**[I. STANDARDS FOR SITING NFDRS WEATHER STATIONS:]{.underline}**

Weather stations used for National Fire Danger Rating System (NFDRS)
purposes should be located in places that follow the standards set in
PMS 426-3 "NFDRS Weather Station Standards". This would mean they are
placed in "average worst-case" type locations. The documentation defines
this as south to west aspects in the lower to mid-slope range of the
area being represented. Other documentation related to the subject
includes PMS 426-2, the "NWCG Weather Station Handbook -- an IA Guide
for Wildland Managers", and "USFS Region 5 Supplement 5125.12, Weather
Station Networks". Consistent with all of these guidelines, stations
that are truly useful for Fire Danger Rating are those sited where they
portray well the representative weather, topography and fuels of the
fire problem area. Lastly, NFDRS standards require everything be
automated by the close of 2005. If a station is not a RAWS, on GOES,
with solar radiation etc., then it won't be NFDRS compliant.

**[II. ADDITION OF NEW RAWS STATIONS TO AN OBSERVING
NETWORK]{.underline}:**

In the past 25 years many RAWS stations have been placed in operation on
the nation's forests and rangelands. A large share of these are used for
Fire Danger rating, though the majority also serve other purposes. One
key reason for adding new stations is to increase the spatial density of
weather observing networks. Another is to increase the elevation range
covered in mountainous terrain. The goal is to get a good mix of weather
observations from both above and below the typical terrain-induced
atmospheric inversions in the area. Even where old manual stations have
been properly sited and have provided years to decades of good weather
observations, RAWS stations are often added to enhance the total weather
coverage across a unit. Among the other advantages of RAWS technology
are these:

-   Continuous coverage (24-7) of the weather, not just one observation
    (or a few) per day

-   Stations can be placed in sites that are 'more remote' than manual
    stations typically have been. These are often more representative of
    the fire problem.

-   Staff time saved because a person doesn't physically have to take
    the observation each day

-   Often staff can be too busy to take manual 1300 observations, and
    the opportunity is lost for the day. With a RAWS, observations are
    taken continuously and available real time or later for appropriate
    NFDRS processing in WIMS.

-   The NFDRS observations from RAWS are truly [taken at the same time
    each day]{.underline}, which enhances the consistency and
    reliability of the database

-   Electronic format of data collection expedites its processing, and
    availability for program applications, spreadsheets, etc.

**[III. CONSIDERATIONS BEFORE MOVING EXISTING STATIONS TO NEW
SITES:]{.underline}**

There are numerous factors to consider regarding the move of an existing
NFDRS weather station to an alternate site. The decision should not be
made lightly, particularly for stations that have a long history. After
all, **it takes 20 years** to collect 20 years of weather observations
-- this is

by no means a small accomplishment. Nor should the decision to move a
station be made in a vacuum. RAWS stations are not inexpensive, and in
this era of tighter fiscal oversight [many stations are used for
multiple resource management purposes]{.underline}. You should never be
moving stations on a whim, or without any good forethought, or without
the input of others who might be utilizing data from the site. In most
cases, the thoughtful siting for multiple objectives should not lead to
any degradation in NFDRS-based decision making.

Fire danger rating is a rather coarse endeavor, using point source data
to represent large areas. If the expected improvement from a proposed
new site will be minor (say, just 10%), then a station move for strictly
NFDRS reasons is not justified. This is because the resulting weather
observations aren't likely to yield [significant]{.underline}
differences in the end-result indices or adjectives of the NFDRS system.
On the other hand, moving that same station [might have adverse
effects]{.underline} on other users of the RAWS data, such as
hydrologists, climatologists, silvaculturalists, etc. They might have
ongoing, long-term studies or projects that utilize the data from the
existing site.

One question that arises in planning is that of tradeoffs. Does the
benefit of a having a good, new station location outweigh the loss of a
long-term daily data stream from the old site? In some cases, the answer
may be "yes". Even if a station has a long history, if it hasn't proven
to be very representative of the Danger Rating area, there may be no
advantage in continuing data collection at that site. Station owners are
encouraged to move the station to a better site, and thereby begin
building a new more-representative and pertinent weather database. The
data from the previous site will still be available.

**Questions that should be asked when addressing a possible station move
include these:**

-   Does the existing station truly meet the standards of NFDRS, or does
    it perhaps just measure a local microclimate, due to less-than-ideal
    siting?

-   How long is the data stream from the existing site, and of what
    quality is it?

-   What is the primary objective to be met by moving the station?

-   If it is determined that the existing station doesn't meet PMS 426-3
    Standards, will the proposed move bring the station in line with
    those standards?

-   Has a fire weather meteorologist been consulted for input and
    assistance?

-   If the move is primarily for the improvement of fire danger rating,
    what data supports the new site as being likely to **yield a
    significant improvement** in NFDRS-related decision making?

