781
axpz20 knhc 260929
twdep
Tropical weather discussion
NWS TPC/National Hurricane Center Miami FL
1005 UTC Sat Jul 26 2008
Tropical weather discussion for the eastern Pacific Ocean from
the Equator to 32n...east of 140w.
Based on 0600 UTC surface analysis and satellite imagery through
0915 UTC.
...Special feature...
Downgraded Tropical Storm Genevieve centered near 17.1n
119.1w...or about 625 nm...1155 km...west-southwest of Cabo San
Lucas Mexico...at 26/0900 UTC moving W at 12 kt. Maximum
sustained winds have decreased to 60 kt with gusts to 75 kt.
Estimated minimum central pressure is 990 mb. See latest NHC
forecast/advisory under AWIPS/WMO headers miatcmep3/wtpz23 knhc
for more details. The core convection of Genevieve appears to be
weakening and covering a smaller area than six hours ago. Water
vapor imagery indicated that Genevieve was embedded within a
large area of mid to upper level dry air and is forecast to move
over progressively cooler waters. The combination of the two
factors should result in a steady weakening of the cyclone.
...Tropical waves...
Tropical wave along 93w N of 05n moving W 10-12 kt. An upper
level low to the NW of the tropical wave continues to support a
region of upper level diffluence in the vicinity of the wave.
Despite this upper level support convection is limited along the
wave axis itself.
...ITCZ...
ITCZ axis is centered along 08n78w to 10n98w to 09n105w to
11n114w to 09n140w. Scattered moderate isolated strong within
120-150 nm S of the axis between 97w and 112w and N of 03n to
the coast of Panama and E of 80w. Scattered moderate within 60
nm of the axis W of 133w.
...Discussion...
A break in the upper level ridge along 135w is allowing the
remnant mid to upper level moisture of Fausto northward toward a
mid latitude trough approaching the W coast of the conus. The
inverted mid level trough tracking S of Fausto is expected to be
left behind and continue W out of the forecast area. Further E...
Tropical Storm Genevieve is forecast to take a slightly more N
of W track as it encounters the weakness in the ridge to its NW.
The ridge over the SW and Southern Plains is also being
compromised...in this case by the remnant of Dolly tracking
across NW Mexico. Expect the mid level shortwave energy
associated with Dolly to shear out to the north today...with the
northern energy passing N into the New Mexico while the southern
energy tracks W into the Gulf of California. This southern
energy...in conjunction with the shortwave energy currently
triggering the convection along the W central Mexican coast and
a broad area of upper level diffluence will help the cause for
convection over the Gulf of California tonight and tomorrow.
Meanwhile...an upper level low moving across far southern Mexico
should continue wwd into the E Pacific with the aforementioned
tropical wave in Tow on its E side. Look for convection to
favor the area se of the tropical wave near Costa Rica and
Panama for now...in the region of upper level diffluence.
Behind the tropical wave. Winds have increased to over 20 kt
in the vicinity of the Gulf of papagayo as strong NE to E flow
seeps through Central America from the Caribbean behind the
tropical wave.
$$
Cobb
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