezing. The best potential for
fog will be along and south of the I-44 corridor across southern
Missouri.
Milder temperatures return on Monday. A quick moving upper level
system across the Midwest on Tuesday may bring a few more clouds
and a slight chance of showers across central Missouri and the
eastern Ozarks. Decent upper Level ridging will develop across
the central U.S. for the middle and end of next week. This will
allow for way above average temperatures for the region. Highs
will be in the 60s and possible lower 70s. A preview of Spring is
coming next week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1156 AM CST SAT FEB 13 2016
An upper level disturbance will slide southeast across the region
from late tonight into Sunday. This system will bring a variety of
aviation impacts.
Ceilings will lower starting late tonight with MVFR expected
during the predawn hours. We are also expecting a light wintry mix
of precipitation to develop late tonight, however precipitation
onset time remains in question due to a very dry airmass which is
currently in place. We have therefore handled this uncertainty
with TEMPO groups.
Low level wind shear conditions are also expected from late
tonight into early Sunday morning.
By sunrise, precipitation should be ongoing over most areas with
freezing drizzle being the main precipitation type. Precipitation
will begin to diminish around Joplin and then Springfield by late
morning with temperatures warming to around the freezing mark by
midday. Ceilings will remain in the MVFR category.
&&
.SGF Watches/Warnings/Advisories...
MO...Winter Weather Advisory from 3 AM to noon CST Sunday for
MOZ055>058-066>071-077>083-088>098-101>106.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
828 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 825 PM CST SUN FEB 14 2016
RADAR INDICATES SOME LIGHT TO MODERATE SNOW SHOWERS CROSSING
SOUTHWEST NEBRASKA AND SATELLITE CLOUD TEMPERATURES OF -41C
INDICATE THAT THERE IS SOME VERTICAL EXTENT...THUS WE HAVE UPDATED
TO INCLUDE A LITTLE MORE THAN SPRINKLES/FLURRIES. STILL...BECAUSE
THE SHOWERS ARE MOVING QUICKLY...ACCUMULATIONS WILL BE MINIMAL.
UPDATE ISSUED AT 747 PM CST SUN FEB 14 2016
TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE
SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN
CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR
THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS
PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL
TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM
APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON.
THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND
RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR
ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES
OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN
THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS
AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA
FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST
SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS
SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS
850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS
NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP
FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT
SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY
ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/
FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY
SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE
FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND
LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL
MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER
SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR
CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS.
MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND
MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE
DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT
WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW
LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING.
ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS
THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER
CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL
DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA
WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE
IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF
THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S.
COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE
IS RAIN.
THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE
80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF
NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB
MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER.
THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE
LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE
TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE
AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS.
THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH
H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE
UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY
CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE
OVERHEAD IN THE AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST-
SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES
RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND
ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND
INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC
LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE
FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT.
A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE
TEMPERATURE FORECAST.
A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A
PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS
AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY
AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND
GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR
THIS POTENTIAL WIND EVENT.
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD
SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES
COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60.
DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO
SUPPORT DEEP VERTICAL MIXING.
ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE
NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT
H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE
FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT.
SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE
SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE
MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE
SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE
BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE
ROCKIES DOMINATES THE COLDER ARCTIC AIR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 510 PM CST SUN FEB 14 2016
WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260-
300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING
MONDAY TO EARLY AFTERNOON.
THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT
REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF
THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS
WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR
ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF
INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE
TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS
IN THE TERMINAL FORECASTS FOR LBF OR VTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SPRINGER
SHORT TERM...SNIVELY
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
749 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 747 PM CST SUN FEB 14 2016
TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE
SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN
CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR
THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS
PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL
TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM
APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON.
THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND
RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR
ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES
OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN
THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS
AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA
FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST
SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS
SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS
850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS
NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP
FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT
SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY
ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/
FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY
SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE
FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND
LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL
MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER
SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR
CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS.
MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND
MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE
DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT
WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW
LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING.
ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS
THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER
CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL
DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA
WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE
IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF
THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S.
COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE
IS RAIN.
THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE
80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF
NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB
MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER.
THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE
LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE
TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE
AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS.
THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH
H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE
UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY
CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE
OVERHEAD IN THE AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST-
SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES
RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND
ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND
INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC
LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE
FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT.
A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE
TEMPERATURE FORECAST.
A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A
PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS
AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY
AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND
GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR
THIS POTENTIAL WIND EVENT.
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD
SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES
COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60.
DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO
SUPPORT DEEP VERTICAL MIXING.
ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE
NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT
H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE
FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT.
SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE
SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE
MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE
SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE
BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE
ROCKIES DOMINATES THE COLDER ARCTIC AIR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 510 PM CST SUN FEB 14 2016
WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260-
300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING
MONDAY TO EARLY AFTERNOON.
THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT
REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF
THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS
WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR
ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF
INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE
TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS
IN THE TERMINAL FORECASTS FOR LBF OR VTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SPRINGER
SHORT TERM...SNIVELY
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
511 PM CST SUN FEB 14 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS
PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL
TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM
APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON.
THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND
RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR
ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES
OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN
THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS
AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA
FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST
SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS
SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS
850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS
NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP
FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT
SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY
ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/
FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY
SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE
FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND
LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL
MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER
SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR
CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS.
MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND
MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE
DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT
WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW
LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING.
ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS
THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER
CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL
DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA
WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE
IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF
THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S.
COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE
IS RAIN.
THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE
80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF
NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB
MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER.
THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE
LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE
TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE
AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS.
THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH
H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE
UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY
CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE
OVERHEAD IN THE AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST-
SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES
RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND
ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND
INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC
LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE
FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT.
A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE
TEMPERATURE FORECAST.
A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A
PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS
AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY
AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND
GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR
THIS POTENTIAL WIND EVENT.
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD
SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES
COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60.
DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO
SUPPORT DEEP VERTICAL MIXING.
ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE
NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT
H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE
FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT.
SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE
SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE
MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE
SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE
BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE
ROCKIES DOMINATES THE COLDER ARCTIC AIR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 510 PM CST SUN FEB 14 2016
WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260-
300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING
MONDAY TO EARLY AFTERNOON.
THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT
REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF
THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS
WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR
ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF
INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE
TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS
IN THE TERMINAL FORECASTS FOR LBF OR VTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNIVELY
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
914 PM EST SUN FEB 14 2016
.SYNOPSIS...
BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT
SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM
SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY
EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE
AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
910 PM UPDATE..
LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT
TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER
SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY
LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH
SHOULD SLOW THE FALL OF TEMPERATURES.
I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES
FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON
CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE
VARIABILITY FROM SITE TO SITE.
4PM UPDATE...
LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS
AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE
OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM
THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE
REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL
TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION.
850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE
TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN
THE SINGLE DIGITS.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
915 PM UPDATE...
ONE MINOR UPDATE: WE ADDED FLURRIES TO THE FORECAST FOR MUCH OF
THE REGION, BEGINNING MID-MORNING. THE NAM AND GFS BOTH GENERATE
LIGHT PRECIPITATION UNDER A FAST MOVING SHORT WAVE. WE ALSO MADE
SMALL CHANGES TO THE MONDAY MORNING AND AFTERNOON QPF/SNOW FIELDS.
4 PM SUNDAY UPDATE...
A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED
TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES
TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS
BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT.
MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE
EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA-
CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO
INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST
PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND
WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL
STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER
AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH
CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND
WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN
ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL
IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION
FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN
BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT.
GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE
COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN
ISSUED.
WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN
A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE
SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE
FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO
PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE
NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE
THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS
HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR
POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO
FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS
SITUATION CLOSELY, AND WILL CONTINUE TO DO SO.
THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN
DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW
AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE
NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
442 PM UPDATE...
VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA
WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS
FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST.
AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE
REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A
POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR
TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN,
POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE
MORNING.
TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT
PASSES LATE SATURDAY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS
ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT
THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL
DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY
AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT
OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL
PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL
PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE
TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT
LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT
IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER
AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT
PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT
WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM
THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z
ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY
KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. WINDS
THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE OVERNIGHT...THEN SE
OR S 8-12 KTS MONDAY.
.OUTLOOK...
MON NGT-TUE...RESTRICTIONS IN SNOW OR WINTRY MIX MON NGT...BECOMING
MAINLY RAIN TUE.
TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO
SNOW ON BACK END OF DEPARTING STORM.
WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN.
THU-EARLY FRI...VFR.
LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH
MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY
FOR PAZ038>040-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY
FOR NYZ023>025-036-037-044>046-055>057-062.
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NYZ009-015>018-022.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...DJP/KAH
SHORT TERM...DJP/MLJ
LONG TERM...DJP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
912 PM EST SUN FEB 14 2016
.SYNOPSIS...
BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT
SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM
SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY
EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE
AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
910 PM UPDATE..
LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT
TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER
SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY
LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH
SHOULD SLOW THE FALL OF TEMPERATURES.
I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES
FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON
CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE
VARIABILITY FROM SITE TO SITE.
4PM UPDATE...
LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS
AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE
OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM
THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE
REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL
TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION.
850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE
TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN
THE SINGLE DIGITS.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
4 PM SUNDAY UPDATE...
A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED
TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES
TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS
BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT.
MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE
EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA-
CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO
INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST
PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND
WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL
STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER
AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH
CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND
WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN
ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL
IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION
FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN
BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT.
GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE
COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN
ISSUED.
WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN
A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE
SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE
FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO
PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE
NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE
THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS
HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR
POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO
FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS
SITUATION CLOSELY, AND WILL CONTINUE TO DO SO.
THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN
DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW
AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE
NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
442 PM UPDATE...
VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA
WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS
FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST.
AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE
REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A
POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR
TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN,
POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE
MORNING.
TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT
PASSES LATE SATURDAY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS
ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT
THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL
DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY
AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT
OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL
PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL
PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE
TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT
LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT
IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER
AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT
PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT
WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM
THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z
ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY
KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. WINDS
THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE OVERNIGHT...THEN SE
OR S 8-12 KTS MONDAY.
.OUTLOOK...
MON NGT-TUE...RESTRICTIONS IN SNOW OR WINTRY MIX MON NGT...BECOMING
MAINLY RAIN TUE.
TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO
SNOW ON BACK END OF DEPARTING STORM.
WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN.
THU-EARLY FRI...VFR.
LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH
MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY
FOR PAZ038>040-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY
FOR NYZ023>025-036-037-044>046-055>057-062.
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY
EVENING FOR NYZ009-015>018-022.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...DJP/KAH
SHORT TERM...MLJ
LONG TERM...DJP
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 AM EST SAT FEB 13 2016
.SYNOPSIS...ARCTIC HIGH PRESSURE WILL BUILD INTO CENTRAL NC TODAY
AND SUNDAY. AN AREA OF LOW PRESSURE WILL APPROACH FROM THE WEST ON
MONDAY AND CROSS THE REGION MONDAY NIGHT AND TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 PM FRIDAY...
STARTING TO FINALLY SEE BETTER WEST TO EAST CLEARING OF MOISTURE
AROUND 6000-7000 FT AS A JET ON THE BACK SIDE OF THE UPPER TROUGH
APPROACHES AND NORTHWEST FLOW STRENGTHENS. LOW-LEVEL MOISTURE IS
STILL MORE PREVALENT ON THE COASTAL PLAIN WHERE SOME SUB-1000 FT
STRATUS IS LINGERING. A PERIOD OF PATCHY FOG MAY DEVELOP IN THE
SOUTHERN COASTAL PLAIN AS THE HIGHER LEVEL CLOUDS CLEARING (HINTED AT
BY SREF PROBS AND KFAY/KGSB RAP SOUNDINGS)...BUT IT WOULD LIKELY BE
BRIEF...PRIOR TO 06Z...WITH A NORTHWEST WIND AND COLD ADVECTION
FORECAST TO SLOWLY STRENGTHEN AFTER MIDNIGHT. OTHERWISE...WHILE WE
MAY SEE A SOME PATCHES OF STRATOCU DRIFT ACROSS THE AREA GIVEN ALL
THE MOISTURE BANKED UPSTREAM OF THE MOUNTAINS...CLEARING SKIES AND
COLD ADVECTION WILL PUSH LOWS INTO THE LOWER 20S NORTH AND WEST TO
UPPER 20S SOUTH AND EAST.
&&
.SHORT TERM /SATURDAY AND SATURDAY NIGHT/...
AS OF 300 PM FRIDAY...
AS EAST COAST TROUGH TRIES TO PULL OFF THE COAST...VERY STRONG COLD
AIR ADVECTION WILL ENSUE BEHIND THE EXITING COASTAL SYSTEM. WITH
VERY STRONG PRESSURE GRADIENT ACROSS THE AREA...COLD TEMPERATURES
AND STRONG WINDS WILL BE THE FORECAST PROBLEM OF THE DAY. EXPECT
WINDS TO REMAIN SUSTAINED OUT OF THE NORTH OR NORTHWEST AT 10-15 KTS
WITH GUSTS OF 25-30 KTS FOR MUCH OF THE DAYLIGHT HOURS. AFTER SUNSET
GUSTS WILL SUBSIDE. HIGH TEMPERATURES ONLY IN THE LOW TO MID 30S AND
WITH WIND CHILL VALUES IN THE UPPER 10S TO LOW 20S FOR MUCH OF THE
DAY. AS AN ASIDE...WITH THE COLD BUT ALSO DRY AIRMASS IN PLACE...MIN
RH VALUES WILL DIP DOWN INTO THE LOW 20S. COMBINE THESE VALUES WITH
THE HIGHER WINDS AND THERE WILL BE A SMALL INCREASE IN FIRE DANGER
SATURDAY IN OUR SOUTHERN COUNTIES THAT MAY SQUEAK INTO THE LOWER
40S.
SATURDAY NIGHT WILL SEE THE GUSTS SLACK OFF BUT SUSTAINED WINDS TO
REMAIN UP IN THE 5 TO 10 KT RANGE KEEP THINGS MIXED A LITTLE.
COMBINE THIS WITH VERY COLD EXPECTED LOW TEMPERATURES IN THE LOW TO
MID TEENS...WIND CHILL VALUES SATURDAY NIGHT WILL RESIDE IN THE 5-10
DEGREE RANGE. PREPARATIONS SHOULD BE MADE NOW TO PROTECT ANYTHING
SUSCEPTIBLE TO THE COLD WIND CHILLS...ESPECIALLY PETS. SOME CLOUDS
WILL BEGIN TO APPROACH THE AREA LATE SATURDAY NIGHT INTO SUNDAY
MORNING FROM THE WEST IN ADVANCE OF THE NEXT STORM SYSTEM.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 315 PM FRIDAY...
...STORM SYSTEM LIKELY TO BRING WINTRY WEATHER THREAT SUN NIGHT/MON
FOLLOWED BY HEAVY RAIN THREAT AND A FEW STORMS MON NIGHT/TUE...
SUNDAY: CONTINUED CHILLY WITH THE ARCTIC HIGH PRESSURE EXTENDING
FROM THE ERN GREAT LAKES DOWN THROUGH NC. WILL HAVE INCREASING
CLOUDS AHEAD OF THE APPROACHING STORM... AS OUR MID LEVEL FLOW
SHIFTS FROM FAST NORTHWESTERLY TO WEST-SOUTHWEST... A FUNCTION OF
PACIFIC NORTHWEST ENERGY DIVING INTO AN INITIALLY FLAT/BROAD CENTRAL
CONUS TROUGH CAUSING ITS AMPLIFICATION. STATISTICAL GUIDANCE STILL
SUPPORTS HIGHS FROM 29 NE TO 35 SW. -GIH
SUN NIGHT THROUGH TUE:
OVERVIEW: CONFIDENCE IS BEGINNING TO INCREASE REGARDING THE
TIMING... MOST PROBABLE PRECIP TYPE PATTERN... AND PRIMARY WEATHER
THREATS FOR THE INCOMING SYSTEM. LATEST GUIDANCE SHOWS A BIT QUICKER
ONSET... WITH PRECIP ARRIVING IN THE NRN/WRN CWA SUN NIGHT... AS
WELL AS A SLIGHTLY EARLIER DEPARTURE ON TUE. LONGWAVE TROUGHING WILL
CONTINUE TO AMPLIFY ALONG THE MISS VALLEY AS NRN STREAM ENERGY DROPS
INTO ITS BASE OVER THE GULF STATES... CULMINATING IN A NARROW DEEP
SHORTWAVE TROUGH TAKING ON A POSITIVE TILT AS IT SWINGS ENE INTO THE
CAROLINAS. AT THE SURFACE... THE POLAR HIGH SITUATED OVER THE
NORTHEAST AND MIDATLANTIC STATES SUN NIGHT CONTINUES TO PUSH
STEADILY NORTHEAST AND OFFSHORE THROUGH MON... WHILE A COASTAL FRONT
FORMS ALONG THE CAROLINA COAST EXTENDING BACK TO DEVELOPING LOW
PRESSURE OVER THE CENTRAL GULF STATES. THIS LOW THEN TRACKS EAST
THEN NE THROUGH WRN NC MON NIGHT/TUE MORNING BEFORE MOVING QUICKLY
INTO THE NORTHEAST STATES... WITH A TRAILING FRONT SWEEPING THROUGH
CENTRAL/ERN NC BY EARLY TUE AFTERNOON.
PRECIPITATION CHANCES: THE INITIAL PROCESSES TO FORCE ASCENT SUNDAY
NIGHT INTO EARLY MONDAY INCLUDING DPVA AND MOIST ISENTROPIC UPGLIDE
ARE RATHER WEAK AND FOCUSED PRIMARILY ON WRN AND NRN PORTIONS OF
CENTRAL NC. WILL TREND POPS UP TO LIKELY NW AND RETAIN HIGH CHANCES
ACROSS THE SOUTH AND EAST SUN NIGHT INTO MON MORNING... WITH QPF
FAIRLY LIGHT... UNDER A QUARTER INCH MAINLY IN THE NW. BUT THIS
CHANGES QUICKLY WITH THE ADDITION OF STRONG UPPER DIVERGENCE (DUE TO
IDEALLY JUXTAPOSED POLAR AND SUBTROPICAL JETS) AND VIGOROUS LOW
LEVEL MOISTURE TRANSPORT EAST OF THE LOW. WILL RAMP UP POPS FURTHER
TO CATEGORICAL WEST/LIKELY EAST LATE MON... THEN TO CATEGORICAL
EVERYWHERE MON NIGHT THROUGH TUE MORNING... ENDING SW TO NE TUE
AFTERNOON.
PTYPES: USING THE TOP-DOWN METHODOLOGY WITH CONSIDERATION OF THE
INITIALLY VERY COLD/DENSE NATURE OF THE SURFACE AIR MASS... THE
INITIAL COLD AIR ALOFT GIVING WAY TO A WARM NOSE... AND THE STRONG
LOW LEVEL WARM ADVECTION APT TO DISLODGE THIS SURFACE AIR MASS
GRADUALLY FROM SE TO NW MON EVENING... EXPECT THIS TO START AS
MOSTLY LIGHT SNOW WITH PERHAPS PATCHY LIGHT SLEET SUN NIGHT ACROSS
THE NRN AND WRN CWA... FOLLOWED BY A SLOW STEADY TRANSITION FROM SSE
TO NNW TO FREEZING RAIN/SLEET THEN TO ALL RAIN... WITH THE FAR NW
COUNTIES INCLUDING THE TRIAD THE LAST TO SEE AN END TO THE WINTRY
PRECIP MON EVENING. TENTATIVE ACCUMULATIONS ARE UP TO ONE TO TWO
HUNDREDTHS OF AN INCH OF ICING (TRACE AMOUNTS) FOR MUCH OF THE
CWA... AND SNOW TOTALS OF 1-3" NW QUARTER WITH AN INCH OR LESS
ELSEWHERE... ALL OF WHICH SHOULD BE QUICKLY SWEPT AWAY BY MODERATE
TO POTENTIALLY HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING.
RAINFALL TOTALS AND STORM POTENTIAL: AT THIS TIME STORM TOTAL LIQUID
QPF IS EXPECTED TO BE 1-2" WITH LOCALLY HIGHER AMOUNTS POSSIBLE...
GIVEN THE HIGH WATER CONTENT AND STRONG LIFT MON NIGHT/TUE MORNING.
BASED ON THE ANTECEDENT CONDITIONS AND SEVERAL RIVERS AND CREEKS
RUNNING HIGH... A FLOOD WATCH MAY BE NEEDED FOR SOME PORTION OF THE
AREA. ALSO... WHILE LAPSE RATES ARE UNLIKELY TO BE VERY
IMPRESSIVE... THE STRONG AND FOCUSED LIFT POSSIBLE WITH THIS SYSTEM
AND WARMING LOW LEVELS ESPECIALLY IN THE SANDHILLS AND COASTAL PLAIN
MAY SUPPORT A FEW LIGHTNING STRIKES ON TUE.
TEMPS: EXPECT LOWS SUN NIGHT OF 22-26. TEMPS SHOULD SLOWLY RISE MON
THROUGH MON NIGHT... REACHING THE LOW 30S NW TO LOW 40S SE LATE
MON... RISING TO THE MID 30S NW TO MID 40S SE MON NIGHT... AND
PEAKING AT 48-56 TUE PRIOR TO FRONTAL PASSAGE.
WED THROUGH FRI: WE MAY SEE A PERTURBATION SWING THROUGH THE
LONGWAVE ERN TROUGH BASE ACROSS VA ON WED... BUT MODELS VARY ON THE
STRENGTH AND LATITUDE OF ANY SUCH WAVE... AND REGARDLESS THE
MOISTURE WILL BE LIMITED YIELDING NO IMPACTS ON CENTRAL NC OTHER
THAN SOME CLOUDS ACROSS THE NORTH. OTHERWISE... THIS PERIOD WILL
FEATURE A TRANSITION AWAY FROM WRN RIDGE/ERN TROUGH OVER THE
CONUS... AS FLAT RIDGING BUILDS OVER THE GULF/SOUTHEAST STATES FROM
THE WEST... WITH A NET RESULT OF DRY WEATHER AND NEAR TO SLIGHTLY
ABOVE NORMAL TEMPS FOR CENTRAL NC. -GIH
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1240 AM SATURDAY
A LAYER OF SCATTERED-BROKEN STRATOCU WILL LINGER ACROSS THE NORTHERN
COUNTIES THROUGH 10Z...THEN GRADUALLY DIMINISH. THE LEADING EDGE OF
AN ARCTIC AIRMASS WILL OVERSPREAD CENTRAL NC THROUGH 11Z. SFC WINDS
WILL GUSTS BETWEEN 20-25KTS WITH THE PASSAGE OF THE BOUNDARY.
AFTER 11Z...EXPECT VFR CONDITIONS WITH FEW-SCATTERED STRATOCU. SFC
WINDS WILL BE BRISK WITH GUSTS 22-27KTS HIGHLY PROBABLE FROM THE NW.
THESE BRISK WINDS WILL SLOWLY SUBSIDE LATER TONIGHT.
VFR CONDITIONS TO CONTINUE INTO SUNDAY THOUGH MID-HIGH LEVEL CLOUDS
WILL BE INCREASING DURING THE DAY AS AN AREA OF LOW PRESSURE APPROACHES
FROM THE WEST. MOISTURE AHEAD OF THIS SYSTEM WILL LEAD TO SUB VFR
CEILINGS ALONG WITH PATCHES OF PRECIPITATION LATE SUNDAY NIGHT INTO
MONDAY MORNING. AT ONSET...THIS PRECIPITATION MAY OCCUR AS A WINTRY
MIX. THE SUB VFR CONDITIONS MAY LINGER INTO EARLY TUESDAY WITH
IMPROVING CONDITIONS LATE TUESDAY INTO WEDNESDAY.
&&
.CLIMATE...
HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT
FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY:
REC YR REC YR
LOW LOW MAX
----------------------------------------------
GSO:
02/13 11 1955 31 1986
02/14 6 1905 22 1914
RDU:
02/13 4 1899 10 1899
02/14 -2 1899 27 1916
FAY:
02/13 14 1973 32 1955
02/14 12 1968 33 1916
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
SYNOPSIS...WSS
NEAR TERM...SMITH
SHORT TERM...ELLIS
LONG TERM...HARTFIELD
AVIATION...WSS
CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
916 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 903 PM CST SUN FEB 14 2016
NORTH DAKOTA DOT WEBCAMS SHOWING SCATTERED AREAS OF FOG FORMING AT
ASHLEY...DUNSEITH...KULM AND PETTIBONE. ALSO SEEING FOG AT
JAMESTOWN AND HARVEY AIRPORTS. ALTHOUGH THERE WILL BE SOME
VARIABILITY IN VISIBILITY AS IS TYPICAL...READY TO GO WITH AREAS
OF FOG JAMES RIVER VALLEY NORTH THROUGH RUGBY AND DUNSEITH AND
PATCHY FOG TO THE WEST INTO THE MISSOURI AND PORTIONS OF THE
SOURIS RIVER VALLEYS. WILL MONITOR FOR ANY DENSE FOG ADVISORIES
NEEDED BUT NOT AT THIS TIME.
UPDATE ISSUED AT 557 PM CST SUN FEB 14 2016
MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT
ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM
MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR
FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR
PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG
POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE
AMOUNT OF MID/HIGH CLOUDS REMAIN.
THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA.
CURRENT FORECAST TRACKING WELL SO FAR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG
POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT
RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON.
FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN
THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF
OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC.
FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK
/LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED
LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON
ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL
ONLY LOWER THROUGH THE REST OF THE DAY.
TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT
OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000
FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19
UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC
NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY
BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER
INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES
MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE
EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT
SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND
DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD.
ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE
TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN
CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON
MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND
POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE
APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG
SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON.
WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN
AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY
BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER
ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING
WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH
850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW
IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF
0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE
WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW
PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING
ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION
TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT
WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE
SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE
GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS
WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE
HWO WITH THIS FORECAST ISSUANCE.
THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY
THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH
THIS S/WV.
BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY
ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S
EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE
SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND
MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS
CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE.
UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY.
MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE
SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE
END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH
KEEPING AN EYE ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 903 PM CST SUN FEB 14 2016
FOG FORMING IN THE JAMES RIVER VALLEY. EXPECT SOME VARIABILITY BUT
WILL GO VERY LOW IFR WITH 1/2SM FZFG AT KJMS THROUGH THE NIGHT.
WILL CONTINUE TO EVALUATE TRENDS BUT BELIEVE THIS WILL BE A FOGGY
NIGHT. ELSEWHERE...EXPECT KBIS-KMOT MORE IN THE EDGE OF THE FOG
WITH 3 MILES BR. VFR KISN-KDIK UNTIL MONDAY AFTERNOON AS NEXT
SYSTEM MOVES WITH WITH MVFR CEILINGS AND CHANCE RAIN/SNOW. SINCE
THIS IS LATE IN THE FORECAST PERIOD USED VCSH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CJS
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
610 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 557 PM CST SUN FEB 14 2016
MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT
ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM
MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR
FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR
PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG
POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE
AMOUNT OF MID/HIGH CLOUDS REMAIN.
THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA.
CURRENT FORECAST TRACKING WELL SO FAR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG
POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT
RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON.
FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN
THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF
OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC.
FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK
/LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED
LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON
ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL
ONLY LOWER THROUGH THE REST OF THE DAY.
TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT
OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000
FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19
UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC
NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY
BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER
INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES
MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE
EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT
SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND
DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD.
ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE
TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN
CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON
MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND
POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE
APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG
SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON.
WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN
AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY
BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER
ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING
WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH
850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW
IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF
0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE
WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW
PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING
ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION
TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT
WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE
SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE
GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS
WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE
HWO WITH THIS FORECAST ISSUANCE.
THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY
THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH
THIS S/WV.
BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY
ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S
EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE
SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND
MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS
CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE.
UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY.
MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE
SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE
END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH
KEEPING AN EYE ON.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 557 PM CST SUN FEB 14 2016
EARLY SUNDAY EVENING A WARM FRONT EXTENDED FROM LOW PRESSURE IN
MANITOBA INTO EASTERN NORTH DAKOTA. MVFR STRATUS ASSOCIATED WITH
THE FRONT WAS PROGRESSING EAST AND IS EXPECTED TO CLEAR OUT OF
KJMS AFTER 02Z. OTHERWISE ABUNDANT SURFACE MOISTURE FROM MELTING
SNOW AND CLEARING SKIES WILL FAVOR AREAS OF FOG KBIS-KMOT-KJMS
AFTER 03Z. HRRR SHORT RANGE MODEL DEPICTS LIFR VSBYS AFTER 03Z.
CURRENTLY HAVE 3SM BR FOR THE VSBY FORECAST BUT SOME UNCERTAINTY
AS TO HOW DENSE THE FOG BECOMES. COULD BE IFR VSBYS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CJS
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1230 PM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 1215 PM CST SAT FEB 13 2016
ADDED A FREEZING RAIN ADVISORY FOR WILLIAMS AND DIVIDE COUNTY
THROUGH 00Z TONIGHT AND EXPANDED THE WINTER WEATHER ADVISORY INTO
BURKE...MOUNTRAIL...AND RENVILLE COUNTIES WITH THIS UPDATE.
LATEST OBSERVATIONS OUT OF NORTHEASTERN MONTANA AND FORECAST
SOUNDINGS NEAR WILLISTON SUPPORT A PERIOD OF FREEZING RAIN AND
SNOW MIX IN THE NORTHWEST THROUGH LATE AFTERNOON. BY
EVENING...PRECIPITATION SHOULD TRANSITION TO ALL SNOW. THE
FORECAST APPEARS ON TRACK FOR THE REST OF THE AREA.
UPDATE ISSUED AT 947 AM CST SAT FEB 13 2016
NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE
PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS
MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE
HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON
WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW
PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN
WYOMING.
UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016
EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND
TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS
UPDATE.
THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE
08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR
MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND
TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A
CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE
PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH
TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS
ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE
CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA
HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED
IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN
STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CST SAT FEB 13 2016
THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND
AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED
FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR
THE SOUTH CENTRAL.
CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO
IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES
HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS
MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE
MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5
BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR
RISING...WITH TEENS IN THE FAR WEST ALL NIGHT.
WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS
ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON
AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE
SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE
HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW
WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING.
A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS
IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE
DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO
DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL
NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE.
THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION
CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3
TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING
RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE
SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND
PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN
SOUTHWESTERN NORTH DAKOTA.
IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY
SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL -
ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST
AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN
THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT
LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE
LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER
SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL
PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW
AMOUNTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CST SAT FEB 13 2016
ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST.
THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES
ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE
BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST
PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S
ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1215 PM CST SAT FEB 13 2016
FAST MOVING LOW PRESSURE WAS DEVELOPING OVER SOUTHEASTERN
MONTANA. THIS SYSTEM WILL BRING FROZEN PRECIPITATION TO MUCH OF
THE WESTERN AND CENTRAL PARTS OF NORTH DAKOTA THROUGH THE
AFTERNOON AND OVERNIGHT HOURS. PRECIPITATION WILL BEGIN AS A MIX
OF RAIN...FREEZING...AND SNOW IN THE WEST THIS
AFTERNOON...EVENTUALLY TRANSISTIONING TO ALL SNOW BY TONIGHT. MFVR
CEILINGS AND VISIBILITES WILL BE COMMON ACROSS ALL SITES...WITH
PERIODS OF IFR/LIFR CONDITIONS POSSIBLE WITHIN ANY HEAVIER SNOW
BANDS. WINDS OF 15-20 KNOTS WILL GENERALLY COME FROM THE SOUTH
THIS AFTERNOON...TRANSITIONING WEST/NORTHWESTERLY BY THE OVERNIGHT
HOURS. PRECIPITATION WILL BEGIN TO DIMINISH EARLY SUNDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR
NDZ002>005-010>013-019>023-025-034>037-042-045>048-050-051.
FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT
FOR NDZ017-018-031>033-040-041-043-044.
FREEZING RAIN ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ001-
009.
&&
$$
UPDATE...ZH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CST SAT FEB 13 2016
.UPDATE...
ISSUED AT 947 AM CST SAT FEB 13 2016
NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE
PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS
MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE
HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON
WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW
PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN
WYOMING.
UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016
EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND
TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS
UPDATE.
THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE
08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR
MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND
TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A
CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE
PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH
TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS
ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE
CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA
HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED
IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN
STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CST SAT FEB 13 2016
THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND
AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED
FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR
THE SOUTH CENTRAL.
CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO
IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES
HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS
MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE
MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5
BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR
RISING...WITH TEENS IN THE FAR WEST ALL NIGHT.
WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS
ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON
AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE
SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE
HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW
WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING.
A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS
IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE
DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO
DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL
NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE.
THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION
CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3
TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING
RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE
SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND
PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN
SOUTHWESTERN NORTH DAKOTA.
IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY
SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL -
ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST
AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN
THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT
LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE
LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER
SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL
PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW
AMOUNTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 346 AM CST SAT FEB 13 2016
ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST.
THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES
ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE
BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST
PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S
ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 701 AM CST SAT FEB 13 2016
A BAND OF LIGHT SNOW WAS OVER NORTHWEST AND CENTRAL NORTH DAKOTA
EARLY THIS MORNING WITH CEILINGS AND VSBYS LOWERING TO MVFR. EXPECT
MVFR CEILINGS TO REMAIN AT CENTRAL ND SITES ONCE THEY ARRIVE. BUT
PERHAPS A PERIOD OF LOW VFR CEILINGS AT KISN AND KDIK 12-18Z
BEFORE LOWERING BACK TO MVFR AFT 18Z SAT. MAIN CONCERN IS LATER ON
SATURDAY 15Z- 23Z IN WESTERN ND WHEN WARM ADVECTION FROM THE WEST
WOULD BRING A WINTRY MIX STARTING WITH SNOW...LEADING TO
SLEET...THEN FREEZING RAIN...BEFORE CHANGING BACK TO SNOW AFT 00Z.
WILL BE ANALYZING LATEST MODELS AND HOPE TO HAVE A HIGHER
CONFIDENCE LEVEL FOR THE 12Z TAF ISSUANCE FOR TIMING AT KISN AND
KDIK.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR
NDZ004-005-011>013-019>023-025-034>037-042-045>048-050-051.
FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT
FOR NDZ017-018-031>033-040-041-043-044.
&&
$$
UPDATE...ZH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
853 PM EST SUN FEB 14 2016
.SYNOPSIS...
COMPLEX SYSTEM GIVES MESSY CONCOCTION OF WINTRY WEATHER THEN
WATER CONCERNS. THE SYSTEM EXITS EARLY TUESDAY...FOLLOWED BY
ANOTHER SYSTEM TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
900 PM UPDATE...EXTENDED WINTER STORM WARNINGS A ROW OR TWO
COUNTIES TO THE NORTH OF THE PREVIOUS WARNING IN THE TRISTATE AREA
DUE TO RADAR IMAGERY INDICATING A HEAVY BAND OF SNOW ORIENTED
ALONG THE I-64 CORRIDOR. ALSO...THE HI-REZ MESOSCALE MODELS LIKE
THE HRRR AND NCAR ENSEMBLES INDICATED QUITE A BIT MORE QPF THAN
THE DETERMINISTIC NATIONAL SUITE. ALSO EXTENDED ADVISORIES TO THE
NORTHERN TIER OF THE CWA...MAINLY TO HIGHLIGHT THE SNOW TONIGHT
AND POTENTIAL FOR FREEZING RAIN TOMORROW.
SNOW TO SLEET TO FREEZING RAIN OR JUST RAIN CHANGEOVER STILL LOOKS
ON TRACK FOR TOMORROW MORNING IN AND AROUND THE 6 AM TO NOON
TIMEFRAME DEPENDING ON LOCATION. SOME LOCATIONS IN THE MOUNTAINS
LIKE POCAHONTAS COUNTY COULD SEE SIGNIFICANT ICE ACCUMULATIONS OF
OVER A 1/4 TO 1/2 AN INCH...SO BE AWARE OF THAT.
PREVIOUS DISCUSSION FOLLOWS...
FLAKES SHOULD BE REACHING GROUND ON SCHEDULE IN THE TRI STATE
AROUND HTS ON SE TO SOUTHWEST VIRGINIA...NOW THROUGH DARK.
MAIN CHANGE WAS JUST TO ADD BOONE AND FAYETTE TO THE SOUTHERN
WARNING. ALSO WILL ADD JUST A FEW COUNTIES WITH THE LOWER SNOW
CRITERIA TO AN ADVISORY...INCLUDING ATHENS...WOOD...WIRT AND
CALHOUN.
AS SNOW CHANGES TO RAIN...ADDED SOME POCKETS OF FREEZING RAIN
MONDAY IN NORTH CENTRAL WEST VIRGINIA DUE TO THE COLD GROUND.
MAY EVEN BE SOME FREEZING AT 33 OR 34 DEGREES. NO REASON FOR AN
ADVISORY AT THIS DISTANCE IN TIME.
TEMPERATURES SHOULD HOLD STEADY OR SLOWLY RISE OVERNIGHT AND
MONDAY.
THE INCREASING SOUTHEAST FLOW STILL HAS US CONCERNED ABOUT THE
FREEZING RAIN FROM THE BECKLEY/OAK HILL VICINITY ON NORTHEAST TO
SNOWSHOE AND THE GREENBRIER VALLEY IN POCAHONTAS COUNTY MONDAY
AFTERNOON...THEN CONTINUING IN POCAHONTAS COUNTY MONDAY NIGHT.
SNOW AMOUNTS WERE MARGINAL FOR BOONE AND FAYETTE COUNTIES FOR THE
WARNING.
CONDITIONS IMPROVE 18Z MONDAY TO 00Z IN THE DOWNSLOPE AREAS
ESPECIALLY WILLIAMSON...LOGAN...MADISON...CHARLESTON VICINITY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
MONDAY NIGHT...MOST OF THE FORECAST AREA WILL HAVE TURNED TO ALL
RAIN HOWEVER COLD AIR BECOMES WEDGED EAST OF APPALACHIANS AND NEAR
THE SURFACE TEMPERATURES WILL LIKELY HANG AROUND TO SLIGHTLY BELOW
FREEZING THROUGH THE NIGHT IN THE MOUNTAINS. WARM LAYER ALOFT IS
MAKING FORECASTING P-TYPES MONDAY NIGHT A CHALLENGE FOR THE
MOUNTAINS. CURRENT THINKING IS STARTING THE NIGHT WITH A WINTRY
MIX AND THEN TRANSITIONING TO FREEZING RAIN. POCAHONTAS COUNTY
WILL LIKELY SEE THE BRUNT OF THE ICING WITH AMOUNTS OF OVER A
QUARTER OF AN INCH POSSIBLE.
THE OTHER CONCERN THIS FORECAST PERIOD WILL BE RAINFALL ACROSS THE
LOWLANDS MONDAY NIGHT. CURRENT QPF AMOUNTS FROM MONDAY AFTERNOON
THROUGH TUESDAY ARE CLOSE TO AN INCH IN SOME AREAS AND MINOR
FLOODING ISSUES COULD OCCUR AS RAIN FALLS ONTO FRESH SNOW FROM
EARLIER IN THE EVENT AND FROZEN GROUND. HOWEVER...TEMPERATURES
LOOK TO REMAIN IN THE UPPER 30S TO POSSIBLE LOW 40S SO NOT
EXPECTING A RAPID SNOW MELT AND THE NEW SNOW ON THE GROUND SHOULD
BE ABLE TO ABSORB A LOT OF THE WATER. AT THIS TIME WAS NOT
CONFIDENT ENOUGH IN ANY HYDRO CONCERNS TO ISSUE A FLOOD
WATCH...BUT WILL HIGHLIGHT IN THE HWO FOR NOW.
AFTER A DRIER BUT OVERCAST INTERLUDE BETWEEN SYSTEMS TUE...06Z
MODEL RUNS ARE FARTHER S WITH ANOTHER UPPER LEVEL S/W TROUGH AND
ASSOCIATED LOW PRESSURE SYSTEM PROGGED TO CROSS TUE NT. THIS WOULD
BRING COLDER AIR BACK INTO THE AREA FROM THE W THROUGHOUT THE
COLUMN OVERNIGHT TUE NT...CHANGING ANY RAIN...FREEZING RAIN OR
MIXED PRECIPITATION THAT RETURNS TUE EVENING...BACK TO SNOW...WITH
LIGHT ADDITIONAL AMOUNTS POSSIBLE OF GENERALLY 1 TO 3 INCHES.
USED MOSTLY NAM FOR TEMPERATURES ALOFT AND USED A VARIETY OF
GUIDANCE AS WELL AS PREVIOUS OFFICIAL FORECAST FOR SFC TEMPS. QPF
AMOUNTS ARE GENERALLY A MIX BETWEEN RFC AND MODEL GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
OVERALL...QUIET AND WARMER WEATHER WILL TAKE HOLD IN THE LONG TERM.
STILL SOME LIGHT UPSLOPE SNOW SHOWERS LINGERING BEHIND DEPARTING
CLIPPER EARLY THURSDAY...BUT DRIER...AND WARMER AIR WILL GRADUALLY
TAKE HOLD AS HIGH PRESSURE SURFACE AND ALOFT BUILD INTO THE REGION.
TEMPERATURES TOWARDS THE END OF THE WEEK COULD EVEN CLIMB INTO THE
50S TO LOWER 60S ACROSS THE LOWLANDS...AS WAA INCREASES OUT AHEAD OF
AN APPROACHING LOW...WHICH WILL SWEEP A COLD FRONT INTO THE REGION
OVER THE WEEKEND...WITH LIGHT RAIN SHOWERS...AND COOLER
TEMPERATURES TO END THE WEEK.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH LIGHT TO
MODERATE SNOWFALL OVERSPREADING THE AREA FROM WEST TO EAST.
LOWEST VISIBILITIES WITH IFR TO LIFR CONDITIONS WILL BE WITH HEAVIEST
SNOW...WHICH IS EXPECTED TONIGHT ACROSS EASTERN KENTUCKY EXTREME
SOUTHERN OHIO...AND THROUGH CENTRAL AND SOUTHERN WEST VIRGINIA AND
INTO SOUTHWEST VIRGINIA.
THE SNOW WILL LIKELY CHANGE TO SLEET AND THEN RAIN IN THE WESTERN
LOWLANDS FROM 12Z TO 18Z MONDAY. THERE MAY BE A PERIOD OF FREEZING
RAIN AS WELL...BUT AT THIS TIME CONFIDENCE IS TOO LOW TO PUT IT IN
THE FORECAST EXCEPT FOR BECKLEY WHERE THE FREEZING RAIN IS MOST LIKELY
TO DEVELOP DURING THAT SAME TIME FRAME.
SOME IMPROVEMENT IN CEILINGS AND VISIBILITY WILL BE POSSIBLE LATE
TOMORROW MORNING AND EARLY TOMORROW AFTERNOON...HOWEVER WARM AND
MOIST AIR MOVES IN LATER TOMORROW AFTERNOON OVER THE COLD SNOW
COVERED SURFACE AND VISIBILITIES AND CEILINGS WILL LIKELY DROP DUE
TO FOG AND RAIN.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM
ALTERNATE SCENARIOS: VISIBILITY MAY IMPROVE AGAIN 06Z TO 12Z MONDAY
ACROSS NORTHERN COUNTIES AS PRECIPITATION TEMPORARILY DECREASES
ACROSS THAT CORRIDOR WITH DRIER AIR MOVING IN. TIMING OF THE
TRANSITION FROM SNOW TO RAIN COULD BE LATER AND ALSO VISIBILITIES
MAY DROP TO IFR OR BELOW TOMORROW AFTERNOON AND EVENING WITH
ADVECTION FOG.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06
CRW CONSISTENCY L L L L L L L L L L L L
HTS CONSISTENCY L L L L L L L L L L L M
BKW CONSISTENCY L L L L L L L L L L L L
EKN CONSISTENCY H M M L L L L L L L L M
PKB CONSISTENCY M M M M M M M M L L M M
CKB CONSISTENCY H H M L L L M M M M M M
AFTER 00Z TUESDAY...
PROLONGED IFR CONDITIONS WILL LIKELY PERSIST IN MID OHIO VALLEY
AND CENTRAL APPALACHIANS INTO WEDNESDAY. LOW CEILINGS AND VSBY IN
MOSTLY RAIN AND FOG MONDAY NIGHT INTO TUESDAY...THEN MIXED LIGHT
RAIN AND SNOW TUESDAY NIGHT INTO WEDNESDAY.
&&
.EQUIPMENT...
HAVING ON/OFF PROBLEMS WITH THE CKB ASOS. TEMPERATURE READING TOO WARM AT
TIMES. TROUBLE TICKET STILL EXISTS.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR WVZ007-008-
016-027.
WINTER STORM WARNING UNTIL 1 PM EST MONDAY FOR WVZ005-006-
013>015.
WINTER STORM WARNING UNTIL 7 PM EST MONDAY FOR WVZ024>026-
033>036.
WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR WVZ009>011-
017>020-028>032-039-040.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ037-038-
047.
WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ046.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR OHZ083>087.
WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR OHZ066-067-
075-076.
KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR KYZ101.
WINTER STORM WARNING UNTIL 1 PM EST MONDAY FOR KYZ102-103-105.
VA...WINTER STORM WARNING UNTIL 7 PM EST MONDAY FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/MPK/SL
NEAR TERM...JW
SHORT TERM...MPK
LONG TERM...SL
AVIATION...MPK
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NORMAN OK
1207 PM CST SAT FEB 13 2016
.AVIATION...
GUSTY SOUTHEAST WINDS WILL PREVAIL THROUGH THE EVENING
WITH A FEW HIGH CLOUDS. MOISTURE RETURN LATE THIS EVENING
AND OVERNIGHT WILL RESULT IN AT LEAST MVFR CEILINGS...ESPECIALLY
AFTER 6Z. A LITTLE UNSURE HOW FAR LOW CEILINGS WILL EXTEND IN
WEST CENTRAL AND NORTHWEST OKLAHOMA. A FRONT WILL MOVE ACROSS
ALL TAF SITES BY 18Z SUNDAY WITH NORTH TO NORTHWEST WINDS BEHIND
THE FRONT. IFR CEILINGS MAY DEVELOP JUST AHEAD AND SHORTLY
BEHIND THE FRONTAL PASSAGE. WILL ALSO MENTION THE POTENTIAL FOR
FOG WITH BETTER CHANCES IN AND AROUND OKC/OUN.
&&
.PREV DISCUSSION... /ISSUED 1050 AM CST SAT FEB 13 2016/
DISCUSSION...
CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH
CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON.
SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST
DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT
DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH
HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A
LITTLE WARMER IN SOME AREAS.
PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/
DISCUSSION...
AVIATION...
EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE
TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM
TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER.
PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/
DISCUSSION...
SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE
AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA.
HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO
THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN
CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND
EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES
PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT
WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE
WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS
AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN
THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH
TEMPERATURES.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10
HOBART OK 55 44 63 36 / 0 0 0 0
WICHITA FALLS TX 62 48 68 40 / 0 0 0 10
GAGE OK 55 34 60 29 / 0 0 0 10
PONCA CITY OK 45 34 58 33 / 0 10 10 0
DURANT OK 56 46 62 44 / 0 10 20 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1050 AM CST SAT FEB 13 2016
.DISCUSSION...
CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH
CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON.
SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST
DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT
DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH
HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A
LITTLE WARMER IN SOME AREAS.
&&
.PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/
DISCUSSION...
AVIATION...
EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE
TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM
TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER.
PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/
DISCUSSION...
SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE
AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA.
HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO
THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN
CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND
EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES
PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT
WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE
WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS
AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN
THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH
TEMPERATURES.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10
HOBART OK 55 44 63 36 / 0 0 0 0
WICHITA FALLS TX 62 48 68 40 / 0 0 0 10
GAGE OK 55 34 60 29 / 0 0 0 10
PONCA CITY OK 45 34 58 33 / 0 10 10 0
DURANT OK 56 46 62 44 / 0 10 20 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
201 PM PST SAT FEB 13 2016
.SYNOPSIS...A STRONG WARM FRONT IS SPREADING RAIN AND BREEZY
CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS
AFTERNOON. RAIN WILL BECOME HEAVY AT TIMES...ESPECIALLY ALONG THE
COAST AND IN THE HIGHER TERRAIN. SNOW LEVELS ARE STARTING OFF NEAR
THE CASCADE PASSES...BUT ARE EXPECTED TO RISE TONIGHT AS WARMER AIR
MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA SUNDAY...THEN
LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN. HIGH PRESSURE
WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY...ESPECIALLY FOR
SOUTHERN ZONES. AN UPPER LEVEL TROUGH IS EXPECTED TO BRING COOLER AND
SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW POSSIBLE
FOR THE CASCADE PASSES AND ABOVE.
&&
.SHORT TERM...TONIGHT THROUGH TUESDAY...NWS DOPPLER RADAR SHOWS RAIN
SPREADING EASTWARD ACROSS THE FORECAST AREA THIS AFTERNOON...MAINLY
NORTH OF A LINCOLN CITY TO SALEM LINE. THIS IS ASSOCIATED WITH A
POTENT PACIFIC FRONTAL SYSTEM WHICH WILL PUSH A WARM FRONT ACROSS THE
FORECAST AREA TONIGHT. LOOKING AT THE BIGGER PICTURE...THIS FRONTAL
SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY BACK TO THE SUBTROPICAL
LATITUDES NEAR THE DATELINE. BLENDED PRECIPITABLE WATER VALUES SHOW
1.2 INCH OR HIGHER WITHIN THIS MOISTURE PLUME AS FAR EAST AS 130W.
12Z NAM/GFS SUGGEST PW VALUES AROUND 1 INCH REACHING OUR FORECAST
AREA THIS EVENING...COUPLED WITH OROGRAPHICALLY FAVORABLE W-SW WINDS
OF 40-50 KT AT 850 MB. THIS SHOULD YIELD A PERIOD OF FAIRLY HEAVY
RAINFALL FOR THE COAST AND HIGHER TERRAIN... ESPECIALLY NORTHERN
ZONES WHERE 2-4 INCHES OF RAIN ARE POSSIBLE BY SUNDAY. INLAND VALLEYS
WILL SEE LESS...RANGING FROM AROUND 0.50 INCH SOUTH OF SALEM TO
AROUND 1 INCH IN THE PDX METRO. 12Z GFS SHOWS THE BEST ISENTROPIC
LIFT MOVING THROUGH BY MIDNIGHT TONIGHT. AFTER THAT FORCING MOVES
EAST...THE WILLAMETTE VALLEY WILL LIKELY BE HEAVILY RAIN SHADOWED IN
LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY.
SNOW AMOUNTS REMAIN A CHALLENGING FORECAST FOR THE CASCADES WITH THIS
SYSTEM. OFTEN TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT
HEAT PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD
A BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE
ONE OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING
IN ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. SOME WET SNOW
IS POSSIBLE FOR THE PASSES THIS AFTERNOON INTO THIS EVENING...BUT
ACCUMULATIONS SHOULD BE LIGHT. HIGHER SKI RESORT ELEVATIONS LOOK MORE
LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000 FEET
SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED...SNOW
ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF THAT
IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER WILL
BE QUICK LATER TONIGHT OR SUNDAY MORNING. NOT EXPECTING TO CHANGE
MUCH WITH THE EXISTING WINTER WX ADVISORY FOR SNOW...THOUGH WILL
PROBABLY ADD SOME WORDING TO SUGGEST THE GREATEST ACCUMULATIONS WILL
LIKELY REMAIN UP IN THE HIGHER SKI RESORT ELEVATIONS.
THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY
FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND
CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST-
RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT
CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG
OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT...BUT SIGNIFICANT
MAIN STEM RIVER FLOODING IS NOT EXPECTED AT THIS TIME.
UPPER LEVEL RIDGING WILL BEGIN BUILDING IN FROM THE SW SUNDAY...BUT
WEAK SHORTWAVES WILL LIKELY RIDE OVER THE TOP OF THE RIDGE AND REMAIN
INTACT TO KEEP SOME RAIN IN THE PICTURE THROUGH SUN EVENING. DRYING
TREND IS EXPECTED MON/TUE AS THE UPPER RIDGE SHOVES THE MAIN
BAROCLINIC ZONE NORTHWARD INTO WA/BC. SW WA MAY REMAIN CLOSE ENOUGH
TO THE FRONTAL ZONE TO KEEP SOME RAIN OR DRIZZLE AROUND...BUT AREAS
PDX METRO SOUTHWARD SHOULD BE MAINLY DRY MON/TUE. STRENGTHENING
INVERSIONS MAY PROMOTE NIGHT AND MORNING FOG... ESPECIALLY SOUTH OF
SALEM WHERE SKIES HAVE THE BEST CHANCE OF CLEARING. ANY FOG THAT DOES
DEVELOP MAY BE STUBBORN. DID NOT FACTOR THIS INTO MON/TUE MAX TEMP
FORECASTS YET...AS THERE REMAINS A GOOD DEAL OF UNCERTAINTY AS TO IF
AND WHERE FOG WILL DEVELOP. WEAGLE
.LONG TERM...TUESDAY NIGHT THROUGH FRIDAY...THE UPPER RIDGE
RESPONSIBLE FOR THE DRYING TREND MON/TUE WILL SHIFT EAST MIDWEEK...
WITH MODELS SHOWING GOOD CONSENSUS IN BRINGING A WELL DEFINED UPPER
TROUGH INTO THE PAC NW AND POSSIBLY CALIFORNIA WED NIGHT/THU. THIS
WILL CAUSE RAIN CHANCES TO INCREASE LATER WED...WITH COOL AND SHOWERY
WEATHER LINGERING INTO THU. AIR MASS WILL START OUT RATHER WARM WITH
SNOW LEVELS WELL ABOVE THE CASCADE PASSES WED. COLDER AIR WILL MOVE
IN WITH THE UPPER TROUGH...WITH SNOW LEVELS LOWERING TO 3000 TO 3500
FEET IN SHOWERS BY THURSDAY. EXPECT TEMPS TO DROP BACK TO NEAR NORMAL
LATE WEEK AS A RESULT OF THE UPPER TROUGH...POSSIBLY EVEN A LITTLE
BELOW NORMAL. MODELS SHOW DECENT AGREEMENT THAT THIS UPPER TROUGH
WILL BE FOLLOWED BY A MORE PROGRESSIVE FRONTAL SYSTEM FOR MORE RAIN
AND CASCADE SNOW FRI/FRI NIGHT. WEAGLE
&&
.AVIATION...WARM-FRONTAL PRECIP BEGINNING TO SPREAD INTO THE S
WASHINGTON AND N OREGON COAST EARLY THIS AFTERNOON. VFR ACROSS THE
AREA...EXCEPT AREAS OF MVFR ALONG THE COAST. FLIGHT CONDITIONS
ALONG THE COAST DETERIORATE THROUGH THE AFTERNOON AND EARLY
EVENING...DROPPING TO IFR BY 00Z SUN. MVFR COVERAGE TO INCREASE
OVER THE INTERIOR LOWLANDS AFTER 00Z SUN. INTERIOR VALLEYS MAY
SEE MORE VFR OVERNIGHT THROUGH SUN DUE TO RAIN-SHADOW EFFECTS.
STRONG 850 MB WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT
OVER THE HIGHER TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND
IFR OR WORSE FLIGHT CONDITIONS.
KPDX AND APPROACHES...VFR AT 21Z. CIGS WILL CONTINUE TO LOWER
THROUGH THE AFTERNOON AND EARLY EVENING...WITH MVFR CONDITIONS
LIKELY AFTER 02Z SUN...ESPECIALLY ALONG WRN APPROACHES. S WIND
SHOULD ALLOW FOR LONGER-DURATION VFR CONDITIONS OVERNIGHT THROUGH
SUN. WEISHAAR
&&
.MARINE...WIND GUSTS ON THE EDGE OF GALE FORCE OVER THE NRN OUTER
WATERS EARLY THIS AFTERNOON. THE 14Z RUC RUN WAS A LITTLE STRONGER
COMPARED TO THE 12Z NAM. GALE FORCE WIND GUSTS OVER THE OUTER NRN
WATERS THROUGH 06Z SUN. HELD ON TO THEM A LITTLE LONGER OVER THE
NRN INNER WATERS...EXTENDING THE GALE TO 08Z. WILL ALSO NEED TO
WATCH THE NRN PART OF PZZ255 AND PZZ275 AS GUSTS COULD TOUCH GALE
FORCE TONIGHT. MODELS IN DECENT AGREEMENT SHOWING SMALL CRAFT
ADVISORY SPEEDS LATE TONIGHT THROUGH EARLY SUN AFTERNOON. 12Z NAM
BOUNDARY LAYER WIND SPEEDS A LITTLE STRONGER 18Z SUN COMPARED TO
THE GFS. WIND SPEEDS EASE A BIT MON AS THE WARM FRONT LIFTS
N...REDUCING THE SURFACE GRADIENT. BASICALLY WENT WITH THE GFS FOR
WIND MON THROUGH TUE NIGHT. MODEL DIFFERENCES BECOME GREATER WED
THROUGH THU REGARDING THE NEXT SIGNIFICANT WEATHER SYSTEM. THE
ECMWF SEEMS TO BE MORE CONSISTENT...SHOWING POSSIBLE GALES LATE
WED THROUGH EARLY THU MORNING.
A LONG PERIOD NW SWELL WILL MAINTAIN SEAS 12 TO 15 FT THROUGH
TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS WILL SUBSIDE
TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS SEAS INCREASING
TO NEAR 15 FT LATE NEXT WEEK AND POSSIBLY NEAR 20 FT NEXT WEEKEND.
WANT TO SEE A FEW MORE RUNS BEFORE GOING THAT HIGH. CAPPED SEAS TO
AROUND 15 FT FOR NOW. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR
NORTHERN OREGON CASCADES.
WA...WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR SOUTH
WASHINGTON CASCADES.
PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM CAPE
SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST SUNDAY FOR
COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM
PST SUNDAY.
GALE WARNING UNTIL MIDNIGHT PST TONIGHT FOR COASTAL WATERS FROM
CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM.
&&
$$
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 PORTLAND OR
1009 AM PST SAT FEB 13 2016
.SYNOPSIS...A STRONG WARM FRONT WILL SPREAD INCREASING RAIN AND
BREEZY CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON
THIS AFTERNOON AND TONIGHT...WITH RAIN HEAVY AT TIMES. SNOW LEVELS
WILL START NEAR THE CASCADE PASSES TODAY...BUT SHOULD RISE TONIGHT AS
WARMER AIR MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA
SUNDAY...THEN LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN.
HIGH PRESSURE WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY...
ESPECIALLY FOR SOUTHERN ZONES. AN UPPER LEVEL TROUGH WILL BRING
COOLER AND SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW
POSSIBLE FOR THE CASCADE PASSES AND ABOVE.
&&
.MORNING UPDATE...NWS DOPPLER RADAR SHOWS WARM FRONTAL RAIN STARTING
TO MOVE ONSHORE TILLAMOOK NORTHWARD...THE START OF WHAT WILL BE A
VERY WET PERIOD WHICH SHOULD LAST INTO SUNDAY. LOOKING AT THE BIGGER
PICTURE...THIS FRONTAL SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY
BACK TO THE SUBTROPICAL LATITUDES NEAR THE DATELINE. BLENDED
PRECIPITABLE WATER VALUES SHOW 1.2 INCH OR HIGHER WITHIN THIS
MOISTURE PLUME AS FAR EAST AS 135W. 12Z NAM/GFS SUGGEST PW VALUES
AROUND 1 INCH REACHING OUR FORECAST AREA THIS EVENING...COUPLED WITH
OROGRAPHICALLY-FAVORABLE W-SW WINDS OF 40-50 KT AT 850 MB. THIS
SHOULD YIELD A PERIOD OF FAIRLY HEAVY RAINFALL FOR THE COAST AND
HIGHER TERRAIN...ESPECIALLY NORTHERN ZONES WHERE 2-4 INCHES OF RAIN
ARE POSSIBLE BY SUNDAY. INLAND VALLEYS WILL SEE LESS...RANGING FROM
ABOUT 0.50 INCH NEAR EUGENE TO 0.75-1.50 INCH IN THE PDX METRO. 12Z
GFS SHOWS THE BEST ISENTROPIC LIFT MOVING THROUGH BY MIDNIGHT
TONIGHT...AFTER THAT THE WILLAMETTE VALLEY IS LIKELY TO BE HEAVILY
RAIN SHADOWED IN LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY.
SNOW AMOUNTS WILL BE TRICKY FOR THE CASCADES WITH THIS SYSTEM. OFTEN
TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT HEAT
PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD A
BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE ONE
OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING IN
ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. THERE WILL
PROBABLY BE SOME WET SNOW AT THE PASSES DURING THE ONSET OF
PRECIPITATION THIS AFTERNOON INTO THIS EVENING...BUT THIS SHOULD
CHANGE TO RAIN BY SUNDAY MORNING. HIGHER SKI RESORT ELEVATIONS LOOK
MORE LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000
FEET SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED...
SNOW ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF
THAT IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER
WILL BE QUICK LATER TONIGHT OR SUNDAY MORNING. CURRENT WINTER WX
ADVISORY FOR SNOW APPEARS TO HANDLE ALL THIS WELL AND WILL NOT BE
MAKING ANY CHANGES FOR THE MORNING PACKAGE.
THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY
FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND
CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST-
RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT
CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG
OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT. WEAGLE
/PREV DISC ISSUED 339 AM PST SAT FEB 13 2016/
.SHORT TERM...THE UPPER TROUGH ASSOCIATED WITH THE FRONTAL SYSTEM
FROM FRIDAY MOVED EASTWARD THROUGH SOUTHWEST WASHINGTON AND FAR
NORTHWEST OREGON OVERNIGHT...PRODUCING SHOWERS OVER MUCH OF THE
FORECAST AREA AND A FEW THUNDERSTORMS OVER THE NORTH COASTAL WATERS
AND THE IMMEDIATE COAST. THIS ACTIVITY WILL CONTINUE DECREASING THIS
MORNING.
ATTENTION THEN TURNS TO THE WARM FRONT APPROACHING 130W EARLY THIS
MORNING THAT WILL MOVE INTO THE FORECAST AREA THIS AFTERNOON AND
REMAIN OVER THE AREA THROUGH MUCH OF SUNDAY. THE FIRST WAVE ALONG
THIS WARM FRONT WILL SPREAD HEAVY RAIN INTO THE AREA THIS AFTERNOON
AND THROUGH AT LEAST THIS EVENING...WITH BRISK WINDS AT THE COAST
AND LOCALLY INLAND. THIS WAVE IS ACCOMPANIED BY 1.2 INCH
PRECIPITABLE WATER VALUES AND 850 MB WINDS OF NEARLY 50 KT. THIS
WAVE MOVES EAST OF THE AREA LATER SATURDAY NIGHT...BUT IS FOLLOWED
BY ONE OR TWO MORE SLIGHTLY WEAKER WAVES THAT KEEP THE RAIN GOING
THROUGH SUNDAY...THOUGH AT LESSER RAINFALL RATES.
SNOW LEVELS WILL START OUT IN THE CASCADES BETWEEN 3500 AND 4500 FEET
TODAY...AND WILL LINGER NEAR THE PASSES INTO TONIGHT. HAVE ISSUED A
SNOW ADVISORY OF THE SOUTH WASHINGTON CASCADES FROM NOON UNTIL AFTER
MIDNIGHT TONIGHT...ALSO THE NORTH OREGON CASCADES UNTIL 10 PM
TONIGHT. THE SNOW LEVEL DRAMATICALLY RISES FROM SOUTH TO NORTH
TONIGHT TO WELL ABOVE THE PASSES...TO WELL ABOVE 6000 FEET.
RAINFALL AMOUNTS OF 4 TENTHS OF TO OVER 1 INCH ARE POSSIBLE THIS
WEEKEND IN THE VALLEYS...WITH 2 TO 4 INCHES ALONG THE COAST AND IN
THE COAST RANGE AND THE CASCADES. THIS SURGE OF RAIN SHOULD CAUSE
MANY OF OUR FASTER RESPONDING RIVERS TO RISE RAPIDLY...PARTICULARLY
THE GRAYS RIVER IN WAHKIAKUM COUNTY...BUT MAIN STEM RIVER FLOODING
IS NOT ANTICIPATED. THE PERIOD WITH THE BEST CHANCE OF ANY URBAN
TYPE FLOODING WOULD BE LATER TODAY AND THIS EVENING.
THE WARM FRONT SHOULD MOVE MOSTLY NORTH OF OUR FORECAST AREA SUNDAY
NIGHT AND MONDAY WITH DECREASING RAIN. AS WE GET INTO THE WARM
SECTOR...WE COULD SEE TEMPS BACK INTO THE LOWER 60S AT LOWER
ELEVATIONS MONDAY. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MONDAY NIGHT THROUGH FRIDAY...SHORTWAVE RIDGING EARLY IN THE WEEK
WILL ONCE AGAIN GIVE WAY TO A MORE ACTIVE WEATHER PATTERN DURING THE
MIDDLE TO LATTER HALF OF NEXT WEEK. THE REMNANTS OF AN ATMOSPHERIC
RIVER EVENT MAY DIP FAR ENOUGH SOUTH TO BRING SOME LIGHT RAIN TO THE
REGION TUESDAY...BUT CONFIDENCE IS LOW. MODELS HAVE BEEN IN MUCH
BETTER AGREEMENT THAT A SHORTWAVE TROUGH WILL SWING INTO THE WESTERN
UNITED STATES AND BRING WET AND COOLER WEATHER WEDNESDAY INTO
THURSDAY. AN ADDITIONAL STORM SYSTEM APPEARS POSSIBLE TOWARDS THE END
OF NEXT WEEK. TEMPERATURES FOR THE MOST PART SHOULD REMAIN NEAR TO
ABOVE NORMAL WITH ANY BOUTS OF PRECIPITATION LOOKING TO REMAIN LIGHT
ENOUGH THAT WE DO NOT FORESEE ANY MAJOR HYDROLOGIC ISSUES IN THE NEXT
WEEK. AB/NEUMAN
&&
.AVIATION...GENERALLY VFR AT 16Z...EXCEPT FOR AREAS OF MVFR ALONG
THE S WASHINGTON AND FAR N OREGON COAST. THE NEXT WARM FRONT WILL
IMPACT THE AREA LATE THIS AFTERNOON THROUGH SUNDAY. EXPECT
CONDITIONS TO DETERIORATE WITH INCREASING RAIN FROM NW TO SE MID
TO LATE AFTERNOON THROUGH TONIGHT...WITH IFR LIKELY ALONG THE
COAST. INTERIOR VALLEYS MAY ACTUALLY REMAIN VFR THIS AFTERNOON
THROUGH TONIGHT DUE TO SOME RAIN-SHADOW EFFECTS. STRONG 850 MB
WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT OVER THE HIGHER
TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND IFR OR WORSE
FLIGHT CONDITIONS.
KPDX AND APPROACHES...VFR PREVAILING TODAY...EXCEPT FOR POSSIBLE
MVFR CIGS MID TO LATE-AFTERNOON THROUGH EARLY EVENING AS PRECIP
INCREASES. S WIND SHOULD ALLOW FOR PRIMARILY VFR CONDITIONS LATER
THIS EVENING THROUGH SUN MORNING.
&&
.MARINE...WIND WILL INCREASE TODAY AS A WARM FRONT MOVES THROUGH
THE WATERS. 14Z RUC RUN A LITTLE STRONGER COMPARED TO THE LATEST
NAM. EXPECT SMALL CRAFT ADVISORY WIND SPEEDS TO RAMP UP TO GALE
FORCE WIND GUSTS LATE THIS EVENING OVER THE N OUTER WATERS. GALES
TO SPREAD INTO THE N INNER WATERS OVERNIGHT. GALES COULD LAST A
LITTLE LONGER THAN CURRENT FORECAST IMPLIES...BUT WILL LOOK AT
THAT MORE FOR THE AFTERNOON. RAMPED UP WIND SPEEDS A BIT SUN...WITH
SOLID SMALL CRAFT ADVISORY SPEEDS EXPECTED.
A LONG PERIOD NW SWELL WILL MAINTAIN 11 TO 13 FT SEAS TODAY THEN
12 TO 15 FT TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS
WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS
SEAS INCREASING TO NEAR 15 FT LATE NEXT WEEK.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM
PST THIS EVENING FOR NORTHERN OREGON CASCADES.
WA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 4 AM PST SUNDAY
FOR SOUTH WASHINGTON CASCADES.
PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM
CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO
6 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO
FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY
FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
PST SUNDAY.
GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 PM PST THIS EVENING
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD
OR OUT 10 NM.
&&
$$
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
1230 PM EST SAT FEB 13 2016
.SYNOPSIS...
POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE
WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL
SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS
EASTERN PA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED GRIDS FOR TEMPS/WINDS AND SNOW SHOWERS FOR QUICK LOOK AND
ACCIDENT ON I78 IN LEBANON COUNTY WHICH HAS EM PERSONNEL WORKING
ON SITE OF ACCIDENT.
PREVIOUS:
ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY.
TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES.
STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE
NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL
PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF
THE REGION TODAY INTO SUNDAY.
WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER
UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO.
RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE
BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS
BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT
SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING.
MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER
AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM
TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN
THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A
PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS
KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND
IN NORTHWESTERN PA THIS EVENING.
COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING
SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF
SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE
FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND
MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME
AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL
COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS.
THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED
OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND
THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD
VALENTINES AT LEAST OUTDOORS.
THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING
CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO
MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW
SUNDAY LIKELY WILL BE EARLY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
WEEK.
BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO
THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH
IMPACTS ON KJST AND KBFD. SOME OF THE STRONGER LAKE STREAMERS AND
SNOW SHOWERS HAVE MADE TO THE MARYLAND BORDER IN SOUTHEASTERN PA.
SO SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS.
GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER
30KTS HAVE BEEN OBSERVED.
IFR AND MVFR MOST OF WEST. VFR WITH TIME MVFR IN CENTRAL AREAS.
MOSTLY VFR WITH TIMES MVFR WITH SNOW/BLOWING SNOW IN SOME PARTS OF
SOUTHEAST TODAY.
THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AND
OVERNIGHT. THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD.
NEED A HEATED JOY STICK.
HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE
WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL
PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND
ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY
INTO TUESDAY.
OUTLOOK...
SUN...NO SIG WX EXPECTED MAINLY VFR.
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN
AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS
SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017-
018-024-033.
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028-
034>036-045-046-049>053-056>059-063>066.
WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059-
063>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1013 AM EST SAT FEB 13 2016
.SYNOPSIS...
POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE
WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL
SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS
EASTERN PA ON TUESDAY.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY.
TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES.
STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE
NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL
PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF
THE REGION TODAY INTO SUNDAY.
WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER
UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO.
RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE
BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS
BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT
SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING.
MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER
AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM
TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN
THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A
PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS
KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND
IN NORTHWESTERN PA THIS EVENING.
COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING
SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 7 PM SUNDAY/...
MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF
SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE
FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND
MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME
AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL
COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS.
THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED
OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND
THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD
VALENTINES AT LEAST OUTDOORS.
THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING
CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO
MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW
SUNDAY LIKELY WILL BE EARLY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
*IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT
WEEK.
BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT
SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER
SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE
BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND
ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD
CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS
EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS
EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL
UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST
FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE
LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS.
WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS
EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL
ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A
POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS
HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY.
NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS
HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS
THROUGH THE GREAT LAKES TO THE WEST OF PA.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
ARCTIC AIR MASS POURING INTO THE REGION EARLY THIS MORNING...
CURRENTLY ACCOMPANIED BY GUSTY NW WINDS OF 15G25KTS. WINDS WILL
PICK UP FURTHER DURING THE DAY...WITH GUSTS APPROACHING
40-45KTS...BEFORE GRADUALLY DIMINISHING TONIGHT.
RADAR AT 11Z SHOWING SCT SHSN ACCOMPANYING ARRIVAL OF ARCTIC AIR
MASS ACROSS WESTERN/CENTRAL MTNS. ARRIVAL OF LOW PWAT AIR MASS
SHOULD CAUSE MOST OF THESE SNOW SHOWERS TO DISSIPATE EARLY IN THE
DAY. SNOW SHOWERS WILL LINGER OVER WARREN COUNTY /WITH POSSIBLE
BRIEF EXCURSIONS TOWARD KBFD/ WITH MORE PERSISTENT SNOW
SHOWERS/BANDS ASSOC WITH LK HURON CONNECTION TO LAST THRU THE DAY
ACROSS THE LAUREL HIGHLANDS /KJST/. RESTRICTIONS WILL PERSIST OVER
WESTERN HIGHER TERRAIN. BUT WITH DOWNSLOPE FLOW KICKING IN FOR
CENTRAL MTNS AND SE...VFR WILL BE THE GENERAL RULE - WITH JUST A
CHANCE FOR SOME SCT SNOW BANDS TO CREEP INTO PORTIONS OF THE
CENTRAL MTNS LATE DAY.
OUTLOOK...
SUN...NO SIG WX EXPECTED.
MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING.
MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN AND/OR
SNOW IN THE SE. WIDESPREAD RESTRICTIONS CONTINUE. LLWS POSS SE.
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN
PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037-
041-042.
WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017-
018-024-033.
WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028-
034>036-045-046-049>053-056>059-063>066.
WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST
SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059-
063>066.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024-
033.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...GRUMM
SHORT TERM...GRUMM/FITZGERALD
LONG TERM...FITZGERALD/GARTNER
AVIATION...RXR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
158 PM MST SAT FEB 13 2016
.UPDATE...
ISSUED AT 158 PM MST SAT FEB 13 2016
STRONG WINDS NOTED ALONG COLD FRONT MOVING INTO NORTHEAST
WY...GUSTING OVER 60 MPH FOR A BRIEF PERIOD IN SOME AREAS. BOTH
HRRR AND RUC SHOW THESE STRONG WINDS MOVING ACROSS NORTHEAST WY
DURING THE AFTERNOON AND INTO THE BLACK HILLS AREA LATE THIS
AFTERNOON/EARLY EVENING AS THE FRONT CROSSES. SHOWERS ACCOMPANYING
THE FRONT WILL ALSO HELP TO MIX STRONGER WINDS ALOFT DOWN. HAVE
DECIDED TO ISSUE A HIGH WIND WARNING FOR NORTHEAST WY AND MUCH OF
THE BLACK HILLS AREA. WINDS SHOULD DIMINISH WITH THE FRONT AS IT
MOVES EAST OF THE BLACK HILLS AND INTO COOLER AND MORE STABLE AIR
TO THE EAST.
UPDATE ISSUED AT 1238 AM MST SAT FEB 13 2016
CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR SOUTHWEST SK...
WITH WARM FRONT EXTENDING SOUTHEAST INTO THE BLACK HILLS AREA AND
SOUTHWEST SD. COLD FRONT EXTENDS SOUTHWARD ACROSS CENTRAL MT INTO
NORTHWEST WY. UPPER LEVEL ANALYSIS SHOWS STRONG SHORTWAVE MOVING
EAST- SOUTHEAST ACROSS CENTRAL MT...WITH STRONG JET WRAPPING
AROUND IT FROM THE NORTHERN ROCKIES THROUGH SD. LATEST OBS SHOW
TEMPS RANGING FROM THE UPPER TEENS IN THE LEMMON AREA TO THE 50S
OVER CAMPBELL CO WY. THE FREEZING LINE RIGHT NOW EXTENDS FROM NEAR
BELLE FOURCHE TO NORTH OF PHILIP AND THEN SOUTH- SOUTHEAST TO
MELLETTE AND TODD COUNTIES IN SOUTH CENTRAL SD. KUDX RADAR SHOWING
SOME PCPN FROM MEADE CO INTO HAAKON AND ZIEBACH COUNTIES...MOSTLY
IN THE FORM OF RAIN...WITH SOME FREEZING RAIN OR SNOW LIKELY OVER
NORTHEAST MEADE INTO ZIEBACH CO. REGIONAL RADARS SHOW MORE
ACTIVITY DEVELOP TO THE WEST OVER SOUTH CENTRAL MT AND NORTH
CENTRAL WY NEAR THE SHORTWAVE AND COLD FRONT. SOME STRONG WINDS
HAVE ALSO BEEN NOTED NEAR THE FRONT AND WITH SHOWER ACTIVITY
THERE...AS TEMPS HAVE RISEN INTO THE 50S AND LOWER 60S. THESE
SHOWERS AND WIND WILL MOVE INTO NORTHEAST WY EARLY THIS AFTERNOON
AND REACH THE BLACK HILLS AREA LATE IN THE AFTERNOON. A SPECIAL
WEATHER STATEMENT HAS BEEN ISSUED FOR THE STRONG WIND GUSTS
EXPECTED WITH SHOWERS THIS AFTERNOON.
UPDATE HAS BEEN SENT TO ADJUST PCPN TYPE THIS AFTERNOON BASED ON
CURRENT TEMPS AND EXPECTED TRENDS. THE MAIN THREAT FOR FREEZING
RAIN AND A LITTLE SNOW WILL BE FROM PERKINS INTO ZIEBACH COUNTIES
THROUGH THE AFTERNOON. ICE ACCUMULATION UP TO A TENTH OF AN INCH
IS STILL EXPECTED. HARDING COUNTY WILL SEE TEMPS RISE TO ABOVE
FREEZING BY LATE AFTERNOON AS THE WARM FRONT MOVES THROUGH...
EVENTUALLY SWITCHING PCPN TO ALL RAIN. SOME ADJUSTMENTS WERE ALSO
MADE TO CLOUD COVER...WINDS...AND HIGH TEMPS.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 327 AM MST SAT FEB 13 2016
UPPER TROUGH CONTINUES ACROSS THE ERN HALF OF THE CONUS WITH NW FLOW
OVER THE NRN PLAINS. A STRONG FAST MOVING SHORTWAVE IS CROSSING THE
CASCADES INTO THE NRN ROCKIES ATTM. CANADIAN HIGH PRES IS SITTING
ACROSS THE UPPER MIDWEST WITH A STRONG BAROCLINIC ZONE OVER THE
CNTRL TO ERN DAKOTAS. WARM AIR ADVECTION HAS BEGUN OVER THE CWA AS
THE FRONTAL BOUNDARY SLIDES E/NE. TEMPS AT 800MB HAVE RISEN ABOVE
FREEZING ACROSS MOST OF THE CWA...AND WILL DO SO INTO CNTRL SD OVER
THE NEXT 3 TO 6 HOURS. TEMPS WILL WARM ABOVE FREEZING TODAY ACROSS
NE WY TO MUCH OF WRN SD...HOWEVER FREEZING TEMPS ARE PROGGED ACROSS
PTNS OF NW/NCNTRL SD THROUGH MUCH OF TODAY. AS THE SHORTWAVE PUSHES
THROUGH THE REGION TODAY...PRECIP WILL DEVELOP ESPECIALLY ACROSS THE
NRN HALF OF THE AREA. WARM LOW LEVELS SHOW THIS WILL FALL AS RAIN.
CONCERN IS LINGERING SUB-FREEZING TEMPS ACROSS THE NRN PARTS OF
THE CWA WILL RESULT IN A PERIOD OF FREEZING RAIN ESPECIALLY
THROUGH THE AFTERNOON. WILL KEEP WINTER WEATHER ADVISORY ISSUED
YESTERDAY BUT HAVE EXPANDED IT ACROSS HARDING COUNTY WITH THE
SREF/HRRR SHOWING PRECIP POTENTIALLY BEGINNING LATE THIS MORNING
WHEN SURFACE TEMPS ARE STILL BELOW FREEZING. BEHIND THE SHORTWAVE
...SUB-FREEZING LOW LEVELS WILL QUICKLY PUSH BACK INTO THE REGION
ENDING THE THREAT FOR FREEZING RAIN AS IT BECOMES ALL SNOW IN THE
AFTERNOON/EVENING. PARTS OF NW/CNTRL SD COULD SEE 1 TO 3 INCHES
OF ACCUMULATION BEFORE PRECIP ENDS DURING THE OVERNIGHT HOURS.
WITH LOW LEVEL INSTABILITY THAT DEVELOPS...MAY EVEN A FEW
LIGHTNING STRIKES. MODELS SHOWING 700-850MB WINDS REACHING 50KT
BRIEFLY NEAR THE FRONTAL BOUNDARY WHICH WOULD CREATE A SHORT
PERIOD OF STRONG WINDS FOR NOT MORE THAN AN HOUR OR SO.
W/NW WINDS WILL CONTINUE ACROSS THE AREA SUNDAY AS LOW PRESSURE SITS
EAST OF THE AREA. WARMER TEMPS NEAR THE SURFACE WILL ALLOW HIGHS TO
REACH THE UPPER 30S TO UPPER 40S...HOWEVER COOLER 700MB TEMPS WILL
RESULT IN INSTABILITY IN THE LOW LEVELS WHICH WILL ALLOW FOR
UPSLOPING TO DEVELOP ACROSS THE NRN/WRN BLKHLS. PRECIP WILL BE RAIN
EXCEPT SOME SNOW AT THE HIGHEST ELEVATIONS. THIS LIGHT PRECIP WILL
LINGER INTO SUNDAY NIGHT.
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 327 AM MST SAT FEB 13 2016
EASTERN NOAM TROUGH WILL BREAKDOWN IN THE PERIOD...ALLOWING MEAN
RIDGING TO SPREAD EAST INTO CENTRAL NOAM. THIS WILL RESULT IN A
TREND TO VERY MILD/DRY CONDS BY MID WEEK AS STAUNCH WAA SPREADS
INTO THE NORTHERN PLAINS. BEFORE THIS OCCURS...ANOTHER NW FLOW
IMPULSE WILL ADVECT ACROSS THE NORTHERN PLAINS...SUPPORTING RA/SN
SHOWERS MON INTO TUE. VERY WARM WEATHER CAN BE EXPECTED BY WED AND
ESP THUR. HIGHS ACROSS THE FA THUR LOOK TO APPROACH AND PASS 70 AT
SOME LOCATIONS...ESP IN THE LEE OF THE BH WHERE DOWNSLOPING WILL
BE IN PLACE AHEAD OF A DEEP SFC CYCLONE THAT WILL ADVECT EAST
THROUGH THE REGION SPURRED BY AMPLIFIED ACTIVE FLOW OVER THE
EASTERN PAC. THUR-FRI LOW PRESSURE SYSTEM MAY ALSO SUPPORT ANOTHER
HIGH WIND EVENT IN THE REGION TOWARD THE END OF THE WORK WEEK
GIVEN PROGGED CAA/PRESSURE RISE COUPLET. ACTIVE JET ACROSS THE PAC
LOOKS TO SUPPORT MILD ZONAL FLOW THROUGH THE MIDDLE/END OF NEXT
WEEK...KEEPING ARCTIC AIR BOTTLED UP IN NORTHERN CANADA AS RIDGING
REMAINS CONFINED TO LOWER LATITUDES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1021 AM MST SAT FEB 13 2016
MVFR/IFR CIGS OVER NORTHWEST INTO CENTRAL SOUTH DAKOTA WILL
CONTINUE THROUGH THIS AFTERNOON AND EVENING AS AREA OF SN/FZRA
DEVELOPS. THE HEAVIEST PRECIPITATION WILL BE THIS AFTERNOON INTO
TONIGHT. FOR NORTHEAST WYOMING INTO SOUTHWEST SOUTH
DAKOTA...SHOWERS WILL DEVELOP THIS AFTERNOON/EVENING WITH LCL MVFR
CIGS/VSBY. COLD FRONT CROSSES THE AREA LATE AFTERNOON/EVENING
WITH A PERIOD OF GUSTY NORTHWEST WINDS. VFR CONDITIONS EXPECTED
ACROSS THE AREA SUNDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR SDZ001-
002-014.
HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR SDZ012-024>031-
072>074.
WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ054>058-
071.
&&
$$
UPDATE...26
SHORT TERM...13
LONG TERM...JC
AVIATION...7
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
237 PM CST SAT FEB 13 2016
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES
WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL
OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST
ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA
AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION
IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO
THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING
PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS
SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE
INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM
FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA.
WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY
COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN
THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH
FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP
ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH
SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD.
OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE
INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE.
TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM
TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT
KABR AND THEN 17 AT KMBG.
MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE
SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE
FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO
THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL
MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE
FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING
SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF
MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH
AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT
ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT
HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB
OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE.
THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD)
AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS
EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF
AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN
SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN
MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY
DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE
WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME
OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO
WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS
IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL
FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE
TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT
NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM
PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN).
AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND
NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS
INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE
12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD
PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY
LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR
COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE
CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER
THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD
BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE
DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL
AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY
COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T
HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND
THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN
ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING
THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER
THAN IF IT OCCURRED DURING THE DAY.
ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST
WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO
25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND
WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW.
FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO
EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER
THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL
BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW
CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE
AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE
INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG
AND WEST OF THE MISSOURI RIVER.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 235 PM CST SAT FEB 13 2016
LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL
BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C
AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP
IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA.
THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO
FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS
TRICKY.
WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL
BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED
POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING
AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP
ISSUES AS THERE WILL BE WARM AIR IN PLACE.
YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER
WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS
LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE
SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO
TUESDAY NIGHT PER MODEL DATA.
TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY
THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS
AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL
SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE
SOUTHWEST CWA ON THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1149 AM CST SAT FEB 13 2016
EXPECT DETERIORATING CONDITIONS FROM WEST TO EAST THROUGH THE
AFTERNOON AND EVENING ACROSS THE REGION...AS A STORM SYSTEM
SLIDES EAST-SOUTHEAST ACROSS THE AREA. HAVE ALREADY STARTED TO
SEE SOME REDUCTIONS IN VISIBILITY AT KMBG AND EXPECT
VISIBILITIES TO FALL TO LOW END IFR AT ALL THE SITES AS THE
HEAVIEST SNOW MOVES THROUGH. COULD BRIEFLY SEE LIFR VISIBILITIES
FIRST OVER THE WEST LATE THIS AFTERNOON THROUGH LATE EVENING AND
THEN AT KABR/KATY BETWEEN 02-08Z (COMBINATION OF THE HEAVY SNOW
AND BLOWING SNOW BEFORE WINDS DIMINISH). EXPECT VISIBILITIES TO
RAPIDLY IMPROVE OVER THE WEST AFTER MIDNIGHT AS THE SYSTEM SHIFTS
TO THE EAST (VFR CONDITIONS WEST BY MID MORNING)...ALTHOUGH MVFR
CONDITIONS WILL PREVAIL THROUGH SUNDAY MORNING OVER THE EAST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003-
004-009-015-016-033>036-045-048-051.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY
FOR SDZ005>008-010-011-017>023-037.
MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY
FOR MNZ039-046.
&&
$$
SHORT TERM...SRF
LONG TERM...TDK
AVIATION...SRF
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
935 PM CST SUN FEB 14 2016
.UPDATE...
MESOSCALE UPDATE.
&&
.DISCUSSION...
INTERESTING EVOLUTION OF WINTER WEATHER EVENT HAS OCCURRED THIS
EVENING AS SURFACE FREEZING LINE HAS SAGGED BACK SOUTHWARD TO NEAR
THE I-40 CORRIDOR. THIS APPEARS TO HAVE BEEN DUE TO A WEAK WAVE
MOVING NORTHEASTWARD ALONG THE INVERTED TROUGH IN PLACE FROM SW TO
NE ACROSS THE CWA. 02Z HRRR AND 00Z NAM INSIST FREEZING LINE WILL
RETURN BACK NORTHWARD THIS EVENING/OVERNIGHT...AND THIS APPEARS TO
BE UNDERWAY AS TEMPERATURES HAVE RISEN INTO THE LOW 30S AT CKV AND
INTO SOUTHERN KY. HOWEVER...LIGHT SLEET/FZRA WILL CONTINUE FOR
ANOTHER HOUR OR TWO FOR THE I-40 CORRIDOR COUNTIES...AND LIKELY
LINGER PAST MIDNIGHT FOR THE KY BORDER COUNTIES WHERE TRAVEL
IMPACTS REMAIN SIGNIFICANT. THUS HAVE EXTENDED THE WWA UNTIL 12Z
FOR THE NORTHWESTERN COUNTIES AS TRAVEL WILL REMAIN HAZARDOUS
THERE THROUGH THE OVERNIGHT HOURS. ALTHOUGH MOST OBS ARE WELL
ABOVE FREEZING IN THE CENTRAL PLATEAU COUNTIES...KEPT THE ADVISORY
GOING FOR PUTNAM/WHITE/CUMBERLAND/VAN BUREN AS SOME AREAS REMAIN
BELOW FREEZING...MAINLY THE HIGHER ELEVATIONS. UPDATED PRODUCTS
OUT SHORTLY.
&&
.AVIATION...
00Z TAF DISCUSSION.
POOR FLYING WEATHER NEXT 24 HOURS IN MIDDLE TENNESSEE AND ADJACENT
AREAS DUE TO LOW CEILINGS AND VISIBILITIES. FREEZING RAIN WILL
CONTINUE AT CLARKSVILLE FOR THE NEXT HOUR OR TWO BEFORE CHANGING
TO RAIN. RAIN NOW FALLING AT NASHVILLE. TEMPERATURES WILL SLOWLY
RISE OVERNIGHT TO AROUND 40 DEGREES BY DAYBREAK MONDAY MOST AREAS.
SURFACE LOW CENTRAL TEXAS WITH INVERTED TROUGH NORTHEAST THROUGH
SOUTHERN ARKANSAS...CENTRAL TENNESSEE INTO THE WEST VIRGINIA WILL
REMAIN INSITU NEXT 24 HOURS WHILE ACTING AS THE FOCUS FOR
RAIN...SOME HEAVY AT TIMES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CLAY-
CUMBERLAND-FENTRESS-JACKSON-MACON-MONTGOMERY-OVERTON-PICKETT-
PUTNAM-ROBERTSON-STEWART-SUMNER-VAN BUREN-WHITE.
&&
$$
AVIATION.........................01/BOYD
SHORT/LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
850 PM CST SUN FEB 14 2016
.UPDATE...
MAIN CHALLENGE IN THE OVERNIGHT PERIOD IS ONCE AGAIN THE POTENTIAL
FOR FOG OVERNIGHT AND TOMORROW MORNING. A WEAK FRONT WILL BE
APPROACHING THE REGION OVERNIGHT AND WE SHOULD SEE WINDS GO LIGHT
AND VARIABLE AHEAD OF THE BOUNDARY. THIS SHOULD ALLOW FOR MOISTURE
TO POOL AND FOR FOG PRODUCTION TO OCCUR. THE BEST LOCATION FOR
THIS TO HAPPEN IS AREAS NEAR BEXAR COUNTY AND TO THE WEST. FARTHER
EAST...SOUTHWEST WINDS WILL PREVAIL WHICH SHOULD KEEP MOST OF THE
FOG AT BAY. UPPED THE WORDING TO AREAS OF FOG FOR THE CENTRAL
PORTIONS OF THE CWA AS THE HRRR IS SHOWING SOME POSSIBLE DENSE
FOG.
&&
.PREV DISCUSSION... /ISSUED 550 PM CST SUN FEB 14 2016/
AVIATION DISCUSSION...FOR 00Z TAF PERIOD...
SOUTHERLY WINDS WILL CONTINUE TO BRING MOISTURE INTO THE AREA
TONIGHT WHICH WILL RESULT IN LOW CIG DEVELOPMENT OVERNIGHT IN
ADVANCE OF AN APPROACHING COLD FRONT TOMORROW MORNING. EXPECTING
IFR AT LEAST FOR THE I35 TERMINALS SHORTLY AFTER MIDNIGHT WITH
KSAT/KSSF FALLING TO LIFR. THESE CONDITIONS WILL LIKELY PERSIST
UNTIL THE FRONTAL PASSAGE WHICH IS FORECAST TO MOVE THROUGH KAUS
AROUND 14Z AND KSAT/KSSF BY 16Z. THEN VFR IS EXPECTED WITH GUSTY
WINDS OF 10-15 KTS GUSTING TO 20-25 DURING THE AFTERNOON.
PREV DISCUSSION... /ISSUED 233 PM CST SUN FEB 14 2016/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
UPPER AIR ANALYSIS THIS MORNING SHOWED ZONAL FLOW ACROSS MOST OF
THE SOUTHERN PART OF THE COUNTRY WITH A RIDGE OFF THE WEST COAST.
AT THE SURFACE...WINDS WERE FROM THE SOUTH AHEAD OF A COLD FRONT
THAT WAS STRETCHED ACROSS WEST TEXAS. A SHALLOW UPPER LEVEL TROUGH
WILL DEVELOP TONIGHT AND MOVE ACROSS TEXAS AND BRING NORTHWESTERLY
FLOW TOMORROW. THIS WILL BRING THE COLD FRONT THROUGH BY NOON
TUESDAY. THERE IS LIMITED MOISTURE AVAILABLE TO THIS SYSTEM...SO
ONLY SLIGHT CHANCE FOR DRIZZLE ACROSS THE EASTERN COUNTIES. FOG IS
LIKELY ACROSS THE SOUTH AND EAST MONDAY MORNING. THE FRONT WILL
USHER IN NORTHERLY WINDS AND DRIER AIR.
LONG TERM (TUESDAY THROUGH SUNDAY)...
TUESDAY AND WEDNESDAY TEXAS WILL LIE BETWEEN AN UPPER LEVEL TROUGH
DIGGING OVER THE EAST AND A RIDGE BUILDING OVER THE WEST. THIS
WILL KEEP THE UPPER FLOW NORTHWESTERLY. DURING THIS TIME AT THE
SURFACE HIGH PRESSURE WILL MOVE ACROSS OUR CWA SWITCHING THE WINDS
AROUND TO THE SOUTH BY WEDNESDAY. THIS WILL CONTINUE DRY WEATHER.
THE UPPER PATTERN WILL BECOME PROGRESSIVE WEDNESDAY NIGHT AND THE
RIDGE WILL MOVE ACROSS TEXAS THURSDAY. MOST OF THE SECOND HALF OF
THE WEEK WILL CONTINUE TO BE DRY...BUT BY SATURDAY THERE MAY BE
DEEP ENOUGH MOISTURE AND SUFFICIENT ISENTROPIC LIFT TO PRODUCE
LIGHT RAIN. SUNDAY A COLD FRONT WILL APPROACH OUR CWA FROM THE
NORTH AND THERE WILL BE A CHANCE FOR SHOWERS AND POSSIBLY SOME
THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 56 76 49 80 51 / 10 - 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 53 75 44 78 46 / 10 - 0 0 0
NEW BRAUNFELS MUNI AIRPORT 53 78 47 80 49 / 10 - 0 0 0
BURNET MUNI AIRPORT 50 73 45 78 48 / - 0 0 0 0
DEL RIO INTL AIRPORT 48 81 48 82 51 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 53 73 45 78 47 / 10 0 0 0 0
HONDO MUNI AIRPORT 48 80 45 80 48 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 53 76 46 78 48 / 10 - 0 0 0
LA GRANGE - FAYETTE REGIONAL 56 76 47 79 49 / 10 10 0 0 0
SAN ANTONIO INTL AIRPORT 53 77 48 79 51 / - - 0 0 0
STINSON MUNI AIRPORT 53 79 48 80 50 / - - 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...HAMPSHIRE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
754 PM CST SUN FEB 14 2016
.UPDATE...
A LOOSELY ORGANIZED FRONTAL ZONE CURRENTLY STRETCHES WEST-TO EAST
ACROSS THE ARKLATEX REGION WITH A LIGHT AND DISORGANIZED WIND
FIELD ASSOCIATED WITH IT. THE BOUNDARY WILL BECOME MORE ORGANIZED
OVER THE NEXT SEVERAL HOURS AS A SHORTWAVE OVER WEST-CENTRAL
TEXAS CROSSES OVERHEAD. LIFT FROM THE SHORTWAVE AND PERHAPS SOME
ADDED FRONTOGENETIC FORCING SHOULD LEAD TO SHOWER AND ISOLATED
THUNDERSTORM DEVELOPMENT DURING THE LATE EVENING AND OVERNIGHT
HOURS...MAINLY FOR AREAS ALONG AND EAST OF THE I-35 CORRIDOR.
SHOWERS WILL LINGER INTO THE MORNING BEFORE MOVING QUICKLY EAST OF
THE REGION AS THE SHORTWAVE HEADS FOR THE MISSISSIPPI VALLEY.
SLIGHT ADJUSTMENT TO THE POP GRIDS WERE MADE TO ACCOUNT FOR THE
LATEST HIGH-RES GUIDANCE ADVERTISING BEST OVERALL RAIN CHANCES IN
THE NORTHEASTERN-MOST COUNTIES. OTHERWISE ONLY MINOR GRID
ADJUSTMENTS HAVE BEEN MADE.
30
&&
.AVIATION...
/ISSUED 602 PM CST SUN FEB 14 2016/
/00Z TAFS/
A COLD FRONT IS CURRENTLY APPROACHING THE RED RIVER VALLEY AND NW
COUNTIES WITH WINDS ACROSS THE DFW AREA AIRPORTS GENERALLY
VARIABLE 5 KTS OR LESS...WITH SSW WINDS AT WACO STILL AROUND 10
KTS. TIMING THE COLD FRONT AND SWITCH TO NORTH FLOW A LITTLE
TRICKY...AS ARE CIG FORECASTS. FOR NOW...WILL PEG A 04Z-05Z TIME
FRAME FOR DFW AREA AIRPORTS WITH A WEAK WIND SHIFT TO THE NNE 5-10
KTS AT FIRST...THEN AS THE FRONTAL INVERSION DEEPENS...GOING NNW
OR NW 10-15 KTS OVERNIGHT. WACO WILL LIKELY STAY SOUTH FLOW ALL
NIGHT WITH INITIAL FROPA MORE TOWARD 12Z SINCE IT WILL BE SLOW TO
MOVE UNTIL THE SHORTWAVE ALOFT CATCHES UP AND HELPS PUSH THE FRONT
ALONG FASTER TOWARD SUNRISE MONDAY WITH NW WINDS 15 KTS THROUGH
THE DAY WITH OCCASIONAL GUSTS TO 20 KTS POSSIBLE...BEFORE
DECOUPLING TOWARD 00Z TUESDAY.
AS FOR CIGS AND FLIGHT RULES...THE INITIAL FROPA WILL BE VERY
SHALLOW WITH LOW MVFR/HIGH IFR CONDITIONS THROUGH THE OVERNIGHT
HOURS FOR DFW AREA AIRPORTS. AS THE CAA INCREASES AND THE FRONTAL
PUSH INCREASES WITH THE SHORTWAVE PASSING THROUGH...CIGS WILL RISE
BACK INTO HIGH MVFR LATER IN THE MORNING THEN BECOME VFR BY 18Z
AND AFTER. THE ONE CAVEAT HERE IS NOTHING IS SEEN UPSTREAM AS FAR
AS CIGS QUITE THIS LOW AND THEY WOULD NEED TO BACK BUILD WSW IN
BEHIND THE INITIAL SHALLOW FRONTAL PUSH. THE NAM12 AND RUC OPS40
SOUNDINGS SHOW THIS WELL...THOUGH THE GFS BUFR SOUNDINGS DISAGREE.
PER COORDINATION WITH OUR PARTNERS AT THE ZFW CWSU...I HAVE LEFT
OUT VCSH/VCTS WORDING WITH THE FROPA AFTER 03Z AT THIS TIME WITH
ONLY ISOLATED CHANCES EXPECTED AT AIRPORTS. IT DEFINITELY BEARS
WATCHING HOWEVER. WACO WILL HAVE SIMILAR TRENDS...JUST DELAYED
3-6 HRS.
IN A NUTSHELL...THE EVOLUTION OF CIGS AND CONVECTION IS NOT CLEAR
CUT WITH THE MODELS STRUGGLING AND DISAGREEING. WILL WATCH AND
AMEND AS CONDITIONS DEVELOP LATER TONIGHT AND DEVELOPMENT OF ALL
VARIABLES BECOMES MORE EVIDENT.
05/
&&
.PREV DISCUSSION... /ISSUED 246 PM CST SUN FEB 14 2016/
LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS MUCH OF NORTH
TEXAS THROUGH THE EVENING AHEAD OF AN APPROACHING COLD FRONT. AS
OF 2 PM THE FRONT HAD ALREADY REACHED THE WESTERN ZONES BUT SHOULD
NOT MOVE FARTHER EAST UNTIL THE PASSAGE OF A FAST MOVING
SHORTWAVE. MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE WILL
REMAIN NEAR THE RED RIVER TONIGHT AND THE BEST RAIN CHANCES WILL
RESIDE GENERALLY EAST OF INTERSTATE 35 AND NORTH OF INTERSTATE 20.
MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO SUPPORT AT LEAST
ISOLATED THUNDERSTORMS (700 TO 500 MB DELTA T ON THE ORDER OF 17
TO 19 DEGREES C). RAIN CHANCES WILL END QUICKLY MONDAY MORNING
ONCE THE SHORTWAVE TROUGH AXIS MOVES EAST AND DRIER AIR FILTERS IN
BEHIND THE COLD FRONT.
TEMPERATURES MONDAY WILL STILL BE MILD FOR MID FEBRUARY DUE TO
ABUNDANT SUN AND ONLY WEAK COLD AIR ADVECTION. HIGHS MONDAY
AFTERNOON WILL RANGE FROM THE MIDDLE 60S TO THE LOWER 70S.
UPPER LEVEL HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY
THROUGH THURSDAY AND RESULT IN WARM TEMPERATURES AND LITTLE CHANCE
FOR RAIN. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S TO
LOWER 80S WITH LOWS IN THE 40S AND 50S.
THE UPPER RIDGE WILL BUILD TOWARD THE EAST COAST THURSDAY
NIGHT/FRIDAY WHILE A SHORTWAVE MOVES FROM THE ROCKIES TO THE
CENTRAL PLAINS. ALTHOUGH CLOUD COVER WILL INCREASE ON FRIDAY IN
RESPONSE TO A SURGE IN LOW LEVEL MOISTURE...TEMPERATURES WILL
STILL BE IN THE 70S AND LOWER 80S FRIDAY AFTERNOON.
THE UPPER PATTERN WILL BECOME ZONAL LATE IN THE WEEKEND THROUGH
EARLY NEXT WEEK WITH A SHORTWAVE PROGGED TO MOVE QUICKLY ACROSS
THE STATE SATURDAY NIGHT/SUNDAY. AS A RESULT...SOME RAIN/STORM
CHANCES WILL RETURN TO THE REGION. WILL LEAVE POPS LOW FOR NOW
DUE TO TIMING UNCERTAINTIES WITH THE SHORTWAVE AND THE ASSOCIATED
COLD FRONT.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 53 69 46 73 46 / 30 10 0 0 0
WACO, TX 51 71 42 76 43 / 30 10 0 0 0
PARIS, TX 49 65 42 69 40 / 50 30 5 0 0
DENTON, TX 46 67 44 72 42 / 30 10 0 0 0
MCKINNEY, TX 50 65 41 71 42 / 40 20 0 0 0
DALLAS, TX 53 70 48 74 46 / 30 10 0 0 0
TERRELL, TX 54 68 41 72 43 / 40 30 5 0 0
CORSICANA, TX 57 69 46 74 46 / 30 30 0 0 0
TEMPLE, TX 53 72 45 78 45 / 20 10 0 0 0
MINERAL WELLS, TX 45 68 40 75 43 / 10 10 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
602 PM CST SUN FEB 14 2016
.AVIATION...
/00Z TAFS/
A COLD FRONT IS CURRENTLY APPROACHING THE RED RIVER VALLEY AND NW
COUNTIES WITH WINDS ACROSS THE DFW AREA AIRPORTS GENERALLY
VARIABLE 5 KTS OR LESS...WITH SSW WINDS AT WACO STILL AROUND 10
KTS. TIMING THE COLD FRONT AND SWITCH TO NORTH FLOW A LITTLE
TRICKY...AS ARE CIG FORECASTS. FOR NOW...WILL PEG A 04Z-05Z TIME
FRAME FOR DFW AREA AIRPORTS WITH A WEAK WIND SHIFT TO THE NNE 5-10
KTS AT FIRST...THEN AS THE FRONTAL INVERSION DEEPENS...GOING NNW
OR NW 10-15 KTS OVERNIGHT. WACO WILL LIKELY STAY SOUTH FLOW ALL
NIGHT WITH INITIAL FROPA MORE TOWARD 12Z SINCE IT WILL BE SLOW TO
MOVE UNTIL THE SHORTWAVE ALOFT CATCHES UP AND HELPS PUSH THE FRONT
ALONG FASTER TOWARD SUNRISE MONDAY WITH NW WINDS 15 KTS THROUGH
THE DAY WITH OCCASIONAL GUSTS TO 20 KTS POSSIBLE...BEFORE
DECOUPLING TOWARD 00Z TUESDAY.
AS FOR CIGS AND FLIGHT RULES...THE INITIAL FROPA WILL BE VERY
SHALLOW WITH LOW MVFR/HIGH IFR CONDITIONS THROUGH THE OVERNIGHT
HOURS FOR DFW AREA AIRPORTS. AS THE CAA INCREASES AND THE FRONTAL
PUSH INCREASES WITH THE SHORTWAVE PASSING THROUGH...CIGS WILL RISE
BACK INTO HIGH MVFR LATER IN THE MORNING THEN BECOME VFR BY 18Z
AND AFTER. THE ONE CAVEAT HERE IS NOTHING IS SEEN UPSTREAM AS FAR
AS CIGS QUITE THIS LOW AND THEY WOULD NEED TO BACK BUILD WSW IN
BEHIND THE INITIAL SHALLOW FRONTAL PUSH. THE NAM12 AND RUC OPS40
SOUNDINGS SHOW THIS WELL...THOUGH THE GFS BUFR SOUNDINGS DISAGREE.
PER COORDINATION WITH OUR PARTNERS AT THE ZFW CWSU...I HAVE LEFT
OUT VCSH/VCTS WORDING WITH THE FROPA AFTER 03Z AT THIS TIME WITH
ONLY ISOLATED CHANCES EXPECTED AT AIRPORTS. IT DEFINITELY BEARS
WATCHING HOWEVER. WACO WILL HAVE SIMILAR TRENDS...JUST DELAYED
3-6 HRS.
IN A NUTSHELL...THE EVOLUTION OF CIGS AND CONVECTION IS NOT CLEAR
CUT WITH THE MODELS STRUGGLING AND DISAGREEING. WILL WATCH AND
AMEND AS CONDITIONS DEVELOP LATER TONIGHT AND DEVELOPMENT OF ALL
VARIABLES BECOMES MORE EVIDENT.
05/
&&
.PREV DISCUSSION... /ISSUED 246 PM CST SUN FEB 14 2016/
LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS MUCH OF NORTH
TEXAS THROUGH THE EVENING AHEAD OF AN APPROACHING COLD FRONT. AS
OF 2 PM THE FRONT HAD ALREADY REACHED THE WESTERN ZONES BUT SHOULD
NOT MOVE FARTHER EAST UNTIL THE PASSAGE OF A FAST MOVING
SHORTWAVE. MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE WILL
REMAIN NEAR THE RED RIVER TONIGHT AND THE BEST RAIN CHANCES WILL
RESIDE GENERALLY EAST OF INTERSTATE 35 AND NORTH OF INTERSTATE 20.
MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO SUPPORT AT LEAST
ISOLATED THUNDERSTORMS (700 TO 500 MB DELTA T ON THE ORDER OF 17
TO 19 DEGREES C). RAIN CHANCES WILL END QUICKLY MONDAY MORNING
ONCE THE SHORTWAVE TROUGH AXIS MOVES EAST AND DRIER AIR FILTERS IN
BEHIND THE COLD FRONT.
TEMPERATURES MONDAY WILL STILL BE MILD FOR MID FEBRUARY DUE TO
ABUNDANT SUN AND ONLY WEAK COLD AIR ADVECTION. HIGHS MONDAY
AFTERNOON WILL RANGE FROM THE MIDDLE 60S TO THE LOWER 70S.
UPPER LEVEL HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY
THROUGH THURSDAY AND RESULT IN WARM TEMPERATURES AND LITTLE CHANCE
FOR RAIN. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S TO
LOWER 80S WITH LOWS IN THE 40S AND 50S.
THE UPPER RIDGE WILL BUILD TOWARD THE EAST COAST THURSDAY
NIGHT/FRIDAY WHILE A SHORTWAVE MOVES FROM THE ROCKIES TO THE
CENTRAL PLAINS. ALTHOUGH CLOUD COVER WILL INCREASE ON FRIDAY IN
RESPONSE TO A SURGE IN LOW LEVEL MOISTURE...TEMPERATURES WILL
STILL BE IN THE 70S AND LOWER 80S FRIDAY AFTERNOON.
THE UPPER PATTERN WILL BECOME ZONAL LATE IN THE WEEKEND THROUGH
EARLY NEXT WEEK WITH A SHORTWAVE PROGGED TO MOVE QUICKLY ACROSS
THE STATE SATURDAY NIGHT/SUNDAY. AS A RESULT...SOME RAIN/STORM
CHANCES WILL RETURN TO THE REGION. WILL LEAVE POPS LOW FOR NOW
DUE TO TIMING UNCERTAINTIES WITH THE SHORTWAVE AND THE ASSOCIATED
COLD FRONT.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 53 69 46 73 46 / 30 10 0 0 0
WACO, TX 51 71 42 76 43 / 30 10 0 0 0
PARIS, TX 49 65 42 69 40 / 50 30 5 0 0
DENTON, TX 46 67 44 72 42 / 30 10 0 0 0
MCKINNEY, TX 50 65 41 71 42 / 40 20 0 0 0
DALLAS, TX 53 70 48 74 46 / 30 10 0 0 0
TERRELL, TX 54 68 41 72 43 / 40 30 5 0 0
CORSICANA, TX 57 69 46 74 46 / 30 30 0 0 0
TEMPLE, TX 53 72 45 78 45 / 20 10 0 0 0
MINERAL WELLS, TX 45 68 40 75 43 / 10 10 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/79
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1220 PM CST SAT FEB 13 2016
.AVIATION...
MVFR CIGS NOTED ACROSS THE SWRN TWO THIRDS OF THE CWFA THIS MORN/
AFTN...GENERALLY ALONG AND SOUTH OF THE WEAK FRONTAL BOUNDARY. AS
THE LINE WEAKENS/MOVES BACK FURTHER INLAND THIS EVENING/OVERNIGHT
WE COULD SEE WIDESPREAD LOWER/MVFR CIGS ACROSS SE TX BY SAT MORN.
SOME SPOTS MIGHT SEE PATCHY FOG OVERNIGHT AS WELL...BUT FOG COULD
BE MORE PREVALENT SUN MORN. 41
&&
.PREV DISCUSSION... /ISSUED 925 AM CST SAT FEB 13 2016/
UPDATE...
FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET
DENSE FOG ADVISORY EXPIRE.
BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO
SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY
WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER
THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD
COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL
FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN
UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING
TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF
CHANGE FROM THE PREVIOUS UPDATE.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20
HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30
GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...99
AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
925 AM CST SAT FEB 13 2016
.UPDATE...
FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET
DENSE FOG ADVISORY EXPIRE.
BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO
SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY
WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER
THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD
COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL
FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN
UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING
TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF
CHANGE FROM THE PREVIOUS UPDATE.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20
HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30
GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1041 PM CST FRI FEB 12 2016
.DISCUSSION...SEE AVIATION SECTION FOR 06Z TAFS.
&&
.AVIATION...HIGHER BOUNDARY LAYER MOISTURE IS OVER THE COASTAL
PLAINS INTO THE EASTERN BRUSH COUNTRY LATE THIS EVENING WHILE
WINDS DIMINISHED. TEMPERATURE/DEWPOINT DEPRESSIONS ARE NEAR
ZERO OVER THE VICTORIA CROSSROADS. FOG/MVFR VSBYS EXPECTED TO
DEVELOP 05-06Z IN THIS REGION WITH CONDITIONS DETERIORATING TO
LIFR WITH DENSE FOG BY 07-08Z AND CONTINUE UNTIL AROUND 15Z.
TIMING FOR FOG IN THE ALI/CRP AREA WILL BE DELAYED AN HOUR OR TWO
WITH LIFR CONDS FORMING BY 08-09Z. EXPECT THE LOW CLOUDS AND
FOG...IFR CIGS AND MVFR VSBYS...WILL REACH LRD AREA BY 11Z WITH
LIFR VSBYS POSSIBLE IN NEAR DENSE FOG. VSBYS ARE EXPECTED TO
IMPROVE BY 15-16Z TO VFR WITH MVFR CIGS HOLDING OVER VCT AREA
THROUGH THE LATE MORNING BEFORE LIFTING. STRATUS IS EXPECTED TO
MOVE BACK INTO THE VCT AREA AROUND 03Z SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 914 PM CST FRI FEB 12 2016/
DISCUSSION...DEWPOINT TEMPERATURES HAVE RISEN TO THE UPPER 50S
TO NEAR 60 OVER THE COASTAL PLAINS THIS EVENING. WINDS WILL
CONTINUE TO DIMINISH TONIGHT AS A WEAK FRONTAL BOUNDARY FROM
NORTH OF HOUSTON TO SOUTH OF SAN ANTONIO REMAINS ESSENTIAL
QUASISTATIONARY TONIGHT. TEMP-DEWPOINT DEPRESSIONS WERE THE
LOWEST AROUND THE MID COAST AT 03Z. 00Z HRRR ALONG WITH 00Z
NAM SHOW FOG WILL FORM OVER THE MID COAST REGION INITIALLY
JUST AFTER 06Z AND SPREAD WESTWARD INTO THE BRUSH COUNTRY
OVERNIGHT. ADDED CALHOUN AND ARANSAS COUNTIES INTO THE DENSE
FOG ADVISORY. MAY NEED TO HAVE ADVISORY FOR WEBB AND LA SALLE
COUNTIES LATER TONIGHT BUT NOT CONFIDENT ENOUGH AT THIS POINT
TO INCLUDE IN THE ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 55 74 57 78 56 / 0 10 10 10 0
VICTORIA 50 71 54 75 57 / 0 10 10 10 10
LAREDO 54 82 55 83 53 / 0 0 0 0 0
ALICE 52 78 54 82 55 / 0 0 10 10 0
ROCKPORT 56 70 60 73 60 / 0 10 10 10 10
COTULLA 50 80 54 83 51 / 0 0 0 0 0
KINGSVILLE 52 77 54 78 56 / 0 0 0 10 10
NAVY CORPUS 56 71 60 73 59 / 0 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY FROM 2 AM TO 10 AM CST SATURDAY FOR THE
FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD...
JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES...
REFUGIO...SAN PATRICIO...VICTORIA.
GM...NONE.
&&
$$
TMT/89...AVIATION
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1013 PM MST FRI FEB 12 2016
.UPDATE...
ISSUED AT 1010 PM MST FRI FEB 12 2016
WEBCAMS NEAR CARPENTER IN EASTERN LARAMIE COUNTY...ALONG WITH
DECREASING VISIBILITIES REPORTED AT PINE BLUFFS...LED ME TO EXPAND
THE DENSE FOG ADVISORY FURTHER WEST. LATEST HRRR GUIDANCE AND
11-3.9U SATELLITE IMAGERY SHOWING THIS AS WELL...SO CONFIDENCE IS
HIGH ON EXPANDING THIS ADVISORY. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 806 PM MST FRI FEB 12 2016
LATEST IBM AND SNY OBSERVATIONS IN THE SOUTHERN PANHANDLE SHOWING
VISIBILITIES DOWN NEAR 1/4 MILE. THESE VISIBILITY REPORTS HAVE NOT
CHANGED MUCH OVER THE PAST HOUR. LATEST 11-3.9U SATELLITE IMAGERY
SHOWING THE LOW CLOUDS/FOG SPREADING WEST TOWARDS LARAMIE COUNTY
NEAR PINE BLUFFS. WILL CONTINUE TO MONITOR AND MAY NEED TO EXTEND
THE ADVISORY FURTHER WEST. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 708 PM MST FRI FEB 12 2016
GETTINGS REPORTS FROM THE SIDNEY AND KIMBALL ASOS/AWOS OF REDUCED
VISIBILITIES IN FOG ALREADY THIS EVENING. CERTAINLY NEED TO WATCH
CONDITIONS TO SEE IF THIS FOG BECOMES MORE WIDESPREAD. WENT AHEAD
AND EXPANDED FOG WEST UP THE PLATTE RIVER VALLEY INTO TORRINGTON
AND ACROSS THE NORTHERN PANHANDLE AS WELL. WILL CONTINUE
MONITORING. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM MST FRI FEB 12 2016
EARLY AFTERNOON WATER VAPOR IMAGERY SHOWED A UPPER RIDGE AXIS
SITUATED OVER THE INTERMTN WEST WITH A DEEP UPPER TROUGH FROM
HUDSON BAY CANADA TO FL. NORTHWEST FLOW ALOFT PREVAILED ACROSS
THE FRONT RANGE AND HIGH PLAINS. THE LEADING EDGE OF A SHALLOW
COLD AIR MASS HAD DRIFTED WEST INTO THE EASTERN 1/3 OF THE COWBOY
STATE. EAST-NORTHEAST WINDS AND WESTERN EDGE OF STRATUS CLOUD
DECK EXTENDED FROM NEAR LUSK WY TO JUST WEST OF SIDNEY NE.
TEMPERATURES EAST OF THE FRONT WERE IN THE 20S AND 30S...WHILE
WESTERLY WINDS AND 40S PREVAILED TO THE WEST.
DURING THE NEXT 12-18 HOURS...PRIMARY CONCERNS WILL DEAL WITH
POTENTIAL FOR PATCHY FREEZING DRIZZLE AND FOG OVER WESTERN
NE PANHANDLE ASSOCIATED WITH THE SHALLOW COLD AIR MASS. THERE
IS GOOD MODEL AGREEMENT PROGGING THE ARCTIC FRONT TO REMAIN
NEARLY STATIONARY TONIGHT ACROSS THE EASTERN WY PLAINS THEN
SLOWLY SHIFTING EAST INTO WESTERN NE SATURDAY MORNING. LATEST
GFS/NAM BUFR SOUNDINGS INDICATE A NEARLY SATURATED LAYER FROM
700-950MB ALONG WITH A LIGHT LOW LEVEL SOUTHEASTERLY FLOW
TONIGHT AND EARLY SATURDAY MORNING OVER WESTERN NE. PATCHY
FREEZING DRIZZLE AND FOG DEVELOPING LATER THIS EVENING AND
LINGERING THROUGH MID-LATE MORNING. THE FOG/DRIZZLE MAY EXTEND
AS FAR WEST AS A LUSK WY-KIMBALL NE LINE...BUT CONFIDENCE NOT
HIGH ATTM AND NEXT SHIFT CAN REEVALUATE WITH 00Z MODEL GUIDANCE.
A SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST TONIGHT WILL
QUICK MOVE ACROSS THE ID/MT SATURDAY MORNING...NORTHERN WY
SATURDAY AFTERNOON...AND SD/NORTHERN NE SATURDAY NIGHT. THIS
SHORTWAVE WILL INCREASE THE LEESIDE SURFACE PRESSURE GRADIENT
WITH THE POTENTIAL FOR A GAP WIND EPISODE FOR ARLINGTON AND
BORDEAUX SATURDAY AFTERNOON AND EVENING. THE CRAIG-CASPER HEIGHT
700-850MB GRADIENT EXCEEDS 60M BY 21Z SATURDAY...AND DECREASED
BELOW 50M BY 06Z SUNDAY. WINDS AT 700MB PEAK NEAR 60 KT AT 00Z
SUNDAY. ISSUED A HIGH WIND WATCH FOR WY ZONES 106 AND 110 FROM
NOON TO 9 PM SATURDAY FOR THE POTENTIAL FOR WEST WIND GUSTS TO
60 MPH. SATURDAY WILL BE MILDER...ESPECIALLY EAST OF I-25 AS
WESTERLY DOWNSLOPING WINDS SCOUR OUT THE SHALLOW COLD AIR MASS.
AFTER A BRIEF LULL IN THE HIGH WINDS SATURDAY NIGHT...THEY PICK
UP AGAIN SUNDAY MORNING WITH THE POTENTIAL FOR HIGH WINDS SPREADING
EAST TO I-25 SUNDAY AFTERNOON. IF THE MODELS REMAIN
CONSISTENT...HIGH WIND HEADLINES MAY BE ISSUED SATURDAY. SUNDAY
WILL BE 5-10 DEGREES FOLLOWING THE PASSAGE OF A PACIFIC COLD FRONT.
SOME LIGHT PRECIPITATION DEVELOPS INITIALLY ACROSS NORTHEAST
WY/WESTERN SD SATURDAY EVENING AND SHIFTS EAST SATURDAY NIGHT.
PACIFIC MOISTURE INCREASES WEST OF THE LARAMIE RANGE SUNDAY
MORNING WITH LIGHT SNOW BECOMING MORE WIDESPREAD SUNDAY
AFTERNOON. THERE IS A SLIGHT CHANCE OF LIGHT SNOW SPREADING EAST
ONTO THE SOUTHEAST WY PLAINS SUNDAY NIGHT. MOST OF THE
ACCUMULATING SNOW WILL OCCUR OVER THE SNOWY/SIERRA MADRE RANGES
WITH UP TO 3 INCHES POSSIBLE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 200 PM MST FRI FEB 12 2016
MONDAY...RELATIVELY MOIST NORTHWEST FLOW ALOFT WILL PRODUCE
OROGRAPHIC SNOWFALL ACROSS THE SNOWY AND SIERRA MADRE RANGES WITH
A SLIGHT CHANCE OF PRECIPITATION NORTH OF A DOUGLAS TO SCOTTSBLUFF
LINE.
