textproduct: Binghamton

WHAT HAS CHANGED

Marginal risk of thunderstorms in Central New York to Finger Lakes this afternoon-early evening, was expanded to include into the Twin Tiers.

KEY MESSAGES

1) Scattered showers and thunderstorms are expected this afternoon through early evening from Central New York to the Twin Tiers. A few may contain damaging wind gusts.

2) With a rainy cold front slipping through the region Wednesday, cooler weather will prevail for the next several days. This could include patchy frost early Friday morning.

3) Disturbances will continue to pivot over our region this weekend into early next week, around a cold upper low in Canada. This will keep our weather cool and unsettled with occasional showers.

DISCUSSION

KEY MESSAGE 1... Warm and windy conditions continue this afternoon ahead of a cold front entering the region, with 70s to near 80 degree temperatures yet dewpoints only in the upper 40s-lower 50s. The wide dewpoint depressions will factor into the limited coverage of thunderstorms this afternoon, yet also point to the potential of strong gusty winds mixing down. Even in the absence of storms, wind gusts will frequently reach the 30s mph range, and so if a heavy convective cores can get established it would not take much to mix down damaging gusts beyond 40 mph. The Storm Prediction Center expanded the Marginal Risk of Severe Thunderstorms to not just Central New York-Finger Lakes but also into the Twin Tiers. The thunderstorm potential should quickly drop off tonight with the loss of daytime heating, and thus the severe potential likewise is much lower in the Wyoming Valley to Poconos where it will take deeper into the evening for any activity to reach. The air is also drier in those areas.

KEY MESSAGE 2... Despite the pre-frontal clusters of storms, more of the rain will occur along and behind the front as we go into Wednesday. Highs will be early in the day especially in the Finger Lakes, as the front gradually slips through the region. A pretty raw morning is anticipated with cooling temperatures and steady rain. While embedded thunder cannot totally be ruled out east of I-81, it is doubtful. All told we are anticipating rainfall totals of half inch to inch for most of the region, which including the initial batch of storms this afternoon-evening, may push parts of Central New York past an inch. That said, the rain will be spread out enough for flooding to not be a problem, though there will be the more typical standing water and mud in the poor drainage spots. The already elevated water levels of area lakes and rivers will remain so.

There should be enough mixing and/or waves of cloud cover Wednesday night to limit frost potential. However, we will be on the edge of a surface high Thursday night. If enough clearing occurs, patchy frost may be an issue in areas where the growing season has begun.

KEY MESSAGE 3... A large upper low will be centered over Eastern Canada late this week through early next week. In addition to keeping a feed going for cooler-than-normal temperatures over our region, multiple disturbances will also pivot around the low for chilly and unsettled weather. Though it will be dry much of the time, intermittent waves of showers can be expected during the Friday through Monday time period. In the latest model guidance, Saturday daytime, and Sunday afternoon-evening, appear to be the more likely windows for showers.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

In addition to at times gusty southwest winds, scattered showers and isolated thunder will move across the NY terminals this afternoon-early evening. Monitor TAFs closely as coverage of storms is limited and thus confidence for specific terminals is low. The pre-frontal clusters of showers and thunder are unlikely to reach KAVP. However, it will eventually join the remainder of terminals later tonight through Wednesday morning in the widespread rain and restrictions that develop behind the front.

Outlook:

Wednesday afternoon-early evening...Rain showers ending but ceiling restrictions will linger; then gradual improvement evening.

Wednesday night through Thursday night...Mainly VFR, though valley fog possible in pre-dawn hours each morning at KELM. Friday night through Sunday...Cool and unsettled period with intermittent chances for showers and restrictions.

FIRE WEATHER

Warm dry and breezy conditions continue this afternoon to early evening, ahead of an approaching front. Minimum humidity levels of mid 30s to mid 40s percent range will be realized in Northeast Pennsylvania and parts of Central New York, especially the Poconos to Catskills. Wind gusts will also frequently reach 25 to 35 mph. However, a wetting rain is inbound. After scattered showers and isolated thunderstorms this afternoon through evening, steadier rain will occur behind the front late tonight into Wednesday. Forecast rainfall totals are between a half inch to inch for most of the area, with a few spots in Central New York even more than an inch.

BGM WATCHES/WARNINGS/ADVISORIES

PA...None. NY...Red Flag Warning until 7 PM EDT this evening for NYZ208.