000
AXNT20 KNHC 222347
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT FRI MAR 22 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

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

THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU NEAR 
12N16W INTO THE EAST ATLC ALONG 3N21W EQ31W. THE ITCZ BEGINS AT 
EQ31W AND DIPS SOUTH OF THE EQUATOR TO BRAZIL ALONG 1S40W 3S46W. 
SCATTERED MODERATE CONVECTION IS FROM 3N-8N BETWEEN 17W-25W. 
 
...DISCUSSION...

THE GULF OF MEXICO...

AS OF 2100 UTC...A WARM FRONT IS ANALYZED ACROSS THE NORTHEAST 
GULF AS A WARM AND MOIST AIRMASS LIFTS NORTH. THE AXIS EXTENDS 
THROUGH LOUISIANA INTO THE GULF NEAR 30N89W CONTINUING INTO 
CENTRAL FLORIDA ALONG 28N85W 28N80W. SCATTERED SHOWERS...SOME 
HEAVY AND WITH THUNDERSTORMS...ARE WITHIN 70 NM SOUTH OF THE 
FRONTAL BOUNDARY WITH A FEW OTHER WIDELY ISOLATED HEAVY SHOWERS 
ACROSS THE SOUTHERN HALF OF FLORIDA. THE MAJORITY OF THE AREA 
HAS SOUTHEAST FLOW RANGING FROM 10-15 KT WITH MOSTLY CLEAR SKIES 
BESIDES NEAR THE WARM FRONT. ALOFT...MAINLY ZONAL WESTERLY FLOW 
DOMINATES AROUND VERY BROAD UPPER RIDGING. THE FRONT WILL 
CONTINUE TO LIFT NORTH UNTIL THE NEXT COLD FRONT SWEEPS ACROSS 
THE AREA BEGINNING LATE SATURDAY/EARLY SUNDAY. MOIST CONDITIONS 
ARE EXPECTED TO REMAIN ACROSS THE NE GULF FOR AT LEAST THE NEXT 
24 HOURS. 

THE CARIBBEAN SEA...
                                                 
MOSTLY FAIR WEATHER IS ACROSS THE CARIBBEAN DUE TO DRY AIR ALOFT 
AROUND A VERY BROAD UPPER LEVEL RIDGE COVERING THE BASIN. ONLY A 
FEW ISOLATED SHOWERS/THUNDERSTORMS ARE OVER HISPANIOLA AND 
PUERTO RICO NEAR A DISSIPATING COLD FRONT NORTH OF THE AREA. A 
LIGHT PRESSURE GRADIENT ACROSS THE AREA IS PRODUCING TRADEWINDS 
OF 10-15 KT THROUGHOUT WITH AN AREA OF 20 KT WINDS IN THE FAR NW 
CARIBBEAN. TRADEWIND FLOW IS EXPECTED TO INCREASE OVER THE NEXT 
24 HOURS AS THE PRESSURE GRADIENT INCREASES DUE TO HIGH PRESSURE 
BUILDING TO THE NORTH. 
 

THE ATLANTIC OCEAN...
 
SURFACE HIGH PRESSURE IS BEGINNING TO BUILD OVER THE WEST ATLC 
AROUND A 1017 MB HIGH NEAR 27N75W. THE RIDGE IS SUPPORTED BY A 
BROAD UPPER LEVEL RIDGE TO THE WEST OVER THE GULF OF MEXICO. THE 
SURFACE RIDGE WILL CONTINUE TO BUILD OVER THE NEXT DAY OR SO. A 
DEEP LAYERED TROUGH DOMINATES THE REMAINDER OF THE WEST ATLC AND 
INTO THE CENTRAL ATLC SUPPORTING A COLD FRONT THAT ENTERS THE 
AREA NEAR 32N53W AND CONTINUES ALONG 27N58W 23N64W DISSIPATING 
TO NORTH OF HISPANIOLA NEAR 20N70W. SCATTERED SHOWERS/ISOLATED 
THUNDERSTORMS ARE UP TO 200 NM EAST OF THE AXIS NORTH OF 25N 
WITH ISOLATED SHOWERS UP TO 90 NM EAST OF THE FRONT SOUTH OF 
25N. AN UPPER LEVEL RIDGE ALONG 38W SUPPORTS A SECOND SURFACE 
RIDGE ANCHORED BY A 1023 MB HIGH PROVIDING FAIR CONDITIONS 
ACROSS MUCH OF THE EASTERN ATLC. AN UPPER LEVEL TROUGH TO THE 
EAST ALONG 13W SUPPORTS A SMALL PORTION OF A DISSIPATING 
STATIONARY FRONT ALONG 31N10W TO 25N18W. NO SHOWER ACTIVITY IS 
NEAR THE FRONT. 

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

$$
WALTON