Since late August, the Drought Monitor indicates worsening dryness and drought prevailed across the central and eastern U.S., though there were some pockets of improvement. In particular, parts of the northern Plains, the Great Lakes region, the central and western Gulf Coast, Georgia, and southern Florida bucked the trend and showed more areas of improvement than deterioration.

In contrast, drought conditions eased in more than half of the dry areas in Alaska and Puerto Rico. In addition, improvement was significant and widespread across Hawaii, where excessive rains fell in association with two tropical systems. Reports of 10 times normal or more since late August were not uncommon, and drought is now relegated to small areas in southern sections of Kauai, Maui, and the Big Island.

Drought persisted with little deterioration or improvement from the Rockies to the Pacific Coast. Locally heavy rain brought pockets of improvement to western Washington, southern Idaho, southern and eastern Montana, and the southern Rockies while deterioration was limited to much of central Montana.

The October Drought Outlook is based on initial conditions, the updated October precipitation and temperature outlooks, climatology, and the expected effects of Hurricane Joaquin in the East. Located about 200 miles east-northeast of the central Bahamas on midday September 30, Joaquin is expected to meander westward or southwestward for the next couple of days before taking a turn to the north, with an increase in forward speed. Its eventual impact on the eastern U.S. will depend on how it interacts with a developing upper-level trough in the Southeast. Regardless of its track, heavy rain is expected along a frontal system at the beginning of October across parts of the East.

As far as the October Drought Outlook is concerned, improvement is expected in the East whether or not Joaquin makes landfall. Other short-term features, most notably and upper-level trough developing in the Southeast, should bring enough rain to promote improvement in any case. Joaquin is not likely to affect southern  Florida at all, but moderate short-term rains and the potential for additional precipitation later in the month should continue the trend toward improvement that has been observed over  the past several weeks.

In fact, most of the central and eastern U.S. should see at least some drought improvement, save the small area in southern Wisconsin, where the October precipitation outlook shows enhanced chances for below-normal precipitation.

Even more broadly, the first half of the month is expected to be wetter than normal for a large part of the contiguous 48 states. Only parts of the Southwest and Southeast are excluded from the generally wet outlook, and late September rains should be enough to promote improvement in the Southeast even if the region misses out on the anticipated wet spell. For the month as a whole, odds favor wetter than normal weather from most of the Four Corners states southeastward through Texas and Louisiana.

Drought is expected to persist from the Rockies westward despite expected above-normal rain early in the month outside central and southern California, and for the  month as a whole in most of the Four Corners states. Drought dates back longer than in most of the East, and with the water year just getting underway, any precipitation should have negligible impact on the longer-term situation.

Drought is forecast to be removed from both Hawaii and Alaska by the end of the month, but should persist in central and eastern Puerto Rico. Enhanced rainfall may affect the Commonwealth next week, but there is a lot of uncertainty, and it is unlikely there will be widespread improvement.
     
Forecaster: Rich Tinker

Next Monthly Drought Outlook issued: October 31, 2015 at 3:00 PM EDT