CURRENT TROPICAL CYCLONES
Tropical Cyclone 26S (Seroja)…is located approximately 384 NM north of Learmonth, Australia
Tropical Cyclone 27S…is located approximately 586 NM northwest of Learmonth, Australia
 
  https://www.metoc.navy.mil/jtwc/products/26S_080000sair.jpg
Tropical Cyclone 26S (Seroja)
Sustained 55 knot winds…with gusts to 70 knots (as of Warning Number 15) Here’s what the computer models are showing According to the JTWC, satellite imagery shows disorganized and fragmented convection flaring just west of the assessed core of TC 26S, indicative of the persistent easterly vertical wind shear. While still marginal, environmental conditions have improved slightly, with CIMSS shear estimates now below 15 knots and water vapor imagery starting show some hints of improved outflow aloft. TC 26S is forecast to continue tracking southwestward along the northwest periphery of a deep-layer subtropical ridge over western Australia through 48 hours, then near 72 hours accelerate southeastward through 120 hours. The system is expected to undergo binary interaction with TC 27S, but as the dominate system, the interaction is not expected to impact the overall track of TC 26S, though some slight westward wobble is possible between 24 and 36 hours. As environmental shear slowly relaxes, slow intensification is forecast through 36 hours. The system is forecast to rapidly intensify from 60 knots to 110 knots between 36 and 72 hours, as an upper-level point wind shear drops below 10 knots and the system taps into a poleward outflow channel. After rounding the ridge axis, the system will rapidly weaken under the influence of convergent flow aloft, increasing shear and cooler waters. As the system makes landfall south of Shark Bay around 96 hours, it will begin extra-tropical transition, and is expected to complete this transition by 120 hours before emerging into the Great Australian Bight.  
https://www.metoc.navy.mil/jtwc/products/27S_080000sair.jpg
Tropical Cyclone 27S
Sustained 40 knot winds…with gusts to 50 knots (as of Warning Number 13) Here’s what the computer models are showing According to the JTWC, satellite imagery shows deep convection once again flaring near the core of the system, and obscuring the low level circulation center. The bulk of the convection remains sheared to the southwest under moderate northeasterly wind shear. By 24 hours TC 27S will move to within 330 NM of TC 26S, be captured by TC 26S and begin binary interaction. Once the system is captured it will accelerate onto a northeast, then east and ultimately southward track, moving progressively closer to TC 26S and ultimately merging with it no later than 96 hours. Moderate east-northeast shear is expected to continue for the next 12-18 hours, which will inhibit near-term intensification. Once the system starts to move north and out from under the outflow emanating from TC 26S, it will experience reduced shear and may for a short time develop its own outflow aloft, allowing for a short burst of intensification through 48 hours. After starting its dive southward after tau 48, the combination of increasingly convergence outflow, increasing shear and disruption of the low level wind field due to interaction with TC 26S, it will begin to rapidly weaken prior to merger with TC 26S.   https://www.nrlmry.navy.mil/htdocs_dyn_apache/PUBLIC/tc_pages/thumbs/medium/tc21/SHEM/91S.INVEST/ir/geo/1km_bw/20210407.142000.SH912021.ahi.himawari-8.Infrared-Gray.20kts.100p0.1p0.jpg There’s a tropical disturbance being referred to as Invest 91S, which is located approximately 326 NM north-northwest of Cocos Islands, Australia Here’s was the computer models are showing According to the JTWC, satellite imagery shows disorganized banding with cycling convection to the south-southwest of a broad low level circulation. Invest 91S is in a marginal environment for tropical development with good poleward outflow aloft and warm sea surface temperatures offset by strong 20-25 knot wind shear. Invest 91S is in a marginal environment for tropical development with good poleward outflow aloft and warm sea surface temperatures…offset by strong 25-30 knot wind shear. Maximum sustained surface winds are estimated at 25-30 knots. The potential for the development of a significant tropical cyclone within the next 24 hours remains low.   https://www.nrlmry.navy.mil/htdocs_dyn_apache/PUBLIC/tc_pages/thumbs/medium/tc21/SHEM/92P.INVEST/ir/geo/1km_bw/20210408.022000.SH922021.ahi.himawari-8.Infrared-Gray.20kts.100p0.1p0.jpg There’s a second tropical disturbance being referred to as Invest 92P, which is located approximately 520 NM east-southeast of Port Moresby, Palua, New Guinea Here’s was the computer models are showing According to the JTWC, satellite imagery shows cycling convection of an obscured low level circulation center. Invest 92P is in a marginal environment for tropical development, with low 5-10 knot wind shear, warm sea surface temperatures…which is offset by weak poleward outflow. Global models are in good agreement that invest 92P will consolidate over the next 24-48 hours, as it tracks to the southeast under an area of weak 15-20 knot wind shear. Maximum sustained surface winds are estimated at 25-30 knots. The potential for the development of a significant tropical cyclone within the next 24 hours is low.   Here’s a link to the Joint Typhoon Warning Center (JTWC)   For real-time information on current disasters download PDC’s free Disaster Alert mobile app available for your iOS or Android devices today! Also be sure to monitor PDC on Twitter, Facebook, and by accessing the web-accessible Disaster Alert from your computer, phone, or tablet.