369
FXUS62 KRAH 271906
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
305 PM EDT MON APR 27 2026
WHAT HAS CHANGED
* NOTHING APPRECIABLE
KEY MESSAGES
AS OF 300 PM MONDAY...
1) DECAYING REMNANTS OF UPSTREAM CONVECTION MAY PRODUCE LIGHT
RAINFALL AMOUNTS OVER THE WRN NC PIEDMONT EARLY TUE.
2) MARGINAL RISK (LEVEL 1 OF 5) FOR ISOLATED SEVERE STORMS ON
WEDNESDAY.
3) STILL A CHANCE FOR MORE RAIN FROM FRIDAY TO SUNDAY.
DISCUSSION
AS OF 300 PM MONDAY...
KEY MESSAGE 1... DECAYING REMNANTS OF UPSTREAM CONVECTION MAY
PRODUCE LIGHT RAINFALL AMOUNTS OVER THE WRN NC PIEDMONT EARLY TUE.
THE REMAINS OF WHAT WILL LIKELY BE WIDESPREAD STRONG TO SEVERE
STORMS CENTERED OVER THE MID MS VALLEY THIS AFTERNOON-EVENING ARE
EXPECTED TO WEAKEN WITH TIME AND EWD EXTENT INTO AND ACROSS THE SRN
AND CNTL APPALACHIANS TUE MORNING, WHERE FOREGOING DEEP DRYNESS AND
STABILITY WILL EXIST FROM BOTH PRECEDING MID/UPR-LEVEL RIDGING AND
AN EML THAT HAS ADVECTED FROM THE CNTL ROCKIES TO THE SRN MIDDLE
ATLANTIC DURING THE PAST COUPLE OF DAYS. MOSTLY STRATIFORM RAIN, AND
MID-LEVEL CEILINGS CENTERED IN THE 7-12 THOUSAND FT LAYER, WILL
RESULT OVER THE WRN NC PIEDMONT. THE NAM AND ITS 3KM NEST ARE (HIGH)
OUTLIERS WITH RESPECT TO BOTH QPF AND MUCAPE OF UP TO A FEW HUNDRED
J/KG ROOTED ATYPICALLY HIGH AND AROUND 700 MB IN THEIR SIMULATIONS
AND ARE CONSIDERED UNLIKELY TO VERIFY. INSTEAD, RAINFALL AMOUNTS ARE
EXPECTED TO BE LESS AND MOSTLY BETWEEN A HUNDREDTH AND TENTH OF AN
INCH WHERE ANY REACHES THE GROUND OVER THE WRN PIEDMONT. IN FACT,
CONVECTION-ALLOWING (HREF) ENSEMBLE GUIDANCE INDICATES A 30-50%
PROBABILITY OF 0.01" OVER THE NW PIEDMONT, WITH A 10% PROBABILITY
OF GREATER THAN 0.10" OVER THE FAR NW FORSYTH CO. LREF PROBABILITIES
OF THOSE AMOUNTS ARE SLIGHTLY HIGHER: 10-75% OF 0.01" OVER THE WRN
HALF OF CNTL NC (ROUGHLY WEST OF US HWY 1) AND 10-30% OF 0.10" OVER
THE NW PIEDMONT.
KEY MESSAGE 2... MARGINAL RISK (LEVEL 1 OF 5) FOR ISOLATED SEVERE
STORMS ON WEDNESDAY.
ALOFT, A PAIR OF S/W DISTURBANCES WILL TRACK EWD ACROSS THE TN
VALLEY/DEEP SOUTH TUE NIGHT THEN CONTINUE ACROSS THE MID-
ATLANTIC/CAROLINAS ON WED AND OFFSHORE WED NIGHT, ALL WHILE THE
PARENT LOW SWINGS ACROSS ONTARIO, CANADA. THE LEADING DISTURBANCE
APPEARS TO BE ABOUT 3-6 HRS AHEAD AND FURTHER SOUTH THAN THE
TRAILING, NRN STREAM S/W. AT THE SURFACE, A WARM FRONT WILL LIFT
NEWD ACROSS CENTRAL NC AS A LOW TRACKS EWD ACROSS THE NRN MID-
ATLANTIC/NORTHEAST ON WED. THE TRAILING COLD FRONT SHOULD ALSO
PROGRESS EWD ACROSS THE APPALACHIANS ON WED AND CONTINUE ACROSS THE
AREA WED NIGHT AS THE PARENT LOW SHIFTS OFFSHORE OF NJ/NY. NOTE THE
TRACK OF THE PARENT LOW AND TIMING OF THE COLD FRONT STILL VARIES
FROM MODEL TO MODEL. THE 12Z NAM IS THE QUICKEST TO BRING THE FRONT
THROUGH (WED EVENING).
