220
FXUS62 KRAH 080813
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
413 AM EDT SUN JUN 8 2025
SYNOPSIS
A SERIES OF MID AND UPPER-LEVEL DISTURBANCES WILL OVERSPREAD AND
INTERACT WITH A FRONTAL ZONE THAT WILL SETTLE INTO AND STALL OVER NC
THROUGH EARLY TO MID WEEK.
NEAR TERM /TODAY AND TONIGHT/
AS OF 300 AM SUNDAY...
* ISOLATED TO SCATTERED STRONG TO SEVERE STORMS ARE POSSIBLE THIS
AFTERNOON AND EVENING
ISOLATED TO WIDELY SCATTERED SHOWERS WILL CONTINUE TO DEVELOP AND
TRACK NORTHEAST AHEAD OF A WELL-DEFINED MCV, WHICH IS EXPECTED TO
EXIT THE AREA BETWEEN 09-12Z.
A LOW-AMPLITUDE SHORTWAVE TROUGH WILL PROGRESS EASTWARD FROM THE MID
MS VALLEY THIS MORNING, CROSSING THE TN VALLEY TODAY, AND REACHING
THE CAROLINAS DURING THE EVENING AND EARLY OVERNIGHT HOURS. AHEAD OF
THIS FEATURE, ONGOING CONVECTION OVER THE MID SOUTH WILL SEND
ANOTHER CLUSTER OF MCVS INTO THE SE US BETWEEN 12 TO 18Z. WHILE THE
BULK OF THIS ACTIVITY IS EXPECTED TO REMAIN SOUTH OF THE AREA, A
WEAKER, GLANCING INFLUENCE MAY STILL BRING SUFFICIENT LIFT TO
SUPPORT ISOLATED TO SCATTERED CONVECTION. ESPECIALLY ACROSS SOUTHERN
OR SOUTHEASTERN PORTIONS OF THE FORECAST AREA BETWEEN 14 TO 21Z.
THE ARRIVAL OF THE AFOREMENTIONED SHORTWAVE TROUGH WILL LIKELY BRING
ADDITIONAL ISOLATED TO SCATTERED SHOWERS AND STORMS AREA-WIDE
BETWEEN 21 TO 06Z.
TODAY'S ENVIRONMENTAL IS SIMILAR TO YESTERDAY, WITH STRONG SFC
HEATING YIELDING AFTERNOON HIGHS IN THE MID/UPPER 80S NORTH TO
LOWER/MID 90S SOUTH, AND DEWPOINTS IN THE UPPER 60S TO LOWER 70S,
SUPPORTING MODERATE TO STRONG DESTABILIZATION. SHEAR OF 25-35 KTS
WILL BE SUPPORTIVE OF MULTI-CELLULAR CONVECTION. DAMAGING WIND GUSTS
REMAIN THE PRIMARY THREAT, WITH HAIL AS A SECONDARY, ISOLATED
CONCERN.
CONVECTIVE RAIN CHANCES WILL DIMINISH AS THE SHORTWAVE TROUGH EXITS
THE REGION TONIGHT, WITH DRY CONDITIONS EXPECTED AFTER 06Z.
WARM AND MUGGY CONDITIONS WILL PERSIST OVERNIGHT, WITH LOWS RANGING
FROM MID 60S TO LOWER 70S.
SHORT TERM /MONDAY AND MONDAY NIGHT/
AS OF 400 AM SUNDAY...
AN OCCLUDED CYCLONE WILL SLOWLY DRIFT NNE FROM THE UPPER GREAT LAKES
INTO SOUTHERN ONTARIO ON MONDAY AND MONDAY NIGHT, DRAGGING A COLD
FRONT TO ITS SOUTH THAT REACHES THE APPALACHIANS BY TUESDAY MORNING.
MEANWHILE A SEPARATE WEAKER COLD FRONT LOOKS TO STALL OUT OVER
CENTRAL NC ON MONDAY. BUT WITH MID-LEVEL HEIGHT RISES FROM SHORTWAVE
RIDGING PLUS WEAK BACKGROUND WIND FIELDS, MUCH OF THE DAY THROUGH AT
LEAST MID AFTERNOON COULD BE DRY. THIS IS BACKED UP BY THE 00Z CAMS
(INCLUDING THE HRRR AND NAM NEST), WHICH DON'T DEPICT ANY CONVECTION
DEVELOPING OR MOVING INTO CENTRAL NC UNTIL AFTER 21Z AT THE
EARLIEST. THE DECREASE IN CLOUDS/PRECIPITATION COMPARED TO SUNDAY
MAY HELP TEMPERATURES GET A BIT WARMER, BUT OVERALL STILL EXPECTING
HIGHS MOSTLY UPPER-80S TO LOWER-90S, WITH HEAT INDICES IN THE LOWER-
TO-MID-90S ACROSS THE SOUTH AND EAST.
