Update on the snowstorm with a slight northwest shift:
First, for today there will be minor accumulations of an inch or two for areas north and west of Long Island, with Long Island getting mostly rain with some wet snow possibly mixing in during the afternoon before ending later this afternoon.
As for the big snowstorm from later Wednesday into Thursday, the Euro still keeps it as all snow for most of Long Island with some sleet mixing in along the south shore and in eastern Suffolk. The projected snowfall from the Euro ensemble mean did shift again slightly to the northwest. The GFS and Canadian models keep it as all snow, but the NAM and UKMET are significantly farther northwest with rain for most of Long Island, except for northwest Nassau. The RGEM keeps it as all snow with extremely heavy snow for northern and western Long Island. Today will be a big day to watch to see if it shifts more to the northwest.
Here are comments just in now from the National Weather Service covering Long Island and the tri-state area:
- Given the strong arctic high pressure to the north with surface and low-level temperatures at or below freezing and a lack of a sufficient warm-nose aloft, this should remain an all-snow event for much of the tri-state area.
- Depending on the exact strength and track of the surface low, parts of Eastern Long Island may mix with sleet which would reduce any snowfall totals in that area, but the event is still 48 - 72 hours out so specifics on snowfall totals will be discussed as we approach the event. Generally, however, there is decent potential for much of the area to see more than 8" of snow with higher amounts in any mesoscale banding that occurs on the NW side of the cyclone.
- Winds will increase out of the NE Wednesday evening and Thursday morning as the tightening pressure gradient will allow for sustained winds of 25 - 35 mph possible along the coastline and gusts upwards of 40 - 45 mph for a time, which may cause close to blizzard conditions for some. The low pressure isn't impressively strong however, so fine-tuning the winds will be made as we approach the event.
- There is still some question as to how quickly the low will pull out on Thursday, with the ECMWF (Euro) lagging a little behind the GFS, so steady snow still likely in the morning, then gradually tapering off from W to E through the day.
- It is worth noting that collaboration between neighboring offices was conducted and have decided to not yet issue a Winter Storm Watch as the event is more than 48 hours out, there is still some uncertainty as the the extent of coastal precipitation type mixing, and we have a minor mixed precipitation event set to occur today.
LONG ISLAND FORECAST:
Today (Monday): Cloudy with rain developing in the mid morning, possibly mixing with wet snow by mid-afternoon before ending in the late afternoon. Little to no accumulation expected. Temperatures dropping from the low 40's in the morning to the mid to upper 30's by mid to late afternoon. The wind will be fairly light at around 10 mph from the NNE this morning and NNW in the afternoon.
Tonight: Clouds in the evening and then becoming mostly clear with lows in the upper 20's to low 30's.
Tomorrow (Tuesday): Mostly sunny, breezy, and cold with highs in the upper 30's to near 40 degrees. Wind gusts up to 20 mph from the NW.
Wednesday into Wednesday night: Cloudy with snow developing around late afternoon or early evening from southwest to northeast and possibly becoming heavy at times at night. Highs in the low to mid 30's. Wind gusts at night could be 35 to 45 mph out of the ENE to NE by late at night. There is an increasing chance for sleet to mix in along the south shore and east end, and it can't yet be ruled out for central Long Island as well. Blizzard conditions are possible for a time late Wednesday night into early Thursday morning for areas that stay all snow. The potential exists for 6 to 12 inches of snow, with the highest totals in northern Nassau, with possibly 3 to 6 inches for southern and eastern Suffolk. Stay tuned for the latest updates as it will be a close call.
Thursday: Windy with snow (possibly rain for eastern Long Island) tapering off to snow showers/ flurries by late morning or early afternoon. Highs only in the low to mid 30's. Wind gusts over 35 mph out of the NNE in the morning, shifting to NNW in the afternoon and decreasing to 25 to 30 mph.
Friday: Mostly sunny and cold with highs in the mid 30's.
Saturday: Mostly sunny and cold with highs in the mid to upper 30's.
- 1st image: Projected snowfall through 1 AM Friday from the Euro ensemble mean
- 2nd image: Probability of greater than 6 inches of snow through 1 AM Friday from the Euro ensemble mean
- 3rd and 4th images: Maps from the Euro for 1 AM and 7 AM on Thursday
- 5th image: Maximum projected wind gusts in knots through 1 PM Thursday from the Euro
- 6th image: Projected snowfall through 1 AM Friday from the Euro
- 7th image: Projected snowfall for Long Island for the next 15 days as a running total from every Euro ensemble member
- 8th image: Projected temperatures for Long Island for the next 10 days from the National Weather Service model blend