Flood Watch 2, NWS Pittsburgh, PA

092 
WGUS61 KPBZ 081628
FFAPBZ

FLOOD WATCH
NATIONAL WEATHER SERVICE PITTSBURGH PA
1228 PM EDT TUE MAY 8 2012

PAZ007>009-013>016-020>023-073-081730-
/O.CAN.KPBZ.FA.A.0002.000000T0000Z-120508T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MERCER-VENANGO-FOREST-LAWRENCE-BUTLER-CLARION-JEFFERSON PA-BEAVER-
ALLEGHENY-ARMSTRONG-INDIANA-WESTMORELAND-
INCLUDING THE CITIES OF...SHARON...HERMITAGE...GROVE CITY...
GREENVILLE...FARRELL...OIL CITY...FRANKLIN...SUGARCREEK...
TIONESTA...NEW CASTLE...ELLWOOD CITY...BUTLER...ZELIENOPLE...
CLARION...PUNXSUTAWNEY...BROOKVILLE...REYNOLDSVILLE...BROCKWAY...
ALIQUIPPA...BEAVER FALLS...AMBRIDGE...MONACA...BEAVER...
PITTSBURGH METRO AREA...KITTANNING...FORD CITY...LEECHBURG...
FREEPORT...APOLLO...INDIANA...GREENSBURG...NEW KENSINGTON...
JEANNETTE...LATROBE...MONESSEN
1228 PM EDT TUE MAY 8 2012

...FLOOD WATCH IS CANCELLED...

THE FLOOD WATCH FOR PORTIONS OF NORTHWEST PENNSYLVANIA...
SOUTHWEST PENNSYLVANIA AND WEST CENTRAL PENNSYLVANIA HAS BEEN
CANCELLED. 

THE THREAT OF HEAVY RAIN HAS PUSHED EAST OF THE WATCH AREA.
SOME SCATTERED SHOWERS ARE EXPECTED THIS AFTERNOON BUT THE
SHOWERS WILL NOT PRODUCE ENOUGH RAIN TO CAUSE FLOODING.

