683
FXUS62 KRAH 150712
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
312 AM EDT THU OCT 15 2026
WHAT HAS CHANGED
* FORECAST CONFIDENCE FOR RAIN CONTINUES TO INCREASE FOR FRI NIGHT-
SAT, THOUGH CONSIDERABLE UNCERTAINTY IN RAINFALL AMOUNTS AND
DURATION REMAIN.
KEY MESSAGES
AS OF 300 AM THURSDAY...
1) RECORD HEAT WILL CONTINUE THROUGH FRIDAY.
2) A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL NC FRIDAY EVENING,
WITH A SIGNIFICANT COOLDOWN FOR THE WEEKEND. THERE IS STILL SOME
POTENTIAL FOR PATCHY FROST, BUT FORECAST UNCERTAINTY HAS INCREASED.
DISCUSSION
AS OF 300 AM THURSDAY...
KEY MESSAGE 1... RECORD HEAT WILL CONTINUE THROUGH FRIDAY.
AN ANOMALOUSLY STRONG SUB-TROPICAL RIDGE CENTERED IN 00Z/15TH UPR
AIR DATA OVER THE TN VALLEY, WITH STANDARDIZED 500 MB HEIGHT
ANOMALIES ~2 SIGMA, WILL PROGRESS EWD AND OFF THE SOUTH ATLANTIC
COAST THROUGH 12Z FRI. ON THE NRN PERIPHERY OF THAT RIDGE, SERIES OF
MCVS FROM DISSIPATED OR WEAKENING CONVECTION FROM THE DELMARVA TO
NRN MIDDLE TN WILL PROGRESS GENERALLY EWD AND ACROSS THE SRN MIDDLE
ATLANTIC TODAY. DEEP LAYER FLOW WILL THEN STRENGTHEN AND BACK TO
SWLY AHEAD OF AN INTENSE, POSITIVELY-TILTED, FULL LATITUDE, AND
INCREASINGLY-PHASED TROUGH --ONE COMPRISED OF A SRN STREAM CYCLONE
NOW OVER CO AND A VIGOROUS NRN STREAM SHORTWAVE TROUGH OVER MB--
FORECAST TO STRETCH FROM WRN QC TO THE LWR MS VALLEY BY 00Z SAT.
AT THE SURFACE, AN OUTFLOW BOUNDARY/WIND SHIFT ACROSS THE VIRGINIAS
AND LWR OH VALLEY, RELATED TO THE AFOREMENTIONED DISSIPATED OR
WEAKENING CONVECTION THERE, WILL DRIFT SSEWD AND PROBABLY ACROSS THE
NRN PIEDMONT AND NRN COASTAL PLAIN OF NC BY LATE THIS MORNING-
MIDDAY. A SYNOPTIC FRONT LAGS THE OUTFLOW AND WAS ANALYZED AT 07Z
FROM N-CNTL DE THROUGH NRN VA AND CNTL WV. WHILE THIS BOUNDARY WILL
ALSO MOVE GENERALLY SWD AND IN BACKDOOR FASHION ACROSS VA THIS
MORNING, IT WILL LIKELY NOT MOVE INTO THE NE PIEDMONT AND NRN
COASTAL PLAIN OF NC UNTIL LATER THIS AFTERNOON AND EVENING, WHERE IT
WILL BRIEFLY STALL. THE FRONT WILL THEN RETREAT NWD LATER TONIGHT
AND FRI, AS MASS RESPONSE STRENGTHENS AHEAD OF THE INTENSE TROUGH
ALOFT AND A RELATED SURFACE CYCLONE FORECAST TO DEEPEN CONSIDERABLY
WHILE TRACKING ACROSS THE GREAT LAKES AND NORTHEAST ON FRI.
TEMPERATURES TODAY WILL BE GENERALLY PERSISTENCE ONES EQUATORWARD OF
THE APPROACHING SYNOPTIC FRONT, WHICH WILL OFFER COOLING THROUGHOUT
VA AND ONLY INTO THE FAR NE PIEDMONT AND NRN COASTAL PLAIN OF NC.
