March and April Record

This past March, you will likely recall, was the warmest on record.   The previous warmest March was set back in 1910.  April 1910 was also a mild month and currently ranks as the 26th warmest April on record.  The combination of an extraordinarily warm March, followed by a mild April made the period from March 1 through April 30, 1910 the warmest such period on record.

That is, until this year.  With the record breaking March and an April that finished several degrees above average, the past two months finished 1.1 degrees warmer than the same period in 1910 to set a new record.  With a record breaking March, a record breaking March and April combination, could we in turn end up with the warmest spring on record this year?  The record warmest spring occurred in 1977 with an average temperature of 49.3 degrees.

To best that record, this month would have to average 57.9 degrees, which would only be 0.8 degrees above average, meaning we do have a realistic shot of breaking the spring temperature record this year.

Fear of Ice Death was Greatly Exaggerated

Back in September 2007 when the Arctic sea ice reached the minimum extent recorded since 1979, it generated quite a bit of news coverage.  Many so-called experts went on to predict that the Arctic Ocean would be ice free during the summer in the upcoming years with some predicting the Arctic could be ice free by the summer of 2012.

Arctic sea ice is currently running either at or above average depending on which source you use (there are several countries and agencies that keep track of ice conditions around the world which differ slightly from each other).   With sea ice currently running near or above the long-term average, plus, with the melt season in the Arctic starting a few weeks later than usual this year, the odds that the Arctic will come anywhere near ice free this summer are virtually zero.

Instant communications and a 24 hour news cycle can often make the normal seem abnormal, yet, we all need to remember that sea ice has fluctuated greatly on decadal time scales since the last ice age and there is no reason to think that is going to change.

Too Early Too Late

After a very mild winter, parts of the northeastern United States were hit by a late season snow storm earlier this week.  The major cities along the coast recorded rain and strong wind, but interior regions experienced a wet sloppy snow.  The heaviest snow fell along the spine of the Appalachian Mountains along the West Virginia/Virginia border through western Pennsylvania into western New York.  Parts of Vermont, New Hampshire and Maine also picked up some snow from the event, but it was generally light.

The warm temperatures this spring in that area allowed most trees to become fully leafed out before the storm hit and the heavy wet snow destroyed thousands of trees as the weight of the snow on those leaves was just too much for many trees.  Unfortunately, that same area had a very early snow event last October just before Halloween that also caused significant tree damage as the leaves had not fallen before that storm.

The combination of those two storms in turn made the “year without a winter” a memorable one after all.

Reversed Months

In Fargo Moorhead, the average temperature in April is 16.4 degrees warmer than the average for March.  Although the exact difference will vary a few degrees from city to city, most locations in the Midwest and upper Great Plains will have a similar difference between those two months.  March you will recall was the warmest on record for a large portion of the lower 48 states.  Many cities recorded temperatures between 10 and 20 degrees above average.

Chicago for instance, recorded record breaking temperatures last month with an average temperature of 53.5 degrees which was 15.6 degrees above average.  Although the temperature this month has continued to above normal, April will likely finish cooler than March in Chicago for only the 2nd time on record.

Locally, April is running slightly warmer than March and the warmer temperatures earlier this week will guarantee that 2012 will not be the first year when a March finished warmer than April, although, it will be

2012 Hurricane Season

Although very few tropical storms or hurricanes have struck the United States n recent years, the overall number of systems in the Atlantic Ocean has been well above the long-term means during this time period.   A combination of warmer than normal sea surface temperatures in conjunction with favorable upper-level winds has been the attributing factors to these increased numbers.

There are some indications that the 2012 hurricane season may be quieter than in recent years.  The Atlantic Ocean, like the Pacific, goes through a slow oscillation between warmer and cooler water temperatures.  Sea surface temperatures this year are expected to be near or even slowly below normal, a significant departure from recent years.  Plus, a weak El Nino may develop by the end of the summer, which tends to produce unfavorable winds for hurricane development in the Atlantic.

All of this is conjecture at this point, but most hurricane experts expect fewer storms this year than in the recent past.  Yet, as we learned in 1992 with Hurricane Andrew, it only takes one storm.

