Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
708 FXUS61 KPBZ 211928 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 228 PM EST Tue Nov 21 2017 .SYNOPSIS...
-- Changed Discussion --
A cold front will bring the next chance for precipitation tonight. Dry weather and generally below average temperatures are expected for the remainder of the week.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Gusty southwest winds will continue into the evening hours as a well-mixed boundary intersects roughly 35 kts of momentum off the deck. This should quickly subside as stabilization increases into the later hours of the evening. A cold front will then start its slide toward the area, bringing first high clouds into the area. A rather dry air mass is in place over the area, however a fairly narrow corridor of saturation looks to coincide with the frontal passage overnight. Upper level jet streak right entrance region dynamics should sufficiently couple with differential PVA and adequate frontogenesis such that categorical PoPs have been favored from Pittsburgh northward. Saturation depths do look to peter out rather effectively in the wake of the front, so cold advection snow showers are unlikely to get out of hand after the changeover before they shut off. This will likely even be the case up north along and north of I-80 as well as in the upslope areas. Thus, a grand total of 0.10-0.15 liquid equivalent combined with a changeover and fairly inefficient SLRs seems unlikely to yield anything more than an inch of snow, even in the most efficiently accumulating areas. Drier air will quickly return post-frontal, and this should end precipitation over much of Ohio before morning. However, cold advection will yield overnight lows near freezing over most of PA/WV/MD, and in the upper 20s in Ohio. Fries
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
-- Changed Discussion --
Cold advection and upslope snow showers should quickly fade on Wednesday as northwesterly lake flow should turn more continental. A cold mid-week also looks to likewise moderate as the wind loses the northerly component. However, upper troughing will remain in place, which will preclude substantial warming, thus temperatures looks to slowly migrate toward the 40s through the remainder of the week. But with continental flow, dry conditions should remain through the holiday. Fries
-- End Changed Discussion --
&& .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
Ensemble forecasts are showing the next cold front dropping through the area on Saturday with fairly weak support for precipitation, followed by the next trough setting up over the Eastern CONUS. This will hold into the beginning of next week. A cold surface high is expected to build back in late Sunday into Monday.
-- End Changed Discussion --
&& .AVIATION /19Z TUESDAY THROUGH SUNDAY/... VFR conditions will carry through the late evening. Strong southwesterly surface flow will gradually dissipate after sunset as the strong low-level jet exits to our east. Clouds will increase overnight in advance of an approaching cold front. Ceiling drop to MVFR is expected in concert with the onset of rain along the front. Cold air pouring in behind will lead to a transition to snow and possible visibility restrictions in the heaviest, mainly northern ports. Ceilings may drop to IFR for a time at FKL/DUJ in the pre-dawn hours, but are largely expected to stay MVFR elsewhere. Sustained cold advection will keep MVFR ceilings in for much of the day Wednesday. Any improvement to VFR would likely come to ZZV or HLG first where moisture will begin to erode. Passage of the front will shift winds to west-northwesterly through the balance of the TAF period. .Outlook... The next chance for restrictions is forecast with an early Saturday 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.