Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 02/28/14
AREA FORECAST DISCUSSION
NWS SAN JOAQUIN VALLEY - HANFORD CA
920 AM PST WED FEB 26 2014
.UPDATE...
LOWERED TEMPERATURES FOR TODAY.
&&
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN WILL CONTINUE. RAIN AND HIGHER
ELEVATION SNOW ARE EXPECTED AT TIMES THROUGH AT LEAST THE
WEEKEND. THE NEXT SYSTEM WILL MOVE INTO THE AREA ON FRIDAY AND
SATURDAY WITH BETTER CHANCES OF PRECIPITATION ACROSS THE REGION
AND EVEN A FEW THUNDERSTORMS.
&&
.DISCUSSION...
INCREASING CLOUDS WILL REDUCE HEATING TODAY. RAIN HAS REACHED
SOUTH BAKERSFIELD AT THIS TIME...AND THE RAIN WILL SUPPRESS THE
SOUTHERLY SURFACE FLOW. TEMPERATURES HAVE BEEN LOWERED OVER THE
REGION AND ARE NOW CLOSER TO 12Z GUIDANCE. POPS HAVE BEEN RAISED
FOR THE SOUTH END OF THE SAN JOAQUIN VALLEY DUE TO EARLIER ARRIVAL
OF PRECIPITATION.
&&
.AVIATION...
INCREASING CLOUDS WITH GRADUALLY LOWERING CEILINGS...AREAS OF MVFR
AND LOCAL IFR CONDITIONS DEVELOPING IN PRECIPITATION SPREADING IN
FROM THE WEST AFTER 18Z WEDNESDAY ACROSS THE CENTRAL CA INTERIOR.
&&
.PREV DISC... /ISSUED 846 AM PST WED FEB 26 2014/
DISCUSSION...125 KT JET THAT IS UNDERCUTTING OFFSHORE STORM IS
PUSHING COLD FRONT AND ASSOCIATED RAIN BAND MORE QUICKLY EASTWARD
THAN ORIGINALLY ANTICIPATED. THE GFS AND HRRR MODELS SEEM TO HAVE
A MUCH BETTER HANDLE ON THIS SO WILL USE THESE SOLUTIONS FOR GUIDANCE.
ALTHO SW WINDS HAVE DIMINISHED SOMEWHAT ON THE WEST SIDE OF THE SJ
VLY...THERE WILL BE LOCAL GUSTS TO 40 MPH FOR THE NEXT HR OR SO.
HOWEVER...THE ONSET OF RAIN WILL STABILIZE WINDS IN THIS PORTION
OF THE CWA TODAY. REMAINDER OF FORECAST LOOKS ON TRACK.
&&
.AIR QUALITY ISSUES...
NONE.
&&
.CERTAINTY...
THE LEVEL OF CERTAINTY FOR DAYS 1 AND 2 IS HIGH.
THE LEVEL OF CERTAINTY FOR DAYS 3 THROUGH 7 IS MEDIUM.
THIS INFORMATION IS PROVIDED AS PART OF A TRIAL PROJECT CONDUCTED
BY THE NATIONAL WEATHER SERVICE SAN JOAQUIN VALLEY - HANFORD.
CERTAINTY LEVELS INCLUDE LOW...MEDIUM...AND HIGH. PLEASE VISIT
WWW.WEATHER.GOV/HNX/CERTAINTY.PHP /ALL LOWER CASE/ FOR ADDITIONAL
INFORMATION AND/OR TO PROVIDE FEEDBACK.
&&
.CLIMATE...
RECORDS
SITE DATE HI_MAX:YEAR LO_MAX:YEAR HI_MIN:YEAR LO_MIN:YEAR
KFAT 02-26 83:1888 44:1962 53:1995 25:1971
KFAT 02-27 79:1992 45:1996 54:2006 26:1962
KFAT 02-28 79:1926 51:1971 59:1986 28:1962
KBFL 02-26 80:1992 43:1962 56:1968 30:1971
KBFL 02-27 83:1980 46:1962 58:1988 24:1893
KBFL 02-28 81:1926 49:1945 56:1968 22:1893
&&
.HNX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 PM PST THURSDAY ABOVE 7000 FEET
FOR THE SOUTHERN SIERRA NEVADA FROM YOSEMITE TO THE KERN COUNTY
LINE /CAZ096-097/.
WINTER STORM WATCH FROM LATE THURSDAY NIGHT THROUGH LATE
SATURDAY NIGHT ABOVE 6000 FEET FOR THE SOUTHERN SIERRA NEVADA FROM
YOSEMITE TO THE KERN COUNTY LINE /CAZ096-097/.
HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY AFTERNOON FOR
THE KERN COUNTY MOUNTAINS...MAINLY NEAR THE GRAPEVINE /CAZ095/.
WIND ADVISORY UNTIL NOON PST TODAY FOR THE WEST SIDE OF THE SAN
JOAQUIN VALLEY /CAZ089-091/.
&&
$$
PUBLIC...SANGER
AVN/FW...DURFEE
PREV DISCUSSION...DURFEE
SYNOPSIS...BSO
WEATHER.GOV/HANFORD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1000 PM MST TUE FEB 25 2014
.UPDATE...
ISSUED AT 803 PM MST TUE FEB 25 2014
SNOTELS IN THE NORTHERN MOUNTAINS INDICATED ACCUMULATIONS HAD
ENDED AT MOST LOCATIONS AND ONLY BUFFALO PARK HAD PICKED UP ANY
MEASURABLE ACCUMULATION IN THE PAST COUPLE OF HOURS. SATELLITE
INDICATED THAT THE TROUGH AXIS HAD EXITED THE ADVISORY AREA.
CONSEQUENTLY...CONFIDENT SHORT RANGE MODELS ARE CORRECT IN
PRODUCING LITTLE TO NO ADDITIONAL SNOWFALL IN THE ELKHEAD AND PARK
RANGES. THEREFORE...WENT AHEAD AND CANCELLED THE WINTER WEATHER
ADVISORY WHICH WAS IN EFFECT FOR THE AREA THROUGH WEDNESDAY
MORNING.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 252 PM MST TUE FEB 25 2014
SHORT TERM FORECAST THROUGH THIS EVENING IS BASED ON RAP MODEL TRENDS
THAT SNOW WILL EXPAND SOUTHWARD OVER ROUTT COUNTY EARLY THIS
AFTERNOON. AS OF 21Z...STEAMBOAT LAKE WEB CAM INDICATE THAT SNOW
HAS REACHED HAHNS PEAK VICINITY...BUT NO MOUNTAIN TOP OBSCURATION
NEAR STEAMBOAT SPRINGS. EXPECT THIS TO CHANGE WITHIN THE NEXT
COUPLE OF HOURS AS LEADING EDGE OF BAROCLINIC ZONE AND DECENT
GRADIENT NORTHWEST FLOW LEADS TO OROGRAPHIC SNOW OVER THE MT
ZIRKEL WILDERNESS AREA AND THE PARK RANGE. RAP MODEL INDICATES
RAIN/SNOW BAND MAY EXTEND AS FAR WEST AS MAYBELL AND MEEKER LATE
THIS AFTERNOON AS THE MOISTURE BAND SLIDES SOUTH AND EAST.
PRIMARY CONCERN IS THAT THE AMPLIFYING UPSTREAM RIDGE AXIS HAS
PINCHED OFF THE PACIFIC MOISTURE STREAM INTO NORTHWEST COLORADO...
THIS IS EVIDENT ON THE SATELLITE IMAGES. NOT SURE WHETHER THE
FORECASTED SNOW AMOUNTS FOR THE PARK RANGE WILL REACH THE UPPER
RANGE OF AROUND 7 INCHES...BUT RAP QPF STILL INDICATE THAT A FEW
INCHES OF SNOW REMAIN POSSIBLE. WITH SNOW OBSERVED AT RIVERTON
AND LANDER IN WEST CENTRAL WYOMING...GIVING CREDENCE THAT THE SNOW
IS ON THE WAY. LESSER AMOUNTS OF SNOW IS ANTICIPATED FOR THE FLAT
TOP MOUNTAINS AND GORE RANGE (VAIL PASS)...DO NOT THINK THAT AN
EXPANSION OF THE WINTER WEATHER ADVISORY IS NECESSARY. MOISTURE
STREAM SLIDES EAST AFTER MIDNIGHT WITH MID LEVEL DRY STABLE AIR
ADVECTING INTO NORTHWEST COLORADO...THIS WILL SHUT DOWN OROGRAPHIC
SNOW FAIRLY QUICKLY LATE TONIGHT.
FOR THE SERN HALF OF THE FORECAST AREA THROUGH TONIGHT...CLEAR AND
DRY WEATHER IS EXPECTED FOR THE NEXT 12 TO 18 HOURS.
WEST COAST RIDGE SHIFTS INLAND ON WEDNESDAY BUT BROAD ISENTROPIC
UPGLIDE WILL RESULT IN AN INCREASE OF MID/HIGH LEVEL CLOUDS FROM
THE SOUTHWEST. NAM AND GFS SHOWING HINTS OF MOUNTAIN TOP SPOTTY
SNOW WEDNESDAY AFTERNOON AND NIGHT. SOMETIMES THIS IS OVERDONE BUT
THE TREND WILL BE FOR INCREASING CLOUDS WITH CIRROSTRATUS EVOLVING
INTO ALTOSTRATUS. WITH THE INCREASED CLOUD COVER...EXPECT
RELATIVELY MILD CONDITIONS WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 252 PM MST TUE FEB 25 2014
THE FORECAST AREA COMES UNDER THE INFLUENCE OF THE SUBTROPICAL JET
THROUGH THE WEEKEND. THIS TYPICALLY BRINGS BETTER MOISTURE BUT
MILDER TEMPERATURES WITH ASSOCIATED STORMS. BREEZY TO WINDY
CONDITIONS ARE EXPECTED IN THE MTNS AND HIGH VALLEYS...INTO THE
LOWER VALLEYS WITH SHOWERS.
THURSDAY...A TRANSIENT RIDGE PASSES IN THE EARLY AFTERNOON WITH
DEEPENING MOISTURE IN SW FLOW. 700MB SPECIFIC HUMIDITIES CLIMB TO
4 G/KG IN THE AFTERNOON. THERE IS SOME MODEL DISAGREEMENT ON
TEMPERATURES AND SNOW LEVELS. A COMPROMISE PUTS THE SNOW LEVELS
AROUND 7500FT/8500FT NORTH/SOUTH. THE DEEPEST MOISTURE IS IN THE
SOUTHERN-CENTRAL MTNS. MARGINAL INSTABILITY PRODUCES AREAS OF
STRONGER SHOWERS AND BRIEFLY LOWER SNOW LEVELS.
THURSDAY NIGHT...THE BEST FORCING OCCURS AS THE SUBTROPICAL JET
PUSHES INTO THE SOUTH THEN LIFTS INTO THE CENTRAL ZONES. SNOW
LEVELS LOWER INTO THE NORTHERN VALLEYS...TO 7500FT SOUTH.
FRIDAY IS A BRIEF BREAK UNDER AS A LOCAL RIDGE IS AMPLIFIED AHEAD
OF THE NEXT STRONG STORM BRINGING WARM ADVECTION. MOISTURE REMAINS
AT 4 G/KG SO SHOWERS INCREASE INTO THE AFTERNOON.
FRIDAY NIGHT-SATURDAY NIGHT...THE NEXT SUBTROPICAL JET STREAK LIFTS
THE EASTERN UTAH FRIDAY NIGHT THEN ACROSS WESTERN COLORADO ON
SATURDAY. AGAIN THERE IS A CONVECTIVE COMPONENT FRIDAY NIGHT INTO
SATURDAY. THERE IS AGAIN A CONVECTIVE COMPONENT TO THIS STORM.
SNOWFALL WILL FAVOR THE SOUTHERN AND CENTRAL MTNS. SNOW LEVELS
AROUND 7000FT. SATURDAY NIGHT IS TROUGH PASSAGE WITH NW FLOW
DEVELOPING. SNOW LEVEL DROPS TO AROUND 5000FT BUT WILL FAVOR THE
NW-FACING SLOPES OF THE COLORADO MTNS.
SUNDAY-TUESDAY...ARE NOW A FLAT ZONAL FLOW WITH THE POLAR FRONT
JET SETTLING INTO WYOMING THEN RAKING THE NORTH ON MONDAY. EXPECT
COOLER TEMPERATURES THROUGH THESE PERIODS WITH THE BEST SNOWFALL
FAVORING THE NORTHERN MTNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 958 PM MST TUE FEB 25 2014
VFR CONDITIONS ARE EXPECTED AT ALL TAF SITES THROUGH 06Z THU...BUT
LOW CLOUDS MAY BE PROBLEM FOR THE ERN UINTA MOUNTAINS AND NRN CO
MOUNTAINS INCLUDING KHDN/KSBS THROUGH MID-MORNING.
AN UPPER DISTURBANCE CROSSING NE CO PUSHED A COLD FRONT ACROSS NW CO
TO ABOUT THE I-70 CORRIDOR BEFORE CURVING BACK ACROSS NE UT. FRONT
SHOULD STALL OVERNIGHT. A BAND OF LOW-MID LEVEL CLOUDS EXTENDED FROM
THE CENTRAL DIVIDE AREA BACK ACROSS NW CO AND SW WY AND SHOULD
PERSIST UNTIL 12Z-15Z WED WITH MOUNTAIN TOPS OCCASIONALLY OBSCURED
IN CLOUDS/-SN FROM KASE/VAIL PASS NORTHWARD TO K3MW.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...NL
SHORT TERM...PF
LONG TERM...JOE
AVIATION...JAD
AREA FORECAST DISCUSSION
NWS ALBANY NY
1002 PM EST THU FEB 27 2014
.SYNOPSIS...
BITTERLY COLD ARCTIC AIR WILL CONTINUE TO FILTER INTO THE REGION
TONIGHT...WITH SNOW SHOWERS DIMINISHING. HIGH PRESSURE WILL SETTLE
IN FOR FRIDAY WITH CONTINUED COLD TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 1000 PM...MAIN CHANGE WITH THIS UPDATE WAS TO EXPAND THE
WIND CHILL ADVISORY TO INCLUDE THE WESTERN/CENTRAL MOHAWK VALLEY
AS WELL AS SOUTHERN WARREN COUNTY AND NORTHERN SARATOGA COUNTY.
TEMP/WIND FORECAST FOR TONIGHT INDICATING WIND CHILL VALUES
REACHING AT LEAST 20 BELOW ZERO FOR A GOOD PORTION OF THESE ZONES.
SNOW SHOWERS AND SQUALLS HAVE DIMINISHED THIS EVENING.
HOWEVER...AS EXPECTED LAKE EFFECT SNOW BANDS HAVE STARTED TO
IMPACT CENTRAL/SOUTHERN HERKIMER COUNTY. RADAR REFLECTIVITY
INDICATING MAINLY LIGHT RETURNS...ALTHOUGH OBS JUST UPSTREAM AT
KRME SHOW 1/2 MILE VISIBILITY SO SOME MODERATE BURSTS OF SNOW ARE
OCCURRING. LATEST HRRR AND LOCAL HIRES WRF INDICATING THE LAKE
BANDS WILL DRIFT SOUTHWARD AND WEAKEN OVERNIGHT...BUT WILL KEEP
THE LAKE EFFECT SNOW ADVISORY GOING HERKIMER COUNTY...SINCE SNOW
BANDS ARE RIGHT ON THE BORDER BETWEEN NORTHER/SOUTHERN ZONES. THE
ADVISORY WILL LIKELY BE CANCELLED WITH THE NEXT UPDATE FOR NORTHERN
HERKIMER. ADDITIONAL 2-4 INCHES POSSIBLE IN SOME SPOTS IN SOUTHERN
HERKIMER OVERNIGHT BEFORE BANDS DRIFT SOUTH AND WEAKEN.
OTHERWISE...A FEW FRAGMENTED LAKE EFFECT SNOW SHOWERS WILL MOVE
ACROSS THE SOUTHWEST ADIRONDACKS AND CENTRAL MOHAWK VALLEY BUT
WITH ONLY A DUSTING TO HALF INCH ACCUMULATION IN SOME SPOTS.
TEMPERATURES WILL CONTINUE TO DROP THROUGH THE SINGLE DIGITS AND
TEENS THROUGH THIS EVENING. LOW TEMPERATURES OVERNIGHT WILL
BOTTOM OUT CLOSE TO ZERO IN THE CAPITAL REGION SOUTHWARD...5 TO 15
BELOW ZERO ACROSS OUR NORTHERN AREAS. THE RECORD LOW FOR ALBANY
FOR FEBRUARY 28TH IS 10 BELOW ZERO SET BACK IN 1950 SO THAT LOOKS
SAFE FOR NOW. A PERSISTENT WESTERLY BREEZE WILL MAKE IT FEEL QUITE
COLD THOUGH.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD ON FRIDAY ENDING ANY AND ALL LAKE EFFECT
SNOW. FRIDAY LOOKS LIKE A MOSTLY SUNNY DAY BUT IT WILL REMAIN VERY
COLD FOR THIS TIME OF YEAR THANKS TO TO H850 TEMPERATURES -20C OR A
LITTLE LOWER ALL DAY LONG. DESPITE THE SUNSHINE..MIXING WITH FAIR
WEATHER CUMULUS CLOUDS...IT LOOKS AS IF TEMPERATURES WILL REMAIN IN
THE TEENS IN VALLEY LOCATIONS...SINGLE NUMBERS ACROSS THE HIGHER
TERRAIN WITH OF THE COLDEST SPOTS IN THE ADIRONDACKS NOT MAKING IT
PAST ZERO DEGREES. WE WILL BE CLOSE TO A RECORD MAX AT ALBANY FOR
THE LAST DAY OF FEBRUARY. WE ARE FORECASTING A HIGH OF 15 WITH THE
RECORD COLD HIGH OF 13 DEGREES SET BACK IN 1879.
FRIDAY NIGHT WILL BE MORE CHALLENGING TO FORECAST LOW TEMPERATURES.
WARM AIR ADVECTION CLOUDS WILL LIKELY BEGIN TO STREAM ACROSS THE
REGION. THE QUESTION IS HOW QUICKLY THESE CLOUDS COME IN. IF THEY
COME IN SLOWLY TOWARD DAYBREAK..TEMPERATURES COULD TUMBLE TO WELL
BELOW ZERO ACROSS MOST OF THE AREA. A SOUTHERLY BREEZE MIGHT HOLD
TEMPERATURES UP LOCALLY IN THE CAPITAL REGION BUT THAT IS NOT
ETCHED IN STONE. FOR NOW...WE WENT ON THE LOW SIDE OF GUIDANCE IN
MOST PLACES...WHICH PUTS MOST AREAS CLOSE TO ZERO FROM ALBANY
SOUTH...WITH NORTHERN AREAS GETTING AS LOW AS 10 BELOW ZERO ONCE
MORE. THERE WILL BE NOT MUCH WIND SO WIND CHILL ADVISORIES WILL
NOT BE NEEDED.
SATURDAY...WILL FEATURE A BIT MORE CLOUDS THAN FRIDAY. A SOUTHERLY
BREEZE AHEAD OF THE NEXT CLIPPER SYSTEM WILL BOOST TEMPERATURES
UP...BUT THEY WILL STILL FALL SHORT OF NORMAL. IT LOOKS AS IF THIS
NEXT SYSTEM WILL INITIALLY BE MOISTURE STARVED SO WE LOWERED POPS TO
SLIGHT CHANCES FROM THE CAPITAL REGION NORTHWARD...LOW CHANCES TO
THE WEST OF THE CAPITAL DISTRICT. LOOK FOR HIGHS GENERALLY IN THE
20S.
SATURDAY NIGHT...THE CLIPPER AND ITS ASSOCIATED COLD FRONT WILL
APPROACH WITH MORE SCATTERED SNOW SHOWERS...MOST NUMEROUS IN THE
USUAL SPOTS...THE ADIRONDACKS AND MOHAWK VALLEY. ANY ACCUMULATIONS
LOOK GENERALLY LIGHT. A PERSISTENT SOUTHERLY BREEZE SHOULD KEEP
TEMPERATURES FROM FALLING MUCH...GENERALLY IN THE TEENS TO AROUND
20.
SUNDAY...THE CLIPPER WILL MOVE EAST. THE TRAILING COLD FRONT COULD
PRODUCE SOME LINGERING SNOW SHOWERS...ESPECIALLY SOUTH OF THE
CAPITAL REGION. THAT FRONT LOOKS TO STALL SOMEWHERE TO OUR SOUTH BY
MONDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
STARTING OUT SUNDAY NIGHT INTO MONDAY...BASED ON THE LATEST GUIDANCE
IT APPEARS SOMEWHERE IN OUR AREA WILL BE ALONG THE NORTHERN FRINGE
OF A SNOW SHIELD ASSOCIATED WITH ISENTROPIC LIFT TO THE NORTH OF A
FRONTAL BOUNDARY AND CYCLONE TRACKING EASTWARD ACROSS THE TENNESSEE
VALLEY AND CAROLINAS. THIS SYSTEM WILL BE BATTLING A STRONG AND
SPRAWLING AREA OF HIGH PRESSURE BUILDING EASTWARD THROUGH SOUTHEAST
CANADA AND THE UPPER GREAT LAKES. THE MAIN FACTORS WILL BE THE
STRENGTH/TIMING OF THE HIGH VS THE SOUTHERN STREAM WAVE AND FRONT.
MODELS HAVE TRENDED FARTHER SOUTH WITH THE HEAVIEST QPF...WHICH IS
NOW FORECAST OVER PA/NJ/LONG ISLAND. WHILE THERE STILL IS EXPECTED
TO BE SOME SNOWFALL IN EAST CENTRAL NEW YORK AND WESTERN NEW
ENGLAND...ESPECIALLY FROM THE CAPITAL REGION SOUTHWARD...THERE ALSO
COULD BE A RATHER SHARP NORTHERN GRADIENT TO THE SNOWFALL. THIS MAY
RESULT IN THE ADIRONDACKS/LAKE GEORGE REGION POSSIBLY NOT SEEING
MUCH IF ANY SNOW. WILL CONTINUE TO MENTION LIKELY POPS FOR THE
SOUTHERN HALF OF THE AREA...WITH THE GREATEST POTENTIAL FOR A
PLOWABLE SNOW FOR THE CATSKILLS...MID HUDSON VALLEY...SOUTHERN
BERKSHIRES AND LITCHFIELD HILLS. SINCE THIS SYSTEM IS STILL ABOUT
FOUR DAY AWAY...WE WILL CONTINUE TO MONITOR TRENDS FOR POSSIBLE
CHANGES IN THE FORECAST.
MAINLY DRY AND COLD CONDITIONS ARE EXPECTED FOR THE MID WEEK
PERIOD...AS HIGH PRESSURE SETTLES ACROSS THE REGION. TEMPERATURES
LOOK TO CONTINUE TO BE BELOW NORMAL THROUGH AT LEAST THE NEXT 7 DAYS.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SCATTERED SNOW SHOWERS AND SQUALLS WILL CONTINUE INTO THIS EVENING
ASSOCIATED WITH A DISTURBANCE MOVING ACROSS THE AREA. AN ARCTIC COLD
FRONT HAS NOW PUSHED THROUGH...WITH TEMPERATURES DROPPING AND
NORTHWEST WINDS INCREASING.
WILL MENTION TEMPO GROUPS FOR SNOW SHOWERS THROUGH AROUND 01Z AT
KALB/KPSF/KGFL TO ACCOUNT FOR CURRENT ACTIVITY. HOWEVER...AS THE
DISTURBANCE MOVES THROUGH LATER THIS EVENING SNOW SHOWERS ARE
EXPECTED TO DISSIPATE. MAINLY VFR CONDITIONS WILL PREVAIL...ALTHOUGH
MVFR/IFR CONDITIONS WILL BE LIKELY WITH ANY SNOW SHOWERS PASSING
THROUGH. SNOW SHOWERS EXPECTED TO REMAIN NORTH OF KPOU. VFR
CONDITIONS AND MAINLY CLEAR SKIES FORECAST FROM LATE TONIGHT THROUGH
FRIDAY AS HIGH PRESSURE SETTLES IN OVER THE REGION.
WINDS WILL BE STRONGEST THIS EVENING FROM THE WEST-NORTHWEST AROUND
15-25 KT WITH GUSTS OF 30-40 KT. WIND SPEEDS WILL DECREASE LATER
THIS EVENING...AND ESPECIALLY AFTER MIDNIGHT TO AROUND 10-15 KT.
OUTLOOK...
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY NIGHT TO SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE
OF SHSN.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
MONDAY: MODERATE OPERATIONAL IMPACT. LIKELY SN.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS. AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA
INTO THE WEEKEND...WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK.
LIGHT PRECIPITATION IN THE FORM OF SNOW SHOWERS ARE EXPECTED INTO
THE MAJORITY OF THE WEEKEND.
A SIGNIFICANT STORM SYSTEM MAY BRING SNOW...MAINLY FROM ALBANY LATE
SUNDAY INTO MONDAY NIGHT.
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 ADVISORY UNTIL 9 AM EST FRIDAY FOR CTZ001.
NY...WIND CHILL ADVISORY UNTIL 9 AM EST FRIDAY FOR NYZ032-033-
038>042-047-048-051-058-063-082-083.
LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST FRIDAY FOR NYZ032-038.
MA...WIND CHILL ADVISORY UNTIL 9 AM EST FRIDAY FOR MAZ001-025.
VT...WIND CHILL ADVISORY UNTIL 9 AM EST FRIDAY FOR VTZ013-014.
&&
$$
SYNOPSIS...HWJIV/JPV
NEAR TERM...HWJIV/JPV
SHORT TERM...HWJIV
LONG TERM...JPV
AVIATION...JPV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1248 PM EST WED FEB 26 2014
.SYNOPSIS...
A CLIPPER LOW CONTINUES TO MOVE ACROSS SOUTHERN QUEBEC THIS
AFTERNOON...AS ITS COLD FRONT MOVES THROUGH NEW ENGLAND WITH A
REINFORCING SHOT OF ARCTIC AIR BEHIND IT. ANOTHER CLIPPER WILL BRING
A CHANCE OF MORE SNOW SHOWERS AND SNOW SQUALLS ON THURSDAY WITH SOME
BITTERLY COLD AIR FOR EASTERN NEW YORK AND WESTERN NEW ENGLAND
THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1233 PM EST...CLIPPER TYPE LOW CONTINUES TO MOVE ACROSS SRN
QUEBEC TOWARDS NRN ME AND NEW BRUNSWICK. THE COLD FRONT HAS MOVED
THROUGH WITH DIFFUSE SNOW SHOWERS AND FLURRIES...ASIDE FROM A LAKE
EFFECT SNOWBAND COMING OFF LAKE ONTARIO INTO THE TUG HILL PLATUEAU
INTO THE WRN DACKS AND MOST SPECIFICALLY NRN HERKIMER CO. THE
INLAND EXTENT HAS BEEN DIFFICULT DOWNSTREAM. THE LAKE EFFECT SNOW
ADVISORY REMAINS IN EFFECT FOR HERKIMER CO...BUT WE MAY DROP SRN
HERKIMER WITH THE NEXT UPDATE...AS THE 260-270 DEG TRAJECTORY
FAVORS NRN HERKIMER. THE LATEST HRRR GUIDANCE SHOWS THE BAND
WEAKENING BY THIS EVENING AND LIFTING NORTHWARD. WE ALSO LOWERED
AMOUNTS TO 3 TO 6 INCHES FOR THE AREA. MOST OF THE SCT SNOW
SHOWERS PRODUCED LESS THAN AN INCH OF SNOW. PLEASE SEE OUR LATEST
PNS...WITH ISOLD HIGHER AMOUNTS. TEMPS LOOKS ON TRACK WITH BRISK
CONDITIONS AND HIGHS A SOLID 10 TO 15 DEGREES BELOW NORMAL.
H850 TEMPS CRASH AGAIN TO -19C TO -22C OVER THE FCST AREA BY THE
LATE PM. IT WILL ALSO BECOME WINDY IN THE WAKE OF THE FRONT WITH
UPSLOPE SNOW SHOWERS POSSIBLE OVER THE TACONICS...BERKSHIRES...AND
SRN GREENS. IN ADDITION TO LAKE EFFECT SNOWS THERE IS THE
SLIGHT POSSIBILITY OF A WINDEX TYPE EVENT IN THE WAKE OF THE
ARCTIC FRONT AS RH VALUES IN THE LOWER LEVELS ARE GREATER THAN 70
PERCENT AND T1-T5 LAYER TEMPS DIFFER BY MORE THAN 10 C. IT WILL BE
VERY CHILLY TODAY WITH HIGHS ONLY RANGING FROM THE LOW TO MID
TEENS NORTHWEST TO THE LOW TO MID 20S SOUTHEAST.
TONIGHT....BLUSTERY CONDITIONS WILL PERSIST THROUGH THE EVENING
HOURS AND THE LAKE EFFECT BAND WILL COME TO AN END AS A WEAK RIDGE
OF HIGH PRESSURE BUILDS IN FROM THE SOUTH AHEAD OF THE NEXT
CLIPPER TYPE SYSTEM WHICH WILL ALREADY BE MOVING INTO THE SE
ONTARIO AND THE ERN GREAT LAKES REGION BY LATE TONIGHT. WIND CHILL
VALUES WILL BE CLOSE TO ADVISORY CRITERIA AND MAINLY ACROSS THE
WESTERN ADIRONDACKS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM 10
BELOW TO 5 ABOVE ZERO.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THU-THU NIGHT....THE SECOND CLIPPER TYPE SYSTEM IMPACTS THE FA AS
IT MOVES ACROSS SOUTHERN QUEBEC...NRN NY AND NRN NEW ENGLAND
SWINGING ANOTHER ARCTIC COLD FRONT THROUGH OUR REGION. THIS
SYSTEM IS EVEN STRONGER THAN THE FIRST CLIPPER TYPE SYSTEM AND
LOOKS TO SET UP A CLASSIC WINDEX EVENT IN THE WAKE OF THE COLD
FRONT WHICH WILL BE ENHANCED BY A SECONDARY TROUGH OF LOW PRESSURE.
THE BEST MOISTURE CONVERGENCE LOOKS LIKE IT WILL BE OVER THE WRN
DACKS AGAIN...WHERE A FEW INCHES OF SNOW LOOK LIKELY. MOST OTHER
LOCATIONS WILL RECEIVE A DUSTING TO AN TWO INCHES. THE WIND FIELDS
STRENGTHEN IN THE WAKE OF THE CLIPPER WITH SW WINDS SHIFTING TO
THE WEST WITH THE FRONTAL PASSAGE IN THE AFTERNOON. WEST WINDS OF
15 TO 25 MPH WITH SOME GUSTS TO 35 TO 40 MPH WILL BE POSSIBLE DUE
TO FUNNELING DOWN THE MOHAWK VALLEY INTO THE CAPITAL REGION INTO
THE CNTRL TACONICS...AND BERKSHIRES. THESE GUSTY WINDS ARE ALSO
EXPECTED IN THE ERN AND NRN CATSKILLS. HIGHS ON THURSDAY WILL
GENERALLY BE IN THE UPPER TEENS TO UPPER 20S. LOWS THURSDAY NIGHT
WILL BE IN THE 10 BELOW ZERO TO 5 ABOVE ZERO RANGE WITH WIND CHILL
VALUES REACHING ADVISORY CRITERIA ACROSS SOME OF THE HIGHER
TERRAIN.
FRIDAY AND FRIDAY NIGHT HIGH PRESSURE WILL PROVIDE PLENTY OF
SUNSHINE TO THE REGION ALTHOUGH IT WILL STILL BE VERY COLD AND
BLUSTERY. EXPECT HIGH ON FRIDAY TO BE IN THE TEENS TO AROUND 20
WITH PERHAPS ONLY SINGLE DIGITS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS. LOWS FRIDAY NIGHT WILL BE IN THE 10 BELOW TO 5 ABOVE
ZERO RANGE ONCE AGAIN.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
BELOW TO MUCH BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
LONG TERM PORTION OF THE FORECAST. IN ADDITION...THE POTENTIAL FOR
STORMINESS WILL INCREASE...ESP BY SUN NT-MON...AS SHORTWAVE ENERGY
ORIGINATING OVER THE SOUTHWEST U.S. EJECTS RAPIDLY
NORTHEASTWARD...AHEAD OF A LONG WAVE TROUGH PIVOTING SLOWLY E/SE
ACROSS THE NORTHERN PLAINS.
OVERALL...MODELS HAVE TRENDED SLIGHTLY SOUTHWARD WITH REGARD TO
THEIR RESPECTIVE SURFACE FEATURES COMPARED TO 24 HOURS AGO /00Z 25
RUNS/.
TAKING A LOOK AT SOME PV TRACES...IT APPEARS THAT ENERGY CURRENTLY
DIGGING SOUTHWARD WELL SOUTHWEST OF THE ALEUTIAN ISLANDS WILL BE THE
MAIN DRIVER FOR EARLY NEXT WEEK...AS THIS PV ANOMALY POSSIBLY
REACHES SOUTHERN CA EARLY THIS WEEKEND...AS THE UPPER LEVEL
TROUGH/LOW CURRENTLY FURTHER EAST SPLITS INTO TWO PIECES...ONE
TRANSLATING NORTHWARD WELL OFF THE PACIFIC NW COAST...AND ANOTHER
PIECE TRANSLATES EAST AND WEAKENS...AFFECTING OUR REGION ON
SATURDAY. THE MODELS SEEM TO HANDLE THE DIGGING ENERGY
DIFFERENTLY...WITH THE 00Z/26 ECMWF A BIT FASTER IN PROGRESSING THIS
ENERGY OUT ACROSS THE SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY FOR
SUN-MON...AND ALSO KEEPING THE ENERGY IN TACT A BIT LONGER...WHILE
THE 00Z/26 GFS IS SLOWER...AND SEEMS TO WEAKEN/SHEAR THIS ENERGY
FASTER WITH A SOMEWHAT FLATTER WAVE FOR AFFECTING THE REGION FOR
LATE MON INTO TUE. HAVE SIDED CLOSER TO THE 00Z/26 WPC/ECMWF
SOLUTIONS.
EITHER WAY...IT APPEARS THAT WARM ADVECTION WELL AHEAD OF ANY SUCH
WAVE SHOULD ALLOW CLOUDS AND PRECIP TO DEVELOP SUN NT...AND INTO
MONDAY...BEFORE POSSIBLY TAPERING OFF LATE MON NT OR TUES. BASED ON
CURRENT 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE...SOUTHERN
PORTIONS OF THE FORECAST AREA APPEAR TO BE MOST FAVORED FOR MODERATE
OR GREATER AMOUNTS OF PRECIPITATION...BUT AGAIN...THIS SOUTHWARD
MODEL TREND STARTED WITHIN THE LAST 24 HOURS...AND WOULD NOT BE
SURPRISED TO ULTIMATELY SEE MODELS SOLUTIONS TREND BACK SLIGHTLY
NORTHWARD AGAIN OVER THE NEXT 1-3 DAYS WITH REGARD TO THIS POTENTIAL
STORM SYSTEM.
HERE ARE SOME MORE SPECIFICS...
SAT-SUN...THE FIRST WAVE IS EXPECTED TO WEAKEN...AND TRANSLATE
RAPIDLY EAST/NORTHEAST ON SAT. A SURGE OF WEAK WARM ADVECTION SHOULD
ALLOW FOR ABUNDANT CLOUDS AND SOME LIGHT SNOW/SNOW SHOWERS TO
OVERSPREAD THE REGION LATE SAT MORNING INTO THE
AFTERNOON...ESPECIALLY FOR AREAS NEAR AND WEST OF THE HUDSON RIVER.
THE SNOW SHOWERS ARE EXPECTED TO SINK SOUTHWARD SAT NT AND EARLY
SUNDAY...AS THE ASSOCIATED ARCTIC FRONTAL BOUNDARY ALSO DROPS SOUTH.
WILL THEREFORE INDICATE CHC POPS FOR MOST AREAS FROM ALBANY N AND
W...AND MAINLY SLIGHT CHC TO THE S/E THROUGH SAT...THEN CHC POPS ALL
AREAS FOR SAT NT INTO EARLY SUN...WITH SOME LIKELY POPS FOR NW
AREAS.
THERE IS A POSSIBILITY THAT SNOW SHOWERS AND/OR AREAS OF LIGHT SNOW
ACTUALLY TAPER OFF ACROSS NORTHERN AREAS SUNDAY
AFTERNOON/EVENING...AS THE FRONT AND ASSOCIATED MID LEVEL FORCING
SHIFTS FURTHER SOUTH. WILL THEREFORE TAPER POPS IN THE AFTERNOON FOR
NORTHERN AREAS INTO THE SLIGHT CHC RANGE...WITH CHC POPS REMAINING
FOR CENTRAL AND SOUTHERN AREAS.
SUN NT-MON...THE AFOREMENTIONED SECOND WAVE SHOULD EJECT OUT OF THE
SOUTHWEST U.S...AND WILL CONTINUE TRANSLATING E/NE...ALLOWING A
LARGE AREA OF ISENTROPIC LIFT TO DEVELOP ACROSS THE REGION. THIS
SHOULD ALLOW FOR SNOW TO OVERSPREAD THE REGION SUN NT...AND CONTINUE
THROUGH MONDAY. SNOW SHOULD BE THE MAIN P-TYPE FOR MOST AREAS. BASED
ON THE SLIGHT SOUTHWARD TREND OF THE 00Z/26 MODELS WITH REGARD TO
STRONGEST MID LEVEL FORCING AND MOISTURE...HAVE ADDED LIKELY POPS
ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA...WITH CHC
POPS ELSEWHERE.
TEMPS WILL REMAIN BELOW TO MUCH BELOW NORMAL THROUGH THE PERIOD. THE
MILDEST DAY SHOULD BE SATURDAY...AHEAD OF THE INCOMING ARCTIC
FRONTAL BOUNDARY...WITH MAX TEMPS REACHING THE LOWER 30S IN VALLEY
AREAS...AND 20S ACROSS MOST HIGHER ELEVATIONS. FOR SAT NT/SUN
AM...AS THE ARCTIC BOUNDARY SINKS SOUTHWARD...TEMPS SHOULD FALL INTO
THE TEENS IN MOST AREAS...EXCEPT FOR SINGLE DIGITS ACROSS PORTIONS
OF THE ADIRONDACKS. ON SUNDAY...MAX TEMPS SHOULD GENERALLY ONLY
REACH THE 20S IN VALLEYS WITH TEENS ACROSS THE ADIRONDACKS. TEMPS
SHOULD THEN FALL INTO THE SINGLE DIGITS TO MID TEENS SUN NT...AND
THEN ONLY RISE INTO THE TEENS AND 20S FOR MONDAY...ALTHOUGH THERE IS
THE POTENTIAL FOR EVEN COLDER MAX TEMPS IF ENOUGH LOW LEVEL ARCTIC
AIR SEEPS SOUTHWARD INTO THE REGION IN THE WAKE OF THE WEEKEND
WAVE...AND IF SNOW FALLS INTO THIS COLD AND RELATIVELY DRY LOW LEVEL
AIR. EXPECT SINGLE DIGITS AND TEENS AGAIN FOR MON NT/TUE AM...WITH
TUE MAXES MAINLY IN THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER
ELEVATIONS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
PREDOMINATELY VFR CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD
WITH SCATTERED SNOW SHOWERS DIMINISHING BY THIS EVENING.
THIS AFTERNOON...WIDELY SCATTERED SNOW SHOWERS ASSOCIATED WITH A
WEAK CLIPPER AND COLD FRONT WILL CONTINUE THROUGH THE AFTERNOON
HOURS...ESPECIALLY AT KGFL WHERE SOME LAKE MOISTURE WILL ALSO BE
TAPPED. HAVE INCLUDED A TEMPO GROUP AT KGFL UNTIL 20Z TO ACCOUNT FOR
ANY BRIEF IFR REDUCTIONS IN HEAVIER SNOW SHOWERS...AND VCSH AT THE
OTHER TAF SITES DUE TO WIDELY SCATTERED NATURE OF THE SHOWERS.
WESTERLY WINDS WILL BE GUSTY THIS AFTERNOON...GUSTING 20-25 KNOTS
EXCEPT AT KALB AND KPSF WHERE GUSTS AS HIGH AS 35 KNOTS WILL BE
POSSIBLE.
TONIGHT INTO THURSDAY...THE LOSS OF DAYTIME HEATING WILL HELP WINDS
SUBSIDE THIS EVENING ALONG WITH GRADUALLY CLEARING SKIES AS WEAK
HIGH PRESSURE BUILDS ACROSS THE REGION. MID CLOUDS WILL GRADUALLY
BUILD FROM WEST TO EAST ACROSS THE REGION AHEAD OF ANOTHER
APPROACHING CLIPPER SYSTEM WITH VCSH DEVELOPING BY THE END OF THE
TAF PERIOD...ESPECIALLY NORTH AND WEST.
WINDS WILL BE LIGHT AND VARIABLE TONIGHT GENERALLY LESS THAN 8 KNOTS
BEFORE INCREASING AFTER DAYBREAK THURSDAY OUT OF THE SOUTHWEST AT
10-15 KNOTS WITH GUSTS 20-25 KNOTS.
OUTLOOK...
THURSDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY SLIGHT CHANCE OF SHSN.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY-MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN.
&&
.HYDROLOGY...
NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS. AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA
FOR THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK.
LIGHT PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT
DOES OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW FROM
CLIPPER LOWS OR LAKE EFFECT.
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...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ032-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/NAS/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...IRL
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1233 PM EST WED FEB 26 2014
.SYNOPSIS...
A CLIPPER LOW CONTINUES TO MOVE ACROSS SOUTHERN QUEBEC THIS
AFTERNOON...AS ITS COLD FRONT MOVES THROUGH NEW ENGLAND WITH A
REINFORCING SHOT OF ARCTIC AIR BEHIND IT. ANOTHER CLIPPER WILL BRING
A CHANCE OF MORE SNOW SHOWERS AND SNOW SQUALLS ON THURSDAY WITH SOME
BITTERLY COLD AIR FOR EASTERN NEW YORK AND WESTERN NEW ENGLAND
THURSDAY NIGHT INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1233 PM EST...CLIPPER TYPE LOW CONTINUES TO MOVE ACROSS SRN
QUEBEC TOWARDS NRN ME AND NEW BRUNSWICK. THE COLD FRONT HAS MOVED
THROUGH WITH DIFFUSE SNOW SHOWERS AND FLURRIES...ASIDE FROM A LAKE
EFFECT SNOWBAND COMING OFF LAKE ONTARIO INTO THE TUG HILL PLATUEAU
INTO THE WRN DACKS AND MOST SPECIFICALLY NRN HERKIMER CO. THE
INLAND EXTENT HAS BEEN DIFFICULT DOWNSTREAM. THE LAKE EFFECT SNOW
ADVISORY REMAINS IN EFFECT FOR HERKIMER CO...BUT WE MAY DROP SRN
HERKIMER WITH THE NEXT UPDATE...AS THE 260-270 DEG TRAJECTORY
FAVORS NRN HERKIMER. THE LATEST HRRR GUIDANCE SHOWS THE BAND
WEAKENING BY THIS EVENING AND LIFTING NORTHWARD. WE ALSO LOWERED
AMOUNTS TO 3 TO 6 INCHES FOR THE AREA. MOST OF THE SCT SNOW
SHOWERS PRODUCED LESS THAN AN INCH OF SNOW. PLEASE SEE OUR LATEST
PNS...WITH ISOLD HIGHER AMOUNTS. TEMPS LOOKS ON TRACK WITH BRISK
CONDITIONS AND HIGHS A SOLID 10 TO 15 DEGREES BELOW NORMAL.
H850 TEMPS CRASH AGAIN TO -19C TO -22C OVER THE FCST AREA BY THE
LATE PM. IT WILL ALSO BECOME WINDY IN THE WAKE OF THE FRONT WITH
UPSLOPE SNOW SHOWERS POSSIBLE OVER THE TACONICS...BERKSHIRES...AND
SRN GREENS. IN ADDITION TO LAKE EFFECT SNOWS THERE IS THE
SLIGHT POSSIBILITY OF A WINDEX TYPE EVENT IN THE WAKE OF THE
ARCTIC FRONT AS RH VALUES IN THE LOWER LEVELS ARE GREATER THAN 70
PERCENT AND T1-T5 LAYER TEMPS DIFFER BY MORE THAN 10 C. IT WILL BE
VERY CHILLY TODAY WITH HIGHS ONLY RANGING FROM THE LOW TO MID
TEENS NORTHWEST TO THE LOW TO MID 20S SOUTHEAST.
TONIGHT....BLUSTERY CONDITIONS WILL PERSIST THROUGH THE EVENING
HOURS AND THE LAKE EFFECT BAND WILL COME TO AN END AS A WEAK RIDGE
OF HIGH PRESSURE BUILDS IN FROM THE SOUTH AHEAD OF THE NEXT
CLIPPER TYPE SYSTEM WHICH WILL ALREADY BE MOVING INTO THE SE
ONTARIO AND THE ERN GREAT LAKES REGION BY LATE TONIGHT. WIND CHILL
VALUES WILL BE CLOSE TO ADVISORY CRITERIA AND MAINLY ACROSS THE
WESTERN ADIRONDACKS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM 10
BELOW TO 5 ABOVE ZERO.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THU-THU NIGHT....THE SECOND CLIPPER TYPE SYSTEM IMPACTS THE FA AS
IT MOVES ACROSS SOUTHERN QUEBEC...NRN NY AND NRN NEW ENGLAND
SWINGING ANOTHER ARCTIC COLD FRONT THROUGH OUR REGION. THIS
SYSTEM IS EVEN STRONGER THAN THE FIRST CLIPPER TYPE SYSTEM AND
LOOKS TO SET UP A CLASSIC WINDEX EVENT IN THE WAKE OF THE COLD
FRONT WHICH WILL BE ENHANCED BY A SECONDARY TROUGH OF LOW PRESSURE.
THE BEST MOISTURE CONVERGENCE LOOKS LIKE IT WILL BE OVER THE WRN
DACKS AGAIN...WHERE A FEW INCHES OF SNOW LOOK LIKELY. MOST OTHER
LOCATIONS WILL RECEIVE A DUSTING TO AN TWO INCHES. THE WIND FIELDS
STRENGTHEN IN THE WAKE OF THE CLIPPER WITH SW WINDS SHIFTING TO
THE WEST WITH THE FRONTAL PASSAGE IN THE AFTERNOON. WEST WINDS OF
15 TO 25 MPH WITH SOME GUSTS TO 35 TO 40 MPH WILL BE POSSIBLE DUE
TO FUNNELING DOWN THE MOHAWK VALLEY INTO THE CAPITAL REGION INTO
THE CNTRL TACONICS...AND BERKSHIRES. THESE GUSTY WINDS ARE ALSO
EXPECTED IN THE ERN AND NRN CATSKILLS. HIGHS ON THURSDAY WILL
GENERALLY BE IN THE UPPER TEENS TO UPPER 20S. LOWS THURSDAY NIGHT
WILL BE IN THE 10 BELOW ZERO TO 5 ABOVE ZERO RANGE WITH WIND CHILL
VALUES REACHING ADVISORY CRITERIA ACROSS SOME OF THE HIGHER
TERRAIN.
FRIDAY AND FRIDAY NIGHT HIGH PRESSURE WILL PROVIDE PLENTY OF
SUNSHINE TO THE REGION ALTHOUGH IT WILL STILL BE VERY COLD AND
BLUSTERY. EXPECT HIGH ON FRIDAY TO BE IN THE TEENS TO AROUND 20
WITH PERHAPS ONLY SINGLE DIGITS ACROSS PORTIONS OF THE WESTERN
ADIRONDACKS. LOWS FRIDAY NIGHT WILL BE IN THE 10 BELOW TO 5 ABOVE
ZERO RANGE ONCE AGAIN.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
BELOW TO MUCH BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
LONG TERM PORTION OF THE FORECAST. IN ADDITION...THE POTENTIAL FOR
STORMINESS WILL INCREASE...ESP BY SUN NT-MON...AS SHORTWAVE ENERGY
ORIGINATING OVER THE SOUTHWEST U.S. EJECTS RAPIDLY
NORTHEASTWARD...AHEAD OF A LONG WAVE TROUGH PIVOTING SLOWLY E/SE
ACROSS THE NORTHERN PLAINS.
OVERALL...MODELS HAVE TRENDED SLIGHTLY SOUTHWARD WITH REGARD TO
THEIR RESPECTIVE SURFACE FEATURES COMPARED TO 24 HOURS AGO /00Z 25
RUNS/.
TAKING A LOOK AT SOME PV TRACES...IT APPEARS THAT ENERGY CURRENTLY
DIGGING SOUTHWARD WELL SOUTHWEST OF THE ALEUTIAN ISLANDS WILL BE THE
MAIN DRIVER FOR EARLY NEXT WEEK...AS THIS PV ANOMALY POSSIBLY
REACHES SOUTHERN CA EARLY THIS WEEKEND...AS THE UPPER LEVEL
TROUGH/LOW CURRENTLY FURTHER EAST SPLITS INTO TWO PIECES...ONE
TRANSLATING NORTHWARD WELL OFF THE PACIFIC NW COAST...AND ANOTHER
PIECE TRANSLATES EAST AND WEAKENS...AFFECTING OUR REGION ON
SATURDAY. THE MODELS SEEM TO HANDLE THE DIGGING ENERGY
DIFFERENTLY...WITH THE 00Z/26 ECMWF A BIT FASTER IN PROGRESSING THIS
ENERGY OUT ACROSS THE SOUTHERN PLAINS AND EVENTUALLY OHIO VALLEY FOR
SUN-MON...AND ALSO KEEPING THE ENERGY IN TACT A BIT LONGER...WHILE
THE 00Z/26 GFS IS SLOWER...AND SEEMS TO WEAKEN/SHEAR THIS ENERGY
FASTER WITH A SOMEWHAT FLATTER WAVE FOR AFFECTING THE REGION FOR
LATE MON INTO TUE. HAVE SIDED CLOSER TO THE 00Z/26 WPC/ECMWF
SOLUTIONS.
EITHER WAY...IT APPEARS THAT WARM ADVECTION WELL AHEAD OF ANY SUCH
WAVE SHOULD ALLOW CLOUDS AND PRECIP TO DEVELOP SUN NT...AND INTO
MONDAY...BEFORE POSSIBLY TAPERING OFF LATE MON NT OR TUES. BASED ON
CURRENT 00Z/26 DETERMINISTIC AND ENSEMBLE GUIDANCE...SOUTHERN
PORTIONS OF THE FORECAST AREA APPEAR TO BE MOST FAVORED FOR MODERATE
OR GREATER AMOUNTS OF PRECIPITATION...BUT AGAIN...THIS SOUTHWARD
MODEL TREND STARTED WITHIN THE LAST 24 HOURS...AND WOULD NOT BE
SURPRISED TO ULTIMATELY SEE MODELS SOLUTIONS TREND BACK SLIGHTLY
NORTHWARD AGAIN OVER THE NEXT 1-3 DAYS WITH REGARD TO THIS POTENTIAL
STORM SYSTEM.
HERE ARE SOME MORE SPECIFICS...
SAT-SUN...THE FIRST WAVE IS EXPECTED TO WEAKEN...AND TRANSLATE
RAPIDLY EAST/NORTHEAST ON SAT. A SURGE OF WEAK WARM ADVECTION SHOULD
ALLOW FOR ABUNDANT CLOUDS AND SOME LIGHT SNOW/SNOW SHOWERS TO
OVERSPREAD THE REGION LATE SAT MORNING INTO THE
AFTERNOON...ESPECIALLY FOR AREAS NEAR AND WEST OF THE HUDSON RIVER.
THE SNOW SHOWERS ARE EXPECTED TO SINK SOUTHWARD SAT NT AND EARLY
SUNDAY...AS THE ASSOCIATED ARCTIC FRONTAL BOUNDARY ALSO DROPS SOUTH.
WILL THEREFORE INDICATE CHC POPS FOR MOST AREAS FROM ALBANY N AND
W...AND MAINLY SLIGHT CHC TO THE S/E THROUGH SAT...THEN CHC POPS ALL
AREAS FOR SAT NT INTO EARLY SUN...WITH SOME LIKELY POPS FOR NW
AREAS.
THERE IS A POSSIBILITY THAT SNOW SHOWERS AND/OR AREAS OF LIGHT SNOW
ACTUALLY TAPER OFF ACROSS NORTHERN AREAS SUNDAY
AFTERNOON/EVENING...AS THE FRONT AND ASSOCIATED MID LEVEL FORCING
SHIFTS FURTHER SOUTH. WILL THEREFORE TAPER POPS IN THE AFTERNOON FOR
NORTHERN AREAS INTO THE SLIGHT CHC RANGE...WITH CHC POPS REMAINING
FOR CENTRAL AND SOUTHERN AREAS.
SUN NT-MON...THE AFOREMENTIONED SECOND WAVE SHOULD EJECT OUT OF THE
SOUTHWEST U.S...AND WILL CONTINUE TRANSLATING E/NE...ALLOWING A
LARGE AREA OF ISENTROPIC LIFT TO DEVELOP ACROSS THE REGION. THIS
SHOULD ALLOW FOR SNOW TO OVERSPREAD THE REGION SUN NT...AND CONTINUE
THROUGH MONDAY. SNOW SHOULD BE THE MAIN P-TYPE FOR MOST AREAS. BASED
ON THE SLIGHT SOUTHWARD TREND OF THE 00Z/26 MODELS WITH REGARD TO
STRONGEST MID LEVEL FORCING AND MOISTURE...HAVE ADDED LIKELY POPS
ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA...WITH CHC
POPS ELSEWHERE.
TEMPS WILL REMAIN BELOW TO MUCH BELOW NORMAL THROUGH THE PERIOD. THE
MILDEST DAY SHOULD BE SATURDAY...AHEAD OF THE INCOMING ARCTIC
FRONTAL BOUNDARY...WITH MAX TEMPS REACHING THE LOWER 30S IN VALLEY
AREAS...AND 20S ACROSS MOST HIGHER ELEVATIONS. FOR SAT NT/SUN
AM...AS THE ARCTIC BOUNDARY SINKS SOUTHWARD...TEMPS SHOULD FALL INTO
THE TEENS IN MOST AREAS...EXCEPT FOR SINGLE DIGITS ACROSS PORTIONS
OF THE ADIRONDACKS. ON SUNDAY...MAX TEMPS SHOULD GENERALLY ONLY
REACH THE 20S IN VALLEYS WITH TEENS ACROSS THE ADIRONDACKS. TEMPS
SHOULD THEN FALL INTO THE SINGLE DIGITS TO MID TEENS SUN NT...AND
THEN ONLY RISE INTO THE TEENS AND 20S FOR MONDAY...ALTHOUGH THERE IS
THE POTENTIAL FOR EVEN COLDER MAX TEMPS IF ENOUGH LOW LEVEL ARCTIC
AIR SEEPS SOUTHWARD INTO THE REGION IN THE WAKE OF THE WEEKEND
WAVE...AND IF SNOW FALLS INTO THIS COLD AND RELATIVELY DRY LOW LEVEL
AIR. EXPECT SINGLE DIGITS AND TEENS AGAIN FOR MON NT/TUE AM...WITH
TUE MAXES MAINLY IN THE 20S IN VALLEYS...AND TEENS ACROSS HIGHER
ELEVATIONS.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WEAK LOW PRESSURE WILL TRACK ACROSS SOUTHEAST CANADA TODAY. A COLD
FRONT TRAILING FROM THIS LOW WILL PASS THROUGH THE TAF SITES DURING
THE MID TO LATE MORNING HOURS...PRECEDED AND ACCOMPANIED BY SNOW
SHOWERS. SOME LAKE EFFECT SNOWBANDS COULD CONTINUE INTO EARLY THIS
AFTERNOON...BEFORE HIGH PRESSURE BRINGS A PERIOD OF MAINLY CLEAR
SKIES AND DIMINISHING WINDS TO THE TAF SITES FOR TONIGHT.
THE AFOREMENTIONED COLD FRONT WILL APPROACH FROM THE WEST...AND PASS
THROUGH THE TAF SITES BETWEEN ROUGHLY 14Z-17Z/WED. A BAND...OR
PERHAPS MULTIPLE THIN BANDS OF SNOW SHOWERS SHOULD ACCOMPANY AND
PRECEDE THIS FRONT. FOR NOW...HAVE INDICATED VCSH DURING THIS TIME
PERIOD FOR MOST TAF SITES. HOWEVER...SHOULD ANY SNOW SHOWERS PASS
THROUGH...BRIEF VSBY REDUCTIONS INTO MVFR/IFR WILL BE POSSIBLE.
BEHIND THE FRONT...MAINLY VFR CONDITIONS ARE EXPECTED FOR THE
AFTERNOON/EARLY EVENING. HOWEVER...WILL HAVE TO WATCH FOR ANY
RESIDUAL LAKE ENHANCED/EFFECT SNOW SHOWERS OR SNOW BANDS...WHICH
COULD IMPACT KGFL/KALB/KPSF INTO LATE AFTERNOON...AGAIN POSSIBLY
PRODUCING BRIEF VSBY REDUCTIONS INTO MVFR/IFR. VFR CONDITIONS ARE
EXPECTED FROM SUNSET...THROUGH 12Z/THU.
WINDS WILL INCREASE FROM THE SOUTHWEST TO WEST AHEAD OF THE FRONT TO
8-12 KT BY MID MORNING...THEN SHIFT INTO THE WEST TO NORTHWEST
BEHIND THE FRONT AND INCREASE TO 10-16 KT...WITH SOME GUSTS OF 25-30
KT POSSIBLE...ESP AT KALB AND KPSF WHERE WINDS COULD BE FURTHER
ENHANCED DUE TO THE FUNNELING EFFECTS DOWN THE MOHAWK VALLEY. WINDS
WILL GRADUALLY DECREASE FROM THE WEST/NORTHWEST TO 5-10 KT BY LATE
EVENING...AND THEN BECOMING LIGHT/VARIABLE AFTER MIDNIGHT.
OUTLOOK...
THURSDAY NIGHT: LOW OPERATIONAL IMPACT.BREEZY SLIGHT CHANCE OF SHSN.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN...SN.
&&
.HYDROLOGY...
NO HYDRO IMPACTS ARE EXPECTED ON THE MAIN STEM RIVERS THE NEXT 5
DAYS. AN ARCTIC AIR MASS WILL REMAIN ACROSS THE HYDRO SERVICE AREA
FOR THE ENTIRE WEEK WHICH WILL ALLOW ICE TO REFORM...THICKEN...AND
STRENGTHEN ON AREA RIVERS AND LAKES THROUGH THE WEEK.
LIGHT PRECIPITATION IS EXPECTED DURING THE WEEK...AND ANY THAT
DOES OCCUR WILL BE IN THE FORM OF SNOW SHOWERS OR LIGHT SNOW FROM
CLIPPER LOWS OR LAKE EFFECT.
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...NONE.
NY...LAKE EFFECT SNOW ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NYZ032-038.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/WASULA
NEAR TERM...11/NAS/WASULA
SHORT TERM...11
LONG TERM...KL
AVIATION...KL
HYDROLOGY...11/WASULA
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
936 AM EST Wed Feb 26 2014
.Update...The 12z KTAE sounding was nearly saturated up to 600mb
with deep west to southwest flow. The cold front as of 14z has
already advanced into SW GA and the Florida panhandle. Most
locations have already reached the max temp for today and temps
will either remain steady or slowly fall through this afternoon.
Rain continues to be widespread and PoPs were untouched. Thus far,
SCT TSTMS have stayed offshore so mention of TSTMS were removed
for all but the coastal areas and SE Big Bend.
.Prev Discussion [411 AM EST]...
.Near Term [Through Today]...
At 09z, a surface cold front extended from a weak low in SC,
southwest to near Albany GA, to near Destin FL, and then along much
of the rest of the LA-TX Gulf coast. Regional radars showed a fairly
large area of rain along and to the north of the surface cold front
from near the AL-GA state line westward to SE TX. The placement of
the rain relative to the surface front was suggestive of an anafront
structure, with rearward sloping ascent along the cold front through
the vertical. This is confirmed by WSW flow on area radar VWPs in
the 900-700mb layer, and from a glance at RAP isentropic charts.
Given the isentropic ascent in the lowest levels of the troposphere,
but a general lack of significant forcing aloft, it`s likely that
rain will continue to be forced in a shallow layer just above the
surface through the remainder of the day. Models are in fairly good
agreement on the timing of the best isentropic ascent and QPF. We
leaned towards the consensus of recent local and NCEP WRF runs. With
widespread rain expected, PoPs were raised to 100% for today pretty
much everywhere across the forecast area. The rain should be most
widespread (and heaviest) in the morning, with it tapering off and
clearing from NW-SE in the afternoon and early evening.
Looking at GOES blended precipitable water product, there is a large
plume of PWATS >150% of normal extending from the western parts of
our forecast area west into Texas. This deeper moisture will
continue to advect into the area today, and could support some
locally heavier rain. This will be especially true near the Gulf
coast - closer to the surface cold front as the strongest forcing
for ascent arrives this morning after sunrise. Maximum QPF from
convection allowing models (CAM) is focused around Gulf and Franklin
counties and is on the order of 2-3 inches. With the heaviest rain
likely to fall in the lower portions of river basins, and average
rainfall generally between 0.50 and 1.00 inches, we don`t anticipate
any significant flooding issues. Instability should be limited
enough to only support some general thunderstorms - updrafts should
be too weak to pose much of a severe weather concern.
&&
.Prev Discussion [411 AM EST]...
.Short Term [Tonight Through Friday]...
Rain will taper off from north to south this evening, but may not
clear completely from our Southeast FL Big Bend zones until Thursday
morning. As skies clear behind the rain, temps will tumble into the
30s except for coastal and southeastern sections of the Big Bend. A
light freeze is forecast along and north of an Albany to Dothan to
Crestview line. Maximum freeze durations in Coffee County AL will be
about 5 hours. Max temps will be about 10 degrees below normal on
Thursday and range from the mid 50s far northwest to Around 60
southeast. This will set the stage for a widespread light freeze
Thursday night that will impact most inland areas. Coastal locations
will hold at 40. Temps will moderate to within a few degrees of
normal on Friday with max temps ranging from the lower 60s north to
the mid to upper 60s southeast.
.Long Term [Friday Night Through Wednesday]...
On Friday NIGHT, a shortwave will be moving across the Mid
Atlantic states. Further to the west, a disturbance will be moving
onshore into central California. A vort max located over the Rockies
will propagate eastward in zonal flow bringing slight PoP chances
on Saturday, however this forcing appears to be weak and displaced
more to the north of our CWA. From here on the GFS and Euro really
diverge in their handling of the upcoming pattern. The GFS is more
aggressive in phasing a shortwave over western Mexico with a
shortwave rounding the base of a trough over Idaho. This combination
pushes a surface front through our area late Monday night into
Tuesday but quickly exits the area. The Euro meanwhile remains
less amplified keeping the flow aloft more zonal and bringing a
series of vort maxes through the area early next week. This will
cause a stalling of a surface front over our CWA, and with each
passing upper-level vort max another round of rain. Both agree
that Tuesday morning should be pretty wet but given the
uncertainty with which this front will exit we have tentatively
gone with 40 PoPs for Tuesday afternoon.
.Aviation...
[Through 12Z Thursday] We expect IFR CIGS at all terminals today
along with periods of mostly -RA. Some +RA with TS will be possible
closer to the Gulf coast, particularly at ECP and TLH. Some of the
+RA could reduce visibilities to around 1-3SM at times. Rain will
gradually clear out in the afternoon from NW-SE, with CIGS
gradually lifting through MVFR to VFR range by the evening and
continuing overnight.
.Marine...
A cold front will slip south across the waters today shifting winds
to offshore. Wind speeds behind the front will reach marginal small
craft advisory criteria across the western legs by midday. Advisory
conditions will be possible across the eastern zones tonight. Winds
will then drop below cautionary levels by midday Thursday as high
pressure builds toward the waters. Winds will remain below headline
criteria through the weekend as they gradually veer to the east and
then southeast.
.Fire Weather...
Widespread wetting rains are expected today, which will leave fuel
moisture rather high on Thursday. Some of the finer (smaller) fuels
(measured by 10-hr fuel moisture) could dry out as a much drier air
mass arrives for Thursday, but should not be sufficiently dry in
Florida or Georgia to create red flag conditions. In southeast
Alabama, red flag criteria includes 4+ hr durations of RH < 25%.
This looks achievable, but the wet fuels would likely preclude any
sort of critical fire weather conditions. For now, we will maintain
the Fire Weather Watch. It`s possible durations could be met again
on Friday in southeast Alabama, and by then smaller fuels would have
likely dried more substantially.
.Hydrology...
Periods of moderate rain today and tonight across the forecast
area will result in slight to modest rises on area rivers. The
Choctawhatchee River at Bruce is forecast to crest right at flood
stage from Thursday into Saturday. The Apalachicola River at
Blountstown is at its crest and is forecast to fall below flood
stage Thursday evening. The Aucilla River at Lamont is forecast to
reach flood stage Thursday night and crest Friday night. Storm
total rainfall through Thursday morning is forecast to be less
than an inch north of I-10 with a maximum of near two inches over
coastal sections of Gulf and Franklin Counties. With the greatest
totals falling in the lower stretches of the river basins, rises
will be confined mainly to FL.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 60 39 60 29 65 / 100 50 10 0 0
Panama City 63 39 58 36 62 / 100 50 10 0 0
Dothan 54 31 57 31 62 / 100 30 0 0 0
Albany 55 32 58 29 62 / 100 20 0 0 0
Valdosta 59 37 59 30 64 / 100 50 0 0 0
Cross City 65 44 61 30 67 / 100 60 20 0 0
Apalachicola 64 41 58 35 61 / 100 60 10 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...Fire Weather Watch from Thursday morning through Thursday
afternoon for Coffee-Dale-Geneva-Henry-Houston.
GM...Small Craft Advisory until 10 AM EST Thursday for Coastal waters
from Apalachicola to Destin FL out 20 NM-Waters from
Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
UPDATE...BARRY
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...BARRY/WALSH
AVIATION...LAMERS/BARRY
MARINE...WOOL FIRE
WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
411 AM EST Wed Feb 26 2014
.Near Term [Through Today]...
At 09z, a surface cold front extended from a weak low in SC,
southwest to near Albany GA, to near Destin FL, and then along much
of the rest of the LA-TX Gulf coast. Regional radars showed a fairly
large area of rain along and to the north of the surface cold front
from near the AL-GA state line westward to SE TX. The placement of
the rain relative to the surface front was suggestive of an anafront
structure, with rearward sloping ascent along the cold front through
the vertical. This is confirmed by WSW flow on area radar VWPs in
the 900-700mb layer, and from a glance at RAP isentropic charts.
Given the isentropic ascent in the lowest levels of the troposphere,
but a general lack of significant forcing aloft, it`s likely that
rain will continue to be forced in a shallow layer just above the
surface through the remainder of the day. Models are in fairly good
agreement on the timing of the best isentropic ascent and QPF. We
leaned towards the consensus of recent local and NCEP WRF runs. With
widespread rain expected, PoPs were raised to 100% for today pretty
much everywhere across the forecast area. The rain should be most
widespread (and heaviest) in the morning, with it tapering off and
clearing from NW-SE in the afternoon and early evening.
Looking at GOES blended precipitable water product, there is a large
plume of PWATS >150% of normal extending from the western parts of
our forecast area west into Texas. This deeper moisture will
continue to advect into the area today, and could support some
locally heavier rain. This will be especially true near the Gulf
coast - closer to the surface cold front as the strongest forcing
for ascent arrives this morning after sunrise. Maximum QPF from
convection allowing models (CAM) is focused around Gulf and Franklin
counties and is on the order of 2-3 inches. With the heaviest rain
likely to fall in the lower portions of river basins, and average
rainfall generally between 0.50 and 1.00 inches, we don`t anticipate
any significant flooding issues. Instability should be limited
enough to only support some general thunderstorms - updrafts should
be too weak to pose much of a severe weather concern.
.Short Term [Tonight Through Friday]...
Rain will taper off from north to south this evening, but may not
clear completely from our Southeast FL Big Bend zones until Thursday
morning. As skies clear behind the rain, temps will tumble into the
30s except for coastal and southeastern sections of the Big Bend. A
light freeze is forecast along and north of an Albany to Dothan to
Crestview line. Maximum freeze durations in Coffee County AL will be
about 5 hours. Max temps will be about 10 degrees below normal on
Thursday and range from the mid 50s far northwest to Around 60
southeast. This will set the stage for a widespread light freeze
Thursday night that will impact most inland areas. Coastal locations
will hold at 40. Temps will moderate to within a few degrees of
normal on Friday with max temps ranging from the lower 60s north to
the mid to upper 60s southeast.
.Long Term [Friday Night Through Wednesday]...
On Friday NIGHT, a shortwave will be moving across the Mid
Atlantic states. Further to the west, a disturbance will be moving
onshore into central California. A vort max located over the Rockies
will propagate eastward in zonal flow bringing slight PoP chances
on Saturday, however this forcing appears to be weak and displaced
more to the north of our CWA. From here on the GFS and Euro really
diverge in their handling of the upcoming pattern. The GFS is more
aggressive in phasing a shortwave over western Mexico with a
shortwave rounding the base of a trough over Idaho. This combination
pushes a surface front through our area late Monday night into
Tuesday but quickly exits the area. The Euro meanwhile remains
less amplified keeping the flow aloft more zonal and bringing a
series of vort maxes through the area early next week. This will
cause a stalling of a surface front over our CWA, and with each
passing upper-level vort max another round of rain. Both agree
that Tuesday morning should be pretty wet but given the
uncertainty with which this front will exit we have tentatively
gone with 40 PoPs for Tuesday afternoon.
&&
.Aviation...
[Through 06Z Thursday] Rain will quickly spread into the area in the
early morning hours - affecting all terminals. -RA should first
arrive at DHN/ECP around 09z, eventually reaching VLD around 12z. We
expect IFR CIGS to develop at all terminals prior to 14z, except ABY
where low end MVFR CIGS are expected. Some +RA with TS will be
possible closer to the Gulf coast, particularly at ECP and TLH. Some
of the +RA could reduce visibilities to around 1-3SM at times. Rain
will gradually clear out in the afternoon from NW-SE, with CIGS
gradually lifting through MVFR to VFR range by the evening.
&&
.Marine...
