131
FXUS62 KRAH 031820
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
220 PM EDT THU SEP 3 2026
WHAT HAS CHANGED
* AN AIR QUALITY ALERT HAS BEEN ISSUED FOR THE TRIAD COUNTIES,
INCLUDING FORSYTH, GUILFORD, ALAMANCE, DAVIDSON AND RANDOLPH
COUNTIES UNTIL 8 PM THIS EVENING AFTER COLLABORATION WITH THE
FORSYTH COUNTY OFFICE OF ENVIRONMENTAL ASSISTANCE AND
PROTECTION IN WINSTON-SALEM.
* ANOTHER HEAT ADVISORY HAS BEEN ISSUED FOR FRIDAY FROM 11 AM
UNTIL 8 PM.
* INCREASING CHANCES FOR POST-FRONTAL SHOWERS ON SUNDAY, MAINLY
ACROSS THE WEST.
KEY MESSAGES
AS OF 215 PM THURSDAY...
1) A HEAT ADVISORY HAS BEEN ISSUED FOR FRIDAY 11 AM UNTIL 8 PM.
ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO PERSIST INTO SAT
AT LEAST FOR A PORTION OF CENTRAL NC.
2) STORM CHANCES WILL INCREASE ON FRIDAY AND PEAK ON SATURDAY
AHEAD OF A COLD FRONT. THIS WILL BE FOLLOWED BY DRIER WEATHER
AND A RETURN TO MORE SEASONAL TEMPERATURES EARLY NEXT WEEK.
DISCUSSION
AS OF 215 PM THURSDAY...
KEY MESSAGE 1... A HEAT ADVISORY HAS BEEN ISSUED FOR FRIDAY 11
AM UNTIL 8 PM. ANOMALOUSLY HOT TEMPERATURES ARE EXPECTED TO
PERSIST INTO SAT AT LEAST FOR A PORTION OF CENTRAL NC.
A LOWER MID-LATITUDE/SUB-TROPICAL RIDGE CENTERED OVER THE SRN
APPALACHIANS, OBSERVED AROUND 595 DAM AND 324 DAM IN THE 500-700
MB LAYER THIS MORNING, 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
CONVECTIVE CHANCES CONTINUE TO DECREASE THROUGHOUT MID-AFTEROON
TO PROVIDE ANY RELIEF FROM DANGEROUS HEAT.
MEAN MIXING RATIOS AND SURFACE DEWPOINTS ARE FORECAST TO
INCREASE SLIGHTLY ON 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 FROM THE NRN
SANDHILLS TO THE NE PIEDMONT AND COASTAL PLAIN. AS SUCH, A HEAT
ADVISORY HAS BEEN ISSUED FOR FRI (11 AM UNTIL 8 PM). THE HEAT
ADVISORY FOR TODAY, THURS, REMAINS IN EFFECT UNTIL 8 PM THIS
EVENING. ADDITIONAL HEAT ADVISORIES WILL LIKELY BE NEEDED, BUT
PERHAPS OVER A SMALLER AREA, ON SAT.
KEY MESSAGE 2... STORM CHANCES WILL INCREASE ON FRIDAY AND PEAK
ON SATURDAY AHEAD OF A COLD FRONT. THIS WILL BE FOLLOWED BY
DRIER WEATHER AND A RETURN TO MORE SEASONAL TEMPERATURES EARLY
NEXT WEEK.
MID TO UPPER-LEVEL NORTHWEST FLOW WILL INCREASE FRIDAY AND PEAK
ON SATURDAY. THE ANOMALOUS RIDGE WILL GRADUALLY BE SHUNTED
WESTWARD BY SATURDAY AS AN EAST COAST TROUGH BECOMES MORE
DOMINANT. THIS PATTERN SHIFT WILL INCREASINGLY FAVOR SHOWERS AND
THUNDERSTORMS THROUGH THE FIRST HALF OF THE WEEKEND.
FRIDAY: THE DANGEROUS HEAT DOME WILL REMAIN IN PLACE. MODEL
GUIDANCE INDICATES A MORNING DISTURBANCE TRACKING ACROSS THE
GREAT LAKES AND NORTHERN MID-ATLANTIC, WHICH MAY SUSTAIN ONGOING
EARLY-DAY CONVECTION. BY THE AFTERNOON AND EVENING, SEVERAL 12Z
HREF MEMBERS INITIATE NEW STORMS ALONG THE SOUTHERN VIRGINIA
BORDER, SPREADING INTO NORTHERN PORTIONS OF CENTRAL AND EASTERN
NORTH CAROLINA. ORGANIZATION MAY BE ENHANCED BY AN UPSTREAM
DISTURBANCE, A SURFACE TROUGH, OR LINGERING OUTFLOW BOUNDARIES.
THESE STORMS COULD GROW UPSCALE AS THEY TRACK EAST-SOUTHEAST
INTO THE PIEDMONT AND COASTAL PLAIN THROUGH THE MID-TO-LATE
EVENING. DAMAGING WINDS AND LARGE HAIL ARE THE PRIMARY HAZARDS.
A SLIGHT RISK FOR SEVERE WEATHER REMAINS IN PLACE FOR MUCH OF
THE NORTHERN PIEDMONT, THE TRIANGLE, AND THE CENTRAL/NORTHERN
COASTAL PLAIN, WITH A MARGINAL RISK COVERING THE REMAINING
SOUTHWESTERN AND WESTERN AREAS.
SATURDAY: THE GREATEST COVERAGE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED ON SATURDAY. A WELL-DEFINED, CONVECTIVELY-INDUCED MID-
LEVEL DISTURBANCE OVER THE LOWER OHIO VALLEY WILL INTERACT WITH
A BACKDOOR COLD FRONT SLIDING SOUTH THROUGH THE MID-ATLANTIC.
DEEP-LAYER SHEAR WILL INCREASE COMPARED TO FRIDAY AS THE EAST
COAST TROUGH DIGS FURTHER WEST, SUPPORTING MULTICELL STORMS
CAPABLE OF PRODUCING DAMAGING WIND GUSTS AND LARGE HAIL. A
SLIGHT RISK REMAINS IN PLACE FOR ALL OF CENTRAL NORTH CAROLINA.
AHEAD OF THIS CONVECTIVE ACTIVITY, EXPECT ANOTHER DAY OF
DANGEROUS HEAT.
SUNDAY & BEYOND: THE COLD FRONT IS EXPECTED TO PUSH THROUGH BY
SUNDAY MORNING. WHILE POST-FRONTAL STRATUS, LINGERING MOISTURE,
AND UPSLOPE FLOW COULD SUPPORT ISOLATED TO SCATTERED SHOWERS
ACROSS THE WESTERN PIEDMONT, THE SEVERE THREAT WILL HAVE GREATLY
DIMINISHED. DRIER AIR AND MORE SEASONAL TEMPERATURES WILL
ARRIVE IN TIME FOR LABOR DAY AND PERSIST INTO TUESDAY.
UNFORTUNATELY, THIS REPRIEVE FROM THE HEAT WILL BE BRIEF, WITH
HIGH TEMPERATURES EXPECTED TO REBOUND INTO THE LOW-TO-MID 90S BY
WEDNESDAY AND THURSDAY. WHILE SOME ENSEMBLE GUIDANCE HINTS AT
ANOTHER FRONTAL PASSAGE AND A RENEWED CHANCE FOR PRECIPITATION
LATE NEXT WEEK, CONFIDENCE REMAINS LOW AT THIS RANGE.
AVIATION /18Z THURSDAY THROUGH TUESDAY/
AS OF 150 PM THURSDAY...
PREVAILING VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE
24 HOUR TAF PERIOD. AN ISOLATED SPRINKLE CAN'T BE RULED OUT
AROUND RDU, FAY OR RWI TODAY, BUT WIDESPREAD OR EVEN SCATTERED
DEEP CONVECTION IS NOT EXPECTED. MOSTLY SHALLOW CONVECTION
CONTINUING TO DEVELOP ALONG THE VA MOUNTAINS MAY CONTINUE BUILD
TO SHIFT SOUTH TO SOUTHEAST. LATEST TIME-OF-ARRIVAL CALCULATIONS
AND AVAILABLE HI-RES GUIDANCE KEEPS THESE SHOWERS/STORMS NORTH
OF THE FORECAST AREA UNTIL AFTER SUNSET, WITH AN EXPECTED
WEAKENING TREND 1-2 HOURS THEREAFTER. WITH PROBS OF ANY
RESTRICTIONS FROM CONVECTION DECREASING AROUND RWI, HAVE OPTED
TO REMOVE THE PROB30 TO LATER ASSESS WITH THE 00Z TAFS.
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 WITH
ACCOMPANYING POST-FRONTAL STRATUS.
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 UNTIL 8 PM EDT THIS EVENING FOR NCZ007>011-
023>028-040>043-074>078-083>086-088-089.
HEAT ADVISORY FROM 11 AM TO 8 PM EDT FRIDAY FOR NCZ011-024>028-
040>043-074>078-083>086-088-089.
AIR QUALITY ALERT UNTIL 8 PM EDT THIS EVENING FOR NCZ021>023-
038-039.
DISCUSSION...MWS/AS/AK
AVIATION...AS/MWS
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