309
FXUS62 KRAH 270705
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
305 AM EDT SAT JUN 27 2026
WHAT HAS CHANGED
* THERE IS A MARGINAL/SLIGHT RISK OF SEVERE STORMS TODAY AND
SUNDAY.
* A HEAT WAVE CONTINUES TO BE EXPECTED WEDNESDAY THROUGH THE JULY
4TH WEEKEND.
KEY MESSAGES
AS OF 305 AM SATURDAY...
1) SEVERE THUNDERSTORM RISK BOTH TODAY AND SUNDAY.
2) A DANGEROUS HEAT WAVE IS EXPECTED WEDNESDAY THROUGH THE JULY 4TH
WEEKEND.
DISCUSSION
AS OF 305 AM SATURDAY...
KEY MESSAGE 1: SEVERE THUNDERSTORM RISK BOTH TODAY AND SUNDAY.
THE PRIMARY WEATHER CONCERN THIS WEEKEND IS THE RISK OF AFTERNOON
AND EVENING SEVERE THUNDERSTORM ACTIVITY. THE SETUP FOR THIS RISK
TODAY INCLUDES AFTERNOON TEMPS RISING INTO THE LOWER 90S, DWPTS IN
THE LOWER TO MID 70S, MLCAPE GENERALLY 2000+ J/KG, WEAK BUT ADEQUATE
20-30 KT DEEP-LAYER SHEAR, AND FORECAST DCAPE AOA 1000 J/KG. THE
TIMING OF TODAY'S STORMS DEPENDS LARGELY ON ONGOING UPSTREAM STORM
ACTIVITY ACROSS THE OHIO VALLEY. AS THOSE STORMS MOVE EAST, LOOK
FOR NEW CONVECTION TO DEVELOP EASTWARD ALONG OUTFLOW BOUNDARIES.
STORMS WILL ARRIVE OR DEVELOP BY MID-AFTERNOON OVER THE WESTERN
PIEDMONT BEFORE EXPANDING EASTWARD AND MOVING THROUGH THE TRIANGLE
AND COASTAL PLAIN REGIONS DURING THE LATE AFTERNOON AND EVENING.
GIVEN THE AFOREMENTIONED SETUP, THE PRIMARY SEVERE THREAT REMAINS
DAMAGING STRAIGHT-LINE WINDS (50-70 MPH), LOCALIZED WET MICROBURSTS,
AND MARGINALLY SEVERE HAIL WITH THE STRONGEST CORES. STORMS WILL
MOVE EAST OF CENTRAL NC DURING THE LATER EVENING HOURS AND SHOULD BE
FOLLOWED BY A MAINLY DRY OVERNIGHT PERIOD GIVEN A POST-STORM STABLE
LOW LEVEL AIRMASS THAT WILL BE PLACE. ALL OF CENTRAL NC IS IN A
SLIGHT (LEVEL 2 OF 5) RISK FOR SEVERE STORMS TODAY PER THE LATEST
SWODY1.
SUNDAY APPEARS TO PRESENT A SOMEWHAT DIFFERENT CONVECTIVE EVOLUTION,
YET STILL HAVING A POSSIBLE SEVERE RISK. WHILE MID-LEVEL HEIGHTS
BEGIN RISING AS THE LOWER MISS RIDGE EXPANDS, BOTH THE GFS AND ECMWF
CONTINUE TO INDICATE THAT A WEAK SHORTWAVE RIDING AROUND THE
NORTHERN EDGE OF THE RIDGE WILL ACCOMPANY A DECAYING MCS MOVING
SOUTHEAST FROM THE OHIO VALLEY INTO VIRGINIA DURING THE MORNING. THE
MAIN QUESTION IS TO WHAT EXTENT THIS CONVECTION SURVIVES INTO OUR
AREA. IF MORNING CONVECTION WEAKENS SUBSTANTIALLY, CLOUD COVER
SHOULD ERODE SUFFICIENTLY TO ALLOW ANOTHER STRONGLY UNSTABLE
AFTERNOON WITH MLCAPE EXCEEDING 2500 J/KG. IF SUFFICIENT RECOVERY
OCCURS, ORGANIZED MULTICELLS COULD DEVELOP DURING THE AFTERNOON,
PARTICULARLY ACROSS NORTHERN AND EASTERN PORTIONS OF CENTRAL NORTH
CAROLINA. DAMAGING WINDS AGAIN APPEAR TO BE THE MAIN CONCERN DUE
TO LARGE SUB-CLOUD LAPSE RATES AND HIGH DCAPE. HEAVY RAINFALL IS
ALSO POSSIBLE GIVEN PRECIPITABLE WATER VALUES APPROACHING 2 INCHES.
NEARLY ALL OF CENTRAL NC (WITH THE EXCEPTION OF OUR FAR WESTERN
ZONES) IS IN A MARGINAL (LEVEL 1 OF 5) RISK FOR SEVERE STORMS ON
SUNDAY PER LATEST SWODY2.
KEY MESSAGE 2... A DANGEROUS HEAT WAVE IS EXPECTED WEDNESDAY THROUGH
THE JULY 4TH WEEKEND.
