Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/01/15
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
911 AM PST FRI FEB 27 2015
.UPDATE...
MAIN FOCUS FOR THE UPDATE IS TO ISSUE A WINTER WEATHER ADVISORY
FOR THE SIERRA FRONT TONIGHT INTO SATURDAY. AS FOR THE REST OF
TODAY, DID MAKE SOME MINOR CHANGES TO ADD THE THREAT OF
THUNDERSTORMS NORTH OF I-80 THIS AFTERNOON AND REDUCE SOME CLOUD
COVER TO MAKE IT MORE MOSTLY CLOUDY AS THERE WILL BE BREAKS OF
SUN. REGARDING THE CONVECTION, MODERATE SHOWERS ARE ALREADY
POPPING NORTH OF HIGHWAY 50 AND THESE SHOULD INTENSIFY WITH
HEATING. MODELS ALL SHOWING ENOUGH INSTABILITY FOR SOME ISOLATED
THUNDERSTORMS AS WELL.
TONIGHT INTO SATURDAY MORNING, THE GFS AND EC CONTINUE TO SHOW A
BAND OF MODERATE SNOW TO AFFECT PORTIONS OF THE TAHOE BASIN AND
SIERRA FRONT. HIGH CONFIDENCE NOW IN THIS BAND DEVELOPING AS THE
LATEST HRRR IS SHOWING IT AT THE END OF ITS RUN. LATEST RUNS HAVE
ALSO SHIFTED IT SOUTH AGAIN OVER DOUGLAS COUNTY AND SOUTH LAKE.
ADVISORY ALREADY ISSUED FOR TAHOE AND WILL ADD THE SIERRA FRONT TO
RUN FROM 8 PM TONIGHT UNTIL 10 AM TOMORROW MORNING. OUTSIDE OF
THIS BAND LIGHTER AMOUNTS NEAR 2 INCHES FOR THE SIERRA FRONT AND
UP TO 4 INCHES FOR THE TAHOE BASIN ARE LIKELY. HOWEVER, IN THIS
BAND EXPECT HEAVIER AMOUNTS AS MODEL QPF IS NEAR 1/2 TO 3/4 INCH
IN PLACES. WITH A GOOD DENTRITIC SNOW GROWTH LAYER PRESENT, IT
COULD ADD UP. WILL GO WITH 3-6 INCHES IN THIS BAND FOR THE SIERRA
FRONT AND 4-8 FOR THE TAHOE BASIN WITH 12+ INCHES POSSIBLE ABOVE
7K.
WILL MENTION THE MOST LIKELY PLACES (OR OUR BEST GUESS) FOR
THE HEAVIER BAND. HOWEVER, THE EXACT LOCATION REMAINS LOW
CONFIDENCE. IT IS STILL POSSIBLE IT COULD BE CENTERED OVER CARSON
CITY OR EVEN TRUCKEE/RENO (LOWEST PROBABILITY FOR THE LATTER).
HOPE TO HAVE ALL UPDATES OUT BY 10 AM. WALLMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 324 AM PST FRI FEB 27 2015/
SYNOPSIS...
WINTER SYSTEM IS ON TRACK TO IMPACT THE SIERRA AND NORTHWEST
NEVADA TODAY AND SATURDAY. ACCUMULATING SNOW AND DIFFICULT TRAVEL
CONDITIONS ARE LIKELY IN THE SIERRA WITH LIGHTER ACCUMULATIONS
POSSIBLE IN WESTERN NEVADA. THIS SYSTEM WILL SLOWLY EXIT SUNDAY
WITH ANOTHER CHANCE AT PRECIPITATION POSSIBLE LATE MONDAY INTO
TUESDAY.
SHORT TERM...
THE UPPER LEVEL LOW RESPONSIBLE FOR THE THE WINTER WEATHER THIS
WEEKEND IS CURRENTLY DROPPING SOUTH ALONG THE PACIFIC NORTHWEST
COAST. AHEAD OF THIS FEATURE, WEAK WARM AIR ADVECTION IS GENERATING
LIGHT PRECIPITATION EARLY THIS MORNING.
THE LOW WILL CONTINUE SOUTH TODAY, PUSHING A DIFFUSE COLD FRONT
THROUGH THE EASTERN SIERRA AND WESTERN NEVADA AND BRINGING GUSTY
WEST TO NORTHWEST WINDS TO THE REGION THIS AFTERNOON. THE FRONT
WILL RAPIDLY DROP SNOW LEVELS TO AROUND 4000-5000 FEET FRIDAY
NIGHT, POSSIBLY REACHING AS LOW AS 3500 FEET BY SATURDAY MORNING.
MOST OF THE MOISTURE IS ALONG AND BEHIND THE FRONT WITH SHOWERS
EXPECTED TO INCREASE IN COVERAGE THIS AFTERNOON AND EVENING.
SHOWER ACTIVITY IS RATHER DISORGANIZED, OUTSIDE OF A DEFORMATION
BAND EXPECTED TO FORM LATE TONIGHT INTO SATURDAY. THESE BANDS ARE
NOTORIOUSLY HARD TO PINPOINT LOCATIONS, BUT MODEL TRENDS OVER THE
PAST COUPLE DAYS ARE SHOWING THIS BAND DEVELOPING BETWEEN THE I-80
AND HIGHWAY 50 CORRIDOR. CONFIDENCE IS HIGH THAT THERE WILL BE
SNOW SHOWERS BOTH IN THE SIERRA AND WESTERN NEVADA, BUT MUCH
LOWER IN THE TOTALS. THE SHOWERY NATURE OF THIS SYSTEM MEANS THAT
SNOW TOTALS WILL BE HIGHLY VARIABLE.
THE GREATEST CONFIDENCE IN ACCUMULATING SNOWS IS THROUGH THE TAHOE
BASIN WHERE A WINTER WEATHER ADVISORY IS IN EFFECT LATE FRIDAY
AFTERNOON THROUGH SATURDAY AFTERNOON. 6 TO 12 INCHES OF SNOW IS
POSSIBLE ALONG THE CREST, WITH 3 TO 7 INCHES AT LAKE LEVEL. THOSE
LOCATIONS UNDER ANY ORGANIZED BANDS WILL BE ON THE HIGHER END OF
THE TOTALS, WHILE LOCATIONS WITH JUST GENERAL SHOWERS WILL BE ON
THE LOWER END. FOR WESTERN NEVADA AND THE SIERRA FRONT, CONFIDENCE
IS INCREASING IN SOME AREAS SEEING SEVERAL INCHES OF ACCUMULATION,
BUT CONFIDENCE REMAINS LOW IN EXACTLY WHERE...AND SOME AREAS MAY
STILL SEE NOTHING. MONO COUNTY IS LIKELY TO SEE ACCUMULATING SNOWS
SATURDAY AFTERNOON INTO SUNDAY AS THE UPPER LEVEL FLOW TURNS
NORTHEAST, AIDING IN UPSLOPE ENHANCEMENT. CURRENT FORECAST WOULD
YIELD 6 TO 10 INCHES OF SNOW IN THE HIGH SIERRA WITH 2 TO 4 INCHES
IN THE REST OF MONO COUNTY. THE BIGGEST THING TO TAKE AWAY IS THAT
TRAVEL WILL LIKELY BE IMPACTED FRIDAY AFTERNOON THROUGH SUNDAY
THROUGH PORTIONS OF THE SIERRA AND WESTERN NEVADA. BE PREPARED FOR
WINTER DRIVING CONDITIONS AND CHECK BOTH WEATHER AND ROAD CONDITIONS
BEFORE TRAVEL.
THERE IS PLENTY OF INSTABILITY WITHIN THE CORE OF THE LOW AND THERE
IS A SLIGHT CHANCE OF THUNDERSTORMS NORTH OF I-80 LATE THIS AFTERNOON
AND THEN FROM I-80 SOUTH SATURDAY. PELLET SHOWERS AND/OR A WINTRY
MIX IS POSSIBLE THROUGH THE DAY SATURDAY IN THE COLD CORE. THE LOW
IS SLOWER TO EXIT THE AREA THAN PREVIOUSLY PROGGED, WITH SHOWERS
POSSIBLY LINGERING IN MONO COUNTY THROUGH SUNDAY AFTERNOON IN THE
MOIST AND UNSTABLE NORTHEAST FLOW. TEMPERATURES WILL BE BELOW
NORMAL THROUGH THE PERIOD WITH THE BREEZY WINDS MAKING IT FEEL
EVEN COLDER. DJ
LONG TERM...MONDAY THROUGH THURSDAY...
NO MAJOR CHANGES TO THE LONG TERM FORECAST, WITH THE MAIN WEATHER
CONSIDERATION MONDAY INTO TUESDAY ANY ADDITIONAL SLIDER ENERGY (AND
ASSOCIATED SNOW SHOWERS) THAT MIGHT MOVE OVER EASTERN CALIFORNIA AND
WESTERN NEVADA BEHIND THIS WEEKEND`S SYSTEM.
MONDAY AND MONDAY NIGHT, THE ECMWF, GFS AND GEM ENSEMBLES STILL SHOW
VARYING SOLUTIONS REGARDING A SLIDER-TYPE DISTURBANCE TO MOVE
OVER/NEAR THE REGION. IN FACT, IN THE LAST FEW OPERATIONAL RUNS THE
GFS AND ECMWF HAVE GONE THE OPPOSITE WAY WITH THE GFS LEANING
FARTHER EAST AND MORE PROGRESSIVE WITH THE ECMWF GETTING SLOWER AND
FARTHER WEST (OVER NORTHERN CALIFORNIA) WITH THE SLIDER. MEANWHILE,
THE GEM SEEMS TO BE IN BETWEEN WITH MANY ENSEMBLE RUNS SHOWING THE
DISTURBANCE OVER WESTERN NEVADA OR FAR EASTERN CALIFORNIA.
THE POSITION OF THE SLIDER IS KEY FOR THE COVERAGE/INTENSITY OF SNOW
SHOWERS FOR THE SIERRA AND WESTERN NEVADA, WITH A TRACK NEAR OR WEST
OF THE CREST (BUT STILL EAST OF I-5) IDEAL FOR AN ORGANIZED BAND OF
SNOW. WITH LARGE UNCERTAINTY AS TO THE EXACT TRACK OF THE DISTURBANCE
MONDAY-TUESDAY, I HAVE KEPT THE RUNNING SLIGHT CHANCE TO CHANCE OF
SHOWERS IN PLACE. IN ANY CASE, WELL BELOW AVERAGE TEMPERATURES ARE ON
TAP FOR MONDAY AND TUESDAY WITH NORTHERLY FLOW KEEPING COLDER AIR
INTACT.
WEDNESDAY AND THURSDAY STILL LOOK DRY AS ENSEMBLES ARE IN GOOD
AGREEMENT WITH BUILDING A RIDGE OVERHEAD. TEMPERATURES WILL BEGIN TO
REBOUND TOWARDS NORMAL FOR THE SECOND HALF OF THE WEEK. SNYDER
AVIATION...
FOR THIS MORNING IN NORTHEAST CALIFORNIA AND WESTERN NEVADA,
SCATTERED SHOWERS WILL BRING OCCASIONAL MVFR CIGS TO THE NORTHERN
SIERRA WITH OCCASIONAL HIGHER TERRAIN OBSCUREMENT TO WESTERN NEVADA
NORTH OF HIGHWAY 50. NORTH OF KSVE-GERLACH, CIGS LOOK WORSE WITH
WIDESPREAD MVFR CIGS WITH -SHSN ABV 5-5.5 KFT MSL (AND -SHRASN BLO).
THIS AFTERNOON AND TONIGHT, CIGS/VIS WORSEN AS LOW PRESSURE DROPS
INTO NORTHERN CALIFORNIA AND NEVADA AND WIDESPREAD SNOW AND
RAIN/SNOW BELOW 5,000 FT MSL DEVELOPS. WIDESPREAD IFR CIGS AND ICING
ARE EXPECTED IN THE SIERRA, WITH MVFR (LOCALLY IFR) CIGS INTO
WESTERN NEVADA NORTH OF HIGHWAY 50. ACCUMULATING SNOW IS LIKELY FOR
KTRK/KTVL WITH EVEN SOME ACCUMULATIONS POSSIBLE AT KRNO/KCXP (60%
CHANCE) BETWEEN LATE FRIDAY EVENING AND SATURDAY MORNING.
FOR KMMH, THE WORSE CONDITIONS ARE LIKELY TO BE ON SATURDAY. SNYDER
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM PST
SATURDAY NVZ002.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 10 AM PST
SATURDAY NVZ003.
CA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM PST
SATURDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1242 PM EST FRI FEB 27 2015
.SYNOPSIS...
WEAK IMPULSE MOVES THROUGH THE AREA TODAY FOLLOWED BY AN EXTENSIVE
HIGH PRESSURE SYSTEM FOR A MAJORITY OF THE WEEKEND. AS THE HIGH
SLIPS OFF THE COAST ON SUNDAY A WEAK WARM FRONT LIFTS THROUGH THE
REGION AS LOW PRESSURE PASSES TO OUR WEST AND ITS ASSOCIATED COLD
FRONT PUSHES THROUGH ON MONDAY. ANOTHER LOW PRESSURE EJECTS OUT OF
THE CENTRAL PLAINS AND CROSSES OUR REGION ON TUESDAY INTO WEDNESDAY.
THE LOWS ASSOCIATED COLD FRONT PUSHES THROUGH LATER ON WEDNESDAY
WITH ANOTHER EXPANSIVE HIGH PRESSURE SYSTEM FILLING IN BEHIND IT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS HAVE CONTINUED TO BREAK UP IN MOST PLACES THIS AFTERNOON.
SO WILL FEATURE A MOSTLY SUNNY AFTERNOON ACROSS THE REGION. THE
LATEST RAP AND HRRR MODEL RUNS DO NOT FORM ANY SNOW FLURRIES
EITHER ACROSS THE REGION. INCREASED TEMPERATURES A DEGREE OR TWO WARMER
WITH THE 12:30 PM UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AT LEAST ONE MODEL IS DEPICTING LOW LEVEL CLOUDS DEVELOPING BY THIS
EVENING. HOWEVER, THIS SEEMS UNLIKELY WITH THE SYNOPTIC PATTERN OF A
SURFACE HIGH SLIDING EAST TOWARD THE REGION AS FLOW ALOFT
TRANSITIONS TO MORE ZONAL FLOW. THEREFORE, EXPECT CLEARING SKIES
THIS EVENING INTO THE OVERNIGHT HOURS. THIS, COMBINED WITH
SUBSIDENCE IN THE LOW LEVELS AND LIGHT WINDS WILL LEAD TO PRIME
RADIATIONAL COOLING CONDITIONS, ESPECIALLY FOR LOCATIONS THAT STILL
HAVE A SNOW PACK. THUS, WENT SLIGHTLY BELOW GUIDANCE FOR LOWS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE IS IN PRETTY DECENT AGREEMENT WITH THE LARGE
SCALE FEATURES THROUGH THE EXTENDED PERIOD. THE MID-LEVELS TAKE ON
MORE OF A ZONAL-ISH FLOW OVER THE WEEKEND WITH THE NEXT EMBEDDED
WAVE EXPECTED BY MONDAY FOLLOWED BY DEEPENING RIDGING THROUGH MID-
WEEK AS THE LONGWAVE TROUGH RELOADS TO OUR WEST AND ADVANCES THROUGH
LATE IN THE PERIOD.
SATURDAY...HIGH PRESSURE WILL BE OVERHEAD ALLOWING FOR LOTS OF
SUBSIDENCE AND MOSTLY CLEAR SKIES. TEMPERATURES WILL BE RATHER COLD
STILL, NEARLY 20 DEGREES UNDER CLIMO FOR THE LAST DAY OF
METEOROLOGICAL WINTER.
SUNDAY - MONDAY...ZONAL-ISH FLOW TURNS A BIT SHARPER AS THE BROAD
TROUGH RELOADS WELL TO OUR WEST. ANOTHER PASSING SHORTWAVE ALOFT
APPROACHES AND PUSHES A COLD FRONT THROUGH THE REGION VERY LATE
SUNDAY INTO MONDAY MORNING. OUT AHEAD OF THE FRONT TEMPERATURES ARE
ABLE TO MODIFY A BIT THANKS TO THE DEPARTING HIGH PRESSURE NOW OFF
THE COAST AND A LIGHT RETURN FLOW SETTING UP. WE CONFINED THE HIGHER
POPS UNTIL LATE SUNDAY NIGHT JUST AHEAD AND WITH THE FRONTAL
PASSAGE. DECENT AMOUNT OF THETA-E ADVECTION OCCURRING AHEAD OF THE
COLD FRONT WITH ENOUGH LIFT FOR A LIGHT SNOW TO START BEFORE A
WINTRY MIX OF RAIN/SNOW/SLEET/FREEZING RAIN OCCURS, MOSTLY ACROSS
THE SOUTHERN HALF OF THE CWA, BY MONDAY MORNING. THERE COULD BE SOME
WAK COLD AIR DAMMING OCCURRING, EVEN AS WINDS TURN MORE EASTERLY,
BUT GIVEN THE ARCTIC HIGH WILL BE OFFSHORE AND NOT EXPECTING A HUGE
RESPONSE IN THE LOW-LEVEL WINDS THE GROUND COULD STILL BE COLD
ENOUGH FOR SOME LIGHT FREEZING RAIN...MORE SO THEN WE ARE
CURRENTLY CARRYING IN THE FORECAST.
THE BEST CHANCES FOR AN ALL SNOW EVENT REMAINS ACROSS OUR
NORTHERN MOST ZONES WHERE THE WARM NOSE GETS CLOSE BUT DOES NOT
HAVE ENOUGH PUSH TO MOVE THROUGH, PRIOR TO THE COLD FRONT USHERING
IN ANOTHER SHOT OF COLDER AIR. WE ARE CURRENTLY CARRYING A FEW
INCHES OF SNOW ACROSS THE POCONOS AT THIS TIME.
TUESDAY - THURSDAY...WITH THE COLD FRONT TO OUR EAST AND A BRIEF
SHOT OF HIGH PRESSURE BEHIND IT, THE NEXT SYSTEM, FORMING DEEP IN
THE SOUTH, BEGINS TO ENTER THE REGION FROM THE SOUTHWEST LATER ON
TUESDAY. A LIGHT ONSHORE FLOW WILL HELP TO ENHANCE THE LOW-LEVEL
MOISTURE FLUX WHEN COMBINED WITH A STRONG LOW-LEVEL SOUTHERLY SURGE
OF WARM/MOIST AIR. THIS EVENT COULD HAVE A COPIOUS AMOUNT OF
MOISTURE WITH IT, GIVEN ITS ORIGIN AND THE MODIFYING AIRMASS WE`LL
HAVE IN PLACE. TOO EARLY FOR PTYPE SPECIFICS BUT IT DOES APPEAR TO
BE ANOTHER MIXED EVENT. THIS SYSTEMS COLD FRONT DRAGS THROUGH RATHER
SLOWLY, AS THE TROUGHING TO OUR WEST SHARPENS AND SLOWS IT DOWN A
BIT. THIS COULD ALLOW FOR A LONGER DURATION EVENT SO WE CARRY CHANCE
POPS THROUGH THE FIRST HALF OF THURSDAY BEFORE DRYING OUT.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS THROUGH THE TAF PERIOD. SOME SCATTERED CLOUDS THIS
AFTERNOON AROUND 5,000 FEET SHOULD CLEAR OUT THIS EVENING BEFORE
CIRRUS ABOVE 10,000 FEET MOVES IN OVERNIGHT. NORTHWESTERY WINDS
FROM 320-350 DEGREES AS WELL, TOP WINDS AROUND 10 KNOTS THIS
AFTERNOON. WIND COULD SHIFT MORE WESTERLY WITH SLIGHTLY LOWERING
CIRRUS IN THE AFTERNOON ON SATURDAY.
OUTLOOK...
SATURDAY NIGHT - SUNDAY MORNING...VFR. NORTHERLY WINDS PREVAIL AS
HIGH PRESSURE NOSES IN FROM THE WEST.
SUNDAY NIGHT - MONDAY...MVFR/IFR EXPECTED WITH SNOW TO
RAIN/FREEZING RAIN POSSIBLE BY EARLY MONDAY MORNING.
TUESDAY...VFR.
&&
.MARINE...
WITH THE MORNING UPDATE WE DID RAISE WAVE HEIGHTS BASED ON BUOY
OBS TO BETWEEN FIVE AND SIX FEET. THIS LEADS TO A HIGHER
CONFIDENCE SCA SEAS WILL PERSIST THROUGH THE LATE AFTERNOON. WINDS
HAVE ALREADY SUBSIDED AND SHOULD REMAIN BELOW SCA CRITERIA TODAY
AND TONIGHT, ALTHOUGH A FEW GUSTS NEAR 20 KT ARE POSSIBLE OVER THE
OCEAN WATERS THIS EVENING. WAVE HEIGHTS SHOULD START TO DECREASE
TONIGHT.
OUTLOOK...
SATURDAY - SUNDAY...SUB-SCA EXPECTED, THOUGH PERSISTENT
NORTHEAST WINDS MAY ALLOW FOR BUILDING SEAS ACROSS OUR SOUTHERN
ZONES.
SUNDAY NIGHT - MONDAY...POSSIBLE SCA CONDITIONS LATE ON SUNDAY
AHEAD OF AN APPROACHING COLD FRONT WITH INCREASING SOUTHERLY
WINDS AND BUILDING SEAS EXPECTED. BETTER CHANCE BEHIND COLD FRONT
PASSAGE ON MONDAY WITH GUSTY WEST WINDS.
TUESDAY...SUB-SCA EXPECTED.
&&
.CLIMATE...
RECORDS FOR FRIDAY AND SATURDAY. NOTE RECORDS FOR FRIDAY UNLIKELY
BUT POSTED JUST IN CASE ONE OR 2 ARE APPROACHED AT 1159 PM FRIDAY
EVENING.
THERE IS A GREATER CHANCE OF RECORDS SATURDAY.
POR / SITE / FEB 27 FEB 28
1872 / KPHL / 6 1900 9 1934
1874 / KACY / 7 1934* 2 1934
1894 / KILG / 5 1934 -5 1934
1922 / KABE / -2 1963 -10 1934
1869 / KRDG / 4 1934* 3 1934
1865 / KTTN / 6 1934 1 1934
1948 / KGED / 10 1963 8 1950
1901 / KMPO / -9 1993 -15 1907
KACY RER FOR 3/1 IS 5 IN 1980.
NOTE: * INDICATE AND OTHER YEARS.
NOTE: POR = PERIOD OF RECORD,THE YEAR OFFICIAL CLIMATE OBS BEGAN.
THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** TOP 5 COLDEST
FEBRUARY`S ON RECORD, BASED ON THE CURRENT FORECAST, AND THUS
SUBJECT TO CHANGE. EACH RANKING DENOTES THE MEAN FEBRUARY
TEMPERATURE /F/ AND YEAR OF OCCURRENCE.
WE REREVIEWED THESE PROJECTIONS LISTED BELOW USING THIS THURSDAY
MORNINGS (26TH) MINS AND THE PHI FCST AS SEEN ON NDFD AND SFT`S. WE
SEE PHL/ABE/ILG ALL VERY CLOSE TO YESTERDAYS PROJECTIONS. KACY
CHANGED TO A WARMER PROJECTION HOWEVER THAT COULD YET REVERT BACK TO
A COLDER MONTHLY AVERAGE DUE TO THE POTENTIAL FOR RADIATIONAL
COOLING ON ONE OR 2 OF THE MORNINGS.
POR / SITE / 1ST RANK / 2ND RANK / 3RD RANK / 4TH RANK / 5TH RANK
1872 / KPHL / 22.2(1934) 23.0(1979) 24.3(1885) 24.6(1978) 25.5(2015)
1874 / KACY / 21.6(1979) 23.8(1978/1934) 24.5(2015) 25.5(1875) 25.7
(1905)
1894 / KILG / 20.2(1934) 22.1(1979) 22.7(1978) 24.5(2015) 24.9(1936)
1922 / KABE / 16.6(1934) 18.9(2015) 20.4(1979) 21.6(1936) 22.0(1963)
PER THE ABOVE TABLE, ABE IS EASILY ON TRACK FOR THE SECOND COLDEST
FEBRUARY, ATLANTIC CITY 3RD COLDEST FOLLOWED BY THE FOURTH COLDEST
AT ILG, AND THE FIFTH COLDEST AT PHL.
THE FOLLOWING IS A TABLE OF THE ***PROJECTED*** MEAN FEBRUARY 2015
TEMPERATURES /F/ AND DEPARTURES FROM NORMAL. THIS IS ALSO BASED ON
THE CURRENT FORECAST, AND THUS SUBJECT TO CHANGE. JANUARY 2015 MEAN
TEMPERATURES ARE ALSO INCLUDED FOR COMPARISON PURPOSES.
POR / SITE / FEB MEAN(F) / FEB NORMAL(F) / DEPARTURE / JAN MEAN(F)
1872 / KPHL / 25.5 / 35.7 / -10.2 / 30.9
1874 / KACY / 24.5 / 35.3 / -10.8 / 30.2
1894 / KILG / 24.5 / 35.1 / -10.6 / 30.3
1922 / KABE / 18.9 / 30.7 / -11.8 / 25.9
IN GENERAL, MEAN TEMPERATURES AT OUR FOUR MAJOR CLIMATE SITES ARE ON
TRACK TO BE AROUND 10 TO 12 DEGREES BELOW NORMAL FOR FEBRUARY 2015.
IT`S ALSO INTERESTING TO NOTE THAT THE PROJECTED FEBRUARY 2015 MEAN
TEMPERATURES WILL BE WELL BELOW THE JANUARY 2015 MEAN TEMPERATURES.
TO PUT THIS IN PERSPECTIVE, NORMAL MEAN FEBRUARY TEMPERATURES AT OUR
FOUR MAJOR CLIMATE SITES ARE ABOUT 2 TO 3 DEGREES WARMER THAN JANUARY.
THE OPPOSITE IS SHAPING UP FOR FEBRUARY 2015.
ALSO...OF INTEREST...THIS WOULD ALSO BE THE SECOND COLDEST MONTHLY
MEAN TEMPERATURE ON RECORD AT ALLENTOWN SINCE RECORDS BEGAN IN
1922; FEBRUARY 1934 BEING THE COLDEST!
PHL PROJECTS AROUND 12TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN IN
1873.
ATLANTIC CITY 7TH COLDEST MONTHLY MEAN SINCE RECORDS BEGAN THERE
IN 1874.
WILMINGTON HAS MISSING DATA IN ITS DATABASE (1897-1916) AND SO WE
DON`T FOCUS AS MUCH ATTENTION ON THAT RECORD.
&&
EQUIPMENT: TEMPERATURE AT GED MAY BE RUNNING SEVERAL DEGREES TO
WARM, TECHS ARE WORKING ON ISSUE. NOT USED IN 12:30 PM UPDATE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 PM EST THIS
AFTERNOON FOR ANZ450>455.
&&
$$
SYNOPSIS...HEAVENER/O`HARA
NEAR TERM...GAINES
SHORT TERM...DRAG/JOHNSON
LONG TERM...HEAVENER
AVIATION...GAINES
MARINE...GAINES/HEAVENER/JOHNSON
CLIMATE...STAFF
EQUIPMENT... GAINES
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
932 PM EST SAT FEB 28 2015
.DISCUSSION...
THE RAINFALL IS BEGINNING TO TAPER OFF THIS EVENING...BUT NOT BEFORE
DUMPING 1 TO 3 INCHES OF RAIN ACROSS THE REGION OVER THE PAST 12
HOURS. MOST OF THIS RAIN WAS ALONG THE I-4 CORRIDOR AND NORTHWARD.
THERE ARE STILL A FEW AREAS THAT ARE PRODUCING MODERATE RAINFALL
MOVING INTO NORTHERN POLK COUNTY...SOUTHERN HIGHLANDS COUNTY AND OVER
CHARLOTTE COUNTY. THE HRRR GUIDANCE HAS THESE POCKETS DISSIPATING BY
MIDNIGHT WITH ONLY ISOLATED SHOWERS EXPECTED OVERNIGHT. THE 00Z
SOUNDING IS SHOWING ABUNDANT MOISTURE THROUGHOUT THE COLUMN WHICH
WILL SUPPORT CONTINUED CLOUDY SKIES THROUGH THE NIGHT. AS FOR
TEMPERATURES...WE ARE NOT LOOKING FOR MUCH CHANGE OVERNIGHT SO
TEMPS SHOULD BOTTOM OUT ABOVE AVERAGE WITH LOWS IN THE UPPER 50S
ALONG THE NATURE COAST AND MID TO UPPER 60S FROM TAMPA BAY
SOUTHWARD. PATCHY FOG WILL ALSO BE POSSIBLE DURING THE EARLY
MORNING HOURS. I MADE SOME MINOR TWEAKS TO POPS TO REFLECT CURRENT
RADAR COVERAGE...EVERYTHING ELSE LOOKS FINE. WILL SEND UPDATED
ZONES WITH THOSE CHANGES SOON.
&&
.AVIATION...
FOR THE MOST PART...CONDITIONS HAVE IMPROVED ACROSS THE REGION WITH
VFR CONDITIONS AT THE NORTHERN TERMINALS AND TEMPO MVFR CONDITIONS
FOR THE SOUTHERN TERMINALS. CONDITIONS ARE EXPECTED TO CONTINUE
IMPROVING AFTER MIDNIGHT WITH VFR REGION WIDE. WINDS WILL REMAIN
OUT OF THE EAST NORTHEAST IN THE 5 TO 10 KNOT RANGE.
&&
.MARINE...
ISOLATED SHOWERS WILL CONTINUE ACROSS THE WATERS THROUGH THE FIRST
PART OF TONIGHT. NORTHEAST WINDS AROUND EXERCISE CAUTION LEVELS FOR
THE NORTHERN WATERS WILL DIMINISH AFTER MIDNIGHT OR SO...WITH THE
REST OF THE ZONES REMAINING BELOW HEADLINES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 63 79 64 80 / 20 20 30 10
FMY 66 84 65 83 / 30 20 20 10
GIF 65 81 64 81 / 30 30 20 20
SRQ 64 79 63 79 / 20 20 20 10
BKV 61 79 58 81 / 30 20 20 20
SPG 65 77 65 78 / 20 20 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...74/WYNN
MARINE...05/CARLISLE
DECISION SUPPORT...09/RUDE
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
225 AM CST FRI FEB 27 2015
.UPDATE...
827 PM CST
LAKE EFFECT SNOW IS STARTING TO WIND DOWN AS DRIER AIR MASS
ADVECTS INTO THE AREA ALLOWING FOR A WEAKENING OF THE BROKEN LES
BAND THAT HAD PERSISTED ALL DAY. AS PROGRESSIVELY DRIER AIR
CONTINUED TO FILTER IN TONIGHT AND EVENTUALLY ONSHORE COMPONENT TO
FLOW WEAKENS WOULD ANTICIPATE LES TO END IN PORTER COUNTY LATER
THIS EVENING OR JUST PAST MIDNIGHT. GIVEN EXPECTATIONS AND RECENT
RADAR TRENDS MAY SHORTEN THE DURATION OF THE LAKE EFFECT SNOW
WARNING IN THE NEXT HOUR OR TWO IF NOT CANCEL IT OUTRIGHT.
ELSEWHERE CLOUDINESS OVER SOUTHERN PORTIONS OF THE CWA IS LIKELY
TO SLOWLY DISSIPATE AND MOVE OUT LEAVING SKIES FAIRLY CLEAR ACROSS
THE AREA. CENTER OF THE HIGH PRESSURE IS STILL HUNDREDS OF MILE TO
OUR NORTHWEST BUT WITH FRESH SNOW PACK WOULD EXPECT GRADIENT TO BE
WEAK ENOUGH FOR WINDS TO FURTHER DECOUPLE OVERNIGHT...ESPECIALLY
WITH HIGH GROWING CLOSER IN TIME. SUSPECT THAT THE WIND CHILL
ADVISORY WILL BE HARD PRESSED TO VERIFY MOST AREAS WITH THE
TYPICALLY COLDER VALLEYS LIKELY SEEING WINDS GO CALM...LIKELY KRPJ
AND KFRD ALREADY HAVE OR WINDS TO STAY UP ENOUGH TO KEEP TEMPS
FROM TANKING. THE TOOTHPASTE IS OUT OF THE PROVERBIAL TUBE SO NOT
PLANNING ANY CHANGES TO THE WIND CHILL ADVISORY SINCE A FEW
LOCATIONS COULD TAG ADVISORY FOR AN HOUR OR TWO AND IT WILL BE
VERY COLD.
IZZI
&&
.SHORT TERM...
THROUGH SATURDAY...
243 PM...LAKE EFFECT IS NOW ORGANIZING INTO A SINGLE BAND AS
WINDS TURN MORE NORTHWEST ACROSS NORTHEAST IL AND THIS BAND IS
SHIFTING TO THE SOUTHEAST AND WILL BE OUT OF COOK COUNTY IN THE
NEXT HOUR OR SO. WILL BE EXPIRING LAKE COUNTY IL FROM THE WARNING
AND FOR NOW WILL LET COOK COUNTY RIDE UNTIL 6 PM...BUT IF CURRENT
TRENDS CONTINUE...IT PROBABLY WILL BE CANCELED EARLY.
HI RES GUIDANCE IS IN REASONABLE AGREEMENT THAT THE LAKE EFFECT
BAND WILL SHIFT INTO PORTER COUNTY BY EARLY/MID EVENING...SO
EXPECTED AMOUNTS IN NORTHERN LAKE COUNTY INDIANA ARE A BIT
UNCERTAIN BUT WITH RATES OF 1-2 INCHES PER HOUR IN THE BAND...ITS
POSSIBLE SOME ISOLATED AMOUNTS OF 3 TO 6 INCHES WILL BE POSSIBLE.
MORE CONFIDENCE WITH AMOUNTS INTO NORTHERN PORTER COUNTY AS THE
BAND REMAINS THERE FROM MID EVENING THROUGH THE OVERNIGHT HOURS
WITH LOCALLY 4 TO 7 INCHES...PERHAPS MOSTLY NEAR THE LAKE. THE
BAND THEN BEGINS TO SHIFT OUT OF THE LAKE TOWARD MORNING. SO NOT
PLANNING ANY CHANGES TO THE WARNING END TIME FOR EITHER LAKE OR
PORTER COUNTIES...THOUGH CONFIDENCE REGARDING WHEN EXACTLY PRECIP
ENDS IS A BIT UNCERTAIN.
HIGH PRESSURE BUILDS ACROSS THE MIDWEST TONIGHT AND THEN MOVES
ACROSS THE AREA ON FRIDAY. WINDS WILL SLOWLY DIMINISH OVERNIGHT
BUT LIKELY REMAIN IN THE 5-10 MPH. THIS COMBINED WITH TEMPS
DROPPING WELL BELOW ZERO AWAY FROM CHICAGO WILL RESULT IN WINDS
CHILLS 20 BELOW TO 25 BELOW ZERO ACROSS THE NORTHERN CWA AND INTO
THE 15 BELOW RANGE SOUTH OF I-80. VALUES ARE BIT MARGINAL INTO
CHICAGO AND ALONG THE I-80 CORRIDOR BUT PLAN TO ISSUE A WIND
CHILL ADVISORY OVERNIGHT INTO FRIDAY MORNING GENERALLY ALONG AND
NORTH OF I-80 IN ILLINOIS.
DESPITE THE LIGHT WINDS AND SUNNY SKIES ON FRIDAY AS THE HIGH
SLOWLY MOVES ACROSS THE AREA...THE AIRMASS WILL REMAIN VERY COLD
WITH HIGHS ONLY REACHING THE MID TO PERHAPS UPPER TEENS. TEMPS
WILL LIKELY TANK FRIDAY NIGHT AS THE HIGH SHIFTS EAST AND LIGHT
WINDS TURN SOUTHERLY. SATURDAY WILL BE DRY AND A BIT WARMER WITH
HIGHS IN THE LOWER/MID 20S WITH INCREASING CLOUDS IN THE
AFTERNOON. CMS
&&
.LONG TERM...
SATURDAY NIGHT THROUGH THURSDAY...
THE TIME FRAME WILL START OUT ACTIVE AS A PERIOD OF ACCUMULATING
SNOW IS APPEARING LIKELY SATURDAY NIGHT INTO SUNDAY. STEADILY
INCREASING UPPER LEVEL FLOW OUT AHEAD OF DIGGING TROUGH TO THE
NORTH WILL ALLOW SHORT WAVE ENERGY TO TRAVERSE THE REGION DURING
THIS PERIOD...WHILE ONGOING WAA PERSISTS. THIS SHOULD ALLOW SNOW
TO SPREAD NORTHEAST ACROSS THE CWA DURING THE EVENING HOURS WITH
SNOW LIKELY ACROSS MUCH OF THE CWA AFTER THE MIDNIGHT TIME
FRAME...THEN LIKELY CONTINUING INTO SUNDAY AFTERNOON. MOST
GUIDANCE IN AGREEMENT WITH OVERALL LARGE SCALE SETUP DURING THIS
TIME AND EVEN WITH THIS SNOW SPREADING OVER THE CWA.
HOWEVER...THERE DOES APPEAR TO BE SOME TIMING DIFFERENCES OF THE
ONSET AND TIMING OF BEST SNOWFALL. SO I DO FEEL IT WILL SNOW AND
HAVE LIKELY POPS OVER THE ENTIRE CWA LATE SATURDAY NIGHT INTO
SUNDAY MORNING...BUT DID NOT GO TO CATEGORICAL BASED ON THE
PREVIOUSLY MENTIONED UNCERTAINTIES. ONLY MINOR CHANGES MADE TO THE
CURRENT SNOW FORECAST WITH THE BEST FORCING AND HIGHEST SNOWFALL
TOTALS CURRENTLY EXPECTED TO BE SOUTH OF I80. WHILE MOST OF THE
CWA WILL LIKELY OBSERVE ACCUMULATING SNOWFALL...THE SOUTHERN CWA
COULD APPROACH ADVISORY TYPE SNOW. HOWEVER I WONDER IF MY CURRENT
TOTAL MIGHT BE A LITTLE TOO HIGH...ESPECIALLY WITH THE ANTICIPATED
DRIVING MECHANISMS OF THIS SNOW...BUT THE LONGER DURATION OF THIS
LIGHT TO AT TIME MODERATE SNOW COULD HELP FOR THE CURRENT FORECAST
TOTALS. SYSTEM SNOW WILL DEPART TO THE EAST LATE SUNDAY AND SUNDAY
EVENING...AS HIGH PRESSURE BUILDS ACROSS THE REGION.
EARLY NEXT WEEK APPEARS TO BEGIN QUIET...BUT WITH ACTIVE WEATHER
RETURNING THROUGH MIDWEEK. HIGHLY AMPLIFIED PATTERN WITH UPPER
LEVEL RIDGE OVER THE EASTERN US AND A DIGGING TROUGH OVER THE
WESTERN CONUS WILL BE IN PLACE ON TUESDAY...AS DEEPENING SURFACE
LOW APPROACHES THE CWA FROM THE SOUTHWEST. STRONG WARM AIR AND
MOIST ADVECTION IS ANTICIPATED MONDAY NIGHT AND ESPECIALLY
TUESDAY/TUESDAY NIGHT. THIS WILL NOT ONLY PROVIDE THE POTENTIAL
FOR INITIAL VARYING PRECIP TYPE BUT WITH ALSO STEADIER
RAINFALL...AS A BROAD AREA OF PRECIP IS EXPECTED TO ACCOMPANY THIS
SYSTEM. EC AND GFS SIMILAR WITH REGARDS TO WAA...BUT WITH THE GFS
NOT AS ROBUST WITH THE MOISTURE ADVECTION AS THE EC IS APPEARING
TO BE. IF THE EC WERE TO VERIFY...THEN SURFACE DEWPOINTS COULD
APPROACH 50 DEG AND 850MB DEWPOINTS APPROACHING 10-11C. THIS WILL
BE CONCERNING FOR POSSIBLE HYDRO ISSUES...ESPECIALLY WITH THE
ANTICIPATED SNOW THIS WEEKEND. THERMAL PROFILES SUPPORTIVE OF ALL
RAIN ON TUESDAY AND ALTHOUGH I HAVENT INCLUDED THUNDER IN THE
GRIDS AT THIS TIME...WILL NEED TO MONITOR THIS POTENTIAL AS
WELL...ESPECIALLY FOR THE SOUTHERN CWA.
RODRIGUEZ
&&
.CLIMATE...
TEMPERATURES ARE FORECAST ONCE AGAIN TO BE CLOSE OR BREAK THE
FOLLOWING DAILY RECORDS THROUGH THE END OF THE MONTH...INCLUDING
ONE ON FRIDAY IN ROCKFORD THAT WAS SET JUST LAST WINTER:
ROCKFORD...
FRIDAY FEB 27TH LOW MAXIMUM: 15 IN 2014
SATURDAY FEB 28TH LOW: -7 IN 1962
SATURDAY FEB 28TH LOW MAXIMUM: 17 IN 1962
CHICAGO...
FRIDAY FEB 27TH LOW: -6 IN 1897
SATURDAY FEB 28TH LOW: 0 IN 1884
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NONE.
RATZER
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE CENTERED OVER THE MID-MISSOURI VALLEY EARLY THIS
MORNING WILL SPREAD SLOWLY EAST-SOUTHEAST ACROSS THE REGION
THROUGH TONIGHT. LIGHT NORTHWEST WINDS WILL BECOME WEST DURING THE
DAY AND SOUTHWEST TONIGHT...WITH SPEEDS GENERALLY LESS THAN 10 KT.
DRY ARCTIC AIR MASS WILL MAKE FOR MAINLY CLEAR SKIES THROUGH THE
PERIOD.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH FOR ALL ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR THEN SNOW DEVELOPING SATURDAY NIGHT. IFR LIKELY.
SUNDAY...PERIODS OF ACCUMULATING SNOW ENDING BY LATE AFTERNOON.
IFR LIKELY.
MONDAY...VFR THEN CHANCE OF WINTRY MIX AND IFR MONDAY NIGHT.
TUESDAY...RAIN AND IFR LIKELY...POSSIBLY ENDING AS LIGHT SNOW
TUESDAY NIGHT. IFR
WEDNESDAY...MVFR POSSIBLE.
RC
&&
.MARINE...
219 AM CST
MAIN PERIOD OF CONCERN FOR GUSTY 20-30 KT WINDS LOOKS TO BE SUNDAY
NIGHT INTO EARLY MONDAY...AND POTENTIALLY AGAIN ON WEDNESDAY. MUCH
OF LAKE REMAINS ICE COVERED...WITH ONLY THE CENTRAL AND SOUTHERN
PORTIONS WELL AWAY FROM SHORE APPEARING OPEN IN RECENT SATELLITE
DATA.
HIGH PRESSURE CENTERED OVER THE MID-MISSOURI RIVER VALLEY WILL MOVE
EAST-SOUTHEAST ACROSS THE MIDWEST SOUTH OF THE LAKES THROUGH TONIGHT
AND TO THE MID-ATLANTIC REGION BY LATE SATURDAY. MEANWHILE...LOW
PRESSURE WILL MOVE ACROSS HUDSON BAY TODAY...WITH A DEEPER TROUGH
DEVELOPING NORTH OF THE LAKES SATURDAY. THIS WILL RESULT IN WINDS
BECOMING WESTERLY OVER LAKE MICHIGAN TODAY...INCREASING A BIT INTO
THE 20 KT RANGE TONIGHT AS THE GRADIENT TIGHTENS UP BETWEEN THE HIGH
PASSING SOUTH OF THE LAKES AND LOW PRESSURE FARTHER TO THE NORTH.
SATURDAY INTO SUNDAY...WINDS WILL SHIFT TO THE SOUTH-SOUTHWEST AS A
COLD FRONTAL TROUGH APPROACHES FROM THE NORTHWEST. THE FRONT WILL
PASS ACROSS THE LAKE SUNDAY WITH A SHIFT BACK TO THE WEST...BECOMING
NORTHWEST AND BECOMING GUSTY 25-30 KT SUNDAY NIGHT INTO MONDAY
MORNING AS HIGH PRESSURE MOVES IN FROM THE WEST AND BRIEFLY TIGHTENS
THE GRADIENT ONCE AGAIN. THE HIGH WILL MOVE ACROSS THE SOUTHERN
LAKES AND MIDWEST MONDAY WITH NORTHWEST WINDS QUICKLY DIMINISHING
AND EVENTUALLY BECOMING SOUTHEASTERLY MONDAY NIGHT AS THE HIGH
SLIDES OFF TO THE EAST.
MEDIUM-RANGE MODEL RUNS INDICATE LOW PRESSURE WILL MOVE NEAR
SOUTHERN LAKE MICHIGAN TUESDAY OR TUESDAY NIGHT. CURRENT INDICATIONS
ARE THAT SOUTHEAST WINDS WILL INCREASE TUESDAY INTO THE 20 KT RANGE
OR SO...BEFORE BRIEFLY DECREASING AND VEERING NORTH-NORTHWEST BY
EARLY WEDNESDAY AND INCREASING INTO THE 25-30 KT RANGE AS COLDER AIR
ONCE AGAIN SURGES IN.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022
UNTIL 9 AM FRIDAY.
IN...LAKE EFFECT SNOW WARNING...INZ002 UNTIL 6 AM FRIDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1139 PM CST Thu Feb 26 2015
.UPDATE...
ISSUED AT 900 PM CST THU FEB 26 2015
Small area of clouds continues to slowly move south this evening.
Also, some isolated flurries are also still occurring under this
cloud cover. Expect this to continue, mainly in eastern areas of
the CWA. This will eventually clear up overnight. Current forecast
has a good handle on this and with temp trends the rest of the
night. No update planned at this time.
&&
.SHORT TERM...(Tonight)
ISSUED AT 249 PM CST THU FEB 26 2015
Will issue a wind chill advisory for areas along and north of a
Jacksonville to Springfield to Decatur to Paris line overnight into
mid Fri morning for wind chills of 15-24F below zero with the
coldest wind chills in Knox and Stark counties around dawn Friday.
Wind chills reach near or below 15F below near Galesburg around
midnight, and se toward I-72 later tonight. Lows overnight to
range from 5-10F below zero from the IL river valley nw to zero to
5F above in southeast IL from I-70 se. Broken to overcast low
clouds still cover much of IL with some clearing far west central
and northern IL near WI border. Still getting scattered light snow
showers and areas of flurries over central IL (visibilities as low as
2-5 miles) due to lingering moisture off lake MI along with a short
wave dropping se into the area. HRRR may be a bit too progressive in
clearing low clouds from north to south during early and mid
evening. Low clouds to likely decrease over IL river valley early
this evening, but thinking it may take until overnight for
decreasing of low clouds in southeast IL since short wave still
affecting southern counties tonight. Also lingered chance of
flurries from I-55 east late this afternoon and early evening and
into mid evening in southeast IL. Strong 1042 mb arctic high
pressure near the MT/ND and southern Saskatchewan border and ridging
SSE into the Great Plains to settle se into IA/MO by Friday morning
bringing dry weather and bitter cold temperatures overnight into Fri
morning. North winds 10-17 mph and gusts 18-24 mph this afternoon
will veer nw and decrease to 5-10 mph overnight.
&&
.LONG TERM...(Friday through Thursday)
ISSUED AT 249 PM CST THU FEB 26 2015
Morning upper air and satellite imagery depicts trough over the
central plains with clipper shortwave moving over IL, producing
continued light snow in strong 850mb cold air advection. Wave
continuing to move east and will break up in afternoon.
Ridge of high pressure to build in overnight, again producing wind
chills. Ridge to move off to the east through Friday and into
Saturday. By Saturday afternoon, overrunning from the next system
begins to develop into plains. NAM model brings snow into western IL
and feel not unreasonable. Will therefore add slight chc pops Sat
afternoon, with main pcpn Sat night to Sunday.
Models similar in development of frontal zone from western plains
low into Ozarks, with significant lift over boundary Saturday night.
This will push snow formation into central IL Saturday night,
continuing into Sunday. Main lift is Saturday night as upper wave
moves across great lakes, with pcpn lingering into Sunday. Diminshed
the pcpn Sun night as high pressure builds in.
Upper flow changes Monday to Tuesday, with pcpn again developing
into Monday night to Tuesday as surface low center develops in
plains and moves northeast, west of cwa though. The result is that
with this feature, area stays in the warm section and so pcpn starts
as freezing rain and changes to rain. Still uncertainty though, as
the operational models are very different on the timing of the
system movement. made few changes due to these differences.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1139 PM CST THU FEB 26 2015
VFR conditions will prevail at all TAF sites next 24hrs. Clouds
around 4.5kft are still effecting BMI/DEC/CMI late tonight but are
slowly moving southeast and should clear BMI and DEC by 06z, and
CMI by 09z. Will keep a 2hr TEMPO group for DEC and CMI just
because it seems these clouds are just lingering and will not go
quickly. Then clear skies should prevail remainder of the TAF
period. Winds will be northwest overnight and then become light
and variable tomorrow.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY until 10 AM CST Friday FOR ILZ027>031-
036>038-040>051-053-055-057.
&&
$$
UPDATE...Auten
SHORT TERM...07
LONG TERM...Goetsch
AVIATION...Auten
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
309 PM EST FRI FEB 27 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 303 AM EST FRI FEB 27 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A
FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1025 AM EST FRI FEB 27 2015
CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING
ADVISORY CRITERIA.
OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST
OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS
AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY.
RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20
SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN
MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF
SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS
THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 303 AM EST FRI FEB 27 2015
DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH
PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST
DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP
SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE
REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO
IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED
WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT.
WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON
ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT
PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER
ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX
OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS
FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM
AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE
NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE
STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE
PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE
TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS
SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES.
BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE
FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE
GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON
SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL
NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 230 PM EST FRI FEB 27 2015
MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS
ACCEPTED FOR MOST ITEMS.
SOUTHWEST FLOW ALOFT IN THE FIRST PART OF THE LONG TERM WILL ALLOW
NEAR TO ABOVE AVERAGE TEMPERATURES AS AN AREA OF LOW PRESSURE MOVES
TO THE NORTH OF CENTRAL INDIANA. HOWEVER AN UPPER TROUGH WILL MOVE
INTO THE AREA FOR THE END OF THE PERIOD ALLOWING WELL BELOW NORMAL
TEMPERATURES ONCE AGAIN.
LOOKS LIKE PRECIPITATION WILL MAINLY ARRIVE OVERNIGHT MONDAY NIGHT
INTO EARLY TUESDAY. MODELS STILL ARE BRINGING IN WARM AIR ALOFT
QUICKLY...SO MIXED PRECIPITATION TO FREEZING RAIN LOOKS TO BE THE
PRECIPITATION TYPE MONDAY NIGHT.
SURFACE TEMPERATURES STILL LOOK TO BE COLD TUESDAY MORNING SO KEPT
THE FREEZING RAIN MENTION THEN. AS WARM AIR AT THE SURFACE FINALLY
ARRIVES RAIN WILL FALL LATER TUESDAY MORNING THROUGH THE REMAINDER
OF THE DAY. COULD BE ENOUGH RAIN TO CAUSE SOME FLOODING ISSUES GIVEN
THE FROZEN GROUND. WILL CONTINUE TO MONITOR CLOSELY.
MODELS DIFFER IN SPEED OF COLD AIR RETURNING TUESDAY NIGHT BUT STILL
FEEL IT A MIX OF RAIN AND SNOW IS WARRANTED AS PRECIPITATION TYPE
MOST AREAS. AS A WAVE RIDES ALONG THE FRONT ON WEDNESDAY
PRECIPITATION CHANCES WILL CONTINUE...WITH CHANCES FOR SNOW
NORTHWEST AND RAIN/SNOW SOUTHEAST.
THURSDAY AND FRIDAY LOOK TO BE DRY AND COLD WITH HIGH PRESSURE
MOVING IN.
&&
.AVIATION /DISCUSSION FOR THE 27/2100Z TAF UPDATE/...
ISSUED AT 307 PM EST FRI FEB 27 2015
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT.
SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL
DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH
CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM.
WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN
10KT SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JH
SHORT TERM...JAS
LONG TERM....50
AVIATION...50/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
230 PM EST FRI FEB 27 2015
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 303 AM EST FRI FEB 27 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A
FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1025 AM EST FRI FEB 27 2015
CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING
ADVISORY CRITERIA.
OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST
OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS
AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY.
RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20
SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN
MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF
SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS
THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 303 AM EST FRI FEB 27 2015
DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH
PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST
DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP
SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE
REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO
IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED
WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT.
WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON
ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT
PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER
ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX
OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS
FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM
AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE
NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE
STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE
PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE
TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS
SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES.
BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE
FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE
GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON
SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL
NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 230 PM EST FRI FEB 27 2015
MODELS ARE CLOSE ENOUGH THAT THE SUPERBLEND INITIALIZATION WAS
ACCEPTED FOR MOST ITEMS.
SOUTHWEST FLOW ALOFT IN THE FIRST PART OF THE LONG TERM WILL ALLOW
NEAR TO ABOVE AVERAGE TEMPERATURES AS AN AREA OF LOW PRESSURE MOVES
TO THE NORTH OF CENTRAL INDIANA. HOWEVER AN UPPER TROUGH WILL MOVE
INTO THE AREA FOR THE END OF THE PERIOD ALLOWING WELL BELOW NORMAL
TEMPERATURES ONCE AGAIN.
LOOKS LIKE PRECIPITATION WILL MAINLY ARRIVE OVERNIGHT MONDAY NIGHT
INTO EARLY TUESDAY. MODELS STILL ARE BRINGING IN WARM AIR ALOFT
QUICKLY...SO MIXED PRECIPITATION TO FREEZING RAIN LOOKS TO BE THE
PRECIPITATION TYPE MONDAY NIGHT.
SURFACE TEMPERATURES STILL LOOK TO BE COLD TUESDAY MORNING SO KEPT
THE FREEZING RAIN MENTION THEN. AS WARM AIR AT THE SURFACE FINALLY
ARRIVES RAIN WILL FALL LATER TUESDAY MORNING THROUGH THE REMAINDER
OF THE DAY. COULD BE ENOUGH RAIN TO CAUSE SOME FLOODING ISSUES GIVEN
THE FROZEN GROUND. WILL CONTINUE TO MONITOR CLOSELY.
MODELS DIFFER IN SPEED OF COLD AIR RETURNING TUESDAY NIGHT BUT STILL
FEEL IT A MIX OF RAIN AND SNOW IS WARRANTED AS PRECIPITATION TYPE
MOST AREAS. AS A WAVE RIDES ALONG THE FRONT ON WEDNESDAY
PRECIPITATION CHANCES WILL CONTINUE...WITH CHANCES FOR SNOW
NORTHWEST AND RAIN/SNOW SOUTHEAST.
THURSDAY AND FRIDAY LOOK TO BE DRY AND COLD WITH HIGH PRESSURE
MOVING IN.
&&
.AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/...
ISSUED AT 1142 AM EST FRI FEB 27 2015
VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT.
SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL
DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH
CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM.
WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN
10KT SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
IND...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JH
SHORT TERM...JAS
LONG TERM....50
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1142 AM EST FRI FEB 27 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 303 AM EST FRI FEB 27 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A
FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1025 AM EST FRI FEB 27 2015
CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING
ADVISORY CRITERIA.
OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST
OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS
AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY.
RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20
SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN
MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF
SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS
THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 303 AM EST FRI FEB 27 2015
DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH
PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST
DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP
SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE
REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO
IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED
WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT.
WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON
ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT
PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER
ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX
OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS
FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM
AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE
NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE
STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE
PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE
TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS
SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES.
BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE
FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE
GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON
SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL
NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 258 AM EST FRI FEB 27 2015
ACTIVE PATTERN CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK AS
PIECES OF ENERGY ALOFT EJECT OUT OF THE TROUGH OVER THE WESTERN U S
FOLLOWED BY THE TROUGH AXIS ITSELF MOVING EAST INTO THE REGION BY
THE END OF THE PERIOD. HIGH CONFIDENCE IN A SIGNIFICANT WEATHER
IMPACT FOR CENTRAL INDIANA AND THE OHIO VALLEY MONDAY NIGHT THROUGH
WEDNESDAY.
STRONG HIGH PRESSURE ARRIVES IN THE WAKE OF THE LATE WEEKEND SYSTEM
FOR MONDAY...AND SHOULD SERVE TO GIVE THE REGION A BREATHER BETWEEN
WEATHER SYSTEMS ON THE ORDER OF 18 TO 24 HOURS. SURFACE WAVE SET
TO SPIN UP OVER THE CENTRAL ROCKIES MONDAY NIGHT AS ENERGY EJECTS
OUT FROM THE PARENT TROUGH. THIS FEATURE WILL SWING E/NE AND TRACK
QUICKLY INTO THE REGION BY TUESDAY EVENING AND BRING WITH IT A
PLETHORA OF MESSY PROBLEMS FOR CENTRAL INDIANA. RIDGING DEVELOPING
DOWNSTREAM OF THE TROUGH SUPPORTS MORE AMPLIFIED FLOW WITH THE
SURFACE WAVE TRACKING THROUGH OR NORTH OF THE FORECAST AREA. OP GFS
SHOWING ITS USUAL PROGRESSIVE BIAS IN THE MID RANGE IN BRINGING
PRECIP IN TOO QUICKLY...ESPECIALLY CONSIDERING THE STRENGTH OF THE
DEPARTING HIGH. LIKE THE LOOK OF THE ECMWF/GGEM WHICH DELAYS MOST
PRECIP UNTIL AFTER MIDNIGHT MONDAY NIGHT.
WARM ADVECTION WILL ALREADY BE ONGOING WHEN PRECIP STARTS...AND
EXPECT PRECIP TYPE ISSUES FROM THE GET GO WITH A GROWING LIKELIHOOD
THAT FREEZING RAIN IS THE PREDOMINANT PRECIP TYPE INTO TUESDAY
MORNING. THE REFRESHED SNOWPACK COURTESY OF THE WEEKEND STORM WILL
BE A SIGNIFICANT FACTOR IN DURATION OF FROZEN PRECIP AS THE NEAR
SURFACE/GROUND TEMPS WILL LAG THE LOW LEVEL TEMP RISES. MODEL
THERMAL PROFILES ARE ALREADY SUGGESTIVE THAT IT MAY TAKE UNTIL
MIDDAY TUESDAY IN SOME PORTIONS OF THE REGION TO WARM SUFFICIENTLY
FOR ALL RAIN. IF THE IMPACT OF THE SNOWCOVER IS UNDERMINED BY THE
MODELS WHATSOEVER...THE ICING POTENTIAL COULD BE EVEN MORE
SIGNIFICANT. DO NOT EXPECT TO HAVE A GOOD HANDLE ON THIS UNTIL LATER
IN THE WEEKEND.
WHILE THE ICING THREAT IS A GROWING ISSUE...AN EXTENDED PERIOD OF
HEAVY RAIN OVER A FROZEN GROUND AND SNOW COVER POSES EVEN GREATER
CONCERNS. COPIOUS AMOUNTS OF MOISTURE WILL BE DRAWN NORTH INTO THE
REGION AHEAD OF THE APPROACHING SURFACE WAVE TUESDAY AND TUESDAY
NIGHT. PRECIP WATER VALUES ARE PARTICULARLY ALARMING...MAXING OUT
BETWEEN 1.25 AND 1.50 INCHES TUESDAY EVENING. THESE LEVELS WOULD
PLACE THE REGION NEAR AND ABOVE THE 99TH PERCENTILE FOR
CLIMATOLOGICAL PRECIP WATER VALUES IN MARCH. POTENTIAL FOR
CONVECTIVE ELEMENTS TO THE PRECIP AS WELL AND MAY NEED TO ADD AN
ISOLATED THUNDER MENTION INTO THE FORECAST FOR TUESDAY
AFTERNOON/NIGHT. 1-2 INCHES OF RAINFALL CERTAINLY LOOK PLAUSIBLE AND
WITH MOST OF THIS BEING CONVERTED TO PURE RUNOFF WITH THE FROZEN
GROUND...FLOODING CONCERNS ARE VALID. FRONTAL BOUNDARY SHOULD
FINALLY MOVE EAST WEDNESDAY WITH PRECIP ENDING LATE DAY...LIKELY AS
A RAIN/SNOW MIX. MUCH COLDER AIR WILL THEN RETURN FOR THE END OF THE
WEEK.
STILL PLENTY TO HASH OUT AND THE WEEKEND WINTER STORM WILL HAVE SOME
SAY IN HOW THIS ALL TRANSPIRES. AS STATED ABOVE THOUGH...CONFIDENCE
IS HIGH IN SIGNIFICANT WEATHER IMPACTS FOR CENTRAL INDIANA MONDAY
NIGHT THROUGH WEDNESDAY...WITH ICING...HEAVY RAIN AND FLOODING ALL
POTENTIAL CONCERNS. ENCOURAGE HOOSIERS TO STAY ABREAST OF THE
FORECAST OVER THE NEXT FEW DAYS.
&&
.AVIATION /DISCUSSION FOR 271800Z TAF ISSUANCE/...
ISSUED AT 1142 AM EST FRI FEB 27 2015
VFR EXPECTED THROUGH THE PERIOD WITH WINDS GENERALLY LESS THAN 10KT.
SCATTERED /TO PERHAPS BRIEFLY BROKEN AT KIND/KBMG/ CU FIELD WILL
DISSIPATE WITH LOSS OF HEATING NEAR SUNSET. OTHERWISE MID AND HIGH
CLOUDS WILL INCREASE TONIGHT AND SATURDAY AHEAD OF NEXT SYSTEM.
WINDS WILL BECOME LIGHT THIS EVENING AND THEN SOUTHEAST AT LESS THAN
10KT SATURDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
IND...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JH
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EST FRI FEB 27 2015
.UPDATE...
NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 303 AM EST FRI FEB 27 2015
HIGH PRESSURE IS EXPECTED ACROSS THE AREA THROUGH SATURDAY. A
FRONTAL SYSTEM IS EXPECTED TO MOVES THROUGH THE AREA FRONT SATURDAY
NIGHT INTO SUNDAY NIGHT. A STRONGER LOW PRESSURE SYSTEM MAY AFFECT
THE AREA TOWARDS THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1025 AM EST FRI FEB 27 2015
CANCELLED WIND CHILL ADVISORY AS WIND CHILLS ARE NO LONGER REACHING
ADVISORY CRITERIA.
OTHERWISE...SATELLITE INDICATES MOSTLY CLEAR SKIES WERE ACROSS MOST
OF THE AREA. RUC MODEL SOUNDINGS INDICATE CU MAY INCREASE THIS
AFTERNOON CAUSING SKIES TO BECOME PARTLY CLOUDY.
RUC SOUNDINGS INDICATE HIGHS FROM MIDDLE TEENS NORTH TO AROUND 20
SOUTH WHICH IS CLOSE TO CURRENT FORECAST AND A LITTLE WARMER THAN
MOST MOS GUIDANCE. THIS SEEMS REASONABLE. THERE SHOULD BE A LOT OF
SUNSHINE AT LEAST THROUGH MID DAY AND THEN A LITTLE MORE CLOUDINESS
THIS AFTERNOON. REST OF NEAR TERM SEEMS TO BE ON TRACK.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 303 AM EST FRI FEB 27 2015
DRY CONDITIONS EXPECTED TONIGHT AND SATURDAY AS SURFACE HIGH
PRESSURE GRADUALLY SHIFTS OFF TO THE EAST. MAIN ITEM OF INTEREST
DURING THIS PERIOD IS A SHORT WAVE TROUGH THAT IS EXPECTED TO DROP
SOUTHEAST ACROSS THE GREAT LAKES SUNDAY NIGHT. THE SURFACE
REFLECTION ASSOCIATED WITH THIS FEATURE DOESN/T LOOK TOO
IMPRESSIVE...BUT MODELS SUGGEST A 40 KT LOW LEVEL JET ASSOCIATED
WITH THIS FEATURE...WHICH SHOULD PROVIDE QUITE A BIT OF LIFT.
WILL BRING IN HIGH POPS BY LATE SATURDAY NIGHT AND SUNDAY BASED ON
ABOVE REASONING...WITH POPS TAPERING OFF SUNDAY NIGHT AS MAIN LIFT
PUSHES OFF TO THE EAST. OPERATIONAL MODELS SUGGEST MAINLY SNOW OVER
ABOUT THE NORTHERN HALF OF THE FORECAST AREA...WITH MORE OF A MIX
OVER THE SOUTHERN HALF...WHICH GOES ALONG WITH THE PREVIOUS
FORECAST. HOWEVER...THE ENSEMBLES SUGGEST A STRONGER PUSH OF WARM
AIR IS POSSIBLE...WITH POTENTIAL FOR RAIN AS FAR NORTH AS THE
NORTHERN ZONES BY SUNDAY. CAN/T RULE OUT THESE SOLUTIONS GIVEN THE
STRENGTH OF THE LOW LEVEL JET. FOR NOW...WILL STICK WITH THE
PREVIOUS FORECAST REGARDING PRECIPITATION TYPES AND MONITOR THE
TRENDS. SEVERAL INCHES OF SNOW ARE POSSIBLE WITH THIS
SYSTEM...ESPECIALLY OVER THE NORTHERN ZONES.
BASED ON LOW LEVEL THICKNESSES...THE GFS MOS TEMPERATURE GUIDANCE
FOR TONIGHT AND SATURDAY LOOK A LITTLE COLD. WILL BUMP UP THE
GUIDANCE A FEW DEGREES IN THOSE PERIODS. THE GUIDANCE HIGHS ON
SUNDAY LOOK TOO WARM CONSIDERING EXPECTED PRECIPITATION...SO WILL
NUDGE THOSE NUMBERS DOWN ABOUT A CATEGORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 258 AM EST FRI FEB 27 2015
ACTIVE PATTERN CONTINUES THROUGH THE FIRST HALF OF NEXT WEEK AS
PIECES OF ENERGY ALOFT EJECT OUT OF THE TROUGH OVER THE WESTERN U S
FOLLOWED BY THE TROUGH AXIS ITSELF MOVING EAST INTO THE REGION BY
THE END OF THE PERIOD. HIGH CONFIDENCE IN A SIGNIFICANT WEATHER
IMPACT FOR CENTRAL INDIANA AND THE OHIO VALLEY MONDAY NIGHT THROUGH
WEDNESDAY.
STRONG HIGH PRESSURE ARRIVES IN THE WAKE OF THE LATE WEEKEND SYSTEM
FOR MONDAY...AND SHOULD SERVE TO GIVE THE REGION A BREATHER BETWEEN
WEATHER SYSTEMS ON THE ORDER OF 18 TO 24 HOURS. SURFACE WAVE SET
TO SPIN UP OVER THE CENTRAL ROCKIES MONDAY NIGHT AS ENERGY EJECTS
OUT FROM THE PARENT TROUGH. THIS FEATURE WILL SWING E/NE AND TRACK
QUICKLY INTO THE REGION BY TUESDAY EVENING AND BRING WITH IT A
PLETHORA OF MESSY PROBLEMS FOR CENTRAL INDIANA. RIDGING DEVELOPING
DOWNSTREAM OF THE TROUGH SUPPORTS MORE AMPLIFIED FLOW WITH THE
SURFACE WAVE TRACKING THROUGH OR NORTH OF THE FORECAST AREA. OP GFS
SHOWING ITS USUAL PROGRESSIVE BIAS IN THE MID RANGE IN BRINGING
PRECIP IN TOO QUICKLY...ESPECIALLY CONSIDERING THE STRENGTH OF THE
DEPARTING HIGH. LIKE THE LOOK OF THE ECMWF/GGEM WHICH DELAYS MOST
PRECIP UNTIL AFTER MIDNIGHT MONDAY NIGHT.
WARM ADVECTION WILL ALREADY BE ONGOING WHEN PRECIP STARTS...AND
EXPECT PRECIP TYPE ISSUES FROM THE GET GO WITH A GROWING LIKELIHOOD
THAT FREEZING RAIN IS THE PREDOMINANT PRECIP TYPE INTO TUESDAY
MORNING. THE REFRESHED SNOWPACK COURTESY OF THE WEEKEND STORM WILL
BE A SIGNIFICANT FACTOR IN DURATION OF FROZEN PRECIP AS THE NEAR
SURFACE/GROUND TEMPS WILL LAG THE LOW LEVEL TEMP RISES. MODEL
THERMAL PROFILES ARE ALREADY SUGGESTIVE THAT IT MAY TAKE UNTIL
MIDDAY TUESDAY IN SOME PORTIONS OF THE REGION TO WARM SUFFICIENTLY
FOR ALL RAIN. IF THE IMPACT OF THE SNOWCOVER IS UNDERMINED BY THE
MODELS WHATSOEVER...THE ICING POTENTIAL COULD BE EVEN MORE
SIGNIFICANT. DO NOT EXPECT TO HAVE A GOOD HANDLE ON THIS UNTIL LATER
IN THE WEEKEND.
WHILE THE ICING THREAT IS A GROWING ISSUE...AN EXTENDED PERIOD OF
HEAVY RAIN OVER A FROZEN GROUND AND SNOW COVER POSES EVEN GREATER
CONCERNS. COPIOUS AMOUNTS OF MOISTURE WILL BE DRAWN NORTH INTO THE
REGION AHEAD OF THE APPROACHING SURFACE WAVE TUESDAY AND TUESDAY
NIGHT. PRECIP WATER VALUES ARE PARTICULARLY ALARMING...MAXING OUT
BETWEEN 1.25 AND 1.50 INCHES TUESDAY EVENING. THESE LEVELS WOULD
PLACE THE REGION NEAR AND ABOVE THE 99TH PERCENTILE FOR
CLIMATOLOGICAL PRECIP WATER VALUES IN MARCH. POTENTIAL FOR
CONVECTIVE ELEMENTS TO THE PRECIP AS WELL AND MAY NEED TO ADD AN
ISOLATED THUNDER MENTION INTO THE FORECAST FOR TUESDAY
AFTERNOON/NIGHT. 1-2 INCHES OF RAINFALL CERTAINLY LOOK PLAUSIBLE AND
WITH MOST OF THIS BEING CONVERTED TO PURE RUNOFF WITH THE FROZEN
GROUND...FLOODING CONCERNS ARE VALID. FRONTAL BOUNDARY SHOULD
FINALLY MOVE EAST WEDNESDAY WITH PRECIP ENDING LATE DAY...LIKELY AS
A RAIN/SNOW MIX. MUCH COLDER AIR WILL THEN RETURN FOR THE END OF THE
WEEK.
STILL PLENTY TO HASH OUT AND THE WEEKEND WINTER STORM WILL HAVE SOME
SAY IN HOW THIS ALL TRANSPIRES. AS STATED ABOVE THOUGH...CONFIDENCE
IS HIGH IN SIGNIFICANT WEATHER IMPACTS FOR CENTRAL INDIANA MONDAY
NIGHT THROUGH WEDNESDAY...WITH ICING...HEAVY RAIN AND FLOODING ALL
POTENTIAL CONCERNS. ENCOURAGE HOOSIERS TO STAY ABREAST OF THE
FORECAST OVER THE NEXT FEW DAYS.
&&
.AVIATION /DISCUSSION FOR 271500Z TAF UPDATE/...
ISSUED AT 920 AM EST FRI FEB 27 2015
ONLY TWEAKED KIND WIND DIRECTION. STILL SOME UNCERTAINTY ON WHERE
BROKEN CUMULUS FIELD WILL SET UP...SO LEFT FORECAST ALONE FOR NOW.
PREVIOUS DISCUSSION FOLLOWS...
VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.
HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TODAY WITH PARTLY
CLOUDY SKIES. POCKETS OF STRATOCU CONTINUE TO DROP INTO CENTRAL
INDIANA WITH LOW LEVEL FLOW OFF LAKE MICHIGAN. DESPITE THE DRIER
AIR AND SUBSIDENCE OVERSPREADING THE REGION TODAY...COLD POOL
ALOFT AND PRESENCE OF 850MB THERMAL TROUGH BOTH SUPPORT RENEWED CU
DEVELOPMENT FOR THE AFTERNOON...ESPECIALLY AT KBMG AND KIND.
AS CU SCATTERS OUT LATER THIS AFTERNOON...MID AND HIGH LEVEL
CLOUDS WILL INCREASE FROM THE SOUTHWEST FOR TONIGHT IN ADVANCE OF
A SYSTEM DEVELOPING OVER THE SOUTHERN PLAINS. SKIES WILL BECOME
OVERCAST AFTER MIDNIGHT AS CEILINGS LOWER TO 8-10KFT. NORTHWEST
WINDS AT 5-10KTS TODAY WILL EVENTUALLY BECOME LIGHT AND VARIABLE
OVERNIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
IND...NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JH
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...RYAN/50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1110 AM CST FRI FEB 27 2015
.UPDATE...
ISSUED AT 721 AM CST FRI FEB 27 2015
RECORD LOW COLD TEMPERATURES OCCURRED TONIGHT WITH THE CLEAR SKIES
AND FRESH SNOWFALL. WIND CHILLS IN A FEW LOCATIONS WERE BELOW -30.
THE ONLY CHANGE TO THE FORECAST WERE THE TEMP TRENDS. EXPECT A
WARM UP ONCE THE SUN STARTS HEATING AS IT IS STARTING TO BECOME THE
SEASON OF HIGHER SUN ANGLES. WIND CHILL ADVISORY SHOULD STILL BE
OKAY THROUGH 9AM...A FEW SITES MAY LINGER WITH SUB -20 WIND CHILLS
THROUGH 10AM.
&&
.SYNOPSIS...
ISSUED AT 307 AM CST FRI FEB 27 2015
HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS
MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE
PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS
OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD
WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30
BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND
TEMPERATURES SHOULD DROP MORE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI FEB 27 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY
AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH
SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS.
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS
BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG
TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER
COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY
AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I
LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE
ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT
WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND
CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY
FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE
TO ISSUE THIS AS THERE IS ALREADY ONE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI FEB 27 2015
TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH
CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE
RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE
IMPACTS.
TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST
SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL
LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S
SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE
MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE
NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH
DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE
SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL
CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS.
THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE
12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH
SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO
3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3
TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR
PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST
LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT
CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE
ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION
FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN
MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE
NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF
ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z
SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH.
MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP
WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY
LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH
RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF
THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN
CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN
GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF
AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT
AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT
IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN
AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY
NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN
TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE
LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A
HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS.
FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW
DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1109 AM CST FRI FEB 27 2015
VFR CONDITIONS WILL BE SEEN THROUGH 18Z/28 AS ARCTIC HIGH PRESSURE
MOVES INTO THE OHIO VALLEY.
&&
.CLIMATE...
ISSUED AT 307 AM CST FRI FEB 27 2015
COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY
AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT.
RECORD LOWS FOR FEBRUARY 28...
