663
FXUS62 KRAH 241012
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
612 AM EDT SUN MAY 24 2026
WHAT HAS CHANGED
* LOWERED DAYTIME HIGH TEMPERATURES FOR SUNDAY.
KEY MESSAGES
AS OF 300 AM SUNDAY...
1) CAD WEDGE SLOWLY TRIES TO ERODE TODAY. ISOLATED TO SCATTERED
SHOWERS AND STORMS WILL BE POSSIBLE AGAIN TODAY IN A LOW
PREDICTABILITY REGIME.
2) WARM AND UNSEASONABLY HUMID/MUGGY THROUGH MID-WEEK, WITH ABOVE
AVERAGE CHANCES OF RAIN/CONVECTION
3) TRENDING MILDER AND PROGRESSIVELY DRIER, WITH RESPECT TO BOTH
HUMIDITY AND RAIN CHANCES LATE WEEK INTO NEXT WEEKEND
DISCUSSION
AS OF 300 AM SUNDAY...
KEY MESSAGE 1... CAD WEDGE SLOWLY TRIES TO ERODE TODAY. ISOLATED TO
SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE AGAIN TODAY IN A LOW
PREDICTABILITY REGIME.
THE LATEST SURFACE ANALYSIS REVEALS THE STUBBORN CAD WEDGE EXTENDS
ACROSS MUCH OF NC, WITH THE EXCEPTION OF THE COAST. THE BOUNDARY
ALSO STRETCHES INTO UPSTATE SC, MOVING LITTLE IN THE PAST 24 HOURS.
THE 00Z GSO SOUNDING ALSO INDICATED A STRENGTHENING OF THE INVERSION
IN THE LOWEST FEW KFT. WITH THAT, THE MAIN FORECAST CHALLENGE WILL
BE HOW MUCH THE WEDGE BOUNDARY WILL ERODE, AND IF SO, HOW FAR NORTH
IT WILL DO SO. MUCH OF THE GLOBAL AND REGIONAL, AS WELL AS HIGH-RES
GUIDANCE, INDICATES THAT AS EAST-SOUTHEASTERLY FLOW DEVELOPS AROUND
THE EDGES OF THE RETREATING WEDGE, THIS SHOULD HELP TO AT LEAST
FAVOR BREAKS IN THE LOW CLOUDS. HOWEVER, THE FLOW IS FAIRLY WEAK
FROM THE SURFACE TO 850-MB, AROUND 5 TO 10 MPH AT BEST. IF ANY LIGHT
RAIN OR PATCHY DRIZZLE CAN DEVELOP IN THE LOW-LEVEL WAA REGIME, THAT
COULD ALLOW THE WEDGE TO HOLD IN PLACE LONGER THAN ANTICIPATED
THROUGH DIABATIC EFFECTS. THE LATEST FORECAST TRENDED LOWER WITH
HIGHS, FROM THE LOW TO MID 70S NW TO LOW 80S SE. AS WE SAW
YESTERDAY, THESE COULD BUST TOO WARM, OR TOO LOW IF THE WEDGE BREAKS
EARLIER THAN EXPECTED. WE THINK THE WEDGE SHOULD ERODE IN OUR
SOUTHERN ZONES, BUT IT BECOMES A BIT TRICKER NORTH AND WEST OF US-
1/US-64, WHERE LOW CLOUDS MAY PERSIST LONGER THAN ANTICIPATED.
STORM CHANCES WILL PERSIST AGAIN THIS AFTERNOON AND EVENING, ALBEIT
WITH LOW PREDICTABILITY. THE BEST CHANCE FOR ISOLATED TO SCATTERED
ACTIVITY WOULD APPEAR TO BE ALONG THE SANDHILLS AND COASTAL PLAIN,
WHERE THE WEDGE WILL ERODE AND INSTABILITY CAN BE REALIZED. A SEA-
BREEZE MAY ALSO PROVIDE LIFT IN THIS REGION. SUBTLE DISTURBANCES IN
THE SOUTHWEST MID-LEVEL FLOW WILL ADDITIONALLY SUPPORT ISOLATED
STORM ACTIVITY ELSEWHERE, BUT CONFIDENCE ON COVERAGE IS NOT GREAT.
