*******Note that forecast 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.**********
...TUESDAY OCTOBER 11 2022 3:04 AM EDT...
Julia has dissipated as a tropical cyclone while making landfall over southwestern Guatemala... however the outer northern circulation of Julia's remnants is being monitored for signs of development in the Bay of Campeche. See Remnants of Julia and area of interest #39 section below for more information. Elsewhere... continuing to watch for the potential formation of an open central Atlantic subtropical or tropical disturbance this week. See area of interest #38 section below for more information.
New to this site this year... I will be sequentially numbering up areas of interest for possible Atlantic tropical development. In this scheme... will reset back to #1 at the start of next year (January 2023). The current areas of interest in this blog post are designated #38 and #39 as the other numbers were used in previous birdseye view posts. This scheme is to reduce confusion as Atlantic tropical activity increases during the peak of the hurricane season... when multiple simultaneous areas of interest begin and end which previously required shuffling around the area of interest numbers from update to update.
REMNANTS OF JULIA... The circulation center of what was minimal Tropical Storm Julia made landfall over southwestern Guatemala on Monday afternoon where it proceeded to dissipate. The remaining and rather large outer circulation of the storm has become elongated southwest-to-northeast while stretching from the eastern Pacific to the Bay of Campeche... Yucatan peninsula of Mexico... and western Caribbean. This remaining circulation is expected to split into two disturbances... one to the southwest in the eastern Pacific to track westward and parallel to the south Pacific coast of Mexico... and another to the northeast which will be monitored for signs of tropical development in the Bay of Campeche while becoming entangled with a cold front to be driven across the Gulf of Mexico by a sprawling frontal cyclone that is beginning to develop over North America. Because this site is dedicated to Atlantic tropical activity... the eastern Pacific disturbance will not be covered on this blog... refer to the NHC eastern Pacific tropical weather outlook at hurricanes.gov (hurricanes dot gov) for more information on the eastern Pacific system. See area of interest #39 section below for more information on the Bay of Campeche disturbance.
AREA OF INTEREST #38... The broad surface trough of low pressure in the open central Atlantic is continuing west-northwest into a surface ridge weakness between an Atlantic surface ridge to the northeast and additional surface ridge over the eastern United States to the northwest... and was located in the vicinity of 27N-52W as of 0000Z earlier this evening. The surface trough was initially generated by the eastern divergence zone of the upper vortex in the region... and now appears to be supported by split flow upper divergence between northerlies streaming into the northwest side of the vortex and southwesterlies ahead of a large upper trough approaching from eastern Canada. This large upper trough is expected settle in the western Atlantic as an amplified feature during the five-day forecast period. At 3+ days... the surface trough has potential to mature into a subtropical or tropical disturbance that turns east-northeast with the motion of the upper trough... while becoming supported by the eastern divergence zone of the upper trough. Because the upper trough will be amplified... wind shear levels could very well be low enough to support an organizing tropical or subtropical disturbance. However I assign low 10% odds of tropical cyclone formation during this timeframe due to the lack of computer model support showing development and as the eastern divergence zone of the upper trough will tend to be elongated instead of focused with a maximum... which could instead result in too broad of a system that struggles to consolidate into a surface cyclone feature.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Oct 12)...0% chance of tropical cyclone formation (central Atlantic near 27.5N-54W)
IOH 48 Hr Outlook (0000Z Oct 13)...0% chance of tropical cyclone formation (central Atlantic near 27.5N-55W)
IOH 72 Hr Outlook (0000Z Oct 14)...10% chance of tropical cyclone formation (central Atlantic near 28.5N-53W)
IOH 96 Hr Outlook (0000Z Oct 15)...10% chance of tropical cyclone formation (central Atlantic near 29.5N-50.5W)
IOH 120 Hr Outlook (0000Z Oct 16)...10% chance of tropical cyclone formation (central Atlantic near 30.5N-44.5W)
AREA OF INTEREST #39...On Monday afternoon... the northern outer circulation of what was left of Tropical Storm Julia resembled a broad scale surface trough of low pressure across the western Caribbean Sea... Yucatan peninsula... and Bay of Campeche. From 1200Z to 1800Z on Monday satellite imagery suggested the maximum spin of the trough was near the Belize/Quintana Roo border on the east coast of the Yucatan peninsula. As of late the maximum spin now appears to be further west at a thunderstorm burst over the southwestern Campeche province (near 18N-91W)... with a general area of curved thunderstorm bands stretching from the western Yucatan province... across the northern and western Bay of Campeche... and into southeastern Veracruz supporting this idea. This disturbance has already been introduced into the NHC tropical weather outlook with tropical cyclone odds as of late already being set to 40% in response to increasing computer model support showing development. This marks the thirty-ninth Atlantic tropical area of interest I have tracked on this blog this year.
Models agree that this disturbance will meander in a clockwise loop turn in the Bay of Campeche over the next few days in weak steering currents. Initially the disturbance will curve north toward the surface ridge weakness associated with the sprawling North American frontal cyclone that is currently developing. Once the frontal cyclone pushes a cold front across the Gulf of Mexico... the front will reverse the track of this disturbance on a southeastward drift between 48 and 72 hours. The loop is then completed after 72 hours as a surface ridge building behind the front pushes the disturbance westward. The eastern divergence zone of an upper vortex pivoting into the southwestern United States is likely to create a surface ridge weakness to the northwest by the end of the 5-day forecast period... and this disturbance's track may make an increasing northward bend in its track by 120 hours. The forecast track in the outlook below incorporates all of these ideas while initializing the disturbance at 18N-91W per the observations noted in the previous paragraph.
Regarding odds of tropical cyclone formation... I set peak odds of 30% and shorter-term odds below this value as the disturbance does not yet have a fully-closed surface circualtion and will need some time to develop one... and may have to combat some unfavorable factors while trying to establish a closed circulation. This is also why my peak odds are a notch below the NHC's odds as of this writing. Specifically over the next 72 hours... the upper trough to be associated with the sprawling North American frontal cyclone could push the tropical upper ridge in the region southward... exposing this system to possible northwesterly shearing winds on the southwest side of the upper trough. In addition cool dry air behind the cold front to push into the Gulf of Mexico may dampen the thermodynamic favorability for tropical development. By 96 and 120 hours as the frontal cyclone... upper trough... and cool dry air begin a slow northeastward retreat... this is when I set my peak 30% odds of development.
Interests across southwestern Campeche... Tabasco... Chiapas... Oaxaca... and Veracruz should be aware that this meandering disturbance over the next few days has potential to produce episodes of heavy rainfall with flash flooding and mudslide potential. Coastal areas of southwestern Campeche... Tabasco... and Veracruz may see gusty winds should tropical cyclone formation occur and need to monitor the progress of this disturbance carefully.
******Infohurricanes.com outlook. Visit hurricanes.gov (hurricanes dot gov) for official outlook***********
IOH 24 Hr Outlook (0000Z Oct 12)...10% chance of tropical cyclone formation (south-central Bay of Campeche and just offshore of the Tabasco/Veracruz border near 19N-93.5W)
IOH 48 Hr Outlook (0000Z Oct 13)...20% chance of tropical cyclone formation (Bay of Campeche near 20.5N-95.5W)
IOH 72 Hr Outlook (0000Z Oct 14)...20% chance of tropical cyclone formation (Bay of Campeche near 19.5N-94.5W)
IOH 96 Hr Outlook (0000Z Oct 15)...30% chance of tropical cyclone formation (Bay of Campeche near 19.8N-95.5W)
IOH 120 Hr Outlook (0000Z Oct 16)...30% chance of tropical cyclone formation (just offshore of the north coast of Veracruz near 21N-97.5W)
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Oct 10) CMC Model Run...
**For area of interest #38... no development shown
**For area of interest #39... surface low becomes better defined just offshore of northern Veracruz at 48 hours... sprawling frontal cyclone over North America pushes cold front across the Gulf of Mexico which drags the surface low southward into southeastern Veracruz coast at 108 hours where it dissipates.
**Tropical wave currently over western Africa emerges from the west coast of Africa at 42 hours... through 120 hours organizes into a tropical low near 10.5N-30.5W
1200Z (Oct 10) ECMWF Model Run...
**For area of interest #38... no development shown
**For area of interest #39... surface low becomes better defined on the south-central Bay of Campeche coast at 24 hours... moves northwest to the waters just offshore of northern Veracruz at 48 hours... sprawling frontal cyclone over North America pushes cold front across the Gulf of Mexico which drags the surface low southward into southeastern Veracruz coast at 120 hours where it dissipates.
1800Z (Oct 10) GFS Model Run...
**For area of interest #38... no development shown
**For area of interest #39... surface low becomes better defined in the Bay of Campeche near 19.5N-95W at 36 hours... surface low drifts northwest to 21N-95.2W through 69 hours... sprawling frontal cyclone over North America pushes cold front across the Gulf of Mexico which drags the surface low southward to 20N-95W at 84 hours... under influence of a surface ridge building behind the front the surface low drifts southwest into the central Veracruz coast through 120 hours where it dissipates.
**Tropical wave currently over western Africa emerges from the west coast of Africa at 39 hours... north side of tropical wave fractures off as a northwestward-moving surface trough at 138 hours located near 15N-37.5W... surface trough evolves into a surface low near 24N-37.5W at 168 hours
1800Z (Oct 10) NAVGEM Model Run...
**For area of interest #38... no development shown
**For area of interest #39... surface low becomes better defined in the Bay of Campeche near 20.5N-95.5W at 36 hours... drifts north and becomes a tropical cyclone near 22.5N-95.5W at 66 hours... sprawling frontal cyclone over North America pushes cold front across the Gulf of Mexico which drags the tropical cyclone southward to 21N-95W through 96 hours... under influence of a surface ridge building behind the front the tropical cyclone drifts west-northwest toward the northern Veracruz coast through 120 hours
**Organized tropical wave with low pressure spin reaches the west coast of Africa at 168 hours.
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