673
FXUS62 KRAH 031116
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
716 AM EDT THU SEP 3 2026
WHAT HAS CHANGED
* RAIN-COOLED AIR FROM NERN NC THROUGH CNTL AND NRN VA WILL SUPPORT
THE MAINTENANCE OF PATCHES TO AREAS OF FOG AND LOW STRATUS THIS
MORNING, INCLUDING AT RWI WHERE SOILS WERE LOCALLY SATURATED BY
0.5" OF RAIN WED EVENING.
KEY MESSAGES
AS OF 325 AM THURSDAY...
1) A HEAT ADVISORY REMAINS IN EFFECT TODAY FROM 11 AM TO 8 PM FOR
ALL BUT THE FAR WRN/SRN PIEDMONT. ANOTHER WILL LIKELY BE NEEDED FOR
FRI.
2) SCATTERED STORMS WILL FOCUS ACROSS THE FAR NRN/NE PIEDMONT AND
NRN COASTAL PLAIN THE NEXT COUPLE OF AFTERNOONS-EVENINGS, WITH AN
ACCOMPANYING RISK OF DAMAGING, MULTI-CELL DOWNBURSTS.
3) A COLD FRONT WILL PASS THROUGH THE REGION SATURDAY NIGHT INTO
SUNDAY, BRINGING THE BEST CHANCE OF RAIN ON SATURDAY FOLLOWED BY A
COOL DOWN CLOSER TO NORMAL.
DISCUSSION
AS OF 325 AM THURSDAY...
KEY MESSAGE 1... A HEAT ADVISORY REMAINS IN EFFECT TODAY FROM 11 AM
TO 8 PM FOR ALL BUT THE FAR WRN/SRN PIEDMONT. ANOTHER WILL LIKELY BE
NEEDED FOR FRI.
A LOWER MID-LATITUDE/SUB-TROPICAL RIDGE CENTERED OVER THE SRN
APPALACHIANS, OBSERVED AT 595 DAM AND 324 DAM IN THE 500-700 MB
LAYER ON WED, WILL PERSIST IN A FAVORABLE LOCATION FOR EXCESSIVE
HEAT IN CNTL NC FOR THE NEXT COUPLE OF DAYS.
PERSISTENCE SURFACE TEMPERATURES, TO 1-2 F HOTTER ONES ESPECIALLY
OVER THE NRN PIEDMONT, WILL LIKELY RESULT TODAY AND COMBINE WITH
MIXED/AFTERNOON DEWPOINTS IN THE UPR 60S TO LWR 70S. RELATED HEAT
INDEX VALUES WILL RANGE BETWEEN 100-105 F OVER THE NW PIEDMONT TO
MOSTLY 105-108 F IN THE ADVISORY AREA. ANY CONVECTION AND OUTFLOW
WILL LIKELY NOT DEVELOP UNTIL LATE AFTERNOON-EVENING, WITH LIMITED
RELIEF FROM THE EXCESSIVE HEAT.
MEAN MIXING RATIOS AND SURFACE DEWPOINTS ARE FORECAST TO INCREASE BY
FRI, WHEN MIXED/AFTERNOON DEWPOINTS ARE LIKELY TO BE IN THE LWR 70S.
THAT UPTICK IN DEWPOINTS WILL LIKELY YIELD THE HIGHEST HEAT INDEX
VALUES OF THIS STRETCH ON FRI, WHEN VALUES NEAR 110 F WILL BE
POSSIBLE AT THE MOST RELIABLE OBSERVATION SITES FROM THE NRN
SANDHILLS TO THE NE PIEDMONT AND COASTAL PLAIN (IE. NOT IXA AND CTZ,
WHERE VALUES AROUND 115 F WILL PROBABLY RESULT FROM
UNREPRESENTATIVE/HIGH-BIASED SURFACE DEWPOINTS AT THOSE SITES).
