375
FXUS62 KILM 291025
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
625 AM EDT TUE APR 29 2025
SYNOPSIS
HIGH PRESSURE WILL SETTLE BETWEEN THE CAROLINAS AND BERMUDA
THROUGH THE REMAINDER OF THIS WEEK. SEVERAL DAYS OF ABOVE-NORMAL
WARMTH BEGIN TODAY AND CONTINUE THROUGH THE REMAINDER OF THE
WEEK. SHOWER AND THUNDERSTORM CHANCES RETURN ON FRIDAY AND
SATURDAY AHEAD OF THE NEXT COLD FRONT.
NEAR TERM /THROUGH TONIGHT/
A 500 MB RIDGE EXTENDING NORTH FROM A HIGH CENTERED OVER THE WEST
CENTRAL GULF WILL REACH THE CAROLINAS LATER TONIGHT INTO TONIGHT.
THE SURFACE HIGH ALREADY HAS DRIFTED OFF THE NC/VA COAST AND OUR
WINDS SHOULD GENERALLY BE SOUTHEASTERLY TODAY, TRANSPORTING IN
ENOUGH LOW LEVEL MOISTURE TO FEED SCATTERED CUMULUS CLOUDS MAINLY
ACROSS SOUTH CAROLINA. A STRONG SUBSIDENCE INVERSION BETWEEN 5000-
7500 FEET AGL WILL CAP OFF THESE CLOUDS, PREVENTING ANY SIGNIFICANT
VERTICAL DEVELOPMENT AND KEEPING FORECAST POPS NEAR ZERO PERCENT
TODAY AND TONIGHT.
THE OVERALL AIRMASS HAS WARMED BY A COUPLE DEGREES SINCE YESTERDAY
AND FORECAST HIGHS RANGE FROM THE MID 80S ACROSS THE PEE DEE REGION
TO THE MID 70S ON THE BEACHES. WINDS SHOULD DIMINISH TONIGHT WITH
ENOUGH RADIATIONAL COOLING EXPECTED TO DIP LOWS INTO THE UPPER 50S
WITH LOWER 60S AT THE COAST WITH MAINLY CLEAR SKIES CONTINUING.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
MID-LEVEL RIDGING AND ASSOCIATED SUBSIDENCE/DRY AIR WILL REMAIN
IN PLACE THROUGH THIS PERIOD WHILE SURFACE HIGH PRESSURE
OFFSHORE KEEPS A WARM, MOIST SOUTHERLY LOW-LEVEL FLOW GOING.
FAIR WEATHER CUMULUS AND PASSING HIGH CLOUDS CAN BE EXPECTED
UNDER THIS REGIME, WITH A POP-UP SHOWER NOT ENTIRELY OUT OF THE
QUESTION ALONG THE SEA BREEZE. VERY DRY MID-LEVEL AIR AND
CAPPING SHOULD PREVENT ANYTHING BEYOND AN ISOLATED POP-UP SHOWER.
HIGH TEMPS WILL REMAIN ABOUT 5-10F ABOVE NORMAL FOR THIS TIME OF
YEAR, WITH MID-UPPER 80S INLAND AND LOW-MID 80S NEARER TO THE
COAST. MORNING LOWS ON THURSDAY AND FRIDAY IN THE LOW-MID 60S
IN TANDEM WITH DEW POINTS IN THE LOW 60S WILL MAKE FOR A
SOMEWHAT MUGGY FEELING EARLY.
