Wildfires can occur in the state of Virginia at any time.
As a result, the fire weather forecast will be issued year-round. However, the
peaks of the fire weather season are as follows:
The annual hunting season also starts in mid-September, which leads to an increased
risk of fire starts.
Note: NWS Sterling does not issue a routine fire weather forecast for northern Virginia
from Dec 15 to Feb 15. NWS Morristown issues a morning forecast year round,
but the afternoon issuance is only from February 15 to May 15.
The FWF provides a detailed prediction of elements for three
specific 12-hour periods (four 12-hour periods with the afternoon
forecast), a general 3 to 7 day forecast, and an 8 to 14 day
extended outlook. The FWF is issued twice daily, once during the
morning (between 3:00 and 6:00 AM), and the other during the
afternoon (between 2:00 and 4:00 PM). The morning forecast, to be
disseminated no later than 8:30 AM, consists of three periods:
"Today" (valid from issuance through 6 PM local time), "Tonight" (6
PM to 6 AM), and "Tomorrow" (6 AM to 6 PM). The afternoon version,
to be disseminated no later than 4:00 PM, consists of four periods:
"Tonight" (6 PM to 6 AM), "Tomorrow" (6 AM to 6 PM), "Tomorrow Night"
(6 PM to 6 AM), and the "Following Day" (6 AM to 6 PM).
Outlook 8 to 14 Days - This section will only include temperature and
precipitation forecasts and will provide forecasts with respect to seasonal normal
values for the specific time of year.
Update Criteria for the Fire Weather Planning Forecast
The
Fire Weather Forecaster will maintain a weather watch to ensure that
the forecast remains accurate. When unexpected changes occur, or are
forecast to occur, which significantly deviate from the previous
forecast, the forecast will be updated. The decision to update, to
an extent, is at forecaster discretion. The update criteria for
various elements are listed in the Appendix. It is a shared
responsibility for the WFO's and the natural resource agencies to
monitor the need to update a forecast. Respective agency personnel
will also provide feedback as to the updating of an FWF, NFDRS
Point, or Spot Forecast.(TOP)
Site Specific Forecasts (Spot Forecasts)
Criteria
Spot forecasts are special, non-routine forecasts prepared upon request
of any federal agency, or state agency when
there is some aspect of federal resources involved and/or
interagency protection agreements currently exist, that needs site
specific weather forecasts for: 1) controlling the spread of
wildfire; 2) planning and managing prescribed fires; or 3) other
specialized forest management activities. In the event of an
emergency which threatens life and/or property, spot forecasts can
also be provided to any federal, state, or local agency.
Spot forecast requests for wildfires and hazardous material emergencies
are considered high priority, and can be obtained at any time. Spot forecasts
may be obtained for prescribed burns; however, the response may be delayed due
to higher priority responsibilities of the forecaster on duty.
Contents
Spot forecasts are highly detailed forecasts for a
specific location within the forecast area. The format of the spot
forecast is specified in National Weather Service Directive 10-401.
The forecasts will be headlined for a Red Flag Warning
or Fire Weather Watch. The forecasts will begin with a
discussion, and may contain any or all of the following weather
elements: sky conditions; maximum and minimum temperatures, minimum
and maximum relative humidity values, wind speed and direction;
probability of precipitation; precipitation type, duration and
amount; mixing heights; transport wind; inversion height; inversion
onset and burnoff times or temperatures; ventilation and smoke
management levels; wind profiles; stability indices (IE., Haines
Index), and lightning activity levels (LAL). Since these are site
specific and can be initiated because of critical circumstances,
tailored products can be requested (e.g. temperature, relative
humidity, and wind speed forecasts on a two hour incremental time
period).
Procedures for Requesting a Spot Forecast
Spot forecasts will be prepared when requested by a user agency.