WHILE HEIGHTS THROUGHOUT THE COLUMN WILL FALL AHEAD OF THE
APPROACHING TROUGH ALOFT ON FRI, RELATED COOLING WILL BE LIMITED
OVER CNTL NC UNTIL LATE IN THE DAY AND MORE-SO FRI NIGHT. AS SUCH,
TEMPERATURES ON FRI WILL AGAIN BE NEAR PERSISTENCE ONES, TO PERHAPS
A COUPLE OF DEGREES LOWER THAN PREVIOUS DAYS' WARM SECTOR ONES. A
GUSTY SWLY SURFACE WIND MAY TAKE A LITTLE EDGE OFF THE HEAT WHILE
ALSO BOOSTING THE TEMPERATURE AT RDU TO, OR WITHIN A DEGREE OF, THE
LATEST 90 DEGREE DAY AND PROBABLY THE THIRD CONSECUTIVE IN THIS
STRETCH, PROVIDED THE BACKDOOR FRONT HOLDS NORTH OF RDU AS EXPECTED
TODAY.
KEY MESSAGE 2... A STRONG COLD FRONT WILL SWEEP ACROSS CENTRAL NC
FRIDAY EVENING, WITH A SIGNIFICANT COOLDOWN FOR THE WEEKEND. THERE
IS STILL SOME POTENTIAL FOR PATCHY FROST, BUT FORECAST UNCERTAINTY
HAS INCREASED.
ALOFT, A POTENT NRN STREAM S/W WILL DROP INTO THE UPPER MS VALLEY
AND TRACK SEWD ACROSS THE GREAT LAKES THU AND FRI, DEEPENING THE
TROUGH OVER THE ERN US AS IT INTERACTS WITH ANOTHER S/W EJECTING
ENEWD FROM THE CNTL ROCKIES TO THE GREAT LAKES THU/THU NIGHT. THE
POSITIVELY TILTED TROUGH WILL CONTINUE TO AMPLIFY AS IT MOVES EWD
ACROSS THE EASTERN US AND OFFSHORE OVER THE WEEKEND. MODEL SPREAD
HAS INCREASED FROM SAT ONWARD, WITH SOME MORE RECENT GUIDANCE
SHOWING A LOW DEVELOPING WITHIN THE TROUGH OVER THE CAROLINAS
SAT/SAT NIGHT, POSSIBLY LINGERING OVER THE REGION FOR AWHILE,
SLOWING THE TROUGHS EWD PROGRESSION, WHILE OTHERS DEVELOP A LOW
OFFSHORE. AT THE SURFACE, AN AREA OF LOW PRESSURE LIFTING NEWD
ACROSS THE MID-MS AND OH VALLEY ON THU WILL DEEPEN AS IT CONTINUES
ACROSS THE GREAT LAKES AND NORTHEAST US THU NIGHT/FRI. THE TRAILING
COLD FRONT WILL MOVE ACROSS CENTRAL NC LATE FRI EVENING INTO FRI
NIGHT, CURRENTLY PROGGED TO BE MOVING INTO THE NW PIEDMONT AROUND
00Z SAT. A ~1037 MB CANADIAN HIGH CENTERED OVER THE S-CNTL PLAINS ON
SAT WILL BUILD INTO THE REGION IN THE WAKE OF THE FRONT AS IT TRACKS
NEWD ACROSS THE MID-MS AND OH VALLEY REGIONS ON SAT. THERE IS SOME
UNCERTAINTY BEYOND SAT, WITH SOME MODELS SHOWING A COASTAL LOW
DEVELOPING AS ALONG THE FRONT AS IT MOVES OFFSHORE, WHILE OTHERS
SHOW A MORE PROGRESSIVE FRONT CONTINUE EWD OVER THE ATLANTIC. THE
LATTER SOLUTION WOULD ALLOW THE HIGH TO SETTLE OVER THE MID-
ATLANTIC, WHILE THE FORMER WOULD TAKE THE HIGH ENEWD ACROSS THE NRN
MID-ATLANTIC/NORTHEAST US ON SUN.
THE VARYING SOLUTIONS NOTED ABOVE WILL IMPACT NUMEROUS WEATHER
PARAMETERS (TEMPS, WINDS, PRECIP, ETC.), RESULTING IN A LOW-
CONFIDENCE FORECAST SAT NIGHT ONWARD.
