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 291844 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 244 PM EDT FRI JUL 29 2016 .SYNOPSIS... A series of weather disturbances will keep showers in the forecast through the weekend. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
A weak surface boundary remains splayed out from Indiana through northern Ohio and far NW Pennsylvania at this hour. To the south of it, widespread upper 60s to lower 70s remain in a weakly forced, soupy environment. Steering flow is weak, but instability seems to be increasing readily as the afternoon wears on given the dissipation of stratus and formation of cumulus. Showers and thunderstorms have developed, primarily along the interfaces of weaker stability left behind by differential heating from a bit earlier on. The activity that has develop is generally being propagated along by the cold pools that are developed in-situ, thus movement has been fairly slow. It does seem that as the afternoon and evening wears on, a preferential trend toward SE movement of activity should develop, resulting in increased shower and thunderstorm activity in our area. Upstream convection currently over Illinois and northern Indiana will likely weaken as it starts to move eastward overnight. However, residual cloud cover will remain, and this should make a trend in sky cover toward mostly cloudy result overnight. Cloud cover will work to hold temperatures up a bit overnight as a result. Fries
-- End Changed Discussion --
&& .SHORT TERM /SATURDAY THROUGH MONDAY/...
-- Changed Discussion --
A weakly coupled upper jet structure looks to work across the area on Saturday with the continuation of a moist and unstable boundary layer in place. Increasing upper divergence through the day will allow for the flourishing of showers and thunderstorms over the area on Saturday. Mid-level moisture flow from E-W will continue to lift north of the area as the system digs over the region Saturday night, resulting in the best chances of showers and thunderstorms slowly translating NNEward. Another wave will dig into the base of the upper level trough by Sunday afternoon. This will bring another increase in the chances of shower and thunderstorm activity across much of the area as the mid-levels start to nominally cool. It will also start to usher in drier mid and upper level air as it does so. This will allow for the reduction in the chances of precipitation by Monday as cooler NWerly flow becomes entrenched over the area. Fries
-- End Changed Discussion --
&& .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
Surface high pressure will build into the area from the western Great Lakes Monday night into Tuesday. This will allow the area to remain in cooler northerly flow even as subsidence builds. A dry forecast will thus be maintained through mid-week. Ridging at all levels of the atmosphere should thereafter increase from mid-week onward as amplification of the pattern is evident on basically all guidance over the upper Mississippi Valley and northern Great Lakes during the second half of the week. This ridge and resultant low level thermal ridge should start to flop over toward our area by Friday, which at this point looks to be the warmest day of the next week or so, when temperatures should push again well above normal. Fries
-- End Changed Discussion --
&& .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
VFR conditions this afternoon with minimal thundershower chances. Exception being KFKL and KDUJ where some MVFR conditions and TS possible. given low level moisture tonight expect a return to some fog and stratus...but not as dense and as long lasting as this morning. Precipitation chances will increase for saturday ahead of an approaching shortwave. .OUTLOOK /FRIDAY NIGHT THROUGH TUESDAY/... Broad upper troughing should maintain periodic shower and thunderstorm restriction potential through Monday.
-- End Changed Discussion --
&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.