Thursday's setup - UPDATED AGAIN

Tuesday mid afternoon update

We are still two days away. The 18z NAM looks ok, the SREF is coming out now, and we will have to wait on the GFS a bit.

The SREF still is a bit quick with the fronto..just a hair I think. It brings up the low 60 dewpoints before quickly being pushed out to upper 50s.

Likely this would be due to the frontal passage. I think ultimately after looking at my last bit of model data from the SREF, NAM, RUC, and a few others...here is what I think...

I think initiation starts about 21Z-0Z Thurs/Fri. I believe it will initiate just a hair to our west...not much.

Maybe Lawrenceish or just north down to around Ottawa.

These will be just the beginning with discrete cells filling into a line closer to 0Z. I think KC will catch the storms around 23-01Z. I believe they will gain strength as they pass.

I think it may come all together in a line around Joplin up to Chilicothe. I think before they line up, they may be quasi supercellular, but would want to come together on the frontal boundary.

This one is a toughy. If the darned models could just agree on the location, speed and strength of the deeping ULL, it would be much easier.

I think ongoing, I am going to go more observation based. I have enough of the setup in mind and know where the spots are to watch...now I can rely more on the RAP for surface analysis, sat images/wv, and soundings to see how the front and moisture are behaving.

It is too marginal to call right now. We are right on the edge of something to write home about or sleep through.

Moisture is the key.

END UPDATE


Monday evening update.

There has been some questions and concerns about dewpoints and moisture return. Here is the latest GFS MOS guidance. I will highlight the dewpoint for the timeframe in question...

 KMCI   GFS MOS GUIDANCE    4/28/2008  1800 UTC                  
DT  /APR  30                /MAY   1   
HR   00 03 06 09 12 15 18 21 00 03 06 12 18
N/X  65          48          75       58
TMP  62 55 53 50 50 62 71 74 72 64 62 60 67
DPT  37 39 41 42 43 47 50 51 52 52 53 54 62 
CLD  FW CL CL CL SC SC FW FW SC BK OV OV OV
WDR  15 13 14 14 16 17 16 17 17 16 16 15 16
WSP  12 12 13 13 16 18 19 23 19 17 16 18 21
P06  1     0     3     4     5    12 20 20
P12  1           3           8       23
Q06  0     0     0     0     0     0  0  0
Q12  0           0           0        0 

I think the GFS MOS is off with the cloud cover progs, as I don't think it is picking up the surface heating I think we will see that day with the residual ridging from previous days.

From the last sounding below, the most recent forecast soundings bring the CAPE up to over 1700 and raise the PW amounts to 1.11 inches. Also, it reduces the cap as well. Helicity also increases to 460+.

Looking at the 72 hr RUC, it begins to bring the 60 + dewpoints into SW Oklahoma starting Thurs morn.

END UPDATE



Ok..here is what I think. Thursday night, we have potential of severe storms in the area. The SPC currently has a statement on the 4-5 day for this and in reviewing the models along with surface/LRC analysis - I see it too.

First, lets start with the 500mb.

Notice how we are very near the speed max around the base of the ULL? This will provide ample upper air support as it shows 50-60kt winds aloft. Plenty for providing upper air bulk sheer. Also, notice the blue arrows. This is to show how this trough looks to be going negative for tilt providing ample lift.

Now a quick view of the 700mb.

Notice all the status deck to our NW. This should allow for daytime warming in this area as being part of the warm sector of this surface low.

Now the 850.

Notice again, the lift ahead of the 850 vorticity. We should have ample lift/forcing with this in place. Notice the 50kt LLJ forming ahead of the frontal zone.

Now the 10m.

I have drawn what I believe to be the surface features. I show the cold front, the dry line, and what looks to be an occluded front on the top side. Notice where the dryline is. I think this puts this area right in the target area. I do believe the dryline will retreat at dark and be overtaken by the cold front as shown by the brown and blue arrows. Notice the triplepoint location.

This may lend itself to a typical supercellular view early merging to a linear or MCS type of complex more toward dark.

I think this has potential. I don't expect the 500mb to change much in location. The models are getting closer in location, but more importantly..in my mind, two factors show this is viable to me.

