892
FXUS61 KOKX 241151
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
751 AM EDT Wed Apr 24 2024
.SYNOPSIS...
A frontal system moves across the region through early this
evening. Strong high pressure then builds in tonight through
Friday. The strong high remains over the area Friday night into
Saturday and will shift to the south Saturday night as low
pressure moves northeast across the upper Great Lakes into
Canada and an associated warm front approaches. The front will
lift through on Sunday but remain nearby to the east early next
week. A cold front will approach on Tuesday.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
Only minor changes were made for current conditions.
A warm front to the southwest, across southeastern Pennsylvania
into southern New Jersey will move through the area early this
morning, and any showers will briefly come to an end. However,
with the surface low and cold front, along the US/Canada border
at 08Z, moving toward the region showers will become possible
until the front moves south of the area early this evening. Low
level moisture will be limited with the cold front as lift and
CAPE and instability increase. With the low levels dry, and an
inverted V sounding, scattered showers could produce some brief
gusty winds. And while a rumble of thunder can not be ruled out
this afternoon as the capping is mixed out, have not included in
the forecast as any thunderstorms will be rather isolated. CAMs
continue to show widely scattered to isolated showers, and
opted to use coverage terminology for the showers to indicate
this.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH FRIDAY/...
High pressure builds into the region from the west/northwest
this evening through Friday, as a high amplitude ridge builds to
the west, as the upper trough remains from eastern Canada to off
shore of the New England coast. A chilly airmass will remain
over the region, and begin to modify Friday. Temperature will be
around 10 degrees below normal tonight through Thursday night,
and around 5 below normal for Friday. With light to near calm
wind Thursday night, and clear conditions, temperatures are
expected to once again fall to near or below freezing across
the inland zones, and additional frost/freeze headlines may be
needed.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Much of this time frame will feature an omega block over the
eastern CONUS, with its western leg over the central states and
multiple shortwaves lifting NE through the Plains states and
upper Great Lakes, its eastern leg over the Canadian Maritimes
and adjacent Atlantic, and an upper ridge over the East. The
first of the shortwaves lifting through the Plains and Great
Lakes will send a warm front toward the area Sat night that
should then lift through on Sunday, with low chance for showers
mainly inland. A warming trend will then follow, with temps well
above normal especially from the NYC metro area north/west,
with highs well into the lower/mid 70s on Sunday and either side
of 80 on Mon. Most of Long Island and S CT should be cooler,
with highs in the 60s, to near 70 on Mon, due to onshore flow
and afternoon sea breezes, also some intrusion of cooler
maritime air from the east depending on the position and
intensity of low pressure developing well to the east over the
Atlantic.
The omega block should start to break down on Tue, with the
upper ridge weakening and a cold front approaching from the
west, bringing the chance for showers and possibly a tstm. Temps
on Tue should continue to be on the mild side, with highs in
the 60s across much of S CT/Long Island, and in the 70s across
the NYC metro area north/west and interior S CT.
Per NBM 50th/75th percentile forecasts, temps early next week have
potential to be a few degrees warmer than fcst, possibly upper 70s
to mid 80s on Mon, and mid 70s to lower 80s on Tue.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A frontal system will approach overnight and move across today.
Strong high pressure will then build in tonight.
Band of light rain with VFR cond will pass east of the NYC
metros early. Concern this afternoon will be for sct convection
developing along a cold front moving through during mid to late
afternoon. Most likely timing for the NYC metros appears to be
19Z-22Z, an hour earlier north/west and an hour later to the
east. Reasonable worst case direct impact at any terminal would
be TSRA with G35-40kt and brief MVFR vsby.
Winds are already starting to veer SW at the NYC metros. Winds
then become W 10-15G20kt this afternoon ahead of the cold front,
and NW 15G20-25kt after fropa late today into this evening. Winds
then veer N and diminish somewhat overnight.
...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of wind shifts with multiple frontal boundaries may vary by 1-
2 hours, especially with the shift to WNW.
There is low chance of a gusty thunderstorm along the cold
front late this afternoon. Most likely timing appears to be
19Z-22Z.
OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY...
Thursday through Saturday: VFR.
Saturday night and Sunday: Mainly VFR. Low chance for showers with
brief MVFR cond.
Detailed information, including hourly TAF wind component
forecasts, can be found at: https:/www.weather.gov/zny/n90-- End Changed Discussion --
&&
.MARINE...
The Coastal Waters Forecast with wave component details becomes
operational later today.
Winds and gusts on the ocean waters were a few knots lower than
forecast early this morning, and updated for current conditions
and short term trends. Otherwise, no changes were made to winds
and seas.
An increasing, and gusty, southerly flow this morning will
reach SCA levels on the ocean waters with building ocean seas
also reaching advisory levels. With the passage of a cold front
late this afternoon and into early this evening winds shift to
the northwest, and with building high pressure, winds and gusts
gradually diminish below advisory levels by late tonight. Ocean
seas will remain elevated into Thursday morning, and then
subside below 5 feet. A SCA remains in effect on the ocean
waters, and was extended to 1000 AM EDT Thursday. With a weak
pressure gradient later Thursday through Friday, with high
pressure in control, winds and seas will remain below advisory
levels across the forecast waters.
Quiet this weekend into early next week with winds/seas below
advisory criteria. S-SW flow up to 15 kt after a warm frontal
passage could briefly push ocean seas up to 4 ft late day Sunday
into Sunday evening. Fog may also become possible Sunday night as
more humid air traverses colder waters.
&&
.FIRE WEATHER...
Relative humidity will be lowering to around 35 percent late
this afternoon into early this evening behind a cold front, with
west to northwest winds gusting as high as 25 MPH. With falling
temperatures this evening relative humidity levels will then
begin to increase. With the front there will be little to no
wetting rain. Elevated fire spread conditions may briefly be
present for NE NJ, portions of the lower Hudson Valley, New York
City, and western Long Island.
Minimum relative humidity will be in the upper teens to around
25 percent Thursday, however, winds will be under 10 MPH.
&&
.HYDROLOGY...
No hydrologic concerns through early next week.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...Freeze Watch from late tonight through Thursday morning for
CTZ005>008.
NY...Freeze Watch from late tonight through Thursday morning for
NYZ067>070.
NJ...Freeze Watch from late tonight through Thursday morning for
NJZ002-103.
MARINE...Small Craft Advisory until 10 AM EDT Thursday for ANZ350-353-
355.
&&
$$
SYNOPSIS...BG/MET
NEAR TERM...MET
SHORT TERM...MET
LONG TERM...BG
AVIATION...BG
MARINE...BG/MET
FIRE WEATHER...
HYDROLOGY...BG/MET