TUESDAY...DRIER AND WARMER AS HEIGHTS AND THICKNESSES RISE AND THE
ATMOSPHERE DRIES OUT SOMEWHAT.
WEDNESDAY...PERHAPS THE WARMEST DAY NEXT WEEK AS THE RIDGE ALOFT
MOVES OVERHEAD AND SURFACE LEE TROUGHING BECOMES WELL ESTABLISHED
WITH VERY DRY ATMOSPHERE PROMOTING WARMING TEMPERATURES.
THURSDAY...CONTINUED MILD IN THE WARM SECTOR AHEAD OF APPROACHING
COLD FRONT. SOME OROGRAPHIC SNOW SHOWERS POSSIBLE NEAR THE SNOWY
AND SIERRA MADRE RANGES LATE IN THE DAY WITH A SHORTWAVE TROUGH
APPROACHING.
FRIDAY...COOLER IN THE WAKE OF THE SHORTWAVE TROUGH ALOFT AND ITS
ASSOCIATED COLD FRONT PASSAGE...THOUGH STILL RELATIVELY MILD FOR
MID FEBRUARY BASED ON PROJECTED HEIGHTS AND THICKNESSES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1010 PM MST FRI FEB 12 2016
BACKDOOR FRONT TO REMAIN ALONG THE EAST SLOPES OF THE LARAMIE
RANGE THROUGH THE OVERNIGHT HOURS. EASTERLY UPSLOPING WINDS OVER
THE PANHANDLE WILL CONTINUE WIDESPREAD IFR/LIFR CONDITIONS FOR OUR
NEBRASKA PANHANDLE AIRPORTS AT LEAST THROUGH 18Z. FOLLOWED LATEST
HRRR GUIDANCE AND CONFIDENCE IS HIGH THAT LOW CONDITIONS WILL
CONTINUE. WEST WINDS RETURN AFTER 18Z THAT WILL SCOUR OUT THE
LOWER STRATUS.
&&
.FIRE WEATHER...
ISSUED AT 200 PM MST FRI FEB 12 2016
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND WITH COOL TO MILD
TEMPERATURES AND RESIDUAL SNOW COVER. A NORTH-SOUTH ORIENTED COLD
FRONT OVER THE HIGH PLAINS WILL SHIFT EASTWARD SATURDAY AS A QUICK
MOVING UPPER LEVEL DISTURBANCE MOVES INTO NORTHERN WYOMING. THIS
DISTURBANCE WILL TIGHTEN THE LEESIDE SURFACE PRESSURE GRADIENT
WITH WEST WINDS BECOMING STRONG AND GUSTY ACROSS MUCH OF SOUTHEAST
WYOMING. THE WINDY CONDITIONS WILL CONTINUE SUNDAY AS WELL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING
FOR WYZ106-110.
DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR WYZ119.
NE...DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR NEZ054-055.
&&
$$
UPDATE...GCC
SHORT TERM...MAJ
LONG TERM...RUBIN
AVIATION...GCC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST SUN FEB 14 2016
.UPDATE...
ISSUED AT 652 PM MST SUN FEB 14 2016
UPSTREAM IN SOUTHWESTERN WYOMING SNOWED HAS STOPPED FOR NOW AS
THE BULK OF ENERGY HAS MOVED DOWNSTREAM ALONG THE CONTINENTAL
DIVIDE AREAS OF CENTRAL COLORADO. ALLOWED WINTER WEATHER
ADVISORIES TO CONTINUE THROUGH TOMORROW DESPITE THE OBVIOUS BREAK
IN SNOWFALL...WHICH HAS ALREADY BEGUN AROUND THE STEAMBOAT SPRINGS
AREA AND WILL SOON BEGIN IN THE FLATTOPS. THE SHORT TERM MODELS
ARE INDICATING THE BREAK TO LAST THROUGHOUT THE NEXT 6 TO 12
HOURS...BUT SNOW PICKING UP TOWARD DAYBREAK FROM THE NORTHWEST
AGAIN. TOMORROW/S SNOW IS STILL LOOKING MORE OROGRAPHICALLY
DRIVEN AS OPPOSED TO TODAY/S DISTURBANCE WHICH ALLOWED SNOWFALL
ALONG THE LOWER ELEVATIONS OF NORTHWEST COLORADO ALONG THE
FOOTHILLS OF THE MOUNTAINS.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 306 PM MST SUN FEB 14 2016
A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS
AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM
IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED
INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS
EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION
THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF
THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND
INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM
GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON.
BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT
BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE
PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS
EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL
LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND
ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH
THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL
PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL
LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70
CORRIDOR...AND ROARING FORK VALLEY.
UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED
WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP
NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW
IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING
SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS
AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE
THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH
ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE
NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE
GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS
AND PULL DOWN EARLY IF NEEDED.
THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS
SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE
SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 306 PM MST SUN FEB 14 2016
BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES
INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN
CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS
MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE
THEIR WARM TREND FOR A NICE START TO THE WORK WEEK.
STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF
LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP
TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW
FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE
EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS
THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS
THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED
WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS
SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE
DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO
EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL
MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET
ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER
PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE
MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM.
AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY
BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS
EASTWARD.
EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS
THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO
REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 958 PM MST SUN FEB 14 2016
A BREAK IN THE SNOW SHOWERS IS OCCURRING AND WILL CONTINUE TO DO
SO THROUGH ABOUT 10 TO 12Z MONDAY MORNING. SNOW SHOWERS WILL IMPACT
HIGH MOUNTAIN AREAS OF WESTERN COLORADO FROM RABBIT EARS PASS
SOUTH TO VAIL PASS BEGINNING AROUND 12Z...BUT WILL BE MAINLY
CENTERED TO THE PARK/GORE/ELKHEAD RANGES. BREEZY CONDITIONS WITH
GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE DAY MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR
COZ004-005-013.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...JOE/TGR
LONG TERM...TGR
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
340 AM EST MON FEB 15 2016
.DISCUSSION...
...SLIGHT CHANCE FOR STRONG STORMS THIS EVENING/OVERNIGHT...
TODAY-TONIGHT...SHORTWAVE TROUGH DIGGING ACROSS THE SOUTHERN
STATES WILL GENERATE A SURFACE LOW VICINITY OF THE LOWER
MISSISSIPPI VALLEY EARLY TODAY...WHICH WILL GRADUALLY DEEPEN WHILE
LIFTING INTO THE SOUTHERN APPALACHIANS TONIGHT. THIS SYSTEM WILL
BE MOVING RATHER QUICKLY SO MOISTURE RETURN AND INSTABILITY WILL
BE LIMITED. STILL...WITH GOOD LARGE SCALE ASCENT...EXPECT HIGH
RAIN CHANCES PRIMARILY DURING THE OVERNIGHT PERIOD.
THE GFS AND HRRR HAVE BEEN SHOWING SOME CONVECTION DEVELOPING LATE
AFTERNOON/EARLY EVENING FROM BOUNDARY INTERACTIONS. HAVE GONE
WITH 30 PERCENT POPS DURING THE TODAY PERIOD FOR THIS POSSIBILITY...
THEN INCLUDED A SLIGHT CHANCE FOR THUNDERSTORMS THROUGH LATE
EVENING AS DEEPENING TROUGH GETS NEARER. DURING THE OVERNIGHT
PERIOD...MOS POPS INCREASE TO 60-90 PERCENT. DID NOT GO QUITE THAT
HIGH AND HAVE SETTLED ON LIKELY POPS (60-70 PERCENT) WITH A
CONTINUED SLIGHT CHANCE FOR STORMS...EXCEPT 50 PERCENT POPS IN THE
SOUTH.
THE MAIN CONCERN WHEN THUNDER IS IN THE FORECAST THIS TIME OF THE
YEAR WILL BE THE THREAT FOR STRONG OR SEVERE STORMS. WITH SURFACE
DEW POINTS RECOVERING ONLY INTO THE LOWER 60S AND THE PRIMARY
SUPPORT FOR DEEP CONVECTION OCCURRING OVERNIGHT...INSTABILITY
WILL BE LIMITED. ADDITIONALLY...LOW LEVEL WIND FIELDS ONLY
INCREASE TO ABOUT 30-35 KNOTS. BUT IT WILL BE QUITE COLD ALOFT
WITH 500 MB TEMPS AROUND MINUS 15 CELSIUS. WILL HAVE TO WATCH FOR
PRE FRONTAL CONVECTION OVER THE GULF SPREADING INLAND AND HOLDING
TOGETHER SOMEWHAT AS SURFACE WINDS STAY BACKED ENOUGH TO SUSTAIN
LOW LEVEL CONVERGENCE. THE GFS SHOWS 0-1KM HELICITY VALUES 100-200
M2S2 OVERNIGHT SO DO NOT WANT TO RULE OUT A SMALL RISK FOR STORM
ORGANIZATION AND SEVERE WEATHER. THE STORM PREDICTION CENTER DOES
HAVE A MARGINAL RISK FOR ALL OF EAST CENTRAL FLORIDA EXCEPT THE
TREASURE COAST.
TUE...BOTH THE ECMWF AND GFS SHOW THE SURFACE FRONT EXITING CENTRAL
FLORIDA LATE AFTERNOON AND OVER SOUTH FLORIDA BY MID EVENING AS THE
PARENT LOW OVER SW PA AND WA LIFTS NORTHEAST TO THE LOWER SAINT
LAWRENCE RIVER VALLEY IN CANADA. PERCEPTIBLE WATER VALUES DROP OFF
FROM AROUND 1 INCH AT 7AM/12Z TUE MORNING TO 0.75 INCHES SOUTHERN AREAS
AND 0.25 INCHES NORTH LAKE COUNTY EARLY AFTERNOON. ANY RAIN CHANCES
LOOK TO BE OVER AND EAST OF THE GULF STREAM. HIGHS MID 70S ORLANDO TO
CAPE CANAVERAL AND NORTH AND THE UPPER 70S SOUTH OF THE ABOVE
MENTIONED LINE.
WED-SUN...THE 500MB TROUGH CLEARS CENTRAL FLORIDA OVERNIGHT WED AND IS
REPLACED BY AN UPPER LEVEL HIGH PRESSURE CENTER THAT WORKS ITS
WAY FROM THE SOUTHWEST U.S. COAST TO EASTERN GULF OF MEXICO SAT.
TIME HEIGHT CROSS SECTIONS SHOW DRY SUBSIDENT AIR MASS FROM TUE
NIGHT TO OVERNIGHT THU/FRI MORNING BEFORE ANY APPRECIABLE MOISTURE
STARTS TO OCCUR. LITTLE OR NO MID AND UPPER LEVEL DYNAMIC SUPPORT
AND THE A DRY ATMOSPHERE LIMITS RAIN POTENTIAL FOR RAIN. WEAK
SURFACE HIGH PRESSURE OVER TEXAS BUILDS EAST ACROSS THE GULF OF
MEXICO WED IS RE ENFORCED BY HIGH PRESSURE BUILDING FROM THE UPPER
MID WEST ACROSS THE SOUTHEAST AND INTO THE ATLANTIC. WEST TO
NORTHWEST WINDS WED BECOME NORTH THU AND EAST FRI AFTERNOON. HIGHS
CLIMO LOW 70S AND LOWS MID UPPER 40S NORTH AND AROUND 50 SOUTHERN
COUNTIES FORT PIERCE SOUTH.
&&
.AVIATION...A MOISTENING SOUTHEAST WIND FLOW WILL PRODUCE
CONSIDERABLE STRATOCUMULUS TODAY WITH CEILINGS MAINLY ABOVE 3500
FEET. THERE WILL BE A CHANCE FOR SHOWERS ESPECIALLY LATE IN THE
DAY WITH LOCAL MVFR. AS A STRONG TROUGH ALOFT APPROACHES
TONIGHT...SHOWERS WILL INCREASE IN COVERAGE AND EXPECT A SLIGHT
CHANCE FOR STORMS SO MVFR CONDITIONS WILL BECOME MORE LIKELY AND
LOCAL IFR WILL BE POSSIBLE.
&&
.MARINE...
TODAY-TONIGHT...POOR TO HAZARDOUS CONDITIONS FOR SMALL CRAFT
OPERATION INDICATED. SOUTHEAST WINDS EARLY THIS MORNING HAVE BEEN
20 KNOTS AND GUSTY OFFSHORE WHILE A WEAK COASTAL TROUGH WAS
KEEPING THE PRESSURE GRADIENT WEAKER NEAR SHORE. THIS TROUGH WILL
BREAK DOWN DURING DAYTIME HEATING AND EXPECT WINDS NEAR 20
KNOTS...AND GUSTY TO 25 KNOTS OVER MOST OF THE WATERS BY LATE
MORNING/EARLY AFTERNOON. WINDS WILL VEER MORE TO THE SOUTH TONIGHT
WHILE STAYING AROUND 20 KNOTS. NO CHANGE TO THE PREVIOUS
HEADLINES.
TUE...SOUTHWEST WINDS TO 20 KNOTS AHEAD AND JUST AFTER FRONTAL
PASSAGE. WINDS SHIFT TO THE WEST IN THE AFTERNOON THEN NORTHWEST
TUE NIGHT. SEAS 6 TO 8 FEET WELL OFFSHORE EARLY TUE MORNING
SUBSIDE TO 4 TO 6 FEET LATE TUE AFTERNOON.
WED-FRI...10 TO 20 KNOT WINDS FIRST SHIFT TO THE NORTH WED THEN
NORTHEAST AND EAST THU AND FRI AS THE HIGH PRESSURE MOVES EAST INTO NEW
ENGLAND. MAY NEED SMALL CRAFT ADVISORY FOR SEAS IN THE GULF STREAM
OVERNIGHT WED AS SEAS MAY REACH 7 FEET OR MORE DUE TO THE NORTH WIND.
SEAS DROP OFF TO 6 FEET OR LESS THU AND FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 61 76 50 / 30 70 30 10
MCO 78 62 77 51 / 30 70 20 10
MLB 75 64 78 53 / 30 60 30 10
VRB 77 64 79 53 / 30 60 30 10
LEE 77 61 75 49 / 30 70 20 10
SFB 77 62 77 49 / 30 70 20 10
ORL 77 62 76 52 / 30 70 20 10
FPR 77 64 79 51 / 30 50 30 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR SEBASTIAN INLET
TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR FLAGLER BEACH
TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM...LASCODY
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
338 AM EST MON FEB 15 2016
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFYING UPPER
LEVEL PATTERN OVER THE CONUS EARLY THIS MORNING. TROUGHING THAT
BROUGHT THE EXTREME COLD TO THE NORTHEASTERN STATES OVER THE PAST
WEEKEND IS NOW LIFTING OUT OVER FAR EASTERN CANADA WITH HEIGHT
RISING IN ITS WAKE OVER THESE FROZEN STATES. ELSEWHERE THE
NORTHERN STREAM FLOW IS DOMINATING THE WEATHER ACROSS THE NATION.
THIS FLOW ARRIVES OVER NORTH AMERICA WITHIN A STRONG JET CORE
MOVING ASHORE OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA COASTS
BEFORE DIVING SOUTHEAST THROUGH THE CONTINENTAL DIVIDE INTO AN
AMPLIFYING CENTRAL CONUS TROUGH. THIS TROUGH WILL CONTINUE TO DIG
SOUTH AND EASTWARD THROUGH TODAY AND BRING SHOWERS CHANCES BACK
TO OUR FORECAST BY LATER TODAY INTO TONIGHT. WHILE THE MAIN SYSTEM
AND COLD FRONT DUE TO ARRIVE TONIGHT/TUESDAY MORNING WILL BE MORE
ASSOCIATED WITH THE ENERGY CURRENTLY DIVING SOUTH THROUGH THE
CENTRAL/SOUTHERN PLAINS...A SEPARATE FRONT-RUNNING PIECE OF
SHORTWAVE ENERGY IS CURRENTLY EJECTING OFF THE TEXAS/NORTHERN
MEXICO COAST OVER THE WESTERN GULF OF MEXICO. THIS ENERGY WILL BE
FIRST TO APPROACH THE FLORIDA PENINSULA LATER TODAY...BRINING AN
INITIAL REGION OF UPLIFT AND SHOWER POTENTIAL BY LATER
AFTERNOON...AND ESPECIALLY BY THE EARLY EVENING HOURS. MORE
DETAILS ON THIS WHOLE PROCESS IN THE SHORT TERM DISCUSSION BELOW.
WV IMAGERY SHOWS INITIAL UPPER LEVEL MOISTURE OVERSPREADING OUR
SKIES...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE
FLORIDA PENINSULA. BELOW THIS LEVEL...THE MID PORTIONS OF THE TROP
ARE STILL RATHER DRY...AS SEEN ON THE 15/00Z KTBW SOUNDING PROFILE.
CROSS SECTIONAL ANALYSIS FROM BOTH THE GFS/ECMWF SUGGEST WHILE
MODEST MOISTENING WILL BEGIN DURING THE NEXT 6-10 HOURS...OVERALL
THESE MID-LEVELS WILL REMAIN FAIRLY DRY THROUGH MUCH OF THE
MORNING...BUT THEN RAPIDLY BEGIN TO MOISTEN FROM THE TOP DOWN AS WE
REACH THE MIDDAY HOURS AND INTO THE AFTERNOON.
AT THE SURFACE...LARGE SCALE HIGH PRESSURE IS MIGRATING OFF THE
EASTERN SEABOARD TO OUR NORTH THIS MORNING. THE SYNOPTIC GRADIENT
FLOW AROUND THIS RIDGE IS PROVIDING A GENERAL EASTERLY FLOW TO OUR
REGION. JUST NOW BEGINNING TO SEE THE FIRST SIGNS OF A SURFACE
REFLECTION LOW NEAR THE ARKLATEX REGION UNDERNEATH THE AMPLIFYING
UPPER TROUGH. THIS LOW WILL ORGANIZE THROUGH THE DAY AS IT MIGRATES
EASTWARD THROUGH NORTHERN LA/AL/AL. AS THE LOW DEEPENS...WE SHOULD
SEE OUR GRADIENT FLOW VEER MORE TO THE SOUTHEAST AND EVENTUALLY
MORE SOUTHERLY.
TEMPERATURES ARE CERTAINLY WARMER THIS MORNING THAN THEY WERE EARLY
SUNDAY...DUE MAINLY TO AN IMPRESSIVE DEWPOINT RECOVERY WITHIN THE
PAST 24 HOURS. CERTAINLY NO THREAT OF FROST OR FREEZING TEMPERATURES
WITHIN OUR FORECAST AREA THIS MORNING. TO BE HONEST...DO NOT SEE A
PATTERN THAT WOULD SUGGEST A THREAT FOR EITHER THROUGH THE DURATION
OF THE FORECAST PERIOD.
&&
.SHORT TERM (TODAY THROUGH TUESDAY)... KIND OF A COMPLEX/MESSY
FORECAST FOR THE FIRST 24 HOURS OF THE SHORT TERM...AS AN ILL-
DEFINED AND MUTLI-STAGE SYSTEM PASSES OVER THE REGION. THE
TOUGHEST CALL WILL BE THE POTENTIAL FOR BREAKS TO EXIST IN THE
BANDS OF SHOWERS THAT ARE FORECAST TO CROSS LATER TODAY AND
TONIGHT. FAIRLY CONFIDENT THAT THESE BANDS WILL CROSS THE FORECAST
AREA...BUT SOME SPOTS MAY JUST END UP BEING IN SOMEWHAT DRIER
SWATHS (COMPARED TO OTHERS) DUE MAINLY TO THE DECREASING OVERALL
STRUCTURE OF THE OMEGA FIELDS...AND WEAKENING LOW LEVEL FOCUS
ALONG THE FRONT AS WE HEAD INTO THE OVERNIGHT. WILL TRY TO PUT IT
ALL TOGETHER INTO A COHESIVE FORECAST.
FOR THE FIRST HALF OF TODAY...THE FORECAST WILL BE DRY WITH A
GENERAL INCREASE IN CLOUDS. THEREAFTER...AS MENTIONED ABOVE...WILL
SEE AN INCREASE IN LARGE SCALE LIFT OVER THE REGION...AND A SLOW
TOP DOWN MOISTENING OF THE TROP COLUMN. INITIAL SHORTWAVE ENERGY
EJECTS THROUGH THE MIDDLE GULF LATER THIS MORNING AND INTO THE
EASTERN GULF BY LATE THIS AFTERNOON. DEEP LAYER MODEST ISENTROPIC
UPGLIDE/WAA REGIME WILL BE UNDERWAY MOST OF THE DAY OVER THE
EASTERN GULF AHEAD OF THE SHORTWAVE ALONG THE 295-315K SURFACES.
WITHIN THE LAYER FIELDS WE SEE INITIAL SATURATION DUE TO THIS
UPGLIDE OCCUR WITHIN THE MID/UPPER LEVELS AND THEN WORK DOWN AS
THE FIELDS EXPAND OVER THE FL PENINSULA. IT WILL BE RACE TO SEE IF
THE COLUMN MOISTURE BECOMES SUFFICIENT BEFORE...THE SYNOPTIC
QVECTOR CONVERGENCE AHEAD OF THE SHORTWAVE ARRIVES TO FURTHER
ENHANCE THE OVERALL LIFT. THE PHASING OF THESE FACTORS WILL
DETERMINE THE EXTENT OF THE SHOWER ACTIVITY DURING THE LATE
AFTERNOON/EVENING HOURS. WILL HIGHLIGHT CHANCE POPS ESSENTIALLY
REGION-WIDE AFTER 21Z...BUT IT IS VERY DIFFICULT TO SAY IF THE
COVERAGE WILL BE ENOUGH TO CAUSE SIGNIFICANT IMPACTS FOR OUTDOOR
ACTIVITIES.
THE SECOND AND MAIN SHORTWAVE ENERGY DRIVING THE SURFACE LOW AND
TRAILING COLD FRONT WILL THEN APPROACH AND PASS OVER THE REGION
DURING THE OVERNIGHT HOURS. THIS IS WHERE THINGS BECOME COMPLEX FOR
DIFFERENT REASONS. DURING THE EVENING HOURS WE ARE LIKELY TO SEE A
RATHER SOLID AND HEALTHY BAND OF CONVECTION OFF TO OUR WEST AND
NORTHWEST AHEAD OF THE COLD FRONT AS THE SYNOPTIC FORCING...DEEP
LAYER SHEAR...AND SURFACE CONVERGENCE ARE ALL STRONG. HOWEVER...AS
THE SHORTWAVE GETS CLOSER...GUIDANCE IS IN GOOD AGREEMENT THAT IT
WILL TAKE ON AN INCREASINGLY NEGATIVE TILT. THE NEGATIVE TILT WILL
GUIDE THE SURFACE LOW TO INCREASE LATITUDE WITH TIME. SO...AS THE
FRONT APPROACHES...THE LOW WILL BE LIFTING FURTHER NORTHWARD...WITH
LOW LEVEL WIND FIELDS CONTINUING TO VEER. THIS VEERING WILL ACT TO
DECREASE THE FOCUS ALONG THE FRONT. THIS FACTOR ALONG WITH BEST
SYNOPTIC FORCING STAYING JUST NORTH MAY BEGIN A DECREASING TREND
IN CONVECTIVE STRUCTURE ALONG THE SOUTHERN END OF THE FRONT MOVING
INTO OUR AREA. FOR STORMS THAT DO ARRIVE ALONG OUR COASTS...THERE
ARE SOME FACTORS IN PLACE TO SUGGEST A FEW MIGHT BE STRONG. SPC
HAS OUTLOOKED OUR CENTRAL/NORTHERN ZONES IN A MARGINAL RISK FOR
STRONG STORMS. CERTAINLY LOOKING AT THE GUIDANCE...IT WOULD
SUGGEST BEST CHANCES FOR STRONG UPDRAFTS STAY JUST NORTH...BUT ITS
A CLOSE CALL. DECENT MID-LEVEL LAPSE RATES AROUND 7C/KM REACH
PARTS OF THE NATURE COAST...ALONG WITH THE VERY SOUTHERN END OF
THE 40+ KNOT LOW LEVEL JET. THE WIND FIELDS AND DEEP LAYER SHEAR
WOULD NOT BE CONSIDERED IMPRESSIVE...BUT THEY ARE SUFFICIENT TO
SUSTAIN ORGANIZED UPDRAFTS...AND RADAR TRENDS OF INDIVIDUAL STORMS
WILL NEED TO BE MONITORED OVERNIGHT REGARDLESS OF OVERALL
CONVECTIVE LINE ORGANIZATION.
SECOND COMPLICATING FACTOR: DO WE SEE A CONVECTIVE BLOWUP OVER THE
BAROCLINIC WARMER WATERS OF THE SOUTHERN LOOP CURRENT TO OUR
SOUTHWEST BEFORE THE FRONT GETS TO OUR REGION? THIS SOMETIMES
OCCURS WITH SHORTWAVES SIMILAR TO THIS ONE. WHEN THIS OCCURS...TWO
THINGS HAPPEN. THIS CONVECTION GENERALLY HEADS EAST QUICKLY TOWARD
SOUTHERN FLORIDA/THE KEYS...WHILE CUTTING OFF INFLOW TO CONVECTION
FURTHER NORTH...AND ALSO SENDING CONSIDERABLE LATENT HEATING INTO
THE MID-LEVELS STREAMING OVER OUR REGION. BOTH OF THESE IMPACTS
ARE NEGATIVES TO HEALTHY CONVECTION. IN THIS CASE...WE COULD SEE A
SPLIT WHERE BETTER CONVECTION PASSES TO OUR SOUTH...AND PASSES TO
OUR NORTH. SEVERAL OF THE HIRES CONVECTION ALLOWING GUIDANCE
MEMBERS ARE SHOWING THIS SCENARIO...SO IT CAN NOT BE IGNORED.
OK...YOU GET THE POINT. NOT AN EASY FORECAST. NO FORECAST IS EVER
PERFECT...AND THIS IS SIMPLY A SITUATION THAT WILL NEED TO BE
MONITORED CLOSELY THROUGH THE DAY AND ADJUSTED AS NECESSARY.
LUCKILY AFTER TUESDAY MORNING...THE PATTERN QUIETS DOWN AND
BECOMES MUCH MORE STRAIGHT FORWARD FOR A FEW DAYS.
SPEAKING OF TUESDAY...SHOWERS END DURING THE MORNING AS THE COLD
FRONT AND SUPPORTING SHORTWAVE ENERGY EXIT THE REGION. SURFACE
RIDGING QUICKLY BUILDS IN FROM THE WEST AND NORTHWEST FOR THE
SECOND HALF OF THE DAY. THE AIRMASS BEHIND THIS FRONT IS ONLY
SLIGHTLY COOLER AND DRIER...AND ITS PASSAGE WILL NOT HAVE THE
POST-IMPACT THAT HAS BEEN SEEN RECENTLY WITH PREVIOUS FRONTS. IN
FACT...TEMPERATURES TUESDAY AFTERNOON ARE LIKELY TO STILL REACH
THE 70S OVER THE INLAND ZONES. TEMPS WILL BE AT LEAST SEVERAL
DEGREES COOLER NEAR THE COAST WITH A MODERATE WESTERLY ONSHORE
FLOW OFF THE SHELF WATERS.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
AN UPPER LEVEL TROUGH OVER AND ALONG THE EASTERN SEABOARD ROTATES OUT
OVER THE ATLANTIC AS A BUILDING RIDGE ALOFT THE WESTERN STATES SLIDES
EAST ACROSS THE CONUS THROUGH THE REST OF THE WEEK THEN FLATTENS ACROSS
THE SOUTHEAST QUARTER OF THE NATION FOR THE WEEKEND. SURFACE LOW PRESSURE
IN THE MID-ATLANTIC STATES EXITS UP INTO THE SAINT LAWRENCE VALLEY BY
THE END OF WED...WITH A WEAK TROUGH SWEEPING ACROSS THE SOUTHEASTERN
STATES. A SPRAWLING SURFACE RIDGE FROM MANITOBA TO TX STRENGTHENS AS IT
TRACKS EASTWARD...STRETCHING FROM THE CANADIAN MARITIMES TO THE
GULF OF MEXICO BY FRI. DURING THE WEEKEND THIS RIDGE PIVOTS OVER
THE ATLANTIC WHILE RIDGING BACK ACROSS THE SOUTHEAST U.S. AND MUCH
OF THE GULF.
THE WEAK TROUGH MOVES BY TO THE NORTH ON WED WITH LITTLE IMPACT TO THE
AREA. THEN THE HIGH PRESSURE IN THE WEST TAKES CONTROL AS IT MOVES EAST
THEN SOUTHEAST...WITH CLEAR/MOSTLY CLEAR SKIES AND A DRY STABLE AIR MASS.
TEMPERATURES ON THE COOL SIDE...INITIALLY...BUT CLOSE TO SEASONAL. THEN
AS THE SURFACE HIGH CENTER MOVES OUT OVER THE ATLANTIC SAT AND SUN THE
LOW LEVEL FLOW BECOMES MORE EASTERLY AND WARMER WITH TEMPERATURES RISING
TO NEAR OR JUST ABOVE SEASONAL. THIS FLOW WILL ALSO PROVIDE AN INCREASE
IN MOISTURE WITH A FEW MORE CLOUDS.
&&
.AVIATION...
NO SIGNIFICANT RESTRICTIONS ARE ANTICIPATED THROUGH THE DAYLIGHT
HOURS...ALTHOUGH A FEW SHOWERS ARE EXPECTED TO BEGIN OVERSPREADING
THE TERMINALS AFTER MID-AFTERNOON. HIGHER POTENTIAL FOR SHOWERS
AND A FEW STORMS ARE IN THE FORECAST TONIGHT...WITH GUIDANCE
SUGGESTING WIDESPREAD IFR/MVFR CIGS DEVELOPING AFTER 03Z. SOME
POTENTIAL FOR SEA FOG DEVELOPMENT AS WELL LATE AT NIGHT THAT MAY
IMPACT KTPA/KPIE/KSRQ. CONFIDENCE IN SEA FOG IS NOT HIGH ENOUGH TO
INCLUDE IN CURRENT TAFS...BUT WILL NEED TO BE MONITORED CLOSELY
WITH FUTURE FORECASTS.
&&
.MARINE...
HIGH PRESSURE TO OUR NORTH MIGRATES OFF THE EASTERN SEABOARD TODAY
AS A COLD FRONT ORGANIZES ACROSS THE CENTRAL GULF OF MEXICO AND
APPROACHES THE FORECAST WATERS. SOUTHEASTERLY WINDS EXPECTED FOR
TODAY WITH A TURN TO THE SOUTH OVERNIGHT AHEAD OF THE FRONT.
SHOWERS AND STORMS ARE EXPECTED TO INCREASE IN COVERAGE LATER THIS
AFTERNOON INTO THE OVERNIGHT HOURS. THE COLD FRONT CROSSES THE
REGION LATE TONIGHT INTO TUESDAY MORNING WITH A WIND SHIFT TO THE
WEST AND NORTHWEST IN ITS WAKE. HIGH PRESSURE THEN RIDGES DOWN
FROM THE NORTH INTO THE EASTERN GULF FOR THE DURATION OF THE
FORECAST PERIOD.
WATCHING THE POTENTIAL FOR PATCHY SEA FOG DEVELOPMENT TONIGHT
INTO TUESDAY MORNING...MAINLY TO THE NORTH OF ENGLEWOOD.
CONDITIONS ARE MARGINAL FOR FOG DEVELOPMENT...AND WILL NEED TO BE
MONITORED CLOSELY WITH FUTURE FORECASTS.
&&
.FIRE WEATHER...
HIGH PRESSURE WELL TO OUR NORTH MOVES OFF THE EASTERN SEABOARD
TODAY...WITH WINDS COMING AROUND FROM EASTERLY TO SOUTHEASTERLY.
LOW LEVEL MOISTURE CONTINUES TO INCREASE KEEPING RELATIVE HUMIDITY
VALUES WELL ABOVE CRITICAL LEVELS. CONDITIONS WILL HOWEVER CREATE
HIGH DISPERSION INDICES OVER PORTIONS OF THE REGION THIS
AFTERNOON. A COLD FRONT WILL CROSS THE AREA LATER TONIGHT INTO
TUESDAY MORNING WITH A ROUND OR TWO OF SHOWERS AND THUNDERSTORMS.
THESE SHOWERS WILL END BY TUESDAY AFTERNOON...AND BE FOLLOWED BY A
PROLONGED PERIOD OF DRY WEATHER THROUGH THE REMAINDER OF THE WEEK.
THE AIRMASS BEHIND THIS FRONT IS ONLY SLIGHTLY COOLER AND
DRIER...AND THEREFORE...NO CRITICAL LEVELS OF RELATIVE HUMIDITY OR
RED FLAG CONDITIONS ARE ANTICIPATED THROUGH THE NEXT SEVERAL DAYS.
FOG POTENTIAL...
NO FOG IS EXPECTED THIS MORNING. THERE IS SOME POTENTIAL FOR
PATCHY SEA FOG DEVELOPMENT LATE TONIGHT INTO TUESDAY MORNING.
IF SEA FOG DEVELOPS...THEN FORECAST SOUTHWEST TO WEST FLOW COULD
PUSH THE REDUCED VISIBILITY ONSHORE AT THE IMMEDIATE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 63 71 54 / 30 60 20 10
FMY 77 64 77 57 / 30 50 30 10
GIF 77 62 76 52 / 30 60 30 0
SRQ 72 61 69 54 / 30 60 20 10
BKV 77 61 73 45 / 30 60 20 10
SPG 73 62 70 56 / 30 60 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH TUESDAY EVENING FOR
COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL
SARASOTA.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
311 AM EST MON FEB 15 2016
.SYNOPSIS...
A WARM FRONT WILL EXTEND THROUGH SOUTHERN GEORGIA AND ALONG THE
SOUTH CAROLINA COAST TODAY. ASSOCIATED LOW PRESSURE MOVING INTO
THE LOWER MISSISSIPPI RIVER VALLEY TODAY WILL BE NEAR THE FORECAST
AREA TONIGHT. DRYING WILL OCCUR TUESDAY AS THE LOW LIFTS NORTHWARD
AND FARTHER AWAY FROM THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...COLD HIGH PRESSURE WILL BE WEDGED INTO THE FORECAST AREA
WITH A WARM FRONT NEAR THE COAST AND IN SOUTHERN GEORGIA. THE
FRONT WILL LIFT NORTHWARD SLOWLY. THE NAM SURFACE-BASED LI
PATTERN MAINTAINS THE WEDGE PATTERN HERE THROUGH TODAY. STRONG
ISENTROPIC LIFT SUPPORTS PRECIPITATION BUT IT SHOULD REMAIN
LIMITED BECAUSE OF SHALLOW MOISTURE AND LITTLE UPPER-LEVEL LIFT.
THE NAM...GFS...ECMWF...AND ALL SREF MEMBERS INDICATE LITTLE
PRECIPITATION...0.01 OF AN INCH THIS MORNING...AND 0.01 TO 0.1 OF
AN INCH THIS AFTERNOON. THE HRRR HAS A FEW PATCHES OF LIGHT
PRECIPITATIONS THIS MORNING WITH A LITTLE MORE COVERAGE THIS
AFTERNOON. SURFACE WET BULB TEMPERATURES AND MODEL FORECAST
SOUNDINGS SUPPORT A PREDOMINATE PRECIPITATION TYPE OF FREEZING
RAIN OR FREEZING DRIZZLE BECOMING ALL LIQUID FROM SOUTH TO NORTH.
THE TIMING SUPPORTS MORE OF A THREAT IN THE NORTH AND WE HAVE
POSTED A FREEZING RAIN ADVISORY IN THE NORTH SECTION. THE THREAT
OF FREEZING RAIN WILL LIKELY CONTINUE IN THE EXTREME NORTH PART
UNTIL ABOUT 100 PM BASED ON THE SREF MEAN TEMPERATURE. IT IS
POSSIBLE THE COLDER AIR WILL REMAIN IN PLACE LONGER AS INDICATED
BY THE IN-HOUSE WEDGE SCHEME. HOWEVER...IT IS BASED ON THE NAM
WHICH AS HAD A COLD BIAS LATELY. GIVEN THE VERY LOW QPF WE EXPECT
JUST TRACE ICE ACCUMULATIONS BUT IT TAKES LITTLE ICE TO CAUSE
ISSUES. THE THREAT SHOULD BE MAINLY ON ELEVATED SURFACES SUCH AS
BRIDGES AND OVERPASSES.
TONIGHT...TEMPERATURES SHOULD BE ABOVE FREEZING THROUGHOUT THE
AREA AS WARMING OCCURS AHEAD OF APPROACHING LOW PRESSURE. THE
NOCTURNAL LOW WILL OCCUR AT SUNSET. CONVERGENCE ASSOCIATED WITH
THE LOW...A STRONG H85 JET AND H5 SHORTWAVE TROUGH WILL RESULT IN
SHOWERS TONIGHT. THE GUIDANCE WAS CONSISTENT WITH CATEGORICAL POPS.
THE NAM...GFS...ECMWF...AND SREF MEAN SUPPORT RAINFALL OF 0.5 TO
1 INCH. THE MODELS DEPICT A NEGATIVE TILT UPPER TROUGH. STRONG
UPPER DIVERGENCE AND THE LOW-LEVEL JET MAY RESULT IN ENOUGH
INSTABILITY FOR A FEW ELEVATED THUNDERSTORMS. THE NAM INDICATES
CROSS TOTALS IN THE MID 20S. DESPITE THE STRONG SHEAR THE THREAT
OF SEVERE THUNDERSTORMS SHOULD REMAIN LOW BECAUSE OF A LACK OF
SURFACE-BASED INSTABILITY AS INDICATED BY THE NAM LI FORECAST.
IT WILL LIKELY BECOME BREEZY TONIGHT WITH INCREASED MIXING NEAR
THE COLD FRONT. WE WILL LIKELY NEED A LAKE WIND ADVISORY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
DRYING SHOULD OCCUR TUESDAY BEHIND THE COLD FRONT AND MAIN MID-
LEVEL SHORTWAVE TROUGH. MIXING AND THE PRESSURE GRADIENT
ASSOCIATED WITH LOW PRESSURE LIFTING NORTH OF THE AREA SHOULD
RESULT IN BREEZY CONDITIONS. A LAKE WIND ADVISORY WILL LIKELY BE
NEEDED.
THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT
ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF
THE FORECAST AREA TUESDAY NIGHT. A PRESSURE RIDGE WEST OF THE
AREA SHOULD MAINTAIN DRY CONDITIONS WEDNESDAY.
USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST TUESDAY
THROUGH WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY DRY RIDGING DOMINATING THROUGH THE
MEDIUM-RANGE PERIOD EXCEPT MOISTURE DOES APPEAR TO INCREASE SATURDAY
OR SUNDAY ASSOCIATED A DEVELOPING WARM FRONT. THE GFS...ECMWF...
AND EKD MOS HAVE POPS LESS THAN 10 PERCENT THROUGH FRIDAY...AND 5
TO 20 PERCENT SATURDAY AND SUNDAY. THE MOS HAS NEAR OR ABOVE
NORMAL TEMPERATURES DURING THE PERIOD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF THE
TAF PERIOD.
MVFR CIGS ACROSS THE TAF SITES EARLY THIS MORNING WITH EASTERLY
WINDS 4 TO 8 KNOTS. THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH
CIGS LOWERING TO IFR 12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT
OR ABOVE 1000 FEET. HOWEVER...ALL MODELS INDICATE IFR/LIFR
CONDITIONS DEVELOPING BY 16/00Z.
GIVEN LATEST NAM MODEL GUIDANCE AND CAE VWP...WILL MENTION LLWS AT
ALL TAF SITES UNTIL AROUND 15Z WITH 30 KTS AOB 2000 FT POSSIBLE. NO
FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS.
MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA EARLY
THIS MORNING AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE
OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST
BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE
MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF
ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE
TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY
NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM
CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT
INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
SCZ015-016.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
314 AM CST MON FEB 15 2016
.SHORT TERM...(Today)
ISSUED AT 314 AM CST MON FEB 15 2016
08z/2am radar imagery continues to indicate patchy freezing drizzle
across central Illinois: however, the areal coverage and intensity
has decreased markedly from earlier in the evening. As light
southerly winds flow over the cold/snow-covered ground, expect fog
and perhaps some drizzle to persist through the morning. Current
visibilities are mostly in the 2-5 mile range, but HRRR suggests the
potential for even lower visbys as WAA continues and low overcast
lifts. Have seen a few reports of 1/4 mile visbys upstream across
central Missouri where clouds have temporarily cleared and expect
the fog to thicken/spread northeastward into central Illinois over
the next few hours. Will need to carefully monitor trends, as a
Dense Fog Advisory could be needed if HRRR verifies. For now, will
just mention areas of fog in the forecast through midday. A weak
short-wave trough evident on latest water vapor imagery over eastern
Nebraska will pass to the W/SW of the area today. A small area of
light snow associated with this feature over southwest Iowa will
spread across northern Missouri and may approach the far SW CWA
toward midday: however, all high-res models show the precip
dissipating before arriving. Have therefore gone with a dry
forecast. Despite continued southerly flow, fog and extensive cloud
cover will keep afternoon high temperatures in the middle to upper
30s.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 314 AM CST MON FEB 15 2016
The next fast-moving storm system embedded within the prevailing
northwesterly flow aloft will arrive late tonight into Tuesday,
bringing another period of wintry precip to central Illinois. 00z
Feb 15 models have all trended south with the track of this system,
with the NAM being the furthest north and the GEM the furthest
south. Have rejected these two solutions in favor of the middle
of the road GFS, which takes the 500mb vort max from northern
Missouri 12z Tue to far southern Illinois by 18z Tue. Given this
particular track, the heaviest precip will be focused across the
central/southern CWA. Have therefore reduced PoPs into the
chance category along/north of I-74...while maintaining likely
further south across the remainder of the area. Another
consequence of a further south track is a slightly colder thermal
profile. GFS forecast soundings are generally cold enough for
snow initially as the max temp in the elevated warm layer only
reaches about 1C. As a result, am expecting snow Tuesday
morning, gradually transitioning to a rain/snow mix by afternoon
as surface temps rise into the middle to upper 30s. Due to the
southward track shift, relatively light precip, and marginal
temps...snow accumulations are expected to remain minor. Will
see a band of around 1 inch along/southwest of a Canton...to
Decatur...to Marshall line...with less than one half inch north of
I-74.
Another weak short-wave will pass through the region on Wednesday:
however, this feature will be moisture-starved and will produce
little more than some cloud cover. Once this wave exits, upper
heights will begin to rise in earnest in response to a major
system coming onshore along the Pacific Coast. Downstream
ridging across the central and eastern CONUS will allow a
pronounced warming trend to occur by the end of the week. Models
have been consistently advertising temps reaching the upper 40s
and lower 50s by Thursday, then climbing into the upper 50s and
lower 60s on Friday. A weak cold front is still progged to pass
through Illinois on Friday, but with only limited moisture to work
with, will only mention slight chance for showers with FROPA.
After that, temps cool a bit over the weekend, but remain above
normal in the 50s for both Saturday and Sunday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1140 PM CST SUN FEB 14 2016
Based on radar trends looks like most of pcpn has moved east of
PIA/SPI/BMI, but may still be around DEC and CMI for 2-3 hours, so
will have VCSH at those sites. Pcpn type will likely be fzdz, but
radar returns are diminishing. IFR cigs will also continue
overnight, through the morning and into the afternoon hours.
During late afternoon and into the evening hours, looks like cigs
could rise to above 1kft and possibly become broken as well. Some
uncertainty in what will happen later as models differ on clouds
and vis due to high pressure moving in. Winds will be south-
southeast through the overnight hours, then become southwest
during the morning hours and continue into the afternoon. As high
pressure moves into the area, winds will become light and
variable.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
255 AM CST MON FEB 15 2016
.SHORT TERM...(Today through Wednesday)
Issued at 255 AM CST MON FEB 15 2016
Scattered light showers continue to stream northeast just clipping
southeastern Todd county Kentucky, but based on the KCKV and KBWG
METARs this area should be just above freezing. Will therefore
let the Winter Weather Advisory expire as scheduled at 3 AM.
Elsewhere across the forecast area, most observation sites have
visibilities between 1 and 3 miles with light fog, and a few
patches of very light freezing drizzle. Weak, drizzly echoes on
radar at Midnight have mostly dried up, so doubt there will be
much, if any, additional icing this morning. However, will re-
issue an SPS mainly to highlight slick driving conditions through
the morning commute.
The 00Z WRF and most recent HRRR runs keep the shower activity
along the TN border through the morning, and then lift it back up
over more of west Kentucky this afternoon before pushing east of
the area early this evening. Given this timing, temperatures
should be above freezing, so there should be no wintry concerns
after the sun gets sufficiently high in the sky this morning.
The 00Z models bring a compact, intense upper low into the base of
the upper trough over the region on Tuesday. The 00Z consensus
keeps any QPF northwest of the area through daybreak, but we will
have to watch for the potential for either freezing rain or snow
with the onset of precipitation in the morning. Model soundings
across the northeast show a warm layer only near the surface, so
it is conceivable that we will have to monitor for snow through
the day as this system passes. Temperatures should be above
freezing, so accumulations will be hard to come by even if the
snow reaches the ground. This system should exit to the east at or
shortly after 00Z Wednesday.
Yet another upper-level disturbance will dive southeast into our
region for Wednesday, as we continue to be heavily influenced by
cyclonic flow aloft. The models are not generating any
precipitation with this activity, but it should keep most of the
area rather cloudy.
.LONG TERM...(Wednesday Night through Sunday)
Issued at 255 AM CST MON FEB 15 2016
By Wednesday into Thursday, we will finally be seeing a shift in the
upper level pattern, as an upper level ridge builds overhead. As
this occurs, we will see quiet weather along with a decent warmup,
that has been advertised for quite a while now. Warm air advection
will begin in earnest Wednesday night and the entire area will see
850mb temps back above zero by late Thursday morning or afternoon.
We should see highs on Thursday well into the 50s per the latest
guidance, 2m temps and soundings. We should see 60s by Friday with
our far western counties in SEMO maybe touching or getting close to
70 degrees. In fact, even warmer weather will only be a state away,
as newest guidance indicating highs around 80 in northeast Oklahoma.
Hard to imagine when you`re currently only sitting at 31 degrees.
Meanwhile, in the northern Plains, an upper level shortwave will be
moving eastward into the Great Lakes Thursday night into Friday. As
this occurs, a weak front at the surface will be moving into our
area. Moisture still appears to be rather scant but the GFS still
tries to eek out some QPF. Whatever does fall, if anything, will be
light. But since POPS have already been taken out, will continue
with that idea and leave it dry, but will have to keep watching, as
the GFS ensembles continue to indicate a few hundredths of QPF with
the FROPA.
The front dives south but only makes into the Gulf Coast State
before stalling out. Models indicate that the front will lift back
north toward the area as early as Saturday night. However, Saturday
should be a dry day with temperatures remaining in the 60s. Another
weak frontal boundary will develop to our west and will move through
on Sunday, which means we will continue with the chance for rain.
The front should be exiting the area sometime on Sunday night. Could
even see some isolated thunderstorms on Saturday night into Sunday
as some of the parameters are hinting at it.
&&
.AVIATION...
Issued at 1154 PM CST SUN FEB 14 2016
Main concerns overnight are patchy freezing drizzle and fog.
Maintained a mention of freezing drizzle at KPAH and KOWB through
08-09Z, with updates if needed through the rest of the night. IFR
and LIFR ceilings and visibilities are also expected through much
of Monday morning. Patchy dense fog is also possible, especially
at KCGI and KPAH. Improvement in flight conditions will be very
gradual through the day. Low pressure moving across the southern
states will bring another chance of rain to portions of western
Kentucky on Monday, but most of this rain should remain just south
of the forecast terminals. Light and variable winds will prevail.
&&
.PAH Watches/Warnings/Advisories...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...RJP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
345 AM CST MON FEB 15 2016
.SHORT TERM...
THE NEXT 18 HOURS WILL SEE THE MOST ACTIVE WEATHER EXPECTED FOR
THE REMAINDER OF THE ENTIRE WEEK. A STRONG UPPER LEVEL TROUGH IS
CURRENTLY DIGGING INTO THE SOUTHERN PLAINS AND TEXAS. THIS TROUGH
WILL SLIDE THROUGH THE LOWER MISSISSIPPI VALLEY TODAY AND SHOULD
BE WELL EAST OF THE AREA BY LATE THIS EVENING AND TONIGHT. A
INCREASINGLY WARM AND BUOYANT AIRMASS HAS ADVECTED INTO THE AREA
TONIGHT...WITH TEMPERATURES ACTUALLY WARMING IN MANY SPOTS. THIS
WARM AND BUOYANT AIRMASS WILL INTERACT WITH THE RAPIDLY INCREASING
OMEGA AND RESULTANT LIFT OVERSPREADING THE REGION TO PRODUCE
SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY.
AN INITIAL BAND OF CONVECTION THAT IS CURRENTLY FORMING OVER THE
NORTHWEST PARTS OF THE CWA IS ASSOCIATED WITH A HIGHLY DIFLUENT
FLOW REGIME ALOFT AND A FAVORABLE JET DYNAMICS ASSOCIATED WITH A
100+ KNOT JET STREAK CURRENTLY SLIDING ACROSS THE GULF SOUTH. THIS
BAND OF CONVECTION WILL CONTINUE TO MOVE ACROSS THE NORTHERN HALF
OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED. A FEW OF THE
STORMS COULD BE STRONG...BUT CONDITIONS DO NOT QUITE LOOK PRIMED
FOR SEVERE CONVECTION THROUGH AT LEAST MID-MORNING AS CAPE WILL
BE SOMEWHAT LIMITED.
HEADING INTO THE LATE MORNING AND AFTERNOON HOURS...ANOTHER BAND
OF CONVECTION SHOULD PUSH THROUGH THE FORECAST AREA. THIS BAND OF
CONVECTION SHOULD FORM ALONG AND JUST AHEAD OF A DRY LINE WHICH IS
CURRENTLY FORMING OVER CENTRAL TEXAS. THE DRY LINE SHOULD QUICKLY
RACE TO THE EAST AT AROUND THE SAME SPEED AS THE PARENT UPPER
LEVEL TROUGH AXIS...AND SHOULD BE MOVING INTO THE ATCHAFALAYA
BASIN SOMETIME AROUND NOON BASED ON THE LATEST HRRR GUIDANCE. IT
LOOKS LIKE THE STRONGEST FORCING AND GREATEST POTENTIAL FOR
CONVECTIVE DEVELOPMENT WILL GENERALLY BE ALONG AND NORTH OF THE
I-10 CORRIDOR...AND HAVE THE HIGHEST POPS IN THIS AREA. DYNAMIC
FORCING SHOULD BE SLIGHTLY WEAKER SOUTH OF I-10...AND ONLY HAVE
CHANCE TO LIKELY POPS FOR THESE AREAS. THE RAIN THREAT SHOULD
QUICKLY DIMINISH BY THIS EVENING AS THE DRY LINE PUSHES INTO
ALABAMA AND FLORIDA AND STRONG DRY AIR ADVECTION AND SUBSIDENCE
OVERTAKES THE AREA.
THE SEVERE THREAT SHOULD ALSO BE GREATEST NORTH OF THE I-10
CORRIDOR...WHERE SPEED SHEAR...DIRECTIONAL SHEAR...AND MLCAPE
VALUES ARE MAXIMIZED. LAPSE RATES WILL BE QUITE STEEP...AND A LOW
WET BULB ZERO HEIGHT OF ONLY 8200 FEET WILL BE FAVORABLE FOR SOME
HAIL FORMATION IN THE STRONGEST STORMS. HELICITY VALUES OF 250
M2/S2 OR HIGHER CAN BE EXPECTED THIS AFTERNOON...SO ANY SUSTAINED
CONVECTION SHOULD BEGIN TO ROTATE AND TAKE ON SUPERCELL
CHARACTERISTICS. THUS...A RISK OF A FEW TORNADOES FORMING WILL
ALSO BE PRESENT THIS AFTERNOON AND EVENING.
THE ENTIRE AREA SHOULD MOSTLY CLEAR SKIES AND DRY WEATHER IN PLACE
BY TOMORROW MORNING...AS DEEP LAYER NORTHWEST FLOW ALOFT AND A
STRONG SURFACE RIDGE OVERTAKE THE GULF SOUTH. THIS SAME GENERAL
PATTERN SHOULD PERSIST INTO WEDNESDAY AS WELL. NOT MUCH IN THE WAY
OF COLD AIR ADVECTION IS EXPECTED WITH THIS RIDGE OF HIGH
PRESSURE...SO TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE
AVERAGE IN THE 60S AND LOWER 70S BOTH DAYS. OVERNIGHT LOWS WILL
COOL INTO THE 40S AND LOWER 50S BOTH NIGHTS.
.LONG TERM...
HEADING INTO THE LATTER HALF OF THE WEEK...DEEP LAYER RIDGING WILL
DEVELOP OVER THE AREA...AS A STRONG UPPER LEVEL HIGH MOVES IN FROM
THE SOUTHERN PLAINS AND BECOMES CENTERED OVER THE GULF SOUTH.
SINKING AIR THROUGHOUT THE ATMOSPHERIC COLUMN...ALONG WITH A
RETURN TO ONSHORE FLOW WILL ALLOW TEMPERATURES TO WARM EVEN
FURTHER. HIGHS WILL EASILY CLIMB INTO THE MIDDLE TO UPPER 70S
THURSDAY THROUGH SUNDAY...AND OVERNIGHT LOWS SHOULD ONLY DIP INTO
THE 50S FOR MOST LOCATIONS. CONDITIONS MAY BE FAVORABLE FOR
ADVECTION FOG TO DEVELOP AS DEWPOINTS RISE INTO THE UPPER 50S AND
LOWER 60S. THE BIGGEST CAVEAT WILL BE JUST HOW STRONG WINDS ARE
DURING THE OVERNIGHT HOURS. IF WINDS FALL TO AROUND 5 TO 10
MPH...ADVECTION FOG COULD BE VERY LIKELY DURING THIS PERIOD. HAVE
NOT INCLUDED A MENTION OF FOG IN THE FORECAST YET...DUE TO THE
UNCERTAINTY IN PLACE.
&&
.AVIATION...
MOST LOCATIONS ARE VFR WITH CIGS AT OR ABOVE SCT-BKN040...EXCEPT
OVC010 AT KMCB. CONVECTION DEVELOPING STEADILY FROM KMCB TO KLFT
WITH ANOTHER SURGE OF SHOWERS MOVING INTO KBTR. CIGS SHOULD LOWER TO
MVFR LEVELS WITH CONVECTION THIS MORNING...THEN BECOMING
PREDOMINANTLY MVFR BASED DURING THE AFTERNOON PRIOR TO WIND SHIFT.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR CAVOK SHORTLY AFTER WIND
SHIFT FROM WEST TO EAST. 24/RR
&&
.MARINE...
SOME GRADIENT RESPONSE THIS MORNING HAS WINDS IN THE 15-
20KT RANGE THIS MORNING. AS THE SURFACE LOW CURRENTLY DEVELOPING
OVER EAST TEXAS EJECTS NORTHEAST THIS MORNING...WINDS SHOULD LESSEN
TO AROUND 15 KNOTS SUSTAINED WHILE VEERING SOUTHWEST. LOW WILL THEN
SLINGSHOT A COLD FRONT INTO THE NORTH GULF THIS EVENING WHICH WILL
SWEEP EASTWARD RATHER QUICKLY OVERNIGHT. GRADIENT PRE-FRONTAL
APPEARS STRONGER THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION.
THIS SHOULD REDUCE THE WINDS TO JUST MODERATE LEVELS TONIGHT AND
TUESDAY. WINDS AND SEAS SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES
WITH BETTER COLD AIR ADVECTION LATE THURSDAY INTO FRIDAY. 24/RR
&&
.DECISION SUPPORT...
DSS CODE....YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND
MISSISSIPPI RIVER AT RED RIVER LANDING.
MARGINAL/SLIGHT RISK OF SEVERE WEATHER MONDAY.
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 69 40 71 43 / 90 20 0 0
BTR 72 45 73 45 / 80 20 0 0
ASD 71 44 71 45 / 80 30 10 0
MSY 71 47 68 50 / 70 20 0 0
GPT 68 44 67 45 / 70 40 10 0
PQL 69 40 69 43 / 60 50 10 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
32
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
407 AM EST MON FEB 15 2016
.SYNOPSIS...ARCTIC HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD
OFFSHORE OVERNIGHT. LOW PRESSURE WILL IMPACT THE REGION MONDAY
THROUGH TUESDAY BRINGING SIGNIFICANT WINTRY PRECIPITATION. HIGH
PRESSURE BUILDS FOR THE MIDDLE AND LATTER PART OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...INITIAL BATCH OF WARM AIR ADVECTION
PRECIP HAS MOVED OVER THE AREA PRODUCING BETWEEN 1.5 TO 4 INCHES
OF SNOW WITH 20 TO 1 SNOW LIQUID RATIOS PER SPOTTER REPORTS. BASED
ON RADAR TRENDS AND HRRR THERE COULD BE A LULL IN THE PRECIP OVER
THE NRN HALF OF THE FCST AREA THIS MORNING BETWEEN 09Z-12Z BUT
SOUTHERN AREAS WILL LIKELY CONTINUE TO SNOW. ADDITIONAL MOISTURE
THEN GETS DRAWN NWD MID MORNING THROUGH THE DAY AS LOW PRES OVR
THE SRN MS VALLEY BEGINS TO ORGANIZE AND COASTAL FRONT ALONG THE
CAROLINAS BEGINS TO MOVE INLAND. WARMER AIR ALOFT WILL BEGIN TO
SURGE NWD THIS AFTERNOON WITH A RAPID TRANSITION TO FZRA/PL OVER
SRN AREAS AND SNOW MIXING IN WITH ICE PELLETS ALONG THE MASON-
DIXON LINE. SFC TEMPS WILL STAY BELOW FREEZING INTO THE EVENING AS
MODELS SHOW BROAD SFC RIDGING ALONG THE APPALACHIANS MAINTAINING
IN SITU DAMMING. BY MIDNIGHT...LARGE SCALE HEIGHT FALLS AND
STRENGTHENING SFC LOW WILL DRAW A BIG SLUG OF MOISTURE INTO THE
REGION WHILE COASTAL FRONT MOVES FARTHER INLAND. SFC RIDGING
ALONG THE MTNS BEGINS TO WEAKEN AS STRONG PRESSURE FALLS DEVELOP
OVER THE AREA WITH COLD AIR BEGINNING TO SCOUR OUT EAST OF THE
MTNS. FZRA WILL BEGIN TO CHANGE TO RAIN IN MOST PLACES AFTER
MIDNIGHT BUT MAY LINGER LONGER OVER THE NRN SHENANDOAH VALLEY AND
WESTERN MD. SEE WSW PRODUCT FOR SPECIFIC SNOW AND ICE AMOUNTS.
&&
.SHORT TERM /TUESDAY/...BY 12Z TUE...SFC LOW IS CROSSING THE
APPALACHIANS AND SFC RIDGING IS GONE SUGGESTING EVERYONE SHOULD BE
ABOVE FREEZING. HEAVY RAINS EXPECTED THROUGH THE MORNING AS CDFNT
CROSSES THE AREA WITH RAIN ENDING FROM WEST TO EAST IN THE
AFTERNOON. ONE TO TWO INCHES OF TOTAL QPF EXPECTED FOR THE EVENT
WHICH MAY RESULT IN FLOODING ISSUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...TUESDAY NIGHT FORECAST
REMAINS LOW CONFIDENCE ATTM AS UPPER LEVEL TROUGH AND COMPACT SFC
LOW SWING ACROSS THE AREA. QUITE A DIFFERENCE IN QPF PLACEMENT
BETWEEN GFS (CENTRAL/SOUTHERN VA) AND THE ECMWF (EASTERN TN). HAVE
SLIGHTLY HIGHER POPS ACROSS SOUTHERN TIER...BUT AT CHANCE IN MOST
PLACES. THERMAL PROFILES COOLING...SO COULD SEE RAIN/SNOW MIX.
WILL HAVE TO WATCH THE TRENDS DURING THIS TIME PERIOD...BUT
HIGHEST CONFIDENCE OF LIGHT SNOW ACCUMULATIONS WILL BE IN THE
UPSLOPE REGION.
