929
FXUS62 KRAH 040605
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
205 AM EDT THU SEP 4 2025
SYNOPSIS
WEAK HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL SHIFT OFFSHORE
THROUGH EARLY THURSDAY, AS A COLD FRONT APPROACHES FROM THE
NORTHWEST. THIS FRONT WILL STALL OUT AND HOLD TO OUR NORTHWEST
THROUGH SATURDAY, ALLOWING WARMER AIR TO FLOW INTO THE REGION. THE
FRONT WILL FINALLY PUSH INTO THE AREA SUNDAY, WITH COOLER HIGH
PRESSURE THEN RETURNING FOR SUNDAY NIGHT THROUGH WEDNESDAY.
NEAR TERM /TODAY THROUGH TONIGHT/
AS OF 205 AM THURSDAY...
A COLD FRONT CURRENTLY EXTENDS FROM A SURFACE LOW NEAR HUDSON BAY
SOUTH ACROSS LAKE HURON INTO OHIO AND MISSOURI. THE FRONT WILL SLIDE
EAST TODAY, ALTHOUGH IT WILL NOT CROSS CENTRAL NORTH CAROLINA,
REMAINING TO THE NORTH AND WEST. HOWEVER, THERE IS A CHANCE THAT
SOME SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE TRIAD. FOR NOW,
HAVE KEPT THE TRIANGLE FORECAST DRY, BUT THERE ARE SOME MEMBERS IN
THE 00Z HREF INDICATING THAT SHOWERS/STORMS COULD MAKE THEIR WAY AS
FAR EAST AS I-95. 30+ KT VALUES OF EFFECTIVE WIND SHEAR SHOULD
REMAIN WEST OF THE TRIAD, BUT WITH MUCAPE REACHING UP TO 1000 J/KG,
CANNOT RULE OUT AN ISOLATED STRONG TO SEVERE THUNDERSTORM IN THE
TRIAD WHERE THE SPC HAS ISSUED A MARGINAL RISK (LEVEL 1 OF 5) FOR
SEVERE THUNDERSTORMS, WITH DAMAGING WIND GUSTS THE PRIMARY THREAT.
THE CHANCE OF PRECIPITATION SHOULD END AROUND SUNSET. IN ADVANCE OF
THE FRONT, SOUTHWESTERLY WINDS WILL BRING AN END TO THE STRETCH OF
COOL TEMPERATURES, BRINGING HIGHS INTO THE 80S ACROSS THE AREA.
OVERNIGHT LOWS WILL BE IN THE 60S.
SHORT TERM /FRIDAY AND FRIDAY NIGHT/
AS OF 205 AM THURSDAY...
TODAY'S FRONT WILL REMAIN NORTHWEST OF THE AREA ON FRIDAY, WITH A
DRY FORECAST LOCALLY. HOWEVER, WITH THE WIND REMAINING OUT OF THE
SOUTH, TEMPERATURES WILL CONTINUE TO BE ON THE INCREASE. THE
FORECAST FOR RDU ON FRIDAY IS 91 DEGREES - 90 DEGREES HAS NOT BEEN
REACHED THERE SINCE AUGUST 17. ELSEWHERE, HIGHS WILL RANGE FROM THE
UPPER 80S TO THE MID 90S. FRIDAY NIGHT WILL LIKELY BE THE WARMEST
OUT OF THE NEXT SEVEN NIGHTS, WITH VALUES RANGING FROM THE MID 60S
TO THE LOWER 70S.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
AS OF 130 AM THURSDAY...
* MUCH ABOVE NORMAL TEMPS CONTINUE SATURDAY, THEN COOLING BACK OFF
STARTING SUNDAY.
* SCATTERED SHOWERS AND STORMS POSSIBLE OVER THE WEEKEND.
SAT-SAT NIGHT: THE APPROACHING COLD FRONT WILL STAY TO OUR NW
THROUGH SAT, AS WILL THE AXIS OF THE LONGWAVE MID LEVEL TROUGH
EXTENDING FROM A LOW OVER E HUDSON BAY SSW THROUGH THE MIDWEST AND
GREAT LAKES. MULTIPLE SHORTWAVE TROUGHS SWINGING THROUGH THE MEAN
TROUGH BASE WILL EVENTUALLY HELP NUDGE THE FRONT E OVER THE CENTRAL
AND SRN APPALACHIANS SAT NIGHT, BUT WE'LL OVERALL REMAIN IN THE
PREFRONTAL WARM SECTOR WITH DECENT INSOLATION DURING THE DAY,
PUSHING PROJECTED LOW LEVEL THICKNESSES UP TO 10-15 M ABOVE NORMAL.
GFS AND NBM FORECAST SOUNDINGS INDICATE FAIRLY DEEP SURFACE BASED
MIXING AND WARM MID LEVELS, SO DESPITE DAYTIME HEATING, THE
PROBABILITY OF SBCAPE OVER 1000 J/KG IS MOSTLY UNDER 30% AND HINGES
A LOT ON HOW MUCH PREFRONTAL DEWPOINT RECOVERY CAN BE ACHIEVED. DEEP
LAYER BULK SHEAR WILL REMAIN MODEST, JUST AROUND 20 KTS, AND PWS
WILL TREND TO SLIGHTLY ABOVE NORMAL SAT BUT MOSTLY JUST OVER THE NW
CWA. THUS WILL STILL INDICATE SCATTERED CONVECTION MOVING INTO THE
NW SAT AFTERNOON AND SHIFTING ACROSS MAINLY NORTHERN SECTIONS INTO
THE EVENING, DWINDLING AFTER MIDNIGHT. EXPECT HIGHS SAT FROM AROUND
90 N TO THE LOW 90S S, WITH ISOLATED MID 90S SE. SLIGHT COOLING IS
POSSIBLE NW SAT NIGHT, ALTHOUGH THE MOST ABRUPT PUSH OF COOLER AIR
INTO CENTRAL NC WILL LIKELY NOT OCCUR UNTIL SUN. LOWS FROM THE LOW-
MID 60S NW TO UPPER 60S/NEAR 70 SE.
