Narrative:

En route from our departing city; there had been several turbulence reports for the southern california area. The latest one was from FL270 down to 12000 ft; code 4 turbulence. Before starting our descent into ZZZ; my first officer and I discussed the turbulence reports. We also discussed having the flight attendants taking their seats early. He called the flight attendants and informed them what was ahead and to start cleaning up and we would ring them soon. Passing through FL320 I signaled the cabin to secure the cabin for arrival. The flight attendants were seated by FL290. During the arrival; ATC issued a severe turbulence report from another carrier 40 KM east of ZZZ. This report was 10 mins old. When the first officer was finally able to get a word in with the controller; he told them that we were not able to go through that area. The controller was very slow to respond and the first officer again informed him that we could not go there. After a short while the controller came back and said that in his opinion the area had moved off the arrival and there had been several aircraft pass through there with nothing more than moderate turbulence. The first officer attempted to contact dispatch; at first unsuccessfully. Contact was finally made several mins later and we informed them of the severe turbulence reported by the other carrier. The dispatcher replied that yes they had gotten it several mins earlier; but several aircraft had gone through since; with only moderate turbulence being reported. We were cleared to descend via the arrival and then for the approach to runway 24R. I had slowed down to 250 KTS when we entered continuous moderate turbulence; so I slowed to 230 KTS. At approximately 10500 ft in partial IMC the aircraft kicked around abruptly with a couple hundred ft deviation and a 40 KT airspeed loss. This lasted for approximately 10 seconds; and we broke out into the clear again. The tops were no higher than 13000 ft on any of the cells and the bases were approximately 3000 ft in that area. In less than 2-3 mins we entered a second windshear encounter at 7000 ft; and the aircraft kicked around. As I was applying emergency thrust; the first officer was calling airspeed and was following through with his hands on the thrust levers (ouch!). After the power was applied and the nose pushed over; the aircraft started to roll and I had to use full inputs. It did not stop the roll at first. The aircraft rolled 50 degrees before the roll stopped. After we had the aircraft under control; the first officer asked if I wanted to declare an emergency and I said yes. First officer then told ATC that we were declaring an emergency and needed to get out of that area! We were then vectored south and a very short time later we broke out onto the clear with ZZZ in sight. We were approximately 25 mi from the airport at this point. We asked then to be vectored back to ZZZ for an approach. The controller then changed our runway 4 times and asked us to slow to 170 KTS. We declined the speed telling him that we were unable; but accepted the final runway. The controller asked if we were going to terminate the emergency at this point; and we said yes. Because safety and controling the aircraft was our #1 concern; we literally did not have time to converse with the flight attendants; as we were only 15 KM to the airport. We did though as soon as we got on the ground. They reported to us that everyone was ok. While we taxied in; we called for maintenance to meet us at the gate. I got out of the cockpit as soon as I could to be available for passenger if need be. Some passenger had already deplaned. All passenger seemed fine and some thanked us. No negative comments were said or heard. I did ask the flight attendants if they were ok; as well as the passenger; and they said yes they were all fine. Maintenance then showed up and I briefed them and they performed an inspection. I then called dispatch and told them of the severe turbulence; and that we had also declared an emergency. I later found out that the aircraft was fine.

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Original NASA ASRS Text

Title: B737-300 ENCOUNTERS SEVERE TURBULENCE ON DESCENT. HAD BEEN ADVISED THAT PREVIOUS REPORT OF SEVERE HAD BEEN SUPERSEDED BY REPORTS OF ONLY MODERATE.

