[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121805
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
204 PM EDT Wed Jul 12 2017

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 32N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1715 UTC.

...TROPICAL WAVES...

An Atlantic Ocean tropical wave is along 23W/25W from the Cabo
Verde Islands near 15N southward. Convective precipitation:
widely scattered moderate to isolated strong from 06N to 10N
between 20W and 26W.

An Atlantic Ocean tropical wave is along 16N47W 10N44W 05N42W.
Convective precipitation: widely scattered moderate to isolated
strong from 13N southward between 30W and 50W.

An Atlantic Ocean tropical wave is along 58W from 20N southward,
moving westward 10 to 15 knots. Convective precipitation: widely
scattered moderate to isolated strong from 17N to 18N between 60W
and 61W.

A Caribbean Sea tropical wave is along 83W/84W from 20N southward,
moving into eastern sections of Honduras and Nicaragua. Convective
precipitation: widely scattered moderate to isolated strong from
10N to 17N between 80W and 85W, in parts of Honduras and
Nicaragua, and in the coastal waters between 80W and Central
America.

A tropical wave is along 95W/97W, from 20N southward, moving
through southern Mexico, just to the west of the Isthmus of
Tehuantepec of southern Mexico. Convective precipitation:
nothing significant at the moment.

...ITCZ/MONSOON TROUGH...

The Monsoon Trough passes through southern Mauritania near 17N16W,
to 08N23W, 07N32W, and 04N34W. The ITCZ continues from 04N34W to
03N37W and 03N50W. Convective precipitation: scattered moderate to
isolated strong from 07N to 11N between 50W and 62W. Isolated
moderate to locally strong elsewhere from 12N southward from 60W
eastward.

...DISCUSSION...

...THE GULF OF MEXICO...

Upper level anticyclonic wind flow covers Mexico and the coastal
waters from 26N southward, between 96W and 102W.

An upper level cyclonic circulation center is in the Big Bend of
Texas.

An upper level cyclonic circulation center is near 19N89W, in the
Yucatan Peninsula of Mexico. Cyclonic wind flow covers the area
from Guatemala to 25N between the Yucatan Channel and 94W.

Upper level anticyclonic wind flow covers the rest of the Gulf of
Mexico, to the north of the Yucatan Peninsula cyclonic center,
from 93W/94W eastward.

Convective precipitation: isolated moderate to locally strong,
from 27N northward from 93W eastward, and from 22N northward from
95W westward along the coasts of Texas and Mexico.

A surface ridge passes through the Florida Panhandle to 22N96W.

...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL PLATFORM
SITES, THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N
NORTHWARD AND FROM 88W WESTWARD...

LIFR: none.

IFR: none.

MVFR: KVQT.

CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE
U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS: rain and thunder still are possible in the Deep South,
closer to the coast, and near drizzle in Laredo. rain and thunder
are near Kingsville. light rain in Angleton/Lake Jackson. rain and
thunder have ended for the moment in Galveston. rain and thunder
are in Beaumont/Port Arthur. rain and thunder are active in
parts of the Houston metropolitan area and surrounding smaller
communities. LOUISIANA: rain and thunder in Slidell, along the NE
corner of Lake Pontchartrain. light rain in Boothville. rain and
thunder also are just to the north of the SW corner of the area,
more inland. MISSISSIPPI: light rain in Pascagoula. MVFR in parts
of the Hattiesburg metropolitan area. ALABAMA: light rain in parts
of the Mobile metropolitan area. FLORIDA: rain and thunder have
ended for the moment in Crestview. light rain in Destin. rain and
thunder have ended for the moment in the Panama City metropolitan
area. rain and thunder are active in Apalachicola.

...THE CARIBBEAN SEA...

Upper level anticyclonic wind flow covers the Caribbean Sea from
20N southward between 67W and Honduras/Belize.

An upper level cyclonic circulation center is near 19N89W, in the
Yucatan Peninsula of Mexico. Cyclonic wind flow covers the area
from Guatemala to 25N between the Yucatan Channel and 94W.

The monsoon trough is along 08N/09N from 77W westward, beyond
Panama, into the eastern Pacific Ocean. Convective precipitation:
earlier numerous strong from 14N southward between 75W and 80W,
has weakened and dissipated. Convective debris clouds, and
possible lingering rainshowers, are from 14N southward between 75W
and 80W.

24-hour rainfall totals in inches, for the period that ended at
12/1200 UTC, according to the PAN AMERICAN TEMPERATURE AND
PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.58 in St.
Thomas in the Virgin Islands, 0.12 in Nassau in the Bahamas, 0.10
in Freeport in the Bahamas, 0.07 in San Juan in Puerto Rico, 0.02
in Teguciagalpa, and 0.01 in Guadeloupe.

...HISPANIOLA...

Broad upper level cyclonic wind flow is associated with a NW-to-
SE oriented trough. Some rainshowers have developed in the
easternmost part of the island.

SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the
DOMINICAN REPUBLIC: Barahona: VFR. few cumulonimbus clouds. Santo
Domingo: VFR. few cumulonimbus clouds. La Romana: MVFR. ceiling
1800 feet. Punta Cana: VFR. few cumulonimbus clouds. Santiago:
VFR. few cumulonimbus clouds. Puerto Plata: VFR. few cumulonimbus
clouds.

