Flood Potential Outlook
Issued by NWS State College, PA

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WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE STATE COLLEGE PA
215 PM EDT THU MAR 5 2015

...2015 WINTER/SPRING FLOOD POTENTIAL OUTLOOK NUMBER 5...

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 THURSDAY MARCH 5TH 2015 THROUGH THURSDAY
MARCH 19TH 2015.

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.

TWO WEEK RIVER FLOOD POTENTIAL...THE CURRENT POTENTIAL FOR RIVER
FLOODING IS NEAR AVERAGE.

CURRENT FLOODING...NONE
NO ACTIVE FLOODING IS OBSERVED IN THE REGION.

RECENT PRECIPITATION...BELOW AVERAGE. PRECIPITATION WITHIN THE STATE
COLLEGE FORECAST AREA DURING THE LAST 30 DAYS (FEBRUARY 5TH 2015
- MARCH 4TH 2015) IS BELOW AVERAGE ACROSS THE REGION...RANGING FROM
50 TO 90 PERCENT OF AVERAGE.

SNOW CONDITIONS...ABOVE AVERAGE.
SNOW CONDITIONS HAVE CONTINUED TO IMPROVED ACROSS THE AREA.  ALL OF
CENTRAL PENNSYLVANIA REPORTS A SNOW PACK. SNOW DEPTHS ARE DEEPEST
ACROSS NORTHERN PENNSYLVANIA WHERE DEPTHS ARE GENERALLY ABOVE 15
INCHES. ACROSS SOUTHERN PENNSYLVANIA DEPTHS ARE GENERALLY UNDER 5
INCHES...THOUGH DEPTHS WILL INCREASE WITH THE SNOW FALLING THERE
TODAY. SNOW WATER EQUIVALENT VALUES ARE GENERALLY OVER 2.5 INCHES
WHERE THE SNOW IS THE DEEPEST.

SNOW DATA AND INFORMATION SOURCES INCLUDE THE NOAA/NWS
OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER
(WWW.NOHRSC.NOAA.GOV)...THE U.S. ARMY CORPS OF ENGINEERS...NWS
COOPERATIVE OBSERVERS...THE COMMUNITY RAIN, HAIL AND SNOW NETWORK
(COCORAHS) AND OTHERS. SNOW DEPTH AND BASIN AVERAGE WATER
EQUIVALENT ESTIMATES CAN BE SEEN AT WWW.ERH.NOAA.GOV/ER/MARFC
(LOWER CASE) AND WWW.NOHRSC.NOAA.GOV (LOWER CASE).

RIVER ICE...ABOVE AVERAGE. MOST RIVERS AND STREAMS REMAIN AT LEAST
PARTIALLY FROZEN. RECENT RAIN AND BRIEF MILDER TEMPERATURES DID
RESULT IN SOME ICE MOVEMENT AND EVEN A FEW ICE JAMS. WITH THE MILDER
TEMPERATURES IN MARCH...A DECAYING OF THE MAY RESULT IN FURTHER ICE
JAMS GIVEN THE RIGHT CONDITIONS.

FOLLOW RIVER ICE CONDITIONS AT
HTTP://ERH.NOAA.GOV/CTP/HYDRO/RIVERICE/INDEX.PHP (LOWER CASE)

STREAM FLOW CONDITIONS...BELOW AVERAGE.
MOST STREAM FLOWS ARE REPORTING BELOW AVERAGE FLOWS.

REAL TIME WATER DATA IS AVAILABLE FROM THE UNITED STATES
GEOLOGICAL SURVEY BY VISITING HTTP://WATER.USGS.GOV (LOWER CASE)
ON THE INTERNET.

SOIL MOISTURE CONDITIONS...BELOW AVERAGE.
THE LATEST SOIL MOISTURE REPORTS SHOW THAT MOST OF THE REGION IS
REPORTING BELOW AVERAGE MOISTURE VALUES. THE EXCEPTION IS ACROSS
THE SOUTHEAST WHERE AVERAGE VALUES ARE OBSERVED.

