SHORT TERM /MIDNIGHT TONIGHT THROUGH SATURDAY NIGHT/...
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Key Messages: * A strong cold front will move through near noontime on Friday, bringing strong to locally damaging winds and moderate to heavy rain, along with isolated thunderstorms. * Potential tying or record breaking temperatures early Friday fall back into the 20s Friday night, to below normal levels. Any leftover moisture may freeze if drying does not occur. Rain ahead of a cold front becomes more likely as the nighttime progresses with most of the area likely seeing rainfall by sunrise Friday. Strong low level jet lift and moisture convergence, plus a potential convective element with elevated instability, could cause the rain to be heavy at times. The heaviest rainfall likely occurs starting around sunrise with some impacts to the morning commute with the threat continuing until the cold front passes through late morning/early afternoon with a line of convectively-enhanced showers. Areas of minor/poor drainage flooding are anticipated. Flash flooding is not a concern at this point with the system pushing through fairly quickly and the liquid equivalent of any remaining snow pack is probably no more than a tenth of an inch. Still a chance of a shower in the afternoon behind the cold front, an maybe even some snow mixed in well NW of the city towards sundown. Regarding winds, an 80-90kt low level jet at 925mb shifts through much of the coastal area during Friday morning. Forecast soundings however show a strong low level inversion, so it appears that winds are going to have a tough time mixing down to the surface. It might take surface temps reaching 60 degrees to get mixing deep enough to bring down gusts strong enough for high wind warning consideration, and some spots may warm up close to this. Thinking is that about 50% of the 925mb jet winds could still mix down anyway, which translates to higher-end wind advisory gusts, but cannot completely rule out a gust or two that reaches warning criteria. Not enough confidence that the occurrence would be widespread enough to warrant a high wind warning, but will keep messaging the threat of isolated 60mph gusts in the advisory. No change to the end time of the advisory, but can`t rule out 46mph+ gusts for a couple of hours after midnight. High temperatures likely occur in the morning right ahead of the rain - generally in the mid to upper 50s. This is close to record high temperatures for the day. See the climate sections below for these records. Temps then fall somewhat with the rainfall, then fall more steadily in the afternoon with the start of cold air advection behind the front. A more rapid drop in the temperatures then happens this evening as the advection strengthens behind the front. Depending on how much winds can dry out surfaces before temps fall below freezing in the evening, there could be spots where freezing of standing water occurs. Dry weather for Friday night with high pressure building in. Winds will gradually diminish overnight. The high pressure ridge then shifts through the region Saturday afternoon and keeps us dry through Saturday night. Any precip with weak warm advection at night should remain to our north. Saturday`s high temperatures are expected to be just below normal.