Winter Storm Discussion : Potential Huge Kickoff to Winter Season

With every passing hour, the likelihood of our 1st significant winter storm of the season increases.  The computer guidance is getting a better and better handle on the basic structure of this storm system, and how it will unfold.  Because of the complexity of this storm’s structure… we will continue to have details to iron out, right up until the start of the storm.  This will make pinpointing snow totals, timing, and impacts a bit tricky.  So lets start digging in…

Estimated Timeline:
– 8am to 12pm Sunday : Snow/sleet begins
– 5pm to 9pm Sunday : Snow/Mix tapers
– Sunday Evening : Cloudy, scattered snow/sleet/rain showers
– 12am to 6am Monday : Snow redevelops
– 6pm Monday to 12am Tuesday : Snow tapers off

Total Snow Accumulation Probability:
– Over 1 inch : 95%
– Over 3 inches : 75%
– Over 6 inches : 65%
– Over 8 inches : 60%
(*probabilities based off Poughkeepsie area and Mid Hudson Valley. Chances increase as you go north and up in elevations, and chances decrease as you go further south)

Precipitation Types:
– Zone 1,2,5&6: Snow… mixing with sleet Sunday afternoon.  Mostly snow Monday
– Zone 3&4: Mostly snow on Sunday, some sleet possible… best chance for heaviest snow on Monday
– Zone 7&8: Snow… mixing with sleet and freezing rain Sunday afternoon.  Mostly snow Monday
– Zone 9: Wintry mix, possibly light rain late Sunday. Changing to snow on Monday

Confidence : Medium
– Good handle on the basic structure of the storm
– Confident about timing for the first half of the storm
– Timing and location of Monday portion is lower confidence

Synopsis

The first half of this storm, the Sunday portion, we have a good handle on.  It’s the 2nd half of the storm, on Monday, that could give us some unexpected surprises.  But lets go through Sunday first.

The moisture likely arrives from mid to late morning from west to east.  You can see the purple on the map is indicative of sleet… not snow.  The reason is because there could be a thin layer of mild air in the atmosphere, that melts the snowflakes before they refreeze on their way to the ground.  We will have to see how thick that layer of warmth is, and if it stays further south.  But this could result in some parts of the region seeing a burst of snow, quickly change to a snow/sleet mix by late morning.  It’s one of the details that we’ll be monitoring.

As the storm moves in, the entire region should be seeing snow and/or sleet falling by lunchtime on Sunday.  Surface temperatures are expected to hold in the mid to upper 20s all day Sunday, plenty cold enough for frozen precipitation.  The major question that we will be focusing on, is how much mild air at the mid levels of the atmosphere we get.  That will determine whether we see snow, sleet or freezing rain.  But as we look at the progress of the storm, you can see that the first half of this system begins to taper off late Sunday afternoon and early Sunday evening…

Futurecast Radar Loop : 7am Sunday – 1am Monday

 

The bulk of the moisture associated with the warm front moves through by around 7pm.  This will result in most of the precipitation tapering off Sunday evening, and the Hudson Valley is left with scattered light snow, sleet and freezing rain showers.  A rather icy Sunday night lined up for anyone with travel plans.  But there should be a low pressure developing off the NJ coast, that will stall out south of Long Island.  So just at the end of this radar loop, you can see some of the wintry mix changing back to snow, and the snow beginning to fill in a bit on the radar image.  So when considering the first part of the storm (Sunday)… we’re leaning on the lighter side of accumulations.  When considering total snowfall amounts… what falls on Sunday will likely be about 25% to 30% of the total snowfall accumulations this storm brings.  

This leads us to the most uncertain part of the forecast.

Futurecast Radar: 1am Monday – 1am Tuesday

This is a futurecast loop of the final 24 hours of this storm, from 1am Monday morning.  Notice how disorganized this storm system becomes.  A coastal low pressure system develops as the Upper Level Low pressure moves to the coast.  It results in the redevelopment of a steady moderate snow across much of NY and the Hudson Valley.  This is easily the lowest confidence portion of our forecast.  Because if the position of the upper level low is further south or north… the band of moderate snow could be outside of our area.  If the coastal storm develops too late, the snow could be east of the Hudson Valley.  There are a lot of tricky pieces here… and Upper Level Low pressure systems are notoriously difficult to forecast.