EXPECT SOME RAIN/SHOWERS LATE TUE NIGHT/WED MORN WITH THE LEADING
S/W DISTURBANCE AS THE WARM FRONT LIFTS NWD INTO THE AREA. THIS
EARLY PRECIPITATION COULD IMPACT THE AVAILABLE INSTABILITY WITH THE
TRAILING S/W AND THUS POTENTIAL FOR STORMS TO BECOME SEVERE. THE
TRAILING S/W SHOULD MOVE ACROSS AT A MORE FAVORED DIURNAL TIME, IF
EARLIER ACTIVITY DOES NOT LIMIT DESTABILIZATION. NAM FORECAST
SOUNDINGS SHOW DEEP LAYER SHEAR OF 40+ KTS WITH SBCAPE IN THE 500-
1000 J/KG RANGE WED AFT/EVE, WHILE THE GFS ALSO HAS 0-6 KM SHEAR OF
40+ KTS BUT SBCAPE LIMITED TO LESS THAN 300 J/KG OVER THE TRIAD,
WITH LITTLE IF ANY INSTABILITY NOTED ELSEWHERE. WILL HAVE TO MONITOR
HOW THIS EVOLVES IN THE COMING DAYS, BUT THERE IS AT LEAST A
CONDITIONAL THREAT FOR ISOLATED STRONG TO SEVERE STORMS ON WED
ACROSS CENTRAL NC AND A MARGINAL (LEVEL 1) RISK OF SEVERE STORMS IN
IN PLACE FROM THE SPC. BOTH THE 12Z NAM AND 06Z GFS SHOW A BRIEF
PERIOD OF 30-40 KT WINDS AT 925 MB, MAINLY ACROSS THE SOUTH, WED
MORN/EARLY AFT, SO IF THE EARLIER CONVECTION IS ABLE TO TAP INTO
THAT, THERE COULD BE SOME STRONGER GUSTS IN THAT RANGE WITH THEM.
KEY MESSAGE 3... STILL A CHANCE FOR MORE RAIN FRI-SUN.
THERE AREA STILL SOME TIMING/TRACK DIFFERENCES WITH THE NEXT WEATHER
SYSTEM AS IT MOVES ACROSS THE SRN CONUS LATE-WEEK INTO THE WEEKEND.
ALOFT, THE NRN STREAM LOW OVER SRN ONTARIO/NRN GREAT LAKES THU/FRI
SHOULD DRIFT SLOWLY EWD ACROSS THE NORTHEAST US/QUEBEC, CANADA
THROUGH THE WEEKEND. MEANWHILE, A SRN STREAM LOW IS EXPECTED TO MOVE
INLAND NEAR NRN BAJA/SRN CA THU/THU NIGHT AND SHOULD TRACK EWD INTO
THE SRN PLAINS BY FRI/FRI NIGHT. THE MODEL VARIABILITY INCREASES
SIGNIFICANTLY BEYOND FRI, WITH THE GFS SHOWING THE S/W GETTING
PICKED UP BY AND AMPLIFYING THE NRN STREAM TROUGH THEN EJECTING
QUICKLY NEWD INTO AND ACROSS THE REGION FRI NIGHT/SAT, WHILE THE EC
SOLUTION IS SLOWER AND LESS AMPLIFIED, WITH A SLIGHTLY FARTHER SOUTH
TRAJECTORY OF THE S/W ACROSS THE SOUTHEAST US SAT/SUN. FOR CENTRAL
NC THE GFS SOLUTION IS WET, WHILE THE EC IS DRY.
AVIATION /18Z MONDAY THROUGH SATURDAY/
AS OF 140 PM MONDAY...
HIGH PRESSURE WILL EXTEND ACROSS THE MIDDLE ATLANTIC THROUGH TUE AND
FAVOR PRIMARILY VFR CONDITIONS IN CNTL NC, WITH AN ENELY SURFACE
BREEZE THIS AFTERNOON THAT WILL VEER TO SSWLY TUE AFTERNOON. THE
EXCEPTION TO VFR WILL BE A CHANCE OF MVFR RESTRICTIONS AT INT/GSO
BETWEEN 12-18Z TUE, RELATED TO MOSTLY STRATIFORM RAIN AND OTHERWISE
MID-LEVEL CEILINGS REMNANT TO PREVIOUSLY-VIGOROUS, UPSTREAM
CONVECTION.
OUTLOOK: IFR-MVFR CEILINGS AND ANOTHER AREA OF MOSTLY STRATIFORM
RAIN ARE EXPECTED TO OVERSPREAD CNTL NC WED MORNING, FOLLOWED BY A
CHANCE OF SHOWERS AND STORMS ALONG A PASSING COLD FRONT DURING THE
LATE AFTERNOON AND EVENING. ANOTHER CHANCE OF FLIGHT RESTRICTIONS
AND RAIN WILL ACCOMPANY AN AREA OF LOW PRESSURE FORECAST TO TRACK
ACROSS OR JUST SOUTH OF THE CAROLINAS LATE FRI NIGHT-SAT.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MWS/KC
AVIATION...MWS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page