SECRET safety point and questionablefor drone @ photographicmissions. . A statisticalcheck on the speed of these pressure troughs wae made. A series of five troughs were studied aml the results indicated that at this season, the time for traversing the distance from the Japanese coastal areas to Eniwdok, a distance of appmximatel,y 2100 nautical miles, varied from 5 to 7 days. It wae concluded that if the trough continued to travel on 10 May at a nomal rate, a prediction for its arrival in the Eniwetok area on the very day that Zebra day was scheduled was justified. However, before xwcozmnending to the Commander,JTF 7 that Zebra should be advanced one day, the staff ~teorologists agreed to scrutinize the development of this trough for another 24 hours. The reason for this was the fact that the txmugh hai ehown some itication of weakening, which would retard its eastward migration considerably. This was confirmed on the subsequentweather charts ad no recommxiation to advance Zebra day was made. The considerableamounts of high clouds in the Eniwetok area on Zebra minus four iticated strongly that the Intertropicalfrent was not too far to the south. The weather reconnaissanceon Zebra dnus four flew track five ad SIX ami the observationshdicated heavy clowiinese exterrii~ In a broad east-west belt at all levels fmm Kwajelein area southward. 2. Operations Zebra day was scheduled for 15 Uay ami “H” Hour for 06W. By I ‘1 Zebra zd.nusthree (12 May) the pressure gradient between Wake Islad SECTION XII 54 . SECRET I I