WEATHERAmerica Newsletter, Saturday, September 16, 2023; Weather Extremes And Global Satellite Discussion


A Few Takeaways from the “State of the Climate in 2022”

The Front Page – 6 September 2023

The just-released annual NOAA/AMS State of the Climate report maps out the complex, interconnected climate phenomena affecting all parts of the globe, and also charts global progress in observing and understanding our climate system.

Bursting Air Bubbles May Play a Key Role in How Glacier Ice Melts, Oregon State Research Suggests

Oregon State University – 7 September 2023

A new study has uncovered a possible clue as to why glaciers that terminate at the sea are retreating at unprecedented rates: the bursting of tiny, pressurized bubbles in underwater ice.

Hurricane Lee Is Charting a New Course in Weather and Could Signal More Monster Storms

The Associated Press – 9 September 2023

The storm left experts astonished at how rapidly it grew into a goliath Category 5 hurricane.

World Can Now Breathe Easier

Washington University in St. Louis – 6 September 2023

While global, population-weighted PM2.5 exposure has decreased in recent years, further air pollution mitigation is still needed, say researchers who quantified changes from 1998 to 2019.

How Fires, Floods, and Hurricanes Create Deadly Pockets of Information Isolation

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Scientific American – 11 September 2023

Telecommunications grids are vulnerable to worsening climate disasters—which highlights the importance of one age-old survival system.

New Research Explains “Atlantification” of the Arctic Ocean

University of Alaska Fairbanks – 31 August 2023

New research by an international team of scientists explains what’s behind a stalled trend in Arctic Ocean sea ice loss since 2007.

Drones Mapping Urban Heat Islands

Weather Underground – 8 September 2023

Satellite data is often used to measure urban heat islands, but drones are becoming an increasingly popular scientific tool.

Heatwaves Hitting Antarctica Too Now

University of Colorado Boulder – 7 September 2023

As discussed in the new State of the Climate report, the planet’s coldest and driest continent experienced both an unprecedented heatwave and extreme precipitation last year.

A First: Category 5 Storms Have Formed in Every Ocean Basin This Year

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The Washington Post – 8 September 2023

A combination of human-caused climate change and El Niño have heated ocean waters to record levels in 2023, setting the stage for this meteorological feat.

Penn State Professor to Lead Field Campaign to Study Climate in Baltimore Area

The Pennsylvania State University – 31 August 2023

Kenneth Davis will spearhead the DOE-funded project to investigate the influence of surface–atmosphere interactions.

North America’s Summer of Wildfire Smoke: 2023 Was Only the Beginning

The Conversation – 1 September 2023

The proliferation of wildfire smoke this year highlights an emerging air quality trend.

Can Conversations Bridge the Climate Divide?

University of Leeds – 7 September 2023

Climate change skeptics and climate activists are being urged to get together to try to find common ground as part of a new study.

WEATHER HAZARDS (During The Next 24 Hours)
(potential for tornadoes, damaging winds, and large hail within the next 24 hours)
ISOLATED Severe Thunderstorms
(Microbursts, Large Hail, Isolated Tornadoes)
E WV….C, E PA….NJ….DE….MD….DC….VA….NC….SC….E GA….E FL Peninsula
ISOLATED Severe Thunderstorms
(Microbursts, Large Hail, Isolated Gustnadoes)
(potential for an inch or more total rainfall within the next 24 hours)
Isolated Locations In
E WV….C, E PA….NJ….DE….MD….DC….VA….NC….SC….E GA….E FL Peninsula
(QPF 1 – 3″)
Isolated Locations In
(QPF 1 – 2″)
Isolated Locations In
S Lower MI….N IN….N IL….SE WI
(QPF 1 – 2″)
(Potential For Temperature To Exceed 95 deg F)
Scattered Locations In
Interior CA….SE OR….NV….AZ….UT….S ID….SW MT….WY….SW SD….NE Panhandle….CO….W KS….OK Panhandle….W TX
Isolated Locations In
FL Peninsula


