I think #NOAA / #NWS can greatly improve their text / e-mail alerts.

(1) Offer specific metro areas or individual counties. No freeform personalized sign-ups.
(2) Consolidate. If there is flooding expected on multiple rivers / streams in an area, put them all into ONE alert, with timed predictions. Same for tornadoes and other events. "Minor flooding just SE of Lawrence KS beginning at 3PM, major flooding near KCI airport at 4PM..."
(3) Consolidate. Add updates to the same web page as the original alert. When sending original alerts, say "check this page for updated info on this event" ... so no more need for continued SMS messages. Same for "alert cancelled" ... it is rare that these require separate messages. Just update the page, so recipients can check and see that the event is cancelled.
(4) Consolidate. If you've already declared a watch, place warnings on the same web page. But because a warning means danger is imminent, you may still send a separate SMS and e-mail message about it. This does not mean that someone should receive 40 separate warnings as a storm crosses the #Kansas City metro ( #kcks #kcmo ). See (2) above.
(5) Some counties are too small to warrant separate coverage. Consolidate them with neighboring counties. For example, Vernon County, #MO, and Bourbon County, #KS should be grouped with nearby counties including Crawford County, KS.