subj/prognostic reasoning for typhoon 23w (Hagibis) warning nr 20// rmks/ 1. For meteorologists. 2. 12 hour summary and analysis a. Typhoon (TY) 23w (Hagibis) has entered a competing steering environment between subtropical ridging to the north and mid- level near-equatorial riding to the south of the storm. Intensity has decreased over the past 12 hours as a result of increasing easterly vertical wind shear induced by the peripheral winds of a synoptic-scale anticyclone aloft and strong upper level outflow from TY 24w. B. The current storm position is based on satellite fixes from pgtw and rjtd and a 231045z windsat pass. Dvorak T-numbers of 4.0/4.5 from pgtw and 4.5/4.5 from rjtd and a 231200z CIRA multi- platform wind estimate of 75 knots yield a current intensity estimate of 70 knots. Recent enhanced infrared and microwave Sat- ellite imagery indicate that the remaining deep convection associ- ated with TY 23w is sheared to the west of the low level circula- tion center. 3. Forecast reasoning. A. The forecast reasoning has not changed significantly since the previous issue of the prognostic reasoning bulletin. B. TY 23w is forecast to continue weakening under the contin- uing influence of vertical wind shear, low ocean heat content and eventual land interaction. As the system weakens, the steer- ing level will lower and strong low to mid-level easterly to northeasterly flow to the north will pull the weakened system westward. Under this scenario, the storm is expected to make landfall just after tau 48 and, thereafter, dissipate over land. The available numerical model guidance continues to depict an alternate scenario in which the system dissipates over water and the remnants track eastward through the southern south China sea. Given the expected persistence of strong low to mid-level easterly flow to the north of the storm, the alter- Nate track scenario is considered unlikely. The current track forecast direction is close to the shallow Beta-advection model solution which, in this rare instance, is considered more representative of probable future storm motion than the numer- ical model depictions. 4. Justification for correction: corrected storm reference in para 2.A. Forecast team: Delta// nnnn