The weather pattern over Micronesia during this USDM week (11/06/19-11/12/19) consisted of several weak circulations, surface troughs, and tropical disturbances. A monsoon trough set up across western Micronesia and stretched eastward across the region by week's end. By the end of the week, a circulation near Kwajalein intensified into Tropical Depression 26W (then later, as it moved west, into Tropical Storm Fengshen) while a circulation near Koror developed into Tropical Depression 27W. South of the equator, a surface trough swept across the Samoan Islands during the week, but high pressure tended to dominate. Satellite-based estimates of 7-day precipitation (QPE) showed areas of 2+ inches of precipitation across parts of the Federated States of Micronesia (FSM) and Marshall Islands (RMI), with areas of less than an inch across other parts of Micronesia. Less than half an inch of rain was indicated on the QPE for much of the Samoan region, with half an inch to an inch over parts of American Samoa.
The past week in American Samoa was relatively dry, with rainfall totals of 1.22, 0.40, and 0.50 inches (with one missing day) at Pago Pago, Siufaga Ridge, and Toa Ridge, respectively. However, periods before this week have been wet enough to preclude abnormal dryness from developing.
4.94 inches of rain fell in Palau this week, bringing the November total to 9.39”. Palau remained free of drought or abnormal dryness.
A drier week took place on Saipan, with rainfall measurements ranging from 0.76 to 1.22 inches. However, given large rainfall amounts in September and October, abnormal dryness has not developed there yet. In the last two weeks, Rota received 1.07 and 1.88 inches of rain, so drought-free conditions continued there. In Guam, 2.67 inches of rain fell this week, so drought-free conditions also continued there.
Conditions on Yap were drier this week with only 0.41 inches of rain reported, though two days of data were missing. However, October precipitation reached 8.22 inches and rainfall last week reached 3.17 inches, which is keeping conditions from becoming abnormally dry. No data was reported for Ulithi or Fananu, so no Drought Monitor depictions are being made in either place this week. Short-term abnormal dryness continued at Woleai; however, 3.98 inches of rain fell there this week, so conditions have improved some. At Chuuk, rainfall this week totaled 1.33 inches, while last week’s rainfall totaled 3.23 inches. Given the context of a very dry last two weeks of October, some short-term dryness is beginning to occur there, but it is not yet at the level of abnormal dryness. At Lukunor, 1.44 inches of rain fell this week (with one day of missing data), and abnormally dry short-term conditions continued there. Only 0.82 inches of rain fell in Nukuoro this week, but given that last week’s rainfall exceeded 2 inches and October rainfall exceeded 10 inches, short-term conditions are not yet abnormally dry. In Kapingamarangi this week, 1.78 inches of rain fell, but given that the previous three weeks exceeded 2 inches and October rainfall was 10.22 inches, drought-free conditions continued there. Last week in Pohnpei, 12.86 inches of rain fell, and 4.63 inches fell this week, bringing November totals to 17.04 inches, more than double their normal monthly total for November. No data were available for Pingelap this week, so no drought depiction was made there. In Kosrae, 4.39 inches of rain fell this week, and drought-free conditions continued.
In Kwajalein, 2.05 inches of rain fell this week, and drought-free conditions continued there. At Ailinglaplap, 1.28 inches of rain fell this week, but 5.54 inches fell last week, so drought-free conditions continued here. Short- and long-term severe drought continued at Jaluit this week, though 2.30 inches of rain fell this week, so the short-term has become a little wetter. At Utirik, 2.34 inches of rain fell this week, so drought-free conditions continued. In Wotje, 3.41 inches of rain fell this week, and drought-free conditions continued. Majuro received 2.66 inches of rain this week, and drought-free conditions continued. 4.13 inches of rain fell in Mili this week, and drought-free conditions continued.