Sunday, June 10, 2007

June 10 TWISTEX Update

Status: Awaiting Deployment
Location: Terril, IA

Just a quick update as I have little time to spare currently. Arrived back at home on Friday evening, been spending time here now as we have had a couple days off. Tomorrow looks good for severe weather, with isolated tornadoes possible, however the best threat is into western North Dakota. This means a very long drive to reach a target area from Ames, over 10 hours, plus the road networks aren't known to be the best. This means that we will not be deploying for a target tomorrow in ND...

We may be deploying for Tuesday/Wednesday in the northern plains, decision on when/where the target has not been made. Tomorrows' update will have more details on the possible deployment for Tuesday, along with subsequent days.

Friday, June 8, 2007

June 8 TWISTEX Update

Status: On-The-Road
Location: Dubuque, IA ~ Ames, IA ~ Terril, IA

Severe weather risks are in the forecast through next Wednesday for the SPC, however the next couple of days risk aren't the most conducive for tornadoes. Sunday looks to have potential across central NE especially with the latest model runs, good shear/instability combination that may support some tornadic storms. Monday through Wednesday next week has our next trough coming onto the plains and would also likely be a good system for severe weather. This system is different from the last in that it is not as strong dynamically with the low pressure system, but is much slower and compared to how the last system turned out it is likely better. The risk translates across from the Dakotas/Nebraska on Monday to Dakotas/NE/KS and western MN/IA on Tuesday and finally a threat across much of IA/MN into MO on Wednesday. That compared to a western Dakotas threat one day, to Wisconsin threat the next! Overall feel that although we might get a tornadic supercell in the high plains on Saturday, the drive day down there today just doesn't seem warranted.

Indeed after meeting with the entire crew it just doesn't look good enough on Saturday for us to drive down to the high plains. Instead it looks as if we will hold off on operations until next Monday with the trough moving in. Sunday is still a possibility for deployment, but not likely. So as noted above in 'Location' we are headed back to Ames, IA and then I'll be back home by this evening. Drive totals once again noted below:

Total Miles: 245 Miles (1,664.33 Miles Total)
Total Road Time: 6 Hours, 15 Minutes

Thursday, June 7, 2007

June 7 TWISTEX Chase

Status: On-The-Road
Location: Sioux Falls, SD ~ Dubuque, IA

Be sure to read back on previous post, as Chase Recap of the June 6 Chase has been posted.

Chase Recap: Began in Sioux Falls, SD; ended in Dubuque, IA after being all the way to northeast Wisconsin today. Storms were able to rotate fairly well, organization was lacking some, but the worst thing of all was the speed of the storms. Storm motions were 50-70 mph for the most part, moving northeast and making them impossible to keep up with. We were in position on one tornadic storm in southwest MN, but the storm quickly went outflow dominant. Also watched the beginning of the storm of the day, that ended up traveling through Wisconsin and putting down several tornadoes. We then got on a storm that traveled through central Wisconsin, ended up with around 5 wind/hail reports from it. Also looked very good at times, but in the end, way to fast to keep up with.
Not a great day, but we were in position and did the best we could. Decision time now for TWISTEX team on where to head next. Possible weekend chasing in the high plains, or return to bases for a couple days break?

Total Miles: 644.33 Miles (1,419.33 Total)
Total Drive/Chase Time: 13 Hours, 51 Minutes

Wednesday, June 6, 2007

June 6 TWISTEX Chase

Status: On-The-Road
Location: Ames, IA ~ Sioux Falls, SD

ISU Crew getting prepared to take off early this morning, yes it is now 4:45 am! Heading to central SD for the day, Moderate risk by the SPC has been issued for a large area of the northern plains. Not to much time to update, just check back throughout the day as updates will likely come in as we have time.

Chase Recap:

As stated, started off the day in Ames leaving at 5:30 am on our way to the target of Murdo, SD. Arrived in Murdo where we met up with Tim Samaras and the rest of our crew. We were quickly joined there by several other chase groups, including the DOW/ROTATE crew, Texas Tech, Twister Sisters, Silver Lining Tours and several others. Waited around there for quite a while until storm in Shannon/Bennett county went up and got going. Decided to head after that cell as it was tornado warned and tornado confirmed, but several problems with equipment held us up for a while. Did end up getting on this cell as it was going HP (high precipitation) to the southwest of Kadoka, SD. Very beautiful cell that was well contrasted really, good lowerings and showed good rotation on the leading edge of it for a while. Nice brief funnel before we had to take off to avoid getting overtook by the precip; which we played around with for nearly an hour and a half. Quite a few gustnadoes with the leading edge as well as we let it overtake us a couple of times, reading ~50 kt gusts on the mesonets. So playing with this line as many others did, it did produce one good tornado for ~30 minutes in its' beginning however as several other storms merged in with the storm it went mainly outflow and created a good wind/gustnado event.

Highlights for the day will include the nice HP cell southwest of Kadoka, SD; Several gustnadoes with the leading gust front; pea sized hail near Vivian, SD; and the very nice chaser convergence in Murdo, SD.

Spending the night in Sioux Falls, in which we should be arriving there by midnight. Looks like a chase target of eastern Iowa for tomorrow. Next update likely tomorrow sometime...

Total Miles: 775 Miles
Total Road/Chase Time: 19 Hours

Tuesday, June 5, 2007

TWISTEX Update #2 (June 5)

Status: Final Preparation for Deployment
Location: Terril, IA ~ Ames, IA

Final preparations have been done to the mesonet vehicles, tested all equipment and they are gassed up ready for the trip to SD tomorrow. ISU crew is meeting in the morning and departing at 5:30 am on the road to central SD. We will be there plenty early, but this is being done in order for us to go over everything with Tim and the rest of the crew. Expect initiation to hopefully occur by 7 PM tomorrow, the capping is quite a concern at the moment for all chasers. Despite this, there is a lot of chasers making quite a journey to the targets in SD/NE. With such an early departure it is time to head to bed for the night... I'll hopefully get an update on here for June 6th before I take off.

Thanks to Eric Kropf for the room tonight... Sleep time!

TWISTEX Update (June 5)

Status: Final Preparations for Wednesday Deployment
Location: Terril, IA

Models continue to show significant parameters for a severe weather outbreak on Wednesday (Tomorrow) and thus TWISTEX is a go for activities in the SD/NE area. Timing is an issue with the speed of the low pressure system along with its' location in SD; the timing of a 500mb wave coinciding with the vorticity max is also a concern. The vort max will be a likely initiation for storms, if they do not get going on their own. Currently the capping is the biggest concern, with temperatures at 850mb and 700mb not being very favorable for storm development. Shear is well beyond sufficient, with instability the same; thus the stage is set for a potentially significant severe weather episode. Currently the SPC has areas of SD/NE/MN/IA and even an extreme portion of northcentral KS in a Moderate Risk. New outlook expected within an hour may change slightly, but nothing dramatic is expected. Initiation seems possible by late afternoon along the dryline/cold front, especially further north near the low pressure system and triple point.

TWISTEX crew members will all be on the road today, ISU crew is meeting in Ames, IA tonight. Tim and crew will also be getting into NE to spend the night setup closer for tomorrow. Minnesota (WindLogics) crew will likely depart early tomorrow as well as the ISU crew to get to target by early afternoon Wednesday. Current thinking is the drive into southcentral SD for Wednesday target.

Another update on status is likely tonight...

Monday, June 4, 2007

TWISTEX Update (June 4)

Status: Preparing for Departure Tomorrow, Deployment Wednesday
Location: Terril, IA

SPC has issued a MODERATE risk for Day 3 already, with the highest probabilities that are allowed. This risk area includes portions of SD/NE/MN/IA, with the mentioning of strong supercells. Not only will the large hail, damaging wind threat be significant, but the tornado threat is also very high per the latest model runs. SPC also indicates this with their text, indicating the potential for strong, long track tornadoes.
All models are in good agreement for the most part, all of them agreeing that the warm sector in which the moderate risk has been issued has significant severe potential. Instability is near extreme values, although slightly overdone by high forecasted dewpoints. Shear is also outstanding, wind fields are impressive with strong southwest flow at mid levels, southerly flow at lower levels and then great upper level support as well. All of this is leading to an event that may likely be one of the better ones of the year, other chasers are calling the setup, "Insane".

TWISTEX crew is preparing for deployment on Wednesday, although many of the crew members will already be on the move tomorrow afternoon. ISU students planning on Tuesday night meeting, to prepare for departure on Wednesday morning. Samaras & National Geographic members may leave tomorrow as well to get an early start on the trek to NE/SD. No target has been specified, beings a lot is still changing with timing, expecting a target area in southern SD between Mission, SD and Lake Andes, SD. Next Update Likely Tomorrow Morning/Early Afternoon...

Sunday, June 3, 2007

June 3 TWISTEX Update

Status: Preparing for Mid-week Deployment
Location: Terril, IA

Both the NAM/WRF as well as the GFS are within range of the next system to effect the plains states mid-week this week. A strong wave expected to come onto the west coast by late Monday/early Tuesday and work across the rockies and into the plains by Wednesday evening. This wave will be responsible for the flow returning to the southwest at mid levels, also in the formation of a potentially significant low pressure system. This low in conjunction with the mid-level wave is going to aid in bringing up good moisture northward, near 70 dewpoints into NE/IA. Low pressure currently forecasted along the SD/NE border, with warm front extending southeastward and dryline expected to the south from SD through KS and possibly into the southern plains. TWISTEX is likely for deployment on Wednesday for areas of NE/KS, with continued chasing through the week. This trip is potentially the first long trip TWISTEX is going to be able to take this year, with previous trips only including 2/3 days of chasing. More details on this trip likely by tomorrow and especially Tuesday as I prepare to travel to Ames and get on the road in the TWISTEX vehicles.

Long range outlook for the project also continues to look promising with no major ridges being shown. Continued active June is a good possibility at this point and thus expect many updates concerning TWISTEX and the next possible deployment.

Saturday, June 2, 2007

Severe Weather in Extended... Iowa T'storms...

TWISTEX Update (June 2)
Location: Terril, Iowa

Despite recent severe weather with some tornadic thunderstorms over the plains states, TWISTEX has remained stagnant with the northwest flow. Models are finally converging on a very nice solution for next week, with southwest flow returning. The exact timing of the large trough that will make its' way over the plains is still up in the air somewhat. Previous indications from Tim Samaras were we could possibly deploy on Tuesday, even Monday, but latest forecast doesn't put southwesterly flow onto the plains until Wednesday. Tonights' model runs show an outstanding setup for Wednesday over central Nebraska, with continued threats likely for the remainder of next week. Likely deployment by next Wednesday, details coming in later updates...

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Widespread thunderstorms continue across the state today, with only one severe weather report thankfully (large hail). Tomorrow is likely to continue this trend with scattered showers/thunderstorms across the state. When the sun does come out between the breaks in the clouds it is expected to warm up quickly, highs in the 70s throughout the state. Expect the rain to exit most of the state by Sunday night, lingering showers possible in eastern Iowa; Lows in the mid 50s to upper 50s. To start out the work week, expect highs in the lower to upper 70s, scattered showers/thunderstorms once again are in the forecast.

Going back to the tornadoes on Friday, damage surveys have been completed by the NWS, links to each of the reports below.

Louisa & Muscatine county Damage Survey
Jackson county Damage Survey

Friday, June 1, 2007

June 1 Severe/Tornadic Thunderstorms

Tornado Watch #321 has been issued for portions of eastern Iowa and will be in effect until 7 PM this evening. There have already been several reports of a tornado traveling through Louisa, Muscatine and now Cedar counties in Iowa. The town of Muscatine has been reportedly been hit by this tornado and damage has been done as a couple of the reports have indicating debris with the tornado. This storm has done damage and may continue to do so as it moves northeast, those living in eastern Iowa should pay close attention for the remainder of the afternoon as these storms move through.

Update: New Tornado Warning issued for Rock Island county in Illinois, this cell has just went tornadic and is an indication that the cells this afternoon mean business.

2:00 PM Update: Tornado warning for Jackson county in extreme eastern Iowa, otherwise Severe Thunderstorm Warnings for Scott & Clinton counties as well. There is a second line of thunderstorms west of this line, however at this time they do not look like they will become severe. Thus, expect the severe threat over the state to be diminishing after 3 PM.

The area in and near Muscatine, IA has been reportedly incurred significant damage; houses and businesses have been destroyed with several injuries. Path of damage goes from Fruitland, IA to Muscatine, IA as of latest reports from law enforcement. Other damage reports have been received from the Grandview, IA town where more significant damage has occurred, the town has been cordoned off by police due to the damage.

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Review & NWS Surveys': The NWS in Davenport has already surveyed the tornado that tracked through Grandview, Fruitland and Muscatine areas. The tornado was given a starting point 1 mile south of Grandview, tracking through the town and moving on to go through parts of Fruitland and Muscatine. A total of 16 miles of tornado damage as it moved north-northeast and lasted for over 20 minutes. The tornado receives a EF3 rating (winds ~143 mph) for the damage that was done in Grandview, EF2 (winds ~125 to ~135) damage was done in both Fruitland and Muscatine. More detailed information on the damage, as well as some photos are on the NWS Survey Page.