HOWEVER, AN MCS IS EXPECTED TO REINTENSIFY AND TRACK ENE FROM
MS/AL/GA ON MONDAY MORNING AND AFTERNOON, WITH THE ASSOCIATED MCV
AND SHORTWAVE TROUGH THEN TRACKING NE ACROSS CENTRAL NC IN THE
EVENING AS THE SHORTWAVE RIDGING EXITS. THIS DISTURBANCE AND
RESULTANT OUTFLOW IS LIKELY TO RESULT IN AN INCREASE IN SHOWERS AND
STORMS BY LATE AFTERNOON OR EARLY EVENING, FIRST ACROSS SOUTHERN
PORTIONS OF CENTRAL NC BEFORE SPREADING NORTH FROM LATE EVENING INTO
THE OVERNIGHT HOURS. THE SEA BREEZE MAY PROVIDE AN ADDITIONAL FOCUS
FOR CONVECTIVE DEVELOPMENT IN THE SE. WHILE INSTABILITY DOESN'T LOOK
AS STRONG AS PREVIOUS DAYS, 500-1500 J/KG OF MLCAPE WILL STILL BE
POSSIBLE, GREATEST AHEAD OF THE STALLED BOUNDARY. SO INCREASE POPS
TO CHANCE MONDAY LATE AFTERNOON INTO MONDAY NIGHT, HIGHEST SOUTH AND
EAST. MID-LEVEL FLOW WILL ALSO STRENGTHEN DURING THE EVENING AS THE
MCV/SHORTWAVE MOVES ACROSS, WITH GUIDANCE DEPICTING AS MUCH AS 30-40
KTS OF DEEP LAYER SHEAR. THUS THE SPC HAS AT LEAST A MARGINAL (LEVEL
1 OF 5) RISK OF SEVERE STORMS ACROSS CENTRAL NC FOR MONDAY AND
MONDAY NIGHT, WITH A SLIGHT (LEVEL 2 OF 5) ACROSS THE SOUTH WHICH
HAS THE BEST CHANCE OF EXPERIENCING THE EFFECTS OF THE MCV BEFORE
CIN AND LOSS OF DAYTIME HEATING TAKE OVER. WHILE DAMAGING WINDS ARE
THE MAIN THREAT, ISOLATED LARGE HAIL AND PERHAPS A TORNADO WILL BE
POSSIBLE AS THE MESOLOW ASSOCIATED WITH THE MCV MOVES ACROSS. IT
SHOULD ALSO BE NOTED THAT MODELS OFTEN STRUGGLE WITH PREDICTING THE
TIMING AND INTENSITY OF THESE SMALL UPPER DISTURBANCES, AND RECENT
DAYS HAVE BEEN NO EXCEPTION. SO THIS MAY BE MORE OF A NOWCASTING
SITUATION.
HIGH-RES GUIDANCE DEPICTS YET ANOTHER MCV MOVING FROM SC INTO
EASTERN NC ON MONDAY NIGHT, WITH ANOTHER ROUND OF CONVECTION
POSSIBLE, PARTICULARLY IN SOUTHERN AND EASTERN PARTS OF OUR REGION.
HOWEVER, UNFAVORABLE DIURNAL TIMING LOWERS CONFIDENCE IN SEVERE
POTENTIAL. INCREASING CLOUD COVER WILL RESULT IN A MILD NIGHT, WITH
LOWS IN THE UPPER-60S TO LOWER-70S.
LONG TERM /MONDAY THROUGH SATURDAY/
AS OF 400 AM SUNDAY...
THE CLOSED MID/UPPER LOW WILL OPEN UP INTO A WAVE AND MOVE NE ACROSS
SOUTHERN ONTARIO AND QUEBEC ON TUESDAY AND TUESDAY NIGHT, AS THE
BROAD TROUGH OVER THE EASTERN US PUSHES FARTHER EAST. AT THE
SURFACE, A WEAKENING COLD FRONT WILL MOVE THROUGH CENTRAL NC ON
TUESDAY EVENING/NIGHT, WITH A LEE TROUGH SETTING UP OUT AHEAD OF IT.
