US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 459 PM EDT Mon Aug 31 2020 Valid Thursday September 03 2020 - Monday September 07 2020 Hazards: - Flooding occurring or imminent across portions of the Lower Mississippi Valley. - Excessive heat across portions of the Southern Plains, Thu, Sep 3. - Much above normal temperatures across portions of California, the Great Basin, the Pacific Northwest, and the Northern Rockies, Fri-Mon, Sep 4-Sep 7. - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Sat-Mon, Sep 5-Sep 7. Detailed Summary: A front pushing southward over the plains on Thursday will move to the East Coast by Friday and into the Gulf of Mexico by Saturday. While moisture pooling along the front will high initially the moisture decrease on Thursday and with model uncertainty of how much rain will fall along the front WPC choose not to depict a heavy rain on the hazards map from the Southern Plains into the Ohio Valley on Thursday and Friday. In addition, by Sunday and Monday there is also too much model uncertainty to depict an area of heavy rain over parts of the Upper Great Lakes into the Middle Mississippi Valley. Meanwhile, upper-level ridging over the Northwest will aid in allowing the temperatures to be 12 degrees above normal so an area of much above normal temperatures will be depicted there on Friday into Monday. In contrast temperatures will become much colder over the Plains on Monday and extend beyond the day seven time frame. With temperatures forecast to be in the 90's to near 100 and dew points in the low 70's an excessive heat is depicted over parts of the Southern Plains. Over Alaska an area of deep low pressure will develop over the North Pacific and an associated plume of moisture will move into the Gulf of Alaska and the mainland coast that will produce an area of heavy rain over Kodiak Island and the Kenal Peninsula, on Saturday, that will expand into parts of the Alaska Panhandle late Saturday into Monday. Ziegenfelder