A Look Ahead into OctoberLast Edited:
Well it's a new month! I know many of you (myself included) absolutely LOVE fall - right? Honestly, I love forecasting snow and seeing storms form in the Winter but Fall IS my favorite season hands down because of the potential for COMFORTABLE weather. I love sweaters and changing leaves and pumpkins. I DON'T love pumpkin spice EVERYTHING though. I mean when does it become TOO much? I was grocery shopping last night and I saw pumpkin spice nacho chips. Are you kidding me? I digress...
Most of you are obviously wondering what Mother Nature has in store for us this season, so I'll give you my thoughts on how it plays out. Some will be happy, others maybe not so much. In South Jersey it seems like we never get to enjoy the seasons. We go from one extreme to the next with very little in terms of enjoyable weather - or at least nothing prolonged and sustainable. At the end of August, I promised we'd actually SEE a Fall this year. I certainly stand by that statement as I see no reason to change my ideas. The first half of October may be a bit warmer than we'd like though as high pressure remains the dominating force behind the pattern. What do I mean by that? Take a look at the picture above. See that big "H"? That's a STRONG upper level high meaning warm air will be allowed to continue to pump into our region. The ridge is actually going to be amplified by Rosa coming into the Southwest and perhaps another storm behind it soon. Winds will generally be out of the southwest which also pumps in more moisture - more 'humid' days. Now, we're not talking oppressive, but not as nice as we'd want it to be. This is the OVERALL pattern, of course there will be cooler and drier days here and there with fronts coming through etc.
One of the reasons it's been warmer than average lately is because there's so much water vapor in the air. There's no way to argue that. There's more water vapor in the air globally, period. I believe THAT is why temperatures around the world are warming. More water means the ability to hold more energy which translates to a higher max temp potential. When you put the water vapor in the air it doesn't cool off as easily at night. That is skewing our average temps by A LOT actually. You can have slightly above average day time highs but when you're 8-10 degrees above average at night of course that changes the numbers up a bit. Eventually when our air mass is replaced by a cooler drier one, we will see those overnight lows come down as dry air cools MUCH easier.
Here's what I think happens by mid-month. Fingers crossed because this will be the real test for my long range forecast into the Winter season. I think that Southeast ridge begins to break apart and we will see the WELL BELOW NORM air that's currently trapped in Canada seep down into our neck of the woods. Notice how this graphic depicts the complete opposite as the one above? High pressure would set up in the Northwest pumping the ridge way up towards Alaska. What goes up, much come down which means a dip in the jet, or trough, would set up in the east making things cooler and more active overall. This is the kind of pattern you want in the WINTER for cold and snowy weather.
Why am I so confident that the flip will occur? In looking at the current Sea Surface Temperatures (SST) one can clearly pick out a couple key factors...
1. The heart of the Pacific is beginning to warm up. There will likely be an El Nino that forms in the coming month or two. It won't be a strong one and it won't be like the last one we saw as the bulk of the warm water is in a different position. Central based El Ninos are called Madoki. Generally they deliver cooler weather with more precipitation.
2. The cold water west of Australia. That's a GOOD sign as higher than normal pressures usually form as a result and the thunderstorm activity would be squashed and pushed east which has everything to do with the Madden Julian Oscillation (MJO) going into colder phases.
3. The warm water in the Central Pacific favors troughs which downstream translates to ridges in the west and troughs in the east.
I know it may be hard to wrap your head around all of this, if you're NOT a weather weenie, but trust me, it makes sense. Forecasting mid to long range is VERY complicated and if one factor doesn't line up as thought then the whole forecast could be blown. I'm a fan of putting numbers to my thoughts and seeing if they verify. Here's what I'm thinking for October:
Temperatures: + 1 Overall, turning cooler second half
Precipitation: + 2"
We will see how these numbers work out obviously by the end of the month. In the meantime we track the weather as it changes. Stay tuned!