1. The surface analysis trending shows this is a strong match for a cold front. In the past, we didn't get much rain due to the fact the upper air was too far south. This will be shown below from the last cycle.

2. Look at the last cycle and where the 500mb was located. Too far south, but part of the same alignments as this storm just 54 days ago or so. Notice the deep central trough, notice the E PAC ridging into Canada. Notice the strong Aleutian low.

This is the same part of the pattern as later this week. No doubt.

http://www.spc.noaa.gov/cgi-bin-spc/getuadata.spc?MyDate1=080307&Time1=12&MyDate2=&Time2=12&Align=V&Levels=500

Lets see what evolves, but I think this has a shot...

Last quick thought...look at the forecast sounding for this timeframe. Notice the highlighted values...

MODEL GRIDDED SOUNDING PLOTTING (Ver 5.46-LINUX-X11)

Current filename: /home/data/hrs/avn/12042708.gm0
Reading from grid file:/home/data/hrs/avn/12042708.gm0
Searching the city database file for: KMCI ...
Searching file for grids...
Date: 4.5 day valid 0Z FRI 2 MAY 08
Station: KMCI
Latitude: 39.32
Longitude: -94.72
-------------------------------------------------------------------------------
LEV PRES HGHT TEMP DEWP RH DD WETB DIR SPD THETA THE-V THE-W THE-E W
mb m C C % C C deg knt K K K K g/kg
-------------------------------------------------------------------------------
0 1000 -45
SFC 963 282 20.6 17.2 81 3.4 18.3 169 17 296.9 299.3 292.9 334.2 12.90
2 950 395 19.8 16.4 81 3.4 17.5 173 29 297.3 299.6 292.6 333.4 12.45
3 900 859 16.1 15.1 94 1.0 15.4 181 40 298.1 300.3 292.6 333.2 12.06
4 850 1344 14.0 12.0 88 2.0 12.7 198 45 300.8 302.7 292.1 331.4 10.42
5 800 1856 13.1 5.3 59 7.8 8.6 217 43 305.1 306.4 290.6 326.1 6.97
6 750 2395 9.3 -0.7 50 9.9 4.1 225 46 306.6 307.5 289.2 321.5 4.85
7 700 2963 4.8 -7.0 42 11.8 -0.4 228 48 307.8 308.4 288.1 317.9 3.22
8 650 3562 0.5 -16.1 28 16.6 -5.4 223 49 309.5 309.8 287.1 314.9 1.67
9 600 4198 -3.6 -21.4 24 17.8 -9.0 211 50 311.9 312.2 287.3 315.8 1.15
10 550 4879 -8.3 -25.0 25 16.6 -12.7 206 50 314.2 314.4 287.9 317.3 0.92
11 500 5611 -13.6 -27.1 31 13.4 -16.8 208 51 316.4 316.6 288.5 319.3 0.83
12 450 6403 -19.9 -30.0 40 10.1 -21.9 212 52 318.2 318.4 288.9 320.7 0.70
13 400 7265 -26.6 -35.4 43 8.8 -27.9 210 59 320.4 320.5 289.4 322.1 0.47
14 350 8213 -34.5 -40.9 52 6.4 -35.1 212 62 322.2 322.3 289.8 323.4 0.31
15 300 9270 -43.1 -47.2 64 4.1 -43.4 220 65 324.6 324.6 290.3 325.2 0.18
16 250 10471 -53.1 -54.0 89 1.0 -53.1 226 64 327.2 327.2 291.0 327.6 0.10
17 200 11873 -63.1 -63.5 96 0.3 -63.1 225 61 332.8 332.8 292.5 332.9 0.04
18 150 13658 -57.9 -85.7 2 27.8 -58.2 231 40 370.4 370.4 300.7 370.4 0.00
19 100 16214 -57.8 -85.6 2 27.9 -58.2 258 22 416.1 416.1 307.3 416.1 0.00
TRP 0
WND 0

