ULLI 302200Z 20001MPS 4500 BR SCT050 OVC066 17/16 Q1006 NOSIG=
ULLI 302130Z 21001MPS 9999 SCT050CB OVC066 18/17 Q1006 NOSIG=
ULLI 302100Z 19002MPS 9999 SCT050CB OVC066 18/17 Q1006 NOSIG=
ULLI 302030Z 22002MPS 9999 SCT050CB OVC066 18/17 Q1006 NOSIG=
ULLI 302000Z 17002MPS 130V210 9999 SCT050CB OVC066 18/17 Q1006 NOSIG=
ULLI 301930Z 12003MPS 090V150 9999 SCT050CB OVC066 19/17 Q1006 NOSIG=
ULLI 301900Z VRB01MPS 9999 -SHRA BKN050CB OVC066 19/17 Q1006 NOSIG=
ULLI 301830Z 26002MPS 220V330 9999 BKN050CB OVC066 19/17 Q1005 TEMPO TSRA=
ULLI 301800Z 24004MPS 210V270 9999 -SHRA BKN036CB OVC066 20/17 Q1005 TEMPO TSRA=
ULLI 301730Z 22003MPS 170V280 9999 TS BKN036CB OVC066 20/17 Q1005 TEMPO TSRA=
ULLI 301700Z 23006MPS 4700 -TSRA BKN036CB OVC066 21/18 Q1005 TEMPO 20010G15MPS TSRA RMK 10L/23006G09MPS=
ULLI 301630Z 24002MPS 120V290 9999 BKN033CB OVC066 21/19 Q1005 TEMPO TSRA=
ULLI 301600Z 17002MPS 080V210 5000 -SHRA BKN031CB OVC066 21/19 Q1005 TEMPO TSRA=
ULLI 301530Z VRB01MPS 6000 -TSRA BKN033CB OVC066 23/18 Q1005 NOSIG=
ULLI 301500Z 06002MPS 030V090 9999 BKN033CB OVC066 23/18 Q1005 BECMG TSRA=
ULLI 301430Z 35002MPS 270V360 9999 SCT033CB BKN066 23/18 Q1005 NOSIG=
ULLI 301400Z 32002MPS 270V360 9999 SCT033TCU BKN066 24/18 Q1005 NOSIG=
ULLI 301330Z 36003MPS 250V360 9999 SCT033 BKN066 24/18 Q1005 NOSIG=
=
as you can see there were moderate to sever thundershowers and CU and CB's, so i bet this was no CAT but definitely shown on the WX radar
maybe the flight was operating at max range and a diversion around the wx was not possible without a fuelstop in lets say UNWW
just my educated gues
cheers