Overnight – Monday: Rain Arrives
More rain is coming.
Overnight, the northwest side of an upper-level-low-pressure-made rainer should arrive. Here’s the HRRR’s take:
Whereas this morning we felt like the rain would almost certainly blast us and wash out the entire day, the afternoon model runs have suggested the bulk of the rain may run east of I-65 and give us a shot at playing ball tomorrow night.
Even the European model, which was drenching us with about an inch of rain during the morning model run, is also following this shift east.
If it keeps going that way, we may play tomorrow night. As it stands, I still think we’ll see a good bit of rain.
NWS-Nashville still has us down for 0.34″ of rain through 6 PM Monday night. But, stay tuned.
Cloud cover will keep temperatures pretty chilly. We will wake up in the mid 40°s. Expect a high of 55°.
Wednesday Night: Strong/Severe Storms
No new information to report on this until tomorrow morning. So, if you read this earlier today, you can stop here : )
We clear out Tuesday, then all eyes turn to the west for Wednesday. SPC has already outlooked this area for severe thunderstorms, and we’re on the east side of it:
Weather models are in general agreement that a fast-moving line of showers and thunderstorms will arrive Wednesday night.
This line will be driven by a negatively tilted trough (that’s the bad/strong kind) . . .
. . . bombing out a surface low moving into the Great Lakes and trailing a strong cold front through the middle of the country.
The result: shear will be, to use NWS-Nashville’s words, “off the charts.” For weather nerds, deep layer shear between 60 and 75 kn, with 0-3 km helicity values between 500 and 600 m2/s2.
This can cause storms to rotate. The good news is that there won’t be much available “stuff” to rotate. The kindling for this fire will be sparse and short-lived.
This meager CAPE is the reason our tornado spidey senses are not tingling, at least not right now.
Therefore, the main concern is a straight line wind threat as the squall line arrives sometime late Wednesday night or early Thursday morning.
Now, all that said, if we see just a wee bit more CAPE (“stuff”) arrive ahead of the line, things could be worse. We have had really bad storms – including tornadoes – born from low CAPE.
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Categories: Forecast Blogs