Dude, where’s my snowstorm?

Funny things happen in the world of weather. As a meteorologist, I have seen more than my fair share of busted forecasts, surprise hits, forecasts that actually panned out, and surprise misses. Another snow event looks likely to join the long, long list of the ones that got away for parts of the Mid-Atlantic. As of Sunday we discussed a winter storm both in the context of the Mid-South, which is still intact but also for the Mid-Atlantic. Just for comparison, here is the snow forecast over the last several model runs for PM Wednesday and Thursday morning in the Mid-Atlantic.

Going back to Friday, the snow forecast (this, from the European model) has cratered over the Mid-Atlantic, as the storm track has become more suppressed. (Pivotal Weather)

That is about as ugly an outcome as I’ve seen for a snow lover. And that’s the European model, one of the better performing ones historically with snowstorms. So what the heck happened?

Well, basically, nothing comes together in time. If you look at the last few days of models runs from the European model, you can see a slow trend away from meaningfulness. On Saturday, the Euro depicted a 987 mb low off Delmarva. On Sunday it shifted a little to the southeast, and then yesterday, it popped up to 1001 mb and well southeast. The consequence here is that the storm basically never gets together now off the East Coast in a position close enough to deliver snow to the Mid-Atlantic, with the exception of maybe the Virginia Tidewater and northeastern North Carolina.

A comparison of ECMWF model runs over the last 4 days shows the surface low on Thursday before sunrise shifting from near Delmarva to well off the North Carolina coast. (Tropical Tidbits)

You can look up higher in the atmosphere and see how the more bombastic idea of a storm near the Mid-Atlantic coast gradually faded over the last few days too.

A stronger trough and disturbance around 10,000 feet up on the models over the weekend has opened up some and shifted south, reducing how far north the impacts get. (Tropical Tidbits)

You can also look under more of the hood here and see how the ensemble members of the European model summed things up. The number of members with 4 inches of snow or more got to 80 or 90 percent in portions of Delmarva on Sunday before plunging to 10 percent yesterday.

Of the European ensemble model’s 51 members, nearly 40 to 80 percent showed a 4″+ snowstorm in their Saturday runs over a broad chunk of the Mid-Atlantic. That shrunk to just a small area south of Salisbury, MD and north of Cape Hatteras today. (Pivotal Weather)

Storms like this with such a potent push of cold air require a balancing act to come to fruition on the East Coast in particular. If one of the pieces of the puzzle doesn’t time itself perfectly, the whole thing can shift markedly in one direction or another. In this case, the storm didn’t disappear, it just gets going too far southeast and offshore to make much difference. Suppression is the word we often use, and the whole mess got suppressed to the southeast. And thus, your snow forecast maps reflect the change in ways that will disappoint many winter lovers in DC or Philadelphia or my former stomping grounds of South Jersey.

This will be a potent snowstorm for the Virginia Tidewater, including Virginia Beach and Norfolk and a decent little storm for Richmond as well. (NOAA)

In fact, this whole mess gets so suppressed that even as the storm comes northeast, it passes far enough off the coast of Canada to even avoid impacts in the Maritimes. Now, notably, the 7 to 13 inch forecast for Norfolk is actually quite impressive. If the high end of that range were to verify, it would be a top ten storm for the Tidewater and the biggest since 2010. Most areas will not see more than 10 inches in all likelihood, but either way, this will be a healthy snowstorm for Hampton Roads.

Overall, this proves another lesson in treading carefully with all storms, especially winter ones. This is one reason why the NWS usually doesn’t provide snow forecast maps more than 3 days in advance of winter storms. Often times, so much changes so erratically in that day 3 to 7 timeframe that those maps have little real value. Sharing speculation may be fun, but it won’t really give you a better reputation as a forecaster.

After a terrible flooding event for many, much of the Mid-South now readies for a snowstorm

Summary

  • Flooding in Kentucky and West Virginia came to fruition as forecast, with at least 8 people killed thus far and numerous rivers seeing their worst flooding since 2021 and in a couple cases near records.
  • Next, a major winter storm will bring widespread moderate to heavy snow through the week from the Plains into the Mid-South and Mid-Atlantic, along with possible ice in the Carolinas.
  • Some record cold will follow that storm in the Plains, Texas, and the South before a more notable warm-up begins to expand after next weekend.

Kentucky & West Virginia flooding

Yesterday’s high risk of rainfall that we noted on Friday came to fruition as forecast unfortunately.

Use the slider to see a comparison between the forecast rainfall over Kentucky and what was observed yesterday. (Pivotal Weather)

Overall, the NWS forecast was fantastic for the area, with some areas in eastern Kentucky and southwest Virginia seeing a bit more rain than expected. Otherwise, the idea of 3 to 7 inches with higher amounts verified very well. The flooding that’s ongoing is rather bad, and the death toll is at least eight. There are flood warnings all over Kentucky right now, as well as into West Virginia and Ohio and even southwest Pennsylvania. Some notable flooding reports include the Tug Fork River in West Virginia, which saw its second highest crest on record and highest since 1984.

