[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 051139
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT JAN 05 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
1100 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 05N08W TO
02N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
02N14W TO THE EQUATOR NEAR 19W THEN ALONG THE EQUATOR BETWEEN
19W-38W. ISOLATED MODERATE CONVECTION IS FROM 01N-09N BETWEEN
18W-32W. THIS CONVECTION IS LIKELY ENHANCED BY AN UPPER LEVEL
TROUGH AXIS EXTENDING FROM 26N14W TO A BASE NEAR 06N33W.

...DISCUSSION...

GULF OF MEXICO...
SOUTH-SOUTHWESTERLY MIDDLE TO UPPER LEVEL FLOW IS EVIDENT ON
WATER VAPOR IMAGERY OVER MUCH OF THE GULF BASIN THIS MORNING
SOUTHEAST OF A MIDDLE TO UPPER LEVEL LOW CENTERED OVER OKLAHOMA.
UPPER LEVEL DIFFLUENCE IS MAXIMIZED OVER PORTIONS OF THE WESTERN
GULF AND FOCUSES ALONG A SURFACE TROUGH ANALYZED FROM 20N92W TO
26N97W WHERE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE
OCCURRING N OF 21N BETWEEN 92W-97W. ELSEWHERE...A LINGERING
FRONTAL BOUNDARY EXTENDS ACROSS THE SOUTHERN FLORIDA PENINSULA
AND INTO THE GULF AS A STATIONARY FRONT FROM 25N81W TO 23N87W.
WHILE THE APPROACHING UPPER LEVEL LOW AND ASSOCIATED DYNAMICS
HAVE 24 TO 36 HOURS BEFORE AFFECTING ANY SIGNIFICANT MOVEMENT OF
THE CURRENT FRONT...GLOBAL MODEL GUIDANCE INDICATES A WEAK
FRONTAL WAVE IS EXPECTED TO DEVELOP OVER THE NORTHWESTERN GULF
LATE SATURDAY AND THEN BEGIN TO MOVE EASTWARD AS A FRONTAL
BOUNDARY ON SUNDAY. ONCE THE BOUNDARY CLEARS THE REGION ON
MONDAY...E-SE WINDS AND RETURN FLOW WILL SET UP ACROSS THE
WESTERN GULF AS A LOW PRESSURE AREA DEVELOPS OVER NORTHERN
MEXICO AND SOUTHERN TEXAS INTO TUESDAY.

CARIBBEAN SEA...
THE CARIBBEAN IS INFLUENCED THIS MORNING BY A MIDDLE TO UPPER
LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 20N68W 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 30 KT WITH GALE
FORCE WIND CONDITIONS OFF THE COAST OF COLOMBIA CONTINUING
THROUGH LATE SUNDAY. SATELLITE IMAGERY INDICATES QUICK-MOVING
LOW-TOPPED ISOLATED SHOWERS ARE OCCURRING OVER A BROAD PORTION
OF THE BASIN FROM 12N-18N.

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 NEAR 20N68W. MIDDLE TO UPPER
LEVEL MOISTURE CONTINUES TO STREAM E-NE THEN EASTWARD FROM THE
NORTHERN FLORIDA PENINSULA N OF 28N TO BEYOND 50W. WEAK
MID-LEVEL ENERGY STRETCHES ALONG 36N BETWEEN 38W-56W AND
SUPPORTS A COLD FRONT ANALYZED FROM 32N48W TO 29N62W. ISOLATED
SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT.
ANOTHER MIDDLE TO UPPER LEVEL SHORTWAVE IS NOTED ON WATER VAPOR
IMAGERY PROGRESSING OFF THE MID-ATLC COAST NEAR 36N70W. WHILE
THE STRONGER DYNAMICS ARE WELL TO THE NORTH OF 32N...A
STATIONARY FRONT CONTINUES TO REMAIN DRAPED ACROSS THE REMAINDER
OF THE SW NORTH ATLC FROM 29N62W TO 30N69W TO THE FLORIDA
PENINSULA NEAR 26N80W. ISOLATED SHOWERS ARE OCCURRING N OF 28N
BETWEEN 62W-80W. FARTHER EAST...OVER THE CENTRAL AND EASTERN
ATLC...A SURFACE RIDGE DOMINATES ANCHORED BY A 1024 MB HIGH
CENTERED NEAR 25N60W. THE RIDGE AXIS REMAINS ROUGHLY ALONG 25N
BETWEEN 25W-75W. FINALLY...OVER THE FAR EASTERN ATLC...AN UPPER
LEVEL TROUGH AXIS EXTENDS FROM 26N14W TO A BASE NEAR 06N33W THAT
SUPPORTS A 480 NM WIDE BAND OF MULTILAYERED CLOUDINESS AND
POSSIBLE ISOLATED SHOWERS EAST OF THE TROUGH AXIS WHERE MIDDLE
TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED. THIS BAND EXTENDS FROM
NORTH OF THE ITCZ AXIS NEAR 04N30W TO 14N17W.

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

$$
HUFFMAN




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