Severe WX Severe Threat 17-18 March 2021

[Mike S]

Watch likely coming soon to northern Mississippi and surrounding areas, including Memphis.

 

[JBishopwx]

Tornado Watch upcoming for North Ms

 

[Mike S]

There it is...

 

[MattPetrulli]

Welp, there was the CAM (especially HRRR) uptrend I was waiting for to get to high-risk level confidence.

Yeah HRRR has really trended towards an outbreak, was waiting for that to happen for high risk level confidence here too. HREF was also showing a fair amount of discrete cells last night with its 00z run too.

 

[Kory]

Winds are switching from the E to the SE in Tuscaloosa.

 

[David in SW Blount]

I think the wedgie made it pretty far west. It's 57° at the PWS closest to my house, and I had to close the windows! Will be interesting to see that get obliterated in short order.

 

[Kory]

Very MCV looking feature developing over NW MS. It seems to be moving with a lot of easterly component.

 

[Casuarina Head]

Regarding the D2 MDT Risk: the GFS has trended toward more of a positively tilted trough with messier wind profiles tomorrow afternoon. That could modulate the extent and coverage of the hatched 15% TOR area over the Carolinas. The positive tilt starts emerging on the GFS as early as 12Z tomorrow. This is something to watch down the line. Regardless, the ceiling for today has definitely trended upward and could end up meeting or exceeding expectations, whereas D2 could underperform somewhat, but it’s still a bit early. Nevertheless, wind profiles on D2 are as strong as before, albeit messier.

 

[The Nino]

Hrrr still holding onto the cape not making it to the hsv area.

 

[LP98]

Hrrr still holding onto the cape not making it to the hsv area.

Any thoughts on timing for HSV during the day?

 

[Richardjacks]

Any thoughts on timing for HSV during the day? all depends on when the warm front crosses, I am sure it will, probably late this afternoon or early this evening.

 

[OHWX97]

09Z HRRR for anyone who was questioning today's event based on lack of intense UH tracks.

 

[Marshal79344]

Woah look at this embedded circulation near Jonestown, MS

 

[Richardjacks]

Very MCV looking feature developing over NW MS. It seems to be moving with a lot of easterly component.

I see that, boy that will leave a boundary in north Mississippi, got to keep an eye on that thing for later impacts on storm development...

 

[MattW]

It's looking more and more like Georgia won't see a whole lot from the main event or before, but could see some strong storms around sunrise tomorrow morning with the threat in east Georgia gradually increasing through the morning.

 

[OHWX97]

Likely some intense straight line winds with that northern MS bowing segment. Velocity surging ahead very rapidly.

 

[Casuarina Head]

Based on mesoscale analysis and METARs, the CAD so far seems to be verifying more strongly than the earlier HRRR runs indicated. Surface dew points of at least 60 °F are barely N of LIT and MEM, whereas the HRRR runs showed the isotherm farther north by now. However, current convective evolution over N MS and NW AL seems to be largely on track, in line with HRRR forecasts. Additionally, METARs indicate that the dew points to the south of the CAD are verifying at least a bit higher than forecast, especially close to the Gulf Coast. So the low-level air mass is clearly very humid.

 

[Richardjacks]

Based on mesoscale analysis and METARs, the CAD so far seems to be verifying more strongly than the earlier HRRR runs indicated. Surface dew points of at least 60 °F are barely N of LIT and MEM, whereas the HRRR runs showed the isotherm farther north by now. However, current convective evolution over N MS and NW AL seems to be largely on track, in line with HRRR forecasts. Additionally, METARs indicate that the dew points to the south of the CAD are verifying at least a bit higher than forecast, especially close to the Gulf Coast. So the low-level air mass is clearly very humid.

Models are having a difficult time resolving the high gradient warm front. Tds change dramatically over a small space, plus there will be some scouring...some areas it will be wrong, right in others

 

[Kory]

HRRR showing large UH streaks this afternoon across AL with the pre-boundary stuff.

 

[Fred Gossage]

HRRR showing large UH streaks this afternoon across AL with the pre-boundary stuff.

And with this environment...