000
FXUS61 KCTP 200939
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
539 AM EDT THU JUN 20 2013

.SYNOPSIS...
AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL BRING VERY WARM AND
HUMID WEATHER TO CENTRAL PENNSYLVANIA THROUGH EARLY NEXT WEEK. A
FEW ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE IN THE
SUMMERTIME PATTERN. A COLD FRONT PUSHING SOUTHWARD FROM THE GREAT
LAKES REGION SHOULD BRING THE NEXT CHANCE FOR WIDESPREAD SHOWERS
AND THUNDERSTORMS BY NEXT WEDNESDAY OR THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A CHILLY MORNING IS IN PROGRESS ACROSS CENTRAL PA...THE RESULT OF 
HIGH PRESSURE AND ASSOC COOL/DRY AIR MASS. 08Z SFC OBS SHOW SOME OF 
THE NORMALLY COLDER VALLEYS HAVE FALLEN TO THE L40S. AS OCCURRED 
YESTERDAY AM...EXPECT THE COOL TEMPS AND RELATIVELY WARM  
RIVER/STREAM WATERS TO RESULT IN PATCHY VALLEY FOG IN THE DEEP 
VALLEYS NORTH OF I-80.  

AS SFC HIGH SLIPS OFF THE NJ COAST...A RETURN SSE FLOW SHOULD DRAW 
LOW LVL MOISTURE NORTHWARD ALONG THE EAST SLOPES OF THE 
APPALACHIANS. THE INCREASED MOISTURE SHOULD RESULT IN A FAIR AMT OF 
CU BY AFTN ACROSS THE CENTRAL MTNS. THE LATEST NAM/RUC AND HI-RES 
WRF DEPICT ISOLD SHOWERS DEVELOPING INVOF THE LAUREL MTNS AND 
S-CNTRL RIDGES WITHIN NARROW AXIS OF INSTABILITY EXTENDING NWD ALONG 
THE SPINE OF THE CNTRL APPALACHIANS. ALTHOUGH AREAL COVERAGE 
PROBABLY DOESN/T WARRANT AN EXPLICIT MENTION IN THE FCST...WILL 
INCREASE POPS TO ARND 10 PCT DURING THE LATE AFTN AND EVENING TO 
ACCOUNT FOR POSSIBLE ISOLD SHRA/TSRA. 

UNDER PT-MOSUNNY SKIES...TEMPS TODAY SHOULD BE SEVERAL DEG WARMER 
THAN WED BASED ON SREF 8H TEMPS WARMING ARND 2C. 

GIVEN LACK OF ANY LG SCALE FORCING...ANY ISOLD EVENING SHRA/TSRA 
ACROSS THE CENTRAL COUNTIES SHOULD DIE OUT AFTER SUNSET. FOR THE 
REST OF THE NIGHT...ONLY CONCERN MAY BE SOME PATCHY FOG. LIGHTEST 
WIND AND BEST POTENTIAL OF FOG APPEARS TO BE ACROSS THE W MTNS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AN ANOMALOUS 500MB RIDGE WILL TAKE UP RESIDENCE OVER THE REGION
DURING THE SHORT TERM PERIOD...DOWNSTREAM OF A CLOSED LOW
ROTATING NEWD FROM THE NRN ROCKIES INTO SOUTH-CENTRAL CANADA.
THIS WILL MARK THE START OF A VERY WARM/HUMID STRETCH OF WEATHER
FOR THE LOCAL AREA - WHICH IS ARRIVING ON SCHEDULE WITH THE
OFFICIAL START OF ASTRONOMICAL SUMMER ON FRIDAY /SEE CLIMATE
SECTION/.

APPRECIABLE RNFL WILL BE HARD TO COME BY IN THIS LATE-SUMMERTIME
PATTERN...WITH MDL DATA SHOWING AN ALMOST DAILY CHANCE OF DIURNAL
CONVECTION. CAPPING INVERSION/WARM 700MB TEMPS AND OVERALL LACK OF
FORCING SHOULD KEEP AIRMASS CONVECTION TO MINIMAL CVRG. CONSENSUS
OF MDL DATA FOCUSES PCPN TO THE NORTH OF CENTRAL PA - ALONG WEST-
EAST FRONTAL ZONE LOCATED ON THE SRN EDGE OF THE WESTERLIES EXTENDING
FROM THE NRN PLAINS SEWD THRU THE GRT LKS INTO THE NORTHEAST
STATES. OVERALL EXPECT ABOVE NORMAL MAX/MINS...LITTLE TO NO
RAINFALL AND SOME FOG IN THE MORNINGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE VERY WARM AND HUMID CONDS WILL CONTINUE FROM LATE IN THE
WEEKEND THROUGH EARLY NEXT WEEK...ALONG WITH THE DAILY CHC FOR
AFTN SHOWER OR TSTM. GLOBAL MDL AND ENSEMBLE DATA SHOW THE UPPER
LEVEL RIDGE RETROGRADING /MOVG WWD/ INTO THE FOUR CORNERS DURING
THE SECOND HALF OF NEXT WEEK. THIS SHOULD ALLOW SHORTWAVE ENERGY
TO ENTER THE GREAT LAKES REGION AND PUSH A COLD FRONT SWD ACRS THE
REGION AROUND DAY 7-8. THE 20/00Z GEFS AND ECENS SHOW A WRN
RIDGE/ERN TROUGH 500MB CONFIGURATION HEADING INTO THE SECOND HALF
OF NEXT WEEK.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
MODIS 11-3.7UM IMAGERY SHOWING PATCHY FOG HAS DEVELOPED IN THE
DEEP RIVER VALLEYS OF THE ALLEGHENIES. HOWEVER...OTHER THAN 5SM
VSBYS AT UNV AND LNS...ALL AIRFIELDS ARE VFR AT 09Z AND EXPECT
IMPROVING CONDS AFTER 10Z WITH SUNRISE. 

HIGH PRESSURE PASSING OFF THE NJ COAST SHOULD SUPPLY VFR CONDS AND
LGT WINDS TO THE AREA LATER TODAY. HOWEVER...CAN/T RULE OUT AN
ISOLD PM TSRA DEVELOPING ALONG THE SPINE OF THE APPALACHIANS FROM
JST AND AOO NORTH THRU UNV. 

OUTLOOK... 

FRI...PATCHY AM FOG POSSIBLE W MTNS.
SAT...NO SIG WX EXPECTED.
SUN-MON...ISOLD PM TSRA IMPACTS POSSIBLE.

&&

.CLIMATE...
ASTRONOMICAL SUMMER 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...FITZGERALD
CLIMATE...