FGUS71 KCTP 211432
ESFCTP
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056>059-063>066-220345-

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1032 AM EDT FRI MAR 21 2008

...WINTER/SPRING FLOOD POTENTIAL OUTLOOK 7...

...INTRODUCTION...

DURING THE WINTER AND SPRING...THE NATIONAL WEATHER SERVICE ISSUES A 
SERIES OF WINTER AND SPRING FLOOD POTENTIAL OUTLOOKS. THESE OUTLOOKS 
ESTIMATE THE POTENTIAL FOR RIVER FLOODING (NOT FLASH FLOODING) 
ACROSS CENTRAL PENNSYLVANIA BASED ON A CURRENT ASSESSMENT OF 
HYDROMETEOROLOGICAL FACTORS WHICH CONTRIBUTE TO RIVER FLOODING.  
ACROSS CENTRAL PENNSYLVANIA...THESE FACTORS INCLUDE RECENT 
PRECIPITATION...SOIL MOISTURE...SNOW COVER AND SNOW WATER 
EQUIVALENT...RIVER ICE...STREAMFLOW...FUTURE WEATHER CONDITIONS AND 
OTHERS. THIS OUTLOOK DOES NOT ADDRESS THE SEVERITY OR EXTENT OF ANY 
FUTURE RIVER FLOODING.

THIS OUTLOOK COVERS THE SUSQUEHANNA RIVER BASIN INCLUDING THE WEST 
BRANCH...JUNIATA...AND MUCH OF THE MIDDLE AND LOWER SUSQUEHANNA 
VALLEY. ALSO COVERED ARE PORTIONS OF THE UPPER AND LOWER ALLEGHENY 
BASINS...INCLUDING AREAS FROM WARREN AND MCKEAN COUNTIES IN THE 
NORTH...THROUGH CAMBRIA AND SOMERSET COUNTIES IN THE SOUTH.

THIS OUTLOOK IS VALID FROM FRIDAY MARCH 21ST THROUGH FRIDAY MARCH 
28TH 2008...AND IS PARTIALLY BASED ON THE LATEST NATIONAL WEATHER 
SERVICE MEDIUM RANGE WEATHER FORECASTS. THESE FORECASTS SUGGEST THAT 
TEMPERATURES WILL BE BELOW NORMAL...AND PRECIPITATION WILL BE NEAR 
TO SLIGHTLY BELOW NORMAL ACROSS THE REGION OVER THE NEXT WEEK. 
PLEASE VISIT WWW.CPC.NCEP.NOAA.GOV/ TO VIEW MEDIUM AND LONG-RANGE 
WEATHER OUTLOOKS.

IN CENTRAL PENNSYLVANIA...HEAVY RAINFALL IS THE PRIMARY FACTOR WHICH 
LEADS TO RIVER FLOODING. IT IS IMPORTANT TO NOTE THAT HEAVY RAINFALL 
CAN RAPIDLY CAUSE RIVER FLOODING ANY TIME OF THE YEAR...EVEN WHEN 
OVERALL RIVER FLOOD POTENTIAL IS CONSIDERED LOW OR BELOW AVERAGE.  

...DETAILED DISCUSSION...

...CURRENT RIVER FLOOD POTENTIAL...SOMEWHAT ABOVE AVERAGE.
THE OVERALL POTENTIAL FOR RIVER FLOODING DURING THE NEXT WEEK IS 
CONSIDERED SOMEWHAT ABOVE NORMAL ACROSS CENTRAL PENNSYLVANIA.

...CURRENT FLOODING...NONE.
NO RIVER FLOODING IS OCCURRING ALONG AREA RIVERS AT THIS TIME. A FEW 
POINTS ON THE WEST BRANCH OF THE SUSQUEHANNA ARE CURRENTLY AT OR 
ABOVE THEIR CAUTION STAGES...AND A FEW POINTS ON THE MAIN STEM 
SUSQUEHANNA MAY APPROACH THEIR CAUTION STAGES IN THE NEXT DAY OR 
TWO...BUT NONE ARE FLOODING. 

...RECENT PRECIPITATION...ABOVE AVERAGE.
PRECIPITATION OVER ALL OF CENTRAL PENNSYLVANIA...INCLUDING THE 
SUSQUEHANNA BASIN COVERED BY THE STATE COLLEGE HYDROLOGIC SERVICE 
AREA (HSA) DURING THE LAST 30 DAYS WAS ABOVE NORMAL. ALONG THE 
MIDDLE AND LOWER SUSQUEHANNA BASINS AS WELL AS MOST OF THE JUNIATA 
BASIN...RAINFALL WAS MORE THAN 75 PERCENT ABOVE NORMAL...WITH SOME 
LOCATIONS ALONG THE WEST BRANCH SUSQUEHANNA RECEIVING MORE THAN 
TWICE THE NORMAL PRECIPITATION OVER THE LAST 30 DAYS. PLEASE VISIT 
WWW.ERH.NOAA.GOV/ER/MARFC TO VIEW PRECIPITATION DEPARTURE MAPS.

