4/17/04 FCST:PLAINS

I'm opening this because this Forum has an eerie track record for picking the dates of deep moist convection well in advance. So this is for forecast discussions, and luck. Yes, luck. Do you feel lucky?
 
All but one ensemble member from this morning's 00Z GFS run brings the strong mid/upper flow into the southwest next weekend, so there is reason to think the pattern change we have been waiting for may develop. We will need a few days for the Gulf to recover from the current cold intrusion, and hopefully the system will move slowly enough to give tropical air time to move north in advance of the big system.
 
996 low in eastern Nebraska according to GFS. Temps progged to be in low 70's for me here on the In. Illinois border. Looks like next weekend might hold something in store for the Midwest as well as the Plains. Warmup is to begin in earnest here Wednesday so hopefully the gulf will have time to open up for good return flow. Things have been really quiet here in my area this season.
 
DVN's early forecast for that period shows a chance of thunderstorms. GFS shows DP should be in the range 55-60, maybe higher as the day gets closer.
 
Well I guess it is still to early at this point to speculate but I have a gut feeling that it may be a good day....( the 17th IS my b-day after all) :D
 
Dont knwo if this is a good thing or not but I had a dream about two weeks ago of an F3 tornado striking Wichita Falls. Large elephant trunck shape that touches down at the intersection of Seymour Hwy & Fairway near the KFDX TV-3 station and the traverses accross a few open fields & then accross loop 11 then kinda down Iowa Park rd and dissipates before it gets to Sheppard AFB. Also in my dream the event occurs on the 17th and I am film,ing the twister from the Kell Blvd & Fairway overpass on top of it with my chase partner. BTW I checked and my chase partenr has the day off Saturday.......Its also one week after the 25th aniversary of the Red River Terrible Tuesday event next week. Of course since I said all this it wont happen :p.
 
It's too soon to trust anything really right now for sure, BUT I do have my faith in Saturday. Wanna know why? It's cause the GEOL class at OU is having their second field trip, and that class is full of met majors. It never fails! Their first one was on March 27th and I think both days last year turned out to be good days (I forget what days). Ha! I'm so superstitious :p .

But being realistic, I'll hold my true opinion about this weekend for later on in the week when we can count on more than just how the butterfly flaps its wings.
 
Re: 4/17/2004 FCST:pLAINS

Originally posted by Amos Magliocco
Do you feel lucky?

LOL! I can't read that without thinking of the classic line from "Dirty Harry" as Clint Eastwood stands over a wounded bank robber, who is contemplating going for his own gun. "I know what you are thinking. Did he fire all 6 shots or only 5. To tell you the truth, I kind of forgot myself in all this excitement. But being this is a .44 magnum, the most powerful handgun in the world and would blow your head clean off, you've gotta ask yourself one question. Do I feel lucky? Well do ya punk?"

Ok, now after taking a trip down movie memory lane, I'll attempt to address the real topic. Hehe. Based upon what I've seen, I think next weekend has promise too. It's far to early to say with any certainty what exactly will happen, but I think it's safe to say that at least there will be a system on it's way. And what's even better is that it appears there may be more than one in the not too distant future. Hopefully this rather stagnant and boring pattern we've been in comes to an end next weekend. I think it may. And with that the gates into a very active period may be opened. Again, it's too early to get overly excited, but being the optimist I am, I think there's a good chance for some action. However, I am only willing to say that it will be somewhere between the Rockies and East Coast at this time! :) That's about as far out on a limb as I am willing to go as of right now.

-George
 
GFS - or whatever the heck they're calling it these days - 96 hr. shows precip nearing SE CO and TX panhandle - 108 shows it over the plains and 120 progresses over NW MO/IA. Looks like there will be some sort of response to low pressure developing alright. Crossing fingers -

Yesterday at spotter training in Lawrence, the wcm from Pleasant Hill said ... "so how many of you are already aware that next weekend might be interesting?" - you know we're stretching looking this far ahead, but I feel lucky.
 
Looks like a the threat for severe weather exists over a wide area late in this up coming week/weekend, from the southern plains into the midwest. If anything else, it will be getting warmer across these areas with temps climbing into the upper 70's as far east as the Great Lakes.

Latest 12Z GFS is also interesting by 180HR showing strong lee-side cyclogenesis (989MB) in the Plains, but thats over a week away, so no telling what will really happen...

Robert
 
The system seems to be getting pushed back again. Right now it looks as if southeast Nebraska down into eastern KS and OK may have a lot of fun Sunday. Temps could be pushing 80 with some nicely veering winds aloft. I'm a little pessimistic about low level moisture return however. I'm also a little worried about the system becoming negatively tilted the more the models may slow it down. Oh well, at least it's something to watch. I know I'll personally enjoy the nice warmup even if the storms don't materialize.. 8)
 
Stay out of Iowa... very bad!!!

I'll get more serious as to this discussion when the system is 48hrs. out; but for now as per the new GFS, it's looking like a chainsaw chase to northern Wisconsin (off limits for me).

