beavis1729

Interesting...I have seen comments in other sub forums suggesting that a weak and/or Modoki El Niño may be on the way...which would generally be good for our area. I guess it all just shows that it’s still a bit early to speculate. But we should have a much better idea in 3-4 weeks.

Good point about the corn...and even in Chicago metro, the prevailing W or SW winds may advect some of the higher-Td air from the cornfields into the area. There is something unsettling about humans altering their environment so much, that it impacts local & regional climo so significantly...

I've been thinking how rare it has been over the last few "summers" (which I define as June 10th - Sep 10th at ORD due to the colder lake temps in early June) to have comfortable mornings...or even "normal" mornings. So far in 2018, about 70% of days in this time period have had above-normal low temps at ORD...and it's probably similar for 2016 and 2017. Some of this is UHI...but warmer mornings during this 3-month "summer" period seem to be occurring over all of the Chicago metro, not just ORD. In July, the normal low is around 65...so you'd generally expect the same # of days with lows of 70+ vs. lows in the 50s. But here are the numbers... July 2016: 10 days with lows of 70+, 4 days with lows in the 50s July 2017: 7 days with lows of 70+, 1 day with lows in the 50s July 2018: 10 days with lows of 70+, 1 day with lows in the 50s July 2016-2018 Total: 27 days with lows of 70+, 6 days with lows in the 50s I hope this isn't a "new normal". In summers past, I remember many instances when a cool Canadian high would come down, with dry dewpoints and highs in the 70s and lows in the 50s...even during the peak of summer. It seems like we rarely get these days anymore. Is it because the arctic/Canada is generally warming...and therefore the source region for these air masses is warmer? Or, is it simply UHI in all of Chicago metro, not just ORD?

And the INL hourly obs were interesting...it was 56/49 at 9 PM last night...then 35/35 at 6 AM this morning...then up to 50/50 three hours later. Is that indicative of extreme radiational cooling...where both the temp and Td dropped significantly for a brief period of time, then recovered? You don't see that too often, especially this time of year.

^ That's some insane UHI at ORD. What could be causing that - the recent change in location of the ob site?

July 2018 will end as the warmest July on record in Key West FL, with a mean temp of 86.9F. Even so, it's only a +2.3F departure from the 1981-2010 normal. On July 26th, the max/min was 93/86...yuck. The only hotter month was August 2007, with a mean temp of 87.5F.

Not sure if this is the appropriate thread...but the dewpoint at Barrow (Utqiagvik) AK hit 58 yesterday. That is shocking to me...at 71.3N, right on the Arctic Ocean.

The core of the heat isn't even over TX yet...and Dallas (Love Field) is currently 107/61/109. Assuming no remnant clouds from potential storms to the north tomorrow and Friday, you'd have to think 109-110 is possible.

Las Vegas actually had a dewpoint of 74 yesterday. I wonder if that's a new record? I didn't think such high Td's were possible in that part of the world. I know the monsoon visits the area in July-August, but my understanding is that the greatest impacts are typically further east than Las Vegas.

Hope you're enjoying your time there. What part of Iceland?

After the incredible humidity over the past week, ORD was 80/32 at 1:00 PM local time today, for an RH of 17%. Haven't seen an RH level that low in Chicago for awhile...and honestly I can't remember ever seeing a dewpoint as low as 32 in July before. Of course the Td’s at ORD seem to be running low recently. Has NWS LOT opened an official inquiry into this? Either way...a brief oasis of intense dryness in a sea of unbearable humidity...and one extreme to the other....kind of sums up 2018 so far.

Yes (Olney IL, I believe)...and I even saw an 83 yesterday over the corn fields south of Chicago.

These CA and AZ numbers are air temps. Because it's so dry there, the heat index is typically much lower than the air temp. I also removed the 100F for Fort Yukon AK, for the same reason. I'll add AR to the list. I'm sure they have had a heat index > 120, but we'll use that for now.

http://ak-wx.blogspot.com/2018/07/possible-el-ni-modoki.html Those Modoki analogs would be great for the Midwest...especially 1977-78 and 2014-15.

Thank you sir. On 8/2/1975, peak HI appears to be 114 at 3PM local (temp 103, Td 72). This far exceeds 7/22/2011. I'll go with this for the ME record for now.

Very good point. I could see valid Td's near 85, such as what has occurred over the past few days in or near Pontiac, IL (which appears to be taken as valid data by NWS Chicago). However, 90 may be a stretch, unless the instrument is literally located in the corn field. And if this is really true, I guess it would be valid although not very "representative"...kind of like the DCA ob site being in an extreme urban environment. Either way, it may be useful to look up some other WI stations on 7/13/1995 to see how high the HI's were...or potentially use the Appleton temp of 101 with a Td of 85 instead of 90??

Good catch on ND. I updated the list (and OH too, per the other post). Christmas Eve 1983 must have been a great night for the good folks of Williston to sit in front of the fireplace and enjoy the holiday spirit. Those are some good old-fashioned winter conditions...wow.

