MikeS 66 Index JULY 2013

The official statistics are not out yet for the month of July. However, my index of 66 random locations comprising the various climate regions of the contiguous United States revealed some interesting data.

It was a month dominated by persistent weather patterns. A large ridge in the west. A cutoff low in the Gulf of Mexico. A large upper level low spinning across the Hudson Bay. A bulging southeast ridge. Sometimes, it was a matter of the have's and have not's, especially when it came to precipitation.

Overall, the temperatures averaged out right at normal. However, the overall precipitation came in well above normal. Four of the six climate regions produced above normal readings with the southeastern U.S. coming in with some of the wettest July's in years. This was due to a persistent onshore flow of moisture resulting from a stationary non-tropical low spinning just south of the Florida panhandle.

Now for the numbers...

High Plains 73.4 average of high and low
                                    0.4 Below Normal (temps)
                                    14% Below Normal Precipitation

Midwest  72.3
                              0.3 Below Normal
                              25.8% Above Normal Precipitation

Northeast  75.8
                                 2.2 Above Normal
                                 25.8% Above Normal Precipitation

Southeast  80.0
                      1.2 Below Normal
                                 64.3% Above Normal Precipitation

Southern   80.9
                      1.2 Below Normal
                                 3% Above Normal Precipitation

West         77.1
                     1.7 Above Normal
                               13.7% Below Normal Precipitation

You can tell how the western ridge affected temperatures and precipitation there. Extreme heat prevailed over much of the desert areas. Also, the persistent upper low in the Gulf produced enormous amounts of rain. What I found staggering about those numbers was that normal rainfall amounts start ramping up during tropical weather season. In fact, places like Tampa FL and Wilmington NC generally see at least 7" on average for the month of July. Although Tampa exceeded their average, Wilmington's 5.64" for the month was a stunning 1.84" below normal! There were no tropical systems in July that directly affected the U.S. but many locations added to their June totals making inroads on one of the wettest summers on record.

As for the Northeast, I was there when temperatures soared well into the 90's and touched 100 in a few areas. The dew point was high adding to the discomfort. Power outages occurred. Children often flocked to fire hydrants to keep cool. Some of the places I visited were running on generators just to cut down on the high energy demands.

Here's the final tally for the United States as a whole:

United States (48 contiguous) 76.6
                                  0.0 Average
                                        14.2% Above Average Precipitation

MS