025
FXUS62 KRAH 141120
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
720 AM EDT TUE OCT 14 2025
SYNOPSIS
LOW PRESSURE WILL MEANDER OFF THE MIDDLE ATLANTIC COAST TODAY, WHILE
HIGH PRESSURE WILL BUILD FROM THE OH AND TN VALLEYS TO THE SOUTHERN
APPALACHIANS. A DRY, BACKDOOR COLD FRONT WILL MOVE SOUTH ACROSS THE
REGION WEDNESDAY EVENING, FOLLOWED BY CANADIAN HIGH PRESSURE THAT
WILL BUILD ACROSS AND OFFSHORE THE MIDDLE ATLANTIC THURSDAY THROUGH
SATURDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 355 AM TUESDAY...
THE MODELS INDICATE A SHORTWAVE PERTURBATION, NOW EVIDENT OVER ERN
PA IN GOES-E WV DATA, WILL DIG SEWD AND ACROSS AND OFFSHORE THE
MIDDLE ATLANTIC COAST THIS MORNING AND BECOME ABSORBED BY A CLOSED
MID/UPR-LEVEL LOW CYCLONE CENTERED ABOUT 250 MILES EAST OF THE
DELMARVA. UPSTREAM, A SUB-TROPICAL HIGH CENTERED AT 591 DAM AT 500
MB OVER ERN TX WILL STRENGTHEN ANOTHER FEW DECAMETERS AND PROBABLY
SHATTER DAILY RECORD 500 MB HEIGHTS FROM THE SRN PLAINS TO THE MID
MS VALLEY TODAY, AS STANDARDIZED 500 MB HEIGHT ANOMALIES THERE REACH
3 SIGMA. A RIDGE EXTENDING NEWD FROM THE HIGH WILL PROGRESS ACROSS
THE MIDDLE ATLANTIC TODAY AND CAROLINAS TONIGHT. ASSOCIATED RISING
HEIGHTS AND SUBSIDENCE WILL CAUSE AN ALREADY-PRONOUNCED SUBSIDENCE
INVERSION, EVIDENT AROUND 10 THOUSAND FT ON 00Z-OBSERVED RAOBS OVER
THE REGION, TO STRENGTHEN AND LOWER WITH TIME.
AT THE SURFACE, MULTI-CENTERED LOW PRESSURE, ANCHORED THIS MORNING
BY A ~1006 MB LOW ABOUT 275 MILES EAST OF HSE, WILL WOBBLE GENERALLY
EWD AND AWAY FROM THE MIDDLE ATLANTIC COAST THROUGH 12Z WED, WHILE
DEEPENING 10-12 MILLIBARS.
MOISTURE IN GENERALLY NLY FLOW TRAPPED BENEATH THE LOWERING
SUBSIDENCE INVERSION, BETWEEN THE OFFSHORE CYCLONE AND STRENGTHENING
SUB-TROPICAL RIDGE, WILL MAINTAIN MULTI-LAYERED CEILINGS OVER THE
ERN TWO THIRDS OF CNTL NC THROUGH EARLY TO MID-AFTERNOON (ALL BUT
THE SRN AND NW PIEDMONT), FOLLOWED BY EAST TO WEST CLEARING MID-
AFTERNOON THROUGH EVENING. THOSE CEILINGS WILL BE ACCOMPANIED BY AN
AREA OF LIGHT RAIN AND DRIZZLE, NOW EVIDENT IN REGIONAL RADAR DATA
WRAPPING CYCLONICALLY IN REGIONAL RADAR DATA FROM NJ SWWD THROUGH
CNTL-ERN MD AND NRN VA, THEN SWD THROUGH ERN VA AND MOST RECENTLY
NERN NC. THE AREA OF RAIN APPEARS TO BE FORCED PRIMARILY BY
ISENTROPIC UPGLIDE/MOISTURE TRANSPORT CENTERED IN THE 295-300 K (925-
850 MB) LAYER; AND THE MODELS SUGGEST THIS UPGLIDE WILL CONTINUE SWD
INTO THE NRN AND CNTL COASTAL PLAIN OF NC THIS MORNING, WHERE A
CHANCE OF LIGHT RAIN AND DRIZZLE WILL REMAIN IN THE FORECAST THROUGH
~15Z.
HIGH TEMPERATURES WILL AGAIN FOLLOW A SIMILAR DISTRIBUTION AS THE
CLOUDS/CEILINGS AND RANGE FROM GENERALLY PERSISTENCE MID/UPR 70S IN
THE SRN AND WRN PIEDMONT TO MID/UPR 60S IN THE COASTAL PLAIN,
FOLLOWED BY LOW TEMPERATURES IN THE 50S.
SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/
AS OF 400 AM TUESDAY...
THE MID-LEVEL SHORTWAVE AND ASSOCIATED SURFACE LOW WILL PUSH ENE
FARTHER INTO THE ATLANTIC ON WEDNESDAY AND WEDNESDAY NIGHT.
MEANWHILE MID-LEVEL RIDGING WILL BUILD EAST FROM THE SOUTHERN PLAINS
TO THE LOWER MS VALLEY, WITH A CANADIAN SURFACE HIGH SLOWLY DRIFTING
SE OVER THE UPPER GREAT LAKES. NW FLOW ALOFT BETWEEN THESE TWO
FEATURES WILL RESULT IN DRY WEATHER AND SUNNY SKIES ACROSS CENTRAL
NC ON WEDNESDAY. HIGH TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL, IN
THE MID-TO-UPPER-70S. MEANWHILE A BACKDOOR COLD FRONT WILL DROP
SOUTH THROUGH THE MID-ATLANTIC, REACHING CENTRAL NC ON WEDNESDAY
NIGHT, BUT IT WILL BE DRY. THIS WILL KEEP NORTHERLY WINDS ELEVATED
OVERNIGHT, AND SOME BRIEF GUSTINESS IS POSSIBLE WITH THE FRONTAL
PASSAGE. LOWS WILL BE IN THE UPPER-40S TO LOWER-50S.
LONG TERM /THURSDAY THROUGH MONDAY/
AS OF 400 AM TUESDAY...
THURSDAY THROUGH SATURDAY WILL BE DRY AND MOSTLY SUNNY ACROSS
CENTRAL NC UNDER THE CONTINUED INFLUENCE OF THE CANADIAN SURFACE
HIGH AND NW FLOW ALOFT BETWEEN RIDGING TO OUR WEST AND TROUGHING TO
OUR EAST. THE MID/UPPER RIDGE AXIS WILL MOVE EAST TO THE TN VALLEY
AND GREAT LAKES BY FRIDAY, THEN BEGIN TO FLATTEN ON SATURDAY AS IT
MOVES ACROSS THE NORTHEAST US AND MID-ATLANTIC. THIS IS IN RESPONSE
TO A CLOSED MID/UPPER LOW THAT TRACKS FROM SOUTH-CENTRAL CANADA TO
THE UPPER GREAT LAKES THIS WEEKEND, WITH ASSOCIATED DEEP TROUGHING
OVER THE EASTERN US. WHILE THE TYPICAL TIMING DIFFERENCES EXIST IN
THE MODELS THIS FAR OUT, A COLD FRONT TO THE SOUTH OF THE LOW LOOKS
TO PASS THROUGH CENTRAL NC ON SUNDAY NIGHT. SOME SHOWERS ARE
POSSIBLE WITH ITS PASSAGE, BUT WITH ITS PROGRESSIVE MOVEMENT, THE
BEST UPPER FORCING TO OUR NORTH, AND MEAGER INSTABILITY (A FEW
HUNDRED J/KG OF CAPE OR LESS), RAINFALL AMOUNTS DON'T LOOK TOO
IMPRESSIVE. GFS/ECM ENSEMBLE MEAN QPF CONTINUES TO BE ONLY IN THE
TENTH TO QUARTER INCH RANGE, AND EVEN THE 90TH PERCENTILE IS ONLY
AROUND HALF AN INCH. THIS LIKELY WON'T BE ENOUGH TO MAKE A
SIGNIFICANT DENT IN THE ONGOING ABNORMALLY DRY AND DROUGHT
CONDITIONS ACROSS OUR REGION. MONDAY SHOULD TURN CLEAR AND DRY
BEHIND THE FRONT.
AS FOR TEMPERATURES, THEY WILL TURN MUCH COOLER ON THURSDAY AND
FRIDAY BEHIND THE BACKDOOR FRONT, WITH HIGHS RANGING FROM MID-60S NE
TO LOWER-70S SW. DEW POINTS WILL ONLY BE IN THE 30S AND 40S.
THURSDAY NIGHT WILL BE THE COOLEST OF THE PERIOD OWING TO GOOD
RADIATIONAL COOLING CONDITIONS FROM THE SURFACE HIGH WHICH WILL BE
CENTERED OVER THE NORTHERN APPALACHIANS. WITH LOW-LEVEL THICKNESSES
IN THE 1340-1350 M RANGE, FORECAST LOWS ARE IN THE UPPER-30S TO
LOWER-40S, AND ISOLATED FROST CAN'T BE RULED OUT IN THE COOLEST
OUTLYING SPOTS OF THE PIEDMONT. AS THE SURFACE HIGH MOVES OFF THE
COAST OF THE CAROLINAS AND WE GET SW FLOW AHEAD OF THE NEXT COLD
FRONT, CONDITIONS WILL TURN WARMER ON SATURDAY AND SUNDAY WITH HIGHS
IN THE MID-TO-UPPER-70S. LOWS WILL BE IN THE MID-40S TO LOWER-50S ON
FRIDAY NIGHT AND MID-TO-UPPER-50S ON SATURDAY NIGHT. MONDAY WILL
TURN COOLER AGAIN BEHIND THE FRONT WITH HIGHS IN THE UPPER-60S TO
LOWER-70S.
AVIATION /11Z TUESDAY THROUGH SATURDAY/
AS OF 720 AM TUESDAY...
MOIST, NLY FLOW AND ASSOCIATED IFR-MVFR CEILINGS OVER ERN VA/NC,
LOWEST NEAREST THE COAST, WILL SPREAD SSWWD AND ACROSS RDU AND FAY
BY AROUND 15Z. THOSE CEILINGS, ONES WHICH MAY BE ACCOMPANIED BY
PATCHY LIGHT RAIN OR DRIZZLE AT RWI THIS MORNING, WILL THEN
GRADUALLY LIFT AND SCATTER/CLEAR TO VFR FROM WEST TO EAST THROUGH
THE DAY, FIRST AT RDU AND LAST AT RWI AND FAY. VFR CONDITIONS ARE
MEANWHILE EXPECTED TO PERSIST AT GSO AND INT. NLY SURFACE WINDS WILL
STRENGTHEN AND BECOME GUSTY INTO THE TEENS TO AROUND 20 KTS,
STRONGEST AT RWI, WITH DAYTIME HEATING AROUND 14Z. SURFACE WINDS
WILL CONTINUE TO GUST, AT LEAST OCCASIONALLY SO, THROUGH SUNSET.
OUTLOOK: STRATOCUMULUS BASED AROUND 2500-3500 FT AGL WILL PROBABLY
LINGER FOR MOST OF THE NIGHT OVER ERN NC; AND SOME MAY REDEVELOP
WSWWD TO NEAR AND ESPECIALLY JUST EAST OF RWI AND RDU WED MORNING. A
PROLONGED PERIOD OF VFR CONDITIONS WILL OTHERWISE BE LIKELY
THROUGHOUT CNTL NC THE REST OF THE WEEK.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...DANCO
LONG TERM...DANCO
AVIATION...MWS
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