Cold, Wet October

Published: November 3, 2009

October 2009 will go down as one of the Top 5 wettest and coldest Octobers on record for Missouri (Figure 1). Preliminary numbers at the end of the month indicate statewide temperatures averaged about 6 degrees below normal with nearly three times the normal rainfall. Some locations witnessed their wettest October in more than a century. St. Louis, MO recorded their wettest October on record, with 12.38 inches officially tallied at Lambert International Airport. That's an amazing statistic considering St. Louis has precipitation records that extend back 137 years.

Initial October rainfall reports indicate October 2009 will rank as Missouri's second wettest October on record. Officially, October 1941 ranks as the wettest October on record for the Show Me state, with an average statewide total of 10.47 inches. Preliminary numbers for 2009 are indicating a statewide average of just over 10 inches. Regionally, 4-7 inches were reported across northwestern sections, but these totals were offset by heavier amounts, in excess of a foot, across several east central and southeastern counties. A few locations in southeastern Missouri reported more than 15 inches of rain during October. It will be close in regard to breaking the 1941 record, but it's safe to say most Missourians have seen their wettest October.

Temperatures for the month were much below normal and preliminary numbers are indicating 2009 will rank between the 3rd and 5th coolest October on record, and the coolest October in more than 30 years. A very active weather pattern during the month led to frequent rain events and extended cloudy periods. These conditions, combined with cool temperatures, slowed evaporation and brought persistent wet soils across Missouri. Similar weather conditions were reported across much of the Midwest, as well as a growing concern for major harvest delays.

Fortunately, a significant weather pattern change occurred during the beginning of November with drier and milder conditions anticipated for the first half of the month. Temperature and precipitation scenarios are more uncertain for the latter half of November.

The latest winter outlook for Missouri, according to the Climate Prediction Center, calls for above normal temperatures for the northwestern half of the state and equal chances for above, below and near normal temperatures for the rest of Missouri. Below normal precipitation is anticipated across far southeastern sections with equal chances of above, below and near normal precipitation for the rest of the state.