..Blake..
 
This ain't quite scientific, but...

I'll throw my hat in with an active upcoming weekend, even without looking at any of this morning's model runs.

Why? The amount of chatter about it among the "weather community." As those of you who were at the Severe Weather conference in Norman early last month may remember, the statement was made several times about the May, 2003 outbreak that "we knew this was coming almost a week out." I distinctly remember the level of chatter about upcoming storms increasing before both the May 2003 and May 1999 events.

My first clue was when the "weather geek" of the station's meteorological staff e-mailed me and the station's primary chaser Sunday with a heads-up for possible severe wx next weekend. The word "severe" doesn't fall out of his mouth unless he's fairly certain. Then I look at the ICT HWO, and they're talking the possibility of severe Sat through Monday. The discussion is even more explict, describing a round on Saturday and a triple point developing in the area on Sunday.

Then I log on here to start a thread about the upcoming weekend, and find it's already been started! Already, five to six days out, we have convergence developing :)

This morning, I fully expect to find all the discussions in the area looking at the severe threat for the weekend. I won't be terribly disappointed if it's all fallen apart -- after all, this is April, but it's also time for the southern jet stream to shift back north, and that is typically an unsettled time.

Other unscientific indicators: we had a dip below freezing this weekend. When the winter pattern makes an appearance in Wichita the second weekend of April, I've noticed a tendency for the storm season to start fairly soon thereafter.

Those who are looking at chasing in this area this weekend, please do me a favor...drop by my web page, http://www.ksstorm.info/about.html and send me an e-mail. I'd like to talk with you about phone reports and possible video ;-)

Now, off to find some shred of scientific backing for my gut instinct reaction to the early chaser convergence :lol:


Scott
(Chase Coordinator, KWCH TV 12, Wichita)
 
A group of us stayed up late to watch the GFS roll in--dorkiness only true chasers could understand. And while the 0Z wasn't quite as perfect as the earlier run, it's still depicts a powerful system crashing into a juiced boundary layer on Saturday. The potential for severe weather, based on last night's run, looks good from northwest Texas through southwestern KS. Ensembles concur for the most part.

I'll open a second forecast topic for Sunday the 18th, since this looks like a 2 day show.
 
I have been looking forward to a servere weather event when i am not working. Fortunately i have sat-tues off and i will be watching the models the rest of the week and getting my equipment ready. If there is anyone from Missouri or eastern kansas that wants to tag along and share expenses give me an email. It is in my profile. Hope to see evryone out this weekend.
 
I was just thinking what Scott was thinking, I came to post a possible severe weather event in or near the plains and here we are, over 20 posts into this topic already.....I fortunately have the weekend off (for once) this weekend so I will be out if the weather continues to follow our predicted track. I will be where the weather is, I live in OK so I am hoping for somewhere in southern or central OK. We will see.
 
The latest GFS (120 hr) is putting the warm front action right over SE Nebraska, with a good punch of 60+ dewpoints. If you can get over the horrible visibility aspect, these kind of early north season setups can pay off big time (I'm thinking 8 Apr 99, SW Iowa outbreak).

Why I'm getting fired up this early is beyond me. I know I'm in for a letdown.
 
For the late nite dreamers:

The 0Z Tue 13 Apr AVN run is up....... so let's highlight a few things.

At 0Z Sun (5 days out):


1. NE and IA in left exit region of 250mb jet maxing over NE NM at 117kts.
2. 850mb LLJ from S near 45kts over N central OK and E KS.
3. Central pr near Goodland KS a bit under 996
4. Sfc T >75 and near 80 over W KS, E NE, and S IA (Sat evening)
5. LI -6 over much of IA (CAPE likely >2000)
6. Veering profile 60-70 degrees over KS, IA
7. Model showing 2 good days of Plains warming (Thurs and Fri >75 highs)

I'm not allowing myself to get excited yet, but if the models keep up continuity until Thursday, I'll start packing.
 
Things look like they'll be a bit closer to home for me, at least in terms of a not-so-marathon chase as March 27. If things maintain about the same position, I think I'm going ot head out regardless because I can.

Temps will stay pretty warm throughout the week, and looks as if the moisture will get in there as well. Everything else is still a ways away, enough not to warrent too close a look, but CAPE values look like they could punch 2000, so maybe that'll hold (or get better 8) )... my only concern is the April curse I've had for 4 years now, but with one chase under my belt, I'm hoping to shake that curse.

