Hurricane Guillermo was downgraded to a tropical storm as it continued its course toward the Hawaiian Islands.

According to the Central Pacific Hurricane Center in Honolulu, Guillermo was about 620 miles away from Hilo, Hawaii, on Monday morning. Its track is expected to take it near or over the islands on Wednesday and Thursday. The storm is expected to continue to weaken.

The exact track of the storm will dictate which islands are impacted most. Dangerous surf, significant rainfall and high winds are expected, and forecasters warn of the chance of coastal and flash flooding.

The storm currently has maximum sustained winds near 70 mph. There are no warnings or watches currently in effect, but forecasters say advisories may be issued for certain portions of the state later Monday.