Note that the color scale is different on the two maps. All stations with a value greater than Fairbanks' 226.6 (rounded to 227) are shown in blue dots. Figure 3 shows the stations used in the Analysis. Therefore, I used an average of five stations to generate a single Fairbanks value of 226.6 sub-freezing days.įigures 1 and 2 show the number of days with subfreezing temperatures for Alaska and for the entire U.S. However, the Fairbanks Airport #2 station records 237.1 sub-freezing days. For example, the number of sub-freezing days per season at the airport's official station is 222.7. Specifically, I was interested in how Fairbanks compares to other places in Alaska and the Lower 48.Īs the analysis unfolded, it became apparent that the Fairbanks International Airport station's values did not appear representative of the greater Fairbanks area. Therefore, I thought it would be interesting to look at 1) the number of days per season with sub-freezing temperatures and 2) the length of time between the average first freeze and the average last freeze. In a few weeks, stations in Alaska will be approaching the date at which freezing temperatures are no longer expected. Warmer than average conditions are definitely favored in most Alaska locations in El Niño summers, and dry conditions are more common than wet from Anchorage to Nome, Kotzebue, and Barrow but elsewhere (including in Fairbanks) the precipitation patterns are mixed.Įvery so often I do a quick climate analysis for a blogger in Houston, Texas, and one of the things that came up earlier in the winter was the frequency of freezing temperatures down there. The maps below show the results, with the height of the columns corresponding to the number of years in each category. I then examined how many of these years produced above-normal, near-normal, or below-normal temperature and precipitation in June and July, based on three equal divisions (terciles) derived from the 1951-2010 historical data. To do this, I looked at the June-July period as representative of high summer, and I picked out the top 10 years for El Niño conditions, based on a bivariate ENSO index that I feel is a good measure of the El Niño/La Niña (ENSO) phenomenon. So I thought it would be interesting to look at the strength of the connection between El Niño and summer temperature and precipitation in Alaska. The length of time between 40☏ days is longer at Fairbanks and the length of time between 60☏ days is longer at Anchorage.Īn article a couple of weeks ago in the Alaska Dispatch discussed the potential for El Niño conditions to develop in the tropical Pacific this summer or fall, and speculated that another warm, dry summer might result if El Niño does in fact emerge. Interestingly, for both cities, the 50☏ time is about the same over the long term. For comparison, Figure 3 shows a chart of the annual number of day between the three temperature thresholds in Anchorage. Figure 2 shows a chart of the annual number of day between the three temperature thresholds in Fairbanks. Figure 1 shows the number of days between the three temperature thresholds. If Fairbanks makes it to the normal date, they will (slightly) exceed the normal length of time between 60☏ days. To reach the normal value would require another month of sub-50☏ days. Through March 29th, there have been 152 days since the last 50☏ day in the Fall. Looking ahead to the first 50☏ day, it normally occurs on April 3rd. This is more than 40 days less than the 1981-2010 normal value. There were 71 days between the last 40☏ day in the Fall and the first 40☏ day of the Spring. In fact, there have been quite a few 40☏ days in the last week or so. Fairbanks has already experienced their first 40° day of the season.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |