920
FXUS62 KRAH 031958
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
358 PM EDT TUE JUN 3 2025
SYNOPSIS
HIGH PRESSURE OFF THE MIDDLE ATLANTIC COAST WILL EXTEND WESTWARD
INTO NC THROUGH WEDNESDAY. MEANWHILE, AN AREA OF LOW PRESSURE WILL
DEVELOP OFF THE SOUTHEAST U.S. COAST, THEN MOVE SLOWLY NORTHEAST
ALONG THE COAST OF THE CAROLINAS WEDNESDAY NIGHT THROUGH FRIDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 355 PM TUESDAY...
A MID-LEVEL ANTICYCLONE CENTERED OVER THE CAROLINAS IN 12Z UPR AIR
DATA WILL DRIFT EWD AND OFFSHORE THROUGH 12Z WED, WHILE A MID/UPR-
LEVEL CYCLONE WILL MEANDER OVER THE NERN GULF AND TOWARD THE FL
PANHANDLE.
AT THE SURFACE, ~1024 MB, CONTINENTAL-SOURCED HIGH PRESSURE NOW
CENTERED ABOUT A HUNDRED MILES EAST OF THE OUTER BANKS WILL DRIFT
EWD, WHILE ITS ASSOCIATED RIDGE AXIS WILL CONTINUE TO EXTEND WWD
INTO THE SRN MIDDLE ATLANTIC. THE INFLUENCE OF THE ASSOCIATED DRY
AIR RIDGE HAS MANIFESTED AS A MIXING OUT OF SURFACE DEWPOINTS INTO
THE 40S F THIS AFTERNOON OVER PORTIONS OF THE NC SANDHILLS AND
COASTAL PLAIN.
GOES VISIBLE SATELLITE AND AEROSOL OPTICAL DEPTH DATA CONTINUE TO
INDICATE THE GREATEST CONCENTRATION OF CANADIAN WILDFIRE SMOKE
REMAINS THIS AFTERNOON FROM THE LWR GREAT LAKES TO ALONG AND JUST
OFFSHORE THE OUTER BANKS, BUT SOME ALSO REMAINS EVIDENT IN THOSE
PRODUCTS AND AS HAZY SKIES IN AREA WEBCAMS THROUGHOUT CNTL NC. ASIDE
FROM THAT HAZE, AND PATCHES OF 5-6 THOUSAND FT AGL FAIR WEATHER
CUMULUS THAT WILL DISSIPATE WITH LOSS OF AFTERNOON HEATING, SKY
CONDITIONS WILL BE MAINLY CLEAR IN CNTL NC FOR MOST OF THE NIGHT.
THERE WILL, HOWEVER, BE A GRADUAL EARLY MORNING INCREASE IN THIN
CIRROSTRATUS NOW SLOWLY CREEPING NWD ALONG THE SOUTH ATLANTIC COAST,
IN ADVANCE OF THE MEANDERING CYCLONE OVER THE NERN GULF. THE MODELS
ALSO INDICATE AN AREA OF LOW OVERCAST WILL DEVELOP ACROSS THE SRN
AND WRN NC PIEDMONT WED MORNING, THOUGH THE RESIDUAL, CONTINENTAL
DRYNESS OF THE AIRMASS IN PLACE CALLS IN TO QUESTION JUST HOW
EXTENSIVE IT MAY BE, IF IT WERE TO DEVELOP AT ALL. CALM TO
OCCASIONAL LIGHT SLY STIRRING IN THE PRESENCE OF THE DRY AIR
(SURFACE) RIDGE AXIS WILL OTHERWISE FAVOR STRONG RADIATIONAL COOLING
AND LOW TEMPERATURES IN THE MID 50S TO LWR 60S.
SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/
AS OF 332 PM TUESDAY...
* DRY WEDNESDAY, WITH RAIN CHANCES RETURNING WEDNESDAY NIGHT
WEDNESDAY IS SHAPING UP TO BE A TRANSITION DAY ACROSS THE AREA. THE
DAY WILL START OFF WITH SURFACE HIGH PRESSURE WELL OFF THE NC COAST
AND PARTLY TO MOSTLY SUNNY SKIES ACROSS THE REGION. HOWEVER THE
SURFACE RIDGE WILL GRADUALLY MOVE OFFSHORE DURING THE AFTERNOON
HOURS IN ADVANCE OF A DEVELOPING COASTAL WAVE OFF THE FL/GA COAST.
