*******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.**********
...SUNDAY OCTOBER 9 2022 2:50 AM EDT...
Julia is currently a mid-range category 1 hurricane making landfall in east-central Nicaragua. What remains of Julia is also expected to spread impacts across Honduras... El Salvador... Guatemala... Chiapas... and Oaxaca over the next four days. See Julia section below for additional information on the hurricane.
Elsewhere... the open central Atlantic upper vortex that sheared apart and dissipated tropical depression twelve a couple of days ago is now producing thunderstorm activity in the vicinity of 25N-45W with its eastern divergence zone. What will remain of the upper vortex is expected to merge with the current eastern North America upper trough and an additional upper trough to quickly follow behind from central Canada to make a large-scale western Atlantic upper trough. This large-scale upper trough is also forecast to be amplified enough to produce low wind shear and an area of increased upper divergence in the open central Atlantic... which could result in the formation of an open central Atlantic subtropical or tropical disturbance that may need to be monitored for signs of development later this upcoming week.
HURRICANE JULIA... The episode of brisk strengthening that Julia began 24 hours ago while located in the open south-central Caribbean Sea came to a halt by Saturday morning as aircraft reconnaissance data indicated Julia still had a broad instead of tight well-defined circulation center. The growth in the storm size over the last 24 hours also indicates a broad system. In addition the effects of light northerly shear... induced by the tropical upper ridge axis in the region being north of instead of directly over Julia... were more pronounced for much of the day on Saturday as the thunderstorm activity became weighted toward the south side of the circulation. However Julia still has managed to at least gradually intensify into a minimal category 1 hurricane with 75 mph maximum sustained winds as of 8 PM EDT Saturday when a central burst of thunderstorm activity located toward the south side of the storm center managed to become more symmetrically distributed over the center. This makes Julia the fifth hurricane of the 2022 Atlantic Hurricane Season (after Danielle... Earl... Fiona... and Ian). Some additional strengthening into a stronger category 1 hurricane is possible over the next few hours before the center of Julia makes landfall later this morning on the east-central coast of Nicaragua.
My updated forecast track below is once again nudged westward as Julia continues to move a little faster to the west relative to prior forecasts. At 48+ hours... an amplified western Canada upper trough is expected to support a sprawling frontal cyclone that will weaken the west side of the steering surface ridge located over the United States... resulting in Julia's westward track slowing down and bending more north such that it hugs the eastern Pacific coastline from El Salvador to southeastern Mexico. Although the models agree on Julia's center of circulation reaching the eastern Pacific near the Nicaragua/Honduras border region... curiously they also want to dissipate Julia's circulation while developing an adjacent eastern Pacific disturbance to the southwest... therefore the NHC official forecast dissipates Julia after its eastern Pacific entry. The formation of the adjacent eastern Pacific disturbance is probably a reflection of ongoing northeasterly vertical shear in the region as the tropical upper ridge axis is forecast to remain to the north... which will have a tendency to push Julia's thunderstorms to the southwest such that the thunderstorm latent heat release driven outflow may induce the adjacent low pressure disturbance while Julia's circulation itself may struggle with land interaction while parked near the eastern Pacific coastline per the latest track forecast. My current forecast strategy is to keep Julia a distinct feature through 72 hours... however lower the intensity forecast due to Julia currently being behind my previous intensity forecast and potential competition with the forecast adjacent eastern Pacific disturbance. The long range fate of Julia is an interesting question... (1) does it re-generate to the southwest and continue on as an eastern Pacific tropical cyclone offshore of southern Mexico?... (2) does the adjacent disturbance to the southwest become an eastern Pacific tropical cyclone of a different name while Julia simply dissipates?... or (3) do the remnants of Julia become parked over Oaxaca and Veracruz... and eventually merge with the tail end of the cold front to be driven into the Bay of Campeche by the forecast sprawling North American frontal cyclone to become a Bay of Campeche tropical disturbance? In the third scenario... it is also not clear at this time if the NHC would consider the Bay of Campeche disturbance as Julia or a system of a different number/name... that will depend on if Julia can keep a distinct circulation throughout the process.
Regarding impacts to land areas:
(1) Preparations for Julia across Nicaragua should have been completed by now as weather conditions have deteriorated. Wind damage is expected on the east-central Nicaragua coast... with coastal storm surge being the strongest just north of Julia's center. The remainder of the coast can expect sea swells... and much of Nicaragua including inland areas may see tropical storm force gusts with scattered damage potential. Heavy rainfall with flash flooding and mudslide potential is another expected hazard for today.
(2) Heavy rainfall with flash flooding and mudslide potential is likely to spread across Honduras... El Salvador... Guatemala... and the Mexican provinces of Chiapas and Oaxaca for the remainder of this weekend and through the middle part of this upcoming week. Gusty winds are also possible along the coast El Salvador... the south-facing eastern Pacific coast of Guatemala... and the Gulf of Tehuantepec coast of Mexico.
Update as of 2 AM EDT... Julia is now a stronger category 1 hurricane with 85 mph maximum sustained winds and a 982 mb central surface pressure while centered at 12.5N-83.3W. This places the center of Julia just offshore of east-central Nicaragua... landfall is expected within the next couple of hours and therefore this will likely be the landfall intensity of the hurricane.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (0000Z Oct 9)...75 mph maximum sustained wind hurricane centered offshore of the Nicaragua east coast at 12.5N-82.7W
IOH 24 Hr Forecast (0000Z Oct 10)...30 mph maximum sustained wind tropical depression centered on the eastern Pacific coast of Honduras at 12.8N-87.5W
IOH 48 Hr Forecast (0000Z Oct 11)...30 mph maximum sustained wind tropical depression centered on the eastern Pacific coast of Guatemala at 14N-91.2W
IOH 72 Hr Forecast (0000Z Oct 12)...35 mph maximum sustained wind tropical depression centered just offshore of the Oaxaca province of Mexico and in the Gulf of Tehuantepec at 15.5N-95W
IOH 96 Hr Forecast (0000Z Oct 13)...Remnant trough over northwestern Oaxaca located near 17.5N-97W
...COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/)
1200Z (Oct 8) CMC Model Run...
**For Hurricane Julia... makes landfall on the east-central coast of Nicaragua at 18 hours... weakens to an inland remnant low over the southern Honduras/Nicaragua border at 36 hours... remnant low loses identity on the coast of El Salvador at 48 hours within larger broad tropical low pressure area developing just to the west in the eastern Pacific... the broad tropical low moves northwest into southeastern Mexico and dissipates by 102 hours.
1200Z (Oct 8) ECMWF Model Run...
**For Hurricane Julia... makes landfall on the east-central coast of Nicaragua between 24 and 48 hours... located over central Nicaragua as an inland tropical storm at 24 hours... located just offshore of the El Salvador/Guatemala border at 48 hours as a remnant low... remnant low weakens to a trough which reaches the eastern Pacific waters offshore of southwestern Mexico at 120 hours near 15.5N-103W
1800Z (Oct 8) GFS Model Run...
**For Hurricane Julia... makes landfall on the east-central coast of Nicaragua at 15 hours... weakens to a remnant low while reaching the eastern Pacific coast of Central America at the Nicaragua/Honduras border at 24 hours... remnant low loses identity in Gulf of Tehuantepec at 84 hours within north side of larger broad tropical low pressure area developing just to the south in the eastern Pacific (this broad tropical low forecast to develop into a tropical cyclone in the long range).
1800Z (Oct 8) NAVGEM Model Run...
**For Hurricane Julia...makes landfall on the east-central coast of Nicaragua at 18 hours... enters the eastern Pacific as a tropical depression and from western Nicaragua at 30 hours... however loses identity offshore of El Salvador by 42 hours within east side of larger broad tropical low pressure area developing just to the west in the eastern Pacific.
**Tropical wave emerges from west coast of Africa at 120 hours... organizes into offshore tropical low near 11.2N-17.5W at 126 hours... tropical cyclone formation suggested near 13N-20.5W at 150 hours... strengthening tropical cyclone located just southeast of the Republic of Cabo Verde Islands at 168 hours.