04/29/05: TALK: OK/MO/AR/IL/KY/TN

[Ben Prusia]

Both 12Z NAM and 6Z GFS show the storm not strengthening enough, Low Pressure now at 998mb by the 12Z NAM, centered near Little Rock, meanwhile 6Z GFS is showing system barely able to make it below 1004mb, now I am little hesitant on going.

 

[Billy Griffin]

THERE IS A SLIGHT CHANCE OF SEVERE THUNDERSTORMS THROUGHOUT THE QUAD
STATE FRIDAY AND FRIDAY EVENING. DAMAGING WIND GUSTS AND TORNADOES
WILL BE THE PRIMARY THREATS...BUT LARGE HAIL CAN NOT BE TOTALLY RULED
OUT. THE BEST CHANCE FOR SEVERE WEATHER WILL BE OVER WESTERN
KENTUCKY AND FAR SOUTHEAST MISSOURI...AS A STRONG SURFACE LOW
PRESSURE CENTER LIFTS RAPIDLY NORTHEAST. THE STORMS WILL BE RACING
TO THE NORTHEAST AT AROUND 50 MPH.

OUCH !!! Read that last sentence... 50 mph! :shock:

It looks like the Memphis, Little Rock and Paducah NWS offices are thinking this thing will be a little farther east than central/eastern AR or the MO bootheel. If so, your terrain goes down hill in a hurry!

I know those roads, and there's absolutely no way (unless you have a helicopter) that anyone can keep up with storms moving THAT speed.

I'm not giving up on it yet, I'm just reading from the Paducah HWO issued this morning. Memphis pretty much mentions the same thing, and Little Rock mentions storms will likely initiate along the MS River, east of their area. Guess we shall wait and see. :?

 

[Justin Walker]

Originally posted by Aaron Kennedy
I haven't kept tabs on the system, but quick glance at NAM from last night (to me) shows a squall of death. Winds are nearly unidirectional from SFC-300mb, and sfc winds are far from being backed. Directional shear sucks.

Well, Aaron hit the nail right on the head. Good speed shear only definately screams squall. Also, with all the forcing and dynamics with this system, initiation will be around 2pmish. So anyone chasing this will have to get out very early.

I think by tomorrow, spc will give a moderate for large hail and winds. Definately could see a few tornados but, unidirectional winds throughout atmos will really kill a major outbreak. All this system needs is just some backed winds say sfc to 850mb, then it's on.

 

[Robert Dewey]

Latest 12Z NAM really looking like crap... Hope this trend doesn't continue... System quite a bit weaker this run. UKMET, ECMWF, GEM, GFS, and now the NAM all agree on a much weaker system, around 1000mb at best. But, the system still hasen't completely made it on shore yet, so things could still change. This is one of the reasons I am hesistant on posting a FCST until 18-24 hours prior to the actual event...

 

[Justin Walker]

Originally posted by rdewey
This is one of the reasons I am hesistant on posting a FCST until 18-24 hours prior to the actual event...

Yea...i'm with you on that one. I think the majority of us feel the same way. Probably why a 2-1 ratio with talk to fcst. A lot of things could still change

 

[Bill Schintler]

RE: 04/29/05

By mid-day, it's looking like a thick CI shield in association with the upper-jet, covering the SERN half of OK, SRN MO, and points to the S.

- bill

 

[Scott Taylor]

Originally posted by Aaron Kennedy
I haven't kept tabs on the system, but quick glance at NAM from last night (to me) shows a squall of death. Winds are nearly unidirectional from SFC-300mb, and sfc winds are far from being backed. Directional shear sucks.

Hey all,

I'm just getting back into the swing of 'attempting' my own forecasts from model data, so I know I'm very possibly missing things here and there.

Aaron, I agree with the directional shear observation, to an extent. When observing a forecast sounding for Memphis from NAM output (36 hr), I do see about 75 degrees or so of turning though through 950 mb. The upper levels are fairly uni, but doesn't the turning, while not plentiful, make this not unidirectional?

Help me! =)

Thanks
Scott

 

[Aaron Kennedy]

Scott: Along the warm front you'll have better backing at the surface which is why I mentioned it... otherwise... farther the way you get from that boundary across the warm sector it looks unidirectional.

Aaron

 

[Robert Dewey]

Yeah, the only directional shear I am seeing is along the warm front. I just took a look at the MEM sounding (12Z NAM at 36FH), and the SKEW-T shows a very strong unidirectional component/very little directional shear. A look at the hodograph, however, shows *some* rotation, but not much. Helicity (0-3km) is up around 300m2/s2, but that's likely due to the very strong speed shear (0-3km is nearly 50knts of shear!). The sounding is also very unstable, and uncapped, through most of the day at MEM, and with CAPE in excess of 3000J/KG, it wouldn't take much forcing to touch off storms along the cold front.

 

[Tony Laubach]

There's your MOD risk guys... enjoy!

 

[George Tincher]

SPC has just upgraded to moderate on the 1730z. They are still mentioning tornadoes likely. The probability map is 45% hatched.

Their latest forecast sounds like it involves lots of complicated issues. But it seems they certainly feel the tornado threat is still very much real.

Oh well, we still have another model run to look at later. And from there on it's real time observations for me. LOL.

 

[Scott Taylor]

cool, thanks for the explanations. I did see that cinh was very low and figured things would be squalling, probably well before it hits Memphis.

 

[Jason Montano]

If I understand what the SPC wrote in the 1730z Day 2 it sounds like the early morning precip will not be a problem. They are talking about that precip forming another boundry and that being one of the focal points of the convection. That was one of my big concerns of seeing a grunge fest or not enough heating. However, I need to make up my mind soon if I'm to make this one it's a long drive.

 

[Billy Griffin]

Still waiting to hear back from my chase partners, then my initial plans are now to leave Norman by 6am, head to Little Rock and stop there for data and forecast updates.

I think an earlier departure is in order, considering it's anyone's guess when initiation may erupt and I'm guessing it won't hold off until 4-5 pm or later. :roll:

If we can get to Little Rock by 11am, then we'll have time to stretch the legs, grab some data, get some lunch, and then be on our way to target areas as forecasts are modified. I believe it will be an active day, but it'll take some luck and cooperation from Mother Nature to get in on the big stuff and be able to stay on it with tricky roads and terrain.

Departure from Norman planned for 6am tomorrow. High Risk almost certain for tomorrow's morning outlook.

 

[Eric Edgar]

For those of you who may also be birders, today it was announced that the Ivory-billed Woodpecker has been rediscovered, more than 60 years after it was considered extinct. At least one male has been sighted numerous times in a 16 square mile tract of mature bottomland forest in east-central Arkansas -- quite possibly right in the middle of the HIGH RISK bullseye tomorrow.

Here's hoping that a long-track F3 misses that little dude.

www.ivorybill.org
(or any major media website for more info)