How much snow will we get this time??
It appears that the Holland Patent area will see its first Nor'easter of the season this weekend. Before you get too excited, I must state that the term "nor'easter" does not always refer to a snow storm, and this weekend we can expect nothing but rain. The term "nor'easter" simply refers to any storm that travels up the East Coast that pulls a significant source of its energy from a large temperature difference between the northern and southern sides of the storm. This setup means that we along the coast experience winds out of the northeast, while the areas above the waters of the Atlantic experience a wind out of the southwest. Generally during the summer, this temperature difference is not sufficient for the formation of nor'easters, hence the vast majority form in the winter, when temperatures support snow. Although they will be oh-so-close this weekend (mid to upper 30s), we won't quite be in snow range.
What can we expect?
Rain. A lot of it, for a long time. The bulk of the precipitation will fall on Saturday, with most of the region looking at 1" to 1.5" of rain that day. The gloom continues on Sunday and Monday as on-and-off lake effect rain showers will add another 0.25" to 0.5" to our total. A light breeze will remain with us through Tuesday, although nothing damaging is expected. The image below shows the total rainfall forecast expected for our area, with 1.52" expected for Holland Patent.
Will anyone see the flakes falling?
While temperatures are too warm for the Holland Patent area, that will not be the case for the upper elevations of the Adirondacks. As of now, the high peaks could pick up anywhere from 4"-12" of snow. Most accumulation, however, should be confined to regions above 3000 feet. This precludes Snow Ridge, Oak Mountain, and McCauley Mountain from seeing any snowfall, however the summit regions of Gore Mountain and Whiteface Mountain could cash in on some pre-season snowfall. A reminder that Whiteface has set their opening date for November 23rd (the day after Thanksgiving)! The image below shows the total snowfall forecast for this nor'easter. The 6" represents the forecast for Whiteface Mountain. Nothing for our area.
After weeks of above average temperatures, we may finally be in store for an extended period of below average conditions. The core of this cold air looks to arrive Wednesday night (10/17). Temperatures will be below freezing for the entire area early Thursday morning, with a very high likelihood of a frost. Although growing season is officially over for the Holland Patent area, if you have sensitive vegetation outdoors, cover it or move it inside by Wednesday evening.
What's bringing the cold?
The cold air mass that will move into the area for Wednesday can be attributed to a strong high pressure system located over Illinois. Because high pressure systems spin in a clockwise rotation, it's location places us on the "cold side", with the prevailing wind over Central New York locked in a northwesterly flow, blowing cold air from Canada our way. The images below shows Wednesday's temperature setup.
How low will we go?
As I mentioned above, we can expect a frost. The overnight lows for Wednesday look to be between 25ºF and 28ºF, depending on how quickly the clouds move out from Wednesday's lake effect rain. The maps below are the major model's predictions for the lows. Given that we are still a couple days away from the cold, the models are in relatively good agreement with each other.
Will we see snow?
While temperatures will certainly be cold enough to support snow, the air mass will be drying out as Wednesday night progresses, so while we may see a brief flurry before or around midnight, skies should be clearing out as we head into early Thursday morning. Whatever falls will not accumulate, and there's virtually zero chance that these flurries will lead to a delay on Thursday morning. The next chance of snow looks to be the beginning of next week, although much like this event, the snow will not amount to much, and it should not impact travel.
While we're all familiar with lake effect snow (if not, click here), lake effect rain is a far less common occurrence. The same phenomenon applies, cold air blows over the relatively warmer waters of Lake Ontario, picking up moisture and depositing it upon us. This time, the air is not quite cold enough to support snowfall, so precipitation falls as rain. Just like lake effect snow, the rain falls in finger-like bands. The example below is from this morning. As we can see, a narrow but intense band of rain is situated just south of Watertown.
The rapidly changing wind direction today will lead to periods of rain and low clouds, followed by breaks of sun. As the wind changes to a southerly direction tomorrow, we will see a return to pleasant and sunny conditions. However, as another cold front swings through on Monday, switching the wind to a northwesterly flow, the lake effect rain will return, and we will see the frequently changing conditions throughout the day.
Why don't we see this more often?
As discussed in the lake effect page, lake effect snow and/or rain is fueled by a difference in temperature between the lake water and the air mass above it. With today's high being in the mid 40s, and the lake temperature being about 58ºF, the temperature difference is just enough to allow for lake effect. If the air temperature were 5ºF warmer, there would not be enough of a difference to allow for lake effect. If the water were 10ºF colder, the precipitation would be falling as snow, not rain. Given the relative stability of lake temperatures, air temperatures that can support lake effect rain are generally only range from about 35ºF to 45 ºF. On the other hand, a temperature anywhere from 34ºF to -20ºF, a 54ºF range, can support lake effect snow. To summarize, there is a lot smaller margin of error for lake effect rain conditions than there is for lake effect snow conditions.
Out of Nowhere
It seemingly sprang up out of nowhere. Fueled by favorable wind conditions and above-average water temperatures, Hurricane Michael blew up from a tropical depression to a Category 4 Hurricane in the matter of three days. While it appears at this point that Michael will make landfall as a Category 4 Hurricane, that did not seem to be the case three days ago. Weather models, especially the GFS-the favored model of the National Hurricane Center-predicted a substantially greater wind shear than what ended up happening. Wind shear refers to wind blowing in different speeds and directions at different altitudes within the atmosphere. Having strong wind shear essentially rips a hurricane apart by pushing and pulling at it from all different directions. Without the strong wind shear yesterday and today, Michael was able to rapidly develop. The illustration below shows what hurricanes will do when there is and when there is not strong wind shear. Unfortunately for the folks of Florida, Michael is taking the scenario demonstrated by the right side of the picture.
Although landfall is inevitable at this point, there are still slight differences in the track that will have a major impact in terms of the devastation. This is because of questions whether or not the bullseye of the Hurricane will track through Panama City, a significant population center on the Florida Panhandle, or just to the east, impacting a far less populated area of the state. As of now, the model trend seems to be pushing Michael just to the east of Panama City. We shall see if this comes to fruition.
Will Central New York be Impacted?
No. Thankfully, a cold front that will move through the area later today will help to steer the eventual remains from Hurricane Michael well east of our area, with the storm forecasted to move out to sea after it exits the continental U.S. along the Carolina Coast.
Summer has made a brief return to the area, and will be with us through Wednesday. Highs are forecasted to crack the 80 degree mark on both Tuesday and Wednesday. The humidity will also be a factor, making the temperature feel 3 to 5 degrees warmer than they actually are. Accompanying this warmup will be a period of generally sunny skies, as high pressure moves over the area.
Enjoy it while it lasts.
The aforementioned high pressure system scoots out of the area Wednesday night, giving way to a strong cold front that will drop daytime highs by over 30ºF. As this cold front continues to move east, it will stall out as it winds from Hurricane Michael will push against the cold front's forward momentum. The obvious good news is the presence of this stalled front will keep the remains of the hurricane far away from Central New York. The bad news is the stalled front will keep clouds and gloomy weather over the area for an extended period of time. It's not likely that we'll catch a glimpse of sun until late Sunday, no pun intended.
It's finally here! After weeks of looking over global computer models, and climate records from previous years with similar conditions going into the winter season, I am ready to release my outlook for this upcoming winter.
For starters, let's establish a ground rule. Given that this outlook covers such a broad timespan, This forecast is largely based on global weather patterns, and microscale events that shape our day-to-day weather simply cannot be taken into consideration this far away. Therefore, this outlook does not forecast specific snow storms, cold snaps, etc., but rather, what we can expect this winter to be like as a whole. With that being said, let's get started!
December & January: 3°F to 5°F above average
February & March: 2°F below average to 1°F above average
The first thing to consider when making a winter temperature outlook is the El Nino-Southern Oscillation (ENSO) cycle. This is essentially just a fancy way of referring to the ocean temperature of the Pacific Ocean between the West Coast of South America and Australia. The ENSO cycle has two phases: El Nino and La Nina. During an El Nino phase, water temperatures are above average, while they are below average during a La Nina cycle.
Now, why exactly are we concerned with ocean temperatures in the eastern Pacific Ocean? Because it is these temperatures that determine the overall trajectory of the jet stream, which functions as the highway that major storms travel along, as well as the dividing line between cold air (to the north of the jet stream) and mild air (to the south of the jet stream). This season, we are looking at a moderate El Nino pattern.
As we can see from the graph above (courtesy of NOAA), an El Nino pattern keeps the frigid temperatures associated with the Polar Jet Stream to the north of Central New York. That's not to say we won't have any cold snaps, we will, but in general, expect a warmer winter than average, especially during the first half of the season. As winter progresses, however, we can expect the temperatures to become slightly colder. This prediction is attributed to long-range models suggesting the North Atlantic Oscillation (NAO) transitioning from a positive phase to a negative phase as the season goes on. The NAO is separate from El Nino and La Nina, as the NAO takes place in the Atlantic (hence the name), and has to do with atmospheric pressure, rather than ocean temperatures. Similar to El Nino and La Nina, NAO effects the direction of the jet stream. A negative phase causes the jet stream to wrap around the East Coast of the US, allowing Arctic air to infiltrate Central New York. On the other hand, a positive NAO keeps the cold air to our north.
With all of that being said, I'll conclude the temperature section by stating that specific spans of mild and cold periods throughout the winter are determined by the interaction of the ENSO and NAO cycles. These factors are too complex and specific for weather models to pick up on this far away, but by looking at the general cycle patterns of each, we can have a broad idea as to what the temperatures will be like during this winter.
December & January: 33" (average: 40")
February & March: 52" (average: 57")
Forecasting snowfall for Central New York is notoriously tougher than temperature predictions. This is because while cold air masses and air masses effect entire regions of the country, snowfall is a much more localized phenomenon, especially here in Central New York. This is primarily due to lake effect snow, which can dump huge amounts of snow over a very small area. For more information on lake effect snow, click here. With that being said, lake effect snow is the primary component of the snowfall forecast. As of October 3rd, NOAA reports that the surface temperature of Lake Ontario (the source of our lake effect) is running over 6°F above average. That is significantly above average, and will continue to remain above average for at least the next several months.
Although a warmer lake temperature allows for more powerful lake effect snow events, I still predict that we won't see above average snowfall because of the prevailing wind direction, brought by El Nino and a positive NAO (at least during the beginning of winter-the most active time for lake effect), will keep the bulk of most lake effect snow events just north of the Holland Patent school district. Areas such as the Tug Hill Plateau and western Adirondacks will face the brunt of this lake effect, and therefore they will likely see average to above average snowfall during December and January.
Synoptic snow refers to snow that comes from literally any other type of snow storm besides lake effect. It goes without saying that synoptic snow is the other component of my snowfall forecast. Given the direction of the jet stream, as determined by the ENSO and NAO cycles, I predict that some synoptic storms that impact our area will track to our west, Whenever winter storms track to the west of Central New York, they bring milder air, and we get a cold rain event instead of snow. To learn more about how the track of a storm determines if we get rain or snow, click here. It is because of this that I predict we will see slightly below average snowfall during the second half of winter, even with colder temperatures predicted.
I hope you have enjoyed reading the 2018-19 Winter Outlook. If you have any thoughts or questions, comment below!