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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 180738
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
338 AM EDT TUE JUN 18 2013

.SYNOPSIS...
-- Changed Discussion --
THE PERSISTENT JUNE PATTERN OF BROAD TROUGHING OVER THE MID-
ATLANTIC AND NORTHEAST STATES IS FORECAST TO TRANSITION AND BE
REPLACED BY A SUMMERTIME UPPER LEVEL RIDGE MIGRATING EASTWARD
FROM THE PLAINS. FOLLOWING THE PASSAGE OF A SURFACE COLD FRONT
TODAY INTO TONIGHT...THE PATTERN WILL DRY OUT INTO THE SECOND
HALF OF THE WEEK WITH INCREASING HEAT AND HUMIDITY ARRIVING ON
CUE WITH THE OFFICIAL START OF ASTRONOMICAL SUMMER.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
BELT OF STRONGER MID-LVL FLOW ON THE SRN EDGE OF SHORTWAVE TROUGH
MOVG EWD FROM QUEBEC TO THE MARITIMES WILL SHIFT EWD ACRS NEW
ENGLAND THIS MORNING. AN ATTENDANT SFC COLD FRONT DRAPED ALONG THE
LWR LKS IS TEAMING WITH A WELL-DEFINED 300MB JET ENTRANCE REGION
TO MAINTAIN BAND OF SHOWERS/TSTMS OVER NW PA. MESO MODELS WEAKEN
THIS AREA OF PCPN AS IT SHIFTS EWD ACRS BFD VCNTY THRU THE PREDAWN
HOURS. OUTSIDE OF THE NW MTNS...ANY SHOWER ACTIVITY SHOULD REMAIN
ISOLD AT BEST WITH MOST AREAS STAYING DRY THRU DAYBREAK.

IR SATL LOOP SHOWS A SHIELD OF LYRD MID-HIGH CLOUDS SPREADING NEWD
ACRS THE UPPER OH VLY INTO CNTRL PA. THESE CLOUDS ARE ASSOCD WITH
A SHORTWAVE LIFTING THRU TN/KY TWD THE SRN MID-ATLC REGION.
ANOTHER MORE PROMINENT/COMPACT SHORTWAVE CURRENTLY ROTATING ACRS
ND/SD/MN WILL TRACK SEWD INTO THE LWR-MID OH VLY BY THIS AFTN. THE
APPROACHING SHORTWAVE ENERGY AND SFC COLD FRONT SHOULD PROVIDE
SUFFICIENT FORCING/LIFT TO FUEL TSTM DEVELOPMENT INTO THE AFTN.
HOWEVER THERE IS SOME QUESTION AS TO WHERE THE BEST LOCATION/AERIAL
CVRG WILL BE. THE SVR THREAT APPEARS MARGINAL...LIMITED TO SOME
EXTENT BY WEAK INSTABILITY. CANT RULE OUT A FEW ORGANIZED STORMS
GIVEN 35-40 KT OF EFFECTIVE BULK SHEAR. FINALLY COULD ALSO SEE
SOME LOCALLY HEAVY RAINS WITH THE MAIN SURGE OF ANOMALOUS PWATS
PROGGED OVER SOUTHEAST PA. OVERALL DON`T HAVE A GREAT HANDLE ON
HOW THINGS WILL EVOLVE LATER TODAY.

THE FRONT WILL PUSH SOUTH ACRS THE CWA BY LATER TONIGHT WITH MUCH
DRIER/BELOW NORMAL PWAT AIR ARRIVING FROM THE NORTH. WILL HOLD
ONTO SOME LOW POPS ALONG THE MASON DIXON LINE INTO EARLY WEDNESDAY
BUT MOST AREAS SHOULD BE DRY AFT 06Z...ESPECIALLY NORTH OF THE
TURNPIKE.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
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HIGH PRES WILL PREVAIL ON WEDNESDAY BRINGING PLENTY OF SUNSHINE.
IT SHOULD BE A VERY COMFORTABLE DAY WITH NLY WINDS AND LOW
HUMIDITY...WITH TEMPS IN THE 70S. CLR/CALM CONDS WED NIGHT SHOULD
ALLOW OVERNIGHT LOWS TO FALL INTO THE LOW-MID 40S ACRS THE NRN
TIER. SOME USUAL COLD SPOTS IN THE NRN MTNS COULD DIP INTO THE
UPPER 30S.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
AS RIDGE CONTINUES TO SLIP TO THE SE...LIGHT SOUTHWESTERLY FLOW
DEVELOPS THU. MOISTURE WILL BE SLOW TO INCREASE THU AND FRI...BUT
WEAKENING CAP WILL LEAD TO INCREASING CHANCES FOR ISOLATED LATE
DAY TSTMS OVER SOUTHERN HALF.

