740 FXUS01 KWBC 261854 PMDSPD Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 253 PM EDT Fri Jun 26 2026 Valid 00Z Sat Jun 27 2026 - 00Z Mon Jun 29 2026 ...Numerous instances of flash flooding will remain a threat across the Ozarks vicinity today amongst a broader flash flood threat through the central/southern Plains to Ohio Valley through tomorrow... ...Scattered to widespread severe thunderstorms forecast tomorrow across portions of the northern Plains... ...Critical to Extremely Critical fire weather conditions continue over portions of the Intermountain West into the weekend... ...Heat begins to build over the South into Saturday before a more widespread expansion into the Plains on Sunday as a dangerous central to eastern U.S. heat wave begins... An amplifying pattern will bring a variety of weather hazards across the country heading into the weekend. Scattered to widespread thunderstorms continue to develop along a meandering frontal boundary from the central/southern Plains east through the Ohio/Tennessee Valleys and into the Carolinas/Mid-Atlantic today (Friday), and will continue into the weekend. Pooling moisture along the boundary will contribute to locally heavy downpours with repeated development/movement parallel to the boundary will support long-duration rainfall/high totals. There is a Moderate Risk of Excessive Rainfall (ERO) (level 3/4) today across portions of the MO/KS/AR/OK border region into the Ozarks where numerous instances of flash flooding can be expected. A Slight Risk (level 2/4) for more scattered to numerous instances of flash flooding extends westward over northern Oklahoma and eastward into the Middle Mississippi/Ohio Valleys. Sufficient instability and flow aloft will also bring the risk of a few more robust thunderstorms capable of severe weather, with the Storm Prediction Center (SPC) including a Slight Risk (level 2/5) for the threat of damaging winds and a few tornadoes. Another Slight Risk ERO is in place Saturday across portions of the Ohio/Tennessee Valleys where the risk for scattered flash flooding will continue. There is also a Slight Risk of severe weather for coastal North Carolina/the Virginia Tidewater as some damaging wind gusts will be possible. Scattered storm chances will remain in the forecast into Sunday but become increasingly less notable as an upper-ridge begins to build overhead. To the west, an unseasonably strong upper-trough has begun to dig into the western U.S. bringing much cooler, unsettled weather throughout the region. A leading upper-wave rounding the trough will lead to deep lee cyclogenesis and the development/reinforcement of a surface frontal system over the northern/central High Plains. Scattered thunderstorms are expected with the SPC maintaining a Slight Risk of severe weather mainly for some large hail and damaging wind gusts. Increasing upper-flow will bring a greater threat of severe weather Saturday with an Enhanced Risk (level 3/5) now in place for the threat of very large hail and significant damaging wind gusts. The threat will spread further eastward into the Upper Midwest Sunday with another Slight Risk in place. Locally heavy rainfall and flash flooding will also be a concern and a Slight Risk ERO is in place for portions of the northern Plains near the Canadian border Saturday. Additional showers and thunderstorms are forecast throughout the Pacific Northwest and into the northern Great Basin/Rockies under the deepening upper-trough into the weekend. Forecast high temperatures are upwards of 25-35 degrees below average, with mostly 60s throughout the Pacific Northwest/coastal California and Interior West, with 80s through central California and 90s to low 100s in the Desert Southwest. The unseasonably cool nature of the pattern will even bring some moderate to heavy snow (4-8"+ accumulations) to portions of the northern Rockies, generally above 6500 feet. In addition, a dangerous fire weather pattern will continue over portions of the Great Basin and Four Corners Region where the SPC has outlooked an Extremely Critical Risk of fire weather (level 3/3) today with at least a Critical Fire Risk remaining in place both Saturday and Sunday. Gusty winds with the incoming trough, extremely low humidity, and very dry antecedent conditions/fuels will contribute to rapid growth of ongoing fires and the high threat of additional developing fires. Meanwhile, an upper-level ridge will begin to build first over the southeastern U.S. before expanding more broadly over the central to eastern U.S. this weekend and into early next week. The combination of high temperatures in the 90s to low 100s and increasing humidity across the southern Plains/Southeast will lead to expanding areas of Moderate to Major HeatRisk (levels 2/3 of 4), levels of heat that begin to become a threat to anyone without adequate access to air conditioning/hydration. Then, as the ridge expands on Sunday, Moderate to Major HeatRisk will spread northward across portions of the Plains and Missouri/Mississippi Valleys. Unfortunately, this will only be the start of an expected widespread, long-duration, and dangerous heatwave heading into the week before the July 4th Holiday. Temperatures will be slower to increase north of the frontal boundary across the Great Lakes/Ohio Valley into the Northeast, where more pleasant below to around average highs in the 70s and 80s are expected this weekend, ahead of the heat into next week. Please see WPC's heat key messages for more details especially beyond the current short-range forecast period. Elsewhere, scattered thunderstorm chances are forecast over the southern High Plains and Florida the next couple of days. Some showers and thunderstorms will remain possible across New England into Friday night. Putnam Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php $$