SUN-WED: A PROMINENT SHORTWAVE TROUGH OVER N IL/LK MICHIGAN EARLY
SUN IS EXPECTED TO SWING THROUGH IN/OH AND INTO THE NORTHEAST STATES
SUN/SUN NIGHT, HELPING TO NUDGE THE MEAN LONGWAVE TROUGH EASTWARD
AND PUSH THE SURFACE COLD FRONT SE THROUGH MUCH OF OUR AREA BY MON
MORNING (ALTHOUGH SOME MODELS HAVE THE FRONT SLOWING AND RESIDING
LONGER ACROSS OUR FAR SE). BUT THE LONGWAVE TROUGH ITSELF WILL BE
BROADENING AND DEAMPLIFYING GRADUALLY, AND THE SLOWING AND DAMPENING
OF THE SOUTHERN PORTIONS OF THE LONGWAVE TROUGH S OF THE MASON-DIXON
LINE AND REDUCED MID LEVEL SPEEDS STILL BRING ABOUT SOME UNCERTAINTY
AS TO HOW FAST THE FRONT WILL PROGRESS INTO THE CWA SUN, ESPECIALLY
WITH THE WEAKENING MID LEVEL FLOW STILL WITH A COMPONENT PARALLEL TO
THE SURFACE FRONT. WILL MAINTAIN CHANCE POPS SUN INTO SUN EVENING,
HIGHEST FROM THE TRIANGLE S AND E, WITH HIGHS FROM THE MID 70S NW TO
THE LOW 80S SE. THE COOL POST-FRONTAL SURFACE HIGH CENTERED OVER THE
N PLAINS AND MIDWEST SUN MORNING WILL SHIFT E THROUGH THE S GREAT
LAKES AND OHIO VALLEY THROUGH MON, THEN CROSS THE E GREAT LAKES/ST
LAWRENCE VALLEY/NEW ENGLAND THROUGH TUE AND THE CANADIAN MARITIMES
BY WED, ALL THE WHILE NOSING SE THEN S AND SSW THROUGH CENTRAL NC AS
THE FRONTAL ZONE SETTLES NEAR THE CAROLINA COAST AND ACROSS N FL.
MULTI-MODEL LOW LEVEL THICKNESSES ARE FORECAST TO BE QUITE LOW, 25
TO 35 M BELOW NORMAL, SUGGESTING HIGHS MOSTLY IN THE 70S (PERHAPS
NEAR 80 SE) MON-WED, DESPITE DECENT SUNSHINE, ALTHOUGH AREAS E OF
HIGHWAY 1 SHOULD SEE GREATER HIGH CLOUDS GIVEN THE PROXIMITY OF THE
SURFACE FRONTAL ZONE AND THE POSITION OF THE UPPER LEVEL JET STREAK
AXIS OVERHEAD FROM SW TO NE. NIGHTLY LOWS IN THE 50S TO LOWER 60S
ARE EXPECTED. ISOLATED TO SCATTERED LATE-DAY SHOWERS AND A FEW
STORMS WILL BE POSSIBLE IN OUR FAR SE EACH DAY MON-WED, BUT
OTHERWISE MUCH OF THE AREA WILL STAY DRY. -GIH
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 205 AM THURSDAY...
TAF PERIOD: RDU/FAY/RWI ARE EXPECTED TO REMAIN VFR THROUGH THE NEXT
24 HOURS, WITH GUSTS UP TO 20 KT POSSIBLE (WITH THE 06Z TAF PACKAGE,
HAVE REMOVED THE GUST POTENTIAL FROM FAY). HOWEVER, AT INT/GSO,
THERE WILL BE TWO DIFFERENT PERIODS THAT COULD RESULT IN
RESTRICTIONS. THE FIRST WILL BE AROUND SUNRISE, WHERE THERE IS THE
POTENTIAL FOR FOG TO DEVELOP ACROSS THE WESTERN HALF OF THE STATE
AND MOVE EAST INTO THE TRIAD. WITH THESE SITES LIKELY ON THE EASTERN
FRINGE OF ANY FOG THAT DOES DEVELOP, BROUGHT GSO'S VISIBILITY UP TO
5 MILES TO SHOW THE UNCERTAINTY THERE COMPARED TO INT. THE SECOND
PERIOD THAT COULD RESULT IN RESTRICTIONS WOULD BE WITH A LINE OF
SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON. THE THUNDERSTORMS
COULD BRING VISIBILITY RESTRICTIONS ALONG WITH GUSTY WINDS.
OUTLOOK: CANNOT RULE OUT THE POTENTIAL FOR FOG AGAIN FRIDAY MORNING
AT INT/GSO. AS A FRONT SLOWLY MOVES ACROSS THE REGION SATURDAY AND
SUNDAY, THIS COULD BRING RESTRICTIONS IN SHOWERS AND THUNDERSTORMS.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...GREEN
SHORT TERM...GREEN
LONG TERM...HARTFIELD
AVIATION...GREEN
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