MOLINE.........-9 IN 1962
CEDAR RAPIDS...-17 IN 1962
DUBUQUE........-10 IN 1962
BURLINGTON.....-7 IN 1962
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...08
CLIMATE...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
725 AM CST FRI FEB 27 2015
.UPDATE...
ISSUED AT 721 AM CST FRI FEB 27 2015
RECORD LOW COLD TEMPERATURES OCCURRED TONIGHT WITH THE CLEAR SKIES
AND FRESH SNOWFALL. WIND CHILLS IN A FEW LOCATIONS WERE BELOW -30.
THE ONLY CHANGE TO THE FORECAST WERE THE TEMP TRENDS. EXPECT A
WARM UP ONCE THE SUN STARTS HEATING AS IT IS STARTING TO BECOME THE
SEASON OF HIGHER SUN ANGLES. WIND CHILL ADVISORY SHOULD STILL BE
OKAY THROUGH 9AM...A FEW SITES MAY LINGER WITH SUB -20 WIND CHILLS
THROUGH 10AM.
&&
.SYNOPSIS...
ISSUED AT 307 AM CST FRI FEB 27 2015
HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS
MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE
PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS
OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD
WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30
BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND
TEMPERATURES SHOULD DROP MORE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI FEB 27 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY
AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH
SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS.
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS
BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG
TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER
COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY
AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I
LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE
ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT
WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND
CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY
FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE
TO ISSUE THIS AS THERE IS ALREADY ONE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI FEB 27 2015
TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH
CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE
RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE
IMPACTS.
TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST
SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL
LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S
SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE
MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE
NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH
DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE
SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL
CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS.
THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE
12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH
SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO
3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3
TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR
PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST
LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT
CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE
ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION
FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN
MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE
NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF
ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z
SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH.
MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP
WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY
LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH
RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF
THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN
CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN
GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF
AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT
AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT
IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN
AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY
NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN
TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE
LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A
HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS.
FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW
DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 544 AM CST FRI FEB 27 2015
VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT WINDS AS HIGH
PRESSURE SETTLES OVER THE AREA. WINDS SHOULD FAVOR W TO NW TODAY
AND THEN FAVOR S TO SE OVERNIGHT. OVERALL WINDS WILL BE VERY
LIGHT. ONLY CONCERN WOULD BE FRIGID TEMPERATURES TODAY AND
TONIGHT.
&&
.CLIMATE...
ISSUED AT 307 AM CST FRI FEB 27 2015
COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY
AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT.
RECORD LOWS FOR FEBRUARY 28...
MOLINE.........-9 IN 1962
CEDAR RAPIDS...-17 IN 1962
DUBUQUE........-10 IN 1962
BURLINGTON.....-7 IN 1962
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
547 AM CST FRI FEB 27 2015
.SYNOPSIS...
ISSUED AT 307 AM CST FRI FEB 27 2015
HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS
MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE
PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS
OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD
WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30
BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND
TEMPERATURES SHOULD DROP MORE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI FEB 27 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY
AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH
SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS.
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS
BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG
TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER
COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY
AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I
LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE
ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT
WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND
CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY
FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE
TO ISSUE THIS AS THERE IS ALREADY ONE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI FEB 27 2015
TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH
CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE
RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE
IMPACTS.
TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST
SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL
LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S
SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE
MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE
NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH
DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE
SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL
CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS.
THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE
12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH
SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO
3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3
TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR
PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST
LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT
CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE
ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION
FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN
MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE
NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF
ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z
SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH.
MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP
WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY
LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH
RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF
THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN
CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN
GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF
AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT
AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT
IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN
AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY
NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN
TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE
LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A
HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS.
FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW
DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 544 AM CST FRI FEB 27 2015
VFR CONDITIONS THROUGH THE PERIOD WITH LIGHT WINDS AS HIGH
PRESSURE SETTLES OVER THE AREA. WINDS SHOULD FAVOR W TO NW TODAY
AND THEN FAVOR S TO SE OVERNIGHT. OVERALL WINDS WILL BE VERY
LIGHT. ONLY CONCERN WOULD BE FRIGID TEMPERATURES TODAY AND
TONIGHT.
&&
.CLIMATE...
ISSUED AT 307 AM CST FRI FEB 27 2015
COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY
AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT.
RECORD LOWS FOR FEBRUARY 28...
MOLINE.........-9 IN 1962
CEDAR RAPIDS...-17 IN 1962
DUBUQUE........-10 IN 1962
BURLINGTON.....-7 IN 1962
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
307 AM CST FRI FEB 27 2015
.SYNOPSIS...
ISSUED AT 307 AM CST FRI FEB 27 2015
HIGH PRESSURE WAS MOVING INTO THE CENTRAL PLAINS EARLY THIS
MORNING. WITH FRESH SNOWFALL AND CLEAR SKIES TEMPERATURES HAVE
PLUMMETED THIS MORNING TO QUITE POSSIBLY ONE OF THE COLDEST NIGHTS
OF THE YEAR. WINDS HAVE STAYED UP...WHICH HAS LEAD TO WIDESPREAD
WIND CHILLS BETWEEN 20 AND 30 BELOW ZERO WITH A FEW POCKETS OF 30
BELOW OR LOWER WIND CHILLS. WINDS ARE STARTING TO WANE AND
TEMPERATURES SHOULD DROP MORE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI FEB 27 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE TEMPERATURES TODAY
AND TONIGHT ACROSS THE AREA. WITH HIGH PRESSURE IN PLACE AND FRESH
SNOW COVER...GUIDANCE IS OF LITTLE HELP FOR TEMPERATURE FORECASTS.
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED...H5 RIDGING IS
BUILDING INTO THE CENTRAL UNITED STATES AS A SURFACE HIGH IS PROG
TO MOVE DIRECTLY OVER OUR CWA TODAY. WINDS SHOULD WANE...HOWEVER
COLD AIR AND FRESH SNOWFALL WILL LEAD TO COLD TEMPERATURES TODAY
AND TONIGHT. MODELS ARE OF LITTLE HELP...THIS MORNING FOR LOWS I
LOADED THE OBS AND THEN MADE TWEAKS FROM THERE AS THE RUC WAS THE
ONLY MODEL COLD ENOUGH WITH TEMPS. FOR TODAY AND TONIGHT...WENT
WITH THE ALLBLEND AND THEN TWEAKED TEMPERATURES FROM THERE. WIND
CHILLS TONIGHT SUGGEST THE NEED FOR ANOTHER WIND CHILL ADVISORY
FOR AREAS NORTH OF I80. WILL DEFER TO THE DAY TO SHIFT TO DECIDE
TO ISSUE THIS AS THERE IS ALREADY ONE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI FEB 27 2015
TWO STORM SYSTEMS WILL IMPACT THE EXTENDED FORECAST...AND BOTH
CONTAIN POTENTIAL WINTER IMPACTS. AT THIS TIME...BOTH SYSTEMS ARE
RELATIVELY POOR IN CONFIDENCE OF EXACT DETAILS CONCERNING THESE
IMPACTS.
TO BEGIN THE EXTENDED...HIGH PRESSURE WILL BE MOVING OFF TO THE EAST
SATURDAY...AND WITH A VERY COLD START TO THE DAY...THE WEAK WAA WILL
LIKELY ONLY RESULT IN HIGHS IN THE MID TEENS NORTH TO MID 20S
SOUTH...DESPITE A HEALTHY AMOUNT OF LATE FEBRUARY SUNSHINE IN THE
MORNING. WARM ADVECTION BY AFTERNOON...WILL BRING MID LEVEL MOISTURE
NORTHWARD...WITH SOME MODELS CONTINUING TO BRUSH OUR SOUTHWEST WITH
DEEPER SATURATION BY LATE AFTERNOON. THE MODEL BLEND SHOWS FAR MORE
SIGNIFICANT MOISTURE ADVECTION BY SATURDAY NIGHT...AND I WILL
CONTINUE TO HIGHLIGHT THAT PERIOD THROUGH SUNDAY WITH HIGH POPS.
THIS EVENT IS GOING TO BE ALL SNOW...AND SHOULD HAVE RATIOS IN THE
12 TO 15 TO 1 RANGE...THUS AMOUNTS FROM SATURDAY EVENING THROUGH
SUNDAY AFTERNOON SHOULD RANGE FROM AROUND 1 INCH NORTHWEST...TO 2 TO
3 INCHES FROM IOWA CITY THROUGH THE QUAD CITIES TO STERLING...TO 3
TO 5 INCHES OVER FAR SOUTHEAST IOWA NORTHEAST MISSOURI TO NEAR
PRINCETON ILLINOIS. WHILE THOSE AMOUNTS ARE SUPPORTED BY THE MOST
LIKELY BLEND OF GUIDANCE THAT IS INDICATED AT THIS TIME...I AM NOT
CONFIDENT IN THEM YET. THE EVENT IS LIKELY GOING TO FALL INTO THE
ADVISORY RANGE...ESPECIALLY DUE TO THE LONGER THAN NORMAL DURATION
FOR THESE RANGE OF AMOUNTS. LOOKING AT UNCERTAINTY...THE CANADIAN
MODEL IS FARTHER SOUTH THAN THE ECMWF AND GFS...AND KEEPS THE
NORTHERN 3/4S OF THE CWA DRY...THUS ANOTHER REASON FOR HOLDING OFF
ON ANY EARLY HEADLINE AT THIS TIME. THE 06Z NAM...THROUGH 12Z
SUNDAY...ALSO KEEPS THE BULK OF MOISTURE AND FORCING SOUTH.
MONDAY WILL BE A BREAK BETWEEN LOW CONFIDENCE SYSTEM...AS THE DEEP
WESTERN TROF BECOMES EVEN MORE AMPLIFIED. THE MODELS HAVE SHOWN VERY
LITTLE CONSISTENCY OVER THE PAST FEW DAYS AND THROUGH TONIGHT WITH
RESPECT TO THE LOW TRACK...UPPER ENERGY TRACK...AND BAROCLINICITY OF
THIS POTENTIAL SYSTEM. ONE FEATURE THAT HAS BEEN SHOWN
CONSISTENTLY...HAS BEEN MOISTURE...WITH A SYNOPTIC SIGNAL OF AN OPEN
GULF OF MEXICO...AND EVEN OPEN CARIBBEAN. THE HIGH AMOUNTS OF
AVAILABLE MOISTURE ARE REASONS SUPPORTING LIKELY POPS MONDAY NIGHT
AND TUESDAY. WHILE NOT CONFIDENT IN THERMAL TRANSITION TIMING...IT
IS A BEST MODEL BLEND...AND CONCEPTUAL MODEL FIT FOR PCPN TO BEGIN
AS A WINTRY MIX OF SNOW/SLEET/FREEZING RAIN MONDAY
NIGHT...TRANSITIONING TO RAIN TUESDAY...THEN BACK TO SNOW AGAIN
TUESDAY NIGHT. THIS WET MESS COULD BE HIGH IMPACT...OR COULD BE
LARGELY BENIGN. IT IS VERY DIFFICULT TO TELL...AND WILL KEEP A
HEALTHY DOSE OF UNCERTAINTY IN OUR PRODUCTS.
FOLLOWING THIS SYSTEM...COLDER DRY WEATHER SETTLES BACK IN THE A FEW
DAYS BEFORE MODERATION LOOKS TO OCCUR IN ZONAL FLOW.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1134 PM CST THU FEB 26 2015
CLEAR SKIES AND LIGHT NORTHWEST TO WEST WINDS WILL CONTINUE
OVERNIGHT THROUGH FRIDAY KEEPING VFR CONDITIONS IN PLACE. ARCTIC
HIGH PRESSURE MOVING THROUGH THE REGION WILL RESULT IN BITTER COLD
TEMPERATURES.
&&
.CLIMATE...
ISSUED AT 307 AM CST FRI FEB 27 2015
COULD SEE RECORD LOWS THIS MORNING AT A FEW SITES AND POSSIBLY
AGAIN TONIGHT AT OTHER SITES. HERE ARE THE RECORDS FOR TONIGHT.
RECORD LOWS FOR FEBRUARY 28...
MOLINE.........-9 IN 1962
CEDAR RAPIDS...-17 IN 1962
DUBUQUE........-10 IN 1962
BURLINGTON.....-7 IN 1962
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BENTON-
BUCHANAN-CEDAR-CLINTON-DELAWARE-DES MOINES-DUBUQUE-HENRY IA-
IOWA-JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LEE-LINN-LOUISA-
MUSCATINE-SCOTT-VAN BUREN-WASHINGTON.
IL...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR BUREAU-
CARROLL-HANCOCK-HENDERSON-HENRY IL-JO DAVIESS-MCDONOUGH-
MERCER-PUTNAM-ROCK ISLAND-STEPHENSON-WARREN-WHITESIDE.
MO...WIND CHILL ADVISORY UNTIL 9 AM CST THIS MORNING FOR CLARK-
SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...SHEETS
CLIMATE...GIBBS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
558 PM CST SAT FEB 28 2015
...UPDATE TO AVIATION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CST SAT FEB 28 2015
AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE
WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS
ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR
LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE
LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE
SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS
WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A
CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z
RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN
THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT
PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY
THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS
THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A
FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN
THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE
SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT
THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET
AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE
ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION
TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE
INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER
WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE
MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY
AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 555 PM CST SAT FEB 28 2015
MVFR CIGS WILL PREVAIL AT ALL TAF SITES THROUGH MID EVENING AS
LOW LEVEL STRATUS PERSISTS ACROSS CENTRAL AND SOUTHWEST KANSAS.
THE STRATUS IS EXPECTED TO LOWER SOMEWHAT LATE TONIGHT AS ANOTHER
ROUND OF SNOW, POSSIBLY MIXED WITH SLEET EAST OF KGCK, DEVELOPS
OVERNIGHT ACROSS PORTIONS OF SOUTHWEST AND CENTRAL KANSAS. AS A
RESULT, IFR CIGS/VSBYS WILL BE POSSIBLE IN THE VICINITY OF KGCK
AND KDDC GENERALLY AFTER 03Z. KHYS COULD SEE IFR CIGS TOWARD
DAYBREAK SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 31 20 38 / 70 60 20 20
GCK 17 31 19 40 / 60 30 20 20
EHA 21 33 21 45 / 30 20 30 20
LBL 21 34 22 43 / 50 30 20 10
HYS 14 35 21 39 / 40 30 20 20
P28 20 32 22 39 / 60 60 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST SUNDAY FOR KSZ046-064>066-
076>081-086>090.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...JJOHNSON
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1036 AM MST FRI FEB 27 2015
.UPDATE...
ISSUED AT 842 AM MST FRI FEB 27 2015
UPDATED THE FORECASTS TO REMOVE THE WIND CHILL ADVISORY ACROSS KIT
CARSON AND CHEYENNE COUNTIES AS WIND CHILL READINGS WILL GRADUALLY
RISE THE REST OF TODAY. OTHERWISE...LIGHT SNOW CONTINUES OVER THE
AREA. 12Z NAM SHOWS SNOW WILL DECREASE FROM NORTH TO SOUTH AFTER
18Z...THEN NEXT SHORT WAVE TROUGH WILL MOVE ACROSS SOUTHWEST
KANSAS TONIGHT BRINGING ANOTHER GOOD CHANCE OF SNOW...ESPECIALLY
SOUTH OF INTERSTATE 70.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH
MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS
AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS
CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA
STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A
TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F).
REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY
TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME
PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN
THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD
SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS
TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND
CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON
TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS
TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS
MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL
CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE
AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER
TO LET THE CURRENT ONE PLAY OUT.
TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND
PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS
APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE
SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE
REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF
THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH
ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE
TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS
WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING
AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF
ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF
I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW
DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO
ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT
PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR
ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED.
TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER
THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD
AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING
TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW.
GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST
OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT
ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR
EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON
THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT.
CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS
LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN
THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST
PRECIP SIGNAL.
REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL
TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT
SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS
OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE
POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME
TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT
CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST.
.LONG TERM...(MONDAY THROUGH THURSDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE
FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES
SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF
PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE
ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND
HAVE DRY CONDITIONS AFTER THAT.
THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER
SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES
AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY
TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE
BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH
THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA
INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST
OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH
NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE
HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT.
A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE
TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER
TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION
SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY
MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER
TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE
COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH
PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE
RIDGE ALOFT BUILDS IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1032 AM MST FRI FEB 27 2015
LIGHT SNOW CONTINUES AT KGLD...AND RADAR IMAGERY INDICATES THE
SNOW WILL CONTINUE A FEW MORE HOURS. VFR CONDITIONS ARE REPORTED
AT KMCK...BUT LIGHT SNOW IS JUST TO THE WEST. BASED ON SHORT
RANGE MODELS...ENDED THE SNOW AT KGLD/KMCK AFTER 21Z. SNOW WILL
REDEVELOP AFTER 09Z WHEN THE NEXT SHORTWAVE TROUGH MOVES ACROSS
THE AREA. FOR THE NEXT 12 HOURS...CONDITIONS WILL BE MOSTLY MVFR
DUE CEILINGS AND PERIODS OF LIGHT SNOW...THEN DROPPING TO IFR
LATER TONIGHT DUE TO A BETTER CHANCE OF SNOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MENTZER
SHORT TERM...DR
LONG TERM...99
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
842 AM MST FRI FEB 27 2015
.UPDATE...
ISSUED AT 842 AM MST FRI FEB 27 2015
UPDATED THE FORECASTS TO REMOVE THE WIND CHILL ADVISORY ACROSS KIT
CARSON AND CHEYENNE COUNTIES AS WIND CHILL READINGS WILL GRADUALLY
RISE THE REST OF TODAY. OTHERWISE...LIGHT SNOW CONTINUES OVER THE
AREA. 12Z NAM SHOWS SNOW WILL DECREASE FROM NORTH TO SOUTH AFTER
18Z...THEN NEXT SHORT WAVE TROUGH WILL MOVE ACROSS SOUTHWEST
KANSAS TONIGHT BRINGING ANOTHER GOOD CHANCE OF SNOW...ESPECIALLY
SOUTH OF INTERSTATE 70.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH
MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS
AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS
CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA
STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A
TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F).
REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY
TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME
PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN
THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD
SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS
TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND
CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON
TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS
TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS
MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL
CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE
AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER
TO LET THE CURRENT ONE PLAY OUT.
TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND
PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS
APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE
SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE
REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF
THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH
ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE
TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS
WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING
AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF
ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF
I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW
DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO
ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT
PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR
ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED.
TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER
THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD
AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING
TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW.
GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST
OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT
ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR
EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON
THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT.
CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS
LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN
THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST
PRECIP SIGNAL.
REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL
TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT
SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS
OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE
POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME
TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT
CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST.
.LONG TERM...(MONDAY THROUGH THURSDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE
FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES
SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF
PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE
ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND
HAVE DRY CONDITIONS AFTER THAT.
THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER
SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES
AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY
TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE
BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH
THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA
INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST
OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH
NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE
HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT.
A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE
TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER
TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION
SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY
MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER
TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE
COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH
PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE
RIDGE ALOFT BUILDS IN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 428 AM MST FRI FEB 27 2015
LIGHT SNOW IS CONTINUING TO IMPACT THE KGLD TERMINAL WITH IFR VIS
AND MVFR CIGS. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAYTIME
PERIOD AT KMCK. CONDITIONS COULD VARY THIS MORNING AT KGLD THOUGH
IMPROVEMENT ABOVE IFR ISNT LIKELY UNTIL LATER THIS MORNING AS LONG
AS LIGHT SNOW LINGERS. AS WINDS INCREASE DURING THE DAY BLOWING
SNOW MAY BE POSSIBLE...HOWEVER CONFIDENCE IN REDUCED VIS DUE TO
THIS IS TOO LOW TO ADD MENTION DURING THIS UPDATE. MVFR CIGS
SHOULD CONTINUE THIS AFTERNOON/EVENING AT KGLD BASED ON TRENDS IN
GUIDANCE...THOUGH THERE COULD BE BREAKS IN STRATUS ALLOWING FOR
BRIEF PERIODS OF VFR CONDITIONS. LOW LEVEL MOISTURE RETURN WILL
RESULT IN IFR CIGS DEVELOPING LATE TONIGHT AND MVFR DEVELOPING AT
KMCK LATE TONIGHT. WINDS SHOULD LIMIT LOW LEVEL
SATURATION...HOWEVER ADVECTION FOG CANNOT BE COMPLETELY RULE OUT.
LIGHT SNOW MAY ALSO REDEVELOP...THOUGH BETTER CHANCE APPEAR TO
REMAIN SOUTH AND EAST OF BOTH KGLD AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...MENTZER
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
428 AM MST FRI FEB 27 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH
MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS
AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS
CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA
STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A
TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F).
REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY
TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME
PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN
THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD
SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS
TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND
CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON
TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS
TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS
MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL
CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE
AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER
TO LET THE CURRENT ONE PLAY OUT.
TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND
PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS
APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE
SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE
REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF
THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH
ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE
TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS
WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING
AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF
ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF
I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW
DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO
ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT
PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR
ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED.
TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER
THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD
AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING
TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW.
GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST
OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT
ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR
EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON
THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT.
CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS
LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN
THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST
PRECIP SIGNAL.
REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL
TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT
SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS
OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE
POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME
TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT
CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST.
.LONG TERM...(MONDAY THROUGH THURSDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE
FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES
SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF
PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE
ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND
HAVE DRY CONDITIONS AFTER THAT.
THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER
SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES
AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY
TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE
BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH
THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA
INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST
OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH
NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE
HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT.
A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE
TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER
TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION
SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY
MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER
TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE
COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH
PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE
RIDGE ALOFT BUILDS IN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 428 AM MST FRI FEB 27 2015
LIGHT SNOW IS CONTINUING TO IMPACT THE KGLD TERMINAL WITH IFR VIS
AND MVFR CIGS. VFR CONDITIONS SHOULD CONTINUE THROUGH THE DAYTIME
PERIOD AT KMCK. CONDITIONS COULD VARY THIS MORNING AT KGLD THOUGH
IMPROVEMENT ABOVE IFR ISNT LIKELY UNTIL LATER THIS MORNING AS LONG
AS LIGHT SNOW LINGERS. AS WINDS INCREASE DURING THE DAY BLOWING
SNOW MAY BE POSSIBLE...HOWEVER CONFIDENCE IN REDUCED VIS DUE TO
THIS IS TOO LOW TO ADD MENTION DURING THIS UPDATE. MVFR CIGS
SHOULD CONTINUE THIS AFTERNOON/EVENING AT KGLD BASED ON TRENDS IN
GUIDANCE...THOUGH THERE COULD BE BREAKS IN STRATUS ALLOWING FOR
BRIEF PERIODS OF VFR CONDITIONS. LOW LEVEL MOISTURE RETURN WILL
RESULT IN IFR CIGS DEVELOPING LATE TONIGHT AND MVFR DEVELOPING AT
KMCK LATE TONIGHT. WINDS SHOULD LIMIT LOW LEVEL
SATURATION...HOWEVER ADVECTION FOG CANNOT BE COMPLETELY RULE OUT.
LIGHT SNOW MAY ALSO REDEVELOP...THOUGH BETTER CHANCE APPEAR TO
REMAIN SOUTH AND EAST OF BOTH KGLD AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...WIND CHILL ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
323 AM MST FRI FEB 27 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW SHORTWAVE TROUGH
MOVING INTO NEBRASKA. MOISTURE PLUME EXTENDS ACROSS WESTERN KANSAS
AND EASTERN COLORADO. AT THE SURFACE 1038 MB HIGH PRESSURE IS
CENTERED OVER THE MISSOURI RIVER VALLEY NEAR THE NEBRASKA AND IOWA
STATE LINE. SOUTHEASTERLY FLOW IS IN PLACE ACROSS THE CWA WITH A
TIGHT TD GRADIENT FROM THE WEST (AROUND 10F) TO THE NORTHEAST (-2F).
REGARDING WIND CHILL ADVISORY THIS MORNING AND THE POSSIBILITY
TONIGHT...WINDS ARE STILL EXPECTED TO INCREASE IN THE 12-15Z TIME
PERIOD THIS MORNING. BASED ON CURRENT WIND FORECAST...IF TEMPS IN
THE ADVISED AREA WERE TO DROP TO AROUND 4F OR LOWER WINDS WOULD
SUPPORT -15F WIND CHILLS. SHORT RANGE GUIDANCE GENERALLY KEEPS
TEMPS STEADY IN THE WEST WHERE THE HIGHER WINDS WILL BE AND WIND
CHILLS IN THE -10F OR WARMER RANGE. AT THIS POINT I SEE NO REASON
TO CHANGE ADVISORY CONSIDERING HOW CLOSE IT WILL BE. CONDITIONS
TONIGHT/EARLY SATURDAY MORNING COULD BE SIMILAR AS THIS
MORNING...WITH CLOUD COVER THE LIMITING FACTOR ON IDEAL RADIATIONAL
CONDITIONS. IT COULD BE CLOSE TO ADVISORY CRITERIA...BUT WITH THE
AMOUNT OF UNCERTAINTY AND ONGOING ADVISORY THIS MORNING I PREFER
TO LET THE CURRENT ONE PLAY OUT.
TODAY...LIGHT SNOW HAS BEEN REPORTED ACROSS EASTERN COLORADO AND
PARTS OF NW KANSAS EARLY THIS MORNING...WITH LIGHT ACCUMULATIONS
APPARENT ON WEB CAMS AND OBSERVED AT WFO. SHORT RANGE GUIDANCE
SHOWS THIS ACTIVITY CONTINUING TO TRANSITION SOUTHEAST ACROSS THE
REGION AS SHORTWAVE SLIDES EAST. CONSIDERING THE LIGHT NATURE OF
THE RADAR RETURNS ACROSS THE CWA IT IS HARD TO JUDGE HOW MUCH
ACCUMULATION IS ACTUALLY OCCURRING AND TREND IN GUIDANCE HAS BE
TOWARDS LOWER VALUES. MAIN THREAT FOR MEANINGFUL ACCUMULATIONS
WILL BE BEFORE 18Z...WITH CHANCE FOR MEASURABLE SNOW DIMINISHING
AFTERWARDS. IT APPEARS 1-2" SHOULD STILL BE THE HIGH END OF
ACCUMULATION FROM NOW THROUGH MIDDAY (MAINLY ALONG AND SOUTH OF
I-70). AS WINDS INCREASE WE COULD STILL SEE BLOWING SNOW
DEVELOP...HOWEVER THIS SHOULD BE AN ISOLATED THREAT AND TIED TO
ANY NEW SNOWFALL RATHER THAN OLD/CRUSTED OVER SNOW PACK. I KEPT
PATCHY BLOWING SNOW MENTION AND DO NOT THINK THERE IS A NEED FOR
ADVISORY AS VIS RESTRICTIONS FROM BLOWING SNOW WILL BE ISOLATED.
TONIGHT-SUNDAY NIGHT...H3 JET BEGINS TO TRANSITION NORTHWARD OVER
THE CWA AS TROUGH DEEPENS ACROSS THE SW US. RESULT WITH BE BROAD
AREA OF WEAK FORCING DEVELOPING ACROSS THE CWA...WITH BETTER FORCING
TIED TO MID LEVEL CIRCULATIONS ROTATING THROUGH THE MEAN FLOW.
GUIDANCE HAS TRENDED TOWARDS BETTER PRECIP SIGNALS EITHER WELL WEST
OF THE CWA...OR SOUTHEAST OF THE CWA. WE COULD STILL SEE LIGHT
ACCUMULATIONS...HOWEVER BEST CHANCE SEEMS TO BE IN OUR
EASTERN/SOUTHEAST CWA AND AMOUNTS HAVE TRENDED LOWER WITH 1-2" ON
THE HIGHER END OF TOTAL ACCUMULATIONS SATURDAY/SATURDAY NIGHT.
CONSIDERING THE TRENDS AND AMOUNT OF UNCERTAINTY I TRENDED POPS
LOWER THROUGH ALL THESE PERIODS AND ADJUSTED HIGHEST POPS TO BE IN
THE EASTERN CWA SATURDAY AFTERNOON/EVENING CORRELATING WITH BEST
PRECIP SIGNAL.
REGARDING TEMPS...AS HAS BEEN THE CASE WE SHOULD SEE BELOW NORMAL
TEMPERATURES CONTINUE WITH ONLY SLOW MODERATION TO TEMPS ALOFT
SATURDAY/SUNDAY AS SW FLOW ALOFT DEVELOPS ACROSS THE SOUTHERN PLANS
OVER THE TOP OF THE PERSISTENT ARCTIC AIR MASS. CLOUD COVER AND THE
POSSIBILITY OF PRECIP CONTINUES TO COMPLICATE DAYTIME/NIGHTTIME
TEMPS...SO ONLY MADE MINOR ADJUSTMENTS TO REFLECT CURRENT
CONSENSUS/MODEL TRENDS. LITTLE CHANGE FROM PREVIOUS FORECAST.
.LONG TERM...(MONDAY THROUGH THURSDAY NIGHT)
ISSUED AT 323 AM MST FRI FEB 27 2015
MODELS HAVE THE JET POSITIONED SLIGHTLY FURTHER NORTH DURING THE
FIRST PART OF NEXT WEEK WHICH MAY END UP KEEPING TEMPERATURES
SLIGHTLY WARMER AND WILL LIKELY ALSO MOVE THE JET ENHANCED AREA OF
PRECIPITATION FURTHER NORTH ACROSS THE FORECAST AREA. MODELS ARE
ENDING PRECIPITATION ACROSS THE FORECAST AREA WEDNESDAY MORNING AND
HAVE DRY CONDITIONS AFTER THAT.
THE UPPER LOW CENTER THAT STARTS OUT AS A CLOSED LOW OVER OVER
SOUTHERN CALIFORNIA ON SUNDAY EJECTS OUT ACROSS THE SOUTHERN ROCKIES
AND CENTRAL HIGH PLAINS REGION AS AN OPEN WAVE ON MONDAY NIGHT/EARLY
TUESDAY. THIS IS AHEAD OF A SHORT WAVE TROUGH DROPPING INTO THE
BASE OF THE MAIN TROUGH AXIS OVER BAJA AND ANOTHER LOW IN PHASE WITH
THE MAIN UPPER TROUGH THAT BEGINS MOVING FROM SOUTH CENTRAL CANADA
INTO THE NORTHERN PLAINS. THE ENTIRE MAJOR TROUGH AXIS SWEEPS EAST
OF THE ROCKIES AND ACROSS THE PLAINS WEDNESDAY EVENING WITH
NORTHWEST FLOW AND RIDGING TO EXTEND ACROSS THE ROCKIES INTO THE
HIGH PLAINS REGION BY THURSDAY AND THURSDAY NIGHT.
A SURFACE LOW AND COLD FRONT ASSOCIATED WITH THE UPPER SHORT WAVE
TROUGH LIFTING ACROSS THE REGION ON TUESDAY USHERS IN COOLER
TEMPERATURES ACROSS FORECAST AREA AND SPREADS THE PRECIPITATION
SOUTHWARD ACROSS THE FORECAST AREA TUESDAY NIGHT AND WEDNESDAY
MORNING. SNOW WILL COME TO AN END ON WEDNESDAY WITH MUCH COLDER
TEMPERATURES AS SURFACE HIGH PRESSURE MOVES INTO THE REGION. THE
COLD AIR SHOULD NOT LAST LONG AS RETURN FLOW AROUND THE EXITING HIGH
PRESSURE AREA TURNS SOUTHWESTERLY ACROSS THE FORECAST AREA AND THE
RIDGE ALOFT BUILDS IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 958 PM MST THU FEB 26 2015
LATEST RADAR TRENDS INDICATE THAT VFR CONDITIONS SHOULD
DETERIORATE TO MVFR AT KGLD OVERNIGHT WITH LIGHT SNOW DEVELOPING.
MODELS INDICATE THE SNOW SHOULD TAPER OFF BY MIDDAY BUT MVFR WILL
PERSIST. VFR CONDITIONS WILL CONTINUE AT KMCK FOR MOST OF THE
NEXT 24 HOURS. HOWEVER, THE FORECAST SOUNDING FOR KMCK SHOWS SOME
STRATUS DEVELOPING AND PERSISTING INTO FRIDAY EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...WIND CHILL ADVISORY UNTIL 11 AM MST THIS MORNING FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...99
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
958 PM EST SAT FEB 28 2015
.UPDATE...
ISSUED AT 958 PM EST SAT FEB 28 2015
MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE
ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS.
DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE
SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE
QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO
PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE
A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS
BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT
THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER
WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING
RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND
TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER
TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE
FORECAST AS IS.
UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015
OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING
RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE
HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z
TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY
ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING
RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY
ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS
THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND
DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE
EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A
TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD
AIR GETS SCOURED OUT IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SAT FEB 28 2015
WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING
HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL
BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL
THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL
KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP
INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE
CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT
ICE AND SNOW POTENTIAL.
LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR
GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS...
CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE
ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS
SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3
HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING
BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY
A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL
JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN
A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST
SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM
ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO
15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY
INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE
AFTERNOON...GENERALLY IN THE 40S.
FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE
CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY
NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL
THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER
DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY
MORNING AS HIGH PRESSURE MOVES IN OVERHEAD.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 451 PM EST SAT FEB 28 2015
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A
POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST
FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW
FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND
TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH
WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE
FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING
PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD
AND DRY.
DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER
CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE
STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS
SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY
FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT
RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH
THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS
WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC
OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY
TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS
WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD
THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON
TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL
FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE
HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING
HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK
INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR
THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S
FOR SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 715 PM EST SAT FEB 28 2015
VFR CONDITIONS WILL LAST INTO THE NIGHT. HOWEVER...AS THE LOW
LEVEL JET STRENGTHENS OVERNIGHT...BETTER MOISTURE WILL BE
TRANSPORTED INTO EASTERN KENTUCKY WITH CIG HEIGHTS LOWERING LATE
TONIGHT. SOME MVFR CIGS ARE POSSIBLE BY DAYBREAK. IN
ADDITION...SOME SLEET/FREEZING RAIN WILL ALSO BE POSSIBLE AROUND
DAYBREAK...BEFORE TRANSITIONING TO ALL RAIN BY MID MORNING.
CONFIDENCE ON FORECAST TOMORROW IS NOT HIGH AND THUS...CIG
FORECAST REMAINS VERY UNCERTAIN. ITS POSSIBLE SOME MVFR CIGS MAY
HOLD ON THROUGH THE DAY...BUT SOUTHERLY FLOW COULD ERODE THESE
AWAY THROUGH THE DAY WITH A SLIGHT DOWNSLOPING COMPONENT.
REGARDLESS...AT THE VERY LEAST...WE SHOULD SEE A MIX OF VFR/MVFR
CONDITIONS. SOME RAIN SHOWERS COULD ALSO PERSIST THROUGH THE DAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
341 AM EST FRI FEB 27 2015
.UPDATE...
ISSUED AT 103 AM EST FRI FEB 27 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE A WEAK ARCTIC
FRONT MOVING THROUGH THE AREA. ASSOCIATED WITH THE FRONT IS SOME
WEAK RETURNS SHOWING SOME FLURRIES AND SNOW SHOWERS. SOME OF THESE
SNOW SHOWERS HAVE PRODUCED A DUSTING AT MOST IN SOME AREAS WITH
SOME VISIBILITIES NEAR A MILE. THIS BAND HAS A FINE EDGE NOW
CROSSING I-64. THIS SHOULD BRING AN END TO THE ACTIVITY INTO THE
MORNING HOURS. HAVE SENT OUT SOME FRESHENED UP GRIDS TO ADDRESS
THIS AND TEMPERATURES AS THE COLDER AIR IS NOW PUSHING THROUGH THE
MIDWEST STATES AND NOW INTO KY. THOUGH NO SIGNIFICANT CHANGE WAS
MADE TO THE ZFP...THE GRIDS HAVE BEEN SENT TO THE NDFD SERVERS.
UPDATE ISSUED AT 945 PM EST THU FEB 26 2015
A DISTURBANCE IS WORKING THROUGH THE GREAT LAKES AND OH VALLEY
REGION AND IS BRINGING SOME VERY LIGHT SNOW OR FLURRIES TO THE
REGION. AWOS AND ASOS SITES OVER CENTRAL AND NORTHERN KY HAVE
REPORTED SNOW REACHING THE GROUND...BUT THE AIR MASS IS RATHER
DRY...SO VISIBILITIES AND CEILINGS HAVE NOT DROPPED ALL THAT FAR.
AT THIS POINT...PER RADAR AND SFC OBS IT APPEARS THAT THE LIGHT
SNOW OR FLURRIES IS NEARING THE SOMERSET TO JACKSON TO SANDY HOOK
LINE. ONLY ONE KY MESONET SITE IN CENTRAL KY HAS RECEIVED
MEASURABLE PRECIPITATION WITH THIS.
THE NEAR TERM MODELS SUCH AS THE HRRR CONTINUE TO HAVE THIS
DIMINISHING AS IT MOVES EAST...BUT IT SEEMS TO CLEARLY BE HOLDING
TOGETHER BETTER THAN THE HRRR IS FORECASTING. THE WINDS ARE BIT
MORE NORTHERLY THAN IDEAL FOR UPSLOPE ALTHOUGH THERE IS A BIT OF
AN UPSLOPE COMPONENT. THE CURRENT FORECAST IS MORE REFLECTIVE OF
THE MOST RECENT NAM AND GFS RUNS AS SEEMS MORE REASONABLE GIVEN
UPSTREAM TRENDS. AT THIS POINT...SLIGHT CHANCE TO CHANCE POPS
APPEAR TO REMAIN IN ORDER AND AN SPS IS ALREADY IN PLACE. SOME
LOCATIONS MAY PICK UP A QUARTER TO A HALF OF AN INCH OF FLUFF
WHILE OTHER LOCATIONS MAY ONLY GET A LIGHT DUSTING OR NOTHING AT
ALL. THE BIGGER STORY WILL BE THE COLDER AIR WORKING INTO THE
REGION LATE TONIGHT. LOWS SHOULD REACH THE UPPER SINGLE DIGITS
ABOVE ZERO NORTH...WITH UPPER TEENS NEAR THE TN BORDER. TEMPS WILL
STRUGGLE TO REACH THE MID TO UPPER 20S IN MANY LOCATIONS ON
FRIDAY...ALTHOUGH FRI NIGHT APPEARS TO BE COLDER ON AVERAGE THAN
TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 355 PM EST THU FEB 26 2015
19Z SFC ANALYSIS SHOWS LOW PRESSURE PASSING BY TO THE EAST WHILE A
DEEP LOW IS APPROACHING FROM THE NORTHWEST. AN ARCTIC COLD FRONT
FROM THIS IS MOVING INTO KENTUCKY AND THIS WILL SWEEP ACROSS
EASTERN KENTUCKY LATER THIS EVENING. ON REGIONAL RADAR...THE LIGHT
SNOW ASSOCIATED WITH THIS BOUNDARY IS STARTING TO SETTLE DEEPER
INTO THE STATE. EAST KENTUCKY SAW PARTLY SUNNY SKIES THIS
AFTERNOON WITH SOME LOW CLOUDS CLINGING TO OUR FAR EASTERN AREAS
WHILE HIGH CLOUDS PASSED THROUGH NORTHERN PARTS OF THE CWA. LOWER
CLOUDS ARE INBOUND FROM WESTERN AND CENTRAL KENTUCKY NOW...AHEAD
OF THAT FRONT. TEMPERATURES WERE ABLE TO SPIKE UP TO NEAR 40
DEGREES FOR MUCH OF THE AREA THIS AFTERNOON THANKS TO THE PARTIAL
SUNSHINE WHILE ONLY LOW 30S WERE ACHIEVED IN THE NORTHWEST.
DEWPOINTS REMAIN IN THE TEENS IN THE NORTHWEST WHILE LOWER AND
MIDDLE 20S ARE FOUND IN THE EAST. WINDS WERE GENERALLY FROM THE
NORTHWEST AT 5 TO 10 MPH WITH GUSTS TO 15 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS A WEAK WAVE PASSES TO
THE SOUTH OF THE AREA THIS EVENING FOLLOWED BY A STRONGER AND
LARGER TROUGH THAT SETTLES INTO THE OHIO VALLEY TONIGHT. THIS
TROUGH WILL BRING ITS CORE ENERGY ACROSS OHIO DURING THE DAY
FRIDAY BEFORE TAPERING OFF AMIDST REBOUNDING HEIGHTS OVER KENTUCKY
FRIDAY NIGHT. THE ECMWF IS A BIT QUICKER THAN THE OTHER MODELS
WITH THESE HEIGHT RISES AND MAY BE GETTING AHEAD OF ITSELF. GIVEN
THE GENERAL AGREEMENT...AT LEAST INTO FRIDAY EVENING...HAVE
FAVORED THE HIGHER RESOLUTION MODEL GUIDANCE FROM THE HRRR...
RAP13...AND NAM12 FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE CLOUDS ARRIVING ALONG WITH SNOW
SHOWERS THIS EVENING AND CONTINUING THROUGH THE NIGHT IN
ASSOCIATION WITH THE ARCTIC AIR POURING BACK INTO THIS PART OF THE
STATE. TEMPERATURES WILL FALL INTO THE TEENS IN MOST PLACES BY
DAWN THANKS TO THE CAA WITH SOME SINGLE DIGITS POSSIBLE NORTH OF
INTERSTATE 64. ANY LINGERING SNOW SHOWERS WILL COME TO AN END
FRIDAY MORNING IN FAR EASTERN PARTS OF THE AREA WITH SOME SUNSHINE
POSSIBLE BY AFTERNOON...BUT TEMPERATURES WILL STILL STRUGGLE TO
MAKE IT INTO THE LOWER 20S BY MIDDAY. THIS SETS THE STAGE FOR A
VERY CHILLY NIGHT WITH SINGLE DIGITS LIKELY ON TAP FOR THE VALLEYS
AND MORE OPEN AREAS...WHILE SOME LATE ARRIVING HIGH CLOUDS AND THE
INVERSION MAY SPARE THE RIDGES THE COLDEST OF THE AIR. CANNOT RULE
OUT SOME FLURRIES ARRIVING TOWARD DAWN SATURDAY AHEAD OF THE NEXT
SYSTEM...BUT HAVE LEFT THEM OUT FOR NOW.
AGAIN USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS
THROUGH THE DAY FRIDAY...WITH SOME TERRAIN BASED ADJUSTMENTS MADE
AT NIGHT. AFTER THAT...USED THE SUPERBLEND TO INITIATE THE GRIDS
INTO SATURDAY MORNING WITH MINOR CHANGES. AS FOR POPS...ENDED UP
ON THE HIGH SIDE...CLOSER TO THE MET...OF RATHER LOW MOS GUIDANCE
TONIGHT...THEN SIMILAR FOR THE REST OF THE SHORT TERM.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 340 AM EST FRI FEB 27 2015
A VERY PERIOD IN STORE IN THE EXTENDED. THE PERIOD WILL ACTUALLY
START OFF FAIRLY QUIET...AS A WARM FRONTAL BOUNDARY MEANDERS ABOUT
ALONG THE OHIO RIVER. SNOW SHOWERS WILL BEGIN TO MOVE INTO THE
AREA AS THE WARM FRONT SAGS SOUTH AND INTERACTS WITH BELOW
FREEZING AIR THAT WILL ALREADY BE IN PLACE. THE SNOW SHOWERS WILL
CHANGE TO RAIN SHOWERS AND QUICKLY OVERSPREAD THE AREA SUNDAY AND
SUNDAY NIGHT AS THE COLD FRONT MAKES ITS WAY ACROSS THE AREA AND
WARM AIR SURGES NORTH AHEAD OF THE BOUNDARY. THE RAIN COULD BE
HEAVY TIMES SUNDAY NIGHT AND MONDAY. ONCE THE INITIAL COLD FRONT
EXITS THE AREA LATE IN THE DAY ON MONDAY...A LULL IN THE
PRECIPITATION IS EXPECTED...AS A RIDGE OF HIGH PRESSURE IS PROGGED
TO SETTLE OVER THE AREA FOR ABOUT 10 HOURS. AFTER THIS SHORT
RESPITE...ANOTHER ROUND OF RAIN AND SNOW SHOWERS IS EXPECTED AS A
WARM FRONT MOVES ACROSS THE AREA FROM THE SOUTH. THE PRECIPITATION
SHOULD CHANGE OVER TO ALL RAIN BY MID MORNING ON TUESDAY...AS WARM
GULF AIR PUSHES BACK INTO THE AREA AND OVERRIDES THE WARM FRONT.
THE RAIN IS EXPECTED TO BECOME WIDESPREAD DURING THE AFTERNOON AND
HOURS ON TUESDAY AND THROUGHOUT THE OVERNIGHT...AS ANOTHER COLD
FRONT PUSHES SLOWLY ACROSS THE AREA. THIS ROUND OF MODERATE TO
HEAVY RAIN IS FORECAST TO PERSIST THROUGH EARLY WEDNESDAY EVENING
BEFORE FINALLY LETTING UP. THE RAIN COULD BE HEAVY AT
TIMES...CREATING THE POTENTIAL FOR LOCALIZED FLOODING. HYDRO
ISSUES WILL ALSO BE POSSIBLE SUNDAY AFTERNOON THROUGH SUNDAY
NIGHT...AS WIDESPREAD RAIN WILL MELT THE EXISTING SNOW
PACK...WHICH WILL CREATE A LARGE AMOUNT OF RUNOFF THAT WILL MAKE
ITS WAY INTO AREA CREEKS AND STREAMS. THIS ADDITIONAL WATER WILL
LIKELY LEAD TO SIGNIFICANT RISES ON AREA RIVERS AS WELL.
A ROUND OF SCATTERED SNOW SHOWERS IS THEN EXPECTED TO MOVE IN
BEHIND THE DEPARTING COLD FRONT LATE WEDNESDAY NIGHT AND THURSDAY
MORNING...AS COLDER AIR FILTERS IN FROM THE WEST AND NORTHWEST.
ONLY LIGHT ACCUMULATIONS ARE POSSIBLE. THE PRECIPITATION SHOULD
FINALLY COME TO AN END LATE THURSDAY NIGHT. THE GOOD NEWS IS THAT
THE LOW TEMPERATURES WE ARE EXPECTING NEXT WEEK WILL NOT BE
ANYWHERE NEAR AS COLD AS WHAT WE HAVE EXPERIENCED THAT PAST TWO
WEEKS. THE FIRST COUPLE OF DAYS OF THE EXTENDED ARE FORECAST TO
FEATURE ONLY SLIGHTLY BELOW NORMAL TEMPERATURES...WITH LOWS ON
SUNDAY MORNING BOTTOMING OUT IN THE MID TO UPPER 20S ACROSS THE
AREA. HIGHS ON SUNDAY SHOULD BE ABLE TO CLIMB WELL INTO THE 40S
ACROSS THE AREA AS SOUTHERLY FLOW BEGINS TO DOMINATE THE AREA. THE
WARM UP IS EXPECTED TO CONTINUE ON TUESDAY AND WEDNESDAY...WITH
THE MERCURY FORECAST TO TOP OUT IN THE MID TO UPPER 50S AROUND
EASTERN KENTUCKY. A FEW LOCATIONS IN OUR FAR SOUTHWEST MAY EVEN
REACH 60 DEGREES ON TUESDAY. THE PASSAGE OF A COLD FRONT WILL
BRING ANOTHER SHOT OF COLDER AIR INTO THE REGION BY MIDWEEK...WITH
HIGHS ON THURSDAY AND FRIDAY ONLY EXPECTED TO MAX OUT IN THE MID
TO UPPER 30S. AFTER LOWS IN THE 40S TUESDAY NIGHT...COLDER AIR
WILL FILTER INTO THE REGION FOR A FEW DAYS. LOW TEMPERATURES
THURSDAY NIGHT COULD CONCEIVABLE FALL INTO THE MID TO UPPER TEENS
IN THE WEST TO NORTHWEST FLOW THAT WILL BECOME ESTABLISHED BEHIND
YET ANOTHER DEARLY DEPARTED COLD FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 103 AM EST FRI FEB 27 2015
EXPECT SNOW SHOWERS TO CONTINUE INTO THE MORNING HOURS BUT WILL BE
ENDING FROM NORTHWEST TO SOUTHEAST. WITH THIS...THERE WILL BE IFR
TO MVFR CIGS AND VISIBILITY TO ACCOMPANY THIS ACTIVITY THROUGH
DAWN. WINDS WILL GENERALLY BE OUT OF THE NORTH WITH SOME GUSTS AT
TIMES TO 15 KNOTS BECOMING LIGHTER INTO THE DAY WITH A LESSENING
GRADIENT. BY MIDDAY...THE MVFR CIGS WILL FINALLY LIFT AND VFR
CONDITIONS SHOULD PREVAIL THROUGH THE REST OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
103 AM EST FRI FEB 27 2015
.UPDATE...
ISSUED AT 103 AM EST FRI FEB 27 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE A WEAK ARCTIC
FRONT MOVING THROUGH THE AREA. ASSOCIATED WITH THE FRONT IS SOME
WEAK RETURNS SHOWING SOME FLURRIES AND SNOW SHOWERS. SOME OF THESE
SNOW SHOWERS HAVE PRODUCED A DUSTING AT MOST IN SOME AREAS WITH
SOME VISIBILITIES NEAR A MILE. THIS BAND HAS A FINE EDGE NOW
CROSSING I-64. THIS SHOULD BRING AN END TO THE ACTIVITY INTO THE
MORNING HOURS. HAVE SENT OUT SOME FRESHENED UP GRIDS TO ADDRESS
THIS AND TEMPERATURES AS THE COLDER AIR IS NOW PUSHING THROUGH THE
MIDWEST STATES AND NOW INTO KY. THOUGH NO SIGNIFICANT CHANGE WAS
MADE TO THE ZFP...THE GRIDS HAVE BEEN SENT TO THE NDFD SERVERS.
UPDATE ISSUED AT 945 PM EST THU FEB 26 2015
A DISTURBANCE IS WORKING THROUGH THE GREAT LAKES AND OH VALLEY
REGION AND IS BRINGING SOME VERY LIGHT SNOW OR FLURRIES TO THE
REGION. AWOS AND ASOS SITES OVER CENTRAL AND NORTHERN KY HAVE
REPORTED SNOW REACHING THE GROUND...BUT THE AIRMASS IS RATHER
DRY...SO VISIBILITIES AND CEILINGS HAVE NOT DROPPED ALL THAT FAR.
AT THIS POINT...PER RADAR AND SFC OBS IT APPEARS THAT THE LIGHT
SNOW OR FLURRIES IS NEARING THE SOMERSET TO JACKSON TO SANDY HOOK
LINE. ONLY ONE KY MESONET SITE IN CENTRAL KY HAS RECEIVED
MEASURABLE PRECIPITATION WITH THIS.
THE NEAR TERM MODELS SUCH AS THE HRRR CONTINUE TO HAVE THIS
DIMINISHING AS IT MOVES EAST...BUT IT SEEMS TO CLEARLY BE HOLDING
TOGETHER BETTER THAN THE HRRR IS FORECASTING. THE WINDS ARE BIT
MORE NORTHERLY THAN IDEAL FOR UPSLOPE ALTHOUGH THERE IS A BIT OF
AN UPSLOPE COMPONENT. THE CURRENT FORECAST IS MORE REFLECTIVE OF
THE MOST RECENT NAM AND GFS RUNS AS SEEMS MORE REASONABLE GIVEN
UPSTREAM TRENDS. AT THIS POINT...SLIGHT CHANCE TO CHANCE POPS
APPEAR TO REMAIN IN ORDER AND AN SPS IS ALREADY IN PLACE. SOME
LOCATIONS MAY PICK UP A QUARTER TO A HALF OF AN INCH OF FLUFF
WHILE OTHER LOCATIONS MAY ONLY GET A LIGHT DUSTING OR NOTHING AT
ALL. THE BIGGER STORY WILL BE THE COLDER AIR WORKING INTO THE
REGION LATE TONIGHT. LOWS SHOULD REACH THE UPPER SINGLE DIGITS
ABOVE ZERO NORTH...WITH UPPER TEENS NEAR THE TN BORDER. TEMPS WILL
STRUGGLE TO REACH THE MID TO UPPER 20S IN MANY LOCATIONS ON
FRIDAY...ALTHOUGH FRI NIGHT APPEARS TO BE COLDER ON AVERAGE THAN
TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 355 PM EST THU FEB 26 2015
19Z SFC ANALYSIS SHOWS LOW PRESSURE PASSING BY TO THE EAST WHILE A
DEEP LOW IS APPROACHING FROM THE NORTHWEST. AN ARCTIC COLD FRONT
FROM THIS IS MOVING INTO KENTUCKY AND THIS WILL SWEEP ACROSS
EASTERN KENTUCKY LATER THIS EVENING. ON REGIONAL RADAR...THE LIGHT
SNOW ASSOCIATED WITH THIS BOUNDARY IS STARTING TO SETTLE DEEPER
INTO THE STATE. EAST KENTUCKY SAW PARTLY SUNNY SKIES THIS
AFTERNOON WITH SOME LOW CLOUDS CLINGING TO OUR FAR EASTERN AREAS
WHILE HIGH CLOUDS PASSED THROUGH NORTHERN PARTS OF THE CWA. LOWER
CLOUDS ARE INBOUND FROM WESTERN AND CENTRAL KENTUCKY NOW...AHEAD
OF THAT FRONT. TEMPERATURES WERE ABLE TO SPIKE UP TO NEAR 40
DEGREES FOR MUCH OF THE AREA THIS AFTERNOON THANKS TO THE PARTIAL
SUNSHINE WHILE ONLY LOW 30S WERE ACHIEVED IN THE NORTHWEST.
DEWPOINTS REMAIN IN THE TEENS IN THE NORTHWEST WHILE LOWER AND
MIDDLE 20S ARE FOUND IN THE EAST. WINDS WERE GENERALLY FROM THE
NORTHWEST AT 5 TO 10 MPH WITH GUSTS TO 15 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT AS A WEAK WAVE PASSES TO
THE SOUTH OF THE AREA THIS EVENING FOLLOWED BY A STRONGER AND
LARGER TROUGH THAT SETTLES INTO THE OHIO VALLEY TONIGHT. THIS
TROUGH WILL BRING ITS CORE ENERGY ACROSS OHIO DURING THE DAY
FRIDAY BEFORE TAPERING OFF AMIDST REBOUNDING HEIGHTS OVER KENTUCKY
FRIDAY NIGHT. THE ECMWF IS A BIT QUICKER THAN THE OTHER MODELS
WITH THESE HEIGHT RISES AND MAY BE GETTING AHEAD OF ITSELF. GIVEN
THE GENERAL AGREEMENT...AT LEAST INTO FRIDAY EVENING...HAVE
FAVORED THE HIGHER RESOLUTION MODEL GUIDANCE FROM THE HRRR...
RAP13...AND NAM12 FOR WX SPECIFICS.
SENSIBLE WEATHER WILL FEATURE CLOUDS ARRIVING ALONG WITH SNOW
SHOWERS THIS EVENING AND CONTINUING THROUGH THE NIGHT IN
ASSOCIATION WITH THE ARCTIC AIR POURING BACK INTO THIS PART OF THE
STATE. TEMPERATURES WILL FALL INTO THE TEENS IN MOST PLACES BY
DAWN THANKS TO THE CAA WITH SOME SINGLE DIGITS POSSIBLE NORTH OF
INTERSTATE 64. ANY LINGERING SNOW SHOWERS WILL COME TO AN END
FRIDAY MORNING IN FAR EASTERN PARTS OF THE AREA WITH SOME SUNSHINE
POSSIBLE BY AFTERNOON...BUT TEMPERATURES WILL STILL STRUGGLE TO
MAKE IT INTO THE LOWER 20S BY MIDDAY. THIS SETS THE STAGE FOR A
VERY CHILLY NIGHT WITH SINGLE DIGITS LIKELY ON TAP FOR THE VALLEYS
AND MORE OPEN AREAS...WHILE SOME LATE ARRIVING HIGH CLOUDS AND THE
INVERSION MAY SPARE THE RIDGES THE COLDEST OF THE AIR. CANNOT RULE
OUT SOME FLURRIES ARRIVING TOWARD DAWN SATURDAY AHEAD OF THE NEXT
SYSTEM...BUT HAVE LEFT THEM OUT FOR NOW.
AGAIN USED THE CONSSHORT TO JUMP START THE T/TD/WIND GRIDS
THROUGH THE DAY FRIDAY...WITH SOME TERRAIN BASED ADJUSTMENTS MADE
AT NIGHT. AFTER THAT...USED THE SUPERBLEND TO INITIATE THE GRIDS
INTO SATURDAY MORNING WITH MINOR CHANGES. AS FOR POPS...ENDED UP
ON THE HIGH SIDE...CLOSER TO THE MET...OF RATHER LOW MOS GUIDANCE
TONIGHT...THEN SIMILAR FOR THE REST OF THE SHORT TERM.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 400 PM EST THU FEB 26 2015
BROAD MID AND UPPER LEVEL TROUGH ACROSS THE ENTIRE CONUS WILL DEEPEN
OVER THE FAR SOUTHWEST...BAJA THROUGH THE WEEKEND PLACING OUR AREA
IN A GENERAL SOUTHWEST FLOW REGIME FOR THE BULK OF THE EXTENDED.
THIS WILL TEND TO KEEP STORM TRACKS SOMEWHAT CENTERED OVER THE OHIO
VALLEY REGION AS A SERIES OF DISTURBANCES RIDE NORTHEAST ACROSS THE
EASTERN CONUS. OVERALL IT APPEARS WE WILL BE GETTING INTO A VERY
ACTIVE WEATHER PATTERN...TYPICAL FOR THE APPROACH OF EARLY SPRING.
ACTUAL SENSIBLE WEATHER...PRECIPITATION TYPES...AMOUNTS ETC. WILL
DEPEND MORE ON EXACT TRACK OF SURFACE LOWS THROUGH THE REGION.
CONSIDERING THE CURRENT SNOWPACK ALONG WITH THE WATER CONTENT
PRESENT ACROSS A LARGE PART OF THE AREA...POTENTIAL HYDRO ISSUES
WILL NEED TO BE CONSIDERED SHOULD MUCH OF ANY PRECIPITATION WE
REALIZE THROUGH THE PERIOD FALL IN THE FORM OF RAIN.
MODEL SOLUTIONS APPEAR TO BE IN FAIRLY GOOD AGREEMENT THROUGH THE
EXTENDED. A SERIES OF STORM SYSTEMS SHOOT OUT OF THE INTER-MOUNTAIN/
SOUTH CENTRAL PLAINS AREA IN RAPID FIRE FASHION THROUGH THE PERIOD.
THE FIRST SHOULD AFFECT OUR AREA SUNDAY INTO MONDAY...THE SECOND
TUESDAY THROUGH EARLY WEDNESDAY AND THEN THE THIRD LATE WEDNESDAY
NIGHT INTO THURSDAY. ATTM MODEL CONSENSUS IS FOR SFC LOWS TO TRACK
GENERALLY TO OUR NORTHWEST...KEEPING OUR AREA IN THE WARM SECTORS OF
THESE SYSTEMS. HOWEVER...THE COLDER AIR THAT FILTERS IN BEHIND EACH
PASSING SYSTEM MAY ALLOW FOR THE A WINTRY MIX AT THE ONSET OF EACH
NEW ROUND OF WEATHER. THIS MAY BE ESPECIALLY TRUE NEXT TUESDAY
MORNING. AFTER A VERY COLD START FOR FRIDAY...EXPECT TEMPERATURES TO
GRADUALLY MODERATE TOWARDS MORE NORMAL LEVELS THROUGH THE EXTENDED
THOUGH OVERALL WE WILL REMAIN BELOW NORMS FOR THIS TIME OF THE
YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 103 AM EST FRI FEB 27 2015
EXPECT SNOW SHOWERS TO CONTINUE INTO THE MORNING HOURS BUT WILL BE
ENDING FROM NORTHWEST TO SOUTHEAST. WITH THIS...THERE WILL BE IFR
TO MVFR CIGS AND VISIBILITY TO ACCOMPANY THIS ACTIVITY THROUGH
DAWN. WINDS WILL GENERALLY BE OUT OF THE NORTH WITH SOME GUSTS AT
TIMES TO 15 KNOTS BECOMING LIGHTER INTO THE DAY WITH A LESSENING
GRADIENT. BY MIDDAY...THE MVFR CIGS WILL FINALLY LIFT AND VFR
CONDITIONS SHOULD PREVAIL THROUGH THE REST OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GREIF
LONG TERM...SBH
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1241 PM EST FRI FEB 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EST FRI FEB 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC.
SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS
SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR
MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z
PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT
OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z
INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE
INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY
DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK
CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA
RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE
PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE
FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT
THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR
LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED
LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F.
MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS
TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED
LOCATIONS NEAR LK SUP THIS MRNG.
TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES
CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE
COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME
WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85
TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH
DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85...
SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR
THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF
MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A
GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE
TEENS APPEAR TO BE ON TRACK.
TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY
12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT
PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER
CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W.
WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY
SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK
CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER
THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB
0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS
/AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER
WIND SHOULD LIMIT THE DIURNAL TEMP DROP.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM EST FRI FEB 27 2015
SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM
OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE
DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST
AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY
SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD
STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN
SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL
APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE
LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY
EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A
SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING.
SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA
THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE
FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED
THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB
TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS
HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT
ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW
A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO
NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT
FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE
EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE
COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT
WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE
SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES
REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES
DURING THE DAY MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN
SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW
TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW
PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION
OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS
PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY
AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO
SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH
SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO
THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND
INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER
WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL
LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE
OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO
TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS
POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS
SAMPLED BETTER OVER THE NEXT FEW DAYS.
WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER
LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE
AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG
WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE
EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY
LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM EST FRI FEB 27 2015
WITH DRY HIGH PRES DOMINATING...VFR CONDITIONS WILL BE THE RULE AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD. THERE MAY BE SOME DIURNAL
CU/STRATOCU THIS AFTN...MAINLY AT KCMX DUE TO VERY LIMITED MOISTURE
ADDED BY SOME BREAKS IN THE ICE COVER ON LAKE SUPERIOR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EST FRI FEB 27 2015
EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR
IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20
TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER
LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A
CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE
ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1202 PM EST FRI FEB 27 2015
.AVIATION...
VERY DRY AIRMASS IN PLACE...BUT DEVELOPING LIGHT LOW LEVEL SOUTHWEST
FLOW IS ALLOWING LAKE INDUCED CLOUDS FROM LAKE MICHIGAN TO ADVECT
EASTWARD...AND IT APPEARS MBS WILL HAVE TO DEAL WITH THE LOW
VFR/BORDERLINE MVFR CEILINGS THIS AFTERNOON INTO THIS EVENING...WITH
DIMINISHING CHANCES FARTHER SOUTH...AS STRONG SURFACE HIGH ACROSS
THE NORTHERN OHIO VALLEY SHOULD ASSURE CLEAR SKIES TONIGHT ACROSS
THE DETROIT TAFS WITH NEARLY CALM WINDS. MOSTLY CLEAR SKIES WILL
PERSIST INTO TOMORROW...WITH JUST INCREASING MID/HIGH CLOUDS LATE
IN THE DAY.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE IN CEILING BELOW 5000 FT THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 846 AM EST FRI FEB 27 2015
UPDATE...
ANOTHER RECORD SETTING COLD MORNING AS ALL THREE CLIMATE SITES
BROKE OR TIED THEIR RESPECTIVE DAILY RECORDS.
FNT LOW WAS AT LEAST -17 F (UNABLE TO DIAL IN TO GET FINAL VALUE).
SAGINAW LOW WAS -9 AT 707 AM.
DETROIT TIED RECORD LOW...WITH -4 F AT 717 AM.
12Z DTX SOUNDING INDICATED A 925 MB TEMP OF -19 C...AND WITH THE
COLD START AND SOME LAKE CLOUDS EXPECTED TO PUSH EAST THIS
AFTERNOON (SEE RUC13 925 MB RH) UNDER LIGHT WESTERLY
FLOW...ESPECIALLY NORTHERN AREAS...MAXES WILL PROBABLY ONLY TOP
OUT IN THE MID TEENS...ON THE LOWER END OF THE GOING FORECAST.
PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015
SHORT TERM...TODAY AND TONIGHT
RECORD LOWS FOR FEB 27
DETROIT AREA: -4 (1934)
FLINT AREA: -14 (1994)
SAGINAW: -8 (1934)
ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC
SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED
TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES
CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A
LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR
SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH
MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A
DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS
AND NOT ISSUE A WIND CHILL ADVISORY.
COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN
COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF
OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A
CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN
CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO
SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE
EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE
DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE
NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR
CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE
FOR HIGHS.
SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET
ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA.
LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE
GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME
POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL
FOR TONIGHT.
LONG TERM...
COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH
TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC
HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS
ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING
INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS
EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH
OF A LOW PRESSURE SYSTEM.
00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS
FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69
CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2
TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY
CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE
RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS
IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO
4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD.
TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE
REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH
THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT.
THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A
STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD
SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY
WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX
AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND
STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT
DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF
SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND
ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA.
MARINE...
HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY
THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW
WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL
SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE
15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE
AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A
WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF
COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE
LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......SF
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
846 AM EST FRI FEB 27 2015
.UPDATE...
ANOTHER RECORD SETTING COLD MORNING AS ALL THREE CLIMATE SITES
BROKE OR TIED THEIR RESPECTIVE DAILY RECORDS.
FNT LOW WAS AT LEAST -17 F (UNABLE TO DIAL IN TO GET FINAL VALUE).
SAGINAW LOW WAS -9 AT 707 AM.
DETROIT TIED RECORD LOW...WITH -4 F AT 717 AM.
12Z DTX SOUNDING INDICATED A 925 MB TEMP OF -19 C...AND WITH THE
COLD START AND SOME LAKE CLOUDS EXPECTED TO PUSH EAST THIS
AFTERNOON (SEE RUC13 925 MB RH) UNDER LIGHT WESTERLY
FLOW...ESPECIALLY NORTHERN AREAS...MAXES WILL PROBABLY ONLY TOP
OUT IN THE MID TEENS...ON THE LOWER END OF THE GOING FORECAST.
&&
.AVIATION...ISSUED 550 AM EST FRI FEB 27 2015
SURFACE HIGH PRESSURE BUILDING EASTWARD INTO THE REGION WILL
CONTINUE TO SUPPORT A VERY DRY AIR MASS. WIND DIRECTIONS ARE
FORECASTED TO EMERGE SOUTHWESTERLY TODAY...BRINGING THE POTENTIAL
FOR LAKE MICHIGAN MOISTURE TO WORK UNDER THE INVERSION BASE AT 4-5
KFT AGL. MODEL SOUNDINGS ALSO SUPPORT A DIURNAL COMPONTENT TO
POTENTIAL CLOUD COVER. DOWNSTREAM TRAJECTORY CONTINUES TO SUPPORT
THE BEST POTENTIAL FOR THE NORTHERN TAF SITES.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015
SHORT TERM...TODAY AND TONIGHT
RECORD LOWS FOR FEB 27
DETROIT AREA: -4 (1934)
FLINT AREA: -14 (1994)
SAGINAW: -8 (1934)
ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC
SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED
TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES
CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A
LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR
SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH
MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A
DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS
AND NOT ISSUE A WIND CHILL ADVISORY.
COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN
COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF
OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A
CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN
CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO
SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE
EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE
DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE
NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR
CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE
FOR HIGHS.
SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET
ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA.
LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE
GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME
POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL
FOR TONIGHT.
LONG TERM...
COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH
TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC
HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS
ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING
INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS
EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH
OF A LOW PRESSURE SYSTEM.
00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS
FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69
CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2
TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY
CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE
RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS
IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO
4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD.
TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE
REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH
THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT.
THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A
STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD
SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY
WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX
AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND
STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT
DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF
SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND
ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA.
MARINE...
HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY
THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW
WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL
SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE
15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE
AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A
WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF
COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE
LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SF
AVIATION.....99
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
619 AM EST FRI FEB 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EST FRI FEB 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC.
SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS
SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR
MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z
PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT
OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z
INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE
INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY
DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK
CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA
RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE
PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE
FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT
THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR
LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED
LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F.
MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS
TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED
LOCATIONS NEAR LK SUP THIS MRNG.
TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES
CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE
COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME
WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85
TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH
DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85...
SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR
THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF
MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A
GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE
TEENS APPEAR TO BE ON TRACK.
TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY
12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT
PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER
CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W.
WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY
SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK
CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER
THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB
0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS
/AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER
WIND SHOULD LIMIT THE DIURNAL TEMP DROP.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM EST FRI FEB 27 2015
SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM
OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE
DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST
AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY
SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD
STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN
SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL
APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE
LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY
EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A
SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING.
SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA
THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE
FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED
THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB
TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS
HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT
ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW
A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO
NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT
FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE
EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE
COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT
WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE
SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES
REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES
DURING THE DAY MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN
SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW
TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW
PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION
OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS
PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY
AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO
SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH
SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO
THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND
INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER
WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL
LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE
OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO
TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS
POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS
SAMPLED BETTER OVER THE NEXT FEW DAYS.
WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER
LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE
AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG
WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE
EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY
LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 618 AM EST FRI FEB 27 2015
WITH DRY HI PRES DOMINATING...EXPECT VFR CONDITIONS TO PREDOMINATE
AT THE TAF SITES THIS FCST PERIOD. NOT OUT OF THE QUESTION THERE
COULD BE SOME MVFR CIGS AS DIURNAL CU/SC DEVELOP LATE THIS MRNG/
AFTN...BUT ABSENCE OF THESE CLDS UPSTREAM YDAY...RELATIVELY LO
SUBSIDENCE INVRN BASE AND ICE COVER ON LK SUP THAT WL RESTRICT
MOISTENING OF THE AIRMASS INDICATE THE CHC IS TOO LO TO INCLUDE IN
THE TAFS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EST FRI FEB 27 2015
EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR
IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20
TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER
LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A
CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE
ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
550 AM EST FRI FEB 27 2015
.AVIATION...
SURFACE HIGH PRESSURE BUILDING EASTWARD INTO THE REGION WILL
CONTINUE TO SUPPORT A VERY DRY AIR MASS. WIND DIRECTIONS ARE
FORECASTED TO EMERGE SOUTHWESTERLY TODAY...BRINGING THE POTENTIAL
FOR LAKE MICHIGAN MOISTURE TO WORK UNDER THE INVERSION BASE AT 4-5
KFT AGL. MODEL SOUNDINGS ALSO SUPPORT A DIURNAL COMPONTENT TO
POTENTIAL CLOUD COVER. DOWNSTREAM TRAJECTORY CONTINUES TO SUPPORT
THE BEST POTENTIAL FOR THE NORTHERN TAF SITES.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 358 AM EST FRI FEB 27 2015
SHORT TERM...TODAY AND TONIGHT
RECORD LOWS FOR FEB 27
DETROIT AREA: -4 (1934)
FLINT AREA: -14 (1994)
SAGINAW: -8 (1934)
ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC
SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED
TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES
CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A
LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR
SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH
MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A
DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS
AND NOT ISSUE A WIND CHILL ADVISORY.
COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN
COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF
OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A
CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN
CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO
SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE
EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE
DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE
NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR
CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE
FOR HIGHS.
SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET
ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA.
LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE
GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME
POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL
FOR TONIGHT.
LONG TERM...
COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH
TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC
HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS
ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING
INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS
EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH
OF A LOW PRESSURE SYSTEM.
00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS
FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69
CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2
TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY
CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE
RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS
IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO
4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD.
TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE
REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH
THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT.
THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A
STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD
SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY
WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX
AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND
STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT
DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF
SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND
ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA.
MARINE...
HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY
THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW
WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL
SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE
15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE
AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A
WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF
COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE
LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....99
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 AM EST FRI FEB 27 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 402 AM EST FRI FEB 27 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR GREAT LKS TO THE SW OF CLOSED H5 LO OVER NRN QUEBEC.
SHRTWV RDG AXIS STRETCHING FM THE NRN PLAINS INTO NW ONTARIO IS
SUPPORTING A SFC HI PRES STRETCHING FM THE NRN PLAINS INTO IOWA. UPR
MI IS DOMINATED BY A DRY WNW LLVL FLOW E OF THIS HI CENTER /00Z
PWATS UPSTREAM ARE GENERALLY 0.05 TO 0.10 INCH...NO MORE THAN 50 PCT
OF NORMAL/. COMBINATION OF THE DRYNESS OF THE UPSTREAM AIRMASS...00Z
INL AND YPL RAOBS SHOW AN INVERTED V T/TD PROFILE BLO SUBSIDENCE
INVRN NEAR H9...AND EXTENSIVE ICE COVER OVER LK SUP HAS GREATLY
DIMINISHED THE LES. IN FACT...IR STLT IMAGERY SHOWS ONLY PATCHY LK
CLDS STREAMING INTO AREAS E OF MUNISING. 00Z H85 TEMPS OVER THE AREA
RANGE FM -23C AT GRB TO -19C AT INL/YPL AND THEN UP TO -16C AT THE
PAS MANITOBA. UNDER THE MOCLR SKIES/DRY ARCTIC AIRMASS...TEMPS HAVE
FALLEN WELL BLO ZERO OVER THE INTERIOR AND AS LO AS -25F TO -30F AT
THE MORE SHELTERED RURAL SPOTS. WINDS ARE STIRRING A BIT MORE NEAR
LK SUP UNDER A TIGHTER PRES GRADIENT...AND SOME OF THE MORE EXPOSED
LOCATIONS THERE ARE INDICATING WIND CHILLS AS LO AS -25F.
MAIN FCST CONCERNS THRU TNGT WL BE ON TEMPS. OPTED TO ISSUE AN SPS
TO COVER WIND CHILLS NEAR ADVY CRITERIA AT THE MORE EXPOSED
LOCATIONS NEAR LK SUP THIS MRNG.
TODAY...AS SHRTWV RDG TO THE NW SLIDES TO THE SE...SFC HI PRES
CENTER IS FCST TO SHIFT TO INDIANA/ILLINOIS BY 00Z SAT. THE
COMBINATION OF ONGOING SUBSIDENCE AHEAD OF THE SHRTWV RDG AND SOME
WAA AS THE SFC-H925 FLOW BACKS TO THE WSW...IS FCST TO RAISE H85
TEMPS UP TO -16 TO -17C BY THE END OF THE DAY. GIVEN ABSENCE OF MUCH
DIURNAL CU UPSTREAM YDAY AND LARGER SCALE SUBSIDENCE/WRMG AT H85...
SUSPECT THERE WL ONLY BE SOME SCT DIURNAL CLDS OVER THE INTERIOR
THIS AFTN. AS THE FLOW BACKS...LINGERING LK CLDS/ANY FLURRIES E OF
MUNISING THIS MRNG SHOULD SHIFT OUT OVER LK SUP IN THE AFTN. WITH A
GOOD DEAL OF SUNSHINE...GOING FCST HI TEMPS RECOVERING INTO THE
TEENS APPEAR TO BE ON TRACK.
TNGT...SFC HI PRES IS FCST TO SLIDE INTO THE MID ATLANTIC STATES BY
12Z SUN...WITH STEADY WSW WIND REMAINING IN PLACE UNDER THE TIGHT
PRES GRADIENT TO THE NW OF THIS FEATURE. ALOFT...UPR MI BE UNDER
CONTINUED SUBSIDENCE AHEAD OF ANOTHER SHRTWV RDG APRCHG FM THE W.
WITH A CONTINUED SLOW WARMING OF THE H85 TEMPS...AN ABSENCE OF ANY
SGNFT LLVL MSTR INFLOW AND GENERALY ACYC NATURE OF THE W FLOW...LK
CLDS OVER THE KEWEENAW SHOULD BE SCT AT BEST. ANY LK CLDS/LES OVER
THE E HALF OF THE LK SHOULD REMAIN OFFSHORE. PWAT IS FCST TO BE AOB
0.10 INCH...SO TENDED TO GO AOB THE LO END OF GUIDANCE FOR MIN TEMPS
/AS IS OBSVD THIS MRNG/ IN AREAS AWAY FM LK SUP...WHERE A STEADIER
WIND SHOULD LIMIT THE DIURNAL TEMP DROP.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 402 AM EST FRI FEB 27 2015
SATURDAY INTO SATURDAY NIGHT...A BROAD SURFACE HIGH PRESSURE SYSTEM
OVER MUCH OF THE GREAT LAKES REGION WILL REMAIN IN PLACE THROUGH THE
DAY SATURDAY. THIS WILL KEEP FAIRLY DRY AIR IN PLACE ALLOWING MOST
AREAS OF THE U.P. TO SEE SUNNY SKIES THROUGH THE DAY SATURDAY. BY
SATURDAY NIGHT...THE HIGH PRESSURE CENTER WILL SHIFT EASTWARD
STRETCHING FROM THE NORTHEAST U.S. SOUTHWARD ALONG THE EASTERN
SEABOARD. AT THIS HAPPENS...A WEAK SURFACE TROUGH/COLD FRONT WILL
APPROACH THE AREA FROM THE WEST. OVERALL MOISTURE APPEARS TO BE
LIMITED AND FOCUSED MAINLY TO THE SOUTH OF THE U.P. THEREFORE...ONLY
EXPECTING AN INCREASE IN CLOUD COVER SATURDAY NIGHT WITH ONLY A
SMALL CHANCE OF LIGHT SNOW ACROSS THE U.P. WITH LIMITED/WEAK FORCING.
SUNDAY THROUGH MONDAY...THE SURFACE TROUGH/WEAK COLD FRONT WILL
CONTINUE TO SHIFT EASTWARD AND PASS THROUGH THE UPPER PENINSULA
THROUGH THE DAY SUNDAY. AGAIN...MOISTURE WILL BE LIMITED ALONG THE
FRONT WITH CONTINUED WEAK FORCING. ONLY LIGHT SNOW IS EXPECTED
THROUGH THE DAY SUNDAY. BEHIND THE FRONT...AN UPPER LEVEL 500MB
TROUGH IS POISED TO SWING ACROSS THE U.P. SUNDAY NIGHT. AS THIS
HAPPENS...ENOUGH MOISTURE WILL REMAIN IN PLACE WITH VERY SLIGHT
ADDITIONAL MOISTURE ADDED FROM THE ICE COVER LAKE SUPERIOR TO ALLOW
A CHANCE OF LAKE EFFECT SNOW SHOWERS TO DEVELOP FOR WEST TO
NORTHWEST WIND FAVORED LOCATIONS. DELTA T VALUES WILL BE SUFFICIENT
FOR LAKE EFFECT WITH THE TROUGH AXIS SLIDING ACROSS...BUT LAKE
EFFECT INTENSITY WILL BE LIMITED TO AREAS THAT ANY BREAKS IN THE ICE
COVER OCCURS. ANY LAKE EFFECT THAT IS ABLE TO DEVELOP SUNDAY NIGHT
WILL BE SHORT LIVED AS MUCH DRIER AIR AND HIGH PRESSURE AT THE
SURFACE AND SLIGHT RIDGING ALOFT TO PUSH INTO THE UPPER GREAT LAKES
REGION DURING THE DAY MONDAY. THIS WILL FOR MAINLY SUNNY SKIES
DURING THE DAY MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...THE AFOREMENTIONED HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES...THEN THE EASTERN
SEABOARD MONDAY NIGHT. THIS WILL ALLOW A MORE MOIST SOUTHERLY FLOW
TO DEVELOP ON THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A LOW
PRESSURE SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION
OF THE U.S. ADDITIONALLY...ANOTHER STRONGER WAVE OF ENERGY IS
PROGGED TO PUSH ACROSS CENTRAL CANADA AND WORK TOWARD THE JAMES BAY
AREA. THERE ARE MODEL DIFFERENCES WITH THE PHASING OF THE TWO
SYSTEMS. THE 18Z/26 00Z/27 GFS IS MORE PROGRESSIVE WITH BOTH
SYSTEMS AND THE PHASING OF THE SYSTEMS. THIS WOULD PUSH SNOW INTO
THE AREA AS EARLY AS MONDAY EVENING ON ISENTROPIC UPGLIDE AND
INCREASED MOISTURE IN THE AREA. THE EC 12/26 00Z/27 IS MUCH SLOWER
WITH THE PHASING...KEEPING THE PRECIPITATION OUT OF THE AREA UNTIL
LATE MONDAY NIGHT INTO TUESDAY MORNING. THE BEST CHANCES GIVEN THE
OVERLAP OF THE TWO MODEL SOLUTIONS WOULD BE TUESDAY AFTERNOON INTO
TUESDAY NIGHT...ESPECIALLY FOR THE EAST HALF OF THE U.P. AT THIS
POINT...WILL STICK WITH CHANCE POPS AT LEAST UNTIL THE SYSTEM IS
SAMPLED BETTER OVER THE NEXT FEW DAYS.
WEDNESDAY NIGHT AND THURSDAY...BOTH THE EC AND GFS AGREE ON AN UPPER
LEVEL TROUGH AXIS ALONG WITH DEEPER MOISTURE LINGERING ACROSS THE
AREA DURING THIS TIME PERIOD. THE COLDER TEMPERATURES ALOFT ALONG
WITH ANY ADDITIONAL MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE
EFFECT SNOW CHANCES. AGAIN...THE EXACT LOCATION ALONG WITH INTENSITY
WILL BE LARGELY TIED TO ANY BREAKS IN THE ICE COVER ON LAKE
SUPERIOR. THE FAVORED LOCATIONS BASED SOLELY ON WIND WOULD BE FOR
THE WEST TO WEST NORTHWEST WIND FAVORED SNOW BELTS. GENERALLY...ANY
LAKE EFFECT SNOW SHOULD REMAIN FAIRLY LIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1200 AM EST FRI FEB 27 2015
WEST FLOW COMBINED WITH ICE COVERED LAKE SUPERIOR IS PROHIBITING LAKE
CLOUDS TONIGHT AT THE TAF SITES. EXPECT THIS TO CONTINUE THROUGH MUCH
OF THE TAF PD. THERE IS A CHANCE FOR SOME DIURNAL MVFR CLOUDS TO FORM
AT KSAW DURING THE DAY ON FRI.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 AM EST FRI FEB 27 2015
EXPECT WINDS TO BE UNDER 30 KTS THIS FORECAST PERIOD. LAKE SUPERIOR
IS MAINLY ICE COVERED THIS MORNING. ALTHOUGH SHIFTING WINDS UP TO 20
TO 25 KTS ACCOMPANYING THE PASSAGE OF DISTURBANCES THRU THE UPPER
LAKES MAY CAUSE HOLES TO OPEN IN THE ICE FROM TIME TO TIME...A
CONTINUED DOMINANCE OF ARCTIC AIR WILL MAINTAIN AN OVERALL EXTENSIVE
ICE COVER.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
358 AM EST FRI FEB 27 2015
.SHORT TERM...TODAY AND TONIGHT
RECORD LOWS FOR FEB 27
DETROIT AREA: -4 (1934)
FLINT AREA: -14 (1994)
SAGINAW: -8 (1934)
ANOTHER COLD MORNING ACROSS SOUTHEASTERN MICHIGAN WITH AN ARCTIC
SURFACE RIDGE LOCKED IN OVERHEAD. NIL WIND AND CLEAR SKIES HAS LED
TO FAVORABLE RADIATIVE COOLING CONDITIONS. SURFACE TEMPERATURES
CURRENTLY RANGE FROM 0 TO 10 DEGREES BELOW ZERO AS OF 3AM. WITH A
LACK OF LOW CLOUD DISCERNIBLE IN IR IMAGERY...EXPECTATIONS ARE FOR
SURFACE TEMPERATURES TO CONTINUE TO BOTTOM OUT BEFORE SUNRISE WITH
MANY RURAL LOCATIONS REACHING 10 TO 20 DEGREES BELOW ZERO. WITH A
DECOUPLED SURFACE LAYER...WILL HONOR THE DECISION OF PRIOR SHIFTS
AND NOT ISSUE A WIND CHILL ADVISORY.
COLDEST MIDLEVEL TEMPERATURES PUSHING OUT OF THE STATE TODAY IN
COMBINATION WITH AN SURFACE ANTICYCLONE PUSHING INTO PORTIONS OF
OHIO WILL ALLOW WIND DIRECTIONS OVER SOUTHEASTERN MICHIGAN TO MAKE A
CONCERTED MOVE TO SOUTHWESTERLY. ENHANCED MOISTURE AND LAKE MICHIGAN
CLOUD DEBRIS IS PROGGED TO STREAM EASTWARD WITH TIME...SHOWN TO
SLIDE THROUGH PORTIONS OF THE CWA BY THIS AFTERNOON AND INTO THE
EARLY EVENING. RAP SOUNDINGS SUGGEST THERE WILL BE A CONSIDERABLE
DIURNAL COMPONENT TO ANY SKY COVER. WIND TRAJECTORIES POINT TO THE
NORTHERN CWA/SAGAINAW VALLEY AS THE MORE FAVORABLE LOCATION FOR
CLOUDS. WITH SUN...SHADED A DEGREE OR TWO HIGHER THAN MOS GUIDANCE
FOR HIGHS.
SURFACE HIGH PRESSURE PUSHING THROUGH INDIANA AND OHIO WILL SET
ANOTHER NIGHT UP FOR CALM WINDS ACROSS THE SOUTHERN HALF OF THE CWA.
LOWERED MINS FOR AREAS SOUTH OF DETROIT. OTHERWISE...A PRESSURE
GRADIENT IN PLACE OVER THE TRI CITIES/NORTHERN THUMB AND SOME
POTENTIAL FOR LINGERING CLOUDS LIMITS THE TEMPERATURE FALL POTENTIAL
FOR TONIGHT.
&&
.LONG TERM...
COLD AIRMASS WILL REMAIN IN PLACE INTO EARLY THIS WEEKEND ALTHOUGH
TEMPERATURES WILL MODERATE EVER SO SLIGHTLY AS THE LATEST ARCTIC
HIGH PRESSURE SHIFTS TO THE EAST OF THE AREA SATURDAY NIGHT. HIGHS
ON SATURDAY WILL CLIMB TO AROUND 20F WITH LOWS THAT NIGHT HOLDING
INTO THE SINGLE DIGITS TO NEAR 10F AS BOTH THE COLDEST AIR SHIFTS
EAST AND EXPANDING CLOUD COVER WORKS INTO THE AREA WITH THE APPROACH
OF A LOW PRESSURE SYSTEM.
00Z MODEL RUNS...SAVE THE NAM12...BASICALLY SUPPORT THE PREVIOUS
FORECAST AS ROUGHLY 1 TO 2 INCHES OF SNOW FALL FROM THE I-69
CORRIDOR NORTH LATE SATURDAY NIGHT INTO EARLY SUNDAY EVENING WITH 2
TO 3 INCHES SOUTH OF THAT INTO METRO DETROIT AS H7 SPECIFIC HUMIDITY
CLIMBS TO AROUND 2 G/KG ALONG THE M-59 CORRIDOR. GIVEN THE
RELATIVELY HIGH SNOW TO LIQUID RATIOS EXPECTED WITH THE COLD AIRMASS
IN PLACE...15:1 OR A BIT MORE...WOULD NOT BE SURPRISED TO SEE UP TO
4 INCHES FROM THE I-94 CORRIDOR SOUTHWARD.
TEMPERATURES WILL EDGE BACK DOWN EARLY NEXT WEEK...BUT TO MUCH MORE
REASONABLE LEVELS THAN THE PAST SEVERAL WEEKS AS HIGHS MONDAY REACH
THE MID/UPPER 20S AND LOWS HOLD IN THE TEENS SUNDAY AND MONDAY NIGHT.
THE NEXT LOW PRESSURE SYSTEM APPEARS TO BE SHAPING UP TO BE A
STRONGER SYSTEM THAN THE WEEKEND EVENT...WITH A TRACK THAT WOULD
SUPPORT A WIDE VARIETY OF PRECIPITATION ACROSS THE CWA ON TUESDAY
WITH PRIMARILY SNOW OVER THE NORTHERN CWA AND SNOW CHANGING TO A MIX
AND THEN EVENTUALLY RAIN FURTHER SOUTH. WITH THE EVENTUAL TRACK AND
STRENGTH OF THIS SYSTEM STILL IN DOUBT...WILL FORGO ANY SIGNIFICANT
DETAILS AT THIS TIME...OTHER THAN TO INCLUDE SOME MENTION OF
SLEET...FREEZING RAIN AND RAIN AS 00Z RUNS OF THE GFS...CMC AND
ECMWF DO NOT SUPPORT AN ALL SNOW EVENT FOR THE ENTIRE CWA.
&&
.MARINE...
HIGH PRESSURE WILL BE BUILD FROM THE MID MISSISSIPPI VALLEY TODAY
THROUGH THE OHIO VALLEY ON SATURDAY. MODEST SOUTHWEST RETURN FLOW
WILL DEVELOP AROUND THIS HIGH OVER THE CENTRAL GREAT LAKES. CENTRAL
SECTIONS OF LAKE HURON WILL MOST LIKELY SEE WINDS INCREASE INTO THE
15 TO 20 KNOT RANGE. OTHERWISE...WINDS WILL REMAIN ON THE LIGHT SIDE
AS THIS SOUTHWEST PRESSURE GRADIENT WEAKENS LATE IN THE WEEKEND AS A
WEAK LOW PRESSURE SYSTEM LIFTS INTO THE REGION. EVEN THE RETURN OF
COLD NORTHWEST FLOW IN THE WAKE OF THE ATTENDING COLD FRONT WILL BE
LIMITED TO 25 KNOT GUSTS OR LESS OVER MUCH OF LAKE HURON.
&&
.AVIATION...ISSUED 1153 PM EST THU FEB 26 2015
EXISTING ARCTIC HIGH PRESSURE WILL LARGELY SUSTAIN A DRY/STABLE
ENVIRONMENT INTO FRIDAY. SOME THIN POCKETS OF STRATUS NOTED
DEVELOPING IN THE VICINITY OF MBS MAY PROVIDE A BRIEF MVFR CEILING
EARLY THIS MORNING AT MBS/FNT...BUT LIMITED COVERAGE AND DURATION
WILL SUPPORT A PREVAILING VFR. A BACKING FLOW TOWARD THE WEST AND
THEN SOUTHWEST WILL SUPPORT A PERIOD OF LOW VFR DIURNAL STRATO CU
DEVELOPMENT FRIDAY AFTERNOON...GREATER COVERAGE SEEMINGLY MORE
LIKELY ACROSS THE NORTHERN TAF SITES.
//DTW THRESHOLD PROBABILITIES...
* LOW CONFIDENCE IN CEILING BELOW 5000 FT FRIDAY AFTERNOON.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
AVIATION.....MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
916 PM CST SAT FEB 28 2015
.UPDATE...SURFACE ANALYSIS AT 02Z SHOWING STATIONARY BOUNDARY
EXTENDING FROM KESF-KTVR-KMKL. TEMPS GENERALLY IN THE 50S ON THE EAST
SIDE WITH 40S ON THE WEST. NO REAL PUSH SEEM WITH SURFACE WINDS NOR
WINDS ALOFT AS THEY ARE ALL PARALLEL TO THE BOUNDARY.
WHILE WEAK ISENTROPIC ASCENT IS RESULTING IN SOME LIGHT PRECIP IN
AR/W LA/E TX...DECIDED TO HOLD OFF ON POPS IN THE FAR WEST AS 00Z JAN
UA SOUNDING IS SHOWING A VERY DRY AIRMASS BELOW 750 MB. LIGHT PRECIP
WOULD HAVE TO FALL THROUGH THIS LAYER A WHILE BEFORE ANY COULD REACH
GROUND.
ANOTHER FEATURE TO NOTE THIS EVENING...OBSERVATIONS ARE SHOWING A
WESTWARD SURGE IN DEWPOINTS OVER S AL. HRRR HAS PICKED UP ON THIS AND
IS SHOWING TEMPS RISE OVERNIGHT IN EAST MS AS THIS MOISTURE MOVES IN./26/
&&
.AVIATION...CIGS/VSBY WILL STEADILY LOWER TO MVFR OVERNIGHT AS
MOISTURE INCREASES FROM THE EAST. CIGS WILL EVENTUALLY BECOME IFR
AFTER 12Z AS AREAS OF LIGHT RAIN SPREAD OVER THE REGION./26/
&&
.PREV DISCUSSION... /ISSUED 423 PM CST SAT FEB 28 2015/
DISCUSSION...IT TURNED OUT TO BE QUITE A NICE DAY ACROSS THE
ARKLAMISS REGION FOR THE LAST DAY OF METEOROLOGICAL WINTER. WHILE THERE
HAVE BEEN SOME HIGH CLOUDS PRESENT...THERE HAS BEEN ENOUGH SUN TO
ALLOW TEMPERATURES TO REALLY WARM UP GENERALLY ALONG AND SOUTH OF THE
NATCHEZ TRACE CORRIDOR. READINGS HAVE REACHED INTO THE MID 60S IN
THIS REGION WHERE AS TEMPERATURES IN THE DELTA REMAIN IN THE UPPER
40S THANKS IN PART TO THOSE CLOUDS. NEVERTHELESS...3PM TEMPERATURES
ARE ABOUT 15 TO 20 DEGREES WARMER THAN THIS TIME YESTERDAY AND THIS
IS WELCOME FOR MANY ACROSS THE ARKLAMISS. WINDS HAVE SHIFTED AROUND
OUT OF THE SOUTH/SOUTHEAST WHICH IS HELPING TO WARM TEMPERATURES AND
WILL BEGIN TO INCREASE MOISTURE ACROSS THE REGION.
THE UPCOMING WEEK WILL START OFF ON THE WARMER SIDE BUT HAVE CHANCES
FOR RAIN THROUGH THE FIRST FEW DAYS. THEN ANOTHER DRASTIC CHANGE
WILL OCCUR AND ANOTHER ROUND OF WINTRY PRECIPITATION NOW LOOKS
POSSIBLE DURING MID-WEEK. AS MOISTURE STARTS TO RETURN TO THE REGION
THIS WILL LEAD TO SOME SHOWERS LATE TONIGHT IN THE WEST...SPREADING
EAST THROUGH THE DAY SUNDAY. THIS RAIN WILL CONTINUE INTO MONDAY
WITH THE HIGHEST CHANCES BEING ALONG THE HIGHWAY 82 CORRIDOR.
ANOTHER WEAK COLD FRONT WILL DROP INTO THE REGION ON MONDAY BUT
SHOULD STALL GENERALLY ALONG OR JUST SOUTH OF THE I-20 CORRIDOR.
THIS WILL BRING SOME COOLER TEMPERATURES TO THE REGION ON MONDAY
ALONG WITH CONTINUED CHANCES FOR RAIN. HOWEVER...LOCATIONS SOUTH OF
THE FRONT SHOULD STILL SEE READINGS INTO THE LOWER TO MID 60S.
THIS FRONT WILL RETURN NORTH AS A WARM FRONT MONDAY NIGHT...SHIFTING
THE BULK OF THE RAIN NORTH OF THE CWA INTO NORTHERN MISSISSIPPI.
THIS WILL LEAVE THE ENTIRE ARKLAMISS REGION INTO THE WARM SECTOR.
MONDAY NIGHT SHOULD BE ONE OF THOSE SCENARIOS THANKS TO THE
NORTHWARD MOVING WARM FRONT WHERE OVERNIGHT TEMPERATURES RISE
THROUGH THE NIGHT. TUESDAY WILL BE A VERY WARM DAY ACROSS THE
ARKLAMISS THANKS TO UPPER RIDGING OVER THE NORTHERN GULF. HIGHS
SHOULD REACH INTO THE 70S AND I ACTUALLY WENT HIGHER THAN WHAT
GUIDANCE WAS GIVING ME FOR HIGHS THAT DAY. TUESDAY NIGHT THE STRONG
COLD FRONT WILL APPROACH THE REGION. THERE COULD BE SOME
THUNDERSTORMS ACCOMPANYING THE FRONT BUT OVERALL SHOWALTER INDICES
ARE NOT VERY NEGATIVE AND INSTABILITY OTHERWISE IS A LITTLE LOW.
HAVE KEPT MOSTLY SHOWERS WITH SOME CHANCES FOR THUNDER. THE COLD
FRONT WILL SWEEP INTO THE REGION ON WEDNESDAY WITH CHANCES FOR
SHOWERS ALONG AND BEHIND THE FRONT.
MODELS HAVE CONTINUED TO TREND A BIT COLDER WITH THIS SYSTEM AND ARE
IN GOOD AGREEMENT OF SOME POTENTIAL OF WINTRY PRECIPITATION
AFFECTING AT LEAST THE NORTHERN PORTIONS OF THE ARKLAMISS STARTING
WEDNESDAY AFTERNOON INTO THURSDAY. WHILE THERE CONTINUES TO BE HIGH
PROBABILITIES OF PRECIPITATION THERE IS SLIGHTLY LOWER CONFIDENCE IN
THE PRECIPITATION TYPE THAT WILL OCCUR. AT THIS TIME...GLOBAL MODELS
AND MODEL BUFR SOUNDINGS INDICATE THAT DURING WEDNESDAY AFTERNOON
THE RAIN SHOULD CHANGE OVER TO FREEZING RAIN AS THE COLDER AIR SINKS
SOUTH INTO THE REGION...WITH THE BEST CHANCES OF THIS OCCURRING
ACROSS NORTHERN SECTIONS OF THE CWA/MISSISSIPPI DELTA. THEN SOMETIME
LATER INTO THE EVENING THERE COULD BE A CHANGEOVER TO SNOW ASSUMING
THERE IS ENOUGH PRECIPITATION LINGERING FOR THAT TO OCCUR. FURTHER
SOUTH...THERE IS LOWER CONFIDENCE AT THIS TIME DESPITE THE BULLISH
NATURE OF THE GFS IN BRINGING THE COLDER AIR SURGING SOUTH DURING
THE TIME OF PRECIPITATION. THIS IS OF COURSE SOMETHING THAT WE WILL
KEEP MONITORING WITH LATER MODEL RUNS. WE HAVE THOUGH INCLUDED
MENTION OF THIS IN THE HWO AND GRAPHICS FOR WEDNESDAY INTO THURSDAY.
BY THURSDAY AFTERNOON THE PRECIPITATION WILL HAVE EXITED TO THE EAST
LEAVING THE REGION UNDER COLD HIGH PRESSURE. SO MUCH FOR THE START
TO METEOROLOGICAL SPRING...WE WILL STILL BE FEELING THE GRIPS OF
WINTER. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 46 63 50 57 / 8 46 60 82
MERIDIAN 47 63 48 57 / 8 18 52 74
VICKSBURG 41 63 49 54 / 8 76 69 85
HATTIESBURG 48 67 52 67 / 8 16 30 49
NATCHEZ 49 64 54 59 / 8 65 58 62
GREENVILLE 33 53 41 46 / 8 85 86 92
GREENWOOD 43 57 44 49 / 8 77 89 93
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
635 PM CST Sat Feb 28 2015
...Winter Weather Advisory Upgraded to a Winter Storm Warning for
Portions of the Ozarks...
.UPDATE...
Issued at 619 PM CST SAT FEB 28 2015
Calls around and social media reports indicate that 4-5" of snow
has now fallen along and north of the I-44 corridor and along and
east of the U.S. 65 corridor. The snow has started accumulating
much more efficiently with the setting sun. With the back edge of
the most organized precipitation just now getting to the KS/MO
line, we still think another 1-3" of snow will fall...especially
along and north of the Ozark Plateau and east of U.S. 65. With
that being said, we have upgraded to a Winter Storm Warning from
Polk and Greene Counties...northeast into the Lake of the Ozarks
and Salem region.
While snow will become lighter from west to east later this
evening, we are expecting the potential for a light wintry mix
overnight and into Sunday morning. Radar and satellite trends as
well as observations indicate freezing drizzle, very light
freezing rain, and even some light sleet pushing in from eastern
Oklahoma and Kansas. Minor ice accumulations will therefore be
left in the forecast as we head into later tonight and Sunday
morning.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 307 PM CST SAT FEB 28 2015
A large area of snow has blanketed all of the Missouri Ozarks and
extreme southeastern Kansas as of mid afternoon. Visibilities were
pretty much below one mile over all areas...with occasional
observations indicating quarter mile visibilities with heavy snow.
Snowfall accumulations up through 3 PM have been in the 1-3"
range. We suspect that some locations across extreme southeastern
Kansas and west-central Missouri may be in that 3-4" range.
As we head into late this afternoon and this evening, short term
models are beginning to change their tune a bit. Both the RAP
and the HRRR have somewhat backed off on a secondary band of snow
developing along the I-44 corridor this evening. Even the 18Z NAM
has trended this way. Instead, models gradually take the large
area of moderate to occasionally heavy snow to the east and
northeast with the back edge of the heavier snow moving east
across the Ozarks this evening. This would tend to make sense as
low level isentropic upglide and a weak upper level jet coupling
structure shift towards the Mid Mississippi Valley. We will still
have to watch for some banding of snow as models do indicate some
slugs of increased 700 mb frontogenesis...especially along and
north of the I-44 corridor.
As we head into later tonight, the main area of snow will have
shifted east of the area. Pockets of light snow and flurries
will be left in its wake. While snow intensity will be on the
downward trend this evening (again from west to east), it will
tend to accumulate more efficiently given that the sun will have
set. Models are also indicating perhaps some loss of cloud ice
later tonight. Additionally, models still bring a warm nose into
southern Missouri by late tonight. Thus, we are continuing a
mention of either light freezing rain or freezing drizzle.
This trend will then continue into Sunday morning with pockets of
light snow and drizzle/freezing drizzle. We have slowed the
progress of the surface freezing line to the north by a few
hours...which does keep the door open a bit longer for minor ice
accumulation. One thing we will have to watch very closely is what
will be a good setup for a banded snow event from late tonight
into Sunday morning up towards I-70. Models continue to indicate
strong 700 mb frontogenesis and available negative EPV becoming
juxtaposed with a favorable upper level jet streak. If this
materializes, it could put down a narrow swath of additional
heavier snowfall. While this could glance our central Missouri
counties, confidence is higher that it will remain just north of
the area. Once we get into Sunday afternoon and especially Sunday
night, the primary precipitation will be shifting east and
southeast of the region.
As for storm total ice and snow amounts, we have not changed much.
Any ice accumulations are still expected to remain at or below
five-hundredths of an inch. 1-3" of snow is expected across
south-central Missouri. Accumulations near and north of the I-44
corridor will be in the 3-6" range. We still think a few isolated
reports of around 7" will be possible. Given that any 6-7" amounts
are expected to be isolated (if they occur at all), the current
Winter Weather Advisory will be left intact.
.LONG TERM...(Monday through Saturday)
Issued at 307 PM CST SAT FEB 28 2015
By Monday morning, precipitation should push south of the region,
at least temporarily, as high pressure noses south from the
Dakotas. Highs on Monday look to reach the upper 30s in most
locations.
Precipitation will then return to the area Monday night into
Tuesday, though at this point it appears that temperatures
should be above freezing by the time rain begins to fall Monday
night. Rain will continue through much of the day Tuesday, as low
pressure at the surface deepens and lifts north across Kansas and
northern Missouri. Breezy southwest winds during the day Tuesday
will help temperatures warm into the low to mid 50s. Will continue
to include a mention of thunder in the forecast for Tuesday, with
guidance suggesting a couple hundred J/KG of CAPE making its way
into the CWA.
A strong cold front will then sweep across the area Tuesday
afternoon and evening, with colder air quickly advecting into
the area Tuesday night. We will need to carefully watch the
potential for post frontal snow Tuesday night and Wednesday, as
lift from a secondary trough axis may be enough to result in areas
of snow on Wednesday. As it stands right now, the highest snow
potential for Wednesday looks to be south of I-44, though this
will be highly dependent on the eventual location of the front.
The upper level flow will then flatten out a bit, with
southwesterly flow developing at the surface for the end of the
week into next weekend. This is suggestive of warmer temperatures
for the end of the week, with highs perhaps (finally) approaching
climatological averages by this time next weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1149 AM CST SAT FEB 28 2015
IFR and LIFR conditions will continue this afternoon and evening
across the region as moderate to at times heavy snow affect the
terminals. Prevailing conditions will likely be just above airport
minimums at SGF and JLN, but dips to or below mins are likely
if/when bands of the heaviest snow move overhead.
Snow intensity should decrease somewhat later tonight, though cigs
will remain low. A south to north transition to a wintry mix of
snow, rain and freezing rain is expected at some point late
tonight, with an eventual changeover to just rain around mid day
tomorrow as temperatures rise above freezing. While this
transition has been indicated in the TAFs, confidence in exact
timing is very low.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055-056-066-
067-077-078-088-089-093>098-101>106.
WINTER STORM WARNING until Noon CST Sunday FOR MOZ057-058-
068>071-079>083-090>092.
KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101.
&&
$$
UPDATE...Schaumann/Cramer
SHORT TERM...Schaumann
LONG TERM...Boxell
AVIATION...Boxell
AREA FORECAST DISCUSSION
NWS HASTINGS NE
604 PM CST SAT FEB 28 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS
AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE
DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE
CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW
THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN
NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN
COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS
TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN
BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW
PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE.
TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM
TEMPS RUNNING THE WHOLE RANGE OF 20S.
WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON
AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE
EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z
TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER
SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER
LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL
PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND
SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS
LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST
INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO
THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN
ADDITION FEW TENTHS OF A INCH OF ACCUMULATION.
HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH
DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS
EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH.
WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY
TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST
ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW
DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN
THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY
AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID
30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE
SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE
MONDAY NIGHT INTO TUESDAY MORNING.
NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP
TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE
FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST
FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS
LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT
UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS
WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS
AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS.
GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF
OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES.
CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH
PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE
NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT
SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC
LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF
SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A
SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE
ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF
AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL
PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND
STICK WITH SNOW.
ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH
SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT
30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES
OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY.
WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO
MENTION IN THE HWO.
ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY
DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR
OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST.
&&
.AVIATION...(FOR THE 00Z KGRI/KEAR TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 543 PM CST SAT FEB 28 2015
THE WIND WILL BECOME LIGHT TONIGHT AND GRADUALLY SHIFT FROM SOUTH
SOUTHWEST TO WESTERLY BY DAWN SUNDAY MORNING. THE WIND WILL
CONTINUE TO VEER AROUND THROUGH SUNDAY MORNING AND SHOULD BE
NORTHERLY JUST PRIOR TO NOON ON SUNDAY. CAN NOT RULE OUT A FEW
MORE FLURRIES SUNDAY MORNING...BUT NOT A BIG ENOUGH DEAL TO
WARRANT MENTION IN THE TAF AT THIS POINT IN TIME. WE MAY BOUNCE
AROUND A BIT BETWEEN MVFR AND VFR CEILINGS THROUGH THE
PERIOD...AND WILL GENERALLY CALL FOR PREVAILING MVFR CONDITIONS
THROUGH SUNDAY MORNING AND LOW END VFR BY SUNDAY AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
332 PM MST FRI FEB 27 2015
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN CONTINUES OVER NORTHERN AND CENTRAL
NEW MEXICO AS A SERIES OF STORM SYSTEMS PUSH OVER THE REGION. AS
ONE UPPER LEVEL DISTURBANCE DEPARTED THE STATE TO THE EAST THIS
MORNING...ANOTHER ONE IS CURRENTLY ARRIVING FROM THE WEST.
ADDITIONAL SNOW ACCUMULATIONS ARE EXPECTED THIS EVENING AND
OVERNIGHT...PRIMARILY IN NORTHWESTERN TO CENTRAL AND NORTH CENTRAL
PARTS OF NEW MEXICO. INTO SATURDAY AND SUNDAY...ANOTHER POTENT
DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER
NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED
OVER NORTH CENTRAL TO NORTHWESTERN NEW MEXICO
SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW
TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE
COLORADO BORDER WHERE AN ADDITIONAL ONE TO TWO FEET OF SNOW COULD
ACCUMULATE...PRIMARILY IN THE HIGHER ELEVATIONS ABOVE EIGHT
THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING THIS
WEEKEND TO EARLY NEXT WEEK PERIOD.
&&
.DISCUSSION...IT`S ANOTHER BUSY AND CHALLENGING FORECAST DAY IN
THE MIDDLE OF A BARRAGE OF UPPER LEVEL DISTURBANCES. NOT MUCH OF A
RESPITE OR LULL IN THE PRECIPITATION WAS OBSERVED THIS MORNING
BEFORE THE NEXT UPSTREAM SYSTEM STARTED SPREADING MORE BATCHES OF
SNOW INTO WETSERN NM. THIS LATTER DISTURBANCE IS A BIT MORE SUBTLE
LOOKING ON WATER VAPOR IMAGERY COMPARED TO ITS
PREDECESSOR...HOWEVER JET DYNAMICS ARE UNDERWAY AND STRENGTHENING
WITH LOTS OF DIVERGENCE ALOFT BEING DEPICTED BY FORECAST MODELS.
THIS SEEMS TO BE QUICKLY COMING TO FRUITION GIVEN LIGHT SNOW THAT
HAS ALREADY ENSUED AND STARTED AGAIN IN CENTRAL TO WESTERN ZONES.
FORECAST MODELS KEEP THIS DIVERGENCE ALOFT PEGGED OVER THE
NORTHWESTERN QUADRANT OF NM TONIGHT...AND QPF IS GENEROUSLY
PAINTED BENEATH. HRRR MODEL IS ALSO QUITE GENEROUS WITH THIS TREND
WITH A FEW MESOSCALE BANDS OF SNOW BEING DEPICTED. THUS...FELT
PRUDENT TO SPATIALLY AND TEMPORALLY EXTEND ADVISORIES/WARNING
WESTWARD AND LONGER RESPECTIVELY. THESE AMENDMENTS WERE MADE AT
NOON AND WILL HOLD FOR NOW.
INTO SATURDAY THE DIVERGENCE SLOWLY DECREASES IN INTENSITY OVER NM
AND THE FLOW ALOFT BEGINS BACKING MORE SOUTHWESTERLY AS A LOW
TAKES SHAPE AND DIVES INTO CA. THIS SHOULD BEGIN A REDUCTION IN
THE COVERAGE OF PRECIPITATION IN SOME LOWER ELEVATION
AREAS...REDUCTION BEING RELATIVE...WHILE OROGRAPHICS BECOME THE
MORE DOMINANT FORCING MECHANISM FOR THE HIGHER TERRAIN. ELEVATIONS
BELOW 7000 FEET WOULD ALSO OBSERVE A QUICK WARMING TREND AS WARM
AIR ADVECTION BEGINS IN THE SOUTHWESTERLY FLOW. THE FORECAST
MODELS MAY BE A BIT TOO HIGH WITH MAX TEMPERATURE GUIDANCE ON THIS
THOUGH...AS THE CLOUD COVER MAY BE SLOW TO ERODE...STUNTING THE
WARMING MORE THAN WHAT IS ADVERTISED BY MODELS. HAVE BUILT IN A
QUICK CHANGEOVER TO RAIN IN THESE LOWER ELEVATIONS BY LATE MORNING
AND INTO THE AFTERNOON...BUT THIS COULD BE A BIT PREMATURE AND
WILL NEED TO BE CLOSELY MONITORED. PRECIPITATION COULD ALSO BEGIN
TO TAKE ON A SHOWERY OR CONVECTIVE NATURE TO IT AS MODELS HAVE
LIFTED INDICES OF 0 TO -1C PROGGED OVER SOME NORTH CENTRAL TO
NORTHWESTERN ZONES SATURDAY AFTERNOON. THIS WOULD ONLY ADD TO SNOW
RATES IN THE HIGHER TERRAIN. THE WINTER HIGHLIGHTS/STATEMENTS IN
THE NORTHWESTERN ZONES DROP OFF SATURDAY MORNING...BUT MAY NEED TO
BE EXTENDED FOR AFOREMENTIONED REASONINGS.
THE PRECIPITATION REALLY FOCUSES TOWARD THE NORTHWESTERN THIRD OF
THE FORECAST AREA INTO SATURDAY NIGHT AND SUNDAY WITH FLOW
CONTINUING TO BACK SLIGHTLY MORE WHILE SPEEDS ALOFT INCREASE. THIS
WILL KEEP STEADY OROGRAPHIC FORCING OVER THE NORTH CENTRAL TO
NORTHWESTERN MOUNTAINS WITH SOME PRONOUNCED PRECIPITATION SHADOWS
DOWNWIND OR NORTHEAST OF CHUSKAS AND OTHER TOPOGRAPHICAL BARRIERS.
THE SOUTHWESTERLY FLOW ALOFT AND RISING PRESSURE HEIGHTS WILL ALSO
KEEP THE WARMER AIR ADVECTING THIS WAY...AND SATURDAY NIGHT`S LOW
TEMPERATURES WILL BE 10 TO 15 DEGREES WARMER THAN TONIGHT`S
READINGS WHILE SUNDAY`S HIGHS RISE ANOTHER 5 TO 15 DEGREES ABOVE
SATURDAY`S HIGHS. THIS WARMING TREND WILL SHIFT SNOWFALL
ACCUMULATIONS UPWARD TO 7500 TO 8500 FEET SUNDAY AFTERNOON. WHILE
THIS WILL LIMIT THE SPATIAL AREA OF SNOWFALL ACCUMULATIONS...THE
PEAKS ABOVE THIS THRESHOLD WILL STILL SEE REMARKABLE SNOW
AMOUNTS...LIKELY ONE TO THREE FEET ON MANY PEAKS ABOVE 8500 FEET
AND CLOSER TO FOUR FEET NEAR THE CO/NM BORDER ABOVE 10000 FEET.
RUNOFF AND SNOW MELT AT LOWER ELEVATIONS WILL ALSO NEED TO BE
MONITORED CLOSELY ON SUNDAY...PERHAPS CREATING HYDROLOGY ISSUES.
AND THE THREAT FOR ACCUMULATION STILL WON`T END THROUGH MONDAY AS
THE UPPER LOW ROUNDS SOUTHERN CA AND DRIVES A PACIFIC FRONT CLOSER
TO NM...EVENTUALLY CROSSING INTO OUR FORECAST AREA MONDAY NIGHT.
THIS FRONTOGENETICAL FORCING IN ITSELF WILL ALSO INDUCE A HEALTHY
SLUG OF PRECIPITATION...POSSIBLY ENHANCED BY A SUBTROPICAL
MOISTURE TAP. THEN A KICKER SHORT WAVE TROUGH WILL DIG ON THE BACK
SIDE OF THIS BEFORE TURNING INTO OLD MEXICO TUESDAY AND EARLY
WEDNESDAY. FINALLY THE CABOOSE IN THE TRAIN OF STORM SPILLS
SOUTHWARD IN STRONG MERIDIONAL FLOW ON WEDNESDAY...UNLOCKING THE
DOOR TO SOME VERY COLD CONTINENTAL POLAR AIR. ONCE THIS SYSTEM
PASSES...A WELCOME DRIER PATTERN SHOULD FOLLOW INTO THURSDAY OF
NEXT WEEK.
52
&&
.FIRE WEATHER...
AN ACTIVE WEATHER PATTERN WILL PERSIST THROUGH THE MIDDLE OF NEXT
WEEK. MOIST WESTERLY FLOW WILL CONTINUE OVER NORTHERN AND CENTRAL
NEW MEXICO TONIGHT AND SATURDAY...ALLOWING WEST FACING HIGHER
TERRAIN LOCATIONS...ESPECIALLY FROM THE WEST CENTRAL TO THE NORTH
CENTRAL...TO CONTINUE PICKING UP SNOW. THE WINDS ALOFT TRANSITION TO
SOUTHWEST SUNDAY INTO MONDAY AS AN UPPER LOW/TROUGH DIG INTO SOCAL
AND ARIZONA. TEMPERATURES WILL WARM IN ADVANCE OF THE LOW...ALLOWING
SNOW LEVELS TO GRADUALLY RISE FROM WHAT THEY ARE THIS AFTERNOON.
SOME COOLER AIR MAY ENTER THE EASTERN PLAINS SUNDAY...BOTH ECMWF AND
GFS AGREE...BUT LOOKS LIKE IT MERELY RETARDS WARMING IN THE PLAINS
FOR ANOTHER DAY RATHER THAN BRINGS ANOTHER SURGE OF MUCH COLDER AIR.
A SPLIT FLOW PATTERN DOMINATES EARLY TO MID NEXT WEEK...PERMITTING A
MUCH COLDER AND DRIER AIR MASS TO SURGE INTO THE EASTERN PLAINS
TUESDAY NIGHT/WEDNESDAY. THIS LOOKS TO BE THE LAST GASP FOR THE
ACTIVE WEATHER AT LEAST FOR THE REST OF NEXT WEEK.
THROUGH EARLY NEXT WEEK...HEAVY SNOW ACCUMULATIONS ARE LIKELY FOR
THE NORTHERN MOUNTAINS. ALTHOUGH SNOW LEVELS ARE FORECAST TO RISE
SUNDAY INTO MONDAY...SOME OF THE HIGHER NORTHERN/WESTERN TERRAIN
WILL CONTINUE TO RECEIVE SNOW...AND SNOW LEVELS OVERALL FALL AGAIN
TUESDAY AS THE UPPER LOW/TROUGH MOVE OVERHEAD AND TO OUR SOUTH.
HIGH TEMPERATURES THROUGH THE MIDDLE OF NEXT WEEK WILL REMAIN BELOW
AVERAGE. VENT RATES WILL BE POOR IN THE EAST SATURDAY AND SUNDAY BUT
GOOD TO EXCELLENT OVER MOST OF THE WEST CENTRAL AND SOUTHWEST DUE TO
INCREASING WINDS AND MIXING HEIGHTS. VENT RATES OVERALL NEXT MONDAY
AND TUESDAY WILL BE EXCELLENT THEN WORSEN SOMEWHAT WEDNESDAY.
EXCELLENT RH RECOVERIES EXPECTED THROUGH THE PERIOD ALTHOUGH MIN RH
VALUES TREND MUCH LOWER WEDNESDAY INTO THURSDAY.
&&
.AVIATION...
18Z TAF CYCLE
MTS OBSCURED IN WDSPRD MVFR TO IFR CIGS/VSBYS IN SNOW AND FOG
ALTHOUGH A MIX OF RAIN AND SNOW POSSIBLE LOWER ELEVATIONS WEST OF
THE CONTDVD BEFORE 28/00Z. SNOW TO INCREASE FROM THE CHUSKA MTS
EAST AND NORTHEAST TO THE SANGRE DE CRISTO MTS AND POSSIBLY AS FAR
SOUTH INTO THE ABQ METRO AFT 28/00Z. UPPER JET TO REMAIN ORIENTED
FROM NW TO SE OVER NEW MEXICO THRU 28/12Z AS SURFACE HIGH PRESSURE
OVER ERN NM BEGINS TO WEAKEN.
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 30 46 33 46 / 80 70 60 60
DULCE........................... 22 37 28 42 / 90 80 80 90
CUBA............................ 24 38 30 45 / 90 70 60 80
GALLUP.......................... 32 47 36 50 / 60 70 70 80
EL MORRO........................ 29 47 35 51 / 50 50 60 70
GRANTS.......................... 27 50 32 54 / 60 40 40 60
QUEMADO......................... 31 50 38 53 / 30 20 40 40
GLENWOOD........................ 37 61 42 62 / 10 30 20 50
CHAMA........................... 19 34 26 40 / 90 80 80 90
LOS ALAMOS...................... 22 37 33 46 / 70 60 60 70
PECOS........................... 15 36 31 44 / 80 50 60 50
CERRO/QUESTA.................... 17 34 27 42 / 90 60 70 70
RED RIVER....................... 17 28 26 37 / 90 70 70 70
ANGEL FIRE...................... 14 33 23 40 / 90 60 70 60
TAOS............................ 20 36 31 45 / 80 60 60 60
MORA............................ 14 37 31 44 / 60 40 60 50
ESPANOLA........................ 22 43 32 52 / 60 40 40 50
SANTA FE........................ 20 39 33 48 / 70 50 50 50
SANTA FE AIRPORT................ 20 41 32 50 / 60 40 50 50
ALBUQUERQUE FOOTHILLS........... 26 48 36 57 / 60 40 40 30
ALBUQUERQUE HEIGHTS............. 27 50 37 60 / 50 30 30 30
ALBUQUERQUE VALLEY.............. 25 52 34 62 / 50 30 30 30
ALBUQUERQUE WEST MESA........... 25 50 36 61 / 60 30 40 40
LOS LUNAS....................... 28 53 36 62 / 30 20 20 20
RIO RANCHO...................... 27 48 36 58 / 60 30 40 40
SOCORRO......................... 31 56 39 64 / 20 10 10 10
SANDIA PARK/CEDAR CREST......... 20 40 34 49 / 60 40 50 40
TIJERAS......................... 24 45 35 55 / 60 40 50 30
MORIARTY/ESTANCIA............... 17 43 31 56 / 60 30 40 20
CLINES CORNERS.................. 15 37 30 48 / 60 30 40 20
GRAN QUIVIRA.................... 21 45 36 55 / 40 20 20 20
CARRIZOZO....................... 28 53 40 60 / 20 10 10 10
RUIDOSO......................... 26 49 36 57 / 30 20 10 10
CAPULIN......................... 10 31 24 33 / 50 30 30 40
RATON........................... 11 33 23 38 / 60 30 40 40
SPRINGER........................ 12 35 24 41 / 60 30 30 30
LAS VEGAS....................... 12 35 29 43 / 60 40 40 30
CLAYTON......................... 11 32 22 30 / 50 20 20 30
ROY............................. 13 31 26 39 / 50 30 30 20
CONCHAS......................... 18 36 29 46 / 40 20 20 20
SANTA ROSA...................... 18 36 30 52 / 40 20 20 10
TUCUMCARI....................... 17 38 30 46 / 30 20 10 10
CLOVIS.......................... 16 39 30 54 / 30 20 10 5
PORTALES........................ 17 41 31 58 / 30 20 10 0
FORT SUMNER..................... 19 40 31 54 / 30 20 10 5
ROSWELL......................... 23 49 34 65 / 30 10 10 0
PICACHO......................... 22 48 33 64 / 30 10 10 0
ELK............................. 23 52 37 63 / 20 10 10 5
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ502>504-516-518-519-521.
WINTER WEATHER ADVISORY UNTIL 8 AM MST SATURDAY FOR THE FOLLOWING
ZONES...NMZ501-505>507-517.
WINTER STORM WARNING UNTIL 4 PM MST SUNDAY FOR THE FOLLOWING
ZONES...NMZ510>515-527.
&&
$$
52
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1104 PM MST THU FEB 26 2015
.AVIATION...
06Z TAF CYCLE
WIDESPREAD IFR TO LIFR CONDITIONS TO CONTINUE FROM CENTRAL MT
CHAIN EAST WITH MT OBSCURATIONS THROUGH MOST THIS 24 HR FCST
PERIOD...BUT SOME SLIGHT IMPROVEMENT IS POSSIBLE IN THE AFTN. ALSO
PATCHES OF -SN TO SN OVERNIGHT WILL BECOME LIGHTER AND MUCH MORE
SPOTTY AFTER DAWN. LVS/TCC WILL BE IMPACTED MOST WITH ROW ALSO
BEING IMPACTED TO SOME DEGREE. FARTHER WEST AREAS OF MVFR AND MORE
LOCALIZED IFR CIGS CAN BE EXPECTED AT LEAST INTO ROUGHLY MID MORN
FRI WITH IMPROVEMENT TO VFR YET SOME PATCHY MVFR WITH OCCASIONAL MT
OBSCURATIONS. GAP WINDS INTO RIO GRANDE VALLEY ALSO TO CONTINUE
THROUGH EARLY MORN FRI THEN DIMINISH TO SOME DEGREE. AWW TO BE
CONTINUED AT ABQ FOR NOW MORE DUE TO SN THAN WIND AS UP TO AN INCH
OR TWO OF SN TO ACCUMULATE THERE THROUGH 08Z...THOUGH SOME WIND
GUSTS STILL MAY APPROACH 30 TO 35 KT RANGE BETWEEN 07Z AND 10Z.
IFR/MVFR CIGS AND OCCASIONALLY VSBY DUE TO SN IS EXPECTED AT
ABQ/SAF/AEG MAINLY THROUGH 08 TO 09Z WITH SOME IMPROVEMENT
THEREAFTER...ESPEC AT ABQ. AEG AND SAF MAY EVEN SEE A FEW PERIODS
OF LIFR CONDITIONS DURING HEAVIER SNOW BURSTS AND THEREAFTER INTO
EARLY TO MID MORN DUE LARGELY TO FOG.
43
&&
.PREV DISCUSSION...731 PM MST THU FEB 26 2015...
.UPDATE...
NAM12 AND HRRR SHOW LARGER SNOW AMOUNTS OVER SOCCORO AND LINCOLN
COUNTY THAN EARLIER ANTICIPATED...AS UPPER JET SAGS FARTHER SOUTH
TONIGHT. LIGHT SNOW AT KONM PRESENTLY...SO DECIDED TO GO AHEAD
WTIH SOME EXPANDED WINTER WEATHER AVISORIES. UPDATED ZFP AND WSW
ALREADY OUT.
43
&&
.PREV DISCUSSION...333 PM MST THU FEB 26 2015...
.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN WILL CONTINUE OVER NORTHERN AND
CENTRAL NEW MEXICO THROUGH THE NEXT SEVERAL DAYS AS NUMEROUS
DISTURBANCES ALOFT BRING PRECIPITATION TO THE STATE. TEMPERATURES
ARE CURRENTLY WELL BELOW AVERAGE...ESPECIALLY IN THE EASTERN
PLAINS OF THE STATE WHERE READINGS ARE SOME 30 DEGREES BELOW
NORMAL FOR LATE FEBRUARY. WITH COLDER AIR IN PLACE...SNOW IS
EXPECTED TO BREAK OUT OVER MUCH OF CENTRAL TO EASTERN NEW MEXICO
TONIGHT INTO FRIDAY AS AN UPPER LEVEL DISTURBANCE APPROACHES.
SEVERAL INCHES OF ADDITIONAL ACCUMULATION ARE EXPECTED BY
TOMORROW...ESPECIALLY IN THE MOUNTAINS AND HIGHLANDS OF NORTHERN
AND CENTRAL NEW MEXICO. AS THE WEEKEND UNFOLDS...ANOTHER POTENT
DISTURBANCE WILL DIVE INTO CALIFORNIA BEFORE SLOWLY SPREADING OVER
NEW MEXICO. A PROLONGED PERIOD OF HIGH ELEVATION SNOW IS EXPECTED
SATURDAY...SUNDAY...AND INTO MONDAY AND TUESDAY. THE HIGHEST SNOW
TOTALS WILL BE FOUND IN THE SAN JUAN OR TUSAS MOUNTAINS NEAR THE
COLORADO BORDER WHERE TWO TO FOUR FEET OF SNOW COULD ACCUMULATE
ABOVE TEN THOUSAND FEET. RAIN WILL FALL IN LOWER ELEVATIONS DURING
THIS WEEKEND TO EARLY NEXT WEEK PERIOD.
&&
.DISCUSSION...
IT HAS BEEN AN EXTREMELY BUSY SHIFT TODAY WITH A FOCUS ON WINTER
HIGHLIGHTS IN NOT ONLY THE NEAR TERM...BUT ALSO FOR THE NEXT
IMPENDING UPPER LOW THAT WILL BEGIN IMPACTING NM THIS WEEKEND.
SOMEWHAT OF A LULL OR RESPITE HAS BEEN OBSERVED THIS AFTERNOON
WITH REGARDS TO SNOW...BUT IT HAS NOT FULLY ENDED IN SOME OF THE
NORTHERN MOUNTAIN LOCALES. THE NEXT UPSTREAM DISTURBANCE IS
LOOKING HEALTHY ON WATER VAPOR SATELLITE IMAGERY...CURRENTLY JUST
WEST OF THE FOUR CORNERS AREA...PERHAPS A BIT FARTHER SOUTH THAN
MODELS HAVE BEEN INDICATING. THIS WILL SPREAD SUFFICIENT DYNAMICS
ALOFT TO SATURATE THE MID LEVELS OF THE ATMOSPHERE WHICH WILL THEN
SEED LOWER LEVELS AND PRODUCE SIGNIFICANT SNOW...ESPECIALLY WHERE
EAST/SOUTHEAST UPSLOPE FLOW WILL BE RUNNING UP ON THE RESPECTIVE
SLOPES OF HIGHER TERRAIN. SANGRES AND CENTRAL MOUNTAINS/HIGHLANDS
APPEAR TO BENEFIT THE MOST FROM THE UPSLOPE WHILE SATURATED MID
LEVEL CLOUD DECKS WILL SEED LOWER LAYERS...INDUCING SNOW GROWTH.
IN ADDITION THE DYNAMICS SHOULD BE ENOUGH TO PRODUCE SIGNIFICANT
SNOWFALL OVER THE HIGHER PEAKS OF THE REMAINING NORTHERN
MOUNTAINS. THE EASTERLY FLOW HAS BEEN ACCELERATING THROUGH
GAPS/CANYONS WITHIN THE CENTRAL MOUNTAIN CHAIN...AND AN EARLY
EVENING SURGE SHOULD ALLOW SPEEDS TO JUMP UP SEVERAL MPH AT KABQ
AND KSAF. THIS SHOULD SHADOW MUCH OF THE ALBUQUERQUE METRO AREA
WITH REGARD TO SNOW...SO HIGHLIGHTS WERE HEDGED ON LOWER SIDE WITH
JUST AN ADVISORY.
AS THIS EVENING`S DISTURBANCE TRACKS INTO TX ON FRIDAY...SNOW WILL
BEGIN TO TAPER OFF TOWARD MID DAY. SOME UPSLOPE WILL CONTINUE
THOUGH...KEEPING THOSE FAVORED AREAS PRECIPITATING AT LIGHT RATES.
SOME OF THE HIGHLIGHTS WILL NEED TO BE CONTINUOUSLY MONITORED TO
DECIDE ON EARLIER EXPIRATION FRIDAY. TEMPERATURES WILL BE EVEN
COLDER IN MOST ZONES ON FRIDAY AS THE SYNOPTIC COLD POOL CONTINUES
SEEPING WESTWARD. THIS WILL PUT MOST ZONES AT 10 TO 40 DEGREES
BELOW NORMAL FRIDAY AFTERNOON. INTERESTINGLY MODELS BREAK OUT NEW
BATCHES OF PRECIPITATION IN THE NORTHWESTERN QUADRANT OF THE STATE
FRIDAY AFTERNOON. WITHOUT THE PRESENCE OF ANY BLATANT PERTURBATION
IMMEDIATELY UPSTREAM...IT APPEARS THE TRIGGER IS SOME DIVERGENCE
ALOFT...ASSOCIATED WITH JET DYNAMICS FAR AHEAD OF THE NEXT TROUGH
DIVING INTO THE GREAT BASIN. HAVE INCREASED POPS SOME TO REFLECT
HIGHER PROBABILITIES IN THE NORTHWESTERN ZONES...BUT MAY NOT HAVE
RAISED ENOUGH.
CONFIDENCE IS HIGHER IN THE ELEVATED PROBABILITIES OVER
NORTHWESTERN TO WEST CENTRAL NM FRIDAY NIGHT AND SATURDAY AS THE
AFOREMENTIONED TROUGH DIVES SOUTHWARD OVER CALIFORNIA AND DEEPENS
INTO A LOW...SHEDDING ENERGY INTO AZ/NM. THIS WILL BRING A
STIFFENING SOUTHWESTERLY FLOW OVER NM THAT WOULD HAVE GOOD
OROGRAPHICS ASSOCIATED WITH IT WHILE ALSO ACTING AS A WARM
ADVECTION CATALYST. HAVE OPTED TO ISSUE WINTER STORM WATCH FOR THE
SAN JUAN/TUSAS AND JEMEZ ZONES STARTING FRIDAY NIGHT AND RUNNING
INTO SUNDAY. QPF AMOUNTS ARE VERY IMPRESSIVE WITH THIS FEATURE
FRIDAY NIGHT THROUGH SUNDAY. CHALLENGES WILL ARISE FROM THE WARM
ADVECTION...INDUCING RISING SNOW LEVELS AND COMPLICATING THE SNOW
RATIOS. AT THIS POINT IT STILL APPEARS 2 TO 4 FEET OF NEW SNOW
WOULD BE REASONABLE IN THIS SCENARIO NEAR THE CO-NM BORDER ABOVE
10KFT. SNOW LEVELS WOULD LIKELY RISE TO NEAR 8000 TO 8500 FEET
SUNDAY...AND WHILE THIS MIGHT SUGGEST A LIMITING OF ACCUMULATIONS
AND IMPACTS...THE HYDROLOGY IMPACTS WILL HAVE TO BE STRONGLY
CONSIDERED. IF HEALTHY RAINFALL OCCURS OVER SOME OF THE SNOW
PACK...IN THE 7000 TO 9000 FT RANGE...SOME SUBSTANTIAL MELT AND
RUNOFF COULD OCCUR. WILL MONITOR THIS SCENARIO CLOSELY THE NEXT
COUPLE OF DAYS.
AS THE CA LOW FINALLY DRAGS NORTHEASTWARD OVER NM MONDAY AND
MONDAY NIGHT...ANOTHER PERTURBATION WILL DROP DOWN ON ITS HEELS
TUESDAY...FOLLOWED BY ANOTHER ON WEDNESDAY. THE WEDNESDAY FEATURE
COULD ALLOW A VERY COLD DOME TO SPILL SOUTHWARD INTO NM...BUT IT
WOULD APPEAR TO BE THE CABOOSE ON THE RECENT STORM TRAIN.
52
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS NEXT SEVERAL DAYS. THE ACTIVE WINTER
WEATHER PATTERN WILL CONTINUE THROUGH MIDDLE OF NEXT AS A SERIES
OF UPPER LEVEL DISTURBANCES CROSS OVER THE STATE. TEMPS AREAWIDE
WILL REMAIN BELOW NORMAL THROUGH WEDNESDAY WITH UNUSUALLY HIGH
HUMIDITY.
GUSTY GAP WINDS WILL CONTINUE ALONG THE CENTRAL MOUNTAINS FOR THE
NEXT 24-48 HOURS. OTHERWISE...ANOTHER ROUND OF WETTING SNOW WILL
DEVELOP AND FAVOR CENTRAL/EASTERN AREAS TONIGHT INTO FRIDAY
MORNING. SNOW SHOWERS SHOULD CONTINUE ACROSS WESTERN/CENTRAL AREAS
FRIDAY AFTERNOON.
WETTING PRECIPITATION WILL THEN BE CONFINED TO OVER NORTHERN AND
WESTERN AREAS THIS WEEKEND. SNOW LEVELS WILL RISE DURING THIS PERIOD
AS THE ATMOSPHERE WARMS. MODELS HAVE BEEN TRENDING TOWARDS MORE OF
AN UPPER LEVEL DRY SLOT IMPACT SOUTH CENTRAL/SOUTHEAST AREAS DURING
THIS SAME PERIOD. TEMPERATURES WILL MODIFY SOME BUT WILL REMAIN
BELOW NORMAL. BREEZY CONDITIONS ARE EXPECTED ACROSS WESTERN/CENTRAL
AREAS ESPECIALLY FAVORING THE HIGH TERRAIN. WINDY CONDITIONS ARE
VERY POSSIBLE ACROSS THE HIGH TERRAIN AS THE FLOW ALOFT INCREASES.
MORE UPPER LEVEL DISTURBANCES FROM THE WEST WILL FOLLOW MONDAY THRU
WEDNESDAY BRINGING MORE RAIN/SNOW SHOWERS TO WESTERN AND CENTRAL
AREAS. EASTERN AREAS SHOULD GET INTO THE ACTION BY MIDWEEK. TEMPS
WILL BE A BIT WARMER IN THE EAST...COOLER IN THE WEST ON MONDAY AND
TUESDAY..THEN COOLING ALL OVER WEDNESDAY.
VENTILATION IS EXPECTED TO LOWER ON FRIDAY DUE TO LOWER MIXING
HEIGHTS AND IMPACTS FROM THE BACK DOOR COLD PUSH. VENTILATION WILL
IMPROVE AS THE WEEKEND PROGRESSES...ESPECIALLY ON SUNDAY. GOOD TO
EXCELLENT VENT RATES ARE EXPECTED EARLY NEXT WEEK AS THE ATMOSPHERE
REMAINS UNSETTLED AND HIGHER TRANSPORT WINDS EXIST.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON MST FRIDAY FOR THE FOLLOWING
ZONES...NMZ504-507-508-520-524>526-530-533>540.
WINTER STORM WARNING UNTIL NOON MST FRIDAY FOR THE FOLLOWING
ZONES...NMZ512>516-527>529-531-532.
WINTER WEATHER ADVISORY UNTIL 5 PM MST FRIDAY FOR THE FOLLOWING
ZONES...NMZ517-519.
WINTER STORM WARNING UNTIL 5 PM MST FRIDAY FOR THE FOLLOWING
ZONES...NMZ510-511-518-521>523.
WINTER STORM WATCH FROM LATE FRIDAY NIGHT THROUGH SUNDAY AFTERNOON
FOR THE FOLLOWING ZONES...NMZ510-511.
&&
$$
AREA FORECAST DISCUSSION
NWS TULSA OK
846 PM CST SAT FEB 28 2015
.DISCUSSION...
IT NOW LOOKS LIKE THE SNOW IS CONFINED TO EXTREME NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS AT THIS HOUR. FREEZING RAIN IS BECOMING MORE
OF AN ISSUE WITH AREAS OF FREEZING RAIN AND SLEET ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS. A SOUTHWESTERLY LOW LEVEL JET OF
AROUND 60 MPH CONTINUES TO CREATE ISENTROPIC LIFT ACROSS THE REGION
THIS EVENING PRODUCING THE AREAS OF FREEZING RAIN AND SLEET. THIS IS
EXPECTED TO PERSIST FOR A GOOD DEAL OF THE NIGHT. HAVE INCREASED ICE
AMOUNTS SOME ACROSS EAST-CENTRAL OKLAHOMA INTO WESTERN ARKANSAS. STILL
BELOW WARNING CRITERIA. THE HRRR SHOWS THE PRECIP TAPERING OFF AROUND 3 AM.
WILL SEE MAINLY FREEZING DRIZZLE ACROSS THE REMAINDER OF NORTHEAST OKLAHOMA.
THE TEMPERATURE HAS RISEN TO FREEZING OR JUST ABOVE ACROSS FAR SOUTHEAST
OKLAHOMA. WILL CONTINUE ADVISORY AS IS FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR OKZ049-OKZ053-
OKZ054-OKZ055-OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
758 AM EST FRI FEB 27 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH
THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF
THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY
NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF
PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 11Z RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING FROM
ARND KUNV SEWRD INTO THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED
SFC TROF. RETURNS SHOULD CONTINUE TO DIMINISH...AS DRIER AIR
WORKS IN. BLEND OF LATEST HRRR AND 4KM NAM INDICATE ANY ACCUMS
AFTER 12Z WILL BE NEGLIGIBLE. SATL IMAGERY SHOWS CLEARING SKIES
ACROSS NORTHWEST PA EARLY THIS AM...AS DRY...ARCTIC AIR MASS
OVERSPREADS THE AREA. EXPECT THIS PARTIAL CLEARING TO PROGRESS
INTO THE EASTERN HALF OF THE STATE LATER THIS MORNING.
UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS
MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL
ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR
THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD
TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER
TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN
THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH
PRESSURE MOVES OVER PENN.
THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO
BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO
0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL
VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO
AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS
ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM
WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F
NOT THERE YET FOR AN ADVISORY.
FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH
DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY
ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR
MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM
THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW
NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F
RANGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL
THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN
U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER
CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC
CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE
SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM
TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER
MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL
SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO
A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH.
THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE
ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER
THE SE U.S.
WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE
LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE
BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW
1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST.
PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI
MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND
WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND
0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS
AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES.
THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS.
ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER
SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY
IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING
DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN
RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES
ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
PATCHY LIGHT SNOW CONTINUES TO QUICKLY ERODE FROM KUNV SEWRD INTO
THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED SFC TROF...AS DRIER
ARCTIC AIR WORKS IN FROM THE WEST.
CLEARING SKIES ACROSS NORTHWEST PA EARLY THIS AM SHOULD FILL BACK
IN WITH COLD POOL STRATOCU MVFR CIGS FOR SEVERAL HOURS THIS
MORNING THROUGH EARLY AFTERNOON...WITH OROGRAPHIC FLOW ALSO
KEEPING LIGHT SNOW AND LOW CIGS/VSBYS IN KJST THROUGH AT LEAST
EARLY AFTERNOON. REMAINDER OF THE AREA WILL BE OR TRANSITION TO
VFR CONDITIONS OVER NEXT FEW HOURS AS ANOMALOUSLY STRONG
1040-1045 MB SFC HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY.
WINDS WILL BE W/NW AT AROUND 10 MPH.
OUTLOOK...
FRI NIGHT AND SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...RXR
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
643 AM EST FRI FEB 27 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH
THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF
THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY
NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF
PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 11Z RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING FROM
ARND KUNV SEWRD INTO THE LOWER SUSQ VALLEY ALONG AXIS OF INVERTED
SFC TROF. RETURNS SHOULD CONTINUE TO DIMINISH...AS DRIER AIR
WORKS IN. BLEND OF LATEST HRRR AND 4KM NAM INDICATE ANY ACCUMS
AFTER 12Z WILL BE NEGLIGIBLE. SATL IMAGERY SHOWS CLEARING SKIES
ACROSS NORTHWEST PA EARLY THIS AM...AS DRY...ARCTIC AIR MASS
OVERSPREADS THE AREA. EXPECT THIS PARTIAL CLEARING TO PROGRESS
INTO THE EASTERN HALF OF THE STATE LATER THIS MORNING.
UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS
MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL
ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR
THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD
TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER
TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN
THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH
PRESSURE MOVES OVER PENN.
THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO
BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO
0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL
VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO
AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS
ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM
WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F
NOT THERE YET FOR AN ADVISORY.
FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH
DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY
ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR
MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM
THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW
NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F
RANGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL
THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN
U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER
CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC
CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE
SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM
TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER
MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL
SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO
A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH.
THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE
ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER
THE SE U.S.
WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE
LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE
BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW
1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST.
PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI
MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND
WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND
0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS
AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES.
THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS.
ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER
SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY
IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING
DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN
RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES
ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
LARGE-SCALE FORCING AHEAD OF A SHORTWAVE OVER THE GREAT LAKES
BRINGING SOME LIGHT SNOW TO PORTIONS OF CENTRAL MTNS EARLY THIS
MORNING. THIS WILL REDUCE VSBYS/CIGS TO MVFR /OCCASIONAL IFR/
PRIMARILY OVER THE WESTERN HIGHER TERRAIN THROUGH 12Z. BRIEF
PERIOD OF MVFR CIGS POSS FURTHER EAST THROUGH 10Z.
ANOTHER PUSH OF ARCTIC AIR ARRIVES IMMEDIATELY BEHIND THE
SHORTWAVE FOR FRI. OROGRAPHIC FLOW WILL KEEP MVFR CONDITIONS IN
WESTERN HIGHER TERRAIN THROUGH MIDDAY...WITH IMPROVING CONDITIONS
IN THE AFTERNOON AS ANOMALOUSLY STRONG 1040-1045 MB SFC HIGH
PRESSURE BUILDS INTO THE COMMONWEALTH FROM THE OHIO VALLEY. VFR
WILL BE THE RULE IN CENTRAL AND EAST. WINDS WILL BE W/NW AT AROUND
10 MPH.
OUTLOOK...
FRI NIGHT AND SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/STEINBUGL
AVIATION...RXR
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
517 AM EST FRI FEB 27 2015
.SYNOPSIS...
A LARGE AREA OF HIGH PRESSURE WILL BUILD ACROSS THE AREA THROUGH
THE FIRST HALF OF THE WEEKEND. A LOW PRES SYSTEM WILL LIFT OUT OF
THE MIDWEST LATE IN THE WEEKEND...PASSING OVER THE REGION SUNDAY
NIGHT. A STRONGER AREA OF LOW PRESSURE WILL LIKELY TRACK WEST OF
PENNSYLVANIA LATE TUESDAY OR EARLY WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR CONTINUES TO SHOW PATCHY LIGHT SNOW FALLING ACROSS THE
CENTRAL AND SC MTNS OF PA AT 09Z IN REGION OF LG SCALE FORCING
AHEAD OF SHORTWAVE OVR THE GRT LKS. NEAR TERM MDL DATA SUGGESTS
THE FOCUS OF THE LGT SNOW WILL REMAIN ALONG WEAK INVERTED SFC TROF
EXTENDING FROM KUNV SE TO KTHV. BLEND OF LATEST HRRR AND 4KM
NAM SUPPORT A FRESH DUSTING ACROSS THIS AREA BTWN 09Z-13Z. SATL
IMAGERY SHOWS CLEARING SKIES ACROSS WESTERN PA EARLY THIS AM...AS
DRY...ARCTIC AIR MASS OVERSPREADS THE AREA. EXPECT THIS PARTIAL
CLEARING PROGRESS INTO THE EASTERN HALF OF THE STATE LATER THIS
MORNING.
UPSTREAM OBS SUGGEST SKIES MAY BECOME MOSUNNY FOR A WHILE THIS
MORNING. HOWEVER...DIURNAL HEATING...COMBINED WITH COLD POOL
ALOFT...SHOULD YIELD A FAIR AMT OF STRATO CU THIS AFTN...ESP OVR
THE ALLEGHENY PLATEAU. GEFS MEAN 925MB TEMPS ARND -15C SHOULD
TRANSLATE TO HIGHS NO BETTER THAN ARND 10F ACROSS THE HIGHER
TERRAIN OF THE ALLEGHENIES...TO THE L/M20S ACROSS THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
CLEARING SKIES...A CALM WIND AND SNOW COVER WILL LIKELY RESULT IN
THE LOWEST TEMPS UNTIL NEXT WINTER TONIGHT AS THE CENTER OF HIGH
PRESSURE MOVES OVER PENN.
THE IDEAL RADIATIONAL COOLING CONDS SHOULD ALLOW READINGS TO
BOTTOM OUT FROM 10-15F BELOW ZERO ACROSS THE WESTERN MTNS...TO
0-5F ABV ZERO ACROSS THE LOWER SUSQ VALLEY. THE COLDEST RURAL
VALLEYS IN NW AND NCENT PENN COULD SEE THE MERCURY SETTLE TO
AROUND -20F AT 11-12Z SATURDAY. SOME LOCATIONS ACROSS THE NW MTNS
ARE LIKELY REACH WCHILL ADVISORY CRITERIA...DESPITE A LIGHT/CALM
WIND. HOWEVER...CONFIDENCE IN WIDESPREAD APPARENT TEMPS BLW -15F
NOT THERE YET FOR AN ADVISORY.
FAIR AND STILL COLD WEATHER EXPECTED SATURDAY...AS SFC HIGH
DRIFTS OVR THE AREA. A FAST-MOVING MID LVL SHORTWAVE IS PROGGED BY
ALL MDLS TO TRACK ACROSS THE AREA LATE IN THE DAY. LOW PWAT AIR
MASS WILL PRECLUDE ANY PRECIP CONCERNS. HOWEVER...CIRRUS MAY DIM
THE SUNSHINE AT TIMES. ENS MEAN 850/925MB TEMPS REMAIN WELL BLW
NORMAL FOR THE DATE...LIKELY SUPPORTING HIGHS ONLY IN THE 20-25F
RANGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A RELATIVELY MILD/ACTIVE SOUTHWEST FLOW ALOFT SHOULD PREVAIL
THROUGH THE PERIOD AS THE PERSISTENT UPPER RIDGE OVER THE WRN
U.S. TEMPORARILY BREAKS DOWN. AN ARCTIC HIGH PRESSURE SYSTEM OVER
CENTRAL PA AT THE START OF THE PERIOD WILL RETREAT INTO ATLANTIC
CANADA BY SUNDAY NIGHT. THE COMBINATION OF SHORTWAVE ENERGY IN THE
SRN STREAM EJECTING FROM A DSW TROUGH AND A DIGGING NRN STREAM
TROUGH MOVING SEWD FROM SOUTH CENTRAL CANADA TOWARD THE UPPER
MIDWEST SEEMS TO DRIVE AN EXPANDING AREA OF WAA TYPE SNOWFALL
SPREADING EASTWARD SUN-MON BEHIND THE SOUTHERLY RETURN FLOW INTO
A RETREATING COLD SECTOR ASSOCD WITH THE DEPARTING ARCTIC HIGH.
THE PCPN SHOULD BE ENHANCED ALONG AN EXPANDING BAROCLINIC ZONE
ACROSS THE CENTRAL AND EASTERN US...AS UPPER RIDGING BUILDS OVER
THE SE U.S.
