“Sometimes I wonder what I’m gonna do but there ain’t no cure for the summertime blues.” – Eddie Cochran
That’s right. Summer is now upon us, which means it’s time for another seasonal outlook. Now I promise this will NOT be as lengthy a read as my Winter Outlook. We don’t have near the number of factors or complexities that must be examined when making a winter forecast for our area. That being said, no two summers are exactly alike. Take the past two, for instance. 2012 and 2013 were as different as night and day.
First, I should clarify the months I am focusing on here. Memorial Day weekend marks the “unofficial” start of the season, while June 21st is the first official day of Summer, according to the calendar. My forecast will focus on the period that makes up “Meteorological Summer”, which is June 1 through August 31st.
For sake of perspective, here are the AVERAGE temps/rainfall amounts for the next three months:
June: Temp: 75, Rainfall: 4.2″
July: Temp: 78.7, Rainfall: 4.1″
August: Temp: 77.5, Rainfall: 3.3″
Now, let’s examine some factors at play:
1. El Nino: Although it’s impact on our summers is typically not as great as it is on our winters, El Nino will play a role in how this one pans out. “El Nino” refers to warmer than normal sea surface temperatures over the Central Pacific Ocean waters close to the equator.
When this pattern shows itself during the summer, more times than not we will see a large ridge of high pressure build over the Western/Central U.S. with a bit of a trough over the East. Pictured below is the way I see the predominant jet stream pattern shaping up over the course of the summer. Keep in mind there will be fluctuations in the pattern from time to time.
2. Southwest/Southern Plains Drought: Perhaps you’ve heard about the recent California wildfires in the news. Many parts of the SW United States and Southern Plains are bone dry…much drier than normal. Drought begets drought, and as we saw here in South-Central KY two years ago, massive heat waves tend to build right over drought-stricken areas. The lack of evaporation (a cooling process) from dry ground/vegetation often allows daytime readings to soar and become incredibly hot. The Southwest U.S. is already getting a taste of that, and while I do NOT expect a repeat of 2012 here, we may feel that heat on occasion when the flow turns more southwesterly this season.
3. Great Lakes Chilled: Let’s not forget, we just emerged from one of the coldest winters much of the country experienced in the past couple of decades! A bi-product of that was the freezing of the Great Lakes, something that is NOT an ordinary occurrence. Lake Superior still more than half-blanketed in ice when this month began! The slow melting of that ice cover will keep the Lakes cool well into at least the early part of Summer. You may wonder, “what does that mean for us since we’re hundreds of miles south of the Lakes?” Well, the wind blowing off those cooler Lakes will translate to cooler surrounding land, and at times, that air may be transported southward when troughs develop in the jet over the eastern U.S. This may lessen our chances for seeing extended heat waves this season.
So, with those factors stated, here’s my outlook. As always, this is just my own take on how I see Summer 2014 playing out and NOT an official First Alert Forecast.
Temperatures: I do NOT look for a repeat of the kind of excessive heat we saw in 2012, when an all-time record high for June was established at sizzling 110 degrees! I think with an upper wind flow often coming from the WNW, we’ll likely see temps wind up just a hair below average when it all shakes out. That’s not to say we won’t experience a few very hot and humid days, and for us, that is NOTHING atypical. Humidity may run high on occasion, since I think we could experience a bit more rain than usual. Of course, the humidity combined with the heat makes readings “feel” hotter, but wetter soils tend to keep actual temperatures in check. But I think days that trip the National Weather Service’s “heat advisory” criteria (heat indices of at least 105) will be few and far between.
AVERAGE NUMBER OF 90 DEGREE DAYS FOR BOWLING GREEN IN A YEAR: 42* (*based on 1981-2010 average)
Number of 90 degree days last Summer: 22
*FORECAST NUMBER OF 90 DEGREE DAYS THIS SUMMER: Between 30-40 (below average)
*HOTTEST TEMPERATURE: 98 (in July)
*FORECAST NUMBER OF 100 DEGREE DAYS THIS SUMMER: I’m going to say none, although there may be a couple of close calls. I believe several days could feature heat index values between 105-110.
Rainfall: A WNW flow aloft often keeps the pattern pretty active for Kentucky during the summer season. It often results in disturbances that move along the flow, sometimes bringing us large storm clusters known as “MCS’S” (mesoscale convective systems). These often dump a good amount of rain, although they can sometimes result in damaging winds, something that may keep us forecasters on our toes. Things tend to become more dry as summer wears on, and I believe this one probably follows suit climatologically speaking. I don’t think this season is as soggy as last Summer, one in which July 4th was washed out for many, but I don’t foresee our area returning to drought in the near future.
AVERAGE RAINFALL FROM JUNE THROUGH AUGUST: 11.33″
Total Rainfall from June 1-August 31, 2013: 18.17″
*FORECAST RAINFALL FOR THIS SUMMER: Between 11-13″ (Near to just above normal)
One more footnote to the precip amounts: Remnants of a tropical system can skew the forecast totals quite a bit. That possibility cannot be ruled out.
So there you have it. I look for a fairly active pattern this summer, one that will be stormy at times though not as soggy as 2013. And while there will be a few scorchers, this season will not rub shoulders with those from the Dust Bowl era of the 1930s or the record-shattering Summer of 2012.
Have a great Summer!