Preliminary Storm Forecast : Wednesday Wildcard 3/20/18

– 6pm Tuesday – 6am Wednesday: Light snow showers possible
– 6am – 10am: Snow develops from south to north
– 10am – 6pm: Snow could fall heavy at times, especially SE HV
– 6pm Wednesday – 12am Thursday: Snow tapers from west to east

– EXTREME uncertainty with forecast
– Position of storm vital to forecast, guidance struggling
– Potential for significant increases or decreases to snowfall forecast

– Catskills (Zone 1&2) : Coating to 3 inches
– Majority of Hudson Valley (Zone 3,4,5,6 & 7) : 2 to 6 inches
– Lower Hudson Valley (Zone 8&9) : 4 to 8 inches (possibly more)


We cannot emphasize the uncertainty with the forecast enough.  We have opted for a mid-ground approach based on the latest guidance.  The latest thinking is that this storm puts the Hudson Valley on the edge of the storm, with the bulk of the storm focuses south of I-84… and areas north of there with the potential to see very little.  As the forecast hones in on the position of the storm, expect modifications to the forecast accordingly.

This is our starting point… based on the entire package of data that we have, which factors in:

– Computer model data over the last 48 hours (Since Sunday)
– Trends of the model guidance on Monday
– Historical experience with the behavior of the guidance and these type of situations
– Atmospheric pattern and setup for this situation

It stands to reason that this storm will be focused south of the Hudson Valley, but we need to be vigilant and see just how involved we may become with this storm.  Expect lots of updates and possible changes on Tuesday.

Monday Afternoon Discussion : Nor’easter Looking Likely

Alex and I have a running joke.  Basically, any time I post commentary on a potential storm system… as soon as we publish the discussion… the forecast undergoes major changes.  On Sunday, I posted a discussion about how social media takes computer model information that is 7 days out… and turns it into hype and fear.  I discussed how the hype around Tuesday’s major nor’easter was just that… hype.

But it turns out the hype may have been right… but for the wrong reasons.  The 1st storm will miss us to the south and go out to sea… but it’s the 2nd piece of energy… a 2nd storm… that is looking increasingly likely to impact the Hudson Valley.

Rapidly Changing Information

It likely comes as no surprise, that things are developing quickly.  Guidance is struggling to determine how much this storm can come up the coast.

There are multiple features at play… such as the strong northern jet we mentioned yesterday.  That feature will be working against this system’s northward progression, trying to usher the storm out to sea.  The storm will be guided by a deepening, negatively tilted trough along the east coast.  The trough will try to tuck the storm in close to the coast, and up the eastern seaboard.  Ultimately… it’s a battle between these two weather features… and the result of how these features interact, will determine where the storm tracks.

We’re going to have our hands full all night on Monday, and on into Tuesday.  Expect more updates… both here, and on Facebook.  We will have a ‘preliminary snowfall forecast’ out tonight… hopefully by 10pm.  That’s not a firm deadline, but what we’re going to shoot for.  Have a nice afternoon and early evening!

Sunday Discussion: Still Watching the Storm

Forecasting the weather has changed a lot in the last few years.  The internet is primarily responsible for that.  The truth is, that if you want to spend the time and energy… you can have access to any of the information that we use to generate our forecast.  Heck… HVW could not exist in the ‘old’ weather forecasting world.

It used to be that you got your weather forecast from the radio, TV or news paper.  Even The Weather Channel was an innovator in weather communication back in the 1980s… providing us with a place to get the weather forecast 24 hours a day.  Now, the internet provides access to information for every American.  That means you can pull up the GFS, European, or NAM model.  The HRRR or RAP model… any radar, or satellite image… or any other obscure piece of weather data, that satisfies your weather hunger.

It’s fantastic, because it allows us to operate HVW.  We don’t have to be a major news network to reach you… we don’t have to have a contract with a newspaper or radio station… however our good friends at iHeartMedia have given us the opportunity to reach out to you over the radio waves.  But the fact is, Hudson Valley Weather can exist, because we can access all of the weather data… chop it up into consumable facts and figures, and generate a weather forecast that you can reach via Facebook, or our website, or our mobile apps, or even via twitter.  That also gives YOU the ability to choose where you get your weather forecast, and information from.  You’re not forced to watch the news to find out if it’s going to snow, or rain, or be sunny and 75°.

