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Computer Model Trends: Another weekend storm?

Every now and then we get locked into a weather pattern where the storms are evenly spaced and consistent for a few weeks. Right now, it seems Southern New England is in a pattern that threatens the area with snow every weekend. There have been blizzards (one big, one smaller) on two consecutive weekends, and most computer models are honing in on another storm threat for this coming weekend.

GFS (Global Forecast System)

The 12Z (7am) run of the GFS brings a storm to Southern New England Saturday night into Sunday. The combination of the track and limited cold air supply means rain or a mix from the coast to Providence, with snow/mix further inland. I think it’s too early to focus on the particulars of the GFS solution, and rather we should just focus on the fact that it develops a storm. Climatologically, in late-February, with the forecast track, there should be enough cold air around for mainly wintry precipitation inland in Southern New England. The operational GFS model has been indicating minor-moderate storm for several runs, and, now, nearly all the ensemble members agree, although precipitation-type is an issue for most.

GFS snow forecast - Some snow in all of Southern New England, heaviest inland
GFS snow forecast – Some snow in all of Southern New England, heaviest inland
GFS - A close call between snow/rain in I-95 corridor. Notice the high pressure to the northeast of the developing storm. It's not in ideal position. It would be better if it were farther west.
GFS – A close call between snow/rain in I-95 corridor. Notice the high pressure to the northeast of the developing storm. It’s not in ideal position. It would be better if it were farther west.
GEFS - most members show a minor/moderate storm with a close call between rain/snow
GEFS – most members show a minor/moderate storm with a close call between rain/snow

Canadian (GEM)

The Canadian model also has a minor-moderate storm with limited cold air and mainly rain over Southeastern New England. Overall, it looks similar to the GFS.

Canadian snow forecast - Most of the snow is in interior New England based on the track of the storm being too close to the coast
Canadian snow forecast – Most of the snow is in interior New England based on the track of the storm being too close to the coast

European (ECMWF)

The European model has a slower developing system that brings snow/rain to Southern New England Saturday night and Sunday. The evolution of the ECMWF solution indicates a Norlun trough hanging behind the storm as it departs late Sunday. That may be enough for a transition from rain to snow in most areas. It is not a big storm, and the areas that see all snow would be looking at 4-6″.

ECMWF snow forecast - not much snow in RI and SE MA as the storm tracks just a bit too close for snow
ECMWF snow forecast – not much snow in RI and SE MA as the storm tracks just a bit too close for snow

JMA/NOGAPS/UKMET

A few other models also indicate the same storm potential that most of the rest of the guidance is suggesting. A storm that come close enough to bring steady precipitation, with uncertainty about snow/rain because of the proximity of the storm, position of high pressure to our northeast, and an easterly wind direction bringing in some milder air.

JMA - Hard to know the exact track of the storm because we only see 24 hour increments, but it looks like it's far enough south for mainly snow, though not a huge storm.
JMA – Hard to know the exact track of the storm because we only see 24 hour increments, but it looks like it’s far enough south for mainly snow, though not a huge storm.
NOGAPS - a storm in similar position to most other models. Snow inland, rain coast
NOGAPS – a storm in similar position to most other models. Snow inland, rain coast
UKMET - hard to know the details, but it has a storm off the SNE coast early Sunday
UKMET – hard to know the details, but it has a storm off the SNE coast early Sunday

The bottom line is it looks like we’ll have another storm to deal with this weekend, but, right now, it does not look like an exclusively snow scenario for most of CT, RI, and MA. Given the time of the year, if it does develop just far enough south to throw the wind around to the northeast, instead of east or east-northeast, that would favor snow. At this point, the consensus forecast is for a track a bit farther north that brings rain/mix into play. We’ll evaluate the computer models again Wednesday in another update.

Fred Campagna

President and Chief Meteorologist - Right Weather LLC AMS Certified Consulting Meteorologist #756 AMS Certified Broadcast Meteorologist #126

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