hawkeye_wx

There are clearly some negative forces affecting TD10. Convection blew up this morning and tried to align the various levels together, but satellite and Cancun radar suggest an area of sinking air is pressing down from the north, which is eroding the convection and pushing it south of the weak surface circulation. All of the deep moisture is south and well east of the center. The global models must have seen this. Edit: The surface center has performed a bit of a loop overnight and this morning. It passed southward over Cozumel, then continued southward for a while, but then turned east, passing under this morning's convection, and has now moved well out from under the convection and may be moving northeastward.

TD10's overall appearance was better 24 hours ago. It is trying to get its act together southeast of Cozumel this morning. The question is can it maintain the convection today and organize the core or will it fizzle during d-min like yesterday? The first recon plane is headed in from the east, but it is still several hours away.

The new recon dropsonde says 970 mb.

Yep. Warm and bone dry for the foreseeable future. The early August rain was just a brief tease.

Some of the models were right about the vorticity dropping southward and not doing too much, for now. Cancun radar shows a bit of a misalignment. The convection and mid level rotation appears a bit east of the surface center. The surface center moved ssw for a while, but now appears to be getting pulled back east a bit toward the new convection.

This system really lost its core convection this afternoon.

Oddly, the GFS drops the 500 mb vorticity southward, but keeps the weak surface low stationary, off the northeast tip of the Yucatan.

All the hurricane models (hwrf, hmon, hafs) have greatly ramped up the strength as it shoots northward toward landfall.

Does anyone have any thoughts about why models continue to refuse to strengthen this system at all through Monday, even though they all now show it remaining over the Caribbean and under upper ridging?

This looks like a tropical depression. The convection was increasing overnight, but this morning it has clearly developed into a spiraling pattern, with a center just east of the northeast tip of the Yucatan. The visible loop also clearly shows a north/northwest flow over the northeast Yucatan.

The latest center dropsonde recorded 986 mb.

The shear has become more favorable, but the core will have to mix the dry air out and build better convection over the next day or two.

Even though this is looking healthier this morning, models are still slow to organize it over the next couple days as it spins over the nw Caribbean. Then, on Monday, when it ejects northward, models are showing a digging upper trough over the gulf stretching out 93L's energy, which prevents it from doing too much until it gets into the northeast gulf.

I was going to mention this. Models had it moving northeastward this morning, but instead it's moving southeastward.

The Euro is trending toward sticking this energy over the Yucatan for 2-3 days, limiting its potential.

Surprisingly, Cedar Rapids did not hit 100º today.

The new Euro is similar to the last few... the system spins around in the far nw Caribbean for a couple days, but doesn't organize much. It only revs up once it's shooting northeast in the eastern gulf.

Cedar Rapids has stalled at 95º over the last hour. Combined with a lower dew point, the heat index is 12º less than at this time yesterday.

Cedar Rapids is 2º ahead of yesterday (we hit 100º) and the dew point is several degrees lower than yesterday, so I'd say 100º should be easy to hit today.

The Euro continues to meander some 500 mb vorticity just off the Yucatan coast over the weekend. Even though it also shows an upper ridge centered over that area, it struggles to develop anything until the energy lifts into the gulf.

I wasn't sure Cedar Rapids would be able to hit 100º, but we did it. I am a bit disappointed the dew maxed at 79º.

Models largely had this thing nailed a few days ago when they showed it finally organizing and tightening at the very last second before landfall. If Harold looked like this 24 hours ago, we'd be talking about a much more significant system.

It was never able to align. The convection continues to be elongated and displaced north of the surface center. The overnight recon struggled to even close off a low center.

We'll have to wait and see what recon finds for wind direction in the other quadrants, but it seems likely we'll have TS Franklin at 5pm.

The morning visible loop shows that 90L has developed a closed circulation. There is some shear, so convection is trying to hold onto the east side of the center.