XING ALT UNDERSHOOT DURING DSCNT.

Narrative

THE CAPT WAS FLYING THE ACFT ON THE MOXEE 3 ARR; INTO PORTLAND ARPT. WE WERE TOLD TO SLOW DOWN TO 250 KTS FOR SPACING. PORTLAND WAS LNDG RWY 20 FOR HIGH WINDS. WE HAD A 100 KT TAILWIND AND WERE IMC WITH MODERATE RIME ICE. PASSING THROUGH ABOUT FL240 WE WERE TOLD TO DSND TO 10000 FT MAINTAIN 250 KTS BY 'WYLEE' INTXN. BECAUSE OF THE ICING; WE HAD TO KEEP OUR PWR UP SO THE ACFT WOULD HAVE ADEQUATE DEICING CAPABILITY. HAVING SLOWED TO 250 KTS FOR SPACING; OUR VERT SPD WAS DIMINISHED. THE CAPT WAS NOT TAKING INTO ACCOUNT THE 100 KTS OF TAILWIND. BOTH THE CAPT AND I MISREAD THE DSCNT PROFILE. WE THOUGHT 'WYLEE' INTXN WAS AT 30 MI; BUT IT WAS AT 40 MI. THE CAPT WAS USING FULL SPOILERS; BUT WE ACTUALLY PASSED 'WYLEE' AT ABOUT 13000 FT AND 250 KTS. WE WERE ABOUT 3000 FT TOO HIGH. AT THIS POINT; I RPTED TO ATC; THAT WE WOULD NOT BE ABLE TO MAKE OUR ALT RESTR OVER 'WYLEE;' AND THEY SAID IT WAS NO PROB. CORRECTIVE ACTIONS: BOTH THE CAPT AND I WERE TASK SATURATED DUE TO THE WX CONDITIONS; AND SETTING UP FOR AN UNUSUAL APCH INTO PORTLAND ARPT. WE DID NOT TAKE INTO ACCOUNT THE HIGH TAILWINDS OR THE HIGHER PWR SETTINGS FOR THE DEICING. WE ALSO MISREAD THE STAR CHART; AND WE FIGURED ON THE WRONG DSCNT PROFILE. WE BOTH SHOULD HAVE CONCENTRATED WITH THE TASK OF FLYING THE ACFT AND NOT WORRIED ABOUT THE UNUSUAL APCH AHEAD.