421
FXUS62 KRAH 221730
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
130 PM EDT FRI MAY 22 2026
WHAT HAS CHANGED
* CONTINUED INCREASING CONFIDENCE IN WIDESPREAD RAIN, LOCALLY HEAVY
AT TIMES, THROUGH THE MIDDLE OF NEXT WEEK, ESPECIALLY OVER THE
PIEDMONT. RAINFALL AMOUNTS DURING THIS TIME ARE EXPECTED TO RANGE
FROM 2 TO 4 INCHES ON AVERAGE.
KEY MESSAGES
AS OF 400 AM FRIDAY...
1) FRIDAY AND SATURDAY WILL BE COOL AND RAINY OVER MUCH OF THE
PIEDMONT AND NORTHERN COASTAL PLAIN WITH A CAD WEDGE IN PLACE. SOUTH
AND EAST OF THE WEDGE WILL BE WARMER WITH SCATTERED SHOWERS AND
STORMS.
2) ABOVE AVERAGE CHANCES OF RAIN/CONVECTION WILL CONTINUE THROUGH
MID-WEEK, DURING WHICH TIME A PLUME OF DEEP MOISTURE WILL BE
DIRECTED AROUND A SUB-TROPICAL HIGH AND ATOP A SURFACE FRONT THAT
WILL WAVER OVER THE SRN MIDDLE ATLANTIC.
DISCUSSION
AS OF 400 AM FRIDAY...
KEY MESSAGE 1... FRIDAY AND SATURDAY WILL BE COOL AND RAINY OVER
MUCH OF THE PIEDMONT AND NORTHERN COASTAL PLAIN WITH A CAD WEDGE IN
PLACE. SOUTH AND EAST OF THE WEDGE WILL BE WARMER WITH SCATTERED
SHOWERS AND STORMS.
THE BACKDOOR COLD FRONT HAS CLEARED THE REGION AND IS NOW DRAPED
FROM FAR SE NC INTO NORTHERN SC. AREAS OF LIGHT TO MODERATE RAIN ARE
ONGOING OVER THE NORTHERN PIEDMONT AND NORTHERN COASTAL PLAIN DUE TO
THE PERTURBED SW MID-LEVEL FLOW AROUND THE OFFSHORE SUBTROPICAL
RIDGE, AND PLENTY OF DEEP MOISTURE WITH PW VALUES IN THE 1.6 TO 1.8
INCH RANGE. THE MORE WIDESPREAD RAIN WILL COME TO AN END AROUND
DAYBREAK, BUT AS HIGH PRESSURE OVER NEW ENGLAND NOSES SW INTO THE
AREA, A CAD AIRMASS WILL SET UP OVER NORTHERN PORTIONS OF CENTRAL
NC. WHILE EXACTLY WHERE THE WEDGE BOUNDARY SETS UP IS STILL
UNCERTAIN, IT LOOKS MOST LIKELY TO SET UP FROM THE SOUTHERN PIEDMONT
INTO THE CENTRAL COASTAL PLAIN. EXPECT OVERCAST SKIES ALONG WITH
PATCHY LIGHT RAIN AND DRIZZLE TO THE NORTH OF IT, AS WARM MOIST AIR
OVERRUNS THE COOL STABLE BOUNDARY LAYER. HIGH TEMPERATURES THERE
WILL ONLY REACH THE MID-60S TO LOWER-70S. TO THE SOUTH OF THE
BOUNDARY, AN INVERTED TROUGH WILL SET UP, AND WITH SOME BREAKS OF
SUN AND HIGHS REACHING THE LOWER-TO-MID-80S, SBCAPE WILL GET AS HIGH
AS 500-1500 J/KG. THIS WILL RESULT IN SCATTERED SHOWERS AND STORMS
IN THOSE AREAS THIS AFTERNOON AND EVENING, WHICH COULD HAVE HEAVY
DOWNPOURS, AND THE LATEST HREF LPMM DEPICTS LOCALIZED 1-3 INCH
AMOUNTS ARE POSSIBLE. HOWEVER, ANY FLASH FLOODING WOULD BE ISOLATED
GIVEN THE ONGOING DROUGHT AND LACK OF STRONG FORCING.
