000
FXUS61 KAKQ 260004
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
804 PM EDT SAT MAY 25 2013

.SYNOPSIS...
HIGH PRESSURE FROM THE GREAT LAKES AND OHIO VALLEY WILL CONTINUE
TO BUILD INTO THE MID ATLANTIC THIS WEEKEND...RESULTING IN DRY AND
COOL CONDITIONS. A WARMING TREND WILL BEGIN MEMORIAL DAY AND LAST
THROUGH NEXT WEEK AS THE HIGH BECOMES SITUATED OFF THE EAST
COAST.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST SFC ANALYSIS SHOWS ~1003MB SFC LOW PRESSURE ORIENTED JUST
OFF THE COAST OF SOUTHERN MAINE...AS THE PARENT UPPER LEVEL LOW
SPINS OVER SOUTHERN NEW ENGLAND/EASTERN NY STATE.

SKY HAS BECOME MAINLY CLEAR EARLY THIS EVENING AS MCS ACTIVITY
OVER THE MIDWEST HAS DIMINISHED OVER THE PAST FEW HOURS. EXPECT
VEIL OF SCT-BKN HIGH CLOUD COVER TO PUSH ACROSS THE CENTRAL APPS
OVERNIGHT. EXPECT THE MAJORITY OF THESE CLOUDS TO BE SHUNTED JUST
TO OUR SOUTHWEST IN THE NW FLOW ALOFT. DIMINISHING WINDS AND
MAINLY CLEAR SKIES WILL LEAD TO AN UNSEASONABLY CHILLY NIGHT.
EXPECT EARLY MORNING LOWS TO RUN ABOUT 15 DEGREES COLDER THAN
NORMAL, MAINLY 40-45 WELL INLAND AND 45 TO 50 NEAR THE COAST.
THIS WILL BE NEAR BUT JUST ABOVE RECORD LOWS (SEE CLIMATE SECTION
BELOW).

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
MID/UPPER LEVEL PATTERN WILL BE SLOW TO EVOLVE OVER THE NEXT FEW
DAYS...WITH RIDGING DOWNSTREAM OVER THE CENTRAL CONUS AND A CUTOFF
LOW GRADUALLY PUSHING NE AND OFF THE NEW ENGLAND COAST BY SUN AFTN.
AT THE SFC...PRESSURE GRADIENT WILL RELAX QUITE A BIT BY SUN AFTN AS
THE COASTAL LOW MOVES OFF TO THE CANADIAN MARITIMES AND HIGH
PRESSURE BUILDS SE FROM THE GREAT LAKES. IN TERMS OF SENSIBLE WX ON
SUNDAY...WINDS WILL BE LIGHTER AND SKIES WILL GENLY BE SUNNY. AFTER
A VERY COOL START...TEMPERATURES WILL WARM RAPIDLY WITH HIGHS 70-75
FOR MOST OF THE REGION (COOLEST NEAR THE COAST AND WARMEST
ALONG/WEST OF I-95). NOTE...STAYED ON COOL SIDE OF GUIDANCE AS MAV
NUMBERS/MOS GUIDANCE HAVE GENLY BEEN TOO WARM PAST FEW DAYS.

STILL CHILLY SUN NIGHT UNDER MAINLY CLEAR SKIES AND LIGHT WINDS BUT
WITH AIRMASS MODIFYING...EXPECT MINS TO BE A FEW DEGREES WARMER THAN
SAT NIGHT...WENT CLOSE TO MAV NUMBERS WITH LOWS PRIMARILY FROM THE
MID TO UPPER 40S. STALLED FRONTAL BOUNDARY OVER THE GULF STATES WILL
BEGIN TO LIFT NORTHWARD LATE SUN AND MON WHILE AT THE SAME
TIME...UPR LVL RIDGE WILL FINALLY PROGRESS EWD. AS A RESULT...A MORE
SIGNIFICANT WARMING TREND WILL COMMENCE ON MON. AS THE RIDGE
PROGRESSES EWD...A WARM/MOIST AIRMASS WILL INTERACT WITH THE
BOUNDARY TO PRODUCE SHOWERS AND THUNDERSTORMS OVER THE MIDWEST INTO
THE OH VALLEY MONDAY AFTERNOON. STILL LOOKS TOO DRY/STABLE E OF THE
MTNS SO WILL KEEP FORECAST DRY W/ JUST SOME SCATTERED AFTN CUMULUS
ANTICIPATED. HIGHS RANGE FROM THE UPPER 70S/NEAR 80 ALONG AND WEST
OF I-95 TO THE LOWER 70S NEAR THE COAST. ANY CONVECTIVE ACTIVITY TO
THE WEST MAY FORM INTO A MESOSCALE CONVECTIVE SYSTEM. MCS WILL ROUND
THE RIDGE...BUT WILL LIKELY DIE OUT BEFORE REACHING THE MID ATLC.
BOUNDARY WILL CONTINUE TO LIFT NWD MON NGT...MUCH MILDER WITH LOWS
FROM THE MID 50S TO THE LOWER 60S. BOUNDARY SETS UP SOMEWHERE ACRS
THE AREA ON TUE...NAM DEPICTS A LOT MORE MOISTURE THAN THE
GFS/ECMWF...BUT BOTH SUGGEST ENOUGH MOISTURE TO INCLUDE AT LEAST A
20 TO 30% FOR FOR SHRA AND AFTN TSRA ACRS THE CWA. HIGHS MAINLY
80-85 UNDER PARTLY TO MOSTLY CLOUDY SKIES AND INCREASING SOUTHERLY
FLOW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE RIDGING OVER THE EAST AND RESULTANT ABOVE NORMAL
DAYTIME TEMPS WILL HEADLINE THE EXTENDED PERIOD.

