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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 160143 AAA
AFDLWX

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

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE COAST TONIGHT AND SUNDAY. A
SURFACE TROUGH WILL RESIDE OVER THE AREA SUNDAY AFTERNOON. A COLD
FRONT WILL APPROACH ON MONDAY...MOVING SOUTHWARD THROUGH THE
REGION MONDAY NIGHT. LOW PRESSURE MAY RIDE ALONG THIS FRONT ON
TUESDAY...THEN HIGH PRESSURE BUILDS IN FOR THE REST OF THE WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --
A BRIEF BUT WELCOME PERIOD OF CALM OVER THE AREA THIS EVE...AHEAD
OF ANOTHER COUPLE OF ACTIVE DAYS TO BEGIN THE COMING WEEK. AFTER
YESTERDAY`S BREEZY/COOL CONDITIONS...HIGH PRESSURE ALLOWED FOR
SLIGHTLY WARMER TEMPS TODAY - AS WILL BE THE CASE TMRW AS WELL. A
CLUSTER OF DISSIPATING STORMS RACING ACROSS THE MID MS VLY
ATTM...W/ A MUCH LESS DEFINED BATCH OF LIGHT PRECIP CAUGHT IN THE
UPPER FLOW NOW CROSSING FROM ERN OH INTO WRN PA. THIS BATCH OF
LIGHT SHOWERS WILL DISSIPATE AND LARGELY STAY OUT OF THE NRN CWA
OVERNIGHT. THE SHORTWAVE TROUGH RESPONSIBLE FOR THE MID MS VLY
ACTIVITY WILL EVENTUALLY MAKE ITS WAY ACROSS THE MID ATLC DURING
THE DAYTIME HRS ON SUN.

THE AREA OF THE HIGH PRESSURE QUIETING DOWN CONDITIONS ACROSS THE
REGION WILL RETREAT BACK TO THE SRN ATLC COAST TONIGHT INTO
TMRW...AS THE SEVERAL WAVES OF UPPER VORTS SPEED TOWARD THE EAST
ALONG THE SRN PERIPHERY OF THE UPPER JET. ZOOMING OUT
FURTHER...NEAR LATITUDINALLY SYNCHRONOUS UPPER LOWS WILL CAUSE
THIS NEAR GEOSTROPHIC FLOW AS THE ROUND THE BASE OF THEIR
RESPECTIVE UPPER TROUGHS. BETWEEN THE TWO OF THEM...THEY ARE
BASICALLY TAKING THE CURRENT TROUGH AND RIDGES...FLATTENING THEM
OUT AND CAUSING THE UPPER FLOW TO MOVE FASTER FROM WEST-TO-EAST.
THIS WILL HELP THE ACTIVITY THAT`S NEARLY 1000 MILES AWAY COVER A
LOT OF GROUND IN THE NEXT 12-18HRS.

OVERNIGHT LOWS WILL END UP A BIT WARMER THAN LAST NIGHT...W/ MOST
AREAS STAYING IN THE 60S AS DEWPOINTS HAVE ONLY DROPPED A COUPLE
OF DEGREES AND WILL REMAIN FAIRLY MOIST HEADING INTO SUNDAY. THE
INCREASE IN WIND SPEEDS THROUGHOUT THE COLUMN WILL TRANSLATE SOME
OF THAT TO THE SFC DURING THE DAYTIME SUN AFTN...BRINGING BACK
SOME OF THE 20-25MPH BREEZES.

SVR WX PARAMETERS WILL BE A BIT TEMPERED TMRW...AS POCKETS OF
DENSE MID/UPPER DEBRIS CLOUDS STREAM ACROSS THE REGION FROM THE
INCOMING SHORTWAVE. TEMPS WILL STILL CLIMB WELL INTO THE 80S
ACROSS THE REGION...AND A GOOD RESURGENCE OF DEWPOINTS ALSO
EXPECTED AS WE ROUND THE U60S BY MID AFTN. COLUMN FLOW WILL BE
NEARLY UNIDIRECTIONAL ACROSS THE REGION...WHICH ISN`T TOO
FAVORABLE FOR CONVERGENCE AND WIDESPREAD ASCENT. WILL NEED TO
BREAK THE BOUNDARY LAYER CAP...WHICH WILL BE MORE LIKELY FOR A
BRIEF PERIOD TOWARD THE I-95 CORRIDOR LATER IN THE EVE...AS THE
COLD FRONT MOVES THRU. THE NAM SEEMS TO BE A BIT FASTER THAN THE
GFS AND A BIT MORE ACTIVE...BUT AM LEANING MORE TOWARD THIS
SOLUTION GIVEN THE INCREASED SPEED OF THE UPPER STEERING FLOW.
-- End Changed Discussion --

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
STORMS FROM SUNDAY AFTERNOON SHOULD WANE DURING THE EVENING. COLD
FRONT IS FORECAST TO APPROACH FROM THE NORTH MONDAY...MOVING
THROUGH MONDAY NIGHT. MODELS HAVE BACKED OFF SOME OF CHANCES OF
THUNDERSTORMS ON MONDAY. AM HESITANT TO TO REFLECT THIS TOO MUCH
AND CONTINUE WITH CHANCE POPS GIVEN BOUNDARY IN PLACE DURING
DAYTIME HEATING.

FOLLOWED HPC IDEA OF LOW PRESSURE TRACKING ALONG THE BAROCLINIC ZONE
ON TUESDAY. BAROCLINIC ZONE LOOKS TO BE JUST SOUTH OF THE CWA BY
THEN...BUT THERE IS SOME MODEL DISAGREEMENT WHICH WILL NEED TO
RESOLVED WITH TIME. AT THIS POINT...CONTINUED HIGH CHANCE/LOW
LIKELY POPS FOR TUESDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE BUILDS IN ON WEDNESDAY AND HOLDS THROUGH THE REST OF
THE WEEK AND POSSIBLY THE FIRST PART OF THE WEEKEND. BELOW CLIMO
TEMPERATURES WEDNESDAY ARE FORECAST TO MODERATE AROUND CLIMO FOR
THE REST OF THE LONG TERM.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT AND SUNDAY. NO FLIGHT
RESTRICTIONS EXPECTED THROUGH SUNDAY MORNING...THEN SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR THE AFTERNOON.

COLD FRONT APPROACHES MONDAY AND MOVES THROUGH MONDAY NIGHT. LOW
PRESSURE MAY RIDE ALONG THE FRONT...BRINGING SHOWERS/THUNDERSTORMS
INTO TUESDAY BEFORE HIGH PRESSURE BUILDS IN FOR WEDNESDAY.

&&

.MARINE...
SOUTHERLY FLOW RETURNS TONIGHT AS HIGH PRESSURE MOVES OFF THE COAST.
CONTINUE THE SCA IN EFFECT FOR SUNDAY...PARTICULARLY FOR THE
AFTERNOON AS MODELS SUGGEST 20 KT GUSTS. SCATTERED THUNDERSTORMS
WITH GUSTY WINDS MAY BE POSSIBLE SUNDAY AFTERNOON AND AGAIN MONDAY
AFTERNOON BEFORE A COLD FRONT MOVES THROUGH MONDAY NIGHT.

LOW PRESSURE RIDING ALONG THE FRONT MAY BRING UNSETTLED CONDITIONS
ON TUESDAY BEFORE HIGH PRESSURE BUILDS IN FOR WEDNESDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
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.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BPP/BJL/BAJ