FTB 05-20-2020: Critical Fire Conditions Expand with Severe Weather out East

Issue Date: Wednesday, May 20th, 2020
Issue Time: 9:30AM MDT

— A LOW flood threat has been issued for the Northeast Plains

The low pressure system starts to migrate to the northeast today, which will place the jet stream over western and central Colorado. With increasing surface winds and dry south and southwest flow, fire danger will expand across the state. Today, the Red Flag Warning will also include the Central Mountains, southern Front Range, Southeast Mountains, Raton Ridge and western Southeast Plains. Be sure to tune into your local NWS office for more information.

With the dry air intact over western and central Colorado, not expecting any rainfall activity today. The exception will be over the eastern plains where a nice dry line sets up as the moisture mixes out from west to east with help from a lee trough. This will set the stage for some severe thunderstorms later this afternoon and evening with the main threats being large hail and strong winds. Although, a brief/weak tornado can’t be ruled out over the northeast corner of the state.

Storm coverage looks spotty along the dry line, so anticipating fewer storms over the Southeast Plains. If storms are able to sustain themselves, localized heavy rainfall will be possible. Due to better dynamics near the Wyoming/Nebraska border and a nearly stationary storm line forming, there is higher confidence for localized flooding along the southern end of this MCS. Thus, a Low flood threat has been issued. A cold front drops through overnight, which will help knock down high temperatures tomorrow another 5-7F.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.

Zone-Specific Forecasts:

Northern Mountains, Front Range, Urban Corridor, Palmer Ridge, Northeast Plains & Southeast Plains:

Looks to remain dry over these regions this afternoon with the exception of the Northeast and possibly the Southeast Plains. If storms on the southern end of the MCS drop into the state, expect 2-3 hours of continuous rainfall, which could produce totals just over 2 inches this evening. A Low flood threat has been issued for this reason with the main threats being road and low-lying area flooding. Lower confidence in storms over the Southeast Plains, but if they do form and are able to sustain themselves, they will produce strong outflow winds, large hail and localized flooding. There will be a PM update if confidence in storm formation increases by noon. Fire danger is critical for the southern Urban Corridor, Front Range and western Palmer Ridge, so be sure tune into your local NWS office for the latest.

Primetime: 4PM to 10PM

Grand Valley, Northwest Slope, Southwest Slope, San Juan Mountains, Central Mountains, Southeast Mountains, Raton Ridge, & San Luis Valley:

Today is the peak of fire danger for the week as the jet moves overhead, dry air is in place and warm temperatures will help drop humidity values into the low teens to single digits over a large area. A Red Flag Warning has been issued from 10AM to 9PM for the majority of these regions. Surface winds will again be in the 15 to 25 mph range with gusts up to 50 mph possible. Use caution with any activity that can cause a spark and avoid burning. Be sure to tune into your local NWS office for the latest.