MID/UPPER TROUGH REMAINS OVER EASTERN CONUS WEDNESDAY...HOWEVER
TEMPERATURES REMAIN NEAR NORMAL. A WEAK COLD FRONT CROSSING LATE
WEDNESDAY WILL BRING A SHOT OF CAA ADVECTION AND A CONTINUED CHANCE
FOR UPSLOPE SNOW SHOWERS. HEIGHTS THEN RISE FOR THE REMAINDER OF THE
WORK WEEK WITH HIGH PRESSURE BUILDING. A WARM FRONT WILL PASS FRIDAY
NIGHT WITH A SMALL CHANCE OF SHOWERS...AND THIS WILL LEAD TO A VERY
MILD SATURDAY. A COLD FRONT WILL THEN CROSS THE AREA SATURDAY
NIGHT...ALTHOUGH THE BULK OF THE FORCING AND MOISTURE STAYS TO THE
NORTH. MODEL SPREAD INCREASES BY SUNDAY...ALTHOUGH ATTM IT LOOKS
LIKE THE IMMEDIATE REGION WILL BE UNDER THE INFLUENCE OF HIGH
PRESSURE.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...IFR CONDITIONS TODAY
THROUGH MIDDAY TUE. SNOW TRANSITIONING TO SN/PL AFTER 18Z THEN TO
FZRA AFTER 21Z. SFC TEMPS BEGIN TO RISE AFTER 06Z TUE WITH FZRA
BECOMING RAIN XCPT PERHAPS AT KMRB. BY 12Z TUE...PRECIP SHOULD
HAVE TURNED TO ALL RAIN EVERYWHERE.
WILL HAVE TO WATCH WEAK LOW PRESSURE TUESDAY NIGHT/EARLY WEDNESDAY
WHICH COULD BRING SOME LIGHT PRECIP...POSSIBLY RASN MIX. OTHERWISE
VFR LIKELY THROUGH REMAINDER OF OUTLOOK PERIOD. NW WINDS COULD GUST
TO 25 KT WEDNESDAY NIGHT/THURSDAY...WITH S WINDS POTENTIALLY GUSTING
TO 25 KT FRIDAY.
&&
.MARINE...SMALL CRAFT ISSUED FOR THE WATERS BEGINNING LATE TONIGHT
AND CONTINUING THROUGH TUE AS SRLY WINDS STRENGTHEN IN RESPONSE TO
DEVELOPING LOW.
PERIODIC...IF NOT NEARLY CONTINUOUS OVER PORTIONS OF THE
WATERS...THREAT OF SCA-LEVEL WINDS WILL RUN FROM TUESDAY NIGHT INTO
THE FIRST PART OF THE WEEKEND. THE PERIODS OF STRONGEST WINDS WILL
OCCUR WEDNESDAY NIGHT AND EARLY THURSDAY (NW) BEHIND A COLD
FRONT...THEN IN S FLOW AHEAD OF THE NEXT COLD FRONT FRIDAY INTO
SATURDAY...EVENTUALLY BECOMING SW. GALE FORCE WINDS WILL NOT BE TOO
FAR ALOFT...BUT MIXING LOOKS POOR ATTM.
&&
.TIDES/COASTAL FLOODING...WATER LEVELS WILL BEGIN TO RISE LATE
TONIGHT WITH MINOR COASTAL FLOODING EXPECTED TUE AFTERNOON AT
SENSITIVE LOCATIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR MDZ003-004-
501-502.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ013-014-
016-503>506.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ005-006-
011-507-508.
WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR MDZ017-018.
VA...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR VAZ025>031-
036>040-501-503>505-507-508.
WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR VAZ050>057-
502-506.
WV...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ050>053-
055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR
ANZ532>534-537-540>543.
SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR ANZ530-
531-535-536-538-539.
&&
$$
SYNOPSIS...LFR
NEAR TERM...LFR
SHORT TERM...LFR
LONG TERM...ADS
AVIATION...ADS/LFR
MARINE...ADS/LFR
TIDES/COASTAL FLOODING...LFR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1225 AM EST MON FEB 15 2016
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 419 PM EST SUN FEB 14 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW DEAMPLIFYING FLOW ACROSS N
AMERICA. DEEP TROF THAT WAS OVER SE CANADA/NE CONUS 24HRS AGO IS
LIFTING NE...LEAVING BEHIND A BROAD TROF OVER THE CNTRL AND ERN
CONUS DOWNSTREAM OF A BROAD RIDGE CENTERED JUST OFF THE W COAST. A
VIGOROUS LOOKING SHORTWAVE IS TRACKING ACROSS NRN IL. ASSOCIATED
SHIELD OF SNOW HAS PASSED S OF THE AREA TODAY. UPSTREAM...SHORTWAVE
TROF OVER MANITOBA/WRN MN WILL BE THE NEXT FEATURE OF INTEREST
DURING THE SHORT TERM. MEANWHILE...INCREASING SOUTHERLY FLOW ON THE
BACKSIDE OF HIGH PRES NOW OVER THE LOWER LAKES/MID ATLANTIC STATES
IS BRINGING LES NORTHWARD OFF LAKE MI UNDER 850MB TEMPS AROUND -16C
ACROSS THE N HALF OF THE LAKE PER LATEST RAP ANALYSIS. SATELLITE AND
RADAR IMAGERY INDICATE LES HAS NOT BEEN WELL ORGANIZED AS IT LIFTED
N INTO THE SE FCST AREA THIS AFTN. THE HEAVIER SNOW HAS IMPACTED
MENOMINEE COUNTY...BUT WEB CAMS SUGGEST SNOW ACCUMULATIONS HAVE BEEN
UNDER 1 INCH.
AFOREMENTIONED SHORTWAVE TROF ACROSS WRN MN WILL SHIFT E...REACHING
CNTRL LAKE SUPERIOR/CNTRL UPPER MI AROUND 12Z MON. MODELS ARE IN
GOOD AGREEMENT SHOWING A PERIOD OF DEEP LAYER FORCING PER QVECTORS
AND A CORRESPONDING INCREASE IN DEEPER MOISTURE AHEAD OF FEATURE.
THIS SHOULD YIELD AT LEAST SOME AREAS OF -SN MOVING ACROSS THE FCST
AREA TONIGHT. OF MORE INTEREST IS WHAT HAPPENS DOWNWIND OF LAKE MI.
WITH 850MB TEMPS OF -13/-14C ACROSS NRN LAKE MI...SYNOPTIC
FORCING/DEEPER MOSITURE WILL LEAD TO A PERIOD OF LAKE ENHANCEMENT.
IN ADDITION...AS WEAK SFC TROF ASSOCIATED WITH SHORTWAVE MOVES
ACROSS THE AREA...THE CONVERGENCE ALONG THE TROF SHARPENS UP AS IT
REACHES LAKE MI...LEADING TO A FOCUSING OF THE LAKE ENHANCED SNOW.
FCST SOUNDINGS SHOW THE DGZ ENCOMPASSING A VERY DEEP LAYER 9-10FT
THICK. WHILE MODELS DON`T SHOW MUCH UPWARD MOTION IN THAT LAYER DUE
TO THE OVERALL WEAK SYNOPTIC FORCING...IT WILL STILL HELP FLUFF UP
SNOW ACCUMULATIONS. SFC TROF STEADILY CROSSES NRN LAKE MI/SE FCST
AREA ROUGHLY DURING THE 09Z-21Z TIME FRAME. STEADY PROGRESSION WILL
LIMIT SNOW ACCUMULATIONS...BUT POTENTIAL IS THERE FOR SEVERAL INCHES
OF SNOW. FOR NOW...FCST WILL SHOW TOTAL SNOW ACCUMULATION
TONIGHT/MON OF 2-3 INCHES WITH LOCAL 4 INCH AMOUNTS FROM MENOMINEE
COUNTY INTO LUCE COUNTY...SUB ADVY AMOUNTS. HOWEVER...WILL NEED TO
MONITOR THE INCREASE IN ENHANCEMENT ALONG/JUST AHEAD OF THE SFC
TROF. SINCE MUCH OF THE SNOW ACCUMULATION WILL OCCUR WITH THIS
FEATURE AND OVER A RELATIVELY SHORT PERIOD OF TIME...THE HIGHER
SNOWFALL RATES MAY REQUIRE ISSUANCE OF AN ADVY LATER. ELSEWHERE...
SNOW ACCMULATIONS SHOULD BE UNDER 1 INCH. WITH PASSAGE OF SFC
TROF...-SN WILL END.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 252 PM EST SUN FEB 14 2016
FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS
TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY
LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE
SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS
WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE
SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS
THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z
THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN
BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT
BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW-
NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED
MORNING).
ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW
A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH
RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL
IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND
CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY
LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE
A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO
SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD
SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL
FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW
FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE
FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5
INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM
HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES
INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE
THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL
POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR
SIGNIFICANT LAKE EFFECT.
VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES
LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH
POTENTIAL FOR SOME DISTURBANCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1224 AM EST MON FEB 15 2016
AN UPPER DISTURBANCE MOVING ACROSS THE UPPER LAKES WILL RESULT IN
-SN LATE TONIGHT INTO MON MORNING WITH MVFR CONDITIONS PERSISTING
THROUGH MUCH OF THE FCST PD AT ALL TAF SITES. VSBY COULD
OCCASIONALLY FALL TO IFR AT KSAW LATE TONIGHT AND EARLY MON MORNING
AS ADDITIONAL MOISTURE ADVECTS N OFF LAKE MI. WITH A DOWNSLOPE S
WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD WILL LIKELY SEE THE
SHORTEST PERIOD OF -SN OVERNIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST SUN FEB 14 2016
TIGHTENING PRES GRADIENT BETWEEN HIGH PRES NEAR THE E COAST AND A
LOW PRES TROF APPROACHING FROM THE W WILL RESULT IN SOUTHERLY WINDS
OF 20-30KT TONIGHT. THE STRONGEST WINDS WILL OCCUR OVER THE E HALF
OF THE LAKE WHERE THERE MAY BE A FEW GALE FORCE GUSTS TO 35KT. WINDS
WILL DIMINISH MON AS PRES GRADIENT WEAKENS. AFTER A PERIOD OF
RELATIVELY LIGHT WINDS UNDER 20KT MON NIGHT/TUE MORNING...PASSAGE OF
A COLD FRONT TUE WILL BRING A PERIOD OF STRONGER NORTHERLY WINDS OF
20-30KT. THERE MAY BE A PERIOD OF GALES OVER THE CNTRL PORTION OF
THE LAKE TUE NIGHT IN ADDITION TO HEAVY FREEZING SPRAY. WINDS WILL
THEN DIMINISH TO UNDER 20KT WED WITH ARRIVAL OF ANOTHER HIGH PRES
RIDGE. STRONGER SSE WIND UP TO 30 KTS WILL ARRIVE ON THU UNDER A
TIGHTENING PRES GRADIENT BETWEEN THIS HIGH SHIFTING TO THE E AND
ANOTHER APPROACHING LOW PRES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1134 PM CST SUN FEB 14 2016
.UPDATE:
Issued at 957 PM CST Sun Feb 14 2016
There may be some patchy freezing drizzle still over parts over
south central Illinois this evening. Recent radar trends have been
showing returns over this area that as it moves east, and recent
runs of the RAP are showing a drying trend at and above 925mb
after 06Z, so will carry patchy freezing drizzle until midnight.
Otherwise, have been seeing an increase in lowering visibilities
over the southern and eastern counties this evening, so went ahead
and introduced areas of fog for the rest of the the night.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 219 PM CST Sun Feb 14 2016
Most of the snow has shifted east of our forecast area this
afternoon as the shortwave was moving eastward into northwest IL.
Will keep the winter weather advisory going for parts of west
central and southwest IL until 6 pm due to patchy freezing
drizzle. The threat for patchy freezing drizzle should end later
this evening as the low level stratus cloud deck shifts east of
the area. Mid-high level cloudiness will spread back into the area
late tonight as another shortwave dives southeastward through the
Plains. Went a little colder than MOS temperature guidance for
tonight due to the new snow cover over much of the area. Rest of
the forecast still looks on track.
GKS
.LONG TERM: (Monday through Next Sunday)
Issued at 219 PM CST Sun Feb 14 2016
A shortwave and an associated surface low will pass south of our
area on Monday. Precipitation with this feature should remain
south of the forecast area, but the GFS model does generate a few
areas of light QPF over our region on Monday. Could not rule out
some patchy light rain/snow over our area on Monday. Temperatures
will be noticeably warmer on Monday, finally getting well above
the freezing mark for much of the area after a cold weekend. A
strong northwest flow shortwave and associated weak surface low will
be dropping southeastward through our area late Monday night and
Tuesday bringing another shot of rain/snow to the area. The NAM
and GFS models are similar in generating most of their QPF across
northeast MO and west central and southwest IL, but the ECMWF
model continues to have a more southwest track to the weather
system and has most of its QPF west of the Mississippi River. For
now will lean toward the NAM and GFS model solutions and put my
highest pops over northeast MO and west central and southwest IL.
Although temperatures will be fairly warm again on Tuesday there
will be the potential for a little accumulating snow late Monday
night and Tuesday morning across northeast MO and west central IL.
The models continue to depict unseasonably warm and windy
conditions for the end of the work week as an upper level ridge
moves over the region on Thursday, along with strong south-
southwesterly winds due to a tight surface pressure gradient over
our area ahead of a low pressure system moving eastward through the
northern Plains. Our next chance of measurable rain should occur
mainly Saturday night as a weak low pressure system moves
eastward through southern portions of MO and IL.
GKS
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1118 PM CST Sun Feb 14 2016
Expect that VFR conditions currently over the St. Louis area
terminals is only temporary, and that MVFR and IFR conditions will
redevelop back over the next 1-3 hours. Expect these same
conditions to persist at KUIN and KCOU through mid morning before
improving through the day. There will be a weak storm system move
through the area that may bring some light rain or snow to the
area during the day...but chances are so low that I will not
include in the TAF at this point.
Specifics for KSTL: Expect current VFR conditions to be only
temporary before MVFR and possibly IFR conditions move back into
the terminal in the next 1-3 hours. These conditions will persist
through mid morning before they improve back to VFR. There will be
a weak storm system move through the area that may bring some
light rain or snow late in the morning or during the
afternoon...but chances are too low to include in the TAF at this
time. An additional chance of rain or snow will occur late on
Monday night...but here again...chances are not high enough this
far out to include in the TAF.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1105 PM CST SUN FEB 14 2016
.UPDATE...
ISSUED AT 825 PM CST SUN FEB 14 2016
RADAR INDICATES SOME LIGHT TO MODERATE SNOW SHOWERS CROSSING
SOUTHWEST NEBRASKA AND SATELLITE CLOUD TEMPERATURES OF -41C
INDICATE THAT THERE IS SOME VERTICAL EXTENT...THUS WE HAVE UPDATED
TO INCLUDE A LITTLE MORE THAN SPRINKLES/FLURRIES. STILL...BECAUSE
THE SHOWERS ARE MOVING QUICKLY...ACCUMULATIONS WILL BE MINIMAL.
UPDATE ISSUED AT 747 PM CST SUN FEB 14 2016
TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE
SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN
CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR
THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS
PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL
TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM
APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON.
THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND
RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR
ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES
OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN
THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS
AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA
FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST
SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS
SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS
850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS
NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP
FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT
SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY
ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/
FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY
SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE
FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND
LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL
MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER
SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR
CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS.
MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND
MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE
DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT
WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW
LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING.
ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS
THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER
CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CST SUN FEB 14 2016
MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL
DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA
WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE
IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF
THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S.
COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE
IS RAIN.
THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE
80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF
NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB
MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER.
THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE
LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE
TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE
AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS.
THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH
H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE
UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY
CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE
OVERHEAD IN THE AFTERNOON.
WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST-
SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES
RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND
ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND
INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC
LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE
FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT.
A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE
TEMPERATURE FORECAST.
A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A
PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS
AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY
AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND
GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR
THIS POTENTIAL WIND EVENT.
LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD
SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES
COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60.
DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO
SUPPORT DEEP VERTICAL MIXING.
ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE
NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT
H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE
FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT.
SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE
SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE
MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE
SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE
BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE
ROCKIES DOMINATES THE COLDER ARCTIC AIR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1105 PM CST SUN FEB 14 2016
VISUAL METEOROLOGICAL CONDITIONS ARE FORECAST THROUGH TONIGHT IN
CENTRAL AND WESTERN NEBRASKA. AFTER 14Z...CEILING WILL BECOME
UNLIMITED UNTIL MIDDLE CLOUDS MOVE IN AGAIN LATE AFTERNOON.
WIND IS EXPECTED TO BECOME 270-300 AT 10-14KT AND BECOME GUSTY IN
NORTHERN NEBRASKA AFTER 02Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SPRINGER
SHORT TERM...SNIVELY
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
108 AM EST MON FEB 15 2016
.SYNOPSIS...
BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT
SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM
SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY
EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE
AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
910 PM UPDATE..
LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT
TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER
SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY
LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH
SHOULD SLOW THE FALL OF TEMPERATURES.
I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES
FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON
CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE
VARIABILITY FROM SITE TO SITE.
4PM UPDATE...
LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS
AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE
OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM
THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE
REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL
TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION.
850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE
TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN
THE SINGLE DIGITS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH TUESDAY NIGHT/...
915 PM UPDATE...
ONE MINOR UPDATE: WE ADDED FLURRIES TO THE FORECAST FOR MUCH OF
THE REGION, BEGINNING MID-MORNING. THE NAM AND GFS BOTH GENERATE
LIGHT PRECIPITATION UNDER A FAST MOVING SHORT WAVE. WE ALSO MADE
SMALL CHANGES TO THE MONDAY MORNING AND AFTERNOON QPF/SNOW FIELDS.
4 PM SUNDAY UPDATE...
A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED
TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES
TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS
BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT.
MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE
EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA-
CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO
INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST
PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND
WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL
STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER
AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH
CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND
WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN
ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL
IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION
FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN
BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT.
GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE
COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN
ISSUED.
WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN
A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE
SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE
FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO
PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE
NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE
THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS
HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR
POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO
FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS
SITUATION CLOSELY, AND WILL CONTINUE TO DO SO.
THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN
DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW
AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE
NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
442 PM UPDATE...
VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA
WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS
FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST.
AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE
REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A
POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR
TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN,
POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE
MORNING.
TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT
PASSES LATE SATURDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS
ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT
THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL
DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY
AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT
OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL
PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL
PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE
TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT
LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT
IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER
AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT
PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT
WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM
THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z
ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY
KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. A
CHANGE TO A WINTRY MIX OF A FEW ICE PELLETS OR MAINLY FREEZING
RAIN EXPECTED AROUND 02Z KAVP, AND TOWARD 05Z/06Z KITH/KBGM/KELM.
WINDS THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE
OVERNIGHT...THEN SE OR S 8-12 KTS MONDAY.
.OUTLOOK...
TUE...RESTRICTIONS IN SNOW OR WINTRY...BECOMING MAINLY RAIN TUE.
TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO
SNOW ON BACK END OF DEPARTING STORM.
WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN.
THU-EARLY FRI...VFR.
LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH
MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR PAZ038>040-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR NYZ023>025-036-037-044>046-055>057-062.
WINTER STORM WATCH FROM THIS AFTERNOON THROUGH TUESDAY EVENING
FOR NYZ009-015>018-022.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...DJP/KAH
SHORT TERM...DJP/MLJ
LONG TERM...DJP
AVIATION...HEDEN/MDP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
339 AM CST MON FEB 15 2016
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS
SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE
BLEND FOR NOW.
A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE
OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME
WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER
THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR
IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE
WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES
SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF
CLOUD COVER.
NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA
THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING
BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT
GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY
WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT
STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL
NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST
SW OF THE FA.
FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING
COOLER TEMPERATURES TO THE REGION TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH
BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE
WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR
WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY
LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO.
HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND
WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO
RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY.
WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD.
THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID-
LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH
THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO
MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE
DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS
AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH
BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE
AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL
FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER
AIR FEATURES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1146 PM CST SUN FEB 14 2016
IFR CIGS EAST OF THE RED RIVER VALLEY...STILL HAVE SOME LIGHT FOG
AND FREEZING DRIZZLE IN SPOTS. MAIN ISSUE IS CLEARING TREND INTO
THE RED RIVER VALLEY AND IF OR WHEN WILL IT OCCUR AND ANY FOG IF
IT DOES CLEAR. SO CONFIDENCE IS LOWER THAN USUAL. OVERALL BROUGHT
IN VFR CIGS TO DVL/GFK/FAR PAST 12Z MON.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 1217 AM CST MON FEB 15 2016
VISIBILITIES IN THE JAMES BASIN HAVE VARIED FROM 1/4 MILE TO 6+ AND
WILL KEEP THE MENTION OF AREAS OF FOG THERE WITH PATCHY DENSE FOG.
LIGHT FOG POSSIBLE FARTHER WEST TOWARDS BISMARCK AND MINOT AS PER
HIGHRES MODELS. OTHERWISE ONLY MINOR CHANGES IN HOURLY TEMPERATURE
TRENDS.
UPDATE ISSUED AT 903 PM CST SUN FEB 14 2016
NORTH DAKOTA DOT WEBCAMS SHOWING SCATTERED AREAS OF FOG FORMING AT
ASHLEY...DUNSEITH...KULM AND PETTIBONE. ALSO SEEING FOG AT
JAMESTOWN AND HARVEY AIRPORTS. ALTHOUGH THERE WILL BE SOME
VARIABILITY IN VISIBILITY AS IS TYPICAL...READY TO GO WITH AREAS
OF FOG JAMES RIVER VALLEY NORTH THROUGH RUGBY AND DUNSEITH AND
PATCHY FOG TO THE WEST INTO THE MISSOURI AND PORTIONS OF THE
SOURIS RIVER VALLEYS. WILL MONITOR FOR ANY DENSE FOG ADVISORIES
NEEDED BUT NOT AT THIS TIME.
UPDATE ISSUED AT 557 PM CST SUN FEB 14 2016
MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT
ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM
MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR
FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR
PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG
POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE
AMOUNT OF MID/HIGH CLOUDS REMAIN.
THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA.
CURRENT FORECAST TRACKING WELL SO FAR.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG
POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT
RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON.
FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN
THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF
OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC.
FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK
/LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED
LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON
ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL
ONLY LOWER THROUGH THE REST OF THE DAY.
TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT
OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000
FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19
UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC
NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY
BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER
INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES
MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE
EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT
SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND
DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD.
ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE
TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN
CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON
MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND
POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE
APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG
SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON.
WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN
AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY
BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER
ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING
WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH
850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW
IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF
0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CST SUN FEB 14 2016
ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE
WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW
PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD.
MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING
ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION
TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT
WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE
SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE
GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS
WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE
HWO WITH THIS FORECAST ISSUANCE.
THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY
THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH
THIS S/WV.
BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY
ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S
EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE
SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND
MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS
CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE.
UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY.
MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE
SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE
END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH
KEEPING AN EYE ON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1217 AM CST MON FEB 15 2016
FOG CONTINUED IN THE JAMES RIVER VALLEY. LATEST ITERATIONS OF SHORT
TERM MODELS SUPPORT CONTINUED FOG THIS MORNING WITH VSBYS OF 1/4SM
TO 3/4SM THROUGH 12Z...THEN IMPROVING AFT 12Z AS SOUTHWEST
WINDS...THEN WEST WINDS DEVELOP. MODELS ALSO HINTING AT LIGHT FOG
POSSIBLE AT KBIS-KMOT WITH VSBYS AROUND 3SM. VFR AT KISN-KDIK UNTIL
MONDAY AFTERNOON AS THE NEXT SYSTEM MOVES IN WITH MVFR AND CHANCES
OF RAIN/SNOW. MVFR CIGS TO REACH KMOT-KBIS LATE AFTERNOON...AND AFT
00Z AT KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...CJS
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
109 AM EST MON FEB 15 2016
.SYNOPSIS...
COMPLEX SYSTEM GIVES MESSY CONCOCTION OF WINTRY WEATHER THEN
WATER CONCERNS. THE SYSTEM EXITS EARLY TUESDAY...FOLLOWED BY
ANOTHER SYSTEM TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
100 AM UPDATE...
UPDATED POPS TO REFLECT DIMINISHING PRECIPITATION OVER THE MIDDLE
OHIO VALLEY OVERNIGHT ACCOUNT OF MID LEVEL DRY AIR INTRUSION FROM
THE W. THIS MAY NECESSITATE ADJUSTMENTS TO WARNINGS EARLY THIS
MORNING. THE MAIN WARM ADVECTION SNOW EVENT WAS STILL OCCURRING
OVER THE CENTRAL AND SRN MOUNTAINS...AND CONTINUED MOVING E.
PREV DISCN...
900 PM UPDATE...EXTENDED WINTER STORM WARNINGS A ROW OR TWO
COUNTIES TO THE NORTH OF THE PREVIOUS WARNING IN THE TRISTATE AREA
DUE TO RADAR IMAGERY INDICATING A HEAVY BAND OF SNOW ORIENTED
ALONG THE I-64 CORRIDOR. ALSO...THE HI-REZ MESOSCALE MODELS LIKE
THE HRRR AND NCAR ENSEMBLES INDICATED QUITE A BIT MORE QPF THAN
THE DETERMINISTIC NATIONAL SUITE. ALSO EXTENDED ADVISORIES TO THE
NORTHERN TIER OF THE CWA...MAINLY TO HIGHLIGHT THE SNOW TONIGHT
AND POTENTIAL FOR FREEZING RAIN TOMORROW.
SNOW TO SLEET TO FREEZING RAIN OR JUST RAIN CHANGEOVER STILL LOOKS
ON TRACK FOR TOMORROW MORNING IN AND AROUND THE 6 AM TO NOON
TIMEFRAME DEPENDING ON LOCATION. SOME LOCATIONS IN THE MOUNTAINS
LIKE POCAHONTAS COUNTY COULD SEE SIGNIFICANT ICE ACCUMULATIONS OF
OVER A 1/4 TO 1/2 AN INCH...SO BE AWARE OF THAT.
PREVIOUS DISCUSSION FOLLOWS...
FLAKES SHOULD BE REACHING GROUND ON SCHEDULE IN THE TRI STATE
AROUND HTS ON SE TO SOUTHWEST VIRGINIA...NOW THROUGH DARK.
MAIN CHANGE WAS JUST TO ADD BOONE AND FAYETTE TO THE SOUTHERN
WARNING. ALSO WILL ADD JUST A FEW COUNTIES WITH THE LOWER SNOW
CRITERIA TO AN ADVISORY...INCLUDING ATHENS...WOOD...WIRT AND
CALHOUN.
AS SNOW CHANGES TO RAIN...ADDED SOME POCKETS OF FREEZING RAIN
MONDAY IN NORTH CENTRAL WEST VIRGINIA DUE TO THE COLD GROUND.
MAY EVEN BE SOME FREEZING AT 33 OR 34 DEGREES. NO REASON FOR AN
ADVISORY AT THIS DISTANCE IN TIME.
TEMPERATURES SHOULD HOLD STEADY OR SLOWLY RISE OVERNIGHT AND
MONDAY.
THE INCREASING SOUTHEAST FLOW STILL HAS US CONCERNED ABOUT THE
FREEZING RAIN FROM THE BECKLEY/OAK HILL VICINITY ON NORTHEAST TO
SNOWSHOE AND THE GREENBRIER VALLEY IN POCAHONTAS COUNTY MONDAY
AFTERNOON...THEN CONTINUING IN POCAHONTAS COUNTY MONDAY NIGHT.
SNOW AMOUNTS WERE MARGINAL FOR BOONE AND FAYETTE COUNTIES FOR THE
WARNING.
CONDITIONS IMPROVE 18Z MONDAY TO 00Z IN THE DOWNSLOPE AREAS
ESPECIALLY WILLIAMSON...LOGAN...MADISON...CHARLESTON VICINITY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
MONDAY NIGHT...MOST OF THE FORECAST AREA WILL HAVE TURNED TO ALL
RAIN HOWEVER COLD AIR BECOMES WEDGED EAST OF APPALACHIANS AND NEAR
THE SURFACE TEMPERATURES WILL LIKELY HANG AROUND TO SLIGHTLY BELOW
FREEZING THROUGH THE NIGHT IN THE MOUNTAINS. WARM LAYER ALOFT IS
MAKING FORECASTING P-TYPES MONDAY NIGHT A CHALLENGE FOR THE
MOUNTAINS. CURRENT THINKING IS STARTING THE NIGHT WITH A WINTRY
MIX AND THEN TRANSITIONING TO FREEZING RAIN. POCAHONTAS COUNTY
WILL LIKELY SEE THE BRUNT OF THE ICING WITH AMOUNTS OF OVER A
QUARTER OF AN INCH POSSIBLE.
THE OTHER CONCERN THIS FORECAST PERIOD WILL BE RAINFALL ACROSS THE
LOWLANDS MONDAY NIGHT. CURRENT QPF AMOUNTS FROM MONDAY AFTERNOON
THROUGH TUESDAY ARE CLOSE TO AN INCH IN SOME AREAS AND MINOR
FLOODING ISSUES COULD OCCUR AS RAIN FALLS ONTO FRESH SNOW FROM
EARLIER IN THE EVENT AND FROZEN GROUND. HOWEVER...TEMPERATURES
LOOK TO REMAIN IN THE UPPER 30S TO POSSIBLE LOW 40S SO NOT
EXPECTING A RAPID SNOW MELT AND THE NEW SNOW ON THE GROUND SHOULD
BE ABLE TO ABSORB A LOT OF THE WATER. AT THIS TIME WAS NOT
CONFIDENT ENOUGH IN ANY HYDRO CONCERNS TO ISSUE A FLOOD
WATCH...BUT WILL HIGHLIGHT IN THE HWO FOR NOW.
AFTER A DRIER BUT OVERCAST INTERLUDE BETWEEN SYSTEMS TUE...06Z
MODEL RUNS ARE FARTHER S WITH ANOTHER UPPER LEVEL S/W TROUGH AND
ASSOCIATED LOW PRESSURE SYSTEM PROGGED TO CROSS TUE NT. THIS WOULD
BRING COLDER AIR BACK INTO THE AREA FROM THE W THROUGHOUT THE
COLUMN OVERNIGHT TUE NT...CHANGING ANY RAIN...FREEZING RAIN OR
MIXED PRECIPITATION THAT RETURNS TUE EVENING...BACK TO SNOW...WITH
LIGHT ADDITIONAL AMOUNTS POSSIBLE OF GENERALLY 1 TO 3 INCHES.
USED MOSTLY NAM FOR TEMPERATURES ALOFT AND USED A VARIETY OF
GUIDANCE AS WELL AS PREVIOUS OFFICIAL FORECAST FOR SFC TEMPS. QPF
AMOUNTS ARE GENERALLY A MIX BETWEEN RFC AND MODEL GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
OVERALL...QUIET AND WARMER WEATHER WILL TAKE HOLD IN THE LONG TERM.
STILL SOME LIGHT UPSLOPE SNOW SHOWERS LINGERING BEHIND DEPARTING
CLIPPER EARLY THURSDAY...BUT DRIER...AND WARMER AIR WILL GRADUALLY
TAKE HOLD AS HIGH PRESSURE SURFACE AND ALOFT BUILD INTO THE REGION.
TEMPERATURES TOWARDS THE END OF THE WEEK COULD EVEN CLIMB INTO THE
50S TO LOWER 60S ACROSS THE LOWLANDS...AS WAA INCREASES OUT AHEAD OF
AN APPROACHING LOW...WHICH WILL SWEEP A COLD FRONT INTO THE REGION
OVER THE WEEKEND...WITH LIGHT RAIN SHOWERS...AND COOLER
TEMPERATURES TO END THE WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
WIDESPREAD IFR GIVING WAY TO IMPROVEMENT TO MVFR/VFR MIDDLE OHIO
VALLEY WITH THE SNOW TAPERING OFF THERE. THE LULL WILL CONTINUE
THROUGH MON MORNING...BEFORE ANOTHER WAVE BRINGS
PRECIPITATION...MAINLY RAIN THIS TIME...BUT IFR CIGS RETURNING
LATE MON AND MON NT. THERE MAY NOT BE MUCH OF A LULL IN THE
MOUNTAINS...BUT PRECIPITATION WILL GO TO A MIX THERE BY EARLY
AFTERNOON BKW AND LATE AFTERNOON EKN...WITH A BRIEF PERIOD OF
SLEET AND FREEZING RAIN IN THE TRANSITION TO EVENTUALLY
RAIN...THIS WILL ALLOW CONDITIONS TO IMPROVE TO MAINLY MVFR IN
THE MOUNTAINS ALTHOUGH BKW WILL HANG NEAR 1 KFT CIG WITH LOWER
CIGS ON HIGHER RIDGES.
SFC FLOW WILL BE S TO SE AND A BIT GUSTY ON THE RIDGES...AND FLOW
ALOFT WILL BE MODERATE TO STRONG FROM THE SW.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: LOW TO MEDIUM
ALTERNATE SCENARIOS: TIMING OF THE TRANSITION FROM SNOW TO RAIN
COULD DIFFER AND VISIBILITIES MAY DROP TO IFR OR BELOW MON AFTERNOON
AND EVENING WITH ADVECTION FOG.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 02/15/16
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY L L L L L L L L L M M M
HTS CONSISTENCY L L L L L M M M M M M M
BKW CONSISTENCY L L L L L L L L L L L M
EKN CONSISTENCY L L L L L M M M M M M L
PKB CONSISTENCY M M L L M M M M M M M M
CKB CONSISTENCY M M M M M M M M M M M M
AFTER 06Z TUESDAY...
PROLONGED IFR CONDITIONS WILL LIKELY PERSIST IN MID OHIO VALLEY
AND CENTRAL APPALACHIANS INTO WED. LOW CIGS AND VSBYS IN MOSTLY
RAIN AND FOG OVERNIGHT MON NT INTO TUE...THEN MIXED LIGHT RAIN
AND SNOW TUE NT INTO WED.
&&
.EQUIPMENT...
HAVING ON/OFF PROBLEMS WITH THE CKB ASOS. TEMPERATURE READING TOO
HIGH AT TIMES. TROUBLE TICKET CLOSED EARLIER BUT RE-OPENED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
WVZ007-008-016-027.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR WVZ005-
006-013>015.
WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
WVZ024>026-033>036.
WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
WVZ009>011-017>020-028>032-039-040.
WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ037-038-
047.
WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ046.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
OHZ083>087.
WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
OHZ066-067-075-076.
KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
KYZ101.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ102-
103-105.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ003-
004.
&&
$$
SYNOPSIS...KTB/MPK/SL
NEAR TERM...TRM/JW
SHORT TERM...MPK
LONG TERM...SL
AVIATION...TRM
EQUIPMENT...TRM
AREA FORECAST DISCUSSION
NWS PORTLAND OR
900 PM PST SUN FEB 14 2016
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH WASHINGTON
TONIGHT...AND RAIN WILL DECREASE FROM THE SOUTH AS HIGHER PRESSURE
BUILDS INTO WESTERN OREGON. WEAK DISTURBANCES MOVING THROUGH
WASHINGTON WILL KEEP THE THREAT OF RAIN AT TIMES PORTLAND NORTHWARD
THROUGH TUESDAY WITH DRIER WEATHER TO THE SOUTH. A COLD FRONT IS
EXPECTED TO MOVE THROUGH WEDNESDAY AFTERNOON AND EVENING... FOLLOWED
BY LOWERING SNOW LEVELS IN THE CASCADES THURSDAY. ANOTHER PACIFIC
FRONT APPEARS LIKELY TO MOVE THROUGH THE FORECAST AREA THURSDAY
NIGHT AND FRIDAY.
&&
.SHORT TERM...RADAR SHOWED MAIN AREA OF RAIN SHIFTING RAPIDLY
NORTHWARD THIS EVENING...UP INTO THE CASCADES AND N INTO NORTHERN WA
WHICH AGREED WELL WITH HRRR AND WRF MESOSCALE MODELS. SURFACE
OBSERVATIONS HOWEVER INDICATED LIGHT PRECIPITATION WAS STILL FALLING
IN THE MOUNTAINS AND ALONG THE COAST FURTHER S THROUGH WESTERN
OREGON...MAINLY IN AREAS WHERE LOW LEVEL OROGRAPHIC LIFT WAS
ACCOMPANIED BY LOW LEVEL MOISTURE. AS THE DEEPER MOISTURE ASSOCIATED
WITH THE BAROCLINIC ZONE LIFTS N TONIGHT AND IS EXPECTED TO REMAIN
TO THE N MON WILL BACK OFF ON POPS IN GENERAL TONIGHT AND MON...BUT
WILL NEED TO HANG ONTO SOME LOW POPS LATER TONIGHT INTO MON MORNING
FURTHER S MAINLY IN THE MOUNTAINS AND ALONG THE COAST WHERE A
WEAKENING MOIST ONSHORE FLOW CONTINUES.
REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...WITH WARMER AIR
MOVING IN ALOFT...THE CHANCE FOR INVERSIONS AND VALLEY FOG WILL BE
INCREASING FOR THE EUGENE AREA TONIGHT/MON MORNING THEN ACROSS MUCH
OF CWA MON NIGHT/EARLY TUE. THIS COULD PUT A MONKEY WRENCH IN THE
TEMPERATURE FORECASTS...BUT FOR NOW GUIDANCE SUGGESTS ANY FOG WILL
BURN OFF EARLY ENOUGH FOR IT TO HAVE LITTLE IMPACT ON MAX TEMPS.
OTHERWISE...WITH 500 MB HEIGHTS AROUND 570 DAM AND 850 MB TEMPS ON
THE ORDER OF +4 TO +8 DEG C...EXPECT TEMPS TO REMAIN A FEW DEGREES
ABOVE NORMAL THROUGH TUESDAY AND PROBABLY WEDNESDAY AS WELL.
NIGHTS WILL BE UNSEASONABLY MILD DUE TO THE HIGH DEWPOINTS ASSOCIATED
WITH THIS MOIST AIR MASS.
MODELS ARE COMING INTO REASONABLE AGREEMENT THAT A COLD FRONT WILL
APPROACH THE PAC NW COAST EARLY WED...SPREADING RAIN ACROSS OUR
FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. EXPECT A QUICK DROP IN
SNOW LEVELS AFTER THIS SYSTEM MOVES THROUGH...WITH SNOW LEVELS
POSSIBLY AS LOW AS THE CASCADE PASSES BY WED NIGHT. 18Z GFS SHOWS
925-850 MB WINDS REACHING 45-55 KT ALONG THE COAST WED AFTERNOON. IF
THIS VERIFIES IT COULD BE A BIT WINDY ALONG THE COAST JUST AHEAD OF
THE FRONT...THOUGH AM INCLINED TO BELIEVE THE NEUTRAL OR NEGATIVE
TILT TO THIS SYSTEM WILL KEEP THE STRONGEST WINDS SOUTH OF OUR
FORECAST AREA.WEAGLE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. WEDNESDAY
NIGHT THROUGH SATURDAY...PROGRESSIVE PATTERN CONTINUES THROUGH LATE
NEXT WEEK...WITH BACK-TO-BACK SYSTEMS BRINGING RAIN THROUGH AT LEAST
FRIDAY. UPPER-LEVEL TROUGH DROPS DOWN OUT OF THE GULF OF ALASKA
MIDWEEK...BRINGING SNOW LEVELS MAYBE FAR ENOUGH DOWN TO BRING SOME
SNOW TO HIGHER ELEVATIONS IN THE CASCADE FOOTHILLS THURSDAY. SNOW
LEVELS COME UP A BIT ON FRIDAY AHEAD OF THE NEXT FRONT MOVING
THROUGH MID-DAY. SNOW LEVELS DROP BACK DOWN BEHIND THIS FRONT FRIDAY
NIGHT FOR ANOTHER BRIEF CHANCE FOR SNOW IN HIGHER ELEVATIONS OF THE
CASCADE FOOTHILLS EARLY SATURDAY. MODELS ARE SUGGESTING RIDGING
BUILDING BACK IN NEXT WEEKEND WHICH WOULD BRING BACK DRY OFFSHORE
FLOW. -MCCOY
&&
.AVIATION...STEADIER RAIN TAPERING OFF THIS EVENING AS A WARM
FRONT LIFTS WELL NORTH OF THE REGION. EXPECT OCCASIONAL DRIZZLE
OVERNIGHT AT THE COAST AND FOR THE NORTHERN INTERIOR TAF SITES.
EXPECT IFR OR LOWER CONDITIONS TO REMAIN AT THE COAST THROUGH MON.
OVER THE INTERIOR...EXPECT MVFR CIGS TO PERSIST THROUGH MOST OF
MON MORNING OVER THE NORTH...POTENTIALLY LOWERING TO IFR AT TIMES.
FURTHER SOUTH...CLOUDS MAY SCATTERED OVERNIGHT...ALLOWING PATCHY
IFR STRATUS OR FOG TO FORM. CONDITIONS SHOULD IMPROVE TO VFR FOR
THE INTERIOR BY AROUND MIDDAY. STRONG WLY 850 MB FLOW WILL
MAINTAIN IFR OR WORSE CONDITIONS FOR THE HIGHER TERRAIN THROUGH
TONIGHT.
KPDX AND APPROACHES...LOW-END MVFR CIGS AROUND 1500 FT EXPECTED TO
PERSIST THROUGH MON MORNING. THERE IS A CHANCE THAT CONDITIONS
WILL DETERIORATE TO IFR LATE TONIGHT. A GRADUAL IMPROVEMENT TO
LOW- END VFR BY MIDDAY MON. PYLE
&&
.MARINE...SOUTHWEST WINDS DROPPED BELOW 20 KT THIS AFTERNOON.
HOWEVER...THE FCST MODELS SUGGEST THAT WIND SPEEDS WILL PICK UP
THROUGH THE NEXT FEW HOURS. EXPECT WINDS OF 20 TO 25 KT OVERNIGHT
THROUGH MON AFTERNOON. A SMALL CRAFT ADVISORY FOR WINDS IS IN
EFFECT FOR ALL OF THE WATERS. EXPECT WINDS TO DROP OFF OVER THE
CENTRAL OREGON WATERS LATER MON...BUT SMALL CRAFT ADVISORY WINDS
MAY END UP CONTINUING OVER THE NORTHERN WATERS INTO EARLY TUE. THE
NEXT SIGNIFICANT SYSTEM REACHES THE WATERS LATE WED. GFS AND ECMWF
CONTINUE TO EXHIBIT DIFFERENCES. FAVORED THE ECMWF BUT WITH
SLIGHTLY STRONGER WIND SPEEDS. POTENTIAL EXISTS FOR LOW-END GALE
GUSTS WED NIGHT. ANOTHER STRONG SYSTEM IS MODELED FOR FRI...WHICH
COULD BRING MORE SOLID GALES. HAVE INDICATED GUSTS TO 40 KT OVER
THE OUTER WATERS.
SEAS HAVE NOW DROPPED BELOW 10 FT...SO HAVE DROPPED THE SMALL
CRAFT ADVISORY FOR SEAS. SEAS LIKELY TO BE JUST UNDER 10 FT
THROUGH MON...BUT THEN EXCEED 10 FT MON EVENING. LATEST ENP RUN
HAS SEAS INCREASING TO NEAR 15 FT AROUND MID-WEEK. PYLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST TUESDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR WINDS FROM MIDNIGHT TONIGHT TO 6 PM PST
MONDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR
OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
MIDNIGHT PST TONIGHT.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 8 AM TO
NOON PST MONDAY.
&&
$$
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 MEMPHIS TN
326 AM CST MON FEB 15 2016
.DISCUSSION...
SKIES ARE CLOUDY ACROSS MUCH OF THE FORECAST AREA EARLY THIS
MORNING WITH TEMPERATURES RANGING FROM THE LOWER 30S TO LOWER 50S.
RAIN IS CURRENTLY FALLING OVER PORTIONS OF EAST ARKANSAS...WEST
TENNESSEE AND NORTH MISSISSIPPI. A FEW LOCATIONS HAVE TEMPERATURES
BELOW FREEZING BUT HAVE NO PRECIPITATION AT THIS TIME SO HAVE
ALLOWED WINTER WEATHER ADVISORY TO EXPIRE AT 300 AM.
A WEAK COLD FRONT CURRENTLY EXTENDS ACROSS NORTH MISSISSIPPI
THROUGH EXTREME SOUTHERN ARKANSAS AND INTO NORTH CENTRAL TEXAS.
THIS FRONT WILL DROP SLOWLY SOUTH TODAY. LOW PRESSURE WILL MOVE
ALONG THE FRONT TODAY WHICH WILL PRODUCE MORE SHOWERS FOR MUCH OF
THE FORECAST AREA. TEMPERATURES WILL BE MAINLY BELOW NORMAL LEVELS
TODAY WITH HIGHS FROM THE MID 40S TO MID 50S. AS THE COLD FRONT
MOVES AWAY FROM THE FORECAST AREA TONIGHT RAIN WILL BE ENDING
DURING THE EVENING HOURS. THE AIR BEHIND THIS COLD FRONT IS NOT
PARTICULARLY COLD SO TEMPERATURES TONIGHT WILL BE CLOSE TO NORMAL
LEVELS WITH LOWS TUESDAY MORNING IN THE MID 30S TO LOWER 40S.
ANOTHER COLD FRONT WILL DROP THROUGH THE CENTRAL PLAINS AND INTO
THE FORECAST AREA ON TUESDAY. THIS WILL MEAN ANOTHER CHANCE OF
RAIN FOR THE REGION. BEFORE THE FRONT MOVES THROUGH TEMPERATURES
WILL WARM UP SOME WITH HIGHS FROM MID 50S TO LOWER 60S. THIS COLD
FRONT WILL BE OUT OF THE REGION TUESDAY NIGHT BRINGING AN END TO
THE RAIN. TEMPERATURES WILL BE A LITTLE COOLER BEHIND THE FRONT
FOR TUESDAY NIGHT AND WEDNESDAY BUT WILL REMAIN ABOVE NORMAL
LEVELS.
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER FOR WEDNESDAY AND
THURSDAY BRINGING A PERIOD OF DRY WEATHER. TEMPERATURES WILL BE
ABOUT THE SAME ON WEDNESDAY AS THEY WILL BE TUESDAY WITH HIGHS
MAINLY IN THE 50S. MUCH WARMER AIR WILL MOVE INTO THE REGION FOR
THURSDAY WITH HIGHS MAINLY IN THE 60S.
MODELS ARE NOT IN AGREEMENT WITH THE TIMING OF THE NEXT COLD FRONT
WHICH SHOULD MAKE ITS WAY INTO THE REGION BY SATURDAY NIGHT. HAVE
GONE WITH A DRY FORECAST FOR FRIDAY THROUGH SATURDAY WITH A CHANCE
OF RAIN STARTING SATURDAY NIGHT. TEMPERATURES WILL REMAIN ABOVE
NORMAL DURING THIS PERIOD. ONCE THIS FRONT MOVES INTO THE REGION
IT IS EXPECTED TO STALL OUT SO THE THREAT OF RAIN WILL CONTINUE
INTO SUNDAY AS WELL.
ARS
&&
.AVIATION...
06Z TAFS
00Z NAM AND 02Z HRRR BRING POST FRONTAL IFR TO TO MEM AND MKL
DURING THE NIGHT...WHILE ISOLATED TSRA WILL LIKELY LIFT EAST
ACROSS NORTH MS NEAR THE SFC FRONT...DURING THE OVERNIGHT. WILL
BE CLOSE AS TO WHETHER THIS ACTIVITY GETS TO WITHIN 25 MILES OF
MEM...BUT HAVE INCLUDED A VCTS INTO MEM BEGINNING AT 09Z.
OTHERWISE...TSRA WILL BE POSSIBLE AT TUP FROM LATE MORNING INTO
MIDDLE AFTERNOON. FOLLOWING THE EXIT OF THE SYSTEM LATE MONDAY
AFTERNOON...RESIDUAL LOW LEVEL MOISTURE...RECENT RAINFALL AND
LIGHT WINDS WILL PRESENT A RISK OF LOW CLOUDS AND GROUND FOG
MONDAY EVENING.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1141 PM CST SUN FEB 14 2016
.UPDATE...
UPDATED FOR 06Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 915 PM CST SUN FEB 14 2016/
UPDATE...
A FEW CHANGES HAVE BEEN MADE TO THE FORECAST THIS EVENING OUTLINED
BELOW. AN IMPRESSIVE THERMAL GRADIENT HAS ESTABLISHED ITSELF
ROUGHLY ALONG THE I40 CORRIDOR THIS EVENING WITH FREEZING RAIN
CONTINUING ACROSS PORTIONS OF NORTHEAST AR/MO BOOTHEEL/NORTHWEST
TN. NO CHANGES HAVE BEEN MADE TO THE CURRENT ADVISORY WHICH IS IN
EFFECT THROUGH MIDNIGHT.
FURTHER SOUTH...VERY STRONG ISENTROPIC ASCENT WILL DEVELOP UP THE
SHARPLY SLOPED FRONTAL ZONE AS A STRENGTHENING LOW LEVEL JET
PERSISTS THROUGH MONDAY MORNING. BOTH GLOBAL AND HI-RES GUIDANCE
SUGGESTS A NARROW BUT HEAVY AXIS OF PRECIP DEVELOPING THROUGH MUCH
OF SUNDAY NIGHT...LASTING THROUGH MONDAY MORNING. IN FACT...THE
GFS DEPICTS TOTALS BETWEEN 4-5 INCHES. THIS SOLUTION IS CLEARLY AN
OUTLIER...BUT RAINFALL TOTALS BETWEEN 2-3 INCHES ARE POSSIBLE
SOUTH OF I40. FORECAST SOUNDINGS ALSO SHOW ELEVATED INSTABILITY
PERSISTING ABOVE THE SURFACE FRONTAL BOUNDARY WHICH SHOULD BE
SUFFICIENT TO GENERATE THUNDER ALONG AND SOUTH OF I40 AFTER
MIDNIGHT.
TVT
PREV DISCUSSION... /ISSUED 551 PM CST SUN FEB 14 2016/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 343 PM CST SUN FEB 14 2016/
DISCUSSION...
AT 3PM... SURFACE ANALYSIS PLACES A 1036 MB HIGH OVER NEW YORK
STATE WITH SOUTHERLY SURFACE FLOW OVER MUCH OF THE MIDSOUTH AS A
RESULT. A WEAK SURFACE BOUNDARY STRETCHES FROM NEAR HICKORY RIDGE
ARKANSAS NORTHEAST TO NEAR PARIS TENNESSEE. WINDS TO THE NORTH OF
THIS FEATURE HAVE BECOME NORTHERLY AGAIN AND TEMPERATURES HAVE
DROPPED A DEGREE OR SO AT SOME LOCALES AS A RESULT. PRECIPITATION
IS ONGOING IN THE VICINITY OF THE FEATURE...MUCH OF WHICH COULD BE
FREEZING DRIZZLE AT THE SURFACE WITH TEMPERATURES ACROSS EXTREME
NORTH WEST TENNESSEE...THE MISSOURI BOOTHEEL...AND NORTHEAST
ARKANSAS BELOW FREEZING.
PRECIPITATION IS EXPECTED TO BE FOCUSED ALONG THE SURFACE BOUNDARY
THIS EVENING AND TONIGHT AS IT SLOWLY MOVES SOUTHEAST. CONCERN FOR
CONTINUED FREEZING RAIN OR FREEZING DRIZZLE HAS PROMPTED THE
CONTINUATION OF THE WINTER WEATHER ADVISORY THROUGH MIDNIGHT WHEN
TEMPERATURES IN THE ADVISORY AREA ARE EXPECTED TO GRADUALLY CLIMB.
WHATEVER PRECIPITATION IS LEFT IN THOSE AREAS AT THAT TIME WOULD
CHANGE TO RAIN...ALTHOUGH MODELS INDICATE DRY CONDITIONS BUILDING
INTO THESE LOCATIONS BY MIDNIGHT.
A DEVELOPING LOW CURRENTLY OVER SOUTHERN OKLAHOMA WILL GRADUALLY
MOVE ALONG THE SURFACE BOUNDARY OVERNIGHT AND INTO MONDAY AS A
WAVE AMPLIFIES ALOFT...INDUCING RAINFALL OVER MUCH OF THE
MIDSOUTH. MODELS MARCH THE DEEPENING LOW OVER NORTH MISSISSIPPI BY
MONDAY AFTERNOON WHICH WILL LEAD TO HEAVIER QPF AMOUNTS BY LATE
MONDAY FOR MANY LOCATIONS ALONG AND SOUTH OF INTERSTATE 40. 1 TO 3
INCHES OF QPF IS POSSIBLE OVER MANY OF THESE AREAS BY EARLY
TUESDAY. ADDITIONALLY...A PORTION OF NORTHEAST MISSISSIPPI WILL
BECOME ENVELOPED IN THE WARM SECTOR OF THE SURFACE LOW WHICH WILL
ALLOW TEMPERATURES TO WARM TO NEAR 60 IN THOSE LOCATIONS...UPPER
40S AND 50S ELSEWHERE...WHILE ALSO CREATING A CHANCE FOR A FEW
THUNDERSTORMS ON MONDAY AFTERNOON WITH VERY LIMITED INSTABILITY
AVAILABLE AT BEST. THE LOW MOVES EAST ON MONDAY NIGHT AS GUIDANCE
SUGGESTS ANOTHER SURFACE LOW MOVES FROM NORTHWEST TO SOUTHEAST IN
THE VICINITY OF THE MIDSOUTH ON TUESDAY. MODELS DIVERGE ON
PLACEMENT OF THIS FEATURE...WITH THE GFS AND NAM WELL EAST OF THE
AREA...SO ONLY INCLUDED POPS FOR NORTHEAST PORTIONS OF THE FA.
TUESDAY HIGHS WILL WARM INTO THE 50S AND 60S.
DRIER AND A TAD COOLER ON WEDNESDAY WITH HIGH PRESSURE BUILDING
INTO THE REGION UNDER MOSTLY NORTHWEST FLOW ALOFT. A WARMING TREND
BEGINS ON THURSDAY AS THE SURFACE HIGH SHIFTS EAST...RETURNING
SOUTHERLY SURFACE FLOW. A RIDGE ALSO BUILDS IN ALOFT WHICH WILL
LEAD TO THURSDAY AND FRIDAY TEMPERATURES IN THE 60S TO NEAR
70...SOME 10 TO 15 DEGREES WARMER THAN NORMAL FOR MID FEBRUARY.
RAIN CHANCES COULD RETURN NEXT WEEKEND WITH A TRAILING COLD FRONT
FROM A LOW CENTERED OVER THE GREAT LAKES REGION MOVING THROUGH
SATURDAY BEFORE A DEVELOPING LOW MOVES EAST INTO THE REGION NEXT
SUNDAY.
ZDM
&&
.AVIATION...
06Z TAFS
00Z NAM AND 02Z HRRR BRING POST FRONTAL IFR TO TO MEM AND MKL
DURING THE NIGHT...WHILE ISOLATED TSRA WILL LIKELY LIFT EAST
ACROSS NORTH MS NEAR THE SFC FRONT...DURING THE OVERNIGHT. WILL
BE CLOSE AS TO WHETHER THIS ACTIVITY GETS TO WITHIN 25 MILES OF
MEM...BUT HAVE INCLUDED A VCTS INTO MEM BEGINNING AT 09Z.
OTHERWISE...TSRA WILL BE POSSIBLE AT TUP FROM LATE MORNING INTO
MIDDLE AFTERNOON. FOLLOWING THE EXIT OF THE SYSTEM LATE MONDAY
AFTERNOON...RESIDUAL LOW LEVEL MOISTURE...RECENT RAINFALL AND
LIGHT WINDS WILL PRESENT A RISK OF LOW CLOUDS AND GROUND FOG
MONDAY EVENING.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR CLAY-GREENE-
LAWRENCE-RANDOLPH.
MO...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR DUNKLIN-
PEMISCOT.
MS...NONE.
TN...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR BENTON TN-
HENRY-LAKE-OBION-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1116 PM CST SUN FEB 14 2016
.DISCUSSION...
INTERESTING EVOLUTION OF WINTER WEATHER EVENT HAS OCCURRED THIS
EVENING AS SURFACE FREEZING LINE HAS SAGGED BACK SOUTHWARD TO NEAR
THE I-40 CORRIDOR. THIS APPEARS TO HAVE BEEN DUE TO A WEAK WAVE
MOVING NORTHEASTWARD ALONG THE INVERTED TROUGH IN PLACE FROM SW TO
NE ACROSS THE CWA. 02Z HRRR AND 00Z NAM INSIST FREEZING LINE WILL
RETURN BACK NORTHWARD THIS EVENING/OVERNIGHT...AND THIS APPEARS TO
BE UNDERWAY AS TEMPERATURES HAVE RISEN INTO THE LOW 30S AT CKV AND
INTO SOUTHERN KY. HOWEVER...LIGHT SLEET/FZRA WILL CONTINUE FOR
ANOTHER HOUR OR TWO FOR THE I-40 CORRIDOR COUNTIES...AND LIKELY
LINGER PAST MIDNIGHT FOR THE KY BORDER COUNTIES WHERE TRAVEL
IMPACTS REMAIN SIGNIFICANT. THUS HAVE EXTENDED THE WWA UNTIL 12Z
FOR THE NORTHWESTERN COUNTIES AS TRAVEL WILL REMAIN HAZARDOUS
THERE THROUGH THE OVERNIGHT HOURS. ALTHOUGH MOST OBS ARE WELL
ABOVE FREEZING IN THE CENTRAL PLATEAU COUNTIES...KEPT THE ADVISORY
GOING FOR PUTNAM/WHITE/CUMBERLAND/VAN BUREN AS SOME AREAS REMAIN
BELOW FREEZING...MAINLY THE HIGHER ELEVATIONS. UPDATED PRODUCTS
OUT SHORTLY.
&&
.AVIATION...
06Z TAF DISCUSSION.
POOR FLYING CONDITIONS NEXT 24 HOURS DUE TO LOW CEILINGS...VISIBILITIES
AND PRECIP. 32 DEGREE ISOTHERM EXTENDS PRETTY MUCH ALONG INTERSTATE
40 WITH SLEET AND FREEZING RAIN ALONG AND NORTH. SHORT RANGE
MODELS SEEM TO BE TOO FAST BY AT LEAST 2 HOURS AND POSSIBLY 3 IN
TAKING FREEZING LINE TO THE KENTUCKY BORDER. SO THAT MEANS SLEET
AND FREEZING RAIN LASTING A LITTLE LONGER OVER NORTHERN MIDDLE
TENNESSEE BEFORE CHANGE OVER TAKES PLACE.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CLAY-
CUMBERLAND-FENTRESS-JACKSON-MACON-MONTGOMERY-OVERTON-PICKETT-
PUTNAM-ROBERTSON-STEWART-SUMNER-VAN BUREN-WHITE.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
402 AM CST MON FEB 15 2016
.SHORT TERM (TODAY THROUGH TUESDAY)...
MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG
AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON
TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE
RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED
TODAY AND TUESDAY.
WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH
PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME
LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER
LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR
LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH-
CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE
FRONT THAT IS NOW LOCATED ALONG A DALLAS TO WACO TO OZONA LINE.
LOW CLOUDS AND AREAS OF FOG WILL OCCUR NOW THROUGH 8-10AM WITH
SOME POCKETS OF DENSE FOG POSSIBLE ALONG WITH DRIZZLE/MIST WHERE
THE FOG/LOW CLOUDS ARE THICKER NEAR THE SURFACE.
THE WEAK BOUNDARY WILL SWEEP THROUGH THE HILL COUNTRY AND AUSTIN BY
7-9AM AND THROUGH SAN ANTONIO BEFORE 11AM. RAPID CLEARING OF CLOUDS
IS EXPECTED BEHIND THE BOUNDARY WITH SUNNY CONDITIONS AND BREEZY
NORTH WINDS EXPECTED THIS AFTERNOON. THE COMBINATION OF WINDS
GUSTING TO NEAR 20-25 MPH AND THE DRIER AIR MOVING IN WILL
PROMOTE ELEVATED FIRE WEATHER CONDITIONS ACROSS THE RIO GRANDE
PLAINS AS RELATIVE HUMIDITY VALUES DIP NEAR TO JUST BELOW 20% THIS
AFTERNOON.
FOR TUESDAY...A SLIGHTLY COOLER MORNING IS EXPECTED GIVEN THE
DRIER AIR AND NEAR CALM WINDS BUT READINGS WILL BE NEAR CLIMATE
NORMALS. EXPECTED CLEAR SKIES WITH PLENTY OF SUN WITH HIGHS
REACHING ABOVE NORMAL INTO THE UPPER 70S AND LOW 80S AREAWIDE.
SOME LOCATIONS IN THE RIO GRANDE PLAINS COULD REACH INTO THE MID
80S.
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
WELL ABOVE NORMAL TEMPERATURES OF 10-15F DEGREES ARE EXPECTED MID TO
LATE WEEK WITH A SLIGHT COOL DOWN INTO THE WEEKEND. DRY
CONDITIONS WILL ALSO REMAIN UNTIL EARLY NEXT WEEK WHERE A MORE
SUBSTANTIAL COLD FRONT AND BETTER RAIN CHANCES COULD OCCUR.
