September 2020 General Discussion

[michsnowfreak]

53 at DTW this morning but man did the cold spots radiate. 41 at DTX office White Lake

[Hoosier]

I was looking at forecast soundings from Iowa early next week and the freezing level is "only" about 2000-2500 feet too high to entertain the idea of snow... even in the daytime.  Very impressive airmass.  

[beavis1729]

The 2-day temp drop at DEN later this weekend could be around 63 degrees, from 91F On Labor Day to the upper 20s at some point on Tuesday. So, probably won’t make the top 10, but very impressive for September, and early in the month at that. It hit 101F today, a new all-time September record high. 
 

There have been 10 occurrences of a 66+ degree 2-day temp drop at DEN, but none have occurred in September. They were all Oct-Feb.

Largest 2-day temp drop on record is 76 degrees, from 58F on 12/13/2008 to -18F on 12/14/2008.

[roardog]

So if a city has temps in the 90s or even 100F then it snows a couple of days later, do you think warm ground will be a problem for accumulations? People in our region get worried when it is 40F the day before. lol

[Hoosier]

37 minutes ago, roardog said:

So if a city has temps in the 90s or even 100F then it snows a couple of days later, do you think warm ground will be a problem for accumulations? People in our region get worried when it is 40F the day before. lol

I think it depends on the intensity.  Obviously light rates would struggle after 100 degree temps.  But if it is snowing at like 1" per hour, or better yet 2-3" per hour, I don't care what the temps were a day or two before.  Probably would have quicker settling/compaction than usual though.

[Jim Martin]

Golden sunlight this evening.

[weatherbo]

best climo

 

[Hoosier]

00z NAM took a jump north with the front... summer wx actually sneaks into my hood on Tue.  Not that I'm sold on that outcome.

[cyclone77]

Something tells me our 0.83" since July 31st will be a distant memory in the near future.  Some pretty beefy amounts forecast by many of the models.  

[hawkeye_wx]

Ugh.  The Euro just flipped all the way back to cutting the upper low off over the Rockies.  It never really ejects eastward.  In one run it shifts from Missouri to Wyoming.  C'mon, man.

[michsnowfreak]

5 hours ago, hawkeye_wx said:

Ugh.  The Euro just flipped all the way back to cutting the upper low off over the Rockies.  It never really ejects eastward.  In one run it shifts from Missouri to Wyoming.  C'mon, man.

 Did you think this was going to be easy lol? It's only the beginning of months of model mayhem 

[cyclone77]

Nice soaker overnight/early this morning with lots of lightning and thunder, and the sound of rain thrashing the side of the house.  Picked up 2.64".  

You don't see a point forecast like this very often lol.  Winter storm watch out with a 98 forecast high temp in the meantime. 

 

[beavis1729]

As much as we're talking about Denver, it has been and will be even crazier in Laramie WY.  High of 91F yesterday after it was in the 40s during the AM with haze/smoke from wildfires, then winds gusted out of the NW and it hit 90/3 at an hourly ob, RH 3%.  Laramie is around 7,200 feet elevation. Expecting 4-8" of snow Mon-Tues, with a low near 0F on Tuesday night. 

[Baum]

^

wow.

CENTRAL LARAMIE COUNTY-  
INCLUDING THE CITY OF CHEYENNE  
338 AM MDT SUN SEP 6 2020  
  
...WINTER STORM WATCH IN EFFECT FROM LATE MONDAY NIGHT THROUGH  
LATE TUESDAY NIGHT...  
   
