Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
188 FXUS61 KPBZ 281915 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 315 PM EDT Sun Aug 28 2016 .SYNOPSIS...
-- Changed Discussion --
Thunderstorm chances will continue through the evening as a weak boundary crosses the region. Warm but less humid conditions will be introduced under building high pressure through midweek.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
-- Changed Discussion --
Weak boundary will sink across the region through the period. A few showers have already popped up in northern PA but consensus is that coverage will increase through the afternoon as we destabilize. Most, if not all of the model guidance suggests greatest thunderstorm chances will be north of I-70 supplemented by the passage of a shortwave and very minimal cooling aloft. Steep low level lapse rates would suggest some storms may produce strong wind gusts through the evening, if they can maintain themselves. In addition, high PWATs and little steering flow may lead to some localized flooding concerns if storms train over the same areas. Convection should fade with the loss of heating tonight but the boundary will become rather diffuse over the region, so some cloud cover may linger over the southern portion of the CWA and keep low temperatures on the warmer side of guidance.
-- End Changed Discussion --
&& .SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
-- Changed Discussion --
Newest model guidance pushes the aforementioned boundary south of the region by Monday afternoon as reinforcing shortwaves help deepen a trough over the Northeast U.S. through midweek. The surface front may continue to provide focus for diurnally- enhanced convection over the mountains in WV, but building surface high under northwest flow should suppress precip by Tuesday. A second and more notable boundary, as far as temperatures change, will approach on Wednesday. At this time, it appears that instability and moisture will be rather meager with this fronts passage so very low pops were kept, based on a blend of guidance and timing differences through Wednesday. Temperatures should moderate to near normal with northwest flow/cool advection by Wednesday.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Troughing over the eastern CONUS will result in cooler temperatures the remainder of the week before ridging builds back in this weekend. Dry conditions are forecast under dry northwesterly flow and ridging later in the period. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... Warm air aloft has been capping off convective development thus far, however, weak surface convergence, slightly cooler temperatures aloft, and the passage of a weak wave in the mid and upper levels looks more likely than not enough to trigger convection by late afternoon into early evening. Outflows from early convection should be deep enough to continue initiate storms from northwest to southeast heading into early evening but will diminish as instability lessens. Do to the degree of uncertainty in timing have opted to utilize mention of VCTS in latest TAFs but will update as details emerge through the afternoon. .OUTLOOK /MONDAY THROUGH THURSDAY/... Restrictions are possible Monday mainly S of PIT as the front completes its passage, and again with another crossing front Wednesday. && .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.