National Significant Wildland Fire Potential Outlook
Predictive Services
National Interagency Fire Center
Issued: April 1, 2017
Next Issuance: May 1, 2017
Outlook Period – April, May and June through July 2017
Executive Summary
The significant wildland fire potential forecasts included in this outlook represent the cumulative forecasts
of the ten Geographic Area Predictive Services units and the National Predictive Services unit.
Florida and portions of Georgia, South Carolina, Texas and
New Mexico continue to experience significant fire activity
as warmer and drier-than-normal conditions persist. These
conditions will persist as the fire activity peaks across the
Southern Plains by May and across Florida through coastal
Carolina by early June. Periodic, event-driven pre-green up
grassfire activity continues across the central and northern
plains and in the lower elevations of the West. This is
normal activity and will continue to occur until full green up
takes hold. Developing drought conditions across Central
Texas and Oklahoma could elevate fire potential in May.
Western New Mexico and Arizona will begin to see an
increase in significant fire activity in May before the
monsoon begins to develop in late June and begins to
curtail activity. As the fire season progresses into June and
July, there are concerns with the seasonal shift west into
California and north into the central Rockies and Great
Basin. Exceptional winter and early spring precipitation will
lead to the development of a substantial crop of fine fuels in
the lower and middle elevations. The heavy loading of fine
fuels could become problematic when they cure out by July.
In the higher elevations, the mountain snowpack is
expected to melt at a normal to slower than normal rate due
to the abundance of high elevation snow and the
occurrence of an overall cool and wet spring. This could
produce a delay in the onset of significant fire activity in the
high elevations. In Alaska, the south central portion of the
state continues to be abnormally dry which has resulted in
a winter snowpack that is below normal. By mid-late July,
the western fire season will begin to progress north into the
Pacific Northwest and Northern Rockies. While a normal
transition into fire season is expected in the lower
elevations, a delayed entrance is possible in the higher
elevations.
.
Past Weather and Drought
The Southern Plains and New Mexico experienced extremely dry conditions through the third week of the
month before a pair of wet systems brought minor relief at month’s end. For the month, precipitation
totals were mostly 25% or less than normal east of the Rocky Mountain Front. The dry conditions along
with periodic wind events led to unusually active fire behavior. Kansas set a record for number of acres
burned for the month. Preexisting dry conditions across Florida and along the Atlantic Coast north
through Virginia continued. Wildfire activity in Florida increased. In the northwestern U.S., precipitation
was generally above average, and temperatures were near average. Mountain snowpack from northern
California and the Great Basin north to the Canadian border continued to accrue at faster than average
rates. Lower elevations continued to receive frequent rainfall which allowed for very moist soil conditions
to develop. This is expected to promote the growth of an abundant grass crop this spring. The northern
Plains were a slightly drier and warmer-than-normal. This led to an increase in pre-green up grassfire
activity. The Great Lakes and New England states generally experienced average conditions. In Alaska,
the drier and cooler-than-normal conditions continued as winter began to wane at month’s end.
While drought abatement continued across the West, drought development and expansion occurred
across eastern New Mexico, southeastern Colorado, and the Texas and Oklahoma Panhandles. Florida
and the southern Appalachians experienced increasing drought severity. Improving conditions were
observed along coastal areas of the Mid-Atlantic states and New England. In Alaska, the abnormally dry
conditions continued as fuels remained dormant.
Left: Departure from Normal Temperature (top) and Percent of Normal Precipitation (bottom) (from High Plains Regional Climate
Center). Right: U.S. Drought Monitor (top) and Drought Outlook (bottom) (from National Drought Mitigation Center and the Climate
Prediction Center)
Weather and Climate Outlooks
El Niño-Southern Oscillation (ENSO) continues in a neutral state.
Latest model forecasts show slight warming but continue to keep
ENSO in a neutral state through June with a weak El Niño
developing in July.
Temperatures will generally remain above average across the plains
through July. Along the West Coast, temperatures will lean toward
normal through June before trending toward above normal in July.
Across the Central and Northern Rockies and the Great Basin,
expect overall average temperatures. Colorado, Wyoming, and
Southeastern Montana could experience above normal temperatures
through June. East of the Mississippi, temperature trends will be
toward above normal through the period except along the Atlantic
Coast and Florida where the onset of summer sea/land breezes and
the tropical season forces both temperatures and precipitation back
toward normal levels and amounts. Alaska will continue to
experience below normal temperatures across the western half of
the state through May before temperatures normalize. The North
Slope and portions of the interior could see above normal
Temperatures in June.
