Severe Weather Discussion for Wednesday November 5, 2008.
– Severe thunderstorms are possible Wednesday afternoon and evening
across a large part of Oklahoma.
– High to extreme fire weather is possible Wednesday afternoon for a
few counties in southwest Oklahoma.
12z NAM/ECMWF in decent agreement on Wednesday and the GFS is somewhat
close. The item to note is that the 12z GFS continues to trend
towards the ECMWF. Primary issue for this event is seasonable lack of
moisture or should I say high octane moisture. Surface ridge along
the coast will keep deep layer moisture locked up until Wednesday
morning. As the ridge breaks down some modified moisture return will
occur across the region. Models generally agree on upper 50s to maybe
60F dewpoints in Oklahoma. PW values and 850mb dewpoints are
sufficient for severe thunderstorms. CAPE values do look to remain
limited due to time of year and overall lack of deep layer moisture.
Despite these limitations the incoming system will be quite dynamic
and provide significant lift in the atmosphere. The most likely
scenario for Wednesday afternoon is the development of a strongly
forced and quick moving squall line. Primary threat in this situation
would be damaging winds. As always, cannot rule out supercell
development ahead of the initial line. However, these items are
rather detailed this far out and would prefer to stay at the granular
I don't see this rising to a moderate risk at this point and doubt SPC
will do it on the D3 product. As we get closer, it may be needed
especially if widespread damaging winds become a threat.
Risk area for any part of OK/TX (valid: 11/03 Day 3):
Level 1 – Normal
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