May 22, 2015 May has been quite dry so far with 1/2 inch or less of
rain in east-central and southeast Pennsylvania. New Jersey has seen
mostly 1/2 to 1 inch amounts while southern New York and the rest of
Pennsylvania have picked up generally 1 to scattered areas of as much
as 2 1/2 inches of rain. Except for scattered spots, most of the
southern two thirds of Pennsylvania and all of New Jersey are 1 to 2
1/2 inches below normal. May continues to be quite warm with
temperatures running several degrees above normal. Over the past 60
days, precipitation over the Catskill Region of New York; eastern,
southeastern, and south-central Pennsylvania; and all of New Jersey is
running 25% to more than 50% below normal. Over the past 90 days,
precipitation has been about 1 to 4 1/2 inches below average in
southern New York and Pennsylvania and up to 5 1/2 inches below in
parts of east-central Pennsylvania. Precipitation has been 2 to over
5 inches below in most of New Jersey. The only exception has been
southern New Jersey where precipitation has been near normal. In
summary, the frequency and amount of precipitation has decreased
noticeably over the past couple of months.
Current (May 22) streamflow data from the U.S. Geological Survey
shows that streamflows are much below normal in the Catskill Region of
New York, eastern Pennsylvania, and the northern two thirds of New
Jersey. Elsewhere, flows are below normal. Groundwater levels are
much below normal in eastern Pennsylvania and northwest New Jersey.
Elsewhere, groundwater is near or below normal.
As a result of this recent dryness, according to the US Drought
Monitor, several counties in eastern Pennsylvania, northwest New
Jersey, and southern-most New York are now considered to be in
"Moderate Drought." This means that some damage to crops and pastures
could occur; streams, reservoirs, or wells are low; some water
shortages are developing or are imminent; and voluntary water-use
restrictions may be requested.
The weather outlook into early June calls for below average
rainfall for the first half of the outlook but then near or above
average rainfall for the second half. Temperatures are expected to be
above or much above normal. The NWS Climate Prediction Center's 30 day
outlook for June calls for near average rainfall and near or above
normal temperatures. The 90 day outlook for June through August calls
for near average precipitation and temperatures.
The outlook for water resources and water supplies has been
downgraded and is now good to fair across southern New York and
northern Pennsylvania. The outlook is fair to poor for southern
Pennsylvania and New Jersey. Rainfall frequency and amounts have
decreased considerably over the past 30 to 60 days creating noticeable
deficits. Areas further north have had more rainfall allowing
conditions to remain fairly wet, at least for now. This lack of
rainfall is having an effect on streamflows, topsoil and groundwater.
Further effects may appear as we move further into the warm season and
if rainfall remains below normal. Longer term precipitation deficits
are also growing during this near term lack of rainfall. The outlook
for rainfall suggests a return to at least average or even above
average rain. However, further degrading of this outlook is quite
possible in the event that this rainfall does not materialize.