000
FXUS61 KPBZ 170923
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
523 AM EDT MON JUN 17 2013

.SYNOPSIS...
A SERIES OF UPPER DISTURBANCES WILL SPAWN PERIODIC SHOWER AND
THUNDERSTORM CHANCES THROUGH TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK UPPER LEVEL SHORTWAVE OVER THE FORECAST AREA HAS RESULTED IN
DEVELOPING SHOWERS SOUTH OF PIT. AS THE SHORTWAVE EXITS...SHOWERS
SHOULD DIMINISH LATER THIS MORNING.

SWD PROGRESS OF THE SFC FRONT IS QNABLE GIVEN ZONAL FLOW AND
SATELLITE INDICATIONS OF A STRONGER UPSTREAM SHRTWV. THOSE
FEATURES ARE EXPECTED TO SPPRT MORE SHWR AND TSTM CHCS LTR TDA AND
THIS EVENING. FOR NOW...HAVE SHIFTED AFTN AND EVE POPS NWD AND
UPPED TO CHC NMBRS IN CONJUNTION WITH INCOMING NAM AND GFS SOLNS.

TIMING AND SFC DEWPOINT FORECAST AT MOMENT LKS TO BE SUFFICIENTLY
QNABLE THAT INSTABILITY MIGHT DIMINISH ENUF TO PRECLUDE SVR...BUT
GIVEN DEEP LYR SHEAR AND GLOOMY NAM CONVECTIVE FORECASTS...SITUATION
WL HAVE TO BE MONITORED TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
CHC POPS WERE MAINTAINED TONIGHT...BUT SHIFTED SWD INTO TUESDAY AS
SECONDARY FRONT/OUTFLOW PROGRESS AS ANOTHER DISTURBANCE/JET
STREAK CROSS THE REGION.

DRY HIGH PRES WL BLD THEREAFTER AND SUPPRESS PCPN FOR WEDNESDAY
AND THURSDAY...BUT SEASONABLY COOL AIR UNDR TROFG ALOFT WL LIMIT
TEMP RECOVERY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MDLS CONT TO DEPICT DVLPMNT OF A BROAD SRN CONUS RIDGE FOR THE
LONG TERM PD WITH GENL RIDGE AXIS POSITIONING ACRS THE GREAT
LAKES. WARMER TEMPS ARE THUS IN STORE FOR THE UPR OH VALLEY REGION
WITH WEEKEND READINGS PROGGED WELL INTO THE 80S AS PER HIGHER MOS
GUIDANCE.

GRADUALLY INCRSG POPS...TO CHC NMBRS FOR THE WEEKEND...WERE ALSO
INCLUDED...BUT TIMING WL BE DEPENDANT ON SHRTWV PASSAGE ACRS THE
NRN PERIPHERY OF THE RIDGE...SO CONFIDENCE IN THAT PARAMETER IS
MINIMAL AT THIS JUNCTURE OF THE FORECAST PROCESS.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
SCT/ISOLD SHWRS WL RMN A POSSIBILITY TNGT AS SFC FRONT SAGS SWD AND
STALLS. IN ADDITION...SFC MSTR WL TRAP UNDR BLDG INVERSION AND
POSSIBLY SPPRT FOG AREAS BY MRNG. WITH BOTH LAMP AND NAM MOS
GUIDANCE SUGGESTING AT LEAST MVFR FOG
EVERYWHERE...HAVE PERSISTED WITH THAT FORECAST AS WELL AS IFR AT THE
MORE FAVORABLE PORTS. OTHERWISE CONFIDENCE IN PCPN PLACEMENT IS
LOW...SO MENTION WL BE OMITTED UNTIL A MORE DECISIVE SIGNAL IS
RECEIVED. AT MOMENT...SHWRS ARE NOT EXPECTED TO GENERATE IFR VSBY OR
CIGS.

IMPROVEMENT TO VFR IS EXPECTED AFTER SUNRISE...BUT MORE
RESTRICTIONS ARE POSSIBLE LTR IN THE DAY AS ANOTHER DISTURBANCE
APPRCHES AND INCRS SHWR AND TSTM CHCS...ESPECIALLY FOR PORTS N OF
I 70.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
PERIODIC RESTRICTIONS ARE ANTICIPATED THROUGH TUESDAY A CDFNT CROSSES
THE REGION. BLDG HIGH PRES SHOULD RTN VFR CONDITIONS FOR THE
REMAINDER OF THE WORKWEEK.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$