loadedgunchasing.com Blog

Change of plans. I had some other stuff come up and I haven’t had enough time to do my forecasting so I’ll have to do it in the morning. I promise I’ll get one posted early tomorrow though

I haven’t had a chance to do all my forecasting yet. I wanted to wait to post a forecast until after I’ve had a chance to look into the possibility for storms for tomorrow, next Monday and Tuesday too. Sooo, I’ll get that done later this afternoon and try to get a forecast posted tonight that will cover tomorrow, Friday and next Monday and Tuesday.

The 12Z runs this morning are a god damn mess. There are major differences between the NAM and GFS on both the upper air pattern and the surface pattern. Both models want to veer 850mb winds, which is probably more damning to tornado potential than anything else. The moisture looks fine with both models, but the NAM doesn’t show much of anything in the way of CAPE as a result of no surface heating over the warm sector.
Basically the GFS shows a little more open wave, which veers the mid level winds a little more. That’s definitely a good thing. The GFS also allows better insolation when compared to the NAM which results in a more unstable and wider CAPE field.
The NAM is farther west with the mid level trough and as a result the surface boundaries are quite a bit farther west as well. The moisture isn’t quite as good as it is with the GFS, but it’s still fine. The NAM keeps more meridional flow at 500mb over the warm sector, which kind of sucks. Like I mentioned before the lack of surface heating with the 12Z run of the NAM leads to very little CAPE in a narrow window. That would certainly be a major problem if it verified, but you can pay any attention to those small of details this far out, especially when there is disagreement among the models.
Both models are displacing the low level jet to the east of the moisture axis and veering the winds right ahead of the boundary at 850mb. That would definitely be a big problem for the tornado potential.
All this mornings runs have done is add confusion to the forecast. I am still optimistic that this will be a severe weather event and I still believe we will get good moisture in place for Friday, but there are major uncertainties regarding the shear profile, insolation (and resultant instability) and the exact location of surface boundaries. At this time I don’t expect this to be a big tornado day. It’s impossible to predict any sort of tornado threat if any at this time though since any one of the uncertainties I mentioned above can ruin the tornado potential. All we can do now is hurry up and wait.
I will try to post again tonight after I look over the models a little more. I may just wait for the next run before posting again.

I am going to post a forecast later after I get home. After glancing over the 12Z GFS I have a few comments to make. I still think the two major problems with this setup is the lack of directional shear due to backing mid level flow and too much forcing (too much convection/storms won’t be discrete and storms firing too early may also be a problem).
Some smaller issues that concern me are morning convection and 850mb flow. The GFS has been very consistent in producing convection in the am. I’m not exactly sure what’s initiating the convection, but I’ll look into it later when I do my forecasting. Cloud cover and crapvection is always a concern though when you have morning convection like that. On the 850mb winds the models have been wanting to keep the stronger 850mb flow out over the warm sector quite a ways. If storms fire along the dryline they will have a pretty long treck to get into the strongest low level winds if the gfs ends up verifying. This has been a consistent trend so I’m becoming a little more concerned about it. I’m also not a fan of 850mb winds veering earlier in the day before backing. It seems like every time you are waiting on 850 winds to back it doesn’t end up happening soon enough.
All that being said I do still think that this is a synoptically evident severe weather event. The CAPE and deep layer shear combination will be more than adequate for severe storms. I wouldn’t be at all surprised to see the highest instability we’ve had so far this year in the plains if we get good insolation. Unlike a lot of people I’m not that worried about moisture return. The models have been very consistent in starting moisture advection on Wednesday. You don’t get a very good fetch off the southern gulf until Thursday, but from then on the trajectories and wind speeds are pretty damn good, especially in the lowest portion of the BL. I will take three days of moisture advection ahead of a trough every time. Until I can start looking at forecast soundings and actual soundings I’m not going to worry about moisture depth or the potential for mixing down. I don’t think that will be much of a problem, but until we can get forecast and actual soundings there’s not a whole lot of reason to waster your time on this.
Like I mentioned before I do think this is a synoptically evident severe weather event, but the potential for cloud cover/crapvection over the warm sector and too much forcing/nondiscrete convection could very well mitigate the severe weather potential.
The tornado potential is obviously much harder to guess at this far out. The backing mid level winds and lack of directional shear can be an absolute killer for tornado potential. Typically when we have stacked or closing lows like this I will either cheat south far enough down the dryline to where mid level winds veer a bit more and storms tend to be more discreet. That or I play the warm front and hope that the backing surface winds will be enough to get it done. One way or another I will definitely try to offset the poor directional shear. With this setup the gfs has been keeping a nontypical surface pattern with a cold front rushing south. That doesn’t scream tornadoes to me over the northern portion of the risk area.
Anyway, it is a complicated forecast and we still have a long ways to go so a lot can change. I will try to get a forecast posted tonight. If I don’t I’ll get one up tomorrow morning.

