textproduct: Buffalo

SYNOPSIS

A series of frontal boundaries will move across across our region through Thursday, causing several rounds of moderately heavy showers. A few rumbles of thunder are also possible overnight along with windy conditions through Thursday. Generally dry and seasonable weather will return on Friday before another slow moving frontal system will arrive with periods of rain this weekend.

NEAR TERM /THROUGH TODAY/

Low pressure tracking across Lake Superior overnight will push a warm front across the area overnight, followed by a cold front on Thursday.

Elevated instability will increase overnight with MUCAPE values 250 to 500 J/KG. There will be very little surface based CAPE as the surface cold front will approaches the region during the wee hours of the morning, but the quality of elevated instability will bring the risk for a few elevated storms. While the overnight timing is not conducive for severe storms, there will be a marginal risk due to the strong low level jet and the momentum from the approaching line of storms. The greatest risk of stronger storms will be west of the Genesee Valley.

Southerly winds will be gusty at times, with strongest gusts likely to occur between rounds of precipitation. Gusts will reach 50 to 55 mph from downsloping off the Chautauqua Ridge, and across higher terrain. Additionally tonight the southeast to south flow over the Tug Hill has the potential to downslope along the northwest face of the Tug Hill, with gusts up to 50 mph. Lower elevations including the lake plains will be breezy with southerly gusts 30 to 40 mph.

Thursday, the cold front sweeps through. Widespread showers Thursday morning, and perhaps a rumble of thunder with the front. The showers will taper off through the afternoon with the passage of the cold front, as deeper moisture pushing eastward. It will remain windy with southwesterly gusts northeast of Lake Erie and Lake Ontario possibly reaching 45 to 50 mph.

SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/

Albeit brief, we will see drier weather return beginning Thursday night for much of the forecast area which lasts through the day Friday. The only caveat to this dry forecast will be across the Southern Tier near the NY/PA line. This is where we might see an an isolated shower but only low end chances (< 30%) Thursday night as the front slowly sags southward and then stalls out across the Mid- Atlantic region. After that...all bets are off for a dry weekend as it's looking more and more like we will once again see chances for rain showers to return.

The stalled cold front across the Mid-Atlantic region returns north Friday night, and along with deep moisture (Pw values north of 1.2") streaming northward on the western flank of the 590 dm ridge will set the stage for another round of unsettle weather this weekend. The initial slug of showers w/possible embedded storms looks like it will arrive Friday night. This will occur as a weak wave and the associated warm front crosses the area as we head into Saturday. As it crosses, we could see a brief period of lighter (lull) shower activity or even drizzle late Saturday morning. However...this lull doesn't last long as the next wave (low) approaches quickly Saturday afternoon and then tracks along a mid-level thermal boundary oriented from SW to NE across the region. As this wave passes by the region, it will pull the semi-stationary front east along with the steadier and heavier precipitation as we head into Sunday.

Overall...initial QPF amounts from late Friday night through Saturday night range from 0.75" to 1.25" for locales east of Lake Ontario, and also counties found along the immediate south shore of Lake Ontario. Higher rainfall amounts will potentially be found south of I-90, with 1.25" to 1.75" possible, and some isolated spots of up to 2" across the Southern Tier. Given the anticipated or potential rainfall amounts expected over the area much of Western NY been placed in a Marginal Risk for excessive rainfall from 12Z Sat to 12Z Sun.

LONG TERM /SUNDAY THROUGH WEDNESDAY/

The active pattern will continue into the long term period with yet another sfc wave tracking along a slow moving front bringing a round of at least showers to much of the area on Sunday and Sunday night. Monday looks like it should be the driest day of the period between the departing sfc low and front from Sunday, and ahead of the next system that drops southeast out of Canada and across the Great Lakes Monday night through the rest of the period. Temperatures may be cold enough Monday night through Wednesday to support snow especially during the night time hours and over the higher terrain.

Temperatures for the period will remain below normal for most areas, especially for Monday and Tuesday behind the passing front on Sunday.

AVIATION /06Z THURSDAY THROUGH MONDAY/

While VFR conditions will be in place for the bulk of the region for the remainder of the overnight...a new swath of moderately heavy showers and possible thunderstorms will move across the region after 07z. Some of this activity could include brief periods of MVFR conditions.

There will also be gusty winds as a powerful LLJ enters our region. At 1.5 to 2Kft...50 to 60 knots of flow will be found and LLWS will be likely for all TAF sites during times when steady showers are in the area. Otherwise...winds should be mixed with sfc gusts in the vcnty of 25-30kts.

Areas of MVFR in cigs and vsby Thursday morning will improve during the afternoon hours with a partial clearing. It will be windy with southwest gusts to 35 kts.

Outlook...

Thursday night and Friday...Mainly VFR. Saturday and Sunday...Restrictions likely in scattered to numerous rain showers. Monday...Restrictions possible in scattered rain/snow showers.

MARINE

Strong easterly winds will turn southeast, then southerly and increase in speed on the lower Great Lakes overnight as a warm front lifts through. The strongest winds could be from Ripley to Dunkirk with some local downslope enhancement which could approach near gale force.

Winds will become southwesterly and remain elevated behind the passage of a cold front Thursday. Winds and waves will start to lower Thursday night as the pressure gradient relaxes, allowing for small craft conditions to end.

BUF WATCHES/WARNINGS/ADVISORIES

NY...Wind Advisory until 6 PM EDT this evening for NYZ007-008. Wind Advisory until 6 AM EDT early this morning for NYZ012>014- 019>021-085. MARINE...Small Craft Advisory until 6 PM EDT this evening for LEZ020. Small Craft Advisory until 10 PM EDT this evening for LEZ040-041. Small Craft Advisory until 6 PM EDT this evening for LOZ030. Small Craft Advisory until 11 PM EDT this evening for LOZ042-043. Small Craft Advisory until 2 AM EDT Friday for LOZ044-045.