Matt Lanza

A look at Sunday and Monday’s severe weather factors and the extension of winter in the Northern Plains & Upper Midwest

Today, we want to offer up a quick update on next week’s severe weather chances, as well as a look at prolonged winter weather in the Upper Midwest and Northern Plains.

Headlines

  • Severe weather risk Sunday and Monday looks somewhat limited and confined to the Southern Plains and perhaps the Mid-South or Deep South.
  • Two winter storms will bring snow to the Upper Midwest and Northern Plains; one tomorrow and the other with the Sunday/Monday storm.

Just how serious is early next week’s severe weather risk?

Next week continues to look like a slightly more active one across the country, with some severe weather possible. The Sunday/Monday timeframe in particular has stood out for awhile now for that potential. And indeed, the Storm Prediction Center has now highlighted portions of Texas, Oklahoma, and Kansas for severe weather risk on Sunday.

A 15% severe weather risk was introduced today for day 5 (Sunday) for portions of Texas, Oklahoma, and Kansas. (NOAA SPC)

One of the reasons to argue against significant, widespread severe weather early next week is tomorrow and Friday’s storm that travels along the Gulf Coast and amplifies off the Southeast coast. That system emerges off the Southeast coast on Saturday morning before amplifying a bit over the weekend and meandering just offshore of the Mid-Atlantic and Southeast.

An animation of available atmospheric moisture and surface pressure shows that as a storm deepens off the East Coast, it limits how much Gulf moisture is involved in the early week severe weather risk. (Tropical Tidbits)

From the animation above, you can see that the shaded values representing precipitable water in the atmosphere, or how much available moisture there is expected to be is blunted somewhat by dry air on the backside of the storm off the East Coast. So despite a vigorous storm forming in the Lee of the Rockies, it still may not be enough to really push the needle up in terms of moisture, or what would otherwise be a pretty serious severe weather pattern.

All that said, given the intensity of the storm emerging off the Rockies, there should still be enough for a severe threat, just perhaps more localized and/or suppressed than we would otherwise see. For now, the Storm Prediction Center continues to advertise predictability as “too low” for Monday. We’ll continue to watch, but the Southern Plains seem most prone to it right now for Sunday, with some migration eastward to the Mid-South or Deep South on Monday.

Making up for lost winter in the Upper Midwest and Northern Plains

The Northern Plains saw a rather benign winter this year. The 13.5 inches of snow in Bismarck for December through February was in the lower third of winters historically. It was worse in Minneapolis, which saw their 9th least snowy winter period, with only 11.1 inches of snow from December 1-February 29th. For Bismarck, they’ve only had a bit over an inch of snow this month. Minneapolis has seen a trace of snow. But we’re going to make up some ground over the next couple days. The first storm arrives tomorrow evening, bringing a general 3 to 6 inches with higher amounts from northeast Montana into Wisconsin.

Snow forecast totals over the next 48 hours with the first storm. (Pivotal Weather)

A second storm, the same one that will help bring some severe weather to the South will deliver another round of snow to the North. This one may be a bit more potent. A wide swath of 6 to 8 inches of snow is possible in the same general areas with this one Sunday into Monday. This storm could even linger into Tuesday in spots. The trick with this storm will be how much mixing with rain or sleet we see in those areas. That could cut down totals a bit for the Twin Cities. But there will likely be an axis of heavier snowfall that could occur in western Minnesota or eastern South Dakota.

A view of the potential for 6 inches or more of snow with the Sunday/Monday storm in Minnesota. (NWS Twin Cities)

Whatever the case, a storm with more snow for the Twin Cities and the heaviest snow west and southwest of there is likely Sunday into Monday. One disappointing aspect of this storm is that as you roll into Canada, the snow forecast drops off a good bit.

Drought is pretty severe in western Canada, particularly in Saskatchewan and Alberta into northern BC and the Northwest Territories. (Environment Canada)

They desperately need moisture up there, particularly after last year’s catastrophic wildfire season. Unfortunately, these storms will do little to help the areas most in need.

As we March toward hurricane season, where do things stand this month?

As we’ve done since January, here’s our monthly update on some of the key factors we can look at ahead of hurricane season. We advertise ourselves as being hype-free, and we continue to want to keep folks grounded ahead of this hurricane season. But it’s becoming increasingly difficult to objectively look at things without concluding that the upcoming hurricane season could be a very active one.

