Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 200810
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
410 AM EDT MON OCT 20 2014

.SYNOPSIS...
COOL CANADIAN HIGH PRESSURE WILL SLOWLY PUSH OFFSHORE TODAY. LOW
PRESSURE MOVES INTO THE REGION TONIGHT AND TUESDAY...LOCATING OFF
THE NORTHEAST COAST FOR MUCH OF THE MID TO LATE WEEK PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TEMPS HAVE DROPPED INTO THE MID-UPPER 30S INLAND TO LOW-MID 40S NEAR
THE COAST THANKS TO EXCEPTIONAL RADIATIONAL COOLING. CIRRUS HAVING
LITTLE IMPACT ON THE FALLING TEMPS...BUT DEWPOINTS IN THE MID-UPPER
30S HAVE RESULTED IN A SLOW DOWNWARD TREND THE LAST SEVERAL HOURS.
EXPECT TEMPS TO DROP ANOTHER DEG OR TWO THRU SUNRISE...WITH SOME
INLAND LOCALES WAKING UP TO FROST.

SFC HIGH PRESSURE PUSHES OFFSHORE TODAY...WITH SLY RETURN FLOW/WAA
COMMENCING. ALOFT...SHORTWAVE ENERGY DIGS OVER THE GREAT LAKES
REGION INTO THE OH VALLEY...DOWNSTREAM OF AN ANOMALOUS RIDGE OVER
THE WRN CONUS. ASSOCIATED COLD FRONT REACHES THE OH VALLEY LATE
TODAY. INCREASING WINDS ALOFT AND LEADWAVE SHORTWAVE ENERGY WILL
PROVIDE DYNAMICAL FORCING FOR ASCENT OVER THE REGION...BUT DUE TO A
DRY AIR MASS PER BUFR SOUNDINGS AND PWATS AROUND 0.75 INCHES...WILL
ONLY SEE INCREASING MID-HIGH CLOUDS LATE TODAY. LOW-LEVEL
THICKNESSES INCREASE NEARLY 20 M TODAY THANKS TO SLY SFC WINDS OF
10-15 MPH AND SWLY LOW-LEVEL WINDS. H85 TEMPS WARM TO AROUND 12C.
TEMPS WARM INTO THE UPPER 60S TO LOW 70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
FLOW AMPLIFIES DURING THE SHORT TERM AS A BLOCKING PATTERN DEVELOPS
OVER THE ERN CONUS. ADDITIONAL ENERGY DIVES OVER THE GREAT LAKES
TUES THANKS TO A 100+ KT JET STREAK DIVING SWD FROM S CNTRL CANADA.
AS A RESULT...UPPER LOW PROGGED TO DEVELOP OVER THE GREAT LAKES INTO
THE NE STATES. THE UPPER LOW WILL PROGRESS SLOWLY EWD TUES NIGHT
INTO WEDS...LOCATING OFFSHORE LATE WEDS. ASSOCIATED SFC LOW DROPS
INTO THE NE STATES TONIGHT WITH A ATTENDANT COLD FRONT REACHING THE
LOCAL AREA EARLY TUES MORNING. MEANWHILE...AN INVERTED
TROUGH/COASTAL FRONT DEVELOPS ALONG/JUST OFF THE SE/MID-ATLANTIC
COAST AS THE SFC HIGH PUSHES WELL OFFSHORE. SHORTWAVE/HEIGHT FALLS
AND INCREASING WINDS ALOFT WILL PROVIDE FORCING FOR ASCENT ALONG THE
FRONT...BUT A MOISTURE STARVED AIR MASS WILL RESULT IN LITTLE MORE
THAN LIGHT SHOWERS OVER THE NW LOCAL AREA. BEST COVERAGE OF LIGHT
SHOWERS EXPECTED ALONG THE COASTAL FRONT TUES MORNING. THE STACKED
LOW CROSSES THE AREA TUES...LOCATING JUST OFF THE MID-ATLANTIC COAST
LATE TUES. VORTICITY MAXIMA ROTATING AROUND THE UPPER LOW WILL
CONTINUE TO PROVIDE UVM OVER THE REGION...BUT THE BEST CHANCES FOR
PRECIP WILL BE NEAREST THE SFC LOW/BEST MOISTURE OVER THE N AND NE
LOCAL AREA. AS THE LOW LOCATES OFFSHORE TUES NIGHT...BEST CHANCES
FOR PRECIP WILL BE OVER THE ERN SHORE. MOSTLY CLOUDY-CLOUDY
CONDITIONS TUES ACROSS THE N-NE TO PARTLY CLOUDY SW. HIGHS TUES
PROGGED IN THE UPPER 60S TO LOW 70S.

