Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 261454
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
954 AM EST MON JAN 26 2015

.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL CROSS THE AREA TODAY AND
CONGEAL INTO A POWERFUL NEW ENGLAND NOR`EASTER. HIGH PRESSURE WILL
MOVE INTO THE CAROLINAS BY THURSDAY FOLLOWED BY ANOTHER COLD FRONT
THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE
NORTHWEST OVER THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...COLD UPPER LEVEL LOW PRESSURE CENTERED OVER
WESTERN VIRGINIA WILL MOVE OFF THE COAST THIS EVENING. UNTIL
THEN...VERY CHILLY CONDITIONS AT 500 MB (TEMPS AS COLD AS -26C
ACROSS SE NORTH CAROLINA) WILL CONTINUE...PRODUCING STEEP MID LEVEL
LAPSE RATES AT OR JUST STEEPER THAN THE MOIST ADIABATIC LAPSE RATE.
SATELLITE SHOWS CLEAR SKIES ACROSS MOST OF SOUTH CAROLINA AND
SPREADING EASTWARD INTO SE NORTH CAROLINA. AS SUNSHINE HEATS
TEMPERATURES INTO THE UPPER 50S WE EXPECT A HEALTHY CUMULUS CLOUD
DECK TO DEVELOP THIS AFTERNOON WITH EMBEDDED TOWERING CUMULUS AND
SHOWERY CB`S AS WELL. THIS BEST POTENTIAL INITIALLY SHOULD DEVELOP
IN THE NC SOUTHERN PIEDMONT...ROTATING SOUTHEASTWARD TOWARD CAPE
FEAR THIS EVENING. NOT EVERY LOCATION WILL SEE MEASURABLE RAIN.

