Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/17/16
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
840 PM MST TUE FEB 16 2016
.UPDATE...
ISSUED AT 840 PM MST TUE FEB 16 2016
WINDS HAVE BECOME LIGHT ACROSS THE PLAINS...AND ARE GRADUALLY
DECREASING ACROSS THE FOOTHILLS THIS EVENING. THIS TREND WILL
CONTINUE THROUGH THE REST OF THE NIGHT ALTHOUGH HIGHER MOUNTAIN
RIDGES WILL REMAIN GUSTY INTO WEDNESDAY MORNING. HIGH MOUNTAIN
VALLEYS HAVE SOME LOW LEVEL MOISTURE TRAPPED IN THEM...AND MOSTLY
CLEAR SKIES COULD ALLOW PATCHY FOG TO DEVELOP OVERNIGHT MAINLY IN
THE UPPER COLORADO RIVER BASIN. WEDNESDAYS FORECAST MAX TEMPS
COULD BE HELD DOWN A COUPLE DEGREES AS WAVE CLOUDS MAY BE MORE
PERSISTENT PER SYNTHETIC SATELLITE IMAGERY. NOT SURE HOW THICK
THEY WILL BE HOWEVER WITH WEAKENING CROSS MOUNTAIN FLOW...SO NO
CHANGES FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 340 PM MST TUE FEB 16 2016
STRONG NORTHWEST FLOW /120-130KT MAXIMA/ WAS ANGLING ACRS CNTRL
WY/EXTRM NERN CO AND WRN KS AT THIS TIME. CROSS SECTIONS ALSO SHOW
AMPLIFICATION OF A LEE SIDE MTN WAVE OVER THE NEXT FEW HOURS AND
THE PRESENCE OF A STRONG MTN TOP INVERSION...AS WELL AS
MODEST ENHANCEMENT OF THE SFC LEE TROUGH. DO NOT SEE WIND SPEEDS
REACHING HIGH WIND CRITERIA WITH THIS SETUP...THOUGH SPEEDS IN A
FEW AREAS PRONE TO HIGH WINDS SUCH AS ALONG THE DUMONT- GEORGETOWN
STRETCH OF I-70...UP AROUND BERTHOUD PASS...AND THE HIGHER
FOOTHILLS WEST OF BOULDER WHERE GUSTS HAVE BEEN OBSERVED IN THE
50-60 KT RANGE TODAY. AT THIS HOUR...WLY WINDS IN THE 30-45 KT IN
THE FRONT RANGE FOOTHILLS...AROUND 55 KTS ABOVE TIMBERLINE...AND
25-38 KTS ALONG THE BASE OF THE FOOTHILLS AND UP NEAR THE WYOMING
BORDER. TODAY`S RUNS OF THE NAM...WRF...HRRR AND RAP HAVE BEEN
HANDLING SPEEDS WELL...BUT THEY`VE NOT BEEN EXTENDING THESE GUSTY
CHINOOK WINDS FAR ENOUGH EAST ACROSS THE I-25 URBAN CORRIDOR. OVER
THE NEXT SEVERAL HOURS...WITH THE MTN WAVE RELAXING AND THE
STRONGER FLOW ALOFT LIFTING AND SHIFTING EAST OF THE CWA...SHOULD
SEE WIND SPEEDS LOWERING ON THE PLAINS DURING THE EARLY EVENING
HOURS...AND BY AROUND MIDNIGHT/07Z OVER HIGHER EAST SLOPES OF THE
FRONT RANGE. W-NWLY WINDS AROUND TIMBERLINE ARE LIKELY TO REMAIN
STRONG AND GUSTY ALL NIGHT. WILL INTRODUCE AREAS OF BLOWING SNOW
IN MTN AREAS WHERE GUSTS WILL LIKELY EXCEED 30 KTS. OTHERWISE
DIMINISHING WINDS ON THE PLAINS SOON AFTER SUNSET AND CLEAR/MOSTLY
CLEAR SKIES WILL ALLOW TEMPS TO FALL TO THE 20S AND LOWER 30S BY
MORNING. THESE TEMPS STILL 10-18 DEGS F ABOVE AVERAGE.
ON WEDNESDAY...LARGE UPPER RIDGE OUT WEST TONIGHT SHIFTS EAST OVER
THE ROCKY MTN REGION WITH THE 500 MB RIDGE AXIS SITTING OVER
CENTRAL COLORADO BY LATE IN THE DAY. MODERATE TO STRONG NORTHWEST
FLOW ALOFT TO START THE DAY WEAKENS AS IT BECOMES ZONAL. THIS IS
EXPECTED TO RESULT IN LIGHT SFC WINDS BOTH MTNS AND PLAINS.
HOWEVER STRONG PRESSURE FALLS UP IN THE DAKOTAS WILL PROMOTE THE
DEVELOPMENT OF GUSTY SLY GRADIENT WINDS OF 15-25 KTS ON THE ERN
PLAINS OF COLORADO DURING THE AFTERNOON HOURS. OTHERWISE A WARMER
DAY WITH HIGHS ON THE PLAINS GENERALLY 4-8 DEG F WARMER THAN
TODAY...AND 2-6 DEG F WARMER IN THE MTNS AND HIGH VALLEYS. KEEP IN
MIND...THESE TEMPERATURES ARE 14-20 DEG F ABOVE AVERAGE FOR THE
DATE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 340 PM MST TUE FEB 16 2016
UPPER LEVEL RIDGE WILL SHIFT EAST OF THE AREA WEDNESDAY NIGHT
WHILE A SHORT WAVE TROUGH MOVES ONTO THE CALIFORNIA COAST. THIS
WILL PRODUCE A STRONG WEST-SOUTHWEST FLOW ALOFT. AS THE TROUGH
NEARS COLORADO THURSDAY...A LEE SIDE SURFACE TROUGH WILL DEEPEN
ACROSS THE ROCKY MOUNTAIN REGION. THIS WILL CAUSE WINDS TO
INCREASE THROUGH THE DAY. THE DOWNSLOPE WINDS COMBINED WITH THE
WARM AIRMASS WILL PUSH HIGHS INTO THE UPPER 60S TO MID 70S. THE
RECORD FOR DENVER IS 71 AND THERE IS A GOOD CHANCE IT WILL BE
BROKEN. THE TROUGH WILL BRING SHOWERS TO THE MOUNTAINS THURSDAY
AFTERNOON AND EVENING. MOST OF THE PRECIPITATION WILL FALL AS
SNOW BECAUSE IT QUICKLY COOLS BEHIND THE PACIFIC COLD FRONT. AS
THE FRONT RACES EASTWARD...STRONG WINDS ARE EXPECTED TO SPREAD
ACROSS THE AREA DURING THE LATE AFTERNOON AND EVENING HOURS.
WINDS MAY APPROACH HIGH WIND CRITERIA AND WILL NEED TO BE
MONITORED.
AIRMASS QUICKLY DRIES BEHIND THE WAVE AND PRECIPITATION WILL END
BY MIDNIGHT THURSDAY NIGHT. HIGH PRESSURE WILL SETTLE OVER THE
AREA FRIDAY BRINGING LIGHTER WINDS. TEMPERATURES WILL BE COOLER
BUT WELL ABOVE AVERAGE STILL. ZONAL FLOW WILL PREVAIL FRIDAY AND
SATURDAY. THIS WILL KEEP DRY CONDITIONS OVER THE AREA. MILD
TEMPERATURES WILL CONTINUE INTO SATURDAY WITH READINGS CLIMBING
INTO THE 60S.
FOR SUNDAY AND EARLY NEXT WEEK...UPPER LEVEL RIDGE WILL INTENSIFY
OVER THE WESTERN U.S. FLOW ALOFT OVER COLORADO WILL TURN
NORTHWESTERLY. A COLD FRONT IS PROGGED TO PUSH THROUGH AND DROP
TEMPERATURES TO NEAR NORMAL. RIGHT NOW THE FLOW IS LOOKING DRY AND
THE ONLY MENTION OF PRECIPITATION WILL BE CONFINED TO THE
MOUNTAINS. THE COOLER TEMPERATURES ARE EXPECTED TO CONTINUE INTO
MONDAY. TUESDAY MAY BE WARMER IF THE RIDGE SHIFTS EASTWARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 840 PM MST TUE FEB 16 2016
VFR CONDITIONS WILL PERSIST WITH ONLY SCT-BKN CLOUDS ABOVE 20
THOUSAND FEET THROUGH WEDNESDAY NIGHT. WINDS ARE BECOMING LIGHT
AND VARIABLE AT KDEN AND KAPA AND WILL TRANSITION TO NORMAL
DRAINAGE THROUGH 06Z. KBJC MAY STILL SEE A FEW GUSTS TO 12-22
KNOTS OVERNIGHT. ON WEDNESDAY...LOW LEVEL FLOW WILL LIKELY TURN
MORE SOUTHEASTERLY AT KDEN AND KAPA...WITH GUSTS AROUND 20 KNOTS
POSSIBLE AFTER 20Z. KBJC WILL LIKELY SEE LIGHTER EAST-NORTH WINDS
PREVAIL WITH DENVER CYCLONE DEVELOPING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...MEIER
AVIATION...BARJENBRUCH
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
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 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
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
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
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
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 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...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
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
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
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 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 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
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 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 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 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 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 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 BISMARCK ND
923 PM CST TUE FEB 16 2016
.UPDATE...
ISSUED AT 920 PM CST TUE FEB 16 2016
WEB CAMS AND SURFACE OBSERVATIONS SHOW AREAS OF FOG HAVE FORMED
ACROSS THE SOUTHWEST INTO THE FAR NORTHWEST. WILL ADD FOG TONIGHT.
THE BAND OF SNOW CONTINUES ACROSS THE CENTRAL WHILE SLOWLY SHRINKING.
JUST NEED TO REFINE POPS A BIT FOR THIS. TRIMMED BACK THE AREA OF
FREEZING RAIN/DRIZZLE. DO NOT SEE MUCH AT THIS TIME BUT STILL
POSSIBLE LATER AS THE MID/HIGH LEVELS DRY OUT.
UPDATE ISSUED AT 603 PM CST TUE FEB 16 2016
FORECAST TRENDING WELL SO FAR. MIX OF RAIN AND SNOW CHANGING OVER
TO SNOW WEST AND MAINLY SNOW CENTRAL. GETTING A FAIRLY NARROW
AND FOCUSED BAND OF PRECIPITATION ON RADAR THAT ALIGNS WELL WITH
THE H850-H700 FRONTOGENESIS. WILL BE WATCHING FOR THE FORECAST
FREEZING DRIZZLE TO SHOW UP LATE THIS EVENING AFTER THE RAIN/SNOW
MOVES THROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
THE HIGHLIGHT IN THE SHORT TERM IS THE POTENTIAL FOR A WINTRY MIX
TONIGHT.
WE ARE CARRYING UP TO AROUND AN INCH OF SNOW IN THE FORECAST FROM
NORTHWEST INTO SOUTH CENTRAL NORTH DAKOTA THROUGH TONIGHT ROUGHLY
ALONG A LINE FROM WILLISTON TO BISMARCK AND ASHLEY. THAT IS BASED
ON A BLEND OF THE 12 UTC GLOBAL MODEL QPF GUIDANCE AND THE TIME-
LAGGED HIGH-RESOLUTION MODEL SUITE /INCLUDING THE RAP AND HRRR/.
RADAR ECHOES ARE INTENSIFYING SOUTHWEST OF THAT LINE AS OF 2145
UTC AS MID-LEVEL FRONTOGENESIS INCREASES...AND RECENT RAP OUTPUT
SUGGESTS THE FRONTOGENESIS BASED IN THE 850-700 MB LAYER WILL BE
MAXIMIZED OVER CENTRAL ND AROUND 01 UTC. GIVEN A QUICK BURST OF
MODERATE TO STRONG QG-FORCING TIED TO THE EXIT REGION OF A 110 KT
300-MB JET STREAK...THE AGEOSTROPHIC CIRCULATION WILL LIKELY BE
SUFFICIENTLY DEEP FOR A BRIEF PERIOD OF NOTEWORTHY PRECIPITATION
RATES. HOWEVER...RUN-TOTAL QPF FROM THE LAST FEW RUNS OF THE RAP
AND HRRR HAS BEEN TRENDING A BIT LOWER THAN ITS EARLIER FLAVORS
AND THE RESIDENCE TIME OF THE FORCING WILL BE SHORT IN ANY ONE
PLACE...WHICH IS WHY WE HAVE DOWNPLAYED THE OVERALL SNOW EVENT.
RELATIVELY WARM LOW- AND MID-LEVEL THERMAL PROFILES WILL LIKELY
PREVENT EFFICIENT SNOW GROWTH TOO...LIMITING THE SNOW-TO-LIQUID
RATIOS TO AROUND 11 TO 1. EVEN SO...GIVEN THE POTENTIAL FOR A
PERIOD OF STRONG FRONTOGENESIS...WE WILL HAVE TO MONITOR LATER
TRENDS IN CASE ADJUSTMENTS TO THE SNOWFALL FORECAST ARE NEEDED.
NOTE THAT MAXIMUM TEMPERATURES ALOFT SUGGEST A MIX OF RAIN AND
SNOW OR OUTRIGHT RAIN IN SOUTHWEST ND THROUGH THIS EVENING. THAT
IDEA IS BEING CARRIED IN THE FORECAST...BUT OBSERVATIONAL TRENDS
HAVE SUGGESTED WET BULB COOLING HAS BEEN FAVORING SNOW THUS FAR.
FINALLY...WE ARE STILL ADVERTISING A CHANCE OF LIGHT FREEZING
DRIZZLE TONIGHT ON THE BACK SIDE OF THE PRECIPITATION...AND ALL
THE WAY INTO WEDNESDAY MORNING IN CENTRAL ND. FORECAST SOUNDINGS
SHOW DRYING ALOFT AND A LINGERING STRATUS LAYER THAT IS MAINLY
WARMER THAN -10 C...SUPPORTING POTENTIAL SUPERCOOLED DROPS AND
THUS FREEZING DRIZZLE.
BY WEDNESDAY AFTERNOON...THE WEATHER WILL HAVE QUIETED DOWN WITH
THE AREA BETWEEN WAVES. STRATUS /LOW CLOUDS/ COULD HINDER WARMING
IF IT IS THICK ENOUGH...BUT THE 12 UTC MULTI-MODEL CONSENSUS THAT
WE USED TO BUILD THE FORECAST CALLS FOR HIGHS FROM THE LOWER 30S F
IN JAMESTOWN TO THE LOWER 50S F IN BOWMAN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
A PROGRESSIVE FLOW WITH A MEAN UPPER RIDGE IN THE WEST AND A TROUGH
IN THE EAST WILL RESULT IN SERIES OF SYSTEMS WITH MIXED
PRECIPITATION AND PERIODS OF WINDY CONDITIONS.
BEGINNING WEDNESDAY NIGHT INTO FRIDAY...BOTH THE NAM/GFS ARE
ADVERTISING AN H85 COLD POCKET TO WORK ACROSS CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. NAM/GFS BUFKIT SOUNDINGS
AGREE THAT ENOUGH OMEGA WITHIN THE SUPERCOOLED WATER DROPLET REGIME
COULD PRODUCE A LIGHT FREEZING RAIN POTENTIAL BEGINNING 09Z-12Z
THURSDAY NOON THURSDAY. HAVE ADDED A SLIGHT CHANCE FOR LIGHT
FREEZING RAIN INTO THE GRIDS ACROSS CENTRAL NORTH DAKOTA FROM 09Z-
18Z THURSDAY. WARM AIR ADVECTION WILL OVERSPREAD THE REGION THROUGH
00Z FRIDAY BEFORE A DOUBLE AREA OF SURFACE LOW PRESSURE AND
ASSOCIATED SHORTWAVE TROUGH ALOFT SHIFT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THURSDAY NIGHT INTO FRIDAY. A MIX OF RAIN/SNOW/LIGHT
FREEZING RAIN ALL POSSIBLE WITH THIS SYSTEM BASED UPON LOCATION AND
THERMODYNAMIC PROFILE. THE OTHER SIGNIFICANT WEATHER ELEMENT WILL BE
WIND LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. STRONGEST WINDS
ARE ADVERTISED FROM MID MORNING FRIDAY THROUGH MID AFTERNOON FRIDAY
WITH BOUNDARY LAYER WINDS OF BETWEEN 40KT AND 45KT ACROSS THE
SOUTHWEST...AND 30KT TO 35KT MOST ELSEWHERE. POTENTIAL HIGH WIND
WARNING SOUTHWEST WITH A SOLID WIND ADVISORY MOST OF WESTERN AND
CENTRAL NORTH DAKOTA DURING THIS TIME. THE TIME WINDOW OVERALL IS
BRIEF BUT WOULD STILL BE WORTHY OF THE ABOVE IF DATA REMAINS
CONSISTENT.
FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR
ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER
SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST
PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY
THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY
NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO
NORTHWEST WIND OF 20 TO 30 MPH.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE NEXT SHORTWAVE IS FORECAST
TO SHIFT ACROSS EASTERN MONTANA AND FAVOR SOUTHWEST NORTH DAKOTA
MONDAY AFTERNOON THROUGH MONDAY NIGHT WITH A SLIGHT CHANCE OF SNOW.
MILD HIGH TEMPERATURES THURSDAY AND FRIDAY WITH UPPER 50S SOUTHWEST
TO MID 40S CENTRAL AND MID 30S TURTLE MOUNTAINS. MILD AIR CONTINUES
INTO FRIDAY WITH GOOD MIXING ALOFT AND WIDESPREAD/MORE UNIFORM HIGHS
IN THE 40S TO LOWER 50S SOUTHWEST. A GRADUAL COOL DOWN SATURDAY
THROUGH TUESDAY...BUT REMAINING ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 603 PM CST TUE FEB 16 2016
AT 6 PM CST...A FRONTAL BOUNDARY EXTENDED ACROSS EASTERN MONTANA
SEPARATING MILD AIR TO THE WEST FROM COOLER AIR EAST. WEST WIND
FLOW OVER THE FRONTAL BOUNDARY WILL BE THE FOCUS FOR RAIN/SNOW
AND POSSIBLY FREEZING DRIZZLE ACROSS CENTRAL NORTH DAKOTA TUESDAY
EVENING. MVFR DETERIORATING TO IFR TONIGHT. CONDITIONS GRADUALLY
IMPROVING TO MVFR/VFR ON WEDNESDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 359 PM CST TUE FEB 16 2016
FLUCTUATING WATER LEVELS WILL CONTINUE ON THE MISSOURI RIVER
THROUGH BISMARCK AND MANDAN THROUGH MIDWEEK. SEE THE HYDROLOGIC
OUTLOOK ON OUR WEB PAGE FOR FULL DETAILS. THE LACK OF UPSTREAM
ICE AND WARMER TEMPERATURES WILL HELP TO LOWER THE RISK OF HIGHER
WATER OVER THE COMING DAYS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CJS
LONG TERM...KS
AVIATION...WAA
HYDROLOGY...CJS/AJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
614 PM CST TUE FEB 16 2016
.UPDATE...
ISSUED AT 603 PM CST TUE FEB 16 2016
FORECAST TRENDING WELL SO FAR. MIX OF RAIN AND SNOW CHANGING OVER
TO SNOW WEST AND MAINLY SNOW CENTRAL. GETTING A FAIRLY NARROW
AND FOCUSED BAND OF PRECIPITATION ON RADAR THAT ALIGNS WELL WITH
THE H850-H700 FRONTOGENESIS. WILL BE WATCHING FOR THE FORECAST
FREEZING DRIZZLE TO SHOW UP LATE THIS EVENING AFTER THE RAIN/SNOW
MOVES THROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
THE HIGHLIGHT IN THE SHORT TERM IS THE POTENTIAL FOR A WINTRY MIX
TONIGHT.
WE ARE CARRYING UP TO AROUND AN INCH OF SNOW IN THE FORECAST FROM
NORTHWEST INTO SOUTH CENTRAL NORTH DAKOTA THROUGH TONIGHT ROUGHLY
ALONG A LINE FROM WILLISTON TO BISMARCK AND ASHLEY. THAT IS BASED
ON A BLEND OF THE 12 UTC GLOBAL MODEL QPF GUIDANCE AND THE TIME-
LAGGED HIGH-RESOLUTION MODEL SUITE /INCLUDING THE RAP AND HRRR/.
RADAR ECHOES ARE INTENSIFYING SOUTHWEST OF THAT LINE AS OF 2145
UTC AS MID-LEVEL FRONTOGENESIS INCREASES...AND RECENT RAP OUTPUT
SUGGESTS THE FRONTOGENESIS BASED IN THE 850-700 MB LAYER WILL BE
MAXIMIZED OVER CENTRAL ND AROUND 01 UTC. GIVEN A QUICK BURST OF
MODERATE TO STRONG QG-FORCING TIED TO THE EXIT REGION OF A 110 KT
300-MB JET STREAK...THE AGEOSTROPHIC CIRCULATION WILL LIKELY BE
SUFFICIENTLY DEEP FOR A BRIEF PERIOD OF NOTEWORTHY PRECIPITATION
RATES. HOWEVER...RUN-TOTAL QPF FROM THE LAST FEW RUNS OF THE RAP
AND HRRR HAS BEEN TRENDING A BIT LOWER THAN ITS EARLIER FLAVORS
AND THE RESIDENCE TIME OF THE FORCING WILL BE SHORT IN ANY ONE
PLACE...WHICH IS WHY WE HAVE DOWNPLAYED THE OVERALL SNOW EVENT.
RELATIVELY WARM LOW- AND MID-LEVEL THERMAL PROFILES WILL LIKELY
PREVENT EFFICIENT SNOW GROWTH TOO...LIMITING THE SNOW-TO-LIQUID
RATIOS TO AROUND 11 TO 1. EVEN SO...GIVEN THE POTENTIAL FOR A
PERIOD OF STRONG FRONTOGENESIS...WE WILL HAVE TO MONITOR LATER
TRENDS IN CASE ADJUSTMENTS TO THE SNOWFALL FORECAST ARE NEEDED.
NOTE THAT MAXIMUM TEMPERATURES ALOFT SUGGEST A MIX OF RAIN AND
SNOW OR OUTRIGHT RAIN IN SOUTHWEST ND THROUGH THIS EVENING. THAT
IDEA IS BEING CARRIED IN THE FORECAST...BUT OBSERVATIONAL TRENDS
HAVE SUGGESTED WET BULB COOLING HAS BEEN FAVORING SNOW THUS FAR.
FINALLY...WE ARE STILL ADVERTISING A CHANCE OF LIGHT FREEZING
DRIZZLE TONIGHT ON THE BACK SIDE OF THE PRECIPITATION...AND ALL
THE WAY INTO WEDNESDAY MORNING IN CENTRAL ND. FORECAST SOUNDINGS
SHOW DRYING ALOFT AND A LINGERING STRATUS LAYER THAT IS MAINLY
WARMER THAN -10 C...SUPPORTING POTENTIAL SUPERCOOLED DROPS AND
THUS FREEZING DRIZZLE.
BY WEDNESDAY AFTERNOON...THE WEATHER WILL HAVE QUIETED DOWN WITH
THE AREA BETWEEN WAVES. STRATUS /LOW CLOUDS/ COULD HINDER WARMING
IF IT IS THICK ENOUGH...BUT THE 12 UTC MULTI-MODEL CONSENSUS THAT
WE USED TO BUILD THE FORECAST CALLS FOR HIGHS FROM THE LOWER 30S F
IN JAMESTOWN TO THE LOWER 50S F IN BOWMAN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
A PROGRESSIVE FLOW WITH A MEAN UPPER RIDGE IN THE WEST AND A TROUGH
IN THE EAST WILL RESULT IN SERIES OF SYSTEMS WITH MIXED
PRECIPITATION AND PERIODS OF WINDY CONDITIONS.
BEGINNING WEDNESDAY NIGHT INTO FRIDAY...BOTH THE NAM/GFS ARE
ADVERTISING AN H85 COLD POCKET TO WORK ACROSS CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. NAM/GFS BUFKIT SOUNDINGS
AGREE THAT ENOUGH OMEGA WITHIN THE SUPERCOOLED WATER DROPLET REGIME
COULD PRODUCE A LIGHT FREEZING RAIN POTENTIAL BEGINNING 09Z-12Z
THURSDAY NOON THURSDAY. HAVE ADDED A SLIGHT CHANCE FOR LIGHT
FREEZING RAIN INTO THE GRIDS ACROSS CENTRAL NORTH DAKOTA FROM 09Z-
18Z THURSDAY. WARM AIR ADVECTION WILL OVERSPREAD THE REGION THROUGH
00Z FRIDAY BEFORE A DOUBLE AREA OF SURFACE LOW PRESSURE AND
ASSOCIATED SHORTWAVE TROUGH ALOFT SHIFT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THURSDAY NIGHT INTO FRIDAY. A MIX OF RAIN/SNOW/LIGHT
FREEZING RAIN ALL POSSIBLE WITH THIS SYSTEM BASED UPON LOCATION AND
THERMODYNAMIC PROFILE. THE OTHER SIGNIFICANT WEATHER ELEMENT WILL BE
WIND LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. STRONGEST WINDS
ARE ADVERTISED FROM MID MORNING FRIDAY THROUGH MID AFTERNOON FRIDAY
WITH BOUNDARY LAYER WINDS OF BETWEEN 40KT AND 45KT ACROSS THE
SOUTHWEST...AND 30KT TO 35KT MOST ELSEWHERE. POTENTIAL HIGH WIND
WARNING SOUTHWEST WITH A SOLID WIND ADVISORY MOST OF WESTERN AND
CENTRAL NORTH DAKOTA DURING THIS TIME. THE TIME WINDOW OVERALL IS
BRIEF BUT WOULD STILL BE WORTHY OF THE ABOVE IF DATA REMAINS
CONSISTENT.
FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR
ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER
SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST
PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY
THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY
NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO
NORTHWEST WIND OF 20 TO 30 MPH.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE NEXT SHORTWAVE IS FORECAST
TO SHIFT ACROSS EASTERN MONTANA AND FAVOR SOUTHWEST NORTH DAKOTA
MONDAY AFTERNOON THROUGH MONDAY NIGHT WITH A SLIGHT CHANCE OF SNOW.
MILD HIGH TEMPERATURES THURSDAY AND FRIDAY WITH UPPER 50S SOUTHWEST
TO MID 40S CENTRAL AND MID 30S TURTLE MOUNTAINS. MILD AIR CONTINUES
INTO FRIDAY WITH GOOD MIXING ALOFT AND WIDESPREAD/MORE UNIFORM HIGHS
IN THE 40S TO LOWER 50S SOUTHWEST. A GRADUAL COOL DOWN SATURDAY
THROUGH TUESDAY...BUT REMAINING ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 603 PM CST TUE FEB 16 2016
AT 6 PM CST...A FRONTAL BOUNDARY EXTENDED ACROSS EASTERN MONTANA
SEPARATING MILD AIR TO THE WEST FROM COOLER AIR EAST. WEST WIND
FLOW OVER THE FRONTAL BOUNDARY WILL BE THE FOCUS FOR RAIN/SNOW
AND POSSIBLY FREEZING DRIZZLE ACROSS CENTRAL NORTH DAKOTA TUESDAY
EVENING. MVFR DETERIORATING TO IFR TONIGHT. CONDITIONS GRADUALLY
IMPROVING TO MVFR/VFR ON WEDNESDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 359 PM CST TUE FEB 16 2016
FLUCTUATING WATER LEVELS WILL CONTINUE ON THE MISSOURI RIVER
THROUGH BISMARCK AND MANDAN THROUGH MIDWEEK. SEE THE HYDROLOGIC
OUTLOOK ON OUR WEB PAGE FOR FULL DETAILS. THE LACK OF UPSTREAM
ICE AND WARMER TEMPERATURES WILL HELP TO LOWER THE RISK OF HIGHER
WATER OVER THE COMING DAYS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CJS
LONG TERM...KS
AVIATION...WAA
HYDROLOGY...CJS/AJS
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 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 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 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
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.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1224 PM CST MON FEB 15 2016
.AVIATION...
WITH THE COLD FRONT CONTINUING TO MAKE ITS WAY ACROSS SE TX THIS
AFTN WE SHOULD BE SEEING THE END OF THE PCPN/CLOUDS FROM THE NW.
NO REAL CHANGES WITH FROPA TIMING WITH THE 18Z TAF PACKAGE...NOR
WITH THE FCST OF ONSHORE WINDS RETURNING AREAWIDE TOMORROW MORN.
WE COULD SEE VERY PATCHY FOG OVERNIGHT AT AIRPORTS CLOSER TO THE
COAST...OTHERWISE THIS WILL MAINLY BE A VFR FCST. 41
&&
.PREV DISCUSSION... /ISSUED 1027 AM CST MON FEB 15 2016/
MORNING FORECAST UPDATE...OVERALL FORECAST ON TRACK WITH MAINLY
SHOWERS ACROSS SE TX. BULK OF THE ACTIVITY HAS BEEN CONFINED TO
HOUSTON SOUTHWARD ALONG THE COAST. MOST SHOWER ACTIVITY STRETCHES
FROM BAY CITY TO BEAUMONT. THERE MAY BE A FEW EMBEDDED
THUNDERSTORMS BUT MOST OF THE THUNDERSTORM ACTIVITY HAS PUSHED
EAST INTO LOUISIANA. SFC ANALYSIS AT 16Z HAS COLD FRONT ON THE
DOOR STEP OF CROCKETT TO CALDWELL. EXPECT FRONT TO PUSH THROUGH
WITH NOT MUCH SHOWER OR THUNDERSTORM ACTIVITY. UPDATED FORECAST ON
LATEST RADAR TRENDS AND LATEST HRRR SHORT RANGE DATA THAT SEEMS TO
BE DOING OKAY WITH EVOLUTION. IT HAS BEEN OVER DOING SHOWER
ACTIVITY FOR TODAY.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 47 77 49 76 / 10 0 0 0 0
HOUSTON (IAH) 76 50 77 49 75 / 20 0 0 0 0
GALVESTON (GLS) 70 56 71 56 68 / 30 10 0 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
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...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
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
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 SEATTLE WA
315 PM PST TUE FEB 16 2016
.SYNOPSIS...A WEAK WARM FRONT OVER THE COASTAL WATERS WILL LIFT
NORTHEAST ACROSS THE AREA TONIGHT. A LARGE UPPER LEVEL TROUGH WILL
DEVELOP OFF THE COAST ON WEDNESDAY THEN MOVE THROUGH THE AREA ON
THURSDAY. FRONTS WILL MOVE ACROSS THE AREA ON FRIDAY AND ON
SUNDAY. DRY WEATHER IS POSSIBLE EARLY NEXT WEEK.
&&
.SHORT TERM...A WARM FRONT OVER THE COASTAL WATERS WILL MOVE
NORTHEAST ACROSS THE AREA TONIGHT. KLGX RADAR IS FINALLY STARTING TO
SHOW AN INCREASE IN RAINFALL OFFSHORE THAT IS MOVING TOWARD THE
NORTHEAST. WHILE THE HRRR HAS BACKED OFF BY 2-3 HOURS ON THE
MOVEMENT OF THE PRECIPITATION INLAND...IT CONTINUES TO SHOW
PRECIPITATION MOVING INTO THE PUGET SOUND LOWLANDS SHORTLY AFTER
SUNSET WITH ABOUT A 6 HOUR PERIOD OF LIGHT RAIN. THE FRONT AND
ITS RAIN WILL MOVE INTO CANADA LATE TONIGHT.
A 993 MB LOW NOW NEAR 45N 141W IS FORECAST TO DEEPEN TO 977 MB WED
EVENING AS IT MOVES TO 48N 141W. THE COLD FRONT ASSOCIATED WITH THIS
LOW IS EXPECTED TO MOVE ONSHORE LATE WED AFTERNOON BRINGING A PERIOD
OF SHOWERS AND BREEZY CONDITIONS.
THE PROBLEM CONTINUES TO BE WHAT WILL HAPPEN TO THE LOW THU AS IT
WOBBLES INLAND. THE 18Z GFS ONLY WEAKENS THE LOW TO 984 MB AS IT
SLAMS THE LOW ONTO THE NORTH WASHINGTON COAST AROUND FORKS WITH A
NICE TIGHT PRES GRADIENT TO ITS SOUTH. THE 12Z GFS SHOWED ONLY A
WEAK TRIPLE POINT FEATURE ALONG AN OCCLUSION WITH THE MAIN LOW MOVING
INTO QUEEN CHARLOTTE SOUND. THE 18Z NAM12 SLAMS A 989 MB LOW INTO
THE MOUTH OF THE COLUMBIA RIVER. THE 12Z ECMWF WAS CLOSER TO THE 12Z
GFS20 THAT WAS FOLLOWED. CONFIDENCE IN THE FORECAST...ESPECIALLY
WIND ON THE CENTRAL COAST AND IN THE PUGET SOUND LOWLANDS AND
CONCERNING WAVES AND HIGH SURF ON THE CENTRAL WASHINGTON COAST IS
LOW.
IN THE MOUNTAINS...SNOW LEVELS WILL LIKELY FALL TO AROUND 3500
FEET OR SO WEDNESDAY EVENING. FLOW ALOFT WILL BECOME SOUTH TO
SOUTHWESTERLY AND THE SHOWERY NATURE OF THE PRECIPITATION WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT WILL LIKELY KEEP SNOWFALL AMOUNTS IN THE
MOUNTAINS BELOW THE NEED FOR A WINTER WEATHER ADVISORY.
THE GFS20 AND ECMWF BOTH SHOW A VIGOROUS BUT PROGRESSIVE FRONTAL
SYSTEM MOVING INLAND ON FRIDAY GIVING ANOTHER ROUND OF RAIN AND
WINDY CONDITIONS. ALBRECHT
.LONG TERM...MODELS ARE IN REASONABLY GOOD AGREEMENT THAT SATURDAY
WILL BE CLOUDY BUT NOT OVERLY WET AS A WEAK RIDGE MOVES EAST ACROSS
THE AREA. ANOTHER RATHER VIGOROUS FRONT WILL MOVE ACROSS THE AREA
SUNDAY OR SUNDAY NIGHT GIVING RAIN AND BREEZY CONDITIONS.
RECENT RUNS OF BOTH THE ECMWF AND GFS SHOW A STRONG RIDGE AND LOW
LEVEL OFFSHORE FLOW FOR MONDAY AND POSSIBLY TUESDAY OF NEXT WEEK.
CONDITIONS SHOULD BE DRY AND THERE IS A CHANCE THAT WE MAY BE ABLE
TO HIT TEMPERATURES IN THE LOWER 60S ALONG THE WEST SLOPES OF THE
CASCADES AND ON THE COAST IF WE ARE LUCKY. ALBRECHT
&&
.AVIATION...THE WEAK WARM FRONT MIGHT NOT AMOUNT TO MUCH THIS
EVENING...BUT CLOUDS SHOULD INCREASE WITH A LITTLE LIGHT RAIN
TONIGHT. OFFSHORE FLOW WILL INCREASE TONIGHT AND WED SO THERE SHOULD
BE DRYING AND IMPROVING CONDITIONS INTO THE MIDDAY AND PART OF THE
AFTERNOON ON WED...THEN ANOTHER FRONT ARRIVES LATE WED AFTERNOON
AND EVENING.
KSEA...A WEAK WARM FRONT WILL BRUSH THE AREA TONIGHT FOR A LITTLE
LIGHT RAIN...BUT THE NEXT SIGNIFICANT FRONT SHOULD HOLD OFF TIL WED
EVENING.
&&
.MARINE...A WEAK FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON
EVENING. A VIGOROUS LOW PRESSURE SYSTEM WILL AFFECT THE AREA LATER
WED THROUGH FRI AND THE LOW WILL KICK OUT AT LEAST A COUPLE OF
STRONG FRONTS.
&&
.HYDROLOGY...A FEW RIVERS REMAIN ABOVE FLOOD STAGE THIS
AFTERNOON...BUT THEY WILL SLOWLY RECEDE OVER THE NEXT 24 HOURS.
CONDITIONS WILL BE RATHER WET ACROSS THE AREA THROUGH
SUNDAY. BUT PRECIPITATION TONIGHT WILL BE LIGHT...IT WILL BE SHOWERY
IN NATURE WITH WINDS MORE SOUTHERLY ALOFT AND SNOW LEVELS 3500 FEET
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...AND FRONTS MOVING THROUGH
THE AREA FRIDAY AND AGAIN ON SUNDAY WILL BE PROGRESSIVE IN NATURE.
THIS MEANS THAT RIVERS WILL SEE SOME BRIEF RISES -MAINLY FRIDAY OR
FRIDAY NIGHT AND AGAIN LATER ON SUNDAY. HOWEVER...RENEWED FLOODING
IS NOT EXPECTED FOR THE NEXT 7 DAYS. ALBRECHT
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...FLOOD WARNINGS ARE IN EFFECT FOR PORTIONS OF THE AREA. SEE
THE LATEST FLOOD BULLETIN FOR DETAILS.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM PST WEDNESDAY
FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT
10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL 6 AM PST WEDNESDAY FOR
GRAYS HARBOR BAR.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
908 PM CST TUE FEB 16 2016
.UPDATE...
LOW CLOUD DECK ERODING IN SUBSIDENCE BEHIND DEPARTING SHORT WAVE
TROUGH A BIT FASTER THAN EARLIER EXPECTED...WHICH THE NEW NAM
LAYER RH FORECASTS ARE HANDLING WELL. HAVE DROPPED LOW
TEMPERATURES ONLY A FEW DEGREES FROM PREVIOUS FORECAST AS ENOUGH
GRADIENT WINDS EXPECTED OVERNIGHT TO KEEP BOUNDARY LAYER SOMEWHAT
MIXED AND LOWEST DEW POINTS UPSTREAM LOOK TO STAY NORTH AND
NORTHEAST OF FORECAST AREA. STILL EXPECT DEW POINTS IN THE +10F TO
+15F RANGE IN THE SOUTHERN HALF OF THE CWA WITH +4F TO +8F IN THE
NORTH...AND LOWS COULD TANK TO THOSE LEVELS IF WINDS COMPLETELY
DECOUPLE.
&&
.AVIATION/06Z TAFS/...
AREA OF CLEARING WITHIN SUBSIDENT REGIME OVER NORTHWEST WISCONSIN AND
MINNESOTA IS ADVANCING STEADILY TOWARDS SOUTHERN WISCONSIN. AT LEAST
PARTIAL CLEARING IS EXPECTED FOR MOST AREAS BY AROUND MIDNIGHT AT THE
LATEST. ALREADY SEEING SOME CLOUD EROSION NORTHWEST OF MADISON WHERE
CIGS WERE RISING TO AROUND 2.5 TO 3 KFT. AS SUCH...WILL TREND A BIT
MORE OPTIMISTIC WITH SKY COVER IN THE SHORT TERM FOR THE 03Z TAF
UPDATES. WILL HAVE TO KEEP AN EYE AREA OF LOW CLOUDS CURRENTLY OVER
NORTHEAST WISCONSIN...BUT PARCEL TRAJECTORIES SUGGEST THEY SHOULD
STAY NORTH OF THE TAF SITES TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 244 PM CST TUE FEB 16 2016/
TONIGHT AND WEDNESDAY...FORECAST CONFIDENCE IS HIGH
THE LAST OF A BAND OF LIGHT SNOW SHOWERS WILL MOVE OUT OF THE
FORECAST AREA THIS EVENING AS A CLIPPER SYSTEM TRANSLATES
THROUGH THE MISSISSIPPI RIVER VALLEY DOWN OVER THE SOUTHEASTERN
UNITED STATES. NO ACCUMULATIONS ARE EXPECTED WITH THE REMAINING SNOW
SHOWERS AS RAP AND NAM BUFKIT SOUNDINGS INDICATE DRYING WITHIN THE
DENDRITIC SNOW GROWTH ZONE. AS THE LAST OF THE SNOW MOVES
OUT...WINDS WILL VEER TO A MORE NORTHWESTERLY DIRECTION
OVERNIGHT...WHICH SHOULD HELP ENHANCE COLD AIR ADVECTION...REDUCING
TEMPERATURES. MODEL 925 MB TEMPERATURES LOOK TO BE GENERALLY
BETWEEN -12 AND -7C...TAKING THE ECMWF...NAM...AND GFS MODELS INTO
ACCOUNT. OVERNIGHT LOWS SHOULD RANGE FROM THE MID TO UPPER TEENS.
CLOUDS LOOK TO SLOWLY DETERIORATE OVERNIGHT AS A DRIER AIR MASS
SLOWLY MOVES IN FROM THE NORTH AFTER MIDNIGHT. SFC HIGH PRESSURE
MOVING SOUTHEAST FROM MANITOBA WILL TRANSLATE OVER OUR
REGION...KEEPING CONDITIONS QUIET FOR WEDNESDAY. EXPECTING PARTLY TO
MOSTLY SUNNY SKIES DURING THE DAY WEDNESDAY...BUT HIGH TEMPERATURES
WILL BE COOLER THAN THEY WERE TUESDAY AS HIGHS REACH INTO THE MID TO
UPPER 20S.
WEDNESDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE WILL CONTINUE TO SLIDE OFF TO THE EAST. SOUTHERLY
WINDS WILL BE INCREASING...BUT GENERALLY ABOVE A DECOUPLED
BOUNDARY LAYER DURING THE OVERNIGHT HOURS. THE LOW TEMP WILL
LIKELY OCCUR RIGHT AFTER SUNSET...THEN SLOWLY RISE AS ELEVATED
WARM ADVECTION ARRIVES. DESPITE THE WAA...MOISTURE IS LIMITED...SO
STILL DRY.
THURSDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
A STRONG MID LEVEL SHORT WAVE WILL BEGIN TO KICK OUT OF THE NRN
ROCKIES AND INTO THE WESTERN DAKOTAS BY LATE THU AFTERNOON. SFC
CYCLOGENESIS WILL BEGIN ON THU OVR THE NRN HIGH PLAINS. THE
INCREASING SOUTHERLY WINDS WILL BRING SUSTAINED AND VERY DEEP WARM
AIR ADVECTION TO HIT WRN WI THU AFTN...THEN CONTINUES INTO EARLY
FRIDAY MORNING. THERE/S A SMALL CHANCE OF LIGHT RAIN ACROSS THE
WEST LATE THURSDAY AFTERNOON. BUT PRECIP CHANCES INCREASE AND
SPREAD ACROSS THE REST OF SRN WISCONSIN OVERNIGHT INTO FRIDAY.
THE BEST CHANCE WILL BE FOCUSED NORTH OF MILWAUKEE AND MADISON.
TEMPS WILL STAY WARM ENOUGH TO KEEP IT ALL RAIN.
THE TRACK OF THE SFC LOW HAS STRONG CONSENSUS AMONG THE
MODELS...MOVING ACROSS THE U.P. OF MICHIGAN ON FRIDAY. THIS PUTS
US SOLIDLY IN THE WARM SECTOR. THE SYSTEM WILL BE OCCLUDED...BUT
IT/S POSSIBLE THE SFC WARM FRONT WILL GET JUST NORTH OF THE WI/IL
STATE LINE BETWEEN 6-10AM FRI MORNING. IT STILL LOOKS LIKE WE WILL
BE ABLE TO HIT THE LOWER AND POSSIBLY MID 50S FROM KJVL TO KENW.
THE SFC TROUGH/COLD FRONT STRETCHING SOUTH FROM THE LOW WILL
LIKELY MOVE ACROSS THE AREA BY MID DAY. THIS WILL BE FOLLOWED BY A
SHOT COLD AIR ADVECTION THAT WILL LIKELY ONLY LOWER TEMPS A BIT
DURING THE AFTERNOON. IF WE GET SOME CLEARING IN THE DRY SLOT
BEHIND THE FRONT...WE MAY EVEN SEE TEMPS RISE A BIT.
FRIDAY NIGHT THRU SATURDAY NIGHT...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE BUILDS IN QUICKLY IN THE WAKE OF THE DEPARTING LOW.
WE DON/T SEE STRONG COLD ADVECTION BEHIND THE LOW...SO SATURDAY
IS SHAPING UP TO BE QUITE MILD AGAIN WITH HIGHS HITTING THE MID
AND UPPER 40S. IF WE CAN GET MORE SUNSHINE...IT/S POSSIBLE WE
COULD SEE SOME LOW 50S ACROSS THE SOUTH AGAIN. DRY THIS PERIOD.
SUNDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
A VERY WEAK TROUGH DROPPING SOUTHEAST THROUGH THE GREAT LAKES
WILL BRING US A SMALL CHANCE OF LIGHT PRECIP THROUGH THIS PERIOD.
NOT MUCH IMPACT FOR SURE. TEMPS WILL BEGIN TO SINK CLOSER TO
SEASONAL LEVELS ONCE THIS MOVES THROUGH BY MONDAY INTO TUESDAY.
AVIATION/00Z TAFS/...
MAINLY MVFR CONDITIONS...WITH THE POTENTIAL FOR IFR CIGS AND
VSBYS...TO CONTINUE FOR THE REST OF THE AFTERNOON AS SOME FLURRIES/-
SN CONTINUES TO MOVE THROUGH S WI. VSBYS WILL IMPROVE ONCE THE LIGHT
SNOW MOVES OUT...WHICH SHOULD BE BETWEEN 6 AND 9 PM CST TONIGHT. ANY
SNOW THAT FALLS WILL BE MORE OF THE DRY TYPE WITH SNOW-TO-LIQUID
RATIOS OF 16:1 THIS EVENING AND OVERNIGHT. MODEL SOUNDINGS INDICATE
LOW LEVEL LAPSE RATES WILL REMAIN STEEP OVERNIGHT...WHICH SHOULD KEEP
LOW CIGS IN THE AREA...WITH CIG HEIGHTS BETWEEN 1-3 KFT POSSIBLE.
NORTHWESTERLY WINDS WILL SLOWLY VEER TO A MORE NORTHERLY DIRECTION BY
WEDNESDAY MORNING...WITH MORE NORTHEAST TO EASTERLY WINDS POSSIBLE
DURING THE DAY WEDNESDAY AS AN AREA OF HIGH PRESSURE MOVES IN FROM
CANADA.
EXPECT VFR SKY CONDITIONS DURING THE DAY WEDNESDAY AS SKIES WILL
CHANGE FROM OVC/BKN CATEGORIES OVERNIGHT TO SCT/FEW AS A DRIER AIR
MASS ASSOCIATED WITH THE SFC HIGH PRESSURE MOVES IN.
MARINE...
GUSTY WINDS AND HIGH WAVES ARE POSSIBLE THURSDAY INTO FRIDAY NIGHT
ACROSS THE NEARSHORE WATERS OF LAKE MICHIGAN...AS LOW PRESSURE
PASSES BY TO THE NORTHWEST OF THE AREA. GUSTS COULD BE BETWEEN 25-
30 KTS THURSDAY AFTERNOON AND EVENING. A TIGHT PRESSURE GRADIENT IS
EXPECTED DURING THIS TIME...WHICH SHOULD BRING THESE GUSTY WINDS AND
BUILDING WAVES. A SMALL CRAFT ADVISORY MAY BE NEEDED FOR THIS PERIOD
IN LATER FORECASTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM/SPM
TONIGHT/WEDNESDAY AND AVIATION/MARINE...JTS
WEDNESDAY NIGHT THROUGH TUESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
510 PM CST TUE FEB 16 2016
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 338 PM CST TUE FEB 16 2016
FORECAST CHALLENGES INCLUDE CLOUD TRENDS/TEMPERATURES AND POSSIBLE
FOG TONIGHT INTO WEDNESDAY. WILL FOCUS ON THE LATEST HIGH
RESOLUTION MODEL OUTPUT TO RESOLVE THESE ISSUES. THEREAFTER...
16.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT AND WILL FOLLOW A
BLENDED SOLUTION.
16.21Z ANALYSIS SHOWS A SURFACE COLD FRONT FROM CENTRAL WI TO
ALONG THE IA/IL BORDER. AS A RESULT...SCATTERED SNOW SHOWERS FROM
EARLIER TODAY HAVE ALSO MOVED INTO CENTRAL/EASTERN WI AND
NORTHERN IL WITH DRY CONDITIONS IN ITS WAKE. A STRONG 1024 HPA
SURFACE HIGH ACROSS MANITOBA IS FORECAST TO DROP SOUTH ACROSS THE
UPPER MS RIVER VALLEY BY 12Z WEDNESDAY. A DRIER AIR MASS WILL
ACCOMPANY THIS HIGH...ESPECIALLY ABOVE 900 HPA. CURRENT CLEAR AREA
ACROSS NORTH-CENTRAL MN WILL MOVE SOUTH WITH THIS HIGH...RESULTING
IN AT LEAST PARTIAL CLEARING THIS EVENING AND OVERNIGHT ESPECIALLY
EAST OF THE MS RIVER. AS A RESULT OF THIS CLEARING...DROPPED
TEMPERATURES TONIGHT INTO THE SINGLE DIGITS TO TEENS ABOVE ZERO.
HOWEVER...CLEARING SKIES AND DIMINISHING WINDS ALSO INCREASE THE
THREAT FOR FOG DEVELOPMENT. CURRENTLY THINKING SOME PATCHY FOG IS
POSSIBLE MAINLY ALONG AND SOUTH OF THE MN/IA BORDER AFTER MIDNIGHT
IN AREAS OF HIGHER SATURATION...BUT DRIER AIR MASS WITH UPSTREAM
DEW POINTS IN THE SINGLE DIGITS SHOULD LIMIT WIDESPREAD FOG. THIS
IDEA IS SUPPORTED BY THE LATEST HOURLY HIGH RESOLUTION DATA SETS.
LOW-LEVEL CLOUDS/LIGHT SNOW ALONG WESTERN FLANK OF THE SURFACE
HIGH COINCIDENT WITH STRONG LOW-LEVEL WARM AIR ADVECTION AND
ISENTROPIC LIFT ON THE 285 TO 290K SURFACES WILL STAY MAINLY SOUTH
AND WEST OF THE FORECAST AREA...ALTHOUGH COULD SEE SOME CLOUDS
LINGER LONGER ACROSS PORTIONS OF NORTHEAST IA AND SOUTHEAST MN.
WEDNESDAY WILL BE DRY WITH AT LEAST PARTIAL SUNSHINE AS SURFACE
HIGH PRESSURE SLOWLY DRIFTS INTO THE LOWER GREAT LAKES REGION.
DESPITE INCREASED SUNSHINE...TEMPERATURES WILL BE A BIT COOLER
THAN TODAY WITH HIGHS MAINLY IN THE 20S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE FEB 16 2016
STRONG SFC TO 500 HPA WARM AIR ADVECTION IS THE RULE WEDNESDAY
NIGHT THROUGH AT LEAST EARLY FRIDAY. 16.12Z GFS/NAM NOW SHOWING
SOME LIGHT QPF DEVELOPING ACROSS PORTIONS OF THE FORECAST AREA
THURSDAY AFTERNOON...SO ADDED 20 POPS AS PRIMARY 850 TO 700 HPA
WARM FRONT LIFTS NORTHEAST. SURFACE TEMPERATURES MAY LAG A BIT
WITH SUB-FREEZING VALUES ALONG AND NORTHEAST OF THE MS RIVER...
RESULTING IN THE CHANCE FOR SOME MIXED FREEZING PRECIP OR FREEZING
RAIN THROUGH THURSDAY EVENING. BY THURSDAY NIGHT...THE ENTIRE
COLUMN WARMS ENOUGH FOR REMAINING PRECIP TO BE IN LIQUID FORM AS A
STRONG SURFACE LOW MOVES ACROSS NORTHERN MN AND LAKE SUPERIOR.
BEST SATURATION WITH THIS SYSTEM IS ALONG AND NORTH OF THE SURFACE
LOW TRACK...SO LIQUID ACCUMULATIONS NOT LIKELY TO EXCEED A TENTH
OF AN INCH.
BREEZY SOUTHERLY WINDS ON THURSDAY WILL ABRUPTLY SHIFT TO THE WEST
FRIDAY MORNING AFTER THE PASSAGE OF A STRONG COLD FRONT. WINDS
WITHIN THE SFC TO 1 KM LAYER FROM 40 TO 45 KFT WILL RESULT IN
WINDY CONDITIONS...POSSIBLY REACHING ADVISORY CRITERIA DEPENDING
ON THE DEPTH OF THE MIXED LAYER. ABOVE FREEZING TEMPERATURES
WITH 30S ON THURSDAY AND 40S ON FRIDAY WILL TAKE A BIG BITE OUT
OF THE CURRENT SNOW PACK...ADDING COPIOUS MOISTURE TO THE BOUNDARY
LAYER...BUT STRONG WINDS SHOULD LIMIT FOG POTENTIAL.
CONTINUED MILD THROUGH THE WEEKEND WITH DAILY HIGHS FROM THE MID
30S TO MID 40S. STILL A CHANCE FOR RAIN/SNOW ON SUNDAY WITH THE
NEXT SHORT-WAVE MOVING THROUGH NORTHWEST FLOW ALOFT. OTHERWISE...
EXPECT DRY CONDITIONS INTO EARLY NEXT WEEK. TEMPERATURES TO TAKE A
BIT OF A DIP FOR MONDAY/TUESDAY...BUT STILL RELATIVELY MILD FOR
LATE FEBRUARY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 510 PM CST TUE FEB 16 2016
CHALLENGING FORECAST FOR FOG/CIGS TONIGHT THROUGH WED. LATEST
FOG/STRATUS SATELLITE IMAGERY POINTING TO CLEARING WORKING IN FROM
THE NORTH/NORTHWEST CURRENTLY...BUT RAP BUFKIT SOUNDINGS/RH FIELDS
BEARING THE MOST RESEMBLANCE TO WHAT/S OCCURRING. WILL LEAN ON THE
RAP FOR CLOUD TRENDS...WHICH SUGGEST IT WILL STAY SCT AT KLSE
THROUGH TONIGHT/MUCH OF WED. KRST IS ON THE EDGE OF THE LOW CLOUDS
TO THE WEST...SO A BIT MORE TRICKY. PLUS...WITH/IF CLEARING...LIGHT
FIELD SHOULD PROMOTE DEVELOPMENT OF FOG AND/OR STRATUS OVERNIGHT.
GOING TO PLAY KRST THIS WAY...UPDATING AS TRENDS REQUIRE.
MID/LOW CLOUDS LOOK TO RETURN LATE AFTERNOON WED FROM THE
WEST...WITH QUESTIONS ON HOW LOW THEY WILL GO. SEE MVFR
POTENTIAL...BUT WILL HOLD VFR FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION....RIECK
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
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
328 AM CST WED FEB 17 2016
.SHORT TERM...(Today)
ISSUED AT 328 AM CST WED FEB 17 2016
Overcast conditions persist across central and southeast Illinois
early this morning: however, 08z/2am satellite imagery is showing a
large clear area over much of Wisconsin into northern Illinois. With
northwesterly winds within the cloud layer, this clearing will
generally remain just N/NE of the KILX CWA. Meanwhile, plenty of
mid/high clouds are noted immediately upstream across the Dakotas
into Iowa. So other than a few brief breaks in the clouds
along/northeast of I-74, mostly cloudy skies will prevail today.
High temperatures will be in the middle to upper 30s.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 328 AM CST WED FEB 17 2016
The main weather story in the extended will be a pronounced warming
trend by the end of the week. As high pressure drifts east of the
region on Thursday, strong southerly winds will develop across
central Illinois. Forecast soundings suggest gusts of 25-30mph by
afternoon, which will help push high temperatures into the upper 40s
to around 50 degrees. A weak cold front will approach from the west
Thursday night into Friday, further tightening the pressure gradient
and increasing winds. NAM is showing a very strong 70-80mph 925mb
jet developing in advance of the front from the Ozarks northeastward
into Indiana by 12z Fri. Once the sun comes up, some of this
momentum will get mixed to the surface Friday morning, resulting
in wind gusts potentially approaching 50mph across the E/SE CWA.
Further north and west across the remainder of the area, gusts of
around 40mph will be common. May eventually need a Wind
Advisory, particularly along/east of I-57 where stronger gusts
will be focused. Thanks to the strong southerly flow and the
return of sunshine, temperatures will soar well into the 60s.
Front will have very little moisture to work with, so will pass
through the region with only a few clouds and no precip. Once it
exits, a mild Pacific origin airmass will prevail through the
upcoming weekend with high temperatures in the 50s for both Saturday
and Sunday. A potential fly-in-the-ointment for the weekend
forecast will be the development of a surface wave along the
departing boundary. All models show the front becoming parallel to
the zonal flow aloft and stalling along the Ohio River on Saturday.
A short-wave trough skirting through the Plains will then interact
with the boundary and a weak surface low will develop and track
eastward into Indiana by Sunday. However...the models do not agree
on how deep the surface low will become or how much precip will be
generated. The GEM is by far the most aggressive with the wave,
resulting in a 1006mb low over central Illinois by Sunday afternoon.
Since the approaching short-wave appears to be very minor within the
fast zonal flow pattern, have rejected this solution entirely.
Prefer the much weaker ECMWF, which shows a 1014mb low tracking
along the front Saturday night. As a result, will include chance
PoPs for rain across the southern half of the CWA along/south of the
I-72 corridor Saturday night, then SE of I-70 into Sunday. After
that, a return to cooler and drier conditions will be on tap for
early next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1150 PM CST TUE FEB 16 2016
The cold front has progressed SE of all TAF sites, with northwest
winds and MVFR clouds prevailing across the area. Despite some
holes in the cloud cover upstream approaching far NW IL, will
continue with MVFR cloud conditions through the rest of the night
and much of tomorrow, based on NAM forecast soundings. The GFS is
more optimistic with some clearing during the day tomorrow, but
RAP and HRRR support the longer period of cloud cover through
tomorrow, so will keep MVFR going at all terminal sites until
satellite trends indicate otherwise. A strong low level inversion
is projected to be the main feature keeping clouds in place. Winds
will initially increase slightly out of the northwest in the
post-frontal airmass, but speed will most likely remain less than
10kt. Advancing high pressure tomorrow will create variable wind
directions as the ridge axis moves across IL. Wind directions
should become south to southeast toward sunset tomorrow, with
speeds remaining less than 10kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1151 PM CST TUE FEB 16 2016
.UPDATE...
ISSUED AT 900 PM CST TUE FEB 16 2016
A band of light rain and snow has been progressing southeast
across our forecast area, triggered by lift ahead of the advancing
cold front. Model analysis shows that frontal circulation will
affect our southeastern counties until shortly after midnight.
Thermal profiles are supporting enough melting in the lowest
levels for light rain to reach the ground in areas south of
Lincoln to Mattoon. Observation reports north of there have been
consistently showing light snow, but it appears possible that some
light rain could be reaching the ground farther north. Have
updated the PoP and weather grids to match expected trends the
rest of the night.
A few holes in the cloud cover upstream could produce widely
varying low temperatures later tonight, if they reach our northern
counties. Clear areas could see colder lows by several degrees.
Northwest winds behind the cold front should increase enough to
keep dense fog out of the picture, but patchy fog could still
develop. Have not included a mention of fog, as visibility should
remain 4 miles or better through morning.
&&
.SHORT TERM...(Tonight)
ISSUED AT 248 PM CST TUE FEB 16 2016
Initial area of rain/snow continues to push southeast and mainly
covers far southern Illinois this afternoon. However, with the
northern upper wave, rain/snow showers have been a bit more numerous
than first thought. Have recently updated the afternoon forecast to
increase the PoP`s a bit with scattered rain/snow showers over areas
along and north of I-74. Some clear spots have also developed
between I-74 and I-72, which has allowed temperatures in these areas
to increase into the upper 30s to around 40 degrees.
High pressure over the central Plains will track into Missouri
tonight. Large cloud shield extends northwest into southern
Minnesota, and a low level inversion around 850 mb should bottle up
the moisture below it, preventing any wholesale clearing trends
overnight in our area. Temperatures expected to fall into the lower
20s across the far northern CWA, but range into the upper 20s south
of I-72.
.LONG TERM...(Wednesday through Tuesday)
ISSUED AT 248 PM CST TUE FEB 16 2016
Quiet weather and unseasonably mild conditions will be the rule over
the next several days across central and southeast Illinois. A long
advertised warm up will begin by late Wednesday as upper-level
heights gradually rise and southerly low level flow develops. The
warmest day of the next several will be Friday, where widespread
highs in the 60s are anticipated. However, temperatures that mild
this time of year typically don`t occur without strong winds
transporting them into the area. This scenario is no exception, with
southerly wind gusts to around 30 MPH likely on Thursday and gusts
to around 40 MPH expected Friday.
A cold front will come through the area by late Friday, but it is
expected to come through dry. The upper level flow is progged to
stay zonal through the weekend in the wake of the front, so only a
modest cool down (highs mainly in the 50s) is expected through
Sunday. A fast moving short wave in the zonal flow will bring a low
chance for rain to the area by Saturday night into Sunday, but would
not be surprised to see most areas remaining dry.
Ridging is forecast to build across the eastern Pacific and western
North America to start the next work week. This building ridge will
allow northern stream energy to dig across eastern North America for
Monday and Tuesday. While no significant precipitation is
anticipated with the approach of this troffing and associated colder
air, but temperatures will trend back toward normal levels for late
February (highs around 40).
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1150 PM CST TUE FEB 16 2016
The cold front has progressed SE of all TAF sites, with northwest
winds and MVFR clouds prevailing across the area. Despite some
holes in the cloud cover upstream approaching far NW IL, will
continue with MVFR cloud conditions through the rest of the night
and much of tomorrow, based on NAM forecast soundings. The GFS is
more optimistic with some clearing during the day tomorrow, but
RAP and HRRR support the longer period of cloud cover through
tomorrow, so will keep MVFR going at all terminal sites until
satellite trends indicate otherwise. A strong low level inversion
is projected to be the main feature keeping clouds in place. Winds
will initially increase slightly out of the northwest in the
post-frontal airmass, but speed will most likely remain less than
10kt. Advancing high pressure tomorrow will create variable wind
directions as the ridge axis moves across IL. Wind directions
should become south to southeast toward sunset tomorrow, with
speeds remaining less than 10kt.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Geelhart
LONG TERM...BAK
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS GOODLAND KS
302 AM MST WED FEB 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 AM MST WED FEB 17 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANAYSINS SHOW LARGE
SCALE RIDGE ACROSS WESTERN US WITH NW FLOW ACROSS THE PLAINS. AT
THE SURFACE LOW PRSSURE IS IN PLACE FROM EASTERN COLROADO AND
NEBRASKA WITH TROUGH AXIS ACROSS OUR CWA.
MAIN FORECAST ISSUE CONTINUES TO BE POTENTIAL FOR RECORD
TEMPERATURES AND HIGH IMPACT FIRE WEATHER EVENT THURSDAY. SEE FIRE
WEATHER SECTION FOR DEAILS ON FIRE WEATHER WATCH.
TODAY-FRIDAY NIGHT...LARGE SCALE RIDGE WILL TRANSITION EASTWARD
THROUGH THURSDAY WITH DEEP SW FLOW DEVELOPING THURSDAY ON WESTERN
EXTNENT OF UPPER RIDGE AHEAD OF APPROACHING TROUGH. A SHORTWAVE
TROUGH WILL MOVE THROUGH THE REGION WITH A DRY COLD FRONT PASSAGE
THURSDAY NIGHT INTO FRIDAY. DRY CONDTIONS ARE EXPECTED THROUGH THESE
PERIODS. MODEL TEMP PROFLES SHOW GOOD MIXING HEIGHTS IN THE 830-
800MB RANGE THURSDAY...AND THIS WILL HELP MIX STRONGER WINDS TO THE
SURFACE AIDED BY UNIDIRECTIONAL GRADIENT THROUGH 500MB. THIS WOULD
SUPPORT GUSTS IN THE 35-45 MPH RANGE (ASSUMING INCREASING CIRRUS
DOESNT COMPLICATE THINGS FOR US).
HIGH TEMPERATURES TODAY AND THURSDAY WILL BE MUCH ABOVE NORMAL WITH
RECORD HIGHS LIKELY ACROSS OUR CWA ON THURSDAY. LATEST STATISTICAL
GUIDANCE HAS TRENDED A LITTLE WARMER ON HIGHS BOTH DAYS. BASED ON
BIAS CORRECTED 2M TEMPS AND STANDARD BIAS OFF 925MB/850MB TEMPS
ALOFT HIGHS TODAY COULD BE NEAR 70F...AND IN THE LOW TO MID 80S AT
SOME LOCATIONS THURSDAY. A FEW MONTHLY RECORDS COULD BE IN PLAY FOR
THURSDAY. LOW TEMPEATURES WILL ALSO BE UNSEASONBALY HIGH TONIGHT
AND THURSDAY NIGHT...PARTICUARLY THURSDAY NIGHT WHERE WINDY
CONDTIONS WILL KEEP CONDITIONS WELL MIXED DESPITE CAA BEHIND
FROPA. IN FACT WE MAY BE LOOKING AT RECORD HIGH MINS BOTH NIGHTS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 208 AM MST WED FEB 17 2016
FOR THE EXTENDED PERIOD...THE TRI STATE REGION WILL CONTINUE TO SEE
MAINLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. MID LEVEL FLOW
AT 500MB WILL REMAIN ZONAL THRU THE UPCOMING WEEKEND WITH ANOTHER
BROAD UPPER RIDGE BUILDING ON THE WEST COAST BY THE BEGINNING OF
NEXT WEEK...THEN SHIFTING EASTWARD INTO THE ROCKIES BY MIDWEEK NEXT
WEEK.
BY MONDAY NIGHT...MODELS CONTINUE TO SHOW WEAK SHORTWAVE MOVE SE
ALONG THE EAST SIDE OF THE UPPER RIDGE...THRU EASTERN COLORADO
THEN QUICKLY SOUTH OF THE CWA GOING INTO TUESDAY. BASED ON
CURRENT TRACK...MOST OF THE QPF WILL AVOID THE REGION...LEAVING
ONLY A SLIGHT CHANCE FOR LIGHT RAIN.
WARMEST TIME FRAME IN THE EXTENDED WILL OCCUR ON SATURDAY WITH
WESTERLY ZONAL DOWNSLOPE FLOW OVER THE AREA. LOOKING FOR 60S ON
THAT DAY...WITH A DOWNTREND INTO THE 50S SUNDAY AND MONDAY AS
WINDS SHIFT TO MORE NW ALLOWING FOR COLDER AIR TO FILTER INTO THE
REGION. FOR TUESDAY INTO WEDNESDAY...WITH THE PASSAGE OF THE WEAK
SHORTWAVE...HIGHS WILL ONLY REACH INTO THE U40S TUESDAY WITH NLY A
REBOUND TO AROUND 50F FOR WEDNESDAY. OVERNIGHT LOWS WILL START OFF
INTO THE LOWER 30S SATURDAY NIGHT...W/ 20S FOR THE REMAINDER OF
THE OVERNIGHT PERIODS INTO MIDWEEK NEXT WEEK. SATURDAY THRU MONDAY
WILL END UP HAVING ABOVE NORMAL CONDITIONS...WHILE OVERALL FOR
TUESDAY AND WEDNESDAY...NEAR NORMAL WITH THE ADDITION OF COLDER
AIR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1020 PM MST TUE FEB 16 2016
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WEST TO SOUTHWEST
WINDS IN THE 6 TO 11 KNOT RANGE WILL SHIFT TO THE SOUTH TO
SOUTHEAST DURING THE AFTERNOON HOURS. THE WINDS AT KGLD COULD
GUST TO NEAR 21 KNOTS IN THE AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MST WED FEB 17 2016
MODELS SHOW INCREASING CIRRUS AHEAD OF APPROACHING
TROUGH ON THURSDAY WHICH COULD COMPLICATE MIXING HEIGHTS...HOWEVER
EVEN THEN IT APPEARS HIGHLY LIKELY THAT THE STRONG GRADIENT IN
PLACE OVER OUR CWA WILL STILL SUPPORT RED FLAG CRITERIA WINDS.
FUELS CONTINUE TO BE A QUESTION NORTH OF THE CURRENT WATCH DEPITE
LIKELYHOOD OF RH/WIND CRITIERA...DUE TO IMPACTS OF RECENT SNOW
MELT. THIS MAY NOT HAVE AS MUCH OF AN IMPACT ON ONE HOUR FUEL
CURING OR POTENIAL FOR LARGE GRASS FIRES IN THE FORECAST
CONDTIONS...PARTICUARLY SINCE WE HAVE HAD SEVERAL VERY MILD/DRY
DAYS (AND ANOTHER TODAY). NO CHANGES TO FIRE WEATHER WATCH DURING
THIS UPDATE CYCLE TO ALLOW DAY SHIFT TO COORDINATE FUEL CONDTIONS
WITH OUR FIRE WEATHER PARTNERS.
&&
.CLIMATE...
ISSUED AT 300 AM MST WED FEB 17 2016
RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY.
SITE.............DAILY RECORD...CURRENT FORECAST
GOODLAND, KS.........74...............79
MCCOOK, NE...........82...............76
BURLINGTON,CO........74...............79
HILL CITY,KS.........75...............82
COLBY, KS............81...............79
TRIBUNE, KS..........79...............81
YUMA, CO.............73...............75
CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS...
GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS)
MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS)
BURLINGTON...82 (02-11-1962)
HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS)
COLBY........83 (02-12-1911)
TRIBUNE......81 (02-20-1981)
YUMA.........79 (02-12-1962 AND PREVIOUS YEARS)
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR KSZ027>029-041-042.
CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR COZ254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...BULLER
FIRE WEATHER...DR
CLIMATE...DR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1219 AM CST WED FEB 17 2016
.UPDATE...
ISSUED AT 1218 AM CST WED FEB 17 2016
WEB CAMS AND SURFACE OBSERVATIONS CONTINUED TO SHOW AREAS OF FOG IN
SOUTHWEST AND PARTS OF SOUTH CENTRAL NORTH DAKOTA. HAVE ADDED
MENTION OF FOG INTO CENTRAL NORTH DAKOTA AS WELL AS THE EARLIER
UPDATE ADDING THE MENTION IN THE SOUTHWEST. REGIONAL RADARS STILL
INDICATING PRECIPITATION FROM NORTHWEST TO SOUTH CENTRAL NORTH
DAKOTA. MOST WEB CAMS AND OBS INDICATING LIGHT SNOW...HOWEVER NOTED
THE UNKNOWN PRECIP AT HAZEN...AND STILL THINKING THAT FREEZING
DRIZZLE WILL BE POSSIBLE ON THE WESTERN EDGE OF THE PRECIPITATION AS
IT CONTINUES MOVING EAST/SOUTHEASTWARD SLOWLY. FORECAST SOUNDINGS
STILL INDICATE DRYING ALOFT ALLOWING SUPERCOOLED LOWER LEVELS AND
POSSIBILITY OF FREEZING DRIZZLE. DO NOT OBSERVE A TREND IN RADAR
LOOPS THAT WOULD INDICATE A DOWNTREND OF AREA OF PRECIPITATION...AND
THINKING IT MAY LINGER A BIT LONGER THAN PREVIOUSLY THOUGHT. THUS
KEPT CHANCES IN THE NORTHWEST TO SOUTH CENTRAL AREA FOR A FEW MORE
HOURS.
UPDATE ISSUED AT 920 PM CST TUE FEB 16 2016
WEB CAMS AND SURFACE OBSERVATIONS SHOW AREAS OF FOG HAVE FORMED
ACROSS THE SOUTHWEST INTO THE FAR NORTHWEST. WILL ADD FOG TONIGHT.
THE BAND OF SNOW CONTINUES ACROSS THE CENTRAL WHILE SLOWLY SHRINKING.
JUST NEED TO REFINE POPS A BIT FOR THIS. TRIMMED BACK THE AREA OF
FREEZING RAIN/DRIZZLE. DO NOT SEE MUCH AT THIS TIME BUT STILL
POSSIBLE LATER AS THE MID/HIGH LEVELS DRY OUT.
UPDATE ISSUED AT 603 PM CST TUE FEB 16 2016
FORECAST TRENDING WELL SO FAR. MIX OF RAIN AND SNOW CHANGING OVER
TO SNOW WEST AND MAINLY SNOW CENTRAL. GETTING A FAIRLY NARROW
AND FOCUSED BAND OF PRECIPITATION ON RADAR THAT ALIGNS WELL WITH
THE H850-H700 FRONTOGENESIS. WILL BE WATCHING FOR THE FORECAST
FREEZING DRIZZLE TO SHOW UP LATE THIS EVENING AFTER THE RAIN/SNOW
MOVES THROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
THE HIGHLIGHT IN THE SHORT TERM IS THE POTENTIAL FOR A WINTRY MIX
TONIGHT.
WE ARE CARRYING UP TO AROUND AN INCH OF SNOW IN THE FORECAST FROM
NORTHWEST INTO SOUTH CENTRAL NORTH DAKOTA THROUGH TONIGHT ROUGHLY
ALONG A LINE FROM WILLISTON TO BISMARCK AND ASHLEY. THAT IS BASED
ON A BLEND OF THE 12 UTC GLOBAL MODEL QPF GUIDANCE AND THE TIME-
LAGGED HIGH-RESOLUTION MODEL SUITE /INCLUDING THE RAP AND HRRR/.
RADAR ECHOES ARE INTENSIFYING SOUTHWEST OF THAT LINE AS OF 2145
UTC AS MID-LEVEL FRONTOGENESIS INCREASES...AND RECENT RAP OUTPUT
SUGGESTS THE FRONTOGENESIS BASED IN THE 850-700 MB LAYER WILL BE
MAXIMIZED OVER CENTRAL ND AROUND 01 UTC. GIVEN A QUICK BURST OF
MODERATE TO STRONG QG-FORCING TIED TO THE EXIT REGION OF A 110 KT
300-MB JET STREAK...THE AGEOSTROPHIC CIRCULATION WILL LIKELY BE
SUFFICIENTLY DEEP FOR A BRIEF PERIOD OF NOTEWORTHY PRECIPITATION
RATES. HOWEVER...RUN-TOTAL QPF FROM THE LAST FEW RUNS OF THE RAP
AND HRRR HAS BEEN TRENDING A BIT LOWER THAN ITS EARLIER FLAVORS
AND THE RESIDENCE TIME OF THE FORCING WILL BE SHORT IN ANY ONE
PLACE...WHICH IS WHY WE HAVE DOWNPLAYED THE OVERALL SNOW EVENT.
RELATIVELY WARM LOW- AND MID-LEVEL THERMAL PROFILES WILL LIKELY
PREVENT EFFICIENT SNOW GROWTH TOO...LIMITING THE SNOW-TO-LIQUID
RATIOS TO AROUND 11 TO 1. EVEN SO...GIVEN THE POTENTIAL FOR A
PERIOD OF STRONG FRONTOGENESIS...WE WILL HAVE TO MONITOR LATER
TRENDS IN CASE ADJUSTMENTS TO THE SNOWFALL FORECAST ARE NEEDED.
NOTE THAT MAXIMUM TEMPERATURES ALOFT SUGGEST A MIX OF RAIN AND
SNOW OR OUTRIGHT RAIN IN SOUTHWEST ND THROUGH THIS EVENING. THAT
IDEA IS BEING CARRIED IN THE FORECAST...BUT OBSERVATIONAL TRENDS
HAVE SUGGESTED WET BULB COOLING HAS BEEN FAVORING SNOW THUS FAR.
FINALLY...WE ARE STILL ADVERTISING A CHANCE OF LIGHT FREEZING
DRIZZLE TONIGHT ON THE BACK SIDE OF THE PRECIPITATION...AND ALL
THE WAY INTO WEDNESDAY MORNING IN CENTRAL ND. FORECAST SOUNDINGS
SHOW DRYING ALOFT AND A LINGERING STRATUS LAYER THAT IS MAINLY
WARMER THAN -10 C...SUPPORTING POTENTIAL SUPERCOOLED DROPS AND
THUS FREEZING DRIZZLE.
BY WEDNESDAY AFTERNOON...THE WEATHER WILL HAVE QUIETED DOWN WITH
THE AREA BETWEEN WAVES. STRATUS /LOW CLOUDS/ COULD HINDER WARMING
IF IT IS THICK ENOUGH...BUT THE 12 UTC MULTI-MODEL CONSENSUS THAT
WE USED TO BUILD THE FORECAST CALLS FOR HIGHS FROM THE LOWER 30S F
IN JAMESTOWN TO THE LOWER 50S F IN BOWMAN.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 PM CST TUE FEB 16 2016
A PROGRESSIVE FLOW WITH A MEAN UPPER RIDGE IN THE WEST AND A TROUGH
IN THE EAST WILL RESULT IN SERIES OF SYSTEMS WITH MIXED
PRECIPITATION AND PERIODS OF WINDY CONDITIONS.
BEGINNING WEDNESDAY NIGHT INTO FRIDAY...BOTH THE NAM/GFS ARE
ADVERTISING AN H85 COLD POCKET TO WORK ACROSS CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT THROUGH THURSDAY MORNING. NAM/GFS BUFKIT SOUNDINGS
AGREE THAT ENOUGH OMEGA WITHIN THE SUPERCOOLED WATER DROPLET REGIME
COULD PRODUCE A LIGHT FREEZING RAIN POTENTIAL BEGINNING 09Z-12Z
THURSDAY NOON THURSDAY. HAVE ADDED A SLIGHT CHANCE FOR LIGHT
FREEZING RAIN INTO THE GRIDS ACROSS CENTRAL NORTH DAKOTA FROM 09Z-
18Z THURSDAY. WARM AIR ADVECTION WILL OVERSPREAD THE REGION THROUGH
00Z FRIDAY BEFORE A DOUBLE AREA OF SURFACE LOW PRESSURE AND
ASSOCIATED SHORTWAVE TROUGH ALOFT SHIFT ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THURSDAY NIGHT INTO FRIDAY. A MIX OF RAIN/SNOW/LIGHT
FREEZING RAIN ALL POSSIBLE WITH THIS SYSTEM BASED UPON LOCATION AND
THERMODYNAMIC PROFILE. THE OTHER SIGNIFICANT WEATHER ELEMENT WILL BE
WIND LATE THURSDAY NIGHT THROUGH FRIDAY AFTERNOON. STRONGEST WINDS
ARE ADVERTISED FROM MID MORNING FRIDAY THROUGH MID AFTERNOON FRIDAY
WITH BOUNDARY LAYER WINDS OF BETWEEN 40KT AND 45KT ACROSS THE
SOUTHWEST...AND 30KT TO 35KT MOST ELSEWHERE. POTENTIAL HIGH WIND
WARNING SOUTHWEST WITH A SOLID WIND ADVISORY MOST OF WESTERN AND
CENTRAL NORTH DAKOTA DURING THIS TIME. THE TIME WINDOW OVERALL IS
BRIEF BUT WOULD STILL BE WORTHY OF THE ABOVE IF DATA REMAINS
CONSISTENT.
FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR
ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER
SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST
PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY
THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY
NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO
NORTHWEST WIND OF 20 TO 30 MPH.
SUNDAY NIGHT THROUGH MONDAY NIGHT...THE NEXT SHORTWAVE IS FORECAST
TO SHIFT ACROSS EASTERN MONTANA AND FAVOR SOUTHWEST NORTH DAKOTA
MONDAY AFTERNOON THROUGH MONDAY NIGHT WITH A SLIGHT CHANCE OF SNOW.
MILD HIGH TEMPERATURES THURSDAY AND FRIDAY WITH UPPER 50S SOUTHWEST
TO MID 40S CENTRAL AND MID 30S TURTLE MOUNTAINS. MILD AIR CONTINUES
INTO FRIDAY WITH GOOD MIXING ALOFT AND WIDESPREAD/MORE UNIFORM HIGHS
IN THE 40S TO LOWER 50S SOUTHWEST. A GRADUAL COOL DOWN SATURDAY
THROUGH TUESDAY...BUT REMAINING ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1218 AM CST WED FEB 17 2016
AT MIDNIGHT CST...A FRONTAL BOUNDARY EXTENDED ACROSS EASTERN
MONTANA...THE FAR SOUTHWEST CORNER OF NORTH DAKOTA...AND INTO
WESTERN SOUTH DAKOTA...SEPARATING MILD AIR TO THE WEST FROM COOLER
AIR EAST. WEST WIND FLOW ABOVE/OVER THE FRONTAL BOUNDARY WILL BE THE
FOCUS FOR CONTINUED LIGHT SNOW AND POSSIBLY FREEZING DRIZZLE ACROSS
CENTRAL NORTH DAKOTA THIS MORNING. MAINLY IFR THIS MORNING
WITH IFR CIGS AND MVFR/IFR VSBYS AT TIMES IN FOG. CONDITIONS
GRADUALLY IMPROVING TO MVFR/VFR ON WEDNESDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 359 PM CST TUE FEB 16 2016
FLUCTUATING WATER LEVELS WILL CONTINUE ON THE MISSOURI RIVER
THROUGH BISMARCK AND MANDAN THROUGH MIDWEEK. SEE THE HYDROLOGIC
OUTLOOK ON OUR WEB PAGE FOR FULL DETAILS. THE LACK OF UPSTREAM
ICE AND WARMER TEMPERATURES WILL HELP TO LOWER THE RISK OF HIGHER
WATER OVER THE COMING DAYS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...CJS
LONG TERM...KS
AVIATION...JV
HYDROLOGY...CJS/AJS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
317 AM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS CENTRAL PA TODAY...FOLLOWED
BY HIGH PRESSURE THURSDAY. LOW PRESSURE WILL TRACK NORTH OF
PENNSYLVANIA THROUGH THE GREAT LAKES FRIDAY INTO SATURDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WEAK SHORTWAVE AND OROGRAPHIC LIFT OF THE SHALLOW COLD AIRMASS AND
LIMITED MOISTURE OFF THE GLAKES WAS RESULTING IN SOME VERY LIGHT
FLURRIES (AND PATCHY FREEZING DRIZZLE NEAR AND TO THE WEST OF
ROUTE 219 ACROSS THE LAURELS). SKIES WILL STAY OVERCAST EARLY
TODAY WITH A 5-8 KT WNW SFC WIND AND TEMPS DROPPING SLOWLY FROM
THEIR 08Z READINGS RANGING FROM IN THE UPPER 20S ACROSS THE NRN
AND WESTERN MTNS...TO THE 30S ELSEWHERE.
NO HEADLINES PLANNED ATTM...AS ANY -FZDZ SHOULD BE LOW IMPACT AND
LIMITED TO JUST HIGH LOCALIZED FAVORED UPSLOPE AREAS ON THE RIDGES
AND WEST-FACING SLOPES OF THE LAURELS. THE FRESHLY TREATED ROAD
SURFACES WILL HELP TO GREATLY MINIMIZE THE ADVERSE IMPACT ON
TRAVEL.
EXPECT MIN TEMPS AT DAWN TO RANGE FROM THE L20S ACROSS THE NW
MTNS...TO ARND 30F OVR THE SE COUNTIES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM THURSDAY/...
A COLD FRONT WILL SWING SE ACROSS THE REGION TODAY BRINGING AN
INCREASING CHC OF SNOW SHOWERS AND SOME LIGHT ACCUMS OF AROUND ONE
INCH ACROSS THE NRN MTNS (BEGINNING DURING THE MID TO LATE MORNING
HOURS) AND EVENTUALLY OVER THE LAUREL LATE THIS MORNING AND THIS
AFTERNOON. MDL DATA INDICATES THE PARENT SHORTWAVE WEAKENS AND
LIFTS NORTH OF PA TODAY. HOWEVER...A BKN BAND OF -SHSN IS FORECAST
TO SLIDE ACROSS THE NW MTNS BTWN 12Z-15Z. ALTHOUGH THE TUESDAY 18Z
GEFS SUPPORTED LIKELY POPS ACROSS THE NW MTNS THRU MIDDAY AND
SLIGHTLY LOWER POPS FURTHER SOUTH ALONG THE ALLEGHENIES...THE
LATEST VERSIONS OF THE HRRR AND 03Z SREF APPEAR TO BRING THE BEST
CHC OF SNOW SHOWERS ACROSS THE NW MTNS...AND LAURELS AFTER 19Z/21Z
RESPECTIVELY. ELSEWHERE...DOWNSLOPING WEST WIND SHOULD LIMIT
PRECIP TO SCT FLURRIES EAST OF THE MTNS.
SKIES EXPECTED TO RANGE FROM CLOUDY ACROSS THE W MTNS DURING THE
DAY TODAY...TO PTSUNNY OVR THE LOWER SUSQ VALLEY. MDL 8H TEMPS
ARND 8C SHOULD TRANSLATE TO MAX TEMPS FROM THE L30S ACROSS THE
ALLEGHENY PLATEAU...TO THE L40S OVR THE SUSQ VALLEY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
VERY DRY AIRMASS IN PLACE FOR THU. DID EDGE DEWPOINTS DOWN.
LOOKING A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR
LATE IN THE WEEK.
MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON
POPS WHERE POSSIBLE. ONLY A FEW RAIN SHOWERS IF THAT.
OVERALL PACKAGE LOOKS GOOD...DID NUDGE TEMPS A DEGREE HERE
AND THERE.
COLDER AIR WORKS BACK IN AFTER THE WEEKEND.
EC AND OTHER MODELS MORE OFF THE COAST WITH ANY STORM FOR
MID WEEK NOW. AS WITH RECENT CASES...COMPLICATED WITH 3 OR
MORE PIECES OF UPPER LVL ENERGY. FOR NOW WENT WITH LOW POPS
ACROSS THE SE TO MATCH IN WITH OTHERS.
THE WEATHER THE NEXT SEVERAL DAYS WILL ALLOW FOR SOME RUNOFF
DURING THE DAY. A NICE DRY SPELL TO DRY THINGS OUT SOME. ENJOY
THE BREAK FROM THE RECENT STORMY...WET CONDITIONS. SOME ICE
FORMATION WED AND THU NIGHT...BUT LIMITED AMT OF TIME BELOW
FREEZING FOR VERY MUCH RIVER/STREAM ICE FORMATION.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
SHORTWAVE SLIDING SW-NE OVERHEAD EARLY THIS MORNING KEEPING IFR
RESTRICTIONS IN PLACE OVER WESTERN AREAS...WHILE MVFR CIGS SPREAD
ACROSS REMAINDER OF CWA FOR SEVERAL HOURS PRE-DAWN. COULD EVEN BE
A BIT OF PATCHY DZ/FZDZ IN SPOTS.
TROUGH SLIDES THROUGH ON WED...AS RESTRICTIONS CONTINUE MAINLY OVER
WESTERN HIGHER TERRAIN WITH LIGHT SNOW SHOWERS. THEY MAY AGAIN
SPILL INTO THE CENTRAL MTNS FOR A TIME...BUT OTHERWISE CENTRAL AND
SE WILL REMAIN VFR.
HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW
PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES
FRIDAY INTO SATURDAY.
OUTLOOK...
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE
OVER THE WEST /AND POSS CENTRAL/ ALONG WITH POTENTIAL FOR LIGHT
SNOW.
THU...MAINLY VFR.
FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE.
SAT-SUN...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/FITZGERALD
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT/FITZGERALD
LONG TERM...MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
421 AM MST WED FEB 17 2016
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 300 AM MST WED FEB 17 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE
SCALE RIDGE ACROSS WESTERN US WITH NW FLOW ACROSS THE PLAINS. AT
THE SURFACE LOW PRESSURE IS IN PLACE FROM EASTERN COLORADO AND
NEBRASKA WITH TROUGH AXIS ACROSS OUR CWA.
MAIN FORECAST ISSUE CONTINUES TO BE POTENTIAL FOR RECORD
TEMPERATURES AND HIGH IMPACT FIRE WEATHER EVENT THURSDAY. SEE FIRE
WEATHER SECTION FOR DETAILS ON FIRE WEATHER WATCH.
TODAY-FRIDAY NIGHT...LARGE SCALE RIDGE WILL TRANSITION EASTWARD
THROUGH THURSDAY WITH DEEP SW FLOW DEVELOPING THURSDAY ON WESTERN
EXTENT OF UPPER RIDGE AHEAD OF APPROACHING TROUGH. A SHORTWAVE
TROUGH WILL MOVE THROUGH THE REGION WITH A DRY COLD FRONT PASSAGE
THURSDAY NIGHT INTO FRIDAY. DRY CONDITIONS ARE EXPECTED THROUGH THESE
PERIODS. MODEL TEMP PROFILES SHOW GOOD MIXING HEIGHTS IN THE 830-
800MB RANGE THURSDAY...AND THIS WILL HELP MIX STRONGER WINDS TO THE
SURFACE AIDED BY UNIDIRECTIONAL GRADIENT THROUGH 500MB. THIS WOULD
SUPPORT GUSTS IN THE 35-45 MPH RANGE (ASSUMING INCREASING CIRRUS
DOESNT COMPLICATE THINGS FOR US).
HIGH TEMPERATURES TODAY AND THURSDAY WILL BE MUCH ABOVE NORMAL WITH
RECORD HIGHS LIKELY ACROSS OUR CWA ON THURSDAY. LATEST STATISTICAL
GUIDANCE HAS TRENDED A LITTLE WARMER ON HIGHS BOTH DAYS. BASED ON
BIAS CORRECTED 2M TEMPS AND STANDARD BIAS OFF 925MB/850MB TEMPS
ALOFT HIGHS TODAY COULD BE NEAR 70F...AND IN THE LOW TO MID 80S AT
SOME LOCATIONS THURSDAY. A FEW MONTHLY RECORDS COULD BE IN PLAY FOR
THURSDAY. LOW TEMPERATURES WILL ALSO BE UNSEASONABLY HIGH TONIGHT
AND THURSDAY NIGHT...PARTICULARLY THURSDAY NIGHT WHERE WINDY
CONDITIONS WILL KEEP CONDITIONS WELL MIXED DESPITE CAA BEHIND
FROPA. IN FACT WE MAY BE LOOKING AT RECORD HIGH MINS BOTH NIGHTS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 208 AM MST WED FEB 17 2016
FOR THE EXTENDED PERIOD...THE TRI STATE REGION WILL CONTINUE TO SEE
MAINLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. MID LEVEL FLOW
AT 500MB WILL REMAIN ZONAL THRU THE UPCOMING WEEKEND WITH ANOTHER
BROAD UPPER RIDGE BUILDING ON THE WEST COAST BY THE BEGINNING OF
NEXT WEEK...THEN SHIFTING EASTWARD INTO THE ROCKIES BY MIDWEEK NEXT
WEEK.
BY MONDAY NIGHT...MODELS CONTINUE TO SHOW WEAK SHORTWAVE MOVE SE
ALONG THE EAST SIDE OF THE UPPER RIDGE...THRU EASTERN COLORADO
THEN QUICKLY SOUTH OF THE CWA GOING INTO TUESDAY. BASED ON
CURRENT TRACK...MOST OF THE QPF WILL AVOID THE REGION...LEAVING
ONLY A SLIGHT CHANCE FOR LIGHT RAIN.
WARMEST TIME FRAME IN THE EXTENDED WILL OCCUR ON SATURDAY WITH
WESTERLY ZONAL DOWNSLOPE FLOW OVER THE AREA. LOOKING FOR 60S ON
THAT DAY...WITH A DOWNTREND INTO THE 50S SUNDAY AND MONDAY AS
WINDS SHIFT TO MORE NW ALLOWING FOR COLDER AIR TO FILTER INTO THE
REGION. FOR TUESDAY INTO WEDNESDAY...WITH THE PASSAGE OF THE WEAK
SHORTWAVE...HIGHS WILL ONLY REACH INTO THE U40S TUESDAY WITH NLY A
REBOUND TO AROUND 50F FOR WEDNESDAY. OVERNIGHT LOWS WILL START OFF
INTO THE LOWER 30S SATURDAY NIGHT...W/ 20S FOR THE REMAINDER OF
THE OVERNIGHT PERIODS INTO MIDWEEK NEXT WEEK. SATURDAY THRU MONDAY
WILL END UP HAVING ABOVE NORMAL CONDITIONS...WHILE OVERALL FOR
TUESDAY AND WEDNESDAY...NEAR NORMAL WITH THE ADDITION OF COLDER
AIR.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 421 AM MST WED FEB 17 2016
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. WINDS WILL SHIFT FROM THE WEST TO THE SOUTH-SOUTHEAST
THROUGH THE DAY AND INCREASE MAINLY AT KGLD. WIND GUSTS THIS
AFTERNOON WILL RANGE FROM 15-22 KT WITH PEAK DAYTIME HEATING.
LOW LEVEL WIND SHEER WILL BE POSSIBLE AT BOTH TERMINALS AS A
STRONG LLJ DEVELOPS 05-06Z. THE STRONGEST WINDS ALOFT SHOULD
TRANSITION EASTWARD AFTER 09Z.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MST WED FEB 17 2016
MODELS SHOW INCREASING CIRRUS AHEAD OF APPROACHING
TROUGH ON THURSDAY WHICH COULD COMPLICATE MIXING HEIGHTS...HOWEVER
EVEN THEN IT APPEARS HIGHLY LIKELY THAT THE STRONG GRADIENT IN
PLACE OVER OUR CWA WILL STILL SUPPORT RED FLAG CRITERIA WINDS.
FUELS CONTINUE TO BE A QUESTION NORTH OF THE CURRENT WATCH DESPITE
LIKELIHOOD OF RH/WIND CRITERIA DUE TO IMPACTS OF RECENT SNOW MELT.
THIS MAY NOT HAVE AS MUCH OF AN IMPACT ON ONE HOUR FUELS OR
POTENTIAL FOR LARGE GRASS FIRES IN THE FORECAST
CONDITIONS...PARTICULARLY SINCE WE HAVE HAD SEVERAL VERY MILD/DRY
DAYS (AND ANOTHER TODAY). NO CHANGES TO FIRE WEATHER WATCH DURING
THIS UPDATE CYCLE TO ALLOW DAY SHIFT TO COORDINATE FUEL CONDITIONS
WITH OUR FIRE WEATHER PARTNERS.
&&
.CLIMATE...
ISSUED AT 300 AM MST WED FEB 17 2016
RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY.
SITE.............DAILY RECORD...CURRENT FORECAST
GOODLAND, KS.........74...............79
MCCOOK, NE...........82...............76
BURLINGTON,CO........74...............79
HILL CITY,KS.........75...............82
COLBY, KS............81...............79
TRIBUNE, KS..........79...............81
YUMA, CO.............73...............75
CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS...
GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS)
MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS)
BURLINGTON...82 (02-11-1962)
HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS)
COLBY........83 (02-12-1911)
TRIBUNE......81 (02-20-1981)
YUMA.........79 (02-12-1962 AND PREVIOUS YEARS)
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR KSZ027>029-041-042.
CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR COZ254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...DR
FIRE WEATHER...DR
CLIMATE...DR
AREA FORECAST DISCUSSION...CORRECTED
NWS GOODLAND KS
306 AM MST WED FEB 17 2016
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 300 AM MST WED FEB 17 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE
SCALE RIDGE ACROSS WESTERN US WITH NW FLOW ACROSS THE PLAINS. AT
THE SURFACE LOW PRESSURE IS IN PLACE FROM EASTERN COLORADO AND
NEBRASKA WITH TROUGH AXIS ACROSS OUR CWA.
MAIN FORECAST ISSUE CONTINUES TO BE POTENTIAL FOR RECORD
TEMPERATURES AND HIGH IMPACT FIRE WEATHER EVENT THURSDAY. SEE FIRE
WEATHER SECTION FOR DETAILS ON FIRE WEATHER WATCH.
TODAY-FRIDAY NIGHT...LARGE SCALE RIDGE WILL TRANSITION EASTWARD
THROUGH THURSDAY WITH DEEP SW FLOW DEVELOPING THURSDAY ON WESTERN
EXTENT OF UPPER RIDGE AHEAD OF APPROACHING TROUGH. A SHORTWAVE
TROUGH WILL MOVE THROUGH THE REGION WITH A DRY COLD FRONT PASSAGE
THURSDAY NIGHT INTO FRIDAY. DRY CONDITIONS ARE EXPECTED THROUGH THESE
PERIODS. MODEL TEMP PROFILES SHOW GOOD MIXING HEIGHTS IN THE 830-
800MB RANGE THURSDAY...AND THIS WILL HELP MIX STRONGER WINDS TO THE
SURFACE AIDED BY UNIDIRECTIONAL GRADIENT THROUGH 500MB. THIS WOULD
SUPPORT GUSTS IN THE 35-45 MPH RANGE (ASSUMING INCREASING CIRRUS
DOESNT COMPLICATE THINGS FOR US).
HIGH TEMPERATURES TODAY AND THURSDAY WILL BE MUCH ABOVE NORMAL WITH
RECORD HIGHS LIKELY ACROSS OUR CWA ON THURSDAY. LATEST STATISTICAL
GUIDANCE HAS TRENDED A LITTLE WARMER ON HIGHS BOTH DAYS. BASED ON
BIAS CORRECTED 2M TEMPS AND STANDARD BIAS OFF 925MB/850MB TEMPS
ALOFT HIGHS TODAY COULD BE NEAR 70F...AND IN THE LOW TO MID 80S AT
SOME LOCATIONS THURSDAY. A FEW MONTHLY RECORDS COULD BE IN PLAY FOR
THURSDAY. LOW TEMPERATURES WILL ALSO BE UNSEASONABLY HIGH TONIGHT
AND THURSDAY NIGHT...PARTICULARLY THURSDAY NIGHT WHERE WINDY
CONDITIONS WILL KEEP CONDITIONS WELL MIXED DESPITE CAA BEHIND
FROPA. IN FACT WE MAY BE LOOKING AT RECORD HIGH MINS BOTH NIGHTS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 208 AM MST WED FEB 17 2016
FOR THE EXTENDED PERIOD...THE TRI STATE REGION WILL CONTINUE TO SEE
MAINLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. MID LEVEL FLOW
AT 500MB WILL REMAIN ZONAL THRU THE UPCOMING WEEKEND WITH ANOTHER
BROAD UPPER RIDGE BUILDING ON THE WEST COAST BY THE BEGINNING OF
NEXT WEEK...THEN SHIFTING EASTWARD INTO THE ROCKIES BY MIDWEEK NEXT
WEEK.
BY MONDAY NIGHT...MODELS CONTINUE TO SHOW WEAK SHORTWAVE MOVE SE
ALONG THE EAST SIDE OF THE UPPER RIDGE...THRU EASTERN COLORADO
THEN QUICKLY SOUTH OF THE CWA GOING INTO TUESDAY. BASED ON
CURRENT TRACK...MOST OF THE QPF WILL AVOID THE REGION...LEAVING
ONLY A SLIGHT CHANCE FOR LIGHT RAIN.
WARMEST TIME FRAME IN THE EXTENDED WILL OCCUR ON SATURDAY WITH
WESTERLY ZONAL DOWNSLOPE FLOW OVER THE AREA. LOOKING FOR 60S ON
THAT DAY...WITH A DOWNTREND INTO THE 50S SUNDAY AND MONDAY AS
WINDS SHIFT TO MORE NW ALLOWING FOR COLDER AIR TO FILTER INTO THE
REGION. FOR TUESDAY INTO WEDNESDAY...WITH THE PASSAGE OF THE WEAK
SHORTWAVE...HIGHS WILL ONLY REACH INTO THE U40S TUESDAY WITH NLY A
REBOUND TO AROUND 50F FOR WEDNESDAY. OVERNIGHT LOWS WILL START OFF
INTO THE LOWER 30S SATURDAY NIGHT...W/ 20S FOR THE REMAINDER OF
THE OVERNIGHT PERIODS INTO MIDWEEK NEXT WEEK. SATURDAY THRU MONDAY
WILL END UP HAVING ABOVE NORMAL CONDITIONS...WHILE OVERALL FOR
TUESDAY AND WEDNESDAY...NEAR NORMAL WITH THE ADDITION OF COLDER
AIR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1020 PM MST TUE FEB 16 2016
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WEST TO SOUTHWEST
WINDS IN THE 6 TO 11 KNOT RANGE WILL SHIFT TO THE SOUTH TO
SOUTHEAST DURING THE AFTERNOON HOURS. THE WINDS AT KGLD COULD
GUST TO NEAR 21 KNOTS IN THE AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MST WED FEB 17 2016
MODELS SHOW INCREASING CIRRUS AHEAD OF APPROACHING
TROUGH ON THURSDAY WHICH COULD COMPLICATE MIXING HEIGHTS...HOWEVER
EVEN THEN IT APPEARS HIGHLY LIKELY THAT THE STRONG GRADIENT IN
PLACE OVER OUR CWA WILL STILL SUPPORT RED FLAG CRITERIA WINDS.
FUELS CONTINUE TO BE A QUESTION NORTH OF THE CURRENT WATCH DESPITE
LIKELIHOOD OF RH/WIND CRITERIA DUE TO IMPACTS OF RECENT SNOW MELT.
THIS MAY NOT HAVE AS MUCH OF AN IMPACT ON ONE HOUR FUELS OR
POTENTIAL FOR LARGE GRASS FIRES IN THE FORECAST
CONDITIONS...PARTICULARLY SINCE WE HAVE HAD SEVERAL VERY MILD/DRY
DAYS (AND ANOTHER TODAY). NO CHANGES TO FIRE WEATHER WATCH DURING
THIS UPDATE CYCLE TO ALLOW DAY SHIFT TO COORDINATE FUEL CONDITIONS
WITH OUR FIRE WEATHER PARTNERS.
&&
.CLIMATE...
ISSUED AT 300 AM MST WED FEB 17 2016
RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY.
SITE.............DAILY RECORD...CURRENT FORECAST
GOODLAND, KS.........74...............79
MCCOOK, NE...........82...............76
BURLINGTON,CO........74...............79
HILL CITY,KS.........75...............82
COLBY, KS............81...............79
TRIBUNE, KS..........79...............81
YUMA, CO.............73...............75
CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS...
GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS)
MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS)
BURLINGTON...82 (02-11-1962)
HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS)
COLBY........83 (02-12-1911)
TRIBUNE......81 (02-20-1981)
YUMA.........79 (02-12-1962 AND PREVIOUS YEARS)
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR KSZ027>029-041-042.
CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR COZ254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...BULLER
FIRE WEATHER...DR
CLIMATE...DR
Area Forecast Discussion
National Weather Service Louisville KY
910 AM EST WED FEB 17 2016
...Forecast Update...
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations
atthis hour. These are occurring mainly across central KY and
shouldpersist until late morning. Observed visibilities are also
backed upby the latest HRRR visibility data. So, issued a Special
WeatherStatement until 11 AM EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (12Z TAF Update)...
