FTB 07-12-2019: Warm Weather Continues with Chances for Weak Thunderstorms

Issue Date: Friday, July 12, 2019
Issue Time: 9:40AM MDT

–Flooding is NOT expected today

It’s going to be another hot day again statewide but there will be a chance for afternoon and evening thunderstorms to cool things off. The strong upper level ridge is still present overhead but has shifted slightly to the northeast. High temperatures measured in the upper 90°Fs and up to 100°F yesterday over the eastern plains caused dewpoints to drop into the 40°Fs and low 50°Fs over the eastern plains. Midlevel moisture will continue to increase from the southwest throughout the day on the backside of the high pressure. PW at Flagstaff and Tuscon Arizona increased about 0.1 inches from yesterday’s values, measuring 0.75 and 1.23 inches respectively. This moisture, marked by the green shading below, is expected to move over our area throughout the weekend but will not be a threat for today. Weak afternoon thunderstorms are expected over most of the high country and Northeast Plains as moisture comes into the area. A cold front associated with a surface low pressure system over the Nebraska panhandle (marked “L” below) will move into the Northeast Plains this morning. The front is expected to mix out by midday but will provide a density gradient for storm formation this afternoon.

Riverine: As of 9:30AM this morning there are no NWS Flood Warnings or Flood Advisories.  Rivers statewide have seen a gradual decrease in flow due to dry conditions throughout the week.  The gage on the Rio Grande River near Alamosa remains at Action stage this morning but is forecast to retreat below Action stage midday today.

Today’s Flood Threat Map

For more information on today’s flood threat, see the map below. For Zone-Specific forecasts, scroll below the map.

Zone-Specific Forecasts:

Southwest Slope, San Juan Mountains, Central Mountains, Northern Mountains, Front Range, Urban Corridor, Northeast Plains, Palmer Ridge:

Afternoon thunderstorms are forecast primarily for the high elevations and Northeast Plains. Over the high country, lift of midlevel moisture over the mountainous terrain will provide a chance for afternoon and evening thunderstorms. Max 1-hr rainfall rates of 0.2 inches are forecast over the area. Storms may drift slightly off of the foothills and over the Urban Corridor, however dry air underneath the cloud base will limit accumulation to less than 0.1 inches. Over the Northeast Plains and Palmer Ridge, the passage and gradual break down of a weak cold front from the north will provide a boundary for storm formation by midafternoon. Low levels of surface moisture and weak upper level forcing will limit max 1-hr rainfall rates to 0.4 inches.

Primetime: 1PM to 9:30PM

San Luis Valley, Southeast Mountains, Southeast Plains, Northwest Slope, Grand Valley, Raton Ridge:

Dry air at the surface and weaker mountain lift will limit chances of precipitation today. Isolated storms may form over the Grand Valley, Southeast Mountains, and Northwest Slope, but max 1-hr rainfall rates will be limited to 0.2 inches. High temperatures are expected to reach 100°F over the Southeast Plains and Grand Valley again today.

Primetime: 12PM to 8PM