July 2019 General Discussion

[cyclone77]

3 hours ago, Hoosier said:

I am curious if an actual 100 degree streak will materialize and not just a one off.  Just thinking back on past 100 degree streaks for Chicago, I am having a hard time remembering one happening when there's not a drought.  It has dried out recently but not a prolonged thing going back months.  Not saying it couldn't happen but being in a drought certainly would make it easier.  

Yeah it will be interesting to see how this progresses.  It has really dried out here over the past 2 weeks.  After having an ultra lush and very fast growing lawn all season, it has really charred up the past week or so with the heat/lack of precip.  Overall lack of drought conditions may temper the heat potential, but one thing to consider is that the corn and soybeans are considerably less further along than normal.  

BTW, looks like mother nature is trying to cheer you up some.  Looks like a pretty potent storm went through your area earlier this eve.

[Jim Martin]

Just now, snowlover2 said:

Still the one from yesterday. Seems odd they didn't update it today.

Ah.

[cyclone77]

3 minutes ago, snowlover2 said:

Still the one from yesterday. Seems odd they didn't update it today.

They just updated it.  They skipped the map graphic and just included this.

[Jackstraw]

Its been even worse around here.  Still barely over .25 in's over the last 3 weeks and we missed out on some of the larger totals a few weeks before that with a 5 week total of around 1.25.  Latest Barry forecasts aren't showing as much relief around here as they we're 24 hr's ago. The exposed ground on my property resembles a western dry lake bed.  At least no 100's forecast for the near future but day/night low to mid 90's/mid upper 70's with dews running low to mid 70's across the board aren't going to be too pleasant.  August coming early maybe October will too lol.  

[IWXwx]

4 hours ago, Jackstraw said:

Its been even worse around here.  Still barely over .25 in's over the last 3 weeks and we missed out on some of the larger totals a few weeks before that with a 5 week total of around 1.25.  Latest Barry forecasts aren't showing as much relief around here as they we're 24 hr's ago. The exposed ground on my property resembles a western dry lake bed.  At least no 100's forecast for the near future but day/night low to mid 90's/mid upper 70's with dews running low to mid 70's across the board aren't going to be too pleasant.  August coming early maybe October will too lol.  

It was beginning to get dry up here too, although we've had much more rain in the past couple of weeks than you. We got dumped on last night.

The radar under estimated how much fell in this area. How much IMBY? Think pi. Lets play guess where the boundary was:

 

[Hoosier]

GFS flipped a little for Saturday over the past 3 runs

[cyclone77]

Back in 1936 on this date MLI hit 111.  Even Dubuque hit 110.  Makes today's lower 90s seem pretty frosty.

Some cu building up overhead.  Could get a downpour later according to various runs of hi-res models.

[Hoosier]

I am buying into the idea of at least 1 day of 100 at ORD late week/weekend.  Thursday gets pretty warm aloft but with it being sort of the transition day of the really hot airmass coming in, I could see it falling short.  Friday looks like a bit better shot to me at this time... it should still be quite warm aloft and the starting point on Friday morning should be very warm (80 ish).  Not really going to focus too much on Sat/Sun yet.

[Jackstraw]

7 hours ago, IWXwx said:

It was beginning to get dry up here too, although we've had much more rain in the past couple of weeks than you. We got dumped on last night.

The radar under estimated how much fell in this area. How much IMBY? Think pi. Lets play guess where the boundary was:

 

A little more hope here today with s bit of a CU field building but still looks like the boundary is still just N.  

[Jim Martin]

[NegativeEPO]

6 hours ago, Hoosier said:

GFS flipped a little for Saturday over the past 3 runs

Such a trash model.

[Chicago Storm]

On 7/12/2019 at 3:08 PM, NegativeEPO said:

Strange. I remember a few years back ORD was a warm spot in the area. Now it seems to lag behind other reporting sites. Even on days with lake breezes, it’s barely warmer than PWK... sometimes not any warmer at all despite PWK being closer to the lake. Now DPA seems to be a warm spot which was never the case in the past.

Yea, in 2012 ORD actually lead the pack many times. However, a few years ago the location of the OBS site was moved on the property. Additionally, they have finished some nearby construction, while starting other new nearby construction. Those changes are likely playing a role as well...

