Current time: 7:00am CDT (Wednesday)
Location: Topeka, Kansas.
Today’s forecasted calls for much more severe weather than any day so far this trip. Thunderstorms are expected to develop along a warm front because of storms to the north weakening this morning whose out flow will provide cold air. When that air interacts with warm air from the south that will give a lot of lift for these storms. The warm air to the south (as indicated just by looking outside the dew covered windows of our hotel) is full of moisture and when this combines with the cold air from the out flow of those storms, the warm air will have nowhere else to go but up. Most of the ingredients that we look into for thunderstorm activity are there. CAPE values over central Nebraska will be very favorable for thunderstorms. Shear is there with values as high as 74 knots (for bulk wind shear), where CAPE values are in the 2000s (according to RAP and GFS model) and up to 4000 (according to NAM model) range. The hodograph is very loopy. Lifted index is about -7 in eastern Nebraska indicating very unstable air. The LCL heights were forecasted to be a little on the high side around 1000m but that is expected to lower to a more reasonable 500m with current forecasts.
(12z) sounding in North Platte is similar to Albany, NY’s back on July 21, 2003 during a tornado outbreak in PA and a Derecho event in the Hudson Valley
13:00z (8:00am CDT)- Our goal is to stay south of the warm front so we stay south of storms, which is why we are taking a lot of readings especially today. Observations will be critical because wind shifts and temperature changes will give us an idea of when we are approaching the boundary. The important difference between today and other chase days is the fact that to the north there will be a huge complex of thunderstorms that may even become a Derecho. Those won’t contain tornadoes and if they do, they will be too rain wrapped anyways, but the storms will be very severe with heavy rain and hail and they will be fast moving too. For this reason the storms we will chase will be any single cell storms that form south of this complex since those are what can become super cells and spawn tornadoes that will be potentially strong and more importantly for our purpose, potentially viewable.
13:17 (8:17am CDT)- We leave our Sleep Inn in Topeka Kansas heading west onto I-70.
13:20 (8:20am CDT) – Observation of 78/70 in Western Topeka. The higher dew points will increase the CAPE and lower LCL’s in the warm sector of the cold front.
13:30z (8:30am CDT) – Observation of 78/70 just south of Maple hill on I-70.
- Meso discussion states there is a 40% chance of a watch being issued.
13:45z (8:45am CDT) – Observation is 78/69 while driving on I-70 just south of St. George.
- York, NE observation: Winds sustained at18kts gusting to 22 knots from the North. The out flow boundary is south of this location.
14:00z (9:00am CDT) – Observation of 82F/68 near Junction City/ Fort Riley, Kansas
14:15z (9:15am CDT)- Observation of 81/69 near Chapman, Kansas
14:30z (9:30am CDT)- Observation of 81/69 near Solomon, Kansas
14:39z (9:39am CDT) – Current model run showing 2 cells around 21z in Nebraska with a north one around Lorde, NE and a south one around Windor, NE.
14:45z (9:45am CDT)- Severe Thunderstorm Watch for SD and NE border. We are not in this watch, the watch is not for our target storms since the storms causing the watch issuance are hail/rain events mostly.
- We turn north onto 81.
15:00z (10:00am CDT) – Observation of 82F/69F north of Minneapolis, Kansas.
15:30z (10:30am CDT) – Observation of 82F/70F southwest of Aurora, Kansas.
15:49z (10:49am CDT) – We enter Nebraska.
15:52z (10:52am CDT) – It is getting noticeably cloudier. The boundary is between Geneva and Hebron. We decide to stop in Hebron for gas and lunch and to monitor the boundary.
15:56z (10:56am CDT)– We see some towering cumulous while entering into Nebraska that may be capped which would lead to a collapse and that collapse could provide out flow to feed larger storms later in the day.
16:00z (11:00 am CDT) – Observation 82/70 in Hebron, NE.
16:02z (11:02 am CDT) – Arrive at Shell in Hebron for gas.
16:19z (11:19 am CDT) – We arrive at Subway in Hebron for lunch.
16:58z (11:58am CDT) – We leave subway and head back north on 80 to Geneva.
17:00z (12:00pm CDT) – Observation 82/69 south of Strang, NE.
- Portions of the watch area to the south and east are being monitored by the SPC for a tornado watch (we are in this area).
17:23z (12:23pm CDT) – We arrive at Geneva City Park in Geneva, NE.
18:10z (1:10pm CDT) – A tornado watch is issued for our area.
18:15z (1:15pm CDT) - An unconfirmed tornado in Rock County Nebraska.
18:15z (1:30pm CDT) – We leave Geneva, NE and head south to Aurora, NE (just east of Grand Island, NE so we can keep up with the boundary that is beginning to move north.
18:57z (1:57pm CDT) – we turn west onto I-80.
19:00z (2:00pm CDT) -
Special sounding for North Platte Topeka and Omaha
For North Platte…
Cape is 2500-3000
Mix layer is 2585
Cap of 700mb
Storm relative helicity 575
Observation 82/69 at.>>>>>>>>
19:14z (2:14pm CDT) – We head north on 14 for Aurora, KS.
19:15z (2:15pm CDT)- We feel very strong southerly winds (strong enough to push the car a bit). This will become the in flow for developing storms.
19:20z (2:20pm CDT) – We arrive in Streeter Park in Aurora, KS.
19:48z (2:48pm CDT) – Observation 84/71 in Aurora, KS.
20:00z (3:00pm CDT) – SPC issues a high risk for our area but the risk is for straight-line winds. Also a 60% chance for severe winds within 25 miles for much of Iowa because of developing derecho.
19:15z (3:15pm CDT) - We leave the park in Aurora, NE and continue north on 14to Central City, NE.
- Extensive roof damage in Stanton, NE from wind and hail.
- Cap has still not been broken but the more air parcels hit it, the weaker the cap will get and with this environment, it is likely the cap will break eventually.
20:35z (3:35pm CDT) – We arrive in Central City, NE.
20:48z (3:48pm CDT) Observation of 86/72 in Central City Park.
20:52z (3:52pm CDT) We are hoping for isolated cells south of the main system to our north. The models are promising. On radar, we can see that a cell is growing near Lexington that began to exist at about 20:00z(3:00pm CDT). The cell is 90 miles to our west.
20:57z (3:57pm CDT) New mesoscale discussion released. Warm front and cold front are coming close to each other.
21:00z (4:00pm CDT) The clouds are looking lower to the horizon and a towering cumulous are beginning to break a cap over us.
21:05z (4:05pm CDT) - It looks like the tops might be falling down on some clouds over us so that action could provide out flow, which would result in more lift for other storms nearby. All that is necessary is for one cloud to successfully break through the cap.
21:10z (4:10pm CDT) – A tornado warning is issued for a couplet over Burrell. This is 90 miles to our northeast.
21:15z (4:15pm CDT) – We leave Central City for St. Paul, NE, which will put us in a better position to drive to the Lexington cell if that continues to grow and to the tornado warned cell near Burrell if the couplet continues to remain promising.
- Echo tops on Lexington cell (now just south of Broken Bow) seems to be lowering on radar and the storm is beginning to spread out.
21:28z (4:28pm CDT) – As we turn left (to head west) on 92, we pass a DOW (Doppler on Wheels). Sign we are heading to the right place!
(4:30pm CDT)- VIL of 76 and radar indicated hail size of 3 inches on the tornado warned cell near Burrell. A tornado is now confirmed from that couplet just north of Ord, NE.
- Interesting note, the farm animals always group close to each other when a storm is nearby.
21:35z (4:35pm CDT) – The storm that we were watching to our west is by Berwyn and it is dissipating. There is a storm behind it beginning to form from the out flow of the dissipating storm so that is something to keep an eye on.
21:38z (4:38pm CDT) – Dust is being picked up by the in flow winds as we continue to get whipped around by the in flow winds as we approach the storm.
21:40z (4:40pm CDT) – Official observation from Ord, NE has winds sustained at 30kts gusting to 40 kts.
21:48z (4:48pm CDT) – We are making a right turn onto 281 heading north until we get too close to the tornado warned storm.
21:50z (4:50pm CDT) – We pass St. Paul.
21:53z (4:53pm CDT) – We see a lowering straight-ahead of our current location just north of St. Paul in our north direction. Might just be in flow clouds.
22:02z (5:02pm CDT) – We stop to observe the storm on 281 just southwest of Wolbach and if we cannot get a view we will consider going half a mile further north.
22:05z (5:05 pm CDT) – A tornado is reported crossing 281 for miles north of where we are at this time (we found this out a half hour later), but was likely blocked from our viewing from either the hill ahead, or rain, or both.
22:12z (5:12pm CDT) – We head back south to avoid the gust front has the RFD movies closer to us.
22:20z (5:20pm CDT) – the original couplet is now covered in rain but there is now an indication of some rotation in the RFD both on radar and in sight.
22:25z (5:25pm CDT) – We turn east onto 92.
22:30z (5:30pm CDT) – the latest radar indicates the couplet is 4 miles south of Cedar Rapids. We still have catching up to do with the storm moving generally east at 50mph-55mph.
22:44z (5:44pm CDT) – We are still trying to gain on the couplet.
23:00z (6:00pm CDT) – We decide to bail south next chance because we still only see some rotation and no funnel cloud. We will chase a cell farther to our west that has a severe thunderstorm warning.
23:10z (6:10pm CDT) – We bail south on 81.
