September 2023 General Discussion

[Spartman]

[TheClimateChanger]

Although outside this subforum, worth noting Denver reached 99 today. I checked on NowData, and that was a daily record and equals the third warmest reading on record in the month of September.

The only warmer readings were 100 on September 2, 2019, and 101 on September 5, 2020. It also reached 99 on September 7 & 8, 2022, and September 10, 2021.

Prior to 2019, it had never reached 98 in Denver in the month of September. With today’s high of 99, it has now reached 98 or better on nine occasions in the past 5 years.

In the context of the past five years, a pretty typical early September heat wave in Denver. But it would have been a new monthly record high prior to 2019. Records for Denver date to 1872.

[Castaway]

14 hours ago, TheClimateChanger said:

Although outside this subforum, worth noting Denver reached 99 today. I checked on NowData, and that was a daily record and equals the third warmest reading on record in the month of September.

The only warmer readings were 100 on September 2, 2019, and 101 on September 5, 2020. It also reached 99 on September 7 & 8, 2022, and September 10, 2021.

Prior to 2019, it had never reached 98 in Denver in the month of September. With today’s high of 99, it has now reached 98 or better on nine occasions in the past 5 years.

In the context of the past five years, a pretty typical early September heat wave in Denver. But it would have been a new monthly record high prior to 2019. Records for Denver date to 1872.

Denver got 99’d yesterday? Just 1 French fry away from a 100.

ruff.

[TheClimateChanger]

Impressive heat in parts of South Dakota today. Winner reached 107F, one shy of the all-time record for the month of September set on September 9, 1931, and the second warmest reading on record for the month. The low of 76F was also the second warmest of record, behind 78F on September 7, 1945. The daily mean of 91.5F was easily the hottest of record in the month of September. The old record was 89.0F, set on September 2, 1983 & September 8, 1931.

In fact, the 91.5F daily mean is the easily the latest in the calendar year that value was attained. A daily mean of 91.5F was reached on August 16, 1988, which is the latest date other than today on which a daily mean equal to or greater than today’s value was attained at Winner, SD.

[Spartman]

Got 89'd on the first Saturday night of September. It's the highest it's going to get for the month. Almost all the 90s are dropped from the upcoming week.

Today
Sunny, with a high near 89. West wind 5 to 10 mph.
Tonight
Mostly clear, with a low around 67. Southwest wind 5 to 7 mph.
Labor Day
Sunny, with a high near 90. Calm wind becoming southwest 5 to 9 mph in the morning.
Monday Night
Partly cloudy, with a low around 70. Southwest wind around 6 mph becoming calm after midnight.
Tuesday
Mostly sunny, with a high near 89. Light south wind becoming southwest 5 to 9 mph in the morning.
Tuesday Night
Mostly cloudy, with a low around 69.
Wednesday
Mostly sunny, with a high near 87.
Wednesday Night
A chance of showers between 8pm and 2am. Partly cloudy, with a low around 68. Chance of precipitation is 30%.
Thursday
A chance of showers after 2pm. Mostly sunny, with a high near 83. Chance of precipitation is 30%.
Thursday Night
A chance of showers before 8pm. Partly cloudy, with a low around 60. Chance of precipitation is 30%.
Friday
Mostly sunny, with a high near 78.
Friday Night
Mostly clear, with a low around 58.
Saturday
Sunny, with a high near 79.

 

[TheClimateChanger]

11 hours ago, TheClimateChanger said:

Impressive heat in parts of South Dakota today. Winner reached 107F, one shy of the all-time record for the month of September set on September 9, 1931, and the second warmest reading on record for the month. The low of 76F was also the second warmest of record, behind 78F on September 7, 1945. The daily mean of 91.5F was easily the hottest of record in the month of September. The old record was 89.0F, set on September 2, 1983 & September 8, 1931.

In fact, the 91.5F daily mean is the easily the latest in the calendar year that value was attained. A daily mean of 91.5F was reached on August 16, 1988, which is the latest date other than today on which a daily mean equal to or greater than today’s value was attained at Winner, SD.

A couple other observations. The high of 101 in Sioux Falls, South Dakota was the first 100+ reading in the month of September at that location since 1976, and only the seventh year to achieve that figure. The high is again forecast to be around 101F today, and if it achieves that, this would be the first year with more than one 100+ readings in over 100 years (1922 was the last year with that distinction). 
 

The high of 102F at Sioux City, IA was the first 100+ reading in the month of September at that location since 2000, and was also just one shy of the monthly all-time record of 103F. This was also only the eighth year that has reached 100 in September. Should it reach 100 today, it would be the first year with more than one 100 degree reading in September since 1939, and third overall (1895, being the other).

[King James]

It’s actually beautiful out

[Brian D]

84 lakeshore, and 88 at the airport here yesterday. Peak heat today. Will see how close we can get to 90 on the shore. 87 is the highest temp so far this summer. I haven't needed to use a window A/C this year, and not going to put it in for this. 77 in the house right now, and expect that to be 80+ later this aftrn. Fan will suffice.

[Brian D]

Some of you may remember I mentioned a few weeks ago about Labor Day week looking Fallish. This is what I was expecting to see. Highs will be near to or lower than current lows this weekend here in the N sub. Fast switch over.

[Geoboy645]

Interesting note, there is currently a Red Flag warning for the SW and Central areas of Wisconsin. From what I can tell at least since IEM records start in 1986, this is one of if not the first time that these areas have been under a Red Flag warning at this time of year. In fact this is only the 10th time MKX has ever issued a Red Flag warning in general. Not very surprising considering the drought, and with the holiday weekend there are certainly quite a few potential ignition sources. Especially considering that people don't really think of fires all that much in this part of the country, and especially not outside of March/April during our usual fire season. 

[hawkeye_wx]

It feels like this is never going to end.  This summer will get a big fat F grade from me (edit: maybe a D because there has been plenty of pleasant weather).  We haven't had a month since April in which we received more than 50% of avg precip.  If this latest Euro forecast pans out, we will have gone a month will <0.10" of rain.

[Brian D]

93-96/75-78 (heat index around 105-113) around here, with 80 in the house. Hottest day of year here. Won't see the official co-op temp on the shoreline until tomorrow morning.

[weatherbo]

1 hour ago, Brian D said:

93-96/75-78 (heat index around 105-113) around here, with 80 in the house. Hottest day of year here. Won't see the official co-op temp on the shoreline until tomorrow morning.

Didn't tag 90 like expected... peaked at 87.  Another shot tomorrow, point has 90 again.

[hawkeye_wx]

It's hot today, but there's a huge difference between 95 with a dew of 80 (last heat wave) and 95 with a dew of 58.  A couple hours ago I was outside for a good ten minutes in the hot sun and I didn't even begin to sweat.

[TheClimateChanger]

Okay, so Duluth might be the most impressive record yet. Hit 97 today, breaking the previous September all-time monthly record by 2 degrees set on September 7, 1976. It shattered the daily record by 8 degrees. Prior to today, the latest 97 or higher reading at Duluth was on August 1, 1930, when it also reached 97 degrees. Which is to say, yes, this would have tied the August monthly record as well.

The low of 71, should it hold, would be just one shy of the highest on record for the month. And the mean of 84F easily bearing the prior record of 82F. Both of those records are from September 11, 1931, I believe.

I do say “should it hold” since I am aware Duluth is prone to lake breezes which can result in rapid temperature swings. I don’t believe that’s the case today, but I didn’t investigate.

 

[TheClimateChanger]

Brainerd reached 102F today, one shy of the September monthly record set on September 10, 1931. It was the hottest day since July 15, 2006, and would have matched the August monthly record which was set on August 4, 1947. Only four days in recorded history were hotter than today at Brainerd - the aforementioned 103F reading from September 10, 1931; July 10, 1936 (106F); July 11, 1936 (103F) and July 12, 1936 (103F). Which is to say it has not been hotter than today at Brainerd since July 12, 1936, during the most impressive heat wave of the Dust Bowl. At more than 87 years ago, I would venture to guess few living Brainerdians have experienced a day hotter than today, and fewer still would have been old enough to recall it.

It has now reached 100F or better three years in a row - it was 100F on June 4, 2021 (earliest on record) and 100F on June 20, 2022. Both of those dates tied the June monthly record of 100F set on June 19, 1988. It does not appear there had ever been two years in a row with a 100+ reading prior to the current stretch of 3 years.

This in a place better known for snow and the Coen brothers cult classic, Fargo, which, of course, featured plenty of snow and a gory wood chipper.

 

 

[Spartman]

89'd again today. Still feel it's the highest it's going to get for this month. With the last 90 hit back on August 23rd, the 90s seem to be maxed out for the year.

[madwx]

record of 94 today at MSN.  beat the old record by 2 degrees.

[TheClimateChanger]

Stevens Point, Wisconsin reached 102, with a dewpoint falling into the 30s: National Weather Service : Observed Weather for past 3 Days : Stevens Point Municipal Airport

Not a first order site, however, so there could be data problems. Very limited period of record and a lot of missing data, but looking back to 2009, the highest I could find there prior to today was 97F on June 6, 2011, July 17, 2011 & July 20, 2011.

Just to the north, at a first order station with a long POR, Wausau reached 99. This matches the September monthly record set on September 10, 1931. It also matches the highest reading ever recorded in the month of August - 99 was observed on August 2, 1964; August 16, 1988; August 21, 1955; and August 24, 1948.

Since 1936, only one date has been warmer than today at Wausau - July 13, 1995, when it reached 102F. That is also the only 100+ reading since records moved to the airport in 1942 in the threaded station history. There were 14 100+ readings prior to the station move - half of which occurred in 1936, and all but one of which occurred between 1931 and 1936.

[TheClimateChanger]

Here is the regional weather summary for northern Wisconsin, showing several stations in the low 100s today.

[Brian D]

Records around my area. Looked at PWS's, and around the S end of the Duluth Harbor, and Superior, WI many 100+ away from the lake shore. This area is close to lake level (600'), and the hills (~1100') to the west have down sloping winds (even if they are light) that produce a mini chinook style heating. Interesting tho was the PWS's in the Duluth downtown, and neighborhoods along the lake shore only made it to low-mid 90's as the airport hit 97, which is about 5 miles inland. Normally it gets hotter like the other areas did, but the lake (including the main harbor) must have helped keep the temps subdued slightly. Exact wind direction is a big factor. West to W/SW tends to up the temps, but more SW runs parallel to the shoreline/ridgeline. 

Didn't realize it was so darn hot in 76'. Just a kid then, so ya don't pay attention to that stuff. HOT WHEELS was the thing LOL!

Currently in the mid-upper 60's at 2:30 am. Feels really nice coming through the window. Main floor of my house was up to 82. Sweatin!

[TheClimateChanger]

HRRR suggesting up to 100F in parts of the western UP, south of the Keweenaw Peninsula. Here is the sounding for 46.81N, 88.68W for 21z, showing a temperature of 100F and dewpoint of 48F.

[TheClimateChanger]

@Brian D Here is what I have for August in the lower Lakes region. August 2023 was near the long-term mean, but a bit below trend. In general, warmer anomalies were noted in the western parts of the region, with cooler anomalies in the east last month.

Quick sanity check. NOAA's NCEI for the whole Great Lakes region also has August 1947 as warmest, with 1955 & 1995 tied for 2nd, and 1959 & 2016 tied for 4th. They have 2021 in 7th place, and I have 1959 in 6th place. They have 1900 in 6th place, whereas I have it in 7th place in my dataset. So the top seven are identical, just in different orders. I may have a residual urban warming bias, resulting in recent years placing slightly higher. But again I'm focusing on only a subset of this basin, so it's not an apples to apples comparison.

They have 1927 as coldest, followed by 1915. I have 1927 as the coldest in the post 1895-era, and 3rd coldest overall. 1915 is the 2nd coldest in my dataset in the post-1895 era, and 6th coldest overall. Overall, the rankings match pretty well with NCEI's rankings for the Great Lakes basin in the post-1895 era.

