US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 239 PM EST Tue Feb 23 2021 Valid Friday February 26 2021 - Tuesday March 02 2021 Hazards: - Heavy rain across portions of the Lower Mississippi Valley, the Central Appalachians, the Tennessee Valley, the Middle Mississippi Valley, the Mid-Atlantic, the Southern Appalachians, the Southeast, the Southern Plains, and the Ohio Valley, Fri-Tue, Feb 26-Mar 2. - Heavy snow across portions of the Pacific Northwest, the Northern Rockies, the Northern Great Basin, and the Northern Plains, Fri, Feb 26. - Flooding occurring or imminent across portions of the Southeast, the Mid-Atlantic, and the Pacific Northwest. - Flooding likely across portions of the Southeast. - High winds across portions of the Central Plains, the Central Great Basin, the Northern Plains, the Northern Rockies, the Central Rockies, the Northern Great Basin, and the Pacific Northwest, Fri, Feb 26. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat-Sun, Feb 27-Feb 28. - High winds across portions of mainland Alaska and the Aleutians, Mon-Tue, Mar 1-Mar 2. - High winds across portions of the Aleutians, Sun-Tue, Feb 28-Mar 2. - Much above normal temperatures across portions of mainland Alaska, Fri-Sat, Feb 26-Feb 27. Detailed Summary: The medium range period (Friday, February 26 - Tuesday, March 2) will feature periods of upper-level troughing generally located over the western half of the U.S., with an upper-level high over the Gulf of Mexico and Caribbean. This pattern should lead to moist and relatively warm air flowing from the Gulf of Mexico into the eastern half of the CONUS. A couple of fronts with waves of low pressure along them are expected to provide areas for this moisture to focus, leading to a couple of rounds of moderate to potentially heavy rain. The current forecast shows rain on Friday across portions of the Lower Mississippi Valley, Southeast, and into the Tennessee Valley. Then another round begins by Saturday as moisture increases and lasts all the way into Tuesday, with rain spreading slightly northward into the Ohio Valley at times as well. Timing and location uncertainties were still relatively high today, which kept the Heavy Rain area from being separated spatially or temporally on the Hazards graphic. This means every location may not see heavy rain each day. Over the entire 5-day period, maximum rainfall amounts of 4 to 8 inches will be possible from central Arkansas to eastern Kentucky and Tennessee. Much of the highlighted area has experienced a rather dry stretch as of late, with Kentucky and West Virginia being the only widespread exceptions. By Tuesday it's possible the heavy rain axis shifts south and into the Southeast before finally exiting the region. Light wintry precipitation could occur north of the heavy rain axis, but no major impacts are expected. In the West, heavy snow is possible particularly for the Cascades and Northern Rockies for the latter part of the workweek as a frontal system passes through. Slightly lower but potentially impactful snow amounts are expected for the Wind River Mountains/Tetons toward the Wasatch and Central Rockies. Gusty winds are also possible for the Northern Great Basin, Northern High Plains, and the Rockies in between on Friday. This could make travel difficult for high profile vehicles in areas susceptible to crosswinds. Precipitation could once again increase in the Northwest early next week, but amounts do not seem terribly high. With the aforementioned troughing across the West, somewhat below normal temperatures are forecast for the Great Basin, Rockies, and portions of the Plains. High temperatures could be 10 to 20 degrees below normal across the Northern Plains and Northern Rockies on Friday. Temperatures will likely be warmer than normal across the Southeast and Gulf Coast States for the entire forecast period. Highs in the 60s and 70s (80s in Florida) will produce an early taste of spring for the region. For Alaska, a surface low pressure system is forecast to move across the Bering Sea and produce some precipitation and gusty winds over the Aleutians and western Alaska on Friday. However, heavier amounts of precipitation are expected for South-central Alaska into the Panhandle as the low pressure system reforms in that area Saturday into Sunday. Most of the heavy precipitation is likely on Saturday, but should linger across the southeastern Panhandle on Sunday. Across the southwestern mainland, a period of upper-level ridging centered around Friday could cause much above normal temperatures, which could be hazardous as temperatures may rise above freezing. Then, another frontal system is forecast to track across the Aleutians early next week, which could lead to gusty winds and some precipitation there, as well as high waves offshore. Snell