Tools used in the monthly U.S. Drought Outlook (MDO) included the official CPC temperature and precipitation outlooks for
October 2013, various short- and medium-range forecasts and models such as the 6-10 day and 8-14 day forecasts, the NAEFS and ESRL precipitation outlooks, the soil
moisture tools based on the Constructed Analog on Soil (CAS) moisture, dynamical models (CFSv2, NMME, and IMME),
the 384-hour total precipitation forecasts from several runs of the GFS, the 7-day quantitative precipitation forecast from the NCEP
Weather Prediction Center (WPC), climatology, and initial conditions. ENSO Neutral conditions are expected to continue through the fall.
Drought coverage and intensity remained nearly steady during September across the eastern Dakotas, Minnesota, Wisconsin, Iowa, and northern
Missouri with some improvement across Illinois. Removal (D1 areas represent by the USDM) or improvement (D2 areas represented by the USDM)
across the South Dakota, Minnesota, Wisconsin, and northern Iowa is based largely on expected precipitation during the first week of
October. The ESRL precipitation tool for the 6-10/8-14 Day periods also indicates enhanced odds for above median precipitation. South of
the predicted storm track during early October, persistence is forecast for southern Iowa, northern Missouri, and Illinois.
Forecast confidence for the Midwest is moderate.
Since the beginning of September, drought improvement occurred across western parts of Nebraska and Kansas along with the Oklahoma
Panhandle, while abnormal dryness expanded across eastern Oklahoma. Additional improvement during October is not expected for most of the
central and southern Great Plains since October is a relatively dry month and the CPC October outlooks calls for increased chances of below
median precipitation. The exception is western Nebraska where a storm at the beginning of October could result in small areas of
Forecast confidence for the central and southern Great Plains is high but low for western Nebraska.
Drought improvement occurred during the latter half of September across central/south Texas, southwest Louisiana, and parts of Mississippi
while drought intensity remained steady across northern Texas and southern Arkansas. The first week of October is expected to be dry across
Texas, but a disturbance across the northern Gulf of Mexico may bring more rain and lead to drought removal across southern Louisiana. The
enhanced phase of the MJO is expected to progress into the Western Hemisphere later in October. Precipitation composites associated with
the expected evolution of the MJO favor improvement or removal of drought along the western/ central Gulf Coast and lower Mississippi
Valley. This is consistent with the CPC October precipitation outlook calling for enhanced odds for above median precipitation across these
Forecast confidence for Texas and the lower Mississippi Valley is moderate.
Due exceptionally high rainfall amounts during early-to-mid September, drought ended across northern Colorado. A very active late monsoon
brought major improvements to the remainder of the Southwest. Precipitation during the first week of October is expected to be limited to
the drought-free areas of northeast Colorado with mostly dry weather forecast for much of the Southwest. Therefore, persistence is likely
for this region as rainfall associated with the monsoon ends.
Forecast confidence for the Southwest is high.
WPC 1-7 day precipitation forecasts indicate moderate to heavy precipitation associated with an upper-level trough across the northern
Rockies. Improvement or removal of drought across parts of the northern Rockies is based primarily on this short-term precipitation
although the ESRL 6-10 day precipitation on September 30 indicates a tilt in the odds towards above median precipitation for this region.
Forecast confidence for the northern Rockies is moderate.
Heavy precipitation affected the Pacific Northwest at the end of September. Climatology and precipitation tools during the beginning of
October favor removal of short-term moderate drought in southwest Oregon and improvement to the severe drought in extreme northwest
California. Further south, precipitation typically increases later in the fall season across the remainder of California. Therefore,
persistence is forecast for central and southern California.
Forecast confidence for the West Coast is high.
The interior parts of central Alaska received near to above normal precipitation during September, while precipitation averaged below
normal across a small area of southeast interior Alaska. The October drought outlook is based on trends observed in September and near to
above median precipitation favored during early-to-mid October.
Forecast confidence for Alaska is moderate.
Climatology favors persistence across Hawaii although the onset of the rainy seas is approaching. Development is not forecast during the
1-month time period covered by this outlook.
Forecast confidence in Hawaii is moderate.