Area Forecast Discussion
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000 FXUS61 KPBZ 220525 AAC AFDPBZ Area Forecast Discussion...UPDATED National Weather Service Pittsburgh PA 1225 AM EST Sun Jan 22 2017 .SYNOPSIS...
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The run of mild weather will continue through midweek. Rain will move back over the area later today and continue into Tuesday.
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&& .NEAR TERM /THROUGH TODAY/...
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No major changes to the overnight period. Some minor adjustments to PoPs and clouds. Temperatures have been refreshed with a blend of hires guidance. Still seeing the models trying to get the final solution for the upper level low which will be the main player in our weather through early Tuesday. Even ensemble data is struggling to come to a consensus on the path and speed of the upper level low. Have backed off on the timing of the showers today as ensembles have slowed the eastward movement of the system and are advertising a track that is a bit further south. Operational models, including the hires variety, agree with this idea, as qpf only reaches Southern West Virginia by this afternoon. This is mostly due to the aforementioned more southern path of the upper low and also the further suppression south of the main jet swinging around the low. Additionally, the first upper level wave that is pushing the showers northward, splits from the main flow and heads eastward into the still prevalent, although weak, eastern ridge. Have continued to lean away from the NAM op solution, as it has been an outlier during the entire evolution of the system. Today`s PoPs will mainly cover the southern third of the region and will begin the process of overspreading these locales during the afternoon. Temperatures again will be well above normal.
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&& .SHORT TERM /TONIGHT THROUGH TUESDAY/...
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Model depictions of the cutoff low pressure set to dig toward the Upper Ohio Region, have deviated from previous days solutions with a more westward track of the center. Increasing ascent via deformed flow and warm advection with increased moisture through the mid levels all support escalating precip probabilities to categorical numbers tonight and into Monday. With the northern branch of split flow holding colder air north and west of the region, and with warm advection into the mid levels of the cutoff, this looks to remain a rain event. The NAM again deviates from other model solutions and develops sub-zero air over the region at the 850mb level despite moist advection and an otherwise warm column. Will continue to move away from the NAM solution. This choice is also further supported when viewing the plumes from the SREF and GEFS model. If colder air does make it into the area, it would likely be late Monday night, when most of the precipitation will have exited the area. QPF was progged using a RFC/WPC blend for the period. An inch to inch and a half is anticipated for the early week with limitations imposed by low pressure progression and mid level dry slotting. Relative warmth will continue, although the diurnal temperature spread will be restricted by clouds and precip.
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&& .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
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By the beginning of the long term, upper level ridging will take over, but will not last long as the next system quickly movew across the northern plains/upper midwest and across the northern Great Lakes on Wednesday. Scattered showers will cross the area Wednesday and above normal temperatures will remain. A pattern change is expected to ensue on Thursday, with a return to January temperatures that will remain through the remainder of the long term. Snow showers will return as well.
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&& .AVIATION /06Z SUNDAY THROUGH THURSDAY/... VFR conditions are expected most of tonight as a crossing shortwave maintains mid level clouds across the area, along with a few light evening showers. Local late night/early morning MVFR fog is possible in some locations as the temperatures falls near the dew point, though cloud cover should preclude widespread coverage. VFR is expected Sunday until the approach of another shortwave later in the day results in a deterioration to MVFR conditions in rain. .OUTLOOK... Restrictions are likely through Tuesday with slow moving low pressure, and again with a Thursday cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$

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