The GFS MODEL forecast for 250 mb shows that broad cyclonic wind
flow will encompass the area during the next 48 hours. Either a
broad trough or a cyclonic circulation center will be present
across the island. The GFS MODEL forecast for 500 mb shows that an
inverted trough will move across the area, spreading cyclonic
wind flow to the island for the first 24 hours of the 48-hour
forecast period. Anticyclonic wind flow will cover Hispaniola
during day two. A ridge will spread westward, from Puerto Rico.
The GFS MODEL forecast for 700 mb shows that an inverted trough
will spread cyclonic wind flow across the area for much of the
next 48 hours. Expect some SE wind flow during the last 6 hours to
12 hours also.

...THE ATLANTIC OCEAN...


A surface trough is along 45W/47W from 20N to 26N. Convective
precipitation: scattered moderate to isolated strong from 24N to
25N between 46W and 47W. rainshowers are possible elsewhere from
17N to 27N between 44W and 50W.

A surface trough is along 69W from 21N to 26N.  Convective
precipitation:
isolated moderate from 18N to 25N between 60W and 71W.

An upper level cyclonic circulation center is 27N60W, about
520 nm to the ENE of the remnant of T.D. FOUR. Convective
precipitation: isolated moderate from 22N northward between
52W and 62W.

A second surface trough is along 77W/78W from Cuba to 30N.
Convective precipitation: isolated moderate to locally strong
from 23N northward between 70W and 80W.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT


...TROPICAL WAVES...

A tropical wave is in the E Atlc with axis extending from 15N20W
to 05N21W, moving W at 5 kt within the last 24 hours. The wave is
in a region of favorable wind shear, however extensive intrusion
of Saharan dry air and dust are hindering deep convection. Shallow
moisture and middle to upper level diffluence support scattered
to isolated showers from 06N to 11N E of 22W.

A tropical wave is in the central Atlc with axis extending from
14N45W to 04N41W, moving W at 20 kt within the last 24 hours. The
wave is in a region of neutral to favorable wind shear, however
extensive intrusion of Saharan dry air and dust are hindering deep
convection. Shallow moisture support isolated showers from 08N to
12N between 40W and 46W.

A tropical wave is just E of the Lesser Antilles with axis
extending from 20N59W to 09N60W, moving W at 15 kt within the
last 24 hours. The wave is in a region of favorable wind shear,
however deep layer dry air hinder deep convection at the time.

A tropical wave is over the central Caribbean Sea with axis
extending from 20N79W to 10N79W, moving W at 15-20 kt within the
last 24 hours. The wave is in a region of mainly unfavorable wind
shear, and CIRA LPW imagery show large patches of dry air in its
environment, which limit the convection to scattered showers from
15N to 18N between 74W and 85W.

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the coast of W Africa near 16N16W
to 08N22W to 05N39W. The ITCZ begins near 05N42W and continues to
06N57W. Aside from the convection associated with the tropical
waves, scattered heavy showers and tstms are from 03N to 08N
between 27W and 37W and from 07N to 12N between 50W and 58W.

...DISCUSSION...

...THE GULF OF MEXICO...

A weak surface ridge continues to dominate the Gulf waters
producing mainly gentle to moderate E-SE winds. This ridge and
wind pattern will persist through Thursday morning. In the NE
Gulf, remnants of a former surface trough, shallow moisture in
the region and middle level diffluence support isolated showers N
of 26N E of 89W. Similar convection is in the W Bay of Campeche
being supported by a tropical wave that moves across southern
Mexico and adjacent EPAC waters. Looking ahead, a surface trough,
associated with the remnants of T.D Four, currently located over
the southern Bahamas, will move across south Florida on Thursday,
and across the E Gulf Thursday night into Friday, reaching the
central Gulf later on Friday. This trough is expected to increase
the likelihood of showers with embedded thunderstorms.

...THE CARIBBEAN SEA...

The main feature in the basin is a tropical wave moving across
the W Caribbean waters, which is supporting scattered to isolated
showers. Another tropical wave is just E of the Lesser Antilles
and is expected to enter the basin later this morning with
possible isolated showers. See the waves section above for further
details. The latest scatterometer pass continue to provide
observations of fresh to strong winds over the south-central
Caribbean S of 14N between 70W and 74W, including the Gulf of
Venezuela. The area of strong trade winds is shrinking slightly as
high pressure north of the region weakens. Heavy showers and
thunderstorms continue over the eastern half of Panama and SW
Caribbean waters between Panama and Colombia S of 11N. This
convection is mainly being supported by the EPAC monsoon trough.
Looking ahead, a stronger tropical wave is forecast to approach
the Windward Islands late Thursday and enter the eastern Caribbean
early on Friday.

...HISPANIOLA...

Available moisture will combined with the local effects to produce
scattered showers and isolated and thunderstorms during the
afternoon and early evening hours today Wednesday and Thursday.
An upper-level low will support these showers, which is forecast
to dissipate afterwards while moving west towards E Cuba.

...THE ATLANTIC OCEAN...

The remnants of T.D. Four continue situated in the SW N Atlc
waters while it further weakens. A 1015 mb low pressure is
associated with it, which is located near 22N71W along with a
surface trough that extends from 25N71W to the low to 20N71W.
Scattered showers and isolated thunderstorms area within 150 nm of
the low center. Model guidance continue to suggest that a trough
associated with the remnants of T.D. Four will move across the
Bahamas through Wednesday night, reaching south Florida on
Thursday. A surface trough extends from 29N73W to 23N79W.
Scattered showers and tstms are from 23N to 28N between 74W and
80W. Otherwise, the Bermuda-Azores high extends a ridge across the
remainder of the forecast region.

For additional information please visit
http://www.hurricanes.gov/marine

$$
MT
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