The State of the Atmosphere: Sunday, July 17, 2016

It's hard to believe that we're now a bit more than halfway through July 2016. It's always amazing to me how fast we transition from snow-threat to heatwaves around here, with those frosty May mornings now feeling like a distant memory.

If July to date has felt warm to you, you are correct. Denver is averaging 1.1° above normal for the month (so not too bad) with the greatest warmer-than-normal temperature anomalies occurring in the mountains and across extreme southern Colorado through the first half of the month.

CPC month to date temperature anomalies for the United States. Warmer than average for most of central Colorado, with cooler than average temperatures across the northeast plains of the state. Near normal to slightly above normal in Denver.

We have seen some impressive heat so far this month, including the city's first official 100° day since July 7, 2014. Couple that with our recent memory of a relatively cool July in 2015, and a forecast for the remainder of the month that looks quite warm overall, and I think many of us will get to the end of this month more than eager for cooler temperatures.

Medium and long range models suggest the next 10 to 15 days will, by and large, be warmer than normal across the state, with a few breaks from the heat here and there. Here's a look at the latest CFSv2 2-meter temperature anomaly forecast for the 22nd through Aug 1. The takeaway, widespread warmer than normal temperatures across the United States.

WeatherBell Analytics

The week ahead
The two big weather stories for the week ahead will be extreme heat across the central United States, and a return of some monsoonal moisture to the southwest and on up into Colorado.

First, the heat. It looks like, and fingers crossed this remains true, that the worst of the heat will be centered east of Colorado this week. That said, we'll likely see some pretty warm temperatures too by the middle to latter half of the week, with those living in the far eastern plains certainly in the running for temperatures above 100° Tuesday through Saturday.

The heat across the high plains will be impressive, and, downright dangerous. Highs in the triple digits will extend from Texas north well into North Dakota, and will be relentless well into next weekend.

Thursday afternoon forecast 2-meter temperatures | TropicalTidbits

For the Front Range, we may be spared the worst of the heat, especially early on this week. A better chance for storms Monday and Tuesday will help keep temperatures in check initially, but by Wednesday (if our storm chances continue to look lower) we'll likely see highs climb into the mid to upper 90s even around here. The latest GFS MOS guidance suggests highs by Thursday and Friday will be from 96 - 99°F across the metro areas – so plenty hot.

The good news is, we'll also see a return of a pretty good moisture flow to begin the week, which should 1) help our temperatures out for the next several days, and 2) help knock down fire danger if only slightly across the higher terrain. The question is, how far east the moisture will be able to make it, or if the best storm chances remain confined to the high country.

Below is a look at the latest GFS precipitation forecast through Friday. Note pockets of very good moisture across the Colorado mountains, with some extending into the northeast plains:


As for rain chances around Denver... we'll go ahead and bump them up to about 30% for both Monday and Tuesday with plenty of subtropical moisture being advected into the state and forecast PWAT values in excess of 1" suggesting a few heavy 'rainers' across the northern I-25 corridor Monday.

By Wednesday our storm chances likely will drop a bit, but subtropical moisture will continue to be present through much of the week. We'll lean drier (and warmer) Wednesday through Saturday, but keep a chance of storms in the forecast each and every day.

After the recent stretch of dry weather and high fire danger, it's time to do those rain dances folks! Great to see some monsoonal moisture in the forecast, at least for now.