Narrative: ENRTE FROM OUR DEPARTING CITY; THERE HAD BEEN SEVERAL TURB RPTS FOR THE SOUTHERN CALIFORNIA AREA. THE LATEST ONE WAS FROM FL270 DOWN TO 12000 FT; CODE 4 TURB. BEFORE STARTING OUR DSCNT INTO ZZZ; MY FO AND I DISCUSSED THE TURB RPTS. WE ALSO DISCUSSED HAVING THE FLT ATTENDANTS TAKING THEIR SEATS EARLY. HE CALLED THE FLT ATTENDANTS AND INFORMED THEM WHAT WAS AHEAD AND TO START CLEANING UP AND WE WOULD RING THEM SOON. PASSING THROUGH FL320 I SIGNALED THE CABIN TO SECURE THE CABIN FOR ARR. THE FLT ATTENDANTS WERE SEATED BY FL290. DURING THE ARR; ATC ISSUED A SEVERE TURB RPT FROM ANOTHER CARRIER 40 KM E OF ZZZ. THIS RPT WAS 10 MINS OLD. WHEN THE FO WAS FINALLY ABLE TO GET A WORD IN WITH THE CTLR; HE TOLD THEM THAT WE WERE NOT ABLE TO GO THROUGH THAT AREA. THE CTLR WAS VERY SLOW TO RESPOND AND THE FO AGAIN INFORMED HIM THAT WE COULD NOT GO THERE. AFTER A SHORT WHILE THE CTLR CAME BACK AND SAID THAT IN HIS OPINION THE AREA HAD MOVED OFF THE ARR AND THERE HAD BEEN SEVERAL ACFT PASS THROUGH THERE WITH NOTHING MORE THAN MODERATE TURB. THE FO ATTEMPTED TO CONTACT DISPATCH; AT FIRST UNSUCCESSFULLY. CONTACT WAS FINALLY MADE SEVERAL MINS LATER AND WE INFORMED THEM OF THE SEVERE TURB RPTED BY THE OTHER CARRIER. THE DISPATCHER REPLIED THAT YES THEY HAD GOTTEN IT SEVERAL MINS EARLIER; BUT SEVERAL ACFT HAD GONE THROUGH SINCE; WITH ONLY MODERATE TURB BEING RPTED. WE WERE CLRED TO DSND VIA THE ARR AND THEN FOR THE APCH TO RWY 24R. I HAD SLOWED DOWN TO 250 KTS WHEN WE ENTERED CONTINUOUS MODERATE TURB; SO I SLOWED TO 230 KTS. AT APPROX 10500 FT IN PARTIAL IMC THE ACFT KICKED AROUND ABRUPTLY WITH A COUPLE HUNDRED FT DEV AND A 40 KT AIRSPD LOSS. THIS LASTED FOR APPROX 10 SECONDS; AND WE BROKE OUT INTO THE CLR AGAIN. THE TOPS WERE NO HIGHER THAN 13000 FT ON ANY OF THE CELLS AND THE BASES WERE APPROX 3000 FT IN THAT AREA. IN LESS THAN 2-3 MINS WE ENTERED A SECOND WINDSHEAR ENCOUNTER AT 7000 FT; AND THE ACFT KICKED AROUND. AS I WAS APPLYING EMER THRUST; THE FO WAS CALLING AIRSPD AND WAS FOLLOWING THROUGH WITH HIS HANDS ON THE THRUST LEVERS (OUCH!). AFTER THE PWR WAS APPLIED AND THE NOSE PUSHED OVER; THE ACFT STARTED TO ROLL AND I HAD TO USE FULL INPUTS. IT DID NOT STOP THE ROLL AT FIRST. THE ACFT ROLLED 50 DEGS BEFORE THE ROLL STOPPED. AFTER WE HAD THE ACFT UNDER CTL; THE FO ASKED IF I WANTED TO DECLARE AN EMER AND I SAID YES. FO THEN TOLD ATC THAT WE WERE DECLARING AN EMER AND NEEDED TO GET OUT OF THAT AREA! WE WERE THEN VECTORED S AND A VERY SHORT TIME LATER WE BROKE OUT ONTO THE CLR WITH ZZZ IN SIGHT. WE WERE APPROX 25 MI FROM THE ARPT AT THIS POINT. WE ASKED THEN TO BE VECTORED BACK TO ZZZ FOR AN APCH. THE CTLR THEN CHANGED OUR RWY 4 TIMES AND ASKED US TO SLOW TO 170 KTS. WE DECLINED THE SPD TELLING HIM THAT WE WERE UNABLE; BUT ACCEPTED THE FINAL RWY. THE CTLR ASKED IF WE WERE GOING TO TERMINATE THE EMER AT THIS POINT; AND WE SAID YES. BECAUSE SAFETY AND CTLING THE ACFT WAS OUR #1 CONCERN; WE LITERALLY DID NOT HAVE TIME TO CONVERSE WITH THE FLT ATTENDANTS; AS WE WERE ONLY 15 KM TO THE ARPT. WE DID THOUGH AS SOON AS WE GOT ON THE GND. THEY RPTED TO US THAT EVERYONE WAS OK. WHILE WE TAXIED IN; WE CALLED FOR MAINT TO MEET US AT THE GATE. I GOT OUT OF THE COCKPIT AS SOON AS I COULD TO BE AVAILABLE FOR PAX IF NEED BE. SOME PAX HAD ALREADY DEPLANED. ALL PAX SEEMED FINE AND SOME THANKED US. NO NEGATIVE COMMENTS WERE SAID OR HEARD. I DID ASK THE FLT ATTENDANTS IF THEY WERE OK; AS WELL AS THE PAX; AND THEY SAID YES THEY WERE ALL FINE. MAINT THEN SHOWED UP AND I BRIEFED THEM AND THEY PERFORMED AN INSPECTION. I THEN CALLED DISPATCH AND TOLD THEM OF THE SEVERE TURB; AND THAT WE HAD ALSO DECLARED AN EMER. I LATER FOUND OUT THAT THE ACFT WAS FINE.

Data retrieved from NASA's ASRS site as of May 2009 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.