So when we talk about snowfall accumulations, if things play out just right, over 12″ of snow is certainly possible.  At the same time, if the details are different from what we currently project… snowfall amounts could be significantly less than what you’re seeing and hearing.  So this is something to keep in mind when thinking about this storm’s forecast… even as we roll out our preliminary snowfall forecast tonight.  Remember… the 1st half of this storm… the Sunday portion… we have a moderately good level of confidence.  It’s the Monday portion… that remains more of a wildcard.  While a lot of guidance suggests the Hudson Valley is in the focal point of heaviest snow… like the GIF images above… we all need to take this into consideration.

Any way you slice it… this should be a wild start to the winter season!  Thanks for your support!!

37 thoughts on “Winter Storm Discussion : Potential Huge Kickoff to Winter Season

  1. So your projection at this time is that we could get anywhere from a very little snow accumulation to a very big snow accumulation…. wow, amazing!!

    • Kinda rude – these guys/this forecasting page is the ONLY go to forecasting I use. They are always right on the money, because they HEAVILY analyze every step, I for one appreciate it. Back in the day, had to “wing it”, why should that change now? Mother Nature IS in control. . .

    • As passionately as I love weather and accurate forecasting – I hate the trend of “blockbuster” weather. I love that HVW doesn’t sensationalize weather. They could easily go with the latter, instead they give us details as to why it’s uncertain. I respect that.

        • Ed, what happened? You weren’t always like this. Is it the hemorrhoids or is this still you lashing out because I took Katie to prom? We are married now. We have a kid. I’m sorry we fell in love, it wasn’t done to hurt you. Call me.

          • Who in the heavens is Katie!? EDWARD! Those hemorrhoids won’t be the biggest pain I’m your rear tonight! We need to talk.

        • Oh heck no! You’re not sitting on me all day, especially after you’ve eaten all those taco’s and drank all that beer! No wonder those hemi’s are all in an uproar! If you weren’t in so much butt pain you’d know the folks at HVW rock the forcast!

    • I’m with you Ed, it seems to have a run around of “what could be” if these conditions or those conditions. Just tell us what you see when it comes, no need to play 7 different scenarios.

  2. Appreciate the regular updates as you piece together how this storm will develop. Unlike Ed, I have no problem with you saying “I don’t know” if that is the case. If HVW doesn’t know, then neither does anyone else. We have an indoor activity early Sunday morning about 10 miles from home. Sounds like we’ll get there just fine, but the sooner we can finish the better. That is useful knowledge for planning.

  3. Thank you! You haven’t steered me wrong since I moved into the Hudson Valley and started following you.

    I echo everything that Frank said above… We appreciate ALL the updates you give us whenever a storm like this comes through.

    And ignore the idiots on here. 😉

  4. As a former teacher, all I had to do was check out the FB page and I knew if there was going to be school in the morning. Thank You HVW

    • If you don’t like the forecast, don’t read it Ed (or whatever your name is). HW Weather is the absolutely best forecast and never sensationalizes like the big stations. Thank you HV Weather.

  5. I’m a foul weather friend. I ignore HVW all summer but as soon as the temps drop, they pull me back in! Always an interesting read and love watching the predictions develop as you get more info.
    Thanks!

  6. Thank you, Alex and Bill! I so appreciate all your hard work and your explanations regarding these forecasts. I rely on HVW and ONLY HVW for the most accurate forecasts! Thanks again!

  7. Thanks Alex and Bill for all the work you do trying to forecast these storms. Its not easy and Mother Nature is always in control. You’ve always done right by me. I love reading you explanations of the weather and I have learned a lot by just reading about your forecasts every year. Keep up the great work and pay no attention to the crazy people who have nothing better to do that criticize. Thank you

  8. Thank you! Going to make sure college boy gets back earlier rather than later. Stay safe, hope you have lots of leftover turkey to keep you going!

  9. After a long talk with my wife (love you honey), an emotionally exhausting conversation with Kyle (who has a gorgeous newborn son), and most importantly, after a full tube of Preparation H, I realized you guys are right. Predicting the weather is tough, and you guys are excellent scientists. I’ve blown up my donut and plan on sitting down and getting some much needed rest if we get snowed in! Keep up the great work HVW (and the folks over at Prep H who make a fine ointment).

  10. Behold… The Key Board Warrior! Also known as Ed. SMH.

    Thanks for the good job you guys to for us who depend on you and not like to hide behind the internet.

  11. I notice that Orange County is not included in the moving orange banner headline at the top of the web page which lists warnings / watches. Is this an oversight? Just wondering.
    Thanks.

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