Last week it was a Super-Typhoon; this week it’s a massive outbreak of polar air.
There’s always something going on in the atmosphere, so let’s go Around The World.
The Connection Between Last Week’s Super-Typhoon Nuri And This Week’s Extreme Weather in The Central And Eastern US
Storm lovers might have sprained their necks this week as activity shifted from the tropics to the mid-latitudes in a meteorological nanosecond.
Super-Typhoon Nuri departed the western Pacific and Extreme Weather Event Artichoke sprouted in the north-central United States and is now blossoming like a field of weeds into a potential multi-week deep freeze.
These two storm systems, many thousands of miles apart, are actually connected at the hip.
Wave Patterns In The Jet Stream
As the jet stream circles the globe, there are dips at characteristic intervals. These dips are associated with the weather at the surface.
When Nuri reached latitudes at which the water was too cold to support tropical conversion of latent heat to wind, the spin was still there as well as the low pressure. The storm became extra-tropical, feeding on potential energy of contrasting air masses, and was absorbed by a large low pressure system in the middle-levels of the atmosphere.
Located in the Bering Straits between Russia and Alaska, this low is in just the right place to position the next jet stream dip in the central and eastern US. This dip, increasing in aerial coverage and intensity, has now produced Artichoke.
The cold has spread through the northern and central plains, and will soon expand to cover all of the country east of the Rockies except Florida. The central and southern Rockies will be a buffer for the central intermountain region, but the cold air will spill over the northern Rockies into Washington and Oregon.
Toledo Is Prepared For Snow This Winter
Last winter’s well-above-average snowfalls in the midwest forced municipalities to draw down their reserves of salt. When they tried to re-supply, they found shortages and sky-high prices. Toledo imported salt from Morocco at over $100 per ton, compared to last year’s local price of less than a third of that. Local suppliers couldn’t keep up with this year’s demand and raised prices well over the century mark. If Artichoke is a hint of things to come this winter, Toledo will turn out to have been wise.
How Salt Melts Snow
Water freezes at 32 degrees Fahrenheit. Snow and ice can remain on the ground as long as the temperature is below this number. A mixture of water and salt freezes at lower temperatures, depending on the concentration of salt. Put enough salt on the snow-covered road, and the freezing point of the mixture of salt and snow will fall below the actual temperature — the snow will melt.
El Niño Update
NOAA has reduced its probability forecast for an El Niño this winter from 65% to 58%. The Decoded Science forecast holds steady at 35%. Regardless of whether the Pacific Ocean water temperatures reach the technical threshold for an El Niño (it’s a somewhat complicated formula), all forecasts predict that any El Niño will be weak.
Slightly warmer than normal water temperatures have been the rule for some time in the Pacific, yet none of the weather normally associated with El Niños has materialized. Most notably, California is still bone-dry; El Niño is associated with the Pineapple Express — a warm, wet flow generally from the direction of Hawaii to California.
Europe: A Change Is In The Wind
Temperatures across Europe have been above normal by several degrees in October and early November, but all forecast models have that changing within two weeks, as a southern branch of the jet stream becomes dominant.
The persistence of the jet stream pattern over the Pacific Ocean and United States suggests that the new jet stream configuration may not last.
Tropical Cyclone Season Whimpers To A Close
The tropics have gone quiet. The only activity is a couple of minor disturbances in the eastern Pacific and Bay of Bengal which have very little chance of developing.
The Atlantic and Eastern Pacific hurricane seasons officially close on November 30, while the western Pacific season runs all year.
The Pacific was very active this past summer, with several storms threatening Hawaii, six Super-Typhoons in the Western part of the ocean, and a seemingly unending series of storms emanating from south of Mexico.
The Atlantic had below normal numbers of named storms, but the number of hurricanes and major hurricanes was average.
The Coming Winter In The United States
NOAA’s winter forecast is still predicated on a weak El Niño, which would keep temperatures moderate across most of the United States. However, the pattern that produced last winter’s ice, snow, and cold appears to be unwilling to yield to any different flow. Decoded Science is sticking to its previous forecast of a winter much like last year’s only less so.
El Niño or no; polar vortex or no; global warming — there’s no ‘no’ about that: Whatever the weather does this winter, it will be interesting.
What does it look like where you are?