Once again, we are seeing a great number of fires, sweeping the western portion of North America. Fires are a natural occurrence, and good for the regeneration of hardwood forests, but with the urban sprawl moving ever deeper into the wilderness, the threat of fires to human livelihood increases, as does the threat for fires to be started by humans, either by accident, such as the Carr fire in northern California, or on purpose, such as the Holy Fire in southern California.
While the threat for fire is visceral in the west, the threat of smoke is real for much of the rest of the country, from something as simple as reduced visibility and haze, to poor air quality, respiratory issues and other safety and quality of life concerns.
The upper level pattern is fairly zonal, which is to say that the US’s upper level flow is moving predominantly west to east without many interruptions. The lone exception is a weak trough in the Pacific Northwest. The consequences are smoke pressing due eastward, right along the northern tier of states, both because of the predominant westerlies, but also because of the southerly flow within the trough, funneling California smoke in with the Washington and British Columbia haze.
One variable that helps to limit the amount of haze or smoke in the atmosphere is rainfall. It essentially cleans the skies up, as soot and smoke particles become captured in the water droplets, and the denser smoke gets scattered by updrafts. The southern US is enjoying some intermittent thunderstorms, while the threat for rain will shift northward for next week.
I think this might be the first time this has happened, but I haven’t been able to verify it quite yet. I think this might be the first time we’ve had WeatherNation step up and have the top record for an entire month of the year, but alas, they claimed the July crown, putting aside an affinity for the NWS forecast and a series of technical issues and display shortcomings. Congratulations, Weathernation, you’ve earned it.
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.