INCREASING MID AND HIGH CLOUDS WILL BE PRESENT THROUGHOUT THE
AFTERNOON AND EVENING HOURS, PERHAPS KEEPING WARMER TEMPERATURES AT
BAY IN THE PROCESS. LOOK FOR DAYTIME HIGHS TO REACH THE MID TO UPPER
80S THROUGH FILTERED SUNSHINE.
TODAY'S 00Z ENSEMBLE CLUSTER ANALYSIS MAINTAINS THE IDEA OF
INCREASING PRECIP CHANCES ASSOCIATED WITH THE DEVELOPING COASTAL
LOW. HOWEVER SOME OF THE TRADITIONAL ENSEMBLE MEAN DEPICTIONS ARE
SKEWED TOWARD THE FASTER GEFS WHICH WANTS TO BRING PRECIP ALL THE
WAY THROUGH NC BY DAYBREAK THURSDAY, WHEREAS THE EC/EPS MEMBERS ARE
MUCH SLOWER AND HOLD OFF PRECIP UNTIL AFTER 12Z THURSDAY. NATURALLY
WOULD APPEAR MUCH OF THE INITIAL SATURATION WILL TAKE PLACE
WEDNESDAY NIGHT IN THE MID/UPPER LEVELS, WITH FORECAST PROFILES
INCREASINGLY TIGHTENING UP CLOSER TO DAYBREAK. RAINFALL IS CERTAINLY
PLAUSIBLE EARLY THURSDAY MORNING BEFORE 12Z, HOWEVER THE HIGHEST
CHANCES WOULD BE LOCATED ACROSS THE SANDHILLS/SOUTHERN COASTAL
PLAIN, WITH MUCH LOWER VALUES ALONG THE NC/VA BORDER. WILL MAINTAIN
A GRADIENT OF 20-40 POPS ACROSS THE AREA, WITH HIGHER VALUES WAITING
UNTIL THE DAYTIME HOURS.
WITH INCREASING CLOUD AND DEWPOINTS, LOW TEMPS WILL BE A BIT MORE
MILD AND CLOSER TO EARLY JUNE NORMALS WITH VALUES IN THE MID 60S.
LONG TERM /THURSDAY THROUGH TUESDAY/
AS OF 145 PM TUESDAY...
UPPER PATTERN THROUGH THE EXTENDED: AN UPPER LOW CENTERED OVER THE
GULF WILL WEAKEN INTO AN OPEN WAVE THAT GRADUALLY LIFTS NORTH ALONG
THE SOUTHEAST COAST THURSDAY THROUGH FRIDAY. BEHIND THIS DEPARTING
UPPER WAVE, A STRONG LONG-WAVE TROUGH WILL LIFT ACROSS THE EASTERN
SEABOARD SATURDAY AND LINGER THROUGH EARLY NEXT WEEK.
THURSDAY THROUGH FRIDAY: MID-LEVEL VORTICITY ASSOCIATED WITH THE
UPPER WAVE MENTIONED ABOVE (FROM THE GULF) WILL STREAM NORTHWARD ON
THURSDAY. AN ASSOCIATED PLUME OF LOW-LEVEL ANOMALOUS MOISTURE AND A
SFC WAVE/LOW WILL SLOWLY MIGRATE UP THE GA/SC COASTLINE. LATEST
GUIDANCE CONTINUES TO TREND TOWARDS AN EARLIER ARRIVAL OF RAIN EARLY
THURSDAY, WITH HIGHEST CHANCES IN OUR SOUTHERN COASTAL PLAIN THROUGH
FRIDAY MORNING. HOWEVER, THERE'S SOME UNCERTAINTY WRT TO HOW MUCH
RAIN WE MAY SEE FROM THIS SYSTEM, AS SOME GUIDANCE KEEPS THE SFC LOW
AND HIGHLY ANOMALOUS MOISTURE (PWAT OF ~1.5 TO 2 INCHES; ~140% OF
NORMAL) ALONG THE COASTAL AREAS. OTHER GUIDANCE TREKS THE LOW AND
DEEP MOISTURE FURTHER INLAND. LOOKING AT ENSEMBLE OUTPUT, THE
DIFFERENCE BETWEEN THE 90TH PERCENTILE AND 10TH PERCENTILE IS
ANYWHERE FROM 1 AND 1.5 INCHES (WITH ENSEMBLE MEAN QPF OF A HALF
INCH TO AN INCH IN THE SOUTHEAST). THUS, THERE IS STILL A BIT OF
UNCERTAINTY WRT TO THE TRACK OF THE WAVE/LOW AND HOW MUCH RAIN WE
MIGHT SEE. REGARDLESS, IT DOES APPEAR THAT ANY HAZARDS RELATED TO
THIS THURSDAY SYSTEM WOULD LIKELY BE POSSIBLE LOW-END CHANCE FOR
FLOODING IN OUR COASTAL PLAIN AREAS AT THIS POINT. GIVEN NELY FLOW,
CLOUDS, AND RAINY CONDITIONS, TEMPERATURES ON THURSDAY MAY BE A BIT
LOWER IN THE UPPER 70S/LOWER 80S. THE BULK OF THE RAIN SHOULD MOVE
TO EAST BY FRIDAY MORNING. WHILE MID-LEVEL RIDGING WILL RE-ESTABLISH
ITSELF ON FRIDAY, WILL MAINTAIN SLIGHT CHANCE POPS IN THE AFTERNOON
FOR ANY POSSIBLE SEA-BREEZE/DIURNAL CONVECTION. HIGHS PEAK BACK UP
INTO THE LOWER TO MID 80S FRIDAY.
