We’re 2 months through the official hurricane season now for the Atlantic Basin, and this is usually when things start ramping up. Upper-level shear starts to significantly weaken and waves off the African coastline have better odds of finding favorable conditions to develop. Looking out at the Atlantic, however, there really isn’t much to write home about. There’s a disturbance which the NHC has listed at a 30% chance of developing into a tropical cyclone over the next 48 hours, but given the relatively cool waters around 35N/50W and it’s slow northeastward movement, odds look slim at this system developing into anything of real concern. There’s been a significant African dust layer over the more tropical areas of the Atlantic over the last couple of weeks which has really put the kibosh on anything getting revved up. For the next several days, looks like things are pretty benign!
In the Pacific, however, things are a LOT more active. Ileana and John are spinning their way not far from the Mexican coastline, the latter looking like it could be a major hurricane as it approaches Baja CA. The storm should remain off to the west of it so that’s encouraging news.
Of even more importance is Hurricane Hector out over the Central Pacific. It looks to keep a mainly westward trajectory over the next several days, which is good for Hawaii since it currently has maximum sustained winds of 155mph, just a tick below Category 5 strength. The big island has a tropical storm watch out for it and given model forecasts, a brush from Hector is all that it looks like it will get. Given its intensity, I’m sure they’re more than okay with that.
As we push our way into the Dog Days of August, Summer is in full swing throughout the country. Well, it seemed that way anyways last week. The Desert Southwest and Southern Plains were absolutely scorching with temperatures pushing their way into the 110’s! Waco hit an all-time record high of 114F, breaking the previous record of 112F. Austin and Dallas-Fort Worth also broke daily high temperature records during the heat wave, cracking 107 and 105 respectively. As if that wasn’t hot enough, Southern CA and the rest of the Desert Southwest was an inferno. Palm Springs hit an incredble 121 degrees while Death Valley even set a new daily high record (which is impressive for them), topping out at a ridiculous 127 degrees. In fact, Death Valley set a record for the hottest month on record anywhere in the world for July, with an AVERAGE temperature of 108.1 degrees as 21 days in July hit 120+ degrees. July 2018 broke the previous record for hottest average month in the world set… just last July, when Death Valley averaged 107.4F in 2017. Hopefully July 2019 spares Death Valley a bit, but let’s not hold our breath.
A bit of an extreme on the other side was felt this morning as unusually chilly high pressure system shifted through the Upper Midwest. MSP dipped to 57 this morning and could only muster a high of 72, 11 degrees below normal. That’s nothing compared to what happened at International Falls though, the Icebox of the Nation. It lived up to its’ moniker today, bottoming out at a downright chilly 34 degrees, crushing the previous record of 41 set exactly 100 years ago. In fact, between July 1 and August 2nd in International Falls history, only 1 other morning has ever gotten that cold, July 11, 1911 got down to 32F. Certainly not summer-like this morning over the northland!
This video via Dakota Smith and Jesse Ferrell shows a lenticular cloud, which is a disc like cloud that is formed above an obstruction, thanks to the change in relative humidity on the lee side of the mountain (or whatever obstruction you find the cloud formed by). They have been confused for flying saucers before, and surely you can see why, looking at the cloud form and reform in the video above!
High pressure in the center of the country has steered an area of low pressure north along the East Coast through the Mid Atlantic and western New England, while ridge riding showers and storms on the back end of the ridge have led to persistent rains in the Rockies.
Unfortunately, the natural result of heavy rain over the undulating terrain of both regions is flash flooding. Here are stories from Washington and Denver. Below is some imagery for Rock Creek near Washington DC.
ABC also has a comprehensive video package of the dangerous conditions across the eastern Seaboard and the Colorado Rockies.
Fortunately, both situations are on their way to alleviating, with low pressure shifting out of New England, and high pressure shifting further to the east.
All through the spring, we in the eastern US lamented the long struggle to break through into the summer, as a standing trough remained entrenched over the eastern US, bringing significantly below normal temperatures to the area. The outlook maps looked a lot like this:
The Earth is tilted more directly at the sun, so the temperatures aren’t going to be sub-freezing, but the highs are going to be well off normal late this week. The west, as it was in the spring, will swelter, though now instead of an early, unnoticed summer, wildfires are going to be erupting across the region.