-   Have the locations of your neighboring unit's existing RAWS been
    considered in the planning for your station move, i.e. have you
    looked at the "big picture"?

-   Have those users of the RAWS data for [other than for NFDRS
    purposes]{.underline} been queried for their input regarding a
    station move?

-   Have comparisons been made between the existing and new sites
    regarding logistical factors such as wintertime access, site
    security, potential power sources, etc?

-   How do the current site and the proposed new site compare regarding
    the ease of limiting vegetative growth around the RAWS station?

There are of course, other questions that you might need to address on a
case-by-case basis.

**[IV. DECIDING WHEN A NEW WIMS ID IS NEEDED:]{.underline}**

When dealing with an NFDRS station move or the addition of a new
station, there are basically three options regarding WIMS IDs: 1) you
definitely need a new ID number 2) you do not need a new ID number, or
3) it's a judgment call, and there are guidelines that can help you
decide.

1\) The following are examples of situations in which you definitely
[**would need** a new WIMS ID]{.underline}:

-   A [new weather station]{.underline} is being placed at a [new
    site.]{.underline}

-   An [existing station]{.underline} is being [moved to a
    much-different site]{.underline}. That is, there are significant
    changes in one or more of the following: elevation, aspect, distance
    from previous site, fuel

> model, or drainage the station is in. When you make this type of
> station move, change the station metadata. If you do not change the
> station [name]{.underline}, make remarks linking the station's new
> WIMS ID to the previous ID, and tell what factors that necessitated
> the change.

-   The surroundings (site characteristics) of an existing station
    change greatly, altering the site's weather in some way. (E.g. when
    a barracks with a brown wall was erected right near an existing
    station, afternoon temperatures shot up 20º F.

-   A permanent RAWS is being placed where a temporary portable RAWS had
    been used for testing or comparison purposes (whenever possible,
    move any archived data from the period of the test/ temporary RAWS
    into the new permanent station's data base)

-   You discover that the ID you've been using (hopefully not for very
    long) has been used by another station. That is, another database
    exists that uses the same WIMS ID for a different site. This
    situation will quickly lead to confusion, if not corrected.

2\) Examples in which you [**would not need** a new WIMS
ID]{.underline}:

-   A new RAWS station simply [replaces]{.underline} a previous manual
    station [at that same site]{.underline}. (You do, however need to
    document the change in WIMS and ASCADS. Leave good tracks that won't
    get trash-canned in a cleaning frenzy down the road).

-   When the move to a new site is insignificant, involving very short
    distances, without change in aspect, slope, drainage etc. This is a
    judgment call, but usually a new station number is not used. But
    again, the minor site change should be thoroughly documented.

-   You change the **name** of a station, but nothing else is changed.
    The same ID number can be affiliated with both the old and new
    station names. Just make sure to document the changes in WIMS and
    ASCADS, explaining the situation.

3\) When getting [a new WIMS ID is **not a clear-cut
decision**]{.underline}, i.e. case-by-case judgment calls:

When a new station replaces an old one at a nearby location it becomes a
judgment call as to whether a new ID is needed. Perhaps a new number
will be desired, even when not necessary. These types of decisions
should be made on a case-by-case basis. The best methodology on which to
base the decision is to collect weather from the new and old sites
simultaneously for a year, or at least for the entire fire season, and
see how they correlate in all types of weather patterns. If the weather
from the two sites tracks together very closely, you may want to keep
using the existing station number. The station's historical weather
record and the new data stream can be joined, with notations in the
Station history of what minor changes occurred, and when. If the weather
differs, you will want to use a new WIMS ID.

If an NFDRS station is moved because **its weather and/or site
characteristics have proven** **unrepresentative** of the unit's fire
problem, then of course there is no necessity that a new site should
have similar weather. You will be selecting a different type of site,
one where the observed weather **does** represent the weather that
drives the unit's fire problems. The new site could be significantly
different from the prior location.

Sometimes even when a site has proven useful for NFDRS, a move of the
station may be deemed necessary for [reasons unrelated to its
weather]{.underline} (e.g. logistical reasons or site-ownership issues).
In a case like this there might be a strong desire to keep the same
station number, motivating a search for a nearby site with very similar
weather, precipitation, elevation, and aspect. The hope would be to
preserve the usefulness of long-term records and statistics that have
been gathered.

Finally, whether moving a station, locating a new station, or assessing
the validity of an existing station, the station owner should always
employ the assistance of individuals trained in RAWS technology, the
National Fire Danger Rating System, and of an experienced fire weather
meteorologist (either a fire weather meteorologist from the NWS or the
GACC). A mandatory approval by a fire weather meteorologist is required
for all new or moved NFDRS stations.

(Version: 11/18/2005)