Last week's blog posting, which noted an active storm pattern building for the central United States in late January, verified well. The focus was on the development of a baroclinic zone, a clash between lower temperatures across the north and higher temperatures across the south, feeding storm systems as upper-level energy passed through the zone.
This pattern has already resulted in one strong storm this week. Heavy snowfall of 6 to almost 15 inches was recorded from northern Kansas and southern Nebraska through Iowa from Jan. 24-26. Rainfall over 1 inch was also noted for a wide swath of the country between the Ohio and Tennessee Rivers. This is just the first in a parade of storms that will affect the country during the next 10 days.
The setup remains the same. The zone of rapidly changing temperatures continues over the middle of the country. Low temperatures on the morning of Jan. 26 were minus 20 degrees Fahrenheit in North Dakota and in the middle to upper 60s Fahrenheit along the Gulf Coast. With a trough continuing to build off the West Coast and a stubborn ridge in the Southeast, this zone is not expected to change during the next 10 days. Temperatures will not be stagnant, but the overall pattern of cool in the west and northwest and warm in the Southeast is not expected to change much through this period.
With the jet stream remaining active, pieces of energy moving through the country will have a more dynamic environment to produce strong storms. This includes moderate to heavy snow across the north and moderate to heavy thunderstorms and rainfall along cold fronts. This is similar to the central U.S. storm earlier this week.
One such storm is expected to move through the West on Jan. 27 and emerge into the Plains Jan. 30. This system will be a good precipitation producer for the eastern half of the Plains and points eastward. Another will come through the pipeline a few days later next week.
This is good news on the precipitation scene. As of Jan. 19, over 63% of the contiguous U.S. was in some sort of dryness and 45% was in drought. Heavy precipitation earlier this week hit some of the drought areas in Kansas and Nebraska and in the Midwest. Some of the Intermountain West region in drought also received precipitation. A continued parade of storms will give multiple chances for drought areas in the Central and Southern Plains to bring further drought easing.
Winter wheat ratings released earlier this week showed a continued decline of from two to three percentage points in the total of good or excellent in the Central and Southern Plains. Oklahoma has fared better with recent rainfall and gained nine points in its good to excellent total to 61% good to excellent. Precipitation during this La Nina event will be very important. Soil moisture gains will have a positive effect on the wheat once it comes out of dormancy.
One area that will be adversely affected will be the Northern Plains. The entire region is rated in at least D0 (abnormal dryness) or worse. With storm systems traveling just to the south, the region will see very little precipitation and the drought will likely deepen during the next 10 days. Longer-range forecasts suggest that the region stays on the drier end of normal through February and likely March as well.
John Baranick can be reached at firstname.lastname@example.org
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