National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS62 KILM 170541
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
141 AM EDT FRI MAY 17 2013

.SYNOPSIS...
WARM TEMPERATURES WILL CONTINUE INTO EARLY NEXT WEEK AS BERMUDA
HIGH PRESSURE REMAINS ANCHORED OFFSHORE. A MID LEVEL DISTURBANCE
WILL BRING A CHANCES OF SHOWERS AND THUNDERSTORMS OVER THE WEEKEND
INTO EARLY NEXT. DRIER WEATHER IS EXPECTED THROUGH THE MIDDLE OF
NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:45 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

A MILD EVENING AND OVERNIGHT PERIOD UNDERWAY AS SOUTHERLY FLOW
AROUND HIGH PRESSURE OFFSHORE PREVAILS. AIDING THE MILD REGIME ARE
MIDDLE AND HIGH CLOUDS AHEAD OF AN IMPULSE EVIDENT IN VAPOR
ANIMATIONS MOVING E OVER THE CENTRAL CAROLINAS. CONVECTION WAS
CONFINED MAINLY IN THE APPALACHIANS THIS EVENING.

PARTIAL BUT NOT FULL CLEARING IS EXPECTED OVERNIGHT AS A SERIES
OF UPSTREAM DISTURBANCES ALOFT PRODUCE VARYING DEGREES OF HIGH
CLOUDINESS. THIS COUPLED WITH SW LOW-LEVEL WIND FLOW OVERNIGHT
SHOULD ALLOW A SLOW DROPPING TEMPERATURE TREND WITH LOWS IN THE
MIDDLE AND UPPER 60S ALONG THE COAST BY DAYBREAK FRIDAY AND LOW
TO MIDDLE 60S INLAND. LATEST LAV GUIDANCE HAS MINS A FEW DEGREES
WARMER THAN FORECAST AND A FEW TWEAKS UPWARD ARE PLANNED FOR THE
OVERNIGHT UPDATE TO MIN TEMPS. NO OTHER CHANGES PLANNED.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...A BERMUDA RIDGE WILL KEEP IT WARM ACROSS THE
FORECAST AREA THIS PERIOD. A PIEDMONT TROUGH WILL REMAIN IN PLACE.
A BACKDOOR COLD FRONT WILL DRIFT SOUTH AND SHOULD BE NEAR THE
ONSLOW-PENDER COUNTY LINE FRI NIGHT. THIS FRONT IS EXPECTED TO
BECOME INCREASINGLY ILL-DEFINED AS IT STALLS OUT COMPLETELY. THE
FRONT SHOULD TEND TO LIFT BACK TO THE N AS THE FLOW BECOMES
PROGRESSIVELY SW...AND S BELOW 5 KFT ON SAT. A WEAK MID-LEVEL
SHORTWAVE WILL APPROACH THE AREA LATE SAT AND SAT NIGHT.

A SHARP SEABREEZE FRONT IS EXPECTED TO MOVE SLOWLY INLAND ON
FRI...RETARDED SOMEWHAT BY THE RATHER DEEP...BUT WEAK...WESTERLY
FLOW. THE SEABREEZE SHOULD MAKE MUCH BETTER PROGRESS INLAND ON SAT
GIVEN THE PREVAILING FLOW.

IN TERMS OF HOW THIS WILL AFFECT OUR SENSIBLE WEATHER. IT WILL
REMAIN WARM THROUGH THE PERIOD. FRI SHOULD BE WARMER THAN SAT GIVEN
THERE SHOULD BE AT LEAST A LITTLE LESS CLOUD COVER AND CONVECTION
SHOULD BE ISOLATED. EITHER WAY...BOTH DAYS WILL BE WELL UP IN THE
80S. A FEW 90 DEGREE READINGS ARE POSSIBLE FRI...ESPECIALLY ACROSS
PORTIONS OF THE PEE DEE. THE BEACHES AND NEARBY LOCATIONS WILL BE
WARMEST ON FRI...PERHAPS REACHING 80 DEGREES. NIGHTTIME TEMPS WILL
ALSO BE ABOVE NORMAL...MID AND UPPER 60S THROUGHOUT.

