Where is Summer?

Some great opportunities for weather photos the last several days as the unstable atmosphere has led to excellent cloud formations - mainly towering cumulonimbus - around the area on several occasions. We've added some photos to the media gallery, with video coming soon of Friday's thunderstorms.

The unstable atmosphere is directly tied to a pool of very cold air in the upper levels of the atmosphere that has been stuck over the Northeast for quite some time now. Within this pocket of cold air, surface heating from the still strong August sun has combined with lobes of energy rotating through the Great Lakes / Northeast, to produce building clouds and afternoon showers and storms. Even yesterday, despite temperatures in the mid to upper 70s and dew points only in the upper 50s to lower 60s, popcorn storms fired thanks to the unusually chilly upper level temperatures.

Today we will watch as the upper level storm center continues to spin moisture and energy through the region. As a result, we can expect numerous showers and thunderstorms to rotate across the area throughout the day. Pockets of torrential rain will be possible and some thunderstorms could contain frequent lightning, and thanks to the cold air aloft, even some small hail. As for timing, we should see one round of wet weather during the morning, with a second shot possible later Monday and into Monday night. If we're lucky, perhaps some sunshine in between.

While the worst of the weather is expected today, the upper level storm center will only slowly drift eastward and loosen its grip on our weather over the next few days. Consequently, while Tuesday and Wednesday should feature more sunshine than Monday, the sunshine will once again be "self-destructive" in nature. That is, the daytime heating will produce bubbling clouds and perhaps a passing afternoon or evening shower or thunderstorm around parts of the area.

Thursday's weather is a bit more of a question mark, which is saying something given how difficult the short and long range weather forecasting has been of late. A few days ago, it was looking like things might finally dry out and quiet down. While that may still happen, there's a potential stumbling block in there. A wave of low pressure will form near the Carolinas and strengthen as it heads northeastward and out into the western Atlantic. It's eventual evolution (i.e. strength and track) will hinge on the placement and amplification of the jet stream. A more pronounced jet, per the European model, would capture the storm and intensify it substantially for this time of year, providing us with an August coastal storm - with a windswept soaking rain. The NAM model is close to the Euro, but the rest of the global models suggest a flatter, more climatological flow, that wouldn't allow for such an unusual event. Given the time of year, a nor'easter seems unlikely. But it has been an unusual pattern of late! This afternoon's model runs should help clear this up some.

Looking further down the road, it finally appears as though the weather pattern is going to try and shift back to a more traditional summer time look, with the jet flattening out. This should allow high pressure to build over the western Atlantic, in a Bermuda-high-like fashion. As such, early next week it could turn warmer and more humid.

Keep an eye to the tropics as things should turn busy over the next 10 to 15 days.