THE CHANCE FOR RAIN CONTINUES TO INCREASE, AS DOES THE DURATION,
COVERAGE, AND UNCERTAINTY. FORECAST AMOUNTS ARE STILL SOMEWHAT
LIGHT, WITH GENERALLY A QUARTER OF AN INCH OR LESS EXPECTED FRI
NIGHT THROUGH SAT NIGHT. THE LOW-LEVEL JET IS EXPECTED TO STRENGTHEN
OVER THE AREA FRI EVE, WITH 25-35 KTS AT 925MB. THE PRESSURE
GRADIENT WILL ALSO BE QUITE STRONG AS A ~1037 MB HIGH BUILDS EWD.
EXPECT GUSTY WINDS WITH AND BEHIND THE FRONT FRI EVE THROUGH SAT.
TEMPERATURES SHOULD FALL ABOUT 25-30 DEGREES FROM FRIDAY AFT TO SAT
MORNING. BY SATURDAY, HIGHS WILL BE SIMILAR TO THE LOWS FROM THU
NIGHT (GENERALLY LOW TO MID 60S). KEEPING IN MIND THE FORECAST
UNCERTAINTY NOTED ABOVE, LOWS MAY DROP ANOTHER 10-15 DEGREES OR SO
SAT NIGHT, AS COLD AIR ADVECTS INTO THE AREA. FOR NOW EXPECT LOWS TO
RANGE FROM UPPER 30S NW TO MID/UPR 40S SE BOTH SAT NIGHT AND SUN
NIGHT. HOWEVER, IF THE MORE PROGRESSIVE SOLUTIONS VERIFY THERE COULD
BE SOME MID 30S LOWS OVER PORTIONS OF THE PIEDMONT BOTH NIGHTS,
POSSIBLY RESULTING IN SOME PATCHY FROST IN THE USUAL COOLER,
SHELTERED AREAS.
AVIATION /06Z THURSDAY THROUGH MONDAY/
AS OF 155 AM THURSDAY...
LIGHT SWLY WINDS WILL PERSIST AHEAD OF AN OUTFLOW BOUNDARY THAT MAY
SHIFT SURFACE WINDS TO LIGHT NELY/ELY AT PIEDMONT SITES AND RWI LATE
THIS MORNING. THAT BOUNDARY WILL BE FOLLOWED BY A BACKDOOR COLD
FRONT THAT WILL SETTLE INTO THE FAR NE PIEDMONT AND NRN COASTAL
PLAIN OF NC LATE THIS AFTERNOON OR THIS EVENING. IFR-MVFR CEILINGS
ARE LIKELY TO DEVELOP BEHIND THAT FRONT, INCLUDING AT RWI, NEAR THE
END OF THE 06Z TAF PERIOD. WHILE THE FRONT AND POST-FRONTAL CEILINGS
ARE LIKELY TO HOLD JUST TO THE NORTH OF PIEDMONT SITES, BY PERHAPS
10-30 MILES, A SLIGHT SWWD SHIFT OF THE LOCATION OF THE BOUNDARY
WOULD RESULT IN AN INCREASING LIKELIHOOD FOR FLIGHT RESTRICTIONS AT
PIEDMONT SITES TONIGHT AS WELL.
OUTLOOK: GUSTY SWLY SURFACE WINDS WILL DEVELOP AHEAD OF A STRONG
COLD FRONT ON FRI, FOLLOWED BY A PERIOD OF STRONG AND GUSTY NWLY
SURFACE WINDS WITH THE PASSAGE OF THAT FRONT FRI NIGHT. THERE IS A
CHANCE THAT THE FRONT WILL BE ACCOMPANIED BY A SHALLOW, BROKEN LINE
OF CONVECTION (DEVOID OF LIGHTNING) AS IT MOVES ACROSS CNTL NC FRI
NIGHT, FOLLOWED BY AN AREA OF POST-FRONTAL, STRATIFORM RAIN THAT MAY
LINGER INTO THE DAY SAT.
CLIMATE
RECORD HIGH TEMPERATURES:
OCTOBER 15:
KGSO: 87/1985
KRDU: 88/1985
KFAY: 91/1931
OCTOBER 16:
KGSO: 85/1953
KRDU: 86/1925
KFAY: 90/1925
RECORD HIGH MINIMUM TEMPERATURES:
OCTOBER 15:
KGSO: 63/1985
KRDU: 66/1942
KFAY: 67/1928
OCTOBER 16:
KGSO: 66/1947
LATEST 90 F DAYS:
GSO: 10/12/1904
RDU: 10/10/1907
FAY: 10/26/1940
RAH WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...MWS/KC
AVIATION...MWS
CLIMATE...RAH
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