TALKWEATHER 2010/11 POWESHIEK COUNTY, IOWA WINTER FORECAST

ISSUED 7 SEPT 2010 - TALKWEATHER 2010/11 POWESHIEK COUNTY, IOWA WINTER FORECAST:

NOVEMBER 2010 - TOTAL SNOWFALL 1 INCH (ON OR AROUND 10 NOV) - AVERAGE TEMP 55F (2 DEG F ABOVE NORMAL - FORECAST HIGH TEMP OF 70F BEFORE MID-MONTH - FORECAST LOW TEMP 25F BY THE 21ST...

DECEMBER 2010 - SHOULD SEE A WHITE CHRISTMAS - TOTAL SNOWFALL 6 INCHES WITH WHICH MOST WILL FALL IN THE LAST TWO WEEKS - HIGH TEMP IN THE MID/HIGH 60'S WILL OCCUR IN THE FIRST WEEK - LOW TEMP OF -5F WILL OCCUR IN THE LAST WEEK - AVERAGE TEMP FOR THE MONTH WILL BE NEAR 30F - 5 DEGREES BELOW NORMAL...

JANUARY 2011 - MOST OF A TOTAL SNOWFALL OF 12 INCHES WILL FALL IN THE FIRST TWO WEEKS OF THE MONTH - WE'LL SEE A MONTHLY HIGH TEMP OF AROUND 48F BY THE LAST WEEK - AND A LOW OF -1F WILL OCCUR DURING THE FIRST WEEK - AVERAGE TEMP FOR THE MONTH WILL 22F, WHICH IS A NORMAL TO SLIGHTLY BELOW AVERAGE TEMP FOR JANUARY...

FEBRUARY 2011 - MOST OF 8 INCHES OF SNOW WILL FALL THRU WEEKS TWO AND THREE - DON'T RULE OUT A MAJOR ICE STORM LATE IN THE MONTH - HIGH TEMP IN THE LOW 60'S WILL OCCUR BY MID-MONTH - LOW TEMPS IN THE TEENS AROUND WEEK THREE - AVERAGE TEMP FOR THE MONTH WILL BE 35F - ALMOST 6 DEGREES ABOVE NORMAL..

MARCH 2011 - 10+ INCHES WILL FALL FOR THE MONTH - MOST OF WHICH WILL FALL IN THE FIRST TWO WEEKS FROM A STORM AROUND THE 10TH OF THE MONTH (MAY SEE SOME ICE AS WELL) - A HIGH TEMP OF 73F WILL OCCUR NEAR THE END OF THE MONTH - LOW TEMP IN THE SINGLE DIGITS WILL OCCUR IN WEEK ONE - AVERAGE TEMP FOR THE MONTH WILL BE NEAR 37F - 2 DEGREES BELOW NORMAL...

WINTER TOTALS:
TOTAL SNOWFALL - 37 INCHES - NEARLY 5 INCHES ABOVE NORMAL...
AVERAGE TEMPERATURE - NOVEMBER 2010 THRU MARCH 2011 - +/- 1.50 OF AVERAGE...

APRIL 2011 - AVERAGE RAINFALL FOR APRIL IS 3.25 INCHES - EXPECT A WETTER THAN NORMAL APRIL - NEAR 6 INCHES WILL FALL, 2.75 ABOVE NORMAL...WE'LL PROBABLY SEE THE HIGHEST TEMPS OF THE MONTH (75F DURING THE FIRST WEEK), AND LOWEST TEMP OF THE MONTH AROUND THE 15TH (30F)...WE'LL HAVE AN AVERAGE TEMP OF NEAR 52 - NEARLY TWO DEGREES ABOVE AVERAGE...

Climate of Iowa

Topographic Features- The State of Iowa comprises 56,288 square miles, primarily of rolling prairie, located in the middle latitudes between the Mississippi and Missouri rivers. The interior continental location is approximately 850 miles north of the Gulf of Mexico, 1450 miles east and northeast from the Pacific Ocean, 1050 miles west and northwest from the Atlantic Ocean and 1050 miles south-southwest of Hudson Bay. The extreme north-south distance across Iowa is 215 miles; the extreme east-west distance, 330 miles. Elevation changes are small across the State, varying from a maximum of 1670 feet in Osceola County in northwestern Iowa to 480 feet at the southeast tip of the State at the confluence of the Des Moines and Mississippi rivers. There is some rugged terrain in the northeast. Most of the State’s natural lakes are located in the
northwest.

Iowa’s climate, because of its latitude and interior continental location, is characterized by marked seasonal variations. During the six warmer months of the year, the prevailing moist southerly flow from the Gulf of Mexico produces a summer rainfall maximum. The prevailing northwesterly flow of dry Canadian air in the winter causes this season to be cold and relatively
dry. At intervals throughout the year, air masses from the Pacific Ocean move across the western United States and reach Iowa producing comparatively mild and dry weather. The autumnal ‘Indian Summers’ are a result of the dominance of these modified Pacific air masses. Hot, dry winds, originating in the Desert Southwest, occasionally reach into Iowa during the
summer producing unusually high temperatures and crop desiccation.

Temperature- The average annual temperature ranges from 45 degrees Fahrenheit (° F) in the extreme north to 52 in the southeastern corner of the State. In July, the hottest month, daily temperatures range from morning lows of around 61 and afternoon highs of 82° F in the northeast corner of the State up to lows of 65 and highs of 87 in the southwest. In January, the coldest month, temperatures range from morning lows of 4 and afternoon highs of 22° F in the northwest corner of Iowa up to lows of 15 and highs of 32 in the southeast. Extreme temperatures have varied from 118° F at Keokuk on July 20, 1934 to -47° F at Washta on January 12, 1912 and again at Elkader on February 3, 1996. In almost every year, at some location in the State, a maximum exceeds 100° F and a minimum of less than -20 occurs. In half of all years, the State maximum exceeds 104 and the minimum -30. The average number of days with maximum temperatures 90° F or higher ranges from only eight days in extreme northeast Iowa up to 36 days in the southwest corner of the State. The number of days with
minimum temperatures 0° F or lower ranges from about 28 days along the Minnesota border to around 12 days along the Missouri border.

Seasonal snowfall averages 32 inches across Iowa and varies from around 40 inches in northeast Iowa to about 20 inches in the extreme southeast corner of the State. The snow season normally extends from late October through mid-April but significant snows have fallen as early as September 16 (1881) to as late as May 28 (1947). The average number of days per season with snow cover one inch or deeper varies from about 40 days along the Missouri border to around 85 days along the Minnesota border. In about half of all winters, a daily snowfall of five to six inches or more is recorded in southern Iowa and seven to eight inches or more in northern Iowa. December, January and February are normally the snowiest months, averaging about seven inches each. However, late winter and early spring storms in March and April have produced as much as 27 inches of snow in a single storm and 24-hour amounts have reached 24 inches. The snowiest winter of record (since 1887 - 1888) was 1961 - 1962 with a statewide average of 59.0 inches while the lowest State average, only 11.9 inches, occurred in the winter of 1965 - 1966. Seasonal snowfall totals have varied from 2.4 inches at Keokuk in 1965 - 1966 to 93.1 inches at Elkader in 1950 - 1951.