[TheClimateChanger]

Some insight on the pre-1895 cold years. 1836 was a volcanic summer following the eruption of Nicaragua's Cosiguina volcano. According to an analysis by Berkely Earth, global land temperatures plummeted around 0.75C. And this was already a cooler period towards the end of the Little Ice Age. See here: Cosigüina - Wikipedia

I have a mean temperature of 61.9F at Fort Dearborn in Chicago, 60.5F at Fort Dearbornville in Dearborn, Michigan, 63.0F at Rochester, New York, and 68.5F at Allegheny Arsenal in Pittsburgh [elevation: ~700 feet]. These are averages of 7 am, 2 pm and 9 pm measurements, and keep in mind, these times predate daylight saving time and standardized time zones. Local solar time was still in use, so there's a small warm bias (more predominant early in the summer) since the 7 am reading would have been well after sunrise. The 9 pm reading was included to partially ameliorate this effect, but there is still a significant residual bias.

August 1866 was also very chilly. Here are the daily maximum and minimum readings for Lansing, Michigan and downtown Toronto, Ontario, from that month. At Toronto, the mean temperature was 61.2F, with an average maximum temperature of 69.7F and an average minimum temperature of 52.7F. The maximum temperature for the month was 77F, recorded on August 1, 6 & 7. The coldest reading was 42F on the 24th.

At Lansing, the mean temperature was 59.9F, with an average maximum temperature of 71.6F and an average minimum temperature of 48.3F. The maximum temperature for the month was 80F on the 14th, and the coldest was 34F on the 24th.

August 1866 is the coldest August on record for both Lansing and downtown Toronto. I have no data for either location in 1836.

Not too concerned about urban warming impacts, because you have to look to small towns in far northern lower Michigan to find similar mean temperatures for August among relatively more modern records. The coldest August on record for Houghton Lake (population: 5,294; Roscommon County population: 23,459) is 59.7F, in 1919. The coldest August on record for Alpena (population: 10,197; Alpena County population: 28,907) is 60.1F, set in 1934.

 

[Geoboy645]

 

[Brian D]

89'd for TH co-op on the shore yesterday, but that temp is marked for today (typical of a.m. stns), and is a record beating 1897 (87). Yesterday it would have been 2nd to 1925 (91). That was the hottest day of the year for the co-op site. Awesome heat wave for 45N in the sub.  

Looking forward to potential heavy rains tomorrow into Wed. BRING IT! Need lots to make up for the deficit we have. Since May 1st only 7.74" (15.06" avg) so running at ~50%. YTD is 16.05" (21.42" avg) so that's a little better.

[Brian D]

4 hours ago, TheClimateChanger said:

@Brian D Here is what I have for August in the lower Lakes region. August 2023 was near the long-term mean, but a bit below trend. In general, warmer anomalies were noted in the western parts of the region, with cooler anomalies in the east last month.

Quick sanity check. NOAA's NCEI for the whole Great Lakes region also has August 1947 as warmest, with 1955 & 1995 tied for 2nd, and 1959 & 2016 tied for 4th. They have 2021 in 7th place, and I have 1959 in 6th place. They have 1900 in 6th place, whereas I have it in 7th place in my dataset. So the top seven are identical, just in different orders. I may have a residual urban warming bias, resulting in recent years placing slightly higher. But again I'm focusing on only a subset of this basin, so it's not an apples to apples comparison.

They have 1927 as coldest, followed by 1915. I have 1927 as the coldest in the post 1895-era, and 3rd coldest overall. 1915 is the 2nd coldest in my dataset in the post-1895 era, and 6th coldest overall. Overall, the rankings match pretty well with NCEI's rankings for the Great Lakes basin in the post-1895 era.

Yeah, your anoms in recent years are a bit warmer than the rest of the sub, but the SE sub did have warmer conditions. UHI is always on the table to some degree (even in small towns). It depends on siting. 

Datasets will start updating by the end of this week into early next week. The start of this month with a holiday weekend will delay things a little. Others update later in the month, so I'll have my chart up in about a week or so with prelim data. The sub was split, so should be near avg overall I believe. 

[cyclone77]

Soybeans and corn has really dried up the past week as we move more into Sep.  Harvest season not too far away.

[Chambana]

10 minutes ago, cyclone77 said:

Soybeans and corn has really dried up the past week as we move more into Sep.  Harvest season not too far away.

yep noticed that as well. T minus 4ish weeks until we get that first true autumn cold front, although with a potential super Nino, who knows how this autumn plays out. 
 

regardless, I’m ready for deer chili, football and jeans/sweatshirt weather. 

[rainsucks]

this weather is dogshit, can’t wait for the cooldown.