Our surface temps are on the warmer sides and therefore the milder outcome is likely with the inbound precipitation. Light rain will be the primary precipitation type for a good portion of the region, but a period of wet snow is possible across some of our elevated terrain, along with some scattered areas of sleet or snow especially at the onset of precipitation, with warm surfaces this shouldn’t amount to much outside the higher terrain. Some of this light snow may linger for the duration of the event but only above 2000’ in the Catskills. We may also see some snow linger for a few hours across the higher terrain of Eastern Columbia County. Precipitation clears most of the region by late morning to midday, although some rain may linger across some of our southern most zones into the early afternoon. Attached is the HRRR projected radar for 8pm showing some areas of higher terrain kicking off the event with some wet snow and the second image showing 2am, warm air will clearly win the battle with snow only lingering across the highest terrain.
Storm system will bring snow, freezing rain and rain to the region late Thursday into Friday AM. As mentioned in our previous update, a storm system will be responsible for a southerly flow that will help to advect warm moist air into the region, this will help trigger precipitation and also milder temps.
For a large portion of the region this will start and end as plain rain, across some of the northern counties it may start as rain and turn over to a period of snow on Thursday evening before warmer air aloft finally winds the battle and changes precip back to rain. This period of snow looks to be brief with accumulations from a coating to maybe an inch across some of the northwestern hill towns. The exception to this rule will be across the higher terrain of the Catskills, specifically above 1500’ where snow may persist longer with accumulations of 1-3” and even higher across the peaks and ridges above 2500’.
The low confidence and always dangerous factor that we need to continue to monitor is the chance for some freezing rain late tomorrow. The NAM model suggests that some scattered freezing drizzle could break out across the region as early as Thursday evening from about 5pm on, with the highest threat being west of the river and across the higher terrain. We don’t like to ignore even the remote chance of freezing rain during commute periods as the lightest glazing of ice can create travel issues. The reason for the low confidence is the other piece of short range guidance the HRRR is much milder and has very little threat of freezing rain and is significantly less coverage on the snow threat as well. Please factor this potential in to your day tomorrow.
The storm departs the region between 5-7AM Friday morning with colder air arriving in its wake for the weekend. Attached are three images, first image is the NAM projection for where freezing rain may fall and how much, this is likely over done as the models have a tendency to over forecast ice accretion. Second is the NaM projected snowfall, as you can see this is mostly confined to hill towns and higher elevations and the northern half of our forecast region. Lastly the projected radar image for after midnight Friday, this showing that warm air has surged northward, and snow by that point is confined to the higher elevations of the Catskills.
We will pour over the the overnight data and again the morning data and have a better idea of where if any the highest risk for icing may occur, as of this evening this is the best idea of areas to be aware of the risk.
Our decent stretch of mid February weather continues through most of the week ahead of our next weather maker which arrives overnight Thursday into Friday. As you can see from the below image, temps through the next few days will be right around average for mid February which is by no means warm. This works out to be highs right around 30°-36° and lows in the mid 20’s.
So what about this next system? Snow lovers rejoice? As we have seen quite often this winter, our waves of cold air are quite transient and lack the high latitude blocking and polar vortex disruptions required for sustaining cold. With that said, the current pattern will bring a low pressure to our north and its associated cold front being responsible for our precipitation. This track will lead to warm air advection out ahead of it, with temps surging back above normal just in time for our precipitation to arrive. As seen in the below image, temps by Friday morning will be about 8-10° above normal.
The result…. more wet than white across the region, although there is some disagreement between the GFS and EURO in terms of some snow at the onset, neither model poses any widespread snowfall. Here’s a look at both the EURO and GFS for Friday morning around 1AM.
As you can see the GFS model like a bit snowier of a start to the precipitation and the Euro is leaning warming with mixed precipitation across the higher elevations changing to rain. Despite the colder start and nuances between the models at 4+ days out, the output it very similar, all precipitation is rain by morning, and any frozen precipitation that does falls looks minimal and confined to higher elevations. Here is the GFS and Euro total snowfall projection for the next system.
