FTB 09-28-2018: Cold Front Passage brings Drizzle and Light Showers to Eastern Colorado

Issue Date: Friday, September 28th, 2018
Issue Time: 09:05AM MDT

— Flooding is NOT expected today

The aforementioned cold front from yesterday’s FTB and FTO has made its way through eastern Colorado this morning. This is brining quite the cool temperatures to the eastern plains with current temperatures in the upper 30Fs to mid 40Fs. Behind the front, there are some low-level clouds and fog as seen in the visible satellite imagery below. Light showers are also being reported over the Southeast Plains. Flow aloft will also turn more westerly today as the trough continues to migrate east and the upper-level high moves over NM/AZ. This should help entrain a drier air mass from the west. The front is rather shallow, so expecting clouds to dissipate west to east as deep mixing occurs in the boundary layer with the drier air aloft this afternoon. Moisture is a bit deeper over the Colorado/Kansas/Nebraska border, so forecasting skies to remain overcast. Light showers will be possible throughout the day but not expecting 24-hour totals to exceed 0.15 inches. Due to the shallow nature of the cold front, only the eastern plains and lower elevations of the eastern high terrains will have afternoon high temperatures affected. This means sunny skies and warm temperatures for the mountains and western Colorado. Tonight, expecting cloud cover to increase as a shortwave moves clockwise around the 500mb high into western Colorado. This should help keep low temperatures a few degrees higher than the last few nights across the state. As you may have predicted, flooding is not expected 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:

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

Cooler high temperatures today thanks to the passage of a cold front. Highs today over the plains will be in the mid-50Fs with temperatures warming into the low 60Fs over the adjacent plains. The mountains will remain mostly unaffected by the cold front minus the foothills. Cloud cover is expected to decrease west to east this afternoon, although overcast skies will remain over the far eastern plains. With limited low-level moisture and instability, light showers and drizzle will be possible west of 104deg as well as over the northern Front Range/Cheyenne Ridge intersect. Totals for the 24-hour period are expected to remain under 0.15 inches, so flooding is not expected today.

Primetime: 9AM to 10PM

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

The shallow cold front should leave these regions unaffected today with highs reaching the mid 80Fs over the lower elevations. With westerly flow aloft, dry air entrainment will keep skies mostly clear, so plenty of sunshine to go around. This evening a shortwave will rotate around the 500mb high, so cloud cover will increase from west to east. This will keep low temperatures warmer than the last couple of days as radiative cooling will decrease.