Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 450 PM EDT Sun Jun 28 2020 Valid 00Z Mon Jun 29 2020 - 00Z Wed Jul 01 2020 ...Scattered thunderstorms could become severe across parts of the northern Plains, the Carolinas and Northeast through this evening, with flash flooding possible for parts of the Midwest... ...Locally heavy precipitation likely over the Northwest along with colder temperatures, while fire danger is expected for the Central Great Basin and Southwest... ...Saharan dust continues to linger across Florida; some of the dust is expected to spread into the Great Plains and the East Coast... A cold front is forecast to slowly move southward down the East Seaboard during the next couple of days as the trailing end of the front remains nearly stationary across the Ohio Valley and Midwest. This will favor bouts of scattered thunderstorms to move from the upper Midwest across the lower Ohio Valley toward the southern Appalachians into Tuesday. Severe weather and flash flooding can also be expected for parts of these areas. In addition, severe weather is possible across southern New England through this evening as a low pressure system slowly develops both at the surface and aloft. Meanwhile, a large upper-level low is forecast to settle into much of the western U.S. during the next few days. This will bring a surge of unseasonably cool to cold temperatures through the western U.S. where high temperatures of 15 to more than 30 degrees below average are forecast. The upper low will also bring widespread precipitation into the Northwest where elevation-enhanced rain totals of 1 to 3 inches likely in the northern Rockies. Wet snow is even possible for higher elevations of the northern Rockies as temperatures drop to near freezing during the next couple of nights. In fact, up to a foot of snow is possible near the peaks of the Bitterroot mountains in Idaho. By Tuesday morning, wet snow is forecast to reach the Yellowstone National Park, the higher elevations of northern Utah, and as far south as the Colorado Rockies as the cold air mass continues to plunge southward through the southern Rockies. As the cold air plunges southward through the western U.S., an elongated low pressure system is forecast to gradually intensify across the Great Plains. The chance of strong to severe thunderstorms should increase over the northern Plains on Tuesday as the upper low begins to lift and exit the northern Rockies. Meanwhile, a low pressure center is forecast to be consolidating over the central Plains. Although the dynamics associated with this system appears strong, the injection of the Saharan dust from the Gulf Coast into the system may suppress the heavy rain and thunderstorm activities across the southern Plains on Tuesday. Meanwhile, widespread Red Flag Warnings and Critical Risks of fire weather are in effect for parts of California, the central Great Basin, and the Southwest due to gusty winds and low humidity. A significant amount of the Saharan dust is forecast to linger over Florida for the next few days as another dust plume from the Sahara could reach the western Gulf Coast by Tuesday. The main impacts of the Saharan dust will be hazy skies during the day, locally reduced visibility, degraded air quality, but with very colorful sunrises and sunsets. Some of the dust is forecast to spread up the Plains states ahead of the western U.S. upper low, while some is expected to spread eastward into the Southeast and the Mid-Atlantic. In the meantime, temperatures over Florida will remain hotter than normal, and could even set records with highs in the upper 90s. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php