Preliminary Storm Forecast : Friday 3/2/18

Warm air is entrenched over the eastern half of the United States.  The Hudson Valley has been a solid 10° to 15° above average all week so far.  So that fact that we’re about to talk about discuss the likelihood for a snowstorm on Friday may seem a bit hard to believe.  But a dynamic upper level low pressure system will interact with rapidly intensifying nor’easter.  The timing will be crucial… but the expectation is that a sizeable snowstorm will impact the Hudson Valley on Friday.

Timing:
– 8pm to 11pm Thursday: Rain develops from SW to NE
– 12am to 7am Friday: Rain mixes with & changes to wet snow from NW to SE
– 7am to 4pm Friday:  Snow falls moderate to heavy at times
– 6pm to 11pm Friday: Snow tapers off from west to east

Snow Accumulation:
– Catskills (Zone 1 & 2): 10 to 18 inches
– Southern Catskills, Shawangunks, Hurley Highlands (zone 5 & 6): 6 to 12 inches
– Majority of the Hudson Valley (Zone 3, 4, 7 & 8): 4 to 8 inches
– Extreme Lower Hudson Valley (Zone 9): 2 to 5 inches

Discussion:

In the midst of a very warm pattern, we are going to witness the power of an upper low pressure system, as it single handedly tries to cool the region substantially enough to take temperatures in the mid 50s… and turn them into temperatures in the mid 30s in 24 hours.  There is no arctic cold front, no source of cold… Canadian air.  If it’s going to snow… and we believe that it will… it’s going to do so under the power of a strong area of upper level low pressure.

This map shows the upward motion in the atmosphere.  There is projected to be a very large area of strong to intense upward motion just to the north of the upper low.  As a result, we should see rapidly cooling air temperatures, and moderate to heavy precipitation.  The entire logic behind this storm being a snow maker for the Hudson Valley… is that the tremendous upward motion is THE ingredient that cools the air mass enough to support snow.

This shows the projection by the European model, for temperatures at cloud level (in degrees Celsius).  With the progression of the Upper Level Low pressure eastward Thursday night into Friday morning… you can see that the cloud level temperatures are projected to respond in kind.  At sunset on Thursday, cloud level temperatures are above freezing in the Hudson Valley (star)… but by sunrise on Friday, cloud level (850mb) temperatures are projected to be below freezing (white color).

If this scenario is correct… and we believe that the European & NAM model solutions have the right idea… by sunrise on Friday… a moderate to heavy snow is expected to be falling across the Hudson Valley.

Based on the factors we’ve laid out… this is what the weather map could look like Friday morning.  It would set the stage for a very snowy Friday across the Hudson Valley.

Important Notes

This is an extremely complex setup, and all the pieces of the puzzle need to come together just right, for us to see snow.  If any of the factors change… it could have major implications on the end result of our weather.  Here are a couple of extra items we want to highlight related to this storm and forecast…

… The track of the upper level low pressure is critical.  It needs to track just to our south, but not too far to our south.  This is how we’re going to get our cold air, and if the upper level low is too far away, the influence of cold air will not take hold.

… Temperatures are extremely marginal… meaning near or above freezing through the duration of this event.  That will mean variations in accumulations.  Snow could struggle to stick to paved surfaces, and even on grassy areas.  So travel conditions will vary across the region.

… The data we’re seeing remains VERY conflicted at this time.  The uncertainty level with this forecast is VERY HIGH.  We are talking about a very dynamic situation.  Upper level low pressures are notoriously difficult to forecast, only adding to the uncertainty level.

… There is a STRONG block over Greenland at this time.  That will prevent this storm (rain or snow) from exiting the area quickly.  The result will be the storm getting trapped just offshore on Friday, and for the Hudson Valley and Northeast US, it means an extended period of snow (or rain)… possibly leading to very high accumulations of snow in some places (especially the mountains like the Catskills).

BOMBOGENESIS!  This storm is projected to go from 1001mb at 7pm Thursday to 971mb at 7pm Friday night.  When a storm’s central pressure drops by more than 24mb in 24 hours… the storm is said to have “bombed out” or undergone Bombogenesis.  This is another indicator of just how dynamic and powerful this storm is.

… Thanks to Bombogenesis… we’ll have very strong winds.  We’re seeing indications that sustained winds between 10 and 15mph are possible, with frequent gusts over 30mph possible.  There is a high wind watch for Westchester County, and if this storm transitions to snow as the Euro and NAM models suggest… we could see Blizzard Watches posted, or blizzard conditions experienced in some parts of the area.

… Power Outages?  Sadly… when dealing with potential blizzard conditions, due to such strong wind gusts… power outages may become a concern.  Temperatures will be mild, barely getting to the point where snow can be supported by the atmosphere.  With temperatures relatively mild, we’ll be looking at a heavy, wet snow.  When we combine wet snow and wind gusts over 30mph… we could see elevated concerns about downed tree branches and power lines.

… And Finally…WE ARE EXTREME!!… we anticipate our forecast to ruffle a lot of feathers.  To our knowledge, nobody is forecasting anything close to the snowfall map we have issued.  The National Weather Service has Winter Storm Watches posted for the Catskills, but the valleys are not projected to see much if any snow by other outlets.  You don’t have to agree with our forecast… but we would appreciate criticism be constructive.  We’re not issuing this forecast lightly… we see considerable data that supports our ideas.  We are trying to get our viewers out ahead of what will likely be a rapidly developing situation on Thursday… as more data comes out.  We do not hype storms to cause panic and worry… this storm has dynamic elements that could lead to unusual and extreme weather.

So in conclusion… there are A LAUNDRY LIST of complex items surrounding this storm and it’s forecast.  Expect there to be substantial changes to our final forecast.  We could see a scenario where we have to increase the snowfall forecast for the entire Hudson Valley… and we could also envision a scenario where the snowfall forecast gets reduced substantially.  We will have updates through the day on Thursday, as more and more data becomes available.

Thank you for reading… and we greatly appreciate all of your support!

Wednesday Outlook : Beautiful Weather / Eyes on Friday

A fantastic Wednesday shaping up across the Hudson Valley.  We’ll see sunshine and blue skies mixing with some fair weather clouds at times.  Our flow will shift out of the southwest on Wednesday… allowing temperatures to climb into the mid and upper 50s across the region.

The focus of the day will be on Friday of course… as we continue to track a surface storm system that will move from the Chicago area and redevelop south of NYC and Long Island.  At the same time, an upper level low pressure system will intensify and track from Detroit to areas off the Mid Atlantic coast.   The exact track will be tough to iron out, as we have multiple weather features to gather data on.

It’s warm… VERY warm, across the Hudson Valley.  Without any real invasion of arctic air to speak of… it’s going to take the energy from the upper level low pressure to generate cold enough air to cause snow.  In the Catskills… that looks easy enough, with Winter Storm Watches already posted for the mountains of the viewing area.  But the big question we’re going to focus on today:  “Can we get the Upper Level Low Pressure to track just to our south, and cool the air enough in the valley, to turn the rain over to snow?”

We’ll have updates on this potential through the day.

Rainfall Recap : Last Weekend

We’ve had many people ask for a recap on the weekend’s rainfall totals.  The reports out of the northern half of the Hudson Valley were not very encouraging (Greene, Columbia, Ulster & Dutchess).  But we wanted to share the information with you.  The map below covers the 7 day period from Tuesday 2/20 thru Tuesday 2/27… which encompasses all of the rain (and wet snow), from Thursday through Sunday.  The totals listed, are just from Saturday and Sunday.  All data is from the National Weather Service…

 

Thank you for your continued support of HVW!

Tuesday Outlook : Almost Early Springlike

It’s starting to feel like the very beginning of spring.  Those days where the sun is bright, and the temperatures climb into the low 50s.  And you can start to feel spring in the air.  Days like yesterday, and today…

We’ve got lots of sunshine and blue skies for our Tuesday.  Our flow continues to be out of the west, reinforcing that mild air that is in place across the Hudson Valley.  Temperatures started out near or just below freezing across the area… signs of a hard frost and freeze in many places.  But the sun has melted the frost… and temps are on their way up.  Highs this afternoon should reach the mid 50s in many parts of the Hudson Valley… well above the average in the low 40s.  Hopefully you can get out and enjoy our early spring preview!

This fantastic weather will carry us through Wednesday, before some more clouds push into the area for Thursday.  That leads us to a very complex setup for Thursday night and Friday.

This continues to be the basic setup for our Friday.  However, this isn’t a ‘basic’ system… and we’re getting some new data that suggests that this storm may try to generate some snow.  So we’re going to be looking at this storm in depth through the day.  We’re going to try and have a comprehensive discussion on this system later today or tonight.

Winter… it seems, won’t go away without a fight.  Have a great Tuesday!

Monday Outlook : Mild Week Shaping Up

As we begin the final week of February, winter seems to have forgotten us.  We watched winter surge back in on the heels of the warmest February day on record… but just as quickly it exited the region over the weekend once again.  After several inches of rainfall over the weekend, we’re looking at things finally quieting down for the first half of the work week.

