Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 AM EDT Sat Jun 21 2025 Valid 12Z Sat Jun 21 2025 - 12Z Mon Jun 23 2025 ...There is a Slight Risk of severe thunderstorms over parts of the Great Lakes today, then Upper Midwest and Northern/Central Plains on Sunday... ...Excessive Rainfall concerns emerge over the Southern High Plains on Sunday... ...Major to Extreme Heat Risk likely to expand from Central to Eastern U.S.... ...There is a Critical Risk of fire weather over parts of the Great Basin/Four Corners today... Shortwave energy riding over top of an upper ridge will produce scattered to isolated thunderstorms across the Great Lakes, interior Northeast and Upper Midwest today. The Storm Prediction Center issued a Slight Risk (level 2/5) of severe thunderstorms for portions of northeastern Wisconsin through the UP of Michigan today and into upstate New York and New England late tonight. A complex of storms, which originated in North Dakota Friday night, will move through the aforementioned areas. Some localized flash flooding is possible from these storms. Elsewhere, dryline storms could produce some scattered to isolated flash flooding over parts of eastern New Mexico and western Texas on Sunday. A Slight Risk (at least 15%) of excessive rainfall leading to flash flooding is in effect for those areas early next week. Troughing in the West will generate well below average temperatures across the region this weekend. Frost advisories and freeze warnings are in effect for parts northern California and northeastern Nevada respectively for tonight. The low temperatures and shallow Pacific moisture available will produce some minor to moderately impactful snowfall over the higher elevations of the Northern Rockies through Sunday. There is a Critical Risk of fires as well as Red Flag Warnings due to dry and windy conditions in parts of the Great Basin and Four Corners region today. A strong upper ridge is emerging over the Eastern half of the country. Widespread record max and min temperatures are likely to be tied/broken from the Upper/Middle Mississippi Valley to the Northeast/Mid-Atlantic over the next several days. Major to Extreme heat risk will spread into the Midwest and East Coast on Sunday, where anyone without effective cooling and/or adequate hydration will be affected. Little to no overnight relief will only exacerbate heat impacts. Kebede Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php