The Tug Fork River at Williamson, WV experienced its second highest crest on record. (NOAA)

The South Fork of the Kentucky River in Booneville, KY is going to come extremely close to the record that was set there back in 2021.

The South Fork of the Kentucky River will crest extremely close to the 2021 record of 44 feet. (NOAA)

For many other locations along the Ohio River and elsewhere in Kentucky, the river flooding will be the worst since 2021 as well.

Here comes winter again

The good news now is that the rain is done, and we will get a little time to get some of this high water flushed through the system, though not all of it, especially on the larger rivers, like the Ohio. But the bad news is that cold and winter weather are on the way to some of these same hard-hit locations. A significant and fairly southern track winter storm is on the way this coming week. The storm will get going as a couple strong disturbances track east of the Rockies and ultimately try to “phase” just off the East Coast, resulting in a large, potent nor’easter.

The ECMWF model’s depiction of the upcoming major winter storm that has prompted winter storm watches already across the Plains and Mid-South. (Tropical Tidbits)

The storm will develop late tomorrow night and Tuesday across the Plains, slide east across the Deep South or Gulf Coast, and then off the East Coast and toward Atlantic Canada, deepening the whole way. This will be a major storm with numerous hazards from heavy rain in the Deep South to potential severe weather to ice or sleet in the Carolinas to heavy snow to the north of there from the Plains into Kentucky to the Jersey Shore and southeast New England.

From the NWS Blend of Models below, you can see approximately how much snow is expected to fall. Anywhere in purple may well see 6 inches or more.

A significant snow swath will extend from Nebraska to Virginia to Nova Scotia this week. Very heavy snow between the ongoing storm and upcoming storm will impact Eastern Canada as well. (Pivotal Weather)

Some select preliminary snowfall estimates include 4 to 8 inches in Kansas City, 5 to 10 inches in St. Louis, 3 to 6 inches in Lexington, KY, 6 to 12 inches in Richmond, 5 to 10 inches in Atlantic City, and 4 to 8 inches on Cape Cod. Visit weather.gov to get the latest forecast for your exact location.

In addition, there are some pretty significant ice accumulations being flagged on a couple models for southeastern North Carolina, including Fayetteville, Goldsboro, and Greenville. A story to watch.

In addition, the cold coming in behind this storm will be notable, with numerous record lows possible on Thursday morning across the Plains, Texas, and the Deep South.

Numerous record lows are possible Thursday morning from the Dakotas through Texas and parts of the Deep South. (NOAA)

This may not match the intensity of what was seen last month in parts of the country, but it will be dang cold for sure!

For those who have had their fill of winter for a while, there will be notable changes coming. The 8 to 14 day forecast from the Climate Prediction Center shows high confidence in widespread above normal temperatures across much of the country.

Widespread warmer weather in the West should start to expand eastward in the 8 to 14 day timeframe. (NOAA CPC)

The East Coast may continue to see some colder weather, however. More to come!

Serious flooding risk in parts of Kentucky and Tennessee on Saturday

We’ve been talking a bit about the return of an active pattern to the Eastern United States, and indeed that is what has happened. Fueled in part by a record warm Gulf of Mexico, the amount of available moisture this weekend over the South will be just shy of records for the date.

Water temps in the Gulf are averaging new records for this time of year. (University of Arizona/Kim Wood)

As all this moisture streams north out of the Gulf, you can see the bullseye setting up tomorrow over Kentucky and Tennessee.

Precipitable water (or the amount of available moisture in the atmosphere) sits at the 99.5th percentile on Saturday from Memphis through southern Kentucky. (Polarwx.com)

You’ve also had a period of rainfall over the last 2 weeks that has averaged 300 percent of normal or more across Kentucky and into West Virginia.

The last two weeks of rainfall over Kentucky has been…hefty. (High Plains Regional Climate Center)

As a result, tomorrow’s storm carries a unique risk of being a major flooding producer for parts of Tennessee and Kentucky, as well as Arkansas, Ohio, and West Virginia. In fact, the unusual day 2 “high risk” (level 4/4) for excessive rain and flooding was triggered today by the hard-working and very busy meteorologists in NOAA’s Weather Prediction Center.

A high risk (purple) for excessive rainfall and flash flooding is posted for Saturday from about Dyersburg, TN through central Kentucky. (NOAA WPC)

The HRRR model from earlier this afternoon shows just relentless rain setting up over Kentucky later tonight and continuing into most of tomorrow. This model shows risk for up to 5 or 7 inches of rain in parts of the state.

