FXUS61 KLWX 061418
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1018 AM EDT MON OCT 6 2008
.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THE REGION TODAY. HIGH PRESSURE WILL
BUILD IN BEHIND THIS FRONT FOR THE MIDDLE PART OF THE WEEK. THE NEXT
STORM SYSTEM WILL APPROACH THE REGION FROM THE WEST BRINGING A
RETURN OF UNSETTLED CONDITIONS LATE IN THE WEEK AND POSSIBLY INTO
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAK FRONT ALONG WITH MID LEVEL SHORTWAVE ENERGY WILL DROP SOUTH
OVER THE CWFA TODAY. THE FRONT IS STILL HARD TO FIND IN SURFACE
FEATURES...BUT IS MORE NOTABLE WITH AN 850MB WIND FIELD. FOG OVER
THE SHENANDOAH VALLEY THIS MORNING DISSIPATING...WITH KSHD UP TO 4
MILES. DECENT CLOUD FIELD TO THE NORTH WILL GRADUALLY BREAK
THROUGH THE DAY TODAY. HIGH PRESSURE WILL BUILD IN FROM THE NORTH
THIS AFTERNOON. GRID CHANGES TO REFLECT CURRENT TRENDS PROBABLY
WILL NOT BE NOTICED IN THE FORECAST WORDING. UPDATES MAINLY TO
REMOVE MORNING WORDING WILL BE OUT SHORTLY.
THANKS TO PHI FOR SHORT FUSED BACKUP THIS MORNING!
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
SHORTWAVE TROUGH WILL CONTINUE TO PASS THROUGH THE CWFA...AS HIGH
PRESSURE BUILDS IN AT THE SURFACE. THE GRADIENT IS EXPECTED TO
TIGHTEN A BIT TONIGHT...BUT WILL MOSTLY BE FELT OVER MARINE AREAS.
CLOUDS WILL DECREASE...WITH SOME SCATTERED CIRRUS POSSIBLE.
MAIN FORECAST PROBLEM FOR THE SHORT TERM WILL BE THE POSSIBILITY OF
PATCHY FROST ALONG THE MASON-DIXON LINE OVERNIGHT. MODEL TEMPS SEEM
TOO HIGH FOR THE OVERNIGHT HOURS...ESPECIALLY FOR THE NORTHERN TIER
OF ZONES. HAVE ADJUSTED TEMPS DOWNWARD IN THAT AREA. WITH CLEARING
SKIES AND A WEAKENING GRADIENT...SOME PATCHY FROST IS POSSIBLE ALONG
THE MASON-DIXON LINE. HOWEVER THE NAM DOES KEEP THE GRADIENT UP
AROUND 5 KT OVERNIGHT. WILL ADD PATCHY FROST TO THE NORTHERN
MARYLAND ZONES. HOWEVER...IF WINDS GO COMPLETELY CALM...WITH THE
CLEAR SKIES...A FROST ADVISORY MAY HAVE TO BE ISSUED FOR NORTHERN
MARYLAND.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
COOL CANADIAN HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE REGION
TUESDAY BRINGING DRY CONDITIONS ALONG WITH BELOW NORMAL TEMPS. MAX
TEMPS WILL RANGE FROM NEAR 60 IN THE HIGHEST ELEVATIONS OF THE
POTOMAC HIGHLANDS AND BLUE RIDGE MOUNTAINS...TO THE MID 60S IN THE
WASHINGTON AND BALTIMORE METROPOLITAN AREAS...TO THE UPPER 60S
ACROSS CENTRAL VIRGINIA. SURFACE HIGH WILL REMAIN OVERHEAD TUESDAY
NIGHT BRINGING MORE DRY CONDITIONS ALONG WITH SEASONABLY COOL
TEMPERATURES.
SURFACE HIGH WILL MOVE OFF THE COAST WEDNESDAY ALLOWING A RETURN
FLOW TO SET UP. AT THE SAME TIME...HIGH PRESSURE ALOFT WILL ALSO
PUSH OFF TO THE EAST ALLOWING THE NEXT STORM SYSTEM TO APPROACH FROM
THE WEST. MORE HIGH AND MID-LEVEL CLOUDS ARE EXPECTED WEDNESDAY
AHEAD OF THIS SYSTEM...BUT IT SHOULD REMAIN DRY. MAX TEMPS WILL BE A
FEW DEGREES WARMER THAN TUESDAY THANKS TO THE RETURN FLOW. THE STORM
SYSTEM WILL LIKELY DEVELOP INTO A CUT OFF UPPER-LEVEL LOW WEDNESDAY
NIGHT JUST TO OUR SOUTHWEST BEFORE SLOWLY PASSING THROUGH THE REGION
LATE IN THE WEEK. EXACT TIMING OF THIS SYSTEM REMAINS
UNCERTAIN...BUT IT APPEARS THAT THE BEST CHANCE FOR PRECIPITATION
WILL BE TOWARDS THE END OF THE WEEK POSSIBLY INTO THE WEEKEND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
CIGS/VSBYS WILL REMAIN VFR TODAY AND TONIGHT.
VFR CONDITIONS EXPECTED TUESDAY AND WEDNESDAY WITH HIGH/MID CLOUDS
INCREASING DURING THE DAY WEDNESDAY. NEXT STORM SYSTEM WILL BRING A
CHANCE FOR PRECIPITATION LATE IN THE WEEK POSSIBLY INTO THE
WEEKEND WHICH COULD LOWER CIGS/VSBYS BELOW VFR LEVELS.
&&
.MARINE...
A WEAK BOUNDARY WILL CROSS THE WATERS TODAY. THE GRADIENT WILL BEGIN
TO TIGHTEN LATER THIS AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS
IN FROM THE NORTH. HAVE EXTENDED THE SMALL CRAFT ADVISORY HEADLINE
BACK A FEW HOURS TO COVER THE LATE AFTERNOON/EARLY EVENING HOURS.
BUFKIT SOUNDINGS AND LOCAL WRF SHOW THE POSSIBILITY OF 20 KT GUSTS
BEGINNING DURING THE LATE AFTERNOON.
WINDS ACROSS THE LOWER POTOMAC AND CHESAPEAKE BAY NEAR SMITH POINT
WILL BE CLOSE TO SCA CRITERIA TUESDAY MORNING...BUT THE GRADIENT
SHOULD SLACKEN LATER TUESDAY AS HIGH PRESSURE BUILDS OVER THE
WATERS. HIGH PRESSURE WILL REMAIN IN CONTROL TUESDAY NIGHT BEFORE
DRIFTING OFF THE COAST WEDNESDAY.
A RETURN FLOW WILL ALLOW FOR WINDS TO APPROACH SCA CRITERIA DURING
THE MIDDLE PART OF THE WEEK. THE NEXT STORM SYSTEM WILL APPROACH THE
WATERS LATE IN THE WEEK AND POSSIBLY INTO THE WEEKEND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 AM EDT
TUESDAY FOR ANZ530>537.
&&
$$
UPDATE...SAR
PREVIOUS DISCUSSION...LISTEMAA/LASORSA
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