Below normal precipitation trends will continue across the southern
tier of the country through June, though there are hints that a robust
monsoon may develop over the Southwest in June and July bringing
above normal precipitation to those areas. Portions of Central
Oklahoma and Texas could be very dry in May and June. Wetterthan-normal conditions are expected to continue through April across
the northern half of the Lower 48 and middle Mississippi River Valley.
Look for the precipitation to trend toward normal in May and June in
these areas followed by a further downward trend in July across the
Northern Rockies and Pacific Northwest.
Geographic Area Forecasts
Alaska: Normal significant wildland fire potential is expected for
Alaska April through July.
Abnormally dry conditions extend across the southwestern Interior,
Kenai Peninsula and southeastern Interior as below normal
precipitation continues across much of the. Cold conditions
prevented significant melting of the snowpack. Despite dry
conditions, most areas are near normal for snowpack except the
Matanuska and Susitna Valleys and the Copper River Basin which
are below normal.
After a very cold March across most of the state, a rapid transition to
warmer temperatures should occur in April except across
northeastern, inland, and southeastern Alaska where the warmup
should be less pronounced. The warmer-than-normal conditions are
expected to persist through summer. Precipitation forecasts show
below normal conditions are expected in the west at the end of
spring with these conditions lingering into summer. An area of above
normal precipitation is expected to develop over the eastern interior
in June and should last into August.
Normal fire season progression across the
contiguous U.S. and Alaska shown by
monthly fire density (number of fires per unit
area). Fire size and fire severity cannot be
inferred from this analysis. (Based on 19992010 FPA Data)
Northwest: Normal significant wildland fire potential is expected for the Northwest through the Outlook
period.
Rain and snow continued to accumulate through March for western Oregon and Washington. However,
sections of central and eastern Oregon remained fairly dry. Overall, temperatures were below average
for Washington and a few sections of western Oregon. While snow accumulations slowed in March due
to the onset of warmer temperatures and rain to higher elevations, amounts remained near to above
average. Overall, the snow accumulations at the end of March 2017 were much better when compared to
the 2015 and 2016.
Long-range data suggests a generally warmer and drier April for the northwest geographic area. For
May, the data is non-committal for temperature and precipitation, possibly indicating normal conditions
expected for the month. It appears that June will be cool and wet, followed by warmer and drier-thannormal conditions for July.
Northern California and Hawaii: Normal significant wildland fire potential is expected for Northern
California and Hawaii through July in all areas except the far eastern portions of the area which can
expect Below Normal wildland fire potential in response to a delayed on set of fire activity from the
historic winter.
Northern California experienced a very wet rainy season with the majority of the area recording greater
than 130% of normal precipitation since the water year began on October 1. Snowpack in the high
country is above 135% of normal at month’s end. The outlook for the region is for cooler and wetter-thannormal conditions through April followed by a trend toward normal temperatures and precipitation and
temperatures from May through July. These outlook conditions along with precipitation already received
will lead to a robust fine fuel crop at lower elevations that likely will not cure until sometime in July. They
will also lead to a greenup phase of live fuels at all elevations that reaches a peak at fairly high values,
and later in the spring or early summer than in recent years. As a result, a relatively late start (late July
or August) to the active fire season at middle and upper elevations is expected.
Sea Surface Temperatures in the vicinity of Hawai’i are expected to remain above normal through July.
Therefore, temperatures throughout the islands are expected to remain above normal. The current and
expected ENSO pattern will likely lead to near normal rainfall patterns throughout the region through
July. Outlook data suggests Hawai’i will receive near normal precipitation through July. The KeetchByram index remains well below normal for this time of year, and normal rainfall patterns will likely
continue. This indicates a normal trajectory for the fire season. Drought is non-existent across the islands
except for the island of Hawai’i. Therefore, other than portions of the Big Island which may experience
slightly above normal large fire activity at times.
Southern California: Normal significant wildland fire potential is expected in most areas of southern
California through July except in the Sierra Foothills where above normal significant wildland fire
potential is expected and the High Sierra where Below Normal significant fire potential is expected.
The rainy season is winding down over southern California. Farther north, periodic wetting rains continue
but at a diminishing rate. On average, rainfall amounts for March were 50% of normal. Temperatures
were about two to four degrees above normal region-wide. By month’s end, the previously wet pattern
allowed for most of southern California’s long-term drought to be eradicated except for areas along the
coast near Santa Barbara. Entering April, the High Sierras have a near record amount of snow depth
above 9,000 feet.
Significant soil moisture from the wet winter is leading to the growth of a heavy, dense crop of fine fuels,
which will begin to cure from south to north with increasing temperatures. While cooler-than-normal
temperatures are possible in the High Sierra in April, normal temperatures are likely elsewhere.
