Cucurbit Downy Mildew Forecast

Weather - Continental U.S.: Active weather across the northern / central U.S. and East Coast states, plus some showers in the inter-mountain West. Increasing dryness across the South. This is due to a frontal system strung out from the central Plains eastward to the mid-Atlantic / Northeast. Wet weather is expected in these areas with showers down the East Coast, especially on Wednesday. Meanwhile, surface high pressure in the Gulf will combine with high pressure aloft over the southern Plains to produce increasingly hot and dry weather as we head to the late week period. Highs in the 80's and 90's (plus a few 100's) pushing up from the south, with 50's to 70's in the Rockies and north of the front. Lows in the 60's and 70's over a large part of the nation east of the Rockies.

OUTLOOK:

Wednesday and Thursday:

FL/GA/AL sources: Transport events are moving slowly south or southeast the next two days. Conditions during these events are unfavorable to mostly unfavorable, with spore death from solar exposure dominant. On Wednesday ... Moderate Risk to cucurbits in southeast FL. Weakly Moderate Risk for southwest, central, and northern FL. Low Risk otherwise. On Thursday ...Weakly Moderate Risk for central and southern FL. Low Risk otherwise.

NC/SC sources: Attention is on the events from the NC sources, during which conditions are favorable as airborne spores head to the north and northeast on Wednesday and northeast and east on Thursday. Wednesday ... HIGH Risk for cucurbits in central and eastern NC. Moderate Risk for eastern WV, central VA, and central PA. Weakly Moderate Risk for cucurbits in DE, MD, eastern PA, NJ, Long Island, and southeast NY. Low Risk otherwise. Thursday ... Moderate Risk for cucurbits in eastern NC and southeast VA. Strongly Moderate Risk for eastern MD, DE, southeast NJ. Weakly Moderate Risk for Long Island and southern New England. Low Risk otherwise. For the SC source, expect Weakly Moderate Risk to cucurbits from southern SC to the central SC coast each day.

TX, LA, and CA sources: Transport events move slowly east out of southern LA, northwest and north out of southern TX, and slowly southeast from coastal CA. All of these events are associated with unfavorable conditions for survivable transport and deposition each day, and the heat continues to build in TX and LA. Low Risk to cucurbits each day from the events out of TX, LA, and CA.

Forecast details for the known sources are provided below.

TK

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Current Sources / source regions:

• Southern FL
• Central FL
• Northern FL / southern GA
• FL panhandle / southeastern AL
• Monte Alto, TX
• Louisburg, NC
• Clarendon, NC
• Charleston, SC
• Abbeville, LA
• Watsonville, CA