After the ultimate winter storm, the ultimate cold wave? Well, why not? After all, it would be just too disappointing for the Great Christmas Blizzard of 2045 to come in and then that’s it for the truly extreme weather. A second act where the arctic air reloads and pours back in stronger than ever just in time for New Year’s Day 2046 would be the perfect bookend.
And even realistic, considering the setup: the storm, which sports a record low pressure below 900 millibars, becomes a cut-off low as the jet stream pattern changes, a trough digging in along the west coast, bringing a simultaneous strong winter storm to southern California (including brief blizzard conditions right down to the beach…), with the main flow of the jet stream well into Canada, northward of the eastern United States. That would normally be associated with warmer weather, but there’s the cut-off low, which is massive, and was already in a pool of deep arctic air to begin with: all-time record lows fall across much of the United States as the storm passes.
So the record cold sticks around for a while, but as the days tick by after Christmas the storm starts to dissipate, and temperatures warm, gradually warming out of record low territory, but still very cold compared to normal…just in time for the trough to pass away from western North America, and be replaced with a ridge, courtesy of a blocking high intensifying in the North Pacific. Combined with the Greenland/Newfoundland block also being in place, this pushes a fresh mass of arctic air southward into eastern North America.
Despite the massive outpouring that already took place, the pattern in the far north is such that there’s plenty more where that came from. Northern Canada tends to be colder than normal during La Niña events, and this may hold true even in this season’s La Niña del Diablo (so named because it’s an unprecedented western-Pacific-based ENSO event…the fact it’s also the strongest La Niña on record helps too). The one to two weeks of respite from being forced southward deepens the degree of cold present in Canada, effectively reloading for a new arctic outbreak.
Arctic Super Outbreak?
When it does escape its boreal confines, the onset will be dramatic, coming in the form of a strong cold front screaming southward at rapid speed, the temperature gradient sharp: very cold air ahead of the front, but air cold enough to smash all-time record lows right behind the front, draped across most of North America: from the Rockies to New England.
Along the front, a band of snow, with so much convective instability as to turn it into a squall line of thunderstorms, forming a derecho stretching from the Rockies to New England, screaming from southern Canada clear through the entire United States. Towering cumulonimbus clouds will announce the cold front’s arrival, the thunder and hurricane-force gusts accompanied not by rain but by snow: temperatures even ahead of the front, even in the South, are too cold for it to be rain. It helps too that the derecho runs behind the cold front proper, so even once it reaches Florida the derecho may be snow-wrapped, not rain-wrapped.
Copious ocean-effect snows will be triggered after frontal passage, with Florida once again pummeled.
Unlike the last system, where the cold air effectively wrapped around the low in counter-clockwise fashion eastward from South Florida to the Bahamas, largely sparing Cuba, this system will sweep southward unobstructed, clearing the Gulf of Mexico, the blue norther making its way past the Greater Antilles and the Yucatan before slowing and weakening.
Obviously the warm waters of the Gulf of Mexico (well, southward of the north shore, which is already starting to freeze over) and the Caribbean Sea will moderate the arctic air, but all-time record lows will fall across the region. Even south of the Tropic of Cancer temperatures might not be much above freezing.
Arctic Lows…in the Tropics
Amid that unprecedented pool of (at the upper levels) more or less unmoderated arctic air over very warm waters, shallow waters next to peninsulas and islands, conditions may become conducive to the formation of “polar lows”. They’re most common in the Arctic, hence the name, but they also occur as far south as the Sea of Japan in the winter. Polar lows are essentially the Arctic’s counterpart to tropical storms and hurricanes: they’re cyclones consisting of convective squalls, they form over warmer waters, they lose strength once they hit land, they’re relatively small (usually under 600 miles long), and they even have eyes in many cases. They’re unpredictable little tempests, and seldom last for more than a few days. The primary difference from tropical cyclones is that they’re cold-core rather than warm-core; they thrive not with heat per se, but rather with temperature differences.
The exact conditions that lead to their formation are complex…and poorly studied! But in general I’d say if any sort of setup would lead to polar lows in the Gulf of Mexico and the Atlantic, it’d be this one: deep record-cold air straight from the Arctic over waters that are still very warm, with the Gulf Stream some of the warmest in the world at such latitudes in fact!
So over the New Year cold wave, conditions on the backside of the front, where ocean-effect snow bands are cranking up in high gear, become conducive to polar cyclogenesis, and off the coast of Florida the pressure starts to drop, the winds shift, and those ocean-effect bands start to curve in a spiral. The temperature gradient at work is so extreme that although the precipitation over South Florida falls primarily as snow (it’s cold enough even there), over the Bahamas it’s a very cold raw rain…until the low strengthens, and the intense bands near the center of the storm start to pull down cold air from the upper levels, cooling and moistening the cold dry air near the surface enough to reach the freezing point, changing the precipitation over to snow.