Updated at 630 AM EST Wed Feb 17 2016
Poor flying conditions this hour, with lots of low-level moisture
making for low cigs and some patches of dense fog as well. The worst
of the fog still is roughly between KSDF and KBWG, but some remains
over KLEX. Expect these poor conditions to last most of the morning,
though SDF has the best chance to break out of it, with slightly
drier air working in from the north. GOES-R MVFR product also has a
gap of VFR conditions just over southern Indiana, but that gap is
not making any quick inroads toward SDF this hour. Have gone with
cigs up to low-end MVFR in the afternoon hours, assuming some
daytime heating allows for better mixing near the surface. For the
outlook period, guidance is calling for cigs to improve in the
evening. Not sold on that idea yet, cause if cigs improve we may
drop vsby`s back down anyway. Will keep MVFR most of the night for
now.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......RJS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
532 AM CST WED FEB 17 2016
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED FEB 17 2016
TODAY AND TONIGHT...SFC LOW PRESSURE ACROSS THE NRN HIGH PLAINS WILL
DEEPEN FROM 1010 MB AT 09Z THIS MORNING TO 998 MB BY 00Z THIS
EVENING. SOUTH WINDS DEVELOPING THIS AFTN INCREASE TO AROUND 10 TO
15 MPH. THE MODEL CONSENSUS INDICATES GENERALLY CLEAR SKIES.
H850MB TEMPERATURES RISE TO 7C TO 14C BY 00Z THIS EVENING. THE
WARMEST THREE BLENDED GUIDANCE DATA SETS PLUS BIAS CORRECTION
SUGGESTS HIGHS IN THE 50S TO LOWER 60S. THIS IS CLOSE TO THE RAP
MODEL BUT STILL COOL BY A DEGREE OR TWO. THE MET GUIDANCE WAS TOO
COOL FOR THIS FORECAST LEAVING THE EKD...THE MAV AND ECS AS DRIVERS
FOR HIGHS TODAY.
H850MB TEMPERATURES RISE TO 12C TO 15C TONIGHT AS THE THERMAL RIDGE
STRENGTHENS. SOUTH WINDS INCREASE TO 10 TO 20 MPH WITH LOWS IN THE
30S TO AROUND 40. A POCKET OF FREEZING TEMPS DEVELOP IN THE PLATTE
VALLEY WHERE WINDS DECOUPLE TOWARD MORNING. THIS FORECAST USES A
BLEND OF THE DETERMINISTIC MODELS PLUS BIAS CORRECTION AND PRODUCES
A FORECAST ABOUT 1 DEGREE WARMER THAN A BLEND OF GUIDANCE PLUS BIAS
CORRECTION.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED FEB 17 2016
MID RANGE...THURSDAY AND FRIDAY...MAIN FORECAST CHALLENGES ARE
TEMPERATURES AND WIND. VERY STRONG WAA AHEAD OF A SURFACE FRONT...
1.5 PVU ANOMALY...AND 130+KT 250HPA JET THURSDAY. ALL MODELS SHOW
850HPA TEMPS RISING FROM NEAR 8C AT 00Z THU TO NEAR 18C AT 18Z. THE
ECM AND GFS ARE EVEN SHOWING 20C NEAR KIML. GOOD DOWNSLOPE SETUP
WITH WEST/SOUTHWEST LOW LEVEL WINDS THU AFTERNOON. GFS FORECAST
SOUNDINGS INDICATE DEEP MIXING WITH STEEP LAPSE RATES AND NEARLY
UNIDIRECTIONAL WINDS TO 600HPA...ESPECIALLY THE WESTERN HALF OF
FORECAST AREA. WITH PARTLY TO MOSTLY FAIR SKIES...NOT EXPECTING MUCH
HINDERING OF THE MIXING. ADJUSTED DEW POINTS DOWN AND SFC WINDS UP
AS MODELS OFTEN UNDERESTIMATE STRONG DOWNSLOPE EVENTS. BUMPED UP MAX
TEMPS A DEGREE...WHICH STILL UNDERCUTS MAV GUIDANCE BY 5F BUT
TIES/BREAKS DAILY RECORDS AT KIML AND KVTN AND PUTS WITHIN 2 DEGREES
AT KLBF. REMOVED SCHC POPS ACROSS THE NORTH LATE THURSDAY AS THE
BULK OF THE MOISTURE APPEARS TO STAY IN SDAK. NAM AND GFS FORECAST
SOUNDINGS SHOW WHAT WILL LIKELY BE TOO MUCH DRY AIR IN THE LOW AND
MID LEVELS AT MERRIMAN...KVTN...AND KONL. IF ANY PRECIP DOES
OCCUR...IT WOULD FALL AS VERY LIGHT RAIN FOR A BRIEF PERIOD
OVERNIGHT. DID NOT TWEAK MIN TEMPS MUCH AS THE TIMING OF THE
STRONGEST WINDS...GENERALLY 6-12Z...WOULD PREVENT BOUNDARY LAYER
DECOUPLING. ECM...NAM...AND GFS SHOW 850HPA WINDS OF 50-60
KTS...WHICH COULD EASILY TRANSLATE TO GUSTS OF AT LEAST 40-45 KTS AT
THE SFC. HELD OFF ON ANY WIND HEADLINES AS THE EVENT IS 48 HOURS
AWAY...UNCERTAINTY REMAINS IN THE MAGNITUDE OF THE WIND...AND THE
WINDOW OF POSSIBLY CRITERIA SPEEDS WOULD BE RELATIVELY SHORT.
FRIDAY...ALMOST A REPEAT SCENARIO WITH FAIR CONDITIONS AND
DOWNSLOPING WINDS...SO RAISED MAX TEMPS A DEGREE. MODELS CONSISTENT
WITH 850HPA TEMPS 6-8C COOLER THUS HIGHS IN THE 60S INSTEAD OF 70S.
LONG RANGE...SATURDAY TO TUESDAY...ZONAL FLOW AT 500HPA SLOWLY
TRANSITIONS TO NORTHWEST FLOW AS A RIDGE AMPLIFIES OVER THE
INTERMOUNTAIN WEST. TEMPERATURES REMAIN MILD SATURDAY BUT COOL
SLIGHTLY SUNDAY BEHIND A SHORTWAVE AND MONDAY WITH A CLIPPER SYSTEM.
850HPA TEMPS AROUND 0C DURING THE DAY...MAKING HIGHS IN THE UPPER
40S. QUICK SHOT OF MOISTURE MONDAY NIGHT...BUT NOT EXPECTING MUCH IN
TERMS OF ACCUMULATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 530 AM CST WED FEB 17 2016
VFR IS EXPECTED ALL AREAS TODAY AND TONIGHT WITH ONE CAVEAT. THE
IFR/LIFR CIGS ACROSS SD/NERN NEB COULD BACK INTO BOYD AND HOLT
COUNTIES TONIGHT FOR A FEW HOURS AS A RESULT OF DEEPENING LOW
PRESSURE ACROSS MT. THE RAP SUGGESTS THIS IS POSSIBLE AND LATER
FORECASTS WILL REVEAL THE POTENTIAL FOR LOW CIGS AT KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...SNIVELY
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
950 AM CST WED FEB 17 2016
.UPDATE...
ISSUED AT 945 AM CST WED FEB 17 2016
NO MAJOR CHANGES WERE NEEDED FOR THIS FORECAST UPDATE. DID EXTEND
PATCHY FOG OVER PARTS OF WESTERN AND CENTRAL NORTH DAKOTA UNTIL 18
UTC...BASED ON CURRENT OBSERVATIONS AND LATEST HRRR ITERATIONS.
UPDATE ISSUED AT 628 AM CST WED FEB 17 2016
NO SIGNIFICANT UPDATES EARLY THIS MORNING. BISMARCK 12 UTC
SOUNDING INDICATES POTENTIAL FOR FREEZING DRIZZLE. RADAR SHOWS
SOME VERY LIGHT REFLECTIVITIES OVER CENTRAL NORTH DAKOTA. ALTHOUGH
NOTHING REPORTED AS OF YET AND NO GROUND TRUTH...WILL KEEP A
MENTION OF FREEZING DRIZZLE ACROSS THE CENTRAL THIS MORNING. AREAS
OF FOG CONTINUE IN THE WEST AND PORTIONS OF THE CENTRAL A FEW
LOCALES DOWN TO A QUARTER MILE AND HAVE EXTENDED THE SPS FOR AREAS
OF DENSE FOG THROUGH 14 UTC.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CST WED FEB 17 2016
THE MAIN CONCERN IN THE SHORT TERM IS THE CONTINUED MOIST LOW LEVEL
REGIME THAT IS PROGGED TO REMAIN OVER THE STATE TODAY AND
TONIGHT...WITH AREAS OF FOG AND LINGERING LIGHT SNOW AND POTENTIAL
FOR FREEZING DRIZZLE.
CURRENTLY...COLD SURFACE HIGH PRESSURE WAS CENTERED OVER THE BORDER
OF NORTHERN MINNESOTA/MANITOBA/ONTARIO WITH A SOUTHEAST SURFACE FLOW
ACROSS THE DAKOTAS INTO SASKATCHEWAN AND WESTERN MANITOBA. MEANWHILE
A MILD PACIFIC HIGH WAS IN THE LEE OF THE ROCKIES OVER WESTERN
MONTANA/WYOMING/COLORADO. BETWEEN THE TWO HIGH PRESSURE SYSTEMS WAS
A LARGE AREA OF LOW LEVEL STRATUS EXTENDING FROM EASTERN SOUTH
DAKOTA ACROSS NORTH DAKOTA AND INTO SASKATCHEWAN/MANITOBA. AT UPPER
LEVELS...A WESTERN RIDGE WAS OVER THE ROCKIES WITH A TROUGH FROM
HUDSON BAY SOUTH ACROSS THE GREAT LAKES AND OHIO VALLEY.
REGIONAL RADARS INDICATE THE AREAS OF LIGHT SNOW AND PERHAPS SOME
ISOLATED PATCHES OF FREEZING DRIZZLE WERE DIMINISHING OVER THE PAST
COUPLE OF HOURS. CHANCES OF LIGHT PRECIPITATION EARLY THIS MORNING
WILL DIMINISH WITH TIME THIS MORNING. WILL KEEP THE MENTION OF AREAS
OF FOG ACROSS THE WEST HALF OF THE STATE EARLY THIS MORNING.
TODAY AND TONIGHT THE UPPER LEVEL RIDGE IS FORECAST TO BEGIN MOVING
EASTWARD...AND A DRY WESTERLY/SOUTHWESTERLY FLOW ALOFT SHOULD BEGIN
MOVING OVER THE COOL AND MOIST SURFACE AIRMASS. THE INITIAL WESTERLY
FLOW OF DRY AIR SHOULD BEGIN IN SOUTHWESTERN NORTH DAKOTA AFTER
DAYBREAK THIS MORNING AND PUSH INTO CENTRAL NORTH DAKOTA BY
AFTERNOON...AND REACH EASTERN NORTH DAKOTA THIS EVENING. THE DRY
SOUTHWESTERLY FLOW ALOFT CONTINUES THROUGH TONIGHT AND STRENGTHENS
WITH INCREASED H850 WINDS. HOWEVER...THE MOIST SOUTHEASTERLY SURFACE
FLOW CONTINUES TODAY AND TONIGHT. THUS THE DEEP COOL AND MOIST LAYER
OVER THE STATE THIS MORNING BEGINS TO ERODE FROM MID LEVELS DOWN
TOWARDS THE SURFACE WITH TIME. THERE IS A HINT THAT SOME LOW LEVEL
MOISTURE WILL FINALLY ERODE FROM FAR SOUTHWESTERN NORTH DAKOTA THIS
AFTERNOON (HENCE THE FORECAST HIGHS IN THE 50S FAR SOUTHWEST)...BUT
THE SOUTHEASTERLY SURFACE FLOW DOMINATES AND THE MODELS ARE
FORECASTING THE LOW LEVEL MOISTURE/STRATUS TO EXPAND BACK WESTWARD
ACROSS WESTERN NORTH DAKOTA TONIGHT.
THE RESULT WILL BE LOW CLOUDS OVER MOST OF THE STATE TODAY...WITH A
BREAK IN THE LOW CLOUDS SOUTHWEST THIS AFTERNOON...THEN LOW CLOUDS
AND STRATUS DOMINATING AGAIN TONIGHT. THERE SHOULD BE A LARGE
CONTRAST IN HIGH TEMPERATURES TODAY...WITH 50S IN THE SOUTHWEST
BUT 30S OVER THE NORTHWEST AND CENTRAL UNDER THE INFLUENCE OF THE
STRATUS CLOUDS.
THE STRONG WARMING AND DRYING ALOFT TONIGHT COMBINED WITH A
REINFORCED MOIST SOUTHEASTERLY SURFACE FLOW WILL RESULT IN A
SUPERCOOLED SURFACE BOUNDARY LAYER THAT WOULD SUPPORT DRIZZLE.
TEMPERATURES TONIGHT ARE FORECAST TO BE IN THE MID TO UPPER 20S OVER
CENTRAL NORTH DAKOTA...THUS THERE IS A POTENTIAL FOR AREAS OF FOG
AND THE POTENTIAL FOR FREEZING DRIZZLE OVER CENTRAL NORTH DAKOTA
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 319 AM CST WED FEB 17 2016
THE MAIN FORECAST ISSUE IN THE LONG TERM PERIOD IS PRECIPITATION
CHANCES AND TYPES THURSDAY AND THURSDAY NIGHT...THEN WINDS ON
FRIDAY.
A PROGRESSIVE FLOW PATTERN AND SEASONABLY WARM TEMPERATURES WILL
RESULT IN A SERIES OF SYSTEMS WITH MIXED PRECIPITATION AND PERIODIC
WINDY PERIODS.
WE BEGIN THE LONG TERM PERIOD ON THURSDAY WITH AN UPPER LEVEL TROUGH
MOVING ONTO THE PACIFIC NORTHWEST COAST. DOWNSTREAM...UPPER LEVEL
RIDGING AND STRONG WARM ADVECTION IS PUSHING FROM EASTERN MONTANA
INTO THE WESTERN DAKOTAS. FARTHER EAST OVER CENTRAL NORTH DAKOTA
SOUTHEAST SURFACE FLOW IS KEEPING ABUNDANT LOW LEVEL MOISTURE NEAR
THE SURFACE WITH WARM ADVECTION AND WEAK SHORTWAVE ENERGY ALOFT.
WILL KEEP A MENTION OF FREEZING DRIZZLE THROUGH MID-MORNING IN THE
SOUTH CENTRAL AND THROUGH THE MORNING NORTH CENTRAL AS TEMPERATURES
REMAIN BELOW FREEZING HERE. ALSO KEPT A MENTION OF FOG THROUGH MID
MORNING ACROSS THE FORECAST AREA.
STRONG WARM ADVECTION PUSHES INTO WESTERN NORTH DAKOTA DURING THE
DAY AND SHOULD CLEAR THE LOW CLOUDS AT LEAST OVER THE SOUTHWEST
PORTION OF THE STATE...THUS TEMPERATURES IN THE UPPER 50S ARE
EXPECTED...WITH A STRONG GRADIENT TO MID 30S OVER THE NORTHEAST CWA.
WARM FRONT AND ASSOCIATED SURFACE LOW PRESSURE MOVE ACROSS WESTERN
AND CENTRAL NORTH DAKOTA THURSDAY NIGHT AS THE UPPER LEVEL WAVE
MOVES ACROSS THE NORTHERN/CENTRAL ROCKIES AND INTO THE PLAINS.
MODELS ARE STILL NOT IN GREAT AGREEMENT IN RESULTANT QPF PATTERN.
THE GFS AND GEM ARE LIGHTER WITH THE QPF MOVING THROUGH THE FORECAST
AREA THURSDAY NIGHT AND KEEP HIGHER QPF AMOUNTS ALONG AND NORTH OF
THE CANADIAN BORDER. THE NAM/ECMWF BRING A MORE WIDESPREAD AREA OF
QPF ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ALTHOUGH THE NAM GETS
TOO AGGRESSIVE WITH THE QPF. FOR NOW A BLEND SEEMS REASONABLE WITH A
PRECIPITATION PATTERN SIMILAR TO THE ECMWF BUT TONED DOWN A LITTLE.
THIS WOULD BRING THE BULK OF THE PRECIPITATION INTO THE WEST DURING
THE EVENING AND SPREADING ACROSS CENTRAL NORTH DAKOTA AFTER
MIDNIGHT. WE STILL HAVE A MENTION OF FREEZING RAIN AND SLEET OVER
THE NORTH CENTRAL AND INTO THE NORTHERN JAMES RIVER VALLEY AND THIS
SEEMS REASONABLE LOOKING AT BUFKIT SOUNDINGS. BUT BUFKIT SOUNDINGS
ALSO SUGGEST THAT SURFACE TEMPERATURES RISE ENOUGH WITH THE WARM
ADVECTION THURSDAY NIGHT THAT MOST PRECIPITATION MAY FALL AS RAIN.
WILL CERTAINLY NEED TO MONITOR AND CERTAINLY NOT CONFIDENT ENOUGH TO
PULL MENTION OF SLEET AND FREEZING RAIN...ESPECIALLY ACROSS THE
NORTH CENTRAL INTO THE JAMES RIVER VALLEY...BUT FOR POINTS WEST OF
HERE IT LOOKS LIKE MAINLY RAIN. WE DID UTILIZE A BLEND OF RAW MODEL
DATA FOR FORECAST LOWS THURSDAY NIGHT AS SUPERBLEND GUIDANCE WAS TOO
COLD.
ONCE THE SURFACE LOW MOVES THROUGH THE FORECAST AREA STRONG WESTERLY
WINDS DEVELOP. BOUNDARY LAYER WINDS THROUGH THE DAY REMAIN FROM
35 TO 45 KNOTS ACROSS MOST OF THE CWA. THUS IF CONDITIONS HOLD
WOULD EXPECT WIND ADVISORY ACROSS THE CWA...WITH THE POTENTIAL FOR
HIGH WIND WARNING POSSIBLY IN THE SOUTHWEST.
FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR
ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER
SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST
PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY
THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY
NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO NORTHWEST
WIND OF 20 TO 30 MPH. ANOTHER WEAK WAVE MOVES THROUGH MONDAY
BRINGING SMALL CHANCES OF LIGHT SNOW AND COOLER TEMPERATURES
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 628 AM CST WED FEB 17 2016
AT 6 AM CST...A FRONTAL BOUNDARY EXTENDED ACROSS EASTERN
MONTANA...THE FAR SOUTHWEST CORNER OF NORTH DAKOTA...AND INTO
WESTERN SOUTH DAKOTA...SEPARATING MILD AIR TO THE WEST FROM COOLER
AIR EAST. MAINLY IFR CIGS THIS MORNING KISN/KMOT/KDIK/KBIS
WITH IFR TO MVFR VSBYS AT TIMES IN FOG. MVFR AT KJMS. CONDITIONS
GRADUALLY IMPROVING TO VFR AROUND 18Z AT KDIK/KISN AND IMPROVING TO
MVFR AT KBIS/KMOT THIS AFTERNOON. CIGS DETERIORATE AFT 00Z TO
MVFR/IFR WITH CONTINUED LOW LEVEL STRATUS. WEST WIND FLOW ABOVE/OVER
THE COLD MOIST SOUTHEASTERLY SURFACE FLOW WILL BRING A CHANCE OF
FOG/FREEZING DRIZZLE AGAIN WEDNESDAY NIGHT...BUT CONFIDENCE IS LOW
AND NOT MENTIONED IN TAFS AT THE END OF THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ZH
SHORT TERM...JV
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
750 AM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS CENTRAL PA
TODAY...BRINGING OCCASIONAL SNOW SHOWERS TO THE NORTHERN AND
WESTERN MOUNTAINS OF PENNSYLVANIA. HIGH PRESSURE WILL FOLLOW FOR
THURSDAY WITH MORE IN THE WAY OF SUNSHINE...BUT COLDER
TEMPERATURES AVERAGING SOME 5 TO 8 DEGREES BELOW NORMAL.
LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT
LAKES FRIDAY INTO SATURDAY...ACCOMPANIED BY A FEW RAIN OR SNOW
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SHORTWAVE AND OROGRAPHIC LIFT OF THE SHALLOW COLD AIRMASS AND
LIMITED MOISTURE OFF THE GLAKES WAS RESULTING IN SOME VERY LIGHT
FLURRIES (AND A FEW BRIEF INSTANCES OF PATCHY FREEZING DRIZZLE
NEAR AND TO THE WEST OF ROUTE 219 ACROSS THE LAURELS - INVOF KJST).
SKIES WILL STAY OVERCAST THROUGH THE MID MORNING HOURS TODAY WITH
A 5-8 KT WNW SFC WIND AND TEMPS IN THE 20S ACROSS THE NRN AND
WESTERN MTNS...WITH 30S ELSEWHERE.
A COLD FRONT WILL SWING SE ACROSS THE REGION TODAY BRINGING AN
INCREASING CHC OF SNOW SHOWERS AND SOME LIGHT ACCUMS OF A COATING
TO AROUND ONE INCH ACROSS THE NRN MTNS (BEGINNING DURING THE MID
TO LATE MORNING HOURS) AND EVENTUALLY OVER THE LAUREL LATE THIS
MORNING AND THIS AFTERNOON.
MDL DATA INDICATES THE PARENT SHORTWAVE WEAKENS AND SCOOTS BY TO
THE NORTH OF PA TODAY. HOWEVER...A BKN BAND OF -SHSN IS FORECAST
TO SLIDE ACROSS THE NW MTNS BTWN 12Z-15Z. VSBYS IN THIS LIKELY
WEAKENING NORTH/SOUTH SNOW BAND SHOULD BE GENERALLY IN THE 2-4SM
RANGE.
THE LATEST VERSIONS OF THE HRRR /09Z/ AND THE 03Z SREF APPEAR TO
DISSOLVE THIS INITIAL BAND OF SNOW ACROSS THE NW MTNS EARLY
TODAY...AND BRING THE BEST CHC OF SNOW SHOWERS ACROSS THE NW
MTNS...AND LAURELS AFTER 19Z/21Z RESPECTIVELY.
ELSEWHERE...DOWNSLOPING WESTERLY WIND...A LOW SUBSIDENCE INVERSION
BASE AND RELATIVELY WARM STRATO CU CLOUD LAYER...SHOULD LIMIT
PRECIP TO SCT FLURRIES THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION OF THE STATE.
SKIES DURING THE MIDDAY AND AFTERNOON HOURS...ARE EXPECTED TO
RANGE FROM CLOUDY ACROSS THE W MTNS...TO PTSUNNY OVR THE LOWER
SUSQ VALLEY. MDL 8H TEMPS ARND 8C SHOULD TRANSLATE TO MAX TEMPS
FROM THE L30S ACROSS THE ALLEGHENY PLATEAU...TO THE L40S OVR THE
SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
CHILLY HIGH PRESSURE WILL BUILD INTO THE REGION FOR TONIGHT AND
THURSDAY WITH VERY DRY AIR REFLECTED BY DEWPOINTS IN THE SINGLE
DIGITS TO LOWER TEENS...AND GENERALLY JUST SOME SCATTERED PANCAKE
STRATO CU DRIFTING SE ACROSS THE REGION.
LOWS TONIGHT UNDER GRADUALLY DECREASING CLOUD COVER...WILL RANGE
FROM THE SINGLE DIGITS ACROSS THE NW MTNS...TO AROUND 20F
THROUGHOUT THE LOWER SUSQ VALLEY.
HIGHS THURSDAY IN THE MID TO UPPER 20S ACROSS THE MTNS...AND LOWER
TO MID 30S IN THE SUSQ VALLEY...WILL AVERAGE 5-8 DEG F BELOW
NORMAL
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LOOKING AT A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR
LATE IN THE WEEK.
MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON
POPS WHERE POSSIBLE. ONLY A FEW RAIN SHOWERS IF THAT.
COLDER AIR WORKS BACK IN AFTER THE WEEKEND.
00Z EC AND GEFS ARE IN FAIRLY GOOD AGREEMENT WITH SHARP
AMPLIFICATION OF THE UPPER AIR FLOW ACROSS THE CONUS DURING THE
EARLY TO MIDWEEK PERIOD NEXT WEEK.
HIGH AMPLITUDE RIDGE ACROSS IDAHO AND THE REST OF THE
INTERMOUNTAIN WEST IS THE IDEAL LOCATION FOR DOWNSTREAM ENERGY TO
DIG INTO THE BASE OF AN EASTERN U.S. TROUGH AND TRIGGER COASTAL
LOW DEVELOPMENT AND STRENGTHENING.
OPERATIONAL EC AND GEFS BOTH SHOW SFC CYCLOGENESIS OVER THE NRN
GOMEX TUESDAY...THEN A GENERAL TRACK AND DEEPENING OF A SFC LOW NE
ALONG THE CAROLINA AND MID ATLANTIC COAST BY WED NIGHT. PLAN TO
INCREASE POPS FOR THE TUESDAY-WED NIGHT PERIOD WITH THE NEXT...12Z
GRIDDED DATA/ZONE PACKAGE.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
SHORTWAVE SLIDING SW-NE OVERHEAD NOW SHORTLY AFTER SUNRISE
KEEPING IFR RESTRICTIONS IN PLACE OVER WESTERN AREAS...WHILE MVFR
CIGS HAVE SPREAD ACROSS MUCH OF REMAINDER OF CWA. AS THIS LIFTS
NE...CIGS WILL IMPROVE TO VFR OVER THE EAST.
TROUGH FOLLOWS FOR TODAY...AS RESTRICTIONS WILL CONTINUE MAINLY
OVER WESTERN HIGHER TERRAIN AS LIGHT SNOW SHOWERS DEVELOP. THE
MVFR CIGS MAY LINGER IN THE CENTRAL MTNS INTO EARLY/MID
AFTERNOON... BUT OTHERWISE CENTRAL AND SE WILL REMAIN VFR.
HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW
PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES
FRIDAY INTO SATURDAY.
OUTLOOK...
THU...MAINLY VFR.
FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE.
SAT-SUN...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
538 AM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST ACROSS CENTRAL PA
TODAY...BRINGING OCCASIONAL SNOW SHOWERS TO THE NORTHERN AND
WESTERN MOUNTAINS OF PENNSYLVANIA. HIGH PRESSURE WILL FOLLOW FOR
THURSDAY WITH MORE IN THE WAY OF SUNSHINE...BUT COLDER
TEMPERATURES AVERAGING SOME 5 TO 8 DEGREES BELOW NORMAL.
LOW PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT
LAKES FRIDAY INTO SATURDAY...ACCOMPANIED BY A FEW RAIN OR SNOW
SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK SHORTWAVE AND OROGRAPHIC LIFT OF THE SHALLOW COLD AIRMASS AND
LIMITED MOISTURE OFF THE GLAKES WAS RESULTING IN SOME VERY LIGHT
FLURRIES (AND A FEW BRIEF INSTANCES OF PATCHY FREEZING DRIZZLE
NEAR AND TO THE WEST OF ROUTE 219 ACROSS THE LAURELS - INVOF KJST).
SKIES WILL STAY OVERCAST THROUGH THE MID MORNING HOURS TODAY WITH
A 5-8 KT WNW SFC WIND AND TEMPS IN THE 20S ACROSS THE NRN AND
WESTERN MTNS...WITH 30S ELSEWHERE.
A COLD FRONT WILL SWING SE ACROSS THE REGION TODAY BRINGING AN
INCREASING CHC OF SNOW SHOWERS AND SOME LIGHT ACCUMS OF A COATING
TO AROUND ONE INCH ACROSS THE NRN MTNS (BEGINNING DURING THE MID
TO LATE MORNING HOURS) AND EVENTUALLY OVER THE LAUREL LATE THIS
MORNING AND THIS AFTERNOON.
MDL DATA INDICATES THE PARENT SHORTWAVE WEAKENS AND SCOOTS BY TO
THE NORTH OF PA TODAY. HOWEVER...A BKN BAND OF -SHSN IS FORECAST
TO SLIDE ACROSS THE NW MTNS BTWN 12Z-15Z. VSBYS IN THIS LIKELY
WEAKENING NORTH/SOUTH SNOW BAND SHOULD BE GENERALLY IN THE 2-4SM
RANGE.
THE LATEST VERSIONS OF THE HRRR /09Z/ AND THE 03Z SREF APPEAR TO
DISSOLVE THIS INITIAL BAND OF SNOW ACROSS THE NW MTNS EARLY
TODAY...AND BRING THE BEST CHC OF SNOW SHOWERS ACROSS THE NW
MTNS...AND LAURELS AFTER 19Z/21Z RESPECTIVELY.
ELSEWHERE...DOWNSLOPING WESTERLY WIND...A LOW SUBSIDENCE INVERSION
BASE AND RELATIVELY WARM STRATO CU CLOUD LAYER...SHOULD LIMIT
PRECIP TO SCT FLURRIES THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION OF THE STATE.
SKIES DURING THE MIDDAY AND AFTERNOON HOURS...ARE EXPECTED TO
RANGE FROM CLOUDY ACROSS THE W MTNS...TO PTSUNNY OVR THE LOWER
SUSQ VALLEY. MDL 8H TEMPS ARND 8C SHOULD TRANSLATE TO MAX TEMPS
FROM THE L30S ACROSS THE ALLEGHENY PLATEAU...TO THE L40S OVR THE
SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
CHILLY HIGH PRESSURE WILL BUILD INTO THE REGION FOR TONIGHT AND
THURSDAY WITH VERY DRY AIR REFLECTED BY DEWPOINTS IN THE SINGLE
DIGITS TO LOWER TEENS...AND GENERALLY JUST SOME SCATTERED PANCAKE
STRATO CU DRIFTING SE ACROSS THE REGION.
LOWS TONIGHT UNDER GRADUALLY DECREASING CLOUD COVER...WILL RANGE
FROM THE SINGLE DIGITS ACROSS THE NW MTNS...TO AROUND 20F
THROUGHOUT THE LOWER SUSQ VALLEY.
HIGHS THURSDAY IN THE MID TO UPPER 20S ACROSS THE MTNS...AND LOWER
TO MID 30S IN THE SUSQ VALLEY...WILL AVERAGE 5-8 DEG F BELOW
NORMAL
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
LOOKING AT A SW FLOW OF MILD AND DRY AIR OFF THE HIGH PLAINS FOR
LATE IN THE WEEK.
MOISTURE IS LIMITED WITH THIS AIRMASS...SO DID CUT BACK ON
POPS WHERE POSSIBLE. ONLY A FEW RAIN SHOWERS IF THAT.
COLDER AIR WORKS BACK IN AFTER THE WEEKEND.
00Z EC AND GEFS ARE IN FAIRLY GOOD AGREEMENT WITH SHARP
AMPLIFICATION OF THE UPPER AIR FLOW ACROSS THE CONUS DURING THE
EARLY TO MIDWEEK PERIOD NEXT WEEK.
HIGH AMPLITUDE RIDGE ACROSS IDAHO AND THE REST OF THE
INTERMOUNTAIN WEST IS THE IDEAL LOCATION FOR DOWNSTREAM ENERGY TO
DIG INTO THE BASE OF AN EASTERN U.S. TROUGH AND TRIGGER COASTAL
LOW DEVELOPMENT AND STRENGTHENING.
OPERATIONAL EC AND GEFS BOTH SHOW SFC CYCLOGENESIS OVER THE NRN
GOMEX TUESDAY...THEN A GENERAL TRACK AND DEEPENING OF A SFC LOW NE
ALONG THE CAROLINA AND MID ATLANTIC COAST BY WED NIGHT. PLAN TO
INCREASE POPS FOR THE TUESDAY-WED NIGHT PERIOD WITH THE NEXT...12Z
GRIDDED DATA/ZONE PACKAGE.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
SHORTWAVE SLIDING SW-NE OVERHEAD EARLY THIS MORNING KEEPING IFR
RESTRICTIONS IN PLACE OVER WESTERN AREAS...WHILE MVFR CIGS SPREAD
ACROSS REMAINDER OF CWA FOR SEVERAL HOURS PRE-DAWN. COULD EVEN BE
A BIT OF PATCHY DZ/FZDZ IN SPOTS.
TROUGH SLIDES THROUGH ON WED...AS RESTRICTIONS CONTINUE MAINLY OVER
WESTERN HIGHER TERRAIN WITH LIGHT SNOW SHOWERS. THEY MAY AGAIN
SPILL INTO THE CENTRAL MTNS FOR A TIME...BUT OTHERWISE CENTRAL AND
SE WILL REMAIN VFR.
HIGH PRESSURE WILL BUILD OVER THE STATE ON THURSDAY...THEN LOW
PRESSURE WILL TRACK NORTH OF PENNSYLVANIA THROUGH THE GREAT LAKES
FRIDAY INTO SATURDAY.
OUTLOOK...
WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE
OVER THE WEST /AND POSS CENTRAL/ ALONG WITH POTENTIAL FOR LIGHT
SNOW.
THU...MAINLY VFR.
FRI...MAINLY VFR. PERHAPS A RAIN SHOWER...MAINLY LATE.
SAT-SUN...MAINLY VFR. A FEW RAIN SHOWERS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LAMBERT/MARTIN
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
955 AM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL CROSS THROUGH THE OHIO VALLEY TODAY AND
TONIGHT...THEN WILL DISSIPATE OVER THE MID ATLANTIC REGION BY
THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND
WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW
PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE
EAST ACROSS THE GREAT LAKES ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 AM EST WEDNESDAY...
SHORTWAVE WILL ROTATE AROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT
NORTHEAST TONIGHT. THE HIRESW-ARW EAST...RNK WRF ARW AND RAP
SUPPORT SNOW SHOWERS AND SNOW FLURRIES IN THE WESTERN MOUNTAINS.
THIS MORNING HRRR IS LESS IMPRESSED WITH SNOW SHOWERS FOR THIS
AFTERNOON COMPARED TO OTHER HIRES SOLUTIONS. WILL MAINTAIN
SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW
ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE
OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY
OF WEST VIRGINIA. ADJUSTED TEMPERATURES WITH LATEST OBS AND MODEL
TRENDS FOR THIS MORNING INTO THIS AFTERNOON. WILL HOLD WITH
CURRENT HIGH TEMPERATURES FOR THIS AFTERNOON...BUT COULD BE A
COUPLE OF DEGREES HIGHER IN SOUTHSIDE WITH SUNSHINE. MORE CHANGES
LATER TODAY...
