1. Meteorología sinóptica Lección 05 Un ejemplo de análisis sinóptico aplicado a un estudio de caso

2. Changing gears…Coahuila tornado Occurred between 5:30 a.m. and 6:20 a.m. on Monday 25 May 2015 Destroyed 110 houses and partially damaged 764 Killed 14 people Rated EF-3 on the Fujita scale (EF-0 is weakest; EF-5 is strongest)

3. Because of very close proximity to the Del Rio, TX radar, the path of the supercell (in red) was relatively easy to determine The tornado path (yellow) was not as easy, as it required careful analysis of datamge. – I personally dispute the “left hook” portion of the tornado track as that is extraordinarily unusual, and the two undergraduate students who analyzed the track likely were unable to distinguish tornado damage from regular thunderstorm wind damage (I probably wouldn’t either, as it takes good training to tell the difference) Supercell thunderstorm (red) and Ciudad Acuña (yellow) tornado

4. Climatología de tornados

5. Orientación al area Need to make a fig. with: – Topography contours (shaded) – KDFX radar – Ciudad Acuña – Del Rio, TX sounding

6. Fig. 2: 0728, 0832, 0930, 1003, 1022, 1032 Figure 2: Base reflectivity (dBZ) at 0.5° tilt from Del Rio, TX KDFX. All times in UTC (subtract 5 h for local time) on 25 May 2015. White arrows indicate traceable reflectivity that became the supercell thunderstorm that produced the Ciudad Acuña tornado (tornado occurred between approximately 1030 UTC and 1115 UTC). 70 65 60 55 50 45 40 35 30 25 20 15 10 5

7. Fig. 3: 1042, 1052, 1103, 1113, 1124, 1134 Figure 3: As in Fig. 2, but for 1042 UTC to 1134 UTC 25 May 2015.

8. Fig. 4: 1200, 1258, 1359, 1500, 1600, 1700 Figure 4: As in Fig. 2, but for 1200 UTC to 1700 UTC 25 May 2015.

9. Fig. 5: radar rotation swaths Figure 5: Rotation tracks (in s -1 ), from NSSL On Demand. Black dot indicates location of Ciudad Acuña and red curve indicates continuous track of discete radar echoes from KDFX WSR-88D 0.5° base reflectivitiy product between 0728 UTC and 1700 UTC 25 May 2015. Faint black curves indicate terrain height above sea level, contoured every 250 m.

10. Fig. 6: 500mb ht, 850mb wind, 2m dpt 0000 UTC0600 UTC1200 UTC 0000 UTC0600 UTC1200 UTC a bc d ef Figure 6: Height at 500 hPa (in m, contoured every 60 m in a-c and every 20 m in d-f), 850-hPa wind (vector, scaled in all panels to reference maximum vector of 33.0 m s -1 ), and 2-m dew point temperature (°C), all from the North American Regional Reanalysis (NARR). Panels a and d correspond to 0000 UTC 25 May 2015, panels b and e to 0600 UTC 25 May 2015, and c and f to 1200 UTC 25 May 2015. Gray box in panel a indicates zoomed region in panels d-f. Black circle in all panels indicates location of Ciudad Acuña (where tornado fatalities were reported). Red curve in panels d-f indicates continuous track of discete radar echoes from KDFX WSR-88D 0.5° base reflectivitiy product between 0728 UTC and 1700 UTC 25 May 2015. Red circles along trajectory indicate thunderstorm positions at 0900 UTC, 1200 UTC, and 1500 UTC, respectively. Faint black curves indicate terrain height above sea level, contoured every 250 m.

11. Fig. 7: 00 and 12 UTC soundings Figure 7: Radiosonde observations from Del Rio, TX (KDRT) from 0000 UTC 25 May 2015 (1900 local time 24 May 2015) and 1200 UTC 25 May 2015 (0700 local time 25 May 2015). In both panels, temperature is in red and dew point temperature in blue (°C). Wind speeds in kt.

12. Fig. 8: sfc moisture advection 0300 UTC 0600 UTC 0900 UTC 1200 UTC d c b a Figure 8: Surface moisture advection given as the scalar product between the horizontal 10-m wind vector and the gradient of 2-m specific humidity (colors, in units of kg kg -1 s -1 multiplied by 100) and 10-m wind (vectors, scaled in all panels to reference maximum vector of 17.8 m s -1 ), both from the North American Regional Reanalysis (NARR). Panels a-d correspond to 0300 UTC, 0600 UTC, 0900 UTC, and 1200 UTC 25 May 2015, respectively. As in Figure 1, black circle indicates location of Ciudad Acuña (where tornado fatalities were reported). Red curve in all panels indicates continuous track of discete radar echoes from KDFX WSR-88D 0.5° base reflectivitiy product between 0728 UTC and 1700 UTC 25 May 2015. Red circles along trajectory indicate thunderstorm positions at 0900 UTC, 1200 UTC, and 1500 UTC, respectively. Faint black curves indicate terrain height above sea level, contoured every 250 m.

13. Fig. 9: sfc moisture convergence 0300 UTC 0600 UTC 0900 UTC 1200 UTC d c b a Figure 9: As in Figure 8, but for horizontal surface moisture convergence, also in units of kg kg -1 s -1, calculated as the horizontal divergence of the product between 2-m specific humidity and the horizontal 10-m wind vector.

14. Fig. 10: surface-based CAPE 0300 UTC 0600 UTC 0900 UTC 1200 UTC d c b a Figure 10: As in Fig. 8, but for surface-based CAPE (in J kg -1 ).

15. Fig. 11: 0-3 km srh 0300 UTC 0600 UTC 0900 UTC 1200 UTC d c b a Figure 11: As in Figure 10, but for 0-3 km Storm-Relative Helicity (SRH, m 2 s -2 ).