Quantitative Precipitation Forecast Discussion NWS Weather Prediction Center College Park MD 254 PM EDT Sun Jun 03 2018 Prelim Day 1 QPF Discussion Valid Jun 04/0000 UTC thru Jun 05/0000 UTC Reference AWIPS Graphics under...Precip Accum - 24hr ...Mid Atlantic/Northeast/Great Lakes/Ohio Valley... A meandering low over centered over eastern Virginia will continue to support areas of moderate to heavy precipitation across portions of the Mid Atlantic through the remainder of the afternoon into the evening hours. Deep saturation through the air column continues to support very efficient rain processes, with some areas continuing to see heavy amounts accumulate quickly. The heavy rainfall threat is still expected to diminish this evening as a upstream trough moving across the Great Lakes begins to drive the low offshore. This low is expected to move off of the Mid Atlantic coast overnight, with the models in generally good agreement taking the system south of New England on Mon. Strong southerly low level flow ahead of the low is expected to direct a plume of deep moisture into coastal southern New England on Mon, with the GFS showing PWs increasing to around 2 inches on Mon. This moisture interacting the with favorable upper dynamics ahead of an upstream low closing off over southeastern Canada, is expected to support some moderate to heavy rains across southeastern New England. Increasing instability and deepening moisture ahead of the aforementioned upper trough and its associated cold front should continue to support developing showers and thunderstorms across the Ohio valley into the central Appalachians this afternoon, with enhanced divergence ahead of the upper trough supporting a greater threat for heavy amounts across eastern Ohio into western Pennsylvania and West Virginia this afternoon. As the front pushes further east into a more stable airmass, rainfall rates are expected to diminish while the system moves across central to eastern Pennsylvania and New York overnight. However, the moisture and forcing ahead of the front may be sufficient enough to produce moderate to locally heavy amounts, especially across portions of Upstate New York. ...Southern Rockies/Plains... Southwesterly flow ahead of shortwave trough moving into the Four Corners region continues to moisten the mid levels across New Mexico and southern Colorado as southeasterly winds behind a cold front that has settled southwest into West Texas begin channel low level moisture into the region. This will continue to support developing storms across the mountains before spreading east into the High Plains this afternoon and evening. With PW anomalies increasing to 2-3 standard deviations above normal, there remains a good model signal for locally heavy accumulations this afternoon and evening from the southern Colorado and New Mexico ranges southeastward into the adjacent High Plains of eastern New Mexico and West Texas. Forecast confidence diminishes overnight as the hi-res models show significant spread with respect to how quickly convection diminishes as it moves further east into central Texas. While the NAM CONEST shows widespread moderate to locally heavy amounts spreading east into central Texas, the HWR-NMMB shows convection diminishing much sooner with only scattered light amounts. WPC QPF reflects a compromise similar to the HREF Mean, maintaining at least some light to moderate amounts along an axis of deeper moisture and greater instability across central Texas. As the aforementioned shortwave continues to move east, models continue to differ late in the period with possible convective redevelopment across central into southeast Texas, with the NAM CONEST this time being the much drier solution. With limited confidence, continued to follow the HREF Mean through the end of the period. Pereira