Day 3-8 Fire Weather Forecast Issued on Sep 14, 2021

Updated: Tue Sep 14 21:44:03 UTC 2021

Day 3-8 Fire Weather Forecast Graphic Issued on Sep 14, 2021
 
Day 3 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 3 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Day 4 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 4 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Day 5 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 5 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Day 6 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 6 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Day 7 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 7 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Day 8 Probabilistic Dry Thunder/Strong Wind FireWX Forecast Graphic Issued on Sep 14, 2021

Day 8 Probabilistic Fire Weather Outlooks:
Probability of dry thunderstorms with dry fuels within 12 miles of a point denoted by scalloped lines for
- Critical Area - 40% (blue)
- Marginal Area - 10% (brown)
Probability of strong winds, low RH, and warm temperatures concurrent for at least 3 hours with dry fuels within 12 miles of a point denoted by solid lines for
- Critical Area - 70% (red)
- Marginal Area - 40% (orange)


Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
D3Thu, Sep 16, 2021 - Fri, Sep 17, 2021 D6Sun, Sep 19, 2021 - Mon, Sep 20, 2021
D4Fri, Sep 17, 2021 - Sat, Sep 18, 2021 D7Mon, Sep 20, 2021 - Tue, Sep 21, 2021
D5Sat, Sep 18, 2021 - Sun, Sep 19, 2021 D8Tue, Sep 21, 2021 - Wed, Sep 22, 2021
(All days are valid from 12 UTC - 12 UTC)
   ZCZC SPCFWDD38 ALL
   FNUS28 KWNS 142139

   Day 3-8 Fire Weather Outlook  
   NWS Storm Prediction Center Norman OK
   0439 PM CDT Tue Sep 14 2021

   Valid 161200Z - 221200Z

   Multiple mid-level troughs will traverse the interior West and
   Plains states through the extended period, promoting periodic
   episodes of dry and breezy conditions supporting at least modest
   wildfire-spread potential across two main areas. First, surface dry
   and windy conditions are expected across the interior West as a
   prolonged period of strong flow aloft from multiple passing
   mid-level troughs is expected to overspread the region, mixing down
   via a dry boundary layer. Second, broad cyclonic flow aloft across
   the West will also support persistent surface lee troughing to the
   east of the Rockies. The south-southwest trajectory of the surface
   flow to the lee of the Rockies will be relatively dry, promoting
   modest potential for fire spread despite mediocre fuel
   receptiveness. 

   ...Day 3/Thursday...
   The first upper trough and associated cold front in the series may
   bring dry and breezy conditions across parts of the Great Basin into
   the central Rockies on Day 3/Thursday. 15+ mph sustained
   southwesterly surface winds are expected to coincide with 15-20% RH
   for at least a few hours. Given the expected Elevated conditions
   over modestly receptive fuels, 40% Critical probabilities were
   introduced. Farther east into the southern and central High Plains,
   surface lee troughing will encourage 15+ mph sustained southerly
   winds, but with RH struggling to drop below 20%. Given marginal RH
   and fuel receptiveness, no Critical probabilities were issued,
   though Elevated highlights may need to be added in future outlooks
   if forecast RH trends lower and meaningful precipitation
   accumulations are avoided.

   ...Days 4-7/Friday-Monday...
   Zonal flow will be dominate the West Day 4/Friday, with dry and
   windy conditions constrained to terrain-favoring areas, precluding
   Critical probabilities at this time. The second in a series of
   troughs approaches Day 5/Saturday, bringing widespread dry and windy
   surface conditions across the northern Great Basin into the central
   and northern Rockies. The upper trough will continue to amplify
   along the West Coast, with dry/windy conditions expected yet again
   for portions of the Great Basin. 40% Critical probabilities have
   been introduced for both Days 5-6 across parts of the interior West,
   though some uncertainties exist with placement and timing of the
   more favorable surface wind/RH/receptive fuels overlap(s).
   Probabilities were added where medium-range guidance showed the
   greatest agreement in near-critical to critically dry/windy surface
   conditions occurring. Forecast uncertainty only increases at and
   beyond Day 7/Monday across the interior West, with Critical
   probabilities withheld despite the possibility that dry and breezy
   conditions may persist to the end of the period.

   By Day 6-7/Sunday-Monday, as the upper trough continues to slowly
   advance eastward across the interior West, surface lee troughing
   will gradually intensify, promoting dry southerly flow across the
   central and southern High Plains. Considerable differences in
   surface wind speeds exist among medium-range guidance members
   however. When also factoring in the marginal receptiveness of fuels
   to fire spread, Critical probabilities have been withheld this
   outlook. Critical probabilities may be needed in future outlooks
   pending better agreement on stronger surface winds.

   ..Squitieri.. 09/14/2021

   ...Please see www.spc.noaa.gov/fire for graphic product...

   $$

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