-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 070829
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
329 AM EST SAT DEC 7 2013

.SYNOPSIS...
SNOW SHOWERS WILL BE ENDING LATE TONIGHT. COLDER AIR WILL SETTLE
IN FOR THE REMAINDER OF THE WEEKEND. ANOTHER MIXED PRECIPITATION
EVENT IS POSSIBLE SUNDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
CAA WILL BE ONGOING THROUGHOUT THE DAY AS THE FLOW ALOFT BECOMES
NORTHWESTERLY AND INCREASES. TEMPS WILL RECOVER VERY LITTLE TODAY
WITH THE CHANGE IN AIR MASSES AND CLOUD COVER. LATEST FORECAST
SOUNDINGS ARE SHOWING A STRATOCU LAYER HOLDING ON FOR MUCH OF THE
AREA TODAY.
-- End Changed Discussion --

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
HIGH PRESSURE WILL KEEP THE AREA DRY AND COLD TONIGHT.

LOW CONFIDENCE IN THE NEXT EVENT ON SUNDAY. THIS IS LARGELY DUE TO
THE WIDE VARIANCES IN MODEL SOLUTIONS. THERE ARE BIG DIFFERENCES
IN THE PRECIP TIMING...COVERAGE AND DURATION. ALSO...NOTICEABLE
DIFFERENCES IN THE THERMAL PROFILE BETWEEN MODELS. IT DOES LOOK AS
THOUGH THERE WILL BE A MIXED PRECIP EVENT...BUT THE RAPID
INTRUSION OF A LARGE MID-LEVEL DRY SLOT AND THE LOSS OF UPPER
LEVEL SUPPORT PROVIDE MORE QUESTIONS THEN ANSWERS. THE
SUNDAY/SUNDAY NIGHT PORTION OF THE FORECAST WILL NEED MUCH
REFINING OVER THE NEXT 24 HOURS.

COLD FRONT WILL MOVE THROUGH MONDAY MORNING...BRINGING AN END TO
THE RISK FOR PRECIPITATION AND INTRODUCING THE NEXT PUSH OF COLD
AIR.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MUCH COLDER AND DRIER AIR WILL BE SHUNTED OVR THE UPPER OHIO VALLEY
REGION IN THE WAKE OF MONDAYS COLD FRONT. COLD TEMPS AND GENLY
PCPN FREE POPS WERE FORECAST USING A COMBO OF WPC AND MOS
GUIDANCE. ONLY LOW POPS ACROSS THE FAR NORTH WERE MAINTAINED.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
CONDITION IMPROVEMENT CAN BE EXPECTED TDA AS HIGH PRES BLDS AND AS
DRIER AIR ADVECTS OVR THE UPR OH REGION. MVFR WL PLAGUE THE MRNG
THOUGH AS STRATOCU STREAM OVR THE AREA AND AS PATCHES OF RESIDUAL
LGT CONT UNDR EXITING SHRTWV.

VFR CIGS IS EXPECTED AT ALL PORTS BY LATE MORNING.

.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
RSTRNS ARE LIKELY AGAIN SUN AND MON AS LOW PRES BRINGS A LGT WINTRY
MIX TO THE RGN. VFR SHOULD RTN TUE AND WED UNDER BLDG HIGH PRES.

&&

.HYDROLOGY...
-- Changed Discussion --
A BREAK IN THE PRECIPITATION WILL OCCUR TODAY...BUT ANOTHER STORM
SYSTEM IS PROJECTED TO SPAWN PRECIP ON SUNDAY OVER THE UPPER MONONGAHELA
AND CHEAT BASINS. CRESTS ARE EXPECTED TO REMAIN BELOW FLOOD
STAGES...BUT ACTION LEVELS MAY BE REACHED ALONG THE MONONGAHELA
AND OHIO RIVERS.

SUMMARY: A RIVER RISE OF 5 TO 9 FEET IS COMING TODAY ON THE
MONONGAHELA AND OHIO RIVERS. A SECONDARY RISE IS CURRENTLY
PROJECTED FOR MONDAY. FLOWS AND VELOCITIES WILL REMAIN ELEVATED
INTO TUESDAY.

AREA RIVERS WILL BEGIN TO RECEDE TUESDAY.
-- End Changed Discussion --

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
     NIGHT FOR MDZ001.
OH...NONE.
PA...NONE.
WV...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
     NIGHT FOR WVZ041.

&&

$$