This past week has featured the most summer-like weather we've seen since April. And yet, the heat wave of late April still boasts the highest temperatures for the year in many locations. The shift west in Atlantic ridging developed a strong southerly flow over the eastern US which in addition to warmer temperatures, also transported copious moisture northward. What was already a wet month in the northeast has reached record levels after multiple rounds of tropical rains swept through the area.
Looking ahead over the next 10 days, here are some of the highlights:
(An updated official forecast will be posted tomorrow)Frontal system moves eastward with strong upper level dynamic and moisture, producing more heavy showers and thunderstorms Friday.
Saturday through Sunday morning, the atmosphere stabilizes with sunny skies across interior New England. Highs will reach the mid 80's both days.
The next system approaches on Sunday with another round of showers and thunderstorms Sunday night into Monday.
The weather dries on Tuesday followed by a frontal boundary bringing showers Tuesday night and then drying again Wednesday with another round of showers Thursday afternoon. The general trend of temperatures will be downward through the period. Generally, looking at highs in the upper 70's to near 80 next week.
Ridging will be developing in the center of the nation next week, and will expand eastward for the weekend. The highest heat will be suppressed southward with weak disturbances riding through the northern US, however we could see a day or two with highs 5 to 10 degrees above normal.
This brings up the next point: Normal temperatures have turned the corner and are on the decline. Looking at the big picture, winter is coming up quick.
First autumn comes, and with that, increased hurricane activity. It is July 30th now, and the Atlantic has yet to see its first named storm. Activity in the Atlantic basin continues to be very quiet and no development is expected in the short term. I'll post a more detailed long term discussion and hurricane statistics in the tropical weather outlook later in the week.
The situation in the Pacific continues to be somewhat uncertain for the upcoming boreal winter. June featured a significant warming east of the dateline with weekly Nino3 anomalies reaching +1C by June 24 and Nino3.4 at +0.9. Since then, SST anomalies have held steady. However, trade winds have strengthened through July and have notably dampened anomalies. The warmest waters are currently between 160E and 180 with totals around 29.5C. The strongest anomalies remain between 120W and 130W, just west of the influence of the Chilean current. But increasing easterlies will likely begin to chip away at these anomalies over the next few weeks. Further west, a strong westerly wind burst has developed near 150E. This argues for increasing totals propogating eastward in the next couple weeks and rising anomalies in the west Nino regions. In general, through the end of August expect the development of a west-based El Nino. Whether the configuration lasts through the autumn and into the winter is the big question.
As I've mentioned in a few discussions on here over the last few months, signs for the upcoming winter (including the developments in the Pacific and a rapid tumble in the QBO) are pointing toward overall below normal temperatures and above normal snowfall in the northeastern US. More details will be added on through the autumn and of course in my winter seasonal outlook coming later in September/October.
|posted by Sam Lillo @ 7/30/2009 09:44:00 AM
