Severe Weather Continuing to Look Likely for the Plains on March 22 and 23

Both Sunday and Monday continue to look like possible severe weather and storm chase days in the Plains, and the storm chase team is on stand-by and ready for action.

On both days the major negative factor for severe weather will be the shallow depth and quality of the modified Gulf of Mexico air that will be reside within the warm sector.  We are talking about dewpoints that will mainly be in the 50s and will struggle mightily to reach the lower 60s near the Red River.  This moisture will also be shallow and lead to a good deal of the moisture being mixed out of the lower atmosphere with afternoon sunshine and heating, thus limiting instability.  If there is to be a bust on Sunday, and the potentially bigger day on Monday, then this will likely be the culprit.

Still, there is decent hope for severe thunderstorms, and even a few tornadoes, and that hope resides with good upper level conditions that will overspread the region late Sunday and especially Monday, a sharp and bulging dryline, and more-than-adequate shear for rotating supercell thunderstorms.  These factors alone make Sunday and Monday both days that any respectable storm chaser needs to mark on their calendars as chase days.  This time of year anything you get is a bonus, so why not?

Sunday is an interesting day.  I’m sure there will be a good number of storm chasers that decide to stay home on Sunday due to the upper support being well to the west, and the rather meager and shallow moisture.  Still, the shear wil be good, and EHI values off the 12z NAM are pushing around 1 across northwest Kansas.  A subtle disturbance crossing the dryline Sunday afternoon could be the trigger to get storms going along the dryline.  If instability were to be just a little stronger than forecast, then a landspout or two might be possible.  The cap will also be pretty strong across Northwest Kansas, so any storms that do develop will be discrete with good visibility.  To me, this definitely looks like one of those potential “sleeper events” where later Sunday evening there could be a few chasers kicking themselves for at least not taking a stab at it when they had the chance.  So, it is definitely something to monitor as we head into Saturday and have better data to analyze the possibility.

On Monday, the upper level conditions improve greatly, but as I stated above, moisture concerns will be present, as will pitential cap concerns.  I’d say that anywhere along the dryline from west-central and central KS, southward into western and central OK and northwest and northern TX would be the zone where supercells and a few tornadoes would be possible.  I would love for dewpoints to reach into the 60-65 range across the northwest OK and KS portion of the target, and for moisture depth to be greater, but with wind trajectories coming out of the central and western Gulf that has been modified by wintertime arctic airmasses, I just do not see that happening.  We really need a fetch out of the Caribbean with these dynamic early season systems to really get them cranking into the major outbreak realm, and that’s not going to happen this go around.  Still, given the magnitude of shear and modest instability with a CAPE between 1,000 and 1,400 j/kg, and the good upper level environment, severe thunderstorms will be likely with the mode being supercells with a threat for a few tornadoes.  The EHI bullseye off of today’s 12z NAM from Medicine Lodge, KS into northwest OK sure looks like a sexy target zone to me at this juncture.  However, we are still a couple of days away from this event so this target is sure to change a bit.


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