A cold front will slip south across the waters today shifting winds
to offshore. Wind speeds behind the front will reach marginal small
craft advisory criteria across the western legs by midday. Advisory
conditions will be possible across the eastern zones tonight. Winds
will then drop below cautionary levels by midday Thursday as high
pressure builds toward the waters. Winds will remain below headline
criteria through the weekend as they gradually veer to the east and
then southeast.
&&
.Fire Weather...
Widespread wetting rains are expected today, which will leave fuel
moisture rather high on Thursday. Some of the finer (smaller) fuels
(measured by 10-hr fuel moisture) could dry out as a much drier air
mass arrives for Thursday, but should not be sufficiently dry in
Florida or Georgia to create red flag conditions. In southeast
Alabama, red flag criteria includes 4+ hr durations of RH < 25%.
This looks achievable, but the wet fuels would likely preclude any
sort of critical fire weather conditions. For now, we will maintain
the Fire Weather Watch. It`s possible durations could be met again
on Friday in southeast Alabama, and by then smaller fuels would have
likely dried more substantially.
&&
.Hydrology...
Periods of moderate rain today and tonight across the forecast
area will result in slight to modest rises on area rivers. The
Choctawhatchee River at Bruce is forecast to crest right at flood
stage from Thursday into Saturday. The Apalachicola River at
Blountstown is at its crest and is forecast to fall below flood
stage Thursday evening. The Aucilla River at Lamont is forecast to
reach flood stage Thursday night and crest Friday night. Storm
total rainfall through Thursday morning is forecast to be less
than an inch north of I-10 with a maximum of near two inches over
coastal sections of Gulf and Franklin Counties. With the greatest
totals falling in the lower stretches of the river basins, rises
will be confined mainly to FL.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 60 39 60 29 65 / 100 50 10 0 0
Panama City 60 39 58 36 62 / 100 50 10 0 0
Dothan 54 31 57 31 62 / 100 30 0 0 0
Albany 54 32 58 29 62 / 100 20 0 0 0
Valdosta 58 37 59 30 64 / 100 50 0 0 0
Cross City 65 44 61 30 67 / 100 60 20 0 0
Apalachicola 64 41 58 35 61 / 100 60 10 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...Fire Weather Watch from Thursday morning through Thursday
afternoon for Coffee-Dale-Geneva-Henry-Houston.
GM...Small Craft Advisory from 11 AM this morning to 10 AM EST
Thursday for Coastal waters from Apalachicola to Destin FL
out 20 NM-Waters from Apalachicola to Destin FL from 20 to
60 NM.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...BARRY/WOOL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
236 AM EST WED FEB 26 2014
.SYNOPSIS...
A FRONT AND UPPER ENERGY WILL PROVIDE A CHANCE OF RAIN TODAY...THEN
FAIR...DRIER AND COOLER WEATHER EXPECTED THROUGH LATE WEEK. AN UPPER
DISTURBANCE WILL BRING A CHANCE OF SHOWERS FRIDAY NIGHT AND
SATURDAY. THE NEXT FRONT WILL AFFECT OUR REGION EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
SURFACE FRONT GENERALLY STRETCHED ACROSS THE CENTRAL FORECAST
AREA...STRETCHING WESTWARD INTO THE LOWER MISS VALLEY. THIS ALONG
WITH A SERIES OF SOUTHERN STREAM UPPER IMPULSES...AHEAD OF A
NORTHERN STREAM UPPER IMPULSE THAT WILL DIVE FROM THE CENTRAL PLAINS
INTO THE SE US TODAY...WILL PROMOTE SOME RAIN. LATEST HIGH
RESOLUTION MODELS INDICATE RAIN AREA TO OUR WEST WILL SHIFT
EAST...REACHING THE CSRA BEFORE DAYBREAK AND SPREADING EAST ACROSS
MOST OF THE FA THIS MORNING...MOVING OUT OF THE FA DURING THE
AFTERNOON. SLIGHT CHANCE THAT A LITTLE MELTING SNOW COULD MIX
WITH RAIN ACROSS THE NORTHERN FA...BUT CHANCES OF THAT APPEAR TOO
LOW TO INCLUDE IN THE FORECAST...PLUS ANY SNOW WOULD MELT ON
IMPACT WITH NO ACCUM.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
EXPECT CLEARING SKIES BY EARLY EVENING. A SECONDARY DRY FRONT WILL
MOVE SOUTH THROUGH THE REGION TONIGHT...FOLLOWED BY ANOTHER DRY
FRONT ROLLING THROUGH THURSDAY NIGHT...MAINTAINING A CONTINUED
INFLUX OF COOLER AND DRIER AIR. HIGH PRESSURE CENTER WILL BUILD IN
FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A WEAK SHORTWAVE TROUGH WILL BRING A CHANCE OF PRECIPITATION FRIDAY
NIGHT INTO EARLY SATURDAY. SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY
MORNING AS AN UPPER RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH
SUNDAY WITH DRY WEATHER EXPECTED. THE UPPER RIDGE WILL SHIFT EAST
MONDAY AS A TROUGH BUILDS OVER THE WESTERN CONUS. SOME MODEL
DIFFERNCES CONTINUE...BUT ECMWF AND GFS GENERALLY SUGGEST NEXT FRONT
WITH AVAILABLE ATMOSPHERIC MOISTURE TO AFFECT OUR REGION IN THE
MONDAY/TUESDAY TIME FRAME. GENERALLY BLENDED LATEST GUIDANCE WITH
ONGOING FORECAST.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD. HOWEVER...MODEL
INCONSISTENCIES LOWER THE CONFIDENCE AND THERE IS THE POSSIBILITY OF
A PERIOD OF MVFR CONDITIONS WEDNESDAY MORNING.
A COLD FRONT WILL SINK SOUTHWARD AND THROUGH THE AREA OVERNIGHT.
NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT DURING THE EARLY
MORNING HOURS. EXPECT AN INCREASE IN CLOUDINESS AND THE DEVELOPMENT
OF RAIN OVER MOST OF THE AREA DURING THE EARLY MORNING HOURS MAINLY
ASSOCIATED WITH A COUPLED H25 JET PATTERN. THE LATEST HRRR SHOWED
COVERAGE UPSTREAM INCREASING AND MOVING INTO THE FORECAST AREA
AROUND 10-12Z. 88D REGIONAL COMPOSITE ALREADY SHOWS SOME AREAS OF
LIGHT RAIN AS FAR EAST AT ALABAMA. CONFIDENCE IS LOW WITH THE
CEILING AND VISIBILITY FORECAST BECAUSE OF MODEL INCONSISTENCY. THE
NAM MOS INDICATED MVFR OR IFR CEILINGS. THE GFS MOS AND LAMP PLUS
SREF GUIDANCE INDICATED CONTINUED VFR CEILINGS AND VISIBILITIES. THE
22Z HRRR INDICATED MAINLY VFR CONDITIONS THROUGH 13Z. LEANED TOWARD
THE MORE OPTIMISTIC GUIDANCE BECAUSE OF THE H85 WESTERLY FLOW AND
THE INITIAL DRYNESS. ALSO...LOOKING BACK AT UPSTREAM OBS THEY ARE
MAINLY IN THE VFR CATEGORY. ALSO...A LACK OF SIGNIFICANT ISENTROPIC
LIFT SHOULD HELP KEEP RAIN MAINLY LIGHT AND LIMIT ITS RESTRICTION TO
VISIBILITY. THE NAM AND GFS SHOW UPPER-LEVEL LIFT SHIFTING EAST OF
THE AREA BETWEEN 16 AND 18Z. RAIN AND LINGERING LOWER CLOUDINESS
SHOULD DIMINISH DURING THIS TIME. AFTER 18Z...CLOUDINESS WILL
GRADUALLY BECOME BROKEN THEN SCATTERED BY 00Z. AFTER 00Z...WINDS
WILL BE GENERALLY REMAIN LIGHT WITH SOME SCATTERED HIGH CLOUDS.
EXTENDED AVIATION OUTLOOK...WITH HIGH PRESSURE OVER THE AREA THROUGH
THE REMAINDER OF THE WEEK...NOT SIGNIFICANT IMPACTS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1242 AM EST WED FEB 26 2014
.SYNOPSIS...
A GULF COAST LOW PRESSURE SYSTEM WILL MOVE EAST THROUGH GEORGIA
AND FLORIDA TONIGHT INTO WEDNESDAY BRINGING A CHANCE OF RAIN TO
OUR AREA. DRY AND COOLER WEATHER IS EXPECTED THURSDAY AND FRIDAY
WITH ANOTHER CHANCE OF RAIN EARLY SATURDAY WITH A FAST MOVING
SYSTEM.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
UPDATE...FORECAST REMAINS ON TRACK AS FRONT APPROACHES FROM THE
WEST. HAVE ADJUSTED POPS AND CLOUDS TO BETTER REPRESENT CURRENT
OBSERVATIONS WITH INCREASING CLOUDS AND CHANCES OF RAIN OVER THE
NEXT SEVERAL HOURS. BEST CHANCES OF RAIN WILL BE OVER THE SOUTHERN
MIDLANDS AND CSRA OVERNIGHT WITH RAIN SPREADING INTO THE CENTRAL
MIDLANDS DURING THE EARLY MORNING HOURS. RAINFALL AMOUNTS THROUGH
DAYBREAK ARE EXPECTED TO BE TWO TENTHS OF AN INCH OR LESS.
TEMPERATURES REMAIN ON TRACK FOR LOWER 40S FOR THE NORTHERN AND
WESTERN MIDLANDS WITH MID 40S TO AROUND 50 ELSEWHERE.
PREVIOUS DISCUSSION...CHANCES OF RAIN INCREASE LATE TONIGHT AS
BROAD UPPER TROUGH SINKS ACROSS THE GREAT LAKES AND OHIO VALLEY
REGION DRIVING A COLD FRONT THROUGH THE FORECAST AREA EARLY
WEDNESDAY MORNING BEFORE HIGH PRESSURE BUILDS IN AT THE SURFACE
BEHIND THE FRONT WEDNESDAY AFTERNOON. WESTERLY LOW LEVEL FLOW
AHEAD OF THE SHORTWAVE AND FRONT IS FORECAST TO BACK MORE
SOUTHWESTERLY THIS EVENING ALLOWING FOR ATMOSPHERIC MOISTURE TO
INCREASE WITH FLOW OFF THE WESTERN GULF OF MEXICO. HOWEVER...THE
TIME FRAME FOR SIGNIFICANT MOISTURE TO MOVE INTO THE REGION BEFORE
THE FRONT ARRIVES IS SHORT AND A LIMITING FACTOR DESPITE MODERATE
UPPER DYNAMICS ARRIVING AROUND THE 12Z TIME FRAME AS THE NORTHERN
AND SOUTHERN STREAM JETS COUPLE TO PROVIDE STRONG OMEGA AND UPWARD
VERTICAL MOTION OVER THE FORECAST AREA.
HAVE INCREASED POPS SLIGHTLY FROM PREVIOUS FORECAST...HIGHEST POPS
FROM THE CSRA ACROSS THE SOUTHEAST MIDLANDS LATE TONIGHT INTO
WEDNESDAY MORNING WITH A GRADIENT TO LOWER POPS TO THE NORTHWEST
WHERE MOISTURE WILL NOT BE AS GREAT. STILL FIGURE THE BEST TIME
FRAME FOR HIGHEST POPS WILL BE FROM 09Z-15Z WITH CHANCES OF RAIN
DECREASING FROM NORTHWEST TO SOUTHEAST THROUGH THE DAY WEDNESDAY.
LATEST 12Z NAM SOUNDINGS SUGGEST A MIX OF SNOW/RAIN POSSIBLE
ACROSS THE NORTHERN MIDLANDS WEDNESDAY MORNING WITH DEEP MOISTURE
INTO SNOW GROWTH ZONE AND NEAR SURFACE TEMPERATURES LIKELY IN THE
30S. CONFIDENCE IS LOW HOWEVER WITH LITTLE SUPPORT FROM
GFS...I.E. NO MOISTURE IN SNOW GROWTH ZONE. STILL THINK HIGHER
POPS WILL BE SOUTH OF THE NORTHERN MIDLANDS...BUT WILL INCLUDE
CHANCE SNOW/RAIN SHOWERS ACROSS NORTHERN LANCASTER COUNTY WHERE
PARTIAL THICKNESS SCHEMES FAVOR MIX.
CLOUDINESS LATE TONIGHT SHOULD KEEP TEMPERATURES FROM FALLING
SOMEWHAT...FAVOR WARMER MAV GUIDANCE. TEMPERATURES WILL BE MUCH
COOLER WEDNESDAY COMPARED TO TODAY WITH COLD ADVECTION TAKING
PLACE DURING THE DAY DESPITE SOME CLEARING SKIES BY AFTERNOON.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
WEDNESDAY NIGHT...THE LOW PRESSURE SYSTEM AND ALL ASSOCIATED
PRECIPITATION WILL BE WELL OFFSHORE BY WEDNESDAY NIGHT. COLD AIR
ADVECTION AND DECENT RADIATIONAL COOLING CONDITIONS WILL LEAD TO
BELOW NORMAL OVERNIGHT LOW TEMPERATURES...IN THE UPPER 20S NORTH
TO LOWER 30S SOUTH.
THURSDAY THROUGH THURSDAY NIGHT...A BROAD UPPER TROUGH WILL MOVE
OVER THE EASTERN CONUS ON THURSDAY PROMOTING WEST-NORTHWESTERLY
FLOW ALOFT. AT THE SURFACE...LOW PRESSURE OVER THE GREAT LAKES
REGION WILL BRING A DRY COLD FRONT THROUGH THE AREA. TEMPERATURES
WILL MAX OUT IN THE MID 50S TO NEAR 60 UNDER SUNNY SKIES. SURFACE
HIGH PRESSURE WILL SHIFT INTO THE OHIO VALLEY THURSDAY NIGHT
ALLOWING SURFACE WINDS TO ROTATE FROM WESTERLY TO NORTHEASTERLY.
MOSTLY CLEAR SKIES OVERNIGHT WILL SET THE STAGE FOR ANOTHER CHILLY
NIGHT WITH LOWS IN THE UPPER 20S TO NEAR 30.
FRIDAY THROUGH FRIDAY NIGHT...THE UPPER TROUGH WILL BE OFF THE
COAST BY FRIDAY WITH UPPER FLOW BECOMING ZONAL. SURFACE HIGH
PRESSURE WILL SHIFT OVER THE MID-ATLANTIC AND WEDGE INTO THE
FORECAST AREA FOR FRIDAY. TEMPERATURES WILL MAX OUT IN THE UPPER
40S NORTH TO MID 50S SOUTH. A WEAK SHORTWAVE TROUGH WILL BRING A
CHANCE OF PRECIPITATION FRIDAY NIGHT INTO EARLY SATURDAY. MOSTLY
CLOUDY SKIES OVERNIGHT WITH LOW TEMPERATURES ABOVE FREEZING IN THE
LOWER 30S TO NEAR 40.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
SHORTWAVE TROUGH WILL SHIFT EAST SATURDAY MORNING AS AN UPPER
RIDGE BUILDS OVER THE SOUTHEAST CONUS THROUGH SUNDAY WITH DRY
WEATHER EXPECTED. THE UPPER RIDGE WILL SHIFT EAST MONDAY AS A
TROUGH BUILDS OVER THE WESTERN CONUS. SIGNIFICANT TIMING
DIFFERENCES BETWEEN THE ECMWF AND GFS WITH THE NEXT SYSTEM
ARRIVING DURING THE MONDAY/TUESDAY TIME FRAME. THE ECMWF IS
A BIT QUICKER BRINGING THE SYSTEM THROUGH THAN THE GFS. BELOW
NORMAL MAX TEMPERATURES ON SATURDAY BUT OTHERWISE NEAR NORMAL
HIGHS IN THE 60S FOR THE REST OF THE EXTENDED. LATEST GUIDANCE HAS
CONTINUED TO TREND UP WITH TEMPERATURES FOR SUNDAY AND MONDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS DURING THE TAF PERIOD. HOWEVER...MODEL
INCONSISTENCIES LOWER THE CONFIDENCE AND THERE IS THE POSSIBILITY OF
A PERIOD OF MVFR CONDITIONS WEDNESDAY MORNING.
A COLD FRONT WILL SINK SOUTHWARD AND THROUGH THE AREA OVERNIGHT.
NORTHERLY WINDS WILL DEVELOP BEHIND THE FRONT DURING THE EARLY
MORNING HOURS. EXPECT AN INCREASE IN CLOUDINESS AND THE DEVELOPMENT
OF RAIN OVER MOST OF THE AREA DURING THE EARLY MORNING HOURS MAINLY
ASSOCIATED WITH A COUPLED H25 JET PATTERN. THE LATEST HRRR SHOWED
COVERAGE UPSTREAM INCREASING AND MOVING INTO THE FORECAST AREA
AROUND 10-12Z. 88D REGIONAL COMPOSITE ALREADY SHOWS SOME AREAS OF
LIGHT RAIN AS FAR EAST AT ALABAMA. CONFIDENCE IS LOW WITH THE
CEILING AND VISIBILITY FORECAST BECAUSE OF MODEL INCONSISTENCY. THE
NAM MOS INDICATED MVFR OR IFR CEILINGS. THE GFS MOS AND LAMP PLUS
SREF GUIDANCE INDICATED CONTINUED VFR CEILINGS AND VISIBILITIES. THE
22Z HRRR INDICATED MAINLY VFR CONDITIONS THROUGH 13Z. LEANED TOWARD
THE MORE OPTIMISTIC GUIDANCE BECAUSE OF THE H85 WESTERLY FLOW AND
THE INITIAL DRYNESS. ALSO...LOOKING BACK AT UPSTREAM OBS THEY ARE
MAINLY IN THE VFR CATEGORY. ALSO...A LACK OF SIGNIFICANT ISENTROPIC
LIFT SHOULD HELP KEEP RAIN MAINLY LIGHT AND LIMIT ITS RESTRICTION TO
VISIBILITY. THE NAM AND GFS SHOW UPPER-LEVEL LIFT SHIFTING EAST OF
THE AREA BETWEEN 16 AND 18Z. RAIN AND LINGERING LOWER CLOUDINESS
SHOULD DIMINISH DURING THIS TIME. AFTER 18Z...CLOUDINESS WILL
GRADUALLY BECOME BROKEN THEN SCATTERED BY 00Z. AFTER 00Z...WINDS
WILL BE GENERALLY REMAIN LIGHT WITH SOME SCATTERED HIGH CLOUDS.
EXTENDED AVIATION OUTLOOK...WITH HIGH PRESSURE OVER THE AREA THROUGH
THE REMAINDER OF THE WEEK...NOT SIGNIFICANT IMPACTS EXPECTED.
&&
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 PM MST TUE FEB 25 2014
.UPDATE...
ISSUED AT 1048 PM MST TUE FEB 25 2014
SNOW IS MOVING SOUTH AND DECREASING IN IN COVERAGE AND INTENSITY.
DRAMATIC CLEARING IS OCCURRING BEHIND THE SNOW BAND. SO LOWERED
MINS MORE.
UPDATE ISSUED AT 811 PM MST TUE FEB 25 2014
JUST COMPLETED ANOTHER UPDATE. BAND OF SNOW IS HOLDING TOGETHER
VERY WELL DESPITE WHAT EARLIER MODEL OUTPUT SAID. STRONG MID LEVEL
FRONTOGENESIS AND UPPER LEVEL DEFORMATION IS WORKING ITS WAY
ACROSS. SNOW IS LIGHT PROBABLY DUE TO THE VERY POOR THETA-E LAPSE
RATES BUT STILL IT IS GOING TO SNOW. SO RAISED POPS TO 100 PERCENT
FOR THE REST OF THE EVENING AS THIS BAND WORKS ITS WAY SOUTH. WITH
THE SLOWER PROGRESSION OF THE BAND AND LINGERING DYNAMICS...HAVE
KEPT THE POPS GOING FOR A FEW HOURS AFTER 06Z. OTHERWISE MADE
SLIGHT ADJUSTMENTS IN THE TEMPERATURES.
UPDATE ISSUED AT 604 PM MST TUE FEB 25 2014
NICE BAND OF SNOW STILL OVER THE FAR NORTH AT THIS TIME WITH A
SLOW SHIFT SOUTH. SOME UNCERTAINTY HOW FAR SOUTH THIS BAND WILL
GET AND HOW FAST IT WILL DO IT. MESOSCALE GUIDANCE IS INDICATING
THAT THIS BAND WILL THIN AND WEAKEN AS IT MOVES SOUTH. DO HAVE A
RIGHT REAR QUADRANT OF JET AND STRONG PV ANOMALY MOVING IN FROM
THE NORTHWEST. SO AM THINKING THE BAND WILL HOLD TOGETHER.
SO UPPED UP POPS TO DEFINITE IN THE NORTH AND INCREASED THE
REMAINING PORTION OF THE AREA SLIGHTLY. ALSO MADE A SLIGHT
ADJUSTMENT TO THE WINDS BASED ON THE HRRR. LOOKS LIKE THERE WILL
BE A QUICK AND DRAMATIC CLEARING TREND AFTER THE SNOW ENDS. WINDS
WILL BE LIGHT FOR A LITTLE WHILE BEFORE PICKING UP LATER IN THE
NIGHT. AM THINKING THAT WE HAVE THE POTENTIAL TO BE MUCH COLDER
THAN CURRENTLY INDICATED. SO DID MAKE A SLIGHT ADJUSTMENT COLDER
FOR THE NIGHT AND WILL CONTINUE TO WATCH THE TRENDS CLOSELY AND
SEE WHAT THE NEWER GUIDANCE WILL TELL ME.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 113 PM MST TUE FEB 25 2014
MAIN FOCUS IN THE SHORT TERM WAS TEMPERATURES TODAY THROUGH
TOMORROW AND PRECIPITATION THIS AFTERNOON AND OVERNIGHT. HIGH
TEMPERATURES THIS AFTERNOON WERE ADJUSTED SINCE SOME LOCATIONS
REACHED THEIR HIGHS AROUND 18/19Z. AFTER 18Z COLDER AIR MOVED INTO
NORTHERN LOCATIONS WHERE TEMPERATURES HAVE REMAINED FAIRLY
STAGNANT OR INCREASED BY A DEGREE OR TWO. PORTIONS OF NORTHWEST
KANSAS AND EASTERN COLORADO ALONG AND SOUTH OF I-70 HAVE SEEN
TEMPERATURES IN THE UPPER TEENS TO MID 20S...BUT THIS APPEARS TO
BE THE PEAK OF TODAY`S HIGH TEMPERATURES AS THE COLDER AIR BEGINS
TO MOVE IN. SNOW HAS DEVELOPED OVER SOUTHWEST NEBRASKA AND IS
MOVING INTO NORTHWEST KANSAS ASSOCIATED WITH A FAIRLY STRONG AREA
OF FRONTOGENESIS. AS THE SHORTWAVE TROUGH IN MONTANA CONTINUES TO
PUSH SOUTHEAST AND THE STRONG AREA OF FRONTOGENESIS MOVES
SOUTHEAST AND THEN SOUTH...SNOWFALL WILL CONTINUE THROUGH THE
EVENING OVER MOST OF THE TRI-STATE REGION. THIS WILL BE A QUICK
MOVING WAVE AND THE GFS...NAM...AND RAP ALL SHOW PRECIPITATION OUT
OF THE FORECAST AREA BY 06Z. SINCE THE SYSTEM MOVES QUICKLY...SNOW
ACCUMULATIONS WILL ONLY BE AROUND HALF AN INCH SOUTH AND EAST TO 2
INCHES NORTH AND NORTHWEST. CLOUD COVER WILL STICK AROUND A LITTLE
AFTER 06Z...WITH MOST OF THE CWA BEING CLEAR BY 15Z. LOWS TONIGHT
WILL DROP DOWN INTO THE SINGLE DIGITS AS HIGH PRESSURE SETTLES
INTO THE CWA. NORTHERN AREAS WILL SEE LOWS AROUND 1 DEGREE ABOVE
ZERO TO NEAR ZERO WHILE AREAS FURTHER SOUTH AND WEST WILL SEE LOWS
AROUND 5 TO 10 ABOVE ZERO.
AS SURFACE HIGH PRESSURE SLIDES EAST-SOUTHEAST...ANOTHER SHORTWAVE
TROUGH WILL MOVE THROUGH. NO PRECIPITATION IS EXPECTED WITH THE
NEXT TROUGH SINCE DRIER AIR MOVES IN SO HAVE KEPT THE FORECAST DRY
FOR TOMORROW. TEMPERATURES WILL BE DIVIDED WITH HIGHS OVER THE
NORTHERN HALF OF THE TRI-STATE REGION IN THE UPPER 30S TO NEAR 40
AND THE SOUTHERN HALF/SOUTH-SOUTHWEST PORTION OF THE TRI-STATE
REGION IN THE LOW TO MID 40S. MODELS MAY HAVE BEEN PICKING UP ON
THE SNOW COVER IN THE NORTHERN AREA OF THE CWA WHICH IS WHY THE
TEMPERATURES THERE ARE A BIT LOWER. USED A COMBINATION OF CONSALL
AND SREF FOR TOMORROW`S TEMPERATURES TO TREND THEM DOWNWARD IN THE
SOUTHERN PORTIONS OF THE CWA SINCE THEY SEEMED TO BE TOO HIGH TO
ACCOUNT FOR ANY SNOWFALL THOSE AREAS MIGHT RECEIVE TONIGHT. WEST
TO SOUTHWEST WINDS TOMORROW COULD ALSO BECOME BREEZY AROUND 18Z AS
THE SHORTWAVE TROUGH PASSES THROUGH AND DAYTIME MIXING
INCREASES...BUT ONLY HAVE SUSTAINED WINDS AROUND 10 TO 20 MPH
WITH GUSTS AROUND 25 TO 30 MPH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 224 AM MST TUE FEB 25 2014
WEDNESDAY NIGHT-THURSDAY...PROGRESSIVE SHORTWAVE RIDGE SHOULD HELP
KEEP DRY CONDITIONS IN PLACE THROUGH THESE PERIODS...WITH A SLIGHT
MODERATION OF THE AIR MASS OVER OUR CWA AS STATIONARY FRONT ALONG
FRONT RANGE LIFTS EAST WITH LEE TROUGH DEVELOPMENT. HIGH TEMPS
THURSDAY SHOULD BE NEAR NORMAL FOR WESTERN LOCATIONS (MID 40S TO
NEAR 50F)...WITH COOLER TEMPS IN THE MID/UPPER 30S FURTHER
NORTHEAST.
THURSDAY NIGHT-FRIDAY...NEXT IN A SERIES OF QUICK MOVING SHORTWAVE
TROUGHS WILL MOVE ACROSS THE REGION WITH ARCTIC AIR MASS DROPPING
BACK OVER WESTERN KS. BEST CHANCE FOR MEASURABLE SNOW APPEARS TO BE
LATE THURSDAY NIGHT THROUGH FRIDAY MORNING...WHEN MODELS ARE
ADVERTISING BETTER LARGE SCALE ASCENT. TIMING OF COLD FRONT IS A
LITTLE SLOWER WITH MAIN CAA FRIDAY AFTERNOON...WHICH MAY RESULT IN
QUITE A GRADIENT FROM THE NORTH-SOUTH OVER OUR CWA (LIKELY FALLING
TEMPS ACROSS THE NORTH).
FRIDAY NIGHT-TUESDAY...DESPITE DIFFERENCES IN THE LARGE SALE PATTERN
THROUGH THE EXTENDED PERIODS...MODELS HAVE COME INTO BETTER
AGREEMENT ON STUBBORN ARCTIC AIR MASS REMAINING IN PLACE OVER OUR
CWA...WITH ECMWF NOW TRENDING EVEN COLDER THAN THE LAST 3 RUNS OF
THE GFS. REGARDING LARGE SCALE PATTERN...ECMWF SHOWS MORE OF A
QUASI-ZONAL PATTERN WITH LOWER HEIGHTS SHIFTED SOUTH...WHILE GFS
SHOWS MORE OF A SPLIT FLOW PATTERN WITH THE NORTHERN STREAM HOLDING
MORE INFLUENCE OVER OUR CWA. EITHER SOLUTION FAVORS REINFORCING SHOTS
OF COLD ARCTIC AND AND PROLONGED BELOW NORMAL TEMPERATURES THROUGH AT
LEAST EARLY NEXT WEEK...ALONG WITH A SERIES OF QUICK MOVING
SHORTWAVES PASSING THROUGH THE REGION.
I TRENDED HIGH/LOW TEMPS DOWN TO ACCOUNT FOR THE COLDER PATTERN
CURRENT MODEL RUNS ARE ZEROING IN ON. EXPECTED CLOUD COVER
COMPLICATING HIGHS/LOWS...AND THERE ARE STILL DIFFERENCES BETWEEN
MODELS ON MAGNITUDE OF COOLING...SO I DID NOT FAVOR THE COLDEST
GUIDANCE DURING THIS UPDATE. THE TYPE OF AIR MASS CURRENTLY
ADVERTISED BY EVEN THE "WARMER" GFS WOULD SUPPORT OVERNIGHT LOWS IN
THE SINGLE DIGITS BELOW ZERO OVER PARTS OF OUR CWA DESPITE CLOUD
COVER (AND IF WE CLEAR OUT MUCH COLDER THAN THIS). CLOUDS COULD
LIMIT DAYTIME WARMING...AND ONGOING FORECAST OF TEENS-LOW 20S FOR
HIGHS MAY BE OPTIMISTIC. REGARDING PRECIP CHANCES...MANY OF THE
PERIODS IN THE EXTENDED HAVE SLIGHT CHANCE-CHANCE POPS...AND I DIDNT
SEE THE NEED TO REMOVE THESE BASED ON THE ACTIVE PATTERN ALOFT...AND
LINGERING BAROCLINIC ZONE ACROSS EASTERN COLORADO. BEST CHANCE FOR
MEASURABLE SNOW IN THESE PERIODS DOES APPEAR TO BE SAT-SAT NIGHT
WHEN A SLIGHTLY STRONGER SHORTWAVE TROUGH MOVES OUT OF THE SW US
ACROSS THE SOUTHERN PLAINS. THERE IS LITTLE IN THE WAY OF MOISTURE
RETURN/MOISTURE ADVECTION...SO ANY SNOWFALL WE SEE THROUGH THESE
PERIODS SHOULD BE ON THE LIGHT SIDE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1048 PM MST TUE FEB 25 2014
SNOW HAS ENDED OR IS ABOUT READY TO END AT BOTH SITES. A CLEARING
TREND IS UNDERWAY. ALTHOUGH IT WILL BE POSSIBLE FOR THE FIRST FEW
HOURS AT KMCK TO HAVE A BRIEF MVFR CEILING. OTHERWISE VFR CEILINGS
CAN BE EXPECTED THROUGH THE REST OF THE PERIOD WITH SHIFTING WINDS
AT 12 KNOTS OR LESS...HIGHEST BETWEEN 18Z AND 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...ALW/JSL
LONG TERM...DR
AVIATION...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
930 PM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT SERVING UP A COLD NIGHT. THE NEXT
UPPER LEVEL DISTURBANCE BRINGS SNOW SHOWERS SATURDAY. LOW PRESSURE
RIDING UP THE OHIO VALLEY WILL PRODUCE ACCUMULATING SNOW SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
HAVE DECIDED TO CANCEL WIND CHILL ADVISORY. TEMPS WILL BE VERY
COLD BUT WINDS HAVE DROPPED BELOW CRITERIA AND...WITH FURTHER
DECOUPLING...EXPECT MOST LOCATIONS TO GO CALM. UPDATED TEMPS AND
WINDS WITH LATEST GUIDANCE.
PREVIOUS DISCUSSION...
SNOW SHOWERS...SQUALLS...AND WINDS WILL SLOWLY DECREASE THIS
AFTERNOON AS MID LEVEL ENERGY EXITS E. RADAR SHOULD BE PCPN FREE
BEFORE 0Z. IF YOU BELIEVE THE LATEST HRRR SIMULATED REFLECTIVITY
BETWEEN 22-23Z.
A COLD NIGHT ON TAP FOR THE REGION. WIND CHILL VALUES FALL INTO
ADVISORY RANGE /-10 TO -20F/ BY THIS EVENING. H8 TEMPS DROP TO -24C
BY 12Z FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES.
WITH JUXTAPOSITION OF SFC ANTICYCLONE AND CONTINUED SNOWPACK ACROSS
NORTHERN COUNTIES WOULD NOT BE SURPRISED TO SEE MIN T FALL CLOSE TO
-10 ACROSS JEFFERSON WWRD TO FOREST. RIGHT NOW...SIDED WITH VALUES
AROUND -5F PER WINDS WILL STAY UP MOST OF THE NIGHT AND NOT BECOMING
LIGHT UNTIL AFTER MIDNIGHT.
BL TEMPS UNDERGO STRONG WARM ADVECTION /+10C IN 12HRS/ WHICH ALLOWS
FOR A NICE RECOVERY FROM SUB ZERO MORNING READINGS. WITH H8 TEMPS
AROUND -8C TO -14C COUPLED WITH FULL SUNSHINE WE STILL WON`T MANAGE
TO GET ABOVE 30F ANYWHERE. COMMUNITIES ALONG AND NORTH OF I-80 WILL
REMAIN IN THE TEENS. NOT THE BEST WAY TO CLOSE OUT FEBRUARY...BUT
GIVEN WE WERE -4F BELOW NORMAL FOR THE MONTH...THIS SHOULD NOT BE A
SURPRISE. IT APPEARS WE WON/T MAKE THE TOP 20 COLDEST FEBRUARY/S
AT PITTSBURGH BASED ON AVERAGE MEAN TEMPERATURE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
BENIGN WEATHER FRIDAY NIGHT HOWEVER MID AND UPPER LEVEL MOISTURE
WILL BE APPROACHING FROM THE WEST AHEAD OF THE NEXT SHORT WAVE
TROUGH. STILL EXPECT A LIGHT QPF EVENT SAT WITH AREA OF HIGHEST
POPS CONFINED ACROSS I-80 WHERE DYNAMICS ARE BETTER FOR INCREASED
SNOW SHOWER COVERAGE. NOT EXPECTING MORE THAN AN INCH OF
ACCUMULATION IN THE AFOREMENTIONED AREA.
BAROCLINIC ZONE STALLS OUT ALONG THE OHIO RIVER E ALONG THE MASON
DIXON LINE AS STEERING FLOW ALOFT ORIENTS PARALLEL TO IT. LOT OF
CLOUDS ARE PREDICTED THROUGH THE WEEKEND AS MOISTURE TRAIN EXISTS IN
THE WSW FLOW ALL THE WAY BACK TO THE SOUTHERN PLAINS. ANY PCPN SUN
MORNING WILL BE FLURRIES OR LIGHT SNOW SHOWERS...HOWEVER AS THE DAY
PROGRESSES MODEST ISENTROPIC UPGLIDE AND POSITIVE PRESSURE ADVECTION
WILL INCREASE AREAL COVERAGE OF SNOW AND INTENSITY. ECMWF SEEMS
HIGH WITH QPF AND SIDED MORE WITH GFS WHICH IS ALIGNED WITH
PREVIOUS FORECAST. ANY ACCUMULATIONS WILL BE LIGHT WITH A FEW
INCHES POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
QUESTIONS REMAIN REGARDING THE MUCH ASKED AND MUCH HYPED WINTER
STORM POISED TO AFFECT THE AREA EARLY NEXT WEEK. DIFFERENCES REMAIN
AMONGST NCEP SUITE WITH SLIGHT WOBBLING WITHIN ENSEMBLE MEANS.
GREATEST CERTAINTY AT THIS POINT IS SNOW NORTH OF I-70 WHERE THERMAL
PROFILES REMAIN COLD ENOUGH. EVEN NORTHERN MOST TRACK KEEPS PTYPE
ALL SNOW. FARTHER SOUTH IT REMAINS IFFY GIVEN PLACEMENT OF SURFACE
CYCLONE. LATEST RUN OF 12Z ECMWF HAS ARRIVED COOLER WITH SOUTHWARD
PLACEMENT OF LOW PRESSURE. IN SITUATIONS LIKE THIS SLIGHT
ADJUSTMENTS ARE PRUDENT TO KEEP FORECAST CONSISTENCY. GIVEN THIS
WINTER MOST WEATHER SYSTEMS HAVE OVER ACHIEVED AND TRENDED COLDER AS
THE EVENT DREW CLOSER...OUR CURRENT PROJECTION OF MOSTLY SNOW LOOKS
GOOD. DID ADD A PERIOD OF SNOW AND SLEET ACROSS THE FAR SOUTHERN
ROW OF COUNTIES SUNDAY NIGHT SINCE WARM LAYER ALOFT TEMPERATURE FROM
BOTH GFS AND ECMWF SUPPORT THIS.
DETERMINISTIC MODELS PULL PRECIP FROM THE FORECAST BY MONDAY
NIGHT...HAVE KEPT IN CHANCE POPS MONDAY NIGHT INTO TUESDAY MORNING
WITH ENSEMBLES INDICATING SNOW MAY HANG AROUND A BIT LONGER.
HIGH PRESSURE WILL MOVE OVER THE WESTERN GREAT LAKES BY TUESDAY...AND
SLOWLY DRIFT TO THE EAST ON WEDNESDAY...ALLOWING FOR DRY
CONDITIONS. A RETURN TO NORMAL TEMPERATURES IS NOT SEEN IN THE
EXTENDED FORECAST...WITH READINGS REMAINING 15 TO 20 DEGREES BELOW
NORMAL.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
CLOUDS ARE GRADUALLY DISSIPATING IN NORTHWEST FLOW WITH ONLY BKN VFR
CIGS ACROSS THE NORTH AND EASTERN PORTS. AS HIGH PRESSURE BUILDS IN
OVERNIGHT SKIES WILL CLEAR WITH NORTHWEST WINDS DIMINISHING BELOW 5
KTS OR BECOMING CALM. ONLY A FEW CIRRUS FRIDAY WITH A LIGHT
SOUTHEAST WIND DEVELOPING ON THE BACK SIDE OF HIGH PRESSURE.
.OUTLOOK..../THURSDAY NIGHT THROUGH TUESDAY/...
MULTIPLE DISTURBANCES ARE EXPECTED TO SPAWN WIDESPREAD RESTRICTIONS
SATURDAY THROUGH MONDAY GENERAL VFR EXPECTED TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
635 PM EST THU FEB 27 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN TONIGHT SERVING UP A COLD NIGHT. THE NEXT
UPPER LEVEL DISTURBANCE BRINGS SNOW SHOWERS SATURDAY. LOW PRESSURE
RIDING UP THE OHIO VALLEY WILL PRODUCE ACCUMULATING SNOW SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
LATEST UPDATE WILL INCLUDE THE REMOVAL OF POPS AND MENTION OF
FLURRIES ACROSS THE NORTH. HAVE UPDATED WINDS AND TEMPS WITH
LATEST GUIDANCE.
PREVIOUS DISCUSSION...
SNOW SHOWERS...SQUALLS...AND WINDS WILL SLOWLY DECREASE THIS
AFTERNOON AS MID LEVEL ENERGY EXITS E. RADAR SHOULD BE PCPN FREE
BEFORE 0Z. IF YOU BELIEVE THE LATEST HRRR SIMULATED REFLECTIVITY
BETWEEN 22-23Z.
A COLD NIGHT ON TAP FOR THE REGION. WIND CHILL VALUES FALL INTO
ADVISORY RANGE /-10 TO -20F/ BY THIS EVENING. H8 TEMPS DROP TO -24C
BY 12Z FRIDAY WITH HIGH PRESSURE BUILDING IN FROM THE GREAT LAKES.
WITH JUXTAPOSITION OF SFC ANTICYCLONE AND CONTINUED SNOWPACK ACROSS
NORTHERN COUNTIES WOULD NOT BE SURPRISED TO SEE MIN T FALL CLOSE TO
-10 ACROSS JEFFERSON WWRD TO FOREST. RIGHT NOW...SIDED WITH VALUES
AROUND -5F PER WINDS WILL STAY UP MOST OF THE NIGHT AND NOT BECOMING
LIGHT UNTIL AFTER MIDNIGHT.
BL TEMPS UNDERGO STRONG WARM ADVECTION /+10C IN 12HRS/ WHICH ALLOWS
FOR A NICE RECOVERY FROM SUB ZERO MORNING READINGS. WITH H8 TEMPS
AROUND -8C TO -14C COUPLED WITH FULL SUNSHINE WE STILL WON`T MANAGE
TO GET ABOVE 30F ANYWHERE. COMMUNITIES ALONG AND NORTH OF I-80 WILL
REMAIN IN THE TEENS. NOT THE BEST WAY TO CLOSE OUT FEBRUARY...BUT
GIVEN WE WERE -4F BELOW NORMAL FOR THE MONTH...THIS SHOULD NOT BE A
SURPRISE. IT APPEARS WE WON/T MAKE THE TOP 20 COLDEST FEBRUARY/S
AT PITTSBURGH BASED ON AVERAGE MEAN TEMPERATURE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
BENIGN WEATHER FRIDAY NIGHT HOWEVER MID AND UPPER LEVEL MOISTURE
WILL BE APPROACHING FROM THE WEST AHEAD OF THE NEXT SHORT WAVE
TROUGH. STILL EXPECT A LIGHT QPF EVENT SAT WITH AREA OF HIGHEST
POPS CONFINED ACROSS I-80 WHERE DYNAMICS ARE BETTER FOR INCREASED
SNOW SHOWER COVERAGE. NOT EXPECTING MORE THAN AN INCH OF
ACCUMULATION IN THE AFOREMENTIONED AREA.
BAROCLINIC ZONE STALLS OUT ALONG THE OHIO RIVER E ALONG THE MASON
DIXON LINE AS STEERING FLOW ALOFT ORIENTS PARALLEL TO IT. LOT OF
CLOUDS ARE PREDICTED THROUGH THE WEEKEND AS MOISTURE TRAIN EXISTS IN
THE WSW FLOW ALL THE WAY BACK TO THE SOUTHERN PLAINS. ANY PCPN SUN
MORNING WILL BE FLURRIES OR LIGHT SNOW SHOWERS...HOWEVER AS THE DAY
PROGRESSES MODEST ISENTROPIC UPGLIDE AND POSITIVE PRESSURE ADVECTION
WILL INCREASE AREAL COVERAGE OF SNOW AND INTENSITY. ECMWF SEEMS
HIGH WITH QPF AND SIDED MORE WITH GFS WHICH IS ALIGNED WITH
PREVIOUS FORECAST. ANY ACCUMULATIONS WILL BE LIGHT WITH A FEW
INCHES POSSIBLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
QUESTIONS REMAIN REGARDING THE MUCH ASKED AND MUCH HYPED WINTER
STORM POISED TO AFFECT THE AREA EARLY NEXT WEEK. DIFFERENCES REMAIN
AMONGST NCEP SUITE WITH SLIGHT WOBBLING WITHIN ENSEMBLE MEANS.
GREATEST CERTAINTY AT THIS POINT IS SNOW NORTH OF I-70 WHERE THERMAL
PROFILES REMAIN COLD ENOUGH. EVEN NORTHERN MOST TRACK KEEPS PTYPE
ALL SNOW. FARTHER SOUTH IT REMAINS IFFY GIVEN PLACEMENT OF SURFACE
CYCLONE. LATEST RUN OF 12Z ECMWF HAS ARRIVED COOLER WITH SOUTHWARD
PLACEMENT OF LOW PRESSURE. IN SITUATIONS LIKE THIS SLIGHT
ADJUSTMENTS ARE PRUDENT TO KEEP FORECAST CONSISTENCY. GIVEN THIS
WINTER MOST WEATHER SYSTEMS HAVE OVER ACHIEVED AND TRENDED COLDER AS
THE EVENT DREW CLOSER...OUR CURRENT PROJECTION OF MOSTLY SNOW LOOKS
GOOD. DID ADD A PERIOD OF SNOW AND SLEET ACROSS THE FAR SOUTHERN
ROW OF COUNTIES SUNDAY NIGHT SINCE WARM LAYER ALOFT TEMPERATURE FROM
BOTH GFS AND ECMWF SUPPORT THIS.
DETERMINISTIC MODELS PULL PRECIP FROM THE FORECAST BY MONDAY
NIGHT...HAVE KEPT IN CHANCE POPS MONDAY NIGHT INTO TUESDAY MORNING
WITH ENSEMBLES INDICATING SNOW MAY HANG AROUND A BIT LONGER.
HIGH PRESSURE WILL MOVE OVER THE WESTERN GREAT LAKES BY TUESDAY...AND
SLOWLY DRIFT TO THE EAST ON WEDNESDAY...ALLOWING FOR DRY
CONDITIONS. A RETURN TO NORMAL TEMPERATURES IS NOT SEEN IN THE
EXTENDED FORECAST...WITH READINGS REMAINING 15 TO 20 DEGREES BELOW
NORMAL.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
CLOUDS ARE GRADUALLY DISSIPATING IN NORTHWEST FLOW WITH ONLY BKN VFR
CIGS ACROSS THE NORTH AND EASTERN PORTS. AS HIGH PRESSURE BUILDS IN
OVERNIGHT SKIES WILL CLEAR WITH NORTHWEST WINDS DIMINISHING BELOW 5
KTS OR BECOMING CALM. ONLY A FEW CIRRUS FRIDAY WITH A LIGHT
SOUTHEAST WIND DEVELOPING ON THE BACK SIDE OF HIGH PRESSURE.
.OUTLOOK..../THURSDAY NIGHT THROUGH TUESDAY/...
MULTIPLE DISTURBANCES ARE EXPECTED TO SPAWN WIDESPREAD RESTRICTIONS
SATURDAY THROUGH MONDAY GENERAL VFR EXPECTED TUESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL ADVISORY UNTIL 7 AM EST FRIDAY FOR MDZ001.
OH...WIND CHILL ADVISORY UNTIL 7 AM EST FRIDAY FOR OHZ040-041.
PA...WIND CHILL ADVISORY UNTIL 7 AM EST FRIDAY FOR PAZ007>009-
013>016-022-023-074-076.
WV...WIND CHILL ADVISORY UNTIL 7 AM EST FRIDAY FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
400 AM EST WED FEB 26 2014
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION THROUGH MIDDAY.
LOW PRESSURE OVER THE GREAT LAKES WILL USHER IN CANADIAN AIR TO
THE REGION THROUGH FRIDAY. A WEAK DISTURBANCE WILL SLIDE ACROSS THE
AREA SATURDAY BEFORE A MORE POTENT LOW PRESSURE SYSTEM BEGINS TO
AFFECT THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 0830Z...NO SNOW REPORTED EAST OF THE ALLEGHENY FRONT...BUT
ECHOES ARE INCREASING AND THE CLOUD CEILING IS LOWERING LIKE A
BLANKET OVER THE AREA...PARTICULARLY EAST OF THE BLUE RIDGE. EXPECT
LIGHT TO MODERATE SNOW REPORTS TO BECOME COMMON 5-7AM WITH THE MOST
INTENSE RATES FROM 7-11AM BEFORE A QUICK CHANGEOVER TO SCATTERED
FLURRIES THROUGH MIDDAY...SOMEWHAT LIKE THE SNOW FROM TUESDAY (WITH
AN EARLIER ONSET AND MORE WIDESPREAD ACCUMULATIONS).
06Z HRRR HAS SHIFTED MAX OF SNOW (3-4") OVER WRN DC SUBURBS DOWN TO
RAPPAHANNOCK COUNTY. THE PREVIOUS SEVERAL RUNS HAD PUT A MAX OF 4+"
OVER CULPEPER COUNTY. ACCORDING TO THE 00Z GFS/ECMWF...THE JET
STREAM AXIS WILL BE OVER NRN SECTIONS OF THE CWA WITH THE SRN 2/3 IN
THE RIGHT ENTRANCE REGION THROUGH THE MORNING HOURS. UPPER TROUGH IS
STILL BROAD WITH NO DISCERNIBLE AXIS AT H5. NWLY FLOW IS EXPECTED TO
SPREAD OVER THE AREA MIDDAY THROUGH THE AFTERNOON WHICH WOULD
DOWNSLOPE AND LIMIT PRECIP TO SCATTERED FLURRIES.
TONIGHT...NLY FLOW AS SFC HIGH SPREADS IN ALONG MASON-DIXON LINE.
HOWEVER...A DEVELOPING LOW OVER THE GREAT LAKES BEGINS TO INFLUENCE
THE AREA BRINGING A SLY FLOW BY LATE TONIGHT. MIN TEMPS IN CLEAR
CONDITIONS GENERALLY MID TEENS.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
THE QUICK EXIT OF TODAY`S SYSTEM WILL ALLOW THE AREA TO CLEAR OUT
INTO EARLY THU. WINDS WILL ACTUALLY SWITCH BACK TO SLY FOR A BRIEF
PERIOD AS HIGH PRESSURE SQUEEZING IN BETWEEN THE EXITING SYSTEM AND
THE NEXT WAVE OF POLAR AIR. THE WED STORM SYSTEM WILL HAVE GRABBED
ESSENTIALLY ALL OF THE AVAILABLE MOISTURE FROM THE GULF
REGION...TAKING IT OFF THE COAST AHEAD OF THE APPROACHING UPPER VORT
FROM THE GREAT LAKES REGION.
WED NIGHT WILL BE A COLD NIGHT...BUT W/ THE ARRIVAL OF THIS LATEST
WAVE OF ARCTIC AIR...THU NIGHT WILL LIKELY BE A FEW DEG COLDER AND
SEVERAL DEG DRIER IN TERMS OF DEWPOINTS. A VERY DRY AIRMASS W/
DEWPOINTS BELOW ZERO ACROSS THE REGION AND ADEQUATE RADIATING TO
ALLOW TEMPS TO DROP WELL INTO THE TEENS AND SINGLE DIGITS. THE NIGHT
WILL ALSO START OFF W/ A STEADY NW BREEZE WHICH WILL ONLY FURTHER
DROP WIND CHILL VALUES INTO THE SINGLE DIGITS AND TOWARD ZERO. THIS
LATEST ANOMALOUSLY COLD AIRMASS THOUGH WILL BE ANOTHER QUICK-HITTER
W/ AN WELL ON ITS WAY TOWARD NEW ENGLAND THU NIGHT INTO EARLY FRI.
THE VORT`S EXIT WILL MEAN A SUBSTANTIAL DROP OFF IN WINDS ON
FRI...NEAR CALM EVEN DURING THE DAYTIME HRS. BUT THE ARCTIC AIRMASS
WILL HAVE LEFT SUCH DRY AIR IN ITS WAKE THE TEMPS WILL HAVE A TOUGH
TIME RECOVERING MUCH ABOVE THE M20S BY AFTN - EVEN UNDER AMPLE SUN.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WHILE TEMPS MAKE A SLOW/STEADY RECOVERING HEADING INTO THE
WEEKEND...ZONAL UPPER FLOW WILL BE ANYTHING BUT SLOW IN BRINGING IN
THE NEXT COUPLE OF LOW PRESSURE WAVES. THE FIRST WILL BE A WEAKLY
ORGANIZED SHORTWAVE W/ LITTLE MOISTURE INVOLVED AND ONLY BRIEFLY
BRINGING THE CHANCE FOR SOME LIGHT PRECIP DURING THE DAY DURING
MOVING OFF THE COAST. ANY PRECIP FALLING DURING THE MRNG HRS ON SAT
MAY BE SNOW BUT TEMPS ARE EXPECTED TO GRADUALLY RISE INTO THE M-U30S
BY AFTN...SO LIQUID PRECIP WILL BE MORE LIKELY W/ ANY RESIDUAL
SHOWERS.
FOCUS THEN TURNS TO A LARGE SCALE AND POTENT STORM SYSTEM DEVELOPING
ACROSS A BULK OF THE CONUS. MULTIPLE WAVES OF ENERGY WILL COMBINE
OVER THE WRN HALF OF THE COUNTRY SAT INTO SUN...PUSHING INTO THE
PLAINS AND EVENTUALLY TOWARD THE EAST COAST LATE SUN INTO MON. THE
WARM FRONT WILL FOR A TIME EXTEND ALL THE WAY FROM THE ROCKIES TO
THE ATLC COAST...SETTLING ALONG AND NORTH OF THE MASON-DIXON LINE AS
THE SYSTEM APR ROACHES. THE FREEZING LINE WILL ALSO BE HOVERING
AROUND THIS AREA SUN AND MON W/ PERIODIC WAVES OF LIGHT PRECIP
SLIDING BY DURING THE TIME. WILL MONITOR LONG TERM GUIDANCE TRENDS
FOR THE BULK OF EXPECTED PRECIP TO PASS OVER THE REGION...00Z RUNS
LOOKING LIKE LATE SUN INTO MON...W/ SOME LINGERING PRECIP INTO
TUE. THE BACK EDGE OF THE PRECIP MAY BE A RAIN/SNOW MIX W/ SNOW IN
THE NW PERIPHERY OF THE AREA W/ CURRENT TRENDS.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
SNOW ONSET 9 TO 11Z ACROSS THE TERMINALS WITH LIGHT TO MODERATE SNOW
THEN UNTIL 15-17Z AND FLURRIES EARLY THIS AFTERNOON. IFR CONDS IN
HEAVIEST PERIOD WITH LIFR IN MODERATE SNOW BY DEFINITION. VFR WITH
NWLY FLOW GUSTING TO 25 KT THIS AFTERNOON. NLY FLOW THIS
EVENING...SWINGING AROUND TO SLY BY DAYBREAK THURSDAY.
A DEEP AND COLD UPPER TROUGH WILL ENCOMPASS THE EAST COAST DURING
THE MIDDLE OF THE WEEK...BRINGING GUSTY WINDS TO THE AREA WED AND
THU. ONLY A BRIEF PERIOD OF SNOW POSSIBLE WED MRNG AS ONE WAVE OF
THIS SYSTEM MOVES ACROSS THE AREA BUT ONLY LIGHT AMTNS EXPECTED. THE
AREA WILL CLEAR OUT LATER IN THE DAY WED...STAYING DRY AND QUIET
INTO THE WEEKEND.
&&
.MARINE...
LIGHT EAST FLOW EARLY THIS MORNING BECOMES WEST AND INTENSIFIES
LATER THIS MORNING...WITH STRONG NWLY FLOW THIS AFTERNOON. SCA FOR
ALL WATERS STARTS AT 8AM...BUT AREAS OF SNOW WILL KEEP WINDS DOWN
PROBABLY UNTIL THE LATE MORNING. NWLY GUSTS OF 25 KT EXPECTED THIS
AFTERNOON. SCA CONTINUES FOR ALL BUT THE WESTERN TRIBUTARIES THROUGH
THE EVENING FOR NLY CHANNELING FLOW WITH GUSTS AROUND 20 KT. FLOW
ACTUALLY BECOMES SLY AFTER MIDNIGHT AS HIGH PRESSURE SETS UP
OFFSHORE.
WINDS WILL PICK BACK UP ON THU BUT NOT AS INTENSE AS WED...THOUGH
SMALL CRAFT CONDITIONS WILL BE POSSIBLE - POTENTIALLY GALE. WINDS
WILL DROP OFF FRI AND INTO THE WEEKEND W/ ONLY SOME BRIEF
CHANNELING INTO EARLY NEXT WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR DCZ001.
MD...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST
THURSDAY FOR MDZ501.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MDZ004>007-
009>011-013-014-016>018.
VA...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST
THURSDAY FOR VAZ503-504.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ037>040-
042-050>057-501-502.
WV...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 11 AM EST
THURSDAY FOR WVZ501-503-505-506.
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ501-505.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 11 PM EST THIS
EVENING FOR ANZ530>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 8 AM TO 6 PM EST THURSDAY FOR
ANZ530>543.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR ANZ535-536-538-542.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...BAJ
SHORT TERM...GMS
LONG TERM...GMS
AVIATION...BAJ/GMS
MARINE...BAJ/GMS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
246 AM EST WED FEB 26 2014
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION THROUGH MIDDAY.
LOW PRESSURE OVER THE GREAT LAKES WILL USHER IN CANADIAN AIR TO
THE REGION THROUGH FRIDAY. A WEAK DISTURBANCE WILL SLIDE ACROSS THE
AREA SATURDAY BEFORE A MORE POTENT LOW PRESSURE SYSTEM BEGINS TO
AFFECT THE REGION EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
QUICK UPDATE TO ADD GREENE AND ALBEMARLE TO THE ADVISORY. NO SNOW
REPORTED YET EAST OF THE ALLEGHENY FRONT THOUGH ECHOES SOUTH OF DC
ARE MOISTENING THE COLUMN. 05Z HRRR CONTINUES TREND OF RECENT HOUR
RUNS OF A SNOW MAX IN N-CNTRL VA CENTERED OVER CULPEPER COUNTY
LOCAL AMOUNTS OF 5 INCHES. IT DOES NOT TAKE MUCH IN A COLD AIRMASS
SUCH AS THIS TO GET SEVERAL INCHES FROM BANDS AND A WARNING MAY BE
NECESSARY IN THE NOWCAST PHASE. ELSEWHERE...DEPICTION IS
CONSISTENT OF A REDUCTION IN SNOW (LESS THAN AN INCH) BETWEEN THE
ALLEGHENY FRONT AND BLUE RIDGE AND 1-3 INCHES FROM THE CENTRAL VA
FOOTHILLS TO ACROSS THE BALTIMORE-WASHINGTON METRO AREA AND SRN
MD PRIMARILY BETWEEN 10 TO 16Z.
ADJUSTED BACK END OF PRECIP WITH FOR SCATTERED FLURRIES THAT
CONTINUE THROUGH THE EARLY AFTERNOON.
PREVIOUS...
LATEST ANALYSIS SHOWS SHORTWAVE ENERGY RACING THROUGH IN A ZONAL
FLOW ALOFT ACROSS THE MIDWEST INTO THE OHIO VALLEY. A STRONGER
SHORTWAVE OVER THE UPPER MIDWEST WILL QUICKLY DROP SOUTHEAST AND
SWING THROUGH OUR AREA LATE TONIGHT INTO WEDNESDAY MORNING. DEEP
SYNOPTIC LIFT IS EXPECTED IN THE RIGHT REAR ENTRANCE OF THE UPPER-
LEVEL JET...AND THIS CAN ALREADY BE SEEN IN THE INFRARED SATELLITE
IMAGERY WITH COOLING CLOUD TOPS ACROSS THE MIDWEST AND OHIO
VALLEY. RADAR TRENDS ARE ALSO INCREASING ACROSS THESE AREAS.
CLOUDS WILL LOWER AND THICKEN OVERNIGHT AND SNOW IS EXPECTED TO
OVERSPREAD THE AREA FROM WEST TO EAST AFTER MIDNIGHT. DESPITE
LIMITED MOISTURE...FORCING SHOULD BE STRONG ENOUGH FOR SNOWFALL
ACCUMULATIONS ACROSS MOST OF THE AREA. A WINTER WEATHER ADVISORY
REMAINS IN EFFECT FOR THE WASHINGTON AND BALTIMORE METROPOLITAN
AREAS AS WELL AS THE VIRGINIA PIEDMONT AND SOUTHERN MARYLAND.
LATEST GUIDANCE CONTINUES TO SHOW THAT THE BEST POTENTIAL FOR
MESOSCALE BANDING EXISTS ACROSS THESE AREAS WITH POTENT FN VECTOR
CONVERGENCE LINING UP WITH THE AREA OF MAXIMUM DENDRITIC SNOW
GROWTH AND SATURATED CONDITIONS. SNOWFALL ACCUMULATIONS WILL
AVERAGE BETWEEN ONE AND TWO INCHES ACROSS THESE AREAS...BUT
LOCALLY HIGHER AMOUNTS AROUND THREE INCHES ARE POSSIBLE DUE TO THE
POTENTIAL OF BANDING PRECIPITATION. TEMPS WILL BE PLENTY COLD FOR
SNOW...RANGING FROM THE TEENS IN THE MOUNTAINS TO THE 20S
ELSEWHERE EARLY WEDNESDAY MORNING. THEREFORE...SNOW COVERED ROADS
AND SLIPPERY CONDITIONS ARE EXPECTED DURING THE MORNING RUSH.
A WINTER WEATHER ADVISORY IS ALSO IN EFFECT FOR PORTIONS OF WEST
VIRGINIA ALONG AND WEST OF THE ALLEGHENY FRONT DUE TO AN UPSLOPE
COMPONENT TO THE LOW-LEVEL FLOW.
HIGH PRESSURE WILL APPROACH THE AREA WEDNESDAY AFTERNOON...BUT
BLUSTERY AND COLD CONDITIONS ARE EXPECTED AS NORTHWEST WINDS
INCREASE DUE TO A STRENGTHENING GRADIENT BETWEEN THE APPROACHING
HIGH AND LOW PRESSURE DEVELOPING WELL OF THE MID-ATLANTIC COAST.
FLURRIES ARE POSSIBLE WEDNESDAY AFTERNOON AS COLD ADVECTION
COMBINING WITH THE HIGHER SUN ANGLE CAUSES SOME INSTABILITY.
HOWEVER...NO ADDITIONAL SNOWFALL ACCUMULATION IS EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
COLD HIGH PRESSURE WILL BUILD INTO THE MIDDLE ATLANTIC REGION
WEDNESDAY NIGHT. GUSTY NORTHWEST WINDS WILL DIMINISH AND
TEMPERATURES WILL FALL BACK INTO THE TEENS IN MOST AREAS EXCEPT
0 TO 5 ABOVE ACROSS THE ALLEGHENY FRONT. HIGH TEMPERATURES WILL
AVERAGE WELL BELOW NORMAL THURSDAY AFTERNOON WITH ANOTHER COLD
FRONT BRINGING A REINFORCING SHOT OF ARCTIC AIR THURSDAY
AFTERNOON/EVENING. OVERNIGHT LOWS THURSDAY NIGHT WILL FALL BACK TO
THE LOWER TO MIDDLE TEENS AREA WIDE EXCEPT 0 ABOVE TO 5 BELOW ZERO
ACROSS THE ALLEGHENY FRONT. GUSTY NORTHWEST WINDS MAY LEAD TO A
PERIOD OF BELOW ZERO WIND CHILLS THURSDAY NIGHT OVER WESTERN
SECTIONS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL MOVE ACROSS THE REGION FRIDAY...MAKING IT TO THE
EAST COAST BY FRIDAY NIGHT. WINDS WILL BE LIGHT AND VARIABLE FRIDAY
THEN BECOME SOUTHERLY FRIDAY NIGHT. TEMPERATURES WILL BE ABOUT 15 TO
20 DEGREES BELOW NORMAL FRIDAY AND 5 TO 10 DEGREES BELOW NORMAL
FRIDAY NIGHT.
SOME UPPER LEVEL ENERGY WILL BRING A CHANCE FOR SOME RAIN OR SNOW
SHOWERS LATE FRIDAY NIGHT AND SATURDAY.
A STATIONARY FRONT WILL DEVELOP ALONG THE OHIO VALLEY AND INTO THE
MID-ATLANTIC REGION SUNDAY AND PERSIST INTO MONDAY. THIS FRONT WILL
BE THE FOCAL POINT OF RAIN OR SNOW...MAINLY SUNDAY NIGHT AND
MONDAY. THE EURO MODEL HAS A LOW PRESSURE SYSTEM FORMING ALONG
THIS FRONT AND MOVING NORTHEAST ALONG THE SHENANDOAH VALLEY TOWARD
PENNSYLVANIA AND NEW YORK. THE GFS MODEL HAS A LOW PRESSURE
SYSTEM FORMING ALONG THE FRONT...AS WELL...BUT TAKES THE LOW
FURTHER SOUTH AND EAST THAN THE ECMWF.
THESE DIFFERENCES MAKE IT DIFFICULT TO PINPOINT WHO WILL RECEIVE
RAIN AND WHO WILL RECEIVE SNOW. THERE IS AT LEAST A CHANCE OF EITHER
PRECIPITATION TYPE WITH A LIKELY POP OF RAIN OR SNOW MONDAY.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
CIGS/VSBYS WILL DETERIORATE EARLY WEDNESDAY MORNING AS BANDS OF
SNOW DEVELOP OVER THE TERMINALS. IFR CONDITIONS ARE EXPECTED
DURING THIS TIME. CIGS/VSBYS WILL IMPROVE LATE WEDNESDAY MORNING
AND AFTERNOON AS NORTHWEST WINDS USHER IN DRIER CONDITIONS.
HOWEVER...A FEW FLURRIES CANNOT BE RULED OUT WEDNESDAY AFTERNOON.
NORTHWEST WINDS WILL GUST AROUND 20 TO 25 KNOTS DURING THIS TIME.
VFR CONDITIONS EXPECTED WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.
GUSTY NORTHWEST WINDS OF 15 TO 25 KTS WILL IMPACT THE TERMINALS
THURSDAY AFTERNOON INTO THE EVENING. WINDS WILL DIMINISH DURING
THE NIGHT.
VFR CONDITIONS FRIDAY. MVFR CONDITIONS CAN`T BE RULED OUT WITH A
CHANCE OF RAIN OR SNOW FRIDAY NIGHT THROUGH MONDAY. IF IFR
CONDITIONS DO EXIST...THERE IS A BETTER CHANCE SUNDAY NIGHT INTO
MONDAY ALONG A STATIONARY FRONT AND A DEVELOPING LOW PRESSURE
SYSTEM.
&&
.MARINE...
A SHORTWAVE WILL PASS THROUGH THE WATERS WEDNESDAY
MORNING...TRIGGERING A PERIOD OF SNOW. NW FLOW 15-20 KT SUSTAINED
BEHIND THE FRONT. SCA IN EFFECT FOR WED...CONTINUING FOR NLY FLOW
OVER ALL BUT THE WRN TRIBS WEDNESDAY EVENING.
A COLD FRONT WILL PUSH THROUGH THE WATERS ON THURSDAY BRINGING THE
LIKELIHOOD OF SCA CONDITIONS TO ALL OF THE WATERS. WINDS WILL FALL
BELOW SCA LEVELS BY THURSDAY NIGHT.
NO MARINE HAZARDS EXPECTED FRIDAY THROUGH SUNDAY. SMALL CRAFT
ADVISORIES SUNDAY NIGHT AND MONDAY WOULD DEPEND ON THE POSITION OF
A STATIONARY FRONT AND THE TRACK OF AN ATTACHED LOW PRESSURE
SYSTEM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR MDZ004>007-
009>011-013-014-016>018.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR VAZ037>040-
042-050>057-501-502.
WV...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR WVZ501-505.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 11 PM EST THIS
EVENING FOR ANZ530>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR ANZ535-536-538-542.
&&
$$
UPDATE...JACKSON
PREVIOUS...BJL/KRW/KLW/HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 400 PM EST TUE FEB 25 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A FAMILIAR PATTERN
FEATURING A DEEP UPR TROF OVER ERN NAMERICA DOWNSTREAM OF A RDG
ALONG THE W COAST. SHRTWV EMBEDDED IN THE NW FLOW IS STREAKING SEWD
THRU ONTARIO JUST N OF LK SUP. COLD FNT ASSOCIATED WITH THIS
DISTURBANCE HAS PASSED THRU THE CWA...AND H85 TEMPS AS LO AS -25C TO
-28C ARE PUSHING INTO UPR MI IN THE LLVL W FLOW. ALTHOUGH THERE IS A
GOOD DEAL OF ICE ON LK SUP...AREAS OF OPEN WATER OVER THE FAR WRN LK
AND OVER THE SCENTRAL E OF THE KEWEENAW HAVE ALLOWED A GOOD DEAL OF
LK CLD/SOME -SHSN TO FORM IN THE LLVL CAD. THE LK CLDS/SHSN APPEAR
TO BE MOST WDSPRD OVER THE NE HALF OF THE AREA CLOSER TO THE SHRTWV
PASSING THRU ONTARIO/ACCOMANPANYING DYNAMIC SUPPORT AND DEEPER MSTR.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE LK EFFECT CLD/SHSN
TRENDS AND TEMPS/NEED FOR WIND CHILL HEADLINES.
LATE THIS AFTN/TNGT...AS THE H925 FLOW VEERS MORE TO THE NW THRU 00Z
IN THE WAKE OF SHRTWV PASSING BY TO THE N...EXPECT LK EFFECT
CLDS/SHSN TO SPREAD FARTHER TO THE S AND INLAND IN THE PRESENCE OF
LENGTHENING DAYTIME HEATING DESPITE DNVA/DEEP LYR QVECTOR DVGC IN
THE WAKE OF THE SHRTWV PASSAGE. H85 THERMAL TROF WITH TEMPS DOWN TO
-28/-29C IS FCST TO SHIFT THRU THE CWA BTWN 06Z-12Z AS THE LLVL FLOW
BACKS TO THE W BTWN SFC HI PRES SINKING TOWARD THE MID MS RIVER
VALLEY AND NEXT VIGOROUS SHRTWV DROPPING SEWD THRU SCENTRAL CANADA.
WITH A PERIOD OF LARGER SCALE QVECTOR DVGC...EXPECT CLRG OVER THE
INTERIOR...ALLOWING SFC TEMPS TO FALL WELL BLO ZERO AND INTO THE
TEENS BLO ZERO AT SOME PLACES UNDER DRY AIRMASS WITH PWAT UNDER 0.10
INCH. ALTHOUGH THERE ARE QUESTIONS AS TO WHETHER SFC WINDS WL
CONSISTENTLY SATISFY THE 10 MPH SPEED THRESHOLD FOR A WIND CHILL
ADVY...PLAN TO ISSUE AN ADVY FOR THE COLDER NW HALF OF THE CWA WITH
FAIRLY SHARP PRES GRADIENT/H925 WINDS IN THE 20-30KT RANGE UNDER H85
THERMAL TROF ENHANCING MIXING. LK EFFECT CLDS/-SHSN WL SHIFT FM THE
NW WIND SN BELTS BACK INTO AREAS IMPACTED BY W WINDS LATE TNGT.
ABSENCE OF DGZ WITHIN VERY COLD AIRMASS AND ICE COVER WL LIMIT SN
ACCUMS.