Federal, state and local agencies may request spot forecasts in
support of wildfire suppression or other emergencies where lives
and/or property may be threatened. Due to the detailed and specific
nature of this forecast product, it is imperative that the user
provide the forecaster with necessary and sufficient information so
that a reliable forecast can be prepared.
Requests for spot forecasts should be made using the web based
spot forecast request form. This form, along with instructions on
how to use it, is available on the local NWS fire weather web pages.
The web based spot forecast
request form should be filled out as completely as possible
(required parameters are listed in red) by the user agency prior to
submitting the request. Use Latitude/Longitude for your location, and this
should be entered in either decimal degrees, or degrees/minutes/seconds. If
you are using decimal degrees enter as standard (e.g. 37.52).
If degrees/minutes/seconds, use a second decimal (e.g. 37.31.12),
or leave a space between each number (e.g. 37 31 12).
Direct links to the spot monitor page for each NWS office:
NWS Blacksburg - http://spot.nws.noaa.gov/cgi-bin/spot/spotmon?site=rnk
NWS Charleston - http://spot.nws.noaa.gov/cgi-bin/spot/spotmon?site=rlx
NWS Morristown - http://spot.nws.noaa.gov/cgi-bin/spot/spotmon?site=mrx
NWS Sterling - http://spot.nws.noaa.gov/cgi-bin/spot/spotmon?site=lwx
NWS Wakefield - http://spot.nws.noaa.gov/cgi-bin/spot/spotmon?site=akq
In times when internet
access is hindered or not possible, spot forecasts may be requested
and disseminated via fax or phone. If faxing a request, users should
use the Fire Weather Special Forecast Request Form, WS Form
D-1. Section I of WS Form D-1 should be filled out as
completely as possible by the user agency prior to submitting the
request by the fax to the forecast office. If the request is made by
phone, all information in Section I should be provided to the
forecast office.
While there is no dedicated fire weather forecaster, the forecast
office will give a high priority to spot forecasts in the absence of
weather phenomena in the CWA that pose a threat to life and
property. To ensure that the request for a spot forecast is handled
properly and appropriately, users should adhere to the following
guidelines:
1) Allow adequate time for the forecaster to prepare the
forecast. This will normally be about 30 minutes. On
particularly busy fire weather days, spot forecasts will be handled
on a first-come, first-serve basis, with wildfires or other life
threatening events taking the highest priority.
2) Provide as much on-site or near-site weather information as
possible. At a minimum, the user should provide at least one
observation within an hour of the request. This observation must
contain the following: location of the observation; elevation at the
observation site; time of the observation; wind direction, speed,
and level (eye or 20 foot); dry and wet bulb temperatures; any
remarks about the state of the weather, particularly anything that
may affect fire behavior. If possible, include some observations
from the previous day that might give the forecaster an indication
of daily trends.
3) As much as possible, specify the time period for which the
forecast is needed.
4) As much as possible, specify the weather elements of most
importance for which a forecast is needed, and/or critical values of
these elements.
5) Provide a contact point name and phone number where the
forecaster can call back, if necessary. (Also include a fax number
for returning completed forecasts if the web based spot forecast
form is not used).
6) In order to receive prompt attention for a fax request, please
phone the office to let the forecaster know the request is on the
way.
7) Natural resource agency personnel should contact the
NWS forecast office for a spot update if the forecast
conditions appear unrepresentative of the actual weather conditions.
Whenever possible, users should provide feedback, positive or
negative, to the NWS forecast office concerning the performance of
the spot forecast during or shortly after an event. This will assist
forecasters in subsequent forecasts for the same or similar
conditions.
(TOP)
National Fire Danger Rating System (NFDRS) Forecasts
Issuance
NFDRS forecasts will be issued for any
predetermined site from which an NFDRS observation is received,
provided the observation is received on time, is complete, and is
deemed accurate. The natural resource agencies will determine which
observation sites (normally RAWS sites) will be NFDRS sites.
