000
AXNT20 KNHC 251704
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN JAN 25 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 
1645 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N8W 3N18W 1N29W CROSSING THE 
EQUATOR NEAR 42W INTO SOUTH AMERICA NEAR 1S47W. CLUSTERS OF 
SCATTERED MODERATE/STRONG CONVECTION ARE FROM 1N TO ACROSS THE 
EQUATOR BETWEEN THE PRIME MERIDIAN AND 10W. CLUSTERS OF 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120 NM 
ALONG THE COAST OF SOUTH AMERICA BETWEEN 39W-50W. 
 
...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER TROUGH COVERS THE E US AND THE GULF N OF 24N FROM 
TEXAS ACROSS FLORIDA INTO THE W ATLC SUPPORTING A FRONT WHICH 
HAS BECOME NEAR STATIONARY EXTENDING ACROSS NE FLORIDA ALONG 
29N84W TO 25N96W THEN DIPS S TO INLAND OVER MEXICO NEAR TAMPICO 
WITH THE WESTERN PORTION BEGINNING TO DRIFT NORTHWARD. ISOLATED 
SHOWERS ARE WITHIN 60 NM ALONG THE FRONT WITH MAINLY OVERCAST 
LOW LEVEL STRATUS COVERING THE REMAINDER OF THE GULF NW OF THE 
FRONT. A WEAK SURFACE RIDGE CONTROLS THE REMAINDER OF THE GULF 
ANCHORED ON A 1022 MB HIGH CENTERED OVER THE FLORIDA PENINSULA 
NEAR LAKE OKEECHOBEE. STRONG SUBSIDENCE AND DRY AIR ALOFT IS 
OBSERVED ACROSS THE ENTIRE AREA. 

CARIBBEAN SEA...
UNIFORM WESTERLY UPPER FLOW DOMINATES THE ENTIRE CARIBBEAN WITH 
STRONG SUBSIDENCE AND DRY STABLE UPPER AIR. THE REMNANTS OF A 
SURFACE TROUGH REMAINS ACROSS THE N/CENTRAL CARIBBEAN BUT HAS 
LOST THE UPPER LEVEL SUPPORT AND IS DRIFTING WESTWARD. IT NOW 
EXTENDS FROM 21N70W ACROSS HAITI TO 15N75W WITH ISOLATED LOW 
LEVEL SHOWERS WITHIN 120 NM NW OF THE TROUGH. AN UPPER LOW IN 
THE W TROPICAL ATLC AND EXTENDS TO JUST OVER THE LESSER 
ANTILLES. HIGH PRESSURE N OF THE AREA IS MAINTAINING MODERATE E 
TO NE TRADE WINDS ACROSS MUCH OF THE CARIBBEAN WITH PATCHES OF 
LOW LEVEL CLOUDS AND POSSIBLE ISOLATED SHOWERS ALONG THE 
MOUNTAINS OF CENTRAL AMERICA AND THE SW CARIBBEAN WATERS S OF 
12N W OF 81W.

ATLANTIC OCEAN...
THE UPPER TROUGH OVER THE GULF OF MEXICO COVERS THE W ATLC W OF 
63W SUPPORTING A FRONT ACROSS THE W ATLC JUST N OF THE REGION 
INTO THE GULF OF MEXICO NEAR JACKSONVILLE FLORIDA. ANY SHOWER 
ACTIVITY IS N OF THE REGION. THE REMNANTS OF AN UPPER LEVEL 
TROUGH OVER THE W/CENTRAL ATLC ARE ONLY SUPPORTING A SURFACE 
TROUGH THAT EXTENDS FROM 31N56W TO 26N60W. ISOLATED SHOWERS OVER 
THE TURKS AND CAICOS ALONG WITH THE SE BAHAMAS ARE MOVING AHEAD 
OF THE SURFACE TROUGH THAT IS OVER HAITI. A BROAD UPPER LOW IS 
IN THE W TROPICAL ATLC CENTERED NEAR 20N51W COVERING THE AREA 
FROM 10N-26N BETWEEN 46W-61W AND IS BEGINNING TO DRIFT 
NORTHWARD. A SECOND UPPER LOW IS CENTERED NE OF THE CAPE VERDE 
ISLANDS JUST OFF THE COAST OF AFRICA NEAR 20N18W EXTENDING AN 
UPPER TROUGH SW TO 12N27W. THE REMAINDER OF THE E ATLC IS 
DOMINATED BY AN UPPER LEVEL RIDGE WITH AXIS ALONG 36W. A SURFACE 
RIDGE OVERS THE W ATLC S OF 30N W OF 60W TO OVER THE GULF OF 
MEXICO WITH A 1021 MB HIGH NEAR 28N69W AND A 1022 MB HIGH OVER 
THE FLORIDA PENINSULA. A SECOND LARGER SURFACE RIDGE COVERS THE 
AREA E OF 55W AND THE SURFACE TROUGH TO INLAND OVER AFRICA 
ANCHORED BY A 1029 MB HIGH NEAR 32N33W. 

$$
WALLACE