KEY MESSAGE 2... SCATTERED STORMS WILL FOCUS ACROSS THE FAR NRN/NE
PIEDMONT AND NRN COASTAL PLAIN THE NEXT COUPLE OF AFTERNOONS-
EVENINGS, WITH AN ACCOMPANYING RISK OF DAMAGING, MULTI-CELL
DOWNBURSTS.
NWLY FLOW ALOFT, AROUND THE AFOREMENTIONED RIDGE CENTERED OVER THE
SRN APPALACHIANS, WILL GRADUALLY STRENGTHEN AND BE ACCOMPANIED BY
WEAKLY FALLING HEIGHTS AND COOLING THROUGH THE MID-LEVELS OVER THE
SRN MIDDLE ATLANTIC BY FRI-FRI NIGHT, AS A CYCLONE PROGRESSES SEWD
ACROSS SRN QC.
MEANWHILE AT THE SURFACE, A LEE/PRE-FRONTAL TROUGH WILL REMAIN OVER
VA/NC, PRECEDING BOTH A SYNOPTIC COLD FRONT AND COMPOSITE OUTFLOW
THAT WILL GRADUALLY SETTLE SWD FROM THE LWR GREAT LAKES AND NRN
MIDDLE ATLANTIC THIS MORNING. WHILE BOTH WILL PROBABLY REMAIN TO THE
NORTH OF CNTL NC UNTIL SAT, OTHER AGGREGATE OUTFLOWS WILL PROBABLY
DEVELOP SWD ACROSS VA AND INTO THE NRN PIEDMONT AND NRN COASTAL
PLAIN OF NC LATER THIS AFTERNOON-EVENING AND MORE-SO FRI AFTERNOON-
EVENING, THE LATTER WHEN OVERALL CONVECTIVE COVERAGE OVER THE SRN
MIDDLE ATLANTIC WILL PROBABLY BE GREATER OF THE TWO DAYS. WHILE THE
STRONGEST NWLY FLOW WILL REMAIN ACROSS THE NRN MIDDLE ATLANTIC
THROUGH THE PERIOD, WHERE RELATIVELY GREATEST SEVERE POTENTIAL WILL
EXIST, CONTINUED HIGH DCAPE OF 1000-1500 J/KG WILL SUPPORT A RISK OF
DAMAGING DOWNBURSTS FROM PULSE/MULTICELLS TODAY. THE THERMODYNAMIC
ENVIRONMENT WILL BE SIMILAR ON FRI, WITH A SLIGHTLY GREATER
SEVERE/WIND RISK FROM MULTICELL CLUSTERS ORGANIZED BY AN INCREASE IN
NWLY, MID-LEVEL FLOW TO 15-25 KTS OVER NRN AND NERN NC BY LATE FRI-
FRI NIGHT.
KEY MESSAGE 3... A COLD FRONT WILL PASS THROUGH THE REGION SATURDAY
NIGHT INTO SUNDAY, BRINGING THE BEST CHANCE OF RAIN ON SATURDAY
FOLLOWED BY A COOL DOWN CLOSER TO NORMAL.
SATURDAY SHOULD BE THE LAST HOT DAY OF THIS STRETCH, WITH HIGH
TEMPERATURES IN THE 90S AND HEAT INDICES GENERALLY EXPECTED IN THE
MID 90S TO MID 100S IN THE WARM SECTOR AHEAD OF AN APPROACHING COLD
FRONT. THIS SHOULD PROVIDE PLENTY OF INSTABILITY FOR STORM
FORMATION, WITH MODELS SHOWING AROUND 1000-2000 J/KG OF CAPE
SATURDAY AFTERNOON. THERE ALSO LOOKS TO BE AROUND 25-35 KTS OF
SHEAR, TO ALLOW FOR STORMS TO SUSTAIN AND CREATE A POTENTIAL SEVERE
STORM THREAT. DEPENDING ON THE TIMING OF THE RAIN, THE MAIN THREAT
SHOULD BE STRONG TO SEVERE WINDS AND WATER-LOADED DOWNBURSTS WITHIN
CLUSTERS OF STORMS SATURDAY AFTERNOON INTO THE EVENING. MOST MODEL
GUIDANCE IS SUGGESTING UP TO AN INCH OF RAIN MAY BE POSSIBLE ON
SATURDAY, WITH ISOLATED HIGHER AMOUNTS POSSIBLE. SOME GUIDANCE IS
STILL SUGGESTING THAT SOME RAIN MAY LINGER INTO SUNDAY DEPENDING ON
THE TIMING OF THE FRONT, HOWEVER THE CHANCE OF THIS SEEMS TO BE
DECREASING.