There is a bit of downside however…

With everyone having access to the information, we are forced to discuss whatever the weather rumor mill is discussing.  When Johnny Smith in Virginia looks at the European model and sees a major snow storm 8 days out, he shares that image on Facebook, and before you know it… everyone is buzzing about the threat of a major coastal storm 8 days away.  And after a month like we’ve had so far… talk about a major storm 7 or 8 days away, means possibly 7 or 8 days of stressing and anxiety.

So our job has become just as much about fact checking storm threats, as it is about forecasting the weather.  We’ve become the weather equivalent of  Now that is totally fine with us… we are happy to make HVW about whatever the valley needs.  And if that means you need someone to simply decipher fact from fiction… then that’s what we’ll be happy to do.

Ultimately… that’s what we’ve had to do with this latest storm threat.  We received an avalanche of questions around Wednesday or Thursday of this past week… roughly 6 to 8 days out ahead of the ‘storm’.  We say ‘storm’, because this system has never really been a real threat.  It showed up a few times on each model, always 5 to 10 days away.  Since we got inside of 5 or 6 days, the models have unified around the idea that this storm… (or storms we should say, since there are really 2 separate systems)… stays to our south.  Here’s the latest simulation on these twin storms…

You’ll notice that the first low pressure zips east, near Washington DC, and then pushes out to sea.  That could provide a swath of snow near Philadelphia, Baltimore, maybe DC… but the moisture stays well to our south, and is a non threat.  That was the “Tuesday” storm that caused such a stir… but you can see, it goes safely out to sea.

Then behind it, to the Southwest, you can see the storm that we need to pay attention to.  The jet stream will buckle and tilt negative, and a storm will try to explode along the coast… behind the first storm that went out to sea.  There is concern, that this 2nd piece of energy will have room to come up the coast… and the timing on that would be Wednesday into Wednesday night.

Now… odds still are probably 60% to 80% that the 2nd storm also passes by to our south.  But we have seen a lot of storms that look similar to this setup… make the bend and come up the coast.  So while there is currently very little guidance that says it will snow on Wednesday or Thursday… we need to keep our eyes on that system, to see if it hugs the coast.

So Tuesday is definitely looking dry (95%+ chance of the storm going out to sea)… but Wednesday could hold maybe a 20% to 30% chance of bringing us a surprise.

No matter what… it’s going to be COLD!

Now… this time of year, the average temperatures are getting warmer every day.  But the average in the Hudson Valley is only in the upper 40s to near 50° this time of year, and about 40° in the Catskills.  All week, we’ll see afternoon temperatures pinned in the 30s… struggling to reach 40° in the valley; while the Catskills may not even get above freezing.

So even if we don’t get a storm… sadly, it’s going to feel a lot like winter all week long.
We’ll keep our eyes firmly locked on the 2nd storm… and let you know if there are any surprises or changes to our thoughts.  You can get our ideas on the 5 day forecast on the main page.  Have a great Sunday Afternoon!

Saturday Discussion : Watching the Mid Week Threat

As we cruise into this mid March weekend, a cold trough has pushed into the eastern US.  That means that instead of mild temps in the 60s, like you can often see this time of year… we’re stuck with a biting NW wind and temperatures that will struggle to climb out of the 30s.

Conditions on Sunday look very similar to what we’ve got on Saturday… temps struggling to reach 40°, and wind chills in the upper 20s to low 30s.  So a blustery and cold, mid March weekend is unfolding across the Hudson Valley.

But all the chatter this weekend is about the potential for a 4th Nor’easter by mid week.  Previous guidance had periodically shown the potential for a significant snowstorm that could bring widespread snows of 6 or more inches.  But as is very often the case with these coastal storms… the computer guidance has largely lost the threat, keeping the storm to our south… and pushing it out to sea.

The setup is a complex one, but guidance has really come to a consensus around the idea that jet stream energy to our north, will be strong enough to steer this system south and out to sea. If you look at the top right of the image, you’ll notice the bright yellows and oranges, indicating a lot of energy racing from NW to SE, in the direction of the black arrow.  That strong jet stream energy will serve to push the first storm eastward… out to sea, instead of capturing the storm and pulling it up the coast.

You can see a 2nd piece of energy over Louisiana and near Texas (indicated by the orange color at the base of the trough).  That energy will try to intensify and come up the coast behind the first piece of energy… but it looks like that will also be guided well off shore on Wednesday, keeping the Hudson Valley shielded from the threats of any nor’easter.


