301
FXUS62 KRAH 011802
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
202 PM EDT TUE SEP 1 2026
WHAT HAS CHANGED
* A HEAT ADVISORY HAS BEEN ISSUED FOR WEDNESDAY FROM 11 AM UNTIL
8 PM. HEAT INDEX VALUES OF UP TO 107 DEGREES SHOULD BE
EXPECTED WITHIN THE ADVISORY AREA.
* SPC HAS INTRODUCED A MARGINAL TO SLIGHT RISK OF SEVERE STORMS
IN OUR NE ZONES THU AND FRI.
* SLIGHT TREND IN THE GUIDANCE TOWARD MILDER TEMPERATURES POST-
FRONTAL SUNDAY TO TUESDAY.
KEY MESSAGES
AS OF 200 PM TUESDAY...
1) A HEAT ADVISORY HAS BEEN ISSUED FOR WEDNESDAY 11 AM UNTIL 8
PM. ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO PERSIST INTO
FRIDAY.
2) LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY TRENDS COOLER
ALONG WITH HIGHEST THUNDERSTORM CHANCES FRIDAY AND SATURDAY.
DISCUSSION
AS OF 200 PM TUESDAY...
KEY MESSAGE 1... A HEAT ADVISORY HAS BEEN ISSUED FOR WEDNESDAY
11 AM UNTIL 8 PM. ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO
PERSIST INTO FRIDAY.
A DEEP SUBTROPICAL RIDGE OF AROUND 596 DAM SLIDING EAST INTO
THE TN VALLEY IN THE 12Z H5 RAOBS THIS MORNING IS FORECAST TO
WOBBLE GRADUALLY EASTWARD AND STRETCH OVER THE CAROLINAS BY
THURS MORNING. HIGHLY ANOMALOUS H850 TEMPERATURES (AT-OR-ABOVE
THE 99.5 PERCENTILE) INITIALLY DIRECTED OVER THE OHIO VALLEY AND
LOWER GREAT LAKES TODAY, WILL GRADUALLY WARM TO AROUND 20-22C
AND SLOWLY BE DIRECTED OVER THE SOUTHERN MID-ATLANTIC WED
THROUGH FRI. THIS PATTERN IS HIGHLY FAVORABLE FOR AN EARLY
SEPTEMBER HEAT WAVE WITH MINIMAL CONVECTIVE CHANCES DUE TO
INFLUENCE FROM THE STRONG SUBTROPICAL RIDGE.
LOW-LVL THICKNESSES AND DIABATIC TECHNIQUES LINE UP WITH
STATISTICAL GUIDANCE AND SUPPORTS WIDESPREAD MID/UPPER 90S
CONTINUING THROUGH FRI. A FEW LOCATIONS MAY REACH TRIPLE DIGIT
AIR TEMPERATURES, BUT WIDESPREAD GREATER THAN 100 DEGREES IS NOT
EXPECTED. HEAT INDEX VALUES SOUTH AND EAST OF RALEIGH ARE
LIKELY TO REACH IF NOT ECLIPSE 105 DEGREES FOR SEVERAL HOURS DUE
TO BETTER LOW-LVL MOISTURE IN PLACE. ADDITIVELY, WEAK SURFACE
WINDS AND ABUNDANT SUNSHINE WILL COMPOUND THE RISK FOR HEAT
RELATED ILLNESSES, ESPECIALLY INDIVIDUALS SENSITIVE TO THE HEAT
OR PARTAKE IN STRENUOUS OUTDOOR ACTIVITIES IN THE AFTERNOON
DURING PEAK HEATING. ANYONE WITHOUT EFFECTIVE OVERNIGHT COOLING
IS AT GREATER RISK FOR HEAT ILLNESS AS SEVERAL DAYS WITH
ANOMALOUSLY WARM OVERNIGHT LOW IN THE UPPER 70S WILL PROVIDE
MINIMAL RELIEF FROM HOT AFTERNOON TEMPERATURES AND HUMID
CONDITIONS. AS SUCH, A HEAT ADVISORY HAS BEEN ISSUED FOR WED (11
AM UNTIL 8 PM). THIS IS ONLY THE 3RD HEAT ADVISORY ISSUED IN
THE MONTH OF SEPTEMBER BY THE RALEIGH OFFICE AND THE FIRST SINCE
2020. ADDITIONAL HEAT ADVISORIES WILL LIKELY BE NEEDED THROUGH
FRI.
INCREASING CONVECTIVE CHANCES, AN APPROACHING COLD FRONT AND
NORTHEAST FLOW IN ITS WAKE SHOULD PUT AN END TO THE DANGEROUS
HEAT BY SUN.
