Extreme heat warnings for eastern & central U.S.

M.T. Cranium

I decided to make this a separate topic to alert non-weather-forum Boards members who might have business or vacation plans in the U.S.A. from today through next week.

It has been scorching hot all through June in states like Colorado, Kansas, Nebraska and Oklahoma, but these are not prime travel destinations and in general it has been more moderate further east.

However, that severe heat has been spreading east in the past few days and is now sweeping to the coast, so that from today on, well into next week, highs will be into the heat prostration range of 39-45 C in almost all parts of the eastern and central U.S. (south of a weak frontal zone from Minnesota to central Ontario to northern New England). This would include all the major cities and parts of southern Ontario in Canada at times also.

Heat on this scale is normal for Phoenix and Las Vegas, and sometimes affects urban areas in California. During this heat wave, Phoenix and Las Vegas will remain in their normal hot climate but it won't be particularly hot in California, so if you're headed there, expect 25-30 C inland and 15-20 C near the Pacific. Also it will be much cooler in the northwest U.S. and western Canada which have seen almost no hot weather yet this year.

Getting back to the main item here, the current 1200h local temps are about 32C in NYC, PHL and DC and at 1100h local it is near 35C in Chicago, however, the super heat has just begun to mix down to the surface today and I'm expecting even hotter readings at similar times tomorrow and Saturday. The highs today will be around 40C in Chicago and most of the Midwest, but 33-35 along the east coast which is not quite into the hottest part of the air mass yet. Tomorrow looks slightly cooler in Chicago but up to around 38-42 C in the east coast cities. A few "hot spots" could reach 45 C which is 113 F in "old money." (The heat wave has already produced 115 F for new June records in central Kansas and southern Nebraska).

Some of the daily records recently tied or broken were set in years such as 1911, 1936 and 1954 that went on to set all-time July records in many locations. The July 1936 heat wave was responsible for thousands of deaths in larger cities including Toronto, Canada due to the lack of air conditioning in those times and the combined effects of scorching daytime heat and no relief at night (overnight lows were sometimes as high as 28-30 C).

For weather-conscious readers, the recent thickness values on the 500-mb charts have been as high as 601 dm in the severe heat zone, and 850-mb temperatures have been 35-40 C (of course when you're in eastern Colorado you are almost at 850 mbs at the surface), this morning's maps show 32 C at 850 mbs over St Louis Missouri which is much lower down (around 975 mbs equivalent). So this extreme heat parameter is making steady progress east now as the mid-continent ridge flattens out with TS Debby weakening and well off to the southeast. Another unusual feature of this heat wave will be hot northerly winds into Florida, possibly setting new records there. Although it's almost always hot and humid at this time of year in Florida, they rarely get much above 34 C but this set-up could drive 39-41 C temperatures well to the south of Gainesville before sea breezes modify the readings towards the mid-30s.

The heat does not look set to break down very quickly, once established it may remain almost this hot for weeks and periodically ramp up to record values with surges of "Sonoran" heat although in this case the source region is the scorched semi-desert that is western Kansas at present. Most of Colorado and Kansas have dried to the point where any small grass or forest fire can quickly spread into a large-scale inferno. This has caused widespread devastation around Colorado Springs with forest fires coming out of the higher mountain regions into the suburbs of the city. Kansas has very few wooded areas but grass fires have become a problem, with thick smoke closing some highways and 30-40 mph winds yesterday spreading one or two of these grass fires considerably.

nilhg

And the same heat looks as if it's going to drive a classic weather market in corn, despite having one of the best sowing seasons on record, the heat seems to be going to really affect a large part of the crop.

Look at how the futures price has risen since the heatwave started.

M.T. Cranium

The southern part of the "corn belt" is especially hard hit by drought. That would be states like Arkansas, southern Missouri, southern Illinois and Kentucky. The northern part like eastern Nebraska, Iowa and north-central Illinois into Indiana and Ohio all have a maturing crop despite dry conditions whereas further south the drought has been more extreme and a contact of mine on another forum just posted "farmers around here (w KY) have lost their crops already as this severe heat begins, with no sign of significant rain during five very hot days to come."

