By PDC’s Senior Weather
Specialist Glenn James
The Pacific Disaster Center’s (PDC Global) Saturday, October 21, 2023, Tropical Cyclone Activity Report…for the Pacific Ocean, the Indian Ocean, and adjacent Seas
Current Tropical Cyclones:
Tropical Cyclone 17E (Norma)…is located approximately 30 miles north-northeast of Cabo San Lucas, Mexico
Tropical Cyclone 01P …is located approximately 458 NM north of Port Vila, Vanuatu
Tropical Cyclone 05A (Tej) …is located approximately 316 NM south-southeast of Salalah, Oman
Northeast Pacific Ocean:
Tropical Cyclone Norma…
HEAVY RAINS AND FLASH FLOODING TO CONTINUE THROUGH THE WEEKEND
According to the NHC advisory number 18
Norma is moving toward the north-northeast near 6 mph (9 km/h). This general
motion should continue through tonight, followed by a turn toward the northeast and east-northeast on Sunday and Sunday night.
On the forecast track, the center of Norma is expected to continue moving across the southern portion of Baja California Sur tonight. Norma is forecast to move toward the west coast of mainland Mexico on Sunday and move inland within the tropical storm warning area on Sunday night or early Monday.
Maximum sustained winds have decreased to near 65 mph (100 km/h) with higher gusts. Continued weakening is expected during the next couple of days, and Norma is expected to approach the west coast of mainland Mexico as a tropical storm.
Tropical-storm-force winds extend outward up to 140 miles (220 km)from the center.
HAZARDS AFFECTING LAND
WIND: Tropical storm conditions are ongoing within the tropical storm warning areas in Baja California Sur. Tropical storm conditions are expected in the warning area along the west coast of mainland Mexico by early Sunday.
RAINFALL: Norma will produce rainfall totals of 6 to 12 inches with maxima of 18 inches across the southern portion of Baja California Sur through Sunday and through Sinaloa into Monday. These rains will produce flash and urban flooding, along with mudslides in areas of higher terrain.
STORM SURGE: A dangerous storm surge is likely to produce coastal flooding in areas of onshore winds within the tropical storm warning area in Baja California Sur. Near the coast, the surge will be accompanied by large and destructive waves. Coastal flooding is possible along the west coast of mainland Mexico within the tropical storm warning area.
SURF: Swells generated by Norma will continue to affect the coast of southwestern and west-central Mexico and Baja California Sur for the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions.
A broad area of low pressure located several hundred miles south of the Gulf of Tehuantepec continues to produce a large area of shower and thunderstorm activity.
The upper-level winds are expected to become more conducive for development of this system during the next couple of days, and a tropical depression is likely to form by early next week.
The system is forecast to meander or drift generally northward through early next week.
* Formation chance through 48 hours…high…70 percent
* Formation chance through 7 days…high…80 percent
Central North Pacific:
There are no tropical cyclones, nor any areas of disturbed weather under investigation by the CPHC at the time of this writing.
Western Pacific, Indian Ocean and adjacent Seas:
Tropical Cyclone 01P
According to the JTWC warning number 2, sustained winds were 40 knots, with gusts to 50 knots
Tropical cyclone 05A is currently undergoing an eyewall replacement cycle (erc) with concentric eyewalls and a well-defined moat feature evident in the microwave image. After an impressive 24-hour period of extreme rapid intensification, animated enhanced infrared (eir) satellite imagery depicts a more asymmetric appearance with rapidly fluctuating core convection.
TC 05A is forecast to track generally northwestward along the southwest periphery of the ridge through the forecast period. The ongoing erc presents some challenges with some weakening possible over the next 6 hours. However, due to the highly favorable environment, the system is expected to intensify through 12 to 24 hours to a peak intensity of 125 knots.
After 24 hours, dry air off the Arabian Peninsula will begin to entrain into the western and southern peripheries of the system, with steady weakening until landfall near 48 hours. The microwave brightness temperature forecasts indicate rapid erosion of the eyewall over the southern semicircle.
However, strong deep convection and heavy rainfall amounts are expected at landfall over the northern semicircle. After 48 hours, TC 05A will rapidly weaken as it tracks inland with dissipation by 96 hours.
Tropical Cyclone 05A (Tej)
According to the JTWC warning number 7…
The system had sustained winds of 105 knots, with gusts to 130 knot
North Indian Ocean
>>> There’s an area of disturbed weather being referred to as Invest 92B…which is located approximately 318 NM southeast of Visakhapatnam, India.
Enhanced infrared satellite imagery and a microwave image depict a consolidating, partially exposed low-level circulation center (llcc) with deep, flaring convection over the center and formative banding wrapping into the llcc.
Environmental analysis indicates that 92B is in a favorable environment for development with good outflow aloft, low (5-10 knot) vertical wind shear, and warm sea surface temperatures.
Global models are in good agreement that 92B will be quasi-stationary as it continues to develop before starting a northward track at around 48 hours.
Maximum sustained surface winds are estimated at 20 to 25 knots.
The potential for the development of a significant tropical cyclone within the next 24 hours is medium.