New Fire Danger Model Released Today

We are happy to announce that our new higher-resolution fire danger model is now operational on the OK-FIRE website.  This model has been developed over the past five years and utilizes different satellite data and a revised fuel model map.

The model has a greater spatial resolution of 500 m (versus the 1-km resolution of the earlier model).  A new satellite source (MODIS) provides 500-m greenness data with which to calculate relative greenness, in contrast to the earlier source (AVHRR) which provided 1-km data.  Also a revised default fuel model map is also 500-m resolution, in contrast to the 1-km resolution of the earlier fuel model map.

The model also has greater resolution in time.  Satellite data (7-day MODIS composites) are updated daily in contrast to the weekly updates of the earlier AVHRR satellite composites.  This will result in faster detection of changes in surface greenness.  The fire model itself is also being run more frequently (every 15 minutes) than before (every hour), which will result in greater near-real-time assessment of fire danger.  Fire danger model output for “current” conditions should now be no older than 25-35 minutes, whereas before, the output could be as old as 1.5 hours.

There are two important issues of which the OK-FIRE user needs to be aware. The first deals with the new fuel model map and revised suite of fuel models.  The second deals with the temporary slowness of the data download process.

The new default fuel model map is substantially different than the old map.  This has resulted, in many cases, in the changing of the default fuel model assigned to a given Mesonet station.  Thus if you had been using Model T for your Mesonet site, the default fuel model may now be Model L or even Model A. In particular, we are now using Model A for agricultural and urban areas, so if your station is in one of these areas, it may now be assigned Model A.  As a result, there are now a LOT of Mesonet stations being assigned default fuel model A.  If you want the fuel model to represent greater fuel loads, you’ll need to change it back to Model L or T (the other “grassy models”). 

You can change the fuel model back to what you wish for any Mesonet site by going to the “Station Fuel Model Options” page, whose link is at the bottom of the left menu on the home page.  The new suite of nine fuel models available for any Mesonet site (for chart and table products) are Models A, L, T (the grassy models); Models B and F (the brushy models); Models G, P, and R (the forest models); and Model K (the slash model).  For a full description of these fuel models along with photos please go to the “Fuel Models Description” page, whose link can be found on the “Station Fuel Model Options” page.  The default fuel model map (upon which the fire danger model output map products for BI, SC, ERC, and IC are based) utilizes the following seven fuel models:  A, L, T, B, F, P, and R.  You can view the new default fuel model map by clicking “Default Fuel Model Map” in the left menu section of the home page.

The other important issue of which the OK-FIRE user will need to be aware is the slowness (quite marked in some cases) of the data download process due to the less than ideal current configuration of the computer systems involved and how they are accessing the fire danger data.  We expect this situation to be corrected sometime over the summer, resulting in faster download speeds for fire danger products.  The slowness is particularly marked in products involving any variables from the fire danger model (e.g., BI, SC, dead fuel moisture) and affects download times for animated maps, charts, and tables in both the forecast and past modes. In particular, download of past fire danger model data (going back many days or months) can be markedly slower (on the order of minutes) than what the OK-FIRE user has been accustomed to.  Again, this situation will be remedied over the summer, but we ask your patience in the meantime.

Aside from the new fire danger model with its revised fuel model distribution and new satellite data, the OK-FIRE website itself remains essentially the same as before, so there should be no learning curve for current users.  However, to ensure the website changes load properly on your device, please CLEAR YOUR BROWSER CACHE AND OFFLINE FILES.  If you have any technical questions on the new fire danger model, please contact Dr. J. D. Carlson (OK-FIRE Program Manager) at jdc@okstate.edu .  For website problems or other issues, please contact the on-duty Mesonet operator at operator@mesonet.org or call 405-325-2541.