Current Forecast Meet the Forecaster

Issued: 11pm on Tuesday, September 28th 2021

Technical Forecast Discussion

Short Term (Tuesday 9-28-2021 through Thursday 9-30-2021)

Our area is stuck between a trough in northeastern states and a very well pronounced upper level ridge over most of mid-west into most parts of Ohio valley to start out this period. This pattern on surface will translate to high pressure area over Michigan with a surface cold front situated along Ohio river as of this evening. While there is no precipitation associated with this cold front due to lack of moisture, but look for a downturn in humidity levels as due points will fall into 40’s compared to upper 50’s today behind the front. As we head into Wednesday and Thursday, look for upper level ridge to further intensify and inch closer to our area at the same time. The ridge won’t be able to dominate our area as it is fighting with the trough to the east. Given that our area would be located at the eastern side of ridge, north-northwest flow in our area will continue to have low humidity and comfortable temperatures during this forecast period. On surface level, high pressure will continue to dominate our region and allow for clear skies. Our expected temperatures will remain in upper 70’s for highs with lows in upper 40’s which are about 3°F-5°F above normal for this time of the year.

Long Term (Friday 10-1-2021 through Monday 10-4-2021)

As we move into long term period on Friday, we will start to note changes in upper level pattern as the 500H ridge will finally settle into our area, although overall ridge will start to weaken out by this time. On surface level for Friday, we will continue to see high pressure dominating our area with more the same weather wise as it is in short range due to our area still being under residual northwest flow. Weakening trend for 500H ridge will continue as we move into Saturday into early parts of Sunday as our flow becomes more zonal. This pattern will translate to surface in form of a weak warm front lifting north of our area on Saturday and allow our temperatures to warm up by few degrees along with uptick in humidity levels. Later on Saturday, a surface low pressure will develop in response to developing weak trough over high plains and mid-west regions with rain breaking out for those regions. As the weak short-wave slowly moves closer to our area on Sunday into Monday, look for increasing rainfall risk on both of these days. On Sunday, surface low will be over northern Michigan with cold front extending down into parts of Indiana/Illinois with cold front stalling over our area by late Monday. Looking at expected temperatures, highs will be upper 70’s with lows in upper 40’s for Friday into early Saturday. Highs will warm up to lower 80’s during daytime Saturday with lows only dropping to upper 50’s. Rainfall will hold our highs down into low-mid 70’s for Sunday and Monday with lows remaining in upper 50’s.