Like the Chicago River turning a slightly brighter shade of green on this day than it does on most others, count on Murphy's Bar & Grill's annual St. Patrick's Day Block Party to lure thousands of corned beef, cabbage, and Guinness and Harp lovers to the corner of Nu'uanu Avenue and Merchant Street today.

About 3,000 are expected for proprietor Don Murphy's 20th annual downtown shindig. Murphy's will open at 11 a.m. serving up corned beef and cabbage and Gaelic steak sandwiches. Irish stew, fish 'n' chips and steamed clams, oyster shooters and fresh oysters from Murphy's self-proclaimed "longest oyster bar in the Pacific" will be served in the municipal parking lot across the restaurant from noon. (Murphy and crew were about to begin shucking 3,000 oysters when I called Thursday.)

Also in the lot, a keiki fair will offer Irish storytelling, a make-your-own-crafts booth, face-painting and other activities from noon to 3 p.m.

From 5 to 10 p.m., Nu'uanu Avenue between King Street and Nimitz Highway, and Merchant Street between Nu'uanu Avenue and Bethel street, shuts down for the block party. On tap then, more food booths from Side Street Inn and Compadres, libation booths, a live-music stage and DJs.

For each pound of corned beef sold, Murphy is once again donating $1 to the Hawai'i Children's Cancer Foundation, which got $2,500 last year.

Area parking lots (at Marin Tower, Harbor Court, etc.) will be open. Feeling a greener shade of emerald, post-party? Hail taxis queued at the makai end of Nu'uanu Avenue.

Across Nimitz Highway, Aloha Tower Marketplace goes green from 4 to 10 p.m. with live Irish and Celtic music, strolling leprechauns (with beads!) and lots of food and drink specials at participating restaurants.

Erin go bragh!

Reach Derek Paiva at dpaiva@honoluluadvertiser.com.