...SNOW CONDITIONS...BELOW AVERAGE TO AVERAGE.
SNOW COVER IS LIMITED TO THE NORTHERN QUARTER OF THE STATE COLLEGE 
HSA...WITH SNOW AMOUNTS GENERALLY IN THE 2 TO 4 INCH RANGE. 
HOWEVER...HIGHER AMOUNTS OF OVER A FOOT STILL EXIST ON THE HIGHER 
RIDGES OF THE HEADWATERS OF THE ALLEGHENY BASIN AND NORTHERN BASINS 
OF THE WEST BRANCH OF THE SUSQUEHANNA. MOST OF THE MIDDLE AND LOWER 
SUSQUEHANNA BASIN...AND THE JUNIATA BASIN ARE FREE OF SNOW.

WATER EQUIVALENTS ARE NEAR ZERO FOR THE MIDDLE AND LOWER SUSQUEHANNA 
BASIN...AS WELL AS THE JUNIATA BASIN. BETWEEN ONE HALF AND 2 INCHES 
OF WATER EQUIVALENT WAS OBSERVED ACROSS THE UPPER ALLEGHENY BASIN 
AND NORTHERN BASINS OF THE WEST BRANCH OF THE SUSQUEHANNA. SNOW DATA 
AND INFORMATION SOURCES INCLUDE THE NOAA/NWS NATIONAL OPERATIONAL 
HYDROLOGIC REMOTE SENSING CENTER 
(WWW.NOHRSC.NOAA.GOV)...THE U.S. ARMY CORPS OF ENGINEERS...NWS 
COOPERATIVE OBSERVERS...THE COMMUNITY COLLABORATIVE RAIN, HAIL AND 
SNOW NETWORK (COCORAHS)...AND OTHERS. 
BASIN-AVERAGE WATER EQUIVALENT ESTIMATES CAN BE VIEWED AT 
WWW.ERH.NOAA.GOV/ER/MARFC.

...RIVER ICE...AVERAGE.
CURRENTLY...THERE IS NO ICE IN AREA RIVERS AND STREAMS. THIS IS 
FAIRLY NORMAL FOR THIS TIME OF YEAR.

...STREAMFLOW CONDITIONS...AVERAGE TO ABOVE AVERAGE.
STREAMFLOW CONDITIONS ACROSS MOST OF THE SUSQUEHANNA AND ALLEGHENY 
BASINS ARE AVERAGE OR ABOVE AVERAGE FOR THIS TIME OF YEAR. A FEW 
POINTS ON THE WEST BRANCH OF THE SUSQUEHANNA ARE CURRENTLY AT OR 
ABOVE THEIR CAUTION STAGES...AND A FEW POINTS ON THE MAIN STEM 
SUSQUEHANNA MAY APPROACH THEIR CAUTION STAGES IN THE NEXT DAY OR 
TWO...BUT NONE ARE FLOODING. LOCATIONS IN THE JUNIATA BASIN AND THE 
LOWER MAIN STEM SUSQUEHANNA TRIBUTARIES ARE NEAR NORMAL. REAL TIME 
WATER DATA IS AVAILABLE FROM THE UNITED STATES GEOLOGICAL SURVEY BY 
VISITING HTTP://WATER.USGS.GOV ON THE INTERNET.

...SOIL MOISTURE CONDITIONS...MUCH ABOVE AVERAGE.
THE LATEST PALMER DROUGHT SEVERITY INDEX CHART IMPLIES THAT SOIL 
MOISTURE CONDITIONS WERE CLASSIFIED AS VERY MOIST OR EXTREMELY MOIST 
OVER ALMOST ALL OF PENNSYLVANIA...INCLUDING THE ALLEGHENY...WEST 
BRANCH SUSQUEHANNA...JUNIATA AND MAIN STEM SUSQUEHANNA BASINS. SOIL 
MOISTURE MONITORING CHARTS FROM NOAA'S CLIMATE PREDICTION CENTER CAN 
BE FOUND AT 
WWW.CPC.NCEP.NOAA.GOV/SOILMST/ AND WWW.DROUGHT.GOV.

...GROUND WATER...ABOVE AVERAGE.
MONITORING WELLS INDICATE THAT CURRENT GROUND WATER LEVELS ARE
ALL ABOVE AVERAGE ACROSS CENTRAL PENNSYLVANIA. CURRENT GROUND
WATER CONDITIONS BASED ON A 30 DAY MOVING AVERAGE CAN BE FOUND AT
HTTP://PA.WATER.USGS.GOV/MONITOR/GW/INDEX.HTML

...RESERVOIR CONDITIONS...ABOVE AVERAGE.
MOST WATER SUPPLY RESERVOIRS WITHIN CENTRAL PENNSYLVANIA ARE HOLDING 
AVERAGE OR ABOVE AVERAGE STORAGES FOR THIS TIME OF YEAR...AS ARE 
MOST FLOOD CONTROL RESERVOIRS.