Temperatures should trend toward normal into mid-summer. Drier-than-normal conditions in June and
July could accelerate curing of fine fuels at lower and middle elevations.
Northern Rockies: Normal large fire potential is expected for the Northern Rockies through July except
for Yellowstone National Park which expects Below Normal large fire potential May through July.
Above average precipitation and near average temperatures continued during March west of the
Continental Divide, maintaining very moist conditions that have been in place since last October. Most of
southwestern and central Montana had much drier and milder conditions, as a southwesterly to westerly
flow aloft kept weak weather systems from delivering much moisture there. Eastern Montana and North
Dakota experienced near to above-average precipitation over the past month, with near to below
average temperatures, as weak pushes of cooler Canadian air were able to persist. Mountain snowpack
across the region experienced major gains. Live fuels remain in winter dormancy. Dead fuel moisture
levels have risen accordingly. Fuels are wet west of the Continental Divide. Sustained periods of warm
dry windy weather east of the Continental Divide often heighten grass and brush-fire potential from
March to April.
Near to above average precipitation is expected through the spring months along with average
temperatures. Latest long-range data suggests above average temperatures may develop in July over
North Idaho and most of Montana, but with near average precipitation. With average temperatures and
precipitation expected to continue through the rest of the spring, greenup should proceed rapidly.
Average to above-average mountain snowpacks should melt at a normal rate as well through the spring.
Great Basin: Normal significant wildland fire potential is expected across the Great Basin in April and
May. For June and July, expect below normal significant fire potential across the mountains of central
Idaho, the High Sierra along the Nevada-California border, and the mountain ranges from the Grand
Tetons south through the Wasatch range in northeastern Utah.
After an anomalously wet winter, the first three weeks of March saw precipitation across the majority of
the Great Basin at less than 50 percent of normal. Temperatures were also above normal across the
area for March, leading to the beginning of spring runoff across many of the high elevations of the Great
Basin.
Most high elevation sites were reporting 130 percent of normal or more. Central and southern Utah were
reporting 50 to 70 percent of normal snow water equivalent. A robust grass crop was developing across
the lower elevations of the Great Basin, particularly across western Nevada. Fine fuels are just beginning
to green up across the central and southern portions of the Great Basin. This grass crop is expected to
play a significant role in fire activity later this season.
Climate outlooks call for above normal temperatures across the Great Basin. Precipitation is expected to
be near normal across the majority of the Great Basin, though there is potential for some above average
precipitation across the northern portions of the area. If the anomalously warm temperatures come to
fruition, the abundant fine fuel crop will begin curing by mid to late June. As early as late April, brief
periods of increased fire potential may be observed during warm and windy events especially in areas
with high grass loading. There have been reports of grasses extending higher in elevation than is typical,
which could allow fires to make bigger than expected upslope runs in fine fuels before 1000-hr fuels have
dried. There is concern regarding elevated fire potential in July across the lower elevations of much of
Nevada and southwestern Idaho.
Southwest: Above Normal significant wildland fire potential is expected across southern and
southeastern New Mexico and southwestern Texas for April. Above normal potential will shift west to
areas generally west of the continental divide by May, then spread northward west of the continental
divide by June.
March temperatures were above normal across most of the region, especially the southeastern corner.
While most areas experienced below normal precipitation, a swath of above normal precipitation
occurred from southwestern Arizona to northeastern Arizona and northwestern New Mexico. The wet
beginning to winter turned drier and milder over the past two months across the region. Ridging has been
interspersed with weak systems that have not brought much precipitation overall. As a result above
normal snowpack in February is diminished with only the Colorado border region and the far northern
Mogollon rim area reporting above normal conditions. The overall drier weather pattern brought
enhanced westerly to southwesterly flow at times which led to downslope conditions across areas on the
lee side of the New Mexico central ranges.
A wetter pattern is expected in April for the northeastern half to third of the region which will rapidly
diminish significant fire potential. Areas farther south and west, however, are expected to have above
normal significant fire potential during April. By May drier and warmer weather focused west of the
continental divide will focus above normal significant fire potential across much of southern Arizona, as
areas farther east will likely see enhanced moisture. In June, significant fire potential is expected to
increase farther north and west of the divide as areas to the east continue to see regular moisture. Above
normal significant fire potential in these areas will be revolving around normal to above normal fine fuel
loadings and eventually lightning as the primary ignition source. The monsoon is more than likely to
begin early or on-time and will drop significant fire potential regionally in July. Confidence in this overall
outlook is average with higher confidence during April into May overall.
Rocky Mountain: Below normal significant wildland fire potential is expected in the higher elevations of
Colorado and northwestern Wyoming May through July. Elsewhere across the region, expect normal
significant wildland fire potential through July.
