-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 201931
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
331 PM EDT MON MAY 20 2013

.SYNOPSIS...
A DISTURBANCE ALOFT MOVING ACROSS THE AREA WILL MAINTAIN SHOWERS AND
THUNDERSTORMS THROUGH TUESDAY. DRIER AND WARMER WEATHER IS EXPECTED
MID WEEK. A COLD FRONT IS EXPECTED TO APPROACH AND CROSS THE REGION
ON FRIDAY...BRINGING DRIER AND SLIGHTLY COOLER WEATHER INTO THE NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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AS OF 300 PM MONDAY...SPC MESOANALYSIS PAGE SHOWS THE HEAVIEST
CONVECTIVE RAINFALL IN ENCOMPASSED WITHIN A DEEP POCKET OF MOISTURE
STREWN ACROSS THE CENTRAL AND EASTERN CAROLINAS...WHERE PRECIPITABLE
WATERS WERE ESTIMATED AROUND 1.8 INCHES THIS AFTERNOON. WATER VAPOR
ANIMATIONS DEPICT A COMPLEX SET OF SWIRLS EMBEDDED WITHIN A WEAK
UPPER TROUGH FROM VIRGINIA TO NORTHERN FLORIDA. DIURNAL COOLING
INTO EVENING SHOULD REMOVE SOME INTENSITY OF CONVECTION...BUT GOOD
UPPER SUPPORT AND A MOISTURE RICH ENVIRONMENT SHOULD ALLOW FOR A
FEW BIG RAIN-MAKERS TO PERSIST THROUGH EVENING. THE OVERNIGHT
PERIOD WILL LIKELY SEE RE-DEVELOPMENT OVER THE WATERS AS LOW-LEVEL
BUOYANCY INCREASES. CIRCULATION AROUND BERMUDA HIGH PRESSURE WILL
HELP GUIDE OCEAN ACTIVITY ONTO THE COAST...AND THIS PROCESS MAY
LEAD TO NOTABLE RAIN AMOUNTS OF 1/2-1 INCH FOR THE COASTAL ZONES
OVERNIGHT. WITH THIS IN MIND WILL KEEP HIGH SCATTERED TO LIKELY
POP VALUES IN PLACE OVERNIGHT INTO DAYBREAK MONDAY...GRADUALLY
SHIFTING FOCUS INLAND...TO THE COAST IN THE NEAR TERM PERIOD.
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&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
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AS OF 300 PM MONDAY...FORECAST MODELS ARE CONSISTENT IN SHOWING
THE MID LEVEL PATTERN TRANSITIONING FROM WHAT SEEMS LIKE A NEVER
ENDING TROUGH/WEAKNESS TO MORE OF A SOUTHWESTERLY FLOW. THIS IN
RESPONSE TO THE MASSIVE MID LEVEL LOW FINALLY OPENING UP ACROSS
THE NORTHERN PLAINS AND GETTING KICKED OUT.

AT THE SURFACE...BERMUDA HIGH PRESSURE WILL REMAIN THE MAIN PLAYER
ALTHOUGH THIS HAS LITTLE IMPACT OR CHANGE ON PREVAILING CONDITIONS
AS THIS HAS BEEN SECONDARY THE PAST FEW DAYS. POPS REMAIN ON A
DIURNAL CYCLE ALTHOUGH LOWER THROUGH THE PERIOD AS THE MID LEVEL
CATALYST IS ALL BUT REMOVED. HAVE OPTED FOR THE WARMER MAV NUMBERS
FOR TEMPERATURES THROUGH THE PERIOD.
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&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
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AS OF 300 PM MONDAY...ONE LAST DAY OF WARM AND HUMID CONDITIONS ON
THURSDAY AS UPPER TROUGH AND SURFACE COLD FRONT BEAR DOWN ON THE
REGION FROM THE NW. SOMEWHAT SURPRISINGLY MODELS ARE GRAVITATING
TOWARDS A QUICKER SOLUTION AND THE FRONT MAY PUSH THROUGH TUESDAY
NIGHT. AHEAD OF IT SW FLOW AND HEIGHT FALLS SHOULD YIELD BETTER THAN
AVERAGE COVERAGE OF CONVECTION AND WITH A LARGELY PINNED SEABREEZE
THERE MAY BE NO PREFERRED LOCATION FOR MEASURABLE RAINFALL ESP THIS
FAR OUT IN TIME. SYSTEM WILL MOVE A LITTLE BIT SLOWLY OWING TO THE
STRENGTH OF THE DOWNSTREAM RIDGING AND RAIN CHANCES MAY LINGER INTO
FRIDAY ESPECIALLY ALONG THE COAST. MODEST COOLING AND STRONG DRYING
WILL THEN FOLLOW FOR THE WEEKEND AND SOME VERY COMFORTABLE AND
PLEASANT WEATHER APPEARS TO BE ON TAP. DAYTIME DEVIATIONS FROM CLIMO
TEMPS SHOULD BE RATHER SMALL BUT THE NIGHTS MAY TURN COOLISH DUE TO
THE DRYING. THE POST-FRONTAL HIGH MAY MOVE OFF THE COAST ON MONDAY
ALLOWING FOR AN UPTICK IN THE DEWPOINTS.
-- End Changed Discussion --