Meh… we will of course monitor the data as we get closer to pin down the time frame for any potential frozen precipitation and where. In the wake of this system and the FROPA (Frontal Passage) it appears another shot of below normal air arrives across the region for the weekend. Once again, there will not be a storm to meet up with this colder airmass, so we should expect the usual, some squalls off the lakes and scattered flurries with gusty NW winds.
Looking even beyond this period, next week looks like a similar pattern with more frontal passages, with seesaw temps as warm pacific air continues to flood the country and keep cold air masses simply passing through. If you’re looking for a big snowstorm, I don’t see anything in the 7-10 day time frame worth getting excited about. We are running out of runway to make something happen, the next target period would be the first 10-14 days of March. Bill may just drive to Florida this week, as he is considering setting up a blockade to thwart the arrival of spring, or at-least hand deliver a strongly worded letter. So if the pattern suddenly becomes conducive for snow, blame Bill.
Hope everyone has a great week!
A low pressure system passing well to our south will spread light to potentially moderate precipitation into the region. Precipitation looks to break out after midnight and may become moderate across our southern most counties by Saturday morning. Light snow and snow showers may linger into the mid afternoon before tapering off. There has been a touch of a northern trend on this storm this morning, with the region being on the northern fringe of this system, its impacts will be heavily dependent on where the final track settles. A coating to 3 inches is possible with very little north and a gradually increasing probability as heading further south. The best chances of seeing more than an inch of snow would be south of i84 and even more so across Rockland and Westchester counties. We will monitor the days data and update again this evening with additional thoughts, otherwise factor this potential into your plans.
Gusty winds behind our departing clipper this morning, winds have already been observered between 30-50 MPH across the region. This has led to some outages across the region, please be mindful of down wires and debris on roadways this morning. Winds will remain gusty with the worst of the winds between now and noon, after which we will begin to see a gradual reduction is maximum wind gusts, most of the winds will subside between 4-7PM. On the “Storm Center” portion of our page you will find the StormPact image, this is issued in collaboration with Central Hudson prior to any event that may cause outages, currently isolated outages were and continue to be expected. Be careful out there and hold onto your hats!
Throughout the tracking and forecast of this storm… we talked about the sharp cutoff between heavy snow… and no snow at all. Well… the numbers are now in, and it’s visually stunning.
Now, this map isn’t perfect… because the level of detail required to properly capture this kind of gradient is beyond our current tool kit. But we can still paint a very vivid picture displaying the wide range of 6 to 12 inches of heavy snow… and just a few miles away… less than an inch. Here’s a closeup, with the National Weather Service snowfall totals.
In just under 30 miles, is a difference of nearly 10 inches of snow. Rosendale, NY got 0.8″ of snow, and Newburgh, NY (Stewart Airport) received 10.4″. Plattekill recorded 8.7″ of snow… just 18.5 miles away from Rosendale. There were very few reports between 1 and 5 inches of snow… with the majority of the reports exceeding 7 inches of snow, or being less than 1 inch. The reason for this was just as we discussed… sinking air on the northwest side of the storm drying the air and stopping the northward push of the heavy snow band. Then, the moisture piled up against the south side of the “invisible snow force field”, resulting in a very short distance between cloudy skies and heavy snow rates of 2″ per hour. Goshen reported 10.6″ of snow in central Orange County, and less than 35 miles to the north, just 1 inch of snow in Kerhonkson.
With such a tiny margin of error, predicting exactly where this boundary would be was a very difficult.
In the end, we were close, but placed the boundary too far to the south. We have several forecasting tools to help us try and locate this boundary, and the tool we used in this case was the NAM model, that had the boundary even further south than our forecast…
This tool is a great resource, and usually very accurate. The HRRR model looked very similar in this timeframe, and we’ve seen storms in the past with a similar setup, that these two models performed admirably. This time however, they were a bit too aggressive with the push of dry air from the north. Instead, of no snow falling along the I-84 corridor as the NAM computer guidance suggested just 12 hours prior to the event… a foot of snow fell from Newburgh, to Montgomery, to Middletown, down to Warwick, and back up to Monroe.