KEY MESSAGE 2...LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY
TRENDS COOLER ALONG WITH HIGHEST THUNDERSTORM CHANCES FRIDAY
AND SATURDAY.
ENSEMBLE AND DETERMINISTIC GUIDANCE CONTINUES TO SHOW A GRADUAL
WESTWARD SHIFT OF THE ANOMALOUSLY STRONG UPPER-RIDGE. COME
THURSDAY, IT IS DIRECTLY OVERHEAD OVER THE SOUTHERN
APPALACHIANS, BUT SLIDING WEST TOWARD THE CENTRAL AND SOUTHERN
PLAINS THIS WEEKEND AND EARLY NEXT WEEK. WE CONTINUE TO WATCH AS
THAT HAPPENS A MORE NORTHWESTERLY FLOW DEVELOPING, ESPECIALLY
FRIDAY ONWARD. THIS PATTERN SHIFT CONTINUES TO SUPPORT A COLD
FRONT APPROACHING LATE FRIDAY BUT ESPECIALLY SATURDAY, BEFORE
MOVING THROUGH FOR SUNDAY.
THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS IS FAVORED LATE
FRIDAY AND SATURDAY DURING PEAK AFTERNOON AND EVENING HOURS,
PRE-FRONTAL AND ALONG THE FRONT. GIVEN THE ATMOSPHERIC SETUP,
CONDITIONS APPEAR FAVORABLE FOR LOCALLY DAMAGING WINDS. SPC HAS
INTRODUCED A DAY 4 SLIGHT RISK ACROSS OUR NE COUNTIES FRIDAY.
ADD TO THAT, ML/AI GUIDANCE ALSO FAVORS A SEVERE RISK ON
SATURDAY, THOUGH ENSEMBLES AND DETERMINISTIC SOLUTIONS DIFFER ON
THE FRONTAL POSITION AND SPEED. SOMETHING THAT IS ALSO NEW IS
THAT SPC DID INCLUDE A VERY SMALL AREA OF A MARGINAL RISK
THURSDAY EVENING ACROSS OUR NORTHERN COASTAL PLAIN COUNTIES.
SOME DETERMINISTIC SCENARIOS AND NEARLY HALF OF THE EPS MEMBERS
SHOW A MID-LEVEL DISTURBANCE RIDING THE RIDGE TO FAVOR SOME LOW-
END STORM CHANCES IN OUR NE THURSDAY EVENING.
THERE IS A SMALL BUT NOTICEABLE SIGNAL THAT ONCE THE FRONT
MOVES THROUGH, WE MAY NOT COOL OFF AS MUCH AS ORIGINALLY
ADVERTISED. SOME ENSEMBLE AND DETERMINISTIC SOLUTIONS HANG THE
FRONT JUST TO OUR SOUTH AND WEST INTO EARLY NEXT WEEK, RESULTING
IN HIGHS IN THE MIDDLE TO UPPER 80S AND PERHAPS NOT AS LESS
HUMID. HOW THAT WILL TREND IN THE COMING DAYS REMAINS TO BE
SEEN, BUT NEVERTHELESS IT SHOULD BE DRIER WITH JUST ISOLATED
AFTERNOON STORMS THROUGH THE LABOR DAY HOLIDAY.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
AS OF 130 PM TUESDAY...
PREVAILING VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE
24 HOUR TAF PERIOD. ISOLATED SHOWERS AND PERHAPS INFREQUENT
LIGHTNING WILL BE POSSIBLE FROM RWI TO FAY AND PERHAPS AS FAR
NORTH AS RDU WITHIN AN AXIS OF HOT AND HUMID CONDITIONS. LIMITED
COVERAGE AND DURATION OF STORMS PRECLUDES THE NEED FOR PROB30S
AT THIS TIME, BUT FUTURE AMENDMENTS MAY BE NEEDED. SHOWER
ACTIVITY SHOULD QUICKLY ABATE AROUND SUNSET WITH LOSS OF DIURNAL
HEATING.
OUTLOOK: AFTERNOON CONVECTION WILL LIKELY BE SUPPRESSED THROUGH
THURSDAY WITH MOSTLY FAIR WEATHER CU AROUND 5-8 KFT DURING THE
AFTERNOON HOURS. LIGHT AND VARIABLE WINDS PERSIST GENERALLY OUT
OF THE SOUTHWEST. SHOWER/STORM CHANCES INCREASE FRI AND
ESPECIALLY SAT AS THE RIDGE BREAKS DOWN AND A COLD FRONT
APPROACHES FROM THE NORTH-NORTHEAST SAT INTO SUN.
RAH WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY FROM 11 AM TO 8 PM EDT WEDNESDAY FOR NCZ010-011-
024>028-040>043-075>078-084>086-088-089.
DISCUSSION...AS/AK
AVIATION...AS
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