Area Forecast Discussion
Issued by NWS Buffalo, NY

Current Version | Previous Version | Text Only | 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
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KBUF 261900 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 300 PM EDT TUE JUL 26 2016 .SYNOPSIS...
-- Changed Discussion --
High pressure will track across the Eastern Great Lakes tonight. Dry weather will persist until a weak cold front drops southward from Canada on Wednesday night bringing a few stray showers and thunderstorms to the North Country Wednesday night and Thursday.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
High pressure will build eastward across the eastern Great Lakes and into New England tonight with nearly clear skies through the night. The clear skies will allow temperatures to upper 50s to lower 60s across the Southern Tier and eastern Lake Ontario regions, and to the lower to middle 60s elsewhere. There may be some river valley fog forming across the Southern Tier. Skies will start nearly clear on Wednesday but a weakening cold front moving southward across Ontario will bring increasing high and some mid clouds to the region during the afternoon. There will be a low chance to slight chance of convection across the Saint Lawrence valley along the leading edge of the front, mainly late Wednesday night. High temperatures will climb well into the 80s on Wednesday, with upper 80s across the lake plains south of Lake Ontario, nearing 90 degrees at some spots.
-- End Changed Discussion --
&& .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
The weather will become increasingly unsettled across the region during this period...as a low amplitude trough over the Great Lakes will eventually support the development of at least one sfc wave over the Ohio Valley and Mid Atlantic states. While this scenario will lead to some showers and thunderstorms...especially over the Southern Tier...significant rains are not expected. The details... A weak cool front will sag south across our forecast area late Wednesday night and Thursday. Since there will be little if any synoptic forcing from this feature...any showers or thunderstorms will have to be generated from diurnally induced instability during the day Thursday. For the overwhelming majority of the forecast area though...this 24 hour period should be rain free. Mid level energy currently over the Mississippi Delta will drift north and eventually get picked up by the westerlies Thursday night...at which time it will develop a wave along a stalled frontal boundary over the Ohio Valley. This will be part of the same front that limped through our region earlier in the period. In any case...the wave is expected to push east along the boundary...moving well south of our forecast area. While the bulk of the associated showers from this wave will be found over Pennsylvania...forcing from the sfc wave could produce a few showers over the Southern Tier and Finger Lakes regions. On Friday...the wave over Pennsylvania will gradually push off the New Jersey coast. While this will keep the bulk of the associated showers and thunderstorms south of the border...there will be the opportunity for scattered showers and thunderstorms over our region. Any such pcpn will remain focused on the Southern Tier and southern portions of the Finger Lakes. The synoptic forcing will exit our region Friday evening...so there will be a diminishing chance for any cppn over our forecast area with the bulk of the night being damp but rainfree.
-- End Changed Discussion --
&& .LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
The medium range guidance packages remain somewhat out of sync during this period...only coming together in their solutions as we come out of the weekend. This will result in relatively low confidence in the forecast for the weekend...which could be rather unsettled for parts of the area. The disagreement between the medium range ensembles comes down to the position of a wavy frontal boundary over the Mid Atlantic Region. Initially...this will continue to serve as a pathway for individual waves to cross from the Ohio Valley. The northern fringes of these features will enhance the opportunity for showers and thunderstorms over the Southern Tier...while areas further north will be more influenced from high pressure centered over eastern Canada. As we exit the weekend...the Canadian sfc high will become more dominant..moving further to the south over the Lower Great Lakes. This will encourage fair weather to return to all of the forecast area while temperatures will average just a few degrees above normal late July normals.
-- End Changed Discussion --
&& .AVIATION /19Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR conditions will persist through this TAF period as high pressure remains in control through tonight and early Wednesday. There may be valley fog across the Southern Tier, but should remain removed from KJHW to preclude any reduced visibility. There will be an increase in cloud cover on Wednesday as a weak cold frontal boundary drift south over the Lake Ontario basin and St. Lawrence River valley, then dissipates Wednesday evening. Outlook... Wednesday...Mainly VFR. Thursday...Mainly VFR with a chance of showers and thunderstorms. Friday through Sunday...VFR/MVFR with a chance of showers and thunderstorms.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Westerly winds will increase in strength to 15 to 20 knots on Lake Ontario, while slightly weaker in strength over Lake Erie. A small craft advisory will remain in effect for the eastern shores of Lake Ontario where winds will be strongest and likely reach criteria, while waves will mainly remain 4 feet or less. As high pressure builds across the eastern great lakes through Wednesday, winds and wave should remain well below small craft criteria into the beginning of the weekend.
-- End Changed Discussion --
&& .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory until 8 PM EDT this evening for LOZ045. && $$ SYNOPSIS...WCH NEAR TERM...WCH SHORT TERM...RSH LONG TERM...RSH AVIATION...WCH MARINE...WCH

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