Latest Seasonal Assessment -
The Southeastern drought region should continue to see improvement, with the best odds for relief extending across the northern
part of the drought area as well as along the coast. One storm system brought widespread relief during March 3-4, while another
storm system will bring another shot of rain on March 7-9. More limited improvement is expected over the longer run in the
southern parts of the drought region due to seasonal forecasts of drier weather by April. Drought will improve on the
northwestern peninsula of Florida, but persist and expand across southern Florida. Farther west, drought is forecast to
persist over central Texas and in the western Oklahoma Panhandle region, with the odds still favoring expansion into west
Texas and eastern New Mexico. Forecasts for drier weather have led to the Outlook showing persisting drought over southern
California and southern Nevada, although deep mountain snow pack will boost water supplies this spring. To the north, improvement
is anticipated over the northern Great Basin, while more limited improvement is forecast for the northern High Plains. Little
change is expected over the far western Dakotas, but the odds for improvement increase to the east into Minnesota.
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Tools used in the Drought Outlook included the
official CPC long-lead precipitation outlook for March – May 2008, the for March, the four-month drought termination and
amelioration probabilities, 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 moisture, the CFS seasonal
precipitation and soil moisture forecasts, and La Niña.
The changes from the February 21 drought outlook are generally
minor. Increased improvement is shown for the Southeast drought region due largely to short-term rainfall forecasts, with
1-2 inches of rain likely from Virginia southward into the Carolinas and Georgia on March 7-9. The area of improvement now
extends along the coast of Virginia and the Carolinas. Besides the near-term relief, the latest GFS model runs indicate
additional storm systems around the middle of March. In contrast, long-range forecasts and models continue to point to the
possibility of drier weather returning to the region during April and May. Splitting the differences between the long-range
and short-range forecasts results in more limited improvement from central Alabama into south-central North Carolina. This
is the area more likely to see dry weather later this season if the long-range forecasts pan out. La Niña is forecast to
continue through spring, consistent with some drier weather returning to the Southeast. However, it should be noted that the
long range models and La Niña composites have been too dry for much of the Southeast in recent months, so confidence is
relatively low that the dry pattern will return. Recent wet conditions and short-term forecasts of more rain removed the area
of drought development from northern Florida and led to the forecast for improvement for the northwest peninsula. Continuing
to show development in southern Florida is consistent with the ongoing La Niña and CFS model soil moisture forecasts.
Elsewhere, east Texas has seen some recent rain, and short-range
forecasts point to more moisture during the early part of the forecast period. As a result, the slim area of development
shown last month east of the ongoing drought region has been removed. The drought is still expected to persist in central
Texas and expand into eastern and southern New Mexico, as seasonal forecasts are consistent in showing dryness in this
region. The eastern part of the drought region may see some good rains during March, but longer-range dryness should offset
short-term relief. The development area was pulled back from southwest Nebraska and northwest Kansas due to lack of dryness
in the medium range and CPC updated monthly forecasts. The monthly forecast shows the best odds for below-normal rainfall
extending from southern and western Texas into southern California. The consistency of short, medium, and long-range
forecasts showing below-normal precipitation led to expansion northward of the persisting drought area in interior southern
California. However, well above-normal mountain snow pack will lead to water supply boosts this spring. Relief is still
expected in the northern Great Basin. The CFS soil moisture model shows improvement from northern Utah into Idaho and
Oregon by the end of May, and the updated monthly forecast shows above-normal precipitation from western Montana westward.
The odds for improvement diminish to the east into the Northern Plains. The persisting area in the western Dakotas grew
smaller in this forecast due to more favorable medium-range forecasts. From the eastern Dakotas into Minnesota, medium-range
forecasts, March, April, and May long-range model forecasts, and La Niña composites are consistent in showing a tendency
toward above-normal precipitation this season, so improvement is depicted for the small areas of drought in southeastern
North Dakota and western Minnesota.
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