WHILE THERE APPEARS TO BE LITTLE INDICATION OF A STRONG SURFACE
LOW...MODELS STILL GENERATE 0.25-0.50 INCH QPF AMTS ALONG THE
BAROCLINIC ZONE. THERMAL PROFILES SEEM TO FAVOR SNOW ACROSS THE NW
1/2 OF CENTRAL PA WITH MIXED PTYPES IN THE SOUTH/SOUTHEAST.
PRELIMINARY 24HR SNOW/ICE AMOUNTS WERE DERIVED USING A MULTI
MODEL QPF BLEND WITH PSEUDO INTERNAL BIAS CORRECTION FACTOR AND
WPC WWD. THIS RESULTS IN ADVY LEVEL SNOWFALL OVER THE NW 1/2 AND
0.10 INCH ICE/ZR OVER THE LWR SUSQ VLY. CONFIDENCE IN THE AMTS IS
AVG AT BEST GIVEN UNCERTAINTY IN QPF AND LOW-LEVEL TEMPERATURES.
THE LACK OF A DEFINED SFC CYCLONE ALSO RAISES SOME REG FLAGS.
ANOTHER COLD HP SYSTEM BUILDS INTO THE REGION MON-TUE WITH ANOTHER
SW FLOW WAA MSTR SURGE ALONG BAROCLINIC FRONTAL ZONE LKLY
IMPACTING THE AREA INTO THE MIDDLE OF NEXT WEEK. TIMING
DIFFERENCES ARE EVIDENT WITH THE GFS MORE BULLISH ON PCPN
RETURNING EARLY TUE VS. SLOWER ECMWF (TUE NGT). MIXED PTYPE ISSUES
ARE EXPECTED AGAIN WITH THIS NEXT SYSTEM.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
LARGE-SCALE FORCING AHEAD OF A SHORTWAVE OVER THE GREAT LAKES
BRINGING SOME LIGHT SNOW TO PORTIONS OF CENTRAL MTNS EARLY THIS
MORNING. THIS WILL REDUCE VSBYS/CIGS TO MVFR /OCCASIONAL IFR/
PRIMARILY OVER THE WESTERN HIGHER TERRAIN THROUGH 12Z. BRIEF
PERIOD OF MVFR CIGS POSS FURTHER EAST THROUGH 10Z.
ANOTHER PUSH OF ARCTIC AIR ARRIVES IMMEDIATELY BEHIND THE
SHORTWAVE FOR FRI. OROGRAPHIC FLOW WILL KEEP MVFR CONDITIONS IN
WESTERN HIGHER TERRAIN THROUGH MIDDAY...WITH IMPROVING CONDITIONS
IN THE AFTERNOON AS ANOMALOUSLY STRONG 1040-1045 MB SFC HIGH
PRESSURE BUILDS INTO THE COMMONWEALTH FROM THE OHIO VALLEY. VFR
WILL BE THE RULE IN CENTRAL AND EAST. WINDS WILL BE W/NW AT AROUND
10 MPH.
OUTLOOK...
FRI NIGHT AND SAT...NO SIG WX EXPECTED.
SUN...SNOW LIKELY NW MTNS. MIXED PRECIP POSSIBLE ELSEWHERE.
MON...MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE...MAINLY AM.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
&&
.CLIMATE...
THE COLDEST FEBRUARY ON RECORD IS STILL LOOKING LIKELY. MONTHLY
MEAN TEMPERATURES THROUGH THE 26TH...IPT 18.2...MDT 20.7.
THE CURRENT RECORD COLDEST FEBRUARY..IPT 19.3...MDT 21.4 BOTH SET
IN 1934.
SO FAR...THIS MONTH IS THE THIRD COLDEST EVER AT IPT...AND FOURTH
COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...STEINBUGL
AVIATION...RXR
CLIMATE...
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1154 AM CST FRI FEB 27 2015
.UPDATE...
UPDATED TO INCLUDE THE 18Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION... /ISSUED 1041 AM CST FRI FEB 27 2015/
WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILE TRENDS INDICATE A
SUBTLE MID-LEVEL SHORTWAVE TROUGH LOCATED ACROSS OKLAHOMA LATE
THIS MORNING. THIS IS PRODUCING SOME SNOW NEAR THE TEXAS/OKLAHOMA
PANHANDLE. MEANWHILE...ACROSS THE MID SOUTH SUNNY TO MOSTLY SUNNY
SKIES ARE PREVAILING WITH TEMPERATURES AS OF 10 AM CST IN THE
TEENS ACROSS THE NORTHERN THIRD OF THE MID SOUTH AND 20S ACROSS
THE REMAINDER OF THE FORECAST AREA.
LATEST SHORT TERM MODEL TRENDS INDICATE THIS PRECIPITATION MAY
ENTER PORTIONS OF THE MIDDLE AND LOWER MISSISSIPPI VALLEYS LATER
THIS AFTERNOON INTO TONIGHT. HOWEVER...CONFIDENCE REMAINS LOW
WITH ANY PRECIPITATION ENTERING EXTREME NORTHEAST ARKANSAS.
THUS...WILL REMOVE THE POPS IN FOR LATE AFTERNOON/THIS EVENING
UNTIL TRENDS SUGGEST OTHERWISE.
WILL MAKE SOME ADJUSTMENTS TO SKY COVER AND ANY OTHER ELEMENTS AS
NEEDED TO ACCOUNT FOR CURRENT SHORT TERM TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 714 AM CST FRI FEB 27 2015/
UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR
LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF
THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE
MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS
ALSO HINT AT IT.
SJM
PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/
CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID
MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE
AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM
THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE
SINGLE DIGITS NORTH TO TEENS SOUTH.
TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE
MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL
DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND
THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO
DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO
SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT
CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME
SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH
CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE
MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS
58F.
TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF
MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY
COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM
20-25F.
SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY
LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH
TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN
CHAIRS.
SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE
MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS
THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE
AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH
THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN
CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE
50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL
SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP
CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY.
MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN
GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE
WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN
THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY.
THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY
TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE
MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY
NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND
THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT
WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS
THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS
CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY
WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY
PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S
TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER
THE FRONT HAS GONE THROUGH.
WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH
COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT
WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW
NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK.
SJM
&&
.AVIATION...
18Z TAF CYCLE (27/18Z-28/18Z)
OCCASIONAL MVFR CEILINGS WILL OCCUR AT KMEM UNTIL 19Z...OTHERWISE
VFR CONDITIONS WILL OCCUR AT THE TAF SITES THROUGH THE PERIOD.
WINDS THIS AFTERNOON NE WINDS 10-12 KTS. WINDS TONIGHT NE 8-11
KTS. WINDS SATURDAY MORNING NE-E 7-8 KTS.
JCL
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1041 AM CST FRI FEB 27 2015
.DISCUSSION...WATER VAPOR SATELLITE/WSR-88D VAD WIND PROFILE
TRENDS INDICATE A SUBTLE MID-LEVEL SHORTWAVE TROUGH LOCATED ACROSS
OKLAHOMA LATE THIS MORNING. THIS IS PRODUCING SOME SNOW NEAR THE
TEXAS/OKLAHOMA PANHANDLE. MEANWHILE...ACROSS THE MID SOUTH SUNNY
TO MOSTLY SUNNY SKIES ARE PREVAILING WITH TEMPERATURES AS OF 10 AM
CST IN THE TEENS ACROSS THE NORTHERN THIRD OF THE MID SOUTH AND
20S ACROSS THE REMAINDER OF THE FORECAST AREA.
LATEST SHORT TERM MODEL TRENDS INDICATE THIS PRECIPITATION MAY
ENTER PORTIONS OF THE MIDDLE AND LOWER MISSISSIPPI VALLEYS LATER
THIS AFTERNOON INTO TONIGHT. HOWEVER...CONFIDENCE REMAINS LOW
WITH ANY PRECIPITATION ENTERING EXTREME NORTHEAST ARKANSAS.
THUS...WILL REMOVE THE POPS IN FOR LATE AFTERNOON/THIS EVENING
UNTIL TRENDS SUGGEST OTHERWISE.
WILL MAKE SOME ADJUSTMENTS TO SKY COVER AND ANY OTHER ELEMENTS AS
NEEDED TO ACCOUNT FOR CURRENT SHORT TERM TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 714 AM CST FRI FEB 27 2015/
DISCUSSION...
UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR
LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF
THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE
MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS
ALSO HINT AT IT.
SJM
PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/
CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID
MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE
AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM
THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE
SINGLE DIGITS NORTH TO TEENS SOUTH.
TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE
MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL
DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND
THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO
DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO
SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT
CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME
SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH
CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE
MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS
58F.
TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF
MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY
COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM
20-25F.
SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY
LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH
TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN
CHAIRS.
SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE
MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS
THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE
AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH
THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN
CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE
50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL
SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP
CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY.
MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN
GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE
WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN
THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY.
THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY
TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE
MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY
NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND
THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT
WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS
THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS
CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY
WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY
PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S
TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER
THE FRONT HAS GONE THROUGH.
WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH
COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT
WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW
NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK.
SJM
&&
.AVIATION...
12Z TAF CYCLE
MVFR CIGS WILL LINGER THIS MORNING AT TUP...OTHERWISE THE
TAF SITES WILL BE VFR THROUGH THE PERIOD. NORTH TO NORTHEAST
WINDS IN THE 10-15 KT RANGE WILL DIMINISH TO 6-9 KTS LATE.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1007 AM EST FRI FEB 27 2015
.DISCUSSION...
LIGHT SNOW SHOWERS AND FLURRIES ARE PERSISTING IN SW VA AND NE TN.
THE RAP AND HRRR REFLECTIVITY DEPICTIONS ARE NOT PICKING UP ON THIS
PRECIP...BUT THE RAP AND NAM SOUNDINGS SHOW SOME SHALLOW MOISTURE
THAT EXTENDS INTO THE DENDRITE GROWTH ZONE DUE TO STEEP LAPSE
RATES. THEY SHOW THIS CONTINUING INTO THE AFTERNOON...WITH MOISTURE
DIMINISHING LATE IN THE DAY. SO WILL UPDATE TO EXTEND THE
LOW/SLIGHT CHANCE POP AND MENTION OF FLURRIES INTO THE AFTERNOON.
CLOUD COVER IS ALSO LESS THAN CURRENTLY DEPICTED IN THE GRIDS...SO
WILL ADJUST SKY COVER DOWNWARD TODAY. TEMPERATURES LOOK ON TRACK SO
FAR.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
714 AM CST FRI FEB 27 2015
.DISCUSSION...
UPDATED FORECAST TO ADD A SMALL CHANCE OF LIGHT SNOW ACROSS NE AR
LATER TODAY INTO TONIGHT. LATEST GUIDANCE SUGGESTS THAT SOME OF
THE SNOW OVER THE SOUTHERN PLAINS MAY REACH NW PARTS OF THE
MIDSOUTH. 11Z HRRR INDICATES THIS POSSIBILITY AND MAV MOS POPS
ALSO HINT AT IT.
SJM
&&
PREV DISCUSSION... /ISSUED 418 AM CST FRI FEB 27 2015/
CURRENTLY...ARCTIC HIGH PRESSURE IS SETTLING ACROSS THE MID
MISSISSIPPI VALLEY. STRONG COLD AIR ADVECTION CONTINUES ACROSS THE
AREA WITH SCT-BKN LOW CLOUDS AND A FEW FLURRIES. TEMPS RANGE FROM
THE UPPER TEENS NORTH TO UPPER 20S SOUTH WITH WIND CHILLS IN THE
SINGLE DIGITS NORTH TO TEENS SOUTH.
TODAY...ARCTIC HIGH PRESSURE BEGINS TO SLIDE FROM THE MIDDLE
MISSISSIPPI VALLEY INTO THE OHIO VALLEY. A WEAK UPPER LEVEL
DISTURBANCE WILL GENERATE SOME LIGHT SNOW OVER WRN OKLAHOMA AND
THE RED RIVER VALLEY THIS AFTERNOON BUT THIS AREA IS EXPECTED TO
DISSIPATE AS IT MOVES ACROSS ARKANSAS. WOULD NOT BE SURPRISED TO
SEE A FEW FLAKES ACROSS NE ARKANSAS BUT AT THIS POINT NOT
CONFIDENT ENOUGH TO INTRODUCE INTO THE FORECAST. SHOULD SEE SOME
SUN THIS MORNING FOLLOWED BY AND INCREASE IN MIDDLE AND HIGH
CLOUDS THIS AFTERNOON. EXPECT A VERY COLD DAY WITH HIGHS IN THE
MID 20S NORTH TO MID 30S SOUTH. THE AVERAGE HIGH IN MEMPHIS IS
58F.
TONIGHT...HIGH PRESSURE REMAINS IN CONTROL. EXPECT A GOOD DEAL OF
MID AND HIGH CLOUDINESS SO TEMPS WILL NOT GET RIDICULOUSLY
COLD...JUST VERY COLD. BY MORNING LOW TEMPS WILL RANGE FROM
20-25F.
SATURDAY...ARCTIC HIGH MOVES OFF TO THE MID ATLANTIC AND SLOWLY
LOOSES ITS GRIP ON THE MIDSOUTH. SHOULD SEE AT LEAST SOME SUN WITH
TEMPS CLIMBING INTO THE UPPER 30S TO UPPER 40S. BREAK OUT THE LAWN
CHAIRS.
SATURDAY NIGHT THROUGH MONDAY...AN WEAK UPPER LEVEL DISTURBANCE
MOVING ACROSS OK/MO WILL RESULT IN A SLIGHT CHANCE OF RAIN ACROSS
THE AREA SATURDAY NIGHT...PERHAPS A LITTLE FREEZING RAIN OVER NE
AR. BY SUNDAY A MORE IMPRESSIVE MID LEVEL TROUGH MOVING THROUGH
THE GREAT LAKES WILL PUSH A COLD FRONT INTO THE MIDSOUTH WITH RAIN
CHANCES INCREASING SUNDAY INTO MONDAY. TEMPS WILL WARM INTO THE
50S MOST PLACES AHEAD OF THE FRONT ON SUNDAY. ON MONDAY TEMPS WILL
SLIGHTLY COOLER WITH HIGH PRESSURE BUILDING TO THE NORTH. PRECIP
CHANCE SHOULD TAIL OFF ACROSS THE NORTH ON MONDAY.
MONDAY NIGHT INTO WEDNESDAY...MAJOR DIFFERENCES IN TIMING BETWEEN
GFS AND ECWMF. A MAJOR UPPER LEVEL TROF WILL DEVELOP OVER THE
WESTERN U.S. EARLY IN THE WEEK AND THERE ARE DIFFERENCES BETWEEN
THE MODELS AS TO WHEN IT WILL PUSH INTO THE MIDDLE OF THE COUNTRY.
THE GFS IS MUCH FASTER...PUSHING AN ACTIVE WARM FRONT NORTH EARLY
TUESDAY WITH SURFACE LOW PRESSURE MOVING THROUGH THE MIDDLE
MISSISSIPPI VALLEY THEN A COLD FRONT WILL MOVE THROUGH TUESDAY
NIGHT. THE ECMWF PUSHES THE WARM FRONT THROUGH LATER TUESDAY AND
THE COLD FRONT THROUGH DURING THE DAY ON WEDNESDAY. AT THIS POINT
WILL TAKE THE COMPROMISE APPROACH AND SPREAD FAIRLY HIGH POPS
THROUGH THE PERIOD. AHEAD OF THE COLD FRONT SURFACE DEWPOINTS
CLIMB INTO THE 60S AND THERE ARE INDICATIONS THAT SOME INSTABILITY
WILL BE PRESENT SO WILL NEED TO WATCH THE TUESDAY NIGHT-WEDNESDAY
PERIOD FOR SEVERE POTENTIAL. EXPECT HIGHS IN THE 60S AND SOME 70S
TUESDAY. HIGHS ON WEDNESDAY WILL BE HIGHLY DEPENDENT ON WHETHER
THE FRONT HAS GONE THROUGH.
WEDNESDAY NIGHT THROUGH THURSDAY...PRECIP WRAPPING UP AND MUCH
COLDER. THE GFS HAS A MUCH COLDER BLAST BEHIND THIS SYSTEM BUT
WILL TEMPER THAT GIVEN THE ECMWF SOLUTION. NONETHELESS BELOW
NORMAL TEMPS EXPECTED ONCE AGAIN FOR THE END OF THE WEEK.
SJM
&&
.AVIATION...
12Z TAF CYCLE
MVFR CIGS WILL LINGER THIS MORNING AT TUP...OTHERWISE THE
TAF SITES WILL BE VFR THROUGH THE PERIOD. NORTH TO NORTHEAST
WINDS IN THE 10-15 KT RANGE WILL DIMINISH TO 6-9 KTS LATE.
JAB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1151 AM CST FRI FEB 27 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET
SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO
THE WESTERN PORTION OF THE CWA THIS MORNING...AND THE ISENTROPIC
LIFT WILL SUPPORT LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE
STARTING TO MOVE INLAND. THIS RAIN WILL GRADUALLY BE ON THE INCREASE
DURING THE DAY. A VERY SHARP TEMPERATURE GRADIENT WITH A WARM AIR MASS
FROM HWY 77 EAST AND COLDER WEST OF 77 ASOCIATED TO THIS COLD FRONT.
AS THE COASTAL TROUGH STRENGTHENS THE WINDS SHIFT MORE NORTHERLY LATER
INTO TONIGHT. THIS TROUGH WILL EVENTUALLY BE LIFTED NORTHEAST WITH COLD
AIR MASS FROM THE WEST TAKING CONTROL AND FILTERING IN THROUGH THE AREA.
THE WINDS WILL BEGIN TO SHIFT NORTHWEST CLOSER TO MIDNIGHT AND WESTERLY
INTO SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 1035 AM CST FRI FEB 27 2015/
DISCUSSION...THE COLD AIR CONTINUES TO MOVE SOUTH ACROSS
THE CWA ESPECIALLY TOWARDS THE WESTERN PORTION OF THE CWA.
THIS HAS SHIFTED WINDS MORE NORTHWEST KEEPING TEMPERATURES
COOLER THAN EXPECTED. KEPT A NORTH TO NORTHWEST FLOW ACROSS
THE AREA WITH A SHARP TEMPERATURE GRADIENT FROM WEST TO EAST.
LOWER HIGH TEMPERATURES A FEW DEGREES MORE TOWARDS THE WEST
AND WITH A EASTERLY FLOW DEVELOPING KEPT WARMER TEMPERATURES
IN THE MID 60S. CHANCE OF RAIN REMAINS THE SAME AND THERE ARE
NO OTHER CHANGES DONE TO THE FORECAST AT THIS TIME.
PREV DISCUSSION... /ISSUED 547 AM CST FRI FEB 27 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET
SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO
THE CWA THIS MORNING...AND THE ISENTROPIC LIFT WILL SUPPORT
LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE POSSIBLE LATER IN
THE DAY. LIGHT TO MODERATE NORTHEAST WINDS WILL BECOME VERY LIGHT
THIS EVE...BUT WILL THEN PICK UP AGAIN SLIGHTLY AFTER MIDNIGHT.
CEILINGS SHOULD LOWER TO MVFR BY MID MORNING AND THEN TO IFR LATER
TODAY. THE GUIDANCE VARIES A LITTLE FOR THIS EVENING...WITH THE
GFS KEEPING CEILINGS A CATEGORY HIGHER THAN THE NAM...BUT MVFR IS
THE MIDDLE GROUND FOR NOW.
&&
PREV DISCUSSION... /ISSUED 254 AM CST FRI FEB 27 2015/
SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS
WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE.
SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A
RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE
CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER.
LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT
WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW
POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A
COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A
RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE
LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE
CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR
BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S
AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA.
LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER.
WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL
SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL
CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO
SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT
RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN
END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS
NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND
MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE
START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C
SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES
SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS
HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW
90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED
SOUTHWESTERLIES WILL BE MIXED DOWN.
AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS
THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE
LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES.
THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND
TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH
PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN
TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL
KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH
TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST
BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS
A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF
AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES
EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT
THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS
LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL
OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY
WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77.
MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE
OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET
UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE
SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH
WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING
SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE
SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN
GULF THROUGH SATURDAY AND INTO THE LONG TERM.
SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS
SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A
WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT
ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED
THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH
SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH
CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE
DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL
CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/52
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1035 AM CST FRI FEB 27 2015
.DISCUSSION...THE COLD AIR CONTINUES TO MOVE SOUTH ACROSS
THE CWA ESPECIALLY TOWARDS THE WESTERN PORTION OF THE CWA.
THIS HAS SHIFTED WINDS MORE NORTHWEST KEEPING TEMPERATURES
COOLER THAN EXPECTED. KEPT A NORTH TO NORTHWEST FLOW ACROSS
THE AREA WITH A SHARP TEMPERATURE GRADIENT FROM WEST TO EAST.
LOWER HIGH TEMPERATURES A FEW DEGREES MORE TOWARDS THE WEST
AND WITH A EASTERLY FLOW DEVELOPING KEPT WARMER TEMPERATURES
IN THE MID 60S. CHANCE OF RAIN REMAINS THE SAME AND THERE ARE
NO OTHER CHANGES DONE TO THE FORECAST AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST FRI FEB 27 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...HIGH CLOUDS ARE EXPECTED TO DECREASE AS THE UPPER JET
SHIFTS DOWNSTREAM. COLD AIR BEHIND A COLD FRONT IS FILTERING INTO
THE CWA THIS MORNING...AND THE ISENTROPIC LIFT WILL SUPPORT
LOWERING CEILINGS...WITH LIGHT RAIN AND DRIZZLE POSSIBLE LATER IN
THE DAY. LIGHT TO MODERATE NORTHEAST WINDS WILL BECOME VERY LIGHT
THIS EVE...BUT WILL THEN PICK UP AGAIN SLIGHTLY AFTER MIDNIGHT.
CEILINGS SHOULD LOWER TO MVFR BY MID MORNING AND THEN TO IFR LATER
TODAY. THE GUIDANCE VARIES A LITTLE FOR THIS EVENING...WITH THE
GFS KEEPING CEILINGS A CATEGORY HIGHER THAN THE NAM...BUT MVFR IS
THE MIDDLE GROUND FOR NOW.
&&
PREV DISCUSSION... /ISSUED 254 AM CST FRI FEB 27 2015/
SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS
WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE.
SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A
RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE
CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER.
LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT
WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW
POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A
COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A
RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE
LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE
CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR
BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S
AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA.
LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER.
WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL
SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL
CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO
SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT
RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN
END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS
NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND
MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE
START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C
SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES
SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS
HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW
90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED
SOUTHWESTERLIES WILL BE MIXED DOWN.
AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS
THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE
LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES.
THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND
TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH
PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN
TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL
KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH
TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST
BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS
A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF
AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES
EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT
THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS
LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL
OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY
WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77.
MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE
OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET
UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE
SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH
WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING
SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE
SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN
GULF THROUGH SATURDAY AND INTO THE LONG TERM.
SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS
SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A
WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT
ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED
THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH
SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH
CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE
DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL
CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 63 55 69 64 / 50 40 40 30
BROWNSVILLE 64 53 70 64 / 50 40 30 30
HARLINGEN 56 53 70 63 / 50 40 40 30
MCALLEN 53 48 70 62 / 30 30 20 20
RIO GRANDE CITY 48 46 68 60 / 30 50 30 20
SOUTH PADRE ISLAND 64 56 69 65 / 50 40 40 30
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
67/52
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
254 AM CST FRI FEB 27 2015
.SHORT TERM /NOW THROUGH SATURDAY/...A COLD FRONT IS WORKING ITS
WAY THROUGH THE CWA THIS MORNING...WITHOUT TOO MUCH FANFARE.
SOUTHERN EDGE AND RR QUAD OF AN UPPER JET STREAK RESULTED IN A
RIBBON OF UPPER CLOUDS STILL OVER THE SOUTHEASTERN CORNER OF THE
CWA BUT THAT SHOULD FADE TODAY AS THICKER LOW CLOUDS TAKE OVER.
LOW CLOUDS ARE THICKENING FROM WEST TO EAST. NORTHEAST WINDS THAT
WERE ALREADY IN PLACE ARE RECEIVING SOME REINFORCEMENT AND DEW
POINTS ARE DECREASING BEHIND THE FRONT. LOOKING FOR A
COOL...CLOUDY DAY ACROSS DEEP SOUTH TEXAS AND THE RGV TODAY WITH A
RANGE OF HIGH TEMPS FROM THE UPPER 40S FAR WEST AND NORTH TO THE
LOWER 60S FOR CAMERON AND WILLACY COUNTIES. LIGHT RAIN AND DRIZZLE
CHANCES WILL INCREASE LATER TODAY AND TONIGHT AS THE COOLER AIR
BECOMES ESTABLISHED. LOW TEMPS TONIGHT WILL BE MAINLY IN THE 40S
AND 50S WITH LIGHT WINDS AS HIGH PRESSURE SPREADS OVER THE AREA.
LOOKS LIKE THE HIGH PRESSURE WILL THEN SHIFT EAST IN SHORT ORDER.
WINDS WILL VEER TO EAST BY SATURDAY AND THE RETURN FLOW WILL
SUPPORT HIGH TEMPS IN THE 60S...THOUGH AMPLE CLOUD COVER WILL
CONTINUE AND A MID LEVEL FLOW THAT WILL BACK FROM WEST TO
SOUTHWEST WILL HELP ENSURE THAT OVERRUNNING PERSISTS.
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...OVERRUNNING LIGHT
RAIN CHANCES ACROSS DEEP SOUTH TEXAS AND THE RGV WILL COME TO AN
END SUNDAY AS COASTAL TROUGHING WEAKENS AND A WARM FRONT LIFTS
NORTHWARD. WINDS BECOME SOUTHEASTERLY BY SUNDAY MORNING AND
MOISTURE DECREASES. COLD AIR IS SHUNTED NORTH AND EAST FOR THE
START OF THE WORK WEEK WITH 850MB TEMPERATURES RISING FROM 13C
SUNDAY MORNING TO 22C BY TUESDAY NIGHT. 700MB SOUTHWESTERLIES
SPREAD OVER THE AREA BEGINNING MONDAY NIGHT. WHAT THIS MEANS IS
HIGH TEMPERATURES MONDAY AND TUESDAY WILL BE IN THE 80S WITH LOW
90S OUT WEST WHERE MID LEVEL DRY AIR DUE TO THOSE AFOREMENTIONED
SOUTHWESTERLIES WILL BE MIXED DOWN.
AN UPPER TROF WILL MOVE OVER THE WESTERN CONUS AND FOUR CORNERS
THROUGH TUESDAY. PRESSURE FALLS AHEAD OF THIS FEATURE WILL INDUCE
LEE TROUGHING ACROSS THE ROCKIES SOUTHWARD INTO THE SIERRA MADRES.
THIS WILL HELP RATCHET UP THE SOUTHERLY SURFACE WINDS MONDAY AND
TUESDAY AS WELL. SURFACE LOW PRESSURE WILL HEAD OUT OF THE HIGH
PLAINS TUESDAY AND DRAG A COLD FRONT INTO CENTRAL AND SOUTHERN
TEXAS WEDNESDAY. WIDESPREAD STRATUS ON A 40KT LOW LEVEL JET WILL
KEEP THE AREA MOSTLY CLOUDY THROUGH THE DAY WHICH WILL HOLD HIGH
TEMPERATURES DOWN INTO THE LOW 80S. TIMING DIFFERENCES EXIST
BETWEEN THE GFS/ECMWF CONCERNING THE PASSAGE OF THE FRONT WITH GFS
A LITTLE FASTER BRINGING THE FRONT THROUGH WEDNESDAY AND THE ECMWF
AT WEDNESDAY NIGHT AND THURSDAY. DESPITE THE TIMING DIFFERENCES
EXPECT STRONG NORTHERLY WINDS AND COOLER TEMPERATURES TO ROUND OUT
THE WORK WEEK. AS FAR AS POPS GO ASSOCIATED WITH THE FRONT LOOKS
LIKE CAPPING WILL BE STRONG AND LIMIT MOST PRECIPITATION TO WELL
OFFSHORE. BOTH ECMWF AND GFS HINT AT WEAK COASTAL TROUGHING FRIDAY
WITH A SLIGHT CHANCE FOR LIGHT RAIN ALONG AND EAST OF HWY 77.
&&
.MARINE /NOW THROUGH THROUGH SATURDAY/...STRONG HIGH PRESSURE
OVER THE PLAINS WILL EXTEND SOUTH OVER THE NORTH GULF AND WILL SET
UP MDT TO FRESH EAST NORTHEAST WINDS...BUT PERHAPS OF MORE
SIGNIFICANCE WILL BE THE LONG FETCH ACROSS THE NORTH GULF...WHICH
WILL SUPPORT ELEVATED SEAS DUE TO A SWELL COMPONENT. THE ONGOING
SMALL CRAFT ADVISORY FOR THE GULF WILL THUS PERSIST THROUGH THE
SHORT TERM. WAVE HEIGHTS OF 7 TO 9 FEET WILL PERSIST ON THE OPEN
GULF THROUGH SATURDAY AND INTO THE LONG TERM.
SATURDAY NIGHT THROUGH TUESDAY...MODERATE TO STRONG EAST WINDS
SATURDAY NIGHT WILL WEAKEN AND TURN MORE SOUTHEASTERLY SUNDAY AS A
WARM FRONT MOVES NORTHWARD THROUGH THE COASTAL WATERS. SMALL CRAFT
ADVISORIES WILL BE ONGOING INTO THE LONG TERM AND WILL BE NEED
THROUGH SUNDAY AS SEA HEIGHTS WILL REMAIN AROUND 7 FEET THROUGH
SUNDAY AFTERNOON. WINDS AND SEAS BECOME MORE MODERATE MONDAY WITH
CONDITIONS DETERIORATING MONDAY NIGHT AND TUESDAY AS LOW PRESSURE
DEEPENS TO OUR WEST AND SOUTHEASTERLY WINDS STRENGTHEN. SMALL
CRAFT ADVISORIES WILL BE LIKELY MONDAY NIGHT INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 63 55 69 64 / 30 40 40 30
BROWNSVILLE 63 53 70 64 / 30 40 30 30
HARLINGEN 61 53 70 63 / 40 40 40 30
MCALLEN 56 50 70 62 / 30 30 20 20
RIO GRANDE CITY 51 46 68 60 / 30 50 30 20
SOUTH PADRE ISLAND 63 56 69 65 / 30 40 40 30
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 3 AM CST SATURDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM...54
LONG TERM...55
GRAPHICS/UPPER-AIR...61
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
315 AM EST SUN MAR 01 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS CONVERGENT UPPER LEVEL
FLOW ACROSS THE MID-SECTION OF THE COUNTY AS ONE BRANCH OF THE
NORTHER STREAM DIPS INTO THE UPPER MIDWEST/NORTHERN PLAINS...AND A
SECOND BRANCH DROPS DOWN THE PACIFIC COAST AROUND A LARGE CUTOFF LOW
OVER CALIFORNIA...AND EJECTS OUT OF THE SOUTHWESTERN STATES INTO THE
CENTRAL PLAINS. HIGH LEVEL SOUTHERN STREAM MOISTURE CAN BE SEEN VERY
WELL ON WV IMAGERY MOVING ACROSS CENTRAL MEXICO...THE GULF OF MEXICO
AND OVER THE FL PENINSULA. SOUTH OF THIS SOUTHERN STREAM WE FIND A
LARGE WEST-EAST ORIENTED UPPER RIDGE IN PLACE FROM THE BAY OF
CAMPECHE ACROSS TO THE WESTERN CARIBBEAN. OVER THE NEXT 36-48
HOURS...AS THE WESTERN TROUGH/CUTOFF LOW DIGS FURTHER SOUTH...AND
HEIGHTS FALL ACROSS THE SOUTHWESTERN STATES...THIS WILL FORCE THE
DOWNSTREAM RIDGE TO AMPLIFY NORTHWARD OVER THE GULF OF MEXICO AND
FLORIDA PENINSULA. ALL THIS TRANSLATES INTO A WARM AND SPRING-LIKE
FORECAST FOR OUR REGION DURING THE EARLY AND MIDDLE PORTION OF THE
WEEK.
AT THE SURFACE...STRONG HIGH PRESSURE CONTINUES TO RIDGE DOWN THE
ATLANTIC SEABOARD INTO THE SOUTHEAST CONUS AND WAS THE SET UP FOR
THE OVERRUNNING/UPGLIDE PATTERN THAT BROUGHT ALL THE RAIN TO PARTS
OF THE REGION ON SATURDAY. THE INFLUENCE OF THIS RIDGE IS JUST NOW
BEGINNING TO SLACKEN AS IT WEAKENS AND MOVES OFF INTO THE WESTERN
ATLANTIC. THIS ACTION WILL CONTINUE TO WEAKEN THE THE DEPTH OF
UPGLIDE REGIME AND SLOWLY SHUT DOWN THE SHOWER PRODUCTION THROUGH
THE REMAINDER OF THE EARLY MORNING HOURS. LINGERING UPGLIDE IN THE
LOWEST LEVELS ALONG THE 295-300K SURFACES WILL KEEP THE POTENTIAL
FOR LOWER STRATUS...AND RESULT IN A DIFFICULT AVIATION FORECAST
THROUGH THE MORNING HOURS. HOWEVER...AT LEAST THINGS WILL START TO
DRY OUT...TEMPORARILY.
&&
.SHORT TERM (TODAY THROUGH MONDAY)...
TODAY...
SUNDAY WILL BE A TRANSITION DAY IN THE WEATHER PATTERN FROM ONE
DOMINATED BY THE SURFACE HIGH RIDGING DOWN THE ATLANTIC SEABOARD
INTO OUR REGION...TO ONE COMING UNDER THE INFLUENCE MORE AND MORE
FROM A BUILDING UPPER LEVEL RIDGE OUT OF THE CARIBBEAN. AS MENTIONED
IN THE SYNOPSIS...THE DEEP LAYER UPGLIDE IS SHOWN BY MOST NUMERICAL
GUIDANCE TO HAVE SHIFTED OFF TO THE NORTHEAST BY SUNRISE...HOWEVER A
LOWER LEVEL LAYER OF UPGLIDE WILL STILL BE IN PLACE AND BE HELPING
TO SUPPORT AREAS OF LOWER STRATUS INTO THE MORNING HOURS. THIS WILL
ESPECIALLY BE TRUE ACROSS THE CENTRAL AND NORTHERN PORTIONS OF THE
PENINSULA. FURTHER SOUTH...ON THE OTHER SIDE OF A WEAK BOUNDARY
ACROSS THE STATE...EARLY MORNING SATELLITE IMAGERY IS ALREADY
SHOWING IMPROVING CONDITIONS (IN TERMS OF CLOUD COVER)...AND THIS
SHOULD EXPAND UP INTO OUR SOUTHERN ZONES DURING THE MORNING.
OVER TIME WILL SEE MORE AND MORE SUNNY BREAKS FURTHER NORTH AS
WELL...AND WILL HAVE EVERYONE GOING PARTLY CLOUDY FOR THE AFTERNOON
HOURS. WITH THE SUNNY BREAKS...WE WILL BE SEEING STRONG TERRESTRIAL
HEATING...WITH TEMPS CLIMBING WELL UP INTO THE 70S TO THE NORTH OF
THE I-4 CORRIDOR...AND INTO THE UPPER 70S/LOWER 80S FURTHER SOUTH.
THE LOCAL GRADIENT WILL BE RELAXING OVER TIME AS WELL AS THE SURFACE
RIDGE WEAKENS AND EXITS INTO THE WESTERN ATLANTIC. THIS WEAKENING OF
THE GRADIENT WILL ALLOW A DECENT SEA-BREEZE CIRCULATION TO DEVELOP
AFTER 18Z...AND IN FACT ALL THE HIRES GUIDANCE SHOW THIS TURNING OF
THE WINDS ONSHORE NEAR THE COAST.
WHILE WE EXPECT THE MORNING TO BE MOSTLY DRY ACROSS THE REGION...WE
CAN NOT KEEP THE FORECAST RAIN FREE COMPLETELY FOR THE AFTERNOON AND
EVENING HOURS. A COUPLE OF THINGS COME INTO PLAY HERE. THE FIRST IS
THE STRONG HEATING OVER LAND WILL ALLOW FOR AT LEAST A FEW HUNDRED
J/KG OF BL CAPE THIS AFTERNOON. THE DIFFERENTIAL HEATING ALONG WITH
HELPING TO FORCE THE SEA-BREEZE...IS ALSO SHOWING BY THE GUIDANCE
SUITE TO STRENGTHEN AN INVERTED SURFACE TROUGH ACROSS THE
CENTRAL/WESTERN PORTIONS OF THE PENINSULA FOR THE SECOND HALF OF THE
DAY. THIS TROUGH IS PARTICULARLY PRONOUNCED IN THE NAM/SREF AND
HIRES MEMBERS. THE TROUGH WILL HELP TO FOCUS LOW LEVEL CONVERGENCE
BY MID/LATE AFTERNOON GENERALLY ALONG THE I-75 CORRIDOR. WHEN ONE
ADDS THE EVENTUAL ADDITIONAL FOCUS/CONVERGENCE FROM THE
SEA-BREEZE...IT BECOMES CLEAR THAT UPDRAFTS SUPPORTING LIMITED
CONVECTION CAN NOT BE RULED OUT. IN FACT...THE LAST 4 RUNS OF THE
LOCAL WRFARW...ALONG WITH THE LATEST NCEP HIRES RUNS ARE REMARKABLY
SIMILAR IN THE PATTERN OF ALLOWED CONVECTION DEVELOPING AFTER 19-20Z
ALONG THIS I-75 CORRIDOR. WITH ALL THIS IN MIND HAVE GONE WITH A 30%
POP FOR SCT SHOWERS/ISOLATED THUNDERSTORMS FOR THE LATER AFTERNOON
THROUGH MIDDLE EVENING HOURS. IF THE HIRES RUNS ARE CORRECT...THEN
THE GREATEST THREAT FOR AN AFTERNOON SHOWER WOULD EXIST WITHIN ABOUT
30 MILES EITHER SIDE OF I-75...HOWEVER...HAVE GONE A BIT MORE BROAD
THAN THAT WITH THE FORECAST FOR NOW...AND WILL ALLOW THE DAY SHIFT
TO EVALUATE THE PATTERN EVOLUTION...AND ADD A BIT MORE TEMPORAL
AND/OR SPATIAL DETAIL. THE CONVECTION IS NOT GOING TO BE VERY
ROBUST...AND CERTAINLY NOT EXPECTING ANY STRONG STORMS AT THIS
TIME...HOWEVER A BRIEF DOWNPOUR...AND A FEW LIGHTNING STRIKES SHOULD
BE PLANNED FOR IF OUTDOORS LATER TODAY.
TONIGHT...
WIDELY SCATTERED CONVECTIVE CELLS WILL LINGER INTO THE MIDDLE
EVENING HOURS...MAINLY TO THE NORTH OF THE I-4 CORRIDOR...AND THEN
BEGIN TO DISSIPATE WITH THE LOSS OF DIURNAL HEATING AND RESULTING
LOSS OF SURFACE FOCUS. WILL END ALL SHOWERS BY 03-04Z...WITH A DRY
OVERNIGHT PERIOD THEREAFTER. FOCUS INTO THE LATER OVERNIGHT HOURS
WILL SHIFT TO THE POTENTIAL FOR AREAS OF DENSE FOG DEVELOPMENT. A
MOIST BOUNDARY LAYER WILL STILL BE IN PLACE...AND AS WE START TO SEE
THE UPPER RIDGE BUILD...AND INCREASED LARGE SCALE SUBSIDENCE...THE
SETUP FOR FOG IS FAIRLY GOOD. IN FACT...THE LATEST SREF
PROBABILITIES OF VISIBILITY LESS THAN 1 MILE DURING THE LATE NIGHT
HOURS TONIGHT IS GREATER THAN 80% ACROSS MUCH OF THE REGION. IT HAS
BEEN MY EXPERIENCE TO BEGIN TAKING THE SREF FOG POTENTIAL SERIOUSLY
WHEN PROBABILITIES BEGIN TO EXCEED 70% OR SO. HAVE ADDED AREAS OF
FOG INTO THE GRIDS...AND AGAIN WILL LET THE DAY SHIFT REEVALUATE
BEFORE ADDING DENSE FOG WORDING TO THE FORECAST. FOR NOW...JUST BE
AWARE THAT SOME LOCATIONS MAY HAVE A MORE DIFFICULT MONDAY MORNING
COMMUTE RESULTING FROM VISIBILITY REDUCTIONS. LOW TEMPERATURES EARLY
MONDAY MORNING WILL RANGE FROM THE UPPER 50S OVER LEVY COUNTY...TO
THE LOWER/MIDDLE 60S ELSEWHERE.
MONDAY...
UPPER RIDGE WILL TAKE FIRM CONTROL OVER OUR WEATHER DURING THE DAY.
WILL BE EXPECTING A FAIR AMOUNT OF SUN...AFTER ANY MORNING FOG BURNS
OFF (WHICH MAY TAKE SEVERAL HOURS). FORECASTING ABOVE AVERAGE
TEMPERATURES ACROSS THE REGION AS BOUNDARY LAYER SHOULD BE ABLE TO
EASILY MIX OUT TO THE UPPER 70S ACROSS THE FAR NORTH (LEVY/CITRUS
COUNTIES)...AND LOWER TO MIDDLE 80S FOR MOST OTHER AREAS. THE STRONG
HEATING FORCES ANOTHER SEA-BREEZE TO DEVELOP...AND THIS WILL LIKELY
KEEP TEMPERATURES DOWN A BIT (MID/UPPER 70S) ALONG THE IMMEDIATE
COAST...AS THE FLOW DEVELOPS OFF THE COOLER SHELF WATERS.
HOWEVER...IT WILL NOT TAKE MUCH DISTANCE INLAND TO FIND THE LOWER
80S AGAIN.
THE POTENTIAL FOR A BRIEF AFTERNOON SHOWER ALONG THE SEA-BREEZE IS
NOT ZERO...HOWEVER WITH THE RIDGE BUILDING OVERHEAD...CONDITIONS ARE
NOT AS FAVORABLE AS WE MIGHT SEE THIS AFTERNOON...AND GIVEN THE TIME
OF YEAR...IF THINGS DO NOT LINE UP JUST RIGHT...THEN CONVECTION IS
REALLY NOT THAT LIKELY. FOR NOW WILL KEEP THE FORECAST GENERALLY DRY
MONDAY AFTERNOON. CAN TAKE ANOTHER LOOK AT THIS TONIGHT.
&&
.LONG TERM (TUESDAY THROUGH NEXT SATURDAY)...
THROUGH WED; THE AREA WILL BE DOMINATED BY DEEP LAYER RIDGING THAT
GRADUALLY SLIDES EAST. INITIALLY THE PATTERN ALOFT BEGINS WITH A
LONG WAVE TROUGH FROM CENTRAL CANADA TO THE GREAT BASIN...RIDGING
CENTERED OVER THE YUCATAN THAT REACHED ACROSS THE UPPER GREAT
LAKES...AND ANOTHER TROUGH FROM QUEBEC SOUTH OVER NEW ENGLAND AND
THE CANADIAN MARITIMES TO ATLANTIC WATERS. SURFACE HIGH PRESSURE
CENTERED IN THE OHIO VALLEY...AND SPRAWLING DOWN ACROSS THE GULF
REGION SHIFTS OUT OVER THE OPEN ATLANTIC WHILE RIDGING BACK ACROSS
FL TO THE GULF. THE UPPER RIDGE KEEPS THE ATMOSPHERE STABLE WARM AND
GENERALLY DRY. THE TRACK OF THE SURFACE HIGH WILL VEER WINDS FROM
NORTHEAST AND EAST TO SOUTHEAST AND SOUTHERLY. THE SOUTHERLY WINDS
WILL BRING IN SOME WARM AND MORE HUMID AIR WHICH COULD RESULT IN
SEA FOG AS IT MOVES ACROSS THE COOLER GULF WATERS.
THU-FRI; THE WESTERN LONG WAVE TROUGH...WITH AN ACCOMPANYING COLD
FRONT...BY NOW STRETCHES FROM THE FOUR CORNERS REGION TO THE UPPER
GREAT LAKES. THE TROUGH THEN BEGINS TO SHEAR OUT WITH THE EASTERN
PORTION DE-AMPLIFYING AS IT SHIFTS OFF THE NORTHEAST U.S. COAST
WHILE THE WESTERN END MEANDERS NEAR NORTHERN BAJA CALIFORNIA. THE
GULF UPPER RIDGE FLATTENS AND HANGS ON FROM THE YUCATAN ACROSS CUBA
TO THE ATLANTIC EAST OF THE BAHAMAS. AS A RESULT NEARLY ZONAL FLOW
SETS UP ACROSS THE SOUTHEAST CONUS AND GULF REGION...WITH THE FRONT
GETTING STRUNG OUT FROM WEST TO EAST ON OR NEAR THE GULF COAST. HIGH
PRESSURE BUILDS IN NORTH OF THE FRONT AND TRACKS EAST...WITH NORTH
THEN NORTHEAST WINDS EVENTUALLY BRIDGING THE FRONT AND FILLING IN
ACROSS THE AREA. INCREASING MOISTURE ALONG WITH THE FRONT
APPROACHING FROM THE NORTH WILL SUPPORT SOME SLIGHT CHANCE SHOWERS
AND THUNDERSTORM...INITIALLY ACROSS THE NORTH BUT THAT SPREAD
SOUTHWARD WITH TIME. TEMPERATURES THU RUN ABOVE NORMAL BUT COOL ON
FRI...TO NEAR NORMAL CENTRAL AND SOUTH BUT NEAR TO A BIT BELOW
NORMAL IN THE NORTH WHERE THERE WILL BE MORE RAINFALL AND CLOUDS.
SAT; THE BAJA TROUGH BEGINS WORKING EAST...ALONG THE SOUTHWEST CONUS
OR NORTHWEST MEXICO BORDER REGIONS...WITH FLOW ALOFT STARTING TO
BACK TO WEST-SOUTHWEST. THE FRONT RESIDES ALONG THE GULF COAST IN
THE ECMWF SOLUTION WITH SOMEWHAT DRIER CONDITIONS IN FL OR OVER THE
NORTHERN GULF WATERS AND NORTH FL WITH THE GFS SOLUTION...KEEPING
SLIGHTLY MORE RAINFALL OVER OR NEAR THE AREA. IN EITHER CASE THERE
WILL BE SLIGHT CHANCE TO LOW END CHANCE SHOWERS OR STORMS.
TEMPERATURES CONTINUE NEAR NORMAL CENTRAL AND SOUTH AND JUST UNDER
IN THE NORTH.
&&
.AVIATION...
SO FAR...THE CONDITIONS HAVE NOT BE AS PESSIMISTIC AS THE
STATISTICAL GUIDANCE PREDICTED AT MOST TERMINALS. WILL CONTINUE THIS
TREND FOR THE REMAINDER OF THE OVERNIGHT. ALTHOUGH A FEW PERIODS OF
IFR CIGS ARE CERTAINLY POSSIBLE...THE MAJORITY OF THE TIME SHOULD BE
MVFR AND WILL CHOOSE TO STAY IN THE RANGE OVER THE NEXT SEVERAL
HOURS. PERIODS OF MVFR CIGS SHOULD SLOWLY IMPROVE AFTER SUNRISE AND
BRING ALL TERMINALS BACK TO VFR FOR THE MIDDAY/AFTERNOON/EVENING
HOURS. THERE IS THE POTENTIAL FOR WIDELY SCT SHOWERS AND ISOLATED
STORMS AFTER 19-20Z...LINGERING THROUGH 00-02Z. ANY SHOWERS WILL BE
BRIEF AND HAVE USED VCSH TO HIGHLIGHT THIS POTENTIAL. ANY SHOWERS
DISSIPATED BY LATE EVENING AND FOCUS SHIFTS TO FOG POTENTIAL AFTER
MIDNIGHT. BOTH STATISTICAL AND ENSEMBLE GUIDANCE ARE BEGINNING TO
SUGGEST THE POTENTIAL FOR AREAS OF IFR FOG AFTER 06Z.
&&
.MARINE...
HIGH PRESSURE TO OUR NORTH WILL WEAKEN TODAY ALLOWING THE GRADIENT
TO RELAX AND WIND FIELDS TO WEAKEN. THE GRADIENT WILL RELAX ENOUGH
BY THIS AFTERNOON TO ALLOW SEA BREEZE FORMATION WITH WINDS BECOMING
LIGHT ONSHORE THROUGH THE EARLY EVENING. THE GENERALLY SYNOPTIC
EASTERLY FLOW WILL SHIFT SOUTHEAST ON TUESDAY AND THEN SOUTH BY
WEDNESDAY. EXPECT NEARSHORE WINDS TO BECOME ONSHORE EACH AFTERNOON
AND EARLY EVENING. THERE IS THE POTENTIAL WITH THE MOIST SOUTHERLY
FLOW FOR AREAS OF SEA FOG TO REDUCE VISIBILITY BY LATER TUESDAY OR
WEDNESDAY...AND THIS POTENTIAL WILL NEED TO BE MONITORED CLOSELY. A
COLD FRONT IS SCHEDULED TO ARRIVE LATER THURSDAY OR THURSDAY NIGHT
WHICH WOULD END THE THREAT FOR SEA FOG FOR THE END OF THE WEEK...AND
SHIFT WINDS BACK FROM THE NORTH AND NORTHEAST.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS OUTSIDE OF FOG POTENTIAL ARE
ANTICIPATED OVER THE NEXT SEVERAL DAYS AS RELATIVE HUMIDITY REMAINS
WELL ABOVE CRITICAL LEVELS AND ERC VALUES ARE LOW ACROSS THE REGION.
TEMPERATURES WILL HOWEVER BE ABOVE AVERAGE FOR MUCH OF THE EARLY AND
MIDDLE PORTION OF THE WEEK.
FOG POTENTIAL...
AREAS OF FOG ARE EXPECTED TO DEVELOP TONIGHT INTO EARLY MONDAY
MORNING ACROSS MUCH OF WEST-CENTRAL AND SOUTHWEST FLORIDA. THE FOG
HAS THE POTENTIAL TO BECOME LOCALLY DENSE AT TIME. AREAS OF FOG ARE
ALSO FORECAST FOR LATER MONDAY NIGHT INTO TUESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 65 79 64 / 30 10 10 0
FMY 82 65 83 64 / 30 10 10 0
GIF 80 65 81 63 / 30 20 10 10
SRQ 78 63 79 62 / 20 10 10 0
BKV 80 60 80 59 / 30 20 10 0
SPG 78 65 78 65 / 20 10 10 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT SERVICES...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
455 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
PRE-DAWN...HIGH PRES WEDGED INTO GEORGIA AND THE CAROLINAS EARLY THIS
MORNING WITH A COASTAL TROUGH ALONG THE WEST WALL OF THE GULF STREAM.
AREAS OF LIGHT RAINS HAVE BEEN QUITE TRANSIENT OVERNIGHT AND MAINLY
NORTH OF I-16 BUT A STEADY STREAM OF ISENTROPIC ASCENT SHOULD ENSURE
PERIODIC WET WEATHER FOR MUCH OF THE FORECAST AREA AS ISENTROPIC
ASCENT IS MAINTAINED ACROSS A DEEP THERMAL SURFACE. AT THE GROUND
LEVEL...SURFACE PRESSURES WERE FALLING ACROSS THE AREA...A SIGN
THAT THE STRENGTH OF THE WEDGE HAS PEAKED. CLOUDS WERE LOWERING AS
WARM AIR ADVECTION INCREASES ATOP THE BOUNDARY LAYER. TEMPS WERE
CHILLY ONCE AGAIN WITH READINGS IN THE UPPER 30S INLAND TO LOWER
40S ALONG THE COAST.
WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN
WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST
QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH
HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH
UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS.
EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A
FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING
OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND
SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL
EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS
VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF
NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND
NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO
LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT
THAT SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED
JUST TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH
PLENTY OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE.
RAINFALL AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER
INCH FOR THE MOST PART.
WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT
WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR
DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE
INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS
JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF
FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE
REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC
OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE
STEADY OR RISING LATE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
BOTH AIRFIELDS HAD MVFR CEILINGS AT 09Z...WHICH WILL GRADUALLY
LOWER INTO THE IFR RANGE IN A FEW HOURS...THEN PERSIST THROUGH
THE REMAINDER OF THE VALID CYCLE. THIS IS THE RESULT OF ABUNDANT
MOISTURE TRAPPED BENEATH THE WEDGE INVERSION...AIDED BY ISENTROPIC
LIFT AT VARIOUS LEVELS. PERIODIC LIGHT RAINS OR EVEN DRIZZLE AT
TIMES LIKELY TODAY WITH FOG POTENTIALLY AN ISSUE TONIGHT AS THE
LOW CLOUDS BUILD DOWN WITH STRONG WARM AIR ADVECTION ABOVE THE
COOLER SURFACE TEMPS WITH A DRYING TREND IN THE 3-5 KFT LAYER.
THEE 00Z-06Z MONDAY PORTION OF THE TAFS...CONFIDENCE IS VERY GOOD
THAT LIFR CIGS AND PERHAPS IFR VSBYS WILL PREVAIL GIVEN LATEST
MODEL DATA.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE
MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT.
IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT
GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW
TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT
OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN
ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS
COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE
LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS
LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
257 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1142 PM CST SAT FEB 28 2015
CONDITIONS EXPECTED TO DETERIORATE TO MVFR AND IFR OVERNIGHT INTO
SUNDAY AM IN LOW CLOUDS AND/OR FOG. PATCHY LIFR/VLIFR CONDITIONS IN
FOG WILL BE POSSIBLE. LIGHT SNOW LOOKS TO STAY JUST SOUTH OF BRL
TAF SITE THROUGH SUNDAY AM AND THUS LEFT OUT MENTION THOUGH A FEW
FLURRIES ALSO POSSIBLE AT TIMES AT ALL SITES. ANTICIPATE CIGS LIFTING
TO HIGH MVFR AND EVENTUALLY VFR SUNDAY PM WITH DEVELOPING SOUTHWEST
WINDS AROUND 10 KTS. WINDS WILL SHIFT TO WEST/NORTHWEST LATE PM
INTO EARLY EVE WITH VFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...05
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
350 AM CST SUN MAR 1 2015
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT
WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING.
BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN
ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS
AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 20 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...HOVORKA_42
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS TOPEKA KS
257 AM CST Sun Mar 1 2015
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1125 PM CST SAT FEB 28 2015
WILL SCATTER OUT THE 2 KFT DECK AT THIS TIME AS PREVAILING CIGS
HEIGHT IS GENERALLY BETWEEN 3-4 KFT. WILL KEEP PREVAILING SNOW FOR
LIGHT BAND MOVING OVER TAF SITES BUT HAVE IMPROVED VSBY TO 4SM.
STILL HOLD LOWER CLOUDS TILL AROUND THE NOON HOUR BEFORE STARTING
TO LIFT AND CLEAR OUT LATER IN THE PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...67
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
112 AM CST SUN MAR 1 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CST SAT FEB 28 2015
AS WE REMAIN IN THIS BROAD, CYCLONICALLY-CURVED FLOW PATTERN, WE
WILL CONTINUE TO SEE THE TREND OF MINOR SHORTWAVE PERTURBATIONS
ROTATING ACROSS SOUTHWESTERN KANSAS...PROVIDING US WITH CHANCES FOR
LIGHT PRECIPITATION AS WE SEE SUBTLE DEFORMATION/CONVERGENCE IN THE
LOWER-MID TROPOSPHERE ALONG THE BAROCLINIC ZONE. THE NEXT IN THE
SERIES WILL BE TONIGHT AFTER THE BREAK WE HAD THIS AFTERNOON. POPS
WILL BE INCREASED BACK UP IN TO THE LIKELY CATEGORY WITH A
CONTINUATION OF THE WINTER WEATHER ADVISORY. THE VERY LATEST 18Z
RUNS OF THE NAM12 AND THE HRRR/RAP HAVE THROWN A LITTLE WRINKLE IN
THE NEAR TERM FORECAST. THE NAM12 SUGGESTS THE NEXT LIGHT
PRECIPITATION EVENT WILL START ABOUT 6 HOURS SOONER THAN PREVIOUSLY
THOUGHT (WHICH IS SIGNIFICANT AT THIS CLOSE OF A TIME RANGE) WHEREAS
THE RAP AND HRRR REALLY SHOW NOTHING MUCH AT ALL. IT REALLY IS A
FINE LINE BETWEEN NO PRECIP AT ALL AND LIGHT ACCUMULATING PRECIP IN
THIS FLOW REGIME, AS MUCH DOWNSLOPE AS THERE IS (YET MOIST). THE
SHORT TERM MODELS SHOW A WARMING OF THE 850-750MB LAYER TO THE POINT
THAT A SLIGHT WARM NOSE ABOVE 0C WILL DEVELOP. THIS WILL FAVOR SLEET
AS A PRECIPITATION TYPE LATE TONIGHT, PARTICULARLY SOUTH OF THE
ARKANSAS RIVER. IT SHOULD BE NOTED THAT, AGAIN, ANY PRECIPITATION
TONIGHT WOULD BE QUITE LIGHT AND MAY NOT EVEN HAPPEN AT ALL. THE
INCOMING SWING SHIFT WILL NEED TO WATCH TRENDS TO SEE OF THE WINTER
WX ADVISORY IS STILL NEED THROUGH THE OVERNIGHT HOURS AND IN TO THE
MORNING SUNDAY. TEMPERATURES OVERNIGHT WILL REMAIN QUASI-STEADY
AROUND 20 DEGREES WITH THE CONTINUED SOUTH WINDS AND CLOUDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 214 PM CST SAT FEB 28 2015
A WEAK DISTURBANCE WILL BRING A SLIGHT CHANCE OF LIGHT SNOW
ACROSS FAR WESTERN AND WEST CENTRAL KANSAS SUNDAY NIGHT. LITTLE TO
NO ACCUMULATION IS EXPECTED OVERNIGHT. LOW LEVEL WARM AIR
ADVECTION WILL INCREASE THROUGHOUT THE DAY MONDAY WITH WINDS
SHIFTING TO MORE OF A SOUTHERLY DIRECTION. TEMPERATURES WILL
INCREASE TO ABOVE FREEZING MONDAY INTO MONDAY NIGHT LEADING TO
LIGHT RAIN OR DRIZZLE TO FALL IN SOME LOCATIONS. OTHERWISE EXPECT
MOSTLY CLOUDY SKIES TO CONTINUE. AS FOR TEMPERATURES, LOWS SUNDAY
NIGHT LOOK TO DIP TO AROUND 20 DEGREES WITH HIGHS MONDAY INTO
MONDAY NIGHT REACHING TO THE MID TO UPPER 30S.
MEDIUM RANGE MODELS THEN INDICATE THAT A STRONG UPPER LEVEL
SHORTWAVE WILL MOVE SOUTHEAST OUT OF WESTERN CANADA AND INTO THE
NORTHERN ROCKIES MONDAY NIGHT THEN INTO THE CENTRAL AND NORTHERN
PLAINS TUESDAY. THIS SYSTEM WILL HELP PUSH ANOTHER STRONG COLD
FRONT ACROSS WESTERN KANSAS DURING THE DAY. AS OF NOW FRONTAL
PASSAGE LOOKS TO BE MAINLY DURING THE MORNING HOURS, BUT WITH THIS
SYSTEM BEING 3 DAYS OUT THERE COULD STILL BE SOME CHANGES AS IT
APPROACHES. NEVERTHELESS, STRONG NORTHERLY WINDS ARE ANTICIPATED
BEHIND THIS COLD FRONT WITH CONTINUED MOSTLY CLOUDY SKIES. A
CHANCE OF LIGHT SNOW WILL BE POSSIBLE TUESDAY NIGHT WITH A SLIGHT
CHANCE WEDNESDAY MORNING WITH DECREASING CLOUDINESS EXPECTED
WEDNESDAY AFTERNOON. A WIDE RANGE OF TEMPERATURES ARE ANTICIPATED
TUESDAY DUE TO THE EARLY FRONTAL PASSAGE WITH HIGHS RANGING FROM
THE LOWER 40S ACROSS WEST CENTRAL KANSAS TO MID 50S ACROSS THE
KS/OK BORDER. LOWS LOOK TO FALL INTO THE TEENS TUESDAY NIGHT WITH
HIGHS ONLY REACHING INTO THE MID 20S WEDNESDAY AFTERNOON.
THE REMAINDER OF THE FORECAST LOOKS DRY AS AN UPPER LEVEL RIDGE
BUILDS ACROSS THE WESTERN UNITED STATES. WINDS WILL GENERALLY BE
FROM THE SOUTH TO SOUTHWEST DURING THIS TIME FRAME WITH PARTLY
CLOUDY SKIES. HIGHS ARE FORECASTED TO BE IN THE LOWER 40S THURSDAY
THEN LOWER 50S FRIDAY. LOWS LOOK TO DIP INTO THE LOWER TEENS
WEDNESDAY NIGHT WITH 20S THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INIDCATE A NARROW BAND OF WHAT
WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID MORNING.
BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE MORE OF AN
ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN MVFR STRATUS
AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 20 38 35 / 60 20 20 20
GCK 31 19 40 34 / 30 20 20 10
EHA 33 21 45 38 / 20 30 20 10
LBL 34 22 43 37 / 30 20 10 10
HYS 35 21 39 33 / 30 20 20 20
P28 32 22 39 35 / 60 10 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR KSZ046-064>066-
076>081-086>090.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
343 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
212 AM EST SUN MAR 1 2015
.MESOSCALE DISCUSSION...
ISSUED AT 212 AM EST SUN MAR 1 2015
THE MAIN SURGE OF MOISTURE CONTINUES TO STAY TO THE NORTH AS OF
07Z WITH ONLY LIGHT RETURNS...LIKELY VIRGA...OVER THE BLUEGRASS
REGION. MESONETS IN CENTRAL KY WELL NORTH OF I-64 ARE THE ONLY
LOCATIONS INDICATING MEASURABLE PRECIP. THOUGH AIR TEMPS ACROSS
THE AREA ARE REACHING FREEZING IN THE BLUEGRASS AREAS BUT
ALSO...AS CONCERNING AS THIS IS...IN SOME OF THE DEEPER VALLEYS IN
THE FAR EAST OF EASTERN KENTUCKY...SUCH AS THE PAINTSVILLE MESONET
WHERE A CHILLY 30 DEGREES IS DISPLAYED. AS WELL...MOST DEW POINT
DEPRESSIONS ARE STILL A GOOD 10 DEGREES PLUS IN MANY AREAS. IN
ADDITION...HI RES MODELS SUCH AS THE HRRR SHOW PRECIP HOLDING OFF
UNTIL 10Z AND AFTER. THE GENERAL CONSENSUS HERE IS THAT THE BULK
OF THE MOISTURE WILL STAY NORTH WHILE WHAT RESIDUAL MOISTURE
ADVECTING IN FROM THE SOUTHWEST WILL NOT BE ABLE TO SATURATING THE
LAYER FOR PRECIP TO REACH THE SURFACE. ONCE THIS DOES OCCUR...THE
CURRENT ROAD TEMPS...NOW IN THE MID TO UPPER 30S...WOULD SUGGEST A
SUBSTANTIAL COOL DOWN NEEDED FOR ICE ON ROADWAYS TO DEVELOP. THESE
TEMPS SHOULD HOLD OFF UNTIL AFTER DAWN WHEN TEMPS WARM AGAIN. DUE
TO THE THREAT AND THE FACT THAT 0.01 OF FZRA COULD OCCUR...THIS
STILL NEEDS TO BE A SLIGHT REMINDER SO HAVE REISSUED THE SPS
THROUGH DAWN.
&&
.UPDATE...
ISSUED AT 958 PM EST SAT FEB 28 2015
MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE
ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS.
DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE
SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE
QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO
PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE
A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS
BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT
THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER
WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING
RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND
TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER
TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE
FORECAST AS IS.
UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015
OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING
RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE
HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z
TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY
ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING
RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY
ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS
THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND
DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE
EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A
TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD
AIR GETS SCOURED OUT IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SAT FEB 28 2015
WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING
HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL
BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL
THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL
KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP
INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE
CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT
ICE AND SNOW POTENTIAL.
LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR
GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS...
CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE
ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS
SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3
HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING
BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY
A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL
JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN
A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST
SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM
ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO
15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY
INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE
AFTERNOON...GENERALLY IN THE 40S.
FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE
CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY
NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL
THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER
DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY
MORNING AS HIGH PRESSURE MOVES IN OVERHEAD.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 451 PM EST SAT FEB 28 2015
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A
POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST
FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW
FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND
TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH
WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE
FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING
PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD
AND DRY.
DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER
CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE
STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS
SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY
FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT
RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH
THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS
WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC
OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY
TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS
WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD
THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON
TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL
FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE
HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING
HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK
INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR
THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S
FOR SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE...SHALLENBERGER
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS JACKSON KY
1234 AM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 958 PM EST SAT FEB 28 2015
MADE SOME MORE TWEAKS TO TEMPERATURES. SOME VALLEY LOCATIONS ARE
ALREADY DOWN TO 31 DEGREES WITH SEVERAL MORE RIGHT ON THEIR HEELS.
DO NOT EXPECT TEMPERATURES TO GET TOO MUCH COLDER AS CLOUDS ARE
SPREAD INTO THE REGION AND SHOULD HALT THEIR FALL. HOWEVER...THE
QUESTION CONTINUES...WILL THESE TEMPERATURES COME BACK UP PRIOR TO
PRECIPITATION ONSET LATE TONIGHT. AS IT APPEARS NOW...THIS MAY BE
A STRUGGLE AND THUS...THE FREEZING RAIN THREAT CONTINUES. HRRR HAS
BEGUN TO FLUCTUATE ON PRECIPITATION DEVELOPING AROUND DAWN...BUT
THE LATEST RUN HAS IT BACK IN THERE. WILL HOLD OFF ON ANY WINTER
WEATHER ADVISORY FOR NOW AS STILL NOT CERTAIN HOW MUCH FREEZING
RAIN WILL ACTUALLY OCCUR AND WHETHER IT HAS ANY IMPACT AS GROUND
TEMPERATURES RECOVERED FAIRLY WELL WITH THE SUNSHINE EARLIER
TODAY. OUTSIDE OF SOME TWEAKS TO TEMPERATURES...WILL MAINTAIN THE
FORECAST AS IS.
UPDATE ISSUED AT 715 PM EST SAT FEB 28 2015
OPTED FOR A SPECIAL WEATHER STATEMENT FOR THE FREEZING
RAIN/SLEET/SNOW POTENTIAL LATE TONIGHT. LAST SEVERAL RUNS OF THE
HRRR HAVE SHOWN PRETTY GOOD PRECIPITATION DEVELOPMENT AFTER 09Z
TONIGHT. WITH THE UNCERTAINTY ON WHETHER TEMPERATURES CAN STAY
ABOVE FREEZING...IT CERTAINLY LOOKS LIKE A SETUP FOR SOME FREEZING
RAIN. WITH THE DRY AIR IN PLACE...SOME SLEET MAY BE POSSIBLE EARLY
ON AS WELL. ANY SNOW POTENTIAL WILL LIKELY STAY TO THE NORTH AS
THE WARM NOSE POKES ACROSS THE AREA. TWEAKED TEMPERATURES AND
DEWPOINTS THROUGH THE NIGHT AND RE RAN THE WEATHER TO MATCH THE
EXPECTED TRANSITION ZONES THROUGH DAYBREAK. WE SHOULD SEE A
TRANSITION TO RAIN SHORTLY AFTER DAYBREAK AS ANY REMAINING COLD
AIR GETS SCOURED OUT IN THE VALLEYS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 350 PM EST SAT FEB 28 2015
WINDS WILL SHIFT TO A MORE SRLY DIRECTION ON THE BACKSIDE OF EXITING
HIGH PRESSURE THIS EVENING...CREATING A PSEUDO WARM FRONTAL
BOUNDARY ALONG A DEVELOPING LLVL JET. OVERRUNNING PRECIP WILL
THEN DEVELOP BY THIS EVENING IN NORTHERN PORTIONS OF CENTRAL
KENTUCKY...INTO INDIANA AS WELL AS OHIO. THIS WILL BRING PRECIP
INTO EASTERN KENTUCKY BY OR SHORTLY AFTER 06Z TONIGHT. THERE
CONTINUES TO BE A FEW CONCERNS WITH THIS SYSTEM...NAMELY A LIGHT
ICE AND SNOW POTENTIAL.
LATEST FORECAST SOUNDINGS ARE CONTINUING TO SUPPORT A STEADY OR
GRADUAL WARMING OF TEMPS THROUGHOUT THE NIGHT AS SOUTHERLY WINDS...
CLOUD COVER...AND PRECIP TAKE CONTROL. HOWEVER...GIVEN THE
ANTECEDENT COLD CONDITIONS...IT IS LIKELY THAT EVEN AS SURFACE TEMPS
SLOWLY RISE...THE PAVEMENT AND GROUND TEMPS WILL TAKE AN HOUR TO 3
HOURS LONGER. TEMPERATURES IN THE LLVLS WILL RISE ABOVE FREEZING
BETWEEN 0 AND 6Z...HOWEVER...SURFACE TEMPS WILL LIKELY LAG BEHIND BY
A FEW HOURS. THIS WILL CREATE THE SET UP FOR SOME SNOW/IP POTENTIAL
JUST AT ONSET /AND CONTINUING IN THE NORTH FOR A BIT LONGER/...THEN
A FREEZING RAIN POTENTIAL GIVEN THE LATEST NAM12 AND GFS40 FORECAST
SOUNDINGS THROUGH AROUND 12Z...BEFORE SURFACE TEMPS FINALLY WARM
ENOUGH ACROSS THE REGION THAT ALL PRECIP FALLS AS RAIN AFTER 12Z TO
15Z. GIVEN THE WARMER SRLY FLOW TOMORROW...TEMPS WILL FINALLY
INCREASE TO CLOSER TO SEASONABLE NORMAL VALUES DURING THE
AFTERNOON...GENERALLY IN THE 40S.
FROM HERE...FORECAST SOUNDINGS SHOW A DEEP LAYER OF MOISTURE
CONTINUING THROUGHOUT THE DAY AND INTO THE OVERNIGHT HOURS SUNDAY
NIGHT WITH SOME CONTINUOUS/WIDESPREAD RAINFALL POSSIBLE. RAIN WILL
THEN CHANGE BACK OVER TO SNOW AS TEMPS DROP BELOW FREEZING AFTER
DARK...BEFORE FINALLY LOSING INTENSITY AND TAPERING OFF MONDAY
MORNING AS HIGH PRESSURE MOVES IN OVERHEAD.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 451 PM EST SAT FEB 28 2015
THE MODELS ARE IN GOOD AGREEMENT WITH AN AMPLIFIED LONG WAVE
PATTERN TO RULE ACROSS THE CONUS THROUGH NEXT WEEKEND. A
POSITIVELY TILTED TROUGH OUT WEST WILL RESULT IN DEEP SOUTHWEST
FLOW TO SETTING UP ACROSS THE MISSISSIPPI VALLEY. THIS WILL ALLOW
FOR A STOUT BAROCLINIC ZONE TO MEANDER THROUGH THE OHIO AND
TENNESSEE VALLEYS THROUGH THE MIDDLE OF THE WEEK...WITH MUCH
WARMER AND WETTER AIR BEING ADVECTED INTO THE REGION. THIS WILL BE
FOLLOWED BY ANOTHER SHARP COOL DOWN...WITH ANY LINGERING
PRECIPITATION GOING OVER TO SNOW BEFORE ENDING THE WORK WEEK COLD
AND DRY.
DETAILS ON HOW ALL OF THIS EVOLVES CONTINUES TO BE LOWER
CONFIDENCE UNTIL WE GET A LITTLE CLOSER TO THE EVENT...SO HAVE
STUCK CLOSE TO A BLEND OF THE SOLUTIONS. IN GENERAL...THE MODELS
SEEM TO BE COUPLING THE MOISTURE AND BEST FORCING INITIALLY
FURTHER TO THE NORTHWEST...RESULTING IN NOT QUITE AS SIGNIFICANT
RAINFALL TOTALS ACROSS EASTERN KENTUCKY FROM TUESDAY THROUGH
THURSDAY...WITH GENERALLY 2 TO 3 INCHES FORECAST. STILL...THIS
WILL BE MORE THAN ENOUGH TO CAUSE FLOODING CONCERNS AND WILL
CONTINUE TO HIGHLIGHT THIS THREAT IN AN ONGOING HYDROLOGIC
OUTLOOK.
PRECIPITATION MAY START OUT AS A WINTRY MIX LATE MONDAY INTO EARLY
TUESDAY MORNING...DEPENDING ON HOW QUICKLY IT CAN COOL DOWN AS
WINDS VEER AROUND TO THE SOUTHEAST AND THICKER CLOUDS OVERSPREAD
THE AREA ONCE AGAIN. A SURFACE WARM FRONT WILL LIFT THROUGH ON
TUESDAY...WITH RAINY CONDITIONS MOVING IN. THE COLD FRONT WILL
FOLLOW AND VERY GRADUALLY SLIDE SOUTHEAST THROUGH THE AREA
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...PROVIDING THE BULK OF THE
HEAVIER RAINFALL.
MUCH COLDER AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY BEHIND
THE FRONT...WITH ANY LINGERING PRECIPITATION GOING OVER TO
SNOW...WITH SOME LIGHT ACCUMULATIONS POSSIBLE. AFTER ENJOYING
HIGHS IN THE 50S TUESDAY AND WEDNESDAY...READINGS WILL FALL BACK
INTO THE 20S AND 30S FOR THURSDAY...WITH LOWS BOTTOMING OUT NEAR
THE 10 DEGREE MARK FRIDAY MORNING. HIGHS WILL RETURN TO THE 40S
FOR SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1234 AM EST SUN MAR 1 2015
EXPECT VFR CONDITIONS THROUGH THE FIRST 6 HOURS OF THE TAF PERIOD
BEFORE CIGS FINALLY BEGIN TO LOWER AS MORE MOISTURE ARRIVES INTO
THE AREA WITH PRECIP DEVELOPING BY 10Z IN MOST LOCATIONS. AFTER
THIS TRANSPIRES...PREDOMINATE FIELD MIN CIGS DEVELOP AT JUST
ABOUT EVERY TAF SITE AS A GOOD AREA OF RAIN ARRIVES INTO THE AREA.
