Thursday, May 2, 2013

Historic SWIFT 2011_Week1

Going through the archives from 2011 and our SWIFT team sharing their experiences.

SWIFT Day 1, 13MAY11

Swift Blog Day 1

The mission of the 2011 Severe Weather In-Field Training (SWIFT) activity is to (a) engage midshipmen in forecasting, observing, and verifying severe convective storms and (b) develop them professionally with tours and briefings at NOAA and AFWA operational and research facilities. This year we are being funded by USNA STEM (Science, Technology, Engineering and Math), and will possibly be visiting local military schools in the area, and briefing them on the trip and USNA.

It’s Friday the 13th, but the SWIFT van departed the Naval Academy this morning seemingly without bad luck. In fact, we encountered a line of thunderstorms (squall line) as we drove down I-81 hopefully a sign of exciting things to come! We clearly saw an anvil cloud on a  thunderstorm 10 miles away. Our weather radio issued several thunderstorm warnings and more thunderstorm watches. We did not experience hail, which the warnings called for, but saw lightning and heavy precipitation.

We tracked other severe thunderstorms with the help of the GR Level 3. The GRLevel3 software allows us to not only watch a real-time radar picture, but detect storm relative motion, storm path, and probabilities of large and severe hail. It updates every 4.5 minutes with new data from the NOAA Direct Feed.

Once we arrive in the great plains and go into chase mode, we will use the GRLevel3 software and many other technologies to track storms and enable you to see what we see on the ground. We have a video camera mounted to our dashboard that will stream live video to Our Twitter account #SWIFTUSNA (URL:!/swiftusna) and our Facebook page “SWIFT USNA Oceanography” (URL: will post live updates. You can track our location live via Instamapper which is based on cell phone signals at In case this system fails, we have a HAM radio backup at

We have 6 laptops with Wi-Fi in the van, as well as a presentation monitor perched in the front seat. The presentation monitor allows us to see the GR Level 3 radar in action, observe  mesoscale conditions and the synoptic situation as we drive, and view satellite, surface, and charts of pressure, vorticity, helicity, moisture, CAPE, etc. charts. Our projector enables us to give meteorological briefs before commencing the chase for the day. To power all of our equipment, we have 4 auxiliary battery packs standing by.

The Kestrel 3000 handheld anemometer allows us to measure wind speed, direction, temperature, and relative humidity. We will use the Kestrel to collect in-situ surface data in storm mode. We will especially focus on measurements of dewpoint temperature, because dewpoint is the primary driver of atmospheric buoyancy. When we do observe severe weather, we will immediately report it to the National Weather Service via our participation in the national Spotter Network.

As a reminder of how powerful tornadoes can be, we observed the destruction left in the wake of an EF-3 tornado in Glade Spring, VA, that occurred during the April 28 tornado outbreak. This area is mountainous, but was still affected, disproving the superstition that tornadoes cannot pass over mountains.

SWIFT Day 2, 14MAY11

     After a night’s stay at the Quality Inn just outside of Fort Campbell, Kentucky, we made our way onto base. We were welcomed by Capt. Jonathan Wilson, USAF of the 18th Operation Weather Squadron. His group, which is attached to the 101st Airborne Division, provides operational support for the 60,000 Army soldiers located on Fort Campbell. One may ask “why is an Air Force officer providing weather information to the Army”? The answer is found in the National Security Act of 1947, which established the Air Force as responsible for providing weather reports to Army commanders.
    Capt. Wilson, along with several sergeants, showed us all of the equipment used for weather on the Fort Campbell airfield and in the forward deployed theatre. Along with commercial radar, he showed us the FMQ-19, which gives a once a minute surface observations of the airfield. It is similar to the ASOS found at every airport in the US. After giving us a tour of the weather office at Fort Campbell, we ventured into the cold and rainy weather to see the types of equipment used in Iraq and Afghanistan. The sergeants demonstrated the capabilities of the TMOS or TMQ 53. It is essentially a weather station that can be set up in 20 minutes and start giving observations to the troops. The $110,000 tri-pod system can tell the Air Force weather team temperature, dew point temperature, pressure, visibility, wind direction and speed, number and proximity of lightning strikes, and the types of cloud cover. The TMOS can be operated by a handheld computer or connected to a laptop inside a humvee weather system called an IMET. Inside the IMET, the tactical meteorologist can speak to pilots and connect to the internet anywhere in the world to look at models and observations via the BGAN internet system. It is a highly tactical and mobile weather station with self sustainable power.
After our outdoor tour of the TMOS and IMET system, we went inside the tactical readiness facility of the 18th Weather Squadron. Here, we talked about the different operations that an Air Force weather team attached to the Army might execute. One particular Air Force sergeant, who was Air Assault and jump qualified, described that they are required to be first response capable. This means that a weatherman could be launched out of an airplane with airborne units behind enemy lines. They also spoke on the sustained efforts that are more common in present-day Iraq and Afghanistan, giving forecasts and reports to pilots and unit commanders who are planning operations.
    After the tour, we went back to the hotel to get our equipment to continue to the drive west to the National Weather Service in Norman, Oklahoma.
                Today, the NAM model for Tuesday 12Z was published. Our first chase day is Tuesday, so we did tentative forecasts of mesoscale conditions for Sunday, Monday, and Tuesday using the NAM model. Unfortunately, Tuesday’s conditions are terrible for tornado chasing. Over this weekend and into Monday, a pronounced upper level ridge is situated over South-Central Canada. The first two isobars of high pressure are closed, indicating that this high pressure system is quite slow-moving. Additionally, dewpoints are in the 30’s Fahrenheit. The large dew point depressions across the Great Plains over the weekend, Monday, and Tuesday show that the air is very dry, conditions unfavorable for convection. The dryline in Eastern New Mexico is weak and very spread out. Winds are forecast to be northeasterly over the weekend and on Monday, bringing dry continental air into the area. Accordingly, CAPE is negligible over the Great Plains for this time frame. Therefore, despite the presence of wind shear from central Texas, Oklahoma, and Kansas, eastward, the prognosis for tornadoes over the Great Plains for Tuesday is poor. The only exception is a tongue of moisture- dewpoints in the 50’s and 60’s- brought into South Texas by a southeasterly wind off the Gulf of Mexico, starting on Tuesday. Low values of CAPE exist along this moisture intrusion into South-Central Texas.  On Tuesday, the isobars around the high pressure system unclose as the system plods eastward.
                On Wednesday, GFS models indicated that the high pressure center has shifted to the east. A dramatic trough is centered on New Mexico and brings high speed upper level winds to the Texas and Oklahoma Panhandles. This trough features some divergence, a good sign for convection. According to the GFS model, dewpoints have increased over Oklahoma and Texas into the 60’s by Wednesday. A tongue of cape around 1750 j/kg extends along Central Texas, along the Texas Panhandle where it borders Oklahoma. However, we noticed that moisture estimates for all timeframes are much greater in the GFS model than in the NAM model. The NAM models have a greater resolution, with data points every 4 km, rather than much less refined resolution on the GFS models. The pessimistic moisture forecast in the NAM model is much less favorable for tornado formation. As we get closer to Monday, Tuesday, and Wednesday, the models will become more accurate and we will have a clearer picture of where, if anywhere, the SWIFT team can find their first tornado this week!

SWIFT Day 3, 15MAY11

       After arriving in Oklahoma, we observed Dr. Andrew Taylor of the National Weather Service launching the 00Z balloon at the NWS office in Norman, OK. This NWS office releases local forecasts for Western Oklahoma and several counties in Texas. Meteorologists around the world release balloons with attached radionsondes at 00Z and 12Z in order to obtain real-time data about the atmosphere for their location. Radiosondes contain a battery and instrumentation for recording and relaying back information about temperature, relative humidity, altitude, and pressure. A GPS onboard the radiosonde reports its position; by calculating distance the balloon is blown over time, the GPS also enables the meteorologist to determine wind speed and direction.
       This evening, we met with several alumni of the United States Naval Academy, who are involved in the USNA Alumni Association, Oklahoma Chapter. Among them were CDR Novak, USN (ret), class of ’91, and Col. Bonifay, USNA (ret), class of ’60. We prepared a brief for them to show them how advanced the Oceanography Major has become, and what unique internship and research opportunities we have. We had the opportunity to converse with these graduates over dinner at the Legends Restaurant- a fitting name.  This event was organized by Dr. John Bennett, USNA ’61.

SWIFT Day 4, 16MAY11

Today was a busy day for the SWIFT team. We made the most of the high concentration of meteorologists (1% of all residents!) in Norman, OK. In the morning, Director of Operations David Imy, of the Storm Prediction Center, gave us a tour of the SPC and explained how they create their severe weather products, which include probabilities of severe thunderstorms, severe hail, and tornadoes, mesoscale discussions, and convective outlooks out to Day 8. The SPC still analyzes 925 mb, 850 mb, 700 mb, 500 mb, and 250 mb charts by hand, as well as uses state-of-the-art models, including a European model and the more common NAM and RUC models. Screens display infrared, and water vapor satellite images, probability forecasts, and radar feeds of interesting weather. 4-5 forecasters are in the office at any given time; the SPC office is staffed 24/7. The SPC also forecasts for fire weather- fire weather forecasts are important in order to know the direction and intensity of wind, which could intensify a fire, and the chance of rainfall, which could mitigate a fire. The SPC is one of nine National Centers for Environmental Prediction (NCEP), located across the country. Mr. Imy also told us about the process of information dissemination- distributing their probability charts and outlooks to local agencies, who can then issue warnings for their area.
                The Storm Prediction Center shares a building on the campus of the University of Oklahoma with the National Severe Storms Laboratory, School of Meteorology at the University of Oklahoma, Oklahoma Climatological Center, and several other research groups. Daphne Thompson gave us a tour of the building. First, we went to the 6th deck of this building, an Observation Deck that allows meteorologists in the building to view developing weather from all 360 degrees. Students can conduct experiments on the roof using “weather pods”, a garden on the roof, or devising their own instrumentation. The 5th floor contains classrooms for undergraduate and graduate students. OU has the nation’s largest undergraduate meteorology program, with approximately 300 students enrolled. On the 4th deck is a library, which includes meteorological texts and theses and dissertations from past graduate and Ph.d.  students, including our very own Dr. Barrett. The 3rd deck houses servers and miles of cables.  These computers allow for the computation of models and processing of data from the MOklahoma. There are MESONET sensors in every county. Daphne then showed us the watchfloor of the National Weather Service Office for Norman, OK. This office provides local weather information and warnings to western Oklahoma and several counties in Texas.
Next, Celia Jones of University of Oklahoma’s School of Meteorology spoke to us about its graduate program. She gave us an overview of admissions requirements, curriculum, and a day in the life of a master’s student.  Celia attested to the fact that military personnel attend the University of Oklahoma’s graduate program in meteorology while still serving.
In the afternoon, we toured the National Severe Storm Laboratories' research-oriented Doppler radar, and a SPY radar in experimental use. The Doppler radar spins at 5 revolutions per minute continuously. It utilizes a parabolic receiver, which means that the pulse leaves and returns to the same antenna. This leads to a refresh rate approximately every 6 minutes. The specific model used all over the country is the WSR-88D, meaning Weather Service Radar made in 1988. The SPY radar is a civilian version of the military’s SPY-1D radar used in its Aegis Air Defense systems. It is a phased array radar, meaning over 4,000 transmitters and receivers send out and collect information, instead of just the one transmitter and receiver in the WSR-88D. The SPY radar refreshes approximately every minute, allowing meteorologists to detect severe weather faster and issue tornado warnings further ahead of time. The SPY radar could also be useful in aviation meteorology, because it has the ability to provide a 3-d picture of winds with height, instead of the 2-d picture of wind fields given by the WSR-88D. It is likely that the weather field will shift to the more accurate, faster SPY radar as it proves itself operationally.
After the tour, it was time for our daily SWIFT weather brief. As, we looked at the NAM model we saw that we were in a dry spell. In the northeast and northwest there are low pressure systems and a weak high pressure system located over the central United States. This formation causes dry, sunny weather in the central U.S. which is unfavorable for storm chasing. As we look at the weather models for later in the week; the conditions are more promising. The low pressure system over the northwest will begin to move over the Midwest beginning on Wednesday thus causing severe weather for Thursday and Friday. The van as a whole is getting their hopes up for seeing a tornado soon.

SWIFT Day 5, 17MAY11

Today was an uneventful day for the SWIFT team. In our weather brief this morning, we determined that moisture levels increased from over the weekend, and are projected to further elevate later in the week. Higher moisture levels are more favorable to convection and storm formation. The high pressure ridge moved into eastern Oklahoma, and a trough is poised to bring strong upper level winds and divergence aloft into the southern Great Plains area later this week. Divergence and fast winds aloft are associated with severe weather. Vertical wind shear is very favorable for supercell formation across the southern Great Plains. A narrow band of moderate levels of CAPE bisected the Texas panhandle today; instability all over the Great Plains is forecast to increase later in the week as moisture returns. We are hoping for severe weather later this week.

Knowing that any severe development today was highly unlikely, we elected to do a “dry run” of chase mode today. We drove to an area near Clarendon, Texas, within the tongue of CAPE, east of the dryline, and observed a few cumulus clouds developing between 1 and 6 PM. Temperature and dewpoint data on the GRLevel3 demonstrated that the dryline moved east as the day progressed. However, there was not pronounced vertical development beyond a few altocumulus clouds. In chasing lingo, we call this a “clear air bust”. Hopefully we see severe weather later in the week and have something exciting to report when mesoscale conditions are more favorable for supercell and tornado formation.