[Chicago Storm]

94 at ORD and MDW yesterday, and 95 here.

91 at ORD, 90 MDW and 94 here today.

MBY, and the western suburbs in general, have been consistently warmer that the immediate UHI the past month or so. Some days the lake has played a role, such as today, and other days not so much.

[IWXwx]

5 hours ago, Jackstraw said:

A little more hope here today with s bit of a CU field building but still looks like the boundary is still just N.  

It looks like you got hit late this afternoon/evening. The rains trained along the boundary just south of me this evening.

[bowtie`]

1 hour ago, IWXwx said:

It looks like you got hit late this afternoon/evening. The rains trained along the boundary just south of me this evening.

Did not make it this far south (Lebanon).

[Jackstraw]

2 hours ago, IWXwx said:

It looks like you got hit late this afternoon/evening. The rains trained along the boundary just south of me this evening.

Yep got nailed finally.  Almost .6 in my gauge.  I swear I could see daylight the whole time just off to my SE so really were on the edge.  Just N of me really got hammered with some rain.

[michsnowfreak]

15 hours ago, Chicago Storm said:

Yea, in 2012 ORD actually lead the pack many times. However, a few years ago the location of the OBS site was moved on the property. Additionally, they have finished some nearby construction, while starting other new nearby construction. Those changes are likely playing a role as well...

DTW is consistently among the warmest temps in the area, and it did not used to be. Used to be one of the better radiators. Its not that theres anything wrong with the sensors, but i think changes in nearby environments, pavements, construction, etc play a part.

[Hoosier]

With Chicago looking to at least get close to 100 if not make it later this week and weekend, here are some stats.  

Officially, Chicago has reached 100+ a total of 65 times, with the last occurrence on July 6, 2012.  On average, that is almost 1 day every 2 years, but it is a bit misleading.  The 65 days of 100+ have occurred in just 33 years, suggesting that it is not all that rare to get multiple such days in a year when it does happen.  Several year gaps between 100 degree days are not uncommon.

43 out of 65 days have been 100 or 101, so roughly 2/3 of the time.  It is much more unusual to get to 103+

To weave some cold talk into this and throw beavis a bone... the largest spread in temperatures in the same year is 126 degrees, which happened in 1985 (-27 for lowest temp, 99 for highest temp).  Chicago reached -23 at the end of January, so in order to achieve a 126 degree spread, Chicago would have to hit 103.  Might be tough to do but may at least get kind of close.

[beavis1729]

1 hour ago, Hoosier said:

With Chicago looking to at least get close to 100 if not make it later this week and weekend, here are some stats.  

Officially, Chicago has reached 100+ a total of 65 times, with the last occurrence on July 6, 2012.  On average, that is almost 1 day every 2 years, but it is a bit misleading.  The 65 days of 100+ have occurred in just 33 years, suggesting that it is not all that rare to get multiple such days in a year when it does happen.  Several year gaps between 100 degree days are not uncommon.

43 out of 65 days have been 100 or 101, so roughly 2/3 of the time.  It is much more unusual to get to 103+

To weave some cold talk into this and throw beavis a bone... the largest spread in temperatures in the same year is 126 degrees, which happened in 1985 (-27 for lowest temp, 99 for highest temp).  Chicago reached -23 at the end of January, so in order to achieve a 126 degree spread, Chicago would have to hit 103.  Might be tough to do but may at least get kind of close.

Nice stats. 

As it looks now, Friday will remain capped/sunny, with a high launching point in the AM (overnight min near 80F).  Lack of afternoon mixing is always a risk, but would be mitigated somewhat due to the high overnight min and relatively dry ground.  With this in mind, here are my thoughts for ORD:

98F or higher:  80%

100F or higher:  40%

102F or higher:  5%

Daily records for 7/19 are:

- Max = 101F, set in 1930

- Warmest min = 78F, set in 2011

[Hoosier]

1 hour ago, beavis1729 said:

Nice stats. 