Still waiting til about Thursday before making any real decisions or excitment, but it gives me something to watch for the next few days. I imagine I'll go as long as the position of things remains about the same in later runs simply because I can be up and back in a day (less mulah). Also have a light week in terms of take-home work as I have exams Wednesday, and had one last Thursday, so nothing too major to keep me in chains. Just hope the car hangs on a bit longer! :)
 
I've mostly been looking at Iowa because that's about as far out as I can go for a Saturday event (a Sunday event would have to be even closer, of course). Given that I live in Indiana, a severe Saturday in Iowa might be my only chance for a while. That having been said, the 12Z GFS doesn't
instill a whole lot of confidence. The shear profile is very nice on
Saturday, in both direction and speed. 2M temps should be in the upper
60s, and there's the chance of some Gulf moisture being brought up by the
850 winds. The big concern is the location of the surface low. 18Z
Saturday, the low will be over southeastern WY, with a warm front
extending across the NE/KS border and just south of IA/MO. By 0Z, the low will still be in sern WY, but the warm front will have moved north into
southern IA and the cold front will be along the CO/NE border and across
the OK/TX panhandles.

It looks like Iowa will be out of the warm sector for most of the day, so
northern Missouri might be a better option. Then again, the target area
might have to be moved further west due to the timing of the system.
Still...this is 100 hours out, so there's plenty of time for conditions to
improve. Tomorrow's 12Z Eta will start picking up on this, and we'll see
where it goes from there.


Ben
 
I have to agree Ben, I'm gonna wait and see what the ETA does, since it is higher resolution and can get a better handle on things in general. I don't have time to head over into IA this weekend, but I'm hoping any leftover activity will be able to make its way into IN/MI region late Sunday.
Anyway, late FRI also looks like it could feature a couple of severe storms across the Great Lakes, with a nice trough swinging through and a bit of directional/speed shear and instability.


Robert
 
Whoa.

Major turn-around from the 12Z models (and the 18Z ETA) with regard to moisture availability for this weekend. The ETA and now even the GFS (which typically underforecasts moisture) are indicating at least lower 60s dewpoints starting Friday. ETA progs mid-upper 60 dewpoints across the entire southern plains by Friday evening. The Gulf looks like it will open wide, so we should see our first maritime tropical airmass of the season in the southern plains.

With this in mind, I believe this weekend(and into next week) WILL be awesome. Wind fields are now the concern, not the moisture. Mind you, wind fields already look decent (as progged by the models). I have been extremely cautious with this system (since models vary so widely 5-7 days out), but it looks like the moisture issue (which was my main concern) won't be one after all.

Gabe
 
Discussing the upcoming system with others off the forum; Not a fan of model wishcasting until down to the final 36-24 hours before a chase, however GFS is staying persistent (shifting the low slightly east). Now swaggering into a "believable" time frame -- I think this is one point that should be noted!

Similar to 30-April-2003, it appears there will be a secondary target of interest much further from the surface low along the warm front where the LLJ noses in at about 0Z. Waterloo is "squeezed" between the right entrance region of the mid-level jet and the left exit of a screaming LLJ. The flow is similar to 30-April-2003 where there were a couple fairly significant tornadoes in IL well away from the surface low NW MO/SW IA where 99% of chasers were. I had to blow off this day for the most part as I was due in OKC the following day to start work for Tempest Tours (still got on early evening convection E of ITC). Like the southerly surface flow with NNE flow immediately north of the warm front giving ample push from the surface.

Yet another significant factor to be noted is that if Td's which are progged verify along the warm front, a rough calculation would give ~2500-3000 j/kg of MUCAPE.

Wait... hold the beans here... I'm talking UP IOWA!?!?! That is whacked out and trippin'!!!

..Blake..
 
I guess I will throw in my two cents on the prospects for this coming wknd. There's no use repeating what others have said, especially with several days until the possible event. However, one interesting thing of note are the extremely saturated grounds along almost all coastal areas of Texas extending several hundred miles inland in some cases. Some areas have received 5-7 inches of rain in the past week+. I've never read any research about this but it seems to me the abnormally "wet" soils and terrain would undoubtedly help the moisture recovery and possibly drive dewpoints to higher levels more quickly than if the soils were drier.

One possible example of this can be seen by examining the NWS observation from the Brazoria County Airport on the immediate Texas coast (south of Houston) from tonight. The dewpoint at 5pm local was 44 but after the winds calmed down the dewpoint rose to 52 by 9pm. I think this dramatic increase speaks to the extremely waterlogged soils mentioned earlier. 8 degrees is a large difference! Certainly the models don't account for soil moisture/evpotransporation because it's hard to quantify. Then again I'm not an expert on the schematics of the models. Any comments?

Brazoria NWS station:
http://weather.noaa.gov/weather/current/KLBX.html
 
Good observation Austin. The southern plains should see a lot of sunshine the next couple of days to aide in evapo-transpiring the water on the ground. I believe there is some element in the eta model that tries to take this into account based on what soil moisture observations are available, but I think its success is mixed (no pun intended!).

That said, the Gulf is being hosed of the deep, tropical moisture, and despite the sun, will probably not reach full equilibrium in time for the weekend (still, 60ish dewpoints will not be too shabby). That said, the forecast pattern suggests that even if the first wave were to go by with limited moisture, the gulf will not get scoured this time, and there is still plenty of energy crashing into the southwest U.S. during the next week. So, stay tuned...
 
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