EXPECT SOME IFR VISIBILITY AS WELL. THESE CONDITIONS WILL LAST
THROUGH MUCH OF THE REST OF THE TAF PERIOD AND PAST 00Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN
BEFORE THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN
MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS
SHOULD DIE DOWN SUN EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 259 PM EST SAT FEB 28 2015
GOOD AGREEMENT FM THE MODELS ON OVERALL LOOK OF LARGE SCALE PATTERN
THROUGH THE EXTENDED. TROUGH AND COLD AIR THAT HAS DOMINATED FOR
FEBRUARY EASES FIRST PART OF THE WEEK. JUST BEFORE THAT OCCURS THERE
COULD BE SOME LIGHT LAKE EFFECT SNOW SHOWERS SUNDAY NIGHT FOR AREAS
FAVORED BY WNW WINDS. SOUNDINGS INDICATE INVERSIONS UP TO 5KFT WITH
A LOT OF THE MOIST LAYER IN THE DGZ. LACK OF OPEN WATER WILL HAMPER
THE LES...BUT WILL CARRY SCATTERED POPS FOR SNOW BELTS EAST OF MQT
AND P53. LES COULD LINGER AS FLURRIES ON MONDAY MORNING...BUT WILL
OPT FOR DRY FORECAST AS HIGH PRESSURE RIDGE SHOULD BE PUTTING AN END
TO THE LES. WITH A NW LOW-LEVEL FLOW...MODELS HANG ON TO LOW CLOUDS
PROBABLY ENHANCED DUE TO DAYTIME HEATING. MODELS MAY BE OVERDOING
LOW-LEVEL RH THOUGH...SO WILL JUST GO PARTLY CLOUDY FOR DAYTIME ON
MONDAY. HIGHS BOUNCE UP INTO THE 20S...THOUGH WILL REMAIN ONLY TO
AROUND 20 OVER EAST WITH LINGERING NW WINDS OFF ICE OF LK SUPERIOR
MOST OF THE DAY.
CLOUDS THICKEN ON MONDAY NIGHT AHEAD OF DOUBLE BARRELLED LOW
PRESSURE SYSTEM THAT MOVES OVER THE REGION ON TUESDAY. TEMPS MAY
FALL QUICKLY OVER THE EAST CWA ON MONDAY NIGHT...BUT WILL BE IN THE
TEENS ELSEWHERE. ON TUESDAY...NORTHERN STREAM LOW IS THE ONE
AFFECTING ALASKA THIS AFTN AND THE SOUTHERN STREAM LOW IS FORECAST
TO EMERGE OUT OF GENERAL TROUGHING CURRENTLY OVER THE SOUTHWEST
CONUS. H85-H7/H7-H5 Q-VECTOR CONVERGENCE AND MOISTURE ADVECTION
AHEAD OF SFC-H85 TROUGHS WITH H7 MIXING RATIOS 2-3 G/KG SUPPORT
POTENTIAL FOR MODERATE SNOWFALL OVER EAST HALF OF UPR MICHIGAN.
BLEND OF QPF ALONG WITH EXPECTED SLR/S IN THE 13-18:1 RANGE POINT TO
SNOWFALL RANGING FM 2-4 INCHES/3-5 INCHES. KIND OF SEEMS THAT THERE
MAY BE TWO MAIN TIMES OF SNOW WITH THE SYSTEM...LATE MONDAY NIGHT
INTO TUESDAY MORNING...THEN AGAIN TUESDAY AFTN INTO EARLY TUESDAY
EVENING. MODELS ARE LOCKED IN THAT THE TUESDAY AFTN AND TUESDAY
EVENING TIME FRAME WILL FEATURE THE HEAVIEST SNOW...POSSIBLY WITH
SNOWFALL RATES AROUND 1 INCH PER HOUR. IMPACT COULD BE ON THE HIGHER
SIDE TOO AS THE HEAVIEST SNOW COULD FALL DURING THE AFTN AND EVENING
COMMUTE. WILL CONTINUE TO MENTION IN THE HWO AND EHWO GRAPHICS.
REPRIEVE IN THE COLD AIR IS BRIEF AS MORE COLD AIR...CURRENTLY
UPSTREAM OF THE LOW PRESSURE SYSTEM OVER ALASKA...CHARGES IN LATE
TUESDAY NIGHT INTO WEDNESDAY AND LINGERS THROUGH LATE WEEK. RETURN
OF THE COLD WITH H85 TEMPS BLO -20C WILL LEAD TO LAKE EFFECT FOR NW
FLOW AREAS. SOUNDINGS SHOW INVERSIONS START OUT AT 5KFT ON TUESDAY
NIGHT OVER EASTERN LK SUPERIOR BUT RISE UP TO 8KFT ON WEDNESDAY.
EXTENT OF OVER-WATER INSTABILITY AND DEPTH OF THE CONVECTIVE LAYER
SUGGESTS LOCALLY MODERATE SNOW SHOWERS WILL BE POSSIBLE FOR MAINLY
WNW-NW FLOW AREAS. OVERALL THE LOW VSBY WITH SMALLER SNOWFLAKES WILL
BE THE LARGER IMPACT. WINDS 25-30 KTS SO MAY ALSO HAVE BLSN ALONG
THE SHORE...ESPECIALLY IN THE SNOW BELTS EAST OF MQT. WITH ENOUGH
MOISTURE INLAND ON WEDNESDAY...MAY ALSO SEE DIURNALLY ENHANCED SNOW
SHOWERS WITH PERIODS OF GUSTY WINDS/LOWER VSBY. WINDS BACK W-WSW ON
WEDNESDAY NIGHT WHICH WILL END THE LES ALONG MOST OF LK SUPERIOR.
TEMPS INLAND WILL FALL OFF WELL BLO ZERO. WINDS WILL BE ON THE
DECLINE BUT MAY STILL BE STRONG ENOUGH TO PRODUCE NEAR ADVISORY WIND
CHILLS THURSDAY MORNING OVER PARTS OF THE CWA.
HIGH PRESSURE BUILDING OVER THE NORTHERN PLAINS BY THURSDAY SLIDES
TO THE OHIO VALLEY INTO FRIDAY AS LOW PRESSURE SYSTEM CROSSING
NORTHERN ONTARIO PUSHES A WARM FRONT ACROSS THE UPPER GREAT LAKES.
MID-LEVEL MOISTURE H85-H7 AND WEAK LIFT MAY TRIGGER A FEW SNOW
SHOWERS OR FLURRIES THURSDAY NIGHT INTO FRIDAY MORNING. GFS AND
ECMWF BOTH SHOW MAIN FORCING STAYING OVER LK SUPERIOR AND TO THE
NORTH. ANOTHER COLD FRONT WORKS THROUGH ON FRIDAY NIGHT WITH MORE
COLD AIR SETTLING OVER THE AREA BY NEXT SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1152 PM EST SAT FEB 28 2015
A DRY SW FLOW AROUND HIGH PRES SHIFTING TOWARD THE MID ATLANTIC
STATES SHOULD BRING VFR CONDITIONS TO KIWD/KCMX/KSAW THRU THIS FCST
PERIOD. SOME THICKER CLOUDS WILL ARRIVE TONIGHT IN ADVANCE OF AN
APPROACHING LOW PRES TROF...BUT THE LOW-LEVELS SHOULD REMAIN DRY
ENOUGH TO MAINTAIN VFR CIGS EVEN IF THERE IS SOME VERY LIGHT SNOW OR
FLURRIES AT KIWD AND KCMX. GUSTIER W WINDS WILL DEVELOP LATE SUN
MORNING/EARLY AFTN AT KCMX AFTER SFC TROF PASSAGE BUT THEN WIND GUSTS
SHOULD DIE DOWN SUN EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1135 PM CST Sat Feb 28 2015
...AVIATION UPDATE...
.UPDATE...
FREEZING RAIN AND LIGHT SNOW WILL CONTINUE TO IMPACT SOUTH CENTRAL
MISSOURI AFTER MIDNIGHT. ALL OTHER LOCATIONS WILL BE DEALING
MAINLY WITH FREEZING DRIZZLE DEVELOPING AS WE HEAD INTO THE MONDAY
MORNING HOURS.
DUE TO THE FREEZING DRIZZLE CAUSING TRAVEL IMPACTS...THE HEADLINES
WILL REMAIN IN EFFECT FOR NOW.
&&
.SHORT TERM...(This Evening through Sunday Night)
Issued at 307 PM CST SAT FEB 28 2015
A large area of snow has blanketed all of the Missouri Ozarks and
extreme southeastern Kansas as of mid afternoon. Visibilities were
pretty much below one mile over all areas...with occasional
observations indicating quarter mile visibilities with heavy snow.
Snowfall accumulations up through 3 PM have been in the 1-3"
range. We suspect that some locations across extreme southeastern
Kansas and west-central Missouri may be in that 3-4" range.
As we head into late this afternoon and this evening, short term
models are beginning to change their tune a bit. Both the RAP
and the HRRR have somewhat backed off on a secondary band of snow
developing along the I-44 corridor this evening. Even the 18Z NAM
has trended this way. Instead, models gradually take the large
area of moderate to occasionally heavy snow to the east and
northeast with the back edge of the heavier snow moving east
across the Ozarks this evening. This would tend to make sense as
low level isentropic upglide and a weak upper level jet coupling
structure shift towards the Mid Mississippi Valley. We will still
have to watch for some banding of snow as models do indicate some
slugs of increased 700 mb frontogenesis...especially along and
north of the I-44 corridor.
As we head into later tonight, the main area of snow will have
shifted east of the area. Pockets of light snow and flurries
will be left in its wake. While snow intensity will be on the
downward trend this evening (again from west to east), it will
tend to accumulate more efficiently given that the sun will have
set. Models are also indicating perhaps some loss of cloud ice
later tonight. Additionally, models still bring a warm nose into
southern Missouri by late tonight. Thus, we are continuing a
mention of either light freezing rain or freezing drizzle.
This trend will then continue into Sunday morning with pockets of
light snow and drizzle/freezing drizzle. We have slowed the
progress of the surface freezing line to the north by a few
hours...which does keep the door open a bit longer for minor ice
accumulation. One thing we will have to watch very closely is what
will be a good setup for a banded snow event from late tonight
into Sunday morning up towards I-70. Models continue to indicate
strong 700 mb frontogenesis and available negative EPV becoming
juxtaposed with a favorable upper level jet streak. If this
materializes, it could put down a narrow swath of additional
heavier snowfall. While this could glance our central Missouri
counties, confidence is higher that it will remain just north of
the area. Once we get into Sunday afternoon and especially Sunday
night, the primary precipitation will be shifting east and
southeast of the region.
As for storm total ice and snow amounts, we have not changed much.
Any ice accumulations are still expected to remain at or below
five-hundredths of an inch. 1-3" of snow is expected across
south-central Missouri. Accumulations near and north of the I-44
corridor will be in the 3-6" range. We still think a few isolated
reports of around 7" will be possible. Given that any 6-7" amounts
are expected to be isolated (if they occur at all), the current
Winter Weather Advisory will be left intact.
.LONG TERM...(Monday through Saturday)
Issued at 307 PM CST SAT FEB 28 2015
By Monday morning, precipitation should push south of the region,
at least temporarily, as high pressure noses south from the
Dakotas. Highs on Monday look to reach the upper 30s in most
locations.
Precipitation will then return to the area Monday night into
Tuesday, though at this point it appears that temperatures
should be above freezing by the time rain begins to fall Monday
night. Rain will continue through much of the day Tuesday, as low
pressure at the surface deepens and lifts north across Kansas and
northern Missouri. Breezy southwest winds during the day Tuesday
will help temperatures warm into the low to mid 50s. Will continue
to include a mention of thunder in the forecast for Tuesday, with
guidance suggesting a couple hundred J/KG of CAPE making its way
into the CWA.
A strong cold front will then sweep across the area Tuesday
afternoon and evening, with colder air quickly advecting into
the area Tuesday night. We will need to carefully watch the
potential for post frontal snow Tuesday night and Wednesday, as
lift from a secondary trough axis may be enough to result in areas
of snow on Wednesday. As it stands right now, the highest snow
potential for Wednesday looks to be south of I-44, though this
will be highly dependent on the eventual location of the front.
The upper level flow will then flatten out a bit, with
southwesterly flow developing at the surface for the end of the
week into next weekend. This is suggestive of warmer temperatures
for the end of the week, with highs perhaps (finally) approaching
climatological averages by this time next weekend.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS WILL
BE DEALING WITH IFR CEILINGS AND AT LEAST MVFR VISIBILITIES
THROUGH TONIGHT AND MOST OF SUNDAY MORNING.
MOST OF THE HEAVIER SNOW AND FREEZING RAIN HAS SHIFTED INTO SOUTH
CENTRAL MISSOURI. ALL OTHER LOCATIONS WILL BE DEALING WITH
FREEZING DRIZZLE HEADING INTO SUNDAY MORNING.
LOOK FOR WINDS TO BE LIGHT AND VARIABLE.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY until Noon CST Sunday FOR MOZ055-056-066-
067-077-078-088-089-093>098-101>106.
WINTER STORM WARNING until Noon CST Sunday FOR MOZ057-058-
068>071-079>083-090>092.
KS...WINTER WEATHER ADVISORY until Noon CST Sunday FOR KSZ073-097-101.
&&
$$
UPDATE...Schaumann/Cramer
SHORT TERM...Schaumann
LONG TERM...Boxell
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
347 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1110 PM CST SAT FEB 28 2015
A FEW LIGHT SNOW SHOWERS...CURRENTLY OVER NORTHEAST COLORADO...
WILL MAKE THEIR WAY ACROSS SOUTHWEST NEBRASKA. AS THEY COME
ACROSS...CEILINGS OF 2000-3000 FEET AGL AND VISIBILITY AT OR
ABOVE 5SM ARE LIKELY...THOUGH VERY LOCALIZED.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...SPRINGER
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1138 PM CST SAT FEB 28 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
ZONAL FLOW REMAINS IN PLACE ACROSS THE REGION THIS
AFTERNOON...WITH SATELLITE IMAGERY SHOWING THE SHORTWAVE
DISTURBANCE WHICH BROUGHT ACCUMULATING SNOW TO SRN PORTIONS OF THE
CWA CONTINUING TO SLIDE EAST THROUGH THE PLAINS. RADAR TRENDS SHOW
THE BRUNT OF THE SNOWFALL HAS SHIFTED OFF INTO ERN KS/SERN
NEB...WITH JUST SOME LIGHT SNOW/FLURRIES LINGERING ACROSS OUR ERN
COUNTIES. REPORTS RECEIVED FROM PORTIONS OF NC KS HAD TOTALS
TOPPING OUT AROUND 1.5 INCHES. AT THE SFC...THE CWA REMAINS IN
BETWEEN HIGH PRESSURE NOW CENTERED OVER THE NERN CONUS AND LOW
PRESSURE OVER THE HIGH PLAINS...KEEPING THOSE SRLY WINDS IN PLACE.
TEMPS THIS AFTERNOON GOING PRETTY MUCH AS EXPECTED...WITH 3 PM
TEMPS RUNNING THE WHOLE RANGE OF 20S.
WITH THE FIRST WAVE SHIFTING EAST THROUGH THE AREA THIS AFTERNOON
AND THE CWA SITTING IN A BIT OF A LULL...DECIDED TO KEEP THE
EVENING HOURS DRY. DO HAVE POPS RETURNING POST 06Z
TONIGHT...WITH THE POTENTIAL FOR A BIT MORE SNOW AS ANOTHER WEAKER
SHORTWAVE DISTURBANCE AND THE ENTRANCE REGION OF A 140ISH KT UPPER
LEVEL JET STREAK MOVES IN. EVEN THIS CLOSE TO THE POTENTIAL
PRECIP...MODELS DO NO AGREE WITH WHAT THE CWA WILL SEE. 4KM AND
SREF SHOW CHANCES AFFECTING AREAS SOUTH OF I-80...WHILE OTHERS
LIKE THE RAP AND ECMWF SHOW BASICALLY NOTHING. INHERITED FORECAST
INCLUDED SOME CHANCE POPS...AND ONLY MADE MINOR ADJUSTMENTS TO
THOSE. SHOULD SNOW DEVELOP/MOVE INTO THE CWA...ONLY EXPECTING AN
ADDITION FEW TENTHS OF A INCH OF ACCUMULATION.
HAVE LINGERING LOW POPS DURING THE MORNING HOURS TOMORROW...WITH
DRY CONDITIONS FOR THE AFTERNOON. WHILE PLENTY OF CLOUD COVER IS
EXPECTED TONIGHT...WITH TIME TOMORROW SKY COVER SHOULD DIMINISH.
WITH THIS DISTURBANCE MOVING THROUGH LATE TONIGHT/EARLY
TOMORROW...EXPECTING A SWITCH IN WINDS TO THE NORTHWEST
ACCOMPANYING A FRONTAL BOUNDARY. DID BUMP UP HIGHS A FEW
DEGREES...AS MODELS SHOW SLIGHTLY WARMING TEMPS ALOFT WORKING IN
THROUGH THE DAY WITH THOSE NWRLY WINDS /ALTHOUGH THEY ARE ONLY
AROUND 10 MPH/. HIGHS CURRENTLY FORECAST TO REACH INTO THE MID
30S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CST SAT FEB 28 2015
MAIN CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION LATE
SUNDAY NIGHT THROUGH TUESDAY NIGHT AND PRECIPITATION TYPE LATE
MONDAY NIGHT INTO TUESDAY MORNING.
NUMERICAL MODELS AGREE QUITE WELL WITH SYNOPTIC FEATURES. A DEEP
TROUGH IN THE WEST WILL CONTINUE TO APPROACH THE PLAINS FOR THE
FIRST PART OF THE EXTENDED FORECAST. WHILE IN SOUTHWEST
FLOW...THERE COULD BE GENERALLY LOW CHANCES OF PRECIPITATION AS
LOW AMPLITUDE WAVES ARE KICKED OUT OF THE BASE OF THE TROUGH. NOT
UNTIL THE TROUGH MAKES ITS WAY INTO AND EAST OF THE GREAT PLAINS
WILL BE SHUT OFF THE POTENTIAL FOR PRECIPITATION. THE SPECIFICS
AND TIMING ARE FAR FROM AGREED UPON BETWEEN NUMERICAL MODELS.
GENERALLY NEED TO GO WITH LOW CHANCES FOR MOST OF THE FIRST HALF
OF THE LONG TERM FORECAST TO ESSENTIALLY COVER OUR BASES.
CONFIDENCE IS RATHER LOW REGARDING TIMING OF ANY LULLS ALONG WITH
PRECIPITATION AS BOUTS OF SNOW MAY BE RELATIVELY SHORT LIVED. THE
NAM INDICATES ISENTROPIC LIFT FOR MONDAY...GIVING US A SHOT AT
SOME RAIN/SNOW. BOTH THE NAM AND GFS INDICATE CONTINUED ISENTROPIC
LIFT TOWARD LATE MONDAY NIGHT...BUT THE NAM INDICATES A LOSS OF
SATURATION IN THE DENDRITIC GROWTH ZONE...SO THERE COULD BE A
SHORT PERIOD OF FREEZING DRIZZLE BEFORE ISENTROPIC DOWNGLIDE
ENSUES. STILL...THERE IS SO MUCH INCONSISTENCY AND LACK OF
AGREEMENT...I CONTINUE TO BE QUITE SKEPTICAL OF THIS...SO I WILL
PROBABLY CONTINUE TO LEAVE THIS OUT OF THE FORECAST FOR NOW AND
STICK WITH SNOW.
ANOTHER THING TO KEEP AN EYE ON IS WIND SPEED IN COMBINATION WITH
SNOW FALLING FOR TUESDAY BEHIND A COLD FRONT. NORTHWEST WINDS AT
30 MPH GUSTING TO 40 MPH ARE EXPECTED...AND WITH UP TO 2 INCHES
OF SNOWFALL...WE COULD EASILY HAVE REDUCED VISIBILITY.
WIND CHILLS ON WEDNESDAY MORNING DID NOT DIP QUITE LOW ENOUGH TO
MENTION IN THE HWO.
ONCE WE GET THE TROUGH EAST OF US...WE WILL BE MORE CONFIDENTLY
DRY AND EVENTUALLY WARM UP TOWARD NEXT WEEKEND...MAYBE EVEN NEAR
OR ABOVE NORMAL FOR A CHANGE AS A RIDGE IN THE WEST NUDGES EAST.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1138 PM CST SAT FEB 28 2015
VFR CONDITIONS ARE FORECAST THROUGH THE NEXT 24 HOURS...ALTHOUGH
CONDITIONS WILL NEED TO BE MONITORED FOR A PERIODIC MVFR CEILING.
HIGH-LEVEL CLOUDS NEAR 15000FT AGL WILL REMAIN POSSIBLE THROUGH
MUCH OF THE TAF PERIOD. OCCASIONAL STRATUS NEAR 2000FT AGL WILL
ALSO BE POSSIBLE THROUGH THE FIRST HALF OF THE TAF PERIOD...BUT
THE PROBABILITY OF THIS STRATUS MATERIALIZING IS TOO LOW FOR
INCLUSION IN THE TAFS AT THIS TIME. THE SURFACE WIND WILL REMAIN
LIGHT AND VARIABLE TONIGHT BEFORE BECOMING MORE ESTABLISHED FROM
THE NORTHWEST DURING THE DAY SUNDAY. VISIBILITY RESTRICTION IS NOT
EXPECTED AT EITHER TAF SITE THROUGH THE NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADP
LONG TERM...HEINLEIN
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1008 PM PST SAT FEB 28 2015
.SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA
RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS
THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT
WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT
THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE
ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS
POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND
WARMING TREND TAKES PLACE.
&&
.UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL
RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL
MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK
POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT
PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES
NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL
MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE
COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS.
FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A
BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND
EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TOO
AGGRESSIVE SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE
IMAGERY BUT BY THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD
MAKE PROGRESS INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO
ISSUES IN MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS
WELL AS THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY
WHERE SNOW LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000
FEET. AREAS NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH
AS PANACA SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME
MAKING FOR TRICKY TRAVEL.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE
EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS
INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY
ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING
THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS
BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN
OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY
AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A
KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR
ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA
7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY,
EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES
LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER
21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW
LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED
NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED
TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY
PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 230 PM PST SAT FEB 28 2015
.SHORT TERM...THROUGH MONDAY NIGHT.
OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH
OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER
LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF
SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE
AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE
HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL
NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING.
THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE
NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A
BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN
MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND
THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND
CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS
THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND
5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY
MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS
SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3
INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY
WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS
EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD
DECREASE OVERNIGHT.
AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A
PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER
SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY
SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT
VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE
IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO
LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE
A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH
WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY
FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND
HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING
SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A
WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN
MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET
ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT.
WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE
HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY
MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY
HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD
RANGE BETWEEN 4500-5500 FEET.
DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL
FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS
MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR
FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES.
WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE
COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR
EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON
THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING
BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT.
SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION.
ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN.
NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY
NONETHELESS.
AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S
FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO
GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST
METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE!
TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION
WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY.
A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW
PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING
TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY
SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW
THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE
SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC
TROUGH APPROACHES FROM THE WEST.
SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION
AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE
TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER
DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR
CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS
MOVES INTO THE AREA SATURDAY.
NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE
AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND
FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS
REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND
THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO
BE RIGHT AROUND NORMAL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT
ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES
TODAY THROUGH TUESDAY NIGHT.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...PADDOCK/SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
932 PM PST SAT FEB 28 2015
.SYNOPSIS...A STORM SYSTEM CONTINUES TO DROP SOUTH ACROSS CALIFORNIA
RESULTING IN GUSTY WINDS AND SHOWERS ACROSS PORTIONS OF THE AREA. AS
THE STORM DROPS OFF THE COAST OF SOUTHERN CALIFORNIA ON SUNDAY IT
WILL PUSH A BAND OF STEADIER PRECIPITATION INTO THE MOJAVE DESERT
THAT WILL LAST THROUGH SUNDAY NIGHT INTO MONDAY MORNING. ELSEWHERE
ACROSS THE AREA ON SUNDAY SHOWERS ARE POSSIBLE. UNSETTLED WEATHER IS
POSSIBLE ACROSS THE AREA INTO TUESDAY NIGHT BEFORE A DRYING AND
WARMING TREND TAKES PLACE.
&&
.UPDATE...THE LATEST RADAR WAS NOT TOO IMPRESSIVE WITH MEANINGFUL
RETURNS ACROSS THE AREA THIS EVENING. BASED ON THE OPERATIONAL
MODELS AND THE HRRR AS WELL AS RADAR TRENDS, I ELECTED TO TRIM BACK
POPS FURTHER ACROSS THE MOJAVE DESERT FOR THE REST OF THE OVERNIGHT
PERIOD. WHILE THE THREAT OF SHOWERS IN THE SOUTHERN GREAT BASIN DOES
NOT LOOK TO IMPRESSIVE AT THIS TIME, MODELS SHOW ENOUGH MID-LEVEL
MOISTURE AND ENERGY ACROSS THE AREA OVERNIGHT THAT IT CANNOT BE
COMPLETELY DISCOUNTED EITHER AND THUS POPS THERE WERE LEFT AS IS.
FOR THE SUNDAY AFTERNOON-MONDAY EVENT, THINGS STILL LOOK GOOD FOR A
BAND OF STEADIER PRECIPITATION TO IMPACT THE SOUTHEASTERN AND
EVENTUALLY EASTERN THIRD OF THE AREA. THE HRRR APPEARS TO AGGRESSIVE
SPREADING THIS BAND ON BASED ON THE LATEST SATELLITE IMAGERY BUT BY
THE AFTERNOON AND ESPECIALLY EVENING THIS BAND SHOULD MAKE PROGRESS
INTO OUR AREA. A FEW CONCERNS WILL BE POTENTIAL HYDRO ISSUES IN
MOHAVE COUNTY FOR MINOR FLOODING IN POOR DRAINAGE AREAS AS WELL AS
THE NEED FOR WINTER WEATHER HEADLINES IN LINCOLN COUNTY WHERE SNOW
LEVELS ARE EXPECTED TO BE 5500 FEET AND FALL TO 5000 FEET. AREAS
NORTH OF PIOCHE AS WELL AS TOWARD THE UTAH BORDER SUCH AS PANACA
SUMMIT COULD SEE SEVERAL INCHES OF SNOW IN THIS TIME FRAME MAKING
FOR TRICKY TRAVEL.
&&
.AVIATION...FOR MCCARRAN...SOUTH TO SOUTHWEST WINDS AT 8-12 KTS ARE
EXPECTED OVERNIGHT. FEW-SCT CLOUDS AOA 7K FEET WITH CLOUDS
INCREASING OVERNIGHT INTO SUNDAY WITH BASES LOWERING THROUGH THE DAY
ON SUNDAY. THERE IS POTENTIAL FOR A PERIOD OF STEADY RAIN IMPACTING
THE LAS VEGAS VALLEY LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. CIGS
BELOW 5K FEET AND REDUCED VSBY ARE POSSIBLE WITH MOUNTAIN
OBSCURATIONS LIKELY. RAIN SHOULD TAPER OFF TO SHOWERS BY MONDAY
AFTERNOON.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SHOWERS WILL BE AROUND OVERNIGHT MAINLY NORTH OF A
KDAG-KCDC LINE. CIGS AS LOW AS 4K-8K FEET ARE POSSIBLE IN AND NEAR
ANY SHOWERS. OTHERWISE EXPECT DRY CONDITIONS WITH FEW-SCT CLOUDS AOA
7K-10K FEET. WINDS SHOULD FAVOR TYPICAL DIURNAL TRENDS. FOR SUNDAY,
EXPECT WINDS MAINLY 10 KTS OR LESS WITH WINDS FAVORING TYPICAL
DIURNAL DIRECTIONAL TRENDS. CLOUDS SHOULD INCREASE WITH BASES
LOWERING THROUGH THE DAY. STEADIER PRECIPITATION IS EXPECTED AFTER
21Z SUNDAY INTO SUNDAY NIGHT SOUTH OF KDAG-KELY LINE WITH SNOW
LEVELS BETWEEN 5500 AND 6500 FEET. ISO-SCT SHOWERS ARE EXPECTED
NORTHWEST OF THIS LINE. EXPECT CIGS BELOW 5K FEET AND VSBY REDUCED
TO MVFR OR LOWER AT TIMES. MOUNTAIN OBSCURATIONS ARE LIKELY. STEADY
PRECIPITATION SHOULD TAPER TO SHOWERS BETWEEN 12Z AND 18Z ON MONDAY.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 230 PM PST SAT FEB 28 2015
.SHORT TERM...THROUGH MONDAY NIGHT.
OUR MID/UPPER LEVEL LOW PRESSURE SYSTEM IS CURRENTLY TRACKING SOUTH
OVER WESTERN CALIFORNIA. UNDER A DESTABILIZING ATMOSPHERE AND UPPER
LEVEL FORCING...SCATTERED SHOWERS HAVE DEVELOPED ACROSS PORTIONS OF
SOUTHERN NEVADA AND NORTHWEST ARIZONA. THIS ACTIVITY SHOULD CONTINUE
AND MAY INCREASE IN COVERAGE A LITTLE THROUGH THIS EVENING. THERE
HAVE BEEN A FEW LIGHTNING STRIKES OVER SOUTHWEST UTAH AND CENTRAL
NYE COUNTY...WHICH WILL REMAIN POSSIBLE THROUGH THIS EVENING.
THEN...THE LATEST HIRES GUIDANCE CONTINUES TO INDICATE A MORE
NORTHERLY SHIFT LATER THIS EVENING AND COVERAGE DIMINISHING QUITE A
BIT LATE TONIGHT. DID DECREASE POPS...BUT MIGHT NOT BE LOW ENOUGH IN
MANY LOCATIONS IF THE GUIDANCE IS CORRECT. WILL SEE HOW THINGS TREND
THROUGH THE EVENING HOURS. DID INCREASE POPS ACROSS ESMERALDA AND
CENTRAL NYE OVERNIGHT AS THE FORCING AND PRECIP APPEARS TO FOCUS
THERE AS THE UPPER LOW SHIFTS SOUTH. SNOW LEVELS ARE AROUND
5500-6500 FEET AND ARE EXPECTED TO DROP TO 4500-5500 FEET BY SUNDAY
MORNING ACROSS OUR NORTH. ANY PRECIP ACROSS OUR NORTH WOULD FALL AS
SNOW AROUND 5000-5500 FEET AND ACCUMULATE GENERALLY 1-3
INCHES...LOCALLY HIGHER ABOVE 7000 FEET. FARTHER SOUTH WE FIND GUSTY
WEST-SOUTHWEST WINDS THIS AFTERNOON...WHICH WILL LAST INTO THIS
EVENING. THE WIND ADVISORY REMAINS IN EFFECT. WIND SPEEDS SHOULD
DECREASE OVERNIGHT.
AS THE LOW CONTINUES TO DROP SOUTH...IT WILL PIVOT AND TAP INTO A
PLUME OF SUBTROPICAL MOISTURE AND DIRECT IT NORTH ACROSS THE LOWER
SOUTHERN CALIFORNIA DESERTS AND TOWARD THE COLORADO RIVER VALLEY
SUNDAY MORNING INTO SUNDAY NIGHT. LATEST OPERATIONAL MODELS HAVE NOT
VARIED TOO MUCH FROM LAST NIGHTS MODEL RUNS. THE PLUME OF MOISTURE
IS FOCUSED ON MOHAVE COUNTY WITH THE WESTERN EDGES EXTENDING INTO
LINCOLN...CLARK...AND SAN BERNARDINO COUNTIES. BELIEVE THERE WILL BE
A SHARP CUTOFF OF THE HEAVIER PRECIP ON THE WESTERN SIDE...WHICH
WILL LIKELY HAVE TO BE FINE-TUNED WHEN THE PRECIP BAND FINALLY
FORMS. FARTHER WEST WOULD SEE MORE SHOWERY ACTIVITY. SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT WOULD BE THE BEST CHANCE OF RAIN AND
HIGH ELEVATION SNOW...SO DID NOT MAKE MANY CHANGES TO THE RUNNING
SUNDAY-SUNDAY NIGHT FORECAST. WITH THE PRECIP ORIGINATING FROM A
WARM SOURCE REGION...SNOW LEVELS WILL BE RATHER HIGH ACROSS SOUTHERN
MOHAVE COUNTY /GREATER THAN 6500 FEET/ WITH LEVELS OF 5500-6500 FEET
ANTICIPATED IN NORTHERN MOHAVE COUNTY SUNDAY THROUGH SUNDAY NIGHT.
WILL HAVE TO KEEP AN EYE ON POTENTIAL SNOW ACCUMULATIONS ACROSS THE
HIGHER ELEVATIONS OF NORTHERN MOHAVE COUNTY SUNDAY NIGHT INTO MONDAY
MORNING WITH THAT MOISTURE TAP...BUT RIGHT NOW NOT LOOKING LIKE ANY
HEADLINES ARE NEEDED. WEST OF MOHAVE COUNTY...SNOW LEVELS SHOULD
RANGE BETWEEN 4500-5500 FEET.
DID INCREASE QPF ACROSS MOHAVE COUNTY SOME MORE...WITH THE POTENTIAL
FOR OVER AN INCH OF LIQUID PRECIPITATION SUNDAY THROUGH MONDAY. AS
MENTIONED IN THE PREVIOUS DISCUSSION...THIS MAY RESULT IN MINOR
FLOODING IN POOR DRAINAGE AREAS AS WELL AS RAPID RISES IN WASHES.
WHILE THE MAIN PLUME OF MOISTURE CONTINUES TO TAKE AIM ON MOHAVE
COUNTY...CANNOT RULE OUT ADDITIONAL SHIFTS EITHER WEST OR EAST. FOR
EXAMPLE...THE 18Z NAM CAME IN A LITTLE FARTHER WEST. NOT SOLD ON
THIS SOLUTION THOUGH AS THE 18Z RUN YESTERDAY DID THE SAME THING
BEFORE TRENDING THE PLUME BACK OVER MOHAVE COUNTY LAST NIGHT.
SO...PLEASE KEEP UP TO DATE WITH THE LATEST FORECAST INFORMATION.
ALSO FOR MONDAY...WEST-SOUTHWEST WINDS WILL BECOME GUSTY ONCE AGAIN.
NOT LOOKING AT WIND ADVISORY LEVEL WINDS AT THIS TIME BUT GUSTY
NONETHELESS.
AS FOR TEMPERATURES...THE LAS VEGAS VALLEY HAS REACHED THE LOWER 60S
FOR MANY LOCATIONS AS OF THIS WRITING. THIS SHOULD ALLOW FEBRUARY TO
GO DOWN AS THE WARMEST ON RECORD AS WELL AS THE WARMEST
METEOROLOGICAL WINTER ON RECORD FOR LAS VEGAS. QUITE IMPRESSIVE!
TOMORROW SHOULD BE A FEW DEGREES COOLER ACROSS THE ENTIRE REGION
WITH SIMILAR TEMPERATURES EXPECTED TO CONTINUE MONDAY.
.LONG TERM...TUESDAY THROUGH SATURDAY.
A QUICK OVERVIEW OF THE EXTENDED: MODELS FORECAST AN AREA OF LOW
PRESSURE ALONG THE SOUTHERN CAL COAST EARLY TUESDAY MORNING MOVING
TO NORTHERN BAJA BY WEDNESDAY MORNING. ADDITIONAL SHORTWAVE ENERGY
SLIDES DOWN ALONG THE WEST COAST WEDNESDAY AND MERGES WITH THE LOW
THURSDAY AND NUDGES IT EASTWARD. HIGH PRESSURE BUILDS OVER THE
SOUTHWEST FRIDAY AND IS THEN PUSHED EAST SATURDAY AS A PACIFIC
TROUGH APPROACHES FROM THE WEST.
SHOWER ACTIVITY COULD LINGER THROUGH TUESDAY BUT ANY PRECIPITATION
AMOUNTS WILL BE LIGHT. SKIES WILL BEGIN TO CLEAR...ESPECIALLY LATE
TUESDAY WITH A BATCH OF HIGH CLOUDS POSSIBLE WEDNESDAY AS AN UPPER
DISTURBANCE MOVES SOUTH ALONG THE COAST. DRY AND MAINLY CLEAR
CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY BEFORE MORE HIGH CLOUDS
MOVES INTO THE AREA SATURDAY.
NORTH WINDS ARE EXPECTED TUESDAY AND WEDNESDAY ACROSS MUCH OF THE
AREA THEN LINGERING ALONG THE COLORADO RIVER VALLEY THURSDAY AND
FRIDAY. COOL CONDITIONS WILL LINGER THROUGH WEDNESDAY...WITH TEMPS
REMAINING 8-10 DEGREES BELOW NORMAL FOLLOWED BY A WARMING TREND
THROUGH THE REST OF THE WEEK. TEMPERATURES BY FRIDAY ARE EXPECTED TO
BE RIGHT AROUND NORMAL.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE REQUESTED TO REPORT
ANY SIGNIFICANT WEATHER ACCORDING TO STANDARD OPERATING PROCEDURES
TODAY THROUGH TUESDAY NIGHT.
&&
$$
UPDATE/AVIATION...STACHELSKI
PREVIOUS...PADDOCK/SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS TULSA OK
1139 PM CST SAT FEB 28 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
WIDESPREAD IFR TO LIFR CONDITIONS ARE EXPECTED THROUGH SUNDAY
MORNING ALONG WITH AREAS OF FREEZING DRIZZLE OR LIGHT FREEZING
RAIN. SOME SLOW IMPROVEMENT WILL OCCUR SUNDAY AFTERNOON AND
EVENING WITH ALL SITES BECOMING MVFR BY SUNDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 846 PM CST SAT FEB 28 2015/
DISCUSSION...
IT NOW LOOKS LIKE THE SNOW IS CONFINED TO EXTREME NORTHEAST OKLAHOMA
AND FAR NORTHWEST ARKANSAS AT THIS HOUR. FREEZING RAIN IS BECOMING MORE
OF AN ISSUE WITH AREAS OF FREEZING RAIN AND SLEET ACROSS SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS. A SOUTHWESTERLY LOW LEVEL JET OF
AROUND 60 MPH CONTINUES TO CREATE ISENTROPIC LIFT ACROSS THE REGION
THIS EVENING PRODUCING THE AREAS OF FREEZING RAIN AND SLEET. THIS IS
EXPECTED TO PERSIST FOR A GOOD DEAL OF THE NIGHT. HAVE INCREASED ICE
AMOUNTS SOME ACROSS EAST-CENTRAL OKLAHOMA INTO WESTERN ARKANSAS. STILL
BELOW WARNING CRITERIA. THE HRRR SHOWS THE PRECIP TAPERING OFF AROUND 3 AM.
WILL SEE MAINLY FREEZING DRIZZLE ACROSS THE REMAINDER OF NORTHEAST OKLAHOMA.
THE TEMPERATURE HAS RISEN TO FREEZING OR JUST ABOVE ACROSS FAR SOUTHEAST
OKLAHOMA. WILL CONTINUE ADVISORY AS IS FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR OKZ049-OKZ053-
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 WEATHER ADVISORY UNTIL 6 AM SUNDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS PUEBLO CO
414 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM MST SUN MAR 1 2015
RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS
MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS.
THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS
VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT
THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME
FLURRIES.
AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR
LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO
MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND
TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE
CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL
INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL
STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING
BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED
TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE
STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO
VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS.
THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN
PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN
THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST
OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL
POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS
AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25
CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS
HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN
SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR
THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS
MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS
AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR
EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES
AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE
FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING...
BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN
OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE
LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP
SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE
A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING
COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR
A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES...
THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN
IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE
SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT
FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM MST SUN MAR 1 2015
...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND
WARMER WEATHER THEREAFTER...
MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS
THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A
STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS
SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER
PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS
ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL
OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY
MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON
AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING
MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS.
CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH
THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY
MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL
EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE
SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST
TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW
ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL
BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY
CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND
KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S.
TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS
THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY
AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES
AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT
ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN
COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED
BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME
SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT
TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT
AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS
ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES
WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS
AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST
FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON
AND EVENING.
THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL
RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN.
LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN
THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF
STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT
SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT
CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 414 AM MST SUN MAR 1 2015
KCOS WL HAVE IFR OR MVFR CONDITIONS THRU ABOUT 16Z WITH LOW CLOUDS
AND FOG REMAINING IN THE AREA. VFR CONDITIONS ARE THEN EXPECTED
THRU ABOUT MID AFTERNOON. IN THE LATE AFTERNOON HOURS...SNOW IS
EXPECTED TO MOVE INTO THE AREA WHICH WL CONTINUE THRU 12Z MON AND
CONDITIONS WL AGAIN BECOME MVFR OR IFR. KPUB SHOULD SEE VFR
CONDITIONS THRU THE EARLY EVENING AND THEN SNOW IS EXPECTED TO
REDUCE VSBYS AND CIGS INTO THE MVFR OR IFR CATEGORY THRU THE NIGHT.
KALS WL GENERALLY HAVE VFR CONDITIONS...HOWEVER SOME FOG IN THE AREA
THIS MORNING WL BRING IFR CONDITIONS THRU ABOUT 16Z AND THERE WL BE
THE POSSIBILITY OF SNOW SHOWERS IN THE VCNTY TODAY AND TONIGHT WHICH
COULD CAUSE PERIODS OF MVFR OR IFR CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061-
066-067-073-075.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065-
074.
BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
356 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 346 AM MST SUN MAR 1 2015
THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT
AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE
CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE
WY BORDER WHERE OROGRPAHIC SNOWS HAVE BEEN OCCURRING OVER THE HIGHER
TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS ACTIVITY HAS
SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY AND NWRN WELD
COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END AROUND 12Z EXCEPT IN
THE MTNS.
BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS
THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE
EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE
MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS
THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW
ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE
GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN
FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER
DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST
POPS OVE SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR
HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE
FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S.
OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE
MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER
SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID
LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER
NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH
STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE
PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY
BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC
OF LIGHT SNOW OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM MST SUN MAR 1 2015
VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE
CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO
160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES
MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO
COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON
WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL
VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY
AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES
ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY
TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH-
SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN
MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME
AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY
WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE
IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE
MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY
NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE
PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON
AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY
THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY
EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO
MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY
NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS
MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS
ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS
BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING
HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD
GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER
DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH
GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW
IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN
FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED
THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY
DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL
FOUR DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 346 AM MST SUN MAR 1 2015
SATELLITE SHOWS STRATUS AND SOME FOG DEVELOPING TO THE WEST AND
NORTH OF DIA EARLY THIS MORNING AS A WK DENVER CYCLONE HAS
DEVELOPED. IF SFC WINDS AT DIA BECOME LIGHT NNW THEN FOG AND
STRATUS COULD DVLP IN THE NEXT FEW HOURS AND LINGER THRU AT LEAST
16Z. BY LATE MORNING EXPECT IFR CONDITIONS WHICH MAY LINGER THRU
THE AFTN HOURS. AS FOR SNOW APPEARS BEST CHC LATE THIS AFTN AND
EVENING WILL STAY TO THE WEST AND SOUTH OF DIA WITH ONLY LIGHT
ACCUMULATIONS EXPECTED. WINDS WILL BE LIGHT AND VARIABLE THIS
MORNING AND THE MORE ELY BY MIDDAY. BY THIS EVENING WINDS WILL
BECOME MORE SELY AND THEN SLY AFTER MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1101 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE
SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY
ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH
POSITIONED NEAR THE MID-ATLANTIC COAST.
ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC
ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OR RAIN ACROSS MAINLY
CENTRAL AND NORTHERN PORTIONS OF THE FORECAST AREA LATE THIS
MORNING. THE HRRR AND OTHER HIGH RESOLUTION MESOSCALE MODELS
APPEAR TO BE HANDLING LOCATION/COVERAGE OF THE PRECIPITATION
FAIRLY WELL...AND GENERALLY SHOW THE RAIN SHIELD LIFTING NORTHWARD
THROUGH THE AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS
LOWERING RAIN CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE
DAY...BUT PROBABILITIES PEAKING AT 60-80 PERCENT IN SOUTHEAST
SOUTH CAROLINA EARLY THIS AFTERNOON BEFORE RAIN CHANCES LOWER AS
WELL LATE IN THE DAY.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL
TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE
SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR
IN THE BOUNDARY ADVECTING JUST INLAND ALONG THE COAST. WITH THE
MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ALONG THE COAST
JUST A BIT TO ACCOUNT FOR THE LATEST MODEL TRENDS...BUT TIGHTENED
THE GRADIENT FURTHER BY LOWERING TEMPERATURES WELL INLAND NEAR THE
CORE OF THE WEDGE. HIGH ARE NOW FORECAST TO RANGE FROM THE MID 40S
WELL INLAND TO THE MID 50S NEAR THE COAST.
TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING
INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A
CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING
ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW
CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY
FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY
DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES
AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT
READINGS MANY BE STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT
RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL
CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER
THROUGH 12Z MONDAY.
BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY
WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS.
DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS
NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER
TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE
IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION
THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A
CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD
LIFR THROUGH THE COASTAL CORRIDOR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH
LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO
TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE
CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER
TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER
GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS
UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO
1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA
INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL
BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
NEAR TERM...JAQ
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
709 AM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WHILE CLOUDY/COOL AND OCCASIONALLY DAMP WEATHER WILL BE THE MAIN
WEATHER FEATURES TO RING IN THE MONTH OF MARCH...THE MAIN FORECAST
QUEST TODAY WILL BE FORECASTING THE DIURNAL TEMP CURVE ALONG WITH
HIGH TEMPS IN A STUBBORN WEDGE PATTERN WITH THE COASTAL TROUGH
UNLIKELY TO PUNCTUATE THE VERY CHILLY NEAR SHORE SHELF WATERS.
EVEN THOUGH WE WILL KEEP THE WARM FRONT OFF THE COAST...QUITE A
FEW OF THE MODELS RESPECT THE 14C BOUNDARY LAYER TEMPS ADVECTING
OVER THE COASTAL EROSION OF THE SHALLOW COLDER AIR MASS AND
SUGGEST LATE AFTERNOON TEMPS ALONG AND EAST OF U.S. 17 WILL
EVENTUALLY REBOUND LATE AS SURFACE WINDS BECOME LIGHT AND PERHAPS
VARIABLE. THE 13 KM RAP AND ECMWF BOTH SHOW A VERY NARROW SLOT OF
NEAR 60 DEGREE SURFACE TEMPS JUST INLAND FROM THE BEACHES AROUND
NORTH CHARLESTON AND WHILE NOT FAR INLAND COULD BE LOCKED IN TO
LOWER TO MID 40 DEGREE AIR AT THE SURFACE. A THERMAL GRADIENT THAT
SIGNIFICANT IS NOT TOTALLY OUT OF THE QUESTION BUT WE OPTED JUST
TO TIGHTEN THE TEMP GRADIENT THIS AFTERNOON JUST A BIT WITH PLENTY
OF MESOSCALE UNCERTAINTIES INCLUDING RAINFALL COVERAGE. RAINFALL
AMOUNTS SHOULD GENERALLY BE LIGHT AND LESS THAN A QUARTER INCH FOR
THE MOST PART.
WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING INTO TONIGHT
WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A CONCERN FOR
DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING ADVECTS NE
INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW CONFIDENCE AT THIS
JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY FOG TO AREAS OF
FOG AS A TREND. THERE WILL PROBABLY BE PATCHY DRIZZLE AROUND THE
REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES AND THE SYNOPTIC
OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT READINGS MANY BE
STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AT KCHS...CIGS SHOULD BECOME IFR LATER THIS MORNING AS LIGHT
RAINS DEVELOP AND SPREAD BOTH INLAND AND NORTH ALONG THE COASTAL
CORRIDOR. AT SAV...CIGS LIKELY ALREADY LOCKED INTO IFR OR LOWER
THROUGH 12Z MONDAY.
BOTH SITES CAN EXPECT PERIODS OF LIGHT RAINS AND DRIZZLE TODAY
WITH PRECIP PROBABLY LASTING LONGER INTO THE AFTERNOON AT KCHS.
DESPITE THE HIGH CONFIDENCE IN CIGS BELOW 1 KFT...CONFIDENCE IS
NOT GOOD WITH HOW FAR DOWN CIGS WILL BUILD AND AT WHAT TIME LATER
TODAY AND TONIGHT. THE SYNOPTIC PATTERN FAVORS FOG AND DRIZZLE
IN THE WAKE OF LIGHT RAINS AND WE PLAYED CONTINUED DETERIORATION
THIS AFTERNOON AND TONIGHT WITH LOWER IFR CIGS/VSBYS. THERE IS A
CHANCE FOR BUILD DOWN FOG THIS EVENING OR OVERNIGHT AND WIDESPREAD
LIFR THROUGH THE COASTAL CORRIDOR.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY. A
BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT RESTRICTIONS
MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS AS AS WARM
FRONT. VFR CONDITIONS SHOULD RETURN ON WEDNESDAY...BEFORE ANOTHER
ROUND OF FLIGHT RESTRICTIONS OCCURS WEDNESDAY NIGHT INTO THURSDAY
AS A COLD FRONT SHIFTS THROUGH THE AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE THROUGH THE
MORNING WITH A MUCH LIGHTER GRADIENT BY LATER TODAY AND TONIGHT.
IT WILL DIFFICULT TO TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT
GIVEN THE STABLE CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW
TO N LATER TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT
OVER OUTER GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN
ADVISORY LEVELS UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS
COULD LOWER TO 1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE
LAND/SEA INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS
LIKELY WILL BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
644 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 637 AM CST SUN MAR 1 2015
OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR
RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH
TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE
BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME
PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE
LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF
THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK.
&&
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 535 AM CST SUN MAR 1 2015
TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID
MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO
CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED
ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW
MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG
WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST
MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS
AFTERNOON AND OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
542 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 535 AM CST SUN MAR 1 2015
TRICKY AVIATION FORECAST OVERNIGHT WILL PERSIST THRU AT LEAST MID
MORNING. FG HAS DEVELOPED ACROSS THE TAF SITES. THIS HAS LEAD TO
CIGS AND VSBY ISSUES ALONG WITH SOME FZFG. A CLOUD DECK HAS MOVED
ACROSS THE AREA TONIGHT...UNDER IT WARMER TEMPERATURES AND LOW
MVFR CIGS WERE OCCURRING. ONCE THIS DECK MOVES THROUGH THE FG
WANES. CID HAS BEEN REPORTING FLURRIES THIS AM AND SHOULD NOT LAST
MUCH AFTER SUNRISE. CLOUDS AND CIGS SHOULD GIVE WAY TO VFR THIS
AFTERNOON AND OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
539 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Monday Morning)
Issued at 527 AM CST SUN MAR 1 2015
VFR prevails at KTOP/KFOE/KMHK as scattered light snow bands
develop south of KTOP/KFOE. Will occasionally see MVFR conditions
within the snow bands before coming to an end by 16Z. Currently
not confident enough for IFR cigs to reach KTOP/KFOE as there is some
uncertainty in guidance on where heavier snow band develops. MVFR
stratus develops after 16Z before incoming dry air with the high
pressure scatters out lower stratus to VFR this evening.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ021>024-026-
034>040-054>056-058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
529 AM CST SUN MAR 1 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 528 AM CST SUN MAR 1 2015
A LOW STRATUS CLOUD DECK WILL BLANKET SOUTHWEST KANSAS THROUGH THE
DAY WITH SOME IMPROVEMENT. LIFR CIGS ALONG WITH IFR VSBYS AT
GARDEN CITY AND DODGE CITY SHOULD IMPROVE INTO THE IFR AND VFR
CATEGORIES, RESPECTIVELY, AFTER 15Z. BY THIS AFTERNOON MVFR CIGS
SHOULD PREVAIL AT GARDEN CITY AND DODGE CITY WITH VFR CIGS AT
HAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...GERARD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
423 AM CST SUN MAR 1 2015
...UPDATED LONG TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 109 AM CST SUN MAR 1 2015
IFR/LIFR STRATUS HAS DEVELOPED ACROSS FAR SOUTHWEST KANSAS,
AFFECTING MAINLY THE DDC AND GCK TAF SITES THIS MORNING. THE HI
RESOLUTIONS AND RAPID REFRESH MODELS INDICATE A NARROW BAND OF
WHAT WILL LIKELY BE EITHER SNOW OR SLEET, BETWEEN NOW AND MID
MORNING. BASED ON RECENT MODEL RUNS, THIS LOOKS LIKE IT MAY BE
MORE OF AN ISSUE FOR DDC THAN GCK, AND LITTLE IMPACT OTHER THAN
MVFR STRATUS AT HYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 20 20 10 10
LBL 34 23 43 37 / 20 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS JACKSON KY
648 AM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 647 AM EST SUN MAR 1 2015
CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME
SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL
JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS
MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME
SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE
RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN
FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST
WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE
BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE
SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT
DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS
MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD
ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY
AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW
HIGHLIGHTED.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 647 AM EST SUN MAR 1 2015
EXPECT FIELD MIN CIGS TO DEVELOP AT JUST ABOUT EVERY TAF SITE AS
A GOOD AREA OF RAIN ARRIVES INTO THE AREA THIS MORNING AND INTO
THE DAY TODAY. EXPECT SOME IFR VISIBILITY AS WELL. THESE
CONDITIONS WILL LAST THROUGH MUCH OF THE REST OF THE TAF PERIOD
AND PAST 00Z TONIGHT. AFTER 06Z TONIGHT...RAIN WILL CHANGE TO SNOW
WITH SOME LOCATIONS SEEING SIGNIFICANT REDUCTION IN VIS. WINDS
WILL GENERALLY BE LIGHT AND FROM THE SOUTHEAST THROUGH DAWN BEFORE
THEN SHIFTING TO THE SOUTHWEST AND INCREASING TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL 9 AM EST THIS MORNING FOR KYZ088-
106>115-117>120.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
933 AM EST SUN MAR 1 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 656 AM EST SUN MAR 1 2015
LATEST RUC/NAM GUIDANCE SHOWS LOW LEVEL MOISTURE BECOMING
WIDESPREAD BY NOON SO WILL FCST MVFR/FUEL ALTERNATE CIGS AROUND
1500 FT AT ALL THE TERMINALS FOR THIS AFTERNOON INTO THE EVENING.
SOME IFR CIGS BELOW 1000 FT CANNOT BE RULED OUT EITHER WITH THE
ARRIVAL OF A MILDER AIR MASS AND RISING SFC DEW POINTS OVER THE
SNOW PACK.
IMPROVEMENT IS EXPECTED LATE TONIGHT AS WINDS SHIFT TO THE
WEST/NORTHWEST BEHIND A WEAK SFC TROUGH. DRIER AIR BEHIND THIS
FEATURE SHOULD GRADUALLY LIFT CIGS TO VFR LEVELS ABOVE 3000 FT
FROM WEST TO EAST AFTER 06Z.
&&
.HYDROLOGY...
ISSUED AT 1132 AM EST SAT FEB 28 2015
CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS
EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT
COUPLE OF DAYS.
THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO
THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME
COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP
ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL
MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO
THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE
MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE
OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A
HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING
IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT
SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
907 AM EST SUN MAR 1 2015
.UPDATE...
THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW
EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE
LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND
REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS
SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP
THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE
EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF
ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS.
SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN
ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI
THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS
BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES
REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO
ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT
SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/.
THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL
MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL
MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE
ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY
TODAY.
&&
.AVIATION...ISSUED 554 AM EST SUN MAR 1 2015
THE WIDESPREAD SHIELD OF LIGHT SNOW HAS STRIPPED OUT OF SOUTHEASTERN
MICHIGAN THIS MORNING AS FAVORABLE UPPER LEVEL JET FORCING LIFTS OFF
TO THE NORTHEAST. BACKED OFF A FAIR AMOUNT ON THE MENTION FOR
ADDITIONAL SNOWFALL IN THE TAFS. THERE IS A HIGH AMOUNT OF
UNCERTAINTY AS WHETHER OR NOT PRECIPITATION THIS MORNING WILL BE
ABLE TO CLIP DTW. DID LEAVE A PERIOD OF IFR LIGHT SNOW THIS
AFTERNOON AS ANOTHER BOUT OF FORCING IS FORECASTED TO SLIDE OVER
SOUTHEASTERN MICHIGAN.
FOR DTW...LIGHT SNOW IS EXPECTED TO REFOCUS SOUTH OF THE DTW
TERMINAL THIS MORNING. IT IS TOUGH CALL ON WHETHER OR NOT A LONG
DURATION OF SNOW WILL IMPACT THE TERMINAL. EXPECTATIONS ARE THAT
LIGHT SNOW WILL FILL BACK IN FOR THE 19-23Z TIMEFRAME. SNOWFALL
ACCUMULATIONS WILL REMAIN RELATIVELY LIGHT...WITH PERHAPS AN INCH
FALLING DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THROUGH SUNDAY.
* HIGH IN PTYPE AS SNOW TONIGHT AND SUNDAY.
&&
.PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015
SHORT TERM...TODAY AND TONIGHT
SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A
POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT
ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW
ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO
LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING
WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS
THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD
AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON
AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL
STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL
SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE
HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS
SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE
DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A
STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW
ACCUMULATIONS THIS MORNING.
WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION
VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK
ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON
WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO
GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A
DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR
ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN
LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE
AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER
LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR
SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO
OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN
ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS
AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL
ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT
SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS.
THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP
TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z.
SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO
STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE
PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC
VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF
OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION
OF FLURRIES AT THIS TIME.
LONG TERM...
MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE
00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE
BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER
TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN
STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD
THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE
OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER
SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN
THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS
ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS
EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE
GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR
WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A
FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW.
EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR
NORTHERN CWA.
THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER
TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON
AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL
ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT
A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE
FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN
LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE
FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING
WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH
AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO
RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND
BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL
PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT
TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY
SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL
THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM.
AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE
PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH
AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA
WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR
WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART
OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST
THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN
THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS
INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES
EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS
EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK
INTO THE 30S.
MARINE...
A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS
BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE
NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST
BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY
UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY
NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN
ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....CB
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 644 AM EST SUN MAR 1 2015
A SW FLOW IN ADVANCE OF AN APRCHG LO PRES TROF THAT IS TAPPING A BIT
MORE LLVL MSTR WL BRING A PERIOD OF MVFR CIGS THIS MRNG INTO THE
AFTN BEFORE THE ARRIVAL OF DRIER AIR IN THE WAKE OF THE TROF PASSAGE
RETURNS CONDITIONS TO VFR IN THE AFTN. AS COLDER AIR RETURNS TNGT
BEHIND A REINFORCING COLD FROPA...MVFR CIGS AND PERHAPS SOME -SHSN
WL RETURN TO THE CMX AND IWD LOCATIONS THAT EXPERIENCE UPSLOPE
MOISTENING WITH THE EXPECTED GUSTY WNW FLOW. DOWNSLOPE NATURE OF
THIS FLOW INTO SAW SHOULD MAINTAIN VFR CONDITIONS THERE. ENUF DRY
AIR AHEAD OF A HI PRES RDG WL LIKELY BRING CLRG/VFR WX TO IWD LATE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
617 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 615 AM CST SUN MAR 1 2015
VFR CONDITIONS ARE FORECAST FOR THE KLBF AND KVTN TERMINALS TODAY
AND TONIGHT.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...ROBERG
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN
THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT.
VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE
WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT
STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH
THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN
925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH
OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE
NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS.
WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF
BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T
EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL
SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD
BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY
REGION...BUT VALUES WILL STILL RESIDE WELL WITHIN THE ADVISORY
CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW
MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY
REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF
AMOUNTS.
12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN
MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF.
06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE
LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH
FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME.
GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES
WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT
WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL
PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F
THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S
ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS
THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF
SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR
FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS
/BETWEEN 19Z-00Z/.
VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE
IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE
MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN
THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS
THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO
MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES.
THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE
WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY
AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST
WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT
PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING
THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER
CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA.
GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE
IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL
MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM
NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB
21ST.
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
STRONGEST RADAR RETURNS ASSOCIATED WITH 0.5-1.5SM SNOW BLANKET THE
REGION MAINLY TO THE SOUTH OF INTERSTATE 80 AT 1530Z. EXPECT THIS
AREAL DISTRIBUTION OF THE SNOWFALL INTENSITY TO CONTINUE THIS
AFTERNOON AS WEAK LOW PRESSURE FROM THE OHIO VALLEY TRACKS
EASTWARD INTO THE LAUREL HIGHLANDS AND SECONDARY WEAK LOW PRES
FORMS NEAR THE DELMARVA COAST. ACROSS THE NRN MTNS OF PA VSBYS
SHOULD AVERAGE NEARLY 1SM HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...LAMBERT/RXR
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
954 AM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
REGIONAL RADAR MOSAIC SHOWING VARIABLE RETURN INTENSITIES WITHIN
THE BROAD...MDTLY STG WEST-SWRLY WARM ADVECTION ALOFT.
VSBYS IN THE 1.5-3SM RANGE ACROSS THE SUSQ VALLEY AT 14Z...DECREASE
WWD TO BETWEEN 3/4-1SM ACROSS THE SWRN THIRD OF THE STATE. EXPECT
STEADY AND SLIGHTLY VARYING SNOWFALL INTENSITY TO CONTINUE THROUGH
THE REST OF THIS MORNING /AND MUCH OF THE AFTERNOON/ AS THE MEAN
925-850 MB ZERO DEG C WET BULB ISOTHERM IS STILL WELL TO THE SOUTH
OF THE MASON DIXON LINE AND WILL ONLY BE DRIFTING SLOWLY TO THE
NORTH DURING THE MIDDAY AND EARLY AFTERNOON HOURS.
WILL CONTINUE TO MODIFY SNOW ACCUM GRIDS WITH AN INJECTION OF
BLENDED NEW 09Z/12Z ENS AND HIGH RES MODEL GUIDANCE...BUT DON/T
EXPECT ANY EYE-OPENING CHANGES WITH OUR CURRENT FCST STORM TOTAL
SNOWFALL IN MOST LOCATIONS. TOTAL SNOWFALL MAY BE ADJUSTED UPWARD
BY AN INCH OR TWO ACROSS PORTIONS OF THE CENTRAL RIDGE AND VALLEY
REGION...BUT VALUES WILL STILL RESIDE WEEL WITHIN THE ADVISORY
CATEGORY. THE BIGGEST CONCERN STILL SURROUNDS THE TIMING OF SNOW
MIX/CHANGEOVER TO FZRA ACROSS THE SCENT AND LOWER SUSQ VALLEY
REGIONS LATE THIS AFTERNOON AND EVENING...AND ASSOCIATED QPF
AMOUNTS.
12Z RAP FOR KMDT SHOWS A BRIEF CHANGE TO SLEET AROUND 18-19Z THEN
MAINLY LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF.
06Z NAM IS VERY SIMILAR IN TIMING WITH THE CHANGEOVER ACROSS THE
LOWER SUSQ VALLEY AND CONTAINS AROUND OR JUST UNDER 0.25 INCH
FALLING AS FREEZING RAIN LATER TODAY AT KMDT AND KLNS. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME.
GOOD CONSISTENCY OF THE PAST SEVERAL MODEL RUNS AND ENSEMBLES
WITH RESPECT TO PTYPE INDICATES THAT THE BULK OF THIS WINTRY EVENT
WILL FALL AS SNOW TO THE NORTH OF THE RT22/322 CORRIDOR IN CENTRAL
PENN. TEMPS WILL BE NEARLY STEADY IN THE TEENS TO AROUND 20F
THROUGH 13Z...THEN SLOWLY RISE TO A LATE DAY HIGH IN THE UPPER 20S
ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID 30S ACROSS
THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH
TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE VERY WEAK LOW DEVELOPING ON THE DELMARVA AND RUSHING OFF
SHORE LATE TODAY INTO TONIGHT WILL ENHANCE THE MIXED PRECIP OR
FREEZING RAIN RATES OVER THE SERN COS FOR UP TO SEVERAL HOURS
/BETWEEN 19Z-00Z/.
VERY INTERESTING PART OF THE FORECAST WILL BE THE SNOW TYPE. THERE
IS A REALLY GOOD SIGNAL IN THE UPPER PART OF THE CLOUDS IN THE
MIDDLE OF THE DAY WHERE THE BEST VERTICAL MOTION IS SQUARELY IN
THE PREFERRED DENDRITIC GROWTH ZONE AROUND -15C. THEN...IT FALLS
THROUGH A HIGHLY MOIST/SATURATED COLUMN AND GETS ONLY CLOSE TO
MELTING INMOST PLACE. THIS COULD MAKE SOME GIANT BUT WET FLAKES.
THUS...A HIGH WATER CONTENT AND HEAVIER SNOW. THE SNOW PHYSICS...THE
WINDS ALOFT AND SFC TEMPS ALL WILL PULL THE SNOW ACCUMS ONE WAY
AND ANOTHER. HOWEVER...TEMP PROFILES LOOK PRETTY SIMILAR TO PAST
WEEKENDS VERY SIMILAR STORM. MANY SIMILARITIES EXIST WITH THAT
PREV STORM...BUT THE TEMPS APPEAR JUST SLIGHTLY COLDER. THINKING
THAT WE WILL GET BIGGER FLAKES BUT END UP WITH THE SAME WATER
CONTENT AND SLIGHTLY HIGHER SNOW ACCUMS OVER MOST OF THE AREA.
GREATEST FCST BUST POTENTIAL APPEARS TO EXIST IN THE SE...WHERE
IF THERE ENDS UP BEING NO TURNOVER TO MIXED PRECIP/ZR...IT WILL
MEAN THAT THE 0.6 INCHES OF WATER PROGGED THERE MAY NUDGE THEM
NEAR WARNING AMOUNTS. EVEN THIS SEEMS VERY SIMILAR TO THE FEB
21ST.
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THIS MID MORNING..THE LEADING EDGE OF THE LARGE SHIELD OF LIGHT
SNOW HAS OVERSPREAD CENTRAL PA...REDUCING VSBYS TO 2 MILES OR LESS
/IFR CONDITIONS/ ACROSS A WIDESPREAD AREA.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED ALL DAY AND INTO
THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 13Z...BUT WILL ALSO
DROP AS DAY WEARS ON. STILL THE THREAT OF SOME FZRA MIXING IN FOR
THE SOUTHERN TIER COUNTIES LATER THIS AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...RXR
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1026 AM EST SUN MAR 1 2015
.DISCUSSION...
MOISTURE ADVECTION AND DOWNSLOPE WINDS ARE DUELING FOR TERRITORY
ACROSS NE TN AND THE FOOTHILLS THIS MORNING. THE MOISTURE ADVECTION
APPEARS TO HAVE THE UPPER HAND AS CLOUDS ARE SLOWLY ADVANCING
EASTWARD...AND THE RAP SHOWS 925 MB WINDS THAT ARE ONLY 15 KTS.
HOWEVER...IT IS ENOUGH TO PROVIDE PLENTY OF SUNSHINE IN THE LEE OF
THE MOUNTAINS...ALLOW TEMPS TO REACH THE LOWER 50S ALREADY. WILL
UPDATE TO ADJUST TEMPERATUERS IN THIS AREA. UPSTREAM RADAR SHOWS
QUITE A BIT OF RAIN OVER MIDDLE TN...AND WHILE IT APPEARS THAT MUCH
OF IT IS NOT REACHING THE GROUND AT THE MOMENT...IT SHOULD MOVE
INTO OUR PLATEAU COUNTIES THIS AFTERNOON TO PRODUCE SOME LIGHT QPF.
WILL UPDATE POPS TO RAISE POPS IN THIS AREA FOR THE AFTERNOON...AND
LOWER POPS IN EASTERN SECTIONS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...AMENDED AVIATION SECTION.
NWS CHEYENNE WY
524 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 515 AM MST SUN MAR 1 2015
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY
VFR CONDITIONS PREVAILING. SPORADIC MVFR CIGS ARE POSSIBLE THROUGH
THE MORNING BENEATH A STRATUS DECK AROUND 5K FEET AGL. A COLD FRONT
WILL SWEEP ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW
TO AREAS ALONG AND SOUTH OF I80. MVFR TO IFR CIGS/VSBYS ARE LIKELY
AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
430 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 425 AM MST SUN MAR 1 2015
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH VFR
CONDITIONS PREVAILING. A COLD FRONT WILL SWEEP ACROSS THE AREA
THIS EVENING AND OVERNIGHT...BRINGING ANOTHER ROUND OF SNOW TO
AREAS ALONG AND SOUTH OF INTERSTATE 80. MVFR TO IFR CIGS/VSBYS
ARE LIKELY AFTER 06Z MON. WINDS WILL GENERALLY BE LIGHT THROUGH
THE TAF PERIOD.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...CLH
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
406 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 952 PM MST SAT FEB 28 2015
TOUGH FORECAST FOR OUR SOUTHEAST WYOMING AIRPORTS. RADAR SHOWING
AREA OF SNOW FILLING IN FROM KCYS TO KLAR...BUT IT IS NOT TOO HEAVY
AND BARELY RESTRICTING VISIBILITIES. GOING TO HOLD OFF LOWERING
CONDITIONS UNTIL AFTER 12Z AND CONFINE LOWER CONDITIONS TO KLAR.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
926 AM PST SUN MAR 1 2015
.SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS
OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK
WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED
SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND
ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE
NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY
THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO
MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH
SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND
SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY
THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS
IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE
ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN
ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF
THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER
THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST
HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND
LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE
GENERAL T-STORM OUTLOOK TODAY AS WELL.
SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A
FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY
AIRMASS OVER THE REGION.
NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS
ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING
OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD
AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE
SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS
ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS
OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT
MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER
TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW.
ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE
BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING
TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR
UNTIL MIDDLE OF THE MONTH.
&&
.AVIATION...AS OF 9:25 AM PST SUNDAY...VFR CONDITIONS AT ALL
TERMINALS THIS MORNING AND THIS WILL BE THE CASE FOR MUCH OF THE
DAY. SOME OF THE MODEL GUIDANCE SUGGESTS A LOW LEVEL CLOUD DECK
TONIGHT...BUT NOT TOTALLY BUYING THIS AS ANOTHER LOW APPROACHES
FROM THE NORTH.
VICINITY OF KSFO...FORECASTING VFR THROUGH THE PERIOD. HIGH CIGS
TOMORROW AS ANOTHER LOW SLIDES THROUGH. WILL NOT INTRODUCE ANY
PRECIP AS IT WILL BE SCT AND BEST CHC SOUTH OF SFO/OAK.
CONFIDENCE IS HIGH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR THROUGH THE PERIOD. SCT CU DECK
POSS THIS AFTERNOON.
CONFIDENCE IS HIGH.
&&
.MARINE...AS OF 09:22 AM PST SUNDAY...LIGHT TO MODERATE WINDS WILL
PREVAIL OVER THE BAY AREA WATERS TODAY AS A STORM SYSTEM EXITS TO
THE SOUTH. ANOTHER STORM SYSTEM WILL MOVER OVER THE REGION ON
MONDAY WITH ANOTHER CHANCE FOR SHOWERS...THUNDERSTORMS AND GUSTY
WINDS. WINDS WILL BE STRONGEST NORTH OF PIGEON POINT OVER THE
OUTER WATERS. LIGHT WINDS AND GENTLE SEAS DEVELOP ON TUESDAY.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: MM
VISIT US AT WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
845 AM PST SUN MAR 1 2015
.SYNOPSIS...MOSTLY SUNNY TODAY EXCEPT SOME SHOWERS OVER THE HILLS
OF MONTEREY AND SAN BENITO COUNTY THIS AFTERNOON. ANOTHER WEAK
WEATHER SYSTEM WILL DROP DOWN THE COAST BRINGING SOME SCATTERED
SHOWERS TO THE REGION MONDAY AFTERNOON...MAINLY OVER THE HILLS AND
ALONG THE COAST. HIGH PRESSURE BUILDS TUESDAY THROUGH NEXT WEEKEND
WITH A RETURN TO DRY CONDITIONS...MOSTLY CLEAR SKIES AND ABOVE
NORMAL DAYTIME TEMPERATURES.
&&
.DISCUSSION...AS OF 8:45 AM PST SUNDAY...SKIES ARE MOSTLY SUNNY
THIS MORNING ACROSS THE BAY AREA AS THE CALENDAR HAS TURNED TO
MARCH. YESTERDAYS UPPER LOW IS NOW WEST OF POINT CONCEPTION WITH
SOME COLD AIR ALOFT AND INSTABILITY OVER THE CENTRAL COAST AND
SOUTHERN CALIFORNIA. THE BAY AREA WILL SEE SKIES TURN PARTY CLOUDY
THIS AFTERNOON WITH SOME CLOUDS OVER THE HILLS AND AFTERNOON HIGHS
IN THE MID 60S. MONTEREY AND SAN BENITO COUNTY WILL STAY CLOSE
ENOUGH TO THE UPPER LOW TO KEEP AFTERNOON SHOWERS AND EVEN AN
ISOLATED T-STORM IN THE FORECAST. THE 12Z NAM AND LATEST RUNS OF
THE RAP AND HRRR MODELS ALL GENERATE SOME CONVECTIVE SHOWERS OVER
THE HILLS OF SAN BENITO AND MONTEREY COUNTY AND CURRENT FORECAST
HAS THAT COVERED. WILL HAVE TO MONITOR FOR SOME SMALL HAIL AND
LIGHTNING THREAT. SPC HAS THIS COVERED WITH THE REGION IN THE
GENERAL T-STORM OUTLOOK TODAY AS WELL.
SKIES WILL TURN MOSTLY CLEAR OVERNIGHT...SETTING THE STAGE FOR A
FAIRLY CHILLY NIGHT AS WINDS BECOME LIGHT WITH A COOL AND DRY
AIRMASS OVER THE REGION.
NEXT SYSTEM WILL QUICKLY DROP DOWN THE COAST ON MONDAY BUT MODELS
ARE IN SOLID AGREEMENT SHOWING THE MAIN RAIN SHIELD STAYING
OFFSHORE. THE SYSTEM IS DROPPING FROM THE NORTH WITH A FAIRLY COLD
AIRMASS ALOFT. THUS THERE WILL BE ENOUGH INSTABILITY TO PRODUCE
SOME SCATTERED SHOWERS MONDAY AFTERNOON...MAINLY OVER THE HILLS
ONCE AGAIN. ACTIVITY WILL BE LESS WIDESPREAD THAN WHAT WAS
OBSERVED SATURDAY AND EXPECT MOST AREAS TO STAY DRY. IN FACT
MODELS ARE SHOWING THE BEST CHANCES ONCE AGAIN OVER THE HIGHER
TERRAIN OF MONTEREY AND SAN BENITO WITH THE TRAJECTORY OF THE LOW.
ANY SHOWERS END AS THE SUN SETS MONDAY EVENING. THEN HIGH PRESSURE
BUILDS TUESDAY THROUGH NEXT WEEKEND WITH A WARMING AND DRYING
TREND. UNFORTUNATELY IT LOOKS LIKE ANY RAIN CHANCES DISAPPEAR
UNTIL MIDDLE OF THE MONTH.
