000
FXUS61 KLWX 040002
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
759 PM EDT FRI SEP 3 2010

.SYNOPSIS...
HURRICANE EARL CURRENTLY WELL EAST OF THE DELMARVA AND WILL
CONTINUE TO TRACK NORTHEAST OFF THE NEW ENGLAND COAST THROUGH
TONIGHT. COOLER AND LESS HUMID CONDITIONS ARE IN STORE FOR THE
LABOR DAY WEEKEND ONCE A COLD FRONT PUSHES THROUGH THE REGION THIS
EVENING. WARM TEMPERATURES WILL RETURN BY THE MIDDLE OF NEXT WEEK
AS HIGH PRESSURE BEGINS TO MOVE OFF THE COAST.

.NEAR TERM /UNTIL 6AM SATURDAY/...
SURFACE ANALYSIS SHOWS COLD FRONT JUST ABOUT TO CROSS THE BLUE RIDGE
MOUNTAINS THIS EVENING. SCATTERED SHOWERS HAVE MOVED IN AHEAD OF THE
BOUNDARY...BUT CONTINUE TO WEAKEN AS THEY MOVE EASTWARD. NOT
EXPECTING MUCH PRECIP TO MAKE IT TO THE METRO AREAS...BUT SCT
SHOWERS ARE POSSIBLE ACROSS THE CENTRAL FOOTHILLS AND NORTHERN
VIRGINIA PIEDMONT. GUSTY WIND SHIFT ASSOCIATED WITH THE
BOUNDARY...WITH GUSTS UP TO AROUND 25 KT FROM THE W/NW BEHIND THE
FRONT. GUSTS SHOULD LAST A COUPLE OF HOURS BEHIND THE BOUNDARY...AND
THEN DIMINISH OVERNIGHT. WINDS WONT BE CALM...BUT SHOULD BE AOB
10KT THROUGH SUNRISE.

HAVE ADJUSTED THE HOURLY TEMPS AGAIN TONIGHT...AS CLOUD COVER HAS
HELPED KEEP TEMPERATURES STEADY. OTHERWISE...NO MAJOR CHANGES TO THE
FORECAST.

.SHORT TERM /6AM SATURDAY THROUGH 6 PM SATURDAY/...
FORTUNATELY FOR THE MID ATLC - WE/LL SEE HIGH TEMPS AT LEAST
10-15 DEGREES LOWER THAN IN THE PAST FEW DAYS AND DRIER /MUCH LESS
HUMID/. THIS WILL BE A TASTE OF FALL...WHICH OF COURSE ALSO COMES
W/ A DRY WNWLY WIND AND SATURDAY WILL BE NO EXCEPTION. BEHIND THE
COLD FRONT THAT WILL EXIT OFF THE COAST OVERNIGHT...WILL BE THE
BASE OF AN UPPER LEVEL LOW PRESSURE SYSTEM OVER SERN CANADA. THIS
FEATURE WILL MIX-DOWN GUSTY WINDS TO THE SFC INTO THE 20-30MPH
RANGE FROM LATE MORNING TILL EARLY EVE. HIGHS WILL ONLY PEAK INTO
THE U70S ACROSS THE WEST AND NEAR 80 OVER THE VA/MD PIEDMONT-I-95
CORRIDOR. ELEVATED CONCERNS FOR FIRE WX ANOTHER RESULT OF THIS
GUSTY/DRY DAY. SEE FIRE WX SECTION BELOW.

HIPRES WILL SETTLE OVER THE AREA SAT NGT AND REMAIN OVERHEAD THRU
THE REST OF THE WEEKEND. WITH HIPRES MOVING IN...THE WEAKENING
PRESSURE GRADIENT WILL ALLOW FOR WINDS TO BECOME CALM ACROSS MUCH OF
THE AREA. THE COMBINATION OF LIGHT WINDS AND CLEAR SKIES WILL ALLOW
PROVIDE IDEAL RADIATIONAL CONDITIONS. IN A DRY AIRMASS LIKE THE ONE
WE WILL BE IN THIS WEEKEND WILL ALLOW FOR TEMPS TO DROP CLOSE TO THE
DEWPOINT. AS A RESULT...PARTS OF THE CWFA MAY SEE THE LOWEST
READINGS SAT NGT SINCE EARLY JUNE...WITH LOWS IN THE 40S WEST OF
I-95...50S ALONG AND TO THE EAST. A FEW COLD SPOTS IN THE HIGHER
TERRAIN ALONG AND WEST OF THE ALLEGHENY FRONT MAY BOTTOM INTO THE
UPPER 30S.

PLENTY OF LATE SUMMER SUNSHINE WILL HELP TEMPERATURES REBOUND ON SUN
WITH HIGHS IN THE MID TO UPPER 70S...SLIGHTLY COOLER ACROSS THE
RIDGE TOPS.

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
DRY CONDITIONS THAT THE AREA HAS EXPERIENCED THE LAST 1-2 WEEKS WILL
PERSIST THRU MOST OF THE LONG-TERM PERIOD. REGIONAL WEATHER PATTERN
FOR ERY NEXT WEEK WILL BE DOMINATED BY A LARGE RIDGE OVER THE
SOUTHEAST AND MID-ATLANTIC STATES. THE CENTER OF SFC HIPRES WILL
BEGIN TO MOVE OFF THE COAST MON WHILE THE H8 RIDGE AXIS MOVES EAST
OF THE AREA. ACCORDINGLY...SOUTHERLY RETURN FLOW WILL ADVECT WARMER
AIR BACK INTO THE REGION MON-WED. HIGHS APPROACHING 90 DEGREES COULD
RETURN TUE AND WED.