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...MORE SHOWERS/T-STORMS ARE EXPECTED THIS AFTN WITH
MVFR/TEMPO IFR CONDITIONS IN HEAVIER DOWNPOURS. HAVE INCLUDED
VCSH/VCTS AT ALL TERMS WITH TEMPO GROUPS ATTEMPTING TO CAPTURE THE
TIMING OF PCPN BASED ON RADAR TRENDS AND HRRR OUTPUT. VFR/MVFR
LIKELY WILL PREVAIL WITH SHORT PERIODS OF IFR VSBYS IN +SHRA. MOST
PCPN SHOULD BE NEARING THE COASTAL TERMS BY MID-AFTN...THOUGH MORE
SCT SHOWERS INLAND ARE POSSIBLE AS WELL. RAIN CHANCES RAPIDLY
DIMINISH AFTER 00Z TUESDAY. FOG/STRATUS COULD BE AN ISSUE OVERNIGHT
WITH TODAYS PERSISTENT RAINFALL...HIGHEST CONFIDENCE AT KLBT/KFLO.
EXPECT MOSTLY CLOUDY SKIES AGAIN ON TUESDAY WITH S-SW WINDS 6-10
KTS. HAVE INCLUDED VCSH ALONG THE COAST TMRW TO ACCOUNT FOR SLIGHT
PCPN CHANCES AS THE UPPER DISTURBANCE NEARS THE COAST.

EXTENDED OUTLOOK...SCATTERED SHOWERS/TSTMS WITH TEMPO MVFR ON
TUESDAY. CHANCE OF SHOWERS THURSDAY THROUGH EARLY FRIDAY. OTHERWISE
VFR.

&&

.MARINE...
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NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...SUB-ADVISORY BUT LESS THAN IDEAL CONDITIONS
ON THE WATERS WITH SEAS MAINLY RUNNING 3-4 FT MOST AREAS EXCEPT
UP TO 5 FT VERY OUR WATERS OF NC. SEAS THROUGH DAYBREAK TUESDAY
WILL BE COMPRISED OF 3 FOOT SSE WAVES EVERY 6-7 SECONDS AND 1-2
FOOT ESE WAVES EVERY 10-11 SECONDS. MARINERS ARE ENCOURAGED TO
OBTAIN A RADAR BRIEFING BEFORE HEADING OUT AS SEVERAL TSTMS WILL
IMPACT THE 0-20NM COASTAL WATERS TONIGHT INTO TUESDAY MORNING.
AS FAR AS WINDS...WE CAN COUNT ON PERSISTENT SOUTHERLY FLOW OF
10-15 KT AS HIGH PRESSURE REMAINS ANCHORED OVER THE OFFSHORE
WATERS.


SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...BERMUDA HIGH PRESSURE REMAINS THE MAIN FEATURE
FOR THE COASTAL WATERS WITH A SOUTHERLY FLOW EXPECTED TO CONTINUE
THROUGH THE PERIOD. SPEEDS WILL CONTINUE IN A 10-15 KNOT RANGE
WITH A SLIGHT INCREASE CLOSER TO THE COAST EACH LATE MORNING AND
AFTERNOON WITH THE SEA BREEZE. THE LATEST RUN OF SWAN REMAINS
CONSISTENT WITH 2-4 FOOT SEAS.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...COAST WILL LIE BETWEEN STRONG HIGH PRESSURE
ACROSS THE WEST-CENTRAL ATLANTIC AND APPROACHING COLD FRONT TO THE
NW. THE LATTER WILL BE DISPLACED EASTWARD OF THE MORE TYPICAL
BERMUDA HIGH POSITION WHICH WILL ACT TO EASE THE GRADIENT OTHERWISE
EXPECTED GIVEN SUCH A LARGE ANTICYCLONE. THE RESULTING SWELL ENERGY
COULD BRING SOME SCEC-WORTHY 5 FT SEAS TO PART OF THE AREA MAINLY
NORTHERN ZONES. COLD FRONT NOW APPEARS FASTER THAN PREVIOUSLY
THOUGHT AND SHOULD YIELD VEERING WINDS BY FRIDAY MORNING WITH A TURN
TO OFFSHORE. THE OFFSHORE FETCH AND SWELL DISRUPTION WILL LEAD TO
LOWER SEAS ON FRIDAY BUT THEN THE ENSUING PUSH OF DRY HIGH PRESSURE
COULD TIGHTEN THE GRADIENT AGAIN TO WHERE HEADLINES TOUGH TO RULE
OUT.
-- End Changed Discussion --


&&

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

&&

$$
SYNOPSIS...SHK
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...BJR