update on winter storm.... quite complex

[WXBUFFJIM]

Good morning and afternoon folks. A significant winter storm is expected to continue throughout this afternoon and last through Tuesday for some folks east of the rocky mountains. Let's detail this with a look at the latest computer model projections of this multi day winter storm sytem

12Z ETA

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Significant ice is occurring from Manhattan, Kansas through Kansas City, St Louis and Lexington, Kentucky south and eastward to the Ashville and Hickory, North Carolina area at this time with hourly rates at times up to 0.10. to 0.20 inches an hour. That's alot of freezing rain and we'll have to concern ourselves with not only travel problems, but power outages in these areas too. These areas will be hit the hardest by this icestorm while heavy snow is expected to the north of that from central Indiana, Ohio where 3-6 inches is expected, and into the Middle Atlantic states through tonight where 4-8 inches is expected in DC, Baltimore, and Philadelphia. Expect 3-6 inches of snow in Richmond with 2-3 inches in Newport News, VA and 1-2 inches in Norfolk and Virginia Beach, VA. Even the tidewater will get into this winter storm. If that wasn't enough, there will also be another significant winter weather event in the Ohio Valley, great lakes, and northeast beyond this period. let's get specific city by city.

In Ashville and Hickory, North Carolina, it's light snow now. However damaging ice accumulation is expected to begin later today and last into tonight. Up to 1/2 inch or more of ice accreation is expected, which could cause power outages and hazardous travel. Avoid I 81 and vicinity if neccessary. Significant snow is expected in Winston Salem with 2-5 inches of snow followed by 1/4 inch of ice on top of that. A messy situation.

Further north into Virginia, precipitation will start as all snow all the way to the coastal waters and tidewater area. For example, Lynchburg, Virginia can expect 4-8 inches of snow followed by 1/4 inch of ice on top of that. Richmond can expect 3-6 inches of snow with 0.10-0.25 inches of ice accreation on top of that for this afternoon into tonight. A winter storm warning is in effect for most of Virginia and west central North Carolina for today and tonight. Meanwhile, Norfolk and Virginia Beach will start as snow with about 2 inches likely before changing over to sleet and freezing rain after midnight tonight. This is why a winter weather advisory is in effect for the peninsula and the tidewater area of Virginia. This ice will accumulate about 0.10 inches, possibly locally more in spots, especially inland from the water. Then on Monday and Monday night, rain is the story for the tidewater area and the peninsula including the outer banks of north carolina as coastal takes over and increases the coastal winds off the warmer Atlantic ocean. Until then, it stays very cold with cold air damming fairmly in place.

Even further north now into the big cities, Baltimore, Washington DC, and Philadelphia, all three cities are now under winter storm warnings at this time. Timing all this out, it appears snow starts in DC at 6 PM this evening, Baltimore around 7 PM and Philly between say 8 and 9 PM. Prior to these times, snow could be falling aloft, but won't be hitting the ground because the boundary layer is too dry to start. But it'll quickly moisten up and get colder with the evaporative cooling effects. As a result, once snow starts, Snow will become heavy at times. 4-8 inches of snow is expected from DC to Baltimore to Philadelphia. Some places within this swath could see more than 8 inches of snow, but looks to be a isolated occurance for now and will only occur if we don't mix with or changeover to sleet, which would cut down on totals expeially from DC on southward into central Virginia. Meanwhile New York City will see snow moving in Monday into Tuesday with a significant accumulation likely, especially with Tuesday-Wednesdays coastal entity. That midweek heavy snow will be accompanied by wind in New York City, which increases the potential of near whiteout conditions. You think tomorrow is bad for New York, you haven't seen anything yet and same for New England. Stay tuned.

Meanwhile there is a serious situation further west today from the bluefields of Kentucky westward through the Ohio Valley, the gateway to the west St Louis, all the way to the eastern sunflower state of Kansas. Significant and damaging icing is occuring in these areas today. An icestorm warning is in effect for today into tonight for Lexington, Kentucky and extending west into Carbondale, Illionois. In these areas, expect 1/4 to 3/4 of an inch of ice accumulation, which will cause power outages and travel will be impossible at times. Ice is the worse type of weather to drive in, stay off the roads in these areas today through tonight. Same can be said in St Louis where a winter storm warning is in effect. Expect 1/2 inch of ice in St Louis today. Power disruptions are likely and travel is strongly discouraged. North of these places, snow will be the dominate precip type from Cleveland to Indianapolis to Cincinnati. 3-6 inches of snow is likely in these areas, which will cause travel problems. But snow is better to drive in than ice because it has more traction. With ice, you're off the road and into the ditch in a heartbeat. Bottom line for your safety and for the safety of road crews is stay off the roads in these area. The weather should improve by midweek in alot of these areas. The reason I say midweek in alot of these places is because of a snowstorm potentiall threatening the great lakes and ohio valley Monday into Monday night. More heavy snow is expected in places like Detroit, Indianapolis and Cleveland. Even Chicago gets into this storm with several inches early in the week. That's why we're not done with winter storm activity until midweek and that's only temporary.

Meanwhile further west, the situation is bad in Kansas City, Topeka, and Manhattan where icestorm warnings and winter storm warnings are up for today. Ice accumulations have already been between 1/4-1/2 inch in the KC metro and a few hundreths of an inch of additional accumulation is quite likely today.

So it's definitely serious situation with a cold wintry wx pattern in place. Part of the reason for this prolonged cold and winter storm activity in the eastern US is because of what's known as the greenland block. That's where high pressure aloftis firmly in place over Greenland. As a result, cold arctic surges plow into the United States and interact with storm systems and can become major winter storms such as the one we're facing now or the coastal event Tuesday into Wednesday. Such events have been known to happen with this greenland blocking pattern and this shows no sign of ending anytime soon. Thus the cold weather continues for much of the United States, especially east of the rocky mountains.

More updates and obs on this winter storm coming up later tonight. Have a good afternoon folks and stay safe.

Jim

[thstorm87]

would be very very nice, but I think your 4-8 for philly tonight is in serious trouble. More like 2-4. But I hope your right.