(a review of important weather features around the world)
It seems like the process takes forever. But fear not, the descending southern branch jet stream and cooler air are slowly suppressing the dwindling Saharan/Persian heat ridge complex.
The persistent subtropical high that has covered a swath from northern Africa through the Middle East/Persia and the Central Asian Republics is on its deathbed, broken into small regional anticyclones that deliver hot and dry air. But repeated incursions of shortwaves in the 500MB flow reduce the extent and power of the anticyclone every day. You can see this impact by looking at the ECMWF forecast panels between now and September 26. The cold pool and active storm track is growing in the European subcontinent, and is a dominant force across the Russian steppes. In time, every piece of energy moving through the jet stream will deliver more thunderstorms and pockets of stratiform rain into the Levant and Iran. By the end of the month, only North Sudan, Yemen and the UAE will still be routinely hot and arid. The locales from Asia Minor through the Tigris/Euphrates watershed all the way to the Indus River Valley will see chances for important rainfall, and mild as opposed to hot temperatures.
The process, as I have said, takes time!
Kochi University
Anyone trying to use the Madden-Julian Oscillation as a forecast tool at this time would come away totally confused. The MJO is incoherent, with convection scattered from eastern India eastward to below Hawaii. There is no linkage with the polar westerlies. Indeed, many numerical models build a prominent heat ridge over mainland China, and show a scattering of shortwaves in a split flow across the Pacific Basin. This is probably a good indication that weather across North America will remain unamplified, with few cold intrusions, over the next two weeks.
Australia and Indonesia continue to show the impacts of El Nino with generally warm and dry conditions (except for a weak cold front over the southwest portion of the subcontinent). There is a stronger polar air mass boundary and storm over the southern island of New Zealand.
If anyone tried to tell you that there was no sign of El Nino affecting North America, just point out that a subtropical moisture feed and southern branch jet stream is setting up across the equatorial regions of the Pacific Basin. Also note the huge gap between the STJ and the prominent Gulf of Alaska Low, which is forecast to deepen and dig through the Intermountain Region, intercepting the lower latitude energy. This is the set-up associated with a cool West vs. warm Central/East alignment for later in the new week, and the likely onset if a Mexican bubble heat ridge that will return Texas and the southern High Plains to an unpleasant hot spell.
When is it wrong to call the Atlantic Basin tropical weather scenario “active” when there are three named systems and a looming ITCZ impulse extant? Now would be the correct answer! Lee is extratropical and ready to leave Nova Scotia, Margot is weak and infiltrated with dry air, and Tropical Depression 15 is diffuse and turning northward, likely to bypass populated areas even if it does intensify. As for the equatorial disturbances, each will be doomed by shearing high level flow and inclusion of dry air from the Sahara Desert.
Oddly, Lee is failing to deliver a cool knockout of warm air across North America. But the polar jet stream is pushed down into then lower latitudes of the U.S., so when the heat ridge in Mexico rebuilds only the south central states will likely be involved. An upper disturbance on Texas that is triggering diurnal convection there will be forced eastward and dissipate.
South America remains largely dry. A minor wave un the eastern Amazon Basin is producing thunderstorms, but most of the continent has followed the winter pattern of low precipitation, clear skies, and above normal temperatures.
The active polar jet stream over the Atlantic Ocean will start to deliver precipitation impacts to much of Europe over the following ten days. The warmer values through the eastern two-thirds of the subcontinent will be replaced by near normal temperatures and increasing precipitation potential (first convective and later stratiform type rains).
Note the erosion of the Saharan heat ridge on its western flank. Most of the model guidance slowly breaks down the once-vast subtropical high, allowing for some moisture to produce minor showers and thunderstorms across northern portions of the African continent. The ITCZ is still active and percolating, producing tropical waves which could, in theory, produce a depression near the Cape Verde Islands that would quickly be turned northward over open waters. The Kalahari ridge complex is very strong and has shut down any rain chances across the southern portions of Africa.

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