US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 313 PM EST Fri Jan 31 2020 Valid Monday February 03 2020 - Friday February 07 2020 Hazards: - Heavy precipitation across portions of the Pacific Northwest and the Northern Great Basin, Tue-Fri, Feb 4-Feb 7. - Heavy rain across portions of the Lower/Middle Mississippi Valley, the Southern/Central Appalachians, the Tennessee Valley, the Ohio Valley, the Southeast, and the Mid-Atlantic, Tue-Thu, Feb 4-Feb 6. - Heavy snow across portions of the Rockies, the Central/Northern Great Basin, and the Central/Northern Plains, Mon, Feb 3. - Heavy snow across portions of the Northern Rockies and the Northern Great Basin, Tue-Fri, Feb 4-Feb 7. - Heavy snow across portions of the Central/Northern Rockies, the Central/Northern Great Basin, and the Northern Plains, Wed-Fri, Feb 5-Feb 7. - Heavy snow across portions of the Central Rockies, Thu-Fri, Feb 6-Feb 7. - Severe weather across portions of the Lower Mississippi Valley and the Southern Plains, Tue, Feb 4. - Severe weather across portions of the Southeast, the Lower Mississippi Valley, the Southern Plains, and the Tennessee Valley, Wed, Feb 5. - Severe weather across portions of the Southeast, the Mid-Atlantic, the Southern Appalachians, and the Tennessee Valley, Thu, Feb 6. - Flooding occurring or imminent across portions of the Lower Mississippi Valley and the Northern Plains. - Flooding likely across portions of the Pacific Northwest and the Northern Great Basin. - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Mon-Thu, Feb 3-Feb 6. - Much below normal temperatures across portions of mainland Alaska, Mon, Feb 3. - Much below normal temperatures across portions of mainland Alaska, Thu-Fri, Feb 6-Feb 7. - High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Mon, Feb 3. Detailed Summary: The beginning of the medium range period (Monday) will feature upper-level ridging in the eastern half of the U.S., as a potent upper-level trough takes shape over the Great Basin. This trough is forecast to make its way eastward across the U.S. during the period and create some hazardous weather. First, a round of heavy snow is expected to fall in higher elevations of the Rockies and Wasatch early next week given the strength of the upper-level energy. As the trough moves east, moisture from the Gulf should return to the southeastern quadrant of the U.S. ahead of it, and with the upper-level support from the strong jet stream, severe weather and heavy rain are both forecast. These threats should move west to east ahead of the trough and along its associated surface cold front Tuesday through Thursday, with some precipitation falling north along the Eastern Seaboard Friday before exiting. The northern edge of the precipitation (from the Central Plains to Midwest and into the Great Lakes region and interior New England) could be wintry, but snowfall amounts are too uncertain at this time to warrant drawing a heavy snow hazard area. Onshore flow with moisture from the Pacific will increase in the Pacific Northwest midweek, leading to heavy mountain snow and lower elevation rain there. Some moisture is expected to make its way into the Northern and Central Rockies, so another round of heavy snow is forecast for higher elevations there later next week. Temperatures across the U.S. will be warm underneath the upper ridge, with much above normal temperatures present across the Southern Plains all the way to the Northeast on Monday, persisting across the eastern U.S. into Wednesday and Thursday. This time of year, this is not usually hazardous, so did not delineate a hazard area. Then temperatures should swing to colder than average underneath the upper trough, with cooler temperatures in the West by Monday and moving into the Central/Southern Plains by Tuesday and Wednesday. Minimum temperatures are not forecast to be significantly below average for a long period of time, however. Over Alaska, one more day of colder than average temperatures is forecast over the eastern part of the mainland on Monday. Meanwhile, warmer than normal temperatures are expected in the southwestern mainland, spreading eastward on Tuesday and Wednesday. Then, an upper-level low could settle near the northwestern portion of the state; while there is uncertainty in the model guidance as to where exactly this upper low will be centered, the pattern could lead to below normal temperatures for the Seward Peninsula and the North Slope later in the week. At the surface, a deep low pressure system tracking near the Aleutians could produce a period of significant waves there on Monday. Persistent moisture coming into the Alaska Panhandle will lead to heavy precipitation through Thursday, with amounts lessening by the end of the week. Tate