weather.gov     
National Weather Service

Area Forecast Discussion
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  
   31  32  33  34  35  36  37  38  39  40  41  
[Printable]
817
FXUS61 KLWX 170127 AAB
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
927 PM EDT TUE SEP 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE REGION THROUGH WEDNESDAY. A WEAK
COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY NIGHT INTO
THURSDAY. HIGH PRESSURE WILL RETURN FOR FRIDAY AND SATURDAY BEFORE
MOVING OFF THE COAST SUNDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THE MOST PRONOUNCED KINK IN THE UPPER LEVEL FLOW OF A LARGER-SCALE
UPPER TROUGH HAS BEEN WELL TO OUR SOUTH OVER THE PAST FEW HRS...
CLOSER TO THE VA/NC BORDER. THE FEATURE HAS HELPED DEVELOP SOME
CONVECTION ACROSS THE CAROLINAS...AND EVEN A WEAK FRONTAL BOUNDARY
OVER CNTRL VA HAD SOME LIGHT SHOWERS ALONG IT EARLIER THIS EVE.
FAIR WX STRATUS CLOUD BATCHES HAVE BEEN COMMON ACROSS OUR REGION
DURING THE SECOND HALF OF THE DAY...WHICH ARE NOW DISSIPATING AND
WILL GIVE US A MAINLY CLEAR OVERNIGHT PERIOD.

THE ERN HALF OF THE CONUS IS ESSENTIALLY UNDER THIS LARGE UPPER
TROUGH THAT HAS BEEN SPILLING COLD/COOL AND DRY CANADIAN AIR DOWN
INTO THE NRN HALF OF THE US FOR THE PAST COUPLE OF DAYS. THE MID-
ATLC IS NOW NEARLY ON THE BACK SIDE OF THE TROUGH AXIS...W/ HIGH
PRESSURE BUILDING IN AT THE SFC FROM THE UPPER MIDWEST. THIS WILL
CONTINUE OUR QUIET/TRANQUIL CONDITIONS THRU THE REMAINDER OF THE
WORK WEEK.

PREV DISC...
MIN TEMPS WILL RANGE FROM THE UPPER 30S OVER THE ALLEGHENY
HIGHLANDS WHERE RADIATIONAL COOLING IS EXPECTED...TO THE UPPER 50S
AND LOWER 60S IN DOWNTOWN WASHINGTON AND BALTIMORE. PATCHY FOG IS
EXPECTED OVERNIGHT...BUT IT WILL NOT BE WIDESPREAD DUE TO THE DRY
ADVECTION CURRENTLY IN PLACE.

WEDNESDAY...
HIGH PRESSURE WILL GRADUALLY SHIFT TOWARD THE COAST BUT MORE DRY
CONDITIONS ARE EXPECTED WITH MAX TEMPS SLIGHTLY BELOW CLIMO...
RANGING FROM THE 60S IN THE POTOMAC HIGHLANDS TO THE MIDDLE 70S
NEAR WASHINGTON AND BALTIMORE. A SCT-BKN CU DECK WILL DEVELOP
DURING THE LATE MORNING AND AFTERNOON HOURS...BUT CLOUDS MAY BE
MORE WIDESPREAD ACROSS PORTIONS OF CENTRAL VIRGINIA AND SOUTHERN
MARYLAND WHERE OVERRUNNING WILL CONTINUE WELL BEHIND A COLD FRONT
OVER THE SOUTHEASTERN CONUS.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A WEAK COLD FRONT WILL PASS THROUGH THE REGION WEDNESDAY NIGHT
INTO THURSDAY. LITTLE MOISTURE OR FORCING WILL BE ASSOCIATED WITH
THE FRONT SO IT WILL HAVE LITTLE TO NO IMPACT AS IT MOVES THROUGH.
A STRAY SHOWER CANNOT BE RULED OUT...BUT ANY SHOWER COVERAGE WILL
BE QUITE LIMITED SO THE FORECAST REMAINS DRY FOR NOW. HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT FOR THURSDAY NIGHT AND
FRIDAY...BRINGING DRY CONDITIONS AND BELOW NORMAL TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE OVER NEW ENGLAND WILL WEDGE ITSELF SOUTHWARD BETWEEN
THE APPALACHIAN MOUNTAINS AND EAST COAST FRIDAY NIGHT THROUGH
SATURDAY NIGHT...KEEPING DRY CONDITIONS IN THE REGION.

A COLD FRONT WILL MOVE FROM THE EASTERN GREAT LAKES TO THE EAST
COAST SUNDAY AND SUNDAY NIGHT. THERE IS A CHANCE FOR SHOWERS AND A
FEW THUNDERSTORMS AHEAD OF AND ALONG THE FRONT WEST OF THE BLUE
RIDGE SUNDAY AND IN ALL AREAS SUNDAY NIGHT. BECAUSE THE INITIAL PUSH
OF UPPER LEVEL SUPPORT LOOKS TO PIVOT NORTHEAST INTO EASTERN CANADA
BY SUNDAY NIGHT...THE FRONT COULD STALL ACROSS THE DELMARVA
PENINSULA AND TIDEWATER OF VIRGINIA BRIEFLY.

A REINFORCING PUSH OF UPPER LEVEL ENERGY MONDAY SHOULD PUSH THE
FRONT OFFSHORE BY LATE MONDAY. HIGH PRESSURE WILL GRADUALLY BUILD
INTO THE REGION MONDAY NIGHT AND TUESDAY TO ALLOW FOR THE NEXT PUSH
OF COLDER AIR TO ARRIVE IN TIME FOR MIDWEEK ACTIVITIES.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH WEDNESDAY.
PATCHY BR MAY BRIEFLY REDUCE VSBYS LATE TONIGHT INTO EARLY
WEDNESDAY...ESPECIALLY ACROSS KCHO AND KMRB.

A WEAK COLD FRONT WILL PASS THROUGH THE TERMINALS WEDNESDAY NIGHT
INTO THURSDAY BEFORE HIGH PRESSURE RETURNS FOR LATER THURSDAY
THROUGH FRIDAY. VFR CONDITIONS ARE EXPECTED MOST OF THE TIME...BUT
PATCHY BR MAY BRIEFLY REDUCE VSBYS DURING THE LATE NIGHT AND EARLY
MORNING HOURS.

VFR CONDITIONS FRIDAY NIGHT THROUGH SATURDAY WITH LIGHT AND
VARIABLE WINDS AS HIGH PRESSURE HUGS THE EASTERN SEABOARD.

&&

.MARINE...
WINDS DIMINISH TONIGHT AS HIGH PRESSURE BUILDS OVER THE WATERS.
HOWEVER...GUSTS AROUND 15 KNOTS ARE EXPECTED ALONG THE MARYLAND
CHESAPEAKE BAY AND LOWER TIDAL POTOMAC RIVER AS NORTHERLY WINDS
CHANNEL.

HIGH PRESSURE WILL SLOWLY DRIFT EAST WEDNESDAY BEFORE A COLD FRONT
MOVES THROUGH LATE WEDNESDAY NIGHT INTO THURSDAY. THE GRADIENT
SHOULD BE WEAK ENOUGH DURING THIS TIME FOR NO MARINE HEADLINES.
HOWEVER...A PRESSURE SURGE AHEAD OF BUILDING HIGH PRESSURE MAY
CAUSE WIND TO GUST PAST SCA CRITERIA FOR PORTIONS OF THE WATERS
THURSDAY NIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD OVERHEAD FOR
THE WEEKEND.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KLW








U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE