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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KAKQ 140105
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
905 PM EDT SUN APR 13 2014

.SYNOPSIS...
HIGH PRESSURE REMAINS OFF THE MID ATLANTIC COAST THROUGH MONDAY. A
STRONG COLD FRONT APPROACHES FROM THE WEST MONDAY NIGHT AND CROSSES
THE REGION TUESDAY. CANADIAN HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST TUESDAY NIGHT AND SETTLES OVER THE MID ATLANTIC AND
NORTHEAST WEDNESDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
-- Changed Discussion --
SRLY FLOW ARND OFFSHORE RIDGE RESULTS IN A WARM & DRY APRIL NIGHT
AHEAD. XPCT PERIODIC HIGH CLOUDINESS THRU THE NIGHT. LOWS M-U50S.

PBVS DSCN:
CLOUDS INCREASE MONDAY. PCPN APPROACHES OUR PIEDMONT COUNTIES BY
LATE AFTN. TEMPERATURES WILL BE A LITTLE LOWER THAN THOSE OF SUNDAY
DUE TO CLOUD COVER AND A BIT LOWER HEIGHTS. HIGHS RANGE
70S...RANGING TO NEAR 80 OVER INTERIOR AREAS.
-- End Changed Discussion --

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A SHORT WAVE TROUGH WHICH EXTENDED FROM CENTRAL CANADA INTO THE
NORTHERN ROCKIES SUNDAY WILL MOVE SOUTHEAST AND INTENSIFY THE SYSTEM
IN THE MIDWEST. THIS WILL HELP KICK THE TROUGH TO THE EAST WITH AN
ASSOCIATED STRONG COLD FRONT REACHING THE MID ATLANTIC STATES ON
TUESDAY.

MONDAY NIGHT WILL BE VERY MILD FOR APRIL WITH LOWS IN THE LOW 60S.
HIGHS TUESDAY WILL BE LIMITED BY CLOUDS AND SHRA...BUT STILL RANGE
FROM THE MID/UPPER 60S W...TO THE UPPER 60S/LOW 70S EXCEPT MID 70S
FAR SE.

PRECIPITATION DEVELOPS FROM THE WEST MONDAY NIGHT. THERE WILL BE
CONSIDERABLE DEEP LAYER BULK SHEAR (AROUND 50KT) ALONG WITH STRONG
SYNOPTIC SCALE FORCING. SREF/NAM INDICATES THE LIKELIHOOD OF 2M
DEWPOINTS GREATER THAN 60F DURING MUCH OF TUESDAY AND INTO TUESDAY
EVENING OVER EASTERN AREAS WILL HELP TO BOOST CAPE INTO THE 500 TO
1000 J/KG RANGE. STRONG MOISTURE ADVECTION ASSOCIATED WITH A +3-4 ST
DEV LOW-LEVEL JET. GIVEN THIS...THERE IS SUPPORT FOR A FORCED LINE
OF STRONG CONVECTION AT THE LEADING EDGE OF THE FRONTAL RAIN
BAND...WITH THE POTENTIAL FOR BOWING ECHOES.  MODERATE TO BRIEF
HEAVY RAIN IS EXPECTED. HOWEVER...THE DURATION SHOULD LIMIT STORM
TOTAL QPF AMOUNTS TO AROUND 1.25 INCHES OR LESS.

THE TIMING OF THE FRONT WILL HAVE A BEARING ON WHERE INSTABILITY
SETS UP. AN UNSTABLE AIR MASS IS NOT LIKELY TO DEVELOP UNTIL MIDDAY.
THIS IS MOST LIKELY TO BE EAST OF INTERSTATE 95 BUT THERE IS STILL
UNCERTAINTY AS TO THE LOCATION OF THE FRONT AT A GIVEN TIME. STRONG
WIND GUSTS WILL BE PSBL IN THE AFTERNOON. SPC HAS A SLIGHT RISK OF
SEVERE IN THEIR DAY 3 OUTLOOK OVER FAR SE VIRGINIA AND NE NORTH
CAROLINA ON TUESDAY.

TEMPERATURES WILL COOL QUICKLY BEHIND THE FRONT. THUNDERSTORMS
SHOULD END WITH THE FRONT BUT RAIN LINGERS FOR A FEW HOURS AFTER THE
FRONTAL PASSAGE. TEMPERATURES ARE FORECAST TO DROP DURING THE
AFTERNOON WEST OF INTERSTATE 95...SOME AREAS FALLING TO THE 40S
BEFORE SUNSET.

