Weather Blog

It was 90 degrees in Minneapolis today, which is certainly a pretty warm start to June, and tomorrow and the weekend will only get hotter. Heat waves are certainly newsmakers, and in particular, they are big news when they arrive in the northern US. All this is true, and really, it’s not the most interesting part of this particular heat wave. Take a look at the forecast highs for Friday.

There is the typical hot spot in the Mojave, but otherwise, the warmest part of the country will be…. North Dakota? The interesting part of this heat wave, to me, is that it completely bypasses places to the south. The forecast high in Bismarck tomorrow is 101! Unintuitively, the forecast high in Austin tomorrow is 80, a full 20 degrees cooler. I don’t have to tell you this, but that’s not how it usually works!

Why is this going on? The answer is told in the upper air forecast. Take a look at the flow pattern forecast during the day tomorrow. I have added some arrows for your benefit.

The pattern over the US is tilted. The upper level trough over the eastern part of the US takes a westward turn and heads through the southern Plains. Forgive me, because the axis of the trough in the south is a little further north than I drew it, but the result is the same. Moisture is being drawn to the Red River Valley, and then it streams into the eastern Great Lakes, keeping the entire tract covered in clouds and rain.

Meanwhile, a ridge axis runs from the southwest towards the Upper Mississippi Valley. Remember how I noted how hot it was in the southwest? Well, that is where the air moving into the Dakotas is coming from. Combined with the scouring effect of the Rockies, the dry air can warm even more during full daylight.

When this pattern sorts itself out, the hot air won’t go anywhere, but instead of shipping off to the northeast, the moisture entering through Texas will find a route north. Until a cold front comes late next week, the heat of this weekend will become hot and humid.

It’s only June 3rd. and the summer is off to a hot, hot start in the Northern Plains.

We made it through what is historically the stormiest month of the year, and made it without many devastating headlines. Now we just need to tackle fire and hurricane season with so little bad news. This month, the best news for a forecaster belongs to The Weather Channel, who always seem to do well in the spring storm season. Kudos to them. Here is the look at the total wins for the year to date:

There has bee quite a bit of severe weather in the last week, but it hasn’t really been a story in the news. Strong storms did a good job of avoiding large population centers, and never really threatened to move somewhere moer ominous. Any weather outbreak looks as though it will have to come at another time, as the severe weather in the Plains is going to wear itself out.

Tornadoes are common this time of year, and in the High Plains, thanks to the changing of the season, and the topographic advantages of the region. The flat, generally low density population of the region makes it popular with storm chasers, both of the academic, researching variety, and the thrill seeking tourist kind. The availability of weather data to the public has meant that May in the Plains can be thick with chasers, especially when the weather is busy. Such was the case over the last week, when tornadic activity was seen over many days from the Texas Panhandle to southwestern Nebraska.

Many videos were taken and twisters spotted, all without much harm to life or property. Call it a pretty successful chase season for all involved (except those who justifiably are a bit miffed by the idea of disaster tourism, especially in their home area).

The region, as I said, is a topographically perfect partner for storm chasing. The pattern this week set itself up nicely, and was long lived enough to encourage chasers to make the trek. There weren’t big areas of low pressure that dived into the region to make for dangerous outbreaks, like we see in the southeast or Ohio Valley when outbreaks occur there.

The Omega block over the eastern US allowed for warm, moist air to pump north on the western flank of the ridge, priming the pump for strong storms. In this environment, the tightly spinning lee troughs developing in the leeward side of the Rocky Mountains were able to trigger thunderstorms that were often well organized enough to drop tornadoes, often big, nasty photogenic ones that could be filmed from a distance.

In this case, they didn’t find any population centers, which is what everyone wants. With any luck, important information was collected. At the very least, cool images were taken.