929
FXUS61 KOKX 250821
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
421 AM EDT Fri Oct 25 2024
.SYNOPSIS...
-- Changed Discussion --
High pressure will move across the area today and then give way
to an approaching cold front tonight. The front moves through
during the early morning hours Saturday. Another large area of
high pressure then builds in through early next week. A warm
front will also pass to the north Tuesday into Tuesday night,
allowing for a warming trend to develop.-- End Changed Discussion --
&&
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
High pressure builds across the area today and then offshore by
this evening ahead of a cold front approaching from the Great
Lakes. The front moves through during the early morning hours
Saturday, before daybreak for most locations except perhaps far
eastern LI/SE CT. This is forecast to be a dry frontal passage
due to little forcing and limited moisture. The associated upper
trough amplifies while digging into the Northeast tonight. A
light northerly flow this morning become W/SW this afternoon.
While the area will be under warm advection today as the upper
ridge axis passes to the east, a subsidence inversion will
limit the depth of the mixed layer. This will be the coolest day
of the week. Highs today are forecast to be in the lower to mid
60s, which is slightly above normal.-- End Changed Discussion --
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
-- Changed Discussion --
On the heels of an early morning cold frontal passage Saturday,
cold advection will ensue with gusty NW winds. Gusts up to 30
mph will be possible from late morning into the afternoon.
Leaned toward the NBM 90th percentile for winds based on 00Z
model soundings from the GFS, NAM, and RAP, which all point
toward a stronger vertical wind profile. This will also elevate
the spread of wildfires. See Fire Weather section below.
Highs on Saturday with deeper mixing will actually be warmer
than Friday, but still in the 60s and several degrees above
normal. Cold advection will continue into Saturday night with
overnight lows actually a few degrees below normal. Readings
Sunday morning will range form the mid and upper 30s inland and
the Pine Barrens Region of LI, to the lower and mid 40s elsewhere.
Winds will gradually diminish through the night and any frost looks
to be patchy across the interior. Sunday will be much cooler with
highs in the 50s. Based on model 2m temps and a trend toward
cooler, undercut NBM slightly. This is also close to MET/MAV
MOS. NW winds will be considerably weaker than Saturday.-- End Changed Discussion --
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
Dry weather is expected in the extended as high pres drifts offshore
and an upr ridge builds over the East Coast again. This pattern will
also allow for a warming trend thru the period. Based on model
agreement and the h85 wly wind flow, went abv the NBM for high temps
Wed and Thu. The numbers at this point may still be too low, with
mixing down the GFS producing at least low 80s for the area. The
challenge is always how much the water influences local temps, and
how deep the mixing is, especially with a sly component to the flow.
For these reasons the fcst is warmer than the NBM, but with room for
adjustment based on these other factors. Otherwise, the NBM with
only minor tweaks was used for the rest of the extended period at
this point. However, will need to focus on Sun ngt, as temps may
drop further than the NBM suggests if winds diminish sufficiently.
The MEX is colder and may be better in this scenario.-- End Changed Discussion --
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
High pres over the area today, followed by a cold frontal
passage Sat mrng.
VFR thru the TAF period.
NW-N winds under 10 kt expected this morning before becoming
SW-SSW in the afternoon. Light SW winds tngt, then winds shift
to the NW around 12Z Sat.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shift to the SW-SSW may be off by 1-2 hours
this afternoon.
OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY...
Tonight: Light SW winds becoming NW around 12Z Sat.
Saturday: VFR. NW wind gusts 20-25kt.
Sunday: VFR. NW winds gusts 15-20 kt possible.
Monday-Tuesday: VFR. S wind gusts 15-20 kt possible.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
-- Changed Discussion --
While high pressure builds over the waters today, an ESE swell
will result in seas around 5 ft on the ocean. This could linger
into early this evening, but confidence was too low to extend
the SCA.
A cold front moves through the waters early Saturday morning
with NW gusts strengthening to 20 to 25 kt. Seas look to be
around 4 ft. Blended NWPS seas with the lower Wavewatch as
it has often been too high in offshore flow events. However, a
SCA may still be needed for Saturday, especially during the
afternoon and nighttime hours. Winds and seas will then subside
late Saturday night into Sunday with high pressure building in
from the west.
High pres will keep winds and seas blw sca lvls Mon and Tue. By
early Wed however, increasing swly flow should allow for the
development of SCA conditions on the ocean thru Thu.-- End Changed Discussion --
&&
.FIRE WEATHER...
-- Changed Discussion --
Conditions are expected to be marginally favorable for wildfire
spread on today with min RH less than 40 percent, but winds
won`t be nearly as strong, generally 5 to 10 mph. SPS has been
issued for NE NJ and S CT per earlier collab.
Temps will be cooler this weekend into early next week, but with
min afternoon RH 25-35 percent from Sat into Mon. NW winds may
also gust to 25-30 mph Sat afternoon and early evening, with
meteorological conditions meeting red flag criteria in NE NJ
and in/just outside NYC, and close to it for the rest of area.
Winds will be considerably weaker for Sunday.-- End Changed Discussion --
&&
.HYDROLOGY...
The prolonged stretch of dry weather continues and there are no
hydrologic concerns.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Frost Advisory until 9 AM EDT this morning for NYZ067.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT this evening for ANZ350-
353-355.
&&
$$
SYNOPSIS...JMC/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JMC
AVIATION...JMC
MARINE...JMC/DW
FIRE WEATHER...
HYDROLOGY...JMC/DW