Finished measurement: 
Snowman: 11.5-inches tall including the hat, the body at the largest part after stuffing is about 17-inches in circumference.
Scarf: About 48-inches long when slightly stretched.

Yarn
Wisconsin Woolen Spun Sport by Barrett Wool Co. (100% American Wool), 50 grams / 180 yards, in Birch (creamy white), and Jam (red). 

Woolens by Barrett Wool Co. (100% American Wool), 50 grams per skein, in the following colorways: Loam (heathered dark grey and brown mix), and Vine (heathered green).

Special Fluffy Mohair/silk skein: 50 grams in white to hold together with the Birch colorway of Wisconsin Woolen Spun for the snowman. 

Amounts of yarn used in grams:

Snowman (sport + fluffy skein): 
Fluffy skein: About 43 grams used
Sport yarn: About 30 grams used

Hat, Arms and Buttons:
About 8 grams of Loam used in total.
The finished hat alone used 5.4 grams. 
The arms and buttons alone used 2.3 grams.

Scarf:
About 14 grams of various colorways in the sport weight.

Needles
Snowman and Hat: US size 4 / 3.5mm set of double-pointed needles and 16-inch circular
Arms: US size 5 / 3.75mm set of double-pointed needles
Scarf: US size 6 / 4.00mm set of double-pointed needles.

Or size to obtain gauge.

Gauge
US size 4 / 3.5mm for the Snowman (two strands held together, sport + fluffy skein): 5 sts per inch in stockinette stitch

US size 4 / 3.5mm for the Hat (one strand of sport weight): 6.5 stitches per inch in stockinette stitch

US size 5 / 3.75mm for the Arms (one strand of sport weight): 6 sts per inch in stockinette stitch

US size 6 / 4.00mm for the Scarf (one strand of sport weight): 5.5 sts per inch in stockinette stitch

Materials
-Locking stitch markers
-Yarn needle
-Sewing needle and thread (either orange or white) for the carrot felt nose 
-3-inch square of wool felt in orange for the carrot nose
-Polyester fiber-fill
Optional: Poly-pellets to add weight to the bottom of the Snowman (Considered a choking hazard for infants and young children. Leave out if concerned.)
-One pair of 6mm safety eyes (Considered a choking hazard for infants and young children. If concerned, embroider French knots instead).
-Black embroidery floss or black crochet cotton thread for the smile