STRONG UPPER TROUGH WILL CONTINUE TO DIG OVER THE WRN CONUS
WEDS...FURTHER AMPLIFYING THE CNTRL/ERN CONUS RIDGE AS IT PROGRESSES
EWD. RIDGE AXIS WILL LOCATE FROM THE SE STATES NWWD INTO THE NRN
PLAINS...PROGRESSING EWD OVER THE MID ATLANTIC INTO THE GREAT LAKES
REGION THURS AFTERNOON. STRONG UPPER BERMUDA HIGH (+1 STD DEV)
PROGGED TO CENTER JUST OFF THE NC COAST THURS AFTERNOON.
THEREAFTER...MEDIUM RANGE MODELS IN POOR/FAIR AGREEMENT WITH UPPER
LEVEL PATTERN. MAIN ERROR REGION LOOKS TO BE OVER CNTRL QUEBEC
ASSOCIATED WITH A SHORTWAVE TRAVERSING SE CANADA (LARGE MODEL SPREAD
IN ENSEMBLE RUNS). MODELS AGREE ON COMPRESSING THE RIDGE OVER THE NE
STATES...BUT 25/00Z ECMWF IS MORE AMPLIFIED WITH THE RIDGE AXIS. THE
SUBSEQUENT SENSIBLE WEATHER IMPACT WILL BE THE LOCATION OF THE
BOUNDARY OVER THE NE STATES. REGARDLESS OF THE DIFFERENCES...FRONT
EXPECTED TO REMAIN WELL TO THE NORTH OF THE LOCAL AREA WED-FRI.
THUS...EXPECT WARM/MOIST SUMMER-LIKE AIRMASS TO ANCHOR OVER THE
REGION. +1 STD DEV H5 AND H85 HEIGHTS (AS WELL AS +1 STD DEV H85
TEMPS) WILL TRANSLATE TO TEMPS +1 STD DEV (GENERALLY IN THE
MID/UPPER 80S) WED-SAT. DEWPOINTS WILL ALSO INCREASE INTO THE MID
60S...AS PRECIP WATERS PROGGED TO BE AROUND 1.25 TO 1.5 INCHES WED
AFTERNOON BEFORE DECREASING THURS. COMBINATION OF WARM/HUMID AND
UNSTABLE AIRMASS MAY BE ENOUGH TO INTERACT WITH DEVELOPING WEAK
LEE SIDE TROUGHING TO ALLOW FOR DIURNALLY DRIVEN SHOWERS AND
THUNDERSTORMS. HOWEVER...CONFIDENCE IS NOT HIGH ATTM SO WILL LIMIT
POPS BELOW SLIGHT CHANCE. DECREASING MOISTURE THUR-SAT WILL
INHIBIT ANY CHANCES FOR PRECIP.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
BASICALLY A WIND FORECAST WITH JUST SCATTERED HIGH CLOUDS AND GOOD
VISIBILITIES INDICATED FOR THE 00Z TAF PERIOD. WINDS DIMINISH EARLY
SATURDAY EVENING. PRESSURE GRADIENT WILL MUCH LESS SUNDAY THAN IT
WAS SATURDAY AND WINDS AT THE TOP OF THE MIXING LAYER (5K FT) WILL
GENERALLY RUN 12 KNOTS OR LESS. INCLUDED GUSTS ONLY AT SBY. THERE
COULD BE GUSTS TO BETWEEN 15 AND 20 KNOTS FOR AN HOUR OR TWO AT THE
OTHER TAF SITES.

