If you’re tired of the sub-zero temperatures — some warmth is on the way. National Weather Service meterologist Mark Russell says things aren’t going to change right away. He says it’ll be a slow warm up over the next 48 hours as there’s still a lot of cold air over northern Iowa. He says temperatures there were still in the 15-to-20-below range at mid-morning. Russell says the sub-zero blast of air is something that blows in from Canada on occasion this time of year. Temperatures are well below normal, but it’s not that unusual to have that cold air blow in. Russell says it’ll be another night with the furnace working overtime before things warm back to normal. Things are expected to warm up into the 20’s by late Wednesday. Russell says a series of fronts will move through the rest of the week and that could bring more precipitation — Russell predicts the precip will fall in the form of snow. He says there could be light snow Wednesday into Thursday in northern and eastern Iowa. Then there’s a chance for more snow Thursday and Friday.