axpz20 knhc 310248
Tropical weather discussion
NWS National Hurricane Center Miami FL
0405 UTC Fri Oct 31 2014
Tropical weather discussion for the eastern Pacific Ocean from
the Equator to 32n...east of 140w. The following information is
based on satellite imagery...weather observations...radar...and
Based on 0000 UTC surface analysis and satellite imagery through
Tropical Storm Vance is the 20th named storm of the tropical
season. Vance is centered near 10.8n 101.3w or about 375
nm...695 km SSW of Acapulco Mexico at 31/0300 UTC moving toward
the west-southwest or 250 degrees at 4 kt. Estimated minimum
central pressure is 1004 mb. Maximum sustained wind speed is 40
kt with gusts to 50 kt. Satellite images show that the center of
the cyclone remains near the SW edge of the deep convection but
in general the convective organization of the storm has improved
with a distinct band to the NE and east of the center. Numerous
moderate to strong convection is noted within 180 nm NE
semicircle. Numerous moderate isolated strong convection is seen
in a band elsewhere from 09n to 12n between 97w and 100w with
scattered moderate isolated strong from 08n to 10n between 100w
and 105w. See latest NHC forecast/ advisory under AWIPS/WMO
headers miatcmep1/wtpz21 knhc for more details.
A Gale Warning will go into effect for the Gulf of Tehuantepec
starting at 01/0000 UTC. Latest scatterometer data provided
observations of 20-30 kt nly winds across the Tehuantepec region
this evening. Winds are forecast to further increase to gale
force by Fri evening. This gap wind event will be associated with
a strong cold front moving across the Gulf of Mexico through
Sat. Expect building seas of 12-16 ft with the strongest winds
by early Sat. This gale force wind event is forecast to persist
through late Sun morning and will likely be the second gale
force event of the cold season 2014-2015. Winds may reach again
minimal gale force Sun night into Monday morning.
...Intertropical convergence zone/monsoon trough...
the monsoon trough extends from 09n78w to 08n90w to 10n97w then
resumes W of T.S. Vance from 09n105w to 08n110w to 13n121w to
09n133w. The ITCZ axis continues from 09n133w to 08n140w.
Clusters of moderate to strong convection are from 08n to 10n
between 84w and 87w. Numerous moderate convection is from 05n to
08n between 85w and 87w.
a cold front is over the NW corner of the area and extends from
30n132w to 26n140w followed by mainly moderate nly winds. The
front is forecast to reach a position from 30n128w to 27n132w to
23n140w by Fri morning while it begins to weaken W of 130w.
Then...front will continue to move se across the forecast waters
through Sat while weakening. A new set of NW swell is expected
to follow the front. A moderate to strong high pres in the wake
of the front will bring an increase in winds and seas across the
west-central waters late Fri into early Sat. Marine guidance
suggest a large area of fresh to strong NE to E winds from 13n
to 22n W of 132w with seas building to 9 ft by early Sat
morning. The front will dissipate by Sat evening with the swell
event spreading across the forecast waters. Expect building seas
of 8-12 ft in NW swell W of a line from 30n119w to 20n130w to
11n134w by Sat evening.
Weak high pressure of 1020 mb is centered se of the front near
27n130w with a ridge axis extending se to near 22n112w. The
pressure gradient between this ridge and lower pressure in the
vicinity of the monsoon trough/ITCZ is supporting moderate to
fresh trade winds across the W waters generally from 10n to
18n W of 120w.
Looking ahead...a Gulf of papagayo gap wind event is expected
early sun as the Gulf of Mexico strong cold front will move into
and across the western Caribbean Sea. Fresh to strong NE to E
winds are expected across the Gulf of papagayo with seas
building to 9 ft.