049
FXUS62 KILM 150142
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
942 PM EDT FRI AUG 14 2020
SYNOPSIS
OCCASIONAL SHOWER AND THUNDERSTORM ACTIVITY WILL PREVAIL
THROUGH THE WEEKEND, AS SEVERAL BOUNDARIES INTERACT ALONG WITH A
HUMID AND UNSTABLE ATMOSPHERE IN PLACE. SLIGHTLY DRIER AIR IS
EXPECTED TO INFILTRATE THE FORECAST AREA LATE SUN THRU EARLY
NEXT WEEK WITH THE DIRECT RESULT OF A BRIEF PERIOD OF LESS
THUNDERSTORM COVERAGE AND ACTIVITY. NEWLY FORMED TROPICAL STORM
KYLE OFFSHORE FROM THE DELMARVA COAST, WILL PUSH FURTHER EAST
AND FURTHER AWAY FROM THE U.S. EAST COAST DURING THE WEEKEND.
UPDATE
CONVECTIVE ACTIVITY THIS EVENING HAS REACHED THE HIEST COVERAGE
FOR THE DAY, BUT STILL REMAINS SCATTERED IN NATURE. ACTIVITY
WILL CONTINUE THRU THE NIGHT WITH CONVECTION BECOMING MORE
WIDESPREAD NEAR THE IMMEDIATE COAST AND THE ADJACENT ATL WATERS
OVERNIGHT INTO THE DAYTIME MORNING HRS. LATEST MODELS INDICATE
THE APPROACH OF THE MID-LEVEL S/W TROF FROM THE WEST AND A SFC
BOUNDARY EXTENDING ACROSS THE FA WITH SFC LOW PRESSURE
DEVELOPING ON IT. OVERALL, TSTORM ACTIVITY LATE TONIGHT THRU SAT
NIGHT LOOKS QUITE EXTENSIVE IN COVERAGE. HAVE RE-HASHED POPS FOR
THE REMAINDER OF THIS EVENING THRU THE OVERNIGHT AND MESHED THEM
NICELY INTO THE PREVIOUS DAYLIGHT POP FCST. HAVE INCREASED
OVERNIGHT LOWS BY A DEGREE OR 2, ESPECIALLY NEAR THE
COAST. PATCHY FOG REMAINS A GOOD POSSIBILITY ALONG WITH LOW
STRATUS CLOUD DECK AT TIMES. COULD BE ENOUGH MID AND UPPER LEVEL
CLOUDS TO PREVENT ANY WIDESPREAD FOG OR LOW STRATUS.
NEAR TERM /THROUGH SATURDAY NIGHT/
LOW PRESSURE LIFTING OFF TO THE NORTHEAST LEFT A WESTERLY FLOW
AND LINGERING TROUGH JUST NORTH OF FORECAST AREA. THE WESTERLY
FLOW AND A BIT OF SUBSIDENCE ON BACK END OF SHORTWAVE, PLUS
FAIRLY WIDESPREAD CLOUD COVER FROM FOG THIS MORNING GIVING A
LATE DAY START TO ANY CONVECTION. SHWRS AND TSTMS LOCATED ALONG
THE TROUGH RUNNING FROM WEST TO EAST JUST NORTH OF AREA, SHOULD
BEGIN TO SPREAD SOUTHWARD ALONG OUTFLOW FROM STORMS INTO THIS
EVENING AND WILL CONTINUE TO SEE CONVECTION ALIGNED WITH SEA
BREEZE CLOSER TO THE CAPE FEAR COAST. OVERALL, EXPECT ISO TO SCT
COVERAGE ACROSS MOST OF THE AREA IN CONTINUED WARM AND MOIST
AIR MASS.
WINDS WILL COME BACK AROUND TO THE SW THROUGH TONIGHT AND SHOULD
SEE SOME FOG AGAIN TONIGHT. WINDS WILL START PICKING UP THROUGH
SAT INTO SAT NIGHT AS MID TO UPPER TROUGH PUSHES EASTWARD AND
FRONT REACHES INTO THE CAROLINAS. PCP WATER VALUES REMAIN ABOVE
2 INCHES COMBINING WITH INCREASING UPPER LEVEL SUPPORT AND
INCREASING WINDS TO PRODUCE ENHANCED CONVECTIVE ACTIVITY ON SAT.
TEMPS WILL BE AFFECTED BY CLOUDS AND CONVECTION BUT OVERALL
EXPECT OVERNIGHT LOWS IN THE MID 70S AND HIGHS ON SAT UP IN THE
MID 80S TO NEAR 90.
SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/
MODELS CONTINUE TO INDICATE THAT STORMS WILL FIRE FIRST OVER INLAND
ZONES ALONG A FRONTAL BOUNDARY. THIS BOUNDARY AND THE STORMS ALONG
IT WILL THEN PUSH TO THE COAST DURING THE EVENING HOURS. THE ADDED
CONVERGENCE ASSOCIATED WITH THE FRONT SHOULD ALLOW STORMS TO LAST A
BIT LONGER THAN THEY OTHERWISE WOULD IN THE ABSENCE OF THE FRONT.
DAYTIME HIGHS WILL BE RIGHT AT CLIMATOLOGICAL NORMS WHILST NIGHTTIME
LOWS WILL BE ELEVATED BY LINGERING CONVECTIVE DEBRIS CLOUDS.