...FUTURE WEATHER CONDITIONS...
THE NEXT FEW DAYS WILL BE WELL BELOW NORMAL ON TEMPERATURE...WITH 
SOME SNOWFALL EXPECTED THIS WEEKEND IN THE ALLEGHENY BASINS AND 
UPPER PORTIONS OF THE WEST BRANCH...SUSQUEHANNA AND JUNIATA BASINS. 
FLURRIES ARE THEN EXPECTED FOR EARLY NEXT WEEK. THE NEXT SIGNIFICANT 
RAINFALL IS NOT EXPECTED UNTIL TUESDAY OR WEDNESDAY...WHEN A SYSTEM 
WILL PASS TO THE NORTH OF THE REGION...ALLOWING WARMER AIR AND SOME 
RAIN SHOWERS TO MOVE THROUGH. ANOTHER RAIN-BEARING SYSTEM IS 
EXPECTED TO AFFECT THE REGION AT THE END OF THE WORK WEEK. 

THE 6 TO 10 DAY OUTLOOK...COVERING THE PERIOD FROM MARCH 26TH TO 
MARCH 30TH...CALLS FOR BELOW NORMAL TEMPERATURES AND NEAR NORMAL 
PRECIPITATION. 

THE 8 TO 14 DAY OUTLOOK...COVERING THE PERIOD FROM MARCH 28TH  
THROUGH APRIL 3RD...ALSO CALLS FOR BELOW TEMPERATURES BUT FOR NEAR 
TO SLIGHTLY BELOW NORMAL PRECIPITATION.

...ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/...AVERAGE. 
ANOTHER TOOL USED TO ASSESS THE POTENTIAL FOR RIVER FLOODING IS THE 
ADVANCED HYDROLOGIC PREDICTION SERVICE...AHPS. AHPS GENERATES 
PROBABILISTIC RIVER FORECASTS BASED ON CURRENT BASIN 
CONDITIONS...INCLUDING RIVER LEVELS...SOIL MOISTURE...EXTENT AND 
CONDITION OF ANY SNOWPACK...ALONG WITH 50 YEARS OF HISTORIC 
TEMPERATURE AND PRECIPITATION DATA. 

FOR THIS OUTLOOK PERIOD...AHPS INDICATES THAT THE LIKELIHOOD OF 
RIVER FLOODING IS NEAR NORMAL ACROSS THE REGION. IT SHOULD BE NOTED 
THAT THIS TIME OF YEAR...MID-MARCH INTO EARLY APRIL...IS THE MOST 
FLOOD-PRONE TIME OF YEAR.  IN OTHER WORDS...HISTORY SHOWS THAT 
FLOODING IS A COMMON OCCURRENCE DURING THIS TIME OF YEAR FOR THE 
STATE COLLEGE HYDROLOGIC SERVICE AREA.

REMEMBER...HEAVY RAINFALL CAN RESULT IN FLOODING ANYWHERE WITHIN THE 
REGION...EVEN WHEN OVERALL RIVER FLOOD POTENTIAL IS CONSIDERED TO BE 
LOW OR BELOW AVERAGE.  PLEASE VISIT WWW.WEATHER.GOV/AHPS/ FOR 
DETAILED AHPS INFORMATION.

...SUMMARY...
THE RIVER FLOOD POTENTIAL FOR THE NEXT WEEK IS CONSIDERED SOMEWHAT 
ABOVE AVERAGE. NORMAL TO HIGH STREAMFLOWS...WET SOILS AND RECENT 
PRECIPITATION ALL CONTRIBUTE TO THE HIGHER FLOOD POTENTIAL. 
HOWEVER...THESE FACTORS ARE OFFSET SOMEWHAT BY AVERAGE TO BELOW 
AVERAGE SNOW AND ICE CONDITIONS. HEAVY RAIN WOULD STILL BE REQUIRED 
FOR WIDESPREAD RIVER FLOODING TO DEVELOP.

THIS IS THE FINAL REGULARLY-SCHEDULED FLOOD POTENTIAL OUTLOOK FOR 
SPRING OF 2008. OTHER OUTLOOKS MAY BE ISSUED IF CONDITIONS WARRANT. 
OTHER HYDROMETEOROLOGICAL INFORMATION CAN BE FOUND BY VISITING THE 
STATE COLLEGE INTERNET HOMEPAGE AT WEATHER.GOV/STATECOLLEGE.

$$

SUMMARY/OVERVIEW OF FLOOD POTENTIAL MARCH 21ST - MARCH 28TH 2008:

CURRENT FLOODING...NONE.
RECENT PRECIPITATION...ABOVE AVERAGE.
SNOW CONDITIONS...BELOW AVERAGE TO AVERAGE. 
RIVER ICE...AVERAGE. 
STREAMFLOW CONDITIONS...AVERAGE TO ABOVE AVERAGE. 
SOIL MOISTURE CONDITIONS...MUCH ABOVE AVERAGE.
GROUND WATER...ABOVE AVERAGE. 
RESERVOIR CONDITIONS...ABOVE AVERAGE. 
AHPS...AVERAGE. 
OVERALL FLOOD POTENTIAL...SOMEWHAT ABOVE AVERAGE.

$$

DANGELO