Well I’m not going to post a forecast this morning. I don’t like the 12Z run of the GFS. There are several changes with this mornings run and I think some of them are wrong. The triple point is much farther south over Texas. The precipitation pattern is a little weird too. And the latest run has dislocated the better low level winds from the dryline and kept them out over the warm sector. The last two things I mentioned especially don’t make much sense to me so I’m going to disregard this run and wait to see when the 00Z shows.
The overall picture is still the same. A high amplitude slow moving trough will affect the southern plains on Friday. Due to the slow movement of the trough and a high pressure system over the southeast US, very good moisture advection will take place ahead of this shortwave and I wouldn’t be surprised at all if we get the best instability that we’ve seen all season on Friday.
I will post a forecast after the 00Z tonight or tomorrow morning after the 12Z.

I am going to post a forecast tomorrow morning after the 12Z runs come out. I have read a lot of people’s posts on stormtrack complaining about moisture being a problem with this setup next Friday. I personally think that’s a tad bit ridiculous. I don’t want to get into all kinds of details now, but the gfs has been very consistent in showing three days of moisture advection ahead of this next trough. That is very good for any trough. Usually you only get 24-48 hours of advection. The last 48 hours have very good trajectories and wind speeds are quite strong too. Moisture will not be a problem and as long as we get decent insolation instability won’t be a problem either. In fact I’d bet we the best instability we’ve had so far this year over northern Texas and Oklahoma.
The big problem that we are going to have with this setup is the poor directional shear. I am failry confident that next Friday will be a decent severe weather event, but the tornado potential remains very much uncertain. The directional shear very well may determine the extent of the tornado threat. Any time you have sufficient CAPE and good deep layer shear you can get a tornado, but in order to have a respectable tornado outbreak you have to have some degree of directional shear. It can make or break a setup. With these closing/stacking lows directional shear is always a problem and I’m sure it will be with this one too. It just depends on to what degree it is a problem with this one. If we can get really good backing in the low levels that can help to offset the backing of the mid level winds. Also if you can get mid and upper level winds veering a little bit more farther down the dryline that can help too. Or if we can get good enough instability all the way up to the triple point and we get a classic warm front setup (gfs not showing that now) then that could prove to be an area where the directional is locally increased and the tornado threat is maximized.
There are lots of possibilities, but I am failry certain that the kinematics will be more than adequate to get respectable moisture ahead of the dryline by Friday. Deep layer shear won’t be a problem, so if we can get adequate insolation I don’t see anything preventing a severe weather event next Friday.
I will post a forecast tomorrow morning some time.

I am starting to gain a little more confidence in the idea that next Friday may be our first decent chase day of the season.

There have been a few changes in the upper air pattern, but for the most part everything is the same. A slow moving neutrally tilted trough will move on shore Wednesday. The trough will dig south and take on a negative tilt before it moves into the plains on Friday. The current run of the GFS has the trough closing off over the Rockies and then opening back up again, but you can’t get wrapped up in those kind of details this far out. Even if it did become and open wave again, the trend has been for marginal directional shear at best ahead of the dryline so I don’t think it will make much difference.

A lee side low will form over Colorado with the approach of the upper level trough. At the same time a large surface high pressure system will be over the southeastern portion of the United States. The combination of the two will create favorable trajectories off the gulf into the southern plains for good moisture advection ahead of the trough. In addition to that, the long break between the trough that will move through the plains tomorrow and the trough at the end of next week, will allow an extended period of moisture advection when compared to a typical wave train pattern. It is too early to guess at what kind of airmass will be over the gulf, but with that long of a duration of moisture advection we should be able to get at least marginal moisture pretty far north. Moisture is always a problem this time of year and I think it probably will leave something to be desired with this setup too, but you can’t really ask for a better setup for moisture advection than we’ll have (if the GFS is to be believed). The moisture getting advected may not be that great, the the trajectories and wind speeds will be quite good.

I got to be careful not to nitpick details this far out, but on the larger scale there are a couple things that bother me a bit with this setup. One is that I’m not a big fan of the poor directional shear you usually get with troughs that are stacking up like this one has been doing for several runs now. When you have virtually no turning from 850mb to 500mb that doesn’t instil a lot of confidence in me on the tornado potential. The other thing I don’t like is that with mature negatively tilted troughs that are closing off or close to it like this one tend to have too much forcing with them and you get storms firing too early in the day and they aren’t discrete a lot of times too. Again not a good thing if you’re looking for tornadoes. There is no way of knowing if these things will be problems or not with this setup, but right now those are my concerns.
I will probably post a new forecast tomorrow.

I am going to wait until the 12Z run tomorrow morning to update my forecast. I will have it posted before noon tomorrow.

I didn’t bother looking at today’s setup for this forecast since it appears as if it is going to be uneventful.
The trough that is currently entering the plains is going to make a quick exit from the area as it moves east of the plains by tomorrow morning. Another short wave will follow in it’s wake and affect the plains on Friday and Saturday. Due to the low amplitude nature of the trough and short recovery time for moisture advection behind the current trough, quality moisture will not make it far enough north for any sort of a tornado threat over the plains on Friday. By Saturday dewpoints in the 55-60 range could possibly make it as far north as southeast Oklahoma. Instability won’t be very strong, but CAPE and deep layer shear will be good enough for a few severe storm across eastern Texas and southeast Oklahoma. I doubt there is any tornado threat on Saturday due to limited instability and veering low level winds.

I am a little more hopeful for next week. Some time around Tuesday of next week a large neutrally tilted trough should move slowly on shore. With a good break between troughs and the high amplitude of the approaching trough, there should be better conditions for moisture advection ahead of this next system. It is still too early to get into details and I only looked at the GFS on RAP, which only goes out 7 days, but there is a very strong jet streak that is forecast to enter the back side of the trough as it moves on shore which should help to deepen it and take on a negative tilt as it enters the plains. Like I said it is way too early to tell, but I wouldn’t be surprised if this is our first decent tornado setup this year.
I will try and get a new forecast posted tomorrow.

The last two runs of the GFS and the latest run of the European have amplified both short waves that come through next week. The first one comes through the plains on Wednesday and the second more potent trough ejects into the plains on Saturday. Odds are moisture advection will be a problem with both of these setups. Currently the GFS is showing low 50 dewpoints on Wednesday and mid 50′s on Saturday. There isn’t a whole lot to say about this setup right now since it is still a ways out and because the models have been jumping around on it. Hopefully the next couple runs will settle down. Regardless, this is likely going to be the typical early spring setup where instability is at a minimum. I really don’t like trying to decide whether or not to chase on these kinds of setups. They always seem to be more unpredictable for some reason.
I’ll update the forecast as soon as the models get a little more consistent.