AS OF 655 AM EST WEDNESDAY...
PRECIPITATION HAS ENDED ACROSS THE FORECAST AREA AND CLOUDS WERE
ALREADY CLEARING OUT EAST OF THE BLUE RIDGE.
NEXT SHORT WAVE WILL ROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON THEN TROF AXIS MOVES EAST AND 500 MB HEIGHTS RISE OVER THE
FORECAST AREA TONIGHT. AT THE SURFACE A WEAK AREA OF LOW PRESSURE
OVER THE CAROLINAS WILL MOVE EAST THIS MORNING. HIGH PRESSURE BUILDS
IN TONIGHT.
LOW LEVEL MOISTURE WITH THE UPSTREAM SHORT WAVE ARRIVE IN THE
MOUNTAINS THIS MORNING. BY MIDNIGHT...ENOUGH DRY AIR COMES IN TO END
THE UPSLOPE SHOWERS AND ON THURSDAY FOR CLEARING IN THE MOUNTAINS.
NO MAJOR ADJUSTMENTS FROM TEMPERATURE GUIDANCE TODAY OR TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 350 AM EST WEDNESDAY...
ANY LINGERING MOUNTAIN SNOW SHOWERS SHOULD BE GONE BY THURSDAY
MORNING...AS HIGH PRESSURE ARRIVES FROM THE NORTHWEST. SOME
LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON
WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE
BLUE RIDGE...IT WILL BE MOSTLY SUNNY SKIES WITH TEMPERATURES
CLIMBING TOWARD THE MID TO UPPER 40S. AS THE HIGH SAGS SOUTHWARD
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE ON THURSDAY NIGHT...CLEAR
SKIES AND CALM WINDS SHOULD ALLOW GOOD RADIATIONAL COOLING TO DROP
LOWS BELOW FREEZING FOR MOST LOCATIONS.
A SOUTH TO SOUTHEAST BREEZE WILL PICK UP DURING FRIDAY...AS THE CWA
ENTERS A ZONE OF WARM AIR ADVECTION WITH HIGH PRESSURE OFFSHORE.
UPPER LEVEL RIDGING SHOULD ALSO TAKE PLACE OVER THE EASTERN UNITED
STATES. ALTHOUGH SOME PASSING CIRRUS CLOUDS MAY DAMPER THE FULL
POTENTIAL OF DIURNAL HEATING...HIGH TEMPERATURES WILL REACH THE MID
40S TO THE MID 50S. BY FRIDAY NIGHT...A PASSING DISTURBANCE MOVING
EASTWARD OVER SOUTHERN ONTARIO IN CANADA MAY LEAVE A TONGUE OF
SHALLOW MOISTURE STRETCHING SOUTHWARD OVER THE APPALACHIAN
MOUNTAINS. WITH LOWS HOLDING ABOVE FREEZING DUE TO CLOUD
COVER...ONLY A CHANCE OF LIGHT RAIN IS ANTICIPATED FOR THE WESTERN
SLOPES. IN ADDITION...SOUTH WINDS SHOULD INCREASE OVERNIGHT ALONG
THE HIGHEST RIDGETOPS...AND COULD POSSIBLY GUST UP TO 30 MPH.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 PM EST TUESDAY
THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE
WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM
THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED
BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR
THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER
THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT
PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. THIS
FRONT WILL STALL OVER THE PIEDMONT AND BECOME A LEE TROUGH. WITH
ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S
AND 60S.
ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH
ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG
THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO
TUESDAY...THE UPPER LEVEL TROUGH WILL MOVE TO THE OHIO VALLEY WHILE
LOW PRESSURE IN THE TENNESSEE VALLEY BUCKLES THE SOUTHERN BOUNDARY
NORTH...LINKING UP WITH THE LEE TROUGH OVER THE PIEDMONT.
THE UPPER LEVEL TROUGH BECOMES NEGATIVE-TILTED WITH CONVECTIVE
SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR
ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST
TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 845 PM EST TUESDAY...
CLOUDS HAVE CLEARED EAST OF THE BLUE RIDGE. AFTER SOME PATCHY FOG
AT KDAN WITH MVFR VISIBILITIES...CONDITIONS WILL BE VFR FOR THE
REST OF THE DAY AND OVERNIGHT AT KDAN...KLYH AND KROA.
NORTHWEST WINDS AND LOW LEVEL MOISTURE WILL BRING MVFR CLOUDS TO
THE MOUNTAINS TODAY AND TONIGHT. UPSLOPE RAIN AND SNOW SHOWERS ARE
EXPECTED THIS AFTERNOON THROUGH EARLY THURSDAY MORNING...BUT ONLY
MEDIUM CONFIDENCE THAT PRECIPITATION WILL IMPACT KLWB OR KBLF.
EXTENDED DISCUSSION...
BY THURSDAY...HIGH PRESSURE WILL MOVE OVERHEAD...AND BRING A
RETURN TO VFR CONDITIONS AT ALL SITES THROUGH FRIDAY. ANOTHER LOW
PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD
SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY
NIGHT AND SATURDAY.
&&
.HYDROLOGY...
AS OF 303 PM EST TUESDAY...
STORM TOTAL PRECIPITATION (2-DAY) IN THE FORM OF SNOW AND RAIN
(MUCH OF IT FREEZING) HAS RANGED GENERALLY FROM 1 TO 2.5 INCHES
WITH UP TO 3+ INCHES ACROSS PORTIONS OF BEDFORD...EASTERN FRANKLIN
AND SOUTHERN BOTETOURT COUNTIES...ALTHOUGH THIS IS RADAR INDICATED
AND NOT WELL CORROBORATED BY RAIN GAGES. WITH MUCH OF THE
OVERNIGHT RAIN FALLING ONTO AND INTO A SUBSTANTIAL SNOWPACK THE
HYDROLOGIC RESPONSE HAS BEEN SOMEWHAT MUTED.
FORECASTS ON THE JAMES HAVE BEEN REDUCED SLIGHTLY FROM YESTERDAY
AND ARE NOW EXPECTING RISES TO BELOW ACTION STAGE WITH THE
EXCEPTION OF SCOTTSVILLE. BOTH THE NEW AND GREENBRIER WILL SEE
VERY MODEST RISES DUE TO THE SNOWPACK ABSORPTION AND ONLY SLOW
MELT OVER COMING DAYS. THE FORECAST POINTS SHOWING RFC GUIDANCE
ABOVE FLOOD STAGE ARE ALONG THE ROANOKE RIVER AT RANDOLPH...AND
DAN RIVER AT PACES AND SOUTH BOSTON.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PW
LONG TERM...RCS
AVIATION...AMS/PM
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
847 AM PST WED FEB 17 2016
.SYNOPSIS...A FRONTAL SYSTEM WILL BRING LIGHT AMOUNTS OF RAIN TO
THE AREA THIS AFTERNOON AND EVENING. STRONG SOUTHERLY WINDS ARE
EXPECTED TO DEVELOP DURING THE DAY WEDNESDAY. SHOWERS ARE
EXPECTED INTO THURSDAY MORNING AS AN UPPER LEVEL TROUGH MOVES
THROUGH THE AREA. A WEAK WEATHER SYSTEM WILL BRING A CHANCE OF
LIGHT RAIN TO THE NORTHERN PART OF THE DISTRICT FRIDAY. A GRADUAL
WARMING TREND AND DRY WEATHER IS THEN EXPECTED FOR THE UPCOMING
WEEKEND AND INTO THE FIRST PART OF NEXT WEEK.
&&
.DISCUSSION...AS OF 08:47 AM PST WEDNESDAY...MUCH OF THE WEATHER
FOCUS WILL BE IN THE NEAR TERM WITH THREE POTENTIAL
IMPACTS...RAIN...WIND AND THUNDERSTORMS.
LATEST KMUX RADAR IMAGERY CONTINUES TO SHOW ECHOES MOVING FROM
THE SW TO NE WITH THE SOUTHERLY FLOW. DESPITE THE RADAR
RETURNS...PRECIP ACTUALLY HITTING THE GROUND IS NOT WIDESPREAD
YET. THERE HAVE BEEN A FEW REPORTS OF LIGHT RAIN...BUT THE BULK OF
THE RAIN IS STILL EXPECTED TO ACCOMPANY THE COLD FRONT THAT IS
STILL OFF THE COAST. AS FOR WINDS...A WIND ADVISORY STILL REMAINS
IN EFFECT THROUGH THE EVENING. LATEST OBSERVATIONS SHOW GUSTS IN
THE 30-40 MPH...BUT WINDS WILL CONTINUE TO INCREASE THROUGH THE
DAY AS THE COLD FRONT APPROACHES. LASTLY...THUNDERSTORMS WILL BE
POSSIBLE WITH THE FROPA AND AN EVEN BETTER CHANCE BEHIND THE FRONT
AS COLD AIR FILTERS IN. MUCH COLDER AIR ALOFT WILL HELP TO
DESTABILIZE THE ATMOSPHERE AND PROMOTE INCREASING LOW-MID LEVEL
LAPSE RATES. ADDITIONALLY...CAPE AND NEGATIVE LIFTED INDICES
INCREASE POST FRONTAL FROM MONTEREY BAY NORTHWARD. FOR WHAT IT/S
WORTH...THE LATEST SPC TSTORMS OUTLOOK HAS MUCH OF THE BAY AREA
INCLUDED FOR GENERAL THUNDERSTORMS.
NO UPDATE IS PLANNED AT THIS TIME...BUT WILL KEEP A CLOSE EYE ON
PRECIP AND POSS TSTORMS LATER THIS AFTERNOON.
&&
.PREV DISCUSSION...AS OF 3:00 AM PST WEDNESDAY...AN UPPER LEVEL LOW
CENTERED ABOUT 500 MILES OFF THE OREGON COAST IS PROGRESSING
EASTWARD. A FRONTAL SYSTEM WILL BRING INCREASING SOUTH TO
SOUTHEAST WINDS TO THE AREA THIS MORNING AND A WIND ADVISORY IS
IN EFFECT FOR THE MOUNTAINS ABOVE 1000 FEET FROM 7 AM TO 7 PM.
COULD SEE WIND GUSTS OF 40-50 MPH. A FEW ECHOES ARE APPEARING ON
THE RADAR BUT THESE ARE VERY HIGH IN THE ATMOSPHERE AND
PRECIPITATION IS NOT EXPECTED TO BEGIN UNTIL THIS AFTERNOON IN THE
NORTH BAY. RAIN WILL SPREAD INTO THE SFO BAY AREA LATE IN THE
AFTERNOON AND THE MRY BAY AREA TONIGHT. RAIN WILL TURN TO SHOWERS
THURSDAY MORNING AS THE FRONT MOVES THROUGH AND THE UPPER TROUGH
APPROACHES THE COAST. SHOWER ACTIVITY WILL DECREASE THURSDAY
AFTERNOON. TEMPERATURES WILL BE ABOUT 10 TO 15 DEGREES COOLER THAN
TODAY BUT WILL STILL BE NEAR NORMAL. A LITTLE MORE COOLING IS
EXPECTED THURSDAY AS THE TROUGH BRINGS IN SOME COOLER AIR.
RAINFALL AMOUNTS THROUGH THURSDAY SHOULD BE 1/4 TO 1/2 INCH EXCEPT
1/2 TO 1 INCH IN THE COASTAL HILLS. THE INTERIOR VALLEYS OF
MONTEREY AND SAN BENITO COUNTIES WILL GET LESS DUE TO DOWNSLOPE
WIND EFFECTS AHEAD OF THE FRONT.
THE WEATHER SYSTEM FOLLOWING THIS FIRST SYSTEM WILL TRACK FARTHER
NORTH WITH THE TAIL END BRINGING A CHANCE OF LIGHT RAIN FROM THE
SFO BAY AREA NORTH ON FRIDAY. THE SOUTHERN PART OF THE DISTRICT
WILL REMAIN DRY. AN UPPER LEVEL RIDGE WILL REBUILD OVER THE STATE
THIS WEEKEND AND EARLY NEXT WEEK WHILE SURFACE HIGH BUILDS OVER
THE GREAT BASIN BRINGING DRY AND WARMER WEATHER. THE ECMWF
FORECASTS A STRONG RIDGE WITH 500 MB HEIGHTS OF 582 DECAMETERS
OVER SFO. IF THIS VERIFIES THERE COULD BE NEAR RECORD HIGH
TEMPERATURES AGAIN BY MONDAY. THE GFS IS NOT AS STRONG WITH THE
RIDGE AND THEREFORE IS NOT AS WARM.
&&
.AVIATION...AS OF 2:30 AM PST WEDNESDAY...A COLD FRONT WILL REACH
THE AREA THIS EVENING. S-SE WINDS ARE MAINLY LIGHT AT THIS EARLY
HOUR BUT SHOULD BEGIN TO PICK UP THROUGH THE MORNING. WINDS
BECOMING INCREASINGLY GUSTY AHEAD OF THE COLD FRONT TODAY. A FEW
SHOWERS ARRIVING LATER TODAY THEN MORE SHOWERS AS WELL AS ISOLATED
TSTORMS ARE FORECAST FOR TONIGHT AND THURSDAY.
VICINITY OF KSFO....S-SE WINDS INCREASING TODAY. WESTERLY WINDS
TONIGHT AND THURSDAY. VFR TODAY. MVFR CIGS BY EARLY THIS EVENING.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...INCREASING S-SE WINDS TODAY. VFR
TODAY. MVFR CIGS THIS EVENING.
&&
.MARINE...AS OF 2:15 AM PST WEDNESDAY...A COLD FRONT WILL MOVE
THROUGH THE REGION THIS EVENING BRINGING GUSTY WINDS...RAIN AND
POSSIBLY THUNDERSTORMS. SHOWERS WILL CONTINUE TONIGHT AND
THURSDAY. IN ADDITION...A NORTHWEST SWELL WILL INCREASE LATER
THURSDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...WIND ADVISORY...MOUNTAINS ABOVE 1000 FEET.
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PT ARENA TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...MRY BAY FROM 9 AM
SCA...SF BAY UNTIL 11 AM
GLW...SF BAY FROM 11 AM
&&
$$
PUBLIC FORECAST: MM
AVIATION: CANEPA
MARINE: CANEPA
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
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[top]
Area Forecast Discussion
National Weather Service Sacramento CA
840 AM PST WED FEB 17 2016
.SHORT TERM DISCUSSION...
.SYNOPSIS...
Wind, rain, and snow today and tonight. Heaviest rain and snow is
expected overnight. Also a chance of thunderstorms overnight.
Another weaker system Friday.
&&
.Discussion...
Things still on track for a moderate storm system to push through
the area today and tonight. Few tweaks to forecast this morning.
Some wind damage reported in foothills of Nevada county in the
Neveda City and Grass Valley areas. We expanded the wind advisory
to include this area. Would expect these stronger winds to
continue into the evening. Previous wind advisory still looks good
in the valley and haven`t changed that. Other tweak to forecast
was to introduce thunderstorms in the evening times to most of the
valley. NAM and HRRR both forecasting fair instability pushing
into the area behind the front to support this chance. As far as
rain snow totals and snow levels...didn`t change things too much
except to increase values a bit. Rasch
.Previous Discussion...
Light warm sector precipitation now showing up on radar just off
the coast ahead of a cold front now approaching 130 west. High
pressure ridge that has brought record breaking temperatures for
the last several days has now shifted over the Great Basin. Light
precipitation is expected to spread over the north state today
with fairly high snow levels. A fairly tight surface gradient
develops ahead of the offshore front today with good upper level
support so increasing wind is likely. Main frontal band moves
through the north state during the night bringing the heaviest
precipitation. By 12z Thursday morning snow levels take a
significant drop as cold air behind the front moves inland.
Surface pressure gradient remains fairly strong through Thursday
but upper support shifts to westerly by morning so winds should
drop off a bit. A small scale shortwave trough moves across
central California Thursday morning behind the main front and
believe this to be the time for the best threat of an isolated
thunderstorm over the southern Sacramento valley and foothills.
Cloud cover and less subsidence will bring significantly cooler
temperatures today with cold airmass bringing still more cooling
on Thursday. Precipitation drops off significantly by Thursday
evening as slight upper ridging slides over region with decreasing
surface gradient bringing decreasing winds. Light precipitation
will still be possible as light showers spill over the flat ridge.
A much weaker system moves across the west coast on Friday but
this system may be lifted northward enough that the southern
portions of the CWA may not evening get any precipitation. Cool
air still in place for only a slight warm up Friday. West coast
ridge amplifies on Saturday from dry conditions and warmer
temperatures with any precipitation threat lifting north of the
forecast area by Saturday night.
&&
.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Ridge reamplifies Sunday/Monday over the west coast with more
warm temps occurring with up to 2 yr return interval, especially
over northern San Joaquin Valley and adjacent foothills.
Another frontal system impacts the region late Tuesday
into Wednesday. The 17/00Z GFS and ECMWF both have negative tilt
trough axises nearing the coast by next Tuesday afternoon. The
ECMWF appears to be wetter as the trough is deeper and more
amplified as it makes landfall. Model confidence is still
struggling with dynamics, as yesterday indicated that the GFS
would have better dynamics. Either way, both models are moving
northeast and filling, so the system is not very impressive.
JClapp
&&
.AVIATION...
Gradually lowing ceilings today as frontal system approaches.
Precip will begin later this afternoon and continue overnight.
Southerly winds expected to strengthen today and into this
evening with gusts possibly exceeding 35 kts. Light precipitation
will begin in the late morning while heavier showers and MVFR/IFR
conditions are not expected until late afternoon into evening.
JClapp
&&
.STO Watches/Warnings/Advisories...
Winter Storm Warning from 2 PM this afternoon to 4 PM PST
Thursday for West Slope Northern Sierra Nevada-Western Plumas
County/Lassen Park.
Wind Advisory from noon today to midnight PST tonight for
Carquinez Strait and Delta-Central Sacramento Valley-Motherlode-
Northeast Foothills/Sacramento Valley-Northern Sacramento Valley-
Northern San Joaquin Valley-Southern Sacramento Valley.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
320 PM EST WED FEB 17 2016
.DISCUSSION...
...BENIGN WEATHER THROUGH THE UPCOMING WEEKEND...
...POTENTIALLY STORMY NEXT TUESDAY AND QUITE WINDY WEDNESDAY...
TONIGHT/THU...HIGH PRESSURE ACROSS THE EASTERN U.S. WILL TRACK
SLOWLY EASTWARD THROUGH THURSDAY WITH PRESSURE GRADIENT GRADUALLY
TIGHTENING. NORTHERLY WINDS AROUND 5 TO 10 MPH BECOME BREEZY INTO
TOMORROW AS THEY VEER TO THE NORTHEAST. TEMPERATURES WILL ONCE AGAIN
DROP INTO THE UPPER 40S TO LOW 50S OVER MUCH OF THE REGION TONIGHT
WITH HIGHS RANGING FROM THE MID-UPPER 60S ALONG THE COAST FROM THE
CAPE NORTHWARD TO LOW 70S FARTHER SOUTH AND INLAND. NORTHERLY FLOW
WILL MAINTAIN THE DRY AIRMASS OVER THE REGION...KEEPING SKIES CLEAR
TO MOSTLY CLEAR.
FRI-MON (PREV)...SFC HIGH PRESSURE ACROSS THE CAROLINA COAST WILL
KEEP ONSHORE FLOW ACROSS THE AREA FROM THE NE IN THE MORNING AND ENE
IN THE AFTERNOON. 590 DM HIGH CENTER AT H5 ACROSS THE GULF WILL KEEP
A DRY NW FLOW ALOFT WITH MEAGER LOW LVL MOISTURE RETURN FROM THE
ATLC. GFS INDICATES SOME VERY LIGHT QPF OVER THE ATLC WITH ECMWF AND
NAM MAINLY DRY. WILL CONTINUE THE DRY FORECAST WITH HIGHS MODERATED
BY THE CONTINUED ONSHORE FLOW. HIGHS SHOULD REACH THE UPPER 60S
VOLUSIA COAST AND LOWER 70S SRN CSTL AND INTERIOR SECTIONS.
A NICE WEEKEND IS SHAPING UP WEATHER-WISE WITH THE SFC RIDGE
SHIFTING FROM THE FL-GA BORDER SATURDAY TO THE NRN FL PENINSULA ON
SUNDAY. THE AIRMASS WILL REMAIN DRY AS PWATS AVERAGE AROUND .75
INCHES AND ONSHORE FLOW WEAKENS AS RIDGE AXIS BUILDS CLOSER. HIGHS
LOWER 70S COAST TO MID 70S INTERIOR SATURDAY AND THEN WARMING
ANOTHER DEGREE OR TWO SUNDAY WITH MID-UPPER 70S OVER THE INTERIOR.
MINS WILL BE SEASONABLE IN THE 50S...EXCEPT AROUND 60 FOR THE MARTIN
COUNTY COAST.
SFC HIGH WILL SHIFT OFFSHORE MONDAY WITH RETURN LOW LVL SE FLOW
STARTING TO GRADUALLY INCREASE LOW LVL MOISTURE ACROSS THE SRN
PENINSULA. WILL CONTINUE A LOW SHOWER CHANCE FOR THE TREASURE COAST.
HIGHS WILL WARM INTO THE MID-UPPER 70S.
TUE-WED...THERE REMAINS SOME DIFFERENCES AMONG THE GLOBAL MODELS IN
THEIR HANDLING OF THE AMPLITUDE OF A SHORT WAVE TROUGH MOVING FROM
OK/TX TO THE GULF COAST/NRN GOMEX AND THEN THROUGH THE SE/ERN CONUS
AS WELL AS THE RESULTANT SFC LOW FORMATION. THE NEW 12Z ECM REMAINS
PROGRESSIVE/FASTER THAN THE GFS AND HAS TRENDED FARTHER NORTH AT H50
AND WEAKER WITH ITS SURFACE LOW WHILE THE GFS WAS A LITTLE STRONGER
AT BOTH THE SFC/H50 COMPARED TO ITS LAST COUPLE RUNS. BOTH STILL
POINT TO AN INCREASING CHANCE FOR SHOWERS/RAIN BREAKING OUT TUE IN
WARM FRONTOGENETIC TYPE FORCING...FOLLOWED BY A RAPIDLY ADVANCING
SQLN WITH SHOWERS/STRONG STORMS SOMETIME DURING THE TUE NIGHT/EARLY
WED MORNING TIME FRAME.
STILL TOO EARLY TO GET ANY MORE SPECIFIC THAN THAT THIS FAR IN
ADVANCE...GIVEN THE TYPICAL MODEL CONTINUITY AND CONSENSUS ISSUES
THAT FALL IN THE EXTENDED RANGE. WED LOOKS TO BE QUITE WINDY AS SFC
LOW BOMBS ALONG/OFFSHORE THE EASTERN SEABOARD RESULTING IN A VERY
TIGHT LOCAL PGRAD.
HIGHEST RAIN CHCS (50) STILL FOCUSED ON THE TUE-TUE NIGHT TIME
FRAME. WENT WITH A 30 FOR EARLY WED GIVEN THE TIMING ISSUES AND
PROXIMITY OF THE MID LVL TROUGH TO NORTH FL. TUESDAY WILL BE WARM
WITH HIGHS IN THE U70S. THE FRONT SHOULD MOVE EAST OF THE AREA BY
MID DAY WEDNESDAY BUT P SLIGHT SHOWER CHANCE TO NRN AREAS INTO THE
AFTERNOON. WINDY/COOLER WED WITH HIGHS IN THE U60S/L70S EXPECTED.
&&
.AVIATION....MOS AND HRRR GUIDANCE NOT INDICATING ANY FOG
DEVELOPMENT LATE TONIGHT...SO WILL KEEP VFR CONDS IN THE TAFS FOR
THE NEXT 24 HOURS.
&&
.MARINE...
TONIGHT/THU...POOR TO HAZARDOUS BOATING CONDITIONS EXPECTED OVER THE
WATERS. REVISED START TIME OF SMALL CRAFT ADVISORY FOR THE ENTIRE
WATERS TO THU AFT AS THIS IS WHEN NORTHEAST WINDS AROUND 15-20 KNOTS
WILL BEGIN TO INCREASE SEAS UP TO 7 FEET. OTHERWISE SMALL CRAFT WILL
NEED TO EXERCISE CAUTION OFFSHORE TONIGHT AND ACROSS THE ENTIRE
WATERS THU MORNING FOR NORTHERLY WINDS UP TO 15 KNOTS AND SEAS TO 6
FEET.
THU NIGHT-FRI NIGHT...NE WINDS 20-23KT WILL BUILD SEAS TO 6 TO 8
FEET THROUGH FRIDAY MORNING. STRONGER WINDS/HIGHER SEAS WILL LINGER
FROM THE CAPE SWD (ESPECIALLY WELL OFFSHORE) FRI AS WINDS CONTINUE TO
VEER MORE TWD ENE. CONSEQUENTLY HAVE EXTENDED THE SCA FOR THE SRN
AND CTRL OFFSHORE WATERS.
SAT-MON...EASTERLY FLOW 10-15 KNOTS SAT WILL WEAKEN BLO 10KT SUN/MON
AS THE RIDGE AXIS DROPS SWD ACROSS THE CTRL PENINSULA. SEAS 4-6 FT
SAT WILL DROP TO 3-5 FT SUN/MON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 47 66 54 69 / 0 0 10 10
MCO 49 72 53 72 / 0 0 0 0
MLB 52 71 59 70 / 0 0 10 10
VRB 51 72 59 71 / 0 0 10 10
LEE 47 70 50 72 / 0 0 0 0
SFB 50 70 52 71 / 0 0 0 10
ORL 51 71 53 72 / 0 0 0 0
FPR 51 72 59 71 / 0 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 1 PM THURSDAY TO 4 AM EST FRIDAY FOR
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 0-20 NM-
FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-
VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM.
SMALL CRAFT ADVISORY FROM 1 PM THURSDAY TO 4 PM EST FRIDAY FOR
SEBASTIAN INLET TO JUPITER INLET 0-20 NM-SEBASTIAN INLET TO
JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO
SEBASTIAN INLET 20-60 NM.
&&
$$
SHORT TERM/AVIATION...WEITLICH
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS GOODLAND KS
104 PM MST WED FEB 17 2016
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 300 AM MST WED FEB 17 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE
SCALE RIDGE ACROSS WESTERN US WITH NW FLOW ACROSS THE PLAINS. AT
THE SURFACE LOW PRESSURE IS IN PLACE FROM EASTERN COLORADO AND
NEBRASKA WITH TROUGH AXIS ACROSS OUR CWA.
MAIN FORECAST ISSUE CONTINUES TO BE POTENTIAL FOR RECORD
TEMPERATURES AND HIGH IMPACT FIRE WEATHER EVENT THURSDAY. SEE FIRE
WEATHER SECTION FOR DETAILS ON FIRE WEATHER WATCH.
TODAY-FRIDAY NIGHT...LARGE SCALE RIDGE WILL TRANSITION EASTWARD
THROUGH THURSDAY WITH DEEP SW FLOW DEVELOPING THURSDAY ON WESTERN
EXTENT OF UPPER RIDGE AHEAD OF APPROACHING TROUGH. A SHORTWAVE
TROUGH WILL MOVE THROUGH THE REGION WITH A DRY COLD FRONT PASSAGE
THURSDAY NIGHT INTO FRIDAY. DRY CONDITIONS ARE EXPECTED THROUGH THESE
PERIODS. MODEL TEMP PROFILES SHOW GOOD MIXING HEIGHTS IN THE 830-
800MB RANGE THURSDAY...AND THIS WILL HELP MIX STRONGER WINDS TO THE
SURFACE AIDED BY UNIDIRECTIONAL GRADIENT THROUGH 500MB. THIS WOULD
SUPPORT GUSTS IN THE 35-45 MPH RANGE (ASSUMING INCREASING CIRRUS
DOESNT COMPLICATE THINGS FOR US).
HIGH TEMPERATURES TODAY AND THURSDAY WILL BE MUCH ABOVE NORMAL WITH
RECORD HIGHS LIKELY ACROSS OUR CWA ON THURSDAY. LATEST STATISTICAL
GUIDANCE HAS TRENDED A LITTLE WARMER ON HIGHS BOTH DAYS. BASED ON
BIAS CORRECTED 2M TEMPS AND STANDARD BIAS OFF 925MB/850MB TEMPS
ALOFT HIGHS TODAY COULD BE NEAR 70F...AND IN THE LOW TO MID 80S AT
SOME LOCATIONS THURSDAY. A FEW MONTHLY RECORDS COULD BE IN PLAY FOR
THURSDAY. LOW TEMPERATURES WILL ALSO BE UNSEASONABLY HIGH TONIGHT
AND THURSDAY NIGHT...PARTICULARLY THURSDAY NIGHT WHERE WINDY
CONDITIONS WILL KEEP CONDITIONS WELL MIXED DESPITE CAA BEHIND
FROPA. IN FACT WE MAY BE LOOKING AT RECORD HIGH MINS BOTH NIGHTS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 100 PM MST WED FEB 17 2016
PROGRESSIVE ZONAL FLOW WILL PREVAIL ACROSS THE PLAINS ON FRIDAY WITH
RELATIVELY STRONG WESTERLY FLOW ALOFT. A SERIES OF LEE SIDE
SHORTWAVES WILL TRAVERSE THE REGION FRIDAY THROUGH MONDAY WITH A
STRONGER TROUGH EXPECTED TO DEVELOP LATE MONDAY INTO TUESDAY. A
SHORTWAVE H5 RIDGE WILL BRIEFLY BUILD INTO THE REGION ON SATURDAY.
DUE TO WESTERLY FLOW ALOFT AND LACK OF MOISTURE...NO PRECIPITATION
IS EXPECTED WITH THE WEAKER SHORTWAVES FRIDAY THROUGH EARLY MONDAY.
SLIGHT CHANCES FOR PRECIPITATION WILL EMERGE LATE MONDAY INTO
TUESDAY AS THE LARGER TROUGH TRAVERSES THE REGION. EARLY INDICATIONS
POINT TO MAINLY RAIN AS THE DOMINANT PRECIP TYPE WITH A RAIN SNOW
MIX IN THE NORTHERN PORTIONS OF THE CWA EARLY TUESDAY MORNING AS THE
SYSTEM MOVES QUICKLY TO THE EAST. DRY WEATHER WILL RETURN ON
WEDNESDAY WITH NORTH TO NORTHWEST FLOW ALOFT.
TEMPERATURES OVER THE EXTENDED PERIOD WILL REMAIN 7 TO 10 DEGREES
ABOVE NORMAL FOR THE HIGHS AND 5 TO 7 DEGREES ABOVE NORMAL FOR THE
OVERNIGHT LOWS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1120 AM MST WED FEB 17 2016
VFR CONDITIONS EXPECTED FOR THE TAFS. LIGHT TO BREEZY WINDS TODAY
WILL BECOME LIGHT TONIGHT. A STRONG LOW LEVEL JET WILL MOVE OVER
THE TAF SITES TONIGHT CAUSING A FEW HOURS OF LOW LEVEL WIND SHEAR.
LATE TOMORROW MORNING THE LIGHT WINDS WILL INCREASE...BECOMING
GUSTY FOR KGLD DURING THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR KSZ027>029-041-042.
CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR COZ254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...TL
AVIATION...JTL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1121 AM MST WED FEB 17 2016
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 300 AM MST WED FEB 17 2016
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW LARGE
SCALE RIDGE ACROSS WESTERN US WITH NW FLOW ACROSS THE PLAINS. AT
THE SURFACE LOW PRESSURE IS IN PLACE FROM EASTERN COLORADO AND
NEBRASKA WITH TROUGH AXIS ACROSS OUR CWA.
MAIN FORECAST ISSUE CONTINUES TO BE POTENTIAL FOR RECORD
TEMPERATURES AND HIGH IMPACT FIRE WEATHER EVENT THURSDAY. SEE FIRE
WEATHER SECTION FOR DETAILS ON FIRE WEATHER WATCH.
TODAY-FRIDAY NIGHT...LARGE SCALE RIDGE WILL TRANSITION EASTWARD
THROUGH THURSDAY WITH DEEP SW FLOW DEVELOPING THURSDAY ON WESTERN
EXTENT OF UPPER RIDGE AHEAD OF APPROACHING TROUGH. A SHORTWAVE
TROUGH WILL MOVE THROUGH THE REGION WITH A DRY COLD FRONT PASSAGE
THURSDAY NIGHT INTO FRIDAY. DRY CONDITIONS ARE EXPECTED THROUGH THESE
PERIODS. MODEL TEMP PROFILES SHOW GOOD MIXING HEIGHTS IN THE 830-
800MB RANGE THURSDAY...AND THIS WILL HELP MIX STRONGER WINDS TO THE
SURFACE AIDED BY UNIDIRECTIONAL GRADIENT THROUGH 500MB. THIS WOULD
SUPPORT GUSTS IN THE 35-45 MPH RANGE (ASSUMING INCREASING CIRRUS
DOESNT COMPLICATE THINGS FOR US).
HIGH TEMPERATURES TODAY AND THURSDAY WILL BE MUCH ABOVE NORMAL WITH
RECORD HIGHS LIKELY ACROSS OUR CWA ON THURSDAY. LATEST STATISTICAL
GUIDANCE HAS TRENDED A LITTLE WARMER ON HIGHS BOTH DAYS. BASED ON
BIAS CORRECTED 2M TEMPS AND STANDARD BIAS OFF 925MB/850MB TEMPS
ALOFT HIGHS TODAY COULD BE NEAR 70F...AND IN THE LOW TO MID 80S AT
SOME LOCATIONS THURSDAY. A FEW MONTHLY RECORDS COULD BE IN PLAY FOR
THURSDAY. LOW TEMPERATURES WILL ALSO BE UNSEASONABLY HIGH TONIGHT
AND THURSDAY NIGHT...PARTICULARLY THURSDAY NIGHT WHERE WINDY
CONDITIONS WILL KEEP CONDITIONS WELL MIXED DESPITE CAA BEHIND
FROPA. IN FACT WE MAY BE LOOKING AT RECORD HIGH MINS BOTH NIGHTS.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 208 AM MST WED FEB 17 2016
FOR THE EXTENDED PERIOD...THE TRI STATE REGION WILL CONTINUE TO SEE
MAINLY DRY CONDITIONS AND ABOVE NORMAL TEMPERATURES. MID LEVEL FLOW
AT 500MB WILL REMAIN ZONAL THRU THE UPCOMING WEEKEND WITH ANOTHER
BROAD UPPER RIDGE BUILDING ON THE WEST COAST BY THE BEGINNING OF
NEXT WEEK...THEN SHIFTING EASTWARD INTO THE ROCKIES BY MIDWEEK NEXT
WEEK.