CONUS PATTERN MID TO LATE WEEK WILL FEATURE SURFACE HIGH PRESSURE
OVER THE MID-MS RIVER VALLEY WITH SOUTHEAST LOW-LVL FLOW THAT VEERS
TO THE SOUTHWEST/WEST IN THE MID-LVLS OVER TEXAS. THIS TYPE OF
PATTERN ALONG WITH A BUILDING H5 RIDGE AND H925 TEMPS 23-16C FROM
WEST TO EAST WILL SUPPORT UPPER 70S TO MID 80S. WHILE IT WILL BE
WARM...RECORD TEMPERATURES DO NOT LOOK TO BE IN JEOPARDY AS THOSE
VALUES ARE ALREADY WELL INTO THE 90S. MORNING CLOUDS LOOK TO
RETURN THURSDAY AND FRIDAY BUT QUICK MIX OUTS BY MID MORNING HOURS
TO PARTLY AND MOSTLY SUNNY SKIES WILL OCCUR. SLIGHTLY COOLER H925
AIR WILL PIVOT IN ACROSS THE REGION THIS WEEKEND AS THE H5 RIDGE
BREAKS DOWN AND SOME WEAK IMPULSES MIGRATE OVER THE REGION THAT
WILL CREATE SOME MORE MID-LVL CLOUDS.
GLOBAL LONG RANGE MODELS CONTINUE TO HINT AT IN DECENT ACCORD A MORE
ACTIVE SOUTHERN JET STREAK BRANCH OVER SOUTH TEXAS NEXT SUNDAY-
TUESDAY. THIS ACTIVE BRANCH WILL HELP BUCKLE THE FLOW WITH ENHANCED
TROUGHING THAT, IN CONJUNCTION WITH THE POLAR JET, WILL AID A
STRONGER CANADIAN ORIGINATED FRONT TO APPROACH THE AREA AROUND
MONDAY. THIS STRONGER FRONT AND BETTER DYNAMIC SUPPORT SHOULD ALLOW
FOR BETTER RAIN/TSTORM CHANCES IN THIS TIME FRAME. WILL CONTINUE TO
MONITOR THE EVOLUTION OF THIS SYSTEM AND ITS LIKELY MORE WIDESPREAD
RAIN SIGNAL FOR THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 75 47 81 50 82 / 10 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 43 80 45 81 / 10 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 77 44 81 47 81 / - 0 0 0 0
BURNET MUNI AIRPORT 73 44 79 46 80 / - 0 0 0 0
DEL RIO INTL AIRPORT 80 46 85 51 87 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 73 44 80 46 80 / 10 0 0 0 0
HONDO MUNI AIRPORT 80 42 82 46 83 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 44 79 46 79 / - 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 46 79 47 80 / 10 0 0 0 0
SAN ANTONIO INTL AIRPORT 77 46 80 49 82 / 0 0 0 0 0
STINSON MUNI AIRPORT 79 46 82 48 82 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...ALLEN
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
1017 AM EST MON FEB 15 2016
.DISCUSSION...
...SLIGHT CHANCE FOR STRONG STORMS THIS EVENING/OVERNIGHT...
UPDATE...THE MORNING SOUNDING FROM XMR SHOWS THAT ADDITIONAL
RECOVERY WILL BE REQUIRED FOR BETTER CHCS OF RAIN. AVAILABLE PWAT
FROM SONDE RELEASE TIME WAS STILL ONLY AROUND 0.77 INCHES ALONG WITH
A RESIDUAL CAP JUST ABV H85. BRISK WINDS OF 20 TO 30 KT FROM NEAR
SFC THROUGH 5K FT SHOULD PROVIDE SUITABLE MOISTURE WITH PARTIAL SFC
HEATING HELPING TO STEEPEN UP THE ENVIRONMENTAL LAPSE RATE
UNDERNEATH A COOL H5 TEMP OF -15C. LTST HRRR GUID SHOWS LAND BASED
PCPN DEVELOPMENT AFT 1 PM MAINLY SOUTH OF THE BEACHLINE EXPRESSWAY
TO LAKE OKEE. THE LATE DAY AND OVERNIGHT PERIOD WL REMAIN FAVORED
TIME FOR RAIN CVG ALONG WITH THUNDER CHCS. WL KEEP CURRENT FORECAST
IN PLACE.
TODAY-TONIGHT...(PREV DISC) SHORTWAVE TROUGH DIGGING ACROSS THE
SOUTHERN STATES WILL GENERATE A SURFACE LOW VICINITY OF THE LOWER
MISSISSIPPI VALLEY EARLY TODAY...WHICH WILL GRADUALLY DEEPEN WHILE
LIFTING INTO THE SOUTHERN APPALACHIANS TONIGHT. THIS SYSTEM WILL BE
MOVING RATHER QUICKLY SO MOISTURE RETURN AND INSTABILITY WILL BE
LIMITED. STILL...WITH GOOD LARGE SCALE ASCENT...EXPECT HIGH RAIN
CHANCES PRIMARILY DURING THE OVERNIGHT PERIOD.
THE GFS AND HRRR HAVE BEEN SHOWING SOME CONVECTION DEVELOPING LATE
AFTERNOON/EARLY EVENING FROM BOUNDARY INTERACTIONS. HAVE GONE
WITH 30 PERCENT POPS DURING THE TODAY PERIOD FOR THIS POSSIBILITY...
THEN INCLUDED A SLIGHT CHANCE FOR THUNDERSTORMS THROUGH LATE
EVENING AS DEEPENING TROUGH GETS NEARER. DURING THE OVERNIGHT
PERIOD...MOS POPS INCREASE TO 60-90 PERCENT. DID NOT GO QUITE THAT
HIGH AND HAVE SETTLED ON LIKELY POPS (60-70 PERCENT) WITH A
CONTINUED SLIGHT CHANCE FOR STORMS...EXCEPT 50 PERCENT POPS IN THE
SOUTH.
THE MAIN CONCERN WHEN THUNDER IS IN THE FORECAST THIS TIME OF THE
YEAR WILL BE THE THREAT FOR STRONG OR SEVERE STORMS. WITH SURFACE
DEW POINTS RECOVERING ONLY INTO THE LOWER 60S AND THE PRIMARY
SUPPORT FOR DEEP CONVECTION OCCURRING OVERNIGHT...INSTABILITY
WILL BE LIMITED. ADDITIONALLY...LOW LEVEL WIND FIELDS ONLY
INCREASE TO ABOUT 30-35 KNOTS. BUT IT WILL BE QUITE COLD ALOFT
WITH 500 MB TEMPS AROUND MINUS 15 CELSIUS. WILL HAVE TO WATCH FOR
PRE FRONTAL CONVECTION OVER THE GULF SPREADING INLAND AND HOLDING
TOGETHER SOMEWHAT AS SURFACE WINDS STAY BACKED ENOUGH TO SUSTAIN
LOW LEVEL CONVERGENCE. THE GFS SHOWS 0-1KM HELICITY VALUES 100-200
M2S2 OVERNIGHT SO DO NOT WANT TO RULE OUT A SMALL RISK FOR STORM
ORGANIZATION AND SEVERE WEATHER. THE STORM PREDICTION CENTER DOES
HAVE A MARGINAL RISK FOR ALL OF EAST CENTRAL FLORIDA EXCEPT THE
TREASURE COAST.
&&
.AVIATION...A MOISTENING SOUTHEAST WIND FLOW WILL PRODUCE
CONSIDERABLE STRATOCUMULUS TODAY WITH CEILINGS MAINLY ABOVE 3500
FEET. THERE WILL BE A CHANCE FOR SHOWERS ESPECIALLY LATE IN THE
DAY WITH LOCAL MVFR. AS A STRONG TROUGH ALOFT APPROACHES
TONIGHT...SHOWERS WILL INCREASE IN COVERAGE AND EXPECT A SLIGHT
CHANCE FOR STORMS SO MVFR CONDITIONS WILL BECOME MORE LIKELY AND
LOCAL IFR WILL BE POSSIBLE.
&&
.MARINE...
TODAY-TONIGHT...POOR TO HAZARDOUS CONDITIONS FOR SMALL CRAFT
OPERATION INDICATED. SOUTHEAST WINDS OVER THE WATERS 20 KNOTS WITH
20 TO 25 KTS WELL OFFSHORE AND GUSTY. WINDS WILL VEER MORE TO THE
SOUTH TONIGHT WHILE STAYING AROUND 20 KNOTS. NO CHANGE TO THE
PREVIOUS HEADLINES.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR SEBASTIAN INLET
TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR FLAGLER BEACH
TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
JP/DKW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
622 AM EST MON FEB 15 2016
.SYNOPSIS...
A WARM FRONT WILL EXTEND THROUGH SOUTHERN GEORGIA AND ALONG THE
SOUTH CAROLINA COAST TODAY. ASSOCIATED LOW PRESSURE MOVING INTO
THE LOWER MISSISSIPPI RIVER VALLEY TODAY WILL BE NEAR THE FORECAST
AREA TONIGHT. DRYING WILL OCCUR TUESDAY AS THE LOW LIFTS NORTHWARD
AND FARTHER AWAY FROM THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...COLD HIGH PRESSURE WILL BE WEDGED INTO THE FORECAST AREA
WITH A WARM FRONT NEAR THE COAST AND IN SOUTHERN GEORGIA. THE
FRONT WILL LIFT NORTHWARD SLOWLY. THE NAM SURFACE-BASED LI
PATTERN MAINTAINS THE WEDGE PATTERN HERE THROUGH TODAY. STRONG
ISENTROPIC LIFT SUPPORTS PRECIPITATION BUT IT SHOULD REMAIN
LIMITED BECAUSE OF SHALLOW MOISTURE AND LITTLE UPPER-LEVEL LIFT.
THE NAM...GFS...ECMWF...AND ALL SREF MEMBERS INDICATE LITTLE
PRECIPITATION...0.01 OF AN INCH THIS MORNING...AND 0.01 TO 0.1 OF
AN INCH THIS AFTERNOON. THE HRRR HAS A FEW PATCHES OF LIGHT
PRECIPITATIONS THIS MORNING WITH A LITTLE MORE COVERAGE THIS
AFTERNOON. SURFACE WET BULB TEMPERATURES AND MODEL FORECAST
SOUNDINGS SUPPORT A PREDOMINATE PRECIPITATION TYPE OF FREEZING
RAIN OR FREEZING DRIZZLE BECOMING ALL LIQUID FROM SOUTH TO NORTH.
THE TIMING SUPPORTS MORE OF A THREAT IN THE NORTH AND WE HAVE
POSTED A FREEZING RAIN ADVISORY IN THE NORTH SECTION. THE THREAT
OF FREEZING RAIN WILL LIKELY CONTINUE IN THE EXTREME NORTH PART
UNTIL ABOUT 100 PM BASED ON THE SREF MEAN TEMPERATURE. IT IS
POSSIBLE THE COLDER AIR WILL REMAIN IN PLACE LONGER AS INDICATED
BY THE IN-HOUSE WEDGE SCHEME. HOWEVER...IT IS BASED ON THE NAM
WHICH AS HAD A COLD BIAS LATELY. GIVEN THE VERY LOW QPF WE EXPECT
JUST TRACE ICE ACCUMULATIONS BUT IT TAKES LITTLE ICE TO CAUSE
ISSUES. THE THREAT SHOULD BE MAINLY ON ELEVATED SURFACES SUCH AS
BRIDGES AND OVERPASSES.
TONIGHT...TEMPERATURES SHOULD BE ABOVE FREEZING THROUGHOUT THE
AREA AS WARMING OCCURS AHEAD OF APPROACHING LOW PRESSURE. THE
NOCTURNAL LOW WILL OCCUR AT SUNSET. CONVERGENCE ASSOCIATED WITH
THE LOW...A STRONG H85 JET AND H5 SHORTWAVE TROUGH WILL RESULT IN
SHOWERS TONIGHT. THE GUIDANCE WAS CONSISTENT WITH CATEGORICAL POPS.
THE NAM...GFS...ECMWF...AND SREF MEAN SUPPORT RAINFALL OF 0.5 TO
1 INCH. THE MODELS DEPICT A NEGATIVE TILT UPPER TROUGH. STRONG
UPPER DIVERGENCE AND THE LOW-LEVEL JET MAY RESULT IN ENOUGH
INSTABILITY FOR A FEW ELEVATED THUNDERSTORMS. THE NAM INDICATES
CROSS TOTALS IN THE MID 20S. DESPITE THE STRONG SHEAR THE THREAT
OF SEVERE THUNDERSTORMS SHOULD REMAIN LOW BECAUSE OF A LACK OF
SURFACE-BASED INSTABILITY AS INDICATED BY THE NAM LI FORECAST.
IT WILL LIKELY BECOME BREEZY TONIGHT WITH INCREASED MIXING NEAR
THE COLD FRONT. WE WILL LIKELY NEED A LAKE WIND ADVISORY.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
DRYING SHOULD OCCUR TUESDAY BEHIND THE COLD FRONT AND MAIN MID-
LEVEL SHORTWAVE TROUGH. MIXING AND THE PRESSURE GRADIENT
ASSOCIATED WITH LOW PRESSURE LIFTING NORTH OF THE AREA SHOULD
RESULT IN BREEZY CONDITIONS. A LAKE WIND ADVISORY WILL LIKELY BE
NEEDED.
THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT
ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF
THE FORECAST AREA TUESDAY NIGHT. A PRESSURE RIDGE WEST OF THE
AREA SHOULD MAINTAIN DRY CONDITIONS WEDNESDAY.
USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST TUESDAY
THROUGH WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE GFS AND ECMWF DISPLAY DRY RIDGING DOMINATING THROUGH THE
MEDIUM-RANGE PERIOD EXCEPT MOISTURE DOES APPEAR TO INCREASE SATURDAY
OR SUNDAY ASSOCIATED A DEVELOPING WARM FRONT. THE GFS...ECMWF...
AND EKD MOS HAVE POPS LESS THAN 10 PERCENT THROUGH FRIDAY...AND 5
TO 20 PERCENT SATURDAY AND SUNDAY. THE MOS HAS NEAR OR ABOVE
NORMAL TEMPERATURES DURING THE PERIOD.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF THE
TAF PERIOD.
MVFR CIGS ACROSS THE TAF SITES EARLY THIS MORNING WITH EASTERLY
WINDS 5 TO 10 KNOTS. GFS LAMP INDICATING MOSTLY MVFR CONDITIONS
TODAY LOWERING TO IFR BY THIS EVENING.
GIVEN LATEST NAM MODEL GUIDANCE AND CAE VWP...WILL CONTINUE MENTION
LLWS AT ALL TAF SITES UNTIL AROUND 14Z WITH 30 KTS AOB 2000 FT
POSSIBLE. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND
CLOUDS.
MOISTURE AND ISENTROPIC LIFT WILL CONTINUE TO INCREASE ACROSS THE
AREA EARLY THIS MORNING AS WEDGE CONDITIONS DEVELOP. AT THIS
TIME...THINK THE THREAT OF FREEZING RAIN AT ANY OF THE TAF SITES
IS LOW. SOME LIGHT RAIN IN THE VCNTY OF OGB EARLY THIS
MORNING...OTHERWISE HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW
CONFIDENCE IN TIMING. RAIN WILL INCREASE ACROSS THE AREA THIS
AFTERNOON SO HAVE MENTIONED IN THE TAFS.
SURFACE WINDS WILL BE MAINLY FROM THE NORTHEAST AND EAST GENERALLY
LESS THAN 10 KNOTS FOR MUCH OF TODAY...BUT WILL SHIFT TO SOUTH AND
INCREASE TO AROUND 10-15 KNOTS WITH GUSTS OVER 20 KNOTS TONIGHT.
EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY
NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM
CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT
INTO TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
SCZ015-016.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
512 AM CST MON FEB 15 2016
.SHORT TERM...(Today)
ISSUED AT 314 AM CST MON FEB 15 2016
08z/2am radar imagery continues to indicate patchy freezing drizzle
across central Illinois: however, the areal coverage and intensity
has decreased markedly from earlier in the evening. As light
southerly winds flow over the cold/snow-covered ground, expect fog
and perhaps some drizzle to persist through the morning. Current
visibilities are mostly in the 2-5 mile range, but HRRR suggests the
potential for even lower visbys as WAA continues and low overcast
lifts. Have seen a few reports of 1/4 mile visbys upstream across
central Missouri where clouds have temporarily cleared and expect
the fog to thicken/spread northeastward into central Illinois over
the next few hours. Will need to carefully monitor trends, as a
Dense Fog Advisory could be needed if HRRR verifies. For now, will
just mention areas of fog in the forecast through midday. A weak
short-wave trough evident on latest water vapor imagery over eastern
Nebraska will pass to the W/SW of the area today. A small area of
light snow associated with this feature over southwest Iowa will
spread across northern Missouri and may approach the far SW CWA
toward midday: however, all high-res models show the precip
dissipating before arriving. Have therefore gone with a dry
forecast. Despite continued southerly flow, fog and extensive cloud
cover will keep afternoon high temperatures in the middle to upper
30s.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 314 AM CST MON FEB 15 2016
The next fast-moving storm system embedded within the prevailing
northwesterly flow aloft will arrive late tonight into Tuesday,
bringing another period of wintry precip to central Illinois. 00z
Feb 15 models have all trended south with the track of this system,
with the NAM being the furthest north and the GEM the furthest
south. Have rejected these two solutions in favor of the middle
of the road GFS, which takes the 500mb vort max from northern
Missouri 12z Tue to far southern Illinois by 18z Tue. Given this
particular track, the heaviest precip will be focused across the
central/southern CWA. Have therefore reduced PoPs into the
chance category along/north of I-74...while maintaining likely
further south across the remainder of the area. Another
consequence of a further south track is a slightly colder thermal
profile. GFS forecast soundings are generally cold enough for
snow initially as the max temp in the elevated warm layer only
reaches about 1C. As a result, am expecting snow Tuesday
morning, gradually transitioning to a rain/snow mix by afternoon
as surface temps rise into the middle to upper 30s. Due to the
southward track shift, relatively light precip, and marginal
temps...snow accumulations are expected to remain minor. Will
see a band of around 1 inch along/southwest of a Canton...to
Decatur...to Marshall line...with less than one half inch north of
I-74.
Another weak short-wave will pass through the region on Wednesday:
however, this feature will be moisture-starved and will produce
little more than some cloud cover. Once this wave exits, upper
heights will begin to rise in earnest in response to a major
system coming onshore along the Pacific Coast. Downstream
ridging across the central and eastern CONUS will allow a
pronounced warming trend to occur by the end of the week. Models
have been consistently advertising temps reaching the upper 40s
and lower 50s by Thursday, then climbing into the upper 50s and
lower 60s on Friday. A weak cold front is still progged to pass
through Illinois on Friday, but with only limited moisture to work
with, will only mention slight chance for showers with FROPA.
After that, temps cool a bit over the weekend, but remain above
normal in the 50s for both Saturday and Sunday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 510 AM CST MON FEB 15 2016
IFR to VLIFR conditions in low clouds and vsbys expected through
at least 16z before conditions slowly improve into the afternoon
hours. Widespread IFR and LIFR conditions prevailed early this
morning due to high moisuture levels in the low levels of the
atmosphere. Weak high pressure will push across the area today
with forecast soundings indicating a low level inversion in
place effectively trapping the moisture through early this
afternoon. Will start to take the cigs up above 1000 feet after
16-18z but confidence on that occurring is low at this particular
time. Latest short term guidance suggests the lowest vsbys will be
along and especially south of I-72 which should include SPI and
DEC. However, experience has shown that with these light southerly
flow regimes, coupled with a fresh snow cover, BMI has a tendency
to stay rather low with the cigs and vsbys and is slow to recover.
Will trend in that direction thru at least the morning hours.
IFR with some low MVFR cigs expected this evening and overnight
with the next weather system moving in after 08z, and affecting
mainly the SPI TAF. At this point, will include a VCSH with a
threat for some light snow developing before dawn. Surface winds
will not be much of a factor through tonight with a light
southerly to southwesterly flow today with speeds of less than
10 kts, becoming light south to southeast late tonight.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
541 AM CST MON FEB 15 2016
.UPDATE...
Issued at 542 AM CST MON FEB 15 2016
The AVIATION section has been updated for the 12Z TAF issuance.
&&
.SHORT TERM...(Today through Wednesday)
Issued at 255 AM CST MON FEB 15 2016
Scattered light showers continue to stream northeast just clipping
southeastern Todd county Kentucky, but based on the KCKV and KBWG
METARs this area should be just above freezing. Will therefore
let the Winter Weather Advisory expire as scheduled at 3 AM.
Elsewhere across the forecast area, most observation sites have
visibilities between 1 and 3 miles with light fog, and a few
patches of very light freezing drizzle. Weak, drizzly echoes on
radar at Midnight have mostly dried up, so doubt there will be
much, if any, additional icing this morning. However, will re-
issue an SPS mainly to highlight slick driving conditions through
the morning commute.
The 00Z WRF and most recent HRRR runs keep the shower activity
along the TN border through the morning, and then lift it back up
over more of west Kentucky this afternoon before pushing east of
the area early this evening. Given this timing, temperatures
should be above freezing, so there should be no wintry concerns
after the sun gets sufficiently high in the sky this morning.
The 00Z models bring a compact, intense upper low into the base of
the upper trough over the region on Tuesday. The 00Z consensus
keeps any QPF northwest of the area through daybreak, but we will
have to watch for the potential for either freezing rain or snow
with the onset of precipitation in the morning. Model soundings
across the northeast show a warm layer only near the surface, so
it is conceivable that we will have to monitor for snow through
the day as this system passes. Temperatures should be above
freezing, so accumulations will be hard to come by even if the
snow reaches the ground. This system should exit to the east at or
shortly after 00Z Wednesday.
Yet another upper-level disturbance will dive southeast into our
region for Wednesday, as we continue to be heavily influenced by
cyclonic flow aloft. The models are not generating any
precipitation with this activity, but it should keep most of the
area rather cloudy.
.LONG TERM...(Wednesday Night through Sunday)
Issued at 255 AM CST MON FEB 15 2016
By Wednesday into Thursday, we will finally be seeing a shift in the
upper level pattern, as an upper level ridge builds overhead. As
this occurs, we will see quiet weather along with a decent warmup,
that has been advertised for quite a while now. Warm air advection
will begin in earnest Wednesday night and the entire area will see
850mb temps back above zero by late Thursday morning or afternoon.
We should see highs on Thursday well into the 50s per the latest
guidance, 2m temps and soundings. We should see 60s by Friday with
our far western counties in SEMO maybe touching or getting close to
70 degrees. In fact, even warmer weather will only be a state away,
as newest guidance indicating highs around 80 in northeast Oklahoma.
Hard to imagine when you`re currently only sitting at 31 degrees.
Meanwhile, in the northern Plains, an upper level shortwave will be
moving eastward into the Great Lakes Thursday night into Friday. As
this occurs, a weak front at the surface will be moving into our
area. Moisture still appears to be rather scant but the GFS still
tries to eek out some QPF. Whatever does fall, if anything, will be
light. But since POPS have already been taken out, will continue
with that idea and leave it dry, but will have to keep watching, as
the GFS ensembles continue to indicate a few hundredths of QPF with
the FROPA.
The front dives south but only makes into the Gulf Coast State
before stalling out. Models indicate that the front will lift back
north toward the area as early as Saturday night. However, Saturday
should be a dry day with temperatures remaining in the 60s. Another
weak frontal boundary will develop to our west and will move through
on Sunday, which means we will continue with the chance for rain.
The front should be exiting the area sometime on Sunday night. Could
even see some isolated thunderstorms on Saturday night into Sunday
as some of the parameters are hinting at it.
&&
.AVIATION...
Issued at 542 AM CST MON FEB 15 2016
The main concern for the TAFs this morning is how long to hold
onto the LIFR ceilings that currently cover all sites? Freezing fog
has also reduced visibilities to IFR or lower levels, and this
should improve in the next 2 to 3 hours. At KPAH and KCGI figure
that ceilings will lift late this morning and eventually scatter
out early this afternoon. The other sites may see IFR ceilings
linger through the entire forecast period. Winds will be light
through the period. A thick layer of clouds based at 10-15kft
should overspread the area this afternoon, and this may help get
rid of the low clouds.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...CW
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
728 AM CST MON FEB 15 2016
...SOUNDING DISCUSSION...
THE MORNING SURFACE TEMPERATURE INVERSION UP TO 1500 FEET IS THE
ONLY SUBSTANTIAL STABLE LAYER ON THIS MORNING`S SOUNDING. WITH
GOOD BOUNDARY LAYER MIXING...THIS LAYER WILL EVENTUALLY BE REMOVED
AND SHOULD ALLOW FOR MORE SURFACE BASED STORMS. INSTABILITY AS
MEASURED BY MLCAPE IS AROUND 600 J/KG WITH MUCAPE AROUND 1050 J/KG
AND LAPSE RATES ARE MODEST AROUND 6.5 TO 7.0 C/KM ABOVE THE
INVERSION. LOW LEVEL WIND SHEAR IS ALREADY GOOD WITH BOTH
DIRECTIONAL AND SPEED SHEAR PRESENT WITH THE 1KM WINDS FROM THE
SOUTH AT 35 KNOTS AND 6KM WINDS FROM THE WEST AT 45 KNOTS. SRH
0-1KM IS OVER 300 M2/S2 AND 0-3KM IS AROUND 380 M2/S2. THE LAST
TWO STATEMENTS ARE SUPPORTIVE OF ORGANIZED STORMS AND ROTATING
UPDRAFTS. A HAIL THREAT ALSO EXISTS WITH THE FREEZING LEVEL AROUND
9250 FEET AND THE WET BULB ZERO HEIGHT AROUND 8200 FEET. THE
POTENTIAL FOR STRONG DOWNBURST WINDS IS NOT AS HIGH AT THIS TIME
WITH A DOWNDRAFT CAPE AROUND 700 J/KG. OVERALL MEAN STORM MOTION
IS FROM 235 /SOUTHWEST/ AT 36 KNOTS. A PEAK WIND SPEED OF 130
KNOTS AT 40000 FEET WAS OBSERVED AS WE ARE CURRENTLY ON THE
NORTHERN SIDE OF A JET STREAK OVER THE NORTHERN GULF OF MEXICO.
ANOTHER OPPORTUNITY TO EVALUATE THE PRE-STORM ENVIRONMENT WILL
OCCUR AS SPC HAS REQUESTED A SPECIAL RELEASE AROUND 18Z.
12Z BALLOON INFO: A SUCCESSFUL FLIGHT REACHING 20 MILES ABOVE THE
GROUND AFTER 103 MINUTES OF ASCENT. THE BALLOON TRAVELED 67 MILES
DOWNRANGE FROM THE OFFICE.
ANSORGE
&&
.PREV DISCUSSION... /ISSUED 345 AM CST MON FEB 15 2016/
SHORT TERM...
THE NEXT 18 HOURS WILL SEE THE MOST ACTIVE WEATHER EXPECTED FOR
THE REMAINDER OF THE ENTIRE WEEK. A STRONG UPPER LEVEL TROUGH IS
CURRENTLY DIGGING INTO THE SOUTHERN PLAINS AND TEXAS. THIS TROUGH
WILL SLIDE THROUGH THE LOWER MISSISSIPPI VALLEY TODAY AND SHOULD
BE WELL EAST OF THE AREA BY LATE THIS EVENING AND TONIGHT. A
INCREASINGLY WARM AND BUOYANT AIRMASS HAS ADVECTED INTO THE AREA
TONIGHT...WITH TEMPERATURES ACTUALLY WARMING IN MANY SPOTS. THIS
WARM AND BUOYANT AIRMASS WILL INTERACT WITH THE RAPIDLY INCREASING
OMEGA AND RESULTANT LIFT OVERSPREADING THE REGION TO PRODUCE
SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY.
AN INITIAL BAND OF CONVECTION THAT IS CURRENTLY FORMING OVER THE
NORTHWEST PARTS OF THE CWA IS ASSOCIATED WITH A HIGHLY DIFLUENT
FLOW REGIME ALOFT AND A FAVORABLE JET DYNAMICS ASSOCIATED WITH A
100+ KNOT JET STREAK CURRENTLY SLIDING ACROSS THE GULF SOUTH. THIS
BAND OF CONVECTION WILL CONTINUE TO MOVE ACROSS THE NORTHERN HALF
OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS. SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED. A FEW OF THE
STORMS COULD BE STRONG...BUT CONDITIONS DO NOT QUITE LOOK PRIMED
FOR SEVERE CONVECTION THROUGH AT LEAST MID-MORNING AS CAPE WILL
BE SOMEWHAT LIMITED.
HEADING INTO THE LATE MORNING AND AFTERNOON HOURS...ANOTHER BAND
OF CONVECTION SHOULD PUSH THROUGH THE FORECAST AREA. THIS BAND OF
CONVECTION SHOULD FORM ALONG AND JUST AHEAD OF A DRY LINE WHICH IS
CURRENTLY FORMING OVER CENTRAL TEXAS. THE DRY LINE SHOULD QUICKLY
RACE TO THE EAST AT AROUND THE SAME SPEED AS THE PARENT UPPER
LEVEL TROUGH AXIS...AND SHOULD BE MOVING INTO THE ATCHAFALAYA
BASIN SOMETIME AROUND NOON BASED ON THE LATEST HRRR GUIDANCE. IT
LOOKS LIKE THE STRONGEST FORCING AND GREATEST POTENTIAL FOR
CONVECTIVE DEVELOPMENT WILL GENERALLY BE ALONG AND NORTH OF THE
I-10 CORRIDOR...AND HAVE THE HIGHEST POPS IN THIS AREA. DYNAMIC
FORCING SHOULD BE SLIGHTLY WEAKER SOUTH OF I-10...AND ONLY HAVE
CHANCE TO LIKELY POPS FOR THESE AREAS. THE RAIN THREAT SHOULD
QUICKLY DIMINISH BY THIS EVENING AS THE DRY LINE PUSHES INTO
ALABAMA AND FLORIDA AND STRONG DRY AIR ADVECTION AND SUBSIDENCE
OVERTAKES THE AREA.
THE SEVERE THREAT SHOULD ALSO BE GREATEST NORTH OF THE I-10
CORRIDOR...WHERE SPEED SHEAR...DIRECTIONAL SHEAR...AND MLCAPE
VALUES ARE MAXIMIZED. LAPSE RATES WILL BE QUITE STEEP...AND A LOW
WET BULB ZERO HEIGHT OF ONLY 8200 FEET WILL BE FAVORABLE FOR SOME
HAIL FORMATION IN THE STRONGEST STORMS. HELICITY VALUES OF 250
M2/S2 OR HIGHER CAN BE EXPECTED THIS AFTERNOON...SO ANY SUSTAINED
CONVECTION SHOULD BEGIN TO ROTATE AND TAKE ON SUPERCELL
CHARACTERISTICS. THUS...A RISK OF A FEW TORNADOES FORMING WILL
ALSO BE PRESENT THIS AFTERNOON AND EVENING.
THE ENTIRE AREA SHOULD MOSTLY CLEAR SKIES AND DRY WEATHER IN PLACE
BY TOMORROW MORNING...AS DEEP LAYER NORTHWEST FLOW ALOFT AND A
STRONG SURFACE RIDGE OVERTAKE THE GULF SOUTH. THIS SAME GENERAL
PATTERN SHOULD PERSIST INTO WEDNESDAY AS WELL. NOT MUCH IN THE WAY
OF COLD AIR ADVECTION IS EXPECTED WITH THIS RIDGE OF HIGH
PRESSURE...SO TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE
AVERAGE IN THE 60S AND LOWER 70S BOTH DAYS. OVERNIGHT LOWS WILL
COOL INTO THE 40S AND LOWER 50S BOTH NIGHTS.
LONG TERM...
HEADING INTO THE LATTER HALF OF THE WEEK...DEEP LAYER RIDGING WILL
DEVELOP OVER THE AREA...AS A STRONG UPPER LEVEL HIGH MOVES IN FROM
THE SOUTHERN PLAINS AND BECOMES CENTERED OVER THE GULF SOUTH.
SINKING AIR THROUGHOUT THE ATMOSPHERIC COLUMN...ALONG WITH A
RETURN TO ONSHORE FLOW WILL ALLOW TEMPERATURES TO WARM EVEN
FURTHER. HIGHS WILL EASILY CLIMB INTO THE MIDDLE TO UPPER 70S
THURSDAY THROUGH SUNDAY...AND OVERNIGHT LOWS SHOULD ONLY DIP INTO
THE 50S FOR MOST LOCATIONS. CONDITIONS MAY BE FAVORABLE FOR
ADVECTION FOG TO DEVELOP AS DEWPOINTS RISE INTO THE UPPER 50S AND
LOWER 60S. THE BIGGEST CAVEAT WILL BE JUST HOW STRONG WINDS ARE
DURING THE OVERNIGHT HOURS. IF WINDS FALL TO AROUND 5 TO 10
MPH...ADVECTION FOG COULD BE VERY LIKELY DURING THIS PERIOD. HAVE
NOT INCLUDED A MENTION OF FOG IN THE FORECAST YET...DUE TO THE
UNCERTAINTY IN PLACE.
AVIATION...
MOST LOCATIONS ARE VFR WITH CIGS AT OR ABOVE SCT-BKN040...EXCEPT
OVC010 AT KMCB. CONVECTION DEVELOPING STEADILY FROM KMCB TO KLFT
WITH ANOTHER SURGE OF SHOWERS MOVING INTO KBTR. CIGS SHOULD LOWER TO
MVFR LEVELS WITH CONVECTION THIS MORNING...THEN BECOMING
PREDOMINANTLY MVFR BASED DURING THE AFTERNOON PRIOR TO WIND SHIFT.
CONDITIONS ARE EXPECTED TO IMPROVE TO VFR CAVOK SHORTLY AFTER WIND
SHIFT FROM WEST TO EAST. 24/RR
MARINE...
SOME GRADIENT RESPONSE THIS MORNING HAS WINDS IN THE 15-
20KT RANGE THIS MORNING. AS THE SURFACE LOW CURRENTLY DEVELOPING
OVER EAST TEXAS EJECTS NORTHEAST THIS MORNING...WINDS SHOULD LESSEN
TO AROUND 15 KNOTS SUSTAINED WHILE VEERING SOUTHWEST. LOW WILL THEN
SLINGSHOT A COLD FRONT INTO THE NORTH GULF THIS EVENING WHICH WILL
SWEEP EASTWARD RATHER QUICKLY OVERNIGHT. GRADIENT PRE-FRONTAL
APPEARS STRONGER THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION.
THIS SHOULD REDUCE THE WINDS TO JUST MODERATE LEVELS TONIGHT AND
TUESDAY. WINDS AND SEAS SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES
WITH BETTER COLD AIR ADVECTION LATE THURSDAY INTO FRIDAY. 24/RR
DECISION SUPPORT...
DSS CODE....YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND
MISSISSIPPI RIVER AT RED RIVER LANDING.
MARGINAL/SLIGHT RISK OF SEVERE WEATHER MONDAY.
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 69 40 71 43 / 90 20 0 0
BTR 72 45 73 45 / 80 20 0 0
ASD 71 44 71 45 / 80 30 10 0
MSY 71 47 68 50 / 70 20 0 0
GPT 68 44 67 45 / 70 40 10 0
PQL 69 40 69 43 / 60 50 10 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1001 AM EST MON FEB 15 2016
.SYNOPSIS...
ARCTIC AIR WILL BE SLOW TO ERODE TODAY AS A WARM FRONT OFFSHORE
SLOWLY MOVES WESTWARD. THIS FRONT SHOULD MOVE INLAND TONIGHT WITH
A SOAKING RAIN EXPECTED INTO EARLY TUESDAY. DRY WEATHER IS
EXPECTED FOR THE REMAINDER OF THE WEEK WITH WARM TEMPERATURES
DEVELOPING NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...ONLY ISOLATED PATCHES OF LIGHT RAIN OVER THE
EXTREME SOUTHERN AND WESTERN PORTIONS OF THE FORECAST AREA AT THIS
TIME. THERE HAS BEEN SLIGHT WARMING THE FIRST FEW HOURS AFTER
SUNRISE AND AT 9 AM UTC THE SURFACE FREEZING LINE WAS ALONG A
LINE FROM HARTSVILLE THROUGH DILLON AND BLADENBORO TO PENDERLEA.
SO IF ANY PRECIPITATION FALLS INTO AREAS NORTH OF THIS LINE OVER
THE NEXT SEVERAL HOURS PATCHY FREEZING RAINY IS STILL POSSIBLE SO
WILL CONTINUE THE FREEZING RAIN ADVISORY.
A COASTAL FRONT CONTINUE TO LURK ALONG THE COAST WITH THE ILM
TEMPERATURE NOW UP TO 40 DEGREES. THE 14 UTC HRRR SHOW THE COASTAL
FRONT MAKING IT ONSHORE AROUND 17 UTC. AS THE FRONT SHIFTS ONTO
THE COAST THE ISENTROPIC FLOW CHANCES FOR MORE WIDE SPREAD
PRECIPITATION WILL INCREASE AT THE COAST BY THE AFTERNOON AND
SPREAD INLAND.
...FROM PREVIOUS DISCUSSION...
TEMPERATURES WILL RISE OVERNIGHT AS THE WARM FRONT MAKES MORE
RAPID WESTWARD PROGRESS WITH THE TOTAL BREAKDOWN OF THE COLD WEDGE
AND ITS SUPPORTING HIGH. THE MOST SUBSTANTIAL RAINFALL SHOULD
ARRIVE LATE TONIGHT AS A STRONG 500 MB DISTURBANCE ROLLS ACROSS
THE AREA. DEEP MOISTURE AND EVEN SOME ELEVATED CONVECTIVE
INSTABILITY SHOULD ENHANCE RAINFALL RATES AND IT`S POSSIBLE 0.50
TO 1.00 INCHES OF RAIN COULD FALL TONIGHT. WITH SURFACE-BASED
PARCELS LIKELY TO REMAIN STABLE I AM NOT CONCERNED ABOUT SEVERE
WEATHER POTENTIAL...HOWEVER DON`T BE SURPRISED IF THE RADAR SHOWS
SEVERAL ROTATING STORMS OUT OVER THE GULF STREAM LATE TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...THE LATEST SPC OUTLOOK CONTINUES TO DISPLAY A
MARGINAL RISK FOR SEVERE STORMS FOR PORTIONS OF THE FORECAST AREA
TUESDAY MORNING IN ASSOCIATION WITH A PRE-FRONTAL TROUGH/APPROACHING
COLD FRONT. AROUND DAYBREAK...GUIDANCE PLACES THE NORTH-SOUTH
EXTENDED COLD FRONT ACROSS THE CENTRAL CAROLINAS AS A PRE-FRONTAL
TROUGH AHEAD OF THE SYSTEM ESSENTIALLY PLACES OUR FORECAST AREA IN
THE WARM SECTOR. WITH PWATS IN THE 1 INCH TO 1.25 INCHES
RANGE...ANTICIPATE WIDESPREAD RAINFALL DURING THE MORNING
COMMUTE...HEAVY IN NATURE AT TIMES. SEVERE WEATHER WISE...WEAKER
LAPSE RATES ALONG WITH COLDER SEA TEMPERATURES AND LACK OF ANY
DIURNAL HEATING GIVEN EARLY ONSET OF ACTIVITY WILL RESTRICT
INSTABILITY. HOWEVER...WILL NOTE THE HEALTHY LOW LEVEL JET THAT WILL
BE IN PLACE OF AROUND 50 KTS AS WELL AS THE LOW LEVEL WIND SHEAR AS
NOTED BY THE 0-3KM HELICITY VALUES OF UP TO AROUND 200 M2/S2
POSSIBLE. AS A RESULT...INTERMITTENT DAMAGING WINDS ARE POSSIBLE.
AS THE COLD FRONT PUSHES OFFSHORE BY EARLY AFTERNOON...EXPECT
IMPROVING CONDITIONS AND A DRYING TREND BEHIND THE SYSTEM FOR THE
REST OF THE DAY ON TUESDAY. ANOTHER SHORTWAVE/FRONT WILL PUSH
THROUGH LATE OVERNIGHT TUESDAY INTO EARLY WEDNESDAY...BUT DO NOT
ANTICIPATE ANY PRECIPITATION WITH THIS FEATURE AS LATEST GUIDANCE
KEEPS AVAILABLE MOISTURE NORTH OF THE AREA.
MAINLY ABOVE NORMAL TEMPERATURES EXPECTED FOR THE SHORT TERM...WITH
HIGHS IN THE MID 60S ON TUESDAY AND AROUND 60 ON TUESDAY. LOW TO MID
40S FOR OVERNIGHT LOWS TUESDAY INTO WEDNESDAY WILL DIP DOWN INTO THE
MID TO UPPER 30S AS COLD AIR ADVECTION RAMPS UP BEHIND THE SECONDARY
COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...EXPECT A COOL AND DRY START TO THE EXTENDED
PERIOD WITH A GRADUAL WARMING TREND THROUGH THE REMAINDER OF THE
WEEK AS FAIRLY WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE
SOUTHEAST. HIGH TEMPERATURES ON THURSDAY WILL BE JUST BELOW NORMAL
IN THE MID TO UPPER 50S...CLIMBING INTO THE MID TO UPPER 60S BY THE
WEEKEND AND INTO EARLY NEXT WEEK. OVERNIGHT LOWS START OFF IN THE
UPPER 30S...REACHING THE MID TO UPPER 40S.
THE ONLY NOTABLE WEATHER SYSTEM WITHIN THE EXTENDED WILL BE
TOWARDS THE END OF THE PERIOD...STEMMING FROM A SURFACE LOW
PRESSURE SYSTEM WHICH MOVES ACROSS THE NORTHERN GREAT LAKES REGION
INTO SOUTHERN CANADA FRIDAY INTO SATURDAY. THOUGH THE TEMPORAL AND
SPATIAL NATURE OF THE EXTENDING FRONTAL BOUNDARY INTO THE
CAROLINAS REMAINS UNCERTAIN AT THIS TIME...EXPECT INCREASING
CLOUDS ON SUNDAY. ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO
MONDAY AS A RESULT WILL FALL AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE FREEZING.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...VARY LITTLE PRECIP OCCURRING OVER THE CWA RIGHT
NOW. THERE WAS A REPORT OF A SNOW/SLEET MIX OVER NORTHERN
ROBESON COUNTY...BUT THAT IS IT SO FAR. WITH GOOD WARM AIR
ADVECTION JUST OFF THE DECK IN PROGRESS...EXPECTED INLAND
TERMINALS TO HAVE OCCASIONAL FREEZING RAIN THROUGH AROUND
14-15Z...WITH VERY LITTLE ACCUMULATION. BY 15Z ALL TERMINALS
ARE EXPECTED TO BE ABOVE FREEZING. WINDS WILL SLOWLY VEER
TO THE SOUTHEAST THIS AFTERNOON. DID NOT FOCUS MUCH ON THE
OVERNIGHT HOURS...HOWEVER EXPECT A SLUG OF WIDESPREAD
SHOWERS TO MOVE OVER THE REGION AFTER 06Z.
EXTENDED OUTLOOK...BECOMING VFR DURING THE DAY TUESDAY.
MVFR CONDITIONS ARE POSSIBLE LATE FRIDAY
AND SATURDAY WITH A FRONTAL BOUNDARY MOVING INTO THE VICINITY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM MONDAY...A WARM FRONT CURRENTLY LOCATED 25-40 MILES
EAST OF THE BEACHES WILL CRAWL WESTWARD...APPROACHING THE COAST
NORTH OF CAPE FEAR AROUND NOON...AND FINALLY REACHING THE SC COAST
INCLUDING THE GRAND STRAND BY LATE IN THE DAY. THIS BOUNDARY WILL
SEPARATE S TO SE WINDS ON THE EAST (WARM) SIDE FROM NE WINDS ON
THE WEST (COLD) SIDE. STRENGTHENING SE WINDS WELL OFFSHORE SHOULD
LEAD TO INCREASING SWELL TODAY AND A SMALL CRAFT ADVISORY WILL
REMAIN POSTED EVEN FOR AREAS WHERE WIND SPEEDS REMAIN WELL BELOW
25 KNOTS.
BY TONIGHT THE WARM FRONT SHOULD MOVE COMPLETELY ONSHORE AND
STRENGTHENING SSE WINDS SHOULD REACH 25 KNOTS...ESPECIALLY ACROSS
THE WARMER SEA SURFACE TEMPERATURES GREATER THAN 10 MILES FROM
SHORE. SWELL WILL CONTINUE TO BUILD AND ITS POSSIBLE WE COULD SEE
SEA HEIGHTS EXCEEDING 10 FEET LATE TONIGHT NEAR CAPE FEAR.
WAVES OF RAIN DEVELOPING THIS MORNING MAY DIMINISH THIS
EVENING...HOWEVER RAIN SHOULD REDEVELOP LATE TONIGHT AND MAY BE
ACCOMPANIED BY A FEW STRONG THUNDERSTORMS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT THROUGH
TUESDAY AFTERNOON.
A PRE-FRONTAL TROUGH WILL PUSH ACROSS THE WATERS TUESDAY MORNING
ALLOWING FOR SOUTHERLY WINDS 15 TO 25 KTS TO PREVAIL...FOLLOWED BY A
COLD FRONT WHICH PUSHES OFFSHORE JUST TO THE NORTH AND WINDS VEERING
SOUTHWESTERLY TO WESTERLY...15 TO 20 KTS. WILL SEE A DECREASE IN
SUSTAINED WINDS TO AROUND 10 TO 15 KTS INTO EARLY WEDNESDAY MORNING
AS WEAK HIGH PRESSURE BEGINS TO BUILD IN...VEERING WINDS EVEN MORE
TO NORTHWEST. ALONG WITH WINDS...SEAS UP TO 6 TO 10 FT WILL WARRANT
A SMALL CRAFT ADVISORY FOR THE WATERS THROUGH THE DAY ON
TUESDAY...POSSIBLY CONTINUING INTO THE EVENING HOURS. SEAS DROP OFF
ON WEDNESDAY TO 3 TO 5 FT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS
THE WATERS TOWARDS THE END OF THE WEEK. NORTHERLY WINDS 10 TO 15
KTS WILL PREVAIL ON THURSDAY...BECOMING NORTHEASTERLY ON FRIDAY AS
HIGH PRESSURE SHIFTS OFFSHORE. SEAS OF 2 TO 4 FT EXPECTED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
SCZ017-023-024.
NC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NCZ087-096.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST TUESDAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...DRH/TRA
SHORT TERM...SGL
LONG TERM...SGL
AVIATION...DL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
824 AM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 823 AM CST MON FEB 15 2016
GETTING A SMALL BAND OF SNOW SHOWERS THAT JUST PASSED THROUGH THE
OFFICE...ONLY A DUSTING BUT HEAVY SNOW FOR ABOUT 15 MIN. HAVE
ADDED POPS FOR THIS AND TIMED IT OUT OF THE EAST BY 18Z USING
TIME/DISTANCE METHOD. FOR NOW NO OTHER CHANGES.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS
SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE
BLEND FOR NOW.
A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE
OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME
WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER
THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR
IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE
WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES
SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF
CLOUD COVER.
NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA
THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING
BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT
GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY
WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT
STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL
NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST
SW OF THE FA.
FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING
COOLER TEMPERATURES TO THE REGION TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH
BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE
WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR
WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY
LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO.
HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND
WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO
RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY.
WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD.
THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID-
LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH
THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO
MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE
DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS
AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH
BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE
AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL
FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER
AIR FEATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 626 AM CST MON FEB 15 2016
ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS
STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE
SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW
LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY
VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE
AFTERNOON/EVENING AS NEXT WAVE DROPS SE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
631 AM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 626 AM CST MON FEB 15 2016
EXPANDED THE AREA BUT TRIMMED LOW POPS TO FLURRIES AS METARS NOT
INDICATING ANY LOWERING OF VSBY IN SNOW. NO OTHER CHANGES MADE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS
SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE
BLEND FOR NOW.
A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE
OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME
WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER
THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR
IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE
WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES
SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF
CLOUD COVER.
NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA
THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING
BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT
GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY
WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT
STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL
NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST
SW OF THE FA.
FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING
COOLER TEMPERATURES TO THE REGION TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH
BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE
WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR
WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY
LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO.
HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND
WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO
RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY.
WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD.
THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID-
LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH
THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO
MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE
DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS
AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH
BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE
AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL
FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER
AIR FEATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 626 AM CST MON FEB 15 2016
ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS
STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE
SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW
LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY
VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE
AFTERNOON/EVENING AS NEXT WAVE DROPS SE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...VOELKER
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
651 AM EST MON FEB 15 2016
.SYNOPSIS...
COLD ARCTIC HIGH PRESSURE LOCATED OVER NEW ENGLAND AND RIDGING
DOWN ACROSS THE CAROLINAS WILL MOVE EAST AND OVER THE ATLANTIC
TODAY. MEANWHILE...A MOIST STORM SYSTEM WILL CROSS OUR AREA FROM
THE WEST TONIGHT AND TUESDAY. A FAST MOVING UPPER LEVEL SYSTEM WILL
REACH THE MOUNTAINS LATE TUESDAY...BEFORE DRY AND MILDER HIGH
PRESSURE RETURNS AND REMAINS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM EST...A BAND OF UPGLIDE INDUCED PRECIPITATION HAS
STARTED BREAKING OUT ACROSS WESTERN NORTH CAROLINA EARLY THIS
MORNING...BUT ANY PRECIP HAS BEEN MUCH SPOTTIER IN SOUTHERN
SECTIONS. STILL ANTICIPATE A GRADUAL INCREASE IN PRECIP COVERAGE
ACROSS THE REGION THROUGH THE MORNING HOURS AS ATLANTIC AND GULF
MOISTURE SLOWLY FILL IN AND ISENTROPIC LIFT GRADUALLY IMPROVES.
MEANWHILE...WATER VAPOR IMAGERY SHOWS AN UPSTREAM TROUGH DIGGING
TOWARD THE LOWER MS RIVER VALLEY THROUGH THE DAY...WHILE A 1034 MB
SURFACE HIGH PRESSURE SLIPS EAST OFF THE DELMARVA COAST BUT
CONTINUES TO EXTEND A RIDGE AXIS SOUTHWARD ACROSS THE FORECAST AREA
IN A FAVORABLE COLD AIR DAMMING CONFIGURATION. TEMPERATURES REMAIN
MOSTLY IN THE 20S WITH DEWPOINTS IN THE TEENS. IN ADDITION...WET
BULB PROFILES ON THE LATEST RAP SHOW ONLY A VERY MODEST WARM NOSE
ACROSS THE REGION. THIS REMAINS A GOOD SETUP FOR FREEZING/FROZEN
PRECIPITATION THROUGHOUT ACROSS THE NORTHERN TIER...WITH MAINLY FZRA
SOUTH.
ALTHOUGH ISENTROPIC LIFT IS EXPECTED TO STEADILY ACTIVATE ACROSS THE
REGION TODAY AHEAD OF THE DIGGING WAVE...THE NUMERICAL MODELS REMAIN
SOMEWHAT STINGY ON QPF FOR MUCH OF THE DAY...WITH BETTER AMOUNTS
JUST NORTH AND WEST OF THE CWFA. THE QUANDARY FOR THE IMMEDIATE NEAR
TERM IS THAT VERY COLD/DRY AIR IS IN PLACE BUT WE WILL HAVE LESS QPF
TO WORK WITH. STILL ANTICIPATE THE DEVELOPING WARM NOSE IN THE
IMPROVING WARM ADVECTION TO WORK NORTHWARD ACROSS THE REGION
TODAY...AND MOST LOCATIONS WILL SEE A 12Z TO 18Z TRANSITION OF ANY
PRECIPITATION THAT IS FALLING FROM FROZEN TO FREEZING PTYPES.
ALTHOUGH ONLY VERY LIGHT QPF WILL IMPACT THE LOWER PIEDMONT...THE
FREEZING RAIN ADVISORY HAS BEEN EXPANDED TO THE ABBEVILLE TO CHESTER
TIER SINCE ANY PRECIPITATION AT ALL WILL QUICKLY CREATE A GLAZE ON
COLD SURFACES. ANOTHER ADJUSTMENT WAS TO PERMIT THE ADVISORY FOR
GRAHAM/SWAIN TO EXPIRE AT 18Z SINCE THE SOUTHWEST MOUNTAINS WILL BE
THE FIRST TO TRANSITION OVER TO RAIN THROUGH MIDDAY AS THE WARM NOSE
ARRIVES...PLUS THERE WILL BE NO SURFACE COLD LAYER THERE OUTSIDE OF
THE DAMMING REGION. OTHERWISE...THE NORTHERN NC BLUE RIDGE AND
ADJACENT FOOTHILL AREAS WILL BE THE LAST HOLDOUT FOR ANY APPRECIABLE
SNOW/SLEET INTO THE AFTERNOON HOURS.
THE INCREASINGLY NEGATIVE TILT UPPER WAVE WILL BE ON THE MOVE ACROSS
THE DEEP SOUTH AND IT SHOULD LIFT ACROSS THE REGION TONIGHT TO
PROVIDE THE BEST PERIOD OF DEEP MOISTURE AND FORCING. THE HEAVIEST
PRECIPITATION SHOULD WRAP INTO THE AREA AHEAD OF THE ADVANCING
SURFACE LOW CENTER THIS EVENING. THE GFS/ECMWF TAKE THIS SURFACE LOW
WEST OF THE MOUNTAINS...BUT THE NAM HAS A CIRCULATION MOVING EAST OF
THE MOUNTAINS ALONG THE WEDGE BOUNDARY...AND IT IS LIKELY ONTO
SOMETHING THERE. FREEZING TEMPERATURES COULD THUS BE LOCKED IN FOR A
GOOD CHUNK OF THE NORTHERN PART OF FORECAST AREA INTO THE EARLY
EVENING...AND THIS WILL BOOST ICE ACCUMULATIONS ESPECIALLY OVER THE
NC FOOTHILLS AND EASTERN BLUE RIDGE AS THE BETTER QPF ARRIVES.
ANTICIPATE DRY SLOTTING WRAPPING FROM THE SW AFTER 09Z...BUT WITH NW
FLOW MOISTURE CONTINUING ACROSS THE WESTERN MOUNTAINS THROUGH
DAYBREAK TUESDAY. THE WARNING FOR THE NORTHERN MOUNTAINS COULD NEED
SOME EXTENSION IF MIXED PTYPES PERSIST ON THE NW FLOW...BUT WILL
LEAVE IT AT MIDNIGHT FOR NOW. WILL CONTINUE TO OMIT ANY PIEDMONT
THUNDER CHANCES TONIGHT AS IT APPEARS THAT THE BETTER SURFACE BASED
INSTABILITY WILL PASS JUST SOUTHEAST OF THE FORECAST AREA OVERNIGHT.
ALSO...HYDRO PROBLEMS WILL LIKELY BE LIMITED BY THE SHORT
DURATION...GENERALLY 00Z TO 09Z...OF THE MODERATE TO BRIEFLY HEAVY
RAINFALL WITH THE PASSING TROUGH.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 250 AM MONDAY...THE SHORT TERM PICKS UP AT 12Z TUESDAY...WITH
MODELS IN PRETTY GOOD AGREEMENT ON THE AXIS OF A NEGATIVELY-TILTED
500 MB TROUGH BISECTING THE CWFA. THE DRY SLOT OF THIS STORM SYSTEM
WILL HAVE PUNCHED INTO THE AREA BY AROUND DAYBREAK TUESDAY...SO POP
WILL QUICKLY TAPER OFF FROM WEST TO EAST. THERE WILL BE SOME
LINGERING SLIGHT TO LOW-END CHANCE POPS IN THE NC MOUNTAINS...BUT
OTHERWISE THINGS SHOULD BEGIN TO DRY OUT. ANOTHER POTENT SHORT WAVE
WILL BE DIVING THRU THE BASE OF THE LONG WAVE TROUGH TUESDAY
EVENING...KEEPING FLOW BACKED OUT OF THE SW...AND BRINGING A BRIEF
SHOT OF MOISTURE. SO EXPECT SOME SUNSHINE EAST OF THE MOUNTAINS FROM
LATE MORNING TO EARLY AFTERNOON...BUT QUICKLY CLOUDING BACK UP WITH
THE APPROACHING WAVE. THE FORECAST SOUNDINGS SHOW STEEPENING LOW-MID
LEVEL LAPSE RATES...SO ANY LINGERING PRECIP SHOULD TRANSITION BACK
TO MAINLY HIGH-ELEVATION SNOW AND LOWER RAIN. HIGHS WILL BE JUST
BELOW NORMAL.
TUESDAY NIGHT...AS THE UPPER WAVE EXITS TO THE EAST...LOW LEVEL FLOW
TURNS OUT OF THE NW FOR A BRIEF NWFS EVENT. CONDITIONS DO NOT LOOK
THAT IMPRESSIVE FOR ANYTHING MORE THAN AN INCH OR TWO OF SNOW
OVERNIGHT...MAINLY ABOVE 3500 FT. SINCE ADVISORY IS TWO INCHES IN 12
HOURS...WILL PLAN TO MENTION SNOW IN HWO FOR THE TN BORDER COUNTIES.
OTHERWISE...EXPECT ANY PRECIP EAST OF THE MOUNTAINS TO QUICKLY END
BY LATE EVENING...WITH TEMPS FALLING INTO THE MID TO UPPER 30S.
WEDNESDAY THRU WEDNESDAY NIGHT...THE EASTERN CONUS TROUGH WILL BE
REINFORCED BY YET ANOTHER SHORT WAVE DIVING THRU IT...BUT THE WAVE
SHOULD HAVE LITTLE MOISTURE TO WORK WITH. PERHAPS A FEW SNOW SHOWERS
OR FLURRIES ALONG THE TN LINE...MAINLY WEDNESDAY EVENING.
OTHERWISE...SOME INCREASE IN CLOUDS AND TEMPS STAYING JUST SLIGHTLY
BELOW NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 310 AM MONDAY...THE LONG TERM STARTS OUT 12Z THURSDAY...WITH A
MILDER POLAR AIR MASS THAN WE HAVE SEEN THE LAST COUPLE WEEKS ACROSS
THE REGION. STILL...THURSDAY LOOKS COOL UNDER SUNNY SKIES. HIGHS A
CATEGORY OR TWO BELOW NORMAL.
FRIDAY THRU THE NEXT WEEKEND...UPPER LEVEL FLOW BECOMES
QUASI-ZONAL...RESULTING IN NEAR NORMAL TO ABOVE NORMAL TEMPS FOR THE
FIRST TIME SINCE THE BEGINNING OF THIS MONTH. A CLIPPER SYSTEM WILL
CROSS THE GREAT LAKES...PUSHING A COLD FRONT ACROSS THE CWFA...BUT
WITH LITTLE MOISTURE FRIDAY NIGHT. THE 00Z GFS AND ECMWF BEGIN TO
DIVERGE BY SUNDAY...WITH THE GFS SHOWING A ZONALLY-ORIENTED FRONT
PROVIDING INCREASED PRECIP CHANCES...WHILE THE ECMWF IS MORE
AMPLIFIED AND SLOWER TO BRING THE FRONT AND PRECIP IN FROM THE WEST.
FOR NOW...I WILL FORECAST SLIGHT TO MID CHANCE FOR RAIN RETURNING
FROM THE WEST SUNDAY AFTERNOON THRU SUNDAY NIGHT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT...MVFR CLOUDS ARE SOLIDLY IN PLACE AT THE AIRFIELD THIS
MORNING...BUT THE UPGLIDE PRECIPITATION BAND HAS REMAINED JUST NORTH
OF THE VICINITY THUS FAR. ANY FURTHER DEGRADATION IN CONDITIONS WILL
BE VERY SLOW TO DEVELOP THROUGH THE MORNING AS MOIST UPGLIDE SLOWLY
BUILDS. WILL TEMPO IN -FZRA AND SLEET FOR A FEW HOURS...BUT THE
ENCROACHING WARM NOSE WILL SUPPORT MAINLY -FZRA GOING FORWARD AFTER
ABOUT 15Z. CEILINGS WILL TRANSITION DOWN INTO MORE SOLID IFR THROUGH
THE AFTERNOON HOURS...WITH STEADIER RAIN AND LIFR CONDITIONS LIKELY
THIS EVENING AS THE LOW APPROACHES FROM THE WEST. THE GRADUAL
EROSION OF COLD AIR DAMMING TONIGHT SHOULD UNCOVER LLWS CONDITIONS
BY LATE EVENING. SURFACE WINDS WILL BE MAINLY NE LESS THAN 10 KT
THROUGH THE PERIOD...BUT BECOMING STRONGER SOUTHERLY NEAR THE END OF
THE TAF PERIOD AS THE WEDGE BOUNDARY LIFTS THROUGH.
ELSEWHERE...SNOW...SLEET...AND FREEZING RAIN WILL BE ON THE INCREASE
ACROSS THE NC TAF SITES THIS MORNING...BUT WITH ONLY A GRADUAL
UPTICK IN UPGLIDE PRECIPITATION ACROSS THE SC SITES. EXPECT MAINLY
FREEZING RAIN WITH ANYTHING THAT FALLS FROM LATE MORNING
ONWARD...ALTHOUGH SLEET COULD LINGER AT KHKY. THE PRECIP WILL
TRANSITION TO RAIN FROM THE SOUTH THROUGH LATE DAY...BUT FREEZING RAIN
COULD LINGER INTO THE EVENING IN THE NARROWING CAD REGION FROM KGSP
TO KHKY. CEILINGS WILL TRANSITION DOWN SLOWLY THROUGH MVFR...
