FXUS61 KPBZ 050555 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 155 AM EDT Tue May 5 2026 .WHAT HAS CHANGED... No significant changes were made to the forecast. && .KEY MESSAGES... 1) Active weather pattern expected through the weekend 2) Gusty winds expected today 3) Frost possible Thursday night && .DISCUSSION... KEY MESSAGE 1... A cold front will approach the area today, slowly sinking southwards towards the region. Nearly boundary-parallel flow will keep progression slow, crossing into the region late this afternoon/evening and becoming nearly stationary overnight into Wednesday. Shower/storm chances will increase from the NW through the day, but should mainly be confined north of PIT through at least late afternoon. Shear and instability will be even more limited today, with ML CAPE less than 500 j/kg and limited shear. Warm air aloft should also limit buoyancy, capping any severe weather potential. Showers and embedded thunderstorms will become more widespread this evening and overnight as the front slowly drops south across the area. A wave of low pressure is then progged to track along the front on Wednesday as it stalls across the Ohio Valley and central PA, maintaining more showers and isolated thunderstorms. Much cooler temperatures are expected north of the front, with highs near 10 degrees below average. The front should finally exit the region on Thursday as flow turns more WNW, but it will remain in close enough proximity to maintain shower chances across much of the area Thursday. While the front's influence on our weather will end Friday, a series of shortwaves rotating through the broad upper troughing will keep periodic shower chances in the forecast through the weekend and early next week. KEY MESSAGE 2... A 40-50kt low-level jet will slowly cross the area today. Though strongest during the pre-dawn hours, a decoupled boundary layer and surface inversion should keep gusty sfc winds at bay. After sunrise, gusts should ramp up quickly with deeper mixing. Soundings indicate gusts of 35mph -- possibly occasional gusts up to 40-45mph -- are possible late this morning and early afternoon, especially across the higher terrain. Gusts should remain below Wind Advisory criteria, but nuisance gusts are likely. KEY MESSAGE 3... There is some potential for frost Thursday night, though this will be highly dependent on the amount of cloud cover in place and the resulting radiational cooling. && .AVIATION /06Z TUESDAY THROUGH SATURDAY/... Scattered showers and thunderstorms will move through the region overnight tonight with weak forcing. Latest ACARS soundings and mesoanalysis support enough confidence in thunder to include TEMPO groups at all terminals for -TSRA with temporary reduction to vis while cig likely remains VFR with high cloud bases. Some small hail is possible if a stronger storm directly impacts a terminal, but confidence in that is low. Should see showers and storms exit near sunrise. Low level wind shear will remain a threat through much of the overnight hours with a decoupled surface layer and sustained wind around 10 knots beneath a stout 40-45 knot low level jet. With mixing and departure of the jet come sunrise, LLWS threat will cease. Much of Tuesday will be dry with high confidence VFR and gusty southwest wind around 25-30 knots with the probability for >30 knots around 30-40%. Have then maintained the introduction of PROB30 groups for showers forming out ahead of an approaching cold front, but we likely won't see steady rain arrive until around 00z for ZZV, 03z for PIT, and 06z for LBE. Once it does, MVFR restrictions likely come from visibility first before sufficient saturation drops cigs to MVFR with an 80+% chance areawide in the pre-dawn hours on Wednesday. Have erred much more in line with HREF/REFS guidance for this period instead of NBM which seems much too quick with rain, restrictions, and aggression of restrictions. IFR probs increase as well after sunrise on Wednesday, but fall outside of the current TAF period, so further updates will address continued restrictions into the morning hours. Outlook... Rain will taper off Wednesday afternoon as VFR gradually returns behind the departing cold front, though low level cold advection may reinforce cigs into the evening. A few showers may try to sneak in from the south on Thursday with highest probability for MGW, but otherwise, high pressure then returns to close out the week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...WM/Rackley AVIATION...MLB