As it looks now, Friday will remain capped/sunny, with a high launching point in the AM (overnight min near 80F).  Lack of afternoon mixing is always a risk, but would be mitigated somewhat due to the high overnight min and relatively dry ground.  With this in mind, here are my thoughts for ORD:

98F or higher:  80%

100F or higher:  40%

102F or higher:  5%

Daily records for 7/19 are:

- Max = 101F, set in 1930

- Warmest min = 78F, set in 2011

Another thing to watch... can the rare 100/80 day be pulled off?  Not temp/dewpoint, but high/low.  There have only been 8 days with a high of 100+ and a low of 80+ on the same day, with the most recent occurrence for that being July 6, 2012 (hi 103, low 82).  7 out of the 8 occurrences have been in July, so this would be the time for it.

[beavis1729]

22 minutes ago, Hoosier said:

Another thing to watch... can the rare 100/80 day be pulled off?  Not temp/dewpoint, but high/low.  There have only been 8 days with a high of 100+ and a low of 80+ on the same day, with the most recent occurrence for that being July 6, 2012 (hi 103, low 82).  7 out of the 8 occurrences have been in July, so this would be the time for it.

Yeah, could be close.

Excessive Heat Watch for the entire state of Iowa.  DVN's Excessive Heat Warning criteria is 2 consecutive days with HI 105+, or 4 consecutive days with HI 100+.

From DVN:

313 PM CDT Mon Jul 15 2019

...EXCESSIVE HEAT WATCH IN EFFECT FROM WEDNESDAY AFTERNOON
THROUGH SATURDAY EVENING...

The National Weather Service in Quad Cities has issued an
Excessive Heat Watch, which is in effect from Wednesday afternoon
through Saturday evening.

* Heat Index Values...Ranging from 100 to 110 due to temperatures
  in the mid to upper 90s...and dewpoints in the low to mid 70s.

* Timing...Wednesday Afternoon through Saturday Evening.

* Impacts...Heat-related illnesses may occur due to the prolonged
  period of heat and humidity.

  

[Chicago Storm]

92 at ORD, MDW and here today.


.

[Jackstraw]

Luckily it takes a lot for this area to hit 100 compared to points west.  Not quite sure why but when the heats on we tend to run 5 or so degrees cooler around here.  Not like it makes that much difference if dews are in the 70's and lows in the mid 70's.  I'd still like to wait for the dog days for this stuff to start.

[Hoosier]

40 minutes ago, Jackstraw said:

Luckily it takes a lot for this area to hit 100 compared to points west.  Not quite sure why but when the heats on we tend to run 5 or so degrees cooler around here.  Not like it makes that much difference if dews are in the 70's and lows in the mid 70's.  I'd still like to wait for the dog days for this stuff to start.

Yeah it's interesting.  I think being a bit farther away from the source region of these airmasses plays a role.  

This upcoming heatwave doesn't really strike me as one of those where everybody between Moline and Chicago is going to reach 100.  I think it's a bit too marginal.  The UHI around Chicago could give enough of a boost to reach triple digits.  

[bowtie`]

1 hour ago, Jackstraw said:

Luckily it takes a lot for this area to hit 100 compared to points west.  Not quite sure why but when the heats on we tend to run 5 or so degrees cooler around here.  Not like it makes that much difference if dews are in the 70's and lows in the mid 70's.  I'd still like to wait for the dog days for this stuff to start.

Lake influence?

[Hoosier]

35 minutes ago, bowtie` said:

Lake influence?

I don't think that works for central IN.  The hottest days are going to tend to have west or southwest flow, and there are no large lakes in those directions.

[Jackstraw]

I've often thought that points W are less influenced by flow off the gulf and more from "heat island" areas like west TX, NM and AZ.  Our big heat does tend to come from the W/SW but geographically it may actually be a bit more moderated by the gulf than points west where the flow spends more time over dry hot arid areas.  So guess could say it is lake enhanced by the gulf lol.     

[nwohweather]

Looks like Friday-Sunday we will be making a run at 100° here in Columbus. Definitely gonna be a pool/Zoombezi Bay day here. I think the dews may hold it back a bit but definitely a chance

[beavis1729]

Nice overnight AFD from Carlaw at LOT.  Very technical and interesting.  Mentioned a term that I've never heard before:  Wet Bulb Globe Temperature (WBGT), a measure of heat stress in direct sunlgiht which takes into account sun angle, cloud cover, and wind speed.

