549 FXUS61 KBUF 140223 AFDBUF Area Forecast Discussion National Weather Service Buffalo NY 1023 PM EDT Fri Mar 13 2020 .SYNOPSIS... Winds will gradually diminish tonight and Saturday as strong low pressure moves east across northern Quebec. High pressure will build into the region this weekend and into early next week with a period of quiet and chilly weather. Somewhat warmer temperatures will arrive Tuesday just ahead of a cold front which may produce a few showers across the region. && .NEAR TERM /THROUGH SATURDAY NIGHT/... IR satellite imagery shows many areas have cleared nicely this evening, with most of the clouds now confined to the eastern Lake Ontario region and Finger Lakes. Most of the clouds overnight will continue to reside east of Lake Ontario from limited lake effect clouds on westerly flow and upslope flow. Late tonight and early Saturday boundary layer flow will veer, which may spread some additional lake effect clouds to areas southeast of the lakes. Strong low pressure will continue to move east across northern Quebec overnight. Winds aloft remain fairly strong, and the pressure gradient fairly tight. That said, the mechanisms to mix stronger wind gusts down to the surface have broken down in most areas. Cold advection is weakening, the region of strong isallobaric pressure rises is moving well east of our area, and diurnally driven mixing ended after sunset. It will remain quite breezy tonight, especially for areas along the Lake Ontario shore and eastern Lake Ontario region where gusts may still reach 40 mph. Otherwise for the rest of the area, gusts in the 20 to 30 mph range this evening will slowly back off overnight. Canadian high pressure will build southeastward into southern Quebec and New England Saturday and Saturday night. Little in the way of sensible weather is expected across western and north central New York, as the high drifts through southern Canada and makes its effects felt locally. Some cooler temperatures are expected with highs Saturday in the upper 30s to lower 40s and lows Saturday night in the 20s with some upper teens for the eastern Lake Ontario region. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... The strong Canadian high will remain overhead Sunday before slowly moving southeastward and drifting off the New England coastline Monday. The presence of the high will provide ample dry air and subsidence which will allow for dry weather and quiet conditions Sunday and Monday. The position of the high on Sunday will set up general northeasterly flow over the region which will keep our temperatures just below average. Daytime highs should peak in the mid to upper 30s. The coldest temperatures this weekend will occur Sunday night as the core of the high pressure system is in close proximity allowing for radiational cooling to set up. Overnight lows on Sunday appear to be in the lower teens in the North Country east of Lake Ontario and upper teens and low 20s elsewhere. Though Monday will have a chilly start, temperatures will rebound to normal by the end of the day as the high shifts southeastward toward the New England coastline. This will put the region under southerly flow, allowing for the return of milder air into the region. High temperatures Monday appear to reach the low 40s east of Lake Ontario and mid to upper 40s elsewhere. The exiting high pressure will settle across the western Atlantic, while a weak low pressure system will make its way across northern Ontario and Quebec and pivoting its trailing cold front eastward across the Great Lakes Monday night. While being sandwiched between the two systems, southerly flow will continue which will keep the milder air in the region. Chances for showers increase as the cold front approaches the region Monday night. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Models are in good agreement with a cold front crossing our region Tuesday. Moisture is not plentiful along the front...but we will have at least a low chance PoP everywhere in respect to the frontal passage. Our area will quickly dry out Tuesday afternoon and evening behind this cold front. Thermal profiles suggest mainly plain rain showers...though colder air pushing into the North Country Tuesday night may end the precipitation with a few wet snowflakes. Behind this front a large, dry Canadian surface high will cross our region. With the proximity of this high, have pushed down dewpoints from continuity Wednesday and Wednesday night, and with cold air advection a bit stronger, surface temperatures Wednesday may not climb out of the 30s. The cooler air temperatures will also keep RH values in check...and brilliant sunshine will be upon the region through the afternoon hours. This dry airmass should keep our region dry through Wednesday night. Behind this surface high Thursday, a southerly return flow will increase moisture...with chances for rain showers Thursday. The greater chance for rain showers will be Friday as a warm front from an Ohio Valley storm system extends over our region. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... Wind gusts will continue to steadily diminish tonight. Gusts will still reach 35+ knots along the Lake Ontario shore and east of Lake Ontario overnight. Otherwise for the rest of the area, the 20 to 30 knot gusts early this evening will continue to diminish overnight. Fairly widespread VFR CIGS in stratocumulus this evening will partially clear in most areas overnight. The one exception will be east of Lake Ontario where some lake effect clouds will persist. Boundary layer flow will become more WNW Saturday morning, which may allow for a brief increase in lake effect clouds and MVFR to lower end VFR CIGS for a larger area south and southeast of the lakes. The lake effect clouds will clear in the afternoon, only to be replaced by increasing mid/high clouds to the north of a weak wave moving through Pennsylvania. Outlook... Saturday night through Monday...VFR. Tuesday...MVFR with a chance of showers. Wednesday...VFR. && .MARINE... Deep low pressure just south of James Bay will keep a tight pressure graident across the lakes tonight. A period of low end gales is expected on the eastern half of Lake Ontario tonight. Elsewhere, sustained winds to 30 knots are expected with a few gusts to gale force. Winds and waves will gradually subside into later tonight into Saturday, but may not drop below Small Craft criteria until late Saturday night or Sunday morning on eastern portions of Lake Ontario. && .TIDES/COASTAL FLOODING... Westerly winds will increase to low-end gale force on Lake Ontario tonight, resulting in increased wave action along the eastern and east-southeastern shore of the lake. A Lakeshore Flood Warning remains in effect for Jefferson, Oswego and N. Cayuga counties into Saturday morning. && .BUF WATCHES/WARNINGS/ADVISORIES... NY...Lakeshore Flood Warning until 8 AM EDT Saturday for NYZ005>007. MARINE...Small Craft Advisory until 8 AM EDT Saturday for LEZ040-041. Gale Warning until 5 AM EDT Saturday for LOZ063>065. Small Craft Advisory until 5 AM EDT Sunday for LOZ042-043. Small Craft Advisory until 2 AM EDT Sunday for LOZ045. Small Craft Advisory until 8 AM EDT Sunday for LOZ044. && $$ SYNOPSIS...Hitchcock/TMA NEAR TERM...Hitchcock/TMA SHORT TERM...EAJ LONG TERM...Thomas AVIATION...Hitchcock MARINE...Hitchcock/TMA TIDES/COASTAL FLOODING...Apffel/TMA