Space WX Alerts: CONTINUED ALERT:  Electron 2MeV Integral Flux exceeded 1000pfu ( Latest Alert ) - Issue Time: 2018 Mar 23 2102 UTC
Radar Local Radar 36.1°F  95% CBI: -2 Chandler Burning Index Description Fire Weather Index icons
Live FWI: 0.5
Fire Weather Index icons
Live FWI10: 0.6
Current Conditions for Foresthill, CA.
Updated3/24/18  8:51am
Current Fire Danger

Fire locations are based on data provided by the National Interagency Coordination Center and are subject to change.

Move your mouse over the fire indicators to see additional information.

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KMZ File
'MOHAWK' - 427.0 acres 'FRONTIER' - 700.0 acres 'STATELINE' - 28105.0 acres 'COLORADO STREET' - 400.0 acres 'BEGS' - 2500.0 acres 'COUNTY LINE' - 15682.0 acres 'CHANNING' - 4500.0 acres 'OLD MUDDY RD' - 4480.0 acres 'GRAVEL PIT' - 2976.0 acres 'NINTH AVENUE' - 400.0 acres 'SPRINGS RANCH' - 614.0 acres 'MERRITT' - 1466.0 acres 'COTTON BALE' - 450.0 acres 'CIMARRON' - 450.0 acres 'MAPLE' - 1676.0 acres 'RICE COUNTY' - 8000.0 acres 'TEXACO ROAD' - 759.0 acres 'CONVICT HILL' - 1300.0 acres 'ROCKY HILL ROAD' - 180.0 acres 'FOOT BRIDGE' - 301.0 acres 'HENRY' - 1134.0 acres 'BOAR CREEK' - 1068.0 acres 'BIGGY' - 10816.0 acres 'TRENTMAN' - 4300.0 acres 'BREWSTER' - 2000.0 acres 'FLYING G' - 1800.0 acres 'CIRCLE K' - 1175.0 acres 'ATOKA LAKE' - 300.0 acres 'BEGGS' - 200.0 acres 'NORTH BOGGY CREEK' - 780.0 acres 'GRAVEYARD HILL' - 793.0 acres 'WESLEY' - 1200.0 acres 'DEERTE' - 2050.0 acres 'PIPELINE RD' - 900.0 acres 'BLUE CREEK #2' - 1728.0 acres 'ROCKPEN' - 858.0 acres 'SOUTH BOAT RAMP' - 102.0 acres 'SANDYLAND' - 175.0 acres 'WILD HORSE' - 325.0 acres 'PETERSON CREEK' - 890.0 acres 'CUPCO SOUTH' - 120.0 acres 'BURRIS VALLEY' - 1125.0 acres 'ROCKY RIDGE' - 300.0 acres 'EAST CUPCO' - 717.0 acres 'CEMENT MIXER' - 155.0 acres 'RED PASTURE' - 566.0 acres 'COFFEY RIDGE' - 800.0 acres 'CLEORA' - 400.0 acres 'MCGEE' - 150.0 acres 'JOINT' - 210.0 acres 'BLUE BRANCH' - 444.0 acres 'AL PETTY COMPLEX' - 180.0 acres 'LITTLE EAGLE CREEK' - 542.0 acres 'HIDDEN CREEK RD' - 330.0 acres 'COWSKIN RIDGE' - 318.0 acres 'RIDGETOP RD' - 560.0 acres 'ROGERS' - 112.0 acres 'PALERMO' - 250.0 acres 'BOGUS RIDGE' - 816.0 acres 'SURPRISE 1' - 750.0 acres 'RAVENDEN' - 226.0 acres 'JUNALUSKA 2' - 300.0 acres 'UPPER HILLSBOROUGH' - 330.0 acres 'FLAG POND' - 1600.0 acres 'FAKA-UNION (11)' - 10446.0 acres 'MINI RANCH RD (28)' - 300.0 acres 'ANHINGA' - 3119.0 acres 'W BOUNDARY RD (26)' - 950.0 acres 'FOUR WINDS (43)' - 150.0 acres 'SUNNY B (31)' - 381.0 acres 'CALESTOWN' - 617.0 acres 'CUMBEE' - 1630.0 acres
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Fire Information - National Fire News

Northern California Preparedness Level 1  

National Preparedness Level 1  

National Preparedness Level Updated December 20 at 12:00 pm MDT (on a scale from 1 to 5)

March 16, 2018

Nationally, 48 large fires were reported this week, mostly in the Southern Area. Twenty-seven large fires are burning in five states. Firefighters were able to contain 32 large fires since March 9.

