925
FXUS62 KRAH 230859
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
459 AM EDT THU JUL 23 2026
WHAT HAS CHANGED
* WHILE HEAVY, CONVECTIVE RAINS ARE ONGOING AND EXPECTED TO
CONTINUE, WITH MULTI-INCH TOTALS STILL LIKELY, PRECIPITATION RATES
MAY BE JUST LOW ENOUGH TO PRECLUDE THE OCCURRENCE OF MORE THAN
SCATTERED INSTANCES OF FLASH FLOODING.
KEY MESSAGES
AS OF 455 AM THURSDAY...
1) AN AXIS OF SHOWERS STORMS WILL PROGRESS SLOWLY SSEWD ACROSS CNTL
NC THROUGH EARLY FRIDAY, WITH AN ASSOCIATED RISK OF EXCESSIVE RAIN.
2) THE SLOW MOVING COLD FRONT ACROSS THE CAROLINAS WILL MOVE ACROSS
EASTERN NC AND INTO NORTHERN SC RESULTING IN A CONTINUED THREAT OF
RAIN, FOCUSED ACROSS SOUTHERN AREAS WHERE THE RAIN COULD BE LOCALLY
HEAVY.
3) AFTER ANOTHER COOL AND RAINY DAY SATURDAY, THE CHANCE OF RAIN
WILL DECREASE AND TEMPERATURES WILL RETURN TO NORMAL LATE JULY
VALUES.
DISCUSSION
AS OF 455 AM THURSDAY...
KEY MESSAGE 1... AN AXIS OF SHOWERS STORMS WILL PROGRESS SLOWLY
SSEWD ACROSS CNTL NC THROUGH EARLY FRIDAY, WITH AN ASSOCIATED RISK
OF EXCESSIVE RAIN.
A SHORTWAVE TROUGH, EVIDENT IN GOES-E WATER VAPOR SATELLITE DATA
OVER THE SRN BORDER OF ON/QC, WILL LIFT NEWD THROUGH THE ST.
LAWRENCE RIVER VICINITY THROUGH THIS EVENING. RISING HEIGHTS WILL
FOLLOW THE WAVE AND RESULT THROUGHOUT THE LWR GREAT LAKES, MIDDLE
ATLANTIC, AND NORTHEAST, WITH RELATED DEAMPLIFICATION AND WEAKENING
OF A LONGWAVE ERN CONUS TROUGH. CNTL NC WILL BE MOSTLY DISPLACED
FROM THE INFLUENCE OF THE SHORTWAVE TROUGH BUT IN CONTINUED VERY
MOIST AND BROADLY CYCLONIC FLOW, WITH THE FORMER HIGHLIGHTED BY A
TOP 10 ALL-TIME OBSERVED PW OF 2.32" AT GSO LAST EVENING. WEAKLY
VEERING, UNIFORMLY-STRONG FLOW OF 30-40 KTS IN THE 850-500 MB LAYER
WILL CONTINUE TO BE DIRECTED INTO A SIMILARLY-ALIGNED LOW-LEVEL
FRONTAL ZONE OVER THE SRN MIDDLE ATLANTIC.
THAT LOW-LEVEL FRONTAL ZONE WILL TEND TO CONSOLIDATE AND STRENGTHEN,
AS A SYNOPTIC COLD FRONT NOW PROGRESSING STEADILY THROUGH S-CNTL VA
NEARS AND PROBABLY EVENTUALLY OVERTAKES LATER TODAY A NEARLY
STATIONARY OUTFLOW BOUNDARY/EFFECTIVE FRONT DRAPED FROM EDE-FBG-CLT
IN E-CNTL THROUGH S-CNTL NC. THE MERGED FRONT WILL THEN SETTLE INTO,
AND BECOME QUASI-STATIONARY OVER, THE ERN CAROLINAS LATE TONIGHT-
FRI.
ISENTROPIC LIFT INDUCED BY A 30-35 KT SWLY LOW-LEVEL JET AND WAA
INTERSECTING THE FRONTS, AND A LOW-LEVEL FRONTOGENETICAL
CIRCULATION, WILL FAVOR LIFT IN THE AFOREMENTIONED DEEPLY MOIST
ENVIRONMENT OVER CNTL NC. WHEN COMBINED WITH ONLY WEAK NNWLY UPWIND
PROPAGATION VECTORS RESULTING FROM THE WIND PROFILE NOTED ABOVE, AND
ASSOCIATED SLOW SSEWD PROPAGATION OF THE AXIS OF ONGOING CONVECTION,
AND A CONTINUED CONDITIONALLY UNSTABLE THERMODYNAMIC PROFILES WITH
GENERALLY 1000-1500 J/KG OF MUCAPE, THE ENVIRONMENT WILL REMAIN
CONDUCIVE FOR SLOW-MOVING CONVECTION WITH RISK OF FLASH FLOODING.
