WEATHERAmerica Newsletter, Saturday, August 24, 2024; EXTENDED PERIOD FORECAST

[Larry Cosgrove]

EXTENDED PERIOD FORECAST

(Between Day 11 And Day 15)

 

The "Quiet" Hurricane Season Will Awake. And So Will The Polar Jet Stream Shortwaves!

CIMSS (3)

WMO/CMA

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

NOAA/PMEL

NOAA/CPC

IRI/Columbia University

HPRCC/University Of Nebraska (2)

Environment Canada

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

ECMWF (3)

NOAA/CPC

Many of you may have been lulled into thinking that the 2024 hurricane season was over. A rude surprise awaits, however, since the Saharan Air Layer is diminishing, the hemispheric conjoined heat ridge complex is starting to break apart, the ITCZ in Africa is flaring big time, and the polar westerlies are starting to inject cyclonic energy and greater amounts of cooler (not cold) values into lower latitudes. The La Nina episode is likely to top off at just above the moderate designation (-1.0 deg C below normal in ENSO sector 3.4), while the Gulf of Mexico and much of the open Atlantic Ocean is very warm (at least 79 deg F with only minor areas of upwelling. This is not, and never was meant to be, a "Super La Nina with record hurricanes". One-parameter forecasting has no place in a business where fear can cause those living in the subtropical zones and affected coastlines to lose confidence in weather prediction at critical times. I will hold to my original 18 named storms, 10 hurricanes, and 6 major cyclones seasonal call.

We should see a substantial, or more, storm threat in the Gulf Coast in the 11-15 and/or 16-20 day time frame. The ECMWF panels suggest an East Coast event, while the North American ensemble platforms (GFS, GGEM, CFS) series are suggesting Louisiana as a probable danger zone for a tropical cyclone strike. Again, with little shear in a 500MB weakness, very warm sea surface temperatures and added energy from a descending trough and frontal structure, the post-landfall track scenarios could produce very high rainfall rates and severe weather in Dixie, Appalachia and the Northeast in the longer term. The split between the Sonoran and Bermudan heat ridges might allow for a hot West/cool Central/warm, humid East alignment. The analog depictions agree with that scenario for September, and I suspect October will be similar, but with a greater threat zone for a hurricane along the Eastern Seaboard later in the month.

One more thing that needs to be pointed out: I am beginning to suspect that our later autumn and winter time frames will resemble 2007-2008 in some respects. The CanSIPS outlines through February make sense when viewed against a weak/moderate -ENSO signal. Be sure to check in on the OND period outlines, which may just breathe some life into those hoping for a more seasonal outcome. And might possibly silence, for a while at least, those who insist that climate change (which is real) means the right to forecast unrelenting doom and exaggerated outcomes. 

 

Prepared by Meteorologist LARRY COSGROVE on 
Saturday, August 24, 2024 at 11:30 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 2024 by Larry Cosgrove

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