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
406 AM EDT TUE MAY 8 2012

.SYNOPSIS...
LOW PRESSURE WILL MOVE ACROSS THE GREAT LAKES TODAY...DRAGGING A
COLD FRONT ACROSS THE OHIO VALLEY. THIS WILL CONTINUE TO BRING
SHOWERS AND THUNDERSTORMS THROUGH THE AREA THROUGH THE DAY...WITH
COOLER TEMPERATURES BY MID WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SURFACE FRONTAL BOUNDARY CONTINUES TO BE STRUNG OUT FROM THE
SOUTHERN PLAINS...THROUGH THE MID-MISSISSIPPI VALLEY AND INTO THE
LOWER GREAT LAKES EARLY THIS MORNING. VERY STRONG LOW LEVEL
MOISTURE TRANSPORT EXISTS AHEAD OF THIS FRONT AS EVIDENCED BY
REFLECTIVITIES ON THE REGIONAL RADAR MOSAIC ALL WITH UNIMPRESSIVE
CLOUD TOP TEMPERATURES ON THE IR PRODUCTS. IN FACT...EVEN WHILE
CLOUD TOPS HAVE WARMED...FAIRLY WIDESPREAD MODERATE TO HEAVY
RAINFALL HAS CONTINUED...WHILE THUNDERSTORMS HAVE REALLY BECOME
THE EXCEPTION IN THE FIELD OF HEAVY RAINFALL RATHER THAN THE RULE
AS THEY WERE LAST EVENING. ACTIVITY HAS GENERALLY BEEN FOCUSED
ALONG AND AHEAD OF THIS FRONTAL BOUNDARY OVERNIGHT...BUT AN
ADDITIONAL FOCUS FOR HEAVY RAINFALL LOOKS TO BE COMING INTO VIEW
UPSTREAM EARLY THIS MORNING. A MID-LEVEL WAVE LOOKS TO BE EVIDENT
VIA DRYING ON WATER VAPOR IMAGERY ACROSS SOUTHERN ILLINOIS THIS
MORNING. AHEAD OF THIS WAVE...AN AREA OF PRESSURE FALLS HAS
MANAGED TO FORM A KINK IN THE FRONTAL BOUNDARY AND A LOCAL SURFACE
PRESSURE MINIMA SOUTH OF CINCINNATI. AHEAD OF THIS...LOW LEVEL
SOUTHERLY MOISTURE FLUX LOOKS TO BE MAXIMIZED AS LOW LEVEL FLOW
LOOKS TO BE FOCUSING THETA-E TRANSPORT AT 850 MB INTO EASTERN
KENTUCKY AT THIS TIME. WITH THE COMBINATION OF STRONG MOISTURE
TRANSPORT AND LOW LEVEL CONVERGENCE ON THE NOSE OF THE 850 MB
JET...HEAVY RAINFALL HAS DEVELOPED OVERNIGHT IN THIS AREA. THE
MODEL CONSENSUS TRACKS THIS MID-LEVEL VORTICITY MAXIMA AS WELL AS
LOW LEVEL JET NOSE AND THETA-E TONGUE TOWARD THE SOUTHEASTERN
PORTIONS OF THE CWA THROUGH THE MORNING HOURS TODAY. AS A
RESULT...FAIRLY COPIOUS RAINFALL WILL BE LIKELY EVERYWHERE AHEAD
OF WHERE THE BAND OF CONVECTIVE RAINFALL ADVANCED OVERNIGHT. THIS
LOOKS TO BASICALLY INCLUDE THE AREA FROM INDIANA COUNTY TOWARD
PITTSBURGH AND SOUTHEASTERN OHIO. IN THESE AREAS...IT SEEMS LIKELY
GIVEN THE SETUP AND MODEL CONSENSUS QPF THAT MOST AREAS WILL SEE
AT LEAST THREE QUARTERS OF AN INCH OF ADDITIONAL RAINFALL...WITH
LOCALLY AN ADDITIONAL 1.5 INCHES OF RAINFALL. WHILE THESE NUMBERS
ARE FAIRLY IMPRESSIVE...THE RAINFALL THIS MORNING WILL NOT BE
FOCUSED OVER THE AREAS THAT RECEIVED SIGNIFICANT RAINFALL LAST
EVENING...IT SHOULD BE RATHER TRANSIENT...IS FALLING OVER AN AREA
THAT HAS BEEN FAIRLY DRY RECENTLY...AND REALLY DOES NOT EVEN MEET
FLASH FLOOD GUIDANCE...SO WHILE SOME LOCAL PONDING IS
POSSIBLE/LIKELY...IT SEEMS RATHER UNLIKELY THAT FLASH FLOODING
WILL BE AN ISSUE. AS A RESULT...NO HEADLINES FOR FLASH FLOODING
WILL BE CARRIED FOR ANY ZONES THIS MORNING.

THE BOUNDARY SLOWLY TRUDGES EASTWARD THROUGH THE DAY...AND THE LOW
LEVEL JET NOSE EDGES EAST OF THE CWA BY AFTERNOON. AS A
RESULT...RAINFALL RATES AND POPS TREND DOWN BY AFTERNOON. IN
FACT...SOME COLUMN DRYING IS EVIDENT BY THE AFTERNOON OVER THE
NORTHWESTERN ZONES...SO SOME BREAKS MAY BE POSSIBLE IN THE CLOUDS
BY THAT TIME. HOWEVER...GIVEN THE SLOW FRONTAL PROGRESSION AND
RAINFALL...TEMPERATURES ARE LIKELY TO REMAIN RATHER SUBDUED
THROUGH THE AFTERNOON. FRIES

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE COLD FRONT FINALLY MANAGES TO PUSH SOUTHEAST OF THE AREA
TONIGHT WITH SOME DRIER AIR ALOFT MOVING INTO THE AREA. AS A
RESULT...SHOWERS SHOULD END EVERYWHERE...HOWEVER GIVEN RECENT
RAINFALL...AREAS OF FOG SEEM RATHER LIKELY.