THIS RISK WILL BE GREATEST OVER THE TRIANGLE THIS MORNING, PRIOR TO
THE ARRIVAL OF THE SYNOPTIC FRONT FROM THE NORTH AND FOLLOWING DRIER
AIR IN THE LOW-LEVELS (EG. SURFACE DEWPOINTS NOW FALLING THROUGH THE
50S-60S THROUGHOUT NRN AND CNTL VA). AFTER AS MUCH AS 4-5" INCHES OF
RAIN FELL OVER THE NW PIEDMONT OVERNIGHT, BUT WITH RATES
INSUFFICIENT TO PRODUCE ANY NOTABLE FLASH FLOODING, THE AXIS OF
CONVECTION AND RISK OF FLOODING APPEARS TO HAVE NOW SHIFTED JUST
SOUTH OF THE TRIAD.
WHILE MOST OF CNTL NC IS NOT OUTLOOKED BEYOND GENERAL THUNDER IN THE
LATEST SWODY1, VWP-OBSERVED AND SPC/OBJECTIVE MESOANALYSIS-
CORROBORATED 0-1 KM BULK SHEAR OF 20-25 KTS AND 0-1 KM SRH OF 100-
150 M2/S2 REMAIN FAVORABLE FOR A WEAK SPINUP IN CELLS THAT DEVELOP
AND TRACK ALONG THE EFFECTIVE FRONT - MUCH LIKE THE EARLIER JOHNSTON
CO. CELL THAT EXHIBITED A VROT OF 20-25 KTS AROUND 2-4 FT ARL AND
NECESSITATED A SVR WITH TOR POSSIBLE TAG.
IT WILL OTHERWISE REMAIN UNSEASONABLY MILD AND WITH A CHANCE TO SET
RECORD LOW MAXIMUM TEMPERATURES OVER THE PIEDMONT, CONTRASTED BY 80S
IN THE WARM SECTOR FROM THE SRN PIEDMONT TO THE SANDHILLS AND CNTL
COASTAL PLAIN.
KEY MESSAGE 2... THE SLOW MOVING COLD FRONT ACROSS THE CAROLINAS
WILL MOVE ACROSS EASTERN NC AND INTO NORTHERN SC RESULTING IN A
CONTINUED THREAT OF RAIN, FOCUSED ACROSS SOUTHERN AREAS WHERE THE
RAIN COULD BE LOCALLY HEAVY.
FRIDAY'S FORECAST AND POSSIBLE IMPACTS REMAIN ARE CHALLENGING AS THE
OVERALL TREND IS FOR THE GREATEST PRECIPITATION AND THE POTENTIAL
FOR HEAVY OR EXCESSIVE RAIN FOCUSING TO THE SOUTHEAST. EXPECT ONE
BATCH OF SHOWERS AND STORMS TO BE EXITING CENTRAL NC OFF TO THE EAST
AND SOUTHEAST ON FRIDAY MORNING FOLLOWED BY A BIT OF A LULL ACROSS
MUCH OF THE AREA DURING THE DAY. AS ANOTHER DISTURBANCE ALOFT
APPROACHES, FORCING FOR ASCENT SHOULD INCREASE, AND SHOWERS AND
STORMS WILL LIKELY REDEVELOP ON FRIDAY NIGHT. THE RAIN SHOULD BE
LIGHTER AND LESS CONVECTIVE ACROSS NORTHERN AREAS BUT IN LOCATIONS
SOUTH OF U.S. ROUTE 64, INSTABILITY AND DEEP MOISTURE WILL BUCKLE
NORTH AND THE PRECIPITATION WILL BE MORE WIDESPREAD, CONVECTIVE AND
POTENTIALLY HEAVY. THE WPC QPF FORECAST FOR FRIDAY AND FRIDAY NIGHT
RANGES LESS THAN 0.25 INCHES IN THE TRIAD AND NEAR THE VA BORDER,
0.25 TO 0.5 INCHES IN THE TRIANGLE AND ROCKY MOUNT AREAS AND 0.5 TO
1.0 INCHES IN THE SANDHILLS AND SOUTHERN COASTAL PLAIN. WITH THIS IN
MIND, WILL KEEP THE CURRENT EXPIRATION TIME ON THE FLOOD WATCH AS IS
WHILE NOTING THAT IT MAY BE NECESSARY TO EXTEND THE WATCH ACROSS
SOUTHERN AND SOUTHEASTERN AREAS. FRIDAY WILL BE ANOTHER DAY WITH
BELOW AVERAGE TEMPERATURES, AS MUCH AS 10 TO 15 DEGREES BELOW
AVERAGE IN THE NORTH WITH HIGHS RANGING FROM THE MID 70S IN THE
TRIAD TO THE LOWER 80S IN THE SANDHILLS.
KEY MESSAGE 3... AFTER ANOTHER COOL AND RAINY DAY SATURDAY, THE
CHANCE OF RAIN WILL DECREASE AND TEMPERATURES WILL RETURN TO NORMAL
LATE JULY VALUES.