THE COLD FRONT SHOULD MOVE THROUGH THE REGION SOMETIME SATURDAY
NIGHT INTO SUNDAY MORNING WHICH WILL USHER IN COOLER AND DRIER AIR
TO THE REGION AS HIGH PRESSURE BUILDS IN. HIGH TEMPERATURES SHOULD
RETURN TO THE 80S FROM SUNDAY THROUGH TUESDAY, BEFORE POTENTIALLY
RETURNING TO THE 90S MIDWEEK. THE CHANCE OF RAIN DURING THIS PERIOD
WILL BE GENERALLY LOW EACH DAY.
AVIATION /12Z THURSDAY THROUGH MONDAY/
AS OF 715 AM THURSDAY...
RAIN-COOLED AIR FROM NERN NC THROUGH CNTL AND NRN VA WILL SUPPORT
THE MAINTENANCE OF PATCHES TO AREAS OF FOG AND LOW STRATUS THIS
MORNING, INCLUDING AT RWI WHERE SOILS WERE LOCALLY SATURATED BY 0.5"
OF RAIN WED EVENING. A FEW PATCHES MAY DEVELOP AS FAR SOUTHWEST AS
RDU THROUGH 13-14Z, THOUGH WITH LOWER PROBABILITY OF OCCURRENCE THAN
POINTS NEWD. A 20-30 PERCENT CHANCE OF STORMS WITH GUSTY SURFACE
WINDS WILL EXIST MAINLY AT RWI BETWEEN 22Z-03Z, MUCH LIKE THOSE OF
WED.
OUTLOOK: DEEPENING/RICHER LOW-LEVEL MOISTURE BY FRI WILL FAVOR THE
DEVELOPMENT OF AREAS OF FOG AND LOW STRATUS ESPECIALLY OVER THE ERN
CAROLINAS FRI MORNING, INCLUDING NEAR AND PROBABLY JUST SOUTHEAST OF
FAY. SCATTERED CONVECTION WILL AGAIN FOCUS FROM NEAR RWI AND
POSSIBLY SLIGHTLY SWD ACROSS THE PIEDMONT FRI AFTERNOON AND EVENING,
THEN THROUGHOUT CNTL NC WITH THE APPROACH AND PASSAGE OF A BACKDOOR
COLD FRONT SAT AFTERNOON-EVENING.
CLIMATE
RECORDS WITHIN REACH THIS FORECAST PERIOD:
RECORD HIGH TEMPERATURES:
SEPTEMBER 3: KRDU: 99/2010 KFAY: 101/2010
SEPTEMBER 4: KRDU: 100/1925 KFAY: 100/1944
SEPTEMBER 5: KGSO: 97/1954 KRDU: 98/2023 KFAY: 99/1932
RECORD HIGH MINIMUM TEMPERATURES:
SEPTEMBER 3: KGSO: 73/2020 KRDU: 78/1933 KFAY: 77/2020
SEPTEMBER 4: KGSO: 72/2018 KRDU: 74/1921 KFAY: 75/2020
SEPTEMBER 5: KGSO: 73/2018 KRDU: 74/2012 KFAY: 74/1935
RAH WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR NCZ007>011-023>028-040>043-074>078-083>086-088-089.
DISCUSSION...MWS/LBH
AVIATION...MWS
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