Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 850 PM EDT Fri Jul 11 2025 Day 3 Valid 12Z Sun Jul 13 2025 - 12Z Mon Jul 14 2025 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE SOUTHERN PLAINS AS WELL AS FOR PORTIONS OF THE MID-ATLANTIC... ...Southern Plains... 20Z Update: SLGT risk was expanded to the southwest across TX to encompass the secondary focal area that has grown in consensus over the past succession of forecasts. Residual heavy rainfall is likely over parts of West TX into the Concho Valley with the risk potentially being extended/shifted south if trends continue. Contingency on the development of any MCV could exacerbate concerns in any area within the SLGT, but especially across West TX and OK where the potential is highest. Locally significant flash flooding is plausible in proximity to any MCV development, so will have to monitor the situation closely as we move through the weekend. Kleebauer ..Previous Discussion.. A Slight Risk of excessive rainfall is in effect for many of the same areas highlighted in the Day 2/Saturday ERO, for much of West and North Texas through Eastern Oklahoma. For now, rainfall amounts come down quite a bit on D3 as compared to D2. Thus, the flooding potential will be significantly dependent on how the forecast rainfall compares with Saturday, as well as how much rain actually falls in the Slight Risk area on Saturday. Thus, for now, a Slight Risk upgrade was introduced due to the likelihood for additional strong thunderstorms in this area. Atmospheric moisture amounts will increase on Sunday as compared with Saturday. The upper level shortwave that forced the storms on Saturday will likely get left behind and cutoff from the primary jet flow on Sunday. This slow moving drift of the forcing should allow the storms to also remain slow moving, and with increased moisture, the heavy rain potential will very much still be in place on Sunday. Thus, there is some expectation that forecast rainfall amounts in this area will increase with time. Should this continue to be in the same area as Saturday's storms, then it's likely additional upgrades will be needed with future updates. ...Mid-Atlantic... 20Z Update: Main change for the forecast was the removal of the SLGT risk across the Mohawk Valley in NYS. FFG's in this area remain elevated as they have missed a bulk of the convective impacts the past week. Further west, the signal looks pretty robust for heavy rainfall over Central and Western NY state down through Northern PA. The threat over the Mid Atlantic area remains on the lower end of the threshold, but compromised soils from previous convective episodes brings about some climatologically lower FFG's, thus greater sensitivity. No changes were made to the previous forecast in those areas as models maintain continuity in their potential. Kleebauer ..Previous Discussion.. The shortwave that brought heavy rains across the Midwest on Friday and Saturday will continue into the Mid-Atlantic and Northeast on Sunday. By Sunday the shortwave will be lifting northeastward and becoming more negatively tilted. This will increase the associated divergence and lift. Meanwhile, plentiful Gulf/Atlantic moisture will stream northward ahead of the shortwave, as PWATs in some areas exceed 2 inches. This very high level of atmospheric moisture will support a renewed round of heavy rain from strong thunderstorms from the DMV north across much of Pennsylvania and upstate New York. For New York, being both at the nose of the low level jet and in the area of greatest upper level forcing will further increase the likelihood for training heavy thunderstorms. Meanwhile in the DMV, while overall coverage of storms will be lesser, given the recent storms (and likely isolated to widely scattered coverage both Friday and Saturday), a Slight Risk was introduced for this portion of the Mid-Atlantic. The greatest flash flooding potential will be up towards the eastern Finger Lakes/Central New York, and additional upgrades in this area appear likely, especially with low FFGs already in place. Wegman Day 3 threat area: www.wpc.ncep.noaa.gov/qpf/99epoints.txt