Clouds will mix with increasing amounts of sunshine as the day progresses on Monday.  Our flow is out of the west/northwest… but for snow lovers, the problem is that there is no cold air anywhere in the eastern 2/3 of North America.

So even with the NW flow to start the week, we’ll see temperatures about 5 to 10 degrees above average… with highs across the Hudson Valley pushing near 50°.  This trend will continue as we push into Tuesday and Wednesday as well.  So a warm finish to what has been a rather warm month of February.

Looking toward the end of the week, we’re tracking a major storm system developing.  All the ingredients for a major snowstorm are in place… except the cold air.  To torment snow lovers… we’ve had a terrible atmospheric pattern for weeks, and now the pattern breaks in our favor… but with absolutely no cold air to work with.  The result… looks like this…

As snow lovers… this is deflating.  But we can’t control the weather… we just diagnose and forecast it.  It looks like a strong coastal storm will stall out off the east coast, and eventually move southeast… out to sea.  That’s due to a monster block over Greenland, that will prevent the storm from exiting in it’s traditional pattern.

We’ll continue to track this storm as we push into the week.  Maybe we can find some cold air… or borrow some from our friends in Europe.  Ultimately, that’s where all the cold is… Europe.  The US maintains our relatively warm pattern… and we’ll see how long into March we can hold onto it.

Have a great start to your week!

Soggy and Saturated Sunday Outlook

As we begin our Sunday, we’re going to try and wrap up what’s been a very unsettled 4 day period.  No sooner did we have arguably the nicest February day on record (it surely was the warmest on record)… we ran into sleet and snow on Thursday, and haven’t been able to shake the unsettled weather since.

8AM RADAR SNAPSHOT

But looking at the radar loop as of 8am… you can immediately see, that we still have got a LOT of rain to get through today. This is a radar loop from roughly 6:30am to 8am of Pennsylvania and much of southern NY state (The Hudson Valley is in the top right of the graphic). There is a good batch of light to moderate rain over the Hudson Valley, and extending all the way up to Albany… there have even been some reports of sleet mixing in with the rain over the northern Hudson Valley.

But notice how much rain remains off to our west, and it’s pushing in our direction. So it looks like we’ll be saddled with the rain straight through lunch… before the rain tapers to scattered showers this afternoon. Temps aren’t looking too good either… as it seems we’ll be stuck in the mid 30s to low 40s for much of the day. So it will be a chilly, wet and raw morning across the region… with rain tapering off around mid day, and leaving us with some scattered afternoon showers, under mostly cloudy skies.

Grab your rain coat, and have a great Sunday!

 

Winter Storm Recap : Thursday 2/22/18

It’s been a pretty wild week of weather.  We started with a snowstorm last Saturday in the midst of a mild pattern… and then ran back to back days of record breaking warmth on Tuesday and Wednesday… with Wednesday being the warmest February day on record.  Then Thursday rolled around… and much of the Hudson Valley went from mid 70s and sun… to mid 30s and snow, in 24 hours.

Lets take a look at our storm forecast, the storm history map, and the NWS reports…

Thursday’s event was expected to be focused on the northern half of the Hudson Valley, and that turned out to be the case.  In fact, when we looked for snow/sleet data for the southern half of the Hudson Valley, there were no reports at all for areas near/south of I-84.

The storm behaved well, at least in terms of what the forecast had outlined.  The system started off as widespread showers on Thursday morning, as the cold front began to filter the cold air into the region.  Rain mixed with sleet and quickly turned to snow in the northern Hudson Valley… but the abnormally warm air mass that was being pushed out of the area was so mild, that despite the rapid change to snow… the snow did not immediately accumulate in northern HV and Catskills.  Before too long, the surfaces cooled enough, and the snow began to accumulate.

For the Mid Hudson Valley, the rain showers held on a bit longer.  The forecast reflected a widespread slushy coating to an inch of accumulation, largely because the cold air would take a bit longer to push into the lower portions of the region… and it was a bit uncertain how long it would take for a transition to sleet in that area.  Eventually there was a transition to sleet and wet snow, and slushy coatings to half inch / inch amounts did occur.

The timing of the event for the evening commute was a big factor to the ‘storm’.  This was more of an area of precipitation that pushed overtop of some fresh cold air… than an actual storm system, but that’s focusing on the meteorology of the storm.  Impact wise, we were concerned that the expected burst of snow and sleet could cause some travel problems for the evening commute, and it seems like there were a few in the northern HV… while the southern HV remained just wet, with everything melting on contact.

