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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 250642
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
242 AM EDT SAT MAY 25 2013

.SYNOPSIS...
DRY CANADIAN AIR WILL PREVAIL ACROSS THE REGION THROUGH THE MEMORIAL
DAY WEEKEND. A WARMING TREND WILL BEGIN ON MONDAY...CONTINUING THROUGH
THE UPCOMING WEEK WHILE REMAINING DRY. DAYTIME TEMPERATURES MAY RISE
SLIGHTLY ABOVE NORMAL WEDNESDAY THROUGH FRIDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
AS OF 3 AM SATURDAY...SPARKLING DAY ON TAP TO KICK-OFF MEMORIAL
DAY WEEKEND UNDER A COOL START THIS MORNING...AS AN AIR MASS OF
CANADIAN ORIGIN CONTINUES TO FAN ACROSS THE REGION. DURING THE
MIDDLE AND LATE AFTERNOON RELATIVE HUMIDITIES SHOULD BOTTOM OUT
AT AROUND 25 PERCENT. NORTH WINDS THIS MORNING WILL TURN MORE
WESTERLY AS DRY SHORT-WAVE ENERGY DIVING SOUTHEAST OUT OF THE
GREAT LAKES FORCES THE CANADIAN HIGH SOUTHWARD INTO GEORGIA AND
SOUTH CAROLINA. THE ONLY CLOUDS EXPECTED TODAY...POSSIBLY SHREDS
OF ICE CRYSTALS AS UPSTREAM CONVECTIVE-DEBRIS CIRRUS IS PULLED
INTO THE CIRCULATION OF THE DEPARTING UPPER TROUGH...PRESENTLY
SCOOTING AWAY FROM THE MID-ATLANTIC COAST.

MAXIMUM TEMPERATURES WILL CLIMB AROUND 25 DEGREES ABOVE MINIMUM
TEMPERATURE READINGS THIS MORNING...BRINGING MIDDLE AND UPPER 70S
FOR JUST ABOUT ALL LOCATIONS AROUND 21Z/5PM. THE LARGE DIURNAL
RANGE TODAY SHOULD FOLLOW-SUIT TONIGHT...AS CLEAR SKIES AND LIGHT
WINDS PREVAIL UNDER A CRISP AND DRY CANADIAN AIR-MASS. MINIMUM
TEMPERATURES HOWEVER INTO DAYBREAK SUNDAY MAY BE REALIZED EARLY
BEFORE DAYBREAK...AS THE MAJORITY OF DATA SUGGEST H7-H5 MOISTURE
WILL PRODUCE AN INCREASE IN HIGH CLOUDS AFTER 9Z/4AM...WHICH MAY
LEVEL OUT OR BUMP UP TEMPERATURE READINGS.

A LOOK AT MINIMUM TEMPERATURES THIS MORNING COMPARED TO RECORD
LOWS FOR MAY 25TH WILL BE COVERED IN THE DAYBREAK AFD UPDATE.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM FRIDAY...SURFACE HIGH PRESSURE RIDGING DOWN FROM THE
NORTH AND BROAD CYCLONIC FLOW WITHIN A LONGWAVE UPPER TROUGH CREATES
COOL AND DRY CONDITIONS FOR THE WKND. WHILE THE WKND WILL BE
PLEASANT WITH MOSTLY SUNNY SKY CONDITIONS OTHER THAN SOME INCREASED
MID LEVEL CLOUD COVER BENEATH A WEAK SHORTWAVE LATE SAT
NIGHT...TEMPS WILL STRUGGLE TO 4-8 DEGREES BELOW CLIMO FOR LATE MAY.
STRONGER CAA SATURDAY WILL KEEP MAX TEMPS ONLY IN THE MID 70S EVEN
WITH FULL SUNSHINE. A WEAK SURFACE TROUGH ASSOCIATED WITH THE
PASSING VORT WILL TURN WINDS BRIEFLY TO THE NORTH SAT NIGHT...BUT A
MORE WESTERLY COMPONENT WILL DEVELOP SUNDAY WHICH EASES THE CAA AND
HELPS TEMPS RISE TO NEAR 80. LIGHT WINDS IN THE COOL/DRY AIR MASS
WILL PERMIT DECENT RADIATIONAL COOLING SAT NIGHT...WITH MINS FALLING
TO 10+ DEGREES BELOW NORMAL...UPPER 40S IN THE COOLER SPOTS TO
AROUND 50 EVERYWHERE ELSE. HIGH PRESSURE DRIFTING OFFSHORE LATE IN
THE PERIOD CREATES SOME WARMER SOUTHERLY WINDS SUNDAY NIGHT...AND
MINS FALL ONLY INTO THE LOW/MID 50S BY MONDAY MORNING.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...MOST OF THE COUNTRY WILL REMAIN FAIRLY
ACTIVE THROUGH THE PERIOD WITH THE NOTABLE EXCEPTION OF THE
SOUTHEAST...WHERE MID LEVEL RIDGING WILL DOMINATE ESPECIALLY LATE
IN THE EXTENDED FORECAST.

