US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 248 PM EDT Mon Sep 16 2019 Valid Thursday September 19 2019 - Monday September 23 2019 Hazards: - Heavy rain across portions of the Southern Plains, Thu-Fri, Sep 19-Sep 20. - Heavy rain across portions of the Central Plains, the Lower Mississippi Valley, the Southern Plains, the Middle Mississippi Valley, the Great Lakes, and the Ohio Valley, Sat-Sun, Sep 21-Sep 22. - Heavy rain across portions of the Central Plains, the Upper Mississippi Valley, and the Northern Plains, Fri-Sat, Sep 20-Sep 21. - Severe weather across portions of the Upper Mississippi Valley and the Northern Plains, Fri, Sep 20. - Flooding possible across portions of the Central Plains, the Lower Mississippi Valley, the Northern Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Southern Plains. - Flooding occurring or imminent across portions of the Central Plains, the Middle Mississippi Valley, the Great Lakes, the Upper Mississippi Valley, and the Northern Plains. - Flooding likely across portions of the Central Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Northern Plains. - Much below normal temperatures across portions of the Central Great Basin, the Northern Rockies, the Central Rockies, California, the Northern Great Basin, and the Pacific Northwest, Thu-Sat, Sep 19-Sep 21. - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Fri-Sat, Sep 20-Sep 21. Detailed Summary: The medium range period (Thursday to Monday) will start with upper-level troughing in the western U.S. and upper-level ridging in the eastern U.S., turning more zonal by the end of the period. With the forecast pattern, several heavy rain areas will be possible across the central U.S. The first area of concern is across the western Gulf Coast and Southern Plains. A weak area of low pressure with an abundant amount of tropical moisture is forecast to very slowly move across eastern Texas on Thursday and possibly enter Oklahoma by Friday. After dumping several inches of rain before Thursday, another 2 to 4 inches will be possible by the end of the week and could exacerbate flood concerns across coastal Texas. Meanwhile, a strengthening low pressure system is forecast to be found across the Northern Plains on Friday. This system, combined with above average temperatures in the Upper Midwest, could spawn severe thunderstorms and heavy rain for Minnesota and the eastern Dakotas on Friday and Saturday. A cold front associated with the aforementioned low pressure system is then forecast to reach the Midwest and Central Plains by Saturday and Sunday. The interaction of the cold front and tropical moisture could lead to showers and thunderstorms capable of producing 1 inch or more of rain, specifically across eastern Kansas and Missouri this weekend. The upper-level trough across the western U.S. will aid in producing much below average temperatures from the central Great Basin to the Northern Rockies. Minimum temperatures in these areas are forecast to be around 5 to 10 degrees below average, which would normally not be enough to include on the hazards chart. However, frost/freeze concerns led to the placement of the area today. New England is forecast to start the medium range period with slightly below average temperatures as well, with average-to-above average temperature found elsewhere across the country. The highest temperature anomalies (around 10 to 15 degrees above normal) can be expected across the Midwest through Thursday and into the Northeast this weekend. A much above average temperature area was not drawn for these regions due to high temperatures only expected to reach the 80s and not considered hazardous for this time of year. In Alaska, an active and wet pattern is expected to continue during the medium-range period. A potent low pressure system is forecast to bring heavy rain to southern Alaska, as well as the Alaskan Panhandle. Total rainfall amounts of 2 to 4 inches will be possible on Friday and Saturday, with locally higher amounts. Another round of heavy rain will be possible on Monday over the same region, but enough uncertainty exists to leave it out of today's hazard graphic. Snell