We continue to monitor the possibility of a significant and widespread severe weather event that may be unfolding across our area tomorrow afternoon into tomorrow evening. Today's computer model runs continue to suggest that mid to upper level wind speeds will be increasing dramatically overnight tonight and into the day tomorrow....thanks to the approach of a feature known as a jet "streak". A jet streak is an area of enhanced wind speeds that travels through the main branch of the jet stream, and the jet streak that is approaching us for tomorrow is a particularly potent one for this time of the year with wind speeds forecast to reach 80kts (92 mph) or more! As this jet streak travels overhead later in the day tomorrow it will cause large scale rising motion in the lower atmosphere, resulting in the development of showers and thunderstorms. In addition, the models continue to suggest that winds will be veering (turning clockwise) quite significantly with height, which only increases the threat of severe weather. All in all, it is looking like it could be a rather active day around here.
Of course, not everything in the weather world is always a guarantee (we wish it was!) and this is by no means set in stone. The extent of severe thunderstorms tomorrow afternoon and evening will depend largely on the amount of sunshine we receive in the morning. Sunshine increases the probability of thunderstorms because it heats up air parcels near the ground, increasing their buoyancy and allowing them to rise more easily. As the air parcels then ascend into the cooler atmosphere, they cool and condense into clouds and potentially thunderstorms. The more sunshine we receive tomorrow morning, the more buoyant the air will become, and the higher the threat of thunderstorms and severe weather will be.
If severe thunderstorms develop tomorrow afternoon, the greatest threat will be for damaging straight-line winds and large hail. Thunderstorms will first develop in western sections of the area (Steuben County, Tioga County PA) most likely between 1PM and 3PM, then travel eastward across the rest of the remainder of the area as the afternoon progresses. The greatest threat in and around the Binghamton area will probably be from 5PM to 8PM. More updates may be forthcoming if the situation warrants.