FORECAST DISCUSSION: Wednesday, June 5. High pressure in the east is providing a lull in the action as one front moves off the coast and a low pressure system gathers itself in the Plains. Unfortunately, this next system has a wide north-to-south range and is forecast to move SLOWLY eastward during the latter part of this week. This means that conditions favorable for disease development will persist for several days in many areas, beginning sometime Thursday in the Ohio Valley and later elsewhere. Almost all risks are low today, though, as abundant sunshine during the early transport hours is killing lots of spores.
*** New source site at Hortense, GA *** Blue mold was identified in northern Brantley County, GA during the weekend. Active sporulation is occurring. If your fields are in a triangular-shaped area formed by connecting the cities of Jacksonville, FL, Savannah, GA, and Hortense, and you received any rain Tuesday or Wednesday, then you may have had live spores deposited. The threat from this source will extend into the Carolinas Friday or Saturday as winds in advance of the approaching cold front turn to the south and southwest.
*** Kentucky sources High Risk for Thursday - Canadian growers take note! *** The risk associated with today's release is low. Conditions will become favorable tomorrow for disease development to areas northeast of the Kentucky source sites, including any production areas in Ohio....western WV, PA, and NY.....and extreme southern Canada north of Lakes Erie and Ontario. Much will depend on the timing of the cloud cover and showers as the next storm system nears. Trajectories and weather for Thursday morning's release are the ones presented in the outlooks. On Tuesday, growers in S Ohio and NW WV were at moderate risk of blue mold development. At least a few of the spores from the Cythiana region survived and were likely brought down by some early afternoon showers in S Ohio, or perhaps later Tuesday evening S of the WV panhandle.
*** Other source areas are low risk today and Thursday *** Trajectories out of S Texas are to the north; those from Cuba move SW or W. Spores from both places are unlikely to survive since transport is under sunny skies. The N FL disease locations are rated low risk today and tomorrow also, with one possible exception. Scattered cloudiness developed around midday in the coastal regions of N FL, GA, and SC, and isolated showers may have occurred. The clouds probably provided enough shielding from the sun for some spores to survive the afternoon. If you are near the forecast track for the N FL or Hortense, GA sources and you had some shower activity Wednesday, chances are you got some spores. Transport conditions for Thursday should be unfavorable for spore survival. However, the weekend forecast for the SE U.S. sources looks pretty ugly from Wednesday's vantage point. TK
HIGH-RISK SOURCES: Kentucky sources THURSDAY
Web page last updated by Thomas Keever on 5 June 1996.