Issue Date: 5/10/2018
Issue Time: 10:00 AM
NO FLOOD THREAT IS FORECAST TODAY.
The ridge of high pressure that has parched Colorado over the last few days will continue its slow crawl towards the east, leaving the state once again dry and with above-average temperatures. For today, expect temperatures near or even a bit warmer than they were yesterday. With very little cloud cover across Colorado as the sun rises, and a lack of moisture for clouds to build on, temperatures will be able to increase more steadily compared to yesterday, when there was at least a weak upper level disturbance that was able to keep a good portion of the state with some amount of cloud cover midday to offer respite from the heat. By the afternoon on the Front Range to the eastern plains, there may be enough instability and moisture to work with in the upper levels of the atmosphere to kick off a few stray thunderstorms, but again, with the dry and hot surface conditions there will likely be very little in the way of measurable rainfall. One notable exception is the far northeast part of the state, where some storms could dump a fair amount of rainfall over a short time period. To get substantial rainfall today, you’d need to travel north to Wyoming or Nebraska, where converging winds and better moisture look primed for an afternoon and evening of high thunderstorm activity. An hourly forecast model run by NOAA, known as the High Resolution Rapid Refresh (HRRR) model, is shown below. The image shown is merely an estimate of radar reflectivity for this evening around peak thunderstorm time. Here we see that Colorado, for better or for worse, might be just missing out on the more widespread thunderstorm activity, with only an isolated storm or two expected for the far eastern plains. No flood threat is forecast for today.
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, jump below the map.
Zone-Specific Forecasts
Front Range, Urban Corridor, Palmer Ridge, Northeast Plains, Southeast Plains, and Raton Ridge:
Arid, summery conditions for today across the entire eastern portions of the state. Much like yesterday, anticipate hot weather and increasing clouds in the afternoon, with the possibility of a few isolated thunderstorms late in the afternoon and into the evening. Don’t expect much in the way of substantial precipitation, however, with gusty winds and lightning being the main sources of hazardous weather. The exception to this is the far eastern and northeastern areas of Colorado, especially in Logan, Sedgwick, and Philips counties, where tonight dew point temperatures might be up into the lower 50’s on top of ambient temperatures in the upper 60’s/lower 70’s at night. This means that with stronger storms a non-negligible amount of rainfall might occur over about a half hour to an hour time span. Under these heavier showers, hourly rainfall rates of 1 to 1.25 inches are possible. While fairly substantial, no flooding is forecast.
Timing for isolated thunderstorms: 3 PM – Midnight
Timing for heavier thunderstorms across the far Northeast Plains: 6 PM – Midnight
Northern Mountains, Northwest Slope, Central Mountains, Grand Valley, San Juan Mountains, Southeast Mountains, San Luis Valley, and Southwest Slope:
Seasonably warm weather will continue to dominate over the mountains and the western slopes today. The majority of this forecast area will enjoy very comfortable weather, with fair weather cumulus and breezy wind in the afternoon hours, and in the high country perhaps a quick shower before the sun begins to set. The only area that has a good chance for precipitation today is up in the northwest, mostly in Moffat County. Here, some showers and storms might begin brewing late in the afternoon and may survive into the evening hours. The lack of good storm dynamics, however, will make it difficult for anything more than a quarter of an inch of rainfall per hour to be observed. The timing of the storms here is from 5pm to Midnight.