Sounding variables and indices
1000-500 mb thick: 5656.62 m
Freezing level: 644.13 mb = 3636.25 m = 11929.80 ft
Wetbulb zero: 704.91 mb = 2905.10 m = 9531.07 ft
Precipitable water: 1.06 inches
Sfc-500 mean rel hum: 48.10 %
Est. max temperature: 27.51 C = 81.52 F
Sfc-Lift cond lev (LCL): 915.52 mb = 712.61 m = 2337.94 ft T: 17.30 C
700-500 lapse rate: 6.95 C/km
ThetaE index: 19.30 C Layer 950.0- 600.0 mb
Conv cond level (CCL): 856.25 mb = 1281.98 m = 4205.93 ft
Mean mixing ratio: 11.99 g/kg
Conv temperature: 24.02 C = 75.24 F
Cap Strength: 2.26 C
Lifted Index: -3.84 C Risk: Severe thunderstorms possible
Lifted Index @300 mb: -4.78 C
Lifted Index @700 mb: -0.62 C
Showalter Index: -3.10 C Risk: Severe thunderstorms possible
Total Totals Index: 53.22 C Risk: Scattered heavy thunderstorms
Vertical Totals Index: 27.59 C
Cross Totals Index: 25.63 C
K Index: 27.76 Risk: 40-60 % chance of thunderstorms
Sweat Index: 368.94 Risk: Showers and thunderstorms possible
Energy Index: -2.42 Risk: Severe Thunderstorms probable

Parcel Indices
Parcel: using 100 mb layer
CAPE (B+): 1306.76 J/kg
Max Up Vert Vel: 51.12 m/s
Conv Inhibition (B-): 72.13 J/kg
Cap Strength: 2.11 C
Lift Cond Lev (LCL): 884.53 mb = 1006.38 m = 3301.73 ft
Lev Free Conv (LFC): 709.53 mb = 2851.39 m = 9354.83 ft
Equ Level (EL): 199.53 mb = 11887.07 m = 38999.09 ft
B at Equ Level: 1294.71 J/kg
Max Parcel Lev (MPL): 139.53 mb = 14113.84 m = 46304.68 ft

Wind level data
Storm motion: 241 at 35 knt
----------------------------------------------------------
TRUE/GROUND REL STORM REL
LEV P H DIR SPD U V DIR SPD U V
mb m knt m/s knt m/s
----------------------------------------------------------
0 1000 -45
1 963 282 169 17 -3.5 17.1 90 34 -33.9 -0.0
2 950 395 173 29 -3.4 29.0 109 36 -33.8 11.9
3 900 859 181 40 0.5 40.2 128 38 -30.0 23.1
4 850 1344 198 45 14.0 42.6 147 30 -16.5 25.5
5 800 1856 217 43 26.1 34.6 166 18 -4.3 17.5
6 750 2395 225 46 32.5 32.4 187 15 2.0 15.3
7 700 2963 228 48 35.6 32.2 199 16 5.2 15.1
8 650 3562 223 49 33.6 36.0 189 19 3.1 18.8
9 600 4198 211 50 25.3 42.7 169 26 -5.2 25.6
10 550 4879 206 50 22.0 44.6 163 29 -8.5 27.4
11 500 5611 208 51 23.8 44.9 167 29 -6.6 27.8
12 450 6403 212 52 28.0 44.4 175 27 -2.5 27.3
13 400 7265 210 59 29.9 51.2 179 34 -0.5 34.1
14 350 8213 212 62 32.9 52.1 184 35 2.5 35.0
15 300 9270 220 65 41.2 49.8 198 34 10.7 32.6
16 250 10471 226 64 45.6 44.5 209 31 15.2 27.4
17 200 11873 225 61 42.5 43.1 205 29 12.1 26.0
18 150 13658 231 40 31.0 25.5 184 8 0.5 8.4
19 100 16214 258 22 21.9 4.6 34 15 -8.5 -12.5

Wind Parameters
Mean winds (0-6000m): 210.6 at 46.6 knts
Storm direction: 240.6 at 34.9 knts
Shear (0-3000m) pos: 7.0 neg: 0.3 tot: 7.4 10-3/s
Storm rel Dir Shear (0-3000m): 103.6 deg
Storm rel helicity (0-3000m) pos: 414.9 neg: -6.6 tot: 408.3 m^2/s^2
ave: 136.1 10^-3 m/s^2 rel: 0.79
Storm rel vorticity (0-3000m) horiz: 11.0 stream: 8.7 10^-3/s
Energy-Hel index: 3.24
Bulk Rich Number: 13.14
Bulk Shear: 99.47 m/s