Initiation of NFDRS forecasts for a new site will be coordinated
with the NWS, and the agency requesting new NFDRS service will
provide the NWS with information about the site location. Forecasts
will not be provided for sites with bad data. The NWS will notify
the owner agency when bad data is received from a RAWS station.
In the state of Virginia there are 11 NFDRS RAWS.
Four are in the Blacksburg service area:
Station ID | Name | County | Elevation | Site Latitude | Longitude
449906 | Chincoteague USFS/NWR | Accomack | 5 ft | 37.99N | 75.29W
Contents
The NFDRS forecast will be a forecast of the next day observation
at 1300 LT. The format of the NFDRS forecast is specified in
National Weather Service Directive 10-401. The forecast will include
the following elements:
a. ZONE/FCST: Shows whether this forecast is for an NFDRS zone or
individual station. Zone average trends are forecast when enough
observation are available for the zone area. Individual site
forecasts are done where only a few observation are available.
b. NO: NFDRS Zone Number (or individual NFDRS site number).
c. YYMMDD: Year, month and day of valid forecast time.
d. 13: Valid forecast time. Always 1300 LST.
e. WX: Weather valid at 1300 LST tomorrow. Valid entries are:
0 = clear
1 = scattered clouds (1/8 to 4/8)
2 = broken clouds (5/8 to 7/8)
3 = overcast clouds (more than 7/8)
4 = fog
5 = drizzle
6 = rain
7 = snow or sleet
8 = showers (in sight or at the station)
9 = thunderstorm
(Categories 5, 6 or 7 sets NFDRS index to 0)
f. TEMP: Temperature in degrees F valid at 1300 LST (or
temperature trend + or - degrees F).
g. RH: Relative Humidity in percent valid at 1300 LST (or RH
trend + or - percent).
h. LAL1: Lightning Activity Level 1400 LST to 2300 LST.
i. LAL2: Lightning Activity Level 2300 LST to 2300 LST.
j. WDIR: Wind Direction. Used only for point forecast (FCST)
version. Enter direction using sixteen point compass (N, NNE, NE,
ENE, etc.) valid at 1300 LST (20 ft level, 10 minute average).
k. WSPD: Wind Speed. Enter wind speed in mph (or wind speed trend
+ or - mph) valid at 1300 LST (20 ft, 10 minute average).
l. 10HR: 10 hour timelag fuel moisture in percent valid at 1300
LST (or trend + or - percent).
m. Tx: Maximum temperature from 1300 LST to 1300 LST
tomorrow.
n. Tn: Minimum temperature from 1300 LST to 1300 LST
tomorrow.
o. RHx: Maximum relative humidity from 1300 LST to 1300 LST
tomorrow.
p. RHn: Minimum relative humidity from 1300 LST to 1300 LST
tomorrow.
q. PD1: Precipitation duration in hours 1300 LST to 0500 LST.
r. PD 2: Precipitation duration in hours 0500 LST to 1300
LST.
s. WETFLAG: Y or N. Indicates whether liquid water will be on the
fuels at 1300 LST tomorrow. (Use with caution. A "Y" will set all
the NFDRS indices to zero!).
Format. The NFDRS Forecast will follow the comma delimited format
as shown:
ZONE,NO,YYMMDD,13,WX,TEMP,RH,LAL1,LAL2,WSPD,10HR,TX,TN,RHx,RHn,PD1,PD2,WETFLAG
FCST,NO,YYMMDD,13,WX,TEMP,RH,LAL1,LAL2,WDIR,WSPD,10HR,TX,TN,RHx,RHn,PD1,PD2,WETFLAG
Procedures
The land management agencies are responsible for taking, quality
controlling, transmitting and archiving the NFDRS observations.
Observation must be received at the NWS in a timely manner.
Forecasts will only be prepared for predetermined sites, and only
from those sites for which an observation has been received.