BY MONDAY NIGHT...MODELS CONTINUE TO SHOW WEAK SHORTWAVE MOVE SE
ALONG THE EAST SIDE OF THE UPPER RIDGE...THRU EASTERN COLORADO
THEN QUICKLY SOUTH OF THE CWA GOING INTO TUESDAY. BASED ON
CURRENT TRACK...MOST OF THE QPF WILL AVOID THE REGION...LEAVING
ONLY A SLIGHT CHANCE FOR LIGHT RAIN.
WARMEST TIME FRAME IN THE EXTENDED WILL OCCUR ON SATURDAY WITH
WESTERLY ZONAL DOWNSLOPE FLOW OVER THE AREA. LOOKING FOR 60S ON
THAT DAY...WITH A DOWNTREND INTO THE 50S SUNDAY AND MONDAY AS
WINDS SHIFT TO MORE NW ALLOWING FOR COLDER AIR TO FILTER INTO THE
REGION. FOR TUESDAY INTO WEDNESDAY...WITH THE PASSAGE OF THE WEAK
SHORTWAVE...HIGHS WILL ONLY REACH INTO THE U40S TUESDAY WITH NLY A
REBOUND TO AROUND 50F FOR WEDNESDAY. OVERNIGHT LOWS WILL START OFF
INTO THE LOWER 30S SATURDAY NIGHT...W/ 20S FOR THE REMAINDER OF
THE OVERNIGHT PERIODS INTO MIDWEEK NEXT WEEK. SATURDAY THRU MONDAY
WILL END UP HAVING ABOVE NORMAL CONDITIONS...WHILE OVERALL FOR
TUESDAY AND WEDNESDAY...NEAR NORMAL WITH THE ADDITION OF COLDER
AIR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1120 AM MST WED FEB 17 2016
VFR CONDITIONS EXPECTED FOR THE TAFS. LIGHT TO BREEZY WINDS TODAY
WILL BECOME LIGHT TONIGHT. A STRONG LOW LEVEL JET WILL MOVE OVER
THE TAF SITES TONIGHT CAUSING A FEW HOURS OF LOW LEVEL WIND SHEAR.
LATE TOMORROW MORNING THE LIGHT WINDS WILL INCREASE...BECOMING
GUSTY FOR KGLD DURING THE AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 300 AM MST WED FEB 17 2016
MODELS SHOW INCREASING CIRRUS AHEAD OF APPROACHING
TROUGH ON THURSDAY WHICH COULD COMPLICATE MIXING HEIGHTS...HOWEVER
EVEN THEN IT APPEARS HIGHLY LIKELY THAT THE STRONG GRADIENT IN
PLACE OVER OUR CWA WILL STILL SUPPORT RED FLAG CRITERIA WINDS.
FUELS CONTINUE TO BE A QUESTION NORTH OF THE CURRENT WATCH DESPITE
LIKELIHOOD OF RH/WIND CRITERIA DUE TO IMPACTS OF RECENT SNOW MELT.
THIS MAY NOT HAVE AS MUCH OF AN IMPACT ON ONE HOUR FUELS OR
POTENTIAL FOR LARGE GRASS FIRES IN THE FORECAST
CONDITIONS...PARTICULARLY SINCE WE HAVE HAD SEVERAL VERY MILD/DRY
DAYS (AND ANOTHER TODAY). NO CHANGES TO FIRE WEATHER WATCH DURING
THIS UPDATE CYCLE TO ALLOW DAY SHIFT TO COORDINATE FUEL CONDITIONS
WITH OUR FIRE WEATHER PARTNERS.
&&
.CLIMATE...
ISSUED AT 300 AM MST WED FEB 17 2016
RECORDS AND CURRENT FORECAST FOR HIGH TEMPERATURES THURSDAY.
SITE.............DAILY RECORD...CURRENT FORECAST
GOODLAND, KS.........74...............79
MCCOOK, NE...........82...............76
BURLINGTON,CO........74...............79
HILL CITY,KS.........75...............82
COLBY, KS............81...............79
TRIBUNE, KS..........79...............81
YUMA, CO.............73...............75
CURRENT FEBRUARY MONTHLY HIGH TEMP RECORDS...
GOODLAND.....81 (02-28-2006 AND PREVIOUS YEARS)
MCCOOK.......83 (02-23-1933 AND PREVIOUS YEARS)
BURLINGTON...82 (02-11-1962)
HILL CITY....86 (02-28-2006 AND PREVIOUS YEARS)
COLBY........83 (02-12-1911)
TRIBUNE......81 (02-20-1981)
YUMA.........79 (02-12-1962 AND PREVIOUS YEARS)
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR KSZ027>029-041-042.
CO...FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
AFTERNOON FOR COZ254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JN
AVIATION...JTL
FIRE WEATHER...DR
CLIMATE...DR
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1250 PM EST WED FEB 17 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 1250 PM EST WED FEB 17 2016
THE FORECAST WAS UPDATED WITH THE LATEST HOURLY
TEMPERATURE...WIND AND HUMIDITY OBS DATA. ALSO TWEAKED THE WEATHER
TYPE GRIDS TO REFLECT A LONGER DURATION OF SNOW FLURRIES THIS
AFTERNOON AND A MORE ACCURATE EASTWARD PROGRESSION OF THE ONGOING
PRECIPITATION. ALSO REMOVED ANY OUTDATED WORDING FROM THE FORECAST
TEXT PRODUCT. A NEW SET OF ZONES HAVE ALREADY BEEN ISSUED. LAST
BUT NOT LEAST...ALSO UPDATED THE HAZARDOUS WEATHER OUTLOOK TO
REMOVE MENTION OF PATCHY DENSE MORNING FOG.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 500 AM EST WED FEB 17 2016
THE PERIOD IS EXPECTED TO BEGIN WITH A RIDGE PORTIONS OF THE CENTRAL
CONUS INTO THE EASTERN CONUS...WITH A FEW SHORTWAVES MOVING FROM
THE ROCKIES INTO THE PLAINS. FURTHER WEST...A CLOSED LOW IS
EXPECTED TO BE OVER THE GULF OF ALASKA WITH A TROUGH TRIALING
SOUTH ACROSS PORTIONS OF THE EASTERN PACIFIC. OVERALL...THE
PATTERN ACROSS THE CONUS IS FORECAST TO BE RATHER ZONAL IN NATURE
TO END THE WORK WEEK AND INTO THE START OF THE WEEKEND AS THE
RIDGE INITIALLY IN PLACE MOVES EAST. A SHORTWAVE TROUGH SHOULD
PASS WELL NORTH OF THE AREA LATE FRIDAY INTO FRIDAY NIGHT WITH
ANOTHER WEAKER SHORTWAVE TO THE SOUTH MOVING ACROSS THE OH VALLEY
AND APPALACHIANS. AT THE SFC...A LOW PRESSURE SYSTEM SHOULD ALSO
PASS WELL NORTH OF THE AREA...BUT AS THE FLOW BECOMES MORE ZONAL
AND RIDGING REMAINS IN PLACE ACROSS MEXICO AND INTO THE SOUTHEAST
A RATHER MOISTURE STARVED COLD FRONT THAT ENTERS THE OH VALLEY BY
LATE FRIDAY SHOULD MOVE INTO OR ACROSS THE AREA ON SATURDAY AND
THEN STALL OUT OVER OR JUST SOUTH OF THE AREA BY SAT EVENING AND
SAT NIGHT. THIS SYSTEM SHOULD BRING A CHANCE FOR RAIN SHOWERS
MAINLY FRI NIGHT INTO EARLY ON SAT.
AFTER A POSSIBLE LULL IN SHOWER CHANCES...THE BOUNDARY SHOULD
RETURN NORTH AS A WARM FRONT TO START THE WEEKEND. THE TROUGH
APPROACHING THE WESTERN CONUS EARLY IN THE PERIOD IS EXPECTED TO
BECOME AN OPEN SHORTWAVE IN THE WESTERLY FLOW AND MOVE ACROSS THE
PACIFIC NORTHWEST...ROCKIES AND PLAINS AND REACH THE MS AND OH
VALLEY AND GREAT LAKES LATE SAT NIGHT INTO SUNDAY. THIS SYSTEM
SHOULD BRING RENEWED CHANCES FOR SHOWERS SAT NIGHT INTO SUNDAY.
LATE IN THE WEEKEND INTO EARLY NEXT WEEK...THE PATTERN SHOULD
AGAIN BEGIN TO BECOME MORE AMPLIFIED WITH A RIDGE BUILDING ACROSS
THE WEST AND TROUGH TAKING SHAPE FROM CENTRAL CANADA SOUTH INTO
THE CENTRAL CONUS. MODEL UNCERTAINTY FROM RUN TO RUN AND MODEL TO
MODEL IN TIMING AND PHASING OR INTERACTION OF SHORTWAVES AS WELL
AS A CLOSED LOW OVER THE HUDSON BAY REGION LEAD TO UNCERTAINTIES
AS TO HOW MUCH AND HOW FAR NORTH AND WEST DEEPER MOISTURE MAY GET
LATE IN THE PERIOD. THE BOTTOM LINE THE END OF THE PERIOD SHOULD
BE UNSETTLED WITH TEMPERATURES COOLING OFF TO BELOW NORMAL AFTER
STARTING THE EXTENDED PERIOD ABOVE NORMAL.
THESE ALSO LEAD TO UNCERTAINTIES IN THE THERMAL PROFILE BY LATE
IN THE PERIOD AND JUST AFTER THE PERIOD. AT THIS TIME A MODEL
CONSENSUS BLEND WAS USED WHICH KEEP PRECIPITATION CHANCES IN THE
FORECAST FROM SUNDAY THROUGH THE END OF THE PERIOD. THE HIGHEST
CHANCES THOUGH ARE GENERALLY FROM CUMBERLAND VALLEY NORTH AND EAST
ALONG THE VA BORDER AND TO THE WV BORDER...AND LOWER FURTHER
NORTHWEST. AT THIS TIME...WE HAVE KEPT MOST OF THE PRECIP AS ALL
RAIN THROUGH THE END OF THE PERIOD...WITH WINTRY PRECIPITATION
CHANCES POTENTIALLY HIGHER AFTER THE PERIOD. CONFIDENCE IN THIS IS
LOW AND THE EVOLUTION OF THIS POTENTIAL SYSTEM TO AFFECT EAST KY
BEARS WATCHING. WPC HAS HIGHLIGHTED PORTIONS OF THE AREA IN LOW
PROBABILITIES IN THE EXPERIMENTAL DAY 7 WINTER WEATHER
OUTLOOK...WITH HIGHER PROBABILITIES GENERALLY ALONG AND EAST OF
THE CREST OF THE APPALACHIANS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1250 PM EST WED FEB 17 2016
IFR TO LIFR CONDITIONS WILL AFFECT JKL...SYM...AND SJS THROUGH
AROUND 8Z ON THURSDAY...WHILE LOZ AND SME WILL ONLY BE SEEING
THESE CONDITIONS THROUGH 19 OR 20Z TODAY. AFTER 20Z...LOZ AND SME
SHOULD SEE SLIGHTLY IMPROVING CONDITIONS...WITH MVFR CIGS AND LOW
CLOUDS ON TAP THROUGH THE END OF THE TAF PERIOD. SYM SHOULD BEGIN
SEEING MVFR CIGS BETWEEN 8 AND 9Z TOMORROW...WITH JKL AND SJS
FINALLY IMPROVING TO MVFR BETWEEN 10 AND 11Z ON THURSDAY. PATCHY
SPRINKLES AND SNOW FLURRIES WILL CONTINUE TO MOVE ACROSS FAR
EASTERN KENTUCKY THROUGH EARLY THIS EVENING...AND SHOULD BE OUT OF
THE AREA BY 2 OR 3Z TONIGHT. THE PRIMARY AVIATION CONCERN WILL BE
A PERSISTENT AND WIDESPREAD LOW STRATUS DECK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AR
LONG TERM...JP
AVIATION...AR
Area Forecast Discussion
National Weather Service Louisville KY
1224 PM EST WED FEB 17 2016
...Updated Aviation Discussion...
...Forecast Update...
Updated at 1113 AM EST Wed Feb 17 2016
Extended the Special Weather Statement for patches of dense fog into
the early afternoon as area obs and webcams still show reduced
visibility in spots. Best chances for low visibilities appear to be
along and ahead of a weakly defined surface boundary draped just
south of the Ohio River. This feature is only expected to very
slowly sink southward so low visibilities may persist longer. Latest
hi-res data does suggest visibilities improve as we head into the
afternoon as temps struggle to warm just a bit.
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations at
this hour. These are occurring mainly across central KY and should
persist until late morning, and backed up by the latest HRRR
visibility data. So, issued a Special Weather Statement until 11 AM
EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (18Z TAF Update)...
Updated at 1224 PM EST Wed Feb 17 2016
A low confidence aviation forecast as we deal with variable
cig/vsbys.
Mixing has increased surface dew point depressions in all
neighboring states around Kentucky, with a pool of more stubborn
moisture keeping vsbys and cigs low over the Commonwealth. Still,
conditions should slowly improve at Kentucky TAF sites this
afternoon. This has already occurred at SDF where it appears a
subtle surface boundary has passed through.
Tonight is another question mark, concerning redevelopment of any
low stratus or fog. The most model agreement keeps best chances for
sub-VFR conditions over the Lake Cumberland district in conjunction
with a dome of high pressure moving into the region. Will hit poor
flying conditions hardest tonight at LEX and BWG, going easier at
SDF.
All sites should go VFR on Thursday as drier air moves in and we get
some weak return surface flow behind the aforementioned high.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......13
Area Forecast Discussion
National Weather Service Louisville KY
1224 PM EST WED FEB 17 2016
...Updated Aviation Discussion...
...Forecast Update...
Updated at 1113 AM EST Wed Feb 17 2016
Extended the Special Weather Statement for patches of dense fog into
the early afternoon as area obs and webcams still show reduced
visibility in spots. Best chances for low visibilities appear to be
along and ahead of a weakly defined surface boundary draped just
south of the Ohio River. This feature is only expected to very
slowly sink southward so low visibilities may persist longer. Latest
hi-res data does suggest visibilities improve as we head into the
afternoon as temps struggle to warm just a bit.
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations at
this hour. These are occurring mainly across central KY and should
persist until late morning, and backed up by the latest HRRR
visibility data. So, issued a Special Weather Statement until 11 AM
EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (18Z TAF Update)...
Updated at 1224 PM EST Wed Feb 17 2016
A low confidence aviation forecast as we deal with variable
cig/vsbys.
Mixing has increased surface dew point depressions in all
neighboring states around Kentucky, with a pool of more stubborn
moisture keeping vsbys and cigs low over the Commonwealth. Still,
conditions should slowly improve at Kentucky TAF sites this
afternoon. This has already occurred at SDF where it appears a
subtle surface boundary has passed through.
Tonight is another question mark, concerning redevelopment of any
low stratus or fog. The most model agreement keeps best chances for
sub-VFR conditions over the Lake Cumberland district in conjunction
with a dome of high pressure moving into the region. Will hit poor
flying conditions hardest tonight at LEX and BWG, going easier at
SDF.
All sites should go VFR on Thursday as drier air moves in and we get
some weak return surface flow behind the aforementioned high.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......13
Area Forecast Discussion
National Weather Service Louisville KY
1224 PM EST WED FEB 17 2016
...Updated Aviation Discussion...
...Forecast Update...
Updated at 1113 AM EST Wed Feb 17 2016
Extended the Special Weather Statement for patches of dense fog into
the early afternoon as area obs and webcams still show reduced
visibility in spots. Best chances for low visibilities appear to be
along and ahead of a weakly defined surface boundary draped just
south of the Ohio River. This feature is only expected to very
slowly sink southward so low visibilities may persist longer. Latest
hi-res data does suggest visibilities improve as we head into the
afternoon as temps struggle to warm just a bit.
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations at
this hour. These are occurring mainly across central KY and should
persist until late morning, and backed up by the latest HRRR
visibility data. So, issued a Special Weather Statement until 11 AM
EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (18Z TAF Update)...
Updated at 1224 PM EST Wed Feb 17 2016
A low confidence aviation forecast as we deal with variable
cig/vsbys.
Mixing has increased surface dew point depressions in all
neighboring states around Kentucky, with a pool of more stubborn
moisture keeping vsbys and cigs low over the Commonwealth. Still,
conditions should slowly improve at Kentucky TAF sites this
afternoon. This has already occurred at SDF where it appears a
subtle surface boundary has passed through.
Tonight is another question mark, concerning redevelopment of any
low stratus or fog. The most model agreement keeps best chances for
sub-VFR conditions over the Lake Cumberland district in conjunction
with a dome of high pressure moving into the region. Will hit poor
flying conditions hardest tonight at LEX and BWG, going easier at
SDF.
All sites should go VFR on Thursday as drier air moves in and we get
some weak return surface flow behind the aforementioned high.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......13
Area Forecast Discussion
National Weather Service Louisville KY
1115 AM EST WED FEB 17 2016
...Forecast Update...
Updated at 1113 AM EST Wed Feb 17 2016
Extended the Special Weather Statement for patches of dense fog into
the early afternoon as area obs and webcams still show reduced
visibility in spots. Best chances for low visibilities appear to be
along and ahead of a weakly defined surface boundary draped just
south of the Ohio River. This feature is only expected to very
slowly sink southward so low visibilities may persist longer. Latest
hi-res data does suggest visibilities improve as we head into the
afternoon as temps struggle to warm just a bit.
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations at
this hour. These are occurring mainly across central KY and should
persist until late morning, and backed up by the latest HRRR
visibility data. So, issued a Special Weather Statement until 11 AM
EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (12Z TAF Update)...
Updated at 630 AM EST Wed Feb 17 2016
Poor flying conditions this hour, with lots of low-level moisture
making for low cigs and some patches of dense fog as well. The worst
of the fog still is roughly between KSDF and KBWG, but some remains
over KLEX. Expect these poor conditions to last most of the morning,
though SDF has the best chance to break out of it, with slightly
drier air working in from the north. GOES-R MVFR product also has a
gap of VFR conditions just over southern Indiana, but that gap is
not making any quick inroads toward SDF this hour. Have gone with
cigs up to low-end MVFR in the afternoon hours, assuming some
daytime heating allows for better mixing near the surface. For the
outlook period, guidance is calling for cigs to improve in the
evening. Not sold on that idea yet, cause if cigs improve we may
drop vsby`s back down anyway. Will keep MVFR most of the night for
now.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......RJS
Area Forecast Discussion
National Weather Service Louisville KY
910 AM EST WED FEB 17 2016
...Forecast Update...
Updated at 909 AM EST Wed Feb 17 2016
Seeing a few spots of dense fog on area webcams and observations
atthis hour. These are occurring mainly across central KY and
shouldpersist until late morning. Observed visibilities are also
backed upby the latest HRRR visibility data. So, issued a Special
WeatherStatement until 11 AM EST to highlight the concern.
.SHORT TERM (Now through Thursday)...
Issued at 231 AM EST Wed Feb 17 2016
The first concern for the short term period is the patchy dense fog
across the region. The area of the densest fog continues to slowly
move southward this morning as higher level clouds move in from the
north. Coverage of the dense fog continues to be patchy, so will
cover the area of concern with Special Weather Statements for now
and monitor observations through the early morning.
Fog will dissipate by an hour or two after sunrise. Through the
remainder of the day a weak frontal boundary will move into the
region followed quickly by surface high pressure building in
tonight. Temperatures today will top out in the upper 30s to lower
40s under mostly cloudy skies. Models try to squeeze out some very
light precipitation today along the front, but think this would be
very light if anything does occur. With low confidence of any
measurable precip, will keep the forecast dry for now.
High pressure will cross the region tonight and move east of the
area through the day Thursday. Winds will shift to southerly,
beginning to usher in warmer air. We will have one more night of
below freezing temps before the warm up into the weekend really
begins. Highs on Thursday will top out in the mid 40s to lower 50s.
.LONG TERM (Thursday night through Tuesday)...
Issued at 247 AM EST Wed Feb 17 2016
Much milder weather is expected from Friday through the weekend. The
pressure gradient will tighten across the region Thursday night into
Friday as a low pressure system develops across southern Canada.
Strong southerly winds will develop, pumping warmer and more humid
air into the lower Ohio Valley. This will also bring gusty winds on
Friday. Sustained winds will be 15-25 mph with gusts of 30-35 mph
(possibly higher at times). Highs will top out in the lower to mid
60s.
The cold front associated with the low pressure system will approach
and move into the region on Friday night, becoming quasi-stationary
across central KY. Some light rain will be possible on Friday night
with this front. However, it will not bring in colder air and temps
on Saturday will be comparable to Friday, if not a degree or two
warmer.
Another low pressure system will develop across the Midwest Saturday
night and track northeast. A cold front associated with this system
will move through Sunday evening/night. This system will also bring
a better chance for rain on Sunday. Rain chances will linger into
Monday/Monday night mainly across east central KY. We will see quite
a cool down going into the next work week. Highs on Monday look to
be in the upper 40s to lower 50s with highs Tuesday in the mid to
upper 40s.
&&
.AVIATION (12Z TAF Update)...
Updated at 630 AM EST Wed Feb 17 2016
Poor flying conditions this hour, with lots of low-level moisture
making for low cigs and some patches of dense fog as well. The worst
of the fog still is roughly between KSDF and KBWG, but some remains
over KLEX. Expect these poor conditions to last most of the morning,
though SDF has the best chance to break out of it, with slightly
drier air working in from the north. GOES-R MVFR product also has a
gap of VFR conditions just over southern Indiana, but that gap is
not making any quick inroads toward SDF this hour. Have gone with
cigs up to low-end MVFR in the afternoon hours, assuming some
daytime heating allows for better mixing near the surface. For the
outlook period, guidance is calling for cigs to improve in the
evening. Not sold on that idea yet, cause if cigs improve we may
drop vsby`s back down anyway. Will keep MVFR most of the night for
now.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....EER
Long Term......EER
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
329 PM CST WED FEB 17 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 300 PM CST WED FEB 17 2016
PATCHY FOG AND POSSIBLE LIGHT FREEZING DRIZZLE IS IN THE FORECAST
TONIGHT AND EARLY THURSDAY AHEAD OF A MILD THURSDAY AFTERNOON.
LOWER ATMOSPHERIC CONDITIONS TONIGHT INTO THURSDAY MORNING WILL BE
VERY FAVORABLE FOR STRATUS MAINTENANCE AND DEVELOPMENT THANKS TO A
STOUT AND STRENGTHENING INVERSION ALOFT WITH MILD...SOUTHERLY LOW-
LEVEL FLOW THAT WILL ACCESS DEWPOINTS WHICH AVERAGE 30 F UPSTREAM
AS OF MID AFTERNOON. PATCHY FOG IS ALSO INCLUDED IN THE FORECAST
GIVEN EXPECTED BUILD-DOWN OF THE STRATUS...BUT FORECAST SOUNDINGS
SUGGEST THE NEAR-GROUND LAYER MAY BE TOO TURBULENT FOR DENSE FOG
DEVELOPMENT OWING TO SOUTHERLY WINDS OVER 15 KT WITHIN 1000 FT OF
THE SURFACE. THE 15 TO 19 UTC HRRR AND ESRL-HRRR ITERATIONS ON THE
OTHER HAND SIMULATE SOME DENSE FOG DEVELOPMENT...SO WE WILL WATCH
THIS SCENARIO CLOSELY EVEN THOUGH WE BELIEVE THE PROBABILITY OF
ANYTHING MORE THAN TRANSIENT SUB-3/4SM VISIBILITIES IS RATHER LOW.
WE CHOSE TO KEEP A SLIGHT CHANCE OF LIGHT FREEZING DRIZZLE IN THE
FORECAST OVER PARTS OF CENTRAL ND TONIGHT INTO THURSDAY MORNING IN
RESPECT TO THE DEEPENING MOIST LAYER BENEATH THE INVERSION SEEN ON
MODEL-DERIVED FORECAST SOUNDINGS. THE 12 UTC GFS DEEPENS THE MOIST
LAYER SUFFICIENTLY TO GENERATE LIGHT QPF IN ITS SIMULATION ACROSS
NORTH CENTRAL AND EAST CENTRAL ND BETWEEN 06 AND 12 UTC...WHICH IS
SUGGESTIVE OF A VERY LOW PROBABILITY OF BONAFIDE LIGHT FREEZING
RAIN NEAR THE PEAK OF THE WARM-ADVECTIVE REGIME. HOWEVER...THAT IS
AN OUTLIER SOLUTION...AND FORECAST OMEGA FIELDS FROM BOTH THE GFS
AND NAM SUGGEST VERTICAL MOTION IN THE STRATUS LAYER MAY BE WEAK.
WE THUS ARE NOT PARTICULARLY IMPRESSED WITH FREEZING DRIZZLE RISK
EVEN THOUGH IT WAS HIGH ENOUGH TO STILL INCLUDE IN THE FORECAST.
BY THURSDAY AFTERNOON...A VERY MILD AIR MASS WILL BE IN PLACE IN
ADVANCE OF A STRONG 500-MB SHORTWAVE TROUGH EXPECTED TO BE MOVING
INTO THE NORTHERN ROCKIES. LOW CLOUDS MAY HOLD BACK HEATING WHERE
THEY REMAIN THICK ENOUGH THROUGH THE DAY...BUT WITH TEMPERATURES
AT 850 MB OF +13 TO +15 C IN SOUTHWEST ND...HIGHS WILL LIKELY HIT
60 F IN PLACES LIKE BOWMAN...WITH WIDESPREAD 40S AND 50S F SOUTH
AND WEST OF THE MISSOURI RIVER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM CST WED FEB 17 2016
THE LONG TERM APPEARS ACTIVE WITH SEVERAL CHANCES FOR
RAIN...FREEZING RAIN AND SNOW.
TEMPERATURES WILL REMAIN NEAR THE MAGIC FREEZING THRESHOLD AND
THEREFORE A MIX OF RAIN...FREEZING RAIN AND SNOW APPEARS POSSIBLE.
LIGHT FREEZING RAIN AND SNOW APPEAR THE MORE FAVORABLE
PRECIPITATION TYPE DURING THE MORNING AND EVENING
HOURS OF FRIDAY...SATURDAY AND SUNDAY...CHANGING OVER TO MAINLY
RAIN DURING THE AFTERNOONS. ONLY LIGHT AMOUNTS OF MOISTURE ARE
EXPECTED ANY GIVEN DAY...GENERALLY LESS THAN A TENTH OF AN INCH.
A CLIPPER WILL MOVE THROUGH THE NORTHERN PLAINS FRIDAY. THIS
CLIPPER MAY BRING SOME HIGH WINDS TO THE REGION. MIXING WEST
WINDS...STEEP LAPSE RATES AND MODERATE PRESSURE RISES COULD
PRODUCE WINDS AROUND 50 MPH. IF TRENDS CONTINUE TO INDICATE THE
PRESENCE OF THESE FEATURES THEN A WIND ADVISORY APPEARS
LIKELY...WITH A HIGH WIND WARNING POSSIBLE. DECIDED TO WITHHOLD
ISSUING A HIGH WIND WATCH TODAY AS THERE IS SOME UNCERTAINTY WITH
RESPECT TO THE TIMING OF THE PRESSURE RISES AND MIXING DOWN OF
MID-LEVEL WINDS AND HIGHER WINDS AREN`T EXPECTED FOR ANOTHER 48
HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 300 PM CST WED FEB 17 2016
LOW STRATUS WITH IFR AND EVEN LIFR CONDITIONS IS EXPECTED TONIGHT.
CEILINGS LIFTED TO THE MVFR/VFR RANGE IN PARTS OF WESTERN ND THIS
AFTERNOON...BUT THEY WILL FALL BACK INTO LOWER FLIGHT CATEGORIES
TONIGHT AS STRATUS REDEVELOPS.BY EARLY THURSDAY MORNING...CEILINGS
WILL BEGIN TO LIFT INTO MVFR/VFR CATEGORIES...EXCEPT AT KMOT. THERE
WILL BE SOME RISK FOR FREEZING DRIZZLE OVER CENTRAL NORTH DAKOTA
EARLY THURSDAY MORNING...BUT CONFIDENCE IS LOW AT THIS TIME. WINDS
WILL GENERALLY REMAIN LIGHT OUT OF THE SOUTH SOUTHEAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CJS
LONG TERM...AJ
AVIATION...ZH/CJS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
102 PM CST WED FEB 17 2016
.UPDATE...
ISSUED AT 102 PM CST WED FEB 17 2016
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN BLENDING RECENT
OBSERVATIONS INTO HOURLY FORECAST FIELDS. FOG HAS LIFTED...BUT THE
STRATUS LAYER WILL PERSIST THROUGH THE DAY IN MOST AREAS THANKS TO
THE MOIST LAYER BEING TRAPPED UNDER A STRENGTHENING INVERSION.
UPDATE ISSUED AT 945 AM CST WED FEB 17 2016
NO MAJOR CHANGES WERE NEEDED FOR THIS FORECAST UPDATE. DID EXTEND
PATCHY FOG OVER PARTS OF WESTERN AND CENTRAL NORTH DAKOTA UNTIL 18
UTC...BASED ON CURRENT OBSERVATIONS AND LATEST HRRR ITERATIONS.
UPDATE ISSUED AT 628 AM CST WED FEB 17 2016
NO SIGNIFICANT UPDATES EARLY THIS MORNING. BISMARCK 12 UTC
SOUNDING INDICATES POTENTIAL FOR FREEZING DRIZZLE. RADAR SHOWS
SOME VERY LIGHT REFLECTIVITIES OVER CENTRAL NORTH DAKOTA. ALTHOUGH
NOTHING REPORTED AS OF YET AND NO GROUND TRUTH...WILL KEEP A
MENTION OF FREEZING DRIZZLE ACROSS THE CENTRAL THIS MORNING. AREAS
OF FOG CONTINUE IN THE WEST AND PORTIONS OF THE CENTRAL A FEW
LOCALES DOWN TO A QUARTER MILE AND HAVE EXTENDED THE SPS FOR AREAS
OF DENSE FOG THROUGH 14 UTC.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 319 AM CST WED FEB 17 2016
THE MAIN CONCERN IN THE SHORT TERM IS THE CONTINUED MOIST LOW LEVEL
REGIME THAT IS PROGGED TO REMAIN OVER THE STATE TODAY AND
TONIGHT...WITH AREAS OF FOG AND LINGERING LIGHT SNOW AND POTENTIAL
FOR FREEZING DRIZZLE.
CURRENTLY...COLD SURFACE HIGH PRESSURE WAS CENTERED OVER THE BORDER
OF NORTHERN MINNESOTA/MANITOBA/ONTARIO WITH A SOUTHEAST SURFACE FLOW
ACROSS THE DAKOTAS INTO SASKATCHEWAN AND WESTERN MANITOBA. MEANWHILE
A MILD PACIFIC HIGH WAS IN THE LEE OF THE ROCKIES OVER WESTERN
MONTANA/WYOMING/COLORADO. BETWEEN THE TWO HIGH PRESSURE SYSTEMS WAS
A LARGE AREA OF LOW LEVEL STRATUS EXTENDING FROM EASTERN SOUTH
DAKOTA ACROSS NORTH DAKOTA AND INTO SASKATCHEWAN/MANITOBA. AT UPPER
LEVELS...A WESTERN RIDGE WAS OVER THE ROCKIES WITH A TROUGH FROM
HUDSON BAY SOUTH ACROSS THE GREAT LAKES AND OHIO VALLEY.
REGIONAL RADARS INDICATE THE AREAS OF LIGHT SNOW AND PERHAPS SOME
ISOLATED PATCHES OF FREEZING DRIZZLE WERE DIMINISHING OVER THE PAST
COUPLE OF HOURS. CHANCES OF LIGHT PRECIPITATION EARLY THIS MORNING
WILL DIMINISH WITH TIME THIS MORNING. WILL KEEP THE MENTION OF AREAS
OF FOG ACROSS THE WEST HALF OF THE STATE EARLY THIS MORNING.
TODAY AND TONIGHT THE UPPER LEVEL RIDGE IS FORECAST TO BEGIN MOVING
EASTWARD...AND A DRY WESTERLY/SOUTHWESTERLY FLOW ALOFT SHOULD BEGIN
MOVING OVER THE COOL AND MOIST SURFACE AIRMASS. THE INITIAL WESTERLY
FLOW OF DRY AIR SHOULD BEGIN IN SOUTHWESTERN NORTH DAKOTA AFTER
DAYBREAK THIS MORNING AND PUSH INTO CENTRAL NORTH DAKOTA BY
AFTERNOON...AND REACH EASTERN NORTH DAKOTA THIS EVENING. THE DRY
SOUTHWESTERLY FLOW ALOFT CONTINUES THROUGH TONIGHT AND STRENGTHENS
WITH INCREASED H850 WINDS. HOWEVER...THE MOIST SOUTHEASTERLY SURFACE
FLOW CONTINUES TODAY AND TONIGHT. THUS THE DEEP COOL AND MOIST LAYER
OVER THE STATE THIS MORNING BEGINS TO ERODE FROM MID LEVELS DOWN
TOWARDS THE SURFACE WITH TIME. THERE IS A HINT THAT SOME LOW LEVEL
MOISTURE WILL FINALLY ERODE FROM FAR SOUTHWESTERN NORTH DAKOTA THIS
AFTERNOON (HENCE THE FORECAST HIGHS IN THE 50S FAR SOUTHWEST)...BUT
THE SOUTHEASTERLY SURFACE FLOW DOMINATES AND THE MODELS ARE
FORECASTING THE LOW LEVEL MOISTURE/STRATUS TO EXPAND BACK WESTWARD
ACROSS WESTERN NORTH DAKOTA TONIGHT.