We did our best to communicate that this would be a game of inches… where the precise position of the boundary would have a dramatic impact on what you saw in your location. So when we shifted from our original 6 to 12 inch forecast…
… to our updated final forecast, we hope you understand why we had to make that change. Because sure… those along I-84… who were in the 6 to 12 inch range… ended up with 6 to 12 inches. But Kingston, Saugerties, Monticello, Hudson and Rhinebeck… who were also in the 6 to 12 inch forecast…. all ended up seeing less than an inch of snow. We correctly identified that a major shift in the storm impact was coming… we just pushed the boundary about 30 miles too far southeast. And as we saw… 30 miles was the difference between all or nothing with this storm…
The lower half of the Hudson Valley has received a blanket of fresh snowfall… while the upper half of the region is left wondering what all the fuss is about. Where the snow fell today, please be alert to the potential of a refreeze. Several inches of snow, followed by temperatures in the mid 30s, has allowed for some of that snow to melt this afternoon. But as the sun sets, the heat source disappears… and temperatures will quickly fall back below freezing by 7pm…
As the temperatures fall, the wet pavement and puddles will quickly refreeze, and result in black ice on paved surfaces that is very hard to see. Treated roadways should be ok, but side roads, walkways, driveways… those surfaces could be quite slick in some spots. Please make sure to use caution travelling tonight.
Beware of Sharp Objects
The combination of the weaker storm system, slightly further south track… and the dry air on the northwest side of this storm, resulted in a very sharp cutoff on the northwest side of this storm system. We discussed in the forecast that the potential existed for an intensely sharp gradient of snow, and while the data is still rolling in… so far, it appears as if that super sharp gradient is exactly what we saw…
The totals out of Orange County are registering between 8″ and 12″!! Then across the border in central Ulster County about 20 miles away… it’s a coating to 3 inches… and then by the time you get to Kingston, nothing at all. The sinking air just to the north of the snow band resulted in a very sharp cutoff… while precipitation piled up against what amounted to an ‘invisible wall’ of sinking air. So where the snow fell… it fell extremely hard for 8 hours. But as soon as you were on the other side of that dry air boundary line, the snow never fell at all.
This was exactly what we were trying to highlight Monday afternoon & evening… because the chances we pinpointed that line exactly, were very small. We went with guidance that pushed that line into the southern part of Orange and Putnam counties, and pushed our 5 to 10 inch snowfall from that point south. South of Monticello and Poughkeepsie… you’re saying “why did they adjust their forecast??” But north of those locations, you know exactly why we made the adjustment. That’s why our forecast discussions can be a bit more complicated… because we try to explain the details factoring into our forecast. This way if you understand the setup… when you see you’re in the 2″ to 6″ adjusted forecast range, you also understand that you need to be prepared for 6 to 12 inches… because if that northern edge climbs further north, you’re going to be seeing the full brunt of this storm. Mother Nature is a complicated creature… more on the recap soon!
Forecast is evolving as expected with a sharp northern cutoff, we have nothing but cloudy skies across the northern most parts of the region. Across the mid portions of the region we have flurries or light snow that only started with the last hour or so. As you head further south accumulations increase, we’ve seen many reports of 6”+ in some locations. It was projected that banding would set up somewhere north or along i84 and that would result in higher than forecasted amounts, that has verified. These bands are notoriously difficult to pinpoint and with snowfall rates of 1-2” per hour they can literally make or break a forecast. Generally these bands occur north of what models project, this is why we pinpointed these locations for having the boom potential. This is a fairly progressive storm, with 8-10 hours of snowfall, if there was blocking in place and this storm was moving tighter to the coast and slower, it would be a historic winter storm. Snowfall looks to end from NW to SE between 10Am and 1pm, not before an additional 3-6” may fall. Attached is the additional snowfall expected between 8am and end of storm, based on current observations and this data, we should see some locations in the 10-12”+ range by this afternoon. As stated in the headline it’s a story of feast or famine, with a near 10 miles being the difference between a coating of snow or several inches. Remember storms don’t follow lines on snow maps, this is a big region and it’s a game of getting close to the target areas. There will always be winners and losers, depending on how you feel about snow will determine where you fall on that scale.