THE STATIONARY FRONT SHOULD REMAIN SOMEWHERE ALONG THE NORTH
CAROLINA/SOUTH CAROLINA BORDER ON SATURDAY, KEEPING A CHANCE FOR
SHOWERS ACROSS THE ENTIRE AREA, WITH THE HIGHEST CHANCES IN THE
SOUTH. AS THE FRONT CONTINUES TO WEAKEN, JUST AN ISOLATED
THUNDERSTORM WILL BE POSSIBLE ON SUNDAY, AND MONDAY APPEARS TO BE
THE FIRST WIDESPREAD DAY OF DRY WEATHER IN SEVERAL DAYS. AS LOW
PRESSURE MOVES ALONG THE US/CANADIAN BORDER DURING THE BEGINNING OF
NEXT WEEK, THE ACCOMPANYING COLD FRONT COULD MAKE IT AS FAR SOUTH AS
THE CAROLINAS, BRINGING ANOTHER CHANCE FOR SHOWERS AND STORMS.
SATURDAY WILL BE YET ANOTHER COOL DAY, WITH HIGHS RANGING FROM THE
MID 70S TO THE MID 80S. A RETURN TO SUNNY SKIES ON SUNDAY, HOWEVER,
SHOULD BRING A WARMING TREND WITH HIGHS RETURNING TO THE 80S
EVERYWHERE, AND HIGHS WILL RETURN TO NEAR NORMAL VALUES IN THE LOW
TO MID 90S MONDAY THROUGH WEDNESDAY.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 235 AM THURSDAY...
AN AXIS OF CONVECTION --WIDESPREAD, MODERATE TO HEAVY SHOWERS AND
WIDELY SCATTERED STORMS-- WILL CONTINUE TO FOCUS ALONG A 925-850 MB
FRONT ACROSS PIEDMONT SITES THIS MORNING. OTHER, SCATTERED
CONVECTION WILL MEANWHILE CONTINUE TO LAUNCH ALONG AND NORTH OF A
NEARLY STATIONARY OUTFLOW BOUNDARY/EFFECTIVE FRONT MCZ-POB-CLT,
INCLUDING AT RWI, AS MOIST SWLY FLOW IMPINGES UPON AND RIDES ATOP
THE OUTFLOW BOUNDARY. WHILE FLIGHT RESTRICTIONS WILL OCCUR FIRST AND
BE MAXIMIZED IN THIS CONVECTION, AREAS OF IFR-MVFR CEILINGS ARE
LIKELY TO DEVELOP IN THE RAIN-COOLED AIR NORTH/POLEWARD OF THE
OUTFLOW BOUNDARY THROUGH THE MORNING. THIS BOUNDARY, AND BOTH FOCUS
FOR CONVECTION AND AREAS OF FLIGHT RESTRICTIONS, WILL PROBABLY NOT
REACH FAY UNTIL THIS AFTERNOON. SOME LIFTING OF CEILINGS THROUGH
MVFR RANGE WILL MEANWHILE RESULT AT PIEDMONT SITES, ACCOMPANIED BY
BRIEFLY GUSTY NLY SURFACE WINDS, AS A REINFORCING SYNOPTIC FRONT AND
FOLLOWING DRIER AIR NOW OVER CNTL VA CONTINUE SWD AND INTO CNTL NC
LATER TODAY. NOCTURNAL COOLING WILL SUPPORT A LOWERING OF CEILINGS
INTO IFR RANGE ONCE AGAIN TONIGHT, ACCOMPANIED BY CONTINUED WAVES OF
ELEVATED CONVECTION ALONG AND NORTH OF THE AFOREMENTIONED FRONTS
THAT WILL HAVE PROBABLY MERGED AND STALLED OVER THE ERN CAROLINAS.
OUTLOOK: COLD AIR DAMMING TO THE NORTH AND WEST OF THE FRONTS WILL
FAVOR OVERNIGHT-MORNING IFR-MVFR CEILINGS AND POSSIBLY SOME PERIODS
OF LIGHT RAIN OVER CNTL NC FRI-SAT. SOME CONTINUED ELEVATED
CONVECTION WILL ALSO CONTINUE AT FAY DURING THAT TIME, IN RELATIVELY
CLOSER PROXIMITY TO THE STALLED FRONT AND INSTABILITY AXIS.
CLIMATE
RECORD LOW MAXIMUM TEMPERATURES:
JULY 23: KGSO: 73/2019 KRDU: 76/1921
JULY 24: KFAY: 81/1985
RAH WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH THROUGH THURSDAY EVENING FOR NCZ007>011-021>028-
038>041.
FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH FRIDAY MORNING
FOR NCZ042-043-073>078-083>086-088-089.
DISCUSSION...MWS/BLAES/GREEN
AVIATION...MWS
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