LONG TERM /FRIDAY THROUGH MONDAY/
SUMMARY: RECENT GUIDANCE TRENDS SUPPORT A SLOWER ARRIVAL TO THE COLD
FRONT OVER THE WEEKEND, WITH IT POTENTIALLY NOT PUSHING THROUGH UNTIL
SATURDAY NIGHT INSTEAD OF THE PREVIOUS EXPECTATION FOR IT TO
PUSH THROUGH EARLY ON SATURDAY. THIS WILL NEED TO BE MONITORED
CLOSELY AS THE SLOWER SCENARIO WOULD SUPPORT ANOTHER ABNORMALLY
WARM DAY ON SATURDAY FOLLOWED BY SCATTERED TO NUMEROUS SHOWERS
AND STORMS DURING THE AFTERNOON INTO THE OVERNIGHT ALONG AND
AHEAD OF THE FRONT. THE MAIN CHANGES TO THE FORECAST REFLECTING
THIS POTENTIAL INCLUDE HIGHER RAIN CHANCES (UP TO 50%) ON
SATURDAY AND DEW POINTS LINGERING IN THE MID 60S, BUT HIGH TEMPS
AND POPS MAY NEED TO RAISED FURTHER IN FUTURE UPDATES. BEHIND
THIS DELAYED COLD FRONT, COOLER AND DRIER AIR THAN ORIGINALLY
ANTICIPATED WOULD FILTER IN, KNOCKING HIGH TEMPS DOWN INTO THE
70S FOR SUNDAY AND MONDAY.
DETAILED DISCUSSION: SOME NOTABLE TRENDS IN BOTH THE
OPERATIONAL GUIDANCE AND ENSEMBLES OVER THE LAST SEVERAL RUNS
HAVE MADE FOR SOME NOTABLE CHANGES TO THE FORECAST WITH THIS
UPDATE. THE TRENDS POINT TOWARD THE ARRIVAL OF MID-LEVEL
TROUGHING BECOMING INCREASINGLY DELAYED AS A POTENT SHORTWAVE
DIVES SOUTHEASTWARD FROM THE NORTHERN PLAINS, CAUSING A SHARPER
TROUGH TO TAKE SHAPE FURTHER WEST ON FRIDAY AND FRIDAY NIGHT
WHILE MORE AMPLIFIED RIDGING BUILDS OVER THE CENTRAL US. THIS
DELAYS THE ARRIVAL OF THE SURFACE COLD FRONT UNTIL LATE SATURDAY
OR SATURDAY NIGHT AND SUBSEQUENTLY RAISES THE CHANCES FOR
SHOWERS AND THUNDERSTORMS CONSIDERABLY ON SATURDAY WHILE
SOMEWHAT LOWERING CHANCES ON FRIDAY. IN ADDITION, THE SHARPER
TROUGH WOULD LEAD TO A STRONGER PUSH OF COOL, DRY AIR IN THE
WAKE OF THE FRONT FOR SUNDAY AND MONDAY. WITH THIS ALL IN MIND,
THE GFS AND ITS ENSEMBLES ARE ON THE MORE PROGRESSIVE SIDE
(WHICH IS TYPICAL), SO THIS WILL NEED TO BE MONITORED IN FUTURE
RUNS TO SEE IF IT CONTINUES TO TREND SLOWER AND MORE AMPLIFIED
WITH THE TROUGHING AND LATER WITH THE COLD FRONT'S ARRIVAL.
WHILE WEAK TO MODERATE INSTABILITY AND LESS CAPPING SHOULD
SUPPORT POP-UP SHOWERS AND STORMS ON FRIDAY, NEBULOUS FORCING
AND WEAK SHEAR SHOULD KEEP THESE ISOLATED AND DISORGANIZED AT
THE WORST. OTHERWISE, MIXED CLOUDS AND SUN WITH CONTINUED ABOVE-
NORMAL HIGHS IN THE MID-UPPER 80S AWAY FROM THE COAST ARE
EXPECTED. ON SATURDAY, A DELAYED COLD FRONT AND SHARPER TROUGH
WOULD PRESENT MORE OF AN OPPORTUNITY FOR INSTABILITY TO DEVELOP
AND WIND SHEAR TO INCREASE, LEADING TO THE POTENTIAL FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS, SOME OF WHICH
COULD BE STRONG. AT THIS POINT, POPS ARE HELD AT HIGH CHANCE TO
BEGIN THE TREND UPWARD. IN ADDITION, WHILE HIGH TEMPS ARE PRESENTLY
FORECAST TO REACH THE LOW 80S, A DELAYED FRONT WOULD ALLOW FOR
TEMPS TO REACH THE MID-UPPER 80S INLAND FOR ONE MORE DAY. THUS,
NOTABLE CHANGES TO THE TEMP FORECAST ARE POSSIBLE IN FUTURE
UPDATES.
