Flood Potential Outlook
Issued by NWS Mt. Holly, NJ

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FGUS71 KPHI 182111

Winter/Spring Flood Potential Outlook
National Weather Service Mount Holly NJ
411 PM EST Thu Jan 18 2018

Winter/Spring Flood Potential Outlook...Number 2

This is the second 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 from January 18 to February 1, 2018.

In the Mount Holly, New Jersey Hydrologic Service Area (HSA), the
overall river flood potential is at or below normal.

Note - For the headwaters of the Delaware River, see the statement
(FGUS71 KBGM ESFBGM) from our Binghamton (BGM) New York office.

CURRENT FLOODING - None. Although it is possible that localized
flooding could occur due to ice jams.

RECENT PRECIPITATION - Variable, much below normal to normal.
Between 2.0 and 3.5 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 - With the help of yesterday`s snowfall, snow cover
across the region is normal to above normal. The highest amounts
can be found across the Southern Poconos. Much of the snow is
hydrologically insignificant at this time with water equivalents
less than one inch. 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
Analysis tab).

RIVER ICE - At or above normal. The unusually cold weather from
late December through early January helped to form considerable
river ice. Last week`s milder and wetter weather broke the ice.
As a result, ice jams formed. The few days of milder and wetter
weather was not enough to completely erode the ice. With milder
temperatures and rain expected the next two weeks, additional
melting and movement is expected. Ice jams will remain possible.

STREAMFLOW - Much below normal to below normal. Real time water data
is available from the United States Geological Survey by visiting

SOIL MOISTURE - Normal. Soil moisture monitoring charts (Long Term
Palmer Drought Severity Index) from NOAA`s Climate Prediction Center
can be found at the following websites...
monitoring/palmer.gif 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 above normal. Additonal information can be found at

RESERVOIR CONDITIONS - Water supply and flood control reservoirs in
the area are running below normal to normal.

FUTURE WEATHER CONDITIONS - A broad surface high will build into
much of the eastern U.S. late this week before moving offshore
this weekend. A strong surface low will develop in the central
plains this weekend, lifting northeast into southeast Canada early
next week. This will bring a strong cold front through the area
Monday night and Tuesday. This system should be closely monitored
for it`s potential to cause a period of moderate to heavy
rainfall. High pressure will build back into the region during the
middle of next week. The 8 to 14 day outlook calls for above
normal temperatures and precipitation.

SUMMARY - Taking all of the included variables into consideration,
the overall flood potential is at or below normal.

For complete weather information, visit our website at:



OVERALL FLOOD POTENTIAL...At or below normal
FLOODING...None, although ice jams and isolated flooding is possible
RECENT PRECIPITATION...Variable, much below normal to normal
SNOW COVER...Normal to above normal
RIVER ICE...At or Above normal
STREAMFLOW...Much below normal to below normal
GROUND WATER...Variable, below normal to above normal
RESERVOIR CONDITIONS...Below normal to normal



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