Narrative:

Aircraft had deferred pack 1. During climbout; noticed cabin altitude climbing. A short time later; received a pack 2 vlv clsd EICAS message. During consultation of the QRH; received a bld vlv 2 clsd message. Altitude at the time was approximately 16;000 feet. While coordinating with ATC to secure a lower altitude; sending a message to dispatch; and complying with QRH procedures; aircraft entered precipitation; generating an ice cond - I/a inoperative warning message. Opted to advise ATC and received vectors clear of precipitation. QRH procedure did not correct the problem generating the warning message; however upon clearing the precipitation; the warning message disappeared. No ice accretion was noted on the aircraft. During this time period; aircraft was descending to 6;000 feet; then to 4;000 feet; with a tat of +5; while returning to ZZZ. Aircraft reentered small pockets of precipitation; generating the ice cond - I/a inoperative a couple more times; disappearing each time the aircraft cleared the precipitation. Due to the deteriorating weather conditions in ZZZ; elected to perform an overweight landing. Airport was in sight 10+ miles away; with no precipitation between aircraft and the airport. Another check of the aircraft revealed no ice accretion. Landed approximately 4;500 lbs. Overweight. Smooth and soft touchdown with descent rate at or less than 200 FPM. Landing and taxi in uneventful. Brake temperatures remained in the green range during taxi and parking at the gate.

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Original NASA ASRS Text

Title: EMB-145 Captain reported a loss of pressurization; resulting in a diversion.

Narrative: Aircraft had deferred Pack 1. During climbout; noticed cabin altitude climbing. A short time later; received a Pack 2 VLV CLSD EICAS message. During consultation of the QRH; received a BLD VLV 2 CLSD message. Altitude at the time was approximately 16;000 feet. While coordinating with ATC to secure a lower altitude; sending a message to dispatch; and complying with QRH procedures; aircraft entered precipitation; generating an ICE COND - I/A INOP warning message. Opted to advise ATC and received vectors clear of precipitation. QRH procedure did not correct the problem generating the warning message; however upon clearing the precipitation; the warning message disappeared. No ice accretion was noted on the aircraft. During this time period; aircraft was descending to 6;000 feet; then to 4;000 feet; with a TAT of +5; while returning to ZZZ. Aircraft reentered small pockets of precipitation; generating the ICE COND - I/A INOP a couple more times; disappearing each time the aircraft cleared the precipitation. Due to the deteriorating weather conditions in ZZZ; elected to perform an overweight landing. Airport was in sight 10+ miles away; with no precipitation between aircraft and the airport. Another check of the aircraft revealed no ice accretion. Landed approximately 4;500 lbs. overweight. Smooth and soft touchdown with descent rate at or less than 200 FPM. Landing and taxi in uneventful. Brake temperatures remained in the green range during taxi and parking at the gate.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.