FXUS61 KBUF 200621 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 221 AM EDT Wed May 20 2026 .WHAT HAS CHANGED... Minor changes made from the previous forecast. && .KEY MESSAGES... 1) A cold front will move across the region this morning, bringing a few showers followed by drier and much cooler weather to close out the work week. 2) Unsettled weather returns for the holiday weekend. && .DISCUSSION... KEY MESSAGE 1...A cold front will move across the region this morning, bringing a few showers followed by drier and much cooler weather to close out the work week. GOES water vapor imagery shows an upper level trough over east- central Canada this morning. An area of low pressure is located over central Quebec with an associated cold front stretching south across southern Ontario. A moist and mild airmass resides across the forecast area and scattered showers are possible early this morning. The front will move across the forecast area later this morning and drier and cooler air will filter into the region. Temperatures will fall through the daytime hours with high temperatures met early in the day. Temperatures are expected to be in the upper 50s to low 60s by late afternoon. An abrupt cool down is expected across the region through the end of the work week. Temperatures at 850 will fall to the single digits as high pressure builds across the region. Low temperatures will fall into the 40s tonight and Thursday night. A favorable set-up for radiational cooling is expected Thursday night, especially east of Lake Ontario and areas of patchy frost inland from Lake Ontario can't be ruled out. KEY MESSAGE 2...Unsettled weather returns for the holiday weekend. Ensemble mean 500mb heights indicate an upper level ridge building into the eastern Great Lakes region during the first half of the weekend. Following this, the pattern is expected to become zonal from Sunday through Monday. Deep southerly flow is expected to move into the region ahead of a warm front Friday night through Saturday. The chance of showers will increase from south to north across the forecast area Friday night through Saturday. This time period supports the potential for a widespread, soaking rain. Then, an upper level trough is expected to move north of the Great Lakes region Sunday through Monday, maintaining chances for showers and a few storms. Temperatures will get back to seasonal normals Sunday and Monday. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Showers will move across the forecast area overnight. Reductions in flight cats will be possible within any heavier showers to IFR VSBYs. Outside of showers, mainly VFR CIGs early this morning will lower to MVFR and then IFR through daybreak as a cold front crosses the region. Higher terrain LIFR will be possible at times closer to daybreak for a few hours. A low level jet will cause a few hours of LLWS from KIAG to KBUF & to KROC. Cooler and drier air will filter into the region behind the passing cold front. This will result in improving flight conditions after daybreak, with all terminals expected to be VFR by mid/late morning, with KJHW taking the longest for flight categories to improve. Outlook... Thursday through Friday...VFR. Saturday and Sunday...Potential for low end VFR/MVFR due to a low pressure system introducing rain to the region from the south. && .MARINE... A cold front will move across the eastern Great Lakes today. Northwest winds will increase on the Lakes today, with an uptick in winds on the eastern end of Lake Ontario. A Small Craft Advisory is in effect for this region through this evening. Winds will be lighter on Lake Erie, however may be enough to produce choppy conditions. Winds will then begin to relax as high pressure builds into the region, however a tight pressure gradient may produce choppy conditions on Lake Erie Thursday. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory from 11 AM this morning to 2 AM EDT Thursday for LOZ043>045. && $$ DISCUSSION...HSK AVIATION...SW MARINE...HSK