REACHING IFR BY LATE MORNING INTO EARLY AFTERNOON...AND LIFR LIKELY
BY EVENING AS THE HEAVIER RAINFALL SPREADS IN FROM THE WEST. EXPECT
MAINLY NE WINDS LESS THAN 10 KT IN THE CAD LAYER...BUT WITH SE TO
SOUTHERLY FLOW DEVELOPING LATE...WITH LOW END GUSTS...AND SE FLOW
PERSISTING INTO THE FRENCH BROAD VALLEY NEAR KAVL.
OUTLOOK...THE PASSING SURFACE LOW AND UPPER LEVEL TROUGH WILL LIFT
THROUGH THE REGION EARLY TUESDAY MORNING TO GRADUALLY TAPER OFF
PRECIPITATION. RESTRICTIONS COULD LINGER THROUGH TUESDAY IN SOME
PLACES GIVEN THE NEAR GROUND MOISTURE. ANOTHER TROUGH WILL CROSS THE
REGION TUESDAY NIGHT...WITH ADDITIONAL WINTRY PRECIPITATION AND
RESTRICTIONS POSSIBLE MAINLY AT KAVL. OTHERWISE...EXPECT DRYING
THROUGH THE WEEK.
CONFIDENCE TABLE...
12-18Z 18-24Z 00-06Z 06-12Z
KCLT HIGH 83% MED 67% HIGH 87% HIGH 92%
KGSP HIGH 84% MED 76% HIGH 87% MED 79%
KAVL HIGH 85% HIGH 88% HIGH 94% HIGH 90%
KHKY HIGH 86% HIGH 87% HIGH 92% HIGH 85%
KGMU HIGH 83% MED 78% HIGH 81% MED 76%
KAND HIGH 95% MED 70% HIGH 82% MED 75%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK:
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR GAZ010-
017.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR GAZ018-
026-028.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
GAZ029.
NC...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NCZ033-035-
049-050-501>506.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ048-
052-057-059-062>064-071-072.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ082.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ036-
037-053-056-065-068>070-507>510.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NCZ051-058.
SC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR SCZ001-
002.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR
SCZ004>010-012>014.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR SCZ003.
FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
SCZ011-019.
&&
$$
SYNOPSIS...DEO
NEAR TERM...HG
SHORT TERM...ARK
LONG TERM...ARK
AVIATION...HG
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
602 AM CST MON FEB 15 2016
.AVIATION...
/12Z TAFS/
LIFR/VLIFR VBSYS AND CIGS ARE AFFECTING AREAS ALONG THE I-35
CORRIDOR. THESE CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS
MORNING AS A COLD FRONT PUSHES THROUGH THE AREA. A WIND SHIFT FROM
THE NORTHWEST TO NORTH IS EXPECTED ACROSS KAUS/AND KATT AROUND 14
TO 15Z AND ACROSS KSAT BETWEEN 15Z TO 16Z IH. IN THE WAKE OF THE
FRONT...WINDS WILL BE FROM THE NORTHWEST TO NORTH. BREEZY
NORTHERLY WINDS WILL PREVAIL FOR MUCH OF THE AFTERNOON WITH GUSTS
UP TO 25 KNOTS. VFR CONDITIONS ARE ANTICIPATED FOR THE EVENING AND
LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 402 AM CST MON FIB 15 2016/
SHORT TERM (TODAY THROUGH TUESDAY)...
MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG
AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON
TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE
RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED
TODAY AND TUESDAY.
WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH
PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME
LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER
LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR
LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH-
CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE
FRONT THAT IS NOW LOCATED ALONG A DALL`S TO WACS TO OZONA LINE.
LOW CLOUDS AND AREAS OF FOG WILL OCCUR NOW THROUGH 8-10AM WITH
SOME POCKETS OF DENSE FOG POSSIBLE ALONG WITH DRIZZLE/MIST WHERE
THE FOG/LOW CLOUDS ARE THICKER NEAR THE SURFACE.
THE WEAK BOUNDARY WILL SWEEP THROUGH THE HILL COUNTRY AND AUSTIN BY
7-9AM AND THROUGH SAN ANTONIO BEFORE 11AM. RAPID CLEARING OF CLOUDS
IS EXPECTED BEHIND THE BOUNDARY WITH SUNNY CONDITIONS AND BREEZY
NORTH WINDS EXPECTED THIS AFTERNOON. THE COMBINATION OF WINDS
GUSTING TO NEAR 20-25 MPH AND THE DRIER AIR MOVING IN WILL
PROMOTE ELEVATED FIRE WEATHER CONDITIONS ACROSS THE RIO GRANDE
PLAINS AS RELATIVE HUMIDITY VALUES DIP NEAR TO JUST BELOW 20% THIS
AFTERNOON.
FOR TUESDAY...A SLIGHTLY COOLER MORNING IS EXPECTED GIVEN THE
DRIER AIR AND NEAR CALM WINDS BUT READINGS WILL BE NEAR CLIMATE
NORMALS. EXPECTED CLEAR SKIES WITH PLENTY OF SUN WITH HIGHS
REACHING ABOVE NORMAL INTO THE UPPER 70S AND LOW 80S ARTIE. SOME
LOCATIONS IN THE RIO GRANDE PLAINS COULD REACH INTO THE MID 80S.
LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
WELL ABOVE NORMAL TEMPERATURES OF 10-15F DEGREES ARE EXPECTED MID TO
LATE WEEK WITH A SLIGHT COOL DOWN INTO THE WEEKEND. DRY
CONDITIONS WILL ALSO REMAIN UNTIL EARLY NEXT WEEK WHERE A MORE
SUBSTANTIAL COLD FRONT AND BETTER RAIN CHANCES COULD OCCUR.
CONUS PATTERN MID TO LATE WEEK WILL FEATURE SURFACE HIGH PRESSURE
OVER THE MID-MS RIVER VALLEY WITH SOUTHEAST LOW-LVL FLOW THAT VEERS
TO THE SOUTHWEST/WEST IN THE MID-LVL OVER TEXAS. THIS TYPE OF
PATTERN ALONG WITH A BUILDING H5 RIDGE AND H925 TEMPS 23-16C FROM
WEST TO EAST WILL SUPPORT UPPER 70S TO MID 80S. WHILE IT WILL BE
WARM...RECORD TEMPERATURES DO NOT LOOK TO BE IN JEOPARDY AS THOSE
VALUES ARE ALREADY WELL INTO THE 90S. MORNING CLOUDS LOOK TO
RETURN THURSDAY AND FRIDAY BUT QUICK MIX OUTS BY MID MORNING HOURS
TO PARTLY AND MOSTLY SUNNY SKIES WILL OCCUR. SLIGHTLY COOLER H925
AIR WILL PIVOT IN ACROSS THE REGION THIS WEEKEND AS THE H5 RIDGE
BREAKS DOWN AND SOME WEAK IMPULSES MIGRATE OVER THE REGION THAT
WILL CREATE SOME MORE MID-LVL CLOUDS.
GLOBAL LONG RANGE MODELS CONTINUE TO HINT AT IN DECENT ACCORD A MORE
ACTIVE SOUTHERN JET STREAK BRANCH OVER SOUTH TEXAS NEXT SUNDAY-
TUESDAY. THIS ACTIVE BRANCH WILL HELP BUCKLE THE FLOW WITH ENHANCED
TROUGHING THAT, IN CONJUNCTION WITH THE POLAR JET, WILL AID A
STRONGER CANADIAN ORIGINATED FRONT TO APPROACH THE AREA AROUND
MONDAY. THIS STRONGER FRONT AND BETTER DYNAMIC SUPPORT SHOULD ALLOW
FOR BETTER RAIN/STORM CHANCES IN THIS TIME FRAME. WILL CONTINUE
TO MONITOR THE EVOLUTION OF THIS SYSTEM AND ITS LIKELY MORE
WIDESPREAD RAIN SIGNAL FOR THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 75 47 81 50 82 / 10 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 43 80 45 81 / 10 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 77 44 81 47 81 / - 0 0 0 0
BURNET MUNI AIRPORT 73 44 79 46 80 / - 0 0 0 0
DEL RIO INTL AIRPORT 80 46 85 51 87 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 73 44 80 46 80 / 10 0 0 0 0
HONDO MUNI AIRPORT 80 42 82 46 83 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 44 79 46 79 / - 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 46 79 47 80 / 10 0 0 0 0
SAN ANTONIO INTL AIRPORT 77 46 80 49 82 / 0 0 0 0 0
STINSON MUNI AIRPORT 79 46 82 48 82 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...ALLEN
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
440 AM CST MON FEB 15 2016
.AVIATION...
VFR. LIGHT NW WINDS BECMG SWLY AROUND 11 KNOTS BY MIDDAY.
&&
.PREV DISCUSSION... /ISSUED 339 AM CST MON FEB 15 2016/
SHORT TERM...
IN THE WAKE OF A MINOR TROUGH THAT MANAGED TO GENERATE MID-LEVEL
CLOUDS AND VIRGA OVER OVER THE SERN PANHANDLE LAST NIGHT...BROAD
SURFACE RIDGING CENTERED IN NERN NM WILL TRANSLATE SEWD UNDER DRY
NW FLOW. DEPARTURE OF THIS RIDGE BY LATE MORNING AND SUBSEQUENT
DOWNSLOPE FLOW WILL AID IN LEE TROUGH DEVELOPMENT OVER EASTERN NM
COMPLETE WITH SOME BREEZY W-SW WINDS LOCALLY. CONTINUE TO SIDE
WITH THE DRIER RUC AND HRRR FOR AFTERNOON DEWPOINTS AS REMAINING
GUIDANCE HAS BEEN TOO GENEROUS WITH THESE IN RECENT DAYS...IF NOT
WEEKS. UPSHOT OF THIS IS THAT MILDER MAV HIGH TEMPS REMAIN FAVORED
OVER THE COOL SUPERBLEND. SW WINDS TONIGHT WILL VEER W-NW BEFORE
DAYBREAK TUE IN ADVANCE OF A DECAYING COLD FRONT AND DISTANT
TROUGH TRACKING ALONG THE MIDDLE MISSOURI RIVER VALLEY.
LONG TERM...
QUIET WEATHER WILL CONTINUE THROUGH MUCH OF THE WEEK AS DRY
NORTHWEST FLOW GRADUALLY TRANSITIONS TO SOUTHWESTERLY/ZONAL BY THE
END OF THE WEEK. A WEAK FRONT WILL PUSH THROUGH EARLY TUESDAY
KEEPING TEMPERATURES IN THE MID 60S TO LOW 70S FOR HIGHS AND LOWS
IN THE MID 30S TO LOWER 40S. RIDGE WILL MOVE OVER THE REGION ON
WEDNESDAY WHICH WILL START WARMING TEMPERATURES WELL ABOVE NORMAL
FOR MID-WEEK. WARMEST DAY STILL LOOKS TO BE THURSDAY WHEN
SOUTHWESTERLY FLOW WILL DEVELOP AT THE SURFACE HELPING TO BOOST
HIGHS INTO THE LOW 80S.
WEAK SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE FRIDAY THROUGH
THE END OF THE FORECAST. THIS WILL KEEP BOUNDARY LAYER MOISTURE IN
PLACE EITHER OVER OR NEAR THE FORECAST AREA THROUGH SOME POINT
OVER THE WEEKEND OR FIRST PART OF NEXT WEEK. THERE CONTINUES TO BE
DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE ARRIVAL OF A COLD
FRONT AT THE END OF THE UPCOMING WEEKEND OR FIRST PART OF NEXT
WEEK. DIFFERENCES SURROUND THE STRENGTH OF A WAVE/CLOSED LOW THAT
SWINGS OUT ACROSS THE NORTHERN PLAINS OVER THE GREAT LAKES. ECMWF
DEVELOPS A CLOSED LOW RESULTING IN A STRONGER FRONT THAT PUSHES
THROUGH ON SUNDAY WHILE THE GFS IS MUCH WEAKER THAN THE ECMWF.
MODELS TRY TO BREAK OUT PRECIPITATION IN VARYING AMOUNTS AND
COVERAGE AND SUPERBLEND OUTPUT CONTINUES TO CARRY POPS FOR
SATURDAY INTO SUNDAY. BECAUSE OF THE DIFFERENCES IN THE MODELS...
ECMWF IS MUCH DRIER THAN THE GFS...WILL KEEP POPS OUT OF THE
FORECAST FOR NOW UNTIL WE SEE IF THE EXTENDED RANGE FORECAST CAN
COME INTO BETTER CONSENSUS.
JORDAN
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/14/93
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1201 PM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 1035 AM CST MON FEB 15 2016
Will update the forecast around 11 am and plan to end the dense
fog advisory about one hour early. Still have a few pockets of
dense fog at 10 am at Bloomington, Lawrenceville, Mattoon,
Taylorville and Litchfield. Visibilities have been slowly
improving late this morning and expect this trend to continue into
midday. A low overcast with bases around or less than 500 feet
cover much of IL late this morning. There are some large breaks in
the low clouds over MO and these should lift ne into central IL
during the afternoon especially sw CWA. Highs this afternoon in
the low to mid 30s with mildest readings sw CWA where more breaks
in low clouds expected. Winds to stay fairly light today, sw less
then 10 mph. Upper level trof from the upper MS river valley into
western MO and near OK/AR border to push east into IL this
evening. 1009 mb surface low pressure along the LA/MS border to
deepen ne into northern AL at 1003 mb by 00Z/6 pm and keeps it
precipitation se of the Ohio river. The upper level trof will tend
to keep low clouds around central/se IL this afternoon and evening
with mostly cloudy to overcast skies.
&&
.SHORT TERM...(Today)
ISSUED AT 314 AM CST MON FEB 15 2016
08z/2am radar imagery continues to indicate patchy freezing drizzle
across central Illinois: however, the areal coverage and intensity
has decreased markedly from earlier in the evening. As light
southerly winds flow over the cold/snow-covered ground, expect fog
and perhaps some drizzle to persist through the morning. Current
visibilities are mostly in the 2-5 mile range, but HRRR suggests the
potential for even lower visbys as WAA continues and low overcast
lifts. Have seen a few reports of 1/4 mile visbys upstream across
central Missouri where clouds have temporarily cleared and expect
the fog to thicken/spread northeastward into central Illinois over
the next few hours. Will need to carefully monitor trends, as a
Dense Fog Advisory could be needed if HRRR verifies. For now, will
just mention areas of fog in the forecast through midday. A weak
short-wave trough evident on latest water vapor imagery over eastern
Nebraska will pass to the W/SW of the area today. A small area of
light snow associated with this feature over southwest Iowa will
spread across northern Missouri and may approach the far SW CWA
toward midday: however, all high-res models show the precip
dissipating before arriving. Have therefore gone with a dry
forecast. Despite continued southerly flow, fog and extensive cloud
cover will keep afternoon high temperatures in the middle to upper
30s.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 314 AM CST MON FEB 15 2016
The next fast-moving storm system embedded within the prevailing
northwesterly flow aloft will arrive late tonight into Tuesday,
bringing another period of wintry precip to central Illinois. 00z
Feb 15 models have all trended south with the track of this system,
with the NAM being the furthest north and the GEM the furthest
south. Have rejected these two solutions in favor of the middle
of the road GFS, which takes the 500mb vort max from northern
Missouri 12z Tue to far southern Illinois by 18z Tue. Given this
particular track, the heaviest precip will be focused across the
central/southern CWA. Have therefore reduced PoPs into the
chance category along/north of I-74...while maintaining likely
further south across the remainder of the area. Another
consequence of a further south track is a slightly colder thermal
profile. GFS forecast soundings are generally cold enough for
snow initially as the max temp in the elevated warm layer only
reaches about 1C. As a result, am expecting snow Tuesday
morning, gradually transitioning to a rain/snow mix by afternoon
as surface temps rise into the middle to upper 30s. Due to the
southward track shift, relatively light precip, and marginal
temps...snow accumulations are expected to remain minor. Will
see a band of around 1 inch along/southwest of a Canton...to
Decatur...to Marshall line...with less than one half inch north of
I-74.
Another weak short-wave will pass through the region on Wednesday:
however, this feature will be moisture-starved and will produce
little more than some cloud cover. Once this wave exits, upper
heights will begin to rise in earnest in response to a major
system coming onshore along the Pacific Coast. Downstream
ridging across the central and eastern CONUS will allow a
pronounced warming trend to occur by the end of the week. Models
have been consistently advertising temps reaching the upper 40s
and lower 50s by Thursday, then climbing into the upper 50s and
lower 60s on Friday. A weak cold front is still progged to pass
through Illinois on Friday, but with only limited moisture to work
with, will only mention slight chance for showers with FROPA.
After that, temps cool a bit over the weekend, but remain above
normal in the 50s for both Saturday and Sunday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1159 AM CST MON FEB 15 2016
Widespread fog still lingers across central IL airports at midday
with visibilities ranging from 1/8 mile at BMI, 1/2 mile at CMI
while PIA, SPI and DEC up to 2-3 miles. Vsbys to gradually lift to
MVFR next few hours while ceilings of 100-500 ft nudge up to
500-1k ft later this afternoon. Ceilings could even lift to low
end MVFR for a time later this afternoon and evening especially
sw airports but think ceilings will lower back down to IFR
overnight into Tue morning. Yet another northern stream short
wave/trof over northern high plains to dive quickly se into the
mid MS river valley by 18Z/noon Tue. Best chances of light snow
will be over sw IL Tue morning and carried 3 miles light snow at
SPI and DEC while just vcsh along I-74 taf sites. Winds stay
fairly light next 24 hours from sw direction this afternoon and
veering east by Tue morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1040 AM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 1035 AM CST MON FEB 15 2016
Will update the forecast around 11 am and plan to end the dense
fog advisory about one hour early. Still have a few pockets of
dense fog at 10 am at Bloomington, Lawrenceville, Mattoon,
Taylorville and Litchfield. Visibilities have been slowly
improving late this morning and expect this trend to continue into
midday. A low overcast with bases around or less than 500 feet
cover much of IL late this morning. There are some large breaks in
the low clouds over MO and these should lift ne into central IL
during the afternoon especially sw CWA. Highs this afternoon in
the low to mid 30s with mildest readings sw CWA where more breaks
in low clouds expected. Winds to stay fairly light today, sw less
then 10 mph. Upper level trof from the upper MS river valley into
western MO and near OK/AR border to push east into IL this
evening. 1009 mb surface low pressure along the LA/MS border to
deepen ne into northern AL at 1003 mb by 00Z/6 pm and keeps it
precipitation se of the Ohio river. The upper level trof will tend
to keep low clouds around central/se IL this afternoon and evening
with mostly cloudy to overcast skies.
&&
.SHORT TERM...(Today)
ISSUED AT 314 AM CST MON FEB 15 2016
08z/2am radar imagery continues to indicate patchy freezing drizzle
across central Illinois: however, the areal coverage and intensity
has decreased markedly from earlier in the evening. As light
southerly winds flow over the cold/snow-covered ground, expect fog
and perhaps some drizzle to persist through the morning. Current
visibilities are mostly in the 2-5 mile range, but HRRR suggests the
potential for even lower visbys as WAA continues and low overcast
lifts. Have seen a few reports of 1/4 mile visbys upstream across
central Missouri where clouds have temporarily cleared and expect
the fog to thicken/spread northeastward into central Illinois over
the next few hours. Will need to carefully monitor trends, as a
Dense Fog Advisory could be needed if HRRR verifies. For now, will
just mention areas of fog in the forecast through midday. A weak
short-wave trough evident on latest water vapor imagery over eastern
Nebraska will pass to the W/SW of the area today. A small area of
light snow associated with this feature over southwest Iowa will
spread across northern Missouri and may approach the far SW CWA
toward midday: however, all high-res models show the precip
dissipating before arriving. Have therefore gone with a dry
forecast. Despite continued southerly flow, fog and extensive cloud
cover will keep afternoon high temperatures in the middle to upper
30s.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 314 AM CST MON FEB 15 2016
The next fast-moving storm system embedded within the prevailing
northwesterly flow aloft will arrive late tonight into Tuesday,
bringing another period of wintry precip to central Illinois. 00z
Feb 15 models have all trended south with the track of this system,
with the NAM being the furthest north and the GEM the furthest
south. Have rejected these two solutions in favor of the middle
of the road GFS, which takes the 500mb vort max from northern
Missouri 12z Tue to far southern Illinois by 18z Tue. Given this
particular track, the heaviest precip will be focused across the
central/southern CWA. Have therefore reduced PoPs into the
chance category along/north of I-74...while maintaining likely
further south across the remainder of the area. Another
consequence of a further south track is a slightly colder thermal
profile. GFS forecast soundings are generally cold enough for
snow initially as the max temp in the elevated warm layer only
reaches about 1C. As a result, am expecting snow Tuesday
morning, gradually transitioning to a rain/snow mix by afternoon
as surface temps rise into the middle to upper 30s. Due to the
southward track shift, relatively light precip, and marginal
temps...snow accumulations are expected to remain minor. Will
see a band of around 1 inch along/southwest of a Canton...to
Decatur...to Marshall line...with less than one half inch north of
I-74.
Another weak short-wave will pass through the region on Wednesday:
however, this feature will be moisture-starved and will produce
little more than some cloud cover. Once this wave exits, upper
heights will begin to rise in earnest in response to a major
system coming onshore along the Pacific Coast. Downstream
ridging across the central and eastern CONUS will allow a
pronounced warming trend to occur by the end of the week. Models
have been consistently advertising temps reaching the upper 40s
and lower 50s by Thursday, then climbing into the upper 50s and
lower 60s on Friday. A weak cold front is still progged to pass
through Illinois on Friday, but with only limited moisture to work
with, will only mention slight chance for showers with FROPA.
After that, temps cool a bit over the weekend, but remain above
normal in the 50s for both Saturday and Sunday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 510 AM CST MON FEB 15 2016
IFR to VLIFR conditions in low clouds and vsbys expected through
at least 16z before conditions slowly improve into the afternoon
hours. Widespread IFR and LIFR conditions prevailed early this
morning due to high moisuture levels in the low levels of the
atmosphere. Weak high pressure will push across the area today
with forecast soundings indicating a low level inversion in
place effectively trapping the moisture through early this
afternoon. Will start to take the cigs up above 1000 feet after
16-18z but confidence on that occurring is low at this particular
time. Latest short term guidance suggests the lowest vsbys will be
along and especially south of I-72 which should include SPI and
DEC. However, experience has shown that with these light southerly
flow regimes, coupled with a fresh snow cover, BMI has a tendency
to stay rather low with the cigs and vsbys and is slow to recover.
Will trend in that direction thru at least the morning hours.
IFR with some low MVFR cigs expected this evening and overnight
with the next weather system moving in after 08z, and affecting
mainly the SPI TAF. At this point, will include a VCSH with a
threat for some light snow developing before dawn. Surface winds
will not be much of a factor through tonight with a light
southerly to southwesterly flow today with speeds of less than
10 kts, becoming light south to southeast late tonight.
&&
.ILX Watches/Warnings/Advisories...
Dense Fog Advisory until noon CST today for ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Paducah KY
1140 AM CST MON FEB 15 2016
.UPDATE...
Issued at 1140 AM CST MON FEB 15 2016
The AVIATION section has been updated for the 18Z TAF issuance.
&&
.SHORT TERM...(Today through Wednesday)
Issued at 255 AM CST MON FEB 15 2016
Scattered light showers continue to stream northeast just clipping
southeastern Todd county Kentucky, but based on the KCKV and KBWG
METARs this area should be just above freezing. Will therefore
let the Winter Weather Advisory expire as scheduled at 3 AM.
Elsewhere across the forecast area, most observation sites have
visibilities between 1 and 3 miles with light fog, and a few
patches of very light freezing drizzle. Weak, drizzly echoes on
radar at Midnight have mostly dried up, so doubt there will be
much, if any, additional icing this morning. However, will re-
issue an SPS mainly to highlight slick driving conditions through
the morning commute.
The 00Z WRF and most recent HRRR runs keep the shower activity
along the TN border through the morning, and then lift it back up
over more of west Kentucky this afternoon before pushing east of
the area early this evening. Given this timing, temperatures
should be above freezing, so there should be no wintry concerns
after the sun gets sufficiently high in the sky this morning.
The 00Z models bring a compact, intense upper low into the base of
the upper trough over the region on Tuesday. The 00Z consensus
keeps any QPF northwest of the area through daybreak, but we will
have to watch for the potential for either freezing rain or snow
with the onset of precipitation in the morning. Model soundings
across the northeast show a warm layer only near the surface, so
it is conceivable that we will have to monitor for snow through
the day as this system passes. Temperatures should be above
freezing, so accumulations will be hard to come by even if the
snow reaches the ground. This system should exit to the east at or
shortly after 00Z Wednesday.
Yet another upper-level disturbance will dive southeast into our
region for Wednesday, as we continue to be heavily influenced by
cyclonic flow aloft. The models are not generating any
precipitation with this activity, but it should keep most of the
area rather cloudy.
.LONG TERM...(Wednesday Night through Sunday)
Issued at 255 AM CST MON FEB 15 2016
By Wednesday into Thursday, we will finally be seeing a shift in the
upper level pattern, as an upper level ridge builds overhead. As
this occurs, we will see quiet weather along with a decent warmup,
that has been advertised for quite a while now. Warm air advection
will begin in earnest Wednesday night and the entire area will see
850mb temps back above zero by late Thursday morning or afternoon.
We should see highs on Thursday well into the 50s per the latest
guidance, 2m temps and soundings. We should see 60s by Friday with
our far western counties in SEMO maybe touching or getting close to
70 degrees. In fact, even warmer weather will only be a state away,
as newest guidance indicating highs around 80 in northeast Oklahoma.
Hard to imagine when you`re currently only sitting at 31 degrees.
Meanwhile, in the northern Plains, an upper level shortwave will be
moving eastward into the Great Lakes Thursday night into Friday. As
this occurs, a weak front at the surface will be moving into our
area. Moisture still appears to be rather scant but the GFS still
tries to eek out some QPF. Whatever does fall, if anything, will be
light. But since POPS have already been taken out, will continue
with that idea and leave it dry, but will have to keep watching, as
the GFS ensembles continue to indicate a few hundredths of QPF with
the FROPA.
The front dives south but only makes into the Gulf Coast State
before stalling out. Models indicate that the front will lift back
north toward the area as early as Saturday night. However, Saturday
should be a dry day with temperatures remaining in the 60s. Another
weak frontal boundary will develop to our west and will move through
on Sunday, which means we will continue with the chance for rain.
The front should be exiting the area sometime on Sunday night. Could
even see some isolated thunderstorms on Saturday night into Sunday
as some of the parameters are hinting at it.
&&
.AVIATION...
Issued at 1140 AM CST MON FEB 15 2016
Abundant low level moisture coupled with a very strong inversion
have produced LIFR/IFR conditions across all sites today. We
expect slight improvements later this afternoon and into the early
overnight hours. Beyond that cigs/vsbys are expected to drop back
to LIFR/IFR along with the possibility of light FZDZ. FZDZ should
only last a couple of hours and quickly change to rain before the
end of the period. Winds calm to light and variable will come
around to the southeast AOB 5 knots by the end of the period.
&&
.PAH Watches/Warnings/Advisories...
IL...Dense Fog Advisory until 2 PM CST this afternoon for ILZ077-078-
082-083-085>094.
MO...Dense Fog Advisory until 2 PM CST this afternoon for MOZ110>112-
114.
IN...Dense Fog Advisory until 2 PM CST this afternoon for INZ081-082-
085>088.
KY...Dense Fog Advisory until 2 PM CST this afternoon for KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...CW
AVIATION...JP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
359 PM CST MON FEB 15 2016
.SHORT TERM...THE NEXT 3 TO 5 HOURS WILL BE THE MOST ACTIVE OF
THE ENTIRE FORECAST PERIOD. CURRENT SURFACE ANALYSIS SHOWS THE LOW
CENTER IN CENTRAL MISSISSIPPI EAST OF JACKSON CONTINUING TO DEEPEN
WITH A PRESSURE OF NEAR 1005MB. APPENDANT COLD FRONT EXTENDS FROM
THERE THROUGH HATTIESBURG AND HAMMOND...THEN BACK WEST TO JUST
SOUTH OF BATON ROUGE. THUS THE MAJORITY OF THE FORECAST AREA
REMAINS IN THE WARM SECTOR. BASED ON MID MORNING SOUNDING...THIS
AREA IS VERY BUOYANT AND FULL OF INSTABILITY ON THE ORDER OF 1500
TO 2000 J/KG OF CAPE. MUCH HIGHER THAN MODEL SOUNDINGS SUGGESTED
IN PREVIOUS DAYS. ADDITIONALLY...THE WET BULB ZERO HEIGHT WAS
AROUND 9KFT WHICH IS VERY LOW AND THE MAIN REASON FOR THE
WIDESPREAD HAIL THAT`S BEEN OBSERVED TODAY. THE KLIX VAD SHOWS
VERY STRONG WINDS THROUGHOUT THE COLUMN...ON THE ORDER OF 50 KNOTS
FROM 5KFT TO OVER 40KFT. THIS IS CREATING ENOUGH SHEAR FOR SOME
STORMS TO ROTATE. LOCATIONS SOUTH OF INTERSTATE 10...ALTHOUGH IN
HIGHER MOISTURE...LIKELY BEING CAPPED DUE TO COOLER GULF WATER
TEMPS. THE REST OF THE AREA HAS THE POTENTIAL TO BE IMPACTED BY
STRONG TO SEVERE STORMS AHEAD OF THE FRONT AND THEN ALONG THE
ACTUAL BOUNDARY AS IT PROGRESSES EASTWARD. THE HRRR HAS BEEN QUITE
GOOD WITH TIMING AND PROGRESSION OF THE SYSTEM TODAY...SO BASED ON
THAT...SHOULD SEE THE BACK EDGE OF THE THUNDERSTORMS PUSHING
OFFSHORE IN THE 01-02Z TIME FRAME. CLEARER SKIES WILL BE DELAYED
BY A FEW HOURS BUT MOST OF THE CWA SHOULD BE CLOUD FREE AFTER
MIDNIGHT.
.LONG TERM... POST FRONTAL HIGH PRESSURE COMING FROM THE WEST
TUESDAY WILL NOT HAVE MUCH IN THE WAY OF COOLER TEMPS WITH THAT AIR
MASS...JUST DRY CONDITIONS. SO WILL EXPERIENCE WARMER TEMPS TUESDAY.
THE TREND WILL CONTINUE THROUGHOUT THE WEEK AND INTO THE WEEKEND AS
UPPER LEVEL RIDGE TRACKS FROM WEST TO EAST ACROSS THE CWA. MOST
GUIDANCE DID SUGGEST COOLER TEMPS THIS MODEL RUN BUT THATS DIFFERENT
FROM THE LAST SEVERAL DAYS IN A ROW...SO NOT MAKING ANY CHANGES TO
THE EXTENDING FORECAST TEMPS. HIGHS WILL MODERATE INTO THE MID 70S
FRIDAY ONWARD.
MEFFER
&&
.AVIATION...MOST TERMINALS TO BE IMPACTED BY RAIN AND THUNDERSTORMS
OVER THE NEXT FEW HOURS. VISIBILITIES WILL DROP TO 3 MILES OR LESS
WITH HEAVIER RAIN AND GUSTS UP TO 40 KNOTS POSSIBLE WITH STRONGER
STORMS. CLEARING LINE SHOULD REACH THE COAST BY 02Z THIS EVENING.
AREAS OF LIGHT TO MODERATE FOG WITH MVFR VIS POSSIBLE BETWEEN 06Z
AND 12Z.
MEFFER
&&
.MARINE...1005MB SURFACE LOW HAS CAUSED GRADIENT WINDS TO RISE TO 15
TO 25 KNOTS. THESE STRONG SOUTHEAST WINDS WILL ABRUPTLY SHIFT TO NW
AS THE COLD FRONT PUSHES THROUGH. OTHER THAN A BRIEF BURST OF WINDS
RIGHT ALONG THE BOUNDARY...GRADIENT PRE-FRONTAL APPEARS STRONGER
THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION. THIS SHOULD REDUCE
THE WINDS TO JUST SCS LEVELS TONIGHT AND TUESDAY. WINDS AND SEAS
SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES WITH BETTER COLD AIR
ADVECTION LATE THURSDAY INTO FRIDAY.
MEFFER
&&
.DECISION SUPPORT...
DSS CODE....YELLOW.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND
MISSISSIPPI RIVER AT RED RIVER LANDING.
WATCHES AND WARNINGS IN EFFECT.
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 42 71 43 71 / 10 0 0 0
BTR 45 73 47 73 / 10 0 0 0
ASD 43 71 44 70 / 10 0 0 0
MSY 50 68 50 69 / 10 0 0 0
GPT 45 67 45 69 / 20 0 0 0
PQL 42 69 45 69 / 40 10 10 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ532-536-
538-552-555-557-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538-
552-555-557-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1142 AM CST MON FEB 15 2016
.AVIATION...
THUNDERSTORMS EXTEND FROM AVOYELLES PARISH SOUTHWEST INTO
JEFFERSON COUNTY IN SOUTHEAST TEXAS. THIS BROKEN LINE IS MOVING
EAST. AIRCRAFT NEAR THESE STORMS WILL EXPERIENCE LIGHTNING ALONG
WITH GUSTY WINDS IN AND NEAR AIRPORT TAF LOCATIONS. CONDITIONS
ARE EXPECTED TO IMPROVE TOWARDS SUNSET AS A COLD FRONT PUSHES DOWN
AND INTO THE REGION. CEILINGS ARE ALSO VARYING FROM 016 TO 045 BUT
THIS WILL ALSO IMPROVE BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 1020 AM CST MON FEB 15 2016/
UPDATE...
TORNADO WATCH 14 HAS BEEN ISSUED UNTIL 6 PM.
DISCUSSION...
UPDATED TEXT PRODUCTS TO INCLUDE TOR WATCH 14. LATEST RADAR TRENDS
INDICATE A BAND OF STRONG TO SVR STORMS EXTENDING FM AVOYELLES
PARISH SW TO SABINE LAKE. THESE STORMS WERE DEVELOPING IN AN
ENVIRONMENT CONDUCIVE FOR ROTATING STORMS...WITH 0-1 KM SRH NR
215 M2/S2...30 KT LOW LVL SHEAR AND DEEP LAYER SHEAR APPROACHING
50 KT PER 12Z KLCH SOUNDING. IN ADDITION...DECENT INSTABILITY IS
IN PLACE WITH MUCAPE VALUES APPROACHING 2000 J/KG AND THIS SHOULD
INCREASE ESPECIALLY ACRS ERN PORTIONS OF THE AREA AS THE BAND OF
STORMS ENCOUNTERS DAYTIME HEATING. ALL SVR MODES...LARGE
HAIL/DAMAGING WINDS/TORNADOES...WILL BE POSSIBLE.
RECENT HRRR RUNS SEEM TO HAVE A DECENT HANDLE ON THE CONVECTION
AND ITS EVOLUTION THROUGH THE AFTN SO BLENDED WITH INHERITED POPS
TO ADJUST. ALSO AMENDED WX GRIDS TO REFLECT SVR POTENTIAL ACRS
OUR LA ZONES THROUGH THE REMAINDER OF THE MORNING AND AFTN.
FINALLY...TWEAKED HOURLY TEMPERATURES AND DEWPOINTS TO REFLECT
RECENT OBS. ALSO ADJUSTED HIGH TEMPERATURES DOWN SLIGHTLY ACRS
OUR NERN ZONES WHERE CLOUDS AND SHOWERS/STORMS WILL LIKELY LIMIT
HEATING.
24
PREV DISCUSSION... /ISSUED 749 AM CST MON FEB 15 2016/
DISCUSSION...
BASED ON LATEST SPC DISCUSSION...AND CURRENT RADAR TRENDS...HAVE
ADDED SEVERE STORM WORDING TO THE FORECAST FOR TODAY FOR THE
ENTIRE FORECAST AREA. THE THREAT WILL END FROM WEST TO EAST THIS
AFTERNOON.
PREV DISCUSSION... /ISSUED 542 AM CST MON FEB 15 2016/
DISCUSSION...
SCT SHRA WITH ISO TSRA ACROSS THE REGION THIS MORNING. MVFR TO IFR
CEILINGS WITH VCSH EXPECTED TO PERSIST THIS MORNING. BEST CHANCE
OF TSRA WILL BE LATER THIS MORNING INTO THE EARLY AFTERNOON
HOURS...KEEPING TEMPO GROUP FOR THIS FROM 16-20Z. ALSO...S TO SW
WINDS EXPECTED TO PICK UP AS WELL DURING THIS TIME ~18-20KTS WITH
GUSTS TO NEAR 30 KT. HIGHER GUSTS POSSIBLE WITHIN THE TSRA...AS
HIGHLIGHTED WITHIN TEMPO GROUPS. AFTER 20-22Z...FRONTAL SYSTEM
PASSING THRU...WITH WINDS SHIFTING TO THE WEST AND THEN NW DURING
THE EVENING HOURS...WITH CLEARING SKIES AND VFR TO FOLLOW.
DML
PREV DISCUSSION... /ISSUED 313 AM CST MON FEB 15 2016/
DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE MOVING NORTHEAST
ACROSS THE ENTIRE FORECAST AREA EARLY THIS MORNING...THANKS TO A
FAST-MOVING MID-LEVEL SHORTWAVE. A COLD FRONT AND CORRESPONDING
MID TO UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION RATHER
QUICKLY THIS AFTERNOON. PER SPC...SOME OF THE STORMS THIS
AFTERNOON COULD BE STRONG TO SEVERE...WITH DAMAGING WINDS AND
LARGE HAIL THE PRIMARY THREATS...ESPECIALLY IN SOUTH CENTRAL
LOUISIANA WHERE A SLIGHT RISK IS NOTED.
AFTER THE RAIN ENDS THIS AFTERNOON...THE WEATHER MAPS TURNS QUIET
FOR THE REMAINDER OF THE WEEK. A SECOND COLD FRONT DOES MOVE
THROUGH THE REGION LATE TUESDAY...BUT IT IS EXPECTED TO BE DRY
WITH LIMITED TO NO MOISTURE AVAILABLE. THE NEXT RAIN MAKER WILL BE
SUNDAY AND MONDAY...WHEN THE NEXT FRONT COMES THROUGH THE REGION.
THIS WEEK WILL SEE TEMPERATURES RUN ABOVE NORMAL WITH HIGHS IN THE
70S. LOWS WILL START OUT IN THE 40S TUESDAY AND WEDNESDAY MORNINGS
BEFORE WARMING INTO THE 50S FOR THE REMAINDER OF THE WEEK AND
WEEKEND.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 44 74 45 72 / 10 0 0 0
LCH 48 74 49 73 / 10 0 0 0
LFT 48 72 49 73 / 10 0 0 0
BPT 49 76 49 73 / 10 0 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1020 AM CST MON FEB 15 2016
.UPDATE...
TORNADO WATCH 14 HAS BEEN ISSUED UNTIL 6 PM.
&&
.DISCUSSION...
UPDATED TEXT PRODUCTS TO INCLUDE TOR WATCH 14. LATEST RADAR TRENDS
INDICATE A BAND OF STRONG TO SVR STORMS EXTENDING FM AVOYELLES
PARISH SW TO SABINE LAKE. THESE STORMS WERE DEVELOPING IN AN
ENVIRONMENT CONDUCIVE FOR ROTATING STORMS...WITH 0-1 KM SRH NR
215 M2/S2...30 KT LOW LVL SHEAR AND DEEP LAYER SHEAR APPROACHING
50 KT PER 12Z KLCH SOUNDING. IN ADDITION...DECENT INSTABILITY IS
IN PLACE WITH MUCAPE VALUES APPROACHING 2000 J/KG AND THIS SHOULD
INCREASE ESPECIALLY ACRS ERN PORTIONS OF THE AREA AS THE BAND OF
STORMS ENCOUNTERS DAYTIME HEATING. ALL SVR MODES...LARGE
HAIL/DAMAGING WINDS/TORNADOES...WILL BE POSSIBLE.
RECENT HRRR RUNS SEEM TO HAVE A DECENT HANDLE ON THE CONVECTION
AND ITS EVOLUTION THROUGH THE AFTN SO BLENDED WITH INHERITED POPS
TO ADJUST. ALSO AMENDED WX GRIDS TO REFLECT SVR POTENTIAL ACRS
OUR LA ZONES THROUGH THE REMAINDER OF THE MORNING AND AFTN.
FINALLY...TWEAKED HOURLY TEMPERATURES AND DEWPOINTS TO REFLECT
RECENT OBS. ALSO ADJUSTED HIGH TEMPERATURES DOWN SLIGHTLY ACRS
OUR NERN ZONES WHERE CLOUDS AND SHOWERS/STORMS WILL LIKELY LIMIT
HEATING.
24
&&
.PREV DISCUSSION... /ISSUED 749 AM CST MON FEB 15 2016/
DISCUSSION...
BASED ON LATEST SPC DISCUSSION...AND CURRENT RADAR TRENDS...HAVE
ADDED SEVERE STORM WORDING TO THE FORECAST FOR TODAY FOR THE
ENTIRE FORECAST AREA. THE THREAT WILL END FROM WEST TO EAST THIS
AFTERNOON.
PREV DISCUSSION... /ISSUED 542 AM CST MON FEB 15 2016/
DISCUSSION...
SCT SHRA WITH ISO TSRA ACROSS THE REGION THIS MORNING. MVFR TO IFR
CEILINGS WITH VCSH EXPECTED TO PERSIST THIS MORNING. BEST CHANCE
OF TSRA WILL BE LATER THIS MORNING INTO THE EARLY AFTERNOON
HOURS...KEEPING TEMPO GROUP FOR THIS FROM 16-20Z. ALSO...S TO SW
WINDS EXPECTED TO PICK UP AS WELL DURING THIS TIME ~18-20KTS WITH
GUSTS TO NEAR 30 KT. HIGHER GUSTS POSSIBLE WITHIN THE TSRA...AS
HIGHLIGHTED WITHIN TEMPO GROUPS. AFTER 20-22Z...FRONTAL SYSTEM
PASSING THRU...WITH WINDS SHIFTING TO THE WEST AND THEN NW DURING
THE EVENING HOURS...WITH CLEARING SKIES AND VFR TO FOLLOW.
DML
PREV DISCUSSION... /ISSUED 313 AM CST MON FEB 15 2016/
DISCUSSION...
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE MOVING NORTHEAST
ACROSS THE ENTIRE FORECAST AREA EARLY THIS MORNING...THANKS TO A
FAST-MOVING MID-LEVEL SHORTWAVE. A COLD FRONT AND CORRESPONDING
MID TO UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION RATHER
QUICKLY THIS AFTERNOON. PER SPC...SOME OF THE STORMS THIS
AFTERNOON COULD BE STRONG TO SEVERE...WITH DAMAGING WINDS AND
LARGE HAIL THE PRIMARY THREATS...ESPECIALLY IN SOUTH CENTRAL
LOUISIANA WHERE A SLIGHT RISK IS NOTED.
AFTER THE RAIN ENDS THIS AFTERNOON...THE WEATHER MAPS TURNS QUIET
FOR THE REMAINDER OF THE WEEK. A SECOND COLD FRONT DOES MOVE
THROUGH THE REGION LATE TUESDAY...BUT IT IS EXPECTED TO BE DRY
WITH LIMITED TO NO MOISTURE AVAILABLE. THE NEXT RAIN MAKER WILL BE
SUNDAY AND MONDAY...WHEN THE NEXT FRONT COMES THROUGH THE REGION.
THIS WEEK WILL SEE TEMPERATURES RUN ABOVE NORMAL WITH HIGHS IN THE
70S. LOWS WILL START OUT IN THE 40S TUESDAY AND WEDNESDAY MORNINGS
BEFORE WARMING INTO THE 50S FOR THE REMAINDER OF THE WEEK AND
WEEKEND.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 66 44 74 45 / 80 10 0 0
LCH 72 48 74 49 / 70 10 0 0
LFT 72 48 72 49 / 90 10 0 0
BPT 74 49 76 49 / 60 10 0 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST MON FEB 15 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 406 PM EST MON FEB 15 2016
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE ALONG THE W COAST
OF THE CONUS/CANADA AND A DOWNSTREAM TROF OVER CNTRL/ERN N AMERICA
WITH AXIS GENERALLY FROM THE WRN GREAT LAKES TO THE LWR MISSISSIPPI
VALLEY. SHORTWAVE TROF THAT BROUGHT SOME -SN TO THE AREA LAST
NIGHT/THIS MORNING HAS SHIFTED E OF THE AREA. KGRB RADAR AND SFC
OBS/WEBCAMS SHOWED A BAND OF LAKE ENHANCED SNOW ALONG SFC TROF THAT
MOVED OUT ACROSS LAKE MI LATE LAST NIGHT/THIS MORNING. AT LEAST AT
LOCATIONS WITH WEBCAMS...IT DID NOT APPEAR THAT THERE WAS MORE THAN
2-3 INCHES OF SNOW WITH THE LAKE ENHANCEMENT...BUT THERE CERTAINLY
COULD HAVE BEEN SOME ISOLATED HIGHER AMOUNTS. SOME -SN STILL LINGERS
IN THE VCNTY OF THE WEAKENING TROF WHICH IS NOW INTO LUCE COUNTY. TO
THE W...THERE HAVE BEEN SCT FLURRIES...BUT LATEST KMQT RADAR
SUGGESTS THE FLURRIES HAVE MOSTLY DISSIPATED. UPSTREAM...NEXT
SHORTWAVE OF INTEREST IS IN NRN MANITOBA/NRN SASKATCHEWAN.
A GENERALLY QUIET EVENING IS EXPECTED. LINGERING -SN OVER THE FAR E
WILL END THIS EVENING AS SFC TROF DRIFTS E AND WINDS BECOME WSW
ACROSS NRN LAKE MI. THERE MAY BE A FEW FLURRIES ELSEWHERE...
ESPECIALLY IF SMALL AREA OF -SHSN/FLURRIES OVER NE MN HOLDS
TOGETHER. OVERNIGHT...AS SHORTWAVE IN MANITOBA/SASKATCHEWAN DROPS
SE...THERE IS AN INCREASE IN MOISTURE DEPTH AND DEEP LAYER FORCING
PER QVECTORS INTO THE WRN FCST AREA. WITH MOST MODELS GENERATING
SOME PCPN...GRADUALLY INCREASED POPS THRU THE CHC CATEGORY OVER THE
W OVERNIGHT. AS FOR TEMPS...WHILE CLOUDS SHOULD PERSIST ACROSS THE
BOARD TONIGHT AND HOLD TEMPS UP...THERE IS SOME CONCERN THAT CLOUDS
COULD BREAK FOR A TIME OVER PORTIONS OF THE CNTRL AND ERN FCST AREA
WHERE LIGHT DOWNSLOPING OCCURS. THE BIAS CORRECTED REGIONAL AND
GLOBAL CANADIAN MODELS WHICH ARE OFTEN SUPERIOR PERFORMERS WITH
RADIATIONAL COOLING INDICATE MIN TEMPS DOWN INTO THE LWR SINGLE
DIGITS FROM PARTS OF MENOMINEE COUNTY EASTWARD...WITH SOME TEMPS SUB
ZERO TEMPS IN SCHOOLCRAFT COUNTY. FOR NOW...LOWERED TEMPS SLIGHTLY
DOWN TOWARD 10F OVER PORTIONS OF THE ERN FCST AREA.
ON TUE...AFOREMENTIONED SHORTWAVE SWINGS INTO THE UPPER GREAT LAKES
WITH ASSOCIATED COLD FRONT REACHING THE KEWEENAW LATE MORNING/EARLY
AFTN AND EXITING THE SE FCST AREA LATE AFTN/EARLY EVENING. BAND OF
DEEP LAYER FORCING/DEEP MOISTURE WHICH BEGINS TO ARRIVE OVER THE W
LATE TONIGHT SHIFTS ACROSS THE FCST AREA ON TUE. AS A RESULT...MOST
AREAS SHOULD SEE SOME -SN AT SOME POINT TUE. UTILIZED CHC POPS.
EXPECT A BURST OF HEAVIER SNOW TO ACCOMPANY COLD FRONT AS IT DROPS
SSE ACROSS LAKE SUPERIOR AND INTO UPPER MI AS 850MB TEMPS ARE JUST
COLD ENOUGH TO SUPPORT LAKE ENHANCEMENT. AS A RESULT...INCLUDED A
SHORT PERIOD OF LIKELY POPS ALONG THE COLD FRONT AND INTO WRN/NRN
UPPER MI WITH SNOW ACCUMULATIONS OF 1-2 INCHES NEAR THE LAKE.
ELSEWHERE...ANY SNOW ACCUMULATION WILL BE UNDER 1 INCH. PATCHY BLSN
SHOULD DEVELOP CLOSE TO THE LAKE FROM THE KEWEENAW EASTWARD AFTER
FROPA. WITH AN OPPORTUNITY TO WARM UP PRIOR TO FROPA...TEMPS SHOULD
TOP OUT AROUND 30F ACROSS THE FCST AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 314 PM EST MON FEB 15 2016
A 500MB TROUGH WILL BE SET UP ACROSS MUCH OF THE E THIRD OF THE
NATION THROUGH WEDNESDAY. EXPECT ANOTHER BLAST OF COLD AIR TO SWING
IN ON N WINDS TUESDAY NIGHT/WEDNESDAY...WITH 850MB TEMPS AVERAGING
-16C. ACCOMPANYING THIS COLD AIR WILL BE ANOTHER SHORTWAVE TUESDAY
NIGHT...AND INCREASED NNW WINDS...WHICH WILL COMBINE TO HELP CREATE
SNOW AND BLOWING SNOW OVER THE KEWEENAW PENINSULA THROUGH WHITEFISH
POINT. WILL CONTINUE TO MENTION THE POTENTIAL FOR LIGHT-MODERATE
SNOW AND BLOWING SNOW IN THE HWO BEFORE WINDS DIMINISH W-E WEDNESDAY
MORNING AS THE SFC HIGH SHIFTS OVERHEAD. HIGHS WEDNESDAY WILL
STRUGGLE TO GET OUT OF THE TEENS.
LOOK FOR THE 500MB RIDGE CURRENTLY PUSHING INTO THE W SEABOARD TO
SHIFT E...AND BE CENTERED ACROSS THE PLAINS STATES THURSDAY MORNING.
IT WILL BE A RACE TO SEE HOW LOW TEMPERATURES CAN FALL BEFORE HIGH
CLOUDS NEAR FROM THE NW AND WAA TAKES COLD ON INCREASED S-SW WINDS
THURSDAY MORNING AS 850MB TEMPS WARM TO AROUND -8C BY DAYBREAK
THURSDAY. SINGLE DIGIT LOWS STILL LOOK REASONABLE. THE WAA WILL ALSO
PUT AN END TO THE LES OFF E LAKE SUPERIOR EARLY WEDNESDAY EVENING.
THE 500MB RIDGE WILL SWIFTLY SLIDE OVER THE GREAT LAKES REGION
THURSDAY AFTERNOON/THURSDAY EVENING. LOOK FOR A TEMPORARY BREAK FROM
THE SNOW...ALTHOUGH WAA SNOW MAY RETURN WITH THE PASSAGE OF THE WARM
FRONT THURSDAY EVENING. MIXED PRECIP WILL BE A CONCERN. BY 00Z
FRIDAY 850MB WINDS OUT OF THE S AT 40-55KT WILL HELP USHER 850MB
TEMPS OF -3 TO +3C OVER THE CWA. THERE ARE ENOUGH DIFFERENCES IN THE
FCST MODELS AT THIS DISTANCE TO GIVE MODERATE TO LOW CONFIDENCE IN
SPECIFIC PRECIP TYPES...ALTHOUGH SNOW...FREEZING RAIN...AND RAIN
WILL ALL BE POSSIBLE AT SOME POINT THURSDAY NIGHT INTO FRIDAY
MORNING. WILL KEEP THE MENTION OF A WINTRY MIX OF PRECIP IN THE HWO.
THAT WILL BE UNTIL SFC TEMPS WARM UP ENOUGH FOR MOST OF THE PRECIP
TO FALL IN THE FORM OF RAIN. THE 00Z ECMWF AND 06Z GFS WERE FAIRLY
IN LINE WITH SLIDING THE NEARING SFC LOW OVER MN EARLY FRIDAY
MORNING...CROSSING UPPER MI/N LAKE MI DURING THE DAY...AND EXITING
ACROSS LAKE HURON FRIDAY EVENING. THE 06Z CANADIAN MODEL WAS MUCH
FARTHER TO THE N WITH THE LOW...WHICH WAS BACKED BY THE ECMWF
YESTERDAY. OVERALL...THE GFS HAS BEEN MORE CONSISTENT OVERALL WITH
THE TRACK. THE 12Z SOLUTIONS ARE COMING IN WITH AT LEAST SOME BETTER
AGREEMENT ON THE TRACK OF THE LOW NEAR LAKE SUPERIOR FRIDAY
AFTERNOON-EVENING...BUT STILL PLENTY OF TIME FOR CHANGES.
COLDER AIR WILL FILTER IN BEHIND THE EXITING SFC LOW FRIDAY NIGHT.
JUST HOW COLD IS ANOTHER QUESTION...AS THE GFS AND
ECMWF VARY BY AROUND 5C...RANGING FROM -9C TO -2C /COLDEST OFF THE
ECMWF/ BY 12Z SATURDAY. THIS COULD MAKE THE DIFFERENCE IN ALL SNOW
OR LINGERING RAIN/SNOW MIX INLAND SATURDAY MORNING. W-NW WINDS WILL
BE THE RULE FROM 00Z SATURDAY-00Z SUNDAY.
WILL RUN WITH A BLENDED MODEL SOLUTION FOR SATURDAY NIGHT THROUGH
NEXT MONDAY...AS THE NEXT 500MB TROUGH DIVES IN. THE SMALL SCALE
DIFFERENCES ARE GOING TO BE DIFFICULT TO PERFECT AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1233 PM EST MON FEB 15 2016
MVFR CIGS WILL LIKELY CONTINUE AT KIWD THRU THE AFTN GIVEN THE LOW
CLOUDS UPSTREAM ACROSS NW WI/MN. AT KCMX...EXPECT VFR CIGS TO FALL
TO MVFR THIS AFTN AS LOWER CLOUDS TO THE W AND SW SPREAD INTO THE
AREA. SIMILAR SITUATION SHOULD OCCUR AT KSAW...BUT LATER IN THE
AFTN/EARLY EVENING. FCST FOR TONIGHT WILL BE CHALLENGING AS LARGER
SCALE SUBSIDENCE/LOWERING INVERSION IN THE PRESENCE OF NOCTURNAL
COOLING MAY BRING ABOUT IFR CIGS. FOR NOW...LOWERED CIGS TO LOW MVFR
WITH IFR DEVELOPING LATE OVERNIGHT/EARLY MORNING AT KIWD/KCMX...
PARTLY IN RESPONSE TO SOME -SN SPREADING INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 PM EST MON FEB 15 2016
WITH A WEAKENING PRES GRADIENT OVER THE UPPER LAKES...WINDS ACROSS
LAKE SUPERIOR WILL DIMINISH TO UNDER 20KT TONIGHT INTO TUE MORNING.
PASSAGE OF A COLD FRONT ON TUE AND TIGHTENING PRES GRADIENT AHEAD OF
HIGH PRES BUILDING INTO MANITOBA WILL BRING A PERIOD OF STRONGER N
WINDS UP TO 30KT TUE AFTN/NIGHT...WITH THE STRONGEST WINDS OVER THE
CNTRL AND ERN PORTIONS OF LAKE SUPERIOR LATE TUE AFTN/EVENING. THERE
MAY BE A FEW GALE FORCE GUSTS. IN ADDITION...EXPECT SOME HEAVY
FREEZING SPRAY TO DEVELOP OVER PORTIONS OF CENTRAL LAKE SUPERIOR.
WINDS WILL DIMINISH TO UNDER 20KT WED AS HIGH PRES ARRIVES OVER THE
UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU
UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND
ANOTHER APPROACHING LOW PRES. WINDS MAY INCREASE FURTHER TO GALES
THU NIGHT OVER THE E HALF OF LAKE SUPERIOR. THE LOW WILL PASS OVER
OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL
THEN FOLLOW INTO FRI NIGHT AND SAT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1243 PM EST MON FEB 15 2016
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EST MON FEB 15 2016
SEVERAL WEAK LOW PRESSURE SYSTEMS WILL TAKE AIM AT THE GREAT
LAKES...BUT MOSTLY MISS. THE ONGOING LIGHT SNOW OVER LOWER
MICHIGAN WILL DIMINISH TODAY. ANOTHER LOW WILL PASS MOSTLY SOUTH
OF LOWER MICHIGAN TUESDAY. MUCH WARMER AIR IS A STRONG POSSIBILITY
FRIDAY AHEAD OF A LOW MOVING ACROSS THE UP. WE MAY END UP SEEING
RAIN WITH THAT SYSTEM.
&&
.UPDATE...
ISSUED AT 1157 AM EST MON FEB 15 2016
SYSTEM SNOW IS STARTING TO PIVOT OUT OF THE FORECAST AREA AS WE
APPROACH NOON...BUT THERE IS A FINAL BURST MOVING THROUGH CENTRAL
LOWER MI. THE SNOW IS ASSOCIATED WITH A MID LEVEL SHORTWAVE TROUGH
THAT WILL MOVE EAST OF THE AREA THROUGH THE COURSE OF THE
AFTERNOON AND EARLY EVENING HOURS. ANY ADDITIONAL ACCUMULATION
TODAY WILL BE LESS THAN AN INCH.
AS THE MID LEVEL MOISTURE PULLS AWAY AND THERE IS A BIT OF LIFT
LEFT IN THE PROFILE WE MAY CONTINUE TO SEE PATCHY FREEZING
DRIZZLE. CURRENT THINKING IS THAT THIS THREAT IS PRETTY MINIMAL
AND ITS OCCURRENCE SHOULD BE WAINING.
FINAL ITEM OF NOTE IS A BAND OF LAKE EFFECT SNOW OUT OVER LAKE
MICHIGAN. IT IS NOT WELL SEEN AND WE ARE LIKELY OVERSHOOTING IT
FROM THE KGRR RADAR. MULTIPLE RUNS OF THE HRRR HAVE SHOWN THIS
BAND COMING ASHORE BETWEEN 18Z-21Z ACROSS WEST CENTRAL LOWER MI.
THE FLOW BEHIND THE SHORTWAVE WILL SHIFT TO THE SOUTHWEST WHICH
WILL BRING THE BAND ON SHORE. THERE WILL BE A LOCAL BURST TO THE
SNOW AND VISIBILITY WILL BE AFFECTED. COULD SEE A LOCAL INCH OR SO
FROM THIS BAND BEFORE IT MOVES INLAND AND DISSIPATES AFTER
20Z-21Z.
PLENTY OF CLOUDS HANG ON TODAY WITH TEMPERATURES RELEGATED TO THE
20S FOR HIGHS.
UPDATE ISSUED AT 759 AM EST MON FEB 15 2016
HAVE ISSUED AN UPDATE TO INCLUDE A CHANCE OF FREEZING DRIZZLE
MAINLY ALONG AND SOUTH I-96. THIS IS BASED ON THE RECENT ARRIVAL
OF LOWER CEILINGS OF 500-900 FT AND 3-5 MILE VISIBILITIES IN MIST
NOW SHOWING UP IN THE OBSERVATIONS... AS WELL AS SOME RECENT
REPORTS. WOULD NOT EXPECT TOO MUCH IMPACT HOWEVER SINCE IT WILL
BE FALLING ON TOP OF A FRESH COATING OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 328 AM EST MON FEB 15 2016
FORECAST CONCERNS DEAL WITH THE ONGOING LIGHT SNOW TODAY AND
CHANCES FOR LIGHT SHOW TUESDAY NIGHT.
SNOWFALL HAS BEEN PRETTY UNDERWHELMING SO FAR...BUT IN LINE WITH
EXPECTATIONS. RADAR SHOWS A CHAOTIC ECHO PATTERN BUT HAS BEEN
FILLING IN DURING THE PAST HOUR OR SO. SHORT RANGE MODELS INDICATE
THIS SNOW CONTINUE THIS MORNING AND DIMINISH THIS AFTERNOON.
ALTHOUGH THE SFC LOW IS MOVING AWAY...THE UPPER TROUGH WILL BE
SWINGING THROUGH THIS AFTERNOON AND TONIGHT. THE SNOW SHOULD FINALLY
END AROUND MIDNIGHT TONIGHT WHEN THE UPPER TROUGH AXIS PIVOTS
THROUGH THE CWA.
WEAK LOW PRESSURE WILL MOVE ACROSS THE UPPER MISSISSIPPI VALLEY LATE
TUESDAY AND TUESDAY NIGHT WITH SOME SUPPORT ALOFT. THIS SYSTEM WON/T
AMOUNT TO MUCH EITHER BUT SOME LIGHT SNOW IS POSSIBLE MAINLY TUESDAY
AFTERNOON INTO TUESDAY NIGHT. THE UPPER TROUGH CLEARS LOWER MICHIGAN
WEDNESDAY AND WE/LL SEE IMPROVING CONDITIONS THEN.
