Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 318 AM EDT Wed Sep 19 2018 Valid 12Z Wed Sep 19 2018 - 12Z Fri Sep 21 2018 ...Heavy rain for parts of the Southwest U.S. and the Upper Midwest with above normal temperatures continuing for the eastern half of the nation through Thursday... The weather pattern through the middle to end of the week will be featured with an upper level trough crossing the western third of the U.S. and a broad subtropical ridge over the central and eastern U.S. with a couple of frontal boundaries situated from the Rockies to the Ohio Valley. A developing surface low over the central plains Wednesday night and into Thursday is forecast to result in moderate to heavy rainfall extending from eastern South Dakota to the Upper Peninsula of Michigan through Thursday night. The potential exists for 2 to locally 4 inches of rainfall across parts of this region, and this area will be monitored for the potential for flash flooding. A second area at risk for enhanced rainfall will be across southern Arizona and New Mexico as deep tropical moisture surges northward from western Mexico in association with an area of disturbed weather, and the National Hurricane Center is monitoring this for possible tropical development. In any case, monsoon-like rainfall can be expected for this area along with possible flooding in flood prone areas. Elsewhere across the western U.S., rain is also likely across Montana on Thursday behind the cold front, with even some snow possible across the highest elevations of the northern Rockies. Dry and breezy conditions are expected for Utah and into southern Wyoming with an elevated wildfire potential. Temperatures are expected to be on the order of 5 to 15 degrees above normal from the Midwest to the Ohio Valley and extending south to the Gulf Coast, with highs well into the 80s and even lower 90s. Much cooler conditions should reside northwest of the front from Montana to Minnesota with highs in the upper 40s to near 60 degrees, and this is 10 to 20 degrees below mid-September averages. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php