Severe Weather Threats for Central Plains Monday-Wednesday

After a start to a 2018 tornado season which has featured numerous tornadoes across the Deep South and even scattered tornadoes out West, but not a single tornado in Nebraska, Kansas or Oklahoma, it appears near certain the tornado drought for the Great Plains will come to an end early next week. Something which as been missing thus far…pattern favorable to severe for widespread severe thunderstorms across the Central and Southern Plains…will ramp up beginning Monday across the High Plains, shift eastward Tuesday with a peak higher-end risk for more widespread severe storms Wednesday. The jet stream, the river of air separating the cold Arctic from the warmer mid-latitudes will send a major trough of low pressure over the Western US, temporarily cooling that region down, warming up the Plains, bringing in greater moisture from the Gulf of Mexico and setting up the ingredients for multiple days of severe storms.

 

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European Model forecast depiction of trough of low pressure in the upper-atmosphere over the Western US (forecast for 7 am CDT Tuesday May 1st). This system will contribute to severe weather for the Great Plains Monday-Wednesday.

A brief review since it’s been forever since the Plains have had severe weather and there might finally be something in my neck of the woods. Severe weather is defined by the phenomena. In the US, the criteria, which weather warnings revolve around are 1) large hail of 1 inch or larger, 2) damaging wind gusts of 50 knots/58 mph or higher or 3) a tornado. Severe convection (thunderstorms) needs three major ingredients to maximize their potential. 1) Instability, 2) Moisture, 3) Wind Shear. Instability is positive buoyancy (tendency to rise). This is aided not only by heat, but also by moisture as moist air is less dense than dry air at the same temperature. Wind shear is the change in speed and direction of the wind with height. Winds which turn and increase in speed rapidly with height can promote storm rotation, allow them to form isolated cellular structures called supercells. These can be long-lived, self-maintained and produce the most intense severe weather.

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Schematic of a classic supercell thunderstorm.

Of the three days I’m most concerned about for severe weather this week, Wednesday appears to be the most serious for the Central/Southern Plains for significant severe weather. But let’s take a quick look at all three days.

Monday, April 30th-

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The National Weather Service Storm Prediction Center has a Slight Risk of severe weather (2/5 on the scale) for much of the high plains from Texas through Kansas and then, extending farther eastward into Central/NE Nebraska into SE South Dakota. This covers a 15% chance of severe thunderstorms within 25 miles of a point. A more “Marginal Risk” exists surrounding it. This would be for the afternoon and evening hours as a weak disturbance moves out of the Rockies, increasing wind shear and temperature-based instability (upper-atmosphere cooling relative to warming near the surface…warm air rises into colder air) modestly for isolated severe weather. Large hail and damaging winds are the primary hazards, but moisture will be limited, keeping the event from being widespread.

Tuesday, May 1st-

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Beyond Day 3, there are now categorical outlooks, only probabilities. A 15% chance of severe thunderstorms within 25 miles of a point exists over Eastern Nebraska, Western Iowa, much of northern and Central Kansas into Western Oklahoma. This will likely be a bit more vigorous event from Monday, with the Tuesday disturbance being stronger with better shear profiles, more low level moisture available, and the combination of abnormally warm temperatures and higher moisture will mean higher atmospheric instability for tall, intense thunderstorms with strong updrafts. The storms will likely begin as supercells across Nebraska and Kansas before merging in the evening into an organized structure known as a “mesoscale convective system”. Basically a larger scale complex which can bring locally heavy rain and extensive damaging wind gusts. The initial storms will form along a cold front and threaten damaging winds, large hail and an isolated tornado.