&&
.AVIATION...AS OF 4:04 AM PST SUNDAY...THE CURRENT IR SATELLITE
IMAGE IS SHOWING YESTERDAYS STORM SYSTEM NOW CENTERED JUST OFF OF
POINT ARGUELLO. THIS IS PLACING THE SAN FRANCISCO AND MONTEREY BAY
AREA IN A ZONE OF OFFSHORE FLOW. THIS OFFSHORE FLOW WILL PREVENT
STRATUS FROM FORMING TODAY. HOWEVER...RESIDUAL MOISTURE FROM
YESTERDAYS STORM SYSTEM WILL PROMOTE THE FORMATION OF CUMULUS
CLOUDS THIS AFTERNOON.
VICINITY OF KSFO...VFR IS ANTICIPATED TO PREVAIL TODAY WITH MVFR
CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED TO
GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON.
CONFIDENCE IS HIGH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR IS ANTICIPATED TO PREVAIL TODAY WITH
MVFR CLOUD BASES THIS AFTERNOON. LIGHT OFFSHORE WINDS ARE EXPECTED
TO GIVE WAY TO A GENTLE SEA BREEZE THIS AFTERNOON.
CONFIDENCE IS HIGH.
&&
.MARINE...AS OF 2:42 AM PST SUNDAY...A WEAK SURFACE PRESSURE
GRADIENT WILL PROMOTE GENERALLY LIGHT WINDS ACROSS A MAJORITY OF
THE COASTAL WATERS TODAY. A STORM SYSTEM WILL SLIDE OVER THE
COASTAL WATERS ON MONDAY BRINGING ANOTHER ROUND OF SHOWERS AND
POTENTIAL THUNDERSTORMS TO THE AREA. THIS FAST MOVING SYSTEM WILL
BE OUT OF THE AREA TUESDAY LEAVING BEHIND LIGHT WINDS AND GENTLE
SEAS FOR THE REMAINDER OF THE WEEK.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: LARRY
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
1058 AM MST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM MST SUN MAR 1 2015
RADAR CONTINUES TO SHOW ECHOES OVR PORTIONS OF THE SANGRES THIS
MORNING...WITH WEB CAMS SHOWING SNOW IN THE CENTRAL AND SW MTNS.
THERE MAY BE OCNL SNOW SHOWERS IN SOME LOCATIONS OF THE SAN LUIS
VALLEY AS WELL. HYR CLOUDS HAVE DECREASED OVR THE SERN PLAINS...BUT
THERE ARE AREAS OF LOW CLOUDS AND FOG WITH THE POTENTIAL FOR SOME
FLURRIES.
AN UPR LOW WL REMAIN ALONG THE SRN CA COAST THRU THE DAY. THE UPR
LOW IS FORECAST TO WEAKEN TONIGHT...WITH THE UPR TROF BEGINNING TO
MOVE EASTWARD. W TO SW FLOW ALOFT WL CONTINUE ACRS CO TODAY AND
TONIGHT. THIS WL ALLOW THE CONTINUED STREAM OF MSTR INTO THE
CONTDVD. ALTHOUGH THE MTNS OF THE CONTDVD WL GET SEVERAL ADDITIONAL
INCHES OF ACCUMULATION TODAY AND TONIGHT...THE ERN SAN JUAN MTNS WL
STILL BE THE HARDEST HIT AREA. WINDS THIS MORNING ARE NOT REACHING
BLIZZARD CRITERIA OVER ZONE 68...BUT LATER TODAY THEY ARE EXPECTED
TO PICK UP AGAIN AND GUSTS OVERNIGHT SHOULD AGAIN BE QUITE
STRONG...AND WITH THE HEAVY SNOW CONTINUING THE BLSN AND NEAR ZERO
VSBYS WL BE QUITE DANGEROUS. WL LEAVE THE BLIZZARD WARNING AS IS.
THE NAM THE GFS AND HRRR ARE SHOWING DRY CONDITIONS OVR THE SERN
PLAINS AND I-25 CORRIDOR THRU EARLY AFTERNOON...SO WL REMOVE POPS IN
THESE AREAS. PROBABLY WL NOT SEE MUCH IN THE WAY OF PCPN OVR MOST
OF THE SAN LUIS VALLEY EITHER...BUT SOME ISOLD SHOWERS ARE STILL
POSSIBLE. MODELS CONTINUE TO SHOW PCPN RAMPING UP OVR THE ERN MTNS
AROUND MIDAFTERNOON AND SPILLING OUT OVR PORTIONS OF THE I-25
CORRIDOR THRU THE EVENING HOURS. THE LAST COUPLE DAYS...THE MODELS
HAVE KEPT THE FOCUS OF THE PCPN MAINLY FROM THE WET MTNS AND NRN
SANGRES AND LOCATIONS NORTH...NOT REALLY SHOWING ALL THAT MUCH FOR
THE SRN SANGRES...AND THE NAM AND HRRR STILL HAVE THAT TREND. THIS
MORNING THE GFS SHOWS MORE ACTIVITY OVR THE SRN SANGRES THIS
AFTERNOON THAN THE HRRR AND NAM. EAST TO SOUTHEASTERLY UPSLOPE OVR
EL PASO COUNTY THIS AFTERNOON AND EVENING HELP ENHANCE PCPN CHANCES
AND WL KEEP POPS HIGH IN THIS AREA. THE MODELS SHOW LITTLE CHANCE
FOR PCPN OVR MOST OF THE SERN PLAINS THIS AFTERNOON AND EVENING...
BUT WL PUT SOME ISOLD POPS IN THE FORECAST. BY LATE NIGHT...PCPN
OVR THE SERN PLAINS AND I-25 CORRIDOR SHOULD GENERALLY BE
LIGHT...HOWEVER THE SOUTHERLY FLOW OVR EL PASO COUNTY SHOULD KEEP
SNOW GOING ALTHOUGH IT SHOULD BE GENERALLY LIGHT BUT THERE SHOULD BE
A LITTLE ACCUMULATION WHICH COULD MAKE FOR A SLIPPERY MONDAY MORNING
COMMUTE. ALSO...THE NAM AND GFS CONTINUE TO SHOW THE POTENTIAL FOR
A FEW TO SEVERAL INCHES OF SNOW ACCUMULATIONS OR THE NRN SANGRES...
THE WET MTNS VALLEY AND FREMONT COUNTY THRU THE NIGHT. ONE CONCERN
IS THAT IF LIGHT PCPN DOES OCCUR OVR THE FAR SERN PLAINS...THE
SOUNDING PROFILE STILL DOES SHOW THE POTENTIAL FOR SOME LIGHT
FREEZING DRIZZLE...BUT WL NOT MENTION IN THE FORECAST AT THIS TIME.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 414 AM MST SUN MAR 1 2015
...UNSETTLED WEATHER CONTINUES THROUGH WEDNESDAY WITH DRIER AND
WARMER WEATHER THEREAFTER...
MONDAY-MONDAY NIGHT...SOUTHWEST FLOW ALOFT INCREASES AGAIN ACROSS
THE REGION ON MONDAY AND BECOMES MORE WESTERLY MONDAY NIGHT WITH A
STRONG SUBTROPICAL JET STREAM TRANSLATING ACROSS THE STATE AS
SOUTHERN STREAM ENERGY ACROSS THE DESERT SW MERGES WITH ANOTHER
PIECE OF ARCTIC AIR WITHIN A STRONG NORTHERN STREAM TROUGH DIGS
ACROSS THE INTERMOUNTAIN WEST AND NORTHERN GREAT BASIN. SNOWFALL
OVER AND NEAR THE MOUNTAINS LOOKS TO BE ON THE WANE EARLY MONDAY
MONDAY MORNING BUT IS EXPECTED TO INCREASE AGAIN MONDAY AFTERNOON
AND EVENING...ESPECIALLY OVER AND NEAR THE CONTDVD...WITH INCREASING
MOISTURE...UVV AND OROGRAPHICS AHEAD OF THE COMBINING SYSTEMS.
CURRENT WINTER WEATHER HIGHLIGHTS ACROSS THE HIGHER TERRAIN THROUGH
THE DAY MONDAY MAY NEED TO BE EXTENDED INTO EARLY TUESDAY
MORNING...WITH ANOTHER ROUND OF MODERATE TO HEAVY SNOWFALL
EXPECTED...ESPECIALLY ALONG AND WEST OF THE DVD. IN ADDITION TO THE
SNOW...INCREASING FLOW ALOFT WILL LEAD TO STRONG AND GUSTY SOUTHWEST
TO WEST WINDS OF 25 TO 45 MPH AND AREAS OF BLOWING AND DRIFTING SNOW
ACROSS THE HIGHER TERRAIN. FURTHER EAST...A FEW MORNING SHOWERS WILL
BE POSSIBLE ACROSS THE EASTERN PLAINS WITH BREEZY TO WINDY
CONDITIONS HELPING TO BOOST HIGHS MONDAY INTO THE 30S AND 40S AND
KEEP OVERNIGHT LOWS FAIRLY MILD MAINLY IN THE 20S AND 30S.
TUESDAY-WEDNESDAY NIGHT...STRONG WEST TO NORTHWEST FLOW ALOFT ACROSS
THE AREA TUESDAY MODERATES THROUGH THE DAY WEDNESDAY AND WEDNESDAY
AS NORTHERN STREAM TROUGH AND ARCTIC AIRMASS DIGS ACROSS THE ROCKIES
AND INTO THE HIGH PLAINS. SOME DIFFERENCES IN TIMING OF ARCTIC FRONT
ACROSS THE AREA WITH LEADING EDGE OF COLD AIR MOVING ACROSS EASTERN
COLORADO EARLY TUESDAY MORNING AND HIGHS MOST LIKELY BEING REACHED
BY MID MORNING WITH TEMPERATURES COOLING THEREAFTER. COULD SEE SOME
SHOWERS ACROSS THE AREA WITH THE FRONT THOUGH BEST CHANCES OF LIGHT
TO MODERATE SNOWFALL LOOKS TO BE LATER TUESDAY AFTERNOON AND NIGHT
AS ANOTHER LOBE OF ENERGY AND SECONDARY SURGE OF COLD AIR DROPS
ACROSS THE ROCKIES KEEPING TEMPERATURES WELL BELOW SEASONAL AVERAGES
WITH LOWS MAINLY IN THE SINGLE DIGITS AND HIGHS MAINLY IN THE TEENS
AND 20S. DRIER AIR AND SUBSIDENCE WITHIN THE MODERATING NORTHWEST
FLOW ALOFT WILL ALLOW FOR SNOW TO GRADUALLY END WEDNESDAY AFTERNOON
AND EVENING.
THURSDAY-SATURDAY...A WARMING AND DRYING TREND REMAINS IN THE OFFING
FOR THE END OF THE WORK WEEK AND INTO THE WEEKEND AS UPPER LEVEL
RIDGING BUILDS ACROSS THE WEST COAST AND INTO THE GREAT BASIN.
LATEST MODELS...HOWEVER...ARE INDICATING ANOTHER WEAK WAVE WITHIN
THE STRONGER NORTHWEST FLOW ALOFT ACROSS THE NORTH TIER OF
STATES...DROPPING ACROSS THE ROCKIES ON SATURDAY. WITH THAT
SAID...HAVE STAYED WITH MODEL CONSENSUS POPS WHICH BRINGS SLIGHT
CHANCES FOR LIGHT SNOW ACROSS THE HIGHER TERRAIN ON SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1048 AM MST SUN MAR 1 2015
KCOS...VFR TO INTERMITTENT MVFR DUE TO PATCHY LIGHT GROUND FOG
THROUGH 20-21Z...THEN TRENDING TOWARDS IFR AS SNOW MOVES BACK INTO
THE AREA. SHOULD REMAIN IFR THROUGH 12-14Z DUE TO SNOW...FOG AND
LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A FEW
MORE HOURS MONDAY MORNING.
KPUB...VFR UNTIL 21-23Z THEN IFR-MVFR CONDITIONS EXPECTED AS SNOW
MOVES IN. SHOULD REMAIN MVFR-IFR THROUGH 12-14Z DUE TO SNOW...FOG
AND LOW CLOUD DECK THOUGH GROUND FOG MAY LINGER BEYOND SNOW FOR A
FEW MORE HOURS MONDAY MORNING.
KALS...INTERMITTENT SNOW HAS MOVED BACK INTO THE AREA THIS
AFTN...AND WITH PATCHY FOG AND LOW CLOUDS WILL CONTINUE MVFR TO
IFR CONDITIONS OVER THE NEXT 24 HRS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 5 PM MST MONDAY FOR COZ058-060-061-
066-067-073-075.
WINTER WEATHER ADVISORY UNTIL 5 PM MST MONDAY FOR COZ059-064-065-
074.
BLIZZARD WARNING UNTIL 11 PM MST MONDAY FOR COZ068.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1010 AM MST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1003 AM MST SUN MAR 1 2015
MINOR ADJUSTMENTS TO THE GRIDS THIS MORNING..I SLOWED THE TIMING
OF THE HIGHER POPS A BIT THIS AFTERNOON. OVERRUNNING MOISTURE WILL
PRODUCE JUST SOME LIGHT SNOW TODAY...OVERALL SLGT CHC IN THE URBAN
CORRIDOR...WITH CHC POPS NEAR THE FOOTHILLS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 346 AM MST SUN MAR 1 2015
THE FLOW ALOFT WILL BECOME MORE SWLY TODAY AND THEN INCREASE TONIGHT
AS AN UPPER LEVEL LOW REMAINS OVER CALIFORNIA. SO FAR MOST OF THE
CWA IS ON THE SUBSIDENT SIDE OF THE UPPER LEVEL EXCEPT CLOSER TO THE
WY BORDER WHERE OROGRAPHIC SNOWS HAVE BEEN OCCURRING OVER THE
HIGHER TERRAIN OF BOULDER AND LARIMER COUNTIES. SOME OF THIS
ACTIVITY HAS SPREAD ACROSS THE LOWER ELEVATIONS OF LARIMER COUNTY
AND NWRN WELD COUNTY. APPEARS MOST OF THIS ACTIVITY WILL END
AROUND 12Z EXCEPT IN THE MTNS.
BY LATER THIS MORNING THRU EARLY AFTN DRIER AIR WILL SPREAD ACROSS
THE MTNS WHICH WILL REDUCE SNOW CHANCES. BY LATE AFTN INTO THE
EVENING HOURS ANOTHER SURGE OF MOISTURE IS SUPPOSED TO MOVE INTO THE
MTNS. SATELLITE DOES SHOW ENHANCEMENT OVER ARIZONA SO IT APPEARS
THAT THIS MOISTURE IS REAL. THUS SHOULD SEE AN INCREASE IN SNOW
ACTIVITY IN THE MTNS. AT LOWER ELEVATIONS NOT SURE HOW THINGS ARE
GOING TO EVOLVE. THE HRRR AND RAP SHOW SNOW DEVELOPING IN THE SRN
FOOTHILLS AND AFFECTING SRN AREAS OF THE URBAN CORRIDOR AND PALMER
DIVIDE BY LATE AFTN INTO THE EARLY HOURS. THUS WILL KEEP HIGHEST
POPS OVER SRN AREAS OF CWA WITH LOWER POPS FURTHER NORTH. AS FOR
HIGHS WILL KEEP READINGS N THE 20S OVER NERN CO EXCEPT OVER THE
FAR NERN CORNER WHERE READINGS MAY RISE INTO THE LOWER 30S.
OVERNIGHT SWLY FLOW WILL INTENSIFY WITH ABUNDANT MOISTURE IN THE
MTNS. PLACEMENT OF UPPER LEVEL JET COULD ALLOW FOR SOME HEAVIER
SNOWFALL LATE TONIGHT IN ZN 31 AND PORTIONS OF ZN 33 ALTHOUGH MID
LVL TEMPS ARE WARMING QUITE A BIT WHICH COULD LIMIT AMOUNTS. OVER
NERN CO THE LOW LVL FLOW WILL BECOME MORE SSE AFTER MIDNIGHT WITH
STG DOWNSLOPING COMING OFF THE PALMER DIVIDE WHICH SHOULD DECREASE
PCPN CHANCES FM DENVER SOUTH TO THE PALMER DIVIDE. CLOSER TO THE WY
BORDER THE LOW LVL FLOW WILL BE MORE SELY SO COULD STILL SEE A CHC
OF LIGHT SNOW OVERNIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM MST SUN MAR 1 2015
VERY STRONG SOUTHWESTERLY JET LEVEL FLOW IS PROGGED OVER THE
CWA MONDAY AND MONDAY NIGHT. THE PROGGED SPEEDS ARE IN THE 130 TO
160 KNOT RANGE AT JET LEVEL. BY TUESDAY...THE FLOW ALOFT BECOMES
MORE WESTERLY THROUGH THE DAY AS AN UPPER TROUGH MOVES INTO
COLORADO. THE UPPER TROUGH IS OVER THE STATE TUESDAY AFTERNOON
WELL INTO THE EXTENDED PERIOD. THERE IS WEAK UPWARD QG VERTICAL
VELOCITY PROGGED FOR THE CWA MONDAY...BUT IT BECOMES STRONGER BY
AFTERNOON AND OVERNIGHT. ANOTHER BATCH OF UPWARD ENERGY MOVES
ACROSS THE FORECAST AREA TUESDAY AFTERNOON WITH SUBSIDENCE BY
TUESDAY NIGHT. THE BOUNDARY LAYER FLOW LOOKS TO BE SOUTH-
SOUTHWESTERLY ON MONDAY. NORMAL DIURNAL PATTERNS SHOULD KICK IN
MONDAY EVENING...THEN A COLD FRONT WITH UPSLOPE MOVES IN SOMETIME
AFTER MIDNIGHT AND TUESDAY MORNING AT DAWN. NORTH-NORTHEASTERLY
WINDS ARE PROGGED TUESDAY AND TUESDAY NIGHT. FOR MOISTURE...THERE
IS BIT OVER THE PLAINS MONDAY...BUT DEEPER MOISTURE FOR THE
MOUNTAINS. MOISTURE REMAINS PRETTY DEEP OVER THE MOUNTAINS MONDAY
NIGHT...WITH AN INCREASE AFTER THE FRONT MOVES ACROSS FOR THE
PLAINS. MOISTURE IS PRETTY DEEP IN ALL AREAS BY TUESDAY AFTERNOON
AND NIGHT. THERE IS SOME QPF PROGGED OVER THE MOUNTAINS MONDAY
THROUGH TUESDAY EVENING. FOR THE PLAINS THERE IS SOME MONDAY
EVENING THROUGH TUESDAY NIGHT. FOR POPS...WILL NOT ALTER THINGS TO
MUCH...MAY START THEM OVER THE PLAINS A BIT LATER ON MONDAY
NIGHT/TUESDAY MORNING. NO HIGHLIGHTS RIGHT NOW...BUT MOUNTAINS
MIGHT NEED SOMETHING. WE`LL SEE. FOR TEMPERATURES...MONDAY`S HIGHS
ARE 4-11 C WARMER THAN TODAY`S EXPECTED HIGHS. TUESDAY`S HIGHS
BEHIND THE FRONT COOL BACK OFF 11-18 C FROM MONDAY`S. DEPENDING
HOW MUCH IT CLEARS OUT TUESDAY NIGHT/WEDNESDAY MORNING...WE COULD
GET BELOW ZERO FOR LOWS OUT ON THE FOR THAT PERIOD. FOR THE LATER
DAYS...WEDNESDAY THROUGH SATURDAY...MODELS HAVE THE UPPER TROUGH
GET THROUGH THE CWA ON WEDNESDAY...THEN WEAK NORTHWESTERLY FLOW
IS PROGGED FOR THE CWA WEDNESDAY NIGHT INTO FRIDAY MORNING. THEN
FAIRLY WEAK WEST OR WEST-NORTHWESTERLY FLOW ALOFT IS PROGGED
THROUGH SATURDAY. MOISTURE IS LACKING...IT ACTUALLY LOOKS PRETTY
DRY ALL FOUR DAYS. TEMPERATURES STAY BELOW SEASONAL NORMALS ALL
FOUR DAYS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1003 AM MST SUN MAR 1 2015
TREND OF IMPROVING CONDITIONS AT KDEN THE REMAINDER OF THE
MORNING...IFR NO LONGER EXPECTED BUT MAINLY MVFR CIG/VSBY
RESTRICTIONS AT TIMES THROUGH THE AFTN. BEST CHC OF SNOW LATE
THIS AFTN AND EVENING WILL STAY TO THE WEST AND SOUTH OF DIA NEAR
KAPA AND KBJC WITH ONLY LIGHT ACCUMULATIONS EXPECTED. WINDS WILL
BE LIGHT AND VARIABLE THIS MORNING AND THE MORE ELY BY THIS AFTN.
BY THIS EVENING WINDS WILL BECOME MORE SELY AND THEN SLY AFTER
MIDNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...COOPER
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS NEW YORK NY
426 PM EST SUN MAR 1 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL APPROACH FROM THE WEST...THEN PASS THROUGH
TONIGHT AS WEAK LOW PRESSURE DEVELOPS SOUTH OF LONG ISLAND.
HIGH PRESSURE WILL BRIEFLY BUILD IN MONDAY INTO MONDAY NIGHT...
THEN PASS TO THE EAST ON TUESDAY. LOW PRESSURE WILL TRACK WELL
NORTH OF THE AREA TUESDAY NIGHT AND WEDNESDAY...WITH A WARM FRONT
LIFTING INTO THE AREA TUESDAY NIGHT...FOLLOWED BY A COLD FRONT
WEDNESDAY AND A REINFORCING COLD FRONT WEDNESDAY NIGHT.
HIGH PRESSURE WILL THEN BUILD IN FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
BAND OF FRONTOGENETICALLY FORCED MODERATE TO HEAVY SNOW ACROSS
LONG ISLAND AND NYC METRO ATTM...WITH SNOWFALL RATES UP TO AN
INCH PER HOUR. PER HRRR THIS BAND SHOULD SHIFT MORE INTO LONG
ISLAND AND COASTAL CT OVER THE NEXT COUPLE OF HOURS...AND PERSIST
THERE INTO AT LEAST THE FIRST PART OF THIS EVENING. HAVE BUMPED UP
SNOWFALL TOTALS ESPECIALLY ACROSS SUFFOLK COUNTY AND AND COASTAL
SE CT. GIVEN THIS PLUS A SPOTTER REPORT OF 2 INCHES ON THE GROUND
IN WEST ISLIP...WILL ISSUE WINTER STORM WARNINGS FOR THOSE
AREAS...WHERE 5-7 INCHES OF ACCUMULATION IS EXPECTED.
ELSEWHERE EXPECT A SOLID ADVY EVENT...WITH 4-6 INCHES OF SNOW.
A SPOTTER FROM BROOKLYN REPORTED SLEET MIXING IN WITH THE
SNOW...WHICH CORRELATES WELL WITH RADAR DUAL-POL CC.
THIS TRANSITION SHOULD BE BRIEF...AND EXPECT PRECIP TO TRANSITION
BACK MORE TOWARD SNOW BEFORE A MORE DEFINITE TRANSITION LINE NOW
EXTENDING FROM TTN-WRI-ACY MOVES IN. THIS SHOULD MAKE IT TO NYC
METRO BY 00Z...THEN TO NEAR TEB-ISP BY LATE EVENING. AREAS SOUTH
OF THAT LINE SHOULD SEE A GLAZE TO A TENTH OF AN INCH OF ICE THIS
EVENING BEFORE PRECIP WINDS DOWN AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE APPROACHES FROM THE WEST ON MONDAY...THEN BUILDS
OVERHEAD ON TUESDAY. HIGHS ON MON WILL BE IN THE MID AND UPPER
30S...WITH A BRISK NW WINDS GUSTING TO 25-35 MPH. MUCH COLDER AIR
WILL FOLLOW FOR MON NIGHT...AND UNDERCUT MOS GUIDANCE BY 2-3 DEG
GIVEN DIMINISHING WINDS LATE AT NIGHT AND FRESH SNOW COVER...WITH
LOWS IN THE TEENS FOR NYC METRO AND LONG ISLAND...AND SINGLE
DIGITS FARTHER NORTH/WEST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS ARE IN DECENT AGREEMENT AT H5 THROUGH THE WEEK...ALTHOUGH
SLIGHT DIFFERENCES IN HEIGHTS BEGIN TO TAKE SHAPE DURING THE LATTER
HALF FROM A DIGGING TROF IN THE MIDDLE OF THE COUNTRY.
RIDGING AT THE SFC AND ALOFT TRACKS MOVES OFFSHORE ON TUE. PCPN WILL
OVERSPREAD THE AREA LATE TUE AFTN AS SNOW...BUT WITH INCREASING S-SW
WINDS AND STRONG WAA TEMPS WILL WARM TUE EVE/NIGHT WITH SNOW
CHANGING TO MIXED PCPN THEN RAIN FROM S TO N. WARM FRONT LIFTS
TOWARDS THE AREA TUE NIGHT...BUT THERE IS SOME UNCERTAINTY IF THE
LLJ WILL BE STRONG ENOUGH TO PUSH IT THROUGH AT THE SFC. CLIMATOLOGY
SAYS NO WITH THE LOW SO FAR TO THE NW AND VERY COLD WATERS/ICE...SO
HAVE GONE BELOW GUIDANCE WITH HIGHS WED...GENERALLY LOWER 40S WITH
MID 40S POSSIBLE IN NYC METRO.
THE COMBINATION OF THESE TEMPS AND RAINFALL WILL RESULT IN MELTING
SNOWPACK WHICH COULD LEAD TO MINOR FLOODING ACROSS THE AREA ON WED.
COLD FRONT MOVES ACROSS WED FOLLOWED BY A REINFORCING COLD FRONT WED
NIGHT. THE NORTHERN EDGE OF THE PCPN SHIELD OF A SOUTHERN STREAM
SYSTEM RIDING ALONG THIS SECONDARY BOUNDARY COULD KEEP PCPN
LINGERING WED NIGHT INTO THU. MODELS REMAIN SPLIT ON THIS...GFS IS
FURTHER SUPPRESSED THAN EC SO HAVE KEPT CHC POPS.
COLD AIR FILTERS IN BEHIND THE INITIAL COLD FRONT ON WED. THERMAL
PROFILES SUPPORT A CHANGE BACK OVER TO SNOW WED NIGHT AND THU WITH
ANY PCPN ASSOCIATED WITH THE SOUTHERN STREAM SYSTEM. ANOTHER SHOT OF
ARCTIC AIR INFILTRATES THE AREA THU INTO FRI.
STRONG CANADIAN HIGH PRES THEN BUILDS TOWARDS THE AREA INTO THE
WEEKEND WITH DRY WEATHER. TEMPS WILL REBOUND AROUND 5 DEGREES BELOW
NORMAL NEXT WEEKEND WITH WAA DEVELOPING.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
WEAK LOW PRESSURE WILL TRACK TO THE SOUTH THEN EAST OF LONG ISLAND
TONIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST ON MONDAY.
MAINLY LIFR TO VLIFR ACROSS THE AREA...WITH POCKETS OF IFR IN MAINLY
MODERATE TO OCCASIONALLY HEAVY SNOW. SHOULD REMAIN ALL SNOW
KSWF/KHPN/KBDR/KGON/KTEB.
SNOW WILL CHANGE TO ZR AT KJFK AROUND 1Z AND CHANGE TO ZR AT KISP
AROUND 2Z. FOR NOW HAVE KEPT CHANGE OVER AT KEWR AND KLGA TO ZR AT
3Z...BUT BEGINNING TO HAVE SOME DOUBTS THIS WILL OCCUR.
PRECIPITATION WILL COME TO AN END A COUPLE OF HOURS ON EITHER SIDE
OF MIDNIGHT FROM W TO E.
MOST LIKELY TOTAL RUNWAY ACCUMULATIONS BY 06Z MON: KGON/KISP...4-7
INCHES. KSWF/KHPN/KBDR/KTEB/KLGA/KJFK/KEWR...4-6 INCHES.
AFTER THE PRECIPITATION ENDS...CONDITIONS TRANSITION TO VFR BY
AROUND 12Z.
WINDS IN THE PROCESS OF BECOMING LIGHT AND VARIABLE THROUGHOUT. AS
THE PRECIPITATION ENDS WINDS GO SW THEN W AT UNDER 10 KT EARLY
MONDAY MORNING. WINDS THEN BECOME NW AND INCREASE TO 13-18G22-27KT
BY AROUND MID MONDAY MORNING.
.OUTLOOK FOR 18Z MONDAY THROUGH WEDNESDAY...
.MONDAY AFTERNOON-TUESDAY MORNING...VFR. NW WINDS G25-30 KT
LIKELY INTO EARLY MONDAY EVENING.
.TUESDAY AFTERNOON...CHANCE MVFR OR LOWER IN SNOW.
.TUESDAY NIGHT...IFR OR LOWER LIKELY. SNOW...CHANGING TO A WINTRY
MIX AFTER MIDNIGHT...AND THEN RAIN LATE AT ALL TERMINALS EXCEPT KSWF
AND POSSIBLY CT TERMINALS. LLWS LIKELY.
.WEDNESDAY...IFR OR LOWER POSSIBLE IN ANY RAIN - WITH A BRIEF PERIOD
OF ZR POSSIBLE IN THE MORNING AT KSWF. LLWS POSSIBLE IN THE MORNING.
.WEDNESDAY NIGHT-THURSDAY...MVFR OR LOWER POSSIBLE IN ANY
PRECIPITATION...OTHERWISE VFR. IF THERE IS PRECIPITATION...SHOULD
CHANGE TO ALL SNOW WEDNESDAY NIGHT AND POSSIBLY CONTINUE INTO
THURSDAY. NW WINDS G15-20KT POSSIBLE.
.THURSDAY NIGHT-FRIDAY...VFR. NW WINDS G15-20KT POSSIBLE THURSDAY
NIGHT.
&&
.MARINE...
TRANQUIL TODAY WITH DEPARTING HI PRES...THEN WINDS INCREASE TO SCA
LEVELS MON AND GRADUALLY DIMINISH MON NIGHT. EXPECT SUB-ADVY CONDS
ON TUE AS HIGH PRES BUILDS ACROSS. SCA CONDS POSSIBLE ON THE OCEAN
TUE NIGHT INTO THU BEHIND THE PASSAGE OF TWO COLD FRONTS...WITH A
TIGHT PRES GRADIENT. SUB-ADVY CONDS THEN EXPECTED THEREAFTER AS
THE PRES GRADIENT WEAKENS WITH ANOTHER BUILDING HIGH.
&&
.HYDROLOGY...
LIQUID EQUIVALENT QPF OF 4-6 TENTHS OF AN INCH EXPECTED TONIGHT.
WITH ALL OF THIS EXPECTED TO BE EITHER FROZEN OR FREEZING
PRECIPITATION...NO IMMEDIATE HYDROLOGIC IMPACT EXPECTED.
BETWEEN 1/2 TO 1 INCH OF LIQUID EQUIVALENT PCPN IS POSSIBLE LATE
TUE THROUGH WED. SOME OF THIS WILL FALL AS RAIN...THEREFORE THE
COMBINATION OF THIS AND MELTING SNOW PACK COULD CAUSE MINOR
FLOODING ISSUES.
ICE WILL CONTINUE TO DEVELOP ON LOCAL AREA RIVERS AND STREAMS AS
TEMPERATURES REMAIN WELL BELOW AVERAGE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR CTZ005>012.
NY...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NYZ067>075-
078>081-176>179.
NJ...WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR NJZ002-004-
006-103>108.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO MIDNIGHT EST MONDAY
NIGHT FOR ANZ330-335-338-340-345.
SMALL CRAFT ADVISORY FROM 6 AM MONDAY TO 6 AM EST TUESDAY FOR
ANZ350-353-355.
&&
$$
SYNOPSIS...GOODMAN/24
NEAR TERM...GOODMAN
SHORT TERM...GOODMAN
LONG TERM...24
AVIATION...MALOIT
MARINE...GOODMAN/24
HYDROLOGY...GOODMAN/24
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
116 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO WEDGE SOUTHWARD OVER THE REGION TODAY
WHILE A COASTAL TROUGH LINGERS OFF THE SOUTHEAST COAST. A COLD FRONT
WILL SHIFT OVER THE AREA LATE MONDAY THEN STALL JUST SOUTH OF THE
AREA MONDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTH. THE FRONT
WILL LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON AHEAD OF A
COLD FRONT THAT SHIFTS THROUGH THE AREA LATE WEDNESDAY INTO THURSDAY.
HIGH PRESSURE WILL THEN BUILD OVER THE AREA THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
TODAY...A WELL PRONOUNCED COASTAL TROUGH LINGERS JUST OFF THE
SOUTHEAST U.S. COAST...WHILE A SURFACE WEDGE REMAINS FIRMLY
ENTRENCHED ACROSS INLAND AREAS WITH THE WEAKENING PARENT HIGH
POSITIONED NEAR THE MID-ATLANTIC COAST.
ABUNDANT LOW AND MID LEVEL MOISTURE COMBINED WITH ISENTROPIC
ASCENT CONTINUES TO SUPPORT GOOD COVERAGE OF RAIN ACROSS
SOUTHEAST SOUTH CAROLINA EARLY THIS AFTERNOON. THE HRRR AND OTHER
HIGH RESOLUTION MESOSCALE MODELS APPEAR TO BE HANDLING
LOCATION/COVERAGE OF THE PRECIPITATION FAIRLY WELL...AND GENERALLY
SHOW THE RAIN SHIELD CONTINUING TO LIFT NORTHWARD THROUGH THE
AFTERNOON. AS A RESULT...THE POP FORECAST SHOWS LOWERING RAIN
CHANCES ACROSS SOUTHEAST GEORGIA THROUGH THE DAY...BUT
PROBABILITIES PEAKING AT 70-90 PERCENT IN SOUTHEAST SOUTH
CAROLINA THROUGH MID-AFTERNOON BEFORE RAIN CHANCES LOWER AS WELL
LATE IN THE DAY.
THE TEMPERATURE FORECAST REMAINS VERY TRICKY. WHILE THE COASTAL
TROUGH IS NOT EXPECTED TO SHIFT INLAND DUE TO THE COOL/STABLE
SHELF WATERS...MOST OF THE MODELS CONTINUE TO SHOW SOME WARMER AIR
IN THE BOUNDARY LAYER ADVECTING JUST INLAND ALONG THE COAST. WITH
THE MOST RECENT UPDATE...HAVE LOWERED TEMPERATURES ACROSS THE
BOARD 1-3 DEGREES TO ACCOUNT FOR THE LATEST TRENDS. HIGHS ARE NOW
FORECAST TO RANGE FROM THE LOWER/MID 40S INLAND TO THE MID 50S
NEAR THE COAST.
TONIGHT...WIDESPREAD LOW CLOUDS WILL BLANKET THE REGION GOING
INTO TONIGHT WITH STRATUS POTENTIALLY BUILDING DOWN ENOUGH TO BE A
CONCERN FOR DENSE FOG IN SOME AREAS TONIGHT AS SIGNIFICANT DRYING
ADVECTS NE INTO THE 925-850 MB LAYER. WE HAVE FAIRLY LOW
CONFIDENCE AT THIS JUNCTURE BUT ENOUGH TO JUSTIFY UPGRADING PATCHY
FOG TO AREAS OF FOG AS A TREND. THERE WILL PROBABLY BE PATCHY
DRIZZLE AROUND THE REGION TONIGHT GIVEN FORECAST SOUNDING PROFILES
AND THE SYNOPTIC OVERVIEW. LOW TEMPS MAINLY 40 TO 45 DEGREES BUT
READINGS MANY BE STEADY OR RISING LATE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
MONDAY...A BRIEF WARMUP WILL OCCUR IN ADVANCE OF A COLD FRONT THAT
APPROACHES FROM THE NORTH LATE IN THE DAY. TEMPS SHOULD PEAK IN THE
MID 60S NORTH TO AROUND 70 SOUTH OF INTERSTATE 16 IN SOUTHEAST
GEORGIA. SLIGHT CHANCES OF SHOWERS ARE POSSIBLE AHEAD OF THE
FRONT...FOLLOWED BY CHANCES OF SHOWERS AS THE FRONT STALLS JUST
SOUTH OF THE AREA MONDAY NIGHT. PRECIP COVERAGE SHOULD REMAIN
HIGHEST IN NORTHERN AREAS THROUGH THE OVERNIGHT PERIOD. LOW TEMPS
WILL BE WARMER THAN THE PREVIOUS NIGHT...IN THE UPPER 40S NORTH TO
LOW/MID 50S IN SOUTHEAST GEORGIA.
TUESDAY...HIGH PRESSURE WILL WEDGE SOUTHWARD INTO THE AREA
EARLY...BEFORE A STATIONARY FRONT LIFTS NORTH AS A WARM FRONT DURING
THE AFTERNOON. CHANCES OF SHOWERS WILL BE POSSIBLE NORTH OF THE
FRONT...BEFORE MOST PRECIP SHIFTS TO OUR NORTH TUESDAY NIGHT. HIGH
TEMPS WILL BE LARGELY DEPENDENT ON THE POSITION OF THE WARM FRONT
OVER THE COURSE OF THE DAY. CLOUD COVER AND A FEW SHOWERS WILL ALSO
POSE SOME LIMITING FACTORS AS TO HOW WARM CONDITIONS WILL GET DURING
TYPICAL PEAK HEATING HOURS. AT THIS TIME...HAVE MAINTAINED TEMPS IN
THE LOW/MID 60S FOR MOST AREAS...WITH PERHAPS SOME LOW 70S FOR
LOCATIONS SOUTH OF INTERSTATE 16 IN SOUTHEAST GEORGIA.
WEDNESDAY...STRONG WARM AIR ADVECTION WILL OCCUR AS SOUTHERLY FLOW
STRENGTHENS OVER THE SOUTHEAST UNITED STATES WELL AHEAD OF A COLD
FRONT APPROACHING FROM THE WEST LATE WEDNESDAY NIGHT. BREAKS IN
CLOUD COVER AS WELL AS SOME COMPRESSIONAL HEATING SUPPORT THE
WARMEST TEMPS OF THE WEEK...WITH HIGH TEMPS IN THE MID/UPPER 70S
OVER MOST AREAS BEFORE THE ONSET OF SHOWERS LATE WEDNESDAY
AFTERNOON/EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COLD FRONT WILL APPROACH WESTERN ZONES WEDNESDAY NIGHT WITH MAINLY
SHOWERS. HOWEVER...STRONG FORCING WILL BE ASSOCIATED WITH THE
FRONT...SUPPORTING THE NEED FOR A FEW THUNDERSTORMS OVER INLAND
AREAS EARLY WEDNESDAY NIGHT. THE COLD FRONT WILL THEN CONTINUE TO
PUSH THROUGH THE AREA EARLY THURSDAY...WITH GREATEST COVERAGE OF
SHOWERS THURSDAY MORNING AND AFTERNOON. MOST SHOWERS WILL THEN SHIFT
OFFSHORE THURSDAY NIGHT INTO EARLY FRIDAY AS COOLER HIGH PRESSURE
BUILDS BEHIND THE FRONT. THURSDAY AND FRIDAY NIGHT LOW TEMPS SHOULD
BE THE COOLEST OF THE WEEK...IN THE MID/UPPER 30S. AFTERNOON HIGHS
WILL ONLY BE IN THE LOW/MID 50S INTO THE WEEKEND. HIGH PRESSURE
SHOULD PREVAIL THROUGH THE WEEKEND...BUT THERE ARE INDICATIONS THAT
SOME SHOWERS COULD DEVELOP MAINLY ALONG THE COAST AS A SFC LOW
DEVELOPS OFFSHORE AND DEEPENS WHILE LIFTING TO THE NORTH/NORTHEAST.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
IFR CONDITIONS WILL PREVAIL AT THE TERMINALS THROUGH THE AFTERNOON
WITH LIGHT RAIN/DRIZZLE PERSISTING. CEILINGS SHOULD DETERIORATE
FURTHER AFTER 23Z...LOWERING TO LIFR LEVELS AT BOTH TERMINALS.
VISIBILITIES WILL LOWER LATE TONIGHT AS WELL...DUE TO STRATUS
BUILD DOWN AND/OR FOG FORMATION. AT THIS TIME...GUIDANCE APPEARS
TO SHOW HIGHER PROBABILITIES OF DENSE FOG AT KSAV...SO HAVE
INCLUDED A TEMPO GROUP FROM 08-12Z AT THAT TERMINAL WITH FURTHER
REDUCED VISIBILITIES/CEILINGS. GRADUAL IMPROVEMENT IS GENERALLY
EXPECTED AFTER ABOUT 15Z MONDAY AS SOMEWHAT DRIER AIR FILTERS IN
ON A WEST-NORTHWEST FLOW...BUT CONDITIONS WILL LIKELY REMAIN
BELOW VFR THROUGH THE END OF THE FORECAST PERIOD AT 18Z.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS ARE EXPECTED MONDAY
AFTERNOON. A BACKDOOR COLD FRONT COULD PRODUCE A ROUND OF FLIGHT
RESTRICTIONS MONDAY NIGHT AND THEN AGAIN ON TUESDAY AS IT RETURNS
AS AS WARM FRONT. VFR CONDITIONS SHOULD RETURN ON
WEDNESDAY...BEFORE ANOTHER ROUND OF FLIGHT RESTRICTIONS OCCURS
WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT SHIFTS THROUGH THE
AREA.
&&
.MARINE...
HIGH PRESSURE WILL WEDGE INLAND ON TODAY WHILE A COASTAL TROUGH
LIFTS NORTH ALONG THE SOUTHEAST COAST. A STRONG PRESSURE GRADIENT
BETWEEN THESE TWO FEATURES IS FORECAST TO DECREASE WITH A MUCH
LIGHTER GRADIENT BY LATER TODAY AND TONIGHT. IT WILL DIFFICULT TO
TURN DIRECTIONS AWAY FROM A NORTHERLY COMPONENT GIVEN THE STABLE
CHILLY SHELF WATERS BUT THEY COULD BECOME MORE NW TO N LATER
TONIGHT. SEAS SHOULD FALL BELOW 5 FT TONIGHT EXCEPT OVER OUTER
GEORGIA WATERS WHERE ELEVATED SEAS WILL MAINTAIN ADVISORY LEVELS
UNTIL AT LEAST LATE IN THE NIGHT. STRATUS CLOUDS COULD LOWER TO
1-2 HUNDRED FT OVER COOL STABLE WATERS ALONG THE LAND/SEA
INTERFACE OVERNIGHT. WE INCLUDED AREAS OF FOG AS VSBYS LIKELY WILL
BE LOWERED AT LEAST SOMEWHAT BY LOWER CEILINGS.
MONDAY AND TUESDAY...WINDS/SEAS SHOULD REMAIN BELOW ADVISORY LEVELS
AS A COLD FRONT APPROACHES FROM THE NORTH ON MONDAY...THEN STALLS
JUST SOUTH OF THE COASTAL WATERS MONDAY NIGHT. HOWEVER WE COULD SEE
WINDS BETWEEN 15-20 KT OVER NORTHERN SC WATERS LATE. THE FRONT WILL
THEN LIFT BACK NORTH AS A WARM FRONT TUESDAY AFTERNOON WITH DEWPTS
THAT APPROACH THE UPPER 50S TO AROUND 60 LATE IN THE DAY. SEA FOG
COULD BE AN ISSUE...MAINLY OVER SOUTHERN WATERS TUESDAY NIGHT.
WEDNESDAY THROUGH SATURDAY...GREATEST CHANCES OF SEA FOG WILL BE
POSSIBLE ON WEDNESDAY AND THURSDAY AS DEEP MOISTURE ADVECTS OVER
COOLER WATERS AHEAD A COLD FRONT. WINDS AND SEAS WILL ALSO GRADUALLY
INCREASE/BUILD AHEAD OF THE FRONT...LIKELY SUPPORTING THE NEED FOR
SOLID SMALL CRAFT ADVISORIES THURSDAY EVENING INTO FRIDAY AS THE
COLD FRONT SHIFTS OVER THE WATERS AND IS FOLLOWED BY COLDER HIGH
PRESSURE. CONDITIONS SHOULD SLOWLY IMPROVE LATE WEEKEND AS THE
PRESSURE GRADIENT BECOMES MORE RELAXED OVER COASTAL WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ350-
352-354.
SMALL CRAFT ADVISORY UNTIL 5 AM EST MONDAY FOR AMZ374.
&&
$$
SYNOPSIS...
NEAR TERM...JAQ
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...JAQ/DPB
MARINE...JAQ/DPB
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1113 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 637 AM CST SUN MAR 1 2015
OVERALL A FEW SMALL TWEAKS TO THE FORECAST WERE MADE. RADAR
RETURNS SUGGEST THAT SNOW BAND COULD SHIFT A LITTLE FURTHER NORTH
TODAY. AS SUCH INCREASED POPS FURTHER NORTH OF WHERE THEY WERE
BEFORE. TOTAL SNOWFALL AMOUNTS REMAIN THE SAME AS EARLIER. SOME
PATCHY DENSE FOG HAS DEVELOPED ACROSS THE AREA. THIS SEEMS TO BE
LIMITED TO THE MISSISSIPPI RIVER VALLEY. THE FOG SHOULD BURN OFF
THIS AM. OTHER THAN THAT FORECAST LOOKS TO BE ON TRACK.
&&
.SYNOPSIS...
ISSUED AT 149 AM CST SUN MAR 1 2015
VERY MINOR SNOWFALL ACCUMULATIONS YESTERDAY WERE
REPORTED...ESPECIALLY SOUTH OF INTERSTATE 80. REGIONAL RADAR THIS
MORNING DEPICTS MOST OF THE SNOW SOUTH AND EAST OF OUR AREA. WITH
LIGHT FLURRIES FALLING ACROSS THE CWA. SATELLITE AND ASOS STATIONS
REPORTED LOW CLOUDS MOVING THROUGH IA AND TOWARDS OUR AREA. THIS
SHOULD HELP TO WARM TEMPS OVERNIGHT AND ALLEVIATE POSSIBLE DENSE
FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 149 AM CST SUN MAR 1 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM ARE THE CHANCES OF SNOW
TODAY AS A SECOND WAVE TRANSVERSES THE FLOW. CHANCES ARE LOW FOR
ACCUMULATING SNOW EXCEPT FOR FAR SOUTHERN AREAS OF THE CWA. TOTAL
SNOWFALL TODAY SHOULD BE LESS THAN AN INCH OVERALL.
A SHORTWAVE EMBEDDED IN THE DEEPER TROF WAS LOCATED OVER W KS AND
SW NE. THIS VORT IS QUICKLY ADVECTING THROUGH THE FLOW TOWARDS THE
AREA. SINCE MOST OF THE VORT IS PARALLEL TO THE FLOW...OVERALL
HEIGHT FALLS AND SUBSEQUENT FORCING WILL BE WEAK AND LIMITED TO A
SMALL AREA. THE MAJORITY OF RUNS TAKES THIS OVER FAR SOUTHERN
PORTIONS OF THE CWA. THIS ALONG WITH HRRR AND WRFARW AND WRFNMM
MODEL REFLECTIVITY...SUGGEST THAT OVERALL ADDITIONAL SNOW WILL BE
LIGHT AND LIMITED TO FAR SOUTHERN AREAS OF THE CWA. CURRENT RADAR
SUGGESTS THAT MOST OF THE SNOW WILL LIKELY AFFECT FAR SE ZONES AND
CITIES LIKE MQB. HPC QPF SEEMS TO BE OVERDONE FOR THE NEXT 12
HOURS...AS SUCH LOWERED THE QPF. THIS GIVES MQB ANOTHER 0.6 INCHES
OF SNOW TODAY. BELIEVE THAT MOST OF THE PRECIP WILL BE OUT OF THE
CWA BY 18Z.
AS FAR AS TEMPS...WE STILL END UP WITH BELOW AVERAGE TEMPS. WENT
WITH RAWBLEND FOR THE HIGHS TODAY. CLOUDS SHOULD CLEAR AND WE
SHOULD END UP WITH SUN FOR THE SUNSET.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 149 AM CST SUN MAR 1 2015
THE MAIN ISSUE IN THE EXTENDED WILL BE THE MIXED PCPN TYPE EVENT
MONDAY NIGHT INTO TUESDAY. THIS EVENT IS LIKELY TO CONTAIN A FULL
SHIFT FROM LIGHT SNOW TO MODERATE SNOW...TO SLEET...TO FREEZING
RAIN...TO RAIN...THEN FINALLY A LIGHT MIX OF RAIN AND SNOW BEFORE
ENDING. WHILE THIS SOUNDS RATHER SCARY AT FACE VALUE WITH RESPECT TO
HAZARDS...IT APPEARS THE TRANSITION FROM SNOW TO FREEZING TO RAIN
SHOULD BE A QUICK ONE DURING THE 3 AM TUESDAY TO 9 AM TUESDAY
PERIOD. THUS...ACCUMULATIONS OF ICING WILL BE LIMITED AND ARE MOST
LIKELY GOING TO WARRANT AN ADVISORY VS A WARNING.
SNOW SHOULD BEGIN TO BECOME WIDESPREAD AFTER MIDNIGHT MONDAY
NIGHT...SO WILL BEGIN TO RAMP UP POPS TO LIKELY AT THAT TIME. THE
INITIAL PHASE OF PCPN SHOULD BE SNOW AT ANY LOCATION...AND WITH
WIDESPREAD ACTIVITY SPREADING NORTHWARD AROUND 3 AM...WE SHOULD SEE
AN INCH OR TWO OF SNOW ACCUMULATION OVER THE NORTHERN 1/2 TO 2/3RD.
IN THIS TIME TIME FRAME...THE SOUTH WILL BEGIN TO WARM
ALOFT...RESULTING IN SLEET MIXING IN WITH SNOW...THEN CHANGING TO A
LIGHT MIX OF FREEZING RAIN AND SLEET TOWARD 6 AM. THUS...IT APPEARS
THAT A LIKELY ADVISORY WOULD BEGIN NO EARLIER THAN 06Z...AND COULD
HOLD OFF TIL 3 AM. THE FREEZING RAIN THREAT SHOULD SPREAD
NORTH...ALL THE WAY UP TO AROUND HIGHWAY 20 BY TUESDAY MORNING
AROUND 9 AM...HOWEVER...IN ANY ONE LOCATION...THE GRADUAL RISE IN
TEMPERATURES AND DEWPOINTS SHOULD LIMIT THE DURATION OF FREEZING
RAIN TO AROUND 5 HOURS OR LESS...AND IN THE NORTH...WHERE
TEMPERATURES REMAIN NEAR FREEZING THE LONGEST...THE WINDOW IS
FURTHER LIMITED BY ANY RAIN CHANGING BACK TO SNOW BY EARLY
AFTERNOON. THUS...I FORESEE AN ADVISORY RUNNING FROM LATE MONDAY
NIGHT THROUGH NOON TUESDAY...BUT THIS IS TOO EARLY TO ISSUE ON A
MARGINAL EVENT...AND WILL EXPECT TO SEE THIS COME OUT ON FUTURE
SHIFTS TODAY OR TONIGHT.
SNOW ON THE BACKSIDE OF THE COLD FRONT TUESDAY AFTERNOON APPEARS
VERY LIGHT...AS DRY AIR AGGRESSIVELY SWEEPS IN FROM THE WEST. IN
FACT...I HAVE REMOVED POPS TUESDAY NIGHT ALL TOGETHER...AND LOWERED
AFTERNOON TO CHANCE AREA WIDE. QPF OVER THE ENTIRE EVENT APPEARS
TO BE IN THE 0.20 TO 0.50 RANGE...WITH SOME LOCALIZED HIGHER
AMOUNTS THROUGH SHOWERS IN THE MID MORNING HOURS. WHILE TEMPERATURES
TUESDAY SHOULD SURGE ABOVE FREEZING...THIS WILL NOT REMOVE OUR SNOW
PACK...AND ANY RAIN WILL BE ABSORBED INTO THIS SNOW PACK...SO NO
RUNOFF ISSUES ARE EXPECTED.
AFTER OUR BRIEF WARM UP TUESDAY...THE COLD WILL BE BACK FOR TUESDAY
NIGHT THROUGH THURSDAY NIGHT. OUR FORECAST IS CONFIDENTLY DRY...AND
COLD AS THE GUIDANCE BLEND INITIALIZED WITH. FRIDAY STILL
INDICATES A TRANSITION TO MORE ZONAL FLOW...AND WITH A CLIPPER
EXPECTED TO PASS TO THE NORTH OF IOWA...WE SHOULD BE WARM
SECTORED...AND SEE TWO RELATIVELY MILD DAYS( 30S TO LOWER 40S) FRIDAY
AND SATURDAY.
ERVIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1109 AM CST SUN MAR 1 2015
VFR CONDITIONS FOR AT LEAST THE NEXT 24 HOURS. ANOTHER ARCTIC HIGH
PRESSURE SYSTEM WILL MOVE IN FROM THE NORTHERN PLAINS. SKIES WILL
CONTINUE TO CLEAR THIS AFTERNOON WITH LIGHT SOUTHWEST WINDS SHIFTING
TO THE NORTHWEST AT 5 TO 10 KTS BY DUSK...CONTINUING THEN INTO MID
DAY MONDAY.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...GIBBS
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...ERVIN
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
341 PM CST SUN MAR 1 2015
...UPDATED SHORT TERM SECTION...
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 340 PM CST SUN MAR 1 2015
SOUTHWEST KANSAS FOUND ITSELF DOWNSTREAM OF WEAK SHORTWAVE RIDGING
AS A BIG UPPER LOW REMAINED ANCHORED OFF THE COAST OF SOUTHERN
CALIFORNIA. REMNANT COLD CANADIAN AIR REMAINED LOCKED IN PLACE WITH
ALMOST NO ADVECTION OCCURRING THANKS TO VERY LIGHT WINDS. THERE IS
SOME LIGHT NORTH-NORTHEAST WINDS AROUND 850MB, WHICH WILL CONTINUE
TO PUSH SOME LOWER RH AIR TOWARD SOUTHWEST KANSAS...AIDING IN THE
EVENTUAL SCOURING OUT OF STRATUS. WE WILL STILL SEE SOME MID AND
HIGH LEVEL CLOUD AROUND THROUGH THE EVENING AND OVERNIGHT, THOUGH,
AS WE REMAIN IN THE MOIST SOUTHWEST FLOW REGIME IN THE MID LEVELS.
TEMPERATURES WILL FALL IN TO THE LOWER 20S BY 09-12Z MONDAY MORNING,
AND WITH THE VERY LIGHT WINDS NEAR THE SURFACE RIDGE AXIS, WE WILL
LIKELY SEE SOME LIGHT FOG DEVELOPMENT, SO WE HAVE INCLUDED SOME
PATCHY FREEZING FOG ACROSS THE SOUTHERN COUNTIES (MAINLY SOUTH OF
THE ARKANSAS RIVER). DENSE FOG DEVELOPMENT, HOWEVER, APPEARS
UNLIKELY.
DURING THE DAY MONDAY, WE WILL SEE THE SOUTHERN CALIFORNIA UPPER LOW
MOVE SLOWLY EAST, AND THIS WILL LEAD TO LOW LEVEL DEVELOPMENT OF A
LEE TROUGH, BUT RIGHT UP AGAINST THE MOUNTAINS. THE CHANGE IN
PRESSURE GRADIENT WILL LEAD TO AN INCREASE IN SOUTH WINDS BY MIDDAY,
BUT THE WINDS WILL STILL BE COLD, WITH THE TRAJECTORIES COMING FROM
AROUND THE REMNANT SURFACE HIGH. AS A RESULT, WE HAVE BACKED OFF ON
TEMPERATURES A FEW DEGREES, ONLY EXPECTING HIGHS IN THE 35 TO 37F
RANGE AS A GENERAL RULE (COOLEST IN CENTRAL/SOUTH CENTRAL KANSAS).
ELKHART SHOULD TOUCH LOWER 40S BY LATE IN THE AFTERNOON CLOSER TO
THE LEE TROUGH AND SLIGHTLY WARMER LOWER TROPOSPHERE.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CST SUN MAR 1 2015
STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY
NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS
NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT
EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING
INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO
THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE
AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG
NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES
FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF
THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY
LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW
ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE
MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS
THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO
DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE
AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST
KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE
MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT
AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR
TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID
30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE
AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS
TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS
TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED
WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS
AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS
THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN
THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS
LOOK TO DIP INTO THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 36 34 43 / 10 10 10 10
GCK 22 37 33 39 / 10 10 10 10
EHA 21 41 36 43 / 10 10 10 10
LBL 22 40 35 45 / 10 10 10 10
HYS 19 34 33 38 / 0 10 10 10
P28 19 35 33 47 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
243 PM CST SUN MAR 1 2015
...UPDATED LONG TERM SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 240 PM CST SUN MAR 1 2015
STRONG SOUTHERLY WINDS WILL BE FELT ACROSS WESTERN KANSAS MONDAY
NIGHT WITH AN AREA OF SURFACE LOW PRESSURE LOCATED ACROSS
NORTHEASTERN COLORADO. THIS AREA OF LOW PRESSURE WILL SHIFT
EASTWARD AS TIME PROGRESSES DUE TO AN UPPER LEVEL SHORTWAVE MOVING
INTO THE ROCKIES. THIS SHORTWAVE WILL CONTINUE TO MOVE EAST INTO
THE PLAINS TUESDAY PUSHING A STRONG SURFACE COLD FRONT THROUGH THE
AREA WITH AN ARCTIC DOME OF HIGH PRESSURE BEHIND IT. STRONG
NORTHERLY WINDS ARE ANTICIPATED BEHIND IT WITH TEMPERATURES
FALLING ACROSS THE AREA IN THE AFTERNOON. LOWER AND MID LEVELS OF
THE ATMOSPHERE BECOME SATURATED TUESDAY NIGHT INTO WEDNESDAY
LEADING TO A SLIGHT CHANCE OF SNOW SHOWERS. LITTLE TO NOW
ACCUMULATION IS EXPECTED AT THIS TIME. OTHERWISE SKIES WILL BE
MOSTLY CLOUDY. WINDS SHIFT BACK TO THE SOUTH BY WEDNESDAY NIGHT AS
THE AREA OF HIGH PRESSURE MOVES EAST OF THE AREA. CLOUDS WILL ALSO
DECREASE IN COVERAGE WEDNESDAY NIGHT AS DRIER AIR MOVES INTO THE
AREA. THE REMAINDER OF THE EXTENDED LOOKS DRY AS A RIDGE OF HIGH
PRESSURE BUILDS ACROSS THE WESTERN UNITED STATES PLACING NORTHWEST
KANSAS IN A NORTHWEST FLOW ALOFT. MODELS SUGGEST A SHORTWAVE
MOVING SOUTHEAST THROUGH THIS FLOW TOWARDS THE END OF THE WEEK BUT
AS OF NOW THIS FEATURE ONLY INCREASES CLOUD COVER SLIGHTLY. AS FOR
TEMPERATURES, LOWS MONDAY NIGHT REMAIN WARM AND IN THE LOW TO MID
30S. A LARGE RANGE OF TEMPERATURES ARE EXPECTED TUESDAY DUE TO THE
AFOREMENTIONED COLD FRONT MOVING THROUGH EARLY IN THE DAY. HIGHS
TUESDAY LOOK TO RANGE FROM THE MID 30S ACROSS WEST CENTRAL KANSAS
TO UPPER 40S ACROSS SOUTH CENTRAL KANSAS. A COLD DAY IS EXPECTED
WEDNESDAY WITH LOWS IN THE TEENS WEDNESDAY AND THURSDAY MORNINGS
AND HIGHS IN THE UPPER 20S IN THE AFTERNOON. A WARMING TREND IS
THEN EXPECTED AS WE HEAD INTO THE END OF THE WEEK WITH HIGHS IN
THE 40S THURSDAY AND AROUND THE MID 50S FRIDAY AND SATURDAY. LOWS
LOOK TO DIP INTO THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 18 36 34 43 / 10 10 10 10
GCK 18 37 33 39 / 10 10 10 10
EHA 20 41 36 43 / 20 10 10 10
LBL 23 40 35 45 / 10 10 10 10
HYS 17 34 33 38 / 10 20 10 10
P28 20 35 33 47 / 10 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1146 AM CST SUN MAR 1 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST SUN MAR 1 2015
WEAK 30 DBZ RADAR ECHOES WERE NOT PRODUCING PRECIPITATION ACROSS THE
FORECAST AREA THIS MORNING. THIS IN COMBINATION WITH THE
SIGNIFICANTLY TONED DOWN QPF OUTPUT FROM THE HRRR AND ARW/NMM MODEL
RUNS PROMPTED DROPPING THE WINTER WEATHER ADVISORY FOR ALL OF OUR
COUNTIES. THE THERMODYNAMIC PROFILES WERE NOT SEEN AS STRONGLY
SUPPORTIVE FOR FREEZING DRIZZLE AS WELL, IN LACKING A SHEAR LAYER
ABOVE OR NEAR THE TOP OF THE SATURATED LAYER. AS A RESULT, THE REST
OF THE MORNING WILL LIKELY BE COLD AND CLOUDY WITH STRATUS REMAINING
OVER MUCH OF THE AREA, WITH POSSIBLY SOME AREAS OF FREEZING FOG
DEVELOPING MAINLY FARTHER SOUTH ACROSS THE STATE LINE WHERE DEW POINT
DEPRESSIONS HAVE BEEN THE SMALLEST.
SLIGHT POPS FOR LATER THIS EVENING WERE ALSO REMOVED EVEN FROM THE
EXTREME WESTERN COUNTIES. ANY PRECIPITATION FROM WEAK ENHANCED LIFT
ACROSS THE MOUNTAIN RANGE AS THE NEXT SYNOPTIC SYSTEM APPROACHES
COLORADO LOOKS TO BE CONFINED TO THE WEST OF OUR AREA TONIGHT.
WITH NO SIGNIFICANT AIRMASS CHANGE, THE LOWS SUNDAY NIGHT SHOULD
BE SIMILAR, IN THE UPPER TEENS TO LOWER 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 422 AM CST SUN MAR 1 2015
THE MEDIUM RANGE MODELS ARE BEGINNING TO SHOW A TRANSITION FROM THE
QUASI-STATIONARY UPPER LEVEL TROUGH OVER CENTRAL AND WESTERN NORTH
AMERICA TO A SOMEWHAT MORE PROGRESSIVE PATTERN AS THIS WEEK UNFOLDS.
AN UPPER LEVEL SHORTWAVE RIDGE OVER THE CENTRAL HIGH PLAINS WILL BE
MOVING EAST ON MONDAY AS AN UPPER LEVEL TROUGH OVER THE WESTERN
STATES MOVES EAST. SURFACE HIGH PRESSURE WILL BE WEAKENING ITS GRIP
ON THE CENTRAL HIGH PLAINS AS THE CENTER OF THE HIGH PRESSURE MOVES
EAST INTO THE OHIO VALLEY AND LOW PRESSURE DEVELOPS OVER COLORADO
DURING THE DAY MONDAY. LOW LEVEL WARM ADVECTION WILL INCREASE AS
SOUTHERLY LOW LEVEL FLOW INCREASES OVER WESTERN KANSAS. SOME LIGHT
SHOWERS WILL BE POSSIBLE OVER CENTRAL KANSAS BUT MOISTURE PROFILES
IN THE MODEL SOUNDINGS SUGGEST ANY PRECIPITATION WILL PREDOMINANTLY
BE IN THE FORM OF DRIZZLE.
ON TUESDAY, THE UPPER LEVEL TROUGH WILL BE MOVING OUT INTO THE
CENTRAL CONUS. THIS WILL DRIVE A STRONG COLD FRONT SOUTH ACROSS
WESTERN KANSAS. TIMING OF THIS FRONT WILL BE CRITICAL FOR HIGH
TEMPERATURES DURING THE DAY AS TEMPERATURES WILL BE FALLING BEHIND
THE FRONT. THERE COULD ALSO BE A PERIOD OF LIGHT SNOW OR FLURRIES IN
THE STRONG COLD ADVECTION ZONE BEHIND THE FRONT. MODEL QPF FIELDS
ARE NOT SHOWING MUCH IN THE WAY OF PRECIPITATION BEHIND THE FRONT
LATE TUESDAY INTO WEDNESDAY MORNING BUT GIVEN THE UPPER LEVEL
TROUGHINESS MOVING OVER THE REGION DURING THAT TIME PERIOD, WILL
HOLD ON TO SOME SLIGHT CHANCE POPS FOR SNOW. COLDER AIR SETTLES BACK
INTO THE HIGH PLAINS FROM LATE TUESDAY THROUGH WEDNESDAY AS WELL
WITH HIGHS ON WEDNESDAY IN THE UPPER 20S TO AROUND 30.
LATER IN THE WEEK, THE UPPER TROUGH WILL MOVE EAST OF THE PLAINS
WITH NORTHWEST FLOW AND INCREASING 500 MILLIBAR HEIGHTS OVER WESTERN
KANSAS. THIS WILL BRING DRY CONDITIONS WITH TEMPERATURES WARMING
BACK INTO THE 50S BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1137 AM CST SUN MAR 1 2015
CEILINGS/VISIBILITY AROUND MIDDAY HAVE SLOWLY INCREASE TO THE MVFR
CATEGORY, WHICH IS EXPECTED TO CONTINUE THROUGH THE LATE AFTERNOON
HOURS. SOME DRIER AIR WILL BE WORKING SOUTH IN THE LOW LEVEL LATE
IN THE DAY, AS IS SUGGESTED BY THE NAM12 AND HRRR MODELS,
RESULTING IN VFR CONDITIONS. VFR IS THEN EXPECTED THROUGH THE
NIGHT AND INTO THE FIRST PART OF THE DAY MONDAY WITH CONTINUED
VERY LIGHT WINDS AT 6 KNOTS OR LESS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 18 38 35 / 10 10 10 10
GCK 31 18 40 34 / 10 10 10 10
EHA 33 20 45 37 / 10 20 10 10
LBL 34 23 43 37 / 10 10 10 10
HYS 36 17 37 33 / 10 10 20 20
P28 32 20 37 34 / 20 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...GERARD
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1137 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1136 AM CST SUN MAR 1 2015
For the 18z TAFs, scattered to broken MVFR cigs will persist
through the day as the storm system exits east of the area. As
surface high pressure moves over the area tonight into Monday,
northwesterly winds will veer toward the northeast and eventually
to the southeast by the end of the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 AM CST Sun Mar 1 2015
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 257 AM CST SUN MAR 1 2015
Expansive upper trough axis continues to rotate off the CA coast
while weaker embedded areas of vorticity were lifting north and
east towards Colorado and Kansas. A stronger shortwave trough was
observed shifting southeast towards the northern plains later this
morning. Lows were starting out in the teens and lower 20s with
scattered light snow or flurries across northeast Kansas.
Main highlight of the forecast is expected snowfall from sunrise
through noon today. As the upper trough dives southeast, mid level
forcing is enhanced within the embedded vorticity maxima tracking
east over the state. Timing of this feature and area of weak
frontogenesis will place the snow band near the Interstate 70
corridor based on latest runs of the RAP and NAM or just south near
the Intestate 35 corridor based on the 4-KM WRF and HRRR solutions.
Duration of light snow is quick as well with lift diminishing
eastward by mid afternoon today. Main changes for the forecast
package were to remove precip chances for far north central Kansas
as dry air aloft increases after sunrise. Also adjusted highest
chances for snowfall in the above mentioned areas where an
additional one half to one inch of snow is expected. Will maintain
the advisory ongoing until noon and have the following shift remove
counties as the snowfall exits.
With the snowfall exiting quicker and the possibility of higher
cloud bases, increased highs today a few degrees in the lower to
possibly middle 30s. Weak high pressure shifts southeast this
evening as skies become partly to mostly cloudy. Calm winds and snow
covered ground hold lows in the upper teens to lower 20s.
.LONG TERM...(Monday through Saturday)
Issued at 257 AM CST SUN MAR 1 2015
For Monday models prog the mid level shortwave ridge to be over
the area with low level moisture remaining to the south of the
forecast. So with no real forcing expected to affect the area,
have a dry forecast through the day. With some cloud cover and the
surface ridge possibly influencing eastern KS still, have highs
only reaching the mid and upper 30s.
Monday night and Tuesday appear to be the next opportunity for
precip as low level return flow advects moisture north while a
shortwave kicks out from the base of the mid level trough over the
southwest. However chances appear to remain limited. The model
consensus shows the stronger Q vector convergence and PV anomaly
passing just north of the forecast area while a dry slot moves
into eastern KS by Tuesday morning. With the deeper moisture over
far eastern KS, have kept the higher POPs across the east during
the early morning hours Tuesday as the shortwave passes by. Prior
to this there could be some drizzle develop and spread northeast
through the area in response to the stronger low level moisture
return. Depending on temps, there could be a brief period of light
freezing drizzle. However I expect this to be short lived mainly
in the evening as warm air advection should cause temps to rise
through the night. Therefore any accumulations should be very
minor. Another arctic ridge of high pressure is set to move
through the forecast area Tuesday with the GFS trending a little
faster with the frontal passage. However with the dry slot in
place as the front moves through and upper level forcing likely to
the northeast of the forecast area, the front may move through
mostly dry through the early afternoon. The forecast anticipates
falling temps through the afternoon as cold air moves in behind
the front. But for the most part think that any precip on Tuesday
is likely to be out ahead of the front and in the form of rain.
There are still weak indications of some convective instability
Tuesday morning. Because of this have kept a mention for thunder
across east central KS. Lows Monday night are forecast to occur
early in the evening while highs Tuesday are likely to be measured
late in the morning.
Tuesday night may be the last chance for precip through the rest
of the week. There remains some indication for some mid level
frontogenesis along with enough moisture for mid level saturation.
The NAM is most bullish with this idea developing several
hundredths of precip. While less impressive, the ECMWF also spits
out some very light precip. Because of this have continued with a
slight chance for snow Tuesday night. However would not anticipate
the snow amounting to very much if at all.
The upper level trough axis is progged to finally move east of the
forecast area Wednesday night. But with dry air moving in with the
arctic airmass on Tuesday, precip chances Wednesday and Wednesday
night look to be less than 20 percent due to to much dry air.
Wednesday is shaping up to be another cold day with lows in the
teens and highs in the 20s.
Thursday through Saturday continues to look dry with moderating
temps as models keep a dry northwest flow over the central plains.
By Friday, highs are expected to be in the 50s. This could be a
little conservative with the GFS and ECMWF showing 925 MB temps
warming to between +5 and +10C. For now stayed with the model
consensus and have highs in the lower 50s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1134 AM CST SUN MAR 1 2015
For the 12z TAFs, scattered to broken MVFR cigs will persist through
the day as the storm system exits east of the area. As surface high
pressure moves over the area tonight into Monday, northwesterly winds will
veer toward the northeast and eventually to the southeast by the end
of the TAF period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST today FOR KSZ058-059.
&&
$$
SHORT TERM...Bowen
LONG TERM...Wolters
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS WICHITA KS
1027 AM CST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1027 AM CST SUN MAR 1 2015
UPDATED PRECIPITATION CHANCES THROUGH THE EARLY PART OF THE
AFTERNOON. WHILE GUIDANCE IS NOT INDICATING MUCH...THE EARLIER
RUNS OF THE HRRR SEEMED TO DO THE BEST FOR CURRENT RADAR
INDICATIONS AND HAVE TRIED TO FOLLOW THAT FOR THE BEST TRENDS.
THINK THAT THE UPPER JET DYNAMICS WILL KEEP SOME LIFT AROUND INTO
THE EARLY AFTERNOON HOURS...AT LEAST OVER SOUTHERN AND
SOUTHEASTERN KANSAS. THIS WILL PRODUCE A WINTRY MIX OF FREEZING
RAIN/SLEET AND SNOW. THIS WILL CAUSE TRAVEL IMPACTS AND THUS HAVE
EXTENDED THE WINTER WEATHER ADVISORY UNTIL 20Z FOR MUCH OF THE
AREA...CLEARING OUT CENTRAL KANSAS COUNTIES WHERE THE
PRECIPITATION HAS ENDED. WILL PLAN TO CLEAR THE ADVISORY FROM WEST
TO EAST AS THE PRECIPITATION ENDS AND/OR EXTEND IF NEEDED IF THE
WINTRY WEATHER PERSISTS LONGER THAN 20Z. AT THIS TIME FEEL THAT
THE BEST CHANCE FOR THAT OCCURRING WOULD BE OVER SOUTHEAST
KANSAS...EXPECT CHANCES TO DIMINISH OVER SOUTH CENTRAL KANSAS
TOWARDS THE EARLY AFTERNOON HOURS. INCREASED ICE MENTION WITH THE
FREEZING RAIN...BUT ONLY A FEW HUNDREDTHS EXPECTED...ICING HAD
ALREADY OCCURRED AT THE WICHITA FORECAST OFFICE. SLICK ROADWAYS
ARE EXPECTED AS THIS PERSISTS.
BILLINGS WRIGHT
UPDATE ISSUED AT 735 AM CST SUN MAR 1 2015
HAVE MADE UPDATES TO POPS AND WEATHER OVER THE LAST HOUR.
INCREASED PRECIP CHANCES THIS MORNING OVER SOUTH CENTRAL AND SE KS
AS RADAR TRENDS CONTINUE TO SHOW RETURNS BUILDING BACK TO THE
SOUTHWEST. ALSO TOOK OUT MENTION OF FREEZING DRIZZLE AND ADDED
SLEET BASED ON REPORTS AND CURRENT OBS. NOT EXPECTING MUCH IN THE
WAY OF ACCUMULATIONS BUT MAYBE JUST ENOUGH TO KEEP ROADWAYS SLICK.
SO WILL MAINTAIN THE WINTER WEATHER ADVISORY.
LAWSON
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM CST SUN MAR 1 2015
THERE IS A CHANCE FOR A WEAK MID-LEVEL BAND OF SNOW TO DEVELOP OVER
CENTRAL KANSAS INTO EASTERN KANSAS EARLY THIS MORNING...WITH SOME
LIGHT SNOW AND LITTLE ACCUMULATION POSSIBLE...MAINLY NEAR THE
HIGHWAY 50 CORRIDOR. THE MAIN HAZARD FOR THIS MORNING WILL BE
AREAS OF DENSE FREEZING FOG AND PATCHY FREEZING DRIZZLE OVER SOUTH
CENTRAL AND SOUTHEAST KANSAS...WHICH COULD CREATE A LIGHT GLAZE ON
ELEVATED SURFACES AND UNTREATED ROADWAYS ALONG WITH REDUCED
VISIBILITIES TO AROUND ONE QUARTER OF A MILE.
