Brr!

[nuranar]

It's been an incredibly mild winter so far. Except for a very low-20s (F) dip in early Deceember (much earlier than we usually get what passes for Serious Cold), this winter has been mild. More than a few days have been in the 60s, and several in the 70s in the last 30 days. That doesn't mean it still isn't winter. And a hallmark of Texas winter is Sudden Change.*

This morning is probably the most striking example of a winter Sudden Change that I've documented. See the red circles:



In the hour from 7 AM to 8 AM, the temperature dropped 16 degrees.  Sixteen!!!


I've seen 20-30 degree temperature drops in the course of a morning, or an afternoon, or whenever a front hits.  That's spectacular enough, and leaves an unwary person in the position of going to work in comfortable shirt sleeves, and freezing on the way to the car in the evening. But 16 degrees in one hour is as sudden a drop as I've ever seen.  You can see from the blue circle that the wind had already shifted to the northwest, so the front had started coming in. The weather station just happened to catch the temperature extremes in its hourly recordings.

The front isn't even that strong. We've stayed steady at 43° for several hours since then, and aren't supposed to get much below 30° tonight. It's just the speed that it came in with.

Never a dull moment!

* For once Wikipedia continues to fail me, but I do have another link. An apparently Texas term for a very strong, very fast-moving cold front is "Blue Norther." Just as with this morning. Sometimes it is visible as a low, very dense line of blue-gray-black clouds approaching from the north-northwest.  These are the fronts that bring dramatic 20-60° temperature drops in 24 hours. They often seem to come when the weather's been warm; and since both warm and winter-like weather can happen anywhere from October to April, it's easy to be caught by surprise.  In North Texas it's not usually severe, but I understand that in the Panhandle these fronts used to be (maybe still are) dreaded by ranchers. They can bring very heavy snow, and combined with the wind, can lead to the the deaths of many cattle.
This is the closest picture I found in a fast interwebs survey to what I have seen and term "blue norther" clouds, although it doesn't actually show the leading edge - IMHO the most striking part. It does show some of the blue color.

Comments

[jordannamorgan]

Wow. That's some drop. :o

We've been having a pretty mild winter, too. Although we had one of those cooler snaps with upper-30s lows a couple of days ago, today we hit eighty degrees for the first time since Christmas Day. o_O

It's a good thing the weather is staying mild, because that warm December fooled the citrus into putting out blossoms/new leaves instead of going dormant. A serious freeze now would devastate all that delicate growth. (Plus there's the fern growers getting ready for Valentine's Day.) There's no dramatic cold in the outlook for now, so hopefully the farmers won't take a hit before winter is over.

We need rain, though. It's really dry, and brush fires are starting up. (However, that's unrelated to the burning of The Senator.)

[nuranar.livejournal.com]

One of my coworkers had a flat on the way to work. Weather was totally fine and warm. Tire changed and aired up, she finishes the drive to work, and is a POPSICLE by the time she gets into the building. Just crazy!

80, wow! I think we hit 76 sometime since Christmas, but that's as close as we've gotten. I do hope it stays warm for you - a cold snap would be disastrous for the farmers. My brother said that the "Greenland high" did not form this year, and that's why we're all having a mild winter. Apparently the Greenland high is a strong high pressure system that forms over Greenland, and it drives all of those really strong cold fronts that come down from Canada and the Arctic most winters.

Same here. We've had some rain, but definitely not enough. Usually we have extreme seasons back to back, so this mild winter after a scorching summer is totally unexpected; and I have no idea if this summer will be hot again or mild. But either way it looks like none of us are out of the drought cycle. :(

[jordannamorgan]

We had a little bit of light rain today. But then, my mother had watered her plants, which guarantees it will rain immediately afterward. :Þ

[sakka.livejournal.com]

16 degrees in one HOUR? Good grief!

Our weather has been insanely weird too. Before the "major winter snowstorm" (the only we've had this season) hit, the weather was 52 and rather spring-like. Also, it's been about in the 30-20s here, but Thursday, our high is... 11 degrees.. :|

[nuranar.livejournal.com]

I know! Crazy!

Huh - that amount of variation sounds like here, just adjusted for 20 degrees cooler overall. :D 11 degree is COLD!

[snowywolfowl.livejournal.com]

Wow, that is quite a drop and a good reminder that Momma Nature's never without a few tricks up her sleeve.

[nuranar.livejournal.com]

No kidding! That's why I read the forecast religiously.

[suededsilk.livejournal.com]

Whoa! And that's in the morning. 64° at 3 AM and 44° at 8 AM is just wrong.

[nuranar.livejournal.com]

Hee, I know it! Many of ours seem to come through about dawn. Many graphic forecasts have gone to showing the high for the day, and then a "down arrow" next to it. That indicates that the high will be reached early in the day (instead of late in the afternoon) and the temps will continue to drop the rest of the day.