I am becoming convinced that May and June are out of sequence this year. As crazy as 2020 has been thus far, why not?
I reached this conclusion after sunset arrived around 1930 on Monday evening, except there were no stars, and the evening light was a deep blue-green. That’s not a combination that presages fair weather.
A batch of storms had formed over the eastern rampart of the Rocky Mountains in far southern Colorado and northern New Mexico. This is very normal, and is part of the so-called Southwestern Monsoon. However, those storms tend to form a line, running north to south, and stay that way as they sweep out of the mountains and across the High Plains. Regionally, we call it the broom, because it sweeps rain across the land. Since it is a line, severe weather tends to be mitigated and dampened down. That’s June-early July, before the summer doldrums set in (aka a ridge of high pressure that blocks storms and shifts the steering winds.)
May’s storms tend to be more isolated and ferocious. May and June are “severe storm” months. That’s when the combination of cold-front, low pressure, and “dry line” or sharp border between desert air and Gulf of Mexico air makes life . . . sporting. As in “softball-sized hail and eighty MPH winds” sporting. The more isolated storms tend to be stronger, and with the front and low giving them more energy, the storms last well into the night. Oh, and tornadoes tend to come with these systems, caused by the same feature as makes the “Oh that’s just excessive” hail.
There’s also the “popcorn” showers, which bubble up, rain, maybe drop pea-sized or smaller hail if they feel frisky, and then go away.
Monday night’s system produced a massive cluster of storms, and a few monsters that formed ahead of the main batch, then turned at right angles to the cluster. My readers from the rest of the Plains are all saying things along the lines of, “Head for the basement,” or “I hope you had really good crop/auto/roof insurance,” about this time. For those not familiar with Great Plains weather, storms that form ahead of a line/cluster and/or that turn right tend to be very strong and laden with large hail and possibly tornadoes, as well as sending very strong winds ahead of themselves. Monday night skipped the tornadoes, at least as of last I read, but the hail and wind tried to make up for it.
The storm complex consolidated into a very large mass of mess that shifted from southwest to south-by-southwest movement, and developed a crimson bow-echo on the leading edge. This means very, very stout winds racing ahead of the complex, winds that can exceed Cat 1 hurricane speed. Purple* hail-cores marched along behind the bow echo.
Ahead of the storm, the sky turned dark an hour and a bit before official sunset. The light took on a very deep teal-green hue, one of the warning signs of a tall, nasty, hail-rich storm. It wasn’t the green of a day-time hailer, but had more blue to it. I can’t think of the last time I saw that shade in storm light. By this point, the complex had produced tennis-ball sized hail and 80 MPH winds, sending people all over the area diving for cover. Oh, and flooding rains came along, too. A typical May storm mass, in other words, but in late June.
Did I mention I don’t like this sort of heavy weather? And that this made three nights in a row of it? At least it came before midnight. Once the rain and wind began pounding RedQuarters, I relocated from my usual chair under a skylight to someplace less loud. We have skylight shields, but the roar bugs me. The cat followed, and hung around in the quieter part of the house as I finished unpacking from the weekend and then read. At one point I looked out the front windows, and couldn’t see the house kitty-corner from RedQuarters due to the blowing rain. Interestingly, the leading edge of the storm didn’t have all that much thunder or lightning with it. The hail cores seemed to bracket my part of the city, perhaps because of the heat-island effect. Bits of tree and leaves soon littered the yard. I returned to the quiet part of the house and kept reading until the worst rain roar passed and the wind stopped whipping rain around the roof and against my bedroom windows.
RedQuarters got almost two inches in forty-five minutes. The official reporting point on the east edge of town got around a quarter of an inch. This is normal, actually, although sometimes the official total is higher and RedQuarters gets two drips and a spitter. The gutters overflowed with wild abandon, so the next morning Dad Red cleaned out the gutters. The two water troughs filled in the first ten minutes. Both had been completely dry, so that was at least 250 gallons pouring off the roof and out of the gutters.
