It’s been a while since a true, “Oh Lordy, what’s that? Nail down your hat here it comes!” norther flattened, er, refreshed the area. If the forecasts hold true, we’ll get one this coming week. I hope the kids have rocks in their pockets, small adults likewise. (No worries for me. I’m built low to the ground for just this reason, or so I believe.)
A real “blue ‘norther” comes in from the north-northwest. The sky to the north really does turn a distinctive dark blue, one that once you’ve seen it, you know to brace. Sometimes dirt will hide it (as happened when I was at an Airshow in Midland one October), but more often you happen to glance that direction, see the sky, and start racing around to tie down loose items, grab the laundry off the line, and drag the garbage cans into shelter. It is arctic air plunging down the long, treeless sweep of the plains, blocked in the west by the mountains. It accelerates but doesn’t warm much as it surges south out of Canada and Siberia.
The hallmark of a real norther is the temperature plummet. The wind goes from mild or calm to “Hoooooooleeeeee cats!” in the matter of a minute or two. The sky turns dark blue, then grey from the low clouds racing down as the cold air condenses any water in the atmosphere. The temperature drops tens of degrees an hour. My first norther was when I was in the fifth grade and had just moved to the High Plains. I walked to school in my shirt-sleeves (white Oxford shirt, tan pants if I remember right) at seven forty five that morning. A cold front was due, but hey! This is Texas in September. It’s been in the upper 80s. There’s no air conditioning at the school. Cold probably means lower 70s, right?
Ah, no. I could see the dark sky to the north and west during morning recess, but didn’t think anything about it. By 3:30 PM, when the last bell sounded and we all erupted from the grade school doors, the temperature was down in the 40s, with a wind chill in the low 30s. I was miserable trotting home. My backpack didn’t cover enough of me to help, either. That’s the last time my parents didn’t take that sort of weather forecast seriously. As a result, several times, I was one of the few kids forced to take a jacket when a norther was due. I was also one of the few kids not wailing about freezing my tuckus off on the walk home, or during recess.
Some people swear that animals can sense northers coming. I’m not certain, although the pressure change ahead of the front might do something. I do know that the first time I was at St. Angus in the Grass when a big cold front hit, it was crazy. The kids were wound up, the teachers were wound up, and I had no clue why the place had suddenly gone nuts. Then the north wind hit the building, and I mean that literally. We are out in the rural county, and there’s nothing between us and Alberta but a very ragged barbed wire fence with large gaps in it. As soon as the gust front came through, everyone settled down for the rest of the day. It was uncanny.
I anticipate that again next week. The students new to the region, or whose parents don’t remember the joy of northers, will freeze their little tuckuses off racing from the building to the car. The older students, too cool for a jacket, will grouse and moan about freezing their tuckuses off as they race for the cars. The teachers will grumble and moan as we brace against the wind and stagger to our cars. I will be wearing a jacket with a hood, because I don’t have any hat that I trust with 55 MPH north winds.
Cat Rotator's Quarterly 
Joule-Thompson Effect explains the cooling. (G = H-ST = PV – ST, for those who speak thermodynamics). Dense, cold air allowed to expand south will speed up on release, doing an isentropic energy drop. It gets cold, fast: Pressure drops a little, V(olume) increases a lot, S is constant, so T drops.
I’m inclined to the animals sensing it, from personal observations. They may pick up either the pressure change, or the very low-frequency tones from the gust front. Those subsonic notes get used to induce a sense of dread in movie soundtracks.
Probably a bit of adiabatic cooling as well.
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Animals can definitely sense a coming storm.
When you see the cattle casually strolling over and bunching up, all facing the same direction, it’s time to worry. Even though you can’t see the cloud yet.
Although it could be an earthquake about to hit. The reaction is about the same.
(And I think I’ve just discovered why groups of pedestrians waiting at crosswalks make me uncomfortable. Yay, self-discovery.)
Sounds “interesting”. 😉
Ah, that “drops from 90’s to 50’s” in the forecast. I am forewarned!
Yep on the animals, and if the cows lay down together, it’s gonna get UGLY… We had one hit here two years ago as Lawdog and I were going to lunch. Literally dropping a degree a minute. It had been 55 when we left, 45 when we got to the restaurant, and 35 when we walked out. Brrr…
Animals and…well, earthly events.
I was living in Topanga Canyon on the seaward side of the Santa Monica Mountains, 9 miles from the epicenter of the Northridge Earthquake when it hit. I was in the USAF, it was Martin Luther King Day (Observed) so as a Federal Holiday I didn’t have to report to duty that day. Despite not setting the alarm I woke up at 0430 anyway, and first coherent thought was “Why isn’t the cat sleeping on my feet?” The cat was always sleeping on my feet at 0430. Except that day. About 30 seconds later I got the answer. Zounds. Eventually found the cat hiding at the far end of the house in a closet under a small table.
At that time I also was overseeing the care of my girlfriend’s horse (she was out of state at the time). At daylight I went to the ranch/stable where he was being boarded. The stable was right on top of the peak ridge of that part of the Santa Monica mountains, closer to the epicenter. The staff had moved the horses from the stable buildings into a large corral.
All 25 or so horses were bunched up as close as they could get to each other, flank to flank. All were facing the same direction, the direction the earthquake came from. I’ll bet if you took a compass bearing along the spines of the horses it would cross the epicenter in Reseda. I dunno if they sensed it coming, but they sure knew where it came from.
Windy gusty weather really winds up my horse — he gets quite agitated by it.
There’s some thought that horses and other animals can feel one of the types of shock-waves from earthquakes, but I don’t know if anyone has come up with a good way to test that theory.