Islip, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

329
FXUS61 KOKX 021121
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
721 AM EDT Wed Apr 2 2025

.SYNOPSIS...
High pressure builds offshore this afternoon, allowing for a warm
frontal passage Thursday morning. An associated cold front drops
into the area by Friday. Unsettled conditions are likely this
weekend with a frontal boundary in the vicinity. The front moves
offshore on Monday with high pressure slowly returning into
Tuesday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Forecast on track. High pres centered over QC ridges swd into
the region today, with the sfc ridge axis drifting E of the cwa
by the end of the day. This will result in lgt NE winds to start
the day, veering to the SE by this aftn. Dry mid lvls no pcpn
is expected, but mid and high clouds should thicken this aftn
per model progs and the current IR over OH. The NBM was used for
temps. Cool with highs in the 40s fcst.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Onshore flow builds llvl moisture tngt. As the bl cools,
stratus, fog and dz expected to develop late tngt into Thu. The
fog will be difficult to displace on Thu with continued onshore
flow and a thick high cloud deck produced by the subtropical
tap. Nonetheless, still expect wrn areas to at least break out
with the flow coming around to about 210. This should allow
these areas to warm into the lwr 70s. If the area does not
break out temps will be a bust.

The cdfnt associated with the massive sys approaches late Thu,
and gradually sinks thru the cwa on Fri. All of the jet energy
escapes into Canada, so there will not be much upr lvl support.
This is likely why the models are not initiating much over the
area thru the period. Will not include tstms in the fcst at
this point, given the lack of forcing and weak instability. Best
chances for tstm development Thu aftn/eve across wrn zones,
based purely on available CAPE. Best spot may be invof nwrn
Passaic into Bergen with some upslope suppling trigger help.

Went with the NBM for pops and temps thru the period.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Key Points:

*Unsettled conditions are expected this weekend with a frontal
boundary in the vicinity.

*Showers are most likely on Saturday and then again late Sunday into
Sunday night.

*Improving conditions are likely Monday with high pressure slowly
building towards the area on Tuesday.

*Seasonably cool temperatures Saturday should trend warmer on Sunday
with some 70s possible for NE NJ, NYC metro and Lower Hudson Valley.
Temperatures then trend cooler early next week.

High pressure over New England Friday evening will quickly pass
offshore. The frontal boundary that moved south of the area early
Friday will begin retreating northward as a warm front into
Saturday. This is in response to an amplifying shortwave over the
southwest U.S. and anomalously strong ridge over the western
Atlantic. Friday night will be dry with increasing chances for rain
on Saturday. The most organized forcing passes to our northwest, but
warm advection and overrunning support the likely PoPs (60-70
percent) from the latest model consensus. The northern tier stands
the best chance (80 percent), closer to the larger scale lift from a
strong upper jet well north of the area. Rain remains possible
Saturday night, but could trend towards more light rain and drizzle
as the warm front moves closer to the area.

There is still some question with the placement of the warm front on
Sunday. The model trends have been coming together and placing the
warm front north of the area on Sunday. This seems reasonable given
the synoptic pattern. Questions remain on the amount of clouds and
any lingering showers despite increasing confidence on the placement
of the warm front. The main challenge will then be with how warm
temperatures will ultimately get. There is still a large spread in
the NBM with 25th percentile showing highs in the upper 50 to mid
60s. The deterministic NBM seems to lie close to the 75th
percentile, which yields highs in the middle to upper 60s inland
with some lower 70s in NE NJ, parts of Lower Hudson Valley and NYC
metro. Temperatures across coastal CT and Long Island stay in the
lower 60s due to onshore flow. It should also be noted the NBM 90th
percentile brings temperatures into the lower 80s in NE NJ with the
usual warmer spots away from the coast (Long Island, Southern CT)
into the mid 70s. Have sided close to the NBM deterministic for now,
but there is room for adjustment upwards for locations away from the
coast, especially if the latest trends continue.

The western Atlantic ridge also weakens as the upper trough
approaches Sunday night. This will allow low pressure and its
associated cold front to pass across the area. Showers are likely
Sunday night, but have left thunder out of the forecast at this time
with questions remaining on instability. The front will push
offshore early Monday leading to improving conditions to start next
week. The upper trough is progged to remain over the northeast early
next week so high pressure will likely take some time building in
from the west.

Note: While there will be rain at times this weekend, the risk of
any impacts from flooding is very low as the flow is progressive.
The latest NBM probabilities for observed greater than 1 inch in a 24
hour period this weekend remain very low and generally 10 percent or
less.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
High pressure builds over New England this morning and then off the
coast this afternoon. A warm front approaches from the southwest
tonight and lifts over the terminals Thursday morning.

VFR through 00z. MVFR conditions are likely to develop
thereafter with the likelihood of IFR towards 05-08z. LIFR is
then expected around day break Thursday, continuing for most of
the morning. A shower cannot be completely ruled out tonight
with drizzle late tonight into early Thursday morning.

N-NE winds around 10 kt or less before day break. Winds will
continue veering to the ENE-E this morning, becoming E-SE by early
afternoon. Wind speeds will increase to 10-15 kt. Gusts to around 20
kt are possible, especially for coastal terminals late afternoon and
early evening. SE winds 10-15 kt continue tonight, veering to
the S and SSW Thursday morning with the passage of the warm
front.

LLWS expected late tonight and Thursday morning with SW winds 45-50
kt at 2kft.

 ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty...

Timing of wind shift to the SE may be off by 1-3 hours.

Wind gusts late afternoon/early evening may be occasional.

Amendments for flight category changes likely for tonight into
Thursday morning.

Low confidence visibility forecast Thursday morning.

.OUTLOOK FOR 12Z WEDNESDAY THROUGH SUNDAY...

Thursday: LIFR to IFR in the morning, potentially improving to
MVFR in the afternoon. Showers possible. S gusts 20-25 kt
possible along the coast.

Friday: MVFR early with a chance of showers, then VFR.

Saturday: MVFR to IFR with showers likely. E wind gusts 15-20kt.

Sunday: IFR in the morning, becoming MVFR. A chance of showers.
S gusts 15-20 kt possible.

Detailed information, including hourly TAF wind component forecasts,
can be found at: https:/www.weather.gov/zny/n90

&&

.MARINE...
Seas will remain elevated on the ern ocean today, and then winds and
seas increase thru Thu. The sca has been extended right thru
thu as a result. A sca goes into effect for ANZ355 this eve, and
goes thru Thu as well. Winds on the remaining waters likely at
sca lvls Thu, but held off on the advy for now. Winds and seas
gradually subside late Thu ngt and Fri.

There is a chance for dense fog on the waters late tngt thru
Thu.

Conditions should remain below SCA levels Friday night through
Saturday night. The next chance for SCA conditions appears to be on
Sunday as a warm front lifts north of the waters. Winds could
approach 25 kt on the ocean and seas will likely build to 5-6 ft.

&&

.HYDROLOGY...
No hydrologic impacts are expected through early next week.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
NJ...None.
MARINE...Small Craft Advisory until 6 PM EDT Thursday for ANZ350-353.
     Small Craft Advisory from 6 PM this evening to 6 PM EDT
     Thursday for ANZ355.

&&

$$

SYNOPSIS...JMC/DS
NEAR TERM...JMC/DS
SHORT TERM...JMC
LONG TERM...DS
AVIATION...DS
MARINE...JMC/DS
HYDROLOGY...JMC/DS