Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 322 AM EDT Sat Jul 25 2020 Valid 12Z Sat Jul 25 2020 - 12Z Mon Jul 27 2020 ...Hanna expected to become a hurricane and produce heavy rainfall for western Gulf Coast this weekend... ...Heavy Rainfall/flash flooding possible for parts of the Southwest, Rockies, and the Northern and Central Plains over the next few days... ...Cooler temperatures to return to the West... Tropical Storm Hanna continues to strengthen as it approaches South Texas and should achieve hurricane status by landfall. Per the National Hurricane Center's latest forecast, Hanna is expected to make landfall late Saturday afternoon/early evening. Strong winds and heavy rain -- with amounts of 2-3" an hour at its most intense -- will accompany the storm along and near its path through the weekend into Monday morning. Localized heavy rain will lead to flash flooding, in addition to possible minor to moderate river flooding, with local amounts up to 18" expected; South Texas has a rare High Risk of excessive rainfall from Hanna Saturday into Sunday morning. A slight risk of severe thunderstorms also exists in the vicinity of Hanna. For more information on Hanna's cyclone status and expected track, see advisories from the National Hurricane Center. Areas of locally heavy rain can be expected this weekend into Monday across portions of the West. Monsoonal moisture will be most impactful on Saturday across Arizona and the Four Corners (Slight Risk of excessive rainfall) before the risk of heavy/excessive rainfall shifts east farther into Colorado and New Mexico Sunday and Monday. Rainfall rates may be heavy at times, particularly in the afternoon and evening hours. Otherwise, much of the western U.S. can expect cooler than normal conditions with the upper-level trough in place. The ridge over much of the central U.S. while keep temperatures much above average Saturday from the Northern Plains to the Upper Midwest. Thereafter, a pair of low pressure systems drop a cold front into the Plains which directs monsoonal moisture to fuel strong, organized thunderstorm activity around the ridge top on a more southerly trajectory each day. The risk of excessive rainfall is highest across the Upper Mississippi Valley Saturday and Saturday night (Marginal), the Central Plains into the Midwest Sunday into Sunday night (as high as Moderate), and portions of the Southern and Central Plains Monday (Slight). Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php