Monday Discussion : Quiet Start to the Week

On Sunday, we saw an upper level low pressure bring valley rain showers and mountain wet snows to the region. As we move into the start of the work week things will dry out with a NW flow in the wake of the upper level trough. So we’ll see sunshine mixing with clouds, breezy conditions, and temperatures near average in the low 50s for afternoon highs.
Similar conditions are likely on Tuesday, as we have sunshine to start the day, with increasing afternoon clouds, and a chance of rain by sunset. Rain showers are expected Tuesday night into Wednesday around the region.
 
But at least for the start of the week, the weather will be quiet. Have a great Monday!

Friday Discussion : Blustery and Still Unsettled

Mostly cloudy day today with scattered showers, winds will increase throughout the day and as the trough responsible for yesterdays weather rotates through the region a few pieces of energy rounding the bottom will cause showers to become a bit more numerous. It’s passage will be marked by dropping temps, partially clearing skies and winds shifting and increasing out of the NW.

Projected Wind Gusts Friday Afternoon:

Winds of 20-30 MPH are possible by later this evening and overnight with higher gusts across the favorable higher slopes of the Catskills.
Futurecast Radar : Friday Afternoon
Colder air rushing in from the NW and some moisture off the Great Lakes will lead to some periods of snow at higher elevations with 1-2” possible above 2000’ especially across the western and central Catskills.
High pressure building back into the region will lead to a better day tomorrow albeit still breezy and cooler, our nearest star will make an appearance.

Wednesday Discussion : Feeling More Like Spring

A beautiful Wednesday shaping up, with mostly sunny skies and a SW flow helping to lift temperatures up into the low and mid 60s around the Hudson Valley this afternoon. A wonderful day to get outside and enjoy a preview of spring time weather!
 
A weak coastal system will creep up the coast overnight, and bring clouds back into the region, and even some scattered rain showers around mid day on Thursday. Amounts appear very light, but could dampen your Thursday plans, as well as bring much cooler temps due to the low clouds.
 
Friday looks beautiful, followed by another storm system for Saturday that could bring a period of steady rain, and the storm could linger into Sunday… but the details are still quite unclear. So, Sunday could turn out nicer than it appears on the current 5 Day… stay tuned.
 
We hope everyone has a great Wednesday!

2021-2022 HVW Winter Outlook

The leaves on the trees are rapidly covering the ground across the Hudson Valley.  The air is beginning to feel a bit more crisp in the morning, and the children just celebrated Halloween.  As our minds begin to turn toward more wintry thoughts, it must mean that it’s time for the HVW Winter Outlook once again.  Each fall season, we compile observational weather data from across the globe, and begin to compare it against historical weather conditions.  We use a series of metrics and data elements to project our best bet for the coming winter.  Based on that data, and the long range computer guidance… lets take a look at what this coming winter may hold for the Hudson Valley.

Winter Temperatures : Near to Slightly Below Average (-1.5° to +0.5° vs. Average)

Winter temperatures in the Hudson Valley are likely to be near to slightly below average.  For the second straight season, a weak to moderate La Nina is projected.  This combined with similarly warm waters in the northern Pacific, should lead to persistant ridging over the northeast Pacific Ocean.  This should result in a persistent trough in the eastern US, and that should allow frequent shots of cold air to infiltrate the Northeast US.  The core of the cold is likely to be in the upper midwest, but even our area could be slightly below average for the season as a whole.  The other point worth mention, is that we could see a faster start to winter than in previous years.  A colder than average December is appearing increasingly likely.

Winter Snowfall : Near to Above Average (100% – 125% of Average) 43″ to 54″

A winter projecting a peristent trough in the eastern US is also favorable for a snowier than average winter season.  The regular access to cold air, combined with a trend that favors storms to track along and up the east coast, sets the stage for multiple east coast snowstorms.  Major snow events are a bit random due to the combination of ingredients that are needed, and thus are difficult to reliably project in a winter outlook.  However, based on seasons that had very similar conditions, this coming winter appears likely to have several opportunities for significant snow events, that could result in slightly above average snowfall.  The seasonal average in Poughkeepsie over the last 30 years is 43.0″.  We project between 43″ and 54″ of snow this season.  For perspective, Poughkeepsie saw 50.4″ of snow last winter.

