River Flood Warning 9, NWS Pittsburgh, PA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
934 AM EDT TUE MAR 10 2015

.SYNOPSIS...
LOW PRESSURE EMERGING FROM THE SOUTHERN PLAINS WILL SPREAD RAIN
OVER THE REGION TODAY AND TONIGHT. WARMER WEATHER WILL CONTINUE
THROUGH THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPSTREAM HOURLY PRECIPITATION TOTALS LOOK TO BE AROUND 0.05 TO
0.10 ON AVERAGE...UP TO 0.15 ON IN MORE MODERATE RAIN...SO OPTED TO
INCREASE OVERALL QPF AMOUNTS SLIGHTLY THROUGH TODAY...BUT NO OTHER
CHANGES WERE NECESSARY AT THIS TIME. PREV DISCUSSION BELOW..

SXATELLITE AND UPPER AIR ANALYSIS INDICATES SPLIT FLOW OVER THE
CONUS WITH A SHORTWAVE EMERGING FROM A SOUTHERN ROCKIES TROUGH. ON
THE VAN OF THAT DISTURBANCE IS A DECENT MOISTURE PLUME WHICH WILL
FUEL RAIN WITH THE ADVANCE OF THE SYSTEM TOWARD THE UPPER OHIO
REGION TODAY.

FORECAST ADJUSTMENTS...BASED ON A BLEND OF THE LATEST DETERMINISTIC
TRENDS...INCLUDE A PRECIP PROBABILITY ESCALATION TO CATEGORICAL
NUMBERS OVER AREAS FROM PITT SOUTHWARD...WITH LIKELY NUMBERS TO THE
NORTH. DESPITE THE RISING POPS...WITH RELATIVELY WEAK AND
PROGRESSIVE DYNAMICS...RAIN AMOUNTS ARE EXPECTED TO REMAIN ON THE
LIGHT SIDE WITH A TENTH PROJECTED OVER THE I 80 CORRIDOR...ABOUT A
QUARTER INCH BETWEEN I 80 AND I 70...THEN TRENDING TO A HALF INCH
SOUTH OF I 70. THE QUESTION AREA WILL BE THE BASIN OF THE CHEAT
RIVER...ESPECIALLY THE UPPER REACHES OVER TUCKER COUNTY WHERE
TOTALS MAY APPROACH THREE QUARTERS TO AN INCH AS THE SURFACE LOW
CROSSES. FOR THE MORNING ISSUANCE...HAVE FORECAST QPF CLOSE TO RFC
GUIDANCE...WHICH WITH SNOW MELT...SUPPORTS A HEALTHY RISE ON THE
CHEAT AND THE MON...BUT MAINTAINS BANK INTEGRITY.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
EITHER WAY...A TROUGH IN THE NORTHERN STREAM IS PROJECTED TO SHUNT
THE WHOLE SCENARIO EASTWARD BY WEDNESDAY. WEDNESDAY HIGHS WERE
FORECAST A FEW DEGREES ABOVE THE AVERAGES AS COLD ADVECTION WILL
BE LIMITED WITH THE SURFACE HIGH BEING PUSHED OVER NEW ENGLAND IN
RESPONSE TO THE DEEPENING TROUGH OVER THE SOUTHERN PLAINS.

SHORTWAVE RIDGING IN ADVANCE OF THE AFOREMENTIONED MENTIONED
TROUGH SHOULD ENSURE A DRY THURSDAY...WITH CONTINUED SEASONABLY
WARM TEMPS UNDER THE RISING HEIGHTS.

BY FRIDAY...THE SOUTHERN TROUGH IS FORECAST TO EMERGE...HENCE POPS
WERE BUMPED TO LIKELY NUMBERS FOR RAIN BY LATE DAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
THE SOUTHERN TROUGH IS PROGGED TO CONTINUE RAIN THROUGH
SATURDAY...AND LIKELY POPS WERE MAINTAINED. AS THAT WAVE EXITS...
BRIEF TROUGHING ACROSS THE NORTHEASTERN CONUS IS PROGGED TO SET UP
WITH A QUICK SHOT OF COOLER AIR LATE IN THE WEEKEND BEFORE THE
FLOW FLATTENS OUT EARLY NEXT WEEK.

RECENT OPERATIONAL MODELS HAVE COME INTO BETTER AGREEMENT...THOUGH
DIFFERENCES IN STRENGTH AND TIMING OF INDIVIDUAL FEATURES EXIST.
FAVORED THE WPC ENSEMBLE APPROACH FOR THE LONG TERM...BLENDED
WITH THE WARMER GFS AND ECMWF GUIDANCE.

&&

.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
CONDITINS WILL DETERIORATE TO IFR BY THIS AFTERNOON...WITH
NORTHERN PORTS SEEING THE DECREASING TREND THE LATEST. THESE
DIMINISHED CONDITIONS SHOULD PERSIST THROUGH TONIGHT UNTIL SOME
IMPROVEMENT TO LOW MVFR IS SEEN LATE TONIGHT AS THE LOW BEGINS TO
EXIT.

.OUTLOOK.../WEDNESDAY THROUGH SATURDAY/...
RESTRICTIONS WILL PERSIST INTO WEDNESDAY MORNING WITH EXITING LOW
PRESSURE. RESTRICTION POTENTIAL WILL RETURN FRIDAY AND SATURDAY
WITH LOW PRESSURE ACROSS THE OHIO VALLEY.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
320 AM EDT TUE MAR 10 2015

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029-031-073>076-WVZ001>004-012-021>023-041-110730-
GARRETT-TUSCARAWAS-CARROLL-COLUMBIANA-COSHOCTON-HARRISON-
JEFFERSON OH-MUSKINGUM-GUERNSEY-BELMONT-NOBLE-MONROE-MERCER-VENANGO-
FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER-ALLEGHENY-
ARMSTRONG-INDIANA-WASHINGTON-GREENE-WESTMORELAND-WESTMORELAND RIDGES-
FAYETTE-FAYETTE RIDGES-HANCOCK-BROOKE-OHIO-MARSHALL-WETZEL-MARION-
MONONGALIA-PRESTON-TUCKER-
320 AM EDT TUE MAR 10 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN MARYLAND...EAST
CENTRAL OHIO...NORTHWEST PENNSYLVANIA...SOUTHWEST
PENNSYLVANIA...WEST CENTRAL PENNSYLVANIA...NORTHERN WEST VIRGINIA
AND NORTHERN PANHANDLE OF WEST VIRGINIA.

.DAY ONE...TODAY AND TONIGHT.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.