####018004948#### FXUS61 KPBZ 161623 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1223 PM EDT Sun Aug 16 2026 .WHAT HAS CHANGED... There is higher confidence in the potential for severe thunderstorms this afternoon, given clearing skies to the west allowing for increased instability. Beyond this evening, little change was made to the forecast. && .KEY MESSAGES... 1)Severe weather and flash flooding risks continue this afternoon and evening with renewed thunderstorm development. 2) After lingering showers dissipate Monday, there is fairly high confidence in dry weather until Wednesday/Thursday, when the next front arrives. && .DISCUSSION... KEY MESSAGE 1... The region remains in a relative lull of activity between overnight/early morning activity and developing convection to the west, where a couple of Severe Thunderstorm Warnings are already in effect. The new activity is associated with a vort max/MCV over northwest Ohio. Ahead of this, a good deal of sunshine is allowing for a buildup of instability, and the HREF suggests that 1500-2500 J/kg of surface-based CAPE is likely by 18Z, mainly south of I-80. Other convective parameters look best from I-80 on south, roughly matching with the SPC Slight Risk area. In particular, a pocket of 25-30 knots of 0-6km shear is most likely in this region, supporting multicells with mainly a damaging gust potential where cold pools help consolidate into short lines. Lengthening low-level hodographs and sufficient 0-1km SRH continue to suggest a low-end tornado threat for any ESE-moving storms. Along with this the threat of flash flooding will continue to be monitored, especially in areas that got heavier rain overnight. This includes areas in eastern Ohio south of I-70, as well as a strip extending from New Philadelphia ENE towards Butler County. Although storms should be fairly progressive overall, the environment remains highly supportive for efficient rainfall production. The 12Z KPIT sounding recorded a precipitable water measurement of 2.15 inches, which is the 9th-highest recorded at the site since 1952. 2+ inch values remain in place through this evening, along with 11k to 13k warm-cloud depths. The Flood Watch will be maintained through tonight. KEY MESSAGE 2... Most of the convection should pull off to the east by 02Z-03Z, although a few showers/storms may linger behind the main line as another shortwave trough crosses in the mid-level zonal flow. One last ripple in that flow crosses on Monday, leading to showers and storms mainly south of Pittsburgh. Convective parameters are unfavorable for severe weather with this activity. Also, declining precipitable water values point to a decreasing risk for heavy rainfall. The Flood Watch expires at 8 AM Monday, and an extension may not be needed. High pressure building in from the Great Lakes should end precipitation by Mon evening. Dry weather is then favored until Wednesday, when the next front could potentially arrive, although this timing could change. At this time, severe weather and flooding risks appear low with this system, as supported by longer-range machine learning guidance. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/... Showers and a few thunderstorms will continue across portions of the area this morning as a warm front lifts across the region. A period of MVFR to IFR cigs are also expected this morning with low level moisture in place. Some improvement to MVFR is expected through the afternoon with some surface heating and mixing. Expect another round of thunderstorms to develop this afternoon ahead of another approaching shortwave and prefrontal trough. Some of these storms could be severe with damaging wind and heavy rainfall. For now, indicated some wind potential in the TAFs in the tempo mention for thunder. Expect deterioration to MVFR, and eventually IFR, this evening as the thunderstorms exit, and low level moisture lingers. IFR stratus should then continue into early Monday morning. Outlook... Showers, restrictions, and possible thunderstorms are expected for Monday as a cold front crosses the region. Other than early morning fog, VFR is then expected through early Wednesday under high pressure. Restriction and shower/thunderstorm chances return Wednesday and Wednesday night with the approach and passage of a cold front. VFR returns Thursday under high pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...Flood Watch through Monday morning for PAZ020-021-029-031- 073>076. OH...Flood Watch through Monday morning for OHZ039>041-048>050- 057>059-068-069. WV...Flood Watch through Monday morning for WVZ001>004-012-021- 509>514. && $$ DISCUSSION...CL AVIATION...WM