Tuesday Discussion : Minimal Commute Impacts

On Monday we had highlighted the slight potential for a period of wet snow during the Tuesday AM commute. There will be an approaching frontal system on Tuesday… but we DO NOT anticipate widespread issues for the morning rush hour.

A glance at the futurecast radar map for 8am shows the main area of snow expected to be west of the Hudson Valley. A few pockets of light snow are possible around the region, especially in the Catskills… but these pockets of light snow will be scattered, and likely to be on the back end of the commute… after most of the travel to work and school is complete. So the commute for most is dry, and where snow showers do fall, we don’t expect problems (Catskills could have a few snowy spots).

Early morning (8am) temperatures in the valley will be near freezing (below freezing in the Catskills). With the main area of precipitation not arriving until mid/late morning… by that point, temps in the valley will be above freezing, and instead of wet snow… rain showers are likely for all but the higher elevations of the Catskills. Just one more chapter in the book of a non winter around the Hudson Valley.

Monday Discussion : Eyes on Tuesday AM Commute

Happy President’s Day, Hudson Valley.  A quiet start to the work week… even though many people have the day off.  Highs climb into the low 40s, under a partly cloudy sky.  Monday evening, temps will fall below freezing once again… into the mid 20s.  We’ll then see clouds increase, and then have one eye toward the Tuesday AM commute.

Futurecast Radar : Tuesday 4am to 7pm

On this particular simulation… it suggests that the temperatures from I-84 on north could be cold enough as the precipitation arrives, for wet snow to fall.  The timing would be between 5am and 8am, and if the temperatures are near or below freezing… we could have some issues on the roads.  This doesn’t look likely to be a widespread, high probability event… but its something to watch as we get closer.  Temps will be rising with a SE wind Tuesday morning… but if the timing is just right, we could see a couple hours of snowy and icy conditions for the northern half of the valley.

The elevation snow shows up fairly well on this snow map.  Temps in the valley are so marginal, maybe a slushy coating can be found… but as you go up in elevation, that’s where snow could stick if the timing of things is just right.  Once again… we’ll keep our eye on this.  Just something to make everyone aware of as a potential situation for the Tuesday AM commute.

Hope everyone has a great Monday!

Sunday Discussion : Winter Still Missing

Another rather mild, mid-February day around the region… as our snow-free winter continues.

Mostly cloudy skies with afternoon highs into the low 40s across the valley, are about 3 to 5 degrees above average.  Temps will be slightly cooler in the Catskills, but not much of a chill will be found there either.  If we look forward into the work week, temps should persist to climb into the low 40s during the afternoon… and fall into the 20s overnight.  Our next shot at precipitation arrives on Tuesday.  Temps may be cold enough for wet snow to fall at the onset of the precipitation… but most of the valley should be plain rain by late morning.

Behind the front, temps will drop again into the upper 20s to low 30s for afternoon highs for the end of the week.  But in terms of chances for accumulating snow… nothing substantial on the horizon for the next few days.  Enjoy your Sunday Afternoon!

Weekend Outlook : Cold and Dry

Happy Saturday, Hudson Valley!  We had a bitter start to the day, and not much moderation is expected this afternoon.

Cold Canadian high pressure has settled in, and the result was morning temperatures between 10 and 20 degrees below average.  Morning lows in the single digits to around 10°, made for one of the coldest mornings we’ve seen among a mild winter.  Starting out this cold will make it hard for temperatures to reach the freezing mark today.  Afternoon highs are projected to reach right around 30°, about 8 to 10 degrees below average for mid February.  So we’ll clearly need the winter weather gear.

But as the weekend progresses, the winds will shift around to the SW on Sunday, and that will see the milder air return to the region once again.  Temps should climb into the low and mid 40s on Sunday, which is about 3 to 5 degrees above average.

So while Saturday morning and Saturday was very frosty… temps will moderate this weekend, and be above average once more by the start of the work week.  By Tuesday, our next weather system will approach from the west.  The low pressure is likely to pass north of the Great Lakes, which would allow mild air into the Hudson Valley… and we all know what that means.  Snow changing to a mix of rain and snow, or plain rain showers.  Something for us to keep our eye on as we get closer…

Where will we go in the longer term?  We’ll try to take a look at that in a separate post shortly, looking at the pattern that should take us through the end of February, and into March.  Hopefully everyone has great plans for the weekend, enjoy… and stay warm!

Refreeze Tonight

Just a quick post to highlight the potential for areas of black ice tonight as temps drop below freezing, if you did see some snow and sleet today it would be best to get it cleaned up or be prepared to deal with ice for a few days… Below is tonights lows, followed by tomorrow’s high’s, as you can see there isn’t any thaw occurring over the next 48 hours… Stay warm and enjoy our two days of actual Feburary weather…

Wed PM/Thur AM Storm Update #2

Good afternoon! Hope everyone is having a tremendous day… Let’s talk about our incoming storm system, high thin clouds are already streaming into the region from SW to NE out ahead of our approaching system, this is our first early indicator of our storm, next and more invisible would be the winds have shifted out of the South and the barometric pressure is slowly beginning to fall. The overall trend in the guidance this morning has been a continuation of what we were starting to see during yesterdays update, the cold front is arriving a bit earlier and its effects are for a slightly colder solution. Let us be clear, this by no means is saying a major snowfall is upon us, but in a winter like this every inch seems significant.

Precipitation WILL still change over to plain rain across MOST of the region before morning light, the exception to this rule is the higher elevations of the Catskills where freezing rain is likely especially above 1500′ and rising through the morning. Travel conditions will vary widely by most of the regions morning commutes, there is a lot of variability in this part of the forecast. Things to consider.. surfaces are not all that cold after two days of highs around 40 degrees, that combined with a change over to moderate to heavy rainfall would lead to rapidly improving conditions. The all clear can’t be given due to the fact that colder air will linger across the northern zones and the change over in these areas may be later and closer to daybreak, some sheltered locations may see a brief period of freezing rain before change over. In short, don’t expect along your journey what you found in your driveway.

So lets get some graphics up, they tend to always help with tying together all the nerdy talk above to what’s gonna actually happen…

Above is the HRRR Model Radar Simulation for the entire event, it shows precipitation encountering the colder air and producing and onset thump of moderate to heavy snow, its duration is limited by your location, if your across southern parts of the region its a very brief period of snow. The duration goes from zero to several hours depending what exit you get off of while heading North on I87.

Above is the NAM and HRRR model projection for snowfall across the region, remember the models do not calculate for snow melt that occurs on contact with warmer surfaces, only how much would be on the ground if 100% of the QPF was to accumulate efficiently, in laymen’s terms don’t ever take a snowfall model projection verbatim, for a multitude of reasons. Only interesting differences between the NAM and the HRRR as of this afternoon is the temps at 5000′, the NAM is colder for longer and also doesn’t retreat the freezing air as far north. OK Alex, why does that matter? Well… The intensity of the precipitation will be quite heavy, this is due to impressive lift over the region, when temps at 5000′ are sub-freezing the intensity of falling snow can help cool that column of air down to the surface, this is called “Dynamic Cooling”, when this occurs you can get prolonged snowfall, notoriously missed on model guidance. This can lead to some overachieving on snowfall amounts, AGAIN nothing will make this a MAJOR storm, but an extra inch or two? Maybe..

Now let’s talk details, minus out the nerd talk, especially considering a bunch of you don’t read it and then yell that you were surprised about something…. sigh….

Timing-  

Starts- SW TO NE  Between 9:37:30 PM and 12:28:55 AM

Ends- W to E Between 10:21:44 AM and 1:12:21 PM

Accumulations- 

Green Circle- Trace amounts of snow, maybe a coating on the NW fringes, quick onset to rain with some locations seeing all rain.

North and NorthWest of Line- Coating to 3″ snowfall amounts and duration of snowfall from hour or less to four or five hours in northern most locations. Snowfall amounts will of course be the heaviest in areas that stay snow the longest.

Pink Circle- 1″-5″ of snow and a 1/4″ or more of freezing rain short duration of rainfall across terrain above 2000′.

Thats about summarizes the situation, you can tell we’re board when your getting such in-depth analysis of a coating to three inch storm…………………………….kicks a rock while staring at the ground……. alright folks, I’m out! Stay Tuned. 

Wednesday PM/Thursday Storm Update

********AS OF 9AM 2-12-20 THIS FORECAST REMAINS VALID, NO CHANGES*******

Let’s take a closer look at our next storm system, as I’m sure you’ve read in the previous updates we are once again looking at a storm track that is less than ideal for anyone looking for a pure snow event, this system will be very similar to our Sunday night storm. A good place to start the conversation is with a simulated radar projection from the 18z run of the NAM model. What we are seeing is classic warm air advection precipitation, a storm system moving to our west with its counterclockwise flow is pushing a warm front into our region, the warm air being forced up and over the colder air at the surface is all the lift the atmosphere needs to give us precipitation.

The same process that giveth snow, shall also taketh away, in what has been a weather pattern that has us feeling like Bill Murray in the movie Groundhog’s Day! The airmass in place is only marginally cold and it does not have a source of high pressure close by to help supply fresh cold air. With the storm tracking to our west the warmer air is uncontested in its mission to root out cold air and shatter the hopes of snow lovers once again. You can see this process quite well in the precipitation types on this sim radar, warm air floods in from the south, then up the valley as it spreads into every nook and topographical cranny from the lowest elevations first and slowly as the warm air fills it continues to chase the cold air, the only safe place is for the cold air to climb, it finds safety in the highest elevations of the Catskills. Even across the higher terrain subfreezing temps will only exist near the surface, at 5000 feet warm air will have already wiped any subfreezing air away from the altitude that determines our precipitation type which is why plain rain that freezes on cold surfaces is the best that even the highest peaks of the Catskills will achieve by the afternoon.

