Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 256 PM EDT Thu Sep 19 2019 Valid 00Z Fri Sep 20 2019 - 00Z Sun Sep 22 2019 ...Tropical Depression Imelda continues to produce extreme rainfall and flooding in parts of southeast Texas... ...Severe thunderstorms and flash flooding possible in the northern and central Plains on Friday and Saturday... Tropical Depression Imelda continues to drift across eastern Texas, and has produced extreme rainfall over the past couple days in southeast parts of the state. Dangerous flash flooding is ongoing today across southeast Texas and adjacent parts of far southwest Louisiana. A High Risk of excessive rainfall and flash flooding remains in effect for those areas. Please refer to the Excessive Rainfall Outlook and National Weather Service warning and watch products for the latest information. Meanwhile, a low pressure system will make gradual progress from the Intermountain West, to the northern Plains, to Ontario over the next several days, and an associated cold front will push into the Plains on Friday and Friday Night. This front should lead to thunderstorms in the northern and central Plains from Friday into Saturday. Some of the storms could be severe, with large hail and damaging winds the primary threats. Flash flooding will also be possible, especially on Saturday and Saturday Night in portions of the central Plains as the front begins to interact with lingering moisture from Imelda. Rainfall amounts in excess of 3 inches are forecast from northeast Kansas into northern Missouri. Colder air will push into the western states behind the cold front, and this is expected to lead to some accumulating snow in the higher elevations of the interior Northwest, particularly in Idaho, Montana and Wyoming above 8000 feet elevation. High temperatures will be as much as 15-25 degrees below average in these areas. Ahead of the cold front, high temperatures will be above average in the Plains and Central U.S., with the warmth spreading to the East Coast this weekend. Temperatures will be most above average in the Great Lakes, with highs into the 80s and lows in the mid to upper 60s on a widespread basis. Those temperatures are more typical of average conditions in mid-summer in the region. Lamers Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php