000
AXNT20 KNHC 161152
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 AM EDT FRI OCT 16 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.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 70W/71W S OF 16N MOVING W NEAR 15 KT. 
WAVE REMAINS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE AS 
INDICATED IN THE TOTAL PRECIPITABLE WATER IMAGERY AT A LOW 
AMPLITUDE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 16N 
TO INLAND OVER VENEZUELA/COLOMBIA BETWEEN 68W-73W INCLUDING THE 
ABC ISLANDS. 

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N11W 7N25W 8N44W 12N58W. A 
SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 11N40W TO 6N41W 
WITH A SECOND SURFACE TROUGH APPROACHING THE LESSER ANTILLES 
FROM 15N58W TO 10N60W. SCATTERED MODERATE/STRONG CONVECTION IS 
FROM 6N-11N BETWEEN 38W-46W. CLUSTERS OF SCATTERED MODERATE/ 
ISOLATED STRONG CONVECTION ARE FROM 4N-10N E OF 38W TO JUST 
INLAND OVER THE COAST OF W AFRICA AND WITHIN 75/90 NM OF LINE 
FROM 9N51W TO THE LESSER ANTILLES NEAR 14N61W. 

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE IS ANCHORED OVER CENTRAL MEXICO COVERING THE W 
GULF. A BROAD UPPER TROUGH IS OVER THE E HALF OF THE US COVERING 
THE N GULF TO 25N WITH THE ACCOMPANYING COLD FRONT MOVING INTO 
THE GULF. AT 0900 UTC...THE FRONT ENTERS THE GULF BETWEEN PANAMA 
CITY AND PENSACOLA FLORIDA W TO A 1008 MB LOW NEAR NEW ORLEANS 
LOUISIANA THEN SW BACK INTO THE GULF ALONG 28N94W TO INLAND OVER 
S TEXAS BETWEEN CORPUS CHRISTI AND BROWNSVILLE. SCATTERED TO 
HEAVY SHOWERS WITH SCATTERED TO NUMEROUS THUNDERSTORMS ARE 
WITHIN 120 NM SE OF THE FRONT BETWEEN 90W-94W AND STRONG N WINDS 
W OF THE FRONT IN THE GULF WATERS OFF THE TEXAS COAST. SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE AREA N 
OF 27N E OF 95W. THE S GULF IS DOMINATED BY DRY STABLE AIR 
GIVING THE S GULF CLEAR SKIES THIS MORNING. THIS FRONT IS 
EXPECTED TO CONTINUE TO PUSH S AND E EXITING THE GULF LATE 
SAT/EARLY SUN. 

CARIBBEAN SEA...
AN UPPER RIDGE IS ANCHORED ALONG THE COAST OF NICARAGUA NEAR 
13N84W WITH AN AXIS EXTENDING NE ALONG 17N72W TO OVER THE N 
LEEWARD/VIRGIN ISLANDS NEAR 18N63W. CLUSTERS OF SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS DOT THE AREA WITHIN 120/150 NM OF 
LINE FROM NICARAGUA NEAR 14N83W TO HAITI NEAR 20N73W. THIS UPPER 
FLOW IS DRAWING UPPER LEVEL TROPICAL MOISTURE OVER THE SE 
CARIBBEAN AND COUPLED WITH A SURFACE TROUGH JUST E OF THE LESSER 
ANTILLES ARE GIVING THE AREA S OF 15N E OF THE TROPICAL WAVE 
ACROSS THE WINDWARD ISLANDS SCATTERED SHOWERS AND POSSIBLE 
ISOLATED THUNDERSTORMS. THE NW CARIBBEAN REMAINS CLEAR THIS 
MORNING. 

ATLANTIC OCEAN...
BROAD UPPER TROUGH OVER THE E US AND N GULF OF MEXICO COVERS THE 
W ATLC N OF 26N W OF 62W WITH THE ASSOCIATED FRONTAL SYSTEM N OF 
THE REGION BUT IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS 
WITHIN 75 NM OF LINE FROM GRAND BAHAMA ISLAND NEAR 27N78W TO 
BEYOND 32N75W AND CLUSTERS OF SCATTERED SHOWERS DOTTING THE AREA 
N OF 26N FROM 65W-74W. A BROAD UPPER RIDGE REMAINS OVER THE W 
ATLC ANCHORED NEAR 25N58W EXTENDING AN AXIS NE TO BEYOND 32N38W. 
A BROAD UPPER LEVEL TROUGH IS N OF 30N FROM 35W-50W SUPPORTING A 
COLD FRONT THAT DRAPES INTO THE REGION NEAR 32N42W EXTENDING TO 
28N48W BECOMING STATIONARY TO 28N57W. ISOLATED SHOWERS ARE 
WITHIN 120 NM SE OF THE COLD FRONT. HIGH PRESSURE IS BRIDGING 
THE FRONT WITH A 1020 MB HIGH LOCATED S OF THE FRONT NEAR 
24N44W. BROAD COMPLEX UPPER LEVEL TROUGH COVERS THE E ATLC N OF 
16N E OF 35W SUPPORTING A WEAKENING 1012 MB LOW CENTERED NEAR 
27N30W WITH A SURFACE TROUGH EXTENDING ALONG 29N28W 25N27W TO 
20N35W. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS 
ARE FROM 25N-30N BETWEEN 23W-27W. 
 
$$
WALLACE