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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 151613
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1213 PM EDT SAT JUN 15 2013

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER THE MID-ATLANTIC TODAY BEFORE MOVING
OFF THE COAST TONIGHT THROUGH SUNDAY. A COLD FRONT WILL SLOWLY
MOVE THROUGH THE REGION SUNDAY NIGHT INTO MONDAY NIGHT. A
DISTURBANCE MAY AFFECT THE AREA TUESDAY...THEN HIGH PRESSURE WILL
BUILD ACROSS THE REGION THROUGH THE MIDDLE PORTION OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BUILDS OVER THE MID-ATLANTIC TODAY. ASIDE FROM A FEW
CIRRUS SNEAKING IN FROM THE WEST...HIGH PRESSURE SHOULD GUARANTEE
PLENTY OF SUNSHINE TODAY WITH HIGH TEMPERATURES WARMING INTO THE
LOWER TO MID 80S ACROSS THE CWA EXCEPT FOR 70S OVER THE HIGHER
ELEVATIONS.

HIGH PRESSURE WILL MOVE OFF THE COAST TONIGHT...BUT IT WILL
REMAIN CLOSE ENOUGH FOR MORE DRY CONDITIONS. MIN TEMPS WILL RANGE
FROM THE MIDDLE 50S IN RURAL AREAS AND SHELTERED VALLEYS TO THE
UPPER 60S AND LOWER 70S IN DOWNTOWN WASHINGTON/BALTIMORE. THERE
WILL BE SOME HIGH AND MID-LEVEL CLOUDS MOVING IN OVERNIGHT WELL
AHEAD OF AN UPPER-LEVEL DISTURBANCE OVER THE MIDWEST.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
LARGE SCALE FEATURES SUNDAY THROUGH MONDAY NIGHT ARE A BERMUDA
HIGH...A TROUGH OVER THE NRN GREAT LAKES...AND A WEAK COLD FRONT IN
BETWEEN SAGGING ACROSS THE EAST-CENTRAL STATES.

SUNDAY...CONVERGENCE ZONE/COLD FRONT SAGS SOUTH INTO THE CENTRAL
MID-ATLANTIC THROUGH THE DAY. POPS INCREASE THROUGH THE DAY AS
FORCING SHIFTS INTO THE AREA IN THE PEAK HEATING OF THE AFTERNOON.
SCALED BACK LIKELY POPS FOR ALONG THE ALLEGHENY FRONT... WITH
SCATTERED COVERAGE EAST TO THE BAY. SWLY FLOW MIXES 16C 850MB
TEMPS...EXPECT MAX TEMPS MID TO UPR 80S...A FEW DEGREES ABOVE NORMAL.

CONVERGENCE ZONE AND ASSOCIATED PRECIP PERSISTS ACROSS THE AREA INTO
MONDAY NIGHT UNTIL LOW PRESSURE OVER THE GREAT LAKES FINALLY EJECTS
EAST...AMPLIFYING THE UPPER-AIR PATTERN AND PUSHING THE COLD FRONT
INTO THE SRN MID-ATLANTIC. MAINLY DIURNALLY DRIVEN THUNDERSTORMS
THROUGH MONDAY EVENING. SIMILAR TEMPERATURES MONDAY WITH 16C 850MB
TEMPS AGAIN.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
00Z OPERATIONAL GFS PROGS A SHORTWAVE LOW TO EJECT FROM COLORADO
SUNDAY NIGHT...RIDGE ALONG THE FRONTAL ZONE...AND TRACK ACROSS THE
CENTRAL MID-ATLANTIC TUESDAY NIGHT. THIS WOULD BE A FAVORABLE TRACK
FOR TUESDAY AFTERNOON/EVENING SEVERE WEATHER...INCLUDING TORNADOES
AND DAMAGING WINDS. ANY SHORTWAVE IN THE 00Z ECMWF (AS WELL AS THE
PREVIOUS 12Z RUN) IS TOO WEAK TO DEVELOP A SURFACE FEATURE.
FURTHERMORE...MOST GEFS ENSEMBLE MEMBERS DO NOT FEATURE A LOW BELOW
1005MB IN THE MID-ATLANTIC ON MONDAY. THIS GREATLY LIMITS CONFIDENCE
IN THE SEVERE THREAT FOR TUESDAY. WILL CONTINUE TO REFRAIN FROM
MENTIONING THIS IN THE HWO.

OTHERWISE...SURFACE HIGH PRESSURE WILL SHIFT ACROSS THE REGION
THROUGH THE MIDWEEK WITH A REPRIEVE FROM THE ACTIVE WEATHER AND EVEN
A SHOT OF CANADIAN AIR AND BELOW NORMAL TEMPERATURES.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE BUILDS OVERHEAD TODAY...THEN MOVES OFF THE COAST
TONIGHT. NO FLIGHT RESTRICTIONS EXPECTED DURING THIS TIME...WITH
LIGHT W/NW WINDS BECOMING S THIS EVENING.

VFR CONTINUES INTO SUNDAY AS HIGH PRESSURE MOVES TO BERMUDA.
SCATTERED THUNDERSTORMS AHEAD OF A WEAK COLD FRONT SPREAD ACROSS THE
TERMINALS SUNDAY AFTERNOON WITH AN ACTIVE PERIOD THEN INTO MONDAY
EVENING WITH DIURNALLY DRIVEN CONVECTIVE STORMS.

&&

.MARINE...
NO MARINE HEADLINES ARE EXPECTED THROUGH TONIGHT. A NORTHWEST FLOW
WILL TURN ONSHORE BY LATE IN THE DAY. SOUTHERLY WINDS WILL INCREASE
TONIGHT AS HIGH PRESSURE MOVES OFF THE COAST...BUT WIND SPEEDS
SHOULD REMAIN BELOW SCA CRITERIA.

SLY/SWLY FLOW INCREASES SUNDAY WITH MORNING SLY CHANNELING AND
AFTERNOON SWLY FLOW GUSTING AROUND 25 KT AS INDICATED BY SCA
COVERAGE THAT BEGINS 6 AM FOR SRN MD WATERS...AND IS ACROSS ALL
WATERS BY 10 AM. SCA LIKELY EXTENDED FOR PORTIONS OF THE WATERS
FOR SUNDAY EVENING. ACTIVE WEATHER SUNDAY EVENING INTO MONDAY
NIGHT OVER THE WATERS AS A COLD FRONT SAGS THROUGH THE AREA.

&&

.TIDES/COASTAL FLOODING...
-- Changed Discussion --
HIGH TIDE HAS PASSED AT ANNAPOLIS...APAM2 REACHED NEAR 2.6 FT
MLLW. HAVE ALLOWED ADVISORY TO EXPIRE FOR CALVERT/ANNE ARUNDEL.
ANOMALIES HAVE ACTUALLY DECREASED A LITTLE OVER THE PAST COUPLE OF
HOURS. THIS MEANS WATER LEVELS WILL BE A LITTLE LOWER THAN
PREVIOUSLY PREDICTED ACROSS SOUTHERN BALTIMORE/HARFORD COUNTIES.
SENSITIVE AREAS MAY STILL BE CLOSE TO MINOR TIDAL FLOOD THRESHOLDS
BUT WILL CONTINUE TO MONITOR IN CASE COASTAL FLOOD ADVISORY MAY
NEED TO BE CANCELLED EARLY.
-- End Changed Discussion --

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR
     MDZ007-011.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EDT SUNDAY FOR
     ANZ530>533-535-536-538>542.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT SUNDAY FOR ANZ534-
     537-543.
-- End Changed Discussion --

&&

$$
BPP/BJL/BAJ