All Activity

0.54" overnight/early this morning here.

My primary concern with respect to the first third of the winter season is that I rushed the recovery of the PV due to a dearth of appreciation for just how protracted the relaxation of the zonal winds would be. I went with something falling short of a full reversal, but even if we do see a reversal, I think that is largely immaterial to how the forecast will evolve. Another factor that played into my hasty recovery of the PV is that I operated on the assumption of a reflection event in mid January, which occurs during a stronger PV and entails a hasty recovery from the early season disruption. My guess is that my timing may be off, but I'll have the right idea in the seasonal mean. Reflection event may just be more towards the back end of my range, in latter January or early February. I also wish I had paid more attention to the behavior of the MJO in my primary analog of December 2000, which hit phase 8 mid month. I focuses so much on using it as an analog for the disruption of the PV that I totally brain-cramped on the behavior of the MJO. *********************************************************************** Balance of November-December 2025 Outlook December Analogs: 2021, 2017,2008, 2007, 2000, 1981, 1970 Here is how the analog composite fared versus reality for the month of October: And versus current seasonal guidance for November (CFS): The MJO is currently crossing from phase 5 into phase 6, which is triggering the abrupt transition to a much blockier and colder weather pattern that is currently underway. The progress of the wave is then forecast to stagnate as it approaches phase 7 and essentially decays around mid-month. While the cold will moderate for a time, however, the pattern will remain stormier than average, with the first snowfall likely across the higher terrain of northern New England next weekend. High latitude blocking will be consistent as the polar vortex remains weak throughout the balance of November into early December, as the arctic high regime will be prevalent. Arctic High Regime Courtesy Lee et al (2019) Here is the December composite data versus the latest CFS temperature anomaly forecast: Expect this sale style of deviation from the MC forcing during the early portion of the season. December 2017-January 2018: December 2024-January 2025: An official SSW as defined by the reversal of the mean H85mb zonal westerly winds is unlikely, however, there is a low probability of one as suggested both by the minority of guidance, and the December 4, 1981 analog. Should there be a reversal of the H85mb zonal winds, December 4th is a good estimation of the when the PV will reach its weakest point before the split, and subsequent recovery begins. As per the expectation of a significantly weakened vortex resulting from bonafide warming that will fall short of a full zonal wind reversal, the December 2000 event is the preferred analog. This is appropriate since 2000-2001 is also the top analog from the seasonal composite. Accordingly, the polar vortex should have consolidated back to at least something approaching climatological levels prior to Christmas (18th-24th). It will then continue to strengthen with moderating temperatures in the east, per research conducted Lee et al (2019), which indicates that the arctic high regime is favored for less than 20 days following a weak PV. This is also consistent with the onset of a reflection event on December 21,1981, just over two weeks after the December 4th SSW. There is a slight chance of Ku event between the first and 15th of the month. The PNA should average negative during what will be active month, with numerous SWFE and overrunning events commencing by approximately the 10th. The probability for a White Christmas is above climatological levels given the active pattern and at least seasonable cold throughout the first half of the month, but it remains dubious for the coastal plane given the milder turn prior to the holidays. In fact, the proverbial "Grinch Storm" is more likely than not. A Pacific trough should begin to evolve towards the end of the month in conjunction with a rather stout PV, as a mild pattern ensues to ring in 2026. The month of December will average anywhere near normal, anywhere to -1F to +2F, except near normal to +2F across the middle Atlantic.

Weeklies should be taken with a grain of salt but no clue why people are getting worried. Its only November .