WITH THE PASSAGE OF THE FRONT...UPPER LEVEL TROUGHING LOOKS SET TO
SETTLE INTO THE REGION BY WEDNESDAY. AS THIS OCCURS...TEMPERATURES
ALOFT LOOK TO DIVE RATHER ABRUPTLY BY WEDNESDAY. WITH A MUCH MORE
UNSTABLE PROFILE AND STEEPER MID-LEVEL LAPSE RATES...SHOWERS WILL
BE POSSIBLE ON WEDNESDAY...HOWEVER GIVEN THAT INSTABILITY FAILS TO
REACH MUCH INTO THE BEST THERMAL LAYER FOR CHARGE
SEPARATION...THUNDERSTORMS CONTINUE TO LOOK RATHER UNLIKELY.

THE TROUGH AXIS SHIFTS TO THE EAST OF THE AREA ON WEDNESDAY
NIGHT...WITH COLDER NORTHWESTERLY FLOW REMAINING OVER THE AREA. AS
THE NEXT RIDGE AXIS MOVES TOWARD THE AREA...COLDER HIGH PRESSURE
SETTLES IN FOR THURSDAY. THE NET RESULT WILL BE CLEAR SKIES TO END
THE WEEK...AND WITH HIGH PRESSURE AND COLDER AIR IN CONTROL OF THE
AREA...THURSDAY NIGHT LOOKS FAIRLY COLD. IT WOULD NOT BE
SURPRISING TO SEE SOME AREAS EXPERIENCE A FROST OR EVEN A LOCAL
FREEZE BY THIS TIME. FRIES

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL OF WEATHER FROM THURSDAY
NIGHT THROUGH SATURDAY NIGHT...BEFORE A COLD FRONT MOVES ACROSS
THE GREAT LAKES. THE FRONT SHOULD SLOWLY PASS THROUGH SUNDAY AND
SUNDAY NIGHT...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS.
STILL UNSURE AS TO WHETHER THE FRONT WILL HANG UP IN THE REGION
INTO MONDAY...WHICH COULD ALLOW FOR A CONTINUED CHANCE OF SHOWERS.
TEMPERATURES SHOULD BE NEAR NORMAL.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
PREVAILING CONDITIONS WILL LOWER TO MVFR/IFR WITH SHOWERS
CONTINUING. STORM THREAT IS DECREASING, WILL MENTION TSRA IN TEMPO
GROUPS FOR EARLY PART OF FORECAST. LATEST MODEL RUNS SHOWING AN
IFR/TO LOW MVFR CLOUD DECK THAT WILL MOVE INTO THE AREA AROUND DAWN.
HAVE PERSISTED WITH REDUCED CONDITION FORECAST INTO THE AFTERNOON
HOURS AS MODELS CONTINUE TO INDICATE SLOW PASSAGE OF THE LOW PRES
SYSTEM AND THE ASSOCIATED COLD FRONT.  IMPROVEMENT CAN BE
ANTICIPATED LATE THIS AFTN AND INTO THE EVENING.

.OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
RESTRICTIONS IN PRECIPITATION AND FOG WILL AGAIN DEVELOP ON WED AS
AN UPPER TROUGH SLOWLY CROSSES THE OHIO VALLEY. CONDITIONS SHOULD
IMPROVE TO VFR FOR THURSDAY...FRIDAY...AND SATURDAY AS DRY
SURFACE HIGH PRESSURE BUILD FROM THE WEST.

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
328 AM EDT TUE MAY 8 2012

MDZ001-OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>023-
029-031-073>076-WVZ001>004-012-021>023-041-090930-
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-
328 AM EDT TUE MAY 8 2012

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.

A COLD FRONT WILL BRING SHOWERS WITH LOCALLY HEAVY RAINFALL
CONTINUING THROUGH THE MORNING HOURS. SOME ADDITIONAL PONDING OF
WATER ON ROADS AND STANDING WATER POOR DRAINAGE AREAS WILL
CONTINUE TO BE POSSIBLE THROUGH THE MORNING. IF HEAVY RAIN
PERSISTS IN THE SAME AREA FOR SEVERAL HOURS...STREAM FLOODING
COULD RESULT.

.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.