WEATHERAmerica Newsletter, Saturday, March 11, 2023 at 11:40 PM CT; Weather Extremes And Global Satellite Discussion

[Larry Cosgrove]

TODAY'S FUN LINKS:

U.S. Radar Summary

Canada Radar Summary

International Real-Time Lightning Detection Map

Global WindFinder

Canada Water Futures Links

USGS Streamflow

 

WEATHER HAZARDS (During The Next 24 Hours)

 

SEVERE WEATHER OUTLOOK
(potential for tornadoes, damaging winds, and large hail within the next 24 hours)

 

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes)

LA....MS....AL....GA....SC

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes)

N, C CA

 

HEAVY RAINFALL OUTLOOK
(potential for an inch or more total rainfall within the next 24 hours)

 

Isolated Locations In

LA....MS....AL...GA....SC

(QPF 1 - 3")

Scattered Locations In

N, C CA

(QPF 1 - 3")

 

WINTER WEATHER POTENTIAL

(potential for Moderate Icing, Snow 2 - 4" or more, and/or temperatures below 10 deg F)

 

Isolated Locations In

N MN....WI....Upper MI

(Snow; 4 - 12")

Isolated Locations In

E UT....W CO

(Snow: Above 4000 Feet; 4 - 12")

Scattered Locations In

N BC....N AB....N, C SK....MB....NE ND....N MN....N, C ON....NW QC

(Intense Cold)

GLOBAL WEATHER SUMMARY

(a review of important weather features around the world)

 

IODC

ECMWF; METEOBLUE; EUMETSAT

 

Spring is the "cutoff low season". And if an "Out Of Africa'' moisture fetch gets set up (likely), emphasis will shift from heavy snow and stratiform rain to intense convection across the Levant and Persia.

Consider that one of these closed 500MB lows has been pounding Anatolia with thunderstorms. This first in a series of upper cold pools/disturbances will press eastward, perhaps weakening but setting up risks for significant thunder across Turkmenistan and Iran on Tuesday and Wednesday. While thermal profiles are not supportive of snow or sleet in lower elevations, higher elevations may be prone to nocturnal snowfall at midweek. The largest in the sequence of storms aloft, now in the Balkan Peninsula, will probably reach the Middle East into the Indus Valley around March 20 - 22. Since a moisture fetch is already setting up from the Nile Headwaters into the Persian Gulf. My suspicion is that convective precipitation may produce severe weather from the Tigris/Euphrateswatershed to as far east as Afghanistan and Pakistan in the third week of March. And probably beyond.

 

HIMAWARI 8

Kochi University

 

A classic example why you should be very careful in using the Madden-Julian Oscillation as a forecast tool for weather in North America.

Many numerical model projections last week kept screaming "Phase 8" and a dramatic cold wave into the lower 48 states as a result. But you will notice two things from this satellite view: the MJO-related convection is highly scattered and mostly oriented toward the Southern Hemisphere. There is some linkage into the polar westerlies on water vapor imagery. But the impacts are limited, and it now appears that as we end calendar winter and move into spring, potential for cold weather and significant snow (after this new week) will become quite limited. A new cold trough is forming in eastern Siberia and Mongolia, but likely to make little progress against the still-impressive ridge over the northwestern Pacific Ocean and Japanese Archipelago. Notice also that Australia is warming, with just one weak cold front in the eastern portion of that subcontinent.

 

GOES WEST

NOAA/NESDIS

 

If I hear that phrase "atmospheric river" one more time....

A better phrase is "equatorial moisture fetch', which has been around for a much longer time and was not coined to be media-friendly. Clearly visible on the GOES WEST image, this flow of high dewpoints has boosted heavy rainfall and warming in California. With responding snowmelt and higher surface temperatures, flooding has been the result. The warm air will gain latitude across the Intermountain Region in the near term, and emphasis for snow will shift into British Columbia and Alberta. Note the well-defined Gulf of Alaska Low, which is usually associated with mild temperatures in the lower 48 states.

 

GOES EAST

NOAA/NESDIS

 

You can make out a west-to-east projection of the storm track near or just above 40 N Latitude. If the disturbances were further south, you could make a case for more intense cold and snow chances. The system in the Great Plains is most likely to be the heavy snow event in the Northeast (mostly interior) in early week. Warmer values remain in control through the southern third of the U.S., so thunderstorms are the primary concern with this oncoming system in the Dixie states on Sunday.

South America appears to be more active. A frontal structure has reached through Bolivia into southern Brazil, and a second strong cold front is approaching Chile from the southern Pacific Ocean. Diurnal convection on either side of the Amazon River may be enhanced by a series of ITCZ waves approaching from the equatorial Atlantic Ocean.

 

METEOSAT

ECMWF; METEOBLUE; EUMETSAT

 

A slow warming trend is indicated for most of Europe. But the cold air that has enveloped the British Isles and Scandinavia will make a return, of sorts, by the middle of next week. Some of the chill may reach France, Germany, and Poland by Thursday and Friday. But the westerlies appear to be shifting into higher latitudes, so that even the United Kingdom and Norway may see moderation in temperatures and reduced chances for snow. A closed 500MB low forming in the Balkan Peninsula on March 14 could have high impacts on the Middle East as far as thunderstorm activity.

Cyclone Freddy, incredibly, is still intact with respect to a circulation and thunderstorms as it moves through Mozambique. The remnants of the once-dangerous storm will merge with the moisture field over the Congo Basin and Nile Headwaters, and could be drawn further north into the Levant and Persia later next week. The Saharan heat ridge is strong but flat, while the Kalahari subtropical high stifles convection over the western two-thirds of southern Africa.