MODELS CONTINUE TO FORECAST AN ANOMALOUS MID/UPPER RIDGE OVER THE
OHIO/TENNESSEE VALLEY/CENTRAL APPALACHIANS BEGINNING MID NEXT WEAK,
THEN PEAKING ON POSSIBLY THE JULY 4TH WEEKEND. THIS IS HISTORICALLY
A FAVORED LOCATION OF THE MID/UPPER RIDGE POSITION THAT HAVE BROUGHT
PAST HEAT WAVES TO OUR REGION.
THE COMBINATION OF STRONG SUBSIDENCE, LACK OF CLOUDS, DRY GROUND,
AND A DOWNSLOPE LOW AND MID LEVEL FLOW - COULD POTENTIALLY YIELD A
NEAR HISTORICAL HEAT EVENT BRINGING VERY DANGEROUS CONDITIONS. SOME
GUIDANCE IS NOW FORECASTING A FEW DISTURBANCES IN THE NW-N FLOW
ALOFT RIDING INTO THE REGION BY FRIDAY AND SATURDAY THE 4TH. THIS
MAY BE ENOUGH TO TRIGGER EITHER WIDELY SCATTERED OR SCATTERED (20-30
PERCENT CHANCE) OF AFTERNOON OR EARLY NIGHTTIME THUNDERSTORMS
PERHAPS BRINGING SOME TEMPORARY COOLING. MODELS ARE ALSO HINTING AT
THE RIDGE BREAKING DOWN AND SHIFTING WEST BEGINNING THE 4TH OR 5TH.
WE TYPICALLY END HEAT WAVES WITH SOME STRONG THUNDERSTORMS BEFORE
THE COOLING.
BOTTOM LINE... BEGIN PREPARATIONS NOW FOR THE POTENTIAL FOR HIGHS
POSSIBLY 100+ FOR 3-4 CONSECUTIVE DAYS, DAYTIME APPARENT
TEMPERATURES POSSIBLY PEAKING AT 105+ IN THE TRIAD, AND 105-112
ELSEWHERE WED-SAT. TO MAKE MATTERS WORSE, OVERNIGHT LOWS MAY HAVE A
HARD TIME DROPPING BELOW 80, ESPECIALLY IN URBAN AREAS.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
AS OF 305 AM SATURDAY...
THROUGH 06Z SUNDAY: CURRENTLY SEEING LOCALIZED MVFR AND IFR STRATUS
AND FOG, ESP OVER THE COASTAL PLAIN OF NC. WE EXPECT THE IFR AND
PERHAPS SOME LIFR FOG AND STRATUS TO EXPAND ACROSS CENTRAL NC OVER
THE NEXT SEVERAL HOURS AND PRIOR TO SUNRISE GIVEN THE ABUNDANCE OF
LLVL MOISTURE CURRENTLY IN PLACE. AFTER SUNRISE AND WITH DAYTIME
HEATING, THE STRATUS WILL LIFT WITH VFR CONDITIONS RETURNING ACROSS
ALL OF CENTRAL NC BY 15Z. THEN THE NEXT AVIATION CONCERN WILL BE
AFTERNOON AND EVENING CONVECTION. CURRENT CAM GUIDANCE GENERALLY
FAVORS CONVECTIVE INITIATION BETWEEN 17-20Z OVER THE WESTERN
PIEDMONT (KINT/KGSO) BEFORE STORMS EXPAND EASTWARD THROUGH THE
TRIANGLE AND COASTAL PLAIN DURING THE LATE AFTERNOON AND EARLY
EVENING (KRDU, KFAY, AND KRWI). COVERAGE IS EXPECTED TO REMAIN
SCATTERED RATHER THAN WIDESPREAD, BUT ANY TERMINAL DIRECTLY IMPACTED
COULD EXPERIENCE BRIEF IFR CONDITIONS IN HEAVY RAINFALL, VISIBILITY
BELOW 1 SM, CEILINGS BELOW 1 KFT, AND ERRATIC WIND GUSTS OF 35-50
KT. AFTER 02-04Z, CONVECTION SHOULD GRADUALLY DIMINISH WITH LOSS OF
DAYTIME HEATING AND AS THE STORMS EXIT TO OUR EAST. LIGHT SOUTHERLY
WINDS AND ABUNDANT LLVL MOISTURE MAY SUPPORT REDEVELOPMENT OF PATCHY
IFR STRATUS, ESPECIALLY EAST OF US-1 TOWARD KRWI AND KFAY LATE
TONIGHT, ALTHOUGH CONFIDENCE IN WIDESPREAD RESTRICTIONS REMAINS ONLY
MODERATE.
OUTLOOK
GENERALLY VFR CONDITIONS ARE EXPECTED INTO MONDAY AND
TUESDAY.
CLIMATE
RECORD HIGH TEMPERATURES:
JULY 1: KGSO: 99/2012 KRDU: 103/2012 KFAY: 104/1959
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...NP/BADGETT
AVIATION...NP
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