AXNT20 KNHC 160523
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE OCT 16 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 
0445 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 34W/35W S OF 20N MOVING W NEAR 15 KT. 
WELL DEFINED LOW/MID LEVEL INVERTED V-SHAPE CURVATURE IS 
OBSERVED BUT IS DISTORTED SOMEWHAT BY UPPER LEVEL WINDS. BROAD 
AREA OF CONVECTION IS ENHANCED BY UPPER LEVEL FEATURE. SEE.ITCZ 
BELOW. 

TROPICAL WAVE IS ALONG 54W S OF 14N MOVING W NEAR 10-15 KT. VERY 
LOW AMPLITUDE LOW/MID LEVEL INVERTED-V CURVATURE IS OBSERVED 
WITH NO ASSOCIATED SHOWERS/CONVECTION. 

TROPICAL WAVE IS ALONG 83W S OF 20N WITH A 1005 MB LOW ALONG THE 
WAVE NEAR 13N MOVING W NEAR 10 KT. WELL DEFINED LOW LEVEL 
INVERTED-V CURVATURE. WAVE IS MOVING INLAND OVER CENTRAL AMERICA 
AND LOSING DEFINITION. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 
ARE FROM 10N-18N BETWEEN 80W-88W. 

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 10N12W 7N20W 9N35W 10N55W 9N63W. 
NUMEROUS CLUSTERS OF SCATTERED MODERATE TO SCATTERED STRONG 
CONVECTION COVER THE AREA FROM 3N-20N BETWEEN 25W-34W AND FROM 
3N-13N BETWEEN 34W-45W. 

DISCUSSION...
GULF OF MEXICO...
A STRONG DEEP LAYERED LOW OVER THE CENTRAL US WITH A SUBTROPICAL 
JET OVER TEXAS WITH THE ASSOCIATED COLD FRONT WELL INLAND OVER 
CENTRAL TEXAS. A PRE-FRONTAL SURFACE TROUGH IS ALONG THE TEXAS 
COAST WITH SCATTERED SHOWERS WITHIN 60 NM ALONG THE COAST N OF 
CORPUS CHRISTI. UPPER RIDGE COVERS THE CENTRAL GULF EXTENDING 
FROM AN UPPER HIGH NEAR 22N94W ACROSS THE N GULF COAST NEAR 
PENSACOLA FLORIDA TO OVER THE CAROLINAS. UPPER DIFFLUENCE ON THE 
E SIDE OF THE UPPER RIDGE IS GENERATING SCATTERED 
SHOWERS/THUNDERSTORMS WITHIN 90/120 NM OF LINE FROM E CUBA NEAR 
23N83W ALONG 27N86W TO 28N90W. AN UPPER TROUGH IN THE 
W ATLC EXTENDS W TO OVER THE FLORIDA PENINSULA. AT THE 
SURFACE...A SURFACE TROUGH EXTENDS FROM THE BAY OF CAMPECHE NEAR 
18N94W THROUGH A 1006 MB LOW NEAR 22N94W THEN NE TO NEAR 29N87W  
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 120 NM OF 
LINE FROM THE BAY OF CAMPECHE NEAR 19N93W TO 28N90W. 

CARIBBEAN SEA...
THE UPPER RIDGE IN THE CENTRAL GULF OF MEXICO COVERS THE NW 
CARIBBEAN W OF 82W ENHANCING ACTIVITY ASSOCIATED WITH THE 
TROPICAL WAVE. LARGE UPPER LOW DOMINATES THE CARIBBEAN CENTERED 
NEAR 14N76W GENERATING SCATTERED SHOWERS AND WIDELY ISOLATED 
THUNDERSTORMS FROM OVER THE AREA BETWEEN 69W-80W. LARGE UPPER 
HIGH IN THE CENTRAL ATLC COVERS THE E CARIBBEAN GENERATING 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS E OF 69W TO JUST W OF 
THE LESSER ANTILLES. 

ATLANTIC OCEAN...
AN UPPER TROUGH IS OVER THE W ATLC WITH THE AXIS EXTENDING FROM 
30N73W TO OVER THE N BAHAMA ISLANDS NEAR 25N77W AND EXTENDS OVER 
THE FLORIDA PENINSULA. A DEEP LAYERED TROUGH WELL N OF THE 
REGION EXTENDS A COLD FRONT INTO THE CENTRAL ATLC NEAR 32N52W W 
ALONG 31N55W TO 31N65W WHERE A REMNANT FRONTAL BOUNDARY 
CONTINUES TO OVER THE CENTRAL BAHAMAS NEAR 25N75W GENERATING 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 125 NM OF A LINE 
FROM 28N68W TO BETWEEN CUBA AND THE BAHAMAS NEAR 22N78W. A LARGE 
UPPER HIGH IS IN THE CENTRAL ATLC NEAR 24N53W COVERING THE AREA 
N OF 15N FROM 30W-65W. A SHEAR AXIS EXTENDS ACROSS THE CANARY 
ISLANDS ACROSS THE E ATLC ALONG 18N34W AROUND THE BASE OF THE 
UPPER HIGH TO NEAR 13N57W. SURFACE HIGH PRESSURE COVERS THE ATLC 
N OF 20N E OF 60W WITH A 1022 MB HIGH JUST E OF THE AZORES AND A 
1019 MB HIGH JUST W OF THE CANARY ISLANDS NEAR 29N22W.  

$$
WALLACE