AXPZ20 KNHC 220943
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Sat Jul 22 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
Based on 0600 UTC surface analysis and satellite imagery through
Tropical Storm Greg is centered near 15.2N 123.1W, moving W at
11 kt. Estimated minimum central pressure is 1001 mb. Maximum
sustained winds are 45 kt with gusts to 55 kt. Satellite imagery
shows the low level center has moved back under the convective
cirrus canopy. Scattered moderate to strong convection is noted
within 120 nm north of the center. Greg is forecast to intensify
only slightly during the next 48 to 72 hours. See the latest NHC
forecast/advisory under AWIPS/WMO headers MIATCMEP2 WTPZ22 for
Tropical Depression Nine-E is centered about 480 nm SSE of
Acapulco Mexico near 9.6N 96.6W, moving WNW at 11 kt. Estimated
minimum central pressure is 1006 mb. Maximum sustained winds are
30 kt with gusts to 40 kt. Scattered moderate to strong
convection is observed in bands within 150 nm NW of the center.
Conditions are favorable for significant strengthening during
the next 24 to 48 hours, and it is forecast to become a tropical
storm later today, intensifying to a hurricane by early Monday.
See the latest NHC forecast/advisory under AWIPS/WMO headers
MIATCMEP4 WTPZ24 for more details.
A 1007 mb surface low continues near 14N112W in association with
a tropical wave along 112W. Scattered moderate to strong
convection is within 120 nm SW of the low due to the presence of
persistent northeasterly shear. Environmental conditions are
conducive for a tropical depression to form during the next
couple of days, before upper-level winds become unfavorable for
development. This system is forecast to move westward to west-
northwestward at around 10 kt through early next week.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough is ill-defined in the Eastern Pacific due to
the presence of numerous lows and tropical cyclones. The ITCZ
extends westward from a 1011 mb low near 11N127W to 09N140W.
Except noted with the tropical systems decribed above, minimal
convection is associated with the trough axis.
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Gentle to moderate NW winds off the Baja California peninsula
are expected to continue through the weekend. Seas will remain 5
to 7 ft in a mix of long period north and southwesterly swell.
Gentle southerly flow will persist in the Gulf of California,
except for moderate southerly flow over the northern Gulf.
Fresh northerly gap winds are expected this morning in response
to developing T.D. Nine-E. Seas will build to 7-8 ft with an
additional component of longer period southwest swell.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
In the Gulf of Papagayo, moderate to fresh offshore winds will
pulse to fresh each night with nocturnal drainage flow through
the week, occasionally building max seas to 8 ft in a mix of
east swell and longer period southwest swell.
Gentle to moderate southerly winds are expected south of the
monsoon trough axis. Long period cross-equatorial southerly
swell and 6-7 ft seas will continue to propagate into the waters
reaching the coast of Central America through the day. Another
pulse of large southerly swell will move into the region today
and raise seas to 6-8 ft through tonight.
REMAINDER OF THE AREA...
The remnant low of T.D. 8-E is analyzed near 11N127W, with fresh
cyclonic winds within 90 nm SE of the center. The weak low will
dissipate by tonight.
The pressure gradient between high pressure north of the area
and an active zone of tropical systems between 10N and 16N will
maintain fresh trade winds and 6-7 ft seas north of 20N the next
several days. Northerly swell in the form of 7-8 ft seas will
propagate S of 32N between 125W and 135W the next two days.