958
FXUS62 KRAH 221037
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
635 AM EDT TUE SEP 22 2026
WHAT HAS CHANGED
* ADJUSTED SKY AND POP FORECAST TO ACCOUNT FOR A FEW SHOWERS IN THE
TRIAD AND TO REFLECT THE SLOWER ARRIVAL OF THE LOW OVERCAST IN
WESTERN AND SOUTHWESTERN AREAS.
KEY MESSAGES
AS OF 320 AM TUESDAY...
1) SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED
TODAY AND TONIGHT WITH LOCALLY HEAVY RAIN POSSIBLE AND A FEW STRONG
STORMS.
2) COLD AIR DAMMING WILL BRING MUCH BELOW NORMAL TEMPERATURES DURING
MID TO LATE WEEK.
DISCUSSION
AS OF 320 AM TUESDAY...
KEY MESSAGE 1... SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT WITH LOCALLY HEAVY RAIN POSSIBLE AND A
FEW STRONG STORMS.
A STRONG COLD FRONT ACROSS VA EARLY THIS MORNING WILL SHIFT SOUTH
AND MOVE ACROSS CENTRAL NC TONIGHT. THE AIRMASS AHEAD OF THE FRONT
ACROSS CENTRAL NC THIS AFTERNOON WILL BE VERY MOIST WITH PWAT VALUES
OF 1.75 TO 2.0 INCHES WHICH IS AROUND 125% OF NORMAL. THE AIRMASS
WILL ALSO BE WEAKLY TO MODERATELY UNSTABLE WITH MLCAPE VALUES OF
AROUND 500 TO 1500 J/KG. THE LOW AND MID LEVEL FLOW WILL BE WEAK
RESULTING IN WEAK SHEAR AND LIMITED STORM ORGANIZATION. THIS WILL
ALSO SUPPORT SLOW STORM MOTION WITH MESSY STORM STRUCTURES AND
COLLIDING OUTFLOWS. A MARGINAL RISK OF SEVERE STORMS HAS BEEN
HIGHLIGHTED, MAINLY ACROSS THE WESTERN PIEDMONT WHERE DOWNBURST
WINDS ARE THE GREATEST THREAT. A BIGGER RISK MAY BE THE POTENTIAL
FOR EXCESSIVE RAIN AND LOCALIZED FLOODING THIS AFTERNOON AND EARLY
EVENING. CAMS SUGGEST A MINIMUM OF CONVECTION DURING THE MORNING
HOURS WITH STORM FIRING TOWARD MIDDAY ACROSS THE NORTHERN AND
CENTRAL COASTAL PLAIN, THEN BUILDING WEST ACROSS THE U.S. 64 AND I-
40 REGIONS DURING THE EARLY AND MID AFTERNOON WITH THE STRONGEST
STORMS SHIFTING SOUTH DURING THE LATE AFTERNOON AND EARLY EVENING
HOURS. THE DEEP CONVECTION WILL WANE BY THE MID EVENING HOURS WITH
SCATTERED SHOWERS TRANSITIONING TO AREAS OF RAIN OVERNIGHT, FOCUSED
ACROSS THE WESTERN PIEDMONT. FOR THE 24 HOUR PERIOD ENDING AT 12Z
WEDNESDAY, THE HEAVIEST RAIN IS APT TO FALL ACROSS THE COASTAL PLAIN
AND THE EASTERN PIEDMONT WITH AMOUNTS OF 1.0 TO 1.5 INCHES AND
GENERAL AMOUNTS OF 0.5 TO 1.0 INCHES ELSEWHERE.
HIGHS TODAY WILL RANGE FROM AROUND 80, PERHAPS THE UPPER 70S NEAR
THE VA BORDER AND THE TRIAD, TO THE LOWER 80S IN THE TRIANGLE THE
MID 80S ACROSS THE SOUTH. LOWS TONIGHT WILL RANGE NEAR 60 ALONG THE
VA BORDER AND TRIAD AND THE MID TO UPPER 60S IN THE SANDHILLS AND
SOUTHERN COASTAL PLAIN. -BLAES
KEY MESSAGE 2... COLD AIR DAMMING WILL BRING MUCH BELOW NORMAL
TEMPERATURES DURING MID TO LATE WEEK.