DEEP UPPER TROUGH/CLOSED LOW DROPS SOUTHEAST ACROSS THE REGION
ON WEDNESDAY. FORECAST SOUNDINGS DRY ALOFT OVER INLAND SECTIONS
AS THE TROUGH/SFC REFLECTION SWING OFFSHORE. WL THEREFORE KEEP
FORECAST DRY WEST OF I-95 ON WED, WITH LOW CHC POP FARTHER EAST
FOR SOME SCT SHRAS OVER COASTAL AREAS/ERN SHORE. HIGHS WED
REMAIN BELOW CLIMO NUMBERS...GENERALLY IN THE L-M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE WILL LIFT NE ALONG THE NEW ENGLAND COAST WED NIGHT THRU
FRIDAY. WILL CONTINUE TO CARRY CHANCE POPS (~30%) ACROSS FAR EASTERN
ZONES WED NIGHT...LOWERING TO SLIGHT CHC POPS (20%) OVER THE LOWER
MD EASTERN SHORE ON THURS. SFC HIGH PRESSURE CENTERED OVER THE GREAT
LAKES WILL GRADUALLY BUILD ACROSS THE LOCAL AREA BEHIND THE
DEPARTING COASTAL LOW LATE IN THE COMING WEEK. THE NEXT COLD FRONT
MOVES EASTWARD THROUGH THE GREAT LAKES ON SATURDAY...PUSHING INTO
THE MID-ATLANTIC REGION NEXT SUNDAY. DRY WX IS EXPECTED TO CONTINUE
INTO NEXT WEEKEND AS THE FRONT WILL BE MOISTURE-STARVED.
HIGHS THU 60-65...THEN FRI-SUN IN THE MID/UPR 60S. LOWS IN THE 40S
TO LOW 50S.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
DRY/VFR CONDITIONS PREVAIL TODAY AND TONIGHT...JUST SOME INCREASING
MID/HIGH CLOUDS ACRS THE REGION. LIGHT WINDS WILL BECOME S/SW TO
AROUND 10 KNOTS THIS AFTN.

OUTLOOK...NEXT FRONT AND LOW PRESSURE SYSTEM MOVES THROUGH TUESDAY
THEN LINGERS OFF THE COAST WEDNESDAY AND THURSDAY. SOME MVFR
CONDITIONS WILL BE POSSIBLE MAINLY TUE NIGHT AND WED MORNING ALONG
WITH A CHC FOR SHOWERS. WINDS FROM THE NW ARE EXPECTED TO BECOME
GUSTY WEDNESDAY AND THURSDAY...ESPECIALLY CLOSER TO THE COAST.

&&

.MARINE...
NO HEADLINES IN THE NEAR TERM...WITH HIGH PRESSURE OVERHEAD/MUCH
LIGHTER WINDS...AND COASTAL SEAS NOW 3-4 FT OR LESS THROUGHOUT THE
REGION. SFC HIGH PRESSURE SLIDES OFFSHORE LATER TODAY...ALLOWING
WINDS TO TURN TO THE S/SW. ALTHOUGH WINDS WILL INCREASE A BIT THIS
AFTN/EVENING...EXPECT SUB-SCA CONDITIONS TO PREVAIL WITH WIND SPEEDS
AVERAGING UP TO 15-20 KT ACRS NORTHERN COASTAL WATERS...GENLY 10-15
KT ELSEWHERE. NEXT COLD FRONT WILL SLOWLY CROSS THE WATERS LATE TUE
AFTN/EVENING...FOLLOWED BY EVENTUAL SCA CONDITIONS AS SFC LOW
PRESSURE THEN DEEPENS OFF THE COAST. WITH SYSTEM EXPECTED TO STALL
OFFSHORE THRU THE END OF THE WEEK...A PROLONGED PERIOD OF SCA
CONDITIONS IS LIKELY. WITH FLOW BEING OFFSHORE FROM THE NW...SEAS
WOULD TEND TO STAY CAPPED AT 5-6 FT AND TIDAL FLOODING IS NOT
EXPECTED.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MAM
NEAR TERM...SAM
SHORT TERM...MAM/SAM
LONG TERM...JDM
AVIATION...LKB
MARINE...LKB





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