A major flood warning is in place for the South Esk river, which peaked on Wednesday morning but could swell again because of the high tide.
Commander Smith said the low-lying suburbs in Launceston along the Tamar river around Invermay and the bottom of the Cataract Gorge, which runs off the South Esk, were of most concern.
Decisions on reopening the city's Charles Street bridge, which has a floodgate in place, and several roads that have been closed due to the floods would be made after the high tide.
Evacuation orders remain in place for residents in Invermay.
About 50 homes were also evacuated from the suburb of Newstead after levels in the North Esk River reached their highest levels since 1929.
"All things going well we would like to think that moving into the evening we have some hope, in fact significant hope, that we can restore normality to the city," he said.
SES regional manager Mhairi Revie said flows in South Esk were the equivalent of 24,000 Volkswagens worth of water passing by every second.
"That's a lot of water and it's a very fast flow," she said.
Ms Revie warned locals not to become complacent or drive through floodwaters as they begin to recede in coming days.
SBS News reporter Julia Calixto was in Launceston and said residents in the low-lying suburb of Invermay were advised to evacuate at about 5.30pm on Tuesday in anticipation of the rising rivers.
An evacuation warning was also issued for the suburb of Longford but Calixto said it had reportedly been cancelled.
Floodgates were lowered on the Charles Street bridge on Tuesday night as precaution in case the river rose over the bridge.
On the search for the missing men, Commander Smith said grave fears were held for them as police scour the Evandale and Ouse areas.
"As time passes those fears worsen. However, it doesn't dampen our efforts in attempting to get a resolution," he said.
An 81-year-old man was swept into the rising Ouse River while feeding sheep in his backyard on Monday, while a second man, 63, is missing after his car was swept away in Evandale near Launceston on Tuesday.
His wife was plucked to safety but rescue crews and an aerial search has been unable to find her husband.
Less than 5mm of rainfall is forecast for Tasmania's north east on Wednesday, according to the Bureau of Meteorology.
More than 100 people have been rescued by helicopter from Tasmanian flood waters since the emergency began.
The SES has received almost 400 calls for assistance, while more than 200 properties have been flooded across the state.
As flood waters fall, authorities are urging people to obey road closure signs and follow previous safety messages.
People should not attempt to drive through or enter flood waters.
Search crews on Tuesday afternoon rescued a man in his 40s whose upturned kayak was stuck in a submerged tree near the Ouse river.
The man had used the kayak to try to enter his property, which had been cut off by the flooded river.
