4/18/04 FCST: N PLAINS & MIDWEST

[Amos Magliocco]

For the potential second round of severe weather this weekend...

 

[Robert Dewey]

The threat looks decent...As of now. Event is still 6 days away, so I am not too excited just yet.

Robert

 

[Joel Wright]

The low pressure is weakening and occluding by this point. But, moisture is readily available. Looks like a non-event for my part of the midwest. I'm not too impressed at all at this point. The best day will be Saturday down in Kansas and Oklahoma, and maybe parts of southern NE.

 

[Robert Dewey]

Originally posted by Joel Wright
The low pressure is weakening and occluding by this point. But, moisture is readily available. Looks like a non-event for my part of the midwest. I'm not too impressed at all at this point. The best day will be Saturday down in Kansas and Oklahoma, and maybe parts of southern NE.

I just checked the latest 12Z GFS and your right. The low looks like it is weakening and filling in. I'm not gonna give up on it just yet though , its a little under a week away, and plenty of time for things to change for better or worse.

Robert

 

[Amos Magliocco]

I actually thought the 12Z improved Sunday's setup a little, with the system coming out more negatively tilted and improving the wind fields up there in NW IL to E IA. Plenty of time for return, strong deep layer shear, and a surface low still more than adequate. I agree it's more likely to be the typical post-plains, upper-midwest, unidirectional squall line.

However, if we're seeing a gradual slowing trend--which would not be at all surprising--Sunday could become the marquee day and Saturday a nocturnal affair in deep west Texas. I'm hoping that doesn't happen, but it's possible. Anything's possible six days out--LOL!

 

[Scott Roberts]

Sunday forecast

Originally posted by Joel Wright
The low pressure is weakening and occluding by this point. But, moisture is readily available. Looks like a non-event for my part of the midwest. I'm not too impressed at all at this point. The best day will be Saturday down in Kansas and Oklahoma, and maybe parts of southern NE.

I'm liking Sunday better for our area. Models seem to be slowing down just a bit, and with the earlier mention of a triple point in the ICT CWA, and our forecaster's feel that Satruday will be a late-day event, I'm holding out for Sunday (besides, I get more overtime that way )

 

[Robert Dewey]

Just checked the latest 18Z (I will be checking models every run every day until the event happens, or doesn't happen... ). The system speed has actually increased some, which is opposite to what Amos (and I) were thinking. By 00Z Monday (around 7PM EDT I believe) the SFC low is located in central WI with a mslp of 997MB. Have yet to look at moisture charts and instability, but overall synoptic setup appears favorable for severe thunderstorms from eastern IA, northern MO, ENE into IN and lower MI. As of right now, supercells look possible (again, just based on synoptics and jet structure only) in the eastern IA and northern MO area, which should form into a squall line and move into the other mentioned regions. The low actually deepens over lake superior some, and given the strong nocturnal low level jet, suspect that a relatively strong squall line could traverse across southern lower MI/IN/northwest OH...But all this is 6 days away and I'm getting too far ahead of myself .

Below is a forecast map which I generated real quick, and it will update as I change the forecast (when I ever get the chance), since it is an absolute image URL on my server. So to see my latest forecast for the event, just check this post.

[Broken External Image]:http://www.waveformpc.com/outlookSunday.GIF

 

[Joel Wright]

Well taking a look at the new 00Z runs have restored some hope for Sunday. One thing I noticed the models seem to be "forgetting" is the MAJOR influence of the very cold great lakes. This will have a big impact on where exactly the warm front ends up lying. Moisture seems to be well in place, and relatively deep as well. From the surface to 200mb there's nearly a 90 degree veer. There appears to be nice divergence. Definitely a lot of positives there.

Right now I'm thinking the low will end up tracking further south, along a further south placed warm front. A very early guess would be far southern Iowa down into Missouri and west central IL. I feel a little goofy making a guess this early, but ah what the heck. It's been a LONG time since we've had anything exciting to forecast around here!

 

[Robert Dewey]

Originally posted by Joel Wright
I feel a little goofy making a guess this early, but ah what the heck. It's been a LONG time since we've had anything exciting to forecast around here!

Thats what I say, just look at my previous post!

Robert

 

[Jon Miller]

NOAA's Climate Prediction Center US Hazard Assessment is showing severe storms from NE New Mexico NE to western Michigan on April 18,19
and from central Texas NE to Ohio on April 21-23 of next week.
http://www.cpc.ncep.noaa.gov/products/expe...nt/threats.html

So it looks like a potentially active chase week (and a lot of travel) is in the brew ! Good luck & take your credit card - gas prices are going up, up up !!!

Jon Miller
WTØRNA

 

[Robert Dewey]

Thanks for the link Jon. They mention severe weather 9 times, and they use pretty strong wording such as

Severe storms are expected for parts of the Central Plains from April 18-19.


Severe storms are expected for most of the Mississippi and Ohio Valleys from April 21-23.

I will certainly be watching this situation!

Robert

 

[Jeff Miller]

Fortunately next week on the 20th, my chase partner and I were slated to attend a Spotter class in Iowa. Now, if this pans out, we may well be doing some serious chasing. Looks like I'll be out next week....will keep all posted on wether or not this will be my first serious chase week of 2004.

Dare I allow myself to get excited?? just a tinge at this point...but I will say its looking better!

 

[Robert Dewey]

I will probably update my forecast graphic as the 00Z GFS pours in tonight, I'm getting kinda bored . Make sure to check it, and add constructive criticism.

Robert

 

[David Schuttler]

Guess I did get lucky in my vacation time this year and thank you Bank of America for raising my limit last week.

I would pick a week in May but the company I work for doesn't allow vacations after April.

 

[Joel Wright]

Looking at the latest 00z GFS run that just came in shows that things are almost nearly identical to last nights 00z run. By late sunday afternoon the GFS plots the warm front north well into Wisconsin. I still find this very hard to believe with the combination of MAJOR lake cooling and ongoing convective clusters traversing the boundary further enhancing low level cool pools. But since the LP is still progged to ride all the way into southern MN before occluding, I'll hold on to a little hope that the storms fire as far north as the south half of Iowa. I would target the afternoon warm front/triple point which will likely end up somewhere in Iowa, near DSM. All other parameters still look pretty good. If things don't change there will be some tornadoes in the midwest on Sunday.