Storm Parameters
-------------------------------------------------------------------------------
Depth Mean Inflow Shear Helicity Vorticity
AGL Dir Spd Dir Spd Pos Neg Tot Pos Neg Tot Ave Rel Hor Strm
m knt knt 10^-3/s m^2/s^2 m/s^2 10^-3/s
-------------------------------------------------------------------------------
500 176 31 113 36 22.1 0.0 22.1201.3 0.0 201.3 402.5 0.99 22.4 22.1
1000 183 37 124 35 15.4 0.0 15.4312.5 0.0 312.5 312.5 0.94 18.3 17.2
1500 191 39 133 31 11.6 0.0 11.6369.4 0.0 369.4 246.3 0.84 17.1 14.3
2000 199 40 141 27 9.8 0.0 9.8396.6 0.0 396.6 198.3 0.83 14.7 12.3
2500 205 42 148 24 8.4 0.0 8.4411.1 0.0 411.1 164.4 0.84 12.5 10.5
3000 209 43 155 22 7.0 0.3 7.4414.9 -6.6 408.3 136.1 0.79 11.0 8.7
4000 212 44 162 22 5.3 1.9 7.1414.9 -63.5 351.4 87.8 0.53 9.9 5.3
5000 211 46 162 23 4.3 1.8 6.0422.6 -80.7 341.9 68.4 0.49 8.4 4.1
6000 211 47 164 24 3.9 1.5 5.4454.3 -80.7 373.6 62.3 0.51 7.4 3.8

Lots of PW, plenty of moisture.

Look at the RH - shows that we should not have any stratus lingering around since the RH is below about 80%.

We will be capped, but weakly.

CAPE is fair, but would expect it to be a bit higher later in the evening as daytime heating really takes hold

Look at the 0-3KM Helicity - 408. Very nice for turning/veering with height.

Good sheer...

We will see.

Later...

Severe weather next week?

I will try to get some analysis out in the next day or two..but the SPC is noting some activity here in the 5-7 day outlook.

I am buying it. It fits. I gave a bit of analysis on the KSHB blog, but will put in a bit more Sun or Mon.

Hail Storm

Geez, it was last week sometime...maybe Monday, we had a little hailstorm.

While I was not looking at any radar or any data at all, its amazing what could be learned from observation.

Where I would look at a radar and see the storm and its path, observation told me when the wind shifted from east to south, I was seeing a bit of outflow. I knew something was heading my way.

Where I would look at the skew Ts to see the profiles, observation told me that it had been mainly clouding all day with an east wind. That told me we were near a warm front. I knew surface based convection was going to be weak.

When the storm rolled in, where I would look at VIL proviles, observation showed the hail fell but was very soft when it hit and actually exploded off the windshield. It was very soft ice. Seeing that, I knew there had to be some inversion of warm air aloft that was warming the hail on the way down.

Knowing there was little surface convection and that we had hail, it had to be elevated instability. That would explain the warmer air aloft melting the hail a bit on the way down.

The storm passed through leaving a bit of a clearing to see the back end of the storm. Knowing the hail core comes before any backend circulation, I looked up to the sky in the clearing.

I did see a small lowering with a bit of some inflow skud, but it was very weak. Hard to notice if not looking for it. No rotation, nothing really happening with it. It disappeared within 5 minutes.

Based on what I observed, I saw many of the same things I would have with radar tools. It was very refreshing to take what I have learned from radar and sat presentations and see it in action without any tools. Just observation.

Knowing both sides is critical to being a good spotter/chaser... I will continue to reduce over analysis and rely more on observation.

Pretty cool. I enjoyed that little storm more than any storm I have tracked on radar!

Stay tuned

I will be coming forth with some new thoughts. I will be taking this slow as I want to avoid further burnout or obsessiveness. In this time of reflection, I realized I had been burning the candle at both ends for nearly 5 years non-stop.

I will have something out this week contrasting what I would have normally done to watch as storm vs. observation used without following any other sources. Its really quite amazing what can be known just by careful observation and some basic weather knowledge.

It was refreshing...3 weeks without any weather analysis/research. Barely even watched weather segments on TV.

More to come...

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"Every new beginning comes from another beginning's end"


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