000
FXUS62 KILM 181904
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
304 PM EDT THU MAR 18 2010
.SYNOPSIS...
LOW PRESSURE JUST OFF THE CAROLINA COAST WILL MOVE OUT TO SEA
TONIGHT. HIGH PRESSURE WILL BUILD OVERHEAD FROM THE GULF COAST
FRIDAY THROUGH SATURDAY...BRINGING WARM DAYTIME TEMPERATURES TO
THE AREA. LOW PRESSURE OVER ARKANSAS SUNDAY WILL MOVE THROUGH THE
CENTRAL APPALACHIANS EARLY MONDAY...DRAGGING A COLD FRONT THROUGH
THE CAROLINAS. COOL TEMPERATURES MONDAY AND TUESDAY WILL MODERATE
LATER IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...VERY LIGHT INTERMITTENT RAIN ACROSS FORECAST
AREA AS MOISTURE WRAPPING AROUND BACK END OF LOW. FINALLY CROSSED
THE MEASURABLE MARK OF PCP WITH .01 AROUND NOON AT ILM. THIS LOW
PRESSURE SYSTEM LOCATED AROUND 200 MILES SOUTHEAST OF CAPE FEAR THIS
AFTERNOON WILL MOVE SLOWLY OFF TO THE E-NE THROUGH TONIGHT. AS LOW
TRACKS FARTHER AWAY...WINDS AT THE LOW TO MID LEVELS WILL BECOME
MORE NORTHERLY AND WILL ADVECT DRIER AIR INTO AREA. THERE IS VERY
DRY AIR IN A SHALLOW LAYER CLOSE TO THE SURFACE ADVECTING IN FROM
THE NORTH THIS AFTERNOON WITH DEW POINT TEMPS IN THE 20S JUST TO THE
NORTH OF CWA. WILL KEEP LOWER DEW POINTS THIS AFTERNOON BUT WILL
RAISE THEM BACK UP A BIT FOR THIS EVENING. OVERALL EXPECT
INTERMITTENT RAIN TO CONTINUE TO WRAP AROUND INTO FORECAST AREA
THROUGH THIS EVENING WITH VERY LITTLE IN TERMS OF QPF. AS WINDS BACK
TO A MORE NORTHERLY DIRECTION THROUGH THIS EVENING THE MOISTURE WILL
BE LINED UP CLOSER TO THE COAST AND WILL NOT MAKE IT AS FAR INLAND.
HIGHEST POPS AND QPF WILL BE FOCUSED ALONG THE NC COASTAL COUNTIES.
DRIER AIR WILL MAKE ITS WAY IN AFTER MIDNIGHT AS LOW TRACKS FARTHER
AWAY FROM THE COAST. CLOUDS SHOULD START CLEARING OUT AFTER MIDNIGHT
FROM N-NW TO S-SE. TEMPS OVERNIGHT WILL BE SLOW TO DROP UNTIL CLOUDS
CLEAR OUT AND THEREFORE EXPECT MOST PLACES TO DROP INTO THE MID
40S..BUT MAY SEE A FEW SPOTS OVER NORTHWEST NC COUNTIES TO DROP TO
NEAR 40.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...VERTICALLY STACKED LOW PRESSURE MOVING AWAY
FROM THE AREA FRIDAY MORNING WILL GIVE WAY TO A VERY DRY AIRMASS
ADVECTING IN FROM THE WEST. HIGH PRESSURE FROM THE SURFACE THROUGH
THE UPPER LEVELS WILL SETTLE OVERHEAD FRIDAY NIGHT...AND WILL PUSH
OFFSHORE SATURDAY. LOW PRESSURE WILL DIVE INTO THE ARKLATEX REGION
SATURDAY NIGHT WITH SOME MID AND UPPER LEVEL MOISTURE INCREASING
LOCALLY.
WITH NO PRECIPITATION AND VERY FEW CLOUDS THROUGH THE PERIOD...