THE RESULT WILL BE LOW CLOUDS OVER MOST OF THE STATE TODAY...WITH A
BREAK IN THE LOW CLOUDS SOUTHWEST THIS AFTERNOON...THEN LOW CLOUDS
AND STRATUS DOMINATING AGAIN TONIGHT. THERE SHOULD BE A LARGE
CONTRAST IN HIGH TEMPERATURES TODAY...WITH 50S IN THE SOUTHWEST
BUT 30S OVER THE NORTHWEST AND CENTRAL UNDER THE INFLUENCE OF THE
STRATUS CLOUDS.
THE STRONG WARMING AND DRYING ALOFT TONIGHT COMBINED WITH A
REINFORCED MOIST SOUTHEASTERLY SURFACE FLOW WILL RESULT IN A
SUPERCOOLED SURFACE BOUNDARY LAYER THAT WOULD SUPPORT DRIZZLE.
TEMPERATURES TONIGHT ARE FORECAST TO BE IN THE MID TO UPPER 20S OVER
CENTRAL NORTH DAKOTA...THUS THERE IS A POTENTIAL FOR AREAS OF FOG
AND THE POTENTIAL FOR FREEZING DRIZZLE OVER CENTRAL NORTH DAKOTA
TONIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 319 AM CST WED FEB 17 2016
THE MAIN FORECAST ISSUE IN THE LONG TERM PERIOD IS PRECIPITATION
CHANCES AND TYPES THURSDAY AND THURSDAY NIGHT...THEN WINDS ON
FRIDAY.
A PROGRESSIVE FLOW PATTERN AND SEASONABLY WARM TEMPERATURES WILL
RESULT IN A SERIES OF SYSTEMS WITH MIXED PRECIPITATION AND PERIODIC
WINDY PERIODS.
WE BEGIN THE LONG TERM PERIOD ON THURSDAY WITH AN UPPER LEVEL TROUGH
MOVING ONTO THE PACIFIC NORTHWEST COAST. DOWNSTREAM...UPPER LEVEL
RIDGING AND STRONG WARM ADVECTION IS PUSHING FROM EASTERN MONTANA
INTO THE WESTERN DAKOTAS. FARTHER EAST OVER CENTRAL NORTH DAKOTA
SOUTHEAST SURFACE FLOW IS KEEPING ABUNDANT LOW LEVEL MOISTURE NEAR
THE SURFACE WITH WARM ADVECTION AND WEAK SHORTWAVE ENERGY ALOFT.
WILL KEEP A MENTION OF FREEZING DRIZZLE THROUGH MID-MORNING IN THE
SOUTH CENTRAL AND THROUGH THE MORNING NORTH CENTRAL AS TEMPERATURES
REMAIN BELOW FREEZING HERE. ALSO KEPT A MENTION OF FOG THROUGH MID
MORNING ACROSS THE FORECAST AREA.
STRONG WARM ADVECTION PUSHES INTO WESTERN NORTH DAKOTA DURING THE
DAY AND SHOULD CLEAR THE LOW CLOUDS AT LEAST OVER THE SOUTHWEST
PORTION OF THE STATE...THUS TEMPERATURES IN THE UPPER 50S ARE
EXPECTED...WITH A STRONG GRADIENT TO MID 30S OVER THE NORTHEAST CWA.
WARM FRONT AND ASSOCIATED SURFACE LOW PRESSURE MOVE ACROSS WESTERN
AND CENTRAL NORTH DAKOTA THURSDAY NIGHT AS THE UPPER LEVEL WAVE
MOVES ACROSS THE NORTHERN/CENTRAL ROCKIES AND INTO THE PLAINS.
MODELS ARE STILL NOT IN GREAT AGREEMENT IN RESULTANT QPF PATTERN.
THE GFS AND GEM ARE LIGHTER WITH THE QPF MOVING THROUGH THE FORECAST
AREA THURSDAY NIGHT AND KEEP HIGHER QPF AMOUNTS ALONG AND NORTH OF
THE CANADIAN BORDER. THE NAM/ECMWF BRING A MORE WIDESPREAD AREA OF
QPF ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ALTHOUGH THE NAM GETS
TOO AGGRESSIVE WITH THE QPF. FOR NOW A BLEND SEEMS REASONABLE WITH A
PRECIPITATION PATTERN SIMILAR TO THE ECMWF BUT TONED DOWN A LITTLE.
THIS WOULD BRING THE BULK OF THE PRECIPITATION INTO THE WEST DURING
THE EVENING AND SPREADING ACROSS CENTRAL NORTH DAKOTA AFTER
MIDNIGHT. WE STILL HAVE A MENTION OF FREEZING RAIN AND SLEET OVER
THE NORTH CENTRAL AND INTO THE NORTHERN JAMES RIVER VALLEY AND THIS
SEEMS REASONABLE LOOKING AT BUFKIT SOUNDINGS. BUT BUFKIT SOUNDINGS
ALSO SUGGEST THAT SURFACE TEMPERATURES RISE ENOUGH WITH THE WARM
ADVECTION THURSDAY NIGHT THAT MOST PRECIPITATION MAY FALL AS RAIN.
WILL CERTAINLY NEED TO MONITOR AND CERTAINLY NOT CONFIDENT ENOUGH TO
PULL MENTION OF SLEET AND FREEZING RAIN...ESPECIALLY ACROSS THE
NORTH CENTRAL INTO THE JAMES RIVER VALLEY...BUT FOR POINTS WEST OF
HERE IT LOOKS LIKE MAINLY RAIN. WE DID UTILIZE A BLEND OF RAW MODEL
DATA FOR FORECAST LOWS THURSDAY NIGHT AS SUPERBLEND GUIDANCE WAS TOO
COLD.
ONCE THE SURFACE LOW MOVES THROUGH THE FORECAST AREA STRONG WESTERLY
WINDS DEVELOP. BOUNDARY LAYER WINDS THROUGH THE DAY REMAIN FROM
35 TO 45 KNOTS ACROSS MOST OF THE CWA. THUS IF CONDITIONS HOLD
WOULD EXPECT WIND ADVISORY ACROSS THE CWA...WITH THE POTENTIAL FOR
HIGH WIND WARNING POSSIBLY IN THE SOUTHWEST.
FRIDAY NIGHT THROUGH SUNDAY...ANOTHER CLIPPER SYSTEM WITH WARM AIR
ADVECTION AHEAD OF THIS SYSTEM FRIDAY AND THE ACTUAL CLIPPER
SWEEPING ACROSS SATURDAY EVENING THROUGH SUNDAY. HIGHEST
PRECIPITATION CHANCES SLATED FOR NORTHERN NORTH DAKOTA SATURDAY
THROUGH SUNDAY WITH DRIER CONDITIONS SOUTH. WINDS INCREASE SATURDAY
NIGHT BUT REMAIN UNDER ADVISORY CRITERIA FOR NOW...WEST TO NORTHWEST
WIND OF 20 TO 30 MPH. ANOTHER WEAK WAVE MOVES THROUGH MONDAY
BRINGING SMALL CHANCES OF LIGHT SNOW AND COOLER TEMPERATURES
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 102 PM CST WED FEB 17 2016
LINGERING FOG IN THE WEST WILL CONTINUE TO LIFT EARLY THIS
AFTERNOON...HOWEVER LOW STRATUS WILL STICK AROUND THROUGH MOST OF
THE DAY AT MOST SITES...CREATING IFR AND EVEN LIFR CONDITIONS
THROUGH TONIGHT. THE EXCEPTION WILL BE IN THE FAR WEST AROUND
KISN/KDIK...WHERE CEILINGS WILL LIFT TO MVFR/VFR IN THE AFTERNOON.
BY EARLY THURSDAY MORNING...CEILINGS WILL BEGIN TO LIFT
ELSEWHERE...EXCEPT FOR KMOT...INTO MVFR/VFR CATEGORIES. THERE WILL
BE SOME RISK FOR FREEZING DRIZZLE OVER CENTRAL NORTH DAKOTA EARLY
THURSDAY MORNING...BUT CONFIDENCE IS LOW AT THIS TIME. WINDS WILL
GENERALLY REMAIN LIGHT OUT OF THE SOUTH SOUTHEAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...JV
LONG TERM...TWH
AVIATION...ZH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1110 AM CST WED FEB 17 2016
.DISCUSSION...
18Z TAF DISCUSSION BELOW.
&&
.AVIATION...
VFR CONDITIONS EXPECTED WITH SOME HIGH CLOUDS POSSIBLE THURSDAY.
WINDS WILL BECOME STRONG ACROSS THE AREA FROM THE SOUTHWEST AND
WEST THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 1014 AM CST WED FEB 17 2016/
UPDATE...
WINDS WERE INCREASED SLIGHTLY FOR THIS AFTERNOON. PLEASE SEE
DISCUSSION BELOW.
DISCUSSION...
MIXING HAS COMMENCED LATE THIS MORNING AND WIND SPEEDS HAVE
QUICKLY INCREASED ACROSS W/NW OK AS A RESULT. THE HRRR SEEMS TO
HAVE A GOOD HANDLE ON CURRENT TRENDS SO THE WINDS THROUGH 00Z WERE
HEAVILY WEIGHTED TOWARD IT (~15 TO 20 KT ACROSS W/NW OK).
OTHERWISE, NO CHANGES WERE NEEDED. DEWPOINTS AND TEMPS LOOK GOOD.
ALL UPDATED PRODUCTS WILL BE OUT SHORTLY.
PREV DISCUSSION... /ISSUED 420 AM CST WED FEB 17 2016/
DISCUSSION...
THE PRIMARY WEATHER ISSUE IN THE SHORT TERM WILL BE THE FIRE
WEATHER POTENTIAL TOMORROW. WINDY CONDITIONS ARE EXPECTED AS
STRONG LEE TROUGH DEVELOPS AND INCREASES THE PRESSURE GRADIENT
ACROSS THE AREA. HAVE MUCH LOWER CONFIDENCE IN THE MOISTURE
FIELDS FROM THE SYNOPTIC MODELS AS SURFACE DEWPOINTS HAVE BEEN
HIGHLY OVERESTIMATED IN THE LAST FEW FIRE WEATHER DAYS IN THE
WEST. ON THE CURRENT SYNOPTIC SCALE... THE SURFACE FRONT HAS MADE
IT DOWN INTO THE NORTHERN GULF OF MEXICO AND HAS STALLED SOMEWHERE
NEAR KINGSVILLE IN SOUTH TEXAS. SOUTHERLY WINDS WILL BEGIN TO
ADVECT MOISTURE BACK NORTH LATER TODAY AND TONIGHT... BUT HAVE
DOUBTS ABOUT MOISTURE DEPTH BY TOMORROW. A DRYLINE WILL PUSH INTO
THE WESTERN SECTIONS OF THE AREA TOMORROW AFTERNOON WITH MUCH
LOWER DEWPOINTS WEST OF THE DRYLINE AND A HIGH LIKELIHOOD OF
CRITICAL FIRE WEATHER CONDITIONS IN AT LEAST NORTHWEST OKLAHOMA.
THE QUESTION WILL BE HOW FAR EAST DOES THE DRYLINE MIX. HAVE
CREATED THE GRIDS TO BRING THE DRYLINE FARTHER EAST THAN THE
SYNOPTIC MODELS WOULD INDICATE. NAM AND ECMWF BARELY BRING THE
TIGHT MOISTURE GRADIENT TO THE NORTHWESTERN BORDER AND GFS IS
FARTHER EAST BUT STILL LIKELY UNDERESTIMATING THE DRYLINE
MOVEMENT. HAVE THE DRYLINE MAKING IT TO A LINE FROM NORTH OF ALVA
TO NEAR CHEYENNE IN THE FORECAST... AND WILL MAINTAIN THE FIRE
WEATHER WATCH IN THIS AREAS. BUT WOULD NOT BE AT ALL SURPRISED IF
THE DRYLINE MOVES FARTHER EAST. THE OTHER QUESTION IS IF MOISTURE
WILL MIX OUT SUFFICIENTLY EVEN EAST OF THE DRYLINE TO MEET RED
FLAG CONDITIONS IN NORTH TEXAS AND FAR SOUTHWEST OKLAHOMA. HAVE
SEEN OVER THE YEARS THE TENDENCY FOR MOISTURE TO MIX OUT MORE
OVER NORTHWEST TEXAS THAN SURROUNDING AREAS IN THESE TYPES OF
SITUATIONS AND EVEN THE SYNOPTIC MODEL DEWPOINT FIELDS HINT AT
MIXING MOISTURE OUT MORE SIGNIFICANTLY DOWN THERE. WILL DEFINITELY
BE WATCHING TRENDS IN MOISTURE RETURN TODAY AND AGAIN OVERNIGHT TO
FURTHER DEFINE THE FIRE WEATHER RISK AREA FOR TOMORROW. RIGHT NOW
THE AREA OF THE FIRE WEATHER WATCH STILL LOOKS GOOD... BUT AGAIN
INTERESTS THROUGHOUT WESTERN OKLAHOMA AND WESTERN NORTH TEXAS
SHOULD MONITOR THE SITUATION.
A COLD FRONT MOVES IN FRIDAY MORNING BRINGING TEMPERATURES DOWN A
BIT IN THE NORTH... ALTHOUGH IT WILL BE QUITE WARM AGAIN IN THE
SOUTH ON FRIDAY. HUMIDITY WILL BE A LITTLE HIGHER AND WINDS
LIGHTER THAN THURSDAY... SO FIRE WEATHER CONCERNS ARE NOT QUITE AS
HIGH. VERY WARM WEATHER IS EXPECTED AGAIN SATURDAY BEFORE A
SLIGHTLY STRONGER FRONT COOLS THINGS A BIT MORE FOR SUNDAY
/ALTHOUGH IT IS HARD TO SAY COOL AS TEMPERATURES WILL REMAIN 10-15
DEGREES ABOVE AVERAGE/. THERE WILL BE SOME PRECIPITATION CHANCES
EARLY IN THE WEEK AS A MID-LEVEL TROUGH BEGINS TO AMPLIFY OVER THE
PLAINS AND THE COLD FRONT REMAINS IN THE VICINITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 48 77 56 / 0 0 0 0
HOBART OK 72 49 79 53 / 0 0 0 0
WICHITA FALLS TX 74 48 82 57 / 0 0 0 0
GAGE OK 75 47 84 49 / 0 0 0 0
PONCA CITY OK 70 47 77 54 / 0 0 0 0
DURANT OK 69 47 73 58 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH THURSDAY AFTERNOON FOR OKZ004-005-009-010-014.
TX...NONE.
&&
$$
03/25/25
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1014 AM CST WED FEB 17 2016
.UPDATE...
WINDS WERE INCREASED SLIGHTLY FOR THIS AFTERNOON. PLEASE SEE
DISCUSSION BELOW.
&&
.DISCUSSION...
MIXING HAS COMMENCED LATE THIS MORNING AND WIND SPEEDS HAVE
QUICKLY INCREASED ACROSS W/NW OK AS A RESULT. THE HRRR SEEMS TO
HAVE A GOOD HANDLE ON CURRENT TRENDS SO THE WINDS THROUGH 00Z WERE
HEAVILY WEIGHTED TOWARD IT (~15 TO 20 KT ACROSS W/NW OK).
OTHERWISE, NO CHANGES WERE NEEDED. DEWPOINTS AND TEMPS LOOK GOOD.
ALL UPDATED PRODUCTS WILL BE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 420 AM CST WED FEB 17 2016/
DISCUSSION...
THE PRIMARY WEATHER ISSUE IN THE SHORT TERM WILL BE THE FIRE
WEATHER POTENTIAL TOMORROW. WINDY CONDITIONS ARE EXPECTED AS
STRONG LEE TROUGH DEVELOPS AND INCREASES THE PRESSURE GRADIENT
ACROSS THE AREA. HAVE MUCH LOWER CONFIDENCE IN THE MOISTURE
FIELDS FROM THE SYNOPTIC MODELS AS SURFACE DEWPOINTS HAVE BEEN
HIGHLY OVERESTIMATED IN THE LAST FEW FIRE WEATHER DAYS IN THE
WEST. ON THE CURRENT SYNOPTIC SCALE... THE SURFACE FRONT HAS MADE
IT DOWN INTO THE NORTHERN GULF OF MEXICO AND HAS STALLED SOMEWHERE
NEAR KINGSVILLE IN SOUTH TEXAS. SOUTHERLY WINDS WILL BEGIN TO
ADVECT MOISTURE BACK NORTH LATER TODAY AND TONIGHT... BUT HAVE
DOUBTS ABOUT MOISTURE DEPTH BY TOMORROW. A DRYLINE WILL PUSH INTO
THE WESTERN SECTIONS OF THE AREA TOMORROW AFTERNOON WITH MUCH
LOWER DEWPOINTS WEST OF THE DRYLINE AND A HIGH LIKELIHOOD OF
CRITICAL FIRE WEATHER CONDITIONS IN AT LEAST NORTHWEST OKLAHOMA.
THE QUESTION WILL BE HOW FAR EAST DOES THE DRYLINE MIX. HAVE
CREATED THE GRIDS TO BRING THE DRYLINE FARTHER EAST THAN THE
SYNOPTIC MODELS WOULD INDICATE. NAM AND ECMWF BARELY BRING THE
TIGHT MOISTURE GRADIENT TO THE NORTHWESTERN BORDER AND GFS IS
FARTHER EAST BUT STILL LIKELY UNDERESTIMATING THE DRYLINE
MOVEMENT. HAVE THE DRYLINE MAKING IT TO A LINE FROM NORTH OF ALVA
TO NEAR CHEYENNE IN THE FORECAST... AND WILL MAINTAIN THE FIRE
WEATHER WATCH IN THIS AREAS. BUT WOULD NOT BE AT ALL SURPRISED IF
THE DRYLINE MOVES FARTHER EAST. THE OTHER QUESTION IS IF MOISTURE
WILL MIX OUT SUFFICIENTLY EVEN EAST OF THE DRYLINE TO MEET RED
FLAG CONDITIONS IN NORTH TEXAS AND FAR SOUTHWEST OKLAHOMA. HAVE
SEEN OVER THE YEARS THE TENDENCY FOR MOISTURE TO MIX OUT MORE
OVER NORTHWEST TEXAS THAN SURROUNDING AREAS IN THESE TYPES OF
SITUATIONS AND EVEN THE SYNOPTIC MODEL DEWPOINT FIELDS HINT AT
MIXING MOISTURE OUT MORE SIGNIFICANTLY DOWN THERE. WILL DEFINITELY
BE WATCHING TRENDS IN MOISTURE RETURN TODAY AND AGAIN OVERNIGHT TO
FURTHER DEFINE THE FIRE WEATHER RISK AREA FOR TOMORROW. RIGHT NOW
THE AREA OF THE FIRE WEATHER WATCH STILL LOOKS GOOD... BUT AGAIN
INTERESTS THROUGHOUT WESTERN OKLAHOMA AND WESTERN NORTH TEXAS
SHOULD MONITOR THE SITUATION.
A COLD FRONT MOVES IN FRIDAY MORNING BRINGING TEMPERATURES DOWN A
BIT IN THE NORTH... ALTHOUGH IT WILL BE QUITE WARM AGAIN IN THE
SOUTH ON FRIDAY. HUMIDITY WILL BE A LITTLE HIGHER AND WINDS
LIGHTER THAN THURSDAY... SO FIRE WEATHER CONCERNS ARE NOT QUITE AS
HIGH. VERY WARM WEATHER IS EXPECTED AGAIN SATURDAY BEFORE A
SLIGHTLY STRONGER FRONT COOLS THINGS A BIT MORE FOR SUNDAY
/ALTHOUGH IT IS HARD TO SAY COOL AS TEMPERATURES WILL REMAIN 10-15
DEGREES ABOVE AVERAGE/. THERE WILL BE SOME PRECIPITATION CHANCES
EARLY IN THE WEEK AS A MID-LEVEL TROUGH BEGINS TO AMPLIFY OVER THE
PLAINS AND THE COLD FRONT REMAINS IN THE VICINITY.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 70 48 77 56 / 0 0 0 0
HOBART OK 72 49 79 53 / 0 0 0 0
WICHITA FALLS TX 74 48 82 57 / 0 0 0 0
GAGE OK 75 47 84 49 / 0 0 0 0
PONCA CITY OK 70 47 77 54 / 0 0 0 0
DURANT OK 69 47 73 58 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FIRE WEATHER WATCH THURSDAY AFTERNOON FOR OKZ004-005-009-010-014.
TX...NONE.
&&
$$
03/25
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
232 PM EST WED FEB 17 2016
.SHORT TERM (TONIGHT AND TOMORROW)...
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A
TROUGH ACROSS THE EASTERN CONUS WITH A RIDGE BACK TO THE WEST NEAR
THE ROCKY MOUNTAINS MOVING INTO THE GREAT PLAINS. CLOSER TO
HOME...THERE IS A WEAK SHORTWAVE TROUGH MOVING FROM THE OHIO RIVER
VALLEY INTO THE SOUTHERN APPALACHIANS. PW VALUES REMAIN AROUND A
QUARTER OF AN INCH. HOWEVER...THE NORTHWESTERLY FLOW AND WEAK LIFT
FROM THE TROUGH ARE SUFFICIENT ENOUGH TO PRODUCE A FEW LIGHT
SPRINKLES/FLURRIES ACROSS THE HIGH TERRAIN IN SW VA AND ALONG THE
TN/NC LINE. WENT AHEAD AND EXTENDED A SMALL MENTION FOR PRECIP. FOR
THESE LOCATIONS THROUGH 03Z...WHEN THE RAP INDICATES THAT IT WILL
PUSH OFF TO THE EAST. ANOTHER CHALLENGE FOR TONIGHT WILL BE CLOUD
COVER. CLOUDS HAVE HELD IN MUCH LONGER TODAY THAN ANTICIPATED WITH
WEAK LOW LEVEL LIFT. CLOUDS SHOULD FINALLY BEGIN TO DISSIPATE
TONIGHT FROM SOUTHWEST TO NORTHEAST. THERE COULD ALSO BE SOME
PATCHY FOG TONIGHT ACROSS THE AREA BUT HAVE NOT INCLUDED THIS IN
THE FORECAST JUST YET.
FOR TOMORROW...SKIES WILL FINALLY BECOME MOSTLY SUNNY WITH SURFACE
HIGH PRESSURE MOVING OFF TO THE NORTHEAST. THE UPPER LEVEL RIDGE
TO THE WEST WILL MOVE INTO THE AREA. THEREFORE...WITH HEIGHT
RISES...MOSTLY SUNNY SKIES...TEMPERATURES WILL WARM INTO THE UPPER
40S TO MID 50S ACROSS THE AREA.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...
AN UPPER LEVEL RIDGE AND ASSOCIATED HIGH PRESSURE WILL BE PRESENT
OVER THE SOUTHEAST U.S. THURSDAY NIGHT AND FRIDAY MORNING...WITH
MOSTLY CLEAR SKIES AND NEAR NORMAL LOW TEMPERATURES THURSDAY NIGHT.
AS THE HIGH PRESSURE MOVES EAST...STRONG SOUTHWESTERLY WINDS SET
UP...BRINGING STRONG WARM AIR ADVECTION AND MOISTURE TO THE
SOUTHERN APPALACHIANS. WINDS WILL BE STRONG AND GUSTY ACROSS THE
AREA...ESPECIALLY NORTHERN PLATEAU AND SOUTHWEST VA FRIDAY
AFTERNOON. HIGH TEMPERATURES WILL BE SEVERAL DEGREES ABOVE NORMAL
FRIDAY.
FRIDAY NIGHT THROUGH SATURDAY...A FRONTAL BOUNDARY WILL MOVE INTO
THE AREA...WITH CLOUDS INCREASING FROM NORTHWEST TO SOUTHEAST. VERY
LITTLE LIFT ASSOCIATED WITH THIS WEAK BOUNDARY...SO ONLY KEPT SLIGHT
CHANCE POP IN. BY SATURDAY AFTERNOON...LOW LEVEL FLOW TRANSITIONS TO
OUT OF THE WEST...WITH TEMPERATURES ONLY EXPECTED TO WARM A DEGREE
OR TWO FROM FRIDAY. SATURDAY NIGHT THROUGH SUNDAY...ANOTHER LOW
PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE OHIO VALLEY WITH AN
ASSOCIATED FRONT MOVING IN FROM THE WEST BRINGING A HIGHER CHANCE
FOR RAIN SUNDAY EVENING AND SUNDAY NIGHT. VERY LITTLE INSTABILITY
AND FORCING WITH THIS SYSTEM...WITH WINDS BECOMING STRONG IN AREAS
NORTH OF I40. ONLY EXPECTING SCATTERED LIGHT SHOWERS THROUGH SUNDAY
NIGHT. TEMPERATURES WILL STAY WELL ABOVE AVERAGE SUNDAY AND SUNDAY
NIGHT.
MONDAY THROUGH WEDNESDAY...COLDER AIR FILTERS BEHIND THE
FRONT...WITH TEMPERATURES DROPPING ABOUT 10 DEGREES...BUT STAYING A
FEW DEGREES ABOVE NORMAL. A LOW PRESSURE SYSTEM WILL DEVELOP ALONG
THE GULF STATES. THIS LOW WILL SLOWLY TRACK EAST MONDAY NIGHT AND
TUESDAY...THROWING MOISTURE AND WARM TEMPS INTO THE AREA. KEPT
CHANCE TO LIKELY POPS GOING THROUGH THE BEGINNING OF THE
WORKWEEK...WITH SCATTERED TO WIDESPREAD SHOWERS EXPECTED. MODELS
DIFFER GREATLY FROM RUN TO RUN ON THE STRENGTH OF THE LOW AND THE
TRACK. MODELS SHOW THE LOW MOVING IN A GENERAL DIRECTION UP THE EAST
SIDE OF THE APPALACHIANS. WITH THAT TRACK...FLOW WILL TRANSITION
OUT OF THE NORTH...WITH COLD AIR MOVING IN AND SNOW POSSIBLE.
LOOKS LIKE THE MAIN CHANCE FOR SNOW IS GOING TO BE WEDNESDAY...BUT
OF COURSE THIS IS TOO FAR OUT TO SAY WITH MUCH CONFIDENCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 33 57 37 63 / 0 0 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 30 51 33 62 / 0 0 0 10
OAK RIDGE, TN 30 51 33 62 / 0 0 0 10
TRI CITIES AIRPORT, TN 28 47 28 61 / 10 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/JW
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
255 PM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL CROSS THROUGH THE OHIO VALLEY TONIGHT...THEN
WILL DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND WILL COVER MUCH OF
THE EASTERN UNITED STATES ON THURSDAY. A LOW PRESSURE SYSTEM IN
THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE EAST ACROSS THE
GREAT LAKES ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 200 PM EST WEDNESDAY...
A SHORTWAVE LOCATED IN KENTUCKY AROUND 18Z WILL ROTATE EAST
AROUND THE BASE OF THE UPPER TROUGH THIS AFTERNOON INTO TONIGHT.
THE UPPER TROF AXIS IS FORECAST TO PIVOT NORTHEAST
TONIGHT...ALLOWING SOME RIDGING AND RISING 500 MB HEIGHTS. SFC
COLD FRONT ACROSS THE OHIO VALLEY THIS AFTERNOON WILL WEAKEN AND
DISSIPATE OVER THE MID ATLANTIC REGION BY THURSDAY MORNING. THE
HIRESW-ARW-E...RNK- WRFARW...GFS AND NAM SHOWED ISOLATED SCATTERED
SHOWERS ACROSS THE WESTERN MOUNTAINS. THE ECMWF...RAP AND HRRR ARE
LESS IMPRESSED FOR ACTIVITY. FOR TONIGHT...WILL MAINTAIN SCATTERED
SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW ACCUMULATIONS WILL
BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE OF SNOW WILL OCCUR
ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY OF WEST VIRGINIA.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE MID TEENS IN THE
NORTHWEST MOUNTAINS TO THE MID 20S IN THE SOUTHEAST.
ANY LINGERING MOUNTAIN SNOW SHOWERS AND SNOW FLURRIES SHOULD BE
GONE THURSDAY MORNING...AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST. SOME LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST
UNTIL THE AFTERNOON WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS
OVERHEAD. EAST OF THE BLUE RIDGE...LOOK FOR PLENTY OF SUNSHINE.
HIGH TEMPERATURES WILL VARY FROM THE LOWER 30S IN THE NORTHWEST
MOUNTAINS TO THE UPPER 40S IN THE PIEDMONT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 245 PM EST WEDNESDAY
A CLASSIC WEDGE WILL TAKE RESIDENCE OVER THE EAST COAST THURSDAY
NIGHT INTO FRIDAY. THE MID ATLANTIC PORTION OF THE WEDGE WILL
DRIFT OUT TO SEA AS A NORTHERN STREAM DISTURBANCE TRACKS EAST OF
THE GREAT LAKES FRIDAY NIGHT. THIS DISTURBANCE WILL PUSH A WEAK
COLD FRONT OVER THE AREA EARLY SATURDAY. THE SOUTHERN PORTION OF
THIS WEDGE WILL REMAIN OVER THE SOUTHEASTERN US WHILE BLOCKING THE
GULF. THE FRONT COMING ACROSS EARLY SATURDAY WILL BE MOISTURE
STARVED WITH A FEW LIGHT RAIN SHOWERS HITTING THE WESTERN SLOPES
AND ONLY AN INCREASE IN CLOUDS ELSEWHERE. ZONAL FLOW BECOMES
ESTABLISHED BY SATURDAY AFTERNOON AND WILL REMAIN THROUGH THE
WEEKEND.
BEING AHEAD OF THE FRONT FRIDAY...TEMPERATURES WILL WARM AT OR
ABOVE NORMAL WITH READINGS IN THE M/U 40S WEST TO L50S EAST.
DESPITE THE PASSING OF A WEAK FRONT SATURDAY
MORNING...TEMPERATURES WILL MODERATE WARMER THAN NORMAL WITH
WIDESPREAD 50S ACROSS THE AREA TO THE LOWER 60S IN THE PIEDMONT.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 115 PM EST WEDNESDAY
THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH
THE WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST
FROM THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A
STALLED BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH
CAROLINA. FOR THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT
WILL PASS OVER THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME
LIGHT PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE.
WITH ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE
50S AND 60S.
ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH
ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG
THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES.
MONDAY NIGHT INTO TUESDAY...MODEL GUIDANCE IS NOT IN AGREEMENT
WITH TIMING OF THE NEXT LOW PRESSURE SYSTEM BRINGING POTENTIAL FOR
RAIN AND SNOW TO THE AREA. A HIGH PRESSURE WEDGES DOWN ALONG THE
EASTERN SLOPES OF THE BLUE RIDGE MONDAY EVENING. THE STRENGTH OF
THE WEDGE WILL DEPEND ON WHAT TYPE OF PRECIP TO EXPECT OVERNIGHT.
THE WEDGE MOVES OUT QUICKLY TUESDAY MORNING RETURNING TO RAIN BY
THE AFTERNOON.
THE UPPER LEVEL TROUGH DEEPENS THROUGH THE TENNESSEE VALLEY IT
BECOMES NEGATIVE-TILTED WITH CONVECTIVE SHOWERS TRACKING EAST OF
THE BLUE RIDGE TO THE COASTAL PIEDMONT. TEMPERATURES WILL REMAIN
WELL ABOVE NORMAL MONDAY AND TUESDAY FOR ALL PRECIPITATION TO STAY
LIQUID. THE FRONT WILL PASS TO THE EAST TUESDAY NIGHT...WITH
UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY MORNING...ALL PRECIP
SHOULD EXIT THE REGION BY WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS
IN.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 1243 PM EST WEDNESDAY...
SCT TO BKN MVFR CLOUDS EXPECTED IN KBLF...KLWB AND KBCB THIS
AFTERNOON INTO TONIGHT. VFR CONDITIONS WILL CONTINUE AT
KDAN...KLYH AND KROA INTO TONIGHT.
NORTHWEST WINDS AND LOW LEVEL MOISTURE WILL CREATE MVFR CLOUDS
FOR THE MOUNTAINS THIS AFTERNOON AND TONIGHT. UPSLOPE RAIN AND
SNOW SHOWERS ARE EXPECTED THIS AFTERNOON THROUGH EARLY THURSDAY
MORNING...BUT A SMALL CHANCE THAT PRECIPITATION WILL IMPACT KLWB
OR KBLF. WESTERN GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA WILL
HAVE THE BEST CHANCE FOR SNOW SHOWERS. ON THURSDAY...HIGH PRESSURE
WILL MOVE OVERHEAD AND BRING A RETURN TO VFR CONDITIONS.
HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING TAF
PERIOD.
EXTENDED DISCUSSION...
VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY. ANOTHER LOW
PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD
SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY
NIGHT AND SATURDAY.
&&
.HYDROLOGY...
AS OF 1252 PM EST TUESDAY...
STAGES ARE FALLING ON THE UPPER DAN RIVER FROM DANVILLE UPSTREAM
BUT CONTINUING TO RISE DOWNSTREAM. EXPECT MINOR FLOODING OF
LOWLAND AREAS. STAGES ALSO CONTINUE TO CLIMB ALONG THE LOWER
ROANOKE RIVER IMPACTING LOWLANDS AND SEVERAL ROADS NEAR THE RIVER.
FLOOD WARNING CONTINUES FOR THE FOLLOWING RIVERS IN
VIRGINIA...ROANOKE RIVER AT RANDOLPH AFFECTING CHARLOTTE AND
HALIFAX COUNTIES, DAN RIVER AT PACES AFFECTING HALIFAX COUNTY AND
DAN RIVER AT SOUTH BOSTON AFFECTING HALIFAX COUNTY. CHECK LATEST
FLS FOR FLOOD DETAILS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK
NEAR TERM...KK
SHORT TERM...RCS
LONG TERM...RCS/LC
AVIATION...AMS/KK
HYDROLOGY...KK/PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1255 PM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL CROSS THROUGH THE OHIO VALLEY TODAY AND
TONIGHT...THEN WILL DISSIPATE OVER THE MID ATLANTIC REGION BY
THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND
WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW
PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE
EAST ACROSS THE GREAT LAKES ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST WEDNESDAY...
RAISED HIGH TEMPERATURES UP A COUPLE OF DEGREES IN THE EAST FOR
THIS AFTERNOON.
AS OF 955 AM EST WEDNESDAY...
SHORTWAVE WILL ROTATE AROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT
NORTHEAST TONIGHT. THE HIRESW-ARW EAST...RNK WRF ARW AND RAP
SUPPORT SNOW SHOWERS AND SNOW FLURRIES IN THE WESTERN MOUNTAINS.
