Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 119 PM EDT Sun Jul 15 2018 Valid 00Z Mon Jul 16 2018 - 00Z Wed Jul 18 2018 ...Heavy rain possible over the Southwest and Southeast... ...Cooler air moving into the Great Lakes and Northeast Monday into Wednesday... Shower and thunderstorm development is expected to be a daily occurrence from the central Plains into the Southeast near the southern edge of the Westerlies, which is in the vicinity of surface fronts and troughs of surface low pressure through Tuesday. Because of moisture levels being above average for July, low temperatures could reach record warm values across large portions of the Southeast and Mid-Atlantic states on Tuesday. The warm overnight lows have prompted heat advisories for portions of the southern Plains and lower to middle Mississippi Valley. A marginal risk of excessive rainfall/flash flooding is expected for portions of the Southeast and central Plains today and Monday due to uncertainty in the placement of the heaviest rainfall. Both the Southeast and northern Plains should see an enhanced risk for heavy rains on Tuesday as stronger systems aloft approach from their northwest and west respectively. To the west, a flat, but strengthening, ridge of high pressure is expected to extend across the Four Corners through Tuesday. This should allow disturbances near and south of the U.S./Mexican border to move from east to west, enhancing rainfall within the Southwest Monsoon across the Desert Southwest, western and northern New Mexico, and Colorado this afternoon and evening. As the ridge strengthens on Monday and Tuesday, the prospect for heavy rainfall slowly fades near an elevated boundary trapped in western Colorado, with the greatest risk of heavy rains being confined to southwestern sections of the state. Elsewhere, the progressive cold front moving into the Northeast is expected to lead to heavy rainfall across New England on Tuesday as it taps pool of above average moisture to the south -- a slight risk of excessive rainfall exists here on Tuesday. In the wake of the front, temperatures should become milder across the Great Lakes and Northeast Monday into Wednesday. Otherwise, the weather pattern expected over the lower 48 is generally summer-like through Tuesday, with virtually no record hot high temperatures or record cool low temperatures forecast. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php