There is plenty of time for things to change, but this kind of development in the forecast, is not one that changes easily.  The northern jet stream is quite strong, and would need to change significantly from what we’re seeing right now… in order for this coastal storm to really push north.  So if we had to put odds on the storm at this point… it would be hard to give it more than a 25% chance of hitting the Hudson Valley at this point.

Keep checking in with us, we’ll have more updates as we get closer to the storm… but for now, it’s looking like the threat of a coastal storm continues to diminish as we get more information.

Bundle up, and enjoy your Saturday!

Storm Recap 3/13/18: The 3rd Nor’easter’s a Charm

A very active March continues, as we’re only half way through the month… yet we’ve had 3 formidable nor’easters hammer various parts of the northeast.  This time, the Hudson Valley got let off easy, missing out on the heart of this latest storm.  While we saw an accumulating snowfall… by far and away the worst this storm had to offer was focused on New England.

The good news, was that this was expected all the way through.  The data suggested a New England focused storm, our forecast called for a New England centered event… and the storm cooperated and behaved as expected.  Lets look at our forecast map, followed by what actually happened…

Across the Hudson Valley, we expected to see a general 2 to 5 inches, with a few 6 or 7 inch amounts as you got closer to the NY/CT border.  Then as you went into the Catskills and eastern Taconics, we expected to see 5 to 8 inches on the average, with a few locations pushing into double digits.  When all was said and done… that was pretty close to what happened.

The highest totals were certainly the higher elevations of Ulster and Columbia counties, where the upward motion enhanced snowfall amounts just a touch.  Temperatures were pretty much near or just above freezing… making for mainly wet roads across much of the valley locations, but there were certainly some cold spots, where roads became snow covered and travel was rather treacherous.  Driving over a short distance, you could see dramatic changes in the conditions.  For example… I (Bill) travelled from Pine Bush to Middletown, Over that 10 mile trip, I went from…
– just wet roads doing 55mph on rt 302 in Pine Bush, to…
– a snow covered & icy Goshen Turnpike in Circleville, with a car off the road…
– to just wet roads in Middletown again

It was certainly a tricky day of travel, depending on your location.  But like we said, the Hudson Valley was spared the worst of the storm… with a light to moderate snowfall on average, a general 3 to 6 inches.  To experience this storm’s full potential, you needed only hop in your car, and head east 50 to 100 miles… to eastern Connecticut, Massachusetts and Rhode Island…

When we zoom out to look at all of New England, you can see that anyone east of Hartford, CT and Springfield, MA… got absolutely crushed.  The dark orange represents a widespread 12 to 18 inches of snow from Norwich, CT… to Worcester, MA… up to the southern half of Maine.  Then embedded within that large area, are pickets of 18 to 24 inches in red… with up to 30 inches of snow in the dark red areas near Manchester, New Hampshire and Bangor, Maine.  Just some jaw dropping stuff!

It’s been a WILD month of March so far, and indications are that trend will continue into the 2nd half of the month as well.  We can’t thank you enough for trusting HVW to guide you through the storm, and for helping us track the systems with real time reporting that is 2nd to none.  You all continue to make operating HVW a dream come true!  Thanks so much… and hang in there winter warriors… we’ve only got a little further to go.

Thursday Outlook : The Blustery Hype Train

I suppose that by this point in the season, everyone is just battered and beaten.  That because everyone has been assaulted by snow for so long, that every time someone hears the word ‘snow’, it causes panic and fear.  So it goes for the last 24 to 36 hours, our inbox has been a steady stream of different variations of the same question… “Did I hear that we have ANOTHER big nor’easter coming next week?”

We totally appreciate it… this month has left us wiped out and exhausted, and we’re only half way through it.  When you get 3 nor’easters in less than 2 weeks, it’s going to keep you pretty dang busy.  So when the computer models begin their usual antics, of showing a potential snow storm in the 5 to 8 day window, we’re not surprised that the panic and anxiety level quickly starts rising.

Sadly, we can’t really offer much consolation at this point, other than to say… quite simply… it’s too early to worry.  There are just WAY TOO MANY uncertainties to begin getting into details.  Here… let us show you what we mean…

Below are 2 temperature maps for early Tuesday morning.  Both maps show the same thing, the projected low temperature Monday night into Tuesday morning.  The first is the European model, the second is the GFS model…

What’s 20° to 30° difference between models?  Again, these computer models… arguably the best 2 medium range computer guidance models… are worlds apart on the overnight and early morning low temperature between Monday night and Tuesday AM.