The deadline for the land management agency for transmitting the
observation is 1900 GMT (2:00 PM EST or 3:00 PM EDT). The NWS
will prepare and transmit the NFDRS forecasts no later than 1945 GMT
(2:45 PM EST or 3:45 PM EDT).
Although the data cutoff time for ingest into the NFDRS software is
7 PM, preliminary calculations based on the forecast are used by the
land managers to make staffing decisions at shift briefing time (4
PM).
(TOP)
Fire Weather Watch and Red Flag Programs
During periods in which critical fire weather conditions are
expected or imminent, the NWS will issue statements, watches and
warnings to describe the level of urgency to the appropriate user
agencies. These issuances will be coordinated with natural resource
agencies.
Definition of a Red Flag Event
A Red Flag Event occurs when critical weather
conditions develop which could lead to extensive
wildfire occurrence or to extreme fire behavior. Red Flag Events
represent a threat to life and property, and may adversely impact
fire fighting personnel and resources. Critical weather conditions
include combinations of the following: strong, gusty winds; very low
relative humidity; high to extreme fire danger (very low fuel moisture).
Historically, the highest risk of significant fire starts
and blow-ups occur when fuels are sufficiently dry and dry cold fronts pass over the region. Dry cold
fronts typically cause lower humidity levels and produce shifting and increasing wind. In an effort to
simplify the Red Flag Warning process, forecasters at the NWS offices will mainly be concerned with the
specific weather conditions and critical weather patterns necessary to produce Red Flag conditions.
Tracking fuel moisture will be the responsibility of the fire product user agencies. **As a result,
coordination will be necessary with the Virginia Interagency Coordination Center (VICC) and the Regional
Fire Management Office in Roanoke, Virginia, when a NWS forecaster considers a Red Flag Warning or Fire
Weather Watch. **
Generally, a Red Flag Warning will be issued when:
* Ten-hour fuel moistures are observed or expected to be 7 percent or less.
This is an
essential requirement and should be coordinated with the Fire Management Officer at the Regional USFS office,
or the Virginia Interagency Coordination Center. In the event coordination is not possible, the forecaster may,
at his or her discretion, use the fuel moisture readings from the NFDRS RAWS.
-AND-
* Relative humidity is expected to fall below 30 percent at any time over
the forecast area and sustained wind of 20 mph or more. The sustained wind will be a two-minute averaged,
20 foot-level wind forecast.
During periods of extended drought or when wildland fires are occurring, modifications to these criteria may be required.
Any change will be coordinated through the Virginia Interagency Coordination Center, or with the Fire Burn Analyst (FBAN)
and Incident Commander (IC) on an existing large project burn. We recognize there are seasonal variabilities that may
stress live fuels differently, in addition to other weather phenomena (such as, a frontal passage or thunderstorm downburst),
that may result in extreme fire behavior and pose a hazard to wildland firefighters.
Red Flag Warning
A Red Flag Warning will be issued, after
coordination with the appropriate natural resource agencies, when a
Red Flag Event is occurring or is imminent. The warning will be
issued for all or a portion of the forecast area. It will be issued
immediately once the forecaster and the appropriate natural resource
agency have determined that a Red Flag Event is ongoing. Otherwise,
it shall be issued for impending Red Flag conditions when there is a
high degree of confidence that conditions will develop within 24
hours. The warning will continue until the conditions cease to exist
or fail to develop as forecast. At such time, the warning will be
canceled. The format of the Red Flag Warning is specified in
National Weather Service Directive 10-401. A sample Red Flag
Warning is in the Appendix.
Fire Weather Watch
A Fire Weather Watch will be issued,
after coordination with the appropriate natural resource agencies,
to advise of the possible development of a Red Flag Event in the
near future. It will be issued for all or part of the forecast area.
