How the Grinch stole “coldness”

(That would be La Nina)

I spotted the Grinch who stole cold weather down my street last week! (KPRC)

Considering our average high for today is 67°, the fact that we have had highs in the upper 70s and 80s since November 29 is pretty remarkable. In fact, the past three days have been in the low 80s, nearing the all-time record high for December which is 85° (1995)! We get a cool down today with the front, but don’t rush to clean those holiday sweaters because you won’t need them long! We’re right back into the 70s Wednesday with low 80s by Friday.

You can thank La Nina for the warm spell. We’re going to have a La Nina winter. If you look at the latest graph below, the models all have the Pacific Ocean waters cooler than normal right into the spring. I’ve drawn those red arrows to the ‘mean’ model forecast which is the red line.

Sea Surface temperatures below the 0.0 line, or normal, are forecasted through June

What does that mean to us? Warm, dry weather. The La Nina pattern plants a big high pressure system off the Pacific Northwest which helps drive the jet stream to the northern U.S. and it’s that jet stream that pushes the cold air. We’ll see it buckle a few times for a cold snap, but cold snaps don’t last long with this pattern. Here’s NOAA’s explainer graphic on the weather we get from La Nina:

The blue line represent the Jet Stream which keeps the colder and wetter weather to the north

Thus, the forecast for December for the country, and especially for Texas, is continued dry and warm:

The full winter forecast plays the same:

The next three months look warmer and drier than normal!

An interesting upside for Texas

Of course, if you like shorts and t-shirts weather as opposed to donning a lot of sweaters for the season, then this pattern is your cup of cocoa.

I received an interesting release from bumper.com regarding fatal car crash statistics during La Nina winters. In a nutshell, the wet and cold weather results in more deadly car crashes certainly due to rain-slicked roads (and snow/ice covered roads. That’s bad news for the Pacific coast and Northwest, the Midwest and Ohio Valley, but good news for the states, like Texas, staying on the dry side. We see a better than 8% reduction in fatal car accidents during La Nina winters.

The blue colored states see fewer fatal car crashes during La Nina winters, while the red states see an increase courtesy bumper.com

The full report from bumper.com is right here.

I get asked a lot of if we could see a repeat of last February’s big freeze. We could, but a snap like that is generally ‘generational’ meaning once every thirty years. Still, last February’s first two weeks had a couple of days ranging from 75-80° which then cratered to single digits and teens mid-month. A week of freezing nights we’ll never forget.

I’ll review the big freeze in an upcoming blog. For now, enjoy the sweater weather tonight because the warm-weather Grinch is back faster than you can say “Whoville”!

Frank

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About the Author:

KPRC 2's chief meteorologist with three decades of experience forecasting Houston's weather.