909
FXUS62 KRAH 201856
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
256 PM EDT SUN SEP 20 2026
WHAT HAS CHANGED
* NO MAJOR CHANGES.
KEY MESSAGES
AS OF 255 PM SUNDAY...
1) CAN'T RULE OUT AN ISOLATED SHOWER OR STORM IN THE NW PIEDMONT
LATE THIS AFTERNOON AND EARLY THIS EVENING.
2) AN APPROACHING COLD FRONT WILL BRING THE POTENTIAL
FOR STRONG TO SEVERE THUNDERSTORMS ON MONDAY, FOLLOWED BY A CHANCE
FOR HEAVY RAINFALL ON TUESDAY.
3) COLD-AIR DAMMING WILL DEVELOP BY THE MIDDLE OF THE
WEEK, BRINGING SEVERAL DAYS OF WELL BELOW NORMAL TEMPERATURES.
DISCUSSION
AS OF 255 PM SUNDAY...
KEY MESSAGE 1... CAN'T RULE OUT AN ISOLATED SHOWER OR STORM IN THE
NW PIEDMONT LATE THIS AFTERNOON AND EARLY THIS EVENING.
SUBTROPICAL RIDGING EXTENDS FROM TX INTO THE MID MS VALLEY AS A
MID/UPPER LOW IS CENTERED OVER THE EASTERN GULF. SCATTERED
CONVECTION IS BEGINNING TO DEVELOP OVER THE WESTERN NC MOUNTAINS,
WHILE AN AREA OF DECAYING SHOWERS ASSOCIATED WITH A RIPPLE IN THE
FLOW ALOFT IS LOCATED OVER SOUTHERN WV AND NORTHWESTERN VA. MANY
HIGH-RES MODELS HAVE SOME MORE ISOLATED SHOWERS AND STORMS
DEVELOPING OVER SW VA AND NW NC LATER THIS AFTERNOON, PERHAPS BEING
ENHANCED BY THE PREVIOUSLY MENTIONED UPPER DISTURBANCE. GIVEN SBCAPE
OF 1000-2000 J/KG AND A TONGUE OF RELATIVELY HIGHER PW VALUES AROUND
1.7" ACROSS THE NW PIEDMONT, A FEW OF THESE SHOWERS AND STORMS MAY
MAKE IT AS FAR AS OUR NW PIEDMONT BEFORE DIMINISHING WITH LOSS OF
DAYTIME HEATING. THE BEST CHANCE WILL BE FROM ABOUT 6-10 PM. NO
ORGANIZED SEVERE WEATHER IS EXPECTED, BUT CAN'T RULE OUT ISOLATED
GUSTY WINDS GIVEN MARGINAL DCAPE OF 600-800 J/KG.
KEY MESSAGE 2... AN APPROACHING COLD FRONT WILL BRING THE POTENTIAL
FOR STRONG TO SEVERE THUNDERSTORMS ON MONDAY, FOLLOWED BY A CHANCE
FOR HEAVY RAINFALL ON TUESDAY.
AS A COLD FRONT SLOWLY MOVES SOUTH ACROSS THE APPALACHIANS,
MONDAY SHOULD BE THE LAST DAY WITH WIDESPREAD UPPER 80 AND 90 DEGREE
TEMPERATURES ACROSS CENTRAL NORTH CAROLINA. ALTHOUGH MONDAY MORNING
WILL START OFF SUNNY, AS THE FRONT BEGINS TO DROP TO THE SOUTH,
CLOUD COVER WILL INCREASE AND SHOWERS/STORMS WILL BEGIN TO FIRE
EARLY IN THE AFTERNOON ALONG THE VA/NC BORDER. THE GREATEST CHANCE
FOR RAIN WILL BE ALONG THE STATE BORDER, ALTHOUGH MOST LOCATIONS
WILL HAVE AT LEAST SOME CHANCE FOR RAIN, PARTICULARLY IN THE
EVENING. THE WIND SHEAR THAT COULD PROVIDE BETTER ORGANIZATION FOR
THUNDERSTORMS SHOULD REMAIN TO THE NORTH ACROSS VIRGINIA, ALTHOUGH
MUCAPE LOCALLY WILL RANGE FROM 1000 TO 2000 J/KG. THERE WILL STILL
BE THE POTENTIAL FOR SOME ISOLATED STRONG TO SEVERE THUNDERSTORMS
ACROSS CENTRAL NORTH CAROLINA, PARTICULARLY TO THE WEST OF US-1. THE
MOST LIKELY TIMING FOR SEVERE THUNDERSTORMS SHOULD BE BETWEEN 2-6PM
WITH THE THREAT COMING FROM DAMAGING WINDS. IN ADDITION, CANNOT RULE
OUT THE POTENTIAL FOR SOME FLASH FLOODING NEAR AND AROUND THE TRIAD
WITH THE URBAN ENVIRONMENT ALLOWING FOR A BETTER CHANCE OF EXCESSIVE
RAINFALL OCCURRING.
