000
AXNT20 KNHC 140525
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON SEP 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 61W/62W S OF 13N MOVING W 15-20 KT. THIS 
IS VERY LOW AMPLITUDE WAVE AND IS NOW MOVING INLAND OVER SOUTH 
AMERICA. WAVE AXIS IS PRECEDING THE DEEP LAYERED MOISTURE 
MAXIMUM AS INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY. NO 
ASSOCIATED SHOWERS/CONVECTION. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 17N15W THROUGH A 1014 MB LOW 
NEAR 14N23W CONTINUING ALONG 8N31W 8N43W 12N57W 10N64W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF 
LINE FROM 17N23W ACROSS THE NORTHERN MOST CAPE VERDE ISLANDS TO 
15N26W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS OVER THE REMAINDER OF THE AREA FROM 13N-17N 
BETWEEN 22W-28W INCLUDING THE REMAINDER OF THE CAPE VERDE 
ISLANDS. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION ARE FROM 5N-10N BETWEEN 28W-40W. ISOLATED SHOWERS DOT 
THE REMAINDER OF THE AREA WITHIN 120 NM OF THE ITCZ W OF 40W. 

...DISCUSSION...

GULF OF MEXICO...
A QUASI-STATIONARY BOUNDARY REMAINS ACROSS THE N GULF FROM A 
1010 MB LOW OFF THE COAST OF NE FLORIDA ACROSS THE FLORIDA 
PENINSULA NEAR MELBOURNE TO CEDAR KEY THROUGH PENSACOLA FLORIDA 
THEN OVER NEW ORLEANS LOUISIANA TO A 1005 MB LOW NEAR HOUSTON 
TEXAS...A DEVELOPING COLD FRONT EXTENDS S FROM THE LOW ALONG 
27N94W TO 24N97W. A STRONG UPPER LOW IS INLAND OVER OKLAHOMA 
WITH THE UPPER TROUGH EXTENDING S TO 24N COVERING THE GULF W OF 
90W WHILE AN UPPER RIDGE COVERS THE REMAINDER OF THE GULF 
ANCHORED NEAR 23N85W EXTENDING ACROSS FLORIDA INTO THE W ATLC. 
THIS SCENARIO COUPLED WITH THE ABUNDANCE OF DEEP LAYER MOISTURE 
COVERING ALL BUT THE FAR NW GULF IS GENERATING CLUSTERS OF 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE E GULF E OF 
91W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND AND 
WITHIN 45 NM ALONG THE COAST OF MEXICO IN THE BAY OF CAMPECHE. 
THE REMAINDER OF THE W GULF IS REMARKABLY CLEAR TONIGHT. 

CARIBBEAN SEA...
THE UPPER RIDGE ANCHORED IN THE SE GULF OF MEXICO COVERS THE W 
CARIBBEAN N OF 15N W OF 70W WHILE AN UPPER LOW N OF VIRGIN 
ISLANDS COVERS THE NE CARIBBEAN FROM HISPANIOLA TO THE LEEWARD 
ISLANDS. MOSTLY WESTERLY UPPER FLOW COVERS THE S CARIBBEAN.  
DIFFLUENCE ALOFT OVER THE NW CARIBBEAN IS GENERATING CLUSTERS OF 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 90 NM 
ALONG THE COAST OF HAITI AND CUBA. OTHERWISE THE REMAINDER OF 
THE CARIBBEAN IS REMARKABLY CLEAR AGAIN TONIGHT. 

ATLANTIC OCEAN...
A COLD FRONT EXTENDS FROM THE CENTRAL ATLC THROUGH 32N69W TO A 
1010 MB LOW IS OFF THE COAST OF NE FLORIDA NEAR 29N78W WITH A 
QUASI-STATIONARY BOUNDARY EXTENDING W ACROSS FLORIDA NEAR 
MELBOURNE INTO THE GULF OF MEXICO. THE UPPER RIDGE ANCHORED IN 
THE SE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF 70W NARROWING 
ALONG 26N70W TO BEYOND 32N60W PROVIDING DIFFLUENCE ALOFT TO 
GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S 
OF THE FRONTAL BOUNDARY AND NW OF A LINE FROM CUBA NEAR 21N76W 
TO BEYOND 32N58W. AN UPPER LOW IS N OF THE VIRGIN ISLANDS NEAR 
20N64W COVERING THE NE CARIBBEAN. A SMALL BUT STRONG UPPER HIGH 
IS CENTERED NEAR 29N52W NARROWING THE UPPER TROUGH THAT COVERS 
THE CENTRAL ATLC N OF 15N BETWEEN 35W-45W WITH THE ASSOCIATED 
FRONTAL BOUNDARY ENTERING THE REGION NEAR 32N35W EXTENDING SW 
ALONG 30N40W THEN NW 32N46W. DIFFLUENCE ALOFT IS GENERATING 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 90 NM OF LINE 
FROM 26N56W TO BEYOND 32N51W. A BROAD UPPER RIDGE REMAINS OVER 
THE E ATLC FROM THE TROPICS TO BEYOND 32N ANCHORED NEAR 20N21W 
AND PROVIDING THE SLY SHEAR OVER A 1010 MB LOW...THE REMNANTS OF 
FRED...CENTERED NEAR 19N36W AND ENHANCING THE ACTIVITY OVER THE 
CAPE VERDE ISLANDS.   

$$
WALLACE