This is even more significant, because this projection is for BEFORE the much hyped and much talked about nor’easter next week.  If the computer models can’t even get on the same page for the setup leading up to a potential big storm… how on earth can we rely on them to nail down the details on a storm system a day or two after?

The answer is… we can’t.

Now… what we CAN do, is say that the upcoming pattern favors storm development between Tuesday and Wednesday afternoon of next week.  There will be a storm system that drops down out of the Rockies, and pushes eastward, most likely into the Ohio Valley.  What happens next, is the crucial detail.

The GFS model currently takes the storm right over top of us on Tuesday, and warms the Hudson Valley into the upper 30s, giving us rain.  The European model is slower with the storm, and eventually redevelops a coastal storm on Wednesday of next week… spreading a swath of substantial snow over the region.

So we’ll have to monitor the setup, and see if the European model or the GFS model have the correct idea.  We do believe the pattern is more likely to lead to a storm pushing into the Ohio Valley, and redeveloping off the coast of Maryland or Virginia, and then pushing northeastward… which would give us snow.  So yes, we do feel that there is a good chance for another snowstorm in the Tuesday night/Wednesday time frame… but like we say… there’s a LONG way to go.

For now… just hold onto your hat, because the winds continue to howl across the Hudson Valley today.  Temps won’t make it out of the 30s for most of the valley, and with the wind gusting over 25mph out of the northwest… it’s likely the ‘real feel’ temps won’t crack out of the 20s all day.  Be sure to bundle up and stay warm… and we’ll have more updates once or twice a day as we continue to track the threat for a mid week storm next week.

Wednesday Outlook : Cold Winds Ahead

The major nor’easter that has rocked New England just clipped the Hudson Valley on Tuesday.  We’ll have the complete recap shortly… but we did see a lot of 2 to 6 inch totals across the region.  You can let us know how much snow you had in a comment at the end of this post.

But now our focus shifts from snow… to winds, and lots of wind.  You’ll notice in our 5 day forecast, that we have multiple days of “Partly cloudy and Windy”.  Well, that’s because for 4 straight days, the projected wind maps look like this:

A steady, persistent west/northwest wind will be the story for Wednesday through Saturday, as the winds really crank up in the wake of our departing nor’easter.  The large scale counter clockwise rotation around the storm that is moving into the Canadian Maritimes, will generate a very windy pattern the next 4 days.  The gusts, each day will look somewhat like this…

So be sure to hold onto your hat for sure.  A strong gust of wind could howl through on any given day and blow the papers right out of your hand, or the hat off your head.  You’ll also notice the gusts if you’re driving… so be sure to have a firm grip on the wheel.

In addition to the howling winds… the cold will be a factor…

These are your projected afternoon high temperatures across the region.  Widespread highs in the mid to upper 30s across the valley… while the Catskills don’t get above freezing in many cases.  And to add insult to injury… when you combine the cold and the wind, this is what it’s going to feel like on Wednesday:

To be honest… this is what it’s going to look like almost each of the next 4 days… so get ready for a COLD mid March pattern.  The record warmth of late February, seems light years away.

Snowfall recap map should come out shortly… Have a great day!

Final Snowstorm Forecast : Near Miss Nor’easter

Winter weather haters, thank your lucky stars… because roughly 50 to 75 miles makes all the difference between a nor’easter near miss… and a coastal storm clobbering.

– After 6pm : Scattered snow showers develop, especially in Catskills
– 10pm to 2am : Snow develops from south to north
– 11pm to 9am : Best chance for steady snow.
– 10am to 2pm : Snow or snow showers taper from west to east
– 2pm to 8pm : Scattered snow showers & squalls possible (especially in the Catskills)

Snow Accumulation:
– Catskills & Taconics (Zone 1, 2 & 4): 5 to 8 inches
– Majority of Hudson Valley (Zone 3, 5, 6, 7, 8 & 9) 2 to 5 inches


I apologize for the delay in the discussion being completed.  Non weather related responsibilities delayed the post, but enough time lost already, lets dive in.  The plus side of a delay, is that we have more information now than we had a couple hours ago.  The storm is looking potentially snowier than initially expected, as the western edge of the snow shield tries to push its way back into the Hudson Valley.

