textproduct: New York

SYNOPSIS

A weak cold front or trough moves through this evening with brief high pressure following through early Thursday. A strong cold front gradually approaches thereafter and moves through on Friday. High pressure then briefly builds in for the start of the weekend. A warm front passes on Saturday followed by a cold front Saturday night into Sunday. A secondary cold front passes Sunday night. High pressure returns Monday. Another frontal system looks to impact the region Tuesday into Wednesday.

NEAR TERM /UNTIL 6 AM THURSDAY MORNING/

A weak cold front/surface trough and associated shortwave aloft move through this evening, with high pressure building in behind it. Although the shortwave looks decent, not expecting any precipitation with the passage. There will also be some high clouds the first half of the night due to a passing jet streak.

As previously mentioned, high pressure builds in tonight. It looks like the return flow won't really kick in until later Thursday morning. However, the potential for fog/freezing fog will have to be monitored if a stronger/earlier return flow kicks in.

SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/

Key Messages:

* A strong cold front will move through the area on Friday bringing strong to locally damaging winds and moderate to heavy rain

* Temperatures drop back down to the 20s Friday night. Any leftover snowmelt and moisture laden grounds may freeze if winds are unable to dry out the area.

The main story in the Short Term period is the strong cold front that will move through the area. An upper level low dives from the Northern Plains towards the Great Lakes on Thursday while opening up and becoming negatively tilted. An associated surface low will track well north of our area, but will drag a strong cold front through. As the low approaches, the pressure gradient over the area gets tight as high pressure is slow to depart. This brings a strengthening southerly flow to the area. An impressive LLJ develops off the Mid-Atlantic coast. Latest guidance has the jet peaking ~65 to 70kt at 950mb and ~70 to 75kt at 925mb. Though wind gust forecast given this LLJ and a moderate low level inversion. Given the chance for heavy showers and potentially embedded thunderstorms, decided to go Wind Advisory everywhere since a decent percentage of these strong winds just above the surface may be able to get mixed down.

Not thinking thunder will be widespread or organized given the lack of any CAPE. If anything more organized did develop, in this low CAPE/high shear situation it would likely be a damaging wind threat. While there will be a decent period of moderate rain, any heavier rain/thunder will likely be confined to a shorter period sometime early Friday morning.

The cold front moves through on Friday and then winds become W/NW. Gusts pick up again at this time with decent cold advection. If we aren't able to mix down strong winds Thursday night/Friday morning, then Friday evening and night may end up having the stronger winds. Kept the Advisory up through Friday evening to cover this.

Temperatures drop quick Friday night. There is some concern of leftover snowmelt and rainfall being able to freeze. This will be dependent on how much those winds can dry out the area.

LONG TERM /SATURDAY THROUGH WEDNESDAY/

Key Messages:

* A few brief rain/snow showers are possible late Sat night into early Sun morning with a cold front.

* Temperatures moderated Sat-Sun, but frigid temps return on Mon.

High pressure builds briefly from the south early on Saturday. Low pressure over Ontario brings a warm front through late Saturday followed by a cold front late Saturday night into early SUnday morning as the low moves into Quebec.

Atmospheric moisture looks quite low, so no precip expected with the warm frontal passage. However, forcing may be strong enough with the cold front along with a slight increase in moisture to lead to a few 'brief' light rain/snow showers early on Sunday.

We'll dry out following the cold front under westerly winds, with a secondary cold front bringing in even drier northwesterly flow Sunday night.

Prior to the secondary front, temperatures should remain moderated with highs on Saturday and Sunday in the upper 30s to mid 40s. Lows on Saturday night will be in the 30s with most above freezing. However, due to the secondary cold front bringing in cooler continental air under northwesterly flow, lows on Sunday night look to return to the low to mid 20s.

Saturday through Sunday night will also be under a stronger pressure gradient with high pressure south and low pressure north, so expect a period of stronger winds through the weekend.