WED...AREA OF DEEP LYR QVECTOR CNVGC IN ADVANCE OF SHRTWV/SFC LO
DIGGING SEWD THRU NW ONTARIO WL OVERSPREAD UPR MI NW-SE BY EARLY
AFTN. IN THE ABSENCE OF ANY SGNFT MSTR INFLOW...SUSPECT DRYNESS OF
ANTECEDENT AIRMASS WL BE A SGNFT IMPEDIMENT TO OUTBRREAK OF PCPN. AS
THE FLOW SHIFTS TO THE SW...THERE IS POTENTIAL FOR SOME LK
MOISTENING/ENHANCEMENT OFF OF LK MI. BUT EXTENSIVE/GROWING ICE COVER
OVER THE N HALF OF LK MI WL TEND TO MITIGATE THIS IMPACT. TENDED
TOWARD THE HIER CHC/LIKELY POPS OVER THE NE HALF OF THE CWA TOWARD
SHARPER ISENTROPIC ASCENT ON THE 270K SFC /NEAR H7/ AND ALSO LATE IN
THE DAY OVER THE W WITH EXPECTED ARRIVAL OF ENHANCED LLVL CNVGC
ASSOCIATED WITH COLD FNT ATTENDANT TO CLIPPER LO REACHING NE LK SUP
BY 00Z THU.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 416 AM EST WED FEB 26 2014
AT 12Z THURSDAY THE MAIN 500MB LOW WILL BE SET UP FROM S HUDSON BAY
THROUGH N LAKE HURON...WITH QUICK NW FLOW AND SEVERAL ELONGATED
DISTURBANCES STILL MOVING THROUGH UPPER MI. THE STRONG WINDS THAT
WILL STILL BE AROUND AT DAYBREAK THURSDAY ARE STILL EXPECTED TO
DIMINISH PRETTY QUICKLY DURING THE DAY...WITH THE WEAKENING PRESSURE
GRADIENT AS THE SFC LOW PUSHES ACROSS THE S ONTARIO/QUEBEC BORDER BY
18Z...AND THE STRONG HIGH OVER THE DAKOTAS SHIFTS TO MN AND IA WHICH
WILL ALLOW FOR RIDGING OVER THE W HALF OF THE CWA. MOMENTUM TRANSFER
FALLS BELOW 25KTS AT IWD AROUND 15Z...CMX AT 18Z...1-2HRS LATER AT
SAW...AND AROUND 21Z AT P53. WIND CHILL WARNINGS/ADVISORIES WILL
CONTINUE UNTIL 17 OR 18Z.
CONFIDENCE IN HIGH SNOW AMOUNTS TO POST ANYTHING MORE THAN WINTER
WEATHER ADVISORIES IS LOW GIVEN THE SIGNIFICANT ICE ACROSS LAKE
SUPERIOR. HAS BEEN AMAZING TO SEE HOW QUICKLY NEW ICE HAS BEEN ABLE
TO FORM IN OUR COLD AIR OVER THE PAST 24HRS. WINTER WEATHER ADVISORY
WILL LINGER THROUGH MID-LATE MORNING ACROSS THE KEWEENAW
PENINSULA...AND MID AFTERNOON FOR ALGER/N. SCHOOLCRAFT/LUCE
COUNTIES. MAY NEED TO INCORPORATE FAR N AND E MQT COUNTY INTO WINTER
WEATHER ADVISORY FOR BLOWING/DRIFTING SNOW. THE WORST CONDITIONS ON
M-26 BETWEEN MQT AND MUNISING WILL LIKELY BE 10-18Z THURSDAY.
RECORD BREAKING LOW-HIGH TEMPERATURES THURSDAY STILL LOOK
REASONABLE. 850MB TEMPS OF -30 TO -33C WILL LINGER OVERHEAD THROUGH
THE DAY...WITH -36 TO -38C OVER CENTRAL ONTARIO. AS NOTED IN
PREVIOUS DAYS...THESE VALUES ACROSS THE CWA ARE SIMILAR TO 850MB
TEMPS FROM JANUARY 27TH AND HIGHS THAT DAY WERE IN THE SINGLE DIGITS
BELOW ZERO OVER THE WEST...AND AT OR JUST ABOVE FREEZING OVER THE
EAST. ALL-TIME COLDEST HIGH TEMP RECORDS FOR FEB 27TH ARE GENERALLY
IN THE MID SINGLE DIGITS ABOVE ZERO (WITH AT LEAST 6 DATING BACK
BEFORE 1925).
LOOK FOR EXTREMELY COLD TEMPERATURES THURSDAY NIGHT AS THE SFC HIGH
SINKS TO S WI AND IL BY 00Z...OVER LOWER MI THROUGH THE OHIO VALLEY
AT 06Z FRIDAY...AND FINALLY ACROSS THE LOWER GREAT LAKES/MID
ATLANTIC BY 12Z FRIDAY. WITH THE SFC RIDGE OVERHEAD MOST OF THE
NIGHT...EXPECT LIGHT WINDS. CLOUDS COULD KEEP TEMPS FROM FALLING TOO
LOW...PARTICULARLY OVER THE N HALF OF THE CWA. THE GFS AND NAM STILL
HAVE PLENTY OF LLV MOISTURE STUCK BELOW 850MB...WITH ADDITIONAL MID
CLOUDS LIKELY SLIDING IN OVERNIGHT FROM THE W OVER THE FAR N. THE
BAND OF MID CLOUDS S WILL LIKELY REMAIN JUST TO THE S THROUGH 12Z
FRIDAY. ALTHOUGH TEMPERATURES WILL BE VERY LOW /ONCE AGAIN POSSIBLY
RECORD BREAKING/...WIND CHILLS WILL NOT BE AS LOW...AND
WARNINGS/ADVISORIES WILL LIKELY NOT BE POSTED DUE TO THE LIGHT WINDS.
THE CHANCES FOR LIGHT SNOW WILL GREATLY DIMINISH THURSDAY NIGHT INTO
EARLY FRIDAY...BEFORE THE NEXT SYSTEM SLIDES IN FROM THE W-SW WITH
SCATTERED SNOW/SNOW SHOWERS DEVELOPING OVER MAINLY CENTRAL/E UPPER
MI DURING THE DAY FRIDAY. EXPECT S-SSW WINDS AHEAD OF THE LOW
SHIFTING FROM THE PLAINS STATES AT 12Z FRIDAY WILL DEEPEN SLIGHTLY
AS IT PUSHES ACROSS W UPPER MI/LAKE SUPERIOR AT 00Z SATURDAY...AND E
OF LAKE SUPERIOR/UPPER MI BY 12Z SATURDAY. THE S-SSW SHOULD RESULT
IN LAKE ENHANCED SNOW E OF ESC ALONG LAKE MI FRIDAY AFTERNOON/FRIDAY
EVENING. WILL NOT GO TOO HIGH WITH POPS AT THIS TIME...BUT POPS MAY
NEED TO BE INCREASED S CENTRAL AND E ALONG THE LAKE MI BORDER AS
FCST MODELS ARE STARTING TO ALIGN TO A COMMON THEME. LITTLE TO NO
SNOW IS EXPECTED FAR W.
STRONGER HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS
SATURDAY WILL SLOWLY SLIDE OVER THE UPPER GREAT LAKES THROUGH MUCH
OF THE REST OF THE PERIOD. LAKE EFFECT SNOW SHOWERS ACROSS N UPPER
MI WILL GREATLY DEPEND ON THE AMOUNT OF ICE COVER...BUT WITH
SIGNIFICANT ICE LIKELY REMAINING...KEPT POPS MAINLY IN THE SLIGHT
CHANCE CAT THROUGH THE REST OF THE PERIOD. NO SIGNIFICANT WARM UP
EXPECTED TO NORMAL VALUES ANTICIPATED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 634 PM EST TUE FEB 25 2014
WINDS BEGINNING TO ABATE SLIGHTLY AT ALL THREE TAF SITES THIS
EVENING. WINDS ARE TO GRADUALLY DIMINISH OVERNIGHT AS THEY BACK TO
THE SSW/SW BY DAYBREAK...AND THEN WILL PICK UP AS THE MORNING
PROGRESSES...WITH GUSTS TO 22-23KTS COMMON DURING THE LATE MORNING
AND AFTERNOON HOURS. AT KCMX...LIFR/IFR VISIBILITIES DUE TO BRIEF
LES SNOW BANDS AND GUSTY WINDS CHANNELED THROUGH THE TERRAIN THERE
WILL EVENTUALLY IMPROVE AFTER 6Z AS WINDS DIMINISH AND DRIER AIR
WORKING IN FROM THE WEST DIMINISHES LES. OTHERWISE...MVFR/VFR
CONDITIONS PREVAIL AT KIWD AND KSAW WITH MVFR DEVELOPING AT KCMX BY
9Z...AND WILL CONTINUE THROUGH THE FORECAST. IFR VISIBILITY
CONDITIONS MAY REDEVELOP AT KCMX WEDNESDAY AFTERNOON AS WINDS SHIFT
BACK TO THE WEST AND PICK UP AND LES REDEVELOPS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EST TUE FEB 25 2014
NW WINDS UP TO 25-30 KTS LATE TODAY UNDER SHARP PRES GRADIENT
BETWEEN SFC HI OVER THE NCENTRAL PLAINS AND LO PRES IN EASTERN
ONTARIO WILL SLOWLY BACK TO THE SW ON WED AS THE HI MOVES INTO THE
MID MS RIVER VALLEY AND ANOTHER LO PRES SYSTEM DIVES SE INTO NW
ONTARIO. THERE MAY BE SOME GALE FORCE GUSTS TO 35 KTS OVER THE W
HALF OF THE LAKE WHERE FUNNELING OF THIS FLOW RESULTS IN SPEED
ENHANCEMENT. ONCE THE LO SHIFTS TO THE E OF THE LAKE ON WED NIGHT
AS THE PRES GRADIENT TIGHTENS AGAIN E OF HI PRES MOVING INTO THE
NORTHERN PLAINS...N GALES UP TO 35-45 KTS WILL DEVELOP OVER THE
ENTIRE LAKE. THE CLOSER APPROACH OF THE HI CENTER AND WEAKER PRES
GRADIENT WILL CAUSE THE GALES TO DIMINISH W TO E ON THU. ISSUED A
GALE WATCH FOR THE ENTIRE LAKE. EXPECT WINDS UNDER 25 KTS THE REST
OF THE FORECAST PERIOD WITH A RELATIVELY WEAK PRES GRADIENT
DOMINATING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING FROM 3 AM EST /2 AM CST/ TO NOON EST /11 AM
CST/ THURSDAY FOR MIZ001>005-009>011-084.
WIND CHILL ADVISORY UNTIL 10 AM EST /9 AM CST/ THIS MORNING FOR
MIZ001>005-009>011-084.
WINTER WEATHER ADVISORY FROM 2 AM TO 3 PM EST THURSDAY FOR
MIZ006-007-085.
WIND CHILL ADVISORY FROM 6 AM EST /5 AM CST/ TO NOON EST /11 AM
CST/ THURSDAY FOR MIZ006-007-012>014-085.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 11 AM EST
THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING FROM 1 AM TO 1 PM EST THURSDAY FOR LSZ243>245-
248>251-264>267.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 8 AM EST
/7 AM CST/ THURSDAY FOR LSZ240>242-263.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 6 AM EST
/5 AM CST/ THURSDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
300 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
MAIN FORECAST CONCERN IN THE SHORT TERM IS STRONG WINDS AND THE
RESULTING BLOWING/DRIFTING SNOW EXPECTED ACROSS THE AREA THROUGH
THIS EVENING. LATEST SURFACE ANALYSIS AND OBS SHOW THE COLD FRONT
MOVING THROUGH THE NORTH HALF OF THE FORECAST AREA AT THE CURRENT
TIME... WITH A NICE WIND SHIFT FROM SOUTHWEST TO NORTHWEST BEHIND
THE FRONT. WE/RE SEEING STRONG SOUTHWEST WINDS... SUSTAINED NEAR
20KT WITH GUSTS TO AROUND 30KT AHEAD OF THE FRONT... AND NORTHWEST
WINDS OF AROUND 25KT WITH GUSTS OF 35KT IMMEDIATELY BEHIND THE
FRONT. HOWEVER... FORECAST SOUNDINGS FROM THE RAP AND NAM CONTINUE
TO SUGGEST THE BEST MIXING WITH POST FRONTAL COLD ADVECTION AND
SUBSIDENCE WILL OCCUR DURING THE EARLY EVENING ACROSS MOST OF THE
AREA... WITH 00-05Z LOOKING LIKE PRIME TIME FOR STRONG WINDS AND
POTENTIAL BLIZZARD CONDITIONS. THE HOPWRF MATCHES UP WITH THIS
TIMING QUITE WELL... AND HAS ENSEMBLE MEAN SUSTAINED WINDS OF AROUND
30 MPH AND GUSTS WELL IN EXCESS OF 40 MPH FOR A PERIOD OF SEVERAL
HOURS. LOCATIONS WHICH WILL SEE THE GREATEST IMPACT STILL LOOK TO BE
THE OPEN AREAS OVER THE WESTERN AND SOUTHERN PART OF THE AREA...
WHERE THE COMBINATION OF DEEP SNOW... STRONG WINDS... AND FAVORABLE
TERRAIN SHOULD LEAD TO WIDESPREAD LOW VISIBILITY AND SIGNIFICANT
DRIFTING SNOW. SOME LIGHT SNOW AND FLURRIES WILL SLIP THROUGH THE
NORTH/NORTHEAST PORTION OF THE AREA THROUGH THIS EVENING... BUT ANY
ACCUMULATION WILL BE VERY MINOR GIVEN THE EXTREMELY LIMITED MOISTURE
AHEAD OF THE SHORTWAVE AND COLD FRONT. THE PRESSURE GRADIENT LOOKS
TO QUICKLY RELAX OVERNIGHT INTO THURSDAY MORNING... SO WE SHOULD SEE
THE BLOWING/DRIFTING SETTLE DOWN FAIRLY QUICKLY AFTER MIDNIGHT. WILL
KEEP THE GOING HEADLINES IN PLACE... AS WELL AS THE TIMING... WHICH
STILL LOOKS TO ENCAPSULATE THE ENTIRETY OF THE EVENT. HOWEVER...
WIND CHILLS WILL BE PLUMMETING OVERNIGHT AS COLDER AIR ARRIVES.
ALTHOUGH WINDS WILL BE DYING OFF... THEY WILL STILL BE SUFFICIENT TO
PRODUCE VERY COLD WIND CHILLS... WHICH WILL PERSIST INTO THE DAY ON
THURSDAY. THE NORTHERN COUNTIES LOOK LIKE THEY WILL SEE WIDESPREAD
WIND CHILLS OF -35 TO -45... WHILE THE CENTRAL AND SOUTHERN PORTION
OF THE AREA WILL MAINLY BE IN THE -25 TO -35 RANGE. SO... ALTHOUGH
THE HEADLINES FOR BLOWING/DRIFTING SNOW WILL END OVERNIGHT... THEY
WILL BE REPLACED BY WIND CHILL HEADLINES THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 220 PM CST WED FEB 26 2014
LONGER TERM TRENDS CONTINUE TO REMAIN COLD. TEMPERATURES ARE
EXPECTED TO REMAIN FAR BELOW NORMAL THROUGH THE ENTIRE PERIOD.
STANDARDIZED ANOMALIES FROM THE NAM AND GEFS CONTINUE TO SHOW H85
TEMPERATURES AROUND 2 TO 3 STANDARD DEVIATIONS BELOW
NORMAL...WHICH SHOULD CONTINUE TO YIELD 30 TO 40 DEGREES BELOW
NORMAL THROUGH MOST OF THE PERIOD. SOME INDICATIONS AT THE END OF
THE PERIOD...INTO NEXT WEEK...THE UPPER FLOW PATTERN MAY FLATTEN A
BIT OVER THE NORTHERN CONUS...ALLOWING SOME MODIFIED PACIFIC TYPE
AIR TO INTRUDE ACROSS THE NORTHERN PLAINS. THAT IS PRETTY FAR IN
THE FUTURE AND THE 12Z ECMWF IS THE MODEL MOST PROMINENT WITH THIS
OVERALL DEVELOPMENT.
A COUPLE OF SNOW CHANCES COME INTO PLAY...NAMELY FRIDAY AND
SATURDAY/SATURDAY NIGHT. MODELS TREND AN INVERTED TROUGH EAST
ACROSS THE CWA ON FRIDAY. BEST FORCING IS FOUND OVER THE SOUTHERN
CWA. WILL CONTINUE TO MENTION LIKELY POPS FOR THE SOUTHERN
THIRD OF THE AREA THEN. WILL HAVE TO MONITOR FOR DEVELOPMENT ON
THE NORTH END OF THE TROUGH AS WELL...BUT CONTINUE CHANCE POPS
THERE. THIS WOULD GENERATE AN INCH OR TWO OF ACCUMULATION TO THE
SOUTH BY FRIDAY EVENING. SHOULD BE A FLUFFY SNOW AND WINDS DO
INCREASE SOME IN THE WAKE OF THE TROUGH. AT THE PRESENT TIME THEY
DO NOT APPEAR TO BE STRONG ENOUGH TO GENERATE SIGNIFICANT
BLOWING/DRIFTING SNOW CONCERNS.
THE NEXT SNOW THREAT ARRIVES FOR SATURDAY AND SATURDAY NIGHT.
MODELS IN SOME DISAGREEMENT AS TO HOW FAR AND SNOW THREAT WOULD
BE AS LARGE COLD ARCTIC HIGH BUILDS SOUTHEAST OVER THE AREA INTO HE
WEEKEND. AT THE MOMENT THE BEST AGREEMENT REMAINS OVER FAR SOUTHERN
MINNESOTA FOR MEASURABLE SNOW AND WILL MENTION LIKELY POPS IN THAT
AREA.
WIND CHILL CONCERNS WILL CONTINUE INTO THE WEEKEND BUT WINDS
SHOULD GRADUALLY DIMINISH AS THE ARCTIC HIGH SETTLES CLOSE TO THE
CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1118 AM CST WED FEB 26 2014
MAIN ISSUE OF CONCERN WILL BE STRONG WINDS AHEAD OF COLD FRONT
THROUGH MID AFTERNOON... THEN BEHIND THE FRONT WITH THE STRONG
COLD ADVECTION THROUGH THIS EVENING. BLOWING SNOW IS EXPECTED
GIVEN THE EXPECTATION FOR WIND GUSTS AOA 35KT... BUT WE/RE STILL
WAITING TO SEE HOW BAD THE BLOWING GETS SINCE MOST OF THE MORE
RECENT SNOWFALL IS STILL DOWNSTREAM OF WHERE CURRENT HIGHER WINDS
ARE OCCURRING. THERE ARE SOME SPOTTY MVFR CEILINGS NEAR THE
FRONTAL BOUNDARY... BUT THOSE AND THE MAIN CHANCE FOR ANY LIGHT
SNOW STILL LOOKS TO MAINLY IMPACT LOCATIONS NORTH/EAST OF THE
FORECAST AREA. HOWEVER... CONTINUED TO MENTION AT LEAST SOME
POSSIBILITY OF NEAR-MVFR CEILINGS FOR A BRIEF WINDOW OF TIME
ACROSS THE NORTHEAST TAF SITES. OTHERWISE... STUCK VERY CLOSE TO
THE PREVIOUS FORECAST... WHICH LOOKED TO HAVE A GOOD HANDLE ON THE
TIMING OF THE STRONGEST WINDS AND A BEST GUESS OF WHAT
VISIBILITIES WILL DO WITH THE BLOWING SNOW. SHOULD SEE THINGS
QUICKLY IMPROVE OVERNIGHT... WITH LIGHT WINDS BY MORNING.
KMSP...MAIN AREA OF UNCERTAINTY WITH THE TAF IS THE DEGREE OF
VISIBILITY REDUCTION WHEN WINDS PICK UP LATER THIS AFTERNOON INTO
THIS EVENING. STAYED SOMEWHAT OPTIMISTIC FOR NOW... BUT AMENDMENTS
COULD CERTAINLY OCCUR IF WE START TO SEE VISIBILITIES
SIGNIFICANTLY DROP IN UPSTREAM LOCATIONS. OTHERWISE... HAVE GOOD
CONFIDENCE OVERALL IN THE TIMING OF WIND SHIFT/SPEEDS AND THE
POTENTIAL WINDOW OF ANY NEAR-MVFR CEILINGS.
/OUTLOOK FOR KMSP/
THURSDAY NIGHT...VFR. SOUTHEAST WIND 5 TO 15 KT.
FRIDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE OF
SNOW. SOUTHEAST WIND 5 TO 10 KT SHIFTING NORTHWEST.
FRIDAY NIGHT...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 5 TO 10 KT.
SATURDAY AND SATURDAY NIGHT...VFR. NORTHWEST WIND 5 TO 15 KT
DECREASING TO LESS THAN 5 KT.
SUNDAY...VFR. NORTHWEST WIND 5 TO 15 KT.
SUNDAY NIGHT...MVFR CEILINGS POSSIBLE. NORTHWEST WIND 10 TO 15
KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ047-
048-054>070-073>078-082>085-091>093.
BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ066>069-074>077-
082>085-091>093.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR MNZ041>045-
049>053.
BLIZZARD WARNING UNTIL 3 AM CST THURSDAY FOR MNZ041-042-048-049-
055>059-065-073.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ043>045-
047-050-051-054-064.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ052-053-
060>063-070-078.
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
WIZ023>028.
WIND CHILL WARNING FROM 3 AM TO NOON CST THURSDAY FOR WIZ014>016.
WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...TRH
LONG TERM...DWE
AVIATION...TRH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
243 PM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF
SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF
PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL
RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY
WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY
ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS
ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS
HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE
ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY
WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS
DISCUSSIONS FOLLOW.
SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN
CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO
DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH
EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS
DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION
FOLLOWS.
SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z
AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE
ONTARIO AND AS FRONTOGENESIS CIRCULATION HAS BEEN DISRUPTED BY
THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT
WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE
CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN
INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF
STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST
CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT
RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A
QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE
MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH
HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN
SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO
LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL
CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH
WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST
FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY NIGHT/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE
AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND
AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE
(850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS
MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN
ADVANCE OF NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS
VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL
BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY
THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST
SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS
OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING
100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING
ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE
SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME.
SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT
AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE
SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER
SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK
1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF
TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS.
MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY
IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA
THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN
ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF
PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO
THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND
KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH
KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY.
RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND
LOCALLY 8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 243 PM EST WEDNESDAY...GOING INTO THE UPCOMING WEEKEND...HIGH
PRESSURE OFF THE NEW ENGLAND COAST WITH SOUTHERLY FETCH STARTS
OFF THE SATURDAY TIMEFRAME. LATEST GFS/ECMWF BOTH BRING LOW
PRESSURE EASTWARD THRU NORTHERN PORTIONS OF THE GREAT LKS AND
SLOWLY INTO SOUTHERN QUEBEC BY SATURDAY NIGHT. WITH APPROACH OF
THIS SYSTEM...SFC RIDGE DOES SLIDE SOUTH OF THE AREA AND IN EFFECT
SLOWS APPROACH OF TRAILING FRONTAL BOUNDARY UNTIL LATE SAT NGT.
BULK OF PRECIP W/ FROPA TO OCCUR ON SUNDAY...WITH NOSING SFC RIDGE
BEHIND FRONT COMBINED WITH ZONAL MID-LEVEL FLOW PUSHING FRONT
OFFSHORE FOR SUNDAY NIGHT. RESPITE FROM PRECIP IS BRIEF THOUGH AS
SECONDARY LOW ALONG FRONT LIFTS TOWARDS THE AREA. GFS/ECMWF
SOLUTIONS DO DIFFER FROM HERE TO END OF FORECAST PERIOD... IN THAT
GFS WANTS CUTOFF UPPER LOW OVER GREAT LKS TO KEEP CHANCE FOR
PRECIP TO LINGER THRU MIDWEEK NEXT WEEK...WHILE THE ECMWF HAS
ZONAL FLOW PUSH SECOND SYSTEM OFF TO OUR SOUTH WITH SFC HIGH
PRESSURE BUILDING OVER AREA. WITH INCONSISTENCIES SHOWING WILL
KEEP PRECIP OVER AREA FOR SECOND LOW WITH HIGHEST POPS SOUTH BASED
ON TRACK...THEN SL CHANCE/CHANCE POPS FOR --SW IN REST OF TIME.
WITH THE EXCEPTION OF WAA ON SOUTHERLY FLOW INITIALLY FOR
SATURDAY...THE MAJORITY OF THE EXTEND PERIOD WILL HAVE BLW NORMAL
TEMPS FOR BOTH HIGHS AND LOWS AS A COMBO OF SFC HIGHS AND UPPER
LEVEL SUPPORT WILL KEEP REINFORCING CD AIR OVER THE REGION.
OVERALL TEMPS LOOKING FOR A RANGE OF TEENS/L20S FOR HIGHS AND ZERO
TO 10 BLW FOR OVERNGT PERIODS. AGAIN SAT/SAT NGT ARE THE OUTLIERS
FOR TEMPS DUE TO WAA SATURDAY AND THE SLOW TRANSITION BACK TO
COLDER AIRMASS DUE TO SLOW MVG FRONT SAT NGT.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...MAINLY VFR COND THRU FORECAST PERIOD W/
SCT025-040 BKN080 FOR BTV/MPV/PBG/RUT. MVFR -SW FOR RUT POSSIBLE
THRU 00Z THURS W/ 3SM VSBY. AFT 15Z THURSDAY...MVFR COND DEVELOP
WITH -SW AND CEILINGS NEAR BKN025. FOR MSS/SLK...MIX OF VFR DOWN
TO IFR COND AT TIMES W/ BLSN THRU 00Z THURSDAY DROPPING VSBY TO
3-6SM AT TIMES...THEN -SW DEVELOPING FROM LK BAND AS WINDS SHIFTS
W/ VSBY 2-5SM AND CEILINGS BKN020-040. WINDS OVERALL WSW 10-20KTS
WITH GUSTS NEAT 30KTS THRU 00Z THURS THEN 10KTS OR LESS THRU 15Z
THURSDAY THEN BECM SOUTHERLY AT 10-15KTS..
OUTLOOK 18Z THURSDAY THROUGH MONDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY
WITH ADDITIONAL LIGHT SNOW SHOWERS. VFR MONDAY W/ OCNL MVFR -SW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...JN
AVIATION...JN/TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1238 PM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF
SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF
PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL
RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY
WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY
ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS
ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS
HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE
ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY
WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS
DISCUSSIONS FOLLOW.
SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN
CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO
DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH
EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS
DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION
FOLLOWS.
SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z
AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE
ONTARIO AND AS FRONTOGENESIS CIRCULATION HAS BEEN DISRUPTED BY
THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT
WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE
CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN
INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF
STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST
CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT
RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A
QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE
MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH
HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN
SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO
LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL
CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH
WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST
FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE
AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND
AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE
(850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS
MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN
ADVANCE OF NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS
VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL
BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY
THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST
SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS
OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING
100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING
ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE
SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME.
SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT
AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE
SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER
SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK
1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF
TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS.
MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY
IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA
THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN
ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF
PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO
THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND
KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH
KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY.
RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND
LOCALLY 8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE
OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU
NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO
OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING
TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON
MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT
BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL
CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH
LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...MAINLY VFR COND THRU FORECAST PERIOD W/
SCT025-040 BKN080 FOR BTV/MPV/PBG/RUT. MVFR -SW FOR RUT POSSIBLE
THRU 00Z THURS W/ 3SM VSBY. AFT 15Z THURSDAY...MVFR COND DEVELOP
WITH -SW AND CEILINGS NEAR BKN025. FOR MSS/SLK...MIX OF VFR DOWN
TO IFR COND AT TIMES W/ BLSN THRU 00Z THURSDAY DROPPING VSBY TO
3-6SM AT TIMES...THEN -SW DEVELOPING FROM LK BAND AS WINDS SHIFTS
W/ VSBY 2-5SM AND CEILINGS BKN020-040. WINDS OVERALL WSW 10-20KTS
WITH GUSTS NEAT 30KTS THRU 00Z THURS THEN 10KTS OR LESS THRU 15Z
THURSDAY THEN BECM SOUTHERLY AT 10-15KTS..
OUTLOOK 18Z THURSDAY THROUGH MONDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY
WITH ADDITIONAL LIGHT SNOW SHOWERS. VFR MONDAY W/ OCNL MVFR -SW.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...JN/TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1224 PM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF
SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF
PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL
RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY
WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 1222 PM EST WEDNESDAY...SNOW SQUALL ACTIVITY HAS MOSTLY
ENDED ACROSS EASTERN VERMONT AND HAVE ADJUSTED POPS/WX GRIDS
ACCORDINGLY. CLOUDS ARE VARIABLE ACROSS THE AREA WITH SOME BREAKS
HERE AND THERE...ESPECIALLY IN THE CHAMPLAIN VALLEY. HAVE
ADJUSTED SKY GRIDS TO ACCOUNT FOR THIS AS WELL. BRISK WESTERLY
WINDS CONTINUE WITH COLDER THAN NORMAL MAX TEMPS. PREVIOUS
DISCUSSIONS FOLLOW.
SNOW SQUALL ACTIVITY CURRENTLY MOVING ACROSS THE NORTHERN
CHAMPLAIN VALLEY. THINK THAT CURRENT FORECAST IS IN GOOD SHAPE SO
DID NOT ALTER POPS OR WX AT ALL. THIS AREA OF SQUALLS WILL PUSH
EASTWARD ACROSS VERMONT OVER THE NEXT FEW HOURS AND THEN POPS
DECREASE LATE THIS AFTERNOON AND EVENING. PREVIOUS DISCUSSION
FOLLOWS.
SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z
AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE
ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS BEEN DISRUPTED BY
THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT
WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE
CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN
INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF
STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST
CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT
RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A
QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE
MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH
HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN
SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO
LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL
CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH
WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST
FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE
AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND
AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE
(850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS
MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN
ADVANCE OF NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS
VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL
BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY
THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST
SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS
OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING
100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING
ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE
SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME.
SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT
AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE
SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER
SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK
1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF
TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS.
MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY
IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA
THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN
ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF
PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO
THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND
KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH
KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY.
RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND
LOCALLY 8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE
OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU
NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO
OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING
TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON
MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT
BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL
CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH
LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC
BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL
SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE
SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER
ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND
ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH
SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20
TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN
SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT
PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL
OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF
UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO
PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT
SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15
KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY
BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET
THIS EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY
WITH ADDITIONAL LIGHT SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
952 AM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF
SNOW IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF
PERIODS OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL
RANGE FROM THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY
WINDS OF 15 TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 928 AM EST WEDNESDAY...SNOW SQUALL ACTIVITY CURRENTLY
MOVING ACROSS THE NORTHERN CHAMPLAIN VALLEY. THINK THAT CURRENT
FORECAST IS IN GOOD SHAPE SO DID NOT ALTER POPS OR WX AT ALL.
THIS AREA OF SQUALLS WILL PUSH EASTWARD ACROSS VERMONT OVER THE
NEXT FEW HOURS AND THEN POPS DECREASE LATE THIS AFTERNOON AND
EVENING. PREVIOUS DISCUSSION FOLLOWS.
SNOW SHOWER ACTIVITY HAS LOST ORGANIZATION AND STRUCTURE 10-12Z
AS IT MOVED AWAY FROM THE LAKE INDUCED INSTABILITY NEAR LAKE
ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS BEEN DISRUPTED BY
THE STEEP TERRAIN OF THE ADIRONDACKS. EXPECTATION - CONSISTENT
WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS WILL SHIFT THRU THE
CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN SHOW AN INCREASE IN
INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z WITH DEVELOPMENT OF
STEEP LOW- LEVEL LAPSE RATES AND SBCAPE UP TO 100 J/KG. BEST
CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE ACROSS THE CT
RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH. WE/LL SEE A
QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT DURING THE
MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH
HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN
SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO
LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL
CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH
WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST
FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE
AREA THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND
AND A PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE
(850MB TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS
MAY LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN
ADVANCE OF NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS
VIGOROUS IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL
BE MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY
THURSDAY. IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST
SECTIONS OF THE NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS
OPPOSED TO THE WEAKER ONE TODAY)...WITH 06Z NAM INDICATING
100-150 J/KG ACROSS MUCH OF THE NORTH COUNTRY. ALSO INTERESTING
ARE PROGGED PBL HEIGHTS TO 600MB WITH STEEP LAPSE RATES FROM THE
SFC-12 KFT...A DEFAULT TROPOPAUSE IN THE ARCTIC AIR REGIME.
SO...GOOD CONVECTIVE SNOW POTENTIAL. FRONTOGENETIC FORCING IS NOT
AS WELL ORGANIZED AS WEDNESDAY...SO WOULD ANTICIPATE SMALLER LINE
SEGMENTS AND CONVECTIVE CELLS PRODUCING BRIEF BURSTS OF HEAVIER
SNOW SHOWERS AND POSSIBLE SQUALLS WITH GUSTS 30-35 MPH. A QUICK
1-3" IS POSSIBLE IN SPOTS...AND WILL AGAIN CAUSE SOME BRIEF
TRANSPORTATION HAZARD DUE TO LOW VSBY AND SNOW COVERED ROADS.
MADE MENTION OF THIS AS WELL IN THE MORNING HWO. HIGHS THURSDAY
IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST OF THE AREA
THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES. LOWS AGAIN
ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN ADIRONDACKS IF
PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO
THE REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND
KEPT THE FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH
KEEPS 850MB TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY.
RATHER INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND
LOCALLY 8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE
OF FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU
NEXT TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO
OUR NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING
TO 2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON
MONDAY INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT
BACK NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL
CONT TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH
LLVL CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC
BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL
SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE
SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER
ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND
ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH
SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20
TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN
SNOW SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE WEST AT
PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL
OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF
UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO
PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT
SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15
KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY
BTWN 14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET
THIS EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH
ADDITIONAL LIGHT SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS/NEILES
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
737 AM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW
IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS
OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM
THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15
TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 732 AM EST WEDNESDAY...SNOW SHOWER ACTIVITY HAS LOST
ORGANIZATION AND STRUCTURE 10-12Z AS IT MOVED AWAY FROM THE LAKE INDUCED
INSTABILITY NEAR LAKE ONTARIO AND AS FRONTOGENETIC CIRCULATION HAS
BEEN DISRUPTED BY THE STEEP TERRAIN OF THE ADIRONDACKS.
EXPECTATION - CONSISTENT WITH 11Z RAP - IS THAT LIGHT SNOW SHOWERS
WILL SHIFT THRU THE CHAMPLAIN VALLEY NEXT 1-3 HOURS...AND THEN
SHOW AN INCREASE IN INTENSITY ACROSS CENTRAL AND ERN VT AFTER 15Z
WITH DEVELOPMENT OF STEEP LOW-LEVEL LAPSE RATES AND SBCAPE UP TO
100 J/KG. BEST CHANCE FOR BRIEF MODERATE TO HEAVY SNOW WILL BE
ACROSS THE CT RIVER VALLEY BEFORE ACTIVITY SHIFTS EAST INTO NH.
WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS...HIGHEST CENTRAL/ERN VT
DURING THE MIDDAY HRS. OTHERWISE...LOOKING AT CONTINUED COLD TEMPS
WITH HIGHS IN THE MID TO UPPER TEENS...EXCEPT LOW 20S IN FAR SERN
SECTIONS. INCREASED COLD ADVECTION THIS AFTN MAY ALLOW TEMPS TO
LEVEL OFF AFTER NOON EDT. STEEP LOW-LEVEL LAPSE RATES WILL
CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE OF THE FRONT 15-25 MPH
WITH POST- FRONTAL GUSTS TO 30 MPH...SHIFTING INTO THE WEST
FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA
THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A
PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB
TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY
LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF
NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS
IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE
MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY.
IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE
NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER
ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE
NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB
WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN
THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL.
FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO
WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING
BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH
GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL
AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND
SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING
HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST
OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES.
LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN
ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE
REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE
FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB
TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER
INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY
8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF
FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT
TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR
NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO
2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY
INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK
NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT
TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL
CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC
BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL
SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE
SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER
ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND
ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH
SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20
TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW
SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE
WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL
OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF
UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO
PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT
SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15
KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN
14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS
EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH
ADDITIONAL LIGHT SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
632 AM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW
IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS
OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM
THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15
TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 342 AM EST WEDNESDAY...VARIABLE CLOUD COVER...WIND AND
WEATHER CONDITIONS TODAY WITH REINFORCING ARCTIC FRONTAL PASSAGE
FROM WEST-TO-EAST EXPECTED LATER THIS MORNING. EXCELLENT
CONVERGENCE NOTED ALONG APPROACHING SECONDARY/ARCTIC FRONT ACROSS
ERN LAKE ONTARIO AND WRN NY EARLY THIS AM. EARLY AM RUC MODEL
ANALYSIS INDICATES THE FRONT IS ASSOCIATED WITH STRONG SFC-925MB
FRONTOGENESIS WITH ACCOMPANYING ISALLOBARIC RISE/FALL
COUPLET...RESULTING IN ROBUST LINEAR FORCING. LAKE INDUCED
INSTABILITY UP TO 100 J/KG AND STRONG LOW-LEVEL FORCING FOR ASCENT
IS RESULTING IN NARROW CONVECTIVE BAND ALONG THE FRONT PRODUCING
SNOW SQUALL ACTIVITY WITH BRIEF PERIOD OF MODERATE TO HEAVY SNOW
(20-30 MINUTES). BTV SNOW SQUALL PARAMETER MAINTAINS SNOW SQUALL
POTENTIAL AS FRONT SHIFTS EWD CROSSING OUR REGION THIS
MORNING...BEFORE EXITING EAST OF THE CT RIVER VLY BY 18Z.
FAVORABLE FRONTOGENETIC FORCING AND LOW-LEVEL MOISTURE AND
INSTABILITY WILL BRING A BAND OF SNOW SHOWERS AND SQUALLS ACROSS
NRN NY THRU ABOUT 12-13Z. MAY SEE CONVECTIVE ACTIVITY WEAKEN
SLIGHTLY THRU THE CHAMPLAIN VALLEY WITH ABSENCE OF INSTABILITY
LOCALLY AND FLOW DISRUPTION ACROSS THE ADIRONDACK REGION.
INSTABILITY IS ACTUALLY BEST ACROSS NH/ME WITH INSOLATIONAL
HEATING IN ADVANCE OF THE BNDRY...SO AGAIN...ANTICIPATE
ORGANIZATION MAY WANE A BIT THRU THE CHAMPLAIN VLY...BUT INCREASE
AGAIN ACROSS ERN VT MIDDAY HRS BEFORE EXITING RAPIDLY EWD WITH
FROPA BY 17-18Z. SBCAPE VALUES REACH 100-150 J/KG IN NAM MODEL
SOUNDINGS ALONG THE CT RIVER BETWEEN 15-18Z TODAY JUST AHEAD OF
THE FRONTAL BNDRY. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS WITH
THESE SNOW SHOWERS AND SQUALLS...LIKELY HIGHEST IN NRN NY AND THEN
CENTRAL AND ERN VT. MAY RESULT IN SLOW TRAVEL FOR AN HOUR OR SO
DURING SQUALL PASSAGE. WE/LL CONTINUE TO HIGHLIGHT THIS POTL IN
THE HAZARDOUS WEATHER OUTLOOK AND THROUGH SOCIAL MEDIA.
OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID
TO UPPER 20S...EXCEPT LOW 20S IN FAR SERN SECTIONS. STEEP LOW-
LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE
OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30
MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA
THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A
PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB
TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY
LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF
NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS
IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE
MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY.
IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE
NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER
ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE
NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB
WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN
THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL.
FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO
WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING
BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH
GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL
AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND
SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING
HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST
OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES.
LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN
ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE
REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE
FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB
TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER
INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY
8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF
FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT
TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR
NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO
2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY
INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK
NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT
TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL
CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC
BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL
SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT ACRS THE
SLV/WESTERN DACKS...WITH A NARROW BAND OF ENHANCED SNOW SHOWER
ACTIVITY WITH VIS <1SM. LATEST HRRR/RAP DATA SHOWS THIS BAND
ENTERING THE CPV BTWN 12-15Z THIS MORNING...BUT WEAKENING WITH
SOUTHWEST DOWNSLOPE FLW AND INTERACTION OFF THE DACKS. A BRIEF 20
TO 30 MINUTE WINDOW OF MVFR CONDITIONS WITH VIS AROUND 3SM IN SNOW
SHOWERS WL OCCUR...ALONG WITH A WIND SHIFT TO THE
WEST AT PBG/BTV. THINKING IFR CONDITIONS ASSOCIATED WITH BOUNDARY WL
OCCUR AFT 14Z AT MPV/RUTLAND. IN ADDITION...THE COMBINATION OF
UPSLOPE FLW AND SOME WEAK LAKE ENHANCED MOISTURE WL CONT TO
PRODUCE ON AND OFF IFR VIS IN LIGHT SNOW THRU 14Z THIS MORNING AT
SLK. SOUNDINGS SUPPORT GUSTY WEST/NORTHWEST WINDS OF 10 TO 15
KNOTS WITH GUSTS 25 TO 30 KNOTS DEVELOPING BEHIND FROPA TODAY BTWN
14Z-22Z TODAY. THESE WINDS WL SLOWLY DISSIPATE BY SUNSET THIS
EVENING.
OUTLOOK 12Z THURSDAY THROUGH SUNDAY... MAINLY VFR CONDITIONS BTWN
06Z AND 12Z THURSDAY...BEFORE NEXT CLIPPER SYSTEM WITH SNOW
SHOWERS AND IFR/MVFR CONDITIONS DEVELOP BTWN 15Z AND 21Z THURS. A
BRIEF SNOW SQUALL WL ONCE AGAIN BE POSSIBLE ON THURS ASSOCIATED
WITH NEXT SURGE OF ARCTIC AIR. LINGERING UPSLOPE MTN SNOW SHOWERS
WL PREVAIL AT SLK/MPV INTO EARLY FRIDAY MORNING WITH PERIODS OF
IFR/MVFR POSSIBLE...ALONG WITH GUSTY WEST/NORTHWEST WINDS. SFC
HIGH PRES WITH VFR CONDITIONS DEVELOP FRIDAY INTO
SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT AFTN INTO SUNDAY WITH
ADDITIONAL LIGHT SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
349 AM EST WED FEB 26 2014
.SYNOPSIS...
A PROLONGED STRETCH OF COLD WEATHER...WITH TEMPERATURES RUNNING
10 TO 20 DEGREES BELOW AVERAGE...IS EXPECTED TO PERSIST THROUGH
EARLY NEXT WEEK. REINFORCING ARCTIC FRONTS MOVING FROM WEST TO
EAST ACROSS THE NORTH COUNTRY THIS MORNING AND AGAIN DURING THE
MIDDAY THROUGH AFTERNOON HOURS THURSDAY WILL BRING SCATTERED SNOW
SHOWERS AND SNOW SQUALLS. A QUICK DUSTING TO A COUPLE INCHES OF SNOW
IS POSSIBLE WITH THESE FRONTAL PASSAGES...ALONG WITH BRIEF PERIODS
OF VERY LOW VISIBILITY. HIGH TEMPERATURES TODAY WILL RANGE FROM
THE MID TEENS TO LOWER 20S...AND DEVELOPING WESTERLY WINDS OF 15
TO 25 MPH WILL RESULT IN WIND CHILL VALUES NEAR ZERO.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 342 AM EST WEDNESDAY...VARIABLE CLOUD COVER...WIND AND
WEATHER CONDITIONS TODAY WITH REINFORCING ARCTIC FRONTAL PASSAGE
FROM WEST-TO-EAST EXPECTED LATER THIS MORNING. EXCELLENT
CONVERGENCE NOTED ALONG APPROACHING SECONDARY/ARCTIC FRONT ACROSS
ERN LAKE ONTARIO AND WRN NY EARLY THIS AM. EARLY AM RUC MODEL
ANALYSIS INDICATES THE FRONT IS ASSOCIATED WITH STRONG SFC-925MB
FRONTOGENESIS WITH ACCOMPANYING ISALLOBARIC RISE/FALL
COUPLET...RESULTING IN ROBUST LINEAR FORCING. LAKE INDUCED
INSTABILITY UP TO 100 J/KG AND STRONG LOW-LEVEL FORCING FOR ASCENT
IS RESULTING IN NARROW CONVECTIVE BAND ALONG THE FRONT PRODUCING
SNOW SQUALL ACTIVITY WITH BRIEF PERIOD OF MODERATE TO HEAVY SNOW
(20-30 MINUTES). BTV SNOW SQUALL PARAMETER MAINTAINS SNOW SQUALL
POTENTIAL AS FRONT SHIFTS EWD CROSSING OUR REGION THIS
MORNING...BEFORE EXITING EAST OF THE CT RIVER VLY BY 18Z.
FAVORABLE FRONTOGENETIC FORCING AND LOW-LEVEL MOISTURE AND
INSTABILITY WILL BRING A BAND OF SNOW SHOWERS AND SQUALLS ACROSS
NRN NY THRU ABOUT 12-13Z. MAY SEE CONVECTIVE ACTIVITY WEAKEN
SLIGHTLY THRU THE CHAMPLAIN VALLEY WITH ABSENCE OF INSTABILITY
LOCALLY AND FLOW DISRUPTION ACROSS THE ADIRONDACK REGION.
INSTABILITY IS ACTUALLY BEST ACROSS NH/ME WITH INSOLATIONAL
HEATING IN ADVANCE OF THE BNDRY...SO AGAIN...ANTICIPATE
ORGANIZATION MAY WANE A BIT THRU THE CHAMPLAIN VLY...BUT INCREASE
AGAIN ACROSS ERN VT MIDDAY HRS BEFORE EXITING RAPIDLY EWD WITH
FROPA BY 17-18Z. SBCAPE VALUES REACH 100-150 J/KG IN NAM MODEL
SOUNDINGS ALONG THE CT RIVER BETWEEN 15-18Z TODAY JUST AHEAD OF
THE FRONTAL BNDRY. WE/LL SEE A QUICK DUSTING TO 2" IN SPOTS WITH
THESE SNOW SHOWERS AND SQUALLS...LIKELY HIGHEST IN NRN NY AND THEN
CENTRAL AND ERN VT. MAY RESULT IN SLOW TRAVEL FOR AN HOUR OR SO
DURING SQUALL PASSAGE. WE/LL CONTINUE TO HIGHLIGHT THIS POTL IN
THE HAZARDOUS WEATHER OUTLOOK AND THROUGH SOCIAL MEDIA.
OTHERWISE...LOOKING AT CONTINUED COLD TEMPS WITH HIGHS IN THE MID
TO UPPER 20S...EXCEPT LOW 20S IN FAR SERN SECTIONS. STEEP LOW-
LEVEL LAPSE RATES WILL CONTRIBUTE TO GUSTY S-SW WINDS IN ADVANCE
OF THE FRONT 15-25 MPH WITH POST- FRONTAL GUSTS TO 30
MPH...SHIFTING INTO THE WEST FOLLOWING FRONTAL PASSAGE.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH FRIDAY/...
AS OF 342 AM EST WEDNESDAY...SFC RIDGE BUILDS BRIEFLY ACROSS THE AREA
THIS EVENING AND OVERNIGHT...ALLOWING FOR DIMINISHING WIND AND A
PERIOD OF PARTIAL CLEARING. WITH ARCTIC AIR MASS IN PLACE (850MB
TEMPS -24C)...THE RADIATIONAL COOLING WILL RESULT IN COLD
OVERNIGHT LOWS RANGING FROM NEAR ZERO IN THE CHAMPLAIN VALLEY TO
AROUND 10 BELOW IN THE ADIRONDACKS AND NORTHEAST KINGDOM. TEMPS MAY
LEVEL OFF AFTER MIDNIGHT WITH SOME INCREASE IN CLOUDS IN ADVANCE OF
NEXT SYSTEM.
NEXT SHORTWAVE TROUGH ROTATING AROUND THE SRN PERIPHERY OF PARENT
UPPER LOW ANCHORED ACROSS JAMES BAY WILL TRANSLATE ACROSS THE ERN
GREAT LAKES AROUND 12Z THURSDAY...AND ACROSS THE NORTH COUNTRY
15-21Z TIME FRAME THURSDAY. THIS NEXT SHORTWAVE IS APPEARS VIGOROUS
IN WV IMAGERY AND IN NWP PROJECTIONS...SO QG ASCENT WILL BE
MODERATELY STRONG AS UPR TROUGH APPROACHES DURING THE DAY THURSDAY.
IT APPEARS SBCAPE VALUES WILL BE BETTER ACROSS MOST SECTIONS OF THE
NORTH COUNTRY WITH THIS SYSTEM TOMORROW (AS OPPOSED TO THE WEAKER
ONE TODAY)...WITH 06Z NAM INDICATING 100-150 J/KG ACROSS MUCH OF THE
NORTH COUNTRY. ALSO INTERESTING ARE PROGGED PBL HEIGHTS TO 600MB
WITH STEEP LAPSE RATES FROM THE SFC-12 KFT...A DEFAULT TROPOPAUSE IN
THE ARCTIC AIR REGIME. SO...GOOD CONVECTIVE SNOW POTENTIAL.
FRONTOGENETIC FORCING IS NOT AS WELL ORGANIZED AS WEDNESDAY...SO
WOULD ANTICIPATE SMALLER LINE SEGMENTS AND CONVECTIVE CELLS PRODUCING
BRIEF BURSTS OF HEAVIER SNOW SHOWERS AND POSSIBLE SQUALLS WITH
GUSTS 30-35 MPH. A QUICK 1-3" IS POSSIBLE IN SPOTS...AND WILL
AGAIN CAUSE SOME BRIEF TRANSPORTATION HAZARD DUE TO LOW VSBY AND
SNOW COVERED ROADS. MADE MENTION OF THIS AS WELL IN THE MORNING
HWO. HIGHS THURSDAY IN THE UPR TEENS TO LOW 20S. SYSTEM MOVES EAST
OF THE AREA THURSDAY NIGHT WITH JUST A FEW LINGERING MTN FLURRIES.
LOWS AGAIN ZERO TO -10F...BUT LOCALLY COLDER IN THE NRN
ADIRONDACKS IF PARTIAL CLEARING CAN OCCUR LATE.
FRIDAY LOOKS QUIET WITH LOW TO MID LEVEL RIDGING BUILDING INTO THE
REGION FROM THE WEST. SHOULD BE PARTLY TO MOSTLY SUNNY AND KEPT THE
FORECAST DRY. REINFORCED CAA BEHIND THURSDAY/S TROUGH KEEPS 850MB
TEMPS OF -23 TO -24C ACROSS THE REGION FOR FRIDAY. RATHER
INEFFECTIVE SUNSHINE WITH HIGHS IN THE LOW-MID TEENS...AND LOCALLY
8-9F IN THE NRN ADIRONDACK REGION.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 330 AM EST WEDNESDAY...LITTLE CHANGE FROM PREVIOUS COUPLE OF
FCSTS WITH MID/UPPER LVL TROF PREVAILING ACRS THE NE CONUS AND
SEVERAL OPPORTUNITIES FOR ACCUMULATING SNOWFALL FROM SAT THRU NEXT
TUES. WEAK WARM FRNT FEATURE AND SFC LOW PRES TRACKING TO OUR
NORTH WL PRODUCE LIGHT SNOW SHOWERS ACRS OUR CWA ON SATURDAY.
TEMPS SHOULD WARM INTO THE TEENS AND 20S ON SATURDAY. A DUSTING TO
2 INCHES LOOKS LIKELY...WITH HIGHEST VALUES ACRS THE MTNS.
MEANWHILE...LATEST 00Z GUIDANCE IS TRENDING FURTHER SOUTH WITH
SYSTEM ON MONDAY/TUESDAY...AND STRONGER WITH SFC HIGH PRES ACRS
SOUTHERN CANADA. THIS WL PROVIDE CWA WITH COLD AND DRY NORTHERLY
WINDS SUNDAY INTO MONDAY ALONG WITH SUPPRESSING BETTER
MOISTURE/LIFT ACRS THE MID ATLANTIC STATES/SNE. HOWEVER...STILL
NOTICING A SHARP NORTH TO SOUTH LLVL THERMAL GRADIENT ACRS OUR
CWA...ALONG WITH SOME ENHANCED 850 TO 500MB RH MOVING FROM SW TO
NE ACRS OUR REGION. THIS MOISTURE COMBINED WITH SEVERAL EMBEDDED
5H VORT IN THE FAST CONFLUENT WESTERLY FLW ALOFT SHOULD BE ENOUGH
TO PRODUCE A LIGHT ACCUMULATING SNOWFALL ACRS THE REGION ON MONDAY
INTO TUESDAY. FURTHERMORE...STILL THINKING MODELS WL SHIFT BACK
NORTH WITH PROGGED SFC LOW PRES TRACK...ESPECIALLY AS
SYSTEM/ENERGY ALOFT ENTERS THE WESTERN CONUS THIS WEEKEND. WL CONT
TO MENTION HIGH CHC POPS FOR THIS TIME PERIOD AND WAIT UNTIL
BETTER AGREEMENT OCCURS IN GUIDANCE BEFORE INCREASING TO LIKELY
POPS. TEMPS WL CONT TO BE TRICKY...ESPECIALLY ASSOCIATED WITH LLVL
CAA ON SUNDAY INTO MONDAY. LATEST GFS IS SHOWING 925MB TEMPS
DROPPING BTWN -22C AND -26C WITH NORTHERLY WINDS. THIS COMBINED
WITH INCREASING HIGH CLOUDS FROM APPROACHING SOUTHERN STREAM
SYSTEM SUPPORTS HIGHS ONLY IN THE SINGLE DIGITS MTNS TO L/M TEEN
VALLEYS. HAVE UNCUT SUPERBLEND BY SEVERAL DEGREES FOR HIGHS...BUT
KEPT CLOSE WITH LOWS RANGING FROM -10F TO +10F...AND HIGHLY
VARIABLE BASED ON CLOUDS/WINDS. SLIGHTLY WARMER TEMPS ARE
ANTICIPATED FOR MONDAY NIGHT INTO TUESDAY...BEFORE ADDITIONAL
COOLING ARRIVES BY THE MID OF NEXT WEEK. OVERALL....TEMPS WL
REMAIN 10 TO 20 DEGREES BLW NORMAL THRU THE PERIOD.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THROUGH 06Z THURSDAY...AVIATION CHALLENGE WL BE TIMING OF ARCTIC
BOUNDARY THIS MORNING AND ASSOCIATED SNOW SHOWERS AND POTENTIAL
SNOW SQUALL. CRNT SFC ANALYSIS SHOWS COLD FRNT APPROACHING THE
OTTAWA VALLEY AND EXTENDING SOUTH ACRS CENTRAL LAKE ONTARIO...WITH
A NARROW BAND OF ENHANCED SNOW SHOWER ACTIVITY WITH VIS <1/2SM.
USING THE DISTANCE TIME TOOL IN AWIPS AND LATEST HRRR/RAP DATA
SHOWS THIS BAND IMPACTING MSS BTWN 09Z-10Z...SLK BTWN 10-12Z...AND
INTO THE CPV BY 12Z. A BRIEF 20 TO 30 MINUTE WINDOW OF IFR/LIFR
CONDITIONS WITH VIS BLW 1SM IN SNOW SHOWERS WL OCCUR...ALONG WITH
A WIND SHIFT TO THE WEST...ESPECIALLY AT MSS. THINKING IFR
CONDITIONS ASSOCIATED WITH BOUNDARY WL OCCUR AFT 12Z AT BTV/MPV
AND RUTLAND. IN ADDITION...THE COMBINATION OF UPSLOPE FLW AND SOME
WEAK LAKE ENHANCED MOISTURE WL CONT TO PRODUCE ON AND OFF IFR VIS
IN LIGHT SNOW THRU 12Z THIS MORNING AT SLK. ALSO...CANNOT RULE OUT
POTENTIAL FOR -SHSN AT MPV WITH BRIEF PERIODS OF IFR/MVFR
CONDITIONS BEFORE FROPA THIS MORNING. SOUNDINGS SUPPORT GUSTY
WEST/NORTHWEST WINDS OF 10 TO 15 KNOTS WITH GUSTS 25 TO 30 KNOTS
DEVELOPING BEHIND FROPA TODAY BTWN 12Z-22Z TODAY. THESE WINDS WL
SLOWLY DISSIPATE BY SUNSET THIS EVENING.
OUTLOOK 06Z THURSDAY THROUGH SUNDAY...
MAINLY VFR CONDITIONS BTWN 06Z AND 12Z THURSDAY...BEFORE NEXT
CLIPPER SYSTEM WITH SNOW SHOWERS AND IFR/MVFR CONDITIONS DEVELOP
BTWN 15Z AND 21Z THURS. A BRIEF SNOW SQUALL WL ONCE AGAIN BE
POSSIBLE ON THURS ASSOCIATED WITH NEXT SURGE OF ARCTIC AIR.
LINGERING UPSLOPE MTN SNOW SHOWERS WL PREVAIL AT SLK/MPV INTO
EARLY FRIDAY MORNING WITH PERIODS OF IFR/MVFR POSSIBLE...ALONG
WITH GUSTY WEST/NORTHWEST WINDS. SFC HIGH PRES WITH VFR CONDITIONS
DEVELOP FRIDAY INTO SATURDAY...BEFORE NEXT SYSTEM ARRIVES ON SAT
AFTN INTO SUNDAY WITH ADDITIONAL LIGHT SNOW SHOWERS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...TABER
AVIATION...TABER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1243 PM EST WED FEB 26 2014
.SYNOPSIS...
LOW PRESSURE WILL STRENGTHEN JUST OFFSHORE THIS MORNING...BRINGING
COLD RAIN TO THE AREA. DRY HIGH PRESSURE WILL BUILD IN FROM THE
WEST TONIGHT...REINFORCED BY A SECOND HIGH BUILDING SOUTHWARD
THURSDAY AND FRIDAY. THIS WILL MAINTAIN BELOW NORMAL TEMPERATURES.
LOW PRESSURE OFFSHORE MAY BRING CLOUDS AND RAIN FRIDAY NIGHT
THROUGH SATURDAY. WARMER TEMPERATURES ARE EXPECTED EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM WEDNESDAY...LIGHT RAIN AND DRIZZLE CONTINUES TO
MOVE ACROSS THE BULK OF OUR FORECAST AREA ALTHOUGH IT LOOKS LIKE
SOME RELIEF IS IN SIGHT FOR OUR FAR INLAND COUNTIES AS THE BACK
EDGE OF THE PRECIP SHIELD IS NOW IN EVIDENCE. DO NOT EXPECT ANY
MAJOR CHANGES IN THE FORECAST WITH THE AFTERNOON PACKAGE. PREVIOUS
DISCUSSION FOLLOWS:
RAIN IS EXPANDING ACROSS SOUTH CAROLINA THIS MORNING AHEAD OF A
PAIR OF SHORTWAVES. ONE DISTURBANCE IN THE SOUTHERN STREAM NEAR
MOBILE AL WILL CROSS NORTH FLORIDA TODAY... WHILE A POSITIVELY-
TILED SHORTWAVE IN THE NORTHERN STREAM FLOW ACROSS MISSOURI WILL
MOVE ACROSS NC/VA THIS EVENING. AT THE SURFACE A COLD FRONT SLID
SOUTH ACROSS THE AREA YESTERDAY EVENING...AND A SECOND SURGE OF
NORTHERLY WINDS SHOULD OCCUR LATE THIS MORNING AS LOW PRESSURE
DEVELOPS SOUTHEAST OF CAPE FEAR AND DEEPENS AS IT MOVES EAST AND
FARTHER OFFSHORE.
RAIN FALLING ACROSS AL/GA/SC THIS MORNING IS HEADING OUR WAY.
ISENTROPIC LIFT ALONG THE 300-305K THETA SURFACES...APPROXIMATELY
9000-15000 FT ALOFT...APPEARS TO MATCH BEST WITH OBSERVED UPSTREAM
RADAR ECHOES. TRACKING THIS EASTWARD THROUGH THE DAY BRINGS RAIN
INTO THE AREA BETWEEN 8-9 AM...PEAKING IN COVERAGE AND INTENSITY
AROUND NOON...THEN DIMINISHING FROM NW TO SE DURING THE AFTERNOON.
THE NORTHERN EDGE OF MEASURABLE RAIN COULD BE VERY CLOSE TO
BENNETTSVILLE...LUMBERTON AND ELIZABETHTOWN...AND I THEREFORE ONLY
HAVE A FEW HUNDREDTHS OF AN INCH OF RAINFALL FORECAST FOR THESE
LOCATIONS. THE BEST RAINFALL IN MY FORECAST AREA SHOULD BE ALONG
THE SANTEE RIVER IN SOUTH CAROLINA WITH ABOUT THREE-TENTHS
EXPECTED. SKIES MAY BEGIN TO CLEAR ALONG I-95 DURING THE AFTERNOON
AS DRIER AIR WORKS ITS WAY IN ALOFT.
LOW-LEVEL DRY AIR STREAMING SOUTHWARD BEHIND THE SURFACE COLD
FRONT IS PROBABLY NOT DEEP ENOUGH TO AFFECT RAINFALL TOTALS BY
ITSELF... BUT AS RAIN FALLS INTO THIS DRY AIR EVAPORATIONAL
COOLING SHOULD CAUSE A FALLING TREND IN TEMPERATURES DURING THE
LATE MORNING. LOOK FOR NON-TYPICAL TEMPERATURE CURVES AS A
RESULT...PROBABLY SHAPED LIKE A "U" DURING THE DAYLIGHT HOURS
TODAY.
FOR TONIGHT MOISTURE SHOULD THIN FROM THE TOP DOWN WITH SKIES
CLEARING ALONG THE COAST. LIGHT WINDS OVERNIGHT AND A FAIRLY
CHILLY AIRMASS (850 MB TEMPS FALLING TO ZERO TO -4C) SHOULD ALLOW
LOWS TO REACH THE UPPER 20S FOR ALL BUT THE BEACHES. THE MODELS
ARE HINTING AT SOME THIN LOW LEVEL MOISTURE LINGERING ALONG THE
COAST WHICH COULD RESULT IN SOME OVERNIGHT FOG...PARTICULARLY IF
WINDS BECOME CALM.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 330 AM WEDNESDAY...AMPLIFIED MID TO UPPER LONGWAVE TROF
ACROSS THE FA ON THU...WILL DE-AMPLIFY SOME FRIDAY INTO FRIDAY
NIGHT. A RE-ENFORCING SHOT OF ARCTIC AND DRIER AIR FROM THE NW
THRU N...WILL PUSH ACROSS THE FA LATE THU AND/OR THU NIGHT. VERY
LITTLE CLOUDS AND NO PCPN WILL ACCOMPANY THIS CFP. WINTER TO
REMAIN ACTIVE WITH RESPECT TO THE COLD TEMPERATURES. HAVE STAYED
AT OR JUST ABOVE THE GFS TEMP MOS GUIDANCE...WHICH PRODUCES
MIN/MAX TEMPS LATE THU THROUGH MUCH OF FRI AT 10 TO POSSIBLY 15
DEGREES BELOW THE CLIMO NORMALS.
THE DRIER AIR THAT WORKS ACROSS THE FA THU AFTN AND AGAIN ON
FRI...COULD BECOME A FIRE HAZARD ESPECIALLY WITH SFC RHS FORECAST
TO DROP TO AROUND 25 PERCENT EACH AFTN. A LIGHT ONSHORE FLOW
DURING FRIDAY MAY HELP KEEP THE COASTAL COUNTIES SLIGHTLY HIGHER
IN THE RH DEPARTMENT. WILL NEED TO MONITOR.
THE MID TO UPPER FLOW BEGINS TO -AMPLIFY SOME FRI NIGHT WITH THE
SOUTHERN STREAM BECOMING A BIT MORE ACTIVE ACROSS THE FORECAST
AREA. TEMPS FRIDAY NITE/SAT MORNING WILL NOT BE AS COLD AS THU
NIGHT/FRI MORNING. AN INVERTED SFC TROF JUST OFF THE CAROLINA
COAST BY SAT MORNING COULD PUSH LOW CLOUDS ONSHORE BY DAYBREAK
SAT. A VERY LOW CHANCE WILL EXIST FOR PATCHY LIGHT RAIN DURING THE
PRE-DAWN SAT HRS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 345 AM WEDNESDAY...THE MID TO UPPER LONGWAVE TROF ACROSS THE
FA WILL CONTINUE TO DE-AMPLIFY THRU THE UPCOMING WEEKEND. THE
SOUTHERN STREAM MID TO UPPER FLOW BECOMES MORE ACTIVE THIS
WEEKEND...WITH UPPER RIDGING LIKELY TO EXTEND ACROSS THE FA FROM
THE GULF OF MEXICO. THIS WILL TEMPORARILY PREVENT POLAR/ARCTIC AIR
WITHIN THE NORTHERN STREAM FROM PUSHING TO THE SOUTHEAST
STATES...INCLUDING THE ILM CWA...DURING THIS WEEKEND. SOME WEAK
FORCING SAT COULD PRODUCE PATCHY LIGHT RAIN ACROSS THE FA AS THE
DYNAMICS FROM A MID TO UPPER S/W TROF CLIPPER TYPE SYSTEM REMAINS
WELL NORTH OF THE FA. DURING SAT...THE COASTAL TROF/FRONT OVER THE
ADJACENT ATL WATERS GETS PULLED TO THE NW-N AND INLAND...ACTING
SIMILAR TO A WARM FRONTAL PASSAGE. TEMPS WILL REBOUND THIS WEEKEND
AND CLIMB TO JUST BELOW NORMAL ON SAT...AND AT OR SLIGHTLY ABOVE
NORMAL ON SUN.
FOR MON INTO TUE...MODELS ARE QUITE DISSIMILAR WITH ONE ANOTHER
WITH RESPECT TO THE UPPER LONGWAVE PATTERN AS WELL AS THE UPPER
SHORT WAVE PATTERN THAT HELPS DEFINE/CONSTRUCT THIS LONGWAVE
PATTERN. AS A RESULT...HAVE STAYED CLOSER TO THE PREVIOUS
FORECAST. HAVE TWEAKED TEMPS SLIGHTLY UPWARD MONDAY AS LOW LEVEL
FLOW FROM THE SOUTH CONTINUES TO PUMP MILD AIR AND HIGHER
DEWPOINTS. WILL HAVE TO KEEP AN EYE ON TUE INTO WED AS A COLD
FRONT DROPS SOUTHWARD WHILE A MID TO UPPER LEVEL SOUTHERN STREAM
S/W TROF APPROACHES FROM THE WSW. WILL CONTINUE TO INDICATE CHANCE
POPS...WITH ABOVE FREEZING LIQUID RAIN RULING THE PCPN TYPE.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...LIGHT TO MODERATE STRATIFORM RAIN CONTINUES TO MOVE
ACROSS OUR CWA THIS AFTERNOON...WITH THE HEAVIEST/MOST PERSISTENT
RAIN OVER OUR SOUTHERN COUNTIES. THEREFORE...CIGS RANGE FROM VFR
AT KLBT TO MVFR/TEMPO IFR AT KCRE/KMYR. EXPECT MVFR CIGS TO
PREVAIL AT ALL SITES EXCEPT PERHAPS KLBT THIS AFTERNOON. RADAR
TRENDS AND HRRR RUNS INDICATE MOST OF THE PCPN AFTER 18Z WILL BE
FOCUSED ALONG THE COAST...SO WILL MAINTAIN LOWER MVFR CIGS AT
THESE SITES WITH TEMPO IFR AT KCRE AND KMYR. THE WINDS WILL REMAIN
NORTH 6-10 KTS INTO THE EVENING HOURS AS PCPN TAPERS OFF AND VFR
DEVELOPS FROM WEST TO EAST. FCST SOUNDINGS SHOW ENOUGH RESIDUAL
MOISTURE OVERNIGHT TO WARRANT A MENTION OF PATCHY FOG...SO HAVE
ADDED TEMPO MVFR VSBYS FOR ALL SITES BEFORE DAYBREAK. THURSDAY
WILL BE VFR WITH NORTHWEST WINDS AOB 8 KTS.
EXTENDED OUTLOOK...VFR ON FRIDAY. CHANCE OF RAIN/MVFR ON SATURDAY.
MVFR/IFR CIGS/VSBYS POSSIBLE ON SUNDAY. VFR ON MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 PM WEDNESDAY...HAVE DROPPED THE SMALL CRAFT ADVISORY
FORMERLY IN EFFECT FOR OUR NC WATERS IN FAVOR OF SCEC HEADLINES.
WINDS HAVE STAYED MAINLY IN THE 15 KT RANGE WITH 2 TO 4 FT SEAS SO
FAR. HOWEVER...A SURGE OF WIND THIS AFTERNOON MAY PUSH SEAS UP
INTO THE 3 TO 5 FT RANGE THROUGH THE EVENING HOURS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 345 AM WEDNESDAY...THURSDAY WILL FEATURE A REINFORCING SHOT
OF POLAR/ARCTIC AIR FROM HIGH PRESSURE THAT WILL FOLLOW AFTER THE
PASSAGE OF THE FRONT THU AFTN OR EARLY EVENING. SCEC OR EVEN SCA
CONDITIONS WILL MAKE AN APPEARANCE AFTER THE COLD FRONTAL
PASSAGE...AND COULD LAST THROUGH MUCH OF FRIDAY AS THE SFC PG TO
REMAIN TIGHTENED ACROSS THE WATERS AS RIDGING FROM THE 1030+ HIGH
CENTERED OVER THE NE STATES FLEXES ITS MUSCLE. SIGNIFICANT SEAS
WILL BUILD RATHER QUICKLY THU NIGHT THRU FRIDAY...WITH NE-E
LOCALLY PRODUCED WIND DRIVEN SHORT PERIOD WAVES DOMINATING THE
SEAS SPECTRUM. WILL HIGHLIGHT THE SCEC/SCA POSSIBILITY IN THE HWO.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 415 AM WEDNESDAY...COASTAL TROF/FRONT WILL DEVELOP OFF THE
CAROLINA COAST SATURDAY...AND LIFT AND/OR SWEEP ACROSS THE AREA
WATERS AND INLAND DURING SAT INTO EARLY SUN. BY SUNDAY...FLOW
ACROSS THE WATERS WILL HAVE VEERED TO THE SE-SSW. THIS A RESULT OF
SFC HIGH PRESSURE TEMPORARILY CENTERED OFFSHORE FROM THE SE U.S.
COAST...AND HAVING BECOME THE PRIMARY DRIVER FOR WINDS ACROSS THE
AREA WATERS. THE ONSHORE FLOW WILL HELP KEEP SIGNIFICANT SEAS
SOMEWHAT ELEVATED BUT LIKELY REMAINING JUST BELOW SCEC/SCA
THRESHOLDS.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DCH
NEAR TERM...REK/TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...BJR
MARINE...DCH/REK/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
938 PM CST THU FEB 27 2014
.UPDATE...
