FOUS30 KWBC 131559 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1059 AM EST Fri Nov 13 2026 Day 1 Valid 16Z Fri Nov 13 2026 - 12Z Sat Nov 14 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF NORTHERN/CENTRAL CALIFORNIA... A progressive cold front moving through northern and central California this morning/afternoon will likely generate scattered to organized thunderstorms. Heavy rainfall leading to isolated instances of flash flooding is possible, especially for urban areas like San Francisco and Sacramento. Precipitable water values around 1" and most unstable cape values peaking around 500J/Kg by late this afternoon/early evening may produce 0.25-0.5" rain rates. Hires guidance have anywhere between 1-3" of 24 hour QPF ending at 12z on Saturday morning. The marginal risk area (at least 5% chance) is consistent with Colorado State University's Machine Learning Product first guess field, which highlights much of northern/central California with 5-15% probabilities of excessive rainfall ending at 12z tomorrow morning. Kebede Day 2 Valid 12Z Sat Nov 14 2026 - 12Z Sun Nov 15 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS NORTHWEST WASHINGTON STATE IN THE AREA OF THE OLYMPIC PENINSULA... 00Z guidance continues to show the arrival of another round of moderate to heavy rainfall across portions of northwest Washington and the Olympic peninsla on Saturday. The two-day rainfall total ay be enough to result in isolated flash- and areal-flooding. Rainfall forecasts of an additional 1 inch to 3 inches, with locally higher amounts, are expected through Saturday night or early Sunday morning. Much of the rainfall is expected to occur in a 12-hr window before the passage of a cold front late in the forecast period. This could send some of the river banks overflowing and cause some local flood concerns, some of which could be flashy. Still felt there was no fundamental changes needed with the latest forecast. Bann Day 3 Valid 12Z Sun Nov 15 2026 - 12Z Mon Nov 16 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF EASTERN TEXAS AND WESTERN LOUISIANA SUNDAY... Only minor adjustments to the Marginal Risk over eastern Texas and western Louisiana were made this outlook cycle given continued model signals for potentially excessive rainfall near the Gulf coast. There was little resolution to the question whether the heaviest rainfall stays off-shore or if makes its way inland. Consensus of the preferred guidance still indicates the heaviest amounts are likely to center near the upper Texas/southwestern Louisiana coasts, Some models are showing amounts that would warrant an upgrade along the coast as northern stream energy overtakes a leading southern stream wave. That would provide providing the necessary lift to support scattered convection. However, with limited instability would likely temper rates to the north. However, due to uncertainty regarding whether the heaviest rainfall will develop offshore, held off from upgrading to a Slight Risk once again. Bann Day 4 and Day 5 Valid 12Z Mon Nov 16 2026 - 12Z Wed Nov 18 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. An upper-wave will continue eastward along the Gulf Coast Day 4/Monday. Strengthening high pressure to the north as well as northerly flow in wake of the wave should help to drive a frontal boundary across Texas southeastward into the Gulf. This should keep greater moisture/instability and the focus for storms mostly offshore compared to Sunday. Even if the boundary/storms were to set up a bit further north along the coast, FFGs are high and would require a much greater signal for widespread coverage/several inch rainfall totals to raise a concern for flash flooding. To the west, an upper-trough and accompanying cold front will progress eastward from the West Coast into the Interior West Monday-Tuesday. Increasing moisture along and with the frontal passage will lead to scattered thunderstorms across the Desert Southwest. However, limited instability should keep rates low and the progressive nature of the system passage should limit rain totals overall. Putnam Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt $$