Sunday, May 17, 2015 1:48 PM

Firsthand Weather’s 2015 Summer Forecast

Matthew Holliday

I want to begin by explaining what a seasonal forecast is, and what I’m trying to accomplish by putting out this seasonal forecast for this upcoming summer. A seasonal forecast is NOT a day-to-day forecast but is meant to give you an overview of what to expect over a given timeframe. My goal is to give you an early heads up on what kind of weather could be on the way this summer, and I will be breaking down each weather event and/or pattern change as the summer progresses. Also, there will be fluctuations in temperatures/precipitation during this forecasting period, meaning you will not likely experience non-stop cooler/warmer weather for the entire 90-day period.

For this outlook, I broke it down into two periods, one being for June and the other being for July through August. Technically, the June map includes the second half of May also, even though I just labeled it June. All you need to do is look at the two maps, find your region (which is numbered), and then find your forecast discussion below. There will be two local forecast discussions for your region, along with the main discussion below.

Summer 2015 Discussion:

El Nino has continued to develop through this past winter and spring and is forecasted to strengthen through this fall. While the main focus has been on this developing El Nino over the last few weeks, I don’t believe that El Nino conditions will be as prevalent across the United States later this summer. However, after this summer, the typical El Nino conditions should begin to really take hold.

While I’m not saying that we won’t approach moderate to strong El Nino conditions by this fall, I think that the climate models are way overdone on how strong this El Nino becomes. Most likely, the waters will actually begin to cool off near the coast of Peru later this year and warm across the central Pacific. Keep in mind that the spring models wrongly predicted an El Nino event last year, and while I believe model guidance will be more right the second go-round, that doesn’t mean there won’t be fairly sizable errors.

As you will see in my outlook below, I do believe that many areas will experience a fairly hot summer, which goes against the majority of the forecasts that have been put out this year. Also, many of the areas that have been very wet will continue to be excessively wet through June, and then many of those same areas will dry out significantly in July and August. The majority of you will likely experience a variety of weather, which is why I broke it down into two periods instead of one.

June 2015 Forecast (includes the rest of May):

June 2015 Forecast

Region 1: This area will continue to experience the same kind of conditions that have pretty much dominated since this past winter. There could be several chances of rain/mountain snows especially in the areas away from the coast early on in the period. I put this area in reasonably dry conditions, although some areas may get lucky and get pretty close to average precipitation.

Region 2: I put this region in a warming up/drying out zone to express that the overall pattern will begin to change through this period. Anytime there is a transition period, you can almost always expect changing weather conditions. While conditions could initially remain cool/wetter at the beginning of this period, there will eventually be a shift to a drier/warmer pattern later in June. I’m not ruling out the possibility of parts of California getting some beneficial rains early in this period, but this will be far from a drought breaker. Drought conditions will likely strengthen and may temporarily get worse in some places as summer progresses.

Region 3: This region could be notably cooler during this period. Precipitation could end up being about average or maybe even above average in some places. Parts of the Rocky Mountains could see some late-season mountain snows and even parts of the Northern Plains could see some of the white stuff.

Region 4: This region is going to remain very wet and unsettled, especially in the southern regions. Since many areas across the Plains have already gotten excessive amounts of rainfall, flooding will continue to be an issue. As we head closer to the end of June, conditions could begin to improve. Overall, the pattern will be cooler, although humidity may make things seem a bit warmer, particularly in the South. The severe weather threat will continue, but this threat should shift east and north through this period.

Region 5: This region has been considerably drier over the last few weeks, but that will begin to change as we head into June. Along with an increase in precipitation, a heightened severe weather threat could develop. Conditions will be pretty warm/hot and humid through this period. Some of the northern areas in the zone could experience intermittent cooler conditions, but it shouldn’t be anything that lasts for a long period of time. Flooding could become an issue for many areas in this region later in June.

Region 6: The heat will continue to build over this region, and conditions should remain quite dry along the coast. Farther inland in the western parts of this region could receive some decent rainfall, but that is a bit questionable at this point. I’m still keeping an eye on Typhoon Dolphin in the western Pacific to see whether or not that will bring about a cooler pattern downstream over this area. Although this could bring cooler temperatures, I believe this would be temporary enough not to effect the overall forecast for this period.

Region 7: This entire region will probably become wet and quite hot/humid, especially west. Flooding could particularly become an issue over the Mississippi Valley region (which could become big news), and the severe weather threat will probably increase through this period especially farther west. Although cooler conditions will be possible at times, this should only be temporary. The humidity will be what makes things seem that much hotter!

July – August 2015 Forecast:

July - August 2015 Forecast

The regional discussions for this period are VERY brief.

Region 1: A cooler pattern should begin to emerge during this period. Precipitation should be about average, but given that places like California typically do not get a lot of rain during the summer, drought conditions will persist. Fall/winter will be different though. 🙂

Region 2: This region will become wetter throughout this period and should end up being slightly cooler than average.

Region 3: This region is really going to begin warming up, but precipitation should be about average or maybe even above average in places.

Region 4: This region should experience a temporary dry-out period during these two months, and conditions will be hot (above average temps)! This will be sandwiched between a very wet period that is ongoing right now, and a wetter period that will start back up this fall/winter. I didn’t take into account possible tropical activity along the coastal regions during this period, which I will discuss more later this month.

Region 5: Conditions will begin drying out during this period, and this region will experience the typical summer warmth. There may be some variability in the temperatures, but nothing that should be too noteworthy. Southern Gulf coast regions could get more precipitation than areas farther north.

Region 6: This is the region that I’m a little more uncertain about. I’m more confident that this area will remain dry, but the temperatures are where I’m a bit more uncertain. I went with cooler than average temperatures for reasons that I will discuss as we get closer to this period.

Region 7: This region should really dry out with the exception possibly being along southern Gulf coast regions. Temperatures may be slightly below average during this period, and the humidity shouldn’t be as bad as earlier in the summer.

Region 8: Much of Florida should be wet/humid. They may even end up a good bit wetter during this period than earlier in the summer.

Conclusion: Again, this outlook is meant to give you a look at the big picture. Don’t confuse this seasonal forecast with my medium and long-range forecasts that cover a few weeks at a time. Last winter, I realized just how much a seasonal forecast can be misinterpreted. December 2014 was warm overall, but January and especially February 2015 ended up being very cold in the eastern U.S., verifying the overall forecast. The weather is always changing!

If you combine my June and July/August forecasts together, you will quickly come to the conclusion that I am expecting a true summer for the majority of you. Yes, there could be cool periods in between as I tried to explain in the discussions, but overall this summer should be different than the summer many of us experienced last year. There will, of course, be exceptions to that.

Be sure to follow Firsthand Weather on a daily basis as I will be breaking down each individual weather event and pattern change throughout this summer. Also, follow Firsthand Weather on the different social media platforms, where I put out multiple updates a day.