Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 202010 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 410 PM EDT Sat May 20 2017 .SYNOPSIS... Rain chances will increase Sunday with the approach of a cold front. Temperatures will be at or slightly below seasonal averages for most of next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
-- Changed Discussion --
Scattering of the cloud deck and increasing moisture and instability will support convection over southwestern Ohio through this evening. The hi res models continue to suggest that this convection will not make it far into the forecast area, with limited instability and some capping aloft. Will maintain low chance PoPs through tonight, with increasing moisture supporting scattered showers through Sunday morning. Building upper ridge will shift eastward as low pressure in the midwest lifts northeastward toward the great lakes. Sufficient warming aloft and increasing cloud cover will support warmer than average low temperatures. Have slowed increasing PoPs for the overnight until deeper moisture and lift approaches with the advancing cold front.
-- End Changed Discussion --
&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
-- Changed Discussion --
Rain and thunder chances will increase rapidly into Sunday as the deepening upper low swings a cold front across the region by Monday morning. Deep moisture through the entire column and weak steering flow may allow for a brief period for slow moving/training storms Sunday afternoon until the boundary gets closer. That being said, there is some uncertainty to this, despite the rather high PWAT values based on climatology. Will leave HWO mention out at this juncture, with concerns mainly being locally heavy rain and poor drainage flooding. Severe threat appears to be minimal but non-zero with limited instability, modest shear, and warmth aloft. However, if we were to break out, i.e, have more sunshine tomorrow than currently projected, this threat could be slightly higher. Boundary will be east of the region by Monday morning but return southerly flow will quickly rebound values to near seasonal norms by Tuesday.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
Average-or-below temperature is forecast as broad upper troughing remains in place through the end of the week. Differences amongst the deterministic guidance suggest using a blend, given the placement differences in shortwaves and resolved surface lows through the period. Only small adjustments were made to the blend of guidance through the period.
-- End Changed Discussion --
&& .AVIATION /19Z SATURDAY THROUGH THURSDAY/... Stratus is lifting to a broken stratocu deck and expect cloud bases to raise through the afternoon as mixing strengthens. An isolated shower or storm could develop but probability is too low for inclusion in any TAF. Best shot appears at ZZV closer to the better instability. Diurnal cu will wane with sunset, however a canopy of broken mid and high clouds will invade from the west associated with upstream convection. This will offset any fog or stratus development overnight. As the cold front gets closer scattered showers are possible by daybreak in eastern Ohio, but a more concentrated area is predicted around early afternoon in ZZV than moving east through the mid and late afternoon hours over PA and WV. High confidence of a line of showers and storms developing and moving through. Confidence is a little lower in the precise timing at this juncture. MVFR conditions will accompany any shower or storm with the ones in the afternoon having a greater chance to drop visibilities to IFR for a short period. Winds from the east will slowly veer to the south by Sunday afternoon. Sustain speeds will be around 10 knots. .Outlook... MVFR and brief IFR restrictions are expected Sunday night with a passing cold front. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.