mayjawintastawm

Late post: 0.9" snow Friday morning. First of the season. Let 'er rip...

If I had a nickel for every time I saw this in the BOU AFD, I wouldn't need the CARES Act... our snowfall forecast for the Denver metro continues to decrease as most guidance has trended much drier.

Yup, we dropped 21 degrees (from 58 to 37) from 3 to 4 PM with the ever-interesting "BLDU" at APA, another 9 degrees the hour after that, and now it's in the upper teens.

Yeah, looking OK but so far away... My sense is that the QPF is not so much underdone with mesoscale features as that the variability is underdone. Commonly, the typical upslope places (along the Peak-to-Peak, Boulder) get more than predicted, while downsloping places (often Fort Collins, CO Spgs) get less than predicted. Today I looked at the July-Nov climate data for most reporting stations in AZ, NM and CO. The only place that got less precipitation than Denver was Yuma, AZ. How about that.

As my wife's Brooklyn relatives would say, looks like a flying sorcerer.

I'm beginning to think "above normal precipitation" means a relative humidity of 50%. Heck, I'd be excited for a little frost at this point.

It takes a certain length of time of freezing weather (? weeks) to reset the clock on most plants. They are vulnerable if it freezes very hard (<15 F soon after the 60s) in the fall, or if there is a warmup followed by a hard freeze in April/May. This happens with some regularity. Between that and chronic dryness, the Front Range is a tough place to be a tree. On the bright side, this past Spring's moisture and lack of hard freezes produced some of the best fruit crops in many years... apples from our tree are still in the fridge.

Also- these conversations are pretty great and the nerd index is an order of magnitude higher than most other subforums, just sayin'...

Thanks raindancewx! How/where do you get these data? Would love to play around with them some.

Thinking climatologically: how to get data for the driest 4-month, 5-month, 6-month periods for reporting stations? DEN had <1 inch of rain the past 4 months combined- this has got to be up there, if such a record exists.

and good to be wrong... though DEN still has its streak going, most of the metro area saw a nice 0.1-0.2" last evening. Felt downright weird walking around in it.

It's been 41 days since Denver saw 0.1" or more in a day, and 123 days since we've seen 0.25" or more. Any bets on when the next of these will happen? I'll wager 11/7 for 0.1" and 11/25 for 0.25", mainly wild guesses (that may be optimistic).

Heck, I got a bunch of days in at Beech Mountain in early December many years ago, not bad really. Wet oak leaves are as slippery as packed powder if you play it right. Best resource IMHO is opensnow.com for mountain-specific weather and long range hints (that you may have to pay for, but may be worth it). Biggest thing about early snow here is that Oct-Jan is the driest time of year in CO. The big storms typically hit in Feb-April. But the 'Boat is good about making snow, to justify its $200/day price tag for a ticket.

Here's to the end of a long dry spell, maybe??? 0.8" of rain at DEN in the 92 days going back to 6/29. If there were more trees around here, I'd worry about fires. And I'm flying back from the East coast on 10/20, so that tracks pretty well.

Hopefully tomorrow (or maybe today) will be the last 90 degree temp of 2021 in Denver. We have lived here for 12 summers. 11 of them (all but 2014) have been in the top 20 for most 90 degree days in Denver.

Denver was 2 degrees below normal on August 21. Cheyenne was 2 degrees below normal on August 29. I couldn't find any reporting stations with climate normals on the northern Front Range in CO.

And 97 today, 3 record highs in a row. The low this AM was only a couple degrees cooler than the record high min too. September is the new July, only drier. I wonder if the hydrology folks will start talking about flash drought, though many places on the Eastern Plains have had some soakers to hold that off.

And, in the "why am I not surprised" department, it's looking like this August will be #4 warmest in Denver, in the 150th year of record keeping. Last August was #1 and 2019 will be tied for #5. So, 3 years in a row of top 5 warmest Augusts. Wow.

Thanks for looking into this! I've felt the same. I'll have to dig into that database. Similar here south of Denver, though up through July 5 was actually pretty good. Jul 5-Aug together have been between 0.8" and 1" total. When it's dry here for months in a row, the soil in our backyard shrinks (even despite watering the lawn), causing the patio to sink and the (fortunately just cosmetic) vertical beams between the overhanging roof and the patio to float in midair. Right now they are about 1.5" over where they should be. In the spring, everything was perfectly flush.

yeah- soil type (less permeable here, very drainable there), prevalence of streams to drain water away (few here, more there), and terrain (steeps and plains here, rolling hills there) are all different. I don't know much about flash flood modeling, but I imagine there is an algorithm that takes those into account.

Is it just me, or is September (or late August) the new June when it comes to severe events? Not as many, but just as strong.

In the "should we be jealous?" category, my old neighborhood in Shrewsbury, MA (just east of Worcester) just got 3.2" of rain this morning in under 2 hours from the remnants of Fred, with a maximum rain rate of 3.78"/hour at the peak. It's done now... though Henri may be interesting in a few days. I don't think I've ever experienced rain that heavy. Lots of localized flooding, but that area can take heavy rain with fairly minimal damage- probably mostly basements that need to be pumped out and cars turning into boats in low lying areas.

Indeed- since 7/5 we've had 0.4" rain. There are distribution issues! VV- cannot believe that is a road with those boulders, wow!

Well, in late August climatologically you often get the first cold fronts of the season coming down from Canada into the Northern Rockies on north to northwest winds. The 6-10 day forecast hints at that. At the same time, climatologically we're getting into the worst of fire season, and fires don't stop at the Canadian border. So while you have a smaller chance of being affected by the CA and OR fires, those in WA, BC and Alberta might be more likely to be in play. Good luck. I'm so tired of not being able to see the stars or the mountains on "clear" days from Denver.

Dang, good luck. Meanwhile here we’ve had a trace and Centennial Airport has had a whopping 0.01”.