Winter Storm Recap : Nor’easter Thu 11/15 – Fri 11/16

Wow… what a start to the 18-19 winter season!  Our first winter storm system slammed the Hudson Valley Thursday afternoon and evening, and lingered into Friday morning.  The impacts across the region were very significant, causing some parts of the area to be crippled in terms of the Thursday PM commute.  So we’re going to go through this storm in detail, and discuss how our 1st storm of the season caused so much distress on the Hudson Valley.

To begin, lets compare the forecast against what happened.  Below are:
1.  HVW Final Snowfall forecast
2.  The Snow History map… a visual representation of what actually occurred
3.  The Final Snow Reports… from the National Weather Service

The primary criticism that was echoed from the general population across not only the Hudson Valley, but the greater Tri-state area, including NYC… was that nobody was forecasting this much snow, and that “we were completely unprepared”.   There was a widespread feeling about being caught off guard.

So how about our snow totals, where did they stand?  If we break down our forecast into the 3 different forecast ranges [5″-10″, 4″-8″ & 3″-6″], and compare to what actually occurred, how did it compare?  To do this, we try to quantify how much of the area fell within the forecast, and how many areas were outside the forecast range.  Then we will assess the result of our forecast accounting for only the snow totals (not addressing timing or impact).

  • Catskills (zone 1&2): Forecast 5″ to 10″ ….. Western Greene, Delaware & Sullivan County were generally within this range, with lots of 5″ to 8″.  Western Ulster County was on the high end, even exceeding a bit… with West Shokan with 13.0″ and Phoenicia at 11.5″.  Result: Very Good (9/10)
  • Mid & Upper Hudson Valley (zones 3-7): Forecast 4″ to 8″….. Columbia & E. Greene County were within range.  Much of Ulster, Dutchess, & Orange counties over achieved.  Almost every report from those 3 counties fell within a range of 8″ to 12″ instead.  Result: Decent (6/10)
  • Lower Hudson Valley (zones 8&9): Forecast 3″ to 6″…. Westchester, Putnam, and Rockland counties generally saw 5″ to 8″ on average.  There was some overlap, but a lot of 6 and 7 inch totals were common.  Result: Good (7.5/10)

So after looking at the details… the area that saw the greatest difference between the forecast and the result, was the Mid Hudson Valley.  We expected widespread 4 to 8 inches in that area… but saw widespread 8 to 12 inches instead.  A lot has been made of this… probably more than would be made if it was the middle of winter.  Because this was the first storm of the year, and because of the impact on the PM commute, there has been extra frustration around forecasts on this storm.

So why were the totals higher than our forecast?  There were two major reasons, in all actuality… and they’re both related to the same root cause.  Quite simply… it was colder than the computer models projected.  It’s just that simple, and it played out in 2 ways.

  1. Snow ratios were higher than expected.  Snow ratio means how much snow falls, for every inch of liquid precipitation.  The standard average is 10 inches of snow, for every 1 inch of liquid… or a 10 to 1 ratio.  This time of year, because it’s generally milder than mid winter… it’s common to see 8 to 1 ratios… which generates a heavy, wet snow.  But this storm was so cold during the commute… the snow was fluffy and light, which made for 12 to 1, or even 15 to 1 ratios.  So the snow piled up even faster than what we projected in some areas.
  2. More snow fell… and less sleet and freezing rain, than expected.  Also a product of the colder atmosphere.  The total amount of moisture we saw was actually what was projected.  The problem, was the composition of that moisture.  Most locations saw all snow, until the precipitation tapered off between 9pm and midnight (80%+ of storm was snow).  This is different than what the models suggested…

The computer models projected the wintry mix to kick in a little earlier (roughly 65-70% of the storm being snow), which would have kept snow totals a couple inches lower, with a bit more sleet and ice on top of the snow.

