Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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570 FXUS61 KPBZ 101207 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 807 AM EDT Wed Jul 10 2024 .SYNOPSIS... Low probability showers remain possible with a limited severe threat through this afternoon, otherwise the exiting hurricane remnants will introduce temperature moderation tonight into Thursday. Well above normal temperature is favored Friday through the weekend with high pressure limiting precipitation chances. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Hi-res model trends continue bearish outlook on convective development in area, keeping most storms north and east. - If storms can develop, low probability exits for damaging wind and tornado. ------------------------------------------------------------------- Remnants of former Hurricane Beryl will continue to lift northeast through the Great Lakes today as its low center remains west of the forecast area. Latest analysis shows the elevated warm front lifting north of the region and the region being dry slotted while the surface cold front approaches from the west. Outside of a few showers entering far eastern Ohio ahead of the surface, the morning period will likely be dry with the surface cold front nearing the WV panhandle. Hi-res models continue to be bearish of convective development during the afternoon ahead of the cold front (favoring locales farther north and east). 6hr probabilities of more than 0.10" of rain barely reach 30% in northwest PA, with lower values elsewhere. But a conditional severe risk remains a topic of discussion; IF storms do develop (focusing on the 1pm-6pm time frame), there is a risk for damaging wind and tornadoes in portions of northwest PA where instability can be maximized along with strong shear (both 0-6km and 0-1km). The upper shortwave will exit northeast overnight as flow aloft briefly becomes zonal and sees an influx of mid-level moisture that is wrapped around the low center. Better chances for rain showers exist tonight for portions of eastern Ohio into northwest PA result from this feature. Otherwise, most locations are unlikely to see rain while temperature falls closer to daily averages. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... KEY MESSAGES: - Lingering moisture may result in an isolated to scattered afternoon shower Thursday. - Temperature moderation will be brief as highs return to above normal levels Friday. ------------------------------------------------------------------- The main trough axis will remain parked over the lower Ohio River Valley Thursday into Friday, maintaining southwest flow over the region. Residual moisture and cool advection on the backside of Wednesday`s exiting low will offer morning cloud cover, low probability showers (favoring northwest PA) and more seasonable temperature. High pressure and column warm advection will quickly return plenty of insolation to the region Friday as highs climb 5 to 10 degrees above the daily average. The main source of uncertainty for the day will be the degree of cirrus coverage working NW from a surge of tropical moisture/convection entering the Carolina Region. This could limit diurnal heating a bit for locations across northeast WV and the Laurel Highlands. && .LONG TERM /SATURDAY THROUGH TUESDAY/... KEY MESSAGES: - High confidence in well above normal temperature leading to increased heat risks through the middle of next week. - Early indications suggests increased precipitation chances during the period with non-zero severe weather potential. ------------------------------------------------------------------- The upper level pattern will be relatively unchanged Saturday as a low pressure system traverses the New England region and weak shortwaves drop through the western Great Lakes. In between, the Upper Ohio River Valley is expected to be hot and stagnate as low 90s temperature becomes likely for most locations. Ensembles favor a continuation of those hot and potentially humid conditions to persist through next week, but this comes with high variance tied to shortwave movement. Models suggest shortwave movement will occur sometime Sunday into early next week (or potential multiple waves) that lower heights over the region and introduce increased precipitation chances. Details are too noisy to discern, but the pattern is emblematic of a series of MCSs traversing the Great Lakes with potential impacts/timing (and alterations to temperature) being influenced by previous days outcomes. This pattern recognition is noted in various AI weather models, meaning that there is a non-zero chance for hazardous weather (with this meteorologist leaning towards multiple days of at least a damaging wind threat). Will mention concern in HWO along with potential heat to aid decision makers to monitor the latest trends. && .AVIATION /12Z WEDNESDAY THROUGH SUNDAY/... Showers and thunderstorms are ongoing predominantly north and west of the local area this morning in association with the remnants of Hurricane Beryl as they pass by to the northwest of the area today. This is where the activity should generally remain today as a dry slot makes its way into the local area, keeping overall precip chances low at area terminals. As such, left mention of rain and thunder out of most TAFs, except ZZV where showers at the start of the TAF period are currently departing to the north, and at FKL/DUJ where there is a 30-40% chance late this afternoon. Any restrictions this afternoon and evening will be limited to showers and storms as VFR is expected to prevail outside of convection. Ensembles have high confidence (>80% chance of MVFR) in widespread ceiling restrictions building in overnight, including 60-80% probabilities for IFR at FKL/DUJ/BVI and 30-50% at all other terminals except ZZV. Low cigs linger through the end of the current TAF period, likely not lifting/scattering until later Thursday morning or afternoon. Residual showers on the backside of the general trough system may also linger into Thursday morning for eastern OH/northwest PA. Southwest winds will be gusty today as prevailing speeds increase to 15-20 knots with gusts as high as 30-35 knots. Winds will be slow to settle tonight due to a lingering tight pressure gradient associated with the passing surface low. Gusts to 20-25 knots could continue through overnight hours until winds finally beginning to settle early Thursday morning. .Outlook... Ensembles favor VFR returning to the area Thursday afternoon and staying in place thereafter. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Frazier NEAR TERM...Frazier SHORT TERM...Frazier LONG TERM...Frazier AVIATION...Cermak