Im not seeing any snow

Records: Highs: EWR: 73 (1963) NYC: 73 (1928) LGA: 72 (1953) JFK: 70 (1924) Lows: EWR: 19 (1936) NYC: 18 (1936) LGA: 22 (1959) JFK: 21 (1959) Historical: 1873: A severe storm raged from Georgia to Nova Scotia causing great losses to fishing fleets along the coast. In Maine, the barometric pressure reached 28.49 inches at Portland.Boston, Massachusetts recorded its lowest November pressure of 28.73 inches of mercury. (Ref. NOAA Boston Weather Events) (David Ludlum) 1891: Highest barometer reading ever recorded for November 30.85 inches at WBO at that time. (Ref. Washington Weather Records - KDCA) 1921: 54 inches of snow and sleet closed the Columbia River Highway around The Dalles, OR area. (Ref. AccWeather Weather History) 1953: The temperature at Minneapolis, MN, reached 71 degrees, their warmest reading of record for so late in the autumn. (The Weather Channel) (Ref. AccWeather Weather History) 1955: An early season cold snap finally came to an end. Helena MT experienced 138 consecutive hours of subzero temperatures, including a reading of 29 below zero, which surpassed by seven degrees their previous record for the month of November. Missoula MT broke their November record by 12 degrees with a reading of 23 below zero, and Salt Lake City, UT smashed their previous November record of zero with a reading of 14 below. Heavy snow in the Great Basin closed Donner Pass, CA, and total crop damage from the cold wave amounted to eleven million dollars. (David Ludlum) 1957: A tornado, 100 yards in width, traveled a nearly "straight as an arrow" 27-mile path from near Rosa, AL to near Albertville, AL, killing three persons. A home in the Susan Moore community in Blount County was picked up and dropped 500 feet away killing one person. (The Weather Channel) 1967: A moist subtropical storm that started on this day ended on the 21st. 14+ inches of precipitation fell in the mountains above Los Angeles, CA, 7.96 inches fell at Los Angeles. Flooding was called the “worst since 1934.” Two people were killed and 400 others were stranded in the mountains due to closed highways.: (Ref. Wilson Wx. History) 1986: The first of two successive snowstorms struck the northeastern U.S. The storm produced up to 20 inches of snow in southern New Hampshire. Two days later a second storm produced up to 30 inches of snow in northern Maine. (Ref. Storm Data) 1987: It was a windy day across parts of the nation. Gale force winds whipped the Great Lakes Region. Winds gusting to 80 mph in western New York State damaged buildings and flipped over flatbed trailers at Churchville. In Montana, high winds in the Upper Yellowstone Valley gusted to 64 mph at Livingston. Strong Santa Ana winds buffeted the mountains and valleys of southern California. (Ref. The National Weather Summary) (Storm Data) 1988: Thunderstorms developing along a warm front drenched Little Rock, AR with 7.01 inches of rain, smashing their previous record for the date of 1.91 inches. (The National Weather Summary) 1989: A second surge of arctic air brought record cold to parts of the north central U.S. Eleven cities in the Upper Midwest reported record low temperatures for the date, including Rochester MN with a reading of 4 degrees below zero. Strong winds ushering the arctic air into the north central U.S. produced squalls in the Lower Great Lakes Region. Snowfall totals in northern Ohio ranged up to twenty inches in Ashatabula County and Geauga County. (Ref. The National Weather Summary) (Storm Data) 2014: As of the midday hours on Tuesday, an unofficial snowfall measurement of 60 inches has been recorded in the past 24 hours in Lackawanna, New York, just south of Buffalo. However, snowfall of 4 feet or more has been observed in some of the south towns. Depending on the investigation of snowfall measurement activities, and if the intense snow continues through the evening Tuesday, there is a chance the 24-hour United States snowfall record may fall. That official record belongs to Silver Lake, Colorado, with 76 inches, spanning April 14-15, 1921. A report of snowfall of 77 inches in 24 hours at Montague, New York, was thrown out by officials from January 1997 because too many measurements were taken in the 24 hour period. Snowfall measurement of 60 inches just south of Buffalo, NY(Ref.Alex Sosnowski, Expert Senior Meteorologist November 18, 2014; 3:59 AM ET) Maximum Snowfall: Lake Erie 65" (S. Cheektowaga); Lake Ontario 22" (Philadelphia) Duration: 48 hours. The epic November 17-19th 2014 lake effect event will be remembered as one of the most significant winter events in Buffalo’s snowy history. Over 5 feet of snow fell over areas just east of Buffalo, with mere inches a few miles away to the north. There were 14 fatalities with this storm, hundreds of major roof collapses and structural failures, 1000s of stranded motorists, and scattered food and gas shortages due to impassable roads. (Ref.NWS, Buffalo,NY)

NYC may see first snows before most of us with this next system

Basin-wide, but east-based, nonetheless.

I do actually. However those a have lower accuracy scores.

That’s my point

GEFs are better with the PNA rising, but it’s the GEFS. I don’t understand why everyone is in a rush. We know how these go.

33 / 20 clear now. Clouds showers / snow showers later and overnight. Overall warmer than normal a few days much above normal between the 19 - 27. Trough into the Northeast towards the close of the month. Perhaps a phased change to a more sustained below normal - colder into the first week of next month.

It’s 11/18. Who cares if the cold dumps mostly out west for a week or two toward Dec? Pack usually starts settling in here 12/10-15 so it’s nbd to me until then. Anything between now and then typically melts away at some point anyway.

Happy New Year!

It may be…no arguments there. Do you feel the weeklies are a reasonable output?

Do note that it doesn’t mean interior could get something minor and have it melted a day or two later, I’m talking about more consistent stuff.

21.7

So much for a forecast low of 31! Down to 21.4 last night. The nearby PWS that isn’t in the creek valley area is ~4 degrees warmer though.

I think that is very reasonable output from that model.

We don’t look at that. Especially for you, wait until after the first week.

360 hrs…I mean how much stock can we put in that prog? 15 days out. I know, I know easier to peg long wave pattern and what not, but it’s still more than two weeks away. I know you’re just pointing it out, which is good to know. But again there are conflicting signals..which we’d expect at 15 days away.

I expect December significant snows to largely be relegated to 40N along the east coast.

Pretty deep vertically for areas with a wind reversal too.

US National Weather Service State College PA Tuesday - November 18, 2025 @ 530 AM EST: A weak ridge of high pressure over the Commonwealth will bring a brief period of clearing early today before clouds thicken up from the west later this morning through the afternoon, well ahead of low pressure located over Missouri at daybreak. This weather feature will spread a shield of chilly, steady rain across the southwestern third of Pennsylvania this afternoon and evening. As the precipitation drifts north toward the Interstate 80 corridor this evening, the air will be cold enough to allow a mixture of rain and wet snow to occur. There could be a light coating of snow on the highest ridge tops of Central PA overnight.

Thanks Walt. I’m thinking I’m a bit too far north for this little event, you concur?