000
AXNT20 KNHC 141746
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAR 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N7W 3N10W CROSSING THE EQUATOR 
NEAR 26W EXTENDING TO 1S30W AND INTO NE BRAZIL NEAR 5S38W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 1N-6N 
BETWEEN 6W-15W.

...DISCUSSION...

GULF OF MEXICO...
DIFFLUENT WESTERLY FLOW ALOFT IS PRESENT ACROSS THE GULF REGION 
WITH DEEP LAYER ATMOSPHERIC LIFT THAT IS SUPPORTING A SURFACE 
STATIONARY FRONT THAT EXTENDS FROM S LOUISIANA NEAR 29N91W TO 
25N95W INTO A 1011 MB SURFACE LOW NEAR TUXPAN MEXICO. LOW LEVEL 
CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING 
SCATTERED SHOWERS AND TSTMS WITHIN 90 NM ON EITHER SIDE OF THE 
FRONT. SCATTERED SHOWERS ARE ALSO NW OF THE FRONT ACROSS THE 
TEXAS AND LOUISIANA GULF COAST. NLY SURFACE WINDS OF 20 TO 25 KT 
BEHIND THE FRONT WERE OBSERVED ON AN EARLY MORNING QSCAT PASS 
ACROSS THE FAR WRN GULF WATERS S OF 26N. TO THE SE OF THE 
FRONT...MODERATE SUBSIDENCE IS RESULTING IN GENERALLY FAIR 
WEATHER CONDITIONS ACROSS MUCH OF THE S/CENTRAL AND ERN GULF... 
INCLUDING THE FLORIDA PENINSULA.

CARIBBEAN SEA...
A STRONG SURFACE HIGH PRESSURE OVER THE W ATLC WILL MAINTAIN 
MODERATE TO STRONG TRADES OVER MUCH OF THE CARIBBEAN SEA THROUGH 
LATE MONDAY. GENERALLY FAIR WEATHER CONDITIONS ARE OBSERVED 
ACROSS MUCH OF THE CARIBBEAN REGION...WHERE DEEP LAYER DRY AIR 
IS PRESENT. HOWEVER...THE TRADE WINDS ARE ADVECTING PATCHES OF 
LOW LEVEL MOISTURE WWD ACROSS THE CARIBBEAN...WITH ISOLATED 
SHOWERS EMBEDDED WITHIN THESE PATCHES OF LOW LEVEL MOISTURE.

ATLANTIC OCEAN...
SOUTHWESTERLY FLOW ALOFT IS PRESENT ACROSS THE SE CONUS AND FAR 
W ATLC WITH DEEP LAYER ATMOSPHERIC LIFT SUPPORTING A SURFACE 
STATIONARY FRONT EXTENDING FROM THE NE FLORIDA PENINSULA NEAR 
30N81W TO 32N77W AND CONTINUING NE OF THE DISCUSSION AREA. LOW 
LEVEL CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING 
SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THE FRONT. TO THE 
SE OF THIS FRONT...AN UPPER LEVEL RIDGE IS IN PLACE. DEEP LAYER 
DRY AIR AND ATMOSPHERIC STABILITY IN THE VICINITY OF THIS UPPER 
LEVEL RIDGE ARE RESULTING IN GENERALLY FAIR WEATHER CONDITIONS. 
FARTHER TO THE E...AN UPPER LEVEL TROUGH IS N OF 25N BETWEEN 
25W-40W...WITH AN UPPER LEVEL LOW NEAR 31N35W. THE UPPER LEVEL 
LOW AND UPPER LEVEL TROUGH ARE ASSOCIATED WITH A 1007 MB SURFACE 
LOW NEAR 30N36W AND A DISSIPATING SURFACE STATIONARY FRONT 
EXTENDING FROM 31N31W ALONG 26N30W 20N33W...WHERE IT CONTINUES 
AS A SURFACE TROUGH TO 16N40W. ATMOSPHERIC INSTABILITY...UPPER 
LEVEL DIFFLUENCE...AND LOW LEVEL CONVERGENCE IN THE VICINITY OF 
THE SURFACE LOW AND FRONT ARE SUPPORTING SCATTERED SHOWERS AND 
TSTMS N OF 25N BETWEEN 26W-33W. THIS ACTIVITY IS BEING SUPPORTED 
BY UPPER LEVEL DIVERGENCE IN THE NE QUADRANT OF A 100-110 KT 
UPPER LEVEL JET MAXIMUM LOCATED SE OF THE UPPER LOW. FARTHER TO 
THE E...SUBSIDENCE ASSOCIATED WITH A NARROW SURFACE RIDGE IS 
RESULTING IN FAIR WEATHER CONDITIONS ACROSS THE E ATLC AND 
COASTAL W AFRICA. ACROSS THE TROPICAL ATLC...AN UPPER LEVEL 
RIDGE IS S OF 18N E OF 50W WITH AN UPPER LEVEL HIGH NEAR 9N20W. 
UPPER LEVEL DIVERGENCE ASSOCIATED WITH THIS FEATURE IS ENHANCING 
THE CONVECTION ASSOCIATED WITH THE ITCZ.

$$
HUFFMAN