ATTENTION WAS PLACED ON TEMPS...WINDS AND DEWPOINTS. HIGHS FRIDAY
SHOULD REACH THE LOWER 70S MOST AREAS...WITH MID 70S WIDESPREAD ON
SATURDAY AWAY FROM THE OCEAN. THERE SHOULD BE ENOUGH OFFSHORE FLOW
REMAINING SATURDAY AFTERNOON TO PREVENT A SEABREEZE FROM DEVELOPING
ALONG THE NC COAST...BUT WEAKER WINDS NEAR THE INCOMING HIGH COULD
ALLOW ONE TO SNEAK IN LATE IN THE DAY ALONG THE GRAND STRAND INTO
GEORGETOWN. WITH THE HIGH OFFSHORE AND A LIGHT SYNOPTIC ONSHORE FLOW
SATURDAY...THE 15-DEGREE LAND-TO-SEA AIR TEMPERATURE CONTRAST WILL
GENERATE A MODERATE SEABREEZE WITH WINDS NEAR THE BEACHES INCREASING
TO AROUND 15 MPH DURING THE AFTERNOON.
FRIDAY NIGHT'S LOWS WILL BE SURPRISINGLY CHILLY GIVEN THE WARM DAY
PRIOR. EXCELLENT RADIATIONAL COOLING WITH CLEAR SKIES AND DRY AIR
WILL ALLOW TEMPS TO DROP AS MUCH AS 35 DEGREES BELOW DAYTIME
HIGHS...INTO THE LOWER 40S MOST AREAS. A LITTLE MORE WIND BEHIND THE
DEPARTING HIGH SATURDAY NIGHT WILL TEMPER LOWS INTO THE UPPER 40S TO
AROUND 50.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...MAIN CHALLENGE IS THE TIMING OF A COLD FRONT
SLATED FOR SUNDAY NIGHT OR PERHAPS EVEN MONDAY. LAST COUPLE GFS
RUNS AND THE 00Z ECMWF ARE MUCH MORE BULLISH WITH A CUTOFF UPPER LOW
THAT WILL SLOW DOWN THE FRONT. AS SUCH...STILL EXPECTING ABOVE
NORMAL TEMPS ON SUNDAY BUT HAVE DELAYED THE INCREASE IN POPS ENOUGH
THAT COASTAL LOCATIONS WILL BE HARD PRESSED TO SEE ANY PRECIP SUNDAY
AFTERNOON.
HIGHEST POPS NOW SUNDAY NIGHT INTO MONDAY MORNING...AND IT LOOKS
LIKE WE WILL HAVE A DECENT BUT NOT STELLAR MOISTURE FEED AS
PRECIPITABLE WATER REACHES ABOUT AN INCH AND A QUARTER. RESPECTABLE
FORCING WITH THE UPPER VORT CENTER AND LIFTED INDICES GOING NEGATIVE
WILL PROVIDE AT LEAST A BRIEF WINDOW FOR THUNDER. POPS IN THE HIGH
CHANCE CATEGORY FOR NOW. HOWEVER...SINCE IT IS MORE A MATTER OF
WHEN IT WILL RAIN THAN IF...LATER SHIFTS SHOULD BE ABLE TO NARROW
DOWN THE TIME WINDOW FOR A LIKELY POP.
AS THE FRONT PUSHES THROUGH AND THE UPPER LOW HEADS OFFSHORE...FLAT
RIDGING ALOFT WILL FOLLOW RESULTING IN DRY WEATHER AND TEMPS NEAR
NORMAL TUESDAY THROUGH THURSDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
LOW PRESSURE OFFSHORE WILL CONTINUE TO ADVECT PATCHY LIGHT
RAIN...MAINLY OVER THE NORTHERN HALF OF THE CWA. LOOK FOR THESE
CONDITIONS TO PERSISTS THROUGH THE AFTERNOON. CEILINGS WILL REMAIN
VFR FOR THE MOST PART...BUT COULD NOT RULE OUT BRIEF MVFR CEILING
WHERE THE PRECIPITATION HAS PERSISTED. WINDS WILL CONTINUE MAINLY
OUT OF THE NORTH ON THE BACKSIDE OF THE LOW. THE WINDS COULD BE
BRIEFLY STRONGER THAN FORECAST...IF THE LOW DEEPENS A BIT. LOOK FOR
VFR CONDITIONS OVERNIGHT...WITH PRECIPITATION ENDING AS THE LOW
TRACKS SLOWLY AWAY FROM THE COAST. VFR FRIDAY WITH LIGHT WINDS AND
SCATTERED SKIES.