TEMPERATURES POTENTIALLY DROP TO THEIR LOWEST READINGS SO FAR THIS
MONTH DURING THE MIDDLE OF THIS WEEK. ON WEDNESDAY MORNING...A FEW
READINGS OF AROUND 32 DEGREES WILL BE PSBL OVER THE PIEDMONT...WITH
LOWS IN THE MID 40S NEAR THE COAST. DURATION OF ANY FREEZING
TEMPERATURES SHOULD BE QUITE BRIEF AND WIND SHOULD PREVENT FROST
FROM FORMING. GUIDANCE HAS EVEN COLDER READINGS SO THIS FORECAST
WILL BE ADJUSTED IF NEEDED.

THE FROST FREEZE HAS BEGUN IN ALL BUT THE MD COUNTIES AND AREAS
ROUGHLY NORTH OF US 360. THIS REMAINING SECTION BEGINS APRIL 15
(CORRECTION TO PREVIOUS AFD INFORMATION).

WEDNESDAY WILL BE MOSTLY CLEAR EXCEPT PARTLY CLOUDY AT TIMES TOWARD
THE COAST DUE TO ONSHORE FLOW. HIGH TEMPERATURES WILL BE QUITE
CHILLY... RANGING THROUGH THE LOW TO MID 50S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DRY CONDITIONS TO START OFF THE LONG TERM PERIOD WITH STRONG SFC
HI PRES LOCKED IN PLACE OVR NEW ENGLAND AND RESULTING NE FLOW OVR
THE MID ATLANTIC. AS WITH TUE NGT...POTENTIAL IS THERE WED NGT FOR
FROST/FREEZE MAINLY OVR THE PIEDMONT WITH TEMPS FORECASTED TO FALL
INTO THE MID 30S (LO 30S IS PSBL IN COLDEST SPOTS). WILL BE A BETTER
CHANCE FOR FROST WED NGT THAN TUE NGT AS WINDS WILL BE LIGHTER. BLO
NORMAL TEMPS CONTINUE INTO THU WITH HIGHS ONLY IN THE UPR 50S TO LWR
60S. THE SFC HI WILL REMAIN STRADDLED DOWN THE MID ATLANTIC CST THRU
FRI LEADING TO PROLONGED NE FLOW AND BLO NORMAL TEMPS. MID-LEVEL
ENERGY ARRIVES LATE FRI INTO SAT BRINGING THE NEXT CHANCE (30%) FOR
RAIN.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS OVER AREA TERMINALS THROUGH THE EVENING AND
OVERNIGHT. WINDS WILL BE MOSTLY S-SW 10-15 KT WITH SOME GUSTS UP
TO 20 KT THROUGH THE EARLY EVENING. MODEL GUIDANCE IN GOOD
AGREEMENT WITH INCREASING LOW LEVEL MOISTURE TONIGHT, WITH THE
POTENTIAL FOR SOME SCT-BKN LOW CLOUDS BETWEEN 1.5-2 KFT AFTER 06Z.

OUTLOOK...BREEZY SOUTHERLY WINDS WILL CONTINUE MONDAY/TUESDAY IN
ADVANCE OF A STRONG COLD FRONT, WHICH IS SET TO IMPACT THE
REGION MON NIGHT THROUGH EARLY WEDNESDAY. WIDESPREAD RAINFALL IS
EXPECTED DURING THIS PERIOD...WITH IFR VSBYS POSSIBLE IN HEAVIER
PRECIP ON TUESDAY. WIND GUSTS OF 30-35 KT ARE ALSO POSSIBLE.
IMPROVING CONDITIONS LATE TUE NGT/WED THROUGH FRIDAY AS HIGH
PRESSURE BUILDS INTO THE REGION FROM THE N-NW.

&&

.MARINE...
SFC HI PRES WILL REMAIN ANCHORED OFFSHORE TNGT LEADING TO
SOUTHERLY FLOW ACROSS THE AREA. SCA REMAINS IN EFFECT FOR THE BAY
THRU 1 AM WHERE THE PRES GRADIENT WILL KEEP WINDS CLOSE TO
CRITERIA. NO HEADLINES EXPECTED FOR THE COASTAL WTRS AT THIS
TIME...HOWEVER INCREASING WINDS LIKELY TO BRING SCA BY MONDAY
NIGHT AND CHANCE FOR GALE CONDITIONS BY TUESDAY WITH SEAS BUILDING
TO 6-8 FT. THE FRNT CROSSES THE WTRS TUE...WITH PROLONGED NE FLOW
THEREAFTER KEEPING SEAS ELEVATED AOA 5 FT THRU THE END OF THE
WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT MONDAY FOR ANZ630>632-634.

&&

$$
SYNOPSIS...LSA
NEAR TERM...MPR/LSA
SHORT TERM...LSA
LONG TERM...MAS
AVIATION...MAM/JEF
MARINE...MAS/JEF