Final Forecast Verdict

In total, the forecast was really quite good.  The specific snow amounts may have been 2 to 4 inches higher than forecast in the Mid Hudson Valley… but the impacts we highlighted in the forecast were precisely accurate.  In EVERY text discussion, Facebook Live stream, and radio broadcast discussion we did… we highlighted just how horrible the commute would become.  We spotlighted the trifecta of factors…
1.  First snow of the season
2.  Just in time for PM commute
3.  Intense snowfall rates of 1 to 2 inches per hour

We explained that the very cold conditions would lead to instant accumulations on all surfaces… something that is very abnormal for mid-November.  We explained that the timing could not be worse.  Snowfall rates of 1 to 2 inches per hour, starting between 3pm and 5pm, would lead to conditions being fine one moment… and being extremely treacherous 30 minutes later.  Then factor in that it’s the 1st storm of the season… and it was a recipe for disaster.

If this sounds defensive, it’s not meant to… but it’s meant to be an explainer.  There has been a lot of finger pointing by people in charge, especially in the NYC/NJ area.  The conditions in and around NYC were exceptionally horrible, with major roads at a standstill for hours.  Even locally, reports of 30 minute commutes taking between 2 and 3 hours to travel, had residents furious.  Blame was being placed on local municipalities for not doing an adequate job, for not keeping the roads passable.  That there is no excuse in the northeast for roads becoming parking lots… and people being stranded for hours on the roadways.

The unpopular fact of the matter is… this is what happens when it snows at 1 to 3 inches per hour, for 3 to 4 hours.  Even if road crews had every truck on the road working as efficiently as possible… it is impossible to keep up with those snowfall rates.  This is why we explained repeatedly how truly horrendous the PM commute would be, and to get to your destination before it started.  There were far too many people on the roads, for the type of weather that was occurring.

Hopefully this event will be used as a teaching moment.  Pointing fingers and shirking responsibility won’t help make sure it doesn’t happen again in the future.  We’ll work extra hard to make sure that we get the details as precise as possible, to provide the best information for planning, and keeping people safe.  We’re not always going to get every detail correct, but we can promise you that the difference between 6″ and 10″ was not what caused the problems we saw around the Tri-State.  Thanks for reading… and thanks for all your continued support!

12 thoughts on “Winter Storm Recap : Nor’easter Thu 11/15 – Fri 11/16”

  1. Finger pointing is all anyone can do anymore. The road issues were not caused by a forecast issue it is caused by incompetent people in government. In the private world, if you know what you are doing you are ready for snow by the end of September, towns were running trucks dumping salt on 3-4 inches of snow with no plows on. In dutchess the state, county and my town is using straight salt with no sand this gives *no* traction you need the sand on the road to give traction. This all comes down to government incompetence and corruption, putting liquid calcium down (those white lines you see sometimes days before the storm) is a waste, but someone was paid good money for those brine systems.

  2. I traveled from Kingston to Accord starting at 7 pm during the storm, a commute which takes about 25 minutes in dry road conditions. It took about 45 minutes which isn’t too bad considering there was about 5 inches of snow on the road. The vehicles traveling with me were all going 25 mph and kept a minimum of 100 yards between them. I enjoy driving in the snow but this was a white knuckle experience because it was almost impossible to determine where the edges of the lane began and ended. I saw no vehicles that went off the road while on 209. In Kingston it was a completely different experience. On 9w I saw several cars off road and at least one fender bender; all of them were AWD or 4-wheel drive. AWD and 4-wheel drive give you a slight edge in driving traction ONLY if you have tires with sufficient tread depth. If you are fish-tailing or sliding sideways while going up hill, you need better tires, and AWD doesn’t mean that you can travel at the same speed during a snow storm that you can during dry road conditions.

  3. John struck a chord. Here in Mahopac there was absolutely no prior spraying of the beet juice/salt solution on the roads as is the procedure in all forecast snow or sleet storms for the past several years. Also absent was any explanation by the Town of Carmel as to why this misstep occurred.

    BTW…it does have a positive effect.

    • I work for a municipality. I put down a salt and liquid calcium mix before flakes started falling. It usually helps burn the first couple inches. This storm was an exception. Snow came in like a wall at 2 inch an hour rates instantly causing it to accumulate right away

  4. I too agree with John. That said, HVW did an outstanding job informing us about this storm. To prepare, we knew when it was coming & approximately how much to expect. So what if the totals were not 100% correct, they were close enough. Thank you HVW for your hard work & keeping us informed in a timely manner.

