000
AXNT20 KNHC 241040
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI APR 24 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1015 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 3N16W CROSSING THE EQUATOR 
NEAR 30W TO NE BRAZIL NEAR 2S45W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS WITHIN 240 NM EITHER SIDE OF THE AXIS E OF 
29W. ISOLATED MODERATE CONVECTION IS S OF 2N W OF 29W.

...DISCUSSION...

GULF OF MEXICO...
SFC HIGH PRESSURE IS LOCATED OVER THE FAR NE WATERS PROVIDING 
LIGHT AND VARIABLE FLOW IN ITS VICINITY. HOWEVER...E TO SE WINDS 
HAVE INCREASED TO 20-25 KT ACROSS MUCH OF THE REMAINDER OF THE 
REGION DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN THE HIGH AND 
BROAD SFC TROUGHING OVER MEXICO. THIS STRONG FLOW IS ELEVATING 
SEAS TO 8 FT OVER THE WRN WATERS BUT WILL LIKELY INCREASE A FEW 
MORE FT OVER THE NEXT DAY OR TWO AS WINDS REMAIN STRONG. DRY AIR 
AND ZONAL FLOW IN THE MID AND UPPER LEVELS IS SUPPORTING FAIR 
WEATHER ACROSS THE ENTIRE REGION. A SHORTWAVE TROUGH CURRENTLY 
OVER TEXAS IS EXPECTED TO SHIFT E INTO THE NW GULF LATER TODAY 
AND SAT...LIKELY BRINGING AN INCREASE IN MOISTURE TO THAT 
PORTION OF THE GULF.

CARIBBEAN SEA... 
SCATTERED SHOWERS AND ISOLATED TSTMS LIE OVER THE SW CARIBBEAN S 
OF 12N W OF 75W. LOW-LEVEL LIFT FROM CONVERGENCE ALONG THE ITCZ 
AND MOIST SWLY FLOW ALOFT APPEAR TO BE THE PRIMARY TRIGGERS. 
HOWEVER...LOCAL AND SMALL SCALE EFFECTS OVER COLOMBIA ARE 
PROVIDING ENHANCEMENT FOR THE DEEPER ACTIVITY NOTED INLAND. THE 
STRONG SWLY FLOW ALOFT IS SPREADING MOISTURE NE THOUGH IT 
APPEARS TO BE ONLY IN THE FORM OF MID-HIGH LEVEL CLOUDINESS. 
OTHERWISE...PATCHES OF LOW-MID LEVEL CLOUDS WITH EMBEDDED 
SHOWERS ARE SCATTERED ACROSS THE AREA...THICKEST OVER THE NE 
PORTION AND GULF OF HONDURAS. TRADE WINDS ARE IN THE 25-30 KT 
RANGE NEAR THE COAST OF COLOMBIA...AND MAINLY 20-25 KT 
ELSEWHERE. LITTLE CHANGE IN THIS WIND REGIME IS EXPECTED THROUGH 
THE WEEKEND AS STRONG HIGH PRESSURE REMAINS OVER THE W ATLC.

ATLANTIC OCEAN...
A LONGWAVE UPPER TROUGH CONTINUES TO PROVIDE SUPPORT FOR A 
FRONTAL BOUNDARY EXTENDING FROM 32N61W TO 27N67W THEN STATIONARY 
TO THE N COAST OF HAITI. MULTILAYER CLOUDINESS WITH EMBEDDED 
SCATTERED SHOWERS ARE WITHIN 300 NM E OF THE COLD FRONT AND 
WITHIN 180 NM EITHER SIDE OF THE STATIONARY PORTION. A 
REINFORCING FRONT IS APPROACHING THE AREA JUST NW OF BERMUDA. 
THIS BOUNDARY WILL LIKELY MERGE WITH THE LEADING ONE OVER THE 
NEXT 24 HOURS. SFC HIGH PRESSURE HAS BECOME ESTABLISHED BEHIND 
THE FRONT NEAR 30N70W. HIGH PRESSURE IS EXPECTED TO AMPLIFY OVER 
THE NEXT COUPLE OF DAYS IN THIS REGION SETTING UP STRONG ELY 
FLOW ON ITS SRN PERIPHERY. FARTHER E...A MID-UPPER LOW IS 
SITUATED NEAR 26N34W WITH TROUGHING EXTENDING WELL SW TO NEAR 
3N49W. INSTABILITY ASSOCIATED WITH UPPER CYCLONE IS PRODUCING 
SCATTERED SHOWERS AND ISOLATED TSTMS FROM 23N-31N BETWEEN 
30W-38W. AN UPPER JET ORIGINATES NEAR THE BASE OF THE UPPER 
TROUGH AND EXTENDS NE THROUGH THE CAPE VERDE ISLANDS TO NEAR THE 
CANARY ISLANDS. THIS FLOW IS ADVECTING TROPICAL MOISTURE WELL NE 
AND  ENHANCING CONVECTION ALONG THE ITCZ.

$$
CANGIALOSI