was accompanied by steady strengthening, and Laura was upgraded to a Category 1 hurricane at 12:15 UTC on August 25 after hurricane hunters found hurricane-force winds at the surface. Laura then developed an inner core and a central dense overcast (CDO), although it still had a somewhat ragged appearance on satellite imagery. Its intensification continued to be slow due to the presence of some dry air and light northerly wind shear, but this eventually subsided, allowing Laura to become more organized and form a banding-type cloud-filled eye late on August 25 with its sustained winds reaching by 00:00 UTC on August 26. With no more negative factors hindering strengthening and sea surface temperatures around 30 °C, Laura began to rapidly intensify, becoming a Category 2 at 06:00 UTC before achieving Category 3 status just six hours later, making it the first major hurricane of the season. By this time, Laura was beginning to make a gradual northward turn in between the high-pressure ridge over the Southeastern United States and a mid-level low near Oklahoma. As the day progressed, Laura's eye continued to clear out and the deep convection around it intensified and became more symmetric. The satellite presentation continued to improve with the eye becoming better defined, and cloud tops colder than -70 °C in the surrounding ring of deep convection in the developing eyewall. Laura continued to rapidly strengthen that afternoon and reached Category 4 intensity at 18:00 UTC. The hurricane's eye reached a diameter of that evening and aircraft reconnaissance indicated it to have acquired sustained winds of by 21:00 UTC; this represented an increase of over a 24-hour period. Laura's structure continued to improve with a very distinct, 25 nautical-mile-wide eye embedded in a symmetric central dense overcast and upper-level outflow becoming well established in all quadrants of the cyclone. As it turned north-northwestward towards the Louisiana coastline, Laura reached its peak intensity at 00:00 UTC on August 27 as a high-end Category 4 hurricane with 1-minute sustained winds and a minimum central pressure of 937 mbar (hPa; 27.67 inHg), as measured by reconnaissance aircraft. At this point, the hurricane was located south of Lake Charles, Louisiana and south-southeast of Port Arthur, Texas by a distance of each. Laura's rapid intensification then ended and its intensity more or less leveled off as it approached southwestern Louisiana. Laura also began to experience some shear from the low to