Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/15/16


AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
1022 PM PST FRI FEB 12 2016 .SYNOPSIS... A WEAK UPPER LEVEL TROUGH PASSING TO THE NORTH WILL PROVIDE A BRIEF BREAK FROM THE RECORD HEAT THIS WEEKEND. A BUILDING RIDGE ALOFT AND GUSTY OFFSHORE WINDS BRING A RETURN OF RECORD HEAT EARLY NEXT WEEK. A SECOND UPPER LEVEL LOW WILL SUPPORT MUCH COOLER CONDITIONS WITH THE CHANCE OF RAIN LATE WEDNESDAY INTO THURSDAY. && .SHORT TERM...(FRI-MON) UPPER LEVEL TROUGH MOVING INTO NORTHERN CALIFORNIA TONIGHT WITH RIDGE AXIS SLIDING WELL EAST OF OUR AREA. THIS HAS RESULTED IN SLIGHT ONSHORE TRENDS THIS EVENING...WITH CURRENT LAX-DAGGETT GRADIENT AT -1.9 MB. SATELLITE IMAGERY SHOWING AREAS OF LOW CLOUDS AND DENSE FOG ACROSS PORTIONS OF THE COASTAL WATERS (WHICH WAS HIGHLIGHTED WITH A MARINE WEATHER STATEMENT)...LOCALLY EXTENDING INTO THE CENTRAL COAST THIS EVENING. MOST OF THE FOG OFFSHORE OF LOS ANGELES COUNTY IS FORMING NEAR CATALINA ISLAND AND THE SAN PEDRO CHANNEL. BUT CONDITIONS ARE COMING TOGETHER FOR SOME PATCHY DENSE FOG JUST ABOUT ANYWHERE ALONG THE IMMEDIATE COAST TONIGHT...AND HAVE INCLUDED THAT IN ZONE UPDATE. COMBINATION OF SHALLOW/STRONG MARINE INVERSION...WEAKENING PRESSURE GRADIENTS...AND COASTAL DEWPOINTS RISING INTO THE MID 50S IS REASONING FOR POTENTIAL DENSE FOG ALONG IMMEDIATE COAST. AS THE TROUGH MOVES INLAND ON SATURDAY...THERE IS SOME INCREASING NORTHERLY FLOW SETTING UP ACROSS THE FORECAST AREA...ESPECIALLY TOMORROW NIGHT. INLAND AREAS NOT SHOWING A WHOLE LOT OF COOLING ON SATURDAY AT 950 MB LEVEL...SO BUMPED UP MOST VALLEY TEMPERATURES A FEW DEGREES IN EVENING UPDATE. TAKING A GLANCE AT THE 00Z NAM MODEL...SEEING ANOTHER RESURGENCE OF OFFSHORE FLOW FROM SUNDAY THROUGH TUESDAY WITH UPPER LEVEL RIDGE REBUILDING OVER THE AREA. STILL LOOKING LIKE STRONGEST OFFSHORE WIND PUSH WILL BE SUNDAY NIGHT INTO MONDAY WITH WIDESPREAD ADVISORIES LIKELY ACROSS VENTURA AND LOS ANGELES COUNTIES. WITH PROJECTED LAX-DAGGETT GRADIENT APPROACHING -7 MB ON SUNDAY MORNING AND SOME UPPER LEVEL WIND/THERMAL SUPPORT...COULD SEE SOME ISOLATED WIND GUSTS UP TO 60 MPH IN THE FAVORED MOUNTAIN AREAS. THE OFFSHORE WINDS WITH LOW HUMIDITIES AND WARM TEMPERATURES WILL BRING ANOTHER ROUND OF ELEVATED FIRE DANGER SUNDAY THROUGH TUESDAY. THE OTHER BIG STORY WILL CONTINUE TO BE THE UNUSUALLY HOT TEMPERATURES EXPECTED SUNDAY THROUGH TUESDAY...WITH MANY COASTAL/VALLEY AREAS EXPECTED TO CLIMB WELL INTO THE 80S AND LOWER 90S. ON SUNDAY...COULD SEE A COUPLE OF RECORDS BROKEN THEN EVEN BETTER CHANCE OF RECORDS BEING SET ON MONDAY AND TUESDAY. .LONG TERM...(TUE-FRI) FOR THE EXTENDED...12Z MODELS START OUT IN DECENT SYNOPTIC AGREEMENT...BUT DIVERGE LATER IN THE PERIOD. AT UPPER LEVELS RIDGE WILL LINGER ON TUESDAY THEN A TROUGH WILL APPROACH AND MOVES ACROSS THE WEST COAST WEDNESDAY THROUGH FRIDAY. NEAR THE SURFACE WEAK OFFSHORE FLOW WILL PREVAIL ON TUESDAY THEN SHIFT TO ONSHORE WEDNESDAY THROUGH FRIDAY. FORECAST-WISE...TUESDAY WILL BE AN UNREMARKABLE DAY WITH CLEAR SKIES...LIGHT OFFSHORE BREEZES AND HIGH TEMPERATURES WELL ABOVE NORMAL. FOR WEDNESDAY AND THURSDAY...THE MODELS DIVERGE NOTICEABLY LEADING TO A LOW CONFIDENCE FORECAST. THE ECMWF MOVES A TROUGH ACROSS THE AREA WEDNESDAY/THURSDAY AND GENERATES A DECENT RAIN EVENT FOR THE AREA. CONVERSELY...THE GFS IS MUCH LESS BULLISH WITH THIS TROUGH...HARDLY SPITTING OUT ANY PRECIPITATION. WITH SUCH MODELS DIFFERENCES...WILL NOT DEVIATE FROM PREVIOUS FORECAST THINKING WHICH INCLUDED CHANCE/SLIGHT CHANCE POPS FOR THE AREA WEDNESDAY AND THURSDAY. HOPEFULLY...MODELS WILL COME INTO SOME BETTER AGREEMENT OVER THE NEXT COUPLE OF DAYS. BY THURSDAY NIGHT AND FRIDAY...BOTH MODELS PUSH TROUGH EAST OF THE AREA AND INDICATE DRY CONDITIONS. && .AVIATION...13/0600Z. AT 0530Z...AT KLAX...THERE WAS A SURFACE BASED INVERSION LAYER TO 1700 FEET WITH A TEMP OF 24 DEG C. FOR COASTAL TAF SITES INCLUDING KSMX & KPRB...LOW CONFIDENCE IN THE 06Z TAFS THROUGH 16Z DUE THE POSSIBILITY OF FOG/LOW CLOUDS. EXPECT IFR TO LIFR WITH LOCALIZED VLIFR IN AREAS WHERE FOG/LOW CLOUDS DO DEVELOP. MODERATE TO HIGH CONFIDENCE FOR THE REMAINDER OF THE TAF PERIOD. INLAND TAF SITES...HIGH CONFIDENCE IN 06Z CAVU TAFS. KLAX...LOW CONFIDENCE IN 06Z TAF THROUGH 16Z DUE TO THE POSSIBILITY OF LOW FOG AND LOW CLOUDS. THERE IS A 40 PERCENT CHANCE OF LIFR TO VLIFR CIGS/VSBYS DUE TO FOG/LOW CLOUDS THROUGH 16Z. MODERATE CONFIDENCE IN THE REMAINDER OF THE TAF PERIOD. KBUR...HIGH CONFIDENCE IN 06Z CAVU TAF. && .MARINE...12/800 PM... A MARINE WEATHER STATEMENT WAS ISSUED THIS EVENING FOR THE POSSIBILITY OF DENSE FOG FOR ALL AREAS THROUGH SATURDAY MORNING. PLEASE SEE MWSLOX FOR DETAILS. FOR THE OUTER WATERS...THERE IS HIGH CONFIDENCE IN SMALL CRAFT ADVISORY (SCA) CONDITIONS THROUGH LATE SUNDAY NIGHT DUE TO EITHER SCA WINDS OR A 10-13 FT...LONG PERIOD W-NW SWELL. THE STRONGEST N-NW WINDS ACROSS THE OUTER WATERS ARE EXPECTED SATURDAY AFTERNOON AND NIGHT...WHEN THERE COULD BE SOME LOCAL GALE FORCE WINDS. SCA WINDS COULD LINGER INTO MONDAY...BUT SHOULD WEAKEN CONSIDERABLY BY TUESDAY. FOR THE INNER WATERS N OF PT CONCEPTION...THERE IS HIGH CONFIDENCE IN SCA CONDITIONS FOR HAZARDOUS SEAS THROUGH SUNDAY EVENING. THIS IS DUE TO THE 10-13 FT...LONG PERIOD W-NW SWELL. WINDS WILL GENERALLY REMAIN BELOW SCA CRITERIA...THROUGH THE FORECAST PERIOD...BUT THERE COULD BE SOME LOCAL N-NE GUSTS TO 25 KT SATURDAY EVENING THROUGH MONDAY EVENING. FOR THE INNER WATERS S OF PT CONCEPTION...THERE IS GOOD CONFIDENCE THAT WINDS AND SEAS WILL REMAIN BELOW SCA CRITERIA THROUGH SUNDAY AFTERNOON. HOWEVER...SOME 10 FT SEAS ARE POSSIBLE IN WESTERN PORTIONS OF THE SANTA BARBARA CHANNEL THROUGH SATURDAY AFTERNOON...DUE TO THE LONG PERIOD SWELL. THERE IS ALSO A CHANCE FOR SOME ISOLATED NE WIND GUSTS TO 25 KT ON SUNDAY MORNING BETWEEN SANTA MONICA AND VENTURA. STRONGER NE WINDS ARE EXPECTED LATE SUNDAY NIGHT INTO MONDAY...WHEN A SCA MAY BE NEEDED. && .LOX WATCHES/WARNINGS/ADVISORIES... CA...HIGH SURF ADVISORY IN EFFECT UNTIL 9 AM PST SUNDAY FOR ZONES 34-35. (SEE LAXCFWLOX). BEACH HAZARDS STATEMENT IN EFFECT THROUGH SUNDAY MORNING FOR ZONE 39. (SEE LAXCFWLOX). HIGH SURF ADVISORY IN EFFECT UNTIL NOON PST SUNDAY FOR ZONES 40-41-87. (SEE LAXCFWLOX). PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IN EFFECT UNTIL 9 PM PST SUNDAY FOR ZONE 645. (SEE LAXMWWLOX). SMALL CRAFT ADVISORY IN EFFECT UNTIL 3 AM PST MONDAY FOR ZONES 670-673-676. (SEE LAXMWWLOX). && $$ PUBLIC...GOMBERG AVIATION...MUNROE/DB MARINE...SUKUP SYNOPSIS...MUNROE WEATHER.GOV/LOSANGELES
Area Forecast Discussion National Weather Service Sacramento CA 1015 PM PST FRI FEB 12 2016 .SYNOPSIS... Dry and mild weather through early next week with well above normal temperatures. Wetter and cooler weather pattern expected middle to latter portion of next week. && .DISCUSSION... Upper trof moving through Norcal with weakening surface front. CI/CS streaming into Interior NorCal is now sagging SEwd with upper trof. Moisture profiles from BUFKIT show high cloudiness eroding/ dissipating around 12z at the TAF sites in the Srn Sac/Nrn SJV with winds turning NW. This should limit/preclude widespread fog production. Subjective analysis is the HRRR is likely hitting the ) VSBYS too hard in the Vly Sat morning...and believe the fog will not be as dense or cover as much area as forecast. The patchy fog wording currently in the zones should suffice. JHM Heights and thicknesses progged to increase over the weekend as upper ridge amplifies off the West Coast. High temperatures forecast mainly in the lower 70s Saturday for the Central Valley, which is upwards of 10 to 12 degrees above normal and at record values for KSAC/KSCK. Some short lived patchy morning valley fog will continue to be possible over the weekend from Sacramento southward. Another weak weather system rides over the ridge Sunday with some light overrunning precip possible into far northern portions of CA. However associated precip continues to be modeled north of our forecast area. Surface high pressure building through Oregon into the Great Basin will result in some locally breezy northerly wind from Sunday afternoon into Monday. High temps expected to slowly trend up over the weekend into Monday. Max Ts in the Central Valley expected in the mid to upper 70s Sun/Mon with readings continuing right around record values for the Sacramento and Stockton areas. PCH .EXTENDED DISCUSSION (Tuesday THROUGH Friday) Conditions will remain dry through Tuesday. On Wednesday, NorCal transitions into a wet pattern as a trough impacts the west coast. Both the GFS & ECMWF models agree that this storm will start impacting our region by Wednesday evening. However, the challenge with this system is that the models disagree on the details. The GFS shows a quickly moving trough that weakens by Thursday morning and puts our region back into a dry, ridging pattern by Thursday afternoon/evening. The ECMWF indicates a stronger, wetter trough that keeps a threat of precipitation in our CWA through Thursday evening. Have medium confidence that interior NorCal will get light to moderate rain/snow Wednesday evening into Thursday afternoon with snow levels around 5000 ft. The models continue to diverge on Friday with the GFS maintaining a dry ridge while the ECMWF brings in another wave of precipitation that impacts area north of Interstate 80. Confidence is lower, but have kept lingering chances of precipitation through Friday until models come into better agreement. JBB && .AVIATION... SWly flow alf vrg to NWly Sat. Vrbl clds AOA FL120 for Intr NorCal nxt 24 hrs with VFR conds exc isold MVFR/IFR/LIFR poss in Srn Sac/Nrn San Joaquin vlys in BR/FG btwn 10z-18z Sat. && .STO Watches/Warnings/Advisories... None. && $$
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
652 PM MST SUN FEB 14 2016 .UPDATE... ISSUED AT 652 PM MST SUN FEB 14 2016 UPSTREAM IN SOUTHWESTERN WYOMING SNOWED HAS STOPPED FOR NOW AS THE BULK OF ENERGY HAS MOVED DOWNSTREAM ALONG THE CONTINENTAL DIVIDE AREAS OF CENTRAL COLORADO. ALLOWED WINTER WEATHER ADVISORIES TO CONTINUE THROUGH TOMORROW DESPITE THE OBVIOUS BREAK IN SNOWFALL...WHICH HAS ALREADY BEGUN AROUND THE STEAMBOAT SPRINGS AREA AND WILL SOON BEGIN IN THE FLATTOPS. THE SHORT TERM MODELS ARE INDICATING THE BREAK TO LAST THROUGHOUT THE NEXT 6 TO 12 HOURS...BUT SNOW PICKING UP TOWARD DAYBREAK FROM THE NORTHWEST AGAIN. TOMORROW/S SNOW IS STILL LOOKING MORE OROGRAPHICALLY DRIVEN AS OPPOSED TO TODAY/S DISTURBANCE WHICH ALLOWED SNOWFALL ALONG THE LOWER ELEVATIONS OF NORTHWEST COLORADO ALONG THE FOOTHILLS OF THE MOUNTAINS. && .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 306 PM MST SUN FEB 14 2016 A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON. BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70 CORRIDOR...AND ROARING FORK VALLEY. UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS AND PULL DOWN EARLY IF NEEDED. THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 306 PM MST SUN FEB 14 2016 BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE THEIR WARM TREND FOR A NICE START TO THE WORK WEEK. STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM. AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS EASTWARD. EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 417 PM MST SUN FEB 14 2016 SNOW SHOWERS CONTINUE TO IMPACT AREAS OF WESTERN COLORADO FROM RABBIT EARS PASS SOUTH TO VAIL PASS. ANOTHER AREA OF SNOW WILL IMPACT KEGE AND KASE THROUGH ABOUT 04Z. CONDITIONS WILL IMPROVE BY 06Z AT MANY LOCATIONS...STRONG NW WINDS AT AND ABOVE MTN TOP LEVEL WILL CONTINUE THROUGH ABOUT 12Z. AFTER 12Z SNOW WILL BE LIMITED TO THE MTNS ALONG AND NORTH OF VAIL PASS INTO WYOMING. BREEZY CONDITIONS WITH GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE DAY MONDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR COZ004-005-013. WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010. UT...NONE. && $$ UPDATE...JAM SHORT TERM...JOE/TGR LONG TERM...TGR AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
430 PM MST SUN FEB 14 2016 .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 306 PM MST SUN FEB 14 2016 A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON. BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70 CORRIDOR...AND ROARING FORK VALLEY. UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS AND PULL DOWN EARLY IF NEEDED. THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 306 PM MST SUN FEB 14 2016 BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE THEIR WARM TREND FOR A NICE START TO THE WORK WEEK. STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM. AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS EASTWARD. EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 417 PM MST SUN FEB 14 2016 SNOW SHOWERS CONTINUE TO IMPACT AREAS OF WESTERN COLORADO FROM RABBIT EARS PASS SOUTH TO VAIL PASS. ANOTHER AREA OF SNOW WILL IMPACT KEGE AND KASE THROUGH ABOUT 04Z. CONDITIONS WILL IMPROVE BY 06Z AT MANY LOCATIONS...STRONG NW WINDS AT AND ABOVE MTN TOP LEVEL WILL CONTINUE THROUGH ABOUT 12Z. AFTER 12Z SNOW WILL BE LIMITED TO THE MTNS ALONG AND NORTH OF VAIL PASS INTO WYOMING. BREEZY CONDITIONS WITH GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE DAY MONDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR COZ004-005-013. WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010. UT...NONE. && $$ SHORT TERM...JOE/TGR LONG TERM...TGR AVIATION...TGJT
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 AM EST SAT FEB 13 2016 .SYNOPSIS... AN ARCTIC COLD FRONT WILL SWEEP ACROSS THE REGION OVERNIGHT WITH ISOLATED TO SCATTERED SNOW SHOWERS AHEAD OF IT. BEHIND THE ARCTIC COLD FRONT...THE COLDEST AIRMASS OF THE SEASON WILL BUILD ACROSS THE REGION FOR THE WEEKEND WITH BITTERLY COLD TEMPERATURES AND WIND CHILLS. A STORM SYSTEM MAY IMPACT THE REGION MONDAY INTO THE MID WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1235 AM EST...AN ARCTIC COLD FRONT WAS POSITIONED JUST NORTH AND WEST OF THE FORECAST AREA AND POISED TO MOVE SOUTHWARD THROUGH THE OVERNIGHT HOURS. THE FRONT WILL BE MOVING THROUGH THE REGION BETWEEN 1 AM AND 6 AM FROM NW TO SE. AHEAD OF THIS FRONTAL BOUNDARY THERE WILL BE ISOLATED TO SCATTERED SNOW SHOWERS...ALTHOUGH THE INTENSITY AND COVERAGE OF SNOW SHOWERS HAS DECREASED OVER THE PAST FEW HOURS REMOVED FROM THE MOISTURE SOURCE /LAKE ONTARIO/. THE LATEST 3-KM HRRR SHOWS SNOW SHOWERS WEAKENING AS THEY TRACK SOUTHEASTWARD THROUGH THE AREA ASSOCIATED WITH THE BOUNDARY. SNOWFALL AMOUNTS ARE EXPECTED TO BE ON THE LIGHT SIDE WITH GENERALLY A DUSTING TO 2 INCHES. THE HIGHER TOTALS WILL BE OVER THE WRN DACKS. IT WILL BE ANOTHER VERY COLD NIGHT...BUT NOT AS COLD AS TEMPERATURES WILL BE LATER IN THE WEEKEND. LOWS OVERNIGHT WILL RANGE FROM 10 BELOW ZERO NORTHWEST AREAS TO 15 ABOVE ZERO SOUTHEAST TOWARDS NW CT AND THE MID HUDSON RIVER VALLEY. WINDS WILL ALSO INCREASE OVERNIGHT ACROSS THE FCST AREA WITH A WIND CHILL WARNING STARTING AT 3 AM FOR THE SOUTHERN ADIRONDACKS...WESTERN MOHAWK VALLEY...EASTERN CATSKILLS AND SOUTHERN VERMONT. THE JAIL BREAK OF ARCTIC AIR KICKS IN...AS THE WINDS BEHIND THE FRONT WILL BE MAINLY WEST TO SOUTHWEST AT 10 TO 20 MPH WITH GUSTS TO 30-40 MPH. && .SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/... WIND CHILL WARNINGS IN EFFECT FOR SATURDAY-SUNDAY MORNING FOR ALL OF EASTERN NEW YORK AND ADJACENT WESTERN NEW ENGLAND. THE COLDEST AIRMASS OF THE SEASON WILL BE WITH US OVER THE WEEKEND IN THE WAKE OF THE ARCTIC FRONT AS AN ARCTIC AREA OF HIGH PRESSURE SETTLES OVER THE REGION BY SUNDAY. H8 TEMPS DROP TO 27 TO 34 DEGREES BELOW ZERO BY SATURDAY EVENING. HAVE GONE WITH A NON- DIURNAL RANGE OF TEMPS ON SATURDAY AS THE LOWS FRIDAY NIGHT AND THE HIGHS ON SATURDAY SHOULD BE THE SAME WITH THE TEMPS DROPPING ALL DAY ON SATURDAY. TEMPS ARE EXPECTED TO DROP FROM 10 BELOW TO 15 ABOVE ZERO EARLY SATURDAY MORNING TO 15 BELOW ZERO TO 5 ABOVE ZERO BY EARLY SATURDAY EVENING. WIND CHILLS ON SATURDAY WILL RANGE FROM 10 BELOW TO 35 BELOW ZERO WITH NORTHWEST WINDS 10 TO 20 MPH WITH GUSTS 30 TO 40 MPH. SATURDAY NIGHT WILL BE ESPECIALLY BRUTAL AS AIR TEMPERATURES ARE EXPECTED TO DROP TO 5 BELOW TO NEAR 30 BELOW ZERO WITH WIND CHILL VALUES 25 BELOW TO NEAR 50 BELOW ZERO. SUNDAY INTO SUNDAY NIGHT...HIGH PRESSURE WILL MOVE OVER OUR REGION ON SUNDAY AND OFF THE EASTERN SEABOARD LATE SUNDAY NIGHT. WINDS WILL STILL BE FAIRLY STRONG ON SUNDAY MORNING BEFORE SUBSIDING LATER SUNDAY INTO SUNDAY NIGHT. HIGHS ON SUNDAY WILL BE IN THE ZERO TO 15 ABOVE ZERO RANGE WITH THE LOWS SUNDAY NIGHT BETWEEN 10 BELOW AND 5 ABOVE ZERO. MONDAY WILL FEATURE INCREASING CLOUDS AS THE NEXT SYSTEM STARTS TO TRACK NORTHEASTWARD FROM THE SOUTHEAST COAST. HIGHS WILL MODERATE ON MONDAY RANGING FROM THE UPPER TEENS NORTHWEST TO UPPER 20S SOUTHEAST WITH A CHANCE OF SNOW ACROSS THE SOUTHERN HALF OF THE FA LATE IN THE DAY. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... A SIGNIFICANT STORM IS EXPECTED TO IMPACT THE REGION DURING THE EARLY PART OF THE EXTENDED PERIOD. THERE IS INCREASING CONFIDENCE AS TO THE TRACK AND INTENSITY OF THIS SYSTEM... AT LEAST IN ITS EARLY STAGES. TWO TO SIX INCH ACCUMULATIONS ARE EXPECTED MONDAY NIGHT... WHICH IS MORE OR LESS THE START OF THE EVENT. BEYOND THAT THERE IS STILL UNCERTAINTY AS TO PRECIPITATION TYPE AS THERE IS PLENTY OF MILD AIR TO BE DRAWN IN OUT AHEAD OF THIS SYSTEM...THUS THE EXACT TRACK AND INTENSITY WILL BE CRUCIAL. RIGHT NOW...THE TRACK IS EXPECTED TO BE FROM ABOUT CHARLOTTE NORTH CAROLINA THROUGH ALBANY. BECAUSE THE TRACK IS NOT SEEN AS GOING FAR ENOUGH TO THE EAST TO GIVE US AN ALL SNOW EVENT...INDICATIONS ARE PRECIPITATION WILL LIKELY CHANGE OVER TO RAIN FOR A TIME ON TUESDAY...PARTICULARLY OUTSIDE OF THE ADIRONDACKS...BEFORE EVERYTHING TAPERS OFF AS SNOW TUESDAY NIGHT. THERE IS THE POTENTIAL FOR VERY SIGNIFICANT ACCUMULATIONS...BUT ANY DECENT PERIOD OF RAIN...AS IS EXPECTED RIGHT NOW...WILL KEEP SNOW ACCUMULATIONS AT BAY. BROAD LAKE ENHANCEMENT ON INCREASING WESTERLY WINDS BEHIND THE DEPARTING STORM WILL KEEP SNOW SHOWERS OF LIGHT AMOUNTS GOING FOR MANY AREAS TUESDAY NIGHT...WITH MIXED RAIN AND SNOW SHOWERS FOR WEDNESDAY. BUT THE ACTIVITY WILL WIND DOWN RAPIDLY ON THURSDAY AS HIGH PRESSURE SETTLES IN...BUT WITHOUT THE EXTREME COLD WE/RE EXPECTING THIS WEEKEND. HIGH TEMPERATURES ARE EXPECTED TO RANGE FROM THE MID 30S THROUGH THE UPPER 40S ON TUESDAY...THE UPPER 20S TO AROUND 40 DEGREES ON WEDNESDAY...AND THE MID TEENS TO AROUND 30 DEGREES ON THURSDAY. FRIDAY HIGHS WILL REBOUND SOMEWHAT. OVERNIGHT LOWS MONDAY NIGHT WILL RANGE FROM THE UPPER TEENS IN THE MOUNTAINS TO THE UPPER 20S IN THE LOWER MID HUDSON VALLEY. TUESDAY NIGHT...THEY WILL RANGE FROM THE MID 20S IN THE WESTERN ADIRONDACKS...TO THE LOWER 30S DOWN THE HUDSON VALLEY. WEDNESDAY NIGHT WILL TURN SHARPLY COLDER...AND THURSDAY NIGHT WILL BE COLDEST...WITH LOWS RANGING FROM THE LOW SINGLE DIGITS IN THE WESTERN ADIRONDACKS...TO THE UPPER TEENS DOWN THE MID HUDSON VALLEY. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... A CLIPPER LOW WILL PASS NORTH OF THE REGION THROUGH THE EARLY MORNING HOURS...AS THE ASSOCIATED ARCTIC COLD FRONT TRACKS THROUGH. A NW FLOW OF ARCTIC AIR WILL IMPACT THE REGION THROUGH THE DAY INTO THE NIGHT PERIOD WITH GUSTY WINDS. THE ARCTIC FRONT WILL FOCUS SOME ISOLATED TO SCATTERED SNOW SHOWERS OR A SQUALL FROM THE CAPITAL REGION NORTH...IMPACTING KGFL/KALB/KPSF BETWEEN 04Z-09Z. THE SNOW SHOWERS WILL BE FAIRLY ISOLATED TO SCATTERED IN COVERAGE DUE TO VERY LIMITED LOW-LEVEL MOISTURE. A VCSH WAS USED AT KALB/KPSF/KGFL THROUGH ABOUT 10-11Z. VFR CONDITIONS WILL BE DOMINATE...ASIDE FOR SOME MVFR CIGS/VSBYS WITH ANY SNOW SHOWERS/ISOLD SQUALLS ESPECIALLY AT KPSF/KGFL. CIGS WILL BE MAINLY IN THE 4-9 KFT AGL RANGE. IN THE WAKE OF THE FRONT AFTER DAYBREAK...SOME LINGERING STRATOCUMULUS OR MID LEVEL CLOUDS WILL LINGER. OVERALL...VFR CONDITIONS WILL CONTINUE IN THE FRIGID NORTHWEST FLOW THROUGH THE PM. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO THE FRONTAL PASSAGE BEFORE DAYBREAK...THEN VEER TO THE W TO NW AT 6- 12 KTS WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE IN THE MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. WINDS WILL SLOWLY DIMINISH DURING THE EVENING BUT WILL STILL BE GUSTY. THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 4-10 KTS PRIOR TO MIDNIGHT...THEN VEER TO THE W TO NW AT 6-12 KTS BEFORE DAYBREAK WITH SOME GUSTS TO 20-25 KTS. THE WINDS WILL INCREASE IN THE WAKE OF THE ARCTIC FRONT LATE TOMORROW MORNING INTO THE AFTERNOON AT 12-20 KTS WITH SOME GUSTS AROUND 30 KTS...ESPECIALLY AT KALB/KPSF. OUTLOOK... SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX. SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SN. SUNDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN. WASHINGTONS BIRTHDAY: HIGH OPERATIONAL IMPACT. DEFINITE RA...SN. MONDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY RA...SN. TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN. TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN. WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX. && .HYDROLOGY... WITH BITTER COLD AIR IN PLACE...ICE COVERAGE ON RIVERS AND LAKES WILL CONTINUE TO INCREASE AND STRENGTHEN OVER THE NEXT FEW DAYS. A FEW LIGHT SNOW SHOWERS ARE POSSIBLE...MAINLY THIS EVENING...BUT THIS WILL AMOUNT TO LITTLE IF ANY HYDROLOGIC SIGNIFICANCE. HOWEVER...THERE IS THE POTENTIAL FOR A HEAVY PRECIPITATION EVENT TO IMPACT THE REGION FROM MONDAY NIGHT THROUGH WEDNESDAY. THERE REMAINS CONSIDERABLE UNCERTAINTY REGARDING THE TYPES OF PRECIPITATION THAT MAY OCCUR...WHICH WILL ULTIMATELY DEPEND ON THE EXACT TRACK OF THIS POTENTIAL STORM SYSTEM. AT THIS TIME...MODEL GUIDANCE IS SUGGESTING ONE TO THREE INCHES OF LIQUID EQUIVALENT COULD OCCUR...AND MUCH OF THIS COULD BE IN THE FORM OF RAIN. IF THIS RAIN WERE TO MATERIALIZE...IT COULD HAVE A HIGH IMPACT ON RIVERS AND STREAMS...ESP CONSIDERING THE GROUND WILL BE FULLY FROZEN BY THAT TIME...ALLOWING MUCH OF THE PRECIP TO BE RUNOFF. DETAILS WILL BECOME MORE CERTAIN OVER THE NEXT FEW DAYS. FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR CTZ001-013. NY...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR NYZ032-033-038- 042-047-051-058-063-082. WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR NYZ039>041-043-048>050-052>054-059>061-064>066-083- 084. MA...WIND CHILL WARNING FROM 1 PM THIS AFTERNOON TO 1 PM EST SUNDAY FOR MAZ001-025. VT...WIND CHILL WARNING UNTIL 1 PM EST SUNDAY FOR VTZ013>015. && $$ SYNOPSIS...IRL/WASULA NEAR TERM...11/JPV/WASULA SHORT TERM...11 LONG TERM...ELH AVIATION...NAS HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
635 AM EST SAT FEB 13 2016 ...UPDATED AVIATION DISCUSSION... .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY. THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT. && .SHORT TERM (TODAY THROUGH SUNDAY)... AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY FOR THE MAJORITY OF THE DAY. THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4 CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH. LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY DROP INTO THE 20S. HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON. && .LONG TERM (MONDAY THROUGH NEXT FRIDAY)... AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID- ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA. FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND TUE AHEAD OF THE FRONT. && .AVIATION (THROUGH 12Z SUNDAY)... A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH THE REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT. THIS FRONT IS CURRENTLY CROSSING THE I-4 CORRIDOR THROUGH KTPA/KPIE/KLAL...AND WILL CONTINUE SOUTH OF KFMY/KRSW BY MIDDAY. MVFR CIGS AND PATCHY DENSE FOG THROUGH THE I-4 TERMINALS WILL IMPROVE SHORTLY AFTER SUNRISE WITH THE FRONTAL PASSAGE. WINDS SHIFT NORTHERLY BEHIND THE FRONT...AND THEN NORTHEASTERLY TONIGHT. PREVAILING VFR CONDITIONS ARE FORECAST THROUGH 12Z SUNDAY FOR ALL TERMINALS AFTER THE PASSAGE OF THE FRONT THIS MORNING. && .MARINE... A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF WEDNESDAY. && .FIRE WEATHER... A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED THROUGH THE EARLY PORTION OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 65 43 68 54 / 0 0 0 0 FMY 73 47 72 55 / 0 0 0 0 GIF 69 43 66 53 / 0 0 10 10 SRQ 67 44 68 54 / 0 0 0 0 BKV 65 38 67 49 / 0 0 0 0 SPG 65 48 67 56 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
349 AM EST SAT FEB 13 2016 .DISCUSSION... ...POOR TO HAZARDOUS BOATING CONDITIONS THIS WEEKEND... TODAY-TONIGHT... LATEST ANALYSIS SHOWS A DRY COLD FRONT PUSHING INTO THE PANHANDLE... A LITTLE SLOWER THAN ANTICIPATED. THE 00Z KJAX/KTAE RAOBS INDICATE PWATS ONLY ARND 0.75"...WHILE LATEST SAT PICS SHOW A FEW CLOUD BANDS DVLPG AHEAD OF THE FRONT IN TANDEM WITH A BAND OF H100-H85 DEWPOINT DEPRESSIONS BTWN 3-5C OVER THE NRN PENINSULA. AHEAD OF THE FRONT... HOWEVER...A DRY/STABLE AIRMASS REMAINS IN PLACE. THE 00Z RAOBS AT KXMR/KTBW/KMFL MEASURED PWAT VALUES ARND 0.50"...WHILE RAP ANALYSIS INDICATES H100-H85 DEWPOINT DEPRESSIONS BTWN 5-7C ALONG THE I-4 CORRIDOR...ARND 15C OVER LAKE OKEECHOBEE AND THE TREASURE COAST. AS EXPECTED...THE APPROACHING FRONTAL TROF HAS ERODED THE H100-H70 RIDGE/ANTICYCLONE AXIS THAT WAS IN PLACE OVER THE FL PENINSULA ON FRI. THE RIDGE HAS EFFECTIVELY SPLIT IN TWO WITH THE WRN HALF RETROGRADING INTO THE WRN GOMEX...THE ERN HALF PUSHING WELL E OF THE BAHAMA BANK TO MERGE WITH THE ATLC SUBTROPICAL RIDGE. THIS WILL LEAVE THE FRONT WITH LITTLE IMPEDANCE TO SLOW ITS FORWARD MOTION... ESPECIALLY GIVEN THE RAP40 INDICATES AVG H100-H70 FLOW BEHIND IT IS NW AT 25-30KTS. ANOTHER QUIET WX DAY IN STORE AS FRONTAL MOISTURE IS SIMPLY TOO LOW TO SUPPORT THE FORMATION OF ANYTHING MORE THAN A LOW LVL CLOUD DECK...MEAN RH VALUES THRU THE H100-H85 LYR ARE AOB 80PCT. FURTHERMORE...RAOBS SHOW A LINGERING SUBSIDENCE INVERSION IN THE H90-H80 LYR THAT WILL PANCAKE ANY CLOUD DECK BLO 5KFT. TEMPS WILL BE A BIT ON THE COOL SIDE FROM BREVARD/OSCEOLA CO NWD ONCE THE FRONT PUSHES THRU AS NWRLY FLOW DVLPS...KEEPING AFTN READINGS IN THE L/M60S DESPITE NEAR FULL SUN. TREASURE COAST/LAKE OKEECHOBEE AREAS WELL HAVE TIME TO WARM INTO THE L70S BEFORE THE FROPA...BUT EVEN THESE WILL BE 3-5F BLO AVG. TIGHTENING PGRAD BEHIND THE FRONT WILL ALLOW NRLY WINDS TO PERSIST OVERNIGHT...RESULTING IN A COOL AIR ADVECTION PATTERN THAT WILL ALLOW MIN TEMPS TO FALL INTO THE L/M40S W OF I-95. MARINE INFLUENCE WILL KEEP COASTAL TEMPS A FEW DEGS WARMER...GENERALLY U40S/L50S. SUNDAY... A HIGH PRESSURE RIDGE ALONG THE EASTERN SEABOARD WILL SHIFT OFFSHORE. AN EARLY MORNING COASTAL TROUGH WILL EXIST THEN DISSIPATE...GIVING WAY TO AN EASTERLY WIND FLOW IN THE AFTERNOON. THE AIR MASS WILL INITIALLY BE VERY DRY SO COASTAL RAIN CHANCES LOOK TO BE 10-15 PERCENT. WILL LEAVE SMALL POPS ALONG THE IMMEDIATE COAST THROUGH SUNDAY NIGHT. FORECAST SOUNDINGS ARE STILL SUPPORTIVE OF STRATOCUMULUS SPREADING INLAND FROM THE ATLANTIC. SO DESPITE THE MORE MILD EAST WIND FLOW...THIS CLOUDINESS SHOULD KEEP DAYTIME HIGHS A LITTLE BELOW THOSE FROM TODAY...MAINLY MID 60S NORTH AND UPPER 60S SOUTH. ONSHORE LOW LEVEL WINDS WILL KEEP OVERNIGHT LOWS MORE MILD...LOWER 50S NORTH INTERIOR AND UPPER 50S SOUTH COAST. MON INTO EARLY TUE... THIS PERIOD IS THE MAIN ITEM OF INTEREST FOR THE UPCOMING WEEK. A SHORTWAVE TROUGH IS FORECAST TO MOVE ACROSS THE SOUTHERN STATES AND SPIN UP A SURFACE LOW. THE 00Z GFS SHOWS A WEAKER SYSTEM FARTHER NORTH THAN 24 HOURS AGO. HENCE THE LOCAL LOW LEVEL WIND FIELDS ARE FORECAST TO BE WEAKER. PRECIPITABLE WATER IS STILL SHOWN TO ONLY RECOVER TO ABOUT 1.3 INCHES WITH SURFACE DEW POINTS IN THE UPPER 50S TO LOWER 60S. MOS POPS HAVE BACKED OFF TO 30-40 PERCENT FOR MON NIGHT. THE ECMWF ALSO SHOWS A WEAKER SYSTEM BUT THE POP VALUES ARE A LOT HIGHER THAN THE GFS. DO NOT WANT TO MAKE SIGNIFICANT CHANGES TO THE FORECAST JUST YET AS THE SUBTROPICAL JET CORE WILL BE NEARBY AND TEMPS ALOFT WILL BE QUITE COLD...SO EXPECT THAT THERE COULD BE ENOUGH SUPPORT FOR CONVECTION OVER THE GULF OF MEXICO TO SPREAD WELL INLAND. HAVE TRIMMED POPS BACK TO 50 PERCENT FOR MON NIGHT BUT KEPT SLIGHT CHANCE FOR THUNDER. RECENT WEAKER MODEL SOLUTIONS FOR THIS SYSTEM SUGGEST SOME SHOWER CHANCES MAY LINGER INTO TUE. REST OF WEEK... COLD FRONT IS FORECAST TO PUSH EAST OF THE AREA TUE OR TUE NIGHT... BRINGING DRYING AND WEAK COLD AIR ADVECTION. A SURFACE HIGH PRESSURE RIDGE WILL THEN BUILD FROM THE MIDWEST TO OFF THE ATLANTIC SEABOARD BY SAT...WITH A RIDGE AXIS SETTLING INTO THE LOCAL AREA. TEMPS LOOK CLOSE TO NORMAL. LATE WEEK ONSHORE FLOW SHOULD PUSH A FEW SHOWERS TOWARDS THE COAST...BUT POPS ARE TOO LOW TO MENTION. OTHERWISE IT LOOKS DRY. && .AVIATION...THRU 14/12Z SFC WINDS: THRU 13/12Z...W/SW 4-8KTS. BTWN 13/12Z-13/15Z BCMG N/NW 8-12KTS. BTWN 13/15Z-13/23Z...N/NW 12-15KTS OCNL G18-22KTS. BTWN 13/23Z-14/02Z...BCMG N 4-7KTS. VSBY/WX/CIGS: VFR ALL SITES. && .MARINE... TODAY-TONIGHT...POOR BOATING CONDITIONS AS A DRY COLD FRONT PUSHES THRU THE LCL ATLC WATERS. A MODERATE TO FRESH WRLY BREEZE THRU DAYBREAK WILL VEER TO N/NW BY MIDDAY AS THE FRONT PUSHES THRU. ROUGH SEAS AS WINDS MAKE THE SHIFT FROM AN OFFSHORE COMPONENT TO A NRLY COMPONENT THAT WILL BLOW OPPOSITE TO THE GULF STREAM CURRENT. PREVAILING WAVE HEIGHTS INCREASING FROM 2-4FT TO 4-6FT NEARSHORE... AND FROM 4-6FT TO 5-7FT OFFSHORE. STEEP WAVES WITH DOMINANT PDS BTWN 5-7SEC. CURRENT ADVISORY/CAUTION ORIENTATION LOOKS FINE FOR NOW... BUT MAY NEED TO EXPAND THE ADVISORY TO INCLUDE NEARSHORE TREASURE COAST WATERS BY LATE AFTN DUE TO THE GULF STREAM`S CLOSER PROXIMITY TO THE COAST. SUN-MON...BREEZY NORTHEAST/EAST WINDS SUN WILL VEER TO SOUTHEAST ON MON. THIS WILL KEEP CONDITIONS POOR FOR SMALL CRAFT OPERATION. MON NIGHT-WED...BREEZY SOUTH FLOW IS INDICATED FOR MON NIGHT. THIS WILL TRANSPORT MOISTURE NORTHWARD AND BRING A CHANCE OF SHOWERS AND A SLIGHT CHANCE FOR STORMS. MODELS DIFFER A BIT ON THE TUE- WED WINDS BUT OVERALL THE TREND IS FOR A WEAKER FRONTAL PASSAGE. && .PRELIMINARY POINT TEMPS/POPS... DAB 60 45 63 54 / 0 0 20 20 MCO 68 44 67 54 / 0 0 10 10 MLB 67 50 65 58 / 0 0 20 20 VRB 69 51 68 58 / 0 0 20 20 LEE 65 41 66 52 / 0 0 10 10 SFB 65 43 66 53 / 0 0 10 10 ORL 67 44 66 53 / 0 0 10 10 FPR 69 52 68 58 / 0 0 20 20 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR SEBASTIAN INLET TO JUPITER INLET 20-60 NM. SMALL CRAFT ADVISORY UNTIL 4 AM EST SUNDAY FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ SHORT TERM...BRAGAW LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
316 AM EST SAT FEB 13 2016 .SYNOPSIS... 08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS BROAD BUT AMPLIFIED UPPER LEVEL TROUGHING IN PLACE OVER THE EASTERN THIRD OF THE NATION. TROUGH IS ANCHORED BY A BROAD AND COLD UPPER LOW OVER EASTERN CANADA. FURTHER UPSTREAM WE FIND RIDGING THROUGH THE INTER-MOUNTAIN WEST...AND SHORTWAVE ENERGY ARRIVING OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA. BACK TO HOME...OUR REGION RESIDES WITHIN DEEP LAYER NW FLOW ON THE BACKSIDE OF THE EASTERN LONGWAVE TROUGH. SHORTWAVE ENERGY EMBEDDED WITHIN THE FLOW HAS EXITED OFF THE GA/CAROLINA COAST EARLY THIS MORNING. THIS PUSH IS DRIVING A WEAK COLD FRONT AT THE SURFACE DOWN FROM THE NORTH INTO THE FLORIDA PENINSULA. THE COLD FRONT IS CURRENTLY DROPPING SOUTH OVER THE NATURE COAST ZONES...AND SHOULD REACH THE I-4 CORRIDOR TOWARD SUNRISE...AND THEN EXIT SOUTH OF FORT MYERS BY MIDDAY. THIS IS A DRY FRONTAL PASSAGE WITH VERY LITTLE ATMOSPHERIC MOISTURE ABOVE 850MB. NARROW BAND OF LOW 2-4KFT CLOUDS LEADS THE FRONT...BUT THAT IS JUST ABOUT IT. THE FRONT WILL BE MOST MARKED BY A WIND SHIFT TO THE NORTH. LIKELY TO SEE SOME PATCHY FOG DEVELOPMENT IN THE PRE-DAWN HOURS AS WE GET SOME LOW LEVEL MOISTURE POOLING AHEAD OF THE FRONTAL BOUNDARY. THIS FOG MAY RESULT IN SOME TRICKY SPOTS FOR THE MORNING COMMUTE...BUT IT WILL NOT LAST LONG ONCE THE SUN COMES UP DUE TO THE COMBINATION OF DIURNAL MIXING...DRY AIR ADVECTION BEHIND THE FRONT. && .SHORT TERM (TODAY THROUGH SUNDAY)... AS MENTIONED IN THE SYNOPSIS...WEAK COLD FRONT WILL CROSS THE REGION THIS MORNING...AND BE SOUTH OF OUR ZONES BY THE AFTERNOON HOURS. THE AIRMASS CHANGE BEHIND THIS FRONT IS A BIT COOLER...BUT THE BIGGER CHANGE WILL BE IN THE MOISTURE AS DEWPOINTS QUICKLY DROP FROM NORTH TO SOUTH DURING THE DAY. IN FACT...AFTERNOON HIGH TEMPS WILL BE GENERALLY SEASONABLE...RANGING FROM THE LOWER 60S FAR NORTH TO THE MID/UPPER 60S CENTRAL...AND INTO THE LOWER 70S SOUTH. AFTER THE EARLY BAND OF CLOUDS...SKIES WILL BE MOSTLY SUNNY FOR THE MAJORITY OF THE DAY. THE FORECAST FOR TONIGHT IS COLDER...MAINLY DUE TO THE DRY AIR THAT WILL BE IN PLACE. HIGH PRESSURE DOES BUILD IN FROM THE NORTH...BUT THE RIDGE CENTER STAYS UP OVER THE MID-ATLANTIC STATES AND NEVER REALLY ALLOWS THE GRADIENT TO SLACKEN SUFFICIENTLY FOR IDEAL RADIATIONAL COOLING OVER OUR ZONES. AT THE VERY LEAST...THE RADIATIVE PROCESS WILL BE SLOWED...AND DOUBT MOST PLACES (OTHER THAN EXTREMELY WELL SHELTERED LOCATIONS) WILL BE ABLE TO DECOUPLE OVERNIGHT. SO...WHILE THE WIND MAY HELP KEEP MORE LOCATIONS ABOVE FREEZING...IT WILL LOWER THE POTENTIAL WIND CHILL VALUES FOR EARLY SUNDAY MORNING. DEEPEST INTO THE AIRMASS AND BEST POTENTIAL FOR RADIATIVE PROCESSES WILL BE OUR FAR NORTHERN ZONES. ALLOW INTERIOR LEVY COUNTY TO TOUCH 32 BRIEFLY AT DAWN...BUT OTHERWISE KEEP TEMPS ABOVE FREEZING. RANGE LOW TEMPS FROM THESE LOWER 30S OVER LEVY COUNTY...TO THE UPPER 30S/LOWER 40S BY THE I-4 CORRIDOR...AND GENERALLY IN THE LOWER/MID 40S FURTHER SOUTH. LOCATIONS SUCH AS SOUTHERN PINELLAS COUNTY AND THE ISLANDS/CAPES OF CHARLOTTE HARBOR WILL BE A BIT WARMER WITH NORTHEAST FLOW OFF WATER. AGAIN THOUGH...WINDS WILL NOT BE STRONG...BUT WILL NOT BE CALM EITHER. WIND CHILL VALUES ARE CURRENTLY FORECAST TO DROP INTO THE 30S LATE TONIGHT AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF BROOKSVILLE...WIND CHILL VALUES MAY BRIEFLY DROP INTO THE 20S. HIGH PRESSURE SHIFTS OFF THE ATLANTIC SEABOARD DURING SUNDAY...SHIFTING OUR WINDS TO THE EAST. THIS FLOW WILL BRING A SLOW INCREASE IN LOW LEVEL MOISTURE BACK ACROSS THE PENINSULA FROM THE ATLANTIC. FOR OUR FORECAST...THIS MAINLY JUST MEANS A RETURN TO A SCT CUMULUS FIELD FOR THE AFTERNOON HOURS. MANY GUIDANCE MEMBERS ARE SHOWING SOME CONVERGENCE SHOWERS ALONG THE FLORIDA EAST COAST ON SUNDAY THAT WILL ATTEMPT TO MIGRATE INLAND. NOT COMPLETELY SOLD ON THIS POTENTIAL AS THE MOISTURE DEPTH IS REALLY LACKING. HOWEVER...WILL ADD MENTION OF A FEW ISOLATED SPRINKLES AFTER 18Z SUNDAY ACROSS FAR EASTERN POLK/HIGHLANDS COUNTIES. ANY SPRINKLES WILL HAVE LIMITED TO NO IMPACT ON ANY OUTDOOR ACTIVITIES. TEMPERATURES REGION-WIDE FOR SUNDAY SHOULD RECOVER FROM THE CHILLY MORNING TEMPS TO THE 60S FOR THE AFTERNOON. && .LONG TERM (MONDAY THROUGH NEXT FRIDAY)... AN UPPER TROUGH INITIALLY FROM MANITOBA TO THE WESTERN GULF OF MEXICO WILL SHARPEN AND SHIFT INTO THE EASTERN COASTAL STATES TUE...AS A SURFACE LOW FORMS ON THE GULF COAST AND TRACKS TO THE MID- ATLANTIC STATES. THE LOW TRAILS A COLD FRONT INTO THE EASTERN GULF MON NIGHT AND ACROSS FL TUE. AS THE UPPER TROUGH AND SURFACE LOW MOVE EAST A RIDGE OF HIGH PRESSURE ALONG THEE EASTERN SEABOARD SLIDES EAST. AS IT DOES THE LOW LEVEL FLOW VEERS FROM EASTERLY TO SOUTHERLY BY MON NIGHT...HELPING TO MOISTEN THE ATMOSPHERE ALTHOUGH MODELS ONLY INCREASE PWAT VALUES INTO THE 1 TO 1.5 INCH RANGE. BUT THIS WILL BE ENOUGH ALONG WITH THE UPPER TROUGH AND COLD FRONT FOR SHOWERS AND THUNDERSTORMS...STARTING MON AFTERNOON THEN ENDING TUE AS THE FRONT EXITS TO THE EAST. THE GREATEST ODDS OF SHOWERS AND STORMS WILL BE MON NIGHT AND EARLY TUE MORNING. CURRENTLY THE BEST DYNAMICS FOR SEVERE STORMS APPEAR TO STAY NORTH OF THE AREA. FOR WED THROUGH FRI - THE UPPER TROUGH SLOWLY SLIPS OFFSHORE AS AN UPPER RIDGE BUILDS NORTHWARD OVER THE WESTERN STATES THEN MOVES ACROSS THE EASTERN STATES AS IT FLATTENS SOME. SURFACE HIGH PRESSURE BUILDS IN OVER THE MID-MISSISSIPPI VALLEY THEN MIGRATES TO THE ATLANTIC COAST WATERS. A DRY AND STABLE AIRMASS WILL BE IN PLACE TEMPERATURES RUNNING CLOSE TO SEASONAL. WINDS REMAIN RATHER MODEST...ONLY BRIEFLY APPROACHING 20 KNOTS ON THE GULF MON AND TUE AHEAD OF THE FRONT. && .AVIATION... A NARROW BAND OF BKN MVFR CIGS WILL CONTINUE TO DROP SOUTH THROUGH THE REGION EARLY THIS MORNING IN ADVANCE OF A WEAK COLD FRONT. THIS FRONT WILL CROSS THE TAMPA BAY AREA AROUND SUNRISE...AND THEN PASS SOUTH OF KFMY/KRSW LATER IN THE MORNING. WINDS SHIFT NORTHERLY BEHIND THIS FRONT...AND THE NORTHEASTERLY TONIGHT. A BRIEF PERIOD OF MVFR CIGS IS POSSIBLE AHEAD OF THE FRONT...WITH PATCHY FOG ALSO DEVELOPING BEFORE DAWN. A PERIOD OF IFR/MVFR VIS IS ALSO POSSIBLE THROUGH 13Z...WITH KLAL/KPGD MOST LIKELY TO SEE THE VIS RESTRICTIONS. PREVAILING VFR CONDITIONS ARE THEN FORECAST THROUGH 12Z SUNDAY. && .MARINE... A WEAK COLD FRONT DROPS SOUTHWARD THROUGH THE FORECAST WATERS THIS MORNING. WINDS WILL SHIFT TO THE NORTH BEHIND THIS FRONT REACHING CAUTIONARY LEVELS AT TIMES...OUTSIDE OF THE BAYS AND HARBORS. HIGH PRESSURE MOVING NORTH OF THE REGION TONIGHT WILL SHIFT WINDS TO THE NORTHEAST...WITH THE POTENTIAL FOR A MORE WIDESPREAD PERIOD OF CAUTIONARY LEVEL WINDS. WINDS SHIFT EAST ON SUNDAY AND DIMINISH BELOW HEADLINE CRITERIA BY THE AFTERNOON HOURS. THE NEXT COLD FRONT CROSSES THE EASTERN GULF OF MEXICO MONDAY NIGHT AND EARLY TUESDAY. WINDS CURRENTLY ARE NOT EXPECTED TO REACH HEADLINE CRITERIA BEHIND THIS FRONT THROUGH THE DAYLIGHT HOURS OF WEDNESDAY. && .FIRE WEATHER... A MUCH DRIER AIRMASS WILL ARRIVE ON NORTHERLY WINDS TODAY IN THE WAKE OF A WEAK COLD FRONT. WITH THE DRY AIR...RELATIVE HUMIDITY VALUES ARE FORECAST TO DROP BELOW 35 PERCENT FOR SEVERAL HOURS THIS AFTERNOON AS FAR SOUTH AS SARASOTA/DE SOTO/HIGHLANDS COUNTIES. NORTH OF THE I-4 CORRIDOR...RELATIVE HUMIDITY IS EXPECTED TO DROP INTO THE 20S FOR A TIME. ALTHOUGH IT WILL BE DRY...RED FLAG CONDITIONS ARE NOT FORECAST AS ERC VALUES REMAIN AT OR BELOW 25...AND WINDS WILL STAY BELOW CRITICAL LEVELS. LOW LEVEL MOISTURE BEGINS TO INCREASE DURING SUNDAY ON LIGHT EASTERLY FLOW...AND THIS MOISTURE RETURN CONTINUES INTO MONDAY. AFTER THIS AFTERNOON...CRITICAL LEVELS OF RELATIVE HUMIDITY ARE NOT EXPECTED THROUGH THE EARLY PORTION OF NEXT WEEK. && .PRELIMINARY POINT TEMPS/POPS... TPA 65 43 68 54 / 0 0 0 0 FMY 73 47 72 55 / 0 0 0 0 GIF 69 43 66 53 / 0 0 10 10 SRQ 67 44 68 54 / 0 0 0 0 BKV 65 38 67 49 / 0 0 0 0 SPG 65 48 67 56 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...BEACH HAZARDS STATEMENT THROUGH SUNDAY EVENING FOR COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1005 PM EST SUN FEB 14 2016 .SYNOPSIS... A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY. && .NEAR TERM /UNTIL 7 AM MONDAY MORNING/... COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO RIDGE INTO THE SOUTHEASTERN STATES. CLOUDS EXPECTED TO CONTINUE TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE SOUTHEASTERLY OFF THE ATLANTIC...AND WEAK ISENTROPIC UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND. POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED. && .SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE. CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE UPPER TROUGH TAKES A NEGATIVE TILT. NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND ADVISORY MAY BE NEEDED. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO 60S AND LOWS IN THE 30S AND 40S. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF THE TAF PERIOD. MVFR CIGS ACROSS THE TAF SITES AT 03Z WITH EASTERLY WINDS 5 TO 10 KNOTS. THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. HOWEVER...ALL MODELS INDICATE IFR/LIFR CONDITIONS DEVELOPING BY 16/00Z. THE NAM MODEL CONTINUES TO INDICATE THE POSSIBILITY OF LLWS AFTER 06Z AS A 30 TO 35 KNOT LOW LEVEL JET MOVES INTO THE AREA. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS. MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS. EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FREEZING RAIN ADVISORY UNTIL NOON EST MONDAY FOR SCZ015-016. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
658 PM EST SUN FEB 14 2016 .SYNOPSIS... A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO RIDGE INTO THE SOUTHEASTERN STATES. CLOUDS EXPECTED TO CONTINUE TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE SOUTHEASTERLY OFF THE ATLANTIC...AND WEAK ISENTROPIC UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND. POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE. CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE UPPER TROUGH TAKES A NEGATIVE TILT. NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND ADVISORY MAY BE NEEDED. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO 60S AND LOWS IN THE 30S AND 40S. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... MVFR CIGS DEVELOPING ACROSS THE TAF SITES THIS EVENING. MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS. CIGS LOWERING TO MVFR IN THE 02Z-06Z TIME-FRAME. THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. WINDS WILL BE EASTERLY 10 KNOTS OR LESS. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS. THE NAM MODEL DOES INDICATE THE POSSIBILITY OF LLWS AFTER 06Z AS A 30 TO 40 KNOT LOW LEVEL JET MOVES INTO THE AREA. EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015- 016. && $$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
631 PM EST SUN FEB 14 2016 .SYNOPSIS... A SURFACE RIDGE EXTENDING THROUGH THE FORECAST WILL SHIFT OFF THE COAST TONIGHT. A WARM FRONT WILL DEVELOP SOUTH OF THE FORECAST AREA TONIGHT. THE FRONT WILL LIFT NORTHWARD AND INTO THE AREA MONDAY AHEAD OF A COLD FRONT. THE COLD FRONT WILL MOVE THROUGH THE REGION LATE MONDAY NIGHT AND EARLY TUESDAY. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... COLD AND DRY HIGH PRESSURE CENTERED OVER NEW ENGLAND CONTINUES TO RIDGE INTO THE SOUTHEASTERN STATES WITH DEWPOINTS IN THE SINGLE DIGITS ACROSS THE FORECAST AREA. CLOUDS EXPECTED TO CONTINUE TO INCREASE THROUGH THE NIGHT AS LOW LEVEL FLOW BECOMES MORE SOUTHEASTERLY OFF THE ATLANTIC AFTER 00Z AND WEAK ISENTROPIC UPGLIDE OVERSPREADS THE COLD DOME OF HIGH PRESSURE IN PLACE. THE CLOUD COVER WILL ACTUALLY HELP TEMPERATURES REMAIN SOMEWHAT STEADY OVERNIGHT ALTHOUGH PERSISTENT NORTHEASTERLY FLOW WILL USHER IN SOME COOLER AIR ACROSS THE NORTHERN MIDLANDS AS AN IN SITU COLD AIR DAMMING WEDGE DEVELOPS. MOISTURE WILL REMAIN VERY SHALLOW IN THE LOWEST 4000-5000FT WITH DRY AIR ALOFT AND NO MOISTURE IN THE SNOW GROWTH AREA. NO DYNAMICAL FORCING OVERNIGHT WITH THE ONLY LIFT OCCURRING FROM ISENTROPIC UPGLIDE. THINK MUCH OF ANY PRECIPITATION OVERNIGHT WILL FALL AS VIRGA AND GO INTO SATURATING THE NEAR SURFACE LAYER WITH LITTLE IF ANY REACHING THE GROUND. POPS INCREASE AFTER 06Z INTO THE CHANCE RANGE BY EARLY MORNING AND SOUNDINGS INDICATE PREDOMINATE PTYPE WOULD BE FREEZING RAIN/DRIZZLE BUT MINIMAL IMPACTS EXPECTED. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... MODEL FORECAST THERMAL PROFILES CONTINUE TO SUPPORT VERY LIGHT FREEZING RAIN/DRIZZLE MAINLY ALONG AND NORTH OF A LINE FROM MANNING TO AIKEN TO MCCORMICK DURING THE 12Z-15Z TIME FRAME BEFORE SURFACE TEMPS BEGIN TO WARM ABOVE FREEZING FROM SOUTHEAST TO NORTHWEST AS STRONG WARM ADVECTION AHEAD OF THE APPROACHING SYSTEM ERODES THE WEDGE. CANNOT RULE OUT A TRACE OF ICE ACCUMULATION ACROSS THE NORTHERN MIDLANDS AND AFTER COLLABORATION WITH NEIGHBORING OFFICES DECIDED TO POST A FREEZING RAIN ADVISORY FOR LANCASTER AND CHESTERFIELD COUNTIES ENDING AT 17Z. THINK IMPACTS WILL BE MINIMAL WITH ANY ICING OCCURRING ON ELEVATED SURFACES AND THERE IS A POSSIBILITY THAT LITTLE ACCUMULATION OCCURS AT ALL GIVEN THE LACK OF DEEPER MOISTURE AVAILABLE. CHANCES OF RAIN INCREASE THROUGH THE AFTERNOON INTO EVENING AS THE UPPER TROUGH AMPLIFIES TO OUR WEST AND UPPER FORCING/ASCENT INCREASE FROM WEST TO EAST. GENERALLY EXPECT A LULL IN PRECIP FROM MID MORNING THROUGH LATE AFTERNOON AND THEN POPS RAMP UP TO CATEGORICAL OVERNIGHT. POTENTIAL FOR PERIODS OF HEAVY RAIN AS STRONG SOUTHERLY 50-55KT LOW LEVEL JET PROVIDES AMPLE MOISTURE TRANSPORT INTO THE REGION. CANNOT RULE OUT AN ISOLATED ELEVATED THUNDERSTORM AS LAPSE RATES BECOME STEEP AND CROSS TOTALS REMAIN HIGH...ALTHOUGH SURFACE BASED INSTABILITY IS RELATIVELY NON-EXISTENT. AVERAGE RAINFALL AMOUNTS COULD RANGE FROM A QUARTER INCH TO AS MUCH AS 0.75 INCHES DUE TO INCREASED FORCING AS THE UPPER TROUGH TAKES A NEGATIVE TILT. NON STANDARD TEMPERATURE TREND EXPECTED WITH TEMPS RISING LATE AFTERNOON AND OVERNIGHT MONDAY NIGHT DUE TO WARM ADVECTION AHEAD OF THE SURFACE LOW. BREEZY CONDITIONS ALSO LIKELY AND A LAKE WIND ADVISORY MAY BE NEEDED. && .LONG TERM /TUESDAY THROUGH SUNDAY/... A SHORTWAVE TROUGH EMBEDDED IN THE UPPER TROUGH OVER THE EASTERN PART OF THE COUNTRY WILL EJECT EAST ACROSS THE FORECAST AREA TUESDAY MORNING. THIS WILL DRIVE A COLD FRONT EAST THROUGH THE FORECAST AREA EARLY TUESDAY. THE GFS MOVES THE MOISTURE OUT OF THE AREA MORE QUICKLY THAN THE NAM AND IS WARMER WITH HIGH TEMPERATURES ON TUESDAY. LEANED TOWARD THE GFS AND HAVE POPS GRADUALLY DECREASING AFTER 12Z AND POPS LESS THAN 15 BY 18Z. THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH ANOTHER MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY NIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE SOUTHEASTERN US BEHIND THE FRONT WITH A MUCH DRIER AIRMASS RETURNING THROUGH THE END OF THE WORK WEEK. SURFACE LOW PRESSURE OVER SOUTHEASTERN CANADA IS EXPECTED TO BRING THE NEXT FRONTAL BOUNDARY NEAR THE AREA THIS WEEKEND. TEMPERATURES WILL GENERALLY BE NEAR TO ABOVE NORMAL THROUGH THE LONG TERM PERIOD WITH HIGHS IN THE UPPER 50S TO 60S AND LOWS IN THE 30S AND 40S. && .AVIATION /00Z MONDAY THROUGH FRIDAY/... MVFR CIGS DEVELOPING ACROSS THE TAF SITES THIS EVENING. MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA TONIGHT AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS. CIGS LOWERING TO MVFR IN THE 02Z-06Z TIME-FRAME. THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. WINDS WILL BE EASTERLY 10 KNOTS OR LESS. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS. THE NAM MODEL DOES INDICATE THE POSSIBILITY OF LLWS AFTER 06Z AS A 30 TO 40 KNOT LOW LEVEL JET MOVES INTO THE AREA. EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FREEZING RAIN ADVISORY FROM 1 AM TO NOON EST MONDAY FOR SCZ015- 016. && $$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1128 PM CST FRI FEB 12 2016 .UPDATE... ISSUED AT 859 PM CST FRI FEB 12 2016 Skies have become clear this evening and should remain that way the rest of the night. Any additional clouds will be very late tonight or early tomorrow morning and be cirrus clouds. Winds remain gusty and am expecting this to continue as forecast as well. Gusty winds will keep air mixed, but dewpoints are in the single digits over most of the area, so still think temps by morning will be in the single digits to just below zero in the northwest. Only change needed is to adjust cloud cover to better reflect current conditions. Update will be out shortly. && .SHORT TERM...(Tonight) ISSUED AT 255 PM CST FRI FEB 12 2016 A weak clipper system will exit southeast of central IL late this afternoon, with its diminishing area of very light snow/flurries se of the IL river ending soon, with best light snow chances east of IL over central IN. MVFR clouds already scattering nw of the IL river like at PIA and HRRR model handling this clearing well. These clouds to decrease se of the IL river during late afternoon/early evening, and over southeast IL by mid evening. Brisk NW winds of 15-25 mph and gusts to 30 mph will gradually diminish during the night, reaching 5-15 mph later tonight. Strong 1046 mb polar high pressure west of Lake Winnipeg Canada to settle se into MN/IA by sunrise Sat and bring a frigid night to the region. Lows by early Saturday morning range from around zero north of I-72 to 4-8F in southeast IL from I-70 southeast. Wind chills by dawn will range from 5-15 below zero with a few spots from I-74 north dipping to 15-17 below zero like at Bloomington, Galesburg and Champaign. Will hold off on a wind chill advisory overnight into mid Sat morning, but will issue SPS to address these bitter cold wind chills especially in our northern CWA. .LONG TERM...(Saturday through Friday) ISSUED AT 255 PM CST FRI FEB 12 2016 Very cold conditions expected to start the day Saturday across central and southeast Illinois as Arctic high pressure builds across the area. The relatively slight pressure gradient that will accompany the surface high should keep Wind Chill values warmer than advisory criteria for the most part, but high temperatures should only top out in the teens. Beyond the initially cold conditions, our attention turns to an approaching clipper system, which is likely to be the most significant weather system to impact the area over the next week. This clipper has trended faster in recent model runs, with snow now expected to start breaking locally after midnight Saturday night/Sunday morning. The system will be pushing into a very dry airmass which should limit the snow accumulation to some degree. However, fairly strong isentropic ascent and mixing ratios of 2-3 G/KG over at least a 12 hour period should be able to produce 2"=4" snow totals. In fact, would not be surprised if we need to boost accumulations further once the exact track of the system is more clear (it has trended s bit south in the latest runs). One other thing that will need to be monitored is that the moisture depth is progged to be rather shallow during the period of potential snow. This fact is also a reason to limit snow accumulations for now, and we also need to monitor the threat for freezing drizzle due to a potential lack of ice crystals. The faster trend of the clipper system should now have Monday ending up dry. Another weak clipper system may impact the area Tuesday into Tuesday night, but it does not appear significant at this time. After that, the next chance for precipitation should not occur before the end of the week. However, model agreement in the details of the late week system is weak at best. Temperatures should gradually be trending warmer next week, with well above normal temperatures likely by the end of the week (near 50 degrees for highs). If these trends hold, the late week system, if/when it impacts the area, should be a rain producer. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) ISSUED AT 1128 PM CST FRI FEB 12 2016 VFR conditions will continue at all TAF sites next 24hrs. Clear skies will continue overnight and through the afternoon. Models bring in some high cirrus late tomorrow afternoon/early evening in advance of the next weather system. The cirrus will thicken during the evening hours, followed by some mid clouds around 12kft reaching SPI and DEC later in the evening. Winds still a tad gusty but not too bad so will not have any gusts in this forecast. Winds will become lighter through the morning hours and then become light and variable during the early evening. Later in the evening winds will increase in speed some, but only reaching around 4-5kts. Wind direction will continue to be northwest through the night but then switch so southeast during the evening after the ridge goes by. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...Auten SHORT TERM...07 LONG TERM...BAK AVIATION...Auten
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1241 AM EST SAT FEB 13 2016 .SYNOPSIS... ISSUED AT 1235 AM EST SAT FEB 13 2016 THIS WEEKEND WILL FEATURE COLD TEMPERATURES WITH HIGHS INTO THE MID TEENS TODAY AND NEAR 20 ON SUNDAY. LOWS TONIGHT WILL LIKELY FALL TO NEAR ZERO DEGREES. LAKE EFFECT SNOW SHOWERS AND AREAS OF BLOWING SNOW WILL CONTINUE TO IMPACT AREAS ACROSS FAR NORTHERN INDIANA AND SOUTHWEST LOWER MICHIGAN TODAY...WITH LIGHTER FLURRIES AND SNOW SHOWERS POSSIBLE ELSEWHERE. HIGH PRESSURE BRIEFLY BUILDS IN FOR TONIGHT AND SUNDAY MORNING BEFORE SNOW CHANCES RETURN LATER SUNDAY INTO EARLY MONDAY. TEMPERATURES WILL MODERATE CLOSER TO NORMAL NEXT WEEK WITH SEVERAL CHANCES FOR LIGHT PRECIPITATION. && .UPDATE... ISSUED AT 734 PM EST FRI FEB 12 2016 POST FNTL SHSN WITHIN EMERGING ARCTIC AIRMASS QUITE INTENSE IN SPOTS YET THIS EVENING BUT WILL CONT TO DIMINISH AS UNSTABLE SFC BASED LAPSE RATES DECAY W/SUNSET. REGARDLESS GROWING QUITE CONCERNED W/UPSTREAM LAKE RESPONSE WITHIN EVOLVING/INTENSIFYING LL THERMAL TROUGH. GENERAL CONSOLIDATION IN BANDING NOTED OVR THE LAST 3 HOURS ALG A MUSKEGON TO ALLEGAN LINE...MIMICKING RECENT RAP MODEL INDICATIONS AS LL FLW VEERS CONSIDERABLY W/UPSTREAM EXTENT. THIS PRIMARY PLUME XPCD/MODELED TO INTENSIFY AS IT COMES SOUTH THROUGH LT EVENING BFR LOCKING IN WITHIN ROUGHLY ALG A SOUTH HAVEN...CASSOPOLIS...ELKHART...WARSAW LINE. BASED ON OBSVD RADAR TRENDS...SUSPECT NR 1" PER HOUR PEAK SNOWFALL RATES WHICH MAY REQUIRE SOME FORM OF HEADLINE ADJUSTMENT. WILL ATTM FOLLOW EVOLUTION OF THIS BAND THROUGH MID EVENING AND MAKE A DECISION IF NEEDED WELL BFR 11 PM. && .SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 CDFNT MOVG RAPIDLY E-SE ACROSS THE CWA THIS AFTN ACCOMPANIED BY A BAND OF SNOW SHOWERS. LAKE EFFECT SNOW SHOWERS DVLPG BEHIND THE FRONT SHOULD GRDLY INTENSIFY THIS EVE AS CAA CONTS AND WINDS VEER FROM AROUND 300 DEGREES TO 340 DEGREES AS A SECONDARY CDFNT CURRENTLY OVER NRN LWR MI MOVES THROUGH OUR AREA. INVERSION BASE FORECAST TO PEAK LATE THIS EVE AROUND 6500FT WITH SIGNIFICANT LAKE INDUCED INSTABILITY (0-2KM THETA-E LAPSE RATES OVER THE LAKE AROUND -2.5C/KM). CONVECTION ALLOWING MODELS SUGGEST A DOMINANT BAND OR TWO WILL SET UP AROUND THIS TIME IMPACTING NORTHWEST PORTION OF OUR CWA. HWVR, THESE OPTIMAL CONDITIONS FOR LES SHOULD BE SHORT LIVED AS INVERSION FCST TO LOWER/LAKE INDUCED INSTABILITY DECREASE LATE TONIGHT AND THROUGH THE DAY SATURDAY. DGZ WILL ALSO BE VERY LOW GIVEN ARCTIC AIRMASS MOVG IN WHICH SHOULD LIMIT ACCUMS BLO WHAT OTRWS MIGHT BE EXPECTED. ONLY MINOR CHANGE MADE TO PREVIOUS FCST ACCUMS WITH TOTALS TONIGHT AND SATURDAY EXPECTED TO BE IN THE 3-6" RANGE IN THE ADVISORY AREA WITH 1-3" IN COUNTIES SURROUNDING ADVISORY AND <1" OVER THE REST OF THE CWA. LOCALLY HIGHER AMOUNTS PSBL IF DOMINANT BAND PERSISTS OVER ANY GIVEN AREA VERY LONG THIS EVENING. BOUNDARY LAYER WINDS FCST 15-25KT TONIGHT WHICH SHOULD CAUSE CONSIDERABLE BLOWING DRIFTING OF THE POWDERY LES, MAINLY IN THE NW ADVISORY AREA. LITTLE CHANGE MADE TO TEMPS WITH LOWS TONIGHT IN THE 0-5 RANGE NE AND SW WHERE SOME PARTIAL CLEARING EXPECTED AND 5-10 UNDER THE LAKE EFFECT CLOUD PLUME OVER MOST OF THE REST OF THE CWA, WITH HIGHS SATURDAY ONLY 12-16. MINIMUM WIND CHILLS TONIGHT AND SATURDAY MORNING EXPECTED TO BE IN THE -5 TO -15 RANGE. && .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 306 PM EST FRI FEB 12 2016 LAKE EFFECT SNOW WILL TAPER OFF SATURDAY EVENING AS LOW LEVEL RIDGE AXIS SHIFTS OVERHEAD AND INVERSION HEIGHTS LOWER. DGZ REMAINS ACTIVE IN THE 00-06Z TIMEFRAME SO SOME LIGHT FLURRIES/SNOW SHOWERS EXPECTED BUT ANY ADDITIONAL ACCUMULATION WILL BE VERY LIGHT. MAIN STORY FOR SATURDAY NIGHT WILL BE VERY COLD TEMPS. LIGHT WINDS...PARTIALLY CLEAR SKIES...AND FRESH SNOW WILL SUPPORT GOOD RADIATIONAL COOLING POTENTIAL IN SPOTS. GRADIENT WIND/WAA AND CLOUDS BEGIN TO INCREASE TOWARD 12Z BUT SHOULD STILL BE ENOUGH TIME FOR TEMPS TO DROP. KEPT CLOSE TO INHERITED FORECAST...WHICH IS ON THE COLD SIDE OF GUIDANCE...WITH LOWS AROUND ZERO. WILL LIKELY BE A HIGH DEGREE OF VARIANCE IN FINAL NUMBERS THOUGH...DEPENDING ON EXACT CLOUD TRENDS. CHANCE FOR LIGHT SNOW THEN QUICKLY RETURNS LATE SUNDAY AS NEXT SHORTWAVE ROTATES THROUGH THE REGION. CONFLUENT FLOW OVER THE EASTERN CONUS WILL INCREASINGLY SHEAR OUT AND WEAKEN THIS WAVE. CVA BECOMES NEGLIGIBLE BY SUNDAY NIGHT WITH JUST SOME BROAD/WEAK 280- 285K ISENTROPIC ASCENT. DO SEE A DECENT MOISTURE SURGE THOUGH WITH MIXING RATIOS OVER 2 G/KG. GIVEN STEADY...ALBEIT WEAK...ASCENT AND POTENTIAL FOR HIGHER THAN CLIMO SNOW RATIOS...COULD CHURN OUT 1-2" BY LATE MONDAY MORNING. BEST CHANCES FOR HIGHER AMOUNTS WILL BE IN OUR SOUTHWEST WHERE BETTER MOISTURE AND FORCING RESIDE. AFTER A BRIEF BREAK MONDAY NIGHT...THERE IS ANOTHER CHANCE FOR SNOW TUESDAY/TUESDAY NIGHT AS POTENT NORTHERN STREAM SHORTWAVE DIVES SOUTHEAST AND STRENGTHENS EAST COAST LOW. MODELS HAVE BEEN KEEPING PRECIP SHIELD OF PRIMARY LOW JUST EAST OF OUR CWA BUT CONTINUE TO STRUGGLE IMMENSELY WITH EXACT TRACK OF SECONDARY VORT MAX. CONFIDENCE IN SNOW CHANCES REMAINS LOW AT THIS POINT WITH PARENT JET ENERGY STILL WELL OUT OVER THE DATA-SPARSE NORTH PACIFIC. WILL CONTINUE TO WATCH THIS PERIOD AND ADJUST AS MODELS GET A BETTER HANDLE ON SITUATION. SOME MINOR LAKE EFFECT THEN POSSIBLE WEDNESDAY WITH MUCH WARMER TEMPS (AND POTENTIAL FOR RAIN) STILL EXPECTED BY THE END OF THE WEEK. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1235 AM EST SAT FEB 13 2016 NW FLOW LAKE EFFECT EVENT WILL CONTINUE TO PROVIDE VARIABLE FLIGHT CONDITIONS AT KSBN THROUGH THE MORNING (VIS MAINLY IFR WITH TIMES OF MVFR/LIFR)...WITH GRADUAL IMPROVEMENT ANTICIPATED THIS AFTERNOON AS FLOW BACKS ALLOWING FOR DRY AIR ENTRAINMENT INTO SHRINKING BOUNDARY LAYER. KFWA LIKELY TO GET CLIPPED BY PRIMARY LAKE EFFECT BAND THROUGH 07Z WITH MVFR/IFR CONDITIONS ANTICIPATED. IMPROVEMENT TO VFR/LIGHTER WINDS THEN EXPECTED FOR THE REMAINDER OF THE NIGHT AT KFWA...WITH SCT SHSN/FLURRIES FILLING BACK IN DURING THE DAY. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR INZ003>005. MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ077>079. OH...NONE. LM...HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ043-046. GALE WARNING UNTIL 7 AM EST THIS MORNING FOR LMZ043-046. && $$ UPDATE...T SYNOPSIS...STEINWEDEL SHORT TERM...JT LONG TERM...AGD AVIATION...STEINWEDEL VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSNORTHERNINDIANA WWW.TWITTER.COM/NWSIWX WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
405 AM CST SAT FEB 13 2016 .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 348 AM CST SAT FEB 13 2016 Areal expansion of stratus will be the main forecast challenge heading through the morning hours, and should have a significant impact of temperature trends through the day across the far north. Some southeastward development of freezing fog is not out of the question this morning, however the probability for freezing drizzle in these areas of stratus is not looking quite as probable at this time. A large temperatures gradient is expected this afternoon in excess of 30 degrees from the Elkhart area which should be in the 60s...to Hays where highs will not likely exceed the 30s. A shortwave now moving into the northern Rockies will affect the northern and central high plains region by the overnight, having very little impact on western Kansas other than pushing a cold front/wind shift across the region before Sunday morning. .LONG TERM...(Sunday THROUGH Friday) ISSUED AT 348 AM CST SAT FEB 13 2016 Models have been consistent with a followup/secondary vort lobe rotating through a bit farther south about 24 hours later which will improve chances for rain or snow late Sunday night into very early Monday morning. The remainder of the forecast period will see rising thicknesses and more northwest flow aloft, resulting in a warming trend through at least Thursday. Could not rule out another 80 degree reading by Thursday as a warm dry downslope pattern once again develops and possibly critical fire weather conditions. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1209 AM CST SAT FEB 13 2016 The HRRR model develops/spreads near IFR stratus farther south across the area over the next few hours and maintains it through the mid to late moring hours. Freezing fog is not a given at any of the terminals this morning, as the HRRR indicates the best signal on the higher terrain in northeast CO, however we will monitor trend going foreward incase it develops farther east. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 30 56 31 / 0 0 0 10 GCK 52 29 57 30 / 10 0 0 10 EHA 65 36 58 32 / 0 0 0 10 LBL 57 32 58 30 / 0 0 0 10 HYS 36 27 51 31 / 10 0 10 20 P28 43 31 58 33 / 0 10 0 10 && .DDC Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Russell
