Area Forecast Discussion
Issued by NWS Sterling, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 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 42 43 44 45 46 47 48 49 50
000
FXUS61 KLWX 290900 CCA
AFDLWX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
359 AM EST MON DEC 29 2014

.SYNOPSIS...

WEAK DISTURBANCES WILL RIDE ALONG A COLD FRONT...MAINLY TO OUR
SOUTH...TODAY THROUGH TUESDAY. HIGH PRESSURE WILL BUILD INTO THE EASTERN
HALF OF THE COUNTRY FOR THE SECOND HALF OF THE WEEK. LOW PRESSURE
IS EXPECTED TO AFFECT THE MID ATLANTIC REGION THIS WEEKEND.

&&

.NEAR TERM /TODAY AND TONIGHT/...

AS OF 08Z...1055MB SFC HIGH IS NORTH OF CALGARY WHILE AN UPR LOW IS
OVER NRN QUEBEC AND AN UPR TROUGH IS OVER THE INTERMOUNTAIN WEST. A
WEAK COLD FRONT EXTENDS FROM A LOW EAST OF NEWFOUNDLAND TO THE
CAROLINAS. HIGH PRESSURE WILL BUILD NORTH OF THE CWA TODAY...WITH A
NELY FLOW OF 10 MPH OR SO SETTING UP. RAIN CURRENTLY ALONG SOUTHERN
PERIPHERY OF CWA (WITH PATCHY SPRINKLES/LIGHT RAIN UP THROUGH THE DC
METRO AREA) WILL CONTINUE TO DRIFT SOUTH THROUGH TODAY. REDUCED POPS
ACROSS THE BALT-WASH METRO PER RECENT HRRR RUNS AND OBSERVED RADAR
TRENDS. RAIN WILL CONTINUE TO BE LIGHT WITH LESS THAN A TENTH INCH
QPF. MAX TEMPS LOW TO MID 40S UNDER PERSISTENT MID-LEVEL CLOUDS.

ELY COMPONENT WILL PROMOTE PRECIP DEVELOPMENT FOR CNTRL VA BLUE
RIDGE AND AREAS FARTHER WEST. COLDER AIR THERE WILL ALLOW SOME SNOW
ABOVE ABOUT 2500 FT TODAY...LOWERING TO AROUND 1000 FT TONIGHT.
EXPANDED SNOWFALL AREAS TO INCLUDE DUSTING/0.1 INCH IN THE CNTRL
SHEN VLY...STILL LESS THAN INCH FOR RIDGES. ELSEWHERE DRY AND
CLOUDY...MIN TEMPS UPR 20S TO LOW 30S (MID 30S FOR NEAR SHORE).

&&

.SHORT TERM /TUESDAY/...

PRECIP SHIFTS SOUTH AS 1030MB SFC PRES SHIFTS INTO THE
CWA. LIGHT NLY FLOW AND MAX TEMPS UPR 30S TO LOW 40S UNDER CLEARING
SKIES.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...

HIGH PRES XPCTD TO BUILD INTO THE AREA FOR NEW YRS EVE...SO WX WL
NOT BE A PROBLEM WED NGT OR THE 1ST DAY OF 2015. THE HIGH SHOULD
RMN IN CONTROL OF MID ATLC WX THRU THE END OF THE WK. THIS WL
ALLOW TEMPS TO MODERATE - THU MRNG LOWS WL MAINLY BE IN THE
L20S...BY SAT MRNG ABT TEN DEGS WARMER. THE SAME WL BE TRUE W/
HIGH TEMPS - THU ARND 40...A50 SAT.

LOW PRES WL BE INFLUENCING THE ERN U.S. OVR THE WKND. THERE IS
DIFFERENCE IN THE MDLS AS TO THE TRJECTORY OF THE SYSTEM - EURO
HAS IT ON A SRN TRACK WHILE THE GFS TAKES IT INTO THE ERN GRT LKS
ALNG W/ A COLD FNT PUSHING ONTO THE E CST. OBVIOUSLY THIS WL NEED
TO RESOLVED IN THE COMING DAYS. AT THIS MOMENT P-TYPE LOOKS TO BE
LIQUID. IF TEMPS ARE ABLE TO DROP BLO FRZG THEN FZRA WL NEED TO BE
CONSIDERED BUT THAT IS A LONG WAY AWAY.

LOOKING AT THE HEMISPHERIC 500 MB PATTERN OF BOTH THE GFS AND
ECM...THE COLDEST AIR LOOKS TO RMN LOCKED OVR HUDSON BAY INTO NEXT
WK. JAN 5-8 2014 SAW XTRMLY COLD AIR IN THE CWA AND THE ISSUANCE OF
MULTIPLE WIND CHILL ADVSRIES AND WRNGS (ACTUAL WIND CHILL OF -11
AT DCA....BLO -40 IN THE HIGHLANDS). NO REPEAT IN 2015.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...

VFR CONDS CONTINUE TO PREVAIL AS COLD FRONT AND ASSOCIATED RAIN
CONTINUES TO MOVE SOUTH.

VFR CONDS XPCTD TUE NGT THRU FRI.

&&

.MARINE...

LIGHT SWLY FLOW VEERS NWLY TODAY AS A COLD FRONT CROSSES THE WATERS
THIS AFTERNOON AND EVENING. COULD BE A NLY SURGE WITH GUSTS AROUND
18 KT LATE TONIGHT. DID NOT RAISE AN SCA DUE TO UNCERTAINTY...BUT
ONE OUT OF SANDY POINT IS POSSIBLE INTO MONDAY.

NO PROBS XPCTD TUE NGT THRU FRI ON THE WATERS.

&&

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

&&

$$
PRODUCTS...BAJ/WOODY!








USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.