WITH THE FRONT MOVING SOUTH INTO NORTH CAROLINA MONDAY NIGHT INTO
TUESDAY, THAT WILL PUT THE FORECAST AREA ONTO THE COOL SIDE OF THE
BOUNDARY, WHICH SHOULD REDUCE/ELIMINATE THE CHANCE FOR SEVERE
WEATHER ON TUESDAY. HOWEVER, WIDESPREAD RAINFALL IS EXPECTED, AND
ALONG THE COOL SIDE OF THE BOUNDARY, HIGH RAINFALL RATES WILL STILL
BE POSSIBLE, WITH THE ENTIRE AREA WILL BE UNDER A MARGINAL (LEVEL 1
OF 4) RISK FOR EXCESSIVE RAINFALL, PRIMARILY TUESDAY AFTERNOON.
KEY MESSAGE 3... COLD-AIR DAMMING WILL DEVELOP BY THE MIDDLE OF THE
WEEK, BRINGING SEVERAL DAYS OF WELL BELOW NORMAL TEMPERATURES.
WITH THE FRONT SLIPPING TO THE SOUTH OF THE AREA LATE TUESDAY,
A RIDGE OF HIGH PRESSURE WILL EXTEND SOUTH INTO THE CAROLINAS FROM A
STRONG HIGH THAT WILL REMAIN OVER QUEBEC FOR SEVERAL DAYS. WHILE
MODELS ARE COMING INTO BETTER AGREEMENT THAT A LOW PRESSURE SYSTEM
WILL DEVELOP OFF THE ATLANTIC COAST THURSDAY AND MOVE NORTH, THERE
IS GOOD MODEL AGREEMENT THAT A SUSTAINED PERIOD OF NORTHEAST WIND
AND WIDESPREAD CLOUD COVER WILL OCCUR WEDNESDAY AND THURSDAY.
WEDNESDAY WILL BE THE FIRST FULL DAY OF FALL, AND IT WILL FEEL LIKE
IT - LOCATIONS NORTH AND WEST OF I-85 ARE UNLIKELY TO RISE OUT OF
THE 60S BOTH WEDNESDAY AND THURSDAY, WITH THE REST OF THE AREA ONLY
RISING INTO THE 70S. WIDESPREAD LIGHT RAIN IS LIKELY ON WEDNESDAY,
WITH CONDITIONS BEGINNING TO DRY OUT ON THURSDAY. THE PATTERN, BOTH
WITH TEMPERATURE AND PRECIPITATION, SHOULD BEGIN TO MODERATE FOR
FRIDAY THROUGH SUNDAY, PRIMARILY BASED ON MODEL PREDICTIONS OF THE
ATLANTIC LOW MOVING TOWARDS NEW ENGLAND AND PUSHING THE RIDGE OF
HIGH PRESSURE TO THE WEST. THE END OF THIS WEEK LOOKS TO FAVOR
MOSTLY SUNNY SKIES, MINIMAL CHANCES FOR RAINFALL, AND HIGHS IN THE
70S. ROXBORO COULD SEE ITS TEMPERATURE DIP INTO THE 40S ON SATURDAY
MORNING FOR THE FIRST TIME IN SEVERAL MONTHS.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
AS OF 220 PM SUNDAY...
THROUGH 18Z MONDAY: VFR CONDITIONS WILL PREVAIL ACROSS CENTRAL NC
THROUGH THIS EVENING, WITH MAINLY JUST SOME FAIR WEATHER CUMULUS.
THE ONLY CHANCE OF PRECIPITATION IS THE POTENTIAL FOR AN ISOLATED
SHOWER OR STORM IN THE NW PIEDMONT (INCLUDING INT AND GSO) AROUND
22Z-02Z. LATE TONIGHT AND EARLY MONDAY MORNING, PATCHY FOG AND VERY
LOW STRATUS WILL BE POSSIBLE ONCE AGAIN, WITH THE BEST CHANCE IN THE
SANDHILLS AND COASTAL PLAIN (INCLUDING FAY AND RWI). HOWEVER,
GUIDANCE DIFFERS ON THE EXTENT OF FOG AND LOW STRATUS, AND ITS
OCCURRENCE WAS ISOLATED THIS MORNING WITH RWI THE ONLY TAF SITE
REPORTING ANY RESTRICTIONS. SO CONFIDENCE IS FAIRLY LOW AT THIS
TIME.
OUTLOOK: A COLD FRONT APPROACHING MONDAY WILL BRING A BETTER CHANCE
OF SHOWERS AND STORMS TO THE ENTIRE AREA. UNSETTLED WEATHER MAY
PERSIST UNDER A CAD-REGIME DEVELOPING TUESDAY-WEDNESDAY, WHERE
PERIODS OF SUB-VFR STRATUS AND FOG MAY EXIST INTO LATE WEEK,
ESPECIALLY EACH EARLY MORNING.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...DANCO/GREEN
AVIATION...DANCO/NP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page