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FXUS62 KILM 182310
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
710 PM EDT MON MAY 18 2026
WHAT HAS CHANGED
DISCUSSIONS UPDATED. PRECIP CHANCES LOWERED DURING THE
THURSDAY-SUNDAY TIMEFRAME DUE TO THE ANTICIPATED PATTERN
SUPPORTING MAINLY ISOLATED TO SCATTERED SHOWERS AND STORMS AS
OPPOSED TO WIDESPREAD PRECIP.
KEY MESSAGES
1) INLAND PORTIONS OF THE EASTERN CAROLINAS SHOULD SEE THEIR LONGEST
HEAT WAVE OF THE YEAR SO FAR WITH 90+ DEGREE HEAT EXPECTED TO
CONTINUE THROUGH THURSDAY.
2) RAIN CHANCES SHOULD INCREASE, ESPECIALLY INLAND, BEGINNING
THURSDAY AS A FRONT TEMPORARILY STALLS IN THE CAROLINAS.
DISCUSSION
KEY MESSAGE 1...INLAND PORTIONS OF THE EASTERN CAROLINAS SHOULD SEE
THEIR LONGEST HEAT WAVE OF THE YEAR SO FAR WITH 90+ DEGREE HEAT
EXPECTED TO CONTINUE THROUGH THURSDAY.
AN UPPER HIGH WILL SHIFT INTO THE ATLANTIC AND LEAVE AN AXIS OF
HIGHER HEIGHTS FROM THE GULF INTO THE CENTRAL ATLANTIC, AND THIS IS
RESPONSIBLE FOR THE SUSTAINED PERIOD OF HOT INLAND TEMPERATURES,
WHICH SHOULD LAST THROUGH THURSDAY. SINKING AIR BELOW THE UPPER
RIDGE WILL CREATE A DEEP WARM, DRY LAYER IN THE MIDDLE TROPOSPHERE,
SUPPORTING ABNORMALLY WARM SURFACE TEMPERATURES. MODELS HAVE
MAINTAINED THEIR 850 MB TEMP FORECASTS OF +16C TO 18C (AT OR ABOVE
THE 90TH PERCENTILE CLIMATOLOGICAL VALUES FOR THIS TIME OF YEAR),
WHICH INCREASES CONFIDENCE IN OUR FORECAST OF 90+ DEGREE HEAT
CONTINUING THROUGH THURSDAY FOR LOCATIONS AWAY FROM THE DAILY
COOLING INFLUENCES OF THE SEA BREEZE.
OUR FORECAST IS FOR AN ADDITIONAL THREE DAYS (TUESDAY THROUGH
THURSDAY) OF 90+ DEGREE HEAT INLAND. SINCE FLORENCE AND LUMBERTON
HIGHS REACHED 90 DEGREES ON SUNDAY, A FIVE DAY STREAK WOULD ECLIPSE
THIS YEAR'S EARLIER STREAK OF FOUR DAYS OF 90 DEGREE TEMPS RECORDED
FROM APRIL 15-18 IN BOTH FLORENCE AND LUMBERTON. COASTAL PORTIONS OF
THE CAROLINAS SHOULD REMAIN SIGNIFICANTLY COOLER THAN INLAND DUE TO
SUSTAINED SOUTH WINDS DRAGGING AIR ACROSS NEARSHORE WATER STILL NEAR
70 DEGREES.
THE UPPER RIDGE WILL BECOME INCREASINGLY NARROW WITH TIME AS AN
UPPER LOW STRENGTHENS ACROSS THE NORTHERN BAHAMAS TUESDAY INTO
THURSDAY. THIS FEATURE LOOKS A LOT LIKE AN EARLY SEASON TUTT LOW,
BUT ANY ENHANCED CONVECTION OR OTHER SENSIBLE WEATHER IMPACTS SHOULD
REMAIN FAR TO OUR SOUTH. THE ARRIVAL OF A SURFACE COLD FRONT
THURSDAY AFTERNOON SHOULD END THIS HEAT WAVE WITH TEMPERATURES
RETURNING TOWARD NORMAL FOR FRIDAY. HOWEVER, THE FRONT IS EXPECTED
TO STALL AND LIFT BACK NORTH, WITH TROUGHING TO THE WEST AND A RIDGE
CENTERED OVER THE ATLANTIC SUPPORTING MORE OF A DAILY POP-UP
CONVECTION PATTERN OVER THE WEEKEND. THUS, HIGH TEMPS WILL DEPEND ON
THE EXTENT OF CLOUD COVER AND PRECIP THAT DEVELOPS.
KEY MESSAGE 2...RAIN CHANCES SHOULD INCREASE, ESPECIALLY INLAND,
BEGINNING THURSDAY AS A FRONT TEMPORARILY STALLS IN THE CAROLINAS.
DRY WEATHER WILL COME TO AN END AS A FRONT SHIFTS IN FROM THE NORTH
ON THURSDAY. THERE'S REASONABLE UNCERTAINTY ON PLACEMENT OF HIGHEST
POPS DAY TO DAY AS WE DEAL WITH A STALLED FRONT IN OR NEAR THE AREA
AND THE DAILY SEA BREEZE. THE FRONT SHOULD LIFT NORTH OF THE AREA
INTO THE WEEKEND BUT THE WARM, HUMID AIR MASS WILL CONTINUE TO
SUPPORT AT LEAST DAILY POP-UP SHOWER AND STORM CHANCES THROUGH THE
END OF THE PERIOD.
WITH RESPECT TO THE LOWERING OF PRECIP CHANCES LATE IN THE WEEK
AND OVER THE WEEKEND, NBM-BASED AND GEFS/ECME PRECIP
PROBABILITIES APPEAR OVERDONE GIVEN THE EXPECTED PATTERN WITH A
RIDGE OVER THE ATLANTIC AND TROUGHING WELL WEST OF THE AREA.
WHILE THE INCOMING FRONT COULD BRING ENHANCED PRECIP COVERAGE
DUE TO SURFACE CONVERGENCE ALONG THE BOUNDARY PAIRED WITH A WARM
AND HUMID TROPOSPHERE, LITTLE IN THE WAY OF UPPER SUPPORT IS
DEPICTED AMONGST THE GLOBAL MODELS, LENDING LOWER CONFIDENCE TO
A WIDESPREAD COVERAGE OF PRECIP THAN WHAT WOULD BE EXPECTED
WITH 70-80% POPS. IN ADDITION, GFS MOS AND ECME MOS OUTPUT BOTH
SUPPORT LOWER PROBABILITIES FOR PRECIP GENERALLY AT OR BELOW
50%. THUS, POPS WERE LOWERED UNTIL CONFIDENCE INCREASES IN WHEN
AND WHERE A PERIOD OF GREATER PRECIP COVERAGE CAN BE EXPECTED.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
WE HAVE HIGH CONFIDENCE IN VFR CONDITIONS CONTINUING THROUGH
THIS EVENING. LOW LEVEL MOISTURE IN THE LOWEST 1000-1500 FEET
OF THE ATMOSPHERE AND CLEAR SKIES ALOFT SHOULD SET THE STAGE FOR
THE DEVELOPMENT OF FOG AND/OR LOW CEILINGS LATE TONIGHT. THERE
IS SOME RAW MODEL AND STATISTICAL GUIDANCE SUGGESTING FOG COULD
BECOME DENSE IN SPOTS. GIVEN YESTERDAY'S OBSERVATIONS ACROSS THE
REGION AND THE BETTER SETUP TONIGHT, IFR FOG HAS BEEN ADDED
TO MOST TERMINALS WITH SOME DENSE FOG POSSIBLE NEAR THE COAST.
ONCE DAYTIME HEATING CLEARS UP SURFACE VISIBILITY, DRY AIR ALOFT
SHOULD RESULT IN FEWER LOW CLOUDS LINGERING COMPARED TO WHAT WE
SAW THIS MORNING. SIMILAR AFTERNOON FORECAST WITH SOME CUMULUS
AND SOUTHEASTERLY FLOW AT THE COAST WITH GUSTS TO 15 KNOTS.
EXTENDED FORECAST... AREAS OF LOW CLOUDS AND FOG ARE POSSIBLE
WEDNESDAY THROUGH SATURDAY MORNINGS, GENERALLY IN THE 08Z-12Z
TIMEFRAME. CONFIDENCE IS MODERATE. SHOWER AND THUNDERSTORM CHANCES
WILL INCREASE ACROSS THE ENTIRE AREA FRIDAY INTO SATURDAY AS A FRONT
STALLS ACROSS THE CAROLINAS.
MARINE
THROUGH TUESDAY...BERMUDA HIGH PRESSURE RIDGING WESTWARD ACROSS
SOUTH CAROLINA WILL MAINTAIN DRY WEATHER AND A LIGHT SOUTHERLY WIND
ACROSS THE AREA. SUPERIMPOSED ON THIS SYNOPTIC WIND WILL BE A
LANDBREEZE/SEABREEZE PATTERN THAT SHOULD LEAD TO LOCALIZED STRONGER
WIND SPEEDS (10-15 KT) NEARSHORE DURING THE AFTERNOONS AND EVENINGS.
SEAS SHOULD AVERAGE 2 FEET ACROSS THE COASTAL WATERS (2-3 FEET FOR
THE WATERS OUT TO 60 MILES) MAINLY IN AN 8-SECOND SOUTHEAST
SWELL.
TUESDAY NIGHT THROUGH SATURDAY... OFFSHORE HIGH PRESSURE WILL
MAINTAIN CONTROL THROUGH MIDWEEK UNTIL A COLD FRONT APPROACHES FROM
THE NORTH. THIS FRONT LOOKS TO STALL NEAR OR OVER THE WATERS BEFORE
LIFTING BACK NORTHWARD BY LATE FRIDAY. GENERALLY SOUTH WINDS CAN BE
EXPECTED UNTIL THE FRONT DRAWS NEAR, WITH A PERIOD OF EAST OR EVEN
NORTHEAST WINDS POSSIBLE NEAR THE COAST IF THE FRONT CAN PUSH
OFFSHORE; OTHERWISE, EXPECT SOUTHEAST WINDS AHEAD OF THE FRONT.
SPEEDS ARE EXPECTED TO STAY BETWEEN 5-15 KTS, WITH ENHANCED
NEARSHORE GUSTINESS DUE TO THE SEA BREEZE LIKELY EACH DAY. SEAS ARE
EXPECTED TO HOLD IN THE 2-3 FT RANGE IN THE 0-20NMI ZONE AND 3-4
FT IN THE 20-60NMI ZONE THROUGH THE PERIOD, MAINLY DRIVEN BY
PERSISTENT SOUTHEASTERLY SWELLS WITH A PERIOD OF 8-9 SEC.
ILM WATCHES/WARNINGS/ADVISORIES
NC...COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
TUESDAY FOR NCZ107.
SC...COASTAL FLOOD ADVISORY UNTIL 11 PM EDT THIS EVENING FOR SCZ054-
056.
MARINE...NONE.
WHAT HAS CHANGED...ILM
KEY MESSAGES...ABW
DISCUSSION...ILM
AVIATION...21
MARINE...TRA/ABW
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