Depending on what happens with any convective complex Thursday
morning, outflow may temporarily bring lower dewpoints and
temperatures to the area to start the day. However, southwesterly
low-level flow will transport renewed moisture into the region
through the day. Rising mid-level heights and 850 mb temperatures
warming towards +25C will set the stage for oppressive heat and
humidity on Thursday afternoon. Some questions remain regarding the
degree of mixing during the afternoon with breezy southwesterly
winds (gusting to 25-30 mph at times), although the aforementioned
cap may limit the propensity for dewpoints to quickly mix out. If
this occurs, heat indices would likely rise into the 104-110 degree
range across a large portion of the CWA (including the lakeshore).
The breezy southwest winds will help take the edge of the heat and
humidity a bit, however. The Wet Bulb Globe Temperature, which is a
measure of heat stress (in direct sunlight) and takes into account
sun angle, cloud cover, and wind speeds maxes out in the 86-89
degree range on Thursday with our current forecast. While these
values are certainly at the higher end of the spectrum, WBGT
values are actually higher (89-92) on Friday when wind speeds
decrease, even though heat indices may actually be a degree or two
lower than on Thursday. Values above 89 indicate exceptionally
high heat stress potential.

The heat and humidity look to persist into Saturday, although there
are still some questions regarding MCSs which may start to get close
to us. Associated cooling outflows throw a wrench into this portion
of the forecast. Given the lingering uncertainties (regarding mixing
potential on Thursday and the longevity of the hottest conditions),
we will not be hoisting any heat headlines at this time. A
combination of Heat Advisories and Excessive Heat Watches/Warnings
will likely be needed in future forecasts, however. It`s also worth
noting here that little relief from the heat will occur at night,
with sweltering conditions expected Thursday and Friday nights with
near or record high minimum temperatures forecast.

[Hoosier]

3 hours ago, beavis1729 said:

Nice overnight AFD from Carlaw at LOT.  Very technical and interesting.  Mentioned a term that I've never heard before:  Wet Bulb Globe Temperature (WBGT), a measure of heat stress in direct sunlgiht which takes into account sun angle, cloud cover, and wind speed.

Depending on what happens with any convective complex Thursday
morning, outflow may temporarily bring lower dewpoints and
temperatures to the area to start the day. However, southwesterly
low-level flow will transport renewed moisture into the region
through the day. Rising mid-level heights and 850 mb temperatures
warming towards +25C will set the stage for oppressive heat and
humidity on Thursday afternoon. Some questions remain regarding the
degree of mixing during the afternoon with breezy southwesterly
winds (gusting to 25-30 mph at times), although the aforementioned
cap may limit the propensity for dewpoints to quickly mix out. If
this occurs, heat indices would likely rise into the 104-110 degree
range across a large portion of the CWA (including the lakeshore).
The breezy southwest winds will help take the edge of the heat and
humidity a bit, however. The Wet Bulb Globe Temperature, which is a
measure of heat stress (in direct sunlight) and takes into account
sun angle, cloud cover, and wind speeds maxes out in the 86-89
degree range on Thursday with our current forecast. While these
values are certainly at the higher end of the spectrum, WBGT
values are actually higher (89-92) on Friday when wind speeds
decrease, even though heat indices may actually be a degree or two
lower than on Thursday. Values above 89 indicate exceptionally
high heat stress potential.

The heat and humidity look to persist into Saturday, although there
are still some questions regarding MCSs which may start to get close
to us. Associated cooling outflows throw a wrench into this portion
of the forecast. Given the lingering uncertainties (regarding mixing
potential on Thursday and the longevity of the hottest conditions),
we will not be hoisting any heat headlines at this time. A
combination of Heat Advisories and Excessive Heat Watches/Warnings
will likely be needed in future forecasts, however. It`s also worth
noting here that little relief from the heat will occur at night,
with sweltering conditions expected Thursday and Friday nights with
near or record high minimum temperatures forecast.

Never heard that term either.  I like this Carlaw person.  They usually have pretty decent afds.  

98/79 in the forecast for ORD on Friday.  Getting close to the magic numbers.