  5. People really need to walk a mile in the shoes of the folks who take care of the roads and then perhaps they will stop blaming and bitching. Come on now… they do the best they can. Mother Nature does what she does and sometimes it is severe. This was a severe storm.

  6. So, every town, city, county and the state all screwed up at the same time?

    Several of you sound like you would even blame some one for the destruction that the recent hurricane Michael left in Florida.

  7. There are many reasons why forecasts can be wrong the main one Mother Nature will do what she wants to do that’s why they call it forecasting and not “The final word”, Mother Nature has the final word.

    Sometime there is to much reliance on Computer Models, once a storm reaches your area get up, go outside just like you guys did and report what’s happening not what should be happening. You guys did a good job.

  8. The storm was talked about for 2 days prior. This was a complete dropped ball with getting trucks out to plow.
    The worst culprit here was the State DOT. Many towns and municipalities were in fact out plowing. I traveled route 22 up from Somers to Pawling then took 55 from Pawling to Poughkeepsie. All state roads. They were HORRENDOUS with 6-8 inches piled up on the road. Unacceptable. I also saw virtually No state DOT TRucks out plowing most of my drive on the state roads. It was almost like an intended neglect which I’m sure was attached to not wanting to pay overtime hours to put extra crews out on State roads to help control expenses. I spent 3 hours stuck on the mountain on 55 coming out of Pawling. People were stuck all over the mountain. 1 state DOT truck passed us all with its plow up and did nothing but leave us stranded. It was absolutely unacceptable especially with the Govenor just winning a 3rd term. I went to school in Buffalo and this type weather happens all the time. How can the same organization State DOT be so different in handling snow. They are usually why the Taconic is so bad and has so many accidents when it snows. Maybe we need to start sending our regional DOT plow drivers out there to better learn how to plow the roads during heavy snow to keep people moving.

    On the positive side a BIG SHOUT OUT to the Town of Pawling, Town of Poughkeepsie, City of Poughkeepsie, Dutchess County DOT, and the Dutchess County Sheriff’s Deputy who was the only person that stopped to help me during my 6 hr. Trek home on Thursday for their efforts. Their work was great and the roads in these areas although snow covered were passable and manageable.

  9. I have a question about how the snowfall amount is calculated officially(after the fact, not in the forecast). In the live videos, you made two points that made me curious. First, I think it was Bill, during a live video measured the snow on the concrete and then the grass–and there was an inch discrepancy, with the grass measurement being higher. I found this matches with my own experience, and I understand why. But which do they use for “official” readings? (Or is their device a happy medium?)

    Second, and more importantly–during a live video you (I think it was Alex) noted that the fluffy snow would later be pressed down by the heavier ice, changing again the measurements. In my case, I measured 9 inches of snow at 9 p.m., just before the ice began. The next morning even after a few hours of ice and more snow, the measurement was still the same–about 9 inches. Obviously, as Alex had noted and I experienced, there was a difference in the amount that fell and the amount of depth actually there on the lawn on Friday morning. So which numbers does the NWS measure? Given that our area (Millbrook) came in at 8.5 I am guessing that they measured actual depth post ice, versus actual amount that came down. Is there a way to tell how much actually fell? Just wondering.

  10. Grace,

    My understading when measuring snow ddpth it really depends on the wind and drifts.

    Storms with little wind you can best gage with a simple ruler method.
    Storms with high winds and drifting the three measurement rule gets the closests guestimates as to depth. Measure the lowest point even if its bare ground, meadure the middle of the highest drift then measure the highest point of the highest drift add each measurement even if the first is zero, add the three numbers and divide by three. Thst would give you the average snowfall.

    The NWS would collect snow and bring it down to water equivelent and ratios to temperature will give you the amount fallen. Knowing the liquid equivelent to ratio based on temp. is more accurate.

  11. I wanted to thank you, actually. It was your forecast, which emphasized the impact on the evening commute, which convinced me to leave work early. So…thank you!


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