AXNT20 KNHC 122344
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
644 PM EST Mon Nov 12 2018
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 1800 UTC surface analysis and satellite imagery through
...STORM WARNING in the Gulf of Mexico...
A strong cold front is moving eastward over the Gulf of Mexico,
and at 18Z extends from 30N91W to 24N96W to 23N98W. By Tue
morning, this front will extend from the W Florida Panhandle to
western Bay of Campeche. Winds will quickly increase to gale
force behind the front this evening spread south tonight, with
storm force winds developing offshore of Veracruz Tue morning
through mid afternoon. The front will then reach from near
Apalachee Bay Florida to the northern Yucatan Peninsula early Wed,
and move SE of the Gulf early Thu. Winds and seas will then
gradually decrease through the end of the week. Refer to the High
Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC
for more details.
A tropical wave that is interacting with an upper-level trough
continues to produce a large area of disturbed weather that
extends from near the Leeward Islands northeastward over the
tropical Atlantic for several hundred miles. A surface trough is
analyzed along 59W from 14N-20N. Numerous moderate/isolated
strong convection is seen from 15N-22N between 53W-57W. Scattered
showers and thunderstorms are elsehwere from 14N-24N between 51W-
60W. This system has not become any better organized over the past
24 hours, and environmental conditions may not become as
conducive as previously anticipated. There is a medium chance of
tropical cyclone formation within the next 48 hours. Regardless of
development, this system is forecast to bring locally heavy
rainfall to portions of the Leeward Islands, the Virgin Islands,
and Puerto Rico over the next few days. Refer to the Tropical
Weather Outlook under AWIPS/WMO headers TWOAT/ABNT20 KNHC for more
An Atlantic tropical wave extends its axis along 56W from 12N
southward. Numerous moderate convection is present east of the
wave axis from 07N-12N between 49W-54W.
An Atlantic tropical wave extends its axis along 63W south of
18N. Scattered showers are noted over the northern portion of the
wave affecting the Virgin Islands.
The monsoon trough extends from W Africa near 09N13W to 07N21W,
then transitions to ITCZ from that point to 04N34W to 07N51W.
Numerous moderate/scattered strong convection is occurring within
90 nm of the monsoon trough and ITCZ between 15W-31W. Scattered
showers are noted elsewhere within 120 nm of the monsoon trough
and ITCZ between the coast of Africa and 36W. Broken cloud cover
with isolated or greater shower coverage extends from 02N-15N
between the coast of Africa and 55W.
GULF OF MEXICO...
A 1013 mb surface low is analyzed along the aforementioned cold
front near 29N92W. Numerous moderate with embedded isolated strong
convection is located within 90 nm either side of a line from
31N87W to 29N90W to 25N94W. Scattered showers and thunderstorms
also extend southwestward from there along the cold front.
For more information on the gale and storm force winds over the
Gulf of Mexico tonight through mid-week, see the special features
See the Special Features section for details on the tropical
disturbance located to the east of the northern Leeward Islands. A
tropical wave that has entered the east Caribbean contains
scattered showers. Refer to the Tropical Waves section above for
details. A closed upper-level low is located over the Virgin
Islands. This upper-level low could also be helping to enhance
showers and thunderstorms in the area.
In the far southwest Caribbean, scattered moderate/isolated
strong convection is noted south of 10N between 77W-83W, and over
portions of Panama, due to the East Pacific monsoon trough.
Increasing thunderstorms, strong gusty winds and building seas
accompany a surface trough south of 20N along 59W in association
with the tropical disturbance referred to in the Special Features
Section as well as the trailing tropical wave east of the Lesser
Antilles. Low pressure may develop along the northern portion of
the trough as it shifts W to WNW across or near the NE Caribbean
and adjacent Atlc through Tue, possibly intensifying to a tropical
cyclone. Elsewhere, high pres N of the area will support pulses
of fresh to strong winds across the Windward Passage, over the
adjacent waters of the SW Dominican Republic, and along the coast
of Colombia through Tue. A strong cold front will bring fresh to
strong N winds and seas to 10 ft into the Yucatan Channel and the
NW Caribbean Wed night through Thu night.
A stationary front enters the forecast area just off the southeast
US coast near 32N80W to the Georgia coast near 31N81W to near the
Florida/Georgia border near 31N83W where it becomes a warm front
that continues westward. Also in the area, an E-W surface trough
is analyzed along 28N between 73W and Cape Canaveral Florida.
Satellite imagery and Doppler radar data show scattered showers
and thunderstorms from 28N-32N, west of 77W.
Refer to the Special Features Section for information on the
tropical disturbance located just east of the Leeward Islands.
Surface ridging prevails across the remainder of the basin,
anchored by a 1027 mb high centered near 32N34W.
The front off the southeast US coast will drift north of the area
tonight. The next cold front will move off the southeast US coast
by late Wed, reaching from near 31N72W to the central Bahamas and
central Cuba late Thu night into Fri.
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