430
FXUS62 KRAH 170532
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
130 AM EDT FRI JUL 17 2026
WHAT HAS CHANGED
* AIR QUALITY ALERTS IN EFFECT FOR THE TRIANGLE AND TRIAD.
* INCREASED CHANCES OF SEVERE WEATHER LATER THIS WEEKEND.
KEY MESSAGES
AS OF 130 AM FRIDAY...
1) AIR QUALITY ALERTS IN EFFECT FOR THE TRIANGLE AND TRIAD.
2) HOT TEMPERATURES AND POTENTIALLY DANGEROUS HEAT EXPECTED
INTO SATURDAY.
3) BECOMING UNSETTLED THIS WEEKEND INTO EARLY NEXT WEEK WITH
INCREASED CHANCES OF SEVERE STORMS SATURDAY AND ESPECIALLY SUNDAY.
DISCUSSION
AS OF 130 AM FRIDAY...
KEY MESSAGE 1... AIR QUALITY ALERTS IN EFFECT FOR THE TRIANGLE AND
TRIAD.
SIMILAR TO YESTERDAY, A HOT AND STAGNANT AIR MASS WILL REMAIN OVER
THE AREA AND RESULT IN ADDITIONAL CODE ORANGE AIR QUALITY ALERTS. IT
IS POSSIBLE THAT FINE PARTICULATES FROM SMOKE CURRENTLY STREAMING
ACROSS NY/PA MAY WORK DOWN INTO VA AND POTENTIALLY INTO THE PIEDMONT
OF NC LATER THIS MORNING. AVAILABLE GUIDANCE IN THE RRFS AND HRRR
SUGGEST THE HIGHEST CONCENTRATIONS WILL BE ACROSS NORTHERN NC,
PERHAPS INTO THE TRIAD, SO UPDATES TO THE CURRENT AIR QUALITY
ALERTS MAY BE NEEDED LATER TODAY.
KEY MESSAGE 2... HOT TEMPERATURES AND POTENTIALLY DANGEROUS HEAT
EXPECTED INTO SATURDAY.
AN ELONGATED MID-LVL RIDGE AXIS STRETCHING FROM THE LOWER OHIO
VALLEY, ACROSS THE CAROLINAS, AND INTO THE WESTERN ATLANTIC WILL
CONTINUE TO PROVIDE BACKGROUND SUBSIDENCE OVER THE REGION
BEFORE BREAKING DOWN ON SAT. H850 TEMPERATURES OF 19-22C
OBSERVED IN THE 12Z RAOBS OVER VA AND INTO NC WILL CONTINUE TO
SUPPORT HOT TEMPERATURES OVER THE REGION WITH MINIMAL
THERMAL/MOISTURE ADVECTION INTO SAT. OVERWHELMING MODEL SUPPORT
VIA LOW-LVL THICKNESS AND DRY-ADIABATIC TECHNIQUE SUPPORT
STATISTICAL GUIDANCE AS WELL AS THE NATIONAL BLEND TO RESULT IN
HIGH CONFIDENCE IN 2M TEMPERATURES REACHING THE UPPER 90S TO
AROUND 100 THIS AFTERNOON AND ONCE AGAIN ON FRI. HOWEVER,
CONFIDENCE IS LOWER WITH RESPECT TO DEW POINTS DURING PEAK
HEATING AND WHETHER THEY WILL SUPPORT MULTIPLE HOURS OF HEAT
INDICES IN THE MID/UPPER 100S, ESPECIALLY WEST OF THE US-1
CORRIDOR.
FORECAST CHALLENGES: MODEL GUIDANCE REMAINS CONSISTENT WITH
NORTHERLY WINDS PERSISTING OVER THE PIEDMONT INTO PEAK HEATING
WHERE CONTINUED DRY AIR ALOFT AND SOME LIGHT DOWNSLOPING
COMPONENT WEST OF A WEAK PRESSURE TROUGH MAY HELP MIX DEW POINTS
INTO THE LOW/MID 60S ON FRI. ADDITIONALLY WITHIN THOSE
NORTHWESTERLY WINDS, HAZE/SMOKE FROM CANADIAN WILDFIRES MAY BE
DEPOSITED INTO OUR AREA, WHICH MAY FURTHER THE TEMPERATURE
FORECAST. FINALLY, HI-RES GUIDANCE IS BEGINNING TO DEVELOP
ISOLATED TO EVEN LOCALLY SCATTERED SHOWERS/STORMS FRI AFTERNOON
WITH COOL OUTFLOW POTENTIALLY LIMITING THE WINDOW TO REACH HEAT
INDICES AROUND 105. REGARDLESS ON WHETHER HEAT INDICES OF 105
ARE MET, LIGHT TO NEARLY STAGNANT SURFACE WINDS, ABUNDANT
SUNSHINE AND HOT TEMPERATURES WILL STILL PROVIDE A FAVORABLE AIR
MASS FOR HEAT RELATED ILLNESSES TO OCCUR AMONG ANY INDIVIDUAL
WHO DOES NOT HAVE ACCESS TO ADEQUATE HYDRATION OR COOLING.
