Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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377 FXUS61 KPBZ 071742 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 142 PM EDT Fri Jun 7 2024 .SYNOPSIS... Probability of light precipitation will increase late this morning north of Pittsburgh with passing shortwave. Below average temperatures are also expected into late Saturday. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Probability of rain shower activity increases after day break north of Pittsburgh with a passing shortwave. - Confidence is high that rainfall total amounts through Friday evening will be less than 0.25 inches. -------------------------------------------------------------- Weak shortwave movement through the base of the closed Great Lakes upper trough will provide enough lift to generate isolated to scattered showers across northwest PA. 12z soundings reinforce the idea of a staunch 700mb inversion that will cap storm heights; though up to 500 J/kg CAPE may allow for storm intensification, that cap will keep storm tops below most of the ice layer (below -10 degrees C) and keep lightning and severe weather limited. A drier air mass to the south will help to maintain dry weather as the wave passes. The main impact will be scattered to broken afternoon cumulus as temperature settles a few degrees below the daily average. High pressure and additional cool advection within NW flow will support below average overnight temperature but dry conditions. && .SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/... KEY MESSAGES: - Dry weather with near normal temperature is expected Saturday. ------------------------------------------------------------------- Ridging to the west support a dry and quiet Saturday and the return of near-normal temperature. A shift from west to southwest flow will likely return warm, moist conditions to the region Saturday night. However, temperature will likely still range near the climatological norm. && .LONG TERM /SUNDAY THROUGH FRIDAY/... KEY MESSAGES: - A passing cold front will return rain chances to the region early Sunday. - Cool temperatures to start should warm next week. - Hot conditions may develop late week with a noted ridge in long range models. ------------------------------------------------------------------- Convection returns early Sunday morning as a low pressure ejects out of the Plains and quickly passes into the Ohio River Valley. A few stray showers may evolve ahead a cold front, but Hi-Res model suggest shower activity confided to the boundary. In the wake of the cold front, expected clouds clearing and temperatures recovering to near just slightly below average. A strong ridge out of the Dakotas will continue to stream cool, northerly flow into the region Monday into Tuesday. If the sky remains cloud free, temperatures have the chance (NBM suggesting 40% to 60%) to fall below 50 degrees north of Pittsburgh and along the ridges. Precipitation chances remain low (less than 30%) Monday through Wednesday given long range uncertainty of a developing disturbance. Long range models are suggesting a pattern shift (June 13th- June 15th) as a ridge axis builds and returns warm conditions to the region. The NBM 50th percentile is suggesting hot conditions Thursday into Friday as temperatures range in the upper-80s to low-90s. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... As expected, a broken cu field with VFR cigs has developed across the entire area thanks to convective temperatures being reached via daytime heating/mixing. Isolated to scattered showers have also continued generally along and north of I-80, with only minor impacts primarily limited to FKL/DUJ. Westerly winds have become breezy and are sustained at 10-15 knots with frequent gusts up to 25 knots being observed at most terminals as of the 17Z obs. Expect these ongoing conditions to continue through the remainder of the afternoon, though the coverage of showers north of I-80 should gradually taper as drier boundary layer air begins to make its way into the area limiting moisture and instability. The cu field dissipates and winds settle after sunset with the loss of daytime heating and mixing. Light winds and VFR conditions then prevail overnight into Saturday as weak high pressure briefly builds into the area. Winds could start gusting 15-20 knots again with the onset of daytime heating/mixing after 15Z Saturday, but overall winds should be weaker and gusts less frequent than today. .Outlook... Scattered showers and associated restrictions return Saturday night through Monday as another disturbance moves through the Great Lakes region. High pressure brings widespread VFR back to the area Tuesday. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Hefferan NEAR TERM...Frazier SHORT TERM...Hefferan/Frazier LONG TERM...Hefferan AVIATION...Cermak