DRY WEATHER IS EXPECTED FOR TONIGHT INTO EARLY MONDAY WITH A
CHANCE OF OF DRIZZLE POSSIBLY DEVELOPING MONDAY AFTERNOON...AS LOW
LEVEL MOISTURE RETURNS NORTHWARD. DAYTIME HIGHS ON MONDAY SHOULD
RISE SOME COMPARED TO SUNDAY`S HIGHS BUT VALUES WILL STILL BE
WELL BELOW NORMAL FOR EARLY MARCH...ESPECIALLY FOR THE SNOW
COVERED AREAS. CHANCES OF RAIN LOOK TO INCREASE FOR EASTERN KANSAS
ON MONDAY NIGHT INTO TUESDAY...WITH A FEW WEAK ELEVATED
THUNDERSTORMS POSSIBLE OVER FAR SOUTHEAST KANSAS. THE ARCTIC COLD
FRONT WILL SURGE SOUTHWARD ACROSS KANSAS DURING THE DAY ON
TUESDAY...WITH FALLING TEMPERATURES IN THE AFTERNOON ACCOMPANIED
BY STRONG GUSTY NORTH WINDS. THE COLDER AIR WOULD CHANGE THE
PRECIPITATION OVER TO A RAIN SNOW MIXTURE FOR CENTRAL KANSAS
TUESDAY AFTERNOON...WITH CHANCES OF LIGHT SNOW FOR TUESDAY NIGHT.
AT THIS JUNCTURE SNOW ACCUMULATIONS ARE LOOKING RATHER LOW FOR
TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 322 AM CST SUN MAR 1 2015
OTHER THAN SOME POSSIBLE LINGERING LIGHT SNOW FOR SOUTHEAST KANSAS
WEDNESDAY MORNING THE BETTER CHANCES SHOULD BE FOR LOCATIONS
SOUTHEAST OF THE AREA. DAYTIME HIGHS ON WEDNESDAY WILL BE WELL BELOW
NORMAL ESPECIALLY FOR SNOW COVER AREAS ACROSS SOUTHERN KANSAS.
OTHERWISE...A DRY WEATHER PATTERN WILL BE IN STORE FOR THURSDAY-
SATURDAY WITH A GRADUAL WARMING TREND FOR FRIDAY INTO THE WEEKEND.
JAKUB
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 530 AM CST SUN MAR 1 2015
MAIN AVIATION CONCERNS WILL BE FOG AND LOW CEILINGS THIS MORNING.
LOCALLY DENSE FOG DEVELOPED OVERNIGHT OVER MAINLY SOUTH CENTRAL
KS. KICT WAS THE MOST AFFECTED WITH LIFR VISIBILITIES AND
CEILINGS. CONDITIONS HAVE STARTED TO SLOWLY IMPROVE OVER THE LAST
HALF HOUR AND WOULD EXPECT THIS TO CONTINUE. HOWEVER...STILL
EXPECTING AT LEAST IFR CONDITIONS THIS MORNING AT KICT-KHUT. SOME
LIGHT SNOW/SLEET IS QUICKLY MAKING ITS WAY ACROSS SOUTH CENTRAL
AND SE KS AND WILL BE OUT OF THE FORECAST AREA IN THE NEXT HOUR.
NOT EXPECTING ANY ACCUMULATION WITH THIS. HIGH PRESSURE IS
EXPECTED TO SETTLE OVER THE AREA LATE THIS AFTERNOON THROUGH THE
OVERNIGHT HOURS WHICH WILL ALLOW VFR CONDITIONS TO MOVE BACK IN.
LAWSON
&&
.FIRE WEATHER...
ISSUED AT 322 AM CST SUN MAR 1 2015
FIRE WEATHER CONCERNS WILL REMAIN VERY LOW FOR THE NEXT SEVERAL DAYS
DUE TO SNOW COVER BLANKETING MUCH OF THE AREA...ALONG WITH RAIN
CHANCES FOR MONDAY NIGHT INTO TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 31 20 35 34 / 50 10 20 30
HUTCHINSON 32 20 34 33 / 30 10 20 30
NEWTON 30 19 34 34 / 70 10 20 30
ELDORADO 30 20 35 34 / 50 10 20 40
WINFIELD-KWLD 31 21 36 35 / 50 10 20 40
RUSSELL 33 18 37 34 / 10 10 20 20
GREAT BEND 33 19 37 34 / 10 10 20 20
SALINA 34 20 36 33 / 20 10 20 30
MCPHERSON 32 19 35 33 / 30 10 20 30
COFFEYVILLE 33 22 37 36 / 40 10 20 60
CHANUTE 31 21 36 35 / 40 10 20 60
IOLA 31 20 36 35 / 50 10 20 60
PARSONS-KPPF 32 22 36 35 / 40 10 20 60
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR KSZ053-
067>072-082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
104 PM EST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1253 PM EST SUN MAR 1 2015
ENDED UP EXTENDING THE WSW AND SPS FOR FREEZING RAIN POTENTIAL TO
11AM THIS MORNING BASED ON THE CURRENT /AT THE TIME/ TEMPERATURES
ACROSS THE CWA...AND REPORTS OF CONTINUED SLICK SPOTS ON AREA
ROADWAYS. TEMPERATURES IN MOST AREAS WITHIN THE WSW OR SPS
CONTINUED TO RISE THROUGHOUT THE MORNING...AND WERE SEVERAL
DEGREES ABOVE FREEZING BY THE EXPIRATION OF THE HEADLINES...SO HAD
NO NEED TO CONTINUE THE WSW OR SPS ANY LONGER. DURING THE INITIAL
EXTENSION OF THE PRODUCTS...ALSO WENT IN AND UPDATED THE WEATHER
IN THE FORECAST TO REFLECT THE POSSIBILITY OF FREEZING RAIN IN
VALLEY LOCATIONS WITHIN THE WSW AREA. THIS HAS SINCE FALLEN OUT OF
THE FORECAST AS WELL.
CURRENTLY...A DECENT BAND OF PRECIPITATION IS CONTINUING ACROSS
THE NORTHERN CWA...AND MOVING INTO THE SOUTHWESTERN CWA. THIS
MATCHES UP WELL WITH THE UPDATED FORECAST FROM A FEW HOURS AGO.
WITH TEMPERATURES WELL ABOVE FREEZING AT THIS POINT...EXPECT ALL
OF THIS PRECIPITATION TO CONTINUE IN THE FORM OF LIGHT RAIN. WILL
BE LOADING IN THE LATEST OBSERVATIONAL DATA AT THE TOP OF THE HOUR
FOR TEMPS...DEW POINTS...AND WINDS...TO MAKE SURE THAT THE NEAR
TERM FORECAST IS ON TRACK WITH THE ONGOING CONDITIONS.
UPDATE ISSUED AT 647 AM EST SUN MAR 1 2015
CONDITIONS ACROSS EASTERN KENTUCKY THIS MORNING FEATURED SOME
SHOWERS DEVELOPING OVER FAR EASTERN KENTUCKY AS THE DEVELOPING LL
JET RESULTED IN THIS DEVELOPMENT. REPORTS OVER NEAR PIKEVILLE THIS
MORNING RELAYED SOME LIGHT FREEZING RAIN REPORTS WITH SOME
SLICKNESS DEVELOPED ON SECONDARY ROADS. GIVEN THE INTENSITY OF THE
RAIN AND THE SATURATED LOWER LEVELS IN THE FAR EAST...SENT OUT AN
FREEZING RAIN ADVISORY FOR THIS. THESE DEEPER VALLEYS IN THE EAST
WILL LIKELY TAKE UNTIL MID MORNING TO MIX OUT. NO REPORTS HAVE
BEEN SEEN IN THE NORTHWEST AND BLUEGRASS REGION AND GIVEN THE
SURGE OF WARM AIR COUPLED WITH THE CONTINUED DEW POINT
DEPRESSIONS WILL CONTINUE TO HIGHLIGHT THIS AREA WITH THE SPS
MENTIONING SOME LIGHT WINTRY WEATHER THIS MORNING. TEMPS SHOULD
ALSO RISE QUITE QUICKLY THIS MORNING AS THE WARMER SOUTHWESTERLY
AIR ADVECTS INTO THE AREA. HAVE SENT OUT A NEW ZFP WITH THE WSW
HIGHLIGHTED.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
CURRENT CONDITIONS ACROSS KENTUCKY AS OF 0820Z HAVE CONTINUED
NORTHEAST MOVEMENT OF CLOUD COVER AND SOME RETURNS ON THE MOSAIC.
AT THIS POINT...THIS PSEUDO WARM FRONT CONTINUES TO SLOWLY LIFT
NORTH THROUGH KY WITH THE BULK OF THE PRECIP WELL TO THE NORTH
ACROSS THE OH RIVER. IN FACT...THE ONLY MEASURABLE PRECIP AT THE
MESONET SITES WAS WELL NORTH OF I-64 IN CENTRAL KENTUCKY. WHILE
SURFACE AIR TEMPS CONTINUE TO COOL ACROSS THE AREA...MOST LIKELY
DUE TO EVAPORATIVE COOLING MORE THAN DIURNAL TRENDS...IT IS TO BE
NOTED THAT THE ROAD TEMPS REMAIN UP IN THE MID 30S THROUGH THE
MORNING SO FAR. THE MOISTURE MOVING IN OVERHEAD IS HAVING QUITE A
TOUGH TIME SATURATING THE LOWER LEVELS. FOR THIS...WILL CONTINUE
WITH THE SPS. THE HRRR AND NAM MODELS DO HAVE PRECIP FURTHER
DEVELOPING IN THE NORTHEAST PORTIONS OF KY IN THE 09Z TO 12Z
HOURS. IF THIS AREA DOES DEVELOP AS ROBUST AS IT IS...THERE MAY BE
A 1 TO 2 HOUR PERIOD WHERE A HUNDREDTH OR TWO OF FREEZING PRECIP
MAY FALL. HOWEVER...TIMING HERE WILL BE AN ISSUE AS WELL AS TEMPS
WILL BEGIN TO REBOUND AND WARM UP AFTER DAWN. NEEDLESS TO
SAY...QUITE A TEDIOUS SITUATION BETWEEN ALL THE ELEMENTS IN PLAY
THIS SUNDAY MORNING.
HEADING INTO THE DAY...THE MOISTURE INFLUX CONTINUES WITH RAIN
ANTICIPATED ALL DAY AND FOR ONCE...WINDS SHIFT TO THE SOUTHWEST AT
THE SURFACE LATER TODAY ALLOWING WARMER TEMPS INTO THE AREA AS
HIGHS TODAY WARM INTO THE UPPER 40S. HEADING INTO TONIGHT...THE
COLD FRONT PUSHES SOUTHEAST SAGS SOUTH OF THE TN BORDER AND
COLDER AIR FILTERS IN BEHIND TONIGHT. AS THE DEPTH OF THE
MOISTURE BEHIND THE FRONT BECOMES SHALLOW...CAA WILL CHANGE
PRECIP TO ALL SNOW. THERE MAY BE A SHORT PERIOD OF RAIN MIXED IN
BEFORE THE COMPLETE CHANGE OVER. BECAUSE OF THE LOSS OF
MOISTURE...MOST LOCATIONS WILL ONLY SEE A DUSTING. EXIT OF THIS
FEATURE WILL OCCUR SHORTLY AFTER DAWN ON MONDAY WITH A NICE
REBOUND FOR HIGHS ON MONDAY CLIMBING INTO THE 40S.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM EST SUN MAR 1 2015
MID AND UPPER LEVEL PATTERN REMAINS ZONAL THROUGH THE SHORT TERM
WITH LITTLE SENSIBLE WEATHER TO SPEAK OF OTHER THAN THE APPROACH
OF A STORM SYSTEM OVER THE WEEKEND. MAIN CONCERN WILL BE THE COLD
AIR IN PLACE ACROSS THE AREA AT THE ONSET OF ANY PRECIPITATION
LATE SATURDAY NIGHT...EARLY SUNDAY MORNING.
NAM ADVERTISES A 40-50 KT H925-H850 LLJ DEVELOPING LATE SATURDAY
NIGHT INTO SUNDAY MORNING...WHICH BRINGS IN A WARM NOSE OF AT LEAST
+5C. TYPICALLY THE NAM HANDLES THE WARM NOSE BETTER THAN THE GFS SO
EXPECT ANY PRECIPITATION THAT MAY DEVELOP DURING THAT TIME FRAME TO
MELT ALOFT. THE REST DEPENDS ON BOUNDARY LAYER AND SFC TEMPS. WITH A
DECENT SNOW PACK STILL IN PLACE...ONLY A BRIEF FEW HOURS OF TEMPS
ABOVE FREEZING SATURDAY AFTERNOON...AND A 5-6 INCH FROST DEPTH
EXPECT MUCH OF THE AREA WOULD BE AT RISK FOR A WINTRY MIX AT THE
ONSET OF PRECIPITATION.
OTHERWISE WE ARE LOOKING AT ANOTHER VERY COLD NIGHT TONIGHT AS
TEMPERATURES DROP INTO THE SINGLE DIGITS FOR A GOOD PORTION OF THE
AREA...MID TEENS FOR THE REST. CONSEQUENTLY...ANY MELTING OF SFC
SNOWFALL AND ICE WILL REFREEZE OVERNIGHT. SOME AREA ROAD WILL LIKELY
CONTINUE TO SEE SOME ISOLD SLICK SPOTS. TEMPERATURES WILL MAKE A
EFFORT TO REBOUND TOMORROW BUT INCOMING CLOUD COVER MAY DAMPEN THE
WARM UP CONSIDERABLY. FOR NOW WENT MORE OPTIMISTIC AND TOOK
AFTERNOON HIGHS INTO THE MID AND UPPER 30S...NEAR 40 FOR MOST
LOCATIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 104 PM EST SUN MAR 1 2015
LIGHT RAIN SHOWERS CONTINUE ACROSS CENTRAL AND NORTHEAST KY AT
THIS TIME...WITH ALMOST EVERY TAF SITE BEING IMPACTED. SO
FAR THE RAIN REMAINS FAIRLY LIGHT...WITH ONLY MVFR RESTRICTIONS
TO VIS. THE HEAVIEST RAIN WILL CONTINUE TO BE ACROSS THE NORTHERN
FORECAST AREA...WITH KSYM POSSIBLY SEEING SOME TEMPORARILY DROPS
DOWN TO IFR VIS CONDITIONS IN SOME OF THE HEAVIER BURSTS.
OVERALL...MOST OF CENTRAL AND EASTERN KY CONTINUES TO SEE MVFR
SKIES...AND EXPECT THIS TO CONTINUE THROUGH AT LEAST THIS EVENING.
WOULDN/T BE SURPRISED IF WE DROPPED TO IFR LATER ON TONIGHT AS WE
SEE SOME OF OUR BEST SATURATION. THERE IS STILL THE POTENTIAL THAT
SOME SNOW COULD MIX IN WITH THE RAIN ON THE BACK SIDE OF THIS
SYSTEM...JUST BEFORE TAPERING OFF SOON AFTER. TRIED TO TIME THIS
OUT IN THE FORECAST...WITH MOST OF THE SNOW EXPECTED TO BE AFTER
AROUND 6-7Z. PRECIP WILL BE ENDING SOMETIME TOMORROW
MORNING...WITH SKIES SLOWLY BREAKING UP DURING THE DAY. WINDS WILL
SHIFT BACK TO A MORE NW TO NRLY DIRECTION...BUT SHOULD GENERALLY
REMAIN BELOW 10KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SHALLENBERGER
LONG TERM...AR
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS CARIBOU ME
337 PM EST SUN MAR 1 2015
.SYNOPSIS...
LOW PRESSURE WILL APPROACH THE REGION FROM OHIO VALLEY THIS
EVENING AND MOVING THROUGH THE REGION LATER TONIGHT INTO MONDAY.
THIS SYSTEM WILL BRING SOME SNOW TO THE FORECAST AREA. HIGH
PRESSURE WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM
THE WEST. ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
THINGS TO FOCUS ON THIS TERM WILL BE SNOWFALL AMOUNTS AND SNOW
SQUALL POTENTIAL ON MONDAY.
18Z SURFACE ANALYSIS SHOWED HIGH PRES S OF THE REGION RIDGING
ACROSS THE STATE OF MAINE. MID AND HIGH CLOUDS MOVING NE PER THE
LATEST SATELLITE IMAGERY WILL CAP ANY FURTHER PROGRESSION OF
TEMPERATURES THIS AFTERNOON. READINGS ACROSS NORTHERN AND WESTERN
AREAS HIT THE MID/UPPER 20S WHILE CENTRAL AND DOWNEAST CLOSED IN
AROUND 30. TEMPERATURES WILL FALL BACK AFTER SUNSET BUT W/THE
CLOUDS MOVING IN, ANY FURTHER DROP WILL BE SLOW OR EVEN READINGS
LEVELING OFF ESPECIALLY DOWNEAST AND THE COAST. NORTHERN AREAS
COULD SEE TEMPERATURES FALL OFF QUICKER AS INITIAL CLOUD SHIELD IS
THIN PER THE OBS. SNOW IS FORECAST TO BREAK OUT ACROSS THE
SOUTHERN AND DOWNEAST AREAS THIS EVENING. THE LATEST RUNS OF THE
RAP AND HRRR 3KM DOING WELL PER THE RADAR TRENDS AND METARS. THIS
SET OF GUIDANCE SHOWS SNOW SETTING UP LATER THAN PREVIOUSLY
EXPECTED. THEREFORE, PULLED BACK ON THE TIMING BY A FEW HRS. LOW
PRES MOVING E FROM THE OHIO VALLEY IS SHOWN BY THE MODEL GUIDANCE
TO RE-DEVELOP OFF THE MAINE COAST LATER TONIGHT W/AN INVERTED TROF
SETTING UP FOR A TIME ACROSS EASTERN SECTIONS. SOME FORCING IS
THERE AND W/TEH LLVL CONVERGENCE, THERE COULD BE A BRIEF PERIOD OF
MODERATE SNOW WHERE RATIOS OF 15-20:1 COULD BE REALIZED W/2-4 INCHES
OF SNOW FROM 06-12Z. THE HIGHEST SNOWFALL WILL BE ACROSS THE COAST
AND GIVEN THE 3-4 INCH AMOUNTS SHOWN, DECIDED TO ISSUE A WINTER
WEATHER ADVISORY FOR SNOW. THIS WAS COORDINATED W/GYX. FURTHER N
AND W, SNOWFALL AMOUNTS WILL DROP OFF AS DYNAMICS WILL BE WEAKER
W/A GENERAL 1-3 INCHES AT BEST.
FOR MONDAY, SNOWFALL WILL COME TO AN END QUICKLY ACROSS THE W AND
DOWNEAST REGION WHILE EASTERN AREAS INCLUDING EASTERN SECTION OF
AROOSTOOK COUNTY WILL HANG ON TO A PERIOD OF SNOW THROUGH 10 AM
OR SO. THINGS WILL TRANSITION TO A MORE SHOWERY NATURE FOR THE
SNOW W/A GOOD CHANCE FOR SOME SNOW SQUALLS. THE NAM AND GFS
SOUNDINGS POINT TO STEEPENING LAPSE RATES(6/5-7.0C/KM) AT
850-700MBS AND FORECAST CAPE OF 70+ JOULES. THIS WILL BE IN
ASSOCIATION W/AN ARCTIC FRONT THAT IS FORECAST TO SLIDE ACROSS THE
REGION MONDAY AFTERNOON. THE BTV SNOW SQUALL PARAMETER SHOWED 2
AREAS OF SQUALL POTENTIAL W/ONE ACROSS NORTHERN AND WESTERN AREAS
AND THE SECOND AREA ACROSS EASTERN MAINE. TEMPERATURES WILL DROP
OFF SHARPLY BEHIND THIS BOUNDARY AFTER 19Z(2 PM). A QUICK INCH OF
SNOW CAN BE EXPECTED W/THE SQUALLS ALONG W/WIND GUSTS UP TO 30
MPH. THIS SITUATION IS SIMILAR TO THE SQUALL EVENT THAT OCCURRED A
WEEK AGO(2/23)WHERE MOIST OFF THE OPEN ST. LAWRENCE COMBINED W/THE
FRONT AIDING IN SOME HEFTY SNOW SQUALLS/SNOW SHOWERS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN FORECAST CONCERN FOR THE SHORT TERM IS A QUICK MOVING
SHORTWAVE WHICH WILL AFFECT MOST OF NEW ENGLAND TUESDAY NIGHT INTO
WEDNESDAY. THE COMBINATION OF DPVA AND WAA WILL PROVIDE SUFFICIENT
LIFT TO PRODUCE LIGHT TO MODERATE SNOW ACROSS OUR CWA DURING THIS
TIME FRAME...WITH CONDITIONS EXPECTED TO DRY OUT QUICKLY WEDNESDAY
AFTERNOON. HAVE FOLLOWED CLOSELY TO CONSALL QPF WHICH RESULTS IN
A GENERAL 3 TO 5 INCHES OF SNOWFALL. THE HIGHEST AMOUNTS WILL
OCCUR DOWNEAST...BUT WITH TEMPS IN THE LOWER 40S WEDNESDAY
AFTERNOON...MUCH OF THE SNOW WILL COMPACT OR MELT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE UPPER LEVEL FLOW WILL BECOME ZONAL AND PROGRESSIVE DURING THE
EXTENDED FORECAST PERIOD...BRINGING A SERIES OF VERY WEAK
SHORTWAVES ACROSS THE NORTHEAST. THIS WILL RESULT IN SEASONABLY
COLD CONDITIONS WITH OCCASIONAL SNOW SHOWERS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: VFR DROPPING TO MVFR LATER THIS EVENING AND THEN IFR
OVERNIGHT FOR ALL TERMINALS. CONDITIONS ARE FORECAST TO IMPROVE TO
VFR FOR KBGR AND KBHB MIDDAY MONDAY W/THE NORTHERN TERMINALS
GOING FROM IFR TO MVFR.
SHORT TERM: MVFR TO IFR CONDITIONS SHOULD PREVAIL ACROSS THE CWA
TUESDAY NIGHT INTO WEDNESDAY MORNING IN ASSOCIATION WITH THE
AFOREMENTIONED SNOWFALL. CONDITIONS WILL IMPROVE WEDNESDAY
AFTERNOON.
&&
.MARINE...
NEAR TERM: PER COORDINATION W/GYX, DECIDED TO GO W/A GALE WARNING
FOR MONDAY AFTERNOON INTO THE EVENING DUE TO THE ARCTIC FRONT
MOVING ACROSS THE WATERS. NW WINDS W/CAA WILL ALLOW FOR WINDS TO
HIT 25 TO 30 W/GUSTS UP TO 35 KTS. BUFKIT PROFILES SHOW GUST
POTENTIAL TO 40 KTS OVER THE OUTER WATERS. MIDNIGHT CREW HAD THIS
HANDLED WELL AND STAYED CLOSE TO IT.
SHORT TERM: A SMALL CRAFT ADVISORY WILL LIKELY BE NEED FOR OUR
COASTAL MARINE ZONES TUESDAY NIGHT INTO WEDNESDAY AS STORM SYSTEMS
CROSSES THE AREA...CREATING BREEZY SOUTHWEST WINDS AND HIGH WAVES.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST
MONDAY FOR MEZ029-030.
MARINE...GALE WARNING FROM 3 PM MONDAY TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...BERDES
LONG TERM...BERDES
AVIATION...HEWITT/BERDES
MARINE...HEWITT/BERDES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
127 PM EST SUN MAR 1 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON. LOW
PRESSURE WILL CROSS THE REGION TONIGHT INTO MONDAY. HIGH PRESSURE
WILL BUILD TOWARD THE AREA MONDAY NIGHT AND TUESDAY FROM THE WEST.
ANOTHER LOW WILL CROSS THE REGION WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
115 PM UPDATE...FIRST BATCH OF CLOUDS PULLING EASTWARD PER THE
LATEST SATELLITE LOOP W/SOME PARTIAL CLEARING. THIS WILL ALLOW FOR
SOME WARMING INTO LATE AFTERNOON. ANOTHER AREA OF CLOUDS
ASSOCIATED W/THE STORM SYSTEM MOVING INTO THE OHIO VALLEY SET TO
ADVANCE INTO THE REGION. THEREFORE ADJUSTED MAX TEMPS UP A FEW
DEGREES W/SOME NORTHERN AREAS HITTING THE UPPER 20S AND DOWNEAST
TOPPING 30F.
REGIONAL RADAR LOOP SNOW SOME PRECIP(LIGHT) MOVING ACROSS SOUTHERN
NEW ENGLAND TOWARD SOUTHERN MAINE. THE MORE SIGNIFICANT PRECIP
WAS MOVING ACROSS LONG ISLAND. THE RAP AND HRRR 3KM MODELS WERE
DOING WELL W/THIS SETUP W/DRY CONDITIONS INTO EARLY EVENING. SNOW
EXPECTED TO DEVELOP LATER IN THE EVENING ACROSS THE SW AND
DOWNEAST AND SPREAD NE OVERNIGHT INTO MONDAY. MORE ON THIS LATER.
A LOW PRESSURE SYSTEM WILL DEEPEN SIGNIFICANTLY AS IT CROSSES THE
GULF OF MAINE OVERNIGHT ENROUTE TO HALIFAX. THE FORECAST AREA WILL
RECEIVE A GLANCING BLOW FROM THE STORM WITH THE BEST QPF ALONG THE
WASHINGTON COUNTY COAST WHERE THREE- TENTHS OF AN INCH IS
EXPECTED. WITH SNOW-WATER RATIOS GENERALLY AROUND 15 TO 1 OR
HIGHER...THIS TRANSLATES TO A NARROW SWATH OF 4-6 INCHES POSSIBLE
FOR HARD-HIT MACHIAS AND EASTPORT AS WELL AS MDI. AMOUNTS WILL
TAPER TO THE NORTH SUCH JUST AN INCH IS FORECAST FOR FORT KENT AND
MADAWASKA. WITH ADVISORY CRITERIA AT 4 INCHES...WILL HOLD OFF ON
ANY WINTER WEATHER HEADLINES UNTIL LATER TODAY.
&&
.SHORT TERM /MONDAY/...
LOW PRESSURE IN THE GULF OF MAINE MONDAY MORNING WILL MOVE AWAY TO
THE NORTHEAST. STRONG HIGH PRESSURE WILL THEN BUILD IN FROM THE
WEST MONDAY NIGHT AND CREST OVER THE STATE TUESDAY. EXPECT SNOW TO
END LATE MONDAY AS LOW PRESSURE MOVES AWAY. WILL USE A MODEL
CONSENSUS APPROACH AND BLEND THE NAM... GFS AND ECMWF FOR POP...
SKY AND QPF. HAVE USE THE OFFICE SNOW FROM THICKNESS TOOL FOR SNOW
ACCUMULATIONS. WILL USE THE NAM12 FOR WINDS. FOR TEMPERATURE AND
DEW POINT HAVE USED THE SUPER BLEND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL MOVE TO THE EAST TUESDAY NIGHT AS LOW PRESSURE
APPROACHES FROM THE WEST. THIS SYSTEM IS EXPECTED TO PASS TO THE
NORTHWEST OF THE STATE WEDNESDAY MORNING. THE TRACK OF THE LOW
WILL RESULT IN SNOW CHANGING TO RAIN ACROSS SOUTHERN AND CENTRAL
AREAS AS WARM AIR ADVECTION TAKES PLACE AHEAD OF THE LOW. COLD AIR
WILL RETURN AS THE LOW PASSES TO THE NORTH LATE WEDNESDAY AND
WEDNESDAY NIGHT. HIGH PRESSURE WILL THEN BUILD IN FROM THE WEST
THURSDAY. WILL USE THE SUPER BLEND TO POPULATE GRIDS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
NEAR TERM: VFR TODAY AND INTO EARLY SUNDAY EVENING. IFR TONIGHT
IN SNOW FOR ALL SITES. LIFR POSSIBLE FOR SEVERAL HOURS AT
BGR AND BHB.
SHORT TERM:
EXPECT IFR/MVFR CONDITIONS TO TRANSITION TO VFR MONDAY. VFR
CONDITIONS EXPECTED MONDAY NIGHT AND TUESDAY. IFR CONDITIONS
EXPECTED TUESDAY NIGHT AND WEDNESDAY. EXPECT VFR CONDITIONS
THURSDAY.
&&
.MARINE...
NEAR TERM: WINDS WILL INCREASE TO SCA LEVELS THIS EVENING IN THE
OUTER WATERS THEN DECREASE AGAIN AFTER MIDNIGHT. WITH THE GALE
WATCH OUT...HAVE ELECTED NOT TO CREATE A SECOND HEADLINE.
SHORT TERM: FOR SUSTAINED WINDS WILL USE THE NAM12. FOR WAVES:
EXPECT OFF-SHORE WIND WAVE TO DOMINATE MONDAY WITH WAVE HEIGHTS
DEPENDENT ON FETCH DISTANCE OFF-SHORE. SOUTHERLY WIND WAVE WILL
BUILD TUESDAY NIGHT INTO WEDNESDAY AS LOW PRESSURE PASS TO THE
NORTHWEST OF THE REGION. WILL USE THE NEAR SHORE WAVE MODEL FOR
WAVE GRIDS THROUGH TUESDAY THEN TRANSITION TO THE WW III.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
423 PM EST SUN MAR 1 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 422 PM EST SUN MAR 1 2015
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A TROF EXTENDING FROM
HUDSON BAY INTO THE NRN PLAINS. WITHIN TROF...NEXT SHORTWAVE OF
INTEREST IS NOW OVER THE DAKOTAS/MN. CLOSER TO HOME...SOME
-SHSH/FLURRIES HAVE SPREAD FROM WRN UPPER MI INTO PORTIONS OF CNTRL
UPPER MI TODAY IN VCNTY OF SFC TROF WHICH IS NOW ROUGHLY BISECTING
UPPER MI.
TONIGHT...SHORTWAVE NOW OVER THE DAKOTAS WILL SWING ACROSS THE WRN
GREAT LAKES THIS EVENING. AREA OF DEEP LAYER FORCING PER QVECTORS
SHIFTS ACROSS UPPER MI LATE THIS AFTN AND EVENING. WITH ASSOCIATED
BRIEF PERIOD OF DEEP MOISTURE...850MB TEMPS AROUND -18C...AND A
ROUGHLY 3KFT DGZ LAYER BTWN ROUGHLY 2K AND 5KFT...WOULD NORMALLY BE
CONCERNED ABOUT SEEING SEVERAL HRS OF HEALTHY LAKE ENHANCED SNOW IF
THE LAKE WASN`T MOSTLY ICE COVERED. THAT SAID...THE BRISK SW TO W
WINDS OF THE LAST COUPLE OF DAYS HAVE OPENED UP SOME NOTABLE GAPS IN
THE ICE...SO THERE WILL BE AN OPPORTUNITY FOR LOCALIZED MORE
PERSISTENT LES AND SOME SNOW ACCUMULATION. FROM TODAYS MODIS AND VIS
SATELLITE IMAGERY...A COUPLE OF IMPORTANT GAPS IN THE ICE ARE NOTED
FROM AROUND THE HURON ISLANDS DOWN PAST GRANITE ISLAND AND OVER TO N
OF MUNISING...AND ALSO IN THE AREA E OF THE APOSTLE ISLANDS WHICH
HAS CERTAINLY HAD A TENDENCY TO OPEN UP OVER THE LAST FEW WEEKS WHEN
WINDS ARE SW. WILL THUS HIT HIGHEST POPS AND 1-2 INCHES OF SNOW
DOWNWIND OF THESE OPEN WATER AREAS THIS EVENING (JUST N OF IRONWOOD
TO THE PORCUPINE MTNS AND ALSO ALGER COUNTY). STRONG NEGATIVE
DYNAMICS TAKE OVER DURING THE OVERNIGHT...SO LES INTENSITY WILL
DIMINISH RATHER QUICKLY AFTER MIDNIGHT. AWAY FROM THESE AREAS...
WNW/NW FLOW LES SHOULD BE NO MORE THAN SCT WITH ACCUMULATIONS UNDER
1 INCH. ELSEWHERE...EXPECT SOME FLURRIES IN MOST AREAS AS SHORTWAVE
PASSES. TEMPS IN THE INTERIOR W TOWARD THE WI BORDER SHOULD FALL
DOWN TOWARD ZERO WITH CLEARING SKIES OVERNIGHT. OTHERWISE...MIN
TEMPS SHOULD BE WITHIN A FEW DEGREES OF 10F.
ANY LINGERING LES TO THE E OF MARQUETTE WILL END BY MON AFTN UNDER
WAA/BACKING WINDS WITH PASSAGE OF SFC HIGH PRES RIDGE (BY MID AFTN
850MB TEMPS ARE FCST TO BE AROUND -12C). WHILE THERE MAY BE SOME
STRATOCU DEVELOPMENT EVEN WHERE SKIES ARE CLEAR TO START THE
DAY...EXPECT ALL AREAS TO BECOME SUNNY DURING THE DAY WITH DRY AIR
MASS AND DEPARTURE OF 850MB THERMAL TROF. HIGH TEMPS WILL RANGE FROM
AROUND 20 TO THE UPPER 20S...COOLEST OVER THE FAR E...CLOSER TO
DEPARTING THERMAL TROF.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN MAR 1 2015
...WIDESPREAD SNOW TUESDAY MAY EVENTUALLY NEED A HEADLINE...
PRIMARY HIGHER IMPACT WEATHER THROUGH THE NEXT WEEK IS LIMITED TO
WIDESPREAD SNOW EXPECTED TO AFFECT THE AREA ON TUESDAY AND TUESDAY
EVENING. OTHERWISE...WARM UP EARLY IN THE WEEK WILL BE REPLACED BY A
COOL DOWN WEDNESDAY INTO THURSDAY IN WAKE OF THE TUESDAY SYSTEM. MAY
BE SOME LAKE EFFECT WEDNESDAY AND WEDNESDAY NIGHT BUT CHANCES WILL
BE HELD DOWN AS LAKE SUPERIOR REMAINS MOSTLY ICE COVERED. TEMPS
REBOUND AGAIN BY NEXT FRIDAY AND COULD STAY AT SIMILAR LEVELS INTO
NEXT WEEKEND.
HIGH PRESSURE EXITS EAST ON MONDAY EVENING WITH CLOUDS INCREASING
THROUGH THE NIGHT AHEAD OF A TWO-PIECED LOW PRESSURE SYSTEM HEADING
TOWARD REGION. NORTHERN STREAM WAVE AND ITS ASSOCIATED LOW SLIDES FM
NORTHERN MANITOBA TO NORTHERN ONTARIO BY DAYBREAK ON TUESDAY.
MEANWHILE THE SOUTHERN STREAM WAVE WILL PUSH OVER THE CENTRAL PLAINS
AS THE SFC LOW ARRIVES ALONG THE NEB/IOWA BORDER. MOISTURE ADVECTION
AHEAD OF THE LOW-MID LEVEL TROUGH MAXIMIZES OVERNIGHT BTWN H85 AND
H5. LIFT IS PRETTY STRONG WITHIN THE MOIST ADVECTION...SO SHOULD SEE
LGT SNOW BEGIN TO DEVELOP AFTER MIDNIGHT TOWARD WI BORDER WITH
LOWEST 100MB GRADUALLY SATURATING. HINTS ARE THERE THAT THE INITIAL
SNOW COULD BE DRIVEN BY FGEN...BUT WHERE MAX RIBBON OF HEAVIER SNOW
SETS UP IS NOT CERTAIN. 12Z NAM SHOWS IT MORE OVER WESTERN CWA...BUT
THIS IS AT ODDS WITH NAM DOMINATED SREF OUTPUT AND SEEMS TOO FAR
NORTH AS IT IS ALSO FARTHER NORTH WITH SOUTHERN STREAM SFC LOW ON
INTO TUESDAY. WILL KEEP WITH IDEA OF HEAVIER QPF/SNOW ON TUESDAY ON
EDGE OF GREATER H85-H7 MOISTURE TRANSPORT WHICH MAINLY IS MAXIMIZED
JUST TO THE SOUTH AND SOUTHEAST OF UPR MICHIGAN OUT AHEAD OF
SOUTHERN STREAM SFC LOW CROSSING LOWER MICHIGAN. H7 MIXING RATIOS
GFS/ECMWF STAY BLO 3G/KG THROUGHOUT TUESDAY. MIXING RATIOS INTO THE
SYSTEM AND BLEND OF QPF FM GFS/ECMWF ALONG WITH SLR/S CENTERED ON
15:1...SUGGEST ADVY LEVEL SNOWFALL SCNTRL CWA INTO THE EASTERN CWA.
WILL CONTINUE TO MENTION IN HWO/EHWO GRAPHICS.
PHASING BTWN THE NORTHERN STREAM WAVE AND SOUTHERN STREAM WAVES
NEVEN REALLY TAKES OFF SO THIS SYSTEM SHOULD STAY PROGRESSIVE ON
TUESDAY NIGHT AS MAIN CORE OF UPPER JET ENERGY STAYS OUT AHEAD OF
THE TROUGH. CHANCE POPS LINGER EARLY TUESDAY EVENING IN THE
EAST...BUT OTHERWISE POPS WITH THE SYSTEM WILL BE OUT OF THE AREA.
INITIALLY LAKE EFFECT IN WAKE OF THE SYNOPTIC SNOW ON TUESDAY
EVENING PROBABLY STAYS ON THE LIGHT SIDE DUE TO MARGINALLY COLD AIR
/H85 TEMPS WARMER THAN -15C/ AND MAINLY ICE COVERED LAKE SUPERIOR.
GFS SOUNDINGS SHOW INCREASE OF MOISTURE H8-H7 LATE TUESDAY NIGHT
INTO WEDNESDAY WHILE COLD AIR ADVECTION WITH H85 TEMPS FALLING BLO
-20C OVER LK SUPERIOR RESULTS IN INVERSIONS RISING UP TO A MAX OF
8KFT WEDNESDAY MORNING OVER EASTERN LK SUPERIOR. DESPITE THE HIGH
ICE COVERAGE...SCT POPS FOR LAKE EFFECT SNOW SHOWERS AND ALSO
FARTHER DOWNSTREAM OVER LAND AREAS WITH SOME HELP FM DAYTIME HEATING
AS THE HYBRID LAKE EFFECT SEASON IS UNDERWAY DUE TO HIGHER SUN
ANGLE. WITH NW WINDS UP TO 30 MPH ALONG THE LK SUPERIOR
SHORELINES...PROBABLY WILL HAVE BLSN/POOR VSBY IN THE SNOW BELTS
NEAR LK SUPERIOR EAST OF MQT. EVEN MINUS BLSN...LES WILL BE GOOD AT
REDUCING VSBY AS THE SNOWFLAKES WILL BE BECOMING SMALLER. H85 TEMPS
CONTINUE TO FALL BLO -25C BY LATE IN THE DAY ON WEDNESDAY...SO TEMPS
WILL BE STEADY OR SLOWLY FALL THROUGH THE DAY.
ARRIVAL OF HIGH PRESSURE RIDGE AND WINDS BACKING W-WSW BY THURSDAY
MORNING WILL DIMINISH ANY SNOW SHOWERS AS WINDS BECOME MORE
OFFSHORE. TEMPS OVER MUCH OF THE INTERIOR ON WEDNESDAY NIGHT COULD
TANK WELL UNDER 10 BLO ZERO. MAY SEE MARGINALLY LOW WIND CHILLS ON
THURSDAY MORNING...BUT FARTHER INLAND WHERE TEMPS WILL BE COLDEST
EXPECT THE WINDS TO BE NEARLY CALM. STILL COLD ON THURSDAY AS CORE
OF COLDER TEMPS ALOFT SLOWLY HEADS ACROSS EASTERN CANADA.
WARM FRONT MOVES TOWARD UPPER LAKES THURSDAY NIGHT INTO FRIDAY
MORNING. WARMING FIRST OCCURS ALOFT THEN MAKES ITS WAY TO SFC BY
FRIDAY AFTN. GFS SOUNDINGS SHOW MID LEVEL MOISTURE QUICKLY SWEEPS
ACROSS LEAVING SCT-BKN LOW CLOUDS LATER ON FRIDAY. MOISTURE AND LIFT
DOES NOT SYNC UP...SO NOT EXPECING MUCH IN WAY OF LGT SNOW. BETTER
LINKING OF LOW AND MID LEVEL MOISTURE IS OVER NORTHERN LK SUPERIOR
AND NORTHERN ONTARIO. DECENT AGREEMENT IN THIS IDEA FM GFS AND
ECMWF. COLD AIR NOT AS EMPHATIC FOR NEXT WEEKEND WITH GFS AND ECMWF
SHOWING H85 TEMPS MAINLY WARMER THAN -12C. GIVEN THE RUN-TO-RUN
DIFFERENCES IN MODELS AND DIFFERENCES IN MODEL SOLUTIONS...WILL JUST
RUN WITH CONSENSUS FRIDAY THROUGH SUNDAY. RESULT IS DAYTIME TEMPS IN
THE 20S TO NEAR 30 DEGREES AND ONLY SMALL CHANCES OF LGT SNOW MAINLY
OVER THE NORTH AND EAST CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 310 PM EST SUN MAR 1 2015
SEEMS THAT POTENTIAL FOR GALES IS INCREASING TUESDAY NIGHT INTO
WEDNESDAY IN WAKE OF COLD FRONT THAT MOVES THROUGH ON TUESDAY.
STRONGEST WINDS WOULD BE OVER THE EASTERN HALF OF LK SUPERIOR.
OTHERWISE...EXPECT WINDS THROUGH THE WEEK TO BE 15 TO 25 KTS.
LATEST OFFICIAL ICE CONCENTRATION ON LK SUPERIOR IS AROUND 95 PCT.
EVEN WITH STRONG WINDS AT TIMES THIS WEEK...EXPECT THE HIGHER ICE
COVERAGE TO PERSIST AS TEMPERATURES STAY BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1245 PM EST SUN MAR 1 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 406 AM EST SUN MAR 1 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW UPR TROF EXTENDING
FM HUDSON BAY INTO THE NRN PLAINS. TWO SHRTWVS OF NOTE ARE EMBEDDED
IN THIS TROF THAT WL BE OF CONCERN FOR THE FCST. THE FIRST IS MOVING
ALONG THE MN/ONTARIO BORDER EARLY THIS MRNG. ALTHOUGH THE COLDER CLD
TOPS ARE CONFINED TO ONTARIO...SOME LOCATIONS IN MN WITHIN THE
RELATIVELY POORLY DEFINED COMMA TAIL ARE PICKING UP SOME LIGHT
SN/FLURRIES. THE MAIN LIMITING FACTOR FOR MORE PCPN/ENHANCED CLDS IS
ONLY MODEST ISENTROPIC ASCENT BEST SHOWN ON THE 280K SFC/DEEP LYR
QVECTOR CNVGC AND ABSENCE OF DEEP MSTR PER THE 00Z INL/MPX RAOBS.
MID CLDS IN ADVANCE OF THE SHRTWV HAVE INVADED THE CWA...LIMITING
THE DIURNAL FALL OF TEMP IN THE STEADY SW FLOW AHEAD OF THE
ASSOCIATED SFC LO PRES TROF MOVING THRU MN. SOME LIGHT SN HAS ALSO
DVLPD OVER THE ERN CWA WITH SSW FLOW OFF LK MI. LOOKING FARTHER
UPSTREAM...A SECOND SHRTWV IS DIGGING SEWD FM SASKATCHEWAN INTO THE
NRN PLAINS. THERE IS AN AREA OF CLD COVER ASSOCIATED WITH THIS
FEATURE...AND A FEW LOCATIONS ARE REPORTING SOME LIGHT SN.
MAIN FCST CONCERNS THRU TNGT WL FOCUS ON POPS ASSOCIATED WITH THE
TWO SHRTWVS AS WELL AS LES POTENTIAL TNGT IN THE CAA FOLLOWING THESE
DISTURBANCES.
TODAY...FIRST SHRTWV IS FCST TO CONTINUE EWD ACROSS NRN LK SUP THIS
MRNG. MAINTAINED SOME LO CHC POPS THIS MRNG OVER MAINLY THE W AND N
PORTION OF THE CWA CLOSER TO THE SHRTWV TRACK AND AREA OF COLDER CLD
TOPS/HIER H85-5 RH. THERE WL BE ANOTHER CHC OF SOME SN THIS AFTN
OVER MAINLY THE E HALF OF THE CWA WHEN THE ARRIVAL OF SOME SHARPER
PVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE TRAILING SHRTWV WL
ARRIVE COINCIDENTALLY WITH THE SFC TROF. ALTHOUGH WRN LK SUP REMAINS
MOSTLY ICE COVERED...ARRIVAL OF SOME DEEPER MSTR ACCOMPANYING THE
SECOND SHRTWV AND COLDER AIR /H85 TEMPS FALLING NEAR -16C BY 00Z
MON/ IN THE WNW H925 FLOW BEHIND THE TROF WL BRING ABOUT A CHC FOR
SOME SN SHOWERS LATER IN THE DAY OVER THE W AS WELL. WITH A SW
VEERING W FLOW DVLPG THIS AFTN...EXPECT THE HIEST MAX TEMPS IN THE
25 TO 30 RANGE OVER THE DOWNSLOPE AREA OF THE CENTRAL...WHERE THERE
WL BE MORE IN THE WAY OF SOME BREAKS OF SUNSHINE AS WELL.
TNGT...NW FLOW OF COLDER AIR...WITH TEMPS WITHIN TRAILING H85
THERMAL TROF FCST AS LO AS -18C...FOLLOWING THE EXITING SFC TROF WL
RESULT IN SOME LK EFFECT SN SHOWERS MAINLY IN THE NW WIND SN BELTS
DESPITE THE OVERALL ICE COVER. THE BEST CHC FOR THESE SN SHOWERS WL
BE E OF MARQUETTE WITH A LONGER FETCH LENGTH OVER THE MAINLY ICE
COVERED LK. ARRIVAL OF MORE ACYC FLOW IN ADVANCE OF SFC HI PRES RDG
MOVING INTO MN AND SHARPLY LOWERING INVRN AOB 3K FT AGL ASSOCIATED
WITH STRONG SUBSIDENCE ACCOMPANYING VIGOROUS DNVA/06Z-12Z H5 HGT
RISES UP TO 100M AHEAD OF APRCHG SHRTWV RDG AXIS SHOULD END THE LES
OVER THE W LATE. LLVL DRYING/CLRG WL ALLOW TEMPS TO DIP AT LEAST
CLOSE TO ZERO OVER THE INTERIOR W CLOSER TO THE INCOMING SFC HI
PRES...WHICH SHOULD CAUSE THE STEADY WINDS TO DIMINISH A BIT LATE IN
THAT AREA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 416 AM EST SUN MAR 1 2015
MAIN ISSUE THIS FORECAST PERIOD WILL BE WIDESPREAD LIGHT TO MODERATE
SNOWFALL POTENTIAL TUESDAY INTO TUESDAY EVENING...ESPECIALLY OVER
THE EAST HALF OF THE UPPER PENINSULA. A BIT WARMER TEMPERATURES WILL
LINGER THROUGH EARLY IN THE WORK WEEK BEFORE ANOTHER QUICK SHOT OF
VERY COLD AIR WORKS INTO THE AREA WEDNESDAY AND THURSDAY.
MONDAY...A WEAK FRONT/SURFACE TROUGH ALONG WITH AN UPPER LEVEL 500MB
TROUGH AXIS WILL CONTINUE TO SHIFT TO THE EAST OF THE U.P. DURING
THE DAY MONDAY. AS THIS HAPPENS A BROAD HIGH PRESSURE
SYSTEM...CENTERED OVER MISSOURI...WILL SHIFT INTO THE LOWER GREAT
LAKES. THIS WILL KEEP A RIDGE ACROSS MUCH OF THE UPPER GREAT LAKES
REGION WITH MODERATING UPPER LEVEL TEMPERATURES ACROSS THE REGION.
ADDITIONALLY...MUCH DRIER AIR WILL PUSH INTO THE AREA AS WINDS
BECOME WEST SOUTHWESTERLY THROUGH THE DAY. THIS WILL ALLOW MOST
AREAS TO SEE MAINLY SUNNY SKIES WITH HIGHS IN THE 20S. THIS IS STILL
AROUND 5 TO 10 DEGREES BELOW NORMAL...BUT IT WILL DEFINITELY BE
WARMER THAN THE LAST SEVERAL WEEKS.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE SURFACE HIGH PRESSURE
SYSTEM WILL SHIFT TO THE LOWER GREAT LAKES THROUGH MONDAY
EVENING...THEN TO THE EASTERN SEABOARD LATE MONDAY NIGHT. THIS WILL
ALLOW A MORE MOIST...SLIGHTLY WARMER...SOUTHERLY FLOW TO DEVELOP ON
THE BACK SIDE OF THE HIGH. AT THE SAME TIME...A SURFACE LOW PRESSURE
SYSTEM IS PROGGED TO DEVELOP OVER THE FOUR CORNERS REGION OF THE
CONUS. ANOTHER...STRONGER WAVE OF ENERGY IS PROGGED TO PUSH ACROSS
CENTRAL CANADA AND WORK TOWARD THE JAMES BAY AREA. BETWEEN THE TWO
SYSTEMS...IT LOOKS LIKE MOST OF THE U.P. WILL SEE WIDESPREAD
SNOWFALL VERY LATE MONDAY NIGHT THROUGH TUESDAY EVENING...WITH THE
HEAVIER SNOWFALL TOTALS EXPECTED ACROSS THE EAST HALF OF THE U.P. AT
THE ONSET LATE MONDAY NIGHT...MODELS ARE DEPICTING SLOWLY INCREASING
MOISTURE ACROSS THE AREA WITH ISENTROPIC UPGLIDE ON THE SLIGHTLY
WARMER AIR PUSHING INTO THE REGION. THE SNOW SHOULD BE FAIRLY LIGHT
AT THE ONSET AS THE MOISTURE TRANSPORT VECTORS ARE NOT EXACTLY
NORMAL TO THE PRESSURE PLOTTED ON THE 300K ISOSURFACE AND THE MAIN
SYSTEM FORCING REMAINS SOUTH OF THE AREA. MODELS AGREE WITH QPF
BEING PAINTED OUT ACROSS THESE AREAS TO THE POINT THAT LIKELY POPS
ARE IN ORDER ESPECIALLY DURING THE TUESDAY AFTERNOON AND EVENING
HOURS. THE DEEPER MOISTURE AND FORCING PUSH INTO THE AREA BY TUESDAY
AFTERNOON AND TUESDAY EVENING AS SHOWN BY OVERLAYING 850-300MB Q-DIV
ALONG WITH RH THROUGH THAT LAYER. BOTH THE GFS AND EC ARE PAINTING
AROUND 0.3 INCHES OF QPF ACROSS THE EAST HALF OF THE U.P. AND AROUND
0.15 TO 0.20 ACROSS THE WEST HALF. THIS...ALONG WITH SNOW TO LIQUID
RATIOS ON THE ORDER OF 15-18:1 WOULD GIVE SNOWFALL TOTALS OF AROUND
2 TO 4 INCHES OVER THE WEST HALF WITH AROUND 3 TO 6 INCHES OVER THE
EAST HALF. THIS SYSTEM IS EXPECTED TO SHIFT THROUGH THE AREA
QUICKLY...WHICH SHOULD HELP TO KEEP SNOWFALL TOTALS IN CHECK. IT
STILL LOOKS LIKE THE SYSTEM WOULD HAVE SIGNIFICANT IMPACTS WITH THE
HEAVIEST SNOW EXPECTED TO OCCUR DURING THE TUESDAY AFTERNOON/EVENING
COMMUTE. NO HEADLINES AT THIS TIME...HOWEVER...AT A MINIMUM ADVISORY
SNOWFALL IS POSSIBLE OVER THE EAST HALF OF THE AREA.
WEDNESDAY THROUGH THURSDAY NIGHT...BOTH THE EC AND GFS AGREE ON AN
UPPER LEVEL TROUGH AXIS SLIDING ACROSS THE UPPER PENINSULA WEDNESDAY
AND WEDNESDAY NIGHT...WITH CONTINUED BROAD TROUGHING THROUGH
THURSDAY. THIS WILL ALLOW FOR MUCH COLDER THAN NORMAL TEMPERATURES
ACROSS THE AREA WITH MANY PLACES SEEING HIGH TEMPERATURES IN THE
UPPER SINGLE DIGITS ABOVE ZERO TO THE LOW TEENS. OVERNIGHT LOWS WILL
DROP TO THE TEENS BELOW ZERO ESPECIALLY WEDNESDAY NIGHT FOR INLAND
AREAS AS WINDS BECOME LIGHT AND ONLY SCATTERED LAKE EFFECT CLOUDS
EXPECTED. THE COLDER TEMPERATURES ALOFT ALONG WITH ANY ADDITIONAL
MOISTURE OFF LAKE SUPERIOR WILL ALLOW FOR LAKE EFFECT SNOW CHANCES
ACROSS PORTIONS OF THE U.P...MAINLY THROUGH THURSDAY. AGAIN...THE
EXACT LOCATION ALONG WITH INTENSITY WILL BE LARGELY TIED TO ANY
BREAKS IN THE ICE COVER ON LAKE SUPERIOR. THE FAVORED LOCATIONS
BASED SOLELY ON WIND WOULD BE FOR THE WEST TO WEST NORTHWEST WIND
FAVORED SNOW BELTS WITH A SURFACE HIGH PRESSURE SYSTEM PASSING TO
THE SOUTH OF THE REGION. GENERALLY...ANY LAKE EFFECT SNOW SHOULD
REMAIN FAIRLY LIGHT WITH 850MB TEMPERATURES FALLING TO -20C TO-25C
WEDNESDAY INTO THURSDAY. THIS WILL EFFECTIVELY MINIMIZE SNOW GROWTH
POTENTIAL AS THE DGZ BECOMES VERY SHALLOW AND LOW IN THE ATMOSPHERE.
KEPT THE POPS AT OR BELOW CHANCE THROUGH THIS FORECAST PERIOD...DUE
AGAIN TO THE EXTENSIVE ICE COVER. THURSDAY NIGHT...THE SURFACE HIGH
WILL SHIFT TO THE EAST OF THE AREA AS A SURFACE TROUGH APPROACHES
THE U.P. FROM THE WEST. THIS WILL EFFECTIVELY TURN WINDS SOUTH TO
SOUTHWESTERLY...ENDING ANY LAKE EFFECT SNOW CHANCES ACROSS THE U.P.
FRIDAY AND SATURDAY...STUCK WITH A CONSENSUS OF THE MODELS THROUGH
THIS TIME PERIOD AS MODELS ARE IN GOOD AGREEMENT IN THE OVERALL
PATTERN. SOUTHERLY FLOW AHEAD OF THE APPROACHING SURFACE TROUGH AND
ON THE BACK SIDE OF THE DEPARTING HIGH PRESSURE SYSTEM WILL ALLOW
TEMPERATURES TO MODERATE TOWARD THE UPCOMING WEEKEND...WITH
TEMPERATURES APPROACHING NORMAL VALUES...WHICH ARE RIGHT AROUND 30
FOR DAYTIME HIGHS AND THE UPPER SINGLE DIGITS FOR OVERNIGHT LOWS.
THE WEAK TROUGH SLIDING ACROSS THE AREA WILL BRING CHANCES OF LIGHT
SNOW TO THE AREA ONCE AGAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1245 PM EST SUN MAR 1 2015
SFC LOW PRES TROF AND ASSOCIATED -SHSN/MVFR CIGS WILL PASS ACROSS
THE AREA THIS AFTN. AT KCMX...A FEW PERIODS OF IFR VIS APPEAR LIKELY
THRU 19Z TO 20Z. OTHERWISE...ARRIVAL OF DRIER AIR BEHIND TROF SHOULD
BRING A RETURN OF VFR CONDITIONS TO KIWD/KCMX/KSAW DURING THE MID TO
LATE AFTN HRS. ANOTHER DISTURBANCE PASSING ACROSS THE AREA THIS
EVENING SHOULD GIVE A BOOST TO LAKE EFFECT -SHSN DESPITE A MOSTLY
ICE COVERED LAKE SUPERIOR. RECENT SW WINDS MAY HAVE OPENED UP AN
AREA OF WATER E OF THE APOSTLE ISLANDS. IF SO...SOME PERIODS OF IFR
CONDITIONS IN -SHSH MAY OCCUR AT KIWD THIS EVENING UNDER LOW-LEVEL
WNW FLOW. OTHERWISE...MVFR CONDITIONS SHOULD BE THE RULE AT
KIWD/KCMX TONIGHT WITH OCNL -SHSN. BACKING WINDS MON MORNING WILL
BRING A RETURN OF VFR CONDITIONS TO KIWD. AT KSAW...EXPECT VFR
CONDITIONS TO PREVAIL TONIGHT THRU MON MORNING UNDER DOWNSLOPE WNW
FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 406 AM EST SUN MAR 1 2015
NO GALES EXPECTED INTO NEXT WEEK. WSW WINDS TO 30 KTS EXPECTED ON
SUNDAY OVER WESTERN HALF OF LK SUPERIOR WITH NW WINDS TO 30 KTS
TUESDAY NIGHT INTO WEDNESDAY OVER THE EASTERN HALF OF LK SUPERIOR IN
WAKE OF A STRONGER LOW PRESSURE SYSTEM AND COLD FRONT THAT CROSS THE
UPPER GREAT LAKES ON TUESDAY. OTHERWISE...WINDS WILL BE 20 TO 25 KTS
THROUGH THE WEEK. THE STRONG WINDS WILL LIKELY ALTER THE COVERAGE OF
THE ICE SOMEWHAT ON LK SUPERIOR...BUT IN GENERAL EXPECT THE HIGHER
COVERAGE TO PERSIST AS DESPITE SOME WARMING...TEMPERATURES WILL STAY
BELOW FREEZING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1156 AM EST SUN MAR 1 2015
.AVIATION...
THE WIDESPREAD LIGHT SNOW WILL REMAIN SOUTH OF PTK THROUGH THE
DURATION OF THE AFTERNOON. SOME ENHANCED SUBSIDENCE AND DAYTIME
MIXING HAS ACTUALLY CLEARED THE LOW CLOUDS FROM PTK NORTHWARD. THERE
ARE HOWEVER A FEW AREAS OF MVFR STRATO CU NEAR LAKE MI AND ACROSS
PORTIONS OF WISCONSIN. A SFC TROUGH AXIS NOW OVER WISCONSIN WILL BE
DRIVEN ACROSS SE MI OVERNIGHT IN RESPONSE TO THE PASSAGE OF AN
UPPER LEVEL SHORT WAVE. THIS SHOULD ALLOW THESE LOWER CLOUDS
UPSTREAM TO FILTER BACK INTO SE MI THIS EVENING. SOME LOW LEVEL COLD
AIR ADVECTION TONIGHT ALONG THE SFC TROUGH WILL STEEPEN LOW LEVEL
LAPSE RATES AND WILL SUPPORT SOME GUSTINESS /AROUND 20 KNOTS/ WITH
THE WESTERLY WINDS OVERNIGHT.
FOR DTW...THE NORTHERN EDGE TO THE LIGHT SNOW HAS LIFTED BACK ACROSS
METRO LATE THIS MORNING. TRENDS IN RADAR...SFC OBS AND LATEST MODEL
DATA SUGGEST THE SNOW WILL PERSIST THROUGH ROUGHLY 22Z BEFORE
ENDING. AFTERNOON ACCUMULATIONS OF A HALF INCH TO AN INCH OF DRY
POWDERY SNOW SEEM POSSIBLE.
//DTW THRESHOLD PROBABILITIES...
* HIGH IN CEILINGS BELOW 5000 FT THIS AFTERNOON AND TONIGHT.
&&
.PREV DISCUSSION...ISSUED 907 AM EST SUN MAR 1 2015
UPDATE...
THE NORTHERN EDGE OF THE FRONTOGENETICALLY FORCED LIGHT SNOW NOW
EXTENDS FROM NORTH-CENTRAL ILLINOIS INTO SRN MONROE COUNTY. THE
LATEST RAP AND NAM12 SUGGEST A SLIGHT NORTHWARD SHIFT AND
REINTENSIFICATION OF THE MID LEVEL FGEN BETWEEN 18Z AND 21Z. THIS
SUPPORTS THE CURRENT FORECAST WHICH HOLDS FAIRLY HIGH POPS UP
THROUGH THE ANN ARBOR TO DETROIT CORRIDOR AND POINTS SOUTH. THE
EXPECTED BREVITY OF THE STRONGER FORCING REMAINS SUPPORTIVE OF
ADDITIONAL SNOWFALL ACCUMS OF AN INCH OR LESS.
SOUTHWEST FLOW OFF THE REMAINING OPEN WATERS OF LAKE MI HAS BEEN
ENOUGH TO GENERATE SOME LIGHT SNOW ACROSS WEST CENTRAL LOWER MI
THIS MORNING. A VEERING OF THE LOW FLOW TOWARD THE WEST HAS
BROUGHT SOME OF THIS LOW LEVEL MOISTURE INTO THE TRI CITIES
REGION. CONDITIONS APPEAR TO BE SUPERSATURATED WITH RESPECT TO
ICE WITHIN THESE CLOUDS WHICH IS LIKELY CAUSING SOME DECENT
SNOWFLAKE SIZE /ALSO SUGGESTED BY SOME OF THE VSBY REDUCTIONS/.
THE LATEST RADAR TRENDS SHOW A WEAKENING OF RETURNS. DIURNAL
MIXING INTO SOME DRIER AIR MAY ALSO ERODE SOME OF THIS LOW LEVEL
MOISTURE. IN LIGHT OF CURRENT OBS...AN UPDATE WILL HAVE TO BE
ISSUED TO AT LEAST CARRY SOME FLURRIES ACROSS THE SAGINAW VALLEY
TODAY.
PREV DISCUSSION...ISSUED 357 AM EST SUN MAR 1 2015
SHORT TERM...TODAY AND TONIGHT
SYNOPTIC SCALE ASCENT ANCHORED UNDER THE LEFT EXIT QUADRANT OF A
POWERFUL ZONAL JET AXIS AND WEAK SYSTEM RELATIVE ISENTROPIC ASCENT
ARE THE MECHANISMS RESPONSIBLE FOR THE BROAD FOOTPRINT OF LIGHT SNOW
ACROSS THE REGION. THE LEAD EDGE OF THE PRECIPITATION WAS ABLE TO
LIFT NORTHWARD THROUGH THE DETROIT METRO AREA PRIOR TO 6Z...TIMING
WELL WITH A COMPACT 850MB TEMPERATURE GRADIENT. NWP DATA SUPPORTS
THIS STEEPENED FRONTAL STRUCTURE TO CONTINUE TO LIFT NORTHEASTWARD
AWAY FROM THE CWA...MAKING IT AS FAR NORTHWARD AS CENTRAL LAKE HURON
AND SOUTHERN GEORGIAN BAY BY 12Z. AN ADDITIONAL STEEPEND FRONTAL
STRUCTURE RESIDES TO THE SOUTH OF THE STATE...NOW OVER CENTRAL
SECTIONS OF INDIANA AND OHIO. THIS FEATURE IS RESPONSIBLE FOR THE
HIGHER Z RETURNS AND LOWER VSBYS IN SURFACE OBSERVATIONS. MODELS
SUPPORT THIS BAROCLINIC ZONE TO REMAIN SOUTH OF THE AREA THROUGH THE
DURATION OF THE EVENT. WITH THIS IN MIND...EXPECTATIONS ARE FOR A
STATUS QUO TO SNOWFALL RATES THROUGH 12Z WITH VERY LIGHT SNOW
ACCUMULATIONS THIS MORNING.
WITH THE UPPER LEVEL JET FORCING AND LEAD MOISTURE ADVECTION
VACATING THE PREMISES...FORCING WILL THEN DISTILL DOWN TO WEAK
ISENTROPIC ASCENT. WHILE PERSISTENT...THERE IS SERIOUS QUESTION ON
WHETHER OR NOT THIS UPGLIDE WILL BE SUFFICENT IN CONTINUING TO
GENERATE MEASURABLE PRECIPATION. CURRENT RADAR MOSAIC DOES SHOW A
DEFINITIVE BACK EDGE OF THE PRECIPATION SHIELD...WITH DRY AIR
ALREADY ADVANCING THROUGH CHICAGOLAND AND INTO FAR SOUTHWESTERN
LOWER MICHIGAN. VARIOUS SOLUTIONS THEN SUGGEST IT WILL REQUIRE THE
AGEOSTROPHIC RESPONSE TO A POSITIVE D(MAG)/DT INCREASE OF THE UPPER
LEVEL JET MAX TO ALLOW PRECIPATION TO FILL BACK IN ACROSS FAR
SOUTHERN SECTIONS OF THE CWA FOR THE AFTERNOON. THIS IS EXPECTED TO
OCCUR BETWEEN 19-00Z. GIVEN THE TRENDS IN NUMERICAL OUTPUT IN
ADDITION TO THE RADAR DATA...WAS FAIRLY AGGRESSIVE IN LOWERING POPS
AND AMOUNTS FOR AREAS NORTH OF DETROIT. IN SUM TOTAL...SNOWFALL
ACCUMULATIONS OF 1 TO 2 INCHES WILL BE POSSIBLE FROM DETROIT
SOUTHWARD WITH AN INCH POSSIBLE BETWEEN THE M 59 AND I 94 CORRIDORS.
THE MAIN MIDLEVEL TROUGH AXIS AND NORTHERN STREAM WAVE WILL CATCH UP
TO LOWER MICHIGAN TONIGHT PASSING THROUGH THE CWA AFTER 6Z.
SHALLOW...LOWER TROPOSPHERIC COLD AIR ADVECTION IS FORECASTED TO
STEEPEN LAPSE RATES IN THE 1.5 TO 5.5 KFT AGL LAYER. THE UNSTABLE
PROFILE IN COMBINATION WITH PROGGED SATURATION WRT ICE AND CYCLONIC
VORTICITY ADVECTION SUPPORTS HYDROMETEOR PRODUCTION THE LATTER HALF
OF THE NIGHT. TOTAL LACK OF QPF SUPPORTS NOTHING MORE THAN A MENTION
OF FLURRIES AT THIS TIME.
LONG TERM...
MODEL TRENDS EXPLORED DURING THE 12Z CYCLE LARGELY HOLD TRUE FOR THE
00Z RUNS WITH A BIT LESS DISPARITY IN SOLUTIONS. ESSENTIALLY...THE
BROAD AND SOMEWHAT FLAT SOUTHERN EDGE OF THE EXISTING NOAM UPPER
TROUGH WILL REMAIN IN PLACE OVER THE CONUS AS A POTENT NORTHERN
STREAM SHORTWAVE NOW EXITING ALASKA TAKES A TRACK SOUTHEASTWARD
THROUGH THE PRAIRIE PROVINCES AND THEN EAST ALONG THE SOUTHERN EDGE
OF HUDSON BAY DURING THE FIRST PART OF THIS WEEK. THIS WILL STEER
SOUTHERN STREAM ENERGY INTO THE AREA ON A RATHER FLAT TRAJECTORY. IN
THE MEANTIME...WHILE THE ARCTIC AIRMASS IN PLACE TO OUR NORTH AS
ERODED TO SOME EXTENT DURING THE PAST DAY OR TWO...IT STILL REMAINS
EXPANSIVE ENOUGH TO MAINTAIN A TIGHT TEMPERATURE GRADIENT ACROSS THE
GREAT LAKES. BETWEEN THESE TWO FACTORS...CHANCES ARE THAT COLD AIR
WILL BE DIFFICULT TO DISPLACE OVER THE AREA. THIS SHOULD LEAD TO A
FAIR AMOUNT OF THE PRECIPITATION FROM THIS SYSTEM FALLING AS SNOW.
EVEN NAM12/GFS NOW SUPPORT A BASICALLY ALL SNOW EVENT FOR THE FAR
NORTHERN CWA.
THE MAIN QUESTION WILL BE THE TIMING AND PLACEMENT OF A CHANGEOVER
TO SLEET/FREEZING RAIN AND THEN RAIN IN SOME LOCATIONS BY AFTERNOON
AS THE SURFACE LOW REFLECTION OF THIS SYSTEM CROSSES THE AREA. WILL
ONLY MAKE MINOR ADJUSTMENTS TO THE FORECAST AS MODELS DO NOT SUPPORT
A STRONG SHIFT EITHER NORTH OF SOUTH IN THE PRECIPITATION TYPE
FORECAST. GENERALLY...AREAS FROM I-69 NORTH ARE EXPECTED TO REMAIN
LARGELY SNOW OR SLEET THROUGHOUT THE EVENT. FOR THE REST OF THE
FORECAST AREA...PRECIPITATION WILL START AS SNOW TUESDAY MORNING
WITH A GRADUAL CHANGEOVER TO SLEET/FREEZING RAIN FROM SOUTH TO NORTH
AS SOME MILDER AIR WORKS INTO LOWER MICHIGAN AND THEN A CHANGE TO
RAIN THROUGH THE SOUTHERN THIRD TO HALF OF THE AREA AS SURFACE AND
BOUNDARY LAYER TEMPERATURES CLIMB INTO THE MID/UPPER 30S. OVERALL
PRECIPITATION INTENSITY FORECASTS FROM THE MODELS SUGGEST ONLY LIGHT
TO MODERATE PERIODS OVER A 8-10 HOUR PERIOD DURING THE DAY TUESDAY
SO WHILE IT WILL MOST LIKELY BECOME RATHER MESSY IN TERMS OF TRAVEL
THIS IS NOT A PARTICULARLY POWERFUL WINTER STORM.
AS FOR TEMPERATURES...RELATIVELY MILD READINGS AS COMPARED TO THE
PAST FEW WEEKS CAN BE EXPECTED MONDAY INTO TUESDAY. STILL WITH
AVERAGE HIGHS IN THE UPPER 30S/LOWER 40S FOR EARLY MARCH THE AREA
WILL REMAIN AOB AVERAGE EVEN DURING THIS PERIOD. MUCH COLDER AIR
WILL THEN DUMP INTO THE AREA BEHIND THIS SYSTEM DURING THE LAST PART
OF THE WEEK AS ANOTHER ARCTIC HIGH PRESSURE SYSTEM BUILDS SOUTHEAST
THROUGH THE EASTERN CONUS WITHIN AMPLIFYING UPPER TROUGHING PATTERN
THAT DEVELOPS AS ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY DIGS
INTO AREA BEHIND THE EXITING STORM SYSTEM. AS THIS TROUGH PROGRESSES
EASTWARD BY THE END OF THE FORECAST PERIOD...A MODERATION IS
EXPECTED INTO NEXT WEEKEND WITH TEMPERATURES AT LEAST CLIMBING BACK
INTO THE 30S.
MARINE...
A WEAK TO MODERATE SURFACE PRESSURE GRADIENT WILL MAINTAIN WINDS
BELOW 20 KNOTS THROUGH SUNDAY NIGHT. A COLD FRONT WILL GRAZE THE
NORTHERN PORTIONS OF LAKE HURON MONDAY AND BRING A FRESH NORTHWEST
BREEZE WITH GUSTS TO 30 KNOTS POSSIBLE AS COLD AND MARGINALLY
UNSTABLE CONDITIONS DEVELOP. HIGH PRESSURE WILL THEN BUILD INTO THE
AREA FROM THE WEST WITH NEARLY CALM CONDITIONS TAKING HOLD MONDAY
NIGHT BEFORE MODERATE SOUTHERLY WINDS EXPAND INTO THE REGION IN
ADVANCE OF THE NEXT STORM SYSTEM DUE INTO THE AREA BY TUESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...CB
LONG TERM....DG
MARINE.......DG
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1140 AM EST SUN MAR 1 2015
LATEST UPDATE...
HYDRO
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1125 AM EST SUN MAR 1 2015
FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR
CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT
KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS
TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC
TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE
TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY
WITH WNW WINDS AOB 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 1140 AM EST SUN MAR 1 2015
THE FORECAST GETS A LITTLE TRICKY IN THE UPCOMING WEEK WITH THE
APPROACHING SYSTEM GOING INTO TUESDAY. TEMPERATURES COULD VARY
QUITE A BIT RIGHT ALONG WITH EXPECTED PRECIPITATION TOTALS AND
PRECIPITATION TYPE. THE CURRENT GUIDANCE SUGGESTS WE COULD GET A
BIT FURTHER INTO MILDER AIR (NEAR NORMAL) AND ADD MORE LIQUID
PRECIPITATION AS OPPOSED TO SNOW. OVERALL....IT IS NOT A DRASTIC
WARM UP AND AMOUNTS MAY REMAIN AROUND OR BELOW HALF AN INCH. THIS
COULD MOSTLY BE SOAKED UP BY CURRENT SNOW PACK. WITH LOW RIVER
LEVELS AND GIVEN SITUATION...THIS SHOULD NOT RAISE ANY IMMEDIATE
CONCERN BUT WILL BE ADDED LIQUID TO BE CONSIDERED IN FORECASTS
DOWN THE ROAD.
THE GOOD NEWS IS THAT THE SYSTEM LAST NIGHT INTO TODAY WAS QUITE
LACKLUSTER IN REGARDS TO TOTALS. THEREFORE...WHAT WE MISSED LAST
NIGHT WILL JUST SUBTRACT FROM THE OVERALL WEEKLY AMOUNTS WE WERE
LOOKING AT YESTERDAY. THOUGH IT WAS NOT ANYTHING TOO HEAVY TO
BEGIN WITH IT JUST RAISES CONFIDENCE THAT ANY UPWARD TRENDS IN
TEMPERATURES WILL NOT HAVE AS MUCH OF A NEGATIVE IMPACT.
CONDITIONS ARE EXPECTED TO REMAIN STABLE FOR NOW AND IN THE NEAR
TERM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1125 AM EST SUN MAR 1 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EST SUN MAR 1 2015
LIGHT SNOW WILL CONTINUE TO WIND DOWN TODAY AS A WAVE OF LOW
PRESSURE MOVES EAST. ANOTHER STORM WILL HEAD TOWARD LOWER MICHIGAN
AND BRING A MIX OF SNOW SLEET FREEZING RAIN AND PERHAPS RAIN
TUESDAY...BUT SHOULD BE DONE BY LATE TUESDAY. ANOTHER SHOT OF ARCTIC
AIR WILL FOLLOW AND HIGHS WILL REMAIN IN THE TEENS THURSDAY BUT WILL
WARM INTO THE MID 30S BY NEXT WEEKEND.
&&
.UPDATE...
ISSUED AT 934 AM EST SUN MAR 1 2015
I UPDATED THE GRIDS AND FORECAST TO BETTER DEPICT THE CURRENT SNOW
SHOWERS FROM GRR TO THE LAKE SHORE. THESE ARE NOT SHOWN BY ANY OF
THE MODELS BUT USING THE 1000/950 OMEGA AND CONVERGENCE FIELDS FROM
THE RAP AND NAM IT CAN BE SEEN WHY THESE SHOWERS ARE HAPPENING.
