000
AXNT20 KNHC 192341
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST MON JAN 19 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N10W 2N20W 1N30W CROSSING THE 
EQUATOR NEAR 37W AND EXTENDING INTO NE BRAZIL NEAR 3S45W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN AROUND 
100 NM SOUTH OF AXIS BETWEEN 15W-31W. CLUSTERS OF MODERATE TO 
STRONG CONVECTION ARE NOTED ALONG THE NORTHERN COAST OF BRAZIL  
AND OVER FRENCH GUIANA AND SURINAME.   

...DISCUSSION...

GULF OF MEXICO...
A DEEP-LAYERED TROUGH OVER THE E CONUS AND THE NORTHERN GULF 
WATERS SUPPORTS A COUPLE OF COLD FRONTS CURRENTLY LOCATED OVER 
THE GULF REGION. STRONG WESTERLY FLOW ALOFT WITH CORE WINDS OF 
110-130 KT IS OBSERVED IN THE BASE OF THIS TROUGH AFFECTING MUCH 
OF THE GULF AND THE FLORIDA PENINSULA. AT 19/2100 UTC...ONE COLD 
FRONT EXTENDS FROM SW FLORIDA TO THE YUCATAN PENINSULA AND WILL 
MOVE SE OF THE AREA EARLY TONIGHT. A SECOND FAST MOVING COLD 
FRONT STRETCHES FROM THE WESTERN FLORIDA PANHANDLE TO 
BROWNSVILLE TEXAS. THIS FRONT IS FORECAST TO MOVE ACROSS SOUTH 
FLORIDA AND THE SE PORTION OF THE GULF TUE MORNING CLEARING THE 
AREA BY EARLY TUESDAY AFTERNOON. IN THE WAKE OF THE FRONT... 
BRISK NLY WINDS AND VERY STRONG COLD AIR ADVECTION ARE EXPECTED 
WITH THE RISK OF A SNOW FLAKE OR TWO AS SOUTH AS THE AREA OF 
TAMPA. THIS IS PROBABLY SO FAR THE COLDEST AIR OF THE SEASON. 
HIGH PRES WILL BUILD IN BEHIND THE SECOND FRONT.

CARIBBEAN SEA...
UNDER THE INFLUENCE OF A BROAD MID/UPPER-LEVEL RIDGE...DRY AIR 
AND STABLE ATMOSPHERIC CONDITIONS ARE AFFECTING MUCH OF THE 
CARIBBEAN SEA. AS A RESULT...GENERALLY FAIR WEATHER PREVAILS 
ACROSS THE MAJORITY OF THE AREA. HOWEVER...A SURFACE TROUGH 
EXTENDING FROM JAMAICA TO EASTERN PANAMA IS GENERATING A NARROW 
BAND OF MAINLY LOW/MID CLOUDS AND SCATTERED SHOWERS OVER THE 
CENTRAL CARIBBEAN. VIS SATELLITE IMAGERY REVEALS A SWIRL OF LOW 
CLOUDS ALONG THE TROUGH AXIS NEAR 12.5N. THIS TROUGH WILL 
CONTINUE TO DRIFT W AND DISSIPATE ALONG 80W TONIGHT. PATCHES OF 
LOW LEVEL MOISTURE ARE OVER HISPANIOLA AND THE WINDWARD PASSAGE 
AS WELL AS OVER PARTS OF HONDURAS AND GUATEMALA. THE NEXT COLD 
FRONT WILL MOVE THROUGH THE YUCATAN CHANNEL LATE TUE REACHING 
FROM HISPANIOLA TO NICARAGUA LATE WED. NW WINDS OF 20 KT WILL 
FOLLOW THE FRONT. MODERATE TRADE WINDS ARE BLOWING ACROSS THE 
BASIN.       

ATLANTIC OCEAN...
A JET-STREAM BRANCH WITH CORE WINDS OF 130-150 KT IS OVER 
CENTRAL FLORIDA AND THE W ATLC AHEAD OF A DEEP-LAYERED TROUGH 
LOCATED OVER THE EASTERN CONUS. THE STRONG WESTERLY WINDS ALOFT 
ARE REACHING CUBA AND THE NW CARIBBEAN N OF 20N. THE DEEP TROUGH 
IS ASSOCIATED WITH A SURFACE COLD FRONT THAT ENTERS THE FORECAST 
31N75W THEN CONTINUES SW ACROSS SOUTH FLORIDA AND THE GULF OF 
MEXICO. SW WINDS WITH GALE FORCE ARE BLOWING WITHIN 240 NM E OF 
THE FRONT AND N OF OF 27N. LOW LEVEL CONVERGENCE IS SUPPORTING 
SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 60 NM EITHER SIDE OF 
THIS COLD FRONT. ADDITIONALLY...A SECOND COLD FRONT IS FORECAST 
TO MOVE OFF THE SE UNITED STATES COAST LATE TONIGHT...REACHING A 
LINE FROM 31N70W TO THE FLORIDA STRAITS TUESDAY MORNING. FURTHER 
EAST...A STATIONARY FRONT ENTERS THE AREA NEAR 31N60W THEN 
CONTINUES SW TO NEAR 27N65W. AT THIS POINT...IT BECOMES A 
SURFACE TROUGH AND EXTENDS SW TO NEAR THE TURKS AND CAICOS 
ISLANDS. SCATTERED SHOWERS ARE ALONG THE FRONT/TROUGH AXIS. A 
SFC RIDGE ANCHORED BY A 1033 MB HIGH LOCATED NEAR 32N37W 
DOMINATES MOST OF THE EAST AND CENTRAL ATLC RESULTING IN MOSTLY 
FAIR WEATHER AND MODERATE TO STRONG TRADE WINDS. THIS HIGH PRES 
CENTER WILL DISSIPATE IN ABOUT 24 HOURS BUT A STRONGER ONE... 
ANALYZED 1038 MB TO THE NORTH...WILL REMAIN IN PLACE COVERING 
THE REGION. ACROSS THE TROPICAL ATLC...WESTERLY FLOW ALOFT IS 
PRESENT...WITH UPPER LEVEL DIVERGENCE ENHANCING THE CONVECTION 
ASSOCIATED WITH THE ITCZ.

$$
GR