Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS62 KILM 230230
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1030 PM EDT FRI AUG 22 2014

.SYNOPSIS...
A COLD FRONT WILL SLIP SOUTHWARD INTO THE AREA SATURDAY. THIS FRONT
WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS SATURDAY..
.BEFORE MUCH COOLER AND DRIER AIR FILTERS INTO THE REGION FOR
SUNDAY. HIGH PRESSURE EXPANDING SOUTH FROM NEW ENGLAND WILL BRING
COOL AND DRY WEATHER FOR THE FIRST HALF OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1030 PM FRIDAY...ALTHOUGH IT AFFECTED ONLY A SMALL PORTION OF
OUR FORECAST AREA THIS EVENING`S STORMS WERE IMPRESSIVE. WIND GUSTS
WERE MEASURED AS HIGH AS 47 MPH AT WRIGHTSVILLE BEACH...42 MPH AT
THE WILMINGTON STATE PORT...AND 39 MPH AT THE WILMINGTON AIRPORT.
DUAL-POL RADAR PRECIP ESTIMATIONS APPEAR TO BE RUNNING WITHIN WITHIN
5-10% OF ACTUAL GAUGE TOTALS WITH INDICATE 0.5 TO 2.5 INCH TOTALS
ARE WIDESPREAD ACROSS NEW HANOVER AND EASTERN BRUNSWICK COUNTIES.

NOW THAT THIS WAVE OF STORMS IS OFFSHORE...ATTENTION TURNS TO THE
NEXT UPPER DISTURBANCE CURRENTLY MOVING SOUTHEAST ACROSS THE NC/VA
BORDER. THE LAST FEW HRRR RUNS STILL TRY TO CRANK OUT SCATTERED
CONVECTIVE SHOWERS AND T-STORMS WITH THIS FEATURE AS IT DIPS INTO
THE COASTAL PLAIN VERY LATE TONIGHT. PREVIOUS DISCUSSION FROM 730 PM
FOLLOWS...

A HOT AIRMASS COVERS THE CAROLINAS THIS EVENING. 850 MB TEMPS AROUND
+20C USUALLY EQUATES TO UPPER 90S INLAND FROM THE COAST AND TODAY`S
HOT TEMPERATURES OF 97 IN FLORENCE AND LUMBERTON WERE EXPECTED. AN
UPPER LEVEL RIDGE CENTERED OVER MISSISSIPPI IS PRODUCING A NORTHWEST
UPPER WIND OVER THE CAROLINAS. A SERIES OF UPPER LEVEL DISTURBANCES
EMBEDDED WITHIN IN THE 20-25 KT 700-500 MB FLOW ARE PRODUCING WAVES
OF SHOWERS AND THUNDERSTORMS. ONE SUCH WAVE IS APPROACHING
WILMINGTON FROM THE NORTH NOW AND SHOULD BE OFF THE COAST SOUTH OF
CAPE FEAR BY LATE THIS EVENING. A SECOND DISTURBANCE NOW IN
SOUTHWESTERN VIRGINIA AND EASTERN KENTUCKY WILL TAKE A MORE WESTWARD
TRACK...REACHING THE SC PEE DEE AND INTERSTATE 95 CORRIDOR LATE
TONIGHT. THIS IS ALSO WHEN A SYNOPTIC COLD FRONT WILL BEGIN TO EASE
SOUTHWARD THROUGH SOUTHEASTERN NORTH CAROLINA...REACHING
NORTHEASTERN SOUTH CAROLINA BY DAYBREAK SATURDAY.

THUNDERSTORMS SHOULD CONTINUE TO BUILD SOUTHWARD INTO WILMINGTON
OVER THE NEXT FEW HOURS...AND POPS HAVE BEEN RAISED TO 70 PERCENT
FROM BURGAW SOUTH THROUGH WILMINGTON AND WRIGHTSVILLE BEACH. THE
AIRMASS IS MODERATELY UNSTABLE (CAPE AROUND 2000 J/KG) AND THERE IS
ENOUGH HUMIDITY NEAR THE LCL TO ALLOW SURFACE-BASED PARCELS TO REACH
THEIR LFC AND KEEP ON GOING. ACTIVITY WILL BE MUCH MORE SPARSE IN
COVERAGE WESTWARD ACROSS THE SOUTH CAROLINA COASTAL PLAIN WHERE
ENVIRONMENTAL RELATIVE HUMIDITY NEAR THE LCL IS ONLY 50 TO 60%.

OUTSIDE OF AREAS THAT RECEIVE THUNDERSTORMS...TEMPERATURES WILL FALL
QUITE SLOWLY THIS EVENING IN THE HOT AIRMASS. NEAR THE COAST
DEWPOINTS IN THE MID TO UPPER 70S WILL MAINTAIN HEAT INDICES IN THE
AROUND 100 THROUGH 8 PM...AND IN THE 90S UP UNTIL ALMOST MIDNIGHT.
LOWS SHOULD ONLY FALL INTO MID 70S FOR MOST ARES WITH SOME UPPER 70S
NEAR THE BEACHES.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FEATURE OF INTEREST THIS WEEKEND IS A BACK
DOOR COLD FRONT WHICH WILL DROP ACROSS THE AREA FROM NE TO SW ON
SATURDAY. THIS FRONT WILL BE DRIVEN BY AN AMPLIFYING 5H
PATTERN...WITH A STRONG RIDGE GETTING SQUEEZED NORTH ACROSS THE
MIDDLE OF THE COUNTRY BETWEEN TROUGHS ON BOTH COASTS. IT IS THIS
EASTERN TROUGH DIVING SW THROUGH THE WKND THAT PUSHES THE BACK DOOR
FRONT INTO...AND THROUGH...THE CWA SATURDAY. ALTHOUGH THE SURFACE
FRONT CROSSES SATURDAY...STRONG CAA LAGS ABOUT 18 HRS BEHIND...AND
THUS SATURDAY WILL AGAIN BE A WARM DAY LOCALLY. HOWEVER...INCREASED
CLOUDINESS...LOWERED THICKNESSES...AND SHOWERS/STORMS WILL KEEP
TEMPS MUCH COOLER THAN THE PAST FEW DAYS...WITH HIGHS RISING TO
AROUND 90 IN THE FAR NORTH...MID 90S IN THE SOUTHERN PEE DEE. WHILE
FORCING IS NOT STRONG WITH THE FRONT...AND A DIVING UPPER JET WILL
ACTUALLY PUT THE REGION BENEATH THE RFQ...AN UNFAVORABLE POSITION
FOR UPPER SUPPORT...STILL EXPECT CLIMO POP FOR SCT SHOWERS AND TSTMS
THANKS TO PWATS NEAR 2 INCHES AND STRONG SURFACE CONVERGENCE INTO AN
UNSTABLE ENVIRONMENT. ALTHOUGH COOL ADVECTION WILL BEGIN
OVERNIGHT...LOWS WILL REMAIN ABOVE NORMAL...LOW 70S AREA-WIDE.