AS LOBES OF MID-LEVEL VORTICITY MOVE ACROSS CENTRAL NC ON FRIDAY
NIGHT AND THE QUASI-STATIONARY SURFACE BOUNDARY REMAINS, MORE
WIDESPREAD RAIN WILL RETURN OVER THE PIEDMONT. LOWS WILL RANGE FROM
UPPER-50S TO UPPER-60S. THIS PATTERN WILL CONTINUE ON SATURDAY WITH
CONTINUED PERTURBED MID-LEVEL FLOW, PW VALUES 150-175% OF NORMAL,
AND CAD. HOWEVER, THE WEDGE BOUNDARY MAY BE A BIT FARTHER NW AS THE
SURFACE HIGH MOVES EAST OF THE NEW ENGLAND COAST AND THE CAD BEGINS
TO ERODE. THIS WOULD PLACE MORE OF CENTRAL NC IN AN UNSTABLE AIRMASS
WITH WIDESPREAD SHOWERS AND ISOLATED STORMS. THE BEST RAIN CHANCES
WILL BE ROUGHLY ALONG AND WEST OF US-1 WHERE THE 00Z HREF INDICATES
WIDESPREAD HALF INCH TO INCH AMOUNTS AND ISOLATED 1-3 INCH TOTALS
POSSIBLE ON SATURDAY AND SATURDAY NIGHT. STILL CAN'T RULE OUT
LOCALIZED FLASH FLOODING ESPECIALLY IN URBAN AND POOR DRAINAGE
AREAS. THERE IS AGAIN HIGH BUST POTENTIAL WITH TEMPERATURES, BUT FOR
NOW THE FORECAST HAS SATURDAY'S HIGHS RANGING FROM UPPER-60S IN THE
FAR NW PIEDMONT TO LOWER-TO-MID-80S SOUTH AND EAST. THE CAD WEDGE
WILL CONTINUE TO ERODE ON SATURDAY NIGHT AS THE BOUNDARY MOVES NORTH
AS A WARM FRONT. LOWS WILL BE IN THE 60S.
KEY MESSAGE 2... ABOVE AVERAGE CHANCES OF RAIN/CONVECTION WILL
CONTINUE THROUGH MID-WEEK, DURING WHICH TIME A PLUME OF DEEP
MOISTURE WILL BE DIRECTED AROUND A SUB-TROPICAL HIGH AND ATOP A
SURFACE FRONT THAT WILL WAVER OVER THE SRN MIDDLE ATLANTIC.
ANOMALOUSLY MOIST SWLY FLOW, WITH PWS AROUND 2" AND 150-175% OF
NORMAL, WILL BE DIRECTED FROM THE GULF TO THE SRN MIDDLE ATLANTIC
THROUGH WED, BETWEEN A TROUGH INVOF THE ARKLATEX AND A SUB-TROPICAL
HIGH THAT WILL RETROGRADE FROM NEAR BERMUDA AND INTO THE SOUTH
ATLANTIC COAST. THAT HIGH WILL THEN WEAKEN AND RETREAT INTO THE
CARIBBEAN, AS A DEEP TROUGH DEVELOPS ACROSS AND OFFSHORE ATLANTIC
CANADA, ANOTHER PROGRESSES INTO THE GREAT BASIN, AND A REX BLOCK
DEVELOPS BETWEEN THE TWO AND ACROSS THE MS VALLEY THROUGH LATE WEEK.
THAT BLOCKING PATTERN, AND NLY/NWLY FLOW ALOFT OVER THE MIDDLE
ATLANTIC, WILL THEN LIKELY PERSIST THROUGH NEXT WEEKEND.
