200
FXUS62 KRAH 040455
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
1255 AM EDT WED JUN 4 2025
SYNOPSIS
HIGH PRESSURE WILL EXTEND ACROSS NORTH CAROLINA THROUGH WEDNESDAY.
AN UPPER LEVEL LOW WILL THEN MOVE INTO THE CAROLINAS FROM THE
SOUTHWEST, BRINGING RAIN CHANCES WEDNESDAY NIGHT INTO EARLY FRIDAY.
NEAR TERM /THROUGH TONIGHT/
AS OF 940 PM TUESDAY...
* NEAR NORMAL TEMPERATURES TONIGHT WITH THE RETURN OF MOIST,
SOUTHERLY FLOW.
A 1024 MB SURFACE HIGH IS CURRENTLY LOCATED TO OUR EAST, OVER THE
ATLANTIC OCEAN. THIS WILL ALLOW FOR WARMER, MOIST AIR TO CONTINUE TO
SPREAD INTO THE REGION FROM THE ACCOMPANYING SOUTHERLY FLOW, RAISING
LOW TEMPERATURES FROM LAST NIGHT. HOWEVER, WENT ON THE LOW END OF
GUIDANCE DUE TO RADIATIONAL COOLING EXPECTED DUE TO CALM TO LIGHT
WINDS AND MOSTLY CLEAR SKIES. THUS, LOW TEMPERATURES TONIGHT ARE
EXPECTED IN THE LOW 60S, WITH MID-TO-UPPER 50S IN THE COOLEST SPOTS
IN THE NORTH. BY MORNING, THE HRRR SMOKE MODEL SHOWS THE POTENTIAL
FOR ANOTHER ROUND OF UPPER-LEVEL SMOKE TO PIVOT BACK INTO THE
REGION, MOSTLY IN THE SOUTH AND WESTERN PORTIONS OF THE CWA. ALONG
WITH THIS, CLOUD COVER IS EXPECTED TO START INCREASING BY MORNING
WITH A LAYER OF HIGH CLOUDS MOVING INTO THE REGION FROM THE SOUTH
AND A LAYER OF LOW CLOUDS DEVELOPING IN THE WESTERN AND SOUTHERN
PIEDMONT.
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 /06Z TUESDAY THROUGH SUNDAY/
AS OF 1255 AM WEDNESDAY...
CURRENT VFR CONDITIONS WILL HOLD THROUGH EARLY THIS EVENING AT
RDU/RWI/FAY, HOWEVER THERE IS A GOOD CHANCE FOR LOW CIGS TO SPREAD
NORTHWARD OVER THE S AND W PIEDMONT EARLY THIS MORNING, BRINGING A
GOOD CHANCE FOR MVFR TO IFR CIGS TO INT/GSO FROM 09Z TO 14Z. SOME
MODELS ARE SUGGESTING THAT CIGS COULD DROP TO LIFR AT INT/GSO, SO
WILL MONITOR FOR THAT POTENTIAL. THESE LOW CLOUDS SHOULD MIX OUT
WITH VFR CONDITIONS AREAWIDE AFTER 16Z TODAY, ALTHOUGH HIGH CLOUDS
WILL SPREAD IN FROM THE S DURING THE AFTERNOON, WITH LOWERING BASES
INTO THE MID LEVELS BY MID EVENING. AS SURFACE LOW PRESSURE TRACKS
TO OUR S AND SE WHILE UPPER LEVEL LOW PRESSURE MOVES SW TO NE INTO
THE CAROLINAS, AN AREA OF RAIN WILL SPREAD INTO CENTRAL NC, MAINLY
IN THE SE, FROM S TO N FROM MID-LATE EVENING THROUGH TONIGHT. THIS
WILL BRING A HIGH CHANCE FOR MVFR CIGS AND VSBYS AT FAY AFTER 03Z
AND RDU/RWI AFTER 05Z, WITH FAY POSSIBLE DROPPING TO IFR AFTER 05Z.
THESE ADVERSE AVIATION CONDITIONS SHOULD HOLD SE OF INT/GSO TO THE
END OF THE TAF PERIOD AT 06Z. SURFACE WINDS WILL STAY LIGHT, UNDER
10 KT, FROM THE S TO SE THIS MORNING BEFORE SHIFTING GRADUALLY TO BE
MAINLY FROM THE SE AND E THROUGH TONIGHT.
LOOKING BEYOND 06Z THU, SUB-VFR CONDITIONS AND RAIN WILL CONTINUE TO
OVERSPREAD ALL OF CENTRAL NC OVERNIGHT, DOMINATING AT ALL SITES FROM
LATE TONIGHT THROUGH THU EVENING, WITH THE HIGHEST RAIN CHANCES IN
THE E (FAY/RWI INTO RDU). SUB-VFR CONDITIONS WILL CLEAR OUT W TO E
THU NIGHT BUT ARE LIKELY TO PERSIST THROUGH SUNRISE FRI AT RWI. A
BRIEF LULL IN RAIN CHANCES IS EXPECTED MUCH OF FRI, THEN AS A COLD
FRONT APPROACHES FROM THE NW, A BETTER CHANCE FOR SHOWERS AND STORMS
ARRIVES SAT, LASTING THROUGH SUN IN THE E, WITH A RISK FOR EARLY-
MORNING FOG EACH DAY IN THE E. -GIH
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...HARTFIELD
NEAR TERM...HELOCK
SHORT TERM...LEINS
LONG TERM...LUCHETTI
AVIATION...HARTFIELD
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