KEY MESSAGE 3... BECOMING UNSETTLED THIS WEEKEND INTO EARLY NEXT
WEEK WITH INCREASED PRECIP CHANCES.
A RATHER STOUT SHORTWAVE FOR LATE JULY WILL CROSS THE GREAT LAKES
THIS WEEKEND AND CARVE OUT A TROUGH TO REPLACE THIS WEEK’S RIDGE
OVER THE OH VALLEY AND SOUTHERN MID ATLANTIC. MODEST HEIGHT FALLS
ASSOCIATED WITH THE TROUGH WILL OVERSPREAD WHAT SHOULD BE A MODERATE
UNSTABLE AIRMASS AND SUPPORT AN INCREASE IN STORMS LATER SATURDAY
AND MORE SO ON SUNDAY, WITH ADDITIONAL FOCUS FROM A CONVECTIVELY
MODIFIED FRONTAL ZONE THAT IS FORECAST TO SLIP INTO THE AREA AHEAD
OF THE MAIN SYNOPTIC FRONT. DETAILS MAY DEPEND ON WHERE THE
BOUNDARY ENDS UP, BUT SPC HAS ADDED A SLIGHT RISK FOR NORTHERN NC ON
SATURDAY AND ALL OF CENTRAL NC ON SUNDAY.
MEANWHILE, NHC WILL BE WATCHING AN UPPER TROUGH THAT IS MIGRATING
FROM THE CARIBBEAN TO THE NORTHEAST GULF AND WHETHER OR NOT A
SURFACE WAVE WILL DEVELOP, POTENTIALLY HELPING TO DIRECT TROPICAL
MOISTURE NORTH ALONG THE NC COAST TO SUPPORT ADDITIONAL UNSETTLED
WEATHER INTO MONDAY. AND THEN FINALLY A STRONGER COLD FRONT IS
FORECAST TO SWING THROUGH THE REGION MIDWEEK, WHICH MAY BRING
ANOTHER ROUND OF SHOWERS AND STORMS.
OVERALL EASTERN NC IS FAVORED FOR MULTIPLE ROUNDS OF SHOWERS AND
STORMS, RESULTING IN AS MUCH AS 1-3 INCHES OF RAIN IN THE COASTAL
PLAIN BY THE MIDDLE OF NEXT WEEK.
AVIATION /00Z FRIDAY THROUGH TUESDAY/
AS OF 750 PM THURSDAY...
PREVAILING VFR CONDITIONS ARE EXPECTED. ALTHOUGH SUB-VFR VSBY CAN'T
BE COMPLETELY RULED OUT DUE TO HAZE/SMOKE AT THE NORTHERN TERMINALS
FRI MORNING, MODEL GUIDANCE IS TRENDING FARTHER NORTH WITH THE
SOUTHERN EXTENT OF THE HIGHER CONCENTRATIONS OF FINE PARTICULATES
FROM SMOKE. ISOLATED SHOWER OR BRIEF STORM WILL BE POSSIBLE ANYWHERE
WITHIN CENTRAL NC FRI AFTERNOON/EVENING.
OUTLOOK: INCREASING CHANCES FOR DIURNALLY DRIVEN SHOWERS/STORMS
EACH AFTERNOON HEADING INTO THE WEEKEND. A WAVY FRONTAL ZONE
WAFFLING OVER THE REGION THIS WEEKEND INTO EARLY NEXT WEEK MAY
RESULT IN A MORE ACTIVE WEATHER PATTERN TO SUPPORT SUB-VFR
CONDITIONS FROM STRATUS/MIST OVERNIGHT AND SCATTERED TO LOCALLY
NUMEROUS SHOWERS/STORMS IN THE AFT/EVE.
CLIMATE
RECORD TEMPERATURES WITHIN 3F OF FORECAST ONES...
RECORD HIGHS:
JULY 17: KRDU: 100/1887 KFAY: 102/1932
JULY 18: KGSO: 97/1986
RECORD HIGH MINS:
JULY 17: KGSO: 75/2025 KFAY: 77/2019
JULY 18: KGSO: 76/1986 KFAY: 77/2025
JULY 19: KGSO: 75/2016 KFAY: 77/2023
RAH WATCHES/WARNINGS/ADVISORIES
AIR QUALITY ALERT FROM 10 AM TO 8 PM EDT FOR NCZ008-021>023-025-038-
039-041.
DISCUSSION...BLS
AVIATION...AS/MWS
CLIMATE...
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