textproduct: Buffalo

SYNOPSIS

A strong cold front will rush through the region this morning and strong winds will become westerly today. Rapidly falling temperatures below freezing may create icy conditions. Accumulating lake effect snow will develop east of the lakes through tonight.

NEAR TERM /THROUGH TONIGHT/

A strong, 983mb low over north-central Ontario will move northeast into Quebec today. A strong cold front extends into Ohio and is rapidly moving east early this morning. Mild weather will reside across the forecast area for a few more hours, with gusty, southerly winds out ahead of the cold front. A plume of moisture is located ahead of an advancing, negatively tiled 500mb trough and will support rain showers across the region this morning.

Rain showers have weakened a low level inversion across the region overnight and early this morning. Gusty downslope winds will continue ahead of the front this morning, however the magnitude will be less. The High Wind Warnings have been converted to Wind Advisories and south winds 20 to 30 mph with gusts up to 50 mph are expected across the region and ahead of the front this morning. A swath of steady rain along the cold front will move from west to east across the forecast area this morning. A fine line of enhanced reflectivities is apparent on radar, and a brief period of moderate to heavy rain is possible with the frontal passage. Winds will veer to the southwest-west behind the front and wind gusts up to 50 mph are expected, especially across the Niagara Frontier and near the lakeshores. There will likely be a lull soon after the frontal passage this morning, however steepening lapse will increase momentum transfer and gusty winds will increase again late this morning through the afternoon. Wind Advisories will continue across the region.

Strong cold air advection will take place behind the front with temperatures rapidly falling below freezing from west to east into early afternoon. Surfaces that are still wet from rain and snowmelt may freeze leading to icy conditions. As cold air deepens, rain will transition to snow on the backside of the precipitation shield. A coating of accumulation is possible. Then, temperatures at 850mb will become cold enough to create lake induced instability on Lake Erie and Lake Ontario through tonight. Lake effect snow showers will likely develop northeast of the Lakes, then move south and focus east of the Lakes. In fact, little shear and increasing equilibrium levels through the DBZ will support intensifying snow bands east of Lake Erie and Lake Ontario this afternoon through tonight. Strong, westerly flow will create blowing snow and reduce visibility in any snow showers. An upslope component and colder thermal profiles will focus the greatest snow accumulation along the Chautauqua Ridge and Boston and Wyoming Hills east of Lake Erie and on the Tug Hill east of Lake Ontario. Winter Weather Advisories are in effect for these areas today through tonight.

SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/

High pressure slips out to sea with strengthening southerly flow ahead of an approaching cold front. With southerly flow picking up and warming mid-levels...any remaining lake effect snows or flurries will end early Saturday morning. After that...dry weather will prevail and warmer as temperatures rebound into the 30s to low 40s after a cold start to the day. It will also be quite breezy with winds gusting 30 to 35 mph at times.

Low pressure quickly races east passing by to the north of the upper Great Lakes late Saturday afternoon and evening. As it does so...it will send the first cold front east through the Lower Lakes, and then a secondary front on Sunday bringing a 'much' colder air mass into the region. With the main front, we will see some rain showers which then quickly transitions over to snow. Upslope areas east of the lakes may see some light accumulations by Sunday morning. With the arrival of the colder air (H850 T's -12C to -14C) we should see some measure of a lake response off both lake Erie and Ontario. That said...limited moisture and winds veering fairly quickly from the W to W-NW will 'likely' keep overall amounts fairly light, especially off Lake Erie.

Off Lake Ontario, we might see several inches across the Tug Hill as the band slowly sinks south and then potentially settles over Wayne, N. Cayuga, and southern Oswego by Sunday evening and night. Even so...amount south of Lake Ontario do 'not' appear overly impressive but it may all depend on an upstream connection to boost over all snowfall numbers. For now...will add a mention of some light to modest accumulating snows for Sunday and Sunday evening.

High pressure builds east into the Ohio Valley Sunday night and then into the Mid-Alantic on Monday. With falling EQ-levels lake snows will begin to diminish overnight off both lakes and then mostly wrapping up Monday morning. After that...dry weather will likely be found across much of the Lower Lakes by Monday afternoon with the ridge of high pressure overhead. Warm advection processes pick up Monday night as a warm front approaches which may bring a mixed bag of precipitation by Tuesday morning.

LONG TERM /TUESDAY THROUGH THURSDAY/

A weak low passing to the north is advertised to bring a wintry mix which then changes to all rain Tuesday as an attendant warm front crosses the region. A few rain or wet snow showers may linger into Tuesday night, before high pressure tries to dry things out mid week. A warm front associated with a system moving by to our northwest may then bring the chance of some rain and snow showers Christmas Eve night, transitioning to mainly rain showers from west to east on Christmas Day as warmer air works in. A brief window of dry weather Thursday and then the next system arrives with yet another mild wet day potentially for Friday.

AVIATION /07Z FRIDAY THROUGH TUESDAY/

A strong cold front will rapidly move across western and north- central NY this morning. A strong low-level jet will continue to support low level wind shear ahead of the front. Areas of rain will continue to move from south to north ahead of the front, then steadier rain will come through with the front this morning. A brief period of moderate to heavy rain is expected. Cold air will deepen behind the front and rain will mix with snow, before changing to all snow as temperatures rapidly fall today. Flight conditions will deteriorate to MVFR/IFR as the cold front approaches, then persist as snow showers continue across the region.

Lake effect snow showers will develop this afternoon east of the Lakes. Snow will persist south of Buffalo and south of Watertown with a mix of MVFR and VFR through this evening.

Windy conditions will persist through the TAF period. South winds will become westerly behind the cold front. Wind gusts up to 50 mph are expected through this evening.

Outlook...

Friday Night...Wind conditions continuing through the early evening with lake effect snow showers bringing local IFR east of the lakes.

Saturday and Sunday...MVFR/VFR in scattered light snow showers.

Monday...VFR.

Tuesday...MVFR/VFR with scattered showers.

MARINE

A dynamic system will pass across the eastern Great Lakes region today. South winds are expected to increase to gale force this morning. A cold front will move across the Lakes this morning, and winds will veer out of the west. Gales to 45 knots are expected on the eastern half of Lake Ontario and up to 40 knots on the eastern end of Lake Erie through tonight and gale warnings are in effect.

West to northwest winds will slowly diminish tonight, but small craft conditions are expected the better part of the weekend and into Monday.

BUF WATCHES/WARNINGS/ADVISORIES

NY...Wind Advisory until 1 AM EST Saturday for NYZ001>006-010>014- 020-021-085. Winter Weather Advisory from 1 PM this afternoon to 7 AM EST Saturday for NYZ006>008. Wind Advisory until 1 AM EST Saturday for NYZ007-008-019. Winter Weather Advisory from 10 AM this morning to 1 AM EST Saturday for NYZ012-019-020-085. MARINE...Small Craft Advisory until midnight EST tonight for LEZ020. Small Craft Advisory until 7 AM EST this morning for LEZ040-041. Gale Warning from 7 AM this morning to midnight EST tonight for LEZ040-041. Small Craft Advisory until 7 AM EST this morning for LOZ042>045. Small Craft Advisory until 3 AM EST Saturday for LOZ030. Gale Warning from 7 AM this morning to 3 AM EST Saturday for LOZ042>045-062>065. Small Craft Advisory until midnight EST tonight for SLZ022-024.