Southern Mississippi: Next round of potential severe weather arrives March 3rd/4th

Enjoy the sunshine and dry weather this weekend. The next round of storms arrives on March 3rd / 4th. the Storm Prediction Center has highlighted the area with a Slight Risk for severe weather.

Screenshot from 2020-02-27 15-17-00
Courtesy: spc.noaa.gov

From the SPC:

The potential for substantial low-level moisture return across parts of east TX into the ArkLaMiss by Day 6/Tuesday has increased. Low and mid-level flow are also forecast to markedly strengthen across these areas, particularly Tuesday evening into early Wednesday morning. With strong forcing for ascent preceding the upper trough/low, a surface low should deepen as it develops northeastward from portions of east TX into the vicinity of the Mid-South. A trailing cold front should also shift eastward across TX into parts of the lower MS Valley by the end of the Day 6/Tuesday period (early Wednesday morning).

A thermodynamic and kinematic parameter space favorable for the formation and maintenance of organized severe thunderstorms will probably exist over these areas from Tuesday evening though early Wednesday morning. Storms could form both along and ahead of the eastward-moving cold front, with all severe hazards possible. Therefore, a 15% severe delineation has been introduced for Day 6/Tuesday. There is some uncertainty with how far east the threat will extend into MS late Tuesday night, and adjustments to this 15% area are likely.

Uncertainty in the placement of both the upper trough/low and related surface low increases into Day 7/Wednesday. At least some severe threat may continue across parts of the Southeast (mainly AL/GA vicinity), but low-level moisture should gradually decrease with eastward extent. 15% severe probabilities may be needed in a later outlook issuance over parts of the Southeast on Day 7/Wednesday once the synoptic-scale evolution becomes a bit clearer.

We got that data

Here is a quick look at some of the model guidance from the CIPS and the CFS Chiclets (I don’t often show these).

Screenshot from 2020-02-27 15-28-08
Courtesy: Saint Louis University

The CIPS Analogs picked up on this threat late last week. And it continues to show the signal that next Tuesday and Wednesday could feature some more-significant weather. Notice, though, that the CIPS shows only a Slight Risk (15-percent) for severe weather. And while I’m not including it graphically, it lowered the threat for a tornado to below 2-percent.

The CFS Chiclets can be a useful tool when looking to confirm or dismiss the threat for severe weather. It isn’t as good at identifying specifics as it is identifying the overall general environmental setup.

Screenshot from 2020-02-27 15-28-27
Courtesy: spc.noaa.gov

It works by counting every little blue box – along the top row – from left to right. The black line above the blue boxes indicates how favorable the environment is, at any point in the US, for severe weather.

When those blue boxes turn a different color or have an X in them, it indicates better chance for severe storms.

Looking down the line of blue boxes, the first X is on Day 6.

Screenshot from 2020-02-27 15-28-44
Courtesy: spc.noaa.gov

And this area lines up with where the SPC was suggesting there was the potential for severe weather on Day 6, and that lines up with where the CIPS was indicating there was the potential for severe weather on the same day.

For what it is worth, the Karrie Meter has been running between a 3.74 and a 3.93 since late last week.

That converts back to a Marginal-to-Slight Risk for severe weather for South Mississippi.

What we know!

There will be the potential for storms and severe weather from Tuesday night through Wednesday across the region. The threats look to be heavy rain, frequent lightning, wind gusts exceeding 60mph and hail. There is also the potential for a few tornadoes.

What we don’t know…

We don’t know any specifics like, where it will be worst, when storms will begin, or anything that you may want to know for planning or attending a specific event.

When we will know more

Every 12 hours another batch of useful data comes out. So, overnight tonight and into tomorrow morning (1), and then again tomorrow afternoon (2) will be the next two times when good data will be available. Then on the same timetable for Sunday.

By Monday, we get to a point where useful data arrives every six hours.

By Tuesday night good data will be coming in every hour.



Author of the article:


Nick Lilja

Nick is former television meteorologist with stints in Amarillo and Hattiesburg. During his time in Hattiesburg, he was also an adjunct professor at the University of Southern Mississippi. He is a graduate of both Oregon State and Syracuse University that now calls Houston home. Now that he is retired from TV, he maintains this blog in his spare time.