We have struggled to reach normal temperatures this week, with plenty of rain and Wednesday as the only sunny break. We end this week with more cool, damp weather, before transitioning to warmer, drier conditions this weekend. Portions of the area received anywhere between 2-4″ of rain between Sunday night and Tuesday night, which will help improve drought conditions, however, these rainfall totals also led to flash flooding across large portions of the area.

Rest of today – cloudy, with a small chance for isolated light showers, cool with temperatures topping out only in the low-mid 60s, about 10ºF below normal for this time of year.

Friday – more clouds and cool weather, with this easterly onshore flow regime sticking around for one more day. High temperatures will again be only in the mid-60s, much below normal. There is a slightly higher chance Friday for scattered showers, but nothing like the soaking we got earlier this week.

Saturday – some improvement in conditions will take place Saturday as high pressure starts building from the west. Partly sunny skies may give way to more sun, with high temperatures warmer near 80.

Sunday – high pressure moves to our east, allowing us to enjoy another pleasant, dry day, with high temperatures in the mid-70s.

Monday – a frontal system approaches the area. Ahead of the front, warmer air will flow in from the southwest, giving us temperatures at or above normal near 80ºF. As the front nears, thunderstorms and showers are possible across the region.

Arctic Jet Stream Slowing Leading to Increased Incidence and Duration of Extreme Weather? 

The massive quantities of snow that fell over the Northeast this past winter, the flooding rains over Texas last month, the enduring drought over California, and the asphalt-melting heatwave in India have all raised the question of what is causing this apparently increased incidence of long-duration extreme weather events. One possible explanation offered by researchers at Rutgers University is that the polar jet stream circling the Arctic has been slowing.

Jet streams are generated by two factors: the rotational energy of the Earth spinning on its axis, and the pressure gradient between two airmasses of varying temperatures. In the case of the polar jet circling the Arctic, rapid warming of the Arctic over the last couple decades has led to a decreased thermal and pressure gradient between air over the Arctic and air directly to the south. Researchers posit that this effect has led to a slowing of the polar jet stream. Since the jet stream is responsible for moving large (synoptic) scale weather patterns, any affect on its speed and orientation can have dramatic impacts for widespread regions of the world. In this case, the slowing polar jet stream is theorized as the mechanism behind the prolonged effects of the weather events mentioned above.