CheeselandSkies
Member
Plenty of chatter already about this one already in the seasonal thread and SPC has Day 4/5 contours outlined, so event thread time. Discuss the coming Sunday-Monday system here.
-
Welcome to TalkWeather! We see you lurking around TalkWeather! Take the extra step and join us today to view attachments, see less ads and maybe even join the discussion. CLICK TO JOIN TALKWEATHER
Severe Weather 3/15 - 3/16
- Thread starter CheeselandSkies
- Start date
I do think it's interesting how this and several preceding setups have changed so drastically in the sub-200 hour range. Obviously, evolution is expected, but we've dealt with high uncertainty, rapid change or both on several events this season as close as the 48-to-72-hour range. Using SRH to display the change in dynamics due to trough evolution run-to-run on the GFS.
-Note: moved from general thread to this one.
-Note: moved from general thread to this one.
Tanner
Member
I’m at work, so for the sake of time I won’t post any images, but, synoptically speaking, this has the look of a very widespread significant event in the mid south/southeast.
slenker
Member
Yeah, this trough reminds me of bigger events, 100%. Jet translation speed looks quite good too - haven't crunched any numbers but I would reckon it's definitely north of the 40 kt threshold.
Ozonelayer
Member
Taken in Northern MS
12z NAM is in, and I'd like to point out that literally the only problem I can find with my limited knowledge of soundings is the dew points and, by extension, CAPE.
warneagle
Member
Thermos really shouldn't be an issue either. the GFS is already showing 1000-1500 J/kg CAPE over the ArkLaMiss on Sunday afternoon/evening even with the likely-underestimated moisture return and dews hovering in the low 60s. lapse rates look really good for the south in March.
warneagle
Member
the NAM has a known bias for underestimating temperature and dew points, especially in the cool season, so you shouldn't take whatever it's showing in terms of thermodynamics verbatim.
- Thread starter
- #8
CheeselandSkies
Member
70/61 is plenty in March. Although it being the NAM, temperatures will likely be a few degrees higher, but spreads still shouldn't be prohibitive for tornadoes.
Your main concern with limited moisture is temperature-dewpoint spread/LCL, when they exceed 15 degrees or so and especially approaching 20. Also if the moisture is too shallow it can mix out easily, leading to those higher spreads by the time storms fire.
GFS has depicted at least a small tongue of 500+ j/kg instability making it well into Georgia in the middle of the night, which is unusual as far as the depiction of instability on globals goes, so I don't think it'll be an issue either.
slenker
Member
I ran a very rough analysis on the jet translation speed from 00z to 18z on the 15th with the 06z GFS. I determined the location of the jet core at 00z to be in the far northeast quadrant of Oregon and the location of the jet core to be in northwest Texas below the panhandle at 18z:
The distance is just over 1100 miles according to this website. It's worth noting that the trough also doesn't take a straight line path to this location due to it digging in, meaning it may technically be an even further distance than what is shown here:
Nevertheless, I crunched the numbers - and staying conservative with the distance I calculated it with 1050 miles instead of 1100. Doing so yields a jet translation speed over 18 hours of about 58 miles per hour, or ~50 knots. This is a very similar number to 3/14-3/15 last year, and just so happens that the distance is the exact number Trey used to calculate the jet translation speed for said day as well, when he got a distance between the two of over 1100 miles too. I'm not saying it will be the same event but this is undoubtedly similar in some ways.
EDIT: It's worth noting that the jet core at 00z could definitely be shifted a bit further to the southeast from where I located it, but doing so would still definitely yield a jet translation speed north of the 40 kt threshold, just slightly less than 50 kts.
The distance is just over 1100 miles according to this website. It's worth noting that the trough also doesn't take a straight line path to this location due to it digging in, meaning it may technically be an even further distance than what is shown here:
Nevertheless, I crunched the numbers - and staying conservative with the distance I calculated it with 1050 miles instead of 1100. Doing so yields a jet translation speed over 18 hours of about 58 miles per hour, or ~50 knots. This is a very similar number to 3/14-3/15 last year, and just so happens that the distance is the exact number Trey used to calculate the jet translation speed for said day as well, when he got a distance between the two of over 1100 miles too. I'm not saying it will be the same event but this is undoubtedly similar in some ways.
EDIT: It's worth noting that the jet core at 00z could definitely be shifted a bit further to the southeast from where I located it, but doing so would still definitely yield a jet translation speed north of the 40 kt threshold, just slightly less than 50 kts.
Last edited:
Just the drastic temperature differences in itself spells outbreak. Yesterday system and previous systems this month haven't had that (or much of it). The well, this looks like a low CAPE/high shear setup, just a squall line, can't rule out possible isolated tornado, etc. are basically what you hear every single time until the day of. It's funny in a way.
Kds86z
Member
This has taken me by surprise as forecast’s by several notables said long quiet period after this week.
Kds86z
Member
bckhd2
Member
A little surprised at how quickly this has uptrended. Not able to access models at work but have seen the SPC outlooks. Want to clarify - it looks like Georgia will miss the majority of the threat here. Am I reading that correctly?
bckhd2
Member
I was interested to see that as well. I wonder if it'll be the temperature differential driving that? Some places are supposed to drop ~40 degrees between Sunday and Monday, so the cold front has to be pretty aggressive. I guess similar to the Indiana event, any cell that gets out ahead and locks in the warm sector could get up to something?
Kds86z
Member
Hopefully the last front of this month, I can’t take anymore wild barometric pressure rides lol.
WeathermanLeprechaun
Member
It makes sense. Potential QLCS event with more than adequate instability.
This trough can cause problems and i fear that models underestimating moisture is hiding us from the more alarming picture at play. There is intense dynamics well in place with this system.
WeathermanLeprechaun
Member
I could ask Broyles what he thinks of this event, given the jet translation speed and is it going to hold much concern for the SPC in the following days. Wonderful analysis
Kds86z
Member
Ask him where he’s been lol.. no outlooks by him. Jk though