September 2015 Mid-South Climate Summary

...SEPTEMBER 2015 MID-SOUTH CLIMATE SUMMARY...

September, the first month of meteorological fall and containing the official calendar beginning to fall, was generally near normal in regards to temperatures, with all sites but Memphis averaging a less than one degree departure above normal. Conditions were drier than normal for the month, by as much as 3.03 inches at Tupelo, and by at least 0.50 inches at all sites.

Memphis was 2.3 degrees warmer than normal during September with its average temperature of 77.5 degrees, which was warm enough for the 26^th warmest September on record for the city. This becomes significant when we recall that Memphis has a 140 year temperature record, the longest of any of the official sites. Overall for the year to date, with only three full months left to go, Memphis is only 0.4 degrees cooler than normal. Tupelo was the second warmest site on record at 74.7 degrees, nearly 3.0 degrees cooler than Memphis, and 0.6 degrees warmer than normal for the month. For the year to date Tupelo is only 0.6 degrees cooler than normal. Jonesboro had an average temperature of 72.3 degrees, 0.4 degrees warmer than normal, while currently the site with the greatest departure from normal for the year to date at 1.8 degrees cooler. Finally, Jackson was the coolest of the four official sites during September with an average temperature of 72.1 degrees, a 0.7 degree departure above normal. Currently Jackson sits 0.6 degrees below normal for the year to date.

Climatologically August and September are the driest months of the year around the region, and we ended up even drier than climatology during September, with all sites finishing the month drier than normal. Tupelo had the greatest deviation from normal, only receiving 0.41 inches of rain, a 3.03 inch departure below normal. This made for the 6^th driest month of September on record for Tupelo. Despite this, Tupelo is still 13.07 inches of precipitation above normal for the year to date. Memphis was 1.77 inches of rain below normal, only receiving 1.32 inches during the month, and is currently 3.18 inches of precipitation below normal for the year to date. Jackson received 2.07 inches of rain this month, a 1.31 inch departure below normal, while currently sitting 5.72 inches drier than normal for the year. Jonesboro had the smallest departure from normal during September, finishing the month with 2.51 inches of precipitation, only 0.55 inches below normal. However, the site is still 5.72 inches of precipitation drier than normal for 2015. Below are the climate data for September:

TEMPERATURE DATA:

                               Memphis    Jackson   Jonesboro   Tupelo

Average Temperature (MONTH)  :   77.5       72.1      72.3      74.7

Normal Avg. Temp (MONTH)     :   75.2       71.4      71.9      74.1

Departure from Normal (MONTH):    2.3        0.7        0.4       0.6

Average Temperature (YEAR)   :   65.7       62.3      61.4      64.8

Normal Avg. Temp (YEAR)      :   66.1       62.9      63.2      65.4

Departure from Normal (YEAR) :   -0.4       -0.6      -1.8      -0.6

Maximum Temperature          :   97.0       94.0      93.0      95.0

Minimum Temperature          :   53.0       46.0      47.0      49.0  

PRECIPITATION DATA:

                                Memphis   Jackson   Jonesboro   Tupelo

Total Precipitation (MONTH)  :   1.32       2.07      2.51      0.41

Normal Precipitation (MONTH) :   3.09       3.38      3.06      3.44

Departure from Normal (MONTH):  -1.77     -1.31      -0.55     -3.03

Total Precipitation (YEAR)   :  35.29     33.53      42.60     52.98

Normal Precipitation (YEAR)  :  38.47     39.25      34.17     39.91

Departure from Normal (YEAR) :  -3.18     -5.72      8.43     13.07

Percent of Normal            :    92%        85%      125%      133%

Climate Outlook:

We turn to the Climate Prediction Center (CPC) to get their best guess on the expected outcomes for the next three months. For the one month outlook for the month of October, the CPC has predicted equal chances of above, near, or below normal values for both temperature and precipitation. This means that no clear climate signal exists to determine an outcome with confidence. A strong El Nino is forecast this winter, and such an event will play a role in our local climate, with its effects most pronounced during the cool season. The current three month outlook for temperatures, which covers the months of October, November, and December collectively, is for equal chances of above, near, or below normal values. The precipitation forecast for the same period of time has enhanced odds of above normal precipitation values. More information will soon be forthcoming from our office concerning the possible outcomes from the expected strong El Nino event.

MAYE