FTB 08-12-2019: Mostly Dry Weather Today after an Active Weekend

Issue Date: Monday, August 12, 2019
Issue Time: 9AM MDT

— Flooding is NOT expected today

Chances of precipitation will drop significantly today after a weekend of active weather. The subtropical high has moved to the southeast and is now centered over the Gulf Coast of Texas. This has shifted the southerly flow of moisture to the east, cutting off Colorado from its primary moisture source today. Westerly flow of dry air aloft (yellow line in the water vapor imagery below) will continue to dry out western Colorado and the high country, keeping chances of precipitation low over most areas. A weak shortwave to our south will keep some residual moisture over southern Colorado, giving the area the highest chance for precipitation today. Moisture is high over the eastern plains this morning after yesterday’s rain, with dew points measuring in the upper 50°Fs and low 60°Fs. However, a cold front (blue dashed line below) is forecast to come in from the north, which will mix out moisture over the northern half of the state throughout the morning and into the early afternoon. Weak isolated thunderstorms are forecast early this afternoon over the southern mountain ranges, however fast storm motion and dry surface conditions will keep rain rates well below flood threat criteria. Another round of weak storms is forecast to form over the southernmost Urban Corridor and Southeast Mountains around sundown, moving over the Southeast Plains tonight. No flooding is forecast for 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:

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

The highest chances for precipitation today will be over the southern Urban Corridor, southern Front Range and eastern Palmer Ridge.  Storms are expected to begin over the area early this afternoon, moving quickly to the southeast.  Another round of storms is expected over the Southeast Mountains, Southeast Plains and Raton Ridge tonight.  Storms are expected to dissipate as they move to the east.  Max 1-hour rainfall rates of 0.4 inches are forecast over the area, with isolated totals up to 0.6 inches possible over the Palmer Ridge.  Flooding is not forecast today.

Primetime: 1PM to 10PM

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

Dry air will reduce chances of precipitation to near zero over the northern two-thirds of the area today.  The greatest chance for measurable rainfall will be over the eastern San Juan Mountains, with chances for high-based isolated storms this afternoon and into the early evening.  Max 1-hour rainfall rates of 0.2 inches are forecast for today.  Expect mostly sunny skies and high temperatures in the upper 80°Fs and low 90°Fs.

Primetime: 12PM to 7PM