EXTENDED OUTLOOK...VFR THROUGH SUNDAY MORNING. MODERATE CONFIDENCE
TEMPO IFR VISIBILITIES/ISOLATED THUNDERSTORMS SUNDAY EVENING THROUGH
MIDDAY MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM THURSDAY...WINDS BASICALLY N-NW 15 KTS SOUTH OF CAPE
FEAR AND N AROUND 15 KTS TO THE NORTH AS LOW PRESSURE LOCATED
SOUTHEAST OF CAPE FEAR. FAIRLY TIGHT GRADIENT FLOW SHOULD PRODUCE
NORTHERLY WINDS ON BACK END OF LOW THROUGH TONIGHT PEAKING AROUND 20
KT. SCA WILL CONTINUE THROUGH TONIGHT. ALTHOUGH SEAS SEEM
BORDERLINE FOR A SMALL CRAFT ADVISORY EXPECT SEAS SHOULD SEE 6 FT
IN PORTIONS OF OUTER WATERS TO THE NORTH OF CAPE FEAR.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 3 PM WEDNESDAY...LOW PRESSURE WILL PUSH RAPIDLY OFFSHORE
FRIDAY MORNING WITH OFFSHORE WINDS DIMINISHING IN STRENGTH
THROUGHOUT THE DAY. IT IS EVEN POSSIBLE WITH THE LIGHTER FLOW
FRIDAY AFTERNOON THAT WIND DIRECTIONS COULD VEER ONSHORE ALONG THE
GRAND STRAND WITH A WEAK SEABREEZE. HIGH PRESSURE WILL MOVE
OVERHEAD FRIDAY NIGHT WITH WINDS BECOMING LIGHT AND VARIABLE. THE
HIGH WILL PUSH OFFSHORE LATE SATURDAY MORNING WITH LIGHT SOUTHERLY
WINDS DEVELOPING. LARGE TEMPERATURE CONTRASTS BETWEEN THE
RELATIVELY COLD MARINE AIR (60 DEGREES) AND WARMER CONDITIONS
INLAND (MID 70S) WILL CREATE A MODERATE SEABREEZE SATURDAY WITH
SPEEDS INCREASING TO 10-15 KT NEARSHORE DURING THE AFTERNOON.
SEAS WILL RAPIDLY DECREASE DURING THE DAY SATURDAY BEHIND THE
DEPARTING LOW. SEAS NORTH OF CAPE FEAR COULD STILL BE IN THE 3-5 FT
RANGE EARLY...BUT WILL FALL TO 3 FT OR LESS BY EVENING. 1-2 FT SEAS
ARE EXPECTED OTHERWISE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 3 PM THURSDAY...SOUTHERLY GRADIENT WILL TIGHTEN UP ON SUNDAY
AHEAD OF THE APPROACHING COLD FRONT. NOW LOOKS LIKE A BETTER SHOT
AT REALIZING SCA CONDITIONS WITH THE SLOWER FROPA...AS THE ONSHORE
FETCH WILL BE STRONGER AND LAST LONGER INTO SUNDAY NIGHT. WIND
SPEEDS LOOK MARGINAL BUT 5-7 FT SEAS ARE A PRETTY GOOD BET FOR AT
LEAST A BRIEF PERIOD NEAR DAYBREAK MONDAY.
GRADUAL SUBSIDING TREND ON MONDAY AS WINDS COME AROUND TO
WEST-SOUTHWEST AND DIMINISH. DUE WEST TRAJECTORY WILL MAINTAIN A
LARGE ENOUGH VARIATION IN FETCH LENGTH TO WARRANT A WIDE RANGE IN
SEAS...DROPPING OFF TO 2-4 FT WITHIN 20NM ON MONDAY NIGHT...WHILE 5
FOOTERS PERSIST WELL INTO TUESDAY OUT NEAR FRYING PAN BUOY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...TRA
NEAR TERM...RGZ
SHORT TERM...TRA
LONG TERM...RAS
AVIATION...DL