This is May weather, not late June. *SIGH* I want the broom, not a derecho-like bow-echo or screaming winds, thank you! But we needed the water, and even as fast as that blew/fell, there wasn’t much run-off, based on the debris line in the street the next morning.
*On the National Weather Service and aviation radar, the highest intensity is red. (If you see black in the red, it means run away because the stuff in the air is overloading the radar. This is Not a Good Thing.) Like rock band amps**, the three local TV stations have radar packages that display red plus two, those two being magenta and purple. A purple hail core is generally baseball sized or larger, at least in the clouds.
** This is Spinal Tap joke.
Cat Rotator's Quarterly 
Your storm line made it to us on Tuesday morning. Old NFO, Miss D. and I were having a final breakfast with our guests from Utah when the clouds opened. It was a real gully-washer, although fortunately without hail in our immediate vicinity. Driving home afterwards, we hit patches of pretty deep standing water on I-44 and US 287, deep enough to stagger the car as we hit it and shut down the cruise control. There were areas of rain where, even at their highest speed, the windshield wipers couldn’t cope, and visibility dropped to dangerously low levels. Not fun.
That was our Monday in the east, except no hailstones. Torrential downpour in late afternoon, at least 2″ in 30 minutes, washed out about half the dry-bed rework for runoff control – looked like a full stream. Finished the rework on Tuesday in time for a heavy downpour at night. No apparent runoff problems, no stones or clay lifted and moved 50′. Troughs or rain barrels sound like a good idea, and I think we now have space to place them and tie in.
I once had to work through one of those line storms in the South, because that was excellent data we needed. About halfway through, we could feel the heavily built building creak and sway, and could hear wind shrieking around every edge and corner. Just kept glancing at the open door for the shelter, in case the storm turned things up to 12.
You might check your local and state laws if you rain barrels will be visible from the street. Some states and counties do not allow people to have cisterns and the like (Colorado being the most infamous).
Mine can hide behind the house and probably under a deck. Anything that helps with water runoff control, on steeper slopes, gets a blind eye treatment. Water rights are not as big a concern.
Off Topic, but my Beagle Lilly got me up too early today. She reminds me of Tay. 😈
Of course, unlike Tay she can’t tell me exactly what she wants. Mercy or Not? 😉
I suspect your TV station is using the hazard radar data from the NOAA hazard web page. https://www.wrh.noaa.gov/map/
FWIW, this is a pretty informative map. It used to ignore warnings east of the Rockies, but it looks like the map is now good throughout the US.
Severely intense storms around here get a white/magenta-pink core, but we’ve been happy not to see the purple core. The colors around 80dBZ look too close to those at 15-20 for my taste, but I assume if you get storms that strong, the meaning of the colors should be obvious. OTOH, when it’s that nasty, colors are the least of your worries.
All three stations have their own radars and data processing systems. In fact, at one point, two of the stations had better radar and computer systems than did the regional NWS and NOAA. One station had an extensive pin-point reporting network (SchoolNet regional) but the lead meteorologist retired and they are not currently tapping those data.
I’m sure there’s some data overlay and sharing, especially for hazards.
On the bright side, if you were more comfortable with such weather, you’d be less effective at describing it.
True. I suspect, having survived a very near miss by an EF-4 tornado as a small child, and two later near misses, I’ll never get truly mellow about severe thunderstorms.
Concur. Except that usually the “only severe” kind of thunderstorm feels good, while the “bad severe” makes one feel terrible. Sinus weather radar!
I think this storm system is the one which hit yesterday morning around the time that I usually walk the dogs! Turned almost sunset-dark, all of a sudden, and when I took the dogs on leash out on the porch (armed with raincoat and umbrella) both dogs looked at the rain sleeting down and said – ‘Ummm … no. Don’t have to walk that bad, Mom.’ Well, Nemo abominates the cold and wet, and Benjy may have run away from his former home during a very bad storm, so I was indulgent. We walked about an hour later, when it had all cleared up.
Not as impressive as Sunday morning, but it was ‘sporty’ Tuesday… But most of it had bled off overnight, although we did get 1 1/2 inches of rain. Glad the big hail missed y’all!