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1226 AM CST SAT FEB 13 2016 ...UPDATED AVIATION SECTION... .SYNOPSIS... ISSUED AT 213 PM CST FRI FEB 12 2016 An upper level ridge of high pressure is located over the Rockies with a long wave trough over the east coast. This places the Central High Plains under northwest flow aloft. High to mid levels of the atmosphere over western Kansas are fairly dry leaving only a few high clouds visible across western Nebraska and northwest Kansas. Some of these clouds may make it into portions of west and west central Kansas this afternoon. As we head to the surface, low levels of the atmosphere are saturated across portions of central and western Kansas leading to a deck of low stratus extending north and east of a line from Colby to Kingman. This deck of clouds is slowly shifting southeast, however, these clouds are expected to dissipate over the next couple of hours. An area of low pressure with associated stationary front is sprawled out across eastern Colorado with a dome of high pressure filtering into the Northern Plains. This will lead to winds backing from the northeast this afternoon to more of an easterly direction this evening. && .SHORT TERM...(THIS EVENING THROUGH Saturday) ISSUED AT 1245 PM CST FRI FEB 12 2016 Low clouds are expected to form once again over north, west central, and north central Kansas tonight with mostly clear skies expected elsewhere. This deck of clouds may be thick enough for light freezing drizzle to fall, mainly north of Highway 96. Winds look to back form an easterly direction this evening, then shifting southeast by midnight. Low clouds are expected to extend into Oklahoma by sunrise tomorrow but then slowly dissipate by mid afternoon like we saw today. Winds take more of a southerly direction with an increase in speed tomorrow as the area of low pressure mentioned in the synopsis intensifies and slides into southeastern Colorado. The dome of high pressure will continue to build across Northern and Central Plains. As for temperatures, lows tonight look to range from the upper teens across north central Kansas to upper 20s across far southwestern Kansas. Highs tomorrow are anticipated to range from the mid 30s across north central Kansas to mid 60s across far southwestern Kansas. .LONG TERM...(Saturday NIGHT THROUGH Friday) ISSUED AT 213 PM CST FRI FEB 12 2016 The upper level ridge in mentioned in the short term gets pushed south Friday night into the weekend as a shortwave moves into the Intermountain West Saturday then Northern Plains Saturday night into Sunday. Cloudiness will increase in coverage as this system moves into the Plains Saturday night with decreasing cloudiness on Sunday. No precipitation is expected with this system due to lake of moisture. This system will also help push a cold front through the area shifting winds to more of a northerly direction. A second shortwave is progged to move through the area Sunday night into Monday once again increasing cloud cover across western Kansas. There may be enough low to mid level moisture to squeeze out some light rain or snow Sunday night but most likely we will stay dry. An upper level ridge builds into the western Untied States early into the mid part of next week. This will allow warmer temperatures to build back into the area but with the sacrifice of no measurable precipitation expected. Models then suggest another system moving into the area late next week but that being so far out it is hard to tell the exact track. As for temperatures, highs in the 50s are expected Sunday, then reaching to around 60 degrees Monday. Lows Saturday night will start out around 30 degrees, with lower 30s Sunday night and mid 30s Monday night. A warming trend continues through the week with highs starting out Tuesday ranging from upper 50s north to mid 60s south ending Thursday with highs ranging from the upper 60s north to around 80 degrees across far southwestern Kansas. Lows during this time frame start out in the mid 50s Tuesday night ranging from the upper 30s to mid 40s Thursday night. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Saturday NIGHT) ISSUED AT 1209 AM CST SAT FEB 13 2016 The HRRR model develops/spreads near IFR stratus farther south across the area over the next few hours and maintains it through the mid to late moring hours. Freezing fog is not a given at any of the terminals this morning, as the HRRR indicates the best signal on the higher terrain in northeast CO, however we will monitor trend going foreward incase it develops farther east. && .PRELIMINARY POINT TEMPS/POPS... DDC 45 30 56 32 / 0 0 10 20 GCK 52 30 57 31 / 10 0 10 20 EHA 64 37 58 33 / 0 0 10 10 LBL 57 32 58 32 / 0 0 10 10 HYS 36 27 52 31 / 10 0 10 20 P28 43 32 58 33 / 0 10 10 20 && .DDC Watches/Warnings/Advisories...NONE. && $$ SYNOPSIS...Hovorka_42 SHORT TERM...Hovorka_42 LONG TERM...Hovorka_42 AVIATION...Russell
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 PM EST SUN FEB 14 2016 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 419 PM EST SUN FEB 14 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW DEAMPLIFYING FLOW ACROSS N AMERICA. DEEP TROF THAT WAS OVER SE CANADA/NE CONUS 24HRS AGO IS LIFTING NE...LEAVING BEHIND A BROAD TROF OVER THE CNTRL AND ERN CONUS DOWNSTREAM OF A BROAD RIDGE CENTERED JUST OFF THE W COAST. A VIGOROUS LOOKING SHORTWAVE IS TRACKING ACROSS NRN IL. ASSOCIATED SHIELD OF SNOW HAS PASSED S OF THE AREA TODAY. UPSTREAM...SHORTWAVE TROF OVER MANITOBA/WRN MN WILL BE THE NEXT FEATURE OF INTEREST DURING THE SHORT TERM. MEANWHILE...INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF HIGH PRES NOW OVER THE LOWER LAKES/MID ATLANTIC STATES IS BRINGING LES NORTHWARD OFF LAKE MI UNDER 850MB TEMPS AROUND -16C ACROSS THE N HALF OF THE LAKE PER LATEST RAP ANALYSIS. SATELLITE AND RADAR IMAGERY INDICATE LES HAS NOT BEEN WELL ORGANIZED AS IT LIFTED N INTO THE SE FCST AREA THIS AFTN. THE HEAVIER SNOW HAS IMPACTED MENOMINEE COUNTY...BUT WEB CAMS SUGGEST SNOW ACCUMULATIONS HAVE BEEN UNDER 1 INCH. AFOREMENTIONED SHORTWAVE TROF ACROSS WRN MN WILL SHIFT E...REACHING CNTRL LAKE SUPERIOR/CNTRL UPPER MI AROUND 12Z MON. MODELS ARE IN GOOD AGREEMENT SHOWING A PERIOD OF DEEP LAYER FORCING PER QVECTORS AND A CORRESPONDING INCREASE IN DEEPER MOISTURE AHEAD OF FEATURE. THIS SHOULD YIELD AT LEAST SOME AREAS OF -SN MOVING ACROSS THE FCST AREA TONIGHT. OF MORE INTEREST IS WHAT HAPPENS DOWNWIND OF LAKE MI. WITH 850MB TEMPS OF -13/-14C ACROSS NRN LAKE MI...SYNOPTIC FORCING/DEEPER MOSITURE WILL LEAD TO A PERIOD OF LAKE ENHANCEMENT. IN ADDITION...AS WEAK SFC TROF ASSOCIATED WITH SHORTWAVE MOVES ACROSS THE AREA...THE CONVERGENCE ALONG THE TROF SHARPENS UP AS IT REACHES LAKE MI...LEADING TO A FOCUSING OF THE LAKE ENHANCED SNOW. FCST SOUNDINGS SHOW THE DGZ ENCOMPASSING A VERY DEEP LAYER 9-10FT THICK. WHILE MODELS DON`T SHOW MUCH UPWARD MOTION IN THAT LAYER DUE TO THE OVERALL WEAK SYNOPTIC FORCING...IT WILL STILL HELP FLUFF UP SNOW ACCUMULATIONS. SFC TROF STEADILY CROSSES NRN LAKE MI/SE FCST AREA ROUGHLY DURING THE 09Z-21Z TIME FRAME. STEADY PROGRESSION WILL LIMIT SNOW ACCUMULATIONS...BUT POTENTIAL IS THERE FOR SEVERAL INCHES OF SNOW. FOR NOW...FCST WILL SHOW TOTAL SNOW ACCUMULATION TONIGHT/MON OF 2-3 INCHES WITH LOCAL 4 INCH AMOUNTS FROM MENOMINEE COUNTY INTO LUCE COUNTY...SUB ADVY AMOUNTS. HOWEVER...WILL NEED TO MONITOR THE INCREASE IN ENHANCEMENT ALONG/JUST AHEAD OF THE SFC TROF. SINCE MUCH OF THE SNOW ACCUMULATION WILL OCCUR WITH THIS FEATURE AND OVER A RELATIVELY SHORT PERIOD OF TIME...THE HIGHER SNOWFALL RATES MAY REQUIRE ISSUANCE OF AN ADVY LATER. ELSEWHERE... SNOW ACCMULATIONS SHOULD BE UNDER 1 INCH. WITH PASSAGE OF SFC TROF...-SN WILL END. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 252 PM EST SUN FEB 14 2016 FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW- NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED MORNING). ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5 INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR SIGNIFICANT LAKE EFFECT. VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH POTENTIAL FOR SOME DISTURBANCES. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 646 PM EST SUN FEB 14 2016 AS A DISTURBANCE APPROACHES FROM THE WEST EXPECT CONDITIONS TO FALL TO MVFR IN -SN AT ALL TERMINALS THIS EVENING INTO THE OVERNIGHT HOURS. VSBY COULD OCCASIONALLY FALL TO IFR AT KSAW... WHICH WILL BE MORE INFLUENCED BY MOISTURE ADVECTING N OFF LAKE MI. WITH A DOWNSLOPE S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD IS LEAST LIKELY TO SEE ANY -SN. MVFR CONDITIONS WILL PERSIST THROUGH MON. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EST SUN FEB 14 2016 TIGHTENING PRES GRADIENT BETWEEN HIGH PRES NEAR THE E COAST AND A LOW PRES TROF APPROACHING FROM THE W WILL RESULT IN SOUTHERLY WINDS OF 20-30KT TONIGHT. THE STRONGEST WINDS WILL OCCUR OVER THE E HALF OF THE LAKE WHERE THERE MAY BE A FEW GALE FORCE GUSTS TO 35KT. WINDS WILL DIMINISH MON AS PRES GRADIENT WEAKENS. AFTER A PERIOD OF RELATIVELY LIGHT WINDS UNDER 20KT MON NIGHT/TUE MORNING...PASSAGE OF A COLD FRONT TUE WILL BRING A PERIOD OF STRONGER NORTHERLY WINDS OF 20-30KT. THERE MAY BE A PERIOD OF GALES OVER THE CNTRL PORTION OF THE LAKE TUE NIGHT IN ADDITION TO HEAVY FREEZING SPRAY. WINDS WILL THEN DIMINISH TO UNDER 20KT WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. STRONGER SSE WIND UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THIS HIGH SHIFTING TO THE E AND ANOTHER APPROACHING LOW PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
401 PM EST SAT FEB 13 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 401 PM EST SAT FEB 13 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A DEEP TROF OVER SE CANADA INTO THE NE CONUS WITH THE CORE OF THE COLDEST AIR WELL E OF HERE NOW. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS MOVING ACROSS THE NRN ROCKIES. CLOSER TO HOME...WITH LATEST RAP ANALYSIS SHOWING 850MB TEMPS ACROSS LAKE SUPERIOR RANGING FROM AROUND -19C W TO -25C E... LES CONTINUES. HOWEVER...UNDER RISING HEIGHTS/SUBSIDENCE... INVERSION IS DOWN TO AROUND 3KFT W AND 5KFT E. SO...LES IS LIGHT... BUT STILL EFFECTIVE AT REDUCING VIS OVER THE E DUE TO SMALL SNOWFLAKE SIZE. WELL AWAY FROM LAKE EFFECT...IT`S BEEN A MOSTLY SUNNY DAY OVER SCNTRL UPPER MI. LINGERING LIGHT LES WILL END FROM W TO E TONIGHT AS SFC HIGH PRES RIDGE PASSES ACROSS THE FCST AREA. WITH MODERATING AIR MASS RESULTING IN THE DGZ LIFTING INTO THE SHALLOW CONVECTIVE LAYER...MIGHT BE ABLE TO FLUFF UP AN INCH OR TWO OF SNOW ACCUMULATION WHERE STRENGTHENING LAND BREEZES FOCUS CONVERGENCE... MOST LIKELY IN THE E HALF OF ALGER/NRN SCHOOLCRAFT COUNTIES. RIDGE WILL ARRIVE OVER WRN UPPER MI EARLY THIS EVENING AND THE E OVERNIGHT. LOSS OF LAKE EFFECT CLOUDS WITH BACKING WINDS WILL BE REPLACED BY SOME INCREASE IN HIGH CLOUDS IN WAA PATTERN AHEAD OF SHORTWAVE MOVING INTO THE NRN/CNTRL PLAINS. THAT SAID...ALL AREAS WILL SEE AT LEAST A SHORT PERIOD OF VERY GOOD RADIATIONAL COOLING CONDITIONS. IT STILL APPEARS THE CNTRL FCST AREA WILL HAVE THE LONGEST PERIOD OF EXCELLENT RADIATIONAL COOLING DUE TO CLEAR SKIES TO START THE EVENING...LATER ARRIVAL OF HIGH CLOUDS AND LONGER PERIOD OF LIGHT/CALM WIND. AS WITH PREVIOUS FCSTS...MAINTAINED A MIN TEMP FCST AT OR BLO THE LOWEST GUIDANCE WITH THE TRADITIONAL COLDEST SPOTS FALLING TOWARD -20F. MOST IF NOT ALL LOCATIONS WILL FALL BLO 0F. ON SUN...SHORTWAVE MOVING OUT OVER THE PLAINS TONIGHT WILL TRACK ESE WITH ASSOCIATED DEEP LAYER FORCING PER QVECTORS AND BEST ISENTROPIC ASCENT PASSING S OF UPPER MI. MODEL TREND OF RECENT DAYS TO PUSH FORCING/PCPN FARTHER S HAS HELD UP IN LATEST MODEL RUNS. AS A RESULT...DO NOT EXPECT ANY -SN ASSOCIATED WITH THIS FEATURE TO REACH THE FCST AREA SUN. ATTENTION THEN TURNS TO LES OFF LAKE MICHIGAN UNDER DEVELOPING/INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF DEPARTING HIGH PRES. 850MB TEMPS AROUND -17C AT 12Z RISE TO AROUND -14C BY 00Z MON...CERTAINLY LOW ENOUGH TO SUPPORT LES. LARGE SCALE ANTICYCLONIC FLOW AND INVERSIONS AT 4-5KFT WILL LIMIT INTENSITY OF LES. IN ADDITION...MOST HIGH RES MODEL GUIDANCE DEPICT THE LES MOSTLY AS A BAND LIFTING N ON A WIND CONVERGENCE ZONE. WHILE THIS MAY LEAD TO A BURST OF MDT SNOWFALL...ESPECIALLY WITH DGZ SOLIDLY IN THE CONVECTIVE LAYER...THE HEAVIER SNOW WOULD NOT LAST LONG. FOR NOW...EXPECT SNOW ACCUMULATIONS UNDER 1 INCH...BUT NOT OUT OF THE QUESTION FOR LOCALIZED INCH OR TWO OF SNOW ACCUMULATION IF THE CONVERGENCE ZONE IS STRONG. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 320 PM EST SAT FEB 13 2016 LONG TERM STARTS 00Z MON WITH A SHORTWAVE NEAR SRN LAKE MICHIGAN THAT WILL CROSS LAKE HURON BY 12Z MON AND THEN MOVE INTO QUEBEC...AND ANOTHER SHORTWAVE OVER CENTRAL MN THAT WILL MOVE OVER OR JUST S OF THE CWA LATE SUN NIGHT INTO MON AFTERNOON...AND YET ANOTHER SHORTWAVE WILL FOLLOW THE SECOND BY ABOUT 12 HOURS. NOT REALLY LOOKING FOR A LOT OF SYNOPTIC QPF...BUT THE FORCING/MOISTURE WILL ENHANCE LES OFF LAKE MICHIGAN IN THE SLY FLOW AHEAD OF THE ACCOMPANYING SFC TROUGH. SLY WIND LAKE EFFECT IS ALWAYS TRICKY...BUT LOOKS LIKE IT SHOULD START UP AROUND 00Z MON AND REACH A PEAK BETWEEN 06Z AND 18Z MON WHILE SHIFTING E AND ENDING BEFORE 00Z TUE. AT THIS POINT...IT LOOKS LIKE THE MOST SNOW WILL FALL ACROSS MENOMINEE...DELTA...AND SCHOOLCRAFT COUNTIES...AND POSSIBLY INTO COUNTIES JUST N OF THOSE. THINK WITH S WINDS...THINK MENOMINEE COUNTY SEEING MUCH LES IS NOT AS LIKELY. OVERALL...ONLY EXPECTING 2 TO MAYBE 3 INCHES IN THESE AREAS. ELSEWHERE...AROUND AN INCH OR LESS. MAY SEE SOME LIGHT LES OVER W WIND SNOWBELTS MON NIGHT INTO TUE MORNING AS 850MB TEMPS WILL BE MARGINAL BUT ADDITIONAL SHORTWAVE WILL PROVIDE SOME ENHANCEMENT. NOT LOOKING AT SIGNIFICANT AMOUNTS. SFC TROUGH MOVES THROUGH TUE AHEAD OF AN UPPER WAVE. THIS TURNS WINDS OUT OF THE NW-NNW BY TUE AFTERNOON/EVENING AND DROPS 850MB TEMPS TO AROUND-15Z BY 00Z WED AND -19C BY 12Z WED. A SFC RIDGE MOVES THROUGH BY 00Z THU...ENDING MOST OR ALL LES. NOT EXPECTING SIGNIFICANT SNOWFALL AMOUNTS GIVEN CHANGING WIND DIRECTIONS AND QUICK ENTRANCE OF THE RIDGE. COULD SEE A MORE POTENT SYSTEM LATE IN THE WEEK...WITH THE POSSIBILITY OF SNOW...RAIN...AND FREEZING RAIN. HOWEVER...CONFIDENCE EVEN IN THE GENERAL STRENGTH/TRACK OF THE SYSTEM IS LOW AS MODELS VARY FROM RUN TO RUN AND DISAGREE MODEL TO MODEL. CERTAINLY LOOKS LIKE A WARMUP IS IN STORE FOR AT LEAST THU NIGHT AND FRI...BUT CAN NOT SAY MUCH ELSE WITH CONFIDENCE. MAINLY WENT WITH A WINTRY MIX OF PRECIP IN THE FORECAST...WITH CONSENSUS POPS FIELDS OTHERWISE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1244 PM EST SAT FEB 13 2016 WITH WINDS BACKING AS HIGH PRES MOVES E...CROSSING UPPER MI TONIGHT...LINGERING LAKE EFFECT SNOW SHOWERS AFFECTING KCMX WILL END TONIGHT. UNTIL THEN...EXPECT IFR VIS TO PREVAIL THIS AFTN. HOWEVER...AS IS TYPICAL FOR LAKE EFFECT...CONDITIONS WILL BE QUITE VARIABLE AT TIMES...RANGING FROM BRIEF LIFR TO BRIEF MVFR. EXPECT IMPROVEMENT TO MVFR AT KCMX THIS EVENING...THEN VFR OVERNIGHT. AT KIWD...LAST OF THE STRATOCU/MVFR CIGS OFF THE LAKE SHOULD EXIT WITHIN THE NEXT HR OR SO...LEAVING VFR CONDITIONS TO PREVAIL THRU THE REMAINDER OF THE FCST PERIOD. AT KSAW...THERE MAY BE OCNL MVFR CIGS THIS AFTN. OTHERWISE...VFR CONDITIONS WILL BE THE RULE THRU THE FCST PERIOD. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 401 PM EST SAT FEB 13 2016 AS HIGH PRES RIDGE PASSES ACROSS LAKE SUPERIOR TONIGHT...WINDS WILL DIMINISH AND BECOME LIGHT UNDER 15KT FOR A TIME. ONCE THIS HIGH SHIFTS E OF THE AREA...S WINDS WILL INCREASE UP TO 25-30KT SUN INTO MON MORNING UNDER THE TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND AN APPROACHING LOW PRES TROF IN THE PLAINS. THERE COULD BE A FEW GALE FORCE GUSTS SUN NIGHT OVER THE E HALF OF THE LAKE. ALTHOUGH WINDS WILL DIMINISH LATER MON...ANOTHER ROUND OF STRONG NNW WINDS UP TO 30KT WILL DEVELOP TUE/TUE NIGHT FOLLOWING A COLD FRONTAL PASSAGE. NOT OUT OF THE QUESTION THERE COULD BE A FEW GALE FORCE GUSTS. WINDS WILL THEN DIMINISH WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006- 007-085. LAKE SUPERIOR... HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265>267. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
958 PM CST SUN FEB 14 2016 .UPDATE: Issued at 957 PM CST Sun Feb 14 2016 There may be some patchy freezing drizzle still over parts over south central Illinois this evening. Recent radar trends have been showing returns over this area that as it moves east, and recent runs of the RAP are showing a drying trend at and above 925mb after 06Z, so will carry patchy freezing drizzle until midnight. Otherwise, have been seeing an increase in lowering visibilities over the southern and eastern counties this evening, so went ahead and introduced areas of fog for the rest of the the night. Britt && .SHORT TERM: (Through Late Tonight) Issued at 219 PM CST Sun Feb 14 2016 Most of the snow has shifted east of our forecast area this afternoon as the shortwave was moving eastward into northwest IL. Will keep the winter weather advisory going for parts of west central and southwest IL until 6 pm due to patchy freezing drizzle. The threat for patchy freezing drizzle should end later this evening as the low level stratus cloud deck shifts east of the area. Mid-high level cloudiness will spread back into the area late tonight as another shortwave dives southeastward through the Plains. Went a little colder than MOS temperature guidance for tonight due to the new snow cover over much of the area. Rest of the forecast still looks on track. GKS .LONG TERM: (Monday through Next Sunday) Issued at 219 PM CST Sun Feb 14 2016 A shortwave and an associated surface low will pass south of our area on Monday. Precipitation with this feature should remain south of the forecast area, but the GFS model does generate a few areas of light QPF over our region on Monday. Could not rule out some patchy light rain/snow over our area on Monday. Temperatures will be noticeably warmer on Monday, finally getting well above the freezing mark for much of the area after a cold weekend. A strong northwest flow shortwave and associated weak surface low will be dropping southeastward through our area late Monday night and Tuesday bringing another shot of rain/snow to the area. The NAM and GFS models are similar in generating most of their QPF across northeast MO and west central and southwest IL, but the ECMWF model continues to have a more southwest track to the weather system and has most of its QPF west of the Mississippi River. For now will lean toward the NAM and GFS model solutions and put my highest pops over northeast MO and west central and southwest IL. Although temperatures will be fairly warm again on Tuesday there will be the potential for a little accumulating snow late Monday night and Tuesday morning across northeast MO and west central IL. The models continue to depict unseasonably warm and windy conditions for the end of the work week as an upper level ridge moves over the region on Thursday, along with strong south- southwesterly winds due to a tight surface pressure gradient over our area ahead of a low pressure system moving eastward through the northern Plains. Our next chance of measurable rain should occur mainly Saturday night as a weak low pressure system moves eastward through southern portions of MO and IL. GKS && .AVIATION: (For the 00z TAFs through 00z Monday Evening) Issued at 544 PM CST Sun Feb 14 2016 Expect mainly dry conditions through the period. VFR ceilings currently moving in over west central Missouri will likely move into KCOU and the St. Louis area terminals during the evening hours. MVFR or IFR ceilings will likely persist at KUIN most of the evening and overnight hours. Some MVFR visibilities in BR will likely redevelop late tonight and early monday morning before VFR conditions prevail by late Monday morning. Generally light winds are expected. Specifics for KSTL: Expect mainly dry conditions through the period. MVFR ceilings are expected to lift to VFR during the overnight hours though some MVFR BR is expected to develop late tonight and early on Monday. VFR conditions are then expected to prevail by mid-late morning. Britt && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
328 PM CST SAT FEB 13 2016 .DISCUSSION... Issued at 327 PM CST SAT FEB 13 2016 Main forecast challenges deal with weather type and headlines. The forecast area is really being split by wintry weather, both spatially and temporally, with snowfall in our northeast and light freezing drizzle in our south. The snowfall will likely start earlier (late this evening) than the freezing drizzle, which may hold off unto closer to sunrise. Strong isentropic ascent will eventually saturate the lowest several thousand feet of the atmosphere in north central to northeastern Missouri. Have delayed onset of snow several hours based on forecast soundings,the large temperature/ dewpoint depressions on surface observations and the relatively high cloud bases. Forecast soundings for the Kirksville area saturate around midnight or perhaps a little later. Have waited until then to increase PoPs into the likely range. Snow amounts in our northeastern zones are still expected to be in the 1" to as much as 3" range in Schuyler County. After coordination with neighbors, have issued a winter weather advisory for our extreme northeastern counties, including the Kirksville area. The other aspect of this wintry episode is the potential for freezing drizzle in the southern half of the forecast area. Confidence in this is quite a bit lower than with the snowfall in the northeast. First, the lowest several thousand feet never really saturate. Second, by the time saturation begins to lower, the warm front lifts through, warms the surface above freezing and desaturates the sounding aloft. So there really only looks like a marginal potential for several hours when lift is maximized coincident with the greatest amount of saturation. This seems to be around the 12Z time frame +/- an hour or two. However, freezing drizzle can have a major impact on travel as it can be deceptive in it`s ability to slicken roads. So it`ll be important for people who have to travel Sunday morning to understand that roads may be slick. But for now, confidence just isn`t high enough to issue an advisory at this time. Another clipper system will move through Monday night/ Tuesday morning. Forecast soundings show the lowest several thousand feet to be above freezing, even all the way into the northeastern portions of the forecast area. So for snow, the wave should have little impact with regards to wintry weather in the forecast area and we should see just rain or perhaps a rain/snow mix in our northern zones. The rest of the forecast looks quiet regarding precipitation. An upper level ridge will spread east with low level flow out of the south. This will help temperatures soar to well above normal levels by Thursday into Friday. Highs may be in the 70s in parts of the forecast area Thursday and potentially into Friday. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1118 AM CST SAT FEB 13 2016 VFR conditions with ceilings between 5 and 8 thousand feet are expected through the rest of the afternoon and into the overnight. Late tonight, ceilings are expected to lower to MVFR and possibly into the 1500 to 2000 ft range. There is also a chance for light freezing drizzle across eastern Kansas and western Missouri late tonight and early tomorrow morning. The most likely timing for this seems to be centered around 12Z give or take a few hours. Temperatures are expected to warm above freezing late Sunday morning with lower levels drying out, ending the potential for freezing drizzle. && .EAX Watches/Warnings/Advisories... KS...NONE. MO...Winter Weather Advisory from 9 PM this evening to 6 PM CST Sunday for MOZ008-017-025-033. && $$ DISCUSSION...CDB AVIATION...CDB
Area Forecast Discussion National Weather Service SPRINGFIELD MO 244 PM CST SAT FEB 13 2016 ...A Light Wintry Mix Late Tonight into Early on Sunday...Much Warmer Weather Returns Next Week... .SHORT TERM...(This Evening through Sunday) Issued at 0217 PM CST SAT FEB 13 2016 Cold and dry air has invaded much of the Missouri Ozarks region this afternoon. There are some areas across central Missouri that has barely reached 20 degrees. The main story for tonight into early tomorrow will be the threat of a light wintry mix and freezing drizzle. The latest Hi-Res forecast models all indicate very light precip to begin to develop between midnight and 3 am across western and southern Missouri. The latest RUC and HRRR even shows some convective like precip which indicates pockets of sleet possible. The overall message for late tonight into tomorrow morning is we are expecting only very light amounts of a light wintry mix but could be impacts on roads and travel in the morning. Ground and road temperatures have had time to cool down over the past 24 hours. The freezing line will settle somewhere near the Missouri and Kansas border tonight before it begins to retreat eastward during the morning hours. There will be very light precip falling across the Missouri Ozarks with the better potential for higher amounts across the eastern Ozarks. Freezing drizzle and some light sleet is expected across the western half of the area and a wintry mix with some light snow is expected across the eastern half of the area early on. This will slowly transition to just a cold light rain or drizzle late tomorrow morning into the early afternoon from west to east. We will issue a winter weather advisory for light amounts and possible travel impacts in the morning. Like what we saw a few weeks ago...it does not take much freezing drizzle to cause big travel problems in the Ozarks region. All areas in the advisory area can expect a very light glaze of ice possible. A dusting of light sleet or light snow can be expected east of Highway 65 with up to an inch of snow possible from the Highway 63 corridor and eastward. Most area will warm up above freezing by Sunday afternoon with some areas out across far western Missouri near 50. .LONG TERM...(Sunday Night through Saturday) Issued at 0217 PM CST SAT FEB 13 2016 There may be some fog developing late Sunday night into Monday morning. This will need to be watched because temperatures again may be around or slightly below freezing. The best potential for fog will be along and south of the I-44 corridor across southern Missouri. Milder temperatures return on Monday. A quick moving upper level system across the Midwest on Tuesday may bring a few more clouds and a slight chance of showers across central Missouri and the eastern Ozarks. Decent upper Level ridging will develop across the central U.S. for the middle and end of next week. This will allow for way above average temperatures for the region. Highs will be in the 60s and possible lower 70s. A preview of Spring is coming next week. && .AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon) Issued at 1156 AM CST SAT FEB 13 2016 An upper level disturbance will slide southeast across the region from late tonight into Sunday. This system will bring a variety of aviation impacts. Ceilings will lower starting late tonight with MVFR expected during the predawn hours. We are also expecting a light wintry mix of precipitation to develop late tonight, however precipitation onset time remains in question due to a very dry airmass which is currently in place. We have therefore handled this uncertainty with TEMPO groups. Low level wind shear conditions are also expected from late tonight into early Sunday morning. By sunrise, precipitation should be ongoing over most areas with freezing drizzle being the main precipitation type. Precipitation will begin to diminish around Joplin and then Springfield by late morning with temperatures warming to around the freezing mark by midday. Ceilings will remain in the MVFR category. && .SGF Watches/Warnings/Advisories... MO...Winter Weather Advisory from 3 AM to noon CST Sunday for MOZ055>058-066>071-077>083-088>098-101>106. KS...NONE. && $$ SHORT TERM...Griffin LONG TERM...Griffin AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
828 PM CST SUN FEB 14 2016 .UPDATE... ISSUED AT 825 PM CST SUN FEB 14 2016 RADAR INDICATES SOME LIGHT TO MODERATE SNOW SHOWERS CROSSING SOUTHWEST NEBRASKA AND SATELLITE CLOUD TEMPERATURES OF -41C INDICATE THAT THERE IS SOME VERTICAL EXTENT...THUS WE HAVE UPDATED TO INCLUDE A LITTLE MORE THAN SPRINKLES/FLURRIES. STILL...BECAUSE THE SHOWERS ARE MOVING QUICKLY...ACCUMULATIONS WILL BE MINIMAL. UPDATE ISSUED AT 747 PM CST SUN FEB 14 2016 TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON. THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS 850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/ FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS. MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING. ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S. COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE IS RAIN. THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE 80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER. THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS. THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE OVERHEAD IN THE AFTERNOON. WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST- SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT. A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE TEMPERATURE FORECAST. A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR THIS POTENTIAL WIND EVENT. LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60. DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO SUPPORT DEEP VERTICAL MIXING. ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT. SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE ROCKIES DOMINATES THE COLDER ARCTIC AIR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 510 PM CST SUN FEB 14 2016 WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260- 300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING MONDAY TO EARLY AFTERNOON. THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS IN THE TERMINAL FORECASTS FOR LBF OR VTN. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SPRINGER SHORT TERM...SNIVELY LONG TERM...CDC AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
749 PM CST SUN FEB 14 2016 .UPDATE... ISSUED AT 747 PM CST SUN FEB 14 2016 TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON. THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS 850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/ FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS. MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING. ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S. COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE IS RAIN. THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE 80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER. THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS. THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE OVERHEAD IN THE AFTERNOON. WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST- SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT. A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE TEMPERATURE FORECAST. A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR THIS POTENTIAL WIND EVENT. LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60. DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO SUPPORT DEEP VERTICAL MIXING. ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT. SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE ROCKIES DOMINATES THE COLDER ARCTIC AIR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 510 PM CST SUN FEB 14 2016 WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260- 300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING MONDAY TO EARLY AFTERNOON. THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS IN THE TERMINAL FORECASTS FOR LBF OR VTN. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SPRINGER SHORT TERM...SNIVELY LONG TERM...CDC AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
511 PM CST SUN FEB 14 2016 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON. THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS 850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/ FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS. MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING. ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S. COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE IS RAIN. THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE 80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER. THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS. THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE OVERHEAD IN THE AFTERNOON. WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST- SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT. A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE TEMPERATURE FORECAST. A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR THIS POTENTIAL WIND EVENT. LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60. DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO SUPPORT DEEP VERTICAL MIXING. ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT. SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE ROCKIES DOMINATES THE COLDER ARCTIC AIR. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 510 PM CST SUN FEB 14 2016 WIND TONIGHT IN CENTRAL AND WESTERN NEBRASKA IS EXPECTED TO BE 260- 300 AT LESS THAN 10KT...THEN PICKING UP TO 10-14KT LATE MORNING MONDAY TO EARLY AFTERNOON. THERE ARE SIGNIFICANT DIFFERENCES AMONG THE SHORT TERM OUTPUT REGARDING THE LIKELIHOOD OF INSTRUMENT METEOROLOGICAL CONDITIONS. OF THE FOUR MAIN SOLUTIONS...ONLY ONE INDICATES INSTRUMENT CEILINGS WITH THE OTHERS INDICATING THAT CEILINGS...IF ANY WILL BE AT OR ABOVE 10000 FEET AGL. THERE IS A LITTLE STRONGER PROBABILITY OF INSTRUMENT CONDITIONS ALONG AND EAST OF AN ONL-BBW LINE. FOR THE TIME BEING...THEN...WE WILL NOT INDICATE ANY RESTRICTIVE CONDITIONS IN THE TERMINAL FORECASTS FOR LBF OR VTN. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SNIVELY LONG TERM...CDC AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
914 PM EST SUN FEB 14 2016 .SYNOPSIS... BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE AREA ON TUESDAY. && .NEAR TERM /UNTIL 8 AM MONDAY MORNING/... 910 PM UPDATE.. LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH SHOULD SLOW THE FALL OF TEMPERATURES. I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE VARIABILITY FROM SITE TO SITE. 4PM UPDATE... LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION. 850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN THE SINGLE DIGITS. && .SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... 915 PM UPDATE... ONE MINOR UPDATE: WE ADDED FLURRIES TO THE FORECAST FOR MUCH OF THE REGION, BEGINNING MID-MORNING. THE NAM AND GFS BOTH GENERATE LIGHT PRECIPITATION UNDER A FAST MOVING SHORT WAVE. WE ALSO MADE SMALL CHANGES TO THE MONDAY MORNING AND AFTERNOON QPF/SNOW FIELDS. 4 PM SUNDAY UPDATE... A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT. MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA- CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT. GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN ISSUED. WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS SITUATION CLOSELY, AND WILL CONTINUE TO DO SO. THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE NIGHT. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... 442 PM UPDATE... VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST. AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN, POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE MORNING. TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT PASSES LATE SATURDAY. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. WINDS THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE OVERNIGHT...THEN SE OR S 8-12 KTS MONDAY. .OUTLOOK... MON NGT-TUE...RESTRICTIONS IN SNOW OR WINTRY MIX MON NGT...BECOMING MAINLY RAIN TUE. TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO SNOW ON BACK END OF DEPARTING STORM. WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN. THU-EARLY FRI...VFR. LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY FOR PAZ038>040-043-044-047-048-072. NY...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY FOR NYZ023>025-036-037-044>046-055>057-062. WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR NYZ009-015>018-022. && $$ SYNOPSIS...MLJ NEAR TERM...DJP/KAH SHORT TERM...DJP/MLJ LONG TERM...DJP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
912 PM EST SUN FEB 14 2016 .SYNOPSIS... BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE AREA ON TUESDAY. && .NEAR TERM /UNTIL 8 AM MONDAY MORNING/... 910 PM UPDATE.. LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH SHOULD SLOW THE FALL OF TEMPERATURES. I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE VARIABILITY FROM SITE TO SITE. 4PM UPDATE... LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION. 850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN THE SINGLE DIGITS. && .SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... 4 PM SUNDAY UPDATE... A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT. MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA- CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT. GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN ISSUED. WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS SITUATION CLOSELY, AND WILL CONTINUE TO DO SO. THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE NIGHT. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... 442 PM UPDATE... VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST. AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN, POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE MORNING. TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT PASSES LATE SATURDAY. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. WINDS THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE OVERNIGHT...THEN SE OR S 8-12 KTS MONDAY. .OUTLOOK... MON NGT-TUE...RESTRICTIONS IN SNOW OR WINTRY MIX MON NGT...BECOMING MAINLY RAIN TUE. TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO SNOW ON BACK END OF DEPARTING STORM. WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN. THU-EARLY FRI...VFR. LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY FOR PAZ038>040-043-044-047-048-072. NY...WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 7 AM EST TUESDAY FOR NYZ023>025-036-037-044>046-055>057-062. WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING FOR NYZ009-015>018-022. && $$ SYNOPSIS...MLJ NEAR TERM...DJP/KAH SHORT TERM...MLJ LONG TERM...DJP AVIATION...MDP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1240 AM EST SAT FEB 13 2016 .SYNOPSIS...ARCTIC HIGH PRESSURE WILL BUILD INTO CENTRAL NC TODAY AND SUNDAY. AN AREA OF LOW PRESSURE WILL APPROACH FROM THE WEST ON MONDAY AND CROSS THE REGION MONDAY NIGHT AND TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 940 PM FRIDAY... STARTING TO FINALLY SEE BETTER WEST TO EAST CLEARING OF MOISTURE AROUND 6000-7000 FT AS A JET ON THE BACK SIDE OF THE UPPER TROUGH APPROACHES AND NORTHWEST FLOW STRENGTHENS. LOW-LEVEL MOISTURE IS STILL MORE PREVALENT ON THE COASTAL PLAIN WHERE SOME SUB-1000 FT STRATUS IS LINGERING. A PERIOD OF PATCHY FOG MAY DEVELOP IN THE SOUTHERN COASTAL PLAIN AS THE HIGHER LEVEL CLOUDS CLEARING (HINTED AT BY SREF PROBS AND KFAY/KGSB RAP SOUNDINGS)...BUT IT WOULD LIKELY BE BRIEF...PRIOR TO 06Z...WITH A NORTHWEST WIND AND COLD ADVECTION FORECAST TO SLOWLY STRENGTHEN AFTER MIDNIGHT. OTHERWISE...WHILE WE MAY SEE A SOME PATCHES OF STRATOCU DRIFT ACROSS THE AREA GIVEN ALL THE MOISTURE BANKED UPSTREAM OF THE MOUNTAINS...CLEARING SKIES AND COLD ADVECTION WILL PUSH LOWS INTO THE LOWER 20S NORTH AND WEST TO UPPER 20S SOUTH AND EAST. && .SHORT TERM /SATURDAY AND SATURDAY NIGHT/... AS OF 300 PM FRIDAY... AS EAST COAST TROUGH TRIES TO PULL OFF THE COAST...VERY STRONG COLD AIR ADVECTION WILL ENSUE BEHIND THE EXITING COASTAL SYSTEM. WITH VERY STRONG PRESSURE GRADIENT ACROSS THE AREA...COLD TEMPERATURES AND STRONG WINDS WILL BE THE FORECAST PROBLEM OF THE DAY. EXPECT WINDS TO REMAIN SUSTAINED OUT OF THE NORTH OR NORTHWEST AT 10-15 KTS WITH GUSTS OF 25-30 KTS FOR MUCH OF THE DAYLIGHT HOURS. AFTER SUNSET GUSTS WILL SUBSIDE. HIGH TEMPERATURES ONLY IN THE LOW TO MID 30S AND WITH WIND CHILL VALUES IN THE UPPER 10S TO LOW 20S FOR MUCH OF THE DAY. AS AN ASIDE...WITH THE COLD BUT ALSO DRY AIRMASS IN PLACE...MIN RH VALUES WILL DIP DOWN INTO THE LOW 20S. COMBINE THESE VALUES WITH THE HIGHER WINDS AND THERE WILL BE A SMALL INCREASE IN FIRE DANGER SATURDAY IN OUR SOUTHERN COUNTIES THAT MAY SQUEAK INTO THE LOWER 40S. SATURDAY NIGHT WILL SEE THE GUSTS SLACK OFF BUT SUSTAINED WINDS TO REMAIN UP IN THE 5 TO 10 KT RANGE KEEP THINGS MIXED A LITTLE. COMBINE THIS WITH VERY COLD EXPECTED LOW TEMPERATURES IN THE LOW TO MID TEENS...WIND CHILL VALUES SATURDAY NIGHT WILL RESIDE IN THE 5-10 DEGREE RANGE. PREPARATIONS SHOULD BE MADE NOW TO PROTECT ANYTHING SUSCEPTIBLE TO THE COLD WIND CHILLS...ESPECIALLY PETS. SOME CLOUDS WILL BEGIN TO APPROACH THE AREA LATE SATURDAY NIGHT INTO SUNDAY MORNING FROM THE WEST IN ADVANCE OF THE NEXT STORM SYSTEM. && .LONG TERM /SUNDAY THROUGH FRIDAY/... AS OF 315 PM FRIDAY... ...STORM SYSTEM LIKELY TO BRING WINTRY WEATHER THREAT SUN NIGHT/MON FOLLOWED BY HEAVY RAIN THREAT AND A FEW STORMS MON NIGHT/TUE... SUNDAY: CONTINUED CHILLY WITH THE ARCTIC HIGH PRESSURE EXTENDING FROM THE ERN GREAT LAKES DOWN THROUGH NC. WILL HAVE INCREASING CLOUDS AHEAD OF THE APPROACHING STORM... AS OUR MID LEVEL FLOW SHIFTS FROM FAST NORTHWESTERLY TO WEST-SOUTHWEST... A FUNCTION OF PACIFIC NORTHWEST ENERGY DIVING INTO AN INITIALLY FLAT/BROAD CENTRAL CONUS TROUGH CAUSING ITS AMPLIFICATION. STATISTICAL GUIDANCE STILL SUPPORTS HIGHS FROM 29 NE TO 35 SW. -GIH SUN NIGHT THROUGH TUE: OVERVIEW: CONFIDENCE IS BEGINNING TO INCREASE REGARDING THE TIMING... MOST PROBABLE PRECIP TYPE PATTERN... AND PRIMARY WEATHER THREATS FOR THE INCOMING SYSTEM. LATEST GUIDANCE SHOWS A BIT QUICKER ONSET... WITH PRECIP ARRIVING IN THE NRN/WRN CWA SUN NIGHT... AS WELL AS A SLIGHTLY EARLIER DEPARTURE ON TUE. LONGWAVE TROUGHING WILL CONTINUE TO AMPLIFY ALONG THE MISS VALLEY AS NRN STREAM ENERGY DROPS INTO ITS BASE OVER THE GULF STATES... CULMINATING IN A NARROW DEEP SHORTWAVE TROUGH TAKING ON A POSITIVE TILT AS IT SWINGS ENE INTO THE CAROLINAS. AT THE SURFACE... THE POLAR HIGH SITUATED OVER THE NORTHEAST AND MIDATLANTIC STATES SUN NIGHT CONTINUES TO PUSH STEADILY NORTHEAST AND OFFSHORE THROUGH MON... WHILE A COASTAL FRONT FORMS ALONG THE CAROLINA COAST EXTENDING BACK TO DEVELOPING LOW PRESSURE OVER THE CENTRAL GULF STATES. THIS LOW THEN TRACKS EAST THEN NE THROUGH WRN NC MON NIGHT/TUE MORNING BEFORE MOVING QUICKLY INTO THE NORTHEAST STATES... WITH A TRAILING FRONT SWEEPING THROUGH CENTRAL/ERN NC BY EARLY TUE AFTERNOON. PRECIPITATION CHANCES: THE INITIAL PROCESSES TO FORCE ASCENT SUNDAY NIGHT INTO EARLY MONDAY INCLUDING DPVA AND MOIST ISENTROPIC UPGLIDE ARE RATHER WEAK AND FOCUSED PRIMARILY ON WRN AND NRN PORTIONS OF CENTRAL NC. WILL TREND POPS UP TO LIKELY NW AND RETAIN HIGH CHANCES ACROSS THE SOUTH AND EAST SUN NIGHT INTO MON MORNING... WITH QPF FAIRLY LIGHT... UNDER A QUARTER INCH MAINLY IN THE NW. BUT THIS CHANGES QUICKLY WITH THE ADDITION OF STRONG UPPER DIVERGENCE (DUE TO IDEALLY JUXTAPOSED POLAR AND SUBTROPICAL JETS) AND VIGOROUS LOW LEVEL MOISTURE TRANSPORT EAST OF THE LOW. WILL RAMP UP POPS FURTHER TO CATEGORICAL WEST/LIKELY EAST LATE MON... THEN TO CATEGORICAL EVERYWHERE MON NIGHT THROUGH TUE MORNING... ENDING SW TO NE TUE AFTERNOON. PTYPES: USING THE TOP-DOWN METHODOLOGY WITH CONSIDERATION OF THE INITIALLY VERY COLD/DENSE NATURE OF THE SURFACE AIR MASS... THE INITIAL COLD AIR ALOFT GIVING WAY TO A WARM NOSE... AND THE STRONG LOW LEVEL WARM ADVECTION APT TO DISLODGE THIS SURFACE AIR MASS GRADUALLY FROM SE TO NW MON EVENING... EXPECT THIS TO START AS MOSTLY LIGHT SNOW WITH PERHAPS PATCHY LIGHT SLEET SUN NIGHT ACROSS THE NRN AND WRN CWA... FOLLOWED BY A SLOW STEADY TRANSITION FROM SSE TO NNW TO FREEZING RAIN/SLEET THEN TO ALL RAIN... WITH THE FAR NW COUNTIES INCLUDING THE TRIAD THE LAST TO SEE AN END TO THE WINTRY PRECIP MON EVENING. TENTATIVE ACCUMULATIONS ARE UP TO ONE TO TWO HUNDREDTHS OF AN INCH OF ICING (TRACE AMOUNTS) FOR MUCH OF THE CWA... AND SNOW TOTALS OF 1-3" NW QUARTER WITH AN INCH OR LESS ELSEWHERE... ALL OF WHICH SHOULD BE QUICKLY SWEPT AWAY BY MODERATE TO POTENTIALLY HEAVY RAINFALL LATE MON NIGHT INTO TUE MORNING. RAINFALL TOTALS AND STORM POTENTIAL: AT THIS TIME STORM TOTAL LIQUID QPF IS EXPECTED TO BE 1-2" WITH LOCALLY HIGHER AMOUNTS POSSIBLE... GIVEN THE HIGH WATER CONTENT AND STRONG LIFT MON NIGHT/TUE MORNING. BASED ON THE ANTECEDENT CONDITIONS AND SEVERAL RIVERS AND CREEKS RUNNING HIGH... A FLOOD WATCH MAY BE NEEDED FOR SOME PORTION OF THE AREA. ALSO... WHILE LAPSE RATES ARE UNLIKELY TO BE VERY IMPRESSIVE... THE STRONG AND FOCUSED LIFT POSSIBLE WITH THIS SYSTEM AND WARMING LOW LEVELS ESPECIALLY IN THE SANDHILLS AND COASTAL PLAIN MAY SUPPORT A FEW LIGHTNING STRIKES ON TUE. TEMPS: EXPECT LOWS SUN NIGHT OF 22-26. TEMPS SHOULD SLOWLY RISE MON THROUGH MON NIGHT... REACHING THE LOW 30S NW TO LOW 40S SE LATE MON... RISING TO THE MID 30S NW TO MID 40S SE MON NIGHT... AND PEAKING AT 48-56 TUE PRIOR TO FRONTAL PASSAGE. WED THROUGH FRI: WE MAY SEE A PERTURBATION SWING THROUGH THE LONGWAVE ERN TROUGH BASE ACROSS VA ON WED... BUT MODELS VARY ON THE STRENGTH AND LATITUDE OF ANY SUCH WAVE... AND REGARDLESS THE MOISTURE WILL BE LIMITED YIELDING NO IMPACTS ON CENTRAL NC OTHER THAN SOME CLOUDS ACROSS THE NORTH. OTHERWISE... THIS PERIOD WILL FEATURE A TRANSITION AWAY FROM WRN RIDGE/ERN TROUGH OVER THE CONUS... AS FLAT RIDGING BUILDS OVER THE GULF/SOUTHEAST STATES FROM THE WEST... WITH A NET RESULT OF DRY WEATHER AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPS FOR CENTRAL NC. -GIH && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... AS OF 1240 AM SATURDAY A LAYER OF SCATTERED-BROKEN STRATOCU WILL LINGER ACROSS THE NORTHERN COUNTIES THROUGH 10Z...THEN GRADUALLY DIMINISH. THE LEADING EDGE OF AN ARCTIC AIRMASS WILL OVERSPREAD CENTRAL NC THROUGH 11Z. SFC WINDS WILL GUSTS BETWEEN 20-25KTS WITH THE PASSAGE OF THE BOUNDARY. AFTER 11Z...EXPECT VFR CONDITIONS WITH FEW-SCATTERED STRATOCU. SFC WINDS WILL BE BRISK WITH GUSTS 22-27KTS HIGHLY PROBABLE FROM THE NW. THESE BRISK WINDS WILL SLOWLY SUBSIDE LATER TONIGHT. VFR CONDITIONS TO CONTINUE INTO SUNDAY THOUGH MID-HIGH LEVEL CLOUDS WILL BE INCREASING DURING THE DAY AS AN AREA OF LOW PRESSURE APPROACHES FROM THE WEST. MOISTURE AHEAD OF THIS SYSTEM WILL LEAD TO SUB VFR CEILINGS ALONG WITH PATCHES OF PRECIPITATION LATE SUNDAY NIGHT INTO MONDAY MORNING. AT ONSET...THIS PRECIPITATION MAY OCCUR AS A WINTRY MIX. THE SUB VFR CONDITIONS MAY LINGER INTO EARLY TUESDAY WITH IMPROVING CONDITIONS LATE TUESDAY INTO WEDNESDAY. && .CLIMATE... HERE ARE THE RECORD LOWS AND RECORD LOW MAXIMUM TEMPERATURES FOR SAT FEB 13TH AND SUN FEB 14TH AT GSO... RDU... AND FAY: REC YR REC YR LOW LOW MAX ---------------------------------------------- GSO: 02/13 11 1955 31 1986 02/14 6 1905 22 1914 RDU: 02/13 4 1899 10 1899 02/14 -2 1899 27 1916 FAY: 02/13 14 1973 32 1955 02/14 12 1968 33 1916 && .RAH WATCHES/WARNINGS/ADVISORIES... NONE && $$ SYNOPSIS...WSS NEAR TERM...SMITH SHORT TERM...ELLIS LONG TERM...HARTFIELD AVIATION...WSS CLIMATE...RAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
916 PM CST SUN FEB 14 2016 .UPDATE... ISSUED AT 903 PM CST SUN FEB 14 2016 NORTH DAKOTA DOT WEBCAMS SHOWING SCATTERED AREAS OF FOG FORMING AT ASHLEY...DUNSEITH...KULM AND PETTIBONE. ALSO SEEING FOG AT JAMESTOWN AND HARVEY AIRPORTS. ALTHOUGH THERE WILL BE SOME VARIABILITY IN VISIBILITY AS IS TYPICAL...READY TO GO WITH AREAS OF FOG JAMES RIVER VALLEY NORTH THROUGH RUGBY AND DUNSEITH AND PATCHY FOG TO THE WEST INTO THE MISSOURI AND PORTIONS OF THE SOURIS RIVER VALLEYS. WILL MONITOR FOR ANY DENSE FOG ADVISORIES NEEDED BUT NOT AT THIS TIME. UPDATE ISSUED AT 557 PM CST SUN FEB 14 2016 MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE AMOUNT OF MID/HIGH CLOUDS REMAIN. THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA. CURRENT FORECAST TRACKING WELL SO FAR. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON. FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC. FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK /LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL ONLY LOWER THROUGH THE REST OF THE DAY. TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000 FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19 UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD. ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON. WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH 850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF 0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD. MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE HWO WITH THIS FORECAST ISSUANCE. THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH THIS S/WV. BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE. UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY. MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH KEEPING AN EYE ON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 903 PM CST SUN FEB 14 2016 FOG FORMING IN THE JAMES RIVER VALLEY. EXPECT SOME VARIABILITY BUT WILL GO VERY LOW IFR WITH 1/2SM FZFG AT KJMS THROUGH THE NIGHT. WILL CONTINUE TO EVALUATE TRENDS BUT BELIEVE THIS WILL BE A FOGGY NIGHT. ELSEWHERE...EXPECT KBIS-KMOT MORE IN THE EDGE OF THE FOG WITH 3 MILES BR. VFR KISN-KDIK UNTIL MONDAY AFTERNOON AS NEXT SYSTEM MOVES WITH WITH MVFR CEILINGS AND CHANCE RAIN/SNOW. SINCE THIS IS LATE IN THE FORECAST PERIOD USED VCSH. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...CJS LONG TERM...NH AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
610 PM CST SUN FEB 14 2016 .UPDATE... ISSUED AT 557 PM CST SUN FEB 14 2016 MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE AMOUNT OF MID/HIGH CLOUDS REMAIN. THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA. CURRENT FORECAST TRACKING WELL SO FAR. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON. FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC. FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK /LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL ONLY LOWER THROUGH THE REST OF THE DAY. TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000 FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19 UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD. ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON. WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH 850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF 0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD. MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE HWO WITH THIS FORECAST ISSUANCE. THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH THIS S/WV. BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE. UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY. MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH KEEPING AN EYE ON. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING) ISSUED AT 557 PM CST SUN FEB 14 2016 EARLY SUNDAY EVENING A WARM FRONT EXTENDED FROM LOW PRESSURE IN MANITOBA INTO EASTERN NORTH DAKOTA. MVFR STRATUS ASSOCIATED WITH THE FRONT WAS PROGRESSING EAST AND IS EXPECTED TO CLEAR OUT OF KJMS AFTER 02Z. OTHERWISE ABUNDANT SURFACE MOISTURE FROM MELTING SNOW AND CLEARING SKIES WILL FAVOR AREAS OF FOG KBIS-KMOT-KJMS AFTER 03Z. HRRR SHORT RANGE MODEL DEPICTS LIFR VSBYS AFTER 03Z. CURRENTLY HAVE 3SM BR FOR THE VSBY FORECAST BUT SOME UNCERTAINTY AS TO HOW DENSE THE FOG BECOMES. COULD BE IFR VSBYS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...CJS LONG TERM...NH AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1230 PM CST SAT FEB 13 2016 .UPDATE... ISSUED AT 1215 PM CST SAT FEB 13 2016 ADDED A FREEZING RAIN ADVISORY FOR WILLIAMS AND DIVIDE COUNTY THROUGH 00Z TONIGHT AND EXPANDED THE WINTER WEATHER ADVISORY INTO BURKE...MOUNTRAIL...AND RENVILLE COUNTIES WITH THIS UPDATE. LATEST OBSERVATIONS OUT OF NORTHEASTERN MONTANA AND FORECAST SOUNDINGS NEAR WILLISTON SUPPORT A PERIOD OF FREEZING RAIN AND SNOW MIX IN THE NORTHWEST THROUGH LATE AFTERNOON. BY EVENING...PRECIPITATION SHOULD TRANSITION TO ALL SNOW. THE FORECAST APPEARS ON TRACK FOR THE REST OF THE AREA. UPDATE ISSUED AT 947 AM CST SAT FEB 13 2016 NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN WYOMING. UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016 EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS UPDATE. THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE 08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST SAT FEB 13 2016 THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5 BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR RISING...WITH TEENS IN THE FAR WEST ALL NIGHT. WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING. A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE. THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3 TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN SOUTHWESTERN NORTH DAKOTA. IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL - ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW AMOUNTS. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 346 AM CST SAT FEB 13 2016 ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1215 PM CST SAT FEB 13 2016 FAST MOVING LOW PRESSURE WAS DEVELOPING OVER SOUTHEASTERN MONTANA. THIS SYSTEM WILL BRING FROZEN PRECIPITATION TO MUCH OF THE WESTERN AND CENTRAL PARTS OF NORTH DAKOTA THROUGH THE AFTERNOON AND OVERNIGHT HOURS. PRECIPITATION WILL BEGIN AS A MIX OF RAIN...FREEZING...AND SNOW IN THE WEST THIS AFTERNOON...EVENTUALLY TRANSISTIONING TO ALL SNOW BY TONIGHT. MFVR CEILINGS AND VISIBILITES WILL BE COMMON ACROSS ALL SITES...WITH PERIODS OF IFR/LIFR CONDITIONS POSSIBLE WITHIN ANY HEAVIER SNOW BANDS. WINDS OF 15-20 KNOTS WILL GENERALLY COME FROM THE SOUTH THIS AFTERNOON...TRANSITIONING WEST/NORTHWESTERLY BY THE OVERNIGHT HOURS. PRECIPITATION WILL BEGIN TO DIMINISH EARLY SUNDAY MORNING. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR NDZ002>005-010>013-019>023-025-034>037-042-045>048-050-051. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ017-018-031>033-040-041-043-044. FREEZING RAIN ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ001- 009. && $$ UPDATE...ZH SHORT TERM...JV LONG TERM...AYD AVIATION...ZH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
951 AM CST SAT FEB 13 2016 .UPDATE... ISSUED AT 947 AM CST SAT FEB 13 2016 NO SIGNIFICANT CHANGES WERE NEEDED FOR THIS UPDATE. DID INCREASE PRECIPITATION CHANCES OVER THE WEST AND CENTRAL THROUGH 18Z...AS MULTIPLE OBSERVATIONS ARE COMING IN WITH LIGHT SNOW WHERE THERE HAVE BEEN LITTLE TO NO RADAR RETURNS. THINKING REMAINS THE SAME ON WINTER WEATHER HEADLINES AS WE ENTER A HOLDING PATTERN...WITH LOW PRESSURE NOW DEVELOPING OVER SOUTHERN SASKATCHEWAN AND NORTHERN WYOMING. UPDATE ISSUED AT 701 AM CST SAT FEB 13 2016 EXPANDED THE WINTER WEATHER ADVISORY INTO THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA FOR THIS AFTERNOON THROUGH TONIGHT WITH THIS UPDATE. THE FULL 00 AND 06 UTC DETERMINISTIC AND ENSEMBLE SUITES AND THE 08-11 UTC HRRR AND RAP ITERATIONS ALL SUPPORT THE POTENTIAL FOR MODERATE SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND TURTLE MOUNTAINS AREA THIS AFTERNOON THROUGH TONIGHT. OVERALL...A CONSENSUS OF THESE SOLUTIONS SUPPORTS GREATER QPF THAN THE PREVIOUS FORECAST OVER MOST OF THE CWA THIS AFTERNOON THROUGH TONIGHT...LEADING TO GREATER SNOWFALL TOTALS. OBSERVED TRENDS ACROSS MONTANA THIS MORNING AND THE 12 UTC SUITE WILL HAVE TO BE CLOSELY EVALUATED AS SOME LOCATIONS ACROSS CENTRAL NORTH DAKOTA HAVE THE POTENTIAL TO APPROACH WARNING LEVEL SNOWFALL AS DEPICTED IN 00 AND 06 UTC SUITES. HEAVY SNOWFALL RATES ARE POSSIBLE GIVEN STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH THE POTENT SHORTWAVE. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 346 AM CST SAT FEB 13 2016 THE FOCUS OF THE SHORT TERM FORECAST IS A WINTRY MIX IN WESTERN ND AND SNOWFALL IN CENTRAL ND. A FREEZING RAIN ADVISORY WILL BE ISSUED FOR SOUTHWESTERN NORTH DAKOTA...AND A WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. CURRENTLY...ARCTIC HIGH PRESSURE EXTENDED FROM MANITOBA TO IOWA...WITH LOW PRESSURE ALONG THE LEE OF THE ROCKIES. TEMPERATURES HAVE BEEN RISING ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY THIS MORNING. LOWS RANGED FROM 5 TO 20 BELOW ZERO FROM THE TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY...BUT WERE CURRENTLY AROUND 5 BELOW ZERO. FARTHER WEST TEMPERATURES HAVE BEEN FAIRLY STEADY OR RISING...WITH TEENS IN THE FAR WEST ALL NIGHT. WARM ADVECTION FROM THE WEST...ACCOMPANIED BY ISENTROPIC LIFT...WAS ASSOCIATED WITH A BAND OF LIGHT SNOW THAT EXTENDED FROM WILLISTON AND STANLEY IN THE NORTHWEST TO GRANT AND SIOUX COUNTIES IN THE SOUTH CENTRAL PART OF THE STATE. THE LATEST ITERATIONS OF THE HIGHRES MODELS INDICATE THIS BAND OF LIGHT SNOW WEAKENING/DISSIPATING AS IT PROGRESSES EASTWARD THIS MORNING. A SIGNIFICANT UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE EAST ACROSS IDAHO AND MONTANA THIS MORNING...THEN MOVE SOUTHEAST ACROSS THE DAKOTAS THIS AFTERNOON AND TONIGHT. PRECIPITATION IS EXPECTED TO DEVELOP BEFORE NOON IN THE SOUTHWEST AND AROUND NOON IN CENTRAL NORTH DAKOTA ASSOCIATED WITH THIS SHORTWAVE. THE 00Z AND 06Z HIGHRES MODELS SUGGEST STRONG WARM ADVECTION CONTINUING IN THE SOUTHWEST...WITH MAX TEMPERATURES ALOFT AROUND +3 TO +5 C. THUS THE THERMAL PROFILES SUGGEST A MIX OF LIGHT FREEZING RAIN...SLEET...SNOW...OR RAIN AT TIMES THIS AFTERNOON. AS THE SHORTWAVE PASSES THROUGH...COLD ADVECTION WILL ENSUE AND PRECIPITATION WILL LIKELY CHANGE TO LIGHT SNOW THIS EVENING IN SOUTHWESTERN NORTH DAKOTA. IN SOUTH CENTRAL NORTH DAKOTA...THE THERMAL PROFILES SUGGEST MAINLY SNOW...BUT A MIX OF SLEET OR FREEZING RAIN IS POSSIBLE AS WELL - ESPECIALLY DURING THE AFTERNOON. MODELS ARE NOT IN THE BEST AGREEMENT REGARDING SNOW AMOUNTS...BUT CONSENSUS SNOW AMOUNTS ARE IN THE 3-5 INCH RANGE BY DAYBREAK SUNDAY MORNING. THUS CONFIDENT ON AT LEAST WINTER WEATHER ADVISORY FOR THE SOUTH CENTRAL. SOME OF THE LATEST ITERATIONS OF THE SHORT TERM MODELS ARE HINTING AT HIGHER SNOW AMOUNTS...BUT CONFIDENCE IS LOWER - MAINLY BECAUSE IF THERMAL PROFILES ARE WARMER/COOLER THAN FORECAST THIS WILL IMPACT SNOW AMOUNTS. .LONG TERM...(SUNDAY THROUGH FRIDAY) ISSUED AT 346 AM CST SAT FEB 13 2016 ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC AND INCOMING 06 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN GOOD AGREEMENT ON A BROAD...LOW AMPLITUDE UPPER LEVEL RIDGE BUILDING ACROSS THE CENTRAL CONUS THROUGHOUT THE EXTENDED FORECAST PERIOD. THUS...ABOVE NORMAL HIGH TEMPERATURES IN THE 30S AND 40S ARE EXPECTED OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THROUGHOUT THE PERIOD. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 701 AM CST SAT FEB 13 2016 A BAND OF LIGHT SNOW WAS OVER NORTHWEST AND CENTRAL NORTH DAKOTA EARLY THIS MORNING WITH CEILINGS AND VSBYS LOWERING TO MVFR. EXPECT MVFR CEILINGS TO REMAIN AT CENTRAL ND SITES ONCE THEY ARRIVE. BUT PERHAPS A PERIOD OF LOW VFR CEILINGS AT KISN AND KDIK 12-18Z BEFORE LOWERING BACK TO MVFR AFT 18Z SAT. MAIN CONCERN IS LATER ON SATURDAY 15Z- 23Z IN WESTERN ND WHEN WARM ADVECTION FROM THE WEST WOULD BRING A WINTRY MIX STARTING WITH SNOW...LEADING TO SLEET...THEN FREEZING RAIN...BEFORE CHANGING BACK TO SNOW AFT 00Z. WILL BE ANALYZING LATEST MODELS AND HOPE TO HAVE A HIGHER CONFIDENCE LEVEL FOR THE 12Z TAF ISSUANCE FOR TIMING AT KISN AND KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR NDZ004-005-011>013-019>023-025-034>037-042-045>048-050-051. FREEZING RAIN ADVISORY UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ017-018-031>033-040-041-043-044. && $$ UPDATE...ZH SHORT TERM...JV LONG TERM...AYD AVIATION...AYD
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
