000
FGUS71 KPHI 201415
ESFPHI
DEZ001>004-MDZ008-012-015-019-020-NJZ001-007>010-012>027-
PAZ054-055-060>062-067>071-212000-

HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1013 AM EDT FRI MAR 20 2009

WINTER/SPRING FLOOD OUTLOOK...NUMBER 6 (FINAL)

THIS IS THE SIXTH IN A SERIES OF ANNUAL WINTER/SPRING FLOOD 
POTENTIAL STATEMENTS INTENDED TO PROVIDE INSIGHT INTO THE LIKELIHOOD 
OF RIVER FLOODING (NOT FLASH FLOODING) OVER THE MIDDLE/LOWER 
DELAWARE, LEHIGH, SCHUYLKILL, PASSAIC AND RARITAN RIVER BASINS. 
THESE STATEMENTS WILL PROVIDE INFORMATION ON FLOOD THREAT CONDITIONS 
SUCH AS RECENT PRECIPITATION, SOIL MOISTURE, SNOW COVER AND ITS 
WATER EQUIVALENT, RIVER ICE CONDITIONS, STREAMFLOW, FUTURE 
PRECIPITATION AND OTHERS.

IN THE MID-ATLANTIC REGION, 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 YEAR, EVEN 
WHEN THE OVERALL RIVER FLOOD POTENTIAL IS CONSIDERED TO BE LOW.

IN THE MOUNT HOLLY, NEW JERSEY HYDROLOGIC SERVICE AREA, THE FLOOD 
POTENTIAL IS BELOW NORMAL FOR THIS TIME OF YEAR.

NOTE - FOR THE HEADWATERS OF THE DELAWARE RIVER, SEE THE STATEMENT 
(FGUS71 KBGM ESFBGM) FROM OUR BINGHAMTON (BGM), NEW YORK OFFICE. 

CURRENT FLOODING - NONE. 

RECENT PRECIPITATION - BELOW TO MUCH BELOW NORMAL, BETWEEN 0.50 AND 
2.0 INCHES, HAS BEEN RECORDED OVER THE LAST 30 DAYS. PRECIPITATION 
DEPARTURE MAPS CAN BE FOUND AT WWW.ERH.NOAA.GOV/ER/MARFC.

SNOW COVER - NORMAL. ONLY PATCHES OF SNOW REMAIN IN THE HIGHER 
ELEVATIONS OF NEW YORK AND IS CONSIDERED HYDROLOGICALLY 
INSIGNIFICANT. SNOW DEPTH AND BASIN-AVERAGE WATER EQUIVALENT 
ESTIMATES CAN BE FOUND AT WWW.ERH.NOAA.GOV/ER/MARFC OR 
WWW.NOHRSC.NOAA.GOV.

RIVER ICE - NORMAL. NO RIVER ICE REMAINS IN OUR HYDROLOGIC SERVICE 
AREA (HSA).

STREAMFLOW - MUCH BELOW NORMAL TO NORMAL. STREAMFLOW IS PRESENTLY 
NORMAL DOWN THE MAINSTEM DELAWARE RIVER DUE TO THE RECENT 
RAIN/SNOWMELT EVENTS ACROSS IT'S HEADWATER REGION. ELSEWHERE, 
STREAMFLOW DROPS OFF RAPIDLY INTO THE BELOW NORMAL OR MUCH BELOW 
NORMAL CATEGORY FOR THIS TIME OF YEAR. REAL TIME WATER DATA IS 
AVAILABLE FROM THE UNITED STATES GEOLOGICAL SURVEY BY VISITING 
HTTP://WATER.USGS.GOV.

SOIL MOISTURE - NEAR NORMAL. 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 - MONITORING WELLS INDICATE THAT CURRENT GROUND WATER 
LEVELS ACROSS THE REGION ARE GENERALLY NORMAL TO ABOVE NORMAL. 

RESERVOIR CONDITIONS - ALL WATER SUPPLY AND FLOOD CONTROL RESERVOIRS 
IN THE AREA ARE NORMAL. 

FUTURE WEATHER CONDITIONS - PRESENTLY, THERE ARE NO STRONG 
INDICATIONS OF ANY HEAVY RAIN EVENTS FOR ABOUT THE NEXT WEEK. IN 
GENERAL, THE NEXT SEVERAL DAYS LOOK RATHER DRY WITH NEAR NORMAL 
TEMPERATURES.  
 
THE 8 TO 14 DAY OUTLOOK CALLS FOR BELOW NORMAL TEMPERATURES AND 
NEAR NORMAL PRECIPITATION.

ADVANCED HYDROLOGIC PREDICTION SERVICE (AHPS) - BELOW NORMAL FOR 
THIS TIME OF YEAR. ANOTHER TOOL USED TO ASSESS THE POTENTIAL FOR 
WINTER/SPRING FLOODING IS CALLED AHPS, ADVANCED HYDROLOGIC 
PREDICTION SERVICE. ONE COMPONENT OF AHPS IS THE GENERATION OF 
PROBABILISTIC RIVER FORECASTS BASED ON CURRENT BASIN CONDITIONS 
(RIVER LEVELS, SOIL MOISTURE, EXTENT AND CONDITION OF SNOWPACK) 
ALONG WITH 50 YEARS OF HISTORIC TEMPERATURE AND PRECIPITATION DATA.

FOR THIS OUTLOOK, THE AHPS TECHNIQUE HAS BEEN APPLIED TO THE 
SUSQUEHANNA, DELAWARE, PASSAIC AND RARITAN RIVER SYSTEMS. FOURTEEN 
DAY PROBABILISTIC FORECASTS GENERATED FOR THESE BASINS SHOW THAT THE 
LIKELIHOOD OF FLOODING IS BELOW NORMAL COMPARED TO WHAT HAS BEEN 
HISTORICALLY OBSERVED. 

SUMMARY - TAKING ALL OF THE INCLUDED VARIABLES INTO CONSIDERATION, 
THE OVERALL WINTER/SPRING FLOOD POTENTIAL IS BELOW NORMAL. 

THIS WILL BE THE FINAL 2009 WINTER/SPRING FLOOD OUTLOOK ISSUED BY 
THIS OFFICE UNLESS CONDITIONS WARRANT A CHANGE.

FOR COMPLETE WEATHER INFORMATION, VISIT OUR WEB SITE AT: 
WWW.WEATHER.GOV/PHI

$$

SUMMARY/OVERVIEW OF FLOOD POTENTIAL THROUGH APRIL 3, 2009:

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

$$

KRUZDLO