Latest Seasonal Assessment -
Most drought-affected areas in the western states and Rockies should continue to experience moderate hydrologic
drought through February 2006, with some limited periodic improvement. The only exceptions are central Idaho, where
improvement may be more substantial and widespread, and parts of Arizona and New Mexico, where improvement seems less
likely. Farther east, moderate to extreme drought should continue from the Wyoming High Plains eastward through most
of northern Illinois, in portions of South Dakota, and across central and southern Texas. Winter is typically drier
than other seasons in these areas, so the chances for substantial drought improvement are small. Drought should also
continue to affect portions of the Great Lakes region, and a broad swath from eastern Texas northeastward through
Tennessee and Kentucky, but with decent chances for periodic, limited improvement. Lake-effect and lake-enhanced
snowfall is common and should at least temporarily ease drought impacts in the Great Lakes region at times, and a
climatological increase in storminess from the southeastern Great Plains to the Upper South should bring opportunities
for drought-easing precipitation to the region later in the period. Elsewhere, the entrenched drought and attendant
local water shortages in the Carolinas should persist and might worsen as winter progresses, and farther south, some
antecedent dryness and expected below-normal December 2005 - February 2006 precipitation should combine to spread
drought into southern South Carolina, central and interior southern Georgia, southeastern Alabama, and most of
Tools used in the Drought Outlook
included the official CPC long-lead precipitation outlook for December 2005 - February 2006, the drought termination
and amelioration probabilities for February 2006, various medium and short-range forecasts and models such as the
6-10 day and 8-14 day forecasts, and the soil moisture tools based on the GFS model and the Constructed Analogues for
For areas from the Rockies westward to
the Pacific Coast, substantial precipitation during the cold half of the year is critical. Ideally, snow piles up on
the higher elevations before melting slowly as spring progresses, refilling the streams, rivers, and reservoirs that
serve as the region's primary water sources. So far, the 2005-2006 water year is off to a good start in most areas
currently experiencing moderate to severe drought (as depicted in the Drought Monitor). Most basins are at least
slightly wetter than normal through November 16, 2005, with 125 to 160 percent of normal precipitation reported in
southern and interior eastern Oregon, central and southern Idaho, western and southern Montana, and northwestern
Wyoming. However, the water recharge season is only about 6 weeks old, and with a vast majority of the season still
to come, the current short-term wetness will mean next to nothing if below-normal precipitation occurs during the
next few months. Therefore, precipitation from the Rockies westward during this forecast period is critical and will
be closely monitored. Unfortunately, below-normal precipitation is forecast throughout the region during the next 2
weeks, and the forecast models and statistical indicators for the ensuing 3 months (December 2005 - February 2006) do
not consistently favor any particular scenario. As a result, the Drought Outlook for this region was largely driven
by current conditions, the anticipated dryness during the next couple of weeks, and December - February climatology,
all of which boils down to a forecast of continuing drought with some temporally and spatially limited improvement.
Substantial drought relief by February 2006 is possible, but drought intensification is equally possible. It will
depend on how the next several months unfold as a whole. It should be noted that, climatologically, chances for
substantial drought improvement in the Washington Cascades are considerably higher than for most other drought-affected
areas in the West, but with drier than normal conditions expected for the next couple of weeks, and with none of the
tools strongly indicating wetter than normal December - February precipitation in the region, the area of expected
improvement in last month's Drought Outlook was removed.
There are two exceptions to the limited-improvement
forecast made for most of the West. First, improvement is being forecast for much of Idaho, where reports indicate
that drought-related impacts are not as severe nor as widespread as in some other areas. Second, drought persistence
or intensification is forecast for the drought-affected areas in Arizona and New Mexico, consistent with the
consensus of the tools.
Farther east, drought is forecast to
persist in a swath from the Wyoming High Plains eastward through most of the northern tier of Illinois, where drier
than normal conditions are expected during the next 2 weeks. There are no strong indicators for either above- or
below-normal December - February precipitation per se, but since this is a relatively dry time of year (particularly
in the High Plains) and there are no indicators strongly pointing toward wetter than normal conditions, substantial
drought relief seems unlikely by the end of February.
In the central and southern Great Lakes
region, climatology indicates that a substantial reduction of long-term moisture deficits is unlikely by February,
and the next 2 weeks are expected to be drier than normal. However, winter precipitation climatologically accounts
for a larger proportion of the annual total here than in areas farther west, and additionally, with lake-effect and
lake-enhanced snowfall relatively common, it seems likely that at least a temporary reduction of some drought impacts
should occur over the course of the next few months.
Drought is expected to persist or
possibly worsen across central and southern Texas. Winter is typically a relatively dry time of year for the region
(at least until late in the period), and none of the objective indicators point toward widespread above-normal
precipitation for the next 3.5 months.
In the swath of drought extending from
eastern Oklahoma eastward through Tennessee and Kentucky, drought is expected to continue, but with a fair chance for
limited improvement at times during the next few months. Moderate rains have already fallen since the last valid
Drought Monitor issuance across Kentucky and Tennessee, which may lead to some areas of in next week's issuance. The
last half of November looks to be drier than normal throughout the region, and thereafter, December - February
precipitation indicators are mixed in the ArkLaTex region, and generally indeterminate across Kentucky and Tennessee.
However, precipitation is climatologically on the upswing throughout the region during February, so a forecast was
made that allowed for some chance of at least short-lived drought improvement.
Drought has become well entrenched across
the Carolinas during the last few months, with short water supplies and mandatory water usage restrictions in place
for several locales. The objective indicators point toward near- to below-normal precipitation for the next 3.5
months, and given the long-term nature of the moisture shortages affecting the region, relief seems unlikely and
drought is forecast to persist or worsen through February 2006.
Finally, drought is expected to develop
across much of southern South Carolina, central and interior southern Georgia, southeastern Alabama, and northwestern
Florida by February 2006. This region is classified as abnormally dry in the most recent Drought Monitor, and a vast
majority of indicators, including the official December 2005 - February 2006 outlook issued by the Climate Prediction
Center, favor below-normal winter precipitation across the region.