MY 2024 ATLANTIC HURRICANE SEASON BIRDSEYE VIEW POST #100

*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.*********

...UPDATE...THURSDAY OCTOBER 17 2024 11:16 AM EDT...

The surface and upper air charts valid for October 15 have been added below.

...TUESDAY OCTOBER 15 2024 11:59 PM EDT...

For the Atlantic basin... continue to monitor the following areas of interest for possible tropical development in the days ahead:

(1) A central Atlantic tropical wave of low pressure which continues to have development potential while moving toward then into the northern Caribbean Islands over the next five days... see area of interest #40 section below for details.

(2) A broad area of low pressure in the central Caribbean which may gradually develop within the next couple of days and before it drifts west into a landfall with Central America... see area of interest #42 section below for details.

(3) Due to the force of a forecast eastern US deep-layer ridge... the southwestern tail of the current eastern North America upper trough is forecast to become cut-off in the mid-latitudes of the western Atlantic when the upper trough later moves offshore. The combination of upper divergence ahead of the cut-off upper vorticity... the cold de-stabilizing temperatures of the upper vorticity... and the ongoing warm sea surface temperatures in the mid-latitudes of the western Atlantic may allow for the formation of a surface low pressure area with thunderstorms and possible tropical characteristics over or in the vicinity of Bermuda within the days ahead. As such may need to add a new area of interest for the mid-latitudes of the western Atlantic in future updates.

AREA OF INTEREST #40... Satellite image of eastern/central Atlantic tropical wave of low pressure on 0520Z Monday October 14 when is swirl center (pointed to with yellow arrow) featured a small central area of thunderstorms:

The surface tropical wave of low pressure that has recently moved into the central Atlantic from the eastern Atlantic developed a small area of central thunderstorms over its cloud swirl center on Monday. Then throughout much of today the swirl became obscured by two areas of expanding thunderstorm activity... however more recent satellite imagery tonight shows the eastern area of thunderstorms has collapsed while the western area has become better-organized around the swirl center. The forecast track of this system has been nudged southward due to the more south initial position... a testament to the strength of the current steering north-central Atlantic surface ridge. As such this system is now expected to continue west around 16N or 17N latitude through 24 hours... potentially bending more north toward 18N latitude by 72 hours when reaching the southwest edge of the surface ridge. The track then continues west into the northern Caribbean Islands through day 5 as the strong eastern North America surface ridge that builds behind the current Atlantic Canada frontal cyclone slides offshore into the western Atlantic. Regarding development potential... the tropical wave remains under favorable low shear/outflow beneath the mid-ocean upper anticyclone/ridge... continues to track west into lower concentrations of dry Saharan air... and has become better organized tonight... therefore I have raised peak odds of tropical cyclone formation to above 50% despite not all of the global models agreeing on developing this feature. I trim odds of development to 0% towards day 5 due to increasing land interaction with the northern Caribbean Islands... and as northerly wind shear increases due to the approach of what will be the southwest cut-off tail of the current eastern North America upper trough. Interests across the northern Lesser Antilles... Virgin Islands... Puerto Rico... and the Dominican Republic should be monitoring the progress of this tropical wave as tropical cyclone impacts (heavy rain... gusty winds... and coastal surf) are possible late this week and into the weekend.

******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********

Formation chance through 3 days… 70% (just northeast of the northern Lesser Antilles near 18N-61W)

Formation chance days 3 to 4... 60% (Puerto Rico near 18N-66W)

Formation chance days 4 to 5... 0% (south coast of the Dominican Republic near 18N-71W)

*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT*************************

Formation chance through 48 hours... 30%

Formation chance through 7 days... 50%

AREA OF INTEREST #42... A sprawling area of low surface pressures continues in the central Caribbean Sea. In the upper-levels suppressing upper vorticity that was overtop this system has dissipated... and as of Monday and today this disturbance continued to produce hours-long thunderstorm flare ups with the aid of the outflow associated with the southwest extent of the ongoing mid-ocean upper anticyclone (surface convergence provided by a passing surface tropical wave that came in from the east today may have also aided in the most recent activity). During and in between the flare ups the broad central Caribbean surface low has become increasingly defined by outer curved thunderstorm bands. Upper-level winds are expected to remain conducive for tropical development as the next wave of suppressing upper vorticity to the east never makes it overtop this disturbance while also collapsing from isolation from high-latitude cold air. Noting by 24+ hours a deep-layer ridge is likely to build over the eastern US after the current Atlantic Canada frontal cyclone departs... therefore forecasting possible tropical cyclone formation offshore of Central America through day 2 after which time the deep-layer ridge will have most likely pushed this system into Central America by day 3. As such interests in Central America should be remain aware of the possible Caribbean tropical development within the remainder of this week. Although the GFS model has stopped aggressively developing this system... I have not lowered odds of tropical cyclone formation below 30% as this system has also become better defined with outer curved thunderstorm bands as noted above.

******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********

Formation chance through 2 days... 30% (over or near coastal Nicaragua)

Formation chance days 2 to 3... 0% (over inland Nicaragua)

*****National Hurricane Center (hurricanes.gov) official outlook as of 8 PM EDT*************************

Formation chance through 48 hours... 10%

Formation chance through 7 days... 20%

...COMPUTER MODEL SUMMARY...

Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/).

0000Z (Oct 15) CMC Model Run...

**For area of interest #40... tropical cyclone formation suggested just north of the northern Lesser Antilles at 84 hours... reaches hurricane strength while reaching the southeasternmost Bahamas through 126 hours... drifts west-southwest into the waters between the southeastern Bahamas and eastern Cuba through 168 hours

**For area of interest #42... no development shown

0000Z (Oct 15) ECMWF Model Run...

**For area of interest #40... no development shown

**For area of interest #42... no development shown

0600Z (Oct 15) GFS Model Run...

**For area of interest #40... no development shown

**For area of interest #42... no development shown

0600Z (Oct 15) NAVGEM Model Run...

**Not available at above-mentioned source