Description of the GFS LAMP Alphanumeric Message


The GFS MOS-Based LAMP guidance is generated using the current station observations for the cycle time, analyses of the observations, simple model output, and the MOS data derived from NCEP's Global Spectral Model. To stay updated about the availability of GFS-LAMP guidance for the different cycle times, please refer to our Changes Document. This guidance is valid for stations in the United States, Puerto Rico, and the U.S. Virgin Islands. Please refer to the following document for the most recent station list. Forecast elements are valid from 1 to 25 hours in advance.

For a description of the current operational LAMP Alphanumeric Text Message, please see the following link:

https://www.weather.gov/mdl/lamp_desc

The information that follows applies to the new LAMP v2.2.0 Alphanumeric Text Messages, which are coming soon (September 2019).

Forecast elements are valid from 1 to 25 hours in advance, except from 1 to 38 hours for CIG, VIS, and OBV.

  • With LMP v2.2.0 and beyond, there are 3 types of ASCII text bulletins. They are:
  1. The standard bulletin which covers the 1-25 hour period.
  2. The extended bulletin which covers the 26-38 hour period.
  3. The full bulletin which covers the 1-38 hour period. This bulletin is currently only available via the LAMP website.

    The below example shows the full bulletin, but the key applies to all the bulletins.


 
LAMP Sample Message

KBWI   GFS LAMP GUIDANCE   2/22/2019  1230 UTC                                                                         
 DT /FEB  22                           /FEB  23                                                                /FEB  24 
 HR   01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 
 UTC  13 14 15 16 17 18 19 20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00 01 02 
 TMP  45 44 45 46 48 50 51 51 52 50 47 44 42 41 40 39 38 37 36 35 35 35 34 35 36999999999999999999999999999999999999999 
 DPT  25 24 24 24 23 22 22 22 22 23 24 25 26 26 27 27 26 26 26 26 25 25 25 26 26999999999999999999999999999999999999999 
 WDR  34 35 36 35 34 33 33 32 33 33 35 01 01 00 01 36 00 00 00 04 04 04 05 05 06 99 99 99 99 99 99 99 99 99 99 99 99 99 
 WSP  04 05 05 06 06 06 06 06 06 05 03 01 01 00 01 01 00 00 00 01 01 02 02 03 03 99 99 99 99 99 99 99 99 99 99 99 99 99 
 WGS  NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG999999999999999999999999999999999999999 
 PPO   2  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0999999999999999999999999999999999999999 
 PCO   N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  X  X  X  X  X  X  X  X  X  X  X  X  X  
 P06                  7                 6                 0                 5                44                94       
 LP1   0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0999999999999999999999999999999999999999 
 LC1   N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  X  X  X  X  X  X  X  X  X  X  X  X  X 
 CP1   1  0  0  1  1  1  2  1  1  1  1  0  0  0  0  0  0  0  1  1  1  1  1  1  1999999999999999999999999999999999999999 
 CC1   N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  X  X  X  X  X  X  X  X  X  X  X  X  X 
 POZ   1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  2  4  4  5  6  7  9 10  8999999999999999999999999999999999999999 
 POS  13 17 18 15 10  9  6  5  2  2  3  4  5  6  8 10 11 13 13 15 16 15 17 16 10999999999999999999999999999999999999999 
 TYP   R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  R  X  X  X  X  X  X  X  X  X  X  X  X  X 
 CLD  OV OV OV OV OV OV BK BK BK BK BK BK BK BK BK BK BK SC SC SC SC BK OV OV OV XX XX XX XX XX XX XX XX XX XX XX XX XX 
 CIG   7  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  8  7  7  6  6  6  5  4  4  3  2  2 
 CCG   7  7  6  6  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  6  7  7  7  7 99 99 99 99 99 99 99 99 99 99 99 99 99 
 VIS   7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  5  5  4  3 
 CVS   7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  7  6  6  6  6  5 99 99 99 99 99 99 99 99 99 99 99 99 99 
 OBV   N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N  N BR BR BR 
  • UTC Hour of the day in UTC time. This is the hour at which the forecast is valid, or if the forecast is valid for a period, the end of the forecast period.
  • TMP surface temperature valid at that hour.
  • DPT surface dewpoint 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.
  • WGS forecasts of the 10-meter wind gust at the hour, given in knots.  "NG" means that no gust is forecast.
  • PPO probability of precipitation occurring on the hour.  The precipitation need not be measurable.
  • PCO categorical forecast of yes (Y) or no (N) indicating if precipitation, not necessarily measurable, will occur on the hour.
  • P06 probability of measurable precipitation (PoP) during a 6-h period ending at that time.
  • LP1 probability of lightning (at least one total lightning flash) occurring during the 1-hr period ending at the indicated time.
  • LC1 categorical forecast of no (N), low (L), medium (M), or high (H) potential for lightning (at least one total lightning flash) occurring during the 1-hr period ending at the indicated time.
  • CP1 probability of convection (at least one total lightning flash and/or radar reflectivity of 40dBZ or higher) occurring during the 1-hr period ending at the indicated time.
  • CC1 categorical forecast of no (N), low (L), medium (M), or high (H) potential for convection (at least one total lightning flash and/or radar reflectivity of 40dBZ or higher) occurring during the 1-hr period ending at the indicated time.
  • POZ* conditional probability of freezing pcp occurring at the hour.  This probability is conditional on precipitation occurring.
  • POS* conditional probability of snow occurring at the hour.  This probability is conditional on precipitation occurring.
  • TYP* conditional precipitation type at the hour.  This category forecast is conditional on precipitation occurring.
  • CLD forecast categories of total sky cover valid at that hour.
  • CIG ceiling height categorical forecasts at the hour.
  • CCG conditional ceiling height categorical forecasts at the hour.   This category forecast is conditional on precipitation occurring.
  • VIS visibility categorical forecasts at the hour.
  • CVS conditional visibility categorical forecasts at the hour.   This category forecast is conditional on precipitation occurring.
  • OBV obstruction to vision categorical forecasts at the hour.

*In the contiguous United States, these products are available September 1 - May 31.


Definitions of Categorical Elements

LAV Ceiling Height (CIG) and
Conditional Ceiling Height (CCG) Categories
1 < 200 feet
2 200 - 400 feet
3 500 - 900 feet
4 1000 - 1900 feet
5 2000 - 3000 feet
6 3100 - 6500 feet
7 6600 - 12,000 feet
8 > 12,000 feet or unlimited ceiling
 
LAV Visibility (VIS) and
Conditional Visibility (CVIS) Categories
1 < 1/2 miles
2 1/2 - < 1 miles
3 1 - < 2 miles
4 2 - < 3 miles
5 3 - 5 miles
6 6 miles
7 > 6 miles
 

For numerical forecast
elements, missing values are
indicated by a 99 or 999


 
LAV Cloud (CLD) Categories
CL clear
FW few > 0 to 2 octas
SC scattered > 2 to 4 octas
BK broken > 4 to < 8 octas
OV overcast
 
LAV 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
 
LAV 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
X forecast is missing for this hour