Credit goes to Iwandesu for the calc
First Picture[]
Window Size - 9 px or 1.5 meters
Tree Size - 246 px or 41 meters
Second Picture[]
Tree - 10 px or 41 meters
Fireblast Radius - 91 px or 373.1 meters
r_thermal = Y^0.41 * constant_th
r_blast = Y^0.33 * constant_bl
5000 tons = 475 m R air blast, 100% fatalities
373.1/476 = 0.783823529
Y^0.33 = 0.783823529
Y = 0.47802364827
E = 0.47802364827 x 5000
E = 2.39011824 Kilotons of TNT
Final Tally[]
Fana torches the Witches' Forest - 2.39 Kilotons (Small Town level)