Month by Month

For a little more detail, here is each month’s temperature and snowfall projection, for a more detailed idea of how the winter may play out, month by month.

December

January

February

March

Methodology / Discussion

By now, many of you may have a fairly good idea of the factors and indicators we usually look at when compiling the data for the Winter Outlook.  Everything starts with the Sea Surface Temperatures or SSTs.

When we look at the SST pattern, we are looking for years that have a similar SST profile to the current and projected pattern for the winter.  You can see the current sea surface temperatures and how they compare to average.  We like to focus in on 3 specific areas when creating the winter outlook.  The area labeled ‘A’ is the tropical Pacific Ocean or the ENSO (El Nino Southern Oscillation).  This is where the terms “El Nino” and “La Nina” come from.  The slightly cooler than average temperatures hint at a possible weak ‘La Nina’ for the coming winter.  The area labeled ‘B’ is the northern Pacific Ocean, and that is key because of the amount of warm water in that part of the ocean over the past several years.  The warm water favors an atmospheric ridge over the western US, which also then favors a reflexive eastern trough.  Then lastly area ‘C’ is the northwest Atlantic, which is important for the same reason ‘B’ is.  The warm waters tend to favor ridging over the Atlantic, which could have influence on the winter storm track, as well as the potential for warm air to sneak up the east coast.

So we can see the current pattern in place, next we want to see if we expect any dramatic changes in the pattern for the coming winter.

The seasonal computer guidance suggests the ENSO region ‘A’, may cool a bit more, signaling a weak to moderate La Nina for the coming winter.  The northern Pacific ‘B’ warm pool is projected to hold, with some cooler than average waters developing along the North American coastline.  The Atlantic Ocean ‘C’ continues to be warmer than average.  As a whole, the computer data does not change too dramatically from the current conditions… the biggest factor being the additional cooling of the ENSO region.

So now that we have good agreement between the current SSTs and the computer model SSTs, the next step is the most labor intensive.  We go through over 50 years of data, and look for winters that most similarly reflect the conditions shown above.  We select the years that are the best fit, and those become our analog years, from which we will develop the winter outlook.  After researching the data, we have pulled 7 winters.  When we blend those 7 winter SSTs, it looks very similar to the computer model projection for the winter.

Those winters are: 1995-1996, 2000-2001, 2005-2006, 2008-2009, 2013-2014, 2017-2018 and 2020-2021.  When blending those 7 winters, the analog SST pattern looks impressively closer to the projected winter pattern by the model.  The logic being, if the conditions this winter are the same as these years in the past, then we should experience similar results.  So this season, in addition to the SST pattern, we brought in a few new tools.  Three additional factors we analyzed for similarities were:  Atlantic Tropical Seasons prior to the winter; QBO (Quasi-Biennial Oscillation) index; and warmer than average Octobers prior to the winter.

In the interest of time, we won’t detail all of them here, but we will go into more detail in later discussions.  For purposes of this conversation, what is important to understand is that for each of these criteria, we went through roughly the last 30 winter seasons, and reviewed each criteria for years that were similar to the conditions we are experiencing, or expecting this winter.  We selected those years, and compared them to the winters we identified through the SST method above.  Several winters appeared multiple times in the additional criteria, especially the 1995-1996, 2005-2006, and 2017-2018 winters.  The reason this is important, is because we were able to develop multiple layers of assurance that our analog years are accurate.

Conclusion

Seasonal forecasting is a very imperfect science.  It relies on a set of assumptions, that are built on a forecast.  More simply, a forecast based on a forecast.  We know what our current conditions are, because we can observe them.  But we cannot be sure that those conditions will be the same several months from now.  So we rely on a computer model forecast data to extrapolate if those conditions will be the same 2 or 3 months from now.  Then… based off that data, we then use our experience and understanding of the science to develop the winter outlook based on a variety of additional factors.  With that said… last season, we actually did OK…

The actual temperatures were about a half a degree out of the range we projected.  That could be attributed in part to climate change, because global temperatures 20 or 30 years ago were a degree or so cooler, which we try (but may not fully) take into consideration when developing the outlook.  But our snowfall projection of 100% to 133% of average (42″ to 56″) likely seems like a large range… but when you recognize that in 19-20 Poughkeepsie saw only 16″ of snow… it doesn’t seem like that large of a range.  We saw 50.4″ (120% of the annual average) of snow… when the annual average in Poughkeepsie was 42″ at the start of last season.

So there is certainly ability to project correctly in these winter outlooks, it just relies on there being no surprises in the projected data.  Will we see surprises this winter?  Almost certainly.  The big question will be, what kind of surprises?  Luckily for you… we’ll be here to enjoy the ride with you, and discover what the coming winter holds.  We hope you enjoyed the 2021-2022 Winter Outlook.  Thank you all for your continued support.

-Alex and Bill

Saturday Mid Day Discussion : Grey and Damp

A cloudy, damp, and at times drizzly afternoon on tap for the Hudson Valley.

The steadier rain showers have shifted east of our area at this time, and should remain there for the afternoon. Here in the valley, we will see clouds and periods of drizzle this afternoon. A few breaks of sun are also possible, so don’t be surprised if we see a few peeks of sun. Temps currently in the low to mid 50s… should top out in the upper 50s to low 60s in a few spots.

A period of rain showers are possible again tonight, as a second wave of energy moves up the east coast tonight. The best chance for steady rain would be from the Hudson River and points east. Timing would be from 6pm to midnight. So be sure to plan for that if you have plans this evening. We’ll try to share info as the batch of rain approaches, but it does look like a damp evening for many of us.

Conditions should improve a little for our Sunday, with mostly cloudy skies and a passing spot shower. Highs for Halloween look to be near 60°. And most importantly… the late afternoon and evening look DRY! Have a nice afternoon, Hudson Valley!

Wednesday Discussion : Following Fred’s Fragments

Remnants of Fred to impact the region with tropical downpours. The remains of Fred will track to the NW of the region, guidance continues to focus the heaviest rainfall just to our north and west. Flood watches are in effect for Sullivan and Delaware counties for this reason.
Heavy rainfall amounts of 1-2” are possible with the highest probability being across the NW parts of the region. Locally heavier amounts are likely across the higher terrain as rainfall will be enhancement by local topography.
Also can’t rule out localized areas of flash flooding outside of the flash flood watch counties. This will likely occur under slow moving storms the redevelop over the same area. We will monitor radar for this potential.
We will need to closely monitor the eastern side of the circulation of Fred’s remnants, a squall line may develop and this line may contain severe weather and even the threat of isolated tornadoes. Our region will be on the eastern side of the circulation so stay weather aware.

Sunday Afternoon Discussion : Evening T-Storms Possible

Summary:
– Low clouds and spotty showers expected through sunset
– Temps in the low to mid 70s
– Tracking potential line of T-Storms 7pm to 11pm
– Best chance for Severe storms in Catskills (wind gusts)
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Another cool summer afternoon around the region. Clouds have increased across the region, and that has helped keep temperatures in the low to mid 70s as of 4pm, which is around 10° below average for this time of year. Some patchy areas of drizzle are showing up on radar, moving NE through the lower Hudson Valley. These spot showers and drizzle will be with us for the rest of the afternoon.
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Then our attention shifts to the batch of rain and downpours to our northwest. A cold front will begin moving toward the Hudson Valley this evening, and bringing an area or rain showers with it. Guidance suggests a squall line of showers and thunderstorms will intensify over central NY and begin moving SE in our direction. At this time, there are no strong or severe storms associated with this line of showers and thunderstorms, as you can see on the radar image. The seasonably cool temps and low clouds will help stabilize the air mass, so we will have to see if the computer guidance has the right idea, or if the data is a bit too aggressive. Nonetheless, in response to the squall line the data is seeing, the National Weather Service has increased their thunderstorm outlook to include a small area of “Slight Risk” for the Catskills… and the rest of the region in a “Marginal Risk”. The squall line reaches the Hudson Valley between 6pm and 10pm, mainly after sunset… so the showers and storms should be weakening as they arrive in our area. For that reason, we are NOT issuing a Stormpact map for today. But we’ll keep an eye on the situation this evening just the same.
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Futurecast Radar : 4pm to 11pm Sunday

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We hope everyone is having a wonderful Sunday afternoon! Updates will follow this evening as needed.

Tuesday Discussion : Final Snowfall Forecast 1/26

A weak storm system will push into the Hudson Valley on Tuesday and spread widespread accumulating snow into the region for the first time in weeks.  While not a major event, it could still cause some travel headaches and hazardous conditions across our area.

