[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122341
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE FEB 12 2013

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE SOUTHERN COAST OF SIERRA
LEONE NEAR 7N12W TO 5N20W. THE ITCZ BEGINS AT 5N20W AND
CONTINUES ALONG 1N30W EQ44W 2S47W. A CLUSTER OF MODERATE/STRONG
CONVECTION IS FROM 3N-4N BETWEEN 10W-12W...AND FROM 2N-4N
BETWEEN 23W-25W. SCATTERED MODERATE CONVECTION IS FROM 3N-6N
BETWEEN 37W-50W.

...DISCUSSION...

GULF OF MEXICO...
WHILE UPPER LEVEL RIDGING CURRENTLY COVERS THE GULF OF MEXICO
FOR THE TIME BEING...AN UPPER LEVEL TROUGH IS APPROACHING AND
SUPPORTS A 1008 MB SURFACE LOW OVER LOUISIANA NEAR 31N93W...AS
OF 2100 UTC. A COLD FRONT EXTENDS FROM THE LOW CENTER TO 25N98W
CONTINUING INTO NORTHEAST MEXICO. A WARM FRONT DRAPES ACROSS THE
NE GULF COAST STATES FROM THE LOW CENTER EASTWARD TO NEAR
31N83W. POSSIBLE ISOLATED SHOWERS ARE ALONG THE COLD FRONT WITH
SCATTERED SHOWERS WITHIN 60 NM OF THE WARM FRONT...ESPECIALLY
OVER THE FLORIDA PANHANDLE. THE REMAINDER OF THE GULF OF MEXICO
IS UNDER WEAK SURFACE RIDGING EXTENDING FROM THE WEST ATLC. THE
SURFACE RIDGING COUPLED WITH DRY AIR ALOFT IS PROVIDING FAIR
CONDITIONS ACROSS MUCH OF THE SOUTHERN AND CENTRAL PORTIONS OF
THE BASIN. MAINLY SOUTHERLY FLOW OF 15-20 KT IS EAST OF THE
FRONT SHIFTING TO NW FLOW WEST OF THE FRONT. EXPECT THE FRONT TO
MOVE THROUGH THE BASIN OVER THE NEXT COUPLE OF DAYS WITH SHOWERS
AND THUNDERSTORMS POSSIBLE NEAR THE AXIS.

CARIBBEAN SEA...
DRY AIR ALOFT COVERS THE CARIBBEAN AROUND A BROAD UPPER RIDGE
COVERING THE WESTERN HALF OF THE BASIN CENTERED OVER
GUATEMALA...AND AROUND AN UPPER LEVEL TROUGH IN THE CENTRAL ATLC
EXTENDING TO THE FAR EASTERN CARIBBEAN. STRONG SUBSIDENCE IS
ALSO NOTED IN WATER VAPOR IMAGERY OVER THE EASTERN CARIBBEAN.
THE DRY AIR AND SUBSIDENCE ALOFT IS HELPING PROVIDE FAIR
CONDITIONS ACROSS THE BASIN WITH ONLY A FEW AREAS OF LOW LEVEL
MOISTURE AND POSSIBLE ISOLATED SHOWERS. THESE AREAS OF LOW
MOISTURE ARE MAINLY FROM 15N-17N EAST OF JAMAICA TO THE LEEWARD
ISLANDS. THIS MOISTURE IS ALL THAT REMAINS OF A SHEAR AXIS THAT
IS QUICKLY DISSIPATING WITH ONLY A SMALL PORTION EXTENDING FROM
THE LEEWARD ISLANDS TO 15N64W. MAINLY 15-20 KT TRADEWIND FLOW
DOMINATES WITH A SMALL AREA OF 25 KT WINDS NEAR THE COAST OF
COLOMBIA. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
UPPER LEVEL RIDGING COVERS THE SW NORTH ATLC EXTENDING FROM THE
CARIBBEAN SUPPORTING SURFACE RIDGING AROUND A 1024 MB HIGH
CENTERED NEAR 31N54W. AN UPPER LEVEL TROUGH TO THE EAST ALONG
42W SUPPORTS A COLD FRONT THAT ENTERS THE AREA NEAR 32N38W AND
CONTINUES TO 23N45W WHERE IT BECOMES A SHEAR AXIS TO THE NE
CARIBBEAN NEAR 16N62W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS
ARE WITHIN 160 NM EAST OF THE COLD FRONT WITH POSSIBLE ISOLATED
SHOWERS NEAR THE SHEAR AXIS. THE FAR EASTERN ATLC IS DOMINATED
BY SURFACE RIDGING AROUND A 1031 MB HIGH EAST OF THE AZORES NEAR
38N19W. THE RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE COVERING
THE EASTERN ATLC ALONG 18W.

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

$$
WALTON





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