Caribbean wave slowly organizing but no development soon

A Caribbean tropical wave has slowly organized overnight.  However, though conditions are somewhat favorable for development, I believe any development chance over the next 24 hours are very slim.

The wave is not moving much at the moment.  In addition, ship reports are coming in indicating very weak winds.  So, either the system is not generating much at the surface, or it is a very compact system; the latter of which I would tend to agree with.

It seems most likely at this time the areas most in trouble from this over the next five days are Nicaragua and Honduras.  This is a very mountainous region that would tear a low-to-mid-level system apart – which the Caribbean wave is.  So, I will not be discussing any potential impacts in western Cuba, Yucatan, or the United States Gulf Coast.  You’ll have to keep coming back later.

Recon will be flying into the system later today.

Now, onto the Quick Hits.

Quick Hits:

1. there have been two ship reports in the last six hours (as of 10:30 AM UTC) from the region:
   1. one approximately 73miles (135km) west-northwest of the center of circulation reported 1013mb (29.90in) pressure, falling 1mb (0.03in) in the past hour, with winds from the northwest (320°) at 9kts (10mph or 17kph); air temperature was 26°C (79°F); water temperature was 28°C (83°F);
   2. a second located about 130miles (241km) due east reported winds 15kts (17mph or 28kph) from the south-southeast; pressure was steady at 1012mb (29.88in); air temp was 27°C (81°F);
2. UW-CIMSS shear maps (04/0900Z, Nov. 4, 3:00AM CST) indicate mininum shear up to 5kts (6mph or 9kph) in the southern portion of the cyclone; however, 10kts (12mph or 19kph) westerlies are in the northern quadrant of the cyclone; 20kts (23mph or 37kph) westerlies are running about two degrees in latitude north of the cyclone;
3. UW-CIMSS 850mb vorticity (04/0900Z), 700mb and 500mb shows the low-level circulation centered approximately 11N, 82W; there are very faint indications of vorticity in the 200mb level to the southeast; this is a strong indication of a vertically-stacked system;
4. upper-level divergence continues to be favorable over the tropical low; lower-level convergence has improved over the past 24 hours;
5. as mentioned yesterday, SSTs are warm as much as 31°C (88°F) in some places but typically around 29°C (84°F); OHC values are as high as 70 kJ cm-2 in the region – not enough to support rapid development; the 26°C (79°F) isotherm extends to a depth of up to 100m (328ft) – pretty shallow;
6. a 04/1045Z (4:45 AM CST) GOES-IR image shows very cold cloud tops as low as -80°C (-112°F) building over and to the north of the center of circulation;
7. there continue to be good banding features containing convection near the system, according to a 04/0736Z (1:36 AM CST) Aqua-I 89H capture; however, a composite image at the same time indicates little deep moisture levels currently in the western quadrant (the eastern quadrant was not captured on this pass); accordingly, rainfall rate estimates are rather minimal, up to 0.5in (12.7mm) per hour;
8. a 04/1045Z (4:45 AM CST) water vapor image shows little moisture around the storm system;

Computer Model Forecasts

• the EMCWF (04/0000Z) run indicates a weak low should remain in the same general vicinity throughout the next five days;
• the CMC (04/0000Z) run doesn’t develop the system for another 72 hours taking it north-northwest across the northeastern tip of Nicaragua/Honduras and then to the north of the Yucatan Peninsula in five days;
• the GFS (04/0600Z) seems to no longer develop the system;
• the GFDL (04/0000Z) develops the system to a hurricane within four days while keeping it mainly in the same region before finally pulling it north and then to the west around Nicragua/Honduras;
• the HWRF (04/0000Z) is much more modest, developing the system to a moderate tropical storm before taking it inland and dissipating over northeast Nicaragua/Honduras;
• other track models generally follow inline with the HWRF and CMC keeping it stationary over the next few days before a general track north-northwest;
• intensity guidance suggests very slow development except the GFDI  which is out of it’s freaking mind with the GFDL bringing the system to a hurricane in five days;

Bottom line is I don’t expect development today.  At the same time, I wouldn’t be surprised.  Though the system is a little better organized, it is lacking deep convection which will not intensify the system.

Furthermore, with low air temperatures in the region (sub-80F), moderate SST’s but low OHC, there will be no chance of rapid development.

The GFDL and GFDI runs I think should be discounted.  I just don’t see this system becoming a hurricane in five days when it’s likely to remain in the same location for at least the next two days.

Interests in Honduras and Nicaragua, however, should be prepared – not necessarily for a landfalling cyclone, but for torrential rains.  As with what we saw in the Philippines and Vietnam, mountainous regions cause updrafts which increases rainfall rates.  It won’t take much in this instance.