HONOLULU (KHON2) - Sunday's highest probabilities for the regeneration of showers will be further up the chain as the remnants of today's eastern convergence zone treks northwestward toward the western half of the state. An approaching cold front associated with low pressure far north of the Hawaiian Islands is pulling a southern band of rich moist air up and over the eastern half of the state. The highest chances for more frequent periods of rain, with another round of afternoon thunderstorms just north of the islands, will be centered around windward Oahu and Kauai Sunday. Due to slow cell movement, a quick 1 to 2 inches of rain over a short amount of time is not out of the question. Higher mid layer moisture will stick in place downstream of the approaching shallow cold front Sunday into Monday. As the low way up north is absorbed by a larger scale trough, the central or eastern water low level boundary will fizz out and merge with Monday's front as it progressively passes southeast across Kauai. Breezy northerlies will fill in the front's wake through Monday. Shower activity will favor northern and eastern exposures of each island through the Monday through Tuesday frontal passage. The front will diminish into a trough and likely stall near Big Island and Maui late Tuesday into Wednesday. This boundary will then slowly lift northward as more unstable southerly flow begins to develop by late Wednesday. The extended NWP guidance has been consistent in holding onto the solution of a developing mid to upper trough within a northwest flow pattern going into the middle of next week. As this trough deepens and moves into the islands, this will favor lower pressures evolving in the close proximity of Hawaii.