Tools used in the Drought Outlook included the
official precipitation outlook for February-April, 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.
In recent weeks, heavy precipitation has fallen
across much of the Eastern US, with Kentucky and West Virginia now above normal for precipitation for the
past 30 days. The last vestiges of drought across northern Kentucky were erased during the ice storm a week
ago. Further improvement of drought is forecast along the Virginia-West Virginia border. In the southern
Appalachians/Piedmont region, some improvement is predicted, though the heaviest rain/snow amounts are
expected to be west of the mountains. Over Florida, there is a tilt in the odds for persisting drought over
west-central and southeastern portions of the state, with expansion deemed a good bet across most of the
remainder of Florida, and extending up the southern Atlantic coast to include most of the coast of South
Carolina. The updated 30-day precipitation outlook for February 2009, issued by the Climate Prediction
Center on January 31st, calls for elevated chances of below average rainfall across the south Atlantic and
Gulf coast regions, including all of Florida. The prominent dry signal over the Southeast (as well as
the Ohio Valley wet signal) is consistent with historical La Niña cases for moderate and strong
events. With a weak La Niña currently in progress, the odds for dryness are lower than for moderate
or strong cold episodes.
Confidence for Appalachians: Moderate Confidence for Florida and southeast Georgia: Moderate to High
In Wisconsin and adjacent portions of Minnesota
and upper Michigan, the best chances for improvement are for the southern and western portions of the drought
area, which have been closer to the storm track over the Midwest in recent weeks. Areas more to the north
and east should still experience some improvement, especially with the near-term forecast of an active storm
track through the region.
Confidence for Great Lakes region: Moderate
Across the southern Plains, drought has intensified
and expanded westward in the past few weeks throughout much of the Texas Panhandle and western Oklahoma.
Drought conditions are expected to develop across far western Texas and southeast New Mexico during the next
few months. This is indicated by CPC's February 2009 and Feb-Apr 2009 rainfall forecasts, as well as 1-month,
2-month, and 3-month soil moisture forecasts from the University of Washington. Significant relief is
projected for central and eastern Oklahoma (from several storm systems) especially in the next two
weeks. Slight expansion of the Texas drought area is forecast across the upper Texas coast and into
southwest Louisiana. For southeast Colorado, the drought outlook is unclear due to conflicting
indications between various model forecasts and CPC extended-range forecasts.
Confidence for southern Plains: High in western areas; moderate in eastern areas
Confidence for southeast Colorado: Low to Moderate
The Drought Outlook for February-April 2009 calls
for an improvement in the long-term drought over southwest portions of North Dakota.
Confidence for North Dakota: Moderate
In northwest Montana, La Niña-related storminess
is expected to be offset somewhat by the climatological rain shadow just east of the Divide. Therefore, some
improvement is forecast.
Confidence for northwest Montana: Moderate
Across the widespread drought areas covering
California and the Great Basin, prospects for beneficial rain/snow are good in the near-term, but for the
three month forecast period as a whole, little mitigation in drought conditions is expected. It is thought
that the mean jet stream and associated storm track will reside mainly north of this area, though some of
this precipitation will probably reach across northwestern parts of California.
Confidence for the West: Moderate
For Hawaii, significant relief has occurred during
the past few weeks. Based on MJO phase and La Niña considerations, the Hawaiian Islands will likely experience
continued improvement in drought conditions.
Confidence for Hawaii: Moderate to High