Radar — KPBZ
Surface Analysis — Eastern U.S. (Central)
Satellite
Nearest monitored road: Grant Street (Primary)
Messaging focused on the weekend when widespread precipitation chances return, but with limited risks.
1) dry and seasonable weather favored this week before widespread rain returns this weekend.
Key message 1... The upper ohio river valley remains on the western periphery of a fairly stagnant closed low over the new england region; such pattern does offer low probability afternoon shower and thunderstorm chances today mainly over the higher terrain SE of pittsburgh (where convergence best aligns). It otherwise fosters dry weather with seasonable temperature that sees subtle temperature rises to end the week as pressure heights aloft slowly increase.
The weekend outlook features the next trough system slowly crossing the region while generally sitting well south of the main jet stream farther north. Modest moisture returns combined with trough-induced lift likely results in an uptick in widespread showers and thunderstorms favoring the afternoon to early evening hours. Pending the trough depth and eastward track, there are low probability scenarios to amplify moisture returns in SW flow such that it creates a low-end flash flood risk (pwats rise toward or above the 90th percentile; weak-flow aids slow-moving storms; enough CAPE to allow for warm-rain processes). This bears monitoring in what otherwise appears to be a low impact pattern given meager CAPE and SHEAR values.
Enough cool advection over lake erie plus moisture convergence along the higher terrain as the surface low sits NE of the region will create opportunities for generally MVFR stratocu through 14Z. More limited moisture within the boundary layer likely results in ceilings to bounce between scattered and broken while offering some variability in on set timing that may not be fully captured in latest taf.
Diurnal heating and mixing should lift any stratocu to VFR heights by around 18Z wednesday (though a brief period of broken MVFR could occur amid rising) while dry advection slowly erodes cu coverage. There may be enough lift within the NW/N upper flow to produce an isolated afternoon shower (favoring east of i-79) but probability of terminal impact is too low for a mention.
Outlook... VFR is favored thursday into friday under the influence of high pressure and height rises aloft. The next period of active starts saturday and continues into early next week with the slow passing of an upper level trough.