Pictured: The NOAA/WPC 7-day rainfall amount forecast for the U.S. and timing of events annotated.
The 7-day rainfall forecast across the U.S. features short-term heavy rains across the Northeast sector of the U.S. to the east of the major U.S. crop areas. However, thunderstorms with associated locally heavy rain appear later tomorrow and last into the weekend across southern Kansas and north/east Oklahoma followed by day-after-day of thunderstorm activity across most of the soybean/corn areas of the Midwest.
Pictured: NOAA/CPC 500 MB pattern forecast for days 8-14 and dominant sensible weather features.
In the 8-14 day period the NOAA 8-14 day upper air pattern identifies prevailing important weather features across the U.S. for md-summer. The summertime ridge pattern has found a home over the northwest Great Plains drought area. Anomalous heat/dryness worsen a bad drought in Montana, the Dakotas spreading into the central Great Plains. There is concern regarding eastward expansion of the drought area into the core of the soybean/corn crop region however this scenario is unlikely due to persistent thunderstorm activity beneath upper level northwest flow. The wet zone is in the Southeast U.S. beneath a persistent upper trough. Upper westerly flow associated with the upper trough will keep tropical cyclone away from the U.S.
Pictured: The NOAA/CAS soil moisture anomaly forecast for end of July and end of September.
While agriculture markets weigh concern over expansion of northwest/west Great Plains drought eastward into the corn an soybean growing regions the more likely spread of drought conditions is farther south an into the Mid-South States for late summer/early autumn. The NOAA CAS (model) is an older/simpler forecast model but accurately predicted the North-Central U.S. drought for early summer. The diagnostic pattern required to cause this scenario to develop is an evolving upper ridge pattern across the Southeast quarter of the U.S. for late summer.