CHANGES TO THE FORECAST THIS MORNING INCLUDE BUMPING HIGHS UP TO
NEAR 60 NEAR THE SANTEE RIVER...DELAYING THE DEVELOPMENT OF SHOWERS
INTO THE EARLY-MID AFTERNOON HOURS...DELAYING THE ONSET OF CLEARING/
DRYING CONDITIONS THIS EVENING AS MOST OF THE LATEST MODEL DATA
INDICATES SHOWERS SHOULD CONTINUE THROUGH THE EVENING NEAR CAPE FEAR.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...BLOCKBUSTER STORM CLOBBERING NEW ENGLAND ON
TUESDAY AND AS AS USUAL WHEN THIS IS THE CASE COLD AIR WILL READILY
INVADE MOST AREAS EAST OF THE APPALACHIANS. A SMALL LAYER OF LOW
LEVEL MOISTURE STARTS OUT THE DAY BUT WITH A GREAT DEPTH OF THE
COLUMN A DRY NWRLY FLOW THIS SHOULD MIX OUT FOR NEARLY FULL
SUNSHINE. EVEN SO, THE CAA WILL CAP HIGHS IN THE MID 40S, SOME 10
DEGREES BELOW CLIMO. OFT TIMES WITH SUCH A LARGE AND STRENGTHENING
STORM OVER THE NORTHEASTERN U.S. IT IS OFTEN RATHER BLUSTERY LOCALLY
BUT THIS DOES NOT APPEAR TO BE IN THE OFFERING THIS TIME AROUND. WE
SEEM TO FIND OURSELVES IN A RELATIVE MINIMUM IN THE LOW LEVEL WIND
FIELD BETWEEN THE JET ASSOC WITH THE ACTUAL STORM CENTER AND THE
MAIN AXIS OF COLD AIR ADVECTION WEST OF THE LOW LVL THERMAL TROUGH
OVER THE GULF STATES. THERE WILL BE JUST ENOUGH WINDS TUESDAY NIGHT
TO PREVENT RADIATIONAL COOLING. SO IN AN AIRMASS COLD ENOUGH TO
BRING LOWS CLOSE TO 20 WE SHOULD INSTEAD REMAIN IN THE UPPER
20S...PERHAPS LOW 30S FAR SRN ZONES. UPPER TROUGH AXIS WELL OFFSHORE
BY WEDNESDAY WHILE THE AXIS OF HIGHEST SURFACE PRESSURES BUILDS
RIGHT OVERHEAD. SO WHILE THERE MAY BE SOME MINOR RECOVERY IN THE
BOUNDARY LAYER TEMPERATURES THE SHALLOW NATURE OF THE MIXING
(2200FT?) WILL BRING CHILLY HIGHS NEARLY IDENTICAL TO THOSE OBSERVED
TUESDAY. FORECAST SOUNDINGS WEDNESDAY NIGHT MUCH MORE TYPICAL OF
RADIATIONAL COOLING WITH NEAR ISOTHERMAL LAYER POSSIBLY AS DEEP AS
9KFT. HOWEVER DUE TO THE AFOREMENTIONED RECOVERY IN TEMPERATURES
WEDNESDAY NIGHT LOWS WILL BE SIMILAR TO THOSE OF THE NIGHT BEFORE.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...SURFACE HIGH MOVES OVERHEAD EARLY THURSDAY AND
JUST OFFSHORE IN A WEAKENING STATE LATER IN THE DAY. ZONAL MID LEVEL
FLOW NORMAL QUITE DRY BUT SOME PVA INDUCED BY THE WESTERLIES
REACTING WITH SOME LOW LEVEL MOISTURE FLOW IN THE SW WINDS TO BRING
AN INCREASE IN CLOUDS. MEANWHILE AFTERNOON TEMPS REBOUND CLOSE TO
CLIMO. WILL THIS MOISTURE BE ADEQUATE TO SUPPORT SOME PRECIPITATION
AS THE NEXT UPPER WAVE AND COLD FRONT PASS THROUGH THURSDAY NIGHT
INTO FRIDAY MORNING? HARD TO SAY THIS FAR OUT BUT GIVEN THE FAIRLY
ROBUST STRENGTH OF THE TROUGH THE SLIGHT CHANCE INHERITED POPS LOOK
FINE. EITHER WAY IT WILL STAY MILD ENOUGH TO PRECLUDE ANY PTYPE
CONCERNS. THE WEEKEND WILL BASICALLY JUST FEATURE COLD AIR ADVECTION
IN NORTHWESTERLY FLOW AROUND HUDSON BAY VORTEX. THERE MAY AT SOME
TIME BE ENOUGH OF A SPOKE OF ENERGY WITHIN THIS FLOW TO YIELD ASCENT
AND EVEN OFFSHORE PRESSURE FALLS. ANY SUCH DISTURBANCE IS FAR BEYOND
BEING SAMPLED BY UPPER AIR NETWORK AND SO SOLUTIONS MAY SHOW HIGH
VARIABILITY FROM RUN TO RUN. AT THIS TIME IT SEEMS MOST PRUDENT TO
FOCUS ON THE CHILLY TEMPS AND ADDRESS ANY CLOUD COVER AND LOW RAIN
CHANCES AT A FUTURE TIME.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...LIGHT RADAR ECHOES NORTH OF KLBT ARE NOT EXPECTED TO
IMPACT ANY TAF SITE THIS MORNING. CURRENTLY VFR CONDITIONS PREVAIL
ACROSS THE AREA WITH SOUTHWEST WINDS AOB 10 KT. LOW PRESSURE WILL
CONTINUE TRACKING ACROSS THE MID-ATLANTIC THIS MORNING...AND ITS
ASSOCIATED COLD FRONT WILL MOVE ACROSS THE REGION TODAY...BRINGING
WEST WINDS 10-15 KT WITH HIGHER GUSTS BY MIDDAY. THE ENVIRONMENT
BECOMES INCREASINGLY UNSTABLE AFTER 18Z...AND TIME-HEIGHT ANALYSIS
INDICATES LOW/MID-LEVEL ASCENT COULD RESULT IN SHOWERS DURING THE
LATE AFTERNOON/EARLY EVENING HOURS...ROUGHLY 21Z-03Z. WILL MAINTAIN
VCSH FOR ALL TERMINALS DURING THIS PERIOD...ALTHOUGH THE BEST
PCPN/MVFR CHANCES LOOK TO BE AT KLBT/KILM WHICH WILL BE CLOSEST TO
THE DEEPENING LOW OFFSHORE. GUSTY NORTHWEST WINDS UP TO 20 KT WILL
PERSIST TONIGHT AS THE LOW CONTINUES STRENGTHENING OFF THE COAST.
WRAP AROUND MOISTURE COULD ALLOW FOR MVFR CIGS TO LINGER OVERNIGHT
WITH HIGHEST CONFIDENCE AT KLBT/KILM.

