Narrative:

We were on final for ILS [runway] 19C at 3;000 feet and cleared the approach. The weather was moderate rain at night in IMC. The first officer was flying. The radar showed green and yellow precipitation ahead and we were in sequence following other aircraft on the approach. The aircraft was gear down and flaps 3 as we were intercepting the glide path in light turbulence with autopilot on. As we approached the glideslope intercept point; a huge radar echo appeared in front of our flightpath and ATC cancelled our approach clearance and told us to maintain 3;000 feet. At this point we encountered severe turbulence and heavy rain and had a very difficult time controlling the aircraft through the autopilot. As the first officer cleaned the aircraft configuration up; we encountered a severe downdraft and lost about 500 feet. I commanded the first officer to turn the autopilot off and recover the altitude. I requested a climb from ATC and a turn. The radios were very congested and hard to understand and ATC denied our request. We exited the heavy rain and turned north to hold at martinsburg VOR. In holding we decided to try another approach after the storm front passed and came up with a bingo fuel for our alternate. We headed for another approach to 19C at iad; but the weather had not improved enough for another approach so we diverted. When we got to [our alternate]; I contacted the dispatcher and was told that iad airport had been shut down for weather while we were on the first approach but iad never informed the airlines.

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Original NASA ASRS Text

Title: A320 Captain reported deviating to an alternate after encountering heavy rain and severe turbulence on approach to IAD.

Narrative: We were on final for ILS [Runway] 19C at 3;000 feet and cleared the approach. The weather was moderate rain at night in IMC. The FO was flying. The radar showed green and yellow precipitation ahead and we were in sequence following other aircraft on the approach. The aircraft was gear down and flaps 3 as we were intercepting the glide path in light turbulence with autopilot on. As we approached the glideslope intercept point; a huge radar echo appeared in front of our flightpath and ATC cancelled our approach clearance and told us to maintain 3;000 feet. At this point we encountered severe turbulence and heavy rain and had a very difficult time controlling the aircraft through the autopilot. As the FO cleaned the aircraft configuration up; we encountered a severe downdraft and lost about 500 feet. I commanded the FO to turn the autopilot off and recover the altitude. I requested a climb from ATC and a turn. The radios were very congested and hard to understand and ATC denied our request. We exited the heavy rain and turned north to hold at Martinsburg VOR. In holding we decided to try another approach after the storm front passed and came up with a bingo fuel for our alternate. We headed for another approach to 19C at IAD; but the weather had not improved enough for another approach so we diverted. When we got to [our alternate]; I contacted the dispatcher and was told that IAD airport had been shut down for weather while we were on the first approach but IAD never informed the airlines.

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.