THE CONVERGENCE CAUSING THESE SNOW SHOWERS GOES AWAY BY NOON SO BY
THEN THE SNOW SHOWERS NEAR GRR TO THE LAKE SHORE SHOULD COME TO AN
END. ACCUMULATIONS WILL MOSTLY BE UNDER A HALF INCH. OTHERWISE THE
REST OF THE FORECAST REMAINS UNCHANGED.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
FORECAST CONCERNS THIS MORNING DEAL WITH THE ONGOING LIGHT SNOW AND
THE MIXED PCPN EVENT TUESDAY. TWEAKED PCPN TYPE GRIDS TUESDAY AND
POPS TODAY...OTHERWISE MUCH OF THE FORECAST WAS UNCHANGED.
REGIONAL RADAR SHOWS LIGHT SNOW BEGINNING TO WIND DOWN ACROSS LOWER
MICHIGAN. THE SYNOPTIC SNOW SOUTH M-46 WILL LIKELY DIMINISH BEFORE
THE SW LAKE EFFECT SNOW ONGOING NORTH OF MKG...BUT EVEN THAT WILL
DIMINISH LATE THIS MORNING OR EARLY THIS AFTERNOON. ANY ACCUMS WILL
BE A HALF INCH OR LESS.
THE NEXT SYSTEM WILL ARRIVE EARLY TUESDAY...PERHAPS LATE MONDAY
NIGHT...AND BRING A MIX OF FREEZING RAIN/SLEET/SNOW/RAIN. THIS
SYSTEM IS A FAIRLY DYNAMICAL ONE AND PROGD TO PUSH A 70KT LLJ ACROSS
OHIO TUESDAY AND DRAWING ABUNDANT MOISTURE NORTHWARD. ISENTROPIC
LIFT IS VERY IMPRESSIVE ON THE 290K SFC WITH 40-50KTS PERPENDICULAR
TO THE PRESSURE SFCS. THIS WILL RESULT IN RAPID SATURATION EARLY
TUESDAY AND QUICK PCPN DEVELOPMENT. GIVEN THE COLD AIR IN PLACE ALL
OF THE PCPN WILL BEGIN AS SNOW. HOWEVER AS THE MID LEVELS
WARM...WE/LL SEE A CHANGE OVER TO FREEZING RAIN AND SLEET. MUCH OF
THE FREEZING RAIN WILL OCCUR SOUTH OF I-94. BASICALLY NORTH OF M-46
ALL OF THE PCPN WILL REMAIN AS SNOW. THE ECMWF AND GFS THERMAL
PROFILES WERE THE MOST SIMILAR WITH THE NAM SHOWING A BIT MORE
PRONOUNCED WARMING AT H85 LATE TUESDAY MORNING. IF THE NAM IS
CORRECT WE COULD SEE A BIT MORE FREEZING RAIN CREEP UP TOWARD I-96.
THE DRY SLOT QUICKLY WORKS IN FROM THE SOUTHWEST TUESDAY MID
AFTERNOON SO PCPN WILL EITHER END QUICKLY OR TURN TO
DRIZZLE/FREEZING DRIZZLE.
OVERALL...SNOW POTENTIAL LOOKS TO BE NEAR 3-4 INCHES FROM I-96
NORTHWARD WITH AN INCH OR TWO SOUTH OF THAT. ICE POTENTIAL LOOKS
LESS THAN A TENTH...BUT STILL ENOUGH TO CAUSE SOME TRAVEL ISSUES.
WHERE 2M TEMPERATURES DO WARM ABOVE FREEZING OVER THE SRN
CWA...SECONDARY ROADS THAT ARE STILL VERY COLD WILL REMAIN BELOW
FREEZING AND EXACERBATE THE FREEZING RAIN POTENTIAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 AM EST SUN MAR 1 2015
ANY LINGERING PRECIPITATION TUESDAY NIGHT SHOULD BE VERY LIGHT AS
THE SYSTEM RACES AWAY QUICKLY TO THE NORTHEAST AND THE DEEP MOISTURE
DEPARTS. BREEZY WEST WINDS WILL SEND IN COLDER AIR WITH TEMPERATURES
FALLING INTO THE TEENS/LOWER 20S BY EARLY WEDNESDAY MORNING.
YET ANOTHER ROUND OF BITTER COLD ARCTIC AIR IS IN STORE FOR
WEDNESDAY AND THURSDAY AS H8 AIR AROUND -24C VISITS THE STATE.
SCATTERED LAKE EFFECT SNOW SHOWERS ARE A GOOD BET... PARTICULARLY ON
WEDNESDAY BEFORE SURFACE RIDGING BUILDS IN. TYPICALLY AS WE MOVE
INTO MARCH THE CHARACTER OF LAKE EFFECT IN THE DAYLIGHT HOURS IS
OPEN CELLULAR COVERING MUCH OF THE AREA RATHER THAN FOCUSED JUST
ALONG THE LAKESHORE. WOULD THEREFORE NOT EXPECT ANY SIGNIFICANT SNOW
ACCUMULATIONS ALTHOUGH SOME BRIEFLY INTENSE SNOW SHOWERS ARE
POSSIBLE ACROSS THE ENTIRE AREA.
ARCTIC AIR MASS/NRN STREAM LIFTS OUT LATE IN THE WEEK. A FLATTER
FLOW ALOFT AND SOUTHWEST LOW LEVEL FLOW LEADS TO MODERATING
TEMPERATURES FOR FRIDAY AND SATURDAY HOWEVER STILL A BIT BELOW
NORMAL. THE NORMAL HIGHS FOR NEXT WEEKEND ARE AROUND 40.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1125 AM EST SUN MAR 1 2015
FAIRLY EXTENSIVE LOW CLOUD COVER WILL RESULT IN PRIMARILY MVFR
CONDITIONS THIS AFTERNOON. SOME LIGHT SNOW SHOWERS WILL LINGER AT
KMKG INTO THE AFTERNOON BEFORE GRADUALLY DISSIPATING.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR AT ALL THE TERMINALS
TONIGHT AS WINDS SHIFT TO THE WEST/NORTHWEST BEHIND A WEAK SFC
TROUGH. DRIER AIR WILL MOVE IN OVERNIGHT AND ALLOW CIGS TO IMPROVE
TO VFR. THE VFR CONDITIONS WILL THEN CONTINUE THROUGH 18Z MONDAY
WITH WNW WINDS AOB 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 1132 AM EST SAT FEB 28 2015
CONDITIONS ON AREA RIVERS AND STREAMS REMAIN STABLE. THIS IS
EXPECTED TO CONTINUE TO BE THE CASE THROUGH AT LEAST THE NEXT
COUPLE OF DAYS.
THE PATTERN WILL BECOME MORE ACTIVE AS WE GET INTO
THE SECOND HALF OF THE WEEKEND AND INTO NEXT WEEK. THE EXTREME
COLD THAT HAS BEEN ALL TOO STUBBORN WILL BEGIN TO RELEASE ITS GRIP
ON THE REGION. AS A RESULT...GRADUALLY WARMER TEMPERATURES WILL
MAKE THEIR WAY IN THROUGH TUESDAY. WHILE THERE IS SOME QUESTION TO
THE EXTENT OF THE WARMTH IT IS STILL NOT ANTICIPATED TO CREATE
MANY ISSUES AS COLD AIR QUICKLY MOVES BACK IN DURING THE MIDDLE
OF THE WEEK. TOTAL PRECIPITATION AMOUNTS SHOULD HOVER AROUND A
HALF INCH THROUGH THE NEXT SEVEN DAYS WITH MOST OF THIS COMING
IN THE TUESDAY SYSTEM. RIVERS WILL BE MONITORED THROUGH THE NEXT
SEVERAL DAYS IN THAT CASE THAT ANY VARIABILITY IS SENSED.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...LAURENS
HYDROLOGY...JAM
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1129 AM CST SUN MAR 1 2015
.SYNOPSIS...
ISSUED AT 347 AM CST SUN MAR 1 2015
AT 09Z...SURFACE HIGH PRESSURE EXTENDED FROM THE NEW ENGLAND
STATES...MIDWEST...INTO THE NORTHERN PLAINS. SKIES WERE MOSTLY
CLOUDY ACROSS WESTERN NEBRASKA. WEAK RADAR RETURNS INDICATED FROM
PORTIONS OF THE PANHANDLE INTO THE WESTERN SANDHILLS. WITH THE
EXCEPTION OF PINE RIDGE REPORTING 3SM -SN OVC035...CEILINGS ACROSS
WRN NEBR ARE RELATIVELY HIGH AT 8K-10K FEET AGL...WITH FLURRIES
UNLIKELY.
TEMPERATURES HOLDING FROM 15 TO 20 ABOVE BENEATH THE CLOUDINESS.
WINDS WERE LIGHT AND VARIABLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 347 AM CST SUN MAR 1 2015
FOR TODAY...THE ARCTIC AIRMASS IMPACTING WESTERN NEBRASKA THE PAST
FEW DAYS WILL LOOSE ITS TIGHT GRIP. TEMPERATURES AT H85 WILL
MODERATE TO -4C AT IML AND -9C AT ONL. MIXING DOWN THESE
TEMPERATURES TO BRING HIGHS NEAR 35 AT ONL...36 AT IML AND BBW TO 32
AT GORDON. THESE HIGHS SLIGHTLY WARMER THAN A 50/50 MET/MAV GUIDANCE
BLEND. IF FACT THE LATEST RAP13 AND HRRR IN CLOSE AGREEMENT ON HIGHS
AND WERE USED AS A BASIS FOR FORECAST HIGHS. EXPECTING CLEARING
SKIES FROM NORTH TO SOUTH TODAY..WITH THE NCTRL BECOMING MOSTLY
SUNNY BY LATE MORNING...WITH SWRN NEBR BECOMING PARTLY CLOUDY IN THE
AFTN. WINDS TO BECOME NORTHWEST TODAY AT 5 TO 15 MPH NCTRL AND 5 TO
10 MPH SOUTH.
FOR TONIGHT...A POSITIVELY TILTED TROUGH ACROSS NEVADA INTO SRN
CALIF. DOWNSTREAM OF THIS UPPER TROUGH...A BAND OF 125KT WINDS AT H3
WILL EXTEND FROM SRN CALIF...ACROSS UTAH...NRN CO...AND NEBRASKA.
WESTERN NEBRASKA WILL BE IN SWRLY FLOW ALOFT. WAA AT H7 WILL ADVANCE
FROM ERN CO INTO SWRN NEBR OVERNIGHT. A SLIGHT CHANCE FOR SNOW IS
SUPPORTED ACROSS SWRN NEBR BY THE MODELS...ESPECIALLY THE 00Z
NAM...00Z GEM AND 03Z SREF. LOWS TONIGHT MOSTLY TO RANGE FROM THE
MID TEENS NCTRL TO THE UPPER TEEN TO NEAR 20 SOUTHWEST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 347 AM CST SUN MAR 1 2015
12Z MONDAY AND BEYOND. THE PRIMARY FOCUS OF THE EXTENDED REMAINS
CENTERED ON PRECIPITATION CHANCES BEGINNING LATE MONDAY
EVENING...POTENTIALLY LASTING INTO THE AFTERNOON HOURS ON TUESDAY.
THE MID RANGE MODELS CONTINUE TO ADVERTISE A SOLUTION IN WHICH A
NORTHERN STREAM SHORTWAVE TROUGH WILL AMPLIFY SOUTHEASTWARD ACROSS
THE CANADIAN PRAIRIES AND NORTHERN PLAINS LATE MONDAY NIGHT INTO
TUESDAY WHILE ADDITIONAL SHORTWAVE ENERGY ROTATES NORTHEAST FROM THE
DESERT SW TOWARD THE CENTRAL PLAINS. AS THE NORTHERN STREAM TROUGH
AMPLIFIES...A STRONG ARCTIC FRONT WILL DIVE SOUTH ACROSS THE HIGH
PLAINS AND ADJACENT AMERICAN PRAIRIES...REACHING NORTHWEST NEBRASKA
DURING THE PRE-DAWN HOURS TUESDAY. THE MEDIUM RANGE MODELS ARE AT
ODDS WITH THE TIMING OF THE FRONT THEREAFTER. THE 01.00Z ECMWF
SEEMS TO BE A GOOD COMPRISE AT THIS POINT AS THE 00Z NAM IS ON THE
SLOWER SIDE OF THE FORECAST ENVELOPE...AND THE GFS REMAINS VERY
PROGRESSIVE. REGARDLESS...THE CURRENT FORECAST CALLS FOR EARLY
HIGHS TUESDAY MORNING FOR MUCH OF THE FORECAST AREA...WITH A
NON-DIURNAL TREND INTO THE AFTERNOON AND EVENING HOURS AS THE FRONT
SHOULD BE THROUGH THE CWA BY MIDDAY. DESPITE THE TIMING ISSUES WITH
THE FRONT...THE MODELS HAVE A GOOD HANDLE ON THE QPF FIELDS AS ALL
SEEM TO TARGET THE HIGHEST POPS ACROSS OUR NORTHERN ZONES. MOISTURE
ADVECTION IS SHOWN TO BE SOLID AS A SOUTHERLY LOW LEVEL FLOW
DEVELOPS OFF THE GULF AND ARCS NORTH INTO THE CENTRAL HIGH PLAINS ON
MONDAY. AS HEIGHTS FALL WITH THE APPROACHING SHORTWAVE/S/...DPVA
WILL SPREAD EAST ACROSS NEBRASKA AND WORK ON UPGLIDE TARGETING THE
285-300K SURFACES. ACCUMULATING SNOW IS EXPECTED. AS OF NOW...A
CONSENSUS OF QPF WOULD SUGGEST UPWARDS OF A TENTH TO POSSIBLY TWO
TENTHS OF AN INCH OF QPF ACROSS OUR NORTHERN ZONES. IT IS IN THIS
AREA WHERE THE AGEOSTROPHIC RESPONSE TO A PASSING 150KT ULJ WOULD
PROMOTE FRONTOGENETIC BANDING AND ENHANCED SNOW RATES. USING THE
HIGHER END OF THE FORECAST QPF...WOULD ONE EXPECT ACCUMULATIONS OF 1
TO 3 INCHES ACROSS NORTHERN NEBRASKA...WITH POSSIBLY HIGHER AMOUNTS
WHERE THE BANDED PRECIPITATION OCCURS /NW NEB./ FOR NOW...WILL UP
POPS ACROSS OUR NORTHERN ZONES AND CONTINUE TO MENTION SNOW CHANCES
IN THE HWO...BUT BEGIN TO HIGHLIGHT POSSIBLY HEAVIER AMOUNTS ACROSS
OUR NORTHWEST AND NORTHERN ZONES. FURTHER SOUTH ACROSS THE CENTRAL
SANDHILLS AND SOUTHWEST NEBRASKA...SNOW CHANCES ARE LESS
CERTAIN...SO WILL PREDOMINATELY KEEP POPS AT CHANCE OR LESS FOR
NOW. ONE POTENTIAL IMPACT TO THE CENTRAL AND SOUTHEASTERN PORTIONS
OF THE FORECAST AREA MONDAY NIGHT IS POSSIBLY A BRIEF PERIOD OF
FREEZING RAIN. THE MODELS ALL AGREE THAT MID LEVEL WAA AHEAD OF THE
SHORTWAVES WILL BE STRONG...WITH H8 TEMPS SHOWN TO BE IN EXCESS OF
5C AT KLBF MONDAY EVENING. THE NAM IS LEADING THE CHARGE WITH THE
ZR POTENTIAL...HOWEVER IT IS SUSPECT AS IT IS DEEMED TOO COLD AT THE
SURFACE. STRONG SOUTHERLY LL WAA AND MIXING SHOULD HELP KEEP ABOVE
0C INTO THE PRE-DAWN HOURS ACROSS THE EASTERN THIRD OF THE FA. SO
FOR NOW...NO ZR WAS PLACED IN THE FORECAST...BUT WE WILL NEED TO
CONTINUE TO MONITOR. WILL GO WITH RAIN OR SNOW IN THESE AREAS.
BEYOND TUESDAY EVENING...THE FORECAST GENERALLY CALLS FOR DRY
CONDITIONS. TEMPERATURES WILL BE COLD MID-WEEK...BUT THE LONG RANGE
SOLUTIONS ALL AGREE THAT A WARMING TREND WILL TAKE PLACE OVER THE
CENTRAL PLAINS. RISING HEIGHTS AND WESTERLY DOWNSLOPING LOW LEVEL
FLOW WILL HELP PUSH HIGHS BACK INTO THE 40S AND 50S BY THE END OF
THE WORK WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1129 AM CST SUN MAR 1 2015
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH TONIGHT. MID LEVEL CLOUDS WILL BEGIN TO MOVE INTO
THE AREA FROM THE SOUTH MONDAY MORNING. LIGHT SNOW IS POSSIBLE AT
KLBF AFTER 02/10Z...WHICH MAY TEMPORARILY CREATE MVFR CEILINGS
AND/OR VISBY. WIND WILL LIKELY BE THE HIGHER CONCERN FOR KLBF AND
KVTN AS GUSTS ABOVE 20 KNOTS ARE EXPECTED BY LATE MORNING MONDAY.
&&
.HYDROLOGY...
ISSUED AT 347 AM CST SUN MAR 1 2015
THE 07Z RIVER GAGE READINGS INDICATED AN ICE JAM CONTINUED ON THE
NORTH PLATTE RIVER NEAR LEWELLEN UPSTREAM OF LAKE MCCONAUGHY WITH
THE STAGE REMAINING SLIGHTLY ABOVE THE 7.5 FOOT FLOOD STAGE. A
COUPLE OF SITES ON THE MAIN STEM OF THE PLATTE SHOW ICE JAM SIGNALS
AS WELL...THOUGH WELL BELOW FLOOD STAGE. TEMPERATURES WILL WARM TO
NEAR 35 AT LEWELLEN TODAY AND 40 FOR MONDAY...BUT WILL PROBABLY NOT
BE ABOVE FREEZING LONG ENOUGH TO AFFECT THE ICE. HIGHS ONLY IN THE
LOW TO MID 20S TUESDAY AND WEDNESDAY AND LOWS IN THE SINGLE DIGITS
WILL LIKELY CAUSE ICE JAMMING TO PERSIST OR WORSEN SLIGHTLY AT
LEWELLEN AND COULD DEVELOP IN OTHER RIVER IN WRN NEBR. SIGNIFICANT
WARMING IS FORECAST THURSDAY AND BEYOND THAT WILL AID IN BREAKING UP
THE ICE JAM. CLIMATOLOGICALLY...ICE JAMS ARE RARE GOING INTO MARCH.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...DS
HYDROLOGY...ROBERG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 PM EST SUN MAR 1 2015
.SYNOPSIS...
A WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN THROUGH MONDAY
MORNING. A COLD FRONT WILL MOVE THROUGH MONDAY AFTERNOON FOLLOWED BY
ANOTHER WEDGE OF COOL HIGH PRESSURE FOR TUESDAY. TEMPERATURES ARE
EXPECTED TO BE WELL ABOVE NORMAL ON WEDNESDAY AHEAD OF A STRONG COLD
FRONT THAT WILL MOVE ACROSS THE AREA WEDNESDAY NIGHT. A WAVE OF LOW
PRESSURE MAY DEVELOP ALONG THE FRONT...KEEPING THE WEATHER UNSETTLED
THROUGH THURSDAY. CHILLY HIGH PRESSURE WILL BUILD ACROSS THE AREA
FRIDAY AND PERSIST THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 200 PM SUNDAY...ISENTROPIC LIFT OVER THE AREA THIS AFTERNOON
WILL GRADUALLY WEAKEN AS HIGH WEDGING DOWN THE COAST IS SHIFTED EAST
BY WESTERLY FLOW ALOFT. ALTHOUGH THE WEDGE WILL BE IN THE PROCESS OF
BREAKING DOWN OVERNIGHT...LIGHT WESTERLY FLOW BECOMES PREVALENT BY
DAYBREAK...LOW LEVEL CLOUDS AND MOISTURE WILL LINGER THROUGH THE END
OF THE PERIOD. FORECAST SOUNDINGS CONTINUE TO SHOW THE COLUMN UNDER
1500 FT ALMOST FULLY SATURATED. WHILE THERE IS NO REAL SOURCE OF
LIFT...AND EVEN SOME WEAK SUBSIDENCE ...THE PRESENCE OF ABUNDANT LOW
LEVEL MOISTURE TRAPPED UNDER THE LOW LEVEL INVERSION WILL NOT ONLY
RESULT IN STRATUS HANGING AROUND ALL NIGHT BUT COULD LEAD TO PATCHES
OF MIST OR DRIZZLE. THE PREVIOUSLY MENTIONED LACK OF FORCING SHOULD
PREVENT ANY MEASURABLE PRECIP SO BY MIDNIGHT HAVE MOST AREAS UNDER
MENTIONABLE POP THRESHOLDS. FORECAST SOUNDINGS AND MODEL LAYER DATA
KEEP BOUNDARY LAYER WINDS JUST HIGH ENOUGH TO PREVENT DEVELOPMENT OF
WIDESPREAD FOG...THOUGH PATCHES OF 4-5SM ARE CERTAINLY POSSIBLE.
TEMPERATURES WILL BE NEAR CLIMO OVERNIGHT WITH WESTERLY FLOW AND
CLOUDS KEEPING LOWS IN THE UPPER 30S TO LOWER 40S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...PROGRESSIVE REGIME THROUGH THE PERIOD. ONE
WEDGE OF HIGH PRESSURE WILL COMPLETELY BREAK DOWN MON MORNING
AHEAD OF THE NEXT COLD FRONT WHICH WILL MOVE ACROSS THE EASTERN
CAROLINAS MON AFTERNOON. THERE COULD BE SOME VERY LIGHT
PRECIPITATION AROUND ON MON...DIFFICULT TO SAY WHETHER ISOLATED
SPOTS WILL RECEIVE MEASURABLE RAINFALL. WILL CONFINE POPS TO NEAR 20
PERCENT OR JUST BELOW ON MON. A VERY PRONOUNCED NEAR SURFACE
INVERSION WILL KEEP LOW CLOUDS/FOG AROUND FOR THE FIRST PART OF THE
MORNING. THIS STRONG INVERSION DOES FINALLY BREAK DOWN AND SO WE
MAY AT LEAST SEE SOME GLIMPSES OF SUNSHINE DURING MON.
ONCE THE COLD FRONT MOVES THROUGH...ANOTHER WEDGE OF HIGH PRESSURE
WILL BUILD ACROSS THE CAROLINAS MON NIGHT INTO TUE AS HIGH PRESSURE
MOVES OUT OF THE MID-WEST AND ACROSS THE MID-ATLANTIC STATES. THIS
WILL LOCK IN LOW-LEVEL MOISTURE...WITH WIDESPREAD LOW CLOUDS
EXPECTED TO REDEVELOP LATER MON NIGHT AND THEN PERSIST INTO TUE AS
COLD AIR ADVECTION REDEVELOPS ON LOW-LEVEL NE FLOW. ISENTROPIC
UPGLIDE IS EXPECTED TO DEVELOP MON NIGHT AS MOIST S TO SW OR WSW
WINDS ABOVE 2 KFT TOP THE COOL DOME OF AIR NEAR THE SURFACE.
ALSO...A COASTAL TROUGH IS EXPECTED TO DEVELOP LATE MON NIGHT AND
TUE. THIS TROUGH WILL LIFT ATLANTIC MOISTURE OVER THE TOP OF THE
LOW-LEVEL INVERSION AND NOT ONLY KEEP SKIES CLOUDY...BUT BRING MORE
WET WEATHER. THERE IS NO RISK OF ANY FREEZING OR FROZEN
PRECIPITATION. QPF AMOUNTS WILL BE LIGHT.
THE HIGH DOES MOVE OFF THE COAST LATE TUE AND TUE NIGHT AND THE
MODELS ARE IN A HURRY TO BREAK DOWN THE WEDGE. ALTHOUGH IT MAY
EVOLVE SLOWER THAN CURRENTLY PORTRAYED...IT DOES LOOK LIKE THE NEXT
COLD FRONT WILL BE STRONGER AND ITS PROXIMITY SHOULD ALLOW A WARMER
RETURN FLOW TO DEVELOP OVERNIGHT AT ALL LEVELS. WILL SHOW TEMPS
TRENDING HIGHER THROUGH THE NIGHT AS INCREASINGLY SOUTHERLY WINDS
DEVELOP.
TEMPS WILL BE BELOW NORMAL THROUGH THE PERIOD WITH MON LIKELY
CONSIDERABLY WARMER THAN TUE. HIGHS MON WILL BE IN THE UPPER 50S AND
LOWER 60S WITH SOME MID 60S POSSIBLE ALONG THE SOUTH SANTEE RIVER
AREA. WE WILL HAVE TO SUBTRACT A GOOD 10 DEGREES FROM THOSE VALUES
ON TUE. LOWS WILL BE MAINLY IN THE UPPER 30S AND LOWER 40S MON
NIGHT. LOWS TUE EVE WILL BE VERY NEAR THE HIGHS OF THE DAY AND
THEN MOVE UPWARDS FROM THERE DURING THE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...VERY WARM START TO THE EXTENDED PERIOD WITH
WEDNESDAY BEING THE WARMEST DAY IN QUITE A WHILE. UPPER RIDGE WILL
HOLD ON UP THROUGH THE SOUTHEAST AS DEEP TROUGH DIGS DOWN THROUGH
THE MID WEST. THIS WILL AID IN KEEPING A DRIER AND WARMER DAY OVER
THE COASTAL CAROLINAS. ALTHOUGH OVERALL MOISTURE THROUGH THE COLUMN
IS GENERALLY HIGH WITH UP TO 1.3 INCHES OF PCP WATER WED
MORNING...THE SOUNDINGS AND MOISTURE PROFILES KEEP IT CONFINED TO
VERY LOW LEVELS AND VERY HIGH WITH A DECENT DRY LAYER THROUGH THE
MID LEVELS. THIS MAY ALLOW SOME BREAKS IN THE CLOUDS TO HELP PUSH
TEMPS WELL INTO THE 70S. THE COAST WILL NOT BE AS FORTUNATE AS
SOUTHERLY FLOW WILL BRING THE COOLER OCEAN AIR OVER THE BEACHES
ADVECTING INLAND A BIT. ALSO THE POTENTIAL FOR SEA FOG WILL EXIST AS
THE WARMER AIR RUSHES OVER THE COOLER WATERS. BY LATE WED SHWRS WILL
INCREASE AS COLD FRONT DRAWS CLOSER. WILL KEEP LOW END POPS OVER
PORTIONS OF AREA...MAINLY INLAND ON WED BUT EXPECT BEST CHC OF PCP
TO COME WED EVE INTO THURS. A STRONG COLD FRONT WILL CROSS THE AREA
WED NIGHT WITH PLENTY OF CAA TO FOLLOW. SEEMS LIKE MODELS ARE
COMING BACK TO AN EARLIER FROPA FOR WED NIGHT INSTEAD OF THURS. MAY
SEE MAX TEMPS FOR THURS AT MIDNIGHT WED NIGHT BEFORE DROPPING BEHIND
FRONT...ESPECIALLY ALONG COASTAL LOCATIONS WHERE FRONT WILL PASS
THROUGH AFTER MIDNIGHT. THE SHALLOW COOL AIR WILL COME RUSHING IN
BUT MID TO UPPER TROUGH HANGS BACK TO THE WEST. THIS WILL LEAD TO
SHORTWAVE ENERGY RIDING UP ALONG THE EAST SIDE OF THE TROUGH THROUGH
THE SOUTHEAST PRODUCING WAVES OF LOW PRESSURE DEVELOPING ALONG FRONT
WHICH SHOULD REMAINED ALIGNED SW TO NE JUST TO OUR SOUTH. THEREFORE
CLOUDS AND PCP SHOULD LINGER THROUGH THURS AND POSSIBLY LONGER.
ALTHOUGH COLD AIR WILL BE LOCKED IN AT THE SFC...WARMER AIR ALOFT
SHOULD KEEP ALL PCP AS A COLD RAIN BEHIND FRONT AT THIS POINT. THE
GFS DOES SHOW MAIN SHORTWAVE SWINGING OFF THE COAST BY FRI MORNING
AS SFC HIGH BUILDS OVER THE CAROLINAS....BUT A BROAD TROUGH REMAINS
OVER THE EAST WITH MORE OF A ZONAL FLOW ALOFT BUT THERE WILL BE
POTENTIAL FOR OTHER SHORTWAVES TO MOVE THROUGH. FOR NOW WILL REMAIN
MORE OPTIMISTIC FOR FRI INTO THE WEEKEND WITH A DRIER ALTHOUGH
COOLER FORECAST.
TEMPS WILL TAKE A DIVE ONCE COLD FRONT SHIFTS SOUTH WED NIGHT WITH
850 TEMPS UP AROUND 12C WED AFTN DROPPING DOWN JUST BELOW 0C BY FRI
MORNING. THIS STRONG CAA AND POSSIBLY LINGERING CLOUDS AND PCP WILL
KEEP VERY COOL TEMPS FOR THURS AND FRI. THE LATEST GUIDANCE SHOWS
MAX TEMPS ONLY REACHING INTO THE 40S ON THURS AND NOT EVEN REACHING
40 ON FRI IN MANY PLACES. FOR NOW...WILL TREND COOLER BUT NOT GET
THAT EXTREME JUST YET AS MODELS HAVE NOT REMAINED VERY CONSISTENT
WITH THIS SYSTEM FOR LATE WEEK. HESITANT ESPECIALLY ON FRI AS
SUNSHINE WILL MAKE ITS WAY OUT AND THIS TIME OF YEAR THE SUN IS
PLAYING A BIGGER ROLE IN WARMING.
&&
.AVIATION /00Z MONDAY THROUGH SATURDAY/...
AS OF 00Z...RATHER LOW CONFIDENCE WITH THE NEXT SET OF TAFS AS FRONT
PRETTY MUCH LAYS OVER TOP OF US THROUGH THE FORECAST PERIOD.
CEILINGS WILL LIKELY BOUNCE FROM IFR TO MVFR BEFORE REMAINING
PREDOMINATELY IFR OVERNIGHT. LIGHT PRECIP ALONG THE COAST WILL MOVE
OUT OF THE REGION IN A FEW HOURS...AND THE HRRR MODEL SEEMS TO HAVE
A REASONABLE HANDLE ON IT. A WEAK TROUGH OF LOW PRESSURE WILL GIVE
US MAINLY WESTERLY WINDS OVERNIGHT...QUITE LIGHT. IFR CONDITIONS
WILL CONTINUE THROUGH THE MORNING HOURS ON MONDAY BEFORE LIFTING TO
MVFR OR BETTER. FRONT DROPS SOUTH OF THE REGION MONDAY
AFTERNOON...WITH WINDS SHIFTING TO THE NORTHEAST.
EXTENDED OUTLOOK...BECOMING VFR LATE MON. PERIODS OF MVFR/SHOWERS
TUE/WED. RAIN/IFR THUR. VFR DEVELOPING FRI.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM SUNDAY...GRADIENT CONTINUES TO WEAKEN WITH THE WEAKENING
COASTAL TROUGH NOW CLOSE TO THE COAST. WINDS AT 41013 HAVE GONE
SOUTH-SOUTHEAST BUT REMAIN AROUND 10 KT. NORTHEAST 10 TO 15 KT OVER
THE NEARSHORE WATERS WILL CONTINUE FOR THE REMAINDER OF THE
AFTERNOON WITH WINDS BECOMING LIGHT AND VARIABLE OVERNIGHT. CLOSER
TO DAYBREAK LIGHT OFFSHORE FLOW WILL DEVELOP AS WEAK HIGH CENTERED
OVER GA/SC BECOMES MORE DOMINANT. GRADIENT REMAINS WEAK AND WESTERLY
FLOW LATE IN THE PERIOD WILL CONTINUE TO RUN 10 KT OR LESS. SEAS 3
TO 5 FT THIS AFTERNOON AND EVENING WILL CONTINUE THE DOWNWARD TREND
OVERNIGHT...FALLING TO 2 TO 4 FT BY THE END OF THE PERIOD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...MARINERS SHOULD EXPECT CHANGEABLE WIND
DIRECTIONS THIS PERIOD. WINDS MON MORNING WILL BE WESTERLY...BUT
WITH THE PASSAGE OF A COLD FRONT WILL SHIFT TO N DURING THE
AFTERNOON. NE WINDS WILL BE NEAR SMALL CRAFT ADVISORY LEVELS MON
NIGHT AS A SURGE DEVELOPS IN RESPONSE TO A BUILDING WEDGE OF HIGH
PRESSURE. THE WIND DIRECTION WILL VEER TO EASTERLY DURING TUE AND
THEN SE AND S BY TUE EVE AS HIGH PRESSURE TO OUR NORTH MOVES FURTHER
OFFSHORE. WINDS OVERNIGHT TUE WILL VEER TO SW AHEAD OF A STRONG COLD
FRONT. THE STRONGEST WINDS ARE EXPECTED MON NIGHT...UP TO 20 TO 25
KT. SEAS WILL BE HIGHEST MON NIGHT INTO TUE...UP TO 4 TO 7 FT. SEAS
MAY APPROACH 6 FT TUE NIGHT...MAINLY ACROSS THE NORTHERN OFFSHORE
WATERS.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...SOUTHERLY WINDS WILL CONTINUE THROUGH WED UP
TO 15 TO 20 KTS KEEPING SEAS GENERALLY IN THE 4 TO 6 FT RANGE BUT
WILL INCREASE WED NIGHT INTO THURS AS COLD FRONT MOVES THROUGH. THE
TIGHTENED GRADIENT FLOW WILL PRODUCE WINDS UP NEAR 20 KTS AS THEY
SHIFT MORE ABRUPTLY AROUND FROM SW TO N BEHIND FRONT OVERNIGHT WED.
STRONG CAA AND TIGHTENED GRADIENT WILL KEEP SEAS UP TO 4 TO 7 FT
THURS. THE FRONT WILL LINGER TO THE SOUTH AS HIGH PRESSURE BUILDS
DOWN INTO THE WATERS FROM THE NW. THIS MAY KEEP A PROLONGED PERIOD
OF SCA CONDITIONS IN STRONG NORTHERLY WINDS THROUGH THURS INTO FRI.
WINDS WILL LIGHTEN THROUGH LATE FRI AND BECOME MORE VARIABLE INTO
THE WEEKEND AS HIGH PRESSURE SHIFTS CLOSER OVERHEAD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...III
SHORT TERM...RJD
LONG TERM...RGZ
AVIATION...43
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
307 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
A PROLONGED WET SYSTEM APPROACHES THE FORECAST AREA ON TUESDAY AND
ULTIMATELY DECIDES TO TAKE ITS TIME MOVING THROUGH THE WILD AND
WONDERFUL STATE. THE GFS IS THE MOST PROGRESSIVE OF THE BUNCH
WHILE THE EURO AND NAM ARE SIMILAR KEEPING A FIRE HOSE POINTED AT
US FOR AT LEAST 24 HOURS. THIS FORECAST MORE CLOSELY FOLLOWS THE
WETTER/SLOWER MODELS. ITS WORTH MENTIONING THAT THERE IS SOME
UNCERTAINTY IN THE LOCATION IN WHICH THE HEAVIEST RAIN FALLS...SO
THE QPF IS LIKELY BLENDED OVER A LARGER PORTION OF THE AREA THAN
WHAT WILL ACTUALLY HAPPEN.
THE MOISTURE TAP FOR THIS SYSTEM EXTENDS ALL THE WAY BACK TO THE
BAJA PENINSULA...SO REGARDLESS THIS WILL BE A RATHER JUICY SYSTEM
WITH ATMOSPHERIC RIVER POTENTIAL. A 70+ KT SWLY LLJ DEVELOPS
ENHANCING LOW LEVEL MOISTURE ADVECTION. ALL SAID AND DONE 2 INCHES
OF QPF SOUNDS REASONABLE FOR MOST PLACES...THIS COUPLED WITH
SNOWPACK MELTING IN THE WARMER TEMPERATURES THAT WE WILL
EXPERIENCE WILL CAUSE A SCENARIO WHERE FLOODING IS A LARGE
CONCERN.
ALSO OF CONCERN IS THE STRONGER WINDS IN THE MOUNTAINS...DEPENDING
ON HOW MUCH SNOW MELT OCCURS AND HOW THAWED AND SATURATED THE GROUNDS
ARE THIS COULD BE ANOTHER POTENTIAL HAZARD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH
COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING
PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS
EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR
CONTINUED COOL...BUT DRY CONDITIONS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H L L L L L L L L L L
HTS CONSISTENCY M M L L L L L L L L L L
BKW CONSISTENCY H H L L L L L L L L M M
EKN CONSISTENCY M M L L L L L L L L L L
PKB CONSISTENCY L L L L L L L L L L M H
CKB CONSISTENCY L L L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...JW
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
139 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFTERNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM
SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE
SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO
LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO
SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT
TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF
MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY.
TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF
AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR
70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO
BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN
CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED
ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON
IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE
ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS
THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS
CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS
PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM
COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE
SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH
RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF
AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING
AS IS.
AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH
THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG
THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT
STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM
WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX
ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM.
ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN
THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY
TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM
TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF
YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY
NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND
THE FRONT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
FRONTAL BOUNDARY WILL BE EAST OF THE AREA THURSDAY MORNING...WITH
COLDER AIR FILTERING INTO THE REGION...AND ANY LINGERING
PRECIPITATION CHANGING OVER TO SNOW. EXPECTING LIGHT ACCUMULATIONS
EARLY THURSDAY...PARTICULARLY ACROSS THE HIGHER TERRAIN COUNTIES.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE DEPARTING FRONT...FOR
CONTINUED COOL...BUT DRY CONDITIONS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITIONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MODERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURRING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H L L L L L L L L
HTS CONSISTENCY H H M M L L L L L L L L
BKW CONSISTENCY H H H M L L L L L L L L
EKN CONSISTENCY H H H H L L L L L L L L
PKB CONSISTENCY H H L L L L L L L L L L
CKB CONSISTENCY H H L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...30
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
135 PM EST SUN MAR 1 2015
.SYNOPSIS...
COLD FRONT CROSSES TONIGHT. HIGH PRESSURE BRINGS DRIER WEATHER
MONDAY INTO MONDAY NIGHT. ANOTHER WARM/COLD FRONT COMBO TUESDAY
INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
TEMPERATURES HAD RISEN ABOVE FREEZING THROUGHOUT MOST OF THE AREA AS
OF EARLY AFETRNOON. THEREFORE THE ADVISORIES HAVE BEEN
DROPPED...WITH THE EXCEPTION ON POCAHONTAS COUNTY IN THE CAD. THIS
EXPIRES AT 7 PM BY WHICH TIME THE LAST OF THE COLD AIR SHOULD
FINALLY BE ERRADICATED.
THE WIDESPREAD PRECIPITATION WILL BE CUT OFF FOR THE MOST PART
TONIGHT AS A COLD FRONT CROSSES THE AREA. MODELS DO SUGGEST ONE
LAST W-E DAGGER OF PRECIPITATION BEHIND THE FRONT TONIGHT...AS ONE
LAST TRAILING UPPER LEVEL S/W TROUGH MOVES THROUGH. CONSIDERED
EXTENDING THE PERRY-MORGAN ADVISORY FOR THIS BUT THERE SHOULD NOT BE
A FREEZING RAIN THREAT AND ADDITIONAL SNOW AMOUNTS SHOULD BE AN INCH
OR LESS.
OTHERWISE UPSLOPE FLOW SUPPORTS SNOW SHOWERS IN THE MOUNTAINS
OVERNIGHT INTO MON WITH UP TO AN INCH OR SO THERE. LOW LEVEL
MOISTURE WILL KEEP PLENTY OF CLOUDS AROUND MON...A MORNING CU
PROCESS IN THE MORNING...MIXING UP INTO A STRATOCU DECK THAT SHOULD
START TO BREAK UP IN THE AFTERNOON. IT SHOULD CLEAR FURTHER AS HIGH
PRESSURE BUILDS INTO THE AREA AT THE END.
USED HRRR AND THEN NAM/MET FOR TEMPS...A BIT SHARPER BAROCLINIC ZONE
TONIGHT AND A BIT LOWER ON HIGHS MON COMPARED WITH PREVIOUS WITH
TEMPERATURES NOT RISING MUCH UNTIL AFTER 15Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
ATTENTION TURNS TO WHAT HAS BECOME A WELL ADVERTISED WET SYSTEM
SLATED FOR MID WEEK. LIKE HPC...STILL PREFER THE LESS PROGRESSIVE
SCENARIO GIVEN POSITIVE TILT TO UPPER TROF HANGING BACK...OWING TO
LESS PROGRESSION OF SFC FLOW AS THE FLOW ALOFT REMAINS PARALLEL TO
SFC FRONT. PRECIP WILL BREAK OUT ALONG DEVELOPING WARM FRONT
TUESDAY...WITH BEST CHANCES ACROSS SE OH. THERE MAY BE A VERY BRIEF
MIX AT THE ONSET...BUT THIS IS PRIMARILY A RAIN MAKER ON TUESDAY.
TRIED TO KEEP HIGH POPS CONFINED TO SE OH AND N WV AS REMAINDER OF
AREA REMAINS IN THE MORE SHOWERY WARM SECTOR. LLJ INCREASES TO NEAR
70 KTS TUESDAY NIGHT OUT OF SW WITH THE OVERALL FLOW TRYING TO
BECOME PARALLEL TO THE SFC COLD FRONT AS IT BEGINS TO SLOW DOWN
CONSIDERABLY ON APPROACH. COPIOUS AMOUNTS OF MOISTURE WILL BE POOLED
ALONG FRONTAL BOUNDARY...WITH PWATS SURGING TO NEAR 1.5 INCHES ON
IMPRESSIVE THETA E ADVECTION. THE FIRST AREA OF CONCERN WILL BE
ACROSS SE OH TUESDAY NIGHT...AND SLOW SHIFTING SE ON WEDNESDAY AS
THE FRONT SAGS SE. IT IS AT THIS POINT MODELS DIVERGE WITH GFS
CONTINUING TO BE ON THE PROGRESSIVE SIDE. THE NEW ECMWF IS NOT AS
PROGRESSIVE BUT DOES ENTRAIN MODIFIED ARCTIC AIR INTO THIS SYSTEM
COME WEDNESDAY NIGHT. AGAIN...STILL PREFER THE LESS PROGRESSIVE
SCENARIO ATTM...WHICH KEEPS THE RAIN GOING ALONG AND E OF THE OH
RIVER ON WEDNESDAY. KEPT THE HEAVY RAIN WORDING IN WX GRIDS. QPF
AMOUNTS LOOK TO AVG AROUND 2 INCHES AREAWIDE. WILL KEEP HWO WORDING
AS IS.
AS MENTIONED...THINGS GET TRICKY HEADING INTO WEDNESDAY NIGHT WITH
THE LESS PROGRESSIVE ECMWF WITH SECONDARY SURFACE WAVE FORMING ALONG
THE BOUNDARY AMID COLD AIR INTRUSION. THIS BRINGS A CONCERN THAT
STARTS WITH HEAVY RAIN AND FLOODING TO THE OTHER END OF THE SPECTRUM
WITH WINTRY WX. CONFIDENCE IS LOW REGARDING EXTENT OF ANY WINTRY WX
ON THE BACK SIDE OF THIS AND THE MAGNITUDE OF SUCH ATTM.
ON A SIDE NOTE...TEMPS WILL BE WARMING TO MORE SEASONAL LEVELS IN
THE WARM SECTOR WITH LOW TO MID 50S LOOKING LIKE A GOOD BET ON BY
TUESDAY AFTERNOON IN THE LOWLANDS AMID BREEZY S FLOW. THESE WARM
TEMPS HANG ON TUESDAY NIGHT FOR A RATHER MILD NIGHT FOR THIS TIME OF
YEAR. DEPENDING ON HOW THINGS PLAY OUT ON WEDNESDAY AND WEDNESDAY
NIGHT WILL DETERMINE JUST HOW RAPID A FALL OF TEMPS TO EXPECT BEHIND
THE FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM STARTS OUT RATHER SOAKING WET. COLD FRONT WILL SLOWLY BE
PROGRESSING EASTWARD ACROSS THE CWA AT THE BEGINNING OF THE
PERIOD...WITH A WAVE OF LOW PRESSURE RIDING ALONG THE FRONT FROM
SOUTHWEST TO NORTHEAST...ENHANCING PRECIPITATION AS IT DOES SO.
STILL LOOKING LIKE HEAVY RAIN ON WEDNESDAY...IN THE MOIST
ATMOSPHERE...ALONG WITH SOME RATHER GUSTY WINDS EXPECTED TUESDAY
NIGHT INTO EARLY WEDNESDAY...WITH THE STRONG SOUTHWESTERLY FLOW AND
TIGHT PRESSURE GRADIENT. RAISED WIND GUSTS AND ADDED HEAVY RAIN
WORDING IN THE TUESDAY NIGHT THROUGH WEDNESDAY PERIOD.
FRONT WILL BEGIN TO PUSH EAST THURSDAY OR THURSDAY NIGHT...WITH
COLDER AIR RUSHING IN...AND A CHANGE OVER TO SNOW AREA WIDE. ITS
POSSIBLE THERE COULD BE SOME LIGHT ACCUMULATIONS...BUT WITH THE
WET...WARM GROUND...AT THIS POINT NOT SURE HOW MUCH WILL ACTUALLY BE
ABLE TO ACCUMULATE.
COLD HIGH PRESSURE WILL BUILD IN BEHIND THE EXITING FRONT FOR FRIDAY
INTO THE REMAINDER OF THE EXTENDED. WITH TEMPERATURES DIPPING BELOW
NORMAL ONCE AGAIN.
WILL CONTINUE TO HIGHLIGHT WATER ISSUES FOR NEXT WEEK IN THE HWO.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
WIDESPREAD MVFR IN MAINLY RAIN ASSOCIATED WITH WARM ADVECTION S FLOW
OVER THE AREA...WITH TEMPERATURES ABOVE FREEZING AT ALL 6
TERMINALS. VSBYS WILL IMPROVE OVERNIGHT TONIGHT AS DRIER AIR
ARRIVES IN THE WAKE OF A COLD FRONT THAT CUTS OFF THE WARM
ADVECTION. THIS FRONT ROLLS THROUGH W TO E BETWEEN 3 AND 6Z. MVFR
OR WORSE VSBY WILL PERSIST IN THE MOUNTAINS OVERNIGHT AS RAIN
SHOWERS THERE CHANGE OVER TO SNOW SHOWERS BEHIND THE COLD FRONT.
CIGS TONIGHT WILL DROP TO CLOSE TO 1KFT...SO IFR CIGS ARE POSSIBLE.
MON WILL BRING IMPROVING CONDITONS WITH MOUNTAIN SNOW SHOWERS ENDING
BY LATE MORNING...AND MORNING CU THAT WILL EVOLVE INTO AN AFTERNOON
STRATOCU DECK. THESE CLOUD HEIGHTS WILL RISE...BUT MAY REMAIN BELOW
3KFT...BUT START TO BREAK UP IN THE LOWLANDS IN THE AFTERNOON...AS
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NW.
LIGHT S SFC FLOW WILL BECOME LIGHT NW BEHIND THE FRONT OVERNIGHT.
MODERATE SW FLOW ALOFT THIS AFTERNOON INTO THIS EVENING...WILL
BECOME MOERATE W OVERNIGHT TONIGHT AND THEN MODERATE NW FOR MON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: GUIDANCE SHOWS WIDESPREAD IFR TONIGHT. THERE
IS THE CHANCE FOR THIS OCCURING TONIGHT BEFORE THE COLD FRONT
ARRIVES. THIS IS THE REASON FOR THE NUMEROUS INSTANCES OF L IN THE
TABLE BELOW.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EST 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00
CRW CONSISTENCY H H H H L L L L L L L L
HTS CONSISTENCY H H M M L L L L L L L L
BKW CONSISTENCY H H H M L L L L L L L L
EKN CONSISTENCY H H H H L L L L L L L L
PKB CONSISTENCY H H L L L L L L L L L L
CKB CONSISTENCY H H L L L L L L L L L L
AFTER 18Z MONDAY...
IFR POSSIBLE IN RAIN SHOWERS TUESDAY INTO WEDNESDAY...AND PERHAPS
SNOW AT THE END WEDNESDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ046.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/SL/30
NEAR TERM...TRM
SHORT TERM...30
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
346 PM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA THIS EVENING. THIS PAIR OF WEATHER FEATURES WILL
BRING PERIODS OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED
PRECIPITATION TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY INTO
THIS EVENING. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS
TO REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY...BRINGING MAINLY RAIN TO THE AREA. COLDER TEMPERATURES
WILL FOLLOW FOR THE LATER PART OF THE WEEK.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
DID ADJUST THE AREA OF FREEZING RAIN SOME...TO FIT IN WITH THE
CURRENT OBS.
EARLIER DISCUSSION BELOW.
BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE
WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH
CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW
O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW
FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER
ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF
INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL
CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15"
OF ICE ON TOP IN THOSE AREAS.
OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF
VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR
EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE
ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER
CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON
AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH
HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES
FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED
TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD
AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF
NEARS.
12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG
THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT
HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY
LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN
THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP
OF THE 2-4" OF SNOW ACCUM.
ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES
CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF
THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322
CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN
TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT
APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE
AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE
COULD SEE SOME SPOT AMOUNTS COME IN HIGHER.
TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE
UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID
30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS RESPECTIVELY.
WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST PLACES THROUGH TODAY.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH MONDAY NIGHT/...
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
DID NOT MAKE ANY LARGE CHANGES TO MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
MAIN CHANGE WAS TO ADJUST POPS SOME TUE INTO TUE NIGHT.
THINK MAIN TYPE OF PCPN WILL BE RAIN TUE NIGHT INTO WED. DID
PUT SMALL AMTS OF .01 ICE ACROSS THE AREA...GIVEN THAT OBJECT
TEMPS WILL STILL LIKELY BE COLD. TEMPERATURES TUE NIGHT MAY
DROP A LITTLE...BEFORE COMING BACK UP LATE.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
FOR WED...TOOK SNOW SHOWERS OUT OF THE NW. TIGHT THICKNESS PATTERN
ACROSS THE AREA...SUPPORT A LARGE TEMPERATURE GRADIENT FROM NW PA
TO SE PA. THERE COULD BE A FEW SHOW SHOWERS ACROSS THE FAR
NW...BUT IT LOOKS LIKE MAINLY NW OF OUR AREA. LEFT POPS UP...THINK
FRONT WILL BE SLOW TO MOVE OUT.
A TREND TOWARD COLDER WEATHER AGAIN LATER IN THE WEEK...GIVEN
SPLIT FLOW.
PUSH OF ARCTIC AIR WILL BRING TEMPS AND POPS BACK WELL BELOW
NORMAL FOR LATE THURSDAY INTO FRIDAY. THE ONLY GOOD THING SEEMS TO
BE EACH ARCTIC SHOT IS A LITTLE LESS POTENT THAN THE LAST AS WE
LEAVE THE RECORD COLD OF FEBRUARY BEHIND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA
THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX
TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ
WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW
PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL
HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA
COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM
HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
FRI...MAINLY VFR.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT/MARTIN
NEAR TERM...DEVOIR/LAMBERT/MARTIN
SHORT TERM...DEVOIR/LAMBERT/MARTIN
LONG TERM...LA CORTE/LAMBERT/MARTIN
AVIATION...DEVOIR/LAMBERT/MARTIN
CLIMATE...LAMBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
129 PM EST SUN MAR 1 2015
.SYNOPSIS...
WEAK LOW PRESSURE AND A DISTURBANCE AT UPPER LEVELS OF THE
ATMOSPHERE WILL TRACK NORTHEAST UP THE OHIO VALLEY AND CROSS
PENNSYLVANIA TODAY. THIS PAIR OF WEATHER FEATURES WILL BRING PERIODS
OF LIGHT TO BRIEFLY MODERATE SNOW...THEN SOME MIXED PRECIPITATION
TO SOUTH-CENTRAL PA AND THE LOWER SUSQ VALLEY LATE TODAY AND
TONIGHT. HIGH PRESSURE WILL BRING FAIR AND COLD CONDITIONS TO
REGION MONDAY AND MONDAY NIGHT. A STRONGER AREA OF LOW PRESSURE
WILL LIKELY TRACK WEST OF PENNSYLVANIA LATE TUESDAY AND EARLY
WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BRIGHT BANDING AND ELEVATED CCS SHOWING THE PRECIP TRANSITION ZONE
WELL AS IT TRANSLATES NORTH OF THE MD BORDER INTO THE SOUTH
CENTRAL MOUNTAINS AND FAR LOWER SUSQ RIVER VALLEY. 3" OF NEW SNOW
O.G. NEAR GREENCASTLE FROM A TRUSTED WEATHER SPOTTER AND NOW
FREEZING RAIN OCCURRING AT 27F. SLEET HAD BRIEFLY MIXED IN EARLIER
ACROSS SOUTHERN YORK. A GENERAL 2-4" IS EXPECTED SOUTH OF
INTERSTATE 80 AND EAST OF ROUTE 99...WITH THE ADDITIONAL
CHANGEOVER TO ICE ACROSS SOUTHERN PORTIONS OF THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ RIVER VALLEY ADDING ANOTHER .1 TO .15" OF
ICE ON TOP IN THOSE AREAS.
OVERALL SCENARIO PLAYING OUT WITH WITH PERIODS OF SNOW (OF
VARYING INTENSITY) CONTINUING TO INCREASE IN AREAL COVERAGE THIS
AFTERNOON FROM SOUTHWEST TO NORTHEAST. STRONG VERTICAL SHEAR
EVIDENT ACROSS THE REGION WITH 150+ KT 250 MB JET SLICING ENE
ACROSS THE NORTHERN OHIO VALLEY AND EASTERN GLAKS. BOUNDARY LAYER
CONVERGENCE AND FORCING IS BEST ACROSS SOUTHERN PA THIS AFTERNOON
AND EVENING...IN VICINITY OF 850 MB JET FEATURES...FIRST OF WHICH
HAS SPAWNED A FEW HOURS OF MODERATE TO LOCALLY HEAVY PRECIP RATES
FROM NORTHERN MARYLAND INTO MY SOUTHEAST COUNTIES. THIS IS PROGGED
TO EXIT EASTWARD BY LATE AFTERNOON/EVENING BEFORE A MORE BROAD
AREA OF BOUNDARY LAYER CONVERGENCE DEVELOPS AS THE UPPER TROF
NEARS.
12Z RAP HANDLED THE ONGOING CHANGEOVER QUITE WELL FOR AREAS ALONG
THE MD BORDER...AND EXPECT MDT TO BE CHANGING OVER IN THE NEXT
HOUR OR TWO...STARTING WITH A MIXTURE OF SLEET AND THEN MAINLY
LIGHT FREEZING RAIN AFTERWARD WITH AROUND 0.10 INCH QPF. WILL
CONTINUE TO RIDE WITH A BLEND OF CURRENT AND UPCOMING HIGH RES
GUIDANCE FOR ICE ACROSS OUR SRN ZONES...UNLESS WE SEE REASON TO
SIGNIFICANTLY DEVIATE.
WE WILL CONTINUE TO HOLD OFF ON ANY UPGRADES TO WINTER STORM/ICE
STORM WARNINGS AT THIS TIME...AS AMOUNTS ARE EXPECTED TO REMAIN IN
THE .1 TO .15" RANGE OVERALL...WITH SOME APPROACHING .20" ON TOP
OF THE 2-4" OF SNOW ACCUM.
ELSEWHERE...GOOD CONSISTENCY OF PAST SEVERAL MODEL/ENSEMBLE CYCLES
CONTINUES THIS AFTERNOON WITH RESPECT TO PTYPE...WITH BULK OF
THIS WINTRY EVENT FALLING AS SNOW TO THE NORTH OF THE RT22/322
CORRIDOR IN CENTRAL PENN. AMOUNTS AND DISTRIBUTION HAVE BEEN
TRICKY GIVEN THE LACK OF FORCING FARTHER NORTH...BUT IN GENERAL IT
APPEARS THAT 2-4" WILL BE COMMON FOR MOST...WHILE BETTER UPSLOPE
AND MOISTURE TRANSPORT INTO THE WEST CENTRAL MOUNTAINS AND LAUREL
HIGHLANDS PRODUCE MAX AMOUNTS THERE...GENERALLY UP TO 6" BUT WE
COULD SEE SOME SPOT AMOUNTS COME IN HIGHER.
TEMPS WILL WILL CONTINUE TO SLOWLY RISE TO A LATE DAY HIGH IN THE
UPPER 20S ACROSS THE CENTRAL AND NORTHERN MTNS...AND LOWER TO MID
30S ACROSS THE LOWER SUSQ VALLEY AND LAUREL HIGHLANDS
RESPECTIVELY. WINDS WILL BE SOUTH TO SW AT 5-8 KTS IN MOST
PLACES THROUGH TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
PRECIP LOOKS TO TAPER OFF IN ALL AREAS DURING THE LATE EVENING
THROUGH VERY EARLY MORNING HOURS OF MONDAY.
LOW TEMPS TONIGHT /UNDER PLENTY OF LINGERING AND MORE
SHALLOW...WARMER LOWER CLOUDS/ WILL RANGE FROM NEAR 20 DEG IN THE
NORTH TO 30F IN ACROSS THE SOUTH.
BLUSTERY AND COLDER CONDITIONS WILL MAKE A RETURN ON MONDAY AS
SYSTEM NUMBER ONE SLIDES OFF TO OUR EAST. OTHER THAN THE USUAL
POST FRONTAL SNOWS SHOWERS...FAVORING WESTERN HIGHER
ELEVATIONS...CONDITIONS WILL BE GRADUALLY IMPROVING OVERALL
THROUGHOUT THE DAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE AND ITS FAIR WEATHER AND LIGHT WIND WILL BE SHORT
LIVED MONDAY NIGHT INTO TUESDAY WHEN THE NEXT IN THE SERIES OF
STORM SYSTEMS IS SLATED TO ENTER THE LOCAL WEATHER SCENE. THIS ONE
PROMISES MORE OF A MESSY OUTCOME AS IT SHOULD TRACK WELL TO OUR
NW...MEANING WARM AIR EVENTUALLY INVADING THE REGION...WITH A SNOW
TO SLEET/FREEZING RAIN AND EVEN RAIN SCENARIO.
SNOW AMOUNTS DO NOT LOOK TO BE THE BIGGEST PART OF THE MIDWEEK
STORM AS WE ARE PROGGED TO WARM ALOFT RATHER QUICKLY. WITH A DEEP
SNOW PACK AND A LOT OF COLD AIR TO DISPLACE...WE WILL LIKELY SEE
A PERIOD OF ICING BEFORE WARM AIR EVENTUALLY CHANGES EVERYTHING TO
RAIN TUESDAY NIGHT INTO WEDNESDAY.
RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS WITH THE PASSAGE OF
THE TRAILING COLD FRONT EARLY WEDNESDAY.
EARLIER MODEL RUNS SUGGESTED LATER WEDNESDAY INTO THURSDAY THERE
COULD BE A RETURN OF SNOW TO SRN PA ASSOCIATED WITH A FLAT SRN
STREAM WAVE...BUT LATEST OPERATIONAL ECMWF/GFS NOW KEEP THE
SURFACE WAVE SUPPRESSED MAINLY SOUTH OF THE REGION..HINTING THAT
ONLY FAR SERN AREAS WILL BE AT RISK FOR A PERIOD OF OVER RUNNING
SNOW. THE 06Z GEFS IS A LITTLE MORE GENEROUS WITH THE POPS SO IT`S
NOT OUT OF THE QUESTION THAT SOMETHING WILL YET HAPPEN AS MODELS
TRY AND RESOLVE SMALL SCALE FEATURES DROPPING OUT OF CENTRAL
CANADA INTO THE EASTERN US LONG WAVE. TOO FAR OFF TO LEAN ONE WAY
OR ANOTHER FOR A SOLUTION.
BEHIND THE MID WEEK SYSTEM...ANOTHER PUSH OF ARCTIC AIR WILL
BRING TEMPS AND POPS BACK WELL BELOW NORMAL FOR LATE THURSDAY INTO
FRIDAY. THE ONLY GOOD THING SEEMS TO BE EACH ARCTIC SHOT IS A
LITTLE LESS POTENT THAN THE LAST AS WE LEAVE THE RECORD COLD OF
FEBRUARY BEHIND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
EXPECT BEST RADAR RETURNS TO OCCUR ACROSS CENTRAL AND SOUTHERN PA
THIS AFTERNOON AND EVENING IN THE BEST LOW LEVEL CONVERGENCE. MIX
TRANSITION TO ICE ACROSS SOUTH CENTRAL MOUNTAINS AND LOWER SUSQ
WILL LIFT NORTH OF KMDT MID TO LATE AFTERNOON AS WEAK LOW
PRESSURE FROM THE OHIO VALLEY TRACKS EASTWARD INTO THE LAUREL
HIGHLANDS AND SECONDARY WEAK LOW PRES FORMS NEAR THE DELMARVA
COAST. ACROSS THE NRN MTNS OF PA VSBYS SHOULD AVERAGE NEARLY 1SM
HIGHER IN THE LIGHT SNOW.
GENERALLY IFR TO LIFR CONDITIONS IN SNOW EXPECTED TO CONTINUE ALL
DAY AND INTO THIS EVENING. CIGS REMAIN ABOVE 1500FT AT 1530Z
ACROSS MOST CENTRAL AND ERN PA AIRFIELDS...BUT HAVE DROPPED OFF TO
BELOW 1KFT AGL ACROSS THE WRN MTNS...AND WILL CONTINUE TO
GRADUALLY DROP IN ALL AREAS AS THE DAY WEARS ON. STILL THE THREAT
OF SOME FZRA MIXING IN FOR THE SOUTHERN TIER COUNTIES LATER THIS
AFT AND THIS EVENING.
VSBYS WILL IMPROVE OVERNIGHT AS SNOW COMES TO AN END...BUT CIGS
WILL REMAIN LOW KEEPING MAINLY IFR CONDITIONS GOING BEFORE LIFTING
TO MVFR IN THE CENTRAL AND EAST LATE.
CONDITIONS SHOULD CONTINUE TO SLOWLY IMPROVE ON MONDAY...BUT
EXPECT RESTRICTIONS TO LINGER IN THE WESTERN AND NORTHERN HIGHER
TERRAIN ON COLD NORTHWEST WINDS AND TYPICAL OROGRAPHIC SNOW
SHOWERS.
BRIEF RESPITE LATER MONDAY INTO EARLY TUESDAY...BEFORE THE NEXT
SYSTEM PUSHES ANOTHER ROUND OF PRECIPITATION AND REDUCED FLYING
CONDITIONS INTO THE AREA LATER TUESDAY AND WEDNESDAY.
OUTLOOK...
MON...CIG/VIS REDUCTIONS MAINLY AM...THEN IMPROVING CONDITIONS.
TUE...VFR AM. MIXED PRECIP WITH CIG/VIS REDUCTIONS POSSIBLE LATE.
WED...CIG/VIS REDUCTIONS CONTINUE IN WINTRY MIX/RAIN.
THU...SLOWLY IMPROVING CONDITIONS...LINGERING MVFR NW AND SE.
&&
.CLIMATE...
THE BOOKS HAVE CLOSED AND WE NOW HAVE /AND MADE IT THROUGH/ THE
COLDEST FEBRUARY ON RECORD.
MONTHLY MEAN TEMPERATURES WERE...IPT 18.1...MDT 20.9.
THE PREVIOUS RECORDS FOR THE COLDEST FEBRUARY...IPT 19.3...MDT
21.4 BOTH SET IN 1934.
THIS FEBRUARY RANKED AS THE THIRD COLDEST CALENDAR MONTH EVER AT
IPT...AND FOURTH COLDEST EVER AT MDT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST MONDAY FOR PAZ019-027-
028-037-041-042-045-046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR PAZ004>006-
010>012-017-018-024-033.
WINTER WEATHER ADVISORY UNTIL 11 PM EST THIS EVENING FOR
PAZ025-026-034>036.
&&
$$
SYNOPSIS...DEVOIR/LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...DEVOIR/LAMBERT
LONG TERM...LA CORTE/LAMBERT
AVIATION...DEVOIR/LAMBERT
CLIMATE...
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1054 AM MST SUN MAR 1 2015
.UPDATE...
ISSUED AT 1055 AM MST SUN MAR 1 2015
NO CHANGES TO THE FORECAST TODAY. MAIN FOCUS REMAINS ON THE STORM
SYSTEM WHICH WILL MOVE ACROSS THE AREA TOMORROW AND TOMORROW
NIGHT. MODELS NOT IN GREAT AGREEMENT WITH WHERE THE HEAVIEST SNOW
WILL FALL...BUT THERE IS GENERAL CONSENSUS POINTS TO SOUTH
CENTRAL WYOMING. CURRENT WATER VAPOR AND RADAR OVER THE SOUTHWEST
CONUS SHOWING MOISTURE STREAMING NORTHEASTWARD FROM ARIZONA. SEEMS
REASONABLE THERE WILL BE WIDESPREAD SNOW ACROSS THE ENTIRE AREA BY
MONDAY NIGHT AS AN UPPER LEVEL DISTURBANCE MOVES FROM THE CENTRAL
ROCKIES INTO THE NORTHERN PLAINS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 400 AM MST SUN MAR 1 2015
LATEST GOES WATER VAPOR IMAGERY SHOWED THE SPLIT CLOSED UPPER LOW
SLOWLY SINKING SOUTHEAST ALONG THE CENTRAL CA COAST. THE BASE OF
THE NORTHERN STREAM TROUGH WAS MOVING EAST ACROSS THE DAKOTAS. A
DEFORMATION ZONE STRETCHED NORTHEAST TO SOUTHWEST FROM WESTERN NE
ACROSS NORTHERN CO. NARROW BAND OF UPPER LIFT COMBINED WITH MOISTURE
AND WEAK UPSLOPE RESULTED IN AN AREA OF LIGHT SNOW OVER PORTIONS
OF SOUTHEAST WY AND WESTERN NE. HRRR MODEL PROGS THIS AREA TO WEAKEN
AS IT MOVES FURTHER EAST THROUGH DAYBREAK. TEMPERATURES WERE IN THE
SINGLE DIGITS AND TEENS WITH LIGHT WINDS.
FORECAST CONCERNS DURING THE SHORT TERM WILL FOCUS ON THE DEVELOPING
WINTER STORM AND ITS IMPACTS ON OUR AREA...PARTICULARLY FROM LATE
TONIGHT THROUGH TUESDAY. CLOSED UPPER LOW NEAR SOUTHERN CA COAST
GRADUALLY OPENS UP AND EJECTS NORTHEAST AS ANOTHER SHORTWAVE DROPS
SOUTH ALONG THE CA COAST DURING THE NEXT 24 TO 48 HOURS. THE MODEL
CONSENSUS PROGS A LOW PRESSURE SYSTEM TO FORM NEAR THE FOUR CORNERS
REGION AND TRACK NORTHEAST ACROSS COLORADO. LIGHT SNOW REDEVELOPS
LATER TODAY OVER THE SOUTHERN MOUNTAINS AND BECOMES MORE WIDESPREAD
AND HEAVIER LATE TONIGHT INTO MONDAY. THE GFS IS SLIGHTLY DEEPER
AND FASTER THAN THE ECMWF WITH REGARDS TO THE SURFACE LOW AND ITS
MOTION. THEY ARE SIMILAR WITH THE EASTWARD TRACK OF THE LOW INTO
THE CENTRAL PLAINS EARLY TUESDAY MORNING. THEY ALSO AGREE WITH THE
ARCTIC COLD FRONTAL PASSAGE DURING THIS TIME PERIOD. WINDS SHIFT
TO NORTHERLY AND BECOME GUSTY TUESDAY. SNOW WILL BE WIDESPREAD
OVER THE CWA MONDAY NIGHT AND TUESDAY. THE COMBINATION OF FALLING
AND BLOWING SNOW WILL RESULT IN HAZARDOUS TRAVEL WEST OF THE
LARAMIE RANGE...ESPECIALLY MONDAY THROUGH TUESDAY. LATEST WPC
GUIDANCE PROGS 1-2 FT OF SNOW FOR THE SNOWY/SIERRA MADRE RANGES
WITH UP TO A FOOT FOR THE NEARBY VALLEYS. ISSUED A WINTER STORM
WATCH FOR WY ZONES 111-114 LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR THE POTENTIAL OF HEAVY SNOW. FURTHER NORTH AND EAST...WE`RE
LOOKING AT ADVISORY ACCUMULATIONS...GENERALLY 4-8 INCHES. THE
SOUTHERN LARAMIE RANGE COULD GET CLOSE TO A FOOT AS WELL. THE NEXT
SHIFT MAY UPGRADE AND/OR EXTEND THE WINTER HEADLINES AFTER LOOKING
AT THE 12Z/18Z MODEL GUIDANCE.
HIGHS TODAY WILL BE SIMILAR TO SATURDAY WITH MOSTLY UPPER TEENS TO
UPPER 20S. LOWS TONIGHT AND MONDAY NIGHT WILL AVERAGE IN THE TEENS.
MONDAY WILL BE MILDER WITH SOUTHWESTERLY WINDS. EXPECT HIGHS IN THE
30S TO AROUND 40. TEMPERATURES TUESDAY WILL NOT RISE MUCH FROM THE
EARLY MORNING LOWS...AND WILL BE FALLING THROUGH THE DAY IN THE
WAKE OF THE COLD FRONTAL PASSAGE.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 330 AM MST SUN MAR 1 2015
THE MAIN CHALLENGE IN THE EXTENDED WILL BE TEMPERATURE TRENDS AS WE
STILL ANTICIPATE A BAND OF NEW SNOWPACK SOMEWHERE IN THE CWA. GFS/EC
BOTH SHOW A SECONDARY SHORTWAVE DIVING ACROSS WY BETWEEN 00Z AND 12Z
WED. MODEST PVA SHOULD BE ENOUGH FOR SNOW SHOWERS TO LINGER INTO WED
MORNING OR PERHAPS EARLY AFTERNOON. MEDIUM RANGE 700-300 MILLIBAR RH
PROGS SUGGEST A DRYING COLUMN BY THIS TIME...SO EXPECT LESS THAN AN
INCH OF ADDITIONAL ACCUMULATION OVER THE LOWER ELEVATIONS AFTER 00Z
WED. TEMPERATURES WILL BE TRICKY ON TUE NIGHT AS CLOUDS WILL PREVENT
SIGNIFICANT RADIATIONAL COOLING. HOWEVER...MODELS AGREE WITH STRONG
LOW LEVEL COLD ADVECTION PUSHING H7 TEMPS AS LOW AS -20 DEG C BY 12Z
WED PER THE EURO. GIVEN AN AIR MASS THIS COLD...CONFIDENCE IS FAIRLY
HIGH THAT MANY AREAS WILL BE BELOW ZERO FOR LOWS. DID NOT STRAY TOO
FAR AWAY FROM GUIDANCE THOUGH. COOLEST TEMPERATURES ON WED SHOULD BE
FOUND OVER THE MOST SUBSTANTIAL SNOWPACK. GUIDANCE SUGGESTS THE BEST
CHANCE FOR LOW-ELEVATION SIGNIFICANT SNOWFALL EARLY IN THE WEEK WILL
BE WEST OF THE LARAMIE RANGE...SO UNDERCUT MOS BY SEVERAL DEGREES IN
THOSE AREAS. KEPT HIGHS BELOW GUIDANCE ACROSS THE BOARD WITH MUCH OF
THE AREA LIKELY TO RECEIVE ACCUMULATING SNOW IN THE SHORT TERM.
IMPROVING TEMPERATURES LATER IN THE WEEK AS UPPER-LEVEL RIDGING AND
LOW LEVEL DOWNSLOPE RETURN TO THE REGION. A BACK DOOR COLD FRONT IS
PROGGED TO SINK SOUTHWARD ON FRI AFTERNOON...POSSIBLY HAVING A SMALL
IMPACT ON HIGHS WITH COLD ADVECTION ALOFT. CANNOT RULE OUT ISOLATED
RAIN OR SNOW SHOWERS ON FRI NIGHT OR SAT MORNING WITH THE ARRIVAL OF
BETTER MID LEVEL SUPPORT. HOWEVER...KEPT THE FORECAST DRY FOR NOW AS
THIS SYSTEM LOOKS TO BE A BIT MOISTURE STARVED. STILL EXPECT A WINDY
PERIOD FROM WED NIGHT THROUGH FRI OVER THE WIND PRONE AREAS. THE GFS
HAS BEEN CONSISTENT WITH A STRONG H85 CAG-CPR GRADIENT IN EXCESS OF
60 METERS AND 45 TO 50 KT FLOW OVER ARL AND BRX AT H75 THROUGH MUCH
OF THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH MONDAY MORNING)
SNOW SHOWERS WILL CONTINUE TO DIMINISH THIS MORNING WITH GENERALLY
MVFR CONDITIONS PREVAILING ALONG I80...AND VFR FURTHER NORTH
ACROSS WESTERN NEBRASKA. A WARM FRONT WILL SLOWLY MOVE NORTHWARD
ACROSS THE AREA TONIGHT...BRINGING ANOTHER ROUND OF SNOW TO AREAS
ALONG I80. LOW MVFR TO IFR CIGS/VSBYS ARE LIKELY AFTER 06Z TONIGHT.
WINDS WILL GENERALLY BE LIGHT THROUGH THE TAF PERIOD BUT WILL
INCREASE OUT OF THE SOUTH LATE TONIGHT AND INTO EARLY MONDAY
MORNING.
&&
.FIRE WEATHER...
ISSUED AT 321 AM MST SUN MAR 1 2015
A WEAK UPPER LEVEL DISTURBANCE WILL PRODUCE LIGHT SNOW EARLY THIS
MORNING OVER FAR SOUTHEAST WYOMING AND SOUTHERN NEBRASKA PANHANDLE.
A LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL TROUGH WILL APPROACH
FROM THE SOUTHWEST TONIGHT AND MONDAY...AND MOVE ACROSS THE CENTRAL
ROCKIES MONDAY NIGHT AND TUESDAY. SNOW WILL DEVELOP TONIGHT ACROSS
SOUTH CENTRAL WYOMING AND BECOME MORE WIDESPREAD MONDAY AND MONDAY
NIGHT. THE SNOW WILL BE HEAVY AT TIMES...ESPECIALLY OVER THE HIGHER
TERRAIN. THE SNOW WILL TAPER OFF TUESDAY NIGHT. A ARCTIC COLD FRONT
WILL PLUNGE SOUTH THROUGH THE DISTRICT MONDAY NIGHT. BITTERLY COLD
TEMPERATURES AND WIND CHILLS WILL PREVAIL TUESDAY THROUGH WEDNESDAY
BEFORE GRADUALLY MODERATING TEMPERATURES LATE IN THE WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY NIGHT
FOR WYZ111>114.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...MAJ
LONG TERM...CLH
AVIATION...TJT
FIRE WEATHER...MAJ