I wonder if for some reason they decided to dump as much as they could because they were afraid the public might have become upset if they discovered that the weather service had more or less failed to understand the event as it happened and notify them in time to give them time for cover?
It's rather interesting that you should bring that up. There were some key equipment failures at the Lansing, and Muskegon offices of the U.S. Weather Bureau, on Palm Sunday 1965. Both of these instances would drastically affect the people in the path of the storms, and the neighboring weather offices downstream from their areas.
The teletype machines had failed on Saturday at the weather office at Capitol City Airport in Lansing. This meant that they did not receive any warnings from the neighboring U.S. Weather Bureau offices in Fort Wayne and South Bend, Indiana. Likewise, the office in Grand Rapids, did not issue any warnings in their county warning area, as they were caught completely off guard. However, since the teletype machines had failed due to a circuit problem, the Lansing office would never have received them anyways.
Over in Muskegon, a vacuum tube had burned out in their obsolete WSR-3 radar console, which rendered it inoperable. They were not aware of the severe thunderstorms moving into their area off Lake Michigan. Moreover, the Grand Rapids office was totally dependent on the radar reports from Muskegon, which never came. Therefore, when the storms came ashore and were moving east-northeast at speeds up to 70 MPH, by the time they had received a report of a tornado 20-30 minutes later, that information was too old to be any value to nearby communities.
The only warning issued in South Central Lower Michigan on Palm Sunday 1965, was from the Lansing office, which used a telephone fanout list to notify key media and public safety contacts in Jackson County. They firmly believed the first tornado was heading towards Jackson, and for everyone there to take cover. Sadly, in the chaos that evening, they never thought to call the U.S. Weather Bureau at Detroit Metro Airport to let them know that a confirmed report of a tornado had been received near the community of Hillsdale. That information would have been priceless to the radar operator, who could have actually tracked the progress of that storm. Subsequently, Detroit could have issued a tornado warning for Lenawee and Monroe Counties.
In the days and months that followed, there was a lot of finger pointing between local officials and the U.S. Weather Bureau. While politicians at the city and county levels, blamed the weather forecasters for being woefully unprepared with outdated equipment and policies. Conversely, the U.S. Weather Bureau said that it was up to local communities to bolster their preparedness plans, and if they would have done so, the death toll would have been much lower.
Another problem back in 1965, was that public safety agencies used disparate two-way radio systems, which often used different frequency bands. Likewise, in Michigan there was no specific frequencies set aside for intersystem (interoperable) communications between various first responders. While such systems existed in neighboring states, Michigan was behind the rest of the nation at that time. Sadly, it took the Palm Sunday tornado outbreak to get the ball rolling in that area.
In 1965, the telephone was the primary means of point-to-point contact, between public safety agencies in Southern Lower Michigan and neighboring Indiana and Ohio. While Indiana, was making vast changes and moving to VHF-High band radios, for their police and fire communications. Michigan on the other hand, was still on VHF-Low band in the 33, 37, 39 and 46 MHz bands. Likewise, it was very hard for fire and police departments in one county to talk with their own units, let alone with a neighboring county or state.