GIVEN SUBSIDENT FLOW WILL LINGER AND DRY AIR WILL BE TOUGH TO
DISPLACE FRI...WILL INCLUDE ONLY SLIGHT CHANCE POPS WITH A SLIGHTLY
BETTER CHANCE FRI EVE ACROSS PENDER AND BLADEN COUNTIES WHICH WILL
BE IN CLOSEST PROXIMITY TO THE BACKDOOR FRONT. A MORE SOUTHERLY FLOW
ON SAT AND THE APPROACH OF A WEAK SHORTWAVE TROUGH SHOULD ALLOW FOR
MORE IN THE WAY OF CONVECTION. CAPE VALUES BECOME SIGNIFICANT...IN
EXCESS OF 1500 TO 2000 J/KG...INDICATIVE OF GOOD INSTABILITY.
HOWEVER...MID-LEVEL LAPSE RATES ARE BELOW 7 DEG C/KM WHICH SHOULD
HINDER MORE ROBUST UPDRAFTS. STILL...WOULD EXPECT CONVECTION TO
DEVELOP ALONG THE INLAND PENETRATING SEABREEZE AND THE PIEDMONT
TROUGH. COVERAGE AND STRENGTH OF THE CONVECTION SHOULD BE ENHANCED
BY THE WEAK MID-LEVEL SUPPORT...ESPECIALLY ALONG AND W OF INTERSTATE
95. WILL CARRY UP TO LOW-END LIKELY POPS ACROSS THE WESTERN FRINGES
OF OUR FORECAST AREA SAT AFTERNOON AND EVE...WITH POPS DECREASING TO
SLIGHT CHANCE CLOSER TO THE COAST.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...SUMMERTIME PATTERN CONTINUES WITH BERMUDA
HIGH PRESSURE ANCHORED OFFSHORE PUMPING WARM AND MORE HUMID AIR INTO
THE REGION. WHILE THIS TYPICALLY SUPPORTS TEMPS ABOVE CLIMO WITH
DIURNAL CONVECTION...THE BEST CHANCES FOR TSTMS WILL BE SUN/MON.
UPPER IMPULSE ROTATING SLOWLY AROUND BUILDING 5H RIDGE WILL TRACK
NEARLY OVERHEAD SUN AND MON. THIS OCCURS IN AN ENVIRONMENT
CHARACTERIZED BY PWATS APPROACHING 1.8 INCHES...OR NEARLY 2 SD`S
ABOVE NORMAL FOR MID-MAY. THE COMBINATION OF THE UPPER
FORCING...SIGNIFICANT INSTABILITY OF 1000-2000 J/KG...SEA BREEZE
BOUNDARY AND PIEDMONT TROUGH...AND DEWPOINTS RISING INTO THE MID
60S...SUPPORTS WIDESPREAD CONVECTION BOTH SUN AND MON AFTN. ML LAPSE
RATES WILL BE ONLY MARGINAL HOWEVER...5-6 C/KM...SO WHILE CONVECTION
SHOULD BE PRETTY WIDESPREAD...SEVERE CONVECTION APPEARS UNLIKELY.

BY TUESDAY...UPPER VORT SWINGS OFFSHORE LEAVING SOME SUBSIDENCE
BEHIND IT IN CONJUNCTION WITH BUILDING 1000-500MB THICKNESSES. WHILE
COLUMN REMAINS QUITE MOIST...OVERALL CONVECTIVE COVERAGE WILL BE
DECREASED ON TUESDAY...AND EVEN MORESO WED/THU WITH DRIER AIR
WORKING INTO THE REGION AND SUBSIDENCE INCREASING DUE TO THE
BUILDING MID LEVEL RIDGE.

TEMPS DURING THE PERIOD WILL BE AROUND...TO SLIGHTLY ABOVE CLIMO
EACH DAY. EXPECT HIGHS IN THE LOW/MID 80S WITH LOWS IN THE LOW/MID
60S. A SLIGHT WARM UP MAY OCCUR DURING THE MIDDLE OF NEXT WEEK.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THIS TAF
PERIOD. MID/HIGH CLOUDS WILL LINGER INTO THE MORNING HOURS WITH
SOUTHWEST WINDS AOB 5 KTS. STRONG LOW-LEVEL WINDS AND CLOUD COVER
SHOULD INHIBIT FOG FORMATION OVERNIGHT. EXPECT SOME SCT CU DURING
THE DAY WITH SOUTHWEST WINDS AOB 10 KTS...BECOMING SOUTH ALONG THE
COAST FOLLOWING AFTN SEA BREEZE PASSAGE. MID-LEVEL CLOUD COVER WILL
LIKELY INCREASE AFTER 00Z BEGINNING AT THE INLAND TERMS.

EXTENDED OUTLOOK...CHANCE OF AFTN SHOWERS/TSTMS SATURDAY THROUGH
MONDAY...OTHERWISE VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:45 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

SW WINDS WILL DECREASE A BIT OVERNIGHT AS A LOW PRESSURE SYSTEM
PASSING OVER NEW ENGLAND LIFTS FARTHER TO THE NE. THIS WILL LEAVE
A SW RETURN FLOW AROUND 10 TO 15 KTS HEADING INTO THE MORNING.
SEAS MAINLY IN THE 2 TO 4 FT RANGE IN A MIX OF SSW WIND-CHOP AND
WEAK LONGER PERIOD SE WAVES. NO TSTMS OR FOG CONCERNS OVER THE
0-20NM WATERS THROUGH DAYBREAK FRIDAY.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...WINDS WILL REMAIN FROM THE SSW TO SW THROUGH
THE PERIOD. THE PROXIMITY OF THE BERMUDA RIDGE SHOULD KEEP WINDS 15
KT OR LESS. SEAS WILL RANGE FROM 2 TO 4 FT. THE BACKDOOR COLD FRONT
IS EXPECTED TO STALL JUST N OF THE WATERS FRI NIGHT...BEFORE MOVING
BACK TO THE N.

LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 300 PM THURSDAY...RETURN FLOW AROUND OFFSHORE BERMUDA HIGH
PRESSURE CREATES PERSISTENT S/SW WINDS OVER THE WATERS. WHILE
MINOR DIURNAL FLUCTUATIONS IN DIRECTION/SPEED ARE LIKELY DURING
THE PERIOD...WINDS WILL BE PREDOMINANTLY 10-15 KTS EACH DAY DURING
THE EXTENDED. EVEN THOUGH E/SE SWELL WILL SLOWLY GROW IN AMPLITUDE
WITH AN INCREASING PERIOD DURING THE EXTENDED...TO
2-3FT/10SEC...WAVES WILL STILL BE PRIMARILY WIND-WAVE DOMINATED.
SEAS OF 2-4 FT CAN BE EXPECTED EACH DAY...WITH A S/SW WIND WAVE
OVERLAYING THE E/SE SWELL.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...JDW
NEAR TERM...REK/RGZ
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/RJD/JDW/RGZ