The first clue will be here hopefully next week and then I'll post a new clue every 1 - 2 weeks and the coal is to get this shawl finished by March 20, therefore the name Vernal Equinox Shawl Surprise. Altogether there will be 5 - 6 clues.
But now it's time to knit a swatch and decide what yarn to use. Fingering, light fingering or lace weight yarn (100 grams = 430 - 660 yards / 400 - 600 meters) is ok for this shawl. The thicker yarn and/or needles the larger your shawl will be. I used 100 % wool yarn (tex 37 x 6, 100 gram = about 450 meters / 492 yards) for designing and test knitting this shawl and my blocked swatch gauge is 15 stitches and 24 rows per 10 cm / 4 inches with US 7 (4.5 mm) needles. Having this gauge you'll hopefully end up with a 77 cm from neck down and about 194 - 196 cm wide shawl, blocked measurements. There will be 220 rows, but you can't calculate the height of your shawl straight from your gauge, cause there will be different lace patterns and they all have their own gauge.
You will need about 900 yards of yarn, but be prepared that you may need more yarn, especially if you choose to knit in plain some clues instead of lace patterns. There is also a possibility to cast off by crocheting or by knitting and the knitted version takes more yarn.
Links to files:
swatch chart and chart key (pdf)
swatch only (gif)
KAL buttons and banners in different sizes to take with you for your blog.
I'm going to start an another version of this shawl using linen-cotton blending (tex 76 x 2, 100 grams = 710 yards / 650 meters). Haven't knit a swatch yet.
EDIT: Vernal Equinox Shawl Surprise group on Ravelry and Vernal Equinox Shawl Surprise pattern information on Ravelry, so you can link your projects.