COOL AND DRY ADVECTION BEGINS IN EARNEST SUNDAY MORNING...AND PWATS
DROP TO LESS THAN 1 INCH...LOWEST NORTH...WITH 850MB TEMPS DROPPING
5C THROUGH THE DAY. LOTS OF LATE-AUGUST SUNSHINE WILL SOMEWHAT
COUNTERACT STRONG CAA...BUT HIGHS SUNDAY WILL LIKELY BE 5-10 DEGREES
COOLER THAN SATURDAY...AND IN FACT ARE EXPECTED TO BE BELOW
NORMAL...LOW 80S FAR NORTH TO UPR 80S IN THE SOUTH. A FEW SHOWERS
ARE POSSIBLE...ESPECIALLY EARLY IN THE DAY ACROSS THE SC ZONES
CLOSER TO THE FRONT...BUT ACTIVITY WILL NOT BE WIDESPREAD OR STRONG.
MUCH COOLER MINS SUNDAY NIGHT WITH MID 60S EXPECTED FAR NORTH IN THE
DRY COLUMN...UPPER 60S NEAR THE SOUTH SANTEE RIVER AND ON THE
BEACHES.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE EXTENDED FORECAST WILL GENERALLY BE DRY
AND SEASONABLE AS A MID LEVEL RIDGE INITIALLY OVER THE MISSISSIPPI
VALLEY SHIFTS TO MORE OF A SOUTHERN POSITION BY THE END OF THE
PERIOD. AT THE SURFACE...HIGH PRESSURE WILL WEDGE DOWN THE EAST
COAST AND EXTEND DOWN INTO GEORGIA FOR MONDAY THROUGH WEDNESDAY.
BEYOND THIS...THE FEATURE BREAKS DOWN LEAVING A WEAK PATTERN AT
THE SURFACE AND ISOLATED SHOWERS AND THUNDERSTORMS MAKE AN
APPEARANCE IN THE FORECAST. THE CHANCES WILL NOT BE GOOD UNTIL
FRIDAY WHEN ANOTHER FRONT DROPS INTO THE REGION PROVIDING A BETTER
FOCUS. TEMPERATURES WILL BE SLIGHTLY BELOW CLIMATOLOGY MONDAY
THROUGH WEDNESDAY WITH THE AXIS OF SURFACE HIGH PRESSURE PROVIDING
A COOL NORTHEAST FLOW. THURSDAY AND FRIDAY SEE MODERATING VALUES
CLOSER TO OR EVEN A BIT ABOVE NORMAL.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...RADAR IMAGERY SHOWS SOME SHRA/TSRA ASSOCIATED WITH AN
UPPER DISTURBANCE MOVING ACROSS OUR NORTHERN ZONES THIS EVENING.
WILL MAINTAIN VCSH/VCTS FOR KLBT/KILM EARLY THIS EVENING AS THESE
STORMS NEAR THE AREA. IT APPEARS MOST OF THE ACTIVITY AFTER 00Z WILL
MISS OUR NORTHERN TERMINALS...THOUGH KILM COULD SEE ANOTHER ROUND OF
SHRA TONIGHT BEFORE THE CONVECTION GRADUALLY WEAKENS. EXPECT MAINLY
VFR CONDITIONS OVERNIGHT...EXCEPT FOR PERHAPS SOME MVFR VSBYS EARLY
SAT MORNING. FCST SOUNDINGS AND GUIDANCE ARE NOT PARTICULARLY KEEN
ON FOG...BUT WILL INCLUDE TEMPO MVFR FOR FOG-PRONE KCRE.

A COLD FRONT WILL DROP SOUTHWARD OVERNIGHT...NEARING OUR NORTHERN
TIER BY 12Z SAT. WINDS WILL SHIFT TO THE NORTH AND THEN NORTHEAST
BEHIND THE FRONT...REMAINING BELOW 10 KT. THE NAM HINTS AT SOME
POST-FRONTAL MVFR CIGS THRU THE MORNING HOURS...BUT NO SIGN OF IT IN
THE GFS/SREF OUTPUT. WILL KEEP CIGS VFR DURING THE DAY SAT. HAVE
ADDED VCSH AT ALL SITES AFTER 18Z AS SFC BOUNDARIES COMBINED WITH
DEEPENING MOISTURE COULD LEAD TO SCT AFTN CONVECTION.

EXTENDED OUTLOOK...EXPECT VFR TO PREVAIL SUN THROUGH WED AS HIGH
PRESSURE RIDGES OVER THE EAST COAST IN THE WAKE OF A COLD FRONT.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM FRIDAY...A WAVE OF STRONG THUNDERSTORMS NOW 15-20
MILES SOUTH OF BALD HEAD ISLAND DISRUPTED WIND DIRECTIONS ACROSS THE
ENTIRE CAPE FEAR REGION. A NORTH TO NORTHWEST WIND ACROSS THIS AREA
NOW SHOULD BACK AROUND TO THE SOUTHWEST AFTER MIDNIGHT. WIND GUSTS
WITH THESE STORMS WERE IMPRESSIVE: 47 MPH AT WRIGHTSVILLE BEACH AND
42 MPH AT THE STATE PORT NEAR DOWNTOWN WILMINGTON. A LULL IN
THUNDERSTORM ACTIVITY IS EXPECTED BEHIND OUR DEPARTING
DISTURBANCE...BUT ADDITIONAL ISOLATED SHOWERS AND T-STORMS COULD
DEVELOP LATER TONIGHT AS A SECOND UPPER LEVEL DISTURBANCE APPROACHES
FROM THE NORTH. PREVIOUS DISCUSSION FROM 730 PM FOLLOWS...

