A weak area of high pressure is sliding over central New York early this afternoon, providing us with sunshine and dry weather for the rest of the day. Meanwhile, a frontal boundary remains draped from northern Ohio west through to the central Plain States. Along this boundary multiple centers of low pressure are evident as well.
By early evening, high pressure is forecast to slide to our southeast, thus giving Central New York our pick day of the work week. Meanwhile, the frontal boundary to our west will become very active with numerous showers and severe thunderstorms developing later this afternoon and evening. In fact, a major and widespread severe weather event is likely later today and tonight across the Lower Great Lakes and Mid-west regions.
It’s expected that low pressure will continue to induce numerous showers and thunderstorms as it travels east through the Mid-west tonight to an eventual position near Toledo, Ohio by Thursday morning. While all of this is unfolding, a separate area of energy in the upper atmosphere will be diving southeast through Canada and should be in the Upper Great Lakes by early tomorrow. Computer models indicate that the two systems will merge sometime later Thursday and become one larger storm.
How this first system behaves and how the two systems eventually interact will have large implications on the timing and intensity of the rain that occurs in Central New York. Right now, there unfortunately remains a fair bit of uncertainty as to where the heaviest rain falls. Some computer models give the Syracuse area greater than three inches of rain by Friday morning. Other models, give half that amount and also differ on the arrival and departure of the rain.
Often times, when low pressure is induced from thunderstorms, as is the case from the Mid-west system, computer models are challenged with handling the initial development of the thunderstorms (intensity and placement) and can mishandle their evolution. Consequently, if this happens, this can lead to subsequent errors in the placement and intensity of how the thunderstorms, and ultimately, low pressure system behave down the line. To put simply and in short, small errors at the start of the forecast period can lead to large errors down the line. Thus, when the thunderstorms actually develop later today over the Mid-west, computer models should begin to come up with a more reliable consensus and forecast.
Given the recent wet weather, it should be noted that flooding may be a real concern tomorrow and Friday, especially for areas that see the heaviest rain. Right now, flood watches are in effect for the counties south of Syracuse Thursday into Friday as these are the areas that have the best chance of seeing the heaviest rain.
No matter how Thursday unfolds, low pressure will be moving off the East Coast Friday with cooler and eventually drier air mass poised to move into the region, though leftover showers are still in the forecast Friday.
Our weather looks to be generally sunny and dry Saturday. We are getting a better handle on Father’s Day and given there seems be a push of warmer, more humid air heading our way from the Great Lakes we’ve at least put in a lower chance of a shower or thunderstorm to end the weekend.