SATURDAY THROUGH TUESDAY: THERE'S SOME DETAILS TO BE FLUSHED OUT,
BUT GENERALLY SPEAKING, EXPECT HOT AND WET CONDITIONS TO PERSIST
THROUGH THIS PERIOD. THE AFOREMENTIONED UPPER TROUGH WILL LIFT
ACROSS THE EAST COAST AND LINGER THROUGH MONDAY. AS SUCH, PERIODS OF
SHOWERS AND STORMS ARE POSSIBLE DURING THIS PERIOD. MACHINE
LEARNING OUTLOOKS CONTINUE TO SUGGEST AT LEAST MARGINAL-EQUIVALENT
PROBABILITIES FOR SEVERE WEATHER ON SATURDAY. HOWEVER, MID-LEVEL
HEIGHT FALLS AREN'T OVERLY IMPRESSIVE IN THE DETERMINISTIC GUIDANCE.
NEITHER IS SIMULATED BULK-LAYER SHEAR. THIS COULD ULTIMATELY CHANGE
AS WE GET CLOSER TO SATURDAY, BUT FOR NOW NOT OVERLY IMPRESSED WITH
THE KINEMATIC SPACE FOR SVR WEATHER. SHOWER AND STORM CHANCES WILL
CONTINUE THROUGH TUESDAY AS THE UPPER TROUGH LINGERS AND ADDITIONAL
EMBEDDED SHORT-WAVES MOVE OVER THE SOUTHEAST. TEMPERATURES WILL
PEAK EACH DAY IN THE MID TO UPPER 80S.
AVIATION /18Z TUESDAY THROUGH SUNDAY/
AS OF 205 PM TUESDAY...
GRADUAL MOISTURE RETURN/RECOVERY, AROUND THE WRN PERIPHERY OF HIGH
PRESSURE OFF THE MIDDLE ATLANTIC COAST, WILL FAVOR THE DEVELOPMENT
OF IFR-MVFR CEILINGS ACROSS THE SRN AND WRN NC PIEDMONT WED MORNING,
INCLUDING AT INT/GSO. ADDITIONALLY, SHALLOW, PRE-DAWN RADIATION FOG
WILL AGAIN BE POSSIBLE AT RWI. SURFACE WINDS WILL BE OPERATIONALLY
INSIGNIFICANT AND GENERALLY LIGHT SLY, TO CALM TONIGHT MAINLY AT
RWI.
OUTLOOK: AN AREA OF LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST U.S.
COAST AND MOVE SLOWLY NORTHEAST ALONG THE COAST OF THE CAROLINAS
WEDNESDAY NIGHT THROUGH FRIDAY, DURING WHICH TIME RAIN AND FLIGHT
RESTRICTIONS WILL BE POSSIBLE, MOST LIKELY AND PROLONGED, AND
LOWEST, AT FAY AND RWI. A GOOD CHANCE OF SHOWERS/STORMS WILL
ACCOMPANY A FRONTAL ZONE THAT WILL SETTLE INTO AND LINGER OVER NC
THIS WEEKEND.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...MWS
NEAR TERM...MWS
SHORT TERM...LEINS
LONG TERM...LUCHETTI
AVIATION...MWS
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