A warmer and drier-than-normal early spring continued into the first half of March for the region. The
latter half of March became wetter and cooler-than-normal. This change in the pattern reduced long-term
drought which had developed across portions of eastern Colorado and Kansas. An abundant dead grass
and brush fuels remains in place in the lower elevations and foothills of the Rocky Mountain Area.
However, greenup conditions are anticipated to expand in the lower elevations and grasslands from
south to north during April, reducing the threat of fire activity as the month progresses. Fuel-beds are
under snow cover across most mountain locations, with snowpack values well above normal except in
the Black Hills of South Dakota.
Forecast data for April suggests an average temperature and precipitation pattern is expected.
Climatologically, April is one of the wetter months of the year. Brief periods of windy, warm and dry
weather can be expected mainly across southeastern Colorado and Kansas during the first half of the
month. The forecast data suggests above average temperatures in the south and west and average
temperatures and precipitation elsewhere for May through July. During April, the region historically
experiences pregreenup fire occurrences mainly during the first half of the month east of the Continental
Divide. Considering the precipitation received during the second half of March and the forecast during
the first half of April; a trend of decreasing large fire risk is expected as greenup spreads northward
during the month in the lower elevations. Below Normal large fire potential with a later than normal start
to the core fire season is expected in the mountains of western Wyoming and Colorado. While the
abundant snowpack coupled with recent and forecasted precipitation is expected to lead to an overall
below average large fire potential in the high country, the foothills can expect normal large fire potential
during the outlook period.
Eastern Area: Normal significant wildland fire potential is expected for the Eastern Area through the
Outlook period.
Soil moisture and precipitation anomalies were below normal across portions of the Middle and Upper
Mississippi River Valley and New England. Some residual long-term drying also remained in place
across portions of New England and the eastern Mid-Atlantic States. Near to above normal precipitation
and soil moisture anomalies were in place over the rest of the Eastern Area toward the end of March.
Warmer-than-normal temperatures are forecast across the southern and eastern tiers of the Eastern
Area from April into June. Normal spring shower and thunderstorm activity is expected across the
Eastern Area in April producing normal fuel conditions and therefore normal spring fire activity prior to
vegetation greenup. Drier-than-normal conditions are forecast across portions of the Upper Mississippi
River Valley in May. These drier-than-normal conditions are expected to spread eastward into the MidAtlantic States in June. Wetter-than-normal conditions may develop over parts of the Great Lakes down
into northern Illinois and Indiana eastward into parts of the Mid-Atlantic States. The spring fire season
may begin earlier than normal across the northern tier of the Eastern Area if warmer-than-normal
conditions persist into April.
Southern Area: Above normal significant fire potential is expected through July from the coastal areas
of South Carolina through Florida and across portions of Texas. Below normal large fire potential is
expected from Texas northeast through Kentucky in April and May, returning to normal in June. Above
Temperatures across the region were generally above normal during March. Precipitation, however, was
generally below normal except across the Lower Mississippi and Tennessee River Valleys where above
normal precipitation reduced large fire potential as forecasted. The greatest departures from normal were
across Oklahoma and Texas and across Florida, Georgia and the Carolinas. Fire activity in both areas
increased significantly.
Overall, current trends are expected to continue through April before slowly beginning to show
improvement in May and June. Relief in Florida will be aided by the onset of the tropical weather season
in June. For April, drier-than-normal conditions are expected in all areas except for the Lower Mississippi
and Tennessee River Valleys. Above normal temperatures will aid full greenup, but live fuel moistures
may be somewhat lower than average. While drier-than-normal conditions are expected in May,
precipitation amounts received should show a trend toward normal. Cooler-than-normal temperatures are
expected in the southern Appalachians in May. Looking ahead to June and July, overall warmer and
drier-than-normal conditions are expected. There are indicators that suggest that central Texas could be
much drier-than-normal. South Florida might be an exception if an active tropical season develops.
Outlook Objectives
The National Significant Wildland Fire Potential Outlook is intended as a decision support tool for
wildland fire managers, providing an assessment of current weather and fuels conditions and how these
will evolve in the next four months. The objective is to assist fire managers in making proactive decisions
that will improve protection of life, property and natural resources, increase fire fighter safety and
effectiveness, and reduce firefighting costs.
For questions about this outlook, please contact the National Interagency Fire Center at (208)
387-5050 or contact your local Geographic Area Predictive Services unit.
Note: Additional Geographic Area assessments may be available at the specific GACC websites. The GACC websites can also
be accessed through the NICC webpage at: http://www.nifc.gov/nicc/predictive/outlooks/outlooks.htm