made 3 fixes on Typhoon PATSY; and an aircraft of Navy VW-3 Squadron made 3 fixes on Typhoon HARRIET.
The method used by the 54th Weather Reconnaissance Squadron where-in typhoons were penetrated at the 700 millibar level was found to be completely satisfactory. Occasional penetrations at the 500 millibar level were found to be less reliable for several reasons: (1) Difficulty was encountered in locating the eye. (2) Cloud cover often made it impossible to observe the surface, thus precluding a determination of the wind speed in the immediate vicinity of the typhoon center. (3) When observed, estimates of surface wind speeds tended to be less; accurate than those made at the 700 millibar level.
There appears to be a high degree of correlation between the maximum wind speed reported by reconnaissance at the 700 millibar level in the vicinity of a fully developed typhoon and the maximum reported surface wind speed. In most cases, the maximum surface wind speed appears to be approximately 15 to 25 percent higher than the wind speed at the 700 millibar level. However, the foregoing statements are based on an incomplete investigation, and a more detailed study will be undertaken during the coming months, if a definite correlation can be established, a marked improvement should result in the accuracy of existing maximum wind speeds, as reported in issued typhoon warnings. It should be mentioned that the flight level wind measuring equipment, with which B-50 weather reconnaissance aircraft are now equipped, is extremely accurate. Winds measured with this equipment (APN/82, Doppler Navigation Equipment) are generally accurate to plus or minus one degree in direction, and plus or minus 5 knots in speed.
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