Anytime you drop 40 degrees in 24 hours, and then have it snow or sleet in the process… it’s a pretty wild situation.  And despite the marginally low totals on Thursday… the event was a pretty wild one.  Thanks for all your support!

Saturday Afternoon Discussion – Bring on the Rain

With warm SW winds helping temperatures climb into the mid and upper 40s across the Hudson Valley, the raw chill of the past few days has been lifted out of the valley.

However, a rather large batch of rain has formed over Pennsylvania, and it’s now entering the Hudson Valley as of mid day. This batch of rain is rather large, and will bring periods of rain showers to the entire Hudson Valley for much of the afternoon. The heaviest and steadiest showers should be focused from I-84 on north. Unfortunately, anyone with outdoor plans for our Saturday will need to factor this into their plans.

This batch of rains showers will persist through the afternoon hours and likely through sunset. We likely will dry out for a few hours from sunset through midnight… before another larger batch of steady, light to moderate rain, pushes back into the region. So a very soggy start to Sunday appears likely at this time. We’ll try to share radar updates through the afternoon as well.

As we move through a very unsettled pattern across the eastern US over the next 24 to 36 hours… if you’re trying to make plans, it’s safe to expect many periods of on and off rainfall. Stay dry, and have a nice afternoon!

Friday Outlook : Gray with PM Showers

A quick return to winter across the Hudson Valley on Thursday, as we saw temperatures drop about 40° in 24 hours.  We’ll have a recap on the Thursday snow & sleet event tonight.

But today has started off cloudy and gray… with some areas of light drizzle and fog.  As we move into the afternoon, we’ll have some areas of light rain pushing into the Hudson Valley…

 

Temperatures will hold down in the low to mid 30s through much of the morning and early afternoon on Friday.  When the precipitation moves in, we should see it fall as scattered light rain showers.  It’s possible that we see some patchy areas of freezing drizzle in the sheltered valleys of the Catskills… but in general temps will be just above freezing.

The rain showers will continue through sunset… and then taper off after dark… and temperatures will likely climb near 40° overnight.  As we look to the weekend, a very unsettled weekend heading our way.  Clouds will be with us Saturday, and then some showers look to move in late in the day and at night on Saturday.  Then, it looks like we’ll have a period of rain Saturday night, lasting into Sunday morning.

So while the weekend won’t feature a total washout… there will be multiple periods of rain to contend with.  At least we’re not in a drought situation.  For a better timeline on the precipitation, check the Detailed HVW 5 Day Forecast.  We want to emphasize that Saturday during the day looks mainly dry… with scattered showers approaching near or after sunset.

TGIF everyone!

Final Storm Forecast : Thursday Sleet & Snow

Timing:
– 7am to 12pm: Spotty light sleet pellets and scattered light rain showers
– 12pm to 3pm: Steady sleet and wet snow develops from west to east (Lower HV: mixed with rain)
– 5pm to 7pm: Sleet and wet snow taper off from west to east

Snow & Sleet Accumulation:
– Catskills (zone 1 & 2) : 2 to 5 inches of snow
– Southern Catskills, Upper HV (zones 5&6, upper 3&4) : 1 to 3 inches of snow and sleet
– Middle and Lower Hudson Valley (zones 7&8, low 3&4) : Coating to 1 inch of sleet and wet snow
– Extreme Lower HV (zone 9) : some patchy icy spots / coating of sleet due to mix sleet & rain

Discussion

One day after the warmest February day on record… the cold air continues to race southward, sinking into the Hudson Valley.  The moisture is on the doorstep, and is beginning to push into the Hudson Valley in the form of light rain showers, mixed with some sleet pellets.  This simulated radar loop shows what is expected between 10am and 7pm tonight…

SIMULATED RADAR LOOP: 10AM – 7PM

You’ll notice this is a small system, and is only in the Hudson Valley for about 6 to 8 hours.  We’ll take analyze some still frames in a moment, but in the loop, we want you to notice that the precipitation starts as a mix of sleet and light rain during the late morning and early afternoon hours… before the sleet (purple) and snow (blue) begin to sink further to the south.

So the progression of this storm for most of us… is:
– starts as mix of sleet and rain… changes to sleet… then mixes and changes to snow

The big key to the weather you see in your area… is your location.  The further north you are in the Hudson Valley, the earlier the transition to sleet and snow… and then just plain snow.  The further south you are… the longer it will take for the rain to mix with and change to sleet… and possibly ending as a brief period of wet snow.  So lets look at a few snapshots of the simulated radar…

by 2pm, you’ll notice that the HRRR model suggests that the sleet is just north of the I-84 corridor, with Newburgh and Middletown in a plain cold rain.  We would not get too hung up on the exact placement of this sleet/rain line, as this model could struggle a bit with temperatures as they fall this afternoon.  The sleet line could push a little further south by 2pm… we’ll have to wait and see.

