Epi Week #38 - 2014 General Statements

Both general mosquito activity and arbovirus activity remained low this week. Cool evening temperatures have prevailed, keeping surveying activities down to a minimum and making ULV spraying unfeasible. For comparison, Epi Week 38 mosquito pool submissions are down 17% from 2013 and 25% from 2012. WNV positive pools are down 83% from 2013 while EEEv positive pools are down 50%.

Weather

Epi Week 38 featured temperatures that were well below average, with some areas receiving their first significant frost/freeze on September 19th. Norwood (Norfolk County), for example, had an overnight low of 28’F that night, with other municipalities experiencing overnight lows in the lower 30s. There was little precipitation across the state, with most areas picking up less than a tenth of an inch of rain.

Epi Week 39 is expected to be a bit warmer than Epi Week 38, with the possibility of a little more precipitation (early estimate = average of 0.35 to 0.75” for the period). For Epi Week 40, models are starting to signal the development of a large east coast ridge, which would provide us with an extended period of well above normal temperatures. This same pattern will keep us drier than normal until at least the beginning of the second week of October.

No precipitation map was available this week.