National Weather Service United States Department of Commerce

Heavy Rainfall and Flash Flood Threats From the Lower Mississippi Valley Into Ohio/Tennessee Valleys; Elevated to Critical Fire Concerns Out West

Heavy to excessive rainfall with flash flood concerns will be possible from the Lower Mississippi Valley into parts of the Ohio/Tennessee Valleys. Elevated to Critical Fire weather threats will persist across the Great Basin and central Rockies. Finally, Major to Record river flooding will continue in portions of the Midwest and across parts of North and South Carolina. Read More >

 May 2011 continued the string of months with below normal temperatures and above normal precipitation.  The average temperatures for May were from 2 to nearly 5.5 degrees below normal across the region.  The train of strong upper level low pressure systems kept rolling over the region bringing 3 to over 4 inches of rainfall for May.  The average highs were well below normal ranging from 4 to 8 degrees below normal.  With the cooler temperatures, severe weather was also kept at a minimum for the month. Flooding also continued throughout the month mainly along the James River and on Lake Poinsett.

 

 MAY 2011

       

Temperature Data

Aberdeen

Sisseton

Wheaton

Watertown

Warmest Temperature / Date

83 / 10th

87 / 30th

87 / 31st

85 / 30th

Coldest Temperature / Date

27 / 3rd

27 / 1st

27 / 1st

25 / 3rd

Average High / Departure from Normal

65.2 / -5.1

64.3 / -5.9

64.1 / -8.2

63.8 / -4.1

Average Low / Departure from Normal

44.2 / -1.4

43.6 / -2.5

44.3 / -2.8

43.6 / 0.0

Monthly Average / Departure from Normal

54.7 / -3.2

53.9 / -4.3

54.2 / -5.5

53.7 / -2.1

Precipitation Data

       

Monthly Precipitation / Departure from Normal

2.93 / +0.24

3.40 / +0.64

3.36 / +0.82

4.13 / +1.52

Most Precipitation in 24 hours / Date

0.88 / 11-12th

0.81 / 20-21st

0.88 / 28th

1.19 / 30th

         

Temperature Data

Pierre

Kennebec

Mobridge

Timber Lake

Warmest Temperature / Date

88 / 8th

86 / 8th

85 / 9th

82 / 9th 

Coldest Temperature / Date

27 / 2nd,  3rd

21 / 3rd

20 / 2nd

22 / 2nd

Average High / Departure from Normal

64.9 / -6.5

67.4 / -6.6

64.5 / -5.1

63.7 / -5.9

Average Low / Departure from Normal

43.7 / -2.6

43.2 / -2.9

42.2 / -3.4

41.4 / -3.1

Monthly Average / Departure from Normal

54.3 / -4.6

55.3 / -4.8

53.4 / -4.2

52.5 / -4.6

Precipitation Data

       

Monthly Precipitation / Departure from Normal

3.24 / +0.10

3.77 / +0.75

2.50 / -0.13

3.27 / +0.37

Most Precipitation in 24 hours / Date

1.09 / 11-12th

1.10 / 21st

1.10 / 20th

0.89 / 20th