IF THE WEDGE COMPLETELY ERODES AS THE HREF SUGGESTS, STORMS MAY
REACH THE PIEDMONT LATE IN THE EVENING. WHILE MOST STORM ACTIVITY
SHOULD WANE BY MIDNIGHT WITH LOSS OF HEATING, REMNANT MCVS UPSTREAM
COULD FAVOR PATCHY SHOWERS OVERNIGHT ACROSS THE WEST.
KEY MESSAGE 2... WARM AND UNSEASONABLY HUMID/MUGGY THROUGH MID-WEEK,
WITH ABOVE AVERAGE CHANCES OF RAIN/CONVECTION
BETWEEN A SUB-TROPICAL HIGH SW OF BERMUDA AND A TROUGH THAT WILL
RELOAD OVER THE SRN PLAINS AND LWR MS VALLEY, A PLUME OF PWS AROUND
2" AND 150-190% OF NORMAL, AND MCVS, WILL BE DIRECTED FROM THE GULF
TO THE CAROLINAS AND SRN MIDDLE ATLANTIC THROUGH WED.
AT THE SURFACE, A FRONT WILL RETREAT FROM NC NWD AND INTO THE
VIRGINIAS BY WED, THEN PROBABLY SETTLE SWD AND THROUGH NC AGAIN ON
THU. SOME DEGREE OF A THETA-E GRADIENT, DIABATICALLY-REINFORCED AND
MODULATED BY EPISODES OF CONVECTION ACROSS THE SOUTHEAST AND
CAROLINAS, WILL LIKELY REMAIN ACROSS THE WARM SECTOR TO THE SOUTH OF
THAT FRONT.
INFLUENCE FROM THE FORCING FEATURES AMID THE DEEP MOIST AXIS NOTED
ABOVE WILL FAVOR ABOVE AVERAGE PROBABILITIES OF RAIN/CONVECTION, BUT
WITH LOW PREDICTABILITY OF FOOTPRINTS OF HEAVIEST RAIN OF GENERALLY
1-3", LOCALLY HIGHER. IT WILL ALSO BE UNSEASONABLY WARM AND HUMID,
WITH TEMPERATURES WARMING WELL INTO THE 80S THROUGH WED AND
ACCOMPANIED BY SURFACE DEWPOINTS IN THE UPR 60S TO AROUND 70 F, AND
WITH ASSOCIATED LOW TEMPERATURES NOT MUCH LOWER THAN THOSE SURFACE
DEWPOINT VALUES.
KEY MESSAGE 3... TRENDING MILDER AND PROGRESSIVELY DRIER, WITH
RESPECT TO BOTH HUMIDITY AND RAIN CHANCES LATE WEEK INTO NEXT WEEKEND
THE SUB-TROPICAL HIGH INITIALLY OFF THE SOUTH ATLANTIC COAST (SW OF
BERMUDA) WILL WEAKEN AND RETREAT INTO THE CARIBBEAN, AS A NEGATIVE
HEIGHT ANOMALY AND SURROUNDING TROUGH DEVELOP ACROSS ATLANTIC
CANADA, ANOTHER PROGRESSES SLOWLY INTO THE GREAT BASIN, AND A REX
BLOCK DEVELOPS BETWEEN THE TWO AND ACROSS CNTL NOAM (CENTERED OVER
THE MS VALLEY) THROUGH LATE WEEK. THAT BLOCKING PATTERN, AND MOSTLY
NWLY FLOW ALOFT OVER THE MIDDLE ATLANTIC, WILL THEN LIKELY PERSIST
THROUGH NEXT WEEKEND AND PROBABLY BEYOND INTO THE FOLLOWING WEEK.