WPC FAVORS THE ECMWF WHICH SHOWS AN ACTIVE MID LEVEL PATTERN ACROSS
THE SOUTHWEST WITH A MEANDERING CLOSED LOW AND BAROCLINIC ZONE
EXTENDING WEST TO EAST WELL TO OUR NORTH. THE ONLY POPS FOR OUR AREA
ARE SLIGHT CHANCE VALUES LATE MONDAY ACROSS NORTHERN AREAS AS A WARM
FRONT MOVES NORTH AND TUESDAY BEFORE MID LEVEL RIDGING BUILDS WHICH
WILL ALL BUT PUT A LID ON CONVECTION FOR WEDNESDAY THROUGH FRIDAY.
TEMPERATURE TRENDS REFLECT THE BUILDING RIDGE WITH AT OR JUST BELOW
SEASONAL NORMALS EARLY TRENDING TO ABOVE CLIMATOLOGY TUESDAY AND
WEDNESDAY WHERE THEY REMAIN THROUGH THE PERIOD.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT VFR AT ALL TERMS THROUGH THE VALID TAF PERIOD.
LIGHT NNW WINDS OVERNIGHT WILL INCREASE TO AROUND 10 KTS BY MID
MORNING. THE WINDS WILL SHIFT TO THE W/SW AFTER 18Z WITH HIGH
PRESSURE RIDGING INTO THE CAROLINAS. DRY AIR AND SUBSIDENCE WILL
INHIBIT CLOUD FORMATION DURING THE DAY. THE VERY WEAK GRADIENT OVER
OUR AREA AFTER 00Z SUNDAY SHOULD ALLOW THE WINDS TO BECOME CALM...
BUT THE LOW-LEVELS WILL BE TOO DRY FOR ANY FOG CONCERNS.

EXTENDED OUTLOOK...MORNING FOG POSSIBLE MONDAY THROUGH WEDNESDAY.
OTHERWISE VFR.

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...BUMPY SEAS IN PART TO CHOPPY NORTH WIND-
WAVES WILL SETTLE TODAY...AS WINDS BECOME NW-WNW AND EASE INTO
THE AFTERNOON. RESIDUAL SE WAVES OF 2 FT AT 8-9 SECONDS WILL
CONTINUE TO INTERACT WITH THE OFFSHORE WINDS TO KEEP SEAS A BIT
PITCHED-UP AT TIMES. THIS LONGER WAVE-PERIOD PORTION OF THE WAVE
SPECTRUM IS IN A GRADUAL DIMINISHING TREND. CANADIAN HIGH PRESSURE
WILL BE REINFORCED INTO EARLY SUNDAY...AND A NORTH WIND-SURGE MAY
BRING WINDS TO 13-17 KT INTO DAYBREAK SUNDAY. NO RESTRICTIONS TO
VISIBILITY OR TSTMS EXPECTED ON THE 0-20NM WATERS THROUGH TONIGHT.

SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...WINDS BECOME NW LESS THAN 10 KTS INTO SUNDAY
BEFORE VEERING TO THE SE AT LESS THAN 10 KTS SUNDAY NIGHT WHEN
HIGH PRESSURE MOVES OFFSHORE. COMBINATION OF LIGHT WINDS AND A
WEAK 2FT/8SEC SE SWELL WILL KEEP WAVE AMPLITUDES LOW THROUGH THE
PERIOD...1-2 FT.

LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 3 PM FRIDAY...THE MARINE COMMUNITY CAN EXPECT A SUMMERTIME
PATTERN THROUGH THE PERIOD WITH SOUTH TO OCCASIONALLY SOUTHWEST
WINDS. WIND SPEEDS WILL HOVER AROUND 10-15 KNOTS FOR MOST OF THE
PERIOD WITH THE HIGHER END TUESDAY AS THE GRADIENT INCREASES
COURTESY OF A WAVE MOVING BY WELL TO THE NORTH. SEAS ARE
REPRESENTATIVE OF A SUMMER PATTERN AS WELL WITH 2-3 FEET WITH
MOSTLY SHORTER PERIOD WIND WAVES.
-- End Changed Discussion --

&&

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

&&

$$

NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...SHK
AVIATION...BJR/MJC