October 2010 Saint Cloud Weather Summary

Saint Cloud October 2010 Weather Summary  

October 2010 was primarily a warm and dry month. The average temperature at the St. Cloud Regional Airport was 49.5°F, 4.2°F warmer than normal. The October rainfall was 2.59 inches, .35 inch more than normal. However, these totals were the result of two drastically different weather patterns.

October 1-22: Very Warm and Bone Dry

For the first 22 days of October, St. Cloud finished 27 straight days (since September 26) without any measurable rainfall, the longest streak since April 1-29, 1987. The longest streak without measurable rainfall in St. Cloud history was 43 straight days on October 13-November 24, 1912. There are periods of more than 50 days in the St. Cloud recorded history, but precipitation measurements weren't as accurate and snow depth was not recorded reliably. There has only been one October in St. Cloud records without any measurable precipitation --that was in 1895.

Ironically, the dry period was just long enough to allow the extraordinary September rainfall in southern Minnesota to move through the Minnesota River, producing flooding early in the month, and have the rivers recede.

The dry weather came with extraordinary warmth during the first two weeks of October. Temperatures averaged 55.8°F (avg. high 70.3°F, avg. low 41.2°F), which would have ranked as the 4th warmest October had it persisted all month. These readings would have been more typical of mid-September and included a record high of 84 degrees on October 8. Then, more seasonable weather moved in for October 15-22, during which the average temperature was 46.6°F, near normal for mid-October, but still featuring several days with 60+degree highs. Through October 22, the average October temperature was 52.5°F, still warm enough to crack the 10 warmest Octobers .

The Other October (23-31): Two Major Storms and A Lot Colder

The dry and frequently warm weather pattern changed drastically for October 23-28. Two major storms had a direct hit on Minnesota, dumping a total of 2.59 inches of rain on St. Cloud, more than the normal October precipitation of 2.23 inches. The first storm on October 23 and 24 produced nearly half an inch of rain, but the record-breaking storm of October 25-27 (more below) produced two daily precipitation records on both October 25 (0.61 inch, topping the 0.50 inch, set in 1956) and October 26 (1.44 inches, topping 1.33 inches, set in 1941). And, St. Cloud did not get the most rain from this storm: Askov got nearly 5 inches of rain in two days, producing flooding problems in tributaries of the St. Croix River.

Temperatures during the stormy period were much colder due to the persistent clouds during the rain and the colder air brought in behind the second storm. The temperature during October 23-31 averaged 42.4°F (avg. high 45.2°F, avg. low 31.2°F), highs typical of the first week of November.

How Was The October 26-27 Storm Unusual?

The lowest central pressure from this storm was recorded at Bigfork and was 955.2 mb (28.21 inches) at 5:13 PM CDT on October 26 . This has been slightly adjusted upwards, since all pressures are reduced to sea level. The correction normally applied at Bigfork is slightly different than that applied at the long term weather stations, so the original report of 28.20 inches was modified to bring it in line with those long term records.

That is the new pressure record for the State of Minnesota, breaking the old record of 962.7 mb (28.43 inches) at Austin and Albert Lea, set during the November 10, 1998 storm. Even though the central low didn't pass through Wisconsin, a record low pressure was set from this storm at Superior (961.3 mb; 28.45 inches) . Record low pressures were set for International Falls, LaCrosse, and Duluth with the second lowest pressure ever seen in the Twin Cities .

However, this storm did not set a record low pressure for a cold season storm in the Continental US. The lowest pressure ever seen in the US was 892 mb (26.34 inches) during a hurricane in the Florida Keys in 1935. Outside of a hurricane, the lowest pressure in the US was 927 mb (October 25, 1977) in Dutch Harbor, Alaska. As I noted during our storm, this storm was typical of the mid-ocean cold season large storms. Having the central pressure in the 950's isn't that unusual. It's very unusual to have a storm that strong develop over a land mass.

There is some debate about what storm holds the record for the Continental US. One storm suspected of having the lowest pressure produced a central pressure of 951.6 mb (March 3, 1914) on the coast of New York, but this hasn't been confirmed by the National Climatic Data Center. The lowest confirmed pressure in the continental US outside of a hurricane was 955.0 mb (28.20 inches) in two storms, one in New York in 1913 and one on Block Island off Rhode Island in 1932. Both of these pressures were slightly lower than the Big Fork measurement.

