Here’s the updated SPC Graphic:

It’s not a lot of move from ear­lier this morn­ing, but now the area lays about where I really expected it to be….maybe still a bit fur­ther south than I expected. 7am (12z) model runs aren’t quite done yet, so I’ll be inter­ested to see if the low is out of posi­tion com­pared to where the mod­els had pre­dicted it. It was slightly off of the pre­dic­tions ear­lier this morn­ing, a posi­tion that would tend to favor the south­ward adjustment.

I’m going to shift my tar­get­ing think­ing just a bit south – 20–30 miles or so — now that the event is within the realm of the RUC. This model is more con­sis­tent with the NAM solu­tion, which was most con­sis­tent with other mod­els over the week­end. The faster GFS solu­tion seems to be the out­lier now. I still think the high risk area may be adjusted west a lit­tle in the out­look update due at 8am CT.

We’re just wait­ing to see where the cloud deck erodes now. Still a few hours from a firm tar­get­ing deci­sion, but I know this much: I’m not going to play with the hordes in north­east Okla­homa. I’ll take our road net­work over theirs any day of the week. My instinct to stay close because of risk to the Metro is stay­ing firmly in place. Best guess right now: I’ll be putting up with cell phone frus­tra­tion along US 160 a good por­tion of the day. I’ll take that to US 166, though.

This will prob­a­bly be the last dis­cus­sion in any detail – lot to get taken care of before my data ses­sion with Matt at 11, and looks like we may be on the road a bit ear­lier. Look for updates on Twit­ter: @scott_roberts and fol­low the video on the Live Tracker (but­ton at the bottom).

I will post an updated graphic from GRLevel3 some­time after the SPC out­look is issued, so you can see exactly where it sits. Some­times the small map on their site is hard to peg exactly where the line is in rela­tion to where you are.

This image, from NWS Nor­man, is the most con­cise expla­na­tion of today’s setup I’ve seen yet.

The Slight, Mod­er­ate and High-Risk areas today are indi­cat­ing only the num­ber of storms expected. Any­thing that goes is expected to be severe…much of it high-end. Usu­ally, the risk areas indi­cate fore­cast­ers’ best feel of both the change there will be storms and how intense they’ll be. Today it’s noth­ing more the % risk for any 25-mile cir­cle to get whacked.

I’m going to share a dif­fer­ent graphic with you today. This is one of the over­lays avail­able on my radar appli­ca­tion, GRLevel3. It is a bit con­fus­ing because it crams what is four images on the SPC web­site into one.

The red cir­cle, marked HIGH, in the south­east cor­ner of the image is the SPC high risk area. Very close to it, in orange, is the 30% tor­nado risk. Now look just south­west of Wichita. The light orange line clos­est to Wichita is the 15% risk of tor­nado line. The yel­low line, next west, is the SPC Mod­er­ate Risk line.

Now the item of con­cern, IMO. The Pur­ple line, marked SIG. That denotes the area in which SPC believes there is a “10% or greater prob­a­bil­ity of EF2 — EF5 tor­na­does within 25 miles of a point.”

Also of con­cern, from a prop­erty dam­age poten­tial stand­point: the light green line next to the west – 45% prob­a­bil­ity of hail. And though I don’t show it on this view, the area is hatched on the SPC site, mean­ing a “10% or greater prob­a­bil­ity of hail 2″ or larger within 25 miles of a point.”

So, in spite of the high risk being moved to our south­east, I think it’s pre­ma­ture to let out our col­lec­tive breath. The haz­ards if some­thing goes today are in the sig­nif­i­cant category.

I expect to see the High risk area come back just a bit to the west. But from the stand­point of chas­ing in the metro area and the pop­u­la­tion impact of the worst weather, I’m lik­ing where it is a lit­tle bet­ter than where I thought it would be. The high-risk bulls­eye will dis­tract many of the unin­formed peo­ple who will clog the roads and make it hard for those of us whose job is to inform oth­ers of the events in real-time to do what we do. The casual chasers will focus on the high risk and leave us alone. That leaves the untrained “chasers” – called a num­ber of other deroga­tory names by many – the peo­ple for whom “Twister” was a train­ing film. ‘Nuff said. I still expect the roads to be a zoo, but with the high-risk bulls­eye to our south­east, we’ll lose some of the gridlock.

I’m not mak­ing any fine-tuning deci­sions on my tar­get­ing until the 0z (7am) mod­els are out, but I will say my think­ing hasn’t changed a lot con­cern­ing where and how we’ll approach it. We may not get on the storm of the day…but if it looks to me like storms will directly threaten Wichita, I’ll defer to stay­ing in the metro. It’s a day when I take my warn­ing respon­si­bil­ity – and if some­thing hap­pens, my respon­si­bil­ity to help – more seri­ously than get­ting the great­est video. There are a lot of days those two moti­va­tions are com­pet­ing in me, but today it’s a no-brainer for me.

Time to work so I can have the deck clear by 11 for an in-depth dis­cus­sion with Matt. I may post a short update about 7:30 or 8, oth­er­wise the next one will likely come as we get ready to roll – right now we’re plan­ning on being in the field by 2:30-3pm.

