Outside the window you can see an area of dirt that appears muddy from the rain.
Its still raining out
You cannot infer an exact tense for the verb. When something is muddy it could be from it raining right then, or when it did rain in the past.
exists e1 p1 x1 x5.(n_window(x1) & n_rain(x5) & n_person(x1) & outside(e1,x1) & exists e3 e2 p2 x2 x3 x4.(Theme(e3,x2) & Actor(e3,x1) & v_see(e3) & exists s1.(from(s1,x5) & Theme(s1,x4) & a_muddy(s1)) & Topic(e2,p2) & Actor(e2,x4) & v_appear(e2) & (x2 = x4) & of(x2,x3) & n_dirt(x3) & n_area(x2)) & Topic(e1,p1) & Actor(e1,x1) & v_can(e1))
exists e1 s1 s2 x1.(a_still(s2) & Manner(e1,s2) & a_out(s1) & Manner(e1,s1) & Actor(e1,x1) & v_rain(e1) & n_its(x1))