The HRRR model depiction of tomorrow’s rainfall. (Pivotal Weather)

This seems more than reasonable, and indeed that’s about what the NWS forecast is for these areas.

As much as 4 to 7 inches of rain may fall north of Memphis into Louisville, potentially causing damaging and dangerous flooding in much of western Kentucky. (Pivotal Weather)

The bottom line? Dangerous, damaging flooding is possible in Kentucky and portions of Tennessee in particular tomorrow with somewhat lesser risks (but still considerable risks) surrounding those areas. The good news at least is that next week looks quieter in this region, with a wintry system possibly bringing some generally light snow but no significant rainfall.

On the southern end of all this, there will be a fairly healthy severe weather risk tomorrow too. The potential for some strong tornadoes will exist in parts of Louisiana, Mississippi, and Arkansas to perhaps as far north as Memphis.

A pretty potent severe weather risk exists for Saturday in the South. (Pivotal Weather)

An enhanced risk (level 3 of 5) is posted from northern Louisiana north to about Memphis and east to western Alabama. The hatched tornado risk indicates the chances of strong tornadoes in the top right image. Hail isn’t a major risk tomorrow, but damaging winds will be. Either way, the warm Gulf does tend to add fuel to the overall fire, and between heavy rain in the southern Ohio Valley and severe weather over the Lower Mississippi Valley, it looks to be a very active Saturday.

Ohio, Tennessee, and Lower Mississippi Valleys at risk for flooding, while SoCal warily eyes midweek rain and flooding risks

We’ve been talking about this shift to a very active weather pattern across the Eastern U.S. for a while now. It’s been mostly in the context of wintry precipitation which has panned out with mixed results overall. Well, the signal now is pretty clearly that wave after wave of storminess is going to lead to a pile up in rain totals over the Southeast at large, specifically from about West Virginia through northern Louisiana. We’ve already seen some flooding in portions of West Virginia recently.

90 day precipitation percentage of normal across the Southeast shows generally dry conditions have ruled. (High Plains Regional Climate Center)

The first round of storminess arrives today with a second round tomorrow. A third round is penciled in for Saturday. Each round will bring widespread rainfall with embedded thunderstorms that produce even heavier rainfall. The forecast rain over the next 7 days is pretty impressive. NOAA’s Weather Prediction Center shows roughly 4 to 7 inches in a very broad area between southern West Virginia and northern Louisiana, with a bullseye from northern Mississippi into Tennessee.

Rainfall over the next week between 3 systems will total upwards of 4 to 7 inches, with embedded higher amounts likely between southern West Virginia and northern Louisiana. (Pivotal Weather)

Because of the antecedent conditions (or what ground conditions are like currently), a lot of this rain will be welcomed and absorbed into drier ground, with the exception of portions of West Virginia. That said, there will still likely be areas of flooding, and there are currently flood watches posted for some areas.

An increased risk of flooding is likely in eastern Tennessee, which will be likely to see some flooding and still has some vulnerabilities in the wake of last season’s Hurricane Helene. (NWS Morristown, TN)

There can indeed be too much of a good thing, and it’s another round next Wednesday or Thursday that will probably be another one to watch. Models actually disagree on storm track and potential for wintry precipitation so there’s a lot here to unpack still. That said, it was enough to get a notation on the day 8 to 14 hazards outlook yesterday, with flooding possible.

Another round of heavy precipitation is possible next week, along with wintry weather to the north, though it’s far too early to say how much and what. (NOAA CPC)

I think the main takeaway here is that, while a lot of focus will be on the wintry weather to the north of these storms, the highest impact weather will likely be from multiple inches of rain that fall in the next 7 to 10 days or so across parts of the Southeast and the potential for flooding.

Southern California

A significant rainstorm is going to impact Southern California beginning later tomorrow and especially on Thursday. There is already a moderate risk (level 3/4) for excessive rain and flooding, but especially mudslide and debris flow concerns over recent burn scars. The trouble is less the total amount of rain but how quickly it falls. Especially on Thursday, there will be the potential for torrential rains in parts of the LA Basin, perhaps accumulating at the rate of an inch an hour or even a bit more in spots. If you live on the Gulf Coast, that may sound like weak sauce, but the reality is that type of rain over fresh burn scars and in a city with terrain can cause some pretty bad flooding issues.

Torrential rain is possible in SoCal on Thursday, leading to a moderate risk (3/4) for flooding and debris flows. (NOAA WPC)

Total rainfall should be on the order of 1 to 3 inches with higher amounts likely in spots, especially in the foothills and mountains. Debris flows are a long-term concern after fires like the ones experienced around Los Angeles this year, so unfortunately the next couple years in particular will be challenging in those areas trying to recover.