Legacy Cumulus 1 release 1.9.4 (build 1099) - 28 November 2014
(a patch is available for 1.9.4 build 1099 that extends the date range of drop-down menus to 2030)
Download the Software (Cumulus MX / Cumulus 1 and other related items) from the Wiki
Cumulus doesn't get the forecast number from the Davis console, it is only given the text of the forecast. The forecast number applies to the separate "Zambretti" forecast which Cumulus calculates itself. A value of -26 is equivalent to "Exceptional Weather, Stormy, much precipitation", so you probably have your forecast pressure extremes set incorrectly, see "http://wiki.sandaysoft.com/a/FAQ#My_for ... itation.22"