836 FXUS61 KBUF 102018 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 418 PM EDT Wed Oct 10 2018 .SYNOPSIS... Unseasonably warm and humid conditions will remain over the area through tonight. Chances for showers and storms increase tonight ahead of a strong cold front that is expected to cross the area Thursday. Dramatically cooler temperatures will move into the area Friday through early next week. && .NEAR TERM /THROUGH THURSDAY/... High pressure resides well off the Mid-Atlantic coastline late this afternoon while a large upper-level ridge persists across the Northeastern states. This has pushed the northern jet stream well north into Canada. A warm and humid airmass will continue to produce well above normal temperatures for mid-October across Western and North-Central NY. Temperatures are well above normal late this afternoon, running in the low to mid 80s in most areas and the upper 70s across higher elevations. Subsidence has weakened some and a cumulus field has managed to form. An isolated instability shower can't be ruled out late this afternoon. The heat will come to an end soon as a cold front approaches the Lower Great Lakes. Low pressure is currently across Wisconsin this afternoon while an associated cold front lies near the Mississippi Valley. A southerly flow will continue tonight as the cold front swiftly moves eastward into the Ohio Valley. A 30-40kt LLJ will arrive tonight and showers are expected to move across the forecast area from the Western Southern Tier to the North-Country over the course of late this evening into the early morning hours. This will be the first round of rainfall across the region with basin average amounts near a tenth to a quarter inch. The increase in forcing by the nose of the LLJ and a small amount of instability will also increase the risk of a isolated thunderstorm late tonight. A mild night expected with low temperatures only reaching the mid to upper 60s. Those out and about tonight will notice it get increasingly muggy as a tropical airmass moves into the forecast area. PWATS will be at their climatologically maximum for mid-October and freezing levels near 14k feet. The cold front will be near the NY Lake Erie shoreline at 12z Thursday. The parent closed mid-level low will be moving east-northeast across the Upper Great Lakes and International border at this time. Although scattered showers will be across the forecast area early Thursday morning, a second round of widespread showers is expected ahead and along the cold front Thursday. These will spread from west to east across the forecast area. Due to the time of day, instability will be minimal as the front moves across Western and North-Central NY Thursday morning. Showers and a slight chance of thunderstorms are expected. As noted above, the air will be tropical-like and heavy downpours are possible. Another round of basin average amounts of a tenth to a quarter inch are expected. Higher amounts possible in a thunderstorm or strong shower. High temperatures will be reached in the morning across Western NY and around noon- time for the North Country. Temperatures will reach the low 70s during this time. Temperatures will likely be in the low 60s by late afternoon across the Niagara Frontier and Western Southern Tier. Cold air advection will occur behind the front Thursday morning and afternoon. Gusty winds 10 to 20 mph with gusts up to 30 mph expected behind the front. Low-level moisture will likely persist so expect a mostly cloudy day. Clearing will likely occur across the Niagara Frontier by evening. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... Thursday night and Friday...an upper level trough will be moving SE into the Dakotas with it's surface low near James Bay. A cold front tied to this low will already be well east of WNY with cold air advection in place. Meanwhile, Michael will be moving NE toward the Mid Atlantic coast but with little interest to WNY weather. Low level moisture will remain below about 5000' resulting in abundant cloud cover and possibly some lake effect sprinkles or showers ESE of the lakes. Dry air above this level should negate any significant rainfall amounts. Otherwise the main impacts through Friday will be the notably cooler weather with temperatures Friday struggling to top 50F. Friday night and Saturday...The upper level trough earlier over the Dakotas will move east across WNY during this time. This will allow moisture to increase throughout the profile, with at least a chance of showers everywhere, with the highest probability toward the Southern Tier. Lake effect showers should then linger into Saturday ESE of the lakes, with continued abundant cloud cover elsewhere. Saturday night...there is a possibility that some of the moisture may start to break up a surface ridge moves into the OH valley and then east through PA. If so, some clearing is possible with radiational cooling resulting in frost conditions inland from the lakes, with a freeze east of Lake Ontario. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... The longwave trough will reload across the Great Lakes early next week, with the leading shortwave and associated cold front moving through our region later Sunday and Monday. This will bring a chance of rain showers back into the region. Model guidance continues to suggest the possibility of a southern stream wave running northeastward along this frontal boundary and carrying some remnant moisture from Sergio into the Ohio Valley and Northeast States. If this were to occur, it would bring a better chance of more widespread rain late Sunday or Monday, but models continue to show plenty of run to run variability on this potential. Behind this system colder air aloft moves back into the region Tuesday with a chance of northwest flow lake effect rain showers. Temperatures will remain below normal most days through the weekend and early next week. The coolest days look to be Saturday and again Tuesday, when highs will struggle to reach 50 at lower elevations and stay in the mid 40s across higher terrain. Looking a little farther ahead, below normal temperatures are likely to continue through all of next week with a longwave trough well established across eastern North America. && .AVIATION /20Z WEDNESDAY THROUGH MONDAY/... A cumulus field has formed this afternoon and besides a rouge shower mainly outside of the terminals, it should remain rain free. A cold front will continue to approach the region tonight. A 30-40 kt LLJ will cross the region during this time. Showers are expected with ceilings lowering to MVFR levels by Thu morning. Although scattered showers will persist overnight, another round of widespread showers are expected Thursday morning ahead and along the cold front. An isolated thunderstorm is possible but confidence is low. Due to the high moisture content, heavy downpours are likely and may result in brief IFR cigs/vsbys. Once the front moves through from west to east Thursday morning, SSW winds 15 to 25 kts with gusts up to 35 kts are possible. The strongest gusts will be downwind of the lakes impacting KIAG, KBUF and KART Thu afternoon. Low-level moisture will hang around Thursday behind the front and MVFR/IFR ceilings are expected . Outlook... Friday...Areas of MVFR/IFR southeast of the lakes in lake effect rain showers, VFR elsewhere. Saturday...A chance of lake effect rain showers and MVFR early southeast of the lakes, otherwise VFR. Sunday...A chance of MVFR conditions in rain showers. Monday...A chance of MVFR/IFR conditions in rain showers. && .MARINE... High pressure will keep the winds and waves on the waters below marine headline criteria through this evening. A strong cold front will then cross the eastern Great Lakes Thursday. Southwest winds will become moderate to strong behind the cold front, and gradually veer to the northwest through Friday as much cooler air pours into the eastern Great Lakes. Small Craft Advisories are in effect for the NY shoreline of Lake Erie Thursday morning-Thursday night and the Lake Ontario shoreline Thursday late morning-Thursday night. These marine headlines may need to be extended into Friday. && .CLIMATE... A very warm airmass will remain across our region right through today. Below are the record temperatures this period. New record highs were set for Buffalo and Watertown yesterday, with Rochester falling a couple degrees short. Rochester did however set a new record warm minimum temperature for yesterday. With warm temps this morning, new record warm minimum temperatures are possible for today. Buffalo... Date Record High/Year Record Warm Minimum/Year 10/10 85/1949 65/1879 Rochester... Date Record High/Year Record Warm Minimum/Year 10/10 89/1949 64/1914 Watertown... Date Record High/Year Record Warm Minimum/Year 10/10 82/1949 62/1949 && .BUF WATCHES/WARNINGS/ADVISORIES... NY...None. MARINE...Small Craft Advisory from 8 AM Thursday to 6 AM EDT Friday for LEZ040-041. Small Craft Advisory from 2 PM Thursday to 6 AM EDT Friday for LOZ043>045. Small Craft Advisory from 11 AM Thursday to 6 AM EDT Friday for LOZ042. && $$ SYNOPSIS...HSK NEAR TERM...Apffel/HSK SHORT TERM...Zaff LONG TERM...Hitchcock AVIATION...Apffel/HSK MARINE...HSK/Smith CLIMATE...Thomas/Smith