One difference between the patterns is that the jet flow isn’t as brisk, which means the jet stream is going to be a bit more pliable. Expect the cooler temperatures in the east to warm back up by the time next week begins.
While severe weather was expected in the Corn Belt on Thursday, it certainly took on a much more momentous impact than was forecast. Of course, the nation grieves for the victims of the duck boat disaster in Missouri, which occurred as the result of a squall line causing the boat to capsize. Further to the north, where there had also been severe weather in the forecast, storms became supercellular, and dropped tornadoes east of Des Moines.
The radar imagery resembled tornado outbreaks seen in Oklahoma during the spring time, with discrete supercells rolling through the countryside. Not only does this typically mean strong tornadoes, but also often allows for clear video of the twisters in action. Case in point, the two funnels northeast of Des Moines, which ultimately struck the suburb of Bondurant, captured by traffic cameras.
A more traditionally videotaped tornado swept through Marshalltown, which is is about 50 miles to the northeast of Des Moines. Here, the tornado is seen toppling the cupola of the historic county courthouse.
Fortunately, despite the tornadoes in Bondurant, Marshalltown and also in Pella, south of Marshalltown, there were no deaths. Damage was significant, but central Iowa will be able to bounce back in no time.
Summer rolled around last month and really took our breath away, especially if you lose your breath easily in the heat. Not only did summer roll around, but we spent an exorbitant amount of time in Texas, and heat waves gripped the nation. It was the National Weather Service who collected the top forecasting title for the month, knocking everyone else down a peg.
This is your annual summer reminder that large scale wind events, like derechoes (long lasting, large wind storms) can be just as, if not more destructive than tornadoes. In fact, the storm in this video did damage as far north as Minot on Thusday, and eventually worked its way through northern Minnesota overnight into Friday morning.
Pay attention to the warnings you hear on TV or the radio, and recognize that there is danger in severe thunderstorms just as there is in a tornado.
Take a look at this current radar image from Oklahoma City. It promises a very bumpy evening for residents of the Sooner State.
Let’s address that big line that rolled through Oklahoma City just now. Note the narrow blue band ahead of the primary line. That’s likely not actually precipitation, but rather the dust and particulate forced ahead of the line by very strong winds rushing ahead of the line. Usually, we would call this an outflow boundary, but that would indicate a collapsing storm, which this storm is not doing. It’s just hauling through Oklahoma, generating a lot of straight line wind.
If you look to the west, there are a couple of smaller bow echoes, which are undoubtedly producing strong winds of their own, and given their stronger radar returns, might be contributing some small hail as well.
All these storms are riding a mostly stationary boundary, which is the case with derechoes. Those straightline wind events are generally long lasting (expect to see this storm in Arkansas or Louisiana tomorrow morning) because they have the stationary boundary to ride, and produce widespread damage, thanks the to the breadth of these storms.
Fortunately, the storm is through Oklahoma City for the night, and the largest town it should clip overnight is McAlester, but places like Pine Bluff and Shreveport should be ready for an early wake up call!
It’s been a Katy Perry-esuqe couple of months over the Upper Midwest, by that I mean it’s been “Hot N Cold”. MSP had their 4th coldest April on record then rebounded with their 2nd warmest May on record, which had their longest May stretch ever of 6 straight days of 90F+ days (and included the first 100F reading in 6 years!). June so far, has been very moderate, with no days reaching more than 9 degrees either above or below normal. Dew points today actually bottomed out in the upper 30s in the early afternoon hours, making for a picture perfect day across the region!
The heat and humidity will be returning with a vengeance once again this weekend as an area of strong low pressure is expected to push up into the Dakota, tapping some gulf Moisture to pump it up through the Plains and fuel thunderstorms over the Northern Plains and into the southern Canadian Prairie Provinces. Temps around here look to push into the 90s over the weekend with juicy dew points returning to the low 70s. We’ll see how long it sticks around or if it will settle back down towards normal, where this month has been so far.