Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 230536
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
136 AM EDT SAT MAY 23 2015

.SYNOPSIS...
A COLD FRONT CROSSES THE AREA TONIGHT FOLLOWED BY HIGH PRESSURE
BUILDING IN FOR SATURDAY. THE HIGH WILL SLIDE OFFSHORE AND REMAIN
JUST OFF THE COAST THROUGH EARLY TO MID NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST SFC ANALYSIS REVEALS WEAK LOW PRESSURE OVER THE CANADIAN
MARITIMES WITH AN ATTENDANT COLD FRONT STRETCHING SWWD OVER NRN VA.
THIS FRNT WILL DROP THRU THE AREA LATE THIS EVENG AND
OVERNIGHT...WITHOUT ANY PCPN AND ONLY A FEW CLOUDS AS THE COLUMN
REMAINS QUITE DRY (1000-500 MB RH LESS THAN 40%). SFC HI PRES WILL
THEN QUICKLY BLD IN BEHIND THE FRNT LATE TNGT. CALM WINDS THIS
EVENING BECOME NLY 5-10 KT BEHIND THE FRONT...SLOWING THE TEMP
DESCENT. LOWS RANGE FROM THE MID 40S TO MID 50S (~-1 STD DEV).

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SHORT TERM PERIOD WILL BE CHARACTERIZED BY DRY WX WITH INCREASING
TEMPS AND HUMIDITY THRU THE PERIOD. SFC HI PRES WILL CENTER
DIRECTLY OVER THE MID ATLC BY MIDDAY SAT...THEN SLIDE OFFSHORE
LATE IN THE DAY AS ONSHORE FLOW DEVELOPS. LIKE FRI...TEMPS WILL
ONLY MAX OUT IN THE LO TO MID 70S UNDER A SUNNY SKY.

WARMING TREND BEGINS SUN AND MON AS SLY FLOW DEVELOPS WITH THE HI
OFFSHORE AND AN UPR-LEVEL RIDGE AMPLIFYING ACROSS THE ERN
SEABOARD. EXPECT HI TEMPS SUN IN THE UPR 70S TO LWR 80S...AND THE
MID TO UPR 80S MON.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MEDIUM RANGE CONTINUES TO APPEAR TO BE DOMINATED WITH A STRONG UPPER
LEVEL RIDGE CENTERED OVER THE SE/MID ATLC STATES THROUGH THE
PERIOD. LATEST ECMWF/GFS REMAIN IN FAIRLY GOOD AGREEMENT...WITH
THE GFS STILL A BIT MORE AGGRESSIVE AT BREAKING DOWN/WEAKENING
THE RIDGE BY MID TO LATE WEEK (THOUGH NOT TO THE EXTENT IT HAD
BEEN OVER THE PAST FEW DAYS). MODELS ALSO DIFFER SOMEWHAT WITH
RESPECT TO 850 MB TEMPERATURES...THE ECMWF REMAINING WARMER BY
ABOUT 2-3 C THAN THE GFS. OVERALL...THIS PATTERN WILL LEAD TO WARM
/SUMMER- LIKE WX THROUGH THE ENTIRE PERIOD...WITH VERY MINIMAL
CHANCES FOR RAIN...LIMITED TO ISOLATED/WIDELY SCATTERED MAINLY
LATE AFTN OR EVENING TSTMS DEVELOPING TO OUR NORTH AND WEST
DRIFTING INTO THE REGION. HAVE DROPPED POPS ALTOGETHER FOR MON
NIGHT THROUGH MIDDAY WED...THEN WILL HAVE JUST 20% POP OVER JUST
THE FAR NW PORTIONS OF THE CWA ON WED...AND GENLY A 20% POP IN THE
LATE AFTN/EVENING OVER MUCH OF THE AREA THU/FRI (UP TO 30% FAR
NW). INCREASING HUMIDITY AND HIGH TEMPS WARMING BACK TO THE UPPER
80S TO LOWER 90S THROUGH THE PERIOD...FAVORING ECMWF FOR HIGHS
(GFS HIGHS ONLY IN MID 80S WELL INLAND APPEARS TOO COOL IN THIS
PATTERN). CONDITIONS WILL GENLY BE ABOUT 5 DEGREES COOLER AT THE
COAST. LOWS AVG IN THE MID 60S TO LWR 70S THROUGH THE PERIOD.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WEAK COLD FRONT IS BEGINNING TO SAG SWD INTO THE MID ATLANTIC
REGION AS OF 23/0500Z AND WILL CONTINUE TO PUSH SSEWD DURING THE
OVERNIGHT HOURS...CROSSING ALL TERMINALS. ANY GUSTINESS ASSOCIATED
WITH THE FRONTAL PASSAGE WILL BE LIMITED TO KORF...WHERE NORTH
WINDS OFF CHES BAY WILL OCCUR CLOSER TO DAYBREAK (OR BTWN
23/0900-1100Z). OTHERWISE...HIGH PRESSURE BUILDS OVER THE REGION
BY THIS AFTN AND REMAINS INVOF THE COAST THROUGH SATURDAY NIGHT
BEFORE MOVING OFFSHORE SUNDAY AND REMAINING ANCHORED OFF THE COAST
THROUGH WEDNESDAY. VFR CONDITIONS SHOULD PREVAIL DURING THIS TIME
PERIOD.