It appears that, for the center of the continent (between the Rockies and the Appalachians), our storm's central pressure may have set a record, but that's getting really picky.

You can find a nice wrap-up of this storm on a special page from the National Weather Service in Duluth . Also, the Minnesota State Climatology Office has a summary of information from local and national statements.

• Wind Gusts Produce Major Power Outages

The large pressure difference between the center of the storm and its surroundings produced huge wind gusts not related to thunderstorms. I n the Dakotas and Minnesota , the top gusts were 70 MPH in Union Center, SD, 65 MPH in Georgeville and Mehurin, MN, and 64 MPH in both Sisseton, SD and Fargo, ND.

The widely reported top wind gust (50 MPH) in St. Cloud is wrong. Winds gusted to 58 MPH at 9:35 PM on Tuesday night. This was not as strong as the 77 MPH gusts at Duluth and 64 MPH gusts in St. Cloud observed during the storm that was the previous low pressure holder, November 10, 1998 (see summaries from Minnesota State Climatology Office and NWS Duluth ). At its worst, about 50,000 electric customers lost power in Minnesota.

There were two areas where at least 4 inches of snow fell over a wide area. One was from eastern North Dakota into western Minnesota , which included 4 inches in Pelican Rapids and Rothsay plus 3.5 inches at Fergus Falls. There were 6 inches of snow in parts of eastern North Dakota. The other was across northeastern Minnesota , with the heaviest amounts along the Gogebic Range just off the North Shore. Twig had the most snow (9 inches) with 8 inches in Adolph, 7.7 inches at the Duluth International Airport, and 7.1 inches in Two Harbors. In Brainerd, there were 3.8 inches of snow with 3 inches on the grass and an inch on pavement.

There were higher winds reported from this storm, but they were in thunderstorms that raced to the south and southeast of the storm along the warm sector . Along the cold front , there were strong thunderstorms with severe weather ( over 350 severe weather reports ) from Illinois to western New York and southward to Mississippi. There were at least 4 tornadoes , plus straight line damaging wind outbreaks in the Chicago area alon e. At least two people were injured in a tornado near Kenosha, Wisconsin. Another person was injured when a hog barn collapsed on him near Greenfield, Indiana. Unfortunately, t he media and bloggers have tried to name this storm a Chiclone (Chicago+cyclone), despite the center being in Minnesota and the effects being spread throughout the eastern two-thirds of the country.

Once Dry St. Cloud Now Wet

For the year, St. Cloud's precipitation is now 30.37 inches, more than three inches higher than the annual average of 27.27 inches . Since 1993 , there have been only two years (2002 and 2005) with more than 30 inches of precipitation. To crack the 10 wettest years, however, we'd need another 5 inches of precipitation.

Before the storms, however, the warm and dry weather allowed fields to dry out considerably. US Department of Agriculture statistics showed that the surplus moisture, which covered 72% of farms in late September , had dropped to 6% just before the late October storms . This allowed harvests of soybeans and sugar beets to be nearly completed and the corn harvest to be well ahead of schedule.

Frost came late to St. Cloud, although there were some near misses to our north in September. The first frost at the St. Cloud Airport was on October 3, much later than the average date of the first frost (Sept. 22). The first hard freeze (first period of at least 4 hours with the temperature of 26 degrees or colder, but definitions vary) didn't happen until October 28, ranking among the latest 10% of years. Of course, the well-publicized first frost in the Twin Cities didn't occur until October 28, ranking among the 10 latest first frosts on record.

Winter Forecasts Now Out, But Are They Any Good?

Several long-range forecasters have indicated a decent chance for a relatively cold and snowy winter. The National Weather Service official winter forecast has a decent chance of a snowiest and colder than normal winter in North Dakota with less chance of the same over Minnesota. This is based on the colder than normal temperatures in the eastern tropical Pacific, the so called La Nina pattern. Note, however, that last winter was supposed to be warmer than normal due to the warm cycle in the tropical Pacific. However, Minnesota was quite cold through December and the first week of January before warming a bit. So, these forecasts should be viewed with skepticism.

     October 2010 Statistics