1936 - Hottest temperature ever at OKC

[Tim Vasquez]

With temperatures reaching 102-103 at Norman and OKC today, I figured it's worth checking out the hottest day on record for that area.

On August 11, 1936, Oklahoma City officially reached 113 degrees, which remains its all-time highest temperature.

Here is the analysis that morning:

http://www.weathergraphics.com/tim/1936a.jpg

I marked some interesting features on this map in color. One of them is a back-door front across northeast Oklahoma from an unseasonably strong Great Lakes high. Don't let it fool you, though. Highs across Indiana and Ohio were still around 90.

I also drew in two subsynoptic lows along that front; one on the KS-OK border and one near Dallas. Presumably both of them strengthened baroclinically and were able to feed enough downslope air across OK and NW TX to raise temperatures even higher than they would have otherwise.

After the day was done, here's the numbers.

http://www.weathergraphics.com/tim/1936b.jpg

The 114 reading differs from the 113 listed on the NWS OUN climatology; I'm not sure why that is but it's still the hottest on record. I can't begin to imagine that overnight low of 82 in an era where air conditioning wasn't all that widespread.

EDIT: The second hottest day at OKC was July 6, 1996 when the airport saw 110. Here is the surface map, and it's very interesting that this shows almost the same configuration of fronts and lows. Interestingly the Great Lakes highs in 1996 strengthened spectacularly by August, and Kansas City was seeing 60s for afternoon highs if I remember correctly, and OKC temperatures were running 10-20 degrees below normal.

http://www.weathergraphics.com/tim/1936c.jpg


Tim

[Darrin Rasberry]

Probably moist as Houston all the way up there, too. It's a wonder the surface winds weren't strong, but I guess lows down there in August don't deepen like those in spring given that the jet would've probably been over Santa's house at that time of the year.

Dunno how dry the above-ground intrusions are during late summer over OKC, but if they happen even just a bit there the CAPE on that day probably would have been ridonkulous.

What's a subsynopic low, another name for mesolow? And is the low on the bottom diagram full scale synoptic? What would be the difference between sizes of the "closure" and ability to advect temperature?

[Tim Vasquez]

Honestly I don't think I've ever seen a definition for "subsynoptic low" laid out anywhere, so there's probably some ambiguity about how much of the mesoscale range it covers and it may not be the best term to use. It almost certainly covers the upper ranges, though (meso-alpha), and that's the way I generally use it. I may have to quit using it though if there's no definition.

This daily weather map series is a synoptic-scale presentation but close scrutiny of the data does bring out some mesoscale structure.

The ability to advect temperature is probably more dependent on the pressure gradient and over how wide an area than whether a closed low is found. When dealing with weak lows, closure is kind of a yes/no thing and is sensitive to data density, so I'd be hesitant to draw conclusions from that alone.

Tim