ISSUED AT 929 PM CST THU FEB 27 2014
SURFACE OBSERVATIONS ACROSS SASKATCHEWAN AND NORTHERN MONTANA SHOW
THE INCREASING NORTHWEST WINDS BEHIND THE FRONTAL PASSAGE. THE
STRONGEST WINDS ARE IN THE NEIGHBORHOOD OF THE FORECAST 6 MB
PRESSURE RISE NEAR HAVRE. THE RAP PRESSURE RISE REACHES WESTERN
NORTH DAKOTA AROUND 10Z AND SHOULD SEE WINDS AND COLDER AIR ARRIVE
THEN. CURRENT FORECAST TRENDING WELL.
UPDATE ISSUED AT 632 PM CST THU FEB 27 2014
HIGH PRESSURE ACROSS MINNESOTA WAS RETREATING TO THE EAST THIS
THURSDAY EVENING. A COLD FRONT ACROSS SOUTHWEST SASKATCHEWAN INTO
NORTH CENTRAL MONTANA IS FORECAST TO MOVE SOUTHEAST INTO WESTERN
NORTH DAKOTA BEFORE SUNRISE BRINGING A WIND SHIFT TO THE NORTHWEST
AND INCREASING WINDS. THIS WILL FOCUS THE COLDEST WIND CHILL
TEMPERATURES ACROSS THE NORTHWEST. FOR THIS UPDATE...ADJUSTED
CLOUDS TO SATELLITE TRENDS OTHERWISE CURRENT FORECAST LOOKS GOOD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 220 PM CST THU FEB 27 2014
THE MAIN FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD IS THE
PASSAGE OF A STRONG COLD FRONT AND ASSOCIATED TEMP/WIND CHILL ISSUES.
SOUTHERLY WINDS AHEAD OF THE FRONT AND INCREASING CLOUDS SHOULD
PRECLUDE ANY BITTERLY COLD TEMPERATURES TONIGHT...COMPARED WITH
LAST NIGHT. WITH THE COMBINED EFFECTS OF LOW LEVEL MIXING AND
CLOUD COVER...HAVE RAISED OVERNIGHT LOWS FROM THE PREVIOUS
FORECAST. AFTER MIDNIGHT...THE FRONT WILL MOVE FROM WEST TO EAST
ACROSS THE STATE AND REACH THE JAMES RIVER VALLEY AROUND 12Z. THE
NAM IS FORECASTING MAX 6-7MB 3 HOUR PRESSURE RISES ASSOCIATED WITH
THE FRONT. HAVE INCREASED WINDS SLIGHTLY...NOW EXPECTING SUSTAINED
AROUND 25 MPH...GUSTS TO 40 MPH. THERE MAY BE SOME LIGHT SNOW
ACCUMULATIONS IN THE EXTREME SOUTHWEST LATE TONIGHT AND FRIDAY.
HAVE ALSO ADDED PATCHY BLOWING SNOW THERE DUE TO THE ROBUST WINDS.
ALTHOUGH FORECAST TEMPS ARE A BIT HIGHER OVERNIGHT...THE STRONG
WIND IS RESULTING IN WIND CHILL VALUES AROUND 30 BELOW ZERO OVER
NORTH CENTRAL NORTH DAKOTA...MAINLY DURING THE MORNING HOURS FRIDAY.
WILL LIKELY ISSUE AN ADVISORY...WITH FINAL COUNTIES TO BE DETERMINED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 250 PM CST THU FEB 27 2014
FOCUS IN THE LONG TERM WILL BE ON THE FRIGID TEMPERATURES EXPECTED
FRIDAY NIGHT AND OVER THE WEEKEND AND THE CHANCES FOR SNOW OVER THE
WEEKEND AND INTO NEXT WEEK
DEEP UPPER LEVEL LOW OVER HUDSON BAY WILL EJECT SOME OF THE COLDEST
AIR IN THE NORTHERN HEMISPHERE OVER NORTH DAKOTA FOR FRIDAY NIGHT
AND SATURDAY NIGHT. 12 UTC MID RANGE MODEL SUITE IS IN GOOD
AGREEMENT OF THE MOST FRIGID AIR MOVING IN NORTH TO SOUTH SATURDAY
BETWEEN 00 AND 12 UTC. 12 UTC MODEL SUITE SHOWS THE UPPER LEVEL
PATTERN SWITCHING TO MORE ZONAL FLOW AROUND 18 UTC
SATURDAY...ALLOWING THE FRIGID AIR TO STICK AROUND THROUGH SUNDAY 12
UTC.
EVEN WITH THE LIGHT NORTH WINDS...WIND CHILLS FRIDAY NIGHT AND
SATURDAY NIGHT WILL APPROACH 40 TO 50 BELOW ZERO ACROSS THE NORTH
AND PARTS OF THE JAMES RIVER VALLEY. WIND CHILL ADVISORY HEADLINES
ARE ALL BUT GUARANTEED ACROSS CENTRAL AND WESTERN NORTH DAKOTA FRIDAY
NIGHT AND SATURDAY NIGHT. THE MAJORITY OF CENTRAL AND WESTERN NORTH
DAKOTA WILL BE IN WIND CHILL ADVISORY CRITERIA FROM FRIDAY NIGHT
INTO SUNDAY MORNING. THUS AN EXTENDED WIND CHILL ADVISORY COULD BE
THE SOLUTION TO THE LONG LIVED FRIGID WIND CHILLS. ACROSS THE NORTH
AND PARTS OF THE JAMES RIVER VALLEY WIND CHILL WARNING HEADLINES MAY
BE POSSIBLE FOR FRIDAY NIGHT AND AGAIN ON SATURDAY NIGHT.
MID RANGE MODELS ARE IN GOOD AGREEMENT OF A SYSTEM PASSING TO OUR
SOUTH FRIDAY THROUGH THE WEEKEND. THE INCOMING DRY ARCTIC AIR WILL
KEEP THE MAJORITY OF THE STATE DRY. HOWEVER...MODELS SOLUTIONS DO
BRING A CHANCE OF SNOW INTO THE SOUTHWEST AND PARTS OF SOUTH CENTRAL
STARTING TONIGHT. CHANCES WILL STICK AROUND THROUGH THE
WEEKEND...WITH SNOW ACCUMULATIONS OVER THE PERIOD FROM 3.5 INCHES TO
TRACE AMOUNTS.
THE LATEST 12 UTC GFS HAS NOW COME IN LINE WITH THE 12 UTC ECMWF
PROGGING AN UPPER LOW TO PINCH OFF AND BECOME STATIONARY OVER THE
CANADIAN ROCKIES. THIS FEATURE WILL GENERATE QUASI-ZONAL FLOW OVER
NORTH DAKOTA DURING THE FIRST HALF OF NEXT WEEK. SHORTWAVES
EMANATING FROM THE UPPER LOW ARE PROGGED TO TRAVERSE THE STATE EACH
DAY THROUGH WEDNESDAY. THIS SOLUTION SUGGESTS A MORE ACTIVE PATTERN
THAN PREVIOUS SOLUTIONS FOR THE FIRST HALF OF NEXT WEEK...GIVING
CHANCES FOR SNOW ACROSS CENTRAL AND WESTERN NORTH DAKOTA THROUGH THE
EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 929 PM CST THU FEB 27 2014
AT 9 PM CST...A COLD FRONT EXTENDED ACROSS SOUTH CENTRAL SASKATCHEWAN
INTO NORTHEAST MONTANA. THE COLD FRONT WILL BE THE FOCUS FOR MVFR
CEILINGS AND GUSTY NORTHWEST WINDS MOVING PROGRESSIVELY ACROSS THE
REGION AFTER 10Z FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 4 AM TO NOON CST FRIDAY FOR NDZ001>004-
009>012.
&&
$$
UPDATE...WAA
SHORT TERM...RP KINNEY
LONG TERM...MM
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
113 PM CST WED FEB 26 2014
.UPDATE...
ISSUED AT 110 PM CST WED FEB 26 2014
HAVE EXTENDED THE WIND ADVISORY INTO THE EVENING. WILL EXPECT A
QUICK DROP IN SPEEDS AROUND 7 PM CST...EVEN A BIT BEFORE THAT IN
THE NORTHWEST...WILLISTON AREA. WILL NEED TO POST ANOTHER WIND
CHILL ADVISORY FOR TONIGHT INTO THURSDAY MORNING. AM WORKING OUT
APPARENT TEMPERATURES NOW TO SEE WHAT AREAS CAN BE LEFT OUT OF
IT.
UPDATE ISSUED AT 1121 AM CST WED FEB 26 2014
WIND SPEEDS WERE RUNNING OVER FORECAST AND I DO NOT SEE WHY THEY
WOULD DROP MUCH THE REST OF THE AFTERNOON. HAVE DECIDED TO EXPAND
THE WIND ADVISORY A COUNTY OR TWO TO THE WEST OF WHAT IT WAS. THIS
WILL NOW PLACE MOHALL...MINOT...GARRISON...STEELE...AND WISHEK IN
THE ADVISORY.
UPDATE ISSUED AT 1035 AM CST WED FEB 26 2014
HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON
SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF
TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW
FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST.
SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING
VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE
COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS
LAKE BASIN.
HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL.
WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING.
UPDATE ISSUED AT 637 AM CST WED FEB 26 2014
THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE.
IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE
WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A
RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE
REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON
CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CST WED FEB 26 2014
THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE
WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID
MORNING INTO THE AFTERNOON.
EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN
NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS
EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN
INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES.
FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE
WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE
GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER
WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND
CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND
EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35
BELOW.
WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR
ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST
PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH
DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW
LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY
AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS
OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY
LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE
STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST
AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY
ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES.
WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND
REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO
1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY.
IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY
FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER.
WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A
HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS
WILL HAVE TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CST WED FEB 26 2014
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED
WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND.
SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN
APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION
IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS
WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING
WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM
RANGE MODELS MAINTAIN A DRY FROPA.
WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED
TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT.
THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A
CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE
SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END
OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH
AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE
NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE
UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY
THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO
RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW
CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH
DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION
VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE
END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 110 PM CST WED FEB 26 2014
STRONG NORTHWEST WINDS ARE FORECAST UNTIL 01Z/27TH...AFTER WHICH
TIME THEY WILL BE RAPIDLY DECREASING. STRONGEST WINDS WILL OCCUR
FROM KMOT TO KJMS WHERE PATCHY BLOWING SNOW IS POSSIBLE BUT WITH NO
SIGNIFICANT REDUCTION IN VISIBILITY. VFR CIGS AND VSBYS WILL
CONTINUE THROUGH THE TAF VALID PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM CST THIS EVENING FOR NDZ002>005-011>013-
021>023-025-036-037-047-048-050-051.
&&
$$
UPDATE...JPM
SHORT TERM...CK
LONG TERM...TM
AVIATION...JPM/ACOOP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1124 AM CST WED FEB 26 2014
.UPDATE...
ISSUED AT 1121 AM CST WED FEB 26 2014
WIND SPEEDS WERE RUNNING OVER FORECAST AND I DO NOT SEE WHY THEY
WOULD DROP MUCH THE REST OF THE AFTERNOON. HAVE DECIDED TO EXPAND
THE WIND ADVISORY A COUNTY OR TWO TO THE WEST OF WHAT IT WAS. THIS
WILL NOW PLACE MOHALL...MINOT...GARRISON...STEELE...AND WISHEK IN
THE ADVISORY.
UPDATE ISSUED AT 1035 AM CST WED FEB 26 2014
HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON
SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF
TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW
FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST.
SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING
VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE
COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS
LAKE BASIN.
HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL.
WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING.
UPDATE ISSUED AT 637 AM CST WED FEB 26 2014
THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE.
IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE
WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A
RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE
REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON
CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CST WED FEB 26 2014
THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE
WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID
MORNING INTO THE AFTERNOON.
EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN
NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS
EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN
INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES.
FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE
WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE
GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER
WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND
CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND
EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35
BELOW.
WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR
ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST
PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH
DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW
LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY
AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS
OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY
LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE
STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST
AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY
ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES.
WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND
REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO
1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY.
IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY
FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER.
WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A
HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS
WILL HAVE TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CST WED FEB 26 2014
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED
WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND.
SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN
APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION
IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS
WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING
WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM
RANGE MODELS MAINTAIN A DRY FROPA.
WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED
TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT.
THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A
CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE
SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END
OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH
AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE
NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE
UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY
THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO
RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW
CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH
DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION
VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE
END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1035 AM CST WED FEB 26 2014
VFR AT ALL TAF SITES THROUGH THE FORECAST VALID PERIOD UNDER A
MOSTLY CLEAR SKY. THE MAIN CONCERN THROUGH 02Z/27TH IS GUSTY
NORTHWEST WINDS...ESPECIALLY OVER THE EASTERN HALF OF NORTH DAKOTA.
SPEEDS WILL BE AROUND 25 KNOTS...GUSTING 35 KNOTS. THIS WILL
CREATE PATCHES OF BLOWING SNOW. NOTE THAT KMOT HAS BEEN REPORTING
-SN BUT THAT IS NOT FALLING SNOW...IT IS SNOW BEING BLOWN INTO THE
ASOS SENSOR. VSBY AT KMOT WAS STILL P6SM. SIMILAR THING COULD
HAPPEN AT KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ002>005-011>013-
021>023-025-036-037-047-048-050-051.
&&
$$
UPDATE...JPM
SHORT TERM...CK
LONG TERM...TM
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1043 AM CST WED FEB 26 2014
.UPDATE...
ISSUED AT 1035 AM CST WED FEB 26 2014
HAVE UPDATED TO REMOVE THE WIND CHILL ADVISORY. BASED ON
SURFACE OBSERVATION REPORTS AND NORTH DAKOTA DEPARTMENT OF
TRANSPORTATION WEB CAMS...HAVE DECREASED THE PATCHY BLOWING SNOW
FROM THE WEST AND DECREASED THE AREAS OF BLOWING SNOW IN THE EAST.
SOME OF THE CAMERA IMAGES LOOK MILKY BUT NOTHING DECREASING
VISIBILITY TO ANYTHING HAVING AN IMPACT. ROLLA...ROLETTE
COUNTY...WAS REPORTING REDUCED VISIBILITY...ON INTO THE DEVILS
LAKE BASIN.
HAVE ALSO DECREASED CLOUD COVER TODAY WEST INTO CENTRAL.
WILL NEED ANOTHER WIND CHILL ADVISORY FOR WEDNESDAY NIGHT INTO
THURSDAY MORNING.
UPDATE ISSUED AT 637 AM CST WED FEB 26 2014
THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE.
IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE
WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A
RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE
REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON
CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CST WED FEB 26 2014
THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE
WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID
MORNING INTO THE AFTERNOON.
EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN
NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS
EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN
INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES.
FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE
WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE
GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER
WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND
CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND
EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35
BELOW.
WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR
ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST
PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH
DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW
LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY
AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS
OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY
LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE
STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST
AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY
ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES.
WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND
REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO
1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY.
IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY
FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER.
WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A
HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS
WILL HAVE TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CST WED FEB 26 2014
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED
WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND.
SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN
APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION
IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS
WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING
WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM
RANGE MODELS MAINTAIN A DRY FROPA.
WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED
TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT.
THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A
CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE
SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END
OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH
AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE
NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE
UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY
THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO
RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW
CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH
DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION
VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE
END OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1035 AM CST WED FEB 26 2014
VFR AT ALL TAF SITES THROUGH THE FORECAST VALID PERIOD UNDER A
MOSTLY CLEAR SKY. THE MAIN CONCERN THROUGH 02Z/27TH IS GUSTY
NORTHWEST WINDS...ESPECIALLY OVER THE EASTERN HALF OF NORTH DAKOTA.
SPEEDS WILL BE AROUND 25 KNOTS...GUSTING 35 KNOTS. THIS WILL
CREATE PATCHES OF BLOWING SNOW. NOTE THAT KMOT HAS BEEN REPORTING
-SN BUT THAT IS NOT FALLING SNOW...IT IS SNOW BEING BLOWN INTO THE
ASOS SENSOR. VSBY AT KMOT WAS STILL P6SM. SIMILAR THING COULD
HAPPEN AT KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR NDZ004-005-012-013-
022-023-025-037-048-051.
&&
$$
UPDATE...JPM
SHORT TERM...CK
LONG TERM...TM
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
637 AM CST WED FEB 26 2014
.UPDATE...
ISSUED AT 637 AM CST WED FEB 26 2014
THE ONGOING WIND CHILL ADVISORY STILL LOOKS GOOD FOR THIS UPDATE.
IN ADDITION...INCREASING ISALLOBARIC WINDS STILL LOOK TO GENERATE
WINDS MEETING WIND ADVISORY CRITERIA EAST THIS AFTERNOON. AS A
RESULT...WILL LEAVE THE CURRENT HEADLINES AS IS FOR THIS UPDATE.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. NO MAJOR UPDATES WERE
REQUIRED. ONLY ADJUSTED THE HOURLY SENSIBLE WEATHER GRIDS BASED ON
CURRENT OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CST WED FEB 26 2014
THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE
WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID
MORNING INTO THE AFTERNOON.
EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN
NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS
EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN
INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES.
FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE
WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE
GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER
WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND
CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND
EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35
BELOW.
WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR
ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST
PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH
DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW
LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY
AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS
OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY
LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE
STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST
AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY
ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES.
WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND
REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO
1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY.
IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY
FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER.
WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A
HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS
WILL HAVE TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CST WED FEB 26 2014
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED
WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND.
SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN
APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION
IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS
WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING
WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM
RANGE MODELS MAINTAIN A DRY FROPA.
WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED
TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT.
THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A
CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE
SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END
OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH
AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE
NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE
UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY
THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO
RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW
CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH
DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION
VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE
END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 637 AM CST WED FEB 26 2014
MAINLY CLEAR SKIES ARE EXPECTED AT THE TERMINAL LOCATIONS. THE MAIN
CONCERN WILL BE INCREASING WINDS AS A COLD FRONT MOVES ACROSS THE
REGION. WINDS WILL BECOME GUSTY FROM THE NORTHWEST...WITH THE
STRONGEST WINDS EXPECTED FROM KMOT TO KJMS. CONTINUED TO CARRY THE
6SM IN BLSN AT KMOT AND KJMS ONCE THE WINDS INCREASE. WINDS WILL
DIMINISH THIS WEDNESDAY EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ001>005-
009>013-021>023-025-035>037-046>048-050-051.
WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NDZ004-005-012-013-022-023-025-037-048-051.
&&
$$
UPDATE...TM
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
314 AM CST WED FEB 26 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CST WED FEB 26 2014
THERE ARE SEVERAL CONCERNS IN THE SHORT TERM PERIOD INCLUDING THE
WIND CHILL ADVISORY THIS MORNING...FOLLOWED BY WINDS FROM MID
MORNING INTO THE AFTERNOON.
EARLY MORNING SURFACE ANALYSIS PLACED HIGH PRESSURE FROM SOUTHERN
NORTH DAKOTA SOUTHWARD INTO THE CENTRAL PLAINS. A COLD FRONT IS
EXPECTED TO MOVE ACROSS THE FORECAST AREA TODAY...BRINGING AN
INCREASE IN NORTHWEST WINDS AS THE FRONT PASSES.
FIRST REGARDING THE WIND CHILL ADVISORY...THE HEADLINE LOOKS TO BE
WELL PLACED. WIND CHILLS SOUTH AND WEST OF THE MISSOURI RIVER HAVE
GENERALLY REMAINED WARMER THAN ADVISORY LEVELS DUE IN PART TO WEAKER
WINDS IN PROXIMITY TO THE SURFACE RIDGE AXIS. WILL LEAVE THE WIND
CHILL ADVISORY IN ITS CURRENT CONFIGURATION SINCE AREAS NORTH AND
EAST OF THE MISSOURI RIVER CONTINUE TO SEE WIND CHILLS OF 25 TO 35
BELOW.
WINDS SPEEDS WILL BE THE NEXT CONCERN AS LOW LEVEL COLD AIR
ADVECTION TAKES HOLD BEHIND THE COLD FRONT. THE STRONGEST
PRESSURE RISE / FALL COUPLET IS ACROSS MINNESOTA INTO EASTERN NORTH
DAKOTA...BUT CLIPS THE EASTERN PART OF THE FORECAST AREA. LOW
LEVEL LAPSE RATES ALSO BECOME STEEPEST FROM THE JAMES RIVER VALLEY
AND EAST. MOMENTUM TRANSFER FROM RAP BUFR SOUNDINGS SUGGEST AREAS
OUTSIDE OF THE ADVISORY COULD BRIEFLY APPROACH ADVISORY
LEVELS...BUT THAT APPEARS SHORT LIVED AND THINK THE HEART OF THE
STRONGEST WINDS SHOULD BE IN THE EASTERN PART OF THE FORECAST
AREA. WILL ONLY MAKE A SMALL ADJUSTMENT TO THE WIND ADVISORY BY
ADDING DICKEY COUNTY WHICH LINES UP WELL WITH SURROUNDING OFFICES.
WILL CONTINUE TO MENTION THE POSSIBILITY OF BLOWING SNOW AND
REDUCED VISIBILITIES...BUT DO NOT THINK VISIBILITIES SHOULD FALL TO
1/2SM OR BELOW...SO DID NOT GO WITH A WINTER WEATHER ADVISORY.
IT WILL BE COLD AGAIN TONIGHT WITH WIND CHILLS AGAIN POTENTIALLY
FALLING TO ADVISORY LEVELS NORTH AND EAST OF THE MISSOURI RIVER.
WITH MULTIPLE HEADLINES ALREADY IN PLACE...DID NOT PUT OUT A
HEADLINE FOR THE WIND CHILLS TONIGHT...BUT EXPECT LATER SHIFTS
WILL HAVE TO CONSIDER THAT POSSIBILITY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 314 AM CST WED FEB 26 2014
WELL BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH THE EXTENDED
WITH SNOW CHANCES STILL ON TAP FOR THIS WEEKEND.
SOUTHERLY RETURN FLOW WILL INCREASE THURSDAY AHEAD OF AN
APPROACHING COLD FRONT. NOT MUCH IN THE WAY OF WARM AIR ADVECTION
IS FORECAST WITH HIGHS FROM AROUND ZERO EAST TO THE LOW TEENS
WEST. THE COLD FRONT WILL PUSH THROUGH THE STATE FRIDAY MORNING
WITH BREEZY CONDITIONS EXPECTED TO DEVELOP IN ITS WAKE. THE MEDIUM
RANGE MODELS MAINTAIN A DRY FROPA.
WITH THE SURGE OF ARCTIC AIR...A BAROCLINIC ZONE IS STILL PROGGED
TO SET UP OVER SOUTHWESTERN NORTH DAKOTA FRIDAY AFTERNOON/NIGHT.
THIS SHOULD PROVIDE ENOUGH ELEVATED CONVERGENCE TO GENERATE A
CHANCE OF SNOW SOUTHWEST LATE FRIDAY INTO SATURDAY.
THE MEDIUM RANGE MODELS BEGIN TO DIVERGE WITH RESPECT TO THE
SYNOPTIC PATTERN OVER THE NORTHERN PLAINS SUNDAY THROUGH THE END
OF THE PERIOD. THE LATEST GFS IS DEEPER AND MORE PROGRESSIVE WITH
AN UPPER LOW OVER THE CANADIAN ROCKIES SATURDAY MOVING THROUGH THE
NORTHERN PLAINS SUNDAY. HOWEVER...THE LATEST ECMWF PINCHES OFF THE
UPPER LOW OVER THE CANADIAN ROCKIES WHERE IT BECOMES STATIONARY
THROUGH THE END OF THE PERIOD. GIVEN THE MODEL TO MODEL AND RUN TO
RUN INCONSISTENCIES...FORECAST A BLEND OF SOLUTIONS WITH SNOW
CHANCES SUNDAY...AND DRY CONDITIONS OVER WESTERN AND CENTRAL NORTH
DAKOTA MONDAY AND TUESDAY. REGARDLESS OF WHICH SOLUTION
VERIFIES...WELL BELOW TEMPERATURES ARE STILL FORECAST THROUGH THE
END OF THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 314 AM CST WED FEB 26 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE FORECAST PERIOD. THE MAIN
CONCERN WILL BE INCREASING WINDS AS NORTHWEST WINDS INCREASE BY
MID MORNING WEDNESDAY AND CONTINUE INTO THE AFTERNOON. CURRENTLY
IT LOOKS LIKE THE STRONGEST WINDS WILL PREVAIL FROM KMOT-
KJMS...THOUGH ALL LOCATIONS WILL SEE WINDS BECOME GUSTY. HELD ONTO
THE 6SM IN BLSN FOR KMOT AND KJMS ONCE THE WINDS INCREASE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR NDZ001>005-
009>013-021>023-025-035>037-046>048-050-051.
WIND ADVISORY FROM 10 AM THIS MORNING TO 6 PM CST THIS EVENING
FOR NDZ004-005-012-013-022-023-025-037-048-051.
&&
$$
SHORT TERM...CK
LONG TERM...TM
AVIATION...CK
AREA FORECAST DISCUSSION
NWS PORTLAND OR
218 AM PST WED FEB 26 2014
.SYNOPSIS...HIGH PRESSURE ALOFT WILL SHIFT EAST TODAY AS AN ELONGATED
FRONTAL SYSTEM MOVES CLOSER TO THE COAST. OFFSHORE LOW-LEVEL FLOW
CONTINUES TODAY...BUT WEAKENS IN THE AFTERNOON. A SERIES OF WEAK
IMPULSES WITHIN THE SOUTH FLOW ALOFT WILL TRAVERSE THE AREA TODAY FOR
A THREAT OF LIGHT RAIN...MAINLY OVER THE COAST AND COAST RANGE. THE
UPPER LOW ENTERS SW OREGON OVERNIGHT INCREASING THE RAIN THREAT OVER
THE AREA. A LOW PRESSURE AREA REMAINS PARKED OFF THE NRN CALIFORNIA
OR FAR SOUTH OREGON COAST THURSDAY. WEAK HIGH PRESSURE RETURNS
FRIDAY. IT LOOKS LIKE MUCH COOLER AIR WILL WORK ITS WAY INTO THE
WASHINGTON ZONES AND INTO THE COLUMBIA GORGE OVER THE WEEKEND. MILDER
WEST FLOW ALOFT RETURNS EARLY NEXT WEEK.
&&
.SHORT TERM...WEDNESDAY THROUGH FRIDAY...THE FORECAST AREA REMAINS
UNDER A LARGE-SCALE BLOCKING PATTERN EARLY THIS MORNING. WATER VAPOR
IMAGERY WITH 500 MB HEIGHT LINES SHOWS AN UPPER RIDGE AXIS FROM NEAR
VANCOUVER ISLAND THROUGH THE WASHINGTON CASCADES AND TO FAR SERN
OREGON. MEANWHILE...A SPLITTING UPPER TROUGH RESIDES OUT NEAR 140W
WITH THE MAIN ENERGY ALONG 40N. FINALLY...THE LARGE HUDSON BAY LOW IS
KEEPING EVERYTHING IN PLACE.
THE GFS AND 03Z HRRR BOTH INDICATE A BAND OF PRECIP MOVING INTO THE
SWRN PART OF THE AREA BETWEEN 15Z AND 18Z THIS MORNING. THE HRRR
SHOWS THIS LIGHT PRECIP ACTIVITY REACHING THE CENTRAL OREGON COAST
AND COAST RANGE AROUND 15Z...THEN DRIFTING E TO NE THROUGH THE
MORNING. TIME-HEIGHT...CROSS-SECTION AND MODEL SOUNDING ANALYSIS ALL
INDICATE MID-LEVEL MOISTURE...700-800 MB...REACHING THE CENTRAL COAST
BY SUNRISE. THE COLUMN CONTINUES TO SATURATE FROM THE TOP DOWN
THROUGH THE MORNING. THIS PRECIP ACTIVITY SHOULD NOT AMOUNT TO
MUCH...BUT WILL BE AIDED BY UPPER LEVEL DIVERGENCE. THIS PRECIP WILL
ENCOUNTER THE MODERATE OFFSHORE LOW-LEVEL FLOW AS IT DRIFTS N TOWARD
THE COLUMBIA RIVER. BEST CHANCES FOR PRECIP THIS AFTERNOON WILL BE
OVER THE FAR SOUTH AND ALSO ALONG THE CASCADES.
THE KTTD-KDLS GRADIENT WAS -9.3 MB AT 09Z. CORBETT GUSTING TO NEAR 55
MPH...WITH SEVERAL LOCATIONS IN THE EAST PORTLAND AND VANCOUVER METRO
AREA GUSING TO AT LEAST 35 MPH. PEAK OFFSHORE GRADIENT VIA THE LATEST
NAM LOOKS TO BE THIS MORNING. NAM DROPS THE KTTD-KDLS GRADIENT TO 4-5
MB BY 21Z. MAY NOT DROP QUITE THAT FAST...BUT THE AM CONFIDENT WIND
WILL EASE THIS AFTERNOON.
PATTERN CHANGES TONIGHT AND THU AS THE UPPER RIDGE AXIS FINALLY
SHIFTS TO THE EAST. GFS AND ECMWF SHOW A 500 MB LOW PRES AREA FORMING
NEAR 40N 127W BY 06Z THU. SOUTH DIFFLUENT FLOW ALOFT BECOMES MORE
PRONOUNCED THIS EVENING AS THE LOW MOVES CLOSER TO THE N CA AND FAR
SRN OREGON COAST. EXPECT PRECIP TO SPREAD NWD THIS EVENING AND
TONIGHT. MODELS CLEARLY SHOW A DEFORMATION BAND SETTING UP ACROSS THE
CENTRAL PORTION OF THE AREA AROUND MIDNIGHT THEN DRIFTING NWD
OVERNIGHT AND FINALLY MOVING INTO SW WA THU MORNING. MODELS TREAT THE
UPPER LOW A BIT DIFFERENT...BUT BOTH THE GFS AND ECMWF SHOW THE LOW
FILLING AND BECOMING AN OPEN TROUGH 18Z THU AS IT DRIFT N TO NE
THROUGH SWRN OREGON. EXPECT PRECIP TO SLOWLY WANE FROM S TO N THU
AFTERNOON AND EVENING. LARGE-SCALE PATTERN REVERTS TO SOMETHING CLOSE
TO WHAT IT IS NOW THU NIGHT. INTERESTING SYNOPTIC SITUATION SETS UP
LATE THU NIGHT AND FRI. MODELS SHOW A CLOSED LOW OUT NEAR 35N
130W...A PINCHED-OFF RIDGE IN THE GULF OF ALASKA AND A LARGE BUT COLD
CANADIAN TROUGH TRYING TO RETROGRADE TO THE WEST. GFS AND ECMWF
SUGGEST SOME OF THIS COLDER AIR MAY START TO FILTER IN CENTRAL
WASHINGTON FRI AND THEN SLIDE SOUTH ALONG THE CASCADES AND INTO THE
CENTRAL COLUMBIA GORGE BY 00Z SAT. WEISHAAR
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...MUCH OF THE EXCITEMENT
FOR THE EXTENDED OCCURS THIS UPCOMING WEEKEND AND MONDAY. THE COLD
AIR MENTIONED ABOVE IN THE SHORT-TERM SECTION BECOMES MORE
ESTABLISHED OVER THE WEEKEND. LOOKS TO BE A SIMILAR SCENARIO TO THIS
PAST SUNDAY AND MONDAY WITH A SNOW-THREAT FOR THE UPPER HOOD RIVER
VALLEY. THIS COLDER AIR WILL CONTINUE TO SPILL INTO THE COLUMBIA
GORGE THIS WEEKEND. MODELS HAVE MAJOR DIFFERENCES HANDLING THE COLD
AIR SUNDAY. GFS FORCES THE MILDER WESTERLIES INTO THE PAC NW SUN
WHILE THE ECMWF CONTINUES TO RETROGRADE THE COLD UPPER LOW INTO SRN
B.C....WITH A DISTINCT COLD AIR BOUNDARY ACROSS WRN WA. ECMWF ALSO
SHOWS SOME OVER-RUNNING PRECIP MOVING INTO WRN WA AND OREGON SUN.
THIS WOULD BE A PRIME POTENTIAL SNOW SITUATION FOR SWRN WA AND IN THE
COLUMBIA GORGE SHOULD THE ECMWF VERIFY. THE GEM IS MORE LIKE THE
GFS...SHUNTING THE COLD AIR FURTHER TO THE EAST SUN. MONDAY COULD
ALSO BE A GOOD SNOW SITUATION FOR SWRN WA AND AREAS NEAR THE COLUMBIA
GORGE IF THE ECMWF IS RIGHT. HOWEVER...THE GFS IS NEARLY 24-HRS
SLOWER COMPARED TO THE ECMWF. ALL IN ALL...FORECASTER CONFIDENCE IS
RATHER LOW SUNDAY AND BEYOND. WEISHAAR
&&
.AVIATION...EAST WINDS ARE THE MAIN AVIATION IMPACT TODAY. THESE
WINDS ARE STRONGEST IN THE NORTHERN PORTION OF THE FORECAST
AREA...WITH THE GREATEST IMPACTS FOR KTTD AND KPDX. EAST WINDS
GUSTY AT TIMES WILL PERSIST THROUGH THE MORNING...EASING IN THE
AFTERNOON. OTHERWISE VFR CONDITIONS WITH MAINLY THIN AND HIGH
CLOUDS. THE EAST WINDS HAVE DRIED THE LOWER LEVELS SOME...AND DO
NOT EXPECT ANY FOG THIS MORNING. A FRONT WILL BRING A CHANCE OF
RAIN FROM THE SOUTH EARLY THIS AFTERNOON THEN TO THE NORTH MAINLY
OVER THE CASCADES AND COAST RANGE LATER THIS AFTERNOON. CIGS WILL
LOWER AS THE FRONT NEARS BUT EXPECT CONDITIONS TO GENERALLY REMAIN
VFR. THERE WILL BE MORE WIDESPREAD RAIN WITH MVFR CONDITIONS LATE
TONIGHT INTO THU MORNING.
KPDX AND APPROACHES...VFR WITH EAST WINDS 10 TO 20 KT THROUGH
THIS MORNING. WINDS WILL EASE THIS AFTERNOON. CLOUDS WILL INCREASE
IN THE AFTERNOON AS A FRONT BUT EXPECT CONDITIONS TO REMAIN VFR.
THERE IS A SLIGHT CHANCE OF A FEW SPRINKLES AFT 22Z.THERE WILL BE
A GREATER CHANCE FOR RAIN AND MVFR CONDITIONS LATE TONIGHT INTO
THU MORNING. HARTLEY
&&
.MARINE...OFFSHORE WINDS CONTINUE MARGINAL SMALL CRAFT CONDITIONS
NORTH OF CANNON BEACH THIS MORNING. THE SURFACE PRESSURE GRADIENT
WILL RELAX LATER THIS MORNING AS THE HIGH PRESSURE INLAND WEAKENS
AND SHIFTS TO THE NE...AND THE WINDS WILL EASE. RELATIVELY LIGHT
E-SE WINDS WILL CONTINUE THROUGH THURSDAY NIGHT.
A COMPLEX LOW OFFSHORE HAS GENERATED A W-SW SWELL THAT WILL BUILD
IN THE WATERS TODAY. ALTHOUGH THE BUOYS THE PAST 12 HOURS HAVE
SHOWN THE SEAS TO BE A COUPLE OF FEET LOWER THAN GUIDANCE...THERE
IS SOME EVIDENCE THAT THE FORECAST SWELL IS ON THE WAY. A BUOY FAR
TO THE SE OF THE WATERS..46002 HAS BEEN REPORTING 14 TO 16 FT AT
15 SECONDS AS THE ENP FORECASTED. THE DIRECTION OF THIS BUOY FROM
46029 IS AROUND 230 DEGREES. SINCE THE EXPECTED SWELL IS 240
DEGREES THIS BUOY IS A GOOD INDICATOR OF WHAT IS TO COME OF THIS
SWELL. A SIMPLE DECAY TOOL SUGGEST THIS SWELL WILL BE 11 TO 13 FT
AT 16 SECONDS AS IT MOVES THROUGH THE NORTHERN OREGON WATERS LATER
THIS MORNING AND AFTERNOON. CONFIDENCE IS HIGHER THAT AT LEAST THE
SOUTHERN WATERS...SOUTH OF CASCADE HEAD...WILL HAVE SMALL CRAFT
SEAS...AND HAVE ISSUED AN ADVISORY. BUOY 46050 THE PAST COUPLE OF
HOURS HAS BEEN SHOWING INCREASING HEIGHTS WHICH IS ANOTHER
INDICATOR THAT THE WELL IS ON THE WAY. HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM PST EARLY THIS
MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
CASCADE HEAD OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 AM THIS MORNING
TO 10 PM PST THIS EVENING FOR COASTAL WATERS FROM CASCADE HEAD
OR TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM NOON
TODAY TO 4 PM PST THIS AFTERNOON.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 AM TO
6 AM PST THURSDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1000 PM EST THU FEB 27 2014
.SYNOPSIS...
ARCTIC AIR WILL SPREAD OVER PENNSYLVANIA TONIGHT WITH BITTERLY
COLD WIND CHILLS IN STORE. SOME MODERATION IN TEMPERATURES IS
EXPECTED ON SATURDAY AS HIGH PRESSURE MOVES EAST OF THE
REGION. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SATURDAY
NIGHT AND PRODUCE LIGHT SNOW. A WIDE-REACHING STORM SYSTEM WILL
THEN MOVE IN QUICKLY FROM THE OHIO AND TENNESSEE VALLEYS. THE
STORM WILL SLIDE ALONG THE OLD FRONT WHICH WILL BE LAID OUT TO OUR
SOUTH. IT WILL MAKE AN IMPACT ON ALL OF PA LATE SUNDAY THROUGH ALL
OF MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS THE
REGION SUNDAY INTO MONDAY. FAIR AND CONTINUED COLD WEATHER WILL
FOLLOW FOR THE REST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
10 AM UPDATE...
WINDS ARE SLACKENING AND TEMPS COOLING AS ANTICIPATED. WIND CHILL
ADVY LOOKING ON TRACK. SKIES HAVE CLEARED OTHER THAN A COUPLE OF
CLOUDS ACROSS THE NRN TIER WHICH AREA TOUGH TO PICK UP ON IR
CHANNELS - EVEN THE 11-3.9 MICRON IMAGERY - SINCE GROUND/SNOW
COVER IS JUST AS COLD AS THE CLOUDS.
7 PM UPDATE...
MINOR TWEAKS TO NEAR TERM TEMPS/WINDS. WIND CHILLS ARE CLOSE TO
WARNING FOR THE NC MTS. TEMPS AT THE CLOSEST NY SITES AND BFD ARE
ALL ALREADY 0F. MAY END UP PUTTING WARNING UP FOR A FEW COS
THERE...BUT MESO MDLS STILL TRY TO SLACKEN THE WINDS ENOUGH TO
KEEP THEM JUST ABOVE -25.
PREV...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG
A SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MOST OF THE SNOW IS OVER NOW...BUT SOME SNOW SHOWERS WILL LINGER
AT BFD AND JST OVERNIGHT.
WINDS VERY GUSTY STILL...WILL LINGER FOR SEVERAL MORE HOURS.
EXPECT A DECENT DAY ON FRIDAY...WITH LOTS OF SUN...AS HIGH
PRESSURE BUILDS INTO THE AREA. WINDS WILL BE LIGHTER. THE
BIG ISSUE WILL BE VERY LOW TEMPS FOR LATE FEB.
FRONT STALLS NEARBY LATER THIS WEEKEND. MIXED PRECIPITATION
LIKELY LATER IN THE WEEKEND INTO MONDAY...AS AT LEAST ONE
WEAK LOW LIFTS NE ALONG THE FRONT.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
714 PM EST THU FEB 27 2014
.SYNOPSIS...
ARCTIC AIR WILL SPREAD OVER PENNSYLVANIA TONIGHT WITH BITTERLY
COLD WIND CHILLS IN STORE. SOME MODERATION IN TEMPERATURES IS
EXPECTED ON SATURDAY AS HIGH PRESSURE MOVES EAST OF THE
REGION...AND A FRONT LIFTS NORTHWARD. THE FRONT WILL WAGGLE SOUTH
AGAIN ON SUNDAY AS A STORM SYSTEM APPROACHES FROM THE OHIO VALLEY.
THE STORM WILL IMPACT ALL OF PA LATE SUNDAY THROUGH ALL OF MONDAY.
SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS THE REGION
SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND CONTINUED COLD WEATHER
FOR THE REST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
7 PM UPDATE...
MINOR TWEAKS TO NEAR TERM TEMPS/WINDS. WIND CHILLS ARE CLOSE TO
WARNING FOR THE NC MTS. TEMPS AT THE CLOSEST NY SITES AND BFD ARE
ALL ALREADY 0F. MAY END UP PUTTING WARNING UP FOR A FEW COS
THERE...BUT MESO MDLS STILL TRY TO SLACKEN THE WINDS ENOUGH TO
KEEP THEM JUST ABOVE -25.
PREV...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG
A SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MOST OF THE SNOW IS OVER NOW...BUT SOME SNOW SHOWERS WILL LINGER
AT BFD AND JST OVERNIGHT.
WINDS VERY GUSTY STILL...WILL LINGER FOR SEVERAL MORE HOURS.
EXPECT A DECENT DAY ON FRIDAY...WITH LOTS OF SUN...AS HIGH
PRESSURE BUILDS INTO THE AREA. WINDS WILL BE LIGHTER. THE
BIG ISSUE WILL BE VERY LOW TEMPS FOR LATE FEB.
FRONT STALLS NEARBY LATER THIS WEEKEND. MIXED PRECIPITATION
LIKELY LATER IN THE WEEKEND INTO MONDAY...AS AT LEAST ONE
WEAK LOW LIFTS NE ALONG THE FRONT.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
644 PM EST THU FEB 27 2014
.SYNOPSIS...
A REINFORCING THE ARCTIC AIR MASS WILL SPREAD OVER PENNSYLVANIA
TONIGHT WITH BITTERLY COLD WIND CHILLS OVER MUCH OF CENTRAL PA
THROUGH FRIDAY MORNING. SOME MODERATION IS EXPECTED ON SATURDAY
AS HIGH PRESSURE MOVES EAST OF THE REGION...AND THE FRONT LIFTS
NORTHWARD. IT WILL WAGGLE SOUTH AGAIN ON SUNDAY AHEAD OF A
MOIST SOUTHERN STREAM STORM SYSTEM THAT IS EXPECTED TO MOVE SOUTH
OF PA ON MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED
ACROSS THE REGION SUNDAY INTO MONDAY...FOLLOWED BY FAIR AND
CONTINUED COLD WEATHER FOR TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG
A SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MOST OF THE SNOW IS OVER NOW...BUT SOME SNOW SHOWERS WILL LINGER
AT BFD AND JST OVERNIGHT.
WINDS VERY GUSTY STILL...WILL LINGER FOR SEVERAL MORE HOURS.
EXPECT A DECENT DAY ON FRIDAY...WITH LOTS OF SUN...AS HIGH
PRESSURE BUILDS INTO THE AREA. WINDS WILL BE LIGHTER. THE
BIG ISSUE WILL BE VERY LOW TEMPS FOR LATE FEB.
FRONT STALLS NEARBY LATER THIS WEEKEND. MIXED PRECIPITATION
LIKELY LATER IN THE WEEKEND INTO MONDAY...AS AT LEAST ONE
WEAK LOW LIFTS NE ALONG THE FRONT.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1256 PM EST WED FEB 26 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER
CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE
NORTH ON FRIDAY AND LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST WEDNESDAY...FORECAST REMAINS ON TRACK AS SHOWER
ACTIVITY CONTINUES TO EXIT TO THE SOUTHEAST. THUS...ASIDE FROM
ADJUSTING TEMPERATURES AND DEWPOINTS TO REFLECT LATEST OBSERVATIONAL
TRENDS...NO OTHER CHANGES WERE MADE WITH THIS UPDATE. LOW RH AND
INCREASING WINDS CONTINUE TO PRESENT MODEST FIRE WX CONCERNS
TOMORROW...ESPECIALLY IN THE HIGH TERRAIN OF NC. PLEASE REFER TO
FIRE WX SECTION OF AFD FOR DETAILS.
PREVIOUS DISCUSSION...
AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH
THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH
COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS
PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED
LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL
CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC.
MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE
WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP
DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR
TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z
TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF
MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC
POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA
IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS
TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT
SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND
MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF
RADAR RETURNS OVER EAST TN.
CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS
EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN.
GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE
AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE
WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL
EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE
30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS
DROP INTO THE TEENS MTNS AND 20S PIEDMONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION
DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH
BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE
POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE
FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS.
OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER
THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE
LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW
NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE
SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON
THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL
CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE
PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION
OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE
ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE
MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE
WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO
SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND
THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE
LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID
LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD
SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS
OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN
PLAN TO MENTION IT IN THE HWO ATTM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z
ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE
ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE
CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER
EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF
THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS
BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS
THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS
INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE
CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU
DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO
BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF
SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM
FARTHER SOUTH COMPARED TO THE ECMWF.
AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A
COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF
THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER
BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY
ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND
MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT
24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS
KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE
OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND
OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING
WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON
TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY
HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE
NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE
LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY
THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AS COLD AIR
ADVECTION PREVAILS AND HIGH PRESSURE BUILDS. BKN MID/HIGH LEVEL
CIRRUS WILL PERSIST THROUGH THE AFTERNOON AMIDST NE WINDS AROUND
6-8KTS. A SECOND MID LEVEL WAVE WILL DIVE ACROSS THE REGION
OVERNIGHT LEADING DEVELOPMENT OF A WEAK LOW LEVEL TROF. INCREASING
SATURATION ALONG THIS BOUNDARY WILL LEAD TO DEVELOPMENT OF LOW VFR
CIGS THROUGH APPROXIMATELY 08Z BEFORE SCATTERING OUT. SKIES WILL
CLEAR BY MID/LATE MORNING LEADING TO FAIR WEATHER FOR THURSDAY. AS
FOR WINDS...EXPECTING FLOW TO BACK NORTHWESTERLY AS THE ABOVE
MENTIONED WAVE AND ASSOCIATED WEAK SURFACE BOUNDARY PASS THROUGH THE
REGION BY AROUND 15Z THURSDAY MORNING.
ELSEWHERE...MUCH THE SAME AS KCLT ABOVE AS VFR CONDITIONS WILL
PREVAIL THROUGH THE PERIOD. BKN MID/HIGH LEVEL CIRRUS WILL PERSIST
THROUGH THE AFTERNOON AT ALL SITES EXCEPT FOR KAVL WHERE SKIES SCT
OUT. OTHERWISE...LOW VFR CIGS ARE POSSIBLE AT KGSP/KGMU ASSOCIATED
WITH THE ABOVE MENTIONED 850 TROF AXIS OVERNIGHT. ALL OTHER SITES
WILL REMAIN SCT/FEW AROUND 6KFT. LIGHT WINDS WILL BACK
NORTHWESTERLY THURSDAY MORNING AT ALL SITES BEHIND THE PASSAGE OF
THE APPROACHING WEAK SFC BOUNDARY...WITH THE EXCEPTION OF KAVL WHICH
REMAINS NORTHWESTERLY THROUGH THE PERIOD. WINDS WILL INCREASE
ACROSS THE REGION TO AROUND THE 8-10KTS RANGE LATE THURSDAY MORNING
AT ALL SITES EXCEPT KAVL WHERE SUSTAINED FLOW AROUND THE 12KT RANGE
WITH 20-25KT GUSTS IS EXPECTED.
OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED
RESTRICTIONS ARE POSSIBLE EARLY SAT.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
THERE IS LITTLE CHANGE IN THINKING FROM THE PREVIOUS FORECAST CYCLE.
THE PLANNING FORECAST HAS BEEN UPDATED THROUGH TOMORROW BASED UPON
THE LATEST FORECAST DATA...PRIMARILY FOR MINOR CHANGES IN SMOKE
MANAGEMENT PARAMETERS. RH HAS ALSO BEEN LOWERED SLIGHTLY FOR THIS
AFTERNOON...BUT MIN RH OF 25 PERCENT OR LESS IS EXPECTED TO BE
LOCALIZED AND BRIEF...WHILE WINDS SHOULD GRADUALLY DIMINISH THROUGH
THE AFTERNOON.
AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS EXPECTED TO FALL
BELOW 20 PERCENT IN MOST AREAS DURING THE AFTERNOON. IN ADDITION...
W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF ANOTHER DRY COLD FRONT
DURING THE AFTERNOON. WINDS MAY GUST AS HIGH AS 30 MPH IN THE
MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT. CRITICAL WIND AND RH
MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS AND NC FOOTHILLS THU
AFTERNOON.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...CDG/WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...CDG
FIRE WEATHER...LANE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1003 AM EST WED FEB 26 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER
CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE
NORTH ON FRIDAY AND LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM EST WEDNESDAY...LATEST RADAR IMAGERY CONTINUES TO
INDICATE SHOWER ACTIVITY SOUTH OF INTERSTATE 85 ASSOCIATED WITH
EARLIER WEAK FRONTAL BOUNDARY PASSAGE. MOST RECENT HIGHRES NEAR
TERM GUIDANCE SOLUTIONS YIELD DECREASING COVERAGE OVER THE NEXT 2-3
HOURS FOR THESE ZONES. ADDITIONALLY...CONFIDENCE CONTINUES TO
DECREASE ON ANY SNOW SHOWER ACTIVITY ALONG THE HIGH TERRAIN OF NC
ASSOCIATED WITH WEAK NORTHWEST FLOW THEREFORE DECIDED TO LOWER POPS
FURTHER WITH ALL MENTIONABLE POPS REMOVED BY 16Z ALONG THE TN
BORDER. OTHERWISE...FORECAST REMAINS ON TRACK AND ASIDE FROM TWEAKS
TO TEMPERATURES AND DEWPOINTS...NO OTHER SIGNIFICANT CHANGES MADE.
LOW RH AND INCREASING WINDS CONTINUE TO PRESENT MODEST FIRE WX
CONCERNS TOMORROW...ESPECIALLY IN THE HIGH TERRAIN OF NC. PLEASE
REFER TO FIRE WX SECTION OF AFD FOR DETAILS.
PREVIOUS DISCUSSION...
AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH
THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH
COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS
PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED
LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL
CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC.
MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE
WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP
DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR
TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z
TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF
MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC
POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA
IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS
TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT
SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND
MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF
RADAR RETURNS OVER EAST TN.
CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS
EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN.
GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE
AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE
WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL
EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE
30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS
DROP INTO THE TEENS MTNS AND 20S PIEDMONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION
DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH
BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE
POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE
FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS.
OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER
THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE
LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW
NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE
SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON
THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL
CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE
PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION
OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE
ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE
MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE
WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO
SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND
THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE
LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID
LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD
SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS
OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN
PLAN TO MENTION IT IN THE HWO ATTM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z
ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE
ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE
CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER
EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF
THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS
BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS
THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS
INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE
CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU
DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO
BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF
SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM
FARTHER SOUTH COMPARED TO THE ECMWF.
AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A
COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF
THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER
BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY
ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND
MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT
24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS
KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE
OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND
OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING
WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON
TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY
HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE
NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE
LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY
THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LOW VFR CLOUDINESS LINGERS THIS MRNG IN WARM UPGLIDE PRIOR
TO ARRIVAL OF COLD FRONT. PRECIP CHANCES DUE TO THE UPGLIDE ARE
LOW...WITH SHORT TERM GUID KEEPING MOST OF THE RESPONSE WELL SOUTH.
A FEW SPRINKLES OR BRIEF -SHRA ARE POSSIBLE THRU MID MRNG...BUT
WITHOUT RESTRICTIONS. MAINLY NE WINDS PRIOR TO THE FROPA...POSSIBLY
KEPT CLOSER TO 090 DUE TO LEE TROUGHING. NW WINDS AND CLEARING SKIES
BY MIDDAY POST FROPA. SKC LIKELY OVERNIGHT...BUT NAM/GFS BOTH TRY TO
DEVELOP SOME SPOTTY LOW VFR CLOUDS DUE TO LLVL CONVERGENCE IN THE
LEE OF THE MTNS. THIS IS A BIT UNUSUAL AND IS NOT BACKED UP BY MOS
SO WILL NOT REFLECT IN TAF.
ELSEWHERE...PRECIP CHANCES THIS AM ARE TOO LOW TO MENTION EXCEPT AT
KAND...WHICH WILL BE NEARER THE BEST LIFT/MSTR ASSOCIATED WITH WARM
ADVECTION OVER THE DEEP SOUTH. CIGS LIKELY TO STAY LOW VFR AT
WORST...BUT WILL MONITOR UPSTREAM OBS FOR LOWER CIGS WHICH MIGHT BE
ASSOCIATED WITH PRECIP. NW FLOW INTO THE MTNS WILL PRODUCE A FEW
-SHSN BUT THESE SHOULD BE VERY LIGHT AND MAY NOT CAUSE SGFNT
REDUCTION IN VSBY. EXCEPT AT KAVL WHICH REMAINS NW...NELY WINDS WILL
PREVAIL UNTIL THE FRONT PASSES AND SKIES GRADUALLY CLEAR. POST FROPA
WINDS WILL MAINLY BE NW BEFORE VEERING TONIGHT.
OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED
RESTRICTIONS ARE POSSIBLE EARLY SAT.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
LAND MANAGEMENT PARTNERS SHOULD EXPECT COORDINATION THIS
AFTERNOON FOR POSSIBLE FIRE WEATHER WATCH OR FIRE DANGER
STATEMENTS FOR THURSDAY.
THERE IS LITTLE CHANGE IN THINKING FROM THE PREVIOUS FORECAST
CYCLE. THE PLANNING FORECAST HAS BEEN UPDATED THROUGH TOMORROW
BASED UPON THE LATEST FORECAST DATA...PRIMARILY FOR MINOR CHANGES
IN SMOKE MANAGEMENT PARAMETERS. RH HAS ALSO BEEN LOWERED SLIGHTLY
FOR THIS AFTERNOON...BUT MIN RH OF 25 PERCENT OR LESS IS EXPECTED
TO BE LOCALIZED AND BRIEF...WHILE WINDS SHOULD GRADUALLY DIMINISH
THROUGH THE AFTERNOON.
AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS EXPECTED TO FALL
BELOW 20 PERCENT IN MOST AREAS DURING THE AFTERNOON. IN ADDITION...
W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF ANOTHER DRY COLD FRONT
DURING THE AFTERNOON. WINDS MAY GUST AS HIGH AS 30 MPH IN THE
MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT. CRITICAL WIND AND RH
MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS AND NC FOOTHILLS THU
AFTERNOON.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...LANE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
627 AM EST WED FEB 26 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS MORNING AND USHER IN COOLER
CANADIAN HIGH PRESSURE. THIS HIGH WILL BECOME REINFORCED FROM THE
NORTH ON FRIDAY AND LINGER INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 AM EST...SHORTWAVE ROTATES THRU THE ERN CONUS UPPER TROUGH
THIS MORNING...WITH COLD FRONT USHERING IN HIGH PRESSURE AND A MUCH
COLDER AIRMASS OVER THE COURSE OF THE DAY. WESTERLY MIDLEVEL WINDS
PRIOR TO THE FRONT WILL PROVIDE SLIGHT WARM ADVECTION AND ASSOCIATED
LIFT...BUT MODELS SEEM TO RESPOND MORE TO INTERACTION OF FRONTAL
CONVERGENCE WITH INCUMBENT MOISTURE ACRS GA/SC.
MESO MODELS INCLUDING LATEST COUPLE HRRR RUNS CONFINE QPF RESPONSE
WELL SOUTH OF I-85. GFS AND SREF HOWEVER FAVOR MORE OF THE PRECIP
DEVELOPING ACRS THE UPSTATE. THIS IS NOT WELL SUPPORTED BY RADAR
TRENDS SO FAR THIS AM. BEST POPS STILL LOOK TO BE IN 12-15Z
TIMEFRAME AS THE FRONT ENTERS THE LOWER PIEDMONT. DESPITE LACK OF
MODEL RESPONSE...GIVEN THE SETUP IT IS REASONABLE TO INCLUDE SCHC
POPS A BIT FURTHER NORTH...WITH TIGHT THERMAL GRADIENT ACRS THE FA
IN EXIT REGION OF THE SHORTWAVE THRU THE MRNG. NW FLOW STILL LOOKS
TO HAVE SUFFICIENT ORIENTATION AND MOISTURE TO PRODUCE BRIEF LIGHT
SNOW IN THE MTNS...BUT LATEST GUIDANCE SUPPORTS ONLY CHC POPS AND
MINIMAL ACCUMS. IN FACT THIS MAY BE A BIT OPTIMISTIC GIVEN LACK OF
RADAR RETURNS OVER EAST TN.
CLEARING OF THE LOW-MID CLOUDS ASSOCIATED WITH THE FRONTAL ZONE IS
EXPECTED TO RAPIDLY OCCUR THRU MIDDAY LEAVING A MOSTLY SUNNY AFTN.
GIVEN THE COLD AND NEWLY ARRIVED AIR MASS BUT ALSO ABUNDANT SUNSHINE
AND SLIGHT DOWNSLOPING...A BLEND OF MOS AND RAW TEMPS IS APPROPRIATE
WHICH CONTINUES TO SUPPORT TEMPS A COUPLE CATEGORIES BELOW NORMAL
EXCEPT IN THE HIGH TERRAIN WHERE MANY AREAS WON/T RISE OUT OF THE
30S. TONIGHT...WINDS BECOME LIGHT AND SKIES REMAIN CLEAR AND LOWS
DROP INTO THE TEENS MTNS AND 20S PIEDMONT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 200 AM WEDNESDAY...A DRY COLD FRONT WILL CROSS THE REGION
DURING THE DAY ON THURSDAY...LOWERING DEWPOINTS EVEN FURTHER. WITH
BREEZY TO WINDY CONDITIONS OVER THE NC MTNS AND FOOTHILLS...THE
POTENTIAL EXITS FOR CRITICAL FIRE WEATHER CONDITIONS. PLEASE SEE THE
FIRE WEATHER PART OF THE DISCUSSION FOR MORE DETAILS.
OTHERWISE...DRY COLD AIR DAMMING WILL BECOME MORE PRONOUNCED OVER
THE REGION THURSDAY NIGHT AND FRIDAY. THE THICKNESS TROUGH IN THE
LEE SHOULD RESULT IN COLD CONDITIONS THU NIGHT AND WELL BELOW
NORMAL TEMPERATURES ON FRIDAY. THURSDAY WE SHOULD SEE CLEAR...BLUE
SKIES. SKIES REMAIN CLEAR THU NIGHT...BUT HIGH CLOUDS SHOULD BE ON
THE INCREASE DURING THE DAY ON FRIDAY. A FAST MOVING SHORT WAVE WILL
CROSS THE NC ZONES FRI NIGHT. MOST OF THE FORCING WITH THE WAVE
PASSES NORTH OF THE FORECAST AREA. HOWEVER...LLVL WARM ADVECTION
OVER THE WRN PIEDMONT MAY SUPPORT SOME PATCHY LIGHT PCPN OVER THE
ERN ZONES. THERE ALSO APPEARS TO BE SUFFICIENT FORCING ACROSS THE
MTNS TO SUPPORT CHANCE POPS AS WELL. I USED THE BOURGOUIN TECHNIQUE
WHICH STARTS PCPN AS RAIN EARLY FRIDAY NIGHT WITH A TRANSITION TO
SNOW AND THEN FREEZING RAIN OVER MOST OF THE NC ZONES. UNDERSTAND
THAT QPF IS VERY LIGHT WITH THIS EVENT AND POPS ARE GENERALLY IN THE
LOW CHANCE TO SLIGHT CHANCE RANGE. THAT/S TO SAY...THE WEATHER GRID
LOOKS SCARIER THAN THE REALITY OF THE SITUATION. STILL...WE COULD
SEE A LIGHT ACCUMULATION OF SNOW OR ICE NORTH OF I40 AND OVER PARTS
OF THE NC MTNS FRIDAY NIGHT...BUT THE PCPN IS SO LIGHT I DON/T EVEN
PLAN TO MENTION IT IN THE HWO ATTM.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 230 AM EST WEDNESDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z
ON SUNDAY WITH WHATS LEFT OF AN UPPER SHORTWAVE MOVING OUT OVER THE
ATLANTIC AND UPPER RIDGING BUILDING OVER THE GULF OF MEXICO AND SE
CONUS. THE LONG RANGE MODELS ARE TRYING TO CLOSE OFF AN H5 LOW OVER
EXTREME SOUTHERN BRITISH COLUMBIA EARLY SUNDAY WITH THE NEWER RUN OF
THE GFS BEING MORE PRONOUNCED. AS WE MOVE INTO MONDAY...HEIGHTS
BEGIN TO LOWER AGAIN AS A COMPLEX UPPER TROF PATTERN MOVES SE ACROSS
THE FAR NORTHERN PLAINS AND INTO THE GREAT LAKES REGION. THE MODELS
INDICATE THAT THE MAIN TROF AXIS WILL LIKELY BE NORTH OF THE
CAROLINAS BY LATE TUES/EARLY WED AND PERSIST OVER THE REGION THRU
DAY 7. OVERALL...THE LONG RANGE MODELS APPEAR TO BE COMING INTO
BETTER AGREEMENT WRT THE PROGRESSION AND TIMING OF THIS UPPER TROF
SYSTEM...WITH THE GFS BEING MORE AMPLIFIED AND BRINGING THE SYSTEM
FARTHER SOUTH COMPARED TO THE ECMWF.
AT THE SFC...THE HIGH CENTERED OVER NEW ENGLAND HELPING TO PRODUCE A
COLD AIR WEDGE PATTERN OVER THE CAROLINAS WILL BE MOVING WELL OFF
THE COAST BY EARLY SUN. THE MODELS CONTINUE TO MAINTAIN ANOTHER
BERMUDA TYPE HIGH CENTERED TO OUR EAST ON SUN AND EARLY MON. THEY
ALSO SPIN UP A LOW OVER THE SOUTHERN MISS RIVER VALLEY EARLY MON AND
MOVE IT OVER THE CWFA BY MON AFTERNOON. WHAT HAPPENS OVER THE NEXT
24 TO 36HRS VARIES CONSIDERABLY BETWEEN THE GFS AND ECMWF. THE GFS
KEEPS THE LOW AND ITS ASSOCIATED REGION OF BROAD AND DEEP MOISTURE
OVER THE FCST AREA THRU TUES AFTERNOON BEFORE MOVING IT NE AND
OFFSHORE...WHILE THE ECMWF AND CMC MOVE IT OFFSHORE BY MON EVENING
WITH DRIER HIGH PRESSURE SPREADING OVER THE REGION IN ITS WAKE ON
TUES. BOTH MODELS AGREE THAT THE REMAINDER OF THE FCST SHOULD BE DRY
HIGH PRESSURE OVER THE AREA ON WED. TEMPS WILL START OUT WELL ABOVE
NORMAL FOR EARLY MARCH WITH HIGHS ON SUN IN THE MID 60S FOR THE
LOWER ELEVATIONS AND UPPER 50S TO LOW 60S FOR THE HIGHER TERRAIN. BY
THE END OF THE PERIOD...I ANTICIPATE THAT VALUES WILL COOL BACK DOWN
BELOW CLIMATOLOGY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...LOW VFR CLOUDINESS LINGERS THIS MRNG IN WARM UPGLIDE PRIOR
TO ARRIVAL OF COLD FRONT. PRECIP CHANCES DUE TO THE UPGLIDE ARE
LOW...WITH SHORT TERM GUID KEEPING MOST OF THE RESPONSE WELL SOUTH.
A FEW SPRINKLES OR BRIEF -SHRA ARE POSSIBLE THRU MID MRNG...BUT
WITHOUT RESTRICTIONS. MAINLY NE WINDS PRIOR TO THE FROPA...POSSIBLY
KEPT CLOSER TO 090 DUE TO LEE TROUGHING. NW WINDS AND CLEARING SKIES
BY MIDDAY POST FROPA. SKC LIKELY OVERNIGHT...BUT NAM/GFS BOTH TRY TO
DEVELOP SOME SPOTTY LOW VFR CLOUDS DUE TO LLVL CONVERGENCE IN THE
LEE OF THE MTNS. THIS IS A BIT UNUSUAL AND IS NOT BACKED UP BY MOS
SO WILL NOT REFLECT IN TAF.
ELSEWHERE...PRECIP CHANCES THIS AM ARE TOO LOW TO MENTION EXCEPT AT
KAND...WHICH WILL BE NEARER THE BEST LIFT/MSTR ASSOCIATED WITH WARM
ADVECTION OVER THE DEEP SOUTH. CIGS LIKELY TO STAY LOW VFR AT
WORST...BUT WILL MONITOR UPSTREAM OBS FOR LOWER CIGS WHICH MIGHT BE
ASSOCIATED WITH PRECIP. NW FLOW INTO THE MTNS WILL PRODUCE A FEW
-SHSN BUT THESE SHOULD BE VERY LIGHT AND MAY NOT CAUSE SGFNT
REDUCTION IN VSBY. EXCEPT AT KAVL WHICH REMAINS NW...NELY WINDS WILL
PREVAIL UNTIL THE FRONT PASSES AND SKIES GRADUALLY CLEAR. POST FROPA
WINDS WILL MAINLY BE NW BEFORE VEERING TONIGHT.
OUTLOOK...DRY/VFR THU-FRI...BUT PRECIPITATION AND ASSOCIATED
RESTRICTIONS ARE POSSIBLE EARLY SAT.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-11Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.FIRE WEATHER...
A MODIFIED ARCTIC AIR MASS WILL RESULT IN DEWPOINTS IN THE SINGLE
DIGITS AND TEENS THIS AFTERNOON AND AGAIN THU AFTERNOON. WITH A
RELATIVELY COOL AIR MASS IN PLACE...RH IS EXPECTED TO DIP TO 25
PERCENT OR LESS ONLY BRIEFLY TODAY. MEANWHILE...GUSTY MORNING WINDS
SHOULD BEGIN TO DIMINISH BY AFTERNOON. AT THIS TIME...THE GUSTY
WINDS AND LOWEST RH ARE NOT EXPECTED TO OVERLAP TODAY.
HOWEVER...AS THE AIR MASS BEGINS TO WARM ON THURSDAY...RH IS
EXPECTED TO FALL BELOW 20 PERCENT IN MOST AREAS DURING THE
AFTERNOON. IN ADDITION... W/NW WINDS WILL BEGIN TO INCREASE AHEAD OF
ANOTHER DRY COLD FRONT DURING THE AFTERNOON. WINDS MAY GUST AS HIGH
AS 30 MPH IN THE MTNS...AND TO AROUND 20 MPH IN THE PIEDMONT.
CRITICAL WIND AND RH MAY OVERLAP FOR SEVERAL HOURS ACROSS THE MTNS
AND NC FOOTHILLS THU AFTERNOON.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...MCAVOY
LONG TERM...JPT
AVIATION...WIMBERLEY
FIRE WEATHER...MCAVOY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
536 AM CST WED FEB 26 2014
.DISCUSSION...
SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...
FIRST S/WV IS EXITING THE AREA AND WILL TAKE A BULK OF THE
RAINFALL WITH IT. A SECOND S/WV WILL BE APPROACHING THE AREA LATER
THIS MORNING BUT IT APPEARS THAT MOST OF THE PRECIP WILL TARGET
THE SOUTHERN TAF SITES. STILL SOME UNCERTAINTY WITH REGARD TO
REDEVELOPMENT AS THE RAP/NAM AND ECMWF ARE CONSIDERABLY DRIER THAN
THE GFS. MAINLY MVFR CIGS ARE EXPECTED TODAY WITH PERIODS OF IFR.
VFR CONDS EXPECTED TO DEVELOP OVERNIGHT WITH VFR CONDS EXPECTED ON
THURSDAY. WINDS WILL BE GUSTY THIS MORNING WITH SPEEDS DECREASING
IN THE AFTN AND DECOUPLING TO NEAR CALM OVERNIGHT. 43
&&
.PREV DISCUSSION... /ISSUED 453 AM CST WED FEB 26 2014/
DISCUSSION...
THE RADAR HAS FILLED IN NICELY THIS MORNING WITH SOME ISOLATED
THUNDER NORTH OF INTERSTATE 10. THIS RAINFALL IS THE RESULT OF A
PASSING SURFACE COLD FRONT IN COMBINATION WITH MULTIPLE UPPER
LEVEL DISTURBANCES MOVING ACROSS THE AREA. THE COLD FRONT HAS NOW
MOVED OFFSHORE WITH TEMPERATURES FALLING IN ITS WAKE. A HAND
ANALYSIS AT 250MB FROM 0Z THIS MORNING STILL SHOWS THE SUBTROPICALJET
WITH AN UNFAVORABLE ANTICYCLONIC CURVATURE TO IT. THE JET IS
FORECASTED TO FLATTEN THOUGH AND ALLOW SOUTHEAST TEXAS TO FALL
BRIEFLY INTO A RRQ THIS MORNING INTO EARLY AFTERNOON BEFORE
EXITING THE AREA THIS EVENING.
ANOTHER ROUND OF RAIN HAS STARTED TO FIRE OUT NEAR THE DEL RIO
AREA AND IS ALSO A RESULT OF A PASSING UPPER LEVEL DISTURBANCE.
THE DISTURBANCE IS FORECASTED TO MOVE TO THE EAST DURING THE DAY
TODAY AND BRING SOME MORE RAINFALL TO THE AREA THIS AFTERNOON. GFS
AND NAM OMEGA FIELDS HINT AT THE SOUTHERN HALF OF THE AREA TO BE
THE MOST LIKELY SPOT FOR THE RAINFALL THIS AFTERNOON. THE HRRR AND
TEXAS TECH WRF WOULD ALSO TEND TO AGREE WITH THIS. MODELS ARE ALSO
INDICATING THE POSSIBILITY OF SOME LIGHT STRATIFORM RAIN THROUGH
THE WASHINGTON... MONTGOMERY... SAN JACINTO COUNTY AREA. ONLY
CONCERN WITH THIS SOLUTION IS THAT BOTH GFS AND NAM MODEL
SOUNDINGS SHOW DRY AIR WORKING ITS WAY SOUTH IN THE 850 TO 700MB
LAYER.
