WEATHERAmerica Newsletter, Sunday, May 5, 2024; EXTENDED PERIOD FORECAST

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

The Severe Weather Shifts Northward; The Mexican Heat Ridge Will Do So As Well; But When Exactly?

CIMSS (2)

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

NOAA/PMEL

NOAA/CPC

HPRCC/University Of Nebraska (2)

Environment Canada

TropicalTidbits.Com (Dr. Levi Cowan) (5)

ECMWF (3)

Most of the commotion about weather in the media lately has been about La Nina. We are out of the El Nino episode, registering a + .385 deg C deviation in ENSO sector 3.4. That said, there is usually a 2 to 3 month "lag time" in effects on the synoptic scale across the Northern Hemisphere. This is why I urge caution in prediction of possible hurricane development and impacts in the Atlantic Basin. The likely quicker change will be from the high-profile thunderstorm events (and brief cool intrusions) in the USA this spring.

There has been a steady showing of a strong heat ridge over Mexico since mid-April. As we get closer to summer you will see this subtropical high expand and move slowly northward, in time joining with the Sargasso Sea ridge complex. Using the analogs of recent years with a similar ENSO setting and spring temperature pattern (1998, 2011, 2012, and 2023, leaving out the 1973 and 1983 for the colder presence before AGW/climate change set in), I speculate that we will trend far more than the recent mild/warm April as we move through the current month. A key sign that our first hot weather surge will occur: thunderstorms start to develop alng and north of Interstate 80. When it dries out in Texas and Louisiana, for instance, the awful heat we saw last year in the south central states will spread north and eastward, eventually reaching the Canadian border from time to time.

The North American longer term ensemble members make far more sense than the ECMWF weeklies, which seem mired (again) in a bland "mild or cool" pattern from now through June. More than likely, the cP intrusion moving across the lower 48 states in the 11-15 day period will be the last of spring.

 

Prepared by Meteorologist LARRY COSGROVE on 
Sunday, May 5, 2024 at 1:35 A.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 2024 by Larry Cosgrove

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