Relay, Maryland Forecast Discussion

000
FXUS61 KLWX 060307
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1007 PM EST MON JAN 5 2009

.SYNOPSIS...
A STRENGTHENING STORM SYSTEM WILL TRACK ACROSS THE REGION TUESDAY
AND WEDNESDAY. THAT STORM WILL BRING ANOTHER ROUND OF MIXED
PRECIPITATION...MAINLY FROM TUE MORN THRU WED MORN.

AS THE STORM EXITS...COLD AIR WILL BE PULLED IN BEHIND IT FOR THU
AND FRIDAY. A WARM FRONT WILL LIFT NORTH OF THE REGION FRIDAY
NIGHT...FOLLOWED QUICKLY BY ANOTHER STRONG COLD FRONT SATURDAY. COLD
AIR WILL LAST INTO NEXT WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
HIGH PRESSURE RIDGE AXIS HAS SETTLED ACROSS THE NORTHERN CWFA. A
WARM FRONT REMAINS ALONG THE VA/MD BORDER. TEMPERATURES ARE
APPROACHING FREEZING ALONG THE MD/PA BORDER AND ALONG THE HIGHER
ELEVATIONS ALONG THE BLUE RIDGE. ONE THING TO NOTE...ACTUAL
DEWPOINTS ARE SEVERAL DEGREES LOWER THAN WHAT THE MODELS WERE
PROGGING. THE COLD AIR WILL CONTINUE TO SETTLE SOUTHWARD OVERNIGHT.

A WINTRY MIX IS STILL EXPECTED ACROSS MUCH OF THE CWFA. EARLIER THIS
EVENING...WENT AHEAD AND EXPANDED THE ADVISORY FURTHER SOUTH INTO
THE SHENANDOAH VALLEY AND INTO NELSON AND ALBEMARLE COUNTIES. EVEN
THOUGH TEMPERATURES WERE RATHER WARM IN THIS REGION TODAY...THE COLD
AIR SHOULD MAKE IT INTO THE ELEVATIONS ABOVE 1 KFT. THE LOWER
ELEVATIONS MAY STAY RIGHT ABOVE FREEZING...AND MAY ONLY GET SOME
RAIN MIXED WITH SOME SLEET.

IN THE FAR NW...UPGRADED THE ADVISORY TO A WINTER STORM WARNING FOR
ALLEGANY AND MINERAL COUNTIES. MODELS HAVE BEEN CONTINUALLY SHOWING
GOOD QFP IN THIS REGION. IN ADDITION...THE COLDEST AIR TENDS TO BE
HARDEST TO SCOUR OUT IN THIS AREA. A QUARTER INCH OF ICE IS NOT OUT
OF THE QUESTION.

ELSEWHERE...THE WINTER WEATHER ADVISORY LOOKS GOOD. ONSET OF
PRECIPITATION STILL LOOKS GOOD.


&&

.SHORT TERM /TUESDAY NIGHT THROUGH 6 PM TUESDAY/...
I WROTE IN MY MRNG DSCN ABT CONCERN REGARDING THE POSN OF THE SFC
HIGH ATTM IF ONE IS LOOKING FOR A PROLONGUED PD OF COLD DRY AIR
TO FILTER INTO THE MID ATLC FOR A FZRA EVENT. HIGH IS CURRENTLY
OVER INDIANA AND PROGGED TO TRACK ACROSS NEW JERSEY - NOT A NRML
SOURCE RGN FOR SUBFREEZING AIR.

MDLS ARE IN REASONABLE AGREEMENT THAT IF ANYWHERE IN THE CWA IS
UNDER THE GUN IT`S THE NWRN CORNER...WHERE SUB 1300 DM THCKNS IS
XPCTD TO LAST THRUT THE DAY. I DON`T FEEL COMFORTABLE ENOUGH ABT
ICE ACCRETION AMTS TO GO W/ A FZRA WRNG...BUT HV IMPEMENTED AN
ADVSRY W OF THE MAJOR CITIES XTNDG TO THE PA/WV BORDERS. IF LATER
MDLS COME IN COLDER THERE IS STILL TIME TO UP THIS TO A WRNG.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
MIXED PRECIP WILL CONT TO PHASE OVER TO A COLD RAIN FROM SE TO NW
TUE NIGHT. AS USUAL AREAS AROUND HGR AND CBE SHOULD BE THE LAST TO
PHASE OVER TO REGULAR RAIN...PROB NOT UNTIL WED MORN. THOSE AREAS
WILL HAVE THE WORST POTENTIAL FOR AN ICING THREAT. AT THE MOMENT
WILL HAVE A WINTER WEATHER ADVISORY FOR THOSE AREAS... BUT MAY NEED
TO BE UPGRADED TO A WINTER STORM WARNING IF CONDITIONS PROCEED
TOWARDS THE MORE WORST CASE SCENARIO. RIGHT NOW...EXPECT LESS THAN A
QUARTER INCH OF ICE...EVEN IN THE NW COUNTIES.

AS THE LOW PASSES THRU AND WRAPS UP TO OUR NE...WINDS WILL PICK UP
AND THE COLD AIR WILL SURGE IN WITH 850MB TMPS FALLING INTO THE
NEGATIVE TEENS BY LATE THU.

NEXT UP IS A COLD FRONT SATURDAY WITH THE CHANCE FOR RAIN OR SNOW
SHOWERS...BUT NOT THAT MUCH TOTAL PRECIP WITH THE FRONT. ANOTHER
SURGE OF COLD AIR FOLLOWS WITH 850MB TEMPS DROPPING EVEN LOWER TO
AROUND MINUS 20C BY SUNDAY.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
CIGS MOST AREAS ARE CURRENTLY VFR. EXPECT CIGS/VSBYS TO DROP TO
MVFR/IFR EARLY TOMORROW MORNING AS WINTRY PRECIPITATION OVERSPREADS
THE AREA.

IFR CONDITIONS ARE EXPECTED TUE NIGHT INTO WED BEFORE BREAKING UP
AFTER THE COLD FRONT MOVES THROUGH. GUSTY SFC WINDS G30KT POSSIBLE
WED AFTERNOON THRU FRI MORN...AND AGAIN LATE SAT INTO SUN.

&&

.MARINE...
WINDS BLO SCA VALUES TNGT AND TUE.

SMALL CRAFT WINDS ARE EXPECTED TO DEVELOP LATE WEDNESDAY AND PERSIST
INTO THU NIGHT. SMALL CRAFT WILL RETURN FRI NIGHT THRU SUNDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO 9 AM EST
     WEDNESDAY FOR MDZ003>007-009-010.
     WINTER STORM WARNING FROM 6 AM TUESDAY TO 9 AM EST WEDNESDAY
     FOR MDZ501-502.
VA...WINTER WEATHER ADVISORY UNTIL 11 PM EST TUESDAY FOR VAZ021-025-
     026-036>038.
     WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO 9 AM EST
     WEDNESDAY FOR VAZ027>031-039>042-051>053.
WV...WINTER WEATHER ADVISORY UNTIL 11 PM EST TUESDAY FOR WVZ054.
     WINTER WEATHER ADVISORY FROM 6 AM TUESDAY TO 9 AM EST
     WEDNESDAY FOR WVZ050>053-055-501-502.
     WINTER STORM WARNING FROM 6 AM TUESDAY TO 9 AM EST WEDNESDAY
     FOR WVZ503-504.
MARINE...NONE.

&&

$$
UPDATE...LISTEMAA

NWS LWX Office Area Forecast Discussion

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