Tropical Weather Discussion

- as issued by NHC/TPC -

| home | tools | pleas for help | QHWRN | guide | climatology | archive

- - NHC Marine Graphicast: "Today's Weather Story" - -

- - Click on image to go to NHC webpage in order to view earlier graphicasts - -

Tropical Weather Discussion (NHC/TPC):
NWS National Hurricane Center Miami FL
105 AM EST Tue Jan 21 2020

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 0000 UTC surface analysis and satellite imagery through 
0550 UTC.

...SPECIAL FEATURES...

...ATLANTIC OCEAN GALE WARNING...

The 24-hour forecast, starting at 22/0000 UTC, Tuesday evening, 
consists of: a cold front will be to the east of the Bahamas.
A low pressure center is forecast to develop along the cold 
front. Gale-force N and NE winds, and sea heights ranging from 
10 feet to 17 feet, will develop from 29N northward between 77W 
and 81W. The gale-force winds will develop in the area of the 
pressure gradient, between the low pressure center, and high 
pressure building into the SE U.S.A. Please read the latest HIGH 
SEAS FORECAST: MIAHSFAT2/FZNT02 KNHC, the latest OFFSHORE 
FORECAST: MIAOFFNT3/FZNT23 KNHC, or go to the website 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, from the NWS 
National Hurricane Center, for more details.

...GULF OF MEXICO GALE WARNING...

The Gulf of Mexico gale wind warning will be ending in a few 
hours. the original forecast consisted of NW-to-N gale-force 
winds, and sea heights ranging from 10 feet to 14 feet, from 20N 
southward from 95W westward. Please read the latest HIGH SEAS 
FORECAST: MIAHSFAT2/FZNT02 KNHC, the latest OFFSHORE FORECAST: 
MIAOFFNT4/FZNT24 KNHC, or go to the website 
https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, from the NWS 
National Hurricane Center, for more details.

...CENTRAL ATLANTIC AND NORTHEAST CARIBBEAN LARGE SWELL...

Large northerly swell will continue to affect the Virgin 
Islands, Leeward Islands and northeast Caribbean Sea passages 
through Tuesday. Large surf, dangerous rip currents, and 
possible coastal flooding will affect the Atlantic Ocean-facing 
shores of these islands through tonight. Please read information 
from your local or national meteorological service for more 
specific information on the beach hazards in your area.

...MONSOON TROUGH/ITCZ... 

The monsoon trough passes through the coastal areas of Liberia 
near 05N10W, to 03N22W. The ITCZ continues from 03N22W, to 
02N27W, crossing the Equator along 31W, to 01S38W, and to the 
coast of Brazil near 03S43W. Precipitation: widely scattered to 
scattered moderate and isolated strong from 03N southward 
between 02W and 14W, to the east and southeast of the monsoon 
trough. Isolated moderate to locally strong is within 120 nm to 
the north of the monsoon trough from 20W eastward.

GULF OF MEXICO...

The earlier cold front has moved out of the Gulf of Mexico 
completely. 

A surface trough is in the SW corner of the Gulf of Mexico, 
along the coast of Mexico. Isolated moderate rainshowers are in 
the SW corner of the area.

Strong high pressure has settled into the area. The resulting 
tight pressure gradient is maintaining gale-force northwest to 
north winds near Veracruz, Mexico. These winds will diminish to 
strong speeds late tonight, as the high pressure begins to shift 
eastward. The high pressure will continue to weaken as it shifts 
eastward through Thursday,  in response to a cold front, 
preceded by a trough, that will move across the NW Gulf on 
Thursday. The trough will weaken Thursday night as the cold 
front reaches from south-central Louisiana to the western Gulf 
of Mexico. It will then reach from the western Florida Panhandle 
to the central Gulf and central Bay of Campeche by early Friday 
afternoon, and to just southeast of the area by late on 
Saturday. Mainly moderate to fresh winds are expected behind 
this front.

CARIBBEAN SEA...

An Atlantic Ocean cold front cuts across NW Cuba, into the NW 
corner of the Caribbean Sea, and into the Yucatan Peninsula. 
Precipitation: rainshowers are possible from 13N northward from 
75W westward. 

The GFS model for 250 mb shows upper level anticyclonic wind 
flow with a ridge, that spans the entire area. The GFS model for 
500 mb shows a trough extending from NW Cuba, across Jamaica, to 
the coast of Colombia near 10N76W. The GFS model for 700 mb 
shows a cyclonic circulation center that is about 180 nm to the 
south of Jamaica.

A surface trough reaches the northern sections of Colombia, from 
the eastern Pacific Ocean. Precipitation: multilayered moisture 
and rainshowers are from 12N southward from 76W westward, and in 
parts of Panama and Costa Rica. 

Long-period north swell will continue to result in very large 
seas and hazardous marine conditions, across the Tropical North 
Atlantic, and in the Atlantic Ocean, facing parts of the Lesser 
Antilles and Puerto Rico through Tuesday night, before gradually 
diminishing into mid-week. A NW Caribbean Sea cold front will 
reach from eastern Cuba to the northern coast of Honduras by 
Tuesday evening, bringing strong north winds and higher seas. 

ATLANTIC OCEAN...

A western Atlantic Ocean cold front passes through 32N63W, 
through 29N70W, across Andros Island in the Bahamas, across NW 
Cuba, and into the Yucatan Peninsula of Mexico. Precipitation: 
widely scattered moderate to isolated strong within 75 nm to the 
ESE of the cold front and within 45 nm to the NW of the cold 
front, from 28N northward. Broken to overcast multilayered 
clouds and possible rainshowers are elsewhere within 60 nm on 
either side of the cold front. A surface trough is along 28N74W
29N78W 30N80W.

An area of upper level cyclonic wind flow covers the Atlantic 
Ocean from 17N to 32N between 30W and 46W. The upper level 
cyclonic wind flow is supporting a cold front that passes 
through 32N32W to 25N32W, curving to 16N40W, and 14N46W. The 
front becomes stationary there, and it continues to 18N60W and 
20N68W. Precipitation: widely scattered moderate to isolated 
strong within 100 nm on the western side of the cold front from 
27N northward. Broken to overcast multilayered clouds and 
possible rainshowers are elsewhere within 90 nm on either side 
of the rest of the frontal boundary. Isolated moderate is from 
26N northward between 23W and the cold front.

A dissipating cold front passes through the coastal area of the 
Western Sahara near 26N15W, to 30N24W. No significant deep 
convective precipitation is apparent in satellite imagery.

Large seas, to the east of the southeastern Bahamas, will 
subside gradually through early Tuesday. The current western 
Atlantic Ocean cold front will move across the rest of the 
Bahamas and into eastern Cuba by Tuesday evening. A complex area 
of low pressure is forecast to develop along this front to the 
east of the Bahamas, from Tuesday through Wednesday night. The 
pressure gradient between the low pressure center, and high 
pressure building into the SE U.S.A, will bring strong gale- 
force northerly winds to the north of the Bahamas by Tuesday 
night. The gale-force winds will shift eastward through 
Thursday, and to the northeast of the forecast waters on 
Thursday night. A cold front will move across the far northwest 
waters on Saturday.

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

Back to top | home | tools | pleas for help | QHWRN | guide | climatology | archive