Description of the AVN MAV MOS Alphanumeric Message


The AVN-Based MOS MAV guidance is generated from 0000 UTC and 1200 UTC model output from the Aviation (AVN) run of NCEP's Global Spectral Model. This guidance is valid for 1060 stations in the United States and Puerto Rico. Forecast elements are valid from 6 to 72 hours in advance.



Sample Message

KSLC   AVN MOS GUIDANCE    1/25/2001  1200 UTC
DT /JAN  25/JAN  26                /JAN  27                /JAN  28
HR   18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 06 12
N/X                    18          39          26          38    24
TMP  37 39 39 35 28 24 21 22 28 36 36 35 33 30 30 30 33 35 33 32 27
DPT  21 16 14 19 18 16 14 15 19 25 32 32 29 26 26 22 31 26 27 29 25
CLD  SC SC SC CL CL SC SC BK BK OV OV OV OV OV OV OV OV OV OV OV OV
WDR  27 28 27 24 21 18 16 14 14 17 13 18 19 17 14 13 16 19 22 30 28
WSP  16 13 10 04 02 02 04 03 04 06 04 04 06 08 07 05 11 12 06 01 04
P06         1     0     0    12    30    26    30    52    60 34 26
P12                     1          33          53          79    43
T06      0/ 0  0/ 0  0/ 0  0/ 0  1/ 0  2/ 0  1/ 1  3/ 0  5/ 1  2/ 0
T12            0/ 0        0/ 0        2/ 0        4/ 1    16/ 1
POZ   1  0  0  0  0  0  0  0  1  0  0  0  0 10 27 11  8  0  0  0  1
POS  56 48 70 85 96100100100 67 26 22 27 30 29 30 53 51 54 50 37 45
TYP   S  R  S  S  S  S  S  S  S  R  S  R  R  R  Z  S  S  S  S  R  R
Q06         0     0     0     0     1     1     1     2     2     1
Q12                     0           1           2           3     2
SNW                                 1                       2      
CIG   7  7  7  7  7  7  7  7  7  7  7  7  7  6  5  5  3  3  4  4  4
VIS   7  7  7  7  7  7  7  7  7  7  7  7  7  6  6  4  3  4  6  7  7
OBV   N  N  N  N  N  N  N  N  N  N  N  N  N BR BR FG FG FG BR  N  N


  • HR = Forecast hour, i.e. how many hours from the model run time.
  • N/X = daytime minimum/nightime maximum surface temperatures.
  • TMP = surface temperature valid at that hour.
  • DPT = surface dewpoint valid at that hour.
  • CLD = forecast categories of total sky cover valid at that hour.
  • WDR = forecasts of the 10-meter wind direction at the hour, given in tens of degrees.
  • WSP = forecasts of the 10-meter wind speed at the hour, given in knots.
  • P06 = probability of precipitation (PoP) during a 6-h period ending at that time.
  • P12 = PoP during a 12-h period ending at that time.
  • T06 = probability of thunderstorms/conditional probability of severe thunderstorms during the 6-hr period ending at the indicated time.
  • T12 = probability of thunderstorms/conditional probability of severe thunderstorms during the 12-hr period ending at the indicated time.
  • POZ = conditional probability of freezing pcp occurring at the hour.
  • POS = conditional probability of snow occurring at the hour.
  • TYP = conditional precipitation type at the hour.
  • Q06 = quantitative precipitation forecast (QPF) category for liquid equivalent precipitation amount during a 6-h period ending at that time.
  • Q12 = QPF category for liquid equivalent precipitation amount during a 12-h period ending at the indicated time.
  • SNW = snow fall categorical forecasts during a 24-h period ending at the indicated time.
  • CIG = ceiling height categorical forecasts at the hour.
  • VIS = visibility categorical forecasts at the hour.
  • OBV = obstruction to vision categorical forecasts at the hour.



Definitions of Categorical Elements

MAV Ceiling Height Categories
1 < 200 feet
2 200 - 400 feet
3 500 - 900 feet
4 1000 - 3000 feet
5 3100 - 6500 feet
6 6600 - 12,000 feet
7 > 12,000 feet or unlimited ceiling


MAV Visibility (VIS) Categories
1
<= 1/4 miles
2
> 1/4 - 1/2 miles
3
> 1/2 - < 1 miles
4
1 - < 3 miles
5
3 - 5 miles
6
6 miles
7
> 6 miles


MAV QPF Categories
0 no precipitation
1 0.01 to 0.09 inches
2 0.10 to 0.24 inches
3 0.25 to 0.49 inches
4 0.50 to 0.99 inches
5 1.00 to 1.99 inches
6 2.00 inches or greater
MAV Cloud (CLD) Categories
CL clear
SC scattered > 0 to 4 octas
BK broken > 4 to < 8 octas
OV overcast


MAV Obstruction to Vision (OBV) Categories
N none of the following
HZ haze, smoke, dust
BR mist (fog with visibility >= 5/8 mile)
FG fog or ground fog (visibility < 5/8 mile)
BL blowing dust, sand, snow


MAV Snow Fall Amount Categories
0 no snow or a trace expected
1 > a trace to < 2 inches
2 2 to < 4 inches
4 4 to < 6 inches
6 6 to < 8 inches
8 >= 8 inches


MAV Precipitation Type (TYP) Categories
S pure snow or snow grains
Z freezing rain/drizzle, ice pellets, or
anything mixed with freezing precip
R pure rain/drizzle or rain mixed with snow

 
 
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Last Updated January 31, 2001