-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 241252
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
852 AM EDT FRI MAY 24 2013

.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
MADE ONLY SLIGHT ADJUSTMENTS...MAINLY TO LOWER DIURNAL TEMPERATURE
TREND FOR THE FIRST HALF OF THE DAY AS CLOUD COVER WILL MAKE IT
DIFFICULT FOR TEMPERATURES TO RISE RAPIDLY...AT LEAST INITIALLY.
OTHERWISE...SCATTERED SHOWERS/DRIZZLE CONTINUES FOR POINTS EAST OF
THE PA/WV/OH LINE THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
SHWRS CONT TO DIMINISH IN COVERAGE IN THE WAKE OF LAST EVES CDFNT
AND PCPN FORECAST HAS THUS BEEN ADJUSTED FOR THE LATEST OBS AND
RADAR TRENDS. IN GENL...SHWR AREA TO THE EAST OF PITTSBURGH WL
PROGRESS AND SCT THROUGH THE MRNG AS COLDER AIR FLOWS OVR THE
REGION UNDR A RELATIVELY LOW INVERSION LVL. THAT PTN WL WL
MAINTAIN SOME STRATOCU TDA...BUT OVRALL DRYING WL HERALD REDUCED
CLD COVER AS THE DAY PROGRESSES.

INITIAL TEMPS WERE FORECAST USING OB-TWEAKED LAMP GUIDANCE WHILE
TNGTS COLD READINGS WERE A RESULT OF A GFS MOS AND NAM BLEND. FOR
THE RIDGES AND AREAS NORTH OF PITTSBURGH...SUSTAINED WIND SHOULD
PRECLUDE FROST...BUT COLD ADVCTN IS EXPECTED TO BE SUFFICIENT TO
SPPRT A FREEZE. HENCE...A FREEZE WARNING HAS BEEN INCLUDED WITH
THIS MRNGS PACKAGE.

FOR COUNTIES WEST AND SOUTH OF PIT...WIND MAY DIE VIA DECOUPLING
AND DIMINISHED PRES GRADIENT WITH THE HIGH SETTLING TOWARD THE MID
OHIO VALLEY...SO HAVE OPTED FOR A FROST ADVISORY IN COLLABORATION
WITH THE NEIGHBORS...BUT DAY SHIFT WL HAVE TO MONITOR FOR A
DEGRADE/UPGRADE TO A FREEZE WARNING.
-- End Changed Discussion --

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
DRY SFC HIGH PRES UNDR NW FLOW ALOFT WL MAINTAIN COLD TEMPS
THROUGH THE WEEKEND. EXPECT READINGS OF 10 TO 15 DEGREES UNDR THE
AVERAGES WITH FROST POTENTIAL AGAIN ON SATURDAY NGT.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
SFC HIGH PRES IS EXPECTED TO MAINTAIN DRY WEA UNTIL A WARM FRONT
INCREASES PCPN CHCS FOR WEDNESDAY AND THURSDAY. INITIALLY COLD TEMPS
WL MODERATE TO...AND THEN ABOVE SEASONAL LVLS AS SLY FLOW RESUMES
BY MID WEEK.

&&

.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
EARLY MRNG IFR AND MVFR ST AND STRATOCU CEILINGS ARE EXPECTED TO
IMPROVE AS THE DAY PROGRESSES WITH DRY ADVCTN GRADUALLY INCRSG T/DP
SPREADS DESPITE COLD FLOW. WIND GUSTS TO ABOUT 22 KTS CAN BE EXPECTED
IN THE SHALLOW MIXING REGIME. THAT POTENTIAL WL CEASE WITH
DECOUPLING THIS EVE.

.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
HIGH PRESSURE WL MAINTAIN VFR THROUGH EARLY NXT WEEK.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR MDZ001.
OH...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR OHZ039>041-
     048>050-057>059-068-069.
PA...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ020-021-
     029-031-073-075.
     FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR PAZ007>009-
     013>016-022-023-074-076.
WV...FROST ADVISORY FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ001>004-
     012-021-022.
     FREEZE WARNING FROM 3 AM TO 8 AM EDT SATURDAY FOR WVZ023-041.

&&

$$