Dry, again

Midday Wednesday

We caught a nice break yesterday afternoon as the cold front finally decided to generate some showers/thundershowers around the area. (I had pretty much given up on the system - my lawn and garden are glad I was wrong on that call!) The heaviest rain hit southern Indiana and moved southeast over the eastern half of Jefferson County and into Oldham and Shelby Counties.  Radar estimates showed much the area named above had .5" or higher with the peak of 1"+ over a few spots of Oldham County.  Most areas south and west of Louisville fell far short of that with most areas less than .25".

No hope for any rain the next two days.  A pleasant air mass has followed the cold front of yesterday.  The air over us now is VERY dry for summer, so most of yesterday's water will evaporate quickly.  But the weather will be nice - sunny, warm days and a cool night in between.

Models have developed a big difference in forecasts for Friday and the weekend.  Yesterday they were in pretty good agreement, but not now.  With a northwesterly flow aloft expected to remain at least the next 4-5 days, small energy impluses flowing out of Canada will be likely.  These systems often kick off big complexes of thunderstorms over the Plains and then drift them southeast, sometimes reaching the Ohio Valley before fading. These storm outbreaks, routinely called MCC's (mesoscale convective complexes) or MCS's (mesoscale convective systems), go a long way to keep our nation's "bread basket" productive each growing season.

Now, the model argument - the NAM/WRF kicks off an MCC Thursday night into Friday that, if it can hold together, offers the chance for showers/Thunderstorms Friday P.M., especially over Indiana.  Then, the WRF generates a stronger piece of energy and slides it very slowly into IN Saturday/Saturday night.  That would have the potential to be a pretty good rain-maker over the lower Ohio Valley.  But, wait a minute...the GFS also likes the idea of an MCC late Thu/early Fri, but is a litel weaker with it.  Thus, it gives the system less chance to reach us.  Yesterday, the GFS also liked the idea of the Saturday system.  In fact it was more aggressive than the WRF.  But, for the past two runs, the GFS has virtually lost the whole system putting us in a dry, steamy weekend pattern.

So, over the next 48 hours will the WRF move toward the GFS solution?  Or, will the GFS rediscover the WRF's idea?  Or, will they drift toward some weaker middle ground?  If we want to see any further easing of the drought conditions, we'd better hope the WRF's on the right track!  Otherwise, things are going to get a lot worse.

Comments

[John]

But if some of the models ARE right and we get those MCS's wouldn't that also mean we would get some severe weather?

We need rain, But i would sacrifice my lawn if it means getting dangerous weather to save it.