Transcript Slide 1

Summer 2009 Western Fire Season
Outlook Overview
• Significant fire potential is expected to be above normal
across much of California, Florida, central Texas, eastern New
Mexico, and portions of southern Oregon and western
Nevada for the following reasons:
– La Niña conditions are expected to persist at least through late spring.
This will likely lead to cooler and drier than normal conditions across
much of the west during late spring and early summer.
– Drought conditions exist and are expected to persist or worsen across
California, Nevada, Florida, central Texas, and portions of southern
Oregon.
– Lack of snow pack in the higher elevation areas of California, southern
Oregon, and eastern Utah will likely lead to more large fires than
normal, depending on lightning activity
– Fine fuel loadings from previous year(s) remain a considerable factor
for the plains of eastern New Mexico, Texas and eastern Colorado.
Percent of Normal Precipitation – U.S.
Note the very dry, persistent signals in CA, SE New Mexico,
Texas and Florida.
Percent of Average Precipitation for California
Last 3 Months
Last 3 Years
Percent of Average Precipitation for Western US
Last 3 Months
Last 3 Years
Current and Projected Drought
U.S. Temperature and Precipitation Departures During the
Last 30 and 90 Days
Last 30 Days
30-day (ending 18 Jan 2009) % of
average precipitation
30-day (ending 17 Jan 2009)
temperature departures (degree C)
Last 90 Days
90-day (ending 18 Jan 2009) % of
average precipitation
90-day (ending 17 Jan 2009)
temperature departures (degree C)
Pacific Niño 3.4 SST Outlook
A majority of ENSO forecasts indicate below-average Sea Surface Temperatures in
the central equatorial Pacific through Summer 2009. About half of the models
suggest La Niña conditions will continue through February-March-April 2009.
March through May La Niña Temperature and
Precipitation Anomaly Trends and Frequency of Occurrence
Temperature Anomaly
Temperature Frequency
Precipitation Anomaly
Precipitation Frequency
Northern California
• Much of Northern California remains dry this winter and will
likely see above normal significant fire potential during the
summer.
– La Niña conditions will likely limit precipitation and winter snowpack
across Northern California, which may lead to more large fires than
normal, depending on lightning activity
– The Sacramento Valley and Bay Area will likely see above normal
significant fire potential due to long-term and persistent drought.
– Limited fine fuel growth due to long-term drought could create
discontinuous fuels helping to retard fire spread in some areas
depending on spring precipitation amounts.
– Numerous fire scares from 2008 will provide “fire barriers” that should
help mitigate large fire growth in those locations.
Southern California
• The Central Coast Mountains and Valleys, Sierra
Foothills and Sierra Mtn areas will likely see above
normal significant fire potential due to long-term
and persistent drought.
– Lack of snow pack in the higher elevation areas could lead
to more large fires than normal, depending on lightning
activity
– Elsewhere, fire potential is expected to be near normal at
least through August. Santa Ana wind events could lead to
significant short duration fire activity in the southern
coastal and mountain areas during the fall.
Southwest
• Above normal fire potential in west Texas and eastern New
Mexico will spread west into central/southern New Mexico &
southeast Arizona later this spring.
– The current situation is quite similar to last year, with the southern and eastern portions
of the Area remaining quite dry.
– Fine fuel loadings from previous year(s) remain a considerable factor for the plains of
eastern NM/west TX and the Lincoln NF area in the south-central NM mountains.
– Northern AZ and NM, especially the mountains, have benefitted greatly from recent
snowfall and are expected to have little chance of large fire activity unless precipitation
amounts between now and early summer fall well below normal.
– Expect a similar situation to last year this coming spring, with the rangelands of eastern
NM/west TX becoming active as temperatures warm and more frequent windy/dry
events occur in conjunction with drought and abundant & cured carryover fine fuels.
– A significant determining factor will be whether or not the Area gets a few big wet
storms like last year. If they do, 2009 will be much like 2008 overall with AZ remaining
fairly quiet outside of the southeast portion of the state. If those storms don't
materialize, significant fire activity will occur across much of AZ south and west of the
Mogollon Rim during the May-June period.
– Note: The TFS and state/federal units in eastern NM/west TX are already prepping for
severity funds starting about 6 weeks from now.
Great Basin
• Outlook at this point is for normal fire potential
across the Great Basin, except for an area of above
normal on the Sierra Front in western Nevada.
– Snow pack amounts are near normal except for southeast
Utah and eastern Nevada.
– Fire activity in the Great Basin has not followed
dependable patterns during La Niña years.
– Snow melt timing and spring precipitation during March,
April, and May are the key indicators of fire activity in the
Great Basin.
Rocky Mountain Area
• Outlook at this point is for normal fire potential across the
Rocky Mountain Area this summer. The eastern foothills and
adjacent plains of Colorado, extending east into southern
Kansas and southwest Nebraska will likely see above normal
significant fire potential this spring (pre-green up).
– Snow pack amounts are above normal across much of the higher
elevation areas in western Colorado and below normal in southwest
Wyoming, eastern Colorado and southern Kansas.
– The strongest trend during La Niña years is for below normal
precipitation across eastern Colorado, Kansas and Nebraska during the
spring. Warmer than normal temperatures also occur about 40%-50%
of the time.
– Fine fuel loadings remain above average in eastern portions of the
Area.
– Summer fire activity will be dependent on the strength of the
Southwest Monsoon and dry lightning activity.
Northwest
• At this point, normal significant fire potential is
expected across most of the Northwest through early
summer.
– Cool and somewhat wetter than normal La Niña conditions
should allow for continued snowpack accumulation and
precipitation through early spring in most locations.
– Drier than normal precipitation patterns are quite
common following La Niña winters during late spring and
early summer, especially in southern Oregon and east of
the Cascades.
– Numerous mid and lower elevation large fires are likely
east of the Cascade Crest if precipitation patterns turn dry
late this spring.
– Southeast Oregon and the Okanogan Valley areas remain
relatively dry.
Northern Rockies
• At this early date, normal to below normal fire
activity is expected across the Northern
Rockies.
– Cool and somewhat wetter than normal La Niña
conditions should allow for continued snowpack
accumulation and precipitation through early
spring in most locations.
– Southwestern North Dakota remains relatively dry
and could see periods of large fire activity.
Texas and Florida
• Above normal fire activity is expected across much of
Texas, Florida, and portions of Oklahoma.
– Very dry conditions along with the presence of abundant
fine fuels will cause fire danger to spike in central Texas,
especially during windy periods combined with low
relative humidity often occurring in conjunction with cold
fronts.
– Developing drought in Florida is expected to result in
above normal initial attack activity and significant fire
potential later this spring and possibly into early summer.