853 PM EST SUN FEB 14 2016 .SYNOPSIS... COMPLEX SYSTEM GIVES MESSY CONCOCTION OF WINTRY WEATHER THEN WATER CONCERNS. THE SYSTEM EXITS EARLY TUESDAY...FOLLOWED BY ANOTHER SYSTEM TUESDAY NIGHT. && .NEAR TERM /THROUGH MONDAY/... 900 PM UPDATE...EXTENDED WINTER STORM WARNINGS A ROW OR TWO COUNTIES TO THE NORTH OF THE PREVIOUS WARNING IN THE TRISTATE AREA DUE TO RADAR IMAGERY INDICATING A HEAVY BAND OF SNOW ORIENTED ALONG THE I-64 CORRIDOR. ALSO...THE HI-REZ MESOSCALE MODELS LIKE THE HRRR AND NCAR ENSEMBLES INDICATED QUITE A BIT MORE QPF THAN THE DETERMINISTIC NATIONAL SUITE. ALSO EXTENDED ADVISORIES TO THE NORTHERN TIER OF THE CWA...MAINLY TO HIGHLIGHT THE SNOW TONIGHT AND POTENTIAL FOR FREEZING RAIN TOMORROW. SNOW TO SLEET TO FREEZING RAIN OR JUST RAIN CHANGEOVER STILL LOOKS ON TRACK FOR TOMORROW MORNING IN AND AROUND THE 6 AM TO NOON TIMEFRAME DEPENDING ON LOCATION. SOME LOCATIONS IN THE MOUNTAINS LIKE POCAHONTAS COUNTY COULD SEE SIGNIFICANT ICE ACCUMULATIONS OF OVER A 1/4 TO 1/2 AN INCH...SO BE AWARE OF THAT. PREVIOUS DISCUSSION FOLLOWS... FLAKES SHOULD BE REACHING GROUND ON SCHEDULE IN THE TRI STATE AROUND HTS ON SE TO SOUTHWEST VIRGINIA...NOW THROUGH DARK. MAIN CHANGE WAS JUST TO ADD BOONE AND FAYETTE TO THE SOUTHERN WARNING. ALSO WILL ADD JUST A FEW COUNTIES WITH THE LOWER SNOW CRITERIA TO AN ADVISORY...INCLUDING ATHENS...WOOD...WIRT AND CALHOUN. AS SNOW CHANGES TO RAIN...ADDED SOME POCKETS OF FREEZING RAIN MONDAY IN NORTH CENTRAL WEST VIRGINIA DUE TO THE COLD GROUND. MAY EVEN BE SOME FREEZING AT 33 OR 34 DEGREES. NO REASON FOR AN ADVISORY AT THIS DISTANCE IN TIME. TEMPERATURES SHOULD HOLD STEADY OR SLOWLY RISE OVERNIGHT AND MONDAY. THE INCREASING SOUTHEAST FLOW STILL HAS US CONCERNED ABOUT THE FREEZING RAIN FROM THE BECKLEY/OAK HILL VICINITY ON NORTHEAST TO SNOWSHOE AND THE GREENBRIER VALLEY IN POCAHONTAS COUNTY MONDAY AFTERNOON...THEN CONTINUING IN POCAHONTAS COUNTY MONDAY NIGHT. SNOW AMOUNTS WERE MARGINAL FOR BOONE AND FAYETTE COUNTIES FOR THE WARNING. CONDITIONS IMPROVE 18Z MONDAY TO 00Z IN THE DOWNSLOPE AREAS ESPECIALLY WILLIAMSON...LOGAN...MADISON...CHARLESTON VICINITY. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... MONDAY NIGHT...MOST OF THE FORECAST AREA WILL HAVE TURNED TO ALL RAIN HOWEVER COLD AIR BECOMES WEDGED EAST OF APPALACHIANS AND NEAR THE SURFACE TEMPERATURES WILL LIKELY HANG AROUND TO SLIGHTLY BELOW FREEZING THROUGH THE NIGHT IN THE MOUNTAINS. WARM LAYER ALOFT IS MAKING FORECASTING P-TYPES MONDAY NIGHT A CHALLENGE FOR THE MOUNTAINS. CURRENT THINKING IS STARTING THE NIGHT WITH A WINTRY MIX AND THEN TRANSITIONING TO FREEZING RAIN. POCAHONTAS COUNTY WILL LIKELY SEE THE BRUNT OF THE ICING WITH AMOUNTS OF OVER A QUARTER OF AN INCH POSSIBLE. THE OTHER CONCERN THIS FORECAST PERIOD WILL BE RAINFALL ACROSS THE LOWLANDS MONDAY NIGHT. CURRENT QPF AMOUNTS FROM MONDAY AFTERNOON THROUGH TUESDAY ARE CLOSE TO AN INCH IN SOME AREAS AND MINOR FLOODING ISSUES COULD OCCUR AS RAIN FALLS ONTO FRESH SNOW FROM EARLIER IN THE EVENT AND FROZEN GROUND. HOWEVER...TEMPERATURES LOOK TO REMAIN IN THE UPPER 30S TO POSSIBLE LOW 40S SO NOT EXPECTING A RAPID SNOW MELT AND THE NEW SNOW ON THE GROUND SHOULD BE ABLE TO ABSORB A LOT OF THE WATER. AT THIS TIME WAS NOT CONFIDENT ENOUGH IN ANY HYDRO CONCERNS TO ISSUE A FLOOD WATCH...BUT WILL HIGHLIGHT IN THE HWO FOR NOW. AFTER A DRIER BUT OVERCAST INTERLUDE BETWEEN SYSTEMS TUE...06Z MODEL RUNS ARE FARTHER S WITH ANOTHER UPPER LEVEL S/W TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM PROGGED TO CROSS TUE NT. THIS WOULD BRING COLDER AIR BACK INTO THE AREA FROM THE W THROUGHOUT THE COLUMN OVERNIGHT TUE NT...CHANGING ANY RAIN...FREEZING RAIN OR MIXED PRECIPITATION THAT RETURNS TUE EVENING...BACK TO SNOW...WITH LIGHT ADDITIONAL AMOUNTS POSSIBLE OF GENERALLY 1 TO 3 INCHES. USED MOSTLY NAM FOR TEMPERATURES ALOFT AND USED A VARIETY OF GUIDANCE AS WELL AS PREVIOUS OFFICIAL FORECAST FOR SFC TEMPS. QPF AMOUNTS ARE GENERALLY A MIX BETWEEN RFC AND MODEL GUIDANCE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... OVERALL...QUIET AND WARMER WEATHER WILL TAKE HOLD IN THE LONG TERM. STILL SOME LIGHT UPSLOPE SNOW SHOWERS LINGERING BEHIND DEPARTING CLIPPER EARLY THURSDAY...BUT DRIER...AND WARMER AIR WILL GRADUALLY TAKE HOLD AS HIGH PRESSURE SURFACE AND ALOFT BUILD INTO THE REGION. TEMPERATURES TOWARDS THE END OF THE WEEK COULD EVEN CLIMB INTO THE 50S TO LOWER 60S ACROSS THE LOWLANDS...AS WAA INCREASES OUT AHEAD OF AN APPROACHING LOW...WHICH WILL SWEEP A COLD FRONT INTO THE REGION OVER THE WEEKEND...WITH LIGHT RAIN SHOWERS...AND COOLER TEMPERATURES TO END THE WEEK. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... CONDITIONS WILL CONTINUE TO DETERIORATE THIS EVENING WITH LIGHT TO MODERATE SNOWFALL OVERSPREADING THE AREA FROM WEST TO EAST. LOWEST VISIBILITIES WITH IFR TO LIFR CONDITIONS WILL BE WITH HEAVIEST SNOW...WHICH IS EXPECTED TONIGHT ACROSS EASTERN KENTUCKY EXTREME SOUTHERN OHIO...AND THROUGH CENTRAL AND SOUTHERN WEST VIRGINIA AND INTO SOUTHWEST VIRGINIA. THE SNOW WILL LIKELY CHANGE TO SLEET AND THEN RAIN IN THE WESTERN LOWLANDS FROM 12Z TO 18Z MONDAY. THERE MAY BE A PERIOD OF FREEZING RAIN AS WELL...BUT AT THIS TIME CONFIDENCE IS TOO LOW TO PUT IT IN THE FORECAST EXCEPT FOR BECKLEY WHERE THE FREEZING RAIN IS MOST LIKELY TO DEVELOP DURING THAT SAME TIME FRAME. SOME IMPROVEMENT IN CEILINGS AND VISIBILITY WILL BE POSSIBLE LATE TOMORROW MORNING AND EARLY TOMORROW AFTERNOON...HOWEVER WARM AND MOIST AIR MOVES IN LATER TOMORROW AFTERNOON OVER THE COLD SNOW COVERED SURFACE AND VISIBILITIES AND CEILINGS WILL LIKELY DROP DUE TO FOG AND RAIN. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY... FORECAST CONFIDENCE: MEDIUM ALTERNATE SCENARIOS: VISIBILITY MAY IMPROVE AGAIN 06Z TO 12Z MONDAY ACROSS NORTHERN COUNTIES AS PRECIPITATION TEMPORARILY DECREASES ACROSS THAT CORRIDOR WITH DRIER AIR MOVING IN. TIMING OF THE TRANSITION FROM SNOW TO RAIN COULD BE LATER AND ALSO VISIBILITIES MAY DROP TO IFR OR BELOW TOMORROW AFTERNOON AND EVENING WITH ADVECTION FOG. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EST 1HRLY 19 20 21 22 23 00 01 02 03 04 05 06 CRW CONSISTENCY L L L L L L L L L L L L HTS CONSISTENCY L L L L L L L L L L L M BKW CONSISTENCY L L L L L L L L L L L L EKN CONSISTENCY H M M L L L L L L L L M PKB CONSISTENCY M M M M M M M M L L M M CKB CONSISTENCY H H M L L L M M M M M M AFTER 00Z TUESDAY... PROLONGED IFR CONDITIONS WILL LIKELY PERSIST IN MID OHIO VALLEY AND CENTRAL APPALACHIANS INTO WEDNESDAY. LOW CEILINGS AND VSBY IN MOSTLY RAIN AND FOG MONDAY NIGHT INTO TUESDAY...THEN MIXED LIGHT RAIN AND SNOW TUESDAY NIGHT INTO WEDNESDAY. && .EQUIPMENT... HAVING ON/OFF PROBLEMS WITH THE CKB ASOS. TEMPERATURE READING TOO WARM AT TIMES. TROUBLE TICKET STILL EXISTS. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR WVZ007-008- 016-027. WINTER STORM WARNING UNTIL 1 PM EST MONDAY FOR WVZ005-006- 013>015. WINTER STORM WARNING UNTIL 7 PM EST MONDAY FOR WVZ024>026- 033>036. WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR WVZ009>011- 017>020-028>032-039-040. WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ037-038- 047. WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ046. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR OHZ083>087. WINTER WEATHER ADVISORY UNTIL 3 PM EST MONDAY FOR OHZ066-067- 075-076. KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR KYZ101. WINTER STORM WARNING UNTIL 1 PM EST MONDAY FOR KYZ102-103-105. VA...WINTER STORM WARNING UNTIL 7 PM EST MONDAY FOR VAZ003-004. && $$ SYNOPSIS...KTB/MPK/SL NEAR TERM...JW SHORT TERM...MPK LONG TERM...SL AVIATION...MPK EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NORMAN OK
1207 PM CST SAT FEB 13 2016 .AVIATION... GUSTY SOUTHEAST WINDS WILL PREVAIL THROUGH THE EVENING WITH A FEW HIGH CLOUDS. MOISTURE RETURN LATE THIS EVENING AND OVERNIGHT WILL RESULT IN AT LEAST MVFR CEILINGS...ESPECIALLY AFTER 6Z. A LITTLE UNSURE HOW FAR LOW CEILINGS WILL EXTEND IN WEST CENTRAL AND NORTHWEST OKLAHOMA. A FRONT WILL MOVE ACROSS ALL TAF SITES BY 18Z SUNDAY WITH NORTH TO NORTHWEST WINDS BEHIND THE FRONT. IFR CEILINGS MAY DEVELOP JUST AHEAD AND SHORTLY BEHIND THE FRONTAL PASSAGE. WILL ALSO MENTION THE POTENTIAL FOR FOG WITH BETTER CHANCES IN AND AROUND OKC/OUN. && .PREV DISCUSSION... /ISSUED 1050 AM CST SAT FEB 13 2016/ DISCUSSION... CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON. SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A LITTLE WARMER IN SOME AREAS. PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/ DISCUSSION... AVIATION... EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER. PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/ DISCUSSION... SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA. HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10 HOBART OK 55 44 63 36 / 0 0 0 0 WICHITA FALLS TX 62 48 68 40 / 0 0 0 10 GAGE OK 55 34 60 29 / 0 0 0 10 PONCA CITY OK 45 34 58 33 / 0 10 10 0 DURANT OK 56 46 62 44 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS NORMAN OK
1050 AM CST SAT FEB 13 2016 .DISCUSSION... CIRCULATION FROM COLD HIGH PRESSURE OVER IOWA WILL KEEP NORTH CENTRAL AND CENTRAL OKLAHOMA THE COOLEST THIS AFTERNOON. SURFACE WINDS HAVE ALREADY SHIFTED TO A EAST AND SOUTHEAST DIRECTION THIS MORNING...AND SHOULD KEEP A SOUTHEAST COMPONENT DURING THE AFTERNOON. THE HRRR AND RAP APPEAR A LITTLE WARM WITH HIGHS THIS AFTERNOON (SLIGHTLY VEERED FLOW)...BUT HAVE TRENDED A LITTLE WARMER IN SOME AREAS. && .PREV DISCUSSION... /ISSUED 604 AM CST SAT FEB 13 2016/ DISCUSSION... AVIATION... EAST WINDS WILL TURN SOUTH TODAY AND INCREASE AHEAD OF A SURFACE TROUGH. MVFR CEILINGS ARE EXPECTED TO MOVE NORTHWARD TONIGHT FROM TEXAS WHERE LOWER-LEVEL MOISTURE IS HIGHER. PREV DISCUSSION... /ISSUED 324 AM CST SAT FEB 13 2016/ DISCUSSION... SLIGHTLY COOLER WEATHER IS EXPECTED TODAY IN THE WAKE OF THE AIRMASS THAT IS DRIFTING OFF TO THE NORTHEAST OF OKLAHOMA. HOWEVER, THE SUNDAY AND NEXT WEEK WILL SEE INCREASING WARMING TO THE POINT OF HOT BY THE LATER PART OF THE WEEK. BEFORE THAT, RAIN CHANCES CROSS THROUGH EASTERN AND SOUTHEASTERN OKLAHOMA SUNDAY AND EARLY MONDAY WHEN SEVERAL SURFACE TROUGHS AND WEAK UPPER WAVES PASS BY. BEYOND THEN, NO PRECIPITATION IS EXPECTED THROUGH NEXT WEEK. THE MAIN WEATHER IMPACT WILL LIKELY BE INCREASED FIRE WEATHER POTENTIAL, ESPECIALLY THURSDAY WHEN GUSTY SOUTHWEST WINDS AND TEMPERATURES IN THE 70S AND 80S ARE EXPECTED. A WEAK FRONT IN THE WEEKEND WILL BRING LOWER, BUT STILL SEASONABLY HIGH TEMPERATURES. && .PRELIMINARY POINT TEMPS/POPS... OKLAHOMA CITY OK 53 43 62 38 / 0 10 10 10 HOBART OK 55 44 63 36 / 0 0 0 0 WICHITA FALLS TX 62 48 68 40 / 0 0 0 10 GAGE OK 55 34 60 29 / 0 0 0 10 PONCA CITY OK 45 34 58 33 / 0 10 10 0 DURANT OK 56 46 62 44 / 0 10 20 30 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...NONE. TX...NONE. && $$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
201 PM PST SAT FEB 13 2016 .SYNOPSIS...A STRONG WARM FRONT IS SPREADING RAIN AND BREEZY CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS AFTERNOON. RAIN WILL BECOME HEAVY AT TIMES...ESPECIALLY ALONG THE COAST AND IN THE HIGHER TERRAIN. SNOW LEVELS ARE STARTING OFF NEAR THE CASCADE PASSES...BUT ARE EXPECTED TO RISE TONIGHT AS WARMER AIR MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA SUNDAY...THEN LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN. HIGH PRESSURE WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY...ESPECIALLY FOR SOUTHERN ZONES. AN UPPER LEVEL TROUGH IS EXPECTED TO BRING COOLER AND SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW POSSIBLE FOR THE CASCADE PASSES AND ABOVE. && .SHORT TERM...TONIGHT THROUGH TUESDAY...NWS DOPPLER RADAR SHOWS RAIN SPREADING EASTWARD ACROSS THE FORECAST AREA THIS AFTERNOON...MAINLY NORTH OF A LINCOLN CITY TO SALEM LINE. THIS IS ASSOCIATED WITH A POTENT PACIFIC FRONTAL SYSTEM WHICH WILL PUSH A WARM FRONT ACROSS THE FORECAST AREA TONIGHT. LOOKING AT THE BIGGER PICTURE...THIS FRONTAL SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY BACK TO THE SUBTROPICAL LATITUDES NEAR THE DATELINE. BLENDED PRECIPITABLE WATER VALUES SHOW 1.2 INCH OR HIGHER WITHIN THIS MOISTURE PLUME AS FAR EAST AS 130W. 12Z NAM/GFS SUGGEST PW VALUES AROUND 1 INCH REACHING OUR FORECAST AREA THIS EVENING...COUPLED WITH OROGRAPHICALLY FAVORABLE W-SW WINDS OF 40-50 KT AT 850 MB. THIS SHOULD YIELD A PERIOD OF FAIRLY HEAVY RAINFALL FOR THE COAST AND HIGHER TERRAIN... ESPECIALLY NORTHERN ZONES WHERE 2-4 INCHES OF RAIN ARE POSSIBLE BY SUNDAY. INLAND VALLEYS WILL SEE LESS...RANGING FROM AROUND 0.50 INCH SOUTH OF SALEM TO AROUND 1 INCH IN THE PDX METRO. 12Z GFS SHOWS THE BEST ISENTROPIC LIFT MOVING THROUGH BY MIDNIGHT TONIGHT. AFTER THAT FORCING MOVES EAST...THE WILLAMETTE VALLEY WILL LIKELY BE HEAVILY RAIN SHADOWED IN LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY. SNOW AMOUNTS REMAIN A CHALLENGING FORECAST FOR THE CASCADES WITH THIS SYSTEM. OFTEN TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT HEAT PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD A BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE ONE OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING IN ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. SOME WET SNOW IS POSSIBLE FOR THE PASSES THIS AFTERNOON INTO THIS EVENING...BUT ACCUMULATIONS SHOULD BE LIGHT. HIGHER SKI RESORT ELEVATIONS LOOK MORE LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000 FEET SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED...SNOW ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF THAT IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER WILL BE QUICK LATER TONIGHT OR SUNDAY MORNING. NOT EXPECTING TO CHANGE MUCH WITH THE EXISTING WINTER WX ADVISORY FOR SNOW...THOUGH WILL PROBABLY ADD SOME WORDING TO SUGGEST THE GREATEST ACCUMULATIONS WILL LIKELY REMAIN UP IN THE HIGHER SKI RESORT ELEVATIONS. THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST- RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT...BUT SIGNIFICANT MAIN STEM RIVER FLOODING IS NOT EXPECTED AT THIS TIME. UPPER LEVEL RIDGING WILL BEGIN BUILDING IN FROM THE SW SUNDAY...BUT WEAK SHORTWAVES WILL LIKELY RIDE OVER THE TOP OF THE RIDGE AND REMAIN INTACT TO KEEP SOME RAIN IN THE PICTURE THROUGH SUN EVENING. DRYING TREND IS EXPECTED MON/TUE AS THE UPPER RIDGE SHOVES THE MAIN BAROCLINIC ZONE NORTHWARD INTO WA/BC. SW WA MAY REMAIN CLOSE ENOUGH TO THE FRONTAL ZONE TO KEEP SOME RAIN OR DRIZZLE AROUND...BUT AREAS PDX METRO SOUTHWARD SHOULD BE MAINLY DRY MON/TUE. STRENGTHENING INVERSIONS MAY PROMOTE NIGHT AND MORNING FOG... ESPECIALLY SOUTH OF SALEM WHERE SKIES HAVE THE BEST CHANCE OF CLEARING. ANY FOG THAT DOES DEVELOP MAY BE STUBBORN. DID NOT FACTOR THIS INTO MON/TUE MAX TEMP FORECASTS YET...AS THERE REMAINS A GOOD DEAL OF UNCERTAINTY AS TO IF AND WHERE FOG WILL DEVELOP. WEAGLE .LONG TERM...TUESDAY NIGHT THROUGH FRIDAY...THE UPPER RIDGE RESPONSIBLE FOR THE DRYING TREND MON/TUE WILL SHIFT EAST MIDWEEK... WITH MODELS SHOWING GOOD CONSENSUS IN BRINGING A WELL DEFINED UPPER TROUGH INTO THE PAC NW AND POSSIBLY CALIFORNIA WED NIGHT/THU. THIS WILL CAUSE RAIN CHANCES TO INCREASE LATER WED...WITH COOL AND SHOWERY WEATHER LINGERING INTO THU. AIR MASS WILL START OUT RATHER WARM WITH SNOW LEVELS WELL ABOVE THE CASCADE PASSES WED. COLDER AIR WILL MOVE IN WITH THE UPPER TROUGH...WITH SNOW LEVELS LOWERING TO 3000 TO 3500 FEET IN SHOWERS BY THURSDAY. EXPECT TEMPS TO DROP BACK TO NEAR NORMAL LATE WEEK AS A RESULT OF THE UPPER TROUGH...POSSIBLY EVEN A LITTLE BELOW NORMAL. MODELS SHOW DECENT AGREEMENT THAT THIS UPPER TROUGH WILL BE FOLLOWED BY A MORE PROGRESSIVE FRONTAL SYSTEM FOR MORE RAIN AND CASCADE SNOW FRI/FRI NIGHT. WEAGLE && .AVIATION...WARM-FRONTAL PRECIP BEGINNING TO SPREAD INTO THE S WASHINGTON AND N OREGON COAST EARLY THIS AFTERNOON. VFR ACROSS THE AREA...EXCEPT AREAS OF MVFR ALONG THE COAST. FLIGHT CONDITIONS ALONG THE COAST DETERIORATE THROUGH THE AFTERNOON AND EARLY EVENING...DROPPING TO IFR BY 00Z SUN. MVFR COVERAGE TO INCREASE OVER THE INTERIOR LOWLANDS AFTER 00Z SUN. INTERIOR VALLEYS MAY SEE MORE VFR OVERNIGHT THROUGH SUN DUE TO RAIN-SHADOW EFFECTS. STRONG 850 MB WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT OVER THE HIGHER TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND IFR OR WORSE FLIGHT CONDITIONS. KPDX AND APPROACHES...VFR AT 21Z. CIGS WILL CONTINUE TO LOWER THROUGH THE AFTERNOON AND EARLY EVENING...WITH MVFR CONDITIONS LIKELY AFTER 02Z SUN...ESPECIALLY ALONG WRN APPROACHES. S WIND SHOULD ALLOW FOR LONGER-DURATION VFR CONDITIONS OVERNIGHT THROUGH SUN. WEISHAAR && .MARINE...WIND GUSTS ON THE EDGE OF GALE FORCE OVER THE NRN OUTER WATERS EARLY THIS AFTERNOON. THE 14Z RUC RUN WAS A LITTLE STRONGER COMPARED TO THE 12Z NAM. GALE FORCE WIND GUSTS OVER THE OUTER NRN WATERS THROUGH 06Z SUN. HELD ON TO THEM A LITTLE LONGER OVER THE NRN INNER WATERS...EXTENDING THE GALE TO 08Z. WILL ALSO NEED TO WATCH THE NRN PART OF PZZ255 AND PZZ275 AS GUSTS COULD TOUCH GALE FORCE TONIGHT. MODELS IN DECENT AGREEMENT SHOWING SMALL CRAFT ADVISORY SPEEDS LATE TONIGHT THROUGH EARLY SUN AFTERNOON. 12Z NAM BOUNDARY LAYER WIND SPEEDS A LITTLE STRONGER 18Z SUN COMPARED TO THE GFS. WIND SPEEDS EASE A BIT MON AS THE WARM FRONT LIFTS N...REDUCING THE SURFACE GRADIENT. BASICALLY WENT WITH THE GFS FOR WIND MON THROUGH TUE NIGHT. MODEL DIFFERENCES BECOME GREATER WED THROUGH THU REGARDING THE NEXT SIGNIFICANT WEATHER SYSTEM. THE ECMWF SEEMS TO BE MORE CONSISTENT...SHOWING POSSIBLE GALES LATE WED THROUGH EARLY THU MORNING. A LONG PERIOD NW SWELL WILL MAINTAIN SEAS 12 TO 15 FT THROUGH TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT LATE NEXT WEEK AND POSSIBLY NEAR 20 FT NEXT WEEKEND. WANT TO SEE A FEW MORE RUNS BEFORE GOING THAT HIGH. CAPPED SEAS TO AROUND 15 FT FOR NOW. WEISHAAR && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR NORTHERN OREGON CASCADES. WA...WINTER WEATHER ADVISORY UNTIL 4 AM PST SUNDAY FOR SOUTH WASHINGTON CASCADES. PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 AM PST SUNDAY. GALE WARNING UNTIL MIDNIGHT PST TONIGHT FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1009 AM PST SAT FEB 13 2016 .SYNOPSIS...A STRONG WARM FRONT WILL SPREAD INCREASING RAIN AND BREEZY CONDITIONS INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON THIS AFTERNOON AND TONIGHT...WITH RAIN HEAVY AT TIMES. SNOW LEVELS WILL START NEAR THE CASCADE PASSES TODAY...BUT SHOULD RISE TONIGHT AS WARMER AIR MOVES IN. THE FRONTAL ZONE WILL LINGER OVER THE AREA SUNDAY...THEN LIFT NORTH SUNDAY NIGHT AND MONDAY FOR DECREASING RAIN. HIGH PRESSURE WILL BRING DRIER WEATHER LATER MONDAY INTO TUESDAY... ESPECIALLY FOR SOUTHERN ZONES. AN UPPER LEVEL TROUGH WILL BRING COOLER AND SHOWERY WEATHER LATER WEDNESDAY INTO THURSDAY...WITH SNOW POSSIBLE FOR THE CASCADE PASSES AND ABOVE. && .MORNING UPDATE...NWS DOPPLER RADAR SHOWS WARM FRONTAL RAIN STARTING TO MOVE ONSHORE TILLAMOOK NORTHWARD...THE START OF WHAT WILL BE A VERY WET PERIOD WHICH SHOULD LAST INTO SUNDAY. LOOKING AT THE BIGGER PICTURE...THIS FRONTAL SYSTEM HAS A DECENT MOISTURE TAP ALL THE WAY BACK TO THE SUBTROPICAL LATITUDES NEAR THE DATELINE. BLENDED PRECIPITABLE WATER VALUES SHOW 1.2 INCH OR HIGHER WITHIN THIS MOISTURE PLUME AS FAR EAST AS 135W. 12Z NAM/GFS SUGGEST PW VALUES AROUND 1 INCH REACHING OUR FORECAST AREA THIS EVENING...COUPLED WITH OROGRAPHICALLY-FAVORABLE W-SW WINDS OF 40-50 KT AT 850 MB. THIS SHOULD YIELD A PERIOD OF FAIRLY HEAVY RAINFALL FOR THE COAST AND HIGHER TERRAIN...ESPECIALLY NORTHERN ZONES WHERE 2-4 INCHES OF RAIN ARE POSSIBLE BY SUNDAY. INLAND VALLEYS WILL SEE LESS...RANGING FROM ABOUT 0.50 INCH NEAR EUGENE TO 0.75-1.50 INCH IN THE PDX METRO. 12Z GFS SHOWS THE BEST ISENTROPIC LIFT MOVING THROUGH BY MIDNIGHT TONIGHT...AFTER THAT THE WILLAMETTE VALLEY IS LIKELY TO BE HEAVILY RAIN SHADOWED IN LOW-LEVEL WESTERLY FLOW LATER TONIGHT INTO SUNDAY. SNOW AMOUNTS WILL BE TRICKY FOR THE CASCADES WITH THIS SYSTEM. OFTEN TIMES...LEFTOVER COLD AIR...WET-BULB EFFECTS AND LATENT HEAT PROCESSES WILL HOLD ON TO LOWER SNOW LEVELS MOUNT HOOD NORTHWARD A BIT LONGER THAN MODELS EXPECT. HOWEVER THIS DOES NOT APPEAR TO BE ONE OF THOSE SCENARIOS AS FAIRLY STRONG WARM ADVECTION WILL BE MOVING IN ON THE 40-50 KT W-SW 850-700 MB FLOW LATER TONIGHT. THERE WILL PROBABLY BE SOME WET SNOW AT THE PASSES DURING THE ONSET OF PRECIPITATION THIS AFTERNOON INTO THIS EVENING...BUT THIS SHOULD CHANGE TO RAIN BY SUNDAY MORNING. HIGHER SKI RESORT ELEVATIONS LOOK MORE LIKELY TO SEE 5-10 INCHES BEFORE SNOW LEVELS SKYROCKET TO 7000 FEET SUNDAY MORNING. IF SNOW LEVELS REMAIN LOWER THAN EXPECTED... SNOW ACCUMULATIONS COULD BE SUBSTANTIALLY HIGHER GIVEN THE HEAVY QPF THAT IS EXPECTED. HOWEVER...AM FAIRLY CONFIDENT THAT THE CHANGEOVER WILL BE QUICK LATER TONIGHT OR SUNDAY MORNING. CURRENT WINTER WX ADVISORY FOR SNOW APPEARS TO HANDLE ALL THIS WELL AND WILL NOT BE MAKING ANY CHANGES FOR THE MORNING PACKAGE. THE HEAVY RAINFALL MAY CAUSE SOME MINOR HYDROLOGIC ISSUES...MAINLY FOR CREEKS AND SMALL STREAMS DRAINING OUT OF THE COAST RANGE AND CASCADES. THE GRAYS RIVER IN WAHKIAKUM COUNTY IS NOTORIOUSLY FAST- RESPONDING...SO 2-4 INCHES OF RAIN IN A 24 HOUR PERIOD MAY PUSH IT CLOSE TO BANKFULL. WILL BE KEEPING A CLOSE EYE ON THIS RIVER AMONG OTHERS AS RAIN INCREASES LATER TODAY AND TONIGHT. WEAGLE /PREV DISC ISSUED 339 AM PST SAT FEB 13 2016/ .SHORT TERM...THE UPPER TROUGH ASSOCIATED WITH THE FRONTAL SYSTEM FROM FRIDAY MOVED EASTWARD THROUGH SOUTHWEST WASHINGTON AND FAR NORTHWEST OREGON OVERNIGHT...PRODUCING SHOWERS OVER MUCH OF THE FORECAST AREA AND A FEW THUNDERSTORMS OVER THE NORTH COASTAL WATERS AND THE IMMEDIATE COAST. THIS ACTIVITY WILL CONTINUE DECREASING THIS MORNING. ATTENTION THEN TURNS TO THE WARM FRONT APPROACHING 130W EARLY THIS MORNING THAT WILL MOVE INTO THE FORECAST AREA THIS AFTERNOON AND REMAIN OVER THE AREA THROUGH MUCH OF SUNDAY. THE FIRST WAVE ALONG THIS WARM FRONT WILL SPREAD HEAVY RAIN INTO THE AREA THIS AFTERNOON AND THROUGH AT LEAST THIS EVENING...WITH BRISK WINDS AT THE COAST AND LOCALLY INLAND. THIS WAVE IS ACCOMPANIED BY 1.2 INCH PRECIPITABLE WATER VALUES AND 850 MB WINDS OF NEARLY 50 KT. THIS WAVE MOVES EAST OF THE AREA LATER SATURDAY NIGHT...BUT IS FOLLOWED BY ONE OR TWO MORE SLIGHTLY WEAKER WAVES THAT KEEP THE RAIN GOING THROUGH SUNDAY...THOUGH AT LESSER RAINFALL RATES. SNOW LEVELS WILL START OUT IN THE CASCADES BETWEEN 3500 AND 4500 FEET TODAY...AND WILL LINGER NEAR THE PASSES INTO TONIGHT. HAVE ISSUED A SNOW ADVISORY OF THE SOUTH WASHINGTON CASCADES FROM NOON UNTIL AFTER MIDNIGHT TONIGHT...ALSO THE NORTH OREGON CASCADES UNTIL 10 PM TONIGHT. THE SNOW LEVEL DRAMATICALLY RISES FROM SOUTH TO NORTH TONIGHT TO WELL ABOVE THE PASSES...TO WELL ABOVE 6000 FEET. RAINFALL AMOUNTS OF 4 TENTHS OF TO OVER 1 INCH ARE POSSIBLE THIS WEEKEND IN THE VALLEYS...WITH 2 TO 4 INCHES ALONG THE COAST AND IN THE COAST RANGE AND THE CASCADES. THIS SURGE OF RAIN SHOULD CAUSE MANY OF OUR FASTER RESPONDING RIVERS TO RISE RAPIDLY...PARTICULARLY THE GRAYS RIVER IN WAHKIAKUM COUNTY...BUT MAIN STEM RIVER FLOODING IS NOT ANTICIPATED. THE PERIOD WITH THE BEST CHANCE OF ANY URBAN TYPE FLOODING WOULD BE LATER TODAY AND THIS EVENING. THE WARM FRONT SHOULD MOVE MOSTLY NORTH OF OUR FORECAST AREA SUNDAY NIGHT AND MONDAY WITH DECREASING RAIN. AS WE GET INTO THE WARM SECTOR...WE COULD SEE TEMPS BACK INTO THE LOWER 60S AT LOWER ELEVATIONS MONDAY. TOLLESON .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS... MONDAY NIGHT THROUGH FRIDAY...SHORTWAVE RIDGING EARLY IN THE WEEK WILL ONCE AGAIN GIVE WAY TO A MORE ACTIVE WEATHER PATTERN DURING THE MIDDLE TO LATTER HALF OF NEXT WEEK. THE REMNANTS OF AN ATMOSPHERIC RIVER EVENT MAY DIP FAR ENOUGH SOUTH TO BRING SOME LIGHT RAIN TO THE REGION TUESDAY...BUT CONFIDENCE IS LOW. MODELS HAVE BEEN IN MUCH BETTER AGREEMENT THAT A SHORTWAVE TROUGH WILL SWING INTO THE WESTERN UNITED STATES AND BRING WET AND COOLER WEATHER WEDNESDAY INTO THURSDAY. AN ADDITIONAL STORM SYSTEM APPEARS POSSIBLE TOWARDS THE END OF NEXT WEEK. TEMPERATURES FOR THE MOST PART SHOULD REMAIN NEAR TO ABOVE NORMAL WITH ANY BOUTS OF PRECIPITATION LOOKING TO REMAIN LIGHT ENOUGH THAT WE DO NOT FORESEE ANY MAJOR HYDROLOGIC ISSUES IN THE NEXT WEEK. AB/NEUMAN && .AVIATION...GENERALLY VFR AT 16Z...EXCEPT FOR AREAS OF MVFR ALONG THE S WASHINGTON AND FAR N OREGON COAST. THE NEXT WARM FRONT WILL IMPACT THE AREA LATE THIS AFTERNOON THROUGH SUNDAY. EXPECT CONDITIONS TO DETERIORATE WITH INCREASING RAIN FROM NW TO SE MID TO LATE AFTERNOON THROUGH TONIGHT...WITH IFR LIKELY ALONG THE COAST. INTERIOR VALLEYS MAY ACTUALLY REMAIN VFR THIS AFTERNOON THROUGH TONIGHT DUE TO SOME RAIN-SHADOW EFFECTS. STRONG 850 MB WEST FLOW WILL RESULT IN ENHANCED OROGRAPHIC LIFT OVER THE HIGHER TERRAIN...RESULTING IN MOUNTAIN OBSCUREMENT AND IFR OR WORSE FLIGHT CONDITIONS. KPDX AND APPROACHES...VFR PREVAILING TODAY...EXCEPT FOR POSSIBLE MVFR CIGS MID TO LATE-AFTERNOON THROUGH EARLY EVENING AS PRECIP INCREASES. S WIND SHOULD ALLOW FOR PRIMARILY VFR CONDITIONS LATER THIS EVENING THROUGH SUN MORNING. && .MARINE...WIND WILL INCREASE TODAY AS A WARM FRONT MOVES THROUGH THE WATERS. 14Z RUC RUN A LITTLE STRONGER COMPARED TO THE LATEST NAM. EXPECT SMALL CRAFT ADVISORY WIND SPEEDS TO RAMP UP TO GALE FORCE WIND GUSTS LATE THIS EVENING OVER THE N OUTER WATERS. GALES TO SPREAD INTO THE N INNER WATERS OVERNIGHT. GALES COULD LAST A LITTLE LONGER THAN CURRENT FORECAST IMPLIES...BUT WILL LOOK AT THAT MORE FOR THE AFTERNOON. RAMPED UP WIND SPEEDS A BIT SUN...WITH SOLID SMALL CRAFT ADVISORY SPEEDS EXPECTED. A LONG PERIOD NW SWELL WILL MAINTAIN 11 TO 13 FT SEAS TODAY THEN 12 TO 15 FT TONIGHT AS THE WIND WAVE COMPONENT INCREASES. SEAS WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT LATE NEXT WEEK. && .PQR WATCHES/WARNINGS/ADVISORIES... OR...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM PST THIS EVENING FOR NORTHERN OREGON CASCADES. WA...WINTER WEATHER ADVISORY FROM NOON TODAY TO 4 AM PST SUNDAY FOR SOUTH WASHINGTON CASCADES. PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10 TO 60 NM. SMALL CRAFT ADVISORY FOR WINDS FROM 1 PM THIS AFTERNOON TO 6 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM PST SUNDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM PST SUNDAY. GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 10 NM. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1230 PM EST SAT FEB 13 2016 .SYNOPSIS... POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS EASTERN PA ON TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... UPDATED GRIDS FOR TEMPS/WINDS AND SNOW SHOWERS FOR QUICK LOOK AND ACCIDENT ON I78 IN LEBANON COUNTY WHICH HAS EM PERSONNEL WORKING ON SITE OF ACCIDENT. PREVIOUS: ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY. TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES. STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF THE REGION TODAY INTO SUNDAY. WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO. RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING. MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND IN NORTHWESTERN PA THIS EVENING. COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/... MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS. THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD VALENTINES AT LEAST OUTDOORS. THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW SUNDAY LIKELY WILL BE EARLY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... *IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT WEEK. BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS. WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY. NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS THROUGH THE GREAT LAKES TO THE WEST OF PA. && .AVIATION /18Z SATURDAY THROUGH THURSDAY/... ARCTIC AIR HAS BROUGHT COLD TEMPERATURES AND STRONG GUSTY WINDS TO THE REGION. SNOW SQUALLS ARE COMMON IN THE WESTERN MOUNTAINS WITH IMPACTS ON KJST AND KBFD. SOME OF THE STRONGER LAKE STREAMERS AND SNOW SHOWERS HAVE MADE TO THE MARYLAND BORDER IN SOUTHEASTERN PA. SO SNOW AND BLOWING SNOW IS POSSIBLE WITH THE STRONG GUSTY WINDS. GOOD GUST SPREADS TOO WHICH AFFECT TAKEOFF/LANDINGS. GUSTS OVER 30KTS HAVE BEEN OBSERVED. IFR AND MVFR MOST OF WEST. VFR WITH TIME MVFR IN CENTRAL AREAS. MOSTLY VFR WITH TIMES MVFR WITH SNOW/BLOWING SNOW IN SOME PARTS OF SOUTHEAST TODAY. THE SNOW SHOWERS AND WINDS WILL DIMINISH THIS EVENING AND OVERNIGHT. THINGS SHOULD BE MUCH NICER SUNDAY...THOUGH A TAD COLD. NEED A HEATED JOY STICK. HIGH PRESSURE SUNDAY DRIFTS EAST OVERNIGHT SO THE PERIOD OF NICE WEATHER WITH VFR WILL BE SHORT LIVED AS CLOUDS AND POTENTIAL PRECIPITATION MOVE IN FOR MONDAY AND INTO TUESDAY. SNOW AND ASSORTED WINTRY PRECIPITATION WILL LIKELY AFFECT FLYING MONDAY INTO TUESDAY. OUTLOOK... SUN...NO SIG WX EXPECTED MAINLY VFR. MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING. MON NIGHT AND TUE...SNOW LIKELY WRN HALF OF PENN...WITH RAIN AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS SET IN. LLWS POSS SE. WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037- 041-042. WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017- 018-024-033. WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059- 063>066. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...FITZGERALD NEAR TERM...GRUMM SHORT TERM...GRUMM/FITZGERALD LONG TERM...FITZGERALD/GARTNER AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1013 AM EST SAT FEB 13 2016 .SYNOPSIS... POLAR VORTEX OVR S QUEBEC WILL RAPIDLY LIFT NE BY LATE IN THE WEEKEND. A DEEPENING UPPER LVL TROF OVER THE CENTRAL CONUS WILL SPAWN A LOW PRES SYSTEM...WHICH WILL LIKELY TRACK NORTHWARD ACROSS EASTERN PA ON TUESDAY. && .NEAR TERM /UNTIL 7 PM THIS EVENING/... ARCTIC AIR MASS CONTINUES TO PUSH THROUGH THE REGION TODAY. TEMPERATURES WILL NOT MOVE TOO MUCH HIGHER THAN CURRENT VALUES. STRONG NORTHWEST WINDS AND TEMPERATURES IN JUST ABOVE ZERO IN THE NORTHWESTERN AREAS TO A BALMY MID-TEENS IN THE SOUTHEAST WILL PROVIDE FOR A VERY COLD DAY. WIND CHILLS BELOW ZERO OVER MOST OF THE REGION TODAY INTO SUNDAY. WIND GUSTS OF 25 TO 35 MPH HAVE BEEN OBSERVED SO FAR TODAY. COVER UP WELL IF OUTDOORS OVER THE NEXT 36 HOURS OF SO. RADAR AND SATELLITE IMAGERY SHOW HURON CONNECTION SNOW BANDS. ONE BAND MADE INTO STATE COLLEGE AROUND 9 AM FOR A QUICK COATING. THIS BAND IS MOVING TO THE SOUTHEAST AND COULD BRING LIGHT SNOW/FLURRIES TO LOWER SUSQUEHANNA VALLEY LATER THIS MORNING. MORE FOCUSED SNOW IS OVER SOUTHWEST MOUNTAINS. SNOW IN NORTHWESTER AREAS HAS BEEN QUITE LIMITED. THE NCAR 3KM EFS AND THE HRRR SEEM TO FOCUS SNOW IN SOUTHWEST MOUNTAINS AND HAVE LIMITED SNOW IN THEIR RESPECTIVE FORECASTS. THE AIR IS VERY DRY AND HAS NOT BEEN A PROLIFIC LAKE AND MOUNTAIN SNOW PRODUCER. HIGH RESOLUTION MODELS KEEP INDICATING THIS. HRRR AT TIMES SHOWS A POTENTIAL MODEST BAND IN NORTHWESTERN PA THIS EVENING. COLD WILL BE THE ISSUE OVER THE ENTIRE REGION. BEST ACCUMULATING SNOW POTENTIAL IN THE SOUTHWEST MOUNTAINS. && .SHORT TERM /7 PM THIS EVENING THROUGH 7 PM SUNDAY/... MODELS NOT VERY BIG IN SNOW OVERNIGHT INTO SUNDAY. SOME HINTS OF SNOW EARLY IN THE HRRR AND SREF IN SW MOUNTAINS. COMBINED WITH THE FALLING INVERSION HEIGHTS AHEAD OF APPROACHING HIGH...LES AND MOUNTAIN SNOW THREATS WILL DIMINISH. THE HIGH SHOULD DECOUPLE SOME AREAS OVERNIGHT AND WITH SNOW COVER A GOOD PERIOD OF RADIATIONAL COOLING IS POSSIBLE IN CENTRAL AND WESTERN AREAS. THE MASSIVE 1032 TO 1036 HIGH MOVES OVER THE REGION AND IS PARKED OVERHEAD BY MIDDAY SUNDAY. THIS SHOULD ENSURE THE WINDS DIE AND THE WINDCHILL ISSUE DIMINISH. BUT WILL STILL BE A VERY COLD VALENTINES AT LEAST OUTDOORS. THE EVENING SHOULD STILL HAVE NEAR IDEAL RADIATIONAL COOLING CONDITIONS. VERY COLD START TO THE OVERNIGHT PERIOD SUNDAY INTO MONDAY....BUT THE HIGH MOVES OFF FAST SUNDAY NIGHT. OVERNIGHT LOW SUNDAY LIKELY WILL BE EARLY. && .LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/... *IMPACT WEATHER HIGHLIGHTS: POTENTIAL WINTER STORM EARLY NEXT WEEK. BULK OF MED RANGE GUIDANCE INDICATES THE LIKELIHOOD OF SOME LGT SNOW ARRIVING MONDAY...AS SFC HIGH DRIFTS OFF THE COAST AND MILDER SOUTHERLY FLOW OVERRUNS RETREATING ARCTIC AIR MASS. HOWEVER...THE BIGGER CONCERN INVOLVES DIGGING UPPER TROF OVR THE MISS VALLEY AND ASSOC SFC LOW PRESSURE LIFTING UP THE APPALACHIANS. MDL SPREAD CONTINUES TO NARROW...WITH MOST RUNS TRACKING SFC LOW ACROSS EASTERN PA TUESDAY. THIS TRACK WOULD CERTAINLY FAVOR RAIN ACROSS EASTERN PA AND RAIN OR SNOW ACROSS WESTERN PA. GIVEN INHERENT MDL UNCERTAINTIES THIS FAR OUT...WILL MAINTAIN RAIN/SNOW IN THE FCST FOR MOST OF CENTRAL PA MON NIGHT-TUES. HAVE RAISED POPS INTO THE LIKELY CATEGORY BASED ON CONVERGING MDL SOLUTIONS. WILL ALSO HAVE TO WATCH FOR THE POSSIBILITY OF FLOODING ACROSS EASTERN PA...GIVEN RAINFALL AND SNOWMELT POTENTIAL. LATEST MDL ENSEMBLE RIVER FORECASTS USING NAEFS SUGGESTS MINOR FLOODING IS A POSSIBILITY ACROSS THE LOWER SUSQ VALLEY BY TUES. WPC ALSO HAS HIGHLIGHTED SE PA FOR A SLIGHT RISK OF FLOODING TUESDAY. NEAR TO ABOVE NORMAL TEMPS APPEAR LIKELY LATER NEXT WEEK...AS HEIGHTS ARE FORECAST TO RISE AND A PSBL LOW PRESSURE SYSTEM LIFTS THROUGH THE GREAT LAKES TO THE WEST OF PA. && .AVIATION /15Z SATURDAY THROUGH WEDNESDAY/... ARCTIC AIR MASS POURING INTO THE REGION EARLY THIS MORNING... CURRENTLY ACCOMPANIED BY GUSTY NW WINDS OF 15G25KTS. WINDS WILL PICK UP FURTHER DURING THE DAY...WITH GUSTS APPROACHING 40-45KTS...BEFORE GRADUALLY DIMINISHING TONIGHT. RADAR AT 11Z SHOWING SCT SHSN ACCOMPANYING ARRIVAL OF ARCTIC AIR MASS ACROSS WESTERN/CENTRAL MTNS. ARRIVAL OF LOW PWAT AIR MASS SHOULD CAUSE MOST OF THESE SNOW SHOWERS TO DISSIPATE EARLY IN THE DAY. SNOW SHOWERS WILL LINGER OVER WARREN COUNTY /WITH POSSIBLE BRIEF EXCURSIONS TOWARD KBFD/ WITH MORE PERSISTENT SNOW SHOWERS/BANDS ASSOC WITH LK HURON CONNECTION TO LAST THRU THE DAY ACROSS THE LAUREL HIGHLANDS /KJST/. RESTRICTIONS WILL PERSIST OVER WESTERN HIGHER TERRAIN. BUT WITH DOWNSLOPE FLOW KICKING IN FOR CENTRAL MTNS AND SE...VFR WILL BE THE GENERAL RULE - WITH JUST A CHANCE FOR SOME SCT SNOW BANDS TO CREEP INTO PORTIONS OF THE CENTRAL MTNS LATE DAY. OUTLOOK... SUN...NO SIG WX EXPECTED. MON...WIDESPREAD RESTRICTIONS DEVELOP WITH SNOW DEVELOPING. MON NIGHT AND TUE...SNOW LIKELY NW HALF OF PENN...WITH RAIN AND/OR SNOW IN THE SE. WIDESPREAD RESTRICTIONS CONTINUE. LLWS POSS SE. WED...ANOTHER WAVE SLIDES THROUGH KEEPING RESTRICTIONS IN PLACE ALONG WITH POTENTIAL FOR LIGHT SNOW...ESP OVER THE WEST. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING UNTIL 11 AM EST SUNDAY FOR PAZ004>006-037- 041-042. WIND CHILL ADVISORY UNTIL 11 AM EST SUNDAY FOR PAZ010>012-017- 018-024-033. WIND ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR PAZ019-025>028- 034>036-045-046-049>053-056>059-063>066. WIND CHILL ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM EST SUNDAY FOR PAZ019-025>028-034>036-045-046-049>053-056>059- 063>066. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ024- 033. && $$ SYNOPSIS...FITZGERALD NEAR TERM...GRUMM SHORT TERM...GRUMM/FITZGERALD LONG TERM...FITZGERALD/GARTNER AVIATION...RXR
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
158 PM MST SAT FEB 13 2016 .UPDATE... ISSUED AT 158 PM MST SAT FEB 13 2016 STRONG WINDS NOTED ALONG COLD FRONT MOVING INTO NORTHEAST WY...GUSTING OVER 60 MPH FOR A BRIEF PERIOD IN SOME AREAS. BOTH HRRR AND RUC SHOW THESE STRONG WINDS MOVING ACROSS NORTHEAST WY DURING THE AFTERNOON AND INTO THE BLACK HILLS AREA LATE THIS AFTERNOON/EARLY EVENING AS THE FRONT CROSSES. SHOWERS ACCOMPANYING THE FRONT WILL ALSO HELP TO MIX STRONGER WINDS ALOFT DOWN. HAVE DECIDED TO ISSUE A HIGH WIND WARNING FOR NORTHEAST WY AND MUCH OF THE BLACK HILLS AREA. WINDS SHOULD DIMINISH WITH THE FRONT AS IT MOVES EAST OF THE BLACK HILLS AND INTO COOLER AND MORE STABLE AIR TO THE EAST. UPDATE ISSUED AT 1238 AM MST SAT FEB 13 2016 CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER FAR SOUTHWEST SK... WITH WARM FRONT EXTENDING SOUTHEAST INTO THE BLACK HILLS AREA AND SOUTHWEST SD. COLD FRONT EXTENDS SOUTHWARD ACROSS CENTRAL MT INTO NORTHWEST WY. UPPER LEVEL ANALYSIS SHOWS STRONG SHORTWAVE MOVING EAST- SOUTHEAST ACROSS CENTRAL MT...WITH STRONG JET WRAPPING AROUND IT FROM THE NORTHERN ROCKIES THROUGH SD. LATEST OBS SHOW TEMPS RANGING FROM THE UPPER TEENS IN THE LEMMON AREA TO THE 50S OVER CAMPBELL CO WY. THE FREEZING LINE RIGHT NOW EXTENDS FROM NEAR BELLE FOURCHE TO NORTH OF PHILIP AND THEN SOUTH- SOUTHEAST TO MELLETTE AND TODD COUNTIES IN SOUTH CENTRAL SD. KUDX RADAR SHOWING SOME PCPN FROM MEADE CO INTO HAAKON AND ZIEBACH COUNTIES...MOSTLY IN THE FORM OF RAIN...WITH SOME FREEZING RAIN OR SNOW LIKELY OVER NORTHEAST MEADE INTO ZIEBACH CO. REGIONAL RADARS SHOW MORE ACTIVITY DEVELOP TO THE WEST OVER SOUTH CENTRAL MT AND NORTH CENTRAL WY NEAR THE SHORTWAVE AND COLD FRONT. SOME STRONG WINDS HAVE ALSO BEEN NOTED NEAR THE FRONT AND WITH SHOWER ACTIVITY THERE...AS TEMPS HAVE RISEN INTO THE 50S AND LOWER 60S. THESE SHOWERS AND WIND WILL MOVE INTO NORTHEAST WY EARLY THIS AFTERNOON AND REACH THE BLACK HILLS AREA LATE IN THE AFTERNOON. A SPECIAL WEATHER STATEMENT HAS BEEN ISSUED FOR THE STRONG WIND GUSTS EXPECTED WITH SHOWERS THIS AFTERNOON. UPDATE HAS BEEN SENT TO ADJUST PCPN TYPE THIS AFTERNOON BASED ON CURRENT TEMPS AND EXPECTED TRENDS. THE MAIN THREAT FOR FREEZING RAIN AND A LITTLE SNOW WILL BE FROM PERKINS INTO ZIEBACH COUNTIES THROUGH THE AFTERNOON. ICE ACCUMULATION UP TO A TENTH OF AN INCH IS STILL EXPECTED. HARDING COUNTY WILL SEE TEMPS RISE TO ABOVE FREEZING BY LATE AFTERNOON AS THE WARM FRONT MOVES THROUGH... EVENTUALLY SWITCHING PCPN TO ALL RAIN. SOME ADJUSTMENTS WERE ALSO MADE TO CLOUD COVER...WINDS...AND HIGH TEMPS. && .SHORT TERM...TODAY THROUGH SUNDAY NIGHT ISSUED AT 327 AM MST SAT FEB 13 2016 UPPER TROUGH CONTINUES ACROSS THE ERN HALF OF THE CONUS WITH NW FLOW OVER THE NRN PLAINS. A STRONG FAST MOVING SHORTWAVE IS CROSSING THE CASCADES INTO THE NRN ROCKIES ATTM. CANADIAN HIGH PRES IS SITTING ACROSS THE UPPER MIDWEST WITH A STRONG BAROCLINIC ZONE OVER THE CNTRL TO ERN DAKOTAS. WARM AIR ADVECTION HAS BEGUN OVER THE CWA AS THE FRONTAL BOUNDARY SLIDES E/NE. TEMPS AT 800MB HAVE RISEN ABOVE FREEZING ACROSS MOST OF THE CWA...AND WILL DO SO INTO CNTRL SD OVER THE NEXT 3 TO 6 HOURS. TEMPS WILL WARM ABOVE FREEZING TODAY ACROSS NE WY TO MUCH OF WRN SD...HOWEVER FREEZING TEMPS ARE PROGGED ACROSS PTNS OF NW/NCNTRL SD THROUGH MUCH OF TODAY. AS THE SHORTWAVE PUSHES THROUGH THE REGION TODAY...PRECIP WILL DEVELOP ESPECIALLY ACROSS THE NRN HALF OF THE AREA. WARM LOW LEVELS SHOW THIS WILL FALL AS RAIN. CONCERN IS LINGERING SUB-FREEZING TEMPS ACROSS THE NRN PARTS OF THE CWA WILL RESULT IN A PERIOD OF FREEZING RAIN ESPECIALLY THROUGH THE AFTERNOON. WILL KEEP WINTER WEATHER ADVISORY ISSUED YESTERDAY BUT HAVE EXPANDED IT ACROSS HARDING COUNTY WITH THE SREF/HRRR SHOWING PRECIP POTENTIALLY BEGINNING LATE THIS MORNING WHEN SURFACE TEMPS ARE STILL BELOW FREEZING. BEHIND THE SHORTWAVE ...SUB-FREEZING LOW LEVELS WILL QUICKLY PUSH BACK INTO THE REGION ENDING THE THREAT FOR FREEZING RAIN AS IT BECOMES ALL SNOW IN THE AFTERNOON/EVENING. PARTS OF NW/CNTRL SD COULD SEE 1 TO 3 INCHES OF ACCUMULATION BEFORE PRECIP ENDS DURING THE OVERNIGHT HOURS. WITH LOW LEVEL INSTABILITY THAT DEVELOPS...MAY EVEN A FEW LIGHTNING STRIKES. MODELS SHOWING 700-850MB WINDS REACHING 50KT BRIEFLY NEAR THE FRONTAL BOUNDARY WHICH WOULD CREATE A SHORT PERIOD OF STRONG WINDS FOR NOT MORE THAN AN HOUR OR SO. W/NW WINDS WILL CONTINUE ACROSS THE AREA SUNDAY AS LOW PRESSURE SITS EAST OF THE AREA. WARMER TEMPS NEAR THE SURFACE WILL ALLOW HIGHS TO REACH THE UPPER 30S TO UPPER 40S...HOWEVER COOLER 700MB TEMPS WILL RESULT IN INSTABILITY IN THE LOW LEVELS WHICH WILL ALLOW FOR UPSLOPING TO DEVELOP ACROSS THE NRN/WRN BLKHLS. PRECIP WILL BE RAIN EXCEPT SOME SNOW AT THE HIGHEST ELEVATIONS. THIS LIGHT PRECIP WILL LINGER INTO SUNDAY NIGHT. .LONG TERM...MONDAY THROUGH FRIDAY ISSUED AT 327 AM MST SAT FEB 13 2016 EASTERN NOAM TROUGH WILL BREAKDOWN IN THE PERIOD...ALLOWING MEAN RIDGING TO SPREAD EAST INTO CENTRAL NOAM. THIS WILL RESULT IN A TREND TO VERY MILD/DRY CONDS BY MID WEEK AS STAUNCH WAA SPREADS INTO THE NORTHERN PLAINS. BEFORE THIS OCCURS...ANOTHER NW FLOW IMPULSE WILL ADVECT ACROSS THE NORTHERN PLAINS...SUPPORTING RA/SN SHOWERS MON INTO TUE. VERY WARM WEATHER CAN BE EXPECTED BY WED AND ESP THUR. HIGHS ACROSS THE FA THUR LOOK TO APPROACH AND PASS 70 AT SOME LOCATIONS...ESP IN THE LEE OF THE BH WHERE DOWNSLOPING WILL BE IN PLACE AHEAD OF A DEEP SFC CYCLONE THAT WILL ADVECT EAST THROUGH THE REGION SPURRED BY AMPLIFIED ACTIVE FLOW OVER THE EASTERN PAC. THUR-FRI LOW PRESSURE SYSTEM MAY ALSO SUPPORT ANOTHER HIGH WIND EVENT IN THE REGION TOWARD THE END OF THE WORK WEEK GIVEN PROGGED CAA/PRESSURE RISE COUPLET. ACTIVE JET ACROSS THE PAC LOOKS TO SUPPORT MILD ZONAL FLOW THROUGH THE MIDDLE/END OF NEXT WEEK...KEEPING ARCTIC AIR BOTTLED UP IN NORTHERN CANADA AS RIDGING REMAINS CONFINED TO LOWER LATITUDES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY) ISSUED AT 1021 AM MST SAT FEB 13 2016 MVFR/IFR CIGS OVER NORTHWEST INTO CENTRAL SOUTH DAKOTA WILL CONTINUE THROUGH THIS AFTERNOON AND EVENING AS AREA OF SN/FZRA DEVELOPS. THE HEAVIEST PRECIPITATION WILL BE THIS AFTERNOON INTO TONIGHT. FOR NORTHEAST WYOMING INTO SOUTHWEST SOUTH DAKOTA...SHOWERS WILL DEVELOP THIS AFTERNOON/EVENING WITH LCL MVFR CIGS/VSBY. COLD FRONT CROSSES THE AREA LATE AFTERNOON/EVENING WITH A PERIOD OF GUSTY NORTHWEST WINDS. VFR CONDITIONS EXPECTED ACROSS THE AREA SUNDAY MORNING. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 8 PM MST THIS EVENING FOR SDZ001- 002-014. HIGH WIND WARNING UNTIL 8 PM MST THIS EVENING FOR SDZ012-024>031- 072>074. WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ054>058- 071. && $$ UPDATE...26 SHORT TERM...13 LONG TERM...JC AVIATION...7
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
237 PM CST SAT FEB 13 2016 .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 235 PM CST SAT FEB 13 2016 FAIRLY ACTIVE SHORT TERM FORECAST FOR THE AREA AS TWO FEATURES WILL COMBINE TO PRODUCE MODERATE TO OCCASIONALLY HEAVY SNOWFALL OVER THE CWA. THE STRONG SHORTWAVE THAT WILL SLIDE SOUTHEAST ACROSS SOUTHWEST SOUTH DAKOTA IS STILL LOCATED IN CENTRAL MONTANA AT THIS TIME...AND IS LEADING TO A COUPLE AREAS OF PRECIPITATION IN EASTERN MONTANA (ONE ALONG THE WARM FRONT AND ANOTHER TIED TO THE SHORTWAVE AND COLD FRONT). CLOSER TO THE AREA...SEEING PRECIPITATION JUST TO THE WEST OF THE MISSOURI RIVER THAT IS SLOWLY MOVING EAST-SOUTHEAST. THIS PRECIPITATION IS DUE TO THE INITIAL AREA OF MID-LEVEL WARM AIR ADVECTION AHEAD OF THE WARM FRONT STRETCHING SOUTH-SOUTHEAST THROUGH FAR WESTERN SOUTH DAKOTA. WEBCAMS SHOW THAT THE PRECIPITATION TOWARDS HAAKON/STANLEY COUNTIES IS IN THE FORM OF RAIN AND WITH SURFACE TEMPERATURES IN THAT AREA AROUND OR ABOVE FREEZING...DON/T THINK THERE IS TOO MUCH FREEZING RAIN OCCURRING AT THIS POINT. FARTHER NORTH...RAP ANALYSIS SOUNDINGS INDICATE THE WARM NOSE ALOFT WEAKENS WHICH SHOULD TRANSITION THE PRECIP TO SNOW THE FARTHER NORTH YOU HEAD. OVER THE REST OF THE AREA...CLOUDS HAVE BEEN LOWERING WITH THE INCREASING LOW LEVEL MOISTURE AND DEPARTING SURFACE RIDGE. TEMPERATURES ARE STILL FAIRLY COLD OVER NORTHEAST SD...WHERE 2PM TEMPERATURES RANGE FROM THE UPPER SINGLE DIGITS AT K8D3 TO 13 AT KABR AND THEN 17 AT KMBG. MODELS CONTINUING TO STRUGGLE WITH THE TRACK/EVOLUTION OF THE SHORTWAVE IN MONTANA...WHICH LEADS TO SOME UNCERTAINTY IN THE FORECAST SNOWFALL OVER N.C./N.E. SOUTH DAKOTA THIS EVENING INTO THE OVERNIGHT HOURS. LATEST RUNS OF THE RAP AND 12Z GLOBAL MODELS HAVE TRENDED THE TRACK OF THE STRONGEST FORCING A LITTLE FARTHER TO THE SOUTHWEST AND IN SOME CASES ONLY BARELY BRUSHING SOUTHWESTERN SD. WHILE THAT BEST FORCING SLIDES SOUTHWEST OF MUCH OF THE AREA...STILL HAVE SOME SUPPORT FROM THE UPPER TROUGH AND ESPECIALLY FROM THE WARM AIR ADVECTION / ISENTROPIC ASCENT ALONG AND AHEAD OF THAT TROUGH THROUGH THE EARLY OVERNIGHT HOURS. FAIRLY STRONG LIFT WITH THE WAA (AND SEEN IN THE 700MB OMEGA) WITH FAVORABLE 850-500MB Q-VECTOR DIVERGENCE. THEREFORE...EXPECT TO SEE A FAIRLY QUICK HITTING (4-7HR PERIOD) AREA OF PRECIPITATION MOVING THROUGH THE AREA...ESPECIALLY THIS EVENING INTO THE EARLY OVERNIGHT HOURS. MODELS HAVE TRENDED QPF AMOUNTS TO THE NORTH WITH THE MOST RECENT RUNS...SOME EVEN SHOWING 12HR QPF AMOUNTS EXCEEDING 0.6IN BETWEEN MOBRIDGE/ABERDEEN. THAT POTENTIAL (LIKELY SOMEWHAT CONVECTIVELY DRIVEN WITH 750-500MB LAPSE RATES AROUND 7 C/KM) WILL NEED TO BE WATCHED THROUGH THE EVENING AND IF IT SETS UP AS SHOWN WITH SOME OF THE HIGHER RES RUNS...MAY NEED TO UPGRADE A FEW COUNTIES TO WARNINGS. WITH THAT FARTHER NORTH TREND...EXPECT A LITTLE LESS IMPACT FOR THE SOUTHWESTERN CWA...BUT STILL THINK THE POTENTIAL FOR FREEZING RAIN THROUGH THE FIRST PART OF THE EVENING BEFORE TRANSITIONING TO SNOW FOR A BRIEF PERIOD BEFORE ENDING. THAT NORTHWARD SHIFT SHOULD KEEP SNOWFALL AMOUNTS BELOW 2 INCHES FROM PIERRE AND SOUTHWEST (WHERE SOME AREAS WILL STAY MAINLY RAIN). AS FOR SNOWFALL AMOUNTS OVER THE NORTH CENTRAL AND NORTHEAST...HAVE A GENERAL 3-6 INCHES WITH SNOW RATIOS INCREASING FROM AROUND 10-1 AROUND THE MISSOURI RIVER TO THE 12-14 TO 1 RANGE OVER THE NORTHEAST. OVER THE NORTHEAST...A GOOD PORTION OF THE LIFT IS AT OR ABOVE THE DGZ...WHICH WILL LIKELY LEAD TO MORE COLUMNS IN THE SNOW PROCESS AND MORE POTENTIAL FOR COMPACTING (ALONG WITH AGGREGATION AS THE SNOW FALLS THROUGH THE CLOUD LAYER BELOW THE DGZ). THUS...DIDN/T WANT TO GO MUCH HIGHER THAN THE PREVIOUSLY MENTIONED VALUES ...ALTHOUGH RATIOS COULD BRIEFLY INCREASE IF THE FORCING ALIGNS A LITTLE LOWER AND IN THE DGZ. WITH THE HIGHER QPF AND RATIOS...HAVE NEAR WARNING SNOWFALL AMOUNTS (5.5-6IN) OVER MCPHERSON/EDMUNDS/BROWN/MARSHALL/DAY COUNTIES. WITH THE VARIABILITY IN THE MODEL RUNS TODAY...DIDN/T HAVE ENOUGH CONFIDENCE TO UPGRADE TO A WARNING AT THIS POINT AND THE EVENING SHIFT WILL NEED TO MONITOR FOR A POSSIBLE UPGRADE. IN ADDITION...WITH THE SNOW OCCURRING LATE THIS EVENING AND DURING THE EARLY OVERNIGHT HOURS...THOUGHT THE IMPACTS WOULD BE LOWER THAN IF IT OCCURRED DURING THE DAY. ONE OTHER ITEM TO MENTION WILL BE THE GUSTY SOUTH-SOUTHEAST WINDS INITIALLY THIS EVENING AHEAD OF THE TROUGH (GUSTS TO 25-30MPH). THAT WILL LEAD TO PATCHY/AREAS OF BLOWING SNOW AND WILL CONTINUE TO MENTION THAT IN THE FORECAST/WSW. FOR THE REST OF THE PERIOD...THE SNOW WILL DIMINISH FROM WEST TO EAST LATE TONIGHT AND THROUGH THE DAY ON SUNDAY (LARGELY OVER THE EASTERN HALF/THIRD OF THE CWA). A BROAD SURFACE TROUGH WILL BE OVER THE AREA AND LIMIT THE WINDS AND IN TURN ANY BLOWING SNOW CONCERNS. IN ADDITION...WITH THE WARM AIR OVER THE AREA BEHIND THE WARM FRONT THAT MOVED THROUGH...HIGHS WILL RISE INTO THE MID/UPPER 20S OVER THE FAR EAST TO THE LOWER 40S ALONG AND WEST OF THE MISSOURI RIVER. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 235 PM CST SAT FEB 13 2016 LOW TEMP FORECAST FOR SUNDAY NIGHT IS A BIT TRICKY. AREA WILL STILL BE IN A RELATIVELY MILD AIR MASS WITH 925MB TEMPS AROUND 0C TO +2C AND A LIGHT WEST TO SOUTHWEST SFC WIND. ALTHOUGH...WILL HAVE TO KEEP IN MIND THE FRESH COAT OF SNOW THAT WILL BE OVER MUCH OF THE AREA. THERE WILL BE SOME DEGREE OF CLOUD COVER AS WELL...SO TRYING TO FIGURE OUT WHICH VARIABLES HAVE THE BIGGEST IMPACT ON TEMPS IS TRICKY. WILL THEN BE WATCHING THE NEXT PIECE OF SHORTWAVE ENERGY WHICH WILL BE DROPPING SOUTHEAST THROUGH THE AREA MONDAY NIGHT. HAVE INCREASED POPS FOR THIS EVENT AS MODELS ARE IN PRETTY GOOD AGREEMENT ON TIMING AND PLACEMENT OF QPF. AGAIN...COULD BE DEALING WITH MIXED PRECIP ISSUES AS THERE WILL BE WARM AIR IN PLACE. YET ANOTHER WAVE MOVES THROUGH TUESDAY NIGHT BUT IS LOOKING RATHER WEAK AT THIS POINT. SUPERBLEND GAVE SLIGHT CHANCE POPS AND THIS LOOKS GOOD FOR THE TIME BEING. ONLY CHANGE HERE WAS TO REMOVE THE SLIGHT CHANCES THEY INITIAL GAVE ON TUESDAY AND HELD THINGS OFF TO TUESDAY NIGHT PER MODEL DATA. TEMPS THROUGHOUT THE PERIOD STAY ON THE MILD SIDE...ESPECIALLY BY THURSDAY WHEN MODELS TRY TO BRING IN SOME VERY MILD AIR. 925MB TEMPS AROUND +20C SHOW UP IN THE MODELS OVER SOUTHWEST AND SOUTH CENTRAL SD. SUPERBLEND TEMPS HAVE READINGS AS WARM AS THE 60S OVER THE SOUTHWEST CWA ON THURSDAY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON) ISSUED AT 1149 AM CST SAT FEB 13 2016 EXPECT DETERIORATING CONDITIONS FROM WEST TO EAST THROUGH THE AFTERNOON AND EVENING ACROSS THE REGION...AS A STORM SYSTEM SLIDES EAST-SOUTHEAST ACROSS THE AREA. HAVE ALREADY STARTED TO SEE SOME REDUCTIONS IN VISIBILITY AT KMBG AND EXPECT VISIBILITIES TO FALL TO LOW END IFR AT ALL THE SITES AS THE HEAVIEST SNOW MOVES THROUGH. COULD BRIEFLY SEE LIFR VISIBILITIES FIRST OVER THE WEST LATE THIS AFTERNOON THROUGH LATE EVENING AND THEN AT KABR/KATY BETWEEN 02-08Z (COMBINATION OF THE HEAVY SNOW AND BLOWING SNOW BEFORE WINDS DIMINISH). EXPECT VISIBILITIES TO RAPIDLY IMPROVE OVER THE WEST AFTER MIDNIGHT AS THE SYSTEM SHIFTS TO THE EAST (VFR CONDITIONS WEST BY MID MORNING)...ALTHOUGH MVFR CONDITIONS WILL PREVAIL THROUGH SUNDAY MORNING OVER THE EAST. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...WINTER WEATHER ADVISORY UNTIL 6 AM CST /5 AM MST/ SUNDAY FOR SDZ003- 004-009-015-016-033>036-045-048-051. WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY FOR SDZ005>008-010-011-017>023-037. MN...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST SUNDAY FOR MNZ039-046. && $$ SHORT TERM...SRF LONG TERM...TDK AVIATION...SRF
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
935 PM CST SUN FEB 14 2016 .UPDATE... MESOSCALE UPDATE. && .DISCUSSION... INTERESTING EVOLUTION OF WINTER WEATHER EVENT HAS OCCURRED THIS EVENING AS SURFACE FREEZING LINE HAS SAGGED BACK SOUTHWARD TO NEAR THE I-40 CORRIDOR. THIS APPEARS TO HAVE BEEN DUE TO A WEAK WAVE MOVING NORTHEASTWARD ALONG THE INVERTED TROUGH IN PLACE FROM SW TO NE ACROSS THE CWA. 02Z HRRR AND 00Z NAM INSIST FREEZING LINE WILL RETURN BACK NORTHWARD THIS EVENING/OVERNIGHT...AND THIS APPEARS TO BE UNDERWAY AS TEMPERATURES HAVE RISEN INTO THE LOW 30S AT CKV AND INTO SOUTHERN KY. HOWEVER...LIGHT SLEET/FZRA WILL CONTINUE FOR ANOTHER HOUR OR TWO FOR THE I-40 CORRIDOR COUNTIES...AND LIKELY LINGER PAST MIDNIGHT FOR THE KY BORDER COUNTIES WHERE TRAVEL IMPACTS REMAIN SIGNIFICANT. THUS HAVE EXTENDED THE WWA UNTIL 12Z FOR THE NORTHWESTERN COUNTIES AS TRAVEL WILL REMAIN HAZARDOUS THERE THROUGH THE OVERNIGHT HOURS. ALTHOUGH MOST OBS ARE WELL ABOVE FREEZING IN THE CENTRAL PLATEAU COUNTIES...KEPT THE ADVISORY GOING FOR PUTNAM/WHITE/CUMBERLAND/VAN BUREN AS SOME AREAS REMAIN BELOW FREEZING...MAINLY THE HIGHER ELEVATIONS. UPDATED PRODUCTS OUT SHORTLY. && .AVIATION... 00Z TAF DISCUSSION. POOR FLYING WEATHER NEXT 24 HOURS IN MIDDLE TENNESSEE AND ADJACENT AREAS DUE TO LOW CEILINGS AND VISIBILITIES. FREEZING RAIN WILL CONTINUE AT CLARKSVILLE FOR THE NEXT HOUR OR TWO BEFORE CHANGING TO RAIN. RAIN NOW FALLING AT NASHVILLE. TEMPERATURES WILL SLOWLY RISE OVERNIGHT TO AROUND 40 DEGREES BY DAYBREAK MONDAY MOST AREAS. SURFACE LOW CENTRAL TEXAS WITH INVERTED TROUGH NORTHEAST THROUGH SOUTHERN ARKANSAS...CENTRAL TENNESSEE INTO THE WEST VIRGINIA WILL REMAIN INSITU NEXT 24 HOURS WHILE ACTING AS THE FOCUS FOR RAIN...SOME HEAVY AT TIMES. && .OHX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CLAY- CUMBERLAND-FENTRESS-JACKSON-MACON-MONTGOMERY-OVERTON-PICKETT- PUTNAM-ROBERTSON-STEWART-SUMNER-VAN BUREN-WHITE. && $$ AVIATION.........................01/BOYD SHORT/LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
850 PM CST SUN FEB 14 2016 .UPDATE... MAIN CHALLENGE IN THE OVERNIGHT PERIOD IS ONCE AGAIN THE POTENTIAL FOR FOG OVERNIGHT AND TOMORROW MORNING. A WEAK FRONT WILL BE APPROACHING THE REGION OVERNIGHT AND WE SHOULD SEE WINDS GO LIGHT AND VARIABLE AHEAD OF THE BOUNDARY. THIS SHOULD ALLOW FOR MOISTURE TO POOL AND FOR FOG PRODUCTION TO OCCUR. THE BEST LOCATION FOR THIS TO HAPPEN IS AREAS NEAR BEXAR COUNTY AND TO THE WEST. FARTHER EAST...SOUTHWEST WINDS WILL PREVAIL WHICH SHOULD KEEP MOST OF THE FOG AT BAY. UPPED THE WORDING TO AREAS OF FOG FOR THE CENTRAL PORTIONS OF THE CWA AS THE HRRR IS SHOWING SOME POSSIBLE DENSE FOG. && .PREV DISCUSSION... /ISSUED 550 PM CST SUN FEB 14 2016/ AVIATION DISCUSSION...FOR 00Z TAF PERIOD... SOUTHERLY WINDS WILL CONTINUE TO BRING MOISTURE INTO THE AREA TONIGHT WHICH WILL RESULT IN LOW CIG DEVELOPMENT OVERNIGHT IN ADVANCE OF AN APPROACHING COLD FRONT TOMORROW MORNING. EXPECTING IFR AT LEAST FOR THE I35 TERMINALS SHORTLY AFTER MIDNIGHT WITH KSAT/KSSF FALLING TO LIFR. THESE CONDITIONS WILL LIKELY PERSIST UNTIL THE FRONTAL PASSAGE WHICH IS FORECAST TO MOVE THROUGH KAUS AROUND 14Z AND KSAT/KSSF BY 16Z. THEN VFR IS EXPECTED WITH GUSTY WINDS OF 10-15 KTS GUSTING TO 20-25 DURING THE AFTERNOON. PREV DISCUSSION... /ISSUED 233 PM CST SUN FEB 14 2016/ SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)... UPPER AIR ANALYSIS THIS MORNING SHOWED ZONAL FLOW ACROSS MOST OF THE SOUTHERN PART OF THE COUNTRY WITH A RIDGE OFF THE WEST COAST. AT THE SURFACE...WINDS WERE FROM THE SOUTH AHEAD OF A COLD FRONT THAT WAS STRETCHED ACROSS WEST TEXAS. A SHALLOW UPPER LEVEL TROUGH WILL DEVELOP TONIGHT AND MOVE ACROSS TEXAS AND BRING NORTHWESTERLY FLOW TOMORROW. THIS WILL BRING THE COLD FRONT THROUGH BY NOON TUESDAY. THERE IS LIMITED MOISTURE AVAILABLE TO THIS SYSTEM...SO ONLY SLIGHT CHANCE FOR DRIZZLE ACROSS THE EASTERN COUNTIES. FOG IS LIKELY ACROSS THE SOUTH AND EAST MONDAY MORNING. THE FRONT WILL USHER IN NORTHERLY WINDS AND DRIER AIR. LONG TERM (TUESDAY THROUGH SUNDAY)... TUESDAY AND WEDNESDAY TEXAS WILL LIE BETWEEN AN UPPER LEVEL TROUGH DIGGING OVER THE EAST AND A RIDGE BUILDING OVER THE WEST. THIS WILL KEEP THE UPPER FLOW NORTHWESTERLY. DURING THIS TIME AT THE SURFACE HIGH PRESSURE WILL MOVE ACROSS OUR CWA SWITCHING THE WINDS AROUND TO THE SOUTH BY WEDNESDAY. THIS WILL CONTINUE DRY WEATHER. THE UPPER PATTERN WILL BECOME PROGRESSIVE WEDNESDAY NIGHT AND THE RIDGE WILL MOVE ACROSS TEXAS THURSDAY. MOST OF THE SECOND HALF OF THE WEEK WILL CONTINUE TO BE DRY...BUT BY SATURDAY THERE MAY BE DEEP ENOUGH MOISTURE AND SUFFICIENT ISENTROPIC LIFT TO PRODUCE LIGHT RAIN. SUNDAY A COLD FRONT WILL APPROACH OUR CWA FROM THE NORTH AND THERE WILL BE A CHANCE FOR SHOWERS AND POSSIBLY SOME THUNDERSTORMS. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 56 76 49 80 51 / 10 - 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 53 75 44 78 46 / 10 - 0 0 0 NEW BRAUNFELS MUNI AIRPORT 53 78 47 80 49 / 10 - 0 0 0 BURNET MUNI AIRPORT 50 73 45 78 48 / - 0 0 0 0 DEL RIO INTL AIRPORT 48 81 48 82 51 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 53 73 45 78 47 / 10 0 0 0 0 HONDO MUNI AIRPORT 48 80 45 80 48 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 53 76 46 78 48 / 10 - 0 0 0 LA GRANGE - FAYETTE REGIONAL 56 76 47 79 49 / 10 10 0 0 0 SAN ANTONIO INTL AIRPORT 53 77 48 79 51 / - - 0 0 0 STINSON MUNI AIRPORT 53 79 48 80 50 / - - 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...TB3 SYNOPTIC/GRIDS...HAMPSHIRE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
754 PM CST SUN FEB 14 2016 .UPDATE... A LOOSELY ORGANIZED FRONTAL ZONE CURRENTLY STRETCHES WEST-TO EAST ACROSS THE ARKLATEX REGION WITH A LIGHT AND DISORGANIZED WIND FIELD ASSOCIATED WITH IT. THE BOUNDARY WILL BECOME MORE ORGANIZED OVER THE NEXT SEVERAL HOURS AS A SHORTWAVE OVER WEST-CENTRAL TEXAS CROSSES OVERHEAD. LIFT FROM THE SHORTWAVE AND PERHAPS SOME ADDED FRONTOGENETIC FORCING SHOULD LEAD TO SHOWER AND ISOLATED THUNDERSTORM DEVELOPMENT DURING THE LATE EVENING AND OVERNIGHT HOURS...MAINLY FOR AREAS ALONG AND EAST OF THE I-35 CORRIDOR. SHOWERS WILL LINGER INTO THE MORNING BEFORE MOVING QUICKLY EAST OF THE REGION AS THE SHORTWAVE HEADS FOR THE MISSISSIPPI VALLEY. SLIGHT ADJUSTMENT TO THE POP GRIDS WERE MADE TO ACCOUNT FOR THE LATEST HIGH-RES GUIDANCE ADVERTISING BEST OVERALL RAIN CHANCES IN THE NORTHEASTERN-MOST COUNTIES. OTHERWISE ONLY MINOR GRID ADJUSTMENTS HAVE BEEN MADE. 30 && .AVIATION... /ISSUED 602 PM CST SUN FEB 14 2016/ /00Z TAFS/ A COLD FRONT IS CURRENTLY APPROACHING THE RED RIVER VALLEY AND NW COUNTIES WITH WINDS ACROSS THE DFW AREA AIRPORTS GENERALLY VARIABLE 5 KTS OR LESS...WITH SSW WINDS AT WACO STILL AROUND 10 KTS. TIMING THE COLD FRONT AND SWITCH TO NORTH FLOW A LITTLE TRICKY...AS ARE CIG FORECASTS. FOR NOW...WILL PEG A 04Z-05Z TIME FRAME FOR DFW AREA AIRPORTS WITH A WEAK WIND SHIFT TO THE NNE 5-10 KTS AT FIRST...THEN AS THE FRONTAL INVERSION DEEPENS...GOING NNW OR NW 10-15 KTS OVERNIGHT. WACO WILL LIKELY STAY SOUTH FLOW ALL NIGHT WITH INITIAL FROPA MORE TOWARD 12Z SINCE IT WILL BE SLOW TO MOVE UNTIL THE SHORTWAVE ALOFT CATCHES UP AND HELPS PUSH THE FRONT ALONG FASTER TOWARD SUNRISE MONDAY WITH NW WINDS 15 KTS THROUGH THE DAY WITH OCCASIONAL GUSTS TO 20 KTS POSSIBLE...BEFORE DECOUPLING TOWARD 00Z TUESDAY. AS FOR CIGS AND FLIGHT RULES...THE INITIAL FROPA WILL BE VERY SHALLOW WITH LOW MVFR/HIGH IFR CONDITIONS THROUGH THE OVERNIGHT HOURS FOR DFW AREA AIRPORTS. AS THE CAA INCREASES AND THE FRONTAL PUSH INCREASES WITH THE SHORTWAVE PASSING THROUGH...CIGS WILL RISE BACK INTO HIGH MVFR LATER IN THE MORNING THEN BECOME VFR BY 18Z AND AFTER. THE ONE CAVEAT HERE IS NOTHING IS SEEN UPSTREAM AS FAR AS CIGS QUITE THIS LOW AND THEY WOULD NEED TO BACK BUILD WSW IN BEHIND THE INITIAL SHALLOW FRONTAL PUSH. THE NAM12 AND RUC OPS40 SOUNDINGS SHOW THIS WELL...THOUGH THE GFS BUFR SOUNDINGS DISAGREE. PER COORDINATION WITH OUR PARTNERS AT THE ZFW CWSU...I HAVE LEFT OUT VCSH/VCTS WORDING WITH THE FROPA AFTER 03Z AT THIS TIME WITH ONLY ISOLATED CHANCES EXPECTED AT AIRPORTS. IT DEFINITELY BEARS WATCHING HOWEVER. WACO WILL HAVE SIMILAR TRENDS...JUST DELAYED 3-6 HRS. IN A NUTSHELL...THE EVOLUTION OF CIGS AND CONVECTION IS NOT CLEAR CUT WITH THE MODELS STRUGGLING AND DISAGREEING. WILL WATCH AND AMEND AS CONDITIONS DEVELOP LATER TONIGHT AND DEVELOPMENT OF ALL VARIABLES BECOMES MORE EVIDENT. 05/ && .PREV DISCUSSION... /ISSUED 246 PM CST SUN FEB 14 2016/ LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS MUCH OF NORTH TEXAS THROUGH THE EVENING AHEAD OF AN APPROACHING COLD FRONT. AS OF 2 PM THE FRONT HAD ALREADY REACHED THE WESTERN ZONES BUT SHOULD NOT MOVE FARTHER EAST UNTIL THE PASSAGE OF A FAST MOVING SHORTWAVE. MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REMAIN NEAR THE RED RIVER TONIGHT AND THE BEST RAIN CHANCES WILL RESIDE GENERALLY EAST OF INTERSTATE 35 AND NORTH OF INTERSTATE 20. MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO SUPPORT AT LEAST ISOLATED THUNDERSTORMS (700 TO 500 MB DELTA T ON THE ORDER OF 17 TO 19 DEGREES C). RAIN CHANCES WILL END QUICKLY MONDAY MORNING ONCE THE SHORTWAVE TROUGH AXIS MOVES EAST AND DRIER AIR FILTERS IN BEHIND THE COLD FRONT. TEMPERATURES MONDAY WILL STILL BE MILD FOR MID FEBRUARY DUE TO ABUNDANT SUN AND ONLY WEAK COLD AIR ADVECTION. HIGHS MONDAY AFTERNOON WILL RANGE FROM THE MIDDLE 60S TO THE LOWER 70S. UPPER LEVEL HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY THROUGH THURSDAY AND RESULT IN WARM TEMPERATURES AND LITTLE CHANCE FOR RAIN. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S TO LOWER 80S WITH LOWS IN THE 40S AND 50S. THE UPPER RIDGE WILL BUILD TOWARD THE EAST COAST THURSDAY NIGHT/FRIDAY WHILE A SHORTWAVE MOVES FROM THE ROCKIES TO THE CENTRAL PLAINS. ALTHOUGH CLOUD COVER WILL INCREASE ON FRIDAY IN RESPONSE TO A SURGE IN LOW LEVEL MOISTURE...TEMPERATURES WILL STILL BE IN THE 70S AND LOWER 80S FRIDAY AFTERNOON. THE UPPER PATTERN WILL BECOME ZONAL LATE IN THE WEEKEND THROUGH EARLY NEXT WEEK WITH A SHORTWAVE PROGGED TO MOVE QUICKLY ACROSS THE STATE SATURDAY NIGHT/SUNDAY. AS A RESULT...SOME RAIN/STORM CHANCES WILL RETURN TO THE REGION. WILL LEAVE POPS LOW FOR NOW DUE TO TIMING UNCERTAINTIES WITH THE SHORTWAVE AND THE ASSOCIATED COLD FRONT. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 53 69 46 73 46 / 30 10 0 0 0 WACO, TX 51 71 42 76 43 / 30 10 0 0 0 PARIS, TX 49 65 42 69 40 / 50 30 5 0 0 DENTON, TX 46 67 44 72 42 / 30 10 0 0 0 MCKINNEY, TX 50 65 41 71 42 / 40 20 0 0 0 DALLAS, TX 53 70 48 74 46 / 30 10 0 0 0 TERRELL, TX 54 68 41 72 43 / 40 30 5 0 0 CORSICANA, TX 57 69 46 74 46 / 30 30 0 0 0 TEMPLE, TX 53 72 45 78 45 / 20 10 0 0 0 MINERAL WELLS, TX 45 68 40 75 43 / 10 10 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
