1 PM MDT, Sunday, May 19, 2019
A powerful storm will move from the 4-corners region, across southeastern Colorado, and into Kansas on Sunday evening through Tuesday. The headlines from the storm Monday and Tuesday could be from a severe weather outbreak with tornadoes in West Texas, Oklahoma, and Kansas. Closer to home we will see a variety of weather in the Front Range region, with some thunder here too. Much cooler than average temperatures will continue into midweek.
The dry slot
With these kinds of storms there is often a dry sector that moves up from the south on the east side of the storm and is known as the dry slot. That will likely affect south central parts of Colorado Monday and Tuesday, so areas along the Front Range from Colorado Springs southward have a lower chance of persistent clouds and wet weather.
Rain and thunderstorms
Showers and a few thunderstorms are likely to develop in some areas this afternoon and evening despite the low clouds and cold temperatures. Tomorrow and early Tuesday will likely see some intervals of rain or drizzle, with thunderstorms developing in some areas in the afternoon. The most intense thunderstorms are likely near the Kansas or Oklahoma borders, but a few strong thunderstorms (with hail) may occur along the Front Range.
Heavy snow (over a foot) is likely above treeline and mainly north of the Pikes Peak region. The snowline is likely to work its way to lower elevations Monday night and early Tuesday. Some snow accumulation appears likely in most areas above 7000 feet (and mainly north of I-70). A couple inches appears likely for Nederland and Estes, with a small chance of more than 6.
Some mesoscale models bring the snow all the way down to the urban corridor late Monday night with a bit of slushy accumulation by Tuesday morning. It appears these models don’t really have temperatures cold enough, but it’s close, and nighttime is the right time if it’s going to happen. I’d say that snow in Boulder, Denver, and Fort Collins is unlikely but not out of the question (about a 20% chance).
Low elevations freezes
A widespread hard freeze is unlikely, but areas of local frosts are possible, especially if there is some clearing on Monday, or Tuesday nights (Tue or Wed morning). It’s probably good to protect sensitive plants just in case.
Whew, and I didn’t even get into the latter part of the week yet…