Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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463 FXUS61 KPBZ 112206 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 606 PM EDT Tue Jun 11 2024 .SYNOPSIS... Continued dry weather and a warming trend is expected through Thursday. Thunderstorms return for the day on Friday. There is medium to high confidence in a heat wave next week that may bring moderate to major heat-related impacts. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... KEY MESSAGES: - Cool and dry weather continues today with patchy fog overnight. -------------------------------------------------------------- On the backside of an upper low, north-northwest flow will allow temperatures to remain a few ticks below seasonable normals today and tonight. A passing shortwave axis circumventing the low may allow the maintenance of a broken to scattered cumulus to stratocumulus deck through this evening with weak cold advection enforcing saturation near the top of the mixed layer. Tonight, the loss of mixing and eastward progression of the low will allow cumulus coverage to decrease at the expense of some patchy cirrus overnight as upper moisture streams overhead. Despite this, high pressure will allow calm winds and efficient cooling, allowing for patchy valley fog. Fog is most likely east of the Pittsburgh metro and valleys. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... KEY MESSAGES: - Dry and near-to-above normal temperatures prevail through Thursday evening. - A rumble of thunder is possible overnight Thursday. ------------------------------------------------------------------- Dry and quiet weather is expected with upper ridging on Wednesday. Light to calm west winds and rising heights will keep Wednesday highs around five degrees above normal, and diurnal trends will allow lows to cool near seasonable normals. Patchy valley fog cannot be ruled out Wednesday night. Thursday, the high will move east and a disturbance will pass to the north, allowing for a light southwest winds and a further push of daytime highs around ten degrees above normal. An approaching disturbance overnight will result in increasing cloud cover or perhaps a rumble of thunder by late Thursday night along and ahead of a passing cold front. CSU MLP hints at severe potential, but with overnight profiles, the threat should remain mostly elevated before daybreak save any stronger storms. Mid- level dry air suggests that hail and winds will be the primary threat, by low probability through 8am Thursday. && .LONG TERM /FRIDAY THROUGH TUESDAY/... KEY MESSAGES: - Warm, dry conditions are expected Thursday. - Long range models are hinting that thunderstorm chances return Friday, there is a chance that a few storms could be strong to severe. - Models have been consistent that hotter conditions are favorable late week into early next week. ------------------------------------------------------------------- The better chance for showers and storms will occur along the cold front itself as it pushes through the area during the day Friday. Probability of organized convection (500 J/kg and 30kts of effective shear) is 20% to 40% Friday evening with this noted disturbance, meaning there is some low-end potential for a few storms to become strong or severe. Long range guidance has been consistent that a ridge axis will build across much of the central and eastern CONUS thereafter through the weekend and into the following week, bringing warm and humid conditions to the area. There is a growing concern that significant heat will be possible, especially as we get into early next week, with NBM probabilities for high temps reaching 95+ degrees on Monday continuing to run around 50% or greater. The highest probabilities for impactful heat are noted across eastern OH and the valleys and low elevations of western PA, including urban centers like Pittsburgh where the heat island effect typically leads to locally warmer temperatures compared to surrounding areas. There are some areas that are currently forecast to reach heat indices of 100F by Monday afternoon. If this trend in guidance continues, heat impacts will need to be closely monitored and headlines may need to be considered. && .AVIATION /22Z TUESDAY THROUGH SUNDAY/... Northwest winds will mainly remain light through the evening and overnight. A few gusts up to 15 knots at times can`t be ruled out. Drier air will begin to infiltrate the region tonight with clearing skies expected. Isolated fog development is possible tonight but is not expected to be widespread and mainly confined into the valleys, LBE may be impacted. For Wednesday, VFR conditions persist after fog dissipation between 12Z and 14Z. .Outlook... VFR conditions are expected under building high pressure through Thursday. Restrictions in showers and thunderstorms return early Friday with another passing disturbance. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Milcarek NEAR TERM...Rackley/Milcarek SHORT TERM...Milcarek LONG TERM...Cermak/Milcarek AVIATION...Hefferan/Shallenberger