That Was A Close Call

MON 5/11: Talk about dodging a bullet. What is happening now over the Mid-Atlantic is quite amazing for the month of May. A nor'easter is raging over the Delmarva, producing wind gusts to 60mph as its central pressure lowers to 986mb. Heavy rains are pounding the Jersey shore, where winds along the coast are frequently gusting to 50mph. Seas have built to 15 to 20 feet as well. That's quite a storm for anytime of the year. Thankfully, for us, we are on the far northern fringe of the system and should remain that way throughout its life cycle.

This storm is interesting in that while it was well-modeled in terms of its overall development, it has ended up much further south than expected and much stronger than computer guidance predicted. Even as of today's / last night's computer runs, the storm was running some 5 to 10 mb deeper than model initializations. This, of course, leads to much stronger winds and will certainly cause some coastal flood problems over the Mid-Atlantic - where coastal flooding warnings, storm warnings and wind advisories are posted.

This all could have been ours! However, here on the Cape, the more southern route is combining with dry air from high pressure to our north to impede the northward progress of precipitation and the strongest winds. Instead of a soaking rain (as expected several days ago) we will be left with cloudy skies and gusty northeast winds on Monday. Later today and tonight, some of the moisture spinning north and westward around the storm could rotate onto the Cape and give us some drizzle, mist and showers, but overall, no heavy rain is expected this far north. All-in-all, when we look back at the two nor'easters than developed out of this weather pattern, we will have only totaled around 1 inch of rain as both systems ended up quite a bit further south than expected - certainly far less rainfall than I had forecast last week. So it goes sometimes in the world of weather.

The wind, while not as strong as it could have been, will still be an issue as a tight pressure gradient is developing between the powerful storm center to our south and high pressure well to our north. Wind Advisories are up for the islands, but have not been posted for the Cape - at least not yet. Regardless, northeast winds will increase through the day, and should gust to 35 mph during the afternoon and over 40 mph tonight - especially along the Outer Cape where it will be a nasty day when the wind, clouds and cold temperatures are combined. Winds of this strength and duration will cause beach erosion at high tide, mainly from P-town down to Chatham.

This whole system slowly spins eastward on Tuesday, gradually pulling away from the Eastern Seaboard. While it won't really be moving any quicker than it looked last week, its overall position further south and east will allow for better weather to move in more rapidly than earlier expectations. This should lead to developing sun on Tuesday, but still very cool and rather windy conditions (the strongest wind out of this event comes late Monday night / Tuesday morning when sustained winds should approach 25 to 30 mph with frequent gusts to 40). Speaking of cool temperatures, readings on Monday will hold in the 40s with wind chill readings in the 30s at times - weather more like early April than Mid May. It's so cold over the Northeast, in fact, that snow has been reported at some of the higher elevations in the Mid-Atlantic. Highs on Tuesday should be a bit better, but still chilly, in the 50 to 53 range.

Sunshine and milder temperatures will take hold on Wednesday as we finally get rid of the gusty, cold north to northeast wind. While winds will still come in from the north, they won't be as active and add in the strong May sunshine and readings should return to 60F or so.