WEATHERAmerica Newsletter, Saturday, May 16, 2026; EXTENDED PERIOD FORECAST

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

Heat Ridge Placement Keeps Texas And Dixie Well Above Normal For Temperatures, But Lowers Chances Of Precipitation; Northern, Western Tiers Look Cooler And Stormier)

CIMSS (2)

TropicalTidbits.Com (Dr. Levi Cowan) (3)

NOAA/PMEL

NOAA/CPC

HPRCC/University Of Nebraska (2)

Environment Canada

WeatherBELL (9)

Take a break, if you will, from the seemingly endless barrage of hype and misinformation about El Nino. Concentrate instead on what the start of summer in North America will be like, as the position of jet streams and subtropical highs is far more important, for now at least, then what some numerical model is blathering on about the strength of the +ENSO signal. To settle this matter, we should have a basin-wide high-end moderate El Nino (perhaps bumping to a 1.5 deg C positive hydrothermal anomaly) in the equatorial Pacific Basin. There unquestionably will be arid and torrid weather in the equatorial regions of the Northern Hemisphere. This scenario calls for an immense Saharan heat ridge that occasionally bubbles up into central Europe with massive heatwaves, and a continued building of a Persian heat ridge that sends temperature skyrocketing from southwestern through central Asia. Moisture pooling from the monsoon allied with Phase 2 of the Madden-Julian Oscillation should allow for a normally wet precipitation array across India and Indochina, while the Philippines, Taiwan and Japan must depend on the increase in typhoon formation. Just remember that if the tropical cyclones steer east of the Japanese Archipelago in September, both East Asia and the eastern half of North America will see a cooler turn that might carry on into winter, when models suggest that warm Pacific waters will cool and lead to even more bizarre changes from the Mississippi Valley to the East Coast.

We need to go back and remind ourselves that this is a formative, yet well-defined, El Nino. Classic outcomes suggest a mostly very hot and dry June along and below 40 N Latitude. Marine layer considerations may keep the major California cities out of the hot air, but much of the West will be hot and increasingly dry. Ridging over Texas and the Gulf Coast may pulse/expand into the Midwest and Appalachia, so much of the USA should have warm or hot anomalies next month (as may be the case in the last week of May, such as what the NAEFS ensemble is showing). Development of Mesoscale Convective Systems will shift northward after Memorial Day weekend, concurrent with discrete supercells and QLCS cases from the Missouri Valley into the Great Lakes. It is possible that a weakness at 500MB may allow for higher dewpoints to advect into the south central USA. But the lack of profound dynamics argues against major cumulonimbi development in OK, TX, LA and AR. Any cool intrusions of not will likely stay along and above Interstate 80 across the lower 48 states.

 

Prepared by Meteorologist LARRY COSGROVE on 
Saturday, May 16, 2026 at 11:15 P.M. CT

Disclaimer: 
The previous statements are my opinions only, and should not be construed as definitive fact. Links provided on this newsletter are not affiliated with WEATHERAmerica and the publisher is not responsible for content posted or associated with those sites.

Copyright 2026 by Larry Cosgrove

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