textproduct: New York

WHAT HAS CHANGED

Increased likelihood for a dusting to 1/2" of light snow for much of the area late Tonight.

KEY MESSAGES

1) Dry conditions and below normal temperatures today.

2) Scattered snow showers or a brief period of light snow likely late Tonight with vigorous shortwave/cold frontal passage.

3) The probability for a light accumulating snowfall Sunday night into Monday remains low.

4) Progressive low pressure systems will bring rain/snow chances mid to late week. Low predictability on p-type details at this point.

KEY MESSAGE 3

Deterministic GFS/ECMWF/GEM/NAM model guidance continue in good agreement with northern stream shortwave and southern stream low remaining unphased, with a progressive west to east movement of a southern low and secondary development along the the Mid Atlantic coast and then offshore. This prevailing scenario at this point would only potential for a period of light snow (possibly mixed with rain NYC/NJ metro and LI) or snow showers/snow flurries Sun Night into Mon. This would mainly be forced by northern stream shortwave lift briefly expanding northern edge of precip shield.

ECMWF/GFS/GEM NWP ensemble means have come into better agreement with keeping low pressure well south of the region as well, with ECMWF now in line with GEFS and GEPS in mainly clustering low pressure tracks off the Mid Atlantic coast and well south of the region. ECMWF has trended down from a 30-50% ensemble relative frequency of 1-3" 24hrs ago, down to less than 20%. Very slight probs (less than 10%) of this scenario with GEPS and GEFS.

GFS and ECMWF AI ensembles are exhibiting similar behavior to their NWP counterparts, with both trending south with their QPF axis over the last 24 hours. The 00z GFS AI is now south of region with it probs for .1" liquid qpf, while 00z ECMWF AI continue to trend downward with prob for a 1-3" snowfall (now only 10-20%, half the prob of 24 hrs ago).

Latest NWS NBM superensemble, prob of 1" snowfall remains in the 10-20% range. 00z WPC WSE mean of around 1/2", with reasonable worst case of 3-5". This is half of yesterday, and seems like a reasonable forecast at this point.

Ensemble sensitivity still appears to predominantly to lie in shortwave energy coming onshore across the PAC NW this evening, and its amplitude/timing and degree of interaction with the southern stream upper low Sun Night/Mon. A deeper northern stream shortwave solution favoring more interaction with southern stream and farther north/amplified surface low pressure, which is seemingly accounting for the reasonable worst case scenarios.

Have stayed close to NBM pops, with continued low probability for a light accumulating snowfall. With key shortwave features coming onshore this evening, should see more refinement in this forecast over the next 24 hours.

OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY

Saturday: VFR. W wind gusts 15-20 kt possible.

Sunday: VFR.

Sunday night and Monday: Mainly VFR. Chance of MVFR or lower and snow, mainly Sunday night and early Monday.

Tuesday: VFR.

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

MARINE

Sub-advisory conditions through Sunday as high pressure builds south and west of the waters. The exception will be potential for marginal SCA gusts Fri Night into early Sat AM with a cold frontal passage.

Low potential for SCA conditions with low pressure passing to the south and east Sunday night into Monday. Next chance for SCA Tuesday Night into Wed in wake of a cold frontal passage.

OKX WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. NJ...None. MARINE...None.