SWIFT Day 6, 18MAY11

We began our day at Perryton High School in Perryton, Texas. We set up our projector and laptop in the library and conducted our weather brief for students and faculty to observe. We proceeded to brief students on the Naval Academy, the STEM and SWIFT programs, and our Oceanography Department. After the presentation, we fielded questions. At about 1030 we began our first promising chase of the year.
The RUC model suggested possible severe thunderstorms and tornadoes around 1700. 0-3km helicity, CAPE, bulk shear, and some moisture were all present and were maximized near a triple point in west-central Oklahoma. Southwesterly winds were converging with southeasterly winds and a diffuse dry line bowed through Oklahoma and central Texas. Our destination point was Watonga and alternate positions were around the Oklahoma cities of Seiling, and Canton. From this area we observed cumulus cloud formation and waited for more vertical development. However, the base of these cumulus clouds evaporated before developing into any significant weather. At approximately 1907 the weather team called off the chase with less than ideal skies and no signal for tornado warnings on radar or radio. The SWIFT team retreated to Enid, Oklahoma for the evening.

SWIFT Day 7, 19MAY11

Thursday, May 19, 2011
We began our morning weather brief in Borger, Texas. At the brief, we discussed the potential for seeing a tornado. We came to the conclusion that today would have the highest probability for seeing a tornado thus far. When looking at the computer models, we saw that there was a change in wind direction from south to east winds in west Kansas, CAPE would be around 2500, the 0-6 km shear was 50 knots, and there was level low shear and helicity. These parameters proved favorable for tornado formation. We decided to position ourselves east of the dry line near Pratt, Kansas since this was a fast moving storm (50 mph) that would head in the northeast direction.  As we heading into the afternoon hours, we prepared for chase mode and continued to watch the surface observations and analysis models.
Initially when we initiated chase mode, around 1400 (2:00 pm) we saw storms develop, on radar, west of Wichita, KS.  These storms were not significant because they developed and matured quickly, then moved NE into an area with low CAPE values and higher CIN values.  We did not bother to chase these storms because they were short lived storms.  However, these storms did indicate that the atmosphere was ready for convective initiation to start.  We waited for about 30 minutes then convective initiation began SW of Great Bend, KS at around 1430.  This was the storm that was in an area of high CAPE and low CIN.  So we knew this storm was going to last for a long time.  Also, this storm was in an area with high 0-1 km and 0-6 km helicity, so this storm had a high probability of being a super cell and possibly producing a tornado.
We decided to chase this storm.  In order to obtain the best vantage point of a possible tornado, we travelled on a North-South road east of the storm.  After the storm travelled past Great Bend, KS, it started to rotate and became a super cell.  We tried to stay just ahead of the updraft region of the super cell.  There was heavy rain ahead of the updraft region of the super cell and a lot of scud below the base.  Around this time, a storm formed south of this super cell and started to rain into the updraft of the super cell.
The super cell continued North East at 20 kts and we continued to follow it.  When the super cell crossed over I-70, a wall cloud formed at the base of the super cell.  The storm was showing significant rotation and inflow.  When we crossed under I-70 and stopped just north of I-70, the base cloud was green, therefore, indicating hail within the cloud.  The winds were very strong and going into the super cell.  Then a heavy down pour fell on us.  We continued to follow the storm by moving north.  We were driving through the heavy rain, around Wilson Lake in Kansas.  At this point a tornado warning was issued for our area because a tornado was reported to be on the ground and moving NE near the location where we were just at.  However, we did not see any sort of tornado within that area.
When we arrived at the other side of Wilson Lake, we stopped on the side of the road to see what is happening with the super cell.  The updraft region went right over top of us.  The rotation of the clouds was very pronounced and fast.  It appeared that a tornado was going to develop right over top of us.  However, it did not develop.  When that passed over us, we continued to follow the region of rotation in hope of seeing a tornado develop.
 When we followed the super cell we travelled through Sylvan Grove, KS.  When we travelled through town, the tornado sirens were blaring.  This meant that a tornado was imminent.  We travelled just north of the town; we stopped on the side of the road.  The rotation of the wall cloud was greater than what we saw before.  It looked as if a tornado was going to develop.  However, it failed to occur.
We continued to play leap frog with the super cell.  There were a few reports of tornadoes that formed in this super cell.  However, we did not see any of them.  Either they were false reports, short lived tornadoes, or rain wrapped tornadoes.  As we continue to follow the super cell there was strong rotation indicated by radar and the National Weather Service was issuing tornado watches and warnings.  Eventually, other storms developed around the super cell and the super cell turned into a Mesoscale Convective System (MCS).  This diminished our chances to very low of seeing a tornado.  However, there was another storm forming SW of the MCS, around 1900.  We then decided to chase that for one last chance of seeing a tornado.  This system was isolated and had marginal air for a convective system.  This storm did not amount to anything significant, tornado wise, but it did produce large hail, upwards of two inches.  At this point the sun was setting and daylight was weakening; therefore, we called it a day.

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