Regardless of the exact placement and timing of the rain/sleet/snow line… what we do know, is that it will be pushing south through the afternoon.  And by 5pm… much of the Hudson Valley is likely to be seeing moderately falling sleet and/or snow…

 

Temperatures at the evening commute are likely to range between 30° and 34°.  So just how much sleet and snow accumulates on the roads remains a bit uncertain… but we would err on the side of caution.  The sleet and snow are likely to be falling moderately, which will cause reduced visibilities… and as you go further north in the valley… the worse the travel conditions are likely to be.

Plan on leaving yourself a little extra time for the evening commute.  As your hitting the roads this evening, this is what the projected snowfall map is looking like…

You can see that the valley areas are mainly under 1 inch of snow… with some sleet likely mixing in.  You have to go into the Catskills and northern HV before you get the 1 to 3 inch amounts (represented by the blue colors) on this map.

This IS NOT a major winter storm… but the fact that it is on the heels of the warmest February day on record, makes it a significant event, because the conditions will be a dramatic shock to the system… and many people may not be prepared for winter weather conditions, after sunshine and 75 degrees just 24 hours ago.

We’ll have additional updates on Facebook as the situation unfolds… thank you for all your support!!

Preliminary Storm Forecast : Thursday Sleet & Snow

This winter has been a wild one, in terms of ups and downs… and unexpected weather events.  So it makes perfect sense, that one day after the warmest February day on record… it’s going to sleet or snow.

Timing:
– 7am to 12pm: Spotty light sleet pellets and light drizzle falls in some areas
– 12pm to 3pm: Steady Sleet and wet snow develops from west to east
– 4pm to 7pm: Sleet and wet snow taper off from west to east

Snow & Sleet Accumulation:
– Catskills (zone 1 & 2) : 2 to 5 inches of snow
– Southern Catskills, Upper HV (zones 5&6, upper 3&4) : 1 to 3 inches of snow and sleet
– Middle and Lower Hudson Valley (zones 7&8, low 3&4) : Coating to 1 inch of sleet and wet snow
– Extreme Lower HV (zone 9) : some patchy icy spots due to sleet & rain

Discussion:

After the warmest February day in recorded history for the Hudson Valley, we’ll have a cold front slide through the region Wednesday night.  It will shift our winds around out of the north, and gradually lead to falling temperatures overnight.  Temperatures will stay above freezing all night, and when we wake up… temps will likely be in the mid to upper 30s…

It’s likely going to be dry at sunrise, but it won’t be too long before some of the moisture begins to reach the Hudson Valley…

You can see on the simulation, that the bulk of the moisture will be off to our west, in western PA.  But some patchy areas of moisture could race out ahead of the main area of precipitation.  That could spell patchy areas of light rain showers, mixing with light sleet showers… across the Hudson Valley during the morning on Thursday.

But as we just showed you, temperatures will be above freezing at this point.  In addition, coming off a record warm day, the ground is going to be very warm, unable to support snow or ice accumulating to either grass or roadways. So anything that falls during the morning… whether it’s liquid rain or sleet pellets… will melt on contact with the ground.  Still, plan for areas of wet roads for the end of the AM commute, and the later half of the morning.

As the morning continues, and the afternoon approaches… we’ll see the temperatures fall near freezing.  Check out the projected temperatures as of 1pm…

So now, once we move into the afternoon… temperatures are now cold enough to support wintry precipitation falling to the ground.  And as a result, it’s the afternoon where problems could arise across the Hudson Valley.

This simulation for 4pm Thursday afternoon is still fairly accurate.  We expect a widespread area of steady sleet to fall across the majority of the Hudson Valley.  As you move into the Catskills and the northern Hudson Valley, the sleet could transition over to snow.  With the colder temperatures at the surface… it’s likely that we’ll begin to see the sleet and snow accumulate to the ground… both the paved and unpaved surfaces.  So with a prolonged period of steady sleet possible for the afternoon… an icy PM commute is possible anywhere north of I-287.

The precipitation area is small, and rather fast moving.  So just as quickly as it begins, it will taper off.  The sleet and snow will exit from west to east, between 4pm and 7pm across the region.

We’re still working on the exact details… and will be busy through the night.  We’ll likely have a live stream on Facebook, and numerous updates as we gather more information.  A Final Storm Forecast is possible late tonight, after midnight… or by sunrise on Thursday.