FTB 08-12-2017: Severe Storms for the Northeast Plains

Issue Date: Saturday, August 12, 2017
Issue Time: 10:00AM MDT

— LOW flood threat for portions of the Palmer Ridge and Northeast Plains

Lots of low level clouds and fog to start off the day over the eastern plains. Otherwise, it is sunny across the state this morning with highs today about average for August.  Precipitable Water (PW) this morning at the Denver sounding showed 0.79 inches with some drying in the mid-levels. PW was a bit higher in Grand Junction at 0.83 inches. The higher PW values are once again located over the eastern plains and should stay confined to this area this afternoon and evening. With drying in the mid-levels, this should limit widespread heavy precipitation and promote damaging winds.

500mb flow will bring moderate NW flow over the state. A shortwave trough makes its way down from NE/WY this evening, which will help support thunderstorm activity as it moves over the Northeast Plains. This area also has the best instability and shear, so this may support some severe storms with large hail and gusty winds. The storms merge into a line of convection and move E/SE in the evening hours. The clearer skies throughout the day will also help form more instability over the mountains and allow more widespread coverage of thunderstorms development over the northern portion of the state today. Expect storms to start firing over the high country this afternoon and favor the Northeast Plains and Palmer Ridge as they move off into the adjacent plains. The flood threat should end a couple hours after sunset.

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:

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

Fog burning off becoming mostly sunny this morning and partly cloudy this afternoon.  Some severe storms are possible today over the NE Plains with the main threats being damaging winds, large hail (2 in) and field and road flooding. Max 1-hour rainfall up to 2 inches (east), 1 inch (west). Riverine flooding along the Arkansas River is not expected today. A Low flood threat has been issued today.

Primetime: 2PM to 11PM

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

Sunny this morning with some showers over the Northern and San Juan mountains this afternoon. Max 1-hr rainfall up to 0.8 inches. There is a no flood threat for today.

Primetime: 12PM to 8PM