AT THE SURFACE, A NRN STREAM COLD FRONT WILL PROGRESS ACROSS THE
GREAT LAKES AND MIDDLE ATLANTIC AND MAY ULTIMATELY OVERTAKE THE LEAD
FRONT ACROSS THE CAROLINAS BY THU NIGHT-FRI, WITH FOLLOWING WEAK
HIGH PRESSURE AND A DRIER AIRMASS THAT WILL LIKELY INFILTRATE CNTL
NC BY FRI. A REINFORCING FRONT AND FOLLOWING ANTICYCLONIC FLOW AND
CP AIR WILL THEN PROBABLY SETTLE ACROSS THE MIDDLE ATLANTIC AND INTO
CNTL NC NEXT WEEKEND, BENEATH AND DOWNSTREAM OF THE AFOREMENTIONED,
PERSISTENT BLOCKING PATTERN ALOFT.
ALTHOUGH OUR OFFICIAL FORECAST, POPULATED FROM THE NATIONAL BLEND OF
MODELS AND WPC, MAINTAINS SOLID CHANCE TO LOW LIKELY POP FRI-SUN,
THAT TIME PERIOD WILL LIKELY PROVE MAINLY DRY, AS THE PATTERN
DESCRIBED ABOVE SHOULD SHUNT THE DEEP MOIST AXIS AND FRONTAL ZONES
SOUTH AND SOUTHWEST OF CNTL NC.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
AS OF 612 AM SUNDAY...
WIDESPREAD LIFR CONDITIONS PERSIST THIS MORNING. THE CAD WEDGE
REMAINS IN PLACE. WE CAN EXPECT THESE LIFR CONDITIONS TO PERSIST AT
LEAST UNTIL MID-MORNING SUN WITH THE LACK OF ANY APPRECIABLE AIRMASS
CHANGE. THE MAJORITY OF THE HIGH-RES ENSEMBLE DATA SUGGEST THAT AS
SOUTHERLY FLOW RETURNS, THE CAD WEDGE WILL GRADUALLY TRY TO ERODE
FROM SOUTH TO NORTH. OVERALL CONFIDENCE ON HOW FAR NORTH IT ERODES
IS NOT GREAT GIVEN HOW MODELS HAVE STRUGGLED WITH THIS AIRMASS OVER
THE PAST SEVERAL DAYS. WITH THAT SAID, EXPECT A GRADUAL IMPROVEMENT
IN CEILINGS, TO MVFR ACROSS THE NORTH AND VFR AT FAY. CONDITIONS ARE
FAVORED TO REMAIN SUB-VFR AT GSO/INT, WITH A MIXTURE OF MVFR/VFR AT
RDU/RWI. THE CURRENT FORECAST COULD BE TOO PESSIMISTIC IF THE CAD
WEDGE ERODES FASTER THAN PRESENTLY ANTICIPATED. LIFR/IFR CONDITIONS
WILL REDEVELOP AGAIN TONIGHT, DRIVEN MAINLY BY LOW STRATUS AND NOT
FOG GIVEN SOUTHERLY WINDS KEEPING THE SURFACE STIRRED.
AS FOR STORM CHANCES, CONFIDENCE IS NOT GREAT, BUT FEEL FAY HAS THE
BEST CHANCE OF SEEING THUNDER ALONG THE ERODING WEDGE AND/OR SEA-
BREEZE. RDU AND RWI ALSO HAVE A THREAT BUT WITH LOWER CONFIDENCE DUE
TO THE UNCERTAINTY WITH THE ERODING WEDGE BOUNDARY AND LESS
INSTABILITY. PATCHY AREAS OF SHOWERS/DRIZZLE WILL BE POSSIBLE
OVERNIGHT WITH WEAK DISTURBANCES TRACKING IN FROM THE SOUTHWEST.
OUTLOOK: DAILY CHANCES FOR SHOWERS AND STORMS WILL CONTINUE THROUGH
THE PERIOD, ALONG WITH MORNING FOG OR STRATUS.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
MAY 25: KGSO: 70/2019 KRDU: 71/2019 KFAY: 71/2019
MAY 26: KGSO: 70/2019 KRDU: 73/2011 KFAY: 75/2004
MAY 27: KGSO: 72/1991 KRDU: 72/1991 KFAY: 72/2006
MAY 28: KGSO: 70/2012 KRDU: 74/1914
MAY 29: KRDU: 72/2012 KFAY: 73/2018
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...KREN/MWS
AVIATION...KREN
CLIMATE...RAH
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