THE SURFACE FRONT WILL PUSH TO THE S AND SE OF THE FORECAST AREA
LATER TODAY, SETTING THE STAGE FOR DEVELOPMENT OF A ROBUST,
CLASSICAL COLD AIR DAMMING EVENT THAT WILL DOMINATE OUR WEATHER
THROUGH THE END OF THE WEEK. AS PART OF THE REX BLOCK SETTING UP
OVER THE UPPER MIDWEST AND MANITOBA/ONTARIO LATER TODAY, MID LEVEL
ENERGY WILL UNDERCUT THE BLOCKING HIGH, CROSSING IN AND THE OHIO
VALLEY WED BEFORE DEEPENING TO A SLOW-MOVING CLOSED LOW THAT WILL
WOBBLE OVER THE MID ATLANTIC REGION AND NORTHEAST INTO THE WEEKEND.
THIS PATTERN WILL KEEP THE SURFACE FRONTAL ZONE PINNED TO OUR S AND
SE, WITH STEADY ADVECTION INTO CENTRAL NC OF COOL AND LOW-DEWPOINT
SURFACE AIR FROM A STRONG AND ANCHORED SURFACE HIGH CENTERED THIS
MORNING OVER W QUEBEC. THIS SURFACE HIGH WILL WEAKEN AS IT SLOWLY
RETROGRADES TO THE WSW LATE THU INTO FRI, DRIFTING INTO THE N GREAT
LAKES AND S ONTARIO IN RESPONSE TO WHAT IS EXPECTED TO BE STRONG
COASTAL CYCLOGENESIS JUST OFF THE MID ATLANTIC AND NORTHEAST COAST
BY FRI/SAT. BUT THE CIRCULATION AROUND THIS COASTAL LOW ALONE SHOULD
HELP MAINTAIN THE LOW LEVEL CAA AND WEDGE REGIME INTO FRI, DESPITE
THE LIKELIHOOD OF FURTHER DRYING ALOFT AND INCREASED INSOLATION
POTENTIALLY ERODING MUCH OF THE CAD STRATUS THROUGHOUT THE DAY.
THE RESULT WILL BE MULTIPLE DAYS OF BELOW NORMAL HIGH TEMPS,
INCLUDING HIGHS FROM THE TRIANGLE TO THE N AND W IN THE 60S TO
AROUND 70 EACH DAY WED THROUGH FRI. DAYTIME TEMPS WILL BE FURTHER
HELD DOWN BY COPIOUS CLOUD COVER AND AREAS OF OVERRUNNING RAIN,
DRIVEN IN LARGE PART BY MOIST ISENTROPIC UPGLIDE FOCUSED AT 295K-
305K FROM WED MORNING THROUGH THU NIGHT, ALONG WITH A SERIES OF MID
LEVEL PERTURBATIONS SPREADING IN FROM THE WEST. IN ADDITION TO THE
COOL DAYS, WE'RE LIKELY TO SEE A FEW NIGHTTIME LOWS IN THE 40S NEAR
THE VA BORDER THU NIGHT THROUGH SAT NIGHT. RAIN CHANCES WILL DWINDLE
THU NIGHT AND REMAIN LOW FRI THROUGH THE WEEKEND, WITH DIMINISHING
FORCING FOR ASCENT AND PLUMMETING PW. BUT THE POTENTIAL FOR A BAGGY
MID LEVEL TROUGH OR SHEAR AXIS HOLDING ACROSS THE REGION ALONG WITH
A PERSISTENT LOW LEVEL FLOW FROM THE N OR NNW AROUND THE COASTAL
LOW, POTENTIALLY SPREADING CLOUD COVER INTO THE AREA ESPECIALLY IN
THE NE, SHOULD RESULT IN HIGHS REMAINING AT LEAST A CATEGORY BELOW
NORMAL SAT/SUN. GIVEN HOW HOT THIS SEPTEMBER HAS BEEN SO FAR, HAVING
SEVERAL DAYS OF BELOW TO MUCH-BELOW NORMAL TEMPS WILL BE A WELCOME
RESPITE FOR MANY.