BEHIND THE COLD FRONT, WINDS VEER TO NORTHERLY AS HIGH PRESSURE
OVER THE MIDWEST BUILDS IN, BRINGING CONSIDERABLY COOLER
TEMPERATURES AND MUCH LOWER DEW POINTS FOR SUNDAY AND MONDAY,
WITH HIGH TEMPS AND DEW POINTS SHOWING DOWNWARD ADJUSTMENTS OF
SEVERAL DEGREES IN THIS UPDATE.
AVIATION /12Z TUESDAY THROUGH SATURDAY/
THERE IS HIGH CONFIDENCE IN VFR CONDITIONS PERSISTING OVER THE
NEXT 24 HOURS.
EXTENDED OUTLOOK...GENERALLY VFR. MVFR/IFR IS POSSIBLE
THURSDAY MORNING IN GROUND FOG.
MARINE
THROUGH TONIGHT...
1028 MB HIGH PRESSURE CENTERED OFF THE OUTER BANKS WILL DRIFT
SLOWLY EASTWARD OVER THE NEXT 24 HOURS, MAINTAINING A SLOWLY
VEERING ONSHORE WIND ACROSS THE COASTAL CAROLINAS. SYNOPTIC WIND
SPEEDS AROUND 10 KNOTS WILL BE SUPPLEMENTED BY THIS AFTERNOON'S
SEABREEZE AND SHOULD INCREASE TO NEAR 15 KNOTS NEARSHORE. SEAS
OF 2- 3 FEET THIS MORNING SHOULD BUILD MAINLY DUE TO AN
INCREASING S/SE CHOP TO A SOLID 3 FEET THIS AFTERNOON INTO
TONIGHT.
WEDNESDAY THROUGH SATURDAY...
OFFSHORE HIGH PRESSURE WILL DOMINATE THE ENTIRE PERIOD WITH
SOUTH-SOUTHWESTERLY WINDS EXPECTED. THE PRESSURE GRADIENT
TIGHTENS LATE IN THE WEEK AS A COLD FRONT DRAWS CLOSER, BUT
GUSTS ARE STILL EXPECTED STAY JUST BELOW SCA CRITERIA. THESE
GUSTS COULD CHANGE DEPENDING ON THE TIMING AND STRENGTH OF THE
WEEKEND COLD FRONT. NEARSHORE POP-UP SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE ON FRIDAY WHILE SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS ARE POSSIBLE ON SATURDAY, ESPECIALLY IF
CURRENT TRENDS TOWARDS A LATER AND STRONGER COLD FRONT
CONTINUE.
SEAS AROUND 2-3 FT THROUGH FRIDAY MORNING DUE TO A COMBINATION
OF ESERLY 8 SEC SWELLS AND SOUTHERLY WIND WAVES RISE TO 3-4 FT
FOR FRIDAY THROUGH SATURDAY AS WIND WAVES COME TO DOMINATE THE
WAVE SPECTRUM AHEAD OF A COLD FRONT.
TIDES/COASTAL FLOODING
THIS MONTH'S NEW MOON WAS TWO DAYS AGO BUT TIDAL RANGES REMAIN
LARGE. LATEST PROJECTION OF OBSERVED ANOMALIES ONTO THE
ASTRONOMICAL TIDE IMPLIES WE'LL AGAIN EXCEED MINOR COASTAL FLOOD
THRESHOLDS AT MYRTLE BEACH AND AT DOWNTOWN WILMINGTON DURING
TONIGHT'S HIGH TIDE BY ABOUT 0.2 FEET AT BOTH LOCATIONS.
WRIGHTSVILLE BEACH MAY FALL SHOW OF CRITERIA THERE BY ABOUT 0.2
TO 0.3 FEET. GIVEN THE LIMITED IMPACTS I'LL HOLD OFF ISSUING AN
ADVISORY ON THIS SHIFT AND LET THE DAY CREW LOOK OVER ANOMALIES
AGAIN.
ILM WATCHES/WARNINGS/ADVISORIES
NC...NONE.
SC...NONE.
MARINE...NONE.
SYNOPSIS...ILM
NEAR TERM...TRA
SHORT TERM...ABW
LONG TERM...ABW
AVIATION...TRA
MARINE...TRA/ABW
TIDES/COASTAL FLOODING...ABW
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page