Scientific Forecaster Discussion
fxus61 kphi 180130
Area forecast discussion
National Weather Service Mount Holly New Jersey
930 PM EDT Thu Oct 17 2019
low pressure over New England will continue to move away from the
region tonight and into Friday. High pressure will also start to
build in on Friday and will be overhead on Saturday. By Saturday
night, the high pressure will shift off to the east. An area of low
pressure is expected to track to our south on Sunday and may linger
offshore into Monday. A frontal system is then expected to approach
by the middle of next week.
Near term /until 6 am Friday morning/...
A generally quiet night is expected across the area as winds
calm down a bit (but remain elevated) and clouds thin out. Can't
rule out some light rain/sprinkles across the Poconos as some
weak mid-lvl impulses slide by but generally expect a dry night.
Despite a fairly cool airmass, overnight mins will not be too
cold (generally in the low to mid 40s) on account of the
elevated winds and residual cloud cover (which will be thicker
over the north).
Short term /6 am Friday morning through 6 PM Friday/...
the strong low pressure system will continue lift across the Canadian
Maritimes through Friday, while high pressure approaches from the
west. Winds will remain gusty around 15 to 25 mph, especially early
in the day, but wind speeds will lessen through the day. There also
still remains a slight chance of showers across northeast
Pennsylvania for the first half of the day as some enhance moisture
and lift associated with a couple of short wave/vorticity impulses
slides across the area. However, any precipitation should end by
midday. Otherwise, partly to mostly cloudy skies are expected.
Long term /Friday night through Thursday/...
East Coast ridging will be predominant for most of the next several
days. This will help bring a period of mainly above normal
temperatures from the weekend into the middle of next week. While
earlier indications suggested this stretch may also be entirely dry,
there will be at least one system to watch by later in the weekend
and early next week. This looks like a fairly minor system coming up
from the south, but it will provide some enhanced cloud cover and
possibly some showers by Sunday. This is a minor but complex weather
system, as it is forecast to become a tropical cyclone in the Gulf
of Mexico this weekend before transitioning into an extratropical
low as it moves up the East Coast. Models are struggling to get a
grasp on it, and the forecast for Sunday and Monday is fairly low
confidence. By Tuesday, a stronger frontal system will be
approaching from the west, which should bring unsettled weather
Tuesday or Tuesday night before the cold front comes through. Dry
weather looks to return by the middle to end of next week.
Friday night-Saturday night... dry weather with high pressure in
control. Quite chilly on Friday night, with many areas in the upper
30s to low 40s. If forecast lows come down a couple degrees, may
need to consider frost advisories north and west (for areas where
the growing season has not yet ended). Sunny and seasonable
Saturday. Several degrees warmer Saturday night than Friday night as
southerly flow kicks in.
Sunday-Monday... low pressure tracks up along the southeast coast
during this time. As mentioned, this system may become a tropical
storm in the Gulf of Mexico, but is expected to be Post-tropical and
likely also weakening as it moves up the coast. Current indications
are that the center of this low will stay pretty far to our south.
However, cloudiness and some light showers look possible on Sunday
especially in southern areas. By Monday, mainly dry conditions
appear likely. However, there is some indication that what remains
of the low pressure may still linger offshore into Monday. So cannot
rule out some light showers Monday as well, but nothing significant.
Tuesday-Wednesday... strong low pressure tracks through the far
western Great Lakes early next week and will shift off into Ontario
by the middle of the week. While the center will remain far from US,
the associated cold front should arrive by late Tuesday or early
Wednesday. When this comes through, it should bring a band of steady
rain or showers, but looks to be progressive and will help kick out
to sea any remnant low that remains offshore. High pressure and dry
weather is likely to build in later next week.
Aviation /01z Friday through Tuesday/...
the following discussion is for kphl, kpne, kttn, kabe, krdg, kilg,
kmiv, kacy and surrounding areas.
Tonight...VFR conditions will prevail tonight. Westerly winds
will decrease into the 10-15 kt range after about 03-04z with
any gusts generally around 20 kts.
Friday...VFR conditions will continue through Friday. West to
northwest winds will gust around 15 to 25 knots through the day, but
will diminish through the afternoon.
Friday night-Saturday night... VFR. Light northwest winds on Friday
night gradually becoming light southwesterly on Saturday and light
southeasterly by Saturday night.
Sunday-Sunday night... mainly VFR, with a chance of showers and
potentially MVFR conditions especially near miv and Acy. Easterly
winds around 5 to 10 kt on Sunday will become northeasterly at 5 to
10 kt overnight, with stronger winds possible near the coast.
Monday-Tuesday... mainly VFR. Northeast wind becoming easterly then
southeasterly at 5 to 10 kt on Monday into Monday night. Winds
turning southerly to southwesterly by Tuesday at around 10 kt.
tonight...winds are decreasing across the area however gusts
around 35 kts are still being observed near/along the waters.
Consequently will leave Gale Warning up until 4am although winds
could potentially drop below gale-force a bit sooner.
Friday...Small Craft Advisory conditions are expected to replace
gale force conditions by early morning and continue through the
Friday night-Saturday night... no marine headlines are anticipated,
though gusts early Friday night could be near to just above 20 kt.
Sunday-Tuesday... most of Sunday should feature sub-Small Craft Advisory conditions
with slowly increasing seas. By later Sunday and especially Sunday
night and Monday, a period of Small Craft Advisory conditions is possible as an
offshore low increases seas to 4 to 6 ft with northeast winds
gusting 20 to 25 kt. Small Craft Advisory conditions may linger into Tuesday.
Marine...Gale Warning until 4 am EDT Friday for anz430-431-450>455.