-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 141102
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
702 AM EDT TUE MAY 14 2013

.SYNOPSIS...
CANADIAN HIGH PRESSURE WILL BUILD INTO THE REGION TODAY BRINGING
UNSEASONABLY COOL TEMPERATURES...BEFORE SLIDING OFF THE COAST THIS
EVENING. MUCH WARMER TEMPERATURES WILL RETURN WEDNESDAY AND
PERSIST INTO THE UPCOMING WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
FROST ADVSRY HAS BEEN ALLOWED TO EXPIRE AS TEMPS ARE ALREADY
STARTING TO RISE THIS MRNG. LO TEMPS MISSED RECORDS BY 1-2 DEGREES
AT RIC/ORF/ECG. DRY CONDS TDY AS ~1023 MB SFC HI PRES BLDS JUST
SOUTH OF THE AREA. THIS WILL LEAD TO LGT WESTERLY FLOW AND TEMPS
ABOUT FIVE TO 10 DEGREES BLO NORMAL...HIGHS GENRLY IN THE MID 60S
TO NEAR 70. OTW FOR TDY...CLDS SHOULD BEGIN TO INCREASE DURING THE
AFTN AS MID-LVL RIDGING ENCROACHES FROM THE WEST.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE HIGH DRIFTS OFFSHORE THIS EVENG. SIGNIFICANT WAA IS EXPECTED
TONIGHT AS THE MID-LEVEL RIDGE QUICKLY BUILDS IN. THERE IS A
DECENT AMOUNT OF MOISTURE WITHIN THE 800-500MB LAYER RESULTING IN
CONSIDERABLE CLOUD COVER. INCLUDED 20-30% POPS OVER NE AREAS IN
ASSOCIATION WITH THE ENHANCED WAA AND INCREASE IN MOISTURE. LOWS
WILL BE MUCH MILDER RANGING FROM THE UPPER 40S TO LOWER 50S.

WAA SHIFTS BELOW 800MB WEDNESDAY RESULTING IN MUCH WARMER
TEMPERATURES. ADDITIONALLY...SURFACE DEWPOINTS RISE WITH SW LOW-
LEVEL FLOW. 850MB TEMPERATURES RISE TO ~16-18C BY LATE AFTERNOON
AND THIS SHOULD HELP TEMPERATURES RANGE FROM THE UPPER 60S/LWR 70S
ALONG THE IMMEDIATE COAST...TO UPPER 70S/LWR 80S IMMEDIATELY
INLAND...TO THE MID TO UPPER 80S ALONG/W OF I-95. THE ONLY CAVEAT
TO THE WARMING TREND COULD BE IF CLOUD COVER DOES NOT BREAK
(POSSIBLE IF A BOUNDARY WERE TO DEVELOP).

LATE WEDNESDAY/WEDNESDAY NIGHT...A BELT OF 850-700MB LAPSE RATES
>7.5C/KM PASSES OVER THE REGION. MLCAPE VALUES ARE AROUND
1200-1600 J/KG (GFS) AND 1600-2000 (NAM) ALONG WITH A SURFACE WARM
MOIST THETA-E AXIS. GIVEN THIS...THERE WILL BE A CHANCE OF
THUNDERSTORMS ESPECIALLY OVER THE NE DURING THE EVENING. MUCH OF
THIS WILL ULTIMATELY BE DICTATED BY UPSTREAM ACTIVITY IN WNW FLOW.

