FTB 05-28-2017: A Splendid, Mainly Dry Sunday

Issue Date: Sunday, May 28th, 2017
Issue Time: 9:15AM MDT

— Flooding is NOT expected today

After a busy past few days, visible satellite imagery this morning shows a “severe clear” atmosphere – not a cloud over Colorado. With pressure levels rising in height today, and precipitable values below 0.5 inches statewide, expect large-scale subsidence to keep most everyone dry. One exception will be in the Northeast Plains, where some light showers or a weak storm could pop up this afternoon. The second exception will be over the higher terrain of the Front Range and Central Mountains where the elevated heating could cause a few weak showers (possibly a weak thunderstorm). For everyone else, enjoy this splendid Sunday. Hikers: please remember that a thunderstorm can produce lightning without causing rainfall!

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below (hover over threat areas for more details). For Zone-Specific forecasts, scroll below the map.

Zone-Specific Forecasts:

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

Mostly clear this morning then partly cloudy with some isolated showers possible in the Northeast Plains and higher elevations. Max 1-hour hour rain rates of 0.2 inches in the lower elevations, and 0.1 inch in the higher elevations. Flooding is not expected today. Hikers: be aware that a thunderstorm can produce lightning without producing rain.

Primetime: 1PM to 6PM

San Juan Mountains, Southwest Slope, Grand Valley, San Luis Valley, Northwest Slope, Northern Mountains, Central Mountains:

Sunny this morning then a few clouds possible this afternoon. An isolated shower or perhaps weak thunderstorm will be possible mainly in the Central Mountains. Little if any precipitation is expected to reach the ground. However, lightning is always possible with thunderstorms so hikers be aware. Flooding is NOT expected today.

Primetime: 12PM to 5PM

STP 05-27-2017: Another Day Of Severe Weather, Along With Heavy Rain

Issue Date: Saturday, May 27th, 2017
Issue Time: 10:20AM MDT

Summary:

Friday’s thunderstorm activity started around noon, but did not look like it would be all that impressive until later afternoon. At that point, two distinct storm complexes began to cause impacts. A lone supercell-type storm cross southeastward over the Northeast Plains, producing hail up to 2 inches, heavy rainfall and multiple reports of funnels before moving out into Kansas. By early evening, another complex of thunderstorms formed over the higher terrain of the Palmer Ridge, these storms continued to organize as they moved eastward. They produced over 1 inch of quick rainfall, with up to 2.5 inches of rainfall observed in Yuma and Kit Carson counties. Maximum CoCoRaHS reports yesterday were about 2.55 inches with even higher rainfall very likely falling between rain gages. Flash flood warnings were issued by late evening, with Flood Advisories continuing into this morning. Flooding was reported in Yuma County with the observer stating that several smaller roads were washed out.

Elsewhere, scattered showers and weak thunderstorms were noted across mainly northern CO with a few tenths of an inch of rainfall common.

For precipitation estimates in your area, check out our Precipitation Map below.


Storm Total Precip Legend

FTB 05-27-2017: Showers For Many, But Storms Limited To Southeast Colorado Today

Issue Date: Saturday, May 27th, 2017
Issue Time: 9:55AM MDT

LOW flood threat for Southeast Plains

The main disturbance, responsible for the last two days’ worth of severe weather, will be traversing across Colorado today as seen in the water vapor image below. Upward motion will be favored to the east of the trough axis (tan dashed line) and some support will also be available from a weak jet streak moving out of Colorado this afternoon. Thus, scattered to numerous showers are likely to develop this afternoon, especially east of the Continental Divide. A lee-side surface low pressure trough will once again form today, this time along the NM/CO border. This will act to direct moisture northwest into the Southeast Plains and Raton Ridge area. Storm motions in that region will be on the slower side, in the 25-30 mph range, which is conducive for locally heavy rain. The main factor acting against the chances of heavy rainfall will be limited instability, except for the southeast portion of our state. There, up to 1,000 J/kg of CAPE will be briefly available for convective development, with surface dew point temperatures in the low 50s feeding thunderstorm inflows. All in all, expect isolated to scattered thunderstorms in southeast Colorado today with at least isolated heavy rainfall being a good probability. Thus, a Low flood threat is warranted for that area.

In addition to the precipitation, hail up to 1.5 inches, gusty winds up to 55mph and a weak tornado could accompany the stronger cells.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below (hover over threat areas for more details). For Zone-Specific forecasts, scroll below the map.

Flood Threat Legend

Zone-Specific Forecasts:

Raton Ridge, Southeast Mountains, Southeast Plains:

Partly cloudy this morning, then scattered showers and thunderstorms developing by early afternoon. Max 1-hour rainfall up to 1.8 inches will be possible in far southeast areas, with up to 0.7 inches elsewhere. A Low flood threat has been posted for part of the region for isolated flash flooding, as well as field and road flooding. Hail up to 1.5 inches, gusty winds and a weak tornado could accompany the strongest storms.

Primetime: 1PM to 9PM, with a few showers lingering through midnight

Northeast Plains, Front Range, Urban Corridor, Palmer Ridge:

Partly cloudy this morning with showers and a weak thunderstorm developing by early afternoon. Cooler temperatures today with the increased cloud cover. Max 1-hour rain rates up to 0.6 inches possible. Small hail (up to 0.5 inches) could accompany the strongest cells. Flooding is not expected today.

Primetime: 11AM to 7PM

San Juan Mountains, Southwest Slope, Grand Valley, San Luis Valley, Northwest Slope, Northern Mountains, Central Mountains:

Mostly cloudy with scattered rain and higher-elevation snow showers throughout the day, diminishing by early evening. A weak thunderstorm is also possible. Max 1-hour rain rates up to 0.4 inches, with max 24-hour rainfall up to 0.65 inches. Snow level 10,000 feet, lowering to 8,500 feet (especially north of I-70).

Primetime: 11AM to 7PM

STP 05-26-2017: Heavy Rain, Wind, Hail, Tornadoes All In The Mix On Thursday

Issue Date: Friday, May 26th, 2017
Issue Time: 10:45AM MDT

Summary:

A large disturbance moving in from the northwest began to affect Colorado on Thursday. Showers and thunderstorms were scattered west of the Continental Divide, and much more numerous to the east, especially across the Northeast Plains. Most activity was fairly benign with rainfall up to 0.5 inches commonly seen. However, a few storms farther east caused large hail (up to 3 inches near the KS border!), a few tornadoes and heavy rainfall exceeding 1.5 inches per hour. Highest observed rainfall amounts were about 0.75 inches. However, in rural areas of Washington and Yuma counties, heavier rainfall likely occurred.

In addition to the precipitation, strong winds affected many locations yesterday. Some wind damage was observed over the Southwest Slope, while elsewhere wind gusts in the 45-60 mph range were common across higher elevation locations.

For precipitation estimates in your area, check out our Precipitation Map below. Flooding was not reported on Thursday.


Storm Total Precip Legend