602 PM CST SUN FEB 14 2016 .AVIATION... /00Z TAFS/ A COLD FRONT IS CURRENTLY APPROACHING THE RED RIVER VALLEY AND NW COUNTIES WITH WINDS ACROSS THE DFW AREA AIRPORTS GENERALLY VARIABLE 5 KTS OR LESS...WITH SSW WINDS AT WACO STILL AROUND 10 KTS. TIMING THE COLD FRONT AND SWITCH TO NORTH FLOW A LITTLE TRICKY...AS ARE CIG FORECASTS. FOR NOW...WILL PEG A 04Z-05Z TIME FRAME FOR DFW AREA AIRPORTS WITH A WEAK WIND SHIFT TO THE NNE 5-10 KTS AT FIRST...THEN AS THE FRONTAL INVERSION DEEPENS...GOING NNW OR NW 10-15 KTS OVERNIGHT. WACO WILL LIKELY STAY SOUTH FLOW ALL NIGHT WITH INITIAL FROPA MORE TOWARD 12Z SINCE IT WILL BE SLOW TO MOVE UNTIL THE SHORTWAVE ALOFT CATCHES UP AND HELPS PUSH THE FRONT ALONG FASTER TOWARD SUNRISE MONDAY WITH NW WINDS 15 KTS THROUGH THE DAY WITH OCCASIONAL GUSTS TO 20 KTS POSSIBLE...BEFORE DECOUPLING TOWARD 00Z TUESDAY. AS FOR CIGS AND FLIGHT RULES...THE INITIAL FROPA WILL BE VERY SHALLOW WITH LOW MVFR/HIGH IFR CONDITIONS THROUGH THE OVERNIGHT HOURS FOR DFW AREA AIRPORTS. AS THE CAA INCREASES AND THE FRONTAL PUSH INCREASES WITH THE SHORTWAVE PASSING THROUGH...CIGS WILL RISE BACK INTO HIGH MVFR LATER IN THE MORNING THEN BECOME VFR BY 18Z AND AFTER. THE ONE CAVEAT HERE IS NOTHING IS SEEN UPSTREAM AS FAR AS CIGS QUITE THIS LOW AND THEY WOULD NEED TO BACK BUILD WSW IN BEHIND THE INITIAL SHALLOW FRONTAL PUSH. THE NAM12 AND RUC OPS40 SOUNDINGS SHOW THIS WELL...THOUGH THE GFS BUFR SOUNDINGS DISAGREE. PER COORDINATION WITH OUR PARTNERS AT THE ZFW CWSU...I HAVE LEFT OUT VCSH/VCTS WORDING WITH THE FROPA AFTER 03Z AT THIS TIME WITH ONLY ISOLATED CHANCES EXPECTED AT AIRPORTS. IT DEFINITELY BEARS WATCHING HOWEVER. WACO WILL HAVE SIMILAR TRENDS...JUST DELAYED 3-6 HRS. IN A NUTSHELL...THE EVOLUTION OF CIGS AND CONVECTION IS NOT CLEAR CUT WITH THE MODELS STRUGGLING AND DISAGREEING. WILL WATCH AND AMEND AS CONDITIONS DEVELOP LATER TONIGHT AND DEVELOPMENT OF ALL VARIABLES BECOMES MORE EVIDENT. 05/ && .PREV DISCUSSION... /ISSUED 246 PM CST SUN FEB 14 2016/ LOW LEVEL WARM AIR ADVECTION WILL CONTINUE ACROSS MUCH OF NORTH TEXAS THROUGH THE EVENING AHEAD OF AN APPROACHING COLD FRONT. AS OF 2 PM THE FRONT HAD ALREADY REACHED THE WESTERN ZONES BUT SHOULD NOT MOVE FARTHER EAST UNTIL THE PASSAGE OF A FAST MOVING SHORTWAVE. MOST OF THE ENERGY ASSOCIATED WITH THE SHORTWAVE WILL REMAIN NEAR THE RED RIVER TONIGHT AND THE BEST RAIN CHANCES WILL RESIDE GENERALLY EAST OF INTERSTATE 35 AND NORTH OF INTERSTATE 20. MID LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO SUPPORT AT LEAST ISOLATED THUNDERSTORMS (700 TO 500 MB DELTA T ON THE ORDER OF 17 TO 19 DEGREES C). RAIN CHANCES WILL END QUICKLY MONDAY MORNING ONCE THE SHORTWAVE TROUGH AXIS MOVES EAST AND DRIER AIR FILTERS IN BEHIND THE COLD FRONT. TEMPERATURES MONDAY WILL STILL BE MILD FOR MID FEBRUARY DUE TO ABUNDANT SUN AND ONLY WEAK COLD AIR ADVECTION. HIGHS MONDAY AFTERNOON WILL RANGE FROM THE MIDDLE 60S TO THE LOWER 70S. UPPER LEVEL HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY THROUGH THURSDAY AND RESULT IN WARM TEMPERATURES AND LITTLE CHANCE FOR RAIN. HIGHS TUESDAY THROUGH THURSDAY WILL BE IN THE 70S TO LOWER 80S WITH LOWS IN THE 40S AND 50S. THE UPPER RIDGE WILL BUILD TOWARD THE EAST COAST THURSDAY NIGHT/FRIDAY WHILE A SHORTWAVE MOVES FROM THE ROCKIES TO THE CENTRAL PLAINS. ALTHOUGH CLOUD COVER WILL INCREASE ON FRIDAY IN RESPONSE TO A SURGE IN LOW LEVEL MOISTURE...TEMPERATURES WILL STILL BE IN THE 70S AND LOWER 80S FRIDAY AFTERNOON. THE UPPER PATTERN WILL BECOME ZONAL LATE IN THE WEEKEND THROUGH EARLY NEXT WEEK WITH A SHORTWAVE PROGGED TO MOVE QUICKLY ACROSS THE STATE SATURDAY NIGHT/SUNDAY. AS A RESULT...SOME RAIN/STORM CHANCES WILL RETURN TO THE REGION. WILL LEAVE POPS LOW FOR NOW DUE TO TIMING UNCERTAINTIES WITH THE SHORTWAVE AND THE ASSOCIATED COLD FRONT. 79 && .PRELIMINARY POINT TEMPS/POPS... DALLAS-FT. WORTH, TX 53 69 46 73 46 / 30 10 0 0 0 WACO, TX 51 71 42 76 43 / 30 10 0 0 0 PARIS, TX 49 65 42 69 40 / 50 30 5 0 0 DENTON, TX 46 67 44 72 42 / 30 10 0 0 0 MCKINNEY, TX 50 65 41 71 42 / 40 20 0 0 0 DALLAS, TX 53 70 48 74 46 / 30 10 0 0 0 TERRELL, TX 54 68 41 72 43 / 40 30 5 0 0 CORSICANA, TX 57 69 46 74 46 / 30 30 0 0 0 TEMPLE, TX 53 72 45 78 45 / 20 10 0 0 0 MINERAL WELLS, TX 45 68 40 75 43 / 10 10 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 05/79
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1220 PM CST SAT FEB 13 2016 .AVIATION... MVFR CIGS NOTED ACROSS THE SWRN TWO THIRDS OF THE CWFA THIS MORN/ AFTN...GENERALLY ALONG AND SOUTH OF THE WEAK FRONTAL BOUNDARY. AS THE LINE WEAKENS/MOVES BACK FURTHER INLAND THIS EVENING/OVERNIGHT WE COULD SEE WIDESPREAD LOWER/MVFR CIGS ACROSS SE TX BY SAT MORN. SOME SPOTS MIGHT SEE PATCHY FOG OVERNIGHT AS WELL...BUT FOG COULD BE MORE PREVALENT SUN MORN. 41 && .PREV DISCUSSION... /ISSUED 925 AM CST SAT FEB 13 2016/ UPDATE... FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET DENSE FOG ADVISORY EXPIRE. BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF CHANGE FROM THE PREVIOUS UPDATE. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20 HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30 GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...99 AVIATION/MARINE...41
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
925 AM CST SAT FEB 13 2016 .UPDATE... FIRST VISIBILITY HAS IMPROVED SOUTH OF A FRONTAL BOUNDARY SO LET DENSE FOG ADVISORY EXPIRE. BASED ON 15Z SFC OBS...FRONTAL BOUNDARY LOCATED FROM LA GRANGE TO SUGAR LAND TO GALVESTON. LATEST 14Z HRRR HAS THIS BOUNDARY FAIRLY WELL RESOLVED AND BEGINS TO PUSH THE BOUNDARY BACK NORTH LATER THIS AFTERNOON AND TURNS WINDS TO SE. THERE MAY BE ENOUGH CLOUD COVER AND COOLER AIR TO KEEP MAX TEMPS IN THE 60S BUT MAY STILL FEEL HUMID WITH DEWPOINTS IN THE 50S SOUTH OF THE BOUNDARY. MAIN UPDATES TO THE FORECAST WERE TO ENSURE CONSISTENCY WITH ONGOING TRENDS AND LATEST SHORT RANGE GUIDANCE. OVERALL NOT A LOT OF CHANGE FROM THE PREVIOUS UPDATE. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 67 52 71 56 71 / 10 10 20 20 20 HOUSTON (IAH) 68 51 71 58 72 / 10 10 20 30 30 GALVESTON (GLS) 61 56 69 58 68 / 10 10 20 20 30 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1041 PM CST FRI FEB 12 2016 .DISCUSSION...SEE AVIATION SECTION FOR 06Z TAFS. && .AVIATION...HIGHER BOUNDARY LAYER MOISTURE IS OVER THE COASTAL PLAINS INTO THE EASTERN BRUSH COUNTRY LATE THIS EVENING WHILE WINDS DIMINISHED. TEMPERATURE/DEWPOINT DEPRESSIONS ARE NEAR ZERO OVER THE VICTORIA CROSSROADS. FOG/MVFR VSBYS EXPECTED TO DEVELOP 05-06Z IN THIS REGION WITH CONDITIONS DETERIORATING TO LIFR WITH DENSE FOG BY 07-08Z AND CONTINUE UNTIL AROUND 15Z. TIMING FOR FOG IN THE ALI/CRP AREA WILL BE DELAYED AN HOUR OR TWO WITH LIFR CONDS FORMING BY 08-09Z. EXPECT THE LOW CLOUDS AND FOG...IFR CIGS AND MVFR VSBYS...WILL REACH LRD AREA BY 11Z WITH LIFR VSBYS POSSIBLE IN NEAR DENSE FOG. VSBYS ARE EXPECTED TO IMPROVE BY 15-16Z TO VFR WITH MVFR CIGS HOLDING OVER VCT AREA THROUGH THE LATE MORNING BEFORE LIFTING. STRATUS IS EXPECTED TO MOVE BACK INTO THE VCT AREA AROUND 03Z SUNDAY. && .PREV DISCUSSION... /ISSUED 914 PM CST FRI FEB 12 2016/ DISCUSSION...DEWPOINT TEMPERATURES HAVE RISEN TO THE UPPER 50S TO NEAR 60 OVER THE COASTAL PLAINS THIS EVENING. WINDS WILL CONTINUE TO DIMINISH TONIGHT AS A WEAK FRONTAL BOUNDARY FROM NORTH OF HOUSTON TO SOUTH OF SAN ANTONIO REMAINS ESSENTIAL QUASISTATIONARY TONIGHT. TEMP-DEWPOINT DEPRESSIONS WERE THE LOWEST AROUND THE MID COAST AT 03Z. 00Z HRRR ALONG WITH 00Z NAM SHOW FOG WILL FORM OVER THE MID COAST REGION INITIALLY JUST AFTER 06Z AND SPREAD WESTWARD INTO THE BRUSH COUNTRY OVERNIGHT. ADDED CALHOUN AND ARANSAS COUNTIES INTO THE DENSE FOG ADVISORY. MAY NEED TO HAVE ADVISORY FOR WEBB AND LA SALLE COUNTIES LATER TONIGHT BUT NOT CONFIDENT ENOUGH AT THIS POINT TO INCLUDE IN THE ADVISORY. && .PRELIMINARY POINT TEMPS/POPS... CORPUS CHRISTI 55 74 57 78 56 / 0 10 10 10 0 VICTORIA 50 71 54 75 57 / 0 10 10 10 10 LAREDO 54 82 55 83 53 / 0 0 0 0 0 ALICE 52 78 54 82 55 / 0 0 10 10 0 ROCKPORT 56 70 60 73 60 / 0 10 10 10 10 COTULLA 50 80 54 83 51 / 0 0 0 0 0 KINGSVILLE 52 77 54 78 56 / 0 0 0 10 10 NAVY CORPUS 56 71 60 73 59 / 0 10 10 10 10 && .CRP WATCHES/WARNINGS/ADVISORIES... TX...DENSE FOG ADVISORY FROM 2 AM TO 10 AM CST SATURDAY FOR THE FOLLOWING ZONES: ARANSAS...BEE...CALHOUN...DUVAL...GOLIAD... JIM WELLS...KLEBERG...LIVE OAK...MCMULLEN...NUECES... REFUGIO...SAN PATRICIO...VICTORIA. GM...NONE. && $$ TMT/89...AVIATION
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1013 PM MST FRI FEB 12 2016 .UPDATE... ISSUED AT 1010 PM MST FRI FEB 12 2016 WEBCAMS NEAR CARPENTER IN EASTERN LARAMIE COUNTY...ALONG WITH DECREASING VISIBILITIES REPORTED AT PINE BLUFFS...LED ME TO EXPAND THE DENSE FOG ADVISORY FURTHER WEST. LATEST HRRR GUIDANCE AND 11-3.9U SATELLITE IMAGERY SHOWING THIS AS WELL...SO CONFIDENCE IS HIGH ON EXPANDING THIS ADVISORY. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 806 PM MST FRI FEB 12 2016 LATEST IBM AND SNY OBSERVATIONS IN THE SOUTHERN PANHANDLE SHOWING VISIBILITIES DOWN NEAR 1/4 MILE. THESE VISIBILITY REPORTS HAVE NOT CHANGED MUCH OVER THE PAST HOUR. LATEST 11-3.9U SATELLITE IMAGERY SHOWING THE LOW CLOUDS/FOG SPREADING WEST TOWARDS LARAMIE COUNTY NEAR PINE BLUFFS. WILL CONTINUE TO MONITOR AND MAY NEED TO EXTEND THE ADVISORY FURTHER WEST. UPDATES HAVE BEEN SENT. UPDATE ISSUED AT 708 PM MST FRI FEB 12 2016 GETTINGS REPORTS FROM THE SIDNEY AND KIMBALL ASOS/AWOS OF REDUCED VISIBILITIES IN FOG ALREADY THIS EVENING. CERTAINLY NEED TO WATCH CONDITIONS TO SEE IF THIS FOG BECOMES MORE WIDESPREAD. WENT AHEAD AND EXPANDED FOG WEST UP THE PLATTE RIVER VALLEY INTO TORRINGTON AND ACROSS THE NORTHERN PANHANDLE AS WELL. WILL CONTINUE MONITORING. UPDATES HAVE BEEN SENT. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT) ISSUED AT 300 PM MST FRI FEB 12 2016 EARLY AFTERNOON WATER VAPOR IMAGERY SHOWED A UPPER RIDGE AXIS SITUATED OVER THE INTERMTN WEST WITH A DEEP UPPER TROUGH FROM HUDSON BAY CANADA TO FL. NORTHWEST FLOW ALOFT PREVAILED ACROSS THE FRONT RANGE AND HIGH PLAINS. THE LEADING EDGE OF A SHALLOW COLD AIR MASS HAD DRIFTED WEST INTO THE EASTERN 1/3 OF THE COWBOY STATE. EAST-NORTHEAST WINDS AND WESTERN EDGE OF STRATUS CLOUD DECK EXTENDED FROM NEAR LUSK WY TO JUST WEST OF SIDNEY NE. TEMPERATURES EAST OF THE FRONT WERE IN THE 20S AND 30S...WHILE WESTERLY WINDS AND 40S PREVAILED TO THE WEST. DURING THE NEXT 12-18 HOURS...PRIMARY CONCERNS WILL DEAL WITH POTENTIAL FOR PATCHY FREEZING DRIZZLE AND FOG OVER WESTERN NE PANHANDLE ASSOCIATED WITH THE SHALLOW COLD AIR MASS. THERE IS GOOD MODEL AGREEMENT PROGGING THE ARCTIC FRONT TO REMAIN NEARLY STATIONARY TONIGHT ACROSS THE EASTERN WY PLAINS THEN SLOWLY SHIFTING EAST INTO WESTERN NE SATURDAY MORNING. LATEST GFS/NAM BUFR SOUNDINGS INDICATE A NEARLY SATURATED LAYER FROM 700-950MB ALONG WITH A LIGHT LOW LEVEL SOUTHEASTERLY FLOW TONIGHT AND EARLY SATURDAY MORNING OVER WESTERN NE. PATCHY FREEZING DRIZZLE AND FOG DEVELOPING LATER THIS EVENING AND LINGERING THROUGH MID-LATE MORNING. THE FOG/DRIZZLE MAY EXTEND AS FAR WEST AS A LUSK WY-KIMBALL NE LINE...BUT CONFIDENCE NOT HIGH ATTM AND NEXT SHIFT CAN REEVALUATE WITH 00Z MODEL GUIDANCE. A SHORTWAVE TROUGH ENTERING THE PACIFIC NORTHWEST TONIGHT WILL QUICK MOVE ACROSS THE ID/MT SATURDAY MORNING...NORTHERN WY SATURDAY AFTERNOON...AND SD/NORTHERN NE SATURDAY NIGHT. THIS SHORTWAVE WILL INCREASE THE LEESIDE SURFACE PRESSURE GRADIENT WITH THE POTENTIAL FOR A GAP WIND EPISODE FOR ARLINGTON AND BORDEAUX SATURDAY AFTERNOON AND EVENING. THE CRAIG-CASPER HEIGHT 700-850MB GRADIENT EXCEEDS 60M BY 21Z SATURDAY...AND DECREASED BELOW 50M BY 06Z SUNDAY. WINDS AT 700MB PEAK NEAR 60 KT AT 00Z SUNDAY. ISSUED A HIGH WIND WATCH FOR WY ZONES 106 AND 110 FROM NOON TO 9 PM SATURDAY FOR THE POTENTIAL FOR WEST WIND GUSTS TO 60 MPH. SATURDAY WILL BE MILDER...ESPECIALLY EAST OF I-25 AS WESTERLY DOWNSLOPING WINDS SCOUR OUT THE SHALLOW COLD AIR MASS. AFTER A BRIEF LULL IN THE HIGH WINDS SATURDAY NIGHT...THEY PICK UP AGAIN SUNDAY MORNING WITH THE POTENTIAL FOR HIGH WINDS SPREADING EAST TO I-25 SUNDAY AFTERNOON. IF THE MODELS REMAIN CONSISTENT...HIGH WIND HEADLINES MAY BE ISSUED SATURDAY. SUNDAY WILL BE 5-10 DEGREES FOLLOWING THE PASSAGE OF A PACIFIC COLD FRONT. SOME LIGHT PRECIPITATION DEVELOPS INITIALLY ACROSS NORTHEAST WY/WESTERN SD SATURDAY EVENING AND SHIFTS EAST SATURDAY NIGHT. PACIFIC MOISTURE INCREASES WEST OF THE LARAMIE RANGE SUNDAY MORNING WITH LIGHT SNOW BECOMING MORE WIDESPREAD SUNDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF LIGHT SNOW SPREADING EAST ONTO THE SOUTHEAST WY PLAINS SUNDAY NIGHT. MOST OF THE ACCUMULATING SNOW WILL OCCUR OVER THE SNOWY/SIERRA MADRE RANGES WITH UP TO 3 INCHES POSSIBLE. .LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY) ISSUED AT 200 PM MST FRI FEB 12 2016 MONDAY...RELATIVELY MOIST NORTHWEST FLOW ALOFT WILL PRODUCE OROGRAPHIC SNOWFALL ACROSS THE SNOWY AND SIERRA MADRE RANGES WITH A SLIGHT CHANCE OF PRECIPITATION NORTH OF A DOUGLAS TO SCOTTSBLUFF LINE. TUESDAY...DRIER AND WARMER AS HEIGHTS AND THICKNESSES RISE AND THE ATMOSPHERE DRIES OUT SOMEWHAT. WEDNESDAY...PERHAPS THE WARMEST DAY NEXT WEEK AS THE RIDGE ALOFT MOVES OVERHEAD AND SURFACE LEE TROUGHING BECOMES WELL ESTABLISHED WITH VERY DRY ATMOSPHERE PROMOTING WARMING TEMPERATURES. THURSDAY...CONTINUED MILD IN THE WARM SECTOR AHEAD OF APPROACHING COLD FRONT. SOME OROGRAPHIC SNOW SHOWERS POSSIBLE NEAR THE SNOWY AND SIERRA MADRE RANGES LATE IN THE DAY WITH A SHORTWAVE TROUGH APPROACHING. FRIDAY...COOLER IN THE WAKE OF THE SHORTWAVE TROUGH ALOFT AND ITS ASSOCIATED COLD FRONT PASSAGE...THOUGH STILL RELATIVELY MILD FOR MID FEBRUARY BASED ON PROJECTED HEIGHTS AND THICKNESSES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT) ISSUED AT 1010 PM MST FRI FEB 12 2016 BACKDOOR FRONT TO REMAIN ALONG THE EAST SLOPES OF THE LARAMIE RANGE THROUGH THE OVERNIGHT HOURS. EASTERLY UPSLOPING WINDS OVER THE PANHANDLE WILL CONTINUE WIDESPREAD IFR/LIFR CONDITIONS FOR OUR NEBRASKA PANHANDLE AIRPORTS AT LEAST THROUGH 18Z. FOLLOWED LATEST HRRR GUIDANCE AND CONFIDENCE IS HIGH THAT LOW CONDITIONS WILL CONTINUE. WEST WINDS RETURN AFTER 18Z THAT WILL SCOUR OUT THE LOWER STRATUS. && .FIRE WEATHER... ISSUED AT 200 PM MST FRI FEB 12 2016 NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND WITH COOL TO MILD TEMPERATURES AND RESIDUAL SNOW COVER. A NORTH-SOUTH ORIENTED COLD FRONT OVER THE HIGH PLAINS WILL SHIFT EASTWARD SATURDAY AS A QUICK MOVING UPPER LEVEL DISTURBANCE MOVES INTO NORTHERN WYOMING. THIS DISTURBANCE WILL TIGHTEN THE LEESIDE SURFACE PRESSURE GRADIENT WITH WEST WINDS BECOMING STRONG AND GUSTY ACROSS MUCH OF SOUTHEAST WYOMING. THE WINDY CONDITIONS WILL CONTINUE SUNDAY AS WELL. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...HIGH WIND WATCH FROM SATURDAY AFTERNOON THROUGH SATURDAY EVENING FOR WYZ106-110. DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR WYZ119. NE...DENSE FOG ADVISORY UNTIL 5 AM MST SATURDAY FOR NEZ054-055. && $$ UPDATE...GCC SHORT TERM...MAJ LONG TERM...RUBIN AVIATION...GCC FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST SUN FEB 14 2016 .UPDATE... ISSUED AT 652 PM MST SUN FEB 14 2016 UPSTREAM IN SOUTHWESTERN WYOMING SNOWED HAS STOPPED FOR NOW AS THE BULK OF ENERGY HAS MOVED DOWNSTREAM ALONG THE CONTINENTAL DIVIDE AREAS OF CENTRAL COLORADO. ALLOWED WINTER WEATHER ADVISORIES TO CONTINUE THROUGH TOMORROW DESPITE THE OBVIOUS BREAK IN SNOWFALL...WHICH HAS ALREADY BEGUN AROUND THE STEAMBOAT SPRINGS AREA AND WILL SOON BEGIN IN THE FLATTOPS. THE SHORT TERM MODELS ARE INDICATING THE BREAK TO LAST THROUGHOUT THE NEXT 6 TO 12 HOURS...BUT SNOW PICKING UP TOWARD DAYBREAK FROM THE NORTHWEST AGAIN. TOMORROW/S SNOW IS STILL LOOKING MORE OROGRAPHICALLY DRIVEN AS OPPOSED TO TODAY/S DISTURBANCE WHICH ALLOWED SNOWFALL ALONG THE LOWER ELEVATIONS OF NORTHWEST COLORADO ALONG THE FOOTHILLS OF THE MOUNTAINS. && .SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT) ISSUED AT 306 PM MST SUN FEB 14 2016 A FAST MOVING SYSTEM WAS PRODUCING ITS GREATEST IMPACTS THIS AFTERNOON INTO EARLY EVENING. THE DYNAMICAL PORTION OF THE STORM IS DRIVEN BY A N-S ORIENTED 110KT JET STREAK. THIS JET SHIFTED INTO NW CO AROUND MIDDAY AND WILL BE EAST OF THE DIVIDE THIS EVENING. DENDRITIC CRYSTAL GROWTH REGION IS NEAR SATURATION THROUGH THIS PERIOD AT AROUND 600MB/14KFT. ON THE EAST SIDE OF THE JET NOSE...SNOW SPREAD INTO NW COLORADO JUST BEFORE NOON AND INTO THE ROARING FORK VALLEY AROUND 1PM. THE I-70 CORRIDOR FROM GLENWOOD EAST COULD GET SOME LIGHT ACCUMULATION THIS AFTERNOON. BEFORE MIDNIGHT THE DYNAMICAL PORTION OF THE STORM IS OVER AND IT BECOMES AN WNW OROGRAPHIC EVENT. THIS IS STILL OPTIMAL FOR THE PARK RANGE AND STEAMBOAT SPRINGS AREA. CURRENT HIGHLIGHTS EMPHASIZE THE BEST SNOW FROM STEAMBOAT NORTHWARD AND THIS STILL LOOKS CORRECT. THE PARK RANGE TO VAIL PASS AND THE FLAT TOPS AND ADJOINING VALLEYS WILL CONTINUE TO SEE SNOW ACCUMULATIONS THROUGH THE NIGHT. WIND GUSTS OF 30-40 MPH OVER THE HIGH TERRAIN WILL PRODUCE BLOWING AND DRIFTING SNOW. AREAS OF LATE NIGHT FOG WILL LIKELY FORM IN NW COLORADO...EASTERN PORTIONS OF THE I-70 CORRIDOR...AND ROARING FORK VALLEY. UPPER LEVEL SUPPORT BY WAY OF THE JET STREAM WILL HAVE SHIFTED WELL TO OUR EAST BY MONDAY MORNING WHICH SHOULD CAUSE SNOWFALL UP NORTH TO DECREASE IN INTENSITY. ACCORDING TO THE NAM AND GFS...SNOW IS NOT OVER THOUGH AS FAVORABLE OROGRAPHICS THEN KICK IN ALLOWING SNOW TO CONTINUE FOR MUCH OF MONDAY ESPECIALLY FOR THE MOUNTAINS AND FLAT TOPS. HOWEVER...THE VERY SHORT RANGE MODELS...TO INCLUDE THE HRRR AND RAP13...SHOW PRECIP DWINDLING THROUGH THE DAY WITH ONLY MINIMAL ACCUMULATION EXPECTED. WITH H7 WINDS COMING FROM THE NORTHWEST...OROGRAPHICS LOOK LIKE THEY WILL BE IN PLAY SO THE GOING ADVISORIES WILL REMAIN IN PLACE. LATER SHIFTS CAN REASSESS AND PULL DOWN EARLY IF NEEDED. THE REST OF THE CWA WILL SEE WARMING TEMPS MONDAY WITH MANY AREAS SEEING PARTLY CLOUDY SKIES. AREAS DOWN SOUTH WILL LIKELY SEE MORE SUN THAN CLOUDS WHILE MTNS WILL SEE VARIABLE CLOUDINESS. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 306 PM MST SUN FEB 14 2016 BY NOON TUESDAY...SNOWFALL WILL HAVE ENDED AS HEIGHT RISES INDICATE HIGH PRESSURE BUILDING IN. THE HIGH PRESSURE WILL BE IN CONTROL FROM TUESDAY THROUGH THURSDAY WITH ONLY SOME HIGH CLOUDS MOVING OVERHEAD FROM TIME TO TIME. TEMPERATURES WILL CONTINUE THEIR WARM TREND FOR A NICE START TO THE WORK WEEK. STARTING LATE WEDNESDAY...BOTH THE GFS AND EC HIGHLIGHT AN AREA OF LOW PRESSURE APPROACHING THE WEST COAST BRINGING PLENTY OF PRECIP TO NRN CALIF UP INTO BRITISH COLUMBIA. HOWEVER...THE CLOSED LOW FILLS IN AND MOVES NORTH WHILE THE ASSOD TROUGH CONTINUES TO MOVE EASTWARD. THERE IS SOME UPPER LEVEL SUPPORT WITH THIS FEATURE AS THE JET STREAM CARRIES THIS WAVE ACROSS THE INTERMOUNTAIN WEST. AS THE WAVE MOVES EAST...THE JET BECOMES MORE EAST TO WEST ORIENTED WHICH WILL CAUSE THE SYSTEM TO QUICKLY MOVE OVER THE AREA. MODELS SUGGEST INCREASED CLOUDS THURSDAY WITH SOME SHOWERS THROUGH THE DAY. THE HEAVIEST PRECIP LOOKS TO FALL LATE THURSDAY NIGHT INTO EARLY FRIDAY MORNING AGAIN FAVORING THE NRN AND CENTRAL MTNS...FLAT TOPS...AND POSSIBLY THE GRAND MESA. BECAUSE OF THE JET ORIENTATION THOUGH...IT LOOKS AS THOUGH A QUICK 6 HRS OF HEAVIER PRECIP BEFORE IT SHUTS OFF ABRUPTLY BY DAYBREAK FRIDAY. A FEW MORE MODEL RUNS WILL INCREASE CONFIDENCE WITH EVOLUTION OF SYSTEM. AFTER THAT...A WEAK WAVE LOOKS TO MOVE OVER THE CWA SATURDAY BRINGING VERY LIGHT PRECIP TO THE AREA BEFORE IT QUICKLY SHIFTS EASTWARD. EXPECT A NICE START TO THE WORK WEEK BEFORE MORE PRECIP ENTERS THE PICTURE THURSDAY NIGHT INTO FRIDAY. TEMPERATURES WILL ALSO REMAIN ON THE WARM SIDE WHICH WILL BE NICE FRO MID-FEBRUARY. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 958 PM MST SUN FEB 14 2016 A BREAK IN THE SNOW SHOWERS IS OCCURRING AND WILL CONTINUE TO DO SO THROUGH ABOUT 10 TO 12Z MONDAY MORNING. SNOW SHOWERS WILL IMPACT HIGH MOUNTAIN AREAS OF WESTERN COLORADO FROM RABBIT EARS PASS SOUTH TO VAIL PASS BEGINNING AROUND 12Z...BUT WILL BE MAINLY CENTERED TO THE PARK/GORE/ELKHEAD RANGES. BREEZY CONDITIONS WITH GUSTS TO 25KTS ARE POSSIBLE THROUGHOUT THE DAY MONDAY. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST MONDAY NIGHT FOR COZ004-005-013. WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ010. UT...NONE. && $$ UPDATE...JAM SHORT TERM...JOE/TGR LONG TERM...TGR AVIATION...JAM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
340 AM EST MON FEB 15 2016 .DISCUSSION... ...SLIGHT CHANCE FOR STRONG STORMS THIS EVENING/OVERNIGHT... TODAY-TONIGHT...SHORTWAVE TROUGH DIGGING ACROSS THE SOUTHERN STATES WILL GENERATE A SURFACE LOW VICINITY OF THE LOWER MISSISSIPPI VALLEY EARLY TODAY...WHICH WILL GRADUALLY DEEPEN WHILE LIFTING INTO THE SOUTHERN APPALACHIANS TONIGHT. THIS SYSTEM WILL BE MOVING RATHER QUICKLY SO MOISTURE RETURN AND INSTABILITY WILL BE LIMITED. STILL...WITH GOOD LARGE SCALE ASCENT...EXPECT HIGH RAIN CHANCES PRIMARILY DURING THE OVERNIGHT PERIOD. THE GFS AND HRRR HAVE BEEN SHOWING SOME CONVECTION DEVELOPING LATE AFTERNOON/EARLY EVENING FROM BOUNDARY INTERACTIONS. HAVE GONE WITH 30 PERCENT POPS DURING THE TODAY PERIOD FOR THIS POSSIBILITY... THEN INCLUDED A SLIGHT CHANCE FOR THUNDERSTORMS THROUGH LATE EVENING AS DEEPENING TROUGH GETS NEARER. DURING THE OVERNIGHT PERIOD...MOS POPS INCREASE TO 60-90 PERCENT. DID NOT GO QUITE THAT HIGH AND HAVE SETTLED ON LIKELY POPS (60-70 PERCENT) WITH A CONTINUED SLIGHT CHANCE FOR STORMS...EXCEPT 50 PERCENT POPS IN THE SOUTH. THE MAIN CONCERN WHEN THUNDER IS IN THE FORECAST THIS TIME OF THE YEAR WILL BE THE THREAT FOR STRONG OR SEVERE STORMS. WITH SURFACE DEW POINTS RECOVERING ONLY INTO THE LOWER 60S AND THE PRIMARY SUPPORT FOR DEEP CONVECTION OCCURRING OVERNIGHT...INSTABILITY WILL BE LIMITED. ADDITIONALLY...LOW LEVEL WIND FIELDS ONLY INCREASE TO ABOUT 30-35 KNOTS. BUT IT WILL BE QUITE COLD ALOFT WITH 500 MB TEMPS AROUND MINUS 15 CELSIUS. WILL HAVE TO WATCH FOR PRE FRONTAL CONVECTION OVER THE GULF SPREADING INLAND AND HOLDING TOGETHER SOMEWHAT AS SURFACE WINDS STAY BACKED ENOUGH TO SUSTAIN LOW LEVEL CONVERGENCE. THE GFS SHOWS 0-1KM HELICITY VALUES 100-200 M2S2 OVERNIGHT SO DO NOT WANT TO RULE OUT A SMALL RISK FOR STORM ORGANIZATION AND SEVERE WEATHER. THE STORM PREDICTION CENTER DOES HAVE A MARGINAL RISK FOR ALL OF EAST CENTRAL FLORIDA EXCEPT THE TREASURE COAST. TUE...BOTH THE ECMWF AND GFS SHOW THE SURFACE FRONT EXITING CENTRAL FLORIDA LATE AFTERNOON AND OVER SOUTH FLORIDA BY MID EVENING AS THE PARENT LOW OVER SW PA AND WA LIFTS NORTHEAST TO THE LOWER SAINT LAWRENCE RIVER VALLEY IN CANADA. PERCEPTIBLE WATER VALUES DROP OFF FROM AROUND 1 INCH AT 7AM/12Z TUE MORNING TO 0.75 INCHES SOUTHERN AREAS AND 0.25 INCHES NORTH LAKE COUNTY EARLY AFTERNOON. ANY RAIN CHANCES LOOK TO BE OVER AND EAST OF THE GULF STREAM. HIGHS MID 70S ORLANDO TO CAPE CANAVERAL AND NORTH AND THE UPPER 70S SOUTH OF THE ABOVE MENTIONED LINE. WED-SUN...THE 500MB TROUGH CLEARS CENTRAL FLORIDA OVERNIGHT WED AND IS REPLACED BY AN UPPER LEVEL HIGH PRESSURE CENTER THAT WORKS ITS WAY FROM THE SOUTHWEST U.S. COAST TO EASTERN GULF OF MEXICO SAT. TIME HEIGHT CROSS SECTIONS SHOW DRY SUBSIDENT AIR MASS FROM TUE NIGHT TO OVERNIGHT THU/FRI MORNING BEFORE ANY APPRECIABLE MOISTURE STARTS TO OCCUR. LITTLE OR NO MID AND UPPER LEVEL DYNAMIC SUPPORT AND THE A DRY ATMOSPHERE LIMITS RAIN POTENTIAL FOR RAIN. WEAK SURFACE HIGH PRESSURE OVER TEXAS BUILDS EAST ACROSS THE GULF OF MEXICO WED IS RE ENFORCED BY HIGH PRESSURE BUILDING FROM THE UPPER MID WEST ACROSS THE SOUTHEAST AND INTO THE ATLANTIC. WEST TO NORTHWEST WINDS WED BECOME NORTH THU AND EAST FRI AFTERNOON. HIGHS CLIMO LOW 70S AND LOWS MID UPPER 40S NORTH AND AROUND 50 SOUTHERN COUNTIES FORT PIERCE SOUTH. && .AVIATION...A MOISTENING SOUTHEAST WIND FLOW WILL PRODUCE CONSIDERABLE STRATOCUMULUS TODAY WITH CEILINGS MAINLY ABOVE 3500 FEET. THERE WILL BE A CHANCE FOR SHOWERS ESPECIALLY LATE IN THE DAY WITH LOCAL MVFR. AS A STRONG TROUGH ALOFT APPROACHES TONIGHT...SHOWERS WILL INCREASE IN COVERAGE AND EXPECT A SLIGHT CHANCE FOR STORMS SO MVFR CONDITIONS WILL BECOME MORE LIKELY AND LOCAL IFR WILL BE POSSIBLE. && .MARINE... TODAY-TONIGHT...POOR TO HAZARDOUS CONDITIONS FOR SMALL CRAFT OPERATION INDICATED. SOUTHEAST WINDS EARLY THIS MORNING HAVE BEEN 20 KNOTS AND GUSTY OFFSHORE WHILE A WEAK COASTAL TROUGH WAS KEEPING THE PRESSURE GRADIENT WEAKER NEAR SHORE. THIS TROUGH WILL BREAK DOWN DURING DAYTIME HEATING AND EXPECT WINDS NEAR 20 KNOTS...AND GUSTY TO 25 KNOTS OVER MOST OF THE WATERS BY LATE MORNING/EARLY AFTERNOON. WINDS WILL VEER MORE TO THE SOUTH TONIGHT WHILE STAYING AROUND 20 KNOTS. NO CHANGE TO THE PREVIOUS HEADLINES. TUE...SOUTHWEST WINDS TO 20 KNOTS AHEAD AND JUST AFTER FRONTAL PASSAGE. WINDS SHIFT TO THE WEST IN THE AFTERNOON THEN NORTHWEST TUE NIGHT. SEAS 6 TO 8 FEET WELL OFFSHORE EARLY TUE MORNING SUBSIDE TO 4 TO 6 FEET LATE TUE AFTERNOON. WED-FRI...10 TO 20 KNOT WINDS FIRST SHIFT TO THE NORTH WED THEN NORTHEAST AND EAST THU AND FRI AS THE HIGH PRESSURE MOVES EAST INTO NEW ENGLAND. MAY NEED SMALL CRAFT ADVISORY FOR SEAS IN THE GULF STREAM OVERNIGHT WED AS SEAS MAY REACH 7 FEET OR MORE DUE TO THE NORTH WIND. SEAS DROP OFF TO 6 FEET OR LESS THU AND FRI. && .PRELIMINARY POINT TEMPS/POPS... DAB 76 61 76 50 / 30 70 30 10 MCO 78 62 77 51 / 30 70 20 10 MLB 75 64 78 53 / 30 60 30 10 VRB 77 64 79 53 / 30 60 30 10 LEE 77 61 75 49 / 30 70 20 10 SFB 77 62 77 49 / 30 70 20 10 ORL 77 62 76 52 / 30 70 20 10 FPR 77 64 79 51 / 30 50 30 10 && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR SEBASTIAN INLET TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM. SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ SHORT TERM...LASCODY LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
338 AM EST MON FEB 15 2016 .SYNOPSIS... 09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFYING UPPER LEVEL PATTERN OVER THE CONUS EARLY THIS MORNING. TROUGHING THAT BROUGHT THE EXTREME COLD TO THE NORTHEASTERN STATES OVER THE PAST WEEKEND IS NOW LIFTING OUT OVER FAR EASTERN CANADA WITH HEIGHT RISING IN ITS WAKE OVER THESE FROZEN STATES. ELSEWHERE THE NORTHERN STREAM FLOW IS DOMINATING THE WEATHER ACROSS THE NATION. THIS FLOW ARRIVES OVER NORTH AMERICA WITHIN A STRONG JET CORE MOVING ASHORE OVER THE PACIFIC NORTHWEST/BRITISH COLUMBIA COASTS BEFORE DIVING SOUTHEAST THROUGH THE CONTINENTAL DIVIDE INTO AN AMPLIFYING CENTRAL CONUS TROUGH. THIS TROUGH WILL CONTINUE TO DIG SOUTH AND EASTWARD THROUGH TODAY AND BRING SHOWERS CHANCES BACK TO OUR FORECAST BY LATER TODAY INTO TONIGHT. WHILE THE MAIN SYSTEM AND COLD FRONT DUE TO ARRIVE TONIGHT/TUESDAY MORNING WILL BE MORE ASSOCIATED WITH THE ENERGY CURRENTLY DIVING SOUTH THROUGH THE CENTRAL/SOUTHERN PLAINS...A SEPARATE FRONT-RUNNING PIECE OF SHORTWAVE ENERGY IS CURRENTLY EJECTING OFF THE TEXAS/NORTHERN MEXICO COAST OVER THE WESTERN GULF OF MEXICO. THIS ENERGY WILL BE FIRST TO APPROACH THE FLORIDA PENINSULA LATER TODAY...BRINING AN INITIAL REGION OF UPLIFT AND SHOWER POTENTIAL BY LATER AFTERNOON...AND ESPECIALLY BY THE EARLY EVENING HOURS. MORE DETAILS ON THIS WHOLE PROCESS IN THE SHORT TERM DISCUSSION BELOW. WV IMAGERY SHOWS INITIAL UPPER LEVEL MOISTURE OVERSPREADING OUR SKIES...ESPECIALLY ACROSS CENTRAL AND NORTHERN PORTIONS OF THE FLORIDA PENINSULA. BELOW THIS LEVEL...THE MID PORTIONS OF THE TROP ARE STILL RATHER DRY...AS SEEN ON THE 15/00Z KTBW SOUNDING PROFILE. CROSS SECTIONAL ANALYSIS FROM BOTH THE GFS/ECMWF SUGGEST WHILE MODEST MOISTENING WILL BEGIN DURING THE NEXT 6-10 HOURS...OVERALL THESE MID-LEVELS WILL REMAIN FAIRLY DRY THROUGH MUCH OF THE MORNING...BUT THEN RAPIDLY BEGIN TO MOISTEN FROM THE TOP DOWN AS WE REACH THE MIDDAY HOURS AND INTO THE AFTERNOON. AT THE SURFACE...LARGE SCALE HIGH PRESSURE IS MIGRATING OFF THE EASTERN SEABOARD TO OUR NORTH THIS MORNING. THE SYNOPTIC GRADIENT FLOW AROUND THIS RIDGE IS PROVIDING A GENERAL EASTERLY FLOW TO OUR REGION. JUST NOW BEGINNING TO SEE THE FIRST SIGNS OF A SURFACE REFLECTION LOW NEAR THE ARKLATEX REGION UNDERNEATH THE AMPLIFYING UPPER TROUGH. THIS LOW WILL ORGANIZE THROUGH THE DAY AS IT MIGRATES EASTWARD THROUGH NORTHERN LA/AL/AL. AS THE LOW DEEPENS...WE SHOULD SEE OUR GRADIENT FLOW VEER MORE TO THE SOUTHEAST AND EVENTUALLY MORE SOUTHERLY. TEMPERATURES ARE CERTAINLY WARMER THIS MORNING THAN THEY WERE EARLY SUNDAY...DUE MAINLY TO AN IMPRESSIVE DEWPOINT RECOVERY WITHIN THE PAST 24 HOURS. CERTAINLY NO THREAT OF FROST OR FREEZING TEMPERATURES WITHIN OUR FORECAST AREA THIS MORNING. TO BE HONEST...DO NOT SEE A PATTERN THAT WOULD SUGGEST A THREAT FOR EITHER THROUGH THE DURATION OF THE FORECAST PERIOD. && .SHORT TERM (TODAY THROUGH TUESDAY)... KIND OF A COMPLEX/MESSY FORECAST FOR THE FIRST 24 HOURS OF THE SHORT TERM...AS AN ILL- DEFINED AND MUTLI-STAGE SYSTEM PASSES OVER THE REGION. THE TOUGHEST CALL WILL BE THE POTENTIAL FOR BREAKS TO EXIST IN THE BANDS OF SHOWERS THAT ARE FORECAST TO CROSS LATER TODAY AND TONIGHT. FAIRLY CONFIDENT THAT THESE BANDS WILL CROSS THE FORECAST AREA...BUT SOME SPOTS MAY JUST END UP BEING IN SOMEWHAT DRIER SWATHS (COMPARED TO OTHERS) DUE MAINLY TO THE DECREASING OVERALL STRUCTURE OF THE OMEGA FIELDS...AND WEAKENING LOW LEVEL FOCUS ALONG THE FRONT AS WE HEAD INTO THE OVERNIGHT. WILL TRY TO PUT IT ALL TOGETHER INTO A COHESIVE FORECAST. FOR THE FIRST HALF OF TODAY...THE FORECAST WILL BE DRY WITH A GENERAL INCREASE IN CLOUDS. THEREAFTER...AS MENTIONED ABOVE...WILL SEE AN INCREASE IN LARGE SCALE LIFT OVER THE REGION...AND A SLOW TOP DOWN MOISTENING OF THE TROP COLUMN. INITIAL SHORTWAVE ENERGY EJECTS THROUGH THE MIDDLE GULF LATER THIS MORNING AND INTO THE EASTERN GULF BY LATE THIS AFTERNOON. DEEP LAYER MODEST ISENTROPIC UPGLIDE/WAA REGIME WILL BE UNDERWAY MOST OF THE DAY OVER THE EASTERN GULF AHEAD OF THE SHORTWAVE ALONG THE 295-315K SURFACES. WITHIN THE LAYER FIELDS WE SEE INITIAL SATURATION DUE TO THIS UPGLIDE OCCUR WITHIN THE MID/UPPER LEVELS AND THEN WORK DOWN AS THE FIELDS EXPAND OVER THE FL PENINSULA. IT WILL BE RACE TO SEE IF THE COLUMN MOISTURE BECOMES SUFFICIENT BEFORE...THE SYNOPTIC QVECTOR CONVERGENCE AHEAD OF THE SHORTWAVE ARRIVES TO FURTHER ENHANCE THE OVERALL LIFT. THE PHASING OF THESE FACTORS WILL DETERMINE THE EXTENT OF THE SHOWER ACTIVITY DURING THE LATE AFTERNOON/EVENING HOURS. WILL HIGHLIGHT CHANCE POPS ESSENTIALLY REGION-WIDE AFTER 21Z...BUT IT IS VERY DIFFICULT TO SAY IF THE COVERAGE WILL BE ENOUGH TO CAUSE SIGNIFICANT IMPACTS FOR OUTDOOR ACTIVITIES. THE SECOND AND MAIN SHORTWAVE ENERGY DRIVING THE SURFACE LOW AND TRAILING COLD FRONT WILL THEN APPROACH AND PASS OVER THE REGION DURING THE OVERNIGHT HOURS. THIS IS WHERE THINGS BECOME COMPLEX FOR DIFFERENT REASONS. DURING THE EVENING HOURS WE ARE LIKELY TO SEE A RATHER SOLID AND HEALTHY BAND OF CONVECTION OFF TO OUR WEST AND NORTHWEST AHEAD OF THE COLD FRONT AS THE SYNOPTIC FORCING...DEEP LAYER SHEAR...AND SURFACE CONVERGENCE ARE ALL STRONG. HOWEVER...AS THE SHORTWAVE GETS CLOSER...GUIDANCE IS IN GOOD AGREEMENT THAT IT WILL TAKE ON AN INCREASINGLY NEGATIVE TILT. THE NEGATIVE TILT WILL GUIDE THE SURFACE LOW TO INCREASE LATITUDE WITH TIME. SO...AS THE FRONT APPROACHES...THE LOW WILL BE LIFTING FURTHER NORTHWARD...WITH LOW LEVEL WIND FIELDS CONTINUING TO VEER. THIS VEERING WILL ACT TO DECREASE THE FOCUS ALONG THE FRONT. THIS FACTOR ALONG WITH BEST SYNOPTIC FORCING STAYING JUST NORTH MAY BEGIN A DECREASING TREND IN CONVECTIVE STRUCTURE ALONG THE SOUTHERN END OF THE FRONT MOVING INTO OUR AREA. FOR STORMS THAT DO ARRIVE ALONG OUR COASTS...THERE ARE SOME FACTORS IN PLACE TO SUGGEST A FEW MIGHT BE STRONG. SPC HAS OUTLOOKED OUR CENTRAL/NORTHERN ZONES IN A MARGINAL RISK FOR STRONG STORMS. CERTAINLY LOOKING AT THE GUIDANCE...IT WOULD SUGGEST BEST CHANCES FOR STRONG UPDRAFTS STAY JUST NORTH...BUT ITS A CLOSE CALL. DECENT MID-LEVEL LAPSE RATES AROUND 7C/KM REACH PARTS OF THE NATURE COAST...ALONG WITH THE VERY SOUTHERN END OF THE 40+ KNOT LOW LEVEL JET. THE WIND FIELDS AND DEEP LAYER SHEAR WOULD NOT BE CONSIDERED IMPRESSIVE...BUT THEY ARE SUFFICIENT TO SUSTAIN ORGANIZED UPDRAFTS...AND RADAR TRENDS OF INDIVIDUAL STORMS WILL NEED TO BE MONITORED OVERNIGHT REGARDLESS OF OVERALL CONVECTIVE LINE ORGANIZATION. SECOND COMPLICATING FACTOR: DO WE SEE A CONVECTIVE BLOWUP OVER THE BAROCLINIC WARMER WATERS OF THE SOUTHERN LOOP CURRENT TO OUR SOUTHWEST BEFORE THE FRONT GETS TO OUR REGION? THIS SOMETIMES OCCURS WITH SHORTWAVES SIMILAR TO THIS ONE. WHEN THIS OCCURS...TWO THINGS HAPPEN. THIS CONVECTION GENERALLY HEADS EAST QUICKLY TOWARD SOUTHERN FLORIDA/THE KEYS...WHILE CUTTING OFF INFLOW TO CONVECTION FURTHER NORTH...AND ALSO SENDING CONSIDERABLE LATENT HEATING INTO THE MID-LEVELS STREAMING OVER OUR REGION. BOTH OF THESE IMPACTS ARE NEGATIVES TO HEALTHY CONVECTION. IN THIS CASE...WE COULD SEE A SPLIT WHERE BETTER CONVECTION PASSES TO OUR SOUTH...AND PASSES TO OUR NORTH. SEVERAL OF THE HIRES CONVECTION ALLOWING GUIDANCE MEMBERS ARE SHOWING THIS SCENARIO...SO IT CAN NOT BE IGNORED. OK...YOU GET THE POINT. NOT AN EASY FORECAST. NO FORECAST IS EVER PERFECT...AND THIS IS SIMPLY A SITUATION THAT WILL NEED TO BE MONITORED CLOSELY THROUGH THE DAY AND ADJUSTED AS NECESSARY. LUCKILY AFTER TUESDAY MORNING...THE PATTERN QUIETS DOWN AND BECOMES MUCH MORE STRAIGHT FORWARD FOR A FEW DAYS. SPEAKING OF TUESDAY...SHOWERS END DURING THE MORNING AS THE COLD FRONT AND SUPPORTING SHORTWAVE ENERGY EXIT THE REGION. SURFACE RIDGING QUICKLY BUILDS IN FROM THE WEST AND NORTHWEST FOR THE SECOND HALF OF THE DAY. THE AIRMASS BEHIND THIS FRONT IS ONLY SLIGHTLY COOLER AND DRIER...AND ITS PASSAGE WILL NOT HAVE THE POST-IMPACT THAT HAS BEEN SEEN RECENTLY WITH PREVIOUS FRONTS. IN FACT...TEMPERATURES TUESDAY AFTERNOON ARE LIKELY TO STILL REACH THE 70S OVER THE INLAND ZONES. TEMPS WILL BE AT LEAST SEVERAL DEGREES COOLER NEAR THE COAST WITH A MODERATE WESTERLY ONSHORE FLOW OFF THE SHELF WATERS. && .LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)... AN UPPER LEVEL TROUGH OVER AND ALONG THE EASTERN SEABOARD ROTATES OUT OVER THE ATLANTIC AS A BUILDING RIDGE ALOFT THE WESTERN STATES SLIDES EAST ACROSS THE CONUS THROUGH THE REST OF THE WEEK THEN FLATTENS ACROSS THE SOUTHEAST QUARTER OF THE NATION FOR THE WEEKEND. SURFACE LOW PRESSURE IN THE MID-ATLANTIC STATES EXITS UP INTO THE SAINT LAWRENCE VALLEY BY THE END OF WED...WITH A WEAK TROUGH SWEEPING ACROSS THE SOUTHEASTERN STATES. A SPRAWLING SURFACE RIDGE FROM MANITOBA TO TX STRENGTHENS AS IT TRACKS EASTWARD...STRETCHING FROM THE CANADIAN MARITIMES TO THE GULF OF MEXICO BY FRI. DURING THE WEEKEND THIS RIDGE PIVOTS OVER THE ATLANTIC WHILE RIDGING BACK ACROSS THE SOUTHEAST U.S. AND MUCH OF THE GULF. THE WEAK TROUGH MOVES BY TO THE NORTH ON WED WITH LITTLE IMPACT TO THE AREA. THEN THE HIGH PRESSURE IN THE WEST TAKES CONTROL AS IT MOVES EAST THEN SOUTHEAST...WITH CLEAR/MOSTLY CLEAR SKIES AND A DRY STABLE AIR MASS. TEMPERATURES ON THE COOL SIDE...INITIALLY...BUT CLOSE TO SEASONAL. THEN AS THE SURFACE HIGH CENTER MOVES OUT OVER THE ATLANTIC SAT AND SUN THE LOW LEVEL FLOW BECOMES MORE EASTERLY AND WARMER WITH TEMPERATURES RISING TO NEAR OR JUST ABOVE SEASONAL. THIS FLOW WILL ALSO PROVIDE AN INCREASE IN MOISTURE WITH A FEW MORE CLOUDS. && .AVIATION... NO SIGNIFICANT RESTRICTIONS ARE ANTICIPATED THROUGH THE DAYLIGHT HOURS...ALTHOUGH A FEW SHOWERS ARE EXPECTED TO BEGIN OVERSPREADING THE TERMINALS AFTER MID-AFTERNOON. HIGHER POTENTIAL FOR SHOWERS AND A FEW STORMS ARE IN THE FORECAST TONIGHT...WITH GUIDANCE SUGGESTING WIDESPREAD IFR/MVFR CIGS DEVELOPING AFTER 03Z. SOME POTENTIAL FOR SEA FOG DEVELOPMENT AS WELL LATE AT NIGHT THAT MAY IMPACT KTPA/KPIE/KSRQ. CONFIDENCE IN SEA FOG IS NOT HIGH ENOUGH TO INCLUDE IN CURRENT TAFS...BUT WILL NEED TO BE MONITORED CLOSELY WITH FUTURE FORECASTS. && .MARINE... HIGH PRESSURE TO OUR NORTH MIGRATES OFF THE EASTERN SEABOARD TODAY AS A COLD FRONT ORGANIZES ACROSS THE CENTRAL GULF OF MEXICO AND APPROACHES THE FORECAST WATERS. SOUTHEASTERLY WINDS EXPECTED FOR TODAY WITH A TURN TO THE SOUTH OVERNIGHT AHEAD OF THE FRONT. SHOWERS AND STORMS ARE EXPECTED TO INCREASE IN COVERAGE LATER THIS AFTERNOON INTO THE OVERNIGHT HOURS. THE COLD FRONT CROSSES THE REGION LATE TONIGHT INTO TUESDAY MORNING WITH A WIND SHIFT TO THE WEST AND NORTHWEST IN ITS WAKE. HIGH PRESSURE THEN RIDGES DOWN FROM THE NORTH INTO THE EASTERN GULF FOR THE DURATION OF THE FORECAST PERIOD. WATCHING THE POTENTIAL FOR PATCHY SEA FOG DEVELOPMENT TONIGHT INTO TUESDAY MORNING...MAINLY TO THE NORTH OF ENGLEWOOD. CONDITIONS ARE MARGINAL FOR FOG DEVELOPMENT...AND WILL NEED TO BE MONITORED CLOSELY WITH FUTURE FORECASTS. && .FIRE WEATHER... HIGH PRESSURE WELL TO OUR NORTH MOVES OFF THE EASTERN SEABOARD TODAY...WITH WINDS COMING AROUND FROM EASTERLY TO SOUTHEASTERLY. LOW LEVEL MOISTURE CONTINUES TO INCREASE KEEPING RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS. CONDITIONS WILL HOWEVER CREATE HIGH DISPERSION INDICES OVER PORTIONS OF THE REGION THIS AFTERNOON. A COLD FRONT WILL CROSS THE AREA LATER TONIGHT INTO TUESDAY MORNING WITH A ROUND OR TWO OF SHOWERS AND THUNDERSTORMS. THESE SHOWERS WILL END BY TUESDAY AFTERNOON...AND BE FOLLOWED BY A PROLONGED PERIOD OF DRY WEATHER THROUGH THE REMAINDER OF THE WEEK. THE AIRMASS BEHIND THIS FRONT IS ONLY SLIGHTLY COOLER AND DRIER...AND THEREFORE...NO CRITICAL LEVELS OF RELATIVE HUMIDITY OR RED FLAG CONDITIONS ARE ANTICIPATED THROUGH THE NEXT SEVERAL DAYS. FOG POTENTIAL... NO FOG IS EXPECTED THIS MORNING. THERE IS SOME POTENTIAL FOR PATCHY SEA FOG DEVELOPMENT LATE TONIGHT INTO TUESDAY MORNING. IF SEA FOG DEVELOPS...THEN FORECAST SOUTHWEST TO WEST FLOW COULD PUSH THE REDUCED VISIBILITY ONSHORE AT THE IMMEDIATE COAST. && .PRELIMINARY POINT TEMPS/POPS... TPA 74 63 71 54 / 30 60 20 10 FMY 77 64 77 57 / 30 50 30 10 GIF 77 62 76 52 / 30 60 30 0 SRQ 72 61 69 54 / 30 60 20 10 BKV 77 61 73 45 / 30 60 20 10 SPG 73 62 70 56 / 30 60 20 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...BEACH HAZARDS STATEMENT THROUGH TUESDAY EVENING FOR COASTAL CHARLOTTE-COASTAL LEE-COASTAL MANATEE-COASTAL SARASOTA. GULF WATERS...NONE. && $$ SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
311 AM EST MON FEB 15 2016 .SYNOPSIS... A WARM FRONT WILL EXTEND THROUGH SOUTHERN GEORGIA AND ALONG THE SOUTH CAROLINA COAST TODAY. ASSOCIATED LOW PRESSURE MOVING INTO THE LOWER MISSISSIPPI RIVER VALLEY TODAY WILL BE NEAR THE FORECAST AREA TONIGHT. DRYING WILL OCCUR TUESDAY AS THE LOW LIFTS NORTHWARD AND FARTHER AWAY FROM THE AREA. && .NEAR TERM /THROUGH TONIGHT/... TODAY...COLD HIGH PRESSURE WILL BE WEDGED INTO THE FORECAST AREA WITH A WARM FRONT NEAR THE COAST AND IN SOUTHERN GEORGIA. THE FRONT WILL LIFT NORTHWARD SLOWLY. THE NAM SURFACE-BASED LI PATTERN MAINTAINS THE WEDGE PATTERN HERE THROUGH TODAY. STRONG ISENTROPIC LIFT SUPPORTS PRECIPITATION BUT IT SHOULD REMAIN LIMITED BECAUSE OF SHALLOW MOISTURE AND LITTLE UPPER-LEVEL LIFT. THE NAM...GFS...ECMWF...AND ALL SREF MEMBERS INDICATE LITTLE PRECIPITATION...0.01 OF AN INCH THIS MORNING...AND 0.01 TO 0.1 OF AN INCH THIS AFTERNOON. THE HRRR HAS A FEW PATCHES OF LIGHT PRECIPITATIONS THIS MORNING WITH A LITTLE MORE COVERAGE THIS AFTERNOON. SURFACE WET BULB TEMPERATURES AND MODEL FORECAST SOUNDINGS SUPPORT A PREDOMINATE PRECIPITATION TYPE OF FREEZING RAIN OR FREEZING DRIZZLE BECOMING ALL LIQUID FROM SOUTH TO NORTH. THE TIMING SUPPORTS MORE OF A THREAT IN THE NORTH AND WE HAVE POSTED A FREEZING RAIN ADVISORY IN THE NORTH SECTION. THE THREAT OF FREEZING RAIN WILL LIKELY CONTINUE IN THE EXTREME NORTH PART UNTIL ABOUT 100 PM BASED ON THE SREF MEAN TEMPERATURE. IT IS POSSIBLE THE COLDER AIR WILL REMAIN IN PLACE LONGER AS INDICATED BY THE IN-HOUSE WEDGE SCHEME. HOWEVER...IT IS BASED ON THE NAM WHICH AS HAD A COLD BIAS LATELY. GIVEN THE VERY LOW QPF WE EXPECT JUST TRACE ICE ACCUMULATIONS BUT IT TAKES LITTLE ICE TO CAUSE ISSUES. THE THREAT SHOULD BE MAINLY ON ELEVATED SURFACES SUCH AS BRIDGES AND OVERPASSES. TONIGHT...TEMPERATURES SHOULD BE ABOVE FREEZING THROUGHOUT THE AREA AS WARMING OCCURS AHEAD OF APPROACHING LOW PRESSURE. THE NOCTURNAL LOW WILL OCCUR AT SUNSET. CONVERGENCE ASSOCIATED WITH THE LOW...A STRONG H85 JET AND H5 SHORTWAVE TROUGH WILL RESULT IN SHOWERS TONIGHT. THE GUIDANCE WAS CONSISTENT WITH CATEGORICAL POPS. THE NAM...GFS...ECMWF...AND SREF MEAN SUPPORT RAINFALL OF 0.5 TO 1 INCH. THE MODELS DEPICT A NEGATIVE TILT UPPER TROUGH. STRONG UPPER DIVERGENCE AND THE LOW-LEVEL JET MAY RESULT IN ENOUGH INSTABILITY FOR A FEW ELEVATED THUNDERSTORMS. THE NAM INDICATES CROSS TOTALS IN THE MID 20S. DESPITE THE STRONG SHEAR THE THREAT OF SEVERE THUNDERSTORMS SHOULD REMAIN LOW BECAUSE OF A LACK OF SURFACE-BASED INSTABILITY AS INDICATED BY THE NAM LI FORECAST. IT WILL LIKELY BECOME BREEZY TONIGHT WITH INCREASED MIXING NEAR THE COLD FRONT. WE WILL LIKELY NEED A LAKE WIND ADVISORY. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... DRYING SHOULD OCCUR TUESDAY BEHIND THE COLD FRONT AND MAIN MID- LEVEL SHORTWAVE TROUGH. MIXING AND THE PRESSURE GRADIENT ASSOCIATED WITH LOW PRESSURE LIFTING NORTH OF THE AREA SHOULD RESULT IN BREEZY CONDITIONS. A LAKE WIND ADVISORY WILL LIKELY BE NEEDED. THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY NIGHT. A PRESSURE RIDGE WEST OF THE AREA SHOULD MAINTAIN DRY CONDITIONS WEDNESDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST TUESDAY THROUGH WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GFS AND ECMWF DISPLAY DRY RIDGING DOMINATING THROUGH THE MEDIUM-RANGE PERIOD EXCEPT MOISTURE DOES APPEAR TO INCREASE SATURDAY OR SUNDAY ASSOCIATED A DEVELOPING WARM FRONT. THE GFS...ECMWF... AND EKD MOS HAVE POPS LESS THAN 10 PERCENT THROUGH FRIDAY...AND 5 TO 20 PERCENT SATURDAY AND SUNDAY. THE MOS HAS NEAR OR ABOVE NORMAL TEMPERATURES DURING THE PERIOD. && .AVIATION /08Z MONDAY THROUGH FRIDAY/... HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF THE TAF PERIOD. MVFR CIGS ACROSS THE TAF SITES EARLY THIS MORNING WITH EASTERLY WINDS 4 TO 8 KNOTS. THE HRRR AND GFS MODELS MORE PESSIMISTIC WITH CIGS LOWERING TO IFR 12Z-14Z. GIVEN LOW CONFIDENCE WILL KEEP CIGS AT OR ABOVE 1000 FEET. HOWEVER...ALL MODELS INDICATE IFR/LIFR CONDITIONS DEVELOPING BY 16/00Z. GIVEN LATEST NAM MODEL GUIDANCE AND CAE VWP...WILL MENTION LLWS AT ALL TAF SITES UNTIL AROUND 15Z WITH 30 KTS AOB 2000 FT POSSIBLE. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS. MOISTURE AND ISENTROPIC LIFT WILL INCREASE ACROSS THE AREA EARLY THIS MORNING AS WEDGE CONDITIONS DEVELOP. THERE IS A SLIGHT CHANCE OF RAIN AT AGS/DNL/OGB AND FREEZING RAIN AT CAE/CUB BEGINNING JUST BEFORE DAYBREAK MONDAY. THE CHANCE OF RAIN WILL INCREASE THROUGH THE MORNING HOURS BUT AS TEMPERATURES RISE AT CAE/CUB...THE THREAT OF ANY FROZEN PRECIP WILL DIMINISH. HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING AND MINIMAL IF ANY VISIBILITY IMPACTS. EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ015-016. && $$ SYNOPSIS...99 NEAR TERM...99 SHORT TERM...99 LONG TERM...99 AVIATION...99
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
314 AM CST MON FEB 15 2016 .SHORT TERM...(Today) ISSUED AT 314 AM CST MON FEB 15 2016 08z/2am radar imagery continues to indicate patchy freezing drizzle across central Illinois: however, the areal coverage and intensity has decreased markedly from earlier in the evening. As light southerly winds flow over the cold/snow-covered ground, expect fog and perhaps some drizzle to persist through the morning. Current visibilities are mostly in the 2-5 mile range, but HRRR suggests the potential for even lower visbys as WAA continues and low overcast lifts. Have seen a few reports of 1/4 mile visbys upstream across central Missouri where clouds have temporarily cleared and expect the fog to thicken/spread northeastward into central Illinois over the next few hours. Will need to carefully monitor trends, as a Dense Fog Advisory could be needed if HRRR verifies. For now, will just mention areas of fog in the forecast through midday. A weak short-wave trough evident on latest water vapor imagery over eastern Nebraska will pass to the W/SW of the area today. A small area of light snow associated with this feature over southwest Iowa will spread across northern Missouri and may approach the far SW CWA toward midday: however, all high-res models show the precip dissipating before arriving. Have therefore gone with a dry forecast. Despite continued southerly flow, fog and extensive cloud cover will keep afternoon high temperatures in the middle to upper 30s. && .LONG TERM...(Tonight through Sunday) ISSUED AT 314 AM CST MON FEB 15 2016 The next fast-moving storm system embedded within the prevailing northwesterly flow aloft will arrive late tonight into Tuesday, bringing another period of wintry precip to central Illinois. 00z Feb 15 models have all trended south with the track of this system, with the NAM being the furthest north and the GEM the furthest south. Have rejected these two solutions in favor of the middle of the road GFS, which takes the 500mb vort max from northern Missouri 12z Tue to far southern Illinois by 18z Tue. Given this particular track, the heaviest precip will be focused across the central/southern CWA. Have therefore reduced PoPs into the chance category along/north of I-74...while maintaining likely further south across the remainder of the area. Another consequence of a further south track is a slightly colder thermal profile. GFS forecast soundings are generally cold enough for snow initially as the max temp in the elevated warm layer only reaches about 1C. As a result, am expecting snow Tuesday morning, gradually transitioning to a rain/snow mix by afternoon as surface temps rise into the middle to upper 30s. Due to the southward track shift, relatively light precip, and marginal temps...snow accumulations are expected to remain minor. Will see a band of around 1 inch along/southwest of a Canton...to Decatur...to Marshall line...with less than one half inch north of I-74. Another weak short-wave will pass through the region on Wednesday: however, this feature will be moisture-starved and will produce little more than some cloud cover. Once this wave exits, upper heights will begin to rise in earnest in response to a major system coming onshore along the Pacific Coast. Downstream ridging across the central and eastern CONUS will allow a pronounced warming trend to occur by the end of the week. Models have been consistently advertising temps reaching the upper 40s and lower 50s by Thursday, then climbing into the upper 50s and lower 60s on Friday. A weak cold front is still progged to pass through Illinois on Friday, but with only limited moisture to work with, will only mention slight chance for showers with FROPA. After that, temps cool a bit over the weekend, but remain above normal in the 50s for both Saturday and Sunday. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) ISSUED AT 1140 PM CST SUN FEB 14 2016 Based on radar trends looks like most of pcpn has moved east of PIA/SPI/BMI, but may still be around DEC and CMI for 2-3 hours, so will have VCSH at those sites. Pcpn type will likely be fzdz, but radar returns are diminishing. IFR cigs will also continue overnight, through the morning and into the afternoon hours. During late afternoon and into the evening hours, looks like cigs could rise to above 1kft and possibly become broken as well. Some uncertainty in what will happen later as models differ on clouds and vis due to high pressure moving in. Winds will be south- southeast through the overnight hours, then become southwest during the morning hours and continue into the afternoon. As high pressure moves into the area, winds will become light and variable. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Auten
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
255 AM CST MON FEB 15 2016 .SHORT TERM...(Today through Wednesday) Issued at 255 AM CST MON FEB 15 2016 Scattered light showers continue to stream northeast just clipping southeastern Todd county Kentucky, but based on the KCKV and KBWG METARs this area should be just above freezing. Will therefore let the Winter Weather Advisory expire as scheduled at 3 AM. Elsewhere across the forecast area, most observation sites have visibilities between 1 and 3 miles with light fog, and a few patches of very light freezing drizzle. Weak, drizzly echoes on radar at Midnight have mostly dried up, so doubt there will be much, if any, additional icing this morning. However, will re- issue an SPS mainly to highlight slick driving conditions through the morning commute. The 00Z WRF and most recent HRRR runs keep the shower activity along the TN border through the morning, and then lift it back up over more of west Kentucky this afternoon before pushing east of the area early this evening. Given this timing, temperatures should be above freezing, so there should be no wintry concerns after the sun gets sufficiently high in the sky this morning. The 00Z models bring a compact, intense upper low into the base of the upper trough over the region on Tuesday. The 00Z consensus keeps any QPF northwest of the area through daybreak, but we will have to watch for the potential for either freezing rain or snow with the onset of precipitation in the morning. Model soundings across the northeast show a warm layer only near the surface, so it is conceivable that we will have to monitor for snow through the day as this system passes. Temperatures should be above freezing, so accumulations will be hard to come by even if the snow reaches the ground. This system should exit to the east at or shortly after 00Z Wednesday. Yet another upper-level disturbance will dive southeast into our region for Wednesday, as we continue to be heavily influenced by cyclonic flow aloft. The models are not generating any precipitation with this activity, but it should keep most of the area rather cloudy. .LONG TERM...(Wednesday Night through Sunday) Issued at 255 AM CST MON FEB 15 2016 By Wednesday into Thursday, we will finally be seeing a shift in the upper level pattern, as an upper level ridge builds overhead. As this occurs, we will see quiet weather along with a decent warmup, that has been advertised for quite a while now. Warm air advection will begin in earnest Wednesday night and the entire area will see 850mb temps back above zero by late Thursday morning or afternoon. We should see highs on Thursday well into the 50s per the latest guidance, 2m temps and soundings. We should see 60s by Friday with our far western counties in SEMO maybe touching or getting close to 70 degrees. In fact, even warmer weather will only be a state away, as newest guidance indicating highs around 80 in northeast Oklahoma. Hard to imagine when you`re currently only sitting at 31 degrees. Meanwhile, in the northern Plains, an upper level shortwave will be moving eastward into the Great Lakes Thursday night into Friday. As this occurs, a weak front at the surface will be moving into our area. Moisture still appears to be rather scant but the GFS still tries to eek out some QPF. Whatever does fall, if anything, will be light. But since POPS have already been taken out, will continue with that idea and leave it dry, but will have to keep watching, as the GFS ensembles continue to indicate a few hundredths of QPF with the FROPA. The front dives south but only makes into the Gulf Coast State before stalling out. Models indicate that the front will lift back north toward the area as early as Saturday night. However, Saturday should be a dry day with temperatures remaining in the 60s. Another weak frontal boundary will develop to our west and will move through on Sunday, which means we will continue with the chance for rain. The front should be exiting the area sometime on Sunday night. Could even see some isolated thunderstorms on Saturday night into Sunday as some of the parameters are hinting at it. && .AVIATION... Issued at 1154 PM CST SUN FEB 14 2016 Main concerns overnight are patchy freezing drizzle and fog. Maintained a mention of freezing drizzle at KPAH and KOWB through 08-09Z, with updates if needed through the rest of the night. IFR and LIFR ceilings and visibilities are also expected through much of Monday morning. Patchy dense fog is also possible, especially at KCGI and KPAH. Improvement in flight conditions will be very gradual through the day. Low pressure moving across the southern states will bring another chance of rain to portions of western Kentucky on Monday, but most of this rain should remain just south of the forecast terminals. Light and variable winds will prevail. && .PAH Watches/Warnings/Advisories... IL...None. MO...None. IN...None. KY...None. && $$ SHORT TERM...DRS LONG TERM...CW AVIATION...RJP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
345 AM CST MON FEB 15 2016 .SHORT TERM... THE NEXT 18 HOURS WILL SEE THE MOST ACTIVE WEATHER EXPECTED FOR THE REMAINDER OF THE ENTIRE WEEK. A STRONG UPPER LEVEL TROUGH IS CURRENTLY DIGGING INTO THE SOUTHERN PLAINS AND TEXAS. THIS TROUGH WILL SLIDE THROUGH THE LOWER MISSISSIPPI VALLEY TODAY AND SHOULD BE WELL EAST OF THE AREA BY LATE THIS EVENING AND TONIGHT. A INCREASINGLY WARM AND BUOYANT AIRMASS HAS ADVECTED INTO THE AREA TONIGHT...WITH TEMPERATURES ACTUALLY WARMING IN MANY SPOTS. THIS WARM AND BUOYANT AIRMASS WILL INTERACT WITH THE RAPIDLY INCREASING OMEGA AND RESULTANT LIFT OVERSPREADING THE REGION TO PRODUCE SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY. AN INITIAL BAND OF CONVECTION THAT IS CURRENTLY FORMING OVER THE NORTHWEST PARTS OF THE CWA IS ASSOCIATED WITH A HIGHLY DIFLUENT FLOW REGIME ALOFT AND A FAVORABLE JET DYNAMICS ASSOCIATED WITH A 100+ KNOT JET STREAK CURRENTLY SLIDING ACROSS THE GULF SOUTH. THIS BAND OF CONVECTION WILL CONTINUE TO MOVE ACROSS THE NORTHERN HALF OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED. A FEW OF THE STORMS COULD BE STRONG...BUT CONDITIONS DO NOT QUITE LOOK PRIMED FOR SEVERE CONVECTION THROUGH AT LEAST MID-MORNING AS CAPE WILL BE SOMEWHAT LIMITED. HEADING INTO THE LATE MORNING AND AFTERNOON HOURS...ANOTHER BAND OF CONVECTION SHOULD PUSH THROUGH THE FORECAST AREA. THIS BAND OF CONVECTION SHOULD FORM ALONG AND JUST AHEAD OF A DRY LINE WHICH IS CURRENTLY FORMING OVER CENTRAL TEXAS. THE DRY LINE SHOULD QUICKLY RACE TO THE EAST AT AROUND THE SAME SPEED AS THE PARENT UPPER LEVEL TROUGH AXIS...AND SHOULD BE MOVING INTO THE ATCHAFALAYA BASIN SOMETIME AROUND NOON BASED ON THE LATEST HRRR GUIDANCE. IT LOOKS LIKE THE STRONGEST FORCING AND GREATEST POTENTIAL FOR CONVECTIVE DEVELOPMENT WILL GENERALLY BE ALONG AND NORTH OF THE I-10 CORRIDOR...AND HAVE THE HIGHEST POPS IN THIS AREA. DYNAMIC FORCING SHOULD BE SLIGHTLY WEAKER SOUTH OF I-10...AND ONLY HAVE CHANCE TO LIKELY POPS FOR THESE AREAS. THE RAIN THREAT SHOULD QUICKLY DIMINISH BY THIS EVENING AS THE DRY LINE PUSHES INTO ALABAMA AND FLORIDA AND STRONG DRY AIR ADVECTION AND SUBSIDENCE OVERTAKES THE AREA. THE SEVERE THREAT SHOULD ALSO BE GREATEST NORTH OF THE I-10 CORRIDOR...WHERE SPEED SHEAR...DIRECTIONAL SHEAR...AND MLCAPE VALUES ARE MAXIMIZED. LAPSE RATES WILL BE QUITE STEEP...AND A LOW WET BULB ZERO HEIGHT OF ONLY 8200 FEET WILL BE FAVORABLE FOR SOME HAIL FORMATION IN THE STRONGEST STORMS. HELICITY VALUES OF 250 M2/S2 OR HIGHER CAN BE EXPECTED THIS AFTERNOON...SO ANY SUSTAINED CONVECTION SHOULD BEGIN TO ROTATE AND TAKE ON SUPERCELL CHARACTERISTICS. THUS...A RISK OF A FEW TORNADOES FORMING WILL ALSO BE PRESENT THIS AFTERNOON AND EVENING. THE ENTIRE AREA SHOULD MOSTLY CLEAR SKIES AND DRY WEATHER IN PLACE BY TOMORROW MORNING...AS DEEP LAYER NORTHWEST FLOW ALOFT AND A STRONG SURFACE RIDGE OVERTAKE THE GULF SOUTH. THIS SAME GENERAL PATTERN SHOULD PERSIST INTO WEDNESDAY AS WELL. NOT MUCH IN THE WAY OF COLD AIR ADVECTION IS EXPECTED WITH THIS RIDGE OF HIGH PRESSURE...SO TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE AVERAGE IN THE 60S AND LOWER 70S BOTH DAYS. OVERNIGHT LOWS WILL COOL INTO THE 40S AND LOWER 50S BOTH NIGHTS. .LONG TERM... HEADING INTO THE LATTER HALF OF THE WEEK...DEEP LAYER RIDGING WILL DEVELOP OVER THE AREA...AS A STRONG UPPER LEVEL HIGH MOVES IN FROM THE SOUTHERN PLAINS AND BECOMES CENTERED OVER THE GULF SOUTH. SINKING AIR THROUGHOUT THE ATMOSPHERIC COLUMN...ALONG WITH A RETURN TO ONSHORE FLOW WILL ALLOW TEMPERATURES TO WARM EVEN FURTHER. HIGHS WILL EASILY CLIMB INTO THE MIDDLE TO UPPER 70S THURSDAY THROUGH SUNDAY...AND OVERNIGHT LOWS SHOULD ONLY DIP INTO THE 50S FOR MOST LOCATIONS. CONDITIONS MAY BE FAVORABLE FOR ADVECTION FOG TO DEVELOP AS DEWPOINTS RISE INTO THE UPPER 50S AND LOWER 60S. THE BIGGEST CAVEAT WILL BE JUST HOW STRONG WINDS ARE DURING THE OVERNIGHT HOURS. IF WINDS FALL TO AROUND 5 TO 10 MPH...ADVECTION FOG COULD BE VERY LIKELY DURING THIS PERIOD. HAVE NOT INCLUDED A MENTION OF FOG IN THE FORECAST YET...DUE TO THE UNCERTAINTY IN PLACE. && .AVIATION... MOST LOCATIONS ARE VFR WITH CIGS AT OR ABOVE SCT-BKN040...EXCEPT OVC010 AT KMCB. CONVECTION DEVELOPING STEADILY FROM KMCB TO KLFT WITH ANOTHER SURGE OF SHOWERS MOVING INTO KBTR. CIGS SHOULD LOWER TO MVFR LEVELS WITH CONVECTION THIS MORNING...THEN BECOMING PREDOMINANTLY MVFR BASED DURING THE AFTERNOON PRIOR TO WIND SHIFT. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR CAVOK SHORTLY AFTER WIND SHIFT FROM WEST TO EAST. 24/RR && .MARINE... SOME GRADIENT RESPONSE THIS MORNING HAS WINDS IN THE 15- 20KT RANGE THIS MORNING. AS THE SURFACE LOW CURRENTLY DEVELOPING OVER EAST TEXAS EJECTS NORTHEAST THIS MORNING...WINDS SHOULD LESSEN TO AROUND 15 KNOTS SUSTAINED WHILE VEERING SOUTHWEST. LOW WILL THEN SLINGSHOT A COLD FRONT INTO THE NORTH GULF THIS EVENING WHICH WILL SWEEP EASTWARD RATHER QUICKLY OVERNIGHT. GRADIENT PRE-FRONTAL APPEARS STRONGER THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION. THIS SHOULD REDUCE THE WINDS TO JUST MODERATE LEVELS TONIGHT AND TUESDAY. WINDS AND SEAS SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES WITH BETTER COLD AIR ADVECTION LATE THURSDAY INTO FRIDAY. 24/RR && .DECISION SUPPORT... DSS CODE....YELLOW. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND MISSISSIPPI RIVER AT RED RIVER LANDING. MARGINAL/SLIGHT RISK OF SEVERE WEATHER MONDAY. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 69 40 71 43 / 90 20 0 0 BTR 72 45 73 45 / 80 20 0 0 ASD 71 44 71 45 / 80 30 10 0 MSY 71 47 68 50 / 70 20 0 0 GPT 68 44 67 45 / 70 40 10 0 PQL 69 40 69 43 / 60 50 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$ 32
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