TODAY  
SUNNY. AREAS OF SMOKE. HIGHS 90 TO 95. NORTHWEST WINDS  
15 TO 25 MPH.    
TONIGHT  
CLEAR, COOLER. LOWS AROUND 50. NORTH WINDS 10 TO  
15 MPH IN THE EVENING BECOMING LIGHT.    
LABOR DAY...SUNNY IN THE MORNING  
BECOMING PARTLY CLOUDY. HIGHS  
80 TO 85. SOUTHWEST WINDS 15 TO 20 MPH SHIFTING TO THE NORTHWEST  
15 TO 25 MPH IN THE AFTERNOON. GUSTS UP TO 35 MPH.    
MONDAY NIGHT  
RAIN IN THE EVENING, THEN SNOW POSSIBLY MIXED  
WITH RAIN AFTER MIDNIGHT. WINDY. MUCH COLDER. SNOW MAY BE HEAVY  
AT TIMES AFTER MIDNIGHT. MODERATE SNOW ACCUMULATIONS. LOWS AROUND  
25. NORTH WINDS 15 TO 30 MPH. GUSTS UP TO 40 MPH IN THE EVENING.  
CHANCE OF PRECIPITATION NEAR 100 PERCENT.    
TUESDAY  
SNOW. MUCH COLDER. MODERATE SNOW ACCUMULATIONS. HIGHS  
30 TO 35. NORTH WINDS 15 TO 25 MPH. CHANCE OF SNOW 90 PERCENT.    
TUESDAY NIGHT  
MOSTLY CLEAR WITH A 30 PERCENT CHANCE OF SNOW.  
COLDER. LOWS AROUND 15. 

[cyclone77]

Barometer has fallen from 1018 to 1011 in the last hour.  Getting 40mph gusts on the back end of these rain showers.

[Hoosier]

14 minutes ago, cyclone77 said:

Barometer has fallen from 1018 to 1011 in the last hour.  Getting 40mph gusts on the back end of these rain showers.

I noticed this was hinted at on the guidance.

[Hoosier]

3 hours ago, michsnowfreak said:

 Did you think this was going to be easy lol? It's only the beginning of months of model mayhem 

The models always handle cutoff lows very well.  

[cyclone77]

9 minutes ago, Hoosier said:

I noticed this was hinted at on the guidance.

And in the past 15 minutes the pressure has quickly rebound 2mb back to 1013, with winds barely rustling.  Pretty cool.

[Hoosier]

0.60" at ORD so far today, which is the biggest calendar day rain since July 9.  

[hawkeye_wx]

The initial training storms missed me to the northeast (up to 4-5" fell between CR and Dubuque), but the tail of the MCS dropped a solid line of storms through the area.  I finished with 1.06" of rain.  This may have been the first overnight MCS of the year.

This morning's GFS and Canadian have moved to the Rockies cut-off low scenario, which should put the kibosh on the huge rain totals some models have been spitting out.  The GFS only has another 1.50" falling here all week.

Update:  The 12z UK cuts the upper low of over Utah.  *sigh*

[michsnowfreak]

"Winter storm watch in effect"

 Today, Sunny and hot with a high around 100.

 

Ohhh Denver lol. There's a forecast you don't see every day.

[SchaumburgStormer]

At 2.00” on the nose of much needed rain today. 

[Hoosier]

ORD is trailing MDW and PWK by 3 degrees.  That is a most unusual occurrence especially more recently.

[Brian D]

Another very nice day, but that's over tonight with 40mph+ winds and chilly weather on tap. Winds set to peak during the overnight. Gale warnings up over big lake.

[Hoosier]

Pattern looks to be on the dry side after this regime passes so wherever droughtstein has not been eradicated by next weekend, it shall live on a while longer.

[cyclone77]

Despite being only 66 at 11am MLI made a good run at 90 today, but fell short at good ol' 89.  Hit 85 here, but not till just after 6pm.  Was still 68 at noon before the warm front blasted through.

[Jim Martin]

Another great sunset tonight.

[Hoosier]

Some bust potential on temps around here on Tue.

This almost looks like a springtime map where the warm front gets held up south of Lake Michigan.  Obviously it's not spring and the lake temps are a lot warmer now compared to that time of year, but the weak pressure gradient/low level flow in the area doesn't give me confidence in getting the front farther north.

[Torchageddon]

1 hour ago, Hoosier said:

...the warm front gets held up south of Lake Michigan.

Can it not

I just checked the radar after seeing a view flashes and I was shocked to see the mass of heavy rain and storms heading towards SON. Highest winds of the summer ongoing.

[nwohweather]

That’s a hell of a low north of Lake Superior. Fall looks to be rearing it’s head for you guys