STP 05-31-2017: Scattered, Slow Moving Storms Found Across Southeast Colorado

Issue Date: Wednesday, May 31st, 2017
Issue Time: 10:45AM MDT

Summary:

Although under the influence of a weak ridge, early morning sunshine statewide boosted temperatures and created the instability necessary for storm development. Multiple rounds of slow moving thunderstorms were observed mainly across southeast Colorado. Most storms produced only very short-term heavy rainfall because a lack of shear meant that the rainfall actually impeded on the updraft. Common totals were in the 0.25 to 0.5 inch range. However, a few more organized complexes produced rainfall exceeding 1 inch in El Paso, Pueblo, Huerfano and Baca counties. The highest rainfall totals was 2.41 inches from Baca County, right along the Kansas border from a slow moving storm that trekked across the area near sundown.

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


Storm Total Precip Legend

FTB 05-31-2017: Showers and Storms Expected Again This Afternoon

Issue Date: Wednesday, May 31st, 2017
Issue Time: 10:40AM MDT

LOW flood threat for parts of Northeast Plains, Palmer Ridge, Raton Ridge and Southeast Plains

With plenty of morning sunshine, temperatures will continue their steady trend upwards today across Colorado. Moisture also continues to increase, albeit slowly, as weak southeasterly flow brings in moist air from the Southern Plains. Added to the mix is an approaching disturbance from the southwest (see water vapor image below) that will cause upward motion downstream of its vorticity axis. Collectively, expect shower and storm coverage to increase today across southwest and eastern Colorado. Most rainfall will be of the light to moderate variety, and not pose a flood threat. However, two areas are exceptions to this rule. First, along the Raton Ridge, early instability will provide scattered storms that will be capable of heavy rainfall due to slow storm motion (much like Monday). Second, in the Northeast Plains and far eastern Colorado, higher instability and favorable directional and speed shear profiles suggest isolated severe storms. With precipitable water approaching 0.7-0.8 inches this afternoon, isolated heavy rainfall will be possible with these. In addition, large hail is also possible.

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:

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

Mostly clear this morning then partly to mostly cloudy with scattered showers and thunderstorms developing by early afternoon. Highest coverage will be in the foothills as well as in the Northeast Plains, with a lull over the Urban Corridor. Max 1-hour rainfall up to 1.8 inches. A Low flood threat has been posted for parts of the region for isolated flash flooding. Large hail, up to 2.25 inches could accompany the strongest storms Northeast Plains.

Primetime: 2PM to 9PM

Raton Ridge, Southeast Mountains, San Juan Mountains, San Luis Valley, Southwest Slope:

Partly cloudy this morning the scattered showers and thunderstorms possible this afternoon. Max 1-hour rain rates up to 0.5 inches west of the Continental Divide (max 24-hour rainfall up to 0.8 inches), and 1.1 inches to the east. A Low flood threat has been posted for parts of the region for isolated flash flooding, debris slides and mud flows.

Grand Valley, Northwest Slope, Northern Mountains, Central Mountains:

Sunny this morning then becoming partly cloudy with isolated showers and a weak thunderstorm possible mainly in the higher elevations of the San Juans and southern portions of the Central Mountains. Max 1-hour rainfall up to 0.3 inches. Small hail (up to 0.25 inches) could accompany the stronger cells. Flooding is not expected today.

Primetime: 12PM to 7PM

STP 05-30-2017: Scattered Showers And Storms With A Few Heavy Downpours

Issue Date: Tuesday, May 30th, 2017
Issue Time: 10:55AM MDT

Summary:

A strong late May sun quickly boosted morning temperatures on Memorial Day Monday. As a result, scattered showers and storms erupted along the mountains and foothills east of the Continental Divide before noon. Early storms were not particularly impressive, but as the afternoon wore on, storm updrafts and outflow boundaries combined to form bigger storm complexes. By late afternoon, a few heavy downpours were noted in the Urban Corridor, Palmer Ridge, Southeast Plains and Southeast Mountains. One of the strongest storm cells of the day happened to pass right across a quality controlled USGS rain-gage located in the Pinon Canyon Military Reservation. About 1.5 inches fell over a 3-hour period there, with a few shorter term downbursts in the mix. Other storms moved over the Urban Drainage and Flood Control District’s gauges with up to 0.6 inches falling per 30 minutes.

In addition, a few hail reports, up to penny size, were received with the strongest storms.

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


Storm Total Precip Legend

FTB 05-30-2017: More Scattered Storms Expected, A Few With Heavy Rainfall Potential

Issue Date: Tuesday, May 30th, 2017
Issue Time: 10:50AM MDT

LOW flood threat for parts of Southeast Mountains, Raton Ridge and Southeast Plains

Another crystal clear start to the day today will allow for strong insolation as we are getting closer to summer’s peak heating. At the upper-levels, as the water vapor image shows below, a large trough continues to be centered across central/eastern North America. As the trough slowly continues to move eastward through the day, Colorado will be increasingly affected by subsidence from the high-pressure ridge to the west. However, its impacts will be felt more so west of the Continental Divide. To the east, elevated heating will cause a weak upslope circulation to develop especially in southeast Colorado. With just enough low-level moisture, scattered showers and thunderstorms will dot the landscape by the afternoon. While the storms won’t be overly impressive, they will be steered by very light winds, less than 25mph. Thus, they will be capable of producing isolated heavy rainfall, much like on Monday. A Low flood threat is posted today for the foothills of southeast Colorado for isolated flash flooding, debris slides and debris flows.

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

Mostly clear this morning then partly cloudy with isolated to scattered showers and thunderstorms possible. Highest coverage will be in the foothills and western plains of southeast Colorado. Max 1-hour rainfall up to 0.6 inches except up to 1.1 inch in southern areas. A Low flood threat has been posted for parts of the region. Small hail up to 0.5 inches could accompany the stronger cells.

Primetime: 2PM to 8PM

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

Sunny this morning then becoming partly cloudy with isolated showers and a weak thunderstorm possible mainly in the higher elevations of the San Juans and southern portions of the Central Mountains. Max 1-hour rainfall up to 0.3 inches. Small hail (up to 0.25 inches) could accompany the stronger cells. Flooding is not expected today.

Primetime: 12PM to 7PM