The levels of the Klondike and Yukon Rivers at Dawson City began rising last Friday, and groundwater levels are high.

But the flood risk for Dawson is assessed at low, largely because of the flood dike built along the waterfront in the mid-1980s and the disastrous flood of 1979.

“Forecast uncertainty is currently high owing to the delayed thaw,” said a Yukon government ice break-up forecast released Wednesday.

“Klondike River: high flooding potential if flows increase rapidly.

“Yukon River: moderate probability of sudden rise in water levels starting next week.”

On average, the past winter’s temperatures were above average.

Snowpack in the Dawson area is above average, while upstream basins also have average to above average snowpack, as reported in this month’s snow bulletin.

Ice thickness measurements vary from above to below average based on location, as a consequence of the dynamic freeze-up.

Temperatures have been cool across the Yukon during April, with above-average precipitation and more overcast days than usual.

“This has delayed visible signs of ice degradation,” the forecast says.

“The current conditions increase the likelihood for ice jamming and high water levels during breakup.”

Daytime highs above zero with overnight freezing have led to a slow initiation of snowmelt across the territory.

Temperatures peaked around April 20, then cooled off again. Most streams and rivers are showing a limited response to snowmelt.

This includes slowly rising water levels on the Pelly, Stewart and Yukon Rivers.

“The Klondike River has shown minimal response to date,” the forecast says.

“The ice cover is still intact and snow-covered on most Yukon rivers.”

The current Environment Canada forecast for Dawson calls for a mix of sun and cloud into this weekend with daytime highs above zero and overnight lows below freezing.

Starting Sunday, overnight lows are expected to remain above freezing. Scattered snow and minimal rain are forecast for most of the Yukon from the Klondike to the South over the next few days.

There is the potential for rain in the Klondike region on Monday.

“Water levels have started slowly rising, and the rate of rise is expected to slowly increase as warmer daily maximum temperatures return over the next few days,” the forecast says.

“A potentially significant rise in upstream freezing elevations in the coming days may result in more rapid increases in discharge.

“It is too early to judge how resistant the ice cover is, but the lack of visible (ice) degradation at this time suggests a dynamic breakup is likely with a potential for ice jam flooding. A sudden sustained rise of air temperatures above 15 degrees C is likely to result in a more severe breakup.”

For the Klondike River, minor ice movements and water level increases are expected in the coming days. Ice jamming could happen if flows increase rapidly.

“Flooding probability is considered high with the current conditions and weather forecast,” the forecast says.

The Yukon River ice cover remains mostly intact, with minimal areas of early deterioration showing.

“While model uncertainty is high, current model results indicate that the Yukon River at Dawson is unlikely to breakup prior to May 4, unless temperatures exceed forecast daytime highs and the rate of water level rise increases more rapidly than expected,” says the outlook.

“The potential for a sudden rise in water levels caused by ice jamming is considered moderate in Dawson starting next week.”

The flood risks in the Ross River and Carmacks areas have been assessed at low.