|Moist - Little or no risk for large fires.|
|Dry - Low risk of large fires in the absence of a "High Risk" event.|
|Very dry - Low/Moderate risk of large fires in the absence of a "High Risk" event.|
High Risk Events
|Wind - strong winds combined with low RH (below 15%)|
|Dry lightning or any lightning during very hot, dry weather.|
Western Great Basin Area 7 Day
Significant Fire Potential
Issued: Friday, Aug 1, 2014 Parameters:
|Predictive Service Area||
|WB01 - Northwest|
|WB02 - Northern Mtns.|
|WB03 - Sierra Front|
|WB04 - West Central Mtns.|
|WB05 - Central Mountains|
|WB06 - Humboldt Basin|
|WB07 - Northeast|
|WB08 - West Desert|
|WB09 - East Central Mtns.|
|WB10 - Southeast Desert|
|WB11 - Southern Mtns.|
|WB12 - Southeast Mtns.|
|WB13 - East Desert|
Thunderstorms with wetting rains across most of the WGB through next week with elevated Initial Attack and LOW-MODERATE risk of large fires in the west/north.
Faster moving storms may increase the risk of drier storms Friday and Saturday over parts of northern NV with drier weather and lower RH spreading into western/northwest areas Friday through this weekend.
High pressure will remain dominant across the west through this week with temperatures near or slightly below normal due to clouds/showers with light to moderate winds. Monsoon moisture will remain across most of the WGB through next week bringing thunderstorms to most areas with scattered mostly wet thunderstorms over central, eastern and southern NV. However, a mix of wet/dry storms may still occur over parts of northwest/north central NV today as lighning continues on the edge of deeper moisture with faster storm motion.
Weak low pressure troughing off the west coast this weekend will also push thunderstorms slightly east today. Thunderstorms may initially develop along parts of the southern Sierra Front into the Pine Nut Mountains, but then move east as drier westerly winds develop. This drier air spreads into western/northwest NV through this weekend into early next week which allow for drier weather and RH dropping to 7-12% with fairovernight RH recovery this weekend, with a return of thunderstorms to all areas by Monday or Tuesday.
An easterly wave moving west across northern Mexico will move north over parts of southern/eastern/central/northern NV on Sunday/Monday bringing more widespread heavier wetting rains briefly to those areas with > 1.0" of rainfall easily likely in some areas.
SEE OUR MULTIMEDIA FIRE WEATHER BRIEFING AT: http://gacc.nifc.gov/wgbc/predictive/outlooks/briefing/briefing.html
SEE OUR DAY1 / DAY2 HEAT INDEX:
LOW fire potential across the eastern and southern half of the WGB through next week due to wetter thunderstorms. However, there are still some areas especially in the west and north that have not received much rainfall recently, have ERCs above normal and have live fuel moistures at critical levels. MODERATE significant fire potential continues through early next week over parts of western/northern areas. The greatest potential for large fires through this weekend would be in the north over PSA 1, 2 and 6 before moisture increases, and possibly into PSA 3/4 this weekend as drier air returns which may stir up holdovers.
Severe to Exceptional Drought Continues Across the WGB: http://droughtmonitor.unl.edu/Home/RegionalDroughtMonitor.aspx?west
The main areas of concern will be in the dry mid-higher elevations where larger fuel moistures are very low and stricken by long term drought, and if there are ignitions in the right areas of the lower elevations where there is some grass to carry fire and little rainfall has occurred.
100-hr fuel moisture continues to increase to well above normal over the eastern and southern areas with ERCs below normal. ERCs over western and northern areas have increased to above normal again, while 100-hr fuel moisture decreased rapidly and is near to below normal. Live fuel moisture continued to drop even with the increase in moisture recently, with some areas at/near critical levels across parts of the WGB. Recent rainfall and higher RH will mitigate some of the fuel concerns and provide a reprieve in some of the fine fuels, however still very dry conditions exist in the sagebrush/PJ/timber at mid-high elevations. Drought stress is ongoing across the landscape making fuels more critical in many areas, especially in Pinyon-Juniper and timber areas and over western and northern areas. Fuel moisture will increase in most areas this week due to showers/thunderstorms and increased RH.
SEE THE NATIONAL FIRE POTENTIAL MAP AT: http://psgeodata.fs.fed.us/staticmap.html
SEE A 7-DAY PROJECTION OF ERC, F100 AND F1000:
Western Great Basin Area Preparedness Level is 2: LIGHT, but elevated IA through this week due to continued lightning with rainfall. Anticipate LOW demand for outside of area resources through this week.
National Preparedness Level is 3: MODERATE-HIGH demand for resources in support of other geographic areas.
SEE THE MORNING REPORT AT:
Forecasters: McGuire 8/1/2014 0902 MDT