News and Notes

The quality controlled Iowa COOP data for February 2016 has been uploaded to the IEM. These observations are kindly provided by Harry Hillaker, our state climatologist, who passes along these notes on the month:

General Summary. Iowa temperatures averaged 28.0° or 4.0° above normal while precipitation totaled 0.96 inches or 0.09 inches less than normal.   This ranks as the 33rd warmest and 69th driest February among 144 years of records.   Snowfall averaged 9.0 inches or 2.2 inches above normal to rank as the 37th snowiest February among 129 years of records.   This was the seventh consecutive snowier than normal February.

Temperatures. Bitter cold weather made a relatively brief appearance in Iowa during February with subzero temperatures reported on only the 4th, 5th and 10th through 13th.    Temperatures were above average every day from the 15th through the end of the month with only a handful of locations seeing readings dip below 20° during the second one-half of February.   Cresco reported the month’s lowest temperature with a -17° reading on the morning of the 13th.   Temperatures reached 73° at Shenandoah and Sidney on the 18th while Sidney reached 75° on the 27th.   These are the highest February temperatures recorded in Iowa since 1999 (76° at Glenwood on Feb. 10).   In response to the milder late-month weather soils began to thaw across central and southern Iowa on the 19th and were completely frost-free over about the southern one-half of Iowa at month’s end.   The late-month warmth also melted most of the snow cover that had persisted over northern Iowa since December 28.   Some flooding occurred in response to the snowmelt and ice jams that resulted from the break-up of river ice.

Heating Degree Days. Home heating requirements, as estimated by heating degree day totals, averaged 25% less than last February and 7% less than normal.   Season-to-date degree day totals are running 17% less than last season at this time and 13% less than normal.   The warmer weather and lower energy prices should result in considerably smaller heating bills this winter compared to recent years.

Precipitation. Over one-half of the month’s precipitation fell very early in the month with the major winter storm of the 2nd-3rd.   Heavy snow fell across the northwest one-half of Iowa with greatest amounts reported of 14.0 inches at Washta, 13.6 inches at Akron and 13.5 inches at Sheldon.   However, only a cold rain fell across extreme southeast Iowa with this storm.    There were very frequent light snow and/or rain events between the 3rd and 21st.   The largest of these events came on the 13th-14th when 2 to 4 inches of snow fell over much of the northeast one-half of the state.   However, winds gusts of 40 to 50 mph combined with light snowfall and deep snow cover left from the Groundhog Day storm system to create blizzard conditions over north central Iowa from the night of the 7th through the morning of the 9th.   Finally, winter weather made a return visit late on the 29th into March 1st with 2 to 5 inches of snow falling across the northern one-third of the state.   Overall monthly precipitation totals were well below normal over east central and southeast Iowa and well above normal over the northwest.   February precipitation totals varied from 0.20 inches at Williamsburg to 1.92 inches at Sheldon.  Monthly snowfall totals varied from only 1.3 inches at Clarinda to 23.4 inches at Sheldon.   Snow totals have been well above normal in three of the past four months in northwest Iowa.

Severe Weather. Wind gusts in the 50 to 60 mph range were common statewide on the 19th with Iowa City Airport reporting the highest gust at 63 mph.

Winter Summary. Temperatures over the three mid-winter months averaged 26.7° or 4.6° above normal while precipitation totaled 6.51 inches or nearly double the seasonal normal of 3.34 inches.   This ranks as the wettest and 17th warmest winter among 143 years of state records.   The last warmer winter came four years ago (2011-2012), averaging 1.2° warmer than this one.   Despite slightly below normal precipitation in January and February these two months brought enough precipitation when combined with December 2015’s record total to easily surpass the 6.00 inch total of the 1914-15 winter for the wettest on record.

The following is the number of new daily records set at COOP sites based on data back to 1951.

                 2016___________2015_____________________________
                 FEB  JAN  DEC  NOV  OCT  SEP  AUG  JUL  JUN  MAY
Maximum High:    213   29  244   85   75  130   25   22   69   28
Minimum High:     59   98   13   56   21   13  269  261   88  316
Maximum Low:     159   89  467  171   79  336   38   54   32   82
Minimum Low:      19   63    5   58   20   25  156  139   26   87
Maximum Precip:  141  156  439  316  162  150  158  214  151  155

The following is a table summarizing how well the IEM daily data estimator is working in comparison to the quality controlled data.

                 2016                  2015
                 FEB   JAN   DEC   NOV   OCT   SEP   AUG   JUL   JUN
High Temp Bias   0.6   0.3   0.2   0.3   0.2   0.0   0.1   0.0   0.0
High Temp STD    2.4   2.1   2.0   2.2   1.8   1.7   1.8   1.7   1.7
Low  Temp Bias   0.2   0.2   0.1   0.2   0.1   0.0   0.2   0.2   0.2
Low  Temp STD    2.4   2.5   2.2   2.7   2.6   2.1   2.1   2.0   2.0
Precip    Bias   0.01 -0.01 -0.01 -0.00 -0.01  0.01 -0.01  0.00  0.00
Precip    STD    0.07  0.27  0.14  0.14  0.08  0.26  0.27  0.29  0.33