Below the radar, we have posted the surface temps for the same period as the radar, you can see the progression of the warmth and its impacted on the precipitation types across the region. We have some concerns with the potential for a prolonged period of freezing rain across the Catskills, but it appears to be limited to areas above 2000′ and climbing.

Below is the areas we have the potential to see a glazing of freezing rain, ignore the accumulation amounts as they are always overdone, focus only on the areas in pink as these areas may have icy roads to contend with on Thursday.

Timing-

Starts-Southwest to Northeast between 10PM Wednesday and 1AM Thursday

Ends- West to East between 11am Thursday and 1PM Thursday

Accumulations/Impacts/Precipitation Types-

Purple Circle- 2″-5″ of snow with freezing rain across the highest terrain.

North of the Red Line- Moderate to Heavy snow at onset, duration 2-6 hours, shortest south and longer north and higher elevations. Coating to 3″ of snow, transitions to sleet and plain rain. 

South of the Red Line- Moderate to Heavy snow and sleet at onset, duration 1-3 hours, shortest south and longer north and higher elevations. Trace to 1″ of snow and sleet, then plain rain. 

South of the Green Line- Potentially a very short period of snow or sleet, transitions to rain, duration 1 hour or less with some areas seeing only rain for entire event. 

******** Trends in todays guidance has been colder on the last three consecutive runs of the data, important to stay tuned for any changes***** 

Tuesday Forecast Discussion

With one storm behind us we don’t get much breathing time between systems with this active and progressive pattern, unfortunately the same storm track we have been seeing most of the season will continue. Tomorrow another wave of energy will round the trough and brush the region with precipitation. Precipitation will be light and scattered and temps across most of the region look toon warm to support snow, although our northern most counties and some of the higher terrain of the Catskills may have some light freezing rain and drizzle. You see those blue and red lines? those are an indicator of temps at 5000′ up in the atmosphere, the 540 line is 0 deg celsius, so as you can see the atmosphere does not have much support for frozen precipitation. What it does show is that temps at the surface may briefly support a period of freezing rain across the some of the sheltered valleys and lower elevations, although this period looks short lived and extremely localized with a cold and dreary day for most of the region.

But this active pattern isn’t done with us just yet, another storm system will begin to impact the region before daybreak on Thursday. Does anyone have any guesses on what type of weather we should expect with this next storm? Before we answer that, lets take a look at the current and all too persistent pattern we are seeing this week and many times this winter. We have marked the appox position of the current jet stream which is responsible to not only the steering of storms and their affiliated pieces of of energy, but also important boundaries between cold air and warm air. We also have brought an arrow from that jet stream down to its speed in knots, you will also noticed we have marked and area of high pressure over the Atlantic and its associated clockwise rotation, the warm air advection associated with this high pressure causes ridging in the jet stream to our south and is commonly referred to as the SE Ridge. What does this overall pattern mean? No true arctic air available, cold air that is around does not have much staying power, storms are moving quickly with no downstream blocking of the flow, in addition this pattern will tend to bring storms directly over our region or even just west of it, this track puts us on the warm sector of the counterclockwise rotation of a low pressure system. The result? Fairly progressive storms, weak in nature, snow transitioning to mixed and eventually rain, with short lulls between storm systems, make sense? So what would you expect the storm approach our region Thursday to look like? Lets take a look below..

You guessed it?!?! I guess you don’t need us anymore now…. After tomorrow Thursday after midnight comes are next period of unsettled weather. As of todays guidance it would play out with a initial burst of snow just after midnight Thursday, it would quickly transition to sleet and then plain rain across the entire region and warmer air floods into the region, with no arctic air mass in place ahead of the storm because of…. you know, the stuff we spoke about earlier, this leads to warm air having the upper hand. Still some time for changes, if the cold front is a bit faster we could see a colder, snowier or icier outcome to this system as well, so stay tuned.

Monday Update

As of 1AM on Monday our forecast remains on track and our concerns for a colder solution seem to have also been valid. Snow has overspread the entire region, we are seeing mainly snow in all locations with the exception of our southern zones where an initial onset of snow has already transitioned over to rain.

Temps are our station bottomed out to about 27° and are now creeping up as the SW flow pumps warmer air into the region. The intensity of the snow and just how long temps take to overcome the colder air will determine what exactly to expect for morning commutes. As we have been covering in detail over the last two days, the best bet is knowing that the rain/snow line will continue to spread north overnight. As it does it will first erode the cold layer from the valley floors and continue to spread north.

