Condon Report: 10-X. [371-B.] Continental Divide, N. M., 26 January 1953, 2115-2200 LST. Weather: high, thin overcast, low scattered clouds, very good visibility. An airman stationed at the 769th AC&W Squadron at Continental Divide (elevation 7,500 ft.) observed a "bright reddish-white object" about 10 mi. west of the radar site and approximately 2,000 ft. above the terrain. The radar subsequently painted a strong, steady return at 9 mi. range and about 2,500-7,500 ft. above the surface. This object passed behind a nearby hill and reappeared, heading north at about 10-15 mph. Radar track confirmed this. The object then moved to the west at 12-15 mph to a point 18 mi. west of the radar site. It then turned north for about 10 mi., and subsequently turned back on a heading of 128° inbound to the station. Radar and visual contact was lost near the area where the object was first detected. Before disappearing, the object seemed to shrink in size and fade in color to a dull red.

There seems to be little doubt in this case that the visual and radar contacts were in fact of the same object. The obvious interpretation is that the object seen and tracked on radar was a weather balloon, a lighted pibal used for obtaining data on upper winds. This explanation was considered and rejected by Air Force investigators for two reasons:

- The sighting occurred 1 hr. 15 mm. after the scheduled release of the Winslow, Ariz. pibal, the only one that seemed likely to have showed up in the sighting area, and the balloon ought to have burst by then, since they generally burst at 30,000 ft., an altitude the Winslow pibal should have reached 25 min. after launch;

- The reported direction of movement was, at least part of the time, directly opposite to the reported upper winds as derived from the Albuquerque radiosonde flight. These winds were reported from the "west between 10,000 and 30,000 feet."

Actually, neither of these two reasons is sufficient to discount the balloon theory. In the first place, weather balloons are often released later than the scheduled time, and this possibility was apparently not checked. In the second place, pibal balloons are often known to leak and consequently to rise at a much slower rate than normal. Often they have so little buoyancy that they may be caught in local updrafts or downdrafts. These leaking balloons are usually carried away by the horizontal wind flow at such a rate that they are lost from sight of the observing station before they reach burst altitude. The pibal data from Winslow, Ariz. for 0300 GMT 27 January 1953, (2000 LST 26 January) is listed as "missing" above the 500 mb level (about 19,000 ft. m.s.l.), which is a strong indication that the balloon may have been leaking. It is therefore entirely conceivable that the Winslow pibal balloon could have been in the vicinity of Gallup, N. M. (west of the radar site) at 2115 LST on the night in question.

The problem of the observed direction of movement cannot be completely resolved, because it depends largely on an analysis of mesoscale winds in the lower atmosphere, that is, on a scale smaller than ordinarily analyzed n synoptic weather maps. The synoptic maps for 2000 LST 26 January 1953, for the 700 mb (about 10,000 ft.), 500 mb (about 19,000 ft.), and 300 mb (about 27,000 ft.) levels are shown in Figs. 10 and 11.

Although the general windflow in the Arizona-New Mexico area for at least the 700 and 500 mb maps is from the west, there are indications of a secondary mesoscale circulation somewhere in the vicinity of the Arizona-New Mexico border, which is embedded in the general trough overlying the southwestern states. Especially significant are the winds at the 700 and 500 mb levels at Tucson and at Phoenix, mainly at the 500 mb level, which show evidence of a mesoscale cyclonic circulation in the area.

In view of the general meteorological situation at the time, a quite likely explanation for the Continental Divide sighting is as follows: The Winslow pibal balloon, which was leaking, was carried away to the east, probably sinking slowly as it went, and was lost from view of the Winslow weather station. Upon reaching the general vicinity of Gallup, N. M. the leaking balloon was probably caught up in a local cyclonic vortex and updraft, which, being instigated by the mesoscale cyclonic flow in the region may have formed on the windward side of the range of low mountains forming the Divide in that area. This would have caused the balloon to be carried toward the north, slowly rising, as first observed. This would be followed in sequence by a turn to the west, and ultimately, upon reaching a somewhat higher level, a turn toward the southeast again as the balloon became caught in the more general flow from the west and northwest prevailing at middle levels in the atmosphere.

This hypothesis fits the details of the observations rather well, and considering the lack of additional information or data pertaining to this incident, the UFO should probably be tentatively identified as a weather balloon.

Google map of this location.