Discussion for the Seasonal Drought Outlook
Tools used in the Drought Outlook included the
official precipitation outlook for November-January, various medium- and short-range forecasts
and models such as the 6-10 day and 8-14 day forecasts, the soil moisture
tools based on the GFS model and the Constructed Analogue on Soil (CAS) moisture, and climatology.
The outlook for the Southeast reversed the pattern
shown in the previous outlook, with some improvement now in the Ohio and Tennessee Valleys and persistence to
the south. This results from the November-January CPC precipitation outlook showing the odds tilting dry south
and east of Tennessee, with equal chances wet or dry to the north. Above-normal rains forecast for the 6-10 and
week 2 periods during the last half of October favor at least some improvement for the Kentucky and Tennessee
area, with the most recent GFS model runs on October 15 showing heavy rains later in the month into central and
southern Georgia. River forecasts based on climatology suggest that significant improvement in the Ohio Valley
is not likely over the next 90 days, so no areas of straight improvement are depicted. To the south, the
Outlook depiction tried to strike a balance between a wetter medium-range forecast and a drier long-range
forecast. Climatology and the seasonal rainfall forecast support the idea of drought expansion into northern
Florida. Near-drought conditions already exist in the Tampa area.
Two-week forecasts suggest normal to
above-normal rains should ease drought in Pennsylvania and coastal North Carolina, so improvement is shown for
both of these small areas.
The dry seasonal forecast is the driving force
behind the persistence forecast for the Texas drought, but the first few days of the period offer considerable
rainfall to at least coastal areas, so improvement is shown along the coast.
Recent rains have improved the drought in southeast
Colorado and western Oklahoma, and additional moisture forecast in the first 10 days of the period should come
close to ending drought.
For the drought in Wisconsin and southeast and
northeast Minnesota, above-normal rainfall forecast for the first 2 weeks is the main reason for depicting
improvement. Recent rains have made the remaining drought very marginal in Minnesota, so confidence is
relatively high for ending drought there. In northeastern and central Wisconsin, however, soil moisture and
runoff forecasts based on ESP (Ensemble Streamflow Prediction) indicate a tendency for drought to persist, so
confidence is low for that area.
Confidence: High for Minnesota. Low for Wisconsin.
In the West, the forecast is similar to the
previous forecast, with some expansion of the improvement area in California due to historical trends going
Confidence: Moderate except high for northern California.
In Hawaii, no changes were made to the previous
outlook, with development forecast in some leeward areas and persistence elsewhere.