This patch of snowy weather will move along with the storm’s center as it expands and strengthens, drifting southeastward through the Bahamas, delivering heavy snow squalls and possibly even blizzard conditions to parts of the Bahamas, including the islands south of the Tropic of Cancer. Even the Turks and Caicos Islands could receive heavy snow, along with parts of Cuba and possibly even Haiti. As the storm expands and strengthens, convective bands and isolated squalls could deliver heavy snow and even blizzard conditions to the high elevations of Jamaica, Hispaniola, and Puerto Rico before dissipating, perhaps as a result of the storm’s center making landfall in the high mountains of Hispaniola.
Another polar low forms further north, off the Outer Banks of North Carolina, and drifts southward, delivering snowbands from Georgia to Virginia, before rocketing northward, stalling out over Nantucket and delivering heavy snow squalls to places like New York before curving inland and dissipating over the Berkshires.
Around the same time, a third circulation forms in the shallow warm waters west of the Yucatan, delivering snow there in the intense bands similar to the Caribbean storm, making landfall at, creepily enough, Chicxulub, before rapidly dissipating over land. At considerably under the 20th parallel north, this storm may well deliver the most southerly snows of the entire event…and indeed the lowest-latitude snowfall ever recorded at sea level (nearby Tampico, at 22 degrees north, currently holds the record).
I’m toying with the idea of yet another circulation forming in the wake of this off the west coast of Florida, feeding on the Gulf loop current amid the arctic air, making landfall perhaps somewhere in the Keys before dissipating.
Needless to say all these lows will have eye-like features, and perhaps even hurricane-force winds; Caribbean denizens might remember these polar lows in the tropics as a “white hurricane”. Subzero weather extends a fair ways into Florida and deep into northern Mexico, marking the apex of the historic event.
After the initial push, however, the arctic outbreak has exhausted itself. The front itself will continue to race down into the Caribbean Sea, perhaps even crossing it and reaching South America. It might not be totally crazy to imagine it reaching the equator, but long before then even this monster cold wave will have lost its bite; Aruba, Panama City, and Medellin might be cooler than usual, but conditions aren’t ripe for even all-time record lows, let alone the record-smashing numbers Florida and the northern Caribbean are seeing in this scenario.
Aftermath
It would certainly be a crescendo signaling the end of the hurricane season: As a rule of thumb hurricane activity in the Gulf of Mexico ceases after the first cold front of the season clears the basin, and this would likely hold true for the Caribbean Sea as well. So the Christmas hurricane, which transformed into the blizzard a la Superstorm Sandy, may well be the last tropical storm of the 2045 season.
After this profusion of polar lows during the deepest part of the cold wave, temperatures warm, quickly reverting to normal in the tropics, but in the interior of the United States they’ll remain well below normal, though without the all-time record cold of the Christmastide returning again for the rest of the season. From coast to coast temperatures remain consistently cold compared to normal, nor’easter after nor’easter pummeling the eastern seaboard with blizzard conditions. A broad swath of the eastern United States will have a record strong winter in terms of snowfall; an even broader swath of the United States will experience its coldest winter on record. The warmups in between pulses of cold air typically seen in even a severe winter will be weak or even nonexistent in the 2045-46 season.
Iced-in New Orleans will see liquid waters flowing again quickly after the New Year cold wave ebbs, but it’ll be months still before Niagara Falls thaws…or even New York Harbor.
Incorporating the Weather into Georgia’s Story
Brutal weather, but perhaps a good backdrop for my main character Georgia Roadhouse to fly over to one of those Caribbean islands to experience weather history as it’s being made. For bonus gothic points, I’m thinking she finds an old treasure chest, unearthed courtesy of a direct hit from a Category 5 hurricane earlier that season that scoured it out, while she trudges through slushy snowpack and a snowglobe of wet snowflakes on a beach studded with palm trees, said treasure chest being a time capsule of sorts, containing documents proving Ephraim was who he said he was: a rare books smuggler during the Revolutionary War who operated on a route from Barbados to the Shenandoah, perishing in the Great Hurricane of 1780.
Naturally copious coins will be in there, along with Ephraim’s diary, and jewelry intended for his beloved…which means Georgia, of course (not even death can stop one from finding a soul mate in this story it seems). Rare books will also be in there which Ephraim treasured, including an otherwise lost manuscript from an obscure aristocratic linguistics scholar who made a comprehensive study of the Crimean Gothic language in the late 18th century. Thought to be the last surviving East Germanic language, very little information exists today, despite its existence into relatively recent times, so such a manuscript would be a very interesting find. Georgia’s enough of a nerdy wordsmith to know the significance of it, so she lets scholars have a look at it as soon as she returns to Virginia with it.
For bonus points, Ephraim may have had two copies: one for himself, and another he tracked down for Thomas Jefferson, after he expressed interest in getting one during one of their clandestine meetings at Ephraim’s hole-in-the-wall library home in the Shenandoah. Unfortunately for both men, Ephraim took delivery of the second copy at his usual jumping-off point at Barbados, and set sail…right before he was killed and the ship sunk by the Great Hurricane of 1780.
It’s a nice touch, I think: because of course the key to Crimean Gothic would be in some treasure chest buried in the Caribbean.
Conclusion
All told, I really like these ideas. I think they add a bit more depth and dimension to the story I have in mind, and they are oh so delightful even just on their own. Who would have thought that the addition of a cold wave and a stray inspiration about polar lows could do so much? 😀