A COLD FRONT ACROSS NORTH-CENTRAL NORTH CAROLINA WILL SINK SOUTHWARD
OVERNIGHT...REACHING AS FAR SOUTH AS MYRTLE BEACH BY DAYBREAK
SATURDAY. UNTIL THEN...SOUTHWEST WINDS 10-15 KNOTS ARE EXPECTED
ALONG WITH 2 FOOT SEAS...EVENLY SPLIT BETWEEN A SOUTHEASTERLY SWELL
AND A SOUTHWEST WIND CHOP. SCATTERED THUNDERSTORMS AHEAD OF THE
FRONT WILL BE MOST NUMEROUS THIS EVENING IN THE CAPE FEAR-AREA
WATERS. ANY STORMS WILL BE CAPABLE OF PRODUCING GUSTY OUTFLOW WINDS
AND PLENTY OF LIGHTNING. ALTHOUGH COVERAGE WILL DIMINISH OVERNIGHT
THE CHANCES OF ADDITIONAL POP-UP STORMS WILL CONTINUE THROUGH
DAYBREAK...SHIFTING SOUTHWARD TO THE SOUTH CAROLINA WATERS WITH THE
FRONT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...BACK DOOR COLD FRONT WILL DROP ACROSS THE
WATERS FROM NE TO SW DURING SATURDAY...CAUSING A WIND SHIFT TO THE
N/NE BEHIND THIS BOUNDARY. WIND SHIFT WILL OCCUR FIRST ACROSS THE
FAR NORTHERN LEGS OFF THE CAPE FEAR COAST...WITH WINDS BECOMING N
THEN NE SATURDAY MORNING...WITH THE WATERS OFF GEORGETOWN COUNTY NOT
EXPERIENCING THE WIND SHIFT UNTIL SATURDAY NIGHT. THE GRADIENT
REMAINS RELAXED SATURDAY...SO WIND SPEEDS THROUGH THIS FRONTAL
PASSAGE WILL BE 5-10 KTS REGARDLESS OF DIRECTION. VERY LATE SATURDAY
NIGHT AND ESPECIALLY ON SUNDAY...A NE SURGE OCCURS AND WINDS QUICKLY
RISE TO 15-25 KTS ACROSS THE WATERS. SEAS THROUGH THE WKND WILL BE
PRIMARILY WIND DRIVEN...RISING FROM 2-3 FT SATURDAY...TO 4-6 FT ON
SUNDAY...AND A SMALL CRAFT ADVISORY MAY BE NEEDED.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...EXPECT NORTHEAST WINDS THROUGH THE PERIOD
COURTESY OF HIGH PRESSURE ALIGNED ALONG THE EASTERN SEABOARD. WIND
SPEEDS WILL BE 15-20 KNOTS MONDAY INTO MIDDAY TUESDAY RETREATING
FROM THAT POINT ON TO SINGLE DIGITS BY LATER WEDNESDAY. LOWER
CONFIDENCE IN SEAS AS THE SPECTRUM IS HIGHLY DEPENDENT ON HOW
INVEST AL96 DOES. CURRENTLY THERE IS A FEW SIX FOOTERS ACROSS THE
OUTER WATERS OF AMZ252 BUT OTHERWISE THE SEAS ARE 3-5 FEET. IF THE
SYSTEM DEVELOPS MORE THAN ANTICIPATED THE SWELL ADDED TO THE
SPECTRUM COULD INCREASE THE SIGNIFICANT SEAS.

&&

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

&&

$$

SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...BJR




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.