Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 350 PM EDT Fri Jul 23 2021 Valid 00Z Sat Jul 24 2021 - 00Z Mon Jul 26 2021 ...Heavy Monsoonal rainfall continues in the Desert Southwest, creating significant concern for flash flooding and excessive rainfall throughout the weekend... ...Severe thunderstorms possible from the Northern Plains to the Upper Great Lakes through Sunday morning... ...There is an Elevated Risk of Fire Weather for portions of the Northern High Plains, Northern Rockies, and Northern Great Basin through Saturday morning... During the short-range period all eyes will be on the Desert Southwest, where monsoon driven heavy rainfall is forecast to persist throughout the weekend. An upper-level low retrograding over the Texas/New Mexico border will aid in ushering highly anomalous moisture into the region as well as provide strong forcing for ascent, thus providing ingredients that could allow developing storms to produce high rainfall rates from 1-2"/hr and widespread accumulations of 2-4+". These rates combined with the antecedent saturated soils and numerous burn scars scattered throughout the area will be a significant cause of concern for widespread flash flooding events. As such, the Weather Prediction Center has issued a Moderate Risk for Excessive Rainfall for portions of Arizona and New Mexico that will be carried through Sunday morning. A Slight Risk for Excessive Rainfall is also in place for portions of southwest Utah, central New Mexico, and southwest/central Colorado where slow moving convection and strong upslope enhancement could produce heavy rain in some isolated areas. Flash Flood Watches are currently in effect for much of Arizona and the aforementioned regions. Meanwhile, a cold front extending from the Upper Midwest through the Northern Plains is expected to slowly propagate to the south and east through the Great Lakes before reaching the Central Appalachians by Sunday evening. Showers and thunderstorms are forecast to develop along and ahead of the front, leaving behind light to moderate rainfall totals. Moderate forcing and instability along the front will allow for some severe thunderstorms with damaging winds and large hail to develop. The Storm Prediction Center has issued a Slight Risk for severe thunderstorms from the central Dakotas to the western edge of Lake Superior. As the front progresses east into the Great Lakes the severe thunderstorm risk is forecast to shift east as well. From Saturday into Sunday morning severe thunderstorms will likely develop over portions of Michigan and coastal areas around southern Lake Michigan that could produce damaging winds, large hail, and an isolated tornado or two. Elsewhere, an Elevated Risk for fire weather is in effect for portions of the Northern High Plains, Northern Rockies, and Northern Great Basin through Saturday morning. Drought conditions, gusty winds, and dry fuels will aid in producing conditions favorable for the development and/or spread of wildfires. Red Flag Warnings are currently in effect for much of Montana and portions of Idaho. Off the southeastern coast, an area of low pressure and its associated stationary boundary will be the focus for showers and thunderstorms over Florida and its adjacent states through Sunday. The low pressure area itself is currently under watch by the National Hurricane Center and may develop into a tropical depression over the next couple of days. Temperature-wise much of the country will experience temperatures at or close to normal. An exception to this rule will be the Desert Southwest, which will experience moderately below normal temperatures due to the increased cloud cover from monsoonal activity keeping temperatures unseasonably cool. Conversely, portions of the Central Plains and Upper/Middle Mississippi Valley will experience temperatures 5 to 10 degrees above normal on Saturday, with daily highs reaching the mid 90s. Heat Advisories are currently in effect for potions of the Middle Mississippi Valley and eastern Central Plains while an Excessive Heat Warning is in effect for the Kansas City metro area. On Sunday, above normal temperatures will be felt in northern California and the Northern Great Basin, where daily highs are forecast to hit the high 90s and low 100s. Zavadoff Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php