152
FXUS62 KRAH 181017
AFDRAH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RALEIGH NC
618 AM EDT THU JUN 18 2026
WHAT HAS CHANGED
* HEAT ADVISORY ISSUED FOR THE TRIANGLE, EASTERN PIEDMONT,
SANDHILLS, AND COASTAL PLAIN FROM 11 AM TO 8 PM TODAY.
KEY MESSAGES
AS OF 222 AM THURSDAY...
1) HEAT ADVISORY IN EFFECT TODAY FOR THE EASTERN PIEDMONT,
SANDHILLS, AND COASTAL PLAIN.
2) A CONDITIONAL THREAT FOR STRONG TO SEVERE STORMS CAPABLE OF
PRODUCING DAMAGING STRAIGHT-LINE WIND GUSTS REMAINS THIS AFTERNOON
AND EVENING, WITH GREATEST CHANCES FOR SHOWERS/STORMS LATE TONIGHT
INTO FRIDAY.
3) INCREASED FIRE DANGER TODAY AS STRONG GUSTY WINDS AND HOT
TEMPERATURES OVERLAP WITH CRITICALLY DRY, DROUGHT-CURED FUELS.
DISCUSSION
AS OF 222 AM THURSDAY...
KEY MESSAGE 1... HEAT ADVISORY IN EFFECT TODAY FOR THE EASTERN
PIEDMONT, SANDHILLS, AND COASTAL PLAIN.
A HOT, MOIST, AND WINDY DAY WILL BE IN PLACE TODAY AS BROAD
SOUTHWEST FLOW AND VERY WARM TEMPERATURES IN THE LOW-LEVELS FAVOR
RECORD HEAT. IN FACT, THE LOW-LEVEL THICKNESSES APPROACH NEAR
MAXIMUM VALUES FOR THIS AFTERNOON AND EARLY EVENING. THESE VALUES
RISE SOME 16-20M FROM WED, SUPPORTIVE OF A 4-6 RISE IN HIGHS
COMPARED TO WED. THAT SHOULD PUT HIGHS ACROSS CENTRAL NC LARGELY IN
THE MID 90S ACROSS THE WEST, TO UPPER 90S TO NEAR 100 ELSEWHERE. RDU
WILL LIKELY BREAK ITS RECORD HIGH. GIVEN THE STRONG SOUTHWEST FLOW
OF 25-35 MPH WIND GUSTS, WE WILL SEE SOME DRIER AIR MIX DOWN,
ALLOWING TO DEWPOINTS TO PERHAPS MIX OUT INTO THE MID TO UPPER 60S.
HOWEVER, WE WILL ADDITIONALLY SEE MOISTURE STEADILY INCREASE AHEAD
OF THE TROPICAL REMNANTS. EVEN WITH THE LOWERED AFTERNOON DEWPOINTS,
HEAT INDICES FOR AREAS ALONG/EAST OF US-1 RANGE FROM 104 TO 108,
WITH THE HEATRISK CATEGORY IN A 3 OUT OF 4. THIS KIND OF HEAT WILL
AFFECT ANYONE WITHOUT COOLING/HYDRATION.
KEY MESSAGE 2... A CONDITIONAL THREAT FOR STRONG TO SEVERE STORMS
CAPABLE OF PRODUCING DAMAGING STRAIGHT-LINE WIND GUSTS REMAINS THIS
AFTERNOON AND EVENING, WITH GREATEST CHANCES FOR SHOWERS/STORMS LATE
TONIGHT INTO FRIDAY.
THE PATTERN TODAY THROUGH TOMORROW FEATURES A FEW SYSTEMS WORTH
NOTING. FIRST, A COLD FRONT ACROSS THE MIDWEST INTO THE OH VALLEY
WILL GRADUALLY SLIDE SOUTH BUT REMAIN NORTH OF THE REGION THROUGH
MOST OF FRI. A PRE-FRONTAL TROUGH WILL EXIST THIS AFTERNOON,
STRETCHING JUST EAST OF THE APPALACHIANS OF VA/NC. THIRD, WE
CONTINUE TO WATCH THE TROPICAL REMNANTS, WHICH WILL BRING OVERALL
DEEPENING MOISTURE TODAY THROUGH FRI.
