Issued: 5pm on Thursday, October 14th 2021
Technical Forecast Discussion
Short Term (Thursday 10-14-2021 through Saturday 10-16-2021)
Our short term period starts out with an axis of 500mb ridge which is extending from eastern Canada all the way down to Gulf Coast states, which also includes our area, as of Thursday morning. Our position relative to the ridge has warm and humid southerly winds as surface warm front lifted north of our area earlier. Our area is not under the deepest moisture and we also lack stronger forcing so we will likely remain dry throughout Thursday, but there will be afternoon clouds from daytime heating. At this same time, we have broad area of trough, centered over the Rockies and Plains region, which is gradually moving eastward into most of middle portion of the country. As this trough moves eastward, two things will happen. First, the ridge over our area will start to shift eastward throughout the day on Friday and begin weakening. Second, another surface low pressure will start to develop along the base of the trough in Illinois and start to lift northward into northwest Ohio area and drag a cold front through our area by very early morning hours of Saturday. Out ahead of this front, significant warmth and high moisture will remain in place leading to moderate instability as CAPE values of 500-1500 J/Kg exist, and we will also observe a moderately strong LLJ with 40kts winds passing our area. Combination of these should lead to isolated storms forming which may lead to damaging winds as the greatest threat, but we cannot rule out chances of tornado as well, and Storm Prediction Center has placed Marginal Risk in place as of result for our area. As we progress later into Saturday morning, any precipitation and minor severe threat should come to an end as much colder air ushers into our region by this time. Our temperatures are expected crash down from near record warmth on Thursday/Friday to much closer to what our seasonable averages are for this time of the year. We will have clouds sticking around trough first half of the day before they decrease as surface high pressure moves in later in the evening hours. Our temperatures will be in low-mid 80’s for highs on Thursday and Friday and crash down to lower 60’s by Saturday. Lows will drop down from mid 60’s Thursday night, low 50’s Friday night, and lower 40’s by Saturday night. Overall Temperature departures during these 3 days will be about 10°F-12°F above normal
Long Term (Sunday 10-17-2021 through Wednesday 10-20-2021)
Long range period starts out with trough remaining over our region as of Sunday morning with main axis over central sections of New York and Pennsylvania. As we head later into the day on Sunday, the trough will eventually depart from our area by early morning hours of Monday, but our area remains under northwesterly flow downstream of the new ridge over the Plains despite the departures of trough and we will sustain cooler weather in our area for the Monday as well. By early Tuesday, our heights will start to rise once again as the ridge pushes into our area by this time, and this will allow moderations to our surface temperatures. The ridge will remain in our area through Wednesday as well, temperatures and humidity by that time will not nearly rise to level as its currently, but we will once again deal with temperatures which would be above normal for this time of the year. On surface level, the high pressure establishes itself over western Tennessee area by Sunday, and then heads over to central Appalachians region by Monday and remains there through Wednesday of next week. Temperatures will range from low-mid 60’s for highs with lows in lower 40’s for Sunday into Monday and then our we warm up into lower 70’s for highs by Tuesday and Wednesday while our lows rises into upper 40’s with dry conditions in place for us. Despite the overall cool down, our temperature anomalies continue to remain above normal by 2°F-4°F. Good news for us is true fall like weather is here to stay for some extended periods of time.
