SDG&E Weather Briefing

Tuesday, October 22, 2019

Safety Talking Point

Remember – Water, Rest, Shade

  • Stay hydrated. Drink a quart of cool water every hour, even if not thirsty.
  • Use shade and rest.  Ensure shade is available at work areas; erect shade or utilize air conditioned truck cabs.  Break frequently to cool down.
  • If someone is showing signs of heat illness, immediately STOP all activity, move to a shaded cool area, offer sips of water, and call for emergency help.
  • Cover up and wear sunscreen.  Wear dual spectrum sunscreen that has an SPF of at least 15.  Sunburn reduces the skin’s ability to release excess heat, making the body more susceptible to heat-related illness.
  • Related information – Cal/OSHA Requirements for Heat Illness Prevention

Executive Summary

  • Weak Santa Ana winds of 30-40 mph this morning, diminishing by the afternoon
    • Temperatures into the 90s for many locations with humidity of 5-20%
    • Extreme FPI for ME and RA
  • A Fire Weather Watch has been issued for Inland OC and the SD County Mountains and Valleys from 3 AM Thu – 10 PM Fri
    • Winds with this event are currently forecast to be moderate, peaking in strength Fri
    • Temperatures will return to the 80s and 90s with widespread 5-10% humidity
    • An Extreme FPI is currently forecast for ME and RA on Thu, and for all inland districts on Fri
  • Milder conditions are forecast to return Sunday and continue into early next week

Forecast Discussion

October 20-22 Santa Ana Winds:

  • Timing:  Santa Ana winds will continue through this morning and diminish through the afternoon.
  • Peak Winds:  Gusts of 30-40 mph through mid-morning with the potential for isolated higher gusts in the usual wind-prone areas. 
  • Temperatures:  Highs in the 90s for many locations west of the mountains.
    • The National Weather Service has issued a Heat Advisory for the coast and valleys through this evening due to the projected hot conditions.
  • Humidity:  5-20% in all areas with minimal overnight recovery across wind prone locations.
  • Fire Potential:  An Extreme FPI is forecast for ME and RA today.  All other districts will be Elevated due to low humidity.
  • Santa Ana Wildfire Threat Index:  There is no SAWTI rating for today.

 October 24-26 Santa Ana Winds:

  • Timing:  Santa Ana winds will develop late Wednesday into early Thursday morning, peak late Thursday into Friday morning, and diminish Friday afternoon into Saturday.
  • Peak Winds:  Both Thursday and Friday will have the potential for wind gusts of 35-45 mph across the backcountry with isolated stronger gusts possible in the usual wind-prone areas.
  • Temperatures:  Highs in the 80s and 90s for most locations west of the mountains.
  • Humidity:  Widespread 5-10% with minimal overnight recovery.
  • Fire Potential:  An Extreme FPI is forecast for ME and RA Thursday and for all inland districts on Friday.  All other districts will be Elevated due to low humidity and very dry fuels with minimal fuel moisture recovery.
  • NWS Watches/Warnings: The National Weather Service has issued a Fire Weather Watch, which is expected to be in effect from 3 AM Thursday through 10 PM Friday for Inland Orange County and the San Diego County Valleys and Mountains.
  • Santa Ana Wildfire Threat Index:  The SAWTI is projected to be Moderate on both Thursday and Friday.

Fire Discussion

Weak Santa Ana winds will continue today, resulting in an Extreme FPI rating for ME and RA.  While gusty winds are not expected near the coast, widespread dry air will maintain the Elevated FPI rating through the coastal districts.  Winds are forecast to diminish this afternoon and remain light through Wednesday, but residual dry air will extend the Elevated FPI for all districts.  On Thursday, a moderate Santa Ana wind event is forecast to develop, which will cause the Extreme FPI rating to return to all inland districts by Friday.  Winds will become onshore on Sunday, ushering in higher humidities for coastal areas that will cause slight increases in dead fuel moistures and bring a Normal FPI rating back to our coastal districts.

Today's Fire Potential Index (FPI)

ME RA EA NE OC NC BC CM
Extreme

15

Extreme

15

Elevated

14

Elevated

14

Elevated

14

Elevated

12

Elevated

12

Elevated

12

< 12 | Normal 12 - 14 | Elevated 15 - 17 | Extreme

7-Day FPI Outlook

  Tue
10/22
Wed
10/23
Thu
10/24
Fri
10/25
Sat
10/26
Sun
10/27
Mon
10/28
ME Extreme

15

Elevated

14

Extreme

15

Extreme

15

Elevated

14

Elevated

14

Elevated

14

RA Extreme

15

Elevated

14

Extreme

15

Extreme

15

Elevated

14

Elevated

14

Elevated

14

EA Elevated

14

Elevated

13

Elevated

14

Extreme

15

Elevated

14

Elevated

13

Elevated

13

NE Elevated

14

Elevated

13

Elevated

14

Extreme

15

Elevated

14

Elevated

13

Elevated

13

OC Elevated

14

Elevated

13

Elevated

13

Elevated

14

Elevated

13

Elevated

12

Normal

11

NC Elevated

12

Elevated

12

Elevated

12

Elevated

12

Elevated

12

Normal

11

Normal

11

BC Elevated

12

Elevated

12

Elevated

12

Elevated

12

Elevated

12

Normal

11

Normal

11

CM Elevated

12

Elevated

12

Elevated

12

Elevated

12

Elevated

12

Normal

11

Normal

11

Forecast Weather Legend

< 12 | Normal 12 - 14 | Elevated 15 - 17 | Extreme

Latest 7-Day Forecast

Tue
10/22
Wed
10/23
Thu
10/24
Fri
10/25
Sat
10/26
Sun
10/27
Mon
10/28
EXPECTED WEATHER CONDITIONS
sunny
sunny
sunny
sunny
sunny
sunny
sunny
BEACHES
65/91 62/82 60/84 63/86 61/83 57/79 55/73
MESAS
65/96 63/86 61/88 63/92 62/87 59/77 57/75
MIRAMAR
64/97 61/89 61/91 63/94 59/90 57/80 54/77
INLAND ORANGE COUNTY
65/99 61/93 61/96 58/97 57/89 54/83 52/77
INLAND VALLEY
64/97 62/92 62/93 61/96 59/89 55/81 54/78
FOOTHILLS
62/94 60/91 62/91 59/93 55/87 52/80 50/76
MOUNTAINS
60/77 58/78 59/70 56/73 52/74 50/66 47/65
DESERTS
64/94 64/95 65/92 56/90 54/91 58/88 56/87
BACKCOUNTRY WINDS
30 15 35 40 20 20 20
CHANCE OF PRECIPITATION
0% 0% 0% 0% 0% 0% 0%

Forecast Weather Legend

High Heat (above 95F) Illness Prevention measures are mandated by Safety Standard G 8366: Pre-shift meeting to review preventive, cool down, and communication measures; Shade & 1 quart of cool water per hour per crew member required. Supervisors to observe for employee heat illnesses, or use a buddy system or regular communication with sole employees. Shading indicates Heat Illness Prevention (heat wave at or above 80F) measures are mandated by Safety Standard G 8366: Shade & 1 quart of cool water per hour per crew member required. Supervisors to observe for employee heat illinesses.
Shading Indicates low temperatures in this region are expected to be at 40 degrees Fahrenheit or lower Shading Indicates low temperatures in this region are expected to be at 32 degrees Fahrenheit or lower

Tide Report

LA JOLLA, SCRIPPS PIER, CALIFORNIA

Almanac

SAN DIEGO, CALIFORNIA

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