Flood Potential Outlook
Issued by NWS Mt. Holly, NJ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
000
FGUS71 KPHI 122057
ESFPHI
DEC001-003-005-MDC011-015-029-035-041-NJC001-005-007-009-011-015-
019-021-023-025-027-029-033-035-037-041-PAC011-017-025-029-045-
077-089-091-095-101-192130-

WINTER/SPRING FLOOD POTENTIAL OUTLOOK
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
457 PM EDT THU MAR 12 2015

WINTER/SPRING FLOOD POTENTIAL OUTLOOK...NUMBER 6

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.

THIS OUTLOOK DOES NOT ADDRESS THE SEVERITY OR EXTENT OF ANY FUTURE
RIVER FLOODING.

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.

THIS OUTLOOK IS VALID FOR THE ONE-WEEK PERIOD, MARCH 12 TO 19, 2015.

IN THE MOUNT HOLLY, NEW JERSEY HYDROLOGIC SERVICE AREA (HSA), THE
OVERALL RIVER FLOOD POTENTIAL FOR THE NEXT WEEK IS ABOVE NORMAL.

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

CURRENT FLOODING - RARITAN BASIN.

RECENT PRECIPITATION - BELOW NORMAL ACROSS THE MID-DELAWARE, LEHIGH,
SCHUYLKILL, AND PASSAIC BASINS. NORMAL TO ABOVE NORMAL ACROSS THE
RARITAN AND LOWER DELAWARE BASINS. BETWEEN 1.5 AND 4.0 INCHES OF
LIQUID HAVE BEEN RECORDED OVER THE LAST 30 DAYS. PRECIPITATION
DEPARTURE MAPS CAN BE FOUND AT WWW.WEATHER.GOV/MARFC (UNDER THE
WATER SUPPLY TAB).

SNOW COVER - ABOVE NORMAL NORTH OF ROUTE 80. NORMAL SOUTH OF ROUTE
80. SNOW WATER EQUIVALENTS GENERALLY RANGE BETWEEN ONE AND THREE
INCHES. THESE SNOW CONDITIONS ARE SIGNIFICANT ENOUGH TO BE A FACTOR
IN THE DEVELOPMENT OF RIVER FLOODING, ESPECIALLY IF RAPID SNOWMELT
IS COMBINED WITH SIGNIFICANT RAINFALL. SNOW DEPTH AND BASIN-AVERAGE
WATER EQUIVALENT ESTIMATES CAN BE FOUND AT WWW.WEATHER.GOV/MARFC
(UNDER THE SEASONAL INTEREST TAB) OR WWW.NOHRSC.NOAA.GOV (UNDER THE
NATIONAL ANALYSES TAB).

RIVER ICE - STILL ABOVE NORMAL, BUT MUCH LESS THAN TWO WEEKS AGO.
THAT SAID, NORTHERN AREAS ARE STILL OBSERVING QUITE EXTENSIVE AND
THICK RIVER ICE FOR THIS TIME OF YEAR. SHOULD A RAPID ICE BREAKUP
OCCUR, THE RIVER ICE IS THICK ENOUGH AND EXTENSIVE ENOUGH THAT ICE
JAMS COULD FORM CAUSING LOCALIZED FLOODING.

STREAMFLOW - VARIABLE. BELOW NORMAL NORTH TO ABOVE NORMAL SOUTH.
REAL TIME WATER DATA IS AVAILABLE FROM THE UNITED STATES GEOLOGICAL
SURVEY BY VISITING HTTP://WATER.USGS.GOV.

SOIL MOISTURE - NORMAL TO ABOVE NORMAL. SOIL MOISTURE MONITORING
CHARTS FROM NOAA`S CLIMATE PREDICTION CENTER CAN BE FOUND AT THE
FOLLOWING WEBSITES...
WWW.CPC.NCEP.NOAA.GOV/PRODUCTS/SOILMST_MONITORING/US/SOILMST/SOILMST.
SHTML AS WELL AS WWW.DROUGHT.GOV.

GROUND WATER - USGS MONITORING WELLS INDICATE THAT CURRENT GROUND
WATER LEVELS ACROSS THE REGION ARE VARIABLE, RANGING FROM BELOW
NORMAL TO NORMAL. ADDITIONAL INFORMATION CAN BE FOUND AT
HTTP://GROUNDWATERWATCH.USGS.GOV.

RESERVOIR CONDITIONS - WATER SUPPLY AND FLOOD CONTROL RESERVOIRS IN
THE AREA ARE RUNNING NEAR NORMAL TO NORMAL.

FUTURE WEATHER CONDITIONS - HIGH PRESSURE CURRENTLY OVER OUR REGION
WILL MOVE OFFSHORE ON FRIDAY. LOW PRESSURE IN THE SOUTHERN PLAINS
WILL MOVE NORTHEASTWARD INTO THE OHIO VALLEY ON SATURDAY THEN INTO
NEW ENGLAND ON SUNDAY. BOTH SNOWMELT AND RAINFALL ARE EXPECTED FROM
THE 13TH TO 15TH. HIGH PRESSURE WILL BUILD EASTWARD INTO THE REGION
BEHIND THIS LOW PRESSURE SYSTEM ON MONDAY. BY TUESDAY, A COLD
FRONTAL BOUNDARY WILL MOVE THROUGH THE REGION. ANOTHER HIGH PRESSURE
SYSTEM WILL THEN BUILD EASTWARD INTO THE REGION BY THE MIDDLE OF
NEXT WEEK.

ADVANCED HYDROLOGIC PREDICTION SERVICE (AHPS) - NEAR 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
DELAWARE, PASSAIC AND RARITAN RIVER SYSTEMS. FOURTEEN DAY
PROBABILISTIC FORECASTS GENERATED FOR THESE BASINS SHOW THAT THE
LIKELIHOOD OF FLOODING IS NEAR NORMAL COMPARED TO WHAT HAS BEEN
HISTORICALLY OBSERVED. PLEASE VISIT WWW.WEATHER.GOV/AHPS.

IT SHOULD BE NOTED THAT AHPS PROBABILISTIC FORECASTS DO NOT TAKE INTO
ACCOUNT FUTURE PRECIPITATION.

SUMMARY - TAKING ALL OF THE INCLUDED VARIABLES INTO CONSIDERATION,
THE OVERALL FLOOD POTENTIAL OVER THE NEXT WEEK IS ABOVE NORMAL.

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

$$

SUMMARY/OVERVIEW OF FLOOD POTENTIAL THROUGH MARCH 19, 2015:

OVERALL FLOOD POTENTIAL...ABOVE NORMAL, CENTERED ON THE 14TH-16TH
CURRENT FLOODING...RARITAN BASIN
RECENT PRECIPITATION...BELOW NORMAL TO ABOVE NORMAL
SNOW COVER...NORMAL TO ABOVE NORMAL
RIVER ICE...ABOVE NORMAL
STREAMFLOW...BELOW NORMAL TO ABOVE NORMAL
SOIL MOISTURE...ABOUT NORMAL
GROUND WATER...BELOW NORMAL TO NORMAL
RESERVOIR CONDITIONS...NEAR NORMAL TO NORMAL
AHPS...NEAR NORMAL

$$

KRUZDLO



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.