HIGH TEMPS WILL REMAIN BELOW AVERAGE THROUGH WEDNESDAY. UPPER 20S
ARE EXPECTED TODAY...MID 30S TUESDAY AND AROUND 30 WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 AM EST MON FEB 15 2016
TURNING WARMER IS THE MAIN MESSAGE FOR THE LONG TERM PERIOD AS THE
UPPER FLOW PATTERN GOES ZONAL AND A PACIFIC STORM TRACKS ACROSS THE
NORTHERN UNITED STATES.
WEDNESDAY NIGHT LOOKS TO BE A COLD ONE WITH A SFC HIGH DIRECTLY
OVERHEAD AND CLEAR SKIES. LOWS 5 TO 15 ABOVE ALTHOUGH SOME ISOLATED
SUB ZERO READINGS ARE POSSIBLE.
INCREASING CLOUDS EXPECTED ON THURSDAY AS THE PACIFIC SYSTEM MOVES
INTO THE NRN PLAINS AND WARM ADVECTION CLOUDS THICKEN AHEAD OF A
WARM FRONT APPROACHING FROM THE SOUTHWEST. THIS FRONT COULD BRING US
A BRIEF PERIOD OF LIGHT FREEZING RAIN/SLEET/SNOW ON THURSDAY NIGHT
BUT ANY PRECIPITATION SHOULD CHANGE QUICKLY TO RAIN EARLY FRIDAY
MORNING AS A 50-60 KT LOW LEVEL JET USHERS IN RAPID WARMING FROM THE
SOUTHWEST.
GUIDANCE TEMPS CONTINUE TO TREND UP FOR FRIDAY WHEN WE WILL BE IN
THE WARM SECTOR OF THE SFC CYCLONE TRACKING ACROSS NORTHERN
MICHIGAN. HIGHS COULD EXCEED 50 DEGREES NEAR AND SOUTH OF I-96
ALTHOUGH IT WILL BE RATHER BREEZY. COOLING OFF A TAD NEXT WEEKEND
BEHIND THE DEPARTING LOW... BUT NO ARCTIC AIR BEHIND IT AND HIGHS
SHOULD BE AT LEAST 5-10 DEGREES ABOVE NORMAL SAT AND SUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1243 PM EST MON FEB 15 2016
A MIX OF IFR AND MVFR CONDITIONS WERE PRESENT OVER THE REGION AS
OF 1730Z. MOST OF THE MVFR WAS ACROSS THE I-96 AREA...WITH
WIDESPREAD IFR ACROSS I-94. WITH A DECREASE IN MIXING THROUGH THE
AFTERNOON AND TONIGHT EXPECT CONDITIONS TO CHANGE VERY LITTLE.
FAIRLY HIGH CONFIDENCE THAT THE I-94 TAF SITES WILL REMAIN
IFR...WITH PERHAPS SOME IMPROVE LATE TONIGHT/EARLY TUESDAY
MORNING AS DRIER AIR ARRIVES. THE I-96 TAF SITES ARE MORE
CHALLENGING AS THEY COULD TREND EITHER WAY...HIGHER OR LOWER. FOR
NOW HAVE TRENDED THESE TAFS UP TO MORE MVFR THROUGH THE AFTERNOON.
BUT THERE IS DECENT CHANCES THESE SITES TREND BACK DOWN AFTER
NIGHTFALL. BY EARLY TUESDAY MORNING THESE SITES TOO SHOULD TREND
BACK UP INTO MVFR.
&&
.MARINE...
ISSUED AT 328 AM EST MON FEB 15 2016
OFFSHORE WINDS 10 TO 20 KNOTS WILL RESULT IN 2-4 FOOT WAVES TODAY.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST SUN FEB 14 2016
NO SIGNIFICANT FLOODING IS EXPECTED THIS WEEK. RIVERS ACROSS
SOUTHWEST LOWER MICHIGAN ARE LARGELY STABLE...ALTHOUGH WE WILL NEED
TO CONTINUE TO MONITOR RIVER LEVELS FOR RAPID FLUCTUATIONS DUE TO
ICE JAMMING. ICE FORMATION AND JAMMING IS STILL A CONCERN GIVEN THE
COLD TEMPERATURES. LOWS WILL BE IN THE TEENS TONIGHT...BUT HIGHS ON
MONDAY WILL BE IN THE LOW TO MID 30S...WHICH SHOULD HALT ICE
FORMATION. WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO
THURSDAY...TEMPS WILL BE WARMER THIS WEEK...TOO WARM FOR ICE TO
THICKEN. RIVERS SHOULD GENERALLY BE ABLE TO FLOW FREELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...EBW
MARINE...04
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1157 AM EST MON FEB 15 2016
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EST MON FEB 15 2016
SEVERAL WEAK LOW PRESSURE SYSTEMS WILL TAKE AIM AT THE GREAT
LAKES...BUT MOSTLY MISS. THE ONGOING LIGHT SNOW OVER LOWER
MICHIGAN WILL DIMINISH TODAY. ANOTHER LOW WILL PASS MOSTLY SOUTH
OF LOWER MICHIGAN TUESDAY. MUCH WARMER AIR IS A STRONG POSSIBILITY
FRIDAY AHEAD OF A LOW MOVING ACROSS THE UP. WE MAY END UP SEEING
RAIN WITH THAT SYSTEM.
&&
.UPDATE...
ISSUED AT 1157 AM EST MON FEB 15 2016
SYSTEM SNOW IS STARTING TO PIVOT OUT OF THE FORECAST AREA AS WE
APPROACH NOON...BUT THERE IS A FINAL BURST MOVING THROUGH CENTRAL
LOWER MI. THE SNOW IS ASSOCIATED WITH A MID LEVEL SHORTWAVE TROUGH
THAT WILL MOVE EAST OF THE AREA THROUGH THE COURSE OF THE
AFTERNOON AND EARLY EVENING HOURS. ANY ADDITIONAL ACCUMULATION
TODAY WILL BE LESS THAN AN INCH.
AS THE MID LEVEL MOISTURE PULLS AWAY AND THERE IS A BIT OF LIFT
LEFT IN THE PROFILE WE MAY CONTINUE TO SEE PATCHY FREEZING
DRIZZLE. CURRENT THINKING IS THAT THIS THREAT IS PRETTY MINIMAL
AND ITS OCCURRENCE SHOULD BE WAINING.
FINAL ITEM OF NOTE IS A BAND OF LAKE EFFECT SNOW OUT OVER LAKE
MICHIGAN. IT IS NOT WELL SEEN AND WE ARE LIKELY OVERSHOOTING IT
FROM THE KGRR RADAR. MULTIPLE RUNS OF THE HRRR HAVE SHOWN THIS
BAND COMING ASHORE BETWEEN 18Z-21Z ACROSS WEST CENTRAL LOWER MI.
THE FLOW BEHIND THE SHORTWAVE WILL SHIFT TO THE SOUTHWEST WHICH
WILL BRING THE BAND ON SHORE. THERE WILL BE A LOCAL BURST TO THE
SNOW AND VISIBILITY WILL BE AFFECTED. COULD SEE A LOCAL INCH OR SO
FROM THIS BAND BEFORE IT MOVES INLAND AND DISSIPATES AFTER
20Z-21Z.
PLENTY OF CLOUDS HANG ON TODAY WITH TEMPERATURES RELEGATED TO THE
20S FOR HIGHS.
UPDATE ISSUED AT 759 AM EST MON FEB 15 2016
HAVE ISSUED AN UPDATE TO INCLUDE A CHANCE OF FREEZING DRIZZLE
MAINLY ALONG AND SOUTH I-96. THIS IS BASED ON THE RECENT ARRIVAL
OF LOWER CEILINGS OF 500-900 FT AND 3-5 MILE VISIBILITIES IN MIST
NOW SHOWING UP IN THE OBSERVATIONS... AS WELL AS SOME RECENT
REPORTS. WOULD NOT EXPECT TOO MUCH IMPACT HOWEVER SINCE IT WILL
BE FALLING ON TOP OF A FRESH COATING OF LIGHT SNOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 328 AM EST MON FEB 15 2016
FORECAST CONCERNS DEAL WITH THE ONGOING LIGHT SNOW TODAY AND
CHANCES FOR LIGHT SHOW TUESDAY NIGHT.
SNOWFALL HAS BEEN PRETTY UNDERWHELMING SO FAR...BUT IN LINE WITH
EXPECTATIONS. RADAR SHOWS A CHAOTIC ECHO PATTERN BUT HAS BEEN
FILLING IN DURING THE PAST HOUR OR SO. SHORT RANGE MODELS INDICATE
THIS SNOW CONTINUE THIS MORNING AND DIMINISH THIS AFTERNOON.
ALTHOUGH THE SFC LOW IS MOVING AWAY...THE UPPER TROUGH WILL BE
SWINGING THROUGH THIS AFTERNOON AND TONIGHT. THE SNOW SHOULD FINALLY
END AROUND MIDNIGHT TONIGHT WHEN THE UPPER TROUGH AXIS PIVOTS
THROUGH THE CWA.
WEAK LOW PRESSURE WILL MOVE ACROSS THE UPPER MISSISSIPPI VALLEY LATE
TUESDAY AND TUESDAY NIGHT WITH SOME SUPPORT ALOFT. THIS SYSTEM WON/T
AMOUNT TO MUCH EITHER BUT SOME LIGHT SNOW IS POSSIBLE MAINLY TUESDAY
AFTERNOON INTO TUESDAY NIGHT. THE UPPER TROUGH CLEARS LOWER MICHIGAN
WEDNESDAY AND WE/LL SEE IMPROVING CONDITIONS THEN.
HIGH TEMPS WILL REMAIN BELOW AVERAGE THROUGH WEDNESDAY. UPPER 20S
ARE EXPECTED TODAY...MID 30S TUESDAY AND AROUND 30 WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 AM EST MON FEB 15 2016
TURNING WARMER IS THE MAIN MESSAGE FOR THE LONG TERM PERIOD AS THE
UPPER FLOW PATTERN GOES ZONAL AND A PACIFIC STORM TRACKS ACROSS THE
NORTHERN UNITED STATES.
WEDNESDAY NIGHT LOOKS TO BE A COLD ONE WITH A SFC HIGH DIRECTLY
OVERHEAD AND CLEAR SKIES. LOWS 5 TO 15 ABOVE ALTHOUGH SOME ISOLATED
SUB ZERO READINGS ARE POSSIBLE.
INCREASING CLOUDS EXPECTED ON THURSDAY AS THE PACIFIC SYSTEM MOVES
INTO THE NRN PLAINS AND WARM ADVECTION CLOUDS THICKEN AHEAD OF A
WARM FRONT APPROACHING FROM THE SOUTHWEST. THIS FRONT COULD BRING US
A BRIEF PERIOD OF LIGHT FREEZING RAIN/SLEET/SNOW ON THURSDAY NIGHT
BUT ANY PRECIPITATION SHOULD CHANGE QUICKLY TO RAIN EARLY FRIDAY
MORNING AS A 50-60 KT LOW LEVEL JET USHERS IN RAPID WARMING FROM THE
SOUTHWEST.
GUIDANCE TEMPS CONTINUE TO TREND UP FOR FRIDAY WHEN WE WILL BE IN
THE WARM SECTOR OF THE SFC CYCLONE TRACKING ACROSS NORTHERN
MICHIGAN. HIGHS COULD EXCEED 50 DEGREES NEAR AND SOUTH OF I-96
ALTHOUGH IT WILL BE RATHER BREEZY. COOLING OFF A TAD NEXT WEEKEND
BEHIND THE DEPARTING LOW... BUT NO ARCTIC AIR BEHIND IT AND HIGHS
SHOULD BE AT LEAST 5-10 DEGREES ABOVE NORMAL SAT AND SUN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM EST MON FEB 15 2016
PREDOMINATELY MVFR CONDITIONS EXPECTED TODAY WITH OCCASIONAL
LIGHT SNOW ALTHOUGH SOME SPOTTY IFR POSSIBLE AS BANDS OF HEAVIER
SNOW PIVOT THROUGH THIS MORNING. MVFR CONTINUING TONIGHT WITH A
POSSIBILITY OF IFR BECOMING MORE WIDESPREAD AFTER 06Z AS CIGS
LOWER SOME.
&&
.MARINE...
ISSUED AT 328 AM EST MON FEB 15 2016
OFFSHORE WINDS 10 TO 20 KNOTS WILL RESULT IN 2-4 FOOT WAVES TODAY.
&&
.HYDROLOGY...
ISSUED AT 329 PM EST SUN FEB 14 2016
NO SIGNIFICANT FLOODING IS EXPECTED THIS WEEK. RIVERS ACROSS
SOUTHWEST LOWER MICHIGAN ARE LARGELY STABLE...ALTHOUGH WE WILL NEED
TO CONTINUE TO MONITOR RIVER LEVELS FOR RAPID FLUCTUATIONS DUE TO
ICE JAMMING. ICE FORMATION AND JAMMING IS STILL A CONCERN GIVEN THE
COLD TEMPERATURES. LOWS WILL BE IN THE TEENS TONIGHT...BUT HIGHS ON
MONDAY WILL BE IN THE LOW TO MID 30S...WHICH SHOULD HALT ICE
FORMATION. WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO
THURSDAY...TEMPS WILL BE WARMER THIS WEEK...TOO WARM FOR ICE TO
THICKEN. RIVERS SHOULD GENERALLY BE ABLE TO FLOW FREELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...DUKE
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...04
AREA FORECAST DISCUSSION
NWS BILLINGS MT
325 PM MST MON FEB 15 2016
.SHORT TERM...VALID FOR TUE AND WED...
STRONG NORTHWEST FLOW OVER THE AREA WITH A MODERATELY STRONG
SHORTWAVE WORKING ACROSS THE FORECAST AREA. THIS WAVE WAS
GENERATING NUMEROUS SHOWERS OVER CENTRAL ZONES. STRONG DOWNSLOPE
FLOW WAS LIMITING SHOWER COVERAGE OVER WESTERN ZONES. ASCENT FROM
THE SHORTWAVE WAS KEEPING THE STRONGEST WINDS OF THE DAY ALOFT.
VAD WIND PROFILER WAS SHOWING 45KTS JUST FOUR THOUSAND FEET OFF
THE SURFACE. STRONGEST WIND GUST AT BILLINGS HAS BEEN 53MPH AND
THIS AIDED BY A FEW SHOWERS. STRONGEST SURFACE PRESSURE RISES WERE
NOW MOVING INTO NORTHERN MONTANA AND PROGGED TO SLIDE ACROSS THE
FORECAST AREA DURING THE EARLY EVENING. 700MB WINDS WEAKEN A BIT
WITH THE STRONGEST PRESSURE RISES...BUT ASCENT WILL BE REPLACED BY
SUBSIDENCE. CONFIDENCE NOT TERRIBLY HIGH THAT WARNING LEVEL WINDS
WILL BE MET EARLY THIS EVENING...BUT ENOUGH THERE TO KEEP THE
HIGHLIGHT GOING.
LIVINGSTON HAS REMAINED BELOW ADVISORY CRITERIA THROUGH THE DAY
AND SURFACE WINDS HAVE TURNED TO THE WEST. RAP SOUNDINGS SHOW
WINDS DECREASING ALOFT OVER THE WEST WITH SURFACE PRESSURE
GRADIENT RELAXING. STRONGEST SURFACE PRESSURE RISES WILL SLIDE
EAST OF LIVINGSTON EARLY THIS EVENING. THE LACK OF GAP FLOW WOULD
LEAD TO A LESS THAN IDEAL SITUATION FOR ADVISORY LEVEL WINDS.
GUIDANCE WINDS HAVE THE TREND FOR DECREASING SURFACE WINDS THE
REST OF THE AFTERNOON AND EARLY THIS EVENING. THE SURFACE PRESSURE
GRADIENT RELAXES QUITE A BIT THIS EVENING...BUT RELOADS AGAIN
TUESDAY MORNING. GUIDANCE INDICATED THE POSSIBILITY OF HITTING
CRITERIA TUESDAY MORNING. WILL KEEP THE GRAPHIC OUT AND MENTION OF
IT IN THE HWO FOR THE MORNING HOURS...BUT WILL LET THE EVENING AND
MIDNIGHT CREWS GET A CLOSER LOOK ON POSSIBLY ISSUING ANOTHER
HIGHLIGHT FOR THIS.
SNOW HAS BEEN STEADY IN THE BIGHORNS THIS AFTERNOON. SNOTELS VARY
IN ACCUMULATION...BUT THE CONSENSUS OF 4-6 INCHES SEEMS TO BE ABOUT
THE MEDIUM SNOW RANGE. MODELS...INCLUDING HIGH RESOLUTION...ALL
TAPER THE SNOW OFF THROUGH THE EVENING. WOULD EXPECT ANOTHER 2-4
INCHES THE REST OF THE AFTERNOON AND THIS EVENING. WILL KEEP THE
ADVISORY GOING.
MEAN UPPER RIDGE REMAINS TO THE WEST OF MONTANA FOR TUESDAY.
ATMOSPHERE LOOKS UNSTABLE ONCE AGAIN BUT MID LEVEL WINDS WERE
WEAKER. 700MB WINDS WERE AROUND 45KTS AND NOT LINKED UP TOTALLY
WITH LOWER LEVEL WINDS. DOWNWARD MOTION SHOULD BE WEAKER TOO WITH
MUCH WEAKER SURFACE PRESSURE RISES. WINDS SHOULD MATERIALIZE...BUT
NOT EXPECTING WINDS AT LEVELS OF TODAY OR THIS WEEKEND. WILL OPT
TO NOT ISSUE A HIGHLIGHT...AND DUE TO THE BELIEF THAT THIS WILL
NOT BE A HIGHLIGHT WORTHY EVENT...WILL REMOVE MENTION FROM THE HWO
FOR THE PLAINS. SHOULD BE A WINDY DAY...BUT NOT EXPECTING ANYTHING
MORE THAN THAT.
DID TAKE A FEW DEGREES OFF FORECAST HIGHS FOR TUESDAY. MIX DOWNS
WOULD HAVE HIGHS TOPPING OUT IN THE UPPER 50S. GFS PLACES A SWATH
OF MID LEVEL WARM ADVECTION PRECIPITATION OVER CENTRAL ZONES LATE
TONIGHT AND EARLY TUESDAY. MODEL CONSENSUS LEADS TO MORE
CONFIDENCE OF THIS POSSIBILITY...SO RAISED POPS TO SCATTERED.
TEMPERATURES REMAIN MILD IN DOWNSLOPE FLOW...SO A MIX OF RAIN AND
SNOW LOOKS TO BE THE EVENT...WITH LIMITED IMPACT. WEDNESDAY LOOKS
DRIER AS A FLAT RIDGE SLIDES INTO THE FORECAST AREA. TWH
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
A PACIFIC TROUGH IS PROGGED TO APPROACH THE REGION ON THURSDAY.
THIS FEATURE SHOULD SPREAD SHOWERS AHEAD OF IT THU AFTERNOON-
EVENING. IT SHOULD ALSO DROP SURFACE PRESSURES EAST OF THE
MOUNTAINS...SETTING UP A DECENT PRESSURE GRADIENT FOR THU
AFTERNOON INTO FRI. GFS SHOWING 3-HOUR SFC PRESSURE RISES OF
AROUND 6 MB AROUND 00Z FRI. THUS EXPECT ANOTHER WINDY PERIOD FOR
THU AFTERNOON-FRI...WITH POSSIBLY WINDIEST PERIOD LATE THU
AFTERNOON- EVENING.
DRY WX EXPECTED FOR MOST OF THE AREA FRI-SUN AS UPPER-LEVEL
RIDGING DOMINATES REGIONAL WEATHER. A WEAK SHORTWAVE TRACKING NEAR
OUR NORTHWESTERN CWA COULD BRING A FEW SHOWERS TO OUR WESTERN CWA
ON SAT.
LASTLY THE GLOBAL GUIDANCE SUGGEST A QUICK CLIPPER PASSING THROUGH
AT THE BEGINNING OF NEXT WEEK BUT TIMING AND TRACK DIFFERENCES
MEANT LOW CONFIDENCES IN THE POP AND TEMP FIELDS. RMS/TWH
&&
.AVIATION...
SURFACE WINDS AT KBIL AND KSHR WILL HAVE GUSTS APPROACHING 50KTS
THE REST OF THE AFTERNOON AND EARLY THIS EVENING. WINDS AT KLVM
HAVE DECREASED SOME AND SHOULD REMAIN BELOW 40KTS THIS EVENING BUT
ARE EXPECTED TO INCREASE AGAIN TO NEAR 50KTS TUESDAY MORNING.
SCATTERED SHOWERS WILL PRODUCE LOCAL MVFR CONDITIONS FROM KBIL TO
KMLS TO KSHR THROUGH THE LATE EVENING HOURS. MOUNTAINS WILL BE
OBSCURED...ESPECIALLY THIS EVENING. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 033/059 036/059 043/058 038/055 035/052 029/051 030/048
42/W 11/B 13/W 21/N 11/B 11/B 12/W
LVM 038/056 036/058 041/052 036/049 032/046 025/046 026/044
51/N 11/N 14/W 31/N 22/W 21/B 12/W
HDN 031/060 033/060 036/060 037/055 033/053 028/050 029/047
43/W 11/B 13/W 31/N 11/B 11/B 12/W
MLS 028/053 029/056 034/059 040/056 033/052 029/048 030/049
25/W 10/B 13/W 41/N 11/N 11/B 12/W
4BQ 029/055 030/058 035/062 038/055 032/052 028/048 027/048
34/W 10/B 03/W 41/N 11/B 11/B 12/W
BHK 025/044 026/051 032/060 038/053 030/049 027/044 026/045
24/W 10/B 11/B 51/N 11/N 11/B 12/J
SHR 029/056 029/057 034/059 032/051 029/051 025/047 022/046
62/J 10/B 03/W 31/N 12/W 11/B 12/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...HIGH WIND WARNING IN EFFECT UNTIL 8 PM MST THIS EVENING FOR
ZONES 28>31-34-35-38-41-42-57-58-63.
WY...HIGH WIND WARNING IN EFFECT UNTIL 8 PM MST THIS EVENING FOR
ZONE 99.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM MST THIS
EVENING FOR ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
341 PM CST MON FEB 15 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM CST MON FEB 15 2016
THE MAIN FORECAST CHALLENGES THROUGH TUESDAY AFTERNOON ARE
PRECIPITATION AND TEMPERATURES. A POTENT SHORTWAVE ALONG WITH A
SURFACE/LOW LEVEL TROUGH WILL CROSS THE FORECAST AREA THIS
EVENING AND TONIGHT. THE CIRRUS DECK...WHICH EXTENDS INTO THE
DAKOTAS AND MONTANA BASED ON IR/WV...HAS BEEN RATHER DENSE TODAY
WHICH HAS SLOWED THE RISE IN TEMPS. DESPITE MID/UPPER LEVEL
MOISTURE AND WEAK RADAR ECHOES OVER THE PANHANDLE AND NORTHWEST
NEBRASKA TODAY...ABUNDANT DRY LEVEL AIR HAS JUST LED TO VIRGA.
THIS EVENING AND TONIGHT...EXPECT SATURATION TO SLOWLY WORK DOWN
TO ABOUT 800-850HPA AS INDICATED IN NAM...GFS...AND RAP FORECAST
SOUNDINGS. THE RAP ALSO SHOWS SUFFICIENT LOW LEVEL LIFT TO
SUPPORT SHOWER ACTIVITY...ESPECIALLY ACROSS NORTHERN NEBRASKA.
BASED ON SOME VIRGA IN SOUTHWEST NEBRASKA AND LAPSE RATES OF
7-8C/KM DIRECTLY ABOVE THE SFC INVERSION FROM RAP
SOUNDINGS...EXPANDED SCHC MENTION TO COVER THE REST OF THE CWA. A
120+KT 250HPA JET ENTERS THE AREA LATE TONIGHT...ADDING TO THE
UPPER LEVEL DYNAMICS AND DIVERGENCE. WITH SFC TEMPS IN THE UPPER
30S/LOWER 40S THROUGH 06Z AND SFC WET BULB AOA 0C...EXPECT
PREDOMINANT PTYPE TO BE RAIN. DRY AIR ENTRAINS INTO THE SYSTEM
FROM THE WEST BY 06Z...LIMITING PRECIP CHANCES TO NORTH CENTRAL
NEB. CUT MENTION TO SPRINKLES NEAR KONL WITH BULK OF MOISTURE
STAYING BELOW 800HPA AND THE LOSS OF APPRECIABLE LIFT. A FEW
SNOWFLAKES MAY MIX IN AT THE END...BUT MOISTURE REALLY SHUTS OFF
WHEN THE TEMPERATURE PROFILE WOULD SUPPORT FZRA OR RASN. MADE
LITTLE ADJUSTMENT TO MIN TEMPS AS THEY GENERALLY LIE NEAR MOS
GUIDANCE...PRIMARILY MAV AND ECM. TEMPS REMAIN RATHER MILD DUE TO
CONTINUED CLOUD COVER AND GUSTY WINDS. WENT SLIGHTLY ABOVE
GUIDANCE FOR WIND SPEED DURING THE FROPA AS NORTHWEST 850HPA
WINDS OF 35-45KTS ARE SHOWN BY THE NAM AND RAP. CONFIDENCE IN MIN
TEMPS A LITTLE LOWER SOUTH OF I-80 WHERE SOME PARTIAL CLEARING
AND LIGHTENING OF WINDS TOWARD DAWN IS POSSIBLE...LEADING TO
COOLER TEMPS.
TUESDAY...TRENDED MAX TEMPS DOWN A DEGREE OR SO FOR MOST
LOCATIONS BUT STILL REMAIN MILD WITH 50S SW AND 40S NC. MODELS
SHOW CAA FOR MOST OF THE DAY AND 850HPA TEMPS BELOW 0C UNTIL 00Z
WED. ANOTHER MOSTLY CLOUDY DAY IS LIKELY AS THE MOISTURE PLUME AS
SHOWN BY WV IMAGERY EXTENDS WELL TO THE NORTHWEST. ALSO...ANOTHER
BOUNDARY EXITS THE PANHANDLE IN THE AFTERNOON...HELPING ENHANCE
LOWER LEVEL LIFT. THE NAM SHOWS BROAD ISENTROPIC LIFT AT 290K
ACROSS THE SANDHILLS AFTER 18Z AND 500HPA TEMPS NEAR -20C. FAR
WEST/PANHANDLE...WHERE DOWNGLIDE WILL TAKE EFFECT EARLIER AFTER
THE BOUNDARY PASSAGE AND 850HPA WAA...MAX TEMPS MAY BE ON THE
COOL SIDE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM CST MON FEB 15 2016
LONG TERM DOMINATED BY ABOVE NORMAL TEMPERATURES AND LITTLE IF
ANY CHANCE FOR PRECIPITATION. DURING THE MIDDLE PART OF THE WORK
WEEK THE WESTERN RIDGE WILL MIGRATE EAST AND AMPLIFY OVER THE
PLAINS. A WARM FRONT WILL LIFT ACROSS THE AREA WITH A THERMAL
RIDGE PEAKING ON THURSDAY BEFORE A COLD FRONT MOVES THROUGH
THURSDAY NIGHT. WITH THE FRONTAL PASSAGE A SLIGHT CHANCE FOR A
RAIN SHOWER IS POSSIBLE NEAR THE NEB/S DAKOTA BORDER...HOWEVER
WOULD NOT BE SURPRISED IF THE DRY LOWER LEVELS IS TOO MUCH TO
OVERCOME AND NOTHING REACHING THE GROUND. BEHIND THE FRONT WEAK
RIDGING REBUILDS QUICKLY ACROSS THE ROCKIES...KEEPING TEMPS ABOVE
SEASONAL NORMS INTO THE WEEKEND.
WARMEST DAY OF THE PERIOD IS EXPECTED TO BE THURSDAY AS MODELS
SURGE 850 MB TEMPS WELL INTO THE TEENS TO AROUND 20 C. MOS
GUIDANCE IS ALSO UNSEASONABLY HIGH WITH UPPER 60S TO LOWER 70S.
SHOULD HAVE MOST OF THE SNOW MELTED BY THEN AND MODELS INDICATING
BREEZY CONDITIONS SO MIXING SHOULD BE REALIZED AND FORECAST
FOLLOWS CLOSE TO GUIDANCE. RECORDS THIS TIME OF YEAR ARE LOWER
70S...SO WILL HAVE TO MONITOR AS A RECORD HIGH MAY BE REACHED.
ALSO GOING TO HAVE TO WATCH FIRE CONDITIONS...AS OFTEN WITH
RECORD WARMTH IS A HIGH FIRE DANGER. MIN RH VALUES LIKELY NEAR 20
PERCENT IN A FEW LOCATIONS...AND COULD BE LOWER.
WHILE THE PACIFIC COLD FRONT THURSDAY NIGHT WILL KNOCK DOWN TEMPS
FOR THE WEEKEND...GUIDANCE STILL HAS TEMPS REBOUNDING TO AROUND
60...WHICH WILL BE ABOVE NORMAL. ANOTHER WEAK COLD FRONT WILL
ARRIVE OVER THE WEEKEND WITH ANOTHER COOL DOWN EXPECTED. LIMITED
MOISTURE WITH THIS FRONT AND FORECAST REMAINS DRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1122 AM CST MON FEB 15 2016
CIRRUS WILL CONTINUE TO OVERSPREAD WESTERN NEBRASKA THIS
AFTERNOON AND CIGS WILL GRADUALLY FALL AS MOISTURE FILLS IN. THE
BEST CHANCE OF PRECIPITATION LIES ACROSS NORTHERN NEBRASKA THIS
EVENING AND TONIGHT...PRIMARILY FROM KAIA TO KBBW AND NORTH...BUT
A FEW SHOWERS CANNOT BE RULED OUT SOUTH. AT THIS TIME...ALL
PRECIP SHOULD FALL AS RAIN AND SURFACE TEMPS REMAIN ABOVE
FREEZING. HOWEVER...SOME CIGS MAY APPROACH MVFR AT NORTHERN
TERMINALS. A LARGE WIND SHIFT WILL OCCUR LATE THIS EVENING WITH A
COLD FRONT PASSAGE...SWITCHING TO NORTHWEST AND GUSTING ABOVE 25
KTS. WIND GUSTS SHOULD DIMINISH AND CIGS SHOULD RISE TO VFR BY
12Z TUESDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNIVELY
LONG TERM...MASEK
AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
306 PM CST MON FEB 15 2016
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CST MON FEB 15 2016
NEXT CLIPPER SYSTEM WAS LOCATED OVER WESTERN NORTH DAKOTA AT 20Z
WITH MILD TEMPERATURES FOUND ACROSS EASTERN NEBRASKA AND SOUTHWEST
IOWA.
MAIN CONCERN TONIGHT WILL BE TIMING OF THE FEATURE AS IT MOVES
SOUTHEAST ALONG WITH EXTENT AND TYPE OF PRECIP. 19Z RUC BRINGS
THE SURFACE LOW INTO EASTERN NEBRASKA PRIOR TO 06Z AND INTO
CENTRAL MISSOURI BY 12Z. WITH SURFACE TEMPERATURES EXPECTED TO
REMAIN ABOVE FREEZING IN MOST AREAS THROUGH 06Z PRECIP SHOULD BE
LIQUID DURING THAT TIME THEN CHANGE OVER TO SNOW OR A RAIN SNOW
MIX NORTH TO SOUTH AS TEMPERATURES COOL ALOFT AND SYSTEM TRACKS
TO THE SOUTHEAST. SOME POTENTIAL FOR ISOLATED THUNDER IN THE FAR
SOUTHEAST LATE TONIGHT WHERE SOME MID LEVEL INSTABILITY INDICATED.
LATEST DAY1 OUTLOOK FROM SPC SHOWS AN AXIS FOR GENERAL THUNDER
INTO CENTRAL MISSOURI. COOLER AIR FOLLOWS BEHIND THE SYSTEM ON
TUESDAY WITH WEAK HIGH PRESSURE OVER THE REGION.
WARM ADVECTION BEGINS TUESDAY NIGHT INTO WEDNESDAY AS WESTERN
RIDGE STARTS TO MOVE EAST WITH SPRING LIKE TEMPERATURES FOR THE
AREA ON THURSDAY. SOUTHEAST PARTS OF THE AREA WHICH HAVE BEEN SNOW
FREE FOR MOST OF THE MONTH MAY APPROACH 70.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CST MON FEB 15 2016
MILD PATTERN CONTINUES THROUGH THE PERIOD AS FLOW REMAINS NEARLY
ZONAL. SOME PRECIP MAY CLIP NORTHERN PARTS OF THE AREA THURSDAY
NIGHT AS FAST MOVING SHORT WAVE TRACKS ACROSS THE NORTHERN PLAINS
BUT OTHERWISE LOOKS DRY AFTER THAT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1146 AM CST MON FEB 15 2016
LOW PRESSURE SYSTEM WILL SWING THROUGH EASTERN NEBRASKA THIS
EVENING. AHEAD OF IT...SOUTH TO SOUTHWEST WINDS AND INCREASING
MID/HIGH CLOUDS ARE FORECAST. AS LOW APPROACHES...AREAS OF RAIN
AND MVFR CIGS WILL DEVELOP...FIRST AT KOFK BY 04Z THEN AT KOMA AND
KLNK BY 06Z. A MIX OF RAIN AND SNOW IS POSSIBLE AFTER 06Z AT ALL
SITES WITH CIGS DROPPING TO NEAR FL010. EXPECT ABOUT 4 HOURS OF
POTENTIAL PRECIPITATION BEFORE MOVING OFF TO THE SOUTHEAST.
STRONG NORTHWEST WINDS WILL FOLLOW...REACHING THE 20 TO 30KT RANGE
AFTER 10Z AND CONTINUING THROUGH END OF TAF PERIOD. MVFR CIGS WILL
ALSO SPILL IN BEHIND THIS SYSTEM...AND THOSE COULD GO IFR FOR A
TIME BETWEEN 12Z AND 18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1214 PM CST MON FEB 15 2016
.SYNOPSIS...
ISSUED AT 311 AM CST MON FEB 15 2016
AT 09Z...A WEAK SURFACE TROUGH EXTENDED SOUTH ACROSS THE NORTHERN
AND CENTRAL PLAINS. MAINLY CLEAR SKIES IN THE WAKE OF A DEPARTING
DISTURBANCE WITH HIGH CLOUDINESS BEGINNING TO PUSH INTO WESTERN
SOUTH DAKOTA. SOME WINDS IN WESTERN NEBRASKA HAVE DECOUPLED WITH
VALENTINE AT 27 AND NORTH PLATTE 23. OTHER REPORTING STATIONS IN THE
LOWER TO MID 30S.
&&
.UPDATE...
ISSUED AT 1214 PM CST MON FEB 15 2016
INTRODUCED SPRINKLES IN SOUTHWEST NEBRASKA THIS EVENING. HRRR IS
CONSISTENT WITH LIGHT SHOWERS MOVING THROUGH AND RAP FORECAST
SOUNDINGS INDICATE LOW LEVEL LIFT AND HIGH RH AS LOW AS 5KFT AGL
AT KLBF. TWEAKED MAX TEMPS UP NEAR KONL WHERE MORE CLEARING WAS
EXPERIENCED THIS MORNING AND DOWN A DEGREE OR TWO ELSEWHERE WHERE
THICK CIRRUS IS SLOWING TEMP RISES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST MON FEB 15 2016
A DISTURBANCE CURRENTLY MOVING INTO NORTHWEST MONTANA WILL MOVE
SOUTHEAST ACROSS WESTERN SD THIS AFTERNOON. THIS WILL OVERSPREAD
MID AND HIGH CLOUDINESS ACROSS THE FA THIS AFTERNOON. H85 TEMPS WILL
BE MILD RANGING FROM 3C IN THE FAR NORTHEAST TO 10C IN THE FAR
SOUTHWEST...MIXING DOWN THESE TEMPERATURES BRINGS MOST HIGHS UP INTO
THE 52-55 DEGREES RANGE...EXCEPT UPPER 40S FAR EASTERN ZONES.
AFTERNOON CLOUDINESS WILL LIMIT THE WARMUP SO WENT WITH THE WARMER
MAV GUIDANCE...AND LOWERED THE WARMEST AREAS A FEW DEGREES. WINDS
WILL BE WEST AND WILL INCREASE TO 10 TO 20 MPH THIS AFTERNOON WEST
OF HWY 183.
THE DISTURBANCE WILL MOVE INTO CENTRAL AND EASTERN SD...NORTHERN AND
EASTERN NEBRASKA THIS EVENING. LATEST FCST POPS ARE NEAR PREVIOUS
FCST WITH SLIGHT CHC POPS NEAR AND NORTH OF HWY 2 THIS EVENING.
RAISED TO A HIGHER 30-40 POPS NORTHEAST OF VALENTINE THROUGH
BARTLETT. THIS IS BY NO MEANS AN ORGANIZED SYSTEM...WITH VARYING
MODEL SOLUTIONS OF LOCATION OF HIGHER POPS. A LOOK AT GFS BUFKIT
SOUNDING AT ONEILL INDICATES A FAIRLY DRY LAYER BELOW 800MB WITH
TEMPERATURES FAVORING RAIN AS PRECIP TYPE. THIS WILL ALSO BRING A
PACIFIC COLD FRONT ACROSS TONIGHT WITH NORTHWEST WINDS INCREASING TO
15 TO 25 MPH. WITH WINDS DECOUPLING ACROSS THE WEST LATER
TONIGHT...LOWS A BIT COLDER NEAR 30...WHILE WINDS STAYING UP ACROSS
THE EAST WILL KEEP LOWS NEAR 35.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM CST MON FEB 15 2016
RIDGING ALOFT WILL BE IN THE PROCESS OF BUILDING NORTHWARD ACROSS
THE WESTERN THIRD OF THE COUNTRY TUESDAY...SHIFTING EASTWARD
OVER THE CENTRAL PORTIONS OF THE COUNTRY WEDNESDAY INTO THURSDAY.
THIS WILL ALL TAKE PLACE AHEAD OF A LONG WAVE TROUGH AND PACIFIC
STORM SYSTEM THAT WILL MOVE ONTO THE WEST COAST WEDNESDAY NIGHT.
A THERMAL RIDGE WILL BECOME ESTABLISHED ACROSS THE CENTRAL PLAINS
BENEATH THE UPPER RIDGING ALOFT...WITH VERY WARM AIR FROM THE
SURFACE UP THROUGH THE MID LEVELS OF THE ATMOSPHERE. THIS WILL
PEAK THURSDAY WHICH WILL BE THE WARMEST DAY OF THE WEEK. MODELS
AGREE THAT H850MB TEMPERATURES WILL EASILY SUPPORT SURFACE
TEMPERATURES REACHING 70 DEGREES ACROSS FAR SOUTHWEST
NEBRASKA...WITH MID TO UPPER 60S ELSEWHERE. NOT EXPECTING MUCH
CIRRUS CLOUD COVER TO HINDER THE WARM UP EITHER...SO CONFIDENT IN
THE WARM TEMPERATURE FORECAST.
THE AFOREMENTIONED LONG WAVE TROUGH WILL DAMPEN AND QUICKLY CROSS
THE CENTRAL AND NORTHERN PLAINS FRIDAY. THIS WILL SEND A PACIFIC
COLD FRONT ACROSS THE REGION...WITH TEMPERATURES A FEW DEGREES
COOLER BUT STILL WELL ABOVE FRIDAY INTO THE WEEKEND. LITTLE IF ANY
PRECIPITATION IS EXPECTED...WHICH IS NORMAL IN THIS TYPE OF UPPER
LEVEL PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1122 AM CST MON FEB 15 2016
CIRRUS WILL CONTINUE TO OVERSPREAD WESTERN NEBRASKA THIS
AFTERNOON AND CIGS WILL GRADUALLY FALL AS MOISTURE FILLS IN. THE
BEST CHANCE OF PRECIPITATION LIES ACROSS NORTHERN NEBRASKA THIS
EVENING AND TONIGHT...PRIMARILY FROM KAIA TO KBBW AND NORTH...BUT
A FEW SHOWERS CANNOT BE RULED OUT SOUTH. AT THIS TIME...ALL PRECIP
SHOULD FALL AS RAIN AND SURFACE TEMPS REMAIN ABOVE FREEZING.
HOWEVER...SOME CIGS MAY APPROACH MVFR AT NORTHERN TERMINALS. A
LARGE WIND SHIFT WILL OCCUR LATE THIS EVENING WITH A COLD
FRONT PASSAGE...SWITCHING TO NORTHWEST AND GUSTING ABOVE 25 KTS.
WIND GUSTS SHOULD DIMINISH AND CIGS SHOULD RISE TO VFR BY 12Z
TUESDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SNIVELY
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...TAYLOR
AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
559 PM EST MON FEB 15 2016
.SYNOPSIS...A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN
SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS
THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 PM MONDAY...
...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY
EXTENDED THROUGH 700 AM TUESDAY MORNING...
...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES
EXTENDED THROUGH MIDNIGHT TONIGHT...
...WINTER WEATHER ADVISORY FOR THE REST OF THE PIEDMONT EXTENDED
UNTIL 7 PM THIS EVENING...
RESIDUAL WEDGE OF ARCTIC HIGH PRESSURE WILL CONTINUE TO SUPPORT
LIGHT FREEZING RAIN/DRIZZLE ACROSS THE NORTHERN/NORTHWESTERN
PIEDMONT THROUGH THE EVENING...WITH A CHANGE OVER TO RAIN FROM SE TO
NW THROUGH THE EVENING HOURS AS A COASTAL WARM FRONT RETREATS INLAND
IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM APPROACHING FROM THE
SOUTHWEST.
KGSO RAOB SPECIAL 18Z RELEASE REVEALS THAT THE EXPECTED
STRONG/SIGNIFICANT WARMING ALOFT HAS INDEED MATERIALIZE...WARMER AND
QUICKER THAN FORECAST....WITH 6 C WARM NOSE NOTED ~875MB. A WARM
NOSE OF THIS MAGNITUDE WILL SUPPORT PRECIPITATION PRIMARILY IN THE
FORM OF FREEZING RAIN/DRIZZLE ACROSS THE FORECAST AREA UNTIL THE
CHANGE OVER TO RAIN AS THE COASTAL FRONT/PRE-FRONTAL WARM SECTOR
RETREATS SE TO NW INTO THE AREA. THE HRRR WHICH HAS DONE AN
EXCELLENT JOB WITH THE NEAR FREEZING SFC WET-BULB TRENDS ACROSS THE
FORECAST AREA(DELINEATES THE CHANGE-OVER FROM FREEZING RAIN TO
RAIN)BRINGS THE NEAR FREEZING SFC WET-BULB THROUGH THE TRIANGLE
BETWEEN 21 TO 00Z...AND THROUGH THE TRIAD BETWEEN 03 TO 06Z.
INTERMITTENT LIGHT FREEZING RAIN AND DRIZZLE WILL SUPPORT A TENTH TO
TWO-TENTHS OF AN INCH OF ICE ACROSS THE PIEDMONT...WITH THE HIGHEST
AMOUNTS IN THE HEART OF THE DAMMING REGION(WARNING AREA). THE
FREEZING RAIN THREAT ACROSS THE TRIAD AND PERSON COUNTY LOOKS TO BE
OVER SHORTLY AFTER MIDNIGHT...WITH TEMPERATURES RISING ABOVE
FREEZING AS THE PRE-FRONTAL WARM SECTOR OVERTAKES THE AREA. THE
WINTER STORM WARNING LIKELY TO BE CANCELLED EARLY(EXPIRES AT 7AM).
ATTENTION WILL QUICKLY TURN FROM FREEZING RAIN ACROSS THE NORTHWEST
PIEDMONT TO THE POTENTIAL FOR STRONG TO SEVERE STORMS ACROSS EASTERN
NC BY AROUND DAYBREAK AS NEGATIVE TILTED MID/UPPER WAVE AND
ATTENDANT DEEPENING SFC LOW APPROACH THE AREA FROM THE
WEST/SOUTHWEST. STRONG/DEEP ASCENT WITH IN THE RIGHT REAR QUADRANT
OF THE UPPER JET STREAK AND ALONG THE NOSE OF A POWERFUL 60-70KT LLJ
WILL SUPPORT A CONVECTIVE LINE OF HEAVY RAIN SHOWERS AND POSSIBLY A
FEW THUNDERSTORMS. AS THE LINE ENCOUNTERS THE BETTER INSTABILITY IN
THE EAST(MUCAPE 200-500 J/KG...STRONG TO SEVERE WIND GUST WILL BE
POSSIBLE...ALONG WITH AN ISOLATED TORNADO POSSIBLE.
WITH THE PRE-FRONTAL WARM SECTOR SPREADING NORTH INTO THE AREA...
TEMPERATURES WILL BE ON THE RISE OVERNIGHT...WARMING IN THE 40S
ACROSS THE WEST TO LOWER/MID 50S SE.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 255 PM MONDAY...
PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL
BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE
OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO
THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON.
INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH
ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE
FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A
MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING
ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60-
70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH
18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE
STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN
OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS
SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION
TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS
TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP
OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE
STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE
POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA.
OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 310 PM MONDAY...
UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY-
THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF
UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE
PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE
MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE
PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH
AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF
DEGREES BELOW FREEZING.
THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE
WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL
INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL
BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM
WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT
ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE
FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR.
MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL-
NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING
MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS
MONDAY BUT KEEP POPS AOB 20%.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
AS OF 555 PM MONDAY...
...DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT...
(V)LIFR CONDITIONS; PERIODS OF PRECIPITATION --ALL OCCASIONALLY
MODERATE TO HEAVY AND SOME WINTRY FOR THE NEXT SEVERAL HOURS-- AND
DEVELOPING LOW LEVEL WIND SHEAR CONDITIONS...WILL AFFECT CENTRAL NC
TAF SITES.
SCATTERED TO NUMEROUS SHOWERS...INCLUDING MODERATE TO HEAVY FREEZING
RAIN ONES OVER TRIAD TAF SITES WHERE TEMPERATURES WILL REMAIN IN THE
UPPER 20S TO AROUND 30 DEGREES THROUGH AROUND MIDNIGHT...WILL
TRANSITION TO LIQUID ONES AS TEMPERATURES RISE ABOVE FREEZING
SHORTLY THEREAFTER. MEANWHILE TO THE EAST...THE TEMPERATURE WILL
BREACH FREEZING AND RESULT IN FOLLOWING ALL LIQUID SHOWERY
PRECIPITATION FROM SOUTHEAST TO NORTHWEST FROM RWI TO RDU IN THE
NEXT FEW HOURS...WHILE THE TEMPERATURE HAS ALREADY RISEN ABOVE
FREEZING AT FAY.
AN EXPANSION OF LOCALLY DENSE FOG MAY ALSO ACCOMPANY THE ONGOING
LIFR CEILINGS TONIGHT...AS A WARM FRONT RETREATS ACROSS THE AREA.
THE APPROACH OF A POWERFUL UPPER LEVEL TROUGH AND PASSAGE OF AN
ASSOCIATED SURFACE LOW WILL RESULT IN THE EASTWARD MIGRATION OF A
BAND OF HEAVY RAIN AND ISOLATED THUNDERSTORMS ACROSS CENTRAL NC LATE
TONIGHT AND EARLY TUESDAY. WINDS WESTERLY FLOW AND VFR CONDITIONS
WILL DEVELOP IN THE WAKE OF THE BAND OF SHOWERS BY EARLY TUE
AFTERNOON. HOWEVER...A FAST-MOVING UPPER LEVEL DISTURBANCE...ON THE
HEELS OF THE LEAD ONE TONIGHT...WILL SWEEP EAST ACROSS THE MIDDLE
ATLANTIC STATES LATE TUE-EARLY TUE NIGHT. LOW VFR CEILINGS AND LIGHT
RAIN MAY RESULT...PARTICULARLY ACROSS NORTHERN TAF SITES.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NCZ008>010-025-026-040-041-073>075.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NCZ011-027-028-042-043-076-077.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ038-
039.
WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NCZ007-021>024.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...CBL
SHORT TERM...KRD
LONG TERM...WSS
AVIATION...26
AREA FORECAST DISCUSSION
NWS RALEIGH NC
303 PM EST MON FEB 15 2016
.SYNOPSIS...A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN
SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS
THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION
TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 PM MONDAY...
...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY
EXTENDED THROUGH 700 AM TUESDAY MORNING...
...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES
EXTENDED THROUGH MIDNIGHT TONIGHT...
...WINTER WEATHER ADVISORY FOR THE REST OF THE PIEDMONT EXTENDED
UNTIL 7 PM THIS EVENING...
RESIDUAL WEDGE OF ARCTIC HIGH PRESSURE WILL CONTINUE TO SUPPORT
LIGHT FREEZING RAIN/DRIZZLE ACROSS THE NORTHERN/NORTHWESTERN
PIEDMONT THROUGH THE EVENING...WITH A CHANGE OVER TO RAIN FROM SE TO
NW THROUGH THE EVENING HOURS AS A COASTAL WARM FRONT RETREATS INLAND
IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM APPROACHING FROM THE
SOUTHWEST.
KGSO RAOB SPECIAL 18Z RELEASE REVEALS THAT THE EXPECTED
STRONG/SIGNIFICANT WARMING ALOFT HAS INDEED MATERIALIZE...WARMER AND
QUICKER THAN FORECAST....WITH 6 C WARM NOSE NOTED ~875MB. A WARM
NOSE OF THIS MAGNITUDE WILL SUPPORT PRECIPITATION PRIMARILY IN THE
FORM OF FREEZING RAIN/DRIZZLE ACROSS THE FORECAST AREA UNTIL THE
CHANGE OVER TO RAIN AS THE COASTAL FRONT/PRE-FRONTAL WARM SECTOR
RETREATS SE TO NW INTO THE AREA. THE HRRR WHICH HAS DONE AN
EXCELLENT JOB WITH THE NEAR FREEZING SFC WET-BULB TRENDS ACROSS THE
FORECAST AREA(DELINEATES THE CHANGE-OVER FROM FREEZING RAIN TO
RAIN)BRINGS THE NEAR FREEZING SFC WET-BULB THROUGH THE TRIANGLE
BETWEEN 21 TO 00Z...AND THROUGH THE TRIAD BETWEEN 03 TO 06Z.
INTERMITTENT LIGHT FREEZING RAIN AND DRIZZLE WILL SUPPORT A TENTH TO
TWO-TENTHS OF AN INCH OF ICE ACROSS THE PIEDMONT...WITH THE HIGHEST
AMOUNTS IN THE HEART OF THE DAMMING REGION(WARNING AREA). THE
FREEZING RAIN THREAT ACROSS THE TRIAD AND PERSON COUNTY LOOKS TO BE
OVER SHORTLY AFTER MIDNIGHT...WITH TEMPERATURES RISING ABOVE
FREEZING AS THE PRE-FRONTAL WARM SECTOR OVERTAKES THE AREA. THE
WINTER STORM WARNING LIKELY TO BE CANCELLED EARLY(EXPIRES AT 7AM).
ATTENTION WILL QUICKLY TURN FROM FREEZING RAIN ACROSS THE NORTHWEST
PIEDMONT TO THE POTENTIAL FOR STRONG TO SEVERE STORMS ACROSS EASTERN
NC BY AROUND DAYBREAK AS NEGATIVE TILTED MID/UPPER WAVE AND
ATTENDANT DEEPENING SFC LOW APPROACH THE AREA FROM THE
WEST/SOUTHWEST. STRONG/DEEP ASCENT WITH IN THE RIGHT REAR QUADRANT
OF THE UPPER JET STREAK AND ALONG THE NOSE OF A POWERFUL 60-70KT LLJ
WILL SUPPORT A CONVECTIVE LINE OF HEAVY RAIN SHOWERS AND POSSIBLY A
FEW THUNDERSTORMS. AS THE LINE ENCOUNTERS THE BETTER INSTABILITY IN
THE EAST(MUCAPE 200-500 J/KG...STRONG TO SEVERE WIND GUST WILL BE
POSSIBLE...ALONG WITH AN ISOLATED TORNADO POSSIBLE.
WITH THE PRE-FRONTAL WARM SECTOR SPREADING NORTH INTO THE AREA...
TEMPERATURES WILL BE ON THE RISE OVERNIGHT...WARMING IN THE 40S
ACROSS THE WEST TO LOWER/MID 50S SE.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 255 PM MONDAY...
PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL
BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE
OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO
THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON.
INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH
ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE
FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A
MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING
ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60-
70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH
18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE
STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN
OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS
SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION
TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS
TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP
OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE
STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE
POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA.
OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 310 PM MONDAY...
UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY-
THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF
UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE
PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE
MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE
PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH
AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF
DEGREES BELOW FREEZING.
THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE
WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL
INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL
BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM
WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT
ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE
FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR.
MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL-
NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING
MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS
MONDAY BUT KEEP POPS AOB 20%.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 100 PM MONDAY...
...DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT...
MOSTLY IFR...(WITH INCREASINGLY LIFR/VLIFR)...CONDITIONS WILL
PERSIST THROUGH MUCH OF THE TAF PERIOD. FREEZING RAIN WILL
CONTINUE ACROSS THE REGION AND WILL EVENTUALLY TRANSITION TO RAIN
FROM SOUTHEAST TO NORTHWEST THROUGH THE EVENING HOURS.
THEN...HEAVY RAIN...INCLUDING A POTENTIAL FOR ELEVATED
THUNDERSTORMS...IS EXPECTED AT ALL TERMINALS BETWEEN MIDNIGHT AND
EARLY TUESDAY AS A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED
SURFACE LOW PRESSURE SYSTEM TRACK NORTHEAST ACROSS THE SOUTHERN
APPALACHIANS/CAROLINAS. IN ADDITION...LOW-LEVEL WIND SHEAR WILL
BECOME AN ISSUE (GENERALLY BETWEEN 06-12Z) AS A 50-60 KT SOUTHERLY
LOW-LEVEL JET DEVELOPS. DENSE FOG MAY ALSO BECOME A CONCERN
TONIGHT AND EARLY TUESDAY AS WARM AIR ADVECTS OVER COLDER
GROUND...ESPECIALLY IN THE TRIAD.
INT/GSO TERMINALS CAN EXPECT FZDZ/FZRA THE REMAINDER OF THE AFTERNOON
UNTIL TEMPERATURES RISE ABOVE FREEZING LATER THIS EVENING. FURTHER
EAST...THE RDU/RWI TERMINALS CAN EXPECT FZRA/FZDZ
UNTIL APPROXIMATELY 21Z. AS OF 18Z...TEMPS HAVE JUST ABOUT
REACHED FREEZING AT THE FAY TERMINAL AND THEREFORE ANY PRECIP
THAT FALLS NOW SHOULD BE RAIN. HEAVY RAIN AND ISOLATED
THUNDERSTORMS WILL MOVE ACROSS THE AREA AFTER MIDNIGHT BEFORE
EXITING THE REGION BETWEEN 15-18Z ON TUESDAY.
OUTLOOK...VFR CONDITIONS WILL RETURN IN THE WAKE OF A COLD
FRONTAL PASSAGE TUE AFTERNOON...WITH WESTERLY WINDS AT 10-15 KT
GUSTING UP TO 25 KT UNTIL SUNSET. VFR CONDITIONS ARE EXPECTED TO
PREVAIL THROUGH MID/LATE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NCZ008>010-025-026-040-041-073>075.
WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NCZ011-027-028-042-043-076-077.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ038-
039.
WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NCZ007-021>024.
&&
$$
SYNOPSIS...BADGETT
NEAR TERM...CBL
SHORT TERM...KRD
LONG TERM...WSS
AVIATION...KRD/VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1149 AM EST MON FEB 15 2016
.SYNOPSIS...
ARCTIC AIR WILL BE SLOW TO ERODE TODAY AS A WARM FRONT OFFSHORE
SLOWLY MOVES WESTWARD. THIS FRONT SHOULD MOVE INLAND TONIGHT WITH
A SOAKING RAIN EXPECTED INTO EARLY TUESDAY. DRY WEATHER IS
EXPECTED FOR THE REMAINDER OF THE WEEK WITH WARM TEMPERATURES
DEVELOPING NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...ONLY ISOLATED PATCHES OF LIGHT RAIN OVER THE
EXTREME SOUTHERN AND WESTERN PORTIONS OF THE FORECAST AREA AT THIS
TIME. THERE HAS BEEN SLIGHT WARMING THE FIRST FEW HOURS AFTER
SUNRISE AND AT 9 AM UTC THE SURFACE FREEZING LINE WAS ALONG A
LINE FROM HARTSVILLE THROUGH DILLON AND BLADENBORO TO PENDERLEA.
SO IF ANY PRECIPITATION FALLS INTO AREAS NORTH OF THIS LINE OVER
THE NEXT SEVERAL HOURS PATCHY FREEZING RAINY IS STILL POSSIBLE SO
WILL CONTINUE THE FREEZING RAIN ADVISORY.
A COASTAL FRONT CONTINUE TO LURK ALONG THE COAST WITH THE ILM
TEMPERATURE NOW UP TO 40 DEGREES. THE 14 UTC HRRR SHOW THE COASTAL
FRONT MAKING IT ONSHORE AROUND 17 UTC. AS THE FRONT SHIFTS ONTO
THE COAST THE ISENTROPIC FLOW CHANCES FOR MORE WIDE SPREAD
PRECIPITATION WILL INCREASE AT THE COAST BY THE AFTERNOON AND
SPREAD INLAND.
...FROM PREVIOUS DISCUSSION...
TEMPERATURES WILL RISE OVERNIGHT AS THE WARM FRONT MAKES MORE
RAPID WESTWARD PROGRESS WITH THE TOTAL BREAKDOWN OF THE COLD WEDGE
AND ITS SUPPORTING HIGH. THE MOST SUBSTANTIAL RAINFALL SHOULD
ARRIVE LATE TONIGHT AS A STRONG 500 MB DISTURBANCE ROLLS ACROSS
THE AREA. DEEP MOISTURE AND EVEN SOME ELEVATED CONVECTIVE
INSTABILITY SHOULD ENHANCE RAINFALL RATES AND IT`S POSSIBLE 0.50
TO 1.00 INCHES OF RAIN COULD FALL TONIGHT. WITH SURFACE-BASED
PARCELS LIKELY TO REMAIN STABLE I AM NOT CONCERNED ABOUT SEVERE
WEATHER POTENTIAL...HOWEVER DON`T BE SURPRISED IF THE RADAR SHOWS
SEVERAL ROTATING STORMS OUT OVER THE GULF STREAM LATE TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...THE LATEST SPC OUTLOOK CONTINUES TO DISPLAY A
MARGINAL RISK FOR SEVERE STORMS FOR PORTIONS OF THE FORECAST AREA
TUESDAY MORNING IN ASSOCIATION WITH A PRE-FRONTAL TROUGH/APPROACHING
COLD FRONT. AROUND DAYBREAK...GUIDANCE PLACES THE NORTH-SOUTH
EXTENDED COLD FRONT ACROSS THE CENTRAL CAROLINAS AS A PRE-FRONTAL
TROUGH AHEAD OF THE SYSTEM ESSENTIALLY PLACES OUR FORECAST AREA IN
THE WARM SECTOR. WITH PWATS IN THE 1 INCH TO 1.25 INCHES
RANGE...ANTICIPATE WIDESPREAD RAINFALL DURING THE MORNING
COMMUTE...HEAVY IN NATURE AT TIMES. SEVERE WEATHER WISE...WEAKER
LAPSE RATES ALONG WITH COLDER SEA TEMPERATURES AND LACK OF ANY
DIURNAL HEATING GIVEN EARLY ONSET OF ACTIVITY WILL RESTRICT
INSTABILITY. HOWEVER...WILL NOTE THE HEALTHY LOW LEVEL JET THAT WILL
BE IN PLACE OF AROUND 50 KTS AS WELL AS THE LOW LEVEL WIND SHEAR AS
NOTED BY THE 0-3KM HELICITY VALUES OF UP TO AROUND 200 M2/S2
POSSIBLE. AS A RESULT...INTERMITTENT DAMAGING WINDS ARE POSSIBLE.
AS THE COLD FRONT PUSHES OFFSHORE BY EARLY AFTERNOON...EXPECT
IMPROVING CONDITIONS AND A DRYING TREND BEHIND THE SYSTEM FOR THE
REST OF THE DAY ON TUESDAY. ANOTHER SHORTWAVE/FRONT WILL PUSH
THROUGH LATE OVERNIGHT TUESDAY INTO EARLY WEDNESDAY...BUT DO NOT
ANTICIPATE ANY PRECIPITATION WITH THIS FEATURE AS LATEST GUIDANCE
KEEPS AVAILABLE MOISTURE NORTH OF THE AREA.
