I am in Fire Central here in So. California, yet my data seems to think I am at a “Low” risk. The FWI Index does seem to fluctuate, though not very frequently, and the rest of the numbers don’t move much, if at all… can anybody who uses this data verify that these things are indeed working? I’ve been taking snapshots for a week now and only the FWI number has changed, while our temp and humidity have been all over the board this week… seems suspicious!
I am in Fire Central here in So. California, yet my data seems to think I am at a "Low" risk. The FWI Index does seem to fluctuate, though not very frequently, and the rest of the numbers don't move much, if at all... can anybody who uses this data verify that these things are indeed working? I've been taking snapshots for a week now and only the FWI number has changed, while our temp and humidity have been all over the board this week.. seems suspicious!
Your FWI does look suspicious. Did you setup
I’m here in “Fire Central” too, mountains of Colorado where I can actually smell smoke at the moment, hot and very, very dry, yet mine says “Low” too.
I tried to use it for awhile and gave up. Although I haven’t seen it said anywhere, I think you need to plug in some of the values that the drop down asks you to set, to get an accurated reading. Now, where you get those locally is a excellent question. I’ve asked some of our fire people and only get a blank stare. If they know, they don’t want to say. I think they’d rather we depend on them and not figure it ourselves, to be honest with you. If you find a source, let us know.
Although I haven't seen it said anywhere, I think you need to plug in some of the values that the drop down asks you to set, to get an accurated reading.
It looks to me that you two are in an High FWI area. You could try the following values as a starting value in 'View, Daily Fire Weather Index' and see what develops after a few weeks.
I don’t understand the purpose, then. Looks like we’re in a High FWI area (my nose tells me that) so plug in some values to get there??
I’m not trying to be sarcastic, I appreciate your help, but would like to be a little scientific anyway.
Bear in mind that the FWI being used was established for use in forested areas primarily (trees and such), and is not necessarily the most applicable for the fuels found in Southern California (I spent about 20 years doing wildland fire mgmt in SoCal, by the by). The FWI feature in Weather Display does indeed work, but always starts out from a baseline of zero. To have it be accurate, either at first or ever for that matter, you will need to enter initial values. If the initial values are valid, then WD will accurately compute the fire weather index.
This FWI model is not used by wildland fire agencies in SoCal. The most commonly used model is the National Fire Danger Rating System (NFDRS), which unfortunately doesn’t lend itself to automation of this nature as factors include moisture percentrage of fuel sticks which are manually measured and entered, the Ketch-Byran Drought Index, and other factors that must be externally obtained. But with valid and appropriate initial values, the Weather Display FWI will faithfully calculate the fire weather index as used in Canada and NZ; it won’t be tremendously applicable to the fuel models in SoCal like grass, chamise, manzanita, etc.
Fuels in SoCal are what are called 1-hour timelag fuels and 10-hour timelag fuels; the FWI is primarily geared toward 1000-hour timelag fuels and secondarily 10-hour timelags. Oversimplistically, these timelags refer to how many hours it would take a certain type of fuel to reach it’s equilibrium moisture content at a constant temperature and humidity. 1-hour fuels are things like grass and forbs with a branch diameter of 1/4" or less; 10 hour fuels have a branch diameter of up to 1 1/2", and 1000 hour fuels are basically trees.
A major limitation of both the FWI and the NFDRS are that both use a snapshot of conditions taken at 1PM, and as you’ve seen, fire weather conditions can change drastically throughout the course of the day. Not a fault of Weather Display at all, WD is faithfully following the stated protocol for use of the model.
the fwi actualy builds up on long term values
the drought code (DC) is one of the important things, as well as the current 24 hour average temperature, windspeed and humidity
(note, i need to fix a new bug where yesterdays reading is the same as today, just have not got around to fixing that)
Hey everyone, wrote the US Forest Service, and when they wrote back this is what they said.
“In reviewing your Web Site it appears that your station is programmed or
modeled after a fire danger rating system used in Canada. Federal and
State agencies in this country use the National Fire Danger Rating System
(NFDRS). There are perhaps many reasons why your model does not correlate
well with the NFDRS system.”
While fire danger rateings here are low, my index was saying extreme, and vise versa. Brian this is just a suggestion, but the NFDRS might be a feature addon to the program, instead of trying to figure out FWI for a US location with a foreign index. Complicated i know. I took a look at the equation that they use to come up with this. Wow what a complicated piece of mathmatics. You can not use codes designed for grassland fires in a forested area, or vise versa. I learned that at the outset in the discussion with the National Forest Service. I live in the middle of a national forest, and would like to know what the FWI is exactly for my type of location. Yes i can be complicated, but i was curious. I wrote to the NFS to see if i could use smokey bear from their site. He is always updated, 24/7 based on this area. I haven’t gotten a reply yet. If i can go that route i am going to have to. The current FWI is not designed for my region. If someone comes up with a better way let me know.
I found this USDA Forest Service Riverside (California) Forest Fire Lab site;
Described as “Southern California Fire Weather Index Forecast”
While not correcting, modifying or fixing any data… my FWI.htm file shows the temperature with a degrees C, but displays the value in degrees F…
When it should DISPLAY 97.2 F
The value is correct, the label is not…
While not correcting, modifying or fixing any data.. my FWI.htm file shows the temperature with a degrees C, but displays the value in degrees F..
When it should DISPLAY 97.2 F
The value is correct, the label is not..
Me too. On my web page the FWI displays TEMP(oC) but the value is in oF which is correct. Under wdisplay directory FWI2.txt is the same as the web FWI. Same for FWI.htm in the webfiles directory. However from the main WD page View, Daily Fire Weather Index Data the FWI displays TEMP(oF).
Looks like a glitch for Brian to fix sometime when he gets caught up.
Yep, me too. I had a local forestry FMO (Fire Management Officer) view my weather http://apsn.awcable.com/weather/fwi.htm and comment that I ought to fix the temp label since 80.9 degrees C was a wee bit high! Yes, the value is correct (degrees F) but the label is wrong.
I have the following link in my web page, it’s from the “National Interagency Fire Center” in Boise, iIdaho. It might be of use.
“img src=“http//www.fs.fed.us/land/wfas/fd_cls_f.gif” border=0 ISMAP width=782 height=580 alt=“Fire Danger Forecast”” gives the following updated daily…
ah, i have fixed the units bug, for the next version
22 cows calved now…and the sun was shinng today…for a change