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
613 AM EDT Sat Apr 21 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 0600 UTC surface analysis and satellite imagery through 
1000 UTC. 

...SPECIAL FEATURES...

Please refer to the METEO-FRANCE High Seas Forecast, that is 
listed on the website: WWW.METEOFRANCE.COM/PREVISIONS-METEO- 
MARINE/BULLETIN/GRANDLARGE/METAREA2. Gale-force winds are 
forecast for the area that is called: MADEIRA. 

...MONSOON TROUGH/ITCZ...
     
The monsoon trough passes through the coastal sections of Sierra
Leone near 07N12W and extends to 03N19W. The ITCZ continues from 
03N19W, crossing the Equator along 27W, to 01S34W, and 01S40W. 
Scattered moderate to strong convection is noted N of the ITCZ
within 30 nm of line from 02N31W to 02N36W to 02N41W, and within 
30 nm of 02N20W. Scattered moderate convection is within 60 nm S
of trough between 16W-20W, and S of the trough within 60 nm of
02N14W.

...DISCUSSION...

GULF OF MEXICO...

A stationary front extends from central Florida out over the far
eastern gulf from the Tampa Bay area to 26N91W, where it
transitions to a warm front to inland Mexico near Corpus Christi.
The front will weaken through this morning, with its remnants 
lifting northward as a warm front this afternoon, ahead of a cold 
front that is expected to reach the Texas coast early on Sunday. 
This front will be preceded by a line of scattered showers and 
thunderstorms. The cold front will reach from the Mississippi 
Delta to the Bay of Campeche on Sunday night, from the Florida Big
Bend to the Yucatan Peninsula on Monday night, and then move 
slowly southeastward on Tuesday, and eventually being southeast of
area by Wednesday evening.

CARIBBEAN SEA...

Upper level cyclonic wind flow, with a trough, spans the entire
area. The trough cuts across central Cuba, toward the Gulf of
Uraba of Colombia. Lingering rainshowers cover the area that 
extends from Nicaragua near 13N northward to the Bahamas near 24N
between 68W/eastern sections of Hispaniola and 88W in parts of 
Central America.

Surface-to-low level cyclonic wind flow is in the SW corner of the
area. rainshowers are possible from 15N southward from 76W
westward.

Other rainshowers are possible from 77W eastward. 24-hour rainfall
totals that are listed for the period that ended at 21/0000 
UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION
TABLES...MIATPTPAN/SXCA01 KNHC...are: 0.17 in Guadeloupe. 

Atlantic high pressure will maintain fresh to locally strong 
trade winds across the south-central Caribbean Sea through early 
Sunday. Strong nocturnal trade winds then are expected to resume 
on Sunday night along the northern coast of the South America. 
Northeast swell, currently across the tropical waters that are to
the east of the Leeward Islands, will subside gradually through 
Saturday evening. A weakening cold front will pass across the 
Yucatan Basin on Tuesday night, and wash out across the
northwestern Caribbean Sea during the middle of next week. 

ATLANTIC OCEAN...

A cold front is analyzed from just to the east of Bermuda 
southwestward to 30N71W and to 29N76W, where it becomes stationary
to Cape Canaveral and to across central Florida to the Gulf of 
Mexico near Tampa Bay. A surface trough is within 150 nm to 210 
nm to the southeast of the cold front. Scattered moderate
convection is within 60 nm of line from 27N71W to 26.5N72W, and 
within 30 nm of line from 27N73W to 27N75W. Similar convection is 
within 60 nm southeast of the trough E of 64W, and east of the
trough within 30 nm of 27N66W. Scattered showers and isolated 
thunderstorms are possible elsewhere from 25N to 28N between
64W-70W.

The cold front portion of the above mentioned front will become 
stationary E to W along 26N by tonight. Remnants of this front 
will lift northward on Sunday. Near gale force southeast wind flow
will develop north of the Bahamas on Monday, to the east of a 
surface low that will shift eastward across the southeastern 
United States. The surface low will move northeastward along the 
Georgia and South Carolina coasts on Tuesday, and drag a cold 
front across the northwest waters during the middle part of next 
week. 

An upper level cyclonic circulation center is near 34N15W, or 
about 300 nm to the north of the Canary Islands. Upper level 
cyclonic wind flow covers the area that is from 22N northward from
30W eastward. A 1006 mb low pressure system is located near 
34N14W, with its associated frontal boundaries extending from the
low to inland northern sections of Africa.

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

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