MAINLY ABOVE NORMAL TEMPERATURES EXPECTED FOR THE SHORT TERM...WITH
HIGHS IN THE MID 60S ON TUESDAY AND AROUND 60 ON TUESDAY. LOW TO MID
40S FOR OVERNIGHT LOWS TUESDAY INTO WEDNESDAY WILL DIP DOWN INTO THE
MID TO UPPER 30S AS COLD AIR ADVECTION RAMPS UP BEHIND THE SECONDARY
COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...EXPECT A COOL AND DRY START TO THE EXTENDED
PERIOD WITH A GRADUAL WARMING TREND THROUGH THE REMAINDER OF THE
WEEK AS FAIRLY WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE
SOUTHEAST. HIGH TEMPERATURES ON THURSDAY WILL BE JUST BELOW NORMAL
IN THE MID TO UPPER 50S...CLIMBING INTO THE MID TO UPPER 60S BY THE
WEEKEND AND INTO EARLY NEXT WEEK. OVERNIGHT LOWS START OFF IN THE
UPPER 30S...REACHING THE MID TO UPPER 40S.
THE ONLY NOTABLE WEATHER SYSTEM WITHIN THE EXTENDED WILL BE
TOWARDS THE END OF THE PERIOD...STEMMING FROM A SURFACE LOW
PRESSURE SYSTEM WHICH MOVES ACROSS THE NORTHERN GREAT LAKES REGION
INTO SOUTHERN CANADA FRIDAY INTO SATURDAY. THOUGH THE TEMPORAL AND
SPATIAL NATURE OF THE EXTENDING FRONTAL BOUNDARY INTO THE
CAROLINAS REMAINS UNCERTAIN AT THIS TIME...EXPECT INCREASING
CLOUDS ON SUNDAY. ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO
MONDAY AS A RESULT WILL FALL AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE FREEZING.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...EVERYONE SHOULD BE ABOVE FREEZING SO NO LONGER A
FREEZING RAIN THREAT THIS AFTERNOON. PRECIPITATION WILL BE
VERY SPOTTY AND LIGHT. WINDS WILL VEER TO THE SOUTHEAST ALONG
THE COAST...WITH THE STUBBORN WEDGE HOLDING AT THE INLAND
TERMINALS AT LEAST INTO THIS EVENING.
OVERNIGHT...SOME PRETTY SERIOUS DYNAMICS MOVE INTO THE REGION
WITH A NEGATIVELY TILTED UPPER TROUGH AND GOOD HELICITY TOWARD
MORNING. A VERY STRONG LOW LEVEL JET WILL ADD TO THE MOISTURE
TRANSPORT...AND A BAND OF HEAVY SHOWERS WILL SWEEP THROUGH THE
REGION FROM 08Z-13Z. THERE COULD BE ENOUGH CAPE FOR SOME OF
THE WINDS AT 1-2K FEET TO COME DOWN TO THE SURFACE...THE REASON
FOR THE INTERMITTENT GUSTS TO 35 KTS. WOULD NOT BE SURPRISED
IF THEY WERE EVEN HIGHER AT THE COASTAL TERMINALS. TIME HEIGHT
SHOWS THAT THE CONVECTION SHOULD SHUT OFF FAIRLY ABRUPTLY AFTER
12Z...WITH STRONG SOUTHWEST WINDS EXPECTED.
EXTENDED OUTLOOK...VFR THROUGH FRIDAY MORNING. MVFR CONDITIONS
ARE POSSIBLE LATE FRIDAY AND SATURDAY WITH A WEAK FRONTAL
BOUNDARY MOVING INTO THE VICINITY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM MONDAY...A WARM FRONT CURRENTLY LOCATED 25-40 MILES
EAST OF THE BEACHES WILL CRAWL WESTWARD...APPROACHING THE COAST
NORTH OF CAPE FEAR AROUND NOON...AND FINALLY REACHING THE SC COAST
INCLUDING THE GRAND STRAND BY LATE IN THE DAY. THIS BOUNDARY WILL
SEPARATE S TO SE WINDS ON THE EAST (WARM) SIDE FROM NE WINDS ON
THE WEST (COLD) SIDE. STRENGTHENING SE WINDS WELL OFFSHORE SHOULD
LEAD TO INCREASING SWELL TODAY AND A SMALL CRAFT ADVISORY WILL
REMAIN POSTED EVEN FOR AREAS WHERE WIND SPEEDS REMAIN WELL BELOW
25 KNOTS.
BY TONIGHT THE WARM FRONT SHOULD MOVE COMPLETELY ONSHORE AND
STRENGTHENING SSE WINDS SHOULD REACH 25 KNOTS...ESPECIALLY ACROSS
THE WARMER SEA SURFACE TEMPERATURES GREATER THAN 10 MILES FROM
SHORE. SWELL WILL CONTINUE TO BUILD AND ITS POSSIBLE WE COULD SEE
SEA HEIGHTS EXCEEDING 10 FEET LATE TONIGHT NEAR CAPE FEAR.
WAVES OF RAIN DEVELOPING THIS MORNING MAY DIMINISH THIS
EVENING...HOWEVER RAIN SHOULD REDEVELOP LATE TONIGHT AND MAY BE
ACCOMPANIED BY A FEW STRONG THUNDERSTORMS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT THROUGH
TUESDAY AFTERNOON.
A PRE-FRONTAL TROUGH WILL PUSH ACROSS THE WATERS TUESDAY MORNING
ALLOWING FOR SOUTHERLY WINDS 15 TO 25 KTS TO PREVAIL...FOLLOWED BY A
COLD FRONT WHICH PUSHES OFFSHORE JUST TO THE NORTH AND WINDS VEERING
SOUTHWESTERLY TO WESTERLY...15 TO 20 KTS. WILL SEE A DECREASE IN
SUSTAINED WINDS TO AROUND 10 TO 15 KTS INTO EARLY WEDNESDAY MORNING
AS WEAK HIGH PRESSURE BEGINS TO BUILD IN...VEERING WINDS EVEN MORE
TO NORTHWEST. ALONG WITH WINDS...SEAS UP TO 6 TO 10 FT WILL WARRANT
A SMALL CRAFT ADVISORY FOR THE WATERS THROUGH THE DAY ON
TUESDAY...POSSIBLY CONTINUING INTO THE EVENING HOURS. SEAS DROP OFF
ON WEDNESDAY TO 3 TO 5 FT.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS
THE WATERS TOWARDS THE END OF THE WEEK. NORTHERLY WINDS 10 TO 15
KTS WILL PREVAIL ON THURSDAY...BECOMING NORTHEASTERLY ON FRIDAY AS
HIGH PRESSURE SHIFTS OFFSHORE. SEAS OF 2 TO 4 FT EXPECTED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
SCZ017-023-024.
NC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NCZ087-096.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST TUESDAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...DRH/TRA
SHORT TERM...SGL
LONG TERM...SGL
AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
334 PM CST MON FEB 15 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 334 PM CST MON FEB 15 2016
AN ACTIVE PATTERN WILL CONTINUE THE NEXT FEW DAYS...WITH A BRIEF
COOL-DOWN EXPECTED ON TUESDAY.
AS OF 21 UTC...LOW- AND MID-LEVEL SATURATION HAS BEEN TAKING PLACE
AT A SLOWER RATE THAN PERHAPS EXPECTED BASED ON A LACK OF SURFACE
PRECIPITATION REPORTS AND RELATIVELY ANEMIC REFLECTIVITY ON 0.5
DEGREE RADAR DATA. RECENT HIGH-RESOLUTION...RAPID-REFRESH MODEL
GUIDANCE /INCLUDING THE RAP AND HRRR/ STILL SUPPORTS THE FORMATION
OF LIGHT PRECIPITATION OVER WESTERN AND CENTRAL ND BY 00 UTC WITH
THE PASSAGE OF A MID-LEVEL SHORTWAVE TROUGH. HOWEVER...THAT MODEL
GUIDANCE HAS ALSO BEEN TRENDING LOWER WITH QPF...AND SINCE THAT IS
IN LINE WITH OBSERVATIONAL TRENDS WE BELIEVE THAT TO BE ACCURATE.
OUR FORECAST THUS CALLS FOR AN INCH OR LESS OF SNOW ACCUMULATION
THROUGH TONIGHT FROM NORTH CENTRAL ND INTO THE JAMES RIVER VALLEY.
THERMAL PROFILES SUPPORT RAIN INITIALLY OVER WESTERN AND PARTS OF
SOUTH CENTRAL ND...BEFORE A SWITCH TO POSSIBLE LIGHT SNOW BY THE
TIME THE BULK OF THE PRECIPITATION IS WINDING DOWN THIS EVENING.
WE ARE STILL CALLING FOR A PERIOD OF NORTHWEST WIND GUSTS TO ABOUT
30 MPH THIS EVENING BEHIND THE SHORTWAVE TROUGH AND ACCOMPANYING
SURFACE COLD FRONT BASED ON RAP-FORECAST 3-HOUR SURFACE PRESSURE
CHANGES OF 3-5 MB /HIGHEST IN SOUTHWEST ND/. GUIDANCE SUGGESTS AN
AREA OF STRATUS /LOW CLOUDS/ WILL FOLLOW THE SYSTEM LATE TONIGHT
INTO TUESDAY...WITH SOME HINTS OF ADDITIONAL...WEAK IMPULSES IN
LINGERING CYCLONIC NORTHWEST FLOW ALOFT. WE HAVE LOW POPS IN PLAY
FOR SOME LIGHT SNOW OVER CENTRAL ND AFTER 06 UTC TO ACCOUNT FOR
THAT...BUT FORECAST SOUNDINGS SUGGEST THE STRATUS DECK MIGHT BE
WARMER THAN -12 C...SUGGESTING SOME RISK OF FREEZING DRIZZLE. WE
CHOSE TO WITHHOLD THAT FROM THE FORECAST AT THIS POINT WITH WEAK
VERTICAL MOTION IN THAT LAYER PER MODEL GUIDANCE. MOREOVER...THE
PRECIPITATION-TYPE ALGORITHM OUTPUT FROM THE 12 UTC GLOBAL MODEL
OUTPUT AND MORE RECENT HRRR AND RAP GUIDANCE SUPPORTS LIGHT SNOW
AS THE PRIMARY TYPE WITH ANY LIGHT PRECIPITATION THAT MAY OCCUR
AFTER MIDNIGHT AND INTO EARLY TUESDAY MORNING. THAT WILL REQUIRE
MONITORING THOUGH.
ON TUESDAY...A SURFACE RIDGE WILL BUILD INTO EASTERN ND AND WILL
BRING A COLDER DAY TO THE AREA. WARM AIR ADVECTION WILL BEGIN TO
THE WEST ACROSS MT THOUGH AND THE 12 UTC GUIDANCE ALL SUGGESTS A
BAND OF LIGHT SNOW WILL MOVE INTO WESTERN ND DURING THE DAY AND
INTO CENTRAL ND BY EARLY TUESDAY EVENING. THIS WOULD BE ANOTHER
LIGHT QPF EVENT WITH LITTLE IN THE WAY OF IMPACTS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 334 PM CST MON FEB 15 2016
ACTIVE PERIOD WITH SEVERAL SYSTEMS SLIDING THROUGH WESTERN AND
CENTRAL NORTH DAKOTA...APPROXIMATELY ONE EVERY 24HR TO 48HR. WE
ARE LIKELY TO SEE A COMBINATION OR RAIN...SNOW...AND/OR LIGHT
FREEZING DRIZZLE AT TIMES WITH THESE SYSTEMS. SUCCESSIVE WARM AIR
ADVECTION/PRECIPITATION EVENTS WILL EVENTUALLY RESULT IN A GRADUAL
WARMING TREND LATER IN THE WEEK. THE NAEFS 850T-500T SHOWS A
FAIRLY STRONG THERMAL RIDGE SHIFTING OVER NORTH DAKOTA THURSDAY.
850 TEMPS OF +8C TO +10C WILL BE COMMON RESULTING IN SURFACE
HIGHS IN THE 40S TO LOWER 50S.
FOR TUESDAY NIGHT INTO WEDNESDAY MORNING...FIRST SHORTWAVE IN THE
LONG TERM PERIOD EMBEDDED WITHIN A NORTHWEST FLOW WILL MOVE FROM
WITH A SURFACE LOW REFLECTED IN SOUTHEAST MONTANA SHIFTING INTO
CENTRAL SOUTH DAKOTA THROUGH WEDNESDAY MORNING.
ANOTHER...STRONGER SHORTWAVE TROUGH HAS BEEN CONSISTENTLY SHOWN TO
CROSS THE REGION THURSDAY NIGHT INTO FRIDAY BY THE LAST SEVERAL
RUNS OF THE GFS AND ECMWF. A MIX OF PRECIPITATION IS POSSIBLE WITH
THAT WAVE...AND STRONG WINDS ARE POSSIBLE ON ITS BACK SIDE IF THE
12 UTC GFS AND ECMWF ARE RIGHT WITH 850-MB WINDS UP TO 55 KT FROM
THURSDAY NIGHT INTO FRIDAY.
FINALLY...THERE ARE HINTS OF ONE MORE SHORTWAVE TROUGH PASSAGE ON
SATURDAY OR SUNDAY...SUPPORTIVE OF MORE LOW POPS IN THAT PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 334 PM CST MON FEB 15 2016
A MIX OF RAIN AND SNOW IS POSSIBLE THROUGH THIS EVENING. MVFR
CEILINGS AND VISIBILITIES ARE LIKELY BY EVENING...ESPECIALLY IN
CENTRAL ND. SOME GUIDANCE DOES SHOW AT LEAST SOME POTENTIAL FOR
IFR CEILINGS BY THE EARLY MORNING HOURS ON TUESDAY OVER KMOT/KJMS.
THE OTHER CONCERN WILL BE BREEZY WINDS FROM THE NORTHWEST OVER THE
STATE FROM 00-06Z TUESDAY MORNING. WINDS COULD GUST AS HIGH 30
KNOTS OVER SOUTHWEST...WEST CENTRAL...AND CENTRAL ND.
&&
.HYDROLOGY...
ISSUED AT 334 PM CST MON FEB 15 2016
ICE RESTRICTIONS IN THE CHANNEL AND SOME CONTRIBUTION FROM LOCAL
RUNOFF DUE TO RECENT SNOWMELT HAS CAUSED THE MISSOURI RIVER TO
RISE IN THE BISMARCK/MANDAN AREA. WE ARE MONITORING THE SITUATION
CLOSELY AND ARE PROVIDING INFORMATION IN A HYDROLOGIC OUTLOOK ON
OUR WEB PAGE. RIGHT NOW THE MAIN MESSAGE WE ARE CONVEYING IS THAT
THERE WILL BE SHARP FLUCTUATIONS...WITH RAPID RISES FOLLOWED BY
LOWER LEVELS...UNTIL THE ICE IS NATURALLY REMOVED BY MIDWEEK.
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CJS
LONG TERM...KS/CJS
AVIATION...ZH/CJS
HYDROLOGY...CJS/KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
116 PM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 115 PM CST MON FEB 15 2016
NO CHANGES NEEDED FOR THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS
SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE
BLEND FOR NOW.
A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE
OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME
WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER
THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR
IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE
WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES
SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF
CLOUD COVER.
NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA
THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING
BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT
GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY
WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT
STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL
NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST
SW OF THE FA.
FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING
COOLER TEMPERATURES TO THE REGION TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH
BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE
WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR
WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY
LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO.
HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND
WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO
RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY.
WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD.
THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID-
LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH
THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO
MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE
DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS
AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH
BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE
AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL
FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER
AIR FEATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 115 PM CST MON FEB 15 2016
TAFS WILL BE A CHALLENGE TODAY AS DENSE FOG IMPACTS THE DVL
REGION...WHERE VSBYS HAVE GONE UP...STRATUS OVER GFK/TVF AREA AND
LIGHT MIXED PRECIP MOVING INTO BJI. BELIEVE THE PRECIP WILL MOVE OUT
OF BJI OVER THE NEXT COUPLE OF HOURS BUT NOW LESS CONFIDENT GFK-TVF-
BJI WILL SEE MVFR CIGS IMPROVE. A SHOT OF LIGHT SNOW WILL MOVE
ACROSS THE REGION TONIGHT...ALTHOUGH MODELS DIFFER IN THE TRACK OF
THE SNOW. DVL WILL CERTAINLY SEE SOME SNOW WITH CIGS REMAINING
IFR...AND FAR WILL SEE MVFR CIGS OVERNIGHT AS IT MOVES THROUGH. LESS
CONFIDENT ON THE GFK-TVF REGION ALTHOUGH REDUCED VSBYS TO IFR CONDS
IS POSSIBLE WITH SHSN THIS EVENING. WINDS WILL BECOME LIGHT AT
BJI...AND EXPECT VSBYS TO DROP TO IFR CONDS THERE AS FZFG IMPACTS
THE AERODROME BETWEEN 00Z AND 06Z. MOST LIKELY SCENARIO WILL BE
PREDOMINANT MVFR WITHIN AND EAST OF THE VALLEY...PREDOMINANT IFR AT
DVL...AND INTERMITTENT IFR CONDS AT FAR/BJI.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 PM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 1250 PM CST MON FEB 15 2016
WE INCREASED POST-FRONTAL WIND SPEEDS TO ADVERTISE GUSTS TO AROUND
30 MPH FOR A TIME THIS EVENING OVER MUCH OF THE AREA BASED ON 3-5
MB/3 HOUR PRESSURE RISES SIMULATED BY RECENT RAP RUNS. THE REST OF
THE FORECAST LOOKS ON TRACK WITH RADAR RETURNS STEADILY INCREASING
AS OF MIDDAY...WITH LOW-LEVEL SATURATION AND THE RESULTANT CHANCE
OF PRECIPITATION STILL EXPECTED TO INCREASE IN MANY PLACES THIS
AFTERNOON.
SEE THE HYDROLOGY SECTION BELOW FOR INFORMATION ON HIGH WATER ON
THE MISSOURI RIVER IN THE BISMARCK-MANDAN AREA.
UPDATE ISSUED AT 934 AM CST MON FEB 15 2016
ONLY MINOR CHANGES WERE NEEDED FOR THIS LATEST UPDATE. DID BLEND
OBSERVATION TRENDS TO THE FORECAST THROUGH 18 UTC...AND TWEAKED
PRECIPITATION CHANCES TO MATCH WHAT A BLEND OF HIGH RESOLUTION
GUIDANCE SUGGESTS FOR LATER THIS AFTERNOON. ADDITIONALLY...NUDGED
HIGH TEMPERATURES UP BY A DEGREE OR TWO IN THE SOUTHWEST AND SOUTH
CENTRAL.
UPDATE ISSUED AT 644 AM CST MON FEB 15 2016
NO CHANGES OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC.
WEBCAMS ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER
VALLEY SUGGEST FOG CONTINUES TO BE PATCHY. ONE THING TO MONITOR
IS POTENTIAL SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND
JAMES RIVER VALLEY FOR LATER TODAY AND INTO THE EVENING. THE 10-11
UTC RAP/HRRR ITERATIONS...06 UTC NAM AND 00 UTC HI-RES WINDOW WRF
ARW/NMM ALL SUGGEST THE POSSIBILITY FOR MORE THAN TWO INCHES OF
ACCUMULATION WITH STEEP MID LEVEL LAPSE RATES AND NEGATIVE EPV
ALOFT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CST MON FEB 15 2016
AN UPPER LEVEL LOW OVER NORTH CENTRAL CANADA AND A RIDGE OVER THE
WEST COAST WILL KEEP NORTHWESTERLY FLOW ALOFT OVER THE STATE TODAY.
A WEAK SHORTWAVE IN THE FLOW WAS CURRENTLY MOVING SOUTHEAST ACROSS
NORTH CENTRAL NORTH DAKOTA. REGIONAL RADARS WERE DETECTING SOME
LIGHT RETURNS ASSOCIATED WITH THE SHORTWAVE...AND THE BOTTINEAU DOT
CAM CONFIRMED LIGHT SNOW FALLING AND REACHING THE GROUND. THUS ADDED
A MENTION OF LIGHT SNOW EARLY THIS MORNING NORTH CENTRAL.
A WEAK SURFACE WARM FRONT/TROUGH EXTENDED FROM MANITOBA TO NEAR
DEVILS LAKE TO NEAR BISMARCK AND SOUTH. LARGE AREA OF FOG AND LOW
CLOUDS AHEAD OF THE WARM FRONT OVER MINNESOTA AND THE RED RIVER
VALLEY. JAMESTOWN HAD BEEN REPORTING VERY LOW VISIBILITY IN FOG AND
LOW CLOUDS BEFORE MIDNIGHT...THEN CONDITIONS IMPROVED WITH WEAK
SOUTHWESTERLY FLOW AND THE APPROACH OF THE WARM FRONT.
A STRONGER SHORTWAVE WAS CURRENTLY OVER SOUTHERN ALBERTA. THE
LEADING EDGE OF THE SHORTWAVE ENERGY IS FORECAST TO ENTER WESTERN
NORTH DAKOTA BY MID TO LATE MORNING...THEN CONTINUE MOVING
SOUTHEAST...EXITING NORTH DAKOTA INTO SOUTHERN MINNESOTA LATE
TONIGHT. PRECIPITATION IS EXPECTED TO BEGIN IN THE SOUTHWEST BEFORE
NOON...SPREADING INTO CENTRAL NORTH DAKOTA THIS AFTERNOON...ENDING
IN THE WEST DURING THE EVENING...AND DISSIPATING IN CENTRAL NORTH
DAKOTA LATE TONIGHT.
PRECIPITATION TYPE IS THE CHALLENGE...AS WARM AIR BEHIND THE
AFOREMENTIONED SURFACE WARM FRONT SHOULD ALLOW LIGHT SNOW SOUTHWEST
TO CHANGEOVER TO LIGHT RAIN AS TEMPERATURES RISE INTO THE 30S AND
LOWER 40S...WITH WARM TEMPERATURES ALOFT AS WELL. FARTHER NORTH LOOK
FOR A MIX OF RAIN AND SNOW AS TEMPERATURES THERE WILL BE MAINLY IN
THE 20S...REACHING INTO THE LOW TO MID 30S DURING THE DAY...AND AS
TEMPERATURES ABOVE THE SURFACE WILL RISE FOR A SHORT TIME TO ALLOW
LIGHT SNOW CHANGING TO RAIN...THEN AS A SURFACE COLD FRONT FOLLOWS
THE VIGOROUS UPPER LEVEL SHORTWAVE...THE PRECIPITATION IN THE NORTH
CENTRAL CHANGES BACK OVER TO LIGHT SNOW LATE AFTERNOON. LIGHT
SNOW ACCUMULATIONS OF AROUND AN INCH ARE EXPECTED FROM BOTTINEAU TO
RUGBY AND THE TURTLE MOUNTAINS THROUGH TONIGHT.
LOWS TONIGHT SHOULD RANGE FROM THE TEENS NORTH CENTRAL TO THE 20S
WEST AND SOUTH.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CST MON FEB 15 2016
ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST.
THE 00 UTC SUITES ARE IN GOOD AGREEMENT ON A BROAD UPPER LEVEL
RIDGE BUILDING ACROSS THE CENTRAL CONUS THIS WEEK...WITH
RESULTANT ABOVE NORMAL TEMPERATURES FOR THE PERIOD. THE 00 UTC
NAEFS MEAN 850 MB TEMPERATURE ANOMALIES ARE FORECAST TO CLIMB TO
THEIR 97.5 TO 99.5+ PERCENTILES BY THURSDAY ACROSS WESTERN AND
CENTRAL NORTH DAKOTA. THIS SUPPORTS THE POTENTIAL FOR WIDESPREAD
50S FOR HIGHS ALONG AND WEST OF THE MISSOURI RIVER BY THURSDAY.
REGARDING PRECIPITATION...A WEAK CLIPPER IS FAVORED ACROSS WESTERN
AND CENTRAL NORTH DAKOTA ON TUESDAY. PRECIPITATION IS EXPECTED TO
BE RAIN ACROSS THE SOUTHWEST...WITH LIGHT SNOW ELSEWHERE GIVEN A
SURFACE BASED WARM LAYER. NEW SNOW ACCUMULATIONS OF ONE INCH OR
LESS ARE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CST MON FEB 15 2016
CLOUDS WILL BE ON THE INCREASE FROM WEST TO EAST THROUGH THE
AFTERNOON OVER NORTH DAKOTA. SOME LIGHT RAIN SHOWERS WILL DEVELOP
OVER THE SOUTHWESTERN PART OF THE STATE THIS AFTERNOON AND SPREAD
EAST THROUGH THE OVERNIGHT. PRECIPITATION MAY FALL AS A MIX OF RAIN
AND SNOW AT KMOT LATE THIS AFTERNOON...AND AS ALL SNOW AT KJMS
TONIGHT. THE RAIN SNOW TRANSITION ZONE WILL LIKELY RUN FROM THE
NORTHWEST TO THE SOUTHEAST NEAR OR ALONG THE BOUNDARY OF THE
MISSOURI RIVER. MVFR CEILINGS AND VISIBILITIES LOOK LIKELY BEGINNING
LATE THIS AFTERNOON...HOWEVER SOME GUIDANCE DOES SHOW AT LEAST SOME
POTENTIAL FOR IFR CEILINGS BY THE EARLY MORNING HOURS ON TUESDAY
OVER KMOT/KJMS. THE OTHER CONCERN WILL BE BREEZY WINDS FROM THE
NORTHWEST OVER THE STATE FROM 00-06Z TUESDAY MORNING. WINDS COULD
GUST AS HIGH 30 KNOTS OVER SOUTHWEST...WEST CENTRAL...AND CENTRAL
ND.
&&
.HYDROLOGY...
ISSUED AT 1250 PM CST MON FEB 15 2016
ICE RESTRICTIONS IN THE CHANNEL AND SOME CONTRIBUTION FROM LOCAL
RUNOFF DUE TO RECENT SNOWMELT HAS CAUSED THE MISSOURI RIVER TO
RISE IN THE BISMARCK/MANDAN AREA. WE ARE MONITORING THE SITUATION
CLOSELY AND ARE PROVIDING INFORMATION IN A HYDROLOGIC OUTLOOK ON
OUR WEB PAGE. THAT OUTLOOK WILL BE UPDATED TO REFLECT OUR LATEST
EXPECTATIONS THIS AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS/ZH
SHORT TERM...JV
LONG TERM...AYD
AVIATION...ZH
HYDROLOGY...CJS/KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1050 AM CST MON FEB 15 2016
.UPDATE...
ISSUED AT 1050 AM CST MON FEB 15 2016
WE HAVE ADDED FOG TO ALL AREAS THROUGH 18Z...GETTING SOME FOG NOW
WITH FAIRLY LOW VSBYS IN DVL BASIN.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS
SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE
BLEND FOR NOW.
A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE
OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME
WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER
THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR
IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE
WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES
SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF
CLOUD COVER.
NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA
THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING
BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT
GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY
WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT
STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL
NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST
SW OF THE FA.
FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING
COOLER TEMPERATURES TO THE REGION TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 335 AM CST MON FEB 15 2016
NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH
BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE
WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR
WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY
LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO.
HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND
WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO
RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY.
WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD.
THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID-
LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH
THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO
MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE
DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS
AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH
BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE
AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL
FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER
AIR FEATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 626 AM CST MON FEB 15 2016
ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS
STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE
SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW
LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY
VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE
AFTERNOON/EVENING AS NEXT WAVE DROPS SE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...DK
SHORT TERM...VOELKER
LONG TERM...MAKOWSKI/VOELKER
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1224 PM CST MON FEB 15 2016
.AVIATION...
WITH THE COLD FRONT CONTINUING TO MAKE ITS WAY ACROSS SE TX THIS
AFTN WE SHOULD BE SEEING THE END OF THE PCPN/CLOUDS FROM THE NW.
NO REAL CHANGES WITH FROPA TIMING WITH THE 18Z TAF PACKAGE...NOR
WITH THE FCST OF ONSHORE WINDS RETURNING AREAWIDE TOMORROW MORN.
WE COULD SEE VERY PATCHY FOG OVERNIGHT AT AIRPORTS CLOSER TO THE
COAST...OTHERWISE THIS WILL MAINLY BE A VFR FCST. 41
&&
.PREV DISCUSSION... /ISSUED 1027 AM CST MON FEB 15 2016/
MORNING FORECAST UPDATE...OVERALL FORECAST ON TRACK WITH MAINLY
SHOWERS ACROSS SE TX. BULK OF THE ACTIVITY HAS BEEN CONFINED TO
HOUSTON SOUTHWARD ALONG THE COAST. MOST SHOWER ACTIVITY STRETCHES
FROM BAY CITY TO BEAUMONT. THERE MAY BE A FEW EMBEDDED
THUNDERSTORMS BUT MOST OF THE THUNDERSTORM ACTIVITY HAS PUSHED
EAST INTO LOUISIANA. SFC ANALYSIS AT 16Z HAS COLD FRONT ON THE
DOOR STEP OF CROCKETT TO CALDWELL. EXPECT FRONT TO PUSH THROUGH
WITH NOT MUCH SHOWER OR THUNDERSTORM ACTIVITY. UPDATED FORECAST ON
LATEST RADAR TRENDS AND LATEST HRRR SHORT RANGE DATA THAT SEEMS TO
BE DOING OKAY WITH EVOLUTION. IT HAS BEEN OVER DOING SHOWER
ACTIVITY FOR TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 47 77 49 76 / 10 0 0 0 0
HOUSTON (IAH) 76 50 77 49 75 / 20 0 0 0 0
GALVESTON (GLS) 70 56 71 56 68 / 30 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1135 AM CST MON FEB 15 2016
.AVIATION...
THE COLD FRONT HAS MOVED THROUGH ALL THE TERMINALS AND SKIES HAVE
CLEARED. WINDS HAVE SHIFTED TO THE NORTH. NORTH WINDS WILL
CONTINUE THROUGH THE AFTERNOON AT 10 TO 15 KTS. PREVIOUS TAFS HAD
HIGHER GUSTS...BUT SO FAR WINDS BEHIND THE FRONT HAVE NOT BEEN
GUSTY SO HAVE TAKEN OUT GUSTS. HOWEVER...WITH ADDITIONAL HEATING
HIGHER GUSTS ARE POSSIBLE THIS AFTERNOON. CIGS WILL BE MAINLY
CLEAR THROUGH THIS PERIOD. WINDS WILL SHIFT TO THE SOUTHWEST
TUESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 402 AM CST MON FIB 15 2016/
SHORT TERM (TODAY THROUGH TUESDAY)...
MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG
AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON
TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE
RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED
TODAY AND TUESDAY.
WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH
PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME
LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER
LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR
LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH-
CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE
FRONT THAT IS NOW LOCATED ALONG A DALLAS TO WACO TO OZONA LINE.
LOW CLOUDS AND AREAS OF FOG WILL OCCUR NOW THROUGH 8-10AM WITH
SOME POCKETS OF DENSE FOG POSSIBLE ALONG WITH DRIZZLE/MIST WHERE
THE FOG/LOW CLOUDS ARE THICKER NEAR THE SURFACE.
THE WEAK BOUNDARY WILL SWEEP THROUGH THE HILL COUNTRY AND AUSTIN BY
7-9AM AND THROUGH SAN ANTONIO BEFORE 11AM. RAPID CLEARING OF CLOUDS
IS EXPECTED BEHIND THE BOUNDARY WITH SUNNY CONDITIONS AND BREEZY
NORTH WINDS EXPECTED THIS AFTERNOON. THE COMBINATION OF WINDS
GUSTING TO NEAR 20-25 MPH AND THE DRIER AIR MOVING IN WILL
PROMOTE ELEVATED FIRE WEATHER CONDITIONS ACROSS THE RIO GRANDE
PLAINS AS RELATIVE HUMIDITY VALUES DIP NEAR TO JUST BELOW 20% THIS
AFTERNOON.
FOR TUESDAY...A SLIGHTLY COOLER MORNING IS EXPECTED GIVEN THE
DRIER AIR AND NEAR CALM WINDS BUT READINGS WILL BE NEAR CLIMATE
NORMALS. EXPECTED CLEAR SKIES WITH PLENTY OF SUN WITH HIGHS
REACHING ABOVE NORMAL INTO THE UPPER 70S AND LOW 80S. SOME
LOCATIONS IN THE RIO GRANDE PLAINS COULD REACH INTO THE MID 80S.
LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
WELL ABOVE NORMAL TEMPERATURES OF 10-15F DEGREES ARE EXPECTED MID TO
LATE WEEK WITH A SLIGHT COOL DOWN INTO THE WEEKEND. DRY
CONDITIONS WILL ALSO REMAIN UNTIL EARLY NEXT WEEK WHERE A MORE
SUBSTANTIAL COLD FRONT AND BETTER RAIN CHANCES COULD OCCUR.
CONUS PATTERN MID TO LATE WEEK WILL FEATURE SURFACE HIGH PRESSURE
OVER THE MID-MS RIVER VALLEY WITH SOUTHEAST LOW-LVL FLOW THAT VEERS
TO THE SOUTHWEST/WEST IN THE MID-LVL OVER TEXAS. THIS TYPE OF
PATTERN ALONG WITH A BUILDING H5 RIDGE AND H925 TEMPS 23-16C FROM
WEST TO EAST WILL SUPPORT UPPER 70S TO MID 80S. WHILE IT WILL BE
WARM...RECORD TEMPERATURES DO NOT LOOK TO BE IN JEOPARDY AS THOSE
VALUES ARE ALREADY WELL INTO THE 90S. MORNING CLOUDS LOOK TO
RETURN THURSDAY AND FRIDAY BUT QUICK MIX OUTS BY MID MORNING HOURS
TO PARTLY AND MOSTLY SUNNY SKIES WILL OCCUR. SLIGHTLY COOLER H925
AIR WILL PIVOT IN ACROSS THE REGION THIS WEEKEND AS THE H5 RIDGE
BREAKS DOWN AND SOME WEAK IMPULSES MIGRATE OVER THE REGION THAT
WILL CREATE SOME MORE MID-LVL CLOUDS.
GLOBAL LONG RANGE MODELS CONTINUE TO HINT AT IN DECENT ACCORD A MORE
ACTIVE SOUTHERN JET STREAK BRANCH OVER SOUTH TEXAS NEXT SUNDAY-
TUESDAY. THIS ACTIVE BRANCH WILL HELP BUCKLE THE FLOW WITH ENHANCED
TROUGHING THAT, IN CONJUNCTION WITH THE POLAR JET, WILL AID A
STRONGER CANADIAN ORIGINATED FRONT TO APPROACH THE AREA AROUND
MONDAY. THIS STRONGER FRONT AND BETTER DYNAMIC SUPPORT SHOULD ALLOW
FOR BETTER RAIN/STORM CHANCES IN THIS TIME FRAME. WILL CONTINUE
TO MONITOR THE EVOLUTION OF THIS SYSTEM AND ITS LIKELY MORE
WIDESPREAD RAIN SIGNAL FOR THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 75 47 81 50 82 / 10 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 75 43 80 45 81 / 10 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 77 44 81 47 81 / - 0 0 0 0
BURNET MUNI AIRPORT 73 44 79 46 80 / - 0 0 0 0
DEL RIO INTL AIRPORT 80 46 85 51 87 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 73 44 80 46 80 / 10 0 0 0 0
HONDO MUNI AIRPORT 80 42 82 46 83 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 44 79 46 79 / - 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 76 46 79 47 80 / 10 0 0 0 0
SAN ANTONIO INTL AIRPORT 77 46 80 49 82 / 0 0 0 0 0
STINSON MUNI AIRPORT 79 46 82 48 82 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...05
SYNOPTIC/GRIDS...RUNYEN
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1118 AM CST MON FEB 15 2016
.AVIATION...
NO AVIATION WEATHER CONCERNS FOR THE NEXT 24 HOURS. SURFACE WINDS
WILL SWING FROM NORTH TO SOUTHWEST TODAY THEN BACK TO THE NORTH
TUESDAY MORNING AS A FRONT MOVES THROUGH. NORTH-NORTHEAST WINDS
WILL BECOME BREEZY WITH THE FROPA BY LATE TUESDAY MORNING.
&&
.PREV DISCUSSION... /ISSUED 440 AM CST MON FEB 15 2016/
AVIATION...
VFR. LIGHT NW WINDS BECMG SWLY AROUND 11 KNOTS BY MIDDAY.
PREV DISCUSSION... /ISSUED 339 AM CST MON FEB 15 2016/
SHORT TERM...
IN THE WAKE OF A MINOR TROUGH THAT MANAGED TO GENERATE MID-LEVEL
CLOUDS AND VIRGA OVER OVER THE SERN PANHANDLE LAST NIGHT...BROAD
SURFACE RIDGING CENTERED IN NERN NM WILL TRANSLATE SEWD UNDER DRY
NW FLOW. DEPARTURE OF THIS RIDGE BY LATE MORNING AND SUBSEQUENT
DOWNSLOPE FLOW WILL AID IN LEE TROUGH DEVELOPMENT OVER EASTERN NM
COMPLETE WITH SOME BREEZY W-SW WINDS LOCALLY. CONTINUE TO SIDE
WITH THE DRIER RUC AND HRRR FOR AFTERNOON DEWPOINTS AS REMAINING
GUIDANCE HAS BEEN TOO GENEROUS WITH THESE IN RECENT DAYS...IF NOT
WEEKS. UPSHOT OF THIS IS THAT MILDER MAV HIGH TEMPS REMAIN FAVORED
OVER THE COOL SUPERBLEND. SW WINDS TONIGHT WILL VEER W-NW BEFORE
DAYBREAK TUE IN ADVANCE OF A DECAYING COLD FRONT AND DISTANT
TROUGH TRACKING ALONG THE MIDDLE MISSOURI RIVER VALLEY.
LONG TERM...
QUIET WEATHER WILL CONTINUE THROUGH MUCH OF THE WEEK AS DRY
NORTHWEST FLOW GRADUALLY TRANSITIONS TO SOUTHWESTERLY/ZONAL BY THE
END OF THE WEEK. A WEAK FRONT WILL PUSH THROUGH EARLY TUESDAY
KEEPING TEMPERATURES IN THE MID 60S TO LOW 70S FOR HIGHS AND LOWS
IN THE MID 30S TO LOWER 40S. RIDGE WILL MOVE OVER THE REGION ON
WEDNESDAY WHICH WILL START WARMING TEMPERATURES WELL ABOVE NORMAL
FOR MID-WEEK. WARMEST DAY STILL LOOKS TO BE THURSDAY WHEN
SOUTHWESTERLY FLOW WILL DEVELOP AT THE SURFACE HELPING TO BOOST
HIGHS INTO THE LOW 80S.
WEAK SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE FRIDAY THROUGH
THE END OF THE FORECAST. THIS WILL KEEP BOUNDARY LAYER MOISTURE IN
PLACE EITHER OVER OR NEAR THE FORECAST AREA THROUGH SOME POINT
OVER THE WEEKEND OR FIRST PART OF NEXT WEEK. THERE CONTINUES TO BE
DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE ARRIVAL OF A COLD
FRONT AT THE END OF THE UPCOMING WEEKEND OR FIRST PART OF NEXT
WEEK. DIFFERENCES SURROUND THE STRENGTH OF A WAVE/CLOSED LOW THAT
SWINGS OUT ACROSS THE NORTHERN PLAINS OVER THE GREAT LAKES. ECMWF
DEVELOPS A CLOSED LOW RESULTING IN A STRONGER FRONT THAT PUSHES
THROUGH ON SUNDAY WHILE THE GFS IS MUCH WEAKER THAN THE ECMWF.
MODELS TRY TO BREAK OUT PRECIPITATION IN VARYING AMOUNTS AND
COVERAGE AND SUPERBLEND OUTPUT CONTINUES TO CARRY POPS FOR
SATURDAY INTO SUNDAY. BECAUSE OF THE DIFFERENCES IN THE MODELS...
ECMWF IS MUCH DRIER THAN THE GFS...WILL KEEP POPS OUT OF THE
FORECAST FOR NOW UNTIL WE SEE IF THE EXTENDED RANGE FORECAST CAN
COME INTO BETTER CONSENSUS.
JORDAN
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1027 AM CST MON FEB 15 2016
.DISCUSSION...
MORNING FORECAST UPDATE...OVERALL FORECAST ON TRACK WITH MAINLY
SHOWERS ACROSS SE TX. BULK OF THE ACTIVITY HAS BEEN CONFINED TO
HOUSTON SOUTHWARD ALONG THE COAST. MOST SHOWER ACTIVITY STRETCHES
FROM BAY CITY TO BEAUMONT. THERE MAY BE A FEW EMBEDDED
THUNDERSTORMS BUT MOST OF THE THUNDERSTORM ACTIVITY HAS PUSHED
EAST INTO LOUISIANA. SFC ANALYSIS AT 16Z HAS COLD FRONT ON THE
DOOR STEP OF CROCKETT TO CALDWELL. EXPECT FRONT TO PUSH THROUGH
WITH NOT MUCH SHOWER OR THUNDERSTORM ACTIVITY. UPDATED FORECAST ON
LATEST RADAR TRENDS AND LATEST HRRR SHORT RANGE DATA THAT SEEMS TO
BE DOING OKAY WITH EVOLUTION. IT HAS BEEN OVER DOING SHOWER
ACTIVITY FOR TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 47 77 49 76 / 10 0 0 0 0
HOUSTON (IAH) 76 50 77 49 75 / 20 0 0 0 0
GALVESTON (GLS) 70 56 71 56 68 / 30 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
352 PM EST MON FEB 15 2016
.SYNOPSIS...
HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS WILL
SLOWLY MOVE NORTHEAST TONIGHT...AS LOW PRESSURE MOVES FROM THE LOWER
MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. ANOTHER LOW WILL
TRACK OUT OF SOUTHERN CANADA TONIGHT INTO THE TENNESSEE VALLEY BY
LATE TUESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS 352 PM EST MONDAY...
WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON TUESDAY FOR ENTIRE
AREA.
THE 18Z RNK SOUNDING SHOWED THE WARM LAYER AROUND 3KFT...WHILE THE
TEMPERATURE AT SURFACE AT BCB WAS BELOW FREEZING. LIGHT SURFACE
WINDS BECOME SOUTHWEST ALOFT. THIS COLD AIR DAMMING AGAINST THE
APPALACHIANS WILL MAINTAIN A WEDGE OF SUB-FREEZING NEAR SURFACE
THROUGH THE EVENING AND INTO TONIGHT. THE WINTRY MIXTURE OF
SNOW...SLEET...FREEZING RAIN AND RAIN WILL CONTINUE TONIGHT.
LOW PRESSURE WILL MOVE FROM THE TENNESSEE VALLEY TO THE CENTRAL
APPALACHIANS TONIGHT AND NORTHWARD INTO PENNSYSLVANIA BY 18Z
TUESDAY. THE COLD AIR WILL HOLD THE LONGEST ACROSS THE NORTH
ESPECIALLY ALLEGHANY HIGHLANDS INTO TUESDAY MORNING. SHORTWAVE
COMING OUT OF THE SOUTHERN PLAINS CROSSES THE TUESDAY WITH A MIXTURE
OF RAIN AND SNOW IN THE WESTERN HIGHER ELEVATIONS.
FOR POPS THIS EVENING LEANED TOWARDS THE HRRR SOLUTION WHICH CAPTURED
THE DRIER SLOT AND MIXED PRECIPITATION THE BEST. THEN...SHAPED
POPS TOWARDS THE NAM FOR LATE TONIGHT INTO TUESDAY MORNING. USED
THE TOPDOWN FOR PTYPE WITH NAM AS PRIMARY TEMPERATURE PROFILE
TONIGHT INTO TUESDAY.
HYDROLOGY SECTION CREATED TO HIGHLIGHT THE TRANSITION FROM A WINTER
EVENT TO POTENTIAL FOR HYDRO EVENT. THE VERY STRONG JET IN ADDITION
TO ADVECTING IN WARMER TEMPERATURES ALOFT WILL BRING PRECIPITABLE
WATER VALUES JUST ABOVE ONE INCH INTO THE FORECAST AREA. HIGHEST
LIQUID PRECIPITATION AMOUNTS WILL BE OVERNIGHT INTO TUESDAY MORNING
AIDED BY THE VERY STRONG LOW LEVEL JET. WILL CONTINUE HIGHLIGHT THE
STRONG WINDS AT HIGHER ELEVATIONS AND IN THE FAVORED DOWNSLOPE AREAS
FROM BLUEFIELD TO TAZEWELL WITHIN THE WINTER STORM WARNING. THE
COMBINATION OF SNOWMELT...CHALLENGING QPF FORECAST AND
PLACEMENT OF AXIS OF HEAVIER RAIN MAKE THE FLOOD POTENTIAL TRICKY.
WITH SNOW MELT...SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY
ON THE DAN AND LOWER ROANOKE. WILL ADD THE MENTION OF FLOOD
POTENTIAL TO THE HWO.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 245 PM EST MONDAY
ON THE HEEL`S OF MONDAY`S STORM WILL BE A CLIPPER THAT WILL DIVE
SOUTH ACROSS THE SOUTHERN OHIO-TENNESSEE VALLEYS TUESDAY EVENING.
TEMPERATURES SHOULD REMAIN WARM ENOUGH TO START OUT AS A LIGHT
RAIN...THEN TRANSITION TO UPSLOPE SNOW SHOWERS BY WEDNESDAY
MORNING. COMING QUICKLY BEHIND THE STRONGER SYSTEM...THIS CLIPPER
SHOULD NOT BRING ANY ADDITIONAL THREATS OF FLOODING NOR
SIGNIFICANT SNOWFALL. UPSLOPES SNOW SHOWERS DURING THE DAY
WEDNESDAY COULD BE WHITE RAIN AS TEMPERATURES WARM OR REMAIN IN
THE LOW TO MID 30S. MOUNTAIN TEMPERATURES MAY BE COLD ENOUGH ABOVE
3000 FT FOR SOME LIGHT SNOW ACCUMULATIONS...POSSIBLY UP TO 3
INCHES OVER A 36 HOUR PERIOD. 85H WINDS TURN QUICKLY OUT OF THE
WEST TO END PRECIPITATION CHANCES BY SUNRISE WEDNESDAY MORNING
ALONG AND EAST OF THE BLUE RIDGE BY SUNRISE WEDNESDAY MORNING.
WINDS WILL BE BREEZY AND GUSTY AT TIMES THROUGH THE PERIOD BUT ARE
NOT EXPECTED TO REACH ADVISORY CRITERIA. WE WILL HAVE MODERATE
PRESSURE RISES AND COLD AIR ADVECTION WHILE THE 85H CROSS-BARRIER
JET STAYS UNDER 30 KTS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 PM EST MONDAY
RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON
THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER
POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING
THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT
THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF
SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS
BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE
DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE
NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO
THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING
TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY
ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY
NIGHT THEN WARMER FRIDAY.
MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO
START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO
FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE
ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY
BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE
NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST.
WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST
OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER
WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO
60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY
WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER
IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS
MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO
PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS
MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN
TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS
NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER
POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE
NORMAL FOR DAY 7.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
AS OF 1251 PM EST MONDAY...
POOR FLYING CONDITIONS WILL CONTINUE DURING THE TAF PERIOD WITH A
WINTRY MIXTURE OF SNOW...SLEET...FREEZING RAIN AND RAIN ALONG WITH
WINDS AND LOW CLOUDS.
IFR/LIFR CONDITIONS WILL PREVAIL THIS AFTERNOON INTO TONIGHT.
WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO
RAIN OVERNIGHT. WARMER AIR OVERRIDING THE COLD AIR WILL INCREASE
TONIGHT AND SHOULD CHANGE MOST LOCATIONS TO PLAN RAIN TONIGHT.
SOME COLDER AIR MAY WORK INTO THE MTNS BY 12Z TUESDAY WITH
POSSIBLE LIGHT SNOW/FREEZING RAIN POSSIBLE AT KLWB.
ANOTHER ISSUE LATE TONIGHT WILL BE WINDS...AS MODELS SHOW A VERY
STRONG LOW LVL JET MOVING ACROSS THE CENTRAL APPALACHIANS. LOW LVL
WIND SHEAR MAY BE POSSIBLE OVER THE MOUNTAIN TERMINALS...SOME
GUSTS REACHING SFC AT KBLF WITH OVER 20 KTS POSSIBLE. MAY NEED TO
ADD LLWS TO TAFS LATER THIS EVENING OR TONIGHT. THE WINTER STORM
IS EXPECTED TO MOVE NORTHEAST AND AWAY FROM THE AREA TUESDAY. SOME
DRIER AIR WILL PUSH IN ON TUESDAY WITH SCATTERED RAIN AND SNOW
POCKETS POSSIBLE IN THE WEST.
LOW TO MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.
EXTENDED DISCUSSION...
A CLIPPER SYSTEM MAY IMPACT THE AREA TUESDAY NIGHT AND
WEDNESDAY...POSSIBLY RESULTING IN THE CONTINUATION OF POOR FLYING
CONDITIONS.
HIGH PRESSURE BUILDS IN THURSDAY WITH VFR RETURNING FOR THE
SECOND HALF OF THE WEEK.
&&
.HYDROLOGY...
AS OF 245 PM EST MONDAY
TRANSITION FROM A WINTER EVENT TO POTENTIAL FOR HYDRO EVENT
CONTINUES TO BE ONE OF THE ISSUES ON THE TABLE THIS AFTERNOON.
ACCUMULATING SNOW WINDING DOWN ACROSS THE CWA AS THE WARM NOSE
WORKS FURTHER NORTH. WIDESPREAD 5 TO 10 INCHES OF SNOW WAS
OBSERVED WITH THE EXCEPTION OF SOUTHEAST PIEDMONT COUNTIES WITH 2
TO 4 INCHES. WITH SNOW-LIQUID RATIOS RUNNING CLOSE TO 10:1 WE HAVE
A SOLID 0.50 TO 1 INCH OF SNOW WATER EQUIVALENT ON THE GROUND.
FREEZING RAIN AND SLEET WILL BE THE PREDOMINANT P-TYPE GOING
FORWARD BUT WITH A SIGNIFICANT WARMING TREND
OVERNIGHT...PRECIPITATION CHANGES TO ALL LIQUID FROM SOUTHWEST TO
NORTHEAST DURING THAT PERIOD. BASICALLY FOLLOWED WPC QPF NEXT 24
HOURS... WHICH IS RUNNING IN THE 1.00 TO 1.75 INCH RANGE CWA-WIDE
THROUGH TOMORROW EVENING WITH THE BULK CONCENTRATED IN THE 06-12Z
RANGE WITH UP TO AN INCH IN THAT 6-HOURS. NORMALLY THIS AMOUNT
WOULD BE SUFFICIENT FOR SOME FLOODING BOTH SHORT-FUSE (FLASH) AND
LONG-FUSE (RIVERS). BUT THE EXISTING SNOWPACK IS A BIG
COMPLICATING FACTOR. IT WILL ABSORB QUITE A BIT OF RAIN AND
DEPENDING ON THE EXACT TEMPERATURE/DEWPOINT REGIME IT COULD BE
THAT MOST IS ABSORBED...WITH ONLY LIMITED RUNOFF OVER THE NEXT
24-36 HOURS. HENCE...AFTER COORDINATING WITH SURROUNDING WFOS HAVE
OPTED TO NOT ISSUE ANY TYPE OF FLOOD WATCH FOR THE CWA. CAME
CLOSEST OVER THE NORTHEAST COUNTIES BUCKINGHAM/APPOMATTOX/AMHERST
WHERE THE COMBINATION OF FUTURE RAINFALL/SNOWMELT APPEARS TO BE
MAXIMIZED...ALTHOUGH FAR SOUTHWEST WAS ALSO CONSIDERED VULNERABLE
TO THE SAME COMBINATION ALTHOUGH IN DIFFERENT DOSAGES. ONCE IT ALL
MELTS SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY ON THE DAN
AND LOWER ROANOKE. VARIOUS ENSEMBLE RIVER FORECAST GUIDANCE SHOWS
UP TO A 70 PERCENT CHANCE OF MINOR FLOODING ON THE LOWER DAN AND
MORE LIKE 30 PERCENT ALONG PARTS OF THE JAMES RIVER WITHIN A FEW
DAYS. ALTHOUGH THE SIGNAL FOR WIDESPREAD FLOODING REMAINS
AMBIGUOUS...WILL HAVE TO WATCH CLOSELY EVOLVING QPF FORECASTS AND
THE OBSERVED AND MODELED RATE OF SNOWMELT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR VAZ007-009>020-
022>024-032>035-043>047-058-059.
NC...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ001>006-
018>020.
WV...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...KK
SHORT TERM...RCS
LONG TERM...JH/RCS
AVIATION...KK/WP
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST MON FEB 15 2016
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 322 PM CST MON FEB 15 2016
PRIMARY CONCERNS INVOLVE FOG AND SNOW CHANCES/AMOUNTS TONIGHT
THROUGH TUESDAY. 15.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT AND
WILL FOLLOW A BLENDED SOLUTION...ALTHOUGH FOCUS FOR THE NEXT 6 TO
12 HOURS WILL BE ON THE LATEST RAP/HRRR OUTPUT.
15.20Z WATER VAPOR LOOP SHOWS A WEAK SHORT-WAVE MOVING ACROSS
CENTRAL MN AND THIS HAS RESULTED IN A COMPACT AREA OF SNOW SHOWERS
NOW MOVING INTO SOUTHEAST MN. 15.20Z HRRR SHOWS THESE SHOWERS
MOVING EAST INTO THE EARLY EVENING AND THEN FALLING APART NEAR THE
MS RIVER. WITH SFC OBS UNDER THIS SNOW REPORTING VISIBILITY FROM 3
TO 5SM...A QUICK DUSTING IS POSSIBLE LATE THIS AFTERNOON/EARLY
EVENING.
BIGGER CONCERN THIS EVENING IS FOG POTENTIAL. WITH MOIST WARM AIR
ADVECTION REGIME OVER THE SNOWPACK AND RELATIVELY LIGHT NEAR
SURFACE FLOW...THINK THERE COULD BE A REPEAT FROM THIS MORNING
WITH RAPIDLY DEVELOPING FOG AFTER SUNSET. THIS IS ESPECIALLY TRUE
IF THE LIMITED CLEARING AREA ACROSS CENTRAL MN CAN WORK ITS WAY
INTO THE FORECAST AREA AND ALLOW FOR GREATER NOCTURNAL COOLING.
AREAS OF DENSE FOG A REAL POSSIBILITY...BUT TIMING/COVERAGE
UNCERTAIN AND SOMETHING TO WATCH THROUGHOUT THE EVENING FOR
POSSIBLE ADVISORY CONDITIONS. FOR NOW...WILL EXPAND PATCHY/AREAS
OF FOG FROM WEST TO EAST THIS EVENING AND OVERNIGHT. ANY FOG THAT
DOES DEVELOP IS NOT LIKELY TO DISSIPATE UNTIL SOMETIME TUESDAY
MORNING AT THE EARLIEST. TEMPERATURES TONIGHT WILL BE WARM...
GENERALLY IN THE UPPER TEENS TO MID 20S ABOVE ZERO.
15.12Z GLOBAL MODELS NOW IN GOOD AGREEMENT...SHOWING THE NEXT
SHORT-WAVE ALOFT FOR TONIGHT DIVING TO THE SOUTH AND WEST OF THE
FORECAST AREA. BEST 500 TO 300 HPA POSITIVE VORTICITY ADVECTION
AND MID-LEVEL FRONTOGENESIS WITH THIS WAVE IS BETTER ALIGNED
ALONG THE MO RIVER VALLEY WHERE A FEW INCHES OF SNOW ARE POSSIBLE.
A SECONDARY WEAKER SHORT-WAVE/SURFACE COLD FRONT WILL MOVE ACROSS
THE FORECAST AREA LATER TONIGHT THROUGH TUESDAY...BRINGING A
CHANCE FOR LIGHT SNOW ACROSS MUCH OF REGION. HOWEVER...LIFT AND
MOISTURE ARE RATHER UNIMPRESSIVE. NAM BUFKIT SOUNDINGS IN
PARTICULAR LACK ICE FOR MUCH OF THE PERIOD...WHEREAS THE GFS
SHOWS A DEEPER SATURATED LAYER. WILL NEED TO WATCH FOR POSSIBLE
FREEZING RAIN/DRIZZLE...BUT FOR NOW THINK THE NAM IS UNDER DOING
COLDER CLOUDS ALOFT AND WILL KEEP PRECIPITATION TYPE AS SNOW. IF
SNOW DOES DEVELOP WITHIN WEAK LIFT REGIME...ACCUMULATIONS WILL
GENERALLY BE AN INCH OR LESS REGION-WIDE.
TEMPERATURES TUESDAY WILL AGAIN HINGE ON CLOUD COVER...BUT SHOULD
RISE INTO THE LOWER 30S MOST AREAS PRIOR TO THE COLD FRONTAL
PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 PM CST MON FEB 15 2016
TUESDAY NIGHT THROUGH THURSDAY LOOK MAINLY DRY AS BROAD SURFACE
HIGH PRESSURE DOMINATES THE REGIONAL WEATHER PATTERN. A SLIGHTLY
COOLER AIR MASS ON WEDNESDAY IN THE WAKE OF TUESDAY/S COLD FRONT
WILL KEEP TEMPERATURES MAINLY IN THE 20S. HOWEVER...A MUCH DRIER
AIR MASS SHOULD LEND ITSELF TO SOME SUNSHINE FOR AT LEAST THE
LATTER HALF OF THE DAY. SIGNIFICANT WARM AIR ADVECTION ENSUES
AFTER 06Z THURSDAY SO THAT BY 06Z FRIDAY...925 HPA TEMPERATURES
RANGE FROM +3 TO +7 CELSIUS. ALTHOUGH DEPENDENT ON CLOUD COVER...
TEMPERATURES THURSDAY SHOULD CLIMB INTO THE MID TO UPPER 30S.
ATTENTION THEN TURNS TO THURSDAY NIGHT INTO FRIDAY AS THE NEXT
PACIFIC TROUGH LIFTS INTO THE UPPER MIDWEST. 15.12Z GFS/ECMWF ARE
IN BETTER AGREEMENT WITH THIS SYSTEM...ALTHOUGH THE GFS SURFACE
LOW TRACK IS A BIT FURTHER NORTH. THE GFS IS ALSO MORE BULLISH ON
QPF MAINLY THURSDAY NIGHT IN THE SYSTEM/S WARM SECTOR. STILL NEED
TO WATCH POTENTIAL FOR SOME MIXED FREEZING PRECIPITATION THURSDAY
NIGHT FOR AREAS NORTH OF I-94 THAT HAVE SUB-FREEZING SURFACE
TEMPERATURES. DEGREE OF WARMTH ON FRIDAY A BIT MORE UNCERTAIN NOW
AS BOTH MODELS ALIGN THE SURFACE COLD FRONT ALONG THE MS RIVER BY
12Z FRIDAY. HOWEVER...OVERALL POST-FRONTAL THERMAL PROFILE
REMAINS WARM ENOUGH SO THAT PRECIPITATION FALLS AS RAIN. FOR
NOW...EXPECT TEMPERATURES INTO THE 40S WITH CONSENSUS 30 TO 60
POPS.
A DRY AND WARM SATURDAY GIVES WAY TO ANOTHER SHOT OF PRECIPITATION
SUNDAY AS A SHORT-WAVE DROPS SOUTH FROM CANADA. TOO FAR OUT TO
PROVIDE MANY DETAILS...BUT PRECIPITATION TYPE SHOULD BE MAINLY
LIQUID. MONDAY DRIES OUT AND COOLS BACK DOWN ON THE BACKSIDE OF
DEPARTING WAVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY NOON)
ISSUED AT 1128 AM CST MON FEB 15 2016
WARMING AND MOISTENING SOUTHERLY FLOW WILL CONTINUE ACROSS THE AREA
THIS AFTERNOON INTO TUE MORNING. THIS AHEAD OF YET ANOTHER WEAK
NORTHWEST FLOW SYSTEM DROPPING ACROSS THE REGION. MVFR/IFR
CIGS/VSBYS IN BR/LOW STRATUS...MORE IFR AT SITES LIKE KRST AND MORE
MVFR AT VALLEY SITES LIKE KLSE...HAVE ALREADY SPREAD ACROSS THE
AREA. SOME MINOR IMPROVEMENTS THRU THIS AFTERNOON...BUT WITH
APPROACH OF ANOTHER LOW AND THE SOUTHERLY FLOW...CIGS/VSBYS EXPECTED
TO DROP TONIGHT AS MOISTURE IS CONTINUALLY PULLED NORTH OVER THE
COLD SNOW-COVERED GROUND. TRENDED KRST LIFR FOR MUCH OF THE 06Z-15Z
PERIOD AND KLSE TO IFR. CONDITIONS TO SLOWLY IMPROVE LATE TUE
MORNING AS THE LOW/TROUGH AXIS WOULD PASS AND PERHAPS SOME LIGHT
SNOW WOULD FALL TO HELP REDUCE/DISSIPATE THE FOG. EITHER WAY...MUCH
OF THE NEXT 24 HRS SHAPING UP TO BE AN IFR PERIOD AT BOTH TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION.....RRS