Surface high pressure will move east today. This means south winds and warmer temps, about 10° to 15° higher than yesterday. Some clouds will be mixed in.
Clouds increase tonight ahead of the next rain system, due tomorrow.
Monday Rainout? Probably.
It is going to rain Monday. The questions are “when” and “how much?” Rather than guess at it, here are the details:
The GFS model thinks the heaviest rain will miss us to the north and south. Notice the parent low (the “L”) running way north of us, with heavier rain staying in Mississippi and Alabama:
The timing on this is morning rain, then a little bit more in the afternoon. This model does not have the spatial or temporal resolution to tell us more than that.
The NAM3 model sends us a line of heavier showers around late morning/lunchtime, then a few more around rush hour and dinnertime.
The WRF-ARW model thinks this is a morning rush hour rain event, with only a few off and on showers running into the afternoon
And then there is the European model, which thinks this is an afternoon/early evening rain event, not a morning event.
No model is “right.” Models are merely forecast tools. This appears to be mostly a daylight rainer, with more rain more likely in the morning, and less rain more likely in the afternoon. NWS-Nashville has us down for just under 0.50″ of rain by sundown, enough to rain out any activity planned on dirt or grass. It’s possible we could get more or less rain than that.
Either way, I think sports are in jeopardy of a rainout Monday night.
Wait. What About Monday Thunderstorms?
It’s going to be windy, and we may see a few thunderstorms inside the heavier rain, but strong or severe thunderstorm potential remains to our south and southeast for Monday.
Watching Wednesday’s Severe Storm Potential
Tuesday looks awesome.
More showers and storms are expected Wednesday afternoon and evening. Watch the “L” move out of Oklahoma and move into Illinois and Indiana.
This should deliver us rain and strong to severe thunderstorm chances Wednesday afternoon and evening.
The Storm Prediction Center has us included on the western edge of a huge generalized risk area from Columbus, OH, to the Gulf of Mexico. Those in this area have a 15% probability of a hail, wind, or tornado within 25 miles of them.
Detailed GFS model data shows an environment with plenty of instability/storm food and shear for damaging winds and some hail, but cloud bases are too high for a large tornado risk. If this model is correct, the threat won’t really get going until it gets east of us, but we could still see some big storm Wednesday afternoon.
The Euro model predicts a stronger system. By Wednesday night, it thinks the parent low pressure center will be located on the Ohio River due north of Nashville, which favors storm development for us. The Euro predicts a large amount of instability/storm food (about 1,500 j/kg CAPE for you weather nerds) with a dewpoint of 64° (!!!!) all the way up into Nashville. If this model is correct, this could really be an event.
Recall the severe weather event that wasn’t last week did not materialize because the warm, moist air was blocked by a system south of us. There is some indication on the Euro model that may happen again. Mostly, though, we are too far away from our other forecast tools to draw meaningful conclusions.
Uncertainties remain high. Our two main forecast tools at this range, the GFS and Euro models, have meaningful differences. Draw only one conclusion: there is a severe weather potential Wednesday, with a time frame ETA Wednesday afternoon/evening.
Cooler Thursday, Friday, & Saturday
Wednesday’s storm system will trigger cooler temps. Highs 60° Thursday and Friday, with lows around 40° Friday and Saturday mornings.
We should be dry for Saturday sports.
Categories: Forecast Blogs