23:15z (6:15pm CDT) – We see rotation on the original tornado warned cell and we see some dust rotating underneath it! It has not connected.
- We pass Stromsburg.
23:24z (6:24pm CDT) – We continue to head south while observing the tornado warned cell behind us while we move to the next cell.
23:30z (6:30pm CDT) – A tornado warning for the cell behind us is dropped. We are heading to a single cell storm near North Platte but that is now beginning to become a line.
23:45z (6:45pm CDT) - There is another storm northwest of Gutenberg. Rotation has been spotted by some tweeters and by radar so that is our next stop. Unfortunately we are beginning to lose daylight.
- We turn west onto I – 80.
0:00z (7pm CDT) – The SPC mesoanalysis shows a new cell north of Lexington weakening as it moves into an area that is capped. LCL height is 600m and dew point are lower to the west than east.
0:08z (7:08pm CDT) – The rotation on the cell near Lexington is weakening and the storm itself is also showing signs of weakening.
0:11z (7:11pm CDT) – The SPC meso-analysis says that the base is going to become elevated and the VIL is dropping so w are going to stop in Grand Island for some gas and wait and see.
0:15z (approx. 7:15pm CDT) We arrive in Grand Island. The temperature at the gas station in Grand Island off of I-80 is only in the 60s.
0:30z (7:30pm CDT) – We leave the gas station in Grand Island (fortunately without any sign of our friend who was there the first time we swung by) and head south on 281.
0:36z (7:36pm CDT) – We pass the out flow boundary and temperatures very quickly increase significantly as we pass that leading out flow boundary. There is a second and stronger out flow boundary from that same storm near Lexington that is weakening. We are hoping that since the boundary is approaching warm air, it may provide enough lift to initiate more storms. By 0:55z (7:55pm CDT), the temperature acc. to the car temperature rose to 85F!. We are trying to outrun an out flow boundary from the storm that was near Lexington due to high winds associated with it. Now that the boundary is heading into warmer air, it may initiate more storms.
0:45z (7:45pm CDT) - We enter Hastings, Nebraska.
0:51z (7:51pm CDT) - The out flow boundary is looking interesting and it is the last chance for more convergence storm initiation. Cumulous clouds are appearing to bubble up on top of the out flow boundary. We are still under a severe thunderstorm warning because of the winds expected from the out flow boundary.
- We head west onto 6.
1:06z (8:06pm CDT) 73 mph winds were reported in Hastings due to the gust front from the out flow boundary.
- We turn south onto 14.
1:07z (8:07pm CDT) - The shelf cloud still looks very impressive. This boundary is the cause for us to be under a rare wind related severe thunderstorm warning.
Approx 1:50z (8:50pm CDT)- We ate dinner at a Subway in Superior, NE and are now seeing lightening to our east from a storm near Beatrice, KS. The storm is about 60 miles away and is tornado warned.
Approx 2:40z (9:40pm CDT) – We leave Superior to head east on Highway 8 to our hotel for the night.
02:48z (9:48pm CDT) Ryann almost runs over a second raccoon, the first of 3 more animals that night.
03:07z (10:07pm CDT) We pass Chester, NE (on the Kansas/Nebraska border) and head south on 81.
We arrive at our hotel in Salina, Kansas late that night.
After a relaxing yesterday, we had a very full day ahead of us today. Today was filled with a lot of movement all day long instead of our usual sitting and waiting for storms to fire up since we needed to make sure we were just south of the boundary and not to the north. There were very strong storms already present from the start of the day to our north, but those were not our target since they were a large complex of storms. We knew today would be a dangerous day for severe weather, but if individual cells did not fire up south of the main complex, than any tornadoes that form would not be visible since they would be rain wrapped and/or very dangerous to get to. Those individual cells would fire up along the boundary and in order to locate the boundary we relied on our own observations and the observations we heard on the radio in surrounding areas. I think one of the most memborable things from today was the sudden temperature drop outside of Grand Island, Nebraska when we passed through the outflow boundary. Temperatures went from the 60s to the 80s within just a minute or 2 on the car thermometer. It went from chilly outside to warm and humid very quickly! Another thing I will take from today was how close we were to seeing the tornado just north of St. Paul. We were only 5 miles away from the touch down, but the hill was blocking the view of the tornado crossing 287 and it’s possible the tornado was also rain wrapped so we were unfortunately not able to see it. It was also very cool to be under a severe thunderstorm warning for an area that was not going to be impacted by the actual thunderstorm, but instead impacted by the dangerously strong outflow winds from the storm! That’s a thunderstorm warning I never saw before and being a part of observing that was really amazing. Even though we did not see a tornado, today was still an exciting chase day. Everyone knew that today would be a dangerous day for severe weather so being in that atmosphere was a really surreal experience and an experience I won’t forget.