10. Oct- Dec Number of Fires by Year
Fires
8000
Feb-Apr
Spr- Sum
7000
6000
5000
4000
3000
2000
1000
0
11. June- August 2012
• 2,033 fires
• 51,747 acres
Other comparisons:
Jan- March 1942
•3,586 fires/118,610 ac.
July-Sept. 1980
•2,768 fires/73,070 ac.
12. Fires Larger Than 100 Acres
#Acres County Date
537 Miller June 23
142 Franklin June 29
160
#Acres Clark
County June 29
Date
400
104 Clark
Lafayette June 29
July 19
110
109 Conway
Faulkner June330
July
115
110 Hot Spring
Conway July 1
June 30
250
115 Clark
Hot Spring July 1 1
July
115
293 Dallas
Logan July 4 1
July
116 Independence July 28
109 Faulkner July 3
140 White July 3
140 White July 3
142 Franklin June 29
471
160 Pope
Clark July 3
June 29
115
179 Dallas
Ashley August 4
July 3
116
199 Clark
Independence July4
July 22
200
200 Dallas
Dallas July 4 4
July
200
250 Benton
Carroll August 4
July 7
232 Sharp August 15
104 Lafayette July 19
250 Clark July 1
199 Independence July 22
250 Carroll July 4
1,014
274 Yell
Hot Spring July 25
July 30
116
o293 Independence
Logan July128
July
355
300 Garland
Van Buren August 29
July 28
355
274 Garland
Hot Spring July 29
July 30
400
380 Clark
Benton June 292
Aug.
471 Pope July 3
179 Ashley Aug. 3
537 Miller June 23
825
825
PerryPerry
Aug. 13
August 13
852
852 Clark
Clark Aug. 13
August 13
1,410
1,014 Drew Yell Aug. 14
July 25
232
1,410 SharpDrew Aug. 15
August 14
300 Van Buren Aug. 28
13. Fires by Cause (AVG) 1992 - 2011
800
700
600
500
400
Fires
300
200
100
0
Inc Debris Smokers Railroad Campfire Equip Children Lightning Misc
16. Extreme Fire Behavior Conditions:
•Relative humidity is below 20%
•Wind speeds above 20 mph
•Dispersion Index value of 80+
•Haines Index - 6
•KBDI - 700-800
•Fine fuel moisture below 5%
•Dust devils/fire whirls
•Spotting in several directions
•Thunderstorm on the horizon
18. Wind Information
20 foot winds- ≥20
mph
Winds at 20 feet above the
ground or 20 feet above the
average height of vegetation
are used in the routine fire
weather forecast.
19. Dispersion Index
ADI Description
Poor dispersion, stagnant air if conditions
0-20 persist.
Poor to fair dispersion, stagnation possible
21-40
with low wind speeds.
41-60 Generally good dispersion.
Very good dispersion, control problems
61-80 likely.
Excellent dispersion, control problems
80 + expected.
20. Keetch-Byram Drought Index
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.
200-400 Typical of late spring, early growing season. Lower
litter and duff layers are drying and beginning to
contribute to fire intensity.
400-600 Typical of late summer, early fall. Lower litter and duff
layers actively contribute to fire intensity and will burn
actively.
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.
21.
22.
23. Thunderstorm
Winds
Strong and shifting winds. Speeds often greater
than 30 mph result in erratic fire behavior.
Wind speeds often enhanced by the forward
movement of the storm.
Outflow typically precedes rain by 3-5 miles, but
can be much more.
24. Red Flag Warning
Criteria
• Afternoon minimum relative humidity expected
to be 25% or lower.
• 20 foot sustained winds in excess of 14
mph.
• Fuels that are determined to be critically
dry (less than 10 percent for 10 hour fuels).
• Other parameters that are considered
include the likelihood of lightning occurrence,
wind shifts, and/or current wildfire activity.
Thanks God for Hurricane Isaac which entered Arkansas on August 30.
Prescribed Fire School question.Fire occurred on May 23 near Brewer community in Cleburne County- GBP tract.
Fire occurred on May 28 near Jerusalem in Conway County. GBP and AFC had 5 dozers on the fire. The fire burned 97 acres mostly a 7 year old pine plantation.
I was surprised by October through December. 1989 we had 761 fires in November and 804 in December.March is higher because
Lightning was a problem this summer. Lightning fires caused 25% of the fires in June and July. In August 42% of the fires were by lightning.
Casa Fire (Fire # 277) in Perry County that burned 820 acres on August 13. AFC air attack was looking at some other fires when they spotted a small 3-5 acre fire in a cut over. There was a smaller fire north of the Casa fire that was also a lightning strike- Mary Lane fire.
AFC has fire records going back to 1935 with number of fires and number of acres burned by month. We thought this year was bad. 1952 we had fires 7,326 fires. 1963 we had 5,702 fires. 1980 has blue arrow had 6,128 fires.
Little Rock National Weather Service provides Fire Weather information at 7:30 am and 3:30 pm.
There are certain factors that warn of extreme fire behavior conditions. This is the Ola fire that occurred on July 25, 2012. This fire burned 1,014 acres. This picture was taken by Doug Cloud with Tysons.
Generally getting into August we will see RH’s get down to 20%. This summer we had RH get down to 9%.
This is the prevailing wind speed in miles per hour at the level of 20 feet above vegetative cover. Eye level winds are about half.
The Dispersion Index is a numerical indicator of how well and how rapidly smoke will be dispersed. It utilizes stability, mixing height, and transport wind as the major factors. Other factors are: the amount and angle of sunlight and temperature.
The Keetch-Byram drought index (KBDI) is a continuous reference scale for estimating the dryness of the soil and duff layers. The index increases for each day without rain (the amount of increase depends on the daily high temperature) and decreases when it rains. The scale ranges from 0 (no moisture deficit) to 800. The range of the index is determined by assuming that there is 8 inches of moisture in a saturated soil that is readily available to the vegetation.For different soil types, the depth of soil required to hold 8 inches of moisture varies (loam=30", clay=25" and sand=80"). A prolonged drought (high KBDI) influences fire intensity largely because more fuel is available for combustion (i.e. fuels have a lower moisture content). In addition, the drying of organic material in the soil can lead to increased difficulty in fire suppression.High values of the KBDI are an indication that conditions are favorable for the occurrence and spread of wildfires, but drought is not by itself a prerequisite for wildfires. Other weather factors, such as wind, temperature, relative humidity and atmospheric stability, play a major role in determining the actual fire danger. KBDI for the Drew County 1,410 acre fire on August 14 was 759.
The amount of moisture in fuel is the major element that will determine how much of the fuel will burn (available fuel). According to how much moisture is in the fuel, all will burn, only part will burn or, if wet enough, none will burn. Fuel moisture values down to 3% with temperatures of 95 degrees plus. Probability of ignition was 80% or greater.
