Area Forecast Discussion
Issued by NWS Wakefield, VA

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000
FXUS61 KAKQ 210904
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
504 AM EDT TUE OCT 21 2014

.SYNOPSIS...
LOW PRESSURE MOVES THROUGH THE REGION TODAY...AND PUSHES OFF THE
COAST TONIGHT. THE LOW WILL INTENSIFY WHILE SLOWLY TRACKING NORTHEAST
OFF THE MID ATLANTIC COAST THROUGH FRIDAY. COOL AND UNSETTLED CONDITIONS
WILL PREVAIL ON WEDNESDAY...FOLLOWED BY DRIER CONDITIONS AND BREEZY
NORTHWEST WINDS THURSDAY INTO FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS SHOWING SFC LOW PRESSURE OVER LAKE ONTARIO WITH A
TRAILING SFC COLD FRONT EXTENDING SW FROM THE LOW DOWN THROUGH THE
OH VALLEY. WEAK/ELONGATED SHORTWAVE ALOFT IS PUSHING EAST ACRS THE
CWA AND HAS ALLOWED FOR ENOUGH LIFT TO DEVELOP SOME VERY LIGHT
SHOWERS/SPRINKLES OVER THE REGION (GENLY TOO DRY IN LOW LEVELS FOR
ANYTHING MEASURABLE THUS FAR). MOISTURE WILL TEND TO DIMINISH FROM W
TO E THROUGH 12Z AS DRY SLOT PUSHES BACK IN FROM THE SW BUT WILL
MAINTAIN 20% POPS E OF I-95 THROUGH 12Z.

AFTER 12Z...WILL TEND TO SALVAGE A PRETTY NICE DAY ACRS MOST OF THE
LOCAL AREA AS SKIES BECOME PARTLY TO MOSTLY SUNNY AND WINDS SHIFT TO
THE WEST. WITH TEMPERATURES STARTING OFF MUCH MILDER THAN YESTERDAY
MORNING...SUN AND MIXING SHOULD ALLOW FOR FAIRLY RAPID WARMING
THROUGH THE 60S AND INTO THE LOWER 70S BY EARLY AFTN. WITH A STRONG
SHORTWAVE CURRENTLY SEEN ON WV SATELLITE OVER THE WESTERN GREAT
LAKES PROGGED TO DIVE SE AROUND THE BASE OF THE AMPLIFYING UPPER
LOW...EXPECT INCREASING CLOUDS FROM NW TO SE THIS AFTN. HIGH RES
MODELS SHOWING A FAIRLY SIGNIFICANT AMOUNT OF SIMULATED REFLECTIVITY
ACRS NW PORTIONS OF THE CWA AFTER 18Z...GRADUALLY ADVECTING THIS SE
TO THE COAST PRIOR TO 00Z THIS EVENING. DUE TO DRY LOW LEVELS (DEW
PTS IN 40S)...EXPECT THAT RADAR COVERAGE THIS AFTN WILL LOOK MORE
IMPRESSIVE THAN REALITY AND THUS WILL KEEP POPS CAPPED IN CHANCE
RANGE...AROUND 40% ACRS THE NORTH AFTER 20Z...TAPERED TO 20% OR
LOWER ACRS THE SOUTH. QPF AMOUNTS WILL BE LIGHT...< .10". HIGHS
TODAY WILL RANGE FROM THE MID TO UPPER 70S ACRS THE FAR SE (WHERE
CLOUDS ARE SLOWER TO PUSH IN THIS AFTN)...TO THE UPPER 60S/AROUND 70
F OVER THE NW DUE TO EARLIER ONSET OF CLOUDS AN POTENTIAL SHOWERS.
ALSO...DUE TO THE LOW DEW PTS...IF MEASURABLE RAINFALL DOES
OCCUR...TEMPS LATE THIS AFTN WOULD POTENTIALLY DROP INTO THE LOWER
60S OR COOLER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
FLOW CONTINUES TO AMPLIFY THROUGH THE PERIOD AS A BLOCKING
PATTERN DEVELOPS OVER ERN CANADA. THE UPPER LOW WILL PROGRESS
SLOWLY EWD OVERNIGHT INTO WED...LOCATING OFF THE DELMARVA COAST
LATE WED. WITH THE UPR LOW PIVOTING ACROSS THE LOCAL AREA TONIGHT...WILL
SEE A BETTER CHANCE FOR SHOWERS DEVELOP ESPECIALLY NORTH/NE WHERE
BEST UPWARD MOTION IS ANTICIPATED. LAPSE RATES ALOFT ARE FAIRLY
IMPRESSIVE (H5 TO H7 LAPSE RATES OF 6.5 TO 7C) AND IF IT WERE
SPRING WOULD ADD TSTMS TO THE FORECAST. LOW LEVELS ARE PROGGED TO
BE FAIRLY STABLE HOWEVER SO FOR NOW HAVE KEPT TSTMS OUT OF FORECAST
BUT CERTAINLY COULD HAVE SOME ELEVATED TSTMS AND WILL CONTINUE TO
MONITOR TRENDS. HAVE BUMPED POPS UP TO LIKELY IN THESE
AREAS...TAPERED TO LOWER CHANCES FARTHER S/W WHERE DEEP MOISTURE
IS GENLY NOT PRESENT. LOWS TONIGHT IN THE UPPER 40S TO MID 50S.

