Instability Approximation for Woodward Tornado

                                The raob network was in its infancy in the late 1940's. Upper air data were fairly sparse and undependable. Unfortunately, NCDC
                                has lost these data. I did manage to obtain some UA maps for 03 UTC for the late 1940s from Bobby Prentice. These maps are
                                fairly hard to read, but I still managed to reconstruct the 500mb chart for 03 UTC April 10, 1947. 

                                                             
                                A tornado developed WSW of Pampa at 541 pm and passed north of Pampa by 610 pm. The surface observations around this
                                time showed fairly high surface dewpoints in the upper 50s and lower 60s with surface temperaures on the rise south of the warm
                                front. At 530 pm and 630 pm the T/TD were 64F/61F and 69F/59F respectively. The elevation of Pampa is about 3250ft. The
                                station pressure was 886mb. Using a skew-T log-P diagram, one can easily find the lifted index at Pampa assuming 500mb temp.
                                around -15C. This 500mb temp was estimated based on the 03 UTC 500mb temps at FTW, BSP, OMA, LBF and DDC.
                                Lifting 64F/61F up the dry adiabat and then up the moist adiabat to 500mb yields -7C. So the lifted index was around
                                 -8  at Pampa when the storm was to the WSW. After the storm moved north the T/TD were 69F/59F, which has nearly the same
                                theta-e as before.  Further east at Gage(elevation 2200ft or 920mb), the T/TD were 67F/63F at 730 pm. The theta-e was almost identical
                                at Gage(340K). Even though surface potential temperature was slightly lower at Gage than Pampa, the mixing ratio was slightly higher.