407 AM EST MON FEB 15 2016 .SYNOPSIS...ARCTIC HIGH PRESSURE WILL CONTINUE TO SLIDE EASTWARD OFFSHORE OVERNIGHT. LOW PRESSURE WILL IMPACT THE REGION MONDAY THROUGH TUESDAY BRINGING SIGNIFICANT WINTRY PRECIPITATION. HIGH PRESSURE BUILDS FOR THE MIDDLE AND LATTER PART OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/...INITIAL BATCH OF WARM AIR ADVECTION PRECIP HAS MOVED OVER THE AREA PRODUCING BETWEEN 1.5 TO 4 INCHES OF SNOW WITH 20 TO 1 SNOW LIQUID RATIOS PER SPOTTER REPORTS. BASED ON RADAR TRENDS AND HRRR THERE COULD BE A LULL IN THE PRECIP OVER THE NRN HALF OF THE FCST AREA THIS MORNING BETWEEN 09Z-12Z BUT SOUTHERN AREAS WILL LIKELY CONTINUE TO SNOW. ADDITIONAL MOISTURE THEN GETS DRAWN NWD MID MORNING THROUGH THE DAY AS LOW PRES OVR THE SRN MS VALLEY BEGINS TO ORGANIZE AND COASTAL FRONT ALONG THE CAROLINAS BEGINS TO MOVE INLAND. WARMER AIR ALOFT WILL BEGIN TO SURGE NWD THIS AFTERNOON WITH A RAPID TRANSITION TO FZRA/PL OVER SRN AREAS AND SNOW MIXING IN WITH ICE PELLETS ALONG THE MASON- DIXON LINE. SFC TEMPS WILL STAY BELOW FREEZING INTO THE EVENING AS MODELS SHOW BROAD SFC RIDGING ALONG THE APPALACHIANS MAINTAINING IN SITU DAMMING. BY MIDNIGHT...LARGE SCALE HEIGHT FALLS AND STRENGTHENING SFC LOW WILL DRAW A BIG SLUG OF MOISTURE INTO THE REGION WHILE COASTAL FRONT MOVES FARTHER INLAND. SFC RIDGING ALONG THE MTNS BEGINS TO WEAKEN AS STRONG PRESSURE FALLS DEVELOP OVER THE AREA WITH COLD AIR BEGINNING TO SCOUR OUT EAST OF THE MTNS. FZRA WILL BEGIN TO CHANGE TO RAIN IN MOST PLACES AFTER MIDNIGHT BUT MAY LINGER LONGER OVER THE NRN SHENANDOAH VALLEY AND WESTERN MD. SEE WSW PRODUCT FOR SPECIFIC SNOW AND ICE AMOUNTS. && .SHORT TERM /TUESDAY/...BY 12Z TUE...SFC LOW IS CROSSING THE APPALACHIANS AND SFC RIDGING IS GONE SUGGESTING EVERYONE SHOULD BE ABOVE FREEZING. HEAVY RAINS EXPECTED THROUGH THE MORNING AS CDFNT CROSSES THE AREA WITH RAIN ENDING FROM WEST TO EAST IN THE AFTERNOON. ONE TO TWO INCHES OF TOTAL QPF EXPECTED FOR THE EVENT WHICH MAY RESULT IN FLOODING ISSUES. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...TUESDAY NIGHT FORECAST REMAINS LOW CONFIDENCE ATTM AS UPPER LEVEL TROUGH AND COMPACT SFC LOW SWING ACROSS THE AREA. QUITE A DIFFERENCE IN QPF PLACEMENT BETWEEN GFS (CENTRAL/SOUTHERN VA) AND THE ECMWF (EASTERN TN). HAVE SLIGHTLY HIGHER POPS ACROSS SOUTHERN TIER...BUT AT CHANCE IN MOST PLACES. THERMAL PROFILES COOLING...SO COULD SEE RAIN/SNOW MIX. WILL HAVE TO WATCH THE TRENDS DURING THIS TIME PERIOD...BUT HIGHEST CONFIDENCE OF LIGHT SNOW ACCUMULATIONS WILL BE IN THE UPSLOPE REGION. MID/UPPER TROUGH REMAINS OVER EASTERN CONUS WEDNESDAY...HOWEVER TEMPERATURES REMAIN NEAR NORMAL. A WEAK COLD FRONT CROSSING LATE WEDNESDAY WILL BRING A SHOT OF CAA ADVECTION AND A CONTINUED CHANCE FOR UPSLOPE SNOW SHOWERS. HEIGHTS THEN RISE FOR THE REMAINDER OF THE WORK WEEK WITH HIGH PRESSURE BUILDING. A WARM FRONT WILL PASS FRIDAY NIGHT WITH A SMALL CHANCE OF SHOWERS...AND THIS WILL LEAD TO A VERY MILD SATURDAY. A COLD FRONT WILL THEN CROSS THE AREA SATURDAY NIGHT...ALTHOUGH THE BULK OF THE FORCING AND MOISTURE STAYS TO THE NORTH. MODEL SPREAD INCREASES BY SUNDAY...ALTHOUGH ATTM IT LOOKS LIKE THE IMMEDIATE REGION WILL BE UNDER THE INFLUENCE OF HIGH PRESSURE. && .AVIATION /09Z MONDAY THROUGH FRIDAY/...IFR CONDITIONS TODAY THROUGH MIDDAY TUE. SNOW TRANSITIONING TO SN/PL AFTER 18Z THEN TO FZRA AFTER 21Z. SFC TEMPS BEGIN TO RISE AFTER 06Z TUE WITH FZRA BECOMING RAIN XCPT PERHAPS AT KMRB. BY 12Z TUE...PRECIP SHOULD HAVE TURNED TO ALL RAIN EVERYWHERE. WILL HAVE TO WATCH WEAK LOW PRESSURE TUESDAY NIGHT/EARLY WEDNESDAY WHICH COULD BRING SOME LIGHT PRECIP...POSSIBLY RASN MIX. OTHERWISE VFR LIKELY THROUGH REMAINDER OF OUTLOOK PERIOD. NW WINDS COULD GUST TO 25 KT WEDNESDAY NIGHT/THURSDAY...WITH S WINDS POTENTIALLY GUSTING TO 25 KT FRIDAY. && .MARINE...SMALL CRAFT ISSUED FOR THE WATERS BEGINNING LATE TONIGHT AND CONTINUING THROUGH TUE AS SRLY WINDS STRENGTHEN IN RESPONSE TO DEVELOPING LOW. PERIODIC...IF NOT NEARLY CONTINUOUS OVER PORTIONS OF THE WATERS...THREAT OF SCA-LEVEL WINDS WILL RUN FROM TUESDAY NIGHT INTO THE FIRST PART OF THE WEEKEND. THE PERIODS OF STRONGEST WINDS WILL OCCUR WEDNESDAY NIGHT AND EARLY THURSDAY (NW) BEHIND A COLD FRONT...THEN IN S FLOW AHEAD OF THE NEXT COLD FRONT FRIDAY INTO SATURDAY...EVENTUALLY BECOMING SW. GALE FORCE WINDS WILL NOT BE TOO FAR ALOFT...BUT MIXING LOOKS POOR ATTM. && .TIDES/COASTAL FLOODING...WATER LEVELS WILL BEGIN TO RISE LATE TONIGHT WITH MINOR COASTAL FLOODING EXPECTED TUE AFTERNOON AT SENSITIVE LOCATIONS. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR DCZ001. MD...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR MDZ003-004- 501-502. WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ013-014- 016-503>506. WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR MDZ005-006- 011-507-508. WINTER WEATHER ADVISORY UNTIL 4 AM EST TUESDAY FOR MDZ017-018. VA...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR VAZ025>031- 036>040-501-503>505-507-508. WINTER WEATHER ADVISORY UNTIL 10 AM EST TUESDAY FOR VAZ050>057- 502-506. WV...WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ050>053- 055-501>506. MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 PM EST TUESDAY FOR ANZ532>534-537-540>543. SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR ANZ530- 531-535-536-538-539. && $$ SYNOPSIS...LFR NEAR TERM...LFR SHORT TERM...LFR LONG TERM...ADS AVIATION...ADS/LFR MARINE...ADS/LFR TIDES/COASTAL FLOODING...LFR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1225 AM EST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 419 PM EST SUN FEB 14 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW DEAMPLIFYING FLOW ACROSS N AMERICA. DEEP TROF THAT WAS OVER SE CANADA/NE CONUS 24HRS AGO IS LIFTING NE...LEAVING BEHIND A BROAD TROF OVER THE CNTRL AND ERN CONUS DOWNSTREAM OF A BROAD RIDGE CENTERED JUST OFF THE W COAST. A VIGOROUS LOOKING SHORTWAVE IS TRACKING ACROSS NRN IL. ASSOCIATED SHIELD OF SNOW HAS PASSED S OF THE AREA TODAY. UPSTREAM...SHORTWAVE TROF OVER MANITOBA/WRN MN WILL BE THE NEXT FEATURE OF INTEREST DURING THE SHORT TERM. MEANWHILE...INCREASING SOUTHERLY FLOW ON THE BACKSIDE OF HIGH PRES NOW OVER THE LOWER LAKES/MID ATLANTIC STATES IS BRINGING LES NORTHWARD OFF LAKE MI UNDER 850MB TEMPS AROUND -16C ACROSS THE N HALF OF THE LAKE PER LATEST RAP ANALYSIS. SATELLITE AND RADAR IMAGERY INDICATE LES HAS NOT BEEN WELL ORGANIZED AS IT LIFTED N INTO THE SE FCST AREA THIS AFTN. THE HEAVIER SNOW HAS IMPACTED MENOMINEE COUNTY...BUT WEB CAMS SUGGEST SNOW ACCUMULATIONS HAVE BEEN UNDER 1 INCH. AFOREMENTIONED SHORTWAVE TROF ACROSS WRN MN WILL SHIFT E...REACHING CNTRL LAKE SUPERIOR/CNTRL UPPER MI AROUND 12Z MON. MODELS ARE IN GOOD AGREEMENT SHOWING A PERIOD OF DEEP LAYER FORCING PER QVECTORS AND A CORRESPONDING INCREASE IN DEEPER MOISTURE AHEAD OF FEATURE. THIS SHOULD YIELD AT LEAST SOME AREAS OF -SN MOVING ACROSS THE FCST AREA TONIGHT. OF MORE INTEREST IS WHAT HAPPENS DOWNWIND OF LAKE MI. WITH 850MB TEMPS OF -13/-14C ACROSS NRN LAKE MI...SYNOPTIC FORCING/DEEPER MOSITURE WILL LEAD TO A PERIOD OF LAKE ENHANCEMENT. IN ADDITION...AS WEAK SFC TROF ASSOCIATED WITH SHORTWAVE MOVES ACROSS THE AREA...THE CONVERGENCE ALONG THE TROF SHARPENS UP AS IT REACHES LAKE MI...LEADING TO A FOCUSING OF THE LAKE ENHANCED SNOW. FCST SOUNDINGS SHOW THE DGZ ENCOMPASSING A VERY DEEP LAYER 9-10FT THICK. WHILE MODELS DON`T SHOW MUCH UPWARD MOTION IN THAT LAYER DUE TO THE OVERALL WEAK SYNOPTIC FORCING...IT WILL STILL HELP FLUFF UP SNOW ACCUMULATIONS. SFC TROF STEADILY CROSSES NRN LAKE MI/SE FCST AREA ROUGHLY DURING THE 09Z-21Z TIME FRAME. STEADY PROGRESSION WILL LIMIT SNOW ACCUMULATIONS...BUT POTENTIAL IS THERE FOR SEVERAL INCHES OF SNOW. FOR NOW...FCST WILL SHOW TOTAL SNOW ACCUMULATION TONIGHT/MON OF 2-3 INCHES WITH LOCAL 4 INCH AMOUNTS FROM MENOMINEE COUNTY INTO LUCE COUNTY...SUB ADVY AMOUNTS. HOWEVER...WILL NEED TO MONITOR THE INCREASE IN ENHANCEMENT ALONG/JUST AHEAD OF THE SFC TROF. SINCE MUCH OF THE SNOW ACCUMULATION WILL OCCUR WITH THIS FEATURE AND OVER A RELATIVELY SHORT PERIOD OF TIME...THE HIGHER SNOWFALL RATES MAY REQUIRE ISSUANCE OF AN ADVY LATER. ELSEWHERE... SNOW ACCMULATIONS SHOULD BE UNDER 1 INCH. WITH PASSAGE OF SFC TROF...-SN WILL END. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 252 PM EST SUN FEB 14 2016 FIRST CHANCE OF ANY SORT OF SIGNIFICANT PRECIP IN THE LONG TERM IS TUE AS A SHORTWAVE MOVES THROUGH AND TURNS LOW LEVEL WINDS NWLY LATER IN THE DAY. 850MB TEMPS DROP TO -15C BY 00Z WED BEHIND THE SHORTWAVE AND MAY DROP A DEGREE OR TWO MORE THROUGH WED MORNING AS WINDS TURN NNW. A SFC RIDGE WILL MOVE IN QUICKLY BEHIND THE SHORTWAVE...BUT MODELS DISAGREE ON HOW FAST. THE 00Z/14 ECMWF HAS THE RIDGE OVER WRN LAKE SUPERIOR BY 18Z AND ERN LAKE SUPERIOR BY 00Z THU...THE 12Z/14 GFS IS ABOUT 6 HOURS SLOWER...OTHER MODELS ARE IN BETWEEN THESE SOLUTIONS. THIS WILL HELP LIMIT ACCUMULATIONS...BUT BEFORE THE LES CUTS OFF WE COULD SEE GENERALLY 3-5 INCHES IN THE NW- NNW WIND SNOWBELTS LATE TUE THROUGH WED (MAINLY THROUGH WED MORNING). ATTENTION THEN TURNS TO LATE IN THE WEEK AS MODELS CONTINUE TO SHOW A STRONG DISTURBANCE MOVING THROUGH...ALTHOUGH MODELS STRUGGLE WITH RUN TO RUN CONTINUITY AND AGREEMENT WITH THE COMPLEX SYSTEM. GENERAL IDEA IS THAT STRONG WAA WILL BEGIN LATE WED NIGHT INTO THU AND CONTINUE UNTIL A SFC LOW AND UPPER SHORTWAVE MOVES THROUGH OR NEARBY LATE FRI INTO FRI NIGHT. AGREE WITH PREVIOUS SHIFT THAT WE COULD SEE A SHORT PERIOD OF SNOW IN THE WAA REGIME BEFORE TEMPS WARM ENOUGH TO SUPPORT ALL LIQUID PRECIP. AFTER THE CHANGE OVER TO LIQUID...COULD SEE A SHORT PERIOD OF FREEZING RAIN (POSSIBLY NON-CONVECTIONAL FREEZING RAIN WHERE SFC AIR IS ABOVE FREEZING BUT ROADS ARE BELOW FREEZING)...BUT THE STRENGTH OF THE SLY FLOW AND WAA SHOULD END THE FREEZING ASPECT OF THE RAIN FAIRLY QUICKLY. GFS SHOWS 0.25-0.5 INCHES OF LIQUID QPF ON FRI...THE ECMWF HAS 0.3-1.0 INCHES...THE GEM HAS SIMILAR AMOUNTS TO THE GFS...BUT DISPLACED SE. COLD AIR SURGES INTO THE ARE BEHIND THE SYSTEM FRI NIGHT...BUT IT DOES NOT LOOK LIKE THERE IS MUCH FORCING FOR PRECIP AT THAT POINT...SO SNOWFALL POTENTIAL ON THE BACK SIDE LOOKS LIMITED...NOT EVEN COLD ENOUGH FOR SIGNIFICANT LAKE EFFECT. VERY LIMITED CONFIDENCE FOR THE WEEKEND...BUT IN GENERAL IT DOES LOOK LIKE COLDER AIR MOVES IN INTO THE MIDDLE OF NEXT WEEK WITH POTENTIAL FOR SOME DISTURBANCES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1224 AM EST MON FEB 15 2016 AN UPPER DISTURBANCE MOVING ACROSS THE UPPER LAKES WILL RESULT IN -SN LATE TONIGHT INTO MON MORNING WITH MVFR CONDITIONS PERSISTING THROUGH MUCH OF THE FCST PD AT ALL TAF SITES. VSBY COULD OCCASIONALLY FALL TO IFR AT KSAW LATE TONIGHT AND EARLY MON MORNING AS ADDITIONAL MOISTURE ADVECTS N OFF LAKE MI. WITH A DOWNSLOPE S WIND AND ABSENCE OF LAKE MI INFLUENCE...KIWD WILL LIKELY SEE THE SHORTEST PERIOD OF -SN OVERNIGHT. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 419 PM EST SUN FEB 14 2016 TIGHTENING PRES GRADIENT BETWEEN HIGH PRES NEAR THE E COAST AND A LOW PRES TROF APPROACHING FROM THE W WILL RESULT IN SOUTHERLY WINDS OF 20-30KT TONIGHT. THE STRONGEST WINDS WILL OCCUR OVER THE E HALF OF THE LAKE WHERE THERE MAY BE A FEW GALE FORCE GUSTS TO 35KT. WINDS WILL DIMINISH MON AS PRES GRADIENT WEAKENS. AFTER A PERIOD OF RELATIVELY LIGHT WINDS UNDER 20KT MON NIGHT/TUE MORNING...PASSAGE OF A COLD FRONT TUE WILL BRING A PERIOD OF STRONGER NORTHERLY WINDS OF 20-30KT. THERE MAY BE A PERIOD OF GALES OVER THE CNTRL PORTION OF THE LAKE TUE NIGHT IN ADDITION TO HEAVY FREEZING SPRAY. WINDS WILL THEN DIMINISH TO UNDER 20KT WED WITH ARRIVAL OF ANOTHER HIGH PRES RIDGE. STRONGER SSE WIND UP TO 30 KTS WILL ARRIVE ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THIS HIGH SHIFTING TO THE E AND ANOTHER APPROACHING LOW PRES. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...TITUS AVIATION...VOSS MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1134 PM CST SUN FEB 14 2016 .UPDATE: Issued at 957 PM CST Sun Feb 14 2016 There may be some patchy freezing drizzle still over parts over south central Illinois this evening. Recent radar trends have been showing returns over this area that as it moves east, and recent runs of the RAP are showing a drying trend at and above 925mb after 06Z, so will carry patchy freezing drizzle until midnight. Otherwise, have been seeing an increase in lowering visibilities over the southern and eastern counties this evening, so went ahead and introduced areas of fog for the rest of the the night. Britt && .SHORT TERM: (Through Late Tonight) Issued at 219 PM CST Sun Feb 14 2016 Most of the snow has shifted east of our forecast area this afternoon as the shortwave was moving eastward into northwest IL. Will keep the winter weather advisory going for parts of west central and southwest IL until 6 pm due to patchy freezing drizzle. The threat for patchy freezing drizzle should end later this evening as the low level stratus cloud deck shifts east of the area. Mid-high level cloudiness will spread back into the area late tonight as another shortwave dives southeastward through the Plains. Went a little colder than MOS temperature guidance for tonight due to the new snow cover over much of the area. Rest of the forecast still looks on track. GKS .LONG TERM: (Monday through Next Sunday) Issued at 219 PM CST Sun Feb 14 2016 A shortwave and an associated surface low will pass south of our area on Monday. Precipitation with this feature should remain south of the forecast area, but the GFS model does generate a few areas of light QPF over our region on Monday. Could not rule out some patchy light rain/snow over our area on Monday. Temperatures will be noticeably warmer on Monday, finally getting well above the freezing mark for much of the area after a cold weekend. A strong northwest flow shortwave and associated weak surface low will be dropping southeastward through our area late Monday night and Tuesday bringing another shot of rain/snow to the area. The NAM and GFS models are similar in generating most of their QPF across northeast MO and west central and southwest IL, but the ECMWF model continues to have a more southwest track to the weather system and has most of its QPF west of the Mississippi River. For now will lean toward the NAM and GFS model solutions and put my highest pops over northeast MO and west central and southwest IL. Although temperatures will be fairly warm again on Tuesday there will be the potential for a little accumulating snow late Monday night and Tuesday morning across northeast MO and west central IL. The models continue to depict unseasonably warm and windy conditions for the end of the work week as an upper level ridge moves over the region on Thursday, along with strong south- southwesterly winds due to a tight surface pressure gradient over our area ahead of a low pressure system moving eastward through the northern Plains. Our next chance of measurable rain should occur mainly Saturday night as a weak low pressure system moves eastward through southern portions of MO and IL. GKS && .AVIATION: (For the 06z TAFs through 06z Monday Night) Issued at 1118 PM CST Sun Feb 14 2016 Expect that VFR conditions currently over the St. Louis area terminals is only temporary, and that MVFR and IFR conditions will redevelop back over the next 1-3 hours. Expect these same conditions to persist at KUIN and KCOU through mid morning before improving through the day. There will be a weak storm system move through the area that may bring some light rain or snow to the area during the day...but chances are so low that I will not include in the TAF at this point. Specifics for KSTL: Expect current VFR conditions to be only temporary before MVFR and possibly IFR conditions move back into the terminal in the next 1-3 hours. These conditions will persist through mid morning before they improve back to VFR. There will be a weak storm system move through the area that may bring some light rain or snow late in the morning or during the afternoon...but chances are too low to include in the TAF at this time. An additional chance of rain or snow will occur late on Monday night...but here again...chances are not high enough this far out to include in the TAF. Britt && .LSX WATCHES/WARNINGS/ADVISORIES: MO...NONE. IL...NONE. && $$ WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1105 PM CST SUN FEB 14 2016 .UPDATE... ISSUED AT 825 PM CST SUN FEB 14 2016 RADAR INDICATES SOME LIGHT TO MODERATE SNOW SHOWERS CROSSING SOUTHWEST NEBRASKA AND SATELLITE CLOUD TEMPERATURES OF -41C INDICATE THAT THERE IS SOME VERTICAL EXTENT...THUS WE HAVE UPDATED TO INCLUDE A LITTLE MORE THAN SPRINKLES/FLURRIES. STILL...BECAUSE THE SHOWERS ARE MOVING QUICKLY...ACCUMULATIONS WILL BE MINIMAL. UPDATE ISSUED AT 747 PM CST SUN FEB 14 2016 TEMPERATURE TRENDS IN THE PLATTE RIVER VALLEY AND PARTS OF THE SANDHILLS ARE SIGNALING TEMPERATURES A LITTLE COLDER THAN CURRENTLY FORECAST. WE HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR THE TRENDS AND THE INDICATIONS IN THE STATISTICAL OUTPUT. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 THE MAIN FORECAST CHALLENGE THROUGH MONDAY AFTERNOON IS PRECIPITATION. A MID LEVEL SHORTWAVE AND A SURFACE TROUGH WILL TRAVERSE THE FORECAST AREA LATE THIS EVENING WHILE ANOTHER SYSTEM APPROACHES NORTHWEST NEBRASKA MONDAY AFTERNOON. THIS EVENING AND TONIGHT...THE 12Z MODEL SUITE ALONG WITH HRRR AND RAP GENERALLY AGREE WITH PREVIOUS FORECAST PACKAGE...SO MADE MINOR ADJUSTMENTS TO PRECIPITATION AND TEMPERATURES. WEAK RADAR ECHOES OVER PARTS OF NORTHERN NEBRASKA AND THE PANHANDLE TODAY HAVE BEEN THE RESULT OF MID LEVEL CLOUDS AND VIRGA...VERIFIED BY WEB CAMERAS AND SURFACE OBS. THE GFS...ECM...AND NAM SHOW SUFFICIENT 500-700 HPA FRONTOGENESIS ACROSS THE FORECAST AREA THIS EVENING...BUT FORECAST SOUNDINGS INDICATE CONTINUED LOW LEVEL DRY AIR...ESPECIALLY ACROSS SOUTHWEST NEBRASKA. THE RAP AND NAM BRING SATURATION AS LOW AS 850HPA ACROSS THE NORTH WHILE THE HRRR SHOWS SCATTERED LIGHT SHOWERS NORTH AND FAR SOUTHWEST. DESPITE THE DRY AIR IN THE SOUTH...RAP FORECAST SOUNDINGS SUGGEST AMPLE LOW LEVEL LIFT TO SUPPORT A LIGHT SHOWER IF EVAPORATIVE COOLING OCCURS. KEPT SCHC MENTION GENERALLY ACROSS THE NORTHERN THIRD OF THE FORECAST AREA AND SPRINKLES/ FLURRIES FOR THE REMAINDER. THE TEMPERATURE PROFILE GENERALLY SUPPORTS RAIN AS 0-2KFT AGL TEMPS AND SFC WET BULB REMAIN ABOVE FREEZING. HOWEVER...DID MENTION RASN AFTER 03Z AS SATURATION AND LIFT OCCUR IN THE DGZ. MOST OF THE FORCING AND LOW/MID LEVEL MOISTURE MOVE EAST AFTER 06Z WHEN ALL SNOW WOULD BE BETTER SUPPORTED. KEPT MIN TEMPS ABOVE MOS GUIDANCE TO ACCOUNT FOR CLOUDS...850HPA TEMPS ABOVE 0C...AND WINDS STAYING NEAR 10 KTS. MONDAY...TRENDED MAX TEMPS UP A DEGREE OR TWO TO FOLLOW THE ECM AND MAV MORE CLOSELY. DESPITE INCREASING CLOUD COVER THROUGH THE DAY...WAA AT 850HPA AND DOWNSLOPING WINDS SHOULD OVERCOME. THE NEXT WAVE OF MOISTURE ENTERS NORTHWEST NEBRASKA EARLY AFTERNOON...BUT LOW LEVEL DRY AIR MAY HANG ON THROUGH LATE AFTERNOON OR EARLY EVENING. ISENTROPIC LIFT IS MORE EVIDENT WITH THIS SYSTEM...ESPECIALLY ACROSS THE NORTH. INCLUDED SCHC AS EARLY AS 18Z FAR NORTHWEST...BUT BETTER CHANCE OCCURS AFTER 00Z AS LOW LEVEL MOISTENING AND LIFT INCREASE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 316 PM CST SUN FEB 14 2016 MONDAY NIGHT THROUGH WEDNESDAY...A FAIRLY POTENT UPPER LEVEL DISTURBANCE NEAR OR JUST OVER THE COAST OF CNTL BRITISH COLUMBIA WILL MOVE RAPIDLY THROUGH THE MISSOURI BASIN MONDAY NIGHT. THE PTYPE IS RAIN SHOWERS AS THE FCST AREA WILL BE ON THE SRN OR WARM SIDE OF THE DISTURBANCE. LOWS TUESDAY MORNING FALL INTO THE LOWER 30S. COOLING ALOFT COULD PERHAPS PRODUCE A MIX BUT THE PREDOMINATE PTYPE IS RAIN. THE MORNING RUN OF THE ECM SHOWS SHOWERS AS FAR SOUTH AS INTERSTATE 80 WITH THIS SYSTEM. THE MODEL CONSENSUS IS ALONG OR NORTH OF NEBRASKA HIGHWAY 2. THE ECM SHOWS MUCH MORE ROBUST 700-500MB MOISTURE BUT VERY MODEST SATURATION IN THE 850-700MB LAYER. THE THREE GUIDANCE DATA SETS ARE VERY CLOSE FOR HIGHS TUESDAY IN THE LOWER 40S TO MID 50S. SOME MIDLEVEL COOLING IN THE MORNING WILL HAVE TO BE OVERCOME. H850MB TEMPERATURES SHOULD RISE TO 0C TO 8C BY LATE AFTERNOON. A MIX OF SUN AND CLOUDS WAS INDICATED IN THE MODELS. THERMAL RIDGING CONTINUES TO BUILD TUESDAY NIGHT AND WEDNESDAY WITH H850MB TEMPERATURES RISING TO 5C TO 10C. THIS SUPPORTS LOWS IN THE UPPER 20S TO LOWER 30S AND HIGHS IN THE 50S TO NEAR 60. GENERALLY CLEAR SKIES ARE EXPECTED DURING THIS TIME. SOME HIGH CIRRUS MAY BE OVERHEAD IN THE AFTERNOON. WEDNESDAY NIGHT THROUGH SUNDAY...THURSDAY IS THE BIG DAY. WEST- SOUTHWEST WINDS ARE UNIDIRECTIONAL TO 700MB AND H850MB TEMPERATURES RISE TO 15C TO 20C. HIGHS WILL EASILY RISE INTO THE 60S. THE GFS AND ECM SHOW A LONG WAVE TROF FLUSHING WARM AIR ACROSS THE ROCKIES AND INTO THE CNTL PLAINS. HIGH CLOUDINESS ASSOCIATED WITH A BAROCLINIC LEAF POSITIONED ACROSS THE NRN PLAINS AND MIDWEST COULD PLACE THE FCST AREA IN NEARLY FULL SUN. LATER FORECASTS MAY RAISE HIGHS A BIT. A BLEND OF GUIDANCE PLUS BIAS CORRECTION WAS THE BASIS FOR THE TEMPERATURE FORECAST. A KINK SHOWED UP IN THE FORECAST THURSDAY NIGHT ASSOCIATED WITH A PACIFIC COLD FRONT FRIDAY. 700MB WINDS INCREASE TO 60 TO 75 KTS AHEAD OF THE FRONT IN THE ECM AND GFS. COUPLED WITH A PV1.5 ANOMALY AND 6 HR PRESSURE RISES OF 12-16MB...A PERIOD OF STRONG OR HIGH WIND GUSTS COULD DEVELOP THURSDAY NIGHT. LATER FORECASTS WILL MONITOR THIS POTENTIAL WIND EVENT. LOW PRESSURE TRACKS INTO THE UPPER MIDWEST FRIDAY AND THIS SHOULD SEND A PACIFIC COLD FRONT THROUGH THE FCST AREA. H850MB TEMPERATURES COOL TO 5C TO 10C SUPPORTING HIGHS IN THE 50S TO AROUND 60. DOWNSLOPING WEST NORTHWEST WINDS NEAR 25 TO 30 MPH WILL CONTINUE TO SUPPORT DEEP VERTICAL MIXING. ZONAL FLOW ALOFT IS IN PLACE SATURDAY AND A NEW SFC LOW FORMS ON THE NRN HIGH PLAINS. NO SIGNIFICANT WARMING OR COOLING IS SHOWN AT H850MB BUT WEAK WINDS SUGGEST A SHALLOWER MIXING HEIGHT. THE FORECAST FOR HIGHS IN THE 50S WOULD APPEAR THE BEST FIT. SOME SORT OF COLD FRONT IS SHOWN BY THE GFS...ECM AND GFS ENSEMBLE SATURDAY NIGHT COOLING HIGHS INTO THE 40S TO AROUND 50 SUNDAY. THE MODELS ARE IN GOOD AGREEMENT WITH A DOUBLE BARREL HIGH PRESSURE SYSTEM OVER SCNTL CANADA AND THE CNTL ROCKIES. THIS WOULD PUT THE BRAKES ON ANY SORT ARCTIC AIR AS THE MILDER PACIFIC HIGH ACROSS THE ROCKIES DOMINATES THE COLDER ARCTIC AIR. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1105 PM CST SUN FEB 14 2016 VISUAL METEOROLOGICAL CONDITIONS ARE FORECAST THROUGH TONIGHT IN CENTRAL AND WESTERN NEBRASKA. AFTER 14Z...CEILING WILL BECOME UNLIMITED UNTIL MIDDLE CLOUDS MOVE IN AGAIN LATE AFTERNOON. WIND IS EXPECTED TO BECOME 270-300 AT 10-14KT AND BECOME GUSTY IN NORTHERN NEBRASKA AFTER 02Z. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SPRINGER SHORT TERM...SNIVELY LONG TERM...CDC AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
108 AM EST MON FEB 15 2016 .SYNOPSIS... BITTER COLD TEMPERATURES WILL BE WITH US AGAIN TONIGHT, BUT SHOULD RELAX, STARTING ON MONDAY. HOWEVER, AN APPROACHING STORM SYSTEM WILL ALSO BRING A WINTRY MIX OF PRECIPITATION, BEGINNING MONDAY EVENING. RAIN AND MILDER TEMPERATURES WILL FOLLOW FOR MOST OF THE AREA ON TUESDAY. && .NEAR TERM /UNTIL 8 AM THIS MORNING/... 910 PM UPDATE.. LIKE LAST NIGHT, TEMPERATURES ARE PROVING TO BE THE TOUGHEST NUT TO CRACK IN THE OVERNIGHT FORECAST. TEMPERATURES PLUMMETED AFTER SUNSET, FORCING US TO SIGNIFICANTLY LOWER THE MINIMUMS IN MANY LOCATIONS. HOWEVER CIRRUS IS INCREASING FROM THE SOUTHWEST, WHICH SHOULD SLOW THE FALL OF TEMPERATURES. I LEANED HEAVILY ON A COMBINATION OF HRRR AND RAP TEMPERATURES FOR THE INITIAL GRID POPULATION. THEN I MADE ADJUSTMENTS BASED ON CURRENT OBS. EITHER WAY, THE MORNING MINIMUMS WILL SHOW HUGE VARIABILITY FROM SITE TO SITE. 4PM UPDATE... LE SNOW SHOWERS CONTINUE OVER THE FINGER LAKE REGION THIS AFTERNOON AND ARE EXPECTED TO QUICKLY WEAKEN OVER THE NEXT COUPLE OF HOURS. AROUND 2-3 INCHES OF SNOW HAS FALLEN NEAR ITHACA FROM THE LE BAND SO FAR TODAY... AND EXPECT VERY LITTLE ACCUMS FOR THE REMAINDER OF THE DAY. TEMPS ARE RISING QUICKLY FROM OUR BRUTAL TEMPS THIS MORNING AND MOSTLY SUNNY ARE DOMINATING THE REGION. 850MB TEMPS ARE UP TO AROUND -21... AND EXPECT THESE TO CONTINUE TO RISE TODAY. HIGH TEMPS FOR TODAY ARE STILL EXPECTED TO BE IN THE SINGLE DIGITS. && .SHORT TERM /8 AM THIS MORNING THROUGH TUESDAY NIGHT/... 915 PM UPDATE... ONE MINOR UPDATE: WE ADDED FLURRIES TO THE FORECAST FOR MUCH OF THE REGION, BEGINNING MID-MORNING. THE NAM AND GFS BOTH GENERATE LIGHT PRECIPITATION UNDER A FAST MOVING SHORT WAVE. WE ALSO MADE SMALL CHANGES TO THE MONDAY MORNING AND AFTERNOON QPF/SNOW FIELDS. 4 PM SUNDAY UPDATE... A COMPLICATED AND POTENTIALLY HIGH IMPACT SYSTEM IS STILL SLATED TO MOVE IN LATER MON-TUE. THE LARGE-SCALE FLOW PATTERN CONTINUES TO SUGGEST A HIGH LIKELIHOOD OF HEAVY PRECIPITATION AMOUNTS, AS BOTH THE ATLANTIC AND GULF OF MEXICO ARE WIDE OPEN FOR INPUT. MODEL CONSENSUS HAS IMPROVED WITH TODAY`S 12Z RUNS, AS THE EXPECTED SURFACE LOW TRACK IS NOW PROJECTED FROM WRN/CNTRL VA- CNTRL PA-ERN NY-QUE LATER MON-TUE. AS SUCH, CONFIDENCE HAS ALSO INCREASED THAT A SWATH OF HEAVY PRECIPITATION WILL IMPACT AT LEAST PORTIONS OF THE FORECAST AREA, MOST LIKELY OUR NORTHERN AND WESTERN ZONES. QUESTIONS STILL EXIST AS TO THE EXACT THERMAL STRUCTURE AND PTYP. HOWEVER, GIVEN THE JUST DISCUSSED BETTER AGREEMENT WITH THE SURFACE AND MID-LEVEL FEATURES, WE HAVE ENOUGH CONFIDENCE TO GO WITH A WINTER STORM WATCH IN OUR FAR NORTHERN AND WESTERN ZONES (STEUBEN, YATES, NORTHERN SENECA, CAYUGA, NORTHERN ONONDAGA, AND NORTHERN ONEIDA COUNTIES), WHERE SNOW/ICE POTENTIAL IS THE GREATEST. ELSEWHERE, AN INITIAL SHOT OF THERMAL ADVECTION FORCED SNOW, AND PERHAPS SOME FREEZING RAIN, SHOULD MOVE IN BETWEEN 21Z MON AND 00Z TUE, PERSISTING A GOOD PART OF MON NIGHT. GIVEN EXPECTED AMOUNTS (2-5" OF SNOW AND MAYBE A THIN ICE COATING), ADVISORIES WERE MORE APPROPRIATE, AND HAVE LIKEWISE BEEN ISSUED. WINTER PTYP ISSUES ARE NOT THE ONLY CONCERN, BY A LONG SHOT. GIVEN A DEEP SOUTHERLY FLOW OF WARM, MOIST AIR ALONG AND EAST OF THE SURFACE LOW TRACK, PARTS OF OUR FORECAST AREA LOOK TO BE IN LINE FOR A PERIOD OF HEAVY RAIN ON TUE. ALTHOUGH A BIT TOO EARLY TO PINPOINT EXACT AMOUNTS, RAINFALL TOTALS OF 1-2" IN 6-12 HRS ARE NOT OUT OF THE REALM. GIVEN THE FROZEN IMPERVIOUS GROUND SURFACE THIS TIME OF YEAR, SUCH RAINFALL TOTALS COULD BE PROBLEMATIC. THIS HAS BEEN HINTED AT IN RECENT ENSEMBLE MODEL OUTPUT FOR POTENTIAL RIVER/TRIBUTARY RESPONSES TO SAID RAINFALL. ALTHOUGH NO FLOOD WATCHES HAVE YET BEEN POSTED, WE ARE NO DOUBT WATCHING THIS SITUATION CLOSELY, AND WILL CONTINUE TO DO SO. THINGS FINALLY BEGIN TO WIND DOWN TUESDAY NIGHT, AS THE MAIN DYNAMIC LOW TRACKS UP THROUGH EASTERN CANADA. A WEAKER SURFACE LOW AND ASSOCIATED SHORT-WAVE COULD BRING SOME LIGHT SNOWFALL LATER TUE NIGHT. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... 442 PM UPDATE... VERY LITTLE ARCTIC AIR REMAINS OVER CENTRAL AND SOUTHERN CANADA WHEN THE LONG TERM PERIOD BEGINS. A LARGE SCALE WARMING TREND IS FORECAST ACROSS MUCH OF THE U.S., INCLUDING THE NORTHEAST. AN EXITING COLD FRONT WILL BRING A FEW RAIN OR SNOW SHOWERS TO THE REGION ON WEDNESDAY. AFTER A DRY THURSDAY AND EARLY FRIDAY, A POWERFUL STORM SYSTEM OVER THE PLAINS WILL DRAG WARM, MOIST AIR TOWARD NY/PA LATE FRIDAY INTO SATURDAY. THE RESULT WILL BE RAIN, POSSIBLY MIXED WITH SNOW SHOWERS OVERNIGHT AND EARLY IN THE MORNING. TEMPERATURES WILL REMAIN MILDER THAN NORMAL AFTER THE COLD FRONT PASSES LATE SATURDAY. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR THROUGH THE NIGHT...THOUGH FEW-SCT CLOUDS WILL SKIM ACROSS ABOVE 20 KFT AGL. HOWEVER...MODELS ARE STARTING TO CATCH ON THAT THE WAVE CURRENTLY IN THE SOUTHWESTERN GREAT LAKES REGION...WILL DRIFT WSW-TO-ENE THROUGH OUR AREA MONDAY MORNING INTO EARLY AFTERNOON WHILE WEAKENING. THE PROBLEM IS THAT THE LOWEST 12 KFT OF THE ATMOSPHERE WILL BE AT IDEAL TEMPERATURES FOR SNOW CRYSTAL PRODUCTION...SO DESPITE LIMITED MOISTURE AND LIFT...IT WILL PROBABLY BE ENOUGH TO BRING FLURRIES/FINE LIGHT SNOW THROUGH THE TERMINALS. FOR KITH-KELM-KAVP-KBGM...THIS WILL LIKELY RESULT IN AT LEAST MVFR VIS AND PERHAPS EVEN IFR VIS AT TIMES. MORE CONFIDENT IN IFR OCCURRING FOR KBGM SO I INCLUDED A TEMPO GROUP. LARGER AMOUNT OF DRY AIR TO OVERCOME FOR KSYR-KRME SO RESTRICTIONS NOT PROBABLE THERE. OTHER THAN THE VERY LIGHT SNOW FROM THAT WAVE...FAIRLY QUIET UNTIL LARGE STORM SYSTEM BEGINS MOVING IN FROM THE SOUTH. CONDITIONS AT KAVP SHOULD START DETERIORATING 20Z ONWARD AS INITIAL SHIELD OF SNOW MOVES IN...SOON TO BE FOLLOWED BY KBGM AROUND 00Z...AND REMAINDER OF TERMINALS MONDAY NIGHT. A CHANGE TO A WINTRY MIX OF A FEW ICE PELLETS OR MAINLY FREEZING RAIN EXPECTED AROUND 02Z KAVP, AND TOWARD 05Z/06Z KITH/KBGM/KELM. WINDS THIS TAF PERIOD WILL BE VARIABLE TO LIGHT SE OVERNIGHT...THEN SE OR S 8-12 KTS MONDAY. .OUTLOOK... TUE...RESTRICTIONS IN SNOW OR WINTRY...BECOMING MAINLY RAIN TUE. TUE NGT...ADDITIONAL RESTRICTIONS AS RAIN QUICKLY CHANGES BACK TO SNOW ON BACK END OF DEPARTING STORM. WED...WEAK CLIPPER COULD CAUSE BRIEF RESTRICTIONS IN SCT -SHSN. THU-EARLY FRI...VFR. LATE FRI-FRI NGT...WARM FRONT END OF SYSTEM MAY MOVE IN WITH MIXED PRECIPITATION AND POSSIBLE RESTRICTIONS. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR PAZ038>040-043-044-047-048-072. NY...WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 7 AM EST TUESDAY FOR NYZ023>025-036-037-044>046-055>057-062. WINTER STORM WATCH FROM THIS AFTERNOON THROUGH TUESDAY EVENING FOR NYZ009-015>018-022. && $$ SYNOPSIS...MLJ NEAR TERM...DJP/KAH SHORT TERM...DJP/MLJ LONG TERM...DJP AVIATION...HEDEN/MDP
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
339 AM CST MON FEB 15 2016 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CST MON FEB 15 2016 FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE BLEND FOR NOW. A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF CLOUD COVER. NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST SW OF THE FA. FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING COOLER TEMPERATURES TO THE REGION TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CST MON FEB 15 2016 NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO. HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY. WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD. THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID- LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER AIR FEATURES. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1146 PM CST SUN FEB 14 2016 IFR CIGS EAST OF THE RED RIVER VALLEY...STILL HAVE SOME LIGHT FOG AND FREEZING DRIZZLE IN SPOTS. MAIN ISSUE IS CLEARING TREND INTO THE RED RIVER VALLEY AND IF OR WHEN WILL IT OCCUR AND ANY FOG IF IT DOES CLEAR. SO CONFIDENCE IS LOWER THAN USUAL. OVERALL BROUGHT IN VFR CIGS TO DVL/GFK/FAR PAST 12Z MON. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ SHORT TERM...VOELKER LONG TERM...MAKOWSKI/VOELKER AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1218 AM CST MON FEB 15 2016 .UPDATE... ISSUED AT 1217 AM CST MON FEB 15 2016 VISIBILITIES IN THE JAMES BASIN HAVE VARIED FROM 1/4 MILE TO 6+ AND WILL KEEP THE MENTION OF AREAS OF FOG THERE WITH PATCHY DENSE FOG. LIGHT FOG POSSIBLE FARTHER WEST TOWARDS BISMARCK AND MINOT AS PER HIGHRES MODELS. OTHERWISE ONLY MINOR CHANGES IN HOURLY TEMPERATURE TRENDS. UPDATE ISSUED AT 903 PM CST SUN FEB 14 2016 NORTH DAKOTA DOT WEBCAMS SHOWING SCATTERED AREAS OF FOG FORMING AT ASHLEY...DUNSEITH...KULM AND PETTIBONE. ALSO SEEING FOG AT JAMESTOWN AND HARVEY AIRPORTS. ALTHOUGH THERE WILL BE SOME VARIABILITY IN VISIBILITY AS IS TYPICAL...READY TO GO WITH AREAS OF FOG JAMES RIVER VALLEY NORTH THROUGH RUGBY AND DUNSEITH AND PATCHY FOG TO THE WEST INTO THE MISSOURI AND PORTIONS OF THE SOURIS RIVER VALLEYS. WILL MONITOR FOR ANY DENSE FOG ADVISORIES NEEDED BUT NOT AT THIS TIME. UPDATE ISSUED AT 557 PM CST SUN FEB 14 2016 MAIN CHALLENGE THIS EVENING WILL BE TIMING THE FOG DEVELOPMENT ACROSS CENTRAL NORTH DAKOTA. ABUNDANT LOW LEVEL MOISTURE FROM MELTING SNOW AND CLEARING SKIES WILL SET UP THE BOUNDARY LAYER FOR FOG FORMATION. CURRENTLY HAVE AROUND 9 PM AS THE START TIME FOR PATCHY FOG. WILL KEEP THAT FOR NOW. WILL ALSO WATCH FRO DENSER FOG POSSIBILITIES AS THE NIGHT PROGRESSES. THIS WILL DEPEND ON THE AMOUNT OF MID/HIGH CLOUDS REMAIN. THE PRECIP ACROSS THE SOUTHWEST HAS ENDED/MOVED OUT OF THE AREA. CURRENT FORECAST TRACKING WELL SO FAR. && .SHORT TERM...(THIS EVENING THROUGH MONDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 MILD WEATHER WILL CONTINUE THROUGH MONDAY...WITH SOME PATCHY FOG POSSIBLE TONIGHT OVER CENTRAL ND AND AN INCREASING CHANCE OF LIGHT RAIN OR SNOW OVER WESTERN AND CENTRAL ND MONDAY AFTERNOON. FIRST OF ALL...WE HAVE REMOVED ANY MENTION OF FREEZING DRIZZLE IN THE FORECAST FOR THE REMAINDER OF THE AFTERNOON GIVEN THE LACK OF OBSERVATIONAL EVIDENCE OF IT OVER EAST CENTRAL ND THROUGH 21 UTC. FORECAST SOUNDINGS IN PLACES LIKE JAMESTOWN SHOW THE STRATUS DECK /LOW CLOUDS/ BEING WARMER THAN -12 C...WHICH SUPPORTS SUPERCOOLED LIQUID DROPS AND NOT ICE CRYSTALS...BUT OMEGA IN THAT LAYER IS ON ITS WAY DOWNWARD AND SO THE PROBABILITY OF FREEZING DRIZZLE WILL ONLY LOWER THROUGH THE REST OF THE DAY. TONIGHT...WE ADDED PATCHY FOG TO THE FORECAST OVER CENTRAL ND OUT OF RESPECT TO SNOWMELT TODAY...INITIALLY-LIGHT WINDS WITHIN 1000 FT OF THE GROUND...AND SIMULATION OF ITS DEVELOPMENT IN THE 15-19 UTC RUNS OF THE OPERATIONAL AND EXPERIMENTAL HRRR AND THE 12 UTC NAM-NEST. HOWEVER...FORECAST SOUNDINGS SUGGEST THE LOW LEVELS MAY BECOME A BIT TOO TURBULENT FOR FOG IN MOST AREAS AFTER 09 UTC PER INCREASING WESTERLY WINDS JUST ABOVE THE GROUND...WHICH PRODUCES MODIFIED RICHARDSON NUMBERS GREATER THAN 0.00. OTHERWISE...WE ARE EXPECTING A RELATIVELY MILD NIGHT WITH LOWS IN THE 20S F...AND IT SHOULD BE DRY AFTER ANY LATE-AFTERNOON SHOWERS IN SOUTHWESTERN ND DISSIPATE AS A WEAK SHORTWAVE TROUGH CONTINUES INTO SD. ON MONDAY...THE 12 UTC GFS...ECMWF...AND NAM ALL SHOW A SHORTWAVE TROUGH MOVING INTO WESTERN ND BY AFTERNOON. THAT WAVE CAN BE SEEN CRASHING ONTO THE CENTRAL BRITISH COLUMBIA COASTLINE ON AFTERNOON MOISTURE CHANNEL IMAGERY...AND GIVEN ITS APPARENT CIRCULATION AND POST-TROUGH DARKENING ON THOSE SATELLITE IMAGES...MODEL GUIDANCE APPEARS VERY REASONABLE IN SHOWING A MODERATE TO POSSIBLY STRONG SURGE OF QG-FORCING CROSSING THE AREA BEGINNING MONDAY AFTERNOON. WE ARE THUS ADVERTISING POPS OF 40+ PERCENT OVER MOST OF WESTERN AND CENTRAL ND MONDAY AFTERNOON. PRECIPITATION TYPE WILL LIKELY BE DRIVEN MAINLY BY BOUNDARY LAYER TEMPERATURES AS THE WARM LAYER ALOFT WILL INITIALLY BE SUB-SATURATED IN SOUTHWEST ND /PROMOTING WET BULB COOLING/...AND TOO COLD FOR MELTING ALOFT ELSEWHERE WITH 850-MB TEMPERATURES BELOW 1 C. WE THUS HAVE A MIX OF RAIN AND SNOW IN THE FORECAST ACROSS THE AREA...WITH QPF FROM 18 TO 00 UTC OF 0.10 INCHES OR LESS PER THE 12 UTC MODEL SUITE. .LONG TERM...(MONDAY NIGHT THROUGH SUNDAY) ISSUED AT 330 PM CST SUN FEB 14 2016 ACTIVE FLOW REMAINS OVER THE REGION FOR THE EARLY PORTION OF THE WEEK...THEN WE FINALLY TRANSITION TO A MORE PROGRESSIVE FLOW PATTERN FOR THE REMAINDER OF THE LONG TERM PERIOD. MODELS TRENDING STRONGER WITH A S/WV TROUGH/CLIPPER SYSTEM MOVING ACROSS THE NORTHERN PLAINS MONDAY AND MONDAY NIGHT. PRECIPITATION TYPE BY MONDAY EVENING SHOULD BE ALL SNOW WITH MODELS IN AGREEMENT WITH CAA LOWERING TEMPERATURES ALOFT TO BELOW FREEZING THROUGH THE SATURATION LAYER. MAY SEE SOME LIGHT ACCUMULATIONS WITH THIS WAVE GIVEN THE UPTICK IN QPF AND LIFT. CURRENT THINKING IS THAT THIS WILL REMAIN SUB-ADVISORY TYPE SNOWFALL SO DID NOT MENTION IN THE HWO WITH THIS FORECAST ISSUANCE. THIS CLIPPER IS QUICKLY FOLLOWED BY ANOTHER WEAKER WAVE TUESDAY THROUGH EARLY WEDNESDAY. THERMAL PROFILE SUGGEST ALL SNOW WITH THIS S/WV. BROAD UPPER LEVEL RIDGING WILL DRY THINGS OUT TOWARDS THURSDAY ALONG WITH MILD/WELL ABOVE NORMAL TEMPERATURES IN THE 30S EAST...40S NORTHWEST AND CENTRAL...AND MID/UPPER 50S OVER THE SOUTHWEST. A GOOD SOUTHERLY RETURN FLOW WILL INCREASE MIXING AND MAY LEAD TO EVEN WARMER DAYTIME HIGHS FOR THURSDAY THAN WHAT IS CURRENTLY FORECAST. FOR NOW LEANED MORE CONSERVATIVE. UPPER LEVEL S/WV TROUGH FOLLOWS THE RIDGE THURSDAY NIGHT/FRIDAY. MODEL SPREAD STILL HIGH RIGHT NOW IN REGARDS TO THIS WAVE. MAY SEE SOME IMPACTFUL WEATHER THOUGH ASSOCIATED WITH THIS TOWARDS THE END OF THE WEEK...RIGHT NOW VERY UNCERTAIN BUT WILL BE WORTH KEEPING AN EYE ON. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT) ISSUED AT 1217 AM CST MON FEB 15 2016 FOG CONTINUED IN THE JAMES RIVER VALLEY. LATEST ITERATIONS OF SHORT TERM MODELS SUPPORT CONTINUED FOG THIS MORNING WITH VSBYS OF 1/4SM TO 3/4SM THROUGH 12Z...THEN IMPROVING AFT 12Z AS SOUTHWEST WINDS...THEN WEST WINDS DEVELOP. MODELS ALSO HINTING AT LIGHT FOG POSSIBLE AT KBIS-KMOT WITH VSBYS AROUND 3SM. VFR AT KISN-KDIK UNTIL MONDAY AFTERNOON AS THE NEXT SYSTEM MOVES IN WITH MVFR AND CHANCES OF RAIN/SNOW. MVFR CIGS TO REACH KMOT-KBIS LATE AFTERNOON...AND AFT 00Z AT KJMS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...JV SHORT TERM...CJS LONG TERM...NH AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
109 AM EST MON FEB 15 2016 .SYNOPSIS... COMPLEX SYSTEM GIVES MESSY CONCOCTION OF WINTRY WEATHER THEN WATER CONCERNS. THE SYSTEM EXITS EARLY TUESDAY...FOLLOWED BY ANOTHER SYSTEM TUESDAY NIGHT. && .NEAR TERM /THROUGH TODAY/... 100 AM UPDATE... UPDATED POPS TO REFLECT DIMINISHING PRECIPITATION OVER THE MIDDLE OHIO VALLEY OVERNIGHT ACCOUNT OF MID LEVEL DRY AIR INTRUSION FROM THE W. THIS MAY NECESSITATE ADJUSTMENTS TO WARNINGS EARLY THIS MORNING. THE MAIN WARM ADVECTION SNOW EVENT WAS STILL OCCURRING OVER THE CENTRAL AND SRN MOUNTAINS...AND CONTINUED MOVING E. PREV DISCN... 900 PM UPDATE...EXTENDED WINTER STORM WARNINGS A ROW OR TWO COUNTIES TO THE NORTH OF THE PREVIOUS WARNING IN THE TRISTATE AREA DUE TO RADAR IMAGERY INDICATING A HEAVY BAND OF SNOW ORIENTED ALONG THE I-64 CORRIDOR. ALSO...THE HI-REZ MESOSCALE MODELS LIKE THE HRRR AND NCAR ENSEMBLES INDICATED QUITE A BIT MORE QPF THAN THE DETERMINISTIC NATIONAL SUITE. ALSO EXTENDED ADVISORIES TO THE NORTHERN TIER OF THE CWA...MAINLY TO HIGHLIGHT THE SNOW TONIGHT AND POTENTIAL FOR FREEZING RAIN TOMORROW. SNOW TO SLEET TO FREEZING RAIN OR JUST RAIN CHANGEOVER STILL LOOKS ON TRACK FOR TOMORROW MORNING IN AND AROUND THE 6 AM TO NOON TIMEFRAME DEPENDING ON LOCATION. SOME LOCATIONS IN THE MOUNTAINS LIKE POCAHONTAS COUNTY COULD SEE SIGNIFICANT ICE ACCUMULATIONS OF OVER A 1/4 TO 1/2 AN INCH...SO BE AWARE OF THAT. PREVIOUS DISCUSSION FOLLOWS... FLAKES SHOULD BE REACHING GROUND ON SCHEDULE IN THE TRI STATE AROUND HTS ON SE TO SOUTHWEST VIRGINIA...NOW THROUGH DARK. MAIN CHANGE WAS JUST TO ADD BOONE AND FAYETTE TO THE SOUTHERN WARNING. ALSO WILL ADD JUST A FEW COUNTIES WITH THE LOWER SNOW CRITERIA TO AN ADVISORY...INCLUDING ATHENS...WOOD...WIRT AND CALHOUN. AS SNOW CHANGES TO RAIN...ADDED SOME POCKETS OF FREEZING RAIN MONDAY IN NORTH CENTRAL WEST VIRGINIA DUE TO THE COLD GROUND. MAY EVEN BE SOME FREEZING AT 33 OR 34 DEGREES. NO REASON FOR AN ADVISORY AT THIS DISTANCE IN TIME. TEMPERATURES SHOULD HOLD STEADY OR SLOWLY RISE OVERNIGHT AND MONDAY. THE INCREASING SOUTHEAST FLOW STILL HAS US CONCERNED ABOUT THE FREEZING RAIN FROM THE BECKLEY/OAK HILL VICINITY ON NORTHEAST TO SNOWSHOE AND THE GREENBRIER VALLEY IN POCAHONTAS COUNTY MONDAY AFTERNOON...THEN CONTINUING IN POCAHONTAS COUNTY MONDAY NIGHT. SNOW AMOUNTS WERE MARGINAL FOR BOONE AND FAYETTE COUNTIES FOR THE WARNING. CONDITIONS IMPROVE 18Z MONDAY TO 00Z IN THE DOWNSLOPE AREAS ESPECIALLY WILLIAMSON...LOGAN...MADISON...CHARLESTON VICINITY. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... MONDAY NIGHT...MOST OF THE FORECAST AREA WILL HAVE TURNED TO ALL RAIN HOWEVER COLD AIR BECOMES WEDGED EAST OF APPALACHIANS AND NEAR THE SURFACE TEMPERATURES WILL LIKELY HANG AROUND TO SLIGHTLY BELOW FREEZING THROUGH THE NIGHT IN THE MOUNTAINS. WARM LAYER ALOFT IS MAKING FORECASTING P-TYPES MONDAY NIGHT A CHALLENGE FOR THE MOUNTAINS. CURRENT THINKING IS STARTING THE NIGHT WITH A WINTRY MIX AND THEN TRANSITIONING TO FREEZING RAIN. POCAHONTAS COUNTY WILL LIKELY SEE THE BRUNT OF THE ICING WITH AMOUNTS OF OVER A QUARTER OF AN INCH POSSIBLE. THE OTHER CONCERN THIS FORECAST PERIOD WILL BE RAINFALL ACROSS THE LOWLANDS MONDAY NIGHT. CURRENT QPF AMOUNTS FROM MONDAY AFTERNOON THROUGH TUESDAY ARE CLOSE TO AN INCH IN SOME AREAS AND MINOR FLOODING ISSUES COULD OCCUR AS RAIN FALLS ONTO FRESH SNOW FROM EARLIER IN THE EVENT AND FROZEN GROUND. HOWEVER...TEMPERATURES LOOK TO REMAIN IN THE UPPER 30S TO POSSIBLE LOW 40S SO NOT EXPECTING A RAPID SNOW MELT AND THE NEW SNOW ON THE GROUND SHOULD BE ABLE TO ABSORB A LOT OF THE WATER. AT THIS TIME WAS NOT CONFIDENT ENOUGH IN ANY HYDRO CONCERNS TO ISSUE A FLOOD WATCH...BUT WILL HIGHLIGHT IN THE HWO FOR NOW. AFTER A DRIER BUT OVERCAST INTERLUDE BETWEEN SYSTEMS TUE...06Z MODEL RUNS ARE FARTHER S WITH ANOTHER UPPER LEVEL S/W TROUGH AND ASSOCIATED LOW PRESSURE SYSTEM PROGGED TO CROSS TUE NT. THIS WOULD BRING COLDER AIR BACK INTO THE AREA FROM THE W THROUGHOUT THE COLUMN OVERNIGHT TUE NT...CHANGING ANY RAIN...FREEZING RAIN OR MIXED PRECIPITATION THAT RETURNS TUE EVENING...BACK TO SNOW...WITH LIGHT ADDITIONAL AMOUNTS POSSIBLE OF GENERALLY 1 TO 3 INCHES. USED MOSTLY NAM FOR TEMPERATURES ALOFT AND USED A VARIETY OF GUIDANCE AS WELL AS PREVIOUS OFFICIAL FORECAST FOR SFC TEMPS. QPF AMOUNTS ARE GENERALLY A MIX BETWEEN RFC AND MODEL GUIDANCE. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... OVERALL...QUIET AND WARMER WEATHER WILL TAKE HOLD IN THE LONG TERM. STILL SOME LIGHT UPSLOPE SNOW SHOWERS LINGERING BEHIND DEPARTING CLIPPER EARLY THURSDAY...BUT DRIER...AND WARMER AIR WILL GRADUALLY TAKE HOLD AS HIGH PRESSURE SURFACE AND ALOFT BUILD INTO THE REGION. TEMPERATURES TOWARDS THE END OF THE WEEK COULD EVEN CLIMB INTO THE 50S TO LOWER 60S ACROSS THE LOWLANDS...AS WAA INCREASES OUT AHEAD OF AN APPROACHING LOW...WHICH WILL SWEEP A COLD FRONT INTO THE REGION OVER THE WEEKEND...WITH LIGHT RAIN SHOWERS...AND COOLER TEMPERATURES TO END THE WEEK. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... WIDESPREAD IFR GIVING WAY TO IMPROVEMENT TO MVFR/VFR MIDDLE OHIO VALLEY WITH THE SNOW TAPERING OFF THERE. THE LULL WILL CONTINUE THROUGH MON MORNING...BEFORE ANOTHER WAVE BRINGS PRECIPITATION...MAINLY RAIN THIS TIME...BUT IFR CIGS RETURNING LATE MON AND MON NT. THERE MAY NOT BE MUCH OF A LULL IN THE MOUNTAINS...BUT PRECIPITATION WILL GO TO A MIX THERE BY EARLY AFTERNOON BKW AND LATE AFTERNOON EKN...WITH A BRIEF PERIOD OF SLEET AND FREEZING RAIN IN THE TRANSITION TO EVENTUALLY RAIN...THIS WILL ALLOW CONDITIONS TO IMPROVE TO MAINLY MVFR IN THE MOUNTAINS ALTHOUGH BKW WILL HANG NEAR 1 KFT CIG WITH LOWER CIGS ON HIGHER RIDGES. SFC FLOW WILL BE S TO SE AND A BIT GUSTY ON THE RIDGES...AND FLOW ALOFT WILL BE MODERATE TO STRONG FROM THE SW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: LOW TO MEDIUM ALTERNATE SCENARIOS: TIMING OF THE TRANSITION FROM SNOW TO RAIN COULD DIFFER AND VISIBILITIES MAY DROP TO IFR OR BELOW MON AFTERNOON AND EVENING WITH ADVECTION FOG. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE MON 02/15/16 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY L L L L L L L L L M M M HTS CONSISTENCY L L L L L M M M M M M M BKW CONSISTENCY L L L L L L L L L L L M EKN CONSISTENCY L L L L L M M M M M M L PKB CONSISTENCY M M L L M M M M M M M M CKB CONSISTENCY M M M M M M M M M M M M AFTER 06Z TUESDAY... PROLONGED IFR CONDITIONS WILL LIKELY PERSIST IN MID OHIO VALLEY AND CENTRAL APPALACHIANS INTO WED. LOW CIGS AND VSBYS IN MOSTLY RAIN AND FOG OVERNIGHT MON NT INTO TUE...THEN MIXED LIGHT RAIN AND SNOW TUE NT INTO WED. && .EQUIPMENT... HAVING ON/OFF PROBLEMS WITH THE CKB ASOS. TEMPERATURE READING TOO HIGH AT TIMES. TROUBLE TICKET CLOSED EARLIER BUT RE-OPENED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR WVZ007-008-016-027. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR WVZ005- 006-013>015. WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ024>026-033>036. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR WVZ009>011-017>020-028>032-039-040. WINTER WEATHER ADVISORY UNTIL 7 AM EST TUESDAY FOR WVZ037-038- 047. WINTER STORM WARNING UNTIL 10 AM EST TUESDAY FOR WVZ046. OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ083>087. WINTER WEATHER ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR OHZ066-067-075-076. KY...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR KYZ101. WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR KYZ102- 103-105. VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ003- 004. && $$ SYNOPSIS...KTB/MPK/SL NEAR TERM...TRM/JW SHORT TERM...MPK LONG TERM...SL AVIATION...TRM EQUIPMENT...TRM
AREA FORECAST DISCUSSION
NWS PORTLAND OR
900 PM PST SUN FEB 14 2016 .SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH WASHINGTON TONIGHT...AND RAIN WILL DECREASE FROM THE SOUTH AS HIGHER PRESSURE BUILDS INTO WESTERN OREGON. WEAK DISTURBANCES MOVING THROUGH WASHINGTON WILL KEEP THE THREAT OF RAIN AT TIMES PORTLAND NORTHWARD THROUGH TUESDAY WITH DRIER WEATHER TO THE SOUTH. A COLD FRONT IS EXPECTED TO MOVE THROUGH WEDNESDAY AFTERNOON AND EVENING... FOLLOWED BY LOWERING SNOW LEVELS IN THE CASCADES THURSDAY. ANOTHER PACIFIC FRONT APPEARS LIKELY TO MOVE THROUGH THE FORECAST AREA THURSDAY NIGHT AND FRIDAY. && .SHORT TERM...RADAR SHOWED MAIN AREA OF RAIN SHIFTING RAPIDLY NORTHWARD THIS EVENING...UP INTO THE CASCADES AND N INTO NORTHERN WA WHICH AGREED WELL WITH HRRR AND WRF MESOSCALE MODELS. SURFACE OBSERVATIONS HOWEVER INDICATED LIGHT PRECIPITATION WAS STILL FALLING IN THE MOUNTAINS AND ALONG THE COAST FURTHER S THROUGH WESTERN OREGON...MAINLY IN AREAS WHERE LOW LEVEL OROGRAPHIC LIFT WAS ACCOMPANIED BY LOW LEVEL MOISTURE. AS THE DEEPER MOISTURE ASSOCIATED WITH THE BAROCLINIC ZONE LIFTS N TONIGHT AND IS EXPECTED TO REMAIN TO THE N MON WILL BACK OFF ON POPS IN GENERAL TONIGHT AND MON...BUT WILL NEED TO HANG ONTO SOME LOW POPS LATER TONIGHT INTO MON MORNING FURTHER S MAINLY IN THE MOUNTAINS AND ALONG THE COAST WHERE A WEAKENING MOIST ONSHORE FLOW CONTINUES. REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...WITH WARMER AIR MOVING IN ALOFT...THE CHANCE FOR INVERSIONS AND VALLEY FOG WILL BE INCREASING FOR THE EUGENE AREA TONIGHT/MON MORNING THEN ACROSS MUCH OF CWA MON NIGHT/EARLY TUE. THIS COULD PUT A MONKEY WRENCH IN THE TEMPERATURE FORECASTS...BUT FOR NOW GUIDANCE SUGGESTS ANY FOG WILL BURN OFF EARLY ENOUGH FOR IT TO HAVE LITTLE IMPACT ON MAX TEMPS. OTHERWISE...WITH 500 MB HEIGHTS AROUND 570 DAM AND 850 MB TEMPS ON THE ORDER OF +4 TO +8 DEG C...EXPECT TEMPS TO REMAIN A FEW DEGREES ABOVE NORMAL THROUGH TUESDAY AND PROBABLY WEDNESDAY AS WELL. NIGHTS WILL BE UNSEASONABLY MILD DUE TO THE HIGH DEWPOINTS ASSOCIATED WITH THIS MOIST AIR MASS. MODELS ARE COMING INTO REASONABLE AGREEMENT THAT A COLD FRONT WILL APPROACH THE PAC NW COAST EARLY WED...SPREADING RAIN ACROSS OUR FORECAST AREA WEDNESDAY AFTERNOON AND EVENING. EXPECT A QUICK DROP IN SNOW LEVELS AFTER THIS SYSTEM MOVES THROUGH...WITH SNOW LEVELS POSSIBLY AS LOW AS THE CASCADE PASSES BY WED NIGHT. 18Z GFS SHOWS 925-850 MB WINDS REACHING 45-55 KT ALONG THE COAST WED AFTERNOON. IF THIS VERIFIES IT COULD BE A BIT WINDY ALONG THE COAST JUST AHEAD OF THE FRONT...THOUGH AM INCLINED TO BELIEVE THE NEUTRAL OR NEGATIVE TILT TO THIS SYSTEM WILL KEEP THE STRONGEST WINDS SOUTH OF OUR FORECAST AREA.WEAGLE .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS. WEDNESDAY NIGHT THROUGH SATURDAY...PROGRESSIVE PATTERN CONTINUES THROUGH LATE NEXT WEEK...WITH BACK-TO-BACK SYSTEMS BRINGING RAIN THROUGH AT LEAST FRIDAY. UPPER-LEVEL TROUGH DROPS DOWN OUT OF THE GULF OF ALASKA MIDWEEK...BRINGING SNOW LEVELS MAYBE FAR ENOUGH DOWN TO BRING SOME SNOW TO HIGHER ELEVATIONS IN THE CASCADE FOOTHILLS THURSDAY. SNOW LEVELS COME UP A BIT ON FRIDAY AHEAD OF THE NEXT FRONT MOVING THROUGH MID-DAY. SNOW LEVELS DROP BACK DOWN BEHIND THIS FRONT FRIDAY NIGHT FOR ANOTHER BRIEF CHANCE FOR SNOW IN HIGHER ELEVATIONS OF THE CASCADE FOOTHILLS EARLY SATURDAY. MODELS ARE SUGGESTING RIDGING BUILDING BACK IN NEXT WEEKEND WHICH WOULD BRING BACK DRY OFFSHORE FLOW. -MCCOY && .AVIATION...STEADIER RAIN TAPERING OFF THIS EVENING AS A WARM FRONT LIFTS WELL NORTH OF THE REGION. EXPECT OCCASIONAL DRIZZLE OVERNIGHT AT THE COAST AND FOR THE NORTHERN INTERIOR TAF SITES. EXPECT IFR OR LOWER CONDITIONS TO REMAIN AT THE COAST THROUGH MON. OVER THE INTERIOR...EXPECT MVFR CIGS TO PERSIST THROUGH MOST OF MON MORNING OVER THE NORTH...POTENTIALLY LOWERING TO IFR AT TIMES. FURTHER SOUTH...CLOUDS MAY SCATTERED OVERNIGHT...ALLOWING PATCHY IFR STRATUS OR FOG TO FORM. CONDITIONS SHOULD IMPROVE TO VFR FOR THE INTERIOR BY AROUND MIDDAY. STRONG WLY 850 MB FLOW WILL MAINTAIN IFR OR WORSE CONDITIONS FOR THE HIGHER TERRAIN THROUGH TONIGHT. KPDX AND APPROACHES...LOW-END MVFR CIGS AROUND 1500 FT EXPECTED TO PERSIST THROUGH MON MORNING. THERE IS A CHANCE THAT CONDITIONS WILL DETERIORATE TO IFR LATE TONIGHT. A GRADUAL IMPROVEMENT TO LOW- END VFR BY MIDDAY MON. PYLE && .MARINE...SOUTHWEST WINDS DROPPED BELOW 20 KT THIS AFTERNOON. HOWEVER...THE FCST MODELS SUGGEST THAT WIND SPEEDS WILL PICK UP THROUGH THE NEXT FEW HOURS. EXPECT WINDS OF 20 TO 25 KT OVERNIGHT THROUGH MON AFTERNOON. A SMALL CRAFT ADVISORY FOR WINDS IS IN EFFECT FOR ALL OF THE WATERS. EXPECT WINDS TO DROP OFF OVER THE CENTRAL OREGON WATERS LATER MON...BUT SMALL CRAFT ADVISORY WINDS MAY END UP CONTINUING OVER THE NORTHERN WATERS INTO EARLY TUE. THE NEXT SIGNIFICANT SYSTEM REACHES THE WATERS LATE WED. GFS AND ECMWF CONTINUE TO EXHIBIT DIFFERENCES. FAVORED THE ECMWF BUT WITH SLIGHTLY STRONGER WIND SPEEDS. POTENTIAL EXISTS FOR LOW-END GALE GUSTS WED NIGHT. ANOTHER STRONG SYSTEM IS MODELED FOR FRI...WHICH COULD BRING MORE SOLID GALES. HAVE INDICATED GUSTS TO 40 KT OVER THE OUTER WATERS. SEAS HAVE NOW DROPPED BELOW 10 FT...SO HAVE DROPPED THE SMALL CRAFT ADVISORY FOR SEAS. SEAS LIKELY TO BE JUST UNDER 10 FT THROUGH MON...BUT THEN EXCEED 10 FT MON EVENING. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT AROUND MID-WEEK. PYLE && .PQR WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST TUESDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM. SMALL CRAFT ADVISORY FOR WINDS FROM MIDNIGHT TONIGHT TO 6 PM PST MONDAY FOR COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL MIDNIGHT PST TONIGHT. SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 8 AM TO NOON PST MONDAY. && $$ INTERACT WITH US VIA SOCIAL MEDIA WWW.FACEBOOK.COM/NWSPORTLAND WWW.TWITTER.COM/NWSPORTLAND THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
326 AM CST MON FEB 15 2016 .DISCUSSION... SKIES ARE CLOUDY ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING WITH TEMPERATURES RANGING FROM THE LOWER 30S TO LOWER 50S. RAIN IS CURRENTLY FALLING OVER PORTIONS OF EAST ARKANSAS...WEST TENNESSEE AND NORTH MISSISSIPPI. A FEW LOCATIONS HAVE TEMPERATURES BELOW FREEZING BUT HAVE NO PRECIPITATION AT THIS TIME SO HAVE ALLOWED WINTER WEATHER ADVISORY TO EXPIRE AT 300 AM. A WEAK COLD FRONT CURRENTLY EXTENDS ACROSS NORTH MISSISSIPPI THROUGH EXTREME SOUTHERN ARKANSAS AND INTO NORTH CENTRAL TEXAS. THIS FRONT WILL DROP SLOWLY SOUTH TODAY. LOW PRESSURE WILL MOVE ALONG THE FRONT TODAY WHICH WILL PRODUCE MORE SHOWERS FOR MUCH OF THE FORECAST AREA. TEMPERATURES WILL BE MAINLY BELOW NORMAL LEVELS TODAY WITH HIGHS FROM THE MID 40S TO MID 50S. AS THE COLD FRONT MOVES AWAY FROM THE FORECAST AREA TONIGHT RAIN WILL BE ENDING DURING THE EVENING HOURS. THE AIR BEHIND THIS COLD FRONT IS NOT PARTICULARLY COLD SO TEMPERATURES TONIGHT WILL BE CLOSE TO NORMAL LEVELS WITH LOWS TUESDAY MORNING IN THE MID 30S TO LOWER 40S. ANOTHER COLD FRONT WILL DROP THROUGH THE CENTRAL PLAINS AND INTO THE FORECAST AREA ON TUESDAY. THIS WILL MEAN ANOTHER CHANCE OF RAIN FOR THE REGION. BEFORE THE FRONT MOVES THROUGH TEMPERATURES WILL WARM UP SOME WITH HIGHS FROM MID 50S TO LOWER 60S. THIS COLD FRONT WILL BE OUT OF THE REGION TUESDAY NIGHT BRINGING AN END TO THE RAIN. TEMPERATURES WILL BE A LITTLE COOLER BEHIND THE FRONT FOR TUESDAY NIGHT AND WEDNESDAY BUT WILL REMAIN ABOVE NORMAL LEVELS. HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER FOR WEDNESDAY AND THURSDAY BRINGING A PERIOD OF DRY WEATHER. TEMPERATURES WILL BE ABOUT THE SAME ON WEDNESDAY AS THEY WILL BE TUESDAY WITH HIGHS MAINLY IN THE 50S. MUCH WARMER AIR WILL MOVE INTO THE REGION FOR THURSDAY WITH HIGHS MAINLY IN THE 60S. MODELS ARE NOT IN AGREEMENT WITH THE TIMING OF THE NEXT COLD FRONT WHICH SHOULD MAKE ITS WAY INTO THE REGION BY SATURDAY NIGHT. HAVE GONE WITH A DRY FORECAST FOR FRIDAY THROUGH SATURDAY WITH A CHANCE OF RAIN STARTING SATURDAY NIGHT. TEMPERATURES WILL REMAIN ABOVE NORMAL DURING THIS PERIOD. ONCE THIS FRONT MOVES INTO THE REGION IT IS EXPECTED TO STALL OUT SO THE THREAT OF RAIN WILL CONTINUE INTO SUNDAY AS WELL. ARS && .AVIATION... 06Z TAFS 00Z NAM AND 02Z HRRR BRING POST FRONTAL IFR TO TO MEM AND MKL DURING THE NIGHT...WHILE ISOLATED TSRA WILL LIKELY LIFT EAST ACROSS NORTH MS NEAR THE SFC FRONT...DURING THE OVERNIGHT. WILL BE CLOSE AS TO WHETHER THIS ACTIVITY GETS TO WITHIN 25 MILES OF MEM...BUT HAVE INCLUDED A VCTS INTO MEM BEGINNING AT 09Z. OTHERWISE...TSRA WILL BE POSSIBLE AT TUP FROM LATE MORNING INTO MIDDLE AFTERNOON. FOLLOWING THE EXIT OF THE SYSTEM LATE MONDAY AFTERNOON...RESIDUAL LOW LEVEL MOISTURE...RECENT RAINFALL AND LIGHT WINDS WILL PRESENT A RISK OF LOW CLOUDS AND GROUND FOG MONDAY EVENING. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...NONE. MO...NONE. MS...NONE. TN...NONE. && $$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1141 PM CST SUN FEB 14 2016 .UPDATE... UPDATED FOR 06Z AVIATION DISCUSSION BELOW. && .PREV DISCUSSION... /ISSUED 915 PM CST SUN FEB 14 2016/ UPDATE... A FEW CHANGES HAVE BEEN MADE TO THE FORECAST THIS EVENING OUTLINED BELOW. AN IMPRESSIVE THERMAL GRADIENT HAS ESTABLISHED ITSELF ROUGHLY ALONG THE I40 CORRIDOR THIS EVENING WITH FREEZING RAIN CONTINUING ACROSS PORTIONS OF NORTHEAST AR/MO BOOTHEEL/NORTHWEST TN. NO CHANGES HAVE BEEN MADE TO THE CURRENT ADVISORY WHICH IS IN EFFECT THROUGH MIDNIGHT. FURTHER SOUTH...VERY STRONG ISENTROPIC ASCENT WILL DEVELOP UP THE SHARPLY SLOPED FRONTAL ZONE AS A STRENGTHENING LOW LEVEL JET PERSISTS THROUGH MONDAY MORNING. BOTH GLOBAL AND HI-RES GUIDANCE SUGGESTS A NARROW BUT HEAVY AXIS OF PRECIP DEVELOPING THROUGH MUCH OF SUNDAY NIGHT...LASTING THROUGH MONDAY MORNING. IN FACT...THE GFS DEPICTS TOTALS BETWEEN 4-5 INCHES. THIS SOLUTION IS CLEARLY AN OUTLIER...BUT RAINFALL TOTALS BETWEEN 2-3 INCHES ARE POSSIBLE SOUTH OF I40. FORECAST SOUNDINGS ALSO SHOW ELEVATED INSTABILITY PERSISTING ABOVE THE SURFACE FRONTAL BOUNDARY WHICH SHOULD BE SUFFICIENT TO GENERATE THUNDER ALONG AND SOUTH OF I40 AFTER MIDNIGHT. TVT PREV DISCUSSION... /ISSUED 551 PM CST SUN FEB 14 2016/ UPDATE... UPDATED FOR 00Z AVIATION DISCUSSION BELOW. PREV DISCUSSION... /ISSUED 343 PM CST SUN FEB 14 2016/ DISCUSSION... AT 3PM... SURFACE ANALYSIS PLACES A 1036 MB HIGH OVER NEW YORK STATE WITH SOUTHERLY SURFACE FLOW OVER MUCH OF THE MIDSOUTH AS A RESULT. A WEAK SURFACE BOUNDARY STRETCHES FROM NEAR HICKORY RIDGE ARKANSAS NORTHEAST TO NEAR PARIS TENNESSEE. WINDS TO THE NORTH OF THIS FEATURE HAVE BECOME NORTHERLY AGAIN AND TEMPERATURES HAVE DROPPED A DEGREE OR SO AT SOME LOCALES AS A RESULT. PRECIPITATION IS ONGOING IN THE VICINITY OF THE FEATURE...MUCH OF WHICH COULD BE FREEZING DRIZZLE AT THE SURFACE WITH TEMPERATURES ACROSS EXTREME NORTH WEST TENNESSEE...THE MISSOURI BOOTHEEL...AND NORTHEAST ARKANSAS BELOW FREEZING. PRECIPITATION IS EXPECTED TO BE FOCUSED ALONG THE SURFACE BOUNDARY THIS EVENING AND TONIGHT AS IT SLOWLY MOVES SOUTHEAST. CONCERN FOR CONTINUED FREEZING RAIN OR FREEZING DRIZZLE HAS PROMPTED THE CONTINUATION OF THE WINTER WEATHER ADVISORY THROUGH MIDNIGHT WHEN TEMPERATURES IN THE ADVISORY AREA ARE EXPECTED TO GRADUALLY CLIMB. WHATEVER PRECIPITATION IS LEFT IN THOSE AREAS AT THAT TIME WOULD CHANGE TO RAIN...ALTHOUGH MODELS INDICATE DRY CONDITIONS BUILDING INTO THESE LOCATIONS BY MIDNIGHT. A DEVELOPING LOW CURRENTLY OVER SOUTHERN OKLAHOMA WILL GRADUALLY MOVE ALONG THE SURFACE BOUNDARY OVERNIGHT AND INTO MONDAY AS A WAVE AMPLIFIES ALOFT...INDUCING RAINFALL OVER MUCH OF THE MIDSOUTH. MODELS MARCH THE DEEPENING LOW OVER NORTH MISSISSIPPI BY MONDAY AFTERNOON WHICH WILL LEAD TO HEAVIER QPF AMOUNTS BY LATE MONDAY FOR MANY LOCATIONS ALONG AND SOUTH OF INTERSTATE 40. 1 TO 3 INCHES OF QPF IS POSSIBLE OVER MANY OF THESE AREAS BY EARLY TUESDAY. ADDITIONALLY...A PORTION OF NORTHEAST MISSISSIPPI WILL BECOME ENVELOPED IN THE WARM SECTOR OF THE SURFACE LOW WHICH WILL ALLOW TEMPERATURES TO WARM TO NEAR 60 IN THOSE LOCATIONS...UPPER 40S AND 50S ELSEWHERE...WHILE ALSO CREATING A CHANCE FOR A FEW THUNDERSTORMS ON MONDAY AFTERNOON WITH VERY LIMITED INSTABILITY AVAILABLE AT BEST. THE LOW MOVES EAST ON MONDAY NIGHT AS GUIDANCE SUGGESTS ANOTHER SURFACE LOW MOVES FROM NORTHWEST TO SOUTHEAST IN THE VICINITY OF THE MIDSOUTH ON TUESDAY. MODELS DIVERGE ON PLACEMENT OF THIS FEATURE...WITH THE GFS AND NAM WELL EAST OF THE AREA...SO ONLY INCLUDED POPS FOR NORTHEAST PORTIONS OF THE FA. TUESDAY HIGHS WILL WARM INTO THE 50S AND 60S. DRIER AND A TAD COOLER ON WEDNESDAY WITH HIGH PRESSURE BUILDING INTO THE REGION UNDER MOSTLY NORTHWEST FLOW ALOFT. A WARMING TREND BEGINS ON THURSDAY AS THE SURFACE HIGH SHIFTS EAST...RETURNING SOUTHERLY SURFACE FLOW. A RIDGE ALSO BUILDS IN ALOFT WHICH WILL LEAD TO THURSDAY AND FRIDAY TEMPERATURES IN THE 60S TO NEAR 70...SOME 10 TO 15 DEGREES WARMER THAN NORMAL FOR MID FEBRUARY. RAIN CHANCES COULD RETURN NEXT WEEKEND WITH A TRAILING COLD FRONT FROM A LOW CENTERED OVER THE GREAT LAKES REGION MOVING THROUGH SATURDAY BEFORE A DEVELOPING LOW MOVES EAST INTO THE REGION NEXT SUNDAY. ZDM && .AVIATION... 06Z TAFS 00Z NAM AND 02Z HRRR BRING POST FRONTAL IFR TO TO MEM AND MKL DURING THE NIGHT...WHILE ISOLATED TSRA WILL LIKELY LIFT EAST ACROSS NORTH MS NEAR THE SFC FRONT...DURING THE OVERNIGHT. WILL BE CLOSE AS TO WHETHER THIS ACTIVITY GETS TO WITHIN 25 MILES OF MEM...BUT HAVE INCLUDED A VCTS INTO MEM BEGINNING AT 09Z. OTHERWISE...TSRA WILL BE POSSIBLE AT TUP FROM LATE MORNING INTO MIDDLE AFTERNOON. FOLLOWING THE EXIT OF THE SYSTEM LATE MONDAY AFTERNOON...RESIDUAL LOW LEVEL MOISTURE...RECENT RAINFALL AND LIGHT WINDS WILL PRESENT A RISK OF LOW CLOUDS AND GROUND FOG MONDAY EVENING. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR CLAY-GREENE- LAWRENCE-RANDOLPH. MO...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR DUNKLIN- PEMISCOT. MS...NONE. TN...WINTER WEATHER ADVISORY UNTIL 3 AM CST MONDAY FOR BENTON TN- HENRY-LAKE-OBION-WEAKLEY. && $$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1116 PM CST SUN FEB 14 2016 .DISCUSSION... INTERESTING EVOLUTION OF WINTER WEATHER EVENT HAS OCCURRED THIS EVENING AS SURFACE FREEZING LINE HAS SAGGED BACK SOUTHWARD TO NEAR THE I-40 CORRIDOR. THIS APPEARS TO HAVE BEEN DUE TO A WEAK WAVE MOVING NORTHEASTWARD ALONG THE INVERTED TROUGH IN PLACE FROM SW TO NE ACROSS THE CWA. 02Z HRRR AND 00Z NAM INSIST FREEZING LINE WILL RETURN BACK NORTHWARD THIS EVENING/OVERNIGHT...AND THIS APPEARS TO BE UNDERWAY AS TEMPERATURES HAVE RISEN INTO THE LOW 30S AT CKV AND INTO SOUTHERN KY. HOWEVER...LIGHT SLEET/FZRA WILL CONTINUE FOR ANOTHER HOUR OR TWO FOR THE I-40 CORRIDOR COUNTIES...AND LIKELY LINGER PAST MIDNIGHT FOR THE KY BORDER COUNTIES WHERE TRAVEL IMPACTS REMAIN SIGNIFICANT. THUS HAVE EXTENDED THE WWA UNTIL 12Z FOR THE NORTHWESTERN COUNTIES AS TRAVEL WILL REMAIN HAZARDOUS THERE THROUGH THE OVERNIGHT HOURS. ALTHOUGH MOST OBS ARE WELL ABOVE FREEZING IN THE CENTRAL PLATEAU COUNTIES...KEPT THE ADVISORY GOING FOR PUTNAM/WHITE/CUMBERLAND/VAN BUREN AS SOME AREAS REMAIN BELOW FREEZING...MAINLY THE HIGHER ELEVATIONS. UPDATED PRODUCTS OUT SHORTLY. && .AVIATION... 06Z TAF DISCUSSION. POOR FLYING CONDITIONS NEXT 24 HOURS DUE TO LOW CEILINGS...VISIBILITIES AND PRECIP. 32 DEGREE ISOTHERM EXTENDS PRETTY MUCH ALONG INTERSTATE 40 WITH SLEET AND FREEZING RAIN ALONG AND NORTH. SHORT RANGE MODELS SEEM TO BE TOO FAST BY AT LEAST 2 HOURS AND POSSIBLY 3 IN TAKING FREEZING LINE TO THE KENTUCKY BORDER. SO THAT MEANS SLEET AND FREEZING RAIN LASTING A LITTLE LONGER OVER NORTHERN MIDDLE TENNESSEE BEFORE CHANGE OVER TAKES PLACE. && .OHX WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR CLAY- CUMBERLAND-FENTRESS-JACKSON-MACON-MONTGOMERY-OVERTON-PICKETT- PUTNAM-ROBERTSON-STEWART-SUMNER-VAN BUREN-WHITE. && $$ SHORT TERM/AVIATION........01/BOYD LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
402 AM CST MON FEB 15 2016 .SHORT TERM (TODAY THROUGH TUESDAY)... MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED TODAY AND TUESDAY. WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH- CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE FRONT THAT IS NOW LOCATED ALONG A DALLAS TO WACO TO OZONA LINE. LOW CLOUDS AND AREAS OF FOG WILL OCCUR NOW THROUGH 8-10AM WITH SOME POCKETS OF DENSE FOG POSSIBLE ALONG WITH DRIZZLE/MIST WHERE THE FOG/LOW CLOUDS ARE THICKER NEAR THE SURFACE. THE WEAK BOUNDARY WILL SWEEP THROUGH THE HILL COUNTRY AND AUSTIN BY 7-9AM AND THROUGH SAN ANTONIO BEFORE 11AM. RAPID CLEARING OF CLOUDS IS EXPECTED BEHIND THE BOUNDARY WITH SUNNY CONDITIONS AND BREEZY NORTH WINDS EXPECTED THIS AFTERNOON. THE COMBINATION OF WINDS GUSTING TO NEAR 20-25 MPH AND THE DRIER AIR MOVING IN WILL PROMOTE ELEVATED FIRE WEATHER CONDITIONS ACROSS THE RIO GRANDE PLAINS AS RELATIVE HUMIDITY VALUES DIP NEAR TO JUST BELOW 20% THIS AFTERNOON. FOR TUESDAY...A SLIGHTLY COOLER MORNING IS EXPECTED GIVEN THE DRIER AIR AND NEAR CALM WINDS BUT READINGS WILL BE NEAR CLIMATE NORMALS. EXPECTED CLEAR SKIES WITH PLENTY OF SUN WITH HIGHS REACHING ABOVE NORMAL INTO THE UPPER 70S AND LOW 80S AREAWIDE. SOME LOCATIONS IN THE RIO GRANDE PLAINS COULD REACH INTO THE MID 80S. && .LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)... WELL ABOVE NORMAL TEMPERATURES OF 10-15F DEGREES ARE EXPECTED MID TO LATE WEEK WITH A SLIGHT COOL DOWN INTO THE WEEKEND. DRY CONDITIONS WILL ALSO REMAIN UNTIL EARLY NEXT WEEK WHERE A MORE SUBSTANTIAL COLD FRONT AND BETTER RAIN CHANCES COULD OCCUR. CONUS PATTERN MID TO LATE WEEK WILL FEATURE SURFACE HIGH PRESSURE OVER THE MID-MS RIVER VALLEY WITH SOUTHEAST LOW-LVL FLOW THAT VEERS TO THE SOUTHWEST/WEST IN THE MID-LVLS OVER TEXAS. THIS TYPE OF PATTERN ALONG WITH A BUILDING H5 RIDGE AND H925 TEMPS 23-16C FROM WEST TO EAST WILL SUPPORT UPPER 70S TO MID 80S. WHILE IT WILL BE WARM...RECORD TEMPERATURES DO NOT LOOK TO BE IN JEOPARDY AS THOSE VALUES ARE ALREADY WELL INTO THE 90S. MORNING CLOUDS LOOK TO RETURN THURSDAY AND FRIDAY BUT QUICK MIX OUTS BY MID MORNING HOURS TO PARTLY AND MOSTLY SUNNY SKIES WILL OCCUR. SLIGHTLY COOLER H925 AIR WILL PIVOT IN ACROSS THE REGION THIS WEEKEND AS THE H5 RIDGE BREAKS DOWN AND SOME WEAK IMPULSES MIGRATE OVER THE REGION THAT WILL CREATE SOME MORE MID-LVL CLOUDS. GLOBAL LONG RANGE MODELS CONTINUE TO HINT AT IN DECENT ACCORD A MORE ACTIVE SOUTHERN JET STREAK BRANCH OVER SOUTH TEXAS NEXT SUNDAY- TUESDAY. THIS ACTIVE BRANCH WILL HELP BUCKLE THE FLOW WITH ENHANCED TROUGHING THAT, IN CONJUNCTION WITH THE POLAR JET, WILL AID A STRONGER CANADIAN ORIGINATED FRONT TO APPROACH THE AREA AROUND MONDAY. THIS STRONGER FRONT AND BETTER DYNAMIC SUPPORT SHOULD ALLOW FOR BETTER RAIN/TSTORM CHANCES IN THIS TIME FRAME. WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM AND ITS LIKELY MORE WIDESPREAD RAIN SIGNAL FOR THE REGION. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 75 47 81 50 82 / 10 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 75 43 80 45 81 / 10 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 77 44 81 47 81 / - 0 0 0 0 BURNET MUNI AIRPORT 73 44 79 46 80 / - 0 0 0 0 DEL RIO INTL AIRPORT 80 46 85 51 87 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 73 44 80 46 80 / 10 0 0 0 0 HONDO MUNI AIRPORT 80 42 82 46 83 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 76 44 79 46 79 / - 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 76 46 79 47 80 / 10 0 0 0 0 SAN ANTONIO INTL AIRPORT 77 46 80 49 82 / 0 0 0 0 0 STINSON MUNI AIRPORT 79 46 82 48 82 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...17 SYNOPTIC/GRIDS...ALLEN
