Current Forecast Meet the Forecaster

Issued: 4pm on Wednesday, November 17th 2021

Technical Forecast Discussion

Short Term (Wednesday 11-17-2021 through Friday 11-19-2021)

Short term period is starting out with presence of the ridge directly overhead while a trough moves and expands over northern plains region which will gradually move eastward and intensifying a bit at same time. On surface level, we are dealing with a nice fetch of southwesterly flow behind the surface high pressure in southeastern U.S. which will allow our temperatures to warm up several degrees above normal with breezy conditions as well during daytime hours on Wednesday. Wind speeds will be in 10-20mph range with gusts nearing 30mph. As we move through Wednesday night into Thursday morning, the ridge continues to push eastward and the trough from west immediately takes hold of our area by Thursday morning. Arrival of the trough will be marked by a strong cold front as it would be extending down along trough’s leading edge, courtesy of low pressure over northern Ontario. Look for rain to develop out ahead of the cold front and move through our area some time between very early morning hours into early afternoon period on Thursday with rain totals between 0.25″-0.50″ inch. With early passage of cold front, our actual high will peak in upper 50’s just past midnight and we will cool down into low-mid 40’s during afternoon hours on Thursday. Look for clouds to hang around through the evening hours before it breaks down by midnight. This trough is expected to be rather short lived as it exits our area by Friday afternoon with another area of upper level ridge developing in middle of the country. This ridge will be weaker this time, but will eventually push into our area by late Friday evening hours. This pattern on surface will translate to strong surface high moving into Illinois area by Friday morning with clouds clearing for our area under continued chilly conditions because we still would under the northerly flow from the high pressure. Looking at our expected temperatures, we will start out on a warm note on Wednesday with high’s in lower 70’s for Wednesday which drop down to a early high of upper 50’s on Thursday due to passage of cold front and finally bottom out to mid 40’s for Friday. Low temperatures on Wednesday night will fall through upper 40’s with lows further dropping into mid-upper 20’s Thursday and Friday night. Our overall temperature anomalies during this period will be 1°F-4°F above normal.

Long Term (Saturday 11-20-2021 through Tuesday 11-23-2021)

Long term period will resume with weak upper level ridge persisting in our area through all of Saturday before it starts to further weaken and move eastward into early Sunday as another potent trough starts to develop. High pressure will still dominate our area on Saturday so we will one more clear day with seasonable temperatures. This potent trough will develop over northern Minnesota area which would allow formation of surface low pressure over U.P. Michigan area as of result. As we move through the day on Sunday, this trough will move eastward while digging southward at the same time and rainfall out ahead of the strong cold front will overspread much of Ohio Valley region before precipitation clears out of our area by Monday morning. There is still some disagreements on the exact specifies, but the general consensus is what I have mentioned above. As soon as rainfall ends, much colder air seeps into our area with temperatures likely falling throughout the day on Monday as deep trough settles in our region at the same time. This strong trough does not go anywhere will likely continue to dominate our area through out the day on Tuesday as well, but high pressure will return in our area so things are shaping up to being much brighter day compared to Monday despite continued cold conditions. With northerly winds under cold air mass, we may have some lake effect flurries which may make its way in our area, but otherwise there will be plenty of clear skies. This airmass will likely be the coldest we have experienced so far this fall season as wind chills will be in 20’s and 30’s. Our expected temperatures will be in the lower 50’s for highs on Saturday and Sunday with temperatures dropping through the 40’s on Monday and upper 30’s by Tuesday. The low temperatures will be in low to mid 30’s Saturday and Sunday night and drop down to low to mid 20’s Monday and Tuesday night. Our overall temperature anomalies will be about 4°F-7°F below normal during the long term period.