Day 3-8 Fire Weather Forecast Issued on Dec 27, 2017

Updated: Wed Dec 27 21:04:03 UTC 2017

Day 3 Experimental 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 Experimental 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 Experimental 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 Experimental 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 Experimental 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 Experimental 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 D3 7,328 7,208 No Major Population Center in Risk Area

   ZCZC SPCFWDD38 ALL
   FNUS28 KWNS 272102

   Day 3-8 Fire Weather Outlook  
   NWS Storm Prediction Center Norman OK
   0302 PM CST Wed Dec 27 2017

   Valid 291200Z - 041200Z

   Upper ridging over the western CONUS will be suppressed from Day
   3/Friday into Day 4/Saturday as a shortwave trough moves across the
   Pacific Northwest. This shortwave trough should move southeastward
   across the central Rockies and vicinity on Day 5/Sunday,
   contributing to broad mid/upper-level cyclonic flow across the
   central/eastern CONUS. Upper ridging now appears likely to become
   re-established across the eastern Pacific and western CONUS from Day
   5/Sunday through at least early next week.

   ...Day 3/Friday - Day 4/Saturday: Portions of the Southern High
   Plains...
   A surface low is forecast to strengthen across the southern/central
   High Plains on Day 3/Friday, and a corresponding increase in the
   surface pressure gradient is expected across eastern NM Friday
   afternoon. Guidance is now in good agreement in depicting an overlap
   of strong/gusty downslope winds and critically lowered RH values
   across a small part of east-central NM. A 70%/likely critical area
   has therefore been included for Day 3/Friday for this region, and
   the 40%/marginal area has been expanded eastward to include more of
   the southern High Plains.

   Strong/gusty downslope winds may occur again on Day 4/Saturday in
   conjunction with critically lowered RH values across the same
   general area, but guidance is in somewhat less agreement with the
   strength and duration of these winds on Saturday afternoon. Have
   introduced a 40%/marginal area for a small part of east-central NM
   on Day 4/Saturday to account for this potential critical fire
   weather threat.

   ...Day 3/Friday and Day 7/Tuesday - Day 8/Wednesday: Portions of
   Southern CA...
   Generally weak offshore winds may be ongoing Friday morning across
   parts of southern CA as the surface pressure gradient remains
   slightly enhanced over this region. Latest guidance continues to
   indicate that the pressure gradient will weaken by Friday afternoon,
   and any locally strong/gusty wind threat across the higher terrain
   of southern CA should diminish by Friday evening. Forecast sustained
   winds do not warrant any probabilities for critical fire weather
   conditions, although locally elevated conditions could occur in the
   more wind-prone/higher terrain areas early in the Day 3/Friday
   period.

   Medium-range guidance is now in better agreement in depicting upper
   ridging redeveloping over the western CONUS for early to middle
   portions of next week. There appears to be some potential for a
   surface high beneath the upper ridge to develop/strengthen across
   the northern Great Basin/Rockies in the Day 7/Tuesday - Day
   8/Wednesday time frame. However, previous model inconsistency
   regarding this scenario and a marginal forecast surface pressure
   gradient suggest it would be premature to introduce any
   probabilities for southern CA at this time.

   ..Gleason.. 12/27/2017

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

   $$

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