Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 311 PM EDT Tue Jul 04 2023 Valid 00Z Wed Jul 05 2023 - 00Z Fri Jul 07 2023 ...Well above-normal to record-breaking heat expected for portions of the Pacific Northwest... ...Strong to severe storms likely for portions of the Northern/Central Plains and into the Midwest; Critical Fire Risk over northern Arizona tonight... ...Heavy to excessive rainfall leading to flash flooding possible from Northern/Central Plains into Upper Midwest as well as Northeast tonight... On this 4th of July, the northern High Plains will likely be the area having the best chance of seeing some natural fireworks, thanks to a rather strong intrusion of cool air from Canada for this time of the year. Locally heavy rain along with strong to possibly severe thunderstorms are expected to develop behind the cold front that marks the boundary of the cool air mass. By later today and into tonight, the axis of heavy rain/storms will progress farther south toward the Central Plains. By Wednesday into early on Thursday, the threat of strong thunderstorms should lessen as they shift farther east across the upper Midwest into the Great Lakes. Periods of rain and embedded thunderstorms can also be expected along the eastern slopes of the Northern and Central Rockies through the next couple of days as the cool air will be forced to lift along the terrain behind the cold front. Meanwhile, a drastic cool down ensures behind the front with record cool day-time temperatures possible in Wyoming on Wednesday. In the West, temperatures are expected to remain above normal along much of the West Coast into the southwestern U.S., with some record high temperatures possible for portions of western Oregon on Wednesday. With temperatures likely to climb to their highest of the season so far, Heat Advisories are in effect for portions of western Oregon, interior counties of far northern California, central New Mexico, Texas Florida and coastal Carolinas. Heat Advisories are currently in effect for over 30 million people. Meanwhile, with another day of temperatures climbing well in excess of 110F, Excessive Heat Warnings remain in effect across the lower deserts of Arizona and southeastern California. Dry, hot and windy conditions will support a Critical Fire Weather risk over much of northern Arizona through tonight. Seasonal to above-average temperatures will continue across the southern Plains and through much of the eastern U.S. More typical summertime scattered thunderstorms are expected to linger across the southern tier states. Meanwhile, a low pressure wave moving across New England will weaken further and become diffused over the next couple of days. Much of the Northeast and the Mid-Atlantic will see decreasing rain chances over the next couple of days especially over New England, although some isolated thunderstorms could still produce locally heavy rain in these areas. Kebede/Kong Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php