Department of Meteorology Naval Postgraduate School Monterey, California 93943 SUMMARY of the October 2020 WEATHER ON THE MONTEREY PENINSULA General: October was yet another warm and dry month with light winds and more fog than normal. Marina recorded 10 days with fog (visibility less than a quarter mile), which is four more than the normal number of fog-days. Smoke, which had impacted the area during August and September was much reduced during October. Temperature: Temperatures during October can be quite warm to hot as the last vestiges of summer are possible with off-shore winds. Two of these episodes happened this past month (01-02 Oct and 15- 17 Oct) with temperatures into the 90s°F. Warmest reading at our Upper Monterey site was a toasty 98°F on 02 Oct. Carmel Valley reached 103°F and Big Sur 102°F on this day and the rest of our observers recorded 90°F or higher as well (below, see the table of Comparative Weather Data for Stations contributing to this summary). At our Upper Monterey site, one daily maximum record was set on 16 Oct with a reading of 93°F. This eclipsed the old record of 92°F set in 1967 and again in 1997. Daily warm minimum records were set or tied with 77°F on 01 Oct (old record was 66°F in 1980), 71°F on 15 Oct (tied old record set in 1961), and 70°F on 16 Oct bested the previous record of 64°F set back in 1967. For the month, average high was 76.5°F (6.0°F warmer than long-term average) and average low was 56.5°F (5.0°F above normal). A graphic of daily temperatures and precipitation for Upper Monterey is below. Precipitation: Only two of our sites recorded precipitation during October. A total of 0.12” was recorded at our Fort Ord site and Marina had 0.05” for the month. Of note, four of our eleven stations have not received any precipitation so far in this rain-year (July 01 – June 30). Rain-year totals as percentage of normal continued to drop with Marina the only station above 25% of average. Wind: Winds were light during October with the highest gust recorded in the area just 24 mph at Fort Ord. The rest of our local sites with anemometers reported peak winds in the 14-19 mph range for October 2020. Typical winds at Monterey Airport would average 5.1 mph with a peak gust in the low 30s mph range. Fog: Before April 2018, with 45 years of record, a fog-day was at least one hour of visibility less than six miles. Since then, a fog-day is one or more hours with visibility less than or equal to 1/4 mile. “Mist Days” are when visibility between 1/4 and six miles is reported for at least one hour. Long term statistics for fog describe “mist” days. Mist and fog-days at Monterey Peninsula Airport and Marina fog- days for July-September 2020: Monterey Peninsula Airport Marina Mist Days (Normal) Fog Days Fog Days (Normal) (vis. <6 mi) (vis. <1/4 mi) (vis. <1/4 mi) August 2020 5 (21) 1 9 (8) September 2020 10 (21) 9 13 (7) October 2020 15 (14) 7 10 (6) OUTLOOK for average temperature and precipitation for Monterey, November 2020 through January 2021: NOAA’s Climate Prediction Center ENSO (El Niño / Southern Oscillation) discussion summary on 09 November 2020 reports “La Niña conditions are present. Equatorial sea surface temperatures (SSTs) are below average from the west-central to eastern Pacific Ocean. The tropical atmospheric circulation is consistent with La Niña. La Niña is likely to continue through the Northern Hemisphere winter 2020-21 (~85% chance) and into spring 2021 (~60% chance during February- April).” NOAA’s Climate Prediction Center seasonal outlooks for November 2020 through January 2021 continue to indicate high confidence for above normal temperatures the central California coast and slightly below chances for normal rainfall. Normal temperatures and rainfall for Monterey for the next three months: Month Rainfall (inches) # of rain days Normal Max/Min. Temps (°F) November 2.22 7 65.0 / 47.2 December 3.27 9 60.0 / 43.8 January 3.91 10 59.9 / 43.4 NOTE: Current and past Monthly Monterey Peninsula Weather Summaries, as well as historic and climate information from the National Weather Service Climate Station, are available electronically at the following website: https://met.nps.edu/~ldm/renard_wx/ Comparative Weather Data for Stations on/near the Monterey Peninsula & Salinas October 2020 Following are comparative figures from eleven local observation sites: 1) Upper Monterey, located in the western hilly section of Monterey (elevation 606 ft); 2) Monterey Peninsula Regional Airport (KMRY) site (elevation 257’), located in the flat area of eastern Monterey; 3) Naval Postgraduate School Campus (NPS), Monterey, (elevation 45’); 4) the Ft. Ord site (Ft. Ord) elevation 167’, located just northwest of the Marina Municipal Airport. This is the site of the Naval Postgraduate School’s wind profiler managed by the Department of Meteorology); 5) Marina, located about 2½ miles ESE of Monterey Bay (elevation 135’); 6) Carmel Valley village vicinity Ford Rd. and Lilac Ln. (elevation 475’); 7) Salinas, vicinity of W. Blanco Rd. within ½ mile of S. Main St.; 8) Carmel, located on Rio Road near east end; 9) Seaside, vicinity of Paralta and Military Aves.; 10) Pacific Grove, vicinity of Sunset and Congress Sts.; 11) Big Sur Ranger Station, Highway 1, Big Sur. Temperatures (°F) Precipitation (inches) Wind (mph) Location Rain-year Normal / Avg. Highest Avg. Lowest This month (01 Jul – % of normal Max. Gust / Average Max. Min. October 31 Oct date(s) Upper 1.26* / ( 15 ) Monterey 76.5 98 56.5 47 0.00 b 0.18 14% 7th 1.2 Monterey % ( 17 ) Airport 73.3 93 52.1 46 0.00 b 0.02 --- 26th 3.8 NPS 0.95# / ( 17 ) 74.5 94 50.0 40 0.00 d 0.03 3% 17th 1.9 Ft. Ord ( 24 ) 74.1 94 48.7 38 0.12 b 0.27 --- 10th 7.5 Marina 0.93 & / ( 19 ) 72.0 89 48.7 38 0.05 a 0.25 27% 10th --- Carmel Valley 85.0 103 51.6 38 0.00 0.04 --- --- --- Salinas 0.84 ∆ / 79.8 99 52.6 42 0.00 0.00 0% --- --- Carmel 70.9 94 54.2 44 0.00 0.00 --- --- --- Seaside 72.3 93 50.6 41 0.00 0.00 --- --- --- Pacific Grove 70.6 90 52.9 46 0.00 0.15 --- --- --- Big Sur 80.9 102 55.9 43 0.00 0.00 --- --- --- FOOTNOTES: Observations for precipitation: a = 5 or 6 PM, b = midnight PST, c = 3 or 4 PM, d = 6 to 8 AM * = NWSCS/Upper Monterey 66-year average # = 51-year average, & = 30-year average, ∆= 24-year average % = Monterey Peninsula Regional Airport replaced NWSFO on 01 April 2019; Airport Temperature data missing 01-05 October 2020 Winds from Monterey Peninsula Airport (based on a 24-h period, ending at local midnight) .