EXTENDED OUTLOOK...VFR WILL PREVAIL TUESDAY THROUGH FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...BASED ON BUOY WAVE OBSERVATIONS OF 5.5 FEET
FROM THE WILMINGTON "HARBOR" BUOY LOCATED ABOUT 5 MILES SOUTH OF THE
MOUTH OF THE CAPE FEAR RIVER...I HAVE STARTED THE SMALL CRAFT
ADVISORY EARLY (NOW) FOR ALL ZONES AS IT IS LIKELY 6 FOOT SEAS ARE
BEING EXPERIENCED ACROSS AREAS WITH A LONG FETCH TO WESTERLY WINDS.
LOW PRESSURE CENTERED OVER NORTHWESTERN NORTH CAROLINA WILL SHIFT
ITS ENERGY OFF THE VIRGINIA COAST THIS AFTERNOON...AND THIS NEW LOW
WILL BECOME THE DOMINANT FEATURE FOR EAST COAST WEATHER OVER THE
NEXT 24 HOURS.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM MONDAY...MODERATE OFFSHORE FLOW ON TUESDAY AS LOW
PRESSURE BOMB OFF THE NEW ENGLAND COAST BRINGS CYCLONIC FLOW ACROSS
THE ENTIRE EAST COAST. DUE TO THE DISTANCE OF THIS STORM AND THE
FACT THAT ITS BACKSWELL DOES NOT SIGNIFICANTLY REFRACT AROUND CAPE
HATTERAS TOWARDS OUR REGION IT SEEMS THAT WE MAY NOT SEE ANY
ADVISORIES SAVE FOR PERHAPS THE FIRST FEW HOURS OF THE PERIOD.
THEREAFTER DECREASING WINDS AND SEAS EXPECTED AS THE GRADIENT EASES.
NOT TOO FAR OFFSHORE HOWEVER THERE WILL STILL BE A BROAD AGITATED
WIND FIELD AND  MARINERS VENTURING OUT PAST OUR 20NM ZONES ARE URGED
TO CHECK WITH THE OFFSHORE WATERS FORECAST FROM OPC. A FURTHER
ABATING OF THE WIND FIELD IS SLATED FOR WEDNESDAY AND THE WIND
DIRECTION WILL ALSO BE VEERING AS HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST...TAKING UP RESIDENCE ALONG THE COASTLINE BY
AFTERNOON/EVENING.

LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 300 AM MONDAY...AN INITIALLY LIGHT SOUTH TO SOUTHWESTERLY
RETURN FLOW WILL BECOME ESTABLISHED ACROSS THE SOUTHEAST AS A
WEAKENING HIGH PRESSURE CELL MOVES OFF THE COAST. BY EVENING THIS
WIND FIELD WILL INCREASE A BIT IN RESPONSE TO AN APPROACHING COLD
FRONT FROM THE NORTHWEST. THE APPROACH AND PASSAGE OF THIS BOUNDARY
WILL BRING AN EXTENDED PERIOD OF VEERING DIRECTION WHICH PAIRED WITH
THE HIGHER WIND SPEEDS COULD LEAD TO SOME MARGINAL 6 FT SEAS OVER
MAINLY NORTHERN ZONES. NW WINDS BEHIND THE FRONT ON FRIDAY WITH WIND
AND SEAS BOTH SHOWING A DOWNWARD/IMPROVING TREND.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL TO 7 AM EST TUESDAY FOR
         AMZ250-252-254-256.

&&

$$

SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...BJR




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