High pressure builds into the area from the Great Lakes on Monday with cold air settled. Highs on Monday will be in the low to mid 30s and lows return to the 20s Monday night as high pressure centers itself over the region.

High pressure backs to the south as Tuesday as another frontal system from Canada looks to impact the region Tuesday into Wednesday. Details on this system are still a little murky with some variability among the available model guidance, but POPs do return for the middle of next week with this system.

OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY

Thursday night: MVFR to IFR with rain. S winds G20kt developing during the first half of the night, increasing to 25-40 kt after midnight. SSW LLWS expected after midnight.

Friday: Rain in the morning with MVFR/IFR, then rain ending with VFR. S to SW winds G35-45 kt in the morning, shifting W G25-35 kt in the afternoon. LLWS early.

Saturday: VFR.

Sunday: Mainly VFR. Chance of MVFR with light rain/snow early in the morning. W winds G20-25 kt.

Monday: VFR. NW winds G20-25 kt

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

MARINE

A SCA remains in effect for all the eastern ocean through early morning. High pressure builds in from the west overnight.

Sub-SCA conditions then expected until Thursday night when a southerly flow picks up. A Gale Warning is in effect for all waters starting Thursday night and going until 1 AM Saturday. 40 to 45 kt wind gusts are possible during late Thursday night into Friday morning and then again Friday evening and night. During the morning period, isolated gusts up to 50 kt are possible for the eastern two ocean zones, Peconic and Gardiner's Bays and the eastern LI Sound.

A SCA will likely be needed on the non ocean waters Sat night as well as strong westerly winds continue behind a cold front. SCA conditions likely remain on the ocean waters into Mon. A period of gale gusts are possible on the ocean Sat night.

HYDROLOGY

Brief heavy rain will be possible late Thursday night into early Friday with showers moving across as well as any embedded thunderstorms. These will be quick moving and as such, are not expected to result in significant accumulations of rainfall. Around 1 inch to 1.25 inches of rain is forecast Thursday night through Friday but there could be some localized higher amounts. While hourly rainfall rates will mainly be around 0.25in/hr or lower, heavier showers and thunderstorms may be able to put out rate closer to 0.50-0.75in/hr.

Outside of minor flooding in low- lying and poor drainage areas in localized areas where multiple rounds of heavy downpours are received, no other hydrologic impacts are expected.

No hydrologic impacts are expected Saturday through Wednesday.

TIDES/COASTAL FLOODING

Astronomical tides will be increasing with a new moon occurring Friday evening. This will result in as little as 2 ft or surge causing minor coastal flooding impacts. A gale south-southeast flow ahead of a strong frontal system will bring potential for widespread minor coastal flooding during the Friday morning high tide cycle.

The timing of frontal passage (windshift) relative to the Fri AM high tide will determine how widespread minor coastal flood impacts will be. Windshift after time of high tide will increase potential for more widespread minor coastal flooding across vulnerable coastal locales along NY/NJ harbor, Jamaica Bay, western great South Bay (isolated moderate), and coastal Westchester/CT. A windshift before high tide will likely keep impacts more localized and moreso confined to NYC/NJ metro, Jamaica Bay and Western Great South Bay.

Offshore winds behind the cold front will end the coastal flood threat with subsequent high tides.

OKX WATCHES/WARNINGS/ADVISORIES

CT...Wind Advisory from midnight Thursday night to midnight EST Friday night for CTZ005>012. NY...Wind Advisory from midnight Thursday night to midnight EST Friday night for NYZ067>075-078>081-176>179. NJ...Wind Advisory from midnight Thursday night to midnight EST Friday night for NJZ002-004-006-103>108. MARINE...Gale Warning from 6 PM Thursday to midnight EST Friday night for ANZ331-332-335-338-340-345-350-353-355. Small Craft Advisory until 3 AM EST Thursday for ANZ350-353.