Heavy to excessive rainfall resulted in a decrease in drought coverage across the central and southern Great Plains, parts of the Southeast and Mid-Atlantic (associated with Hurricane Michael) during October. Drought persisted across much of the western U.S. and northern Great Plains during the past month. Much of the eastern U.S. remains drought-free except for small areas of the Southeast, New York, and Vermont.
The monthly drought outlook valid for November 2018 is based on 7-day precipitation forecasts, extended range (6-10/8-14 day) precipitation and temperature outlooks, the CPC updated November precipitation and temperature outlooks, and climatology. Recent rainfall and soil moisture forecasts from the GFS model were also considered.
Forecast Heavy rain during the first two weeks of November across the eastern half of the continental U.S. along with the CPC monthly outlook indicateing enhanced odds for above normal precipitaiton favor drought improvement or removal of drought across the central and eastern CONUS.
Improvement and removal of drought are forecast for parts of the Pacific Northwest and northern Rockies where heavy precipitation is likely during early November and the monthly outlook also favors above normal precipitation over the areas. Improvement or removal of drought across the Dakotas is based on recent precipitation and the monthly outlook favoring above normal precipitation during November.
Peristence is forecast for California as the heaviest precipitation is expected to remain north of the state through November. Precipitation on a monthly time scale is not expected to be high enough for improvement across the long-term drought areas of the Four Corners region. Drought removal or improvement is expected across parts of southeast Colorado and New Mexico based on recent and ongoing precipitation. Also, the CPC monthly outlook indicates a slight tilt in the odds for above normal precipitation.
Improvement or removal is expected along the Alaska Panhandle due to a wet climatology and favorable extended range forecasts to monthly outlook. The Hawaiian Islands and Puerto Rico are forecast to remain drought-free through the end of November.
Forecast confidence is high for the Pacific Northwest, California, and the desert Southwest and moderate for the Great Basin.
Drought improvement is expected across the Pacific Northwest, parts of the Northern Intermountain and the Northern Rockies, due to recent heavy rainfall, the WPC 7-day precipitation forecast indicating widespread 1 to 5 inches across the Pacific Northwest and CPC monthly outlook favoring above normal precipitation over these areas.
- Broad scale persistence is forecast for the remainder of the West since precipitation during the next month is not expected to be sufficient for improving long-term drought.
Forecast confidence for the High Plains Region is moderate.
- Recent rainfall and forecasted above normal precipitation over much of the High Plains from the extended range forecasts to monthly outlook favor one class drought improvement for the Dakotas, eastern Colorado and northeast Kansas.
- Persistence is more likely over central and western Colorado due to very dry initial conditions (28-day streamflows and soil moisture ranking in the lowest 10th percentile).
- A relatively dry climatology and predicted lower precipitation amounts during November favor drought persistence across northeast Montana.
Forecast confidence for the Southern Region is moderate to high.
- Recent heavy rainfall resulted in drought reduction across most of Oklahoma and Texas since the beginning of October.
- Both short term forecasts and monthly outlook favor near to above normal precipitation during November over much of the Southern Region. Lingering drought across these areas is expected to be removed.
Forecast confidence is high for central Missouri.
- The WPC 7-day rainfall forecast calls for widespread rainfall amounts of 1 to 5 inches from the middle Mississippi Valley to the Ohio Valley.
- The CPC extended range forecasts and monthly outlook also favor above normal precipitation across these areas. Drought removal is forecast for central Missouri.
Forecast confidence is moderate for the Southeast Region.
- Hurricane Michael made landfall near Mexico Beach, Florida on Oct 10. Michael and its remnant low brought widespread flooding rainfall and reduced drought in Georgia and South Carolina.
- Drought removal is forecast for parts of Georgia and South Carolina where the extended range forecasts and monthly outlook favor above normal precipitation across the Southeast.
- Above-normal temperatures and below normal precipitation during the past month resulted in expansion of abnormal dryness (D0) across the Florida peninsula.
- The latest GFS 384-hour total precipitation forecast calls for 2-3 inches rainfall and the CPC monthly outlook also calls for above normal precipitation over the areas which increases chances to damp drought development across Florida Peninsula.
Forecast confidence is moderate to high for the Northeast Region.
- A small area of moderate to severe drought exists across northern parts of New York and Vermont.
- Based on a favorable time of year for soil moisture recharge, moderate to heavy rainfall during the first week of November, and increased chances of above normal precipitation during the rest of November, improvement or removal of drought is likely.
Forecast confidence is moderate for Alaska.
- Moderate to severe drought continues along the southern Alaska Panhandle. Since both the extended range forecasts and the monthly outlooks call for above normal precipitation for the Alaska Panhandle, removal of D1 or improvement to D2 is forecast by the end of November.
Forecast confidence is moderate to high for Hawaii and Puerto Rico.
- The Hawaiian Islands and Puerto Rico are forecast to remain drought-free.