LARGER RIDGE OVER CENTRAL U.S. BUILDS EASTWARD INTO OHIO VALLEY
THIS WEEKEND. HIGHER TEMPS AND DEWPOINTS WILL ADVECT EASTWARD
AROUND TOP OF THE RIDGE...ARRIVING IN PA ON SAT AND PERSISTING FOR
SEVERAL DAYS...KICKING OFF DAILY SCT TSTMS /MAINLY NW HALF/. WE/LL
ALSO LIKELY SEE DECAYING MCS/S TRYING TO SLIDE EASTWARD INTO PA
SUNDAY AND MONDAY MORNING. THIS PATTERN WILL PERSIST UNTIL NEXT
FRONT COMES THROUGH MIDWEEK NEXT WEEK.
-- End Changed Discussion --

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
REGIONAL RADAR LOOP THIS EVENING SHOWS SHRA/TSRA ACROSS THE LOWER
GRT LKS IN ASSOCIATION WITH A SLOW-MOVING COLD FRONT. AS THIS
FRONT WORKS SE...A LATE NIGHT SHRA IS POSSIBLE OVR NORTHERN PA.
HOWEVER...THE BIGGEST AVIATION CONCERN TONIGHT IS THE POSSIBILITY
OF FOG AT BFD...MDT AND LNS...ESPECIALLY AT THE MDT AND LNS WHERE
RAIN HAS FALLEN. COUPLE THIS WITH MCLEAR SKIES...A LGT WIND AND WET
GROUND ALL FAVOR DEVELOPMENT OF FOG OVERNIGHT.
CURRENT SAT SHOT SHOWS CIRRUS MOVING OVER THE REGION...THIS WILL
REDUCE THE DEVELOPMENT AND THE SEVERITY OF ANY FOG/MIST. THE
CLEARING SKIES OVER BFD HAVE ALLOWED FOR IFR CONDITIONS TO
DEVELOP...OUT AHEAD OF THE APPROACHING FRONT. MVFR CONTINUES AT
LNS AND MVFR SHOULD DEVELOP AT MDT. IFR REMAINS POSSIBLE AT
MDT...LNS AND IPT. A THICK LAYER OF MID CLOUDS HAS DEVELOPED OVER
THE CENTRAL TAF SITES AND SHOULD NEGATE ANY FOG FORMATION.

ANY FOG THAT MANAGES TO FORM OVERNIGHT SHOULD BURN OFF WITHIN A
COUPLE HRS AFTER SUNRISE. FOCUS WILL THEN SHIFT TOWARD SCT
SHRA/TSRA DEVELOPING TUES AFTN...AS COLD FRONT WORKS SOUTH ACROSS
THE STATE. ALTHOUGH VFR CONDS WILL PREDOMINATE...A BRIEF VSBY
REDUCTION IS POSSIBLE WITH ANY SHRA/TSRA. CURRENT MODELS SHOW ANY
PRECIPITATION COULD LINGER ALONG THE MASON DIXON LINE...AND AT
LNS...MDT AND JST THROUGH 06Z WEDNESDAY. IFR CIGS AND VSBYS WILL
AGAIN BE A POSSIBILITY TOMORROW NIGHT.

OUTLOOK...
WED...EARLY AM LGT RAIN/LOW CIGS POSSIBLE JST/AOO.
THU...NO SIG WX EXPECTED.
FRI-SAT...ISOLD PM TSRA IMPACTS POSSIBLE.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...RXR
AVIATION...FITZGERALD/CERU