AN AREA OF LOPRES IS FORECASTED TO TRACK ACROSS THE UPPER GREAT
LAKES REGION AND SRN ONTARIO/QUEBEC DURING THE MIDDLE OF NEXT WEEK.
AN ASSOCIATED COLD FRONT WILL PUSH THRU THE REGION ON WED...BRINGING
ANOTHER PUSH OF COOLER AIR BEHIND THE FRONT FOR THE END OF THE WEEK.
MOST OF THE DYNAMICS WITH THE FRONT WILL BE LOCATED WELL TO THE
NORTH OF THE AREA...CLOSER TO THE LOW WHILE ANY MOISTURE SOURCE FROM
THE GULF OF MEXICO WILL BE CUTOFF FROM THE RIDGE OVER THE SOUTHEAST
CONUS. THEREFORE...NOT MUCH PRECIP IS EXPECTED WITH THE
FROPA...BRINGING LITTLE IF ANY RELIEF TO THE ONGOING DROUGHT
CONDITIONS ACROSS THE ERN WV PANHANDLE...CENTRAL VA AND CENTRAL MD.

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL CONTINUE ACROSS THE TERMINALS OVERNIGHT. SCT
SHOWERS HAVE DEVELOPED WEST OF THE BLUE RIDGE...BUT ARE STRUGGLING
TO MAKE IT EASTWARD. GOOD WINDSHIFT BEHIND THE FRONT...WITH W/NW
WINDS EXPECTED. GUSTS TO AROUND 25KT EXPECTED FOR AN HOUR OUR TWO
BEHIND THE BOUNDARY...BUT SHOULD DIMINISH TO AOB 10 KT FOR THE
REMAINDER OF THE OVERNIGHT HOURS. SOME PATCHY MVFR FOG IS POSSIBLE
NEAR KCHO.

WINDS WILL BRIEFLY GUST NEAR 20KT FOR A PERIOD INTO THE EARLY
MORNING HRS...DISSIPATING TILL MID MORNING SAT. WINDS WILL AGAIN
INCREASE W/ THE PASSAGE OF A POTENT UPPER LOW WELL TO THE NORTH.
WINDS AT THE SFC WILL GUST 20-25KT PERIODICALLY THROUGHOUT THE
AFTN HRS AND AGAIN SUBSIDE CLOSER TO SUNSET SAT EVE.

GUSTY WINDS WILL WEAKEN SAT NGT AS HIPRES BUILDS OVER THE AREA.
VFR CONDITIONS EXPECTED SUN THRU THE MIDDLE OF NEXT WEEK AS
HIPRES REMAINS OVERHEAD.

.MARINE...
ADJUSTED THE SMALL CRAFT ADVISORY BACK A COUPLE OF HOURS EARLIER
THIS EVENING. WIND GUSTS BEHIND THE COLD FRONT HAVE RANGED FROM
20-25 KT THIS EVENING. THE COLD FRONT IS CURRENTLY CROSSING THE BLUE
RIDGE MOUNTAINS...AND WILL CONTINUE ACROSS THE WATERS OVERNIGHT. A
BRIEF LULL IN SCA CONDITIONS MAY OCCUR A COUPLE OF HOURS AFTER
FROPA...BUT WINDS WILL PICK UP AGAIN TOWARDS SUNRISE.

AN UPPER LEVEL TROF WILL DRIFT OVER THE REGION ON SAT...BRINGING
MORE SCA CONDITIONS OVER THE WATERS WELL INTO THE EVE HRS.

SCA HAS BEEN EXTENDED INTO SAT NGT FOR THE LOWER TIDAL POTOMAC AND
THE CHSPK BAY FROM POOLES ISLAND SOUTHWARD. STRONGER WIND GUSTS WILL
STILL BE ABLE TO MIX DOWN AFTER SUNSET WITH STEEP LAPSE RATES ABOVE
THE WARM WATERS. THE PRESSURE GRADIENT WILL GRADUALLY WEAKEN LATE
SAT NGT AS HIPRES SETTLES ACROSS THE WATERS...WITH WINDS DROPPING
BELOW 20 KT BY ERY SUN MRNG.

NO MARINE HEADLINES SUN THRU ERY NEXT WEEK WITH HIPRES OVERHEAD.

.FIRE WEATHER...
ELEVATED FIRE WX CONCERNS ON SATURDAY...RESULTING FROM A
COMBINATION OF DROUGHT CONDITIONS ACROSS NRN VA/WRN MD AND THE WX
PANHANDLE...GUSTY WINDS BEHIND A COLD FRONT AND DRY DEWPOINTS SAT
AFTN. WEST-NORTHWESTERLY WINDS WILL INCREASE A COUPLE OF HRS AFTER
SUNRISE INTO THE SUSTAINED 15-20 MPH W/ GUSTS OF 20-30 MPH WELL
INTO THE AFTN HRS...DISSIPATING BY THE MID-LATE EVE.

.CLIMATE...
DCA HIT 91 DEGREES TODAY...THE 60TH 90 DEGREE OR HIGHER DAY IN 2010.
THIS IS THE SECOND GREATEST NUMBER OF 90 DEGREE OR HIGHER DAYS SINCE
RECORDS BEGAN IN 1872 WITH 1980 HOLDING THE RECORD AT 67 SUCH DAYS.

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR
     ANZ531534-537-539541-543.
     SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR ANZ530-535-
     536-538-542.

UPDATE...LISTEMAA