November 7, 2023 Afternoon Update
West coast storms early next week to bury California Sierra in snow
The Lower 48 remains rather quiet in terms of winter weather with some minor storms and somewhat cooler air heading into the weekend. Then, it warms dramatically across the eastern 2/3 of the U.S. with much above average temperatures.
The most extreme weather will be along the California coast as the storm track is aligned out of the north from the Gulf of Alaska. There is plenty of cold air to turn the Pacific origin atmospheric rivers ahead of cyclones into very heavy mountain snow. We’ll be talking 5-feet or more in the California Sierra. However, at lower elevations, there is a risk of significant rainfall and coastal impacts. This isn’t a typical El Niño storm track at all, but for the beginning of the water year, it’s impressive.
Above Normal Temperatures overall for the next 2-weeks across much of North America. Where cooler air can break into the Lower 48, including New England and the Western U.S. over the next 7-10 days, we’ll see wintry precipitation. Otherwise, it’s going to be mild and not feeling like winter at all.
Week 1: November 7-14 [EPS Control 12z]
Week 2: November 14-21 [EPS Control 12z]
Snowfall over next 15-days
Days 1-5
From the ECMWF Control Run (same model configuration as HRES but out to 15-days), unsettled weather across the Canadian border could drop a few inches of snowfall, mainly light including Michigan and New England — probably flurries, but mostly light rain. Nothing to plow yet.
Huge accumulations in coastal British Columbia and Quebec.
Days 6-10 Snowfall and total Precipitation [ECMWF EPS Control 12z weathermodels.com]
This California snowfall event could be on the order of 7-feet or more. This is enormous. At lower elevations, 2-4” of rainfall. This is from Sunday to Friday next week. Hugely beneficial for California’s always critical water management. Of course, in a typical El Niño winter, we need to worry about storms coming out of the SW with the pineapple express.
Days 11-15 Snowfall
The main focus of snowfall will be over the Western 1/3 of the U.S. especially in Rockies from Nov 17-22 as that’s where the cold air will be. Mild weather and well above average temperatures will keep the rest of the Lower 48 warm.
Of course, this is not an ensemble, but just 1 particular deterministic forecast.
So, the best way to examine the overall risk for snowfall during the next 15-days is to look at the probability of seeing at least 1-inch of snowfall from all 51-members of the EPS ensemble. Scant chances over Chicago, Detroit, D.C., NYC or Boston for the next 2-weeks.
Pacific Northwest Rainfall and South Texas / Gulf of Mexico flow
WPC has put a 10-inch bullseye over the Gulf of Mexico off SE Texas with 2-3” amounts just inland during the next 7-days. That’s very impressive as deep tropical moisture arrives out of the Caribbean in a series of surges. Texas always needs rain, but Louisiana could really benefit from that blob.
Wednesday High Temperatures
Over 165 million at/above 70°F on November 8th!
And 77 million at/above 80°F. Even 1.25 million at/above 90°F in Texas.
The warmth extends into Chicago, but just misses Detroit. No such luck for 60s-70s in NYC or New England.
2023 Atlantic Hurricane Season | Medium Range Outlook
NHC does not have any areas of interest in the next 7-days.
While GFS continues spinning up powerful hurricanes out of the very southwest Caribbean, the other models are less enthusiastic. However, the EPS ensembles do show some members ~1/4 of them developing a tropical system.
This is the climatologically favored area for development in November, so the SW Caribbean always bears watching.
2023 Eastern Pacific Hurricane Season
No activity expected for at least the next 7-days.
2023 Western Pacific Typhoon Season
Watching the area east of the Philippines for development over the next 5-days. The 10-day EPS tracks show whatever develops moving westward, and could become very intense prior to impacting the islands.
2023 North Indian Ocean Cyclone Season
Quiet for the next 5-days
2023-24 South Pacific Cyclone Season
Quiet for next 5-days.
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