So here’s where we are as of late night…

We’re going to go through simulated radars in a moment, but this radar image is the 1st sign that the eastern half of the Hudson Valley could end up doing a bit better than forecasted in terms of snow totals.  Outlined in black is a healthy snow band, that has snowfall rates of 1/2 inch to 1 inch per hour within it.  It’s early… but this looks likely to be the western edge of the heavier snow shield.  As the storm continues, this band of snow will likely continue rotating westward… before stalling out somewhere over the Hudson Valley.

This first band of snow will moisten the atmosphere westward into the Hudson Valley, and then additional snow bands will rotate westward in behind it.  This band will be important in terms of accumulations, because it will likely show us where the heaviest snow totals will be.  From this band, and points east… are most likely to reach the forecasted snow amounts… and have the best chance to overachieve in terms of snow totals.  Because as we look forward, you’ll see that as this storm progresses forward, the snow shield will pivot over the Hudson Valley, and so where this band reaches… it will snow steadily… and likely continue to snow steadily, through the morning on Thursday.

So as we approach sunrise on Tuesday, you’ll notice that the storm is a powerful 970mb, and if this storm was 50 miles further west, the Hudson Valley would be in for a major storm.  With that said… the close up of the Hudson Valley shows moderate snows across the entire region, with the heaviest snows expected as you go further south and east.  But as we mentioned at the beginning of this discussion, that first heavier snow band rotating through will add a bit of a wild card to where the heavier snows will be with this system.  We’ll have to watch and see just where the heavier bands set up.

As we move through the morning, the snow will continue to fall light to moderately… possibly even heavy for short periods in the eastern Hudson Valley.  This snow should be heavy enough to keep road conditions rather slick and snow covered in many cases. We’ll have to see how much snow cover we get on paved surfaces… with temperatures rather close to freezing.  The AM commute could be a bit dicey as a result.

As the morning progresses, the sun will get higher in the sky… and the snow will begin to struggle to stick to the roads.  In mid March, the snow needs to fall quite hard to stick to the roads during the daylight hours.  We’re not sure that it will fall hard enough to keep the roads snow covered on Tuesday… but it’s best to play it safe, and expect snow covered roadways.  Allow extra time for your travel on Tuesday morning… especially as you go further east (where it will snow harder), and also up in elevation (where it is colder).

The snow is likely to last into the afternoon, and as we mentioned… the location of the back edge of the snow is important, because it could lead to an extended period of light to moderate snow in the HV through the afternoon…

You’ll notice that while this storm really cranks up and moves out to sea… the snow potentially could linger in the Hudson Valley into mid Afternoon.  Snow rates would be lighter most likely, and roads would likely be just wet by this point (but wait and see, we can’t assume it will be fine)… but snow could continue to accumulate on grass and unpaved surfaces.

When all is said and done… and the snow tapers off from SW to NE between 1pm and 6pm (you’ll notice it hangs on longer in the NE Hudson Valley)… snowfall amounts in the region should average 3 to 6 inches.  However… the eastern Hudson Valley, especially east of the Hudson River and north of I-84… could see 5 to 8 inches.  If the snow bands really wrap up around this storm… we could see some areas over-achieve on snow totals.  But based on current data, a widespread 2 to 5… or 3 to 6 inches look good.

We’ll have to see if we have to tweak the snowfall amounts up an inch or two, based on how these snow bands perform… which is all part of now-casting, which we’ll continue to do through the storm on Tuesday.

Be safe… and thank you for your continued support!

Preliminary Snow Forecast : Monday Night – Tuesday

Another tricky forecast ahead of us, with a coastal storm that will develop into a monster.  The trouble with monsters, is that they are always full of surprises.  And considering our location in relation to the center of the storm… things could get interesting late Monday night and Tuesday.  We’ll explain more in a minute, but lets summarize the situation as it stands now:

– After 6pm : Snow showers possible, especially in Catskills
– 12am to 6am : Light snow possible, especially east of Hudson River
– 6am to 12pm : Best chance for steady snow… highest amounts east.
– 12pm to 4pm : Snow or snow showers taper from west to east

Snow Accumulation:
– Catskills & Taconics (Zone 1, 2 & 4): 3 to 6 inches
– Majority of Hudson Valley (Zone 3, 5, 6, 7, 8 & 9) Coating to 3 inches


Even as we post this preliminary snowfall forecast, there is computer model chaos taking place behind the scenes.  Whenever you have one of these potent costal storms developing, the guidance really struggles to pinpoint where the low pressure center will develop, and where it will track.

