Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 415 AM EDT Sat Oct 26 2019 Valid 12Z Sat Oct 26 2019 - 12Z Mon Oct 28 2019 ...Heavy rain associated with a low pressure system is expected to spread rapidly northward from the central Gulf Coast toward the Great Lakes... ...A round of moderate to heavy snow is forecast for the northern and central Rockies as well as nearby High Plains... ...Severe thunderstorms possible today over the central Gulf Coast as post-tropical cyclone Olga makes landfall... Active weather is expected to spread rapidly northward from the Deep South into the Midwest today. This is the result of an energetic upper-level trough interacting with post-tropical cyclone Olga, which is ready to make landfall on the central Louisiana coast early this Saturday morning. A compact low pressure system is forecast to intensify as it moves rapidly up the Mississippi Valley today. Widespread rain is already impacting the Mississippi and Ohio Valleys well ahead of the storm center. As the center of Olga makes landfall across Louisiana early in the morning, a period of heavy downpour together with increasing winds as well as the possibility of severe thunderstorms is expected across eastern Louisiana as well as southern Mississippi. In addition, the heavy rainfall will increase the possibility of flash flooding in these areas. As the system intensifies and moves northward, heavy rain will become focused just to the west and northwest of the storm track, resulting in 2 to 3 inches of heavy rainfall along the Mid-Mississippi Valley today, followed by the Midwest this evening. By Sunday, the system is expected to weaken as it tracks across the Great Lakes into southeastern Canada. However, widespread rain will move into much of the East Coast where an inch of rain can be expected from the Mid-Atlantic up into New England before the cold front and a low pressure center move out to sea Sunday night. A surge of cold air from western Canada will push southward through much of the western U.S. over the next few days. This will be accompanied by a round of moderate to heavy snow for the northern and central Rockies as well as the nearby High Plains. Up to a foot of snow is forecast especially over the higher elevations. A cold high pressure system will then dominate much of the interior Northwest extending into the northern Plains through the weekend with well below normal temperatures. In contrast, milder than normal temperatures are expected along the East Coast even after the passage of a cold front on Sunday. Meanwhile, dry conditions will continue across the southwestern U.S. where fire danger will remain high at many locations. The most critical area to watch will be over parts of northern California. Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php