903
FXUS62 KRAH 080611
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
210 AM EDT THU OCT 8 2026
WHAT HAS CHANGED
* THE FORECAST MOVEMENT OF ISAIAS HAS STABILIZED WHICH CONTINUES TO
SUPPORT IN WIDESPREAD SHOWERS INCREASING FROM THE SW BY LATE
SATURDAY AND CONTINUE INTO EARLY SUNDAY. A FEW THUNDERSTORMS ARE
POSSIBLE EARLY SUNDAY. RAPID CLEARING IN THE REAR OF THE SYSTEM
IS EXPECTED SUNDAY.
* STORM TOTAL RAINFALL AMOUNTS HAVE ALSO STABILIZED AND ARE
GENERALLY STILL EXPECTED IN THE RANGE OF 1 TO 2 INCHES WITH
LOCALLY HIGHER AMOUNTS ACROSS THE COASTAL PLAIN AND TUCKED
UP AGAINST THE BLUE RIDGE FOOTHILLS INTO THE MOUNTAINS.
KEY MESSAGES
AS OF 210 AM THURSDAY...
1) ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH FRIDAY.
2) THE LIKELIHOOD OF UNSETTLED WEATHER AND SIGNIFICANT RAIN
ASSOCIATED WITH ISAIAS CONTINUES TO INCREASE FOR LATE SATURDAY
THROUGH EARLY SUNDAY.
DISCUSSION
AS OF 210 AM THURSDAY...
KEY MESSAGE 1... ABOVE NORMAL TEMPERATURES ARE EXPECTED THROUGH
FRIDAY.
A MOISTURE-STARVED COLD FRONT WILL MOVE THROUGH THE REGION TONIGHT
INTO EARLY FRIDAY. AHEAD OF THE FRONT, WEAK DOWNSLOPE WINDS AND
RISING LOW-LEVEL THICKNESSES WILL PROPEL AFTERNOON HIGHS SOME 6-10
DEGREES ABOVE NORMAL IN THE LOWER TO MIDDLE 80S.
BEHIND THE FRONT, COOLER HIGH PRESSURE SETTLES IN FRIDAY, GRADUALLY
STRENGTHENING INTO SATURDAY OVER THE MID-ATLANTIC REGION. NORTHEAST
FLOW TOMORROW WILL PROMOTE LOWER DAYTIME HIGHS BUT STILL A FEW
DEGREES ABOVE AVERAGE IN THE MID TO UPPER 70S. DEWPOINTS WILL BE A
TOUCH HIGHER TODAY, BUT DRIER AIR WORKS IN BEHIND THE FRONT FRIDAY
FOR ANOTHER COMFORTABLE AFTERNOON AS DEWPOINTS DROP INTO THE 40S
OVER MOST OF CENTRAL NC.
KEY MESSAGE 2... THE LIKELIHOOD OF UNSETTLED WEATHER AND SIGNIFICANT
RAIN ASSOCIATED WITH ISAIAS CONTINUES TO INCREASE FOR LATE SATURDAY
THROUGH EARLY SUNDAY. RAPID CLEARING IN THE REAR OF THE SYSTEM
SUNDAY.
TROPICAL STORM ISAIAS IS FORECAST TO QUICKLY STRENGTHEN INTO A
HURRICANE ON THURSDAY, MOVE ASHORE ON THE NORTHERN GULF COAST FRIDAY
NIGHT NEAR MS/AL/WESTERN FL, WITH THE SYSTEM CENTER TURNING NNW
SATURDAY AND SATURDAY NIGHT. THIS IS A BIT WEST OF THE PREVIOUS
TRACK FORECASTS AS ONCE THE SYSTEM WEAKENS OVER LAND, IT WILL GET
PULLED INTO THE UPPER LOW OVER THE MID-MS VALLEY REGION THEN.
FINALLY, THE REMNANT LOW SHOULD TURN NE THROUGH THE OH VALLEY LATE
IN THE WEEKEND.
