The long-range ImpactWeather forecast continues to indicate the possibility of a major change in the weather pattern, and that change will deliver much colder weather just before Christmas for most of the Lower 48. Even though confidence in the forecast is still on the low side because we’re examining a time period beyond 10 days, the forecast data is trending toward the colder pattern. Currently it looks like a strong Canadian cold front will surge across the Great Plains and to the northern Gulf Coast by the 22nd bringing breezy and much colder air as it passes by.
Right now it’s a bit too early to predict exact temperatures, but this type of air mass — if it does materialize — could bring a risk of a widespread light-to-moderate freeze to the upper Texas Coast (not terribly unusual on its own, but a significant departure from what is expected earlier in the week), to the coast and areas to the east. By Christmas Day it appears the coldest air will continue moving east, but we may see a storm system approach from the west bringing thickening clouds and an increasing risk for rain across southern and central Texas during the day with lingering chilly temperatures. This storm system will continue pushing off to the east as Christmas week continues, although the temperatures — even as soon as the day after Christmas — are indicating a slight warming trend (or perhaps steady) for the central Gulf Coast states. Meanwhile, the northern third of the U.S., from the Rockies eastward to New England, will also be on the receiving end of much colder weather, though this area should be mostly free of snowfall on Christmas Day.
We’ll have a more refined and higher-confidence forecast in about three or four days as our information becomes more focused and reliable.