Headlines

  • El Niño continues to slowly erode away in the Equatorial Pacific.
  • La Niña development continues to look plausible, if not likely by August or September, a feather in the cap of an active hurricane season forecast.
  • Atlantic Ocean sea-surface temperatures remain excessively warm virtually everywhere that matters.
  • We are likely to see some very active hurricane season forecasts get released in the coming weeks.

El Niño’s demise: It continues

Since last month, we’ve seen further declines in the sea-surface temperature (SST) anomalies in the Equatorial Pacific region that defines El Niño and La Niña.

A view of Equatorial Pacific water temperature anomalies from the surface (top) to 450 meters below (bottom) showing continued gradual erosion of El Niño. (NOAA CPC)

We’re now explicitly colder than normal in the far eastern Pacific, though still warmer than normal across the majority of the basin. So, El Niño is not dead yet, but it’s weakening steadily. This continues to fall in line with predictions that suggest we fall out of El Niño conditions in the key “3.4 region,” which is essentially most of the left half of the image above, by June or so. The chart below is the European Center’s forecast for ENSO 3.4, a proxy for El Niño, and you can see this month that about 85-95 percent of individual ensemble members suggest cooler than average SSTs or straight up La Niña conditions by August.

La Niña conditions continue to look likely by the time we get to August or September. (ECMWF)

Again, we are in the midst of the “spring predictability barrier” for forecasting El Niño and La Niña, meaning that historically, we’ve struggled to nail the forecast in the springtime. But, given the typical progression of strong El Niño events such as the one that’s fading and the current state of the tropical Pacific, one would assume the odds are stacked in favor of La Niña development by late summer.

This continues to imply that atmospheric conditions in the Atlantic for the peak of hurricane season will likely become increasingly favorable for storm development.

Atlantic Ocean SSTs: Continuing to rage warm

I think we can keep this section pretty brief. It does not take a meteorologist to look at this map of current Atlantic SST anomalies and conclude that the entire main development region (MDR) of the Atlantic, the Caribbean, and Gulf are very warm.

This is a very warm map of mid-March sea surface temperature anomalies. (Tropical Tidbits)

If anything, things look as favorable or more so than they did a month ago. There is plenty of warm water available.

For the Gulf, I tell people not to panic yet because it’s a lot more prone to changes as we get closer to hurricane season. It can swing more based on weather changes as we head toward summer. We’ve seen an alarmingly warm looking Gulf for several consecutive springs now, but it tends to moderate some by summer. I think the Gulf is just warming earlier than normal, so it says less about peak hurricane season than the rest of the Atlantic basin might imply. In other words, because of climate change and other factors you should expect a warmer than normal Gulf in springtime now. The Gulf will probably end up warmer than normal during hurricane season as well, but the hope is that it won’t be quite to the degree above normal it is right now. The rest of the Atlantic? It’s a little absurd for this point, and it does raise concerns if you extrapolate it out into hurricane season.

Putting it all together: A busy season is increasingly likely

It’s still early, very early. But there are clear signals emerging here that strongly favor an active hurricane season. As we get outlooks in the coming weeks, I just want folks to be prepared for the fact that they may end up being forecasts of impressive numbers given these factors. Most forecasts last season predicted an active one in the face of a rapidly developing El Niño. If the SSTs are similar this summer and we transition to a less hostile atmosphere, that virtually guarantees that this season’s forecasts will be big.

One large caveat: This says nothing right now about who might be impacted by storms this season. No one can tell you that with any level of consistency or high confidence right now. If we have 100 storms and they all end up out at sea, it was still a really active season! But few people would have suffered from it. So an active season does not necessarily mean an active season for you. But it does give us some pause and it should encourage you to prepare this year, especially if you’re one who tends to try to ride through the season on hope, luck, or a prayer. I think this is a good opportunity to prepare for a hurricane season just in case. More to come.

Chilly temperatures in the Central and Eastern U.S. give way to perhaps some severe weather risk by the weekend

First off, sorry for being away all last week with some severe weather and a big thumping snowstorm in the Rockies. It was spring break week in Texas, and my family headed to the Northwest, or Southwest if you’re reading from Canada. Spent some time in Seattle and Vancouver, and the weather went from wet to sublime. A beautiful part of North America. But it’s good to be back in the saddle. Fortunately, we have a relatively basic week ahead.

Headlines

  • Cool temperatures dominate the Eastern 2/3 of the country this week, with frost and freeze conditions in parts of the South.
  • Two more delightful spring days in the Pac NW.
  • Severe weather looks isolated and confined to the Gulf Coast or Florida this week for the most part.
  • Potential for a more significant storm and subsequent severe weather next week in the Central U.S. or Southeast, but details are sketchy right now.

