Tropical Weather Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
AXPZ20 KNHC 240302

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0236 UTC Mon Jul 24 2017

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
meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through
0130 UTC.


The Eastern Pacific region remains very active with three
tropical cyclones: from east to west, Hilary, Irwin and Greg.
Irwin and Hilary are forecast to become hurricanes, and Hilary a
major hurricane. So far in July, five named storms have

Tropical Storm Hilary is centered near 13.6N 103.5W, or about 330
nm SSE of Manzanillo, Mexico at 24/0300 UTC, moving WNW at 8 kt.
Estimated minimum central pressure is 999 mb. Maximum sustained
winds have increased to 60 kt with gusts to 75 kt. Numerous
moderate scattered strong convection are in a band 120 nm W
semicircle of center. Scattered moderate isolated strong
convection are elsewhere from 10N to 16N between 98W and 105W.
Conditions are favorable for significant strengthening during the
next 24 to 48 hours, and Hilary will likely become a hurricane
on Monday, and a major hurricane on Tuesday as it continues on a
WNW track for the next couple of days. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP4 WTPZ24 for
more details.

Tropical Storm Irwin is centered near 14.9N 117.3W, or about 640
nm SW of the southern tip of Baja California at 24/0300 UTC,
moving W at 7 kt with minimum central pressure of 1001 mb.
Maximum sustained winds are 45 kt with gusts to 55 kt. Scattered
moderate isolated strong convection are from 12N to 16N between
113W and 118W. Irwin will remain in relatively close proximity to
Hilary the next few days. Gradual strengthening is expected
during the next 48 hours, and Irwin is forecast to become a
minimal hurricane on Tuesday. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP5 WTPZ25 for
more details.

Tropical Storm Greg is centered near 14.4N 131.4W at 24/0300
UTC, moving W at 10 kt. Estimated minimum central pressure is
1001 mb. Maximum sustained winds are 45 kt with gusts to 55 kt.
Numerous moderate isolated strong convection are noted within 120
nm of the center. Greg is forecast to maintain its intensity for
another 24 hours, followed by gradual weakening due to the dry
air, increasing shear, and cooler sea surface temperatures. Greg
is expected to weaken to a tropical depression on Wednesday, and
to a remnant low by Thursday. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP2 WTPZ22 for
more details.


The monsoon trough is analyzed E of the tropical cyclone activity
from 09N76W to 09N89W to 10N98W. The ITCZ extends from 10N134W
to beyond 07N140W. Scattered moderate and isolated strong
convection are noted from 05N to 10N E of 92W.



Gentle to moderate NW winds off the Baja California peninsula
are expected to continue through mid-week, as high pressure
remains centered N of the area. Seas will remain 4 to 7 ft in a
mix of long period north and southwesterly swell. Gentle
southerly flow will generally prevail in the Gulf of California,
except for moderate southerly flow over the northern Gulf.

Moderate E to SE winds are expected across most of the area
between just west of Tehuantepec and Acapulco through early Mon.
Nocturnal fresh northerly winds are forecast over the Gulf of
Tehuantepec Tuesday through Thursday nights. T.S. Hilary is
expected to impact the offshore waters within 250 nm of the coast
of the Mexican States of Chiapas and Oaxaca through tonight,
then the offshore waters of Guerrero, Michoacan and Jalisco
through Tue. Hilary is forecast to cross south of the
Revillagigedo Islands on Wednesday as a major hurricane.


Across the Gulf of Papagayo, expect fresh winds each night with
the assistance of the nocturnal drainage flow through the week,
occasionally building max seas to near 8 ft in a mix of east wind
waves and long period southwest swell.

Gentle to moderate S to SW winds are expected across the forecast
zones. Long period cross-equatorial SW swell creating 5-7 ft
seas will continue to propagate into the forecast waters through
mid week. Another set of cross-equatorial long period SW swell of
6 to 9 ft will reach the waters between Ecuador and the
Galapagos Islands late Wednesday, and the coast of Central
America on Thursday.


High pressure is located north of area with a ridge axis that extends
across the forecast waters north of 20N. The pressure gradient
between this system and an active zone of tropical cyclones between
12N and 20N will maintain fresh N to NE winds mainly west of
125W through mid-week. Seas of 8 to 10 ft associated with T.S.
Greg are already propagating across the waters N of 20N W of
130W. Northerly swell in the form of 7-8 ft seas will propagate S
of 32N between 125W and 135W the next two days. By Thursday
night, cross equatorial southwesterly swell of 8 to 9 ft will
spread over the waters south of 10N and east of 110W, persisting
into next weekend.

Latto is the U.S. government's official web portal to all federal, state and local government web resources and services.