Friday, November 21, 2025

11/21/2025

An already light event gets lighter

The clipper on the way continues to lose juice. A southwesterly wind may not provide enough moisture to enhance it. It will be the breeze out ahead of the cold front, and after its passage, that will be more noticeable than the precipitation. Wind gusts 10-20 mph build during the day, and increase out of the northwest on the backside to 20-30 mph on Saturday, before subsiding Saturday night.

Opening day on the some of the ski hills will be a cool one with windchills in the teens and 20s on the summits. As the surface high moves in on Saturday, areas not shaded by the Whites will feel that chill, too.

Another weak clipper may bring snow showers to the mountains Sunday night into Monday. The next feature to watch is Wednesday, which bring a chance for rain showers. The frontal boundary that works through then may stall offshore. An ocean storm may fire along it and bring showers to the coast for the holiday, with breezy conditions statewide. Forecast confidence how that all plays out is low at this point, but I do not foresee any concerns for snow to impact travel on the front side of the weekend.

About the drought

The latest Drought Monitor update shows improvement from the previous week, but the look is deceiving. With the recent rainfall, river flows have edged upward, taking the edge off. Given the colder temperatures and shorter days, evapotranspiration levels are reduced, which means precipitation that falls stays on the surface longer and is less easily absorbed by sunlight.

The groundwater supply issue remains the primary concern and will continue into the winter. The ground is close to, if not frozen over, much of the interior, and it is getting there along the coastal plain. Walking around my neighborhood trails in Kennebunk has been like a never-ending sidewalk, with a hardpan surface prevalent. Time has more or less run out for water to get into the ground, unless we get a parade of soakers, and that appears unlikely.

Looking at the drought forecast through February, it does show potential for improvement, but that is subjective because after the ground freezes, groundwater resources are stuck in neutral until the spring thaw.

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About long term model ideas

Social media is a cesspool of bad weather information from forecaster wannabes and degreed meteorologists, both boosting their egos with shares and followers, and making money doing it. Every winter or hurricane season, doomsday tropical systems and epic snowstorms get spread around like butter on hot toast. I do not operate this way. I figured out that integrity is a great way to make friends in the business and build respect, rather than acting like an imbecile and creating enemies, even though I still have those who want to see me fail. I will never get rich doing this since I don't play the game, and I will take integrity to the pearly gates when my time is up.

I am using this image because it is the easiest for me to explain without resorting to multiple images. The idea is to use atmospheric heights at the 500mb steering level (it's like surface highs and lows), roughly 20,000 feet up, and 850mb temperature, at approximately 5,000 feet. The atmosphere works from the top down.

What I watch in the times that snow or junk may fall is what each of those two levels is doing. Looking at the 500mb chart, the "540 line" is known as the "rain/snow line". While that is not exact, it does indicate that snow or junk is a possibility. With heights that low, it's a telltale sign that cold air is around, and looking at the 850mb temps shows it is there. Of course, you cannot see the potential of variables near the surface (surface temperature, warm noses, wind direction, moisture content in the air, etc.), which is why when the 540 line is around, precipitation type is not a lock. We've had messy storms in the 540+ range before, and we've had rainy sub-540 events, too.

Looking at the backside of the Thanksgiving weekend, the ensemble mean indicates that cold air is likely to persist at 850mb, which makes sense given that a cold front is expected to move through the region heading into the holiday. The difference between the control (which shows storm potential) and the ensemble mean is substantial. It's difficult for a forecaster with any credibility to take the control idea seriously in this case.

I mentioned in Thursday's post that I don't take long-term ideas seriously when an upper low is over the Four Corners region in the southwest. This is from years of watching, a trip to Arizona to see the climate, and how models react. With the desert and the mountains close together, it screws up models, and there is no known fix for the physics. Will artificial intelligence do that? One can hope, but when you put bad information into an AI, it becomes bad, too. I am not holding my breath that it will be in the next few years, but I may be wrong.

Note how the control goes further extreme than the ensemble spread. That is another red flag that something isn't quite right with that idea. While I will not dismiss the possibility of something brewing worth staying updated on, the idea of a big dumper is rather extreme.

Long-range forecasting with operational/deterministic models is like watching a science fiction movie starring Lou Glutz from National Lampoon's Vacation. Anything beyond 7 days out is subject to scrutiny of this magnitude, whether in summer or winter.

Seeing the pattern and the ensembles riding on the idea of a more zonal pattern heading into the backside of the holiday weekend, this idea makes more sense.

Stay tuned.

My next update here comes Sunday morning.

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