TEMPERATURES WILL BE HOLDING STEADY OR DROPPING THROUGH
THE DAY TODAY AS SURFACE HIGH PRESSURE SETTLES OVERHEAD. MODELS
ARE ALSO HINTING AT THE CLOUDS TRYING TO BREAK BY THURSDAY
MORNING. THIS IN COMBINATION WITH LIGHT WINDS WILL MAKE THURSDAY
MORNING COLD. ON FRIDAY A SHORTWAVE WILL MOVE TO THE SOUTHEAST AND
CROSS THE TEXARKANA AREA FRIDAY AFTERNOON. BOTH GFS AND NAM
SOUNDINGS LOOK TO HAVE A SIZABLE CAP IN PLACE AROUND THIS TIME
WHICH WOULD TEND TO INHIBIT THUNDERSTORM DEVELOPMENT. ISOLATED
SHOWERS COULD BE POSSIBLE IN OUR NORTHEASTERN ZONES BUT CHANCES
LOOK LOW AS OF NOW.
AN UPPER LEVEL LOW WILL MOVE INTO SOUTHERN CALIFORNIA SATURDAY
AFTERNOON AND BEGIN TO SHEAR OUT AS IT PROGRESSES EASTWARDS. THE
ECMWF AND CANADIAN REMAIN MORE PROGRESSIVE WITH THE FEATURE WHILE
THE GFS HOLDS THE SHORTWAVE UP A BIT. IF THE GFS IS RIGHT A
SURFACE COLD FRONT WILL ALSO BE HELP UP UNTIL LATE MONDAY MORNING.
THE ECMWF AND CANADIAN FAVOR THE COLD FRONT MAKING IT LATE SUNDAY
EVENING OR EARLY MONDAY MORNING. GFS AND ECMWF SOUNDINGS BOTH
SUPPORT SHOWERS AND THUNDERSTORMS WITH THIS FRONT. FOR NOW HAVE
LEANED TOWARDS THE ECMWF AND CANADIAN SOLUTION. 23
MARINE...
SEA FOG HAS ERODED AS STRONG NORTH WINDS DEVELOP IN THE WAKE OF A
DEPARTING COLD FRONT. A TIGHT PRESSURE GRADIENT WILL PRODUCE STRONG
NORTH WINDS THROUGH THE DAY. WILL MAINTAIN AN SCA FOR ALL WATERS
THROUGH 18Z AND THEN THE GULF WATERS THROUGH 00Z. THE GRADIENT WILL
RELAX TONIGHT AS HIGH PRESSURE NEARS THE NORTHERN GULF COAST. THE
HIGH WILL DRIFT EAST AND ONSHORE WINDS WILL RETURN ON THURSDAY AND
PERSIST THROUGH THE WEEKEND. COULD BE ANOTHER BRIEF EPISODE OF SEA
FOG ON SUNDAY. THE NEXT COLD FRONT WILL CROSS THE COASTAL WATERS
LATE SUNDAY NIGHT OR EARLY MONDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 44 32 57 43 70 / 50 20 10 10 10
HOUSTON (IAH) 49 35 59 44 69 / 50 30 10 10 10
GALVESTON (GLS) 54 41 55 53 66 / 60 40 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH
THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH
LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
453 AM CST WED FEB 26 2014
.DISCUSSION...
THE RADAR HAS FILLED IN NICELY THIS MORNING WITH SOME ISOLATED
THUNDER NORTH OF INTERSTATE 10. THIS RAINFALL IS THE RESULT OF A
PASSING SURFACE COLD FRONT IN COMBINATION WITH MULTIPLE UPPER
LEVEL DISTURBANCES MOVING ACROSS THE AREA. THE COLD FRONT HAS NOW
MOVED OFFSHORE WITH TEMPERATURES FALLING IN ITS WAKE. A HAND
ANALYSIS AT 250MB FROM 0Z THIS MORNING STILL SHOWS THE SUBTOPICAL
JET WITH AN UNFAVORABLE ANTICYCLONIC CURVATURE TO IT. THE JET IS
FORECASTED TO FLATTEN THOUGH AND ALLOW SOUTHEAST TEXAS TO FALL
BRIEFLY INTO A RRQ THIS MORNING INTO EARLY AFTERNOON BEFORE
EXITING THE AREA THIS EVENING.
ANOTHER ROUND OF RAIN HAS STARTED TO FIRE OUT NEAR THE DEL RIO
AREA AND IS ALSO A RESULT OF A PASSING UPPER LEVEL DISTURBANCE.
THE DISTURBANCE IS FORECASTED TO MOVE TO THE EAST DURING THE DAY
TODAY AND BRING SOME MORE RAINFALL TO THE AREA THIS AFTERNOON. GFS
AND NAM OMEGA FIELDS HINT AT THE SOUTHERN HALF OF THE AREA TO BE
THE MOST LIKELY SPOT FOR THE RAINFALL THIS AFTERNOON. THE HRRR AND
TEXAS TECH WRF WOULD ALSO TEND TO AGREE WITH THIS. MODELS ARE ALSO
INDICATING THE POSSIBILITY OF SOME LIGHT STRATIFORM RAIN THROUGH
THE WASHINGTON... MONTGOMERY... SAN JACINTO COUNTY AREA. ONLY
CONCERN WITH THIS SOLUTION IS THAT BOTH GFS AND NAM MODEL
SOUNDINGS SHOW DRY AIR WORKING ITS WAY SOUTH IN THE 850 TO 700MB
LAYER.
TEMPERATURES WILL BE HOLDING STEADY OR DROPPING THROUGH
THE DAY TODAY AS SURFACE HIGH PRESSURE SETTLES OVERHEAD. MODELS
ARE ALSO HINTING AT THE CLOUDS TRYING TO BREAK BY THURSDAY
MORNING. THIS IN COMBINATION WITH LIGHT WINDS WILL MAKE THURSDAY
MORNING COLD. ON FRIDAY A SHORTWAVE WILL MOVE TO THE SOUTHEAST AND
CROSS THE TEXARKANA AREA FRIDAY AFTERNOON. BOTH GFS AND NAM
SOUNDINGS LOOK TO HAVE A SIZABLE CAP IN PLACE AROUND THIS TIME
WHICH WOULD TEND TO INHIBIT THUNDERSTORM DEVELOPMENT. ISOLATED
SHOWERS COULD BE POSSIBLE IN OUR NORTHEASTERN ZONES BUT CHANCES
LOOK LOW AS OF NOW.
AN UPPER LEVEL LOW WILL MOVE INTO SOUTHERN CALIFORNIA SATURDAY
AFTERNOON AND BEGIN TO SHEAR OUT AS IT PROGRESSES EASTWARDS. THE
ECMWF AND CANADIAN REMAIN MORE PROGRESSIVE WITH THE FEATURE WHILE
THE GFS HOLDS THE SHORTWAVE UP A BIT. IF THE GFS IS RIGHT A
SURFACE COLD FRONT WILL ALSO BE HELP UP UNTIL LATE MONDAY MORNING.
THE ECMWF AND CANADIAN FAVOR THE COLD FRONT MAKING IT LATE SUNDAY
EVENING OR EARLY MONDAY MORNING. GFS AND ECMWF SOUNDINGS BOTH
SUPPORT SHOWERS AND THUNDERSTORMS WITH THIS FRONT. FOR NOW HAVE
LEANED TOWARDS THE ECMWF AND CANADIAN SOLUTION. 23
&&
.MARINE...
SEA FOG HAS ERODED AS STRONG NORTH WINDS DEVELOP IN THE WAKE OF A
DEPARTING COLD FRONT. A TIGHT PRESSURE GRADIENT WILL PRODUCE STRONG
NORTH WINDS THROUGH THE DAY. WILL MAINTAIN AN SCA FOR ALL WATERS
THROUGH 18Z AND THEN THE GULF WATERS THROUGH 00Z. THE GRADIENT WILL
RELAX TONIGHT AS HIGH PRESSURE NEARS THE NORTHERN GULF COAST. THE
HIGH WILL DRIFT EAST AND ONSHORE WINDS WILL RETURN ON THURSDAY AND
PERSIST THROUGH THE WEEKEND. COULD BE ANOTHER BRIEF EPISODE OF SEA
FOG ON SUNDAY. THE NEXT COLD FRONT WILL CROSS THE COASTAL WATERS
LATE SUNDAY NIGHT OR EARLY MONDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 44 32 57 43 70 / 50 20 10 10 10
HOUSTON (IAH) 49 35 59 44 69 / 50 30 10 10 10
GALVESTON (GLS) 54 41 55 53 66 / 60 40 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH
THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH
LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1246 AM CST WED FEB 26 2014
.UPDATE...
HAVE ISSUED A DENSE FOG ADVISORY FOR COASTAL COUNTIES. NEW ZONES
OUT SHORTLY. 23
&&
.PREV DISCUSSION... /ISSUED 1147 PM CST TUE FEB 25 2014/
DISCUSSION...
06Z AVIATION DISCUSSION BELOW.
AVIATION...
PREVIOUS 00Z THINKING STILL HOLDS TRUE WITH THIS LATEST SET OF
TAFS. THAT BEING OF PRIMARILY VLIFR TO IFR DECKS WITH PERIODIC
SHOWERS AND STRENGTHENED NORTHERLIES...ANOTHER ROUND OR TWO OF
HIGHER AREAL PRECIPITATION COVERAGE IN THE PREDAWN HOURS AND LATER
WEDNESDAY AFTERNOON FROM THE PASSAGE OF WEAK WESTERLY IMPULSES. IN
BETWEEN THESE SHORTWAVES...A POST-FRONTAL ENVIRONMENT CONDUCIVE
TO THE DEVELOPMENT OF EITHER LIGHT RAIN/DRIZZLE/MIST AT THE TERMINAL
TO PASSING VICINITY SHOWERS WITHIN 10 NM OF MOST REGIONAL HUBS.
JUST KEPT IT RAIN THROUGH TOMORROW EVENING...WITH ANY CONVECTION
REMAINING ELEVATED...PER THE COOLING SURFACE AND WARMER ALOFT
PROFILES BROUGHT ON BY THE LOWER LEVEL COLD AIR ADVECTION. 31
PREV DISCUSSION... /ISSUED 930 PM CST TUE FEB 25 2014/
DISCUSSION...
CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATE IS PLANNED FOR THE
OVERNIGHT HOURS. WILL WAIT FOR ALL OF THE 00Z MODELS TO ARRIVE
BEFORE ANY SIGNIFICANT CHANGES ARE MADE TO OUR RAIN CHANCES...WINDS
AND TEMPERATURES.
COLD FRONT IS SLOWLY WORKING ITS WAY THROUGH SOUTHEAST TEXAS THIS
EVENING...APPROACHING THE I-10 CORRIDOR AT AROUND 9 PM. AREAS OF
RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS
THE AREA...AND MODELS INDICATE THIS SHOULD CONTINUE OVERNIGHT AND
ON INTO TOMORROW MORNING (SOME SPOTS WITH THE HEAVIER STORMS HAVE
ALREADY RECEIVED 1 TO 2 INCHES). TEMPERATURES ARE IN THE LOW TO
MID 50S BEHIND THE FRONT UP NORTH...AND EXPECT THIS COOLER AIR TO
WORK ITS WAY TOWARD THE COAST OVERNIGHT. 42
PREV DISCUSSION... /ISSUED 609 PM CST TUE FEB 25 2014/
DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
AVIATION...
THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING
HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM
AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE.
THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO
-TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE
ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR
REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE
RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL
ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND
OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER
DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING
RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP
MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE
THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN
COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE
TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL
ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE
WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE
ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE
VERSA. 31
PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/
DISCUSSION...
FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN
I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM
(EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO
SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT
IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY
BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE
FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY
AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN
HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME.
PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION
WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE
WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP
THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT
FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN
SHOULD TAPER OFF WED EVENING.
COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH
PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE
4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS
DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG
THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A
CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS.
WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN
PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT
BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO
MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE
WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT
AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR
MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS
1040+MB HIGH DROPS INTO THE PLAINS. 47
MARINE...
SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM
EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER
THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT
AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE
COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND
AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH
THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE
12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY
HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR
THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS
INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER
PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO
DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP
BY LATE THIS WEEK AS ONSHORE REDEVELOPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 33 57 42 70 / 60 20 10 10 10
HOUSTON (IAH) 49 36 59 43 69 / 70 30 10 10 10
GALVESTON (GLS) 54 42 55 53 66 / 60 40 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 4 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: BRAZORIA...CHAMBERS...GALVESTON...
MATAGORDA.
GM...DENSE FOG ADVISORY UNTIL 4 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO NOON CST TODAY
FOR THE FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM NOON CST TODAY THROUGH
THIS AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM CST THIS
EVENING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM THIS EVENING THROUGH
LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
HIGH ISLAND TO FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION LATE TONIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1147 PM CST TUE FEB 25 2014
.DISCUSSION...
06Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
PREVIOUS 00Z THINKING STILL HOLDS TRUE WITH THIS LATEST SET OF
TAFS. THAT BEING OF PRIMARILY VLIFR TO IFR DECKS WITH PERIODIC
SHOWERS AND STRENGTHENED NORTHERLIES...ANOTHER ROUND OR TWO OF
HIGHER AREAL PRECIPITATION COVERAGE IN THE PREDAWN HOURS AND LATER
WEDNESDAY AFTERNOON FROM THE PASSAGE OF WEAK WESTERLY IMPULSES. IN
BETWEEN THESE SHORTWAVES...A POST-FRONTAL ENVIRONMENT CONDUCIVE
TO THE DEVELOPMENT OF EITHER LIGHT RAIN/DRIZZLE/MIST AT THE TERMINAL
TO PASSING VICINITY SHOWERS WITHIN 10 NM OF MOST REGIONAL HUBS.
JUST KEPT IT RAIN THROUGH TOMORROW EVENING...WITH ANY CONVECTION
REMAINING ELEVATED...PER THE COOLING SURFACE AND WARMER ALOFT
PROFILES BROUGHT ON BY THE LOWER LEVEL COLD AIR ADVECTION. 31
&&
.PREV DISCUSSION... /ISSUED 930 PM CST TUE FEB 25 2014/
DISCUSSION...
CURRENT FORECAST IS IN GOOD SHAPE. NO UPDATE IS PLANNED FOR THE
OVERNIGHT HOURS. WILL WAIT FOR ALL OF THE 00Z MODELS TO ARRIVE
BEFORE ANY SIGNIFICANT CHANGES ARE MADE TO OUR RAIN CHANCES...WINDS
AND TEMPERATURES.
COLD FRONT IS SLOWLY WORKING ITS WAY THROUGH SOUTHEAST TEXAS THIS
EVENING...APPROACHING THE I-10 CORRIDOR AT AROUND 9 PM. AREAS OF
RAIN WITH EMBEDDED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS
THE AREA...AND MODELS INDICATE THIS SHOULD CONTINUE OVERNIGHT AND
ON INTO TOMORROW MORNING (SOME SPOTS WITH THE HEAVIER STORMS HAVE
ALREADY RECEIVED 1 TO 2 INCHES). TEMPERATURES ARE IN THE LOW TO
MID 50S BEHIND THE FRONT UP NORTH...AND EXPECT THIS COOLER AIR TO
WORK ITS WAY TOWARD THE COAST OVERNIGHT. 42
&&
PREV DISCUSSION... /ISSUED 609 PM CST TUE FEB 25 2014/
DISCUSSION...
00Z AVIATION DISCUSSION BELOW.
AVIATION...
THE SHORT TERM FORECAST...OR THROUGH THE EARLY WEDNESDAY MORNING
HOURS...WILL BE FOR INTERMITTENT SHOWERS WITH A ISOLATED STORM
AND STRENGTHENED NORTH WIND BEHIND AN EVENING COLD FRONTAL PASSAGE.
THE MAIN IMPULSE DRIVING THIS ONGOING WIDELY SCATTERED -SHRA (ISO
-TSRA) IS TRAVELING ACROSS NORTHERN TEXAS THIS EVENING WITH THE
ONLY TRIGGERS LEFT OVER IN THIS HIGHLY-MOIST ENVIRONMENT FOR
REPEAT PRECIPITATION BEING ANOTHER EASTERN PASSING SHORTWAVE
RIPPLE WITHIN THE WESTERLY FLOW AND/OR THE ENHANCED POST-FRONTAL
ISENTROPIC UPGLIDE AS SOUTHWESTERLY MID-UPPER FLOW RIDES UP AND
OVER A PUMPED UP NORTH-NORTHEAST LOWER LEVEL WIND. BETTER UPPER
DIFFULENCE BY TOMORROW AFTERNOON AS SE TX FALLS UNDER AN EXITING
RRQ JET. CONSIDERING THE ABOVE ELEMENTS AND...EVEN WITH NWP
MODELING NOT PROVIDING MUCH GUIDANCE UP TO NOW...STILL BELIEVE
THAT ALL WILL COME IN-LINE FOR BETTER OVERALL (LIGHT) RAIN
COVERAGE. PROBABLY NOT AN ALL-DAY RAIN EVENT...BUT GT 50% OF THE
TIME THERE WILL BE THAT PASSING SHOWER...BRIEF MODERATE RAINFALL
ASSOCIATED WITH STRONGER CELLS WEDNESDAY AFTERNOON...BUT THERE
WILL ALSO BE LONGER PERIODS OF A JUST A LIGHT MIST AND/OR DRIZZLE
ALONG WITH THOSE PESKY FLUCTUATING DECKS FROM IFR TO MVFR AND VICE
VERSA. 31
PREV DISCUSSION... /ISSUED 333 PM CST TUE FEB 25 2014/
DISCUSSION...
FRONT IS NOW PUSHING INTO NRN PORTIONS OF SE TX. SHOULD BE BETWEEN
I-10 AND THE COAST AROUND MIDNIGHT AND OFF THE BEACHES BY 4AM
(EFFECTIVELY ENDING SEA FOG ISSUES FOR A FEW DAYS). STARTING TO
SEE SOME SCT PRECIP DEVELOP ACROSS S PARTS OF THE AREA AND EXPECT
IT TO GRADUALLY INCREASE IN COVERAGE AHEAD OF, AND ESPECIALLY
BEHIND, THE FRONT. HRRR MODEL AND TO A DEGREE NAM12 HAS DONE
FAIRLY WELL WITH RAINFALL DEPICTION (OR LACK THEREOF) SO FAR TODAY
AND SHORT TERM FCST WAS TRENDED THAT WAY. GFS/ECMWF HAVE BEEN
HORRIBLY OVERDONE BOTH IN COVERAGE & AMOUNTS UP TO THIS TIME.
PERIODS OF PRECIP WILL LIKELY CONTINUE THRU WED IN ASSOCIATION
WITH H85 FRONT AND UPPER IMPULSES RIDING FURTHER OVERHEAD IN THE
WRLY FLOW ALOFT. CONSIDERING STRONG CAA...CLOUDINESS AND PRECIP
THE HIGHS FOR THE 24 HOUR PERIOD WILL OCCUR AROUND MIDNIGHT
FOLLOWED BY FALLING AND/OR STEADY TEMPS IN THE 40S WED. RAIN
SHOULD TAPER OFF WED EVENING.
COOL WX CONTINUES THURS BUT ONSHORE WIND WILL BE RESUMING AS HIGH
PRES MOVES EAST AND NEXT SHORTWAVE STARTS DIGGING SEWD DOWN THE
4-CORNERS AREA. THIS DISTURBANCE ISN`T AS IMPRESSIVE AS PREVIOUS
DAYS AND DON`T ANTICIPATE MUCH OF AN IMPACT HERE AS IT MOVES ALONG
THE RED RIVER FRIDAY...AS BEST ENERGY WILL BE WELL NORTH AND A
CAP SHOULD BE IN PLACE. FURTHER LOWERED POPS.
WARMING TREND CONTINUES THRU THE WEEKEND WITH ONSHORE FLOW IN
PLACE. APPEARS THAT WE`LL PROBABLY HAVE ANOTHER COASTAL FOG EVENT
BUT LOOKS LIKE MARDI GRAS PARADES SHOULD OTHERWISE BE DRY PRIOR TO
MID TO LATE SUNDAY AFTN. NEXT STORM SYSTEM APPROACHES FROM THE
WEST LATE IN THE WEEKEND AND KEPT 20-40% POPS IN PLACE SUN AFTN/NIGHT
AHEAD OF THE NEXT FRONT THAT`LL BE MOVING THRU SUNDAY NIGHT OR
MONDAY. KNOCKED TEMPS DOWN EARLY NEXT WEEK (MAYBE NOT ENOUGH) AS
1040+MB HIGH DROPS INTO THE PLAINS. 47
MARINE...
SEA FOG WILL CONTINUE OVER THE GULF WATERS THIS AFTERNOON. AM
EXPECTING THE FOG TO REDEVELOP AND BECOME DENSE OVER THE BAYS LATER
THIS AFTERNOON AND EVENING. THE FOG WILL CLEAR OUT BETWEEN MIDNIGHT
AND SUNRISE AS A COLD FRONT PUSHES THROUGH THE BAYS AND OFF THE
COAST. THE MODELS HAVE BEEN FAIRLY CONSISTENT THE PAST FEW DAYS AND
AM FAIRLY CONFIDENT ON THE TIMING. EXPECT THE FRONT TO MOVE THROUGH
THE BAYS BY AROUND 3 AM AND THEN BEYOND 20 NM OFFSHORE BY 4 AM. THE
12Z MODEL RUN AND GUIDANCE FROM THIS MORNING FORECASTED SLIGHTLY
HIGHER WINDS...INDICATING THAT SMALL CRAFT ADVISORIES ARE LIKELY FOR
THE GULF WATERS AND MATAGORDA BAY. WOULD NOT BE SURPRISED IF WINDS
INCREASE TO BETWEEN 20 AND 25 KNOTS FOR AT LEAST MOST OF THE LOWER
PART OF GALVESTON BAY...ALSO. EXPECT THE NORTHEASTERLY WINDS TO
DIMINISH WEDNESDAY NIGHT AND THURSDAY. ANOTHER FOG EVENT MAY DEVELOP
BY LATE THIS WEEK AS ONSHORE REDEVELOPS.
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 43 33 57 42 / 70 60 20 10 10
HOUSTON (IAH) 49 49 36 59 43 / 70 70 30 10 10
GALVESTON (GLS) 54 54 42 55 53 / 70 60 40 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CST WEDNESDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY FROM 6 AM TO NOON CST WEDNESDAY FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT SHOULD EXERCISE CAUTION WEDNESDAY AFTERNOON FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM WEDNESDAY EVENING
THROUGH LATE WEDNESDAY NIGHT FOR THE FOLLOWING ZONES:
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO MIDNIGHT CST
WEDNESDAY NIGHT FOR THE FOLLOWING ZONES: WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION LATE WEDNESDAY NIGHT FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...31
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS SPOKANE WA
546 PM PST Thu Feb 27 2014
.SYNOPSIS...
Southeast Washington and portions of the Idaho Panhandle will have a
a chance of light rain and mountain snow tonight and Friday as an
upper level low this evening. A bigger weather story will be a
powerful arctic front expected to arrive Friday afternoon into
Saturday. The front will deliver unusually cold temperatures for
this time of year as well as brisk winds and cold wind chill values.
Conditions on Saturday will feel more like December than early
March. Much below normal temperatures will likely persist into early
next week.
&&
.DISCUSSION...
Evening update: I increased shower (snow and rain) coverage for
the next several hours across portions of Spokane/C`dA area for a
wet/messy evening commute. Air temperatures are near to just above
freezing across many areas. Road temperatures remain above
freezing away from the central Panhandle, but with the loss of
daytime heating these will be on the decline and any snow fall or
water on roads is apt to freeze. Right now going east of C`dA
toward Fourth of July Pass, road temperatures are already below
freezing and cameras indicate snow accumulating on roads here.
Pockets of freezing rain have been reported over the higher
Palouse, with a warmer layer of air aloft and temperatures near to
just below freezing. However as the atmospheric column cools this
should transition to general snow (or a snow/rain mix). This will
be monitored.
I updated the overnight forecast as well. The main arctic boundary
should begin to shift the primary precipitation threat over the
next several hours, focusing on the Palouse to central Panhandle
south. However with the incoming arctic front and subtle mid-level
wave rounding the upper low, some guidance (the HRRR and GEM)
indicate some snow shower development late tonight into the
overnight across the Cascades through the Upper Columbia Basin
into the Spokane/C`dA area again. /J. Cote`
&&
.AVIATION...
00Z TAFS: A moist boundary layer will result in widespread stratus
and fog across much of the region through Friday morning, except for
possible at KMWH where confidence is lowest. Westerly moist upslope
flow at low levels will result in light snow across much of the
Central ID Panhandle and out into KPUW tonight. Snow will also be
possible for KGEG, KSFF, KCOE and KEAT late tonight into Friday as
an arctic boundary out of Canada pushes into the region. The Arctic
front will increase the northeast winds down the Purcell Trench with
gusts up to 20 to 25 mph possible across the Spokane/Coeur d`Alene
area by Friday afternoon. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 28 32 6 13 5 18 / 50 60 30 20 30 40
Coeur d`Alene 28 30 4 12 4 17 / 60 60 30 20 30 60
Pullman 32 39 15 21 14 23 / 80 60 60 70 40 50
Lewiston 37 45 22 27 21 30 / 90 60 60 70 40 50
Colville 27 31 7 16 4 23 / 20 50 10 10 20 60
Sandpoint 25 26 2 9 1 17 / 60 70 20 20 20 60
Kellogg 27 28 2 11 4 18 / 90 90 50 50 40 60
Moses Lake 32 40 17 22 13 25 / 20 30 30 10 40 40
Wenatchee 32 41 19 22 14 24 / 20 30 30 30 40 50
Omak 30 34 14 21 9 26 / 10 20 10 10 40 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
258 AM PST Wed Feb 26 2014
.SYNOPSIS...
Dry weather is expected today with a little bit of warming for
most locations. The dry lull in the weather will come to an end on
Thursday. With warmer temperatures expected, rain will be the
primary precipitation type. A return of colder weather is
expected Friday night into Saturday with a good chance of snow for
most locations. Meanwhile much colder air will return for the
weekend with Daytime temperatures this weekend with readings in
the teens to middle 20s. Breezy winds will make it feel even
colder especially over portions of the North Idaho Panhandle.
&&
.DISCUSSION...
Today through tonight...Latest satellite images would suggest we
are looking at a fairly quiet day as 500 mb ridge will remain
fixed over the region. The main focus will revolve around
negatively tilted trough axis and warm front currently pushing
through SW Oregon. The main impact this feature will have on our
forecast area today will be a slowly increasing cloud trend from
the southwest. Despite this increasing cloud trend, there really
is little of any threat of precipitation. The main weather story
will thus revolve around the tricky temperature forecast. The
region remains split between a cool and very dry air mass fixed
over the northern 2/3rds of Washington and most of the Idaho
Panhandle. Meanwhile...a warmer and more moisture laden atmosphere
lingers over extreme SE Washington and adjacent portions of the
Idaho Panhandle. These locations...including Lewiston and Pullman
were seeing dewpoints around 30 degrees with similarly mild
temperatures. Meanwhile the remainder of the forecast area was
seeing dewpoint readings in the mid teens to single digits and
cooler temperatures. The main challenge is will this milder air to
our south retake most of the forecast area through the day as the
front moves in from the south. Certainly the models are consistent
on bringing significant warming to the 850-700 mb layer...but will
this translate to the ground. Not confident it will as the surface
pressure gradients will likely keep most of the winds out of the
north to northeast...which isn`t real favorable for significant
warming....despite the warming aloft. If the winds were strong
enough this warming aloft would readily mix to the ground...but
surface wind guidance is generally fairly weak today. We will
hedge our forecasts toward the cooler guidance solutions by
generally keep highs a little warmer than what we experienced
yesterday.
For tonight...the shortwave trough and associated front continue
to drift across the forecast area from the southwest but it
weakens significantly as it does. Whether or not the front will
have enough juice and lifting by the time it moves into our region
is the question. Models are all over the board with this feature
as far as precipitation goes...however most would agree that if
precipitation were to occur the best chances would occur near the
Cascades due the proximity of the offshore trough. This would lead
to the best moisture availability as well as the best upslope flow
and isentropic ascent. If anything does occur it should be
light...with better chances arriving after sunrise Thursday. fx
Thursday through Tuesday: Fairly low confidence in the forecast.
By Thursday the ridge is breaking down with a closed low moving
into Southern Oregon. This will bring an increased chance of
precipitation across southern WA and central ID on Thursday.
Meanwhile an arctic front will be nearing north ID. By Friday it
will be the convergence of two systems. The moist system from the
south colliding with the arctic air from Canada. Models are differing
on precipitation location and amounts, and it could vary greatly
depending on where they converge. Have increased chance of precip
across southeastern WA and the southern ID Panhandle for now, but
higher chances of precip may need to be brought further north. Snow
levels will lower through the day. Looks like the northern zones
will start and remain as snow, and the southern zones starting out
with snow levels btwn 3-4k ft and then lowering down to near the
valley floors by late afternoon/early evening. Lets not forget the
winds either. By Friday afternoon we get a very strong northeast to
southwest gradient which will create breezy to windy northeast winds
for the Purcell Trench, the Spokane/COE area, and down into portions
of the Palouse and Columbia Basin through at least early Sunday
morning. This arctic front is quite different from "normal" dry
arctic intrusions we see. This one will have lots of moisture around
to keep at least a slight chance of snow in the forecast through the
weekend. Have lowered temperatures as well, but not going as cold as
we could possibly see because am expecting more cloud cover than
what we would normally see. The cold air will remain over the area
through Monday, though it will have moderated a bit by Monday.
Monday into Tuesday we get a broad ridge building into the area with
warmer temperatures inching towards us. There doesn`t seem to be
anything to really scour out the cold temps however so keep
temperatures well below average for this time of the year. /Nisbet
&&
.AVIATION...
12Z TAFS: Low clouds with MVFR cigs will likely persist through at
least through 19z and perhaps longer for PUW and LWS. Satellite
imagery shows clouds actually expanding which suggests they may last
longer than previously anticipated despite the light downslope east
winds. The latest HRRR clears the clouds after 19z...but this is a
typical diurnal trend the model has and typically does not handle
low level moisture all that well. We went with a clearing trend a
little later than model suggests but confidence is not high. The
other question is will these MVFR cigs make their way north to GEG
SFF and COE. Low level gradients out of the NE suggest they will
remain south of the airports...but this needs to be watched as the
cloud deck slowly expands into the wind. Other than these
issues...look for cloudy skies and slowly lowering cigs at all sites
through fcst period. Condtions will generally remain VFR though. fx
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 35 25 39 29 34 10 / 0 10 20 30 50 30
Coeur d`Alene 35 27 40 27 32 10 / 0 10 20 30 50 30
Pullman 40 32 42 33 39 17 / 0 10 40 50 60 50
Lewiston 46 35 47 37 46 27 / 10 20 50 60 50 50
Colville 39 25 42 29 39 15 / 0 10 10 20 30 20
Sandpoint 36 23 40 25 31 11 / 0 0 10 30 50 20
Kellogg 38 28 39 28 31 8 / 0 20 40 60 70 50
Moses Lake 41 28 45 33 43 23 / 0 10 20 30 30 20
Wenatchee 37 28 44 33 41 25 / 10 10 20 20 40 30
Omak 36 22 40 30 39 21 / 0 0 10 20 30 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
900 PM CST THU FEB 27 2014
.UPDATE...
WINDS SHOULD REMAIN LIGHT ENOUGH SO NO WIND CHILL ADVISORY FOR THE
MORNING HOURS.
&&
.AVIATION/06Z TAFS/...
VFR MOSTLY CLEAR SKIES EXPECTED. WILL START TO SEE SOME MID
CLOUDS RETURN FRIDAY MORNING. ANY SNOW WITH NEXT SYSTEM EXPECTED
TO HOLD OFF UNTIL FRIDAY EVENING. EXPECT MVFR CIGS/VSBYS TO
INCREASE ACROSS SRN WI DURING FRIDAY EVENING.
&&
MARINE...
LIGHT WINDS TONIGHT. HIGH SHIFTS EAST AND SSE FLOW
DEVELOPS BETWEEN THE DEPARTING HIGH AND APPROACHING LOW. SMALL
CRAFT FOR GUSTY SSE WINDS FROM LATE MORNING THROUGH LATE
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 330 PM CST THU FEB 27 2014/
TONIGHT - CONFIDENCE...MEDIUM
MAIN CONCERN IS EXTENT OF TEMP DROPOFF BEFORE CLOUDS INCREASE LATER
IN THE NIGHT. VERY DRY AIRMASS IS SETTLING ACROSS SRN WI. DEW POINTS
INTO THE MINUS TEENS. 2 METER TEMPS...ESP THE GFS...HAVE REALLY
BACKED OFF ON THE LOWS. MEANWHILE THE RAP WITH A STRONG INVERSION IS
A LOW OF -31 AT KMSN. MEANWHILE THE NAM SHOWS MORE OF AN ISOTHERMAL
SETUP WITH WARMER LOWS. DROPPED LOWS A BIT MORE THAN PRIOR FORECAST
ESPECIALLY IN WESTERN CWA DUE TO THE VERY LOW DEWPOINTS AND IDEAL
RADIATIONAL SETUP WITH LIGHT WIND/CLEAR SKY REGIME FOR MUCH OF THE
NIGHT WITH THE PROXIMITY OF SURFACE HIGH. WAA CLOUDS INCREASE LATER
IN THE NIGHT...BUT THESE CLOUDS ARE STILL A LONG WAYS OFF IN SD/NEB.
EXPECT THE INITIAL SOUTHERLY RETURN 925 FLOW LATER TONIGHT TO NOT
MIX DOWN TO WARRANT WIND CHILL HEADLINE CONCERNS...ESP WITH ANY
MIXING LIKELY TO COINCIDE WITH THE CLOUD INCREASE AND SUBSEQUENT SFC
TEMP MODIFICATION. SO CONFIDENCE IN WIND CHILL CRITERIA BEING MET
FOR ANY LENGTH OF TIME IN THE WESTERN CWA IS QUITE LOW AT THIS TIME.
FRIDAY - CONFIDENCE...MEDIUM
HIGH SHIFTS EAST AND 850/925 WAA WILL BE WELL UNDERWAY AHEAD OF NEXT
SYSTEM. FORCING MECHANISMS ARE QUESTIONABLE. VERY LITTLE IN THE WAY
OF VORTICITY TO LATCH ONTO...FLOW BECOMES MORE WESTERLY. UPPER JET
DYNAMICS ARE FAIRLY WEAK. THERE IS A HINT OF LOWER LEVEL
FRONTOGENESIS AND WEAK TO MODERATE ISENTROPIC ASCENT WITH INCREASING
SATURATION IN THE NORTHWEST CWA AS THE AFTERNOON WEARS ON. SO WILL
KEY HIGHEST POPS THERE.
FRIDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
WEAKENING MID-LEVEL SHORT WAVE AND LOW LEVEL WARM AIR ADVECTION
SHOULD RESULT IN A PERIOD OF -SN OVER MOST OF THE AREA FRIDAY NIGHT.
SYSTEM WILL BE WEAKENING AS IT MOVES THROUGH BUT ENOUGH COLUMN
MOISTURE AND SYNOPTIC SCALE LIFT TO SQUEEZE OUT THE LIGHT PRECIP.
EXPECT -SN TO SPREAD INTO WESTERN CWA DURING THE EARLY
EVENING...EVENTUALLY CLEARING THE EASTERN AREAS BY LATE IN THE
NIGHT. SNOW LIQUID RATIOS AROUND 14 TO 1 BUT DENDRITES SHOULD REMAIN
SMALL. HENCE LOOKING AT ONE HALF INCH TO 2 INCH AMOUNTS WITH THE
HIGHEST TOTALS IN THE NORTH AND WEST.
SATURDAY AND SATURDAY NIGHT...FORECAST CONFIDENCE - MEDIUM.
BRIEF LULL IN PRECIPITATION EXPECTED LATER FRIDAY NIGHT INTO
SATURDAY MORNING BEFORE NEXT PERIOD OF -SN DEVELOPS. ALL SHORT TERM
GUIDANCE SHOWS SOUTHERN WISCONSIN AFFECTED BY RIGHT ENTRANCE REGION
OF PASSING UPPER JET SATURDAY AFTN AND EVENING. WITH LOW LEVEL
BAROCLINIC ZONE REMAINING NEARBY...WEAK WARM AIR ADVECTION LOWERS
CONDENSATION PRESSURE DEFICITS RAPIDLY TO LESS THAN 10MB WITH WEAK
ISENTROPIC OMEGA. MORE OF THE CLOUD BEARING LAYER WILL BE IN A
FAVORABLE DENDRITIC SNOW GROWTH REGION FOR A TIME. WITH SLIGHTLY
HIGHER SNOW LIQUID RATIOS EXPECTED AND BETTER ENHANCED
FORCING...THINKING POTENTIAL FOR 2 TO 4 INCH SNOWFALL OVER MOST OF
THE AREA SATURDAY AFTN AND EVENING.
SUNDAY...FORECAST CONFIDENCE - LOW.
SYNOPTIC SCALE FORCING SLIDES OFF TO THE EAST LATE SATURDAY NIGHT
HOWEVER LATEST NAM TRYING TO SHOW A PERIOD OF ONSHORE WINDS AS
MESOSCALE LOW PRESSURE TROUGH MOVES WWD ACROSS LAKE MI INTO FAR
EASTERN WI ON SUNDAY. GFS DOES NOT SHOW THIS FEATURE WITH WEAKER
ONSHORE WINDS AND POTENTIAL LAKE EFFECT REMAINING FARTHER SOUTH OVER
NORTHEAST IL. TOO MUCH UNCERTAINTY TO LEAN ONE WAY OR THE OTHER.
FOR NOW WILL KEEP SMALL POPS FOR -SHSN IN FOR SUNDAY. EXPANDING LAKE
ICE OVER NEARSHORE AND WESTERN OPEN WATERS WILL ALSO HELP TO CUT
BACK ON LAKE EFFECT.
LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FORECAST CONFIDENCE -
MEDIUM TRENDING TOWARD LOW.
MORE ZONAL FLOW AT THE MID-LEVELS CONTINUES INTO EARLY NEXT WEEK
WITH SLIGHT WARMING IN SURFACE TEMPERATURES. ZONAL FLOW AND DRIER
AIR ASSOCIATED WITH SPRAWLING HIGH PRESSURE OVER THE NORTHERN PLAINS
HELPS TO DIVERT DEVELOPING LOW PRESSURE SYSTEM TO THE SOUTHEAST OF
WISCONSIN SUNDAY NIGHT AND MONDAY. HOWEVER MAY BE A PERIOD OF
NORTHEAST WINDS ON BACKSIDE OF LOW MOVING ACROSS TN VALLEY REGION.
GFS FORECAST SOUNDINGS FOR MONDAY SHOW MINIMAL LOW LEVEL MOISTURE
AND WEAKER LOW TO MID LEVEL FLOW...SO FOR NOW WL AVOID ADDING
THREAT OF LAKE EFFECT TO EASTERN AREAS EXCEPT IN THE FAR SOUTHEAST.
LOW PRESSURE SYSTEM AFFECTING EAST COAST REGION EARLY NEXT WEEK WILL
RESULT IN MID-LEVEL STEERING FLOW BECOMING MORE NORTHWEST FOR A
TIME. THIS CARRIES SPRAWLING HIGH PRESSURE SYSTEM FROM THE NORTHERN
PLAINS GRADUALLY EWD ACROSS WESTERN GREAT LAKES REGION ON TUESDAY.
HOWEVER AGREEMENT IN MEDIUM RANGE GUIDANCE IN WEAK TROUGH MOVING
SOUTHEAST ACROSS WI IN THE MONDAY NIGHT/TUE TIME FRAME...SO WL NEED
TO CONTINUE SMALL POPS FOR -SN. CLOUDS FROM THIS SYSTEM WILL ALSO
PREVENT RADIATIONAL COOLING AND BITTER COLD TEMPS MON NGT.
HIGH EVENTUALLY MOVES OFF TO THE EAST BY WEDNESDAY. MEDIUM RANGE
GUIDANCE DIVERGES AT THIS POINT AS ECMWF TURNS A BIT MORE WEST TO
SOUTHWEST AT THE MID-LEVELS AHEAD OF NEXT APPROACHING DISTURBANCE.
DGEX ALSO IN THIS CAMP WHILE GFS STEERING FLOW REMAINS MORE
NORTHWEST AND COLDER. BOTH DGEX AND ECMWF AGRESSIVE ON BRINGING
SURGE OF WARM AIR ADVECTION QPF INTO THE AREA LATER WED/WED
NGT...WHILE GFS SLOWER. NO MATTER...ALL MEDIUM RANGE GUIDANCE IN
AGREEMENT ON STRONGER MID-LEVEL TROUGH MOVING THROUGH THE REGION IN
THE THU/THU NGT TIME FRAME...SO MOST LATER PERIODS WL LIKELY HAVE
LOW POPS FOR -SN.
GFS 5-DAY 500H HEIGHTS RUNNING AROUND 100METERS BELOW NORMAL NEXT
SEVERAL DAYS BUT BEGIN TO SLOWLY MODERATE SO THAT BY THE SECOND WEEK
OF MARCH 500H HEIGHTS ACTUALLY AROUND NORMAL. HENCE WILL REMAIN
COLD AND BELOW NORMAL THROUGH THE EXTENDED FORECAST PERIOD BUT
RECORD COLD NOT EXPECTED.
AVIATION/00Z TAFS/...VFR MOSTLY SKC EXPECTED INTO THIS EVENING.
WILL START TO SEE SOME WAA MID CLOUDS RETURN LATER TONIGHT THROUGH
FRIDAY MORNING. ANY SNOW WITH NEXT SYSTEM EXPECTED TO HOLD OFF UNTIL
FRIDAY EVENING FOR THE TAF SITES. EXPECT MVFR CIGS/VSBYS TO INCREASE
ACROSS SRN WI DURING FRIDAY EVENING PER NAM MOS CIG FCST AND BUFKIT
LOW LEVEL SATURATION TRENDS.
MARINE...GRADIENT WILL TIGHTEN BACK UP AS HIGH SHIFTS EAST AND SSE
FLOW DEVELOPS BETWEEN THE DEPARTED HIGH AND APPROACHING LOW. HOISTED
SMALL CRAFT FOR GUSTY SSE WINDS FROM MID MORNING THROUGH LATE
AFTERNOON.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM CST FRIDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/FRIDAY AND AVIATION/MARINE...COLLAR
FRIDAY NIGHT THROUGH THURSDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
314 PM CST WED FEB 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 314 PM CST WED FEB 26 2014
THE MAIN FOCUS FOR TONIGHT INTO TOMORROW IS WITH THE BLOWING SNOW
TONIGHT FOLLOWED BY COLD WIND CHILLS TOMORROW MORNING.
CURRENTLY...GUSTY SOUTHWEST WINDS ARE OCCURRING THROUGH MUCH OF
THE REGION AS A SURFACE LOW PROPAGATES EAST ACROSS THE UPPER GREAT
LAKES. THE STRONGEST WINDS HAVE BEEN ACROSS THE TYPICAL AREAS IN
SOUTHEAST MINNESOTA AND NORTHEAST IOWA WHERE SOME BLOWING AND
DRIFTING SNOW HAS ALREADY REDUCED VISIBILITIES INTO THE 1 TO 2SM
RANGE. AS THE MAIN MID LEVEL CLOSED LOW DROPS TO THE SOUTHEAST
ACROSS ONTARIO AND A COLD FRONT MOVES THROUGH THE REGION
TONIGHT...THE GRADIENT WILL TIGHTEN UP AS COLDER AIR GETS ADVECTED
IN FROM THE NORTHWEST WITH SOME LIGHT SNOW ALSO OCCURRING.
UPSTREAM OBSERVATIONS AND FORECAST SOUNDINGS FROM THE 26.12Z
NAM/GFS AND THE 26.18Z RAP SUGGEST THAT WINDS WILL COME AROUND TO
THE NORTHWEST AFTER THE FROPA AND QUICKLY INCREASE WITH SUSTAINED
WINDS IN THE 20 TO 30 MPH RANGE AND GUSTS AROUND 40 MPH FOR THIS
EVENING. THIS WILL LEAD TO MORE WIDESPREAD BLOWING AND DRIFTING
SNOW...PARTICULARLY IN SOUTHEAST MINNESOTA...NORTHEAST IOWA AND
NORTH CENTRAL WISCONSIN WHERE THE WINDS WILL BE THE HIGHEST AND
THE SNOW PACK IS THE EASIEST TO BE PUSHED AROUND.
BECAUSE OF THIS...THE MAIN CONCERN WAS WITH WHETHER THE ADVISORY
NEEDED TO BE UPGRADED TO A BLIZZARD WARNING AND ALSO WHETHER THE
ADVISORY NEEDED TO BE EXPANDED EAST AT ALL. CONFIDENCE IS NOT HIGH
ENOUGH TO GO THE BLIZZARD ROUTE AT THIS POINT BECAUSE THERE HAS
NOT BEEN A RECENT ACCUMULATING SNOW TO BLOW AROUND OVER THE TOP OF
THE OLDER SNOW PACK. SO...WHILE SNOW WILL BLOW AND CAUSE SOME
REDUCED VISIBILITIES AND SNOW COVERED ROADS...CONFIDENCE IS NOT
HIGH ENOUGH TO THINK THAT THERE WILL BE WIDESPREAD ROAD CLOSURES
AND WHITEOUT CONDITIONS.
AS THE FRONT MOVES OFF TO THE EAST...THE COLDER AIR WILL COME INTO
THE REGION AND...WHEN COMBINED WITH THE STILL GUSTY WINDS...WILL
CAUSE WIND CHILLS TO DROP DOWN INTO THE 20 TO 35 DEGREES BELOW
ZERO RANGE LATE TONIGHT THROUGH TOMORROW MORNING. TOYED WITH THE
NEED FOR A WIND CHILL WARNING...BUT BASED ON THE FORECAST...WIND
CHILLS ONLY DROP TO 35 BELOW ACROSS PORTIONS OF SE MN/NE IA/NC WI
FOR A BRIEF PERIOD TOMORROW MORNING. THUS...WENT WITH AN ADVISORY
FROM 3AM THROUGH NOON TOMORROW.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 PM CST WED FEB 26 2014
THE MAIN FOCUS THROUGH THE EXTENDED PERIOD IS ON THE TWO MAIN
CHANCES FOR SNOW WHICH COME ON FRIDAY AND THEN ON
SATURDAY/SATURDAY NIGHT.
THE FRIDAY SYSTEM IS SHOWING GOOD CONTINUITY IN REGARD TO
TIMING...BUT HAS SOME DIFFERENCES IN STRENGTH BETWEEN THE 26.12Z
NAM/GFS/ECMWF. THIS SNOW IS STRICTLY COMING FROM TWO FORMS OF LOW
LEVEL FORCING...THE FIRST BEING 850MB WARM AIR ADVECTION AND THEN
A FRONTOGENETIC BAND THAT APPEARS TO BE THE STRONGEST AROUND
700MB. THE INITIAL WEST TO EAST BAND OF SNOW APPEARS TO DEVELOP
ALONG THE NOSE OF THE STRONGEST LOW LEVEL WARM AIR ADVECTION
FRIDAY MORNING/EARLY AFTERNOON WITH THE FRONTOGENESIS
STRENGTHENING ALONG A SOUTHWEST TO NORTHEAST BAND FRIDAY
AFTERNOON. THE HIGHER RESOLUTION 26.12Z NAM IS COMING IN WITH SOME
STRONGER LOW LEVEL LIFT AND IS PRODUCING SOME HIGHER PRECIPITATION
TOTALS WHILE THE 26.12Z GFS/ECMWF AS WEAKER AND HAVE ABOUT HALF OF
THE QPF THAT THE NAM HAS. WITH SNOW RATIOS LOOKING LIKE THEY WILL
BE AROUND 17:1...THE GOING FORECAST OF 1 TO 4 INCHES STILL LOOKS
GOOD...BUT TRENDS WILL HAVE TO BE WATCHED FOR WHETHER THIS
FRONTOGENESIS ENDS UP BEING STRONG ENOUGH TO PRODUCE SOME LOCALLY
HIGHER AMOUNTS. THE 26.15Z SREF PLUMES SHOW THAT MOST OF THE
MEMBERS...INCLUDING THE MEAN...ARE IN THE 1 TO 4 INCH RANGE...BUT
THERE ARE SOME MEMBERS THAT ARE PUSHING THAT 6 INCH THRESHOLD.
THE NEXT ROUND OF SNOW WILL COME ON SATURDAY AND SATURDAY NIGHT
THANKS TO SOME BROAD MID LEVEL TROUGHING DIGGING DOWN INTO THE
UPPER MISSISSIPPI RIVER VALLEY AND A TIGHTENING LOW TO MID LEVEL
TEMPERATURE GRADIENT THAT LEADS TO SOME WEAK TO MODERATE
FRONTOGENESIS. STILL SOME DIFFERING OPINIONS BETWEEN THE 26.12Z
GFS/ECMWF/GEM WITH WHERE THIS SNOW ENDS UP TRACKING...BUT THE
HIGHEST PROBABILITIES LIE ACROSS NORTHEAST IOWA INTO FAR SOUTHWEST
WISCONSIN.
BEYOND THIS...THE COLD CONTINUES THROUGH THE EARLY PART OF NEXT
WEEK WITH SOME POSSIBLE LOW LEVEL WARMING COMING ON WEDNESDAY.
THE 26.12Z ECMWF SUGGESTS THAT A SYSTEM COULD COME THROUGH ON
TUESDAY/WEDNESDAY AND BRING SOME LIGHT SNOW ACROSS SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1143 AM CST WED FEB 26 2014
MAIN AVIATION FORECAST CONCERNS THROUGH THE PERIOD ARE THE
INCREASING WINDS AT BOTH RST AND LSE TAF SITES THIS AFTERNOON INTO
TONIGHT. LATEST SURFACE PLOT SHOWS PRESSURE GRADIENT TIGHTENING
ACROSS MUCH OF THE AREA OUT AHEAD OF A COLD FRONT OVER EXTREME
NORTHWEST MINNESOTA AND CENTRAL NORTH DAKOTA. WINDS THIS AFTERNOON
WILL CONTINUE TO INCREASE FROM THE SOUTHWEST AT BOTH TAF
SITES...WITH SUSTAINED WINDS OF 15 TO 20 KNOTS AND GUSTS OF 25 UP
TO 30 KNOTS. THIS WILL CAUSE SOME DRIFTING OR BLOWING SNOW AT RST
BY 21Z WEDNESDAY AND POSSIBLY REDUCTION IN VISIBILITY BELOW 5
MILES. A COLD FRONT IS EXPECTED TO MOVE ACROSS AROUND 00Z
THURSDAY AT BOTH TAF SITES AND CHANGE WIND DIRECTION TO THE
NORTHWEST. THE STRONG WINDS WILL CONTINUE INTO TONIGHT...AS THE
PRESSURE GRADIENT REMAINS TIGHT BEHIND THE FRONT. WINDS COULD GUST
AS HIGH AS 40 KNOTS AT RST AND UP TO 35 KNOTS AT LSE THIS EVENING.
THE BLOWING AND DRIFTING SNOW COULD REDUCE VISIBILITY DOWN BELOW
THREE MILES AT TIMES AT RST BETWEEN 00-05Z THURSDAY. FOR NOW HAVE
INTRODUCED MARGINAL MVFR VISIBILITY RESTRICTION AT RST THIS
EVENING. WITH THE COLD FRONT PASSAGE...THE LATEST 26.12Z MODELS
ARE HINTING OF A FEW HOURS OF MVFR CEILING CONDITIONS AT BOTH RST
AND LSE THIS EVENING. HAVE LEFT THIS MVFR CEILING CONDITION AT
BOTH TAF SITES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR WIZ017-029.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR MNZ079-086-
087-094-095.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR MNZ079-
086>088-094>096.
IA...WINTER WEATHER ADVISORY UNTIL 3 AM CST THURSDAY FOR IAZ008>010-
018-019-029.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...DTJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
242 PM CST WED FEB 26 2014
.TONIGHT AND THURSDAY - CONFIDENCE...MEDIUM
MAIN FOCUS ON THE BITTER COLD. EVENING FORECAST ISSUE WILL BE SHSN
DEVELOPMENT. SHORTWAVE ENERGY SHIFTS FROM NRN WI TO THE EASTERN LAKES.
LOW LEVEL FRONTOGENETICAL FORCING WITH RENEWED ARCTIC SURGE ALONG WITH
STEEP LOW LEVEL LAPSE RATES...SHOULD BE ENOUGH TO GENERATE A FEW-SCT
SHSN. NAM HI-RES AND HRRR BOTH AND 4KM SPC WRF ALL SHOW THIS DEVELOPMENT
THIS EVENING WITH ANY LINGERING PRECIP WRAPPING UP AROUND 6Z. ONLY A
FEW TENTHS OR SO AND SOME BLOWING TO GO ALONG WITH IT. STRONG COLD
ADVECTION SURGE AFTER 6Z CONTINUES INTO MIDDAY WITH 925 TEMPS
BOTTOMING OUT AROUND -22 TO -25C BETWEEN 12 AND 18Z. WITH AIRMASS
WELL MIXED TEMPS WILL NOT BOTTOM OUT TO THAT POTENTIAL BUT TEMPS
WILL DROP BY PURE ADVECTION. THIS IN CONCERT WITH TIGHT PRESSURE
GRADIENT WILL ALLOW WIND CHILL ADVISORY CRITERIA TO BE MET ONCE
AGAIN...SO HAVE HOISTED ONE FROM 09-18Z.
.THURSDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
HIGH PRESSURE WILL SLIDE ACROSS THE AREA...WITH THE CENTER OF THE
HIGH PASSING OVER THE DUBUQUE AREA EARLY IN THE EVENING. BY 6AM
FRIDAY MORNING THE HIGH IS OVER ERN OH/WRN PA WITH THE LOW LEVEL
FLOW STARTING TO PICK UP ACROSS THE FORECAST AREA. THIS HAS BEEN
A TRICKY PERIOD WITH RESPECT TO LOW TEMPS DUE TO THE POTENTIAL FOR
STRONG RADIATIONAL COOLING. THE GFS HAS BEEN THE MOST AGGRESSIVE
OVER THE LAST FEW DAYS AND CONTINUES TO BE THE EXTREME.
WARM ADVECTION HEADING TOWARD THE AREA WILL CAUSE HIGH CLOUDS TO
SPREAD IN FROM THE WEST AFTER MIDNIGHT. JUST HOW COLD WE CAN GET
BEFORE THAT BLANKET ARRIVES IS THE BIGGEST QUESTION. THE GUIDANCE
IS NOW SUGGESTING THE COLDEST READINGS WILL BE ALONG AND JUST WEST
OF THE KETTLE MORAINE SPINE IN SOUTHEAST WISCONSIN. THE HILLS OUT
WEST OF MADISON MAY NOT TANK TOO LOW DUE TO THE EXPECTED CLOUDS
AND BREEZE KICKING IN. IN GENERAL...HAVE BACKED OFF A BIT ON WHAT
WE HAD GOING...BUT STILL WELL BELOW ZERO MOST PLACES. FAVORED
COLD SPOTS IN LOW AREAS COULD GET SURPRISINGLY COLD.
.FRIDAY AND FRIDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE WARM ADVECTION MENTIONED ABOVE WILL ARRIVE AHEAD OF AN
INVERTED TROF THAT WILL ENTER WESTERN WISCONSIN FRIDAY AFTERNOON.
SNOW SHOULD BEGIN TO SPREAD INTO THE WEST TOWARD LATE MORNING AND
THE REST OF THE FORECAST AREA DURING THE DAY AND CONTINUE THROUGH
THE EVENING BEFORE EXITING TO THE EAST AFTER MIDNIGHT. WE COULD
SEE 2 TO 3 INCHES OF DRY SNOW WITH THIS.
.SATURDAY INTO SUNDAY NIGHT...FORECAST CONFIDENCE IS MEDIUM.
THE OVERALL FLOW WILL HAVE BECOME ZONAL BY SATURDAY WITH A FEW
RIPPLES MOVING THROUGH THE AREA...MAINLY AFFECTING FAR SOUTHERN
WISCONSIN. TEMPERATURES WILL ALSO MODIFY...OR WARM...FROM THEIR
DEEP CHILL...BUT STILL REMAIN BELOW NORMAL. AT THE SURFACE HIGH
PRESSURE WILL STRETCH FROM THE NORTHERN PLAINS INTO THE GREAT
LAKES. THE WEAK MID LEVEL SHORT WAVES MOVING THROUGH WILL ONLY
BRING CHANCES OF SOME FAIRLY LIGHT SNOW. NOTHING MAJOR...BUT WE/LL
HAVE A CHANCE FOR SNOW MAINLY FROM SATURDAY AFTERNOON INTO
SUNDAY...TAPERING OFF OR ENDING BY SUNDAY NIGHT.
.MONDAY AND MONDAY...FORECAST CONFIDENCE IS MEDIUM.
THE HIGH OVER THE PLAINS IS EXPECTED TO DRIFT INTO THE AREA...BUT
THE GFS AND ECMWF DIFFER ON THE SPEED/STRENGTH/PLACEMENT OF THAT
HIGH BY MONDAY NIGHT. EITHER WAY...IT LOOKS DRY.
&&
.AVIATION/00Z TAFS/...HRRR/NAM HI-RES AND OTHER SYNOPTIC MODELS
SHOWING RELATIVELY SMALL WINDOW OF SHSN POTENTIAL THIS EVENING. THIS
ASSOCIATED WITH NEXT ARCTIC BOUNDARY AND POTENT SHORTWAVE MOVING
FROM NRN WI INTO LOWER MI. VFR CONDITIONS WILL BE PREVALENT MOST OF
THIS PERIOD BUT EXPECT LOCALIZED VSBYS/CIGS TO DROP TO MAINLY MVFR
WITH ANY SHSN THAT DEVELOP OR ADVECT IN. THIS WOULD MOSTLY BE IN THE
01Z-06Z TIME FRAME.
&&
.MARINE...DECIDED TO HOIST A GALE WARNING FOR MIDNIGHT THROUGH NOON.
SEEING PRETTY DECENT SIGNALS ON BUFKIT FOR A PERIOD OF GALES IN THE
WAKE OF THE LATEST ARCTIC FRONT COMING THROUGH THIS EVENING. THE GOING
SMALL CRAFT WILL LEAD UP TO THE GALE WARNING AND THEN WILL LIKELY BE
NEEDED FOR A WHILE AT THE CONCLUSION OF THE GALE WARNING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 3 AM TO NOON CST THURSDAY FOR WIZ046-
047-051-052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM CST THURSDAY FOR LMZ643>646.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...COLLAR
THURSDAY NIGHT THROUGH WEDNESDAY...DAVIS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
251 AM MST FRI FEB 28 2014
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL ARRIVE TODAY WITH
WIDESPREAD SHOWERS BEGINNING IN SOUTHEAST CALIFORNIA DURING THE
MORNING...THEN SPREADING INTO ARIZONA THROUGH THE AFTERNOON AND
EVENING HOURS. PERIODIC RAIN SHOWERS AND EVEN A FEW THUNDERSTORMS
WILL BE POSSIBLE THROUGH THE WEEKEND. CONDITIONS WILL GRADUALLY DRY
OUT FROM WEST TO EAST SUNDAY WITH HIGH PRESSURE AND NORMAL
TEMPERATURES RETURNING EARLY NEXT WEEK.
&&
.DISCUSSION...
VERY WELL DEFINED CIRCULATION REMAINS OFFSHORE THIS MORNING AND
CONTINUES TO OCCLUDE AS OF 09Z. HOWEVER...PRECIPITATION IS ALREADY
FALLING WEST OF THE COASTAL MOUNTAINS AS A SUBSTANTIAL ATMOSPHERIC
RIVER WITHIN THE WARM CONVEYOR BELT MOVES ONSHORE. THE NEARLY
PERPENDICULAR UPSLOPE COMPONENT TO THE 700-850MB WINDS IS CERTAINLY
HELPING MATTERS AS WELL WITH WINDS ANALYZED AROUND 60-70KTS. WHILE
THE FORECAST AREA REMAINS DRY AT THE MOMENT...ITS SIMPLY A MATTER
OF TIME BEFORE THE BOUNDARY LAYER SATURATES SUFFICIENTLY AND
PRECIPITATION BEGINS. BLENDED TPW IMAGERY REVEALS APPROXIMATELY 0.5
INCH PWATS ACROSS THE LOWER AZ DESERTS...WITH SLIGHTLY HIGHER VALUES
ACROSS SOUTHEAST CALIFORNIA...SUBSTANTIALLY HIGHER VALUES /AROUND
1.25 INCHES/ OFF THE SAN DIEGO COAST...AND APPROXIMATELY 1.8 INCHES
A BIT FARTHER WEST. SUFFICE TO SAY THE ATMOSPHERE HAS PLENTY OF
MOISTURE TO WORK WITH...ONLY QUESTION IS HOW QUICKLY IT WILL BE
IMPORTED OVER THE COASTAL MOUNTAINS AND THE BAJA SPINE AND INTO THE
LOWER AZ DESERTS.
ALL MODEL GUIDANCE INDICATES MOISTURE WILL MAKE ITS WAY INTO
SOUTHEAST CALIFORNIA LATER THIS MORNING...NAM...HRRR...LOCAL
WRFS...AND EVEN THE MORE COARSE GUIDANCE ARE ON BOARD. WHILE A
FEW SHOWERS ARE POSSIBLE THIS MORNING AROUND EL CENTRO AND BLYTHE
AND CERTAINLY ACROSS JOSHUA TREE NATIONAL PARK...ACTIVITY SHOULD
PICK UP SUBSTANTIALLY THIS AFTERNOON AS CONVECTION DEVELOPS OVERHEAD
AND FILLS IN WITH THE INITIAL PRE-FRONTAL TROUGH. THE PRESENCE OF
RELATIVELY STEEP MID LEVEL LAPSE RATES AND A FEW HUNDRED J/KG MLCAPE
WILL ALSO HELP THINGS ALONG LATER THIS MORNING/AFTERNOON.
ARGUABLY...LATE THIS MORNING THROUGH THIS AFTERNOON COULD BE
SOUTHEAST CALIFORNIAS BUSIEST PERIOD DURING THIS ENTIRE EVENT. POPS
WERE ALREADY AT OR NEAR 100 PERCENT FOR TODAY AND I ONLY MADE VERY
MINOR ADJUSTMENTS. MAINTAINED THE MENTION OF THUNDER AS WELL...GIVEN
AFOREMENTIONED LAPSE RATES AND MLCAPES...THIS ALSO MATCHES SPCS DAY
1 GENERAL THUNDER OUTLINE...BUT I STILL THINK WIDESPREAD SEVERE
WEATHER IS UNLIKELY. HOWEVER...WINDS WILL BE A FACTOR ESPECIALLY
ACROSS THE HIGHER TERRAIN OF JOSHUA TREE NATIONAL PARK AND THE
USUALLY WINDY I-8 CORRIDOR OF IMPERIAL COUNTY. GOING WITH A WIND
ADVISORY TODAY INTO THIS EVENING BUT THE VAST MAJORITY OF AREAS
DOWNWIND OF THE COASTAL MOUNTAINS SHOULD BE SPARED THE STRONGEST
WINDS.
THE BIGGEST CHALLENGE THIS MORNING IS DECIDING WHEN PRECIP WILL
BEGIN ACROSS THE LOWER AZ DESERTS AND AROUND THE PHOENIX AREA. WHILE
TRYING NOT TO FOCUS TOO CLOSELY ON ONE OR TWO DETERMINISTIC
SOLUTIONS...ALL THE 00Z HI-RES GUIDANCE INCLUDING THE NAM12...4KM
NAM...LOCAL WRFS...NSSL WRF...HRRR...AND RAP INDICATE PRECIP WILL
HOLD OFF UNTIL WELL AFTER 00Z AROUND THE PHOENIX AREA. PER THEIR
SOLUTIONS...PRECIP WILL DEVELOP IN THE MOUNTAINS NORTH/EAST OF
PHOENIX FIRST...THEN GRADUALLY BACKFILL OVER THE METRO AS ADDITIONAL
MOISTURE IS IMPORTED INTO THE AREA. FOR BETTER OR WORSE...THIS
BACKFILLING DOESNT TAKE PLACE UNTIL CLOSER TO 12Z SATURDAY...ABOUT
12 HRS SLOWER THAN PREVIOUSLY THOUGHT. GIVEN THE VERY STRONG
ISENTROPIC LIFT THAT WILL BE OVERHEAD LATE THIS EVENING ALONG WITH
NEARLY 50KT SOUTHERLY 850MB WINDS AND PWATS AROUND 1.2-1.3
INCHES...IM NOT CONVINCED IT WILL STAY DRY ALL THE WAY THROUGH
SATURDAY MORNING. I MADE SLIGHTLY DOWNWARD ADJUSTMENTS TO POPS
ACROSS THE DESERTS FOR THIS EVENING/OVERNIGHT BUT VALUES ARE STILL
RUNNING IN THE 80-90 PERCENT RANGE. THE HIGHER TERRAIN NORTH/EAST OF
PHOENIX IS STILL AT 100 PERCENT AS THEY SHOULD BE THE FIRST TO SEE
PRECIP DEVELOPMENT.
MODELS ARE TRENDING TOWARD SLIGHTLY HIGHER VALUES OF MLCAPE DURING
THE DAY ON SATURDAY...ALONG WITH SLIGHTLY HIGHER VALUES OF 0-1KM
0-3KM AND 0-6KM SHEAR. CONFIDENCE INCREASING THAT THERE WILL INDEED
BE THUNDER AROUND DURING THE DAY ON SATURDAY...BUT WITH QUITE A BIT
OF CLOUD COVER WIDESPREAD SEVERE STILL SEEMS UNLIKELY. PERHAPS A FEW
SHOWERS THAT ARE CAPABLE OF LOCALLY GUSTY WINDS...BUT THATS ABOUT
IT. ACROSS SOUTHEAST CALIFORNIA I THINK THERE COULD BE A FEW SHOWERS
ON SATURDAY BUT ISENTROPIC DOWNGLIDE ON THE 295-310K SURFACES STARTS
BECOMING EVIDENT AS EARLY AS 12-18Z SATURDAY. ACTIVITY MAY END UP
BEING FAIRLY SCATTERED IN NATURE BUT GIVEN THE LARGE SWATH OF
MOISTURE THAT WILL STILL BE IN PLACE...HESITANT TO REDUCE POPS TOO
MUCH.
THE 1.2 INCH PWAT AXIS SHIFTS INTO THE MOUNTAINS EAST OF PHOENIX
SATURDAY EVENING AND A DRYING TREND SHOULD COMMENCE ACROSS THE
ENTIRE FORECAST AREA /EXCLUDING GILA CO/ DURING THE EVENING HOURS.
LINGERING MOISTURE WILL ALLOW FOR A FEW SHOWERS ON SUNDAY BUT THE
VAST MAJORITY OF THESE SHOWERS SHOULD BE IN THE MOUNTAINS WELL EAST
OF PHOENIX. HELD ONTO AT LEAST A SLIGHT CHANCE MENTION OF POPS
SUNDAY INTO SUNDAY AFTERNOON BUT FOR THE DESERTS...RAINFALL SHOULD
BE PRETTY MUCH OVER AND DONE WITH. WHAT DOES THIS MEAN FOR STORM
TOTAL AMOUNTS? A BLEND OF WPC PROVIDED QPF AND GFS/EUROPEAN QPF
YIELDS ABOUT 0.25 TO 0.5 INCHES ACROSS SOUTHEAST CALIFORNIA...AROUND
0.75 TO 1 INCHES AROUND THE PHOENIX AREA...AND UPWARDS OF 1.5 EAST
OF PHOENIX. NATURALLY...HIGHER AMOUNTS ARE EXPECTED WITHIN THE
STRONGER SHOWERS/STORMS BUT OVERALL THESE VALUES FIT IN WELL WITH
CIPS ANALOGS. WILL HOLD OFF ISSUING ANY SORT OF FLOOD WATCHES BUT
NUISANCE FLOODING OF LOW LYING AREAS AND/OR NORMALLY DRY WASHES
CANT BE RULED OUT. SNOWFALL POTENTIAL REMAINS LIMITED AS THIS
SYSTEM WILL CONTINUE TO IMPORT WARM SOUTHERLY AIR INTO THE REGION
UNTIL SUNDAY. SNOW LEVELS WILL DROP TO AROUND 6500FT ON SUNDAY AS
PRECIP IS DRAWING TO A CLOSE. ASIDE FROM THE TOPS OF THE VERY
HIGHEST PEAKS EAST OF PHOENIX...SNOWFALL APPEARS HIGHLY UNLIKELY.
THE WEATHER TURNS MUCH MUCH QUIETER FROM MONDAY ONWARD AS WEAK ZONAL
FLOW TRANSITIONS INTO WEAK RIDGING BY MID WEEK. DRY WEATHER IS A
LOCK FROM MONDAY ONWARD ALONG WITH STEADILY INCREASING TEMPS
EVENTUALLY REACHING THE LOWER 80S TOWARD THE END OF THE WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
HIGH CLOUDS WILL INCREASE THROUGH FRIDAY MORNING...WITH CIGS
DEVELOPING AOA 10K FT BY FRIDAY AFTERNOON AND LOWERING BELOW 8K FT
BY FRIDAY EVENING AS SHOWERS DEVELOP. FEEL COVERAGE THROUGH 00Z WILL
BE SPARSE...AND ONLY HAVE A VCSH MENTION. WHILE AN ISOLD TS MAY BE
POSSIBLE...CHANCES ARE FAR TOO LOW TO MENTION. SFC WINDS WILL SWITCH
TO EASTERLY TONIGHT...THEN MAY OBTAIN A PROLONGED SLY CROSS WIND
TRAJECTORY FRIDAY AFTERNOON...THOUGH IT APPEARS SPEEDS WILL REMAIN
BELOW 14KT.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH...
