Tonight:
Mostly cloudy, with a low around 26. East wind around 1 mph.
Friday:
Mostly cloudy, with a high near 46. East wind 1 to 6 mph.
Friday Night:
Rain after 10pm. Cloudy, with a low around 35. East wind 7 to 16 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Saturday:
Rain before 7am, then rain and a slight chance of thunderstorms. Some of the storms could produce heavy rain. Cloudy, with a high near 42. Northeast wind 6 to 17 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
Saturday Night:
Rain likely before 10pm. Mostly cloudy, with a low around 31. West wind around 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
Sunday:
Mostly cloudy, with a high near 41.
Sunday Night:
Mostly cloudy, with a low around 32.
Monday:
Partly sunny, with a high near 41.
AREA FORECAST DISCUSSION
National Weather Service Mount Holly NJ
632 PM EST Thu Jan 23 2020
Weather Synopsis:
High pressure will move offshore overnight then nose back down into
the region from the north on Friday. Low pressure will develop
across the Tennessee and Ohio River Valleys and move northeastward
with a secondary area of low pressure developing in the Mid-Atlantic
and impacting the region through early Sunday. As the merging
systems move out to sea by Monday, weak high pressure will
return through the middle of next week. Another system may
impact the region late next week.
Near Term:
UNTIL 6 AM FRIDAY MORNING -
For the 630 PM update...made just minor changes to the
temperature and dewpoint temperature grids to account for
current/recent observations, and made a dew minor adjustments to
the cloud cover and wind grids. Otherwise...previous forecast is
still on track.
...Prev discussion below...
High pressure centered overhead will slowly build eastward
through the the overnight as low pressure slowly works its way
up the Ohio Valley toward the Great Lakes. A building cirrus
shield will continue through the night, thus temperatures should
remain a little warmer than last night as lows drop into the
20s. Winds will remain light and variable as high pressure
dominates, though a weak sea breeze has developed along the
Jersey Shore (what month is it again?).
Short Term:
6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY -
A very similar day in store for Friday as high pressure begins to
fill as it lifts northeast toward the Canadian Maritimes. Low
pressure to our west will continue to occlude as it moves toward the
Great Lakes. Several waves of high clouds will pass the region
through the day as a series of vort maxima eject across the region
from the parent trough to our west. Winds will begin to turn
easterly as the surface high lifts northward and the pressure
gradient tightens ahead of the low to our west. Highs will trend
upward a few degrees into the 40s and 50s as 500 mb heights begin to
nudge upward ahead of the trough to our west.
Long Term:
FRIDAY NIGHT THROUGH THURSDAY -
By midday Friday, a closed upper low will be making its way across
the Mississippi River Valley into the Ohio Valley then eventually
toward the Mid-Atlantic by Saturday. At the surface, a 2 part low
pressure system will be approaching the region from the south and
west. The initial low across the Ohio Valley will weaken then the
secondary low lifting north from the Gulf and across the Carolinas
will become dominant and intensify as it moves up the coast toward
the Mid-Atlantic. This low is forecast to briefly stall out
across the region Saturday night then move slowly offshore on Sunday.
Precipitation is forecast to move in generally from southwest to
northeast early Saturday morning. Can`t rule out a brief period of
sleet across the entire area at precip onset (timing dependent), but
this will be a moderate to heavy rain event for the I-95 corridor
and south/east. From around the Lehigh Valley and north including NW
NJ and the southern Poconos, temperatures will be at or below
freezing as rain (possibly mixed with sleet) moves into the region.
Therefore, expecting a fairly expansive area of freezing rain to
impact these areas through Saturday morning as temperatures slowly
rise above freezing and precip switches to all rain by some time
Saturday afternoon for most. The freezing rain may be moderate to
heavy at times Saturday morning. Expecting up to around 0.25" of ice
accretion with potential for localized higher amounts in the typical
areas that remain below freezing the longest (Mount Pocono, High
Point, etc.). This event has potential to be the most significant
"ice storm" the area has seen so far this season.
The surface low will be tracking directly over the area and warm air
advection will be strong aloft and near the surface. PWats will also
be anomalously high reaching up to 1.25" across Delmarva and
southern NJ. This combined with strong forcing for ascent and
elevated instability in the 100-200 J/kg range will result in a
band of moderate to heavy rain with embedded thunderstorms
(rumbles of thunder). Expect most of the area to get around
1-1.5" of rain total with locally higher amounts of 2"+ where
heavy rain persists longer. With the antecedent dry conditions
and unfrozen ground, not expecting any widespread flooding or
flash flooding concerns, however if 1-2" of rain falls fast
enough localized flooding is certainly possible. Precip will end
fairly abruptly from west to east through the afternoon on
Saturday. Some lingering showers are possible, especially up
north. The low will be exiting the area on Sunday and lingering
showers will diminish up north through the day.
In the wake of the weekend system, high pressure will build slowly
in from the west. Expect temperatures near normal along with fair
weather. Another system may impact the region later next week.
Click for full NWS PHI Office Area Forecast Discussion
