WEATHERAmerica Newsletter, Saturday, May 4, 2024; WEATHER EXTREMES And GLOBAL SATELLITE IMAGERY

[Larry Cosgrove]

WEATHER HAZARDS (During The Next 24 Hours)

 

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

 

Some Thunderstorms May APPROACH Severe Limits

C CA....NV....NW AZ....UT....ID....W MT....W WY

ISOLATED Severe Thunderstorms

(Microbursts, Large Hail, Isolated Tornadoes) (MCV)

C, E TX....C, E OK....AR....LA

Some Thunderstorms May APPROACH Severe Limits

SC....NC....VA....DC....MD....DE....PA....NJ....S NY....CT....RI....MA

 

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

 

Isolated Locations In

C CA....NV....NW AZ....UT....ID....W MT....W WY

(QPF 1 - 3")

Scattered Locations In

C, E TX....C, E OK....AR....LA

(QPF 1 - 6")

Isolated Locations In

SC....NC....VA....DC....MD....DE....PA....NJ....NY....CT....RI....MA...NH....VT....QC

(QPF 1 - 3")

 

EXCESSIVE HEAT RISK

(Potential For Temperature To Exceed 95 deg F)

 

Isolated Locations In

W TX....NM....C, E NM....SE WY

GLOBAL WEATHER SUMMARY

(a review of important weather features around the world)

 

IODC

ECMWF; METEOBLUE; EUMETSAT

 

The "Big Bite" of severe heat season advances!

If you review the various surface temperature maps across the Middle East and South Asia, there appears to be a curved line of extreme heat stretching from northeastern Africa into Saudi Arabia, Persia and India. In a time sequence through May 14, the hottest temperatures advance ever so slowly northward. My estimation is that the "Arc of Fire" will progress as far as a cluster from Greece and Turkey across northern Iran and Pakistan, with occasional expansion into the Central Asian Republics. This formula sounds like many past years, except that the current May scenario has abundant and excessive rainfall out ahead of the cTw+mTw air mass. Severe weather and flooding rains will be common from eastern Asia Minor through much of Iraq into the Caucasus and northern/western Iran. When that moisture comes to a close in the third week of this month, get set for perhaps a three month period across the Levant into far western Pakistan of intense heat. The summer monsoon should be generous across the Indian subcontinent (even into Afghanistan and far southeastern Persia). But the heat ridge from hell is back, and likely to be an unwanted guest until the first or second week of September.

 

HIMAWARI 8

METEOBLUE; Kochi University

 

Are we witnessing the end of the spring storm sequence that stretches back into Tibet? Possibly, as that impulse is not followed by other closed lows aloft from the Central Asian Republics. But there is an impressive area of vorticity and cold air aloft, basically a mirror of the system emerging off of the Japanese Archipelago. That could mean more chances for severe weather and excessive rainfall in eastern China in the near term, and I suspect that this feature is depicted by the model ensemble packages over California in two weeks or so.

There are clusters of thunderstorms associated with the Madden-Julian Oscillation, which is evenly spread out along the Equator from southwest of Mexico into Indonesia. No signs of tropical cyclone formation in this theater as of yet. Note the relatively clear appearance on satellite over Australia and New Zealand, with convection along the southwest and southeastern corners of the subcontinent.

 

GOES WEST

NOAA/NESDIS

 

There are several disturbances in the eastern Pacific Ocean ready to target the western half of North America. A vigorous subtropical jet stream is also poised to strike northwestern Mexico. Note the strength of vorticity and cold air aloft with these systems, all of which are likely to dig through the Pacific Northwest and Intermountain Region before recurving through the Great Plains into the St. Lawrence Valley. High elevations snows, convective showers with hail, and chilly nocturnal temperatures are likely during the next two weeks in the West from the ongoing storm sequence.

 

GOES EAST

NOAA/NESDIS

 

North America is in a progressive, storm-laden pattern. One system brings heavy rain and thunderstorms to the eastern third of continent, while smaller impulses like the one in New Mexico and Texas are set to trigger flooding rains and tornadoes. This active set-up will almost surely continue through the second week of May. 

An ongoing flooding rain/severe weather situation continues from northern Argentina into southernmost Brazil. The thermal boundary separates much colder air associated with a deep vortex southwest of Tierra Del Fuego and a hot/humid regime covering the northern two-thirds of the continent. Note also the ITCZ wave in the western Atlantic Ocean.

 

METEOSAT

ECMWF; METEOBLUE; EUMETSAT

 

Progression of polar jet stream disturbances continues unabated across northern Europe, with chilly temperatures occasionally seen across the British Isles and Scandinavia. In an often-convective environment, the southern half of the subcontinent is seeing warmer than normal values and sometimes strong/severe thunderstorms that eventually slow and turn southeastward into the Balkan Peninsula, Black Sea and Anatolia.

I am watching Africa closely to see the evolution of the ITCZ as it will relate to the summer/fall tropical cyclone season. One large MCS is moving through the Nile Headwaters, including the remnants of Hidaya in Kenya. Most of the northern third of the continent is under a stronger Saharan heat ridge, while the Kalahari subtropical high is in firm control below the Congo Basin with fair and hot temperatures.