CIGS WILL THICKEN AND LOWER OVERNIGHT...FALLING TO A 7K-8K FT LEVEL
BY FRIDAY MORNING AS SHOWERS BEGIN TO DEVELOP THROUGHOUT SERN
CALIFORNIA. COVERAGE APPEARS TOO SPOTTY TO INCLUDE A PREVAILING
GROUP DURING THE MORNING HOURS. HOWEVER...ANOTHER ROUND OF SHOWERS
WITH BETTER COVERAGE MAY DEVELOP FRIDAY AFTERNOON. WHILE AN ISOLD TS
MAY BE POSSIBLE...CHANCES ARE FAR TOO LOW TO MENTION. THERE IS LOW
CONFIDENCE REGARDING PREVAILING SFC WIND DIRECTIONS...AS COVERAGE
AND LOCATION OF SHOWERS MAY CREATE RAPIDLY SHIFTING WINDS THROUGH
THE PERIOD. IN GENERAL...PREVAILING S/E WINDS WOULD BE PREFERRED IN
THE MORNING...BECOMING S/W IN THE AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A LOW PRESSURE SYSTEM WILL CONTINUE MOVING THROUGH THE REGION WITH
PRECIPITATION STARTING TO TAPER OFF FROM WEST TO EAST SATURDAY
AFTERNOON. HOWEVER...PRECIPITATION CHANCES LINGER THROUGH
SUNDAY...ESPECIALLY OVER THE HIGHER TERRAIN OF SOUTH-CENTRAL
ARIZONA. PRECIPITATION TOTALS WILL BE SUBSTANTIALLY HIGHER EAST OF
THE LOWER COLORADO RIVER VALLEY THAN OVER SOUTHEAST CALIFORNIA.
LOCALLY BREEZY CONDITIONS CAN BE EXPECTED ON THE VALLEY FLOORS
SATURDAY WITH VERY STRONG WINDS AT RIDGETOPS. TEMPERATURES WILL BE
BELOW NORMAL SATURDAY AND SUNDAY AND HUMIDITIES WILL BE ELEVATED.
EXPECT WARMER TEMPERATURES AND LOWER HUMIDITIES MONDAY THROUGH
WEDNESDAY ALONG WITH LESS WIND.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
CAZ033.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR CAZ030.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...MO
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1235 AM EST FRI FEB 28 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN THROUGH FRIDAY...SLOWLY RETREATING TO THE
NORTHEAST FRIDAY NIGHT AND SATURDAY. FAIR WEATHER ON SATURDAY WILL
BE FOLLOWED BY A COLD FRONTAL PASSAGE ON SUNDAY. SNOW IS THEN
EXPECTED FOR THE BEGINNING OF NEXT WEEK. CANADIAN HIGH PRESSURE
BUILDS IN BEHIND THE STORM.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MAIN ISSUE OVERNIGHT IS THE COLD. TEMPERATURES FALLING OFF MORE
RAPIDLY THAN FORECAST...SO HAVE UPDATED BLENDING IN HRRR 2-METER
TEMPERATURES...RESULTING IN LOWERING LOWS A FEW DEGREES ACROSS THE
REGION. LOWS GENERALLY FROM -5 TO 0 ACROSS FAR NW ZONES...AND IN
THE POSITIVE SINGLE DIGITS ELSEWHERE.
THESE TEMPERATURES COMBINED WITH 10 TO 20 MPH WINDS
OVERNIGHT...YIELDS WIND CHILLS EXPECTED TO FALL TO -5 TO -10
FOR CITY AND COAST...AND -10 TO -15 ACROSS THE INTERIOR. COULD SEE
SOME POCKETS ACROSS ORANGE/PUTNAM/N FAIRFIELD COUNTY THAT COULD
GET JUST BELOW -15...BUT WITH LESS THAN 1/2 OF ZONE EXPECTED TO
SEE THIS...WILL NOT ISSUE WIND CHILL ADVISORY AT THIS TIME. CURRENT
SPS ADDRESSES WIND CHILLS OVERNIGHT.
STRONG PRESSURE GRADIENT BETWEEN THE DEPARTING STORM TO THE
NORTHEAST AND HIGH BUILDING IN FROM THE WEST...WILL RESULT IN
WINDS OF 20 TO 30 MPH WITH GUSTS 35 TO 45 MPH TO GET
STARTED....THAT WILL SLOWLY SUBSIDE DURING THE OVERNIGHT HOURS AS
THE PRESSURE GRADIENT WEAKENS IN RESPONSE TO THE HIGH MOVING
CLOSER TO THE AREA.
CONTINUED CLEAR OVERNIGHT WITH SUBSIDENCE ASSOCIATED WITH RISING
HEIGHTS AS DEEP LAYERED TROUGH LIFTS TO THE NORTHEAST...AND HIGH
PRESSURE BUILDING IN AT THE SURFACE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
NEAR ZONAL UPPER FLOW DURING THIS TIME...WITH SURFACE HIGH PRES
BUILDING OVER THE REGION FRIDAY AND EAST FRIDAY NIGHT.
FRIDAY WILL BE THE COLDEST DAY OF THE WEEK WITH HIGHS LIKELY 20
DEGREES BELOW SEASONABLE...STRUGGLING INTO THE MID TO UPPER TEENS
FOR MOST OF THE REGION. WINDS SHOULD BE WEAKENING DURING THE
DAY...ALLOWING SUB ZERO WIND CHILLS TO RECOVER INTO THE TEENS
DURING THE AFTERNOON.
POTENTIAL FOR STRONG RADIATIONAL COOLING FRIDAY NIGHT ACROSS
OUTLYING AREAS...DEPENDING ON HOW QUICKLY HIGH CLOUDS MOVE INTO THE
REGION. IF HIGH CLOUDS HOLD OFF UNTIL LATE...LOWS HAVE POTENTIAL TO
DROP A FEW DEGREES BELOW ZERO ACROSS INTERIOR AND PINE BARRENS OF LI.
ELSEWHERE LOWS GENERALLY IN THE SINGLE DIGITS...WITH TEENS IN THE
URBAN CENTERS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
LOWER 1030S HI BUILDS EASTWARD OVER THE N ATLANTIC SAT. THIS BRINGS
RETURN FLOW TO THE CWA AND WARMER TEMPS. WEAK MOISTURE TRANSPORT
FROM THE SW SHOULD PRODUCE CLOUDY SKIES BY AFTERNOON. SST/S MAINLY IN THE
MID 30S...SO THE ONSHORE FLOW WILL NOT RESULT IN A BIG WARM UP NEAR
THE COASTS.
A MID 1040S HI WILL BE BUILDING SOUTHEASTWARD FROM THE CANADIAN
PRAIRIE SAT NIGHT AND SUN. THE UPPER LEVEL CIRCULATION OVER NRN
ONTARIO AND QUEBEC WILL SERVE TO DRIVE THIS COLD AIRMASS INTO THE
CWA. THE 12Z ECMWF AND GFS HAVE LINED UP WITH THIS FEATURE AT
H5...PRODUCING A NARROW SPREAD IN THE DETERMINISTIC FCST SUN-MON.
AS A RESULT...THE CONSENSUS OF THESE TWO OPERATIONAL MODELS WAS
FOLLOWED FOR THE FCST.
THE ASSOCIATED ARCTIC FRONT PASSES THROUGH THE CWA ON SUN. MOISTURE
TRANSPORT VECTORS INDICATE ADDED MOISTURE ENTRAINED INTO THE
CIRCULATION FROM THE GULF OF MEXICO. AS A RESULT...POCKETS OF LGT
PRECIPITATION...MAINLY SNOW...ARE FCST FOR SUN IN THE VICINITY OF
THE FRONT. ACCUMULATIONS LESS THAN AN INCH...PARTICULARLY WITH THE
LGT SNOWFALL RATES EXPECTED DUE TO WEAK LIFT.
AS THE JET LINES UP N OF THE CWA SUN NIGHT AND MON...THE NEARLY
STATIONARY SFC FRONT BECOMES ESTABLISHED S OF THE CWA. THIS
ALIGNMENT PUTS THE CWA IN THE CONVERGENT ZONE...WITH MID LEVEL FRONTOGENESIS
ENHANCING LIFT. THIS SETUP WOULD PRODUCE AN EXTENDED PERIOD OF
SNOW LATE SUN NIGHT INTO MON NIGHT.
HWO UPDATED TO INCLUDE 8 INCH OR MORE POTENTIAL.
THE POSITION OF THE FRONT WOULD BRING IN N TO NE WINDS THROUGH THE
EVENT...FEEDING THE COLD AIR. A BLEND OF THE PURE GFS AND ECMWF
MODEL DATA GIVES TEENS TO LOWER 20S FOR HIGHS MON...AND TEMPS FROM
ZERO INTO THE LOWER TEENS MON NIGHT. THIS DATA WAS ACCEPTED FOR
THE FCST WITH THE EXPECTATION THAT GUIDANCE LIKELY INFLUENCED BY
CLIMATOLOGY.
ANY DEVIATION TO THIS TRACK COULD LEAD TO SIGNIFICANTLY LESS
PRECIPITATION IF THE CONVERGENCE ZONE SETS UP S...OR TO MORE RAIN
AND/OR ICY MIX IF IT SETS UP FURTHER N.
THE CANADIAN HI THEN SETS UP OVER THE AREA THROUGH AT LEAST
WED...KEEPING THE CWA DRY. TEMPS BELOW CLIMATOLOGY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE GREAT LAKES BUILDS EAST THROUGH FRIDAY WITH
GRADUALLY DIMINISHING WINDS AND VFR CONDITIONS.
GUSTY W-NW FLOW EARLY THIS MORNING DIMINISHES AS HIGH PRESSURE
APPROACHES FROM THE WEST. WINDS GENERALLY 10 KT OR LESS DURING THE
DAYTIME HOURS...THEN LIGHT AND VARIABLE FRIDAY NIGHT WITH THE HIGH
OVERHEAD.
.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.FRI NIGHT AND SAT...VFR.
.SAT NIGHT...MAINLY VFR WITH POSSIBLE MVFR OR LOWER DEVELOPING IN
LIGHT SNOW.
.SUN...MVFR OR LOWER WITH LIGHT SNOW POSSIBLE.
.SUN NIGHT-MON-NIGHT...IFR OR LOWER POSSIBLE IN SNOW.
.TUE...SUB VFR IN SNOW EARLY IN THE MORNING...IMPROVING TO VFR.
&&
.MARINE...
WIND GUSTS OVER THE NON-OCEAN ZONES HAVE FALLEN TO SCA LEVELS...SO
HAVE CANCELLED THE GALE WARNING THERE AND REPLACED WITH AN SCA
FOR THE REMAINDER OF THE OVERNIGHT.
GALE CONDITIONS GRADUALLY SUBSIDE TO SCA FROM W TO E OVERNIGHT.
WILL NEED TO PUT UP ON SCA ON AT LEAST THE EASTERN 2 OCEAN ZONES
TO REPLACE THE GALES AS SEAS WILL BE SLOW TO SUBSIDE.
LIGHT TO MODERATE FREEZING SPRAY FOR THIS EVENING ON THE OCEAN
WATERS AND EASTERN LI SOUND WATERS DUE TO THE STRONG WINDS AND
HIGHS SEAS.
ADDITIONALLY...LOW WATER ADVISORY CONTINUES FOR TONIGHT THROUGH
EARLY FRIDAY MORNING.
HIGH PRESSURE BUILDS OVER THE WATERS FRIDAY INTO FRIDAY NIGHT.
SCA CONDITIONS FRI MORNING...PARTICULARLY EASTERN OCEAN
WATERS...WILL SUBSIDE BY AFTERNOON. TRANQUIL CONDITIONS LATE
FRIDAY THROUGH FRIDAY NIGHT.
WINDS AND SEAS BELOW SCA LEVELS OVER THE WEEKEND...THEN NE WINDS
INCREASE SUN NIGHT WITH AT LEAST SCA LEVEL WINDS MON INTO TUE ON
N TO NE FLOW. GALES POSSIBLE...ESPECIALLY ON THE OCEAN. CONDITIONS
SUBSIDE ON WED WITH HI PRES BUILDING OVER THE WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIP EXPECTED THROUGH SUNDAY.
THE NEXT CHANCE FOR SIGNIFICANT LIQUID EQUIVALENT QPF EXISTS FROM
SUNDAY NIGHT-MONDAY NIGHT. AROUND AN INCH OF LIQUID EQUIVALENT IS
POSSIBLE DURING THIS TIME.
&&
.TIDES/COASTAL FLOODING...
WITH STRONG WNW FLOW AND ASTRONOMICALLY LOW TIDES TONIGHT INTO
EARLY FRIDAY MORNING...WILL CONTINUE WITH A LOW WATER ADVISORY FOR
THE TIMES OF LOW TIDE TONIGHT AS TIDAL DEPARTURES WILL BE AROUND 2
TO 2 1/2 FT BELOW MLLW.
&&
.CLIMATE...
HERE ARE THE RECORD LOW TEMPERATURES AND FORECASTED LOW
TEMPERATURES FOR FRIDAY...FEBRUARY 28 AND SATURDAY MARCH 1...AND
THE RECORD LOW MAXIMUM TEMPERATURES AND FORECASTED HIGH
TEMPERATURES FOR FRIDAY AS WELL.
FRIDAY
LOW TEMPERATURE
SITE........RECORD/YEAR SET...FORECAST LOW
NEWARK..........0/1934............3
BRIDGEPORT.....10/1950............6
CENTRAL PARK....5/1934............6
LAGUARDIA......14/1994............7
KENNEDY........15/1950............7
ISLIP..........13/1994............8
HIGH TEMPERATURE
SITE........RECORD LOW MAX/YEAR SET...FORECAST HIGH
NEWARK............24/1934.................18
BRIDGEPORT........27/1980.................19
CENTRAL PARK......21/1875.................18
LAGUARDIA.........29/2008.................20
KENNEDY...........30/1980,2008............19
ISLIP.............28/1994,2008............19
SATURDAY
SITE........RECORD LOW/YEAR SET...FORECAST LOW
NEWARK..........7/1980............13
BRIDGEPORT......6/1980............9
CENTRAL PARK....5/1884............16
LAGUARDIA.......9/1980............18
KENNEDY.........8/1980............14
ISLIP..........14/1994............8
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...LOW WATER ADVISORY UNTIL 2 AM EST EARLY THIS MORNING FOR
ANZ338-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
ANZ330-335-338-340-345.
LOW WATER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
ANZ330-335-340.
FREEZING SPRAY ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ330-
350-353-355.
GALE WARNING UNTIL 6 AM EST EARLY THIS MORNING FOR ANZ350-353-
355.
&&
$$
SYNOPSIS...JMC/NV
NEAR TERM...JC/MALOIT/NV
SHORT TERM...NV
LONG TERM...JMC
AVIATION...DW
MARINE...JMC/MALOIT/NV
HYDROLOGY...JMC/NV
TIDES/COASTAL FLOODING...
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1206 AM EST FRI FEB 28 2014
.SYNOPSIS...
HIGH PRESSURE BUILDS IN THROUGH FRIDAY...SLOWLY RETREATING TO THE
NORTHEAST FRIDAY NIGHT AND SATURDAY. FAIR WEATHER ON SATURDAY WILL
BE FOLLOWED BY A COLD FRONTAL PASSAGE ON SUNDAY. SNOW IS THEN
EXPECTED FOR THE BEGINNING OF NEXT WEEK. CANADIAN HIGH PRESSURE
BUILDS IN BEHIND THE STORM.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MAIN ISSUE OVERNIGHT IS THE COLD. TEMPERATURES FALLING OFF MORE
RAPIDLY THAN FORECAST...SO HAVE UPDATED BLENDING IN HRRR 2-METER
TEMPERATURES...RESULTING IN LOWERING LOWS A FEW DEGREES ACROSS THE
REGION. LOWS GENERALLY FROM -5 TO 0 ACROSS FAR NW ZONES...AND IN
THE POSITIVE SINGLE DIGITS ELSEWHERE.
THESE TEMPERATURES COMBINED WITH 10 TO 20 MPH WINDS
OVERNIGHT...YIELDS WIND CHILLS EXPECTED TO FALL TO -5 TO -10
FOR CITY AND COAST...AND -10 TO -15 ACROSS THE INTERIOR. COULD SEE
SOME POCKETS ACROSS ORANGE/PUTNAM/N FAIRFIELD COUNTY THAT COULD
GET JUST BELOW -15...BUT WITH LESS THAN 1/2 OF ZONE EXPECTED TO
SEE THIS...WILL NOT ISSUE WIND CHILL ADVISORY AT THIS TIME. CURRENT
SPS ADDRESSES WIND CHILLS OVERNIGHT.
STRONG PRESSURE GRADIENT BETWEEN THE DEPARTING STORM TO THE
NORTHEAST AND HIGH BUILDING IN FROM THE WEST...WILL RESULT IN
WINDS OF 20 TO 30 MPH WITH GUSTS 35 TO 45 MPH TO GET
STARTED....THAT WILL SLOWLY SUBSIDE DURING THE OVERNIGHT HOURS AS
THE PRESSURE GRADIENT WEAKENS IN RESPONSE TO THE HIGH MOVING
CLOSER TO THE AREA.
CONTINUED CLEAR OVERNIGHT WITH SUBSIDENCE ASSOCIATED WITH RISING
HEIGHTS AS DEEP LAYERED TROUGH LIFTS TO THE NORTHEAST...AND HIGH
PRESSURE BUILDING IN AT THE SURFACE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
NEAR ZONAL UPPER FLOW DURING THIS TIME...WITH SURFACE HIGH PRES
BUILDING OVER THE REGION FRIDAY AND EAST FRIDAY NIGHT.
FRIDAY WILL BE THE COLDEST DAY OF THE WEEK WITH HIGHS LIKELY 20
DEGREES BELOW SEASONABLE...STRUGGLING INTO THE MID TO UPPER TEENS
FOR MOST OF THE REGION. WINDS SHOULD BE WEAKENING DURING THE
DAY...ALLOWING SUB ZERO WIND CHILLS TO RECOVER INTO THE TEENS
DURING THE AFTERNOON.
POTENTIAL FOR STRONG RADIATIONAL COOLING FRIDAY NIGHT ACROSS
OUTLYING AREAS...DEPENDING ON HOW QUICKLY HIGH CLOUDS MOVE INTO THE
REGION. IF HIGH CLOUDS HOLD OFF UNTIL LATE...LOWS HAVE POTENTIAL TO
DROP A FEW DEGREES BELOW ZERO ACROSS INTERIOR AND PINE BARRENS OF LI.
ELSEWHERE LOWS GENERALLY IN THE SINGLE DIGITS...WITH TEENS IN THE
URBAN CENTERS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
LOWER 1030S HI BUILDS EASTWARD OVER THE N ATLANTIC SAT. THIS BRINGS
RETURN FLOW TO THE CWA AND WARMER TEMPS. WEAK MOISTURE TRANSPORT
FROM THE SW SHOULD PRODUCE CLOUDY SKIES BY AFTERNOON. SST/S MAINLY IN THE
MID 30S...SO THE ONSHORE FLOW WILL NOT RESULT IN A BIG WARM UP NEAR
THE COASTS.
A MID 1040S HI WILL BE BUILDING SOUTHEASTWARD FROM THE CANADIAN
PRAIRIE SAT NIGHT AND SUN. THE UPPER LEVEL CIRCULATION OVER NRN
ONTARIO AND QUEBEC WILL SERVE TO DRIVE THIS COLD AIRMASS INTO THE
CWA. THE 12Z ECMWF AND GFS HAVE LINED UP WITH THIS FEATURE AT
H5...PRODUCING A NARROW SPREAD IN THE DETERMINISTIC FCST SUN-MON.
AS A RESULT...THE CONSENSUS OF THESE TWO OPERATIONAL MODELS WAS
FOLLOWED FOR THE FCST.
THE ASSOCIATED ARCTIC FRONT PASSES THROUGH THE CWA ON SUN. MOISTURE
TRANSPORT VECTORS INDICATE ADDED MOISTURE ENTRAINED INTO THE
CIRCULATION FROM THE GULF OF MEXICO. AS A RESULT...POCKETS OF LGT
PRECIPITATION...MAINLY SNOW...ARE FCST FOR SUN IN THE VICINITY OF
THE FRONT. ACCUMULATIONS LESS THAN AN INCH...PARTICULARLY WITH THE
LGT SNOWFALL RATES EXPECTED DUE TO WEAK LIFT.
AS THE JET LINES UP N OF THE CWA SUN NIGHT AND MON...THE NEARLY
STATIONARY SFC FRONT BECOMES ESTABLISHED S OF THE CWA. THIS
ALIGNMENT PUTS THE CWA IN THE CONVERGENT ZONE...WITH MID LEVEL FRONTOGENESIS
ENHANCING LIFT. THIS SETUP WOULD PRODUCE AN EXTENDED PERIOD OF
SNOW LATE SUN NIGHT INTO MON NIGHT.
HWO UPDATED TO INCLUDE 8 INCH OR MORE POTENTIAL.
THE POSITION OF THE FRONT WOULD BRING IN N TO NE WINDS THROUGH THE
EVENT...FEEDING THE COLD AIR. A BLEND OF THE PURE GFS AND ECMWF
MODEL DATA GIVES TEENS TO LOWER 20S FOR HIGHS MON...AND TEMPS FROM
ZERO INTO THE LOWER TEENS MON NIGHT. THIS DATA WAS ACCEPTED FOR
THE FCST WITH THE EXPECTATION THAT GUIDANCE LIKELY INFLUENCED BY
CLIMATOLOGY.
ANY DEVIATION TO THIS TRACK COULD LEAD TO SIGNIFICANTLY LESS
PRECIPITATION IF THE CONVERGENCE ZONE SETS UP S...OR TO MORE RAIN
AND/OR ICY MIX IF IT SETS UP FURTHER N.
THE CANADIAN HI THEN SETS UP OVER THE AREA THROUGH AT LEAST
WED...KEEPING THE CWA DRY. TEMPS BELOW CLIMATOLOGY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE OVER THE GREAT LAKES BUILDS EAST THROUGH FRIDAY WITH
GRADUALLY DIMINISHING WINDS AND VFR CONDITIONS.
STRONGEST W-NW WINDS WITH GUSTS TO AROUND 30 KT WILL BE OVER THE
NEXT COUPLE OF HOURS...AND THEN GRADUALLY FALL OFF THROUGH
DAYBREAK.
.OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY...
.FRI NIGHT...VFR WITH LIGHT WINDS.
.SAT-SAT NIGHT...MAINLY VFR WITH POSSIBLE MVFR OR LOWER DEVELOPING
LATE SAT AFTERNOON OR SAT NIGHT IN LIGHT PRECIPITATION. LIGHT SW
FLOW.
.SUN...MVFR OR LOWER WITH LIGHT SNOW POSSIBLE.
.SUN NIGHT-MON-NIGHT...IFR OR LOWER POSSIBLE IN SNOW. WINTRY MIX
POSSIBLE AT THE COASTS.
.TUE...SUB VFR IN SNOW POSSIBLY IMPROVING TO VFR AS THE DAY
PROGRESSES.
&&
.MARINE...
WIND GUSTS OVER THE NON-OCEAN ZONES HAVE FALLEN TO SCA LEVELS...SO
HAVE CANCELLED THE GALE WARNING THERE AND REPLACED WITH AN SCA
FOR THE REMAINDER OF THE OVERNIGHT.
GALE CONDITIONS GRADUALLY SUBSIDE TO SCA FROM W TO E OVERNIGHT.
WILL NEED TO PUT UP ON SCA ON AT LEAST THE EASTERN 2 OCEAN ZONES
TO REPLACE THE GALES AS SEAS WILL BE SLOW TO SUBSIDE.
LIGHT TO MODERATE FREEZING SPRAY FOR THIS EVENING ON THE OCEAN
WATERS AND EASTERN LI SOUND WATERS DUE TO THE STRONG WINDS AND
HIGHS SEAS.
ADDITIONALLY...LOW WATER ADVISORY CONTINUES FOR TONIGHT THROUGH
EARLY FRIDAY MORNING.
HIGH PRESSURE BUILDS OVER THE WATERS FRIDAY INTO FRIDAY NIGHT.
SCA CONDITIONS FRI MORNING...PARTICULARLY EASTERN OCEAN
WATERS...WILL SUBSIDE BY AFTERNOON. TRANQUIL CONDITIONS LATE
FRIDAY THROUGH FRIDAY NIGHT.
WINDS AND SEAS BELOW SCA LEVELS OVER THE WEEKEND...THEN NE WINDS
INCREASE SUN NIGHT WITH AT LEAST SCA LEVEL WINDS MON INTO TUE ON
N TO NE FLOW. GALES POSSIBLE...ESPECIALLY ON THE OCEAN. CONDITIONS
SUBSIDE ON WED WITH HI PRES BUILDING OVER THE WATERS.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIP EXPECTED THROUGH SUNDAY.
THE NEXT CHANCE FOR SIGNIFICANT LIQUID EQUIVALENT QPF EXISTS FROM
SUNDAY NIGHT-MONDAY NIGHT. AROUND AN INCH OF LIQUID EQUIVALENT IS
POSSIBLE DURING THIS TIME.
&&
.TIDES/COASTAL FLOODING...
WITH STRONG WNW FLOW AND ASTRONOMICALLY LOW TIDES TONIGHT INTO
EARLY FRIDAY MORNING...WILL CONTINUE WITH A LOW WATER ADVISORY FOR
THE TIMES OF LOW TIDE TONIGHT AS TIDAL DEPARTURES WILL BE AROUND 2
TO 2 1/2 FT BELOW MLLW.
&&
.CLIMATE...
HERE ARE THE RECORD LOW TEMPERATURES AND FORECASTED LOW
TEMPERATURES FOR FRIDAY...FEBRUARY 28 AND SATURDAY MARCH 1...AND
THE RECORD LOW MAXIMUM TEMPERATURES AND FORECASTED HIGH
TEMPERATURES FOR FRIDAY AS WELL.
FRIDAY
LOW TEMPERATURE
SITE........RECORD/YEAR SET...FORECAST LOW
NEWARK..........0/1934............3
BRIDGEPORT.....10/1950............6
CENTRAL PARK....5/1934............6
LAGUARDIA......14/1994............7
KENNEDY........15/1950............7
ISLIP..........13/1994............8
HIGH TEMPERATURE
SITE........RECORD LOW MAX/YEAR SET...FORECAST HIGH
NEWARK............24/1934.................18
BRIDGEPORT........27/1980.................19
CENTRAL PARK......21/1875.................18
LAGUARDIA.........29/2008.................20
KENNEDY...........30/1980,2008............19
ISLIP.............28/1994,2008............19
SATURDAY
SITE........RECORD LOW/YEAR SET...FORECAST LOW
NEWARK..........7/1980............13
BRIDGEPORT......6/1980............9
CENTRAL PARK....5/1884............16
LAGUARDIA.......9/1980............18
KENNEDY.........8/1980............14
ISLIP..........14/1994............8
&&
.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER THAT SERVES THE NEW YORK CITY
METROPOLITAN AREA REMAINS OUT OF SERVICE DUE TO RADIO FREQUENCY
INTERFERENCE WITH THE U.S COAST GUARD TRANSMITTER.
FOR MORE INFORMATION SEE THE FOLLOWING PUBLIC INFORMATION
STATEMENT (ALL LOWER CASE):
WWW.ERH.NOAA.GOV/OKX/PRODUCTS/STATIC.TXT
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...LOW WATER ADVISORY UNTIL 2 AM EST FRIDAY FOR ANZ338-345-350-
353-355.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ330-335-338-
340-345.
LOW WATER ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ330-335-340.
FREEZING SPRAY ADVISORY UNTIL 9 AM EST FRIDAY FOR ANZ330-350-
353-355.
GALE WARNING UNTIL 6 AM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JMC/NV
NEAR TERM...MALOIT/JC/NV
SHORT TERM...NV
LONG TERM...JMC
AVIATION...DW
MARINE...MALOIT/NV/JMC
HYDROLOGY...NV/JMC
TIDES/COASTAL FLOODING...
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TOPEKA KS
355 AM CST Fri Feb 28 2014
.SHORT TERM...(Today and Tonight)
Issued at 355 AM CST FRI FEB 28 2014
Latest water vapor satellite loop at 08Z shows a compact
shortwave trough over southeast Colorado into the Texas Panhandle.
Regional radar showing precipitation breaking out from southern
Kansas south into Oklahoma. 00Z TOP and area soundings show quite
a bit of dry air in place. Initial precipitation will go into
moistening the column and forecast soundings from the RUC and NAM
suggest that this should start to occur between 12Z and 15Z when
precipitation should start making it to the ground. Initially
cooling to the wet bulb would give sleet at first then
transitioning over to all rain after 15Z, so not expecting much
ice accumulation this morning. Models are indicating good warm
advection today ahead of the arctic front which was just moving
into western North Dakota and Montana at 09Z. Mixing from 875 mb
today and factoring cloud cover will go lower than MOS temps with
highs in the lower to middle 40s.
Tonight the cold front will move south across the CWA with
temperatures falling back into the teens north to the middle 20s
southeast of Interstate 35. Chances of light rain will continue
early this evening as additional lift is expected as additional
shortwave energy moves through and also some low level frontogenetic
forcing along the cold front. precipitation still looks to be all
rain before ending early this evening, could not rule out a mix
along the Kansas and Nebraska border though.
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CST FRI FEB 28 2014
Rapid pressure rises underway in eastern Montana this morning with
surface temps near -30 F in central Manitoba and Saskatchewan with
water vapor showing northerlies over it. To the west, rather potent
upper low making eastward progress toward California with one
stronger embedded wave nearing the coast at 08Z. Although modifying
with time, these features come together over the Central Plains this
weekend for a potential winter storm.
Overall setup hasn`t changed a lot, but model differences remain
rather large in smaller scale features, leaving confidence much
lower than that in the days preceding the heavy snow event of early
this month. Differences throughout the troposphere in temperature
and moisture profiles as well as upper energy moving through, the
location and duration of frontogenesis, and the sharpness and
intensity of the warm nose lead the list of potential pitfalls to
how this storm plays out. 0Z models range from the slow NAM to the
fast ECMWF with GEM and GFS in between. The NAM and GFS are more
robust with the aforementioned lead wave passing just north Saturday
evening and then slower with the larger scale wave Sunday, with the
GEM and ECMWF opposing these ideas.
Still looking like much of Saturday will be spent moistening the mid
levels, but by late morning low level isentropic lift may be enough
for freezing drizzle and flurries to be generated. Chances for
measurable amounts increase quickly late in the day, though the NAM
and GFS would suggest a break overnight behind the lead wave. In
either event, fast mid level flow will bring the potential for
longer lived frontogenetic bands under CSI or perhaps brief CI in
the snow growth zone. Upper lift then picks up for much of Sunday as
the main wave passes. Didn`t alter precipitation types much given
uncertainty in the details of the warm nose and how saturated it may
be for at least early in the event. This still keeps the heavier
snow in the northern to central portions of the area with moderate
ice accumulations from freezing rain in the south, and periods of
sleet for most locations. Still not looking like a major ice event
in the very cold low levels and 850 mb front staying well south.
Overall trends suggested a bit stronger wind speeds and colder
temps, giving some concern for blowing snow and hazardous wind chills
as well. Actual air temps should fall to around record levels for both
highs and lows into Monday.
Zonal flow takes hold for the remainder of the forecast resulting in
moderating temps. Some decent agreement with a longer wavelength
trough passing around Wednesday though moisture values likely quite
limited for only light precip opportunities.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1137 PM CST THU FEB 27 2014
Look for VFR conds to become MVFR by afternoon as moisture streams north
ahead of the disturbance now moving into the TX Panhandle. There
could also be sct -shra but coverage remains in question at the
TAF sites. Next issue becomes when CIGS drop to below 2kft as
another cold front pushes south through the area after 00z Sat.
There could also be patchy drizzle or freezing drizzle after 00z
Sat but confidence is low.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Saturday evening through late Sunday
night FOR KSZ008>012-020>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...53
LONG TERM...65
AVIATION...Omitt
AREA FORECAST DISCUSSION
NWS BILLINGS MT
930 PM MST THU FEB 27 2014
.UPDATE...
PERIOD OF RAIN IN THE BILLINGS AREA IS JUST ABOUT OVER AS COLD AIR
IS NOW SURGING IN FROM THE NORTH...WITH STRONG PRESSURE RISES
ACROSS NORTH CENTRAL MT AND TEMPS AT JUDITH GAP ALREADY IN THE LOW
20S WITH WIND GUSTS TO 40 MPH. EXTENDED PERIOD OF ISENTROPIC
ASCENT OVERRUNNING THE LOW LEVEL COLD AIR WILL BRING SNOWFALL
ACROSS MUCH OF OUR WEST/CENTRAL PARTS TONIGHT AND FRIDAY... THEN
CONTINUING FRIDAY NIGHT AND SATURDAY AS SUBTROPICAL ENERGY/
MOISTURE GLANCES OUR CWA FROM THE SW.
HAVE MADE THE FOLLOWING ADJUSTMENTS TONIGHT. RAIN/SNOW MIX IN THE
EVENING WILL BE JUST SNOW AFTER 06Z. THIS SLIGHTLY LONGER PERIOD
OF RAIN THAN EXPECTED MAY REDUCE SNOW AMTS TONIGHT A BIT...BUT
STILL LOOKING FOR 2-4 INCHES FOR LOWER ELEVATIONS AS THE DENDRITIC
LAYER DEEPENS SUBSTANTIALLY THUS ALLOWING FOR SNOWFALL TO BE
EFFICIENT AND PERIODICALLY HEAVY. NEXT ADJUSTMENT WAS TO LOWER RED
LODGE/NYE FOOTHILLS SNOW AMOUNTS BY A FEW INCHES TONIGHT AND
FRIDAY. LOOKS LIKE A SHORT PERIOD OF ENHANCED UPSLOPE AS THE
FRONT COMES IN TONIGHT...BUT THEN AS MID LEVEL WINDS BACK THE
STRONGEST FORCING SHOULD SHIFT AWAY FROM THE BEARTOOTH SLOPES AS
THERE WILL BE SOME DEGREE OF DOWNSLOPING...AS SHOWN CONSISTENTLY
BY THE RAP...LATER TONIGHT AND FRIDAY. BEST ASCENT FOR THE
FOOTHILLS WILL BE FRIDAY NIGHT INTO SATURDAY AS ENERGY FROM THE SW
PROVIDES BETTER UPSLOPE POTENTIAL AND MORE MOISTURE. THIRDLY...
HAVE ISSUED A WIND CHILL ADVISORY FOR FALLEN COUNTY TOMORROW THRU
SATURDAY PER GUSTY NW WINDS AND VERY COLD TEMPS. THIS WILL BE AN
EXTENDED PERIOD OF COLD WIND CHILLS ACROSS OUR EAST.
BE CAREFUL IF YOU ARE TRAVELING THIS EVENING AS WET ROADS WILL BE
ICING OVER SOON.
JKL
&&
.SHORT TERM...VALID FOR FRI AND SAT...
INGREDIENTS CONTINUE TO COME TOGETHER FOR A DANGEROUS WINTER
STORM TONIGHT THROUGH SAT NIGHT. AT 21Z...ARCTIC FRONT WAS SURGING
S THROUGH SOUTHERN ALBERTA. MOISTURE MOVING INTO THE AREA FROM W
MT WAS GENERATING LIGHT SHOWERS OVER AREAS W AND N OF KBIL PER
RADAR IMAGERY AND OBSERVATIONS. MODELS WERE IN GOOD AGREEMENT IN
BRINGING THE FRONT INTO THE AREA EARLY THIS EVENING AND SLIDING IT
S THROUGH THE AREA TONIGHT. A BAND OF STRONG FRONTOGENESIS WILL
ACCOMPANY THE FRONT AND ISENTROPIC LIFT WILL DEVELOP OVER THE
WESTERN ZONES. SNOW WILL OVERSPREAD THE AREA FROM W TO E TONIGHT.
NOTED THE HRRR AND SREF HINTED AT SOME POSSIBLE FREEZING RAIN
EARLY IN THE EVENING BEFORE A CHANGEOVER TO SNOW...BUT RAP
SOUNDINGS SHOWED A QUICK WET BULB DOWN ONCE THE PRECIPITATION
BEGINS SO WILL NOT INCLUDE IT IN THE FORECAST AT THIS TIME. ALSO
SOUNDINGS SUPPORTED ICE DEVELOPMENT IN THE CLOUDS SO RESULT SHOULD
BE A RATHER QUICK CHANGEOVER TO SNOW THIS EVENING. GOOD DENDRITIC
GROWTH WILL ACCOMPANY THE LIFT AND MOISTURE RESULTING IN SEVERAL
INCHES OF SNOW ACCUMULATION OVERNIGHT WEST OF ROSEBUD COUNTY. IT
WILL BECOME WINDY OVERNIGHT DUE TO THE FRONTAL PASSAGE AND AREAS
LIKE JUDITH GAP AND KLVM COULD SEE NEAR WHITEOUT CONDITIONS.
TEMPERATURES BY FRI MORNING WILL BE IN THE SINGLE DIGITS ABOVE AND
BELOW ZERO.
STRONG ISENTROPIC LIFT WILL OVERSPREAD THE REGION FRIDAY AND
CONTINUE THROUGH SAT...BEFORE DIMINISHING SAT NIGHT. SHORTWAVE
ENERGY PASSING BY TO THE S OF THE AREA WILL AID IN GENERATING
THE ISENTROPIC LIFT. THE FRONTOGENESIS BAND WILL BE ALONG THE
MOUNTAINS AND FOOTHILLS ON FRI AND WILL MOVE S OF THE AREA FRI
NIGHT. STRONG JET DIVERGENCE WILL AID THE LIFT OVER THE AREA FRI
INTO SAT AS WELL. EXPECT AREAS OF BLOWING SNOW OVER THE REGION ON
FRI DUE TO WINDY CONDITIONS. THE BEST DENDRITIC GROWTH WILL SINK S
AND SW DURING THE DAY ON FRI AND WILL BE OVER THE FAR SW FRI NIGHT
AND SAT. SEVERAL INCHES OF SNOW WILL CONTINUE W OF ROSEBUD COUNTY
ON FRI WITH HIGHER ACCUMULATIONS IN THE MOUNTAINS. FRI NIGHT AND
SAT WILL HAVE SIMILAR ACCUMULATIONS. WINDS WILL BE LOWER FOR FRI
NIGHT AND SAT WITH LESS OF A THREAT OF BLOWING SNOW. SNOW WILL
WIND DOWN SAT NIGHT AS LIFT DECREASES OVER THE AREA.
HIGHS WILL BE IN THE SINGLE DIGITS AND TEENS ON FRI AND LOWS WILL
BE IN THE TEENS BELOW ZERO FRI NIGHT. TEMPERATURES WILL NOT RISE
ABOVE ZERO FOR SAT AND WILL BE VERY COLD SAT NIGHT AS 850 MB
TEMPERATURES APPROACH -30 DEGREES C. EXPECT DANGEROUS WIND CHILLS
ACROSS THE AREA FROM FRI ONWARD.
WILL CONTINUE THE WARNING FOR AREAS W OF ROSEBUD COUNTY FOR
MULTIPLE STORM IMPACTS...AND WILL ISSUE AN ADVISORY FOR THE
EASTERN ZONES...EXCEPT FOR FALLON COUNTY WHERE SNOW AMOUNTS WILL
BE LIGHT. ARTHUR
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
BITTERLY COLD TEMPERATURES AND WIND CHILLS WILL CONTINUE SUNDAY
INTO MONDAY BEFORE A MODERATION IN TEMPERATURES ARRIVES TUESDAY.
MODELS ARE IN FAIRLY GOOD AGREEMENT IN KEEPING A 500MB UPPER LOW
AND ASSOCIATED VORTICITY AREA OVER BRITISH COLUMBIA SUNDAY AND
MONDAY. THIS WILL RESULT IN AN UPPER LEVEL FLOW FROM THE
WEST/NORTHWEST KEEPING A MOIST PACIFIC FLOW ACROSS THE FORECAST
AREA. AT THE SURFACE...A STRONG BAROCLINIC ZONE WILL BE SITUATED
ACROSS THE ENTIRE EASTERN SLOPES OF THE ROCKY MOUNTAINS. ALTHOUGH
THE STRONG DYNAMICS FROM THIS CURRENT STORM WILL MAINLY BE OUT OF
THE AREA THERE WILL STILL BE CHANCES FOR SNOW SHOWERS BOTH DAYS.
TEMPERATURES WILL REMAIN BELOW ZERO DURING THE DAY SUNDAY BUT A
SLIGHT MODERATION WILL BE POSSIBLE MONDAY.
MODELS TRY TO QUICKLY RETREAT THE ARCTIC AIR BY TUESDAY WITH
READINGS WELL UP INTO THE 40S. HOWEVER...GIVEN EXPECTED SNOW COVER
WILL KEEP READINGS IN THE 20S AND 30S ACROSS THE AREA. HIGH
TEMPERATURES THIS TIME OF YEAR CAN BE DIFFICULT...ESPECIALLY WITH
SNOW COVER...AS STRONG EARLY MARCH SUN ANGLE CAN QUICKLY BOOST
TEMPERATURES FOR A FEW HOURS. IN ADDITION... WILL NEED TO WATCH
THE POSSIBILITY OF BLOWING SNOW AS SOME BRIEF GAP AND/OR DRAINAGE
WINDS MAY BE GUSTY AS THE ARCTIC RETREATS. AFTER SUNDAY...NO
STRONG STORM SYSTEM LOOKS TO IMPACT THE FORECAST AREA UNTIL NEAR
THE END OF NEXT WEEK AS MODELS BRING THE POSSIBILITY OF MORE SNOW.
HOOLEY
&&
.AVIATION...
A MIX OF RAIN AND SNOW WILL CONTINUE THIS EVENING OVER CENTRAL AND
WESTERN AREAS...EVENTUALLY TURNING TO ALL SNOW BY MIDNIGHT. SNOW
WILL SPREAD INTO EASTERN AREAS AFTER MIDNIGHT. WEST OF A ROUNDUP
TO SHERIDAN LINE SNOW WILL BECOME HEAVY AT TIMES RESULTING IN IFR
OR LOWER CONDITIONS AFTER MIDNIGHT...INCLUDING KBIL...KSHR AND
KLVM TAF LOCATIONS...WITH MVFR TO IFR CONDITIONS TO THE EAST OF
THIS LINE INCLUDING KMLS. POOR FLIGHT CONDITIONS WILL PERSIST THROUGH
THE DAY FRIDAY AND SATURDAY WITH ALL AREA MOUNTAINS OBSCURED.
CHAMBERS
&&
.PRELIMINARY POINT TEMP/POPS...
FRI SAT SUN MON TUE WED THU
-----------------------------------------------------------
BIL 008/009 912/909 917/905 916/015 007/032 015/037 023/030
++/S ++/S 73/S 33/S 23/S 32/S 22/S
LVM 010/015 908/903 914/006 912/024 013/035 017/039 027/036
++/S ++/S 74/S 43/S 33/S 42/S 33/S
HDN 007/012 913/905 919/901 918/014 002/030 013/034 020/029
++/S ++/S 73/S 33/S 22/S 32/S 22/S
MLS 002/005 915/909 920/902 919/008 000/026 011/031 017/023
56/S 77/S 52/S 22/S 12/S 22/S 22/S
4BQ 004/010 910/903 919/002 918/011 003/027 013/035 017/027
77/S 9+/S 62/S 22/S 12/S 21/B 12/S
BHK 902/002 917/908 921/901 920/005 903/022 015/031 012/022
25/S 56/S 42/S 22/S 12/S 21/B 12/S
SHR 014/015 909/901 914/005 915/019 008/035 016/039 020/035
9+/S ++/S 73/S 32/S 22/S 32/S 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST SUNDAY FOR
ZONES 28>30-34-35-38>42-56>58-63>68.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 AM MST SUNDAY FOR
ZONES 31-32-36-37.
WIND CHILL ADVISORY IN EFFECT FROM 5 AM FRIDAY TO 6 PM MST
SATURDAY FOR ZONE 33.
WY...WINTER STORM WARNING IN EFFECT UNTIL 6 AM MST SUNDAY FOR
ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
358 AM CST FRI FEB 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1136 PM CST THU FEB 27 2014
INCLUDED A PERIOD OF LOW LEVEL WIND SHEAR FOR KGRI THROUGH THE
NIGHT AS WINDS ALOFT RAPIDLY INCREASE TO AROUND 45KTS. A COLD
FRONTAL BOUNDARY WILL CROSS THER TERMINAL FRIDAY AFTERNOON WITH
WINDS SHIFTING NORTH BEHIND THE FRONT WITH GUSTS AROUND 25KTS
POSSIBLE. CIGS ALSO LOWER BEHIND THE BOUNDARY AND LIGHT
SNOW/FLURRIES ARE POSSIBLE LATE FRIDAY AFTN INTO FRIDAY EVENING.
HAVE KEPT CIGS AT MVFR FOLLOWING FROPA.
&&
.CLIMATE...
ISSUED AT 430 PM CST THU FEB 27 2014
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY
RECORDS...ITS NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY
COULD COME VERY CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON
RECORD FOR ANY DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...FAY
CLIMATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
118 AM EST FRI FEB 28 2014
.SYNOPSIS...
ARCTIC AIR WILL SPREAD OVER PENNSYLVANIA TONIGHT WITH BITTERLY
COLD WIND CHILLS IN STORE. SOME MODERATION IN TEMPERATURES IS
EXPECTED ON SATURDAY AS HIGH PRESSURE MOVES EAST OF THE
REGION. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SATURDAY
NIGHT AND PRODUCE LIGHT SNOW. A WIDE-REACHING STORM SYSTEM WILL
THEN MOVE IN QUICKLY FROM THE OHIO AND TENNESSEE VALLEYS. THE
STORM WILL SLIDE ALONG THE OLD FRONT WHICH WILL BE LAID OUT TO OUR
SOUTH. IT WILL MAKE AN IMPACT ON ALL OF PA LATE SUNDAY THROUGH ALL
OF MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS THE
REGION SUNDAY INTO MONDAY. FAIR AND CONTINUED COLD WEATHER WILL
FOLLOW FOR THE REST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
10 AM UPDATE...
WINDS ARE SLACKENING AND TEMPS COOLING AS ANTICIPATED. WIND CHILL
ADVY LOOKING ON TRACK. SKIES HAVE CLEARED OTHER THAN A COUPLE OF
CLOUDS ACROSS THE NRN TIER WHICH AREA TOUGH TO PICK UP ON IR
CHANNELS - EVEN THE 11-3.9 MICRON IMAGERY - SINCE GROUND/SNOW
COVER IS JUST AS COLD AS THE CLOUDS.
7 PM UPDATE...
MINOR TWEAKS TO NEAR TERM TEMPS/WINDS. WIND CHILLS ARE CLOSE TO
WARNING FOR THE NC MTS. TEMPS AT THE CLOSEST NY SITES AND BFD ARE
ALL ALREADY 0F. MAY END UP PUTTING WARNING UP FOR A FEW COS
THERE...BUT MESO MDLS STILL TRY TO SLACKEN THE WINDS ENOUGH TO
KEEP THEM JUST ABOVE -25.
PREV...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG
A SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
28/06Z...VFR/CLR SKIES UNDER SFC HIGH PRES WILL PREVAIL THRU MOST
OF THE PERIOD...WITH JUST A GRADUAL UPTICK IN HIGH CLOUDS STARTING
TO INVADE FM THE WEST BY 06Z SAT. NW WINDS WILL CONTINUE TO DECREASE
BCMG LGT/VRB IN MOST PLACES BY 12Z...THEN VEERING TO THE EAST BUT
REMAINING AOB 5KTS.
HIGH PRES WILL SHIFT NEWD ON SAT...AS UPPER-LEVEL ENERGY PIVOTING
AROUND POLAR VORTEX OVER HUDSON BAY SENDS A WEAK SFC LOW EWD ALONG
THE US/CANADIAN BORDER..FROM THE UPPER GRT LKS INTO NRN NEW ENG
THIS WKEND. THE TRAILING ARCTIC FRONT SINKING SWD FROM THE MIDWEST
AND SETTLING W-E ACRS THE OHIO VALLEY/MID-ATL STATES WILL BE A
FOCUS FOR WINTRY PCPN ESP LATER SUN INTO MON..AS WAVES OF LOW
PRES EJECT NEWD FROM THE ARKLATEX THRU THE TN VLY AND EXIT THE
EAST COAST OVER VA AND THE CAROLINAS. THE N-S PLACEMENT OF THE
ARCTIC BNDRY WILL PLAY A CRUCIAL ROLE IN DETERMINING PTYPES WITH
WITH A MESSY/ICY TRANSITION ZONE EXPECTED NEAR THE FRONT. HIGH
PRES MIGRATING EWD FM THE GRT LKS SHOULD BRING IMPROVG CONDS INTO
TUES.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT WITH -SN DVLPG NW.
SUN-MON...MVFR/IFR VIS AND CIGS LKLY IN SN AND/OR MIXED PCPN.
TUE...VFR NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ004>006-010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1140 PM EST THU FEB 27 2014
.SYNOPSIS...
ARCTIC AIR WILL SPREAD OVER PENNSYLVANIA TONIGHT WITH BITTERLY
COLD WIND CHILLS IN STORE. SOME MODERATION IN TEMPERATURES IS
EXPECTED ON SATURDAY AS HIGH PRESSURE MOVES EAST OF THE
REGION. A COLD FRONT WILL APPROACH FROM THE NORTHWEST ON SATURDAY
NIGHT AND PRODUCE LIGHT SNOW. A WIDE-REACHING STORM SYSTEM WILL
THEN MOVE IN QUICKLY FROM THE OHIO AND TENNESSEE VALLEYS. THE
STORM WILL SLIDE ALONG THE OLD FRONT WHICH WILL BE LAID OUT TO OUR
SOUTH. IT WILL MAKE AN IMPACT ON ALL OF PA LATE SUNDAY THROUGH ALL
OF MONDAY. SIGNIFICANT WINTRY PRECIPITATION IS EXPECTED ACROSS THE
REGION SUNDAY INTO MONDAY. FAIR AND CONTINUED COLD WEATHER WILL
FOLLOW FOR THE REST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
10 AM UPDATE...
WINDS ARE SLACKENING AND TEMPS COOLING AS ANTICIPATED. WIND CHILL
ADVY LOOKING ON TRACK. SKIES HAVE CLEARED OTHER THAN A COUPLE OF
CLOUDS ACROSS THE NRN TIER WHICH AREA TOUGH TO PICK UP ON IR
CHANNELS - EVEN THE 11-3.9 MICRON IMAGERY - SINCE GROUND/SNOW
COVER IS JUST AS COLD AS THE CLOUDS.
7 PM UPDATE...
MINOR TWEAKS TO NEAR TERM TEMPS/WINDS. WIND CHILLS ARE CLOSE TO
WARNING FOR THE NC MTS. TEMPS AT THE CLOSEST NY SITES AND BFD ARE
ALL ALREADY 0F. MAY END UP PUTTING WARNING UP FOR A FEW COS
THERE...BUT MESO MDLS STILL TRY TO SLACKEN THE WINDS ENOUGH TO
KEEP THEM JUST ABOVE -25.
PREV...
MOST INTENSE/ORGANIZED SNOW SQUALL ACTIVITY HAS RAPIDLY LIFTED
INTO THE POCONO PLATEAU AND TOWARD THE CATSKILLS REGION NY BY MID
AFTERNOON...BUT NUMEROUS SNOW SHOWERS WITH BRIEF SNOW BURSTS
CONTINUE ACROSS CENTRAL PA THANKS TO STEEP LOW LEVEL LAPSE RATES
AND SFC BASED CAPES UP TO 200 J/KG. RUC13 AND NAM12 DIAGNOSTICS
INDICATE RAPID DISSIPATION OF SNOW SHOWERS THROUGH 21/22Z FOLLOWED
BY CLEARING FOR MUCH OF CENTRAL AND SOUTH CENTRAL PA AS HIGH
PRESSURE BUILDS IN FROM THE OHIO VALLEY. LAKE CLOUDS SHOULD HANG
INTO EARLY FRIDAY MORNING ACROSS THE NORTH AND ESPECIALLY NORTHWEST.
MAIN CONCERN TONIGHT IS FOR DANGEROUS WIND CHILLS...AS STRONG
WINDS COMBINE WITH FALLING TEMPS DURING THIS AFTERNOON AND
EVENING. GOING WIND CHILL ADVISORY IN GOOD SHAPE TONIGHT INTO
TOMORROW. BUFKIT SOUNDINGS SUPPORT GUSTS UP TO 40KTS.
MIN TEMPS TONIGHT WILL DROP WELL BELOW ZERO UP NORTH...WITH -10F
TO -15F EXPECTED. SINGLE DIGITS BELOW ZERO WILL AFFECT THE LAUREL
HIGHLANDS...CENTRAL MOUNTAINS...ENDLESS MOUNTAINS AND LYCOMING
VALLEY...ZERO TO 5 ABOVE ELSEWHERE ACROSS SOUTH CENTRAL MOUNTAINS
AND LOWER SUSQ. EXTREMELY COLD FOR THIS TIME OF YEAR...BUT NO
RECORD LOWS EXPECTED DUE TO A FRIGID MORNING BACK IN 1934.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
ARCTIC SFC HIGH PRESSURE WILL REMAIN THE MAIN PLAYER FRIDAY AND
FRIDAY NIGHT FOR PA...WITH THE SFC HIGH MOVING WELL OFFSHORE BY
SATURDAY MORNING INTRODUCING A BRIEF MODERATING SPELL FOR SATURDAY.
MOSTLY SUNNY SKIES WITH LIGHT SFC WINDS ARE EXPECTED ON SATURDAY...
WHICH WILL BE MUCH MORE TOLERABLE TO FRIDAY CONDITIONS.
ENSEMBLE MEAN 925TEMPS OF ARND -15C WILL SUPPORT MAX TEMPS NO
BETTER THAN THE TEENS TO NR 20F...ARND 25F BELOW NORMAL FOR LATE
FEBRUARY.
FRIDAY NIGHT SHOULD REMAIN DRY...BUT WITH SOME INCREASING HIGH
CLOUDS LATE IN THE RETURN FLOW AROUND THE DEPARTING OFFSHORE SFC
HIGH. RESULTING MIN TEMPS WILL BE SOME 15 TO AS MUCH AS 20F WARMER
SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
ON SAT...STORM OF INTEREST FOR LATE WEEKEND/EARLY NEXT WEEK WILL
BEGIN WORKING ITS WAY FROM THE CALIF COAST EASTWARD. OVER PA...
FAST AND NEARLY ZONAL FLOW ALOFT AS SPOKES OF COLDER AIR ROTATING
AROUND A LOW ANCHORED NEAR HUDSON BAY GET SHUNTED TO OUR NORTH.
ONE NOTABLE SHORTWAVE SLIDING EASTWARD ACROSS S CANADA WILL DRAG
A SURFACE COLD FRONT THROUGH PA SAT NIGHT. AHEAD OF THAT...SOME
MILDER AIR WILL WORK INTO THE STATE ALONG WITH PLENTY OF CLOUDS.
A BIT OF LIGHT SNOW ALSO POSS...EMPHASIS ON LIGHT AS QPF AT BEST
IS JUST A FEW HUNDREDTHS...AND CONFINED TO THE NW MTNS AS SW FLOW
OVERRUNS RETREATING ARCTIC AIR MASS.
NORTHERN STREAM SHORTWAVE PASSING N OF THE GRT LKS WILL PUSH A
DYING COLD FRONT THRU CENTRAL PA SAT NIGHT. SCT LIGHT SNOW MAY
ACCOMPANY PASSAGE OF THIS FRONT MAINLY OVR THE N MTNS...WHILE AIR
MASS ACTUALLY BECOMES MILD ENOUGH FOR EITHER -SHRA OR -SHSN OVER
SOUTH. QPF AGAIN REMAINS LIGHT...A TENTH OF AN INCH OR LESS AT
BEST ALONG NY BORDER. ERODING FRONTAL BOUNDARY BECOMES STATIONARY
NEAR THE MASON DIXON LINE...ALLOWING MILDER AIR TO REMAIN IN PLACE
SOUTH OF IT ACROSS PORTIONS OF S PA...WITH READINGS ONLY FALLING
TO ARND 32F IN THE LOWER SUSQ.
REMNANTS OF THIS OLD FRONTAL BOUNDARY COMBINED WITH SOUTHERN
STREAM ENERGY WILL BECOME THE FOCUS FOR MID RANGE. MODEL GUIDANCE
IN QUITE GOOD AGREEMENT ON A SOUTHERN STREAM DISTURBANCE LIFTING
TOWARD PA LATE IN THE WEEKEND. CONFIDENCE CONTINUES TO INCREASE IN
A SIGNIFICANT BOUT OF WINTRY PRECIP FOR MUCH OF CENTRAL PA LATER
SUNDAY INTO MONDAY...AS PLUME OF GULF OF MEX MOISTURE OVERRUNS A
QUASI-STATIONARY BNDRY JUST S OF THE MASON DIXON. BOTH GEFS AND
OPER EC/CMC CONTINUE TO SUGGEST THERE WILL BE A NARROW SWATH OF
GREATER THAN AN INCH PRECIP ACROSS CENTRAL OR SOUTHERN PA...MAYBE
SLIDING JUST A BIT FURTHER SOUTH THAN PREV RUNS. BEST CHC FOR
SIGNIFICANT SNOW APPEARS TO BE ACROSS CENTRAL/PARTS OF NORTHERN
PA...WITH A GREATER CHC OF A WINTRY MIX OR EVEN A PERIOD OF RAIN
IN THE SOUTH /AND MUCH LOWER SNOW ACCUMS/...BEFORE COLDER AIR
AT LOWER LEVELS BEGINS TO SLIDE IN FROM THE NORTH TOWARD THE END
OF THE EVENT BRINGING BETTER CHANCES FOR PRECIP TO END AS A PERIOD
OF SNOW ON MONDAY.
MIDWEEK WILL BRING FAIR AND COLD WX /AROUND 15F BELOW NORMAL ALONG
WITH MORNING LOWS BACK INTO SINGLE DIGITS/ AS LARGE SFC HIGH PRES
SYSTEM BUILDS SE TOWARDS PA FROM CENTRAL CANADA. LATE WEEK LOOKS
TO BRING A BIT OF RELIEF FROM THE VERY CHILLY WEATHER AS COLDER
AIR RETREATS BACK TO THE NORTH AS WARMER SOUTHWEST FLOW HELPS TO
NUDGE TEMPS BACK TOWARD...YET STILL SLIGHTLY BELOW...NORMAL.
HEADING INTO NEXT WEEKEND...GFS/ECMWF SUGGESTING ANOTHER SOUTHERN
STREAM WAVE PROGGED TO IMPACT MAINLY SOUTHEAST STATES BEFORE
SLIDING OFF CAROLINA COAST.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
WINDS ON THE DECREASE NOW...AND SKIES MAINLY CLEAR.
03Z TAFS SENT.
EARLIER DISCUSSION BELOW.
AS EXPECTED...RATHER ACTIVE SNOW SHOWERS MADE IT INTO THE LOWER
SUSQUEHANNA VALLEY THIS AFT...JUST TOOK A LITTLE LONGER TO GET
THERE.
MOST OF THE SNOW IS OVER NOW...BUT SOME SNOW SHOWERS WILL LINGER
AT BFD AND JST OVERNIGHT.
WINDS VERY GUSTY STILL...WILL LINGER FOR SEVERAL MORE HOURS.
EXPECT A DECENT DAY ON FRIDAY...WITH LOTS OF SUN...AS HIGH
PRESSURE BUILDS INTO THE AREA. WINDS WILL BE LIGHTER. THE
BIG ISSUE WILL BE VERY LOW TEMPS FOR LATE FEB.
FRONT STALLS NEARBY LATER THIS WEEKEND. MIXED PRECIPITATION
LIKELY LATER IN THE WEEKEND INTO MONDAY...AS AT LEAST ONE
WEAK LOW LIFTS NE ALONG THE FRONT.
OUTLOOK...
SAT...VFR TRENDING LOWER INTO SAT NGT IN -SN.
SUN-MON...MVFR/IFR LKLY IN SN AND/OR MIXED PCPN.
TUE...MVFR POSS NW...VFR ELSEWHERE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ004>006-
010>012-017-018-024-033-037-041-042.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/RXR
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
530 AM MST FRI FEB 28 2014
.UPDATE...
UPDATED AVIATION AND FIRE WEATHER SECTIONS.
&&
.SYNOPSIS...
A WELL DEFINED PACIFIC STORM SYSTEM WILL ARRIVE TODAY WITH
WIDESPREAD SHOWERS BEGINNING IN SOUTHEAST CALIFORNIA DURING THE
MORNING...THEN SPREADING INTO ARIZONA THROUGH THE AFTERNOON AND
EVENING HOURS. PERIODIC RAIN SHOWERS AND EVEN A FEW THUNDERSTORMS
WILL BE POSSIBLE THROUGH THE WEEKEND. CONDITIONS WILL GRADUALLY DRY
OUT FROM WEST TO EAST SUNDAY WITH HIGH PRESSURE AND NORMAL
TEMPERATURES RETURNING EARLY NEXT WEEK.
&&
.DISCUSSION...
VERY WELL DEFINED CIRCULATION REMAINS OFFSHORE THIS MORNING AND
CONTINUES TO OCCLUDE AS OF 09Z. HOWEVER...PRECIPITATION IS ALREADY
FALLING WEST OF THE COASTAL MOUNTAINS AS A SUBSTANTIAL ATMOSPHERIC
RIVER WITHIN THE WARM CONVEYOR BELT MOVES ONSHORE. THE NEARLY
PERPENDICULAR UPSLOPE COMPONENT TO THE 700-850MB WINDS IS CERTAINLY
HELPING MATTERS AS WELL WITH WINDS ANALYZED AROUND 60-70KTS. WHILE
THE FORECAST AREA REMAINS DRY AT THE MOMENT...ITS SIMPLY A MATTER
OF TIME BEFORE THE BOUNDARY LAYER SATURATES SUFFICIENTLY AND
PRECIPITATION BEGINS. BLENDED TPW IMAGERY REVEALS APPROXIMATELY 0.5
INCH PWATS ACROSS THE LOWER AZ DESERTS...WITH SLIGHTLY HIGHER VALUES
ACROSS SOUTHEAST CALIFORNIA...SUBSTANTIALLY HIGHER VALUES /AROUND
1.25 INCHES/ OFF THE SAN DIEGO COAST...AND APPROXIMATELY 1.8 INCHES
A BIT FARTHER WEST. SUFFICE TO SAY THE ATMOSPHERE HAS PLENTY OF
MOISTURE TO WORK WITH...ONLY QUESTION IS HOW QUICKLY IT WILL BE
IMPORTED OVER THE COASTAL MOUNTAINS AND THE BAJA SPINE AND INTO THE
LOWER AZ DESERTS.
ALL MODEL GUIDANCE INDICATES MOISTURE WILL MAKE ITS WAY INTO
SOUTHEAST CALIFORNIA LATER THIS MORNING...NAM...HRRR...LOCAL
WRFS...AND EVEN THE MORE COARSE GUIDANCE ARE ON BOARD. WHILE A
FEW SHOWERS ARE POSSIBLE THIS MORNING AROUND EL CENTRO AND BLYTHE
AND CERTAINLY ACROSS JOSHUA TREE NATIONAL PARK...ACTIVITY SHOULD
PICK UP SUBSTANTIALLY THIS AFTERNOON AS CONVECTION DEVELOPS OVERHEAD
AND FILLS IN WITH THE INITIAL PRE-FRONTAL TROUGH. THE PRESENCE OF
RELATIVELY STEEP MID LEVEL LAPSE RATES AND A FEW HUNDRED J/KG MLCAPE
WILL ALSO HELP THINGS ALONG LATER THIS MORNING/AFTERNOON.
ARGUABLY...LATE THIS MORNING THROUGH THIS AFTERNOON COULD BE
SOUTHEAST CALIFORNIAS BUSIEST PERIOD DURING THIS ENTIRE EVENT. POPS
WERE ALREADY AT OR NEAR 100 PERCENT FOR TODAY AND I ONLY MADE VERY
MINOR ADJUSTMENTS. MAINTAINED THE MENTION OF THUNDER AS WELL...GIVEN
AFOREMENTIONED LAPSE RATES AND MLCAPES...THIS ALSO MATCHES SPCS DAY
1 GENERAL THUNDER OUTLINE...BUT I STILL THINK WIDESPREAD SEVERE
WEATHER IS UNLIKELY. HOWEVER...WINDS WILL BE A FACTOR ESPECIALLY
ACROSS THE HIGHER TERRAIN OF JOSHUA TREE NATIONAL PARK AND THE
USUALLY WINDY I-8 CORRIDOR OF IMPERIAL COUNTY. GOING WITH A WIND
ADVISORY TODAY INTO THIS EVENING BUT THE VAST MAJORITY OF AREAS
DOWNWIND OF THE COASTAL MOUNTAINS SHOULD BE SPARED THE STRONGEST
WINDS.
THE BIGGEST CHALLENGE THIS MORNING IS DECIDING WHEN PRECIP WILL
BEGIN ACROSS THE LOWER AZ DESERTS AND AROUND THE PHOENIX AREA. WHILE
TRYING NOT TO FOCUS TOO CLOSELY ON ONE OR TWO DETERMINISTIC
SOLUTIONS...ALL THE 00Z HI-RES GUIDANCE INCLUDING THE NAM12...4KM
NAM...LOCAL WRFS...NSSL WRF...HRRR...AND RAP INDICATE PRECIP WILL
HOLD OFF UNTIL WELL AFTER 00Z AROUND THE PHOENIX AREA. PER THEIR
SOLUTIONS...PRECIP WILL DEVELOP IN THE MOUNTAINS NORTH/EAST OF
PHOENIX FIRST...THEN GRADUALLY BACKFILL OVER THE METRO AS ADDITIONAL
MOISTURE IS IMPORTED INTO THE AREA. FOR BETTER OR WORSE...THIS
BACKFILLING DOESNT TAKE PLACE UNTIL CLOSER TO 12Z SATURDAY...ABOUT
12 HRS SLOWER THAN PREVIOUSLY THOUGHT. GIVEN THE VERY STRONG
ISENTROPIC LIFT THAT WILL BE OVERHEAD LATE THIS EVENING ALONG WITH
NEARLY 50KT SOUTHERLY 850MB WINDS AND PWATS AROUND 1.2-1.3
INCHES...IM NOT CONVINCED IT WILL STAY DRY ALL THE WAY THROUGH
SATURDAY MORNING. I MADE SLIGHTLY DOWNWARD ADJUSTMENTS TO POPS
ACROSS THE DESERTS FOR THIS EVENING/OVERNIGHT BUT VALUES ARE STILL
RUNNING IN THE 80-90 PERCENT RANGE. THE HIGHER TERRAIN NORTH/EAST OF
PHOENIX IS STILL AT 100 PERCENT AS THEY SHOULD BE THE FIRST TO SEE
PRECIP DEVELOPMENT.
MODELS ARE TRENDING TOWARD SLIGHTLY HIGHER VALUES OF MLCAPE DURING
THE DAY ON SATURDAY...ALONG WITH SLIGHTLY HIGHER VALUES OF 0-1KM
0-3KM AND 0-6KM SHEAR. CONFIDENCE INCREASING THAT THERE WILL INDEED
BE THUNDER AROUND DURING THE DAY ON SATURDAY...BUT WITH QUITE A BIT
OF CLOUD COVER WIDESPREAD SEVERE STILL SEEMS UNLIKELY. PERHAPS A FEW
SHOWERS THAT ARE CAPABLE OF LOCALLY GUSTY WINDS...BUT THATS ABOUT
IT. ACROSS SOUTHEAST CALIFORNIA I THINK THERE COULD BE A FEW SHOWERS
ON SATURDAY BUT ISENTROPIC DOWNGLIDE ON THE 295-310K SURFACES STARTS
BECOMING EVIDENT AS EARLY AS 12-18Z SATURDAY. ACTIVITY MAY END UP
BEING FAIRLY SCATTERED IN NATURE BUT GIVEN THE LARGE SWATH OF
MOISTURE THAT WILL STILL BE IN PLACE...HESITANT TO REDUCE POPS TOO
MUCH.
THE 1.2 INCH PWAT AXIS SHIFTS INTO THE MOUNTAINS EAST OF PHOENIX
SATURDAY EVENING AND A DRYING TREND SHOULD COMMENCE ACROSS THE
ENTIRE FORECAST AREA /EXCLUDING GILA CO/ DURING THE EVENING HOURS.
LINGERING MOISTURE WILL ALLOW FOR A FEW SHOWERS ON SUNDAY BUT THE
VAST MAJORITY OF THESE SHOWERS SHOULD BE IN THE MOUNTAINS WELL EAST
OF PHOENIX. HELD ONTO AT LEAST A SLIGHT CHANCE MENTION OF POPS
SUNDAY INTO SUNDAY AFTERNOON BUT FOR THE DESERTS...RAINFALL SHOULD
BE PRETTY MUCH OVER AND DONE WITH. WHAT DOES THIS MEAN FOR STORM
TOTAL AMOUNTS? A BLEND OF WPC PROVIDED QPF AND GFS/EUROPEAN QPF
YIELDS ABOUT 0.25 TO 0.5 INCHES ACROSS SOUTHEAST CALIFORNIA...AROUND
0.75 TO 1 INCHES AROUND THE PHOENIX AREA...AND UPWARDS OF 1.5 EAST
OF PHOENIX. NATURALLY...HIGHER AMOUNTS ARE EXPECTED WITHIN THE
STRONGER SHOWERS/STORMS BUT OVERALL THESE VALUES FIT IN WELL WITH
CIPS ANALOGS. WILL HOLD OFF ISSUING ANY SORT OF FLOOD WATCHES BUT
NUISANCE FLOODING OF LOW LYING AREAS AND/OR NORMALLY DRY WASHES
CANT BE RULED OUT. SNOWFALL POTENTIAL REMAINS LIMITED AS THIS
SYSTEM WILL CONTINUE TO IMPORT WARM SOUTHERLY AIR INTO THE REGION
UNTIL SUNDAY. SNOW LEVELS WILL DROP TO AROUND 6500FT ON SUNDAY AS
PRECIP IS DRAWING TO A CLOSE. ASIDE FROM THE TOPS OF THE VERY
HIGHEST PEAKS EAST OF PHOENIX...SNOWFALL APPEARS HIGHLY UNLIKELY.
THE WEATHER TURNS MUCH MUCH QUIETER FROM MONDAY ONWARD AS WEAK ZONAL
FLOW TRANSITIONS INTO WEAK RIDGING BY MID WEEK. DRY WEATHER IS A
LOCK FROM MONDAY ONWARD ALONG WITH STEADILY INCREASING TEMPS
EVENTUALLY REACHING THE LOWER 80S TOWARD THE END OF THE WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
AN APPROACHING LOW PRESSURE SYSTEM WILL LEAD TO STRENGTHENING
SOUTHWEST FLOW ALOFT TODAY WITH PROLONGED DIRECTIONS OF
SOUTH-SOUTHEAST THROUGH SOUTH-SOUTHWEST THIS AFTERNOON AND TONIGHT.
ANTICIPATE GUSTS OF 20-25 KTS AFTER 22Z AND CONTINUING OVERNIGHT.
SPOTTY SHOWERS WILL DEVELOP AFTER 22Z AND BECOME MUCH MORE NUMEROUS
AFTER 03Z. ACCORDINGLY...CLOUDS WILL THICKEN DURING THE DAY WITH
BASES GETTING NEAR 6 KFT MSL BY 00Z AND QUITE POSSIBLY GETTING BELOW
5 KFT AFTER 03Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
COLD FRONT MOVING INTO SOUTHEAST CALIFORNIA AS OF 12Z AND PRODUCING
AREAS OF LIGHT SHOWERS. EXPECT WIDESPREAD CIGS OF 6-8 KFT MSL
THROUGH 21Z...LOCALLY LOWER...BEFORE STARTING TO IMPROVE FROM WEST
TO EAST. STRONG SOUTH AND SOUTHWEST WINDS ALOFT WILL BEGIN TO
TRANSLATE TO THE SURFACE AFTER 15Z WITH GUSTS OF 25-30 KTS COMMON
AFTER 18Z. ANOTHER ROUND OF SHOWERS IS POSSIBLE AFTER 09Z SATURDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A LOW PRESSURE SYSTEM WILL EXIT THE FORECAST AREA SUNDAY. THERE WILL
BE A LINGERING CHANCE OF SHOWERS SUNDAY...MAINLY OVER THE HIGHER
TERRAIN OF SOUTH-CENTRAL ARIZONA. TEMPERATURES WILL STILL BE BELOW
NORMAL SUNDAY AND HUMIDITIES WILL BE ELEVATED. HIGH PRESSURE BUILDS
BACK INTO THE REGION MONDAY THROUGH THURSDAY FOR A WARMING TREND
ALONG WITH LESS WIND. HUMIDITIES WILL DECREASE THOUGH OVERNIGHT
RECOVERY WILL REMAIN GOOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WIND ADVISORY FROM 10 AM THIS MORNING TO 10 PM PST THIS EVENING
CAZ033.
WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR CAZ030.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...AJ
FIRE WEATHER...AJ
AREA FORECAST DISCUSSION
NWS TOPEKA KS
555 AM CST Fri Feb 28 2014
.SHORT TERM...(Today and Tonight)
Issued at 355 AM CST FRI FEB 28 2014
Latest water vapor satellite loop at 08Z shows a compact
shortwave trough over southeast Colorado into the Texas Panhandle.
Regional radar showing precipitation breaking out from southern
Kansas south into Oklahoma. 00Z TOP and area soundings show quite
a bit of dry air in place. Initial precipitation will go into
moistening the column and forecast soundings from the RUC and NAM
suggest that this should start to occur between 12Z and 15Z when
precipitation should start making it to the ground. Initially
cooling to the wet bulb would give sleet at first then
transitioning over to all rain after 15Z, so not expecting much
ice accumulation this morning. Models are indicating good warm
advection today ahead of the arctic front which was just moving
into western North Dakota and Montana at 09Z. Mixing from 875 mb
today and factoring cloud cover will go lower than MOS temps with
highs in the lower to middle 40s.
Tonight the cold front will move south across the CWA with
temperatures falling back into the teens north to the middle 20s
southeast of Interstate 35. Chances of light rain will continue
early this evening as additional lift is expected as additional
shortwave energy moves through and also some low level frontogenetic
forcing along the cold front. precipitation still looks to be all
rain before ending early this evening, could not rule out a mix
along the Kansas and Nebraska border though.
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CST FRI FEB 28 2014
Rapid pressure rises underway in eastern Montana this morning with
surface temps near -30 F in central Manitoba and Saskatchewan with
water vapor showing northerlies over it. To the west, rather potent
upper low making eastward progress toward California with one
stronger embedded wave nearing the coast at 08Z. Although modifying
with time, these features come together over the Central Plains this
weekend for a potential winter storm.
Overall setup hasn`t changed a lot, but model differences remain
rather large in smaller scale features, leaving confidence much
lower than that in the days preceding the heavy snow event of early
this month. Differences throughout the troposphere in temperature
and moisture profiles as well as upper energy moving through, the
location and duration of frontogenesis, and the sharpness and
intensity of the warm nose lead the list of potential pitfalls to
how this storm plays out. 0Z models range from the slow NAM to the
fast ECMWF with GEM and GFS in between. The NAM and GFS are more
robust with the aforementioned lead wave passing just north Saturday
evening and then slower with the larger scale wave Sunday, with the
GEM and ECMWF opposing these ideas.
Still looking like much of Saturday will be spent moistening the mid
levels, but by late morning low level isentropic lift may be enough
for freezing drizzle and flurries to be generated. Chances for
measurable amounts increase quickly late in the day, though the NAM
and GFS would suggest a break overnight behind the lead wave. In
either event, fast mid level flow will bring the potential for
longer lived frontogenetic bands under CSI or perhaps brief CI in
the snow growth zone. Upper lift then picks up for much of Sunday as
the main wave passes. Didn`t alter precipitation types much given
uncertainty in the details of the warm nose and how saturated it may
be for at least early in the event. This still keeps the heavier
snow in the northern to central portions of the area with moderate
ice accumulations from freezing rain in the south, and periods of
sleet for most locations. Still not looking like a major ice event
in the very cold low levels and 850 mb front staying well south.
Overall trends suggested a bit stronger wind speeds and colder
temps, giving some concern for blowing snow and hazardous wind chills
as well. Actual air temps should fall to around record levels for both
highs and lows into Monday.
Zonal flow takes hold for the remainder of the forecast resulting in
moderating temps. Some decent agreement with a longer wavelength
trough passing around Wednesday though moisture values likely quite
limited for only light precip opportunities.
&&
.AVIATION...(For the 12Z TAFs through 12Z Saturday Morning)
Issued at 527 AM CST FRI FEB 28 2014
VFR conditions at the start of the period are expected to continue
through 22Z then cigs becoming MVFR. Some light precipitation in
the form of rain perhaps a brief period of sleet is possible prior
to 15Z but most likely will remain south of the terminals. However
by 18Z I did include a VCSH to the terminals. A cold front moves
south across the terminals in the 22Z to 00Z time period shifting
winds to the north and increasing to near 14 kts. MVFR cigs are
expected after 00Z.
&&
.CLIMATE...
Issued at 555 AM CST FRI FEB 28 2014
Record lowest minimum and lowest maximum temperatures...
March 1 March 2 March 3 Any Day in March
Topeka -1/18 -3/14 -1/16 -7/9
Concordia -2/15 -4/15 -6/12 -11/8
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Saturday evening through late Sunday
night FOR KSZ008>012-020>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...53
LONG TERM...65
AVIATION...53
CLIMATE...65
AREA FORECAST DISCUSSION
NWS TOPEKA KS
527 AM CST Fri Feb 28 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 355 AM CST FRI FEB 28 2014
Latest water vapor satellite loop at 08Z shows a compact
shortwave trough over southeast Colorado into the Texas Panhandle.
Regional radar showing precipitation breaking out from southern
Kansas south into Oklahoma. 00Z TOP and area soundings show quite
a bit of dry air in place. Initial precipitation will go into
moistening the column and forecast soundings from the RUC and NAM
suggest that this should start to occur between 12Z and 15Z when
precipitation should start making it to the ground. Initially
cooling to the wet bulb would give sleet at first then
transitioning over to all rain after 15Z, so not expecting much
ice accumulation this morning. Models are indicating good warm
advection today ahead of the arctic front which was just moving
into western North Dakota and Montana at 09Z. Mixing from 875 mb
today and factoring cloud cover will go lower than MOS temps with
highs in the lower to middle 40s.
Tonight the cold front will move south across the CWA with
temperatures falling back into the teens north to the middle 20s
southeast of Interstate 35. Chances of light rain will continue
early this evening as additional lift is expected as additional
shortwave energy moves through and also some low level frontogenetic
forcing along the cold front. precipitation still looks to be all
rain before ending early this evening, could not rule out a mix
along the Kansas and Nebraska border though.
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CST FRI FEB 28 2014
Rapid pressure rises underway in eastern Montana this morning with
surface temps near -30 F in central Manitoba and Saskatchewan with
water vapor showing northerlies over it. To the west, rather potent
upper low making eastward progress toward California with one
stronger embedded wave nearing the coast at 08Z. Although modifying
with time, these features come together over the Central Plains this
weekend for a potential winter storm.
Overall setup hasn`t changed a lot, but model differences remain
rather large in smaller scale features, leaving confidence much
lower than that in the days preceding the heavy snow event of early
this month. Differences throughout the troposphere in temperature
and moisture profiles as well as upper energy moving through, the
location and duration of frontogenesis, and the sharpness and
intensity of the warm nose lead the list of potential pitfalls to
how this storm plays out. 0Z models range from the slow NAM to the
fast ECMWF with GEM and GFS in between. The NAM and GFS are more
robust with the aforementioned lead wave passing just north Saturday
evening and then slower with the larger scale wave Sunday, with the
GEM and ECMWF opposing these ideas.
Still looking like much of Saturday will be spent moistening the mid
levels, but by late morning low level isentropic lift may be enough
for freezing drizzle and flurries to be generated. Chances for
measurable amounts increase quickly late in the day, though the NAM
and GFS would suggest a break overnight behind the lead wave. In
either event, fast mid level flow will bring the potential for
longer lived frontogenetic bands under CSI or perhaps brief CI in
the snow growth zone. Upper lift then picks up for much of Sunday as
the main wave passes. Didn`t alter precipitation types much given
uncertainty in the details of the warm nose and how saturated it may
be for at least early in the event. This still keeps the heavier
snow in the northern to central portions of the area with moderate
ice accumulations from freezing rain in the south, and periods of
sleet for most locations. Still not looking like a major ice event
in the very cold low levels and 850 mb front staying well south.
Overall trends suggested a bit stronger wind speeds and colder
temps, giving some concern for blowing snow and hazardous wind chills
as well. Actual air temps should fall to around record levels for both
highs and lows into Monday.
Zonal flow takes hold for the remainder of the forecast resulting in
moderating temps. Some decent agreement with a longer wavelength
trough passing around Wednesday though moisture values likely quite
limited for only light precip opportunities.
&&
.AVIATION...(For the 12Z TAFs through 12Z Saturday Morning)
Issued at 527 AM CST FRI FEB 28 2014
VFR conditions at the start of the period are expected to continue
through 22Z then cigs becoming MVFR. Some light precipitation in
the form of rain perhaps a brief period of sleet is possible prior
to 15Z but most likely will remain south of the terminals. However
by 18Z I did include a VCSH to the terminals. A cold front moves
south across the terminals in the 22Z to 00Z time period shifting
winds to the north and increasing to near 14 kts. MVFR cigs are
expected after 00Z.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Saturday evening through late Sunday
night FOR KSZ008>012-020>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...53
LONG TERM...65
AVIATION...53
AREA FORECAST DISCUSSION
NWS HASTINGS NE
945 AM CST FRI FEB 28 2014
.UPDATE...
ISSUED AT 944 AM CST FRI FEB 28 2014
HAD TO BACKTRACK ON THE CLOUD COVER CHANGES NOW THAT THE FIRST
VISIBLE SAT IMAGES ARE AVAILABLE. A SHIELD OF 1200-2800 FT
OVERCAST IS ADVANCING SE THRU THE SANDHILLS BEHIND THE COLD FRONT.
SO ANY LITTLE SUN THIS MORNING OVER S-CNTRL NEB WILL SOON END.
S OF THE SNOWPACK OVER N-CNTRL KS...IT`S SHAPING UP TO BE A VERY
NICE DAY AND WE COULD BE A LITTLE LOW ON HIGH TEMPS BASED ON
MORNING SOUNDINGS. HOWEVER...THE FRONTAL PASSAGE RESTRAINS
CONFIDENCE IN INCREASING TEMPS JUST YET.
HAVE ALSO MADE SOME MAJOR ADJUSTMENTS TO DEWPOINTS THRU SUNSET. WE
WERE NOT LOW ENOUGH NE OF THE TRI-CITIES. HAVE ADJUSTED THE FCST
USING THE CONSENSUS OF SHORT-TERM GUIDANCE.
UPDATE ISSUED AT 845 AM CST FRI FEB 28 2014
NO SUBSTANTIVE CHANGES NEEDED FOR THIS ESTF UPDATE. BASED ON
SATELLITE...CLOUDS WERE BACKED DOWN THIS AFTERNOON AND POSSIBLY
NOT AS MUCH AS NECESSARY. BUT BELIEVE WE HAVE TRENDED THE FCST IN
THE RIGHT DIRECTION.
THE FRONT IS PROGRESSING THRU THE SANDHILLS AND PANHANDLE. I LIKE
THE WINDS WE HAVE IN THE FCST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 503 AM CST FRI FEB 28 2014
THE FIRST PART OF THE DAY WILL SEE VFR CONDITIONS AHEAD OF AN
APPROACHING COLD FRONTAL BOUNDARY. THE FRONT WILL REACH THE
TERMINAL EARLY THIS AFTERNOON WITH WINDS TRANSITIONING NORTH
AND INCREASING BEHIND THE FRONT. WIND SPEEDS WILL INCREASE TO NEAR
20KTS AND GUSTS OF 25 TO 30KTS ARE POSSIBLE. LIGHT PRECIPITATION
MAY ACCOMPANY THE COLD FRONTAL PASSAGE AND INCLUDED A BRIEF PERIOD
OF LIGHT SNOW. OTHERWISE LOOK FOR WINDS TO REMAIN STEADY INTO THE
OVERNIGHT HOURS FROM THE NORTH AND CIGS SHOULD AVERAGE IN THE MVFR
CATEGORY.
&&
.CLIMATE...
ISSUED AT 726 AM CST FRI FEB 28 2014
AVERAGE FEB TEMP AT GRAND ISLAND: AS OF MIDNIGHT IT SITS AT 23.4F
AND GIVEN THE LOW OF 15F THIS MORNING...AND THE PROJECTED HIGH
TODAY...IT LOOKS LIKE GRI WILL FINISH THE MONTH WITH AN AVG TEMP
OF 23.5F /5.5 COLDER THAN NORMAL/. THAT WILL MAKE THIS THE
COLDEST FEB SINCE 2001 WHEN THE AVG TEMP WAS 20.6F.
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY RECORDS...ITS
NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY COULD COME VERY
CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON RECORD FOR ANY
DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...FAY
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
846 AM CST FRI FEB 28 2014
.UPDATE...
ISSUED AT 845 AM CST FRI FEB 28 2014
NO SUBSTATIVE CHANGES NEEDED FOR THIS ESTF UPDATE. BASED ON
SATELLITE...CLOUDS WERE BACKED DOWN THIS AFTERNOON AND POSSIBLY
NOT AS MUCH AS NECESSARY. BUT BELIEVE WE HAVE TRENDED THE FCST IN
THE RIGHT DIRECTION.
THE FRONT IS PROGRESSING THRU THE SANDHILLS AND PANHANDLE. I LIKE
THE WINDS WE HAVE IN THE FCST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 503 AM CST FRI FEB 28 2014
THE FIRST PART OF THE DAY WILL SEE VFR CONDITIONS AHEAD OF AN
APPROACHING COLD FRONTAL BOUNDARY. THE FRONT WILL REACH THE
TERMINAL EARLY THIS AFTERNOON WITH WINDS TRANSITIONING NORTH
AND INCREASING BEHIND THE FRONT. WIND SPEEDS WILL INCREASE TO NEAR
20KTS AND GUSTS OF 25 TO 30KTS ARE POSSIBLE. LIGHT PRECIPITATION
MAY ACCOMPANY THE COLD FRONTAL PASSAGE AND INCLUDED A BRIEF PERIOD
OF LIGHT SNOW. OTHERWISE LOOK FOR WINDS TO REMAIN STEADY INTO THE
OVERNIGHT HOURS FROM THE NORTH AND CIGS SHOULD AVERAGE IN THE MVFR
CATEGORY.
&&
.CLIMATE...
ISSUED AT 726 AM CST FRI FEB 28 2014
AVERAGE FEB TEMP AT GRAND ISLAND: AS OF MIDNIGHT IT SITS AT 23.4F
AND GIVEN THE LOW OF 15F THIS MORNING...AND THE PROJECTED HIGH
TODAY...IT LOOKS LIKE GRI WILL FINISH THE MONTH WITH AN AVG TEMP
OF 23.5F /5.5 COLDER THAN NORMAL/. THAT WILL MAKE THIS THE
COLDEST FEB SINCE 2001 WHEN THE AVG TEMP WAS 20.6F.
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY RECORDS...ITS
NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY COULD COME VERY
CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON RECORD FOR ANY
DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...FAY
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
726 AM CST FRI FEB 28 2014
PLEASE SEE UPDATED CLIMATE SECTION FOR INFO ON WHERE THE MONTHLY
AVERAGE TEMP WILL SETTLE AT GRAND ISLAND. JH
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 503 AM CST FRI FEB 28 2014
THE FIRST PART OF THE DAY WILL SEE VFR CONDITIONS AHEAD OF AN
APPROACHING COLD FRONTAL BOUNDARY. THE FRONT WILL REACH THE
TERMINAL EARLY THIS AFTERNOON WITH WINDS TRANSITIONING NORTH
AND INCREASING BEHIND THE FRONT. WIND SPEEDS WILL INCREASE TO NEAR
20KTS AND GUSTS OF 25 TO 30KTS ARE POSSIBLE. LIGHT PRECIPITATION
MAY ACCOMPANY THE COLD FRONTAL PASSAGE AND INCLUDED A BRIEF PERIOD
OF LIGHT SNOW. OTHERWISE LOOK FOR WINDS TO REMAIN STEADY INTO THE
OVERNIGHT HOURS FROM THE NORTH AND CIGS SHOULD AVERAGE IN THE MVFR
CATEGORY.
&&
.CLIMATE...
ISSUED AT 726 AM CST FRI FEB 28 2014
AVERAGE FEB TEMP AT GRAND ISLAND: AS OF MIDNIGHT IT SITS AT 23.4F
AND GIVEN THE LOW OF 15F THIS MORNING...AND THE PROJECTED HIGH
TODAY...IT LOOKS LIKE GRI WILL FINISH THE MONTH WITH AN AVG TEMP
OF 23.5F /5.5 COLDER THAN NORMAL/. THAT WILL MAKE THIS THE
COLDEST FEB SINCE 2001 WHEN THE AVG TEMP WAS 20.6F.
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY RECORDS...ITS
NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY COULD COME VERY
CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON RECORD FOR ANY
DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...FAY
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
510 AM CST FRI FEB 28 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 503 AM CST FRI FEB 28 2014
THE FIRST PART OF THE DAY WILL SEE VFR CONDITIONS AHEAD OF AN
APPROACHING COLD FRONTAL BOUNDARY. THE FRONT WILL REACH THE
TERMINAL EARLY THIS AFTERNOON WITH WINDS TRANSITIONING NORTH
AND INCREASING BEHIND THE FRONT. WIND SPEEDS WILL INCREASE TO NEAR
20KTS AND GUSTS OF 25 TO 30KTS ARE POSSIBLE. LIGHT PRECIPITATION
MAY ACCOMPANY THE COLD FRONTAL PASSAGE AND INCLUDED A BRIEF PERIOD
OF LIGHT SNOW. OTHERWISE LOOK FOR WINDS TO REMAIN STEADY INTO THE
OVERNIGHT HOURS FROM THE NORTH AND CIGS SHOULD AVERAGE IN THE MVFR
CATEGORY.
&&
.CLIMATE...
ISSUED AT 430 PM CST THU FEB 27 2014
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY
RECORDS...ITS NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY
COULD COME VERY CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON
RECORD FOR ANY DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...FAY
CLIMATE...PFANNKUCH
AREA FORECAST DISCUSSION
NWS TULSA OK
549 AM CST FRI FEB 28 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
LIGHT RAIN OR SPRINKLES WILL LIKELY AFFECT BVO/FYV/XNA AND PERHAPS
TUL/XNA THIS MORNING...WITH LITTLE IMPACT TO AVIATION EXPECTED. A
PERIOD OF GUSTY SOUTHEASTERLY WINDS WILL ALSO OCCUR AT THE
TERMINALS THIS MORNING AND INTO THE EARLY AFTERNOON. INCREASING
MOISTURE TONIGHT AND AN APPROACHING BOUNDARY WILL LEAD TO MVFR
CIGS AT ALL TERMINALS AFTER MIDNIGHT.
&&
.PREV DISCUSSION... /ISSUED 436 AM CST FRI FEB 28 2014/
DISCUSSION...
THE MAIN FORECAST CHALLENGE WILL BE WINTRY PRECIP POTENTIAL
SATURDAY NIGHT THROUGH SUNDAY NIGHT.
THE FIRST IN A SERIES OF UPPER WAVES TO SWEEP ACROSS THE CENTRAL
PART OF THE COUNTRY WILL MOVE ACROSS TODAY. THE SYSTEM WILL BRING
SHOWERS MAINLY THIS MORNING INTO THE EARLY AFTERNOON...WITH THE
BEST CHANCES NORTH OF I-40. TEMPERATURES WILL BE NEAR FREEZING
OVER IN NORTHWEST ARKANSAS AT ONSET...THOUGH THE LATEST DATA FROM
THE HRRR SUGGESTS TEMPS WILL WARM UP QUICKLY THIS MORNING AS MORE
PRECIP MOVES IN AND SOUTH WINDS INCREASE. IN FACT...MOST AREAS
WILL SEE WARMER TEMPS BY AFTERNOON...ESPECIALLY DOWN SOUTH WHERE
SKIES ARE EXPECTED TO CLEAR.
THE BIG STORM TO HIT SOCAL TODAY WILL SWING INTO THE SOUTHERN
PLAINS SUNDAY. MEANWHILE...SIGNIFICANT AMPLIFICATION OF THE HIGHER
LATITUDE FLOW WILL SEND ANOTHER ARCTIC SURGE OUR WAY THIS WEEKEND.
THE SOURCE REGION FOR THIS AIRMASS IS NEAR THE POLE. IT WILL FEEL
MORE LIKE DECEMBER OR JANUARY BEHIND THIS FRONT...INSTEAD OF EARLY
MARCH. INCREASING LOW LVL FRONTOGENESIS WILL GET PRECIP GOING
SATURDAY NIGHT UP NORTH...SPREADING SOUTH AND EAST SUNDAY. A
SECONDARY ROUND OF PRECIP WITH THE MAIN UPPER SYSTEM IS POSSIBLE
ACROSS NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS SUNDAY NIGHT.
MODEL SOUNDINGS ARE QUITE IMPRESSIVE...SHOWING BASICALLY TWO
EXTREMES IN THE WARM LAYER AND THE COLD LAYER CLOSER TO THE
GROUND. FOR MUCH OF EASTERN OKLAHOMA THIS LOOKS LIKE PRIMARILY A
SLEET STORM...AFTER A BRIEF PERIOD OF FREEZING RAIN NEAR ONSET.
THE COLD AIR NEAR THE GROUND WILL BE DEEP ENOUGH AND COLD ENOUGH
TO REFREEZE HYDROMETEORS BEFORE THEY REACH THE GROUND. FARTHER TO
THE EAST OVER NW AR AND NEIGHBORING E CNTRL OK...THE DEPTH OF THE
COLD AIR WILL NOT BE AS DEEP...WHICH HAS SOMETHING TO DO WITH THE
TERRAIN OF WESTERN AR. AS A RESULT...MORE ICING IS EXPECTED THERE
THAN POINTS WEST. ELEVATED INSTABILITY IN THE JUICY GULF AIRMASS
RIDING UP AND OVER THE FRONT WILL SUPPORT ISOLATED TO SCATTERED
STORMS. BY SUNDAY NIGHT...MUCH OF THE PRECIP WILL BE ENDING EXPECT
POSSIBLY ACROSS NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS AS
AFOREMENTIONED. THE WARM LAYER WILL HAVE ERODED ENOUGH BY THIS
TIME TO FAVOR SNOW AND SOME SLEET. BASED ON THE AMOUNT OF
ACCUMULATING ICE AND SLEET FORECAST...A WINTER STORM WATCH HAS
BEEN HOISTED FOR MUCH OF THE FORECAST AREA SATURDAY EVENING THRU
SUNDAY EVENING. VERY COLD TEMPERATURES WILL CONTINUE INTO
MONDAY...DESPITE THE SUN RETURNING. MODIFICATION IS EXPECTED FOR
THE REMAINDER OF THE WEEK IN A MUCH MORE ZONAL PATTERN OVER NOAM
BY THIS TIME.
ANOTHER SYSTEM MAY AFFECT THE REGION TOWARD MIDWEEK...BRINGING A
CHANCE FOR RAIN. WINTRY PRECIP IS NOT EXPECTED WITH THIS SYSTEM AS THE
AIRMASS WILL HAVE MODIFIED BY THIS TIME.
LACY
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ049-OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-
OKZ061-OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-
OKZ069-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
ARZ001-ARZ002-ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...22
LONG TERM....30
AVIATION...22
AREA FORECAST DISCUSSION
NWS TULSA OK
436 AM CST FRI FEB 28 2014
.DISCUSSION...
THE MAIN FORECAST CHALLENGE WILL BE WINTRY PRECIP POTENTIAL
SATURDAY NIGHT THROUGH SUNDAY NIGHT.
THE FIRST IN A SERIES OF UPPER WAVES TO SWEEP ACROSS THE CENTRAL
PART OF THE COUNTRY WILL MOVE ACROSS TODAY. THE SYSTEM WILL BRING
SHOWERS MAINLY THIS MORNING INTO THE EARLY AFTERNOON...WITH THE
BEST CHANCES NORTH OF I-40. TEMPERATURES WILL BE NEAR FREEZING
OVER IN NORTHWEST ARKANSAS AT ONSET...THOUGH THE LATEST DATA FROM
THE HRRR SUGGESTS TEMPS WILL WARM UP QUICKLY THIS MORNING AS MORE
PRECIP MOVES IN AND SOUTH WINDS INCREASE. IN FACT...MOST AREAS
WILL SEE WARMER TEMPS BY AFTERNOON...ESPECIALLY DOWN SOUTH WHERE
SKIES ARE EXPECTED TO CLEAR.
THE BIG STORM TO HIT SOCAL TODAY WILL SWING INTO THE SOUTHERN
PLAINS SUNDAY. MEANWHILE...SIGNIFICANT AMPLIFICATION OF THE HIGHER
LATITUDE FLOW WILL SEND ANOTHER ARCTIC SURGE OUR WAY THIS WEEKEND.
THE SOURCE REGION FOR THIS AIRMASS IS NEAR THE POLE. IT WILL FEEL
MORE LIKE DECEMBER OR JANUARY BEHIND THIS FRONT...INSTEAD OF EARLY
MARCH. INCREASING LOW LVL FRONTOGENESIS WILL GET PRECIP GOING
SATURDAY NIGHT UP NORTH...SPREADING SOUTH AND EAST SUNDAY. A
SECONDARY ROUND OF PRECIP WITH THE MAIN UPPER SYSTEM IS POSSIBLE
ACROSS NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS SUNDAY NIGHT.
MODEL SOUNDINGS ARE QUITE IMPRESSIVE...SHOWING BASICALLY TWO
EXTREMES IN THE WARM LAYER AND THE COLD LAYER CLOSER TO THE
GROUND. FOR MUCH OF EASTERN OKLAHOMA THIS LOOKS LIKE PRIMARILY A
SLEET STORM...AFTER A BRIEF PERIOD OF FREEZING RAIN NEAR ONSET.
THE COLD AIR NEAR THE GROUND WILL BE DEEP ENOUGH AND COLD ENOUGH
TO REFREEZE HYDROMETEORS BEFORE THEY REACH THE GROUND. FARTHER TO
THE EAST OVER NW AR AND NEIGHBORING E CNTRL OK...THE DEPTH OF THE
COLD AIR WILL NOT BE AS DEEP...WHICH HAS SOMETHING TO DO WITH THE
TERRAIN OF WESTERN AR. AS A RESULT...MORE ICING IS EXPECTED THERE
THAN POINTS WEST. ELEVATED INSTABILITY IN THE JUICY GULF AIRMASS
RIDING UP AND OVER THE FRONT WILL SUPPORT ISOLATED TO SCATTERED
STORMS. BY SUNDAY NIGHT...MUCH OF THE PRECIP WILL BE ENDING EXPECT
POSSIBLY ACROSS NORTHEAST OKLAHOMA AND FAR NORTHWEST ARKANSAS AS
AFOREMENTIONED. THE WARM LAYER WILL HAVE ERODED ENOUGH BY THIS
TIME TO FAVOR SNOW AND SOME SLEET. BASED ON THE AMOUNT OF
ACCUMULATING ICE AND SLEET FORECAST...A WINTER STORM WATCH HAS
BEEN HOISTED FOR MUCH OF THE FORECAST AREA SATURDAY EVENING THRU
SUNDAY EVENING. VERY COLD TEMPERATURES WILL CONTINUE INTO
MONDAY...DESPITE THE SUN RETURNING. MODIFICATION IS EXPECTED FOR
THE REMAINDER OF THE WEEK IN A MUCH MORE ZONAL PATTERN OVER NOAM
BY THIS TIME.
ANOTHER SYSTEM MAY AFFECT THE REGION TOWARD MIDWEEK...BRINGING A
CHANCE FOR RAIN. WINTRY PRECIP IS NOT EXPECTED WITH THIS SYSTEM AS THE
AIRMASS WILL HAVE MODIFIED BY THIS TIME.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 60 36 54 22 / 50 0 10 70
FSM 55 40 65 40 / 30 0 10 60
MLC 64 40 67 31 / 20 0 10 60
BVO 55 29 46 17 / 60 0 10 70
FYV 50 33 61 30 / 50 0 10 60
BYV 47 33 60 27 / 60 0 10 60
MKO 59 38 63 27 / 30 0 10 60
MIO 49 29 52 19 / 60 10 10 70
F10 62 39 62 26 / 20 0 10 70
HHW 66 44 72 46 / 20 0 10 50
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
OKZ049-OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-
OKZ061-OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-
OKZ069-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER STORM WATCH FROM 6 PM SATURDAY TO MIDNIGHT MONDAY FOR
ARZ001-ARZ002-ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
235 PM EST FRI FEB 28 2014
...CHAMBER OF COMMERCE TYPE WEEKEND ON THE WAY...
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING A NOW RATHER UNAMPLIFIED
UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. MOST IMPRESSIVE
WEATHER SYSTEM IS A STRONG UPPER LOW AND ASSOCIATED MOISTURE PLUME
SPREADING INLAND OVER CALIFORNIA/OREGON. THE OVERALL NORTHERN STREAM
FLOW AS BECOME MUCH MORE ZONAL IN NATURE ALONG THE US/CANADIAN
BORDER HELPING TO LOCK THE COLDEST AIR FURTHER NORTH THAN IN
PREVIOUS DAYS. FURTHER SOUTH...VERY BROAD SOUTHERN STREAM TROUGHING
IN WORKING ITS WAY ALONG THE NORTHERN GULF COAST. ONE PIECE OF
SHORTWAVE ENERGY EMBEDDED WITHIN THIS FLOW IS NOW PASSING EAST OF
THE ARKLATEX REGION. HAVE EVEN SEE A FEW LIGHTNING STRIKES
ASSOCIATED WITH THIS ENERGY. HOWEVER...THE MAIN ENERGY WITH THIS
IMPULSE WILL BE PASSING MAINLY TO OUR NORTH TONIGHT...AND WITH
LITTLE IN THE WAY OF COLUMN MOISTURE LEFT OVER OUR HEADS...ITS
PASSAGE SHOULD BE HARMLESS IN TERMS OF SENSIBLE WEATHER. SPEAKING
OF COLUMN MOISTURE...A NEW AIRMASS THROUGH THE TROP COLUMN HAS
ARRIVED IN THE PAST 24 HOURS. THURSDAY MORNING...KTBW SOUNDING
PROFILE WAS QUITE SATURATED WITH A PW OF 1.36". THIS MORNING WE SEE
MUCH LARGER DEWPOINT DEPRESSIONS AND PW DOWN TO AROUND 0.55". THE
DRY COLUMN AND OVERALL LACK OF SYNOPTIC FORCING FOR LIFT IS
RESULTING IN OUR MOSTLY SUNNY SKIES THIS AFTERNOON.
AT THE SURFACE...1030MB HIGH PRESSURE CENTERED OVER THE MID-ATLANTIC
STATES RIDGES ALL THE WAY SOUTH TO THE EASTERN GULF OF MEXICO AND FL
PENINSULA. THIS RIDGE WILL SETTLE SOUTHWARD SLOWLY WITH TIME AND
HELP PROVIDE FAIR AND DRY WEATHER TO THE FORECAST AREA THROUGH THE
UPCOMING WEEKEND. IT WAS A COOL START THIS MORNING WITH EVEN SOME
TEMPERATURES FLIRTING WITH FREEZING UP TOWARD LEVY COUNTY...HOWEVER
THE ABUNDANT SUNSHINE AND LACK OF CAA HAVE ALLOWED A DECENT DIURNAL
REBOUND. CONDITIONS ARE ALSO QUITE DRY OUT THERE THIS AFTERNOON WITH
LOW RELATIVE HUMIDITY ACROSS MUCH OF THE AREA. TAKE CAUTION WITH ANY
TYPE OF BURNING THROUGH THE AFTERNOON AND EARLY EVENING.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
A QUIET PATTERN WITH MODERATING TEMPERATURES IN TERMS OF SENSIBLE
WEATHER THROUGH THE UPCOMING WEEKEND.
TONIGHT...
MID/UPPER LEVEL SHORTWAVE ENERGY APPROACHES AND PASSES OVER THE
REGION. HOWEVER...WITH LITTLE IN THE WAY OF COLUMN MOISTURE...THE
ONLY INFLUENCE EXPECTED IS PERHAPS A BAND OF HIGHER AND LIKELY
MOSTLY TRANSPARENT CIRRUS PASSING OVER THE NORTHERN ZONES. THE
SURFACE RIDGE IN PLACE ALONG WITH THE DRY COLUMN WILL ALLOW FOR
DECENT RADIATIONAL COOLING CONDITIONS ACROSS THE AREA...AND DO
EXPECT ANOTHER COOL MORNING...ALTHOUGH NOT AS COOL UP OVER THE
NORTHERN NATURE COAST ZONES AS THIS PAST MORNING. CURRENT FORECAST
DOES NOT SUPPORT ANY SUB-FREEZING TEMPERATURES. CAN NOT RULE OUT A
FEW PATCHES OF FROST IN THE NORMALLY COLDER SPOTS ACROSS LEVY
COUNTY...BUT DO NOT EXPECT ENOUGH COVERAGE TO WARRANT ANY KIND OF
ADVISORY AS IT STANDS NOW. ELSEWHERE MID/UPPER 40S FOR LOW TEMPS
AROUND SUNRISE WILL EXTEND SOUTHWARD INTO THE CENTRAL PENINSULA WITH
LOW/MID 50S ALONG THE IMMEDIATE COAST AND DOWN TOWARD FT MYERS.
SATURDAY/SUNDAY...
NOT A WHOLE LOT TO SPEAK OF FROM A SYNOPTIC STANDPOINT. SHORTWAVE
ENERGY WILL EXIT QUICKLY EARLY SATURDAY MORNING ALLOWING HEIGHTS TO
RISE THROUGH THE DAY. IN RESPONSE TO THE NEXT SHORTWAVE SPREADING
ACROSS THE SOUTHERN PLAINS THIS WEEKEND...THESE HEIGHTS WILL
ACTUALLY RIDGE UP DOWNSTREAM OVER THE EASTERN GULF AND FLORIDA
PENINSULA BY SATURDAY NIGHT/SUNDAY. THE STACKED RIDGING PROVIDES A
PLEASANT AND CONTINUED WARMING PATTERN OVER OUR HEADS.
TEMPERATURES WILL REBOUND NICELY DURING THE DAY ON SATURDAY WITH
WIDESPREAD LOWER/MID 70S NORTH OF THE I-4 CORRIDOR AND MID/UPPER 70S
FURTHER SOUTH. TEMPERATURES WILL BE FLIRTING WITH 80 IN FT. MYERS.
THE LIGHT GRADIENT AND STRONG TERRESTRIAL HEATING WILL FORCE
AFTERNOON SEA-BREEZES TO TURN THE FLOW ONSHORE AT THE BEACHES IN THE
AFTERNOON. THIS ONSHORE FLOW WILL LIKELY DROP TEMPS A FEW
DEGREES...ESPECIALLY FROM MANATEE COUNTY NORTHWARD. SATURDAY NIGHT
SEES NO FROST CONCERNS...WITH MOST LOCATIONS A GOOD 5-8 DEGREES
WARMER THAN FRIDAY NIGHT. COOLEST TEMPS IN THE MID 40S WILL BE OVER
LEVY COUNTY RANGING UP TO THE 50S TOWARD THE I-4 CORRIDOR AND
SOUTHWARD. BY SUNDAY...HIGH TEMPS OVER THE INTERIOR WILL LIKELY
APPROACH OR SURPASS 80 DEGREES UNDER ABUNDANT SUNSHINE. AFTERNOON
SEA-BREEZES WILL KEEP IT A BIT COOLER ALONG AREA BEACHES...BUT STILL
A VERY PLEASANT DAY. ENJOY AND HAVE A GREAT WEEKEND!
&&
.LONG TERM (MONDAY THROUGH FRIDAY)...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT THROUGH TUESDAY...WITH
SOLUTIONS THEN DIVERGING FOR THE MIDDLE AND LATTER PART OF NEXT
WEEK. THE MAIN CHALLENGES REVOLVE AROUND THE PROGRESSIVENESS OF A
COLD FRONT THROUGH THE REGION ON TUESDAY...THEN AROUND THE STRENGTH
OF A STORM SYSTEM TRACKING OUT OF THE GULF OF MEXICO AND ACROSS THE
NORTHERN PENINSULA LATE NEXT WEEK. THE EVOLUTION AND MODEL TRENDS
WILL NEED TO BE MONITORED CLOSELY WITH THIS STORM SYSTEM AS IT IS A
CLIMATOLOGICALLY FAVORABLE TRACK FOR SEVERE WEATHER AND EARLY MARCH
IS TYPICALLY THE START OF THE FLORIDA SEVERE WEATHER SEASON. GIVEN
THE LACK OF GOOD CONTINUITY AMONGST THE MODELS FOR THE MID TO LATE
WEEK TIME FRAME WILL FOLLOW A BLENDED FORECAST APPROACH.
HIGH PRESSURE IS EXPECTED TO LOSE IT/S INFLUENCE OVER THE AREA ON
MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. THE COLD FRONT WILL
THEN SHIFT SOUTHWARD THROUGH THE FORECAST AREA MONDAY NIGHT AND
TUESDAY BEFORE STALLING OUT SOMEWHERE ACROSS SOUTH FLORIDA OR THE
FLORIDA STRAIGHTS TUESDAY NIGHT AND WEDNESDAY. A SHARP UPPER LEVEL
TROUGH IS THEN FORECAST TO DIG ACROSS THE WESTERN GULF ON WEDNESDAY
AND WEDNESDAY NIGHT...AND THIS SHOULD ALLOW THE STALLED FRONT TO
LIFT BACK NORTHWARD INTO THE AREA AS A WARM FRONT. MODEL SOLUTIONS
THEN SHOW A STRENGTHENING AREA OF LOW PRESSURE TRACKING ACROSS THE
NORTHERN GULF COASTAL REGION THURSDAY OR THURSDAY NIGHT AND ACROSS
NORTH FLORIDA THURSDAY NIGHT OR FRIDAY. THE GFS IS THE WEAKER AND
FASTER OF THE TWO SOLUTIONS BUT STILL SHOWS IMPRESSIVE DYNAMIC
FORCING AND STRONG UPPER LEVEL WIND FIELDS PUSHING ACROSS THE
FORECAST AREA. THE ECMWF ON THE OTHER HAND SUGGESTS THAT A
SIGNIFICANT SEVERE WEATHER EVENT COULD BE POSSIBLE ACROSS THE
REGION. WILL HOLD OFF ON MENTIONING ANY SEVERE WEATHER POTENTIAL IN
THE HAZARDOUS WEATHER OUTLOOK FOR NOW AS THERE IS STILL QUITE A BIT
OF TIME BETWEEN NOW AND LATE NEXT WEEK...BUT IT MAY NEED TO BE
MENTIONED AT SOME POINT IN THE NEXT COUPLE OF DAYS IF MODEL
SOLUTIONS COME INTO BETTER AGREEMENT AND GOOD RUN TO RUN CONTINUITY
DEVELOPS. THE STORM SYSTEM WILL THEN EXIT OFF TO THE NORTHEAST NEXT
FRIDAY OR FRIDAY NIGHT...WITH HIGH PRESSURE BUILDING BACK INTO THE
AREA FROM THE WEST.
&&
.AVIATION...
28/18-01/18Z: HIGH PRESSURE RIDGES ACROSS THE AREA WITH SOME CIRRUS
GIVING WAY TO SKC. POSSIBLE PATCHY GROUND FOG VCNTY LAL AND PGD
TOWARD MORNING BUT TOO LIMITED TO INCLUDE IN TAFS. NW WINDS FOR MUCH
OF THE AFTERNOON WILL SHIFT TO NE TONIGHT AND CONTINUE...GOING BACK
TO NW JUST BEYOND 01/18Z.
&&
.MARINE...
HIGH PRESSURE REMAINS IN CONTROL OF THE EASTERN GULF OF MEXICO
THROUGH THE UPCOMING WEEKEND KEEPING WINDS AND WAVES BELOW HEADLINE
CRITERIA. EXPECT WARMING TEMPERATURES OVER LAND TO FORCE AFTERNOON
SEA-BREEZES WITH WINDS TURNING ONSHORE NEAR THE COAST EACH OF THE
NEXT SEVERAL DAYS. WINDS WILL AGAIN SHIFT TO AN OFFSHORE DIRECTION
EACH NIGHT. THE NEXT FRONT LOOKS TO APPROACH THE FORECAST WATERS
MONDAY NIGHT INTO TUESDAY.
&&
.FIRE WEATHER...
DRIER AIR HAS ARRIVED ACROSS THE AREA AND WILL LINGER THROUGH THE
UPCOMING WEEKEND. MANY INLAND AREAS WILL APPROACH OR DROP JUST BELOW
CRITICAL LEVELS OF RELATIVE HUMIDITY ON SATURDAY...HOWEVER WINDS
WILL BE QUITE LIGHT AND NO RED FLAG CONDITIONS ARE EXPECTED TO BE
MET. A SLOW RETURN OF MOISTURE WILL BEGIN SUNDAY NIGHT INTO MONDAY
AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 51 73 58 79 / 0 0 0 0
FMY 51 79 59 84 / 0 0 0 0
GIF 51 77 57 81 / 0 0 0 0
SRQ 49 73 56 78 / 0 0 0 0
BKV 40 75 48 80 / 0 0 0 0
SPG 56 72 61 78 / 0 0 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM...JELSEMA
AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
313 PM EST FRI FEB 28 2014
.SYNOPSIS...
A COASTAL TROUGH WILL DEVELOP JUST OFFSHORE TONIGHT AS A WEDGE OF
HIGH PRESSURE PUSHES SOUTHWARD INTO THE AREA...AND PERSISTS
THROUGH LATE SATURDAY. ATLANTIC HIGH PRESSURE WILL BECOME
ESTABLISHED LATER THIS WEEKEND AHEAD OF A COLD FRONT MOVING
THROUGH BY MONDAY NIGHT. HIGH PRESSURE WILL BUILD AGAIN NORTH OF
THE REGION INTO THE MIDDLE OF NEXT WEEK. A DEVELOPING STORM SYSTEM
COULD AFFECT THE AREA WITH WIDESPREAD RAINFALL BY LATE IN THE WORK
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WEDGE OF HIGH PRESSURE BECOMING ENTRENCHED ACROSS THE REGION
THIS AFTERNOON AS THE ASSOCIATED PARENT HIGH PROPAGATES INTO THE
NORTHEAST AND MID-ATLANTIC STATES. AS EXPECTED...ISENTROPIC ASSENT
HAS REMAINED QUITE WEAK AND MAINLY CONFINED TO THE 290K ISO-
SURFACE. THIS HAS RESULTED IN EXTENSIVE LOW CLOUDINESS ACROSS
MAINLY SOUTH COASTAL SOUTH CAROLINA WHERE SKIES HAVE BEEN CLOUDY
FOR A GOOD PORTION OF THE DAY. RECENT VISIBLE SATELLITE TRENDS
SUGGEST THE CLOUDS ARE BEGINNING BREAKING UP A BIT DURING MAXIMUM
HEATING...BUT EXPECT CLOUDS TO FILL BACK AFTER SUNSET AS MIXING
CEASES AND A WEAK DISTURBANCE APPROACHES FROM THE WEST.
THERE HAS BEEN NO RAIN SHOWER ACTIVITY NOTED TODAY AND EXPECT THIS
TREND TO PERSIST FOR MUCH OF THE NIGHT. HOWEVER...THE COMBINATION
OF WEAK ISENTROPIC LIFT AND SOME UVM INDUCED BY THE APPROACHING A
SOUTHERN STREAM STREAM SHORTWAVE MAY PROVIDE JUST ENOUGH DYNAMICS
TO PRODUCE SOME ISOLATED SHOWER ACTIVITY ACROSS PORTIONS OF THE
CHARLESTON TRI-COUNTY AREA JUST BEFORE SUNRISE SATURDAY.
CONFIDENCE IS QUITE LOW IN THIS SCENARIO AND ONLY A FEW OF THE
MODELS ARE SHOWING ANY QPF AT ALL...SO WILL PEAR BACK THE AREA OF
SLIGHT CHANCE POPS SLIGHTLY AND CONFINE THEM MAINLY TO AREAS
BOUNDED BY I-26 AND U.S. HIGHWAY 52.
LOWS WILL RANGE FROM THE LOWER 40S INLAND TO THE UPPER 40S/NEAR 50
AT THE COAST.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
SATURDAY...THE AREA WILL REMAIN SITUATED BETWEEN A WEDGE OF HIGH
PRESSURE OVER LAND AND A COASTAL TROUGH OFF THE SOUTHEAST COAST.
PRECIP CHANCES WILL REMAIN QUITE LOW OVER THE COURSE OF THE
DAY...BUT WE COULD SEE A FEW SHOWERS NORTH OF INTERSTATE 26 IN
CHARLESTON AND BERKELEY COUNTIES AS FORCING ASSOCIATED WITH A H5
SHORTWAVE AND H25 JET PASS ALOFT. ANY SHOWERS THAT DEVELOP WILL
LIKELY SHIFT OFFSHORE SATURDAY AFTERNOON AS MID/UPPER LVL FORCING
HEAD OVER THE WESTERN ATLANTIC. THE WEDGE OF HIGH PRESSURE IS THEN
EXPECTED TO GRADUALLY WEAKEN OVER THE SOUTHEAST SATURDAY EVENING AND
NIGHT WHILE THE PARENT CENTER OF HIGH PRESSURE SLIDES WELL OFF THE
NORTHEAST COAST. THE CHANGING PATTERN WILL LIKELY RESULT IN A
WARMING TREND LATE AS A MARGINAL DOWNSLOPING WIND COMPONENT DEVELOPS
OVER THE SOUTHEASTERN UNITED STATES AND CLOUD COVER DIMINISHES FROM
SOUTHWEST TO NORTHEAST. MID LVL RIDGING EXTENDING FROM THE GULF OF
MEXICO WILL ALSO CONTRIBUTE TO WARMING SFC TEMPS TO NEAR NORMAL FOR
THIS TIME OF YEAR. LATEST 1000-850 MB THICKNESSES FAVOR OVERALL HIGH
TEMPS IN THE LOW/MID 60S OVER MOST LOCATIONS...AND A FEW UPPER 60S
FOR LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA. OVERNIGHT
LOWS ARE EXPECTED TO RANGE IN THE LOW 40S INLAND TO MID/UPPER 40S
NEAR THE COAST.
SUNDAY...DRY WEATHER CONDITIONS UNDER MOSTLY SUNNY SKIES ARE
EXPECTED TO START OFF THE WEEK AS THE REMNANTS OF THE WEDGE ERODE
EARLY BEFORE ATLANTIC HIGH PRESSURE GRADUALLY SLIDES SOUTH ALONG THE
THE MID ATLANTIC AND SOUTHEAST COASTS. THE SHIFT IN HIGH PRESSURE
WILL ALLOW SFC WINDS TO VEER FROM NORTH/NORTHEAST TO SOUTH/SOUTHEAST
SUNDAY AFTERNOON...THUS FAVORING WARMER TEMPS AS WARM AIR ADVECTION
OCCURS OVER THE REGION WHILE MID LVL RIDGING EXPANDS FROM THE GULF
OF MEXICO. 1000-850 MB THICKNESSES SUGGEST OVERALL HIGH TEMPS IN THE
LOW TO MID 70S OVER MOST LOCATIONS...HIGHEST IN SOUTHEAST GEORGIA
AWAY FROM THE COAST. DESPITE CLEARING SKIES SUNDAY NIGHT...WARM
SOUTHERLY FLOW WILL KEEP OVERNIGHT LOWS IN THE LOW/MID 50S.
MONDAY...CHANCES OF SHOWERS WILL INCREASE THROUGHOUT THE DAY AS A
H5 SHORTWAVE QUICKLY ADVANCES TOWARD THE SOUTHEASTERN UNITED STATES
WHILE SOUTHERLY FLOW WARM TEMPS AND INCREASES MOISTURE AHEAD OF A
SFC COLD FRONT APPROACHING FROM THE WEST/NORTHEAST MONDAY EVENING.
SEVERAL OF THE MODELS INDICATE THAT THE FRONT WILL WEAKEN AS IT
APPROACHES THE AREA WITH LOW AMOUNTS OF QPF. HAVE THEREFORE
MAINTAINED ONLY A 20-40 POP SCHEME THROUGHOUT THE DAY WITH GREATEST
CHANCES OF PRECIP BEGINNING INLAND EARLY...THEN GRADUALLY MAKING WAY
TO THE COAST AS THE FRONT SHIFTS THROUGH THE AREA LATE. WE COULD SEE
GUSTY WINDS AHEAD OF THE COLD FRONT MONDAY AFTERNOON AS A 40-50 KT
LOW LVL JET PASSES OVER THE AREA WHILE TEMPS PEAK INTO THE MID
70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE QUICK MOVING COLD FRONT MENTIONED IN THE SHORT TERM PERIOD
SHOULD BE WELL EAST OF THE AREA BY MONDAY NIGHT WITH HIGH PRESSURE
BUILDING BACK NORTH OF THE REGION TUESDAY. THE SURFACE HIGH PRESSURE
HANGS ON AS A WEAK WEDGE WEDNESDAY. THE COOLEST DAY WILL BE
WEDNESDAY WITH MORNING LOWS IN THE MID 30S INLAND TO NEAR 40 COAST
AND HIGHS IN THE 50S TO NEAR 60. BY WEDNESDAY NIGHT...MODELS BEGIN
TO DIVERGE. THE MAIN FEATURE OF CONCERN WILL BE THE DEVELOPING STORM
SYSTEM IN THE SOUTHERN STREAM FLOW OVER TEXAS AND THE WESTERN GULF
OF MEXICO. THE GFS KEEPS THE UPPER WAVE WITH THIS SYSTEM
OPEN/PROGRESSIVE...WITH THE BEST CHANCES FOR WIDESPREAD SHOWERS/RAIN
LATE WEDNESDAY NIGHT THROUGH THURSDAY. THE ECMWF TRIES TO CLOSE THE
UPPER LOW OFF...RESULTING IN A SLOWER START TO THE PRECIP...ABOUT
6-12 HOURS...AND A MUCH SLOWER ENDING. IN FACT...THE ECMWF STILL HAS A
CLOSED UPPER LOW AND PRECIP CHANCES OVER THE REGION FRIDAY. HAVE
TRIED TO KEEP CONTINUITY WITH PREVIOUS FORECAST WHILE TRYING TO
BLEND/AVERAGE THE LATEST SOLUTIONS. FOR NOW...HAVE LOW END CHANCE
POPS LATE WEDNESDAY NIGHT...TO HIGH END CHANCE THURSDAY. TRENDED
POPS BACK DOWN BY FRIDAY...BUT KEPT SLIGHT CHANCE GIVEN SLOWER ECMWF
SOLUTION. THE LOW LEVELS WILL LIKELY BE DOMINATED BY A WEDGE OF
HIGH PRESSURE MUCH OF THE PERIOD...WHICH SHOULD HELP TO KEEP TEMPS
COOL/BELOW NORMAL.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
MARGINAL MVFR/VFR CIGS WILL LINGER THROUGH THE AFTERNOON...BEFORE
CIGS LOWER AS THE HIGH PRESSURE WEDGE BECOMES MORE FIRMLY
ESTABLISHED AND ISENTROPIC ASSENT INTENSIFIES. CIGS LOOK TO BOTTOM
OUT AT LOW-END MVFR AT BOTH TERMINALS BY LATE EVENING...ALTHOUGH
SOME GUIDANCE SUCH AS THE LATEST RAP SUGGEST IFR CIGS COULD
DEVELOP AFTER MIDNIGHT. CONFIDENCE IS NOT HIGH ENOUGH ATTM TO DROP
CIGS THAT LOW...BUT IT REMAINS A POSSIBILITY. CIGS WILL GRADUALLY
RETURN TO VFR BY MID-MORNING SATURDAY.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS/VSBYS WILL BE
POSSIBLE SATURDAY NIGHT AND EARLY SUNDAY AS HIGH PRESSURE WEDGES
INTO THE AREA. VFR CIGS/VSBYS ARE THEN ANTICIPATED SUNDAY AFTERNOON
THROUGH MONDAY MORNING. LOW TO MODERATE CHANCES OF MVFR CIGS/VSBYS
ARE POSSIBLE MONDAY AFTERNOON INTO MONDAY NIGHT DUE TO SHOWERS ALONG
A PASSING COLD FRONT. CIG/VSBY REDUCTIONS COULD OCCUR WITH AN
APPROACHING STORM SYSTEM AS EARLY AS WEDNESDAY NIGHT...BUT
CONFIDENCE REMAINS LOW IN THE TIMING OF THE EVENT DUE TO SEVERAL
MODEL INCONSISTENCIES.
&&
.MARINE...
TONIGHT...ELEVATED WINDS AND SEAS WILL CONTINUE TO AFFECT THE
COASTAL WATERS TONIGHT. THE HIGHEST WINDS LOOK TO OCCUR OVER THE
SOUTH CAROLINA COASTAL WATERS...WHERE SMALL CRAFT ADVISORIES
REMAIN IN EFFECT THROUGH THIS EVENING. REPORTS FROM THE CHARLESTON
HARBOR PILOT BOAT AS WELL AS A FEW OF THE C-MAN AND NEARSHORE
BUOYS SUGGEST WINDS ARE NEAR 20-25 KT WITH GUSTS TO 30 KT WHILE
FARTHER SOUTH ALONG THE BEAUFORT COUNTY COAST AND OVER THE GEORGIA
OFFSHORE WATERS GUSTS TO 25 KT ARE FAIRLY FREQUENT. SMALL CRAFT
ADVISORIES WILL REMAIN IN FOR FOR ALL LEGS EXCEPT THE GEORGIA
NEARSHORE WATERS AND THE CHARLESTON HARBOR. CONDITIONS WILL
IMPROVE OVERNIGHT...BUT ALL ZONES FALLING BELOW SMALL CRAFT
ADVISORY THRESHOLDS AFTER MIDNIGHT. SEAS WILL AVERAGE 5-7 FT OVER
THE ADVISORY AREA TO 3-5 FT ELSEWHERE.
SATURDAY THROUGH WEDNESDAY...WINDS/SEAS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS LATE WEEKEND INTO EARLY NEXT WEEK AS A
WEDGE OF HIGH PRESSURE ERODES INLAND ON SUNDAY AND A COASTAL TROUGH
LIFTS NORTH OF THE WATERS BY SUNDAY NIGHT. WINDS/SEAS WILL THEN
GRADUALLY INCREASE/BUILD ALONG THE WESTERN EDGE OF ATLANTIC HIGH
PRESSURE AS WINDS BECOME SOUTHERLY AHEAD OF A COLD FRONT APPROACHING
FROM THE WEST/NORTHWEST LATE MONDAY. WE COULD SEE MARGINAL SMALL
CRAFT ADVISORY LEVEL CONDITIONS MONDAY AFTERNOON/EVENING AS STRONG
LOW LVL WINDS SHIFT OVER THE WATERS AHEAD/ALONG THE COLD FRONT.
THERE WILL ALSO BE A LOW CHANCE OF SEA FOG DEVELOPING ON MONDAY AS
SFC DEWPTS APPROACH THE UPPER 50S OVER COOLER NEARSHORE WATERS.
THE COLD FRONT WILL MOVE THROUGH THE REGION MONDAY NIGHT WITH
MARGINAL SMALL CRAFT ADVISORY LEVEL CONDITIONS BEHIND THE FRONT ON
TUESDAY AS THE PRESSURE GRADIENT TRIES TO PINCH BETWEEN A WEDGE OF
HIGH PRESSURE INLAND AND LOWER PRESSURE OVER THE ATLANTIC. HIGH
PRESSURE WILL HOLD NORTH AND EAST OF THE REGION THROUGH WEDNESDAY
BUT WINDS/SEAS ARE EXPECTED TO STAY JUST BELOW SMALL CRAFT ADVISORY
LEVELS AT THIS POINT.
&&
.TIDES/COASTAL FLOODING...
TONIGHT...ELEVATED TIDES WILL AFFECT THE COASTAL AREAS WITH HIGH
TIDE THIS EVENING. CURRENT INDICATIONS ARE THAT TIDE LEVELS WILL
COME VERY CLOSE TO 7.0 FT MLLW IN THE CHARLESTON HARBOR...BUT THE
CURRENT THINKING IS THAT LEVELS WILL MORE LIKELY PEAK 6.8 TO 6.9
FT MLLW. WILL THEREFORE HOLD OFF ON HOISTING A COASTAL FLOOD
ADVISORY. HOWEVER...SOME SHALLOW COASTAL FLOODING WILL STILL
LIKELY OCCUR IN SOME OF THE NORMAL FLOOD PRONE AREAS OF DOWNTOWN
CHARLESTON...BUT THE FLOODING WILL BE VERY MINOR AT BEST. THE NEED
FOR AN ADVISORY WILL BE CONTINUOUSLY MONITORED THROUGHOUT THE
REST OF THE AFTERNOON AND EARLY EVENING AND ITS ISSUANCE CAN NOT
BE COMPLETELY RULED OUT.
SATURDAY...ASTRONOMICAL TIDE LEVELS WILL BE ELEVATED COMING OUT
OF THE PERIGEE THURSDAY...WITH A NEW MOON ON SATURDAY. A TIGHT
SURFACE PRESSURE GRADIENT WILL RESULT IN AN ENHANCED NORTHEAST
FLOW DURING SOME OF THIS TIME...AND WHEN COMBINED WITH THE ALREADY
ELEVATED ASTRONOMICAL TIDES...COULD RESULT IN SHALLOW COASTAL
FLOODING AT THE TIME OF HIGH TIDES TONIGHT AND SATURDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ352-
374.
SMALL CRAFT ADVISORY UNTIL 1 AM EST SATURDAY FOR AMZ350.
&&
$$
ST/DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1210 PM EST FRI FEB 28 2014
.SYNOPSIS...
A COASTAL TROUGH WILL DEVELOP JUST OFFSHORE TODAY AS A WEDGE OF HIGH
PRESSURE PUSHES SOUTHWARD INTO THE AREA...AND PERSISTS THROUGH LATE
SATURDAY. ATLANTIC HIGH PRESSURE WILL BECOME ESTABLISHED LATER THIS
WEEKEND AHEAD OF A COLD FRONT MOVING THROUGH BY MONDAY NIGHT. HIGH
PRESSURE WILL BUILD AGAIN NORTH OF THE REGION INTO THE MIDDLE OF
NEXT WEEK. A DEVELOPING STORM SYSTEM COULD AFFECT THE AREA WITH
WIDESPREAD RAINFALL BY LATE IN THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE FORECAST IS PRETTY MUCH ON TRACK. A WEDGE OF HIGH PRESSURE IS
STEADILY BUILDING INLAND THIS MORNING WITH SOME HINTS OF A COASTAL
TROUGH BEGINNING TO FORM ALONG THE WESTERN WALL OF THE GULF STREAM.
THE WEDGE WILL BECOME FURTHER ENTRENCHED ACROSS SOUTHEAST SOUTH
CAROLINA AND SOUTHEAST GEORGIA THROUGH THE DAY AS THE PARENT HIGH
SHIFTS INTO THE MID-ATLANTIC AND NORTHEAST STATES. WEAK ISENTROPIC
ASSENT NOTED ALONG THE 290K ISO-SURFACE WILL SUPPORT AN EXPANDING
STRATOCUMULUS DECK FROM OFF THE ATLANTIC.
CONDENSATION PRESSURE DEFICITS ARE PROGGED TO REMAIN ABOVE 50
NM...SO NO SHOWER ACTIVITY IS EXPECTED OVER LAND. HIGHS FROM THE
UPPER 50S NORTH TO THE LOWER 60S SOUTH WITH COOLER CONDITIONS AT
THE BEACHES LOOK REASONABLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
TONIGHT...A MID LEVEL SHORT WAVE TROUGH WILL APPROACH FROM THE
WEST...WHILE HIGH PRESSURE OVER NEW ENGLAND CONTINUES TO WEDGE
SOUTHWARD AT THE SURFACE WITH A COASTAL TROUGH LINGERING JUST
OFFSHORE. DEEPENING LOW LEVEL MOISTURE AND ENHANCED LIFT FROM THE
APPROACHING SHORT WAVE COULD RESULT IN ISOLATED SHOWERS MAINLY
LATE THIS EVENING AND OVERNIGHT ACROSS PORTIONS OF THE CHARLESTON
TRI-COUNTY AREA. ELSEWHERE...RAIN-FREE CONDITIONS ARE EXPECTED.
LOW STRATUS SHOULD BECOME RATHER EXTENSIVE ACROSS MUCH OF THE
AREA AS ABUNDANT MOISTURE REMAINS TRAPPED BENEATH A LOW LEVEL
INVERSION. THE COOL NORTHERLY FLOW WILL BE SOMEWHAT OFFSET BY THE
CLOUD COVER...YIELDING LOWS IN THE UPPER 30S TO AROUND 40 WELL
INLAND AND IN THE LOWER TO MID 40S CLOSER TO THE COAST.
ALL MODELS INDICATE THAT THE OVERALL UPPER LEVELS WILL BE
CHARACTERIZED BY A SPLIT FLOW. THERE WILL BE A NORTHERN/POLAR
STREAM THAT WILL REMAIN WELL NORTH OF THE AREA THROUGH THE
PERIOD...AND AN ACTIVE SOUTHERN STREAM...WHICH WILL AFFECT OUR
REGION ON MONDAY. TEMPERATURES START OFF BELOW NORMAL SATURDAY...
THEN MODERATE TO NEAR TO SLIGHTLY ABOVE NORMAL SUNDAY AND MONDAY.
SATURDAY...A WEAK UPPER LEVEL SHORTWAVE WILL BE DEPARTING THE
EXTREME NORTHERN FORECAST AREA WITH SLIGHT CHANCE OF PRECIP SATURDAY
MORNING. A WEDGE OF HIGH PRESSURE AT THE SURFACE WILL HANG ON
THROUGH THE DAY WITH LIGHT NNE LOW LEVEL FLOW AS A WEAK INVERTED
SURFACE TROUGH LIKELY FORMS OVER THE COASTAL WATERS. OTHER THAN LOW
CHANCES FOR PRECIP EARLY IN THE MORNING OVER THE NORTHER AREA...NOT
EXPECTING ANY SIGNIFICANT PRECIP. HOWEVER...WITH LOW LEVEL NNE FLOW
IN PLACE AND LIGHT WSW WINDS JUST ABOVE THE SURFACE...EXPECT CLOUDS
WILL BE SLOW TO CLEAR FROM SOUTH TO NORTH THROUGH THE DAY. THIS
WILL HELP KEEP HIGHS IN THE LOWER 60S NORTH...AND MID TO UPPER 60S
SOUTH BY LATE DAY. BY SATURDAY NIGHT...HIGH PRESSURE WILL SETTLE OVER
THE REGION. HOWEVER...PARTLY CLOUDY SKIES WILL HELP HOLD TEMPS IN
THE LOWER TO MID 40S MOST AREAS.
SUNDAY...THE SURFACE RIDGE MOVES EASTWARD INTO THE ATLANTIC. THIS
WILL ALLOW THE LOW LEVEL FLOW TO VEER FROM LIGHT ENE TO SE BY LATE
DAY. IN RESPONSE TO LOW LEVEL FLOW BECOMING SE AND A SLIGHT INCREASE
IN THE MID AND UPPER HEIGHTS...TEMPS WILL WARM INTO THE LOWER TO MID
70S. SUNDAY NIGHT...EXPECT MILD TEMPERATURES AS THE LOW LEVEL FLOW
INCREASES FROM THE SOUTH AHEAD OF A FAST APPROACHING COLD FRONT.
MOSTLY CLOUDY SKIES AND MIN TEMPS GENERALLY IN THE 50S.
MONDAY...A DAMPENING UPPER LEVEL TROUGH WILL BE MOVING BY TO THE
NORTH DURING THE DAY. MODELS INDICATE THAT THE ASSOCIATED SURFACE
COLD FRONT AND MOISTURE BAND WEAKEN AS IT MOVES TOWARD THE REGION.
HAVE KEPT LOW END CHANCE POPS WEST TO SLIGHT CHC POPS EXTREME EAST
FOR THE FIRST PART OF THE DAY...THEN LOW CHANCE POPS MOST OF THE
LAND AREA BY LATE DAY. THINK GIVEN THE DECREASING MOISTURE...WEAK
UPPER FORCING AND FAST MOTION OF THE FRONT...QPF VALUES SHOULD BE
GENERALLY LESS THAN ONE QUARTER INCH. DESPITE CLOUDS AND PRECIP
CHANCES...LOW LEVEL WSW FLOW SHOULD PUSH TEMPS BACK INTO THE LOWER
TO MID 70S.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE QUICK MOVING COLD FRONT MENTIONED IN THE SHORT TERM PERIOD
SHOULD BE WELL EAST OF THE AREA BY MONDAY NIGHT WITH HIGH PRESSURE
BUILDING BACK NORTH OF THE REGION TUESDAY. THE SURFACE HIGH PRESSURE
HANGS ON AS A WEAK WEDGE WEDNESDAY. THE COOLEST DAY WILL BE
WEDNESDAY WITH MORNING LOWS IN THE MID 30S INLAND TO NEAR 40 COAST
AND HIGHS IN THE 50S TO NEAR 60. BY WEDNESDAY NIGHT...MODELS BEGIN
TO DIVERGE. THE MAIN FEATURE OF CONCERN WILL BE THE DEVELOPING STORM
SYSTEM IN THE SOUTHERN STREAM FLOW OVER TEXAS AND THE WESTERN GULF
OF MEXICO. THE GFS KEEPS THE UPPER WAVE WITH THIS SYSTEM
OPEN/PROGRESSIVE...WITH THE BEST CHANCES FOR WIDESPREAD SHOWERS/RAIN
LATE WEDNESDAY NIGHT THROUGH THURSDAY. THE ECMWF TRIES TO CLOSE THE
UPPER LOW OFF...RESULTING IN A SLOWER START TO THE PRECIP...ABOUT
6-12 HOURS...AND A MUCH SLOWER ENDING. IN FACT...THE ECMWF STILL HAS A
CLOSED UPPER LOW AND PRECIP CHANCES OVER THE REGION FRIDAY. HAVE
TRIED TO KEEP CONTINUITY WITH PREVIOUS FORECAST WHILE TRYING TO
BLEND/AVERAGE THE LATEST SOLUTIONS. FOR NOW...HAVE LOW END CHANCE
POPS LATE WEDNESDAY NIGHT...TO HIGH END CHANCE THURSDAY. TRENDED
POPS BACK DOWN BY FRIDAY...BUT KEPT SLIGHT CHANCE GIVEN SLOWER ECMWF
SOLUTION. THE LOW LEVELS WILL LIKELY BE DOMINATED BY A WEDGE OF
HIGH PRESSURE MUCH OF THE PERIOD...WHICH SHOULD HELP TO KEEP TEMPS
COOL/BELOW NORMAL.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
MARGINAL MVFR/VFR CIGS WILL LINGER THROUGH THE AFTERNOON...BEFORE
CIGS LOWER AS THE HIGH PRESSURE WEDGE BECOMES MORE FIRMLY
ESTABLISHED AND ISENTROPIC ASSENT INTENSIFIES. CIGS LOOK TO BOTTOM
OUT AT LOW-END MVFR AT BOTH TERMINALS BY LATE EVENING...ALTHOUGH
SOME GUIDANCE SUCH AS THE LATEST RAP SUGGEST IFR CIGS COULD
DEVELOP AFTER MIDNIGHT. CONFIDENCE IS NOT HIGH ENOUGH ATTM TO DROP
CIGS THAT LOW...BUT IT REMAINS A POSSIBILITY. CIGS WILL GRADUALLY
RETURN TO VFR BY MID-MORNING SATURDAY.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CIGS/VSBYS WILL BE
POSSIBLE SATURDAY NIGHT AND EARLY SUNDAY AS HIGH PRESSURE WEDGES
INTO THE AREA. A QUICK MOVING COLD FRONT WILL BRING A WEAKENING
BAND OF SHOWERS ACROSS THE AREA LATE MONDAY AFTERNOON WITH A LOW
TO MODERATE CHANCE FOR MVFR CONDITIONS. AN APPROACHING STORM
SYSTEM LATER WEDNESDAY NIGHT AND THURSDAY IS EXPECTED TO BRING
CHANCES FOR MVFR OR LOWER CONDITIONS...ESPECIALLY THURSDAY AND
THURSDAY NIGHT. HOWEVER...SIGNIFICANT MODEL DIFFERENCES EXIST FOR
THIS STORM SYSTEM...WHICH HAS RESULTED IN LOWER CONFIDENCE IN THE
FORECAST LATER WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.MARINE...