A SIMILAR SCENARIO SETS UP THURSDAY. HOWEVER...CHANCES FOR RAIN MAY
BE A LITTLE HIGHER AS A THETA-E BOUNDARY DROPS DOWN FROM THE N.
HIGHS SHOULD BE IN THE MID 80S...WITH LOCALLY COOLER READINGS
ALONG THE IMMEDIATE ATLANTIC COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE AND UPPER LEVEL RIDGING DOMINATE THE WEATHER
PATTERN...WHICH WILL PUMP AN INCREASINGLY WARMER AIRMASS INTO THE
MID ATLANTIC REGION THU NIGHT THROUGH THE WEEKEND AND INTO EARLY
NEXT WEEK. A FRONT WILL MOVE OFF THE CAROLINA COAST THU NIGHT AND
PRECIP WILL COME TO AN END FROM NW TO SE. SFC HIGH PRESSURE RETURNS
FRI AND SLIDES JUST OFF THE EAST COAST FRI NIGHT...BECOMING
RELATIVELY STATIONARY INTO EARLY NEXT WEEK. MEANWHILE...UPPER LEVEL
RIDGING OVER THE CTRL U.S. THU NIGHT IS EXPECTED TO SHIFT OVER THE
MIDWEST ON SAT...THEN MOVE OVER THE MID ATLANTIC REGION ON SUN. THE
RIDGE AXIS PASSES OVER THE AREA EARLY MON AND MOVES JUST OFF THE
COAST BY MON EVENING. IF THIS INDEED HAPPENS...MON COULD BE THE
HOTTEST DAY IN THIS STRETCH OF WARMER TEMPERATURES. THE
CAVEAT TO THIS IS THAT UPPER TROUGHS HAVE A TENDENCY TO SLOW THEIR
EWD PROGRESSION AS THEY DIG SWD AND THE UPPER RIDGE AMPLIFIES. IF
THIS HAPPENS...THEN THE PASSAGE OF THE RIDGE AXIS AND THE SUBSEQUENT
WARMEST TEMPERATURES COULD BE DELAYED UNTIL TUE. MAX TEMPERATURES
SHOULD EXPERIENCE A BRIEF COOL DOWN INTO THE LOWER-MID 80S FRI
BEHIND THE EXITING BOUNDARY...THEN WARM AGAIN (POTENTIALLY INTO THE
UPPER 80S) BY THE END OF THE WEEKEND. VARIOUS MODEL SOLUTIONS HAVE
DIFFERENT TIMING REGARDING SHORTWAVE FEATURES AND SUBSEQUENT
RAINFALL (MORE ON THIS IN THE NEXT PARAGRAPH)...SO WILL BE
CONSERVATIVE WITH THE WARM-UP FOR NOW. LOW TEMPS WILL GENERALLY BE
IN THE UPPER 50S TO MID 60S. DEWPOINTS WILL ALSO BE RISING INTO THE
60-65 DEGREE RANGE AND WILL CREATE SOMEWHAT HUMID CONDITIONS
THROUGHOUT THE EXTENDED PERIODS.

IN ADDITION TO VARIOUS TIMING OF SHORTWAVE FEATURES/PRECIP AMONG
LONG RANGE MODELS...THE WEATHER PREDICTION CENTER (WPC...FORMERLY HPC)
INDICATES THAT A PERSISTENT/STATIONARY FRONTAL BOUNDARY WILL BE
DRAPED W TO E FROM THE OHIO VALLEY TO/ALONG THE MASON-DIXON LINE THU
NIGHT INTO EARLY NEXT WEEK. THE COMBINATION OF THIS BOUNDARY WITH
THE AFOREMENTIONED SHORTWAVES WILL MAKE AFTN/EVENING SHOWERS AND
STORMS POSSIBLE EACH DAY.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
VFR CNDTNS XPCTD THRU FCST PRD. HIGH PRS BUILDS OVR RGN TDY.
TSCTNS SHOW SOME HIGH LVL MSTR AT TIMES (ABV 15K FT).

VFR CNDTNS XPCTD WED / THURS. SCT DIURNAL TSTMS PSBL THURS THRU SAT.
-- End Changed Discussion --

&&

.MARINE...
HAVE CANCELLED SCA HEADLINES AS CRNT OBS HAVE DROPPED BLO SCA LEVELS.
HIGH PRS OVR THE AREA TDY RESULTS IN A N WND AOB 15 KTS BCMG LGHT
AND VRBL BY LATE AFTRN/EVEN...THEN SRLY TONITE DUE TO RETURN FLOW AS
HIGH PRS MOVES OFFSHORE. GRDNT BEGINS TO TIGHTEN AFTR MIDNITE WITH
SPEEDS INCRG TO BTWN 10-15 KTS. SEAS AVGG 2-3 FT THRU TONITE.

PRS GRDNT TIGHTENS A BIT MORE WED AS WRM FRNT LIFTS NW OF RGN. QSTN
IS WHETHER SCA CNDTNS ARE REACHED AS IT APPEARS THAT WINDS WILL BE
GUSTIER OVER LAND THAN WATER. CONFIDENCE NOT HIGH ENUF ATTM TO GO
WITH A SCA HEADLINE...SO WILL GO WITH A SOLID 15 KTS FOR NOW. BOTH
WNA/SWAN INCRS SEAS TO ARND 5 FT OUT NR 20 NM BY LATE WED ACROSS THE
NRN CSTL WTRS. ELECTED TO HOLD OFF ON ANY HEADLINES AS THIS WUD BE A
MARGINAL LATE THIRD & FOURTH PRD EVENT.

FRNTL BNDRY PROGGED TO STALL IVOF MID ALTNTC RGN BY LATE IN THE WEEK.
THIS XPCTD TO KEEP WNDS RTHR VRBL IN DRCTN WITH SPEEDS AOB 15 KTS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
-- End Changed Discussion --

&&

$$
SYNOPSIS...AJZ/MAS
NEAR TERM...MAS
SHORT TERM...AJZ/MAS
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR