FORMATO DE LOS DATOS DIARIOS DE SUPERFICIE POR ESTACIÓN / FUENTE NOAA
DETAILS/FORMATGlobal summary of day
data for 18 surface meteorological elements
are derived from the
synoptic/hourly observations contained in
TD9956 (USAF DATSAV3
Surface data).
In deriving the summary
of day data, a minimum of 4
observations for the
day must be present (allows for stations which
report 4 synoptic observations/day).
Since the data are converted
to constant units (e.g,
knots), slight rounding error from the
originally reported
values may occur (e.g, 9.9 instead of 10.0).
The mean daily values
described below are based on the hours of
operation for the station.
For some stations/countries, the
visibility will sometimes
'cluster' around a value (such as 10
miles) due to the practice
of not reporting visibilities greater
than certain distances.
The daily extremes and totals--maximum
wind gust, precipitation
amount, and snow depth--will only appear
if the station reports
the data sufficiently to provide a valid value.
Therefore, these three
elements will appear less frequently than
other values.
Also, these elements are derived from the stations'
reports during the day,
and may comprise a 24-hour period which
includes a portion of
the previous day. The data are reported and
summarized based on
Greenwich Mean Time (GMT, 0000Z - 2359Z) since
the original synoptic/hourly
data are reported and based on GMT.
As for quality control
(QC), the TD9956 data undergo extensive
automated QC (by USAF,
over 400 algorithms) to correctly 'decode'
as much of the synoptic
data as possible, and to eliminate many
of the random errors
found in the original data. Then, these data
are QC'ed further as
the summary of day data are derived. However,
we expect that a very
small % of the errors will remain in the
summary of day data.
The record length is 132.
FIELD
POSITION TYPE DESCRIPTION
(LOS DATOS ALMACENADOS EN EL BANCO
DE DATOS, ESTAN EN UNIDADES METRICAS)
STN
1-6 Int. Station number
(WMO/DATSAV3 number)
for the location.
YEAR 9-12 Int. The year.
MODA 13-16 Int. The month and day.
TEMP
19-24 Real Mean temperature for the
day in degrees
Fahrenheit to tenths. Missing = 9999.9
(Celsius to tenths for metric version.)
Count 26-27
Int. Number of observations used in
calculating mean temperature.
DEWP
30-35 Real Mean dew point for the day
in degrees
Fahrenheit to tenths. Missing = 9999.9
(Celsius to tenths for metric version.)
Count 37-38
Int. Number of observations used in
calculating mean dew point.
SLP
41-46 Real Mean sea level pressure
for the day
in millibars to tenths. Missing =
9999.9
Count 48-49
Int. Number of observations used in
calculating mean sea level pressure.
STP
52-57 Real Mean station pressure for
the day
in millibars to tenths. Missing =
9999.9
Count 59-60
Int. Number of observations used in
calculating mean station pressure.
VISIB 63-67
Real Mean visibility for the day in miles
to tenths. Missing = 999.9
(Kilometers to tenths for metric version.)
Count 69-70
Int. Number of observations used in
calculating mean visibility.
WDSP
73-77 Real Mean wind speed for the
day in knots
to tenths. Missing = 999.9
(Meters/second to tenths for metric version.)
Count 79-80
Int. Number of observations used in
calculating mean wind speed.
MXSPD 83-87
Real Maximum sustained wind speed reported
for the day in knots to tenths.
Missing = 999.9
(Meters/second to tenths for metric version.)
GUST
90-94 Real Maximum wind gust reported
for the day
in knots to tenths. Missing = 999.9
(Meters/second to tenths for metric version.)
MAX
97-102 Real Maximum temperature reported
during the
day in Fahrenheit to tenths--time of max
temp report varies by country and
region, so this will sometimes not be
the max for the calendar day. Missing =
9999.9
(Celsius to tenths for metric version.)
Flag
103-103 Char Blank indicates max temp was taken
from the
explicit max temp report and not from the
'hourly' data. * indicates max temp was
derived from the hourly data (i.e., highest
hourly or synoptic-reported temperature).
MIN
105-110 Real Minimum temperature reported during
the
day in Fahrenheit to tenths--time of min
temp report varies by country and
region, so this will sometimes not be
the min for the calendar day. Missing =
9999.9
(Celsius to tenths for metric version.)
Flag
111-111 Char Blank indicates min temp was taken
from the
explicit min temp report and not from the
'hourly' data. * indicates min temp was
derived from the hourly data (i.e., lowest
hourly or synoptic-reported temperature).
PRCP
113-117 Real Total precipitation (rain and/or melted
snow) reported during the day in inches
and hundredths; will usually not end
with the midnight observation--i.e.,
may include latter part of previous day.
.00 indicates no measurable
precipitation (includes a trace).
Missing = 99.99
(For metric version, units = millimeters
to tenths & missing = 999.9.)
Note: Many stations do not report '0' on
days with no precipitation--therefore,
'99.99' will often appear on these days.
Also, for example, a station may only
report a 6-hour amount for the period
during which rain fell.
See Flag field for source of data.
Flag
118-118 Char A = 1 report of 6-hour precipitation
amount.
B = Summation of 2 reports of 6-hour
precipitation amount.
C = Summation of 3 reports of 6-hour
precipitation amount.
D = Summation of 4 reports of 6-hour
precipitation amount.
E = 1 report of 12-hour precipitation
amount.
F = Summation of 2 reports of 12-hour
precipitation amount.
G = 1 report of 24-hour precipitation
amount.
H = Station reported '0' as the amount
for the day (eg, from 6-hour reports),
but also reported at least one
occurrence of precipitation in hourly
observations--this could indicate a
trace occurred, but should be considered
as incomplete data for the day.
I = Station did not report any precip data
for the day and did not report any
occurrences of precipitation in its hourly
observations--it's still possible that
precip occurred but was not reported.
Note: Flags H and I only apply to Version 6 data.
SNDP
120-124 Real Snow depth in inches to tenths--last
report for the day if reported more than
once. Missing = 999.9
(Centimeters to tenths for metric version.)
Note: Most stations do not report '0' on
days with no snow on the ground--therefore,
'999.9' will often appear on these days.
FRSHTT 127-132
Int. Indicators (1 = yes, 0 = no/not
reported) for the occurrence during the
day of:
Fog ('F' - 1st digit).
Rain or Drizzle ('R' - 2nd digit).
Snow or Ice Pellets ('S' - 3rd digit).
Hail ('H' - 4th digit).
Thunder ('T' - 5th digit).
Tornado or Funnel Cloud ('T' - 6th
digit).
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