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NWS MELBOURNE FL
1017 AM EST MON FEB 15 2016 .DISCUSSION... ...SLIGHT CHANCE FOR STRONG STORMS THIS EVENING/OVERNIGHT... UPDATE...THE MORNING SOUNDING FROM XMR SHOWS THAT ADDITIONAL RECOVERY WILL BE REQUIRED FOR BETTER CHCS OF RAIN. AVAILABLE PWAT FROM SONDE RELEASE TIME WAS STILL ONLY AROUND 0.77 INCHES ALONG WITH A RESIDUAL CAP JUST ABV H85. BRISK WINDS OF 20 TO 30 KT FROM NEAR SFC THROUGH 5K FT SHOULD PROVIDE SUITABLE MOISTURE WITH PARTIAL SFC HEATING HELPING TO STEEPEN UP THE ENVIRONMENTAL LAPSE RATE UNDERNEATH A COOL H5 TEMP OF -15C. LTST HRRR GUID SHOWS LAND BASED PCPN DEVELOPMENT AFT 1 PM MAINLY SOUTH OF THE BEACHLINE EXPRESSWAY TO LAKE OKEE. THE LATE DAY AND OVERNIGHT PERIOD WL REMAIN FAVORED TIME FOR RAIN CVG ALONG WITH THUNDER CHCS. WL KEEP CURRENT FORECAST IN PLACE. TODAY-TONIGHT...(PREV DISC) SHORTWAVE TROUGH DIGGING ACROSS THE SOUTHERN STATES WILL GENERATE A SURFACE LOW VICINITY OF THE LOWER MISSISSIPPI VALLEY EARLY TODAY...WHICH WILL GRADUALLY DEEPEN WHILE LIFTING INTO THE SOUTHERN APPALACHIANS TONIGHT. THIS SYSTEM WILL BE MOVING RATHER QUICKLY SO MOISTURE RETURN AND INSTABILITY WILL BE LIMITED. STILL...WITH GOOD LARGE SCALE ASCENT...EXPECT HIGH RAIN CHANCES PRIMARILY DURING THE OVERNIGHT PERIOD. THE GFS AND HRRR HAVE BEEN SHOWING SOME CONVECTION DEVELOPING LATE AFTERNOON/EARLY EVENING FROM BOUNDARY INTERACTIONS. HAVE GONE WITH 30 PERCENT POPS DURING THE TODAY PERIOD FOR THIS POSSIBILITY... THEN INCLUDED A SLIGHT CHANCE FOR THUNDERSTORMS THROUGH LATE EVENING AS DEEPENING TROUGH GETS NEARER. DURING THE OVERNIGHT PERIOD...MOS POPS INCREASE TO 60-90 PERCENT. DID NOT GO QUITE THAT HIGH AND HAVE SETTLED ON LIKELY POPS (60-70 PERCENT) WITH A CONTINUED SLIGHT CHANCE FOR STORMS...EXCEPT 50 PERCENT POPS IN THE SOUTH. THE MAIN CONCERN WHEN THUNDER IS IN THE FORECAST THIS TIME OF THE YEAR WILL BE THE THREAT FOR STRONG OR SEVERE STORMS. WITH SURFACE DEW POINTS RECOVERING ONLY INTO THE LOWER 60S AND THE PRIMARY SUPPORT FOR DEEP CONVECTION OCCURRING OVERNIGHT...INSTABILITY WILL BE LIMITED. ADDITIONALLY...LOW LEVEL WIND FIELDS ONLY INCREASE TO ABOUT 30-35 KNOTS. BUT IT WILL BE QUITE COLD ALOFT WITH 500 MB TEMPS AROUND MINUS 15 CELSIUS. WILL HAVE TO WATCH FOR PRE FRONTAL CONVECTION OVER THE GULF SPREADING INLAND AND HOLDING TOGETHER SOMEWHAT AS SURFACE WINDS STAY BACKED ENOUGH TO SUSTAIN LOW LEVEL CONVERGENCE. THE GFS SHOWS 0-1KM HELICITY VALUES 100-200 M2S2 OVERNIGHT SO DO NOT WANT TO RULE OUT A SMALL RISK FOR STORM ORGANIZATION AND SEVERE WEATHER. THE STORM PREDICTION CENTER DOES HAVE A MARGINAL RISK FOR ALL OF EAST CENTRAL FLORIDA EXCEPT THE TREASURE COAST. && .AVIATION...A MOISTENING SOUTHEAST WIND FLOW WILL PRODUCE CONSIDERABLE STRATOCUMULUS TODAY WITH CEILINGS MAINLY ABOVE 3500 FEET. THERE WILL BE A CHANCE FOR SHOWERS ESPECIALLY LATE IN THE DAY WITH LOCAL MVFR. AS A STRONG TROUGH ALOFT APPROACHES TONIGHT...SHOWERS WILL INCREASE IN COVERAGE AND EXPECT A SLIGHT CHANCE FOR STORMS SO MVFR CONDITIONS WILL BECOME MORE LIKELY AND LOCAL IFR WILL BE POSSIBLE. && .MARINE... TODAY-TONIGHT...POOR TO HAZARDOUS CONDITIONS FOR SMALL CRAFT OPERATION INDICATED. SOUTHEAST WINDS OVER THE WATERS 20 KNOTS WITH 20 TO 25 KTS WELL OFFSHORE AND GUSTY. WINDS WILL VEER MORE TO THE SOUTH TONIGHT WHILE STAYING AROUND 20 KNOTS. NO CHANGE TO THE PREVIOUS HEADLINES. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...NONE. AM...SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR SEBASTIAN INLET TO JUPITER INLET 0-20 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 0-20 NM. SMALL CRAFT ADVISORY UNTIL 10 AM EST TUESDAY FOR FLAGLER BEACH TO VOLUSIA-BREVARD COUNTY LINE 20-60 NM-SEBASTIAN INLET TO JUPITER INLET 20-60 NM-VOLUSIA-BREVARD COUNTY LINE TO SEBASTIAN INLET 20-60 NM. && $$ JP/DKW
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
622 AM EST MON FEB 15 2016 .SYNOPSIS... A WARM FRONT WILL EXTEND THROUGH SOUTHERN GEORGIA AND ALONG THE SOUTH CAROLINA COAST TODAY. ASSOCIATED LOW PRESSURE MOVING INTO THE LOWER MISSISSIPPI RIVER VALLEY TODAY WILL BE NEAR THE FORECAST AREA TONIGHT. DRYING WILL OCCUR TUESDAY AS THE LOW LIFTS NORTHWARD AND FARTHER AWAY FROM THE AREA. && .NEAR TERM /THROUGH TONIGHT/... TODAY...COLD HIGH PRESSURE WILL BE WEDGED INTO THE FORECAST AREA WITH A WARM FRONT NEAR THE COAST AND IN SOUTHERN GEORGIA. THE FRONT WILL LIFT NORTHWARD SLOWLY. THE NAM SURFACE-BASED LI PATTERN MAINTAINS THE WEDGE PATTERN HERE THROUGH TODAY. STRONG ISENTROPIC LIFT SUPPORTS PRECIPITATION BUT IT SHOULD REMAIN LIMITED BECAUSE OF SHALLOW MOISTURE AND LITTLE UPPER-LEVEL LIFT. THE NAM...GFS...ECMWF...AND ALL SREF MEMBERS INDICATE LITTLE PRECIPITATION...0.01 OF AN INCH THIS MORNING...AND 0.01 TO 0.1 OF AN INCH THIS AFTERNOON. THE HRRR HAS A FEW PATCHES OF LIGHT PRECIPITATIONS THIS MORNING WITH A LITTLE MORE COVERAGE THIS AFTERNOON. SURFACE WET BULB TEMPERATURES AND MODEL FORECAST SOUNDINGS SUPPORT A PREDOMINATE PRECIPITATION TYPE OF FREEZING RAIN OR FREEZING DRIZZLE BECOMING ALL LIQUID FROM SOUTH TO NORTH. THE TIMING SUPPORTS MORE OF A THREAT IN THE NORTH AND WE HAVE POSTED A FREEZING RAIN ADVISORY IN THE NORTH SECTION. THE THREAT OF FREEZING RAIN WILL LIKELY CONTINUE IN THE EXTREME NORTH PART UNTIL ABOUT 100 PM BASED ON THE SREF MEAN TEMPERATURE. IT IS POSSIBLE THE COLDER AIR WILL REMAIN IN PLACE LONGER AS INDICATED BY THE IN-HOUSE WEDGE SCHEME. HOWEVER...IT IS BASED ON THE NAM WHICH AS HAD A COLD BIAS LATELY. GIVEN THE VERY LOW QPF WE EXPECT JUST TRACE ICE ACCUMULATIONS BUT IT TAKES LITTLE ICE TO CAUSE ISSUES. THE THREAT SHOULD BE MAINLY ON ELEVATED SURFACES SUCH AS BRIDGES AND OVERPASSES. TONIGHT...TEMPERATURES SHOULD BE ABOVE FREEZING THROUGHOUT THE AREA AS WARMING OCCURS AHEAD OF APPROACHING LOW PRESSURE. THE NOCTURNAL LOW WILL OCCUR AT SUNSET. CONVERGENCE ASSOCIATED WITH THE LOW...A STRONG H85 JET AND H5 SHORTWAVE TROUGH WILL RESULT IN SHOWERS TONIGHT. THE GUIDANCE WAS CONSISTENT WITH CATEGORICAL POPS. THE NAM...GFS...ECMWF...AND SREF MEAN SUPPORT RAINFALL OF 0.5 TO 1 INCH. THE MODELS DEPICT A NEGATIVE TILT UPPER TROUGH. STRONG UPPER DIVERGENCE AND THE LOW-LEVEL JET MAY RESULT IN ENOUGH INSTABILITY FOR A FEW ELEVATED THUNDERSTORMS. THE NAM INDICATES CROSS TOTALS IN THE MID 20S. DESPITE THE STRONG SHEAR THE THREAT OF SEVERE THUNDERSTORMS SHOULD REMAIN LOW BECAUSE OF A LACK OF SURFACE-BASED INSTABILITY AS INDICATED BY THE NAM LI FORECAST. IT WILL LIKELY BECOME BREEZY TONIGHT WITH INCREASED MIXING NEAR THE COLD FRONT. WE WILL LIKELY NEED A LAKE WIND ADVISORY. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... DRYING SHOULD OCCUR TUESDAY BEHIND THE COLD FRONT AND MAIN MID- LEVEL SHORTWAVE TROUGH. MIXING AND THE PRESSURE GRADIENT ASSOCIATED WITH LOW PRESSURE LIFTING NORTH OF THE AREA SHOULD RESULT IN BREEZY CONDITIONS. A LAKE WIND ADVISORY WILL LIKELY BE NEEDED. THE MODELS CONTINUE TO SHOW MUCH OF THE MOISTURE AND LIFT ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH REMAINING NORTH OF THE FORECAST AREA TUESDAY NIGHT. A PRESSURE RIDGE WEST OF THE AREA SHOULD MAINTAIN DRY CONDITIONS WEDNESDAY. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST TUESDAY THROUGH WEDNESDAY. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... THE GFS AND ECMWF DISPLAY DRY RIDGING DOMINATING THROUGH THE MEDIUM-RANGE PERIOD EXCEPT MOISTURE DOES APPEAR TO INCREASE SATURDAY OR SUNDAY ASSOCIATED A DEVELOPING WARM FRONT. THE GFS...ECMWF... AND EKD MOS HAVE POPS LESS THAN 10 PERCENT THROUGH FRIDAY...AND 5 TO 20 PERCENT SATURDAY AND SUNDAY. THE MOS HAS NEAR OR ABOVE NORMAL TEMPERATURES DURING THE PERIOD. && .AVIATION /11Z MONDAY THROUGH FRIDAY/... HIGH CONFIDENCE FOR MVFR OR LOWER CONDITIONS THROUGH THE END OF THE TAF PERIOD. MVFR CIGS ACROSS THE TAF SITES EARLY THIS MORNING WITH EASTERLY WINDS 5 TO 10 KNOTS. GFS LAMP INDICATING MOSTLY MVFR CONDITIONS TODAY LOWERING TO IFR BY THIS EVENING. GIVEN LATEST NAM MODEL GUIDANCE AND CAE VWP...WILL CONTINUE MENTION LLWS AT ALL TAF SITES UNTIL AROUND 14Z WITH 30 KTS AOB 2000 FT POSSIBLE. NO FOG EXPECTED TO DEVELOP TONIGHT DUE TO WIND AND CLOUDS. MOISTURE AND ISENTROPIC LIFT WILL CONTINUE TO INCREASE ACROSS THE AREA EARLY THIS MORNING AS WEDGE CONDITIONS DEVELOP. AT THIS TIME...THINK THE THREAT OF FREEZING RAIN AT ANY OF THE TAF SITES IS LOW. SOME LIGHT RAIN IN THE VCNTY OF OGB EARLY THIS MORNING...OTHERWISE HAVE LEFT OUT MENTION OF PRECIP DUE TO LOW CONFIDENCE IN TIMING. RAIN WILL INCREASE ACROSS THE AREA THIS AFTERNOON SO HAVE MENTIONED IN THE TAFS. SURFACE WINDS WILL BE MAINLY FROM THE NORTHEAST AND EAST GENERALLY LESS THAN 10 KNOTS FOR MUCH OF TODAY...BUT WILL SHIFT TO SOUTH AND INCREASE TO AROUND 10-15 KNOTS WITH GUSTS OVER 20 KNOTS TONIGHT. EXTENDED AVIATION OUTLOOK...WIDESPREAD CIG/VSBY RESTRICTIONS MONDAY NIGHT INTO TUESDAY MORNING AS A SOUTHERN STREAM LOW PRESSURE SYSTEM CROSSES THE REGION. STRONG GUSTY WINDS ALSO EXPECTED MONDAY NIGHT INTO TUESDAY. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...NONE. SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ015-016. && $$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
512 AM CST MON FEB 15 2016 .SHORT TERM...(Today) ISSUED AT 314 AM CST MON FEB 15 2016 08z/2am radar imagery continues to indicate patchy freezing drizzle across central Illinois: however, the areal coverage and intensity has decreased markedly from earlier in the evening. As light southerly winds flow over the cold/snow-covered ground, expect fog and perhaps some drizzle to persist through the morning. Current visibilities are mostly in the 2-5 mile range, but HRRR suggests the potential for even lower visbys as WAA continues and low overcast lifts. Have seen a few reports of 1/4 mile visbys upstream across central Missouri where clouds have temporarily cleared and expect the fog to thicken/spread northeastward into central Illinois over the next few hours. Will need to carefully monitor trends, as a Dense Fog Advisory could be needed if HRRR verifies. For now, will just mention areas of fog in the forecast through midday. A weak short-wave trough evident on latest water vapor imagery over eastern Nebraska will pass to the W/SW of the area today. A small area of light snow associated with this feature over southwest Iowa will spread across northern Missouri and may approach the far SW CWA toward midday: however, all high-res models show the precip dissipating before arriving. Have therefore gone with a dry forecast. Despite continued southerly flow, fog and extensive cloud cover will keep afternoon high temperatures in the middle to upper 30s. .LONG TERM...(Tonight through Sunday) ISSUED AT 314 AM CST MON FEB 15 2016 The next fast-moving storm system embedded within the prevailing northwesterly flow aloft will arrive late tonight into Tuesday, bringing another period of wintry precip to central Illinois. 00z Feb 15 models have all trended south with the track of this system, with the NAM being the furthest north and the GEM the furthest south. Have rejected these two solutions in favor of the middle of the road GFS, which takes the 500mb vort max from northern Missouri 12z Tue to far southern Illinois by 18z Tue. Given this particular track, the heaviest precip will be focused across the central/southern CWA. Have therefore reduced PoPs into the chance category along/north of I-74...while maintaining likely further south across the remainder of the area. Another consequence of a further south track is a slightly colder thermal profile. GFS forecast soundings are generally cold enough for snow initially as the max temp in the elevated warm layer only reaches about 1C. As a result, am expecting snow Tuesday morning, gradually transitioning to a rain/snow mix by afternoon as surface temps rise into the middle to upper 30s. Due to the southward track shift, relatively light precip, and marginal temps...snow accumulations are expected to remain minor. Will see a band of around 1 inch along/southwest of a Canton...to Decatur...to Marshall line...with less than one half inch north of I-74. Another weak short-wave will pass through the region on Wednesday: however, this feature will be moisture-starved and will produce little more than some cloud cover. Once this wave exits, upper heights will begin to rise in earnest in response to a major system coming onshore along the Pacific Coast. Downstream ridging across the central and eastern CONUS will allow a pronounced warming trend to occur by the end of the week. Models have been consistently advertising temps reaching the upper 40s and lower 50s by Thursday, then climbing into the upper 50s and lower 60s on Friday. A weak cold front is still progged to pass through Illinois on Friday, but with only limited moisture to work with, will only mention slight chance for showers with FROPA. After that, temps cool a bit over the weekend, but remain above normal in the 50s for both Saturday and Sunday. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 510 AM CST MON FEB 15 2016 IFR to VLIFR conditions in low clouds and vsbys expected through at least 16z before conditions slowly improve into the afternoon hours. Widespread IFR and LIFR conditions prevailed early this morning due to high moisuture levels in the low levels of the atmosphere. Weak high pressure will push across the area today with forecast soundings indicating a low level inversion in place effectively trapping the moisture through early this afternoon. Will start to take the cigs up above 1000 feet after 16-18z but confidence on that occurring is low at this particular time. Latest short term guidance suggests the lowest vsbys will be along and especially south of I-72 which should include SPI and DEC. However, experience has shown that with these light southerly flow regimes, coupled with a fresh snow cover, BMI has a tendency to stay rather low with the cigs and vsbys and is slow to recover. Will trend in that direction thru at least the morning hours. IFR with some low MVFR cigs expected this evening and overnight with the next weather system moving in after 08z, and affecting mainly the SPI TAF. At this point, will include a VCSH with a threat for some light snow developing before dawn. Surface winds will not be much of a factor through tonight with a light southerly to southwesterly flow today with speeds of less than 10 kts, becoming light south to southeast late tonight. && .ILX Watches/Warnings/Advisories... NONE. && $$ SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
541 AM CST MON FEB 15 2016 .UPDATE... Issued at 542 AM CST MON FEB 15 2016 The AVIATION section has been updated for the 12Z TAF issuance. && .SHORT TERM...(Today through Wednesday) Issued at 255 AM CST MON FEB 15 2016 Scattered light showers continue to stream northeast just clipping southeastern Todd county Kentucky, but based on the KCKV and KBWG METARs this area should be just above freezing. Will therefore let the Winter Weather Advisory expire as scheduled at 3 AM. Elsewhere across the forecast area, most observation sites have visibilities between 1 and 3 miles with light fog, and a few patches of very light freezing drizzle. Weak, drizzly echoes on radar at Midnight have mostly dried up, so doubt there will be much, if any, additional icing this morning. However, will re- issue an SPS mainly to highlight slick driving conditions through the morning commute. The 00Z WRF and most recent HRRR runs keep the shower activity along the TN border through the morning, and then lift it back up over more of west Kentucky this afternoon before pushing east of the area early this evening. Given this timing, temperatures should be above freezing, so there should be no wintry concerns after the sun gets sufficiently high in the sky this morning. The 00Z models bring a compact, intense upper low into the base of the upper trough over the region on Tuesday. The 00Z consensus keeps any QPF northwest of the area through daybreak, but we will have to watch for the potential for either freezing rain or snow with the onset of precipitation in the morning. Model soundings across the northeast show a warm layer only near the surface, so it is conceivable that we will have to monitor for snow through the day as this system passes. Temperatures should be above freezing, so accumulations will be hard to come by even if the snow reaches the ground. This system should exit to the east at or shortly after 00Z Wednesday. Yet another upper-level disturbance will dive southeast into our region for Wednesday, as we continue to be heavily influenced by cyclonic flow aloft. The models are not generating any precipitation with this activity, but it should keep most of the area rather cloudy. .LONG TERM...(Wednesday Night through Sunday) Issued at 255 AM CST MON FEB 15 2016 By Wednesday into Thursday, we will finally be seeing a shift in the upper level pattern, as an upper level ridge builds overhead. As this occurs, we will see quiet weather along with a decent warmup, that has been advertised for quite a while now. Warm air advection will begin in earnest Wednesday night and the entire area will see 850mb temps back above zero by late Thursday morning or afternoon. We should see highs on Thursday well into the 50s per the latest guidance, 2m temps and soundings. We should see 60s by Friday with our far western counties in SEMO maybe touching or getting close to 70 degrees. In fact, even warmer weather will only be a state away, as newest guidance indicating highs around 80 in northeast Oklahoma. Hard to imagine when you`re currently only sitting at 31 degrees. Meanwhile, in the northern Plains, an upper level shortwave will be moving eastward into the Great Lakes Thursday night into Friday. As this occurs, a weak front at the surface will be moving into our area. Moisture still appears to be rather scant but the GFS still tries to eek out some QPF. Whatever does fall, if anything, will be light. But since POPS have already been taken out, will continue with that idea and leave it dry, but will have to keep watching, as the GFS ensembles continue to indicate a few hundredths of QPF with the FROPA. The front dives south but only makes into the Gulf Coast State before stalling out. Models indicate that the front will lift back north toward the area as early as Saturday night. However, Saturday should be a dry day with temperatures remaining in the 60s. Another weak frontal boundary will develop to our west and will move through on Sunday, which means we will continue with the chance for rain. The front should be exiting the area sometime on Sunday night. Could even see some isolated thunderstorms on Saturday night into Sunday as some of the parameters are hinting at it. && .AVIATION... Issued at 542 AM CST MON FEB 15 2016 The main concern for the TAFs this morning is how long to hold onto the LIFR ceilings that currently cover all sites? Freezing fog has also reduced visibilities to IFR or lower levels, and this should improve in the next 2 to 3 hours. At KPAH and KCGI figure that ceilings will lift late this morning and eventually scatter out early this afternoon. The other sites may see IFR ceilings linger through the entire forecast period. Winds will be light through the period. A thick layer of clouds based at 10-15kft should overspread the area this afternoon, and this may help get rid of the low clouds. && .PAH Watches/Warnings/Advisories... IL...NONE. MO...NONE. IN...NONE. KY...NONE. && $$ UPDATE...DRS SHORT TERM...DRS LONG TERM...CW AVIATION...DRS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
728 AM CST MON FEB 15 2016 ...SOUNDING DISCUSSION... THE MORNING SURFACE TEMPERATURE INVERSION UP TO 1500 FEET IS THE ONLY SUBSTANTIAL STABLE LAYER ON THIS MORNING`S SOUNDING. WITH GOOD BOUNDARY LAYER MIXING...THIS LAYER WILL EVENTUALLY BE REMOVED AND SHOULD ALLOW FOR MORE SURFACE BASED STORMS. INSTABILITY AS MEASURED BY MLCAPE IS AROUND 600 J/KG WITH MUCAPE AROUND 1050 J/KG AND LAPSE RATES ARE MODEST AROUND 6.5 TO 7.0 C/KM ABOVE THE INVERSION. LOW LEVEL WIND SHEAR IS ALREADY GOOD WITH BOTH DIRECTIONAL AND SPEED SHEAR PRESENT WITH THE 1KM WINDS FROM THE SOUTH AT 35 KNOTS AND 6KM WINDS FROM THE WEST AT 45 KNOTS. SRH 0-1KM IS OVER 300 M2/S2 AND 0-3KM IS AROUND 380 M2/S2. THE LAST TWO STATEMENTS ARE SUPPORTIVE OF ORGANIZED STORMS AND ROTATING UPDRAFTS. A HAIL THREAT ALSO EXISTS WITH THE FREEZING LEVEL AROUND 9250 FEET AND THE WET BULB ZERO HEIGHT AROUND 8200 FEET. THE POTENTIAL FOR STRONG DOWNBURST WINDS IS NOT AS HIGH AT THIS TIME WITH A DOWNDRAFT CAPE AROUND 700 J/KG. OVERALL MEAN STORM MOTION IS FROM 235 /SOUTHWEST/ AT 36 KNOTS. A PEAK WIND SPEED OF 130 KNOTS AT 40000 FEET WAS OBSERVED AS WE ARE CURRENTLY ON THE NORTHERN SIDE OF A JET STREAK OVER THE NORTHERN GULF OF MEXICO. ANOTHER OPPORTUNITY TO EVALUATE THE PRE-STORM ENVIRONMENT WILL OCCUR AS SPC HAS REQUESTED A SPECIAL RELEASE AROUND 18Z. 12Z BALLOON INFO: A SUCCESSFUL FLIGHT REACHING 20 MILES ABOVE THE GROUND AFTER 103 MINUTES OF ASCENT. THE BALLOON TRAVELED 67 MILES DOWNRANGE FROM THE OFFICE. ANSORGE && .PREV DISCUSSION... /ISSUED 345 AM CST MON FEB 15 2016/ SHORT TERM... THE NEXT 18 HOURS WILL SEE THE MOST ACTIVE WEATHER EXPECTED FOR THE REMAINDER OF THE ENTIRE WEEK. A STRONG UPPER LEVEL TROUGH IS CURRENTLY DIGGING INTO THE SOUTHERN PLAINS AND TEXAS. THIS TROUGH WILL SLIDE THROUGH THE LOWER MISSISSIPPI VALLEY TODAY AND SHOULD BE WELL EAST OF THE AREA BY LATE THIS EVENING AND TONIGHT. A INCREASINGLY WARM AND BUOYANT AIRMASS HAS ADVECTED INTO THE AREA TONIGHT...WITH TEMPERATURES ACTUALLY WARMING IN MANY SPOTS. THIS WARM AND BUOYANT AIRMASS WILL INTERACT WITH THE RAPIDLY INCREASING OMEGA AND RESULTANT LIFT OVERSPREADING THE REGION TO PRODUCE SHOWERS AND THUNDERSTORMS FOR MUCH OF THE DAY. AN INITIAL BAND OF CONVECTION THAT IS CURRENTLY FORMING OVER THE NORTHWEST PARTS OF THE CWA IS ASSOCIATED WITH A HIGHLY DIFLUENT FLOW REGIME ALOFT AND A FAVORABLE JET DYNAMICS ASSOCIATED WITH A 100+ KNOT JET STREAK CURRENTLY SLIDING ACROSS THE GULF SOUTH. THIS BAND OF CONVECTION WILL CONTINUE TO MOVE ACROSS THE NORTHERN HALF OF THE FORECAST AREA THROUGH THE EARLY MORNING HOURS. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CAN BE EXPECTED. A FEW OF THE STORMS COULD BE STRONG...BUT CONDITIONS DO NOT QUITE LOOK PRIMED FOR SEVERE CONVECTION THROUGH AT LEAST MID-MORNING AS CAPE WILL BE SOMEWHAT LIMITED. HEADING INTO THE LATE MORNING AND AFTERNOON HOURS...ANOTHER BAND OF CONVECTION SHOULD PUSH THROUGH THE FORECAST AREA. THIS BAND OF CONVECTION SHOULD FORM ALONG AND JUST AHEAD OF A DRY LINE WHICH IS CURRENTLY FORMING OVER CENTRAL TEXAS. THE DRY LINE SHOULD QUICKLY RACE TO THE EAST AT AROUND THE SAME SPEED AS THE PARENT UPPER LEVEL TROUGH AXIS...AND SHOULD BE MOVING INTO THE ATCHAFALAYA BASIN SOMETIME AROUND NOON BASED ON THE LATEST HRRR GUIDANCE. IT LOOKS LIKE THE STRONGEST FORCING AND GREATEST POTENTIAL FOR CONVECTIVE DEVELOPMENT WILL GENERALLY BE ALONG AND NORTH OF THE I-10 CORRIDOR...AND HAVE THE HIGHEST POPS IN THIS AREA. DYNAMIC FORCING SHOULD BE SLIGHTLY WEAKER SOUTH OF I-10...AND ONLY HAVE CHANCE TO LIKELY POPS FOR THESE AREAS. THE RAIN THREAT SHOULD QUICKLY DIMINISH BY THIS EVENING AS THE DRY LINE PUSHES INTO ALABAMA AND FLORIDA AND STRONG DRY AIR ADVECTION AND SUBSIDENCE OVERTAKES THE AREA. THE SEVERE THREAT SHOULD ALSO BE GREATEST NORTH OF THE I-10 CORRIDOR...WHERE SPEED SHEAR...DIRECTIONAL SHEAR...AND MLCAPE VALUES ARE MAXIMIZED. LAPSE RATES WILL BE QUITE STEEP...AND A LOW WET BULB ZERO HEIGHT OF ONLY 8200 FEET WILL BE FAVORABLE FOR SOME HAIL FORMATION IN THE STRONGEST STORMS. HELICITY VALUES OF 250 M2/S2 OR HIGHER CAN BE EXPECTED THIS AFTERNOON...SO ANY SUSTAINED CONVECTION SHOULD BEGIN TO ROTATE AND TAKE ON SUPERCELL CHARACTERISTICS. THUS...A RISK OF A FEW TORNADOES FORMING WILL ALSO BE PRESENT THIS AFTERNOON AND EVENING. THE ENTIRE AREA SHOULD MOSTLY CLEAR SKIES AND DRY WEATHER IN PLACE BY TOMORROW MORNING...AS DEEP LAYER NORTHWEST FLOW ALOFT AND A STRONG SURFACE RIDGE OVERTAKE THE GULF SOUTH. THIS SAME GENERAL PATTERN SHOULD PERSIST INTO WEDNESDAY AS WELL. NOT MUCH IN THE WAY OF COLD AIR ADVECTION IS EXPECTED WITH THIS RIDGE OF HIGH PRESSURE...SO TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY ABOVE AVERAGE IN THE 60S AND LOWER 70S BOTH DAYS. OVERNIGHT LOWS WILL COOL INTO THE 40S AND LOWER 50S BOTH NIGHTS. LONG TERM... HEADING INTO THE LATTER HALF OF THE WEEK...DEEP LAYER RIDGING WILL DEVELOP OVER THE AREA...AS A STRONG UPPER LEVEL HIGH MOVES IN FROM THE SOUTHERN PLAINS AND BECOMES CENTERED OVER THE GULF SOUTH. SINKING AIR THROUGHOUT THE ATMOSPHERIC COLUMN...ALONG WITH A RETURN TO ONSHORE FLOW WILL ALLOW TEMPERATURES TO WARM EVEN FURTHER. HIGHS WILL EASILY CLIMB INTO THE MIDDLE TO UPPER 70S THURSDAY THROUGH SUNDAY...AND OVERNIGHT LOWS SHOULD ONLY DIP INTO THE 50S FOR MOST LOCATIONS. CONDITIONS MAY BE FAVORABLE FOR ADVECTION FOG TO DEVELOP AS DEWPOINTS RISE INTO THE UPPER 50S AND LOWER 60S. THE BIGGEST CAVEAT WILL BE JUST HOW STRONG WINDS ARE DURING THE OVERNIGHT HOURS. IF WINDS FALL TO AROUND 5 TO 10 MPH...ADVECTION FOG COULD BE VERY LIKELY DURING THIS PERIOD. HAVE NOT INCLUDED A MENTION OF FOG IN THE FORECAST YET...DUE TO THE UNCERTAINTY IN PLACE. AVIATION... MOST LOCATIONS ARE VFR WITH CIGS AT OR ABOVE SCT-BKN040...EXCEPT OVC010 AT KMCB. CONVECTION DEVELOPING STEADILY FROM KMCB TO KLFT WITH ANOTHER SURGE OF SHOWERS MOVING INTO KBTR. CIGS SHOULD LOWER TO MVFR LEVELS WITH CONVECTION THIS MORNING...THEN BECOMING PREDOMINANTLY MVFR BASED DURING THE AFTERNOON PRIOR TO WIND SHIFT. CONDITIONS ARE EXPECTED TO IMPROVE TO VFR CAVOK SHORTLY AFTER WIND SHIFT FROM WEST TO EAST. 24/RR MARINE... SOME GRADIENT RESPONSE THIS MORNING HAS WINDS IN THE 15- 20KT RANGE THIS MORNING. AS THE SURFACE LOW CURRENTLY DEVELOPING OVER EAST TEXAS EJECTS NORTHEAST THIS MORNING...WINDS SHOULD LESSEN TO AROUND 15 KNOTS SUSTAINED WHILE VEERING SOUTHWEST. LOW WILL THEN SLINGSHOT A COLD FRONT INTO THE NORTH GULF THIS EVENING WHICH WILL SWEEP EASTWARD RATHER QUICKLY OVERNIGHT. GRADIENT PRE-FRONTAL APPEARS STRONGER THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION. THIS SHOULD REDUCE THE WINDS TO JUST MODERATE LEVELS TONIGHT AND TUESDAY. WINDS AND SEAS SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES WITH BETTER COLD AIR ADVECTION LATE THURSDAY INTO FRIDAY. 24/RR DECISION SUPPORT... DSS CODE....YELLOW. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND MISSISSIPPI RIVER AT RED RIVER LANDING. MARGINAL/SLIGHT RISK OF SEVERE WEATHER MONDAY. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 69 40 71 43 / 90 20 0 0 BTR 72 45 73 45 / 80 20 0 0 ASD 71 44 71 45 / 80 30 10 0 MSY 71 47 68 50 / 70 20 0 0 GPT 68 44 67 45 / 70 40 10 0 PQL 69 40 69 43 / 60 50 10 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...NONE. MS...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1001 AM EST MON FEB 15 2016 .SYNOPSIS... ARCTIC AIR WILL BE SLOW TO ERODE TODAY AS A WARM FRONT OFFSHORE SLOWLY MOVES WESTWARD. THIS FRONT SHOULD MOVE INLAND TONIGHT WITH A SOAKING RAIN EXPECTED INTO EARLY TUESDAY. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF THE WEEK WITH WARM TEMPERATURES DEVELOPING NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM MONDAY...ONLY ISOLATED PATCHES OF LIGHT RAIN OVER THE EXTREME SOUTHERN AND WESTERN PORTIONS OF THE FORECAST AREA AT THIS TIME. THERE HAS BEEN SLIGHT WARMING THE FIRST FEW HOURS AFTER SUNRISE AND AT 9 AM UTC THE SURFACE FREEZING LINE WAS ALONG A LINE FROM HARTSVILLE THROUGH DILLON AND BLADENBORO TO PENDERLEA. SO IF ANY PRECIPITATION FALLS INTO AREAS NORTH OF THIS LINE OVER THE NEXT SEVERAL HOURS PATCHY FREEZING RAINY IS STILL POSSIBLE SO WILL CONTINUE THE FREEZING RAIN ADVISORY. A COASTAL FRONT CONTINUE TO LURK ALONG THE COAST WITH THE ILM TEMPERATURE NOW UP TO 40 DEGREES. THE 14 UTC HRRR SHOW THE COASTAL FRONT MAKING IT ONSHORE AROUND 17 UTC. AS THE FRONT SHIFTS ONTO THE COAST THE ISENTROPIC FLOW CHANCES FOR MORE WIDE SPREAD PRECIPITATION WILL INCREASE AT THE COAST BY THE AFTERNOON AND SPREAD INLAND. ...FROM PREVIOUS DISCUSSION... TEMPERATURES WILL RISE OVERNIGHT AS THE WARM FRONT MAKES MORE RAPID WESTWARD PROGRESS WITH THE TOTAL BREAKDOWN OF THE COLD WEDGE AND ITS SUPPORTING HIGH. THE MOST SUBSTANTIAL RAINFALL SHOULD ARRIVE LATE TONIGHT AS A STRONG 500 MB DISTURBANCE ROLLS ACROSS THE AREA. DEEP MOISTURE AND EVEN SOME ELEVATED CONVECTIVE INSTABILITY SHOULD ENHANCE RAINFALL RATES AND IT`S POSSIBLE 0.50 TO 1.00 INCHES OF RAIN COULD FALL TONIGHT. WITH SURFACE-BASED PARCELS LIKELY TO REMAIN STABLE I AM NOT CONCERNED ABOUT SEVERE WEATHER POTENTIAL...HOWEVER DON`T BE SURPRISED IF THE RADAR SHOWS SEVERAL ROTATING STORMS OUT OVER THE GULF STREAM LATE TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...THE LATEST SPC OUTLOOK CONTINUES TO DISPLAY A MARGINAL RISK FOR SEVERE STORMS FOR PORTIONS OF THE FORECAST AREA TUESDAY MORNING IN ASSOCIATION WITH A PRE-FRONTAL TROUGH/APPROACHING COLD FRONT. AROUND DAYBREAK...GUIDANCE PLACES THE NORTH-SOUTH EXTENDED COLD FRONT ACROSS THE CENTRAL CAROLINAS AS A PRE-FRONTAL TROUGH AHEAD OF THE SYSTEM ESSENTIALLY PLACES OUR FORECAST AREA IN THE WARM SECTOR. WITH PWATS IN THE 1 INCH TO 1.25 INCHES RANGE...ANTICIPATE WIDESPREAD RAINFALL DURING THE MORNING COMMUTE...HEAVY IN NATURE AT TIMES. SEVERE WEATHER WISE...WEAKER LAPSE RATES ALONG WITH COLDER SEA TEMPERATURES AND LACK OF ANY DIURNAL HEATING GIVEN EARLY ONSET OF ACTIVITY WILL RESTRICT INSTABILITY. HOWEVER...WILL NOTE THE HEALTHY LOW LEVEL JET THAT WILL BE IN PLACE OF AROUND 50 KTS AS WELL AS THE LOW LEVEL WIND SHEAR AS NOTED BY THE 0-3KM HELICITY VALUES OF UP TO AROUND 200 M2/S2 POSSIBLE. AS A RESULT...INTERMITTENT DAMAGING WINDS ARE POSSIBLE. AS THE COLD FRONT PUSHES OFFSHORE BY EARLY AFTERNOON...EXPECT IMPROVING CONDITIONS AND A DRYING TREND BEHIND THE SYSTEM FOR THE REST OF THE DAY ON TUESDAY. ANOTHER SHORTWAVE/FRONT WILL PUSH THROUGH LATE OVERNIGHT TUESDAY INTO EARLY WEDNESDAY...BUT DO NOT ANTICIPATE ANY PRECIPITATION WITH THIS FEATURE AS LATEST GUIDANCE KEEPS AVAILABLE MOISTURE NORTH OF THE AREA. MAINLY ABOVE NORMAL TEMPERATURES EXPECTED FOR THE SHORT TERM...WITH HIGHS IN THE MID 60S ON TUESDAY AND AROUND 60 ON TUESDAY. LOW TO MID 40S FOR OVERNIGHT LOWS TUESDAY INTO WEDNESDAY WILL DIP DOWN INTO THE MID TO UPPER 30S AS COLD AIR ADVECTION RAMPS UP BEHIND THE SECONDARY COLD FRONT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...EXPECT A COOL AND DRY START TO THE EXTENDED PERIOD WITH A GRADUAL WARMING TREND THROUGH THE REMAINDER OF THE WEEK AS FAIRLY WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE SOUTHEAST. HIGH TEMPERATURES ON THURSDAY WILL BE JUST BELOW NORMAL IN THE MID TO UPPER 50S...CLIMBING INTO THE MID TO UPPER 60S BY THE WEEKEND AND INTO EARLY NEXT WEEK. OVERNIGHT LOWS START OFF IN THE UPPER 30S...REACHING THE MID TO UPPER 40S. THE ONLY NOTABLE WEATHER SYSTEM WITHIN THE EXTENDED WILL BE TOWARDS THE END OF THE PERIOD...STEMMING FROM A SURFACE LOW PRESSURE SYSTEM WHICH MOVES ACROSS THE NORTHERN GREAT LAKES REGION INTO SOUTHERN CANADA FRIDAY INTO SATURDAY. THOUGH THE TEMPORAL AND SPATIAL NATURE OF THE EXTENDING FRONTAL BOUNDARY INTO THE CAROLINAS REMAINS UNCERTAIN AT THIS TIME...EXPECT INCREASING CLOUDS ON SUNDAY. ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO MONDAY AS A RESULT WILL FALL AS ALL RAIN AS TEMPERATURES REMAIN WELL ABOVE FREEZING. && .AVIATION /15Z MONDAY THROUGH FRIDAY/... AS OF 12Z...VARY LITTLE PRECIP OCCURRING OVER THE CWA RIGHT NOW. THERE WAS A REPORT OF A SNOW/SLEET MIX OVER NORTHERN ROBESON COUNTY...BUT THAT IS IT SO FAR. WITH GOOD WARM AIR ADVECTION JUST OFF THE DECK IN PROGRESS...EXPECTED INLAND TERMINALS TO HAVE OCCASIONAL FREEZING RAIN THROUGH AROUND 14-15Z...WITH VERY LITTLE ACCUMULATION. BY 15Z ALL TERMINALS ARE EXPECTED TO BE ABOVE FREEZING. WINDS WILL SLOWLY VEER TO THE SOUTHEAST THIS AFTERNOON. DID NOT FOCUS MUCH ON THE OVERNIGHT HOURS...HOWEVER EXPECT A SLUG OF WIDESPREAD SHOWERS TO MOVE OVER THE REGION AFTER 06Z. EXTENDED OUTLOOK...BECOMING VFR DURING THE DAY TUESDAY. MVFR CONDITIONS ARE POSSIBLE LATE FRIDAY AND SATURDAY WITH A FRONTAL BOUNDARY MOVING INTO THE VICINITY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM MONDAY...A WARM FRONT CURRENTLY LOCATED 25-40 MILES EAST OF THE BEACHES WILL CRAWL WESTWARD...APPROACHING THE COAST NORTH OF CAPE FEAR AROUND NOON...AND FINALLY REACHING THE SC COAST INCLUDING THE GRAND STRAND BY LATE IN THE DAY. THIS BOUNDARY WILL SEPARATE S TO SE WINDS ON THE EAST (WARM) SIDE FROM NE WINDS ON THE WEST (COLD) SIDE. STRENGTHENING SE WINDS WELL OFFSHORE SHOULD LEAD TO INCREASING SWELL TODAY AND A SMALL CRAFT ADVISORY WILL REMAIN POSTED EVEN FOR AREAS WHERE WIND SPEEDS REMAIN WELL BELOW 25 KNOTS. BY TONIGHT THE WARM FRONT SHOULD MOVE COMPLETELY ONSHORE AND STRENGTHENING SSE WINDS SHOULD REACH 25 KNOTS...ESPECIALLY ACROSS THE WARMER SEA SURFACE TEMPERATURES GREATER THAN 10 MILES FROM SHORE. SWELL WILL CONTINUE TO BUILD AND ITS POSSIBLE WE COULD SEE SEA HEIGHTS EXCEEDING 10 FEET LATE TONIGHT NEAR CAPE FEAR. WAVES OF RAIN DEVELOPING THIS MORNING MAY DIMINISH THIS EVENING...HOWEVER RAIN SHOULD REDEVELOP LATE TONIGHT AND MAY BE ACCOMPANIED BY A FEW STRONG THUNDERSTORMS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT THROUGH TUESDAY AFTERNOON. A PRE-FRONTAL TROUGH WILL PUSH ACROSS THE WATERS TUESDAY MORNING ALLOWING FOR SOUTHERLY WINDS 15 TO 25 KTS TO PREVAIL...FOLLOWED BY A COLD FRONT WHICH PUSHES OFFSHORE JUST TO THE NORTH AND WINDS VEERING SOUTHWESTERLY TO WESTERLY...15 TO 20 KTS. WILL SEE A DECREASE IN SUSTAINED WINDS TO AROUND 10 TO 15 KTS INTO EARLY WEDNESDAY MORNING AS WEAK HIGH PRESSURE BEGINS TO BUILD IN...VEERING WINDS EVEN MORE TO NORTHWEST. ALONG WITH WINDS...SEAS UP TO 6 TO 10 FT WILL WARRANT A SMALL CRAFT ADVISORY FOR THE WATERS THROUGH THE DAY ON TUESDAY...POSSIBLY CONTINUING INTO THE EVENING HOURS. SEAS DROP OFF ON WEDNESDAY TO 3 TO 5 FT. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE WATERS TOWARDS THE END OF THE WEEK. NORTHERLY WINDS 10 TO 15 KTS WILL PREVAIL ON THURSDAY...BECOMING NORTHEASTERLY ON FRIDAY AS HIGH PRESSURE SHIFTS OFFSHORE. SEAS OF 2 TO 4 FT EXPECTED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ017-023-024. NC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NCZ087-096. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST TUESDAY FOR AMZ250-252-254- 256. && $$ NEAR TERM...DRH/TRA SHORT TERM...SGL LONG TERM...SGL AVIATION...DL
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
824 AM CST MON FEB 15 2016 .UPDATE... ISSUED AT 823 AM CST MON FEB 15 2016 GETTING A SMALL BAND OF SNOW SHOWERS THAT JUST PASSED THROUGH THE OFFICE...ONLY A DUSTING BUT HEAVY SNOW FOR ABOUT 15 MIN. HAVE ADDED POPS FOR THIS AND TIMED IT OUT OF THE EAST BY 18Z USING TIME/DISTANCE METHOD. FOR NOW NO OTHER CHANGES. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CST MON FEB 15 2016 FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE BLEND FOR NOW. A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF CLOUD COVER. NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST SW OF THE FA. FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING COOLER TEMPERATURES TO THE REGION TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CST MON FEB 15 2016 NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO. HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY. WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD. THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID- LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER AIR FEATURES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 626 AM CST MON FEB 15 2016 ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE AFTERNOON/EVENING AS NEXT WAVE DROPS SE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...MAKOWSKI/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
631 AM CST MON FEB 15 2016 .UPDATE... ISSUED AT 626 AM CST MON FEB 15 2016 EXPANDED THE AREA BUT TRIMMED LOW POPS TO FLURRIES AS METARS NOT INDICATING ANY LOWERING OF VSBY IN SNOW. NO OTHER CHANGES MADE. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CST MON FEB 15 2016 FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE BLEND FOR NOW. A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF CLOUD COVER. NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST SW OF THE FA. FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING COOLER TEMPERATURES TO THE REGION TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CST MON FEB 15 2016 NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO. HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY. WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD. THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID- LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER AIR FEATURES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 626 AM CST MON FEB 15 2016 ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE AFTERNOON/EVENING AS NEXT WAVE DROPS SE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...VOELKER SHORT TERM...VOELKER LONG TERM...MAKOWSKI/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
651 AM EST MON FEB 15 2016 .SYNOPSIS... COLD ARCTIC HIGH PRESSURE LOCATED OVER NEW ENGLAND AND RIDGING DOWN ACROSS THE CAROLINAS WILL MOVE EAST AND OVER THE ATLANTIC TODAY. MEANWHILE...A MOIST STORM SYSTEM WILL CROSS OUR AREA FROM THE WEST TONIGHT AND TUESDAY. A FAST MOVING UPPER LEVEL SYSTEM WILL REACH THE MOUNTAINS LATE TUESDAY...BEFORE DRY AND MILDER HIGH PRESSURE RETURNS AND REMAINS THROUGH THE END OF THE WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM EST...A BAND OF UPGLIDE INDUCED PRECIPITATION HAS STARTED BREAKING OUT ACROSS WESTERN NORTH CAROLINA EARLY THIS MORNING...BUT ANY PRECIP HAS BEEN MUCH SPOTTIER IN SOUTHERN SECTIONS. STILL ANTICIPATE A GRADUAL INCREASE IN PRECIP COVERAGE ACROSS THE REGION THROUGH THE MORNING HOURS AS ATLANTIC AND GULF MOISTURE SLOWLY FILL IN AND ISENTROPIC LIFT GRADUALLY IMPROVES. MEANWHILE...WATER VAPOR IMAGERY SHOWS AN UPSTREAM TROUGH DIGGING TOWARD THE LOWER MS RIVER VALLEY THROUGH THE DAY...WHILE A 1034 MB SURFACE HIGH PRESSURE SLIPS EAST OFF THE DELMARVA COAST BUT CONTINUES TO EXTEND A RIDGE AXIS SOUTHWARD ACROSS THE FORECAST AREA IN A FAVORABLE COLD AIR DAMMING CONFIGURATION. TEMPERATURES REMAIN MOSTLY IN THE 20S WITH DEWPOINTS IN THE TEENS. IN ADDITION...WET BULB PROFILES ON THE LATEST RAP SHOW ONLY A VERY MODEST WARM NOSE ACROSS THE REGION. THIS REMAINS A GOOD SETUP FOR FREEZING/FROZEN PRECIPITATION THROUGHOUT ACROSS THE NORTHERN TIER...WITH MAINLY FZRA SOUTH. ALTHOUGH ISENTROPIC LIFT IS EXPECTED TO STEADILY ACTIVATE ACROSS THE REGION TODAY AHEAD OF THE DIGGING WAVE...THE NUMERICAL MODELS REMAIN SOMEWHAT STINGY ON QPF FOR MUCH OF THE DAY...WITH BETTER AMOUNTS JUST NORTH AND WEST OF THE CWFA. THE QUANDARY FOR THE IMMEDIATE NEAR TERM IS THAT VERY COLD/DRY AIR IS IN PLACE BUT WE WILL HAVE LESS QPF TO WORK WITH. STILL ANTICIPATE THE DEVELOPING WARM NOSE IN THE IMPROVING WARM ADVECTION TO WORK NORTHWARD ACROSS THE REGION TODAY...AND MOST LOCATIONS WILL SEE A 12Z TO 18Z TRANSITION OF ANY PRECIPITATION THAT IS FALLING FROM FROZEN TO FREEZING PTYPES. ALTHOUGH ONLY VERY LIGHT QPF WILL IMPACT THE LOWER PIEDMONT...THE FREEZING RAIN ADVISORY HAS BEEN EXPANDED TO THE ABBEVILLE TO CHESTER TIER SINCE ANY PRECIPITATION AT ALL WILL QUICKLY CREATE A GLAZE ON COLD SURFACES. ANOTHER ADJUSTMENT WAS TO PERMIT THE ADVISORY FOR GRAHAM/SWAIN TO EXPIRE AT 18Z SINCE THE SOUTHWEST MOUNTAINS WILL BE THE FIRST TO TRANSITION OVER TO RAIN THROUGH MIDDAY AS THE WARM NOSE ARRIVES...PLUS THERE WILL BE NO SURFACE COLD LAYER THERE OUTSIDE OF THE DAMMING REGION. OTHERWISE...THE NORTHERN NC BLUE RIDGE AND ADJACENT FOOTHILL AREAS WILL BE THE LAST HOLDOUT FOR ANY APPRECIABLE SNOW/SLEET INTO THE AFTERNOON HOURS. THE INCREASINGLY NEGATIVE TILT UPPER WAVE WILL BE ON THE MOVE ACROSS THE DEEP SOUTH AND IT SHOULD LIFT ACROSS THE REGION TONIGHT TO PROVIDE THE BEST PERIOD OF DEEP MOISTURE AND FORCING. THE HEAVIEST PRECIPITATION SHOULD WRAP INTO THE AREA AHEAD OF THE ADVANCING SURFACE LOW CENTER THIS EVENING. THE GFS/ECMWF TAKE THIS SURFACE LOW WEST OF THE MOUNTAINS...BUT THE NAM HAS A CIRCULATION MOVING EAST OF THE MOUNTAINS ALONG THE WEDGE BOUNDARY...AND IT IS LIKELY ONTO SOMETHING THERE. FREEZING TEMPERATURES COULD THUS BE LOCKED IN FOR A GOOD CHUNK OF THE NORTHERN PART OF FORECAST AREA INTO THE EARLY EVENING...AND THIS WILL BOOST ICE ACCUMULATIONS ESPECIALLY OVER THE NC FOOTHILLS AND EASTERN BLUE RIDGE AS THE BETTER QPF ARRIVES. ANTICIPATE DRY SLOTTING WRAPPING FROM THE SW AFTER 09Z...BUT WITH NW FLOW MOISTURE CONTINUING ACROSS THE WESTERN MOUNTAINS THROUGH DAYBREAK TUESDAY. THE WARNING FOR THE NORTHERN MOUNTAINS COULD NEED SOME EXTENSION IF MIXED PTYPES PERSIST ON THE NW FLOW...BUT WILL LEAVE IT AT MIDNIGHT FOR NOW. WILL CONTINUE TO OMIT ANY PIEDMONT THUNDER CHANCES TONIGHT AS IT APPEARS THAT THE BETTER SURFACE BASED INSTABILITY WILL PASS JUST SOUTHEAST OF THE FORECAST AREA OVERNIGHT. ALSO...HYDRO PROBLEMS WILL LIKELY BE LIMITED BY THE SHORT DURATION...GENERALLY 00Z TO 09Z...OF THE MODERATE TO BRIEFLY HEAVY RAINFALL WITH THE PASSING TROUGH. && .SHORT TERM /TUESDAY THROUGH THURSDAY/... AS OF 250 AM MONDAY...THE SHORT TERM PICKS UP AT 12Z TUESDAY...WITH MODELS IN PRETTY GOOD AGREEMENT ON THE AXIS OF A NEGATIVELY-TILTED 500 MB TROUGH BISECTING THE CWFA. THE DRY SLOT OF THIS STORM SYSTEM WILL HAVE PUNCHED INTO THE AREA BY AROUND DAYBREAK TUESDAY...SO POP WILL QUICKLY TAPER OFF FROM WEST TO EAST. THERE WILL BE SOME LINGERING SLIGHT TO LOW-END CHANCE POPS IN THE NC MOUNTAINS...BUT OTHERWISE THINGS SHOULD BEGIN TO DRY OUT. ANOTHER POTENT SHORT WAVE WILL BE DIVING THRU THE BASE OF THE LONG WAVE TROUGH TUESDAY EVENING...KEEPING FLOW BACKED OUT OF THE SW...AND BRINGING A BRIEF SHOT OF MOISTURE. SO EXPECT SOME SUNSHINE EAST OF THE MOUNTAINS FROM LATE MORNING TO EARLY AFTERNOON...BUT QUICKLY CLOUDING BACK UP WITH THE APPROACHING WAVE. THE FORECAST SOUNDINGS SHOW STEEPENING LOW-MID LEVEL LAPSE RATES...SO ANY LINGERING PRECIP SHOULD TRANSITION BACK TO MAINLY HIGH-ELEVATION SNOW AND LOWER RAIN. HIGHS WILL BE JUST BELOW NORMAL. TUESDAY NIGHT...AS THE UPPER WAVE EXITS TO THE EAST...LOW LEVEL FLOW TURNS OUT OF THE NW FOR A BRIEF NWFS EVENT. CONDITIONS DO NOT LOOK THAT IMPRESSIVE FOR ANYTHING MORE THAN AN INCH OR TWO OF SNOW OVERNIGHT...MAINLY ABOVE 3500 FT. SINCE ADVISORY IS TWO INCHES IN 12 HOURS...WILL PLAN TO MENTION SNOW IN HWO FOR THE TN BORDER COUNTIES. OTHERWISE...EXPECT ANY PRECIP EAST OF THE MOUNTAINS TO QUICKLY END BY LATE EVENING...WITH TEMPS FALLING INTO THE MID TO UPPER 30S. WEDNESDAY THRU WEDNESDAY NIGHT...THE EASTERN CONUS TROUGH WILL BE REINFORCED BY YET ANOTHER SHORT WAVE DIVING THRU IT...BUT THE WAVE SHOULD HAVE LITTLE MOISTURE TO WORK WITH. PERHAPS A FEW SNOW SHOWERS OR FLURRIES ALONG THE TN LINE...MAINLY WEDNESDAY EVENING. OTHERWISE...SOME INCREASE IN CLOUDS AND TEMPS STAYING JUST SLIGHTLY BELOW NORMAL. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... AS OF 310 AM MONDAY...THE LONG TERM STARTS OUT 12Z THURSDAY...WITH A MILDER POLAR AIR MASS THAN WE HAVE SEEN THE LAST COUPLE WEEKS ACROSS THE REGION. STILL...THURSDAY LOOKS COOL UNDER SUNNY SKIES. HIGHS A CATEGORY OR TWO BELOW NORMAL. FRIDAY THRU THE NEXT WEEKEND...UPPER LEVEL FLOW BECOMES QUASI-ZONAL...RESULTING IN NEAR NORMAL TO ABOVE NORMAL TEMPS FOR THE FIRST TIME SINCE THE BEGINNING OF THIS MONTH. A CLIPPER SYSTEM WILL CROSS THE GREAT LAKES...PUSHING A COLD FRONT ACROSS THE CWFA...BUT WITH LITTLE MOISTURE FRIDAY NIGHT. THE 00Z GFS AND ECMWF BEGIN TO DIVERGE BY SUNDAY...WITH THE GFS SHOWING A ZONALLY-ORIENTED FRONT PROVIDING INCREASED PRECIP CHANCES...WHILE THE ECMWF IS MORE AMPLIFIED AND SLOWER TO BRING THE FRONT AND PRECIP IN FROM THE WEST. FOR NOW...I WILL FORECAST SLIGHT TO MID CHANCE FOR RAIN RETURNING FROM THE WEST SUNDAY AFTERNOON THRU SUNDAY NIGHT. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... AT KCLT...MVFR CLOUDS ARE SOLIDLY IN PLACE AT THE AIRFIELD THIS MORNING...BUT THE UPGLIDE PRECIPITATION BAND HAS REMAINED JUST NORTH OF THE VICINITY THUS FAR. ANY FURTHER DEGRADATION IN CONDITIONS WILL BE VERY SLOW TO DEVELOP THROUGH THE MORNING AS MOIST UPGLIDE SLOWLY BUILDS. WILL TEMPO IN -FZRA AND SLEET FOR A FEW HOURS...BUT THE ENCROACHING WARM NOSE WILL SUPPORT MAINLY -FZRA GOING FORWARD AFTER ABOUT 15Z. CEILINGS WILL TRANSITION DOWN INTO MORE SOLID IFR THROUGH THE AFTERNOON HOURS...WITH STEADIER RAIN AND LIFR CONDITIONS LIKELY THIS EVENING AS THE LOW APPROACHES FROM THE WEST. THE GRADUAL EROSION OF COLD AIR DAMMING TONIGHT SHOULD UNCOVER LLWS CONDITIONS BY LATE EVENING. SURFACE WINDS WILL BE MAINLY NE LESS THAN 10 KT THROUGH THE PERIOD...BUT BECOMING STRONGER SOUTHERLY NEAR THE END OF THE TAF PERIOD AS THE WEDGE BOUNDARY LIFTS THROUGH. ELSEWHERE...SNOW...SLEET...AND FREEZING RAIN WILL BE ON THE INCREASE ACROSS THE NC TAF SITES THIS MORNING...BUT WITH ONLY A GRADUAL UPTICK IN UPGLIDE PRECIPITATION ACROSS THE SC SITES. EXPECT MAINLY FREEZING RAIN WITH ANYTHING THAT FALLS FROM LATE MORNING ONWARD...ALTHOUGH SLEET COULD LINGER AT KHKY. THE PRECIP WILL TRANSITION TO RAIN FROM THE SOUTH THROUGH LATE DAY...BUT FREEZING RAIN COULD LINGER INTO THE EVENING IN THE NARROWING CAD REGION FROM KGSP TO KHKY. CEILINGS WILL TRANSITION DOWN SLOWLY THROUGH MVFR... REACHING IFR BY LATE MORNING INTO EARLY AFTERNOON...AND LIFR LIKELY BY EVENING AS THE HEAVIER RAINFALL SPREADS IN FROM THE WEST. EXPECT MAINLY NE WINDS LESS THAN 10 KT IN THE CAD LAYER...BUT WITH SE TO SOUTHERLY FLOW DEVELOPING LATE...WITH LOW END GUSTS...AND SE FLOW PERSISTING INTO THE FRENCH BROAD VALLEY NEAR KAVL. OUTLOOK...THE PASSING SURFACE LOW AND UPPER LEVEL TROUGH WILL LIFT THROUGH THE REGION EARLY TUESDAY MORNING TO GRADUALLY TAPER OFF PRECIPITATION. RESTRICTIONS COULD LINGER THROUGH TUESDAY IN SOME PLACES GIVEN THE NEAR GROUND MOISTURE. ANOTHER TROUGH WILL CROSS THE REGION TUESDAY NIGHT...WITH ADDITIONAL WINTRY PRECIPITATION AND RESTRICTIONS POSSIBLE MAINLY AT KAVL. OTHERWISE...EXPECT DRYING THROUGH THE WEEK. CONFIDENCE TABLE... 12-18Z 18-24Z 00-06Z 06-12Z KCLT HIGH 83% MED 67% HIGH 87% HIGH 92% KGSP HIGH 84% MED 76% HIGH 87% MED 79% KAVL HIGH 85% HIGH 88% HIGH 94% HIGH 90% KHKY HIGH 86% HIGH 87% HIGH 92% HIGH 85% KGMU HIGH 83% MED 78% HIGH 81% MED 76% KAND HIGH 95% MED 70% HIGH 82% MED 75% THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: WWW.WEATHER.GOV/GSP/AVIATION && .GSP WATCHES/WARNINGS/ADVISORIES... GA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR GAZ010- 017. FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR GAZ018- 026-028. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR GAZ029. NC...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NCZ033-035- 049-050-501>506. WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ048- 052-057-059-062>064-071-072. FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ082. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ036- 037-053-056-065-068>070-507>510. WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NCZ051-058. SC...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR SCZ001- 002. FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR SCZ004>010-012>014. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR SCZ003. FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ011-019. && $$ SYNOPSIS...DEO NEAR TERM...HG SHORT TERM...ARK LONG TERM...ARK AVIATION...HG
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
602 AM CST MON FEB 15 2016 .AVIATION... /12Z TAFS/ LIFR/VLIFR VBSYS AND CIGS ARE AFFECTING AREAS ALONG THE I-35 CORRIDOR. THESE CONDITIONS ARE EXPECTED TO IMPROVE LATER THIS MORNING AS A COLD FRONT PUSHES THROUGH THE AREA. A WIND SHIFT FROM THE NORTHWEST TO NORTH IS EXPECTED ACROSS KAUS/AND KATT AROUND 14 TO 15Z AND ACROSS KSAT BETWEEN 15Z TO 16Z IH. IN THE WAKE OF THE FRONT...WINDS WILL BE FROM THE NORTHWEST TO NORTH. BREEZY NORTHERLY WINDS WILL PREVAIL FOR MUCH OF THE AFTERNOON WITH GUSTS UP TO 25 KNOTS. VFR CONDITIONS ARE ANTICIPATED FOR THE EVENING AND LATE TONIGHT. && .PREV DISCUSSION... /ISSUED 402 AM CST MON FIB 15 2016/ SHORT TERM (TODAY THROUGH TUESDAY)... MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED TODAY AND TUESDAY. WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH- CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE FRONT THAT IS NOW LOCATED ALONG A DALL`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
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
440 AM CST MON FEB 15 2016 .AVIATION... VFR. LIGHT NW WINDS BECMG SWLY AROUND 11 KNOTS BY MIDDAY. && .PREV DISCUSSION... /ISSUED 339 AM CST MON FEB 15 2016/ SHORT TERM... IN THE WAKE OF A MINOR TROUGH THAT MANAGED TO GENERATE MID-LEVEL CLOUDS AND VIRGA OVER OVER THE SERN PANHANDLE LAST NIGHT...BROAD SURFACE RIDGING CENTERED IN NERN NM WILL TRANSLATE SEWD UNDER DRY NW FLOW. DEPARTURE OF THIS RIDGE BY LATE MORNING AND SUBSEQUENT DOWNSLOPE FLOW WILL AID IN LEE TROUGH DEVELOPMENT OVER EASTERN NM COMPLETE WITH SOME BREEZY W-SW WINDS LOCALLY. CONTINUE TO SIDE WITH THE DRIER RUC AND HRRR FOR AFTERNOON DEWPOINTS AS REMAINING GUIDANCE HAS BEEN TOO GENEROUS WITH THESE IN RECENT DAYS...IF NOT WEEKS. UPSHOT OF THIS IS THAT MILDER MAV HIGH TEMPS REMAIN FAVORED OVER THE COOL SUPERBLEND. SW WINDS TONIGHT WILL VEER W-NW BEFORE DAYBREAK TUE IN ADVANCE OF A DECAYING COLD FRONT AND DISTANT TROUGH TRACKING ALONG THE MIDDLE MISSOURI RIVER VALLEY. LONG TERM... QUIET WEATHER WILL CONTINUE THROUGH MUCH OF THE WEEK AS DRY NORTHWEST FLOW GRADUALLY TRANSITIONS TO SOUTHWESTERLY/ZONAL BY THE END OF THE WEEK. A WEAK FRONT WILL PUSH THROUGH EARLY TUESDAY KEEPING TEMPERATURES IN THE MID 60S TO LOW 70S FOR HIGHS AND LOWS IN THE MID 30S TO LOWER 40S. RIDGE WILL MOVE OVER THE REGION ON WEDNESDAY WHICH WILL START WARMING TEMPERATURES WELL ABOVE NORMAL FOR MID-WEEK. WARMEST DAY STILL LOOKS TO BE THURSDAY WHEN SOUTHWESTERLY FLOW WILL DEVELOP AT THE SURFACE HELPING TO BOOST HIGHS INTO THE LOW 80S. WEAK SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE FRIDAY THROUGH THE END OF THE FORECAST. THIS WILL KEEP BOUNDARY LAYER MOISTURE IN PLACE EITHER OVER OR NEAR THE FORECAST AREA THROUGH SOME POINT OVER THE WEEKEND OR FIRST PART OF NEXT WEEK. THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE ARRIVAL OF A COLD FRONT AT THE END OF THE UPCOMING WEEKEND OR FIRST PART OF NEXT WEEK. DIFFERENCES SURROUND THE STRENGTH OF A WAVE/CLOSED LOW THAT SWINGS OUT ACROSS THE NORTHERN PLAINS OVER THE GREAT LAKES. ECMWF DEVELOPS A CLOSED LOW RESULTING IN A STRONGER FRONT THAT PUSHES THROUGH ON SUNDAY WHILE THE GFS IS MUCH WEAKER THAN THE ECMWF. MODELS TRY TO BREAK OUT PRECIPITATION IN VARYING AMOUNTS AND COVERAGE AND SUPERBLEND OUTPUT CONTINUES TO CARRY POPS FOR SATURDAY INTO SUNDAY. BECAUSE OF THE DIFFERENCES IN THE MODELS... ECMWF IS MUCH DRIER THAN THE GFS...WILL KEEP POPS OUT OF THE FORECAST FOR NOW UNTIL WE SEE IF THE EXTENDED RANGE FORECAST CAN COME INTO BETTER CONSENSUS. JORDAN && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 93/14/93
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1201 PM CST MON FEB 15 2016 .UPDATE... ISSUED AT 1035 AM CST MON FEB 15 2016 Will update the forecast around 11 am and plan to end the dense fog advisory about one hour early. Still have a few pockets of dense fog at 10 am at Bloomington, Lawrenceville, Mattoon, Taylorville and Litchfield. Visibilities have been slowly improving late this morning and expect this trend to continue into midday. A low overcast with bases around or less than 500 feet cover much of IL late this morning. There are some large breaks in the low clouds over MO and these should lift ne into central IL during the afternoon especially sw CWA. Highs this afternoon in the low to mid 30s with mildest readings sw CWA where more breaks in low clouds expected. Winds to stay fairly light today, sw less then 10 mph. Upper level trof from the upper MS river valley into western MO and near OK/AR border to push east into IL this evening. 1009 mb surface low pressure along the LA/MS border to deepen ne into northern AL at 1003 mb by 00Z/6 pm and keeps it precipitation se of the Ohio river. The upper level trof will tend to keep low clouds around central/se IL this afternoon and evening with mostly cloudy to overcast skies. && .SHORT TERM...(Today) ISSUED AT 314 AM CST MON FEB 15 2016 08z/2am radar imagery continues to indicate patchy freezing drizzle across central Illinois: however, the areal coverage and intensity has decreased markedly from earlier in the evening. As light southerly winds flow over the cold/snow-covered ground, expect fog and perhaps some drizzle to persist through the morning. Current visibilities are mostly in the 2-5 mile range, but HRRR suggests the potential for even lower visbys as WAA continues and low overcast lifts. Have seen a few reports of 1/4 mile visbys upstream across central Missouri where clouds have temporarily cleared and expect the fog to thicken/spread northeastward into central Illinois over the next few hours. Will need to carefully monitor trends, as a Dense Fog Advisory could be needed if HRRR verifies. For now, will just mention areas of fog in the forecast through midday. A weak short-wave trough evident on latest water vapor imagery over eastern Nebraska will pass to the W/SW of the area today. A small area of light snow associated with this feature over southwest Iowa will spread across northern Missouri and may approach the far SW CWA toward midday: however, all high-res models show the precip dissipating before arriving. Have therefore gone with a dry forecast. Despite continued southerly flow, fog and extensive cloud cover will keep afternoon high temperatures in the middle to upper 30s. .LONG TERM...(Tonight through Sunday) ISSUED AT 314 AM CST MON FEB 15 2016 The next fast-moving storm system embedded within the prevailing northwesterly flow aloft will arrive late tonight into Tuesday, bringing another period of wintry precip to central Illinois. 00z Feb 15 models have all trended south with the track of this system, with the NAM being the furthest north and the GEM the furthest south. Have rejected these two solutions in favor of the middle of the road GFS, which takes the 500mb vort max from northern Missouri 12z Tue to far southern Illinois by 18z Tue. Given this particular track, the heaviest precip will be focused across the central/southern CWA. Have therefore reduced PoPs into the chance category along/north of I-74...while maintaining likely further south across the remainder of the area. Another consequence of a further south track is a slightly colder thermal profile. GFS forecast soundings are generally cold enough for snow initially as the max temp in the elevated warm layer only reaches about 1C. As a result, am expecting snow Tuesday morning, gradually transitioning to a rain/snow mix by afternoon as surface temps rise into the middle to upper 30s. Due to the southward track shift, relatively light precip, and marginal temps...snow accumulations are expected to remain minor. Will see a band of around 1 inch along/southwest of a Canton...to Decatur...to Marshall line...with less than one half inch north of I-74. Another weak short-wave will pass through the region on Wednesday: however, this feature will be moisture-starved and will produce little more than some cloud cover. Once this wave exits, upper heights will begin to rise in earnest in response to a major system coming onshore along the Pacific Coast. Downstream ridging across the central and eastern CONUS will allow a pronounced warming trend to occur by the end of the week. Models have been consistently advertising temps reaching the upper 40s and lower 50s by Thursday, then climbing into the upper 50s and lower 60s on Friday. A weak cold front is still progged to pass through Illinois on Friday, but with only limited moisture to work with, will only mention slight chance for showers with FROPA. After that, temps cool a bit over the weekend, but remain above normal in the 50s for both Saturday and Sunday. && .AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon) ISSUED AT 1159 AM CST MON FEB 15 2016 Widespread fog still lingers across central IL airports at midday with visibilities ranging from 1/8 mile at BMI, 1/2 mile at CMI while PIA, SPI and DEC up to 2-3 miles. Vsbys to gradually lift to MVFR next few hours while ceilings of 100-500 ft nudge up to 500-1k ft later this afternoon. Ceilings could even lift to low end MVFR for a time later this afternoon and evening especially sw airports but think ceilings will lower back down to IFR overnight into Tue morning. Yet another northern stream short wave/trof over northern high plains to dive quickly se into the mid MS river valley by 18Z/noon Tue. Best chances of light snow will be over sw IL Tue morning and carried 3 miles light snow at SPI and DEC while just vcsh along I-74 taf sites. Winds stay fairly light next 24 hours from sw direction this afternoon and veering east by Tue morning. && .ILX Watches/Warnings/Advisories... NONE. && $$ UPDATE...07 SHORT TERM...Barnes LONG TERM...Barnes AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1040 AM CST MON FEB 15 2016 .UPDATE... ISSUED AT 1035 AM CST MON FEB 15 2016 Will update the forecast around 11 am and plan to end the dense fog advisory about one hour early. Still have a few pockets of dense fog at 10 am at Bloomington, Lawrenceville, Mattoon, Taylorville and Litchfield. Visibilities have been slowly improving late this morning and expect this trend to continue into midday. A low overcast with bases around or less than 500 feet cover much of IL late this morning. There are some large breaks in the low clouds over MO and these should lift ne into central IL during the afternoon especially sw CWA. Highs this afternoon in the low to mid 30s with mildest readings sw CWA where more breaks in low clouds expected. Winds to stay fairly light today, sw less then 10 mph. Upper level trof from the upper MS river valley into western MO and near OK/AR border to push east into IL this evening. 1009 mb surface low pressure along the LA/MS border to deepen ne into northern AL at 1003 mb by 00Z/6 pm and keeps it precipitation se of the Ohio river. The upper level trof will tend to keep low clouds around central/se IL this afternoon and evening with mostly cloudy to overcast skies. && .SHORT TERM...(Today) ISSUED AT 314 AM CST MON FEB 15 2016 08z/2am radar imagery continues to indicate patchy freezing drizzle across central Illinois: however, the areal coverage and intensity has decreased markedly from earlier in the evening. As light southerly winds flow over the cold/snow-covered ground, expect fog and perhaps some drizzle to persist through the morning. Current visibilities are mostly in the 2-5 mile range, but HRRR suggests the potential for even lower visbys as WAA continues and low overcast lifts. Have seen a few reports of 1/4 mile visbys upstream across central Missouri where clouds have temporarily cleared and expect the fog to thicken/spread northeastward into central Illinois over the next few hours. Will need to carefully monitor trends, as a Dense Fog Advisory could be needed if HRRR verifies. For now, will just mention areas of fog in the forecast through midday. A weak short-wave trough evident on latest water vapor imagery over eastern Nebraska will pass to the W/SW of the area today. A small area of light snow associated with this feature over southwest Iowa will spread across northern Missouri and may approach the far SW CWA toward midday: however, all high-res models show the precip dissipating before arriving. Have therefore gone with a dry forecast. Despite continued southerly flow, fog and extensive cloud cover will keep afternoon high temperatures in the middle to upper 30s. .LONG TERM...(Tonight through Sunday) ISSUED AT 314 AM CST MON FEB 15 2016 The next fast-moving storm system embedded within the prevailing northwesterly flow aloft will arrive late tonight into Tuesday, bringing another period of wintry precip to central Illinois. 00z Feb 15 models have all trended south with the track of this system, with the NAM being the furthest north and the GEM the furthest south. Have rejected these two solutions in favor of the middle of the road GFS, which takes the 500mb vort max from northern Missouri 12z Tue to far southern Illinois by 18z Tue. Given this particular track, the heaviest precip will be focused across the central/southern CWA. Have therefore reduced PoPs into the chance category along/north of I-74...while maintaining likely further south across the remainder of the area. Another consequence of a further south track is a slightly colder thermal profile. GFS forecast soundings are generally cold enough for snow initially as the max temp in the elevated warm layer only reaches about 1C. As a result, am expecting snow Tuesday morning, gradually transitioning to a rain/snow mix by afternoon as surface temps rise into the middle to upper 30s. Due to the southward track shift, relatively light precip, and marginal temps...snow accumulations are expected to remain minor. Will see a band of around 1 inch along/southwest of a Canton...to Decatur...to Marshall line...with less than one half inch north of I-74. Another weak short-wave will pass through the region on Wednesday: however, this feature will be moisture-starved and will produce little more than some cloud cover. Once this wave exits, upper heights will begin to rise in earnest in response to a major system coming onshore along the Pacific Coast. Downstream ridging across the central and eastern CONUS will allow a pronounced warming trend to occur by the end of the week. Models have been consistently advertising temps reaching the upper 40s and lower 50s by Thursday, then climbing into the upper 50s and lower 60s on Friday. A weak cold front is still progged to pass through Illinois on Friday, but with only limited moisture to work with, will only mention slight chance for showers with FROPA. After that, temps cool a bit over the weekend, but remain above normal in the 50s for both Saturday and Sunday. && .AVIATION...(For the 12Z TAFS through 12Z Tuesday morning) ISSUED AT 510 AM CST MON FEB 15 2016 IFR to VLIFR conditions in low clouds and vsbys expected through at least 16z before conditions slowly improve into the afternoon hours. Widespread IFR and LIFR conditions prevailed early this morning due to high moisuture levels in the low levels of the atmosphere. Weak high pressure will push across the area today with forecast soundings indicating a low level inversion in place effectively trapping the moisture through early this afternoon. Will start to take the cigs up above 1000 feet after 16-18z but confidence on that occurring is low at this particular time. Latest short term guidance suggests the lowest vsbys will be along and especially south of I-72 which should include SPI and DEC. However, experience has shown that with these light southerly flow regimes, coupled with a fresh snow cover, BMI has a tendency to stay rather low with the cigs and vsbys and is slow to recover. Will trend in that direction thru at least the morning hours. IFR with some low MVFR cigs expected this evening and overnight with the next weather system moving in after 08z, and affecting mainly the SPI TAF. At this point, will include a VCSH with a threat for some light snow developing before dawn. Surface winds will not be much of a factor through tonight with a light southerly to southwesterly flow today with speeds of less than 10 kts, becoming light south to southeast late tonight. && .ILX Watches/Warnings/Advisories... Dense Fog Advisory until noon CST today for ILZ027>031-036>038- 040>057-061>063-066>068-071>073. && $$ UPDATE...07 SHORT TERM...Barnes LONG TERM...Barnes AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Paducah KY