The maturing (if perhaps stressed) corn crop is always a natural source of evapotranspiration and dew points usually reflect this in June and July, with inflated readings common in southern Iowa and central Illinois, readings that you don't find anywhere else in the U.S., into the 80s (F) or 27-29 C (I have seen 31 C). These tend to reduce the temperature slightly but the humidex then increases more than surrounding dry places, today for example there was a reading of 37/27 at Shenandoah IA giving a humidex of 48 C. I recall seeing 55 C humidex in the severe 1995 heat wave from something like 40/31.

Record highs today at almost all large cities in the Midwest, or close calls against 1936 records (that was building to the worst heat wave ever experienced in the region by July). For example, 40 C at Indianapolis, 41 C at Evansville (southern IN) and 42 C at St Louis.

nilhg

I don't want to hijack your thread MT but for anyone interested in the effect of the weather on US ag (and that affects all of us because it's the main driver of prices across the world) the comments in the link below are interesting,


http://www.agweb.com/agweb_crop_comments.aspx

most of those folks could do with some of our rain and we could do with some of their sunshine.

M.T. Cranium

On Friday, Washington DC set a new all-time June record with 40 C (104 F) then got hit by a severe storm that has knocked out power to about half the region's population. Many trees came down throughout Ohio, West Virginia and Maryland, DC and northern Virginia. This was a "derecho" event, a complex of severe storms that raced east from Indiana (where it began around mid-day) and reached Chesapeake Bay around sunset. This storm complex has now totally vanished over the Atlantic but another weaker complex is firing up over Illinois and could try to perform a repeat.

The "super heat" is currently south of a line from about southern IL and IN across northern KY into NC, as today has turned out slightly cooler in VA and the northeast (but 35 C instead of 40-42 C). A further cooling takes place north of a second front that runs from south of Chicago through central Ohio to southern PA (more cloud north of this front is helping to keep temperatures comfortable) but the cloud dissipates east of the Poconos and so New York and Boston are quite hot today also (33-35 C).

Meanwhile, the 40-45 C temperatures continue in unbroken sunshine across the mid-South and southeast.

Blizzard 2010

Just back from New York. A real shock to the system. From 28 - 38 degrees over there to 13 degrees over here.

vickers209

Hi mt im heading to florida next week is there any chance of this drifting south towards orlando?? should i be concerned?


http://www.rte.ie/news/2012/0701/us-weather-storms.html

M.T. Cranium

Orlando would always be oppressively hot and humid in July and the range from record high to record low is fairly small. A record low temperature there would require something like a tropical storm to blot out the sun for an entire day and would still be 25-28 C. A record high would be 35-37 C. Normally it's about 30-34 C. So I wouldn't be concerned as long as you already knew how hot it was normally there. Expect it to be a bit warmer, but you're not going to be in the worst spot (Georgia is running 42-44 C).

eskimocat

Had never heard of the term Derecho before... did some reading (WIKI) and its an interesting one!

Its hard to imagine a sudden severe thunderstorm of that magnitude just materialising out of the blue, with damaging winds (gusts) exceeding 50kts, all travelling in a fairly direct line (well, actually a bow shaped line) We are so used to the comma type over here! and so used to seeing them dodging towards us (with jaws music running in the back ground).

Have we had a notable Derecho event? Perhaps we have had, but since these types of storms are a warm weather phenomenon I remain..

Tazio

I'm traveling to an area just west of Chicago next week for a few weeks with work. Kinda hoping to see a few spectacular thunderstorms.

One of my work colleagues forwarded this on:

http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=lot&storyid=84894&source=0

Kinda thought it made for interesting reading..

EDIT: I'll upload any picts/videos if it gets interesting..

Iancar29

Another good video

Extreme heat causes the road to buckle... a driver doesnt notice the signs..

https://www.youtube.com/watch?v=J8FaXdsg558

M.T. Cranium

Before I moved west in the summer of 1995, we had a very severe "derecho" in Ontario, it formed pretty much "out of the blue" on the night of 14-15 July 1995 near Georgian Bay and raced east to New England in about 12 hours.