National Weather:
A pair of cool, moist systems will impact the West Coast and central Great Plains Friday with wetting precipitation. Additional mountain snowfall is expected across the Southern Cascades and Sierras. To the south, critical fire weather conditions are possible across portions of eastern New Mexico, southeastern Colorado, and the panhandle regions of Texas and Oklahoma as gusty west winds interact with low humidities. By late Saturday, both systems will weaken as they move east and should fall apart; however, showery conditions will continue across the Pacific Northwest and the Northern Rockies. A warming trend will ensue across the West Monday and Tuesday as a high pressure ridge strengthens just west of the Rocky Mountain Crest and pushes temperatures back to near average levels. Model data suggests that significant, widespread wetting rainfall will be possible Wednesday and Thursday across most of the West as a moist system approaches the California Coast and moves on shore into Southern California and Arizona on Thursday. Prior to the system’s arrival, a period of very critical fire weather conditions will be possible across the southern Great Plains on Wednesday as high winds and very low humidities develop out ahead of the system. In Alaska, a pair of weakening cold fronts will move east across the Interior bringing additional light to moderate snowfall through the weekend. A drier southwesterly flow will develop by Monday and Tuesday. Look for a slight cool down mid-week as the flow becomes more northwesterly in response to a strengthening ridge over the Aleutians and eastern Siberia.

Local Weather: Saturday, March 24, 2018 - 3:15am PDT
 InciWeb California Incidents  InciWeb National Incidents

Experimental Hourly Fire Danger

Entire California  | Northern California  | Central California  | Southern California

Lightning Ignited Fires

National Interagency Fire Center statistics show that in 2002-2006, an average of 12,000 (16%) of the wildland fires were started by lightning per year. These fires burned an average of 5.2 million acres per year.

   Two-thirds of lightning fires occur June-August. lightning fires peak in the late afternoon and early evening. Three-fifths (61%) of all fires started by lightning occurred between 2:00 and 10:00 p.m.

   55% of lightning fires occur outdoors, and 41% occur in structures. Deaths and injuries occur mostly in structures (89% and 86%, respectively).

   Because most lightning fires occur outdoors, the most prominent form of material ignited is "growing living form," which includes trees, brush, and grass. Materials found on residential structures that are commonly ignited include roofs, sidewalls, and framing. Electrical wiring is another material often ignited, as the electrical current in lightning is drawn to electrical wires.

   Civilians suffer more injuries than fatalities in lightning fires each year. Most casualties result from lightning structure fires rather than outside or other types of lightning fires. 89% of lightning fire civilian fatalities and 86% of injuries occur in structure fires.

Lightning Probability Forecast Maps

Thunderstrom Potential
Thunderstrom Potential
(click to enlarge)
Thunderstorm Probability
Current Lightning Efficiency Map
(click to enlarge)

Lightning Ignition Efficiency

Lightning fires are started by strikes to ground that have a component called a continuing current. All positive discharges have a continuing current, and about 20% of negative discharges have one. Ignition depends on the duration of the current and the kind of fuel the lightning hits. Ignition in fuels with long and medium length needle cast, such as Ponderosa pine and Lodgepole pine, depend on the fuel moisture. Ignitions in short- needled species, such as Douglas fir depend far more on the depth of the duff layer than on the moisture. Spread of the fire after ignition usually depends on fuel moisture in all cases.

The ignition efficiency on a 1 km pixel is given on a per discharge basis. That is, if the efficiency is high, then about 9 discharges will result in one ignition; if the efficiency is extreme, about 5 or fewer discharges will result in an ignition. The ratio of positive and negative discharges is built into the calculation. (Latham and Schlieter 1989) document the algorithm.

