Issued: 11pm on Saturday, September 11th 2021
Technical Forecast Discussion
Short Term (Friday 9-10-2021 through Sunday 9-12-2021)
The period is starting out with departing trough northeastern part of United States with strong 500mb ridge over four-corner regions ready to extend eastward. Given the upper level flow is still out of northwest direction, weather conditions on Friday were cooler with dry conditions due to surface high right over our region. As the surface high and 500H ridge extend eastward, the return southerly flow will allow warmer temperatures to settle in for Saturday with slight uptick in humidity. By Sunday, 594dm intensity 500H ridge is expected to pop right over our area with continued increase in temperatures and humidity levels in the area. Given that we lack upward forcing and presence of surface high near by, dry weather is expected to prevail through entire short term period. Given our upper pattern and translating to weather on surface level, we will see highs warming up from mid 70’s Friday – lower 80’s Saturday – upper 80’s on Sunday with low temperatures rising from lower 50’s to low-mid 60’s for Sunday and Monday morning due to increase in humidity.
Long Term (Monday 9-13-2021 through Thursday 9-16-2021)
As we head into long term range, few complex changes are expected to happen, but we first continue to have a 500H ridge centered over Ohio Valley which will start to weaken through the course of Monday into first half of Tuesday. While our upper level flow in our area becomes rather zonal from late Tuesday into early Wednesday, another area of strong ridge starts to develop over Bermuda area which then extends as far west as entire Mid-West to Ohio Valley region from late Wednesday through Thursday. While this is expected to happen, a trough which develops over Manitoba on Tuesday moves eastward into Ontario and Québec on Wednesday, and this through will draw a surface cold front which moves down into northern Ohio Valley region. Given that warm conditions and higher humidity is expected to be present, we may see formation of showers and thunderstorms before they depart by Thursday and cool things down a little for couple of days. Expected temperatures during this period will drop from upper 80’s to 90 on Monday-Tuesday to lower 80’s for Wednesday-Thursday for highs with lows dropping from mid 60’s to lower 60’s respectively with overall dry conditions in store for us next week, with only exception of Wednesday.
