SUMMARY of the April 2021 WEATHER on the MONTEREY PENINSULA General: Weather During April 2021 Was Cool and Dry, a Trend Which Started in February 2021
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Department of Meteorology Naval Postgraduate School Monterey, California 93943 SUMMARY of the April 2021 WEATHER ON THE MONTEREY PENINSULA General: Weather during April 2021 was cool and dry, a trend which started in February 2021. Winds and fog were seasonable. Temperature: Temperatures in April at our Upper Monterey site were somewhat remarkable, with just two maximum temperatures above 70°F. Following a warm 81°F on 01 April, daily highs languished in the upper 50s°F to low 60s°F for most of April. Only a 68°F reading on 18 April and 73°F on 28 April offered respite from the coolness. For the month, Upper Monterey registered an average high of 59.0°F, 4.7°F below normal and an average low of 46.7°F, 0.8°F above normal. Highest temperature at our Upper Monterey site was 81°F on 01 April and lowest was 44°F on 26 April. One daily record was the 57°F warm minimum on 01 April (previous record was 56°F in 2011). In the local area, highest readings were 87°F at Salinas, and 85°F at Fort Ord and Big Sur (all on 01 April). The cool spots were Big Sur (34°F on 04 April) and Carmel Valley (35°F on 14 April). Marina reported two days with light frost (normal is one), on 26 and 27 April. Normal last day of frost for Marina is 25 March (see Table of Comparative Weather Data for Stations contributing to this summary, and graphic of daily temperatures and rainfall from Upper Monterey, below). Precipitation: Much like February and March, below normal precipitation was recorded during April at Upper Monterey, where 0.11” was measured on three days. Normal for April is 1.51” falling on six days. This is the fourth driest April since 1949. Rain-year totals now range from 43 to 58% of normal for local stations and we have dropped into the severe drought category. An average Feb-Apr rainfall total at Upper Monterey would be 7.83” but for 2021 just 2.91” of rainfall has been recorded for these three months. This total ranks as the ninth (tied) driest Feb-Apr in 72 years. Feb-Apr rainfall totals (inches) recorded since 1949 at Upper Monterey: Wind: Highest wind gusts recorded in the local area were 27 mph at Fort Ord on 04 April and 25 mph at Monterey Airport on 13 and 20 April. Average winds for March were 7.1 mph at the Airport, and 10.2 mph at Fort Ord, a little less than seasonal average. 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) February 2021 6 (6) 2 3 (2) March 2021 2 (7) 0 0 (3) April 2021 6 (8) 1 3 (2) OUTLOOK for average temperature and precipitation for Monterey, May through July 2021: NOAA’s Climate Prediction Center ENSO (El Niño / Southern Oscillation) discussion summary on 03 May 2021 reports “La Niña is present. Equatorial sea surface temperatures (SSTs) are below average over the east-central to eastern Pacific Ocean. The tropical atmospheric circulation is consistent with La Niña. A transition from La Niña to ENSO-Neutral is likely in the next month or so, with an 80% chance of ENSO-neutral during May-July 2021.” 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 Seasonal outlooks from NOAA’s Climate Prediction Center for May through July 2021 indicate above normal temperatures for the central California coast and equal chances of normal rainfall. Normal temperatures and rainfall for Monterey for the next three months: Month Rainfall (inches) # of rain days Normal Max/Min. Temps (°F) May 0.49 4 64.5 / 48.1 June 0.20 3 66.3 / 50.6 July 0.07 2 67.8 / 52.1 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 April 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 north 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. April 30 Apr date(s) Upper 18.74* / ( 18 ) Monterey 59.0 81 46.7 44 0.11 b 10.88 58% 25th 1.7 Monterey % ( 25 ) Airport 63.0 84 49.1 45 0.01 b 7.57 --- 13th,20th 7.1 NPS 15.15# / ( 21 ) 62.0 82 45.8 41 0.02 d 7.93 52% 25th 3.7 Ft. Ord ( 27 ) 59.8 85 44.0 39 0.03 b 8.29 --- 4th 10.2 Marina 14.76 & / ( 23 ) 60.5 81 45.9 39 0.07 a 8.05 54% 9th,20th --- Carmel Valley 68.7 84 41.8 35 0.07 10.72 --- --- --- Salinas 13.46 ∆ / 65.1 87 48.5 43 0.04 5.75 43% --- --- Carmel 58.7 74 46.8 41 0.05 8.88 --- --- --- Seaside 58.3 81 46.1 40 0.07 6.77 --- --- --- Pacific Grove 58.4 77 47.3 43 0.00 9.01 --- --- --- Big Sur 66.3 85 42.4 34 0.06 17.56 --- --- --- 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, & = 37-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) .