000
AXNT20 KNHC 180604
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST MON FEB 18 2013

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 
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE E TROPICAL 
ATLC THROUGH SIERRA LEONE TO 03N19W WHERE THE ITCZ CONTINUES TO 
EQ25W 1N34W EQ40W TO 1S45W. SMALL CLUSTERS OF MODERATE/ISOLATED 
STRONG CONVECTION ARE WITHIN 130 NM NORTH AND SOUTH OF THE 
MONSOON TROUGH AXIS. SIMILAR CONVECTION IS WITHIN 150 NM NORTH 
OF THE ITCZ AXIS BETWEEN 20W AND 34W. SCATTERED MODERATE 
CONVECTION IS WITHIN 130 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 
35W AND 43W. 

...DISCUSSION...

GULF OF MEXICO...
A 1029 MB HIGH PRES LOCATED OVER NORTHERN FLORIDA NEAR 30N82W IS 
PROVIDING ANTICYCLONIC WIND IN THE RANGE OF 20-25 KT WEST OF 90W 
AND OF 5-15 KT EAST OF 90W. STRONG SOUTHEASTERLY WIND FLOW IS 
BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS ALONG THE COAST 
OF MEXICO TO THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. 
OVERCAST SKIES WITH POSSIBLE ISOLATED SHOWERS EXTEND 
APPROXIMATELY 170 NM OFF THE WEST GULF COASTLINE. IN THE UPPER 
LEVEL WESTERLY FLOW MOVES OVER THE WHOLE BASIN AND DRY AIR ALOFT 
SUPPORTS FAIR WEATHER OVER THE REMAINDER OF THE GULF. RETURN 
FLOW WILL CONTINUE WITHIN THE NEXT 24 HOURS OVER THE ENTIRE 
REGION WHILE A NEW FRONT APPROACHES THE NW GULF. 

CARIBBEAN SEA...
AS OF 0300 UTC...THE COLD FRONT OVER THE WEST CARIBBEAN STALLED 
AND BECAME A STATIONARY FRONT THAT EXTENDS FROM NORTHERN HAITI 
NEAR 19N73W TO 18N76W...OVER JAMAICA AND THEN SW TO 17N78W 
14N81W 12N82W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM 
EITHER SIDE OF THE FRONTAL BOUNDARY. WEST OF THE STATIONARY 
FRONT NORTHERLY WINDS IN THE RANGE OF 20-25 KT DOMINATE. 
EASTERLY TRADEWINDS IN THE RANGE OF 15-20 KT SPREAD OVER THE 
REMAINDER OF THE CARIBBEAN. IN THE UPPER LEVEL...A TROUGH OVER 
THE W ATLC DIPS S OVER THE NW CARIBBEAN N OF 20N SUPPORTING THE 
AFOREMENTIONED STATIONARY FRONT. NEAR ZONAL WESTERLY FLOW ALOFT 
DOMINATES THE REMAINDER OF THE CARIBBEAN SEA. WATER VAPOR 
SATELLITE IMAGERY CONTINUES TO SHOW VERY STRONG SUBSIDENCE AND 
DRY STABLE AIR ALOFT E OF 75 ACROSS THE REMAINDER OF THE BASIN. 
WITHIN THE NEXT 24 HOURS...THE STATIONARY FRONT SLOWLY WEAKENS. 
ISOLATED/SCATTERED SHOWERS ARE EXPECTED TO CONTINUE OVER THE NW 
CARIBBEAN WHILE WINDS OVER NW CARIBBEAN SHIFT FROM NORTHERLY 
FLOW TO EASTERLY FLOW. STRONGEST WINDS OF 25-30 KT ARE EXPECTED 
NEAR THE COAST OF COLOMBIA.  

ATLANTIC OCEAN...
THE PREVIOUSLY MENTIONED BROAD UPPER LEVEL TROUGH SUPPORTS A 
COLD FRONT THAT ENTERS THE DISCUSSION AREA AT 18/0000 UTC NEAR 
30N60W EXTENDING SW TO 25N64W 21N69W AND THEN N OF HAITI WHERE 
IT BECOMES STATIONARY. NO CONVECTIVE PRECIPITATION IS ASSOCIATED 
WITH THIS FRONT OVER THE W ATLC. HOWEVER ISOLATED SHOWERS ARE 
POSSIBLE WITHIN 200 NM WEST OF THE FRONT. E OF THE FRONT...A 
1026 MB HIGH PRES IS CENTERED NEAR 29N39W AND IS EXPECTED TO 
REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS. THIS SYSTEM 
EXTENDS A RIDGE OVER MOST OF THE E AND CENTRAL ATLC. ALOFT...AN 
UPPER RIDGE COVERS THE CENTRAL ATLC. A NARROW UPPER TROUGH IS 
OVER THE E ATLC WHICH IS SUPPORTING A DISSIPATING COLD FRONT 
CURRENTLY LOCATED BETWEEN THE MADEIRA AND THE CANARY ISLANDS. 

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR