Page 30 - AFMAN 15-111, 12 MAR 2019

30 AFMAN15-111 12 MARCH 2019

6.7.1.2. No time entries are made on the rows captioned “MID (LST).” (i.e. The bottom
row)

6.7.2. Column 43 - “NO.” There is no entry made in this column; the numbers are here for
informational purposes to denote the 4 rows in the other synoptic data columns.

6.7.3. At the specified observation times, measure the amounts of each phenomenon and
record this information in the corresponding columns and rows. Note: The first and last rows
are only used by stations taking midnight LST observations.

6.7.3.1. At stations taking midnight LST observations, the first row is the measured
amounts that occurred from midnight LST until the time of the first 6-hourly observation.
The last row is the measured amounts that occurred from the time of the last 6-hourly of
the day until midnight LST.
6.7.3.2. Limited-Duty Units. Use the following procedures for the first precipitation where
one or more 6-hourly observations are missed while closed.
6.7.3.2.1. Using the rows corresponding with the first 6-hourly observation time that
occurs after opening, measure the amounts of each phenomenon that occurred since the
last recorded entries and record this information in the corresponding columns.
6.7.3.2.2. Prefix the entry with an asterisk (*) and enter a remark in column 90 to
indicate the actual amount of time that has passed since the last record (e.g. “*0.36” is
entered in Column 44 and “*42-HR PCPN FOR 0350 MEASURMENT” is entered in
column 90).

6.7.4. Column 44 - Precipitation is a volumetric measurement of all precipitation that occurred
during the period of observation (to include the water equivalent of solid precipitation) and is
reported to the nearest hundredth inch (0.01); encode amounts less than 0.005in as a trace.
Once this measurement is recorded, the collection device is emptied.

6.7.4.1. To determine the water equivalent of solid precipitation, use a known amount of
water to melt any solid precipitation. Take a measurement and then subtract the known
amount that was added; the resulting measurement is total amount including the water
equivalent of solid precipitation.
6.7.4.2. If the water equivalent of solid precipitation cannot be measured, enter an
estimated amount using a standard 1:10 ratio; or other ratio where there is evidence that it
is more appropriate for the individual storm or location.
6.7.5. Column 45 - Snow Fall is a measurement of the depth of new freezing/solid
precipitation that has occurred since the last synoptic observation and is reported to the nearest
tenth inch (0.1); encode amounts less than 0.05in as a trace. This measurement is taken in a
place cleared of solid precipitation at the beginning of the observation period (previous 6
hours) in order to provide a representative sample that does not include an accumulation
outside the observation period.
6.7.5.1. If solid precipitation melted as it fell, consider the amount to be estimated and
annotate Column 90 with “E-MELTED AS IT FELL.”

6.7.5.2. If the precipitation consists entirely of hail, prefix the entry with an “*” and
annotate in Column 90 with “*HAIL IN COL 45 AT 0250.”