A SEPARATE STALLED BOUNDARY WILL ALSO LINGER ACROSS CENTRAL NC
DURING THE DAY BEFORE GETTING OVERTAKEN BY THE STRONGER FRONT. MORE
SHOWERS AND STORMS ARE POSSIBLE TUESDAY AFTERNOON/EVENING GIVEN 500-
1500 J/KG OF MLCAPE SOUTH AND EAST OF THE STALLED BOUNDARY. BULK
SHEAR WILL BE LIMITED TO 25-35 KTS AT MOST, WITH THE STRONGER MID-
LEVEL FLOW TO OUR NORTH. ALSO, BROAD-SCALE FORCING APPEARS MODEST AS
WE WILL ACTUALLY BE EXPERIENCING MID-LEVEL HEIGHT RISES BY THIS
POINT WITH DAMPENING OF THE BROAD EASTERN US TROUGH. SO SHOWER/STORM
COVERAGE MAY BE MORE SCATTERED IN NATURE, AND CUT DOWN POPS A BIT
FROM NBM, RANGING FROM LOW-END CHANCE IN THE FAR NW TO LOW-END
LIKELY IN THE FAR SE. GIVEN ALL THIS, THE SEVERE THREAT LOOKS MORE
ISOLATED, AND SPC HAS INTRODUCED A DAY 3 MARGINAL (LEVEL 1 OF 5)
RISK FOR MUCH OF CENTRAL NC OUTSIDE OF THE NW PIEDMONT, WITH THE
MAIN THREAT BEING DAMAGING WINDS. TUESDAY'S FORECAST HIGHS GO BACK
DOWN SLIGHTLY TO MID-TO-UPPER-80S WITH THE INCREASED CLOUDS AND
PRECIPITATION CHANCES. DRIER N/NW FLOW BEHIND THE COLD FRONT WILL
END PRECIPITATION CHANCES TUESDAY EVENING/NIGHT FROM NW TO SE. LOWS
WILL RANGE FROM LOWER-60S NW TO UPPER-60S SE.
THE COLD FRONT WILL STALL OVER THE EASTERN CAROLINAS ON WEDNESDAY
AND THURSDAY, AS SURFACE HIGH PRESSURE BUILDS INTO THE MID-ATLANTIC.
LOOKING ALOFT, MID/UPPER TROUGHING OVER THE NORTHEAST US ON
WEDNESDAY WILL LIFT FARTHER NE INTO EASTERN CANADA, GETTING REPLACED
BY RIDGING THAT BUILDS INTO THE SOUTHEAST US. DETERMINISTIC AND
ENSEMBLE GUIDANCE HAVE BEEN TRENDING FARTHER SOUTH WITH THE STALLED
FRONT AND THUS DRIER ON WEDNESDAY AND THURSDAY, SO ONLY HAVE SLIGHT
TO LOW CHANCE POPS IN THE S/SE IN CLOSEST PROXIMITY TO THE BOUNDARY.
THE RIDGING WILL THEN BEGIN TO FLATTEN AND SUPPRESS TO OUR SOUTH ON
FRIDAY AND SATURDAY, IN RESPONSE TO THE NEXT TROUGH MOVING ACROSS
THE CENTRAL US, AND AS A LEE SURFACE TROUGH SETS UP OVER THE
SOUTHERN MID-ATLANTIC. MEANWHILE THE STALLED FRONT MAY START TO LIFT
BACK NORTH AS A WARM FRONT WITH INCREASED S/SW FLOW AROUND A BERMUDA
HIGH, BRINGING MORE MOIST AND UNSTABLE AIR BACK TO OUR REGION. SO
SHOWER AND STORM CHANCES INCREASE AGAIN ON FRIDAY AND SATURDAY, BUT
CAPPED POPS AT CHANCE FOR NOW. WEDNESDAY'S FORECAST TEMPERATURES
(HIGHS IN THE MID-80S TO 90, LOWS IN THE 60S) ALSO INCREASE FROM
THURSDAY THROUGH SATURDAY (HIGHS UPPER-80S TO LOWER-90S, LOWS UPPER-
60S TO LOWER-70S).
AVIATION /060Z SUNDAY THROUGH THURSDAY/
AS OF 145 AM SUNDAY...
ISOLATED TO WIDELY SCATTERED SCATTERED SHOWERS AND STORMS WILL
CONTINUE TO MOVE EAST AHEAD OF UPPER LEVEL DISTURBANCE EXPECTED TO
SHIFT EAST OF THE AREA BETWEEN 09 TO 12Z. LATEST FORECAST GUIDANCE
SHOWS A LOWER LIKELIHOOD OF SUB-VFR RESTRICTIONS DEVELOPING ACROSS
THE NORTHERN TERMINALS THROUGH DAYBREAK.
ADDITIONAL UPPER DISTURBANCES WILL TRACK THROUGH THE REGION
THROUGHOUT THE DAY AND INTO THE EVENING, SUPPORTING SCATTERED
SHOWERS AND STORMS.
SWLY WINDS WILL INCREASE BY EARLY AFTERNOON, GUSTING TO 20 TO 25 KTS
BEFORE DIMINISHING IN THE EVENING.
OUTLOOK: THE DAILY PATTERN OF SCATTERED SHOWERS AND STORMS WILL
PERSIST INTO TUESDAY, AHEAD OF AN APPROACHING COLD FRONT. DRIER
CONDITIONS ARE EXPECTED WEDNESDAY AND THURSDAY FOLLOWING THE FRONTAL
PASSAGE. PERIODS OF MORNING STRATUS AND/OR FOG MAY BE POSSIBLE
DURING THIS STRETCH.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...CBL
SHORT TERM...DANCO
LONG TERM...DANCO
AVIATION...CBL
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