AT THE SURFACE, A WEDGE FRONT THAT WILL WAVER OVER CNTL NC FOR THE
NEXT COUPLE OF DAYS WILL PROBABLY WEAKEN AND RETREAT NWWD AND INTO
THE FOOTHILLS ON SUN, WHERE IT WILL LINGER AND MERGE WITH A LEE
TROUGH MON-TUE. A SUB-TROPICAL, BERMUDA HIGH WILL OTHERWISE BULGE
WWD AND ACROSS THE SOUTH ATLANTIC COAST. THE FRONT WILL THEN
PROBABLY SAG SWD ACROSS CNTL AND SRN VA WED AND ACROSS CNTL NC WED
NIGHT, FOLLOWED BY A REINFORCING AND STRONGER, BACKDOOR FRONT
FORECAST TO MOVE ACROSS THE REGION ON THU. HIGH PRESSURE WILL FOLLOW
AND RIDGE IN THE LEE OF THE CNTL AND SRN APPALACHIANS FRI-SAT, WITH
WHAT WILL LIKELY BE DRY (LOWER IMPACT TO SENSIBLE WEATHER) CAD.
WHILE ABOVE AVERAGE CHANCES OF RAIN WILL EXIST THROUGHOUT CNTL NC
THROUGH MID-WEEK, INFLUENCE FROM THE SYNOPTIC FEATURES NOTED ABOVE
WILL FAVOR THE RELATIVE GREATEST CONVECTIVE COVERAGE AND AVERAGE
MULTI-DAY TOTAL RAINFALL AMOUNTS OF 1-3", OVER THE PIEDMONT. IT
SHOULD THEN TURN DRIER AMID THE AFOREMENTIONED RIDGING ACROSS THE
REGION DURING THE END OF NEXT WEEK AND PROBABLY THROUGH THE WEEKEND.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
AS OF 130 PM FRIDAY...
WIDESPREAD IFR CONDITIONS WILL CONTINUE ACROSS THE REGION THROUGH
THE PERIOD AS CAD WEDGE REMAINS IN PLACE. PERIODIC LIGHT RAIN AND
MIST WILL KEEP VISIBILITIES IN THE MVFR/IFR RANGE, WITH THE LOWEST
CEILINGS (~400 FT) EXPECTED LATE TONIGHT INTO SATURDAY MORNING. KFAY
AND KRDU MAY SEE A BRIEF, SLIGHT IMPROVEMENT TO LOW-END MVFR LATE
THIS AFTERNOON, THOUGH HAVE A PROB30 FOR TSRA AT KFAY THIS AFTERNOON
INTO EARLY EVENING AS STORMS BEGIN TO EXPAND NORTH. WINDS WILL
GENERALLY REMAIN OUT OF THE NORTHEAST AROUND 5-10 KT, WITH SOME
MINOR EASTERLY VEERING AT THE EASTERN SITES TOMORROW MORNING. EXPECT
VERY LITTLE RELIEF THROUGH SATURDAY AFTERNOON, WITH CEILINGS HOLDING
AT IFR LEVELS.
OUTLOOK: THE PERSISTENT CAD WEDGE IS FORECAST TO STICK AROUND
THROUGH MUCH OF SUNDAY BEFORE ERODING. WIDESPREAD IFR/LIFR STRATUS
AND PATCHY FOG WILL REMAIN A STRONG POSSIBILITY OVERNIGHT SATURDAY
INTO SUNDAY MORNING. HOWEVER, CONVECTIVE AND CEILING PATTERNS WILL
TRANSITION INTO A STANDARD DIURNAL TREND SUNDAY THROUGH MID-WEEK,
FEATURING PERIODS OF VFR/MVFR DAYTIME CONDITIONS OUTSIDE OF
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
CLIMATE
RECORD HIGH MINIMUM TEMPERATURES:
MAY 22:
KFAY: 73/2004
MAY 23:
KFAY: 72/2011
MAY 24:
KRDU: 70/2011
KFAY: 72/2000
MAY 25:
KGSO: 70/2019
KRDU: 71/2019
KFAY: 71/2019
MAY 26:
KGSO: 70/2019
KRDU: 73/2011
KFAY: 75/2004
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...DANCO/MWS
AVIATION...CA
CLIMATE...RAH
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