Issue Date: Friday, September 2nd, 2022
Issue Time: 9:05AM MDT
— Flooding is NOT expected today
There will be a minor change to the synoptic pattern today, which will help to increase the chance for precipitation over eastern Colorado. A passing trough to our north is forecast to drop a weak cold front south and through the plains later today, which will help pull in some slightly higher moisture values over the area as indicated by the blue shades in the water vapor imagery below. In addition to the surface boundary, upper dynamics and enhanced convergence over the Palmer Ridge should help produce a little extra vertical motion causing an uptick in precipitation coverage over the plains. PW at Platteville was measured at 0.53 inches this morning, which should increase slightly throughout the day. However, a drier boundary layer and moderate steering flows should limit the flood threat as the isolated storms move south. In addition to storms that develop along the front through this evening, there could be increased upslope flow over the Front Range later this afternoon and evening. Again, limited surface moisture indicate that the isolated storms will be more likely to produce light to moderate rainfall, plenty of virga and perhaps some brief outflow winds, so flooding is NOT expected.
Over western Colorado, PW at Grand Junction was measured below average at 0.54 inches, and with continued subsidence from the High, most of the region should remain dry again today. With slightly higher moisture estimated over the San Juan Mountains, and to a lesser extent the Southeast Mountains, a couple isolated high-based storms may develop again this afternoon with the diurnal flow. Slower SSW storm movement should keep the rainfall confined to the high terrain, and flooding is NOT expected.
Today’s Flood Threat Map
For more information on today’s flood threat, see the map below. If there is a threat, hover over the threat areas for more details, and click on burn areas to learn more about them. For Zone-Specific forecasts, scroll below the threat map.
Zone-Specific Forecasts:
Front Range, Raton Ridge, Urban Corridor, Palmer Ridge, Northeast Plains & Southeast Plains:
There will be two areas of potential rainfall development this afternoon through this evening. One will be over the adjacent plains along the front, and the other will be over the mountains/immediate adjacent plains associated with the diurnal flow. Both areas are expected to have limited surface moisture, which mean the isolated storms are likely to produce lots of virga, brief outflow gusts and only light to moderate rainfall. Over the plains, max 30 to 45-minute rainfall rates up to 0.5 inches will be possible along with the better potential for some strong outflow gusts (up to 50 mph). Over the mountains and adjacent plains, max 30 to 45-minute rainfall rates up to 0.25 inches will be possible. Flooding is NOT expected today.
Primetime: 2PM to 11PM
Southeast Mountains, Central Mountains, Southwest Slope, Northwest Slope, Northern Mountains, Grand Valley & San Juan Mountains & San Luis Valley:
Afternoon temperatures should increase a little today with some fair weather cumulus likely to develop over the high terrain by this afternoon. A couple isolated, light showers may be possible over the high terrain with the best chance of this occurring further south. Storm totals should remain under 0.2 inches with plenty of virga, so flooding is NOT expected.
Primetime: 2PM to 8PM
