Weather with Bill Evans
Good Day On This Friday December 1, 2023
A weak wave of low pressure impacts the region late today through
tonight. Low pressure moving toward the Great Lakes on Sunday will weaken,
with a secondary low forming south of Long Island Sunday evening and
moving east into the Atlantic later Sunday night into Monday. High
pressure will return for Monday and Tuesday. Low pressure will then
form off the southern Mid Atlantic coast and move out to sea on
Wednesday, followed by building high pressure on Thursday.
The day begins with weak high pressure in place, which should hold
off any rainfall during the morning with maybe an exception towards
noon well north and west as lift is enhanced here with the passage
of an upper jet streak. Rain otherwise becomes likely generally west
to east late in the day into tonight as isentropic lift and mid-
level shortwave energy shift through. Mid-levels dry out late
tonight with still some lower level lift potentially producing some
drizzle with the remnant low level moisture. Models have trended
weaker regarding wind speeds at the base of a low level inversion
late tonight, so with not as high of a chance that turbulent mixing
disrupts fog formation, coupled with light and variable surface
winds, have added areas of fog to the forecast.
Low level moisture becomes even more shallow on Saturday along with
weaker lift. Have therefore gone with a dry forecast outside of any
potential drizzle very early on. Remaining mostly cloudy however,
but temperatures will still be above normal in the mid 50s. The next
area of low pressure approaches from the south during Saturday
night. Rain becomes likely for mainly southern areas after midnight.
Temperatures remaining above normal with cloudy conditions.
Rain expected for Sunday into Sunday night as primary low pressure
weakens to the west and a new center forms just south of Long Island
Sunday evening. Cyclonic low level flow in its wake as the low moves
well out to sea should maintain a fair amount of clouds for Mon in
its wake, along with a gusty W wind. Both days should feature temps
a few degrees above normal, with colder wx returning Mon night and
beyond as a weak secondary cold front moves through.
Mostly dry wx forecast from that point on. A digging nrn stream
shortwave trough should initiate Miller B type cyclogenesis E of
Hatteras on Wed with the global models showing the low moving due E
out to sea, but this situation bears some watching as it could be
less progressive than forecast as previously noted given model
tendency to underdo western Atlantic ridging downstream of the
digging trough, also presence of some ridging aloft near Greenland
and a 50/50 upper low, all of which might allow the low to get close
enough for its precip shield to graze the coast before exiting.
Forecast carries slight chance PoP for snow/rain showers on land and
chance PoP just offshore.
High pressure is then progged to build in for later in the week.
SCA conditions on the ocean are expected to end by 6 AM early this
morning, followed by an extended period of sub-advisory conditions
through at least Sunday as winds become lighter. There could be a
brief period Saturday afternoon where a swell builds to 5 ft on the
eastern ocean waters, but not anticipating the need for an advisory
just yet.
A period of SCA cond expected for the ocean waters from Sunday night
into Tue AM, with W flow gusting to 25 kt and seas building to 5-6
ft in the wake of departing low pressure, then shifting NW with
passage of a secondary cold front with gusts increasing to 30 kt and
seas to 5-7 ft. SCA cond likely on the non ocean waters Mon night
following this fropa as well, with NW flow gusting to 25 kt.
No hydrologic impacts expected with today/tonight`s rainfall. Rainfall
of about 3/4 inch expected Sunday into Sunday night. Light to moderate
intensity and long duration preclude any issues.
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