Wednesday Discussion : Preliminary Snowfall Forecast Thu 2/18/21

A weak storm system developing in the southeast will spread northeastward on Thursday.  As it does, it will likely spread snow into the Hudson Valley.  The details of how this event will unfold are a bit unclear, but hopefully will resolve themselves on Wednesday.  But for now, the potential exists for a moderate snowfall across the region.

Timing:
– 7am to 1pm : Light snow likely developing from SW to NE
– 1pm to 6pm : Snow becomes steadier and widespread
– 6pm to 6am Fri : Periods of snow expected
– 6am to 6pm Fri : Periods of light snow possible/likely

Impact/Conditions:
– Potential long duration snow event
– Periods of light to moderate snow
– Winds not an issue
– Temps in the 20s, snow accumulates on all surfaces
– Snow covered & icy roads likely

Snow Accumulations:
– Catskills & Upper HV (Zone 1,2,N3,N4) : 2 to 6 inches
– Mid & Lower Hudson Valley (Zone S3,S4,5-9) : 4 to 8 inches (locally up to 10″)

— Discussion —

A storm system developing in the southeast will move northeast early Thursday, into the Mid Atlantic states.  As it does, there are some questions about the manner in which the storm develops.  The storm track will follow the northern edge of the offshore ridge.  But how the energy consolidates is a bit less certain.  Here is a futurecast radar from 1am Thursday through 7am Friday, that shows a storm that looks a bit disorganized at times through its progression.

Futurecast Radar : 1am Thu – 1am Fri

The snow tries several times to push into the Hudson Valley on Thursday, before making a successful push northward late in the day on Thursday.  How exactly this storm progresses could have significant implications for accumulations in the Hudson Valley.  From the wide view perspective, it seems like 2 separate pieces of energy.  From the 500mb level, it looks like the energy gets stretched from Louisiana to eastern Maine.  This elongated look to the energy may give us an extended period of snow.

As a result, we’ll have to monitor the progression and development of the storm on Wednesday, before we issue the final snowfall forecast.  The potential for a long duration event, with an geographically extended system, leaves a lot of room for error in the preliminary forecast.  The probability our final forecast will differ from our preliminary forecast, is quite high.  If we had to list our confidence level on the accumulations, it would be Low to Moderate confidence.  There are a lot of ways the details could change on how this storm unfolds.  Please check back late on Wednesday afternoon, to see if we have any new data to share.  The “Final Snowfall Forecast” will be issued before 9pm on Wednesday.

11 thoughts on “Wednesday Discussion : Preliminary Snowfall Forecast Thu 2/18/21”

  1. Good morning guys I can’t tell you how much appreciate you telling all of us the next time the detailed forecast will be updated. I’ve stopped obsessing watching the weather on the evening news and throughout the day I just look at yours .. anxiety free:))

    Reply
  2. You guys are killing it this winter with the detailed forecasts and discussions. THANK YOU for being a down-to-earth, un-sensationalized, reliable weather source for the Hudson Valley!

    Reply
  3. A: As has happened several times recently as storms approach, your site is not fully-loading information and I actually have to go to Accuweather or Weather.com or NYC Media to get an accurate forecast. (If that suggests people are running to your site…then you’re server can’t seem to handle it, so you need a major upgrade because if you can’t perform when it is needed most then all the “great predicitons” are essentially worthless.

    B: It appears we’ve (in Ulster County) been downgraded from a Winter Storm Watch to just a Winter Weather Advisory…is this correct? Are we in line for less snow and ice?

    Buehler, anyone?

    Reply
  4. Everyone please, if you have to go out careful on the roads. Keep a blanket in car for emergency. And dress warmly and keep phones charged if possible and if you have a phone.
    Please be safe and careful.

    Reply

Leave a Reply to Sandi Krajeski Cancel reply