North Carolina State University
Cucurbit Downy Mildew Forecast
*** Epidemic Update - 4 July: First report of CDM in Michigan in 2008. A light, very recent infection was discovered earlier this week in a field in Monroe County. Also, we have updates on the sentinel plots in FL. Please see the Epidemic History page for details. Forecast locations have been rearranged to account for the current status of the epidemic. ***
*** Epidemic Update - 1 July: New reports from eastern SC - commercial field in Williamsburg County and sentinel plot in Sumter County. Please see the Epidemic History page for details. ***
Forecast Summary: Friday, July 4, 2008
Weather - Central & Eastern U.S. / southern Canada: Showery weather for the southern and eastern United States through the weekend and into next week. A classic summertime pattern is set up for the holiday weekend ... the Bermuda High is centered off the coast and a wavy frontal boundary stretches from the Northeast through the Ohio Valley and into the Midwest. The upper-level pattern is also favorable for guiding moisture into the southern and eastern U.S. Rainfall will be focused near the front and along the Gulf Coast on Friday, with dry weather to isolated showers elsewhere. The front will sag into the eastern Ohio / TN Valley over the weekend, shifting the emphasis over the southern and eastern U.S. Expect partly to mostly cloudy skies and daily rounds of scattered to numerous showers and storms across the South and East. Some heavy rain possible southern TX. Much of the Plains and Great Lakes regions will be dry, though a cold front may impact the northern Plains late in the period. Highs in the 70's north to 80's and 90's south and Plains. Lows in the 50's north to 60's and 70's south.
OUTLOOK
Friday through Sunday - Significant potential for transport and deposition along the Atlantic Seaboard with similar transport events for the next 3 days.
Southeast sources: Transport events are moving to the northeast each day. Conditions on Friday will be mixed, with favorable conditions expected Saturday and Sunday. Cucurbits in the Southeast and mid-Atlantic states (northern FL, southern and eastern GA, central and eastern sections of the Carolinas, central and eastern VA, DE, MD, eastern PA, and NJ) will be at Moderate Risk on Friday, Strongly Moderate to HIGH Risk Saturday and Sunday. Cucurbits in southeast NY, Long Island, and southern New England will be at Weakly Moderate Risk for Friday's events, Moderate Risk for Saturday's and Sunday's events. Risk here is lower due to upwind deposition. Low risk otherwise.
Texas / Louisiana: Transport events curve to the north and east with similar conditions expected for each day's events. Friday through Sunday: Moderate Risk for cucurbits in southeast TX and central and northern LA. Weakly Moderate Risk for southeast OK, AR, western and northern MS, and southwestern TN. Low Risk otherwise.
Southeast MI / southern Canada: Transport events from this region move southwest on Friday, west and north on Saturday, northeast on Sunday. Unfavorable conditions for survivable transport and deposition are expected for each day's events. Low Risk to cucurbits in this region Friday through Sunday.
Forecast details for the known sources are provided below.
TK