Tuesday 21 March 2017

Wildfires, Scorching Summer Heat Strike Central and Southwestern U.S.

March Climate Madness — Wildfires, Scorching Summer Heat Strike Central and Southwestern U.S. By Winter’s End


20 March, 2017

In Colorado today the news was one of fire. There, a wildfire just south of Boulder had forced emergency officials to evacuate 1,000 residents as more than 2,000 others were put on alert Sunday. Smoke poured into neighborhoods as dead trees killed by invasive beetles or a developing drought, exploded into flames. Depleted snowpacks along the front range of the Rockies combined with temperatures in the 80s and 90s on Sunday to increase the fire risk. Thankfully, so far, there have been no reports of injuries or property loss. A relieving contrast to the massive fires recently striking Kansas, Texas and Oklahoma — where farmers and communities are still recovering.

(The ignition source for the recent fire near Boulder appears to be due to human activity. But the on-the ground climate conditions enhancing tree deaths, reducing snow packs, and blanketing the region with record or near record heat increases the likelihood that a spark will turn into a dangerous fire.)
The record heat building into Colorado on Sunday and contributing to increased wildfire risk had spread up into the Central U.S. from the Desert Southwest. 

There, cities like Phoenix have experienced summer-like heat for at least the past week. On Sunday, the city saw a second day of record temperatures as the mercury hit 96 degrees (Fahrenheit). Saturday temperatures were almost as hot at 95 F. This was the 8th consecutive day of 90 degree (F) or hotter temperatures (the record stretch of 90 degree + readings for March was set in 1972 at 17 days). Meanwhile, forecast highs in the mid 90s for Phoenix today set the possibility for another record-breaker.


(Extreme heat builds through the Central and Southwest U.S. on monday as a wildfire forces evacuations south of Boulder, Colorado. Image source: Climate Reanalyzer.)

Today, heat is also expected to again build into the central U.S. as parts of Kansas, Texas, Oklahoma and Colorado are predicted to experience temperatures ranging from the upper 80s to well into the mid 90s. Pecos is expected to hit 96 F — which is about 20 degrees (F) above average for a typical March day. And in some regions, such as parts of Kansas, these temperature departures are as much as 25 F above normal. These extreme high temperatures are expected to break numerous records for the region as most of the previous record highs for this area range in the upper 80s.

The heat will bring with it more risk of wildfires and a front sweeping in on Tuesday could increase windspeeds and dry conditions for some regions. Record warm global temperatures, (spurred by human greenhouse gas emissions primarily coming from fossil fuel burning) which are aiding in the systemic, longer term, loss of ice and snow cover while increasing the rate at which drought sets in and spiking the top potential range of temperatures during heatwaves, appears to be combining with a post La Nina trend that typically favors heat and drying in the Central U.S. to set the stage for these extreme conditions.

Links:

Hat tip to Andy in San Diego
Hat tip to Robert Prue


No comments:

Post a Comment

Note: only a member of this blog may post a comment.