This storm likely deepens into a powerful storm… but the storm is too far off shore to have any real impacts on our area.  It is likely that some light snow showers get thrown well NW of the storm, likely into the Catskills.  But that’s because of uplifting, and higher elevations… otherwise, the real impact from this storm is off shore.

The primary impacts are likely to be periods of light to at times moderate snow.  There could be a pocket of heavier  snow… but in general a light snow event.  The main chance for light snow is from midnight tonight, through noon on Tuesday.  Most accumulations will be on the order of 1 to 3 inches of snow, but as you go up in elevation, 3 to 6 inches can’t be ruled out.  We will need to monitor the situation for accumulations, and see if the storm’s track looks different, or if there is any potential for great snow amounts.

So as of now… this looks like a close call, but a near miss… in terms of being the 3rd major impacting storm in the Hudson Valley over the last 10 days.  But you’ll notice on the graphic above, that there’s a 20% chance the storm tracks further to the west.  After everything we’ve seen in the past 10 days, we just can’t write off the possibility of the storm unexpectedly taking a more western track.  If that should happen… and it’s a very low probability that it will… we would have to drastically increase our snowfall amounts.  Based on everything we have at this moment… that appears quite unlikely.

So we’ll continue to track things through the day Monday, and we’ll try to share any changes… or just let you know that everything appears on track.  Have a great Monday!

Major Winter Storm Recap: Wednesday 3/7/18

In the span of just 5 days, the Hudson Valley was punished by 2 major nor’easters. In their wake, these storms have left us with…
– nearly 3 feet of snow in some places…
– thousands of people without power in other places…
– and all of us with a reminder of what winter storms in the Hudson Valley can be like.

So lets take a look at the recap.  We’ll start with the map review of our “Final Snowstorm Forecast” that was issued before the storm began (not the adjusted forecast map that we put out after realizing the storm was going to take a different track).  Next is the “Snow History Map” which shows what actually fell based on a combination of reports and radar data.  Finally will be the National Weather Service Snowfall Totals, which are reported in by NWS trained spotters.

So… before we get out our mental snow shovels and begin to dig into this, in general… if we take the entire Hudson Valley together, we didn’t do too bad.  The southeastern 75% of the Hudson Valley saw 12 to 18 inches of snow on average (or more in some cases).  The northwestern 25% of the region got shorted on snowfall amounts… and we’ll discuss why in a moment.

The Big Winners

So when you look at the map, there is a broken red stripe that runs diagonally from SW to NE across the Hudson Valley.  SE Orange, NW Rockland, bits of Putnam, northern Dutchess and much of Columbia counties… all got crushed by this storm.  Monroe with 27″, Sloatsburg with 26″, Highland Mills with 24″, Hillsdale with 24″, Chatham with 23″, Orange Lake with 20″, Mahopac with 19″… all of those locations, as well as others, were under that little stripe.

The reason those areas hit the snowfall jackpot, has to do with a feature we spoke about numerous times during the forecasting phase of the storm… snowfall banding.  There was a deformation band of snow that set up on the northwest side of this storm… affectively the boundary between the moist flow of air off the ocean, and the cold, dry air on the back side of the system.  This intense band of snow formed over the SE half of the Hudson Valley during mid afternoon, and then slowly pivoted overtop of them.  Resulting in an extended, multi-hour period of snowfall rates at 2 to 3 inches per hour!

Just look at this band of snow… even as of 6:15pm!  When you start to examine where the snow totals were off the scales… it’s no secret as to why areaas like Monroe got 26 inches of snow.  This band hammered them for hours.

The Rip Off Zone

The same image above that highlights the jackpot zone, can tell you exactly where the “rip off zone” is.  The Catskills were spared the heaviest snow totals from this storm.  After initially being projected to see 18″ to 24″ of snow in our final forecast… the storm played a dirty trick on us at the last minute, which we’ll go into momentarily.  But early Wednesday morning, we realized that some big changes needed to be made in our forecast… and by 10am on Wednesday, we released a “now-cast” adjustment to our forecast… and lowered the forecast to 5 to 10 inches across the western HV.

We realized that the storm was going to take a track that would simply rob the western Hudson Valley and Catskills of the moisture we were expecting to inundate those areas.  Sometimes with these dynamic winter storms, it’s not until the storm is just beginning, that you realize a change to the forecast is necessary.  We always talk about “now-casting” during storms, and this is why it’s so vital.  “Now-casting” is the process of using observations, radar data, and actual conditions… to analyze, modify or strengthen your forecast, to provide accurate information to your viewing audience.  As a forecaster, you need to be able to analyze the data in real time, and understand whether an adjustment needs to be made… so that people have the best information possible.

