344
FXUS62 KRAH 030622
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
222 AM EDT THU SEP 3 2026
WHAT HAS CHANGED
* RAIN-COOLED AIR FROM NERN NC THROUGH CNTL AND NRN VA WILL SUPPORT
THE DEVELOPMENT AND MAINTENANCE OF PATCHES OF FOG AND STRATUS THIS
MORNING, INCLUDING AT RWI WHERE SOILS WERE LOCALLY SATURATED BY
0.5" OF RAIN WED EVENING.
KEY MESSAGES
AS OF 215 PM WEDNESDAY...
1) A HEAT ADVISORY HAS BEEN ISSUED FOR THURSDAY 11 AM UNTIL 8
PM. ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO PERSIST INTO
FRIDAY AND PERHAPS LINGER ACROSS THE SOUTH INTO SAT.
2) A WEAKNESS IN THE ANOMALOUS RIDGE WILL FAVOR ISOLATED TO
SCATTERED SEVERE STORMS THURSDAY EVENING.
3) LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY TRENDS SOMEWHAT
MORE COMFORTABLE, WITH FRIDAY AND SATURDAY SEEING OUR GREATEST
STORM CHANCES.
DISCUSSION
AS OF 215 PM WEDNESDAY...
KEY MESSAGE 1... A HEAT ADVISORY HAS BEEN ISSUED FOR THURSDAY
11 AM UNTIL 8 PM. ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO
PERSIST INTO FRIDAY AND PERHAPS LINGER ACROSS THE SOUTH INTO
SAT.
A DEEP SUBTROPICAL RIDGE OF AROUND 595 DAM IS FIRMLY
ESTABLISHED OVER THE TN VALLEY IN THE 12Z H5 RAOBS THIS MORNING
AND IS FORECAST TO MORE-OR-LESS REMAIN IN PLACE WHILE ELONGATING
ACROSS THE CAROLINAS FRI INTO FRI NIGHT. HIGHLY ANOMALOUS H850
TEMPERATURES (AT- OR-ABOVE THE 99.5 PERCENTILE) CURRENTLY IN
PLACE OVER THE OHIO VALLEY AND SOUTHERN/MIDDLE APPALACHIANS,
WILL GRADUALLY SHIFT SOUTH AND INTO THE CAROLINAS 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 CONTINUE TO LINE UP
WITH STATISTICAL GUIDANCE AND SUPPORTS WIDESPREAD 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 ACROSS THE FORECAST AREA ARE
EXPECTED TO ECLIPSE 100 DEGREES ON THURSDAY WITH 102 TO 108
EXPECTED FOR CONSECUTIVE HOURS SOUTH AND EAST OF THE TRIAD.
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 LOWS IN
THE MID/UPPER 70S WILL PROVIDE MINIMAL RELIEF FROM HOT
AFTERNOON TEMPERATURES AND HUMID CONDITIONS. AS SUCH, A HEAT
ADVISORY HAS BEEN ISSUED FOR THURS (11 AM UNTIL 8 PM) AND HAS
BEEN EXPANDED WESTWARD COMPARATIVE TO THE ADVISORY CURRENTLY IN
PLACE THROUGH THIS EVENING. ADDITIONAL HEAT ADVISORIES WILL
LIKELY BE NEEDED THROUGH AT LEAST FRI.
INCREASING CONVECTIVE CHANCES, APPROACHING COLD FRONT AND
NORTHEAST FLOW IN ITS WAKE SHOULD PUT AN END TO THE HEAT BY SUN.
KEY MESSAGE 2...A WEAKNESS IN THE ANOMALOUS RIDGE WILL FAVOR
ISOLATED TO SCATTERED SEVERE STORMS THURSDAY EVENING.
THE ANOMALOUSLY STRONG RIDGE CENTERED OVER THE SOUTHERN
APPALACHIANS THURSDAY CONTINUES TO REMAIN IN PLACE. HOWEVER, A
SLIGHT WEAKNESS IN THE RIDGE PATTERN TAKES SHAPE, WITH MODEL
GUIDANCE INCREASINGLY SHOWING A TREND TOWARD SOME LATE DAY TO
LATE EVENING ISOLATED TO SCATTERED CONVECTION ACROSS OUR
NORTHEAST ZONES.
