What a nice week to end October and move into November. Skies have been generally sunny all week despite temperatures that have been slightly below average. Temperatures should be in the mid-60s for this time of year in Bowling Green but highs have been in the 50s to near 60 this week. As for overnight lows, Bowling Green fell to 30 degrees Thursday morning which is one of the coldest nights we’ve had thus far this fall. There has been a gradual warm up in temperatures this week and this slow warm up should continue into this Saturday before yet another trough dips down to encompass southern Kentucky by Sunday. As the trough and the jet stream dips to our south, slightly cooler air will once again filter into our area. Until then however we will be on the southern edge of a trough but very near the southern edge of the jet stream as a ridge tries to build in. Generally when this jet moves to our north we warm, and when it moves to our south we cool down, thus this week with the jet stream virtually speeding by directly above us temperatures have been fairly consistent and neither warm nor cold.
NAM 300 mb heights/winds forecast for Saturday afternoon. Temperatures will gradually warm thanks to being on the south side of jet stream but overall temperatures will be relatively neither warm or cold.
Thus until the trough dips in on Sunday expect temperatures to be warming ever so slightly. A shortwave is expected to move through Saturday afternoon ahead of the trough which could bring enough lift to create a few showers. Rain chances Saturday afternoon are about 40% though any rain that does fall should be very light with a 0.1 of an inch of rain at the very most. The system lacks a strong forcing mechanism as warm thermal advections and positive vorticiy advections will be very weak if present at all.
NAM forecast vertical velocity (rising air) at 7 pm Saturday. Increased vertical velocity here in southern Kentucky at this time just ahead of the shortwave (yellow dashed lines) indicates rising air and thus a chance of rainfall.
In summary, expect a very slow warm up through Saturday followed by increased cloudiness as rain chances enter the picture Saturday afternoon. Cooler air will once again try to spill its way in by Sunday. Looking longer term into early next week, models somewhat disagree to the strength of another trough axis moving through, nevertheless, more troughing is expected and thus cool weather will likely continue.
Daily Forecast:
Friday: Low: 40 High: 63 Mostly sunny skies with increasing high clouds late in the day. Northwest winds will become more northerly; speeds from 4-9 mph.
Saturday: Low: 35 High: 64 Mostly cloudy skies will become overcast with a 40% chance of rain after noon. Rain will be light with up to a 0.1 of an inch possible. Winds from the north-northeast turning to the north at 5-10 mph.
Sunday (Daylight Savings Time Ends: Fall Back): Low: 41 High: 57 Partly to mostly sunny with light north winds between 3-8 mph.