Tropical Cyclone 03W Guchol / Tropical Cyclone 02A (Biparjoy) / Invest 99W
Sunday, June 11, 2023

Current Snapshot

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By PDC’s Senior Weather
Specialist Glenn James

Current Tropical Cyclones:

Tropical Cyclone 03W (Guchol)…is located approximately 458 NM south-southwest of Yokosuka, Japan

Tropical Cyclone 02A (Biparjoy)…is located approximately 326 NM south of Karachi, Pakistan


Northeast Pacific Ocean:

There are no tropical cyclones…nor any areas of disturbed weather under investigation by the National Hurricane Center (NHC)

Tropical cyclone formation is not expected during the next 7-days.


North Central Pacific Ocean:

There are no tropical cyclones…nor any areas of disturbed weather under investigation by the Central Pacific Hurricane Center (CPHC)

Tropical cyclone formation is not expected during the next 7-days.


Northwestern Pacific Ocean

Tropical Cyclone 03W (Guchol)

According to the JTWC Warning number 25, sustained winds are 50 knots…with gusts to near 65 knots

Animated enhanced infrared satellite imagery depicts a central dense overcast with deep convection limited to the eastern semicircle. A recent microwave imagery reveals greatly reduced deep convective activity and worsening vertical tilting due to persistent shear.

TS 03W is forecast to continue its gradual turn northeastward through the forecast period. As the system tracks poleward, a classic battle between improving outflow, cooling sea surface temperatures and increasing vertical wind shear will begin.

Over the next 12 hours, as the negative effects of persistent moderate vertical wind shear and mid level dry air entrainment continue to plague the systems structural integrity. the outflow channel to the east will cutoff and the system will instead begin to tap into the jet stream to the north.

During this same time however, vertical wind shear and dry air entrainment will increase and sea surface temperatures will continue to fall. The results of this will be initially gradual weakening that will worsen with time. As the system interacts with the jet stream, the high shear values will tear the system apart and quickly progress 03W through sub-tropical transition (stt) through 36 hours.

As the system speeds off to the northeast, it will be stripped of all remaining tropical characteristics and eventually complete extra-tropical transition by 72 hours, all the while continuing to weaken.


Arabian Sea

Tropical Cyclone 02A (Biparjoy)

According to the JTWC Warning number 24, sustained winds are 85 knots…with gusts to near 105 knots

The last few frames of animated multi-spectral satellite imagery depicts a once again waning central dense overcast that is devoid of the nascent eye feature from just a few hours ago. A microwave image indicates the same waxing and waning convective signature that has played out over the past several days.

TC 02A is forecast to continue generally northward under the steering influence of the ridge to the east. Currently in a marginal environment, 02A has demonstrated a proclivity for intensification despite nearly 30 knots of vertical wind shear.

Over the past six hours, 02A has once again visibly weakened and as shown in microwave imagery resumed a slight vertical tilt. As this is not the first time 02A has cycled in this fashion, if the system can regain its organization while the outflow path to the west is available, the possibility for short term intensification through 12 hours cannot be ruled out.

As the system progresses poleward, the westward outflow channel is cutoff and replaced with subsidence aloft, which together with nearly 30 knots of vertical wind shear and dry air entrainment will weakening the system through 72 hours. After 72 hours, the system will turn northeastward and make landfall as the ridge reorients. Through the forecast period the system will be eviscerated as it proceeds inland, rapidly weakening to 40 knots by 120 hours.


Western Pacific Ocean

>>> There’s an area of disturbed weather being referred to as Invest 99W…which is located approximately 41.6 NM west of Haikou, Hainan Island

Animated multi-spectral satellite imagery and animated radar imagery depict a disorganized low level circulation center (llcc).

The environment is marginally favorable for development with robust equatorward outflow, low (5-10 knot) vertical wind shear, and very warm sea surface temperatures.

Interaction with land will hinder development and global models are in general agreement that invest 99W will track southward and eventually eastward not developing over the next 24-48 hours.

Maximum sustained surface winds are estimated at 13 to 17 knots.

The potential for the development of a significant tropical cyclone within the next 24 hours remains low.