11.   But he greatly heightens the risk of more radical challenges to the system, with disastrous consequences for his presidency and serious repercussions for the United States.

12.   But the potential for weakness in consumer spending underscores the unusual nature of this recession and heightens the risks facing the economy in the next few months.

13.   But very low levels greatly heighten the risk of cerebral palsy and brain damage that shows up later in lowered IQ scores, according to a new study.

14.   Converging winds near a stalled front will further enhance the rain, heightening the risk of local flooding through Thursday.

15.   Critics argue that even without props or diapers, corrective parenting invests too much authority in the doctor, heightening the risk of abuse.

16.   Downpours will heighten the risk of flooding.

17.   Early this week a jet stream disturbance will emerge from the southern Rockies, heightening the risk for twisters in the southern Plains.

18.   Eight inches or more are possible in the mountains of central Arizona, heightening the risk of flash flooding.

19.   Even so, these warm-season storms can bring torrential rain, heightening the risk for local flooding.

20.   Friday, the low will churn east over the Midwest, heightening the risk of widespread strong to severe thunderstorms.