November 2009 and Fall 2009 Saint Cloud Weather Summary

Third Warmest November

    The "If you don't like the weather, wait a month" weather pattern continued in November 2009. St. Cloud followed up its 9th coldest summer with its 11th warmest and third driest September, the 9th coldest, 10th snowiest, and third wettest October and now its third warmest November ever. The average temperature at the St. Cloud Regional Airport was 39.3°F, 10.5°F warmer than normal. The average conditions for the month (high of 49.5°F, low of 29.2°F) were typical of October 28. This also marked eight out of the past nine Novembers.being warmer than normal.

    Nine daily record warm temperatures were set during November, including two days during November 11-13 with an average temperature near 50 degrees, and three straight days with record warm lows during November 22-24. Twenty-nine of the 30 days had temperatures warmer than normal with 17 days more than 10 degrees warmer than normal. Only November 3 had a colder than normal temperature. While there were no high temperature records set, the last day with a 50-degree high was November 23, within the latest 10% of the last 50 degree high of the season.

    Most of November was spent sitting at the second warmest November. Between November 1-24, the average temperature was 41.1°F, within 0.7°F of November 2001, the warmest November ever. However, cooler weather over the last 6 days knocked the average temperature below the 39.5°F of 1899.

Reversal of Steering Winds Changes From Cold October Pattern

    The reason for the reversal from October's chilly conditions was a switch in the steering winds. The steering winds at 18,000 feet on November 15 from HPC's Daily Weather Map shows a low over the Colorado-New Mexico border. This means that the winds from the southern Rockies through most of the US are blowing parallel to the brown lines from southwest to northeast. That means that our weather is tending to come from the American Rockies. Air traveling that route has lost most of its moisture as it climbed the west side of the mountains, then warms as it sinks on the east side. That creates a lot of warm air with very low dew points. So, temperatures over Minnesota on that day climbed well into the 40's for highs and held in the 20's for lows. The southwest steering winds also kept any cold air trapped in northern Canada, keeping it from getting here.

Warmth Spread Across Minnesota and US

    The November warmth was spread throughout Minnesota as Minneapolis-St. Paul recorded its second warmest November, onInternational Falls had its second warmest November on record, and Duluth and Eau Claire had their 3rd warmest November. Most Iowa stations had one of their 10 warmest Novembers as was true in Missouri. I wouldn't be surprised to see this November rank among the warmest nationally, but that will take a week to compile the statistics.

St. Cloud's Smallest Temperature Difference Between October and November

    Want to brag about the strange weather reversals? November's warm average temperature of 39.3°F was within 1.6°F of October's cold average temperature of 40.9°F. That's the smallest difference between October and November temperatures in St. Cloud records, which date back to 1881. The previous record was 3.5 degree in 1917 and 4.0 degrees in 2001, which had the warmest November ever. In all other years, November has been at least 6.4 degrees colder than October. It's also the first year that St. Cloud had a warmer November average high (49.5°F) than October average high (47.7°F). Every other year has had the October average high at least 4.9 degrees warmer than the November average high.

Many points in the US should achieve this rare feat, given that October was the third coldest October nationally and November has been very warm through much of the country.

Dry November Allows Farmers to Catch Up

    Despite some episodes of fog and drizzle, the warm weather mainly was dry. The total November precipitation at the St. Cloud Regional Airport was 0.35 inch, 1.19 inches below normal. That dryness pushed the April-November rainfall deficit back over two and a quarter inches (precip: 21.27 inches; normal: 23.63 inches). However, the dry conditions were crucial for agriculture. The dry conditions without a snow cover allowed crops extra drying time so that they could be harvested.

    The last Minnesota Drought Report from the State Climatology Office shows a long term drought in the St. Paul area to Taylors Falls and the driest conditions in 2009 being in north central Minnesota. Stearns County remained one of the few wet areas in central Minnesota with above normal growing season rainfall, but the wettest conditions were in the Upper Red and Minnesota River Valleys. That's the reason that the Red and Minnesota Rivers show streamflow in the highest 10%, according to the latest USGS WaterWatch. The dry November hasn't hurt streamflow much in eastern Minnesota as most of the St. Croix and the Upper Mississippi Valley have near normal streamflow.

Nearly No November Snow, Similar to Recent Years

    There was only a trace of snow recorded in November. That marks the 13th November that either a trace or less of snowfall was observed. The normal November snowfall is 8.9 inches, but this can be very streaky. There has only been one November since 2004 with more than an inch and a half. However, ten of the 16 Novembers during 1988-2003 had at least 10 inches of snow.

Change to December Marks Major Weather Pattern Change Again

    However, our "fun" is about to end. Let's look at the forecast 500 mb chart over North America for Tuesday evening. Tuesday night). Note the steering winds over western Canada blowing north to south on the eastern flank of a strong high pressure system over Alaska. This high is already developing now and is expected to intensify over the next week, steering cold air from north central Canada into the Northwestern US. In fact, this particular outbreak will produce a rare surge of cold air into the populated valleys of Washington state and Oregon. Fortunately, it hasn't been really cold in northern Alaska with high temperatures generally above zero right to the Arctic coast and low temperatures colder than zero relatively hard to find for this time of year. This, however, should be cold enough to keep temperatures at or a bit colder than normal for the next week to 10 days.

    Where's the really cold air? The Unisys air mass map of the Northern Hemisphere shows that the coldest air is situated over Russia and interior Siberia. That air is even colder than any air over the North Pole. This high will make it harder for the air over Siberia (temperatures, unfortunately in nearly unreadable light blue, have been running in the minus 30's and 40's on the National Ocean Center's Pacific Surface Map) to move into North American, limiting how cold we can get for at least the next week.

    Storms are harder to predict far in advance, but this generally dry flow will make it hard to get widespread significant snowfall, despite the fact that we got the snow that stayed for the rest of the winter by December 6 last winter and by December 1 in 2007-2008. In both cases, the snow cover lasted until the end of March.

Jekyll and Hyde November 2009 Ends Up Warm, Dry    

    Meteorological fall (September through November) is now in the books, even though each month felt like a season of its own. How do the 11th warmest September and third driest September, the 9th coldest, 10th snowiest, and third wettest October and the third warmest November average out? Warmer than normal, but not in the top 10.

    With a temperature of 47.8°F, St. Cloud was 4.0°F warmer than normal. This ranked as the 22nd warmest fall out of the 129 years on record. In our recent streak of mild falls, 2004 (9th warmest), 1998 (10th warmest), 2001 (11th warmest), 2005 (15th warmest), and 1994 (16th warmest) all ranked warmer.

   The combination of the third driest September, the third wettest October, and a very dry November produced a fall precipitation of 6.98 inches, 6.01 of which fell in October. That total was 0.27 inch higher than normal. Despite a snowless November, fall 2009 did end up with 2.5 inches of snow, thanks to two of St. Cloud earliest snowfalls in October. The 2.5 inches now stands 7.2 inches below normal, but as noted earlier, this has been a common conditions over the past 6 years.