LONG TERM /MONDAY THROUGH FRIDAY/
CONVECTIVE SIGNALS LARGELY ABSENT IN MODEL GUIDANCE ON MONDAY. GIVEN
THAT WE ARE BETWEEN THE EXITING TROUGH FROM THE SHORT TERM AND THE
NEXT ONE APPROACHING THIS APPEARS TO LARGELY HAVE MERIT. A FEW
MESOSCALE PROCESSES SHOULD STILL MANAGE A STORM OR TWO SO THE 30-ISH
POPS FROM THE PREVIOUS FORECAST APPEAR FINE. THE NEXT TROUGH THEN
DROPS IN BY WEDNESDAY ONCE AGAIN ELEVATING THUNDERSTORM COVERAGE
ABOVE THE NORMAL FOR AUGUST. NOT SURE THAT RAMPING UP TO LIKELY IS
WARRANTED AS A LOT OF GUIDANCE SUGGESTS SINCE ALL OF THE PVA SEEMS
TO STAY TO OUR NORTH SO WE'VE TRIMMED 10-15% MOST AFTERNOONS.
THURSDAY INTO FRIDAY THIS MAY ALSO HOLD TRUE AS THE MAIN TROUGH
PULLS AWAY AND A PIECE OF IT DIGS DOWN ACROSS TX AND THE LOWER MS
VALLEY.
AVIATION /02Z SATURDAY THROUGH WEDNESDAY/
MAINLY VFR THRU THE EVENING DUE TO PCPN COVERAGE NOT AS
WIDESPREAD AS 1ST INDICATED. VCTS AND VCSH WILL BE INSTITUTED
ACROSS TERMINALS BASED ON CLOSE PROXIMITY OF CURRENT AND PROGGED
CONVECTION FOR THE REMAINDER OF THE EVENING. COULD SEE ANOTHER
ROUND OF MVFR FOG AND IFR DUE TO LOW STRATUS DURING THE PRE-DAWN
SAT HRS, MAINLY ACROSS THE INLAND TERMINALS. DURING THESE SAME
HRS AND EXTENDING THRU 15Z, THE COASTAL TERMINALS WILL SEE
CONVECTION IN CLOSE PROXIMITY ACROSS THE ADJACENT ATL WATERS.
COULD SEE ISOLATED CELLS AFFECT THE IMMEDIATE COAST BUT TOO LOW
CONFIDENCE TO ISSUE TEMPO GROUPS. NORTHEAST SC AND SOUTHEAST NC,
SHOULD SEE CONVECTION FIRE UP BY EARLY SAT AFTN AND CONTINUE
THRU SUNSET. HAVE INDICATED PREVAILING AFTN/EVENING VCTS WITH
PROB30 GROUPS HIGHLIGHTING THE TIMING FOR ATLEAST MVFR TSTORMS.
WINDS GENERALLY BECOMING SSW-SW 5 KT OR LESS OVERNIGHT AND
CONTINUING THRUOUT DAYLIGHT SAT. THE SEA BREEZE WILL AFFECT THE
COASTAL TERMINALS WITH WINDS BECOMING S-SSW AT 10 TO 15 KT.
EXTENDED OUTLOOK...SCATTERED TO NUMEROUS SHOWERS AND TSTORMS
EXPECTED THIS WEEKEND SEVERAL BOUNDARIES INTERACT. DRIER AIR MAY
WORK ITS WAY BRIEFLY ACROSS THE AREA LATE SUN INTO EARLY NEXT
WEEK WITH LESS THUNDERSTORM ACTIVITY AND COVERAGE POSSIBLE.
MARINE
WINDS HAVE BACKED FROM WESTERLY TO SW WINDS AND WILL INCREASE
THROUGH SATURDAY AS GRADIENT TIGHTENS WITH APPROACH OF
FRONT/TROUGH. INCREASING SOUTHERLY PUSH WILL DRIVE SEAS UP TO 3
TO 4 FT LATE SAT INTO SAT NIGHT. WINDS IN THE AFTERNOON NEAR
SHORE SHOULD BACK TO S WITH GUSTS UP NEAR 20 KT AT TIMES ON SAT.
A LONGER PERIOD SE SWELL 1-2 FEET EVERY 8-9 SECONDS WILL MIX
WITH SHORTER PERIOD SOUTHERLY WIND WAVES.
SOUTHWESTERLY WINDS ON SUNDAY WILL YIELD TO N TO NE FLOW BY MONDAY
AS A FRONT PUSHES ACROSS THE WATERS. WITH NO LARGE PUSH OF HIGH
PRESSURE BEHIND THE BOUNDARY AS OFTEN SEEN IN THE COOLER SEASONS NO
BIG CHANGES IN WINDS SPEED EXPECTED. IN FACT THE PRESSURE PATTERN
WILL BE SO POORLY DEFINED COME TUESDAY THAT A DOMINANT WIND DIRECTION
MAY BE HARD TO ASCERTAIN. WEAK SWELL ENERGY FROM JOSEPHINE ARRIVES
ON TUESDAY. A MORE TYPICAL SOUTHERLY FLOW RETURNS ON WEDNESDAY. WIND
SPEEDS REMAIN VERY LIGHT WEDNESDAY BUT THE AFOREMENTIONED SWELLS
COULD ADD A FOOT TO THE DOMINANT WAVE HEIGHT.
ILM WATCHES/WARNINGS/ADVISORIES
SC...NONE.
NC...NONE.
MARINE...NONE.
SYNOPSIS...DCH
UPDATE...DCH
NEAR TERM...RGZ
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DCH
MARINE...DCH/MBB/RGZ
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