The biggest change to the forecast this morning is trying to nail down how much cold air will be able to make its way into the region this upcoming weekend and next week. The dry pattern is still expected to continue through the weekend and into next week.
Tuesday – Friday:
Dry with mostly sunny days and mild through Friday. Highs into the 50s for the lower elevations and 40s on the upper mountains.
We continue to see inversions at night, limiting snowmaking. Looking at the sensors early Tuesday morning, it is 23 degrees at the base of Palisades and 38 degrees at 8000 ft.
Weekend Shift:
The pattern does shift over the weekend with cold air from Canada pushing into the northern Rockies and the Central U.S. The ridge builds just off the West Coast, and a trough tries to back westward into CA. That has been the forecast all week.
The change over the past 24 hours is the cold trough digging south farther east in the central U.S., with the high-pressure ridge nudging into the West Coast. That is pushing the source of the coldest air farther east, and has the trough not backing as far west into northern CA.
Still colder temperatures forecast to filter into the region, but not quite as cold as forecast previously. Highs drop into the 40s for the lower elevations Saturday and maybe 30s for Sunday, with 30s on the mountain.
Overnight lows are now expected to only drop into the upper 20s to around freezing. That should be cold enough for some snowmaking on the mountain, but marginal vs the colder temperatures previously forecast.
Early Next Week:
With the ridge near the coast nudging a bit farther east into the coast over the weekend, that trend is now forecasted to continue into Monday and Tuesday. That is moderating the forecasted temperatures for early next week as well, with highs now forecast to warm into the 40s again by Tuesday. Overnight lows are also forecast to not be as cold either.
Another Cold Front:
The ridge is still forecast to start retrograding a bit starting Wednesday, with another surge of colder air from the north with a trough digging west into CA. Highs drop into the 30s down into the lower elevations, and maybe 20s for the peaks, with 20s at night and maybe a bit colder. That could finally bring us more optimal snowmaking.
We could see some snow showers with the cold front next Wednesday (the 3rd). We’ll keep an eye on that as we get closer.
Long-Range Outlook:
Yesterday, there was a lot of agreement on the pattern and teleconnection forecasts lining up with what would typically shift us into a stormier pattern by the end of the 1st week of December. Although I mentioned that the active phase of the MJO seemed to be a bit out of sync, and may be a sign that it’s a little too early for a big change.
There is still fairly good agreement that we shift into a -PNA pattern with the ridge retrograding westward in the Pacific away from the West Coast by the 1st weekend in December, with troughing over the West Coast opening the door to storms.
The ensemble mean models still show near to slightly above average precipitation possible between the 6th – 10th. The deterministic and control models still show some storms moving through during this period. But this morning, some red flags have started to show up that could mean weaker storms or a shorter duration of an open storm door.
We’ll continue to watch the trends. I don’t like forecasting out beyond 10 days as forecast model accuracy falls off a cliff historically, but being in a prolonged dry period, we try to look for signs that storms will return…
BA
