[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 271747
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST THU JAN 27 2011

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
1715 UTC.

...THE ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 5N9W 2N20W 3N30W 2N40W CROSSING
THE EQUATOR AT 46W INTO NE BRAZIL. A CLUSTER OF MODERATE TO
STRONG CONVECTION IS WITHIN AROUND 90 NM OF 4.5N11W. SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 210 NM N OF
AXIS FROM 16W TO 33W. SIMILAR CONVECTION IS ALSO NOTED S OF 06N
TO THE EQUATOR BETWEEN 42W AND 51W.

...DISCUSSION...

GULF OF MEXICO...
A 1024 MB HIGH PRES CENTERED OVER SOUTH TEXAS NEAR 28N97W
EXTENDS A RIDGE EWD ACROSS THE ENTIRE GULF COVERING ALSO THE
FLORIDA PENINSULA AND SE MEXICO INCLUDING THE YUCATAN PENINSULA.
THIS SYSTEM WILL MEANDER OVER THE CENTRAL GULF SAT...THEN SHIFT
E OVER CENTRAL FLORIDA ON SUN ALLOWING SOUTHERLY RETURN FLOW TO
DOMINATE MOST OF THE GULF WATERS SUN AND MON. THE COLD FRONT
THAT WAS MOVING ACROSS THE SE PORTION OF THE GULF YESTERDAY HAS
EXITED THE REGION AND NOW REMAINS STATIONARY OVER THE FAR NW
CARIBBEAN. COLD AIR STRATOCUMULUS CLOUDS ARE SEEN COVERING THE
EASTERN GULF WATERS BEHIND THE FRONT DUE TO THE ADVECTION OF
COLD AIR OVER RELATIVELY WARM WATERS. PERSISTENT LOW CLOUDINESS
WITH EMBEDDED LIGHT SHOWERS ARE NOTED OVER THE WESTERN GULF
BANKING UP ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS...
AND A COASTAL TROUGH IS ANALYZED ON THE 1500 UTC MAP ALONG 96W
FROM 21N TO 27N. IN THE UPPER LEVELS...WLY FLOW DOMINATES THE
REGION TRANSPORTING ABUNDANT MID/UPPER LEVEL MOISTURE FROM THE
EPAC.

CARIBBEAN SEA...
AS PREVIOUSLY MENTIONED...A STATIONARY FRONT LIES OVER THE FAR
NW CARIBBEAN AND IS FORECAST TO DISSIPATE TONIGHT. A ROPE CLOUD
DELINEATES THE FRONT ON VISIBLE SATELLITE PICTURES. THE
REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A RIDGE
EXTENDING SE ACROSS THE CENTRAL ATLC FROM A 1027 MB HIGH
SITUATED NEAR 35N46W. AS A RESULT...FRESH TRADE WINDS CONTINUE
TO BLOW ACROSS THE EAST AND CENTRAL CARIBBEAN. PATCHES OF LOW
LEVEL MOISTURE REMAIN EMBEDDED WITHIN THIS FLOW AS SEEN ON
VISIBLE SATELLITE IMAGERY USHERING IN ISOLATED TO SCATTERED
PASSING SHOWERS. THESE SHALLOW SHOWERS ARE MORE CONCENTRATED
NEAR BUOY 42059 LOCATED IN THE EASTERN CARIBBEAN...AND SOUTH OF
JAMAICA. SOME OF THIS PATCHES OF MOISTURE ARE ALSO MOVING ACROSS
THE ABC ISLANDS. THE TRADE WINDS WILL RELAX SOME OVER THE
CENTRAL AND EASTERN CARIBBEAN THROUGH THE END OF THE WEEK AS
HIGH PRES SHIFTS ENE...THEN INCREASE AGAIN THIS WEEKEND INTO MON
OVER THE CENTRAL CARIBBEAN WATERS AS HIGH PRES BUILDS AGAIN N OF
AREA. COMPUTER MODELS SUGGEST WINDS OF 25-30 KT NEAR THE COAST
OF COLOMBIA BY EARLY SUN. IN THE UPPER LEVELS...A BROAD RIDGE
DOMINATES THE CARIBBEAN WITH MODERATE/STRONG SUBSIDENCE AND DRY
STABLE AIR ALOFT COVERING THE AREA E OF 80W.

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE FORECAST REGION NEAR 31N66W THEN EXTENDS
SW TO WESTERN CUBA AND BECOMES STATIONARY OVER THE FAR NW
CARIBBEAN. A BAND OF SHOWERS WITH ISOLATED TSTMS IS ASSOCIATED
WITH THE FRONT WHICH IS FORECAST TO STALL ACROSS CUBA AND THE
BAHAMAS THROUGH THIS EVENING WHILE THE NORTHEAST PORTIONS WILL
CONTINUE TO MOVE SE. MOISTURE ASSOCIATED WITH THE TAIL END OF
THE FRONT SHOULD REACH HISPANIOLA BY SAT. A SECOND COLD FRONT
STRETCHES FROM A 1010 MB LOW PRES NEAR 31N34W TO 22N41W. AT THIS
POINT...THE FRONT BECOMES TO DISSIPATE. SOME SHOWER ACTIVITY IS
NOTED WITHIN 180 NM AHEAD OF THE FRONT MAINLY N OF 24N. IN
BETWEEN FRONTS...THERE IS A RIDGE ANCHORED ON A 1028 MB HIGH
LOCATED NEAR 35N46W. THE GRADIENT BETWEEN THE HIGH AND THE LOW
PRESSURE MOVING SE INTO THE FORECAST AREA WILL PRODUCE A LARGE
AREA OF NLY WINDS IN THE 25 TO 35 KT RANGE N OF 25N BETWEEN 35W
AND 45W. A WEAK RIDGE COVERS THE EASTERN ATLC AND WEST AFRICA
WITH A 1019 MB HIGH NEAR 22N20W THAT IS FORECAST TO DISSIPATE
OVER THE NEXT 24 HOURS. ALOFT...A TROUGH/RIDGE/TROUGH PATTERN
DOMINATES THE REGION. A STRONG SHORT WAVE TROUGH IS QUICKLY
MOVING NE ALONG THE COAST OF NEW ENGLAND AND SUPPORTS THE
WESTERNMOST COLD FRONT. THE BROAD UPPER RIDGE THAT COVERS THE
CARIBBEAN SEA EXTENDS NWD OVER THE CENTRAL ATLC TO BEYOND
31N58W. ANOTHER UPPER LEVEL TROUGH IS OVER THE E ATLC ALONG 38W
N OF 20N. A JET STREAM BRANCH WITH CORE WINDS OF 70-90 KT ROUNDS
THE BASE OF THIS TROUGH AND EXTENDS NE THEN E INTO NORTHERN
AFRICA.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
GR






This weather bulletin was brought to you by:
www.nashvilleweather.net