US Day 3-7 Hazards Outlook NWS Weather Prediction Center College Park MD 333 PM EDT Wed Jul 10 2019 Valid Saturday July 13 2019 - Wednesday July 17 2019 Hazards: - Heavy rain across portions of the Lower Mississippi Valley, the Tennessee Valley, the Middle Mississippi Valley, the Southeast, the Southern Plains, and the Ohio Valley, Sat-Wed, Jul 13-Jul 17. - Flooding possible across portions of the Central Plains and the Northern Plains. - Flooding occurring or imminent across portions of the Central Plains, the Lower Mississippi Valley, the Northern Plains, the Middle Mississippi Valley, the Upper Mississippi Valley, and the Ohio Valley. - Flooding likely across portions of the Central Plains and the Northern Plains. - Excessive heat across portions of California and the Southwest, Sat-Tue, Jul 13-Jul 16. - High winds across portions of the Lower Mississippi Valley, Sat-Sun, Jul 13-Jul 14. Detailed Summary: Overall, upper-level ridging across the central and eastern United States will lead to a relatively quiet pattern over most of the country. The exception will be a tropical cyclone forming in the Gulf of Mexico and impacting the Lower Mississippi Valley. This Potential Tropical Cyclone Two is currently forecast to move slowly westward through the northern Gulf of Mexico by Friday, then track northward towards coastal Louisiana and/or eastern Texas by the weekend before continuing northward into the Lower Mississippi Valley early next week. Plenty of uncertainty remains as to the exact track and the intensity of this system, as model guidance does not provide a perfect consensus yet. Regardless of development, this low pressure system is expected to cause extremely heavy rainfall in the western and central Gulf Coast states, as well as inland across the Lower Mississippi Valley. Rainfall amounts of 6 to 12 inches are expected near and inland of the central Gulf Coast through early next week, with isolated maximum amounts around 18 inches. High Winds will also be likely across coastal Louisiana Saturday and Sunday. Be sure to go to www.nhc.noaa.gov for official tropical cyclone forecasts. The other area of concern for heavy rain will be across the Northern Plains and Upper Midwest by Wednesday, July 17. Thunderstorms will be possible along a stalled frontal boundary and could lead to rainfall amounts greater than one inch, but uncertainty remains with the placement of the heaviest rain, as well as if amounts will actually add up to over an inch. Heat is expected underneath the upper-level ridging across the Southwest from Saturday to Tuesday. High temperatures around 115 degrees plus above average overnight lows necessitated placing a hazard area there. An Excessive Heat area was considered across the Mid-Atlantic (specifically eastern Virginia and North Carolina) as heat indices could approach 105-110 degrees on Sunday and again by Wednesday. However, since the heat appears short lived on Sunday and there is rather large uncertainty on Wednesday, an area was not added. No weather hazards are forecast for Alaska during this period. Snell