MAINLY DRY AND VFR THROUGH MOST OF THE UPCOMING WEEK. AT THIS
TIME...THE ONLY DAY WITH PCPN CHCS IS TUESDAY.

&&

.MARINE...
SCA DROPPED OVER SOUTHERN WATERS AS NOTED BELOW. KEEPING AN EYE ON
SECONDARY SURGE LATER ON THIS EVENING AS SECONDARY SFC TROUGH
PUSHES ACROSS. CWF HAS BEEN MODIFIED SLIGHTLY FROM PRVS ISSUANCE.

LOW PRESSURE WILL CONTINUE TO LIFT UP THE NE COAST TONIGHT AS HIGH
PRESSURE CONTINUES TO BUILD OVER THE OH VALLEY. CAA (850 TEMPS 2-3
STD DEV) WILL CONTINUE TO RESULT IN STRONG NW WINDS OVER THE
WATERS THIS EVENING. HOWEVER...WITH HIGH PRESSURE BEGINNING TO
EXTEND INTO THE SE STATES...THE GRADIENT OVER THE SRN COASTAL
WATERS AND CURRITUCK SOUND HAS RELAXED...WITH OBSERVED SPEEDS 10
TO 15 KT. SEAS HAVE ALSO FALLEN BELOW 4 FT. WILL END THE SCA
HEADLINES AT 6 PM EDT FOR THE SOUTHERN COASTAL ZONES AS WELL AS
THE CURRITUCK SOUND AS A RESULT. OTHERWISE...NW WINDS 15 TO 20 KT
OVER THE BAY AND 20 TO 25 KT OVER THE NRN COASTAL WATERS. SCA
SPEEDS ARE BORDERLINE OVER THE NRN COASTAL WATERS...BUT SEAS OF 5
FT STILL EXPECTED 20 NM OUT THROUGH THE OVERNIGHT. SCA HEADLINES
WILL DROP OFF EARLY SUNDAY MORNING AS HIGH PRESSURE BUILDS OVER
THE LOCAL AREA AND THE PRESSURE GRADIENT RELAXES. A FEW SCA GUSTS
MAY CONTINUE THROUGH MID MORNING ACROSS THE NRN BAY.
THEREAFTER...AN EXTENDED PERIOD OF SUB SCA CONDS EXPECTED OVER THE
WATERS AS HIGH PRESSURE CONTINUES TO BUILD OVER THE REGION THROUGH
THE MEMORIAL DAY WEEKEND. HIGH PRESSURE WILL SLIDE OFFSHORE
TUESDAY AS A WARM FRONT LIFTS OVER THE WATERS...WITH HIGH PRESSURE
REMAINING JUST OFF THE SOUTHEAST COAST THROUGH THE REMAINDER OF
THE WEEK.

&&

.TIDES/COASTAL FLOODING...
AS WITH EARLIER THIS MORNING, NOTING SOME UNUSALLY LOW TIDAL
LEVELS ACROSS THE EASTERN VA RIVERS THIS EVENING. STRONG NW FLOW
AND FULL MOON CYCLE ARE CREATING LOCALIZED LOW WATER PROBLEMS ON
THE YORK, RAPPAHANNOCK AND UPPER JAMES RIVERS. TIDAL LEVELS APPEAR
TO BE JUST A BIT ABOVE 1 FT BELOW NORMAL MLLW, BUT ARE FORECAST TO
COME VERY CLOSE TO LOW WATER ADVISORY CRITERIA. LOW TIDE CYCLE IS
ONGOING ATTM, AND WL CONTINUE TO MONITOR OVER THE NEXT FEW HRS.

&&

.CLIMATE...
SET A RECORD LOW AT ELIZABETH CITY NC THIS MORNING AT 43 F (OLD
RECORD HAD BEEN 47). MAY COME CLOSE TO CHALLENGING A FEW RECORD
LOWS AGAIN SUNDAY...RECORD LOWS FOR MAY 26TH ARE LISTED BELOW:

.RICHMOND............42 (1925)
.NORFOLK.............47 (1967)
.SALISBURY MD........39 (1917)
.ELIZABETH CITY NC...44 (1967)

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ635>638.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ630>632-634-
     650-652.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB/MAM
SHORT TERM...LKB
LONG TERM...SAM
AVIATION...JAB
MARINE...SAM
TIDES/COASTAL FLOODING...
CLIMATE...