Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Wed Sep 27 2017 Valid 00Z Thu Sep 28 2017 - 00Z Sat Sep 30 2017 ...Heavy rain possible for Southern Rockies and Southern Plains with moderate risk of flash flooding for South Central Texas... Copious amounts of moisture are present over the Southern Plains, and that plus a stationary front is leading to heavy rainfall there. The highest rainfall amounts are expected across the border in Mexico, but areas near the border in the Edwards Plateau of Texas could see an additional 2 inches of rain. There is a moderate risk of flash flooding through Thursday morning in that area where lots of rain has already fallen. Slight risks of flash flooding are in effect elsewhere in the Southern Plains and Southern Rockies. Rain will continue in those areas through the end of the workweek. In the Central Rockies, temperatures will be cold enough to support snow in the higher elevations on Wednesday and Thursday nights. A cold front stretching from the Lower Great Lakes into the Ohio Valley and Lower Mississippi Valley will lead to a few showers and thunderstorms Wednesday night for the Lower Great Lakes and Northeast. This will also usher in cooler temperatures for these areas after the much above average temperatures from the past few days. This front will continue eastward and southward, moving offshore of the Northeast and Mid-Atlantic by Thursday afternoon. This front and its associated upper-level trough will help steer Hurricane Maria quickly eastward as it weakens to a tropical storm. See the National Hurricane Center's forecast for more information on Maria. A low pressure system will approach the Upper Great Lakes on Thursday, bringing showers to that area and into the Lower Great Lakes by Friday afternoon. Another low will bring rain to the Pacific Northwest on Friday. Tate Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php