I would say there seems to be something serious going on at Unit 2 for temps and hydrogen gas to spike notably over a relatively short period of time...

http://enenews.com/hydrogen-levels-triple-reactor-2-recent-days

Hydrogen Density of Primary Containment Vessel:

• March 11 @ 0.06%
• March 16 @ 0.11%
• March 22 @ 0.18%

Title: Plant Status of Fukushima Daiichi Nuclear Power Station
Source: Tepco Press Handout
Date: March 22, 2012

and....

UPDATE: Now hydrogen levels triple at Reactor No. 2 in recent days

March 15 – 21, 2012 Reactor No. 2 Data

h/t Fukushima Diary

“If the temperature is confirmed to exceed 80 degrees, it will not meet the condition for the government’s definition of the state of a cold shutdown” -Asahi

Blue line is the ‘vessel bottom above skirt jot’:

Published: March 21st, 2012 at 8:32 pm ET