THIS MORNING HRRR IS LESS IMPRESSED WITH SNOW SHOWERS FOR THIS
AFTERNOON COMPARED TO OTHER HIRES SOLUTIONS. WILL MAINTAIN
SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW
ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE
OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY
OF WEST VIRGINIA. ADJUSTED TEMPERATURES WITH LATEST OBS AND MODEL
TRENDS FOR THIS MORNING INTO THIS AFTERNOON. WILL HOLD WITH
CURRENT HIGH TEMPERATURES FOR THIS AFTERNOON...BUT COULD BE A
COUPLE OF DEGREES HIGHER IN SOUTHSIDE WITH SUNSHINE. MORE CHANGES
LATER TODAY...
AS OF 655 AM EST WEDNESDAY...
PRECIPITATION HAS ENDED ACROSS THE FORECAST AREA AND CLOUDS WERE
ALREADY CLEARING OUT EAST OF THE BLUE RIDGE.
NEXT SHORT WAVE WILL ROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON THEN TROF AXIS MOVES EAST AND 500 MB HEIGHTS RISE OVER THE
FORECAST AREA TONIGHT. AT THE SURFACE A WEAK AREA OF LOW PRESSURE
OVER THE CAROLINAS WILL MOVE EAST THIS MORNING. HIGH PRESSURE BUILDS
IN TONIGHT.
LOW LEVEL MOISTURE WITH THE UPSTREAM SHORT WAVE ARRIVE IN THE
MOUNTAINS THIS MORNING. BY MIDNIGHT...ENOUGH DRY AIR COMES IN TO END
THE UPSLOPE SHOWERS AND ON THURSDAY FOR CLEARING IN THE MOUNTAINS.
NO MAJOR ADJUSTMENTS FROM TEMPERATURE GUIDANCE TODAY OR TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 350 AM EST WEDNESDAY...
ANY LINGERING MOUNTAIN SNOW SHOWERS SHOULD BE GONE BY THURSDAY
MORNING...AS HIGH PRESSURE ARRIVES FROM THE NORTHWEST. SOME
LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON
WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE
BLUE RIDGE...IT WILL BE MOSTLY SUNNY SKIES WITH TEMPERATURES
CLIMBING TOWARD THE MID TO UPPER 40S. AS THE HIGH SAGS SOUTHWARD
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE ON THURSDAY NIGHT...CLEAR
SKIES AND CALM WINDS SHOULD ALLOW GOOD RADIATIONAL COOLING TO DROP
LOWS BELOW FREEZING FOR MOST LOCATIONS.
A SOUTH TO SOUTHEAST BREEZE WILL PICK UP DURING FRIDAY...AS THE CWA
ENTERS A ZONE OF WARM AIR ADVECTION WITH HIGH PRESSURE OFFSHORE.
UPPER LEVEL RIDGING SHOULD ALSO TAKE PLACE OVER THE EASTERN UNITED
STATES. ALTHOUGH SOME PASSING CIRRUS CLOUDS MAY DAMPER THE FULL
POTENTIAL OF DIURNAL HEATING...HIGH TEMPERATURES WILL REACH THE MID
40S TO THE MID 50S. BY FRIDAY NIGHT...A PASSING DISTURBANCE MOVING
EASTWARD OVER SOUTHERN ONTARIO IN CANADA MAY LEAVE A TONGUE OF
SHALLOW MOISTURE STRETCHING SOUTHWARD OVER THE APPALACHIAN
MOUNTAINS. WITH LOWS HOLDING ABOVE FREEZING DUE TO CLOUD
COVER...ONLY A CHANCE OF LIGHT RAIN IS ANTICIPATED FOR THE WESTERN
SLOPES. IN ADDITION...SOUTH WINDS SHOULD INCREASE OVERNIGHT ALONG
THE HIGHEST RIDGETOPS...AND COULD POSSIBLY GUST UP TO 30 MPH.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 PM EST TUESDAY
THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE
WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM
THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED
BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR
THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER
THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT
PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. THIS
FRONT WILL STALL OVER THE PIEDMONT AND BECOME A LEE TROUGH. WITH
ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S
AND 60S.
ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH
ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG
THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO
TUESDAY...THE UPPER LEVEL TROUGH WILL MOVE TO THE OHIO VALLEY WHILE
LOW PRESSURE IN THE TENNESSEE VALLEY BUCKLES THE SOUTHERN BOUNDARY
NORTH...LINKING UP WITH THE LEE TROUGH OVER THE PIEDMONT.
THE UPPER LEVEL TROUGH BECOMES NEGATIVE-TILTED WITH CONVECTIVE
SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR
ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST
TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1243 PM EST WEDNESDAY...
SCT TO BKN MVFR CLOUDS EXPECTED IN KBLF...KLWB AND KBCB
THIS AFTERNOON INTO TONIGHT. VFR CONDITIONS WILL CONTINUE AT
KDAN...KLYH AND KROA INTO TONIGHT.
NORTHWEST WINDS AND LOW LEVEL MOISTURE WILL CREATE MVFR CLOUDS
FOR THE MOUNTAINS THIS AFTERNOON AND TONIGHT. UPSLOPE RAIN AND
SNOW SHOWERS ARE EXPECTED THIS AFTERNOON THROUGH EARLY THURSDAY
MORNING...BUT A SMALL CHANCE THAT PRECIPITATION WILL IMPACT KLWB
OR KBLF. WESTERN GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA
WILL HAVE THE BEST CHANCE FOR SNOW SHOWERS. ON THURSDAY...HIGH
PRESSURE WILL MOVE OVERHEAD AND BRING A RETURN TO VFR CONDITIONS.
HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING TAF
PERIOD.
EXTENDED DISCUSSION...
VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY. ANOTHER LOW
PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD
SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY
NIGHT AND SATURDAY.
&&
.HYDROLOGY...
AS OF 1252 PM EST TUESDAY...
STAGES ARE FALLING ON THE UPPER DAN RIVER FROM DANVILLE UPSTREAM BUT CONTINUING
TO RISE DOWNSTREAM. EXPECT MINOR FLOODING OF LOWLAND AREAS. STAGES ALSO
CONTINUE TO CLIMB ALONG THE LOWER ROANOKE RIVER IMPACTING LOWLANDS AND SEVERAL
ROADS NEAR THE RIVER. FLOOD WARNING CONTINUES FOR THE FOLLOWING RIVERS IN
VIRGINIA...ROANOKE RIVER AT RANDOLPH AFFECTING CHARLOTTE AND
HALIFAX COUNTIES, DAN RIVER AT PACES AFFECTING HALIFAX COUNTY AND DAN
RIVER AT SOUTH BOSTON AFFECTING HALIFAX COUNTY. CHECK LATEST FLS
FOR FLOOD DETAILS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PW
LONG TERM...RCS
AVIATION...AMS/KK
HYDROLOGY...KK/PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1243 PM EST WED FEB 17 2016
.SYNOPSIS...
A COLD FRONT WILL CROSS THROUGH THE OHIO VALLEY TODAY AND
TONIGHT...THEN WILL DISSIPATE OVER THE MID ATLANTIC REGION BY
THURSDAY MORNING. HIGH PRESSURE BUILDS IN BEHIND THE FRONT AND
WILL COVER MUCH OF THE EASTERN UNITED STATES ON THURSDAY. A LOW
PRESSURE SYSTEM IN THE UPPER MISSISSIPPI VALLEY FRIDAY WILL MOVE
EAST ACROSS THE GREAT LAKES ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST WEDNESDAY...
RAISED HIGH TEMPERATURES UP A COUPLE OF DEGREES IN THE EAST FOR
THIS AFTERNOON.
AS OF 955 AM EST WEDNESDAY...
SHORTWAVE WILL ROTATE AROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON INTO TONIGHT. THE UPPER TROF AXIS IS FORECAST TO PIVOT
NORTHEAST TONIGHT. THE HIRESW-ARW EAST...RNK WRF ARW AND RAP
SUPPORT SNOW SHOWERS AND SNOW FLURRIES IN THE WESTERN MOUNTAINS.
THIS MORNING HRRR IS LESS IMPRESSED WITH SNOW SHOWERS FOR THIS
AFTERNOON COMPARED TO OTHER HIRES SOLUTIONS. WILL MAINTAIN
SCATTERED SNOW SHOWERS IN THE WESTERN MOUNTAINS. ANY SNOW
ACCUMULATIONS WILL BE LIGHT AND LESS THAN AN INCH. THE BEST CHANCE
OF SNOW WILL OCCUR ALONG THE WESTERN SLOPES OF GREENBRIER COUNTY
OF WEST VIRGINIA. ADJUSTED TEMPERATURES WITH LATEST OBS AND MODEL
TRENDS FOR THIS MORNING INTO THIS AFTERNOON. WILL HOLD WITH
CURRENT HIGH TEMPERATURES FOR THIS AFTERNOON...BUT COULD BE A
COUPLE OF DEGREES HIGHER IN SOUTHSIDE WITH SUNSHINE. MORE CHANGES
LATER TODAY...
AS OF 655 AM EST WEDNESDAY...
PRECIPITATION HAS ENDED ACROSS THE FORECAST AREA AND CLOUDS WERE
ALREADY CLEARING OUT EAST OF THE BLUE RIDGE.
NEXT SHORT WAVE WILL ROUND THE BASE OF THE EASTERN TROF THIS
AFTERNOON THEN TROF AXIS MOVES EAST AND 500 MB HEIGHTS RISE OVER THE
FORECAST AREA TONIGHT. AT THE SURFACE A WEAK AREA OF LOW PRESSURE
OVER THE CAROLINAS WILL MOVE EAST THIS MORNING. HIGH PRESSURE BUILDS
IN TONIGHT.
LOW LEVEL MOISTURE WITH THE UPSTREAM SHORT WAVE ARRIVE IN THE
MOUNTAINS THIS MORNING. BY MIDNIGHT...ENOUGH DRY AIR COMES IN TO END
THE UPSLOPE SHOWERS AND ON THURSDAY FOR CLEARING IN THE MOUNTAINS.
NO MAJOR ADJUSTMENTS FROM TEMPERATURE GUIDANCE TODAY OR TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 350 AM EST WEDNESDAY...
ANY LINGERING MOUNTAIN SNOW SHOWERS SHOULD BE GONE BY THURSDAY
MORNING...AS HIGH PRESSURE ARRIVES FROM THE NORTHWEST. SOME
LINGERING STRATOCUMULUS CLOUDS MAY STILL PERSIST UNTIL THE AFTERNOON
WEST OF THE BLUE RIDGE...WHEN THE HIGH BUILDS OVERHEAD. EAST OF THE
BLUE RIDGE...IT WILL BE MOSTLY SUNNY SKIES WITH TEMPERATURES
CLIMBING TOWARD THE MID TO UPPER 40S. AS THE HIGH SAGS SOUTHWARD
ALONG THE EASTERN SLOPES OF THE BLUE RIDGE ON THURSDAY NIGHT...CLEAR
SKIES AND CALM WINDS SHOULD ALLOW GOOD RADIATIONAL COOLING TO DROP
LOWS BELOW FREEZING FOR MOST LOCATIONS.
A SOUTH TO SOUTHEAST BREEZE WILL PICK UP DURING FRIDAY...AS THE CWA
ENTERS A ZONE OF WARM AIR ADVECTION WITH HIGH PRESSURE OFFSHORE.
UPPER LEVEL RIDGING SHOULD ALSO TAKE PLACE OVER THE EASTERN UNITED
STATES. ALTHOUGH SOME PASSING CIRRUS CLOUDS MAY DAMPER THE FULL
POTENTIAL OF DIURNAL HEATING...HIGH TEMPERATURES WILL REACH THE MID
40S TO THE MID 50S. BY FRIDAY NIGHT...A PASSING DISTURBANCE MOVING
EASTWARD OVER SOUTHERN ONTARIO IN CANADA MAY LEAVE A TONGUE OF
SHALLOW MOISTURE STRETCHING SOUTHWARD OVER THE APPALACHIAN
MOUNTAINS. WITH LOWS HOLDING ABOVE FREEZING DUE TO CLOUD
COVER...ONLY A CHANCE OF LIGHT RAIN IS ANTICIPATED FOR THE WESTERN
SLOPES. IN ADDITION...SOUTH WINDS SHOULD INCREASE OVERNIGHT ALONG
THE HIGHEST RIDGETOPS...AND COULD POSSIBLY GUST UP TO 30 MPH.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 PM EST TUESDAY
THE NORTHERN AND SOUTHERN STREAMS WILL REMAIN SEPARATED THROUGH THE
WEEKEND. DISTURBANCES IN THE NORTHERN STREAM WILL TRACK EAST FROM
THE GREAT LAKES TO NORTHEASTERN US. ACROSS THE SOUTH...A STALLED
BOUNDARY WILL KEEP RAIN FROM EASTERN TEXAS TO SOUTH CAROLINA. FOR
THE IMMEDIATE AREA...A WEAK MOISTURE STARVED FRONT WILL PASS OVER
THE REGION FRIDAY NIGHT INTO SATURDAY MORNING. SOME LIGHT
PRECIPITATION MAY FALL ALONG WESTERN SLOPES...DRY ELSEWHERE. THIS
FRONT WILL STALL OVER THE PIEDMONT AND BECOME A LEE TROUGH. WITH
ZONAL FLOW OVER THE WEEKEND...TEMPERATURES WILL WARM INTO THE 50S
AND 60S.
ON MONDAY...THE NORTHERN STREAM WILL SEND AN UPPER LEVEL TROUGH
ACROSS THE PLAINS. WAVES OF LOW PRESSURE WILL FORM AND TRACK ALONG
THE STALLED BOUNDARY ACROSS THE SOUTHERN STATES. MONDAY NIGHT INTO
TUESDAY...THE UPPER LEVEL TROUGH WILL MOVE TO THE OHIO VALLEY WHILE
LOW PRESSURE IN THE TENNESSEE VALLEY BUCKLES THE SOUTHERN BOUNDARY
NORTH...LINKING UP WITH THE LEE TROUGH OVER THE PIEDMONT.
THE UPPER LEVEL TROUGH BECOMES NEGATIVE-TILTED WITH CONVECTIVE
SHOWERS TRACKING EAST OF THE BLUE RIDGE TO THE COASTAL PIEDMONT.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL MONDAY AND TUESDAY FOR
ALL PRECIPITATION TO STAY LIQUID. THE FRONT WILL PASS TO THE EAST
TUESDAY NIGHT...WITH UPSLOPE SNOW SHOWERS LIKELY INTO WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 1243 PM EST WEDNESDAY...
SCT TO BKN MVFR CLOUDS EXPECTED IN KBLF...KLWB AND KBCB
THIS AFTERNOON INTO TONIGHT. VFR CONDITIONS WILL CONTINUE AT
KDAN...KLYH AND KROA INTO TONIGHT.
NORTHWEST WINDS AND LOW LEVEL MOISTURE WILL CREATE MVFR CLOUDS
FOR THE MOUNTAINS THIS AFTERNOON AND TONIGHT. UPSLOPE RAIN AND
SNOW SHOWERS ARE EXPECTED THIS AFTERNOON THROUGH EARLY THURSDAY
MORNING...BUT A SMALL CHANCE THAT PRECIPITATION WILL IMPACT KLWB
OR KBLF. WESTERN GREENBRIER COUNTY IN SOUTHEAST WEST VIRGINIA
WILL HAVE THE BEST CHANCE FOR SNOW SHOWERS. ON THURSDAY...HIGH
PRESSURE WILL MOVE OVERHEAD AND BRING A RETURN TO VFR CONDITIONS.
HIGH CONFIDENCE IN CEILINGS...VISIBILITIES AND WINDS DURING TAF
PERIOD.
EXTENDED DISCUSSION...
VFR CONDITIONS PREVAIL AT ALL SITES THROUGH FRIDAY. ANOTHER LOW
PRESSURE SYSTEM SHOULD PASS TO THE NORTH ON SATURDAY. IT COULD
SPARK SOME MOUNTAIN RAIN SHOWERS AND LOWER CEILINGS ON FRIDAY
NIGHT AND SATURDAY.
&&
.HYDROLOGY...
AS OF 303 PM EST TUESDAY...
STORM TOTAL PRECIPITATION (2-DAY) IN THE FORM OF SNOW AND RAIN
(MUCH OF IT FREEZING) HAS RANGED GENERALLY FROM 1 TO 2.5 INCHES
WITH UP TO 3+ INCHES ACROSS PORTIONS OF BEDFORD...EASTERN FRANKLIN
AND SOUTHERN BOTETOURT COUNTIES...ALTHOUGH THIS IS RADAR INDICATED
AND NOT WELL CORROBORATED BY RAIN GAGES. WITH MUCH OF THE
OVERNIGHT RAIN FALLING ONTO AND INTO A SUBSTANTIAL SNOWPACK THE
HYDROLOGIC RESPONSE HAS BEEN SOMEWHAT MUTED.
FORECASTS ON THE JAMES HAVE BEEN REDUCED SLIGHTLY FROM YESTERDAY
AND ARE NOW EXPECTING RISES TO BELOW ACTION STAGE WITH THE
EXCEPTION OF SCOTTSVILLE. BOTH THE NEW AND GREENBRIER WILL SEE
VERY MODEST RISES DUE TO THE SNOWPACK ABSORPTION AND ONLY SLOW
MELT OVER COMING DAYS. THE FORECAST POINTS SHOWING RFC GUIDANCE
ABOVE FLOOD STAGE ARE ALONG THE ROANOKE RIVER AT RANDOLPH...AND
DAN RIVER AT PACES AND SOUTH BOSTON.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...PW
LONG TERM...RCS
AVIATION...AMS/KK
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 PM CST WED FEB 17 2016
.SHORT TERM...(THIS EVENING THROUGH THURSDAY EVENING)
ISSUED AT 331 PM CST WED FEB 17 2016
CLOUDS WILL INCREASE OVERNIGHT AS THE STATIONARY FRONT THROUGH THE
DAKOTAS AND IOWA STARTS TO SHIFT NORTHEAST. THERE COULD BE A FEW
FLURRIES ASSOCIATED WITH THAT BAND VIA VERY WEAK FRONTOGENESIS. DO
NOT HAVE THAT IN THE FORECAST AT THIS TIME AS IT SEEMS LIKE A
SMALL PROBABILITY. THESE CLOUDS SIGNIFY THE FIRST WARM/MOIST AIR
PUSH FROM THE SOUTHWEST.
SOUTHERLY FLOW AND GULF MOISTURE THEN STARTS TO MOVE TOWARD THE
REGION FROM THE SOUTH. BY LATE IN THE DAY THURSDAY...THE SURFACE-
BASED CLOUD LAYER WILL HAVE DEEPENED TO ABOUT 1.5-2 KMS...WHICH
STARTS TO REALLY INCREASE THE -DZ/-RA CHANCES FROM THE LAYER
SHOULD VERTICAL MOTION EXIST. WARM ADVECTION IN THE LOW-LEVELS AND
SOME LOW-LEVEL MOISTURE TRANSPORT CONVERGENCE INCREASE IN THE LATE
AFTERNOON WHICH SHOULD TRIGGER SOME PRECIPITATION PRODUCTION.
REALLY LIKE THE AGREEMENT ON THIS IN THE DETERMINISTIC MODELS...WITH
ABOUT 4-5 UB/S OF UPWARD MOTION IN THE 0-2KM LAYER...WITH A SLIGHT
PREFERENCE TOWARD A DEEPER MOIST LAYER IN WI. BY LATER THU
AFTERNOON...ONLY HAVE SOME NEAR FREEZING TEMPERATURES AND SUB-
FREEZING DEWPOINTS IN NORTHCENTRAL WI...SO HAVE KEPT FZDZ MENTION
THERE. THIS WOULD LAST THROUGH THE EVENING...BUT WARMING
TEMPERATURES OVERNIGHT SHOULD CONVERT ANY FZDZ TO DZ. HAVE RAISED
THE PRECIPITATION CHANCES ACROSS THE AREA SOMEWHAT BUT PROBABLY
NOT ENOUGH...AND IF SIGNALS CONTINUE AS SEEN TODAY...THIS TREND
WILL NEED TO CONTINUE FOR DZ.
.LONG TERM...(LATER THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 331 PM CST WED FEB 17 2016
SOME WARM ADVECTION AND WEAK LIFT CONTINUES INTO LATER THURSDAY
NIGHT AND DRIZZLE MAY BE AROUND AS A STRONG SHORTWAVE TROUGH
APPROACHES THE AREA. THIS TROUGH IS CURRENTLY OFF THE WEST COAST
WITH VIGOROUS OPEN CELL CONVECTION PER GOES IMAGERY. BY EARLY
FRIDAY MORNING...MANY ATMOSPHERIC FORCING MECHANISMS ARE IN
PLACE ASSOCIATED WITH THIS TROUGH...PREFERABLE CYCLONIC SHEAR
SIDE OF VIGOROUS-WELL CURVED-COMPACT 125KT 300MB JET...300-500MB
QVECTOR CON/DIVERGENCE DIPOLE...LOW-LEVEL WARM ADVECTION AND
THETAE CONVERGENCE / MOISTURE TRANSPORT CONVERGENCE /850MB/...AND
POSSIBLY ELEVATED CAPE OF 100-300 J/KG PER 17.12Z NAM. GOT YOUR
FORCING CHECKLIST HANDY...CUZ THIS ONE HAS MANY CHECK BOXES.
BUT...INTERESTINGLY...THE DETERMINISTIC GUIDANCE REALLY TARGETS
THE SHORTWAVE TROUGH CENTER AND NORTHWARD FOR PRECIPITATION /I-90/.
WHILE CHANCES WILL DECREASE SOUTHWARD...IT IS A CASE WHERE TOO
MANY MODEL FORCING SIGNALS DONT MATCH THE PRECIPITATION SOLUTIONS.
SO...HAVE BOUNCED RAIN CHANCES UP EVERYWHERE FOR LATE THURSDAY
NIGHT AND FRIDAY MORNING. WITH CAPE IN PLACE AND TROUGH
FORCING...HAVE LEFT THUNDER IN THE FORECAST NORTH NEAR/NORTH OF
I-90. WAVE INGREDIENTS ARE VIGOROUS PER THE MODEL ENVIRONMENT TO
SATURATE AND INITIATE THE INSTABILITY.
POST FRONTALLY FRIDAY AFTERNOON...WEAKLY SUBSIDENT CONDITIONS AND
DRYING WILL MOVE IN WITH SOME WEAK COLD ADVECTION KICKING IN LATER
IN THE DAY. DETERMINISTIC MODELS ARENT HOG WILD WITH BOUNDARY
LAYER LAPSE RATES PER VERY WEAK COLD ADVECTION. A SURFACE PRESSURE
RISE/FALL COUPLET OF +5/-5 IN 3 HOURS MOVES THROUGH FRIDAY MORNING
LEAVING THE AFTERNOON UNDER A MODERATE PRESSURE GRADIENT. 17.12Z
GFS SEEMS TOO AGGRESSIVE WITH LOW-LEVEL WIND FIELD /AGAIN/...AND
A BETTER CONSENSUS IS ABOUT 35-40 KTS AT THE TOP OF THE MIXED
LAYER PROVIDED SUN IS SEEN. THUS...WIND FORECAST OF GUSTS TO 40-45
MPH SEEMS APPROPRIATE WITH A WIND ADVISORY POSSIBLY NEEDED FOR
THE WESTERN FORECAST AREA FRIDAY. CONFIDENCE IS MODERATE ON THIS
ADVISORY.
SATURDAY THROUGH WEDNESDAY...A SERIES OF WEAK SHORTWAVES WILL MOVE
THROUGH AND SUNDAYS SYSTEM WILL MARK THE RETURN TO MORE NORTHWEST
FLOW AND NEAR NORMAL TEMPERATURES. SEEMS THERE IS SOME CONSISTENT
SIGNAL ON SUNDAY HAVING PRECIPITATION BUT WILL LET THE MODELS SORT
THEMSELVES OUT A BIT MORE BEFORE RAISING PRECIPITATION CHANCES.
NO SIGNIFICANT WEATHER SEEN IN THE EARLY PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1126 AM CST WED FEB 17 2016
THE MAIN CONCERN DURING THIS PERIOD IS WHETHER MVFR/IFR CEILINGS
WILL DEVELOP OVERNIGHT INTO THURSDAY MORNING. AS THE AREA OF HIGH
PRESSURE CURRENTLY OVER THE AREA MOVES OFF TO THE EAST...THE FLOW
WILL BECOME SOUTH AHEAD A DEVELOPING AREA OF LOW PRESSURE IN THE
LEE OF THE CANADIAN ROCKIES. A RIBBON OF MOISTURE/CLOUDS CURRENTLY
EXTENDS FROM NORTH DAKOTA SOUTHEAST ACROSS IOWA INTO ILLINOIS.
CEILINGS IN THIS MOISTURE FIELD ARE MVFR ACROSS THE DAKOTAS BUT
BECOME VFR FOR THE MOST PART ACROSS IOWA INTO ILLINOIS. THE 17.15Z
RAP AND HRRR AND THE 17.12Z NAM AND HI-RES NMM ALL INDICATE THESE
MVFR CEILINGS EXTEND ALL THE WAY ACROSS IOWA AND THEN WILL LIFT
NORTH INTO THE AREA OVERNIGHT AS THE FLOW TURNS TO THE SOUTH.
HOWEVER...THE 17.12Z HI-RES ARW AND 17.09Z SREF SEEM TO HAVE A
BETTER HANDLE ON CURRENT CLOUD TRENDS AND SUGGEST THE MVFR CLOUD
DECK MAY LIFT MORE INTO MINNESOTA AND GO BY TO THE NORTH OR IF THE
LOWER CEILINGS DO COME...IT MAY BE LATER THAN CURRENT EXPECTED.
FOR NOW...WILL NOT TOTALLY BACK OUT OF THE IDEA OF LOWER CLOUDS
COMING INTO THE TAF SITES...BUT WILL DELAY THE ARRIVAL BACK CLOSER
TO 12Z AND KEEP BOTH SITES IN THE MVFR CATEGORY.
&&
.HYDROLOGY...
ISSUED AT 331 PM CST WED FEB 17 2016
MESSAGE HERE IS STILL THE SAME. SIGNIFICANT SNOW MELT WILL TAKE
PLACE STARTING FRIDAY WHICH WILL CAUSE A 1-2 INCH EQUIVALENT
RAINFALL TO ENTER THE RIVERS FROM FRIDAY/SATURDAY. THE SNOW PACK
WILL NEED TO WARM A BIT THU/FRI BEFORE SIGNIFICANT MELTING...SO
SATURDAY SHOULD REALLY MELT THE SNOW PACK. SOME OF THE MODEL
GUIDANCE COMPLETELY MELTS ITS SNOW...SO IT COULD HAPPEN THIS
WEEKEND FOR MANY.
OVERALL WE WILL LIKELY SEE RIVER RISES. THIS MAY CAUSE SOME
BREAKUP OF ICE ON STREAMS/RIVERS WITH THE POSSIBILITY OF A FEW ICE
JAMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
HYDROLOGY...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1126 AM CST WED FEB 17 2016
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 334 AM CST WED FEB 17 2016
FORECAST CHALLENGE IN THE SHORT TERM WILL BE INCREASING DRIZZLE/
FREEZING DRIZZLE CHANCE THURSDAY INTO THURSDAY NIGHT. ALSO SLIGHT
THUNDER CHANCE LATE THURSDAY NIGHT WITH POTENT INCOMING LOW
PRESSURE.
CURRENT SURFACE MAP HAS A RIDGE OF HIGH PRESSURE EXTENDING FROM
MN/CANADIAN BORDER...DOWN INTO IA/MO. THIS WAS PRODUCING MOSTLY
CLEAR SKIES AND TEMPERATURE (AS OF 2 AM) RANGING FROM THE SINGLE
DIGITS ABOVE ZERO ACROSS NORTH CENTRAL WI AND TEENS ELSEWHERE.
RELATIVELY QUIET PERIOD TODAY THROUGH TONIGHT AS HIGH PRESSURE HOLDS
ON ACROSS THE AREA. WILL SEE INCREASING SOUTHERLY WINDS ON THE
BACKSIDE OF THE HIGH TONIGHT ALONG WITH INCREASING CLOUD COVER AS
MOISTURE MAKES ITS WAY IN AHEAD OF DEEP LOW PRESSURE MOVING OUT OF
THE NORTHERN ROCKIES.
LOW LEVEL MOISTURE ADVECTION KICKS IN WITH FERVOR THURSDAY...
INCREASING STRATUS CLOUD COVER OVER THE REGION. NAM BUFKIT SHOWING A
GOOD DRIZZLE SOUNDING AS LIFT/TURNING IN WARM AIR ADVECTION TAKES
PLACE. COULD SEE SOME FREEZING DRIZZLE MAINLY NORTHEAST OF I-94 BY
AFTERNOON...INTO THURSDAY EVENING AS TEMPERATURES HOVER IN THE
LOWER/MIDDLE 30S. OTHERWISE...LOOK FOR HIGHS THURSDAY ACROSS THE
REST OF THE AREA IN THE UPPER 30S/NEAR 40.
LATER THURSDAY NIGHT...AS THE DEEP LOW PRESSURE SYSTEM MAKES ITS WAY
ACROSS THE DAKOTAS INTO MN...A WARM FRONT WILL PUSH NORTHWARD TO
NEAR THE I-94 CORRIDOR BY MIDNIGHT. INCREASING 850MB TRANSPORT/LIFT
INTO AND OVER THE WARM FRONT WILL PRODUCE A GOOD CHANCE OF SHOWERS
AND EVEN A CHANCE OF A THUNDERSTORM OR TWO AS 0-3KM MUCAPE INCREASES
TO NEARLY 500J/KG. OTHERWISE...TEMPERATURES WILL BE ON THE RISE
DURING THE OVERNIGHT HOURS...REACHING THE UPPER 30S/LOWER 40S BY
DAYBREAK.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 334 AM CST WED FEB 17 2016
FRIDAY WILL BE AN INTERESTING DAY WITH MULTIPLE METEOROLOGICAL
FACETS AS THE DEEP LOW/COLD FRONT MAKE THEIR WAY THROUGH THE REGION.
1. VERY MILD START TO THE DAY WITH TEMPERATURES WELL INTO THE
40S...POSSIBLY A FEW LOWER 50S ACROSS NORTHEAST IA/SOUTHWEST WI. 2.
SCATTERED SHOWERS/ISOLATED THUNDER WILL BE SEEN IN THE MORNING WITH
THE COLD FRONTAL PASSAGE. 3. WINDY BY AFTERNOON IN TIGHT PRESSURE
GRADIENT BEHIND THE DEPARTING LOW/COLD AIR ADVECTION. PLAN ON
WESTERLY WINDS IN THE 20-30 MPH RANGE WITH GUSTS APPROACHING 40-45
MPH...ESPECIALLY ACROSS THE WIND PRONE AREAS OF SOUTHEAST
MN/NORTHEAST IA. CANNOT RULE OUT THE NEED FOR AN EVENTUAL WIND
HEADLINE.
HIGH-ZONAL PACIFIC FLOW SETS UP FOR SATURDAY INTO SUNDAY. A WEAK
TROUGH WITHIN THIS FLOW PRODUCES A CHANCE OF RAIN/SNOW MIX SUNDAY.
OTHERWISE...MILD CONDITIONS TO CONTINUE WITH HIGHS SATURDAY MOSTLY
IN THE 40S AND UPPER 30S TO MIDDLE 40S SUNDAY.
SLIGHT COOLING LOOKS TO TAKE PLACE MONDAY INTO TUESDAY AS MID LEVEL
TROUGH STARTS TO CARVE OUT ACROSS CANADA/CENTRAL CONUS. PLAN ON
HIGHS MONDAY AND TUESDAY MAINLY IN THE 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1126 AM CST WED FEB 17 2016
THE MAIN CONCERN DURING THIS PERIOD IS WHETHER MVFR/IFR CEILINGS
WILL DEVELOP OVERNIGHT INTO THURSDAY MORNING. AS THE AREA OF HIGH
PRESSURE CURRENTLY OVER THE AREA MOVES OFF TO THE EAST...THE FLOW
WILL BECOME SOUTH AHEAD A DEVELOPING AREA OF LOW PRESSURE IN THE
LEE OF THE CANADIAN ROCKIES. A RIBBON OF MOISTURE/CLOUDS CURRENTLY
EXTENDS FROM NORTH DAKOTA SOUTHEAST ACROSS IOWA INTO ILLINOIS.
CEILINGS IN THIS MOISTURE FIELD ARE MVFR ACROSS THE DAKOTAS BUT
BECOME VFR FOR THE MOST PART ACROSS IOWA INTO ILLINOIS. THE 17.15Z
RAP AND HRRR AND THE 17.12Z NAM AND HI-RES NMM ALL INDICATE THESE
MVFR CEILINGS EXTEND ALL THE WAY ACROSS IOWA AND THEN WILL LIFT
NORTH INTO THE AREA OVERNIGHT AS THE FLOW TURNS TO THE SOUTH.
HOWEVER...THE 17.12Z HI-RES ARW AND 17.09Z SREF SEEM TO HAVE A
BETTER HANDLE ON CURRENT CLOUD TRENDS AND SUGGEST THE MVFR CLOUD
DECK MAY LIFT MORE INTO MINNESOTA AND GO BY TO THE NORTH OR IF THE
LOWER CEILINGS DO COME...IT MAY BE LATER THAN CURRENT EXPECTED.
FOR NOW...WILL NOT TOTALLY BACK OUT OF THE IDEA OF LOWER CLOUDS
COMING INTO THE TAF SITES...BUT WILL DELAY THE ARRIVAL BACK CLOSER
TO 12Z AND KEEP BOTH SITES IN THE MVFR CATEGORY.
&&
.HYDROLOGY...(FRIDAY AND INTO THE WEEKEND)
ISSUED AT 334 AM CST WED FEB 17 2016
SIGNIFICANT THAW WILL TAKE PLACE FRIDAY INTO THE WEEKEND...RELEASING
SNOWMELT INTO AREA STREAMS AND RIVERS. THIS MAY CAUSE SOME BREAKUP
OF ICE ON STREAMS/RIVERS WITH THE POSSIBILITY OF A FEW ICE JAMS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM...DAS
AVIATION...04
HYDROLOGY...DAS