That was what happened in this case.  We received information in real time, that this storm was not developing where it was expected to… and we had to make significant changes on the fly.  Adjusting a forecast from 18 to 24 inches… down to 5 to 10 inches… is a pretty massive change.  When the snow dust settled, the forecast adjustment turned out to be a good one.  Kiamesha & Glen Spey had 12″, Greenville Center 11″, Monticello & Catskill and Phoenicia had 8″… and the area in general was 6 to 12 inches at the end of the storm.

What Happened?…
“Mother Nature is the Boss, that’s what happened.”

So the next part is the fascinating part from a meteorological standpoint.  In short… the guidance was wrong.  It failed to get a good hold on where the center of low pressure was going to develop.  Let’s first take a look at the consensus guidance leading up to the storm…

Guidance had the perfect track for the Hudson Valley, with a rapidly deepening storm hugging the coast until north/central NJ, and then tracking it just south of Long Island, before heading NE toward Cape Cod.  That kind of track will cause a change over to rain in NYC and Long Island, and even into the extreme lower Hudson Valley.  But this kind of track focuses the heaviest band of snow right over the Hudson Valley… pushing a substantial amount of moisture into the HV, and then the storm pivots east, holding the heavy snow in place for many hours.  This track was primed to deposit a widespread 12 to 18 inches of snow in the Hudson Valley, and even more in the Catskills.

However, early on Wednesday morning, we saw indications that the center of low pressure was going to take a significantly different track than what guidance had suggested.  We raced to make changes to our forecast, and when all was said and done, here’s the track that the storm ACTUALLY took

Rather than track up to north/central NJ, near Asbury Park… instead, it stalled it’s northward progression around Atlantic City… before making the turn NE.  This was roughly 50 to 75 miles further south than guidance suggested.  That meant a shift of roughly 50 to 75 miles southeast in the position of heaviest snowfall.  Now, as it turns out… the eastern 2/3 of the HV still got to the forecasted amount… but that was courtesy of the deformation band that stalled out over the eastern HV, providing several hours of 2 to 3 inch per hour snowfall rates.  Anyone who was northwest of that snow band… saw substantially less snow.

The Catskills and western Hudson Valley on average saw 6 to 12 inches of snow.  That’s still a significant snowstorm by almost any standard.  But when you realize that the Catskills would have gotten 18 to 24 inches of snow, if the storm had tracked as guidance suggested… it’s a major change.  If you look at the two maps, the track the storm actually took was drastically different than what was projected just hours before the event.

This is why we always harp on the storm track being so critical.  If the track is further east or west than expected, it’s going to change the end position of the heaviest snow band… and if you live in the area being forecast… it could result in major increases or decreases to your snowfall amount the end of the day.
But it’s also why we can never be ‘certain’ about snowfall totals in a snowfall forecast.  There was no way to see this coming.  There was no data, no guidance that suggested that this storm would track 50 to 75 miles further south and east than expected.  By the time the storm was off the coast of New England, the storm was 100 to 200 miles further east than projected.  These changes happened in real time, as the storm was beginning, and all we can do is make the assessment, and modify the forecast as quickly and effectively… so you have the best information.

From a forecast perspective… we lucked out.  Because the storm still had a strong enough band of heavy snow push into the forecast area of the Hudson Valley.  It provided the 3 to 4 hours of 2 to 3 inches per hour, to get most of the viewing audience close to… or within the forecast range, to where the storm forecast was considered a success.  (Even if we had several people on Facebook yelling about how it was not snowing and the forecast was a bust… despite the fact that we told everyone the snow would not get heavy until the afternoon on Wednesday).  But our viewers in the Catskills certainly would have noticed a difference between the forecasted amounts… and what actually fell.  But hopefully, you at least understand why.

Thank you to everyone who helped us gather data through this storm.  You’re ALWAYS a tremendous help in now-casting any event.  The HVW community provides us with an endless stream of information, that gives us an advantage in forecasting any storm.  You guys are the BEST!  And now… on to the next one, as this recap was delayed because we’re trying to hammer out what will happen with the next nor’easter.  But that’s another conversation…  Thanks for the support!