Page:CAB Accident Report, American Airlines Flight 6001.pdf/7

 A summary of the weather reports for the Los Angeles area from 1230 to 0430 is as follows:

In the San Fernando Valley ceilings and visibility were variable with below minimums prevailing over most of the period but with occasional periods of marginal conditions slightly above minimums occurring at Burbank. On the ocean side of the Santa Monica Mountains instrument conditions ware reported during the first two hours of the period but coiling was reported as 900 to 1200 feet at the Los Angles Municipal Airport during the remainder of the period. Throughout the area occasional light drizzle was occurring and temperature was reported in the low fifties with the dew point only a few degrees lower.

The following sequence of observations was made and recorded by the Weather Bureau at Burbank on January 10, 1945:

Records *

0222

Instrument, measured 700, overcast, 1 rule, light drizzle, light fog, 1020.3 millibars, 51, 49, ESE 3, 30.12 inches.

Local Extra *

0245

Instrument, measured 700, overcast, 1 1/4 miles, light drizzle, light fog.

Special *

0300

Instrument, measured 700, overcast, 2 miles, light fog, 1020.3, 51, 49, ESE 3, 30. 12.

Local Extra

0315

Instrument, measured 700, overcast, 2 miles, light fog.

Record

0323

Instrument, measured 700 variable, overcast, 2 rules, light fog, 1020. 3, 51, 49, SSW 4, 30.12, ceiling variable 600 to 700.

Local Extra

0345

Instrument, measured 600 variable, overcast, 1 1/2 rules, light fog, ceiling variable 400 to 600.

Check *

0400

Same as previous observation.



Types of Weather Bureau Observations

"Record"

A complete meteorological observation taken once each hour for transmission by radio or teletype.

"Special"

A "special" is required at any time an important change in weather conditions takes place, rules for which are specified in Circular N.

"Local Extra"

These are required at designated terminal and intermediate airport stations each 15 minutes when the ceiling becomes less than 600 feet and/or the visibility is less than l 1/4 rules, also upon request by an airline, private pilots or pilots and officials of the military or other organizations.

"Check"

An observation taken once an hour, midway between record observations to confirm or amend the last recorded observation.