Eastern chill, Western warmth

For the eastern two-thirds of the country, the theme this week will be cool weather. We’ve got some solid cool weather expected up in the Great Lakes and Midwest, with what I’d deem “lesser cold” in the South.

Temperatures this week will average below normal east of the Rockies and above normal in the Northwest and much of California. (Tropical Tidbits)

That said, the only place I can find that’s expected to close in on a record low is Lakeland, Florida on Wednesday morning, with a low of 45°, just off the record of 43° from 1956. Meanwhile, Miami is forecast to get close to 90 degrees today, which is the previous record set in 2003.

Still, this setup will be enough to produce freeze conditions in a lot of places where the growing season is underway, mainly in the Deep South, which is blanketed by freeze warnings tonight.

Freeze warnings (purple) are posted from northeast Texas through southern North Carolina, almost to the Gulf Coast in spots across the South. (Pivotal Weather)

Meanwhile, the West is enjoying a stellar early spring stretch. Seattle hit 74 on Saturday, a new record, followed by a record tying 71 degrees yesterday. Back to the 60s there today. Portland hit 76 on Saturday, 75 yesterday, and is forecast to hit 76 today, which would actually be the first record high in this stretch.

High temperatures across Oregon today will test records in spots like Portland before a cooldown arrives for midweek. (Pivotal Weather)

The Pac Northwest will get one more day of stellar weather tomorrow before clouds, rain, and cooler temps return for midweek.

Severe weather next week?

On the severe weather front, it looks relatively benign this week, with perhaps one day tomorrow with an isolated severe risk in Florida and then another chance at it Thursday or Friday from the Gulf Coast into Florida. With cool air dominating things this week, a relatively suppressed storm track will follow, keeping most of the country quiet-ish.

The same cannot necessarily be said for next week, however. It appears that we’re going to get a significant storm developing off the lee of the Rockies. From there, it will track east or northeast, which should prime the Central US or Southeast for a chance at strong to severe storms.

Operational European model depiction of the forecast development and track of a strong storm system next Sunday through Wednesday in the Central U.S. Forecast details will change between now and then, but this could produce severe weather for the southern Plains and Mississippi Valley. (Tropical Tidbits)

Exactly how this unfolds is TBD, but I think we could see the severe threat begin as early as Saturday or Sunday and become more notable by Monday, hopefully winding down Tuesday. As of now, the Storm Prediction Center has not highlighted anywhere in their day 4 to 8 outlooks, citing low predictability. And indeed if you look at that map above, notice how there is also a storm system off the Southeast coast while this is happening. Situations like this can complicate how much Gulf moisture (a really necessary ingredient for widespread severe weather) ends up flowing north. I think we will see this change somewhat between now and then, with a lean toward severe weather risk, but confidence in details is far too low to pin down at this point. We’ll check back in on this Wednesday.

Hurricane season check-in tomorrow

Since it’s a quiet week, we’ll dive into hurricane season again tomorrow. We’ll take a look at where ocean temps stand this month and see if anything has changed with regard to the emerging possibility of La Niña. It remains far too early to say anything conclusive about the upcoming season, but we’ll check in on where we stand compared to last month.

Hail and heavy rain aims for the Deep South Friday, while rain and snow returns to the Northwest this weekend

Things were generally not super impactful yesterday, so we took it off. Our philosophy here is to try not to create a significant story when just a minor one exists. Today, we’ll discuss what’s happening with tomorrow’s severe weather chances and flooding chances. Big hail may be a story for portions of Texas, Louisiana, and Arkansas, while Alabama and Georgia face another wave of heavy rain that could produce flash flooding issues on very saturated ground.

Headlines

  • Large hail possible tomorrow from East Texas into northern Louisiana and southern Arkansas.
  • Heavy rain may lead to flash flooding in spots, particularly in Alabama and Georgia, where heavy rain already fell this week.
  • Rain and mountain snow returns to the Northwest and southwest Canada.
  • More rain for the Northeast, with wintry precip winding down in the Canadian Maritimes.

Sneaky soaker slides across the South

A storm system tracking across the country tomorrow promises to bring a fairly lively day of weather from Texas into the Deep South with severe storms and flooding possible.

