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Wildfire potential, September through December

Bill GabbertSeptember 1, 2014September 1, 2014Uncategorizedpotential, weather1 Comment

The Predictive Services section at the National Interagency Fire Center has issued their Wildland Fire Potential Outlook for September through December, 2014.

The data represents the cumulative forecasts of the eleven Geographic Area Predictive Services Units and the National Predictive Services Unit.

If their predictions are accurate, firefighters could be busy in Washington and Oregon through October, and busy in southern California into December. The fall fire season in the southeast looks like it will be normal or slower than normal.

September

Above normal fire potential will remain across southwestern Oregon through September for lingering dryness and potential dry, east winds.
Fire potential will remain elevated across portions of California. Continued dry fuels will couple with potential offshore winds.
Below normal fire potential is expected to continue for some portions of the eastern U.S. and the Hawaiian Islands.

October

Above normal fire potential will persist across California as fuels will remain dry and off shore flow season arrives in earnest. Northern and central California will return to normal potential by the end of the month.
Below normal fire potential is expected to continue for some portions of the southern Plains, Florida, and Hawaii.

November and December

(Note: there was a technical problem in getting a good copy of the image below.)

Above normal fire potential will persist across southern California as offshore flow potential continues. Expect a return to normal potential from north to south beginning in late November through December.
Below normal fire potential is expected to continue for the Gulf and Southeast Coasts, and Hawaii.

Fire weather outlook, August 29 through September 2

BillAugust 29, 2014UncategorizedChris Redmond, weather

An upper level trough will cross the northwest Pacific states Fri/Sat and eject into the central Plains on Sun. This will bring periodic windy conditions across the western US and cooler weather for the northwest. No critical widespread critical fire weather is expected, although some areas will have enhanced conditions that will aid in fire spread, especially with drought conditions across the west. Continued heat is expected for the southwest with dry conditions prevailing.

The primary fire threat across the US will focus on warm temperatures and low RHs in the western Great Basin Fri and Sat. Breezy westerly winds are expected Fri/Sat especially across much of NV due to the approaching upper level trough. As the trough shifts eastward, wind conditions will move across northern UT and southern WY/northern CO into Sun/Mon. Dry conditions over much of WY/CO will provide an increased fire risk with these strong westerly winds.

The southwestern US will remain dry and hot through the period. Portions of central/eastern CA/NV/AZ will have poor RH recovery overnight. Though no windy conditions are expected across this region, above average temps and below average precipitation will lead to conditions conducive to human caused fire starts and challenges for suppression

A cold front crossing WA/OR will bring breezy conditions Fri, however, temperatures are expected to remain cool and RH is expected to remain above critical levels. A lack of upper level moisture will prevent any thunderstorm development, however some light rains are possible along western slopes. A stable post-frontal air mass will provide quiet conditions for the Pacific Northwest and eastward with the front’s advancement through the weekend. Cooler weather is expected to continue through the period for WA/northern OR/MT/northern ID with warming conditions likely Tues in advance of the next system.

Long term into mid-week, a summer type pattern looks to return for the central US with another trough pushing into the west. This may develop enhanced fire weather conditions across the western US mid-week and central Rockies mid-to-late week and should be monitored.

Five-day precipitation outlook, issued August 29, 2014.

Weather Highlights:

Eastern CA/NV: Breezy westerly winds Fri/Sat with low RH and warm temperatures. Locally critical fire weather is possible, otherwise generally enhanced fire weather is expected across the region. Winds will be decreasing Sun.

WA/OR: Breezy conditions are likely today across central portions of OR/WA on the eastern sides of the Cascades. Moderate temperatures and RH should prevent any increased fire risks. Warming with decreasing RH across southern OR late weekend and moving northward into next week.

Southern WY/northern CO/northern UT/southern ID: Developing strong westerly winds Sun/Mon. Combined with warm and dry conditions, this will lead to an enhanced fire threat continuing into mid-week.

Southern/central CA/AZ: Continued warm and dry with poor RH recovery. Some breezy winds Fri in eastern CA, otherwise no significant winds/thunderstorms.

A rainy week

Bill GabbertAugust 25, 2014August 25, 2014Uncategorizedweather4 Comments

The last seven days have been very wet in some parts of the United States, especially in north-central Montana where, according to the NOAA map above, some areas had five to eight inches of precipitation. (Click on the map to see a larger version.)

Lightning in the Black Hills

Bill GabbertAugust 23, 2014August 23, 2014Uncategorizedlightning, Photo by Bill G, South Dakota, weather6 Comments

Lightning strikes a tree in the Black Hills of South Dakota at 2:21 p.m. MDT, August 23, 2014. Photo by Bill Gabbert

Fire weather outlook, August 23 through 28

BillAugust 23, 2014UncategorizedChip Redmond, weather1 Comment

A large, slow-progressing upper level trough has brought copious moisture to much of the northern Rockies and Eastern Great Basin. Even some winter weather advisories with very a cool air mass over MT. Widespread fire weather threats have been minimal across much of the western US and will likely remain quiet through the weekend. Despite the lack of optimal large fire conditions, several areas will need to be monitored for developing potential into mid-week.

As the trough begins to lift northeast into the northern Plains and Canada early week, another final shortwave will rotate around the apex on Monday. This will bring a slight chance of showers and thunderstorms across portions of NV/UT. With lack of low level moisture and drying taking place over the weekend, a few isolated dry thunderstorms are possible. No strong winds are anticipated outside of thunderstorm outflows. The threat will diminish Tuesday evening.

A big story will be developing, with upper level ridging along the West Coast and subsequent drying conditions and warming temperatures early week. These conditions will aggravate already drought stricken regions and provide ripe conditions for fire growth for CA and northward into OR/WA. No widespread thunderstorms or wind events are anticipated. However, temperatures above 90F and widespread RHs <20% with some <10% for central OR and northern CA by Wednesday will promote extreme fire behavior.

Weather Highlights:

NV/UT/southern ID: Isolated dry thunderstorms Mon/Tues. Becoming hot and mid-week.

OR/WA: A few scattered showers on Sun, lingering into Mon. Becoming very hot and dry Tues and continuing into late week.

CA: Warm and dry Sat/Sun. Becoming very hot and critically dry by mid-week.

Chip