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 152331 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 731 PM EDT Sun Apr 15 2018 .SYNOPSIS... Rain, will overspread the region by this evening and continue overnight ahead of a cold front. Behind the front, showery precipitation and colder temperatures will dominate through the early part of the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 445pm update...only minor changes to previous forecast. Updated PoPs for the evening hours in line with latest hires guidance and radar trends. Temperatures were also slightly adjusted to better portray current conditions. Previous discussion... Elected to expand the Flash Flood Watch to encompass eastern Ohio and the northern WV panhandle. Model consensus of a band of 1.5 to 2.5 inch QPF, perhaps locally higher, was getting harder to ignore. The western counties fall under the right entrance region of a 120-140 knot upper jet during the late afternoon and evening as the trough tilts. Layered frontogenesis and deformation will also be present, along with anomalously high PWAT values of 1.3 to 1.4 inches. Although flash flood guidance values are fairly high in this area, felt that rain rates may support at least isolated flooding concerns. The watch is maintained over the original eastern counties as well where a period of training heavy showers is also possible. The cold front will arrive in the western counties this evening and depart to the east during the predawn hours. Steadier rain will end, to be followed by more showery precipitation as the upper low makes its way into the Ohio Valley. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... The upper low will swing across the region behind the boundary on Monday. Periodic shortwaves will then rotate through in the troughing pattern through Tuesday, producing showery precipitation. A mix with and change to snow is still figured first along the higher ridges Monday, and then areawide Monday night into Tuesday morning. Boundary layer warming should allow rain to become dominant again in the lowlands Tuesday afternoon. Any snow accumulation should be minor given the time of year and the antecedent warm conditions. Below normal temperatures will persist. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Precipitation will linger into Tuesday evening north of Pittsburgh, with a brief period of dry weather late Tuesday night into Wednesday in advance of low pressure moving into the region from the Plains. The low should pass just north of the area Thursday morning, sweeping a cold front through. While a flake can`t be ruled out north of I-80 with the initial precipitation, at this point it appears that all precipitation Wednesday night and Thursday would fall as rain. Before precipitation ends Friday, all locations will have a chance for snow Thursday night into Friday morning. High pressure building across the Great Lakes should then keep weather dry into the weekend. Temperatures will be below normal through the extended forecast. && .AVIATION /00Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
MVFR to local IFR conditions and showers should continue tonight with a crossing cold front. A low level jet in place should also result in gusty SE wind through this evening until it departs overnight. A wind shift to the west, with gust of 20-25kt are expected after FROPA through the rest of the TAF period. An upper low crossing the Upper OH Valley region should maintain MVFR and sct showers Monday. OUTLOOK... Restrictions are expected through Tue under upper troughing. Restriction potential returns with a Thu cold front.
-- End Changed Discussion --
&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...Flash Flood Watch until 4 AM EDT Monday for MDZ001. OH...Flash Flood Watch until 4 AM EDT Monday for OHZ039>041-048>050- 057>059-068-069. PA...Flash Flood Watch until 4 AM EDT Monday for PAZ020-021-029-031- 073>076. WV...Flash Flood Watch until 4 AM EDT Monday for WVZ001>004-012-021- 509>514. && $$ is the U.S. government's official web portal to all federal, state and local government web resources and services.