Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 240435 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1235 AM EDT SUN JUL 24 2016 .SYNOPSIS... Hot and humid conditions will continue. The best chance for showers and thunderstorms will return on Monday with the passage of a weak cold front. && .NEAR TERM /THROUGH TODAY/...
-- Changed Discussion --
Quite the dewpoint discontinuity remains over the area early this morning as the weak surface boundary has sagged southward. However, rainfall along it has managed to dissociate the boundary layer locally around Pittsburgh, where a very moist boundary layer remains even in its wake. Regardless of that, low level flow looks to quickly turn west-southwesterly toward morning. This will bring the air currently residing over southwestern Ohio toward our CWA. As a result, dewpoints should climb rapidly into the daytime on Sunday as the boundary lifts back north of the area. A convective complex currently decaying near Chicago will manage to spread high clouds toward the area for portions of the day on Sunday as model RH projections do surge above 500 mb toward morning. However, even in the upper levels, flow does manage to back a bit more southwesterly through the day on Sunday, which should shunt a bit of that moisture northward by afternoon. What was particularly unusual on Saturday was the spread of 90F+ temperatures across the area with 850 mb temperatures that really didn`t even manage to meet 20C. That said, the drier boundary layer present in some areas on Saturday will not be readily apparent on Sunday with dewpoints surging toward and above 70F. However, consensus 850 mb temperatures manage 22C with 23C likely toward Morgantown. This should put the majority of the area into the 90s for highs...and even well into the 90s over Ohio. Thus with dewpoints increasing and high temperatures at least as high as Saturday even with more high clouds, a heat advisory will likely need to be coordinated for all Ohio, non-mountainous West Virginia, and southwestern Pennsylvania counties generally south of the turnpike. Fries
-- End Changed Discussion --
-- Changed Discussion --
An upper-level trough and its associated front will approach from the west early Monday. Based the current model run timing, some precipitation may already be moving into the area Monday morning, which may limit the threat for any strong to severe storms despite instability and moderate shear. For now, agree with SPCs analysis of a Marginal Risk for the region. Ahead of the boundary, where we remain cloud free early, temperatures should still warm well into the 80`s and approach 90. Front will stall just south of the PA/MD border by Monday night and we will remain in zonal flow. This could lead to lingering chances of showers/storms, mainly along the terrain on Tuesday. While dewpoints will be lower, it should still be another day of mid-80 temperatures.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Zonal flow will be replaced by weak troughing over the eastern CONUS for the end of the week. With several shortwaves progged to pass in the upper level pattern, but differences in the deterministic models, have opted to stay close to a blend of guidance with near or slightly above normal temperatures forecast. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... Convection is largely over as instability wanes. Visibility restrictions are possible mainly KBVI and south where rainfall occurred earlier and drier air at the surface has not yet moved in out of the northeast. There will be a chance of thunderstorms Sunday afternoon as the boundary that currently runs roughly from KCLE to KLBE lifts north over the region as a warm front. .OUTLOOK /SUNDAY THROUGH THURSDAY/... Restrictions will be possible late Sunday and Monday with the approach and passage of a weak cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.