The weather certainly hasn’t been feeling like a typical December lately. High temperatures on Thursday were generally in the upper 70s to low 80s across our region. Meanwhile, Cotulla, Kingsville and Alice all had high temperatures of 90 degrees. Friday’s readings may actually end up a degree or two warmer—matching or even breaking the record high temperatures for this date.

The current unusually warm pattern is the result of a the storm track staying well up to our north, allowing for a moderate wind flow off the Gulf of Mexico. In addition, warm winds of the plateaus of Mexico are mixing down to the surface across Texas. For this afternoon, clouds will decrease, leading to a partly cloudy to mostly sunny sky across the Hill Country and Central Texas. Across the middle Texas coast, the sky is forecast to be partly to mostly cloudy. Breezy conditions will be in place, with south winds in the range of 10-15 mph, with gusts to 25 mph. Afternoon temperatures are forecast to generally top out in the mid-80s!  (Note: Friday’s record high temperature for Austin-Camp Mabry is 81 degrees set in 1983. For Austin-Bergstrom, the record high is 83 degrees set in 1947).

A big change in the weather is forecast to take place Friday night into early Saturday morning when a strong cold front sweeps south through Central Texas. The front is forecast to reach the northern Hill Country around midnight Friday night, sliding south to the Austin about 3-4 am. The front will continue moving to the south and should push off the middle Texas coast an hour or two after sunrise Saturday. No rain is forecast with the front when it moves across the Hill Country. However, forecasts call for a narrow band of rain showers and thunderstorms to develop along the front when it reaches the Interstate 35 corridor. Atmospheric conditions may be unstable enough for a couple of the storms to be strong or severe—mainly over the middle Texas coast and Southeast Texas. The primary severe threats will be strong downburst winds and large hail. The Storm Prediction Center has placed Fayette, Colorado, Wharton and Matagorda Counties under a Marginal Risk (a 1 out of 5 risk) for severe thunderstorms through early Saturday morning. Rain amounts are predicted to remain under a quarter inch.

In the wake of the cold front, breezy and much cooler temperatures will be in place Saturday. Clouds are forecast to decrease from west to east Saturday morning, with a mostly sunny sky expected in the afternoon. A generally clear sky is predicted for Saturday night. Strong north winds with speeds of 15-25 mph and gusts to 30 mph can be expected Saturday morning through late Saturday afternoon. (You might consider securing all outdoor decorations and collapsing any outdoor inflatables). Wind speeds should decrease to 10-15 mph Saturday evening and drop below 10 mph around midnight. Saturday’s temperature is forecast to reach the upper 50s to low 60s.

Saturday night, the combination of a clear sky, light winds and a cold air mass will lead to the development of one of the coldest nights we’ve seen so far this autumn. Folks across the Hill Country and Central Texas should make plans to protect tender vegetation.

  • Across the Hill Country, temperatures are forecast to fall below freezing, with lows Sunday morning in the upper 20s to low 30s.
  • Across Central Texas, temperatures are forecast to fall close to freezing at most locations, with lows Sunday morning generally in the low 30s. (The Austin-metro area will likely see a low in the mid-30s).
  • Across the middle Texas coast, lows Sunday morning are forecast to be in the upper 30s to low 40s.

Sunday’s weather is shaping up to be fantastic! Under a sunny sky, expect afternoon readings to top out in the low and mid-60s. Temperatures won’t be quite a cold Sunday night. Lows Monday morning are forecast to be near 30-40 degrees across the Hill Country, in the low 40s across Central Texas and in the mid to upper 40s across the coastal plains.

Warmer temperatures will make a fast return early next week as this weekend’s cold air mass quickly moves off to the east, bringing a return of southerly winds. Dry conditions are forecast throughout the week as our region comes under the influence of a large ridge of high pressure parked over the southeastern U.S. Southerly breezes will bring increasing moisture levels beginning late Monday.

Monday is shaping up to be mostly sunny, with a high temperature near 68-72 degrees. Weather conditions Tuesday through Friday will feature widespread nighttime and morning clouds and partly cloudy afternoons. Daily high temperatures are predicted to be in the upper 70s while lows will generally be in the low and mid-60s.

Longer-range forecasts call for the development of a more unsettled pattern next weekend. A Canadian cold front is predicted to push through the area Saturday, bringing cooler temperatures. At the same time, a trough of low pressure is predicted to set up over the southwestern U.S., causing the development of overrunning clouds and rain. High temperatures should trend down to the 60s,with lows in the 50s. More details on this change in the pattern in Monday’s report.

Comet Leonard

Northern Hemisphere skywatchers will have a limited window in which to view Comet Leonard, which has become the brightest comet of the year. However, it is still not quite bright enough to be visible to the unaided eye.  The comet appears to be at its best viewing right now! It’s at about magnitude 5.5, and will appear low in the due east sky Saturday morning the 11th. Go out about 90 or 100 minutes before sunrise. The comet will be about 10° above horizontal. You’ll almost certainly need binoculars or a wide-field telescope to detect it. On Sunday morning, Comet Leonard may be just a trace brighter, but it’ll be much lower and more involved in morning twilight.

Later this week the comet will reappear very low in the west during evening twilight. But by then it will unfortunately be fading in brightness.

For the world’s mid-latitudes, Saturday morning will most likely be the last chance to catch the comet at peak brightness in a dark sky.

Have a great weekend!

Bob