THE GFS CONTINUES TO SHOW A WEAK DISTURBANCE SLIDING DOWN
AROUND THE NORTHEAST PART OF THE RIDGE, OUT OF WV/VA AND
CLIPPING PORTIONS OF THE NORTHEAST PIEDMONT AND COASTAL PLAIN OF
CENTRAL NC LATE IN THE DAY. STORM COVERAGE APPEARS ISOLATED TO
SCATTERED, PERHAPS ENHANCED ALONG SUBTLE SURFACE BOUNDARIES. SPC
CURRENTLY HAS A MARGINAL RISK OF SEVERE STORMS OVER OUR FAR
NORTHEAST PIEDMONT AND NORTHERN COASTAL PLAIN. TIMING-WISE, THIS
APPEARS A LATE-DAY EVENT, ROUGHLY IN THE 5PM TO 11PM TIME
FRAME. INSTABILITY IS SUFFICIENT BUT SHEAR IS MARGINAL AROUND
25-KT OF DEEP-LAYER FLOW. HOWEVER, CERTAINLY COULD SEE ISOLATED
DAMAGING WINDS AS THE PRIMARY THREAT GIVEN IMPRESSIVE DCAPE SEEN
IN POINT SOUNDINGS OF 1000-1400 J/KG.
KEY MESSAGE 3...LABOR DAY WEEKEND THROUGH MONDAY GRADUALLY
TRENDS SOMEWHAT MORE COMFORTABLE, WITH FRIDAY AND SATURDAY
SEEING OUR GREATEST STORM CHANCES.
OVERALL, THE EXTENDED FORECAST HAS NOT CHANGED DRASTICALLY FROM
THE PAST 24 HOURS OR SO FOR CENTRAL NC. WE ARE CONTINUING TO
TRACK A COLD FRONT THAT WILL APPROACH LATE FRIDAY AND SATURDAY,
PUSHING THROUGH EARLY SUNDAY FROM THE NE AS SOMEWHAT COOLER HIGH
PRESSURE BUILDS DOWN FROM THE MID-ATLANTIC STATES. ENSEMBLE
BASED SOLUTIONS CONTINUE TO FAVOR FRIDAY AND SATURDAY AS OUR
BEST COVERAGE OF STORMS, WITH PERHAPS SATURDAY MORE WIDESPREAD,
THOUGH THAT WILL ULTIMATELY DEPEND ON THE POSITION OF THE FRONT.
DURING THESE TWO DAYS, SPC HAS A SLIGHT RISK OF SEVERE STORMS
DURING THE AFTERNOON INTO THE LATE EVENING HOURS, FOR OUR
CENTRAL AND NORTHERN AREAS FRIDAY AND CENTRAL TO SOUTHERN AREAS
SATURDAY. BASED ON AI/ML GUIDANCE, THIS SEVERE TREND HAS BEEN
INCREASING, WITH A FOCUS ON DAMAGING WINDS AS THE PRIMARY
THREAT. THIS APPEARS TO BE DRIVEN IN LARGE PART BY 30-KT OF
DEEP-LAYER SHEAR AND INSTABILITY.
MUCH OF THE ENSEMBLE SCENARIOS CONTINUE TO INDICATE THE FRONT
PUSHING THROUGH SUNDAY MORNING OR EARLY AFTERNOON, THEREBY
SHUNTING MOST OF THE CONVECTION TO OUR WEST AND SOUTH. HOWEVER,
LINGERING ISOLATED TO SCATTERED STORMS COULD LINGER OVER THE
WESTERN AND SOUTHERN PIEDMONT. INTERESTINGLY, A THIRD OF THE EPS
ENSEMBLE MEMBERS SHOW THE FRONT HUNG UP OVER THE AREA, THEREBY
KEEPING STORMS IN THE FORECAST. THIS SCENARIO IS WORTH
CONSIDERING BUT FOR NOW THE CONSENSUS IS DRIER WITH HIGHS AROUND
THE MIDDLE 80S SUNDAY THROUGH TUESDAY. LOWER HUMIDITY IS
FAVORED WITH COOL HIGH PRESSURE NOSING DOWN INTO THE AREA.
THE STRONG ANOMALOUS RIDGE APPEARS TO BUILD BACK IN AFTER LABOR
DAY, FAVORING A RETURN TO THE 90S BY MIDWEEK. STORM CHANCES
APPEAR ISOLATED AT BEST DURING THIS TIME FRAME.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 220 AM THURSDAY...
RAIN-COOLED AIR FROM NERN NC THROUGH CNTL AND NRN VA WILL SUPPORT
THE DEVELOPMENT AND MAINTENANCE OF PATCHES OF FOG AND STRATUS THIS
MORNING, INCLUDING AT RWI WHERE SOILS WERE LOCALLY SATURATED BY 0.5"
OF RAIN WED EVENING. SOME MAY DEVELOP AS FAR SOUTHWEST AS RDU AROUND
12Z, 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 STRATUS ESPECIALLY OVER THE ERN
CAROLINAS FRI MORNING, INCLUDING AS FAR NW AS 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...AS/AK
AVIATION...MWS
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