A Fire Weather Watch is issued when the forecaster and appropriate
natural resource agencies are reasonably confident that a Red Flag
Event will occur. A watch should be issued 12 to 48 hours in advance
of, but not more 72 hours in advance of, the expected onset of
the critical weather conditions. The watch will remain in effect
until either it is determined the Red Flag Event will not develop,
or that the watch should be upgraded to a warning. If conditions are
not expected to occur as forecast, the watch will be canceled. The
format of the Fire Weather Watch is specified in National Weather
Service Directive 10-401.
Fire Danger Statements and Blow-Up Alerts
When fire danger
or fire occurrence is high and is coupled with critical weather
conditions, user agencies may request that the NWS issue a Fire
Danger Statement or Blowup Alert. These statements will be issued in
coordination with the requesting agency and will only be issued with
their approval. The NWS will use the Special Weather Statement (SPS)
for these issuances.
Participation in Interagency Groups
At a minimum, one NWS representative (usually the State Liaison
WFO Fire Weather Program Leader or MIC) will attend the State
Interagency meetings or working groups where fire weather or smoke
management policy is discussed as an integral part of the meeting.
However, it is strongly recommended that all NWS offices with fire
weather responsibility attend the meetings to ensure uniform
representation.
Special fire weather services are those services that are
uniquely required by natural resource agencies and go beyond the
normal forecast operations of the NWS. Special services include
Incident Meteorologist (IMET) deployment, station visits, training,
and other pertinent meteorological services that are designated as
non-routine.
Typically, special services require NWS personnel to be away from
the Forecast Office and, in some instances, be in overtime status.
User agencies are responsible for covering the cost of NWS overtime,
travel and per diem expenses. Reimbursement of costs for special
services will be as outlined in the Interagency
Agreement for Meteorological Services.
Incident Support
On-site forecast service support is available for wildfires and
prescribed burns. This includes the deployment of an Incident
Meteorologist (IMET) and related service equipment such as the
Advanced Technology Meteorological Unit (ATMU), the All Hazards
Meteorological Response System (AMRS), and the Fire Remote Automated
Weather Station (Fire RAWS). The IMET, ATMU, AMRS, and the Fire RAWS
are considered national fire fighting resources, and can be
requested through the Virginia Interagency Coordination
Center.
The ATMU and AMRS are modularized and mobile systems of equipment
used by an Incident Meteorologist (IMET) for data collection and
forecast preparation. Only trained personnel will operate the ATMU
and AMRS, and this service equipment will only be dispatched to an
incident when a certified IMET is requested. The IMET is responsible
for ordering and arranging shipment for the ATMU and AMRS.
There are 25 ATMUs cached across the country, mostly in the
western states. The nearest ATMU
cache to the state of Virginia is London, KY, where
two are maintained. AMRS
workstations are also pre-positioned across the country,
most of which are collocated with existing Weather Forecast Offices
that contain certified IMETS. These AMRS workstations are maintained
by the IMETS and are typically shipped with the IMET being
mobilized.
The ATMU is composed of one large shipping box consisting of a
theodolite with tripod, a belt weather kit, PIBAL weather balloons,
a nozzle and regulator for a helium tank, and office supplies and
miscellaneous expendables. Its volume is 13.8 cubic feet and it
weighs 122 pounds.
The AMRS is also composed of one large shipping box, and contains
a laptop computer, a satellite dish for obtaining weather data, and
a printer. The volume of the satellite dish is 13.8 cubic feet, and
its weight is 122 pounds.
Total weight of the ATMU and AMRS is 244 lbs with a volume of
27.6 cubic feet. The cubic feet are necessary for shipment by air.
The same specification shown is listed in the user agencies'
National Mobilization Guide.
Requests for the ATMU, AMRS, and IMET should be made through the
Virginia Interagency Coordination Center. Typically, the IMET
nearest the incident will be deployed. However, during times of
limited resources, IMETs from other areas of the country may be
called. The decision will be made by the Special Meteorologist to
NIFC (SMC) in conjunction with the MIC and IMET from the affected
offices. It is the responsibility of the IMET to arrange shipment of
the AMRS workstation.
