Author Topic: From one extreme to the other  (Read 1354 times)

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Offline SlowModem

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From one extreme to the other
« on: September 03, 2020, 09:32:53 AM »
This may be common for Colorado, I donno.  But it looks extreme to me.  Going from temps in the 90s to temps that are good for snow.  I know there are differences in elevation and differing snow levels, but this from the NWS just caught my eye.

Quote
.LONG TERM...(Friday through Wednesday)
Issued at 321 AM MDT Thu Sep 3 2020

For Friday and this weekend, the strong upper level high will
remain over the southwest part of the country. This will result in
hot and dry conditions for Colorado. Temperatures will warm into
the lower 90s Friday across northeast Colorado. For the weekend,
highs will reach the mid to upper 90s. A few low 100s will also be
possible across the eastern plains. Other than some afternoon
cumulus clouds, clear skies should persist through the weekend.
Winds look weak through at least Saturday. A lee side surface
trough may form over eastern Colorado Sunday causing the winds to
pick up some.

The upper level high starts to retrograde westward Sunday and
continues to shift west on Monday. A short wave trough and cold
front push through the area Sunday night. Not enough moisture for
precipitation, but this will bring cooler temperatures for Monday.

Models agree a strong trough will dig south into the Northern
Rockies Monday. They then diverge for Tuesday. The ECMWF continues
to show this trough digging southward and closing off over the
Great Basin/Four Corners. The GFS has a sharp open trough moving
across the Central Rockies and closing off over the Central
Plains. Both of these solutions and anything in between will bring
much colder temperatures for Tuesday and Wednesday. What is
highly uncertain is the amount of precipitation. The GFS solution
would generally be a light precipitation event. Meanwhile, the
ECMWF shows most locations receiving greater than a half inch of
precipitation and upslope areas along the Front Range getting over
an inch of precipitation Monday night and Tuesday. This will be a
very cold system for this time of year. Snow level will likely
fall well down into the foothills with a chance it ends up lower.
Greg Whitehead
Ten Mile, TN USA

Offline Bluefudge

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Re: From one extreme to the other
« Reply #1 on: September 04, 2020, 10:15:39 PM »
That is definitely crazy!  I was reading elsewhere that they've definitely had bigger temperature swings in a short period of time but in the winter time and not in September and never from 90's to snow the next day. 

Offline hofpwx

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Re: From one extreme to the other
« Reply #2 on: September 06, 2020, 01:39:34 PM »
I’m a Denver-area-born Colorado resident of many years and this kind of variability in the “shoulder” seasons (spring and fall) is not uncommon along the Front Range.

We’re under Red Flag Warning (fire ban) and a winter storm watch at the same time. August was very dry in Denver and a tie for warmest August on record, going back to 1872. So far this summer, we’ve had 72 days of a high temp 90F or above - the record is 73, set in 2012. Most of the state is in drought conditions as well.

We have huge swings here which make it exciting! If I get good data from my station on the temperature swings I’ll post it here.

Offline Tarma

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Re: From one extreme to the other
« Reply #3 on: September 07, 2020, 09:34:16 AM »
Temperature swings do happen in the mountains (Utah), but this one is more extreme that I remember. Should be interesting. I will just be glad to be rid of the 90s!

Offline hofpwx

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Re: From one extreme to the other
« Reply #4 on: September 07, 2020, 09:46:57 AM »
Current forecast is 3”-7” Tuesday daytime, 3”-5” Tuesday overnight, total 6”-12”. Wow.

Offline Jasiu

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Re: From one extreme to the other
« Reply #5 on: September 07, 2020, 11:22:54 AM »
Hopefully this helps put out a few fires.
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Offline Tarma

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Re: From one extreme to the other
« Reply #6 on: September 07, 2020, 12:48:17 PM »
I have to say this is an interesting combination of warnings  :eek:


Offline hofpwx

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Re: From one extreme to the other
« Reply #7 on: September 16, 2020, 10:29:20 AM »
Excellent summary from the NWS.

https://www.weather.gov/bou/Sept2020EarlySnow

Offline DRWS

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Re: From one extreme to the other
« Reply #8 on: October 27, 2020, 11:33:57 PM »
This was originally posted in the wrong thread I guess. But if everybody would like to know who and what are causing these extremes, watch the video from 1Pacific Redwood on YouTube .
https://www.youtube.com/watch?v=5hB_hFa58Lo&t=633s
Just got this YouTube video. It talks about installed high pressure and climate. These videos are top notch, 1PR knows what he is talking about. I have been researching this activity for 40+ years.
« Last Edit: October 28, 2020, 02:34:36 PM by DRWS »

Offline vladcoroeanu

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Re: From one extreme to the other
« Reply #9 on: October 28, 2020, 10:05:11 AM »
OK, but the current Utah central mountain temperature are 25°F. So...
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Offline DRoberts

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Re: From one extreme to the other
« Reply #10 on: November 02, 2020, 11:17:39 AM »
Looking for another diurnal range of 50+ degrees today. Low was 19 and high forecast to be 72. We shall see. Update on this. Current temp 77 so a 58 degree range from 6:50 a.m. to 2:57 p.m.