michsnowfreak Posted July 18, 2013 Share Posted July 18, 2013 Sometimes the extreme 100F situations in the Midwest and Great Lakes have more of a dry airmass that develops in the south central (or even the desert) that moves to the Midwest, with drought-type soil moisture, like last year. Right now, we have a high-moisture, high-PW airmass that developed on top of us, along with medium or high soil moisture.True about the most extreme heatwaves, but again...this one isn't close to being extreme from a temp standpoint. Link to comment Share on other sites More sharing options...
Stebo Posted July 18, 2013 Share Posted July 18, 2013 True about the most extreme heatwaves, but again...this one isn't close to being extreme from a temp standpoint. It would be, if we didn't have over 8" of rain since June, that being said the heat index has been around 100 daily for the last 4 days. It is not extreme but it isn't exactly a nothing heatwave. Link to comment Share on other sites More sharing options...
Trent Posted July 18, 2013 Share Posted July 18, 2013 True about the most extreme heatwaves, but again...this one isn't close to being extreme from a temp standpoint. I think you have to look at it from an overall temp standpoint. The hottest days tend to be drier airmasses and hence the overnight lows are much cooler. The moist airmasses have lower highs but much warmer overnight lows. A 98/68 day is colder than the 90/77 recorded earlier this week at DTW. The string of lows at DTW and other Midwestern locales is definitely impressive this week. When was the last time DTW had 4 straight nights with lows at or above 75? That in itself is mighty noteworthy. In fact that might actually be a record for Detroit. Link to comment Share on other sites More sharing options...
SpartyOn Posted July 18, 2013 Share Posted July 18, 2013 I don't even fully understand this thickness stuff in the summer lol...but I do know that from a sensible weather aspect (as unbearable as it is) this heatwave is NOTHING. Why are the temps not more impressive if the 600dm heights are so epic? Nothing? Joking or soft trolling? We are under an excessive heat warning. Not too mention Im sure you too burst into a instant sweat when getting in and out of your car. The humidity and heat indexs have been solid in this event. Last years dry 100s felt more tolerable than this stuff. Link to comment Share on other sites More sharing options...
Torchageddon Posted July 18, 2013 Share Posted July 18, 2013 I would definitely not call it a nothing heatwave, at least not at my location. I'm actually impressed with this one, it was a long one unlike a lot of them for southern Ontario (3 days normally, this is going on 6). It started Saturday at near 90F and then continued above that reaching 94F or close to it 3-4 days in a row. Decent humidex readings falling short of the Great 2011 heatwave. For Bruce-Grey counties closer to the lake, reaching official heatwave status is somewhat difficult and we easily did it this time. The 600 dm heights were more of a result of an unusually deeply warm airmass. During the peak height period, freezing levels were really high (like 17-18k feet) and the 500-600 mb layer was quite warm. Deeply warm doesn't always equate to blowtorch/record warmth, and 850 mb temps were not terribly impressive. Here I was wishing for the 600 dm stuff not far away and it came knocking on my door this week. I wasn't checking the 500 mb or 850 mb maps during most of this event so I was a tad surprised to see a semi-death ridge so close by. Despite the temperatures Ontario and Quebec got, the type of profiles at the mid-levels should have givin something way higher like near 100F for southern Ontario but just 93-94F for the most part. I don't understand this as this occurred during the moist July 21, 2011 day. I obviously know that the 500 mb layer isn't everything for heat but similar conditions were present this time but no records. I thought 500 mb influenced the 850 mb temps the most? Sometimes the extreme 100F situations in the Midwest and Great Lakes have more of a dry airmass that develops in the south central (or even the desert) that moves to the Midwest, with drought-type soil moisture, like last year. Right now, we have a high-moisture, high-PW airmass that developed on top of us, along with medium or high soil moisture. I know its been quite wet and a drier heat bumps the temp up, but what was the main difference between July 21, 2011 and this heatwave? 2011 was high moisture, maybe those last two factors you mentioned kept the high temp. down a bit? Link to comment Share on other sites More sharing options...
michsnowfreak Posted July 20, 2013 Share Posted July 20, 2013 Nothing? Joking or soft trolling? We are under an excessive heat warning. Not too mention Im sure you too burst into a instant sweat when getting in and out of your car. The humidity and heat indexs have been solid in this event. Last years dry 100s felt more tolerable than this stuff. LOL no I'll leave the trolling to you. I hate this weather. My glasses fogged up when I got out of the car. Has nothing to do with my comment. I meant "nothing" in terms of historical perspective of actual temps compared to the epic heights. This was a 5-day heatwave with high temps ranging from 90-95. This probably ranks as, what, the 50th or 60th worst heatwave on record? Yet with epic or historic 500mb heights? The explanations in this thread of why this was make perfect sense. I just meant the actual temps and more importantly longevity of this heatwave wouldn't cause a second glance to someone looking up the worst heatwaves on record, but to someone looking for 600dm height records it would certainly stick out. It would be like watching 850mb temps of -40C produce a low of 5F in Minneapolis. Link to comment Share on other sites More sharing options...
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