Issue Date: Tuesday, August 27th, 2019
Issue Time: 9:50AM MDT
—Flooding is NOT expected today
Dry weather is forecast again for most of the state today as a large dry arid mass continues to move its way in from the northwest flow aloft. PW over Grand Junction this morning was measured at 0.3 inches, which is just shy of the daily record low. This value may drop off slightly more, and the lack of moisture should prevent rainfall today over western Colorado. Moisture has somewhat returned to eastern Colorado with Denver’s PW measuring 0.71 inches this morning. Expecting the morning clouds and fog to clear out a bit with some daytime heating (minus the Northeast Plains), and overall looking at highs similar or slightly below yesterday’s high temperatures. The broad region of high pressure that ushered in cooler temperatures yesterday (marked H in the water vapor imagery below) will continue to expand and move east throughout the day. Clockwise flow around the high will bring in moderate levels of moisture to the eastern plains with easterly surface winds turning southerly over the plains.
Ongoing showers this morning over the Northeast Plains (generated by the weak surface low marked below) will likely intensify this afternoon as they move east. This is due to convergence along a cold front dropping south and mixing with the southerly winds generated by the surface high. Lift over the area should also be reinforced by a passing jet streak, so totals may be a little higher than they normally would be. Instability is on the lower end of the spectrum, due to the early nature of the storms, so rainfall rates are expected to remain below flood threat criteria.
Upslope flow is forecast to generate brief thunderstorms over the Raton Ridge and the western Palmer Ridge, similar to yesterday. Westerly upper level steering flows greater than 20mph and high-bases should keep accumulations low and help keep storms moving if they form over the Spring Creek burn area. Therefore, flooding is not forecast.
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:
Northeast Plains, Palmer Ridge, Front Range, Urban Corridor, Southeast Plains, Southeast Mountains, Raton Ridge:
Storms are forecast over the Northeast Plains, Raton Ridge and western Palmer Ridge today. Rain will begin mid-morning over the Northeast Plains with max 1-hour rainfall rates up to 0.85 inches possible this afternoon as storms intensify. A brief, isolated storm may be possible over the Colorado Springs area early this afternoon with max 1-hour rainfall rates up to 0.5 inches. Lastly, the Raton Ridge is expecting another round of thunderstorms early this evening, but westerly surface flow should keep the storms off the Spring Creek burn area. Max 1-hour rainfall rates up to 0.9 inches are possible. Flooding is not forecast today.
Primetime: 9AM to 9PM
Northwest Slope, Northern Mountains, Grand Valley, Central Mountains, Southwest Slope, San Juan Mountains, San Luis Valley:
Near record low PW measurements over Grand Junction this morning will keep skies clear and precipitation chances near 0%. High temperatures should drop off another 3-5°F from yesterday with cooler air advecting in from the north. The reduction in wind speeds has brought the region out of critical fire weather, although there is still elevated fire danger due to the low relative humidity values. Some moderate gusts may be possible over the mountain valleys in the San Juan and Central Mountains, so continue to use caution with open flames.
