000
FXUS61 KAKQ 201751
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1251 PM EST THU NOV 20 2008
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY. HIGH PRESSURE
WILL BUILD DOWN ACROSS THE AREA FROM FRIDAY THROUGH THE WEEKEND.
THIS WILL KEEP TEMPERATURES UNSEASONABLY COLD FRIDAY INTO THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED THE SKY GRIDS BASED ON LATEST OBS AND SATELLITE TRENDS.
OTW...CURRENT FCST REMAINS ON TRACK.
HIGH TEMPS TODAY WILL BE ABOUT 8-10 DEG WARMER THAN WED AS A MAINLY
DRY COLD FRONT CROSSES THE REGION. HIGHS UPR 40S TO MID 50S. MDLS
HV SPED UP TIMING OF THIS FRONT...BUT IT STILL LOOKS LIKE THE
REALLY COLD AIR WILL COME LATER THIS EVENING WITH THE AMPLIFICATION
OF THE UPR TROF.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A RETURN OF THE COLD AIR COMES TONIGHT INTO FRIDAY AS LOWS DROP TO
MID 20S TO AROUND 30 TONIGHT. BEEFED UP CLD COVR OVR SRN COUNTIES
TONIGHT...AS MDL SOUNDINGS...PARTICULARLY THE GFS SHOW A DEEP
SATURATED LAYER AROUND 8000 FT. PROVIDED ENUF LIFT AS DEPICTED BY
THE GFS...THERE IS A CHC THAT FLURRIES MAY DEVELOP...MAINLY AFTER
MIDNIGHT FOR OUR FAR SRN COUNTIES. (INCLUDING MECKLENBURG AND NC.)
HV ADDED MENTION OF THIS TO FORECAST.
BY LATER FRI MORNING...COLUMN PRETTY MUCH DRIES UP...AND WITH IT THE
CHC`S FOR FLURRIES. ATTENTION THEN TURNS TO THE ERN SHORE WITH THE
SLIGHT CHC FOR -SHSN POSSIBLE AS THE STRENGTHENING UPR TROF SHIFTS
EAST. ALSO...CONSIDERING THE VERY COLD AIR RUNNING DOWN OVER THE BAY
FRI AFTN AND THRU THE OVERNIGHT...THE FORMATION OF BAY EFFECT
-SHSN CANNOT BE RULED OUT. HV MAINTAINED THE SLIGHT CHC OF -SHSN
FOR THIS AREA ATTM. FRI NIGHT ON TRACK TO BE THE COLDEST NIGHT OF
THE SEASON THUS FAR WITH LOWS EXPECTED IN THE TEENS TO MID 20S.
SAT/SUN LOOK QUIET AS SFC HIGH PRES BUILDS OVR THE REGION FROM THE
W. HIGHS IN THE 40S BOTH DAYS...WITH LOWS 20-34 SAT NIGHT...AND UPR
20S-30S SUN NIGHT.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS MENTIONED...THE HIGH MOVES OVERHEAD SAT NIGHT. LOW TEMPS WILL
ONLY BE IN THE MID 20S TO LWR 30S (MID 30S AT THE COAST). HIGH
TEMPS REMAIN WELL BLO NORMAL SUN...45 TO 50. THE HIGH WILL THEN
SLIDE OFFSHORE SUNDAY NIGHT INTO EARLY MON AS THE NEXT COLD FRONT
APPROACHES FROM THE NW. TEMPS WILL WARM AHEAD OF THE FRONT UNDER
SW FLOW...WITH HIGHS IN THE LWR 50S TO UPR 50S ON MON.
THE FRONT MOVES THRU LATE MON THRU TUE. GFS KEEPS AN AREA OF LOW
PRES WELL TO OUR N OVER SERN ONTARIO/UPSTATE NY...WHILE THE ECMWF
PROGS A TRACK MUCH FARTHER TO THE S...RIGHT OVER ERN PORTIONS OF
OUR FA. WITH SUCH DISAGREEMENT WENT WITH A BLEND OF THE TWO
SCENARIOS FOR NOW. WILL STICK WITH A CHANCE OF LIQUID PRECIP WITH
FROPA (EXCEPT FAR NW PORTIONS WHERE TEMPS MAY BE COOL ENUF FOR -SN
OR A MIX BRIEFLY MON NIGHT. THE SFC FRONT WILL SLIDE OFFSHORE BY
TUE NIGHT...BUT AN UPR LVL TROF WILL LINGER OVER ERN US THRU WED
AND TEMPS WILL REMAIN COLD...HIGHS MID TO UPR 40S...LOWS UPR 20S
TO UPR 30S RIGHT AT THE COAST.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SATELLITE IMAGERY AND AREA OBSERVATIONS SHOW SCT WAVE CLOUDS
AROUND 6 KFT EXTENDING FROM THE APP RIDGES INTO SE VA AND
DELMARVA WITH WNW FLOW. W/NW SURFACE WINDS HAVE INCREASED WITH
GUSTS GENERALLY UP TO 20 KTS (UP TO 25 KTS ACROSS DELMARVA INCL
SBY)...EXPECT WINDS TO REMAIN UP THROUGH THE AFTERNOON HOURS AS
SFC TROF CROSSES THE AREA.
STRONG SFC HIGH PRESSURE CONTINUES TO SPREAD ACROSS THE EASTERN
HALF OF THE US THIS AFTN AND INTO SUNDAY. THE CENTER OF THE HIGH
WILL REMAIN WEST OF THE MS RIVER THROUGH FRI WHICH WILL KEEP WINDS
OUT OF THE NW AND BRISK AT TIMES FOR THE REST OF THE WORK WEEK. SOME
BAY EFFECT SNOW SHOWERS WILL BE POSSIBLE FRI... THOUGH NO MVFR/IFR
IMPACT EXPECTED TO TAF SITES. VFR WILL CONTINUE THROUGH MONDAY AS
HIGH PRESSURE MOVES OVER THE AREA THIS WEEKEND. THE NEXT COLD
FRONT WILL APPROACH ON MONDAY.
&&
.MARINE...
PRE-FRONTAL NW FLOW HAS INCREASED TO 15-20 KT OVER CHES
BAY...RAISED SCA FLAGS AT 15Z. SCA CONDITIONS (BOTH WINDS AND
WAVES/SEAS) WILL BECOME MORE WIDESPREAD ACROSS THE REGION ON FRI WITH
THE COLD AIR/NW SURGE FOLLOWING THE FRONT. CONFIDENCE THAT GALE
FORCE CONDITIONS WILL BE SEEN BY LATE FRI AFTN OVER THE CSTL
WATERS. HIGH PRES AND MORE TRANQUIL CONDITIONS EXPECTED TO RETURN
SUN INTO EARLY MON.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SATURDAY FOR ANZ630>632.
SMALL CRAFT ADVISORY FROM 10 AM FRIDAY TO 6 PM EST SATURDAY
FOR ANZ633.
SMALL CRAFT ADVISORY FROM 10 AM TO 4 PM EST FRIDAY FOR ANZ650-
652-654-656-658.
GALE WARNING FROM 4 PM FRIDAY TO 1 AM EST SATURDAY FOR ANZ650-
652-654-656-658.
&&
$$
SYNOPSIS...SMF
NEAR TERM...JRL/SMF
SHORT TERM...SMF
LONG TERM...JRL
AVIATION...BKH/BAJ
MARINE...BKH/BAJ
