What's in store for Monsoon Season in southern Colorado

If you’re a multi-year resident of Colorado, you know the monsoon and the frequent storms and beneficial rainfall it brings. The storms we’ve seen over the last couple of weeks haven’t been due to the Monsoon pattern specifically – instead they’re due to the decay of an intense El Niño and changes to the jet stream and other wind patterns that brought better moisture in from the Gulf of Mexico. The latest spate this week are partly a result of trapped moisture under a persistent high pressure system – monsoon like, but not the monsoon itself. But, the monsoon is coming.

The Colorado monsoon occurs when high-pressure semi-permanently located in the Gulf of Mexico into portions of the country of Mexico, moves north. In doing so, it changes the wind pattern of the Jet Stream, pulling in moisture from both the Gulf of Mexico, and the Pacific Ocean. This is often aided by a low pressure system called a monsoon low over southern California or northern Mexico. The combination pulls in dramatically higher amounts of moisture to Colorado than we see during other times of the year. Much of our state sees well over a quarter of its annual rainfall during the monsoon – with some regions significantly higher than that!

Each year – the monsoon is different. The main factors influencing it include whether we’re in an El Niño or a La Niña. The position of the subtropical high….and how wet or dry the soil and plants are around our state. This year we’re in between an El Niño or a La Niña and trending toward the latter. That in itself would favor above average monsoonal rainfall.

But, the position and expected location of other weather systems and soil and plant moisture suggest a drier than normal monsoon season – and that’s what the Climate Prediction Center’s seasonal rainfall outlook shows.

That said – even with a below average monsoon, we’re likely to get some good beneficial moisture in August..which we need. Colorado Springs as of Thursday morning was sitting an inch below average for rainfall year to date.

____

Have a question or story idea you would like the First Alert 5 Weather team to consider? Email: weather@koaa.com

Watch KOAA News5 on your time, anytime with our free streaming app available for your Roku, FireTV, AppleTV and Android TV. Just search KOAA News5, download and start watching.