MOISTURE MONITORING CHARTS FROM NOAA`S CLIMATE PREDICTION CENTER
CAN BE FOUND AT:
WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/SOILMST_MONITORING/US/SOILMST/SOILMST.SHTML
(LOWER CASE) AND WWW.DROUGHT.GOV.

GROUND WATER...BELOW AVERAGE TO AVERAGE.
MONITORING WELLS INDICATE  THAT CURRENT GROUND WATER LEVELS ARE VARIABLE
WITH NORMAL OR BELOW NORMAL ACROSS PORTIONS OF THE AREA.

CURRENT GROUND WATER CONDITIONS BASED ON A 30 DAY MOVING AVERAGE
CAN BE FOUND AT HTTP://PA.WATER.USGS.GOV/MONITOR/GW/INDEX.HTML
(LOWER CASE)

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

FUTURE WEATHER CONDITIONS.

A SIGNIFICANT CHANGE IN THE WEATHER PATTERNS WILL OCCUR EARLY NEXT
WEEK. WHILE TEMPERATURES WILL REMAIN WELL BELOW AVERAGE INTO THIS
WEEKEND...MUCH MORE MILDER TEMPERATURES ARE FORECAST NEXT WEEK. AT
THIS TIME THERE ARE NO SIGNIFICANT STORM SYSTEMS AND THE OUTLOOK IS
FOR BELOW AVERAGE PRECIPITATION. THIS COULD SET THE STAGE FOR A
NEARLY IDEAL DIURNAL SNOW MELT AND ICE DECAY PATTERN FOR THE STATE.

THE 6 TO 10 DAY OUTLOOK FOR THE PERIOD MARCH 10 - MARCH 14 IS FOR
NEAR AVERAGE TEMPERATURES AND BELOW AVERAGE PRECIPITATION. THE 8 TO
14 DAY OUTLOOK FROM MARCH 12 - MARCH 18 IS FOR AVERAGE TEMPERATURES
AND BELOW AVERAGE 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 SNOW
PACK...ALONG WITH 50 YEARS OF HISTORIC TEMPERATURE AND PRECIPITATION
DATA. FOR THIS OUTLOOK PERIOD... AHPS INDICATES THAT THE LIKELIHOOD
OF RIVER FLOODING IS BELOW AVERAGE COMPARED TO WHAT HAS BEEN
HISTORICALLY OBSERVED DURING THIS SAME TIME PERIOD. RIVER
INFORMATION CAN BE FOUND WEATHER.GOV/AHPS

SUMMARY OF FLOOD POTENTIAL MARCH 5 TO MARCH 19 2015: THE REGIONAL
FLOOD POTENTIAL IS AVERAGE FOR THE NEXT COUPLE OF WEEKS.

OVERVIEW:
CURRENT FLOODING...NONE.
RECENT PRECIPITATION...BELOW AVERAGE.
SNOW CONDITIONS...ABOVE AVERAGE.
RIVER ICE...ABOVE AVERAGE.
STREAM FLOW CONDITIONS...AVERAGE.
SOIL MOISTURE CONDITIONS...BELOW AVERAGE.
GROUND WATER...BELOW AVERAGE TO AVERAGE.
RESERVOIR CONDITIONS...AVERAGE.
AHPS...AVERAGE.
OVERALL  FLOOD POTENTIAL...AVERAGE.

THE NEXT FLOOD POTENTIAL OUTLOOK WILL BE ISSUED ON THURSDAY
MARCH 12TH.

OTHER HYDROMETEOROLOGICAL INFORMATION CAN BE FOUND BY VISITING
THE STATE COLLEGE INTERNET HOMEPAGE AT HTTP://ERH.NOAA.GOV/CTP
(LOWER CASE).

$$

CR



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