547
FXUS62 KRAH 170604
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
105 AM EST MON FEB 17 2025
SYNOPSIS
CONTINENTAL POLAR HIGH PRESSURE WILL BUILD ACROSS THE MIDDLE
ATLANTIC AND CAROLINAS THROUGH TUESDAY NIGHT. LOW PRESSURE WILL THEN
TRACK ACROSS THE GULF AND SOUTH ATLANTIC COASTS WEDNESDAY AND
WEDNESDAY NIGHT. ARCTIC HIGH PRESSURE WILL FOLLOW AND MIGRATE FROM
THE NORTHERN PLAINS TO THE MIDDLE ATLANTIC, WHILE WEAKENING AND
MODIFYING, THROUGH NEXT WEEKEND.
NEAR TERM /TONIGHT/
AS OF 950 PM SUNDAY...
*SEASONABLY CHILLY, AND CONTINUED BLUSTERY THROUGH THE EARLY MORNING
HOURS MON.
IN THE WAKE OF A VIGOROUS SHORTWAVE TROUGH NOW PIVOTING ACROSS THE
NORTHEAST, AND A MINOR TRAILING ONE THAT WILL PIVOT ACROSS AND
OFFSHORE THE SRN MIDDLE ATLANTIC TONIGHT, QUASI-ZONAL FLOW AND
RISING HEIGHTS WILL DEVELOP FROM THE SRN AND CNTL PLAINS TO THE SRN
MIDDLE ATLANTIC THROUGH EARLY MON. THOSE RISING HEIGHTS ALOFT WILL
BE ACCOMPANIED BY CONTINUED, STRONG LOW/MID-TROPOSPHERIC COLD AIR
ADVECTION OVER THE MIDDLE AND SOUTH ATLANTIC. DEEP SUBSIDENCE WILL
RESULT OVER CNTL NC.
AT THE SURFACE, THE POLAR FRONT HAS CROSSED ALL BUT THE SRN AND CNTL
OUTER BANKS IN NC AS OF 02Z, WITH FOLLOWING PRESSURE RISES AND HIGH
PRESSURE THAT WILL CONTINUE TO BUILD FROM THE CNTL PLAINS AND MID MS
VALLEY SEWD AND ACROSS THE SOUTHEAST TONIGHT. WHILE CAA AND MIXING
WILL PROBABLY PERSIST THROUGHOUT THE NIGHT, POINT FORECAST SOUNDINGS
AND MOMENTUM TRANSFER POTENTIAL INDICATE THE STRONGEST MIXING AND
ONGOING GUSTS BETWEEN 25-35 MPH LATE THIS EVENING WILL GRADUALLY
LESSEN AFTER 05-06Z. PREVIOUSLY FORECAST LOW TEMPERATURES GENERALLY
WITHIN A FEW DEGREES EITHER SIDE OF 30 F REMAIN ON TRACK.
LOOKING AHEAD TO THE MID-WEEK WINTER STORM POTENTIAL: THE MAIN
MID/UPR-LEVEL FORCING FEATURE FOR THE WINTER STORM POTENTIAL OVER
CNTL NC WILL BE FROM AN ELONGATED CYCLONE COMPRISED OF MULTIPLE
SHORTWAVE PERTURBATIONS NOW EXTENDING FROM JUST OFFSHORE THE PACIFIC
NORTHWEST COAST NWWD INTO THE GULF OF ALASKA, AND UNDERCUTTING A
BLOCKING HIGH OVER BRITISH COLUMBIA AND SRN YUKON. THESE FEATURES,
ONES WHICH MODEL GUIDANCE TO VARYING DEGREES INDICATE MAY PHASE WITH
A POLAR VORTEX OVER THE LWR GREAT LAKES AND MIDDLE ATLANTIC BY WED
NIGHT-THU, WILL NOT BE FULLY SAMPLED BY THE NOAM RAOB NETWORK FROM
THE CNTL ROCKIES TO THE PACIFIC NORTHWEST UNTIL 00Z TUE. ANY SHORT
TERM MODEL TRENDS BEFORE THEN, SUCH AS THE SWD SHIFT IN SUNDAY'S 12Z
GUIDANCE SUITE AS NOTED IN WPC'S EXTENDED FORECAST DISCUSSION
(PMDEPD), SHOULD NOT YET BE CONSIDERED A "MOST LIKELY" SOLUTION. AS
THESE FEATURES ARE BETTER SAMPLED, MODEL TRENDS AND SOLUTIONS BY
THIS TIME MON EVENING SHOULD INCREASE FORECAST CONFIDENCE IN THE
EVENTUAL WINTRY IMPACTS AND FORECAST DETAILS FOR CNTL NC.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/
AS OF 309 PM SUNDAY...
MON/MON NIGHT: BROAD, FAST ZONAL STEERING FLOW WILL PERSIST, AS VAST
SURFACE HIGH PRESSURE CENTERED OVER SASKATCHEWAN SPREADS SE INTO NC.
DRY AND STABLE AIR THROUGH A DEEP LAYER WILL KEEP SKIES FAIR TO
MOSTLY SUNNY MON, ALTHOUGH BY MON NIGHT WELL START TO SEE HIGH
CLOUDS SPREADING IN FROM THE WYOMING BASIN/N ROCKIES AND CENTRAL
PLAINS, ESP ACROSS OUR N, AND SKIES HERE SHOULD TREND TO PARTLY
CLOUDY. LOW LEVEL THICKNESSES WILL BE AROUND 35 M BELOW NORMAL, THUS
EXPECT BELOW NORMAL HIGHS IN THE MID 40S TO LOW 50S, FOLLOWED BY
LOWS IN THE MID 20S TO AROUND 30. -GIH
TUE/TUE NIGHT: THE MID-LEVEL FLOW TUESDAY WILL START OFF ZONAL
BEFORE A WEAKLY AMPLIFIED RIDGE DEVELOPS OVER CENTRAL NC TUESDAY
EVENING. A STRONG HIGH OVER THE UPPER MIDWEST WILL EXTEND COOL NELY
FLOW ACROSS OUR AREA. HIGH CLOUDS AND CHILLY TEMPS IN THE UPPER 40S
TO LOWER 50S IS EXPECTED WITH DRY CONDITIONS. THE MID-LEVEL RIDGE
WILL DE-AMPLIFY AS A STRONG TROUGH DIGS INTO THE UPPER MIDWEST
OVERNIGHT. ANY PRECIPITATION SHOULD GENERALLY HOLD OFF THROUGH 12Z
WEDNESDAY. OVERNIGHT LOWS IN THE UPPER 20S TO LOWER TO MID 30S IS
EXPECTED.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/
AS OF 100 AM MONDAY...
THE ARCTIC HIGH WILL BUILD DOWN INTO THE CENTRAL PLAINS AND MID-MS
VALLEY ON THURSDAY NIGHT AND FRIDAY, THEN THE TN VALLEY ON SATURDAY
AND THE EAST COAST ON SUNDAY. THIS WILL BRING A VERY COLD AND DRY
AIR MASS WHICH GRADUALLY MODIFIES THROUGH THE END OF THE PERIOD.
TEMPERATURES, JUST HOW COLD IT GETS, WILL NOT BE DETERMINED UNTIL
THE POTENTIAL FOR THE WINTER STORM IS OVER. WE WILL KEEP THE
PREVIOUS FORECAST OF THURSDAY NIGHT LOWS IN THE TEENS TO LOWER 20S.
FRIDAY'S FORECAST HIGHS ONLY IN THE UPPER 30S TO LOWER 40S, THEN
40S ON SATURDAY AND SUNDAY.
AVIATION /06Z MONDAY THROUGH FRIDAY/
AS OF 100 AM MONDAY...
VFR CONDITIONS ARE EXPECTED THROUGH 06Z/TUE.
OUTLOOK: POTENTIAL LOW PRESSURE MAY BRING A CHANCE OF WINTRY
PRECIPITATION AND FLIGHT RESTRICTIONS TO CNTL NC LATE TUE NIGHT
THROUGH WED. OTHERWISE, VFR.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...HARTFIELD/LUCHETTI
LONG TERM...BADGETT
AVIATION...BADGETT/MWS
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