Multiple 'layer' parameters can be sent by simply putting a comma between them: 'layer=meta,high' or 'layer=low,high'. This results in all of the segments requested being returned in the same line, so you would first split them by a tilde. The first element of each segment is the layer_code, so inspecting the first four characters will tell you which segment you're working with. Splitting each of these segments by an asterisk will get each of the elements. The values for the 'lat' and 'lon' parameters can be found here: http://developer.mapquest.com/web/tools/lat-long-finder.
NOTE: the order in which the layer strings occur does not affect the output order. 'layer=meta,high' will have the same result as 'layer=high,meta'. The output order is always: Header, Meta, Low Verbosity, High Verbosity, Hazard
hd*ParfaitAPI*http://api.parfait.snarkybox.com/*forecast*33.94*-118.4*4***head,meta,low,high*20160309*0141*2601:140:8202:cd8f:58f4:351e:5d28:5681*2016.03.09.18~|mt*Los Angeles International Airport, CA*33.94*-118.39*98**2016-03-08T21:04:07-08:00*4*PT1H*Los Angeles/Oxnard, CA*http://www.wrh.noaa.gov/lox*markMitchell~|lo*00*Tonight*http://forecast.weather.gov/newimages/medium/nfew.png*Mostly Clear*52*Minimum*Fahrenheit*0~lo*01*Wednesday*http://forecast.weather.gov/newimages/medium/few.png*Sunny*69*Maximum*Fahrenheit*0~lo*02*Wednesday Night*http://forecast.weather.gov/newimages/medium/nfew.png*Mostly Clear*56*Minimum*Fahrenheit*0~lo*03*Thursday*http://forecast.weather.gov/newimages/medium/sct.png*Mostly Sunny*68*Maximum*Fahrenheit*0~|hi*00*2016-03-08T22:00:00-08:00*Mostly clear, with a low around 52. North wind 5 to 10 mph, with gusts as high as 15 mph.~hi*01*2016-03-09T06:00:00-08:00*Sunny, with a high near 69. East northeast wind 5 to 10 mph becoming west in the morning. Winds could gust as high as 15 mph.~hi*02*2016-03-09T18:00:00-08:00*Mostly clear, with a low around 56. Calm wind becoming east around 5 mph.~hi*03*2016-03-10T06:00:00-08:00*Mostly sunny, with a high near 68. East wind 5 to 15 mph becoming west in the morning. Winds could gust as high as 20 mph.~|