2:15 PM (Thurs) | ***A wintry look across the nation with coast-to-coast cold…intense Great Lakes snow event with "thundersnow"...Rockies snow…and perhaps an eastern US storm threat late next week***
Paul Dorian
Temperatures remain at below-normal levels at mid-day across most of the country and will continue to do so through most of the upcoming weekend. Map courtesy NOAA, tropicaltidbits.com
Overview
Temperatures across most of the nation remain below-normal for this time of year and will continue to do so through the upcoming weekend. Accumulating snow is now falling in parts of the Rocky Mountain States and an intense Great Lakes snow event is just getting underway. In fact, the lake effect snow event that is just getting underway looks like it’ll be of long-duration possibly producing as much as 3-6 feet in places like Buffalo and Watertown of western New York State. Looking ahead, there are signs that after a milder first half of next week in the eastern states, the overall weather pattern could get interesting by the end of next week with an eastern US storm threat on the table…something to monitor in coming days.
One main culprit of this nationwide cold wave is extremely strong upper-level ridging over Alaska that will remain in place for a few more days. From this position, cross-polar air can flow from way up in Canada to the central and eastern US. Map courtesy NOAA, tropicaltidbits.com
Coast-to-coast cold continues
The first couple of weeks of November saw temperatures average well above normal in much of the eastern half of the nation, but the overall weather pattern changed significantly this past weekend following the departure of Tropical Storm Nicole. Virtually all the states in the Lower 48 remain at colder-than-normal levels at mid-day on Thursday and this pattern will continue for most places through the upcoming weekend. In fact, the next cold air mass that will reach US by early tomorrow could result in numerous low temperature records across the nation on Friday, Saturday and Sunday mornings with temperatures as much as 25 or 30 degrees below normal.
The “perfect” scenario for places like Buffalo and Watertown of western New York State to get pummeled by heavy snow in a Great Lakes “lake effect” event is for an extended period of time with low-level W-SW winds - and this is exactly what is on the table for these locations from later today into the upcoming weekend. Map courtesy NOAA, tropicaltidbits.com
Snowfall map with extreme amounts on the table for the Buffalo and Watertown regions in western New York State. map courtesy NOAA/Buffalo NWS
Rocky Mountain snow…an intense Great Lakes snow event with “thundersnow”
In terms of snow, accumulating snow is falling today across parts of the Rocky Mountains and places like Boulder and Denver in Colorado could end up with several inches by early Friday. Meanwhile, an intense and potentially paralyzing Great Lakes “lake effect” snow event is just getting underway. Atmospheric conditions will become just right for heavy snow bands to develop over Lakes Erie and Ontario in coming days. This will be a very unstable atmospheric event with a steep lapse rate and likely to feature “thundersnow” and hourly snow rates of 4 or 5 inches in some spots. In terms of total snowfall amounts, crippling levels are possible on the order of several feet in places like Buffalo and Watertown in western New York State. This will be a long duration event - not winding down until later in the weekend.
There are signs for a strong upper-level low to form in the eastern US late next week/weekend at the same time ridging pops up across the western states. This is a setup that will need to be monitored in coming days as it could result in a powerful east storm late next week. Map courtesy NOAA, tropicaltidbits.com
An eastern US storm threat late next week/weekend
Looking ahead (and this is still way early and in the “speculation” phase), the overall weather pattern could get quite interesting by the end of next week or weekend in the eastern US. After an easing of the cold during the first half of next week, signs point to the formation of a deep upper-level low pressure system by the end of the week or weekend in the eastern US along with a strong ridge forming over the western states. In addition, there will likely be another upper-level low situated over eastern Canada (around 50 degrees N, 50 degrees W) which is often a favorable location to increase the chance for a storm in the eastern US. This time period of late next week/weekend is something we’ll monitor closely in coming days.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com
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Video discussion that focuses in on the intense Great Lakes snow event: