As a historic winter storm pushes towards Florida, the National Weather Service issued Winter Storm Warnings for a large swath of the southern U.S., stretching from South Texas to Northeast Florida.

The rare winter weather warning , which is in effect locally from 7 p.m. Tuesday to 1 p.m. Wednesday, includes Nassau, western Duval, and most of Clay and Putnam counties. In Jacksonville, the warning includes areas west of I-95 and the St. Johns River.

Heavy mixed precipitation is expected, the weather service said, with snow and sleet accumulations up to 1 inch and ice accumulations around a quarter inch.

Ice accumulations can cause significant impacts to power lines, utilities, trees, some roofs and cause very dangerous transportation conditions, especially as accumulations rise above 0.10 inches and especially near 0.25 inches, the National Weather Service said. And there is high confidence of at least moderate ice impacts across Northeast Florida.

Much of Northeast Florida is also under a Freeze Warning from 8 p.m. Monday until 9 a.m. Tuesday as temperatures are expected to drop below freezing early Tuesday. A Freeze Watch was issued for Tuesday evening through Wednesday morning, when snow, sleet and/or ice are expected.

The cold weather led to the postponement of Monday's Martin Luther King Jr. Day parade in Jacksonville and the relocation of Monday's inauguration ceremonies of President Donald Trump to inside the Capitol building in Washington.

Any snow or ice accumulations would be the first in Jacksonville in 35 years, when a pre-Christmas storm dropped nearly 2 inches of snow across much of Northeast Florida on Dec. 23, 1989, wreaking havoc for drivers on Jacksonville's roads and bridges.

According to WeatherTiger’s Ryan Truchelut , the Winter Storm Warnings are the first for Florida in seven years.

Before you get on the road: Drivers could face black ice on roads on Monday morning, NWS warns. But what is black ice?

How much snow and ice will Jacksonville get?

Parts of Jacksonville, especially along the I-10 corridor and areas west of I-95 and the St. Johns River, could see snow and sleet totals up to 1 inch and ice accumulations around 0.25 inches, according to the Winter Storm Warning issued by the National Weather Service.

How cold will it get in Jacksonville?

What are the record-low temperatures in Jacksonville?

Has it snowed in Jacksonville?

How cold will it get elsewhere in North Florida?

Why is snow so rare in Florida?

The most basic answer is that subfreezing temperatures in Florida tend to be brought on by cold fronts, which generally produce dry air.

Florida’s best chance of seeing snow happens when a storm pulls in moisture from the Gulf of Mexico while cold air is being pushed from the north. Of course, if cold air is moving south, it’s likely pushing that moisture away from Florida, hence the conundrum.

The more complicated reason snow is rare in Florida is almost everything about Florida, from its geographical features to its proximity to the equator, discourages the conditions needed for snow.

Florida’s warm temperatures are the first problem. The second issue is that Florida, the Sunshine State, gets a lot of sunlight because of how close it is to the equator. That sunlight and warmer temperatures tend to keep sustained cold air at bay, preventing it from amassing in quantities for snow to form.

Florida is also a pretty flat state, and its highest point, Britton Hill, is only about 345 feet above sea level. That doesn’t give cold air a lot of places to hang out.

Lastly, there’s the Gulf of Mexico. The Gulf is a relatively warm body of water, and it acts as a large temperature moderator for Florida.

What’s needed for snow to form?

The conditions required to produce snow are typically generalized. Most people know that it needs to be at or below 32 degrees, which is considered the threshold for water to freeze. That's not the only condition where snow can form, however.

Snow can still form even in temperatures as high as 33.8 degrees. There are occasions when a higher layer of atmosphere is slightly above freezing where the snowflake might start to melt as it passes through that layer but can still make it to the ground as snow.

Another special case is referred to as the "wet bulb" effect. The wet bulb temperature is the temperature air reaches when water evaporates into it. Snow can still manage to form if the height where the wet bulb temperature reaches freezing is less than 1,500 above the ground.

In both special circumstances, the snow will be wetter and stickier than traditional fluffy and dry snow.

Brandon Girod of the Pensacola News Journal contributed to this report.