The fuel type and depth are conversions of the 1 km resolution current cover type (Hardy and others 1999) for this specific calculation. The moisture input is the 100-hr dead fuel moisture.

August 2002 - The lightning ignition efficiency algorithm has been corrected due to discovery of an error. The resulting maps reflect higher lightning efficiency than previously.

Current Lightning Efficiency Map
Current Lightning Efficiency Map

Haines Index (Wildfire Potential)

Haines (1988) developed the Lower Atmosphere Stability Index, or Haines Index, for fire weather use. It is used to indicate the potential for wildfire growth by measuring the stability and dryness of the air over a fire. It is calculated by combining the stability and moisture content of the lower atmosphere into a number that correlates well with large fire growth. The stability term is determined by the temperature difference between two atmospheric layers; the moisture term is determined by the temperature and dew point difference. This index has been shown to be correlated with large fire growth on initiating and existing fires where surface winds do not dominate fire behavior.

Haines Index is computed from the morning (12Z) soundings from RAOB stations across North America.

The Haines Index can range between 2 and 6. The drier and more unstable the lower atmosphere is, the higher the index.

  • 2 : Very Low Potential -- (Moist Stable Lower Atmosphere)
  • 3 : Very Low Potential
  • 4 : Low Potential
  • 5 : Moderate Potential
  • 6 : High Potential ------ (Dry Unstable Lower Atmosphere)
Current Haines Index Map
Haines Index Map

Fire Danger Maps

Each day during the fire season, national maps of selected fire weather and fire danger components of the National Fire Danger Rating System are produced by the Wildland Fire Assessment System (WFAS-MAPS), located at the USDA Forest Service Rocky Mountain Research Station in Missoula, Montana.

Current Observed Fire Danger Map
Observed Fire Danger Map
Current Forecast Fire Danger Map
Forecast Fire Danger Map
Current Observed Relative Humidity
Observed Relative Humidity
Current Observed Dew Point Levels
Observed Dew Point Levels
Current Observed Temperature
Observed Temperature
Forcast Wind Speed
Forcast Wind Speed

Keetch-Byram Drought Index

  Keetch and Byram (1968) designed a drought index specifically for fire potential assessment. It is a number representing the net effect of evapotranspiration and precipitation in producing cumulative moisture deficiency in deep duff and upper soil layers. It is a continuous index, relating to the flammability of organic material in the ground.

  The KBDI attempts to measure the amount of precipitation necessary to return the soil to full field capacity.

It is a closed system ranging from 0 to 800 units and represents a moisture regime from 0 to 8 inches of water through the soil layer. At 8 inches of water, the KBDI assumes saturation. Zero is the point of no moisture deficiency and 800 is the maximum drought that is possible. At any point along the scale, the index number indicates the amount of net rainfall that is required to reduce the index to zero, or saturation.

  The inputs for KBDI are weather station latitude, mean annual precipitation, maximum dry bulb temperature, and the last 24 hours of rainfall. Reduction in drought occurs only when rainfall exceeds 0.20 inch (called net rainfall). The computational steps involve reducing the drought index by the net rain amount and increasing the drought index by a drought factor.

Current - Keetch-Byram Drought Index
Keetch-Byram Drought Index


  • KBDI = 0 - 200: Soil moisture and large class fuel moistures are high and do not contribute much to fire intensity. Typical of spring dormant season following winter precipitation.
  • KBDI = 200 - 400: Typical of late spring, early growing season. Lower litter and duff layers are drying and beginning to contribute to fire intensity.
  • KBDI = 400 - 600: Typical of late summer, early fall. Lower litter and duff layers actively contribute to fire intensity and will burn actively.
  • KBDI = 600 - 800: Often associated with more severe drought with increased wildfire occurrence. Intense, deep burning fires with significant downwind spotting can be expected. Live fuels can also be expected to burn actively at these levels.

Chandler Burning Index Calculation
(0 - 120°F)
Relative Humidity
(0 - 100%)

Chandler Burning Index Fire Danger
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