A slight risk (level 2 of 5) for severe storms is posted for much of the South between East Texas and Alabama on Friday. (NOAA SPC)

A rather broad area of slight risk (level 2/5) is posted across the South between Texas and Oklahoma and Alabama for the potential of severe thunderstorms on Friday. Storms could include tornadoes, strong winds, and somewhat larger than usual hail risk. The Storm Prediction Center has highlighted a hatched area on their maps between about Tyler, TX through southern Arkansas, including Shreveport and Texarkana.

The primary concern with Friday’s severe weather may be a localized significant hail risk, with hail in excess of 2 inches in diameter (hen egg size) possible in a corridor between the Piney Woods and southern Arkansas, including Shreveport, LA. (NOAA SPC)

Hail in excess of 2 inches in diameter (hen egg size or bigger) is a possibility here, as we’ll have a few conditions in place in that smaller area that tend to historically favor bigger hail risk.

A moderate risk (level 3 of 4) for flooding rainfall exists for Alabama and Georgia, including Atlanta, Birmingham, and Montgomery on Friday. (NOAA WPC)

In addition to the storms (which spread across Georgia to the coast on Saturday morning), heavy rain is once again a good bet in the Southeast. After a storm delivered nearly 4 inches of rain to Atlanta earlier this week, another 2 to 4 inches may fall tomorrow night into Saturday morning. Thus, flood watches have been hoisted across Alabama and Georgia, including Birmingham and Atlanta, along with a moderate risk (level 3/4) of excessive rain and flooding for those areas.

Georgia looks particularly vulnerable to flash flooding tomorrow with heavy rain falling on already saturated ground from rains earlier in the week; the bullseye may again be close to Atlanta. (NWS Peachtree City/Atlanta)

Some places only need 1 or 2 inches of rain over 2-3 hours to lead to flooding, which will certainly be attainable tomorrow night in Alabama and Georgia. While not a massive flooding event, you should expect roadway flooding issues across that region later Friday night and Saturday morning, as well as minor to moderate flooding issues on rivers in the region through early next week.

Northwest stormy pattern cranks up

While California and to a lesser extent Oregon have been dealing with occasional big storms, the far northwest including Seattle have seen normal to below normal precipitation over the last couple months overall. Not terrible, but not great either.

Precipitation as a percent of normal since early January in the Northwest shows a cutoff between average to below average precip near the Columbia River. (High Plains Regional Climate Center)

That will change a bit over the next week. A series of storms between this weekend and next Tuesday will help mitigate recent dryness some. Anywhere from 1 to 2 inches will be possible from Vancouver south through Portland with higher amounts and fairly good snows in the Cascades, Olympics, and the Coast Range with slightly lower but no less helpful precip south into northern California.

Total liquid expected over the next week in the Northwest and southern British Columbia will be 1 to 3 inches between Vancouver, Seattle, and Portland, with higher amounts falling as snow in the Olympics, Cascades, and Coast Range. (Pivotal Weather)

The Sierra may see another foot or two of snow, especially the farther north you go. Whatever the case, the parade of storms will be needed, as the pattern is likely to turn warmer and drier in the West heading into later next week.

A warmer and drier weather pattern should establish around midweek next week in the West and continue through days 8 to 14. (NOAA CPC)

Northeast sees more rain

It’s been a wet stretch for a long time it seems in the Northeast U.S. As we discussed storms earlier this week for the Canadian Maritimes, the Northeast will get the rainy side of that. Another 1 to 2 inches of rain is possible for New England, the heaviest of which should occur in Maine over the next 3 to 5 days. 

Additional rainfall through the weekend will tally about 1 to 2 inches from Pennsylvania and New York into New England, with 2 inches or more in Maine. (Pivotal Weather)

It continues to look at if Atlantic Canada will see a helping of snow and ice over the next couple days. Anywhere from 30 to 50 cm of snow and 30 to 50 mm of ice are expected in Newfoundland. The most ice accumulation will likely occur on the south side of the Burin and Avalon Peninsulas. Ice will also occur for parts of Cape Breton Island and PEI. In addition, snow will occur through evening across PEI and southeast New Brunswick.

Snow totals look highest over the southern peninsulas of Newfoundland, with lesser amounts back across Cape Breton Island, northern Nova Scotia, Prince Edward Island, and New Brunswick. Ice is also a good bet in the southern portion of Avalon and Burin Peninsulas in Newfoundland. (Pivotal Weather)

The next storm Sunday into Monday should track a little to the north, which should yield a warmer outcome and more liquid than frozen precipitation across the Maritimes. Another storm is on track for next weekend.