The success of the operation depends in part on the user agency
providing shelter and logistical support. Prior to the use of this
equipment, the IMET is expected to have coordinated with the local
user agency to ensure proper field support. If an IMET determines
that an ATMU and/or Fire RAWS is desirable, it is the IMET's
responsibility to ensure the ATMU and Fire RAWS have also been
ordered for the incident.
The requesting agency is responsible for any storage of service
equipment while in transit, and shelter for the IMET and service
equipment at the site. A sheltered work area, of at least 50 square
feet with a table and chair, must be protected from excessive dust,
free of standing water or condensation, and must be heated and/or
cooled sufficiently to allow efficient operation of equipment. Power
(120V AC) must be provided for the AMRS's electrical equipment, and
priority telephone access during certain short periods each day must
be made available.
The procedure for requesting IMETs will follow the guidelines
outlined in the national MOA, the National Mobilization Guide, and
the Southern Area Interagency Mobilization Guide. The following
information will be provided to the requested IMET:
1. Name of fire.
2. Location of fire.
3. Directions to location where the IMET is to report and the
location of ICP.
4. Name of Incident Commander, Plans Chief, and FBAN, if
available.
5. Request and Resource Order number for IMET.
Upon arrival at the incident and after going through the
appropriate check-in procedures, the IMET will:
- Brief the Fire Behavior Analyst (FBAN), Planning Section Chief
(PSC), and the Incident Commander (IC) on current and expected
weather as it affects the fire.
- Establish a schedule with the IC and the FBAN for written
forecasts and formal briefings.
- Request a briefing of the fire situation and potential
behavior problems from the FBAN. As time and resources permit,
incident management should arrange for an aerial inspection trip
for the meteorologist and should provide the forecaster with
current fireline maps. If possible, the IMET should be assigned a
radio with the fireline frequency.
- Arrange for a schedule of observations from key points around
the fire and from nearby lookouts and fire danger stations, in
cooperation with the FBAN and PSC. On large fires, some personnel
(at least two) should be permanently assigned to this duty. On
smaller fires, this information can be provided by Division
Supervisors equipped with belt weather kits.
IMET duties will vary with incident management team requirements,
but the IMET is expected to provide daily weather forecasts for the
incident, participate in shift briefings, planning and strategy
meeting, and coordinate daily with the local Weather Forecast Office
(WFO) and /or other IMETs at nearby incidents.
Demobilization is initiated at the incident, and will be
coordinated through the Virginia Interagency Coordination
Center. Upon release, the user agency will transport the ATMU and
Fire RAWS back to its cache location or to the controlling fire
weather office. Travel arrangements will be made for the IMET back
to his or her home office. The IMET is responsible for transporting
the AMRS workstation back to the home office. If the AMRS unit
resides at a different location than the IMET, the IMET must make
arrangements to ship the equipment to the proper office, and charge
any shipping cost to the fire.
Other Special Services
Other special services may include weather station visits by
partner agency personnel, RAWS site surveys and inspections, weather
observer training, and course development work or related program
work. These activities would typically be at the full expense of the
requesting agency unless other arrangements have been made.
NWS meteorologists may also be asked to assist in other
non-routine services (e.g. briefings or coordination calls) during
periods of high fire danger or fire occurrence. MICs and Fire
Program Leaders are to ensure the natural resource agency needs are
met with little expense to either agency.
(TOP)
NWS meteorologists will be available to assist in user-oriented
training. This includes fire behavior courses, such as S-190 and
S-290, where the meteorologist will serve as part of the cadre for
that course. Requests for training assistance should be made through
the NWS office's Fire Weather Program Leader or
Meteorologist-in-Charge (MIC). Sufficient advance notice should be
given to allow for scheduling and proper preparation. Costs incurred
by the NWS in providing training assistance will be borne by the
requesting agency.
(TOP)