Those were times when I was not doing much weather research and before the internet, so all I had to go on was the evening weather forecast on TV. That had absolutely no hint of a storm, and looking back on archived maps and imagery, there was very little to hint of a storm at all, just a few disorganized light showers around 9-10 p.m. north of Georgian Bay. The day just past had been oppressively hot (about 37 C) and sunny, very similar to last Friday in D.C.

Anyway, about 0230 our household were woken up by a continuous rumble of thunder and what quickly turned into almost non-stop lightning off to the west. Now unlike today, there was no place to boot up a radar, but I could see the thunderstorm tops in the lit-up clouds. About 0300h the storm hit and we had 80 mph winds and the continuous lightning and thunder. This was far worse than any "severe" storm I had seen in the past, even the back end of a tornado-producing storm in 1985 had been nowhere near this bad. Luckily there was no hail and the rainfall was not exceptional, although it was moving sideways.

Although ready to hit the basement, we were all watching this storm from an open door and welcoming the blasts of colder air as the house was not a/c and probably about 28 C after the heat. Large trees were bending at about a 45 degree angle and we lost a few branches but these trees were more battle-tested than the many trees that came down recently in D.C. and Maryland-Virginia. Further down the path, this derecho apparently did bring down a lot of trees and caused power failures, remarkably we never lost power although from 0300 to 0700 you wouldn't really need much anyway.

Found out the next day that an F-2 tornado had been embedded in the derecho (it wasn't called that until a few years later, I thought of it as a meso-scale convective cluster on steroids) and that did some significant structural damage to houses and a marina not far from our place, but after driving along the track I could see that it must have lifted after about 5 kms although you could spot a few trees down here and there all over the county the next day.

As to the question of a derecho style event in Ireland, I am not aware of any, the difference between a derecho and a strong cold front is normally this, you stay in hot air masses after it passes and the surface weather maps have very little pressure gradient, the storm actually is what I first called it, a meso-scale convective cluster on steroids. Those meso-scale events are more frequent in North America but if they fail to develop a long line-squall that travels a long way, they fail to reach "derecho" status even though some people will experience the same kind of weather. So those can also happen in Ireland and more frequently in southern England and northern France.

The phenomenon of continuous thunder and lightning is quite awe-inspiring, you might have seen a thunderstorm with frequent lightning and I was used to those living in a storm-prone region north of Toronto (lots of lake breeze convergence etc) but wasn't prepared for this continuous effect.

Pa ElGrande

https://www.youtube.com/watch?v=T5aUX5u82Lk

dirtyghettokid

M.T. Cranium wrote: »

Before I moved west in the summer of 1995, we had a very severe "derecho" in Ontario, it formed pretty much "out of the blue" on the night of 14-15 July 1995 near Georgian Bay and raced east to New England in about 12 hours.

jees i remember that storm. i was only a teenager at the time, and on summer hols from school, staying in oshawa ontario. it blew the big box fan out of the window beside me while i was sleeping. scared the absolute bejaysus out of me. looked out the window to see those plastic lawn chairs flying around... it was absolutely nuts. haven't seen too many storms like that!
the heat before that was unreal. we had no AC in the house so i was laying on a tiled floor with a fan on me all day. hideous!


i've been back in southern ontario since may -- here for the summer. i cannot hack the heat though. we have had multiple days where the humidex has gone over 40C. makes me physically ill! i'm waiting for some cracker thunderstorms.. but there hasn't been anything too crazy yet.
today is glorious... 25C, no humidex. hope it stays that way, but forecast says otherwise for the weekend. more heat on the way

nilhg

While the most extreme heat seems to have passed the drought in the US still keeps growing, projected crop yields are seen as being at least 20% lower and the price continues to increase almost every day.

http://www.agriculture.com/news/crops/extreme-drought-growing_2-ar25154?sssdmh=dm17.608748


Good news for me personally (as long as it dries up here) but some real hardship for farmers in the States and I can see food riots being a possibility in poorer countries in the not too distant future, remember it was the increase in food prices after the Russian drought a few years ago that sparked the Arab Spring.

