-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCTP 191018
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
618 AM EDT WED JUN 19 2013

.SYNOPSIS...
-- Changed Discussion --
THE PERSISTENT/BROAD MEAN TROUGH WILL BE REPLACED BY AN UPPER
LEVEL RIDGE MIGRATING EASTWARD FROM THE PLAINS. THIS PATTERN
SHIFT WILL BRING SOME OF THE WARMEST AIR OF THE SEASON TO THE
AREA...WITH THE INCREASING HEAT AND HUMIDITY ARRIVING ON SCHEDULE
WITH THE OFFICIAL START OF ASTRONOMICAL SUMMER. TEMPERATURES
ARE FORECAST TO REMAIN ABOVE NORMAL OVER THE WEEKEND AND INTO NEXT
WEEK. SHOWER ACTIVITY WILL BE FOCUSED ALONG A WEST-EAST ORIENTED
JET STREAM AND FRONTAL BOUNDARY EXTENDING FROM THE UPPER MIDWEST
INTO THE NORTHEAST.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
IR SATL SHOWS THE NW EDGE OF LYRD CLOUD SHIELD FROM MGW/UNV/AVP AS
OF 0830 UTC. EXPECT SURGE OF DRIER/LOW PWAT AIR TO CONTINUE TO
PRESS SEWD EARLY THIS MORNING...RESULTING IN IMPROVING CONDS FOR
THE SERN 1/2 OF THE CWA BY MID MORNING. RADAR SHOWS SHOWERS HAVE
DISSIPATED OR MOVED SOUTH INTO MD. THE ONLY WEATHER TO SPEAK OF IS
PATCHY FOG/STRATUS ACRS THE SRN TIER...WHICH SHOULD NOT LAST LONG
AS DRIER AIR/NORTHERLY WIND OVERCOMES RESIDUAL BLYR MSTR.

H5 HGTS WILL START TO RISE AS THE MEAN NERN CONUS TROUGH FINALLY
LIFTS OUT. HIGH PRES WILL BRING FAIR WX TO THE AREA TODAY WITH LOW
HUMIDITY AND PLEASANT/COMFORTABLE TEMPERATURES. CLR SKIES AND LOW
PWATS WILL MAKE FOR A CHILLY NIGHT ESPECIALLY ACRS NRN PA WHERE
NIGHTTIME LOWS WILL FALL INTO THE LOW 40S/UPPER 30S. THE GFS-
BASED MAV GUID HAS 36F FOR BFD SUGGESTING SOME PATCHY FROST MAY
EVEN BE POSSIBLE. THIS IS THE LOWEST MOS GUID WHEN COMPARED
AGAINST THE NAM/MET...EC/ECM AND IS ON THE LOW END OF THE 18/00Z
ECENS MEMBERS. WILL PASS THIS ALONG TO THE DAYSHIFT FOR FUTURE
CONSIDERATION.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
UPPER RIDGE OVER THE PLAINS STATES WILL SHIFT EWD THIS PERIOD AS
A DEEP CLOSED LOW MOVES FROM THE PAC NW INTO THE NRN ROCKIES. H5
HGTS CLIMB ABOVE NORMAL BY FRIDAY. WINDS WILL VEER AROUND TO THE
SOUTH/SOUTHWEST AS THE SFC HIGH MOVES OFF THE MID-ATLC COAST. THE
RETURN FLOW WILL RESULT IN AN INCREASE IN DAYTIME TEMPS AND LLVL
MSTR/DEWPOINTS/HUMIDITY. THE WARMER PATTERN WILL ARRIVE ON
SCHEDULE WITH THE FIRST DAY OF ASTRONOMICAL SUMMER /SEE CLIMATE
SECTION FOR MORE DETAILS/. MDL DATA SUGGESTS ISOLD DIURNAL
CONVECTION IS POSSIBLE ALONG THE SPINE OF THE N-CNTRL APPALCHNS
INTO THE LAUREL HIGHLANDS/S-CNTRL RIDGES...BUT FOR THE MOST PART
EXPECT MOST AREAS TO STAY RAIN-FREE. CAPPING INVERSION MAY BE A
LIMITING/NEGATIVE FACTOR FOR TERRAIN-INDUCED TSTMS LATER THIS WEEK.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
NRN ROCKIES 500MB TROUGH WILL EJECT NEWD INTO THE S-CNTRL CANADIAN
PRAIRIES OVER THE WEEKEND...ALLOWING THE SUBTROPICAL RIDGE TO
RETROGRADE AND EXPAND WWD BACK ACRS THE SRN PLAINS. WITH BROAD
SUBTROPICAL RIDGING COVERING THE SRN 1/2 OF THE CONUS...THE JET
STREAM WILL BE CONFINED ALONG THE US/CANADIAN BORDER - WHICH IS
WHERE IT SHOULD BE FOR THIS TIME OF YEAR. THE GLOBAL MODEL AND
ENSEMBLE GUIDANCE SHOWS ANOTHER WEAK TROUGH DEVELOPING OVER THEN
NORTHEAST STATES BY THE MIDDLE OF NEXT WEEK...AS THE UPPER RIDGE
BECOMES MORE PRONOUNCED AND BUILDS NWD ACRS THE GREAT BASIN/INTER
MTN WEST.

THE MAIN SENSIBLE WEATHER IMPACT THIS PERIOD SHOULD BE THE HEAT
AND HUMIDITY...WITH ABOVE NORMAL TEMPS EXPECTED TO LAST INTO THE
MIDDLE OF NEXT WEEK. A CONSENSUS OF 19/00Z MED RANGE MOS GUID AND
HPC SHOWS MAX TEMPS RANGING BTWN 80-85F ACRS THE ALLEGHENIES AND
85-90F E OF THE MTNS IN THE CNTRL RIDGES AND SUSQ VLY. IN THE
SUMMERTIME PATTERN...PCPN OPPORTUNITIES WILL BE HARD TO PINPOINT
AND THUS DAY 4-7 POPS CAME OUT LOOKING VERY CLOSE TO CLIMO WITH
MODIFIED DIURNAL TREND.

&&

.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
SCATTERED SHOWERS ACROSS THE LOWER SUSQ CONTINUE TO WEAKEN AS THE
EVENING PROGRESSES. MOST SITES WILL REMAIN VFR OVERNIGHT...BUT SOME
MVFR CONDITIONS ARE POSSIBLE FROM JST EASTWARD AS THE SHOWERS
MEANDER ABOUT. BEST CHANCE FOR REDUCED CONDITIONS WILL BE WHERE IT
RAINED THIS EVENING.

ANY EARLY MVFR OVER SRN AREAS WILL IMPROVE SHORTLY AFTER SUNRISE
LEADING TO WIDESPREAD VFR WEDNESDAY AS HIGH PRESSURE BUILDS OUT OF
THE GR LAKES.

HIGH PRESSURE WILL CONTROL THE WX INTO THE WEEKEND.

OUTLOOK...

THU-FRI...NO SIG WX EXPECTED.

SAT-SUN...ISOLD PM TSRA IMPACTS POSSIBLE.

&&

.CLIMATE...
SUMMER OFFICIALLY BEGINS AT 104 AM EDT ON FRIDAY JUNE 21ST.

&&

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

&&

$$
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...STEINBUGL
AVIATION...LA CORTE/CERU
CLIMATE...STEINBUGL