Tropical Storm Nalgae can't seem to get a break from vertical wind shear. The storm has been dealing with wind shear since it formed and NASA's Terra satellite observed that was still the case on August 4.
On August 4, 2017 at 0210 UTC (Aug. 3 at 10:10 p.m. EDT), NASA's Aqua satellite passed over the Northwestern Pacific Ocean and the Moderate Resolution Imaging Spectroradiometer or MODIS instrument captured a visible-light image of the storm. The image revealed that Nalgae's strongest thunderstorms were being pushed north of the large low-level circulation center due to increasing southerly vertical wind shear.
On August 4, 2017 at 11 a.m. EDT (1500 UTC), Nalgae's maximum sustained winds were near 46 mph (40 knots/74 kph). Nalgae was centered near 31.3 degrees north latitude and 162.7 degrees east longitude, about 561 nautical miles northeast of Minami Tori Shima. Nalgae has tracked to the north-northwestward at 10.3 mph (9 knots/16.6 kph).
Nalgae is tracking along the western edge of a low- to mid-level subtropical ridge of high pressure (an elongated area of high pressure) located to the east and northeast of the tropical cyclone. Therefore, Nalgae is forecast to continue moving northwest. The Joint Typhoon Warning Center said the system will intensify to 52 mph (45 knots/83 kph) before becoming extra-tropical in the next day.