DEEP UPPER TROUGH/CLOSED LOW SLOWLY MOVES EAST AND OFFSHORE WED.
AFTER A BRIEF INCREASE IN DEEP MOISTURE BETWEEN 09-15Z...FORECAST
SOUNDINGS FAIRLY DRY ALOFT OVER INLAND SECTIONS AS THE TROUGH/SFC
REFLECTION SWING FARTHER OFFSHORE...HOWEVER A FAIRLY SHARP
MOSITURE GRADIENT PROGGED ALONG THE COAST. THE ERN SHORE IN
PARTICULAR APPEARS TO BE SET FOR A CLOUDY/COOL DAY WITH SHOWERS
LIKELY AT LEAST THROUGH THE MORNING HRS. WILL THEREFORE KEEP CHC POPS
LIMITED TO AREAS MAINLY ALONG AND NE OF THE I-64 CORRIDOR
WED...WITH EMPHASIS OF 60-70% POPS ON THE EASTERN SHORE. COULD END
UP BEING DRY OVER FAR SW ZONES. QPF AMOUNTS WILL AVG 0.25-0.50" ON
THE ERN SHORE...GENLY ONLY AROUND .10" OR LESS ELSEWHERE. FAVOR
COOLER END OF GUIDANCE FOR HIGHS...MID 60S SW TO AROUND 60/LOWER
60S NE. OTHER FEATURE TO NOTE WILL BE THE INCREASING NW WINDS BY
AFTN AS THE SFC LOW INTENSIFIES FAIRLY RAPIDLY OFF THE COAST.
GUSTS TO 25-35 MPH WILL BE POSSIBLE BY LATER AFTN/EVENING.

THE CLOSED LOW MOVES FARTHER NE WED NIGHT INTO THU...LOCATING OFF
THE NEW ENGLAND COAST BY 00Z FRIDAY. ANY LEFTOVER SHOWER CHANCES
BY THEN WILL BE LIMITED TO THE EASTERN SHORE (20%). DECREASING
CLOUDS ARE ALSO EXPECTED ACROSS INTERIOR VA. LOWS WED NIGHT IN THE
LOW 40S TO LOW 50S. COOL AGAIN THU ALTHOUGH WITH A BIT MORE SUN
SHOULD SEE HIGHS INTO THE MID-UPPER 60S WELL INLAND WITH HIGHS
ONLY IN THE LOWER 60S FARTHER NE. PRESSURE GRADIENT WILL REMAIN
TIGHT IN BETWEEN SUB 1000 MB SFC LOW OFF LONG ISLAND AND 1020 MB
SFC HIGH OVER THE OH/TN VALLEY. EXPECT BREEZY TO WINDY CONDITIONS WITH
GUSTS TO 35 MPH ACRS THE ERN SHORE...AROUND 30 MPH ELSEWHERE.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
LOW PRESSURE LIFTS TO THE NE THURSDAY NIGHT THROUGH SATURDAY AS
UPPER RIDGING EXPANDS EASTWARD FROM THE CENTRAL US. A WEAK TROUGH
CLIPS THE NRN MID-ATLANTIC SATURDAY NIGHT AND QUICKLY MOVES OFF THE
COAST SUNDAY. MID/UPPER LEVEL RIDGING BUILDS OVER THE ERN US EARLY
NEXT WEEK. OVERALL...DRY CONDITIONS SHOULD PREVAIL THROUGH THE
MEDIUM RANGE PERIOD. HIGH TEMPERATURES SHOULD AVERAGE IN THE MID 60S
TO AROUND 70 FRIDAY AND SATURDAY...AND TREND UPWARD INTO THE UPPER
60S TO LOW 70S SUNDAY...AND POTENTIALLY 70-75 BY MONDAY. LOWS SHOULD
RANGE FROM THE LOW/MID 40S NW...TO THE LOW/MID 50S FOR SE COASTAL
LOCATIONS.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
EXPECT MAINLY VFR CONDITIONS TODAY INTO THIS EVENG OVR THE TAF
SITES...WITH PERIODS OF MID LVL CLOUDINESS...AS A WEAK COLD FRONT
MOVES ACRS THE AREA. LATER TNGT THRU THU...LO PRES WILL INTENSIFY
OFF THE NEW JERSEY AND NEW ENGLAND CSTS. THERE WILL BE A CHC FOR
SHOWERS AND MVFR CIGS...ESPLY OVR NRN AND ERN PORTIONS LATE TNGT
INTO WED NGT. MVFR CIGS MAY LINGER INTO EARLY THU AT SBY. THE LO
PRES SYSTEM WILL MOVE FARTHER AWAY TO THE NE AND HI PRES BLDS IN
FM THE NNW THU NGT INTO SUN.

&&

.MARINE...
BASED ON LATEST MODEL GUIDANCE...AND ASSOCIATED WIND SPEEDS FM THE
NW STARTING WED AFTN DUE TO INTENSIFYING LO PRES OFF THE CST...HAVE
HOISTED SCA`S FOR ALL WTRS STARTING WED AFTN AND WILL MAINTAIN THEM
THRU AT LEAST THU AFTN FOR NOW. AT THIS TIME...HAVE GUSTS TO ARND 30
KT OVR THE CHES BAY ZNS AND CSTL ZNS FM EARLY WED EVENG THRU THU.
WITH FLOW BEING OFFSHR FM THE NW...SEAS WOULD TEND TO STAY CAPPED AT
5-6 FT AND TIDAL FLOODING IS NOT EXPECTED. N/NW FLOW IS EXPECTED TO
CONTINUE INTO NEXT WEEKEND WITH SPEEDS DIMINISHING TO 10-15 KT AND
SEAS SUBSIDING.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM WEDNESDAY TO 5 PM EDT THURSDAY
     FOR ANZ630>638-650-652-654-656-658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ
AVIATION...TMG
MARINE...AJZ/TMG






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