This will lead to generally improving morning commutes from south to north and from lowest elevations to around 2000’. Use that as your gauge for what ?? can expect I’m your neck of the woods. Once we get to mid to late morning, the combination of solar energy and rising surface temps will initiate a rapid improvement of all surfaces. The exception to the rule continues to be the higher elevations where snow will hold the longest.

The potential for snowy commutes where forecasts were generally dismissing the possibility is exactly why we wanted to get ahead of the chance that the models were under forecasting the snow accumulations, hopefully these posts will lead to a few less people being caught off guard this morning. We will be back Monday evening to look ahead to the additional winter weather threats ahead so check back!

Sunday Update (1PM Update)

Happy Sunday! Our first week of February comes to a close we have more weather to discuss. For the most part Sunday looks like a decent day across most of the region, the exception to that rule is the potential for a quick burst of snow as a piece of energy moves through the region. Given the temperatures across the lower elevations we aren’t expecting much more than quick burst or snow which will be localized, at this point the higher elevations of the Catskills have the best chance of seeing snow associated with this piece of energy.

Things begin to change Sunday overnight into Monday AM as a storm system approaching the region will begin to increase warm air advection across the region, this will spark of a shield of precipitation. It appears precipitation may fall in the form of snow across the higher terrain and across locations north of Kingston.   Temps may be to mild to support snow across the lower elevations of the valley, but we will continue to monitor. Snowfall across the highest terrain may be moderate with 2-6” possible. We will monitor the potential of accumulating snow across the lower elevations through the day.

Any snow that does fall will have the potential for creating click travel overnight and possibly impact the Monday AM commute.  Temps on Monday moderate quickly so if snow manages to make it down to lower elevations, it’s impacts will be short lived. We will have another update during the day to address some of the uncertainty with the lower elevation snow, so stay tuned.

A glance at the HRRR for just after midnight shows the area of snow in question, you can see the impacts of the lower elevations on precip type but it’s a very close call across northern parts of the region, best best is to be prepared for the potential for some slick travel but Sunday overnight and early Monday, especially across the high terrain and northern most counties

1 PM UPDATE: 

Good afternoon,

Let’s take a look at the latest guidance for a deeper look into what we can expect across the region overnight into Monday morning. Things still look quite aligned with the above information lets first take a look at the HRRR model which does not take us through the entire event but continue’s to be the coldest of the guidance.

This simulated radar take us through about 5AM, as you can see this piece of guidance is depicting a not so great scenario for early morning commutes, dynamic cooling from moderate to heavy snowfall allows for a prolonged period of snow across all but our southern most zones, this option has been and continues to be on the table, an we will need to monitor tonights guidance for any trends towards or away from this scenario.

The other end of the guidance is coming from the NAM model below, this model is a bit warmer and very much less aggressive on the snow vs rain across the lower elevations. Snow moves in after midnight and quickly begins to transition to rain, even during the onset of snow surface temps are above freezing, any early road accumulations will rapidly improve as soon as the precipitation transitions, this scenario would be the better outcome for all morning activities outside of the higher elevations. Next image is temps during this time frame, you can see warm air relentlessly pouring into the region throughout the event, these are not the temperature profiles you want to see for accumulating snowfall.

Sooooo you may be asking, how is it going to snow at all? I can answer that! Temperatures in the upper atmosphere are supportive of snow for quite a bit longer than the surface, this combined with moderate precipitation intensity is enough to cool the column down, this combined with the cold nights we’ve had the last 48 hours and this occurring pre sunrise means we can likely overcome the air temps slightly above freezing and still have some ice and snow covered roads for a period of time before things rapidly improve.

Take a look at temps at about 5000 feet..  Below 0c is supportive of snow…

Feeling is a blend of these two scenarios, for one we haven’t seen many storms this season end up on the colder side of the guidance, if anything its been quite the opposite, that alone means we must be apprehensive of the coldest guidance. It’s important to leave that option on the table given the importance of Monday AM travel. No matter what, this doesn’t appear to be much of an accumulating snowfall event anywhere outside of the higher elevations of the Catskills, above 2000′ we could see 3-6″ of snow with amounts increasing with sea level. This all wraps up by about 10AM-1pm tomorrow, temps really spike as the day progresses so any evidence of winters early morning shenanigans will be quickly erased.

In closing, higher elevations be prepared for an accumulating snowfall event with moderate impacts to travel, lower elevations south of Kingston, a brief period of wintry weather is probable prior to daybreak but conditions improve rapidly as warmer air rushes in, northern half the region may see these wintry conditions hold on a bit longer along with the impacts. Any trends warmer or colder will have equal and opposite impacts to the forecast and its impacts. Stay Tuned….