017 FXUS61 KPBZ 291739 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 139 PM EDT Mon Jun 29 2026 .WHAT HAS CHANGED... A Heat Advisory has been issued for most of the region from tomorrow through Friday, as confidence in impactful heat is high. Fog is again possible tonight, but is expected to be less widespread. && .KEY MESSAGES... 1) Heat Advisory issued for most of the region from tomorrow through Friday. High confidence in dangerous, impactful heat. 2) Potential for strong thunderstorms Friday and next weekend. && .DISCUSSION... KEY MESSAGE 1... Not much change to the previous thinking. Mid-level ridging is still forecast to build into the region and persist into Friday, bringing the first extended run of heat and humidity to the region of the season. While we are still not expecting widespread record high temperatures, there is still a high probability of setting new standard for warm minimum temperatures Wednesday through Friday at several sites. The actual hottest temperatures are expected Wednesday and Thursday, with widespread mid and upper 90s forecast. The higher-end numbers should be observed in urban areas, and instances of triple-digit readings cannot be ruled in a few valleys and downtown areas. Modeled dewpoints may be a touch too high during the afternoon in some cases, as deep mixing may allow some drier air aloft to lower surface dewpoints. Values may end up in the mid and upper 60s in at least some areas as opposed to the more widespread 70-73 readings some models suggest. This may keep heat index values from exceeding 105 in more than isolated cases, and thus may preclude the need for Excessive Heat Watches/Warnings, even on Wednesday/Thursday. Still, there is decent enough confidence in fairly widespread values between 98 and 105 each afternoon beginning tomorrow and continuing into Friday, along with the very warm and muggy overnight conditions, to issue a long-term Heat Advisory running from midday tomorrow into Friday evening for all areas excluding the ridges. While not all areas in the Advisory may technically reach criteria, especially tomorrow, it is believed that the long period of impact, along with the limited cooling potential at night, justifies this widespread and long- lasting product. In addition, heat risk will be in the major category (level 3 out of 4) for Tuesday. An extreme heat risk (level 4 out of 4) is currently forecast for the lower elevations Wednesday and Thursday and depending on thunderstorm and/or cloud cover, Friday. A quick refresher, NWS heat risk is a color-numeric based index that uses high resolution weather, climate, and CDC heat-health data to identify potentially dangerous heat. It is also good to point out that a big driver of impacts to people in heat waves are the overnight low temperatures. This is because people can't cool off at night especially those without air conditioners. If you have friends or family that are sensitive to heat, elderly, or without AC, please check on them throughout the week. KEY MESSAGE 2... Most ensembles suggest that the ridge begins to slowly break down on Friday and continues to do so into the weekend. This would place our region in a WNW flow pattern aloft, which would make the arrival of ridge-running shortwaves, and thus showers and thunderstorms, more likely. This type of pattern raises concerns for the potential for severe weather, as there are certainly past examples of heat waves ending with a round of rough weather. Longer-range machine-learning guidance agrees with this increased threat, as they indicate increasing severe weather probabilities (15-45% for the most part) starting on Friday and continuing into Saturday. There is plenty of time to refine this forecast and the details will be monitored through the week. && .AVIATION /16Z MONDAY THROUGH FRIDAY/... Varying degrees of fog coverage are noted across the region this morning. Fog expansion likely ends here shortly with the sun rising and improvements are expected to begin by 14z, with much of the area expected to be VFR by 15z. A SCT VFR stratocu field is possible across the region during the daylight hours. Winds are expected to be light and variable once again. Clouds dissipate this evening but can return as another VFR stratocu field on Tuesday as winds rise to 5-10 kts from the SW. Outlook... Mainly VFR is expected through Thursday under high pressure and capping warmth aloft. Shower and thunderstorm chances return Friday as the high begins to weaken. && .CLIMATE... Record High Temperatures for 06/30 (Tue): New Philadelphia OH Area Forecast: 94 Record: 93/1964 Record High Minimum Temperatures for 06/30 (Tue): New Philadelphia OH Area Forecast: 73 Record: 71/1991 Pittsburgh PA Area Forecast: 71 Record: 74/1933 Zanesville OH Area Forecast: 73 Record: 74/1934 -- Record High Temperatures for 07/01 (Wed): New Philadelphia OH Area Forecast: 97 Record: 96/1991 Pittsburgh PA Area Forecast: 95 Record: 98/1901 Zanesville OH Area Forecast: 96 Record: 99/1941 Record High Minimum Temperatures for 07/01 (Wed): Wheeling WV Area Forecast: 74 Record: 75/1901 New Philadelphia OH Area Forecast: 75 Record: 71/2014 Zanesville OH Area Forecast: 74 Record: 73/1913 -- Record High Temperatures for 07/02 (Thu): New Philadelphia OH Area Forecast: 98 Record: 95/1966 Pittsburgh PA Area Forecast: 96 Record: 97/1931 Zanesville OH Area Forecast: 97 Record: 100/1898 Record High Minimum Temperatures for 07/02 (Thu): Wheeling WV Area Forecast: 74 Record: 73/2018 New Philadelphia OH Area Forecast: 75 Record: 73/2018 Pittsburgh PA Area Forecast: 75 Record: 76/1903 Zanesville OH Area Forecast: 74 Record: 71/1903 -- Record High Minimum Temperatures for 07/03 (Fri): Wheeling WV Area Forecast: 76 Record: 77/1903 New Philadelphia OH Area Forecast: 76 Record: 71/1991 Pittsburgh PA Area Forecast: 76 Record: 76/1898 Zanesville OH Area Forecast: 75 Record: 78/1935 && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...Shallenberger/CL AVIATION...AK