It doesn’t look like there is a whole lot to look forward to in the near future. After the current trough over the plains exits east the jet stream will settle down a bit over the plains. A couple weak disturbances will move through the upper level flow, the first of which will come through mid week, but any weather generated by these will be insignificant. The only silver lining I can see with the weather pattern over the next week is that the deamplified nature of the jet stream should allow decent moisture to stay over the gulf as opposed to getting wiped out on the backside of a deep trough. Hopefully this will make it a little easier for the next major trough to advect quality moisture into the plains.

Well Friday doesn’t look good. A cold front will run NE to SW from central Kansas down to the southern Texas panhandle will it will intersect with a surface low Friday afternoon. There is little in the way of CAPE, but the best instability will be near the triple point. Poor moisture, weak instability and insufficient low level shear will keep any tornado threat to an absolute minimum. I would be really surprised to see a tornado on Friday.

On Saturday the tornado potential will increase. Better moisture will have made it’s way inland by this point, with upper 50 dewpoints across most of the warm sector. With temperatures in the mid 60′s LCL heights will be fairly low. Unfortunately the low temperatures will also minimize instability, but 500-750J/kg of SBCAPE ahead of the cold front in eastern Texas and western Louisiana seems reasonable. There are some serious limiting factors with this setup though. Low level winds will be veering, but this will be offset to some degree by westerly winds at 500mb and 700mb, which will create sufficient directional shear for a tornado threat. Still low level shear doesn’t look very impressive at this point. I’m not real fond of rapidly moving cold fronts serving as a focus for tornadic storms either. It doesn’t work out well a lot of times. That being said, I do think there is a decent chance of a few tornadoes over east central Texas and northwest Louisiana on Saturday, but I’m not nearly as excited about it as SPC seems to be in the latest outlook.
I haven’t looked at Saturday’s setup real closely yet so I will try to tonight and I’ll update my forecast after I do. From what I’ve looked at I do think the best area for tornadoes will be over east central Texas and the northwest portion of Louisiana where you get the best compromise of CAPE and low level shear.

The GFS is showing a pretty sloppy upper air pattern over the next seven days. The only potential chase opportunity will be this coming Friday when a positively tilted trough approaches the central/southern plains.

A closed low is going to move through the far southern plain part of Texas on Monday and then push off to the east coast by midweek.
On Thursday a strong jet streak will move out of the Pacific Northwest and into the back side of a small trough along the Canadian border. This will increase the amplitude and dig the trough farther south Thursday into Friday. At the same time a jet streak in the sub-tropical jet will move east through zonal flow and enter the plains at the same time as the trough in the polar front jet.
Northerly low level winds through midweek will shun moisture southward and prevent any quality moisture from being advected back into the plains when the low level flow does switch to southerly with the approach of the upper level trough. The GFS is currently showing dewpoints in the lower 50′s across the warm sector on Friday. I haven’t spent any time on details yet, so I have no opinion on whether or not that seems realistic.
It is too far out to get into details, but the GFS is showing good wind shear at all levels and if storms can break the cap we have a decent shot at severe weather. Any possibility of tornadoes is probably going to depend a lot on moisture quality and instability.
I will keep any eye on this and update the forecast tomorrow or Tuesday. Hopefully things will be a little more clear by then. I should be able to get some idea of the moisture situation by Tuesday-Wednesday.

Well the next possible chase day looks like next Friday. It doesn’t look that great right now due to a lack of quality moisture, which more than likely will continue to be a problem for a while. It’s just part of early spring chasing. It is too far out to get into details, but the kinematics look pretty good so I’d expect a good severe weather day if nothing else if this holds together. The GFS has been fairly consistent with this trough, so my confidence is increasing in some sort of activity next Friday.
I will get a forecast posted tomorrow and I am going to start posting long range forecasts regularly now. It probably won’t be every day, but I should get one up every couple of days at least.

It looks like tomorrow might be a chase day. I will work on my forecasting and get something posted tonight or tomorrow morning.