 

Palm Sunday

April 11, 1965 was Palm Sunday.  That day at least 21 tornadoes were recorded with 17 of those being rated as a F3 or higher.  By the end of the day 271 people lost their lives with over 3000 more injured from those tornadoes.  It is known as the Palm Sunday outbreak and at the time it was the 2nd worst outbreak known and even today, it ranks as the 4th deadliest outbreak on record.

That horrific day led to significant changes to the warning system.  Today, tornado watches are issued when conditions are favorable for tornadoes to develop, but back in 1965, tornado forecasts were issued that research found were misunderstood by many.  Plus, the limited radar coverage at the time and poor communication of where the tornadoes were meant the storms came as a surprise in many areas.

The current nearly instant communications between the National Weather Service and the media, better radar coverage and system of severe weather watches were all improvements that came from lessons learned from that fateful day.

Record Alaska

Last weekend Anchorage,Alaska recorded nearly 5 inches of new snow.  Certainly not unusual for the time of year, but that additional snowfall was enough to bring their seasonal total to 134.5 inches which made the 2011-2012 snow season the snowiest on record.  The old record was 133.6 inches recorded during the winter of 1954-1955.   The current 30-year average snowfall for Anchorage is 74.5 inches.

It was not onlyAnchorage, but most of the other coastal cities inAlaskarecorded an extraordinarily snowy winter.  Not only was the snow plentiful, but so was the cold.  Whereas most of the lower 48 states have experienced very mild conditions in recent months, Alaska on the other hand has been recording mainly below average temperatures.

That cold air has also cause another problem, sea ice.  Although good sea ice statistics only go back to 1979, the sea ice this season did set a record for aerial extent around the state slowing down the opening of shipping routes in the Bering Sea.

It Was Close

Regular readers of this space will likely remember that March 1910 was by far the warmest March on record until this year.  March 1910 was not only warm locally, but throughout much of United States just like this year.  As last month was coming to a close many people, including myself, were curious if March 2012 would best March 1910 as the warmest on record in the lower 48 states.

According to analysis released earlier this week from the National Climatic Data Center, last month did end up ranking as the warmest March on record for the lower 48 states.  The national average temperature was 51.1 degrees which was 0.5 degrees warmer than March 1910.  Considering the massive urban build up in the past 102 years and that most stations now have a warm urban heat island bias, that result was not totally surprising.

Locally, North Dakota as a whole, recorded the 2nd warmest March on record and in Minnesota the month ranked as the warmest.

 

Rising Spring

The current 30 year average temperature in April is 44.2 degrees.  What was amazing about last month’s record breaking temperatures was that the average temperature in March was 41.6 degrees, almost as warm as the average for this month.  Plus, the average temperature last month was actually warmer than the monthly average high of 36.3 degrees.

Although it is extremely doubtful that the rest of spring will bring with it temperatures so far above seasonal normals, with an increasingly higher sun angle and the lack of snow, the average temperatures do climb rapidly in the spring.  The average temperature in March is 27.8 degrees, in April 44.2 degrees, and in May the average climbs to 57.1 degrees.  The average temperature is simply the high temperature plus the low temperature divided by two.

The temperature most people tend to notice is the afternoon high.  That average increases from the low 50s today to 73 degrees by the end of May. What this means is that eventually, even temperatures that are below average will still be considered mild.

Forecasting the War

At a recent speaking engagement I had the opportunity to have a brief but fascinating conversation with a World War II veteran that was a meteorologist in the Pacific Theatre during the war.  Even with modern technology, forecasting in thePacific Oceanis difficult because of the lack of weather information due to the shear size involved and the few reporting stations.

Satellite data in combination with computer modeling makes for respectable forecasting in the modern era, but of course in the 1940s neither was available.  But the combination of some pilot reports, station reports from ships and islands and good old fashioned experience made for a useful 24 hour forecast.

I often tell students that by simply paying attention to the weather, especially the sky, you can make a respectable forecast for the next day.  The clouds tell a story, their structure, type and movement give hints to the future; you just need to look up.  Sometimes we forgot that old techniques can be more valuable than looking at a computer screen.