Wednesday, May 2nd-

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Wednesday is currently the most serious day for severe weather, but some uncertainty still exists. A 30% chance of severe thunderstorms within 25 miles of a point exists from extreme SE Nebraska, across much of Kansas, into western and central Oklahoma. A greater 15% area extends beyond  that, including my area of Lincoln, NE. Wednesday, the main upper-level trough of low pressure over the West (seen in the above map) begins to shift eastward and a surface mid-latitude cyclone sets up over the central and southern  Plains. A dryline (boundary separating warm, moist air from the Gulf of Mexico to the east from dry desert air from the Southwest US) will be located north-south somewhere over central KS/OK with a warm front either over Southeast Nebraska or Northeast KS (this is in question). The ingredients overall suggest robust thunderstorms forming along the dryline and near the area of low pressure (at the the intersection of the dryline and warm front) either in the afternoon or early evening Wednesday which vigorous supercells capable of producing large hail, some significant, damaging winds and multiple tornadoes. A possibility exists for a few of the tornadoes to be strong (EF2+; see more about the Enhanced Fujita Scale) and because of the persistent upper-level dynamics and buoyancy, storms could last after dark, posing nocturnal hazards. Later, storms will eventually merge producing greater high wind and heavy rain threats. Isolated flash flooding could be an issue Wednesday night from any heavy rain events.

For me personally, the the greatest threat for severe weather Wednesday seems to be to my south, but given the lead time, I’m watching to see how the position of the warm front ends up. If it migrates northward in the forecast and my areas is more solidly in the “warm sector”, then we will be just under as much of a hazard as the current 30% area is now. However, I note from forecast experience that warm fronts in severe storm events are notoriously challenging to forecast for as even the day of the event as they can have difficulty moving as far northward as expected because of the cold air they must erode out ahead of them. Much can also depend on the storms the previous day and how they effect the overall regional environment (temperature profiles, areas of instability, position of fronts, etc). But Monday-Wednesday all have potential to be hazardous days with Wednesday being a more potentially significant tornado day after months of silence.

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European Model forecast depiction of Precipitable Water at 7 pm CDT Wednesday (how much atmospheric moisture is available for precipitation in an instantaneous moment). This does not say how much will fall, but just how moisture laden the atmospheric column is. The plume of abnormally high PW will mean the potential for storms with locally heavy rainfall.
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European Model forecast depiction of dew point temperature at 1 am CDT Thursday May 3rd. Dew point is a measure of atmospheric moisture. The air behind the warm front and ahead of the dry line is warm and moist (with dew points above 60 F at this time), while the air ahead of the warm front is cool, with less moisture. The air behind the dry line is extremely dry and warm (dew point temperatures in the teens and 20s F).
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European Model forecast simulated upper-atmospheric water vapor imagery for 7 pm CDT Wednesday. The computer model simulates what the weather satellite water vapor channel may see Wednesday night as far as cloud structures. Water vapor imagery is a special type of infrared imagery where water vapor concentration in the upper atmosphere can be detected based on its “brightness temperature” (upper atmosphere is moist, it appears bright, upper atmosphere is dry, it appears dark, meaning water vapor is warm, located at lower level of the atmosphere). Here, the water vapor imagery is enhanced with colors to better interpret the temperature of the condensed water (clouds). We can see intense thunderstorm formation over Kansas at this time (likely supercells) with some further development into Oklahoma as well. This is NOT LIKELY how it will look exactly Wednesday evening, only a general idea of the storm structures based on the larger-scale flow pattern and expected ingredients for storm formation.

So stay tuned early next week. The weather will definitely be news yet again this Spring! Stay safe and be ready this week in these regions!

–Meteorologist Nick Humphrey

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The Struggle of the Trees in the era of increasing extremes

As the Arctic continues to warm abruptly because of anthropogenic climate change, the jet stream is exhibiting increasingly high amplitude waves later into the Spring growing season. This has been an apparent pattern through recent decades, but has become more pronounced in recent years. You can learn more about the research of Arctic amplification and the jet stream HERE (Dr. Jennifer Francis) and a more real-time analysis at the time HERE (January 2018; Paul Beckwith). Climate change is becoming abrupt enough, its changes on weather, long-term climate patterns and biology can be seen on yearly to seasonal timescales, where before, changes were over decades. So fast, scientific research can barely keep up and every story has “[faster, bigger, worse, more, etc] than expected”. Been the dizzying mantra of late-2017 into 2018 actually. It’s been rough on early agricultural activities in North America and Europe and it’s also been hard on trees trying to get started on first leaf growth.

Here in Lincoln, NE, the trees the week of April 24th have been struggling to get started with leaf growth. Lilacs are running 16-20 days behind first leaves because it has simply been too cold. We’ve had a few more warm days, recently, but yesterday and today…more chill.

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Here’s a photo of my son from this time a year ago. Notice the trees.

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Here’s from a walk I took on Monday.

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Tuesday…

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Seeing so many leaf-less trees with only some trying to bud has left me with a weird spooky feeling going for walks. And on Monday, walking down the street for thirty blocks (longest walk I’ve done in awhile) was actually hot because of the lack of shade from any leaves. And if you want to know just what stresses these trees have been through, it’s not just about persistent chill over the course of weeks. Very extreme temperature variability as well.

-April 13th. High temperature 82 F after the passage of a strong warm front associated with the powerful midlatitude cyclone which produced blizzard conditions across the Northern Plains and severe weather in the Deep South that week/weekend.

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April 14th. Twenty-four hours later. Non-diurnal temperature drop from April 13th’s high to 32 F following the passage of a powerful cold front. This was the most extreme temperature change I’ve ever experienced at the same location (and this photo is from the same parking lot as above, looking in the opposite direction). I’ve lived in Seattle, WA, Lincoln, NE and Brookings, SD. 50 degree F temperature drop. From early-June to early-February weather conditions.

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Other locations, such as in Oklahoma experienced temperature changes last week of 50-60+ degrees in 10 hours (near freezing to around 100 degrees)!!

More persistent warming and less temperature variability is expected this weekend into next week. It may finally start to feel like Spring where I am. Severe weather looks possible to impact the Southern Plains next Tuesday and Wednesday. One oddity of note are no tornadoes reported so far in Nebraska, Kansas, or Oklahoma in 2018. Nebraska typically averages (1991-2010) six tornadoes during the January-April period, with Kansas and Oklahoma averaging 17 tornadoes. But so far…zero for all three states. Nebraska has been too cold and Kansas and Oklahoma have either been too cold and dry with occasional extreme heat (by April standards…again, 90s to  near 100 in the arid drought areas). Extreme to exceptional drought conditions with little rain (and obviously few thunderstorms) have been plaguing the Southern Plains for months. Some storms in May may decrease in intensity of the drought mildly, but very destructive drought conditions for agriculture and hydrology will continue across the Southern Plains and Southwest US. Hoping it will not spread north into Nebraska, but abnormally warm conditions are expected across the southern half of the Plains this summer. Harsh on the plants and crops going from long cold to a long, hot summer. Not to mention more monster wildfires and dust storms. Oklahoma suffered unbelievable wildfires last week.

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Wildfires which were ongoing the afternoon of April 17th in SE Colorado, Western Oklahoma, and the Texas Panhandle.
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A dust storm captured by satellite over drought-stricken eastern Colorado and western Kansas the afternoon of April 17th.

Check out this extensive (of what at the time was live) video on April 17th of the wildfires in Western OK as they were being chased by KFOR (Oklahoma City) reporters Val and Amy Castor. It’s 3 hrs worth of video, but it’s a Facebook video, easy to fast-forward through and you can see how bad the fires were as they happened.

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As mentioned, severe weather may escalate on the Southern Plains (at least Oklahoma and North Texas) next week. Nebraska has been fairly quiet on the severe storm front, but with the clmatological peak months coming (May/June), there will likely be an escalation of activity. Still remains how much more activity there will actually be. While one needs wave action in the polar jet stream to stimulate the movement of warm-moist air from the Gulf of Mexico and vertical wind shear needed for rotating thunderstorms, very pronounced troughs right over the Plains with large ridging extending into Western Canada can mean cool air intrusions to the east and much of the severe weather and heavier rainfall restricted to the southeastern Plains and Southeast as has been the case much of the winter. The now weakening La Nina pattern of the El-Nino Southern Oscillation has been partly to blame for this (as well as other randomly oscillating “teleconnection” patterns”). However, in addition, the intense climate change-induced Arctic heatwaves in this winter’s polar night (climatologically extreme heat, record low ice extents, ‘atmospheric rivers’ of heat and moisture and ocean storms in the Arctic Ocean) caused the wintertime stratospheric polar vortex maintaining the circulation around the Arctic to split. This has become increasingly consistent and more intense in its effect on the Arctic and mid-latitudes the past few winters. This produced very wavy jet stream patterns and areas of abnormally very cold conditions over Europe and the Central US as well as the repeated nor’easter pattern offshore the East Coast in March.

-Splitting and migration of the winter polar vortex in the stratosphere (10 millibar pressure surface, so lines are lines of equal height…above 33,000 ft in the mid-latitudes generally).

 

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There are signs in the long-range ensemble models that a highly amplified high pressure ridge build over Western North America late next week into early the following week, providing persistent abnormal heat and of course dry conditions. This would consistent with a pronounced positive phase of the Pacific-North American Pattern (PNA) which features abnormally high mid-atmospheric pressures and surface temperatures over western North America. Such a pattern would also decrease severe storm and rainfall potential on much of the Plains during the second week of May. While severe storms are never a positive for safety, the rainfall from convection is always a plus for keeping drought conditions at bay and the northern Plains are in need of regular rainfall as many places not in drought are still suffering precipitation deficits on the month and/or year. If Arctic sea ice retreats rapidly this melt season (and we’re within years of sea ice disappearing in the warm season), this may promote very amplified upper-level high pressure systems this summer as the low albedo (reflectivity) of exposed dark ocean warms the lower atmospheric column, causing thermal expansion and causing any upper-level high pressure systems overhead to respond with greater poleward amplification and strengthening. This could mean very anomalous heat and dry conditions in the summer which persist. This possibility seems focused on the West, although unusually high heat and continued extensive drought may impact the Southern Plains, depending on how the pattern regime sets up. Very important for agriculture this season which I’ll be watching. California, in particular, seems to be progressing into the climate change-induced “weather whiplash” pattern of extreme drought-rainfall, which will only worsen in the coming years. Intensifying drought this summer and the possible return of El Nino later this fall (still up in the air on that) could cause more of this. Lots to keep track of this year.

—Meteorologist Nick Humphrey

Stay safe out there today! Severe storms likely and in progress.

Nebraska is in the ice box still…but big storms, including tornadoes and significant straight line wind damage possible in parts of Indiana and Kentucky today.

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Warm, moist air, and lots of vertical wind shear. Good set up for some nasty severe weather.

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Prominent severe weather threat is between the polar and subtropical jets (northerly and southerly branches, respectively). In between, lots of mass is being removed allowing for storms to explode from below, intensify rapidly and maintain themselves in the highly sheared environment (winds rapidly increasingly with height).

There is a lot of speed shear, but not as much change in direction with height, which favors lines of storms. So the threat for damaging winds is quite significant, hence the “moderate risk” (4 out of 5 on the overall scale by the Storm Prediction Center) for a 45% chance of damaging wind reports within 25 miles of a point within the given region, and a 10% or higher chance of winds over 74 mph (hurricane-force). However, a significant tornado risk also exists for storms which do isolated themselves earlier this afternoon. So remain vigilant if you are in these areas and tell anyone you know to remain ready to take cover this afternoon and evening!

My part of Nebraska?

Unseasonably cold. Just straight up…cold. Starting off spring as if it were February with temperatures 25-30 degrees F below normal for highs and 15-20 degrees below normal for lows. Will have some recovery later this week, but near normal conditions (+-5 degrees F) don’t appear consistently likely until early next week. Thursday may give us a one day break with mid-50s (normal is around 60 F). So far our warmest day this year was March 3rd (73 F). The Great Plains have been part of the very wild weather pattern impacting much of the mid to upper mid-latitudes this year thanks to a highly oscillating jet stream with periods of very cold and very warm conditions relative to local norms. Much of Europe has gone through the same with very cold Arctic air mass spells, while the parts of the East Coast had record heat in February, followed by multiple cold and heavy snow periods from damaging nor’easters. All while the Arctic roasted in heat waves in this winter (relative to their norms) has significant heat and moisture moved northward, hitting sea ice hard. Here in my locality, we’ve had the roller-coaster ride of going from a a high of 4 to a high of 56 in ten days (January), a high of 22 to a high of 65 in seven days (February; and actually the high was 58 two days before that high of 22…ha!) to our mid-May days in early March (low-70s). Now after the last 5 days of March in the more seasonable 50s to low-60s, we’re spending the first three days of April barely above freezing. Winter was wild and Spring is starting off confusing weather even by spring standards. At least it’s not record breaking cold, it is unusually cold regardless though. Looking forward to the actual warmth of spring again.

What’s “Normal”? A Confusing But Important Concept in Climate Change

One thing I notice with human uncertainty and understanding of climate change is our memories are quite short. We don’t always remember how things have changed in the places we have lived in our relatively short lifetimes on this Earth.

Sometimes perspectives from the past help us out.

You might remember in my previous post I discussed a rather random exchange I witnessed between a Mom and adult daughter in a coffee shop where I live, effectively about how the winter climate has changed in Nebraska over the decades. The daughter says “these wild swings (in temperature) are normal”. And the Mom basically says “Not so fast!”…”I remember when it used to be more consistently cold and snowy all winter long”. Basically back in the day there wouldn’t be low 70s in February.

So what’s “normal?”

It’s a strange concept, if you think about it, but an important one. As a meteorologist (who aren’t climatologists), we use “normal” as a moving target. The previous 30 calendar years as the standard for “normal”. So it’s 2018, so we compare what’s happening today or this week or this month thus far to the previous average for the 1981-2010 time period. During the previous decade, we used 1971-2000, the previous decade before that, 1961-1990, etc. But when your “normal” is shifting with time, it’s under the assumption that the climate of your region is relatively stable with natural variability. But it is not any longer. Anthropogenic climate change being produced by industrial civilization is strongly dominating our planet in timescales of years to decades, which means, moving the “target” to some degree actually masks just show significant global warming is changing the climate of a given area (and of course the planet as a whole).

Without data or communication across generations, the current pace climate change (which is still nearly 170 times faster the past 50 years than the previous 10,000 years) can still go unnoticed by the current living generations of people who haven’t noticed or experienced the weather of the “past climate”. Here are some rather stark examples-

I decided to take a look at climate data from the National Climate Data Center for the city of San Diego. I gathered temperature data from San Diego International Airport for the period 1998-2017 and from the San Diego Weather Bureau (the ancestor to the modern National Weather Service) for the period 1890-1909. The most significant symptom of climate change is the shift of the weather to more extreme conditions.  Extremes which never occurred previously, but also known extremes which become much higher in occurrence. In this case I looked at the occurrence of low temperatures at or below 41 degrees F (5 C) and the occurrence of high temperatures at or above 86 degrees F (30 C). The results were…stunning.

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High temperatures at/above 86 F: 62 (Highest temperature in period: 100 in 1909).

Low temperatures at/below 41 F: 206 

1998-2017-

High temperatures at/above 86 F: 158 (highest temperature in period: 101 in 2012/2016).

Low temperatures at/below 41 F: 28

So what’s normal? If you account for the fact that climate change has been underway since the late 19th century (and before that), occurrences of high temperatures at/above 86 F are running 96 days above normal, while occurrences of low temperatures at/below 41 F are running 178 days below normal. If you were born in the 80s or 90s in San Diego might not even realize your city used to be a lot cooler place. And I do mean A LOT cooler, even if you have actually notice it has warmed more abruptly since you were younger.

I did this same “instant study” for my home city of Seattle some months ago. I don’t have the numbers on me any longer, but it was for shorter time frames (1896-1905) and (2008-2017) looking at high temperatures at or above 90 degrees F. Less than a dozen 90 degree days during the early era vs. nearly *60* in the most recent era, as well as the all-time record high for Seattle of 103 in 2009. Nearly 60 days at or above 90 degrees in just one decade! I don’t remember the exact values for the low temperatures (at or below 32) but there was a notable drop in the number of below freezing temperatures compared to the past. But even going back to my childhood…born in 1984 and a “child of the 90s”. I remember significantly cool, wet periods in the summers, 90 degree temperatures being possible, but rare. When Seattle had its first 100 degree temperature on record in 1994, it was my first experience with triple digit heat in my life and it was absolutely awful. The 2009 heat wave (my last full summer living in the city) was equally roasting with no air conditioning in my parents apartment. In a climate where such heat is rare, many buildings don’t have air conditioning. You use fans and block your (open) windows from the relentless sun with whatever you can. Builders didn’t plan for the summer heat of climate change. And now I look at the 2010s and see more roasting hot summers in the Northwest, raging fires in Western Canada, ashfall in Seattle from those fires. Changing times for my home region.

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Photo of a Canadian fire smoke filled Seattle sky from summer 2017. (National Weather Service – Seattle, WA).

Continuing beyond the data, stories from the past can give us a glimpse into previous climate regimes. Yesterday, I was discussing with my friend and Florida author Vanessa Blakeslee about how climate has changed via a humanities perspective. She discussed with me the mid-1930s novel “Cross Creek” by author Marjorie Kinnan Rawlings. She lived in rural north-central Florida and in the novel, the timing of the summer rains are mentioned and “long, cool winters” are reminisced…temperature and precipitation patterns which Vanessa told me are typically very much different today compared to more than 80 years ago.

So what’s normal? What allows humanity the resources (fertile soil, water availability) to sustain agriculture and feed a population, from which towns and cities and economies can grow and develop. The past 10,000 years of a Holocene epoch has witnessed climate stability which has allowed humanity to know when the rains will come, when the rivers will flood, when the dry seasons happen, when to expect the snows, etc. Variability, yes, the occasional extreme sure. But you KNEW the pattern.

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Projected rise in global temperature of at least 4 degrees C/8 degrees F (relative to mid-20th century) during the 21st century relative to the past 10,000 years.

But now we’re leaving that behind. There’s no “new normal” in the “Anthropocene”, there’s only a continuous and accelerating shift to more extreme conditions until climate change stops. It only stops when the planet is back in energy balance given the amount of energy its greenhouse gasses are forcing it to retain. And given what humanity has already done to the atmosphere and the continuous acceleration of changes in the climate system, our planet still has much more to go through to get to that actual “new normal”. But it will be likely full of catastrophic impacts for humanity and already so for many species.

The sun shines on the middle of the continent while the coasts face the wrath of ocean storms

Quite the day out in weather world, although you wouldn’t know it from looking outside here in the land of the corn. Beautiful day, although still waiting for the leaves to make an appearance. Soon enough, but the sun shines bright overhead. Calming and peaceful for a walk later.

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Outside my favorite coffee shop in Lincoln. 52 degrees F and very light wind. Your normal late March day in all its glory.

After a winter which was tumultuous with big temperature swings (sometimes 50 degrees F within days), it’s nice to have a little stability for some days. Looking near or mildly above normal temperatures the next several days with periods of rain showers. Our winter in this region was less than 0.5 C below normal relative to 1981-2010, but running 0.5-1 C above normal relative to 1881-1910 when factoring the effect of climate change. And temperatures from anthropogenic climate change began rising globally after the mid-1700s, so late-19th century values are still conservative on the changes which have occurred here. People around here were complaining about how cold it was this winter. It could’ve been a lot worse as we had a few 60 and 70 degree temperatures in February mixed with the 10s and 20s for highs in January and February! Just wild.

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Global temps relative to the late-20th century vs. the late-19th century (the latter showing the effect of anthropogenic climate change very obvious). The Arctic is getting “hot” (for the survival of sea ice) fast with major effects on the region and world for further global warming.

Actually reminds me of a story in the coffee shop of a mother and adult daughter discussing this past winter. The daughter saying how “normal” it was to have these huge swings in temperature and crazy weather (snow then short-sleeve weather). Mother saying “Well I remember when I was young, it would be more consistently cold with a lot more snow, not like now”. What’s normal has changed with time in a lot of world, but you wouldn’t know it unless the different generations notice and chit chat about it.

Our chances of snow appear to be over. Never say never, as the East Coast seems to be getting blasted by these cold storms, but when you start seeing these consistent mild conditions finally, it’s usually a sign of the seasonal transition…finally.

I do have some concern over this Spring’s tornado season I must say. La Nina periods in the El Nino Southern Oscillation tend to be known for quite intense tornado outbreaks. Trying to get a science paper reading in about it this week if I can. The Gulf of Mexico waters are running above normal for moisture, the South has been quite warm overall with record warm days and months this winter. And jet stream dynamics continue to be favorable for bringing periodic shear profiles for significant severe weather. The atmosphere put on quite a show this weekend in the Deep South where it is climatologically favorable for tornado activity. Reminds me to prep an emergency kit. We do have a weather radio, but with things like tornadoes and urban flooding, you never know when you will need a little more to get through a few days of darkness and no refrigeration.

While, it’s quiet here, the West and East Coasts are being battered by major winter storms to start Spring. Very strong upper-level trough over the eastern third of the country and another over the Eastern Pacific means the 4th nor’easter of the month in the East and huge atmospheric river event in Southern California. Heavy snow or flooding/mudslides?

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Middle atmosphere wave pattern showing deep trough generating significant coastal storm with snow over the mid-Atlantic/Northeast. Atmospheric river from SW flow over California.
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Strong east coast storm. You can also see how dead quiet it is over the center of country from prominent high pressure overhead.
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Moderate to heavy snow falling over New Jersey and New York City/Long Island.
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Strong West Coast storm impacting California with heavy rain.
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Moderate to heavy rainfall impacting parts of Southern California. Problems with flooding and mudslides/debris flows likely. (radar as of 1 pm PDT).

Good mid-week to all and stay safe in these stormy areas!

–Meteorologist Nick Humphrey

Meteorological Analysis of January 22, 2017 Great Plains/Midwest Blizzard As It Happened

Here is a meteorological analysis I did on Monday of the blizzard which raked much of the Central Plains and upper Midwest from Nebraska and Kansas to Minnesota and Wisconsin with heavy snow and high winds. It was recorded around 11:30 am CST Monday. Those who follow me on my Facebook page (also see my feed on the sidebar) were able to see it right after it was uploaded, but I’m posting it here for those interested in hearing me discuss the event as it happened. Peak snow totals up to a foot and a half resulted in parts of Nebraska, Iowa and Minnesota. Lincoln and surrounding parts of the town only saw 2-3 inches but the totals increased dramatically not far west and north. We got off easy compared to the one foot and greater totals in northeast Nebraska. Winds gusts throughout the region peaked 45-60 mph. You can hear the noise of the high wind through my door in the video.

By the way, my son Bruce makes a guest appearance as he tries to turn off my computer while recording. Haha.

Strong Winter Storm Impacting portions of Plains and Midwest Early Week

A strong winter storm is pushing across the Great Plains tonight. North of the low will experience widespread blizzard conditions and heavy snow. South of the low milder conditions with rain.

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Infrared image, but with surface frontal analysis added, valid at 6 pm CST.

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Parts of far southern Nebraska, into Iowa have a tight gradient between little to no snow vs. heavy snow with high winds. An example…my location in Lincoln, NE where the National Weather Service is calling for 3-4 inches for the day Monday and just added the county under a blizzard warning after 24 hrs ago thinking the area would only receive up to 1 inch with gusty winds and much better travel conditions.

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A difference less than 24 hrs makes. Lincoln now expects up to half a foot of snow (see below) and places expecting 7-8 inches are now expecting 12-18 inches!

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The whole system has been trending southeastward in the models and in reality and so the official forecast has been trended slightly higher and significantly so in places of central and northeastern Nebraska which may get up to a foot with isolated amounts up to 18 inches! The bigger story are winds which may gusts 35-50+ mph across much of the north-central Plains during the night and during the day Monday. This will induce the blizzard conditions, with very low visibilities.

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Conditions will improve across Nebraska and South Dakota by tomorrow evening as the storm shifts northeastward, continuing to impact northern Iowa and southern Minnesota, as well as Wisconsin and upper Michigan with locally heavy snow and gusty winds.

If you’re in an area under blizzard or winter storm warnings, stay off the roads during the worst of the conditions unless absolutely necessary as the roads will be treacherous and visibility poor, particularly outside major cities, where snow can blow around easily. If you have to travel, drive slowly and with care.