Tropical Weather Discussion

- as issued by NHC/TPC -

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Tropical Weather Discussion (NHC/TPC):
NWS National Hurricane Center Miami FL
433 AM EST Fri Dec 15 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 0600 UTC surface analysis and satellite imagery through 
0930 UTC.

...SPECIAL FEATURES...

...Gale Warning Gulf of Mexico...

As of 0600 UTC a cold front extends from southern Alabama SW to SE
Louisiana to NE Mexico near 24N97W. Northerly fresh to strong winds
are behind the front and will rapidly increase to near-gale force
through sunrise today when minimal gale-force winds are expected 
to develop offshore of Mexico. Seas will build to 8 ft in the area
with the highest winds. These conditions are forecast to diminish
by sunrise on Saturday. See the latest NHC High Seas Forecast 
under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details.

...Caribbean Gale Warning...

Strong high pressure will build north of the Caribbean during the 
evening today resulting in a tight pressure gradient in the south
central basin where trades will increase to fresh to strong. A 
strong pressure gradient will persist during the weekend allowing
for the development of gale-force winds northwest of the 
Colombian coast starting tonight through early Monday. Seas will 
build to 13 ft in this area. See the latest NHC High Seas Forecast
under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. 

...ITCZ/MONSOON TROUGH...

The monsoon trough extends from the west coast of Africa near
06N11W to 05N16W where the ITCZ continues along 05N30W to 04N41W
to 0N50W. Scattered moderate convection is observed from 01N-08N 
between 08W and 36W.

...DISCUSSION...

GULF OF MEXICO...

Weak surface ridging prevails across the SE Gulf ahead of a cold
front that at 0600 UTC extends from southern Alabama SW to SE
Louisiana to NE Mexico near 24N97W. Northerly fresh to strong winds
are behind the front and will rapidly increase to near-gale force
through sunrise today when minimal gale-force winds are expected 
to develop offshore of Mexico. Looking ahead, the cold front will
reach from the Florida Big Bend area in the northeast Gulf to 
near Tampico Mexico tonight. The front will stall from Tampa to 
the Bay of Campeche on Saturday before lifting back to the 
northwest through Sunday. Scattered showers are in the NW Gulf  
continuing through tonight. See the Special Features section for 
further details.

CARIBBEAN SEA...

Shallow moisture associated with the remnants of a former
stationary front support isolated showers over the NW Caribbean.
In the SW basin, a surface trough extends from 18N80W to 09N81W 
supporting similar shower activity W of 80W. Middle to Upper 
level ridging and dry air subsidence support stable conditions 
elsewhere. Strong high pressure will build north of the Caribbean 
this evening resulting in a tight pressure gradient in the south 
central basin. This scenario will continue through the weekend 
allowing for the development of gale-force winds northwest of the 
Colombian coast starting tonight through early Monday. See the 
Special Features section for further details. 

...HISPANIOLA...

Cloudiness prevail mainly over SW Dominican Republic due to the 
proximity of a nearly stationary trough in the SW N Atlc extending
to eastern Cuba. Isolated showers are possible mainly over higher
terrain through later this morning. Then, moisture will diminish 
as the trough continues to weaken.

ATLANTIC OCEAN...

Strong surface high pressure anchored south of the Azores extends
a ridge axis into SW N Atlc waters as well as the central and
eastern Atlc. A weakness in the ridge, remnant of a former 
stationary front, is analyzed as a surface trough from 30N54W SW 
to the southern Bahamas to eastern Cuba. Isolated showers are 
within 120 nm either side of this boundary. A cold front will move
off the northeast Florida coast this evening, reach from Bermuda 
to south Florida Saturday, then will stall and gradually dissipate
along 25N through early next week as high pressure from the 
southeast United States builds eastward across the area.

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

$$
Graphical representation of waves, etc. on this image (NCEP/OPC) [more].
Various tropical satellite imagery available here

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