**Updated several times as new info becomes available WI: 149 (Appleton, 7/13/1995) IA: 131 (Knoxville, 7/18/2011) IL: 125 (Midway Airport, 7/13/1995) OK: 125 (Calvin, 7/9/1999) SC: 124 (Mount Pleasant, 7/13/2011) KS: 121 (Topeka, 7/22/2017) AR: 120 (Adams, 8/3/2011) ME: 114 (Portland, 8/2/1975) NY: 113 (Fairport, 7/2/2018)

Not in our area...but for posterity, here is the Burlington VT forecast discussion. Max/min in BTV yesterday was 96/76, and the low temp this morning was 81. It may be close to 100 today...and we'll have to see if the low temp of 81 holds before midnight. Normals for today are 80/59. Area Forecast Discussion National Weather Service Burlington VT 1030 AM EDT Mon Jul 2 2018 .SYNOPSIS... Historically significant heat wave continues today with near record to record high temperatures in the mid to upper 90s. Oppressive humidity will continue today as well, with heat index values peaking between 100 and 110 degrees in most valley locations. A weak mid-level trough will shift eastward across northern New York this evening, bringing isolated to scattered thunderstorms to portions of northern New York and Vermont. A few strong storms are possible with brief heavy rainfall and localized strong wind gusts. Behind the trough, high temperatures will remain in the upper 80s to lower 90s for Tuesday and Independence Day, but humidity levels will be a bit more moderate. A cold front arriving Thursday night and Friday will bring widespread showers and thunderstorms, followed by long sought relief from the 90 plus degree temperatures on Friday and Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 1030 AM EDT Monday...Morning to early afternoon forecast remains on track with just a slight tweak needed to sky cover to account for some cumulus popping up across the northern Adirondacks. BTV is already 90F, indications of just how hot it`s going to be today. Will we hit 100? Time will tell. Previous Discussion...Rather incredible early morning underway with temperatures steady at 85F at BTV and a 73F dewpoint. The south wind around 10 mph feels like a misplaced trade wind from the tropics, a surreal VT wx experience. The south winds and scattered clouds in the Champlain Valley should hold early morning temps 80+, before soaring back to the mid- upr 90s areawide this afternoon. Today should be the hottest day of this historic heat wave, with near record to record high temperatures expected once again. Dewpoints will remain near 70F, resulting in continued oppressive humidity levels. With the forecast on track, no changes to ongoing Excessive Heat Warnings and Heat Advisories valid thru this evening. Winds will increase from the south with PBL heating/mixing, reaching 10-15 mph this afternoon with a few gusts near 20 mph. It continues to appear that 700-500mb vorticity filament will shift ewd into the northern Adirondacks around 00Z Tuesday, along with weak sfc trough. Should be just enough forcing to initiate convective storms late aftn/early evening across nrn NY, with isolated scattered thunderstorms tracking ewd across the Champlain Valley and nrn VT 23-04Z time frame. With PW values near 2", included mention of heavy rainfall with any thunderstorm activity. May also see a damaging downburst or two...the SPC has portions of the forecast area in a marginal risk of severe t-storms for this possibility later today, per 06Z Day 1 Outlook. Rain cooled outflow may well force temperatures into the mid 70s at BTV before midnight...we`ll watch how that evolves for climate purposes (all-time record high-low is 78F at BTV, possible pending convective evolution). Precip threat moves east and wanes overnight. May see some patchy BR/FG late, especially in spots seeing tstm activity earlier in the evening. Overnight lows generally in the low-mid 70s.

Yeah, I was 9 years old for the December 1983 arctic outbreak, living in the Chicago suburbs. It’s my first weather memory.

Based on the article below from the IL State Climatologist, 121F is a very conservative starting point for the Illinois heat index record (Peoria on 7/13/1995). However, I would actually go with 125F at Midway Airport on that same date...even though Midway is not an official repoting station. I have to imagine many places in IL near corn fields have come close to or exceeded 125F on occasion...and in fact aren't too far off from that number with today's heat. https://climateillinois.wordpress.com/2011/07/19/heat-index-extremes-for-illinois/

Good catch...the -52 seems legitimate. I updated the list (1st post of the thread). Same with your comments upthread for HI, OR, WA, MA.

Nice. That is an insane airmass...-23 in Akron OH with a 21 mph wind out of the SW. Wow...

Very rarely in that part of the world. In fact, they hardly ever occur even in the Chicago area...where winter temps average about 6-8 degrees colder than northern KS. As an example...despite the fact that 1/6/2014 was a brutally cold and windy day in northern IL, wind chills "only" dropped to around -45.

Good find. In those hourlies, I see -21 with 16 mph wind, and -22 with 14 mph wind. Both result in a WC of -47. The intra-hour reading showed a 16 mph wind, but no temp to go along with it. Again, can't take it too seriously; part of the challenge and fun of science is putting the pieces together and finding/analyzing data. The planet has been around for a long time...I'm sure some of records will be broken in the next 50-100 years. Some of it depends on timing and having a better observation network now; we don't need to hope that the extreme events occur only at the major reporting stations. For example - if the record cold in Bartlesville, OK in Feb 2011 occurred a generation ago, we would have probably never known about it. Same with tropical storms in the middle of the Atlantic. Just part of the journey. I've updated the list in the first post of the thread; it's easier to keep track there.