000
FGUS71 KPBZ 141154
ESFPBZ
MDC023-OHC013-019-029-031-059-067-081-111-119-121-157-PAC003-005-
007-019-031-051-053-059-063-065-073-085-121-125-129-WVC009-029-
049-051-061-069-077-093-103-281200-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE PITTSBURGH PA
754 AM EDT THU MAR 14 2013

 ...FLOOD POTENTIAL IS EXPECTED TO BE NEAR NORMAL...

THE FLOOD POTENTIAL FOR THE PITTSBURGH HYDROLOGICAL SERVICE AREA IS
NEAR NORMAL THROUGH MARCH 28. NORMAL FLOOD POTENTIAL MEANS AT
LEAST MINOR FLOODING IS POSSIBLE.

FOR THE LONG-RANGE RIVER OUTLOOKS AND THE PROBABILITY OF
EXCEEDING FLOOD STAGE OR THE CHANCES OF FLOODING RELATIVE TO
NORMAL AT SPECIFIC FORECAST POINTS DURING THE NEXT 90-DAYS...
REFER TO WWW.WEATHER.GOV/OHRFC AND CLICK ON THE 90-DAY RIVER
OUTLOOK IN THE LEFT HAND COLUMN. CLICK ON FLOOD CHC VS. NORMAL TO
SEE THE RISK OF FLOODING WITH RESPECT TO NORMAL.

FLOOD OUTLOOKS ARE ISSUED BI-WEEKLY BY THE NATIONAL WEATHER
SERVICE DURING WINTER AND EARLY SPRING TO SUMMARIZE BASIN
HYDROMETEROLOGICAL CONDITIONS AND TO ASSESS THE POTENTIAL FOR
WINTER/SPRING FLOODING. THE OUTLOOKS ARE BASED ON CURRENT AND
EXPECTED CONDITIONS ACKNOWLEDGING THAT ACTUAL CONDITIONS COULD
CHANGE DURING THE OUTLOOK PERIOD.

IN ADDITION...90-DAY WATER RESOURCES OUTLOOKS ARE ISSUED MONTHLY.
FACTORS CONSIDERED IN ASSESSING FLOOD POTENTIAL ARE...

ANTECEDENT CONDITIONS

PAST PRECIPITATION 
OVER THE PAST 30 DAYS...PRECIPITATION HAS BEEN 40% TO 50% OF
NORMAL IN ALLEGHENY RIVER BASIN...50% TO 75% OVER THE MONONGAHELA
AND CHEAT RIVER BASINS AND 75% TO 100% ACROSS THE UPPER OHIO AND
100% TO 130% ACROSS THE MUSKINGUM BASINS.

OVER THE PAST 60 DAYS...PRECIPITATION HAS BEEN 50% TO 75% OF
NORMAL IN ALLEGHENY RIVER BASIN...75% TO 125% OVER THE
MONONGAHELA... CHEAT...UPPER OHIO AND MUSKINGUM RIVER BASINS.

OVER THE PAST 90 DAYS...PRECIPITATION HAS BEEN 50 TO 75 OF NORMAL
IN ALLEGHENY RIVER BASIN...95% TO 125% OVER THE MONONGAHELA AND
CHEAT RIVER...AND 100% TO 125% OVER THE UPPER OHIO AND MUSKINGUM
BASINS.

SOILS ARE CURRENTLY MOIST TO WET ACROSS MUCH OF THE REGION DUE TO
CONSISTENT LIGHT TO MODERATE PRECIPITATION ACROSS THE REGION.
 
SEVERAL WARM SPELLS HAVE MELTED MUCH OF THE SNOW COVER ACROSS THE
AREA EXCEPT FOR ELEVATIONS ABOVE 2500 FEET. SNOW WATER EQUIVALENTS
ARE HIGHEST IN THE MOUNTAINOUS TERRAIN OF THE UPPER MONONGAHELA
AND CHEAT BASINS OF WEST VIRGINIA. AT ELEVATIONS ABOVE 3500
FEET...3 TO 4 INCHES OF WATER EQUIVALENTS EXISTS.

STREAMFLOW CONDITIONS 
STREAM FLOWS FOR THE PAST 30 DAYS ARE CLOSE TO NORMAL FOR THE
AREA.

ICE CONDITIONS 
RIVER ICE IS VIRTUALLY NON EXISTENT OVER THE AREA.

RESERVOIR CAPACITIES
MOST RESERVOIRS IN THE USACE PITTSBURGH DISTRICT WERE GRADUALLY
INCREASING THOUGH MOST ARE STILL USING 11 PERCENT OR LESS OF THEIR
STORAGE CAPACITY. THESE VALUES ARE UP FROM THE PAST TWO WEEKS AS
THE USACE PREPARES FOR SUMMER POOLS. THE RESERVOIRS IN THE HUNTINGDON
USACE DISTRICT ARE AT NORMAL WINTER POOL TO ALERT POOL LEVELS.
THIS IS UNCHANGED HAVE INCREASE OVER THE PAST TWO WEEKS.

WEATHER AND PRECIPITATION OUTLOOK
THE OUTLOOK FOR THE NEXT 2 WEEKS HAS AN ACTIVE STORM TRACK OVER
THE AREA WITH TEMPERATURES AVERAGING BELOW NORMAL FOR THIS TIME
OF THE YEAR. THE WEATHER PATTERN INDICATES FREQUENT BUT
RELATIVELY QUICK MOVING STORMS. FLUCATIONS IN TEMPERATURES WILL
BRING PRECIPTATION IN THE FORM OF BOTH SNOW AND RAIN FOR THE NEXT
2 WEEKS. THE FLOOD POTENTIAL WILL REMAIN NEAR NORMAL.

SUMMARY...
RAINFALL IS THE PRIMARY FACTOR LEADING TO FLOODING. HEAVY OR
EXCESSIVE RAINFALL CAN CAUSE FLOODING ANY TIME OF THE YEAR...EVEN
WHERE THE FLOOD POTENTIAL IS BELOW NORMAL.

THE NEXT WINTER/SPRING FLOOD POTENTIAL OUTLOOK WILL BE ISSUED BY
MARCH 28.


$$