Forecast Analysis

Right now, mostly cloudy to overcast conditions prevail across Northwest Ohio.  In Northeast Indiana, skies are beginning to clear up, especially west of Fort Wayne.  The surface low pressure system has weakened from 992 millibars this morning, to about 1000 millibars by this afternoon.  Currently, the system is located over western New York and moving eastward slowly, as the upper level air flow becomes locked in place, as another upper level cut-off low comes into play.  This upper level low should not affect our area much except for the fact that it is pulling very cold air into the eastern United States.  As this surface low moves eastward, expect mostly cloudy conditions through 8 or 9 p.m. tonight, with partly cloudy to clear skies after 10 p.m.  With this earlier than anticipated clear up of clouds, expect even lower temperatures than was originally forecast for lows tonight.  I would say that lows will drop to around 36 or 35, especially in areas that are already clearing up right now.  Generally, because of lake-effect rain showers overnight, I would expect the best chance for a frost tonight is areas Fort Wayne and east.  Tomorrow, temperatures will rise pretty slowly throughout the day, with highs only expected to hit the lower to middle 50's, fairly close to today's high temperature.  Even with the chilly temperatures, expect a very nice day tomorrow with partly cloudy to mostly sunny skies.  Overnight, Saturday, due to strong radiational cooling, clear skies, a cold air mass and light winds, expect temperatures to fall to near freezing.  The current MOS computer models are forecast lows from 29 to 34.  Due to wet ground from recent heavy rains, I am going to expect lows right near 33 or 34, but in areas that did not experience as much rain, and in areas east of Defiance, I would expect lows to dip near 30 or 29.  Which ever forecast holds true, I would bring in any plants that could suffer from the cold, because this could be our first hard frost of the year, with even a freeze in a few places.  I do expect the National Weather Service to issue a frost advisory or warning for the area by tomorrow afternoon, as their is a high potential for frost.  Over the weekend, the upper level air flow pattern is expected to shift.  Sunday, their will be a major cut-off low over the East Coast, while around here, a ridge will try and advect eastward from the Central United States.  By Monday, this upper level low will finally begin to break down, allowing the slow eastward progression of the ridge over the plains.  By the middle of next week, the ridge will be right on top of us, causing above normal temperatures and very sunny conditions.  Temperatures could even top 80, especially by the end of next week.  This pattern will not last though, as a major trough begins to dig into the plains, which will cause some storm systems to form and traverse the area.

Official Forecast Through Tuesday, October 4, 2011

Friday Night: Low 35. Colder in regions with less evening cloud cover  Mostly cloudy in the early evening, becoming clear after 9 p.m. Windy at first, becoming calm later in the evening.  Frost possible, especially in the early morning hours.
Saturday: High 54.  Mostly sunny.  Much drier than in recent days.  Very nice day, but chilly at the same time.
Saturday Night: Low 33.  Mostly clear.  Light winds and clear skies, make for a great night for the formation of frost.  Some areas, especially east and north of here, could hit temperatures below 30.
Sunday: High 61.  Mostly sunny.  Light winds from the north.  A very comfortable and nice day.  Chance of rain 0%.
Sunday Night: Low 42. Mostly sunny. Winds light and from the North-Northeast.  Chance of rain 0%.
Monday: High 68.  Partly Cloudy. Winds light and variable.
Tuesday: High 73. Partly cloudy.  Winds light and variable. Very comfortable and one of the warmest days in several weeks.