With the significant temperature differences between March, 2012 and what has been recorded this March, comparisons are inevitable. One statement I have read several times was to compare last year to this year by stating “last March was more than twice as warm as this year”. A year ago, Fargo Moorhead recorded several days in the 60s and 70s, this year, mainly 20s, so just looking at the numbers, you would think such a statement would be factually correct, yet, it is not.
Surface temperature readings in the United States are given in degrees Fahrenheit. If we used the Celsius scale last March temperatures would have been in the 20s and this year in the -0s, obviously not “twice as warm”. Temperature scales use arbitrary numbers to represent the measurement of the amount of heat present.
Therefore, representing temperature differences in fractional terminology is not correct unless your starting point is absolute zero and you state the scale you are using
January 2012 continued our stretch of months with above average temperatures. Last month was our 8th straight month with temperatures above the 30 year average with most of that stretch finishing well above average. The average temperature in January was 19.6 degrees which tied 1931 for the 4th warmest January on record. That is 10.3 degrees above average for the first month of the year.
Last month was the first January that finished with an above average temperature since 2007. In fact, 7 out of the past 9 Januaries finished below normal perhaps adding to the overall pleasant feel of the month. When compared to January 2011 the difference is striking. Last year the month recorded an average temperature of just 3.2 degrees, which means, on average, each day of January this year was over 16 degrees warmer than what we recorded last year.
The warmest temperature in January was a 55 degree high on January 5 which was also the warmest temperature on record for the month.
Just a weeeee bit chilly in Alaska this morning. The red numbers are the air temperature in ˚F. Green numbers will be the Dew Point where it is warm enough to be recorded. Coldest Day in Fairbanks since 2006, which is when we had our last warm winter (no coicidence).
2011 started off cold, especially January through May as all five of those months finished with below average temperatures. Including the mild month of June, the first half of 2011 finished as the 52nd coldest on record. That warm up that started in June continued through the rest of the year as the 2nd half of 2011 narrowly beat out 1931 as the warmest such period on record.
That end of year warm surge push the average temperature from 4 degrees below normal on Memorial Day, to 0.7 degrees above average on December 31. Although, 0.7 degrees may not sound like much, with an average temperature of 43.1 degrees, 2011 finished as the16 warmest year on record. Our current 30 year average annual temperature is 42.4 degrees in Fargo Moorhead.
The warmest years on record locally were in 1987 with an average temperature of 46.4 degrees and 1931 when the average temperature was 45.9 degrees.
Several individuals have inquired in recent weeks asking if the oil in the Gulf of Mexico will impact the weather or hurricane development. More specifically will the oil change the albedo (amount of sunlight reflected) of the water, therefore causing an increase in temperature. This warming of the water would in theory increase the strength of approaching hurricanes and perhaps increase rainfall amounts in the United States.
Contrary to popular perception, the oil does not make the surface of the water darker and therefore allowing the water to absorb more sunlight mainly because the Gulf of Mexico is already very dark and absorbs more than 90% of the sunlight that strikes it. There certainly could be some very small areas where the oil may raise the temperature beyond what would have otherwise occurred, but only in periods of light wind and small wave action. Therefore, as a whole, the Gulf will not have an increase in temperatures because of the oil leak.
Our recent stint of very mild mornings may have you thinking that below zero mornings are a thing of the past. The average last day with a low temperature below zero is March 11 in Fargo Moorhead. In the past two decades that day has fluctuated from February 16, 2000 to March 26, 1996. Last year the last below zero day of the season was on March 12 which was the day after we recorded one of the latest sub-zero highs on record with a high of -1 degrees on March 11.
The latest below zero day recorded was during the first year of record keeping back in 1881. That year the last below zero reading occurred on April 4 and the earliest we have recorded our last negative temperature of the season was on January 24, 1987.
My hunch is we will observe another below zero morning this season, but I would like to be wrong.
It usually takes a stretch of several days with both the high and the low temperature remaining below freezing before most of the area lakes and ponds will begin to freeze over. But so far this season, that type of weather has been nearly absent and therefore most bodies of water are still ice free.
Previous to this year, the latest date achieved without recording a freezing or sub-freezing high occurred on November 27, 1999 with the long-term average being November 5. To date, the lowest high temperature officially in Fargo Moorhead this season was a 34° reading on November 26, so we have now surpassed the record by making it through the entire month of November without a sub-freezing high temperature. We average 98 days per year with a high temperature at or below 32 degrees and it appears Wednesday will be the first of many such days in our upcoming winter season.
The first half of November was the 5th warmest such stretch on record. It was a quick turnaround from the seasonally cold weather in October. In fact, the first half of October was the coldest on record which followed the 2nd warmest September since 1881. Our area has certainly been on the proverbial rollercoaster for the past several weeks.
This shifting of temperature extremes has not only been felt locally, but throughout much of the northern hemisphere. The upper-level wind flow has been in a strong meridional flow pattern for the past several weeks. This is a flow pattern where only small segments of the jetstream are flowing from west to east, but instead the flow has several north/south components. This allows unseasonally cool or warm temperatures to slowly transition around the northern hemisphere.
It appears we will be switching to colder again as we approach Thanksgiving with the possibility of a storm system moving along the transition zone.
Current Northern Hemispheric 500 mb chart:
With an average high of only 46 degrees and an average low of 27 degrees it takes a day well above average to make trick-or-treating an event where a jacket and mittens are not a requirement in our area. Today looks to be another typical chilly Halloween, but not as cold as some.
This decade has recorded three years (2002, 2003, 2006) with high temperatures only in the low 30s, all of those years rank in the top 15 coldest since 1881. In 2006 there were even snow flurries in the air during the evening hours. The last year with measurable snow on Halloween was back in 1995 when one inch of snow fell. But Halloween has also had its share of mild days. Back in 1999 it hit 74 degrees and that was followed by two more nice Halloweens in 2000 (when a thunderstorm moved through during the evening) and 2001 when we hit 60 degrees.
The average high temperature in Fargo Moorhead is now in the upper 60s. The last day with an average high of 70 degrees was on September 16. An average daily maximum of 70 degrees will not occur again until May 16, a stretch of 242 days. If that depresses you a bit, the earliest 70 degree day in a year occurred on March 17, 1968 and our average first 70 degree day of spring occurs on April 18, so we rarely go that long between 70 degree days.
Plus, in most years an occasional high at or above 70 degrees will continue through the middle of October and on rare occasions even into the very early part of November. But sadly for most people, our average high temperature drops approximately one degree every other day and by Halloween the average high is 46 degrees which means our last 70 of the year will soon be a memory.