US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 343 PM EST Thu Mar 07 2019 Valid Sunday March 10 2019 - Thursday March 14 2019 Hazards: - Heavy precipitation across portions of the Northeast, Sun, Mar 10. - Heavy rain across portions of the Central Plains, the Mississippi Valley, and the Southern Plains, Mon-Tue, Mar 11-Mar 12. - Heavy rain across portions of the Lower/Middle Mississippi Valley, the Tennessee Valley, the Southeast, and the Southern/Central Appalachians, Wed-Thu, Mar 13-Mar 14. - Heavy precipitation across portions of the Central Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Northern Plains, Mon-Wed, Mar 11-Mar 13. - Heavy snow across portions of the Central/Northern Plains, the Great Lakes, and the Upper Mississippi Valley, Mon-Wed, Mar 11-Mar 13. - Heavy snow across portions of the Pacific Northwest and the Northern Great Basin, Mon-Tue, Mar 11-Mar 12. - Heavy snow across portions of the Southern Rockies, the Central Rockies, and the Central Great Basin, Mon-Thu, Mar 11-Mar 14. - Severe weather across portions of the Southeast, the Mid-Atlantic, the Lower Mississippi Valley, the Southern Appalachians, and the Tennessee Valley, Sun, Mar 10. - Flooding possible across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, and the Upper Mississippi Valley. - Flooding occurring or imminent across portions of the Southeast, the Middle Mississippi Valley, the Lower Mississippi Valley, the Ohio Valley, and the Tennessee Valley. - Much below normal temperatures across portions of the Northern/Central Rockies, the Northern/Central Plains, and the Northern Great Basin, Sun-Mon, Mar 10-Mar 11. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun-Mon, Mar 10-Mar 11. - High winds across portions of the Alaska Panhandle and mainland Alaska, Sun, Mar 10. - High winds across portions of the Alaska Panhandle and mainland Alaska, Wed-Thu, Mar 13-Mar 14. - High winds across portions of mainland Alaska and the Aleutians, Sun-Mon, Mar 10-Mar 11. - High significant wave heights for coastal portions of the Alaska Panhandle and mainland Alaska, Thu, Mar 14. Detailed Summary: For the beginning of the medium range period (Sun-Mon), a low pressure system is forecast to track from the Upper Great Lakes region across southern Canada while a low along the associated fronts develops across New England. While most of the heavy snow across the Plains/Midwest from this storm is now in the short range period, heavy precipitation is expected in New England due to this developing low. In the warm sector, strong to severe thunderstorms are possible along the Central/Eastern Gulf Coast and into the Southeast/Carolinas. Additionally, gusty winds could linger across the Great Lakes region on Sun-Mon behind the low, but seem to be below criteria for High Winds at this time. Another low pressure system is expected to track through the Southwest on Mon-Tue and strengthen in the Plains on Wed, before moving into the Upper Great Lakes region on Thu. While this is a similar track to the aforementioned storm, one difference this time will be warmer temperatures in the Central Plains and the Upper/Middle Mississippi Valley--the Much Below Normal Temperatures are finally expected to lessen their hold across the north central U.S. after Mon-Tue. As such, mixed precipitation and freezing rain are likely farther north, and areas are likely to transition between rain and snow. Thus included much of the Plains/Mississippi Valley in a Heavy Precipitation area, with Heavy Snow in place on the northwestern side. In some areas of the Midwest, rain falling on the snowpack could be hazardous, as rapid melting of the snow is possible, which could cause flooding or the potential for ice jams. Farther south, this second low pressure system will be associated with increased moisture ahead of it. Heavy rain is currently forecast to focus in the Southern Plains on Mon and spread north by Tue into the Central Plains and Middle/Lower Mississippi Valley. As the front pushes eastward, the threat of heavy rain will move with it into the Tennessee Valley, Southeast, and Southern/Central Appalachians on Wed-Thu. The Tennessee Valley in particular has been anomalously wet over the last month or so, so flooding and flash flooding will be a concern there. Widespread thunderstorms, some severe, are expected. Meanwhile in the western CONUS, an upper-level trough will pass through the Pacific Northwest on Tue-Wed and cause the possibility for heavy snow in the Cascades. Snow is also possible in the Central Great Basin to Central/Southern Rockies as the aforementioned low pressure system moves through, with the heaviest snow likely in the higher elevations of the Central Rockies. An active pattern will remain in Alaska through the period, with a series of troughs coming through. The first hazards will be on Sun-Mon, with high winds possible across the Aleutians and northwestern Alaska, and heavy precipitation for the Panhandle. By Wed-Thu, high winds and significant waves are predicted, with heavy precipitation possible somewhere along southern Alaska and the Panhandle, though will wait for better model agreement to draw a hazard for Heavy Precipitation there. Tate