MN Transplant

This is the meme template of the year, IMO.

Dumping

If you haven't in the past, make sure to hit Swallow Falls State Park. That is a gem.

Three-day precip, to give a little context to the pre-game action too.

I did better yesterday, I think. I'm under 2" since midnight.

Looks like I'm going to end up in the 2.4-2.5" range with a peak gust in the 20s. Not unexpected, but kind of a dud the further west you get. Heck of a show in MD/DE, though!

You won't have to wait long.

From the west side of the Beltway - no.

Down to 70 at DCA. Lowest since June 26th.

Gust to 51 mph at Richmond.

5z HRRR is on crack. Has better winds at DCA than they got in Wilmington.

Um

Eastern eyewall is cranking

There is a 111 mph inbound pixel on the Wilmington velocity scan. Obviously well off the surface, but not bad.

Straight from the horse's mouth (Lance Bosart of Albany via the MAP mailing list) "As Isaias accelerates north-northeastward after landfall in the Carolinas the northern part of its rain shield will attempt to merge with the southern end of a separate rain area near the central Appalachians. This separate rain area, which has some elements of a predecessor rain event, is associated with weak warm-air advection in the equatorward entrance region of a strengthening jet streak. The absence of an antecedent cool high over eastern Canada has limited the magnitude of the lower tropospheric thermal gradient across the Northeast and the potential for significant warm-air advection well in advance of TS Isaias."

NAM Nest is robust. And as we all know, it is the best tropical model out there.

Probably easiest to step through here: https://weather.us/model-charts/standard/maryland/gusts-1h-3h-mph/20200804-1300z.html

Probably more realistic on gusts. ~40-45 mph in the 95 corridor.

12z HRRR was a disappointment for 95 and west. 12z NAM Nest still looks quite good, with gusts in the 50s and 4-6" of rain.

Here’s Ocean City from the Euro. The times are local.

The Windy app has this handy “wind accumulation” map. Effectively, it is the highest wind gust at any one point from the models. The Euro is presented for weenie purposes only since we know that the wind products are problematic. Low 50s at DCA, low 60s Balt inner harbor, low 70s Annapolis, low 80s Salisbury. The GFS shaves 15-30 mph off that. The NAM Nest has a flatter distribution in the 50s, which is still impressive.

Very rare. That was a special event.

That March synoptic wind event from a couple of years ago!

HRRR puts down 1.5”-3” for many of us before the core of the storm gets here.

Still looking ragged on radar on the S and SW sides, but the towers on the IR and the canopy on the water vapor loop certainly show a storm that is holding its own.