TODAY AND TONIGHT...A BACKDOOR COLD FRONT WILL DROP ACROSS THE WATERS
THIS MORNING INTO EARLY THIS AFTERNOON...CAUSING WINDS TO VEER
NORTHEAST. CONDITIONS WILL THEN RAPIDLY DETERIORATE AS INLAND HIGH
PRESSURE WEDGES SOUTHWARD AND A COASTAL TROUGH DEVELOPS JUST
OFFSHORE IN RESPONSE. THE TIGHT SURFACE PRESSURE GRADIENT BETWEEN
THESE TWO FEATURES WILL RESULT IN WINDS SURGING UPWARDS OF 20 TO
25 KT ACROSS THE NEAR SHORE SC WATERS NORTH OF EDISTO AND 15 TO 20
KT MOST ELSEWHERE...WITH GUSTS TO 25 KT ACROSS CHARLESTON
HARBOR...THE REMAINING NEAR SHORE SC WATERS AND THE OUTER GEORGIA
WATERS. THESE CONDITIONS WILL LAST THROUGH MUCH OF TONIGHT...WITH
SOME IMPROVEMENT EXPECTED OVERNIGHT. SEAS WILL BUILD SIGNIFICANTLY
AS WELL IN RESPONSE TO THE PINCHED NORTHEAST FLOW. SMALL CRAFT
ADVISORIES ARE NOW IN EFFECT FOR CHARLESTON HARBOR AND ALL COASTAL
WATERS EXCEPT THE NEAR SHORE GEORGIA WATERS.
SATURDAY THROUGH WEDNESDAY...THE REGION WILL BE BETWEEN A WEDGE OF HIGH
PRESSURE INLAND AND A TROUGH OF LOW PRESSURE OVER THE ATLANTIC
WATERS SATURDAY AND SATURDAY NIGHT. BY SUNDAY....HIGH PRESSURE
BECOMES MORE ESTABLISHED OVER THE ATLANTIC WATERS...TURNING WINDS
TO SSE LATE. SUNDAY NIGHT AND MONDAY...LOW LEVEL WINDS WILL
INCREASE FROM THE SOUTH AHEAD OF AN APPROACHING COLD FRONT. COULD
SEE MARGINAL SCA CONDITIONS BY MONDAY. ALSO...GIVEN SOUTH-
SOUTHWEST FLOW...THERE WILL BE INCREASING CHANCES FOR SEA FOG
DURING MONDAY. MONDAY NIGHT...THE COLD FRONT MOVES THROUGH THE
REGION WITH MARGINAL SCA CONDITIONS BEHIND THE FRONT TUESDAY AS
THE PRESSURE GRADIENT TRIES TO PINCH BETWEEN THE WEDGE OF HIGH
PRESSURE INLAND AND LOWER PRESSURE OVER THE ATLANTIC. HIGH
PRESSURE WILL HOLD NORTH AND EAST OF THE REGION THROUGH
WEDNESDAY...BUT WINDS/SEAS EXPECTED TO STAY JUST BELOW SCA AT THIS
POINT.
&&
.TIDES/COASTAL FLOODING...
TONIGHT AND SATURDAY...ASTRONOMICAL TIDE LEVELS WILL BE ELEVATED
COMING OUT OF THE PERIGEE THURSDAY...WITH A NEW MOON ON SATURDAY.
A TIGHT SURFACE PRESSURE GRADIENT WILL RESULT IN AN ENHANCED
NORTHEAST FLOW DURING SOME OF THIS TIME...AND WHEN COMBINED WITH
THE ALREADY ELEVATED ASTRONOMICAL TIDES...COULD RESULT IN SHALLOW
COASTAL FLOODING AT THE TIME OF HIGH TIDES TONIGHT AND SATURDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ330-352.
SMALL CRAFT ADVISORY UNTIL 5 AM EST SATURDAY FOR AMZ350-374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1151 AM CST Fri Feb 28 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 355 AM CST FRI FEB 28 2014
Latest water vapor satellite loop at 08Z shows a compact
shortwave trough over southeast Colorado into the Texas Panhandle.
Regional radar showing precipitation breaking out from southern
Kansas south into Oklahoma. 00Z TOP and area soundings show quite
a bit of dry air in place. Initial precipitation will go into
moistening the column and forecast soundings from the RUC and NAM
suggest that this should start to occur between 12Z and 15Z when
precipitation should start making it to the ground. Initially
cooling to the wet bulb would give sleet at first then
transitioning over to all rain after 15Z, so not expecting much
ice accumulation this morning. Models are indicating good warm
advection today ahead of the arctic front which was just moving
into western North Dakota and Montana at 09Z. Mixing from 875 mb
today and factoring cloud cover will go lower than MOS temps with
highs in the lower to middle 40s.
Tonight the cold front will move south across the CWA with
temperatures falling back into the teens north to the middle 20s
southeast of Interstate 35. Chances of light rain will continue
early this evening as additional lift is expected as additional
shortwave energy moves through and also some low level frontogenetic
forcing along the cold front. precipitation still looks to be all
rain before ending early this evening, could not rule out a mix
along the Kansas and Nebraska border though.
.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CST FRI FEB 28 2014
Rapid pressure rises underway in eastern Montana this morning with
surface temps near -30 F in central Manitoba and Saskatchewan with
water vapor showing northerlies over it. To the west, rather potent
upper low making eastward progress toward California with one
stronger embedded wave nearing the coast at 08Z. Although modifying
with time, these features come together over the Central Plains this
weekend for a potential winter storm.
Overall setup hasn`t changed a lot, but model differences remain
rather large in smaller scale features, leaving confidence much
lower than that in the days preceding the heavy snow event of early
this month. Differences throughout the troposphere in temperature
and moisture profiles as well as upper energy moving through, the
location and duration of frontogenesis, and the sharpness and
intensity of the warm nose lead the list of potential pitfalls to
how this storm plays out. 0Z models range from the slow NAM to the
fast ECMWF with GEM and GFS in between. The NAM and GFS are more
robust with the aforementioned lead wave passing just north Saturday
evening and then slower with the larger scale wave Sunday, with the
GEM and ECMWF opposing these ideas.
Still looking like much of Saturday will be spent moistening the mid
levels, but by late morning low level isentropic lift may be enough
for freezing drizzle and flurries to be generated. Chances for
measurable amounts increase quickly late in the day, though the NAM
and GFS would suggest a break overnight behind the lead wave. In
either event, fast mid level flow will bring the potential for
longer lived frontogenetic bands under CSI or perhaps brief CI in
the snow growth zone. Upper lift then picks up for much of Sunday as
the main wave passes. Didn`t alter precipitation types much given
uncertainty in the details of the warm nose and how saturated it may
be for at least early in the event. This still keeps the heavier
snow in the northern to central portions of the area with moderate
ice accumulations from freezing rain in the south, and periods of
sleet for most locations. Still not looking like a major ice event
in the very cold low levels and 850 mb front staying well south.
Overall trends suggested a bit stronger wind speeds and colder
temps, giving some concern for blowing snow and hazardous wind chills
as well. Actual air temps should fall to around record levels for both
highs and lows into Monday.
Zonal flow takes hold for the remainder of the forecast resulting in
moderating temps. Some decent agreement with a longer wavelength
trough passing around Wednesday though moisture values likely quite
limited for only light precip opportunities.
&&
.AVIATION...(For the 18Z TAFs through 18Z Saturday Afternoon)
Issued at 1138 AM CST FRI FEB 28 2014
Rain showers have held off to the south this morning. It appears
that any chance of rain will come along and behind a passing
front. Temperatures initially will be warm enough for rain although
quickly cooling for maybe a brief snow shower. The precipitation
should remain light. Freezing drizzle could persist into the night
changing over to flurries in the early morning hours which would
increase the chances of IFR ceilings. It does appear that MVFR
ceilings are more likely overnight and into tomorrow.
&&
.CLIMATE...
Issued at 1138 AM CST FRI FEB 28 2014
Record lowest minimum and lowest maximum temperatures...
March 1 March 2 March 3 Any Day in March
Topeka -1/18 -3/14 -1/16 -7/9
Concordia -2/15 -4/15 -6/12 -11/8
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH from Saturday evening through late Sunday
night FOR KSZ008>012-020>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...53
LONG TERM...65
AVIATION...Sanders
CLIMATE...65
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 PM EST FRI FEB 28 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 341 PM EST FRI FEB 28 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ARCTIC BRANCH WNW
FLOW ALF OVER THE UPR LKS TO THE S OF CORE OF ARCTIC AIRMASS/CLOSED
LO CENTERED OVER SRN HUDSON BAY. 12Z H5 TEMP WAS AS LO AS AN
IMPRESSIVE -50C OVER NRN QUEBEC...AND -30C OR LOWER H85 TEMPS WERE
PRESENT WITHIN THE CORE OF COLDEST AIR. A FAIRLY STRONG SHRTWV
EMBEDDED IN THE ARCTIC BRANCH IS CURRENTLY JUST W OF LK WINNIPEG...
WITH SUPPORTING AXIS OF STRONGER H3 WINDS AOA 100KT STRETCHING FM
JUST S OF THE SHRTWV ACRS THE UPR LKS INTO NEW ENGLAND. SOME
ENHANCED CLDS ARE PRESENT OVER THE NRN PLAINS INTO MN IN WHAT
APPEARS TO BE THE RRQ OF SPEED MAX SUPPORTING THE LK WINNIPEG
SHRTWV. THIS AREA IS ALSO EXPERIENCING GENERAL WAD/ISENTROPIC ASCENT
IN THE SW FLOW AHEAD OF ACCOMPANYING H85 LO CENTER JUST S OF LK
WINNIPEG. DESPITE QUITE A BIT OF VERY DRY LLVL AIR SHOWN ON LOCAL
12Z RAOBS...H925 DEWPT DEPRESSION WAS AS HI AS 26C AT MPX AT 12Z...
SOME PATCHY LGT SN HAS BROKEN OUT OVER NE MN WHERE LATEST RUC
ANALYSIS INDICATES SHARPER ISENTROPIC ASCENT/MOISTENING ON THE
270-280K SFCS /ABOUT H85-7/. DESPITE WHAT APPEARS TO BE FAIRLY
EXTENSIVE ICE COVER ON VSBL STLT IMAGE OVER THE N PORTION OF LK
MI...A BAND OF -SHSN IN THE LLVL SSW WIND UP THE LENGTH OF LK MOVED
AS FAR N AS INTO MANISTIQUE BY LATE IN THE MRNG. ANOTHER BAND OF SN
UNDER AXIS OF SHARPER MID LVL FGEN IS STREAKING ENEWD THRU WI TOWARD
SCENTRAL UPR MI. OTRW...SFC TEMPS OVER UPR MI HAVE RECOVERED ABV
ZERO FM THE RECORD COLD OBSVD THIS MRNG DESPITE THE THICKENING WAD
CLDS. THE LOWEST TEMP REPORTED WAS -41F AT NEWBERRY CITY.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE SN TRENDS/POPS/GOING
HEADLINES ASSOCIATED WITH SHRTWV/SFC LO NOW NEAR LK WINNIPEG. FOCUS
FOR LATER TNGT INTO SAT TURNS TO TEMPS ONCE DRIER AIR RETURNS ALF
AND ENDS THE PCPN. PER NCEP GUIDANCE AND ITS CONSISTENT HANDLING OF
APRCHG DISTURBANCE...GENERALLY FOLLOWED THE 12Z GFS FOR FCST PREP.
LATE THIS AFTN/TNGT...AREA OF DEEP LYR QVECTOR CNVGC/ISENTROPIC
ASCENT ASSOCIATED WITH UPSTREAM SHRWTV IS FCST TO OVERSPREAD THE UPR
LKS BY THIS EVNG BEFORE PUSHING OFF TO THE EAST AFT MIDNGT WITH
VIGOROUS MID LVL DRYING/DEEP LYR QVECTOR DVGC FOLLOWING. EXPECT THE
PATCHY LGT SN IN NRN MN EARLY THIS AFTN TO OVERSPREAD MOST OF UPR MI
BY LATE AFTN. MODELS CONTINUE TO INDICATE THE WAD PCPN WL BE
ENHANCED A BIT BY SOME UPR DVGC IN RRQ OF 120KT H3 JET MAX THAT IS
SUPPORTING THE ENHANCED CLDS NOW OVER MN AND WHICH WL BE STREAKING
EWD ACRS LK SUP AND INTO SE ONTARIO AFTER 00Z. LOOKS LIKE THE
HEAVIEST PCPN WL FALL OVER THE SE HALF OF THE CWA CLOSER TO AXIS OF
SHARPEST MID LVL FGEN AND WHERE THERE WL BE SOME ENHANCEMENT WITH
LLVL SSW FLOW UP THE LENGTH OF LK MI...INCLUDING THE OPEN WATERS S
OF THE LATITUDE OF MENOMINEE WHERE LES BAND WAS QUITE APRNT ON VSBL
STLT IMAGERY BEFORE THE ARRIVAL OF HIER CLDS OBSCURED THIS FEATURE.
THE ARRIVAL OF THE MID LVL DRYING/DEEP LYR QVECTOR DVGC WL END
OVERALL LIGHTER PCPN OVER THE W EARLY THIS EVNG AND OVER THE E SOON
AFT 06Z. AS FOR SN TOTALS...H7 SPECIFIC HUMIDITY IS FCST TO INCRS TO
1.5-2.0 G/KG OVER THE SE CWA AT 00Z. WITH A 6HR PERIOD OF SYNOPTIC
SN AT MOST LOCATIONS...THAT WOULD EQUATE TO UP TO 2 INCHES OF ACCUM.
BUT FCST SDNGS CONT TO EXHIBIT A DEEP DGZ THAT IS 10K FT OR EVEN
DEEPER. WITH FVRBL SN/WATER RATIOS THAT MAY BE AS HI AS 25-30:1...
EXPECT UP TO 4 INCHES SN TOTAL OVER MUCH OF THE SE CWA WHERE DYNAMIC
SUPPORT WL BE GREATEST. WITH SOME ENHANCEMENT OFF LK MI THAT MIGHT
ADD AN ADDITIONAL INCH OR 2 TO THE SN TOTALS...GOING ADVYS FOR
DELTA/SRN SCHOOLCRAFT COUNTIES STILL SEEM ON TARGET. AFTER THE PCPN
ENDS...A DVLPG NW FLOW IN THE WAKE OF THE SFC LO CENTER TRACKING
ACRS LK SUP WL ADVECT COLDER AIR BACK INTO THE UPR LKS...DROPPING
H85 TEMPS TO ARND -25C OVER THE NW BY 12Z SAT. WITH EXTENSIVE ICE
COVER ON LK SUP...ANY LK EFFECT SHSN IN THE NW WIND SN BELTS SHOULD
BE NO MORE THAN ISOLD. SO MAINTAINED ONLY SCHC POPS IN THESE
LOCATIONS. THE REST OF THE CWA WL BE DRY AFT THE EVNG PCPN EXITS.
ONE CONCERN IS THE POTENTIAL FOR ADVY LVL WIND CHILLS OVER THE W
LATER ON. PREFER THE SOMEWHAT STRONGER WINDS SHOWN BY THE FAVORED
GFS...WHICH HAS CONSISTENTLY SHOWN A DEEPER SFC LO TRACKING ACRS LK
SUP. BUT EVEN THE HIER GFS NW WINDS AND FCST MIN TEMPS CLOSE TO -10F
OVER THE W RESULT IN ONLY MARGINAL WIND CHILLS NEAR -25F LATE TNGT
INTO SAT MRNG. SO OPTED TO HOLD OFF ON ADVY FOR NOW.
SAT...THE CWA WL BE DOMINATED BY COLD...ACYC NW FLOW E OF ARCTIC HI
PRES BLDG INTO THE NRN PLAINS. H85 TEMPS ON SAT ARE FCST TO FALL TO
-29C OVER THE NW TO -25C OVER THE SE CWA BY 00Z SUN. OVERALL ACYC
FLOW AND NEAR ABSENCE OF OPEN WATER OVER LK SUP SHOULD RESTRICT LES
POPS TO NO HIER THAN LO CHC. GUSTY NW WINDS WITH UNSTABLE LLVL LAPSE
RATES UP TO INVRN BASE NEAR H85 WL ALLOW FOR SOME BLSN MAINLY IN
OPEN AREAS NEAR LK SUP DOWNWIND OF SNOW COVERED ICE THAT HAVE BEEN
PLAGUED BY THESE EVENTS THRU THIS COLD WINTER. BUT SINCE LTL IF ANY
SN WL BE FALLING...SUSPECT THERE WL BE NO SGNFT ISSUES. GIVEN THE
ANOMALOUSLY COLD H85 TEMPS...TENDED TOWARD THE LOWER END OF GUIDANCE
FOR MAX TEMPS...WHICH ARE SUPPORTED BY MIXING TO H85 ON THE GFS FCST
SDNGS. WITH DISTURBANCE STREAKING E TOWARD THE LOWER LKS...NOT OUT
OF THE QUESTION THE NRN FRINGE OF -SN SHIELD COULD BRUSH THE FAR
SCNTRL LATE IN THE DAY. RETAINED SCHC POPS THERE.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 436 PM EST FRI FEB 28 2014
BY EARLY NEXT WEEK...MODELS POINT TOWARD A BREAK IN THE HIGHLY
AMPLIFIED WEST COAST/ERN PACIFIC RIDGE AND BROAD DOWNSTREAM TROUGH
PATTERN WHICH HAS CHARACTERIZED MUCH OF OUR RECORD COLD WINTER.
MODELS INDICATE THAT THE NRN END OF THE WRN RIDGE IS FCST TO CLOSE
OFF AND RETROGRADE TO SIBERIA...ALLOWING PACIFIC FLOW TO STRENGTHEN
INTO THE CONUS. THIS WILL BRING ABOUT A SLOW MODERATION IN TEMPS FOR
NEXT WEEK. HOWEVER...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A
TENDENCY FOR SOME DEGREE OF WRN RIDGING WHICH SHOULD ENSURE
GENERALLY BELOW NORMAL TEMPS PERSIST ACROSS UPPER MI FOR THE FIRST
COUPLE OF WEEKS OF MARCH. SYNOPTIC PCPN APPEARS TO BE MININAL IN
THIS PATTERN WITH THE BEST CHANCE FOR PCPN MID TO LATE WEEK AS A
SERIES OF SHORTWAVES MOVE ONSHORE FROM THE PACIFIC AND TRACK E
ACROSS THE NRN CONUS IN A MORE LOWER AMPLITUDE MORE PROGRESSIVE
FLOW. LINGERING COLD AIRMASS FOR LATE THIS WEEKEND INTO EARLY NEXT
WEEK WOULD NORMALLY RESULT IN LES OFF LAKE SUPERIOR IN NW FLOW...
BUT GIVEN NEAR 100PCT ICE COVER...LES MAY BE SHUTDOWN THRU THIS FCST
PERIOD.
SAT NIGHT INTO MONDAY...A HIGH PRES RIDGE STRETCHING FROM THE SFC
HIGH CENTER OVER THE NRN PLAINS INTO THE UPPER LAKES WILL ENSURE A
PERIOD OF DRY...BUT STILL VERY COLD WEATHER SAT NIGHT INTO SUNDAY
NIGHT. FORECASTING TEMPS WILL BE A CHALLENGE FOR SAT NIGHT INTO
EARLY NEXT WEEK AS MIN TEMPS COULD BE VERY COLD EACH NIGHT (WELL BLO
LOWEST GUIDANCE) UNDER LINGERING BUT GRADUALLY MODERATING ARCTIC AIR
MASS. HIGH CLOUDS ON THE NRN FRINGE OF DISTURBANCE PASSING TO THE S
OF THE AREA MAY LIMIT COOLING SOME SAT NIGHT. OTHERWISE...CLOUD
COVER MAY NOT BE THAT MUCH OF AN ISSUE THRU EARLY NEXT WEEK AS
BUILDING HIGH PRESSURE SHOULD ENSURE MOSTLY CLEAR SKIES AND THERE
SHOULD BE LITTLE IF ANY STRATOCU OFF WHAT SHOULD BE A TOTALLY ICE
COVERED LAKE SUPERIOR. EXPECT WINDS TO BE MOSTLY LIGHT EACH NIGHT AS
SFC HIGH PRES DOMINATES SO WILL CONTINUE TO FAVOR MIN TEMPS
GENERALLY AT OR BLO THE LOWEST GUIDANCE SAT NIGHT AND SUN
NIGHT...ESPECIALLY FOR TRADITIONAL COLD SPOTS. WITH MODELS TRENDING
FARTHER SOUTH WITH SHORTWAVE NOW FCST TO MOVE THROUGH THE NORTHERN
PLAINS AND LOWER MIDWEST...CLOUDS MAY NOT BE AS MUCH OF A FACTOR AS
PREV THOUGHT SO HAVE TRENDED COLDER WITH MIN TEMPS FOR MON
NIGHT...CLOSER TO GEM-NH BIAS CORRECTED VALUES. INCREASINGLY
HIGHER SUN ANGLE AT THIS TIME OF YEAR WORKING ON LOWER ALBEDO
FORESTED TERRAIN WILL HELP TEMPS REBOUND INTO THE SINGLE DIGITS AND
LOWER TEENS ABOVE ZERO FROM FRIGID OVERNIGHT LOWS EACH DAY...THOUGH
MAX TEMPS WILL STILL BE WELL BLO NORMAL.
12Z MODELS NOW SHOWING BIGGER DISCREPANCIES FOR MID TO LATE NEXT
WEEK. BOTH THE GEM-NH AND ECMWF AND TO A LESSER EXTENT THE UKMET
SHOW A SHORTWAVE ROTATING DOWN FM HUDSON BAY BRINGING ANOTHER PUSH
OF ARCTIC AIR INTO THE REGION. THE GEM-NH IS DEEPER AND SLOWER WITH
THIS FEATURE THAN THE ECMWF AND EVENTUALLY FORMS A CLOSED LOW BY 12Z
THU OVER THE WRN GREAT LAKES. MEANWHILE THE GFS SHOWS THIS SHORTWAVE
STAYING WELL NE AND NOT IMPACTING THE GREAT LAKES. GIVEN
UNCERTAINTY...FEEL INCLINED TO FOLLOW ALONG WITH THE ECMWF WHICH IS
MORE OF A COMPROMISE BETWEEN THE GFS AND MORE EXTREME GEM-NH SOLN.
THIS WILL KEEP MORE OF AN ARCTIC AIRMASS OVER THE AREA FOR ONE MORE
DAY WITH DOUBLE DIGIT BELOW ZERO TEMPS POSSIBLE AGAIN ON TUE NIGHT
BEFORE AIRMASS BEGINS TO MODERATE ON WEDNESDAY. MODELS STILL SHOW A
PACIFIC SHORTWAVE COMING INTO THE AREA TOWARD THE END OF THE WEEK
WITH SIGNIFICANT TIMING ISSUES. THE GFS IS MUCH MORE PROGRESSIVE
BRINGING THE SHORTWAVE AND ASSOC FRONT THROUGH THU AFTERNOON AND
EVENING WHILE THE ECMWF DOES NOT BRING IT THROUGH UNTIL LATE THU
NIGHT AND FRI. FOR NOW WILL FOLLOW CONSENSUS MODEL GUIDANCE RESULTING
IN 30 TO 40 PCT POPS FOR LIGHT SNOW MAINLY THU NIGHT INTO FRI. TEMPS
BY THE END OF THE WEEK WILL MODERATE INTO THE 20S AND MAY EVEN
APPROACH 30F AT A FEW SITES ALONG THE WI BORDER. &&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM EST FRI FEB 28 2014
EXPECT VFR CONDITIONS EARLY IN THE FCST PERIOD TO GIVE WAY TO MVFR
CONDITIONS BY MID/LATE AFTN AS AREA OF -SN ASSOCIATED WITH LO PRES
MOVING THRU NW MN OVERSPREADS UPR MI. BEST CHC FOR SOMEWHAT HEAVIER
SN/IFR VSBYS WL BE AT SAW TOWARD 00Z...CLOSER TO WHEN BETTER DYNAMIC
SUPPORT IS FCST TO IMPACT SCENTRAL UPR MI. THE ARRIVAL OF DRIER AIR
ALF WL END THE PCPN W-E THIS EVNG...BUT EXPECT PREDOMINANT MVFR CIGS
TO LINGER THRU SAT MRNG AT IWD/CMX WITH STEADY...UPSLOPE NW FLOW OF
COLDER AIR. EXTENSIVE ICE COVER OVER LK SUP WL LIMIT THE POTENTIAL
FOR HEAVIER LES THAT WOULD NORMALLY BE A PROBLEM AT THESE LOCATIONS.
DOWNSLOPE NATURE OF THE NW FLOW SHOULD RESULT IN A TREND TOWARD VFR
CONDITIONS AT SAW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 436 PM EST FRI FEB 28 2014
EXPECT S WINDS UP TO 20-25 KTS AHEAD OF LO PRES CROSSING LAKE
SUPERIOR THIS EVENING TO SHIFT TO THE NW LATE TONIGHT ONCE THE LO
SHIFTS INTO SE ONTARIO AND THEN INCREASE UP TO 25-30 KTS INTO SAT
UNDER SHARPENING PRES GRADIENT BETWEEN THE DEPARTING LO AND HI PRES
BUILDING INTO THE NORTHERN PLAINS. A RIDGE BUILDING ACROSS THE GREAT
LAKES FROM THE N PLAINS AND S CENTRAL CANADA SATURDAY THROUGH MONDAY
WILL ENSURE LIGHT WINDS. HIGH PRESSURE AND GENERALLY LIGHT WINDS WILL
CONTINUE TO DOMINATE THE UPPER GREAT LAKES INTO THE MIDDLE OF NEXT
WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...KC
MARINE...KC/VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
342 PM EST FRI FEB 28 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 341 PM EST FRI FEB 28 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW ARCTIC BRANCH WNW
FLOW ALF OVER THE UPR LKS TO THE S OF CORE OF ARCTIC AIRMASS/CLOSED
LO CENTERED OVER SRN HUDSON BAY. 12Z H5 TEMP WAS AS LO AS AN
IMPRESSIVE -50C OVER NRN QUEBEC...AND -30C OR LOWER H85 TEMPS WERE
PRESENT WITHIN THE CORE OF COLDEST AIR. A FAIRLY STRONG SHRTWV
EMBEDDED IN THE ARCTIC BRANCH IS CURRENTLY JUST W OF LK WINNIPEG...
WITH SUPPORTING AXIS OF STRONGER H3 WINDS AOA 100KT STRETCHING FM
JUST S OF THE SHRTWV ACRS THE UPR LKS INTO NEW ENGLAND. SOME
ENHANCED CLDS ARE PRESENT OVER THE NRN PLAINS INTO MN IN WHAT
APPEARS TO BE THE RRQ OF SPEED MAX SUPPORTING THE LK WINNIPEG
SHRTWV. THIS AREA IS ALSO EXPERIENCING GENERAL WAD/ISENTROPIC ASCENT
IN THE SW FLOW AHEAD OF ACCOMPANYING H85 LO CENTER JUST S OF LK
WINNIPEG. DESPITE QUITE A BIT OF VERY DRY LLVL AIR SHOWN ON LOCAL
12Z RAOBS...H925 DEWPT DEPRESSION WAS AS HI AS 26C AT MPX AT 12Z...
SOME PATCHY LGT SN HAS BROKEN OUT OVER NE MN WHERE LATEST RUC
ANALYSIS INDICATES SHARPER ISENTROPIC ASCENT/MOISTENING ON THE
270-280K SFCS /ABOUT H85-7/. DESPITE WHAT APPEARS TO BE FAIRLY
EXTENSIVE ICE COVER ON VSBL STLT IMAGE OVER THE N PORTION OF LK
MI...A BAND OF -SHSN IN THE LLVL SSW WIND UP THE LENGTH OF LK MOVED
AS FAR N AS INTO MANISTIQUE BY LATE IN THE MRNG. ANOTHER BAND OF SN
UNDER AXIS OF SHARPER MID LVL FGEN IS STREAKING ENEWD THRU WI TOWARD
SCENTRAL UPR MI. OTRW...SFC TEMPS OVER UPR MI HAVE RECOVERED ABV
ZERO FM THE RECORD COLD OBSVD THIS MRNG DESPITE THE THICKENING WAD
CLDS. THE LOWEST TEMP REPORTED WAS -41F AT NEWBERRY CITY.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE SN TRENDS/POPS/GOING
HEADLINES ASSOCIATED WITH SHRTWV/SFC LO NOW NEAR LK WINNIPEG. FOCUS
FOR LATER TNGT INTO SAT TURNS TO TEMPS ONCE DRIER AIR RETURNS ALF
AND ENDS THE PCPN. PER NCEP GUIDANCE AND ITS CONSISTENT HANDLING OF
APRCHG DISTURBANCE...GENERALLY FOLLOWED THE 12Z GFS FOR FCST PREP.
LATE THIS AFTN/TNGT...AREA OF DEEP LYR QVECTOR CNVGC/ISENTROPIC
ASCENT ASSOCIATED WITH UPSTREAM SHRWTV IS FCST TO OVERSPREAD THE UPR
LKS BY THIS EVNG BEFORE PUSHING OFF TO THE EAST AFT MIDNGT WITH
VIGOROUS MID LVL DRYING/DEEP LYR QVECTOR DVGC FOLLOWING. EXPECT THE
PATCHY LGT SN IN NRN MN EARLY THIS AFTN TO OVERSPREAD MOST OF UPR MI
BY LATE AFTN. MODELS CONTINUE TO INDICATE THE WAD PCPN WL BE
ENHANCED A BIT BY SOME UPR DVGC IN RRQ OF 120KT H3 JET MAX THAT IS
SUPPORTING THE ENHANCED CLDS NOW OVER MN AND WHICH WL BE STREAKING
EWD ACRS LK SUP AND INTO SE ONTARIO AFTER 00Z. LOOKS LIKE THE
HEAVIEST PCPN WL FALL OVER THE SE HALF OF THE CWA CLOSER TO AXIS OF
SHARPEST MID LVL FGEN AND WHERE THERE WL BE SOME ENHANCEMENT WITH
LLVL SSW FLOW UP THE LENGTH OF LK MI...INCLUDING THE OPEN WATERS S
OF THE LATITUDE OF MENOMINEE WHERE LES BAND WAS QUITE APRNT ON VSBL
STLT IMAGERY BEFORE THE ARRIVAL OF HIER CLDS OBSCURED THIS FEATURE.
THE ARRIVAL OF THE MID LVL DRYING/DEEP LYR QVECTOR DVGC WL END
OVERALL LIGHTER PCPN OVER THE W EARLY THIS EVNG AND OVER THE E SOON
AFT 06Z. AS FOR SN TOTALS...H7 SPECIFIC HUMIDITY IS FCST TO INCRS TO
1.5-2.0 G/KG OVER THE SE CWA AT 00Z. WITH A 6HR PERIOD OF SYNOPTIC
SN AT MOST LOCATIONS...THAT WOULD EQUATE TO UP TO 2 INCHES OF ACCUM.
BUT FCST SDNGS CONT TO EXHIBIT A DEEP DGZ THAT IS 10K FT OR EVEN
DEEPER. WITH FVRBL SN/WATER RATIOS THAT MAY BE AS HI AS 25-30:1...
EXPECT UP TO 4 INCHES SN TOTAL OVER MUCH OF THE SE CWA WHERE DYNAMIC
SUPPORT WL BE GREATEST. WITH SOME ENHANCEMENT OFF LK MI THAT MIGHT
ADD AN ADDITIONAL INCH OR 2 TO THE SN TOTALS...GOING ADVYS FOR
DELTA/SRN SCHOOLCRAFT COUNTIES STILL SEEM ON TARGET. AFTER THE PCPN
ENDS...A DVLPG NW FLOW IN THE WAKE OF THE SFC LO CENTER TRACKING
ACRS LK SUP WL ADVECT COLDER AIR BACK INTO THE UPR LKS...DROPPING
H85 TEMPS TO ARND -25C OVER THE NW BY 12Z SAT. WITH EXTENSIVE ICE
COVER ON LK SUP...ANY LK EFFECT SHSN IN THE NW WIND SN BELTS SHOULD
BE NO MORE THAN ISOLD. SO MAINTAINED ONLY SCHC POPS IN THESE
LOCATIONS. THE REST OF THE CWA WL BE DRY AFT THE EVNG PCPN EXITS.
ONE CONCERN IS THE POTENTIAL FOR ADVY LVL WIND CHILLS OVER THE W
LATER ON. PREFER THE SOMEWHAT STRONGER WINDS SHOWN BY THE FAVORED
GFS...WHICH HAS CONSISTENTLY SHOWN A DEEPER SFC LO TRACKING ACRS LK
SUP. BUT EVEN THE HIER GFS NW WINDS AND FCST MIN TEMPS CLOSE TO -10F
OVER THE W RESULT IN ONLY MARGINAL WIND CHILLS NEAR -25F LATE TNGT
INTO SAT MRNG. SO OPTED TO HOLD OFF ON ADVY FOR NOW.
SAT...THE CWA WL BE DOMINATED BY COLD...ACYC NW FLOW E OF ARCTIC HI
PRES BLDG INTO THE NRN PLAINS. H85 TEMPS ON SAT ARE FCST TO FALL TO
-29C OVER THE NW TO -25C OVER THE SE CWA BY 00Z SUN. OVERALL ACYC
FLOW AND NEAR ABSENCE OF OPEN WATER OVER LK SUP SHOULD RESTRICT LES
POPS TO NO HIER THAN LO CHC. GUSTY NW WINDS WITH UNSTABLE LLVL LAPSE
RATES UP TO INVRN BASE NEAR H85 WL ALLOW FOR SOME BLSN MAINLY IN
OPEN AREAS NEAR LK SUP DOWNWIND OF SNOW COVERED ICE THAT HAVE BEEN
PLAGUED BY THESE EVENTS THRU THIS COLD WINTER. BUT SINCE LTL IF ANY
SN WL BE FALLING...SUSPECT THERE WL BE NO SGNFT ISSUES. GIVEN THE
ANOMALOUSLY COLD H85 TEMPS...TENDED TOWARD THE LOWER END OF GUIDANCE
FOR MAX TEMPS...WHICH ARE SUPPORTED BY MIXING TO H85 ON THE GFS FCST
SDNGS. WITH DISTURBANCE STREAKING E TOWARD THE LOWER LKS...NOT OUT
OF THE QUESTION THE NRN FRINGE OF -SN SHIELD COULD BRUSH THE FAR
SCNTRL LATE IN THE DAY. RETAINED SCHC POPS THERE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 508 AM EST FRI FEB 28 2014
CURRENT PATTERN IS HIGHLY AMPLIFIED WITH A STRONG RIDGE EXTENDING N
THRU AK/YUKON AND A DEEP TROF DOWNSTREAM OVER MUCH OF CANADA INTO
THE ADJACENT CONUS...A PATTERN THAT HAS FREQUENTLY BEEN OBSERVED
THIS COLD SEASON. ASSOCIATED WITH THE TROF...A BITTERLY COLD AIR
MASS WITH MAGNITUDE VERY UNUSUAL FOR SO LATE IN THE SEASON WILL
LINGER INTO THE WEEKEND. THEN...SIMILAR TO THE LAST OCCURRENCE OF
THIS HIGHLY AMPLIFIED PATTERN...THE NRN END OF THE WRN RIDGE IS
STILL FCST TO CLOSE OFF AND RETROGRADE TO SIBERIA...ALLOWING PACIFIC
FLOW TO STRENGTHEN INTO THE CONUS. THIS WILL BRING SLOW MODERATION
NEXT WEEK. HOWEVER...MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A
TENDENCY FOR SOME DEGREE OF WRN RIDGING WHICH SHOULD ENSURE BELOW
NORMAL TEMPS MOSTLY PREVAIL ACROSS UPPER MI FOR THE NEXT COUPLE OF
WEEKS. WITH SOME PERIODS OF LIGHT WINDS OVER THE COMING DAYS...THE
LINGERING COLD AIR MASS SHOULD FINALLY PUSH LAKE SUPERIOR TO 100PCT
ICE COVER. MAY REACH THAT THIS MORNING DUE TO THE CURRENT LIGHT WIND
REGIME. FAST LOOPING OF YESTERDAYS VIS SATELLITE IMAGERY CLEARLY
SHOWED ICE GROWING IN THE REMAINING OPEN WATER AREAS. AS WOULD BE
EXPECTED...PATTERN IS NOT REALLY FAVORABLE FOR MUCH IN THE WAY OF
SYNOPTIC PCPN. HOWEVER...THERE ARE SOME INDICIATIONS FROM MEDIUM
RANGE GUIDANCE FOR POTENTIALLY A LITTLE MORE ACTION MID AND LATE
NEXT WEEK AS A SERIES OF SHORTWAVES SWEEP ONSHORE OFF THE PACIFIC
AND TRACK E IN A MORE PROGRESSIVE LOWER AMPLITUDE FLOW REGIME...
THOUGH NOTHING LOOKS SIGNIFICANT. NORMALLY WOULD BE DEALING WITH LES
OFF LAKE SUPERIOR IN THIS COLD AIR MASS...BUT WITH EXTENSIVE ICE
COVER THAT SHOULD BE AT OR VERY NEAR 100PCT...LES MAY BE SHUTDOWN
THRU THIS FCST PERIOD.
BEGINNING SAT...FCST AREA WILL BE UNDER RENEWED CAA IN NW FLOW BTWN
DEPARTING LOW PRES TROF AND CANADIAN HIGH PRES BUILDING INTO THE NRN
PLAINS. 850MB TEMPS RANGING FROM AROUND -18C SE TO -24C NW AT 12Z
WILL FALL TO -25C SE TO -29C NW BY EVENING. AS A RESULT...TEMPS WILL
STRUGGLE TO GET ABOVE 0F OVER THE W. TO THE S AND E...TEMPS SHOULD
RISE TOWARD 10F WITH THE SLIGHTLY WARMER AIR IN THAT AREA TO START
THE DAY. MAINTAINED SCHC POPS FOR LES IN AREAS FAVORED BY NW WINDS
OFF LAKE SUPERIOR...BUT IT IS QUITE POSSIBLE THE LAKE WILL BE
COMPLETELY ICE COVERED...PREVENTING ANY LES. HOWEVER...IF NW WINDS
ARE STRONG ENOUGH SAT TO PUSH THE ICE A BIT...THERE MAY BE A LITTLE
OPEN WATER ALONG THE IMMEDIATE MN N SHORE UP PAST ISLE ROYALE AND
ALSO TO THE LEE OF THE KEWEENAW PENINSULA. IF SO...THERE WILL BE A
FEW -SHSN AND THUS THE SCHC POPS. OTHERWISE...WINDS MAY BE GUSTY
ENOUGH TO PRODUCE SOME BLSN/REDUCED VIS IN OPEN AREAS NEAR LAKE
SUPERIOR...BUT SHOULDN`T BE TOO BIG OF AN ISSUE GIVEN THE LACK OF
SNOW FALLING. WINDS IN THE MORNING MAY ALSO BE STRONG ENOUGH TO
DRIVE WIND CHILLS DOWN TO THE ADVY CATEGORY OVER THE W. WITH
DISTURBANCE STREAKING E TOWARD THE SRN LAKES...NOT OUT OF THE
QUESTION THAT THE NRN FRINGE OF -SN SHIELD COULD BRUSH THE FAR
SCNTRL LATE IN THE DAY INTO SAT EVENING. RETAINED SCHC POPS THERE.
SFC HIGH PRES RIDGE STRETCHING FROM HIGH CENTER IN THE NRN PLAINS
INTO THE UPPER LAKES WILL ENSURE A PERIOD OF DRY...BUT STILL VERY
COLD WEATHER SAT NIGHT/SUN. TEMPS SAT NIGHT AND FOR THAT MATTER EACH
OF THE FOLLOWING NIGHTS THRU EARLY NEXT WEEK WILL BE A CHALLENGE.
DEPENDING ON CLOUD COVER AND WINDS...MIN TEMPS COULD BE VERY LOW
EACH NIGHT (WELL BLO LOWEST GUIDANCE) UNDER LINGERING BUT GRADUALLY
MODERATING ARCTIC AIR MASS. HIGH CLOUDS ON THE NRN FRINGE OF
DISTURBANCE PASSING TO THE S OF THE AREA MAY LIMIT COOLING SOME SAT
NIGHT. OTHERWISE...CLOUD COVER MAY NOT BE THAT MUCH OF AN ISSUE THRU
EARLY NEXT WEEK AS THERE SHOULD BE LITTLE IF ANY STRATOCU OFF WHAT
SHOULD BE A TOTALLY ICE COVERED LAKE SUPERIOR. WITH WINDS MOSTLY
LIGHT EACH NIGHT WITH WEAK PRES GRADIENT ASSOCIATED WITH HIGH PRES
IN THE AREA...WILL CONTINUE TO FAVOR MIN TEMPS GENERALLY AT OR BLO
THE LOWEST GUIDANCE SAT NIGHT AND SUN NIGHT...ESPECIALLY FOR
TRADITIONAL COLD SPOTS. SINCE INCREASING CLOUDS FROM THE W WILL BE A
FACTOR MON NIGHT...WILL FAVOR THE LOWEST READINGS OVER THE E THAT
NIGHT. INCREASINGLY HIGHER SUN ANGLE AT THIS TIME OF YEAR WORKING ON
LOWER ALBEDO FORESTED TERRAIN WILL HELP TEMPS RISE NICELY FROM
FRIGID OVERNIGHT LOWS EACH DAY...THOUGH MAX TEMPS WILL STILL BE WELL
BLO NORMAL. HIGHS IN THE SINGLE DIGITS TO AROUND 10F SUN WILL
GENERALLY RISE A COUPLE OF DEGREES FOR MON.
AS PREVIOUSLY MENTIONED...IT LOOKS LIKE THERE WILL BE A SERIES OF
SHORTWAVES TRACKING ACROSS THE CONUS MID AND LATE NEXT WEEK.
INCREASING CLOUDS MON NIGHT WILL BE AHEAD OF THE FIRST WAVE. THERE
IS DISAGREEMENT ON WHETHER THAT WAVE WILL TRACK FAR ENOUGH N TO
BRING SOME -SN TO THE AREA TUE. THE GEM KEEPS SYSTEM FARTHER S...SO
NO -SN...THE ECMWF/GFS ARE FARTHER N. FOLLOWING THAT SYSTEM...THERE
WILL BE MORE SHORTWAVES...BUT GUIDANCE HAS NOT BEEN CONSISTENT ON
TIMING/STRENGTH OF WAVES. FCST WILL SHOW SCHC POPS THRU MUCH OF THE
TUE-THU TIME PERIOD UNTIL SOME AGREEMENT/CONSISTENCY DEVELOPS IN
MODEL GUIDANCE. TEMPS WILL CONTINUE TO MODERATE THRU THE WEEK.
BY WED...HIGH TEMPS WILL BE NEARING 20F...AND ON THU...TEMPS MAY
PUSH WELL INTO THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1231 PM EST FRI FEB 28 2014
EXPECT VFR CONDITIONS EARLY IN THE FCST PERIOD TO GIVE WAY TO MVFR
CONDITIONS BY MID/LATE AFTN AS AREA OF -SN ASSOCIATED WITH LO PRES
MOVING THRU NW MN OVERSPREADS UPR MI. BEST CHC FOR SOMEWHAT HEAVIER
SN/IFR VSBYS WL BE AT SAW TOWARD 00Z...CLOSER TO WHEN BETTER DYNAMIC
SUPPORT IS FCST TO IMPACT SCENTRAL UPR MI. THE ARRIVAL OF DRIER AIR
ALF WL END THE PCPN W-E THIS EVNG...BUT EXPECT PREDOMINANT MVFR CIGS
TO LINGER THRU SAT MRNG AT IWD/CMX WITH STEADY...UPSLOPE NW FLOW OF
COLDER AIR. EXTENSIVE ICE COVER OVER LK SUP WL LIMIT THE POTENTIAL
FOR HEAVIER LES THAT WOULD NORMALLY BE A PROBLEM AT THESE LOCATIONS.
DOWNSLOPE NATURE OF THE NW FLOW SHOULD RESULT IN A TREND TOWARD VFR
CONDITIONS AT SAW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST FRI FEB 28 2014
MUCH LIGHTER WINDS AND PLENTY OF VERY COLD AIR WILL LIKELY ACT TO
QUICKLY FORM ANOTHER ROUND OF THIN ICE ACROSS MUCH OF THE LINGERING
OPEN WATERS OF LAKE SUPERIOR /AS SEEN ON THE LAST FEW VIS SATELLITE
IMAGES YESTERDAY AFTERNOON/. THE COLDEST TEMPERATURES WILL BE THIS
MORNING/TODAY. THE ARCTIC HIGH OVER MUCH OF THE GREAT LAKES REGION
WILL CONTINUE TO MOVE E TO THE NEW ENGLAND STATES BY THIS EVENING. A
LOW/TROUGH WILL BRIEFLY CROSS LAKE SUPERIOR LATE THIS AFTERNOON AND
TONIGHT...BEFORE A RIDGE BUILDS BACK ACROSS THE GREAT LAKES FROM THE
N PLAINS AND S CENTRAL CANADA SATURDAY THROUGH MONDAY. A LOW/TROUGH
EXTENDING FROM A SYSTEM ORGANIZING OVER THE PLAINS WILL APPROACH
LAKE SUPERIOR LATE TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST SATURDAY FOR MIZ013-014.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...ROLFSON
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1135 AM CST FRI FEB 28 2014
.UPDATE...
ISSUED AT 1135 AM CST FRI FEB 28 2014
A WEAK SHORTWAVE TROF IS MOVING THRU AND GENERATING THESE MID-
LEVEL RETURNS YOU`RE SEEING ON RADAR. MESONET STATIONS SHOW THAT
THERE ARE STILL SOME POCKETS NE OF THE TRI-CITIES THAT ARE AT OR
BELOW 32F. SO FRZG SPRINKLES ARE STILL POSSIBLE. OTHERWISE...IT`S
SPRINKLES AND THEY COULD MIX WITH SLEET BASED ON FCST SOUNDINGS.
UPDATE ISSUED AT 944 AM CST FRI FEB 28 2014
HAD TO BACKTRACK ON THE CLOUD COVER CHANGES NOW THAT THE FIRST
VISIBLE SAT IMAGES ARE AVAILABLE. A SHIELD OF 1200-2800 FT
OVERCAST IS ADVANCING SE THRU THE SANDHILLS BEHIND THE COLD FRONT.
SO ANY LITTLE SUN THIS MORNING OVER S-CNTRL NEB WILL SOON END.
S OF THE SNOWPACK OVER N-CNTRL KS...IT`S SHAPING UP TO BE A VERY
NICE DAY AND WE COULD BE A LITTLE LOW ON HIGH TEMPS BASED ON
MORNING SOUNDINGS. HOWEVER...THE FRONTAL PASSAGE RESTRAINS
CONFIDENCE IN INCREASING TEMPS JUST YET.
HAVE ALSO MADE SOME MAJOR ADJUSTMENTS TO DEWPOINTS THRU SUNSET. WE
WERE NOT LOW ENOUGH NE OF THE TRI-CITIES. HAVE ADJUSTED THE FCST
USING THE CONSENSUS OF SHORT-TERM GUIDANCE.
UPDATE ISSUED AT 845 AM CST FRI FEB 28 2014
NO SUBSTANTIVE CHANGES NEEDED FOR THIS ESTF UPDATE. BASED ON
SATELLITE...CLOUDS WERE BACKED DOWN THIS AFTERNOON AND POSSIBLY
NOT AS MUCH AS NECESSARY. BUT BELIEVE WE HAVE TRENDED THE FCST IN
THE RIGHT DIRECTION.
THE FRONT IS PROGRESSING THRU THE SANDHILLS AND PANHANDLE. I LIKE
THE WINDS WE HAVE IN THE FCST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI FEB 28 2014
THE FOCUS DURING THE SHORT TERM PERIODS IS ON THE TIMING OF A
COLD FRONTAL BOUNDARY TODAY AND ANY ASSOCIATED LIGHT PRECIPITATION.
THE PATTERN ALOFT FEATURED NORTHWEST FLOW ACROSS OUR
REGION...WHILE TO THE SOUTH A SHORTWAVE TROUGH WAS TRANSLATING
EASTWARD ACROSS OK/SOUTHERN KANSAS. AT THE SURFACE...SOUTHERLY
FLOW WAS IN PLACE WITH LOW PRESSURE ORIENTED ALONG THE HIGH PLAINS
WITH LOW PRESSURE CENTERS LOCATED IN SOUTHWEST SD AND SOUTHEAST
CO. THE COLD FRONTAL BOUNDARY WHICH WILL CROSS THE PLAINS TODAY
WAS LOCATED IN SOUTHEAST MT/NORTHERN WY EARLY THIS MORNING.
PCPN ASSOCIATED WITH SYSTEM CROSSING KS/OK SHOULD REMAIN SOUTH OF
AREA BUT DID INCLUDE SOME SILENT POPS IN KS IN CASE IT MIGRATES A
LITTLE FARTHER NORTH. OTHERWISE MODELS HAVE TRENDED SLOWER WITH
THE PASSAGE OF THE COLD FRONTAL BOUNDARY TODAY. THE FRONT SHOULD
REACH OUR NW CWA BY MID DAY AND MOVE THRU THE REMAINDER OF OUR CWA
DURING THE AFTERNOON. WITH THE SLOWER TIMING OF THE FRONT...TEMPS
LOOK TO WARM AHEAD OF THE SYSTEM AND RAISED HIGHS BY SEVERAL
DEGREES FOR MAX TEMPS WITH READINGS WARMER THAN GUIDANCE BUT NOT
AS WARM AS THE RAP SUGGESTS. TEMPS WILL NEED TO BE MONITORED
CLOSER TODAY...THEN AS THE FRONT MOVES THROUGH STEADYING/FALLING
TEMPS ARE EXPECTED ACROSS OUR NORTHERN ZONES.
MID LEVEL FRONTOGENETIC FORCING COMBINED WITH UPPER JET DYNAMICS WILL
BRING THE CHC FOR LIGHT PCPN DEVELOPMENT ACROSS OUR NORTHERN/EASTERN
ZONES DURING THE AFTN/EVE. PCPN TYPE OF R/S WILL BE DEPENDENT ON
HOW WARM TEMPS RISE BEFORE COOLING/FALLING WITH CAA BEHIND THE
BOUNDARY. MODELS ALSO DIFFER ON WHETHER PCPN WILL BE MORE THAN A
TRACE EVENT OF FLURRIES/SPRINKLES OR WHETHER LIGHT ACCUMULATIONS ARE
POSSIBLE. HAVE CARRIED LOW POPS WITH OUR CWA ON THE BUFFER OF
BETTER CHCS FOR ACCUMULATIONS TO OUR NORTH AND EAST. ALSO
TODAY...3 HR PRESSURE RISES BEHIND THE FRONT AVERAGE 4MB AND WINDS
WILL INCREASE FM THE NORTH WITH GUSTS OVER 30 MPH POSSIBLE AND
WINDS WILL REMAIN STEADY FROM THE NORTH INTO THE OVERNIGHT PERIOD.
A SURFACE RIDGE BUILDS SOUTH ACROSS THE PLAINS TONIGHT BEHIND THE FRONT
AND COLD AIR ADVECTION CONTINUES THROUGH THE NIGHT. H85 TEMPS DROP
TO AROUND -18C ACROSS OUR NORTH BY MORNING AND IN THE ARCTIC
AIRMASS OVERNIGHT LOWS WILL AVERAGE IN THE SINGLE DIGITS. CURRENT
WIND CHILL VALUES ARE THE COLDEST ALONG AND NORTH OF INTERSTATE 80
IN NEBRASKA WHERE VALUES DROP TO THE 15 TO 20 DEGREE BELOW ZERO
RANGE AND WILL CONTINUE TO MENTION THIS IN THE HWO. ISENTROPIC
LIFT BEGINS TO INCREASE ACROSS OUR NW ZONES TOWARDS SATURDAY
MORNING AHEAD OF THE NEXT APPROACHING SYSTEM AND INCLUDED LOW POPS
TOWARD DAYBREAK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI FEB 28 2014
PRIMARY FORECAST CONCERN THROUGH THE LONG TERM PERIOD LIES WITH THE
FIRST 36 HRS OR SO...AS ACCUMULATING SNOWFALL CHANCES TAKE AIM ON
THE PLAINS.
THE GENERAL STORY FOR THE SATURDAY THROUGH SUNDAY TIME FRAME HASNT
CHANGED SIGNIFICANTLY...WITH THE CWA COMING UNDER THE INFLUENCE OF A
FEW UPPER LEVEL DISTURBANCES...A SHORTWAVE TROUGH SWINGING SOUTH OUT
OF CANADA ASSOCIATED WITH THE PARENT HUDSON BAY LOW...AS WELL AS A
STORM SYSTEM WHICH IS CURRENTLY STILL JUST OFF THE WEST COAST. WILL
STATE UPFRONT THAT CONFIDENCE IN THIS PERIOD...EVEN THIS CLOSE TO
THE EVENT...IS ON THE LOW SIDE DUE TO MODEL DIFFERENCES THAT REMAIN.
DURING THE DAYTIME HOURS...EXPECTING PRECIPITATION TO START ROLLING
IN FROM THE NW AS THE BASE OF THAT NRN DISTURBANCE SWINGS MAINLY
THROUGH THE DAKOTAS. A FEW MODELS SHOW THE POTENTIAL FOR SOME
COUPLING OF UPPER LEVEL JET STREAKS IN THE AREA...OTHERS NOT SO
MUCH...BUT ALL AGREE WITH THE STRONGEST JET STREAK BEING WELL NORTH
OF THE CWA...AND ALSO EXPECTING TO SEE INCREASED MID LEVEL
ISENTROPIC LIFT DEVELOPING...WITH THE PAST FEW RUNS OF MODELS HAVING
SHOWN A SLIGHT NORTHWARD SHIFT. LATEST RUNS HAVE DECENT AGREEMENT
SHOWING THE MORE FOCUSED AREA OF PRECIPITATION SLIDING ACROSS MAINLY
THE NRN HALF OF NEB...INCLUDING PORTIONS OF THE CWA ROUGHLY
ALONG/NORTH OF INTERSTATE 80. OUTSIDE OF THE 00Z GFS...OTHER MODELS
SHOWING PRETTY LIGHT QPF AMOUNTS SOUTH OF THERE. LOOKING AT FORECAST
SOUNDINGS IN THE SOUTH...CANT COMPLETELY RULE OUT A BRIEF PERIOD OF
SLEET THANKS TO A WARMER NOSE ALOFT...SO WILL KEEP THAT SLIGHT
CHANCE MENTION GOING. OTHERWISE PTYPE FURTHER NORTH AND THEN
THROUGH THE REST OF THE EVENT LOOKS TO BE SNOW.
INTO THE EVENING/OVERNIGHT HOURS...LATEST MODEL RUNS HAVE NOT HELPED
WITH CONFIDENCE. IF YOU TAKE THE 06Z NAM AS IS...DRIER AIR ASSOCIATED
WITH HIGH PRESSURE BUILDING SOUTH COMPLETELY SHUTS OFF PRECIPITATION
FOR A MAJORITY OF THE CWA. OTHERS ARE NOT QUITE SO DRAMATIC...AND
WHILE BETTER FOCUS HAS SHIFTED SOUTH...THE CWA IS NOT OUT OF THE
CLEAR AS THE LOW PRESSURE SYSTEM CURRENTLY OFF THE WEST
COAST...WHILE IT WEAKENS/FILLS QUITE A BIT ONCE ITS INLAND...IS
MAKING ITS WAY THROUGH THE ROCKIES DURING THIS PERIOD.
DURING THE DAYTIME HOURS ON SUNDAY...THE LOW CONFIDENCE CONTINUES.
THE MAIN FOCUS FOR THIS PERIOD LIES WITH THE ARRIVAL/PASSAGE OF THAT
WRN UPPER LEVEL DISTURBANCE. WHILE SATURDAYS BETTER SNOW CHANCES
LIE ACROSS NRN LOCATIONS...SUNDAYS FOCUS SHIFTS TO THE SRN CWA.
THIS DISTURBANCE MOVES OUT OF THE ROCKIES AND THROUGH THE
PLAINS...WITH MODELS SHOWING THE BRUNT OF THE FORCING ANYWHERE FROM
SRN NEB TO OK.
AS FAR AS SNOWFALL TOTALS GO...DIDNT MAKE SIGNIFICANT CHANGES TO THE
INHERITED FORECAST...AND CURRENTLY HAVE ANYWHERE FROM 2 IN THE WEST
TO ARND 4.5 IN THE FAR SE CORNER. HOWEVER...LIKE MENTIONED
ABOVE...CONFIDENCE IS ON THE LOW SIDE...SO EXPECT THERE TO BE
ADJUSTMENTS AS WE GET CLOSER. REMEMBER THAT WRN SYSTEM ISNT EVEN ON
SHORE YET...AND ITS THAT SYSTEM MODELS HAVE SOME BIGGER
DIFFERENCES. WILL HAVE TO KEEP AN EYE ON UPCOMING RUNS TO SEE IF
THEY TREND TOWARD SOMETHING LIKE THAT 06Z NAM...SUGGESTING AFTER
ROUGHLY LATE SATURDAY EVENING...WE COULD BE DONE WITH PRECIP...AS IT
KEEPS THE REMAINDER OF THE EVENT ACROSS KS/OK. CURRENT FORECAST
TOTALS ARE NOT TRENDED THAT WAY...BUT ITS SOMETHING TO KEEP AN EYE
ON. IN REGARD TO ANY KIND OF WINTER HEADLINE...WILL LET DAY CREW GET
A FRESH SET OF MODELS AND TRY TO PIN MORE DETAILS DOWN. CERTAINLY
POSSIBLE ONE WILL BE NEEDED BETWEEN THE COMBO OF SNOW AND WIND
CHILLS...JUST TO MANY UNCERTAINTIES AT THIS POINT TO GO WITH ONE.
ITS BEEN WELL ADVERTISED THAT MUCH COLDER AIR WOULD BE ACCOMPANYING
THESE SNOW CHANCES THIS WEEKEND...AND THAT UNFORTUNATELY HASNT
CHANGED. STILL LOOKING AT A BITTERLY COLD WEEKEND...AFTER SINGLE
DIGITS TO MID TEENS FOR HIGHS ON SATURDAY...SUNDAY IS COLDER...WITH
FORECAST HIGHS NOT GETTING OUT OF THE SINGLE DIGITS ACROSS THE
ENTIRE CWA. COMBINED WITH AT TIMES BREEZY N/NE WINDS...WIND CHILL
VALUES DROPPING NEAR/BELOW -20 STILL IN THE FORECAST.
LOOKING AHEAD TO THE UPCOMING WORK WEEK...MONDAY THROUGH
THURSDAY...KEPT THE FORECAST DRY...AND ARE EXPECTING TO SEE
MODERATING TEMPERATURES. BEHIND THE DISTURBANCE MOVING THROUGH ON
SUNDAY...NORTHWESTERLY FLOW SETS UP IN THE UPPER LEVELS...GENERALLY
REMAINING THAT WAY THROUGH THE REST OF THE LONG TERM PERIOD. WILL
HAVE TO WATCH THE POTENTIAL FOR A COUPLE OF DISTURBANCES MOVING
THROUGH LOCATIONS MAINLY NORTH OF HERE...BUT AT THIS POINT UNTIL
THINGS ARE IN BETTER AGREEMENT THE FORECAST IS DRY. THIS LATEST
BATCH OF BITTERLY COLD AIR ALOFT GETS PUSHED OFF TO THE EAST...WITH
850MB TEMPS GOING FROM ROUGHLY -10 TO -20 SUNDAY MORNING TO POSSIBLY
5 T0 10 ABOVE ZERO FOR THE TUES THROUGH THURS PERIOD. FORECAST
HIGHS RANGE FROM THE TEENS FOR MONDAY TO 40S/50S FOR THURSDAY.
&&
.AVIATION...(FOR THE 18Z GRI TAF THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1135 AM CST FRI FEB 28 2014
THIS AFTERNOON: VFR WILL DECAY TO MVFR. THE COLD FRONT WILL BE
THRU GRI BY 19Z AND EXPECT WINDS TO SHIFT N AND GUST TO 25 KTS. A
DECK OF MVFR STRATUS WILL INVADE AS WELL. RADAR SHOWS SOME MID-
LEVEL GENERATED PRECIP AND GIVEN THE WARM NOSE IN THE TEMP PROFILE
3500-6000 FT...SOME IP COULD MIX IN. IT SHOULD BE DONE BY 22Z AT
THE LATEST. CONFIDENCE: MEDIUM
TONIGHT: LOW-LEVEL RH AND SREF CEILING GUIDANCE SUGGEST THE MVFR
CLOUDS SHOULD SCATTER 01Z-04Z...LEAVING VFR MID-LEVEL CIGS AROUND
12K FT. DAYTIME GUSTINESS SHOULD END BY 02Z. N WINDS CONTINUE
15-20 KTS. CONFIDENCE: MEDIUM
SAT: VFR TO START BUT CIGS STEADILY LOWER 12Z-15Z WITH SNOW MOVING
IN 15Z-18Z. GRI LIKELY TO BECOME IFR/LIFR TOWARD 15Z. NNE WINDS
AROUND 20 KTS. CONFIDENCE: MEDIUM
&&
.CLIMATE...
ISSUED AT 726 AM CST FRI FEB 28 2014
AVERAGE FEB TEMP AT GRAND ISLAND: AS OF MIDNIGHT IT SITS AT 23.4F
AND GIVEN THE LOW OF 15F THIS MORNING...AND THE PROJECTED HIGH
TODAY...IT LOOKS LIKE GRI WILL FINISH THE MONTH WITH AN AVG TEMP
OF 23.5F /5.5 COLDER THAN NORMAL/. THAT WILL MAKE THIS THE
COLDEST FEB SINCE 2001 WHEN THE AVG TEMP WAS 20.6F.
FOLLOWING BELOW IS A RECAP OF THE DAILY RECORD COLD MAXIMUM
TEMPERATURES FOR GRAND ISLAND AND HASTINGS THAT COULD BE IN
JEOPARDY THIS WEEKEND. IN ADDITION TO POSSIBLE DAILY RECORDS...ITS
NOT OUT OF THE REALM OF POSSIBILITY THAT SUNDAY COULD COME VERY
CLOSE TO THE COLDEST MAXIMUM (HIGH) TEMPERATURE ON RECORD FOR ANY
DAY IN MARCH:
THE DAILY RECORDS FOR COLDEST MAX TEMP STAND AS FOLLOWS:
- MARCH 1: GRAND ISLAND...10 IN 1922
HASTINGS...15 IN 1980, 1916, 1913
- MARCH 2: GRAND ISLAND...10 IN 2002
HASTINGS...11 IN 2002
- MARCH 3: GRAND ISLAND...8 IN 1916
HASTINGS...10 IN 2002
THE COLDEST MAX TEMP ON RECORD FOR ANY DAY IN MARCH:
- GRAND ISLAND: 4 DEGREES ON 3-10-1948
- HASTINGS: 3 DEGREES ON 3-11-1948
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...FAY
LONG TERM...ADO
AVIATION...HALBLAUB
CLIMATE...PFANNKUCH/HALBLAUB
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
348 PM CST FRI FEB 28 2014
.SHORT TERM...
FOLLOWING A COMPACT S/W TROUGH THAT GENERATED TSTORMS IN PARTS OF
THE TX PANHANDLE LAST NIGHT...THE AXIS OF STRONG WESTERLY WINDS HAVE
SINCE EXITED THE FORECAST AREA ON SCHEDULE. THESE WINDS DID RESULT
IN A BIT MORE DRAMA THAN EXPECTED THANKS TO A 59 MPH GUST AS
MEASURED BY THE GRAHAM WEST TX MESONET...BUT AS A WHOLE THE BLOWING
DUST THIS MORNING WAS NOTHING UNUSUAL FOR THE HARDY RESIDENTS THAT
FREQUENT THESE PARTS.
ALREADY BY SUNSET...A WEAK COLD FRONT WILL BE EDGING SOUTHWEST
ACROSS THE EASTERN PANHANDLE WELL AHEAD OF A BROODING ARCTIC HIGH
STILL POISED IN THE WESTERN CANADIAN PRAIRIES. DO BELIEVE THE
NON-RUC GUIDANCE IS TOO CONSERVATIVE WITH THIS FRONT/S PROGRESS
TONIGHT...SO HAVE EDGED LOW TEMPS DOWN A BIT ESPECIALLY NORTHEAST
OF THE HIGHWAY 84 CORRIDOR WHERE THE RUC HAS THIS BOUNDARY ROUGHLY
STALLING BY DAYBREAK. THIS BOUNDARY HOWEVER WILL RETREAT BY LATE
MORNING AS WINDS ALOFT BACK SWLY AND AMPLIFY MODESTLY AHEAD OF
SUNDAY/S UPPER TROUGH. AS WE SAW TODAY...EARLIER MODELS WERE MUCH
TOO MOIST WITH 2M DEWPOINTS...BUT THIS WAS EXPECTED IN PRIOR
FORECASTS AND WE CONTINUE TO EMPLOY THIS RATIONALE WITH TOMORROW/S
SETUP BEHIND THE RETREATING FRONT. NUDGED HIGHS UP A FEW DEGREES ON
THE CAPROCK WHERE THE DRIEST AIR WILL BE FOUND AND THIS WILL ALSO
RESULT IN SOME FIRE WX CONCERNS...ALTHOUGH NOT TO THE DEGREE THAT WE
SAW TODAY.
&&
.LONG TERM...
BROAD SOUTHWESTERLY FLOW WILL BE IN PLACE BY LATE SATURDAY. WHAT IS
CURRENTLY A WOUND-UP SPIRAL OFF THE COAST WILL BECOME AN OPEN TROUGH
FROM THE GREAT BASIC TO BAJA. NORTH OF THE BORDER...A COMPLEX
ELONGATED LOW SPANNING MUCH OF CANADA IS LATITUDINALLY ORIENTED
AROUND 55N. MODEL GUIDANCE IS FAIRLY CONSISTENT WITH THE SYNOPTIC
SCALE FEATURES OVER THE NEXT 7 DAYS. THE WEST COAST TROUGH IS
EXPECTED TO APPROACH ON SUNDAY FOLLOWED BY A MORE SUBTLE EMBEDDED
TROUGH INTO MONDAY. ON WEDNESDAY...YET ANOTHER TROUGH AXIS
APPROACHES AND STARTS TO DEEPEN BEFORE DIVING INTO THE GULF COAST
SATES LATE WEEK. OUR FINAL TROUGH OF THE EXTENDED APPROACHES ON
FRIDAY.
YET ANOTHER BACK DOOR COLD FRONT SNEAKS INTO THE AREA ON SUNDAY
MAKING FCST HIGHS QUITE TRICKY AS THE BOUNDARY HANGS UP FOR SEVERAL
HOURS ACROSS THE CWFA. THEN...WITH THE FALL OF NIGHT...THE COLDER
AIR SHOULD FILTER INTO THE REGION. OVERNIGHT BUT NOT BEFORE THERE
IS SOME OPPORTUNITY FOR PRECIPITATION.
MONDAY SHOULD REMAIN DRY AND QUITE COOL BEFORE RETURN FLOW SETS UP
ON TUESDAY QUICKLY REBOUNDING TEMPERATURES THOUGH PERHAPS REMAINING
A FEW DEGREES SHY OF CLIMATOLOGICAL AVERAGES. ANOTHER COLD FRONT
ENTERS THE REGION WEDNESDAY MORNING HELPING TO HOLD TEMPS DOWN ONE
MORE DAY BEFORE SOUTHWESTERLY SURFACE FLOW PICKS UP FOR THURSDAY
WITH THE POTENTIAL FOR ANOTHER BOUT OF FIRE WEATHER LATE NEXT WEEK.
YET ANOTHER PUSH OF COLD AIR ENTERS FOR SEVERE WEATHER AWARENESS DAY.
&&
.FIRE WEATHER...
WIDESPREAD RED FLAG CONDITIONS CONTINUE THIS AFTERNOON ACROSS THE
SOUTH PLAINS AND MUCH OF THE ROLLING PLAINS. THE STRONGEST WINDS
HAVE SINCE DEPARTED THE REGION...BUT 20-FOOT SPEEDS OF 20-25 MPH
WILL CONTINUE UNTIL 6 PM AT WHICH POINT THE RED FLAG WARNING SHOULD
BE ALLOWED TO EXPIRE.
BY THIS EVENING AND OVERNIGHT...A LIGHT NORTHEAST WIND SHIFT WILL
PUSH SOUTHWEST ACROSS THE ROLLING PLAINS AND EASTERN SOUTH PLAINS
BEFORE RETREATING NORTHEAST BY LATE SATURDAY MORNING. ELEVATED TO
MARGINALLY CRITICAL FIRE WEATHER IS POSSIBLE BY SATURDAY AFTERNOON
ON THE CAPROCK AS SOUTHWEST WINDS RISE TO 15 TO 25 MPH WITH MIN RH
VALUES FALLING INTO THE LOWER-TO-MID TEENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 36 75 32 34 12 / 0 0 20 30 10
TULIA 37 75 25 29 10 / 0 0 20 20 10
PLAINVIEW 39 77 27 32 11 / 0 0 10 20 10
LEVELLAND 39 80 33 45 15 / 0 0 10 20 10
LUBBOCK 38 80 29 40 14 / 0 0 10 20 10
DENVER CITY 44 79 36 54 20 / 0 0 10 20 10
BROWNFIELD 42 80 34 46 18 / 0 0 10 20 10
CHILDRESS 37 68 24 25 10 / 0 0 10 20 10
SPUR 39 80 25 34 13 / 0 0 10 20 10
ASPERMONT 39 83 25 31 12 / 0 0 20 20 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: TXZ021>023-027>031-033>044.
&&
$$
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