Climatological Report (Monthly)
Issued by NWS
Issued by NWS
558 CXAK57 PAJK 160729 CLMASI NATIONAL WEATHER SERVICE JUNEAU AK 1121 AM AKST THU JAN 04 2024 ................................... ...THE SITKA CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2023... CLIMATE NORMAL PERIOD: 1991 TO 2020 CLIMATE RECORD PERIOD: 1944 TO 2024 WEATHER OBSERVED NORMAL DEPART LAST YEAR`S VALUE DATE(S) VALUE FROM VALUE NORMAL .............................................................. TEMPERATURE (F) RECORD HIGH 65 12/12/1944 LOW 16 12/25/2021 HIGHEST 53 12/29 50 3 LOWEST 31 12/18 19 12 12/19 12/27 AVG. MAXIMUM 45.8 41.5 4.3 AVG. MINIMUM 37.7 33.4 4.3 MEAN 41.7 37.5 4.2 DAYS MAX >= 90 0 0.0 0.0 DAYS MAX <= 32 0 1.8 -1.8 DAYS MIN <= 32 4 12.4 -8.4 DAYS MIN <= 0 0 0.0 0.0 PRECIPITATION (INCHES) RECORD MAXIMUM 16.55 1956 MINIMUM 2.25 1983 TOTALS 15.28 8.43 6.85 DAILY AVG. 0.49 0.27 0.22 DAYS >= .01 26 21.6 4.4 DAYS >= .10 24 16.1 7.9 DAYS >= .50 10 5.7 4.3 DAYS >= 1.00 4 1.9 2.1 GREATEST 24 HR. TOTAL 3.03 12/12 TO 12/12 DEGREE DAYS HEATING TOTAL 712 854 -142 SINCE 7/1 2392 3038 -646 COOLING TOTAL 0 0 0 SINCE 1/1 4 1 3 FREEZE DATES EARLIEST 10/08 LATEST 03/14 .............................................................. WIND (MPH) AVERAGE WIND SPEED 11.7 HIGHEST WIND SPEED/DIRECTION 43/160 DATE 12/12 HIGHEST GUST SPEED/DIRECTION 63/180 DATE 12/12 WEATHER CONDITIONS. NUMBER OF DAYS WITH THUNDERSTORM 0 MIXED PRECIP 2 HEAVY RAIN 1 RAIN 18 LIGHT RAIN 29 FREEZING RAIN 0 LT FREEZING RAIN 0 HAIL 0 HEAVY SNOW 0 SNOW 1 LIGHT SNOW 8 SLEET 4 FOG 17 FOG W/VIS <= 1/4 MILE 0 HAZE 8 - INDICATES NEGATIVE NUMBERS. R INDICATES RECORD WAS SET OR TIED. MM INDICATES DATA IS MISSING. T INDICATES TRACE AMOUNT. $$ While precipitation was generally above normal for Southeast Alaska, the bigger story was the warmer than normal conditions that all locations experienced. But in an age of a warming global climate, this should not be too surprising. Sitka experienced its 2nd warmest year on record, Juneau its 6th warmest, Ketchikan its 13th warmest, and Yakutat its 13th warmest year. To put this into perspective, the shortest of these records is Sitka and it goes back to 1944. The longest record, Yakutat, goes back to 1910. There were some notable cold spells across all of Southeast Alaska; the last week of February through the second week of March and then again at the end of October. However, when looking at the daily temperature ranges for each of the 4 climate sites plotted against the normal daily highs and lows, two things become obvious. First of all, overnight lows did not get down to or below normal nearly as often as daytime highs rose to above normal vlaues. Secondly, the degree to which daily highs were higher than normal was significantly greater than the degree to which overnight lows were lower than normal, meaning that the average daily temperatures were skewed warmer than normal. Also not surprisingly, daily high temperature records were set 21 times through the year with at least one event at each of the climate sites. Conversely, only 2 record low temperatures were recorded during the year; once at Juneau and once at Sitka. Interestingly, as the La Nina winter of 2022-2023 ended, many were expecting to see below normal temperatures for the season. In fact, only Ketchikan closed out the winter with below normal temperatures. This was due in large part to a very warm January across Southeast Alaska. The beginning of Spring featured heavy snow on the 1st of March and then again at the middle of the month, but very little after that time. Precipitation totals for the month were, however, below normal and the excess snow was a result of colder than normal temperatures. Temperatures finally trended above normal by May and what followed was some excellent summer in spite of precipitation remaining above normal through June. The summer ended in August with a glacially dammed lake release at Suicide Basin. This release produced an all time record flooding event on the Mendenhall River. Two homes were completely destroyed when they fell into the river due to riverbank erosion and several other structures were condemned due to the river undercutting their foundations. The fast flowing flood waters altered the path of the riverbed, dramatically so in some locations. Fall began with much above normal precipitation from several atmospheric rivers that impacted the region. Moderate flooding occured on Jordan Creek near the Juneau airport and Sitka came close to recording a new precipitation record for the month. A very strong Autumn storm affected all of Southeast Alaska in the days before Thanksgving. High winds occured across all of Southeast Alaksa with snow over the northern half of the Panhandle and rain to the south. The combination of wind and snow produced blizzard conditions in the Juneau area. The strong winds and heavy rain also resulted in tragedy when a deadly landslide struck the community of Wrangell in a scenario all too similar to the fatal landslide that occured in Haines in 2020. By the beginning of the Winter and the end of 2023, a strong El Nino had developed and this was reflected in monthly average temperatures from 4 to 6 degrees above normal at the primary climate sites. Not surprisingly, even though precipitation was once again above normal, snow totals were below normal. Fritsch $$