Timing (Tuesday):
– 10am to 1pm : Snow begins from SW to NE
– 12pm to 4pm : Period of moderate snow expected
– 4pm to 6am Wednesday : On and off periods of light snow
– 6am to 10am Wednesday : Snow showers taper off

Impact / Conditions:
– Steadiest snow likely at the onset, could fall up to 1″ per hour for a time
– By late afternoon Tuesday, lighter snow expected, could last into night
– Snow could mix with sleet south of I-84 late in afternoon
– Temps in 20s, snow accumulates to all surfaces, icy roads possible
– Tuesday PM and Wednesday AM commutes could be hazardous

Snow Accumulation:
– Catskills (Zone 1 & 2) : 4 to 8 inches
– Mid & Upper HV (Zone 3,4,5,6,7,8) : 2 to 6 inches
– Low Hudson Valley (Zone 9) : 1 to 3 inches

— Forecast Discussion —

A weakening storm pushing into the northeast will create a bit of a mess for the Hudson Valley on Tuesday.  Snow is likely to spread into the Hudson Valley between 10am and 1pm in most areas, and it could come down quite hard for a couple of hours…

Futurecast Radar : 10am to 4pm

The weakening system approaches disorganized, and then at the last minute, the atmospheric vorticity intensifies over NE PA, and snow should rapidly develop and become quite heavy for a brief time.  To get a visualization of what causes this moderate to heavy snow band to develop right over top of us, here is the 700mb vorticity loop for roughly the same time as the radar shown above.

700mb Vorticity 7am to 7pm

Vorticity is a measure of the rotation and lift of the air at this layer of the atmosphere.  The red and purple band develops over PA and moves NE, and that sudden rotation and lift of the air, should generate the moderate to potentially briefly heavy snow for Tuesday afternoon around the region.  For that reason, we’re concerned about a 1 to 2 hour burst of moderate to heavy snow across the region, close to the onset of the snow.  This could cause a quick 1″ of snow in spots, and create some very hazardous travel if people are caught off guard.

As the afternoon progresses, the back edge of the main area of moisture approaches between 4pm and 8pm.  As it does, some of the guidance wants to mix parts of the region with sleet and possibly even freezing rain.  We won’t discount it… but we have looked at projected soundings, and cannot see how this actually occurs.  All layers of the atmosphere are projected to be safely (3 to 6 degrees C) below freezing.  Either the sounding data is wrong… or the map above is wrong… because the soundings point to an all snow event.  We’ll see how it unfolds.  A wintry mix would reduce snow totals… so we’ll watch closely Tuesday afternoon.

By 6pm, the models show a widespread 2 to 4 inches of snow falling around the Hudson Valley.  If the front edge of the snow is as potent as latest data is suggesting, it is entirely possible that we have 2 to 4 inches on the ground by sunset.  The Tuesday PM commute is likely to be quite treacherous, so make sure to take it slow.

From there… the remainder of the event is a bit uncertain.  Some guidance keeps light snow showers in the region through the night Tuesday night, which could add an extra inch or so to the snow totals by Wednesday morning.  In addition, it would make for a potentially icy start to our Wednesday as well.  We’ll have more on that later on Tuesday, so check for updates.

An interesting, disorganized, and rather uncertain event on the way for Tuesday.  We’ll see what Mother Nature has in store for us.  Stay warm, stay safe… have a great day!

Monday Discussion : Clouds but Tranquil

Happy Martin Luther King Jr. Day, Hudson Valley!

We’ve got a mostly cloudy start to our week, with WNW winds pulling clouds and lake effect snow showers into the Catskills.  The snow showers and flurries are drying out for the most part before reaching the valley, but the clouds are with us.  Afternoon highs into the upper 30s and low 40s are expected.  Tonight, clouds give way to partly cloudy skies, and overnight lows in the low to mid 20s.

For the much of the week, we’ll see similar conditions.  Clouds mixing with sunshine, and periods of scattered flurries and snow showers… especially on Wednesday.  Highs through the week are likely to be in the mid 30s, and possibly some low 30s on Wednesday and Thursday.  Things are likely to stay tranquil and quiet through the weekend, as the jet stream has flattened out a bit, and is not allowing any storms to develop.

We hope everyone has a great Monday!