SPC HAS MAINTAINED A MARGINAL RISK OF SEVERE STORMS TODAY AND
TONIGHT, WITH THE MAIN THREAT REMAINING DAMAGING STRAIGHT-LINE WIND
GUSTS. THE OVERALL INGREDIENTS INCLUDE HIGH DCAPE UPWARDS OF 1000
J/KG, DRIVEN IN PART BY THE INVERTED-V SOUNDINGS AND DRY AIR AT
LOWER LEVELS FROM DEEP MIXING. ADDITIONALLY, MLCAPE APPROACHES SOME
1500 J/KG, ALONG WITH MID-LEVEL FLOW AROUND 30 KTS, SUPPORTIVE OF
THIS THREAT.
THE CAVEAT IS THAT OVERALL STORM COVERAGE AT LEAST DURING THE DAY
MAY BE LIMITED. THE 00Z HREF MEMBERS ARE NOT IN AGREEMENT ON OVERALL
COVERAGE. SOME MEMBERS SHOW MORE ISOLATED ACTIVITY, FOCUSED ALONG
SUBTLE BOUNDARIES OR THE PRE-FRONTAL TROUGH. OTHER HREF MEMBERS,
NAMELY THE NSSL SHOW CONVECTION BLOSSOMING OVER SC AND REACHING
CENTRAL NC IN THE LATE AFTERNOON TO EARLY EVENING, PERHAPS ENHANCED
ALONG A SEA-BREEZE. NEEDLESS TO SAY, THERE IS QUITE A BIT OF SPREAD.
NEVERTHELESS, THAT SEVERE RISK IS WARRANTED IF STORMS CAN GET GOING.
A BETTER CHANCE OF SHOWERS AND EMBEDDED STORMS LOOKS FAVORED LATE
THU NIGHT AND OVERNIGHT INTO PERHAPS LATE MORNING TO MIDDAY FRI.
THIS IS WHEN THE TROPICAL REMNANTS FROM ARTHUR ADVECT UP INTO THE
REGION. THE 00Z MODELS APPEAR TO BE IN BETTER AGREEMENT WITH THE
TRACK OF THIS LOW, WITH THE GLOBAL MODELS PLACING ITS POSITION IN
NORTH-CENTRAL SC BY EARLY FRI MORNING. HOWEVER, A FEW CAM SOLUTIONS
(NSSL/NAM-NEST) ARE FURTHER NORTH, TRACKING THE LOW NEAR CHARLOTTE
AND RIGHT INTO THE TRIANGLE DURING THE MORNING HOURS FRI. REGARDLESS
OF SOLUTION, MOISTURE ASSOCIATED WITH THE SYSTEM SHOULD FAVOR
WIDESPREAD SHOWERS. WE ARE SLIGHTLY CONCERNED THAT THERE COULD BE AN
ISOLATED TORNADO THREAT IN SOUTHERN AREAS EARLY FRI MORNING AS THE
LOW PASSES THROUGH. DURING THIS TIME, LOW-LEVEL AND DEEP-LAYER SHEAR
INCREASE, THOUGH INSTABILITY IS SOMEWHAT UNCERTAIN. GIVEN DEWPOINTS
NEAR THE LOW 70S, THIS THREAT IS POSSIBLE BUT WITH LOW CONFIDENCE AT
THE MOMENT. THE BEST CHANCE FOR THIS WOULD BE IN THE SANDHILLS TO
SOUTHERN COASTAL PLAIN.
KEY MESSAGE 3... INCREASED FIRE DANGER TODAY AS STRONG GUSTY WINDS
AND HOT TEMPERATURES OVERLAP WITH CRITICALLY DRY, DROUGHT-CURED
FUELS.
