[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041144
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST FRI JAN 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N09W TO
04N11W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
04N11W TO THE EQUATOR NEAR 23W THEN ALONG THE EQUATOR BETWEEN
32W-40W. SCATTERED MODERATE CONVECTION IS FROM 01N-04N BETWEEN
12W-20W...AND FROM THE EQUATOR TO 06N BETWEEN 30W-37W.

...DISCUSSION...

GULF OF MEXICO...
SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW IS EVIDENT ON WATER
VAPOR IMAGERY OVER MUCH OF THE GULF BASIN THIS MORNING AS A
LINGERING FRONTAL BOUNDARY EXTENDS ACROSS THE FLORIDA PENINSULA
AND INTO THE GULF AS A STATIONARY FRONT FROM 27N82W TO 23N87W TO
22N93W THEN SOUTH-SOUTHEASTWARD TO THE MEXICO COAST NEAR 19N93W.
WHILE NO SIGNIFICANT UPPER LEVEL DYNAMICS ARE HAVING AN EFFECT
ON MOVING THE FRONT OUT OF THE REGION...GLOBAL MODEL GUIDANCE
INDICATES LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED ALONG THE
FRONT...AND A THETA-E GRADIENT STILL EXISTS TO THE NORTH OF THE
BOUNDARY. CONSIDERABLE CLOUDINESS AND POSSIBLE ISOLATED SHOWERS
ARE OCCURRING NORTH OF THE FRONT AS MOISTURE CONTINUES TO STREAM
NORTHEAST FROM THE SW GULF TO THE FLORIDA PANHANDLE AND INTO THE
SW NORTH ATLC. STRONG SURFACE RIDGING TO THE NORTHWEST OF THE
FRONT WITH AXIS ALONG THE MEXICO COAST IS PROVIDING FOR GALE
FORCE CONDITIONS S OF 22N WEST OF THE FRONT. THE GALE WARNING IS
FORECAST TO EXPIRE LATER TODAY...HOWEVER STRONG NORTHWEST WINDS
IN THE RANGE OF 20 TO 30 KT ARE EXPECTED TO PERSIST THROUGH
EARLY SATURDAY. OTHERWISE...E-NE WINDS IN THE RANGE OF 15 TO 25
KT ARE EXPECTED OVER PORTIONS OF THE NORTHERN GULF THROUGH THE
WEEKEND.

CARIBBEAN SEA...
THE CARIBBEAN IS INFLUENCED THIS MORNING BY AN UPPER LEVEL
ANTICYCLONIC CIRCULATION CENTERED NEAR 18N72W THAT IS PROVIDING
MOSTLY STABLE CONDITIONS ALOFT. WATER VAPOR IMAGERY INDICATES
VERY DRY AIR AND OVERALL SUBSIDENCE PREVAILS. AT THE SURFACE...
TRADES REMAIN IN THE RANGE OF 15 TO 25 KT WITH THE STRONGEST
WIND CONDITIONS EXPECTED BETWEEN 65W-82W THROUGH FRIDAY.
SATELLITE IMAGERY INDICATES QUICK-MOVING LOW-TOPPED ISOLATED
SHOWERS ARE OCCURRING OVER THE EASTERN CARIBBEAN E OF 72W AND
ACROSS THE WESTERN CARIBBEAN FROM 11N-19N BETWEEN 81W-86W...AND
IN THE VICINITY OF THE GULF OF HONDURAS W OF 87W INCLUDING
INLAND BELIZE.

ATLANTIC OCEAN...
MOSTLY ZONAL WESTERLY FLOW IS NOTED OVER MUCH OF THE SW NORTH
ATLC W OF 50W ON THE NORTHERN PERIPHERY OF AN UPPER LEVEL
ANTICYCLONIC CIRCULATION CENTERED IN THE NORTH-CENTRAL CARIBBEAN
SEA NEAR 18N72W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO
STREAM NE THEN EASTWARD FROM THE NORTHERN FLORIDA PENINSULA N OF
30N TO BEYOND 50W. AT THE SURFACE...A WEAK 1014 MB LOW IS
CENTERED NEAR 34N62W AND SUPPORTS A FRONTAL BOUNDARY W-SW TO THE
CENTRAL FLORIDA PENINSULA NEAR 27N80W. ISOLATED SHOWERS ARE
OCCURRING WITHIN 120 NM SE OF THE FRONT AND WITHIN 180 NM
NORTHWEST OF THE FRONT. THE REMAINDER OF THE SW NORTH ATLC IS
UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1023 MB
HIGH CENTERED NEAR 26N55W THAT ALSO EXTENDS INFLUENCE EASTWARD
ACROSS MUCH OF THE CENTRAL ATLC. A WEAKENING COLD FRONT DIPS
INTO THE DISCUSSION AREA ALONG 32N37W TO 29N52W AND CONTINUES TO
LACK ANY SIGNIFICANT MIDDLE TO UPPER LEVEL DYNAMIC ENERGY.
ISOLATED SHOWERS ARE WITHIN 210 NM EITHER SIDE OF THE FRONT.
FINALLY...OVER THE FAR EASTERN ATLC...AN UPPER LEVEL TROUGH AXIS
EXTENDS FROM 32N19W TO A BASE NEAR 08N36W THAT SUPPORTS A 480 NM
WIDE BAND OF MULTILAYERED CLOUDINESS AND POSSIBLE WIDELY
SCATTERED SHOWERS EAST OF THE TROUGH AXIS WHERE MIDDLE TO UPPER
LEVEL DIFFLUENCE IS MAXIMIZED. THIS BAND EXTENDS FROM NORTH OF
THE ITCZ AXIS NEAR 06N30W TO 19N16W.

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

$$
HUFFMAN




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