AVIATION /11Z TUESDAY THROUGH SATURDAY/
AS OF 635 AM TUESDAY...
THE SOUTHWARD SURGE OF LOW STRATUS AND AREAS OF FOG FROM THE
NORTHEAST HAS BEEN A LITTLE SLOWER THAN EXPECTED BUT IFR AND LIFT
CIGS HAVE NOW SPREAD INTO KRWI, KGSB, KJNX, KSCR. THE LOW CIGS AND
VSBYS HAVE BEEN SLOWER TO ARRIVE IN THE TRIAD ESPECIALLY AT KINT AND
KGSO BUT LIFR CIGS HAVE SPREAD INTO KBUY AND KEXX.
STILL EXPECT THE LOW STRATUS AND FOG WITH IFR RESTRICTIONS OR WORSE
WILL SPREAD ACROSS JUST ABOUT ALL OF CENTRAL NC BY AROUND OR JUST
AFTER DAYBREAK.
LOW STRATUS WILL LIKELY PERSIST FOR MOST OR ALL OF THE 24 HOUR TAF
PERIOD AT KINT AND KGSO. WHILE CIGS MAY NUDGE UPWARD THIS AFTERNOON,
OVERALL AVIATION CONDITIONS WILL REMAIN POOR. ADDITIONAL SHOWERS ARE
EXPECTED THIS AFTERNOON WITH A TRANSITION TO LIGHT RAIN TONIGHT. AT
KRDU AND KRWI, IFR/LIFR RESTRICTIONS WILL PERSIST THROUGH MUCH OF
THE MORNING WITH SOME IMPROVEMENT THIS AFTERNOON AS RESTRICTIONS
IMPROVE TO MVFR WITH PERSISTENT STRATUS AND PERHAPS A FEW PERIODS OF
MVFR CONDITIONS AT KRWI THIS AFTERNOON. ADDITIONAL SHOWERS AND
PERHAPS A FEW THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND EARLY
EVENING BEFORE THE PRECIPITATION TRANSITIONS TO PERIODS OF RAIN. AT
KFAY, THE LOW STRATUS WILL GIVE WAY TO IMPROVING CONDITIONS TOWARD
LATE MORNING AND ESPECIALLY THIS AFTERNOON WITH MVFR/VFR CONDITIONS
ARE EXPECTED. ADDITIONAL SHOWERS AND A FEW THUNDERSTORMS ARE
EXPECTED THIS AFTERNOON AND EVENING BEFORE THE PRECIPITATION
TRANSITIONS TO PERIODS OF RAIN LATE TONIGHT. ANOTHER ROUND OF IFR
TO LIFR STRATUS APPEARS LIKELY AGAIN TONIGHT.
LIGHT MAINLY NORTH TO EAST-NORTHEAST WINDS AT LESS THAN 8 KTS ARE
EXPECTED THIS MORNING WITH WINDS INCREASING TO AROUND 10KTS WITH A
FEW GUSTS THIS AFTERNOON AND EVENING.
LOOKING BEYOND 12Z WEDNESDAY, WIDESPREAD IFR/LIFR RESTRICTIONS ARE
APT TO BE ONGOING AT DAYBREAK WEDNESDAY. CONDITIONS MAY IMPROVE
SLIGHTLY WEDNESDAY AFTERNOON, BUT WIDESPREAD STRATUS WITH AT LEAST
SUB-VFR CONDITIONS ARE EXPECTED THROUGH THURSDAY. CONDITIONS WILL
IMPROVE ON FRIDAY AND SATURDAY AS VFR CONDITIONS ARRIVE. -BLAES
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...BLAES/HARTFIELD
AVIATION...BLAES
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