Arctic air intrusion into much of the US east of the Rockies early next week.
Upper air pattern is currently transitioning to allow dense cold arctic air over northern Siberia to cross the north pole and enter NW Canada late this week and this weekend and then plunge southward into the US late this weekend into early next week. Forecast models have generally come into some agreement that the upcoming pattern will bring sustained colder than normal temperatures to much of the central and eastern US including Texas by the first week of January. In addition, the pattern aloft tends to favor a least some degree of potential for upper air disturbances to cross over the southern plains within the cold air mass and produce winter precipitation.
Initial surge of cold air will arrive in NW TX late Sunday and then quickly spread to the coast by Monday morning. Think the ICON has the best handle on the quick surge of the cold air as these shallow dense air masses tend to move faster than guidance suggests and usually come in colder. All of SE TX should be post front within the colder air mass on Monday and temperatures may end up falling into much of the day into the 40’s and 50’s under gusty northerly winds. A line of showers and thunderstorms will likely accompany the front. This initial surge does not currently look overly strong with lows around freezing into mid next week and highs in the 40’s and 50’s as it appears the brunt of the coldest air passes east of TX toward the MS valley and the mid south. With that said…we are talking about a week out and should a trajectory move down the plains evolve this will bring colder air toward TX with colder temperatures…so this will be something to watch in the guidance trends over the next several days.
Guidance is also hinting off and on that energy will hang back in the trough to the southwest of Texas allowing moisture to funnel over top of the cold surface air. This starts to raise some question on winter precipitation chances in the mid to late week period for next week. For now it is too far out and uncertain to really have much of an idea what we could be dealing with (rain, snow, freezing rain, sleet) as temperature profiles and moisture amounts are unclear.
What we know:
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- Colder below normal temperatures will arrive over the area starting late Sunday into Monday and remain in place all of next week and potentially longer.
- Freezes (upper 20’s and low 30’s) are possible for much of the area as early as Tuesday morning of next week
What we don’t know:
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- Exactly how cold the incoming air mass will be and if additional surges of cold air later in the week lower temperatures more than currently expected
- What if any type of precipitation may occur within the cold air and what if any impacts may result
- How long the colder air mass will remain in place
Best course of action at this point is to monitor forecasts daily for trends and changes and have cold weather winterization supplies available if needed next week.
