533
FXUS62 KRAH 200636
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
236 AM EDT MON JUL 20 2026
WHAT HAS CHANGED
* IN AN ACTIVE PATTERN WITH DAILY THREATS OF SEVERE WIND AND
FLOODING FOR THE NEXT FEW DAYS, THERE IS NOW A SLIGHT RISK (LEVEL
2 OF 5) OF SEVERE THUNDERSTORMS WITH DAMAGING DOWNBURSTS ACROSS
CNTL NC TODAY.
KEY MESSAGES
AS OF 116 PM SUNDAY...
1) A HEAT ADVISORY MAY BE NEEDED FOR THE SANDHILLS AND SOUTHERN
COASTAL PLAIN MONDAY.
2) A MARGINAL TO SLIGHT RISK OF SEVERE STORMS REMAINS FOR MONDAY,
ALONG WITH A HEAVY RAINFALL THREAT.
3) CONTINUED PERIODS OF UNSETTLED WEATHER THIS WEEK AS A
STALLED FRONT LINGERS ACROSS NC.
DISCUSSION
AS OF 116 PM SUNDAY...
KEY MESSAGE 1... A HEAT ADVISORY MAY BE NEEDED FOR THE SANDHILLS AND
SOUTHERN COASTAL PLAIN MONDAY.
A HEAT ADVISORY MAY BE NEEDED MONDAY, BUT FOR A SMALLER AREA OF THE
EASTERN SANDHILLS INTO THE SOUTHERN COASTAL PLAIN. AS DEWPOINTS
REMAIN HIGH IN THE MID 70S AND TEMPERATURES WARM INTO THE LOW 90S,
HEAT INDICES WILL CERTAINLY GET CLOSE TO ADVISORY CRITERIA.
KEY MESSAGE 2... A MARGINAL TO SLIGHT RISK OF SEVERE STORMS
REMAINS FOR TODAY AND MONDAY, ALONG WITH A HEAVY RAINFALL THREAT.
A SLIGHT RISK OF SEVERE STORMS REMAINS IN PLACE THROUGH TONIGHT FOR
ALL OF CENTRAL NC AND A MARGINAL RISK OF STORMS IS IN PLACE
MONDAY.
AS FOR STORM COVERAGE, IT APPEARS ISOLATED TO SCATTERED ACTIVITY
THIS AFTERNOON AND EARLY EVENING COULD BECOME WIDESPREAD OVER
PORTIONS OF THE REGION LATE TONIGHT AND OVERNIGHT. A SURFACE
BOUNDARY IS EVIDENT ON SATELLITE AND SURFACE OBS ALONG THE
NORTHERN PIEDMONT, BETWEEN THE TRIAD AND NORTH OF RDU. AT THE
SAME TIME, A COLD FRONT ACROSS THE LOWER OH VALLEY AND VA WILL
GRADUALLY APPROACH FROM THE NORTH. STORMS HAVE ALREADY FORMED
ALONG THE SURFACE BOUNDARY, IN A REGION OF A CAPE GRADIENT AND
MAY ADDITIONALLY TRACK SOUTH OF THE FRONT IN VA. A HEAVY
RAINFALL THREAT WILL EXIST THIS AFTERNOON BUT ESPECIALLY
TONIGHT. AS THE FRONT APPROACHES LATER TONIGHT AND EARLY
MONDAY, THERE REMAINS A THREAT OF HEAVY RAINFALL AS THE LOW TO
MID- LAYER FLOW IS NEARLY PARALLEL TO THE BOUNDARY TO SUPPORT
TRAINING STORMS. THE HREF/REFS DIFFER ON THIS POTENTIAL, WITH
THE HREF SHOWING MORE OF A SIGNAL FROM RALEIGH EAST AND SOUTH
INTO THE COASTAL PLAIN. THE 12Z HREF/HRRR APPEAR TO BE COMING IN
LINE WITH THIS SCENARIO AS WELL, GIVEN WEAK UPWIND PROPAGATION
VECTORS. A SWATH OF 2-4 INCHES IS POSSIBLE IN THESE AREAS,
THOUGH CONFIDENCE ON EXACT LOCATION IS NOT GREAT.
THE FRONT AND/OR REMNANT OUTFLOWS WILL STALL ALONG OR NEAR THE US-64
CORRIDOR ON MONDAY. ADDITIONALLY, IT APPEARS THE SEA-BREEZE MAY BE
AN ADDITIONAL FOCUS FOR STORMS MONDAY AFTERNOON AND EVENING,
SUGGESTED BY A FEW HREF MEMBERS. MOISTURE VALUES REMAIN HIGH, WITH
AGAIN THE LOW TO MID-LAYER FLOW PARALLEL OR SLIGHTLY SOUTHWEST OF
THE BOUNDARY, FAVORING AGAIN TRAINING STORMS FOR HEAVY RAINFALL.
BOTH THE HREF/REFS SHOW THIS HEAVY RAINFALL SIGNAL MONDAY ALONG THE
US-64 CORRIDOR, BUT THE THREAT COULD BE ANYWHERE STORMS TRAIN AND
MOVE SLOWLY.
KEY MESSAGE 3... CONTINUED PERIODS OF UNSETTLED WEATHER THIS WEEK AS
A STALLED FRONT LINGERS ACROSS NC.
BROAD AND WEAK TROUGHING OVER THE EASTERN CONUS ON MON WILL BECOME
REINFORCED BY A MORE VIGOROUS SHORTWAVE TROUGH PIVOTING ACROSS THE
GREAT LAKES AND SOUTHERN QUEBEC ON TUES. A LOW-AMPLITUDE LIKELY
CONVECTIVELY ALTERED PERTURBATION RIPPLING THROUGH THE BASAL
PORTION OF THE TROUGH IS FORECAST TO SHIFT ACROSS THE OHIO VALLEY
TUES MORNING BEFORE POTENTIALLY SHIFTING ACROSS THE SOUTHERN MID-
ATLANTIC DURING PEAK HEATING. THERE ARE SOME NOTABLE TIMING
DIFFERENCES WITH THE LOW-PREDICITABILITY FEATURE, BUT NEVERTHELESS,
ENHANCED WESTERLY WINDS OF > 30 KTS ARE FORECAST TO SINK SOUTH AND
INTO NORTH CAROLINA AND OVERLAP A CONTINUED MOIST AND UNSTABLE
ENVIRONMENT. ALTHOUGH FLOW THROUGHOUT THE TROPOSPHERE IS NOT
PARTICULARLY STRONG, CONSISTENTLY VEERING WINDS WITH HEIGHT WILL
SUPPORT CURVED HODOGRAPHS CAPABLE OF PRODUCING TRANSIENT SUPERCELLS
AND BOWING SEGMENTS. ANY RIGHT-MOVING STORM WILL HAVE A STORM MOTION
OF SOUTHEAST AND INCREASE THE LIKELIHOOD THAT STORMS MAY DRIFT INTO
OUR REGION FROM VA. ALL HAZARDS WILL BE ON THE TABLE FOR TUESDAY,
ALTHOUGH DAMAGING STRAIGHT-LINE WINDS WILL BE THE MOST LIKELY
PRIMARY AND MORE WIDESPREAD HAZARD.
AN UPSTREAM SHORTWAVE TROUGH IS FORECAST TO CROSS THE MOUNTAINS
WEDNESDAY WITH AN ATTENDANT SURFACE COLD FRONT IN TOW. WITH PW'S
STILL AT OR NEAR 2" AND NEARLY 2000 J/KG OF MLCAPE AVAILABLE, STRONG
TO SEVERE STORMS ARE MORE THAN PLAUSIBLE WITH THE FRONT.
SIGNIFICANTLY LOWER PW'S WILL FOLLOW THE FRONT WITH SUBSTANTIALLY
LOWER PRECIP CHANCES THURSDAY THROUGH SATURDAY, ALTHOUGH MODEL
INCONSISTENCIES REGARDING HOW FAR SOUTH THE FRONT AND DRIER AIR PUSH
SOUTH RESULTS IN AN LOWER FORECAST CONFIDENCE IN A DRY SPELL;
ESPECIALLY WITH SUCH A WEAK AND PROGRESSIVE SURFACE HIGH AND
CLIMATOLOGICALLY APPROACHING THE WINDOW WHEN IT IS DIFFICULT FOR
FRONTS TO PROGRESS ALL THE WAY THROUGH THE CAROLINAS.
AVIATION /06Z MONDAY THROUGH FRIDAY/
AS OF 225 AM MONDAY...
AREAS OF LIFR-MVFR STRATUS WILL LIKELY CONTINUE TO DEVELOP AND
EXPAND IN COVERAGE ACROSS SRN VA AND NRN NC THIS MORNING, ALONG AND
BEHIND AN OUTFLOW-REINFORCED SURFACE FRONT/PRESSURE TROUGH THAT WILL
SETTLE INTO N-CNTL NC THROUGH THE MORNING. ADDITIONALLY, STRATIFORM
RAIN RELATED TO A CONVECTIVELY-AMPLIFIED MID-LEVEL DISTURBANCE (MCV)
OVER THE SANDHILLS MAY CAUSE PATCHY IFR-MVFR CEILINGS TO DEVELOP
AROUND FAY. WHILE A FEW SHOWERS MAY LINGER OTHERWISE AND ELSEWHERE
THIS MORNING, HEAVIER SHOWERS AND STORMS ARE LIKELY TO DEVELOP WITH
DIURNAL HEATING OF AN UNSEASONABLY MOIST/HUMID AIRMASS FROM LATE
MORNING THROUGH THIS EVENING - FOCUSED ALONG THE AFOREMENTIONED
PRESSURE TROUGH/FRONT, OUTFLOW, AND DIFFERENTIAL HEATING AT THE
EDGES OF MID-LEVEL CLOUD DEBRIS FROM THE AFOREMENTIONED MCV.
OUTLOOK: AN UNSEASONABLY MOIST/HUMID AIRMASS, AND LIFT PERIPHERAL TO
THE MID-LATITUDE WESTERLIES THAT WILL DIP TO ATYPICALLY LOW
LATITUDES FOR THIS TIME OF YEAR WITHIN A TROUGH FROM THE GREAT LAKES
TO THE MIDDLE ATLANTIC, WILL FAVOR ABOVE AVERAGE CHANCES OF SHOWERS
AND STORMS AND ALSO OVERNIGHT STRATUS AND FOG - BOTH THROUGH WED.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...KREN/SWIGGETT
AVIATION...MWS
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