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Posted: Tue Dec 02, 2003 1:34 am
by JohnShewchuk
Does anyone know of, or is there a standard set of threshold values for DCAPE with respect to Weak, Moderate, or Strong storm potential?

Posted: Tue Dec 02, 2003 6:38 pm
by Tim Vasquez
I just heard back from Richard Thompson (SPC forecaster)...
he had this to say:

"DCAPE values tend to be lower for F2+ tornado environments, and larger
for damaging wind/hail environments, though the differences aren't
terribly large.

DCAPE range subjective interpretation
< 600 J/kg "small"
600-1000 J/kg "modest"
1000-1400 J/kg "large"
> 1400 J/kg "extreme"

In other words, the majority of significant wind events (65 kt or
greater) have been associated with DCAPE > 1000 J/kg, while significant
tornadoes are more common with DCAPE < 800-1000 J/kg. These numbers
are based on a sample of several thousand observed proximity soundings
(within 100 nmi and +/- 3 hrs) for "significant" severe events (Jeff
Craven and Harold Brooks), and a separate sample of several hundred RUC-
2 analysis soundings (within 25 nmi and +/- 30 minutes) for documented
supercells (Thompson, Edwards, etc.)."

Posted: Wed Dec 03, 2003 1:55 am
by JohnShewchuk
Thanks for the information ... just what I needed.