Aiel

I read an article in the Irish Indo last Monday saying the heat has caused an increase in murders and aggresive behaviour in NYC,which relatively speaking is saying alot.It said last Monday that there had been 16 murders in the previous 5 days,thats twice the average and 1 City offical described the city as a "cauldron".

eskimocat

Aiel wrote: »

I read an article in the Irish Indo last Monday saying the heat has caused an increase in murders and aggresive behaviour in NYC,which relatively speaking is saying alot.It said last Monday that there had been 16 murders in the previous 5 days,thats twice the average and 1 City offical described the city as a "cauldron".

I remember reading years ago about why that happens, ie in extreme heat the incidents of burglary, car theft, bank robberies etc decreases (to hot to be running around dressed head to toe in black clothes with a balaclava on your head, me thinks ) but on the other hand the murder rate appears to increase as does incidents of domestic violence and road rage. It seems the heat reduces the barrier for violence to happen. That got me wondering why and then I found this

http://www.wired.com/wiredscience/2011/07/hot-weather-violence/

Interesting take on it.

M.T. Cranium

The road rage part is not surprising, not everyone has A/C in their vehicles and you can get pretty "steamed" in rush hour traffic when it's a hundred degrees (F) and you're baking on a freeway going 10 miles an hour. The domestic violence aspect also not surprising, beer sales go through the roof during heat waves (as I'm sure they would in Europe also). Mind you, the fertility rate also goes up (lots of March and April babies around).

dirtyghettokid

it's 35C in my backyard... i'm baking!!
the city i'm in, has issued a heat warning for sunday-wednesday.

only 1mm of rain has fallen in ottawa, ontario all month so far! way way down on avg rainfall amounts for july.

Tazio

Sitting in a meeting right now, around 30 mins west of Chicago (Naperville) and one of the most impressive thunder storms I've seen (and felt!) in a long time is taking place outside the window... no one cares. I'm tempted to take out my phone and take a video.. but people will think I'm crazy....

It was 32C at lunchtime... the humidity this morning was high too imo...


EDIT : here it is:

http://www.wunderground.com/radar/radblast.asp?ID=LOT&region=a4&lat=41.77991867&lon=-88.13723755&label=Naperville%2c%20IL

markfla

living in Phoenix Az and it's cooled down to 37C today, got caught in lightening on the golf course today too....we're normally used to mid 40's every day here this time of year. But we're better equipped with outside misters, people also know how to use AC properly here.

eskimocat

Tazio wrote: »

Sitting in a meeting right now, around 30 mins west of Chicago (Naperville) and one of the most impressive thunder storms I've seen (and felt!) in a long time is taking place outside the window... no one cares. I'm tempted to take out my phone and take a video.. but people will think I'm crazy....

Just tell them its for a bunch of mad people over in Ireland.... they'll understand that... sure we are all mad about the weather here!! lol

dirtyghettokid

today is most likely the hottest day of the year, here in southern ontario.

currently, at 3pm it's 34C with a humidex of 42C

see details of last 24hrs here including freaky dewpoint temps
http://text.weatheroffice.gc.ca/trends_table/pages/ypq_metric_e.html

and current conditions
http://www.theweathernetwork.com/weather/caon0536/

tornado warnings issued for eastern ontario. we have a severe thunderstorm watch, but haven't seen anything pop up on the radar yet. heat is supposed to break tonight with the passing of a cold front. PLEASE GOD let it cool. sick of these desperate hot temps

Elmer Blooker

I experienced 40.3c in Malaga last Sat the 14th, I know the temp got that high cos it made the front page of the local paper the next day. It was certainly the highest temperature I've ever experienced and I have to say it was very unpleasant - thank god for aircon !!

Tazio

Well it approx 35C here today in Naperville, Lisle and all poised for thunderstorms later (40% chance).. I just need one good one and the camera phone out at the same time...


EDIT: heading back home in the next day or two so last chance here for sparks...