The week ahead: Unsettled and cool, keeping an eye on later next week

Despite the “unstable” outlook for the first part of the week, we don’t need to write off any of the upcoming weekend. Unfortunately, the threat of another nor’easter looms for later in the week. And I even slipped in a sneak peek at the forecast for next weekend’s Anthem Richmond Marathon.

November 2, 2012; 3:15 PM • by Weather Dan

I’m keeping this update a bit short as I try to unwind from all the Sandy coverage – and there has been plenty to go around.

In terms of coverage, Boston.com’s Big Picture blog has always been a favorite of mine – they do an incredible job of letting the pictures of an event tell its story, and their coverage of Sandy’s impacts is no different. Check it out.

Don’t forget to set your clocks back one hour this weekend, as it’s the end of daylight saving time. Also remember to check the batteries in your smoke detector and NOAA weather radio.

As far as the week ahead goes, the short-term is looking…unstable, for lack of a better word. We’re going to see a couple quick periods where we change from clouds and rain back to sun and then back again, but there’s nothing major going on in the atmosphere; it’s more a series of small troughs that will keep things a little unstable. It’s noisy, but not overtly so, if that makes any sense.

Let’s start with a look at the model-generated temperatures for the coming week:

The good news is that the weekend starts off absolutely fabulous, if not a bit blustery. High pressure will keep the cloud coverage limited on Saturday, so even though we may see some wind gusts back into the 20 mph range, it should easily be the best day of the weekend. Clouds begin to creep back on Sunday, as a weak surface low slides across the southern US and a weak cold front drops in from the northwest. While this won’t be a big rainmaker – and in fact may not give us anything at all in terms of measurable precipitation (not good, when we’re running a rainfall deficit of 3.79” since January 1). That said, don’t be taken by surprise if we see something show up in this time frame.

The bigger story starts to come together around midweek, as the models have been predicting the development of another large coastal low pressure system off the Carolinas on Wednesday with a high level of confidence. Our exact impacts will, as you can imagine, be very dependent on the track. The European model (which zeroed in on Sandy’s final track several days prior to landfall) keeps the system closer to the coast. That would create an extended period of rainfall for us, especially east of I-95. A couple of the model runs have thrown in some evidence of the dreaded s-word for parts of central Virginia, but I’m heavily inclined to discount that. If this were December 2 instead of November 2, I might be singing another tune. (That said, if it does materialize, know I’ll be right back here letting you know what to expect.)

It’s hard to say right now how much rain we might get from this system, but that picture should become much clearer over the weekend and by Monday. Even though there’s some dark clouds looming on the horizon, we’ve got a great start to the weekend. I hope you’re all able to enjoy it.

And runners? Here’s a sneak peek at next Saturday morning – the long range models are hinting at possibly a bit of a wedge setup behind the nor’easter next weekend. My thinking right now is for mostly cloudy or overcast skies (maybe with a hint or two of drizzle during the race), and a temperature near 40 when the first gun goes off.

November 2, 2012 3:15 PM 1