THE TIMING OF SHOWERS FOR CENTRAL NC CONTINUES TO FOCUS ON LATE
SATURDAY INTO SATURDAY NIGHT AND SUNDAY. WE WILL LIKELY HAVE THE
LARGE SURFACE HIGH SHIFT EAST AND OFF THE NEW ENGLAND COAST SATURDAY
NIGHT AND SUNDAY AS THE TROPICAL CYCLONE WEAKENS TO A DEPRESSION AND
REMNANT LOW. AS THIS OCCURS, SHOWERS ARE EXPECTED OVER THE FAR
SOUTHERN AND WESTERN AREAS THAT WILL LIKELY SET UP A CAD EVENT BY
SATURDAY NIGHT. A COASTAL FRONT IS EXPECTED ALONG THE SE US, AND
THIS WILL LIKELY GET PULLED INLAND (NW) INTO SC AND FAR SE NC ON
SATURDAY NIGHT. CENTRAL NC MAY HAVE TO RELY ON A SECONDARY LOW
PRESSURE TO FORM ALONG THIS BOUNDARY FOR THE MOST SIGNIFICANT RAIN
LATE SATURDAY NIGHT AND SUNDAY MORNING. IN AN INTERESTING TWIST, THE
NW PIEDMONT MAY AGAIN HAVE A MINIMUM IN QPF WITH THIS EVENT WITH THE
EXPECTED CAD IN THAT REGION. THE ESE UPSLOPE FLOW INTO THE BLUE
RIDGE SHOULD LEAD TO A MAXIMUM THERE. AND, THE COASTAL FRONT'S
SECONDARY LOW SHOULD LEAD TO A MAXIMUM OF QPF OVER THE COASTAL PLAIN
AND MAYBE THE EASTERN PIEDMONT. OVERALL, 0.5 TO 1 INCH STORM TOTALS
IN THE NW PIEDMONT AND 1-2 INCHES ELSEWHERE.
SHOWERS SHOULD TAPER OFF AND END QUICKLY ON SUNDAY WITH THE DRY SLOT
AND THE SINKING/DOWNSLOPE FLOW IN THE REAR OF THE SYSTEM AS IT
DEPARTS TO OUR N-NE. SUNSHINE AND WARMTH WILL LIKELY RETURN
LATER SUNDAY.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 1245 AM THURSDAY...
MOSTLY VFR CONDITIONS ARE EXPECTED TO PREVAIL AT THE TAF SITES
THROUGH THE 24-HOUR PERIOD. THE ONE EXCEPTION IS THE POTENTIAL FOR
SHALLOW GROUND FOG AT A FEW SITES, NAMELY INT/RWI AND POSSIBLY FAY.
THE LAST FEW RUNS OF SOME HIGH-RES GUIDANCE, NAMELY THE
HRRR/RRFS/REFS, SUGGEST THIS POTENTIAL. CROSSOVER TEMPERATURES ARE
SOMEWHAT FAVORABLE NEAR THE MIDDLE 50S AT INT, BUT LOW TEMPERATURES
MAY JUST BE SHY OF CROSSOVER. HOWEVER, GIVEN CLEAR SKIES, OPTED TO
INTRODUCE A BRIEF MVFR RESTRICTION INTO THU MORNING. WE KEPT THE
SAME BRIEF RESTRICTION AT RWI BASED ON PERSISTENCE, THOUGH CROSSOVER
TEMPERATURES MAY BE SOMEWHAT LESS FAVORABLE AS EARLIER SHIFTS NOTED.
LIGHT WINDS WILL BECOME WEST TO NORTHWEST THU AFTERNOON AT 5-8 KT. A
FEW BRIEF GUSTS TO 15 KT ARE POSSIBLE OVER THE TRIAD TERMINALS.
OUTLOOK: RAIN AND FLIGHT RESTRICTIONS, AND COLD AIR DAMMING, ARE
LIKELY TO DEVELOP ACROSS CNTL NC LATE SAT INTO SUN. ALTHOUGH THERE
REMAINS TIMING/DURATION UNCERTAINTY OF THOSE IMPACTS, THE HEAVIEST
RAIN WILL PROBABLY TAPER OFF TO LIGHTER RAIN/MIST/DRIZZLE OVER THE
PIEDMONT ON SUNDAY, WHERE COLD AIR DAMMING WILL BE MOST LIKELY TO
CONTINUE. THE CAD REGIME MAY BE ERODED BY THE PASSAGE OF A
WARM/WEDGE FRONT OVER PARTS OF ESPECIALLY SERN NC, INCLUDING NEAR
FAY, WHERE BOTH A LIFTING/SCATTERING TO VFR AND DEVELOPMENT OF
CONVECTIVE PRECIPITATION WILL BE POSSIBLE SUNDAY AFTERNOON. FLIGHT
RESTRICTIONS IN CAD MAY REMAIN OVER THE PIEDMONT THROUGH MON MORNING.
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...KREN/BADGETT
AVIATION...KREN/MWS
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