Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
706
FXUS61 KOKX 020249
AFDOKX
Area Forecast Discussion
National Weather Service New York NY
1049 PM EDT Thu Oct 1 2026
.WHAT HAS CHANGED...
Updated for Aviation.
&&
.KEY MESSAGES...
1) Cold front approaches Friday, crosses through Friday night.
Above normal temperatures in store for Friday. Chance of
showers afternoon into evening with possible isolated rumble of
thunder.
2) Potential wave of low pressure and associated shower chances
late this weekend.
3) Temperatures overall turning cooler for the weekend into next
week.
&&
.DISCUSSION...
.KEY MESSAGE 1...
Mid level height falls as mid level shortwave moves southeast
into the region for Friday. Mid level flow remains nearly zonal.
At the surface, a cold front approaches from the west Friday. As
it moves through late afternoon into evening, the model
consensus has it weakening as it moves through. With the quick
nearly zonal mid level flow, the front will be quick as will the
showers that accompany it.
The NAM continues to be the most aggressive with its low level
thermodynamics and rainfall with this. GFS on the other hand,
appears to be the most weak of model solutions, with hardly any
rainfall forecast within the local area. The timeframe for the
rain showers is Friday afternoon, mainly in the latter half,
through Friday evening with showers shifting south of Long
Island during the overnight.
There is some instability, but likely under 500 J/kg of surface
CAPE ahead of the front with the low level warm air advection.
In addition to the chance of showers, there is a slight chance
of thunderstorms.
Regarding the low level warm air advection, NBM with its
temperatures sided more with the warmer side of MOS. Feel
potential is there for warmer temperatures given the synoptic
scenario. This scenario is with more low level westerly flow,
with more warm air advection and less maritime influence. Also,
with the lack of strength of the cold front and associated
shortwave, more sun will allow for greater diurnal warmth. The
forecast highs range from the mid 70s to mid 80s, about 10 to
15 degrees above normal.
.KEY MESSAGE 2...
Dry conditions for this weekend will last until Sunday. That is
when potentially another wave of low pressure may get within
close enough proximity to the local region to bring rain
showers. The low will be along the same front that went through
the region a few nights prior and slowed down on its movement
south of the region. Aloft, the mid level heights are lower than
the event a few nights prior and there is a stronger upper level
low north of Great Lakes with this event also.
Over the past few days, there has been some fluctuation between
the position of the front and the associated rain showers. There
are still quite the spread in precipitation forecast amongst the
operational models with the ECMWF showing rain across the entire
region and potentially around a quarter of an inch while the GFS
is completely dry. In addition, there are some model ensemble
members showing greater rainfall amounts, in excess of 1 inch.
Due to the uncertainty, the probabilities for these showers are
near the 30 to 45 percent range, with the higher probabilities
along much of the coastal sections of the forecast region. The
forecast in this regard has not significantly changed from the
previous forecast.
.KEY MESSAGE 3...
Regarding temperatures, quite a downward trend forecast this
weekend and into early next week compared to Friday. Saturday
highs mainly range mid 60s to near 70, low to mid 60s Sunday,
mainly mid 60s to near 70 again Monday and then only mid 50s to
lower 60s much of the area Tuesday. This will be when strong
upper level low and its associated trough dive south into the
region. Tuesdays highs forecast will be near or slightly more
than five degrees below normal.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A cold front approaches Fri and passes Fri eve.
Mainly VFR thru most of Fri. Some of the outlying terminals
could drop to MVFR or lower in patchy fog and stratus,
especially KGON.
Chances for shwrs and tstms ahead of the cold front aft 20Z Fri
into Fri eve. Included MVFR in the PROB30 for this.
Light SW/VRB winds tngt. Winds increase out of the SW Fri aftn
with gusts around 20kt. Winds becoming NW behind the fropa Fri
eve.
NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...
Timing of shwrs and tstms on Fri could be aft 22Z.
.OUTLOOK FOR 00Z FRIDAY THROUGH TUESDAY...
Friday Night: Becoming VFR with NW winds.
Saturday-Sunday: Mainly VFR.
Sunday night-Monday: MVFR or lower possible with chance of showers
late at night into early Monday.
Tuesday: Mainly VFR.
Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90
&&
.MARINE...
For the marine forecast, initial sub-SCA conditions expected
for all marine zones. For Friday with the cold front, SCA
conditions develop on the ocean, mainly east of Fire Island
Inlet and continue into Friday evening. Expecting both SW wind
gusts up to 25 kt and ocean seas to reach 5 ft within these
marine zones. Otherwise, sub-SCA conditions for Long Island
Sound, Long Island Bays, NY Harbor and ocean west of Fire
Island Inlet out to 20 nm.
Potentially more SCA conditions possible Saturday night into
Sunday on the ocean with otherwise, sub-SCA conditions for the
weekend.
Good chance of SCA for all waters possibly as early as late in the
day Monday, but more likely Monday night into Tuesday morning in
response to a cold front passage. Expecting gusty NW winds due to
the cold air advection. Will need to monitor for trends as gales on
some of the waters cannot completely be ruled out.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory from 11 AM Friday to midnight EDT Friday
night for ANZ350-353.
&&
$$