Can't get gnuplot to fill below line -

i'm trying gnuplot 5.0 under os x 10.10.3 fill blue below lower series in plot. i've tried lots of variations line datafileforecast using 1:4 filledcurves above y1=0 linestyle 3, nothing seems work.

here's source:

#!/opt/local/bin/gnuplot reset  set terminal pngcairo enhanced background "#000000" font "lato-light,20" linewidth 1 rounded size 2048,670 set output "10dayforecast.png" datafileforecast = "10dayforecast.csv" set datafile separator ',' set timefmt "%y-%m-%d" stats datafileforecast using 2:4 nooutput  freezewarning = 32. yhigh = stats_max_x + 10. ylow = stats_min_y - 10.  unset key set border linetype rgb "#666666" set boxwidth 0.25 relative set style fill transparent solid 0.4 set style line 1 linetype rgb "#0066cc" # freeze line set style line 2 linetype rgb "#ffffff" pointtype 7 pointsize .5 # points both high , low temp set style line 3 linetype rgb "#000077" # fill low temp set style line 4 linetype rgb "#ffff00" # rain forecast set style line 5 linetype rgb "#770000" # fill high temp set style line 6 linetype rgb "#ff7777" # line high temp set style line 7 linetype rgb "#3377ff" # line low temp  set label "°" right  unset mxtics set tics textcolor rgb "#666666"  # x axis set xdata time  set xtics format "%a" nomirror set autoscale xfix set offsets 12*60*60,12*60*60,0,0  # y axis set yrange [ylow:yhigh] unset ytics if (32 > ylow) set ytics 32,1,32 tc rgb "#ffffff" font ",18" set ytics format "%2.0f°" nomirror  # y2 axis set y2tics format "%2.0f%%" textcolor "#ffff00" nomirror set y2range [0:100]  plot datafileforecast using 1:6 impulses linestyle 4 axes x1y2,\     datafileforecast using 1:2:4 filledcurves above linestyle 5,\     datafileforecast using 1:2 lines linestyle 6,\     datafileforecast using 1:2 points linestyle 2,\     datafileforecast using 1:2:3 labels offset 1.75,0.5 textcolor "#ffffff" font ",18",\     datafileforecast using 1:4 filledcurves above y1=0 linestyle 3,\     datafileforecast using 1:4 lines linestyle 7,\     datafileforecast using 1:4 points linestyle 2,\     datafileforecast using 1:4:5 labels offset 1.75,0.5 textcolor "#ffffff" font ",18",\     freezewarning filledcurve above y1=0 linestyle 1 

and here's data file:

2015-06-29,94,94°,69,69°,20.0 2015-06-30,99,99°,72,72°,0.0 2015-07-01,102,102°,73,73°,0.0 2015-07-02,96,96°,69,69°,0.0 2015-07-03,94,94°,68,68°,10.0 2015-07-04,92,92°,67,67°,0.0 2015-07-05,91,91°,63,63°,0.0 2015-07-06,91,91°,62,62°,0.0 2015-07-07,91,91°,61,61°,0.0 2015-07-08,91,91°,63,63°,0.0 

what missing?

i'm not sure, why doesn't work. bug. workaround can give third column in using statement indicate lower boundary of filled area:

plot ...,\     datafileforecast using 1:4:(0) filledcurves linestyle 3 

this gives output

the freezewarning area plotted correctly, if yrange includes region.