000
AXNT20 KNHC 030518
TWDAT 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL 
205 AM EDT WED APR 03 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 
0445 UTC.

...THE ITCZ/THE MONSOON TROUGH... 

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 8N13W AND CONTINUES ALONG 3N18W TO 1N26W WHERE THE 
ITCZ BEGINS THEN CROSSES THE EQUATOR NEAR 34W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 1N TO S 
OF THE EQUATOR E OF 3W ACROSS THE PRIME MERIDIAN...FROM 7N TO S 
OF THE EQUATOR BETWEEN 6W-14W INCLUDING PORTIONS OF SW AFRICA... 
AND FROM 4N TO THE EQUATOR BETWEEN 17W-28W. 

...DISCUSSION...

GULF OF MEXICO...                                                
A BROAD UPPER RIDGE COVERS THE CARIBBEAN AND GULF OF MEXICO WITH 
AN UPPER TROUGH MOVING ACROSS THE CENTRAL PLAIN STATES TO N 
MEXICO SUPPORTING A FRONTAL BOUNDARY WELL INLAND. SCATTERED 
SHOWERS/THUNDERSTORMS ARE INLAND OVER LOUISIANA AND TEXAS 
ASSOCIATED WITH THIS FRONT. A SURFACE TROUGH FORMED AT 03/0300 
UTC ALONG THE NW GULF COAST FROM NEAR 29N89W ALONG 29N94W THEN 
SW TO ACROSS S TEXAS S OF CORPUS CHRISTI NEAR 27N97W. SCATTERED 
SHOWERS/THUNDERSTORMS ARE WITHIN 90/120 NM S OF THE SURFACE 
TROUGH BETWEEN 90W-96W AND NW OF THE FRONT TO THE COAST OF 
LOUISIANA AND TEXAS N OF CORPUS CHRISTI. SE SURFACE FLOW OVER 
THE REMAINDER OF THE W GULF IS BANKING LOW CLOUDS WITH POSSIBLE 
ISOLATED SHOWERS W OF 93W. THE CONFLUENCE OF EASTERLY SURFACE 
FLOW AND WESTERLY FLOW ALOFT ACROSS THE CENTRAL GULF IS 
GENERATING SOME SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS MAINLY FROM 24N-28N BETWEEN 86W-91W. A DEEPENING 
LOW PRESSURE SYSTEM OVER TEXAS WILL MOVE INTO THE NW GULF WED 
NIGHT THEN CONTINUE E TO SE LOUISIANA THU MORNING AND NEAR 
PENSACOLA FLORIDA BY THU NIGHT. THE LOW WILL DRAG A COLD FRONT 
ACROSS THE GULF OF MEXICO THU AND FRI AND WILL MOVE SE OF THE 
GULF LATE FRI. 

CARIBBEAN SEA...                                                
A BROAD UPPER RIDGE DOMINATES MOST OF THE CARIBBEAN ANCHORED 
INLAND OVER SOUTH AMERICA. A WEAK BENIGN UPPER TROUGH IS MOVING 
ACROSS THE FAR E CARIBBEAN NEAR THE LESSER ANTILLES. A SURFACE 
TROUGH IN THE W ATLC EXTENDS TO OVER HISPANIOLA GENERATING 
SCATTERED SHOWERS N OF 17N BETWEEN 70W-74W. RELATIVE TIGHT 
PRESSURE GRADIENT EXISTS BETWEEN THE LOWER PRESSURE OF SOUTH 
AMERICA AND THE SURFACE RIDGE OVER THE W ATLC PRODUCING FRESH TO 
STRONG EASTERLY TRADE WINDS ACROSS THE CENTRAL CARIBBEAN WITH 
MODERATE TRADE WINDS ELSEWHERE. WATER VAPOR IMAGERY INDICATES 
STRONG SUBSIDENCE ACROSS MOST OF THE BASIN TONIGHT GIVING THE 
CARIBBEAN FAIR CONDITIONS ACROSS THE REMAINDER OF THE AREA. 
TRADE WINDS WILL PREVAIL THROUGH SUN. AN EXCEPTION WILL BE IN 
THE GULF OF HONDURAS WHERE FRESH TO STRONG WINDS WILL OCCUR EACH 
NIGHT THROUGH THU NIGHT. A COLD FRONT ASSOCIATED WITH THE 
DEVELOPING LOW PRESSURE SYSTEM IN THE GULF OF MEXICO IS EXPECTED 
TO REACH THE YUCATAN CHANNEL FRI DISSIPATING OVER THE NW 
CARIBBEAN SAT.

ATLANTIC OCEAN...                                               
THE UPPER TROUGH EXTENDS OVER THE W ATLC N OF 25N FROM 58W-80W 
SUPPORTING A COLD FRONT THAT ENTERS THE REGION AT 03/0300 UTC 
NEAR BERMUDA ALONG 29N68W TO 28N71W WHERE IT DISSIPATES TO 
27N78W. ISOLATED SHOWERS ARE WITHIN 30 NM E OF THE FRONT E OF 
68W. A SURFACE TROUGH IS S OF THE FRONT EXTENDING FROM 26N66W TO 
OVER HISPANIOLA NEAR 19N72W. A SHARP UPPER RIDGE IS TO THE E 
EXTENDING FROM 24N56W TO BEYOND 32N52W PROVIDING DIFFLUNCE ALOFT 
TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 
75/90 NM OF LINE FROM 23N64W TO BEYOND 32N56W. AN UPPER TROUGH 
IS OVER THE E ATLC N OF 25N E OF 35W SUPPORTING A COLD FRONT 
THAT ENTERS THE REGION NEAR 32N12W THROUGH THE CANARY ISLANDS TO 
25N19W. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC BETWEEN 
THE ABOVE FRONTS AND ANCHORED BY A 1030 MB HIGH NEAR 31N44W. THE 
W ATLC FRONT AND SURFACE TROUGH WILL MERGE THEN WILL DISSIPATE 
OVER THE N OF THE LESSER ANTILLES WED NIGHT. RETURN FLOW WILL 
INCREASE ACROSS THE W ATLC N OF 28N THU AHEAD OF THE NEXT COLD 
FRONT THAT WILL REACH FROM 32N75W TO S FLORIDA FRI AFTERNOON 
FROM 32N67W TO THE SE BAHAMAS SAT MORNING THEN FROM 32N62W TO 
THE WINDWARD PASSAGE SUN MORNING WHERE IT WILL STALL AND  
DISSIPATE.

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

$$
PAW