vortex95

Problem we are seeing with Macro is similar to Laura, just not quite as bad. Note how recently convection waned over the center, re-fired in a small blob, and now is waning again. That's a sign of dry air entertainment. Also, the larger more intense convective blob just to its NE -- surrounding large blobs like this discrete from the center are not good b/c that area will collapse and send out outflow at low levels into the LLCC. Also, it interferes with the anticyclonic smooth outflow aloft that tries to get established over the central convection.

If Macro is a hurricane now, it is still not that impressive on satellite. Minimal banding and transient convective blow-ups. It is also elongated N-S. 12z SHIPS output shows significant shear by 18 hr with RH dropping below 60%. As mentioned in previous posts, it is likely going to get torn apart as it moves further N esp. due to its small size. http://hurricanes.ral.ucar.edu/realtime/plots/northatlantic/2020/al142020/stext/20082212AL1420_ships.txt

NHC noted in the 18z update that conditions in 3-5 day period will not be favorable and have lowered the development chances to 30%. A large part of the tropical Atlantic is devoid of deep convection, as the SAL/dry air dominates. Look at how far S the ITCZ is displaced. As I mentioned in another thread, something does not seem right here. Everything is supposed to favorable for Cabo Verde TCs, but we are still dealing with significant large-scale issues and we are in climo peak period now. Should this be happening in a hyperactive season? Time will tell.

Really bizarre looking now. Yesterday it was a large cluster of convection. Now an exposed LLCC and a large band of convection well-removed to the NE. This is what you'd expect a TS or min hurricane to look like after it moved over the Yucatan, not before (hollowed out center)! Also, peripheral convection seems to be driven more by the deep trough to the NW.

It's not always the best practice to rate an AEW for TC potential later while it's still overland because its convection is mostly diabatically driven. This is what we see with the wave on the west African coast now. Also, looking at the WV and 250 mb analysis, there is TUTT not far to the W. So we can see why the global models don't do much with this wave. One other thing, due to parallax of GOES-16, deep convection in this part of its view will look more intense than it really is.

K0A0 - Truth or Consequences/Spaceport NM (alias code) http://www.airnav.com/airport/9NM9 K1S3 - Forsyth MT KCYD - Mississippi Canyon 807 LA 28.169 / -89.223 46m KE41 - Big Lake TX KJSY - Joseph OR KK82 - Smith Center KS KMJD - Picayune MS KNRN - Norton KS KSMD - Fort Wayne/Smith IN KVGC - Hamilton NY KVHN - Van Horn TX Site ID Change: K40J to KFPY (Foley FL)

Indeed! And it shows things are kind of messed up in the ern tropical Atlantic. Where is the deep easterly uniform flow that is almost always present this time of year that brings all African waves steadily westward? If this anomalous flow sticks around for awhile, it is going to put a dampener on some sig Cape Verde TC potential.

Exactly. Couldn't have said it any better. Everything has to be practically perfect for a TC of at least min hurricane intensity to make landfall on LI or the New England coast. One thing is off (i.e. not moving fast enough, trof to W not sharp enough, first landfall down the coast, etc) it greatly reduces the overall threat and impact, at least from a wind and surge point. Rainfall can still be high impact, but you don't need a hurricane for that anywhere. It also helps if the hurricane is intense off the SEUS coast to begin with. It's been 29 years since the last hurricane made landfall on LI or the New England coast, by far the longest period on record going back to 1851. This shows how hard it can be during certain cycles/patterns. Of course, between 1938 and 1960, we got 5 hurricanes, all stronger at landfall than any of the 4 hurricanes the area has had since 1960. Feast or famine it seems!

Still skeptical on the more W track. The trough that evolves over the ern U.S. is not digging and is positively tilted. That's not how you typically bring a TC to SNE. Basically it is just riding a channel in the mean flow, not drawn in by backing flow. One thing I have noticed empirically over time, is that these things tend to recurve out sharper than any model forecast in a synoptic set up like this. You have to find a good reason why it will *not* recurve out sharper than forecast. Here's the pattern that brought Bob up. It was focused, digging s/w trof that gave SNE decent +RA/+TSRA only 24 hr after Bob departed. And the next image is the 00z GFS for 96 hr. It's not the same. In Bob's case, you had a dumbbelling effect.

CoastalWx won't be happy until hell freezes over!