25 Oct KSDF forecast

posted Oct 25, 2012, 2:54 PM by Michael Baldwin   [ updated Oct 25, 2012, 2:54 PM ]
fun forecast, I always love these "midnight max/midnight min" days.  strong cold front currently in central IL is expected to pass through KSDF tomorrow morning, close to 12Z.  precip should begin shortly after the front passes and continue for ~8h or so.  expecting their max temp to occur at 06Z tonight, so the question is: what's the temperature going to be at 06Z tonight?  MOS and meteogram guidance going for low/mid 60s, it was 61 there last night at 6Z, stronger winds ahead of the front tonight will likely slow radiative cooling, so the 63-65 range indicated by MOS guidance sounds good to me.  sometimes you'll see temps go up a few degrees after the cold front passes in a night-time FROPA due to strong mixing behind the front and a cooling inversion ahead of the front. however, since this fropa not expected until close to sunrise, the "midnight max" appears to be most likely.  with the strong cold advection during the day/evening, min temp should occur tomorrow night at 06Z, again MOS and meteogram guidance is pointing at mid 40s for a min, somewhere between 43-47 seems reasonable.  models are pretty consistent with QPF, very close to 0.40" for all of the guidance. Purdue WRF is showing a bit more, something like 0.60".  Winds will be a bit tricky, plenty of mixing and gusts behind the front, meteograms and forecast soundings show ~20-22kts just above the surface during the afternoon, that momentum should be able to make it to the surface.  lots of spread expected with all of the numbers today, not sure if everyone will pick up on the midnight max/min issue and will go with MOS values which are 12h min and 12h max values, those will be terrible forecasts.  So expecting consensus to be something like 60/48/20kts/0.4", should be an opportunity to separate yourself from the pack with a good forecast today!