Department of Meteorology Naval Postgraduate School Monterey, California 93943 SUMMARY of the January 2021 WEATHER ON THE MONTEREY PENINSULA General: January began with a weak storm dropping nearly half an inch of rain over the region. A ridge of high pressure then built in giving us nearly a week of warm, dry weather. This ridge retrograded to the southwest opening the storm door for cool, windy and wet Gulf of Alaska storms to impact the local area. The combination of high winds with lots of precipitation during the storm of 26-28 Jan led to many fallen trees and branches with resultant power outages across the Monterey Peninsula. Hwy 101 was closed for a period due to water over the roadway near Chualar (which was also flooded) and parts of Hwy 1 were damaged south of Big Sur due to washouts. Regions impacted by recent fires were on high alert for debris flows. Storms in January are not uncommon, but this one stalled over our area and produced impressive rainfall totals in the local area. Figure 1. Visible satellite image of major storm approaching on the afternoon of 26 Jan 2021. Temperature: Monterey’s long-term average temperatures in January are 59.9°F for daily highs and 43.4°F for overnight lows. This past month exhibited distinct periods: near normal 01-05 Jan, warmer than average 06-13 Jan, near-record warmth 14-19 Jan and below normal after 22 Jan (see graphic of daily temperatures and precipitation for the month for Upper Monterey, below). During 14-19 Jan, sites in the local area reached as high as 85°F at Big Sur (16th), 84°F (15th) and 83°F (17th) at Salinas and 81°F (14th and 15th) at Carmel Valley. Lowest temperatures in the area were 30°F at Fort Ord and 31°F at Marina, where three days with frost/car ice (normal is six) were reported. (See Table of Comparative Weather Data for Stations contributing to this summary, below). For Upper Monterey, the highest temperatures were 75°F on 17 and 18 Jan, with the coldest low of 40°F on the morning of 26 Jan. Averages for the month were 61.2°F for highs (1.3°F above normal) and 46.9°F for lows (3.5°F above normal). Precipitation: Autumn was dry and winter was off to a dry start until the upper level ridge broke down allowing a weak system to deliver some rain 22-24 Jan. This was followed by a major storm, which arrived late on 26 Jan. This storm stalled over the area and kept moderate to heavy rains falling through the morning of 29 Jan. Storm totals were impressive with Big Sur receiving 7.90” from 27 to 29 Jan. All stations in our local area received at least three inches of rain from this storm. Locally, daily totals were impressive: Ben Lomond, 5.03” on 27 Jan, Santa Cruz, 4.62” on 28 Jan, Big Sur, 4.45” on 27 Jan. Upper Monterey measured 3.25” on 27 Jan, which has only been exceeded three times since 1896 for stations within a couple miles of Upper Monterey. Record daily rainfall amounts are: 3.85” on 23 Dec 1955 at the original Monterey NWS Climate Station, 3.50” on 22 Dec 1922 and 3.32” on 21 Nov 1900 at Forest Lake Reservoir in Pebble Beach, with records covering 1896-1981. The 3.25” one-day total at Upper Monterey is the fourth highest value in 125 years. A normal January would have 3.91” of rainfall at our Upper Monterey site with measurable amounts on ten days. This past month, 5.88” was observed with measurable amounts on eleven days. Across our local area, January rain totals ranged from 3.46” at Seaside 9.53” at Big Sur. Precipitation for this rain-year (July 01 – June 30) improved dramatically with these January rains. Last month, local stations ranged from 19-40% of normal and now the range is 55-75% of normal. Wind: Strong winds were associated with the storm on 27-29 Jan, with the highest gusts in the area being 43 mph at NPS and 41 mph at the Monterey Peninsula Airport. Average winds for January were 5.4 mph at the Airport, and 8.2 mph at Fort Ord. 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 the last three months: Monterey Peninsula Airport Marina Mist Days (Normal) Fog Days Fog Days (Normal) (vis. <6 mi) (vis. <1/4 mi) (vis. <1/4 mi) November 2020 7 (8) 2 6 (4) December 2020 4 (6) 0 3 (2) January 2021 8 (6) 2 3 (2) OUTLOOK for average temperature and precipitation for Monterey, February through April 2021: NOAA’s Climate Prediction Center ENSO (El Niño / Southern Oscillation) discussion summary on 01 February 2021 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 expected to continue through the Northern Hemisphere winter 2020-21 (~95% chance during January-March), with a potential transition to ENSO-neutral during the spring 2021 (55% chance during April-June).” Links to some NOAA climate pages: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf https://www.cpc.ncep.noaa.gov/products/predictions/multi_season/13_seasonal_outlooks/color/churchill.php NOAA’s Climate Prediction Center seasonal outlooks for February through April 2021 indicate above normal, but not as confident, temperatures the central California coast and below normal rainfall. Normal temperatures and rainfall for Monterey for the next three months: Month Rainfall (inches) # of rain days Normal Max/Min. Temps (°F) February 3.22 9 61.2 / 44.6 March 3.10 9 62.0 / 45.1 April 1.51 6 63.3 / 45.9 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 January 2021 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. January 31 Jan date(s) Upper 10.66* / ( 39 ) Monterey 61.2 75 46.9 40 5.88 b 7.97 75% 27th 1.6 Monterey % ( 41 ) Airport 62.8 79 44.3 37 4.37 b 5.62 --- 25,27th 5.4 NPS 8.38# / ( 43 ) 63.0 79 41.8 36 4.28 d 5.50 66% 27th 2.4 Ft. Ord ( 39 ) 62.1 78 39.7 30 4.37 b 6.42 --- 26,27th 8.2 Marina 8.35 & / ( 32 ) 62.0 77 40.4 31 3.84 a 5.92 71% 19,25,27th --- Carmel Valley 65.3 81 40.3 34 6.72 8.23 --- --- --- Salinas 8.00 ∆ / 65.0 84 43.3 34 3.47 4.42 55% --- --- Carmel 61.7 77 45.5 39 4.91 6.16 --- --- --- Seaside 62.5 79 42.9 34 3.46 4.66 --- --- --- Pacific Grove 60.6 75 45.8 40 5.25 6.52 --- --- --- Big Sur 63.2 85 45.2 37 9.53 13.44 --- --- --- 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; Winds from Monterey Peninsula Airport (based on a 24-h period, ending at local midnight) .