Pretty much in line with what I expected, the word­ing of var­i­ous weather ser­vice fore­cast prod­ucts has taken another step up in tone, and I’m going to echo the step-up. Tomor­row is a poten­tially dan­ger­ous setup for a lot of peo­ple. Today is the day to make plans about shel­ter — to con­sider the places you plan to go tomor­row and find out, if you don’t know, where shel­ter loca­tions are in those places. A hand-held or desk­top weather radio is a good invest­ment — and of course in Kansas and Wichita, you can rely on KWCH and KFDI to have it very well cov­ered (gra­tu­itous plug now finished).

There are still some dif­fer­ence in model tim­ing and the result­ing fea­ture place­ment. They’re grad­u­ally com­ing closer, though. The way I see it now, the dif­fer­ences are between the worst weather being from just west to just east of Wichita and it being in east­ern Butler/Greenwood coun­ties. There are also some dif­fer­ences with the south­ern extent of the storms. I’m not sure whether I’m being chaser-selfish or more con­cerned about pro­tect­ing life and prop­erty where I live — but I hope the sce­nario plays out closer to the NAM solu­tion in Okla­homa and closer to the GFS solu­tion in Kansas. That has the dual ben­e­fits of keep­ing the Okla­homa chasers off south­ern Kansas roads and in their own back yard and shift­ing the worst weather to less-populated areas all around.

Should the oppo­site hap­pen, we may be look­ing at a May 3, 1999 sce­nario dis­placed a bit to the north and east.

Overview: Storm Pre­dic­tion Cen­ter Graphics

Cat­e­gor­i­cal Risk

Total Prob­a­bil­ity of any Severe Weather

First change to note since yes­ter­day: the Mod­er­ate risk area is slightly east of where the risk area was painted yes­ter­day. Wichita is now on the west edge instead of near the mid­dle. Most NWS fore­cast­ers have been buy­ing the GFS model through­out the ramp-up to this event. It has been the most con­sis­tent through­out. The NAM (or now that we’re in the 2-day range, the NAM/WRF) model is a bit slower evolv­ing the fea­tures and leaves the risk area back to the west, basi­cally what’s out­lined by the Slight risk above.

I would not focus so much on the 45% prob­a­bil­ity of severe weather for the Mod­er­ate Risk area as I would on the hatched part of the graphic on the right. That indi­cates the expec­ta­tion among fore­cast­ers that pretty much what­ever goes up tomor­row will be capa­ble of high-end severe weather (EF2-EF5 tor­na­does, 2” + hail within 25 miles of any point in that hatched area).

Why is this? Here are graph­ics show­ing the fac­tors I find impor­tant. The val­ues I list under­neath them are my esti­mates for Wichita.

Sur­face Tem­per­a­ture: 78–82 Sur­face Wind: SE gust­ing to 30

700mb Tem­per­a­ture (an indi­ca­tion of cap strength): +5 C. 700mb Wind: SW @ 50 kts

GFS CAPE:  1000

GFS CIN: 0 to-5

NAM CAPE: about 2000

NAM CIN: 0

GFS LI – best just east of Wichita

NAM LI – best just west of Wichita, but a respectable –7 overhead

LONG-TRACK STRONG TORNADOES WILL BE POSSIBLE... 
PARTICULARLY FROM OK PORTION OF I-40/44 NWD 
INTO SCNTRL/SERN KS DURING THE EARLY EVENING.

POTENTIALLY LONG-TRACK TORNADOES DURING THE AFTERNOON AND EARLY
EVENING ON MONDAY. SUPERCELL THUNDERSTORMS ARE EXPECTED TO DEVELOP
DURING THE MID TO LATE AFTERNOON JUST AHEAD OF THE DRYLINE AND RIGHT
MOVING STORMS WILL QUICKLY MOVE OFF TO THE NORTHEAST AT 40 TO 50KNOTS.

NWS Nor­man (empha­sis mine):

SEVERE THUNDERSTORMS ON MONDAY AFTERNOON AND EVENING...MAY MOVE AT
SPEEDS GREATER THAN 45 MPH...LEAVING LITTLE TIME FOR PEOPLE TO REACT
TO WARNINGS. YOU ARE ENCOURAGED TO THINK AHEAD TO WHERE YOU
WILL BE ON MONDAY...HOW YOU WILL RECEIVE WEATHER WARNINGS...
AND WHERE YOU WILL SHELTER IF A STORM APPROACHES YOUR LOCATION.

My tar­get for tomor­row stands at this point. Essen­tially a back porch chase.

…but the ques­tion is: where? With the hordes of chasers to be in our area Mon­day, space on the roads may be at a pre­mium, and a bad fore­cast deci­sion may not be recov­er­able due to the traffic.

That said, as the mod­els sit at this moment (and the lat­est mod­els are rolling out as I write this, so I have not seen them) I am going to be some­where in a box bounded by K-14, US 77, US 56 and US 166. My best read at this point puts the Wichita area under the gun, per­haps in a sig­nif­i­cant way. It may come down to what bound­aries are laid down by tomor­row night’s storms and just how much clear­ing we have ahead of the dry­line. One thing to be care­ful of: some of our biggest storm days have been cloudy longer than was thought would give the atmos­phere time to recover. Andover was one of those days. I have some con­cerns of a repeat.

We’ll see how that call drifts over the next 40 hours or so…