064 FXUS61 KBUF 102349 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 749 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/... Low pressure across Michigan this evening will track into southern Ontario through Thursday. A strong cold front extending southward from this low this evening will approach the region tonight and move across the area Thursday morning. 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 few thunderstorms east of the Genesee river late tonight. Otherwise, a mild night is expected with low temperatures only in the mid to upper 60s. Those out and about tonight will notice the muggy and tropical airmass with PWATS 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/... This period will open with a mid level wave and its attendant surface reflection passing by to our north across Central Ontario and Quebec Sunday and Sunday night...with its trailing cold front passing through our region between late Sunday and Sunday night. Out ahead of the front...Sunday should be mainly dry aside from some possible leftover lake effect rain showers northeast of the lakes...with a modest shot of warm air advection out ahead of the front also helping to push high temps back up into the mid to upper 50s. Sunday night shower chances should at least increase somewhat as the front passes through our region...though the exact coverage of these remains in question with the latest GEM suggesting a round of showers for all... the ECMWF completely dry...and the GFS lying in between these two extremes. Given the resulting forecast uncertainty...have elected to scale back a bit on the likely PoPs previously in place areawide... with these now restricted to the northern half of our area...where the front will have a little better support from its parent waves. In the wake of the cold front...the medium range guidance continues to suggest that a southern stream wave/possible remnants of Sergio may ripple northeastward along the boundary and bring our region another shot of showers sometime in the Monday-Monday night time frame... though considerable run-to-run and model-to-model variance also still persists in the timing and placement of this wave. Following a general consensus would suggest a slower overall approach and passage of this feature...and have trended the forecast in this direction with the bulk of its showers now indicated for late Monday and Monday night. Following the passage of this feature...another shot of colder but relatively dry air will then build across the region late Monday night and Tuesday...with some nuisance-type lake effect rain showers again becoming possible downwind of the lakes. As for temperatures...the twin shots of cold air advection behind the initial cold front and secondary southern stream wave will send temperatures back to below normal levels for both Monday and Tuesday...with highs both days only expected to range from the upper 40s across the higher terrain to the lower 50s across the lower elevations. After that it looks like a case of lather...rinse...and repeat for Tuesday night and Wednesday as another mid/upper level trough axis passes across the Great Lakes and Northeast...with its attendant surface low passing by to our north across Ontario/Quebec and pushing another cold front through our region. This next system should also be accompanied by a round of at least scattered showers as it passes through our area...with its attendant cooler temps aloft possibly also supporting some areas of lake enhancement. Otherwise temperatures will remain below normal...with highs on Wednesday again mainly in the upper 40s to lower 50s. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... A cold front will approach the region tonight with a 30-40 kt LLJ moving into the region ahead of this front tonight. This will result in showers, along with lowering ceilings. For most areas, cigs will lower to MVFR, with patchy IFR cigs just ahead of the cold front. 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...JJR AVIATION...Apffel MARINE...Apffel/HSK/Smith CLIMATE...Thomas/Smith