 Over the next several days, Bilis moved generally northwestward toward Taiwan, slowly strengthening over open waters.Bilis was designated a severe tropical storm by the JMA on July 11, but the storm did not strengthen much further over the next few days due to a marginal upper-air environment and dry air entrainment.PAGASA upgraded the system to typhoon status on July 12, but the JMA never officially recognized the system as such in its advisories.