1140 AM CST MON FEB 15 2016 .UPDATE... Issued at 1140 AM CST MON FEB 15 2016 The AVIATION section has been updated for the 18Z TAF issuance. && .SHORT TERM...(Today through Wednesday) Issued at 255 AM CST MON FEB 15 2016 Scattered light showers continue to stream northeast just clipping southeastern Todd county Kentucky, but based on the KCKV and KBWG METARs this area should be just above freezing. Will therefore let the Winter Weather Advisory expire as scheduled at 3 AM. Elsewhere across the forecast area, most observation sites have visibilities between 1 and 3 miles with light fog, and a few patches of very light freezing drizzle. Weak, drizzly echoes on radar at Midnight have mostly dried up, so doubt there will be much, if any, additional icing this morning. However, will re- issue an SPS mainly to highlight slick driving conditions through the morning commute. The 00Z WRF and most recent HRRR runs keep the shower activity along the TN border through the morning, and then lift it back up over more of west Kentucky this afternoon before pushing east of the area early this evening. Given this timing, temperatures should be above freezing, so there should be no wintry concerns after the sun gets sufficiently high in the sky this morning. The 00Z models bring a compact, intense upper low into the base of the upper trough over the region on Tuesday. The 00Z consensus keeps any QPF northwest of the area through daybreak, but we will have to watch for the potential for either freezing rain or snow with the onset of precipitation in the morning. Model soundings across the northeast show a warm layer only near the surface, so it is conceivable that we will have to monitor for snow through the day as this system passes. Temperatures should be above freezing, so accumulations will be hard to come by even if the snow reaches the ground. This system should exit to the east at or shortly after 00Z Wednesday. Yet another upper-level disturbance will dive southeast into our region for Wednesday, as we continue to be heavily influenced by cyclonic flow aloft. The models are not generating any precipitation with this activity, but it should keep most of the area rather cloudy. .LONG TERM...(Wednesday Night through Sunday) Issued at 255 AM CST MON FEB 15 2016 By Wednesday into Thursday, we will finally be seeing a shift in the upper level pattern, as an upper level ridge builds overhead. As this occurs, we will see quiet weather along with a decent warmup, that has been advertised for quite a while now. Warm air advection will begin in earnest Wednesday night and the entire area will see 850mb temps back above zero by late Thursday morning or afternoon. We should see highs on Thursday well into the 50s per the latest guidance, 2m temps and soundings. We should see 60s by Friday with our far western counties in SEMO maybe touching or getting close to 70 degrees. In fact, even warmer weather will only be a state away, as newest guidance indicating highs around 80 in northeast Oklahoma. Hard to imagine when you`re currently only sitting at 31 degrees. Meanwhile, in the northern Plains, an upper level shortwave will be moving eastward into the Great Lakes Thursday night into Friday. As this occurs, a weak front at the surface will be moving into our area. Moisture still appears to be rather scant but the GFS still tries to eek out some QPF. Whatever does fall, if anything, will be light. But since POPS have already been taken out, will continue with that idea and leave it dry, but will have to keep watching, as the GFS ensembles continue to indicate a few hundredths of QPF with the FROPA. The front dives south but only makes into the Gulf Coast State before stalling out. Models indicate that the front will lift back north toward the area as early as Saturday night. However, Saturday should be a dry day with temperatures remaining in the 60s. Another weak frontal boundary will develop to our west and will move through on Sunday, which means we will continue with the chance for rain. The front should be exiting the area sometime on Sunday night. Could even see some isolated thunderstorms on Saturday night into Sunday as some of the parameters are hinting at it. && .AVIATION... Issued at 1140 AM CST MON FEB 15 2016 Abundant low level moisture coupled with a very strong inversion have produced LIFR/IFR conditions across all sites today. We expect slight improvements later this afternoon and into the early overnight hours. Beyond that cigs/vsbys are expected to drop back to LIFR/IFR along with the possibility of light FZDZ. FZDZ should only last a couple of hours and quickly change to rain before the end of the period. Winds calm to light and variable will come around to the southeast AOB 5 knots by the end of the period. && .PAH Watches/Warnings/Advisories... IL...Dense Fog Advisory until 2 PM CST this afternoon for ILZ077-078- 082-083-085>094. MO...Dense Fog Advisory until 2 PM CST this afternoon for MOZ110>112- 114. IN...Dense Fog Advisory until 2 PM CST this afternoon for INZ081-082- 085>088. KY...Dense Fog Advisory until 2 PM CST this afternoon for KYZ001>022. && $$ SHORT TERM...DRS LONG TERM...CW AVIATION...JP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
359 PM CST MON FEB 15 2016 .SHORT TERM...THE NEXT 3 TO 5 HOURS WILL BE THE MOST ACTIVE OF THE ENTIRE FORECAST PERIOD. CURRENT SURFACE ANALYSIS SHOWS THE LOW CENTER IN CENTRAL MISSISSIPPI EAST OF JACKSON CONTINUING TO DEEPEN WITH A PRESSURE OF NEAR 1005MB. APPENDANT COLD FRONT EXTENDS FROM THERE THROUGH HATTIESBURG AND HAMMOND...THEN BACK WEST TO JUST SOUTH OF BATON ROUGE. THUS THE MAJORITY OF THE FORECAST AREA REMAINS IN THE WARM SECTOR. BASED ON MID MORNING SOUNDING...THIS AREA IS VERY BUOYANT AND FULL OF INSTABILITY ON THE ORDER OF 1500 TO 2000 J/KG OF CAPE. MUCH HIGHER THAN MODEL SOUNDINGS SUGGESTED IN PREVIOUS DAYS. ADDITIONALLY...THE WET BULB ZERO HEIGHT WAS AROUND 9KFT WHICH IS VERY LOW AND THE MAIN REASON FOR THE WIDESPREAD HAIL THAT`S BEEN OBSERVED TODAY. THE KLIX VAD SHOWS VERY STRONG WINDS THROUGHOUT THE COLUMN...ON THE ORDER OF 50 KNOTS FROM 5KFT TO OVER 40KFT. THIS IS CREATING ENOUGH SHEAR FOR SOME STORMS TO ROTATE. LOCATIONS SOUTH OF INTERSTATE 10...ALTHOUGH IN HIGHER MOISTURE...LIKELY BEING CAPPED DUE TO COOLER GULF WATER TEMPS. THE REST OF THE AREA HAS THE POTENTIAL TO BE IMPACTED BY STRONG TO SEVERE STORMS AHEAD OF THE FRONT AND THEN ALONG THE ACTUAL BOUNDARY AS IT PROGRESSES EASTWARD. THE HRRR HAS BEEN QUITE GOOD WITH TIMING AND PROGRESSION OF THE SYSTEM TODAY...SO BASED ON THAT...SHOULD SEE THE BACK EDGE OF THE THUNDERSTORMS PUSHING OFFSHORE IN THE 01-02Z TIME FRAME. CLEARER SKIES WILL BE DELAYED BY A FEW HOURS BUT MOST OF THE CWA SHOULD BE CLOUD FREE AFTER MIDNIGHT. .LONG TERM... POST FRONTAL HIGH PRESSURE COMING FROM THE WEST TUESDAY WILL NOT HAVE MUCH IN THE WAY OF COOLER TEMPS WITH THAT AIR MASS...JUST DRY CONDITIONS. SO WILL EXPERIENCE WARMER TEMPS TUESDAY. THE TREND WILL CONTINUE THROUGHOUT THE WEEK AND INTO THE WEEKEND AS UPPER LEVEL RIDGE TRACKS FROM WEST TO EAST ACROSS THE CWA. MOST GUIDANCE DID SUGGEST COOLER TEMPS THIS MODEL RUN BUT THATS DIFFERENT FROM THE LAST SEVERAL DAYS IN A ROW...SO NOT MAKING ANY CHANGES TO THE EXTENDING FORECAST TEMPS. HIGHS WILL MODERATE INTO THE MID 70S FRIDAY ONWARD. MEFFER && .AVIATION...MOST TERMINALS TO BE IMPACTED BY RAIN AND THUNDERSTORMS OVER THE NEXT FEW HOURS. VISIBILITIES WILL DROP TO 3 MILES OR LESS WITH HEAVIER RAIN AND GUSTS UP TO 40 KNOTS POSSIBLE WITH STRONGER STORMS. CLEARING LINE SHOULD REACH THE COAST BY 02Z THIS EVENING. AREAS OF LIGHT TO MODERATE FOG WITH MVFR VIS POSSIBLE BETWEEN 06Z AND 12Z. MEFFER && .MARINE...1005MB SURFACE LOW HAS CAUSED GRADIENT WINDS TO RISE TO 15 TO 25 KNOTS. THESE STRONG SOUTHEAST WINDS WILL ABRUPTLY SHIFT TO NW AS THE COLD FRONT PUSHES THROUGH. OTHER THAN A BRIEF BURST OF WINDS RIGHT ALONG THE BOUNDARY...GRADIENT PRE-FRONTAL APPEARS STRONGER THAN POST-FRONTAL WITH MODEST COLD AIR ADVECTION. THIS SHOULD REDUCE THE WINDS TO JUST SCS LEVELS TONIGHT AND TUESDAY. WINDS AND SEAS SETTLE WEDNESDAY BEFORE SURFACE HIGH RIDGES WITH BETTER COLD AIR ADVECTION LATE THURSDAY INTO FRIDAY. MEFFER && .DECISION SUPPORT... DSS CODE....YELLOW. DEPLOYED...NONE. ACTIVATION...NONE. ACTIVITIES...RIVER FLOODING CONTINUES ON THE PEARL RIVER AND MISSISSIPPI RIVER AT RED RIVER LANDING. WATCHES AND WARNINGS IN EFFECT. DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE && .PRELIMINARY POINT TEMPS/POPS... MCB 42 71 43 71 / 10 0 0 0 BTR 45 73 47 73 / 10 0 0 0 ASD 43 71 44 70 / 10 0 0 0 MSY 50 68 50 69 / 10 0 0 0 GPT 45 67 45 69 / 20 0 0 0 PQL 42 69 45 69 / 40 10 10 0 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ532-536- 538-552-555-557-572-575-577. MS...NONE. GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538- 552-555-557-572-575-577. && $$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1142 AM CST MON FEB 15 2016 .AVIATION... THUNDERSTORMS EXTEND FROM AVOYELLES PARISH SOUTHWEST INTO JEFFERSON COUNTY IN SOUTHEAST TEXAS. THIS BROKEN LINE IS MOVING EAST. AIRCRAFT NEAR THESE STORMS WILL EXPERIENCE LIGHTNING ALONG WITH GUSTY WINDS IN AND NEAR AIRPORT TAF LOCATIONS. CONDITIONS ARE EXPECTED TO IMPROVE TOWARDS SUNSET AS A COLD FRONT PUSHES DOWN AND INTO THE REGION. CEILINGS ARE ALSO VARYING FROM 016 TO 045 BUT THIS WILL ALSO IMPROVE BEHIND THE FRONT. && .PREV DISCUSSION... /ISSUED 1020 AM CST MON FEB 15 2016/ UPDATE... TORNADO WATCH 14 HAS BEEN ISSUED UNTIL 6 PM. DISCUSSION... UPDATED TEXT PRODUCTS TO INCLUDE TOR WATCH 14. LATEST RADAR TRENDS INDICATE A BAND OF STRONG TO SVR STORMS EXTENDING FM AVOYELLES PARISH SW TO SABINE LAKE. THESE STORMS WERE DEVELOPING IN AN ENVIRONMENT CONDUCIVE FOR ROTATING STORMS...WITH 0-1 KM SRH NR 215 M2/S2...30 KT LOW LVL SHEAR AND DEEP LAYER SHEAR APPROACHING 50 KT PER 12Z KLCH SOUNDING. IN ADDITION...DECENT INSTABILITY IS IN PLACE WITH MUCAPE VALUES APPROACHING 2000 J/KG AND THIS SHOULD INCREASE ESPECIALLY ACRS ERN PORTIONS OF THE AREA AS THE BAND OF STORMS ENCOUNTERS DAYTIME HEATING. ALL SVR MODES...LARGE HAIL/DAMAGING WINDS/TORNADOES...WILL BE POSSIBLE. RECENT HRRR RUNS SEEM TO HAVE A DECENT HANDLE ON THE CONVECTION AND ITS EVOLUTION THROUGH THE AFTN SO BLENDED WITH INHERITED POPS TO ADJUST. ALSO AMENDED WX GRIDS TO REFLECT SVR POTENTIAL ACRS OUR LA ZONES THROUGH THE REMAINDER OF THE MORNING AND AFTN. FINALLY...TWEAKED HOURLY TEMPERATURES AND DEWPOINTS TO REFLECT RECENT OBS. ALSO ADJUSTED HIGH TEMPERATURES DOWN SLIGHTLY ACRS OUR NERN ZONES WHERE CLOUDS AND SHOWERS/STORMS WILL LIKELY LIMIT HEATING. 24 PREV DISCUSSION... /ISSUED 749 AM CST MON FEB 15 2016/ DISCUSSION... BASED ON LATEST SPC DISCUSSION...AND CURRENT RADAR TRENDS...HAVE ADDED SEVERE STORM WORDING TO THE FORECAST FOR TODAY FOR THE ENTIRE FORECAST AREA. THE THREAT WILL END FROM WEST TO EAST THIS AFTERNOON. PREV DISCUSSION... /ISSUED 542 AM CST MON FEB 15 2016/ DISCUSSION... SCT SHRA WITH ISO TSRA ACROSS THE REGION THIS MORNING. MVFR TO IFR CEILINGS WITH VCSH EXPECTED TO PERSIST THIS MORNING. BEST CHANCE OF TSRA WILL BE LATER THIS MORNING INTO THE EARLY AFTERNOON HOURS...KEEPING TEMPO GROUP FOR THIS FROM 16-20Z. ALSO...S TO SW WINDS EXPECTED TO PICK UP AS WELL DURING THIS TIME ~18-20KTS WITH GUSTS TO NEAR 30 KT. HIGHER GUSTS POSSIBLE WITHIN THE TSRA...AS HIGHLIGHTED WITHIN TEMPO GROUPS. AFTER 20-22Z...FRONTAL SYSTEM PASSING THRU...WITH WINDS SHIFTING TO THE WEST AND THEN NW DURING THE EVENING HOURS...WITH CLEARING SKIES AND VFR TO FOLLOW. DML PREV DISCUSSION... /ISSUED 313 AM CST MON FEB 15 2016/ DISCUSSION... SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE MOVING NORTHEAST ACROSS THE ENTIRE FORECAST AREA EARLY THIS MORNING...THANKS TO A FAST-MOVING MID-LEVEL SHORTWAVE. A COLD FRONT AND CORRESPONDING MID TO UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION RATHER QUICKLY THIS AFTERNOON. PER SPC...SOME OF THE STORMS THIS AFTERNOON COULD BE STRONG TO SEVERE...WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS...ESPECIALLY IN SOUTH CENTRAL LOUISIANA WHERE A SLIGHT RISK IS NOTED. AFTER THE RAIN ENDS THIS AFTERNOON...THE WEATHER MAPS TURNS QUIET FOR THE REMAINDER OF THE WEEK. A SECOND COLD FRONT DOES MOVE THROUGH THE REGION LATE TUESDAY...BUT IT IS EXPECTED TO BE DRY WITH LIMITED TO NO MOISTURE AVAILABLE. THE NEXT RAIN MAKER WILL BE SUNDAY AND MONDAY...WHEN THE NEXT FRONT COMES THROUGH THE REGION. THIS WEEK WILL SEE TEMPERATURES RUN ABOVE NORMAL WITH HIGHS IN THE 70S. LOWS WILL START OUT IN THE 40S TUESDAY AND WEDNESDAY MORNINGS BEFORE WARMING INTO THE 50S FOR THE REMAINDER OF THE WEEK AND WEEKEND. 15 && .PRELIMINARY POINT TEMPS/POPS... AEX 44 74 45 72 / 10 0 0 0 LCH 48 74 49 73 / 10 0 0 0 LFT 48 72 49 73 / 10 0 0 0 BPT 49 76 49 73 / 10 0 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$ AVIATION...19
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1020 AM CST MON FEB 15 2016 .UPDATE... TORNADO WATCH 14 HAS BEEN ISSUED UNTIL 6 PM. && .DISCUSSION... UPDATED TEXT PRODUCTS TO INCLUDE TOR WATCH 14. LATEST RADAR TRENDS INDICATE A BAND OF STRONG TO SVR STORMS EXTENDING FM AVOYELLES PARISH SW TO SABINE LAKE. THESE STORMS WERE DEVELOPING IN AN ENVIRONMENT CONDUCIVE FOR ROTATING STORMS...WITH 0-1 KM SRH NR 215 M2/S2...30 KT LOW LVL SHEAR AND DEEP LAYER SHEAR APPROACHING 50 KT PER 12Z KLCH SOUNDING. IN ADDITION...DECENT INSTABILITY IS IN PLACE WITH MUCAPE VALUES APPROACHING 2000 J/KG AND THIS SHOULD INCREASE ESPECIALLY ACRS ERN PORTIONS OF THE AREA AS THE BAND OF STORMS ENCOUNTERS DAYTIME HEATING. ALL SVR MODES...LARGE HAIL/DAMAGING WINDS/TORNADOES...WILL BE POSSIBLE. RECENT HRRR RUNS SEEM TO HAVE A DECENT HANDLE ON THE CONVECTION AND ITS EVOLUTION THROUGH THE AFTN SO BLENDED WITH INHERITED POPS TO ADJUST. ALSO AMENDED WX GRIDS TO REFLECT SVR POTENTIAL ACRS OUR LA ZONES THROUGH THE REMAINDER OF THE MORNING AND AFTN. FINALLY...TWEAKED HOURLY TEMPERATURES AND DEWPOINTS TO REFLECT RECENT OBS. ALSO ADJUSTED HIGH TEMPERATURES DOWN SLIGHTLY ACRS OUR NERN ZONES WHERE CLOUDS AND SHOWERS/STORMS WILL LIKELY LIMIT HEATING. 24 && .PREV DISCUSSION... /ISSUED 749 AM CST MON FEB 15 2016/ DISCUSSION... BASED ON LATEST SPC DISCUSSION...AND CURRENT RADAR TRENDS...HAVE ADDED SEVERE STORM WORDING TO THE FORECAST FOR TODAY FOR THE ENTIRE FORECAST AREA. THE THREAT WILL END FROM WEST TO EAST THIS AFTERNOON. PREV DISCUSSION... /ISSUED 542 AM CST MON FEB 15 2016/ DISCUSSION... SCT SHRA WITH ISO TSRA ACROSS THE REGION THIS MORNING. MVFR TO IFR CEILINGS WITH VCSH EXPECTED TO PERSIST THIS MORNING. BEST CHANCE OF TSRA WILL BE LATER THIS MORNING INTO THE EARLY AFTERNOON HOURS...KEEPING TEMPO GROUP FOR THIS FROM 16-20Z. ALSO...S TO SW WINDS EXPECTED TO PICK UP AS WELL DURING THIS TIME ~18-20KTS WITH GUSTS TO NEAR 30 KT. HIGHER GUSTS POSSIBLE WITHIN THE TSRA...AS HIGHLIGHTED WITHIN TEMPO GROUPS. AFTER 20-22Z...FRONTAL SYSTEM PASSING THRU...WITH WINDS SHIFTING TO THE WEST AND THEN NW DURING THE EVENING HOURS...WITH CLEARING SKIES AND VFR TO FOLLOW. DML PREV DISCUSSION... /ISSUED 313 AM CST MON FEB 15 2016/ DISCUSSION... SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE MOVING NORTHEAST ACROSS THE ENTIRE FORECAST AREA EARLY THIS MORNING...THANKS TO A FAST-MOVING MID-LEVEL SHORTWAVE. A COLD FRONT AND CORRESPONDING MID TO UPPER LEVEL SHORTWAVE WILL MOVE ACROSS THE REGION RATHER QUICKLY THIS AFTERNOON. PER SPC...SOME OF THE STORMS THIS AFTERNOON COULD BE STRONG TO SEVERE...WITH DAMAGING WINDS AND LARGE HAIL THE PRIMARY THREATS...ESPECIALLY IN SOUTH CENTRAL LOUISIANA WHERE A SLIGHT RISK IS NOTED. AFTER THE RAIN ENDS THIS AFTERNOON...THE WEATHER MAPS TURNS QUIET FOR THE REMAINDER OF THE WEEK. A SECOND COLD FRONT DOES MOVE THROUGH THE REGION LATE TUESDAY...BUT IT IS EXPECTED TO BE DRY WITH LIMITED TO NO MOISTURE AVAILABLE. THE NEXT RAIN MAKER WILL BE SUNDAY AND MONDAY...WHEN THE NEXT FRONT COMES THROUGH THE REGION. THIS WEEK WILL SEE TEMPERATURES RUN ABOVE NORMAL WITH HIGHS IN THE 70S. LOWS WILL START OUT IN THE 40S TUESDAY AND WEDNESDAY MORNINGS BEFORE WARMING INTO THE 50S FOR THE REMAINDER OF THE WEEK AND WEEKEND. 15 && .PRELIMINARY POINT TEMPS/POPS... AEX 66 44 74 45 / 80 10 0 0 LCH 72 48 74 49 / 70 10 0 0 LFT 72 48 72 49 / 90 10 0 0 BPT 74 49 76 49 / 60 10 0 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...NONE. TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 406 PM EST MON FEB 15 2016 WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE ALONG THE W COAST OF THE CONUS/CANADA AND A DOWNSTREAM TROF OVER CNTRL/ERN N AMERICA WITH AXIS GENERALLY FROM THE WRN GREAT LAKES TO THE LWR MISSISSIPPI VALLEY. SHORTWAVE TROF THAT BROUGHT SOME -SN TO THE AREA LAST NIGHT/THIS MORNING HAS SHIFTED E OF THE AREA. KGRB RADAR AND SFC OBS/WEBCAMS SHOWED A BAND OF LAKE ENHANCED SNOW ALONG SFC TROF THAT MOVED OUT ACROSS LAKE MI LATE LAST NIGHT/THIS MORNING. AT LEAST AT LOCATIONS WITH WEBCAMS...IT DID NOT APPEAR THAT THERE WAS MORE THAN 2-3 INCHES OF SNOW WITH THE LAKE ENHANCEMENT...BUT THERE CERTAINLY COULD HAVE BEEN SOME ISOLATED HIGHER AMOUNTS. SOME -SN STILL LINGERS IN THE VCNTY OF THE WEAKENING TROF WHICH IS NOW INTO LUCE COUNTY. TO THE W...THERE HAVE BEEN SCT FLURRIES...BUT LATEST KMQT RADAR SUGGESTS THE FLURRIES HAVE MOSTLY DISSIPATED. UPSTREAM...NEXT SHORTWAVE OF INTEREST IS IN NRN MANITOBA/NRN SASKATCHEWAN. A GENERALLY QUIET EVENING IS EXPECTED. LINGERING -SN OVER THE FAR E WILL END THIS EVENING AS SFC TROF DRIFTS E AND WINDS BECOME WSW ACROSS NRN LAKE MI. THERE MAY BE A FEW FLURRIES ELSEWHERE... ESPECIALLY IF SMALL AREA OF -SHSN/FLURRIES OVER NE MN HOLDS TOGETHER. OVERNIGHT...AS SHORTWAVE IN MANITOBA/SASKATCHEWAN DROPS SE...THERE IS AN INCREASE IN MOISTURE DEPTH AND DEEP LAYER FORCING PER QVECTORS INTO THE WRN FCST AREA. WITH MOST MODELS GENERATING SOME PCPN...GRADUALLY INCREASED POPS THRU THE CHC CATEGORY OVER THE W OVERNIGHT. AS FOR TEMPS...WHILE CLOUDS SHOULD PERSIST ACROSS THE BOARD TONIGHT AND HOLD TEMPS UP...THERE IS SOME CONCERN THAT CLOUDS COULD BREAK FOR A TIME OVER PORTIONS OF THE CNTRL AND ERN FCST AREA WHERE LIGHT DOWNSLOPING OCCURS. THE BIAS CORRECTED REGIONAL AND GLOBAL CANADIAN MODELS WHICH ARE OFTEN SUPERIOR PERFORMERS WITH RADIATIONAL COOLING INDICATE MIN TEMPS DOWN INTO THE LWR SINGLE DIGITS FROM PARTS OF MENOMINEE COUNTY EASTWARD...WITH SOME TEMPS SUB ZERO TEMPS IN SCHOOLCRAFT COUNTY. FOR NOW...LOWERED TEMPS SLIGHTLY DOWN TOWARD 10F OVER PORTIONS OF THE ERN FCST AREA. ON TUE...AFOREMENTIONED SHORTWAVE SWINGS INTO THE UPPER GREAT LAKES WITH ASSOCIATED COLD FRONT REACHING THE KEWEENAW LATE MORNING/EARLY AFTN AND EXITING THE SE FCST AREA LATE AFTN/EARLY EVENING. BAND OF DEEP LAYER FORCING/DEEP MOISTURE WHICH BEGINS TO ARRIVE OVER THE W LATE TONIGHT SHIFTS ACROSS THE FCST AREA ON TUE. AS A RESULT...MOST AREAS SHOULD SEE SOME -SN AT SOME POINT TUE. UTILIZED CHC POPS. EXPECT A BURST OF HEAVIER SNOW TO ACCOMPANY COLD FRONT AS IT DROPS SSE ACROSS LAKE SUPERIOR AND INTO UPPER MI AS 850MB TEMPS ARE JUST COLD ENOUGH TO SUPPORT LAKE ENHANCEMENT. AS A RESULT...INCLUDED A SHORT PERIOD OF LIKELY POPS ALONG THE COLD FRONT AND INTO WRN/NRN UPPER MI WITH SNOW ACCUMULATIONS OF 1-2 INCHES NEAR THE LAKE. ELSEWHERE...ANY SNOW ACCUMULATION WILL BE UNDER 1 INCH. PATCHY BLSN SHOULD DEVELOP CLOSE TO THE LAKE FROM THE KEWEENAW EASTWARD AFTER FROPA. WITH AN OPPORTUNITY TO WARM UP PRIOR TO FROPA...TEMPS SHOULD TOP OUT AROUND 30F ACROSS THE FCST AREA. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 314 PM EST MON FEB 15 2016 A 500MB TROUGH WILL BE SET UP ACROSS MUCH OF THE E THIRD OF THE NATION THROUGH WEDNESDAY. EXPECT ANOTHER BLAST OF COLD AIR TO SWING IN ON N WINDS TUESDAY NIGHT/WEDNESDAY...WITH 850MB TEMPS AVERAGING -16C. ACCOMPANYING THIS COLD AIR WILL BE ANOTHER SHORTWAVE TUESDAY NIGHT...AND INCREASED NNW WINDS...WHICH WILL COMBINE TO HELP CREATE SNOW AND BLOWING SNOW OVER THE KEWEENAW PENINSULA THROUGH WHITEFISH POINT. WILL CONTINUE TO MENTION THE POTENTIAL FOR LIGHT-MODERATE SNOW AND BLOWING SNOW IN THE HWO BEFORE WINDS DIMINISH W-E WEDNESDAY MORNING AS THE SFC HIGH SHIFTS OVERHEAD. HIGHS WEDNESDAY WILL STRUGGLE TO GET OUT OF THE TEENS. LOOK FOR THE 500MB RIDGE CURRENTLY PUSHING INTO THE W SEABOARD TO SHIFT E...AND BE CENTERED ACROSS THE PLAINS STATES THURSDAY MORNING. IT WILL BE A RACE TO SEE HOW LOW TEMPERATURES CAN FALL BEFORE HIGH CLOUDS NEAR FROM THE NW AND WAA TAKES COLD ON INCREASED S-SW WINDS THURSDAY MORNING AS 850MB TEMPS WARM TO AROUND -8C BY DAYBREAK THURSDAY. SINGLE DIGIT LOWS STILL LOOK REASONABLE. THE WAA WILL ALSO PUT AN END TO THE LES OFF E LAKE SUPERIOR EARLY WEDNESDAY EVENING. THE 500MB RIDGE WILL SWIFTLY SLIDE OVER THE GREAT LAKES REGION THURSDAY AFTERNOON/THURSDAY EVENING. LOOK FOR A TEMPORARY BREAK FROM THE SNOW...ALTHOUGH WAA SNOW MAY RETURN WITH THE PASSAGE OF THE WARM FRONT THURSDAY EVENING. MIXED PRECIP WILL BE A CONCERN. BY 00Z FRIDAY 850MB WINDS OUT OF THE S AT 40-55KT WILL HELP USHER 850MB TEMPS OF -3 TO +3C OVER THE CWA. THERE ARE ENOUGH DIFFERENCES IN THE FCST MODELS AT THIS DISTANCE TO GIVE MODERATE TO LOW CONFIDENCE IN SPECIFIC PRECIP TYPES...ALTHOUGH SNOW...FREEZING RAIN...AND RAIN WILL ALL BE POSSIBLE AT SOME POINT THURSDAY NIGHT INTO FRIDAY MORNING. WILL KEEP THE MENTION OF A WINTRY MIX OF PRECIP IN THE HWO. THAT WILL BE UNTIL SFC TEMPS WARM UP ENOUGH FOR MOST OF THE PRECIP TO FALL IN THE FORM OF RAIN. THE 00Z ECMWF AND 06Z GFS WERE FAIRLY IN LINE WITH SLIDING THE NEARING SFC LOW OVER MN EARLY FRIDAY MORNING...CROSSING UPPER MI/N LAKE MI DURING THE DAY...AND EXITING ACROSS LAKE HURON FRIDAY EVENING. THE 06Z CANADIAN MODEL WAS MUCH FARTHER TO THE N WITH THE LOW...WHICH WAS BACKED BY THE ECMWF YESTERDAY. OVERALL...THE GFS HAS BEEN MORE CONSISTENT OVERALL WITH THE TRACK. THE 12Z SOLUTIONS ARE COMING IN WITH AT LEAST SOME BETTER AGREEMENT ON THE TRACK OF THE LOW NEAR LAKE SUPERIOR FRIDAY AFTERNOON-EVENING...BUT STILL PLENTY OF TIME FOR CHANGES. COLDER AIR WILL FILTER IN BEHIND THE EXITING SFC LOW FRIDAY NIGHT. JUST HOW COLD IS ANOTHER QUESTION...AS THE GFS AND ECMWF VARY BY AROUND 5C...RANGING FROM -9C TO -2C /COLDEST OFF THE ECMWF/ BY 12Z SATURDAY. THIS COULD MAKE THE DIFFERENCE IN ALL SNOW OR LINGERING RAIN/SNOW MIX INLAND SATURDAY MORNING. W-NW WINDS WILL BE THE RULE FROM 00Z SATURDAY-00Z SUNDAY. WILL RUN WITH A BLENDED MODEL SOLUTION FOR SATURDAY NIGHT THROUGH NEXT MONDAY...AS THE NEXT 500MB TROUGH DIVES IN. THE SMALL SCALE DIFFERENCES ARE GOING TO BE DIFFICULT TO PERFECT AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1233 PM EST MON FEB 15 2016 MVFR CIGS WILL LIKELY CONTINUE AT KIWD THRU THE AFTN GIVEN THE LOW CLOUDS UPSTREAM ACROSS NW WI/MN. AT KCMX...EXPECT VFR CIGS TO FALL TO MVFR THIS AFTN AS LOWER CLOUDS TO THE W AND SW SPREAD INTO THE AREA. SIMILAR SITUATION SHOULD OCCUR AT KSAW...BUT LATER IN THE AFTN/EARLY EVENING. FCST FOR TONIGHT WILL BE CHALLENGING AS LARGER SCALE SUBSIDENCE/LOWERING INVERSION IN THE PRESENCE OF NOCTURNAL COOLING MAY BRING ABOUT IFR CIGS. FOR NOW...LOWERED CIGS TO LOW MVFR WITH IFR DEVELOPING LATE OVERNIGHT/EARLY MORNING AT KIWD/KCMX... PARTLY IN RESPONSE TO SOME -SN SPREADING INTO THE AREA. && .MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT 406 PM EST MON FEB 15 2016 WITH A WEAKENING PRES GRADIENT OVER THE UPPER LAKES...WINDS ACROSS LAKE SUPERIOR WILL DIMINISH TO UNDER 20KT TONIGHT INTO TUE MORNING. PASSAGE OF A COLD FRONT ON TUE AND TIGHTENING PRES GRADIENT AHEAD OF HIGH PRES BUILDING INTO MANITOBA WILL BRING A PERIOD OF STRONGER N WINDS UP TO 30KT TUE AFTN/NIGHT...WITH THE STRONGEST WINDS OVER THE CNTRL AND ERN PORTIONS OF LAKE SUPERIOR LATE TUE AFTN/EVENING. THERE MAY BE A FEW GALE FORCE GUSTS. IN ADDITION...EXPECT SOME HEAVY FREEZING SPRAY TO DEVELOP OVER PORTIONS OF CENTRAL LAKE SUPERIOR. WINDS WILL DIMINISH TO UNDER 20KT WED AS HIGH PRES ARRIVES OVER THE UPPER LAKES. STRONGER SSE WINDS UP TO 30KT WILL THEN DEVELOP ON THU UNDER A TIGHTENING PRES GRADIENT BETWEEN THE DEPARTING HIGH AND ANOTHER APPROACHING LOW PRES. WINDS MAY INCREASE FURTHER TO GALES THU NIGHT OVER THE E HALF OF LAKE SUPERIOR. THE LOW WILL PASS OVER OR JUST N OF LAKE SUPERIOR FRI. STRONG W TO NW WINDS UP TO 30KT WILL THEN FOLLOW INTO FRI NIGHT AND SAT. && .MQT WATCHES/WARNINGS/ADVISORIES... UPPER MICHIGAN... NONE. LAKE SUPERIOR... NONE. LAKE MICHIGAN... NONE. && $$ SHORT TERM...ROLFSON LONG TERM...KF AVIATION...ROLFSON MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1243 PM EST MON FEB 15 2016 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 328 AM EST MON FEB 15 2016 SEVERAL WEAK LOW PRESSURE SYSTEMS WILL TAKE AIM AT THE GREAT LAKES...BUT MOSTLY MISS. THE ONGOING LIGHT SNOW OVER LOWER MICHIGAN WILL DIMINISH TODAY. ANOTHER LOW WILL PASS MOSTLY SOUTH OF LOWER MICHIGAN TUESDAY. MUCH WARMER AIR IS A STRONG POSSIBILITY FRIDAY AHEAD OF A LOW MOVING ACROSS THE UP. WE MAY END UP SEEING RAIN WITH THAT SYSTEM. && .UPDATE... ISSUED AT 1157 AM EST MON FEB 15 2016 SYSTEM SNOW IS STARTING TO PIVOT OUT OF THE FORECAST AREA AS WE APPROACH NOON...BUT THERE IS A FINAL BURST MOVING THROUGH CENTRAL LOWER MI. THE SNOW IS ASSOCIATED WITH A MID LEVEL SHORTWAVE TROUGH THAT WILL MOVE EAST OF THE AREA THROUGH THE COURSE OF THE AFTERNOON AND EARLY EVENING HOURS. ANY ADDITIONAL ACCUMULATION TODAY WILL BE LESS THAN AN INCH. AS THE MID LEVEL MOISTURE PULLS AWAY AND THERE IS A BIT OF LIFT LEFT IN THE PROFILE WE MAY CONTINUE TO SEE PATCHY FREEZING DRIZZLE. CURRENT THINKING IS THAT THIS THREAT IS PRETTY MINIMAL AND ITS OCCURRENCE SHOULD BE WAINING. FINAL ITEM OF NOTE IS A BAND OF LAKE EFFECT SNOW OUT OVER LAKE MICHIGAN. IT IS NOT WELL SEEN AND WE ARE LIKELY OVERSHOOTING IT FROM THE KGRR RADAR. MULTIPLE RUNS OF THE HRRR HAVE SHOWN THIS BAND COMING ASHORE BETWEEN 18Z-21Z ACROSS WEST CENTRAL LOWER MI. THE FLOW BEHIND THE SHORTWAVE WILL SHIFT TO THE SOUTHWEST WHICH WILL BRING THE BAND ON SHORE. THERE WILL BE A LOCAL BURST TO THE SNOW AND VISIBILITY WILL BE AFFECTED. COULD SEE A LOCAL INCH OR SO FROM THIS BAND BEFORE IT MOVES INLAND AND DISSIPATES AFTER 20Z-21Z. PLENTY OF CLOUDS HANG ON TODAY WITH TEMPERATURES RELEGATED TO THE 20S FOR HIGHS. UPDATE ISSUED AT 759 AM EST MON FEB 15 2016 HAVE ISSUED AN UPDATE TO INCLUDE A CHANCE OF FREEZING DRIZZLE MAINLY ALONG AND SOUTH I-96. THIS IS BASED ON THE RECENT ARRIVAL OF LOWER CEILINGS OF 500-900 FT AND 3-5 MILE VISIBILITIES IN MIST NOW SHOWING UP IN THE OBSERVATIONS... AS WELL AS SOME RECENT REPORTS. WOULD NOT EXPECT TOO MUCH IMPACT HOWEVER SINCE IT WILL BE FALLING ON TOP OF A FRESH COATING OF LIGHT SNOW. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 328 AM EST MON FEB 15 2016 FORECAST CONCERNS DEAL WITH THE ONGOING LIGHT SNOW TODAY AND CHANCES FOR LIGHT SHOW TUESDAY NIGHT. SNOWFALL HAS BEEN PRETTY UNDERWHELMING SO FAR...BUT IN LINE WITH EXPECTATIONS. RADAR SHOWS A CHAOTIC ECHO PATTERN BUT HAS BEEN FILLING IN DURING THE PAST HOUR OR SO. SHORT RANGE MODELS INDICATE THIS SNOW CONTINUE THIS MORNING AND DIMINISH THIS AFTERNOON. ALTHOUGH THE SFC LOW IS MOVING AWAY...THE UPPER TROUGH WILL BE SWINGING THROUGH THIS AFTERNOON AND TONIGHT. THE SNOW SHOULD FINALLY END AROUND MIDNIGHT TONIGHT WHEN THE UPPER TROUGH AXIS PIVOTS THROUGH THE CWA. WEAK LOW PRESSURE WILL MOVE ACROSS THE UPPER MISSISSIPPI VALLEY LATE TUESDAY AND TUESDAY NIGHT WITH SOME SUPPORT ALOFT. THIS SYSTEM WON/T AMOUNT TO MUCH EITHER BUT SOME LIGHT SNOW IS POSSIBLE MAINLY TUESDAY AFTERNOON INTO TUESDAY NIGHT. THE UPPER TROUGH CLEARS LOWER MICHIGAN WEDNESDAY AND WE/LL SEE IMPROVING CONDITIONS THEN. HIGH TEMPS WILL REMAIN BELOW AVERAGE THROUGH WEDNESDAY. UPPER 20S ARE EXPECTED TODAY...MID 30S TUESDAY AND AROUND 30 WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 328 AM EST MON FEB 15 2016 TURNING WARMER IS THE MAIN MESSAGE FOR THE LONG TERM PERIOD AS THE UPPER FLOW PATTERN GOES ZONAL AND A PACIFIC STORM TRACKS ACROSS THE NORTHERN UNITED STATES. WEDNESDAY NIGHT LOOKS TO BE A COLD ONE WITH A SFC HIGH DIRECTLY OVERHEAD AND CLEAR SKIES. LOWS 5 TO 15 ABOVE ALTHOUGH SOME ISOLATED SUB ZERO READINGS ARE POSSIBLE. INCREASING CLOUDS EXPECTED ON THURSDAY AS THE PACIFIC SYSTEM MOVES INTO THE NRN PLAINS AND WARM ADVECTION CLOUDS THICKEN AHEAD OF A WARM FRONT APPROACHING FROM THE SOUTHWEST. THIS FRONT COULD BRING US A BRIEF PERIOD OF LIGHT FREEZING RAIN/SLEET/SNOW ON THURSDAY NIGHT BUT ANY PRECIPITATION SHOULD CHANGE QUICKLY TO RAIN EARLY FRIDAY MORNING AS A 50-60 KT LOW LEVEL JET USHERS IN RAPID WARMING FROM THE SOUTHWEST. GUIDANCE TEMPS CONTINUE TO TREND UP FOR FRIDAY WHEN WE WILL BE IN THE WARM SECTOR OF THE SFC CYCLONE TRACKING ACROSS NORTHERN MICHIGAN. HIGHS COULD EXCEED 50 DEGREES NEAR AND SOUTH OF I-96 ALTHOUGH IT WILL BE RATHER BREEZY. COOLING OFF A TAD NEXT WEEKEND BEHIND THE DEPARTING LOW... BUT NO ARCTIC AIR BEHIND IT AND HIGHS SHOULD BE AT LEAST 5-10 DEGREES ABOVE NORMAL SAT AND SUN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1243 PM EST MON FEB 15 2016 A MIX OF IFR AND MVFR CONDITIONS WERE PRESENT OVER THE REGION AS OF 1730Z. MOST OF THE MVFR WAS ACROSS THE I-96 AREA...WITH WIDESPREAD IFR ACROSS I-94. WITH A DECREASE IN MIXING THROUGH THE AFTERNOON AND TONIGHT EXPECT CONDITIONS TO CHANGE VERY LITTLE. FAIRLY HIGH CONFIDENCE THAT THE I-94 TAF SITES WILL REMAIN IFR...WITH PERHAPS SOME IMPROVE LATE TONIGHT/EARLY TUESDAY MORNING AS DRIER AIR ARRIVES. THE I-96 TAF SITES ARE MORE CHALLENGING AS THEY COULD TREND EITHER WAY...HIGHER OR LOWER. FOR NOW HAVE TRENDED THESE TAFS UP TO MORE MVFR THROUGH THE AFTERNOON. BUT THERE IS DECENT CHANCES THESE SITES TREND BACK DOWN AFTER NIGHTFALL. BY EARLY TUESDAY MORNING THESE SITES TOO SHOULD TREND BACK UP INTO MVFR. && .MARINE... ISSUED AT 328 AM EST MON FEB 15 2016 OFFSHORE WINDS 10 TO 20 KNOTS WILL RESULT IN 2-4 FOOT WAVES TODAY. && .HYDROLOGY... ISSUED AT 329 PM EST SUN FEB 14 2016 NO SIGNIFICANT FLOODING IS EXPECTED THIS WEEK. RIVERS ACROSS SOUTHWEST LOWER MICHIGAN ARE LARGELY STABLE...ALTHOUGH WE WILL NEED TO CONTINUE TO MONITOR RIVER LEVELS FOR RAPID FLUCTUATIONS DUE TO ICE JAMMING. ICE FORMATION AND JAMMING IS STILL A CONCERN GIVEN THE COLD TEMPERATURES. LOWS WILL BE IN THE TEENS TONIGHT...BUT HIGHS ON MONDAY WILL BE IN THE LOW TO MID 30S...WHICH SHOULD HALT ICE FORMATION. WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO THURSDAY...TEMPS WILL BE WARMER THIS WEEK...TOO WARM FOR ICE TO THICKEN. RIVERS SHOULD GENERALLY BE ABLE TO FLOW FREELY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...DUKE SYNOPSIS...04 SHORT TERM...04 LONG TERM...MEADE AVIATION...JK HYDROLOGY...EBW MARINE...04
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1157 AM EST MON FEB 15 2016 LATEST UPDATE... UPDATE .SYNOPSIS... ISSUED AT 328 AM EST MON FEB 15 2016 SEVERAL WEAK LOW PRESSURE SYSTEMS WILL TAKE AIM AT THE GREAT LAKES...BUT MOSTLY MISS. THE ONGOING LIGHT SNOW OVER LOWER MICHIGAN WILL DIMINISH TODAY. ANOTHER LOW WILL PASS MOSTLY SOUTH OF LOWER MICHIGAN TUESDAY. MUCH WARMER AIR IS A STRONG POSSIBILITY FRIDAY AHEAD OF A LOW MOVING ACROSS THE UP. WE MAY END UP SEEING RAIN WITH THAT SYSTEM. && .UPDATE... ISSUED AT 1157 AM EST MON FEB 15 2016 SYSTEM SNOW IS STARTING TO PIVOT OUT OF THE FORECAST AREA AS WE APPROACH NOON...BUT THERE IS A FINAL BURST MOVING THROUGH CENTRAL LOWER MI. THE SNOW IS ASSOCIATED WITH A MID LEVEL SHORTWAVE TROUGH THAT WILL MOVE EAST OF THE AREA THROUGH THE COURSE OF THE AFTERNOON AND EARLY EVENING HOURS. ANY ADDITIONAL ACCUMULATION TODAY WILL BE LESS THAN AN INCH. AS THE MID LEVEL MOISTURE PULLS AWAY AND THERE IS A BIT OF LIFT LEFT IN THE PROFILE WE MAY CONTINUE TO SEE PATCHY FREEZING DRIZZLE. CURRENT THINKING IS THAT THIS THREAT IS PRETTY MINIMAL AND ITS OCCURRENCE SHOULD BE WAINING. FINAL ITEM OF NOTE IS A BAND OF LAKE EFFECT SNOW OUT OVER LAKE MICHIGAN. IT IS NOT WELL SEEN AND WE ARE LIKELY OVERSHOOTING IT FROM THE KGRR RADAR. MULTIPLE RUNS OF THE HRRR HAVE SHOWN THIS BAND COMING ASHORE BETWEEN 18Z-21Z ACROSS WEST CENTRAL LOWER MI. THE FLOW BEHIND THE SHORTWAVE WILL SHIFT TO THE SOUTHWEST WHICH WILL BRING THE BAND ON SHORE. THERE WILL BE A LOCAL BURST TO THE SNOW AND VISIBILITY WILL BE AFFECTED. COULD SEE A LOCAL INCH OR SO FROM THIS BAND BEFORE IT MOVES INLAND AND DISSIPATES AFTER 20Z-21Z. PLENTY OF CLOUDS HANG ON TODAY WITH TEMPERATURES RELEGATED TO THE 20S FOR HIGHS. UPDATE ISSUED AT 759 AM EST MON FEB 15 2016 HAVE ISSUED AN UPDATE TO INCLUDE A CHANCE OF FREEZING DRIZZLE MAINLY ALONG AND SOUTH I-96. THIS IS BASED ON THE RECENT ARRIVAL OF LOWER CEILINGS OF 500-900 FT AND 3-5 MILE VISIBILITIES IN MIST NOW SHOWING UP IN THE OBSERVATIONS... AS WELL AS SOME RECENT REPORTS. WOULD NOT EXPECT TOO MUCH IMPACT HOWEVER SINCE IT WILL BE FALLING ON TOP OF A FRESH COATING OF LIGHT SNOW. && .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 328 AM EST MON FEB 15 2016 FORECAST CONCERNS DEAL WITH THE ONGOING LIGHT SNOW TODAY AND CHANCES FOR LIGHT SHOW TUESDAY NIGHT. SNOWFALL HAS BEEN PRETTY UNDERWHELMING SO FAR...BUT IN LINE WITH EXPECTATIONS. RADAR SHOWS A CHAOTIC ECHO PATTERN BUT HAS BEEN FILLING IN DURING THE PAST HOUR OR SO. SHORT RANGE MODELS INDICATE THIS SNOW CONTINUE THIS MORNING AND DIMINISH THIS AFTERNOON. ALTHOUGH THE SFC LOW IS MOVING AWAY...THE UPPER TROUGH WILL BE SWINGING THROUGH THIS AFTERNOON AND TONIGHT. THE SNOW SHOULD FINALLY END AROUND MIDNIGHT TONIGHT WHEN THE UPPER TROUGH AXIS PIVOTS THROUGH THE CWA. WEAK LOW PRESSURE WILL MOVE ACROSS THE UPPER MISSISSIPPI VALLEY LATE TUESDAY AND TUESDAY NIGHT WITH SOME SUPPORT ALOFT. THIS SYSTEM WON/T AMOUNT TO MUCH EITHER BUT SOME LIGHT SNOW IS POSSIBLE MAINLY TUESDAY AFTERNOON INTO TUESDAY NIGHT. THE UPPER TROUGH CLEARS LOWER MICHIGAN WEDNESDAY AND WE/LL SEE IMPROVING CONDITIONS THEN. HIGH TEMPS WILL REMAIN BELOW AVERAGE THROUGH WEDNESDAY. UPPER 20S ARE EXPECTED TODAY...MID 30S TUESDAY AND AROUND 30 WEDNESDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 328 AM EST MON FEB 15 2016 TURNING WARMER IS THE MAIN MESSAGE FOR THE LONG TERM PERIOD AS THE UPPER FLOW PATTERN GOES ZONAL AND A PACIFIC STORM TRACKS ACROSS THE NORTHERN UNITED STATES. WEDNESDAY NIGHT LOOKS TO BE A COLD ONE WITH A SFC HIGH DIRECTLY OVERHEAD AND CLEAR SKIES. LOWS 5 TO 15 ABOVE ALTHOUGH SOME ISOLATED SUB ZERO READINGS ARE POSSIBLE. INCREASING CLOUDS EXPECTED ON THURSDAY AS THE PACIFIC SYSTEM MOVES INTO THE NRN PLAINS AND WARM ADVECTION CLOUDS THICKEN AHEAD OF A WARM FRONT APPROACHING FROM THE SOUTHWEST. THIS FRONT COULD BRING US A BRIEF PERIOD OF LIGHT FREEZING RAIN/SLEET/SNOW ON THURSDAY NIGHT BUT ANY PRECIPITATION SHOULD CHANGE QUICKLY TO RAIN EARLY FRIDAY MORNING AS A 50-60 KT LOW LEVEL JET USHERS IN RAPID WARMING FROM THE SOUTHWEST. GUIDANCE TEMPS CONTINUE TO TREND UP FOR FRIDAY WHEN WE WILL BE IN THE WARM SECTOR OF THE SFC CYCLONE TRACKING ACROSS NORTHERN MICHIGAN. HIGHS COULD EXCEED 50 DEGREES NEAR AND SOUTH OF I-96 ALTHOUGH IT WILL BE RATHER BREEZY. COOLING OFF A TAD NEXT WEEKEND BEHIND THE DEPARTING LOW... BUT NO ARCTIC AIR BEHIND IT AND HIGHS SHOULD BE AT LEAST 5-10 DEGREES ABOVE NORMAL SAT AND SUN. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 655 AM EST MON FEB 15 2016 PREDOMINATELY MVFR CONDITIONS EXPECTED TODAY WITH OCCASIONAL LIGHT SNOW ALTHOUGH SOME SPOTTY IFR POSSIBLE AS BANDS OF HEAVIER SNOW PIVOT THROUGH THIS MORNING. MVFR CONTINUING TONIGHT WITH A POSSIBILITY OF IFR BECOMING MORE WIDESPREAD AFTER 06Z AS CIGS LOWER SOME. && .MARINE... ISSUED AT 328 AM EST MON FEB 15 2016 OFFSHORE WINDS 10 TO 20 KNOTS WILL RESULT IN 2-4 FOOT WAVES TODAY. && .HYDROLOGY... ISSUED AT 329 PM EST SUN FEB 14 2016 NO SIGNIFICANT FLOODING IS EXPECTED THIS WEEK. RIVERS ACROSS SOUTHWEST LOWER MICHIGAN ARE LARGELY STABLE...ALTHOUGH WE WILL NEED TO CONTINUE TO MONITOR RIVER LEVELS FOR RAPID FLUCTUATIONS DUE TO ICE JAMMING. ICE FORMATION AND JAMMING IS STILL A CONCERN GIVEN THE COLD TEMPERATURES. LOWS WILL BE IN THE TEENS TONIGHT...BUT HIGHS ON MONDAY WILL BE IN THE LOW TO MID 30S...WHICH SHOULD HALT ICE FORMATION. WITH THE EXCEPTION OF WEDNESDAY NIGHT INTO THURSDAY...TEMPS WILL BE WARMER THIS WEEK...TOO WARM FOR ICE TO THICKEN. RIVERS SHOULD GENERALLY BE ABLE TO FLOW FREELY. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ UPDATE...DUKE SYNOPSIS...04 SHORT TERM...04 LONG TERM...MEADE AVIATION...MEADE HYDROLOGY...EBW MARINE...04
AREA FORECAST DISCUSSION
NWS BILLINGS MT
325 PM MST MON FEB 15 2016 .SHORT TERM...VALID FOR TUE AND WED... STRONG NORTHWEST FLOW OVER THE AREA WITH A MODERATELY STRONG SHORTWAVE WORKING ACROSS THE FORECAST AREA. THIS WAVE WAS GENERATING NUMEROUS SHOWERS OVER CENTRAL ZONES. STRONG DOWNSLOPE FLOW WAS LIMITING SHOWER COVERAGE OVER WESTERN ZONES. ASCENT FROM THE SHORTWAVE WAS KEEPING THE STRONGEST WINDS OF THE DAY ALOFT. VAD WIND PROFILER WAS SHOWING 45KTS JUST FOUR THOUSAND FEET OFF THE SURFACE. STRONGEST WIND GUST AT BILLINGS HAS BEEN 53MPH AND THIS AIDED BY A FEW SHOWERS. STRONGEST SURFACE PRESSURE RISES WERE NOW MOVING INTO NORTHERN MONTANA AND PROGGED TO SLIDE ACROSS THE FORECAST AREA DURING THE EARLY EVENING. 700MB WINDS WEAKEN A BIT WITH THE STRONGEST PRESSURE RISES...BUT ASCENT WILL BE REPLACED BY SUBSIDENCE. CONFIDENCE NOT TERRIBLY HIGH THAT WARNING LEVEL WINDS WILL BE MET EARLY THIS EVENING...BUT ENOUGH THERE TO KEEP THE HIGHLIGHT GOING. LIVINGSTON HAS REMAINED BELOW ADVISORY CRITERIA THROUGH THE DAY AND SURFACE WINDS HAVE TURNED TO THE WEST. RAP SOUNDINGS SHOW WINDS DECREASING ALOFT OVER THE WEST WITH SURFACE PRESSURE GRADIENT RELAXING. STRONGEST SURFACE PRESSURE RISES WILL SLIDE EAST OF LIVINGSTON EARLY THIS EVENING. THE LACK OF GAP FLOW WOULD LEAD TO A LESS THAN IDEAL SITUATION FOR ADVISORY LEVEL WINDS. GUIDANCE WINDS HAVE THE TREND FOR DECREASING SURFACE WINDS THE REST OF THE AFTERNOON AND EARLY THIS EVENING. THE SURFACE PRESSURE GRADIENT RELAXES QUITE A BIT THIS EVENING...BUT RELOADS AGAIN TUESDAY MORNING. GUIDANCE INDICATED THE POSSIBILITY OF HITTING CRITERIA TUESDAY MORNING. WILL KEEP THE GRAPHIC OUT AND MENTION OF IT IN THE HWO FOR THE MORNING HOURS...BUT WILL LET THE EVENING AND MIDNIGHT CREWS GET A CLOSER LOOK ON POSSIBLY ISSUING ANOTHER HIGHLIGHT FOR THIS. SNOW HAS BEEN STEADY IN THE BIGHORNS THIS AFTERNOON. SNOTELS VARY IN ACCUMULATION...BUT THE CONSENSUS OF 4-6 INCHES SEEMS TO BE ABOUT THE MEDIUM SNOW RANGE. MODELS...INCLUDING HIGH RESOLUTION...ALL TAPER THE SNOW OFF THROUGH THE EVENING. WOULD EXPECT ANOTHER 2-4 INCHES THE REST OF THE AFTERNOON AND THIS EVENING. WILL KEEP THE ADVISORY GOING. MEAN UPPER RIDGE REMAINS TO THE WEST OF MONTANA FOR TUESDAY. ATMOSPHERE LOOKS UNSTABLE ONCE AGAIN BUT MID LEVEL WINDS WERE WEAKER. 700MB WINDS WERE AROUND 45KTS AND NOT LINKED UP TOTALLY WITH LOWER LEVEL WINDS. DOWNWARD MOTION SHOULD BE WEAKER TOO WITH MUCH WEAKER SURFACE PRESSURE RISES. WINDS SHOULD MATERIALIZE...BUT NOT EXPECTING WINDS AT LEVELS OF TODAY OR THIS WEEKEND. WILL OPT TO NOT ISSUE A HIGHLIGHT...AND DUE TO THE BELIEF THAT THIS WILL NOT BE A HIGHLIGHT WORTHY EVENT...WILL REMOVE MENTION FROM THE HWO FOR THE PLAINS. SHOULD BE A WINDY DAY...BUT NOT EXPECTING ANYTHING MORE THAN THAT. DID TAKE A FEW DEGREES OFF FORECAST HIGHS FOR TUESDAY. MIX DOWNS WOULD HAVE HIGHS TOPPING OUT IN THE UPPER 50S. GFS PLACES A SWATH OF MID LEVEL WARM ADVECTION PRECIPITATION OVER CENTRAL ZONES LATE TONIGHT AND EARLY TUESDAY. MODEL CONSENSUS LEADS TO MORE CONFIDENCE OF THIS POSSIBILITY...SO RAISED POPS TO SCATTERED. TEMPERATURES REMAIN MILD IN DOWNSLOPE FLOW...SO A MIX OF RAIN AND SNOW LOOKS TO BE THE EVENT...WITH LIMITED IMPACT. WEDNESDAY LOOKS DRIER AS A FLAT RIDGE SLIDES INTO THE FORECAST AREA. TWH .LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON... A PACIFIC TROUGH IS PROGGED TO APPROACH THE REGION ON THURSDAY. THIS FEATURE SHOULD SPREAD SHOWERS AHEAD OF IT THU AFTERNOON- EVENING. IT SHOULD ALSO DROP SURFACE PRESSURES EAST OF THE MOUNTAINS...SETTING UP A DECENT PRESSURE GRADIENT FOR THU AFTERNOON INTO FRI. GFS SHOWING 3-HOUR SFC PRESSURE RISES OF AROUND 6 MB AROUND 00Z FRI. THUS EXPECT ANOTHER WINDY PERIOD FOR THU AFTERNOON-FRI...WITH POSSIBLY WINDIEST PERIOD LATE THU AFTERNOON- EVENING. DRY WX EXPECTED FOR MOST OF THE AREA FRI-SUN AS UPPER-LEVEL RIDGING DOMINATES REGIONAL WEATHER. A WEAK SHORTWAVE TRACKING NEAR OUR NORTHWESTERN CWA COULD BRING A FEW SHOWERS TO OUR WESTERN CWA ON SAT. LASTLY THE GLOBAL GUIDANCE SUGGEST A QUICK CLIPPER PASSING THROUGH AT THE BEGINNING OF NEXT WEEK BUT TIMING AND TRACK DIFFERENCES MEANT LOW CONFIDENCES IN THE POP AND TEMP FIELDS. RMS/TWH && .AVIATION... SURFACE WINDS AT KBIL AND KSHR WILL HAVE GUSTS APPROACHING 50KTS THE REST OF THE AFTERNOON AND EARLY THIS EVENING. WINDS AT KLVM HAVE DECREASED SOME AND SHOULD REMAIN BELOW 40KTS THIS EVENING BUT ARE EXPECTED TO INCREASE AGAIN TO NEAR 50KTS TUESDAY MORNING. SCATTERED SHOWERS WILL PRODUCE LOCAL MVFR CONDITIONS FROM KBIL TO KMLS TO KSHR THROUGH THE LATE EVENING HOURS. MOUNTAINS WILL BE OBSCURED...ESPECIALLY THIS EVENING. TWH && .PRELIMINARY POINT TEMP/POPS... TUE WED THU FRI SAT SUN MON ----------------------------------------------------------- BIL 033/059 036/059 043/058 038/055 035/052 029/051 030/048 42/W 11/B 13/W 21/N 11/B 11/B 12/W LVM 038/056 036/058 041/052 036/049 032/046 025/046 026/044 51/N 11/N 14/W 31/N 22/W 21/B 12/W HDN 031/060 033/060 036/060 037/055 033/053 028/050 029/047 43/W 11/B 13/W 31/N 11/B 11/B 12/W MLS 028/053 029/056 034/059 040/056 033/052 029/048 030/049 25/W 10/B 13/W 41/N 11/N 11/B 12/W 4BQ 029/055 030/058 035/062 038/055 032/052 028/048 027/048 34/W 10/B 03/W 41/N 11/B 11/B 12/W BHK 025/044 026/051 032/060 038/053 030/049 027/044 026/045 24/W 10/B 11/B 51/N 11/N 11/B 12/J SHR 029/056 029/057 034/059 032/051 029/051 025/047 022/046 62/J 10/B 03/W 31/N 12/W 11/B 12/W && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...HIGH WIND WARNING IN EFFECT UNTIL 8 PM MST THIS EVENING FOR ZONES 28>31-34-35-38-41-42-57-58-63. WY...HIGH WIND WARNING IN EFFECT UNTIL 8 PM MST THIS EVENING FOR ZONE 99. WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM MST THIS EVENING FOR ZONE 98. && $$ WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
341 PM CST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 335 PM CST MON FEB 15 2016 THE MAIN FORECAST CHALLENGES THROUGH TUESDAY AFTERNOON ARE PRECIPITATION AND TEMPERATURES. A POTENT SHORTWAVE ALONG WITH A SURFACE/LOW LEVEL TROUGH WILL CROSS THE FORECAST AREA THIS EVENING AND TONIGHT. THE CIRRUS DECK...WHICH EXTENDS INTO THE DAKOTAS AND MONTANA BASED ON IR/WV...HAS BEEN RATHER DENSE TODAY WHICH HAS SLOWED THE RISE IN TEMPS. DESPITE MID/UPPER LEVEL MOISTURE AND WEAK RADAR ECHOES OVER THE PANHANDLE AND NORTHWEST NEBRASKA TODAY...ABUNDANT DRY LEVEL AIR HAS JUST LED TO VIRGA. THIS EVENING AND TONIGHT...EXPECT SATURATION TO SLOWLY WORK DOWN TO ABOUT 800-850HPA AS INDICATED IN NAM...GFS...AND RAP FORECAST SOUNDINGS. THE RAP ALSO SHOWS SUFFICIENT LOW LEVEL LIFT TO SUPPORT SHOWER ACTIVITY...ESPECIALLY ACROSS NORTHERN NEBRASKA. BASED ON SOME VIRGA IN SOUTHWEST NEBRASKA AND LAPSE RATES OF 7-8C/KM DIRECTLY ABOVE THE SFC INVERSION FROM RAP SOUNDINGS...EXPANDED SCHC MENTION TO COVER THE REST OF THE CWA. A 120+KT 250HPA JET ENTERS THE AREA LATE TONIGHT...ADDING TO THE UPPER LEVEL DYNAMICS AND DIVERGENCE. WITH SFC TEMPS IN THE UPPER 30S/LOWER 40S THROUGH 06Z AND SFC WET BULB AOA 0C...EXPECT PREDOMINANT PTYPE TO BE RAIN. DRY AIR ENTRAINS INTO THE SYSTEM FROM THE WEST BY 06Z...LIMITING PRECIP CHANCES TO NORTH CENTRAL NEB. CUT MENTION TO SPRINKLES NEAR KONL WITH BULK OF MOISTURE STAYING BELOW 800HPA AND THE LOSS OF APPRECIABLE LIFT. A FEW SNOWFLAKES MAY MIX IN AT THE END...BUT MOISTURE REALLY SHUTS OFF WHEN THE TEMPERATURE PROFILE WOULD SUPPORT FZRA OR RASN. MADE LITTLE ADJUSTMENT TO MIN TEMPS AS THEY GENERALLY LIE NEAR MOS GUIDANCE...PRIMARILY MAV AND ECM. TEMPS REMAIN RATHER MILD DUE TO CONTINUED CLOUD COVER AND GUSTY WINDS. WENT SLIGHTLY ABOVE GUIDANCE FOR WIND SPEED DURING THE FROPA AS NORTHWEST 850HPA WINDS OF 35-45KTS ARE SHOWN BY THE NAM AND RAP. CONFIDENCE IN MIN TEMPS A LITTLE LOWER SOUTH OF I-80 WHERE SOME PARTIAL CLEARING AND LIGHTENING OF WINDS TOWARD DAWN IS POSSIBLE...LEADING TO COOLER TEMPS. TUESDAY...TRENDED MAX TEMPS DOWN A DEGREE OR SO FOR MOST LOCATIONS BUT STILL REMAIN MILD WITH 50S SW AND 40S NC. MODELS SHOW CAA FOR MOST OF THE DAY AND 850HPA TEMPS BELOW 0C UNTIL 00Z WED. ANOTHER MOSTLY CLOUDY DAY IS LIKELY AS THE MOISTURE PLUME AS SHOWN BY WV IMAGERY EXTENDS WELL TO THE NORTHWEST. ALSO...ANOTHER BOUNDARY EXITS THE PANHANDLE IN THE AFTERNOON...HELPING ENHANCE LOWER LEVEL LIFT. THE NAM SHOWS BROAD ISENTROPIC LIFT AT 290K ACROSS THE SANDHILLS AFTER 18Z AND 500HPA TEMPS NEAR -20C. FAR WEST/PANHANDLE...WHERE DOWNGLIDE WILL TAKE EFFECT EARLIER AFTER THE BOUNDARY PASSAGE AND 850HPA WAA...MAX TEMPS MAY BE ON THE COOL SIDE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 335 PM CST MON FEB 15 2016 LONG TERM DOMINATED BY ABOVE NORMAL TEMPERATURES AND LITTLE IF ANY CHANCE FOR PRECIPITATION. DURING THE MIDDLE PART OF THE WORK WEEK THE WESTERN RIDGE WILL MIGRATE EAST AND AMPLIFY OVER THE PLAINS. A WARM FRONT WILL LIFT ACROSS THE AREA WITH A THERMAL RIDGE PEAKING ON THURSDAY BEFORE A COLD FRONT MOVES THROUGH THURSDAY NIGHT. WITH THE FRONTAL PASSAGE A SLIGHT CHANCE FOR A RAIN SHOWER IS POSSIBLE NEAR THE NEB/S DAKOTA BORDER...HOWEVER WOULD NOT BE SURPRISED IF THE DRY LOWER LEVELS IS TOO MUCH TO OVERCOME AND NOTHING REACHING THE GROUND. BEHIND THE FRONT WEAK RIDGING REBUILDS QUICKLY ACROSS THE ROCKIES...KEEPING TEMPS ABOVE SEASONAL NORMS INTO THE WEEKEND. WARMEST DAY OF THE PERIOD IS EXPECTED TO BE THURSDAY AS MODELS SURGE 850 MB TEMPS WELL INTO THE TEENS TO AROUND 20 C. MOS GUIDANCE IS ALSO UNSEASONABLY HIGH WITH UPPER 60S TO LOWER 70S. SHOULD HAVE MOST OF THE SNOW MELTED BY THEN AND MODELS INDICATING BREEZY CONDITIONS SO MIXING SHOULD BE REALIZED AND FORECAST FOLLOWS CLOSE TO GUIDANCE. RECORDS THIS TIME OF YEAR ARE LOWER 70S...SO WILL HAVE TO MONITOR AS A RECORD HIGH MAY BE REACHED. ALSO GOING TO HAVE TO WATCH FIRE CONDITIONS...AS OFTEN WITH RECORD WARMTH IS A HIGH FIRE DANGER. MIN RH VALUES LIKELY NEAR 20 PERCENT IN A FEW LOCATIONS...AND COULD BE LOWER. WHILE THE PACIFIC COLD FRONT THURSDAY NIGHT WILL KNOCK DOWN TEMPS FOR THE WEEKEND...GUIDANCE STILL HAS TEMPS REBOUNDING TO AROUND 60...WHICH WILL BE ABOVE NORMAL. ANOTHER WEAK COLD FRONT WILL ARRIVE OVER THE WEEKEND WITH ANOTHER COOL DOWN EXPECTED. LIMITED MOISTURE WITH THIS FRONT AND FORECAST REMAINS DRY. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1122 AM CST MON FEB 15 2016 CIRRUS WILL CONTINUE TO OVERSPREAD WESTERN NEBRASKA THIS AFTERNOON AND CIGS WILL GRADUALLY FALL AS MOISTURE FILLS IN. THE BEST CHANCE OF PRECIPITATION LIES ACROSS NORTHERN NEBRASKA THIS EVENING AND TONIGHT...PRIMARILY FROM KAIA TO KBBW AND NORTH...BUT A FEW SHOWERS CANNOT BE RULED OUT SOUTH. AT THIS TIME...ALL PRECIP SHOULD FALL AS RAIN AND SURFACE TEMPS REMAIN ABOVE FREEZING. HOWEVER...SOME CIGS MAY APPROACH MVFR AT NORTHERN TERMINALS. A LARGE WIND SHIFT WILL OCCUR LATE THIS EVENING WITH A COLD FRONT PASSAGE...SWITCHING TO NORTHWEST AND GUSTING ABOVE 25 KTS. WIND GUSTS SHOULD DIMINISH AND CIGS SHOULD RISE TO VFR BY 12Z TUESDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...SNIVELY LONG TERM...MASEK AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
306 PM CST MON FEB 15 2016 .SHORT TERM...(TONIGHT THROUGH THURSDAY) ISSUED AT 300 PM CST MON FEB 15 2016 NEXT CLIPPER SYSTEM WAS LOCATED OVER WESTERN NORTH DAKOTA AT 20Z WITH MILD TEMPERATURES FOUND ACROSS EASTERN NEBRASKA AND SOUTHWEST IOWA. MAIN CONCERN TONIGHT WILL BE TIMING OF THE FEATURE AS IT MOVES SOUTHEAST ALONG WITH EXTENT AND TYPE OF PRECIP. 19Z RUC BRINGS THE SURFACE LOW INTO EASTERN NEBRASKA PRIOR TO 06Z AND INTO CENTRAL MISSOURI BY 12Z. WITH SURFACE TEMPERATURES EXPECTED TO REMAIN ABOVE FREEZING IN MOST AREAS THROUGH 06Z PRECIP SHOULD BE LIQUID DURING THAT TIME THEN CHANGE OVER TO SNOW OR A RAIN SNOW MIX NORTH TO SOUTH AS TEMPERATURES COOL ALOFT AND SYSTEM TRACKS TO THE SOUTHEAST. SOME POTENTIAL FOR ISOLATED THUNDER IN THE FAR SOUTHEAST LATE TONIGHT WHERE SOME MID LEVEL INSTABILITY INDICATED. LATEST DAY1 OUTLOOK FROM SPC SHOWS AN AXIS FOR GENERAL THUNDER INTO CENTRAL MISSOURI. COOLER AIR FOLLOWS BEHIND THE SYSTEM ON TUESDAY WITH WEAK HIGH PRESSURE OVER THE REGION. WARM ADVECTION BEGINS TUESDAY NIGHT INTO WEDNESDAY AS WESTERN RIDGE STARTS TO MOVE EAST WITH SPRING LIKE TEMPERATURES FOR THE AREA ON THURSDAY. SOUTHEAST PARTS OF THE AREA WHICH HAVE BEEN SNOW FREE FOR MOST OF THE MONTH MAY APPROACH 70. .LONG TERM...(THURSDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST MON FEB 15 2016 MILD PATTERN CONTINUES THROUGH THE PERIOD AS FLOW REMAINS NEARLY ZONAL. SOME PRECIP MAY CLIP NORTHERN PARTS OF THE AREA THURSDAY NIGHT AS FAST MOVING SHORT WAVE TRACKS ACROSS THE NORTHERN PLAINS BUT OTHERWISE LOOKS DRY AFTER THAT. && .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1146 AM CST MON FEB 15 2016 LOW PRESSURE SYSTEM WILL SWING THROUGH EASTERN NEBRASKA THIS EVENING. AHEAD OF IT...SOUTH TO SOUTHWEST WINDS AND INCREASING MID/HIGH CLOUDS ARE FORECAST. AS LOW APPROACHES...AREAS OF RAIN AND MVFR CIGS WILL DEVELOP...FIRST AT KOFK BY 04Z THEN AT KOMA AND KLNK BY 06Z. A MIX OF RAIN AND SNOW IS POSSIBLE AFTER 06Z AT ALL SITES WITH CIGS DROPPING TO NEAR FL010. EXPECT ABOUT 4 HOURS OF POTENTIAL PRECIPITATION BEFORE MOVING OFF TO THE SOUTHEAST. STRONG NORTHWEST WINDS WILL FOLLOW...REACHING THE 20 TO 30KT RANGE AFTER 10Z AND CONTINUING THROUGH END OF TAF PERIOD. MVFR CIGS WILL ALSO SPILL IN BEHIND THIS SYSTEM...AND THOSE COULD GO IFR FOR A TIME BETWEEN 12Z AND 18Z. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...FOBERT LONG TERM...FOBERT AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1214 PM CST MON FEB 15 2016 .SYNOPSIS... ISSUED AT 311 AM CST MON FEB 15 2016 AT 09Z...A WEAK SURFACE TROUGH EXTENDED SOUTH ACROSS THE NORTHERN AND CENTRAL PLAINS. MAINLY CLEAR SKIES IN THE WAKE OF A DEPARTING DISTURBANCE WITH HIGH CLOUDINESS BEGINNING TO PUSH INTO WESTERN SOUTH DAKOTA. SOME WINDS IN WESTERN NEBRASKA HAVE DECOUPLED WITH VALENTINE AT 27 AND NORTH PLATTE 23. OTHER REPORTING STATIONS IN THE LOWER TO MID 30S. && .UPDATE... ISSUED AT 1214 PM CST MON FEB 15 2016 INTRODUCED SPRINKLES IN SOUTHWEST NEBRASKA THIS EVENING. HRRR IS CONSISTENT WITH LIGHT SHOWERS MOVING THROUGH AND RAP FORECAST SOUNDINGS INDICATE LOW LEVEL LIFT AND HIGH RH AS LOW AS 5KFT AGL AT KLBF. TWEAKED MAX TEMPS UP NEAR KONL WHERE MORE CLEARING WAS EXPERIENCED THIS MORNING AND DOWN A DEGREE OR TWO ELSEWHERE WHERE THICK CIRRUS IS SLOWING TEMP RISES. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 311 AM CST MON FEB 15 2016 A DISTURBANCE CURRENTLY MOVING INTO NORTHWEST MONTANA WILL MOVE SOUTHEAST ACROSS WESTERN SD THIS AFTERNOON. THIS WILL OVERSPREAD MID AND HIGH CLOUDINESS ACROSS THE FA THIS AFTERNOON. H85 TEMPS WILL BE MILD RANGING FROM 3C IN THE FAR NORTHEAST TO 10C IN THE FAR SOUTHWEST...MIXING DOWN THESE TEMPERATURES BRINGS MOST HIGHS UP INTO THE 52-55 DEGREES RANGE...EXCEPT UPPER 40S FAR EASTERN ZONES. AFTERNOON CLOUDINESS WILL LIMIT THE WARMUP SO WENT WITH THE WARMER MAV GUIDANCE...AND LOWERED THE WARMEST AREAS A FEW DEGREES. WINDS WILL BE WEST AND WILL INCREASE TO 10 TO 20 MPH THIS AFTERNOON WEST OF HWY 183. THE DISTURBANCE WILL MOVE INTO CENTRAL AND EASTERN SD...NORTHERN AND EASTERN NEBRASKA THIS EVENING. LATEST FCST POPS ARE NEAR PREVIOUS FCST WITH SLIGHT CHC POPS NEAR AND NORTH OF HWY 2 THIS EVENING. RAISED TO A HIGHER 30-40 POPS NORTHEAST OF VALENTINE THROUGH BARTLETT. THIS IS BY NO MEANS AN ORGANIZED SYSTEM...WITH VARYING MODEL SOLUTIONS OF LOCATION OF HIGHER POPS. A LOOK AT GFS BUFKIT SOUNDING AT ONEILL INDICATES A FAIRLY DRY LAYER BELOW 800MB WITH TEMPERATURES FAVORING RAIN AS PRECIP TYPE. THIS WILL ALSO BRING A PACIFIC COLD FRONT ACROSS TONIGHT WITH NORTHWEST WINDS INCREASING TO 15 TO 25 MPH. WITH WINDS DECOUPLING ACROSS THE WEST LATER TONIGHT...LOWS A BIT COLDER NEAR 30...WHILE WINDS STAYING UP ACROSS THE EAST WILL KEEP LOWS NEAR 35. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 311 AM CST MON FEB 15 2016 RIDGING ALOFT WILL BE IN THE PROCESS OF BUILDING NORTHWARD ACROSS THE WESTERN THIRD OF THE COUNTRY TUESDAY...SHIFTING EASTWARD OVER THE CENTRAL PORTIONS OF THE COUNTRY WEDNESDAY INTO THURSDAY. THIS WILL ALL TAKE PLACE AHEAD OF A LONG WAVE TROUGH AND PACIFIC STORM SYSTEM THAT WILL MOVE ONTO THE WEST COAST WEDNESDAY NIGHT. A THERMAL RIDGE WILL BECOME ESTABLISHED ACROSS THE CENTRAL PLAINS BENEATH THE UPPER RIDGING ALOFT...WITH VERY WARM AIR FROM THE SURFACE UP THROUGH THE MID LEVELS OF THE ATMOSPHERE. THIS WILL PEAK THURSDAY WHICH WILL BE THE WARMEST DAY OF THE WEEK. MODELS AGREE THAT H850MB TEMPERATURES WILL EASILY SUPPORT SURFACE TEMPERATURES REACHING 70 DEGREES ACROSS FAR SOUTHWEST NEBRASKA...WITH MID TO UPPER 60S ELSEWHERE. NOT EXPECTING MUCH CIRRUS CLOUD COVER TO HINDER THE WARM UP EITHER...SO CONFIDENT IN THE WARM TEMPERATURE FORECAST. THE AFOREMENTIONED LONG WAVE TROUGH WILL DAMPEN AND QUICKLY CROSS THE CENTRAL AND NORTHERN PLAINS FRIDAY. THIS WILL SEND A PACIFIC COLD FRONT ACROSS THE REGION...WITH TEMPERATURES A FEW DEGREES COOLER BUT STILL WELL ABOVE FRIDAY INTO THE WEEKEND. LITTLE IF ANY PRECIPITATION IS EXPECTED...WHICH IS NORMAL IN THIS TYPE OF UPPER LEVEL PATTERN. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1122 AM CST MON FEB 15 2016 CIRRUS WILL CONTINUE TO OVERSPREAD WESTERN NEBRASKA THIS AFTERNOON AND CIGS WILL GRADUALLY FALL AS MOISTURE FILLS IN. THE BEST CHANCE OF PRECIPITATION LIES ACROSS NORTHERN NEBRASKA THIS EVENING AND TONIGHT...PRIMARILY FROM KAIA TO KBBW AND NORTH...BUT A FEW SHOWERS CANNOT BE RULED OUT SOUTH. AT THIS TIME...ALL PRECIP SHOULD FALL AS RAIN AND SURFACE TEMPS REMAIN ABOVE FREEZING. HOWEVER...SOME CIGS MAY APPROACH MVFR AT NORTHERN TERMINALS. A LARGE WIND SHIFT WILL OCCUR LATE THIS EVENING WITH A COLD FRONT PASSAGE...SWITCHING TO NORTHWEST AND GUSTING ABOVE 25 KTS. WIND GUSTS SHOULD DIMINISH AND CIGS SHOULD RISE TO VFR BY 12Z TUESDAY. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...SNIVELY SYNOPSIS...ROBERG SHORT TERM...ROBERG LONG TERM...TAYLOR AVIATION...SNIVELY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
559 PM EST MON FEB 15 2016 .SYNOPSIS...A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 PM MONDAY... ...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY EXTENDED THROUGH 700 AM TUESDAY MORNING... ...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES EXTENDED THROUGH MIDNIGHT TONIGHT... ...WINTER WEATHER ADVISORY FOR THE REST OF THE PIEDMONT EXTENDED UNTIL 7 PM THIS EVENING... RESIDUAL WEDGE OF ARCTIC HIGH PRESSURE WILL CONTINUE TO SUPPORT LIGHT FREEZING RAIN/DRIZZLE ACROSS THE NORTHERN/NORTHWESTERN PIEDMONT THROUGH THE EVENING...WITH A CHANGE OVER TO RAIN FROM SE TO NW THROUGH THE EVENING HOURS AS A COASTAL WARM FRONT RETREATS INLAND IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHWEST. KGSO RAOB SPECIAL 18Z RELEASE REVEALS THAT THE EXPECTED STRONG/SIGNIFICANT WARMING ALOFT HAS INDEED MATERIALIZE...WARMER AND QUICKER THAN FORECAST....WITH 6 C WARM NOSE NOTED ~875MB. A WARM NOSE OF THIS MAGNITUDE WILL SUPPORT PRECIPITATION PRIMARILY IN THE FORM OF FREEZING RAIN/DRIZZLE ACROSS THE FORECAST AREA UNTIL THE CHANGE OVER TO RAIN AS THE COASTAL FRONT/PRE-FRONTAL WARM SECTOR RETREATS SE TO NW INTO THE AREA. THE HRRR WHICH HAS DONE AN EXCELLENT JOB WITH THE NEAR FREEZING SFC WET-BULB TRENDS ACROSS THE FORECAST AREA(DELINEATES THE CHANGE-OVER FROM FREEZING RAIN TO RAIN)BRINGS THE NEAR FREEZING SFC WET-BULB THROUGH THE TRIANGLE BETWEEN 21 TO 00Z...AND THROUGH THE TRIAD BETWEEN 03 TO 06Z. INTERMITTENT LIGHT FREEZING RAIN AND DRIZZLE WILL SUPPORT A TENTH TO TWO-TENTHS OF AN INCH OF ICE ACROSS THE PIEDMONT...WITH THE HIGHEST AMOUNTS IN THE HEART OF THE DAMMING REGION(WARNING AREA). THE FREEZING RAIN THREAT ACROSS THE TRIAD AND PERSON COUNTY LOOKS TO BE OVER SHORTLY AFTER MIDNIGHT...WITH TEMPERATURES RISING ABOVE FREEZING AS THE PRE-FRONTAL WARM SECTOR OVERTAKES THE AREA. THE WINTER STORM WARNING LIKELY TO BE CANCELLED EARLY(EXPIRES AT 7AM). ATTENTION WILL QUICKLY TURN FROM FREEZING RAIN ACROSS THE NORTHWEST PIEDMONT TO THE POTENTIAL FOR STRONG TO SEVERE STORMS ACROSS EASTERN NC BY AROUND DAYBREAK AS NEGATIVE TILTED MID/UPPER WAVE AND ATTENDANT DEEPENING SFC LOW APPROACH THE AREA FROM THE WEST/SOUTHWEST. STRONG/DEEP ASCENT WITH IN THE RIGHT REAR QUADRANT OF THE UPPER JET STREAK AND ALONG THE NOSE OF A POWERFUL 60-70KT LLJ WILL SUPPORT A CONVECTIVE LINE OF HEAVY RAIN SHOWERS AND POSSIBLY A FEW THUNDERSTORMS. AS THE LINE ENCOUNTERS THE BETTER INSTABILITY IN THE EAST(MUCAPE 200-500 J/KG...STRONG TO SEVERE WIND GUST WILL BE POSSIBLE...ALONG WITH AN ISOLATED TORNADO POSSIBLE. WITH THE PRE-FRONTAL WARM SECTOR SPREADING NORTH INTO THE AREA... TEMPERATURES WILL BE ON THE RISE OVERNIGHT...WARMING IN THE 40S ACROSS THE WEST TO LOWER/MID 50S SE. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 255 PM MONDAY... PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON. INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60- 70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH 18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 310 PM MONDAY... UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY- THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF DEGREES BELOW FREEZING. THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR. MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL- NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS MONDAY BUT KEEP POPS AOB 20%. && .AVIATION /23Z MONDAY THROUGH SATURDAY/... AS OF 555 PM MONDAY... ...DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT... (V)LIFR CONDITIONS; PERIODS OF PRECIPITATION --ALL OCCASIONALLY MODERATE TO HEAVY AND SOME WINTRY FOR THE NEXT SEVERAL HOURS-- AND DEVELOPING LOW LEVEL WIND SHEAR CONDITIONS...WILL AFFECT CENTRAL NC TAF SITES. SCATTERED TO NUMEROUS SHOWERS...INCLUDING MODERATE TO HEAVY FREEZING RAIN ONES OVER TRIAD TAF SITES WHERE TEMPERATURES WILL REMAIN IN THE UPPER 20S TO AROUND 30 DEGREES THROUGH AROUND MIDNIGHT...WILL TRANSITION TO LIQUID ONES AS TEMPERATURES RISE ABOVE FREEZING SHORTLY THEREAFTER. MEANWHILE TO THE EAST...THE TEMPERATURE WILL BREACH FREEZING AND RESULT IN FOLLOWING ALL LIQUID SHOWERY PRECIPITATION FROM SOUTHEAST TO NORTHWEST FROM RWI TO RDU IN THE NEXT FEW HOURS...WHILE THE TEMPERATURE HAS ALREADY RISEN ABOVE FREEZING AT FAY. AN EXPANSION OF LOCALLY DENSE FOG MAY ALSO ACCOMPANY THE ONGOING LIFR CEILINGS TONIGHT...AS A WARM FRONT RETREATS ACROSS THE AREA. THE APPROACH OF A POWERFUL UPPER LEVEL TROUGH AND PASSAGE OF AN ASSOCIATED SURFACE LOW WILL RESULT IN THE EASTWARD MIGRATION OF A BAND OF HEAVY RAIN AND ISOLATED THUNDERSTORMS ACROSS CENTRAL NC LATE TONIGHT AND EARLY TUESDAY. WINDS WESTERLY FLOW AND VFR CONDITIONS WILL DEVELOP IN THE WAKE OF THE BAND OF SHOWERS BY EARLY TUE AFTERNOON. HOWEVER...A FAST-MOVING UPPER LEVEL DISTURBANCE...ON THE HEELS OF THE LEAD ONE TONIGHT...WILL SWEEP EAST ACROSS THE MIDDLE ATLANTIC STATES LATE TUE-EARLY TUE NIGHT. LOW VFR CEILINGS AND LIGHT RAIN MAY RESULT...PARTICULARLY ACROSS NORTHERN TAF SITES. && .RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ008>010-025-026-040-041-073>075. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NCZ011-027-028-042-043-076-077. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ038- 039. WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NCZ007-021>024. && $$ SYNOPSIS...BADGETT NEAR TERM...CBL SHORT TERM...KRD LONG TERM...WSS AVIATION...26
AREA FORECAST DISCUSSION
NWS RALEIGH NC
303 PM EST MON FEB 15 2016 .SYNOPSIS...A COASTAL WARM FRONT WILL ADVANCE INLAND INTO EASTERN SECTIONS OF NORTH CAROLINA TONIGHT AS THE LOW PRESSURE TRACKS THROUGH THE REGION. THE COLD FRONT WILL MOVE EAST ACROSS OUR REGION TUESDAY. && .NEAR TERM /THROUGH TONIGHT/... AS OF 305 PM MONDAY... ...WINTER STORM WARNING FOR THE TRIAD EAST TO PERSON COUNTY EXTENDED THROUGH 700 AM TUESDAY MORNING... ...WINTER WEATHER ADVISORY FOR DAVIDSON AND RANDOLPH COUNTIES EXTENDED THROUGH MIDNIGHT TONIGHT... ...WINTER WEATHER ADVISORY FOR THE REST OF THE PIEDMONT EXTENDED UNTIL 7 PM THIS EVENING... RESIDUAL WEDGE OF ARCTIC HIGH PRESSURE WILL CONTINUE TO SUPPORT LIGHT FREEZING RAIN/DRIZZLE ACROSS THE NORTHERN/NORTHWESTERN PIEDMONT THROUGH THE EVENING...WITH A CHANGE OVER TO RAIN FROM SE TO NW THROUGH THE EVENING HOURS AS A COASTAL WARM FRONT RETREATS INLAND IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHWEST. KGSO RAOB SPECIAL 18Z RELEASE REVEALS THAT THE EXPECTED STRONG/SIGNIFICANT WARMING ALOFT HAS INDEED MATERIALIZE...WARMER AND QUICKER THAN FORECAST....WITH 6 C WARM NOSE NOTED ~875MB. A WARM NOSE OF THIS MAGNITUDE WILL SUPPORT PRECIPITATION PRIMARILY IN THE FORM OF FREEZING RAIN/DRIZZLE ACROSS THE FORECAST AREA UNTIL THE CHANGE OVER TO RAIN AS THE COASTAL FRONT/PRE-FRONTAL WARM SECTOR RETREATS SE TO NW INTO THE AREA. THE HRRR WHICH HAS DONE AN EXCELLENT JOB WITH THE NEAR FREEZING SFC WET-BULB TRENDS ACROSS THE FORECAST AREA(DELINEATES THE CHANGE-OVER FROM FREEZING RAIN TO RAIN)BRINGS THE NEAR FREEZING SFC WET-BULB THROUGH THE TRIANGLE BETWEEN 21 TO 00Z...AND THROUGH THE TRIAD BETWEEN 03 TO 06Z. INTERMITTENT LIGHT FREEZING RAIN AND DRIZZLE WILL SUPPORT A TENTH TO TWO-TENTHS OF AN INCH OF ICE ACROSS THE PIEDMONT...WITH THE HIGHEST AMOUNTS IN THE HEART OF THE DAMMING REGION(WARNING AREA). THE FREEZING RAIN THREAT ACROSS THE TRIAD AND PERSON COUNTY LOOKS TO BE OVER SHORTLY AFTER MIDNIGHT...WITH TEMPERATURES RISING ABOVE FREEZING AS THE PRE-FRONTAL WARM SECTOR OVERTAKES THE AREA. THE WINTER STORM WARNING LIKELY TO BE CANCELLED EARLY(EXPIRES AT 7AM). ATTENTION WILL QUICKLY TURN FROM FREEZING RAIN ACROSS THE NORTHWEST PIEDMONT TO THE POTENTIAL FOR STRONG TO SEVERE STORMS ACROSS EASTERN NC BY AROUND DAYBREAK AS NEGATIVE TILTED MID/UPPER WAVE AND ATTENDANT DEEPENING SFC LOW APPROACH THE AREA FROM THE WEST/SOUTHWEST. STRONG/DEEP ASCENT WITH IN THE RIGHT REAR QUADRANT OF THE UPPER JET STREAK AND ALONG THE NOSE OF A POWERFUL 60-70KT LLJ WILL SUPPORT A CONVECTIVE LINE OF HEAVY RAIN SHOWERS AND POSSIBLY A FEW THUNDERSTORMS. AS THE LINE ENCOUNTERS THE BETTER INSTABILITY IN THE EAST(MUCAPE 200-500 J/KG...STRONG TO SEVERE WIND GUST WILL BE POSSIBLE...ALONG WITH AN ISOLATED TORNADO POSSIBLE. WITH THE PRE-FRONTAL WARM SECTOR SPREADING NORTH INTO THE AREA... TEMPERATURES WILL BE ON THE RISE OVERNIGHT...WARMING IN THE 40S ACROSS THE WEST TO LOWER/MID 50S SE. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... AS OF 255 PM MONDAY... PRECIP...IN THE FORM OF RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL BE ONGOING TO START THE DAY ON TUESDAY. THE LEADING EDGE OF THE LINE OF SHOWERS/STORMS IS EXPECTED TO BE QUICKLY RACING FROM THE TRIAD TO THE TRIANGLE BY 12Z AND AND THEN OFFSHORE BY EARLY AFTERNOON. INSTABILITY WILL BE VERY WEAK (BUT NON-ZERO) DURING THE TIME...WITH ONLY A COUPLE HUNDRED J/KG EXPECTED ACROSS THE EASTERN HALF OF THE FORECAST AREA. NEVERTHELESS...THE SPC HAS PLACED THIS AREA IN A MARGINAL RISK GIVEN THE STRONG FORCING AHEAD OF AN APPROACHING ROBUST SHORT WAVE TROUGH. IN ADDITION...AN INTENSE LOW LEVEL JET (60- 70 KNOTS)...WILL BE PRESENT...BUT RAPIDLY SHIFTING OFFSHORE THROUGH 18Z. THEREFORE...DAMAGING WINDS WILL BE POSSIBLE WITH ANY OF THE STRONGER STORMS. REGARDLESS...WINDS WILL BE RATHER GUSTY...EVEN OUTSIDE OF ANY CONVECTION...WITH GUSTS UP TO 30 MPH POSSIBLE. HIGHS SHOULD BE IN THE MID/UPPER 50S TO LOWER 60S. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO SHIFT THROUGH THE REGION TUESDAY NIGHT. THERE WILL BE LIMITED MOISTURE TO WORK WITH BY THIS TIME AND THEREFORE AM NOT EXPECTING TOO MUCH IN THE WAY OF PRECIP OVERNIGHT...JUST AN INCREASE IN SOME CLOUDS. HOWEVER...GIVEN THE STRENGTH OF THIS WAVE...A SLIGHT CHANCE OF SOME LIGHT RAIN WILL BE POSSIBLE...MAINLY ACROSS THE NORTHERN PORTIONS OF THE FORECAST AREA. OVERNIGHT LOWS SHOULD GENERALLY BE IN THE MID TO UPPER 30S. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... AS OF 310 PM MONDAY... UPPER LEVEL TROUGH WILL PERSIST ALONG THE EASTERN SEABOARD WEDNESDAY- THURSDAY...MAINTAINING A CYCLONIC FLOW OVER CENTRAL NC. A SERIES OF UPPER DISTURBANCES ROUNDING THE BASE OF THE TROUGH WILL CAUSE PERIODS OF CLOUDINESS BUT LITTLE IN THE WAY OF PRECIP AS THE MOISTURE...WHILE ENOUGH TO PRODUCE CLOUDS...NOT ENOUGH TO GENERATE PRECIPITATION. TEMPERATURES WILL AVERAGE CLOSE TO NORMAL WITH AFTERNOON TEMPS GENERALLY 50-55 WITH OVERNIGHT LOWS A COUPLE OF DEGREES BELOW FREEZING. THE TROUGH WEAKENS AND LIFTS NEWD BY THE END OF THE WEEK...PERMITTING A PERIOD OF S/W RIDGING TO OCCUR. THIS WILL INITIATE A WARMING PERIOD WITH TEMPERATURES 5-8 DEGREES ABOVE NORMAL BY SATURDAY/SUNDAY. A S/W IN THE NORTHERN BRANCH OF THE JET STREAM WILL CROSS NORTH OF OUR REGION...DRAGGING A MOISTURE STARVED FRONT ACROSS THE AREA LATE SATURDAY-SATURDAY NIGHT. AIR MASS BEHIND THE FRONT OF PACIFIC ORIGIN SO NOT EXPECTING A BLAST OF COLD AIR. MODELS DIVERGE WITH THE STRENGTH OF THE S/W EXITING THE CENTRAL- NORTHERN PLAINS LATE SUNDAY INTO MONDAY WITH THE 00Z ECMWF DEPICTING MORE AMPLITUDE THAN THE 12Z GFS. FOR NOW...WILL INCREASE CLOUDINESS MONDAY BUT KEEP POPS AOB 20%. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 100 PM MONDAY... ...DANGEROUS AVIATION CONDITIONS THROUGH TONIGHT... MOSTLY IFR...(WITH INCREASINGLY LIFR/VLIFR)...CONDITIONS WILL PERSIST THROUGH MUCH OF THE TAF PERIOD. FREEZING RAIN WILL CONTINUE ACROSS THE REGION AND WILL EVENTUALLY TRANSITION TO RAIN FROM SOUTHEAST TO NORTHWEST THROUGH THE EVENING HOURS. THEN...HEAVY RAIN...INCLUDING A POTENTIAL FOR ELEVATED THUNDERSTORMS...IS EXPECTED AT ALL TERMINALS BETWEEN MIDNIGHT AND EARLY TUESDAY AS A STRONG UPPER LEVEL DISTURBANCE AND ASSOCIATED SURFACE LOW PRESSURE SYSTEM TRACK NORTHEAST ACROSS THE SOUTHERN APPALACHIANS/CAROLINAS. IN ADDITION...LOW-LEVEL WIND SHEAR WILL BECOME AN ISSUE (GENERALLY BETWEEN 06-12Z) AS A 50-60 KT SOUTHERLY LOW-LEVEL JET DEVELOPS. DENSE FOG MAY ALSO BECOME A CONCERN TONIGHT AND EARLY TUESDAY AS WARM AIR ADVECTS OVER COLDER GROUND...ESPECIALLY IN THE TRIAD. INT/GSO TERMINALS CAN EXPECT FZDZ/FZRA THE REMAINDER OF THE AFTERNOON UNTIL TEMPERATURES RISE ABOVE FREEZING LATER THIS EVENING. FURTHER EAST...THE RDU/RWI TERMINALS CAN EXPECT FZRA/FZDZ UNTIL APPROXIMATELY 21Z. AS OF 18Z...TEMPS HAVE JUST ABOUT REACHED FREEZING AT THE FAY TERMINAL AND THEREFORE ANY PRECIP THAT FALLS NOW SHOULD BE RAIN. HEAVY RAIN AND ISOLATED THUNDERSTORMS WILL MOVE ACROSS THE AREA AFTER MIDNIGHT BEFORE EXITING THE REGION BETWEEN 15-18Z ON TUESDAY. OUTLOOK...VFR CONDITIONS WILL RETURN IN THE WAKE OF A COLD FRONTAL PASSAGE TUE AFTERNOON...WITH WESTERLY WINDS AT 10-15 KT GUSTING UP TO 25 KT UNTIL SUNSET. VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH MID/LATE WEEK. && .RAH WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ008>010-025-026-040-041-073>075. WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NCZ011-027-028-042-043-076-077. WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NCZ038- 039. WINTER STORM WARNING UNTIL 7 AM EST TUESDAY FOR NCZ007-021>024. && $$ SYNOPSIS...BADGETT NEAR TERM...CBL SHORT TERM...KRD LONG TERM...WSS AVIATION...KRD/VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1149 AM EST MON FEB 15 2016 .SYNOPSIS... ARCTIC AIR WILL BE SLOW TO ERODE TODAY AS A WARM FRONT OFFSHORE SLOWLY MOVES WESTWARD. THIS FRONT SHOULD MOVE INLAND TONIGHT WITH A SOAKING RAIN EXPECTED INTO EARLY TUESDAY. DRY WEATHER IS EXPECTED FOR THE REMAINDER OF THE WEEK WITH WARM TEMPERATURES DEVELOPING NEXT WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 930 AM MONDAY...ONLY ISOLATED PATCHES OF LIGHT RAIN OVER THE EXTREME SOUTHERN AND WESTERN PORTIONS OF THE FORECAST AREA AT THIS TIME. THERE HAS BEEN SLIGHT WARMING THE FIRST FEW HOURS AFTER SUNRISE AND AT 9 AM UTC THE SURFACE FREEZING LINE WAS ALONG A LINE FROM HARTSVILLE THROUGH DILLON AND BLADENBORO TO PENDERLEA. SO IF ANY PRECIPITATION FALLS INTO AREAS NORTH OF THIS LINE OVER THE NEXT SEVERAL HOURS PATCHY FREEZING RAINY IS STILL POSSIBLE SO WILL CONTINUE THE FREEZING RAIN ADVISORY. A COASTAL FRONT CONTINUE TO LURK ALONG THE COAST WITH THE ILM TEMPERATURE NOW UP TO 40 DEGREES. THE 14 UTC HRRR SHOW THE COASTAL FRONT MAKING IT ONSHORE AROUND 17 UTC. AS THE FRONT SHIFTS ONTO THE COAST THE ISENTROPIC FLOW CHANCES FOR MORE WIDE SPREAD PRECIPITATION WILL INCREASE AT THE COAST BY THE AFTERNOON AND SPREAD INLAND. ...FROM PREVIOUS DISCUSSION... TEMPERATURES WILL RISE OVERNIGHT AS THE WARM FRONT MAKES MORE RAPID WESTWARD PROGRESS WITH THE TOTAL BREAKDOWN OF THE COLD WEDGE AND ITS SUPPORTING HIGH. THE MOST SUBSTANTIAL RAINFALL SHOULD ARRIVE LATE TONIGHT AS A STRONG 500 MB DISTURBANCE ROLLS ACROSS THE AREA. DEEP MOISTURE AND EVEN SOME ELEVATED CONVECTIVE INSTABILITY SHOULD ENHANCE RAINFALL RATES AND IT`S POSSIBLE 0.50 TO 1.00 INCHES OF RAIN COULD FALL TONIGHT. WITH SURFACE-BASED PARCELS LIKELY TO REMAIN STABLE I AM NOT CONCERNED ABOUT SEVERE WEATHER POTENTIAL...HOWEVER DON`T BE SURPRISED IF THE RADAR SHOWS SEVERAL ROTATING STORMS OUT OVER THE GULF STREAM LATE TONIGHT. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...THE LATEST SPC OUTLOOK CONTINUES TO DISPLAY A MARGINAL RISK FOR SEVERE STORMS FOR PORTIONS OF THE FORECAST AREA TUESDAY MORNING IN ASSOCIATION WITH A PRE-FRONTAL TROUGH/APPROACHING COLD FRONT. AROUND DAYBREAK...GUIDANCE PLACES THE NORTH-SOUTH EXTENDED COLD FRONT ACROSS THE CENTRAL CAROLINAS AS A PRE-FRONTAL TROUGH AHEAD OF THE SYSTEM ESSENTIALLY PLACES OUR FORECAST AREA IN THE WARM SECTOR. WITH PWATS IN THE 1 INCH TO 1.25 INCHES RANGE...ANTICIPATE WIDESPREAD RAINFALL DURING THE MORNING COMMUTE...HEAVY IN NATURE AT TIMES. SEVERE WEATHER WISE...WEAKER LAPSE RATES ALONG WITH COLDER SEA TEMPERATURES AND LACK OF ANY DIURNAL HEATING GIVEN EARLY ONSET OF ACTIVITY WILL RESTRICT INSTABILITY. HOWEVER...WILL NOTE THE HEALTHY LOW LEVEL JET THAT WILL BE IN PLACE OF AROUND 50 KTS AS WELL AS THE LOW LEVEL WIND SHEAR AS NOTED BY THE 0-3KM HELICITY VALUES OF UP TO AROUND 200 M2/S2 POSSIBLE. AS A RESULT...INTERMITTENT DAMAGING WINDS ARE POSSIBLE. AS THE COLD FRONT PUSHES OFFSHORE BY EARLY AFTERNOON...EXPECT IMPROVING CONDITIONS AND A DRYING TREND BEHIND THE SYSTEM FOR THE REST OF THE DAY ON TUESDAY. ANOTHER SHORTWAVE/FRONT WILL PUSH THROUGH LATE OVERNIGHT TUESDAY INTO EARLY WEDNESDAY...BUT DO NOT ANTICIPATE ANY PRECIPITATION WITH THIS FEATURE AS LATEST GUIDANCE KEEPS AVAILABLE MOISTURE NORTH OF THE AREA. MAINLY ABOVE NORMAL TEMPERATURES EXPECTED FOR THE SHORT TERM...WITH HIGHS IN THE MID 60S ON TUESDAY AND AROUND 60 ON TUESDAY. LOW TO MID 40S FOR OVERNIGHT LOWS TUESDAY INTO WEDNESDAY WILL DIP DOWN INTO THE MID TO UPPER 30S AS COLD AIR ADVECTION RAMPS UP BEHIND THE SECONDARY COLD FRONT. && .LONG TERM /THURSDAY THROUGH SUNDAY/... AS OF 300 AM MONDAY...EXPECT A COOL AND DRY START TO THE EXTENDED PERIOD WITH A GRADUAL WARMING TREND THROUGH THE REMAINDER OF THE WEEK AS FAIRLY WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE SOUTHEAST. HIGH TEMPERATURES ON THURSDAY WILL BE JUST BELOW NORMAL IN THE MID TO UPPER 50S...CLIMBING INTO THE MID TO UPPER 60S BY THE WEEKEND AND INTO EARLY NEXT WEEK. OVERNIGHT LOWS START OFF IN THE UPPER 30S...REACHING THE MID TO UPPER 40S. THE ONLY NOTABLE WEATHER SYSTEM WITHIN THE EXTENDED WILL BE TOWARDS THE END OF THE PERIOD...STEMMING FROM A SURFACE LOW PRESSURE SYSTEM WHICH MOVES ACROSS THE NORTHERN GREAT LAKES REGION INTO SOUTHERN CANADA FRIDAY INTO SATURDAY. THOUGH THE TEMPORAL AND SPATIAL NATURE OF THE EXTENDING FRONTAL BOUNDARY INTO THE CAROLINAS REMAINS UNCERTAIN AT THIS TIME...EXPECT INCREASING CLOUDS ON SUNDAY. ANY PRECIPITATION THAT DOES OCCUR SUNDAY INTO MONDAY AS A RESULT WILL FALL AS ALL RAIN AS TEMPERATURES REMAIN WELL ABOVE FREEZING. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... AS OF 18Z...EVERYONE SHOULD BE ABOVE FREEZING SO NO LONGER A FREEZING RAIN THREAT THIS AFTERNOON. PRECIPITATION WILL BE VERY SPOTTY AND LIGHT. WINDS WILL VEER TO THE SOUTHEAST ALONG THE COAST...WITH THE STUBBORN WEDGE HOLDING AT THE INLAND TERMINALS AT LEAST INTO THIS EVENING. OVERNIGHT...SOME PRETTY SERIOUS DYNAMICS MOVE INTO THE REGION WITH A NEGATIVELY TILTED UPPER TROUGH AND GOOD HELICITY TOWARD MORNING. A VERY STRONG LOW LEVEL JET WILL ADD TO THE MOISTURE TRANSPORT...AND A BAND OF HEAVY SHOWERS WILL SWEEP THROUGH THE REGION FROM 08Z-13Z. THERE COULD BE ENOUGH CAPE FOR SOME OF THE WINDS AT 1-2K FEET TO COME DOWN TO THE SURFACE...THE REASON FOR THE INTERMITTENT GUSTS TO 35 KTS. WOULD NOT BE SURPRISED IF THEY WERE EVEN HIGHER AT THE COASTAL TERMINALS. TIME HEIGHT SHOWS THAT THE CONVECTION SHOULD SHUT OFF FAIRLY ABRUPTLY AFTER 12Z...WITH STRONG SOUTHWEST WINDS EXPECTED. EXTENDED OUTLOOK...VFR THROUGH FRIDAY MORNING. MVFR CONDITIONS ARE POSSIBLE LATE FRIDAY AND SATURDAY WITH A WEAK FRONTAL BOUNDARY MOVING INTO THE VICINITY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 630 AM MONDAY...A WARM FRONT CURRENTLY LOCATED 25-40 MILES EAST OF THE BEACHES WILL CRAWL WESTWARD...APPROACHING THE COAST NORTH OF CAPE FEAR AROUND NOON...AND FINALLY REACHING THE SC COAST INCLUDING THE GRAND STRAND BY LATE IN THE DAY. THIS BOUNDARY WILL SEPARATE S TO SE WINDS ON THE EAST (WARM) SIDE FROM NE WINDS ON THE WEST (COLD) SIDE. STRENGTHENING SE WINDS WELL OFFSHORE SHOULD LEAD TO INCREASING SWELL TODAY AND A SMALL CRAFT ADVISORY WILL REMAIN POSTED EVEN FOR AREAS WHERE WIND SPEEDS REMAIN WELL BELOW 25 KNOTS. BY TONIGHT THE WARM FRONT SHOULD MOVE COMPLETELY ONSHORE AND STRENGTHENING SSE WINDS SHOULD REACH 25 KNOTS...ESPECIALLY ACROSS THE WARMER SEA SURFACE TEMPERATURES GREATER THAN 10 MILES FROM SHORE. SWELL WILL CONTINUE TO BUILD AND ITS POSSIBLE WE COULD SEE SEA HEIGHTS EXCEEDING 10 FEET LATE TONIGHT NEAR CAPE FEAR. WAVES OF RAIN DEVELOPING THIS MORNING MAY DIMINISH THIS EVENING...HOWEVER RAIN SHOULD REDEVELOP LATE TONIGHT AND MAY BE ACCOMPANIED BY A FEW STRONG THUNDERSTORMS. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT THROUGH TUESDAY AFTERNOON. A PRE-FRONTAL TROUGH WILL PUSH ACROSS THE WATERS TUESDAY MORNING ALLOWING FOR SOUTHERLY WINDS 15 TO 25 KTS TO PREVAIL...FOLLOWED BY A COLD FRONT WHICH PUSHES OFFSHORE JUST TO THE NORTH AND WINDS VEERING SOUTHWESTERLY TO WESTERLY...15 TO 20 KTS. WILL SEE A DECREASE IN SUSTAINED WINDS TO AROUND 10 TO 15 KTS INTO EARLY WEDNESDAY MORNING AS WEAK HIGH PRESSURE BEGINS TO BUILD IN...VEERING WINDS EVEN MORE TO NORTHWEST. ALONG WITH WINDS...SEAS UP TO 6 TO 10 FT WILL WARRANT A SMALL CRAFT ADVISORY FOR THE WATERS THROUGH THE DAY ON TUESDAY...POSSIBLY CONTINUING INTO THE EVENING HOURS. SEAS DROP OFF ON WEDNESDAY TO 3 TO 5 FT. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 AM MONDAY...WEAK HIGH PRESSURE REMAINS IN PLACE ACROSS THE WATERS TOWARDS THE END OF THE WEEK. NORTHERLY WINDS 10 TO 15 KTS WILL PREVAIL ON THURSDAY...BECOMING NORTHEASTERLY ON FRIDAY AS HIGH PRESSURE SHIFTS OFFSHORE. SEAS OF 2 TO 4 FT EXPECTED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR SCZ017-023-024. NC...FREEZING RAIN ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR NCZ087-096. MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST TUESDAY FOR AMZ250-252-254- 256. && $$ NEAR TERM...DRH/TRA SHORT TERM...SGL LONG TERM...SGL AVIATION...DL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
334 PM CST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 334 PM CST MON FEB 15 2016 AN ACTIVE PATTERN WILL CONTINUE THE NEXT FEW DAYS...WITH A BRIEF COOL-DOWN EXPECTED ON TUESDAY. AS OF 21 UTC...LOW- AND MID-LEVEL SATURATION HAS BEEN TAKING PLACE AT A SLOWER RATE THAN PERHAPS EXPECTED BASED ON A LACK OF SURFACE PRECIPITATION REPORTS AND RELATIVELY ANEMIC REFLECTIVITY ON 0.5 DEGREE RADAR DATA. RECENT HIGH-RESOLUTION...RAPID-REFRESH MODEL GUIDANCE /INCLUDING THE RAP AND HRRR/ STILL SUPPORTS THE FORMATION OF LIGHT PRECIPITATION OVER WESTERN AND CENTRAL ND BY 00 UTC WITH THE PASSAGE OF A MID-LEVEL SHORTWAVE TROUGH. HOWEVER...THAT MODEL GUIDANCE HAS ALSO BEEN TRENDING LOWER WITH QPF...AND SINCE THAT IS IN LINE WITH OBSERVATIONAL TRENDS WE BELIEVE THAT TO BE ACCURATE. OUR FORECAST THUS CALLS FOR AN INCH OR LESS OF SNOW ACCUMULATION THROUGH TONIGHT FROM NORTH CENTRAL ND INTO THE JAMES RIVER VALLEY. THERMAL PROFILES SUPPORT RAIN INITIALLY OVER WESTERN AND PARTS OF SOUTH CENTRAL ND...BEFORE A SWITCH TO POSSIBLE LIGHT SNOW BY THE TIME THE BULK OF THE PRECIPITATION IS WINDING DOWN THIS EVENING. WE ARE STILL CALLING FOR A PERIOD OF NORTHWEST WIND GUSTS TO ABOUT 30 MPH THIS EVENING BEHIND THE SHORTWAVE TROUGH AND ACCOMPANYING SURFACE COLD FRONT BASED ON RAP-FORECAST 3-HOUR SURFACE PRESSURE CHANGES OF 3-5 MB /HIGHEST IN SOUTHWEST ND/. GUIDANCE SUGGESTS AN AREA OF STRATUS /LOW CLOUDS/ WILL FOLLOW THE SYSTEM LATE TONIGHT INTO TUESDAY...WITH SOME HINTS OF ADDITIONAL...WEAK IMPULSES IN LINGERING CYCLONIC NORTHWEST FLOW ALOFT. WE HAVE LOW POPS IN PLAY FOR SOME LIGHT SNOW OVER CENTRAL ND AFTER 06 UTC TO ACCOUNT FOR THAT...BUT FORECAST SOUNDINGS SUGGEST THE STRATUS DECK MIGHT BE WARMER THAN -12 C...SUGGESTING SOME RISK OF FREEZING DRIZZLE. WE CHOSE TO WITHHOLD THAT FROM THE FORECAST AT THIS POINT WITH WEAK VERTICAL MOTION IN THAT LAYER PER MODEL GUIDANCE. MOREOVER...THE PRECIPITATION-TYPE ALGORITHM OUTPUT FROM THE 12 UTC GLOBAL MODEL OUTPUT AND MORE RECENT HRRR AND RAP GUIDANCE SUPPORTS LIGHT SNOW AS THE PRIMARY TYPE WITH ANY LIGHT PRECIPITATION THAT MAY OCCUR AFTER MIDNIGHT AND INTO EARLY TUESDAY MORNING. THAT WILL REQUIRE MONITORING THOUGH. ON TUESDAY...A SURFACE RIDGE WILL BUILD INTO EASTERN ND AND WILL BRING A COLDER DAY TO THE AREA. WARM AIR ADVECTION WILL BEGIN TO THE WEST ACROSS MT THOUGH AND THE 12 UTC GUIDANCE ALL SUGGESTS A BAND OF LIGHT SNOW WILL MOVE INTO WESTERN ND DURING THE DAY AND INTO CENTRAL ND BY EARLY TUESDAY EVENING. THIS WOULD BE ANOTHER LIGHT QPF EVENT WITH LITTLE IN THE WAY OF IMPACTS. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 334 PM CST MON FEB 15 2016 ACTIVE PERIOD WITH SEVERAL SYSTEMS SLIDING THROUGH WESTERN AND CENTRAL NORTH DAKOTA...APPROXIMATELY ONE EVERY 24HR TO 48HR. WE ARE LIKELY TO SEE A COMBINATION OR RAIN...SNOW...AND/OR LIGHT FREEZING DRIZZLE AT TIMES WITH THESE SYSTEMS. SUCCESSIVE WARM AIR ADVECTION/PRECIPITATION EVENTS WILL EVENTUALLY RESULT IN A GRADUAL WARMING TREND LATER IN THE WEEK. THE NAEFS 850T-500T SHOWS A FAIRLY STRONG THERMAL RIDGE SHIFTING OVER NORTH DAKOTA THURSDAY. 850 TEMPS OF +8C TO +10C WILL BE COMMON RESULTING IN SURFACE HIGHS IN THE 40S TO LOWER 50S. FOR TUESDAY NIGHT INTO WEDNESDAY MORNING...FIRST SHORTWAVE IN THE LONG TERM PERIOD EMBEDDED WITHIN A NORTHWEST FLOW WILL MOVE FROM WITH A SURFACE LOW REFLECTED IN SOUTHEAST MONTANA SHIFTING INTO CENTRAL SOUTH DAKOTA THROUGH WEDNESDAY MORNING. ANOTHER...STRONGER SHORTWAVE TROUGH HAS BEEN CONSISTENTLY SHOWN TO CROSS THE REGION THURSDAY NIGHT INTO FRIDAY BY THE LAST SEVERAL RUNS OF THE GFS AND ECMWF. A MIX OF PRECIPITATION IS POSSIBLE WITH THAT WAVE...AND STRONG WINDS ARE POSSIBLE ON ITS BACK SIDE IF THE 12 UTC GFS AND ECMWF ARE RIGHT WITH 850-MB WINDS UP TO 55 KT FROM THURSDAY NIGHT INTO FRIDAY. FINALLY...THERE ARE HINTS OF ONE MORE SHORTWAVE TROUGH PASSAGE ON SATURDAY OR SUNDAY...SUPPORTIVE OF MORE LOW POPS IN THAT PERIOD. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 334 PM CST MON FEB 15 2016 A MIX OF RAIN AND SNOW IS POSSIBLE THROUGH THIS EVENING. MVFR CEILINGS AND VISIBILITIES ARE LIKELY BY EVENING...ESPECIALLY IN CENTRAL ND. SOME GUIDANCE DOES SHOW AT LEAST SOME POTENTIAL FOR IFR CEILINGS BY THE EARLY MORNING HOURS ON TUESDAY OVER KMOT/KJMS. THE OTHER CONCERN WILL BE BREEZY WINDS FROM THE NORTHWEST OVER THE STATE FROM 00-06Z TUESDAY MORNING. WINDS COULD GUST AS HIGH 30 KNOTS OVER SOUTHWEST...WEST CENTRAL...AND CENTRAL ND. && .HYDROLOGY... ISSUED AT 334 PM CST MON FEB 15 2016 ICE RESTRICTIONS IN THE CHANNEL AND SOME CONTRIBUTION FROM LOCAL RUNOFF DUE TO RECENT SNOWMELT HAS CAUSED THE MISSOURI RIVER TO RISE IN THE BISMARCK/MANDAN AREA. WE ARE MONITORING THE SITUATION CLOSELY AND ARE PROVIDING INFORMATION IN A HYDROLOGIC OUTLOOK ON OUR WEB PAGE. RIGHT NOW THE MAIN MESSAGE WE ARE CONVEYING IS THAT THERE WILL BE SHARP FLUCTUATIONS...WITH RAPID RISES FOLLOWED BY LOWER LEVELS...UNTIL THE ICE IS NATURALLY REMOVED BY MIDWEEK. .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...CJS LONG TERM...KS/CJS AVIATION...ZH/CJS HYDROLOGY...CJS/KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
116 PM CST MON FEB 15 2016 .UPDATE... ISSUED AT 115 PM CST MON FEB 15 2016 NO CHANGES NEEDED FOR THIS UPDATE. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CST MON FEB 15 2016 FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE BLEND FOR NOW. A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF CLOUD COVER. NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST SW OF THE FA. FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING COOLER TEMPERATURES TO THE REGION TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CST MON FEB 15 2016 NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO. HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY. WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD. THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID- LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER AIR FEATURES. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 115 PM CST MON FEB 15 2016 TAFS WILL BE A CHALLENGE TODAY AS DENSE FOG IMPACTS THE DVL REGION...WHERE VSBYS HAVE GONE UP...STRATUS OVER GFK/TVF AREA AND LIGHT MIXED PRECIP MOVING INTO BJI. BELIEVE THE PRECIP WILL MOVE OUT OF BJI OVER THE NEXT COUPLE OF HOURS BUT NOW LESS CONFIDENT GFK-TVF- BJI WILL SEE MVFR CIGS IMPROVE. A SHOT OF LIGHT SNOW WILL MOVE ACROSS THE REGION TONIGHT...ALTHOUGH MODELS DIFFER IN THE TRACK OF THE SNOW. DVL WILL CERTAINLY SEE SOME SNOW WITH CIGS REMAINING IFR...AND FAR WILL SEE MVFR CIGS OVERNIGHT AS IT MOVES THROUGH. LESS CONFIDENT ON THE GFK-TVF REGION ALTHOUGH REDUCED VSBYS TO IFR CONDS IS POSSIBLE WITH SHSN THIS EVENING. WINDS WILL BECOME LIGHT AT BJI...AND EXPECT VSBYS TO DROP TO IFR CONDS THERE AS FZFG IMPACTS THE AERODROME BETWEEN 00Z AND 06Z. MOST LIKELY SCENARIO WILL BE PREDOMINANT MVFR WITHIN AND EAST OF THE VALLEY...PREDOMINANT IFR AT DVL...AND INTERMITTENT IFR CONDS AT FAR/BJI. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...MAKOWSKI/VOELKER AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1250 PM CST MON FEB 15 2016 .UPDATE... ISSUED AT 1250 PM CST MON FEB 15 2016 WE INCREASED POST-FRONTAL WIND SPEEDS TO ADVERTISE GUSTS TO AROUND 30 MPH FOR A TIME THIS EVENING OVER MUCH OF THE AREA BASED ON 3-5 MB/3 HOUR PRESSURE RISES SIMULATED BY RECENT RAP RUNS. THE REST OF THE FORECAST LOOKS ON TRACK WITH RADAR RETURNS STEADILY INCREASING AS OF MIDDAY...WITH LOW-LEVEL SATURATION AND THE RESULTANT CHANCE OF PRECIPITATION STILL EXPECTED TO INCREASE IN MANY PLACES THIS AFTERNOON. SEE THE HYDROLOGY SECTION BELOW FOR INFORMATION ON HIGH WATER ON THE MISSOURI RIVER IN THE BISMARCK-MANDAN AREA. UPDATE ISSUED AT 934 AM CST MON FEB 15 2016 ONLY MINOR CHANGES WERE NEEDED FOR THIS LATEST UPDATE. DID BLEND OBSERVATION TRENDS TO THE FORECAST THROUGH 18 UTC...AND TWEAKED PRECIPITATION CHANCES TO MATCH WHAT A BLEND OF HIGH RESOLUTION GUIDANCE SUGGESTS FOR LATER THIS AFTERNOON. ADDITIONALLY...NUDGED HIGH TEMPERATURES UP BY A DEGREE OR TWO IN THE SOUTHWEST AND SOUTH CENTRAL. UPDATE ISSUED AT 644 AM CST MON FEB 15 2016 NO CHANGES OTHER THAN TO BLEND TO OBSERVED TRENDS THROUGH 12 UTC. WEBCAMS ACROSS SOUTH CENTRAL NORTH DAKOTA AND THE JAMES RIVER VALLEY SUGGEST FOG CONTINUES TO BE PATCHY. ONE THING TO MONITOR IS POTENTIAL SNOWFALL ACCUMULATIONS ACROSS THE NORTH CENTRAL AND JAMES RIVER VALLEY FOR LATER TODAY AND INTO THE EVENING. THE 10-11 UTC RAP/HRRR ITERATIONS...06 UTC NAM AND 00 UTC HI-RES WINDOW WRF ARW/NMM ALL SUGGEST THE POSSIBILITY FOR MORE THAN TWO INCHES OF ACCUMULATION WITH STEEP MID LEVEL LAPSE RATES AND NEGATIVE EPV ALOFT. && .SHORT TERM...(TODAY AND TONIGHT) ISSUED AT 325 AM CST MON FEB 15 2016 AN UPPER LEVEL LOW OVER NORTH CENTRAL CANADA AND A RIDGE OVER THE WEST COAST WILL KEEP NORTHWESTERLY FLOW ALOFT OVER THE STATE TODAY. A WEAK SHORTWAVE IN THE FLOW WAS CURRENTLY MOVING SOUTHEAST ACROSS NORTH CENTRAL NORTH DAKOTA. REGIONAL RADARS WERE DETECTING SOME LIGHT RETURNS ASSOCIATED WITH THE SHORTWAVE...AND THE BOTTINEAU DOT CAM CONFIRMED LIGHT SNOW FALLING AND REACHING THE GROUND. THUS ADDED A MENTION OF LIGHT SNOW EARLY THIS MORNING NORTH CENTRAL. A WEAK SURFACE WARM FRONT/TROUGH EXTENDED FROM MANITOBA TO NEAR DEVILS LAKE TO NEAR BISMARCK AND SOUTH. LARGE AREA OF FOG AND LOW CLOUDS AHEAD OF THE WARM FRONT OVER MINNESOTA AND THE RED RIVER VALLEY. JAMESTOWN HAD BEEN REPORTING VERY LOW VISIBILITY IN FOG AND LOW CLOUDS BEFORE MIDNIGHT...THEN CONDITIONS IMPROVED WITH WEAK SOUTHWESTERLY FLOW AND THE APPROACH OF THE WARM FRONT. A STRONGER SHORTWAVE WAS CURRENTLY OVER SOUTHERN ALBERTA. THE LEADING EDGE OF THE SHORTWAVE ENERGY IS FORECAST TO ENTER WESTERN NORTH DAKOTA BY MID TO LATE MORNING...THEN CONTINUE MOVING SOUTHEAST...EXITING NORTH DAKOTA INTO SOUTHERN MINNESOTA LATE TONIGHT. PRECIPITATION IS EXPECTED TO BEGIN IN THE SOUTHWEST BEFORE NOON...SPREADING INTO CENTRAL NORTH DAKOTA THIS AFTERNOON...ENDING IN THE WEST DURING THE EVENING...AND DISSIPATING IN CENTRAL NORTH DAKOTA LATE TONIGHT. PRECIPITATION TYPE IS THE CHALLENGE...AS WARM AIR BEHIND THE AFOREMENTIONED SURFACE WARM FRONT SHOULD ALLOW LIGHT SNOW SOUTHWEST TO CHANGEOVER TO LIGHT RAIN AS TEMPERATURES RISE INTO THE 30S AND LOWER 40S...WITH WARM TEMPERATURES ALOFT AS WELL. FARTHER NORTH LOOK FOR A MIX OF RAIN AND SNOW AS TEMPERATURES THERE WILL BE MAINLY IN THE 20S...REACHING INTO THE LOW TO MID 30S DURING THE DAY...AND AS TEMPERATURES ABOVE THE SURFACE WILL RISE FOR A SHORT TIME TO ALLOW LIGHT SNOW CHANGING TO RAIN...THEN AS A SURFACE COLD FRONT FOLLOWS THE VIGOROUS UPPER LEVEL SHORTWAVE...THE PRECIPITATION IN THE NORTH CENTRAL CHANGES BACK OVER TO LIGHT SNOW LATE AFTERNOON. LIGHT SNOW ACCUMULATIONS OF AROUND AN INCH ARE EXPECTED FROM BOTTINEAU TO RUGBY AND THE TURTLE MOUNTAINS THROUGH TONIGHT. LOWS TONIGHT SHOULD RANGE FROM THE TEENS NORTH CENTRAL TO THE 20S WEST AND SOUTH. .LONG TERM...(TUESDAY THROUGH SUNDAY) ISSUED AT 325 AM CST MON FEB 15 2016 ABOVE NORMAL TEMPERATURES HIGHLIGHT THE EXTENDED FORECAST. THE 00 UTC SUITES ARE IN GOOD AGREEMENT ON A BROAD UPPER LEVEL RIDGE BUILDING ACROSS THE CENTRAL CONUS THIS WEEK...WITH RESULTANT ABOVE NORMAL TEMPERATURES FOR THE PERIOD. THE 00 UTC NAEFS MEAN 850 MB TEMPERATURE ANOMALIES ARE FORECAST TO CLIMB TO THEIR 97.5 TO 99.5+ PERCENTILES BY THURSDAY ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THIS SUPPORTS THE POTENTIAL FOR WIDESPREAD 50S FOR HIGHS ALONG AND WEST OF THE MISSOURI RIVER BY THURSDAY. REGARDING PRECIPITATION...A WEAK CLIPPER IS FAVORED ACROSS WESTERN AND CENTRAL NORTH DAKOTA ON TUESDAY. PRECIPITATION IS EXPECTED TO BE RAIN ACROSS THE SOUTHWEST...WITH LIGHT SNOW ELSEWHERE GIVEN A SURFACE BASED WARM LAYER. NEW SNOW ACCUMULATIONS OF ONE INCH OR LESS ARE EXPECTED. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED AT 1250 PM CST MON FEB 15 2016 CLOUDS WILL BE ON THE INCREASE FROM WEST TO EAST THROUGH THE AFTERNOON OVER NORTH DAKOTA. SOME LIGHT RAIN SHOWERS WILL DEVELOP OVER THE SOUTHWESTERN PART OF THE STATE THIS AFTERNOON AND SPREAD EAST THROUGH THE OVERNIGHT. PRECIPITATION MAY FALL AS A MIX OF RAIN AND SNOW AT KMOT LATE THIS AFTERNOON...AND AS ALL SNOW AT KJMS TONIGHT. THE RAIN SNOW TRANSITION ZONE WILL LIKELY RUN FROM THE NORTHWEST TO THE SOUTHEAST NEAR OR ALONG THE BOUNDARY OF THE MISSOURI RIVER. MVFR CEILINGS AND VISIBILITIES LOOK LIKELY BEGINNING LATE THIS AFTERNOON...HOWEVER SOME GUIDANCE DOES SHOW AT LEAST SOME POTENTIAL FOR IFR CEILINGS BY THE EARLY MORNING HOURS ON TUESDAY OVER KMOT/KJMS. THE OTHER CONCERN WILL BE BREEZY WINDS FROM THE NORTHWEST OVER THE STATE FROM 00-06Z TUESDAY MORNING. WINDS COULD GUST AS HIGH 30 KNOTS OVER SOUTHWEST...WEST CENTRAL...AND CENTRAL ND. && .HYDROLOGY... ISSUED AT 1250 PM CST MON FEB 15 2016 ICE RESTRICTIONS IN THE CHANNEL AND SOME CONTRIBUTION FROM LOCAL RUNOFF DUE TO RECENT SNOWMELT HAS CAUSED THE MISSOURI RIVER TO RISE IN THE BISMARCK/MANDAN AREA. WE ARE MONITORING THE SITUATION CLOSELY AND ARE PROVIDING INFORMATION IN A HYDROLOGIC OUTLOOK ON OUR WEB PAGE. THAT OUTLOOK WILL BE UPDATED TO REFLECT OUR LATEST EXPECTATIONS THIS AFTERNOON. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...CJS/ZH SHORT TERM...JV LONG TERM...AYD AVIATION...ZH HYDROLOGY...CJS/KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1050 AM CST MON FEB 15 2016 .UPDATE... ISSUED AT 1050 AM CST MON FEB 15 2016 WE HAVE ADDED FOG TO ALL AREAS THROUGH 18Z...GETTING SOME FOG NOW WITH FAIRLY LOW VSBYS IN DVL BASIN. && .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 335 AM CST MON FEB 15 2016 FORECAST CHALLENGES CONCERN TEMPERATURES AND SNOW CHANCES. MODELS SHOWING SOME DIFFERENCES IN POTENTIAL SNOW AMOUNTS SO WILL USE BLEND FOR NOW. A SERIES OF WAVES WILL DROP THROUGH THE FORECAST AREA NEXT COUPLE OF DAYS. THE FIRST CURRENTLY MOVING INTO THE FAR NW FA WITH SOME WEAK RADAR RETURNS. HAVE SOME LOW END POPS EARLY THIS AM TO COVER THIS FEATURE AND WILL MONITOR TO SEE IF JUST MID CLOUD/FLURRIES OR IF THERE IS MEASURABLE SNOWFALL ALTHOUGH VERY MINOR. OTHERWISE WARM ADVECTION CONTINUES AND WITH LOW LEVEL W-SW FLOW TEMPERATURES SHOULD BE ABLE TO GET A FEW DEGREES EITHER SIDE OF 30 IN SPITE OF CLOUD COVER. NEXT STRONGER WAVE WILL PROPAGATE SE THROUGH THE SW HALF OF THE FA THIS EVENING. HIGH RESOLUTION SHORT TERM MODEL GUIDANCE SHOWING BEST POTENTIAL OVER THE FAR WESTERN INTO THE SOUTHERN FA. CURRENT GUIDANCE SHOWING AROUND AN INCH OR SO ACCUMULATION. ECMWF PRETTY WEAK WITH SNOW AMOUNTS VS THE 06Z NAM WHICH HAS COME IN A BIT STRONGER WITH MOISTURE AND ALSO INDICATING SOME WEAK CAPE SO WILL NEED TO MONITOR. RAP CLOSE TO THE NAM BUT SHOWING HIGHER PCPN JUST SW OF THE FA. FOLLOWING PASSAGE OF WAVE QUICK SHOT OF COLD ADVECTION WILL BRING COOLER TEMPERATURES TO THE REGION TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY) ISSUED AT 335 AM CST MON FEB 15 2016 NEXT WAVE TO DROP THROUGH TUESDAY NIGHT. WITH SURFACE HIGH BUILDING INTO THE FA FEEL BEST CHANCES OF SNOW WITH THIS FEATURE WILL BE WEST OF THE FA HOWEVER HAVE SOME LOW POPS OVER THE FAR WEST. CLOUDS WILL HAVE IMPACT ON TEMPERATURES BUT GENERALLY LOOKING AT SINGLE DIGITS ABOVE AND BELOW ZERO. HIGH PRESSURE SHIFTS SE WEDNESDAY ALLOWING FOR RETURN FLOW AND WARM ADVECTION. AFTER COOLER START TEMPERATURES SHOULD BE ABLE TO RECOVER TO AT OR A FEW DEGREES WARMER THAN TUESDAY. WARM ADVECTION CONTINUES WED NIGHT SO MINIMUMS NOT NEAR AS COLD. THURSDAY-SUNDAY...STRONG LOW-LEVEL WARM ADVECTION AHEAD OF A MID- LEVEL TROUGH SHOULD HELP BOOST TEMPS INTO THE 30S ON THURSDAY. BOTH THE 00Z GFS/ECMWF BRING A SFC LOW ACROSS THE SD/ND BORDER AREA INTO MN THUR NIGHT INTO FRIDAY. LIGHT PRECIP OF VARYING TYPES IS POSSIBLE DURING THIS TIME...ALTHOUGH PLACEMENT OF EMBEDDED SHORTWAVE TROUGHS AND STRONGER FORCING DIFFERS AMONG MODELS. A GOOD WESTERLY WIND PUSH BEHIND THE SFC LOW SHOULD KEEP TEMPS VERY MILD ON FRIDAY. THE ABOVE AVERAGE TEMPS WILL CONTINUE INTO THE WEEKEND...ALTHOUGH OVERALL FORECAST CONFIDENCE LOWERS WITH LARGER MODEL DIFFERENCES WITH UPPER AIR FEATURES. && .AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING) ISSUED AT 626 AM CST MON FEB 15 2016 ALTHOUGH MASKED BY HIGHER CLOUDS APPEARS BACK EDGE OF STRATUS HAS STALLED ALONG THE RED RIVER. EAST OF THE RIVER IFR CIGS WILL BE SLOW TO CLEAR. ALSO SOME PATCHY FOG IN THE SAME AREA WITH A FEW LOCATIONS. FOG WILL SLOWLY LIFT THIS MORNING. FARTHER WEST MAINLY VFR CIGS EXPECTED. LOWER CIGS TO MOVE INTO THE FAR NW LATE AFTERNOON/EVENING AS NEXT WAVE DROPS SE. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ UPDATE...DK SHORT TERM...VOELKER LONG TERM...MAKOWSKI/VOELKER AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1224 PM CST MON FEB 15 2016 .AVIATION... WITH THE COLD FRONT CONTINUING TO MAKE ITS WAY ACROSS SE TX THIS AFTN WE SHOULD BE SEEING THE END OF THE PCPN/CLOUDS FROM THE NW. NO REAL CHANGES WITH FROPA TIMING WITH THE 18Z TAF PACKAGE...NOR WITH THE FCST OF ONSHORE WINDS RETURNING AREAWIDE TOMORROW MORN. WE COULD SEE VERY PATCHY FOG OVERNIGHT AT AIRPORTS CLOSER TO THE COAST...OTHERWISE THIS WILL MAINLY BE A VFR FCST. 41 && .PREV DISCUSSION... /ISSUED 1027 AM CST MON FEB 15 2016/ MORNING FORECAST UPDATE...OVERALL FORECAST ON TRACK WITH MAINLY SHOWERS ACROSS SE TX. BULK OF THE ACTIVITY HAS BEEN CONFINED TO HOUSTON SOUTHWARD ALONG THE COAST. MOST SHOWER ACTIVITY STRETCHES FROM BAY CITY TO BEAUMONT. THERE MAY BE A FEW EMBEDDED THUNDERSTORMS BUT MOST OF THE THUNDERSTORM ACTIVITY HAS PUSHED EAST INTO LOUISIANA. SFC ANALYSIS AT 16Z HAS COLD FRONT ON THE DOOR STEP OF CROCKETT TO CALDWELL. EXPECT FRONT TO PUSH THROUGH WITH NOT MUCH SHOWER OR THUNDERSTORM ACTIVITY. UPDATED FORECAST ON LATEST RADAR TRENDS AND LATEST HRRR SHORT RANGE DATA THAT SEEMS TO BE DOING OKAY WITH EVOLUTION. IT HAS BEEN OVER DOING SHOWER ACTIVITY FOR TODAY. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 72 47 77 49 76 / 10 0 0 0 0 HOUSTON (IAH) 76 50 77 49 75 / 20 0 0 0 0 GALVESTON (GLS) 70 56 71 56 68 / 30 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1135 AM CST MON FEB 15 2016 .AVIATION... THE COLD FRONT HAS MOVED THROUGH ALL THE TERMINALS AND SKIES HAVE CLEARED. WINDS HAVE SHIFTED TO THE NORTH. NORTH WINDS WILL CONTINUE THROUGH THE AFTERNOON AT 10 TO 15 KTS. PREVIOUS TAFS HAD HIGHER GUSTS...BUT SO FAR WINDS BEHIND THE FRONT HAVE NOT BEEN GUSTY SO HAVE TAKEN OUT GUSTS. HOWEVER...WITH ADDITIONAL HEATING HIGHER GUSTS ARE POSSIBLE THIS AFTERNOON. CIGS WILL BE MAINLY CLEAR THROUGH THIS PERIOD. WINDS WILL SHIFT TO THE SOUTHWEST TUESDAY MORNING. && .PREV DISCUSSION... /ISSUED 402 AM CST MON FIB 15 2016/ SHORT TERM (TODAY THROUGH TUESDAY)... MAIN HIGHLIGHTS FOR THE NEXT 36 HOURS WILL FOCUS ON THE MORNING FOG AND LOW CLOUDS ALONG WITH THE PASSAGE OF A WEAK BOUNDARY BEFORE NOON TODAY. SOME ELEVATED FIRE WEATHER CONDITIONS WILL BE LIKELY IN THE RIO GRANDE PLAINS THIS AFTERNOON. ABOVE NORMAL HIGHS ARE EXPECTED TODAY AND TUESDAY. WATER VAPOR AND RAP ANALYSIS DEPICT A STRONGER H5 SHORTWAVE TROUGH PIVOTING ACROSS THE SOUTHERN PLAINS THIS MORNING THAT IS AIDING SOME LIGHT SHOWER DEVELOPMENT ACROSS NE TEXAS. AS EXPECTED...THE STRONGER LIFT REMAINS FARTHER NORTHEAST AND ALONG WITH PWATS ONLY 0.7" OR LESS - HAS RESULTED IN LITTLE TO NO RAIN SHOWERS FOR SOUTH- CENTRAL TEXAS. MOISTURE HAS POOLED ACROSS THE REGION AHEAD OF THE FRONT THAT IS NOW LOCATED ALONG A DALLAS TO WACO TO OZONA LINE. LOW CLOUDS AND AREAS OF FOG WILL OCCUR NOW THROUGH 8-10AM WITH SOME POCKETS OF DENSE FOG POSSIBLE ALONG WITH DRIZZLE/MIST WHERE THE FOG/LOW CLOUDS ARE THICKER NEAR THE SURFACE. THE WEAK BOUNDARY WILL SWEEP THROUGH THE HILL COUNTRY AND AUSTIN BY 7-9AM AND THROUGH SAN ANTONIO BEFORE 11AM. RAPID CLEARING OF CLOUDS IS EXPECTED BEHIND THE BOUNDARY WITH SUNNY CONDITIONS AND BREEZY NORTH WINDS EXPECTED THIS AFTERNOON. THE COMBINATION OF WINDS GUSTING TO NEAR 20-25 MPH AND THE DRIER AIR MOVING IN WILL PROMOTE ELEVATED FIRE WEATHER CONDITIONS ACROSS THE RIO GRANDE PLAINS AS RELATIVE HUMIDITY VALUES DIP NEAR TO JUST BELOW 20% THIS AFTERNOON. FOR TUESDAY...A SLIGHTLY COOLER MORNING IS EXPECTED GIVEN THE DRIER AIR AND NEAR CALM WINDS BUT READINGS WILL BE NEAR CLIMATE NORMALS. EXPECTED CLEAR SKIES WITH PLENTY OF SUN WITH HIGHS REACHING ABOVE NORMAL INTO THE UPPER 70S AND LOW 80S. SOME LOCATIONS IN THE RIO GRANDE PLAINS COULD REACH INTO THE MID 80S. LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)... WELL ABOVE NORMAL TEMPERATURES OF 10-15F DEGREES ARE EXPECTED MID TO LATE WEEK WITH A SLIGHT COOL DOWN INTO THE WEEKEND. DRY CONDITIONS WILL ALSO REMAIN UNTIL EARLY NEXT WEEK WHERE A MORE SUBSTANTIAL COLD FRONT AND BETTER RAIN CHANCES COULD OCCUR. CONUS PATTERN MID TO LATE WEEK WILL FEATURE SURFACE HIGH PRESSURE OVER THE MID-MS RIVER VALLEY WITH SOUTHEAST LOW-LVL FLOW THAT VEERS TO THE SOUTHWEST/WEST IN THE MID-LVL OVER TEXAS. THIS TYPE OF PATTERN ALONG WITH A BUILDING H5 RIDGE AND H925 TEMPS 23-16C FROM WEST TO EAST WILL SUPPORT UPPER 70S TO MID 80S. WHILE IT WILL BE WARM...RECORD TEMPERATURES DO NOT LOOK TO BE IN JEOPARDY AS THOSE VALUES ARE ALREADY WELL INTO THE 90S. MORNING CLOUDS LOOK TO RETURN THURSDAY AND FRIDAY BUT QUICK MIX OUTS BY MID MORNING HOURS TO PARTLY AND MOSTLY SUNNY SKIES WILL OCCUR. SLIGHTLY COOLER H925 AIR WILL PIVOT IN ACROSS THE REGION THIS WEEKEND AS THE H5 RIDGE BREAKS DOWN AND SOME WEAK IMPULSES MIGRATE OVER THE REGION THAT WILL CREATE SOME MORE MID-LVL CLOUDS. GLOBAL LONG RANGE MODELS CONTINUE TO HINT AT IN DECENT ACCORD A MORE ACTIVE SOUTHERN JET STREAK BRANCH OVER SOUTH TEXAS NEXT SUNDAY- TUESDAY. THIS ACTIVE BRANCH WILL HELP BUCKLE THE FLOW WITH ENHANCED TROUGHING THAT, IN CONJUNCTION WITH THE POLAR JET, WILL AID A STRONGER CANADIAN ORIGINATED FRONT TO APPROACH THE AREA AROUND MONDAY. THIS STRONGER FRONT AND BETTER DYNAMIC SUPPORT SHOULD ALLOW FOR BETTER RAIN/STORM CHANCES IN THIS TIME FRAME. WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM AND ITS LIKELY MORE WIDESPREAD RAIN SIGNAL FOR THE REGION. && .PRELIMINARY POINT TEMPS/POPS... AUSTIN CAMP MABRY 75 47 81 50 82 / 10 0 0 0 0 AUSTIN BERGSTROM INTL AIRPORT 75 43 80 45 81 / 10 0 0 0 0 NEW BRAUNFELS MUNI AIRPORT 77 44 81 47 81 / - 0 0 0 0 BURNET MUNI AIRPORT 73 44 79 46 80 / - 0 0 0 0 DEL RIO INTL AIRPORT 80 46 85 51 87 / 0 0 0 0 0 GEORGETOWN MUNI AIRPORT 73 44 80 46 80 / 10 0 0 0 0 HONDO MUNI AIRPORT 80 42 82 46 83 / 0 0 0 0 0 SAN MARCOS MUNI AIRPORT 76 44 79 46 79 / - 0 0 0 0 LA GRANGE - FAYETTE REGIONAL 76 46 79 47 80 / 10 0 0 0 0 SAN ANTONIO INTL AIRPORT 77 46 80 49 82 / 0 0 0 0 0 STINSON MUNI AIRPORT 79 46 82 48 82 / 0 0 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ MESOSCALE/AVIATION...05 SYNOPTIC/GRIDS...RUNYEN PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1118 AM CST MON FEB 15 2016 .AVIATION... NO AVIATION WEATHER CONCERNS FOR THE NEXT 24 HOURS. SURFACE WINDS WILL SWING FROM NORTH TO SOUTHWEST TODAY THEN BACK TO THE NORTH TUESDAY MORNING AS A FRONT MOVES THROUGH. NORTH-NORTHEAST WINDS WILL BECOME BREEZY WITH THE FROPA BY LATE TUESDAY MORNING. && .PREV DISCUSSION... /ISSUED 440 AM CST MON FEB 15 2016/ AVIATION... VFR. LIGHT NW WINDS BECMG SWLY AROUND 11 KNOTS BY MIDDAY. PREV DISCUSSION... /ISSUED 339 AM CST MON FEB 15 2016/ SHORT TERM... IN THE WAKE OF A MINOR TROUGH THAT MANAGED TO GENERATE MID-LEVEL CLOUDS AND VIRGA OVER OVER THE SERN PANHANDLE LAST NIGHT...BROAD SURFACE RIDGING CENTERED IN NERN NM WILL TRANSLATE SEWD UNDER DRY NW FLOW. DEPARTURE OF THIS RIDGE BY LATE MORNING AND SUBSEQUENT DOWNSLOPE FLOW WILL AID IN LEE TROUGH DEVELOPMENT OVER EASTERN NM COMPLETE WITH SOME BREEZY W-SW WINDS LOCALLY. CONTINUE TO SIDE WITH THE DRIER RUC AND HRRR FOR AFTERNOON DEWPOINTS AS REMAINING GUIDANCE HAS BEEN TOO GENEROUS WITH THESE IN RECENT DAYS...IF NOT WEEKS. UPSHOT OF THIS IS THAT MILDER MAV HIGH TEMPS REMAIN FAVORED OVER THE COOL SUPERBLEND. SW WINDS TONIGHT WILL VEER W-NW BEFORE DAYBREAK TUE IN ADVANCE OF A DECAYING COLD FRONT AND DISTANT TROUGH TRACKING ALONG THE MIDDLE MISSOURI RIVER VALLEY. LONG TERM... QUIET WEATHER WILL CONTINUE THROUGH MUCH OF THE WEEK AS DRY NORTHWEST FLOW GRADUALLY TRANSITIONS TO SOUTHWESTERLY/ZONAL BY THE END OF THE WEEK. A WEAK FRONT WILL PUSH THROUGH EARLY TUESDAY KEEPING TEMPERATURES IN THE MID 60S TO LOW 70S FOR HIGHS AND LOWS IN THE MID 30S TO LOWER 40S. RIDGE WILL MOVE OVER THE REGION ON WEDNESDAY WHICH WILL START WARMING TEMPERATURES WELL ABOVE NORMAL FOR MID-WEEK. WARMEST DAY STILL LOOKS TO BE THURSDAY WHEN SOUTHWESTERLY FLOW WILL DEVELOP AT THE SURFACE HELPING TO BOOST HIGHS INTO THE LOW 80S. WEAK SOUTHWESTERLY FLOW ALOFT WILL REMAIN IN PLACE FRIDAY THROUGH THE END OF THE FORECAST. THIS WILL KEEP BOUNDARY LAYER MOISTURE IN PLACE EITHER OVER OR NEAR THE FORECAST AREA THROUGH SOME POINT OVER THE WEEKEND OR FIRST PART OF NEXT WEEK. THERE CONTINUES TO BE DIFFERENCES BETWEEN THE GFS AND ECMWF WITH THE ARRIVAL OF A COLD FRONT AT THE END OF THE UPCOMING WEEKEND OR FIRST PART OF NEXT WEEK. DIFFERENCES SURROUND THE STRENGTH OF A WAVE/CLOSED LOW THAT SWINGS OUT ACROSS THE NORTHERN PLAINS OVER THE GREAT LAKES. ECMWF DEVELOPS A CLOSED LOW RESULTING IN A STRONGER FRONT THAT PUSHES THROUGH ON SUNDAY WHILE THE GFS IS MUCH WEAKER THAN THE ECMWF. MODELS TRY TO BREAK OUT PRECIPITATION IN VARYING AMOUNTS AND COVERAGE AND SUPERBLEND OUTPUT CONTINUES TO CARRY POPS FOR SATURDAY INTO SUNDAY. BECAUSE OF THE DIFFERENCES IN THE MODELS... ECMWF IS MUCH DRIER THAN THE GFS...WILL KEEP POPS OUT OF THE FORECAST FOR NOW UNTIL WE SEE IF THE EXTENDED RANGE FORECAST CAN COME INTO BETTER CONSENSUS. JORDAN && .LUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ 33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1027 AM CST MON FEB 15 2016 .DISCUSSION... MORNING FORECAST UPDATE...OVERALL FORECAST ON TRACK WITH MAINLY SHOWERS ACROSS SE TX. BULK OF THE ACTIVITY HAS BEEN CONFINED TO HOUSTON SOUTHWARD ALONG THE COAST. MOST SHOWER ACTIVITY STRETCHES FROM BAY CITY TO BEAUMONT. THERE MAY BE A FEW EMBEDDED THUNDERSTORMS BUT MOST OF THE THUNDERSTORM ACTIVITY HAS PUSHED EAST INTO LOUISIANA. SFC ANALYSIS AT 16Z HAS COLD FRONT ON THE DOOR STEP OF CROCKETT TO CALDWELL. EXPECT FRONT TO PUSH THROUGH WITH NOT MUCH SHOWER OR THUNDERSTORM ACTIVITY. UPDATED FORECAST ON LATEST RADAR TRENDS AND LATEST HRRR SHORT RANGE DATA THAT SEEMS TO BE DOING OKAY WITH EVOLUTION. IT HAS BEEN OVER DOING SHOWER ACTIVITY FOR TODAY. 39 && .PRELIMINARY POINT TEMPS/POPS... COLLEGE STATION (CLL) 72 47 77 49 76 / 10 0 0 0 0 HOUSTON (IAH) 76 50 77 49 75 / 20 0 0 0 0 GALVESTON (GLS) 70 56 71 56 68 / 30 10 0 0 0 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ DISCUSSION...39
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
352 PM EST MON FEB 15 2016 .SYNOPSIS... HIGH PRESSURE WEDGING DOWN THE EAST SLOPES OF THE APPALACHIANS WILL SLOWLY MOVE NORTHEAST TONIGHT...AS LOW PRESSURE MOVES FROM THE LOWER MISSISSIPPI VALLEY TO THE MID ATLANTIC STATES. ANOTHER LOW WILL TRACK OUT OF SOUTHERN CANADA TONIGHT INTO THE TENNESSEE VALLEY BY LATE TUESDAY. && .NEAR TERM /THROUGH TUESDAY/... AS 352 PM EST MONDAY... WINTER STORM WARNING REMAINS IN EFFECT UNTIL NOON TUESDAY FOR ENTIRE AREA. THE 18Z RNK SOUNDING SHOWED THE WARM LAYER AROUND 3KFT...WHILE THE TEMPERATURE AT SURFACE AT BCB WAS BELOW FREEZING. LIGHT SURFACE WINDS BECOME SOUTHWEST ALOFT. THIS COLD AIR DAMMING AGAINST THE APPALACHIANS WILL MAINTAIN A WEDGE OF SUB-FREEZING NEAR SURFACE THROUGH THE EVENING AND INTO TONIGHT. THE WINTRY MIXTURE OF SNOW...SLEET...FREEZING RAIN AND RAIN WILL CONTINUE TONIGHT. LOW PRESSURE WILL MOVE FROM THE TENNESSEE VALLEY TO THE CENTRAL APPALACHIANS TONIGHT AND NORTHWARD INTO PENNSYSLVANIA BY 18Z TUESDAY. THE COLD AIR WILL HOLD THE LONGEST ACROSS THE NORTH ESPECIALLY ALLEGHANY HIGHLANDS INTO TUESDAY MORNING. SHORTWAVE COMING OUT OF THE SOUTHERN PLAINS CROSSES THE TUESDAY WITH A MIXTURE OF RAIN AND SNOW IN THE WESTERN HIGHER ELEVATIONS. FOR POPS THIS EVENING LEANED TOWARDS THE HRRR SOLUTION WHICH CAPTURED THE DRIER SLOT AND MIXED PRECIPITATION THE BEST. THEN...SHAPED POPS TOWARDS THE NAM FOR LATE TONIGHT INTO TUESDAY MORNING. USED THE TOPDOWN FOR PTYPE WITH NAM AS PRIMARY TEMPERATURE PROFILE TONIGHT INTO TUESDAY. HYDROLOGY SECTION CREATED TO HIGHLIGHT THE TRANSITION FROM A WINTER EVENT TO POTENTIAL FOR HYDRO EVENT. THE VERY STRONG JET IN ADDITION TO ADVECTING IN WARMER TEMPERATURES ALOFT WILL BRING PRECIPITABLE WATER VALUES JUST ABOVE ONE INCH INTO THE FORECAST AREA. HIGHEST LIQUID PRECIPITATION AMOUNTS WILL BE OVERNIGHT INTO TUESDAY MORNING AIDED BY THE VERY STRONG LOW LEVEL JET. WILL CONTINUE HIGHLIGHT THE STRONG WINDS AT HIGHER ELEVATIONS AND IN THE FAVORED DOWNSLOPE AREAS FROM BLUEFIELD TO TAZEWELL WITHIN THE WINTER STORM WARNING. THE COMBINATION OF SNOWMELT...CHALLENGING QPF FORECAST AND PLACEMENT OF AXIS OF HEAVIER RAIN MAKE THE FLOOD POTENTIAL TRICKY. WITH SNOW MELT...SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY ON THE DAN AND LOWER ROANOKE. WILL ADD THE MENTION OF FLOOD POTENTIAL TO THE HWO. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... AS OF 245 PM EST MONDAY ON THE HEEL`S OF MONDAY`S STORM WILL BE A CLIPPER THAT WILL DIVE SOUTH ACROSS THE SOUTHERN OHIO-TENNESSEE VALLEYS TUESDAY EVENING. TEMPERATURES SHOULD REMAIN WARM ENOUGH TO START OUT AS A LIGHT RAIN...THEN TRANSITION TO UPSLOPE SNOW SHOWERS BY WEDNESDAY MORNING. COMING QUICKLY BEHIND THE STRONGER SYSTEM...THIS CLIPPER SHOULD NOT BRING ANY ADDITIONAL THREATS OF FLOODING NOR SIGNIFICANT SNOWFALL. UPSLOPES SNOW SHOWERS DURING THE DAY WEDNESDAY COULD BE WHITE RAIN AS TEMPERATURES WARM OR REMAIN IN THE LOW TO MID 30S. MOUNTAIN TEMPERATURES MAY BE COLD ENOUGH ABOVE 3000 FT FOR SOME LIGHT SNOW ACCUMULATIONS...POSSIBLY UP TO 3 INCHES OVER A 36 HOUR PERIOD. 85H WINDS TURN QUICKLY OUT OF THE WEST TO END PRECIPITATION CHANCES BY SUNRISE WEDNESDAY MORNING ALONG AND EAST OF THE BLUE RIDGE BY SUNRISE WEDNESDAY MORNING. WINDS WILL BE BREEZY AND GUSTY AT TIMES THROUGH THE PERIOD BUT ARE NOT EXPECTED TO REACH ADVISORY CRITERIA. WE WILL HAVE MODERATE PRESSURE RISES AND COLD AIR ADVECTION WHILE THE 85H CROSS-BARRIER JET STAYS UNDER 30 KTS. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 315 PM EST MONDAY RESIDUAL 500 MB TROUGH WILL FINALLY LIFT OUT TO THE NORTHEAST ON THURSDAY AS HEIGHTS START TO BUILD FROM THE WEST AHEAD OF A RATHER POTENT SHORTWAVE AND ASSOCIATED SURFACE LOW THAT WILL BE CROSSING THE GREAT LAKES ON FRIDAY. THIS SHOULD BOOT A SURFACE WARM FRONT THROUGH THE REGION FRIDAY AFTERNOON AS THE LINGERING WEDGE OF SURFACE HIGH PRESSURE TO THE NORTH REPOSITIONS OFF THE CAROLINAS BY LATE FRIDAY. RAPID JUMP IN 85H TEMPERATURES UNDER THE DEVELOPING SHORTWAVE RIDGE LOOKS TO PUSH HIGHS TO JUST ABOVE NORMAL AFTER REMAINING COOL THURSDAY UNDER THE CANADIAN HIGH TO THE NORTH. HOWEVER GIVEN SOME LINGERING SNOW PACK AND EVOLVING TRANSITION OF THE SURFACE HIGH...WILL STAY A BIT BELOW MOS FRIDAY ESPECIALLY EAST. OTHERWISE DRY BUT STILL ON THE COLD SIDE THURSDAY NIGHT THEN WARMER FRIDAY. MAJORITY OF THE NORTHERN STREAM ENERGY WILL PASS TO THE NORTH TO START THE WEEKEND WHILE ALLOWING ITS TRAILING TROUGH AXIS TO FLATTEN THE ONGOING MID LEVEL RIDGING TO SOME DEGREE. THE ASSOCIATED WEAK COLD FRONT SHOULD PRESS ACROSS THE REGION SATURDAY BUT GIVEN VERY LIMITED MOISTURE...AND MOST COLD ADVECTION TO THE NORTH APPEARS ONLY A FEW RAIN SHOWERS POSSIBLE MAINLY FAR WEST. WITH COOL AIR LIKELY TO LAG THE FRONT AND LESS CLOUDS HEADING EAST OF THE MOUNTAINS...WOULD EXPECT TEMPS TO REALLY JUMP UNDER WESTERLY FLOW WITH HIGHS WELL ABOVE NORMAL...MAINLY 50S WEST TO 60S EAST. WEAK BUBBLE HIGH WILL FOLLOW THIS WEAK FRONT ON SUNDAY WITH SKIES CLEARING BEFORE RETURN MOISTURE STARTS TO RETURN LATER IN THE DAY AHEAD OF THE NEXT UPSTREAM TROUGHS. TIMING OF THIS MOISTURE ALONG WITH POTENTIAL FOR A SOUTHERN STREAM WAVE TO PERHAPS SLOW UP THE NEXT FRONT....PER THE EARLIER EC...SUPPORTS MAINLY DRY AND CONTINUED MILD SUNDAY. SLOW RETURN TO EASTERN TROFFINESS APPEARS TO BE IN ORDER BY EARLY NEXT WEEK WITH THIS NEXT FRONT SLIDING ACROSS PRODUCING THE NEED FOR LOW RAIN SHOWER POPS AND SLIGHTLY COOLER TEMPS BUT STILL OVERALL A BIT ABOVE NORMAL FOR DAY 7. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... AS OF 1251 PM EST MONDAY... POOR FLYING CONDITIONS WILL CONTINUE DURING THE TAF PERIOD WITH A WINTRY MIXTURE OF SNOW...SLEET...FREEZING RAIN AND RAIN ALONG WITH WINDS AND LOW CLOUDS. IFR/LIFR CONDITIONS WILL PREVAIL THIS AFTERNOON INTO TONIGHT. WINTRY MIX OF SNOW...SLEET AND FREEZING RAIN WILL TRANSITION TO RAIN OVERNIGHT. WARMER AIR OVERRIDING THE COLD AIR WILL INCREASE TONIGHT AND SHOULD CHANGE MOST LOCATIONS TO PLAN RAIN TONIGHT. SOME COLDER AIR MAY WORK INTO THE MTNS BY 12Z TUESDAY WITH POSSIBLE LIGHT SNOW/FREEZING RAIN POSSIBLE AT KLWB. ANOTHER ISSUE LATE TONIGHT WILL BE WINDS...AS MODELS SHOW A VERY STRONG LOW LVL JET MOVING ACROSS THE CENTRAL APPALACHIANS. LOW LVL WIND SHEAR MAY BE POSSIBLE OVER THE MOUNTAIN TERMINALS...SOME GUSTS REACHING SFC AT KBLF WITH OVER 20 KTS POSSIBLE. MAY NEED TO ADD LLWS TO TAFS LATER THIS EVENING OR TONIGHT. THE WINTER STORM IS EXPECTED TO MOVE NORTHEAST AND AWAY FROM THE AREA TUESDAY. SOME DRIER AIR WILL PUSH IN ON TUESDAY WITH SCATTERED RAIN AND SNOW POCKETS POSSIBLE IN THE WEST. LOW TO MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE TAF PERIOD. EXTENDED DISCUSSION... A CLIPPER SYSTEM MAY IMPACT THE AREA TUESDAY NIGHT AND WEDNESDAY...POSSIBLY RESULTING IN THE CONTINUATION OF POOR FLYING CONDITIONS. HIGH PRESSURE BUILDS IN THURSDAY WITH VFR RETURNING FOR THE SECOND HALF OF THE WEEK. && .HYDROLOGY... AS OF 245 PM EST MONDAY TRANSITION FROM A WINTER EVENT TO POTENTIAL FOR HYDRO EVENT CONTINUES TO BE ONE OF THE ISSUES ON THE TABLE THIS AFTERNOON. ACCUMULATING SNOW WINDING DOWN ACROSS THE CWA AS THE WARM NOSE WORKS FURTHER NORTH. WIDESPREAD 5 TO 10 INCHES OF SNOW WAS OBSERVED WITH THE EXCEPTION OF SOUTHEAST PIEDMONT COUNTIES WITH 2 TO 4 INCHES. WITH SNOW-LIQUID RATIOS RUNNING CLOSE TO 10:1 WE HAVE A SOLID 0.50 TO 1 INCH OF SNOW WATER EQUIVALENT ON THE GROUND. FREEZING RAIN AND SLEET WILL BE THE PREDOMINANT P-TYPE GOING FORWARD BUT WITH A SIGNIFICANT WARMING TREND OVERNIGHT...PRECIPITATION CHANGES TO ALL LIQUID FROM SOUTHWEST TO NORTHEAST DURING THAT PERIOD. BASICALLY FOLLOWED WPC QPF NEXT 24 HOURS... WHICH IS RUNNING IN THE 1.00 TO 1.75 INCH RANGE CWA-WIDE THROUGH TOMORROW EVENING WITH THE BULK CONCENTRATED IN THE 06-12Z RANGE WITH UP TO AN INCH IN THAT 6-HOURS. NORMALLY THIS AMOUNT WOULD BE SUFFICIENT FOR SOME FLOODING BOTH SHORT-FUSE (FLASH) AND LONG-FUSE (RIVERS). BUT THE EXISTING SNOWPACK IS A BIG COMPLICATING FACTOR. IT WILL ABSORB QUITE A BIT OF RAIN AND DEPENDING ON THE EXACT TEMPERATURE/DEWPOINT REGIME IT COULD BE THAT MOST IS ABSORBED...WITH ONLY LIMITED RUNOFF OVER THE NEXT 24-36 HOURS. HENCE...AFTER COORDINATING WITH SURROUNDING WFOS HAVE OPTED TO NOT ISSUE ANY TYPE OF FLOOD WATCH FOR THE CWA. CAME CLOSEST OVER THE NORTHEAST COUNTIES BUCKINGHAM/APPOMATTOX/AMHERST WHERE THE COMBINATION OF FUTURE RAINFALL/SNOWMELT APPEARS TO BE MAXIMIZED...ALTHOUGH FAR SOUTHWEST WAS ALSO CONSIDERED VULNERABLE TO THE SAME COMBINATION ALTHOUGH IN DIFFERENT DOSAGES. ONCE IT ALL MELTS SOME RIVER FLOODING SEEMS VERY LIKELY..ESPECIALLY ON THE DAN AND LOWER ROANOKE. VARIOUS ENSEMBLE RIVER FORECAST GUIDANCE SHOWS UP TO A 70 PERCENT CHANCE OF MINOR FLOODING ON THE LOWER DAN AND MORE LIKE 30 PERCENT ALONG PARTS OF THE JAMES RIVER WITHIN A FEW DAYS. ALTHOUGH THE SIGNAL FOR WIDESPREAD FLOODING REMAINS AMBIGUOUS...WILL HAVE TO WATCH CLOSELY EVOLVING QPF FORECASTS AND THE OBSERVED AND MODELED RATE OF SNOWMELT. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR VAZ007-009>020- 022>024-032>035-043>047-058-059. NC...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR NCZ001>006- 018>020. WV...WINTER STORM WARNING UNTIL NOON EST TUESDAY FOR WVZ042>044-507- 508. && $$ SYNOPSIS...AMS NEAR TERM...KK SHORT TERM...RCS LONG TERM...JH/RCS AVIATION...KK/WP HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
322 PM CST MON FEB 15 2016 .SHORT TERM...(THIS EVENING THROUGH TUESDAY) ISSUED AT 322 PM CST MON FEB 15 2016 PRIMARY CONCERNS INVOLVE FOG AND SNOW CHANCES/AMOUNTS TONIGHT THROUGH TUESDAY. 15.12Z MODEL SUITE IN GOOD OVERALL AGREEMENT AND WILL FOLLOW A BLENDED SOLUTION...ALTHOUGH FOCUS FOR THE NEXT 6 TO 12 HOURS WILL BE ON THE LATEST RAP/HRRR OUTPUT. 15.20Z WATER VAPOR LOOP SHOWS A WEAK SHORT-WAVE MOVING ACROSS CENTRAL MN AND THIS HAS RESULTED IN A COMPACT AREA OF SNOW SHOWERS NOW MOVING INTO SOUTHEAST MN. 15.20Z HRRR SHOWS THESE SHOWERS MOVING EAST INTO THE EARLY EVENING AND THEN FALLING APART NEAR THE MS RIVER. WITH SFC OBS UNDER THIS SNOW REPORTING VISIBILITY FROM 3 TO 5SM...A QUICK DUSTING IS POSSIBLE LATE THIS AFTERNOON/EARLY EVENING. BIGGER CONCERN THIS EVENING IS FOG POTENTIAL. WITH MOIST WARM AIR ADVECTION REGIME OVER THE SNOWPACK AND RELATIVELY LIGHT NEAR SURFACE FLOW...THINK THERE COULD BE A REPEAT FROM THIS MORNING WITH RAPIDLY DEVELOPING FOG AFTER SUNSET. THIS IS ESPECIALLY TRUE IF THE LIMITED CLEARING AREA ACROSS CENTRAL MN CAN WORK ITS WAY INTO THE FORECAST AREA AND ALLOW FOR GREATER NOCTURNAL COOLING. AREAS OF DENSE FOG A REAL POSSIBILITY...BUT TIMING/COVERAGE UNCERTAIN AND SOMETHING TO WATCH THROUGHOUT THE EVENING FOR POSSIBLE ADVISORY CONDITIONS. FOR NOW...WILL EXPAND PATCHY/AREAS OF FOG FROM WEST TO EAST THIS EVENING AND OVERNIGHT. ANY FOG THAT DOES DEVELOP IS NOT LIKELY TO DISSIPATE UNTIL SOMETIME TUESDAY MORNING AT THE EARLIEST. TEMPERATURES TONIGHT WILL BE WARM... GENERALLY IN THE UPPER TEENS TO MID 20S ABOVE ZERO. 15.12Z GLOBAL MODELS NOW IN GOOD AGREEMENT...SHOWING THE NEXT SHORT-WAVE ALOFT FOR TONIGHT DIVING TO THE SOUTH AND WEST OF THE FORECAST AREA. BEST 500 TO 300 HPA POSITIVE VORTICITY ADVECTION AND MID-LEVEL FRONTOGENESIS WITH THIS WAVE IS BETTER ALIGNED ALONG THE MO RIVER VALLEY WHERE A FEW INCHES OF SNOW ARE POSSIBLE. A SECONDARY WEAKER SHORT-WAVE/SURFACE COLD FRONT WILL MOVE ACROSS THE FORECAST AREA LATER TONIGHT THROUGH TUESDAY...BRINGING A CHANCE FOR LIGHT SNOW ACROSS MUCH OF REGION. HOWEVER...LIFT AND MOISTURE ARE RATHER UNIMPRESSIVE. NAM BUFKIT SOUNDINGS IN PARTICULAR LACK ICE FOR MUCH OF THE PERIOD...WHEREAS THE GFS SHOWS A DEEPER SATURATED LAYER. WILL NEED TO WATCH FOR POSSIBLE FREEZING RAIN/DRIZZLE...BUT FOR NOW THINK THE NAM IS UNDER DOING COLDER CLOUDS ALOFT AND WILL KEEP PRECIPITATION TYPE AS SNOW. IF SNOW DOES DEVELOP WITHIN WEAK LIFT REGIME...ACCUMULATIONS WILL GENERALLY BE AN INCH OR LESS REGION-WIDE. TEMPERATURES TUESDAY WILL AGAIN HINGE ON CLOUD COVER...BUT SHOULD RISE INTO THE LOWER 30S MOST AREAS PRIOR TO THE COLD FRONTAL PASSAGE. .LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 322 PM CST MON FEB 15 2016 TUESDAY NIGHT THROUGH THURSDAY LOOK MAINLY DRY AS BROAD SURFACE HIGH PRESSURE DOMINATES THE REGIONAL WEATHER PATTERN. A SLIGHTLY COOLER AIR MASS ON WEDNESDAY IN THE WAKE OF TUESDAY/S COLD FRONT WILL KEEP TEMPERATURES MAINLY IN THE 20S. HOWEVER...A MUCH DRIER AIR MASS SHOULD LEND ITSELF TO SOME SUNSHINE FOR AT LEAST THE LATTER HALF OF THE DAY. SIGNIFICANT WARM AIR ADVECTION ENSUES AFTER 06Z THURSDAY SO THAT BY 06Z FRIDAY...925 HPA TEMPERATURES RANGE FROM +3 TO +7 CELSIUS. ALTHOUGH DEPENDENT ON CLOUD COVER... TEMPERATURES THURSDAY SHOULD CLIMB INTO THE MID TO UPPER 30S. ATTENTION THEN TURNS TO THURSDAY NIGHT INTO FRIDAY AS THE NEXT PACIFIC TROUGH LIFTS INTO THE UPPER MIDWEST. 15.12Z GFS/ECMWF ARE IN BETTER AGREEMENT WITH THIS SYSTEM...ALTHOUGH THE GFS SURFACE LOW TRACK IS A BIT FURTHER NORTH. THE GFS IS ALSO MORE BULLISH ON QPF MAINLY THURSDAY NIGHT IN THE SYSTEM/S WARM SECTOR. STILL NEED TO WATCH POTENTIAL FOR SOME MIXED FREEZING PRECIPITATION THURSDAY NIGHT FOR AREAS NORTH OF I-94 THAT HAVE SUB-FREEZING SURFACE TEMPERATURES. DEGREE OF WARMTH ON FRIDAY A BIT MORE UNCERTAIN NOW AS BOTH MODELS ALIGN THE SURFACE COLD FRONT ALONG THE MS RIVER BY 12Z FRIDAY. HOWEVER...OVERALL POST-FRONTAL THERMAL PROFILE REMAINS WARM ENOUGH SO THAT PRECIPITATION FALLS AS RAIN. FOR NOW...EXPECT TEMPERATURES INTO THE 40S WITH CONSENSUS 30 TO 60 POPS. A DRY AND WARM SATURDAY GIVES WAY TO ANOTHER SHOT OF PRECIPITATION SUNDAY AS A SHORT-WAVE DROPS SOUTH FROM CANADA. TOO FAR OUT TO PROVIDE MANY DETAILS...BUT PRECIPITATION TYPE SHOULD BE MAINLY LIQUID. MONDAY DRIES OUT AND COOLS BACK DOWN ON THE BACKSIDE OF DEPARTING WAVE. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY NOON) ISSUED AT 1128 AM CST MON FEB 15 2016 WARMING AND MOISTENING SOUTHERLY FLOW WILL CONTINUE ACROSS THE AREA THIS AFTERNOON INTO TUE MORNING. THIS AHEAD OF YET ANOTHER WEAK NORTHWEST FLOW SYSTEM DROPPING ACROSS THE REGION. MVFR/IFR CIGS/VSBYS IN BR/LOW STRATUS...MORE IFR AT SITES LIKE KRST AND MORE MVFR AT VALLEY SITES LIKE KLSE...HAVE ALREADY SPREAD ACROSS THE AREA. SOME MINOR IMPROVEMENTS THRU THIS AFTERNOON...BUT WITH APPROACH OF ANOTHER LOW AND THE SOUTHERLY FLOW...CIGS/VSBYS EXPECTED TO DROP TONIGHT AS MOISTURE IS CONTINUALLY PULLED NORTH OVER THE COLD SNOW-COVERED GROUND. TRENDED KRST LIFR FOR MUCH OF THE 06Z-15Z PERIOD AND KLSE TO IFR. CONDITIONS TO SLOWLY IMPROVE LATE TUE MORNING AS THE LOW/TROUGH AXIS WOULD PASS AND PERHAPS SOME LIGHT SNOW WOULD FALL TO HELP REDUCE/DISSIPATE THE FOG. EITHER WAY...MUCH OF THE NEXT 24 HRS SHAPING UP TO BE AN IFR PERIOD AT BOTH TAF SITES. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ SHORT TERM...ROGERS LONG TERM...ROGERS AVIATION.....RRS