&&

.MARINE...
WINDS DIMINISHING ACRS THE AREA THIS AFTN...CURRENT CONDS ARE
BELOW SCA THRESHOLDS ALL ZONES. HOWEVER...ANOTHER COLD FRONT IS
APPROACHING THE NRN MID ATLC REGION...AND WILL DROP SOUTH THROUGH
THE WATERS LATER TONIGHT. NOT NEARLY AS STRONG AS WHAT OCCURRED
LAST NIGHT AS THE PRESSURE GRADIENT IS WEAK...BUT SHOULD BE ENOUGH
TO YIELD LOW END SCA CONDITIONS FOR THE BAY AFTER MIDNIGHT THROUGH
11-14Z/FRI MORNING. HAVE RAISED ANOTHER ROUND OF SCA HEADLINES FOR
THE BAY...BEGINNING AT 05Z/FRI...AND LASTING THROUGH 11Z N OF NEW
PT COMFORT...AND THROUGH 14Z SOUTH OF NEW PT COMFORT (05Z MAY BE A
TAD EARLY FOR THESE LOWER BAY ZONES BUT DID NOT WANT TO GET TOO
SPECIFIC ATTM). DID NOT RAISE ANY HEADLINES FOR OTHER ZONES AS IT
LOOKS SOMEWHAT MARGINAL EVEN FOR THE BAY...ALTHOUGH A FEW GUSTS TO
AROUND 20 KT MAY AFFECT THE RIVERS. SEAS ON THE COASTAL WATERS
BUILD TO 4 FT IF THAT (AND THIS IS GOING WELL ABOVE WAVE WATCH
WHICH KEEPS SEAS CAPPED AT 2-3 FT).

PRESSURE GRADIENT SLACKENS QUICKLY SATURDAY AND EXPECT WINDS TO
AGAIN DROP OFF QUICKLY BY LATE MORNING AS THE HIGH BUILDS
OVERHEAD. WINDS SHIFT TO THE S/SE SAT NIGHT INTO SUN AS THE HIGH
SHIFTS OFF THE COAST. WINDS SHOULD THEN FOLLOW A DIURNAL
PATTERN...INCREASING A BIT MAINLY IN THE LATE AFTN/EVENING/EARLY
AM HRS LATE SUN THROUGH MIDWEEK AS UPPER RIDGE DEVELOPS WITH SFC
HIGH PRESSURE WELL OFF THE COAST. CONDITIONS WILL GENLY REMAIN
SUB-SCA THOUGH SOUTHERLY FLOW MAY GUST TO NEAR 20 KT IN THE BAY
DURING THIS LATE AFTN/EVENING/EARLY AM TIMEFRAME.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ630-
     631.

&&

$$
SYNOPSIS...MAS
NEAR TERM...MAS/SAM
SHORT TERM...MAS
LONG TERM...LKB
AVIATION...BMD
MARINE...LKB



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