Severe Hazards
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Ground SurveysAn important component of a robust verification data set for storms in central Oklahoma will be storm damage surveys. This section provides guidance to SHAVE participants when a damage survey is required.
Survey alert and coordinationOnce you have identified the need for a survey, please send a message to the entire e-mail list below, and begin calling cell phone numbers to recruit participants. Information in the e-mail and phone calls should include the preliminary survey needs (e.g., "Yukon to Guthrie and Purcell to Shawnee tornado paths") and a proposed meeting time and location (e.g., "6 am Thursday in NWC 2820"). An e-mail thread might follow as the scope of the event and survey needs become better defined. Participants should respond as soon as possible to the messages with your intention to participate in the survey team and/or act in a support role at NWC. The person who initiated the messages will keep track of who is participating and in what role (surveyor or support desk) and will continue to recruit additional participants as necessary.
During and immediately following the event Begin setting up a survey support desk at the NWC. Monitor incoming media reports via local TV, commercial radio, and online media sources (i.e., local newspaper and TV news station web pages). Also monitor local emergency and amateur radio frequencies. Mark the location of known damage with a descriptive note in Google Earth. Find out from MPAR, CASA, and SMART-R teams the storms they have collected data on for more intense survey focus. Prepare rotation/damage track maps (paper and digital versions with street shapefile overlays). Get a rough idea of how many teams will be needed and what damage area assignments will be made. A rule of thumb is to assign no more than a 10-mile track of urban damage to any one team (though a single group may be able to survey larger rural events). Continue to recruit participants as needed. Make sure the Rotation Tracks products are online, preferably in Google Earth. Pre-survey During some major events, a joint meeting may occur between the WFO, SWAT group, and other groups before the beginning of the survey. The support desk should help coordinate such a meeting. As surveyors arrive, assist the formation of survey teams with at least 2 members on each team trained in EF scale damage assessment. Teams should be formed based on experience levels (at least one experienced surveyor per team) and technology available (try to spread out the gadgets as evenly as possible). Assignments to particular storm damage segments should be made on priority by the team's experience (i.e., more experienced teams to more significant damage), the data collected during the event (e.g., more experienced teams to damage paths where data were collected by MPAR), and chase activities during the event (i.e., assign surveyors to storms they chased). Before they depart, make sure the survey teams know the phone numbers for the NWC support desk and backup cell-phone(s), as well as which coordination amateur radio frequency to use (if applicable). Save the marked damage locations in Google Earth as waypoints and distribute to teams with digital mapping software and/or PDAs. Distribute rotation/damage track maps to teams on paper copy and/or as digital images. Also serve as a liaison to other survey teams from CASA, the WFO, etc. Determine GSA vehicle availability (if GSA vehicles will be used, review fuel purchase procedures with drivers). Locate and distribute the magnetic storm survey signs. During the survey Continue to monitor media reports and pass along key information to the appropriate survey team(s). Continue to serve as liaison to other survey teams. Pass along key results to the WFO as they are received from the field. Continue updating and refining the Google Earth damage map with reports from the media, WFO, and survey teams. Field calls from the survey teams and provide assistance as possible. Review radar data and make probing phone calls to uncover new damage. In high-impact events, make sure to communicate preliminary survey information to the WFO in time for media deadlines.
Field survey teamsEach survey team should have at least 2 participants who have completed EF-scale training (or at least one with EF training if short-handed). Assignments to each team will be made at the gathering time and location. People are encouraged to pair up based on the experience and technology available. Teams should each have at least one experienced surveyor, and the available technology should be spread out as evenly as possible among the teams. Assignments of teams to various damage areas will be made based on the team's experience (i.e., more experienced teams to areas of greater damage), the real-time data collected (e.g., most experienced team surveys storm scanned by the MPAR), and surveyors' chased storms. Survey team duties are outlined in this section:Pre-survey Participants should plan to arrive early in the morning following an event (or, in rare cases may gather immediately for a survey before sunset the day of an event). Begin packing and charging the batteries for all devices (the night before!). Check the "recommended survey pack list" at the end of this document. Note that normal services such as fast food, convenience stores, gas stations, ATM machines, etc., may be difficult to access in the wake of a major event, so be prepared before the survey begins with food, drinks, cash, and a full gas tank. Remember if there are not enough government vehicles available you may need to drive your own vehicle. Don't forget your government identification and perhaps wear an NSSL shirt. If using a GSA vehicle, know the fuel purchasing procedure. Also, bring 2 official government survey car magnets with you and place on the survey vehicle doors. Technical procedures Before arriving at the first damage site, synchronize all clocks and watches in the group to a common GPS time. Don't forget cameras, laptops, and PDAs. Turn on the GPS log feature and frequently check to make sure it is still logging. Take notes, including DI/DOD pairs on a PDA and/or in a notebook with time information on each note. Take at least one photo and/or video segment for every recorded DI/DOD pair. Make sure to include in photos/videos different perspectives of the damaged structure as well as its immediate surroundings.
Post-survey Save digital copies of everything as quickly as possible upon return to the NWC. Compose a brief narrative of your survey results, making sure to identify the max EF-scale and wind speed estimate and location for each tornado/wind damage path segment. Give the narrative to the NWC support desk and they will forward the information to the WFO. Later, as time permits, you will need to associate (via time) the GPS location logs with video clips, photos, notes, and DI/DOD pairs. |