Augtober, Relentless Rain, Fire & Tropics
Heard a new term from a fellow meteorologist today, and decided it was worth borrowing: AUGTOBER. This seems like a fitting word lately for those of you across the eastern half of the nation, where August temperatures are flirting with an October-like feel.
Case and point, Atlanta struggled to a high of 67 Friday, only the 16th time the high hasn’t reached 70 in August since 1878! Rain, low clouds, and a pattern called cold-air damming helped Atlantinians(another new term I just made up) feel an autumn chill. So what is cold air damming?
An area of high pressure is wedged up against the lee side of the Appalachians, held in place by a stationary boundary draped across the southeast. As upper-level wrinkles in the atmosphere move along this boundary, it’s pushing warm, moist air up and over a shallow, cooler pocket under the area of high pressure. In the winter months, this would be a perfect set-up for an ice event, but since it’s still summer, it means well below average temperatures and bouts of rain.
Speaking of rain, flash flooding continues to be a concern across parts of Alabama, Florida, Georgia & South Carolina. 48-hour rainfall totals have been impressive, and this is on top of rain over the past few days. Gauges in a few neighborhoods have pushed up over 8-9″! We can thank a huge dip in the jet stream(river of storm steering winds aloft) all the way into the Gulf of Mexico for drawing plentiful Gulf moisture into the southeast. More widespread rain is likely Sunday and Monday, before our pattern shakes and relaxes the widespread heavy rain threat.
The current jet stream pattern is about to shift east, allowing for hot air in the western U.S. to spread back into the eastern half. Areas waking up to lows in the 30s & 40s over the past week, will enjoy daytime highs in the 80s & 90s, with lows in the 60s. Summer isn’t over yet!
Heat, wind and very dry conditions in the west are fueling an expanding field of wildfires. This map, courtesy of www.HAMweather.com, shows the number of large fires currently burning. Conditions remain favorable for fire growth in many western states.
Explosive development occurred in the Beaver Creek fire, halfway between Boise and Idaho Falls. At only 6% contained, this fire jumped overnight from 65-thousand acres, to nearly 93-thousand acres! Mandatory evacuations have been ordered in the town of Hailey and some of the surrounding areas. The timelapse below shows haze and smoke from Boise. Air quality alerts are in effect, so be careful if you suffer from respiratory ailments in south-central Idaho.
I want to touch on the tropics before wrapping up today’s blog. As of this writing, Erin remains a very weak Tropical Storm entering the central Atlantic. She’s expected to drop below T.S. status sometime tonight, and eventually drift north by mid-week. Erin will remain a shipping lane headache, and have no impact on the lower 48. Invest 92-L(don’t you just love the beginning stages of storm naming in the tropics?) is weakly wobbling into the Gulf of Mexico. The disorganization of this system is thanks to our giant dip in the jet stream just to its north. Gulf moisture is being dragged out of the system, and pushed across the southeast. As our jet stream moves north again, conditions may briefly become favorable for slight strengthening. If named, he would be Fernand(fair-NAHN.) Models have shifted the track south into northern Mexico, which would still bring far southern Texas some squally weather either Monday or Tuesday.
Enjoy the rest of your weekend, and have a wonderful week ahead! Until next time-
Meteorologist Bryan Karrick