Monthly Archives: August 2014

a bit drier, maybe gusty winds

1PM, Friday, August 29, 2014



I got back in Colorado yesterday at the end of our string of showery days. The good news is that the showers around this afternoon will be more hit-and-miss, and the number of showers and thunderstorms over the 3-day weekend will be low, so some areas may not get wet at all. Watch for brief spells of afternoon lightning in the mountains. Temperatures should be near average, which in the lower elevations means maximums within a few degrees of 80.


One element to be aware of is the wind. A broad portion of the jet stream will sag toward Colorado. It’s not the kind of setup that is expected to bring widespread precipitation or a strong cold front, but it could kick up some gusty west winds at times, especially Sunday-Monday.


It’s looking warm next week to start September.



Moist today, slightly cooler than average into next week

Friday, August 22, 2014, 11 AM MDT


A developing southward dip in the polar jet stream located to the west of Colorado caused more moisture than expected to surge northward into the Front Range region. It’s not very often we wake up to thunder in the morning!  The atmosphere remains moist, so numerous showers and thundershowers are likely to redevelop today, and a few spots may get heavy downpours.

The dip in the polar jet stream should move across the Rockies this weekend and keep temperature a bit cooler than average, especially Sunday, but nowhere near record cool.  The coverage of thundershowers should decrease this weekend, but the threat should till be around. It might get quite cool during showers along some of the high elevation trails in the state.

Still another cool front should move across the state in the Tuesday time frame, and may bring with it another period with greater coverage of showers.

Thundershowers today, less chance over the weekend

Thursday, 14 August 2014, NOON MDT


Moisture content in the atmosphere over Colorado is up today and thus we have a good chance for thundershowers this afternoon and evening. The moisture won’t hang around for very long as westerly winds push it mainly to the south and east of Colorado on Friday. Friday through Sunday should dry and warm, with only very small chances for afternoon thunderstorms.

No big changes over the next few days

1:00 PM, Thu, August 7, 2014


Today’s moisture content in the atmosphere is bumped up a bit which is leading to a fairly large number of showers and thunderstorms, and some local areas with brief heavy rain.


Tomorrow is likely to see a reduced chance of thunderstorms, but still close to the average chance.  That would be about a 25% chance in Denver-Boulder. But for any specific times tomorrow (like NCAR’s up-the-hill race) the chances are smaller than 25%, but not zero.


The weekend is likely to bring temperatures pretty close to average. No major precipitation makers appear to be headed this way for the weekend, but be prepared for the typical afternoon thunderstorms and the hazards that go with that.

Warm, with a few thunderstorms around

August 4, 2014, NOON


The latest surge of monsoon moisture from the south will impact mostly areas of western Colorado and Utah where numerous thunderstorms are likely this afternoon and Tuesday afternoon. For the Front Range region, the chance for local heavy rainfall amounts is quite small.  But some portions of the Front Range will probably receive a brief thundershower or a brief period of gusty winds and thunder this afternoon or Tuesday. It doesn’t appear that we will receive any major weather events later in the week either, and temperatures should be close to average.



Weekend: some showers/thundershowers, long dry periods

Friday, August 1, NOON


Warm weather (not hot) is in store for the next three days, with only small chances for afternoon showers/thunderstorms in the Denver-Boulder-Fort Collins-Cheyenne area. I wouldn’t be surprised if there is no afternoon shower activity on Saturday. The chance for afternoon thunderstorms is a little greater for the mountains south of I-70 and for the Front Range from Colorado Springs and south, especially today.


The fetch of tropical Pacific moisture (the monsoon) that affected us this week is being pushed a bit to the south and west of the Front Range region, but not very far. It appears that a significant pulse of moisture may move northward into western Colorado early next week, and possibly over the Front Range, enhancing the chances for rain. An update will be issued Sunday or Monday if needed.  For those who don’t know, mid July through mid August is the climatological peak for rainfall associated with the North American monsoon in Colorado. Last September’s remarkable surge of tropical moisture was after the typical peak in the monsoon season.