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Area Forecast Discussion
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000
FXUS61 KAKQ 210334
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1034 PM EST THU NOV 20 2014

.SYNOPSIS...
A DRY COLD FRONT PUSHES OFFSHORE OVERNIGHT. HIGH PRESSURE CENTERS
OVER THE REGION FRIDAY AND FRIDAY NIGHT....PUSHING OFFSHORE LATE
SATURDAY. A WARM FRONT LIFTS OVER THE REGION SUNDAY BEFORE A
TRAILING COLD FRONT CROSSES THE REGION EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
SFC COLD FRONT WILL CONTINUE TO DROP SOUTH THROUGH THE REGION
OVERNIGHT...BEFORE EXITING THE AREA AROUND DAYBREAK. DUE TO THE
SLOW MOVEMENT OF THE FRONT...TEMPS HAVE ACTUALLY REMAINED STEADY OR
RISEN THIS EVENING. THIS WILL CONTINUE TO BE THE CASE UNTIL EARLY
FRI MORNING WHEN THE WINDS FINALLY TURN N-NW AND THE COLDER AIR TO
THE NW IS ABLE TO SPILL INTO THE AREA. NO CLOUDS OR PCPN TO SPEAK
OF WITH THE FRONT. LOWS TONIGHT IN THE LOW/MID 20S PIEDMONT TO
THE MID/UPR 30S AT THE COAST. 

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
PERSISTENT CYCLONIC FLOW OVER THE ERN CONUS FINALLY EJECTS EWD
OFF THE NE COAST AS A STRONG 150+ KT UPPER JET EXITS THE MID-
ATLANTIC COAST. STRONG ~1035MB SFC HIGH PRESSURE BUILDS OVER THE
OH VALLEY EARLY FRI BEFORE CENTERING OVER THE LOCAL AREA LATE FRI-
FRI NIGHT. CAA WANES FRI AFTERNOON...BUT H85 TEMPS WILL HAVE
REACHED -8 TO -10C (-1 TO -2 STD DEV). THE RESULT WILL BE WELL
BELOW NORMAL DAYTIME TEMPS...GENERALLY IN THE MID 30S IN THE NW TO
MID 40S SE (-2 STD DEV OR NEARLY 20 DEGS BELOW NORMAL). SOME
RECORD LO MAX READINGS MAY BE IN DANGER. NW WINDS WILL GUST UP TO
20-25 MPH DURING THE AFTERNOON BEFORE THE PRESSURE GRADIENT
RELAXES LATE. SFC HIGH CENTERS OVER THE REGION FRI NIGHT. CALM-
LIGHT WINDS AND CLEAR SKIES WILL ALLOW TEMPS TO DROP BACK INTO THE
MID-UPPER TEENS TO LOWER 20S INLAND. UPPER 20S- LOW 30S NEAR THE
COAST. RETURN FLOW ON THE BACK SIDE OF DEPARTING UPPER/SFC HIGH
PRESSURE SAT AFTERNOON WILL RESULT IN MODERATING TEMPS AND
INCREASING THICKNESSES. H85 TEMPS ALSO RECOVER QUICKLY FRI NIGHT-
SAT...WARMING TO AROUND +6C BY LATE SAT. HIGHS WILL BE SLOW TO
RECOVER...WARMING ONLY INTO THE UPPER 40S NW TO LOW 50S SE (STILL
10 DEGS BELOW NORMAL). 

MEANWHILE...SRN STREAM SHORTWAVE AND ASSOCIATED SFC LOW MOVE INTO
THE SRN PLAINS SAT AS ZONAL FLOW DEVELOPS OVER THE LOCAL AREA. H85
HIGH PUSHES OFFSHORE LATE SAT WITH FLOW ON THE WRN PERIPHERY
TAPPING INTO GULF MOISTURE. MID- UPPER CLOUDS WILL INCREASE LATE
SUN INTO SUN NIGHT FROM THE WEST AS MOISTURE ADVECTION
STRENGTHENS. WARM FRONT LIFTS INTO THE TN/KY VALLEYS LATE SAT
NIGHT...EXTENDING INTO THE SE STATES. SHORTWAVE EJECTS NEWD FROM
THE SRN PLAINS LATE SAT NIGHT INTO SUN MORNING...LIFTING OVER THE
CNTRL APPALACHIANS SUN. MODELS COMING INTO BETTER AGREEMENT WITH
TIMING OF THE PRECIP...BUT AS IS TYPICAL WITH OVERRUNNING EVENTS
AND THE PRESENCE OF AN UPSTREAM 120+ KT UPPER JET...WILL KEEP POPS
EARLY SUN ACROSS THE PIEDMONT INTO CNTRL VA. MAIN BRUNT OF
DYNAMICS/MOISTURE/PRECIP QUICKLY SPREADS ACROSS THE REGION SUN
AFTERNOON-EVENING. DIFFLUENCE/DIVERGENCE ALOFT AND THE LIFTING
SHORTWAVE WILL PROVIDE DYNAMIC FORCING FOR ASCENT OVER THE REGION.
OVERRUNNING COMMENCES AS THE WARM FRONT LIFTS INTO THE REGION SUN
AFTERNOON. PER GEFS STD ANOMALIES...H85 MOISTURE FLUX IS PROGGED
AT +3 TO +4 STD DEV WITH PWATS INCREASING TO AROUND 1.4 INCHES.
SOUNDINGS ALSO DEPICT A DEEPLY SATURATED COLUMN. AS A
RESULT...LOCALLY HEAVY RAINFALL IS POSSIBLE. HAVE RETAINED
CATEGORICAL POPS SUN AFTERNOON AND SUN EVENING AS THE WARM FRONT
LIFTS THRU THE REGION. BRUNT OF PRECIP WILL LIKELY PUSH OFFSHORE
SUN NIGHT AS A DRY SLOT PUNCHES INTO THE REGION. TEMPS SUN WILL
WARM INTO THE UPPER 50S NW TO MID 60S SE. LITTLE DIURNAL TREND
EXPECTED SUN NIGHT AS TEMPS ONLY FALL A FEW DEGS INTO THE LOW 50S
NW TO UPPER 50S SE.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS DIFFER WRT TIMING OF THE CDFRNTL PASSAGE ACROSS THE AREA. 
GFS ABT 6 HRS FASTER THAN EURO MON NIGHT. EITHER WAY...MONDAY 
APPEARS TO BE A WARM AND BREEZY DAY AS FA BECOMES WARM SECTORED 
WELL AHEAD OF CDFRNT. KEPT LOW CHC POP GOING FOR ANY SHWR THAT 
DVLPS IN THE WRMR AIRMASS. HIGHS U60S-M70S. CHC POPS MON NIGHT 
WITH FROPA. LOWS M-U40S...XCPT 50-55 SERN CSTL AREAS.  