THE STOUT SW WINDS OUT AHEAD OF THE APPROACHING SURFACE FRONT (FROM
THE NNW) AND APPROACHING DISSIPATING TROPICAL SYSTEM (FROM THE WSW)
ARE EXPECTED TO PEAK AT SUSTAINED VALUES OF 15-20 MPH, WITH FREQUENT
GUSTS AS HIGH AS 25-35 MPH EXPECTED AS DEEP MIXING TAPS INTO STRONG
WINDS JUST ALOFT. WHILE RH VALUES ARE EXPECTED TO BE MOSTLY 35-40%
AND THUS ABOVE TYPICAL CRITICAL THRESHOLDS, THE ONGOING SEVERE-TO-
EXCEPTIONAL DROUGHT AND EXCEPTIONALLY DRY FUELS COMBINED WITH THESE
GUSTY WINDS WILL LEAD TO AN INCREASED RISK OF FIRE IGNITION AND
ADVERSE FIRE BEHAVIOR OVER MUCH OF NC TODAY, FROM JUST INLAND TO
JUST EAST OF THE FOOTHILLS. THIS RISK WILL BE AMPLIFIED BY ERRATIC
AND SHIFTING WINDS AND GUSTS IN AND NEAR STORMS. AFTER COORDINATION
WITH THE NC FOREST SERVICE AND THEIR FIELD OPERATIONS STAFF, A FIRE
DANGER STATEMENT REMAINS IN EFFECT TO ADDRESS THE INCREASED FIRE
DANGER.
AVIATION /12Z THURSDAY THROUGH MONDAY/
AS OF 618 AM THURSDAY...
AREAS OF MVFR STRATUS HAVE DEVELOPED IN THE CONTINUED MOIST
SOUTHWEST FLOW. THE MVFR STRATUS IS MORE WIDESPREAD THAN
ANTICIPATED, LIKELY TO IMPACT ALL TERMINALS FOR PORTIONS OF THE
EARLY MORNING. THESE CONDITIONS SHOULD LIFT TO VFR ~14-15Z, WITH
GUSTY SW WINDS COMMENCING IN THE 25-30 KT RANGE. THESE GUSTS SHOULD
WEAKEN TONIGHT, BUT STILL REMAIN ELEVATED IN THE 10-20 KT RANGE
UNTIL 02-03Z.
THUNDERSTORM CHANCES REMAIN UNCERTAIN FOR THE AFTERNOON AND EARLY
EVENING HOURS. THE LATEST RUNS OF THE HRRR AND NAM-NEST SHOW BETTER
AGREEMENT ON CONVECTIVE CHANCES. BOTH MODELS INDICATE LIMITED
OVERALL COVERAGE DURING THE DAY AND EVENING, WITH THE BEST CHANCE AT
GSO/INT IN ASSOCIATION WITH A PRE-FRONTAL TROUGH. WE UPGRADED THE
PROB30 TO TEMPO AT THESE TERMINALS. HOWEVER, GIVEN THE UNCERTAINTY ON
COVERAGE FURTHER EAST, WE OPTED TO LEAVE OUT ANY MENTION OF STORMS
AT THE REMAINING TERMINALS. A BETTER CHANCE OF MORE WIDESPREAD
SHOWERS, WITH EMBEDDED STORMS ALSO POSSIBLE, COMES BETWEEN 06-12Z
FRI WHEN THE REMNANTS OF ARTHUR MOVE INTO THE REGION. THIS SHOULD BE
ACCOMPANIED BY IFR/MVFR CONDITIONS.
LOOKING BEYOND 12Z FRI: AREAS OF SHOWERS WITH SOME EMBEDDED STORMS
ARE EXPECTED FRI MORNING AND EARLY AFTERNOON. VFR CONDITIONS SHOULD
THEN RETURN LATE FRI THROUGH AT LEAST SUN, WITH ANOTHER CHANCE OF
SUB-VFR STRATUS SUN NIGHT INTO EARLY MON WITH OUR NEXT FRONTAL
SYSTEM.
CLIMATE
RECORD HIGH TEMPERATURES:
JUNE 18: KGSO: 100/1944 KRDU: 98/2015 KFAY: 102/1944
RECORD HIGH MINIMUM TEMPERATURES:
JUNE 18: KGSO: 73/2018 KRDU: 77/2025 KFAY: 76/2017
JUNE 19: KGSO: 77/1970 KRDU: 73/2025 KFAY: 77/2017
RAH WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
FOR NCZ008>011-024>028-040>043-075>078-085-086-088-089.
DISCUSSION...KREN/HARTFIELD
AVIATION...KREN
CLIMATE...RAH
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