Growing concern for severe thunderstorms Thursday afternoon

Pattern Evolution

The weather over the next 24 hours will shift, leading to a favorable set up for severe thunderstorms Thursday afternoon.

An area of high pressure is moving through the region this morning, but a strong low over the central Plains is pushing warm air north through the Midwest and Ohio Valley.

The first clouds associated with this surge of warm air are already entering Western New York early this morning. Clouds will spread east through the morning and skies should become mostly cloudy for the afternoon.

A couple brief showers will also be possible during the latter half of the afternoon and into the evening. At first, most of these will probably evaporate before reaching the ground.

Temperatures will be warmer today as winds turn to the southeast, then south. High temperatures will generally be in the upper 60s. Wind speeds will be light.

Clouds and showers will linger into early Thursday morning as temperatures fall back into the 50s. Some breaks of sun are expected throughout Thursday morning as the warm front passes north. Temperatures will rise to the upper 70s and near 80 degrees by the early afternoon with muggy dewpoints in the upper 60s.

Severe Thunderstorm Overview

While our temperatures and humidity rise at the surface, wind fields aloft will become increasingly favorable for severe weather. An approaching cold front will then act as the trigger to fire storms up as low pressure moves to a position north of Lake Ontario.

Thunderstorm cells and small line segments will form a broken line that will drop east-southeast across the region during the mid to late afternoon hours.

Many severe weather parameters are high tomorrow afternoon. Even patterns I have seen in my own severe weather research, such as the position of the low pressure system, check out. All modes of severe weather will be possible, including tornadoes.

The set up for tornadoes is much better than it was on Sunday (no, there was not a tornado in Syracuse, for the record) and is even better than our April event that prompted a tornado watch for the area and produced several tornadoes in Pennsylvania.

This does not mean a tornado is a certainty, but it will be important to monitor these storms carefully and to take warnings seriously.

For my part, I will post my normal daily blog in the morning with a complete overview of the storm potential and different hazards. I will then do live blogging and/or live video throughout the duration of the event, keeping you informed with up to the minute information that will help you stay safe.

An isolated thunderstorm may be possible behind the primary line of storms as it races out ahead of the cold front. Any severe threat should diminish greatly after 8 pm.

A few showers will linger overnight with clouds hanging tough on Friday. Winds will turn back to the northwest with gusts Friday over 30 mph. This will lead to a cool day with highs in the low to mid 60s.

Memorial Day Weekend Weather

Saturday will be another active day across the Finger Lakes with a second round of severe weather possible.

The details this far in advance are still unclear, but at this early stage, at least the tornado threat looks lower. Still, strong wind fields aloft and warm, moist air at the surface, and another approaching cold front could lead to severe thunderstorms. Stay tuned.

Sunday and Monday will be much quieter. Sunday will start with some clouds before turning sunny. Monday will have sunshine and fair weather clouds. There will be a very small chance for a brief afternoon shower, but most areas look dry at this time.

High temperatures on Sunday will be around 70 degrees. Monday will be a couple degrees warmer with most areas in the low 70s.