KEPT LOW CHC POPS ACROSS ERN AREAS TUE AS A WEAK S/W MOVES NE ALONG 
THE FRNT AS IT SLOWLY MOVES OFF THE COAST. OTW...DRIER AND COOLER
AIR MOVES IN FROM THE WEST. HIGHS U50S-L60S. LOWS TUE NITE M30S-M40S.

HIGHS PRES FROM THE WEST (PACIFIC ORIGIN VS CANADIAN) ALLOWS FOR A
QUIET MID WEEK PRD. DRY WX THRU TURKEY DAY ALONG WITH A GRDL COOLING 
TREND. HIGHS WED 50-55. LOWS WED NITE U20S-U30S. HIGHS THURSDAY 
U40S-L50S.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
AS OF 23Z...A POORLY DEFINED COLD FRONT OVER THE MID ATLANTIC STATES 
WILL EVENTUALLY MAKE IT OFF THE COAST OVERNIGHT. HAVE WINDS SHIFTING 
TO NW AT THE TAF SITES BETWEEN 03 AND 07Z. THE SKY WILL REMAIN CLEAR 
DURING THE NEXT 24 HOURS. NW WINDS BECOME GUSTY (15-20 KTS) FRIDAY 
AFTERNOON. 

OUTLOOK...HIGH PRESSURE SETTLES OVER THE MID-ATLANTIC REGION FRI AND 
SAT...MOVING WELL OFFSHORE LATE SATURDAY. A COMPLEX WEATHER SYSTEM IS 
EXPECTED TO BRING PERIODS OF RAIN SUNDAY THROUGH MONDAY WITH IFR 
CONDITIONS POSSIBLE.

&&

.MARINE...
10 PM UPDATE...SCA EXTENDED SET UP FOR ALL THE RIVER ZONES AND ARE 
NOW IN EFFECT THROUGH 15Z FOR ALL OF THE COASTAL ZONES. AS COLD 
FRONT MOVES ACROSS THE WATERS...NW WINDS INCREASE AFTER MIDNIGHT 
WITH MODELS INDICATING THE HIGHEST VELOCITIES LIKELY OCCURRING 
AROUND 12Z OR AFTER. SOME OF THE HEADLINES MAY NEED TO BE FURTHER 
EXTENDED. 

PREVIOUS DISCUSSION FROM THURSDAY AFTERNOON...
THE GUSTY SW WINDS AHEAD OF THE FRNT WILL DMNSH A BIT THIS EVENING 
BEFORE BCMG W-NW AFTR MIDNITE AS STRNG CAA SETS IN POST FROPA. 
LATEST DATA SUGGESTS THE SURGE (15-20 KTS) LASTS TILL ARND 18Z FRI 
ACROSS THE BAY AND SND SO HAVE XNNDD THE SCA HEADLINES ACROSS THOSE 
AREAS SVRL MORE HRS. CSTL WTRS A BIT DIFFERENT AS WNDS ARND 25 KTS 
SHUD DMNSH AFTR 12Z. SEAS HAVING TROUBLE REACHING 5 FT ACROSS SRN 
CSTL WTRS AND MAY ONLY REACH THOSE VALUES OUT NR 20 NM. THUS...WILL 
LET THE SCA ON CSTL WTRS EXPIRE LATE TONITE/ERLY FRI THERE. 

HIGH PRESSURE SETTLES OVER THE MID ATLANTIC REGION FRI NIGHT THRU
SAT NIGHT THEN MOVES WELL OFFSHORE SUNDAY RESULTING IN WINDS AND
SEAS BLO SCA LVLS. NEXT CHC FOR SCA'S WILL COME LATE SUN INTO MON AS 
SRLY WINDS INCRS AHEAD OF NEXT SYSTEM APPROACHING FROM THE SW.    
 
TONIGHTS TIDES PROGGED ABOUT A HALF TO THREE QUARTERS OF A FOOT 
BELOW NORMAL. TIDES EXPECTED TO SLOWLY RETURN TO NEAR NORMAL OVER 
THE NEXT FEW DAYS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR ANZ635>638-650-
     652-654-656-658.
     SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR ANZ630>634.

&&

$$
SYNOPSIS...JDM/SAM
NEAR TERM...JDM
SHORT TERM...SAM
LONG TERM...MPR
AVIATION...LSA
MARINE...MPR/LSA






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