andyhb

Bottom continues to fall out on the sub-surface readings. This is a pretty stout cooling occurring.

That doesn't really say a whole lot about whether there will be storms and of what mode.

That is a violent tornado.

Holy mother.

That's going to be a strong tornado in the northern burbs.

I don't like the looks of that supercell near the Chester/Delaware County line.

Have seen some damage pictures out of the area that look at least EF2.

There's the Edgewater tornado, probably significant given TDS height and peak VROT of 45 kts.

70/30 probs on that new watch for E MD/PA/NJ. Pretty stout probabilities for this region.

The cell south of Charlottesville has quite a meso on it, but that central VA radar hole is being a giant pain.

Have seen some forecast hodographs from this and yeah, things are going to be spinning pretty easily. Outside shot of a sig tor or two given the environment.

The eye continues to warm and the pressure continues to fall. It’s not leveling out yet.

That phenomenon is called "Cat 4s and 5s are still quite rare".

Supercell near Marble Rock IA looks prime for a sig tor.

SHIPS Prob RI for 20kt/ 12hr RI threshold= 61% is 12.4 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 82% is 7.5 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 76% is 11.1 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 70% is 17.9 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 53% is 22.2 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 73% is 15.8 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 47% is 10.0 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 31% is 5.9 times climatological mean ( 5.3%) SHIPS RI probs are going berserk now, as expected.

Note the center's westward jog as it crosses Cuba.

987 mb on the new advisory.

Detailed surge risk map of New Orleans.

Looks like it will take a track along the length of the loop current rather that perpendicular to it.

Betsy is close to the worst case track, which would be coming from the SE/SSE putting the NW and eastern eyewall over the metro/lake. In such a case, water would be funneled from the Gulf into the lake and then piled into the levees by northerly flow on the lake. The Mississippi would also see a surge.

Here's a link to the folder for the SHIPS text files for those interested. https://ftp.nhc.noaa.gov/atcf/stext/ The ones you'll want to use for this storm are entitled/formatted: "YYMMDDHHAL9921_ships.txt", where YY is year, MM is month, DD is day, and HH is hour of issuance. Probs for 65 kt/72 hr RI for TD9 are already fairly high and I'd imagine they will rise.

Potential Julian sounds like Carla Cradle music to me.

...which is usually pretty good with intensity forecasts...

SHIPS RI probs starting to take off with Grace especially beyond 24 hours. SHIPS Prob RI for 20kt/ 12hr RI threshold= 10% is 2.1 times climatological mean ( 4.9%) SHIPS Prob RI for 25kt/ 24hr RI threshold= 33% is 3.0 times climatological mean (10.9%) SHIPS Prob RI for 30kt/ 24hr RI threshold= 22% is 3.2 times climatological mean ( 6.8%) SHIPS Prob RI for 35kt/ 24hr RI threshold= 11% is 2.9 times climatological mean ( 3.9%) SHIPS Prob RI for 40kt/ 24hr RI threshold= 8% is 3.3 times climatological mean ( 2.4%) SHIPS Prob RI for 45kt/ 36hr RI threshold= 21% is 4.5 times climatological mean ( 4.6%) SHIPS Prob RI for 55kt/ 48hr RI threshold= 27% is 5.8 times climatological mean ( 4.7%) SHIPS Prob RI for 65kt/ 72hr RI threshold= 33% is 6.2 times climatological mean ( 5.3%)